<RECORD 1>
Accession number:20162002392083
Title:Nondestructive measurement of moisture content of peanut kernels based on concentric cylindrical capacitance
Authors:Zhao, Liqing (1, 2); Shang, Shuqi (2); Gao, Lianxing (1); Hu, Xiuhui (2); Yin, Yuanyuan (2); Gong, Linong (2)
Author affiliation:(1) College of Engineering, Shenyang Agricultural University, Shenyang, China; (2) College of Mechanical and Electrical Engineering, Qingdao Agricultural University, Qingdao, China
Corresponding author:Gao, Lianxing(lianxing_gao@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:212-218
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Peanut is an important oil and economic crop, and also a major export product in China. Peanut industries manufacture many types of peanut-based products for human's life. The moisture content of peanuts is in the range of 45%-50% when peanuts are freshly harvested, and the moisture content has to be below 10.5% in storage. High moisture content in peanut kernels can make them moldy, which mainly produces the toxic aflatoxins and causes huge waste and jeopardizes human's health. Therefore it is necessary to keep proper moisture content in every treating process of peanuts. The detection of moisture content plays an important role in harvesting, drying, storage and trade of peanuts. Although the traditional oven-drying method has high precision, it is cumbersome and takes a lot of time. In addition to the oven-drying method and the microwave method, the near infrared method and the capacitance method are also common methods of moisture content detection. Comparing to other methods, the capacitance method has advantages of simple structure and low cost. In order to develop a rapid and accurate moisture content detection method for peanut kernels, the capacitance method was adopted to measure moisture content by using dielectric properties of grain. A peanut kernel moisture content detector was designed; MSP430 single chip microcomputer was taken as its control chip, and cylindrical capacitance sensor, temperature sensor and weighing sensor were used to detect capacitance, temperature and bulk density of peanut kernels respectively. Capacitance was converted to frequency through the signal detection and conditioning circuit, and frequency was detected when the capacitance sensor was empty or full of peanut kernels samples. The difference frequency values were processed and calculated by the single chip microcomputer. Subsequently an equation of measured difference frequency, temperature and moisture content values was established by the oven-drying method, and the detection results were displayed on the liquid crystal display (LCD) screen and all detected data were saved in a memory card. To investigate the influence of moisture content, temperature and bulk density on difference frequency, the tests were conducted at 7 moisture content levels from 6.4% to 18.2% and 4 temperature levels from 10 to 40. The results indicated that there was a good linear relationship between moisture content and difference frequency, as the difference frequency values increased with the elevation of moisture content, temperature and bulk density. In the test, because peanut kernels fell into the capacitance sensor from fixed height, the bulk density was not changed, which caused little effect on measurement. Therefore a mathematical model of 3 parameters of moisture content, temperature and difference frequency was established based on the MATLAB 7.10.0 software by using a multi-variation binomial regression method. Linear model, pure quadratic model, interaction model and full quadratic model were compared and the results suggested that the full quadratic model described the relationship of moisture content, temperature and difference frequency more accurately. In the validation test, the results showed the absolute value of relative error measured by the moisture content detector was below 0.5%. Therefore the feasibility of detecting the moisture content of peanut kernels based on the capacitance method was verified, as well as the reliability of the multi-linear regression model. This investigation provides a useful tool for the rapid and nondestructive measurement of moisture content for peanut kernels. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Moisture
Controlled terms:Capacitance - Computers - Dielectric properties - Digital storage - Drying - Infrared devices - Infrared drying - Linear regression - Liquid crystal displays - MATLAB - Microcomputers - Moisture determination - Nondestructive examination - Oilseeds - Ovens - Regression analysis - Temperature
Uncontrolled terms:Bulk density - Liquid crystal display screens - Moisture content values - Multi-linear regression - Non-destructive measurement - Peanut kernel - Single chip microcomputers - Temperature compensation
Classification code:641.1 Thermodynamics - 701.1 Electricity: Basic Concepts and Phenomena - 722.1 Data Storage, Equipment and Techniques - 722.4 Digital Computers and Systems - 821.4 Agricultural Products - 921 Mathematics - 922.2 Mathematical Statistics - 931.2 Physical Properties of Gases, Liquids and Solids - 944.2 Moisture Measurements
DOI:10.11975/j.issn.1002-6819.2016.09.030
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
<RECORD 2>
Accession number:20162002392070
Title:Characterization of soil aggregate microstructure under different revegetation types using micro-computed tomography
