2013年8月第29卷第15期

2013年8月第29卷第15期

Accession number:20133516679239
Title:Evaluation of quality items for biodiesel made from three kinds of Chlorella vulgaris
Authors:Mei, Shuai (1); Zhao, Fengmin (1); Cao, Youfu (1); Liu, Wei (1); Su, Dan (1); Ding, Jinfeng (1); Li, Shujun (1)
Author affiliation:(1) Chinese Academy of Agricultural Mechanization Sciences, Beijing 100083, China
Corresponding author:Li, S.(lisj@caams.org.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:15
Issue date:August 1, 2013
Publication year:2013
Pages:229-235
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:In order to evaluate the quality items of microalgae biodiesel which has the potential to be exploited, this paper evaluated three kinds of Chlorella vulgaris biodiesel, providing a theoretical foundation for choosing an appropriate biodiesel Chlorella vulgaris species to produce biodiesel. Compared to petro-diesel, biodiesel has many advantages: higher biodegradability, lower sulphur content, lower carbon dioxide emission, no aromatic hydrocarbon, and lower flash point which makes the usage, transportation, management, and storage much safer. As a source of raw material for biodiesel production, oil productive Chlorella vulgaris commands high attention because of many strengths such as taking up less cultivated area, high growth rate, high oil-production efficiency, and renewability. The direct determination of biodiesel quality items is time wasting and costly, and for not yet industrialized microalgae cultivation, it is hard to acquire sufficient quantities of microalgae biodiesel. Through precursors'mathematical model between biodiesel FAME(fatty acid methyl ester) carton chain structure and Vis(viscosity), IV(iodine value), CN(cetane number), CFPP(cold filter plugging point), compared to the biodiesel standards of America, EU, Germany and China of Vis, IV, CN, CFPP, the Chlorella vulgaris biodiesel quality items can be indirectly forecasted. This paper through analysis of the oil content and the constituting of FAME which is made from oils in three kinds of oil productive Chlorella vulgaris cells, makes use of the established mathematical model between FAME carbon chain structure and biodiesel quality items, by reference to biodiesel standards of America, EU, Germany and China, and assesses the biodiesel quality items concluding Vis, IV, CN and CFPP of Chlorella vulgaris F-5,F-1067,F-31biodiesel. The results show that: the oil contents of Chlorella vulgaris F-5, F-1067, F-31are 15.30%, 13.13%, and 11.12%. The Vis of F-5 biodiesel is 8.3, which can meet the standards of America and China, but can't meet the standards of the EU and Germany, The IV, CN, CFPP of F-5 biodiesel are 77, 56, -3°C which can all meet the standards of America, the EU, Germany, and China; The Vis and CFPP of F-1067 biodiesel are 9.2and 9°C which can't meet the standards of America, the EU, Germany and China, The IV and CN of F-1067 biodiesel are 77 and 56 which can all meet the standards of America, the EU, Germany and China; The Vis of F-31biodiesel are 11.8 which can't meet the standards of America, the EU, Germany, and China, The IV and CFPP of F-31biodiesel are 112and -9°C which can meet the standards of America, EU, Germany, and China, the CN of F-31biodiesel is 47 whih can meet meet the standard of America, but can't meet the standards of the EU, Germany and China. So F-5 had the highest oil content, more than that, its comprehensive performance in Vis, IV, CN, CFPP was better than the other two, and it is the best fit to produce biodiesel in the three oil-productive Chlorella vulgaris. In addition, the method which this article used to evaluate the quality items for biodiesel made from three Chlorella vulgaris is quick, time-saving, economical, and convenient. It also supplies a method for a large number of species of microalgae screening as to whether they have potential for microalgae biodiesel production or not. Although the microalgae has great potential to produce biodiesel, at the present, the usage of microalgae to produce biodiesel still has a long way to go, because of its high cultivation cost, harvest cost, drying cost, and oil-extract cost. More effort needs to be exerted to do more research about it.
Number of references:36
Main heading:Fuel storage
Controlled terms:Algae - Biodegradation - Biodiesel - Carbon dioxide - Chains - Costs - Esterification - Esters - Fatty acids - Global warming - Mathematical models - Microorganisms - Quality control - Standards
Uncontrolled terms:Carbon dioxide emissions - Chain structure - Chlorella vulgaris - Cold filter plugging point - Comprehensive performance - Fatty acid methyl ester - Microalgae cultivation - Theoretical foundations
Classification code:921 Mathematics - 913.3 Quality Assurance and Control - 911 Cost and Value Engineering; Industrial Economics - 902.2 Codes and Standards - 804.2 Inorganic Compounds - 804.1 Organic Compounds - 802.2 Chemical Reactions - 801.2 Biochemistry - 602.1 Mechanical Drives - 523 Liquid Fuels - 461.9 Biology - 461.2 Biological Materials and Tissue Engineering - 451 Air Pollution
DOI:10.3969/j.issn.1002-6819.2013.15.028
Database:Compendex
Compilation and indexing terms, Copyright 2013 Elsevier Inc.

Accession number:20133516679227
Title:Appropriate nitrogen fertilizer strengthens growth and antioxidative ability of Festuca arundinacea under salt stress
Authors:Liu, Airong (1); Zhang, Yuanbing (2); Wang, Jianfei (2); Jiao, Min (1); Liu, Xiaomin (1)
Author affiliation:(1) Life Science College, Anhui Science and Technology University, Fengyang 233100, China; (2) Urban Construction and Environment College, Anhui Science and Technology University, Fengyang 233100, China
Corresponding author:Liu, A.(liuairong842@sohu.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:15
Issue date:August 1, 2013
Publication year:2013
Pages:126-135
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:In order to fertilize properly for F. arundinacea cultivated in the soil salinity areas, an experiment was conducted to investigate the effect of NH<inf>4</inf>NO<inf>3</inf> on growth and antioxidative ability of F. arundinaceawas under NaCl stress. F. arundinacea plants cultured with Hoagland nutrient solution (excluding nitrate nutration) in pots was treated with nine cross combinations of different NaCl concentrations at 0, 70, and 140 mmol/L, and three nitrate nitrogen levels at 0.01, 0.6, 1.2g/L (the nine treatments were 0 0.01, 70 0.01, 140 0.01, 0 0.6,70 0.6, 140 0.6, 0 1.2, 70 1.2, 140 1.2) for 25 days, and then the fresh weight, dry weight, water content, root dehydrogenase activity, nitrate reductase activity, NO<inf>3</inf>- content, membrane permeability, and MDA content were determined, and SOD, CAT isoenzyme activity and protein expression were also studied by polyacrylamide gel electrophoresis (PAGE) or SDS-PAGE. The results show that, compared with the same level of NH<inf>4</inf>NO<inf>3</inf>, the fresh weight, dry weight, and water content of F. arundinacea under salt stress were lower than those of F. arundinacea without salt stress, while the changes of root dehydrogenase activity, nitrate reductase activity, NO<inf>3</inf>- content, membrane permeability, and MDA content were in the opposite. PAGE or SDS-PAGE showed that SOD isoenzyme activities increase as CAT isoenzyme activities or protein expression changed. Under NaCl stress of the same concentration, when NH<inf>4</inf>NO<inf>3</inf> concentration increased, the fresh weight, dry weight, water content, and SOD isozymes activity also showed an ascendant trend, but NO<inf>3</inf>- content, membrane permeability, and MDA content decreased. Compared with NH<inf>4</inf>NO<inf>3</inf> level 0.01g/L, NH<inf>4</inf>NO<inf>3</inf> 0.6 g/L made root dehydrogenase activity, nitrate reductase activity, CAT isoenzyme activity, and protein expression amount increase markedly; and compared with NH<inf>4</inf>NO<inf>3</inf> level 0.6 g/L, NH<inf>4</inf>NO<inf>3</inf> 1.2g/L not only made the increment rate depression of root dehydrogenase activity, nitrate reductase activity, but also made CAT isoenzyme activity and protein expression amount have little change. Therefore, under the same concentration of NaCl stress, compared with NH<inf>4</inf>NO<inf>3</inf> 0.01g/L leavel, NH<inf>4</inf>NO<inf>3</inf> 0.6 g/L treatment strengthened the absorption ability on water and inorganic ion of root and the ability of reduction NO<inf>3</inf>-, and so improved the nitrogen nutrition of F. arundinacea. NH<inf>4</inf>NO<inf>3</inf> 0.6 g/L treatment also raised the ability of antioxidation, especially it markedly raised the ability of scanvaging H<inf>2</inf>O<inf>2</inf>, and so reduced membrane lipid peroxidation and endocyte exosmosis. Moreover, NH<inf>4</inf>NO<inf>3</inf> 0.6 g/L treatment intensified the protein expression amount. All the changes contributed to the improved ability of the salt resistance of F. arundinacea. Under the same concentration of NaCl stress, compared with NH<inf>4</inf>NO<inf>3</inf> 0.6 g/L level, NH<inf>4</inf>NO<inf>3</inf> 1.2g/L raised the ability of reduction NO<inf>3</inf>-; NH<inf>4</inf>NO<inf>3</inf> 1.2g/L also improved the scanvaging superoxide anion, and so reduced membrane lipid peroxidation and endocyte exosmosis; while the ability of root absorption on water and inorganic ion, scanvaging H<inf>2</inf>O<inf>2</inf>, protein express were enhanced insignificantly. These changes made mitigative effect of osmotic stress and inhibition on growth decended, and which may lead to NH<inf>4</inf>NO<inf>3</inf> accumulation in the rhizosphere environment, even probable soil secondary salinization if it was serious. This study provided reference for the reasonable application of NH<inf>4</inf>NO<inf>3</inf> to F. arundinacea planted in saline soil.
Number of references:36
Main heading:Reduction
Controlled terms:Antioxidants - Electrophoresis - Ions - Isoenzymes - Lipids - Nitrates - Nitrogen fertilizers - Oxygen - Proteins - Salts - Soils - Stresses - Water absorption
Uncontrolled terms:Anti-oxidative enzymes - F. arundinacea - Isozyme - NH<inf>4</inf>NO<inf>3</inf> - Root dehydrogenase
Classification code:421 Strength of Building Materials; Mechanical Properties - 483.1 Soils and Soil Mechanics - 801 Chemistry - 802.2 Chemical Reactions - 802.3 Chemical Operations - 804 Chemical Products Generally
DOI:10.3969/j.issn.1002-6819.2013.15.016
Database:Compendex
Compilation and indexing terms, Copyright 2013 Elsevier Inc.

Accession number:20133516679228
Title:Effects of low-energy N ion beam irradiation on photosynthetic and transpiration in rice under enhanced UV-B radiation
Authors:Li, Linyu (1); Huang, Qunce (1); Zhang, Shuyin (1); Zhao, Shuaipeng (1)
Author affiliation:(1) Henan Provincial Key Laboratory of Ion Beam Bio-engineering, Zhengzhou University, Zhengzhou 450052, China
Corresponding author:Huang, Q.(quncehuang@sohu.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:15
Issue date:August 1, 2013
Publication year:2013
Pages:136-144
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:With the rapid economic development occurring since the 20th century, human activities have exacerbated the deterioration of the environment, and one of the most prominent environmental problems is the global reduction of the stratospheric ozone layer that results in increasing levels of mid-ultraviolet (UV-B, 280-320 nm) radiation on the earth's surface. The effect of enhanced UV-B radiation on higher plants has been studied intensively. Many studies showed that enhanced UV-B radiation could damage the photosynthetic system by destroying the photosynthetic organs, degrading the photosynthetic pigments, restraining the process of photosynthetic electron transportation, reducing the CO<inf>2</inf> assimilation rate, and so on. Numerous scholars have even reported some ways to moderate the damage on plants caused by enhanced UV-B radiation such as nitrogen supply, doubled CO<inf>2</inf> supply, He-Ne laser radiation, NaHSO<inf>3</inf> spray, heavy metals addition, and so on. All of ways above had moderated the damage caused by enhanced UV-B radiation, while more ways should be found and applied in this field. Low-energy N ion implantation has been widely used in the mutation breeding of plant and microorganism due to its higher mutation frequency and wide mutation spectrum since the early 1980s. There are some reports showing that appropriate doses of low-energy N ion beam treatment could inspire the anti-oxidative enzyme system and change the physicochemical characteristics in plant cells on some level, which could regulate its defense system to deal with the outside stress. However, there was no report about the interactions between enhanced UV-B radiation and low-energy N ion beam radiation on rice. The effects of low-energy N ion beam irradiation on diurnal variations of photosynthesis and photosynthetic pigment contents in rice under enhanced UV-B radiation were investigated in the study. The experiment materials were pre-treated by three different doses of low-energy N ion beam that was conducted in Henan provincial at a key laboratory of ion beam bio-engineering, Zhengzhou university, China. Then the test materials were planted in an experimental field and uniformly managed routinely. One month later, the rice seedlings were implanted into the planting boxes provided by the laboratory. After turning green, the seedlings were treated with UV-B radiation for two months (from 8:00 to 17:00 per day) except for rainy or cloudy days. The dose of enhanced UV-B radiation was 16.46 kJ/m2 &middot d (a 20% difference in ambient UV-B, Zhengzhou, China) which was detected by an ultraviolet irradiation detector and normalized at 297 nm to obtain effective radiation. Two months later, the photosynthetic parameters (Pn,Tr,Gs,Ci) were determined with a portable photosynthesis system (CB-1102, Beijing Yaxin Liyi Science and Technology Co., Ltd. China) every two hours from 7:00 a.m. to 17:00 p.m. on a cloudless day, and the photosynthetic pigment content was determined too. The results were as follows: the net photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs),intercellular CO<inf>2</inf> concentration (Ci), and the content of chlorophyll a (Chla), chlorophyll b (Chlb) were decreased while the efficiency of the water application (WUE), the content of carotenoids (Car) and the Chla/b were enhanced by UV-B stress. The combined treatment of enhanced UV-B radiation and low-energy N ion beam radiation (3.0 × 1017 N /cm2) increased the photosynthetic parameters (Pn, Tr, Gs, Ci) and the photosynthetic pigment content. It was suggested that the appropriate dose of low-energy N ion beam treatment (3.0 × 1017 N /cm2 in this study) may alleviate the damage caused by the enhanced UV-B radiation on rice. In addition, the test results provided a valuable reference for exploring the combined effect of ion beam biotechnology and various mutagenic sources in the physiological characteristics of rice deeply.
Number of references:29
Main heading:Radiation effects
Controlled terms:Carbon dioxide - Chlorophyll - Heat radiation - Heavy metals - Ion beams - Ion implantation - Irradiation - Ozone layer - Photosynthesis - Pigments - Seed - Transpiration
Uncontrolled terms:Photosynthetic parameters - Photosynthetic pigment contents - Physicochemical characteristics - Physiological characteristics - Rice - Stratospheric ozone layers - Ultraviolet irradiations - UVB radiation
Classification code:821.4 Agricultural Products - 804 Chemical Products Generally - 803 Chemical Agents and Basic Industrial Chemicals - 744 Lasers - 932.1 High Energy Physics - 741.1 Light/Optics - 711 Electromagnetic Waves - 641.2 Heat Transfer - 531 Metallurgy and Metallography - 711.1 Electromagnetic Waves in Different Media
DOI:10.3969/j.issn.1002-6819.2013.15.017
Database:Compendex
Compilation and indexing terms, Copyright 2013 Elsevier Inc.

Accession number:20133516679238
Title:Crystal precipitation law of biodiesel based on thermodynamic phase equilibrium
Authors:Mei, Deqing (1); Tan, Wenbing (1); Yuan, Yinnan (2)
Author affiliation:(1) School of Automobile and Traffic Engineering, Jiangsu University, Zhenjiang 212013, China; (2) School of Mechanical Engineering, Nantong University, Nantong 226019, China
Corresponding author:Mei, D.(meideqing@ujs.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:15
Issue date:August 1, 2013
Publication year:2013
Pages:223-228
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:Biodiesel, as a renewable alternative fuel with the virtue of clean burning, can be directly used in a diesel engine without any mechanic modification. However, biodiesel is easily crystallized at a low temperature, which limits the application of engines fueled with biodiesel, especially in severe cold circumstances. Biodiesel is a mixture solution, and mainly contains of saturated and unsaturated fatty acid methyl esters. According to thermodynamics, the process of wax precipitation is a thermodynamic equilibrium from liquid phase to solid phase. The equilibrium relationship between the solid phase and the liquid phase doesn't keep constant. As long as one factor of the system changes, the phase diagram will follow changing. Two different kinds of models have been built to depict the crystal precipitation. Model 1, which is called ideal solution model, looks at liquid composition as the ideal solution and solid phase composition as not mutually soluble. Model 2is called a regular solution model based on activity coefficient model and the regular solution theory. The wax crystal precipitation temperature can be calculated by both models respectively. The quantity of paraffin wax and the composition of wax at the given temperature can also be worked out by Model 2. The accuracy of both models in calculating the wax precipitating temperature is good, and the deviation is within 4 K. With the increasing content of saturated fatty acid methyl esters (SFAME), the wax crystallized more easily, and the quantity of paraffin wax were proportional to the total amount of saturated fatty acid esters. By comparing and analyzing the characteristic parameters of the intermediate process during the solid-liquid equilibrium of one biodiesel solution at different temperatures, such as the compositions of liquid or solid phase and the solid-liquid equilibrium constants, it was found that the solid-liquid equilibrium constant is a crucial factor to indicate the precipitation ability of a substance in a biodiesel solution. At a given temperature, the solid-liquid equilibrium constant of SFAME is much higher than the value of unsaturated fatty acid methyl esters (UFAME). The lower the temperature is, the higher the solid-liquid equilibrium constant of FAME is. Thus the FAME is easier to be precipitated. However, the unsaturated fatty acid esters with a low melting point have also appeared in the wax, so the wax doesn't precipitate with the sequence of the melting point of fatty acid esters. The researching crystal precipitation of biodiesel would play an important role in optimizing its flow properties of low temperature and broadening its utilization.
Number of references:27
Main heading:Biodiesel
Controlled terms:Alternative fuels - Diesel engines - Equilibrium constants - Esterification - Esters - Liquids - Melting point - Models - Phase equilibria - Saturated fatty acids - Thermodynamics - Unsaturated fatty acids - Waxes
Uncontrolled terms:Activity coefficient model - Crystal precipitation - Fatty acid methyl ester - Regular solution model - Regular solution theory - Solid liquid equilibrium - Solid phase composition - Thermodynamic equilibria
Classification code:931.2 Physical Properties of Gases, Liquids and Solids - 902.1 Engineering Graphics - 804.1 Organic Compounds - 802.2 Chemical Reactions - 641.1 Thermodynamics - 612.2 Diesel Engines - 523 Liquid Fuels
DOI:10.3969/j.issn.1002-6819.2013.15.027
Database:Compendex
Compilation and indexing terms, Copyright 2013 Elsevier Inc.

