<RECORD 1>

Accession number:20151400700214
Title:Effect of heating style on gasification process of pilot scale bubble fluidized bed
Authors:Li, Xiaowei (1); Liu, Jiankun (1); Wang, Guilu (1); Li, Minghe (1); Zheng, Lei (1); Ye, Renwen (2); Zhang, Dalei (1)
Author affiliation:(1) Department of Liaoning Institute of Energy Resources, Yingkou, China; (2) Shenyang Aerospace University, Shenyang, China
Corresponding author:Zhang, Dalei
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:275-279
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to study the heat process characteristics of pilot scale bubbing fluidized bed, by using the self heating pilot scale bubbling fluidized bed reactor of 50 kg/h in capacity, with sawdust as raw material, the experimental study on air gasification were conducted. At present, the externally heating for the fluidized bed startup was widely used in bench scale experiment. It had the advantages of rapidly raising of temperature, accurate control, etc., but the equipment was complex and difficult for maintenance, and was higher energy cost, especially, the externally heating was quite different with that for practical utilization. It is not helpful for find out the reaction characteristics so that the guiding for practical utilization was weakened. For solving the problem, using the pilot scale fluidized bed reactor as experimental device which is self heated, continuously fed and operated, air gasification experiment study on 3 temperature raising modes were conducted. Three temperature raising modes, which were sawdust combustion heating, sawdust/charcoal mixture combustion heating and charcoal combustion heating, were adopted respectively. The influence of different temperature raising ways on gasification temperature, tar content, the minimum fluidization velocity and gas quality in the process of gasification has been studied. The results showed that the heating effect of charcoal combustion was more ideal, and its heat value of charcoal was up to 32 MJ/kg, thus the heat released was much larger than that of sawdust. It provided more heat for bed heating process. In the preheating process, the warming up process was faster in the first hour, along with the increase of bed height, the heat storage in the bed material was also increased, and the heating rate was steady. It took 2.5 h for the gasification reactor to reach the reaction temperature. Due to the complexity for adding bed material and charcoal in the reactor, the optimization on the feeding device and the relevant measures will be the next step of work. The gasification reaction temperature could be controlled above 900, the higher temperature and heating rate favor the reduction of tar content, tar content at the gas outlet was about 1.15 g/m³. Due to the charcoal combustion providing more heat to the bed materials and the raising of temperature in the reactor, which was better than the other two heating modes. Increasing the temperature T<inf>2</inf>and the heating rate would benefit the reduction of tar content in the producer gas, thus, the heating with charcoal combustion could reduce the tar content in the producer gas and relief the gas purification process, meanwhile, the heating mode of charcoal combustion provided more heat for the gasification reactor in the preheating process and enhance the gasification intensity, which benefited the gasification reaction. The heat value of the producer gas was up to 6.9 MJ/m³, the producer gas quality was better than those of the other two heating modes; the bed temperature was also different in different heating modes. In the thermal experiment, the bed temperature had obvious influence on the minimum fluidization velocity, and it was different even in the same heating mode. The results showed that the minimum fluidization velocity tended to be influenced externally. The minimum fluidization velocity was affected by bed material particle size and heating rate, the minimum fluidization velocity was increased along with the increasing of the bed material particle size. The heating rate was fast, the small minimum fluidization velocity was low, and vice versus. This experiment can be self heating pilot fluidized bed experimental platform heating mode provides a new method of simple equipment, fast operation, good economy. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:15
Main heading:Fluidized beds
Controlled terms:Air purification - Charcoal - Chemical reactors - Combustion - Fluid catalytic cracking - Fluidization - Fluidized bed combustion - Fluidized bed furnaces - Fluidized bed process - Gases  - Gasification - Heat storage - Heating - Heating rate - Particle size - Preheating - Supersaturation - Tar - Temperature - Velocity
Uncontrolled terms:Bench scale experiments - Bubbling fluidized bed reactor - Fluidized bed reactors - Gasification reaction - Gasification temperatures - Heating mode - Minimum fluidization velocity - Reaction characteristics
Classification code:411 Bituminous Materials - 513 Petroleum Refining - 513.1 Petroleum Refining, General - 521.1 Fuel Combustion - 524 Solid Fuels - 533.1 Ore Treatment - 641.1 Thermodynamics - 641.2 Heat Transfer - 642.1 Process Heating - 642.2 Industrial Furnaces and Components - 643 Space Heating, Ventilation and Air Conditioning - 643.1 Space Heating - 672 Naval Vessels - 801.4 Physical Chemistry - 802 Chemical Apparatus and Plants; Unit Operations; Unit Processes - 804 Chemical Products Generally - 931.1 Mechanics - 931.2 Physical Properties of Gases, Liquids and Solids
DOI:10.3969/j.issn.1002-6819.2015.05.038
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 2>

Accession number:20151400700210
Title:Improving enzyme activity by compound microbial agents in compost with mixed fruit tree branches and pig manure during composting
Authors:Shi, Longxiang (1); Gu, Jie (1); Pan, Hongjia (1); Zhang, Kaiyu (2); Yin, Yanan (1); Zhao, Ting (2); Wang, Xiaojuan (1); Gao, Hua (1)
Author affiliation:(1) College of Resources and Environment, Northwest A&amp;F University, Yangling, China; (2) College of Sciences, Northwest A&amp;F University, Yangling, China
Corresponding author:Gu, Jie
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:244-251
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The effects of compound microbial agents in compost with mixed fruit tree branches and pig manure during composting in a thermophilic aerobic state were examined. The research used the inoculants compound microbial agents and control compost. The changes of temperature, enzyme activity, and the microbial community functional diversity in compost materials during composting were determined. The results showed the temperature during the composting period was increased and the high temperature (above 55) maintaining period was three days longer. Besides, inoculation treatment and control treatment are all carried out to achieve compost maturity, what was more, when added to the compound microbial agents composting process, we can easily find that the number of the seed germination in inoculants treatment is obviously higher than it is in the control treatment (P&lt;0.05), so we can find that this process caused the decrease of the pH value and the C/N ratio. Of course, they promoted the compost maturity. The activities of the enzymes were improved by adding compound microbial agents. The tested enzymes Cellulose, laccase (Lac), Manganese peroxidase (MnP), and lignin peroxidase (LiP) activities were higher in the treatment with microorganism agent than those in the control treatment by 15.0%-19.8%, 1.0%-11.0%, 4.1%-26.8%, and 4.0%-22.2%, respectively. The research showed that the activity of Cellulose, Laccase (Lac), and the lignin peroxidase (LiP) rose at the beginning of the experiment and then dropped gradually under the inoculants agent processing, and reached the peak value in the seventh day. Their numerical values were 0.96 mg/(g&middot;d) and 72.6 U/g respectively. However, the Manganese peroxidase (MnP) and Lignin peroxidase (LiP) reached their peak in the second day. Their numerical peak values were 927.2 and 726.4 U/g respectively. In addition, the activity of Manganese peroxidase (MnP) which was dealt with the inoculation treatment and control treatment was rising a little at the last period, and it may be affected by the content of the nitrogen in the last period. The average well color development (AWCD) value of microbes in compost was improved significantly, and six kinds of carbon sources used by the microbes during the high temperature period and cooling period were also significantly changed by the inoculation compound microbial agents. The research showed that the use of the inoculation agent processing to sugar and polyamine is obviously higher than the control treatment in the high temperature period. They are improved by 50.0% and 77.0% respectively. However, the use of carboxylic acid, polymer, and the polyphenolic substance were obviously lower than the control treatment, and their utilization rates were reduced by 23.5%, 44.7%, and 39.3% respectively. In the cooling temperature period, the use of the inoculants agent processing to the other five carbon sources, except polyamine, were all higher than that in the control treatment (P&lt;0.05). Principal component analysis clearly revealed that adding compound microbial agents plays a main role in the high temperature period during the composting, and the metabolic characteristics of micro flora during these two treatments were changing along with the composting process and the differentiation in the six utilizations of carbon sources were mainly sugars and amino acids. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:35
Main heading:Enzyme activity
Controlled terms:Amino acids - Bacteria - Carbon - Cellulose - Composting - Enzymes - Forestry - Fruits - Lignin - Manganese  - Manures - Microorganisms - Orchards - Polysulfones - Principal component analysis - Seed
Uncontrolled terms:Average well color development - Cooling temperature - Fruit trees - Functional diversity - Manganese peroxidase - Metabolic characteristics - Microbial communities - Microorganism agents
Classification code:452 Municipal and Industrial Wastes; Waste Treatment and Disposal - 452.3 Industrial Wastes - 461 Bioengineering and Biology - 543.2 Manganese and Alloys - 804 Chemical Products Generally - 804.1 Organic Compounds - 815.1.1 Organic Polymers - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 922.2 Mathematical Statistics
DOI:10.3969/j.issn.1002-6819.2015.05.034
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 3>

Accession number:20151400700186
Title:Design and experiment of gear-shaped diesel offgas particulate filter based on resistance
Authors:Guo, Xiurong (1); Liang, Zhongyu (1); Du, Danfeng (2); Qi, Zhanfeng (1); Li, Mingbao (3); Liu, Yuexiong (1)
Author affiliation:(1) Mechanical and Electrical College, Northeast Forestry University, Harbin, China; (2) Transportation College, Northeast Forestry University, Harbin, China; (3) Civil Engineering College, Northeast Forestry University, Harbin, China
Corresponding author:Guo, Xiurong
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:65-70
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Micron wood fiber is a kind of porous biological materials that can be applied to filter PM emitted by diesel engine. In this paper in order to increase the filtration area and decrease filtration resistance, a wood fiber filter, of which the internal structure was hollow and external structure like gear was developed, the advantages of which were low price, less requirement for diesel quality and large adsorption capacity for PM. In these respects, the gear-shaped wood fiber filter was promising in developing countries where the sulphur content was high in diesel oil. This gear-shaped wood fiber filter can be installed in a detachable DPF case where the temperature inside can be controlled below 220 and after reaching the end of its estimated useful lifetime it can be replaced easily. First of all, the pressure loss and structural parameters model of the diesel particulate filter (DPF) based on resistance were built. Referring to the existing research and empirical formula, the filtration resistance of the gear-shaped filters can be expressed by theoretical formula about tooth height, nominal pressure angle and the filter thickness. By analyzing through software Matlab, the tooth height, filter thickness and nominal pressure angle can be obtained. Furthermore, the tooth thickness and the teeth number can be obtained by some mathematic formula about gear. Then the optimal size of the gear-shaped wood fiber filter was figured out by numerical calculation and analysis. Lastly, the resistance changes of the gear-shaped wood fiber filter with different structural parameters were analyzed by the engine bench. In the test, we developed 8 gear-shaped filters with different structure parameters according to the simulation results and set the speed and the load of the engine kept at 2 200 r/min and 50%. The test results showed that when the diameter and height of the DPF case was 140 and 150 mm respectively, the parameters of the filter, whose tooth thickness was 23.27 mm, tooth height 30 mm, nominal pressure angle 5&deg;, filter thickness 7 mm, teeth number 8 were optimal. This filter had the lowest filtration resistance and increase rate of back pressure, the longest lifetime and the best structure stability. Meanwhile, some other filters whose structural parameters were in the optimal range of parameters also had better filtration performance than those of the rest. According to the test results, it can be known that when the parameters remained in the optimal range, the filtration performances were better and their differences were very small. Furthermore, their filtration efficiency was over 90% and the lifetime was about 90 hours. However, when the parameters were out optimal range, the filtration performances of the gear-shaped wood fiber filter get worse apparently, which definitely proves the reliability and the optimum of the structure parameters of the gear-shaped filter researched in this paper. Above all, the gear-shaped wood fiber filter researched here are low price, less requirement for diesel quality, low filtration resistance, high filtration efficiency, large adsorption capacity and easy to recycle after used. It can filter PM emitted by diesel engine efficiently by combining with temperature control device, which has a reference for environmental protection and purifying diesel exhaust. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:14
Main heading:Wood
Controlled terms:Adsorption - Air filters - Biological materials - Developing countries - Diesel engines - Diesel fuels - Engines - Fibers - Filters (for fluids) - Gear teeth  - MATLAB - Pressure - Semiconductor junctions - Structural optimization - Wood products
Uncontrolled terms:Adsorption capacities - Diesel particulate filters - DPF - Experimental study - Filtration performance - Filtration resistance - Numerical calculation - Structural parameter
Classification code:461.2 Biological Materials and Tissue Engineering - 601.2 Machine Components - 612 Engines - 612.2 Diesel Engines - 714.2 Semiconductor Devices and Integrated Circuits - 802.1 Chemical Plants and Equipment - 802.3 Chemical Operations - 811.2 Wood and Wood Products - 812 Ceramics, Refractories and Glass - 817 Plastics and Other Polymers: Products and Applications - 901.4 Impact of Technology on Society - 921 Mathematics - 921.5 Optimization Techniques - 931.1 Mechanics
DOI:10.3969/j.issn.1002-6819.2015.05.010
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 4>

Accession number:20151400700201
Title:Segmentation method for touching pest images based on shape factor and separation points location
Authors:Li, Wenyong (1); Li, Ming (2); Qian, Jianping (2); Sun, Chuanheng (2); Du, Shangfeng (1); Chen, Meixiang (2)
Author affiliation:(1) College of Information and Electrical Engineering, China Agricultural University, Beijing, China; (2) National Engineering Research Center for Information Technology in Agriculture, Beijing, China
Corresponding author:Chen, Meixiang
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:175-180
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Image segmentation is the precondition of feature extraction and recognition. In order to improve segmentation accuracy of touching objects in pest identification and counting system, an image segmentation algorithm based on shape factor and separation point location was presented. In this method, a shape factor that was defined using area and perimeter of a region was used to be a parameter to justify whether the region was one touching region or not. In this paper, the threshold of shape factor was set to be 0.50. And then, if a region was a touching one, its contour was stripped layer by layer. In each contour, it was necessary to check whether a local segmentation point existed or not. There were two types of local segmentation points. The first type was a point that was found twice in one contour at the same time, whose traversal sequence number satisfied the determined threshold condition. The second type was one point that could be found in one contour with its four connected region points at the same time, and the difference between their traversal sequence numbers satisfied the same threshold condition. Once the local segmentation point was found, two separating points of this touching region were searched and located in its original contour. The search method was based on the shortest distance between the local segmentation and the background pixel points. At last, the segmentation lines were plotted between the local segmentation and the two separating points. In order to verify the validity of the proposed algorithm, three types of touching images, such as serial connection, loop connection and hybrid connection images were used. The results showed that the proposed method could locate the local segmentation points and separating points more accurately than the watershed method. In addition, the lab and field images were used to test reliability of the proposed method. In the lab experiment, 100 yellow peach moth (Conogethes punctiferalis (Guen&eacute;e)) were collected and divided into two independent groups with 50 individuals in each one. In the field experiment, two sticky trap images of the Oriental fruit moth (Grapholitha molesta (Busck)) were used. In this paper, three criteria such as SR (segmentation rate), SERR (segmentation error rate), and SEFR (segmentation efficiency rate) were used to evaluate the segmentation results between the proposed method and the watershed method. The results showed that, in the lab experiment, the mean SR of watershed method was more than the proposed method, but the average segmentation error rate of the proposed segmentation method was 7%, which was reduced by 6 percentage points than the watershed method. The average segmentation efficiency rate of the proposed segmentation method was 92.65%, which was more than watershed method by 5.7 percentage points. In the field experiment, the average segmentation error rate of the proposed segmentation method was 2.24%, which was reduced by 4.29 percentage points than the one of the watershed method. The average segmentation efficiency rate of the proposed segmentation method was 97.8%, which was more than the one of watershed method by 3.95 percentage points. The series of data showed that the proposed segmentation algorithm located points accurately and its invalid segmentation rate was low. The presented segmentation method for touching pest image could improve the segmentation performance and had a remarkable significance for the feature extraction and pest identification. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:19
Main heading:Image segmentation
Controlled terms:Algorithms - Efficiency - Extraction - Feature extraction - Fruits - Image processing - Surface discharges - Watersheds
Uncontrolled terms:Contour-stripped - Feature extraction and recognition - Image segmentation algorithm - Segmentation algorithms - Segmentation error rate - Segmentation performance - Shape factor - Touching pest
Classification code:444.1 Surface Water - 701.1 Electricity: Basic Concepts and Phenomena - 716 Telecommunication; Radar, Radio and Television - 723 Computer Software, Data Handling and Applications - 723.2 Data Processing and Image Processing - 741 Light, Optics and Optical Devices - 741.1 Light/Optics - 802.3 Chemical Operations - 821.4 Agricultural Products - 913.1 Production Engineering - 921 Mathematics
DOI:10.3969/j.issn.1002-6819.2015.05.025
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 5>

Accession number:20151400700220
Title:Drying characteristics of poria cocos with different drying methods based on Weibull distribution
Authors:Zhang, Weipeng (1); Gao, Zhenjiang (1); Xiao, Hongwei (1); Zheng, Zhian (1); Ju, Haoyu (1); Xie, Long (1)
Author affiliation:(1) College of Engineering, China Agricultural University, Beijing, China; (2) China Research Center for Agricultural Mechanization Development, China Agricultural University, Beijing, China
Corresponding author:Zheng, Zhian
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:317-324
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Poria cocos is a traditional Chinese herbal medicine. It generally takes almost 7 days to be dried by traditional natural drying, and it is sensitive to microbial spoilage during drying. Poria cocos blocks (15 mm&times;15 mm&times;15 mm) are easily broken at the traditional hot air drying, such as oven drying. There are many drying methods, but we don't know how to choose the method quickly. The knowledge of different drying mechanism is necessary for heat and moisture transportation, energy savings and quality of product. To study the drying characteristics of poria cocos, overcom the drawbacks of poria cocos blocks which is easily broken and surface cracking after drying, improve the quality of dried poria cocos and shorten its drying time, the nature drying, oven drying, air impingement drying, pulsed vacuum drying approaches were applied to poria cocos drying. The Weibull distribution model was applied to the drying process under different drying methods and the results were analyzed. Combined with the GB-4857.5 T-1992Droping test methodandPharmacopoeia of People's Republic of China, the broken rate and extractum of poria cocos at different drying conditions were tested. The moisture effective diffusivity velocity and the activation energy were also calculated based on the scale parameter and shape parameter, and compared with Fick's second law. A comprehensive evaluation was also carried out for kinds of artificial drying methods based on the utilization rate of energy consumption, scale parameter, broken rate, extractum. The main results are as following: 1)four drying methods drying process all occurred in the falling rate period without constant speed stage, but oven drying and pulsed vacuum drying had the up-stage at the starting; 2) Weibull function can fit the drying curve of different methods accurately. Scale parameter decreased with the increasing temperature and air velocities. The shape parameter was related to the drying method, the shape parameter of oven drying and vacuum drying was higher than 1, and the air impingement drying's shape parameter was lower than 1; 3) the moisture effective diffusivity velocity and the activation energy were calculated based on the Weibull function, it can overcome the defects that the Fick's second law only was applied to the falling rate drying; The moisture effective diffusivity of poria cocos was 3.90&times;10^-9-20.40&times;10^-9m²/s; the activation energy was 29.45-40.09 kJ/mol, but there were differences among different drying methods; 4) the broken rate of poria cocos blocks exhibited significant difference for different drying methods, the broken rate of nature drying and vacuum drying was lower than 5.00%; At the range of testing parameters, temperature and air velocities didn't have significantly impact on the broken rate, The average was 62.68%; The broken rate increased with the rising temperature at oven drying; and 5) the extractum of poria cocos dried by pulsed vacuum method was most than others, and it ranged from 4.54% to 4.75%. Comprehensive evaluation results showed that the best drying method is pulsed vacuum drying. The results provide a reference for the application of Weibull distribution on poria cocos drying and help people gain the best drying method. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Drying
Controlled terms:Activation energy - Air - Chemical activation - Diffusion - Energy conservation - Energy utilization - Fick's laws - Function evaluation - Medicine - Models  - Moisture - Ovens - Plants (botany) - Spoilage - Surface defects - Technology transfer - Temperature - Vacuum technology - Velocity - Weibull distribution
Uncontrolled terms:Comprehensive evaluation - Effective diffusivities - Evaluation - Increasing temperatures - People's Republic of China - Poria cocos - Traditional Chinese herbal medicine - Weibull functions
Classification code:421 Strength of Building Materials; Mechanical Properties - 461.6 Medicine and Pharmacology - 461.9 Biology - 525.2 Energy Conservation - 525.3 Energy Utilization - 633 Vacuum Technology - 641.1 Thermodynamics - 642.1 Process Heating - 801.4 Physical Chemistry - 804 Chemical Products Generally - 822.1 Food Products Plants and Equipment - 902.1 Engineering Graphics - 911.2 Industrial Economics - 921.6 Numerical Methods - 922.2 Mathematical Statistics - 931.1 Mechanics - 931.3 Atomic and Molecular Physics - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2015.05.044
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 6>

Accession number:20151400700178
Title:Simulation and test of film sealing device for tray packaged vegetables preservation based on crank-slider mechanism and roller chute mechanism
Authors:Gao, Guohua (1); Ma, Shuai (1)
Author affiliation:(1) College of Mechanical Engineering and Applied Electronics Technology, Beijing University of Technology, Beijing, China
Corresponding author:Gao, Guohua
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:9-16
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The vegetables packed by plastic trays and fresh-keeping film are getting more and more popular in our life. So the tray-type vegetables preservation machine has became one of hot research areas in the world. During the working process of film sealing for vegetables in the tray, film is cut from three directions and sealed based on self-adhesive property. The complex movements about packing in this type cause that the drive parts of film sealing device are more complicated. It not only makes the manufacturing hard, but also leads to the rising costs. All these disadvantages limit the application and popularization of tray-type vegetables preservation machine. Based on this cutting method, the innovation design of film sealing device was carried out by using the linkage mechanism of roller chute and crank-slider mechanism to simplify the drives and reduce manufacturing cost in this study. As a drive mechanism, crank-slider mechanism was designed by using MATLAB for the optimal transmission performance when it was working. According to the calculation, the key design parameters of crank-slider mechanism were determined as follows: the minimum transmission angle was 42&deg;; the length of crank was 140 mm; the length of connecting rod was 340 mm; the length of connecting rod was 340 mm; the eccentric distance was 109 mm. And the structure parameter of linkage mechanism for roller chute was also designed. Its dynamic characteristics were obtained using the simulation of three-dimensional kinematics of cylinder, transverse cutting bar and longitudinal cutting plate using SolidWorks Motion. When the average speed of cylinder was 90 mm/s, the cutting speed of transverse cutting bar and longitudinal cutting plate were 710 and 310 mm/s, respectively, and work efficiency was up to 50 time/ min. By analyzing the working method of design scheme, transverse cutting bar and swing rod were found to have the lowest intensity. Using the SolidWorks simulation, the most vulnerable part of transverse cutting bar and swing rod was discovered. So, a prototype was fabricated according to the parameters design and simulation result. Based on the prototype, a series of tests were designed and carried out. Fifty tests were conducted. In the test, the plastic trays and rapes were regarded as film sealing object by using PE cling film. By recording each cutting cycle time by stopwatch and calculating its average value, we obtained that the efficiency of the prototype meeting the requirements of any available tray-type vegetables preservation machine was 40 times/min. The simulated velocity of cutting was similar to the measured value. The success rate of cutting was 88% and could be greatly improved if connection between lifting device and film sealing device of tray-type vegetables preservation machine is improved. The maximal testing cutting speed of transverse cutting bar and longitudinal cutting plate were 690 and 290 mm/s, respectively. Therefore, it is obvious that the new design of film sealing device about tray-type vegetables preservation machine is feasible. The study provides useful insights for the related design and has an important significance. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:20
Main heading:Sealing (closing)
Controlled terms:Connecting rods - Cutting - Cylinders (shapes) - Design - Equipment - Films - Manufacture - MATLAB - Packaging machines - Plates (structural components)  - Rollers (machine components) - Slideways - Vegetables
Uncontrolled terms:Crank slider mechanisms - Crank sliders - Dynamic characteristics - Key design parameters - Optimal transmission - Prototype - Sealing devices - Three-dimensional kinematics
Classification code:408 Structural Design - 408.2 Structural Members and Shapes - 537.1 Heat Treatment Processes - 601 Mechanical Design - 601.2 Machine Components - 602 Mechanical Drives and Transmissions - 603.2 Machine Tool Accessories - 604.1 Metal Cutting - 694.1 Packaging, General - 694.3 Packaging Equipment - 821.4 Agricultural Products - 901 Engineering Profession - 921 Mathematics - 933 Solid State Physics
DOI:10.3969/j.issn.1002-6819.2015.05.002
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 7>