Authors:Zhao, Dong (1, 4); Xu, Mingxiang (1, 2); Liu, Guobin (1); Zhang, Rongrong (2); Tuo, Dengfeng (3)
Author affiliation:(1) State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling, China; (2) College of Natural Resources and Environment, Northwest A & F University, Yangling, China; (3) Institute of Soil and Water Conservation, Northwest A&F University, Yangling, China; (4) College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
Corresponding author:Liu, Guobin(gbliu@ms.iswc.ac.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:123-129
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Soil aggregate microstructure is a crucial factor that affects various soil physiochemical and biological processes. Vegetation restoration is expected to improve soil microstructure, yet little is known about the extent of changes in soil aggregate microstructure. X-ray micro-computed tomography (micro-CT), in combination with image analysis techniques, can provide three-dimensional (3D) data of porosity and pore size distribution, and is therefore useful to better investigate the 3D microstructure of soil aggregates. The objective of this study was to evaluate the impacts of different revegetation types (artificial shrubland, natural grassland and slope cropland) on the aggregate microstructure on the Loess Plateau using X-ray micro-CT measurements. The sampling sites were all located close to the top of the loess mounds with little difference in terms of aspect, slope gradient, elevation, and previous farming practices. An area of 100 m ×100 m was randomly selected for each site and within this area 3 20 m × 20 m plots were selected for sampling. Three samples of soil aggregate (3-5 mm) within 0.20 m soil profiles selected from each site were scanned at 3.25 μm voxel resolution with SSRF (Shanghai Synchrotron Radiation Facility). Segmentation of the grayscale slices was performed using automatic Otsu thresholding algorithm, and the threshold values were carefully chosen based on visual observation. To avoid edge effects, the sub-volume of 500 × 500 × 500 voxel (1.625 mm × 1.625 mm × 1.625 mm) was extracted for further analyses, representing an inscribed cube of the aggregate. The 3D pore structure was constructed and quantified using the digital image analysis software ImageJ. Aggregate water stability and other soil properties were also evaluated. Results showed that soil organic carbon and aggregate water stability were significantly increased, while soil bulk density was significantly decreased under both revegetation types (artificial shrubland and natural grassland). The surface soil texture showed no significant difference for different revegetation types. The total porosity of the aggregates was increased by approximately 60% and 20%, but the pore number was decreased by about 62% and 68% respectively in the artificial shrubland and the natural grassland compared to the slope cropland. Vegetation restoration affected the pore distribution of soil aggregates, which on the one hand promoted the proportion of >100 μm large pores and on the other hand decreased that of the pore size classes of <30 and 30-75 μm. Revegetation significantly changed the pore shape of soil aggregates, with a shift from regular and irregular pores to elongated pores. The fraction of elongated pores was dominant in all soil samples (on average 81%), and the order was artificial shrubland > natural grassland > cropland. The 3D fractal dimension and connectivity of soil aggregates showed a higher value in both revegetation types, suggesting pore system was improved after vegetation restoration. The total porosity, macro-porosity (>100 μm), fraction of elongated pores, fractal dimension and pore connectivity were significantly higher in the artificial shrubland aggregates compared to the natural grassland aggregates, indicating that the soil structure of the artificial shrubland was more developed than that of the natural grassland. That may be due to a higher organic carbon content and more developed root system under the artificial shrubland. The 3D fractal dimension of soil aggregates showed a curvilinear positive correlation with total porosity, however, Euler number showed a curvilinear negative correlation with total porosity. The fractal dimension and connectivity showed a high sensitivity to the change of soil structure, and thus could be used for evaluating the soil quality during the revegetation in this region. These results from this study can help understand the soil processes and may be used to quantify the effects of management on environment. With the development of computed tomography, it should be widely used to investigate the soil microstructure in more regions; and moreover the process mechanisms of soil aggregates also require further investigation. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Soil surveys
Controlled terms:Aggregates - Computerized tomography - Fractal dimension - Fractals - Image analysis - Image processing - Landforms - Microstructure - Organic carbon - Pore size - Porosity - Restoration - Revegetation - Sediments - Soil conservation - Soils - Synchrotron radiation - Tomography - Vegetation
Uncontrolled terms:Digital image analysis - Image analysis techniques - Loess Plateau - Micro CT - Microcomputed tomography - Organic carbon contents - Shanghai synchrotron radiation facilities - X ray micro-computed tomography