Accession number:20133516679214
Title:Design and experiment of self-propelled air-assisted sprayer in orchard with dwarf culture
Authors:Ding, Suming (1); Fu, Ximin (1); Xue, Xinyu (1); Zhou, Liangfu (1); Lü, Xiaolan (1)
Author affiliation:(1) Nanjing Research Institute of Agricultural Mechanization, Ministry of Agriculture, Nanjing 210014, China
Corresponding author:Ding, S.(dsmchina@sina.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:15
Issue date:August 1, 2013
Publication year:2013
Pages:18-25
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:Plant protection is very important for high yield and quality of fruits production. A new self-propelled sprayer with low height was developed accommodating small space and poor trafficability of conventional orchards which are densely planted with dwarf plants. The power transmission system of the machine was optimized and the air supply atomization device was designed. The power transmission system distributes power separately, so the fan, pump, walking and steering device can be controlled independently. Designing of the air supply device and main technical parameters of key parts were based on theories of fluid mechanics and pesticide delivery technique applications. The R S channel, 9 impellers, 11 guide glades was adopted. The diameter of impellers was 0.6 m and the width of guide glades was 0.1 m. The fan property was tested and the performance curve graphic was drawn. Frequency transformer, torque meter, wind velocity indicator was used and the testing ring was put 1m ahead of the air enter which was connected with a set of rams to fan pipes. The ram's diameter are 0.6 m, as same as fan's. The results showed that air volume was 2.7 m3/s meet at 1400 r/min which demands design needs. The highest total pressure efficiency is 86% at 1600 r/min. As the speed increases, total pressure efficiency dropped rapidly but the power increased. The variation trends of the air volume and air pressure are not significant. The field experiment was conducted in an apple grove which was grown with "Jinshiji " apple trees. The experiment followed strictly the quality of air-assisted orchard sprayer (NY/T 992-2006) and evaluating regulations for the operation and spraying (GB/T17997-2008). The row space was 3 m × 2 m, diameter of the tree crown was 2 m, the height of the tree was 2.5 m. Three trees were randomly selected as sample trees. The intersection points of three horizontal layers and three vertical layers of each tree were set as sample points, that is, 27 sample points totally for one tree. Water-sensitive paper card with the same size to apple leaves were put on sample points both front and rear sides receiving droplets to measure the cover ratio of droplets. The paper cards were numbered according to the sample points. Paper cards were collected after droplets got dry. Droplets cover ratio of each paper card was measured by micro camera and droplets image processing system. Results showed that the spraying coverage and droplets density increased significantly with the increase of the fan speed, spraying manipulation was conducted at the condition of 0.5 MPa spray pressure, 1400 r/min fan speed, and 1.26 m/s velocity, the spraying coverage in front and rear of the leaf was 58.76% and 19.06% inside the tree, and 69.35% and 32.66% outside the tree crown, droplets density in front and rear of the leaf was 115 and 79 droplets/cm2 inside the tree, and 105 and 96 droplets/cm2 outside the tree crown. The operation efficiency reached to 0.91 hm2/h when the proportion of auxiliary time and operation time is one to two.
Number of references:27
Main heading:Forestry
Controlled terms:Agricultural machinery - Air - Atmospheric pressure - Drops - Electric equipment protection - Electric power transmission - Electric transformer testing - Experiments - Fruits - Image processing - Impellers - Orchards - Plants (botany) - Power transmission - Pressure control - Spraying
Uncontrolled terms:Air-assisted sprayer - Delivery techniques - Image processing system - Main technical parameters - Operation efficiencies - Power transmission systems - Self-propelled - Water sensitive paper
Classification code:901.3 Engineering Research - 715 Electronic Equipment, General Purpose and Industrial - 731.3 Specific Variables Control - 741 Light, Optics and Optical Devices - 804 Chemical Products Generally - 813.1 Coating Techniques - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 706.1.1 Electric Power Transmission - 704 Electric Components and Equipment - 602.2 Mechanical Transmissions - 601.2 Machine Components - 461.9 Biology - 443.1 Atmospheric Properties - 704.2 Electric Equipment
DOI:10.3969/j.issn.1002-6819.2013.15.003
Database:Compendex
Compilation and indexing terms, Copyright 2013 Elsevier Inc.

Accession number:20133516679220
Title:Intelligence identification for multi-class shaft centerline orbit of hydropower unit based on improved SVM model
Authors:Guo, Pengcheng (1); Li, Hui (1); Yuan, Jiangxia (1); Luo, Xingqi (1)
Author affiliation:(1) School of Hydropower Engineering, Xi'an University of Technology, Xi'an 710048, China
Corresponding author:Luo, X.(luoxq@xaut.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:15
Issue date:August 1, 2013
Publication year:2013
Pages:65-71
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:In the fault diagnosis system of hydropower units, the shaft centerline orbit is an important feature for the recognition of the unit operating condition, and different types of shaft centerline orbits reflect different operation state and fault information of shaft centerline orbit. In the actual operation of hydropower unit, there are few fault samples for shaft centerline orbits. Hence, the intelligent fault diagnosis cannot be performed accurately, and this problem must be solved with the combination of the corresponding spectral characteristics. Aimed at this problem, based on the improved support vector machine, a multi-fault classification algorithm was presented, the Hu invariant moment data of shaft centerline orbit graph were selected as training sample of the classification system, the error threshold level was inducted to effectively control category interference phenomenon, and a multi-fault shaft centerline orbits classifier was set up. Furthermore, it was applied to carry out the fault diagnosis of hydropower units. Results of the fault diagnosis application showed that just a few measured samples of shaft centerline orbits and a certain number of stimulated samples were needed in order to establish a fault classifier with superior performance, when the number of samples was 16 and 50, the classification accuracy was up to 96.3% and 91.2%, and the four different shapes of shaft centerline orbit graphs such as double ring-shaped, eight-shaped, ellipse-shaped and banana-shaped can be clearly distinguished. Meanwhile, the classification accuracy increased with an increase in the number of classification and the classification accuracy decreased rapidly with an increase in the number of sample, that is to say, the number of classification and the number of sample had an important influence on the classification accuracy. In addition, the optimum classification surface of invariant line moment can be obtained by adjustment of kernel function coefficient, the ability of multi-category classification can be obviously improved by introduction of distinct matrix, and it has been successfully verified in four different classifications. This fault classifier can realize the identification and diagnosis of multi-faults. And it has both the advantages of simple algorithm and strong capacity in pattern classification for multi-fault shaft centerline orbits. So the result provides a reference for the intelligent fault diagnosis of shaft centerline orbits of hydropower units with few fault samples.
Number of references:28
Main heading:Orbits
Controlled terms:Algorithms - Classifiers - Experiments - Failure analysis - Fault detection - Hydroelectric power - Support vector machines
Uncontrolled terms:Centerlines - Classification algorithm - Fault diagnosis applications - Hydropower units - Intelligent fault diagnosis - Linear moments - Multi-category classification - Spectral characteristics
Classification code:901.3 Engineering Research - 802.1 Chemical Plants and Equipment - 723 Computer Software, Data Handling and Applications - 921 Mathematics - 655.2 Satellites - 422 Strength of Building Materials; Test Equipment and Methods - 421 Strength of Building Materials; Mechanical Properties - 611.1 Hydroelectric Power Plants
DOI:10.3969/j.issn.1002-6819.2013.15.009
Database:Compendex
Compilation and indexing terms, Copyright 2013 Elsevier Inc.

Accession number:20133516679226
Title:Dynamics of soil water, salt and crop growth under farmyard manure and mulching in coastal tidal flat soil of northern Jiangsu Province
Authors:Zhang, Jianbing (1); Yang, Jinsong (1); Yao, Rongjiang (1); Yu, Shipeng (1); Li, Furong (1); Hou, Xiaojing (1); Jin, Wenhui (1); Wang, Xiangping (1)
Author affiliation:(1) State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; (2) Dongtai Institute of Tidal Flat, Nanjing Branch of the Chinese Academy of Sciences, Dongtai 224200, China
Corresponding author:Yang, J.(jsyang@issas.ac.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:15
Issue date:August 1, 2013
Publication year:2013
Pages:116-125
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:Soil salinity, a typical characteristic of reclaimed coastal tidal flat soil, restrains soil quality improvement and crop growth seriously in coastal area of northern Jiangsu Province. Careful soil management is important for the soil salt elimination and crop promotion. Farmyard manure (FYM) and mulch applications, which affect soil properties and plant significantly, are regarded as an effective improvement pattern of saline land. As a conventional management in the study region, FYM and mulch are used for the amendment of the new reclaimed tidal flat regularly, but little is known about their effects on crop growth and the dynamic of soil water and salt. A study was conducted on a typical coastal tidal flat saline land to evaluate the effects of FYM, polyethylene film mulch (PM), straw mulch (SM), FYM combined with PM (FYM PM), FYM combined with SM (FYM SM) on soil water, soil salinity and crop growth in 2011and 2012. CK represented no FYM and mulch application and served as a control. Dynamic of soil properties were observed, such as soil water content, electric conductivity (EC) and pH, and the growing indicators of maize and barley, including plant height, stem diameter, leaf area index, biomass and yield. The experiment, laid out in a randomized complete block design with three replications, was studied in Huanghaiyuan Farm, which specialized in the agricultural utilization for coastal tidal flat. Results of three continuous crop cultivations indicated that, soil water and salt fluctuated strongly and were affected by all of the treatments. Compared to the CK, all of the treatments increased soil water content, although with a quantitative difference. Soil salt, indicated by soil electric conductivity, was controlled well by PM and SM, with the relative decreasing percent of 23.91%, 28.57 %, 70.28% and 27.17%, 40.00%, 49.51% respectively after the three harvest time. However, FYM and mulch had weak effects on soil pH. FYM application had a risk of secondary salinization because of the increased soil salt content caused by the high salt content of chicken manure; however, the increasing trend was controlled when FYM application was combined with mulch management. Growth of maize and barley were promoted significantly with high growth index and yield and kept in the order of FYM SM &le FYM PM &le FYM &le SM &le PM &le CK. It was considered that FYM SM was the best treatment for salinity elimination and crop promotion of the reclaimed coastal tidal flat saline land, due to the higher soil water content, lower soil electric conductivity and pH and the better plant performance under FYM SM. Yield of maize and barley were increased significantly by FYM SM more than 100%, and reached the average yield of the desalted soil, which reclaimed for a long time in the study area. Therefore, the new cultivation pattern of FYM SM is recommend for soil quality and productivity improvement of the reclaimed coastal tidal flat saline land and the sustainable utilization of FYM, crop straw in the coastal area of northern Jiangsu Province.
Number of references:30
Main heading:Crops
Controlled terms:Agronomy - Coastal zones - Cultivation - Electric conductivity - Electric conductivity measurement - Fertilizers - Film growth - Manures - Reclamation - Salts - Soil moisture - Tides - Wetlands
Uncontrolled terms:Crop growth - Farmyard manure - Jiangsu province - Mulch - Tidal flat
Classification code:821 Agricultural Equipment and Methods; Vegetation and Pest Control - 804 Chemical Products Generally - 712.1 Semiconducting Materials - 701.1 Electricity: Basic Concepts and Phenomena - 942.2 Electric Variables Measurements - 483.1 Soils and Soil Mechanics - 471 Marine Science and Oceanography - 452.4 Industrial Wastes Treatment and Disposal - 452.3 Industrial Wastes - 471.4 Seawater, Tides and Waves
DOI:10.3969/j.issn.1002-6819.2013.15.015
Database:Compendex
Compilation and indexing terms, Copyright 2013 Elsevier Inc.

Accession number:20133516679242
Title:Comparison of digital mapping methods of regional soil quality
Authors:Zhang, Shiwen (1); Zhang, Liping (2); Ye, Huichun (2); Hu, Youbiao (1); Huang, Yuanfang (2)
Author affiliation:(1) School of Earth and Environment, Anhui University of Science and Technology, Huainan 232001, China; (2) Key Laboratory of Agricultural Land Quality, Monitoring and Control, College of Resoures and Enviromental Sciences, China Agricultural University, Beijing 100193, China
Corresponding author:Huang, Y.(yfhuang@china.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:15
Issue date:August 1, 2013
Publication year:2013
Pages:254-262
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:Studies on soil quality cover almost all areas of soil studies, and soil quality cartographic theory and method is an important research subject of soil quality research. Based on an established minimum data set of soil quality assessment and soil quality index calculated by the index sum method, absorbing geostatistics research, the paper tried to explore the methods of digital mapping of soil quality in the geological model support. The study designed five methods of regional digital mapping of soil quality, which included the method of digital mapping based on spatial interpolation results on single indicators (M1), the method of digital mapping based on calculated SQI and inverse distance weighting (M2), the method of digital mapping based on SQI for samples and ordinary kriging method (M3), the method of digital mapping based on calculated samples SIQ and regression kriging (M4), and the method of digital mapping based on calculated SQI and indicators interpolation results (M5), respectively, and compared spatial mapping accuracies of the different methods. We established a minimum data set of soil quality assessment using six steps including Pearson correlation analysis, principal component analysis, the calculation of the vector norm values, the relationship analysis between environmental factors and soil quality, linear transformation and parameters score calculation, and sort packet. The results showed that RMSE value for the method for soil quality digital cartography based on spatial interpolation of the results of the participating indicators (RMSE = 0.03831) is the largest, so the accuracy is the lowest, where RMSE value is minimum for the method based on calculated SQI and regression kriging (RMSE = 0.01897), so the accuracy is the highest. The size relationship of RMSE values for the five methods: M1&leM2&leM3&leM4&leM5.The precision accuracy of the M1method widely used is the minimum, the process is more cumbersome, and cannot reflect the characteristics of the highly heterogeneous landscape of the study area. For the method, the degree affected by the different participating indicators is relatively large, often showing a similar distribution pattern and some indicators, compared with the measured value of samples, prediction results are generally too large. Based on the soil quality index calculated, soil quality digital mapping method by means of geostatistical methods was relatively more scientific and reasonable, and predicted effect based on the soil quality index calculated and the regression kriging method was the best, and the relative increase in accuracy rate reached 50% more with respect to the method based on spatial interpolation results of the participating indicators. Considering the spatial mapping accuracy, the degree of sophistication of the process, the method based on the soil quality index calculated and regression kriging is optimal among the five methods of the study design, which uses a linear combination of the environment variables as an external drift trend to separate the residuals and it can eliminate smoothly, not only solve the larger problem on regression residuals, but also avoid the interpolation limitations of the highly heterogeneous landscape, and the predicted results was most consistent with the actual situation.
Number of references:36
Main heading:Soils
Controlled terms:Computer graphics - Interpolation - Mapping - Maps - Models - Principal component analysis - Quality assurance - Regression analysis - Research
Uncontrolled terms:Distribution patterns - Geo-statistics - Heterogeneous landscapes - Inverse distance weighting - Ordinary kriging methods - Pearson correlation analysis - Soil quality - Soil quality assessments
Classification code:922.2 Mathematical Statistics - 921.6 Numerical Methods - 921.4 Combinatorial Mathematics, Includes Graph Theory, Set Theory - 913.3 Quality Assurance and Control - 902.1 Engineering Graphics - 901.3 Engineering Research - 483.1 Soils and Soil Mechanics
DOI:10.3969/j.issn.1002-6819.2013.15.031
Database:Compendex
Compilation and indexing terms, Copyright 2013 Elsevier Inc.