Accession number:20151400700203
Title:Multiple regression analysis of soybean NDVI affected by meteorological factors
Authors:Zhang, Zhitao (1); Lan, Yubin (2); Zheng, Yongjun (2); Chen, Liping (2); Song, Peng (2)
Author affiliation:(1) College of Water Resources and Architectural Engineering, Northwest A&amp;F University, Yangling, China; (2) Aerial Application Technology, USDA-ARS-SPARC-APMRU, College Station, TX, United States; (3) College of Engineering, China Agricultural University, Beijing, China; (4) Beijing Research Center of Intelligent Equipment for Agriculture, Beijing, China
Corresponding author:Lan, Yubin
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:188-193
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Normalized difference vegetation index (NDVI) can be used as an ideal indicator of how the crops grow, with which the crops in different growing stages, harmful insects and diseases, water and fertilizer, and the yields can be well predicted. However, the accuracy of NDVI does not remain unchanged due to the ever-changing environmental factors, apart from the impact from the crops growing factors in different stages. The article investigates, using GreenSeeker, the soybean NDVI of its three growing stages of seeding, flowering &amp; podding and maturing in successive hours as the testing unit, for a more accurate monitoring of NDVI affected by air temperature, humidity, solar radiation, and wind speed, etc. in different periods of a day. The results show that the soybean NDVI values, being dynamic in different periods of a day, become smaller from 08:00 or 09:00 am in the morning, reach the valley in 14: 00 pm in the afternoon, then give a gradual rise, the whole dynamic process is similar to a quasi-parabola. Moreover, the soybean NDVI values demonstrate different daily variation ranges in different soybean growing stages. From 08:00 am to 18:00 pm, the biggest daily variation ranges are respectively among 0.13-0.23, 0.08-0.17 and 0.09-0.19, the biggest relative daily variation ranges are respectively among 20%-26%, 9%-19% and 11%-24%. The correlation study of the soybean NDVI values and the environment meteorological factors show that the changes in soybean NDVI values in its three growing stages are upon great influence by the solar radiation, air temperature, humidity and the wind speed. In four meteorological factors, the solar radiation and air temperature have a negative correlation with the soybean NDVI values at three stages (R²=0.424, 0.503, 0.631 and 0.602, 0.743, 0.757), humidity shows a positive correlation with the soybean NDVI values (R²=0.281, 0.435 and 0.654), and the wind speed exerts different influences in different soybean growing stages, specifically, a negative correlation in seeding, flowering &amp; podding (R²=0.432, 0.218), and in maturing stage (R²=0.127). The regression models were set up to test the impact of four meteorological factors on soybean NDVI and analyze the quantitative relations among them, namely Partial Least Squares (PLS), Stepwise Regression and Ridge Regression. It was found that among four meteorological factors affecting soybean NDVI values, the major factors are the solar radiation and the air temperature, while the minor ones are the wind speed and humidity and their influence on soybean NDVI values can be neglected. In significance tests, predictive accuracy of the three regression models for soybean NDVI in all three growing stages are all statistically significant (P&lt;0.01). By contrast, Ridge Regression has a slightly higher coefficient than partial least squares (PLS) and Stepwise Regression, while the latter two models have almost the same correlation. In contrast of the predictive values and the real test results of the three regression models for soybean NDVI, the Ridge Regression ranks the highest on predictive accuracy, with the Root Mean Square Error (RMSE) of 0.034, 0.018 and 0.016 and R²of 0.820, 0.908 and 0.934 in three stages of seeding, flowering &amp; podding and maturating, followed by a less accurate predictive level of Stepwise Regression and the least accuracy of PLS. Regression model can have a better prediction of daily variation trend of soybean NDVI values and a better accuracy of NDVI monitoring. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:25
Main heading:Regression analysis
Controlled terms:Atmospheric temperature - Crops - Least squares approximations - Mean square error - Meteorology - Solar radiation - Sun - Vegetation - Wind
Uncontrolled terms:Multiple regression analysis - NDVI - Normalized difference vegetation index - Partial least square (PLS) - Quantitative relations - Ridge regression - Root mean square errors - Soybean
Classification code:443 Meteorology - 443.1 Atmospheric Properties - 657.1 Solar Energy and Phenomena - 657.2 Extraterrestrial Physics and Stellar Phenomena - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.4 Agricultural Products - 921.6 Numerical Methods - 922.2 Mathematical Statistics
DOI:10.3969/j.issn.1002-6819.2015.05.027
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 8>

Accession number:20151400700209
Title:Environmental risk assessment in high intensive farming area based on material flow analysis
Authors:Yin, Guanyi (1); Liu, Liming (1); Qi, Xiaoxing (1); Yuan, Chengcheng (1); Zhuo, Dong (1)
Author affiliation:(1) College of Resources and Environmental Sciences, China Agricultural University, Beijing, China
Corresponding author:Liu, Liming
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:235-243
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:This study applied the material flow analysis (MFA) method to investigate the changes of resource input-pollution output flows from 2001 to 2012 in a high-intensive farming area in Taojiang County, China. In order to get an integrated index of total environmental risk, we built a comprehensive environmental risk assessment model on the basis of MFA. Direct material input (DMI), domestic processed output(DPO), material input per capita(IMC), material output per capita(IMD), material productivity(MP), environmental efficiency (EE) and production stock(Stock) were taken into the material flow analysis. DMI was divided into three large classes (solid, gases and liquid input) and eight subclasses including fertilizer (M1), pesticide(M2), mulching film (M3), O<inf>2</inf>consumed by livestock respiration (M4), O<inf>2</inf>consumed by soil respiration(M5), O<inf>2</inf>consumed by crop respiration(M6), irrigation water(M7) and diesel (M8). DPO was divided into three large classes (solid, gases and liquid output), and nine subclasses including livestock manure(N1), mulching film residue(N2), pesticide leaching(N3), fertilizer leaching(N4), CO<inf>2</inf>discharged by soil respiration(N5), CO<inf>2</inf>discharged by livestock respiration(N6), CO<inf>2</inf>discharged by crop respiration(N7), CH<inf>4</inf>discharged by livestock(N8), straw burning contaminants(N9), and diesel burning contaminants (N10). In addition, Stock was divided into four classes: crop products (P1), animal products (P2), forest products (P3), and aquatic products (P4). The results showed that due to the effect of population, economic output, arable area and agricultural technology, the stock increased by 56.52%, while material input and output index changed synchronously, which indicated that the increase of material input had brought the augment of pollution emissions. DMI increased from 52.10 million tons in 2001 to 65.05 million tons in 2012. Irrigation water was the main part of DMI. Among the gases input, M5 was the main part, which occupied 40.96% of gases consumption, while M6 and M4 accounted for 30.32% and 28.72%, respectively; among the solid input, M1 was the main part accounting for 98.92% of solid input, pesticide(M2) and mulching film(M3) occupied 0.65% and 0.51% of solid input, respectively. DPO increased from 17.75 million tons in 2001 to 22.56 million tons in 2012. Material discharging into the air was the main part of DPO, which averaged 1.58 million tons per year, while solid output and material discharging into water averaged 0.44 and 0.059 million tons per year, respectively. Among the gases output, N7, N9 and N5 accounted for 51.74%, 41.62% and 29.67% of total gases output, respectively. Moreover, the amount of CO<inf>2</inf>discharging averaged 1.05 million tons per year (derived from N5, N6, N7, N9 and N10), which occupied 97.02% of the total gases output. Among the solid output, N1and N2 accounted for 99.98% and 0.02%, respectively. Among the material discharging into water, fertilizer and pesticide averaged 0.06 and 0.004 million tons per year, respectively. IMC increased from 73 to 85 t/cap, and IMD increased from 25 to 29 t/cap; MP reduced from 0.03 to 0.01 t/yuan, and EE decreased from 0.009 to 0.005 t/yuan, which implied the material consumption per cap and pollution output per cap was still increasing, and economy increase was highly relevant to the consume of resources and discharge of pollution, while environmental efficiency had been improved to a small degree. The environmental risk index increased from 0.04 to 1.00, indicating that the whole environmental risk turned worse over the past 12 years, though it has been controlled slowly after 2010. The assessment method based on MFA can comprehensively reflect the evolution and structural characteristics of environmental risk in high intensive farming area, and can preferably reveal the development extent and variation of environmental risk. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:26
Main heading:Risk assessment
Controlled terms:Agriculture - Carbon dioxide - Crops - Fertilizers - Gases - Irrigation - Leaching - Liquids - Materials - Pesticides  - Pollution - Risks - Rural areas - Water
Uncontrolled terms:Agricultural technologies - Environmental risk assessment - Environmental risk indices - Environmental risks - High intensive farming area - Material flow analysis - Structural characteristics - Taojiang County
Classification code:444 Water Resources - 454.2 Environmental Impact and Protection - 533.1 Ore Treatment - 803 Chemical Agents and Basic Industrial Chemicals - 804 Chemical Products Generally - 804.2 Inorganic Compounds - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 922.1 Probability Theory - 931.2 Physical Properties of Gases, Liquids and Solids - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2015.05.033
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 9>

Accession number:20151400700198
Title:Extraction of vegetation information from visible unmanned aerial vehicle images
Authors:Wang, Xiaoqin (1); Wang, Miaomiao (1); Wang, Shaoqiang (2); Wu, Yundong (3)
Author affiliation:(1) Key Laboratory of Spatial Data Mining &amp; Information Sharing of Ministry of Education, Spatial Information Research Center of Fujian Province, Fuzhou University, Fuzhou, China; (2) Institute of Geographical Sciences and Nature Resources Research, CAS, Beijing, China; (3) School of Sciences, Jimei University, Xiamen, China
Corresponding author:Wang, Xiaoqin
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:152-159
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Unmanned Aerial Vehicle (UAV) Remote Sensing has great advantages over traditional methods, such as lower cost, simpler operation, faster access speed and higher resolution. In this paper, after analyzing the spectral characteristics of vegetation and non-vegetation in UAV images, which only contains red, green, and blue bands, we found that the vegetation spectral had the feature of green band&gt;red band&gt;blue bands, which means vegetation had the biggest reflection in the green band and had the smallest reflection in the blue band. However, non-vegetation region had the reflection feature of red band&gt;green band&gt;blue band and blue band&gt;green band&gt;red band. The pixels value of the vegetation region was smaller than the non-vegetation region. For overall consideration of the above characteristics and the features of the healthy green vegetation's spectral profile, and in order to enhance the vegetation information and minimize the vegetation signal, we referenced the form of NDVI and put forward a new vegetation index--VDVI (visible-band difference vegetation index). Then we calculated the vegetation index of VDVI, EXG, NGRDI, NGBDI, and RGRI. After calculation of the vegetation index, we used the same AOI region of the prior analysis in a typical spectral characteristic and we made the line charts to analyze the feasibility of each index. After observation of the line charts, we found that NGRDI was not suitable to extract the vegetation from a UAV image because the index values were overlapping with each other, except for bare soil. On the contrary, the NGBDI and VDVI was suitable for the extraction of vegetation from the image, because there was little overlapping. And the vegetation's EXG index value was greater than twenty and the value of non-vegetation was lesser than twenty except for the area of a building. However, there was also some overlapping of a building and the field, which could cause some mistake in the extraction of the result. After that, we determined the threshold value of each index. The threshold is most important in the extraction of vegetation from an image, but the value is very difficult to determine. After observation of the histogram of the vegetation index, we decided to use the bimodal histogram and the histogram entropy threshold method to determine the threshold value of each vegetation index, and compared each extraction result of the two methods and chose the value which had the higher extraction accuracy and used it as the final value to extract the vegetation from the UAV image. After comparison of the VDVI extraction results with EXG, NGRDI, NGBDI, and RGRI, we found that whatever method was used to determine threshold value, the accuracy of VDVI extraction result was always most precise, and the EXG must use the histogram entropy threshold method to determine the threshold. It can also extract the most vegetation information. The NGRDI and RGRI have bad extraction results. In conclusion, in the VDVI overall consideration of the vegetation characteristic of reflection in the green band and the absorbent in the red and blue bands, and its value ranged from-1 to 1. And the extraction accuracy of VDVI is higher than the others, and its threshold is easier to determine which is near to zero. In order to verify that the VDVI was suitable for another UAV image, we chose another UAV image to calculate its VDVI and extracted vegetation from it. Then we generated 200 random points to evaluate the vegetation extraction accuracy from the UAV image. From an accuracy report, we found the total extraction precision was 91.5%, and the kappa coefficient was 0.8256. We concluded that the VDVI was broadly suitable to extract vegetation from N UAV image which only contains a visible band. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Vegetation
Controlled terms:Airships - Entropy - Extraction - Graphic methods - Image processing - Remote sensing - Unmanned aerial vehicles (UAV) - Unmanned vehicles - Vehicles
Uncontrolled terms:Bimodal histograms - Extraction accuracy - Histogram entropy - Spectral characteristics - Threshold methods - Vegetation extractions - Vegetation index - Visible band
Classification code:432 Highway Transportation - 472 Ocean Engineering - 641.1 Thermodynamics - 652 Aircraft and Avionics - 731.1 Control Systems - 741 Light, Optics and Optical Devices - 802.3 Chemical Operations - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 902.1 Engineering Graphics
DOI:10.3969/j.issn.1002-6819.2015.05.022
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 10>

Accession number:20151400700195
Title:Experiment and model simulation of 3,5,6-TCP transport in different farmland purple soils
Authors:Lei, Wenjuan (1); Tang, Xiangyu (1); Guan, Zhuo (1); Zhou, Xiangyang (3); Wang, Bingxi (4); Zhang, Wei (1)
Author affiliation:(1) Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, China; (2) University of Chinese Academy of Sciences, Beijing, China; (3) State Key Laboratory of Hydraulics and Mountain River Engineering, University of Sichuan, Chengdu, China; (4) The Second Research Institute of CAAC, Chengdu, China
Corresponding author:Tang, Xiangyu
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:132-138
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:3, 5, 6-trichloro-2-pyridinol (TCP), the main degradation product of pesticide chlorpyrifos and herbicide triclopyr, exhibits strong anti-degradation ability, high water solubility and high migration capability, which would easily lead to soil and water pollution. This situation would be worse in the purple soil distribution areas, most in the upstream regions of Yangtze River, due to soils with low organic matter content, large pores with high water conductivity and erosion. In this study, three typical farmland soil samples were collected based on major land use of purple soil from Chinese Academy of Agricultural Agro Ecological Experimental Station (Yanting), including a sloping field sample located at higher relative elevation, a paddy field sample at lower relative elevation and a vegetable field sample close to the residential areas, corresponding to the crop rotation of wheat-corn, rice-rape and radish-cabbage, respectively. Physical properties of these soil samples were measured, including particle-size fraction, organic matter content, bulk density, pH value and content of clay minerals (montmorillonite and kaolinite). Then, the batch equilibrium method was used to determine the liquid-solid partition coefficient of the TCP to reveal the absorbing characteristics of these purple soil samples to TCP; meanwhile, miscible displacement experiment was carried out under steady-state flow condition (12 mL/h) with Br^-as a conservative tracer (50 mg/L), from which dispersion coefficient for TCP transport could be estimated by inverse simulation. Finally, the appropriate models were selected to simulate the physical and chemical processes of TCP in purple soil columns. The results were as follows: 1) The absorbing characteristics of purple soil to TCP were well described by the linear form of Freundlich Model, and the adsorption coefficients of sloping field, paddy field and vegetable field were 1.94, 1.22 and 1.02 L/kg, respectively. The content of clay and its components (montmorillonite and kaolinite) were the main factors affecting the adsorption coefficients; 2) The equilibrium outflow concentration of TCP in the outflow was 77%, 84% and 92% (relative concentration to the TCP outflow) respectively and the equilibrium time was at 2.88 PV, 4 PV and 6.5 PV, suggesting high pollution risk to deep soil layer, surface water and groundwater. Especially in the slope field, TCP displayed more easily and faster to enter the groundwater through infiltration and rivers through the surface runoff and lateral flow at the slope. 3) The two sites non-equilibrium convection-diffusion model could well simulate the transportation of TCP through purple soil columns, with a determination coefficient larger than 0.90 and the mean square errors (MSE) ranging from 0.009 to 0.021. These hydrodynamic and absorbing parameters from the experiment or reverse simulation revealed the reasons why TCP transportation was different among the three farmland purple soils: in the transient-absorption-dominated uniform soil environment, the main factor affecting dispersion coefficient was the flow velocity, which was mainly controlled by soil porosity or bulk density under the condition of stead flow without pressure; and dispersion coefficient and first-order kinetic rate constant showed an increase trend from vegetable field to paddy field, and then sloping field, while fractal coefficient displayed a decrease trend. These results are important to disclose TCP transfer mechanism in purple soil, and can also provide valuble information for preventing pollution caused by the pesticide and herbicide, especially their degradation productions, to the soil and water environment in the upstream regions of Yangtze River. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Soil pollution
Controlled terms:Adsorption - Agriculture - Biogeochemistry - Biological materials - Clay minerals - Degradation - Dispersions - Effluent treatment - Farms - Flow velocity  - Groundwater - Groundwater pollution - Herbicides - Kaolinite - Land use - Mean square error - Organic compounds - Organic minerals - Particle size - Pesticides  - Pollution - Porosity - Rate constants - River pollution - Rivers - Runoff - Soil surveys - Soils - Surface waters - Vegetables  - Water pollution - Water resources - Weed control
Uncontrolled terms:3 ,5 ,6-Trichloro-2-pyridinol - 3,5,6-TCP - Chlorpyifos - Convection-diffusion models - Purple soils - Steady-state flow conditions - Surface water and groundwaters - Tillage types
Classification code:403 Urban and Regional Planning and Development - 444 Water Resources - 452.4 Industrial Wastes Treatment and Disposal - 453 Water Pollution - 454.2 Environmental Impact and Protection - 461.2 Biological Materials and Tissue Engineering - 481.2 Geochemistry - 482.2 Minerals - 483.1 Soils and Soil Mechanics - 631 Fluid Flow - 731.1 Control Systems - 802.2 Chemical Reactions - 802.3 Chemical Operations - 803 Chemical Agents and Basic Industrial Chemicals - 804.1 Organic Compounds - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.4 Agricultural Products - 931.2 Physical Properties of Gases, Liquids and Solids - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2015.05.019
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 11>

Accession number:20151400700216
Title:Characteristic of gas production of over-ground household thermostatic biogas digester heated by solar energy
Authors:Li, Jinping (1); Shan, Shaoxiong (1); Dong, Ti (1)
Author affiliation:(1) Western China Energy &amp; Environment Research Center, Lanzhou University of Technology, Lanzhou, China
Corresponding author:Li, Jinping
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:287-291
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to solve the problems of unstable gas production, the low biogas production rate, and the zero-gas production in winter existing in the traditional biogas digester with a brick-concrete structure, an over-ground household thermostatic biogas digester heated by solar energy was developed and constructed. The system consists of a glass evacuated tube collector with the collector area of 2.96 m², a 2 m&times;2 m&times;3.2 m insulating chamber, a 3 m³plastic biogas digester, a 3 m³reservoir bag, an automatic temperature controller, a heating coil, and some other small parts. The energy collected by the solar collector is stored in water and the hot water is circulated in the heating coil by the circulating pump. The pump is directly controlled by the automatic temperature controller. The automatic temperature controller can be set an initial value. If the fermentation temperature is below the set point, the automatic control system will work to let the circulating pump start, and then the hot water will transfer heat to the biogas digester through the heating coil to keep the fermentation temperature at the set point. And similarly, the circulating pump will be shut down, controlled by the automatic control system, if the fermentation temperature reaches or exceeds the set value. Experimental study on the gas production of the system in winter was carried out. The fermentation material consisted of 0.5 m³pig manure, 0.5 m³inoculum, and 1 m³water. During the experiment, the temperature data was recorded by the Agilent data acquisition instrument, the daily gas yield was measured by the gas meter, the gas content is measured by the portable gas analyzer, and the pH value was recorded by the portable pH meter, which was done at 17: 00 every day. In order to ensure the uniformity of heat transfer and material liquid in the digester, stirring work was done daily. By analyzing the data collected, we could conclude that the solar collector can ensure the digester's stable operation at a constant temperature of (26&plusmn;2), with the ambient temperature ranging from -19.8 to -10.0 during the 39 days fermentation period. The cumulative gas production was 42.520 m³. When the system was operated steadily and the gas production rate was relatively smooth and steady, the average daily gas production was 1.380 m³. The average content of CH<inf>4</inf>was 58.2%. And by also analyzing the temperature data of a typical day (The day after two cloudy days), we could conclude that the lowest solar hot water temperature was higher than the fermentation temperature needed, which could ensure the continuous heat supply from the solar water to the digester, despite bad weather. It showed that the system has a good ability for resisting disturbance from its surroundings. According to the biogas engineering and technical specification of China and the average daily gas production, the system can satisfy 4-5 farmers' domestic gas demand in the winter days of cold areas. Therefore, the over-ground household solar heating biogas digester was of great significance to meet farmers' domestic gas demand, recycle organic waste resources in rural areas, and improve the residential environment as well as the construction of a new countryside. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:15
Main heading:Heating
Controlled terms:Agricultural wastes - Agriculture - Automation - Biogas - Control systems - Controllers - Data acquisition - Fermentation - Gases - Heat transfer  - Houses - Process control - Pumps - Rural areas - Solar collectors - Solar energy - Solar heating - Temperature - Temperature control - Water
Uncontrolled terms:Biogas digesters - Biogas production - Biogas production rates - Cumulative gas productions - Evacuated tube collectors - Fermentation temperature - Technical specifications - Temperature controllers
Classification code:402.3 Residences - 444 Water Resources - 615.2 Solar Power - 618.2 Pumps - 641.1 Thermodynamics - 641.2 Heat Transfer - 643.1 Space Heating - 702.3 Solar Cells - 723.2 Data Processing and Image Processing - 731 Automatic Control Principles and Applications - 732.1 Control Equipment - 802.2 Chemical Reactions - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.5 Agricultural Wastes - 931.2 Physical Properties of Gases, Liquids and Solids
DOI:10.3969/j.issn.1002-6819.2015.05.040
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 12>