Classification code:406 Highway Engineering - 442.2 Land Reclamation - 481.1 Geology - 483 Soil Mechanics and Foundations - 483.1 Soils and Soil Mechanics - 723.5 Computer Applications - 746 Imaging Techniques - 804.1 Organic Compounds - 921 Mathematics - 931.2 Physical Properties of Gases, Liquids and Solids - 932.1.1 Particle Accelerators - 951 Materials Science
DOI:10.11975/j.issn.1002-6819.2016.09.017
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
<RECORD 3>
Accession number:20162002392077
Title:Extracting land cover types in western Jilin based on multi-temporal remote sensing data
Authors:Li, Xiaodong (1, 2); Jiang, Qigang (1)
Author affiliation:(1) College of GeoExploration Science and Technology, Jilin University, Changchun, China; (2) Baicheng Normal College, Baicheng, China
Corresponding author:Jiang, Qigang(sky_0013@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:173-178
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Recently, it's still difficult to entirely replace the artificial visual interpretation for the computer automatic classification, which is used to extract land cover types' information from the remote sensing imagery, because the automatic method needs more efforts to improve the precision of the classification results. Furthermore, this problem has become the key joint of the automatic classification extraction. How to extract land cover types' information in western area of Jilin, is one of the important problems, and the confused land cover types needs to be distinguished. The aim of this study is to deepen the application of remote sensing classification method that is used to extract land cover information automatically and quickly from the satellite imagery. The western area of Jilin is selected as the main research area. A new total solution to extract land cover information, based on the spatial variation theory, has been designed for the convenient automatic classification with the remote sensing technology. The remote sensing classification scheme is carried out by coding the R language algorithm and operating the remote sensing software ERDAS platform. The land cover types in Zhenlai County in the western area of Jilin, have been extracted and monitored through the combined utilization of 4 indices, including semivariance value of normalized difference vegetation index (NDVI) dataset, local variance of image texture, modified soil-adjusted vegetation index and normalized difference water index, which have significant meaning for the land cover types in the transition zone between cropping area and nomadic area. These variances have definite physical meaning (including vegetation, water, and soil drought conditions), so that the phenological information was used to build a multi-dimensional feature space classification data set. The results indicated that: 1) A total of 11 land cover types are extracted, using the multi-temporal remote sensing information to build a multidimensional classification characteristics data set based on the Landsat 8 data. The overall classification accuracy of the algorithm is 95.50%; the Kappa coefficient of classification is 0.9504. The automatic extracting approach implemented obtains a comparatively ideal classification result; 2) The introduction of 3 characteristic variables of the classification in the scheme significantly improves the separability of the confused land cover types. Considering the vegetation classification, the vegetation growth information has practical life-activity significance, and is a real-time dynamic method for the vegetation change monitoring; 3) Improving the land cover classification accuracy is not to introduce more characteristic parameters of the classification, but to effectively combine multiple appropriate classification variables. The new method can broaden the application vision and the scope of the ecological remote sensing investigation of surface vegetation. Moreover, the introduction of new variables not only makes the macro monitoring more convenient, but also improves the accuracy of classification of remote sensing interpretation. It's noted that the extracted classification has obvious regional feature, and the regional feature is consistent with the farming cultivation characteristics on the Northeast Plain. In a word, the results can provide a credible approach and valuable example for extracting and monitoring land cover type in farming-pastoral transitional zone. It is feasible to use the spatial variation theory to extract and monitor land cover type by combining the several evaluation indices. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:16
Main heading:Classification (of information)
Controlled terms:Algorithms - Automatic indexing - Data mining - Forestry - Image reconstruction - Image texture - Remote sensing - Satellite imagery - Space optics - Vegetation
Uncontrolled terms:Land-cover types - Multi-dimensional classifications - Multi-temporal remote sensing - Normalized difference vegetation index - Normalized difference water index - Phenological information - Remote sensing interpretation - Western Jilin
Classification code:655.2 Satellites - 656.1 Space Flight - 716.1 Information Theory and Signal Processing - 723.2 Data Processing and Image Processing - 723.5 Computer Applications
DOI:10.11975/j.issn.1002-6819.2016.09.024
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
<RECORD 4>
Accession number:20162002392078
Title:Evaluation and analysis of heavy metals in vegetable field of Beijing
Authors:Suo, Linna (1); Liu, Baocun (1); Zhao, Tongke (1); Wu, Qiong (1); An, Zhizhuang (1)