Accession number:20133516679213
Title:Design and performance test of multi-function stove for biomass fuel
Authors:Tan, Wenying (1); Xu, Yong (1); Wang, Shuyang (2); Zuo, Guangxin (2); Dong, Shen (2); Wang, Ziman (2)
Author affiliation:(1) Material Science and Engineering of Northeast Forestry University, Harbin 150040, China; (2) Engineering Centre for Biomass Energy Technology of Northeast Forestry University, Harbin 150040, China
Corresponding author:Wang, S.(dljd2008@yahoo.com.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:15
Issue date:August 1, 2013
Publication year:2013
Pages:10-17
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:Rural China has a large number of biomass wastes, but the utilization efficiency of agricultural and forestry wastes are very low. there is a lot of waste in the traditional burning, it destroy the ecology, product indoor air pollution which affects the health of people, affect the sustainable development of rural areas. Household biomass stoves has a broad application prospects, it not only improves the thermal efficiency, reduce emissions of pollutants, conserve resources, improve the living conditions of rural residents, but also of great significance for China to achieve the sustainable development of the energy. The promotion of the biomass fuel stoves plays an important role for the promotion of the northern region the effective utilization of biomass energy. However, the biomass stoves in northern China, exist low thermal efficiency, substandard flue gas emission, tar smell, no consideration of both cooking and heating, no balance for both cooking height and climbing height of smoke which was used to warm the kang. In order to solve these problems, combined with the living habits of the rural residents in the northern region, design a biomass multi-functional stove in accordance with the relevant national standards. This design based on the design principles of biomass fuel stove, corn straw briquette fuel was used. Select layer burning as combustion method according to the fuel combustion characteristics. The main structure consists of air duct, components of grate, furnace, Cupping, circumferential water box, water jacket, chimney, feeding device, etc. The furnace volume heat release rate q<inf>max</inf> is 350 kW/h &middot m3, Furnace volume is 0.02 m3, The adjustment of the flame height is 32 cm, grating area A is 0.015 m2. The chimney cross-sectional area F is 0.0072 m2 and white metal chimney of circular cross-section of diameter 10cm was used. Automatic feeder was used and feed rate is maintained at 2.5 to 3.0 kg/h, to be completed all night (12 h) of heating demand (heating and warming kang). The biomass multi-functional stove with functions of heating, cooking, bathing etc integrated, and its performance was tested according to NB/T34005-2011 and GB/T6412-2009. The results show that the rated thermal power was 8.0 kW, thermal efficiency was 69.7%, cooking thermal efficiency was 39.2%, cooking fire intensity was 39926 J/g, comply with the requirements of the general cooking and heating stove and meet the needs of the north of peasants' lives. The integrated thermal efficiency and flue gas emission indexes were tested by Energy Conservation Monitoring Center in Heilongjiang Province according to GB/T10180-2003 and GB/T16157-1996. The integrated thermal efficiency was 78.55%, thermal efficiency is higher than other stoves, it has good energy saving effect. Flue gas emission indexes were lower than the national standard. Dust emission concentration was 14.84 mg/m3, average concentration of NO<inf>x</inf> was 138 mg/m3, average concentration of SO<inf>2</inf> was 14.8 mg/m3, average concentration of CO was 0.1%, Ringelman emittance class < 1. It has a certain significance to promote the effective utilization of biomass energy in northern China, to improve rural residents living conditions and to protect the environment.
Number of references:26
Main heading:Stoves
Controlled terms:Biomass - Chimneys - Design - Energy conservation - Experiments - Feeding - Flue gases - Fuels - Furnaces - Gas emissions - Heating - Indoor air pollution - Planning - Rural areas - Sulfur dioxide - Sustainable development - Waste incineration - Waste utilization
Uncontrolled terms:Average concentration - Circular cross-sections - Conserve resources - Cross sectional area - Energy-saving effect - Heat Release Rate (HRR) - Monitoring centers - Utilization efficiency
Classification code:532 Metallurgical Furnaces - 642.2 Industrial Furnaces and Components - 643.1 Space Heating - 691.2 Materials Handling Methods - 525.2 Energy Conservation - 804.2 Inorganic Compounds - 821.5 Agricultural Wastes - 901.3 Engineering Research - 901.4 Impact of Technology on Society - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 525.1 Energy Resources and Renewable Energy Issues - 403 Urban and Regional Planning and Development - 408 Structural Design - 451 Air Pollution - 451.1 Air Pollution Sources - 402.1 Industrial and Agricultural Buildings - 452.3 Industrial Wastes - 522 Gas Fuels - 523 Liquid Fuels - 524 Solid Fuels - 452.4 Industrial Wastes Treatment and Disposal
DOI:10.3969/j.issn.1002-6819.2013.15.002
Database:Compendex
Compilation and indexing terms, Copyright 2013 Elsevier Inc.

Accession number:20133516679235
Title:Property analysis of pyrolysis product from cotton stalk heating by microwave
Authors:Li, Pan (1); Wang, Xianhua (1); Gong, Weiting (1); Yang, Haiping (1); Chen, Yingquan (1); Chen, Hanping (1)
Author affiliation:(1) State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, China
Corresponding author:Wang, X.(wangxianhua@hust.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:15
Issue date:August 1, 2013
Publication year:2013
Pages:200-206
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:The use of microwaves for heating is well established in society, and is being used in domestic and some industrial processes. However, it has the potential to be introduced and applied to many other industrial heating processes, which offers unique advantages not attained from conventional heating. In this sense, microwave technology was being explored as one method to assist in pyrolysis process of cotton stalk. A study was carried out on the effect of microwave on the liquid and solid products, then the physicochemical properties of pyrolysis products were analyzed by gas chromatography and mass spectrometry (GC-MS), isothermal adsorption analyzer (BET) and fourier transform infrared analyzer (FT-IR). The results showed that with the rising of the pyrolysis temperature, the yields of gas and liquid products had shown opposite trend, and the highest yield of bio-oil was around 500°C (about 40%), however, the yield of char gradually decreased. Furthermore, within 550-650°C the changing rate became weaker. The bio-oil had a complex composition, and major compounds in the liquid product were acetic acid, levoglucosan and phenolic substances. Besides the content of decreased acetic acid and levoglucosan with the increasing temperature, while acetic acid obtained by microwave heating was significantly lower comparing with conventional electric heating, which made the acidity of liquid products decrease, the high content of levoglucosan in the cotton stalk oil was discovered under microwave heating, which could go up to 19.86%. In addition, phenolic substances went up with the increasing temperature when below 450°C then multi-substituted phenolic substances had been declined but the content of phenol and hydroquinone increased when above 450°C, so it changed little in total phenolics. Conventionally pyrolysed char could not be used for further application since there persisted large and deep cracks due to the overheating of surfaces, which made them fragile and lost porous nature. Analysis of the product showed the adsorption loop type was L3.Moreover, microwave heating technique was conducive to the formation of the developed pore structure and the specific surface area and micro-pore surface area were first increased and then decreased as the temperature rose, the maximum of SBET and Smic reached 400.29 m2/g and 276.93 m2/g at 550°C, which was known as microwave heating and was highly effective in pyrolysing biomass, specifically the large size which otherwise if not possible but would had been difficult. The surface functional groups of char at 350°C mainly included O-H (3500-3000 cm-1), C-Hn(2970-2860 cm-1), C=O(1730-1700 cm-1), C=C(1632cm-1), C-O-C(1260 cm-1) and C-H(900-700 cm-1), then gradually decreased as temperature increased. Only small amount of aromatic structure peak (around 1450-1600 cm-1) could be detected at 650°C, which indicated the char had been close to completely pyrolysis. The comparative results showed that microwave pyrolysis had a very good prospect on the optimization of bio-oil, getting high value-added products such as levoglucosan, and also the preparation of activated char with high specific surface area.
Number of references:30
Main heading:Liquids
Controlled terms:Acetic acid - Adsorption - Biofuels - Cotton - Functional groups - Gas chromatography - Mass spectrometry - Microwave devices - Microwave heating - Microwaves - pH - Phenols - Pyrolysis - Specific surface area - Straw - Temperature
Uncontrolled terms:Analysis of the product - Char - Fourier transform infra reds - High specific surface area - Increasing temperatures - Physicochemical property - Pyrolysis oil - Surface functional groups
Classification code:801.1 Chemistry, General - 802.2 Chemical Reactions - 802.3 Chemical Operations - 804.1 Organic Compounds - 821.4 Agricultural Products - 821.5 Agricultural Wastes - 931.2 Physical Properties of Gases, Liquids and Solids - 801 Chemistry - 523 Liquid Fuels - 524 Solid Fuels - 641.1 Thermodynamics - 711 Electromagnetic Waves - 711.1 Electromagnetic Waves in Different Media - 714 Electronic Components and Tubes - 715 Electronic Equipment, General Purpose and Industrial
DOI:10.3969/j.issn.1002-6819.2013.15.024
Database:Compendex
Compilation and indexing terms, Copyright 2013 Elsevier Inc.

Accession number:20133516679222
Title:Evolution of soil nutrient and salts in vegetable field of greenhouse in Xinxiang
Authors:Chen, Bihua (1); Sun, Li (1); Li, Xinzheng (1); Wang, Guangyin (1); Li, Yaling (2)
Author affiliation:(1) College of Horticulture and Landscape, He'nan Institute of Science and Technology, Xinxiang 453003, China; (2) College of Horticulture, Shanxi Agricultural University, Taigu 030801, China
Corresponding author:Li, Y.(yalingli@sxau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:15
Issue date:August 1, 2013
Publication year:2013
Pages:83-90
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:The production history of greenhouse was more than 30 years in Muye vegetable production base in Henan Xinxiang. The main planting pattern of this region was wheat and maize rotation before building a greenhouse, but now it is the production of cucumbers and tomatoes in a greenhouse in spring and autumn. In order to study the evolution characteristics of soil fertility and salt of the vegetable field in the greenhouse, the soil sample of the vegetable field in the greenhouse (0-20, &le 20-40 cm) in different cultivating years (0, 5, 10, 15, 20, 25, and 30) were collected and the main soil fertility index and soluble salt and soil pH values were measured. The results showed that the fertilization period of plastic house soil in Xinxiang is usually around 15 age of cultivating where the content of organic matter therein is ideal, exceeding 30 g/kg. However, at the 15th cultivating years, the contents of alkali-hydrolyzable nitrogen and rapidly available phosphorus are slightly high, exceeding 150 and 90 mg &middot kg-1respectively. Regarding the quantity of rapidly available potassium, the soil is in serious shortage of rapidly available potassium whose content is lower than 100 mg/kg, and this continues to decline after 15 cultivating years. The contents of nutrients decline as the depth of soil rises. The contents of organic matter, alkali-hydrolyzable nitrogen, and rapidly available phosphorus in soil of 0-20 cm in depth are 33%, 39.79%, and 18% higher than their contents in soil of 20-40 cm in depth. Judging from the contents of nitrogen phosphorus potassium in soil, plastic houses of different cultivating years are all in serious shortage of potassium, having an oversupply of phosphorus. Hence, great attention should be paid to the fertilization management of plastic house soil in Xinxiang city. The salinization speed of plastic house vegetable field soil slows down within the first 15 years of plantation, and it reaches 0.3% and exceeds the critical value of 0.296% at the 15th cultivating year. Then the salinization speed rises at an annual speed of 0.05%/a during the cultivating period from 15 to 30 years. Changes of contents of SO<inf>4</inf>2-, NO<inf>3</inf>-, Cl-, K , and Na agree with the change of content of water soluble salt, comprising of the main element of salt ions. The content of SO<inf>4</inf>2- goes up stably at an annual speed of 33 mg/kg after cultivating of vegetables, and it always exceeds 43% of the total content of salt ions, becoming the ion leading to salinization of soil by the largest margin. pH value of the soil declines by approximately 0.03 each year after cultivating, but stays above 7.0 all the time without any occurrence of soil acidification. The analysis indicates that soil salinization tends to synchronize with a decline of pH value of soil, which directly resulted from the application of a large amount of fertilizer. The research conclusions tend to provide a theoretical basis for fertilization decisions of the vegetable greenhouse soil of Xinxiang.
Number of references:30
Main heading:Soils
Controlled terms:Biogeochemistry - Biological materials - Chlorine - Cultivation - Fertilizers - Greenhouses - Houses - Ions - Nitrogen - Nutrients - Organic compounds - pH - Phosphorus - Vegetables
Uncontrolled terms:Available phosphorus - Cultivating years - Evolution characteristics - Salinization - Soil fertility - Vegetable Field - Vegetable greenhouse - Vegetable productions
Classification code:821 Agricultural Equipment and Methods; Vegetation and Pest Control - 804.1 Organic Compounds - 804 Chemical Products Generally - 801 Chemistry - 483.1 Soils and Soil Mechanics - 461.9 Biology - 461.2 Biological Materials and Tissue Engineering - 402.3 Residences - 402.1 Industrial and Agricultural Buildings
DOI:10.3969/j.issn.1002-6819.2013.15.011
Database:Compendex
Compilation and indexing terms, Copyright 2013 Elsevier Inc.

Accession number:20133516679218
Title:Design and experimental of venturi in EGR system of turbocharged intercooled diesel engine
Authors:Zhao, Changpu (1); Zhu, Yunyao (1); Li, Yanli (1); Liu, Guoqiang (2); Shang, Tansu (2); Zhu, Jing'an (2); Dong, Wei (2); Jiao, Tianmin (2)
Author affiliation:(1) State Key Laboratory of Engines, Tianjin University, Tianjin 300072, China; (2) YTO Group Corporation R and D Center, Luoyang 471039, China
Corresponding author:Zhao, C.(cpzhao@tju.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:15
Issue date:August 1, 2013
Publication year:2013
Pages:49-56
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:At present, most high-power diesel engines, a majority of diesel engines for automobiles and quite a large proportion of the high performance gasoline engines have adopted the turbocharged intercooled technology. However, owing to an increase of the oxygen content in the mixture after supercharging, NO<inf>x</inf>emissions in the exhaust will increase. The exhaust gas recirculation (EGR) technology is still a main method to reduce the NO<inf>x</inf> emissions. Aiming at the practical circumstances of difficulty in introducing exhaust gas recirculation (EGR) with diesel engines under the operating conditions of low speeds and full loads, a venturi was installed after the intercooler in order to improve its introduction ability of EGR. A throat diameter of a venturi was preliminarily obtained by calculating with the help of related formula, and based on this, three sorts of venturi-tubes with different structural dimensions were designed, and then some experimental research was also carried out. The results indicate that with the increase of engine speeds, the gas flow increased and the function of reducing the throat pressure of a venturi was enhanced. The difference between the pressure upstream of the EGR valve and the pressure of inside the throat of the venturi decreased first and then increased along with the speeds, and at the speed range of from 1100 r/min to 1600 r/min, this difference value was negative, so it is unfavorable to introduce EGR. At the speed of 2200 r/min and along with the increase of the engine loads, the pressure upstream of the EGR valve was always greater than the pressure upstream of a venturi and the engine could introduce EGR easily even without a venturi. However, the difference of both pressures decreased along with the increase of engine loads, which led to a lower EGR rate at high loads. The effects of reducing the throat pressure of a venturi increased and the variation of introduction ability of EGR was not obvious along with the increase of engine loads. The difference between the pressure upstream and downstream of the venturi was invariably greater than 5 kPa throughout the test load range. With the increase of engine loads, the introduction ability of EGR of the venturi with three different throat diameters had a rising trend at the speed of 2200 r/min, but the difference between the pressure upstream of an EGR valve and the throat pressure of a venturi with a smaller diameter was higher than that of the venturi with a bigger diameter, and it is favorable to realize a high EGR rate; while at the speed of 1600 r/min. The introduction ability of EGR of the venturi with three different throat diameters decreased along with the increase of engine loads. When the engine torque was above 470 N &middot m, along with the increase of the throat diameter of a venturi, the difference between the pressure upstream of the EGR valve and the pressure of inside the throat of the venturi decreased gradually, and the difficulty in introducing the EGR increased. The research results provide a reference of design and application of venturi in the EGR system of a turbocharged intercooled diesel engine.
Number of references:31
Main heading:Diesel engines
Controlled terms:Automobile engines - Emission control - Engines - Exhaust gas recirculation - Recycling - Speed
Uncontrolled terms:Design and application - Exhaust gas recirculation (EGR) - Experimental research - High performance gasoline - Introduction ability - Structural dimensions - Turbocharged inter-cooled diesel engine - Venturi
Classification code:451.2 Air Pollution Control - 452.3 Industrial Wastes - 612 Engines - 661.1 Automotive Engines - 931.1 Mechanics
DOI:10.3969/j.issn.1002-6819.2013.15.007
Database:Compendex
Compilation and indexing terms, Copyright 2013 Elsevier Inc.

Accession number:20133516679240
Title:Temporal equilibrium analysis on process of construction land expansion
Authors:Lü, Xiao (1); Huang, Xianjin (2); Zhong, Taiyang (2); Zhao, Yuntai (3); Chen, Yi (2); Chen, Zhigang (2)
Author affiliation:(1) School of Geography and Tourism, Qufu Normal University, Rizhao 276826, China; (2) School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing 210093, China; (3) China Institution of Land Surveying and Planning, Beijing 100035, China
Corresponding author:Huang, X.(hxj369@nju.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:15
Issue date:August 1, 2013
Publication year:2013
Pages:236-243
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:The purpose of this study aimed to discuss the process of construction land expansion and its relationship with economic growth. Firstly, the definitions of temporal equilibrium of construction land expansion were discussed in this research, and an integration model was built up based on coefficient of variation and decoupling mode based on IPAT. The temporal equilibrium index was calculated by this model, and it reflected the temporal equilibrium posture of construction land expansion. Furthermore, the empirical analysis took Tongzhou in Jiangsu Province for an example, and its process of construction land expansion during 1986-2008 was analyzed. The following conclusions were drawn: 1)According to the evaluation results of the coordination between construction land expansion and economic growth in the view of decoupling analysis, at 1year scale in Tongzhou, the relationship between construction land expansion and economic development was in a weak decoupling state, and there were large changes of coordination index C, proving a poor coordination. 2) Using the co-integration analysis and VAR models, we measured the interaction response cycle of economic growth and construction land expansion. Results showed that the response period was 4 years. Thus, the time scale was relaxed to 4 years. Then the relationship between construction land expansion and economic growth remained in a weak decoupling state during the 7 time phase (1986-1990, 1990-1993, 1993-1996, 1996-1999, 1999-2002, 2002-2005, 2005-2008) and the coordination index C and C' both increased firstly and then decreased, indicating that there was a growing gap between the actual rate and ideal rate of the construction land expansion. 3) The temporal equilibrium index (E) of construction land expansion referred to C and its coefficient of variation (CV). CV of construction land's annual average growth rate was higher, and showed a tendency of increased volatility in Tongzhou. Combining the above analysis and calculation results of E, the investigation shows that E of construction land expansion in Tongzhou firstly appeared to decline rapidly, and then increased slightly within a small margin, holistically indicating that its temporal equilibrium of construction land expansion was not optimistic. Many factors would affect the change of E. We concluded there was close contact between the changing trend of E and both economic growth characteristics and relevant national land use policy's implement. Finally, this paper has found that the model can depict the changes of coupling process between construction land expansion and economic growth, which provides scientific new ideas for understanding the process of regional construction land expansion.
Number of references:28
Main heading:Expansion
Controlled terms:Economic analysis - Economics - Land use
Uncontrolled terms:Analysis and calculations - Analysis of decoupling - Co-integration analysis - Coefficient of variation - Construction land - Economic development - Regional constructions - Tongzhou in Jiangsu
Classification code:403 Urban and Regional Planning and Development - 911.2 Industrial Economics - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2013.15.029
Database:Compendex
Compilation and indexing terms, Copyright 2013 Elsevier Inc.