Accession number:20151400700185
Title:Numerical analysis of acoustic and resistance performance of muffler in refrigeration compressor's discharge pipe
Authors:Kong, Xiangqiang (1); Chen, Lijuan (1); Li, Ying (1)
Author affiliation:(1) College of Mechanical and Electronic Engineering, Shandong University of Science and Technology, Qingdao, China
Corresponding author:Kong, Xiangqiang
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:59-64
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The noise level has become an important index to evaluate the quality of air conditioners, and the refrigeration compressor is a major noise source of an air conditioners' outdoor unit. In order to reduce the noise of an air conditioner, by means of the theories that the noise is spread by fluid and the acoustics impedance mismatch occurs in the pipe with variable cross sections, a muffler was set in a refrigeration compressor's discharge pipe. The finite element model of a refrigerant in the muffler was established, based on which, the transmission loss could be numerically simulated by acoustics software Virtual Lab Acoustics, as well as the resistance performance by the computational fluid dynamics software Fluent. The effect of various structural parameters on the transmission loss and pressure loss of the muffler was investigated, including the length of the expansion chamber, and the position and the inner diameter of the orifice plate. The simulation results showed that the transmission loss curve of the muffler gradually moved to the higher frequency as the length of the expansion chamber decreases, which could also expand the effective acoustic attenuation frequency range, but it had little effect on the pressure loss of the muffler. To effectively reduce the noise of the compressor, the length of the expansion chamber should be appropriately selected. When the length of the expansion chamber was bigger than 140 mm, the noise of 2000-3000 Hz was effectively reduced, and the frequency of more than 2000 Hz was the main frequency region of the rotary compressor noise, so the length of expansion chamber was suggested to be bigger than 140 mm, but the length cannot be too big for decreasing the pressure loss of the muffler. For middle and high frequency noise, the position of orifice plate had a great influence on the acoustic attenuation performance of the muffler. As the orifice plate moved from the center of expansion chamber to its inlet surface, the acoustic attenuation performance for the frequency of 2000-2400 Hz gradually became better, while the pressure loss of the muffler decreased and the declination rate gradually increased, so the orifice plate should not only deviate from the center of the expansion chamber, but also get as close to the inlet of the muffler as possible within the permitted range. Moreover, the muffler could achieve better acoustic attenuation performance along with the decrease of the inner diameter of orifice plate, but the pressure loss of the muffler increased gradually with its increase rate tending to be bigger. As a result, in order to achieve an effective noise reduction and reduce the pressure loss of the muffler, the inner diameter of the orifice plate should not be too small. If the pressure loss of the muffler is required to less than 600 Pa, the inner diameter of the orifice plate should be bigger than 6 mm. In the design of the muffler, in addition to obtaining better acoustics attenuation performance, the pressure loss of the muffler needs to be considered, so that the performance of an air conditioner system cannot be greatly influenced. The research results would be able to provide a theoretical base for the noise reduction of air conditioners. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Acoustic noise
Controlled terms:Acoustic impedance - Acoustic properties - Acoustics - Air - Air conditioning - Compressors - Computation theory - Computational fluid dynamics - Computer simulation - Domestic appliances  - Electric attenuators - Expansion - Finite element method - Mufflers - Noise abatement - Noise pollution - Noise pollution control - Orifices - Plates (structural components) - Pollution control  - Pressure effects - Quality control - Refrigeration - Wave transmission
Uncontrolled terms:Acoustic attenuation performance - Air conditioner systems - Attenuation performance - Computational Fluid Dynamics software - Pressure loss - Refrigeration compressors - Transmission loss - Variable cross section
Classification code:408.2 Structural Members and Shapes - 454.2 Environmental Impact and Protection - 522 Gas Fuels - 612.1.1 Internal Combustion Engine Components - 618.1 Compressors - 619.1 Pipe, Piping and Pipelines - 643.3 Air Conditioning - 644.4 Cryogenics - 704.1 Electric Components - 711 Electromagnetic Waves - 715 Electronic Equipment, General Purpose and Industrial - 723.5 Computer Applications - 751 Acoustics, Noise. Sound - 804 Chemical Products Generally - 913.3 Quality Assurance and Control - 921 Mathematics - 921.6 Numerical Methods - 931.1 Mechanics - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2015.05.009
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 13>

Accession number:20151400700218
Title:Land leveling partitioning of farming area in arid plain based on spatial clustering
Authors:Hao, Xingyao (1); Pan, Yuchun (2); Tang, Xiumei (2); Qiu, He (2); Liu, Yu (2); Ren, Yanmin (2)
Author affiliation:(1) Beijing Forestry University, Beijing, China; (2) National Engineering Research Center for Information Technology in Agriculture, Beijing, China; (3) Key Laboratory of Agri-Informatics, Ministry of Agriculture, Beijing, China; (4) Beijing Engineering Research Center of Agricultural Internet of Things, Beijing, China
Corresponding author:Pan, Yuchun
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:301-307
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Land leveling accounts for the major part of project quantity and investment of land consolidation. Rational planning and implementation of land leveling project have important practical significance to reducing the project investment. Partitioning of leveling area is beneficial to reducing the project quantity and facilitating project organization. However, the existing empirical partitioning methods are mainly based on farmland irrigation and drainage facilities, and put little concerns on the project quantity and land consolidation efficiency. A partitioning method of land leveling area based on spatial clustering was proposed and tested in this paper. Firstly, the farmland was divided into a regular grid and the grid cells were used as clustering units. The grid cell size followed the present DEM (digital elevation model) resolution, and was 5m &times; 5m in this paper. Secondly, clustering variables were selected to ensure that the natural and agricultural infrastructure conditions in one partition are as consistent as possible. These clustering variables included elevation, relative position to the road, land ownership, and spatial coordinates. Thirdly, the spatial clustering was achieved by two-step cluster algorithm to adapt to different clustering variables. Result schemes were evaluated through three quantitative indexes: project quantity, elevation range and shape index. The comparison of empirical and spatial clustering partition schemes both with 9 partitions shows that: the scheme using clustering method save 24% project quantity and 11% elevation range; the shape index of the scheme using empirical method was 11% lower than the scheme using clustering method. The empirical method balances the influence of various factors and its partitions get more regular shape, but it lacks the consideration of project quantity. In the clustering method, the project quantity and elevation range can be significantly reduced due to the consideration of elevation. Although the factors of road and land ownership are also considered in the clustering method, they only have limited impacts on the shape of partition boundaries. Various partition schemes using spatial clustering method were obtained by adjusting the number of clusters. The output of each partition scheme included partition number, partition distribution and evaluation indexes. The comparison of spatial clustering partition schemes with different numbers of partitions shows that with the increasing of number of partitions, the project quantity gradually reduced, the elevation range increased; the shape index decreased, the partition patches became smaller and regularized, and the complexity of partition border were reduced. The comprehensive evaluation index was calculated by weighted average of these three indicators, and the three corresponding weights were 0.47, 0.37 and 0.16 that were calculated by Analytic Hierarchy Process in this paper. The comprehensive index declines rapidly at first then slowly increase with number of partitions. When number of partitions is 7, the minimum value of comprehensive index appears, which means the partition scheme has the best performance overall. To sum up, using spatial clustering method to partitioning the leveling area can effectively reduce the project quantity and improve the flatness after land consolidation, which are beneficial to reducing investment and can satisfy the future needs of agricultural production. However, the clustering method performs less rational than empirical method in aspect of the regularity and distribution patterns. Therefore, in practice, the clustering scheme could be used as the preliminary foundation, and then the scheme can be adjusted depending on experts experience to give full play to advantages of both methods. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:15
Main heading:Investments
Controlled terms:Agriculture - Association reactions - Cluster analysis - Consolidation - Economics - Farms - Forestry - Land use - Roads and streets - Surveying  - Zoning
Uncontrolled terms:Agricultural productions - Comprehensive evaluation index - Comprehensive indices - Corresponding weights - Digital elevation model - Distribution patterns - Land leveling - Spatial clustering
Classification code:403 Urban and Regional Planning and Development - 405.3 Surveying - 406.2 Roads and Streets - 483 Soil Mechanics and Foundations - 723 Computer Software, Data Handling and Applications - 802.2 Chemical Reactions - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.0 Woodlands and Forestry - 911.2 Industrial Economics - 922 Statistical Methods
DOI:10.3969/j.issn.1002-6819.2015.05.042
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 14>

Accession number:20151400700221
Title:Quantity evaluation method of maturity for Korla fragrant pear
Authors:Lan, Haipeng (1); Jia, Fuguo (1); Tang, Yurong (2); Zhang, Qiang (1); Han, Yanlong (1); Liu, Yang (1)
Author affiliation:(1) College of Engineering, Northeast Agricultural University, Harbin, China; (2) College of Mechanic and Electrical Engineering, Tarim University, Alar, China
Corresponding author:Jia, Fuguo
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:325-330
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In this study, the Korla fragrant pear in the mature period was focused to investigate its mature rule and the variation tendency in the physical and chemical indicators with the increase of the effective accumulated temperature, as well as establish the quantitative assessment method for the maturity level. The pears chosen for the test had no mechanical damages and no pests, and the sizes were basically the same (diameter of 55-65 mm), which were picked on the campus of the Tarim University, with an age of 12 years. The area was located between 80&deg;30'-81&deg;58' E and 40&deg;22'-40&deg;57' N. A total of 1200 pears were for the test, among which 800 were used to establish a mathematical model, picked in 2012 and 2013, and 400 for the validation of the model, picked in 2014. Based on the preliminary selection tests for indicators and the production situation surveys for Korla fragrant pear, the evaluation indexes were fruit hardness, soluble solid content, chlorophyll and vitamin C content, and the variations in various indexes with the increase of effective accumulated temperature during the mature period were detected. The Data was analyzed with the Excel software and SigmaPlot software. A similar variation tendency was found between the indicators, which was a slow change at first and then followed by a rapid change until steady after the mature. Hence, this study set up a mathematical model for the mature rule of the Korla fragrant pear and proposed a quantitative assessment method for the relationships between maturity rule and physical and chemical indicators. It was shown that the model could depict the relationships between the effective accumulated temperature that fragrant pear required during the mature period and the physical and chemical indicators. The model was obvious significant (P&lt;0.0001), and interrelationships among accumulated temperature, maturity level, and physical and chemical indicators could be well evaluated and predicted with the high correlation coefficient (r &gt; 0.998). Furthermore, five levels of effective accumulated temperature (3000, 3200, 3400, 3600 and 3800) were selected to testify the developed mathematical model by calculating the fruit hardness, soluble solid content, chlorophyll content and vitamin C content. For the same fragrant pear, maturity levels indicated by different indicators were similar and the maximum relative deviation was 2.14, which was in an acceptable range. This result also verified the conclusion that the variations in various indicators during the period of mature could be expressed with the same mathematical model. Finally, the results can offer the references in the determination of proper harvest date, the assessment of maturity level, and the prediction of physical and chemical indicators for the Korla fragrant pear; moreover, the results can be helpful in guidance of a timely harvest according to different post-harvest processing methods as well as to the quantitative study of fruit maturity level. The evaluation method of pear maturity proposed in this study can be used to express the mature law of the pear, evaluate maturity level and complete mutual prediction according to effective accumulated temperature and physical and chemical indicators. However, in the practical application it has some limitations for different growing environments and different field management approaches. So the calibration test is required in a particular area before this method is used. Only in this way, the method can accurately express the maturity level of the pear and determine the best picking time. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Fruits
Controlled terms:Chlorophyll - Hardness - Harvesting - Indicators (chemical) - Models
Uncontrolled terms:Accumulated temperatures - Correlation coefficient - Evaluation methods - Korla fragrant pear - Maturity - Postharvest processing - Quantitative assessment methods - Soluble solid content
Classification code:421 Strength of Building Materials; Mechanical Properties - 801 Chemistry - 801.2 Biochemistry - 804 Chemical Products Generally - 804.1 Organic Compounds - 821.3 Agricultural Methods - 821.4 Agricultural Products - 902.1 Engineering Graphics - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2015.05.045
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 15>

Accession number:20151400700188
Title:Effect of subsoiling on root morphological and physiological characteristics of spring maize
Authors:Zhang, Ruifu (1); Yang, Hengshan (2); Gao, Julin (1); Zhang, Yuqin (2); Wang, Zhigang (1); Fan, Xiuyan (2); Bi, Wenbo (2)
Author affiliation:(1) College of Agronomy, Inner Mongolia Agricultural University, Huhhot; Inner Mongolia, China; (2) College of Agronomy, Inner Mongolia University for the Nationalities, Tongliao; Inner Mongolia, China
Corresponding author:Gao, Julin
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:78-84
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Years of small power machincal shallow rotary tillage often causes issues such as shallow top soil layer and thick plough pan in the root layer. Subsoiling is an effective mean to solve the those issues. In this study, effect of subsoiling on root morphological and physiological characteristics of spring maize was investigated in order to understand the mechanism behind the high-yield cultivation of spring maize. In a two-year field experiment (2012 and 2013), two maize varieties of Zhengdan958 and Xianyu335 were planted in soils tilled with different practices including rotary tillage and subsoiling plus rotary tillage. The results showed that subsoiling could significantly (P&lt;0.05) or extremely significantly (P&lt;0.01) increase the maize yield. In the milking and maturity stages, subsoiling also significantly (Xianyu335, P&lt;0.05) or extremely significantly (Zhengdan958, P&lt;0.01) increased the dry root weight of spring maize, especially in soils under 40 cm depth. The root range of inter plant and inter row of two spring maize varieties at the 30 cm soil layer was significantly (P&lt;0.05) higher in the subsoiling plus rotary tillage treatment than in the rotary tillage treatment. In addition, subsoiling increased the root number of per plant and the specific root length. The root activity of spring maize in milking stage in the soil layers below 60 cm was significantly higher in the subsoiling treatment than the rotary tillage treatment, and the difference between both treatments was increased along the depth of the soil. The activities of superoxide dismutase (SOD) and peroxidase (POD) in the treatment of subsoiling+rotary tillage treatment were higher than that of rotary tillage in silking stage under the soil layers below 40 cm. But the malondialdehyde (MDA) content was lower in the former than the latter treatment. Therefore, subsoiling promoted root development, especially increased root dry weight at the deep soil layer and root distribution along the soil profile, and kept high physiological activity, thus resulting in high yield of spring maize. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:19
Main heading:Soils
Controlled terms:Agricultural machinery - Agriculture - Cultivation - Enzymes - Forestry - Morphology - Oxygen - Physiology - Plants (botany)
Uncontrolled terms:Physiological activity - Physiological characteristics - Root - Root distribution - Specific root length - Spring maize - Subsoiling - Superoxide dismutases
Classification code:461.2 Biological Materials and Tissue Engineering - 461.9 Biology - 483.1 Soils and Soil Mechanics - 804 Chemical Products Generally - 804.1 Organic Compounds - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2015.05.012
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 16>

Accession number:20151400700219
Title:Land use scenario simulation with different types of ecological security
Authors:Zhang, Li (1); Zhou, Yapeng (1); Men, Mingxin (1); Xu, Hao (1); Wang, Shutao (1)
Author affiliation:(1) College of Land Resources, Agricultural University of Hebei, Baoding, China
Corresponding author:Men, Mingxin
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:308-316
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:To solve the increasingly serious ecological and environmental problems during the urbanization process, reasonable determination of the land use structure and layout in future is the key. And study on land use scenario simulation under different constraints has been important to scientific planning and decision support. Based on the theory of landscape security patterns and GIS method, ecological security patterns were constructed to maintain the basic ecosystem services of Caofeidian new district which including flood regulation, freshwater supply, biodiversity protection and cultural services. And all these patterns were integrated into a comprehensive ecological security pattern with different security levels. The results indicate that the area of the comprehensive ecological security pattern was 1058.80 km², which accounted for about 53.53% of the study area. Among all levels of ecological security patterns, the area of baseline ecological security pattern that was also considered as the forbidden areas for construction was 312.67 km², accounted for about 15.81% of the study area. And the satisfied and ideal ecological security pattern was 308.15 km²and 437.98 km²respectively. Based on the remote sensing data and GIS method, a land use scenario simulation methodology was developed to integrate CA-MARKOV chain and ecological security pattern at a regional scale. Two scenarios were developed to compare the impact of our land use modeling approach. No ecological conservation scenario is a continuation of the current trends and involves only limited constraints on development. The ecological security pattern conservation scenario (ESP conservation scenario) incorporates ecological security pattern conservation network at different levels. The results indicate that under ESP conservation scenario, there is 74.07 km²newly increasing construction land within the range of overall ecological security patterns, while it is 91.54km²less than no ecological conservation scenario. An increase of 17.47 km²indicates that the ecological security patterns were effectively protected under the ESP conservation scenario. Especially within the range of baseline ecological security pattern, the quantity of newly increasing construction land is 0 under ESP conservation scenario, while it is 31.07 km², indicating an entirely conservation of baseline ecological security pattern under ESP conservation scenario. Comparative analysis of each scenario with landscape metrics indicated that under the ESP conservation scenario, the number of urban patches increased, indicating that a slightly more fragmented landscape. The value of the Shannon's Diversity Index (SHDI) for no ecological conservation scenario and ESP conservation scenario does not change because under both scenarios the number of classes remains the same, and there are no significant differences in the proportional distribution of the area covered by each land use class. The values of the Shannon's Evenness Index (SHEI) are a slight increased under ESP scenario suggests that the landscape composition has become more even, indicating a transition from a dominant land cover class towards a more diversified landscape. PSCoV for cultivated land, water, beach and saltern changed little under both scenarios, but PSCoV for construction land was obviously increased under no ecological conservation scenario, suggests that under no ecological conservation scenario there are some consolidated urbanized areas in which some intra-urban open space are gradually built out, thus creating some larger urban patches and significant variability in patch size. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Ecology
Controlled terms:Biodiversity - Cellular automata - Decision support systems - Ecosystems - Geographic information systems - Land use - Markov processes - Mobile security - Remote sensing
Uncontrolled terms:Biodiversity protection - Caofeidian new district - Ecological conservation - Environmental problems - Fragmented landscapes - Landscape composition - Security patterns - Simulation
Classification code:403 Urban and Regional Planning and Development - 454 Environmental Engineering - 454.3 Ecology and Ecosystems - 461 Bioengineering and Biology - 723 Computer Software, Data Handling and Applications - 723.3 Database Systems - 731.1 Control Systems - 921 Mathematics - 922.1 Probability Theory
DOI:10.3969/j.issn.1002-6819.2015.05.043
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 17>

Accession number:20151400700217
Title:Analysis of process and exploration of mode for rural urbanization based on remote sensing and GIS
Authors:Shi, Manjiang (1); Xie, Yaowen (1); Wei, Jiaojiao (1); Cao, Qi (2)
Author affiliation:(1) College of Resource and Environment, Lanzhou University, Lanzhou, China; (2) College of Civil Engineering and Architecture, Southwest University of Science and Technology, Mianyang, China
Corresponding author:Xie, Yaowen
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:292-300
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:As Nobel economics laureate Stiglitz predicted that China's rapid urbanization which started in twentieth Century 80 has taken a great influence on the process of global human society. In the past 10a, China has experienced the largest urbanization process in the world. Meanwhile, under the guidance of a series of agricultural policy, Chinese rural settlements have dramatically changed on spatial distribution and shape. As large rural population, the rural residential areas still are mainly living form for the agricultural laborers in the future for a long time in China. In order to encourage the coordinated development of regional economy, Chinese government has put forward in the New-type Urbanization promulgated (2014-2020) in March 2014. The New-type urbanization is a major way to solve three-dimensional rural issues and to promote the coordinated development of regional in Chinese rural area. The study area is located in the middle of Hexi Corridor in Gansu province of China (east longitude 100&deg;6'~100&deg;52', latitude 38&deg;39'~39&deg;24'), with the total area of 3.66&times;10³km²and the population up to 18.95&times;10⁴in 2011. In the recent 10a with the rapid expansion of the urban boundary, a large number of cultivated lands around the borough were occupied. In the pastoral interior, so many rural settlements were built and expanded which cause a series of ecological and environmental problems. Considering the above reasons, in order to profoundly understanding the process stage of rural urbanization and the factors of farmers willingness to participate rural urbanization and to explore the suitable model of rural urbanization, this thesis uses the Ganzhou district in Zhangye city, Gansu province as an example, combined with temporal and spatial changes of rural residents as well as the farmers' urbanization willingness survey, to analysis the factors of rural urbanization and to explore rural urbanization possible mode in future. Therefore, this paper first extracts the spatial distribution information of rural urbanization based on the Landsat TM/OLI in 1990, 2004, 2014 images in Ganzhou District, and then uses GIS spatial analysis and statistical methods to analyze variation law and reveal the process and characteristics of rural residential in Ganzhou District. Later, we applied Logistic regression method to explore the factors base on the wishes of farmers. Finally we construct the urbanization pattern of Ganzhou district based on the above results. The main results of the study were as follows: 1) from 1990 to 2014, the number and area of rural residential Ganzhou district continues increasing, especially in the latest 10 years the rural residential area was significantly larger than 15 years ago, and the spatial agglomeration effect is obvious. From this result, we can infer that the urbanization process has accelerated significantly for nearly 10 years in the study area, and the process has a significant difference in space. According to the different stages of urbanization in Ganzhou district, we divided into 3 stages including mature period, growth period and incubation period; 2) Logistic regression found that the main factors affecting farmers to take part in urbanization as follows: new skills training education, farmer's age, the number of family to migrant workers, the choice of hospital, per capital arable land, whether to support the land exchange. The primary factor of peasant household willingness to participate in new-type urbanization is concerns of survival skill after urbanization. The additional factors include their characteristics and status of rural health, such as the farmers' age, education etc. Another important factor is the new land policy factors related to new-tape urbanization. The seven factors were classified into non-agricultural skill type, combination agricultural and industrial type and agricultural dominant; 3) According to the different urbanization stages and types of farmer urbanization, we constructed various models of rural urbanization to match with the land exchange model and rural livelihood model. This study specified the process of rural urbanization and provided the theory basis and the practice instruction for scientific and reasonable rural urbanization policymaking. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:20
Main heading:Agriculture
Controlled terms:Economics - Geographic information systems - Housing - Land use - Models - Regional planning - Regression analysis - Remote sensing - Rural areas - Space optics  - Spatial distribution
Uncontrolled terms:Environmental problems - Ganzhou district - Logistic regression method - Logistic regressions - Remote sensing and GIS - Rural residential areas - Rural urbanizations - Temporal and spatial changes
Classification code:403 Urban and Regional Planning and Development - 723.3 Database Systems - 731.1 Control Systems - 741.1 Light/Optics - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 902.1 Engineering Graphics - 922.2 Mathematical Statistics - 971 Social Sciences
DOI:10.3969/j.issn.1002-6819.2015.05.041
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 18>

Accession number:20151400700197
Title:Synchronous control method for three-phase combined inverters
Authors:Zheng, Zhiyao (1); Sun, Qinfei (1); Wang, Jiangbo (1); Yang, Rengang (1)
Author affiliation:(1) College of Information and Electrical Engineering, China Agricultural University, Beijing, China
Corresponding author:Wang, Jiangbo
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:146-151
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The topology of three-phase inverters can divide into a three-phase bridge structure and a single-phase combined structure. Three-phase combined inverters have their own advantages compared to normal three-phase bridge inverters, such as enhanced functionality, more choices for power resources, and simple maintenance, and so on. Therefore, it is worthwhile to study the technology of three-phase combined inverters, especially the study of the synchronous control method for three-phase combined inverters. In this paper, the synchronous control method for three-phase combined inverters was studied in the island operation and the process of pre-synchronization between island and grid-connected operations based on the Y/&utri; connection of three single-phase energy storage inverters. When in the island operation, a synchronous control method of master/slave mode through a time benchmark synchronization and a phase adjustment synchronization was proposed based on a CAN (controller area network) bus communication. With the help of a CAN bus, an automatic network was designed to determine the A, B, and C-phase for the three inverters. A synchronization frame was designed and sent every 20 ms by the A-phase inverter, which was taken as the reference phase and corrected the phase error of the sine signal, to make sure that the time benchmark synchronized and the phase adjustment synchronized. And on this basis, when in the process of pre-synchronization between island and grid-connected operations, a synchronous control method of improved PLL (phase-locked loop) through frequency adjustment synchronization and logic judgment controller was proposed based on a SOGI (second-order generalized integrator). The improved PLL added a virtual PLL compared to the traditional PLL for the calculation of the real gird voltage phase angle. And the logic judgment controller used the difference between the output voltage phase angle of the inverters and the real gird voltage phase angle as the input, which implemented the smooth handoff from the island mode to a grid-connection. The actual experiments of the three-phase combined inverters were finished to verify the proposed synchronous control methods. The controller of the inverters was developed on the popular digital processor, which is TMS320F28335 from Texas Instrument. The CAN bus baud rate was set to 125 kB/s. The reference voltage was set to 220 V, 50 Hz, and the capacity of each inverter was 8kVA. As the result, when in the island operation, the proposed method implemented the three-phase output voltages of three-phase combined inverters and always kept the phase difference for 120&deg;, and the average of the unbalance of three phase voltage in 5 minutes was 0.4%, which is less than the specified value 1.3% and meets the standards. When in the process of pre-synchronization between island and grid-connected operations, the maximum of the unbalance of three phase voltage in 5 minutes was 2.1%, which is less than the specified value of 2.6% and meets the standards. Therefore, both in the island operation and the process of pre-synchronization between island and grid-connected operations, the results showed that the synchronous control method for three-phase combined inverters is reliable and useful. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:18
Main heading:Controllers
Controlled terms:Control system synthesis - Electric energy storage - Electric inverters - Electricity - Energy storage - Locks (fasteners) - Phase locked loops - Synchronization - Topology - Voltage measurement
Uncontrolled terms:CAN bus - Grid-connected operation - Improved phase-locked loops - Island operation - Synchronous control - Three-phase combined inverters
Classification code:601.3 Mechanisms - 701.1 Electricity: Basic Concepts and Phenomena - 702 Electric Batteries and Fuel Cells - 713.5 Electronic Circuits Other Than Amplifiers, Oscillators, Modulators, Limiters, Discriminators or Mixers - 731.1 Control Systems - 732.1 Control Equipment - 921.4 Combinatorial Mathematics, Includes Graph Theory, Set Theory - 942.2 Electric Variables Measurements
DOI:10.3969/j.issn.1002-6819.2015.05.021
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 19>