Accession number:20133516679243
Title:Decay kinetics model of available chlorine in slightly acidic electrolyzed water in storage and disinfection process
Authors:He, Jinsong (1); Qi, Fanyu (1); Ye, Zhangying (1); Yang, Nan (1); Wei, Xiaoming (2); Zhu, Songming (1)
Author affiliation:(1) Key Laboratory of Equipment and Informatization in Environment Controlled Agriculture, College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China; (2) Institute of Facility Agriculture, Chinese Academy of Agricultural Engineering, Beijing 100125, China
Corresponding author:Zhu, S.(zhusm@zju.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:15
Issue date:August 1, 2013
Publication year:2013
Pages:263-270
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:Slightly acidic electrolyzed water (SAEW) with pH 5.0-6.5 is produced by electrolysis of dilute hydrochloric acid or salt solution in a chamber without membrane. SAEW can effectively kill various pathogenic bacteria as one of the most potential green disinfectants. However, SAEW is susceptible to be exposed to time, air, and illumination etc. To study SAEW during storage and disinfection, the variations of pH value, oxidation-reduction potential (ORP) and available chlorine concentration (ACC) were analyzed under different storage temperatures (25°C, 30°C, 35°C, 40°C, and 50°C) for 12days. Furthermore, variations in ACC during Escherichia coli (ATCC 25922) disinfection were investigated. The results showed that the pH increased, but the ORP and ACC decreased during storage. When SAEW was stored in a transparent bottle at 25°C for 12 days, the ACC of SAEW was decreased from 20.53 mg/L to 5.06 mg/L, and the ORP of SAEW was also decreased from 821 mv to 641 mv, while pH was increased from 6.06 to 7.45 in the same condition. Variations of ACC, ORP, and pH in a brown bottle under same stored temperatures had a similar tendency. When SAEW was stored in a brown bottle at 25°C for 12days, the ACC of SAEW was also decreased and the ORP of SAEW was decreased from 821mv to 652 mv, while pH was increased from 6.06 to 7.38. The higher the stored temperature was, the quicker ACC, ORP, and pH of SAEW decayed during storage. SAEW was stored in a transparent bottle at 50°C for 12days, and the ACC of SAEW was decreased from 20.53 mg/L to 0.10 mg/L and the ORP from 821 mv to 641 mv, while pH was increased from 6.06 to 8.11in the same condition. Similarly, when SAEW was stored in a brown bottle at 50°C for 12days, the ACC of SAEW was decreased from 20.53 mg/L to 0 and the ORP from 821 mv to 583 mv, while pH was increased from 6.06 to 8.03 in same condition. The same tendency of ACC was also found during E. coli disinfection, but the decay of ACC was quicker than it was presented during storage. The ACC of SAEW was reduced by 15.05 mg/L after SAEW with ACC of 25.13 mg/L was used to disinfect for 25 min., compared with the above storage condition for five days. The decay kinetics models of the ACC in SAEW during storage and disinfection were established and the correlation coefficients were above 0.90. The temperature and duration of storage and disinfection had significant impacts on the physicochemical properties of SAEW. As the stored time prolonged, the ACC and ORP of SAEW was decreased while pH increased. The higher the stored temperature was, the larger the variation of amplitude of ACC, ORP, and pH of SAEW. The decay of ACC was quicker during disinfection than it was presented during storage and active chlorine needed to be expended during the disinfection process. The decay of ACC followed first-order kinetics during the storage and disinfection process, and the values of the kinetic parameters during the storage process were higher than it were presented during the disinfection process, and the value of k' of storage and disinfection was 0.108 (±0.044) and 0.043 (±0.005) respectively under the condition of ACC of 25.13 mg/L at 25°C.
Number of references:31
Main heading:Bottles
Controlled terms:Chlorine - Decay (organic) - Disinfection - Energy storage - Enzyme kinetics - Escherichia coli - Kinetics - Models - Redox reactions
Uncontrolled terms:Available chlorine concentrations - Correlation coefficient - E. coli disinfections - Oxidation-reduction potentials - Pathogenic bacterium - Physicochemical property - Slightly acidic electrolyzed waters - Storage temperatures
Classification code:902.1 Engineering Graphics - 804 Chemical Products Generally - 802.2 Chemical Reactions - 931 Classical Physics; Quantum Theory; Relativity - 702 Electric Batteries and Fuel Cells - 462 Biomedical Equipment - 461.9 Biology - 694.2 Packaging Materials
DOI:10.3969/j.issn.1002-6819.2013.15.032
Database:Compendex
Compilation and indexing terms, Copyright 2013 Elsevier Inc.

Accession number:20133516679233
Title:Effect of biochar returning to paddy field on CH<inf>4</inf> emission reduction
Authors:Jiang, Chen (1); Ma, Peixia (1); Hu, Baoguo (1); Zhao, Haixia (1); Fang, Xiaobo (1); Li, Song (1); Ren, Jingming (1)
Author affiliation:(1) School of Environmental and Resource Sciences, Zhejiang Agriculture and Forestry University, Hangzhou 311300, China; (2) Assessment Center of Environment Engineering, Ministry of Environmental Protection of China, Beijing 100012, China
Corresponding author:Li, S.(lisong66@yahoo.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:15
Issue date:August 1, 2013
Publication year:2013
Pages:184-191
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:Biochar returning may be an important way to deal with climate change for mankind. To investigate the effects of different biochar types, returning amount, returning time and returning depth on CH<inf>4</inf> emission, a greenhouse experiment of CH<inf>4</inf> emissions with three different biochar, namely rice carbon (RC), wheat carbon (WC), bamboo carbon (BC) applied on the paddy field and no biochar application as a control (CK), was conducted by using the static chamber-GC (gas chromatography) method during the rice growing season (2011-2012). The results showed that the yield was significantly increased (P<0.05) after different biochar returning compared with the control treatment(CK), and the highest filled grain weight of BC treatment reached 18.12 g per pot, which showed biochar returning can effectively increase rice yield. The CH<inf>4</inf> emission flux of BC treatment was significantly higher (P<0.05) than that of WC and RC treatments, and for the later two treatments, there were no significant differences (P&le0.05), but they were significant higher (P<0.05) than that of CK, which showed biochar returning can decrease CH<inf>4</inf> emission efficiently. A linear negative correlation was found between CH<inf>4</inf> emission flux and biochar application amount, and CH<inf>4</inf> emission flux declined gradually with the increase of the cycle of biochar returning amount. Meanwhile, the CH<inf>4</inf> emission flux of bamboo carbon (BC) returning before rice transplantation (BRT, 56.6 mg &middot m-2&middot h-1) was not significant lower (P&le0.05) than those of CK (96 mg &middot m-2&middot h-1) and before rice survival (BRS, 73.4 mg &middot m-2&middot h-1) or after rice survival(ARS, 76.6 mg &middot m-2 &middot h-1), which was consistent to the change of soil redox potential (Eh) and showed biochar returning time has little effect on CH<inf>4</inf> emission flux. In addition, the sequence of CH<inf>4</inf> emission flux in different biochar returning depth was on the order of middle returning(MR) <surface returning(SR) <deep returning(DR)<CK, which showed biochar middle returning(MR) was more beneficial to the growth of soil microorganism and mitigation of CH<inf>4</inf> emissions. This study provides references for the enhancement of carbon sequestration and mitigation of CH<inf>4</inf> emissions in the Tiaoxi Watershed of Tai Lake region.
Number of references:28
Main heading:Carbon
Controlled terms:Bamboo - Climate change - Emission control - Gas chromatography - Methane - Soils
Uncontrolled terms:Bio chars - Carbon sequestration - Emission fluxes - Emission reduction - Greenhouse experiments - Negative correlation - Soil micro-organisms - Soil redox potential
Classification code:821.4 Agricultural Products - 804 Chemical Products Generally - 801 Chemistry - 522 Gas Fuels - 483.1 Soils and Soil Mechanics - 451.2 Air Pollution Control - 451 Air Pollution
DOI:10.3969/j.issn.1002-6819.2013.15.022
Database:Compendex
Compilation and indexing terms, Copyright 2013 Elsevier Inc.

Accession number:20133516679229
Title:Extracting oilseed rape growing regions based on variation characteristics of red edge position
Authors:She, Bao (1); Huang, Jingfeng (1); Shi, Jingjing (1); Wei, Chuanwen (1)
Author affiliation:(1) Institute of Agricultural Remote Sensing and Information Technology Application, Zhejiang University, Hangzhou 310058, China
Corresponding author:Huang, J.(hjf@zju.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:15
Issue date:August 1, 2013
Publication year:2013
Pages:145-152
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:The accurate extraction of oilseed rape growing regions is the premise of growth monitoring, yield estimation and disaster assessment, and remote sensing has been proved to be an effective way for this task. Hyperspectral remote sensing has the features of many more bands, higher spectral resolution, being rich in information and so on, which provides new technical means for extracting oilseed rape growing regions. Changxing, the county with the largest oilseed rape cultivated area in Zhejiang Province was selected to be the study area in this paper, and two EO-1Hyperion images acquired on April 4th and May 6th, 2004 were adopted, corresponding to the full-bloom stage and pod stage respectively for oilseed rape growing in this region. After detailedly preprocessing of L1R data, the "linear four-point interpolation" method was adopted to get the red edge position (REP) of both stages. REP statistical histograms of typical oilseed rape growing regions and woodland covering both stages were generated and analyzed. The result showed that for both oilseed rape and woodland, the histograms spanning the two stages didn't have overlaps, and for oilseed rape, the REP value demonstrated an obviously "blue shift" characteristic from April 4th to May 6th. On the contrary, the REP value of woodland demonstrated clearly "red shift" characteristic during the same period, which was distinct from oilseed rape. Ignoring other over wintering crops like winter wheat because of the small amount of planting in Changxing that year, and according to the unique "blue shift" characteristic for oilseed rape from full-bloom stage to pod stage, differing from other vegetations, a "decision tree" was built, containing the algorithms of eliminating non-vegetation areas, non-oilseed rape growing regions, and pseudo-growing regions. Then oilseed rape growing regions were extracted based on this method. Next, the result was verified through 500 random sampling points combined with a visual interpretation method, the points were generated within the common coverage of both images, and among them 124 points were located in oilseed rape growing regions. The verification was performed employing an ENVI-ROI tool, and the result showed that the omission error and commission error were 13.7% and 15.7% respectively, total accuracy was 92.6%, and the Kappa coefficient reached up to 0.803, all above indicating that the research had achieved good results. The method provided by this paper takes full advantage of hyperspectral remote sensing, which can retrieve red edge parameters of vegetation with only a few bands, and gets rid of traditional information extracting methods like spectral match. Moreover, the accuracy is not sensitive to spectral differences of surface features, so it has every qualification to be a set of new ideas and solutions for extraction of oilseed rape growing regions by remote sensing.
Number of references:24
Main heading:Oilseeds
Controlled terms:Blooms (metal) - Crops - Cultivation - Data mining - Decision trees - Extraction - Graphic methods - Image matching - Remote sensing - Vegetation
Uncontrolled terms:Growing regions - Hyperion - HyperSpectral - Oil seed rape - Red edge position
Classification code:961 Systems Science - 922 Statistical Methods - 902.1 Engineering Graphics - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 802.3 Chemical Operations - 741 Light, Optics and Optical Devices - 731.1 Control Systems - 723.3 Database Systems - 535.1.2 Rolling Mill Practice
DOI:10.3969/j.issn.1002-6819.2013.15.018
Database:Compendex
Compilation and indexing terms, Copyright 2013 Elsevier Inc.

Accession number:20133516679231
Title:Vegetation filtering in gully region of loess plateau based on laser scanning point cloud's intensity attenuation model and its terrain construct
Authors:Ma, Ding (1); Li, Binbing (2)
Author affiliation:(1) Graduate Management Group, Engineering University of Chinese Armed Police Force, Xi'an 710086, China; (2) Department of Information Engineering, Engineering University of Chinese Armed Police Force, Xi'an 710086, China
Corresponding author:Li, B.(libinbing8@vip.sina.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:15
Issue date:August 1, 2013
Publication year:2013
Pages:162-171
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:The point cloud data of a gully region in loess plateau via Terrestrial Laser Scan (TLS) was characterized by uneven distribution of laser footprints, rapid geomorphologic change, and high density of herbaceous vegetation. In order to improve the precision of gully DEM, this paper proposes a vegetation filtering method of TLS point cloud. We first use laser return intensity to make an applicable classification. It is significant to compensate intensity attenuation which is brought by distance, angle of incidence, and environment, and establish a unified relationship between object and return light intensity. Available data indicates that return intensity is represented by an inverse second-order-dependent function of distance and other parameters can be treated as a constant in one experiment. We built a distance attenuation model of return light intensity. We can calculate the attenuation factor based on it and then compensate for laser return intensity of the whole point cloud. In this study, the return intensities of six sphere targets are used to build an attenuation model, and we obtained the attenuation factor as 0.3173. With the unified return intensity, each point's intensity deviation with intensity of the ground was used as a weight to enlarge the difference of non-ground points and ground points. Then we used segmentation and surface fitting method to calculate each point's distance to the trend surface, and set the threshold to separate the ground points and vegetation points. In this study, we propose an adaptive mesh grid filtering method integrated with return light intensity. In this method, we updated the distance to the trend surface though each point's intensity weight which has a linear relationship with its intensity deviation. Besides, the adaptive segmentation is more fast and effective than the K neighborhood search method. The method's reliability was tested through a point cloud acquired from a typical gully in Qiaozi Valley, Tianshui City of Gansu Province. It was located in 105°43′2″E, 34°36′59″N. The section is a typical V shape, and 90% of the surface is covered with low vegetation like grass and leguminous plant. The gully was scanned with a Leica HDS6100 3D laser scanner with a precision of 1mm. The cloud data containd 1,498,191 points, return light intensity varied from -2048 to -2047, covered an area of 14.0975 m2 and the average point density was 3345.1 points/m2. We practiced the adaptive mesh grid-filtering algorithm in Matlab, and iterated three times to get filtering result. There were 160 517 vegetation points which were removed from data, and they were 34.04% of the whole point cloud. Comparing the filtered DEM with the original one, we proved that this filtering method can overcome negative influences of uneven terrain and high vegetation coverage and filter efficiently. It reduces the elevation root-mean-square error (RMSE) of point cloud from 0.1430 to 0.1324, and most rags of original contour lines decrease and ground characteristics are well preserved. In addition, we compared this method with the intensity-classification method and surface fitting method, and found that this paper's filtering method performs better. Furthermore, we got a typical gully vegetation probability distribution of Qiaozi Valley by calculating the cumulative probability of filtered and original DEMs' deviation. It can explain the gully morphologic change, and the change coincides with the observation data. It proved that vegetation is effective in sand binding and reduction and slope impaction. Consequently, this study not only provides a new approach to filter gully vegetation in point cloud and acquiring high-precision DEM, but also helps to set the stage for future research to monitor gully morphologic change and control soil erosion.
Number of references:28
Main heading:Landforms
Controlled terms:Automobile radiators - Fiber optic sensors - Laser applications - Models - Probability distributions - Soil conservation - Surveying instruments - Vegetation
Uncontrolled terms:Cumulative probabilities - Geomorphologic changes - Laser return - Laser scanning point clouds - Loess Plateau - Point cloud - Root-mean-square errors - Terrestrial laser scans
Classification code:941 Acoustical and Optical Measuring Instruments - 922.1 Probability Theory - 902.1 Engineering Graphics - 821.3 Agricultural Methods - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 744.9 Laser Applications - 732.2 Control Instrumentation - 663.2 Heavy Duty Motor Vehicle Components - 481.1 Geology
DOI:10.3969/j.issn.1002-6819.2013.15.020
Database:Compendex
Compilation and indexing terms, Copyright 2013 Elsevier Inc.

Accession number:20133516679247
Title:Ultrasound-surfactant synergistic extraction of saponins from balsam pear
Authors:Yu, Bin (1); Ge, Bangguo (2); Song, Ye (2); Li, Dandan (2); Ma, Xiaoyan (2); Wu, Maoyu (2)
Author affiliation:(1) College of Life Science, Zaozhuang University, Zaozhuang 277160, China; (2) Jinan Fruit Research Institute, All China Federation of Supply and Marketing Cooperatives, Ji'nan 250014, China
Corresponding author:Wu, M.(wmyu1972@sohu.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:15
Issue date:August 1, 2013
Publication year:2013
Pages:294-300
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:Balsam pear (Momordica charantia L.), a climber belonging to family Cucurbitaceae, is commonly known as bitter gourd or bitter melon in English. It is cultivated throughout the world for use as vegetable as well as medicine. Balsam pear has been used traditionally as medicine in developing countries. Some of its common uses in most countries are for diabetes, a carminative and in treatment of colics. Topically it is used for treatment of wounds, internally as well as externally for management of worms and parasites. It is also used as emmenagogue, antiviral for measles and hepatitis. Balsam pear contains biologically active chemicals that include glycosides, saponins, alkaloids, fixedoils, triterpenes. Saponins from all parts of the plant (fruit pulp, seed, leaves and whole plant) are most widely studied with regard to its antidiabetic effect. Ultrasound and surfactants have been individually shown to enhance saponins extraction. In this study, we investigated the synergistic effect of ultrasound and surfactants on saponins extraction. In order to explore effective extracting method of saponins from balsam pear, response surface was used to study the effect of ultrasonic power (133-167 W/g), ethanol volume fraction (60%-80%) and mass concentrations of SDS (15-25 mg/mL) on extraction rate of saponins from balsam pear. Ultrasound-surfactant synergistic extraction was compared with ethanol and ultrasound, respectively. The structures of the prepared saponins from balsam pear were identified. Results showed that the established model of extraction could well predict extraction rate of saponins from balsam pear under different conditions. Extraction rate of saponins from balsam pear was significantly (p<0.05) influenced by ultrasonic power, ethanol volume fraction and mass concentrations of SDS, and there was synergistic effect between ultrasonic power and the mass concentration of SDS. Various factors affecting extraction rate of saponins from balsam pear in a descending order was as follows: mass concentrations of SDS, ultrasonic power, ethanol volume fraction. Extraction rate of saponins from balsam pear was 3.22% at ultrasonic power of 153 W/g, ethanol volume fraction of 74%, mass concentrations of SDS of 16 mg/mL, significantly higher (p<0.05) than that of ethanol and ultrasound extraction. Liquid chromatography-mass spectrometry revealed that extracted saponins included momordicoside L and F<inf>2</inf>. Ultrasound-surfactant synergistic extraction is an effective method for extraction of saponins, which is worth further development and application.
Number of references:29
Main heading:Metabolites
Controlled terms:Developing countries - Ethanol - Extraction - Fruits - Models - Optimization - Plants (botany) - Seed - Surface active agents - Ultrasonic waves - Ultrasonics - Volume fraction
Uncontrolled terms:Antidiabetic effects - Development and applications - Extraction of saponins - Liquid chromatography-Mass spectrometry - Saponins from balsam pear - Structure identification - Synergistic extraction - Ultrasound extractions
Classification code:921.5 Optimization Techniques - 902.1 Engineering Graphics - 901.4 Impact of Technology on Society - 821.4 Agricultural Products - 803 Chemical Agents and Basic Industrial Chemicals - 802.3 Chemical Operations - 753.1 Ultrasonic Waves - 641.1 Thermodynamics - 523 Liquid Fuels - 461.9 Biology - 461.2 Biological Materials and Tissue Engineering
DOI:10.3969/j.issn.1002-6819.2013.15.036
Database:Compendex
Compilation and indexing terms, Copyright 2013 Elsevier Inc.

Accession number:20133516679219
Title:Torsional vibration analysis of planetary hybrid electric vehicle driveline
Authors:Yu, Haisheng (1); Zhang, Tong (1); Ma, Zhitao (1); Wang, Ruiping (1)
Author affiliation:(1) Zhejiang Geely Luo You Engine Co., Ltd, Ningbo 315800, China
Corresponding author:Yu, H.(yhsdg@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:15
Issue date:August 1, 2013
Publication year:2013
Pages:57-64
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:Noise, Vibration, and Harshness (NVH) are important factors with which to evaluate a vehicle. The automotive industry pays more and more attention to NVH to meet the growing comfort expectation of customers. Therefore, the noise and vibration analysis of the hybrid electric vehicles (HEVs) is significantly meaningful. In order to investigate the torsional vibration behavior of a planetary power split hybrid electric vehicle (HEV), the MEEBS hybrid driveline was studied by the dynamic equation. The compound planetary gear set in this HEV consists of a ring, a carrier, a small sun gear 1, a big sun gear 2, three short planets, and three long planets. All the short and long planets are mounted on the carrier. The compound planetary gear set has two rows. The first planetary row is made up of sun gear 1, short planets, and the ring, while the second planetary row consists of sun gear 2, short planets, long planets, and the ring. The planetary rows share the carrier and the ring. The short planet and corresponding long planet engage with each other. The sun gear 1and sun gear 2are connected to electrical motors E1and E2, respectively. Both motors are permanent magnetic synchronous machines. The carrier was connected to the engine through a torsional damper. All of the system output torque was exported to the ring, and then to the wheels through the reducer, differential, and halfshafts. Compared with the traditional Ravingneaux gear set, the power-split system can increase the lever efficiency of the second row to reduce the requirement power of E2, leading to decreased system cost. Compared with the traditional Ravingneaux gear set, the power-split system can increase the lever efficiency of the second row to reduce the requirement power of E2, leading to decreased system cost. In order to realize the optimizing control in electric-only mode and make the engine work in the optimum working zone, the power-split system also has two brakes to lock the carrier and S1, respectively. Numerical results for natural frequencies and corresponding modes of the hybrid driveline are produced. The forced torsional vibrations under different excitations and parameters were analyzed. The main factors that influence the torsional vibration of the driveline were found out. The results show that the low-order frequencies are focused on the vehicle and wheels, while the high-orders are concentrated on the differential, reducer, and planets. The results also show that the amplitude of the torsional vibration of the driveline is the lowest when the damping and stiffness of the torsional damper were 15 N &middot m &middot s/rad and 618 N &middot m/rad respectively and the rotational inertial of flywheel was 0.42kg &middot m2. The research can provide a reference to improve the vibration and noise levels of HEVs.
Number of references:25
Main heading:Hybrid vehicles
Controlled terms:Automotive industry - Cost reduction - Elastic waves - Electric brakes - Engines - Epicyclic gears - Machine vibrations - Planets - Synchronous motors - Transmissions - Vehicle transmissions - Vehicles - Vibration analysis - Wheels
Uncontrolled terms:Hybrid electric vehicles (HEVs) - Hybrid-electric vehicles - Multi-body dynamic - Noise , vibration , and harshness - Planetary gear sets - Power split hybrid electric vehicles - Torsional vibration - Torsional vibration analysis
Classification code:662 Automobiles and Smaller Vehicles - 663 Buses, Tractors and Trucks - 664 Automotive Engineering, General - 705.3.1 AC Motors - 751.1 Acoustic Waves - 911.2 Industrial Economics - 943.2 Mechanical Variables Measurements - 661 Automotive Engines and Related Equipment - 432 Highway Transportation - 601.2 Machine Components - 601.3 Mechanisms - 602 Mechanical Drives and Transmissions - 602.2 Mechanical Transmissions - 612 Engines - 657.2 Extraterrestrial Physics and Stellar Phenomena
DOI:10.3969/j.issn.1002-6819.2013.15.008
Database:Compendex
Compilation and indexing terms, Copyright 2013 Elsevier Inc.

Accession number:20133516679221
Title:Analysis of spatial and temporal characteristics of water requirement of winter wheat in China
Authors:Sun, Shuang (1); Yang, Xiaoguang (1); Li, Ke'nan (1); Zhao, Jin (1); Ye, Qing (1); Xie, Wenjuan (1); Dong, Chaoyang (1); Liu, Huan (1)
Author affiliation:(1) College of Resources and Environmental Science, China Agricultural University, Beijing 100193, China; (2) College of Landscape Architecture and Art, Jiangxi Agricultural University, Nanchang 330045, China; (3) College of Agronomy, Shenyang Agricultural University, Shenyang 110866, China
Corresponding author:Yang, X.(yangxg@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:15
Issue date:August 1, 2013
Publication year:2013
Pages:72-82
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:Crop water requirement (ET<inf>C</inf>) is the basis for farmland water management and irrigation.Based on the meteorological data from 356 stations of 22 provinces (cities, and autonomous regions) and the data of the growth period of the winter planting area in China, the water requirement (ET<inf>C</inf>) of winter wheat of the whole growing period and different growth stages during 1961-2010 in China were estimated by using FAO Penman-Monteith equation and crop coefficient method, and the spatial and temporal distribution characteristics of ETC were cleared. Combined with the spatial distribution characteristics of precipitation, the water-meeting situation of winter wheat during the growing season was analysed. Results revealed that the spatial distribution characteristics of precipitation of the whole growing period and different growth stages of winter wheat were all significant which were higher in the southeast coast areas and lower in the northwest areas except the growth stage of sowing to over wintering (emergence). Except during the growth stage of turning green (emergence) to jointing, the spatial distribution characteristics of ET<inf>C</inf> of the whole growing period and different growth stages of winter wheat were all significant, which were higher in the northwest and lower in the southeast. The ET<inf>C</inf> of winter wheat of the whole growing period and different growth stages were decreased over nearly the past 50 years, especially the whole growing period and the growth stage of flowering-to-ripening. The growth stage of turning green (emergence) to jointing decreased the slowest. From the national average angle, except for the regions of Huanan and the lower reaches of Yangtze River where the conditions of water-meeting were better, the precipitation of the whole growing period and different growth stages of winter wheat can not meet the demand of water in other regions, ignoring the irrigation conditions. Comparing the water-meeting of winter wheat of the typical stations of different regions, the water deficit is most serious in the winter wheat regions of the North, the Huanghuai, Xinjiang and the Southwest. By comparing the water deficit of the most serious areas, the growth stage of the water deficit of the least seriously is from sowing to over wintering and the growth stage of the water deficit of the most seriously is from flowering to ripening, which is the most important stage for the grain weight of winter wheat, So timely irrigation is very important if conditions permit, which is the key to ensure a high and stable yield.
Number of references:26
Main heading:Crops
Controlled terms:Grain growth - Irrigation - Meteorology - Precipitation (chemical) - Precipitation (meteorology) - Spatial distribution - Water management
Uncontrolled terms:Crop water requirements - Distribution characteristics - Growing regions - Spatial and temporal distribution - Spatial-temporal distribution - Temporal characteristics - Water requirements - Winter wheat
Classification code:821.4 Agricultural Products - 821.3 Agricultural Methods - 802.3 Chemical Operations - 921 Mathematics - 446 Waterworks - 443.3 Precipitation - 443 Meteorology - 444 Water Resources
DOI:10.3969/j.issn.1002-6819.2013.15.010
Database:Compendex
Compilation and indexing terms, Copyright 2013 Elsevier Inc.

Accession number:20133516679232
Title:Development of traceability system of aquatic foods supply chain based on RFID and EPC internet of things
Authors:Yan, Bo (1); Shi, Ping (1); Huang, Guangwen (1)
Author affiliation:(1) School of Economics and Commerce, South China University of Technology, Guangzhou 510006, China
Corresponding author:Yan, B.(yanbo@scut.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:15
Issue date:August 1, 2013
Publication year:2013
Pages:172-183
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:Food safety has become an important global public-health issue, and aquatic safety issues were never suspended. With the exposure and the emergence of some aquatic products'quality and safety issues in China, safety issues for the quality of aquatic products has become the bottleneck of the sustainable development of fisheries and aquatic products for import and export trade. In response to the risk in the aquatic foods supply chain and to improve services, the traceable platform of the aquatic foods supply chain is highly required. Quality problems of aquatic products could occur in every aspect of the aquatic foods supply chain, including breeding, processing, distribution, and sale. So not only policies, but also technical supports are needed to ensure the quality and safety of aquatic products and to bottom out the safety hazards. In response to these issues, this paper takes tilapia as the object of study and designs and develops a traceable platform of the aquatic foods supply chain based on Radio Frequency Identification (RFID) and Electronic Product Code (EPC) Internet of Things, and focuses on designing Object Name Service (ONS) and EPC Information Service (EPCIS) of this platform. Tracking, traceability, recall, and monitoring of tilapia products in the food supply chain can be achieved with the participation of consumers, enterprises, and the government. This platform contains an aquaculture management system, process management system, distribution management system, sales management system, and querying and monitoring system, and realizes all-the-way traceability of aquatic products from breeding, processing, and distribution to sales. This platform has the following characteristics: 1) It has a monitoring function of tilapia farming, and can track and trace all aspects of information from breeding, production, processing, and distribution to sale; 2) It brings out informationization on the production and management of enterprises, and achieves all-the-way monitoring of tilapia's quality and safety through the construction of information technology; 3) It has three functions including water quality monitoring, early warning of tilapia's epidemic, and early warning of the risks of tilapia's quality and safety, which facilitates enterprise management and supervision of tilapia's quality for quality supervision departments; 4) Consumers can inquire and complain about tilapia product information on the traceability platform. Feedback information will be dealt with promptly to protect the consumer equity. The platform combines the use of RFID technology and bar code technology. RFID tags are used from breeding to store, and barcode labels are attached to the independent small package in the final form for the users to query, which can meet the required functionality and save some costs. In addition, the EPC can uniquely identify products, thus through the use of the EPC global coding standard and read-write RFID tags, RFID tags can be recycled by rewriting the EPC encoded in the tags, which can reduce the production and management costs. In this platform, consumers are the main users and the final beneficiaries, through trace codes. Consumers can acquire information of suppliers and products, which enhances their desire to purchase products and improves their faith. Enterprises can use the retrospective mechanism of this platform to reduce costs and risks, and to win market opportunities. Government's involvement is a major highlight of the platform, which proposes the possibility of supervision and protection of agricultural products' quality and safety management. The traceability platform has been on probation in two companies, including the World Agricultural Development Co. Ltd and MAIKOUGUAI Food Company, and produced a good effect on the turnover and market satisfaction of the products. Furthermore, research on this subject provides a good clue for the establishment of a traceability system for meat, vegetables, and other foods.
Number of references:30
Main heading:Radio frequency identification (RFID)
Controlled terms:Agricultural products - Aquaculture - Bar codes - Commerce - Cost reduction - Food safety - Food supply - Information services - Information technology - Internet - Management - Quality control - Safety engineering - Sales - Supply chains - Water quality
Uncontrolled terms:Agricultural development - Distribution management systems - Electronic product codes - Internet of Things (IOT) - Process management systems - Required functionalities - Traceability systems - Water quality monitoring
Classification code:821.4 Agricultural Products - 903 Information Science - 903.4 Information Services - 911.4 Marketing - 912 Industrial Engineering and Management - 912.2 Management - 913 Production Planning and Control; Manufacturing - 913.3 Quality Assurance and Control - 914 Safety Engineering - 821.3 Agricultural Methods - 404.2 Civil Defense - 453.2 Water Pollution Control - 461.6 Medicine and Pharmacology - 716 Telecommunication; Radar, Radio and Television - 716.3 Radio Systems and Equipment - 717 Optical Communication - 718 Telephone Systems and Related Technologies; Line Communications - 723 Computer Software, Data Handling and Applications - 723.2 Data Processing and Image Processing
DOI:10.3969/j.issn.1002-6819.2013.15.021
Database:Compendex
Compilation and indexing terms, Copyright 2013 Elsevier Inc.

Accession number:20133516679236
Title:Characteristic of methane oxidation coupled to denitrification in cover soils of landfill
Authors:Long, Yan (1); Zhong, Zhuangmin (1); Yin, Hua (3); Lin, Zhiyong (1); Ye, Jinshao (1); He, Baoyan (1)
Author affiliation:(1) Department of Environmental Engineering, Jinan University, Guangzhou 510632, China; (2) Key Lab. of Water/Soil Toxic Pollutants Control and Bioremediation of Guangdong Higher Edu. Inst., Jinan University, Guangzhou 510632, China; (3) School of Environmental Science and Engineering, South China University of Technology, Guangzhou 510640, China
Corresponding author:Long, Y.(dragonflamely@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:15
Issue date:August 1, 2013
Publication year:2013
Pages:207-214
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:Methane (CH<inf>4</inf>) is widely concerned because of its strong greenhouse effect. The CH<inf>4</inf> generated from anaerobic biodegradation of waste in landfills is a significant source of atmospheric CH<inf>4</inf>. The CH<inf>4</inf> generated transits the soil cover where it maybe be partly oxidized by CH<inf>4</inf>-oxidizing bacteria. Therefore, the landfill soil cover has a function on reducing CH<inf>4</inf> emissions. On the other hand, N-pollution of leachate is the problem that must be controlled. According to documents, CH<inf>4</inf> is a potentially inexpensive, widely available electron donor for biological denitrification of landfill leachate. Although no known methanotroph is able to denitrify, various consortia of microorganisms using methane as the sole carbon source which carry out denitrification both aerobically and anaerobically. Aerobic methane-oxidation coupled to denitrification (AME-D) is accomplished by aerobic methanotrophs oxidizing methane and releasing soluble organics that are used by coexisting denitrifiers as electron donors for denitrification. The work aimed to investigate the characteristics of AME-D in the cover soil of landfill. Thus, the batch assays were performed to investigate the effects of different factors such as CH<inf>4</inf>, O<inf>2</inf> and NO<inf>3</inf>--N with different contents on AME-D. The concentration levels of CH<inf>4</inf> were 0, 10, 20 and 30%, those of O<inf>2</inf> were 0, 5, 10 and 20%, and those of NO<inf>3</inf>--N were 0, 100, 200 and 300 mg/kg. In the assays, we first added 10 g of soil and NO<inf>3</inf>--N solution into 50 mL serum bottle with gas-tight rubber stoppers, then displaced the upper air in the bottle with argon gas and injected corresponding CH<inf>4</inf> and O<inf>2</inf> with syringe to make up the initial content, and finally incubated them at 30°C for 7 d. The CH<inf>4</inf>, O<inf>2</inf>, CO<inf>2</inf>, N<inf>2</inf> and N<inf>2</inf>O of gas samples in the third and seventh day were analyzed with a gas chromatograph (Fuli 9790, equipped with tandem connect of PorparkQ and 5A&ring; molecular sieve packed columns, and a thermal conductivity detector). Ar was used as carrier gas and its flow rate was 30 mL-1&middot min. Injector, oven, and detector temperatures were 50, 50, and 85°C, respectively. The results showed that the landfill cover soil was favorable for AME-D. The contents of CH<inf>4</inf>, O<inf>2</inf> and NO<inf>3</inf>--N had significant influences on the CH<inf>4</inf> oxidation (p<0.05, and followed the order of CH<inf>4</inf><O<inf>2</inf>NO<inf>3</inf>--N. Furthermore, the CH<inf>4</inf> and O<inf>2</inf> took significant interactions (p<0.05). The removal of CH<inf>4</inf> increased as the increase of CH<inf>4</inf> and O<inf>2</inf>, and was positively correlated with O<inf>2</inf> concentration (n=144, r=0.786, p<0.01). The factor that had significant influences on the production of N<inf>2</inf> was not NO<inf>3</inf>--N but CH<inf>4</inf> and O<inf>2</inf> (p<0.05). However, NO<inf>3</inf>--N and O<inf>2</inf>, CH<inf>4</inf> and O<inf>2</inf> took significant interactions (p<0.01) on the production of N<inf>2</inf>. The addition of NO<inf>3</inf>--N enhanced the product of N<inf>2</inf> under low O<inf>2</inf> content (<5%), while it took no effect under low O<inf>2</inf> content (≥10%). The effects of C/O ratios on AME-D depended on the contents of O<inf>2</inf> and CH<inf>4</inf>, the optimal range of C/O ratio was from 0.5 to 1.0. In the experiment, the AME-D coupled well as the contents of CH<inf>4</inf>, O<inf>2</inf> and NO<inf>3</inf>--N were 20%, 20% and 100 mg/kg.
Number of references:23
Main heading:Leachate treatment
Controlled terms:Argon - Bottles - Carbon dioxide - Denitrification - Methane - Molecular sieves - Oxidation - Soils - Thermal conductivity of gases
Uncontrolled terms:Anaerobic biodegradation - Biological denitrification - Concentration levels - Landfill leachates - Landfill-cover soils - Soil cover - Sole carbon source - Thermal conductivity detectors
Classification code:804 Chemical Products Generally - 803 Chemical Agents and Basic Industrial Chemicals - 802.2 Chemical Reactions - 804.2 Inorganic Compounds - 694.2 Packaging Materials - 522 Gas Fuels - 483.1 Soils and Soil Mechanics - 641.2 Heat Transfer
DOI:10.3969/j.issn.1002-6819.2013.15.025
Database:Compendex
Compilation and indexing terms, Copyright 2013 Elsevier Inc.