Accession number:20151400700181
Title:Validation and analysis of fluid-structure interaction between rotary harrow weeding roll and paddy soil
Authors:Qi, Long (1); Liang, Zhongwei (2); Ma, Xu (1); Tan, Yongxin (2); Jiang, Likai (2)
Author affiliation:(1) Key Laboratory of Key Technology on Agricultural Machine and Equipment (South China Agricultural University), Ministry of Education, Guangzhou, China; (2) College of Engineering, South China Agricultural University, Guangzhou, China
Corresponding author:Ma, Xu
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:29-37
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to investigate the variance of the resistance on the weeding roll and the dynamic behavior of the paddy soil in the condition of paddy field, LS-DYNA, the explicit analysis module of ANSYS, was adopted to simulate and analyze the operating process of the rotary harrow weeding roll in this paper. The soil model was built by MAT147 in LS-DYNA, an elastic-plastic model using the Mohr-Coulomb yield criterion. In order to simulate the paddy field in reality when weeding, a soil-water combined model was established using the Multi-Material ALE (Arbitrary Lagrange-Euler) algorithm, which was considered to be an ALE finite element model. By using the Multi-Material ALE algorithm, the different materials were allowed to exchange and transport in the ALE mesh. The interaction process between the weeding roll and the soil-water model was analyzed by the Fluid-Structure Interaction algorithm. Type of soil (factor A), thickness of water layer (factor B) and rotary velocity of weeding roll (factor C) were selected as three factors of the orthogonal simulation experiment with reciprocal action to explore the effect regularity on coupling stress and destruction of soil caused by the factors and the primary reciprocal actions between each factor. The comprehensive evaluation of simulations results were carried out by the multi-objective optimization design method. The results show that in three types of soils the optimal performance of the weeding roll could be obtained when the water layer thickness was 60 mm and the weeding roll rotary velocity was 160 r/min. The sequence of factors in affecting the coupling stress was type of soil &gt; thickness of water layer &gt; type of soil &times; thickness of water layer &gt; type of soil &times; rotary velocity of weeding roll &gt; rotary velocity of weeding roll &gt; thickness of water layer &times; rotary velocity of weeding roll. The coupling stress was reported to be the minimal in the condition of clay soil, and the maximal in the condition of sandy clay soil. The coupling stress was reported to decrease slightly with the increasing thickness of water layer, and increase first and then decrease within a narrow range with the increasing rotary velocity of weeding roll. The sequence of factors in affecting the destruction of soil was type of soil &gt; rotary velocity of weeding roll &gt; type of soil &times; thickness of water layer &gt; type of soil &times;rotary velocity of weeding roll &gt; thickness of water layer &gt; thickness of water layer &times; rotary velocity of weeding roll. The destruction of soil was reported to be the minimal in the condition of clay soil, and the maximal in the condition of sandy clay soil. The destruction of soil was reported to drop slightly first and then rise with the increasing thickness of water layer, and increase with the increasing rotary velocity of weeding roll. The field trail and the soil box test were carried out to validate the simulation results. The deviation between the torsion derived from the coupling stress and the one obtained from the field trail was 8.84%, and the deviation between the destruction of soil obtained from the simulation and the one from soil box test was 9.86%, and the deviation between the score of the comprehensive evaluation obtained from the simulation and the one from experiments was 7.02%. The results of field trail and soil box test are basically coordinated with the simulation, which prove the methods of modeling and simulation adopted in this research. The results provide references to the performance and the efficacy of the portable paddy field weeder operating in different rice growing districts and working conditions with different working parameters. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:22
Main heading:Soils
Controlled terms:Agricultural machinery - Clay - Cutting - Elastoplasticity - Finite element method - Fluid structure interaction - Multiobjective optimization - Soil moisture - Soil structure interactions - Soil testing  - Velocity - Weed control
Uncontrolled terms:Arbitrary lagrange euler - Comprehensive evaluation - Elastic -plastic models - Model and simulation - Mohr Coulomb yield criterion - Multi-material ALE algorithm - Optimal performance - Paddy fields
Classification code:483.1 Soils and Soil Mechanics - 483.2 Foundations - 604.1 Metal Cutting - 803 Chemical Agents and Basic Industrial Chemicals - 821.1 Agricultural Machinery and Equipment - 921.5 Optimization Techniques - 921.6 Numerical Methods - 931.1 Mechanics
DOI:10.3969/j.issn.1002-6819.2015.05.005
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 20>

Accession number:20151400700180
Title:Parameters' optimization and verification for processing tomato fruit-seedling separation
Authors:Wang, Lihong (1); Liang, Rongqing (2); Qin, Jinwei (1); Kan, Za (1); Li, Chengsong (1); Zhu, Xingliang (1)
Author affiliation:(1) College of Mechanical and Electronic Engineering, Shihezi University, Shihezi, China; (2) Academy of Agricultural Machinery Sciences, Jinan; Shandong, China
Corresponding author:Kan, Za
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:23-28
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to meet the needs of localization in China about the self-propelled tomato harvester, two methods of CCD (central composite design) and RSM (response surface methodology) were employed to optimize the performance of fruit-seedling separation. The testing device of fruit-seedling separation was consisted of wiggler (including eccentric block, exciter and timing belt pulleys), separation roller, separation tine and damper components. Rotary motion from the power source was turned into a variable speed rotary motion by the eccentric drive mechanism of the wiggler, and passed to the separation roller to achieve the fruit-seedling separation through its periodic oscillations. When the testing device worked, tomato plants were transported to the fruit-seedling separation device by the conveying chain and got the separation of fruit and vine. The processing tomatoes were sent to picking boxes through conveying chain after being separated. The velocity of conveying chain and the wiggler speed could be adjusted through the transducer-controlled drive motor. The harvesting productivity was controlled by the amount of tomato plants fed and the separation time in the separation roller. The determination and calculation of fruit-seedling separation rate and fruit damage rate was based on the reference to the tomato harvester work quality standards (NYT 1824-2009). The productivity, wiggler speed and chain velocity were taken as 3 independent variables and fruit-seedling separation rate and fruit damage rate were the responsive variables. The relationship between these 3 variables and 2 responsive variables was explored by the RSM. The mathematical regression model was established by using the CCD method and the influencing rules of the factors were explored. The experimental parameters were optimized by using the Design Expert 9.0 software. The optimal combination of separation parameters was determined, under the condition that the tomato separation rate and tomato damage rate both met the quality standard for tomato harvester (NYT1824-2009). The result showed that, in terms of significant degree, the influence factors of separation rate were the wiggler speed, the productivity and the chain velocity, respectively, and the influence factors of damage rate were the wiggler speed, the chain velocity and the productivity, respectively. The optimal combination of parameters was 34.2 t/h of the productivity, 409.3 r/min of the wiggler speed and 0.71 m/s of the chain velocity. The rates of tomato separation and damage predicted by the models were 96.27% and 2.12%, respectively. The model validation tests had been repeated for 5 times on processing tomato fruit-seedling separation device by using the optimization results in the laboratory of agricultural machinery of Xinjiang Production and Construction Corps. Both of the relative errors between the experimental and predicted values of fruit-seedling separation rate and fruit damage rate were less than 5%, which indicated a reasonable choice of optimization conditions. Predicted value of fruit-seedling separation rate was 96.27%, which was greater than 95.5%, and predicted value of tomato damage rate was 2.12%, which was less than 5%. It met the threshold limit values of 95.5% and 5% about operating quality for tomato harvester (NYT1824-2009). Therefore, the prediction model of separation performance established was appropriate and the optimization separation parameters obtained were also feasible. The test was based on double eccentric vibration generator device and only Riegel 87-5 was selected as the testing object. Further study on fruit-seedling separation properties under different kinds of processing tomatoes and different types of vibration generators was recommended. This study showed that fruit-seedling separation parameters obtained by the RSM were feasible, which might provide a theoretical basis for further research of fruit-seedling vibration separation technology of processing tomato. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:15
Main heading:Source separation
Controlled terms:Agricultural machinery - Belt drives - Chain conveyors - Chains - Fruits - Harvesters - Optimization - Productivity - Quality control - Regression analysis  - Rollers (machine components) - Separation - Speed - Surface properties - Velocity - Wigglers
Uncontrolled terms:Central composite designs - Experimental parameters - Optimization conditions - Processing tomatoes - Response surface methodology - Separation performance - Separation technologies - Threshold limit values
Classification code:601.2 Machine Components - 602.1 Mechanical Drives - 692.1 Conveyors - 716.1 Information Theory and Signal Processing - 802.3 Chemical Operations - 821.1 Agricultural Machinery and Equipment - 821.4 Agricultural Products - 913.1 Production Engineering - 913.3 Quality Assurance and Control - 921.5 Optimization Techniques - 922.2 Mathematical Statistics - 931.1 Mechanics - 932.1.1 Particle Accelerators - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2015.05.004
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 21>

Accession number:20151400700199
Title:Investigation method for crop area using remote sensing sampling based on GF-1 satellite data
Authors:Liu, Guodong (1); Wu, Mingquan (3); Niu, Zheng (3); Wang, Changyao (3)
Author affiliation:(1) National and Local Joint Engineering Laboratory of Traffic Civil Engineering Materials, Chongqing Jiaotong University, Chongqing, China; (2) School of Civil and Architecture Engineering, Chongqing Jiaotong University, Chongqing, China; (3) State Key Laboratory of Remote Sensing Science, Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences, Beijing, China
Corresponding author:Wu, Mingquan
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:160-166
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The Chinese GF-1 satellite is a new high spatial resolution satellite launched on April 26, 2013. It was equipped with two types of sensors. One is the wide field view sensor (WFV sensor); the other is the panchromatic and multispectral sensor (PMS sensor). The WFV sensor can acquire multispectral image in blue, green, red, and near-infrared bands with 16 meters spatial resolution and 4 days temporal resolution. The PMS sensor can acquire a panchromatic and multispectral image with 41 days temporal resolution. The spatial resolution of a panchromatic image acquired by the PMS sensor is 2 meters, while the spatial resolution of a multispectral image acquired by the PMS sensor in blue, green, red, and near-infrared bands is 8 meters. According to the characteristics of a GF-1 satellite image, a method for mapping crops using remote sensing and sampling technology was proposed. There are four kinds of summer harvest crops in our study area of Dongtai county. There are winter wheat, barley, rapeseed and vegetables. According to the crop's phenology calendar information of this study area, there are three key periods for the identification of crops. In later March, winter wheat and barley are in the growing season, while rapeseed is in the flowering period. In early April, barley and rapeseed are in the flowering period, while winter wheat is in the growing season. In early and middle May, winter wheat is in the flowering stage, while canola and barley are at maturity. So the 16 meters resolution WFV sensor data acquired in those periods were used to classify those crops. First, that data was preprocessed for ortho rectification, geometric correction, and atmospheric correction. Then multi-days NDVI were calculated and was used to generate a false color composite image. In the false-color composite image, we found that those kinds of crops exhibited distinctly different colors. Vegetables were yellow, canola was light red, grain crop including winter wheat and barley is dark red. So those crops can be easily classified using the maximum likelihood method. Then we converted the classification map to vector files and calculated a MORAN index in this study area using ARCGIS. The MORAN index in this study area was 0.78, and the distance threshold was 5480 meters. The resolution of WFV data was 16meters, so 5440meters (340pixels of WFV) was set to the size of the sampling units. Then 10 sampling units were selected using the MPPS method based on the proportional information of each crop for each unit which was calculated using the block statistics function of ARCGIS. After that, the high spatial PMS sensor data of those 10 sampling units were resized out. In the high spatial false-color composite PMS sensor image, we found that those crops also had different colors. Rapeseed was light red, wheat was dark red, and vegetables were gray. So the crops in each of the sampling units were classified with the maximum likelihood method using the field investigation data as the training sample. Finally, according to the MPPS method, the total areas of each crop in the study area and CV were calculated. The area of crops, rapeseed, and Vegetables of 2014 in Dongtai using temporal WFV data was 582.74 km², 226.7873 km^2,and 271.288 km². Compared with the data published by the Dongtai County Farm Bureau, the errors of crops, rapeseed, and vegetables using temporal WFV data were-9.9%,-2.8% and-15.2%. The area of crops, rapeseed, and vegetables of 2014 in Dongtai County using remote sensing and sampling methods was 638.6318 km², 244.8 km², and 322.9601 km². Compared with the data published by the Dongtai County Farm Bureau, the errors of crops, rapeseed, and vegetables using remote sensing and sampling methods were 3%, 5%, and 1%. Those results showed that this method could classify crops, rapeseed, and vegetable areas effectively. High mapping precision of 90% was acquired. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:25
Main heading:Crops
Controlled terms:Color - Errors - Forestry - Image acquisition - Image resolution - Infrared devices - Mapping - Maximum likelihood - Oilseeds - Remote sensing  - Sampling - Satellite imagery - Satellites - Vegetables
Uncontrolled terms:Atmospheric corrections - Geometric correction - Investigation methods - Maximum likelihood methods - Multispectral images - Multispectral sensors - Ortho-rectification - Planting areas
Classification code:655.2 Satellites - 723 Computer Software, Data Handling and Applications - 731 Automatic Control Principles and Applications - 731.1 Control Systems - 741 Light, Optics and Optical Devices - 742 Cameras and Photography - 821.0 Woodlands and Forestry - 821.4 Agricultural Products - 902.1 Engineering Graphics - 921 Mathematics - 922.1 Probability Theory
DOI:10.3969/j.issn.1002-6819.2015.05.023
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 22>

Accession number:20151400700193
Title:Spatial variability of soil salinity based on multi-source data for typical zone of flood area of the Yellow river in central China
Authors:Wu, Yakun (1); Liu, Guangming (2); Yang, Jingsong (2); Yu, Shipeng (2)
Author affiliation:(1) School of Energy and Environment, Anhui University of Technology, Maanshan, China; (2) State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China
Corresponding author:Liu, Guangming
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:115-120
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Salinization and alkalinization are two of important land degradation processes in flood area of the Yellow River in central China. A synthesized model for assessment of regional soil salinity was established based on multi-source data including soil salinity, topographical variable, the groundwater level and mineralization degree, vegetation and other factors to the soil salinization. A total of 101 soil columns were sampled from the study area using grid sampling method, and then analyzed for soil electrical conductivity (ECe) and other soil properties. Auxiliary data used in this study to interpret variability of soil salinization were Landsat 5 TM data, apparent electrical conconductivity (ECa) measured using an electromagnetic induction instrument (EM38), altitude derived from topographic map, the groundwater table and mineralization degree and soil pH. The spatial variability of soil salinity was assessed in Fengqiu County, Henan Province, China. Classification and regression tree was applied to obtain the relationships between ECe (0-120 cm) and the auxiliary data. The results showed that ECa accounted for the major proportion of model prediction from multi-source data in classification and regression tree model of total soil layer. Generally, ECaH (apparent soil electrical conductivity from EM38 horizontal mode) and spectral index (dvi: difference vegetation index, bi: soil index, int2: intentity, int1: intentity, ndvi: normalized difference vegetation index, si2: soil index and si1: soil index) were common variable for 0-60cm soil layer. For the 0-30 cm depth, plant index (ndvi and dvi), soil index (si1, si2 and bi) and intentity (int1 and int2) had the highest influence on the model prediction followed by ECa. Plant index (dvi) accounted of more than 50% for 0-60 cm soil layer used in the model. Meanwhile, for &ge;60-120 cm, ECaV (apparent soil electrical conductivity from EM38 vertical mode) was the most important variable used in regression tree model. Validation of the predictive models at each depth resulted in determination coefficient (R²values) ranging from 0.52 to 0.65. The root mean square error (RMSE) value ranged between 0.72 to 1.27 dS/m. The model for the evaluation of the soil salinity of 0-60 cm was better than that of soil layer of &ge;60-120 cm. The mean of soil salinity varied from 1.26 to 1.61 dS/m from top to the bottom of soil profiles, and the soil salinity at the bottom was the highest in total soil profile, which indicated soil salinity accumulation at the bottom. ECe varied from 0.79 to 3.68 dS/m from top to the bottom of soil profiles. Coefficient of variation of soil salinity at each soil 1ayer was from 0.22 to 0.28 and exhibited the moderate spatial variability. The groundwater table varied from-14.0 m to-0.2 m. Coefficient of variation of groundwater table was 0.7 which exhibited the moderate spatial variability. The mean of groundwater electrical conductivity was 1.44 dS/m, which was similar to soil electrical conductivity. The mean of pH value varied from 8.88 to 9.28 and increased with increasing soil depth. Digital maps of ECa (horizontal and vertical modes) along with other environmental variables were used to predict the spatial distribution of ECe. The high values of soil salinity were mainly distributed in the northern and southern area along the Yellow river in the study area, especially the southeast region. The synthesized model based on multi-source data had high precision for assessment of regional soil salinity. Thus, the application of this technique provides a new method to improve soil salinization and soil quality in the flood area of the Yellow River in central China. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:24
Main heading:Soils
Controlled terms:Electric conductivity - Electromagnetic induction - Floods - Forecasting - Forestry - Groundwater - Maps - Mean square error - Mineralogy - Models  - Optical waveguides - Regression analysis - Remote sensing - Rivers - Salinity measurement - Soil surveys - Soil testing - Trees (mathematics) - Vegetation
Uncontrolled terms:Apparent electrical conductivity - Apparent soil electrical conductivities - Classification and regression tree - Classification and regression tree models - Determination coefficients - Normalized difference vegetation index - Soil electrical conductivity - Spectral indices
Classification code:444.1 Surface Water - 444.2 Groundwater - 482 Mineralogy - 483.1 Soils and Soil Mechanics - 701.1 Electricity: Basic Concepts and Phenomena - 717.2 Optical Communication Equipment - 731.1 Control Systems - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.0 Woodlands and Forestry - 902.1 Engineering Graphics - 914.1 Accidents and Accident Prevention - 921.4 Combinatorial Mathematics, Includes Graph Theory, Set Theory - 922.2 Mathematical Statistics
DOI:10.3969/j.issn.1002-6819.2015.05.017
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 23>

Accession number:20151400700187
Title:Measurement of softness abrasive flow field based on particles image velocimetry
Authors:Li, Chen (1); Shan, Yingying (3); Li, Zhian (1); Zhang, Zheng (2)
Author affiliation:(1) Department of Quality and Safety Engineering, China Jiliang University, Hangzhou, China; (2) Key Laboratory of E&amp;M (Zhejiang University of Technology), Ministry of Education &amp; Zhejiang Province, Hangzhou, China; (3) School of Mechanical Engineering, Zhejiang Institute of Mechanical &amp; Electrical Engineering, Hangzhou, China
Corresponding author:Shan, Yingying
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:71-77
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:During the course of mold manufacture, lots of structural surfaces are involved, which are of complicated structure and tiny scale. Owing to the special profile of a structural surface, its finishing cannot be realized by the traditional method; so a softness abrasive flow ultraprecision machining method is proposed for mold structural surface finishing. Because of the weak viscosity of softness abrasive flow, it could develop turbulent flow easier than viscous fluids. The best finishing result can be obtained with the turbulent softness abrasive flow, so the flow pattern recognition of softness abrasive flow is necessary. Taking the structural surface of vehicle mold as the study object, a realizable k-&Epsilon; double-equation turbulent model is used to describe a softness abrasive flow field. Based on the finite element analysis method, computational fluid dynamics (CFD) software was used to simulate the softness abrasive flow field. With the numerical simulation, distributions of dynamic pressure, velocity vector, and turbulent dissipation rate of the softness abrasive flow field were obtained; and the evolutionary process of the softness abrasive flow was showed by simulating different moments of particle motion trails, and the feasibility of a softness abrasive flow finishing method has been proved by these simulation results. Based on the similarity theory, a model of flow passage which was made of plexiglass was designed, three typical areas of the flow passage were selected for measuring the characteristics of the flow field, and the measurement platform of the softness abrasive flow field was constructed by using particle image velocimetry (PIV) technology. With the measurement platform, distribution of particle motion, velocity vector, and flow field vorticity were derived. From the particle motions, it was shown that the particles in the flow field were moving irregularly, particles can collide with the surface randomly, and the removal finishing can be realized; particle motion trails are observed from the velocity vector distribution, it was shown that particle trails in the flow field were votex, which was according to the features of turbulence, and this was conducive to the mold structural surface finishing. The vorticity distribution of the flow field illustrates that the softness abrasive flow has high vorticity energy, and it was helpful for increasing materials removal. Contrasting with simulation and measurement results, the softness abrasive flow field in this situation is turbulent, and the ultraprecision machining of mold structural surface can be realized by the softness abrasive flow in this state. A finishing platform which oriented to mold the structural surface was constructed, with the turbulent softness abrasive flow, the finishing experiment which was designed to mold the structural surface was carried out. The experiment results showed that SAF method can improve the surface quality of a mold structural surface without changing the morphology, and the machined roughness of a mold structural surface can be reduced to 27 &mu;m. Experimental results have demonstrated the effectiveness of a softness abrasive flow finishing method. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:21
Main heading:Computational fluid dynamics
Controlled terms:Abrasives - Automobile manufacture - Computation theory - Finishing - Finite element method - Flow fields - Flow patterns - Molds - Numerical methods - Pattern recognition  - Surface treatment - Turbulence - Velocimeters - Velocity measurement - Viscosity - Vorticity
Uncontrolled terms:Distribution of particles - Finite element analysis method - Image velocimetry - Particle image velocimetries - Simulations and measurements - Structural surfaces - Turbulent dissipation rates - Velocity vector distribution
Classification code:539 Metals Corrosion and Protection; Metal Plating - 606.1 Abrasive Materials - 631.1 Fluid Flow, General - 662.1 Automobiles - 716 Telecommunication; Radar, Radio and Television - 802 Chemical Apparatus and Plants; Unit Operations; Unit Processes - 813.1 Coating Techniques - 816.2 Plants and Machinery for Plastics and Other Polymers - 921 Mathematics - 921.6 Numerical Methods - 931 Classical Physics; Quantum Theory; Relativity - 943.3 Special Purpose Instruments
DOI:10.3969/j.issn.1002-6819.2015.05.011
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 24>

Accession number:20151400700196
Title:Development of real-time detecting device for nitrogen concentration of liquid fertilizer
Authors:Li, Jianian (1); Li, Yunqing (1); Yang, Qiliang (1); Lei, Longhai (1); Wu, Zhenzhong (1)
Author affiliation:(1) Faculty of Modern Agricultural Engineering, Kunming University of Science and Technology, Kunming, China
Corresponding author:Yang, Qiliang
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:139-145
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:For the realization of real-time detection of nitrogen concentration in the process of automatic mixed liquid fertilizer, a detection device was designed, which was mainly composed of a nitrate ion selective electrode, an electrode signal conditioning circuit, a temperature sensor, and a data acquisition and display circuit. There was a one-to-one correspondence between the response potential of a nitrate ion selective electrode and nitrate ion concentration. For this reason, the detection device could obtain the level of nitrate ion concentration by detecting the electrode's response potential, and then the nitrogen concentration of liquid fertilizer had been acquired indirectly. Measuring accuracy for the electrode's potential was a key influence factor of the device's performance. A 1 mV error of the electrode's potential led to a 4% concentration measuring error of monovalent ions. To evaluate the device's measuring accuracy for an electrode's potential, the electrode had been placed in a series of prepared potassium nitrate solutions whose NO<inf>3</inf>^-concentration were 10^-6, 5&times;10^-6, 10^-5, 5&times;10^-5, 10^-4, 5&times;10^-4, 10^-3, 5&times;10^-3, 10^-2, 5&times;10^-2, and 10^-1mol/L respectively, and the response potential of the electrode was measured by the device and a standard millivoltmeter PHS-3CT which was used as the comparative reference respectively, and it was known from the test results that the device's measuring result for the electrode's potential in each NO<inf>3</inf>^-concentration was closed to that of PHS-3CT, and its maximum and minimum relative error were 5.2% and 1.2% respectively. Meanwhile, the response potential of the electrode would produce a temperature drift when the temperature varied, which would result in a measuring error of ion concentration. For reducing the influence of temperature variation, the electrode's temperature variability had been analyzed with 25 as a reference, by measuring its response potential in a series of prepared solutions with different NO<inf>3</inf>^-concentrations in the range of 10^-5-10^-1mol/L and different temperatures within the scope of 5-45. The results showed that the response potential of the electrode had a linear change with the temperature difference of the solution to be examined and the maximum variability rate of the potential was 8.8%. Based on the response potential of the electrode measured in a series of prepared solutions with different NO<inf>3</inf>^-concentrations and different temperatures, a temperature parameter model had been established by using the method of the least squares fitting step by step. Verification experiments of the temperature parameter model had been carried out, by using three kinds of prepared potassium nitrate solutions whose NO<inf>3</inf>^-concentration were 4&times;10^-1, 4&times;10^-2and 4&times;10^-3mol&middot;L^-1severally, and it turned out that the average relative measurement error and the maximum relative measurement error of the temperature parameter model were 4.49% and 9.2% separately. Furthermore, there may be some interfering ions (such as Cl^-, SO<inf>4</inf>^2-, H<inf>2</inf>PO<inf>4</inf>^-and HPO<inf>4</inf>^2-) in a mixed liquid fertilizer in addition to NO<inf>3</inf>^-, and the nitrate ion selective electrode had cross sensitivity. It would allow the electrode's response for interfering ions to come into being, which could bring about some impact on the device's measuring results. In order to determine the degree of influence of the interfering ions for the device's measuring results, the fixed interference method had been used to measure the electrode's selectivity coefficient for Cl^-, SO<inf>4</inf>^2-, H<inf>2</inf>PO<inf>4</inf>^-, and HPO<inf>4</inf>^2-respectively. The results indicated that the selectivity coefficient for 4 interfering ions were 5.1&times;10^-2, 1.0&times;10^-4, 2.0&times;10^-4and 5.0&times;10^-5singly, and that the bigger the selectivity coefficient was, the greater the impact of interfering ions on the electrode; moreover, it was found from experiments that the effects of interfering ions on the electrode weakened gradually with the decrease of the interfering ions concentration, and the measuring error of the device caused by Cl^-was 4% when Cl^-: NO<inf>3</inf>^-=1:100, that was to say, a small amount of interfering ions in a liquid fertilizer could not constitute a significant effect for the measured results. From the above, the device developed could meet the application requirements of a nitrogen concentration test in the process of automatically mixed fertilizer in engineering. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:23
Main heading:Electrodes
Controlled terms:Concentration (process) - Data acquisition - Display devices - Fertilizers - Interferometry - Ion selective electrodes - Ions - Least squares approximations - Liquids - Measurement errors  - Nitrates - Nitrogen - Nitrogen fertilizers - Real time control - Signal conditioning circuits - Solution mining
Uncontrolled terms:Application requirements - Detection device - Fixed interference method - Nitrate ion selective electrode - Nitrogen concentrations - Selectivity coefficient - Temperature differences - Temperature variability
Classification code:502.1 Mine and Quarry Operations - 704.1 Electric Components - 722.2 Computer Peripheral Equipment - 722.4 Digital Computers and Systems - 723.2 Data Processing and Image Processing - 731 Automatic Control Principles and Applications - 732 Control Devices - 801 Chemistry - 801.4.1 Electrochemistry - 802.1 Chemical Plants and Equipment - 802.3 Chemical Operations - 804 Chemical Products Generally - 804.2 Inorganic Compounds - 921.6 Numerical Methods - 922 Statistical Methods - 931.2 Physical Properties of Gases, Liquids and Solids - 941.4 Optical Variables Measurements
DOI:10.3969/j.issn.1002-6819.2015.05.020
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 25>

Accession number:20151400700182
Title:Optimal design and experiment of long axis centrifugal pump based on differ head
Authors:Zhu, Rongsheng (1); He, Bo (1); Fu, Qiang (1); Wang, Xiuli (1); Zhang, Liangliang (1)
Author affiliation:(1) Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang, China; (2) Jiangsu National Pump Co. Ltd., Zhenjiang, China
Corresponding author:Zhu, Rongsheng
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:38-45
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to make a long axis centrifugal pump have the characteristics of high-efficiency under different conditions, this article investigated the optimization design of a 500GJC-32.3&times;3 long axis centrifugal pump. We calculated the parameters of a long axis centrifugal pump impeller according to the traditional method, optimization design of 7 parameters: impeller inlet diameter, blade number, blade wrap angle, blade outlet angle, impeller outlet width, impeller outlet with a mean diameter and impeller outlet tilt angle were done by using the orthogonal design method. With the result of an orthogonal test method studied by range analysis, we obtained the primary and secondary order of the impeller geometric parameters which affect the head and efficiency of a long axis centrifugal pump. The primary and secondary order of the factors affecting the efficiency of the design point is blade number &gt; blade outlet angle&gt; impeller outlet width&gt; impeller outlet tilt angle&gt; blade wrap angle&gt; impeller outlet with a mean diameter &gt; impeller inlet diameter, The primary and secondary order of the factors affecting the head of the design point is &gt; blade outlet angle &gt; impeller outlet tilt angle &gt; impeller outlet with a mean diameter &gt; blade wrap angle &gt; impeller outlet width &gt; impeller inlet diameter, According to the orthogonal results, what is needed to get the final optimal combination are as follows: impeller inlet diameter is 345 mm, blade number is 6, blade wrap angle is105&deg;, blade outlet angle is 25&deg;, impeller outlet width is 75 mm, impeller outlet with a mean diameter is 550 mm, impeller outlet tilt angle is 25&deg;. Based on results of the orthogonal design, considering the affections of primary and secondary order of the factors on the efficiency and head, using the control variable method, greater impact parameters on pump performance must be chosen to optimize. Ignoring the effect of the blade number, 6 blades were selected. Then, we changed the unlimited blade number theoretical head of impeller shroud and unlimited blade number theoretical head of impeller hub on the basis of a head difference theory, controlled the secondary parameters unchanged, and then changed blade outlet angle to make all streamlines have the same limited blade number theoretical head. Five different impellers were designed according to the above method, 3D models of different impellers were made by using Pro/E software, models were meshed by using ICEM software, and different impellers were numerically simulated by using ANSYS CFX software. Through comparing the simulation results, we found that the impellers based on the head difference theory had good hydraulic performance, and that an appropriate head coefficient of impeller hub can get the best hydraulic performance. When the appropriate head coefficient is equal to 1.1, a long axis centrifugal pump can get better hydraulic performance. Through the optimization, a better set of parameters were obtained, 3D models were made on the basis of parameters, and the flow field of a long axis centrifugal pump was analyzed by using numerical simulation technology. By comparing numerical results with experimental results, the result indicated that the two results share the same trend, and the maximum errors of head, efficiency, and axis rate were 4.02%, 5.58% and 3.59% respectively, and when the pump was operating under conditions of (0.8-1.2) times designed rate of flow, the errors of head, efficiency, and axis rate are relatively small. The experimental results showed that when the pump was operating at the designed rate of flow, its head was above 97 m, its efficiency was above 82%, the highest efficiency point was 83.22% which occurred at about 1.1 times designed rate of flow, and the curves had a wider high efficiency range and non overload specialty. Therefore, this type of long axis centrifugal pump can meet the design requirements, operate smoothly with high efficiency in both high flow period and drought period, decrease matching motor power and reduce one-time cost. Therefore, the results provide a certain reference for the optimum design of a long axis centrifugal pump. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:19
Main heading:Impellers
Controlled terms:Centrifugal pumps - Design - Efficiency - Errors - Flow measurement - Numerical analysis - Optimal systems - Pumps - Testing - Well pumps
Uncontrolled terms:Centrifugal pump impellers - Differ head - Long axis - Optimal design - Orthogonal design method - Orthogonal test - Orthogonal test method - Simulation technologies
Classification code:408 Structural Design - 423.2 Non Mechanical Properties of Building Materials: Test Methods - 601.2 Machine Components - 618.2 Pumps - 731 Automatic Control Principles and Applications - 913.1 Production Engineering - 921 Mathematics - 921.6 Numerical Methods - 943.2 Mechanical Variables Measurements - 961 Systems Science
DOI:10.3969/j.issn.1002-6819.2015.05.006
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 26>

Accession number:20151400700192
Title:Remote sensing inversion of saline soil salinity based on modified vegetation index in estuary area of Yellow River
Authors:Chen, Hongyan (1); Zhao, Gengxing (1); Chen, Jingchun (2); Wang, Ruiyan (1); Gao, Mingxiu (1)
Author affiliation:(1) National Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, College of Resources and Environment, Shandong Agricultural University, Taian, China; (2) Hydrological Bureau of Juye County, Juye, China
Corresponding author:Zhao, Gengxing
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:107-114
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Fast acquisition of the soil salt content, characteristics, and spatial distributing are the objective needs of saline soil management and utilization. This paper focused on the saline soil on the Yellow River Delta, and took Kenli County as an example. Based on the multi-spectral remote sensing image of Landsat 8 OLI, the traditional vegetation index (VI) was extended by adding the short-wave infrared band, and the modified vegetation index (MVI) was put forward. Then, based on the corresponding VI and MVI, using multivariate stepwise regression (MLR), a back propagation neural network (BPNN), and the support vector machine (SVM) method respectively, the remote sensing inversion models of soil salinity were built, validated, and compared. Finally, the spatial distribution of soil salinity was analyzed using the best model in the study area. The results indicated that the correlation between the vegetation indices and soil salinity was heightened and the multicollinearity between vegetation indices was greatly reduced by extending the traditional vegetation index. Extended normalized difference vegetation index(ENDVI) and extended ratio vegetation index (ERVI) which were added band 7 were selected as the modified vegetation index(MVI). Using MLR, a BPNN and the SVM method, the precision of the models based on the MVI was improved compared to the VI with the calibration coefficient of determination (R²) raised between 0.05 and 0.11, and the calibration root mean squares error (RMSE) reduced between 0.09 and 0.55, the validation R²raised between 0.04 and 0.10, the validation RMSE reduced between 0.13 and 0.73, and the validation relative prediction deviation (RPD) raised between 0.25 and 0.34. The models based on MVI obtained generally good performance with the validation RPD greater than 2.00. The main reasons improved the model precision were that the band 7 on Landsat 8 OLI had more information and the MVI including band 7 could more protrude the difference in vegetation coverage and production status. Comparing the three modeling methods, the SVM achieved the highest accuracy, the second was the BPNN, and the MLR analysis resulted in the lowest accuracy. With the calibration R²and RMSE of 0.75 and 3.48, the validation R², RMSE and RPD of 0.78, 3.02 and 2.56, the SVM model of soil salinity based on MVI was the best and obtained very high accuracy and reliability for remote sensing inversion of soil salinity content. The spatial distribution of soil salinity content in the study area was analyzed based on the best model. The statistical information of the inversed soil salinity was very close to the measured value of soil samples, the soil salinity content in the study area was very high generally, the area that belonged to severe saline soil and solonchak accounted for 77.91%, and the spatial distribution of soil salinization showed that the soil salinity content was gradually increased from the southwest agriculture region to the northeast coastal region, which was consistent with the field survey and geostatistical analysis. Therefore, the experiment indicated that the vegetation index was modified by introducing the band 7 based on Landsat 8 OLI, and the SVM model of soil salinity was built, which could obtain better inversion result of soil salinity spatial distribution. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:33
Main heading:Soil surveys
Controlled terms:Agronomy - Backpropagation - Calibration - Image reconstruction - Infrared radiation - Neural networks - Regression analysis - Remote sensing - Rivers - Salts  - Soils - Spatial distribution - Support vector machines - Vegetation
Uncontrolled terms:Back-propagation neural networks - Calibration coefficients - Inversion - Normalized difference vegetation index - Ratio vegetation indices - Short wave infrared bands - Vegetation index - Yellow River Estuary
Classification code:407.2 Waterways - 483.1 Soils and Soil Mechanics - 723 Computer Software, Data Handling and Applications - 723.4 Artificial Intelligence - 731.1 Control Systems - 741 Light, Optics and Optical Devices - 741.1 Light/Optics - 804.1 Organic Compounds - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.3 Agricultural Methods - 921 Mathematics - 922.2 Mathematical Statistics - 941 Acoustical and Optical Measuring Instruments - 942 Electric and Electronic Measuring Instruments - 943 Mechanical and Miscellaneous Measuring Instruments - 944 Moisture, Pressure and Temperature, and Radiation Measuring Instruments
DOI:10.3969/j.issn.1002-6819.2015.05.016
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 27>

Accession number:20151400700194
Title:Adaptability analysis on revised universal soil loss equation in small catchment of Three Gorges Reservoir Region
Authors:Ju, Zhansheng (1); Wen, Anbang (1); Yan, Dongchun (1); Shi, Zhonglin (1); Wang, Binyan (1)
Author affiliation:(1) Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences and Ministry of Water Resources, Chengdu, China; (2) University of Chinese Academy of Sciences, Beijing, China
Corresponding author:Wen, Anbang
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:121-131
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Soil erosion by water is a serious problem in southwestern China, particularly in the Three Gorges Reservoir Region (TGRR), which is one of the regions prone to desertification. Soil erosion in the TGRR not only affects soil quality, in terms of agricultural productivity, but also reduces the capacity of flood storage and the projected life span of the Three Gorges Reservoir. The revised universal soil loss equation (RUSLE) has been widely deployed to quantitatively assess soil erosion by water from a small catchment based on a grid cell basis. This study was conducted on the Huangchongzi small catchment in TGRR, to predict different periods' annual soil erosion modulus using the RUSLE model, and to analyze its adaptability with the help of a sediment budget approach. According to the study area data and the calculation methods for each factor of the Chinese soil loss equation applied in the first national water conservation survey, each factor value of RUSLE was determined. The results from the RUSLE model indicated that the annual soil erosion modulus for 1963-2000 (agricultural catchment) and 2001-2014 year (forested catchment) in the Huangchongzi small catchment was 2246.09 and 868.30 t /(km²&middot;a), respectively. The latter was obviously smaller than the former due to the implementation of the Grain-to-Green project, converting slope croplands into forest or grassland. The sediment yields for the 1963-2000 and the 2001-2014 years in the study catchment were 1228.71 and 322.71 t, respectively when¹³⁷Cs and²¹⁰Pb dating methods had been used as chronometers for sediment deposition in the pond. More importantly,²¹⁰Pb-derived dates corresponded well with the results from¹³⁷Cs geochronology for pond sediment cores, and this indicated that the dating result by²¹⁰Pb technology was correct and reliable. The annual sedimentation amount in the paddy fields was estimated to be 27.11t/a on the basis of the¹³⁷Cs tracer method. Therefore, the sediment deposition amount for the 1963-2000 and the 2001-2014 years in the paddy fields were 1003.07 and 352.43t, respectively. Based on the sediment yields and deposition amounts, sediment budgets of the 1963-2000 and the 2001-2014 years for the catchment had been constructed, respectively. The results from the sediment budget approach showed that the annual soil erosion modulus for the 1963-2000 and the 2001-2014 years were 942.48 and 811.47 t/(km²&middot;a), respectively. These calculations were directly compared with the RUSLE estimations in different periods since there was no gully and channel erosion in the study catchment. Results showed that the soil erosion modulus by sediment budget approach was reasonably consistent with that provided by RUSLE during the 2001-2014 years; this indicated that the adaptability of RUSLE was good in the forested catchment. However, the soil erosion modulus estimated by RUSLE for the study catchment was much higher than the soil erosion modulus obtained by the sediment budget approach during the 1963-2000 years and its relative error was as high as 138.31%. These findings highlighted that the adaptability of RUSLE was very poor in the agricultural catchment. Nevertheless, the soil erosion modulus for the 1963-2000 years estimated by the revised RUSLE in the study catchment was 1019.18 t/(km²&middot;a), and the error between the revised RUSLE soil erosion rates and that from the sediment budgeting approach decreased to 8.14%. This conclusion demonstrated that the method for correcting the LS factor value proposed by this study in the agricultural catchment was efficient and feasible. In brief, RUSLE with localization parameters can directly evaluate soil erosion in a forested catchment of the TGRR; on the contrary, its estimation error was very large in the agricultural catchment when RUSLE was directly utilized. It was necessarily to revise the LS factor value first and then to assess soil erosion in the agricultural catchment using the revised RUSLE in the TGRR. This study can provide beneficial references for the correct utilization of the soil erosion model and optimum utilization of the soil and water resources in the TGRR. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:45
Main heading:Soil conservation
Controlled terms:Agriculture - Budget control - Catchments - Cesium - Deposition - Digital storage - Erosion - Estimation - Forestry - Geochronology  - Geographic information systems - Lakes - Lead - Models - Productivity - Reservoirs (water) - Runoff - Sediment transport - Sediments - Soils  - Water conservation - Water resources
Uncontrolled terms:Agricultural catchments - Agricultural productivity - Chinese soil loss equations - Localization parameters - Revised universal soil loss equations - Soil erosion modeling - Three gorges reservoir - Three Gorges Reservoir region
Classification code:407 Maritime and Port Structures; Rivers and Other Waterways - 441.2 Reservoirs - 444 Water Resources - 444.1 Surface Water - 481.1 Geology - 483 Soil Mechanics and Foundations - 483.1 Soils and Soil Mechanics - 546.1 Lead and Alloys - 549.1 Alkali Metals - 722.1 Data Storage, Equipment and Techniques - 723.3 Database Systems - 813.1 Coating Techniques - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.0 Woodlands and Forestry - 902.1 Engineering Graphics - 911 Cost and Value Engineering; Industrial Economics - 913.1 Production Engineering - 921 Mathematics
DOI:10.3969/j.issn.1002-6819.2015.05.018
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 28>

Accession number:20151400700205
Title:Performance experiment and CFD simulation of heat exchange in solar greenhouse with active thermal storage back-wall
Authors:Zhang, Yong (1); Gao, Wenbo (1); Zou, Zhirong (1)
Author affiliation:(1) College of Horticulture, Northwest University of Agriculture &amp; Forestry, Yangling, China
Corresponding author:Zou, Zhirong
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:203-211
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Efficient utilization of solar energy is one of the important topics of structural optimization design of solar-greenhouse. And it is significant to the applied researches in this field and particularly to greenhouse energy conservation. Chinese solar greenhouse achieved high efficiency of energy expenditure in the practice. Solar greenhouse played a huge role in the agriculture production particularly in winter in northern China. However, solar greenhouse basically has two major problems. One problem is energy imbalance in the indoor greenhouse between daytime and nighttime. Solar greenhouse has to be ventilated due to the high indoor temperature in the daytime. And it has to be heated at night to protect vegetable from frost damage. According to statistical analysis, the losses to agricultural production brought by freezing injury are almost the sum losses by other stress. At the same time it also limits the efficient utilization of solar greenhouse. This paper introduces new types of solar-greenhouses. The innovation structure is the active energy-storage solar-greenhouse which can active storage heat during the daytime. Theoretical analysis was carried out on the indoor temperature and the regenerative properties of soil-air heat transfer of the active energy-storage solar-greenhouse in this paper. Comparing with the 9m-span normal solar-greenhouse with fixed back-wall, the active energy-storage solar-greenhouse has higher indoor temperature and temperature indicators have improved greatly. Under such experiment condition the active energy-storage solar-greenhouse is more efficient in utilization of solar energy and raising temperature. The indoor temperature in the greenhouse with active thermal storage technology has a great enhancement comparing with the normal type at clear and cloudy day. The mean indoor temperature increased by 1.8 to 2.8 in the active thermal-storage back wall solar-greenhouse within Nocturnal period (16:00-09:00) on Jan 15, 2014 (clear day). The average mean indoor temperature increased by 2.2. The mean indoor temperature increased by 1.6 to 4.2 in the active thermal-storage back wall solar-greenhouse within Nocturnal period (16:00-09:00) on Feb 12, 2014 (cloudy day). The average mean indoor temperature increased by 2.2. The average mean indoor temperature increased by 1.0 within Nocturnal period (16:00-09:00) on Feb 5, 2014 (snowy day). Synthesized every indexes, the solar-greenhouse with the active thermal-storage back wall may be the most economic structure; it can improve the thermal performance better than the solar-greenhouse with normal back-wall solar-greenhouse with the same height-span ratio. Comparing with normal type, the mean indoor temperature increases is 1.8 in the greenhouse with active thermal storage type at this experiment condition. This paper provides the theoretic foundation and experiment results on the efficient utilization of thermal storage and the improvement of greenhouse structure management. A detailed analysis is made for the ISO-surface of 20 of the active thermal-storage back wall in the paper. The results show that the effective range of the ventilation length varied from approximately 10 m to 15 m, while the air channel over 15m in the active thermal storage back-wall has little effect on energy storage performance. The optimum length of the air channel is 15m. The fit curve of the CFD simulation model is identical with the test curve. According to indoor daytime thermal analysis based on an indoor average temperature, this paper presents the influence coefficient of active daytime thermal storage technology and analyzes the significance and skill of solar energy utilization in the design of new solar-greenhouse structure. And it provides the theoretic foundation and experiment results on the efficient utilization of Solar Energy and the improvement of greenhouse structure management. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Greenhouses
Controlled terms:Agriculture - Computational fluid dynamics - Economics - Energy conservation - Energy efficiency - Energy storage - Energy utilization - Heat exchangers - Heat storage - Heat transfer  - Soil testing - Solar energy - Solar heating - Space heating - Structural design - Structural optimization - Structure (composition) - Thermoanalysis
Uncontrolled terms:Agricultural productions - Chinese solar greenhouse - Heat exchange - Mean indoor temperature - Structural optimization design - Thermal storage - Thermal storage technology - Walls
Classification code:408.1 Structural Design, General - 483.1 Soils and Soil Mechanics - 525.2 Energy Conservation - 525.3 Energy Utilization - 615.2 Solar Power - 616.1 Heat Exchange Equipment and Components - 641.2 Heat Transfer - 643.1 Space Heating - 702 Electric Batteries and Fuel Cells - 801 Chemistry - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.6 Farm Buildings and Other Structures - 921.5 Optimization Techniques - 921.6 Numerical Methods - 951 Materials Science - 971 Social Sciences
DOI:10.3969/j.issn.1002-6819.2015.05.029
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 29>

Accession number:20151400700191
Title:Evaluation of cultivated land irrigation guarantee capability based on remote sensing evapotranspiration data
Authors:Huang, Jianxi (1); Li, Li (1); Zhang, Chao (1); Yun, Wenju (2); Yang, Jianyu (1); Zhu, Dehai (1)
Author affiliation:(1) College of Information and Electrical Engineering, China Agriculture University, Beijing, China; (2) Key Laboratory for Agricultural Land Quality Monitoring and Control, Ministry of Land and Resources, Beijing, China
Corresponding author:Zhang, Chao
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:100-106
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The enhancement of cultivated land quality is an important measure to improve the production capability and ensure the food safety. At the construction course of cultivated land quality informatization, novel methods and techniques are promising to improve the current working pattern as well as raise the efficiency of cultivated land quality management. Irrigation guarantee capability is an important element of cultivated land quality monitoring, evaluation and construction. Evapotranspiration (ET) derived from remote sensing can be used for rapid monitoring of irrigation guarantee capability of cultivated land at the regional scale. In order to improve the acquisition efficiency of the regional cultivated land quality monitoring, a new evaluation method was proposed for irrigation capability evaluation of cultivated land based on Moderate Resolution Imaging Spectroradiometer (MODIS) ET products. First, in order to reduce the representative errors of meteorological data, the relationship between the monthly potential evapotranspiration (PET) parameter derived from MODIS evaporation products and the reference crop evapotranspiration (ET<inf>0</inf>) calculated from observed meteorological data with the Penman-Monteith (P-M) formula was analyzed. The continuous ET<inf>0</inf>in space was obtained from the regression model. And then, water requirements for crop were obtained by the map of crop type from the classification of Landsat TM data and space-continuous ET<inf>0</inf>. Furthermore, the annual water requirement was calculated according to the difference of the water requirement for crop and the rainfall which was effectively consumed by crop. Additionally, based on the regional water balance principle, the actual quantity of irrigation was obtained from the difference of actual evaporation derived from ET products of MODIS and effective rainfall. The evaluation index of irrigation guarantee capability is defined as the ratio of the annual irrigation requirement and the actual quantity of irrigation, and used for the monitoring and evaluation of cultivated land irrigation guarantee capability. Finally, application and analysis were conducted in Hengshui City, Hebei Province, China. The R²of the regression model between the PET and ET<inf>0</inf>from meteorological stations reached 0.89. And the calculated results of the evaluation index of irrigation guarantee capability from 2005 to 2012 accurately reflected temporal-spatial variations for the cultivated land irrigation capability. Meanwhile, the comprehensive evaluation of irrigation capability, which was from the supervised classification results based on actual survey, had a good agreement with the classification results of irrigation probability in the gradation on agriculture land quality which had been updated in 2012. The area with no grade difference was up to 37% of the total cells, 38% of the study area had one-grade difference, and the area with two-grade difference was 19% of the study area. The area with three-grade difference only accounted for 6%. The grade difference of more than 75% of the cultivated land was less than one grade. Errors were mainly concentrated in the cultivated land around the city, because the MOD16A2 product with 1-km resolution was inadequate to accurately represent the information of that complex planting structure of cultivated land, and this problem would be solved with the development and improvement of remote sensing earth observation systems with higher resolution. The evaluation index of irrigation capability proposed in this paper has the advantage of clear physical meaning and easy data accessing. The experiment results indicate that the method can meet the needs of the regional cultivated land quality monitoring and evaluation. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:17
Main heading:Quality control
Controlled terms:Crops - Errors - Evaporation - Evapotranspiration - Image reconstruction - Irrigation - Land use - Meteorology - Quality management - Radiometers  - Rain - Regression analysis - Remote sensing - Satellite imagery - Space optics
Uncontrolled terms:Cultivated land qualities - Earth observation systems - Moderate resolution imaging spectroradiometer - MODIS - Monitoring and evaluations - Potential evapotranspiration - Reference crop evapotranspirations - Supervised classification
Classification code:403 Urban and Regional Planning and Development - 443 Meteorology - 443.3 Precipitation - 731.1 Control Systems - 741 Light, Optics and Optical Devices - 741.1 Light/Optics - 802.3 Chemical Operations - 821.3 Agricultural Methods - 821.4 Agricultural Products - 913.3 Quality Assurance and Control - 922.2 Mathematical Statistics - 944.7 Radiation Measuring Instruments
DOI:10.3969/j.issn.1002-6819.2015.05.015
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 30>