Accession number:20133516679216
Title:Experiment and simulation of rolling friction characteristic of corn seed based on high-speed photography
Authors:Cui, Tao (1); Liu, Jia (1); Yang, Li (1); Zhang, Dongxing (1); Zhang, Rui (1); Lan, Wei (1)
Author affiliation:(1) College of Engineering, China Agricultural University, Beijing 100083, China
Corresponding author:Yang, L.(yl_hb86@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:15
Issue date:August 1, 2013
Publication year:2013
Pages:34-41
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:The physical properties of corn seeds, including the dimension feature, density, Poisson's rate, shear modulus, coefficient of restitution, coefficient of static fraction, and coefficient of rolling fraction are vital to the design of the precision seed-metering device and the simulation of its working process. There have been many relative studies on them, but no mature theory and accurate method to measure the coefficient of rolling friction has been developed. Due to the shape and dimension character limitation, most methods for measuring the coefficient of rolling fraction are not applicable to corn seed. Only one method based on the principle of conservation of energy gave some enlightenment on the way to achieve it. The method and principle used to obtain the coefficient of rolling friction was: A static spherical corn seed rolls from the top of an inclined rail to the end. The gravitational potential energy (U) of the seed on the top is equal to the kinetic energy at the end (E<inf>k</inf>) and the work done by the rolling friction within this distance (W<inf>fr</inf>). And the ratio of W<inf>fr</inf> and U(C<inf>f</inf>=W<inf>fr</inf>/U) has a linear relation with cotθ (θ is the angle of the inclined rail). The equation of linear regression can be fitted by changing θ eight times from 15° to 50°, the slop of the straight line just is the coefficient of rolling friction. U can be calculated by the distance of the inclined rail and θ easily, but E<inf>k</inf> needs the aid of high-speed photography technology to capture the velocity of the seed at the end. The experimental materials included several selected spherical corn seeds that were used as roll ball, an angle adjustable frame of rail, and three rails which were made of the PMMA (polymethyl methacrylate), galvanized steel, and corn seeds respectively. The main testing equipment was the Phantom v9.1 high-speed camera, which was produced by Vision Research. The frame rate used in the experiment was 1000 fps. According to the results of the experiment, the coefficient of rolling friction of corn seeds against PMMA (polymethyl methacrylate), galvanized steel, and corn seeds are known as 0.0931, 0.0531 and 0.0782 respectively. Although there were some inevitable errors caused by the materials and image processing method for getting the velocity, the results were proved to be truthful by the contrast tests about the angle of repose for corn seeds both by laboratory tests and EDEM simulation. The data measured can be used for design calculation and simulation analysis.
Number of references:29
Main heading:Tribology
Controlled terms:Computer simulation - Experiments - Friction - Galvanizing - High speed photography - Image processing - Kinetics - Polymethyl methacrylates - Seed
Uncontrolled terms:Coefficient of restitution - Coefficient of rolling frictions - Corn - EDEM - Gravitational potential energy - Image processing - methods - Precision seed-metering devices - Principle of conservation of energy
Classification code:931.1 Mechanics - 931 Classical Physics; Quantum Theory; Relativity - 901.3 Engineering Research - 821.4 Agricultural Products - 815.1.1 Organic Polymers - 742.1 Photography - 741 Light, Optics and Optical Devices - 723.5 Computer Applications - 539.3 Metal Plating
DOI:10.3969/j.issn.1002-6819.2013.15.005
Database:Compendex
Compilation and indexing terms, Copyright 2013 Elsevier Inc.

Accession number:20133516679225
Title:Scheduling model for gateway note of irrigation control system in open-air nursery
Authors:Zhang, Chaoyi (1); Zhao, Yandong (1); Zhang, Junguo (1)
Author affiliation:(1) School of Science and Technology, Beijing Forestry University, Beijing 100083, China
Corresponding author:Zhao, Y.(yandongzh@bjfu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:15
Issue date:August 1, 2013
Publication year:2013
Pages:108-115
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:In order to schedule a gateway node in wireless sensor networks, this paper proposes a new gateway node scheduling method which based on a Markov chain. The research method of this paper is: first, theory analyses one single network node's existential state, and its access behavior; second, we base on the gateway and terminal node's common status, via single node's state transition probability relation to build up system's balance equation; third, according to this balance equation, anode's scheduling is executed, as well as a description of the system working process; finally, the system's performance parameters of the scheduling method is estimated. This paper's experiment built a wireless sensor network simulated model, set up the simulation environment, constructed several gateway nodes, terminal nodes, wireless channel bandwidth, node's transmitting power, channel's signal-to-noise ratio, Rayleigh flat fading channel, etc. system parameters. Simulation analysis was conducted on this network model's bandwidth utilization and forced interrupt probability; then changing a node's signal-to-noise ratio's value, the simulation compared network capacity and blocking probability performance. Research result: first, with the increasing of a user's call rate, the bandwidth utilization also grows, because the call's increasing inevitable causes a system's collaboration gateway node to increase. When the system reaches a steady state, the bandwidth utilization is maintained at 10% to 70%. Second, the forced interrupt probability is also increased with a user's increasing call rate, on the one hand, call's increase leads a gateway node's state transition frequency to increase, on the other hand, the system tendency to a steady-state probability is also increased, thus interrupt probability increases, but the experimental results derived interrupt probability value is always less than 0.1, and this can content general quality of service (QoS) performance requirements. Third, system capacity is increased with call volumes increasing. With call increasing, the system spectrum utilization is correspondingly increased, and this will inevitably lead to the growth of system capacity. Meanwhile, when the call volume grows to a certain extent, the system capacity will gradually flatten, which is due to the system interrupt probability that will also flatten with call's increasing. The system will eventually reach a state of equilibrium finally. In order to enhance a node's efficiency in a relay system, it is necessary to do a reasonable arrangement for the access node itself working condition and between each node. According to a node's own state transition situation and interaction between each node in relay system, a relay system node scheduling model based on a discrete time Markov chain model is constructed. System equilibrium state is analyzed. The results show that, based on a relay node's rational utilization, we improve system bandwidth utilization, while keeping a lower system interrupt probability. It can improve the stability and robustness of farmland nursery irrigation sensor networks.
Number of references:30
Main heading:Sensor nodes
Controlled terms:Computer simulation - Gateways (computer networks) - Markov processes - Probability - Quality of service - Scheduling - Signal to noise ratio - Wireless sensor networks
Uncontrolled terms:Discrete time Markov chains - Equilibrium equation - Nodes - Rayleigh flat fading channel - Stability and robustness - State transition probabilities - State transitions - Steady state probabilities
Classification code:912.2 Management - 732 Control Devices - 723.5 Computer Applications - 723 Computer Software, Data Handling and Applications - 922.1 Probability Theory - 722 Computer Systems and Equipment - 717 Optical Communication - 716.1 Information Theory and Signal Processing - 716 Telecommunication; Radar, Radio and Television - 718 Telephone Systems and Related Technologies; Line Communications
DOI:10.3969/j.issn.1002-6819.2013.15.014
Database:Compendex
Compilation and indexing terms, Copyright 2013 Elsevier Inc.

Accession number:20133516679241
Title:Evaluation of cultivated land intensive use considering land quality differences
Authors:Chen, Wei (1); Wu, Qun (1)
Author affiliation:(1) College of Land Management, Nanjing Agriculture University, Nanjing 210095, China
Corresponding author:Wu, Q.(wuqun@njau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:15
Issue date:August 1, 2013
Publication year:2013
Pages:244-253
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:The aims of this paper are to illustrate the meaning and method of comparing the evaluation result of cultivated land intensive use, and to improve levels of intensive cultivated land use. We described the comparability of cultivated land intensive use, and noted that when comparing evaluation results equal consideration and correct cultivated land quality and planting structure in different districts are needed. We first calculated standard grain realizable yield in different districts based on agricultural land classification. This result can measure the quality of cultivated land. Next, we calculated standard grain actual yield in different districts by a conversion coefficient. Then we built an indicator called realizable yield utilization intensity by calculating the ratio of the standard grain actual yield and realizable yield, and this indicator can eliminate the difference on grain output because of cultivated land quality. Finally, we established an evaluation index system of cultivated land use including input intensity, use degree, production efficiency, and evaluated the level of cultivated land intensive use. Of course, the realizable yield utilization intensity was regarded as an important indicator to reflect the production efficiency. To examine this method's practical applicability, Jiangsu Province was used as an example for empirical research. The agricultural land grades in Jiangsu Province are concentrated between grade 4 to grade 8, and grade 6 is the most common, accounting for 63.77% of the land. The standard grain realizable yield is between 13606-16500 kg/h m2, higher output districts are mainly distributed in the area along the Yangtze River and Taihu Lake, and lower output districts are mainly located in the coastal areas of Suzhong and Subei, which also shows that the quality cultivated land is mainly distributed in Sunan. The standard grain actual yield is between 11665-19012 kg/h m2, and the higher output districts are mainly concentrated in the coastal areas of Suzhong and Subei, it's quite different with realizable yield from the spatial distribution point of view. The districts with higher realizable yield utilization intensity in Jiangsu Province are mainly in the areas of poor or general quality of cultivated land, and there is a lower rate in Sunan where the land has better quality. Overall, Subei has the strongest ability to achieve grain production. There are significant differences between realizable yield utilization intensity and grain yield per hectare judging from the distribution by comparison. The districts where the grain yield per hectare are similar may be very different on realizable yield utilization intensity, and vice versa. From the perspective of the province, the level of cultivated land intensive use is general, and the cultivated land use intensity in Suzhong is highest. The high intensity areas are mainly along the Yangtze River or surround the Taihu Lake and in some areas of Yancheng and Xuzhou. The distribution of cultivated land use intensity is more balanced in Nanjing, Changzhou and Huai'an, and it has a large difference in Wuxi, Suzhou and Yancheng. The level of cultivated land intensive use in Sunan is extremely unbalanced. The results of the evaluation are more accurate after eliminating the effect of cultivated land quality differences, and the indicators that we used also can eliminate the effect of planting structure differences to a certain extent. All indicators used on evaluating need to be corrected according to cultivated land quality and the planting structure of different districts, and these theories and methods will be the direction that we continue to study.
Number of references:30
Main heading:Land use
Controlled terms:Coastal zones - Grain (agricultural product) - Quality control - Rural areas - Water analysis
Uncontrolled terms:Conversion coefficients - Cultivated land intensive use - Cultivated land qualities - Evaluation index system - Evaluation results - Jiangsu - Production efficiency - Structure difference
Classification code:403 Urban and Regional Planning and Development - 471 Marine Science and Oceanography - 801 Chemistry - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.4 Agricultural Products - 913.3 Quality Assurance and Control
DOI:10.3969/j.issn.1002-6819.2013.15.030
Database:Compendex
Compilation and indexing terms, Copyright 2013 Elsevier Inc.

Accession number:20133516679212
Title:Simulation and prediction of CO<inf>2</inf> emission reductions of biogas industry in China
Authors:Yang, Yanli (1); Li, Guangquan (2); Zhang, Peidong (3)
Author affiliation:(1) Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Science, Qingdao 266101, China; (2) Department of Management, Party School of Qingdao Municipal Committee of the Communist Party of China, Qingdao 266071, China; (3) College of Environment and Safety Engineering, Qingdao University of Science and Technology, Qingdao 266042, China
Corresponding author:Zhang, P.(eeesc@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:15
Issue date:August 1, 2013
Publication year:2013
Pages:1-9
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:Biogas project is a key program to renewable energy construction in China. As a daily-consumed energy for livelihood, biogas can substitute traditional energy and provide clean energy for rural residents, which can reduce the emissions of greenhouse gases such as CO<inf>2</inf>, CH<inf>4</inf>, et al. The CO<inf>2</inf> emissions by biogas utilization are always calculated by IPCC methods, while, the CO<inf>2</inf> emissions reduction (CO<inf>2</inf> ER) by biogas utilization should be calculated by many indexes, such as living energy structure, biogas development conditions, the calorific value, used way, converting efficiency and carbon emissions coefficient of biogas and substituted fuel. It is a complicated process with large amount of manpower and material resources consumed. Therefore, it would be very useful to develop a simple and fast method to estimate CO<inf>2</inf> emissions reduction by biogas utilization. This thesis research is about the application of composite regression method in estimating the process of CO<inf>2</inf> emissions reduction by biogas utilization; the research indices include biomass resource, structure of rural living energy, and biogas development condition. The results showed that the amounts of rural household biogas digester, biogas production per household and the digester volumes of middle-scale biogas project were significant impact factors of CO<inf>2</inf> emissions reduction by biogas utilization in China. Among which, there was prominent linear relation between the amounts of rural household biogas digester and CO<inf>2</inf> emission reductions with correlation coefficient (R2) equal to 0.992 and error rate less than 5%, S function relations between biogas production per household and CO<inf>2</inf> emission reductions with correlation coefficient (R2) of 0.677 and error rate below 5%, and linear relation between the digester volumes of middle-scale biogas project and CO<inf>2</inf> emissions reduction with correlation coefficient (R2) of 0.977 and error rate less than 2%. It indicated that all the simulation results were trustworthy and useful, that was to say the composite regression model that composed by multiple linear regression and curve fitting could effectively reflect the numerical relations between CO<inf>2</inf> emissions reduction and influencing factors, also could be applied to predict the CO<inf>2</inf> ER by biogas utilization. According the 12th Five Year Development Program for Renewable Energy, the prediction results based on the method above indicated that the CO<inf>2</inf> emissions reduction of biogas utilization could reach 6.18 × 107-1.38 × 108 t in 2015. It is an effective way for keeping important station of reducing greenhouse gas emissions to strengthen research on biogas utilization technology, and promoting biogas project development in livestock farms.
Number of references:32
Main heading:Carbon dioxide
Controlled terms:Agriculture - Biogas - Emission control - Forecasting - Greenhouse gases - Linear regression - Regression analysis - Research
Uncontrolled terms:Correlation coefficient - Development programs - Emissions reduction - Material resources - Multiple linear regressions - Renewable energies - Rural household biogas - Simulation analysis
Classification code:922.2 Mathematical Statistics - 901.3 Engineering Research - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 804.2 Inorganic Compounds - 522 Gas Fuels - 451.2 Air Pollution Control - 451.1 Air Pollution Sources
DOI:10.3969/j.issn.1002-6819.2013.15.001
Database:Compendex
Compilation and indexing terms, Copyright 2013 Elsevier Inc.

Accession number:20133516679237
Title:Activated carbon production from sewage sludge employing low-oxygen flue gas
Authors:Zhao, Peitao (1); Ge, Shifu (1); Liu, Changyan (1)
Author affiliation:(1) Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, Southeast University, Nanjing 210096, China; (2) Department of Environmental Science and Technology, Tokyo Institute of Technology, Yokohama 226-8503, Japan
Corresponding author:Ge, S.(ge1962@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:15
Issue date:August 1, 2013
Publication year:2013
Pages:215-222
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:Sludge treatment and disposal have been a significant environmental problem because of the huge yield due to the high-speed urbanization and industrialization in China. Recently, in virtue of potential energy contained in organic matters of sewage sludge, thermal conversion technologies, such as pyrolysis, gasification, combustion and some high value-added products production, have been recognized as promising methods to deal with sludge aiming at energy recovering. Among them, sludge-derived activated carbon had been developed and worked as one of the most effective methods to realize the harmless sludge treatment and energy recycling simultaneously. However, the cost of the sludge-based activated carbon production was still high due to the huge amount of heat and gas required during the carbonization and activation. Therefore, this study proposed to produce the sludge-derived activated carbon with flue gases. The feasibility of exploiting low oxygen flue gas to prepare activated carbon from the sludge was investigated by focusing on the operating conditions, such as the activation method (physical activation and ZnCl<inf>2</inf> activation), activation temperature, activation time, steam content, the ratio of sludge to ZnCl<inf>2</inf> and oxygen content. The Brunauer-Emmett-Teller (BET) surface area and the adsorption value of the methylene blue and methyl orange of the derived activated carbon were taken as the indexes to evaluate its performance. The results showed that the optimal operating parameters of activation temperature, activation time and steam content were 800°C, 90 min and 34.8% respectively for the physical activation. However, the prducts were not so good comparing with the commercial products. The BET surface area, the yield of activated carbon, and the adsorption value of methylene blue and methyl orange were only 246.3 m2/g, 46%, 18.1mg/g and 14.8 mg/g respectively. It was indicated that the single use of flue gas was not sufficient for physical activation of sludge to produce activated carbon due to its low vapor content and high operation cost to support the energy demands of high activation temperature. Some other activation method should be incorporated or modified to improve the thermal efficiency of this whole process as well the performance of sludge-based activated carbon. In respect to the ZnCl<inf>2</inf> activation, the existence of oxygen can promote formation and development of the microspores of activated carbon. The BET surface area of the products produced under an oxygen content of 4%, was improved 6.82% comparing with what was prepared without oxygen. Correspondingly, the adsorption properties were improved with an increment of 2.75 times in the adsorption value of methylene blue. The optimal oxygen content was about 2%-4% for ZnCl<inf>2</inf> activation. Under the optimal condition of activation temperature 550° C, activation time 90 min and oxygen content 2%, the yield of sludge-derived activated carbon as 59%; its BET surface area and methylene blue adsorption value were the highest of 516.1m2/g and 129.8 mg/g, respectively; the pore volume, microspore volume and average pore size were 0.29 cm3/g, 0.16 cm3/g and 3.95 nm, respectively. All the data demonstrated that combination with chemical activation, the flue gas with high temperature and low oxygen content could be used as a heat resource, shielding gas and activation agent to produce activated carbon from dewatered sludge with moisture content higher than 80% directly. This study could provide a theoretical basis to lower the cost of sludge-derived activated carbon production from dewatered sewage sludge. It also provided a viable option to realize the harmless sludge treatment and cost-effective energy recycling simultaneously.
Number of references:25
Main heading:Activated carbon
Controlled terms:Adsorption - Aromatic compounds - Azo dyes - Carbonization - Chemical activation - Costs - Dewatering - Dyes - Flue gases - Optimization - Oxygen - Reactor cores - Recycling - Sewage sludge - Temperature - Vapors - Waste incineration
Uncontrolled terms:Activated carbon production - Activation temperatures - Brunauer-emmett-teller surface areas - Environmental problems - Low oxygen - Methylene blue adsorption - Physical activation - Sludge treatment and disposals
Classification code:921.5 Optimization Techniques - 911 Cost and Value Engineering; Industrial Economics - 804.1 Organic Compounds - 804 Chemical Products Generally - 803 Chemical Agents and Basic Industrial Chemicals - 802.3 Chemical Operations - 802.2 Chemical Reactions - 641.1 Thermodynamics - 621.1.1 Fission Reactor Equipment and Components - 521 Fuel Combustion and Flame Research - 452 Municipal and Industrial Wastes; Waste Treatment and Disposal
DOI:10.3969/j.issn.1002-6819.2013.15.026
Database:Compendex
Compilation and indexing terms, Copyright 2013 Elsevier Inc.