Accession number:20151400700222
Title:Microfluidization pretreatment improving enzymatic hydrolysis of soy isolated protein and emulsifying properties of hydrolysates
Authors:Chen, Lin (1); Wu, Kegang (1); Chai, Xianghua (1); Yu, Lin (1)
Author affiliation:(1) Department of Food Science, College of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou, China
Corresponding author:Yu, Lin
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:331-338
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The current popularity of soy proteins, due to their low cost and high nutritional value, continues to drive soy research and commercial development of new food products. However, the poor emulsifying properties have limited the application of soy proteins in emulsion-based food products. Modification of soy proteins by enzymatic hydrolysis for improved functionalities is a well-accepted and safe method, but soy proteins are resistant to enzymatic hydrolysis due to their compact structures that protect many of the peptides bonds. Recently, it has been reported that microfluidization treatment can disrupt the quaternary and tertiary structure of globular proteins and break up protein aggregates, which may cause the exposure of more cleavage sites. However, limited information is available concerning the effects of microfluidization pretreatment on the enzymatic hydrolysis pattern of soy proteins or on the emulsifying properties of its hydrolysates. Hence, the objective of this work was to study the effects of combining microfluidization pretreatment and controlled enzymatic hydrolysis using Papain on the emulsifying properties of soy protein isolates (SPI). Microfluidizaiton pretreated SPI (MSPI) was prepared using a microfluidizer at a specific pressure level of 120 MPa. Papain was used as protease for the preparation of SPI hydrolysates (SPIH) and MSPI hydrolysates (MSPIH). Oil-in-water emulsions (20% v/v sunflower oil, 20 g/L protein sample, pH=7.0) were formed by SPIH and MSPIH with various DH (degree of hydrolysis). And the analysis of mean droplet sizes and microstructures of these emulsions showed that emulsions formed by control SPI and SPIH were unstable to bridging flocculation, suggesting their poor emulsifying capability. This findings may be explained by the fact that there were insufficient soluble protein with high surface activity existed in control SPI and SPIH. In contrast, some MSPIH (DH was 1.3%-1.7%) showed that the emulsifying capability and emulsions stabilization against bridging flocculation were markedly improved. Compared with control SPI and SPIH (0.6% DH), MSPIH (1.7% DH) was capable of producing a stable fine emulsion (d<inf>43</inf>&asymp;1.6 &mu;m) at a lower concentration (30 g/L), suggesting its better emulsifying capability. Composition of subunits, protein solubility (NSI), surface hydrophobicity (H<inf>0</inf>) and molecular weight distribution of SPIH and MSPIH have been measured in order to study the underpinning mechanisms of improving emulsifying capability for SPIH and MSPIH. The analysis of sodium dodecyl sulfate-polyacrylamide gel electrophoresis profiles of different hydrolysates showed that microfluidization pretreatment could significantly improve the enzymatic accessibility of subunits of &alpha;-7S and A-11S in SPI that were resistant to Papain hydrolysis. As a result, compared with SPIH, MSPIH showed a stronger increase in protein solubility and a more moderate change in surface hydrophobicity. Therefore, when DH was 1.3%-1.7%, MSPIH not only had greatly increased protein solubility (NSI was 51.3%-58.2%), but also retained sufficiently high surface hydrophobicity (H<inf>0</inf>was 1021.7-1614.2). These finding suggested that after microfluidization pretreatment, more soluble polypeptides with high surface activity were produced during Papain hydrolysis in MSPIH, which may be the main cause for the increase in their emulsifying capability. Moreover, compared with control SPI and SPIH (0.6% DH), MSPIH (1.7% DH) showed a smaller molecular weight distribution mainly around 11.3 kDa, and probably had a better flexibility of protein structure, which benefited for the adsorption and unfolding of protein molecule at the oil-water interface and for preventing the bridging flocculation of droplets. In summary, this study demonstrates that modified soy proteins can be an excellent emulsifying agent for food and other applications. It also demonstrates that combining microfluidization pretreatment and controlled enzymatic hydrolysis can be an effective way for the functionality modification of globular proteins. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:22
Main heading:Enzymatic hydrolysis
Controlled terms:Drops - Electrophoresis - Emulsification - Emulsions - Enzymes - Flocculation - Food products - Hydrolysis - Hydrophobicity - Molecular weight  - Molecular weight distribution - Oil shale - Oils and fats - Papain - Phase interfaces - Proteins - Sodium dodecyl sulfate - Sodium sulfate - Solubility - Sunflower oil
Uncontrolled terms:Bridging flocculation - Commercial development - Oil-in-water emulsions - Pre-Treatment - Sodium dodecyl sulfate-polyacrylamide gel electrophoresis - Soy protein isolates - Surface active - Surface hydrophobicity
Classification code:512.1 Petroleum Deposits - 801 Chemistry - 802.2 Chemical Reactions - 802.3 Chemical Operations - 803 Chemical Agents and Basic Industrial Chemicals - 804 Chemical Products Generally - 822.3 Food Products - 931.2 Physical Properties of Gases, Liquids and Solids
DOI:10.3969/j.issn.1002-6819.2015.05.046
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 31>

Accession number:20151400700200
Title:Localization method of picking point of apple target based on smoothing contour symmetry axis algorithm
Authors:Wang, Dandan (1); Xu, Yue (1); Song, Huaibo (1); He, Dongjian (1)
Author affiliation:(1) College of Mechanical and Electronic Engineering, Northwest A&amp;F University, Yangling, China
Corresponding author:Song, Huaibo
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:167-174
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The localization of picking points of fruits is one of the key problems for picking robots, and it is the first step of implementation of the picking task for picking robots. In view of a good symmetry of apples, and characteristics of shift, rotation invariance, and reaching the extreme values in symmetry axis direction which moment of inertia possesses, a new method based on a contour symmetry axis was proposed to locate the picking point of apples. In order to solve the problem of low localization accuracy which results from the rough edge of apples after segmentation, a method of smoothing contour algorithm was presented. The steps of the algorithm were as follow, first, the image was transformed from RGB color space into L*a*b color space, and then K-means color clustering algorithm was used to detect the apple target. The image was processed with amorphological opening operation with a 'disk'-shaped structural element of radius 5 before K-means clustering algorithm so as to ensure the accuracy of the K-means algorithm. Secondly, image pre-processing algorithms were carried out. Hole filling and area threshold algorithms were performed first to remove noise, and then a mathematical morphology operation with a 'disk'-shaped structural element of radius 10 was conducted to remove big spurs on the contour of apples. Thirdly, the contour of an apple was extracted by processing the pre-processed image with a morphological open operation. The calculate centroid of an apple and the distance between contour points and centroid were calculated, and then the distance curve could be obtained. After that, wavelet decomposition and Spline interpolation algorithms were used to smooth the distance curve, and then the smoothed distance curve was used to rebuild the contour of the apple. The procedures of rebuilding the contour of apples were as follow: 1) Coordinates transformation. In order to make an image coordinates system in accordance with common used coordinates system, coordinates transformation was needed. 2) Translation of the original point of coordinates to simply calculation. 3) Contour points-centroid angle normalization and calculation, which was of great significance to rebulit contour points. 4) Rebuilt contour points using the smoothed distance curve and normalized contour points-centroid angle. After these four steps, the contour of an apple could be obtained. Finally, the contour was used to extract the symmetry axis of an apple by using a moment of inertia algorithm. In order to verify the validity of this algorithm, a test was conducted by using the original algorithm and the presented algorithm with 20 single and unblocked apple images, respectively. The average error of the original algorithm was 20.678&deg;, and the average error of the presented algorithm was 4.542&deg;, 78.035% less than that of the original algorithm. Furthermore, the average run-time of the proposed algorithm was 7.5 ms, which was decreased by 25.839% when compared to the original algorithm (10.2 ms). The results showed that the presented algorithm could locate the picking point of an apple accurately and effectively. In conclusion, the presented algorithm is feasible for extracting the symmetry axis and locating the picking point of apples. However, this method was not applicable to blocked apple images, uneven illumination apple image, images containing apples with poor symmetry, and apples with part of a green region, for the entire contour of apple in these images cannot be obtained. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Clustering algorithms
Controlled terms:Algorithms - Color - Fruits - Image processing - Interpolation - Mathematical morphology - Robots - Wavelet decomposition
Uncontrolled terms:Coordinates transformation - Image coordinates system - K-Means clustering algorithm - Localization - Localization accuracy - Moment of inertia - Smoothing contour - Symmetry axis
Classification code:721 Computer Circuits and Logic Elements - 723 Computer Software, Data Handling and Applications - 731.5 Robotics - 741 Light, Optics and Optical Devices - 741.1 Light/Optics - 821.4 Agricultural Products - 921 Mathematics
DOI:10.3969/j.issn.1002-6819.2015.05.024
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 32>

Accession number:20151400700202
Title:Recognition of individual dairy cattle based on convolutional neural networks
Authors:Zhao, Kaixuan (1); He, Dongjian (1)
Author affiliation:(1) College of Mechanical and Electronic Engineering, Northwest A&amp;F University, Yangling, China
Corresponding author:He, Dongjian
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:181-187
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Video analysis has been widely used to perceive the behavior of animals for precise dairy farming, which is useful to increase the productivity and reduce the disease rate. Using computer vision technique to recognize the individual cow is feasible to improve the efficiency of the automatic milking and feeding system. Effective and accurate recognition of individual dairy cattle is the prerequisite and foundation to record and analyze the animal behavior automatically. As the classic method of individual recognition, the typical electronic identification device, referred to a radio frequency identification device (RFID), must be installed on the neck or another position of the animal. But the available distance is limited and the RFID tags suffer from some shortages such as the loss of tags, tempering, and animal welfare. Besides, it requires extra device and redundant process to recognize the individual cow in a video using RFID method. Therefore, it is necessary to develop an accurate and efficient system for recognizing individual cows in feeding environment utilizing image processing method. In this paper, individual dairy cattle were recognized using the body images based on convolutional neural networks with video analysis method. Side-view images with a resolution of 704 pixels &times;576 pixels were recorded when cows passed a narrow aisle to water trough. For target detecting, the frame difference method was implemented to obtain the outline and motion boundary of the cow. By dividing the target image into several same-width sections, the head and tail were removed from the image after checking the distribution of the target in the section. Because the ratio of the body's depth to cow's height was fixed at 0.6, the body area was located by drawing a box tangent to the back posture and then zoomed out 0.8 times of it to remove the external redundancy. For tracking the body image, template matching method was used to find the body area in the current frame by calculating the similarity against the target image in the previous frame. A convolutional neural network was built after analyzing the characteristics of the body images of cows. The network consisted of one input layer, two group of convolution-subsampling layers, and one output layer. The size of convolutional kernel was 5&times;5, and the subsampling size was 2&times;2. After testing different types of network architecture, the number of the feature maps in the first and third convolution layer were determined as 4 and 6, respectively, and the third convolution layers was partly connected to the second subsampling layer. The output layer was built up with 30 perceptrons, corresponding to the patterns of cows in the herd. After graying, resizing and normalizing, the body image of cow was transferred into a matrix sized 48&times;48 as the input of the network. 30 cows were captured 12 times for each, and 360 sets of videos were obtained in total, from which 60000 training frames, 21730 testing frames and 90 testing videos were selected randomly. In the tenth training epoch, the cost function was first less than 0.01. The result showed that 90.55% of the testing frames and 93.33% of the testing videos were recognized correctly, respectively. The testing data were captured from 7 a.m. to 6 p.m., so the network presented high robustness to the lightness diversity. The average elapsed time for recognizing one frame was lower than 0.01 s, and the total elapsed time for processing and recognizing one video was about 1 min, which showed a remarkable working efficiency and practicability. It suggested that the methods proposed here are feasible to recognize the individual dairy cattle. This study proves that the image processing technique has a great potential for recognition of animals. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Image processing
Controlled terms:Algorithms - Animals - Computer vision - Convolution - Cost functions - Identification (control systems) - Image analysis - Image matching - Network architecture - Neural networks  - Pixels - Processing - Radio frequency identification (RFID) - Target tracking - Template matching - Video signal processing
Uncontrolled terms:Convolutional neural network - Dairy cattles - Deep learning - Image technique - Video analysis
Classification code:461 Bioengineering and Biology - 461.1 Biomedical Engineering - 471 Marine Science and Oceanography - 716 Telecommunication; Radar, Radio and Television - 723 Computer Software, Data Handling and Applications - 731.1 Control Systems - 731.6 Robot Applications - 741 Light, Optics and Optical Devices - 741.2 Vision - 814 Leather and Tanning - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 822 Food Technology - 913.4 Manufacturing - 921.5 Optimization Techniques
DOI:10.3969/j.issn.1002-6819.2015.05.026
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 33>

Accession number:20151400700189
Title:Impact of rainfall and evapotranspiration on irrigation requirement of summer maize
Authors:Huang, Zhongdong (1); Qi, Xuebin (1); Fan, Xiangyang (1); Qiao, Dongmei (1); Li, Zhongyang (1); Liang, Zhijie (1)
Author affiliation:(1) Agricultural Water and Soil Environmental Field Science Research Station, Institute of Farmland Irrigation, Chinese Academy of Agricultural Sciences, Xinxiang, China
Corresponding author:Qi, Xuebin
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:85-92
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Irrigation requirement is important for agricultural water management and irrigation decision making, and it is strongly influenced by interannual fluctuations of rainfall and evapotranspiration. The summer maize is one of the main crops in the China North plain, and can be greatly affected by annual variation of rainfall and potential evapotranspiration during its growing season. For that reason, supplementary irrigation estimated based on the rainfall and potential evapotranspiration is necessary. In this study, the summer maize was selected as a research object in the southern area of the China North Plain, and the analytic relation between irrigation requirement and rainfall parameters associated with potential evapotranspiration was described on the basis of probability density function of soil moisture in order to investigate the influence of rainfall and potential evapotranspiration on irrigation requirement. The annual variations and statistical characteristics of rainfall, potential evapotranspiration and irrigation requirement were analyzed firstly, and then the Monte Carlo method was employed to investigate the long-term influences of rainfall parameters and potential evapotranspiration on irrigation requirement. The long series of rainfall parameters and potential evapotranspiration were generated by a pseudo-random number generator according to their probability density functions. The standard deviation and variation coefficient of irrigation requirement were adopted to assess the contribution of rainfall parameters and potential evapotranspiration to irrigation requirement fluctuations. The results showed that the annual variability of rainfall parameters was remarkable. Rainfall mean depth fluctuated between 4.958 and 25.003 mm with a variation coefficient of 0.326, and rainfall frequency fluctuated between 0.143 and 0.457 d^-1with a variation coefficient of 0.170. Rainfall mean depth conformed to a Logistic distribution with the expected value of 11.273 and the standard deviation of 2.022, and rainfall frequency conformed to the same distribution but with the expected value of 0.318 and the standard deviation of 0.029. Both rainfall mean depth and rainfall frequency presented an unmarked downward trend by Mann-Kendall tend test. While the annual fluctuation of potential evapotranspiration, which subjected to a LogNormal distribution with the expected value of 1.370 and the standard deviation 0.076, was smooth and steady, and there was a significant downward trend for it. Irrigation requirement fluctuated between 8.1 and 381.8 mm around the average value (133.1 mm) with a variation coefficient of 0.673, and the variation was significantly larger than rainfall parameters and potential evapotranspiration. Irrigation requirement conformed to a Gamma distribution with the shape parameter of 2.173 and the scale parameter of 61.271. There was an unremarkable upward trend for irrigation requirement. When taking no account of the annual fluctuations of rainfall parameters and potential evapotranspiration, the calculated average value of irrigation requirement was 114.3 mm. It indicated that it would underestimate the annual average value of the irrigation requirement without consideration the annual fluctuations of rainfall parameters and potential evapotranspiration. When only rainfall mean depth was considered as random variable, the standard deviation and variation coefficient of irrigation requirement were 63.6 mm and 0.485. When only rainfall frequency was considered as random variable, the standard deviation and variation coefficient were 41.9 mm and 0.354. When only potential evapotranspiration was considered as random variable, the standard deviation and variation coefficient were 28.4 mm and 0.245. While all of them were considered as random variables, the standard deviation and variation coefficient were 88.5 mm and 0.651. Rainfall mean depth contributed to the largest share of irrigation requirement fluctuations, followed by rainfall frequency and potential evapotranspiration. Annual fluctuations of irrigation requirement presented a larger uncertainty under the mutual effects of rainfall parameters and potential evapotranspiration. Consequently, it is necessary to assess the annual uncertainty of irrigation requirement, and to develop a reasonable strategy according to different rainfall and evapotranspiration conditions in order to reduce the negative impacts of climate fluctuations and guarantee food safety in China. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Rain
Controlled terms:Decision making - Evapotranspiration - Intelligent systems - Irrigation - Moisture - Monte Carlo methods - Number theory - Probability - Probability density function - Random number generation  - Random variables - Soil moisture - Statistics - Uncertainty analysis - Water management
Uncontrolled terms:Agricultural water management - Interannual fluctuations - Irrigation requirements - Log-normal distribution - Potential evapotranspiration - Pseudo random number generators - Statistical characteristics - Water demand
Classification code:443.1 Atmospheric Properties - 443.3 Precipitation - 444 Water Resources - 444.1 Surface Water - 446 Waterworks - 483.1 Soils and Soil Mechanics - 723.4 Artificial Intelligence - 821.3 Agricultural Methods - 912.2 Management - 921 Mathematics - 922.1 Probability Theory - 922.2 Mathematical Statistics
DOI:10.3969/j.issn.1002-6819.2015.05.013
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 34>

Accession number:20151400700179
Title:Analysis and validation for mechanical damage of apple by gripper in harvesting robot based on finite element method
Authors:Ji, Wei (1); Li, Junle (1); Yang, Jun (2); Ding, Shihong (1); Zhao, Dean (3)
Author affiliation:(1) School of Electrical and Information Engineering, Jiangsu University, Zhenjiang, China; (2) Key Laboratory of Measurement and Control of Complex Systems of Engineering, Ministry of Education, Southeast University, Nanjing, China; (3) Key Laboratory of Facility Agriculture Measurement and Control Technology and Equipment of Machinery Industry, Jiangsu University, Zhenjiang, China
Corresponding author:Ji, Wei
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:17-22
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to reduce the impact and crush damage of apple during the process of robot apple picking, the variation of stress on and inside the apple skin in the contact process of apple with different type's robot end-effectors was investigated mainly using the finite element analysis software ANSYS. Considering the mechanical characteristics difference of apple tissues, in this paper, apple component was simplified into skin, cortex and core, and each part contained the same material with same parameters such as elastic modulus, Poisson's ratio, stress intensity and density attributes, and then apple tissue was simplified to linear elastic material. Through the method combination of calculation and experiments, the mechanical parameters of apple skin, cortex and core, such as elastic modulus, breaking stress and poisson ratio, were obtained. And then the solid mechanics model constituted by skin, cortex and core of a single apple was established. On the basis above, taking the arithmetic mean of the elastic modulus for 3 parts of apple, the finite element model of apple was set up by ANSYS. Considering the stability of apple grasping and adopting the method to get the apple using cut knife to cut off the stem for picking robot, the load force by robot finger was set as 5, 20, 35 and 50 N respectively to simulate the contract process of apple with plane finger and arc-shaped finger. Based on the simulation above the Von Mises stress nephograms of apple skin, cortex and core were also obtained under different load force by different finger types. The Von Mises stress nephograms showed that when load force was 5, 20, 35 and 50 N respectively, the stress in skin caused by plane finger was 0.0258, 0.0898, 0.1559 and 0.3647 MPa, respectively, the stress in cortex was 0.0184, 0.0654, 0.1347 and 0.3245 MPa, respectively, the stress in core was 0.0017, 0.0058, 0.0136 and 0.0498 MPa, respectively. The stress caused by arc-shaped finger was relatively small. As for the deformation quantity, when the loading force on apple was 5, 20, 35 and 50 N respectively, the deformation quantity caused by arc-shaped finger was 0.0289, 0.104, 0.181, 0.564 mm respectively, and the deformation quantity caused by plane finger was 6.7%, 12.1%, 12.4% and 14.5% larger than that caused by arc-shaped finger respectively. The results showed that the stress of apple skin was the largest and stress of cortex takes the second place both for plane finger and arc-shaped finger. But the cortex was easier to get damaged as the result of its relatively small breaking stress. Meanwhile, under the precondition that the load force was same, compared to plane finger, the deformation and the stress of each part caused by arc-shaped finger was relatively small. That was to say, the probability to cause internal mechanical damage of the apple by arc-shaped finger was relatively small. The experiment for apple grasping damage of robot gripper validated the reliability of simulated results with relative error smaller than 10% between simulated and measured values. The results are helpful to make fast and accurate prediction along with evaluation of apple damage, and also provide valuble information for optimization of the injury-reduce devices for apple mechanization and automation harvesting robot as well as processing equipments. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:18
Main heading:Finite element method
Controlled terms:Deformation - Elastic moduli - End effectors - Fruits - Grippers - Harvesting - Loading - Loads (forces) - Machinery - Mechanical properties  - Poisson ratio - Robots - Stresses - Tissue
Uncontrolled terms:Configuration - Finite element analysis software - Harvesting robot - Linear elastic material - Mechanical characteristics - Mechanical damages - Mechanical parameters - Processing equipment
Classification code:408 Structural Design - 421 Strength of Building Materials; Mechanical Properties - 422 Strength of Building Materials; Test Equipment and Methods - 461.2 Biological Materials and Tissue Engineering - 601 Mechanical Design - 672 Naval Vessels - 731.5 Robotics - 821.3 Agricultural Methods - 821.4 Agricultural Products - 921.6 Numerical Methods - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2015.05.003
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 35>