Accession number:20133516679217
Title:Simulation and experiment on efficiency characteristics of hydraulic mechanical continuously variable transmission for tractor
Authors:Wang, Guangming (1); Zhu, Sihong (1); Shi, Lixin (1); Ni, Xiangdong (1); Ruan, Wensheng (1); Ouyang, Daye (1)
Author affiliation:(1) College of Engineering, Nanjing Agricultural University, Nanjing 210031, China; (2) Jiangsu Key Laboratory for Intelligent Agricultural Equipment, Nanjing 210031, China
Corresponding author:Zhu, S.(zhusihong@njau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:15
Issue date:August 1, 2013
Publication year:2013
Pages:42-48
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:In order to estimate the efficiency level of a new kind of tractor hydraulic mechanical CVT, which would provide a theoretical reference for its structural optimization and power matching, the transmission efficiency of the CVT under partial and full load working condition were studied by the methods of both simulation and experimental calibration. First, a complete CVT transmission model was built, based on the software of SimulationX, and part of the model was modified by use of the components under a signal library so as to solve the direction problem of the power flow correctly. In order to ensure the reliability of the model, eight groups of experiments were made to calibrate some of key parameters of the model, such as viscous damping and leak coefficient of the hydraulic system. The results showed that the transmission efficiency level between the simulation model and the actual physical system were enough consistent to meet the research needs after parameter calibration, and that the maximum efficiency error is about 2.4%. Secondly, by a simulation analysis of the transmission efficiency of the CVT under full load working condition, the relationship among the transmission efficiency, the engine speed, and the load torque were studied. Furthermore, a map of transmission efficiency in partial load work condition was drawn also. Finally, this paper points out that it is important that the transmission ratio of gear pair g<inf>4</inf> before pump shaft affects the transmission efficiency. The higher the transmission ratio of the gear pair, the higher the transmission efficiency will be. But a higher transmission ratio of gear pair g<inf>4</inf> would affect both the transmission ratio distribution of each gear and the load level of motor shaft, making the hydraulic system design and component selection difficult. The conclusion in this paper shows that the transmission efficiency of the CVT is in inverse proportion to the rotational speed of the engine and in direct proportion to the torque of the engine, and the maximum transmission efficiency under the rated work condition is 81.5%; The transmission efficiency would be reduced under a negative pump displacement in the stage of HM<inf>2</inf> and HM<inf>4</inf> as well as positive pump displacement in stage of HM<inf>1</inf>, HM<inf>3</inf> because of the power cycle. In summary, the transmission efficiency of the CVT would fluctuate widely because of the complex working conditions; therefore, the relationship between the speed ratio of CVT and the rotational speed of engine must be reasonably matched in order to raise the transmission efficiency.
Number of references:30
Main heading:Electric power transmission
Controlled terms:Computer simulation - Efficiency - Engines - Experiments - Hydraulic equipment - Pumps - Tractors (agricultural) - Tractors (truck) - Transmissions - Variable speed transmissions
Uncontrolled terms:Continuously variable transmission - Efficiency characteristic - Experimental calibration - Hydraulic mechanicals - Parameter calibration - Power cycle - SimulationX - Transmission efficiency
Classification code:913.1 Production Engineering - 901.3 Engineering Research - 723.5 Computer Applications - 706.1.1 Electric Power Transmission - 663.1 Heavy Duty Motor Vehicles - 632.2 Hydraulic Equipment and Machinery - 618.2 Pumps - 612 Engines - 602.2 Mechanical Transmissions
DOI:10.3969/j.issn.1002-6819.2013.15.006
Database:Compendex
Compilation and indexing terms, Copyright 2013 Elsevier Inc.

Accession number:20133516679223
Title:Spatial structure and relationships of nitrogen balance index and protein content of grain in winter wheat
Authors:Song, Sennan (1); Song, Xiaoyu (2); Chen, Liping (2); Yang, Guijun (2); Cui, Bei (2); Jin, Xiuliang (1); Tan, Changwei (1); Guo, Wenshan (1)
Author affiliation:(1) Key Laboratory of Crop Genetics and Phyisology of Jiangsu Province/Key Laboratory of Crop Physiology, Ecology and Cultivation in Middle and Lower Reaches of Yangtse River of Ministry of Agriculture, Yangzhou University, Yangzhou 225009, China; (2) National Engineering Research Center for Information Technology in Agriculture, Beijing 100097, China; (3) Key Laboratory for Information Technologies in Agriculture, The Ministry of Agriculture, Beijing 100097, China
Corresponding author:Guo, W.(guows@yzu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:15
Issue date:August 1, 2013
Publication year:2013
Pages:91-97
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:Wheat is one of three major food crops in China, not only it is a source of calories, but also an important source of protein. With the improvement of people's living standards, the demand for high-quality food products also rose rapidly. However, the number of high-quality wheat was far from being able to meet domestic demand with largely dependence on foreign imports. The development of large-scale production of high-quality wheat became the trend of China's wheat production. Grain protein content was an important quality character in wheat, which was closely related to nitrogen absorption, transport and assimilation. Many studies showed that the status of leaf nitrogen content had significant correlation with grain protein content, thus rapid nitrogen diagnosis had great significance for guiding crop production. Multiplex is the latest hand-held optical fluorescence sensor introduced to the non-destructive measurement of various parameter representatives of plant nitrogen status. This instrument generates fluorescence in the plant tissues using light sources (LED) generating four wavelengths: UV_A (375 nm, UV); blue (450 nm, B); green (530 nm, G); and red (630 nm, R). The present research focused on the winter wheat of the National Experimental Station for Precision Agriculture of China. Based on griding sampling, nitrogen balance index (NBI) was conducted with Multiplex 3 from jointing stage to middle and late filling stages. The spatial structure between winter wheat stress fluorescent parameter nitrogen balance index (NBI) and grain protein content were analyzed using geostatistical methods, and their semivariogram was developed. Correlation coefficient was chosen as the indicator to reflect the intimate level of linear correlation between nitrogen balance index (NBI) and grain protein content. The method of contour lines of indicator value used in this article was to analyze the relationships between grain protein content and combined nitrogen balance index (NBI) obtained from four developmental stages. This method had always been used for reference in spatial relationship between one variable and several variables or that between one variable and dynamic distributions of the other one. The outcome showed that the nitrogen balance index (NBI) and the data of winter wheat grain protein content were approximately normally distributed; Variables had good regionalized variable characteristics and spatial structures; Grain protein content was significantly correlated to NBI at each developmental stage. Among them, nitrogen balance index (NBI) at the middle and late filling stage was the most sensitive variable for monitoring grain protein content with correlation coefficient (r) of 0.828; Large enough nitrogen balance index (NBI) existing for a long time was beneficial to forming higher grain protein content. Correspondingly, large enough nitrogen balance index (NBI) existing for a short time often led to forming lower grain protein content; The spatial distribution of combined nitrogen balance index (CNBI) and grain protein content had similarity, so nitrogen balance index(NBI) could be used to predict grain protein content. These results provided a theoretical basis and technical approach for crop nitrogen management and grain protein content prediction.
Number of references:21
Main heading:Grain (agricultural product)
Controlled terms:Contour measurement - Crops - Cultivation - Fluorescence - Food products - Injection molding - Light emitting diodes - Light sources - Multiplexing - Nitrogen - Normal distribution - Proteins
Uncontrolled terms:Correlation coefficient - Grain protein contents - Indicator values - Large-scale production - Nitrogen balance - Non-destructive measurement - Spatial variability - Winter wheat
Classification code:922.1 Probability Theory - 822.3 Food Products - 821.4 Agricultural Products - 821.3 Agricultural Methods - 816.1 Processing of Plastics and Other Polymers - 943.3 Special Purpose Instruments - 804.1 Organic Compounds - 741.1 Light/Optics - 718 Telephone Systems and Related Technologies; Line Communications - 717 Optical Communication - 716 Telecommunication; Radar, Radio and Television - 804 Chemical Products Generally
DOI:10.3969/j.issn.1002-6819.2013.15.012
Database:Compendex
Compilation and indexing terms, Copyright 2013 Elsevier Inc.

Accession number:20133516679244
Title:Quality kinetic model and shelf life prediction of green vegetable (Brassica rapa var. chinensis)
Authors:Xie, Jing (1); Zhang, Liping (1); Su, Hui (1); Li, Liu (1); Wu, Shengbin (1)
Author affiliation:(1) College of Food Science and Technology, Shanghai Ocean University, Shanghai 201306, China
Corresponding author:Xie, J.(jxie@shou.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:15
Issue date:August 1, 2013
Publication year:2013
Pages:271-278
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:With widely utilization of kinetic theory in the field of shelf life prediction, and the necessity of shelf life prediction of perishable leafy vegetables, two methods of shelf life prediction of green vegetable (Brassica campestris L. ssp.chinensis) were conducted through a series of experiments and validation. Reduced ascorbic acid content, chlorophyll, color parameters such as L*(lightness), b* (yellowness), δE (color difference), and sensory evaluation of green vegetable stored at 5°C, 10°C, 15°C and 20°C were determined in this experiment, then a kinetic analysis of those quality indexes and sensory score were studied. The results showed that the lower temperature at which a green vegetable was stored, the slower quality parameters change in the temperature range was concerned, in other words, the kinetics rate constant of quality change was smaller in lower temperature. Kinetic analyses were proposed that zero-order law was more appropriate than first-order reaction kinetics to describe quality determined change, and zero-order law could describe quality degradation very well except b* (yellowness) (R2&le0.84). Nonlinear fitting of reaction rate k and temperature T based on Arrhenius law was also studied, from which active energy E<inf>a</inf> of Reduced ascorbic acid content, chlorophyll, L* and δE were 68.130 kJ/mol, 57.024 kJ/mol, 46.685 kJ/mol, and 42.581 kJ/mol, respectively. As a consequence, the prediction function of green vegetable shelf life based on time, temperature, and quality parameters was obtained (R2&le0.87), from which shelf life could be calculated with different thresholds of quality indexes. A sensory score was also determined by zero-order kinetics and Arrhenius law in this paper, which was used for prediction of sensory shelf life. Sensory shelf life is 11.03, 7.11, 4.65, and 3.09 d with a score of 3.5 as the cut point for a green vegetable stored at 5, 10, 15, and 20°C, respectively, while predicted shelf life is 11.06, 7.15, 4.69, and 3.13d, by assuming final chlorophyll decreased by 36%, which was close to sensory shelf life by a small relative prediction error of 1.5%. However, because of lacking unitive standards for final shelf life in the fruit and vegetable industry, there were almost no references defining any accuracy thresholds of qualities to predict certain shelf life as close as possible with sensory shelf life. Based on above situation, shelf life resulted from Arrhenius law and linear-fitting function of dynamic final quality relied on sensory cutting point was tried in this research, the function curve of which corresponded better to the predicted curve of sensory life. The validated experiment proved that former models were a good approach to evaluate the shelf life of a green vegetable corresponding to relatively remained quality value; on the other hand, latter models could predict sensory shelf life via a quality index, of which the relative prediction error was less than 0.3 day. The overall shelf life prediction parameters can be obtained based on the combination of two models. This conclusion is expected to offer a theoretical basis for shelf life prediction of a green vegetable during transportation in circulation.
Number of references:30
Main heading:Quality control
Controlled terms:Ascorbic acid - Chlorophyll - Curve fitting - Energy storage - Enzyme kinetics - Experiments - Forecasting - Kinetic theory - Kinetics - Models - Quality assurance - Rate constants - Reaction kinetics - Vegetables
Uncontrolled terms:First order reactions - Fruit and vegetables - Prediction function - Quality degradation - Sensory evaluation - Sensory life - Shelf-life prediction - Zero order kinetics
Classification code:931.1 Mechanics - 931 Classical Physics; Quantum Theory; Relativity - 921 Mathematics - 913.3 Quality Assurance and Control - 902.1 Engineering Graphics - 901.3 Engineering Research - 821.4 Agricultural Products - 804.1 Organic Compounds - 802.2 Chemical Reactions - 801.4 Physical Chemistry - 702 Electric Batteries and Fuel Cells
DOI:10.3969/j.issn.1002-6819.2013.15.033
Database:Compendex
Compilation and indexing terms, Copyright 2013 Elsevier Inc.

Accession number:20133516679234
Title:CaO pretreatment improve biogas production performance of corn straw
Authors:Luo, Juan (1); Zhang, Yuhua (1); Chen, Ling (1); Song, Chengjun (1); Li, Xiaogang (1); Qi, Yue (1); Zhao, Lixin (1)
Author affiliation:(1) Key Laboratory of Energy Resource Utilization from Agricultural Residues, Chinese Academy of Agriculture Engineering, Beijing 100125, China; (2) Department of Environmental Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China
Corresponding author:Zhao, L.(zhaolixin5092@gmail.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:15
Issue date:August 1, 2013
Publication year:2013
Pages:192-199
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:Due to the dense materials-hemicellulose, cellulose and lignin which were difficult to degrade in the crop straws, the anaerobic decomposition couldn't decompose and utilize the crop straw quickly and efficiently. Appropriate pretreatments were needed to promote the efficiency of crop straw digestion. Lots of studies at home and abroad had shown that alkali pretreatment of crop straw had many advantages, such as having short processing time, good gas production and so on. To improve the gas production ability meanwhile reduce costs and security risks, relatively low cost and high security CaO was chosen as the pretreating agent in this study. Corn straws were pretreated by three different weight percentages (3%, 5% and 7%) of CaO retting for three different time (three days, five days and seven days) in an incubator chamber at (25±1)°C, and the effects with different conditions of CaO pretreatment on anaerobic digestion of corn straws for variation of components and anaerobic digestion performance (under temperature of (38±2)°C) were studied. A control set with untreated corn straws was also done to compare the difference with the treated ones. The experiments were set up in triplicate. The results showed that having been pretreated by CaO, the total content of hemicellulose, cellulose and lignin in corn straws was decreased, and the daily gas production and cumulative gas production got a substantial increase compared with the control. In addition, the starting time and digestion time was shortened significantly. The cellulose degradation effect of 5% and 3% of CaO with 3 days and 5% of CaO with 7 days were better in these nine pretreatments, and the degradation rates were 60.67%, 44.12% and 39.28%, respectively. The cumulative biogas production of 5% and 3% of CaO with 3 days were higher than others, and their unit dry mass gas production were 381.87mL/g and 369.00mL/g, which were 136.85% and 128.91% higher than the control. The digestion time of 80%of maximum gas production of all the treated groups was shortened by 3 to 10 days compared with the control. Most of the treated groups had significantly improved the TS and VS removal efficiency. The TS removal rates of 5% and 3% of CaO with 3 days and 3% of CaO with 5 days were 66.45%, 64.58% and 61.37%, respectively. The VS removal rates of 5% of CaO with 5 days and 3% and 5% of CaO with 3 days were improved by 10.20%, 7.95% and 7.18%, respectively. Taking daily biogas production, cumulative biogas production, anaerobic digestion time and the TS and VS removal rate into account, the weight percentage 3% of CaO with 3 days pretreatment was the best, compared with the control. The cumulative biogas production of this best treatment increased by 136.85%, and the fermentation time was shortened by 5 days. Meanwhile, the removal rates of TS increased by 21.72% and the removal rates of VS increased by 7.18%. Therefore, the weight percentage 3% of CaO with 3 days pretreatment exhibited the best effect in all of the cases, and it improved the biogas production rate and the biogas production efficiency of anaerobic digestion of corn straws effectively.
Number of references:32
Main heading:Anaerobic digestion
Controlled terms:Biogas - Cellulose - Crops - Degradation - Lignin - Straw
Uncontrolled terms:Anaerobic decomposition - Biogas production rates - Cellulose degradation - Cumulative gas productions - Digestion performance - Pre-Treatment - Removal efficiencies - Short processing time
Classification code:802.2 Chemical Reactions - 815.1.1 Organic Polymers - 821.4 Agricultural Products - 821.5 Agricultural Wastes
DOI:10.3969/j.issn.1002-6819.2013.15.023
Database:Compendex
Compilation and indexing terms, Copyright 2013 Elsevier Inc.