Accession number:20151400700204
Title:Prediction of soil total nitrogen for rubber plantation at regional scale based on environmental variables and random forest approach
Authors:Guo, Pengtao (1); Li, Maofen (2); Luo, Wei (1); Lin, Qinghuo (1); Tang, Qunfeng (3); Liu, Zhiwei (3)
Author affiliation:(1) Rubber Research Institute, Chinese Academy of Tropical Agriculture Sciences, Danzhou, China; (2) Institute of Scientific and Technical Information, Chinese Academy of Tropical Agriculture Sciences, Danzhou, China; (3) Hainan Agricultural Reclamation Academy of Sciences, Haikou, China
Corresponding author:Luo, Wei
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:194-202
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Soil total nitrogen (STN) plays an important role in soil fertility and N cycle. Detailed information about the spatial distribution of STN is vital to effective management of soil fertility and better understanding of the process of N cycle. To date, however, few studies have been conducted to digitally map the spatial variation of STN for rubber (Hevea brasiliensis) plantation at the regional scale in Hainan Island, China. In this study, a relatively new method, random forest (RF) was proposed to predict and map the spatial pattern of STN for the rubber plantation. A total of 2511 topsoil (0-20 cm) samples were collected, and their STN contents were measured. Then these soil samples were randomly divided into calibration dataset (1757 soil samples) and validation dataset (754 soil samples). Fourteen environmental variables were also collected. They are parent materials, mean precipitation, mean temperature, mean normalized difference vegetation index, elevation, slope, aspect, horizontal curvature, profile curvature, relief, convergence index, relative position index, stream power index, and topographic wetness index. In this study, stepwise linear regression (SLR), generalized additive mixed model (GAMM), classification and regression tree (CART), and random forest (RF) were used to predict and map the spatial distribution of STN for the rubber plantation. In addition, GAMM and CART were also employed to uncover relationships between STN and environmental variables and further to identify the main factors influencing STN variation. The RF model was developed to predict spatial variability of STN on the basis of parent materials, mean precipitation, mean temperature, and mean normalized difference vegetation index. Performance of RF was compared with SLR, GAMM, and CART. Mean error (ME), mean absolute error (MAE), root mean squared error (RMSE), and correlation coefficient between measured STN and predicted STN were selected as comparison criteria. Results showed that RF performed much better than SLR, GAMM, and CART in predicting and mapping the spatial distribution of STN for the rubber plantation at regional scale in this study. The RF model had much higher correlation coefficient value and lower prediction errors (ME, MAE, and RMSE) than SLR, GAMM, and CART. Values of correlation coefficient, ME, MAE, and RMSE were 0.82,-0.003 g/kg, 0.088 g/kg, and 0.131 g/kg, 0.69, 0.003 g/kg, 0.121 g/kg, and 0.162 g/kg, 0.70,-0.004 g/kg, 0.120 g/kg, and 0.160 g/kg, and 0.68,-0.008 g/kg, 0.121 g/kg, 0.163 g/kg for RF, CART, GAMM, and SLR equation, respectively. Moreover, RF model yielded a more realistic spatial distribution of STN than SLR, GAMM, and CART equations. Finally, results of CART and GAMM showed that the relationships between STN and selected environmental variables (parent materials, mean precipitation, mean temperature, and mean normalized difference vegetation index) were hierarchical and non-linear in this study area. Analysis of variable importance indicated that parent materials and mean precipitation were the most important factors influencing spatial distribution of STN for rubber plantation at regional scale in this study. Overall, the good performance of RF model could be ascribed to its good capabilities of dealing with non-linear and hierarchical relationships between STN and environmental variables. These results suggested that RF is a promising approach in predicting spatial distribution of STN for rubber plantation at regional scale, and can be applied to predict other soil properties in regions with complex soil-environmental relationships. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:36
Main heading:Soil surveys
Controlled terms:Decision trees - Forecasting - Forestry - Mapping - Mean square error - Nitrogen - Precipitation (chemical) - Rubber - Rubber plantations - Soils  - Spatial distribution - Vegetation
Uncontrolled terms:Classification and regression tree - Digital soil mappings - Fertility - Normalized difference vegetation index - Regional scale - Rubber tree - Stepwise linear regression - Topographic wetness index
Classification code:483.1 Soils and Soil Mechanics - 802.3 Chemical Operations - 804 Chemical Products Generally - 818.1 Natural Rubber - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.0 Woodlands and Forestry - 902.1 Engineering Graphics - 921 Mathematics - 922 Statistical Methods - 922.2 Mathematical Statistics - 961 Systems Science
DOI:10.3969/j.issn.1002-6819.2015.05.028
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 36>

Accession number:20151400700215
Title:Product kinetics of Logistic model to simulate ethanol fermentation
Authors:Yue, Guojun (1); Liu, Wenxin (1); Liu, Jinsong (1); Yang, Xiaoguang (2); Ding, Qiankun (2); Dong, Hongxing (2); Song, Qilong (2); Guan, Xiaonan (2)
Author affiliation:(1) COFCO Biochemical Energy (Zhaodong) Co. Ltd., Zhaodong, China; (2) College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin, China
Corresponding author:Yang, Xiaoguang
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:280-286
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Ethanol plays an important role in the national economy, and is widely used in the raw materials of food, medicine, and the chemical industry. In recent years, with the challenge facing the world's energy security, more and more attention has been devoted to the conversion of biomass into fuel ethanol. Ethanol is considered to be a renewable and clean fuel, which can be an alternative to fossil fuels. So far, compared with other ethanol production methods, the fermentation method to produce ethanol has so many advantages, such as green environmental protection and low cost, that attracts lots of researchers' attention. There are many influence factors in the fermentation process, which make the fermentation process so complicated that it is hard to be controlled. The variation of the ethanol concentration with different fermentation times is directly related to the fermentation results. How to get higher ethanol concentration by a fermentation method has become the hot and difficult issue of the fermentation field. The research of ethanol fermentation kinetic is beneficial for understanding the fermentation process. It provides a theoretical basis for the amplification and optimization of fermentation industry. A bacteria growth dynamics model based on a Logistic equation can better describe the cell growth and inhibition; however, because the parameters and the integral constant of the model equation have no obvious biological significance, its application is limited. To establish a practical product kinetic model of ethanol fermentation, in this article, a reparameterized Logistic model was applied to correlate the ethanol concentration and time in the fermentation process, which was obtained by the analogy of the yeast growth. That is, an explicit function of ethanol concentration is given, which can combine biology and chemical engineering. As there was no yeast concentration in the model, the model was simplified so much and the parameters of it have an immediate physical interpretation that can be conveniently applied in industry. Through the research on glucose and corn starch as the raw material for ethanol fermentation, we studied the variation of ethanol concentration, total sugar concentration with time under the condition of different substrate quality, and the ratio of material to water. Then the experimental data were correlated by the reparameterized Logistic model in ethanol fermentation with glucose and corn starch. The model parameters and the consistency were good between the model and the experiments, the degree of fitting R², was greater than 0.97. The results showed that the model can be used to represent the kinetics behavior of ethanol concentration in fermentation, which has the potential to predict ethanol concentration in industrial fermentation. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:26
Main heading:Fermentation
Controlled terms:Chemical industry - Dynamics - Energy security - Ethanol - Ethanol fuels - Fuels - Glucose - Kinetics - Process control - Starch  - Yeast
Uncontrolled terms:Alternative to fossil fuels - Biological significance - Corn starch - Ethanol concentrations - Ethanol fermentation - Industrial fermentation - Logistic models - Physical interpretation
Classification code:522 Gas Fuels - 523 Liquid Fuels - 524 Solid Fuels - 525.6 Energy Policy - 731 Automatic Control Principles and Applications - 801.2 Biochemistry - 804.1 Organic Compounds - 805 Chemical Engineering, General - 805.1.1 Biochemical Engineering - 931 Classical Physics; Quantum Theory; Relativity - 931.1 Mechanics
DOI:10.3969/j.issn.1002-6819.2015.05.039
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 37>

Accession number:20151400700207
Title:Development of intelligent gateway for heterogeneous networks environment monitoring in greenhouse based on Android system
Authors:Chen, Meizhen (1); Wang, Jizhang (1); Li, Pingping (1); Zhou, Jinsheng (1); Xia, Defeng (1)
Author affiliation:(1) Key Laboratory of Modern Agricultural Equipment and Technology,, Ministry of Education, Jiangsu University, Zhenjiang, China; (2) College of Forest Resources and Environment, Nanjing Forestry University, Nanjing, China
Corresponding author:Wang, Jizhang
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:218-225
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The technologies of Internet of things have been widely applied in the agricultural environmental monitoring in recent years, while multiple transmission networks have been deployed to obtain environmental information. The gateway of internet of things was used for heterogeneous networks access and transmission of data protocol among the networks. In order to realize the unified management of heterogeneous networks that were used for greenhouse environment, an intelligent gateway with Exynos4412 as the core processor was developed, which has high speed operation capability and can be expanded for various communication module interfaces. Correspondingly, an application program worked in the gateway based on Android system was designed, which realized the management process of heterogeneous networks as following: Firstly, on the gateway display interface, user configured the information of the gateway communicating interface, data acquisition unit, and phase description of the sensors data stream. Secondly, the gateway application program established an information configuration file based on XML. Thirdly, after the application program was running again, according to the data stream description in XML configuration file, the gateway program matched the received data stream byte by byte segment in the data receiving tread, then positioned the sensor data in the data stream, parsed and converted the original value to the real value of the monitoring parameter. Fourthly, the data relation between keyword and value was composed to a map and was stored in the SQLite database. Lastly, the data access interface was provided for upper module such as real time data query module and historical data query module. The system was deployed in greenhouse and started running since December 18, 2014, to test three kinds of heterogeneous networks for Zigbee, RS-485 and Wi-Fi. The Zigbee network was used to collect air temperature, air humidity, light intensity, CO<inf>2</inf>concentration, soil moisture inside the greenhouse, and data was transmitted to a Zigbee aggregation unit that was linked to the gateway by Serial line. The RS-485 network was used to collect the meteorological information outside the greenhouse such as wind direction, air temperature, air humidity, wind speed, rainfall, UVI, light intensity, and data was transmitted to a 485/232 conversion module which linked to the gateway by Serial line. The Wi-Fi network was used to collect the greenhouse image data from the camera, and data was transmitted wirelessly to the Wi-Fi module in the gateway by using a wireless router. In the gateway application program, the heterogeneous networks channel properties and sensors data protocol was not fixed in the software code, but was configured by user on the interface, also the storage and display of monitoring parameters was synchronous with the configuration. Thus, the application program can save developing time when the system was deployed for similar greenhouse environment monitoring or the nodes in the networks were changed for different use. The running results for at least 14 days showed that the intelligent gateway had corresponded the analysis, storage and display of monitoring parameters to the configuration information. Various monitoring parameters of heterogeneous networks data had been stored, and environmental monitoring data can be updated accurately and history data record can be query accurately on the displaying interface of the gateway. The application model of the system was of good stability and can be further extended to more heterogeneous networks. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:22
Main heading:Gateways (computer networks)
Controlled terms:Android (operating system) - Application programs - Atmospheric temperature - Carbon dioxide - Computer hardware description languages - Data acquisition - Data communication systems - Digital storage - Environmental engineering - Environmental technology  - Greenhouses - Heterogeneous networks - Hypertext systems - Information management - Internet - Internet of things - Internet protocols - Monitoring - Networks (circuits) - Query processing  - Routers - Soil moisture - Soil testing - Wi-Fi - Wind - XML - Zigbee
Uncontrolled terms:Agricultural environmental monitoring - Android - Communicating interfaces - Data stream - Environmental information - Environmental Monitoring - Greenhouse environment - Meteorological information
Classification code:402.1 Industrial and Agricultural Buildings - 443.1 Atmospheric Properties - 454 Environmental Engineering - 483.1 Soils and Soil Mechanics - 703.1 Electric Networks - 722 Computer Systems and Equipment - 723 Computer Software, Data Handling and Applications - 804.2 Inorganic Compounds - 903.2 Information Dissemination - 941 Acoustical and Optical Measuring Instruments - 942 Electric and Electronic Measuring Instruments - 943 Mechanical and Miscellaneous Measuring Instruments - 944 Moisture, Pressure and Temperature, and Radiation Measuring Instruments
DOI:10.3969/j.issn.1002-6819.2015.05.031
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 38>

Accession number:20151400700184
Title:Influence of clearance flow on efficiency prediction of Francis turbines
Authors:Feng, Jianjun (1); Luo, Xingqi (1); Wu, Guangkuan (1); Zhu, Guojun (1)
Author affiliation:(1) Institute of Water Resources and Hydro-electric Engineering, Xi'an University of Technology, Xi'an, China
Corresponding author:Feng, Jianjun
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:53-58
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The disk friction loss of a Francis runner is crucial to the prediction of turbine efficiency, and the leakage flow through the gap near the runner band plays an important role to the flow structure of the draft tube, influencing the performance of a turbine. Therefore, investigation of runner leakage flow is very important for predicting accurately the turbine performance, especially turbine efficiency. In this paper, three-dimensional turbulent flow of a model Francis turbine has been simulated by using the CFD code ANSYS-CFX, with consideration of the runner leakage flow. Both steady and unsteady simulations have been conducted for different operating points of the turbine, and the turbulence was simulated with shear stress transportation (SST) turbulence model together with automatic near wall treatment. The disk friction loss of the runner was examined quantitatively, and CFD results were compared with those from the model test. The results show that the turbine efficiency predicted by CFD simulations with consideration of the runner disk friction loss is in very good agreement with the result from the model test for the operation points near the optimal point, and the one by CFD without the runner disk friction loss overestimates the turbine efficiency. For the operating points far away from the optimal point, the turbine efficiency predicted by CFD with consideration of runner disk loss is lower than the value from model test, due to flow separations or backflows existing in the flow field. The reduction in efficiency due to the runner disk friction loss becomes bigger with the increase of unit speed. The reduction in efficiency caused by the runner band surface is much higher than by the crown surface. In addition, the disk friction loss caused by the runner inner surface is basically equivalent to the one by the outer surface. Therefore, for a complex geometry, the outer disk friction loss can be estimated roughly by the inner one of the runner for simplification. Furthermore, at the same head, the leakage mass flow through the gap near the runner band is nearly constant, depending only on the pressure difference between the inlet and outlet of the gap. Moreover, the leakage flow through the gap near the runner band decreases the meridional velocity near the hub at the runner outlet at the optimal point, causing flow separation near the pier of the draft tube and producing extra hydraulic loss for the turbine. Based on the CFD results obtained from unsteady flow simulations for the optimal point, it is also found that the distributions of the inner and outer disk frictional loss in one period are influenced by the runner blade passing frequency, consisting of 13 peaks and valleys occurring at the same time. However, the phenomenon of rotor-stator interaction induced by the runner rotation has very limited influence on the disk friction loss. The relative peak to peak fluctuation is only 0.15% in one turbine period, denoting that the disk friction loss is nearly independent of the relative position between the runner and guide vanes. In addition, the same phenomenon has been found on the mass flow of the leakage near the runner band, with the relative peak to peak fluctuation of 0.03%. This research can provide useful reference for the prediction of disk friction loss of Francis turbine. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Computational fluid dynamics
Controlled terms:Efficiency - Flow of fluids - Flow separation - Forecasting - Francis turbines - Friction - Hydraulic motors - Hydraulic turbines - Inlet flow - Leakage (fluid)  - Mass transfer - Shear stress - Tribology - Tubes (components) - Turbines - Turbulence models - Wall function
Uncontrolled terms:Blade passing frequency - Clearance flow - Efficiency predictions - Friction loss - Meridional velocities - Mixed flows - Rotor-stator interactions - Three-dimensional turbulent flow
Classification code:421 Strength of Building Materials; Mechanical Properties - 452.3 Industrial Wastes - 616.1 Heat Exchange Equipment and Components - 617 Turbines and Steam Turbines - 617.1 Hydraulic Turbines - 631 Fluid Flow - 631.1 Fluid Flow, General - 632.2 Hydraulic Equipment and Machinery - 641.3 Mass Transfer - 913.1 Production Engineering - 921 Mathematics - 931 Classical Physics; Quantum Theory; Relativity - 931.1 Mechanics
DOI:10.3969/j.issn.1002-6819.2015.05.008
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 39>

Accession number:20151400700190
Title:Improvement and verification of Green-Ampt model for sand-layered soil
Authors:Fan, Yanwei (1); Zhao, Wenju (1); Wang, Yu (1); Bi, Guiquan (1)
Author affiliation:(1) College of Energy and Power Engineering, Lanzhou University of Technology, Lanzhou, China; (2) Key Laboratory of Mechanics on Disaster and Environment in Western China of Ministry of Education, Lanzhou University, Lanzhou, China
Corresponding author:Fan, Yanwei
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:93-99
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In the northwest of China, soil structure with sand interlayer is a common soil configuration. For soil structure with sand interlayer, infiltration rate will turn to steady infiltration rate when wetting front passes through the upper interface of sand layer. Normally, in the traditional Green-Ampt infiltration model, the water entry suction is difficult to determine. Furthermore, due to the hydraulic conductivity of wetting pattern is assumed to the saturated hydraulic conductivity of upper soil in the model, the error exists when calculating the steady infiltration rate of soil with sand interlayer. In order to compute the steady infiltration rate of the soil with sand interlayer accurately and conveniently, hydraulic conductivity coefficient, which was less than 1, was introduced to quantify the extent of water conductivity for upper layer soil on the basis of Green-Ampt infiltration model. More importantly, under the influence of various factors, the improved Green-Ampt infiltration model for soil with sand interlayer was set up, which included the undetermined parameters to the hydraulic conductivity coefficient and water entry suction. With the HYDRUS-1D software, the procedure of steady infiltration under various factors including soil texture, soil initial water content, pressure head, sand depth and sand thickness was simulated. At the same time, the law of infiltration and its influencing factors were analyzed according to the simulation results. The results showed that steady infiltration rate was mostly influenced by soil texture, pressure head and sand depth, but the steady infiltration rate of soil with sand interlayer was not affected by the soil initial water content and the thickness of sand interlayer. In view of the above, the steady infiltration rate could be acquired through simulation by changing sand depth while remaining pressure head, initial water content and sand thickness constant. Then the values of hydraulic conductivity coefficient and water entry suction were determined by fitting with the improved Green-Ampt infiltration model. The determination coefficient of fitting curve was larger than 0.99. In addition, the value of hydraulic conductivity coefficient changed in the range of 0.91 to 0.99. The average value of 0.95 was adopted in order to simplify the calculation. After that, the determined hydraulic conductivity coefficient was put into the improved Green-Ampt infiltration model. The improved Green-Ampt infiltration model was used further to match, with the purpose to determine the water entry suction. It was found that water entry suction was inversely proportional to the reciprocal of air entry value. Therefore, according the reciprocal of air entry value, which was one of the soil physical characteristic parameters, the calculation formula of water entry suction by estimation was put forward. In order to verify the reliability and universality of the improved model in this research, the water infiltration experiments of the soil with sand interlayer in Qinwangchuan area were conducted. The model was verified both by the experimental results and the available literature data. The improved model was proved to be better than the conventional calculation method for steady infiltration rate because the undetermined parameters were less, the solution for parameters was simpler, and the practicability was better. Simultaneously, the error was basically within 5%. In this paper, the developed model relied on the saturated hydraulic conductivity of upper soil and the reciprocal of air entry value of van Genuchten-Mualem model of sand layer soil. And the two parameters were the basic parameters of soil hydraulic properties, which could be obtained from the simple laboratory tests. Therefore, this model can provide valuble information for agricultural water management and engineering seepage controlling technique. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:20
Main heading:Infiltration
Controlled terms:Curve fitting - Hydraulic conductivity - Numerical analysis - Sand - Soil testing - Soils - Textures - Verification - Water management - Wetting
Uncontrolled terms:Agricultural water management - Green-ampt infiltration models - Green-Ampt model - Hydraulic conductivity coefficients - Layered soils - Saturated hydraulic conductivity - Steady infiltration rate - Van Genuchten-Mualem models
Classification code:444 Water Resources - 446 Waterworks - 483.1 Soils and Soil Mechanics - 632.1 Hydraulics - 723.1 Computer Programming - 921.6 Numerical Methods - 931.2 Physical Properties of Gases, Liquids and Solids - 933 Solid State Physics
DOI:10.3969/j.issn.1002-6819.2015.05.014
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 40>

Accession number:20151400700211
Title:Parameter optimization of fermented substrate from wolfberry shoots
Authors:Feng, Haiping (1); Yang, Zhigang (3); Yang, Dongyan (1); Qu, Jisong (1); Wang, Chunliang (1); Guo, Wenzhong (2)
Author affiliation:(1) Institute of Germplasm Resources, Ningxia Academy of Agriculture and Forestry Science, Yinchuan, China; (2) National Engineering Research Center for Intelligentized Equipment Technology in Agriculture, Beijing, China; (3) Ningxia Agriculture and Animal Husbandry, Longde, China
Corresponding author:Wang, Chunliang
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:252-260
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:This paper explored the optimal substrate of wolfberry shoots for fermentation process and parameters. The study used an orthogonal experimental design with wolfberry shoots as the main raw material, dried chicken manure, cake, and urea as a nitrogen source, cellulose degrading bacteria, and EM complex composite bacteria and BM complex composite bacteria for the inoculation of exogenous microorganism. The effect of carbon and nitrogen ratio, microbial agents, nitrogen type, and nitrogen ratio on the fermentation process of wolfberry shoots for substrate production were studied. The parameters included composting temperature, carbon, nitrogen, bulk density, porosity, water holding capacity, air filled porosity, germination index, and C/N ratio. The results showed that adjusting the carbon and nitrogen ratio of 30:1, crude cellulose degrading bacteria inoculation, adding chicken or cake nitrogen, organic nitrogen: Inorganic nitrogen is 3:1 pile faster and longer duration of high temperature (above 50, respectively, 12, 13, 12 and 12 d, more than 55, respectively reached 8, 9, 9 and 7d), accumulated a higher temperature, shortening the maturity time of the wolfberry shoots powder; carbon and nitrogen ratio, microbial agents, nitrogen type and nitrogen type had significant influence on total organic carbon and C/N value of a pile, carbon and nitrogen ratio, nitrogen type and nitrogen ratio had significant influence on total nitrogen and nitrate nitrogen, carbon and nitrogen ratio, microbial agents, carbon and nitrogen ratio, microbial agents, nitrogen type, and nitrogen ratio had no significant influence on ammonium nitrogen; Nitrogen type and nitrogen ratio of matrix on bulk density, total porosity, pore water retention, and aeration porosity had no significant influence, but the impact on the Chinese wolfberry shoots maturity matrix parameters were significant, carbon and nitrogen ratio, microbial agents, nitrogen type and nitrogen ratio of matrix effects on the seed germination index (GI) are important in this order: N ratio &gt; ratio &gt; microbial agents &gt; nitrogen type. Taken together, the optimal substrate of wolfberry shoots for fermentation process and parameters carbon and nitrogen ratio of 30: 1, inoculation crude fiber degrading bacteria inoculation, adding chicken or cake nitrogen, organic nitrogen: and inorganic nitrogen was 3:1. The research on how to change wolfberry shoots into a horticultural substrate through composting can not only solve the problem of an agricultural waste recycling point, but also supplement or replace non-renewable production of horticultural peat substrate, provide a source of raw materials, and reduce the cost of substrate cultivation, with some research value and practical significance. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Nitrogen
Controlled terms:Agricultural wastes - Animals - Bacteria - Carbon - Cellulose - Cultivation - Fermentation - Optimization - Organic carbon - Piles  - Porosity - Process control - Seed - Substrates - Urea - Waste treatment
Uncontrolled terms:Carbon and nitrogen ratios - Carbon matrix - Cellulose degrading bacteria - Horticultural substrate - Orthogonal experimental design - Parameter optimization - Water holding capacity - Wolfberry shoots
Classification code:408.2 Structural Members and Shapes - 452.4 Industrial Wastes Treatment and Disposal - 461 Bioengineering and Biology - 471 Marine Science and Oceanography - 731 Automatic Control Principles and Applications - 801 Chemistry - 801.2 Biochemistry - 804 Chemical Products Generally - 804.1 Organic Compounds - 814 Leather and Tanning - 815.1.1 Organic Polymers - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 822 Food Technology - 921.5 Optimization Techniques - 931.2 Physical Properties of Gases, Liquids and Solids
DOI:10.3969/j.issn.1002-6819.2015.05.035
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 41>