Accession number:20133516679246
Title:Method of information extraction of marbling image characteristic and automatic classification for beef
Authors:Zhou, Tong (1); Peng, Yankun (1)
Author affiliation:(1) National Research and Development Center for Agro-processing Equipment, College of Engineering, China Agricultural University, Beijing 100083, China
Corresponding author:Peng, Y.(ypeng@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:15
Issue date:August 1, 2013
Publication year:2013
Pages:286-293
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:Beef marbling is one of the most important indexes to assess beef quality. The grade of beef marbling is a measure of the fat distribution density in the rib-eye region. However, quality grades of beef in most of the beef slaughtering houses and enterprises depends on trainees using their visual senses or comparing to the standard sample cards in China. This manual grading method demands not only great labor but also lacks objectivity and accuracy. The objective of this research was to investigate an optimal method for grading the beef marbling based on computer vision and image processing technologies to meet the requirement of the meat industry. A practical algorithm that can be used in a beef marbling grading system is proposed in this research. The beef sample images were collected by a machine vision image acquisition system. The system consisted of an image acquisition device, computer, and image processing algorithm equipped into the self developed system software. The images of the beef samples in an aluminum plate were captured by CCD. Light intensity was regulated through a light controller, and the distance between the camera lens and the beef samples was adjusted though translation stages in the image acquisition device. Collected images were automatically stored in the computer for further image processing. First, some methods such as image denoising, background removal, and image enhancement were adopted to preprocess the image to obtain a region of interest (ROI). In this step, the image was cropped to separate the beef from the background. Then, an iteration method was used to segment the beef area, obtain the beef marbling area and fat area. The redundant fat area was removed to extract an effective rib-eye region. Ten characteristic parameters of beef marbling namely, the rate of marbling area in the rib-eye region, the number of large grain fat, medium grain fat, small grain fat, total grain fat, the density of large grain fat, medium grain fat, small grain fat, total grain fat and, the evenness degree of fat distribution in the rib-eye region can reflect the amount of marbling and its distribution. So they were used to establish principal component regression (PCR) model. The PCR model result yielded a correction coefficient (Rv) of 0.88 and a standard error of prediction (SEP) of 0.56. And the PCR model showed that the rate of the marbling area in the rib-eye region had the greatest effect on the grade of beef marbling. Fisher discriminant functions were constructed based on the PCR model results to classify the grade of beef marbling. Experimental results showed that the classification accuracy was 97.0% in the calibration set and 91.2% in the prediction set. On this basis, a software system was developed for the automatic grading of beef marbling. A corresponding hardware device was also developed, controlled by the software system for real time application. The speed and accuracy of the algorithm were verified with theoretical analysis and a practical test. Through tests, the average recognition time of each sample was 0.879 s. The results showed that the algorithm could meet the beef marbling testing and grading in precision to the practical application. Moreover, this method is of great significance for the development of an automatic classification system.
Number of references:30
Main heading:Meats
Controlled terms:Algorithms - Calibration - Computer software - Computer vision - Grading - Image acquisition - Image processing - Iterative methods - Models - Nondestructive examination - Principal component analysis
Uncontrolled terms:Automatic classification systems - Fisher discriminant function - Image acquisition systems - Image processing algorithm - Image processing technology - Principal component regression - Quality classification - Standard error of prediction
Classification code:944 Moisture, Pressure and Temperature, and Radiation Measuring Instruments - 913.3 Quality Assurance and Control - 921.6 Numerical Methods - 922.2 Mathematical Statistics - 941 Acoustical and Optical Measuring Instruments - 942 Electric and Electronic Measuring Instruments - 943 Mechanical and Miscellaneous Measuring Instruments - 902.1 Engineering Graphics - 741.2 Vision - 741 Light, Optics and Optical Devices - 723.5 Computer Applications - 723 Computer Software, Data Handling and Applications - 421 Strength of Building Materials; Mechanical Properties - 822.3 Food Products
DOI:10.3969/j.issn.1002-6819.2013.15.035
Database:Compendex
Compilation and indexing terms, Copyright 2013 Elsevier Inc.

Accession number:20133516679230
Title:Planting area extraction of winter wheat in North China Plain based on optimized N-FINDR algorithm
Authors:Hao, Lüyuan (1); Sun, Rui (1); Xie, Donghui (1); Tang, Yao (1); Wang, Yan (1)
Author affiliation:(1) State Key Laboratory of Remote Sensing Science, Beijing 100875, China; (2) School of Geography, Beijing Normal University, Beijing 100875, China; (3) Beijing Key Laboratory for Remote Sensing of Environment and Digital Cities, Beijing 100875, China
Corresponding author:Sun, R.(sunrui@bnu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:15
Issue date:August 1, 2013
Publication year:2013
Pages:153-161
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:Winter wheat is one of the main food crops in the north of China. It is significant to monitor winter wheat planting areas for China's grain policy and economic planning. The MODIS products are outstanding with the characteristics of large area coverage, frequent repeat, and free access to download. It offers a valuable application on long-term and large-area detection of winter wheat. Because of the coarse spatial resolution of MODIS products, the mixed pixels become the common problem existing in MODIS data. Therefore, it is necessary to solve the problem of mixed pixels in crop area extraction with MODIS data, In this study, we chose the Huanghuaihai Plain (including Hebei province, Shandong province, Henan province, Beijing, and Tianjin) as the study area, and used multi-temporal MODIS data in 2008 and 2009 to extract the winter wheat area with an optimized N-FINDR algorithm and linear unmixing method. In a traditional N-FINDR algorithm, all pixels in the image would be traversed to find the pixel group that can form a simplex with the maximum area. The optimized N-FINDR algorithm we used simplifies the procedure by finding the points set that can form a triangle with the maximum area in a two-dimensional plane composed by any two bands first, then the vertex of the triangle are taken as candidate endmembers, and final endmembers are obtained by traversing all the candidate endmembers. In order to find points set in a two-dimensional plane, we used the convex hull property of a polygon with rotating calipers. This optimized algorithm can improve time complexity from O(n3) to O(n2). Comparing this with national statistical data in 2009, the relative error of the extracted winter wheat planting area was less than 4% for each province. The results showed that the method we used was applicable for winter wheat area extraction on a large scale. In order to further validate the results, we selected 14 sample areas, and multi-temporal HJ-1data at same period were taken to produce the winter wheat planting map as a reference for each sample area. The validation results showed that the spatial distribution of the unmixing results agreed with the classification maps of HJ-1. The relative error of winter wheat planting area was less than 5% for 5 sample areas, and larger than 15% for 4 sample areas. The error was relatively larger for the sample areas located in the urban area and the mountain area. The error was mainly caused by the error of endmember extraction, the internal difference of the winter wheat phenology and spectra for large area, the fragmentation of crop land, and the complexity of the land surface in the mountain area.
Number of references:29
Main heading:Crops
Controlled terms:Algorithms - Extraction - Monitoring - Optimization - Pixels - Radiometers - Remote sensing - Two dimensional - Urban planning
Uncontrolled terms:Area - MODIS - N-findr - Pixel unmixing - Winter wheat
Classification code:944.7 Radiation Measuring Instruments - 944 Moisture, Pressure and Temperature, and Radiation Measuring Instruments - 943 Mechanical and Miscellaneous Measuring Instruments - 942 Electric and Electronic Measuring Instruments - 941 Acoustical and Optical Measuring Instruments - 921.5 Optimization Techniques - 921 Mathematics - 821.4 Agricultural Products - 802.3 Chemical Operations - 731.1 Control Systems - 723.5 Computer Applications - 723 Computer Software, Data Handling and Applications - 403.1 Urban Planning and Development
DOI:10.3969/j.issn.1002-6819.2013.15.019
Database:Compendex
Compilation and indexing terms, Copyright 2013 Elsevier Inc.

Accession number:20133516679224
Title:Microbiology mechanism and controlling methods for emitter clogging in the reclaimed water drip irrigation system
Authors:Li, Yunkai (1); Song, Peng (1); Zhou, Bo (1)
Author affiliation:(1) College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083, China
Corresponding author:Li, Y.(yunkai@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:15
Issue date:August 1, 2013
Publication year:2013
Pages:98-107
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:Drip irrigation is considered as the most secure and reliable irrigation method for reclaimed water due to its precision and controllability. However, reclaimed water contains a large amount of particles, nutrient salts, organics, micro-organisms and other substances, which makes the emitter clogging mechanism become more complex and also significantly increases the risk of emitter clogging. In this paper, we analyzed the biofilm structure and composition variation characteristics, basing on the significantly "S-curve " relationship between the content of bofilm components: dry weight (DW), phospholipid fatty acid (PLFAs) and extracellular polymeric substance (EPS) and emitter clogging degree, which indicated clearly that the biofilm formation was the original causes to induce emitter clogging. The progress of emitter clogging was performed as follows: microbiology in reclaimed water firstly fixed on the internal lateral surface and formed the biofilm in drip irrigation system, and then continued to absorb, to consume water and nutrient-substrate for metabolism, thus they secreted large amounts of extracellular polymeric substance (EPS), and relied on its sticky characteristics to absorb solid suspended particles and micro-organisms constantly, which induced the formation, growth, as well as shedding of biofilm, and then clogging substances continued to gather, eventually led to emitter clogging. Therefore, the biofilm formation mechanism and its influencing factors were put forward from 5 aspects, which were the flow path structure and its geometry parameters, the characteristics of the water particles, the flow shear force near the wall, the water quality of irrigated water, and the irrigation frequency. After the compositive consideration of the aspects mentioned above, a new integration technology which aimed at holding up biofilm formation in order to control emitter clogging was proposed, which also included different perspectives, including the optimization of emitter flow path structure (enhancing self-cleaning capacity of flow path and promoting biofilm shedding), the development of antibacterial materials (the inhibition of microbial adhesion), chlorination, microbial antagonistic and Quorum-Sensing (QS), micro-nano air sterilization. Finally, several urgent problems needed to be solved in the future for controlling emitter clogging in the drip irrigation using reclaimed water were put forward from 3 aspects: the biofilm inside drip emitter of hydrodynamic-coupling mechanism of microbiology; drip emitter clogging forecasts with comprehensive simulation model and its reasonable emitter threshold determining design parameters, and controlling mode after considering emitter clogging clear synergistic effect and soil long-term sustainability of quality and health.
Number of references:41
Main heading:Driers (materials)
Controlled terms:Biofilms - Computer simulation - Control - Irrigation - Microorganisms - Nutrients - Phospholipids - Polymers - Quality control - Reclamation - Shear flow - Water quality
Uncontrolled terms:Clogging - Drip irrigation - Extracellular polymeric substances - Inhibition of microbial adhesion - Long-term sustainability - Phospholipid fatty acids - Re-claimed water - Solid suspended particles
Classification code:913.3 Quality Assurance and Control - 732 Control Devices - 803 Chemical Agents and Basic Industrial Chemicals - 804.1 Organic Compounds - 815.1 Polymeric Materials - 821.2 Agricultural Chemicals - 821.3 Agricultural Methods - 731 Automatic Control Principles and Applications - 462.5 Biomaterials (including synthetics) - 461.9 Biology - 453.2 Water Pollution Control - 452.4 Industrial Wastes Treatment and Disposal - 421 Strength of Building Materials; Mechanical Properties - 723.5 Computer Applications
DOI:10.3969/j.issn.1002-6819.2013.15.013
Database:Compendex
Compilation and indexing terms, Copyright 2013 Elsevier Inc.

Accession number:20133516679215
Title:Optimization and test of roller radius of ring die straw forming machine
Authors:Wang, Chunhua (1); Song, Chao (1); Zhu, Tianlong (1); Wang, Chuan (1)
Author affiliation:(1) College of Mechanical Engineering, Liaoning Technical University, Fuxin 123000, China
Corresponding author:Wang, C.(lgdxbl203@sina.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:15
Issue date:August 1, 2013
Publication year:2013
Pages:26-33
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:Biomass briquette technology is one of the ways of biomass energy conversion. A straw briquetting machine is a main machine of straw biomass briquette. At present, the ring die straw briquetting machine efficiency is low, In order to solve the problems of low efficiency of the ring die straw forming machine when briquetting biomass, the paper makes an analysis for the rolled compaction process of the pressure roller. Research for increasing the working efficiency of a ring die straw forming machine shows that the ratio of forage again pressed into the distance and pressure roller drive torque ratio size is related to the working efficiency of a ring die straw forming machine. In the mechanical analysis of rolled compacting biomass by the pressure roller, the paper establishes its mechanical model and mathematical model., The paper first establishes a mathematic mold of working efficiency of ring die straw forming machine and the ratio of the pressure roller, setting the ratio of circular mold at 275 mm, arranges different values of the pressure roller evenly(10 mm~250 mm,step value: 5mm) and different friction coefficients between biomass and the pressure roller, and then calculates and maps curves of the efficiency of a ring die straw forming machine and the ratio of the pressure roller and circular's mold radius. The experiment takes corn stalk as the object of study. Effects of moisture content of biomass at home and abroad as well as the biomass particle size on machine efficiency and biomass quality have been studied a lot. Considering the grass block (dry and wet) each index power density, the maximum extrusion force, press consumption, productivity, to determine the water content is about 29%, the maximum extrusion force is small, low power consumption, suitable density, high productivity. The maximum extrusion force of die hole is f = 11590N-1. and the best moisture is 29%. due to the different coefficient of the sliding friction of different particle size of corn straw and roller. With the increase of straw particle size, the sliding friction coefficient decreases gradually, ability of corn straw automatic continuous bite worse, size from 10 mm to 30 mm, the sliding friction coefficient varied from 0.60 to 0.46, in the grinding process of corn straw size more production efficiency is high, the selection of the particle size is 30 mm.The experiment mainly chooses four coefficients of sliding friction 0.45, 0.5, 0.55, and 0.6 to analyse. die hole diameter is 32 mm. With the increase of pressure roller radius, 4 different friction coefficient curves showed the same change trend, In the drawing of the image can be seen in the curve first increased with pressure roller radius, roller radius in 185 mm with the increase of pressure roller radius decreasing. According to the curves, when the radius of the pressure roller is 105 mm, compression distance to biomass on one stoke of the pressure roller reaches its greatest, and ring die straw forming machine has the best t working efficiency, at the same time, and obtains the optimal ratio of the pressure roller and circular's mold radius, which is 0.40, greatly improving the annular straw briquetting machine work efficiency As a ring die straw forming machine reaches its greatest efficiency, the ratio of the pressure roller and circular's mold radius is never affected by the friction coefficients between forage and the pressure roller. But the quality of formation of biomass will gradually decrease when the friction coefficient gets smaller. The optimal ratio can meet automatical biting condition: γ=0.35, μ=0.46. With the grain size of 30 mm, moisture content of corn straw particles 29% as test material, different size of the roller radius for test, the biomass productivity reached the highest value ratio of 2.28 t/h roller radius and die radius was 0.40. Eventually, the paper obtained the optimal ratio of the pressure roller and circular's mold radius, which is 0.40, thus providing the basis for the selection of the pressure roller's radius.
Number of references:32
Main heading:Rollers (machine components)
Controlled terms:Biomass - Briquets - Briquetting - Dies - Efficiency - Energy conversion - Experiments - Extrusion - Friction - Grain size and shape - Machining - Mathematical models - Metal forming machines - Moisture determination - Molds - Optimization - Particle size - Productivity
Uncontrolled terms:Biomass productivity - Different particle sizes - Forming machine - Friction coefficients - Low-power consumption - Production efficiency - Roller radius - Sliding friction coefficient
Classification code:801.4 Physical Chemistry - 901.3 Engineering Research - 913.1 Production Engineering - 944.2 Moisture Measurements - 921 Mathematics - 931.1 Mechanics - 931.2 Physical Properties of Gases, Liquids and Solids - 921.5 Optimization Techniques - 604.2 Machining Operations - 603.2 Machine Tool Accessories - 524 Solid Fuels - 525.1 Energy Resources and Renewable Energy Issues - 525.5 Energy Conversion Issues - 535.2.1 Metal Forming Machines - 535.2.2 Metal Forming Practice - 601.2 Machine Components
DOI:10.3969/j.issn.1002-6819.2013.15.004
Database:Compendex
Compilation and indexing terms, Copyright 2013 Elsevier Inc.

Accession number:20133516679245
Title:Transmission hyperspectral detection method for weight and black heart of potato
Authors:Gao, Hailong (1); Li, Xiaoyu (1); Xu, Senmiao (1); Huang, Tao (1); Tao, Hailong (1); Li, Xiaojin (1)
Author affiliation:(1) College of Engineering, Huazhong Agricultural University, Wuhan 430070, China
Corresponding author:Li, X.(lixiaoyu@mail.hzau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:15
Issue date:August 1, 2013
Publication year:2013
Pages:279-285
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:Potatos are one of the world's major food crops. It not only has medicinal value and food value, but also has industrial value. The quality of potatos is directly related to their commodity level, benefits, and market competitiveness. Therefore, its quality testing is an important part of potato processing. Currently, common non-destructive testing techniques (near infrared spectroscopy and machine vision technology) are unable to achieve simultaneous detection of a potato's internal and external quality. Transmission hyperspectral imaging technology has some penetrating ability, when the light passes through the agricultural products, spectral and image of hyperspectral imaging data will change according to the differences in their internal characteristics. Therefore, the transmission hyperspectral imaging technology not only can detect the internal quality of agricultural products, but also can detect some external qualities. Since the single detection technology cannot simultaneously detect the internal and external quality of potatoes, the internal black heart and external weight of potatoes are detected by the transmission hyperspectral imaging technology and fusing spectrum and image information. In this study, 266 hyperspectral images (400-1000 nm) were collected by the transmission hyperspectral imaging system, and then the spectrum and the image information were extracted. Using a Monte Carlo cross-validation method to exclude the data of two abnormal black heart samples, and variable selection methods of uninformative variable elimination (UVE) and successive projections algorithm (SPA) were used to do the variable selection for the spectrum of the black heart sample. The eventual adoption of 9 spectral variables were used to establish the detection model of black heart by a partial least squares discriminant analysis (PLS-DA); variable selection methods of competitive adaptive reweighed sampling (CARS) and successive projections algorithm (SPA) were used to do variable selection for a weight testing sample spectrum, the eventual adoption of 9 variables established a detection model of weight testing by partial least-squares regression (PLS); the Area information of transmission hyperspectral image was extracted, which combined with the 9 spectral variables to set up an PLS model for weight detection based on spectral-image information. The research demonstrates that the accurate recognition rate of black heart is 100%, and the minimum shoddy area which could be identified was 1.88 cm2. The performance of the weight detection model based on the spectrum-image (10 variables) is much better than the one based on the spectrum (9 variables), the prediction correlation coefficient (Rp) was 0.99, and the forecast root mean square error (RMSEP) was 10.88.The results indicate that using the transmission hyperspectral imaging technology with the fusion of image and spectrum information to detect potatoes'internal black heart and external weight simultaneously is feasible.
Number of references:28
Main heading:Heart
Controlled terms:Agricultural products - Algorithms - Computer vision - Image processing - Imaging techniques - Independent component analysis - Least squares approximations - Mean square error - Monte Carlo methods - Near infrared spectroscopy - Nondestructive examination - Spectrum analysis
Uncontrolled terms:External quality - Hyperspectral imaging technologies - Partial least squares discriminant analyses (PLSDA) - Partial least-squares regression - Potatoes - Successive projections algorithms (SPA) - Transmission spectrums - Uninformative variable eliminations
Classification code:922.2 Mathematical Statistics - 921.6 Numerical Methods - 921 Mathematics - 821.4 Agricultural Products - 801 Chemistry - 746 Imaging Techniques - 741.2 Vision - 741 Light, Optics and Optical Devices - 723 Computer Software, Data Handling and Applications - 461.2 Biological Materials and Tissue Engineering - 421 Strength of Building Materials; Mechanical Properties
DOI:10.3969/j.issn.1002-6819.2013.15.034
Database:Compendex
Compilation and indexing terms, Copyright 2013 Elsevier Inc.

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