Accession number:20151400700212
Title:Investigation and analysis of heavy metal contents from livestock feed and manure in North China
Authors:Wang, Fei (1); Qiu, Ling (1); Shen, Yujun (3); Ge, Yihong (1); Hou, Yueqing (3)
Author affiliation:(1) Northwest A&amp;F University, Yangling, China; (2) Rural Energy &amp; Environment Agency, Ministry of Agriculture, Beijing, China; (3) Chinese Academy of Agricultural Engineering, Beijing, China
Corresponding author:Qiu, Ling
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:261-267
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:With the popularity of understanding of pollution-free agricultural products by the public, government pays much attention to the safe application of organic fertilizer during the agricultural production process. Manure is not only the main raw material of organic fertilizer, but also one of the important factors affecting the quality of agricultural products. Due to the intensive and large-scale of livestock farming rapid development, some heavy metals such as Cu, Zn, As, Cr, Pb are widely used in feed additives. The biological potency of these trace elements is low, and with the use of animal manure into the environment, brings potential environmental risks and hazards to human health. In order to strengthen the source control of heavy metal, and further form the heavy metal resistance control system for organic fertilizer of agricultural products, in this paper, the heavy metal content in livestock and poultry feed was sampled for investigation and analysis. The results showed that the mainly exceeded elements of heavy metal in the livestock were Cu, Zn. Heavy metals Pb, Cr, As followed, and Cd, Ni, Hg were not exceeded. The exceedance of these elements in pig manure and broile manure were the most serious for all kinds of animal manure, beef cattle manure and egg chicken manure followed, and the cow dung was not exceeded. The value of the exceeded rate of Cu, Zn for pig manure and broile manure were up to 100% and 91.67%, respectively. The mainly pollutants for broile were Cr, Cu, Zn, and the value of exceeded rate were 50%, 66.67%, and 50%, respectively, but the egg chicken manure only had Cu exceeded, exceeding the rate of 11.11%. Different livestock feed exceedances of heavy metals in pig feed and beef cattle feed werethe most serious, and broile feed and cow feed followed. According to the Ministry of Agriculture's 1224 announcement for the Cu, Zn standard, Cu and Zn in pig feed exceeded the rate of 66.67% and 80.00% respectively, and broile feed Zn exceeded 62.50%; According to the feed hygiene standards for Cr, Pb, heavy metals Cr and Pb in beef cattle exceeded 83.33% and 66.67%, Cr in cow feed exceeded 60%, Pb in egg chicken feed exceeded 53.85%, and Cd in different animal feeds were not exceeded. The content of heavy metals Cd, Cr, Cu, Zn in animal manure showed a significant positive correlation with livestock feed (P&lt;0.01), and the content of Pb in animal manure showed a significant correlation with livestock feed (P&lt;0.05). The research helps to grasp the North China heavy metal pollution status in feed-animal manure, revealing the problem for heavy metals exceeded in manure and organic fertilizer which should be controlled from the source. This research to further reduce heavy metal pollution in the region and to ensure the quality and safety of agricultural production has an important significance. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:19
Main heading:Copper
Controlled terms:Agricultural products - Agriculture - Animals - Beef - Biohazards - Cadmium - Chemical contamination - Fertilizers - Health hazards - Health risks  - Heavy metals - Lead - Manures - Meats - Metal analysis - Metals - Pollution - Trace elements - Zinc
Uncontrolled terms:Agricultural productions - Heavy metal pollution - Heavy metal resistance - Investigation and analysis - Livestock feed - North China - Pollution-Free Agricultural Products - Positive correlations
Classification code:454.2 Environmental Impact and Protection - 531 Metallurgy and Metallography - 544.1 Copper - 546.1 Lead and Alloys - 546.3 Zinc and Alloys - 549.3 Nonferrous Metals and Alloys excluding Alkali and Alkaline Earth Metals - 801 Chemistry - 804 Chemical Products Generally - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 822.3 Food Products - 914.1 Accidents and Accident Prevention - 914.3.1 Occupational Diseases
DOI:10.3969/j.issn.1002-6819.2015.05.036
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 42>

Accession number:20151400700177
Title:Study review and analysis of high performance intra-row weeding robot
Authors:Chen, Ziwen (1); Zhang, Chunlong (1); Li, Nan (1); Sun, Zhe (1); Li, Wei (1); Zhang, Bin (1)
Author affiliation:(1) College of Engineering, China Agricultural University, Beijing, China
Corresponding author:Li, Wei
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:1-8
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:To ensure food security and sustainable development of agriculture, it is critically important to develop organic agriculture and pollution-free agricultural products. Non-chemical weed control is important for organic agricultural production. Intra-row weeds are more difficult to be eliminated than inter-row weeds due to their proximity to the crop or seed line. Therefore, techniques for intra-row weed control remain to be one of the biggest challenges today. Efficient weeding robots can differentiate and remove inter-and intra-row weeds simultaneously, while identify and provide species information. The researches of intra-row weed control are more common in Europe because of their political interest and a push from the market. Nowadays, other countries, like the United States, Japan, Canada and China had carried out the researches in this area. This review describes the current state of the art of efficient weeding robots in detail to demonstrate the potential of the technology in the field. Several key technologies of weed control systems have been analyzed and compared. Three core technologies were summarized: guidance, detection and identification, and intra-row device. Row guidance which can use machine vision for crop row detection or GPS is an essential technology for weeding robot. Detection and identification which can identify and locate the crops in real time by three main approaches (computer vision, GPS and proximity sensor) is a critical technology. Furthermore, fusion of computer vision and GPS is seen today as the most promising strategy because advantages and disadvantages of absolute and relative referencing principles compensate each other. Intra-row device divided into rotation-type and swing type according to movements is a foundation of weed control. China is much later than the other developed countries in this area, but it has a booming development and grows rapidly. However, several technical problems exist as follows: 1) Recognition algorithm based on machine vision takes longer time, which makes the real-time of the system perform poorly; 2) Visual calibration method is cumbersome and complex under the non-structural condition; 3) The importance of intra-row weeding device development is ignored, weeding actuators directly affect weeding effect, the number and flow conditions of soil surrounding crops; 4) The hydraulic oil source is contaminated easily because tractor hydraulic oil is mainly used for lubrication; 5) Electric and pneumatic weeding robots are limited by poor battery life, and thus it is not available for field work; 6) The integrated performance of weed control system cannot meet the requirement of heavy load and efficient weeding in the field, and there still are some gaps between prototype and actual application; 7)There are less study on matching power system with speed of weeding robot that is the key to improve weeding precision and speed. According to the review, the further researches on weeding robots focusing on sensor fusion, efficient work, modular, miniaturization, high stability, and long life time have been proposed. With China gradually losing the advantage of cheap labor as well as sustained reduction of agricultural personnel, intra-row weeding robots are going to play an important role in agricultural production in China. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:48
Main heading:Weed control
Controlled terms:Agricultural machinery - Agricultural products - Agriculture - Computer vision - Control systems - Crops - Electric machine control - Electric power system control - Food supply - Hydraulic actuators  - Hydraulic fluids - Hydraulic machinery - Identification (control systems) - Oil field development - Oil shale - Oils and fats - Pneumatic actuators - Robots - Software prototyping
Uncontrolled terms:Agricultural productions - Critical technologies - Detection and identifications - Key technologies - Mechanical weeding - Pollution-Free Agricultural Products - Precision Agriculture - Recognition algorithm
Classification code:404.2 Civil Defense - 512.1 Petroleum Deposits - 512.1.2 Petroleum Deposits : Development Operations - 632.2 Hydraulic Equipment and Machinery - 723.1 Computer Programming - 723.5 Computer Applications - 731 Automatic Control Principles and Applications - 732.1 Control Equipment - 803 Chemical Agents and Basic Industrial Chemicals - 804.1 Organic Compounds - 821 Agricultural Equipment and Methods; Vegetation and Pest Control
DOI:10.3969/j.issn.1002-6819.2015.05.001
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 43>

Accession number:20151400700206
Title:Greenhouse environmental data collection based on improved Chauvenet's criterion
Authors:Wang, Lishu (1); Li, Yan (1); Liang, Qiuyan (1); Dong, Shoutian (1); Tang, Lijing (1)
Author affiliation:(1) Institute of Electrical and Information, Northeast Agricultural University, Harbin, China; (2) Mechanical Engineering School of Jia Musi University, Jia Musi, China
Corresponding author:Wang, Lishu
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:212-217
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:When agricultural greenhouse collects temperature and humidity data, cable network transmit data lead to wiring complexity and difficulties of moving nodes. Zigbee wireless sensor network transmit data can effectively solve the above problems. Zigbee has the virtue of ad hoc network, low power consumption, equipment layout flexibility, good stability and so on. The core components in greenhouse are consisted of terminal nodes, route nodes and coordinator node. Terminal nodes placed in greenhouse continuously send out request signals to join the network. All the terminal nodes receiving a response signal from the coordinator node can join the network. Terminal nodes collect temperature and humidity data and transmit these data to coordinator node. Coordinator node is the core of Zigbee and is placed in the geometric center of the greenhouse. It is responsible for the establishment of network and can communicate with computer in the control center. Coordinator node sends commands to terminal nodes and sends temperature and humidity data monitored by terminal nodes to the control center. Affected by unfavorable factors such as electromagnetic interference and transmission channel congestion, the collected data might include error data. This paper applied an improved Chauvenet's Criterion to eliminate the error data in greenhouse data collection system software. Traditional Chauvenet's Criterion eliminates one error data per cycle of operation, which leads to low convergence rate. Amount of error data cost a long time to process error data, which result in that data information cannot be obtained in a timely manner. Improved Chauvenet's Criterion is designed to solve this problem by applying the interquartile deviation method before data began cycle operation. According to the distribution of data, the data is sorted from smallest to largest so that improved Chauvenet's Criterion can find the upper quartile, median and lower quartile quickly. Quantile is used to determine a numerical interval. Large deviation error data will be eliminated. Improved Chauvenet's Criterion reduce the number of data participated in each cycle operation in order to save computer memory. Using the standard deviation to determine condition, each cycle of operation can eliminate multiple error data. This can improve data convergence rate, save processing time and meet requirements for real-time tracking data in greenhouse. Comparative analysis of the time complexity of traditional Chauvenet's Criterion and improved Chauvenet's Criterion, it fully proved that the improved Chauvenet's Criterion saves computing time. Greenhouse environment data collection system was tested in the Northeast Agricultural University Horticulture Station. The tomato plants were growing in order, greenhouse is convenient for arrangement of monitoring points. Monitoring nodes extracted a data per second. A group of 32 data was transmitted to the data processing software. From the system sending out commands to system display data, traditional Chauvenet's Criterion use 40s, improved Chauvenet's Criterion use 35s, and improved Chauvenet's Criterion saves 5s. It was found that data distribution area where data is processed by the improved Chauvenet's Criterion is more concentrated. And it is convenient for system and experts to make a decision and take the necessary control measures according to data distribution. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Data acquisition
Controlled terms:Ad hoc networks - Agriculture - Algorithms - Atmospheric humidity - Complex networks - Data handling - Electromagnetic pulse - Greenhouses - Humidity control - Low power electronics  - Sensor nodes - Telecommunication networks - Temperature - Wireless sensor networks - Zigbee
Uncontrolled terms:Agricultural greenhouse - Chauvenet's criterion - Data collection system - Data processing software - Greenhouse environment - Low-power consumption - Temperature and humidities - Transmission channels
Classification code:402 Buildings and Towers - 402.1 Industrial and Agricultural Buildings - 443.1 Atmospheric Properties - 641.1 Thermodynamics - 701 Electricity and Magnetism - 713 Electronic Circuits - 714 Electronic Components and Tubes - 715 Electronic Equipment, General Purpose and Industrial - 716 Telecommunication; Radar, Radio and Television - 717 Optical Communication - 718 Telephone Systems and Related Technologies; Line Communications - 722 Computer Systems and Equipment - 722.3 Data Communication, Equipment and Techniques - 723 Computer Software, Data Handling and Applications - 723.2 Data Processing and Image Processing - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.6 Farm Buildings and Other Structures - 921 Mathematics
DOI:10.3969/j.issn.1002-6819.2015.05.030
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 44>

Accession number:20151400700208
Title:Impact of biochar amendment on carbon emissions intensity in double rice field in South China
Authors:Qin, Xiaobo (1); Li, Yu'e (1); Wang, Hong (2); Li, Jianling (1); Wan, Yunfan (1); Li, Yong (3); Liao, Yulin (4); Fan, Meirong (5); Zhu, Jiangmin (6); Gao, Qingzhu (1); Liu, Shuo (1)
Author affiliation:(1) Key Laboratory for Agro-Environment, Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, China; (2) Semiarid Prairie Agricultural Research Centre, Agriculture and Agri-Food Canada, Swift Curren; SK, Canada; (3) Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, China; (4) Soils and Fertilizer Institute of Hunan Province, Changsha, China; (5) Changsha Environmental Protection College, Changsha, China; (6) Institute of Agriculture, Huizhou, China
Corresponding author:Li, Yu'e
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:226-234
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The resource utilization of organic materials in China cropland is a great challenge we are facing now. To study the ecological effects of biochar utilization, and explore the response of carbon emission intensity (GHGI) to biochar amendment for the long term in a double rice field in South China, two-year field measurements of greenhouse gases based on a static chamber-gas chromatography method were conducted. Six experimental treatments were set up, including 1) CK (famer traditional operation), 2) BC1 (biochar amendment at 5 t/hm²), 3) BC2 (biochar amendment at 10 t/hm²), 4) BC3 (biochar amendment at 20 t/hm²), 5) RS (raw rice straw residue return) and 6) RI (composted rice straw residue return). As a result, compared to CK, all of the biochar treatments inhibited the emission peaks of greenhouse gases from the double rice field. During the four rice growing seasons, the three biochar treatments decreased the 100 yr-scaled carbon dioxide emission equivalents by 27.53%, 58.65%, and 63.43%, respectively, compared with CK, RS, and RI. The biochar treatments significantly reduced methane emissions (P&lt;0.05) at an average reduction rate of 50.84%. Among the three biochar and two rice straw residue treatments, BC3 had the lowest methane emission potential (2.75 mg/(m²h)), while RS had the highest (10.05 mg/(m²&middot;h)). For the nitrous oxide emissions, the average value of the three biochar treatments was lower than CK but higher than the two rice straw residue return treatments (P&gt;0.05). Furthermore, there was no statistical significant yield increase effect found in the biochar treatments (P&gt;0.05), compared with CK, RS, and RI, as the four-season average rice yields of the three biochar treatments were increased by 3.21%, 5.11%, and 2.29%, respectively. A significant higher yield in BC3 was observed than that in RS (P&lt;0.05). Additionally, on a 100-year horizon, the GHGI of the three biochar treatments (average at 0.33 kg/kg) were 30.57%, 61.00%, and 64.82% lower than CK (0.48 kg/kg), RS (0.86 kg/kg), and RI (0.48 kg/kg), respectively. By the correlation matrix and principal component analysis, the biochar amendment controlled the distribution of rice yield, harvest index, soil organic matter, total carbon content, and chlorophyll content, while the rice straw residue return treatments dominated the distribution of the methane flux and GHGI. In summary, based on the present study, the application of the regression tree analysis offered a quantitative alternative to decision-making in analyzing the effects of biochar amendment on ecological environment. The results of this study indicated that the biochar amendment in soils has the potential to enhance soil carbon sequestration, increase rice yield, and mitigate the carbon emission intensity and the impact of climate change by optimization of the field managements and biochar return in an appropriate amount. This research could be used as a successful case study of scientific utilization of crop straw residue in China's agriculture. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:43
Main heading:Principal component analysis
Controlled terms:Carbon - Carbon dioxide - Climate change - Decision making - Ecology - Emission control - Forestry - Gas chromatography - Global warming - Greenhouse gases  - Methane - Nitrogen oxides - Soils
Uncontrolled terms:Bio chars - Carbon dioxide emissions - Carbon emission intensities - Ecological environments - Nitrous oxide emissions - Regression trees - Rice fields - Soil carbon sequestration
Classification code:451 Air Pollution - 454.3 Ecology and Ecosystems - 483.1 Soils and Soil Mechanics - 522 Gas Fuels - 801 Chemistry - 804 Chemical Products Generally - 821.0 Woodlands and Forestry - 912.2 Management - 922.2 Mathematical Statistics
DOI:10.3969/j.issn.1002-6819.2015.05.032
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 45>

Accession number:20151400700183
Title:Multi-objective optimization of low-specific-speed centrifugal pump
Authors:Yuan, Shouqi (1); Wang, Wenjie (1); Pei, Ji (1); Zhang, Jinfeng (1); Mao, Jieyun (1)
Author affiliation:(1) National Research Center of Pumps, Jiangsu University, Zhenjiang, China
Corresponding author:Yuan, Shouqi
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:46-52
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to improve the efficiency and head of a centrifugal pump with low-specifc-speed under design flow rate, an optimization approach of performance of the low-specific-speed centrifugal pump of IS50-32-160 was proposed by combining numerical simulation, design of experiment, approximation model and genetic algorithm. Three geometrical parameters containing blade outlet width, blade outlet angle, and blade warp angle were chosen as the design variables, and then 20 impellers were designed by Optimal Latin Hypercube Sampling method (OLHS). Commercial software ANSYS CFX 14.5 was used to conduct the steady numerical simulation to calculate the head and efficiency under design condition, which were chosen as the optimal objectives. Approximation model was built by using the Kriging model between the objectives and design variables, and had good prediction accuracy with R-square values of 0.9513 for efficiency and 0.9294 for head. Finally, the best combination of impeller parameters was obtained by solving the approximation model with genetic algorithm. To demonstrate the improvement of performance, the velocity distribution obtained by steady simulation and the pressure fluctuation intensity distributions calculated by unsteady simulation were compared. The results showed that the performance curves obtained by experiment and numerical simulation had a good agreement and the head deviation under design flow rate was 3.3%. The optimization improved the hydraulic efficiency by 3.2%, while, the head did not improve, but it still met the requirement of design. Compared with the parameters of original impeller, the blade outlet width of optimized impeller was smaller, the blade wrap angle was larger and the blade outlet angle did not change. The optimized impeller was redesigned with the optimal parameters, and the performance was calculated. It can be found that the predicted head and efficiency deviations were 3.3% and 0.056%, respectively. The internal velocity flow characteristics in the optimal impeller were improved and the area of the vortexes in the optimized impeller was smaller. The main frequency of fluctuation of efficiency is 145 Hz determined by blade passage frequency. The fluctuation values of efficiency of original and optimized pump under main frequency were 5.13 and 3.61, respectively. The pressure fluctuation intensity was the lowest at the leading edge of impeller and increase gradually along with the passage. The biggest pressure fluctuation intensity was distributed at the pressure side near to the trailing edge. The area of largest pressure fluctuation intensity was smaller in optimized impeller than in original one. The pressure fluctuation intensity was large from the tongue to the second section of volute, while the pressure fluctuation intensity was small at the seventh and eighth sections of volute. The pressure fluctuation intensity in the tongue reduced in the optimized pump. The pressure fluctuation of the monitor set in the tongue is periodic and there are 6 peaks in one period. The pressure fluctuation coefficient of the monitor in the optimized pump is 0.01, lower than that in the original one. The optimization decreased the fluctuation caused by impeller-volute interaction, thus enhancing the operation reliability of centrifugal pump. The optimization method presented can provide references to the optimization of high efficiency and non-over-load design of low-specific-speed centrifugal pump. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:21
Main heading:Multiobjective optimization
Controlled terms:Algorithms - Approximation algorithms - Centrifugal pumps - Computer simulation - Computer software - Design - Design of experiments - Efficiency - Flow rate - Genetic algorithms  - Impellers - Models - Numerical models - Pumps
Uncontrolled terms:Blade passage frequency - Impeller volute interactions - Latin hypercube sampling methods - Low specific speed centrifugal pump - Operation reliability - Optimization approach - Simulation , design of experiments - Unsteady simulations
Classification code:601.2 Machine Components - 618.2 Pumps - 631 Fluid Flow - 723 Computer Software, Data Handling and Applications - 723.5 Computer Applications - 901.3 Engineering Research - 902.1 Engineering Graphics - 913.1 Production Engineering - 921 Mathematics - 921.5 Optimization Techniques
DOI:10.3969/j.issn.1002-6819.2015.05.007
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 46>

Accession number:20151400700213
Title:Optimization of hollow insulation layer for flat plate solar collector based on micro heat pipe array
Authors:Deng, Yuechao (1); Zhao, Yaohua (1); Quan, Zhenhua (1); Liu, Zhongliang (2)
Author affiliation:(1) College of Architecture and Civil Engineering, Beijing University of Technology, Beijing, China; (2) College of Environmental and Energy Engineering, Beijing University of Technology, Beijing, China
Corresponding author:Deng, Yuechao
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:5
Issue date:March 1, 2015
Publication year:2015
Pages:268-274
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In this paper, a three-dimensional CFD numerical model of heat transfer and fluid flow was developed to simulate the thermal performance of the novel flat plate solar collector based on a micro heat pipe array to provide a theoretical basis for the structure improvement and optimization of the collector. The simulation of the novel collector with water flow included the CFD modeling of solar irradiation and the modes of mixed convection and radiation heat transfer between the absorber plate and glass cover, as well as the heat transfer in the circulating water inside the heat exchanger and conduction of the insulation. The fluid flow and heat transfer in the computational domain satisfied the continuity equation, the momentum equation, and the energy equation. The standard k-&Epsilon; two-equation turbulence model was used in this paper. In order to predict the direct illumination energy source that results from incident solar radiation and the radiation field inside the collector, the discrete ordinate radiation model with a solar ray-tracing model was used. A commercial computational fluid dynamics program (Fluent 6.3 CFD software) was used to solve the coupled fluid flow, heat transfer, and the radiation equation. The solver used is the segregated solver. Body Force Weighted was selected as the discretization method for pressure, and the SIMPLE algorithm was used to resolve the coupling between pressure and velocity. The discretization methods for the solving of momentum, energy, radiation, and turbulence were second order upwind. The thermal performance could be achieved by simulation results under different conditions. Then, the experimental and numerical results were compared to validate the prediction of the CFD model. The results showed that the numerical results of the thermal efficiency of the novel collector were in reasonable agreement with the experimental data. The validated CFD model was used to analyze the properties of the insulation layer. First, the effects of the thickness of solid insulation on the thermal performance of the collector were simulated using the numerical model. It indicated that when the thickness of solid insulation was 0.02, 0.03, 0.04, and 0.05 W/(m&middot;K) respectively, the optimum thickness of solid insulation was respectively 4.5, 5.0, 5.5, and 5.5 cm respectively. Then, in order to save cost, a new concept of the hollow insulation was presented on the insulation design of the collector, namely the combination of an air layer and a solid insulation layer. The simulations were conducted for the collector with a different size of the hollow insulation. The thermal efficiency comparison results of the collector for the hollow insulation and the solid insulation resulted in the following conclusions: 1) When the thickness of insulation was 4cm, the collector of hollow insulation with combination of 2 cm air layer and 2 cm solid insulation could get the same thermal performance as the solid insulation. And 25%-50% of the cost and weight of the insulation were saved. 2) When the thickness of insulation was 5cm, the collector of hollow insulation with combination of 2 cm air layer and 3 cm solid insulation could get the same thermal performance as the solid insulation. And nearly 40% of the cost and weight of the collector were saved. 3) When the thickness of insulation was 6cm, the collector of hollow insulation with combination of 3 cm air layer and 3 cm solid insulation could get the same thermal performance as the solid insulation. Nearly 50% of the cost and weight of the insulation were saved. Therefore, a reasonable design of the hollow insulation could obtain the same resemblance thermal insulation effect as the solid insulation collector, but the cost and weight could decrease from 25%-50%. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:15
Main heading:Thermal insulation
Controlled terms:Capillary flow - Collector efficiency - Computational fluid dynamics - Costs - Discrete event simulation - Flow of fluids - Flow of water - Heat convection - Heat exchangers - Heat pipes  - Heat transfer - Incident solar radiation - Insulation - Numerical models - Optimization - Plates (structural components) - Radiation - Ray tracing - Solar collectors - Solar energy  - Solar equipment - Solar radiation - Structural optimization - Sun - Turbulence models - Volume measurement
Uncontrolled terms:CFD numerical modeling - CFD simulations - Flat-plate solar collectors - Fluid flow and heat transfers - Instantaneous efficiencies - Micro heat pipe arrays - Thickness - Two-equation turbulence models
Classification code:408.2 Structural Members and Shapes - 413 Insulating Materials - 413.2 Heat Insulating Materials - 616.1 Heat Exchange Equipment and Components - 631.1 Fluid Flow, General - 631.1.1 Liquid Dynamics - 641.2 Heat Transfer - 657.1 Solar Energy and Phenomena - 657.2 Extraterrestrial Physics and Stellar Phenomena - 702.3 Solar Cells - 723.5 Computer Applications - 741.1 Light/Optics - 911 Cost and Value Engineering; Industrial Economics - 921 Mathematics - 921.5 Optimization Techniques - 943.2 Mechanical Variables Measurements
DOI:10.3969/j.issn.1002-6819.2015.05.037
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.