Author affiliation:(1) Institute of Plant Nutrition and Resources, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
Corresponding author:An, Zhizhuang(baafsyzs@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:179-186
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Over the last decades, large-scale greenhouse vegetable production has been widely developed in the suburban areas of Beijing. However, a lot of agricultural production materials (such as fertilizers, organic fertilizers, pesticides, and agricultural films) are always input into greenhouse conditions to achieve high vegetable production. Therefore, soil contamination problem especially heavy metal pollution has emerged gradually. Due to the direct or indirect threat to food safety, human health, and its detrimental effects on ecosystem, heavy metal pollution in fields has become an important frontier in environmental research and drawn more and more attentions. There have been several studies on the quality of the agricultural soils, concerning about soil fertility, soil enzyme activities, and available microelements. However, there is little discussion on the present heavy metal condition of vegetable field in Beijing. A survey was conducted to analyze and assess the soil heavy metals' environmental quality of vegetable field in Beijing. During 2011-2013, a total of 319 topsoil (0-20 cm depth) samples were collected from the main vegetable planting areas in Beijing, which included 8 districts. The sampling sites were randomly collected based on the distribution of local agricultural land use. Soil pH value ranged from 6.11 to 9.03. Most of the soil samples were alkaline, and 80.50% of the samples had the pH value of above 7.50. The mean values of the heavy metal concentrations were (0.24±0.28), (75.71±47.21), (7.71±4.50), (0.08±0.06), (23.80±6.09), (23.48±3.91), (24.96±4.68), and (89.92±27.96) mg/kg for cadmium (Cd), chromium (Cr), arsenic (As), mercury (Hg), lead (Pb), nickel (Ni), copper (Cu), and zinc (Zn), respectively. In addition, the background values of heavy metals in Beijing were also listed for reference (0.12, 29.80, 7.09, 0.07, 24.60, 26.80, 18.70 and 57.50 mg/kg for Cd, Cr, As, Hg, Pb, Ni, Cu and Zn). The concentrations of Zn, Cu, As and Pb, especially those of Cr and Cd in the study area exceeded the background values in Beijing. The coefficient of variation (CV) was calculated by standard deviation divided by mean of each kind of heavy metal. A modified version of the ranking for CV suggested by Phil-Eze (2010) was used in this study: CV≤20%, low variability; 21%≤CV≤50%, moderate variability; 51%≤CV≤100%, high variability; CV≥100%, exceptionally high variability. The CV values varied from 16.75% (for Ni) to 114.11% (for Cd), which decreased in the order of Cd > Hg > Cr > As > Zn > Pb > Cu > Ni. The CV values of Cd, Hg, Cr and As (from 114.11% to 58.37%) were extremely higher than the other elements, suggesting that they had the greatest variation among the studied metals and showed a higher possibility of being influenced by extrinsic factors, such as human activities, agronomic practices, automobile exhaust, and deposition of aerosol particle. Among the studied districts, soil Cd and Cr were enriched in Daxing, Changping, Miyun, Yanqing, Fangshan, Shunyi and Tongzhou. According to Environmental quality standard for soils and Farmland environmental quality evaluation standards for edible agricultural products, the data were analyzed with the single factor index and Nemerow index for the soil environmental quality assessments. Single factor analysis indicated that in some areas (such as Shunyi and Fangshan District), the soil Cd concentrations reached the limited value (0.40 mg/kg) of Farmland environmental quality evaluation standards for edible agricultural products, but below the grade standard (0.60 mg/kg) of soil environmental quality assessment classification. Average single pollution index of Cd, Cr, Cu and Zn in the investigation area was between 0.7 and 1.0, which was at the "relatively clean (alert)" level. Average Nemerow index of the investigation area was 0.65, which reached the I grade standard (≤0.7) of soil environmental quality assessment classification. It is concluded that the soil heavy metals' environment quality of vegetable field in Beijing is relatively safe, but the potential ecological risk of soil Cd accumulated in greenhouse vegetable field should be paid more attentions. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Soil pollution
Controlled terms:Agricultural products - Agriculture - Alkalinity - Cadmium - Chemical contamination - Chromium - Copper - Ecology - Farms - Fertilizers - Films - Greenhouses - Health risks - Heavy metals - Land use - Lead - Mercury (metal) - Metal analysis - Nickel - pH - Pollution - Quality control - Quality management - Soils - Statistical methods - Vegetables - Woolen and worsted yarn - Zinc
Uncontrolled terms:Agricultural productions - Assessment - Beijing - Environmental quality assessment - Environmental quality standards - Heavy metal concentration - Potential ecological risk - Vegetable Field
Classification code:403 Urban and Regional Planning and Development - 454.3 Ecology and Ecosystems - 461.7 Health Care - 483.1 Soils and Soil Mechanics - 531 Metallurgy and Metallography - 543.1 Chromium and Alloys - 544.1 Copper - 546.1 Lead and Alloys - 546.3 Zinc and Alloys - 548.1 Nickel - 549.3 Nonferrous Metals and Alloys excluding Alkali and Alkaline Earth Metals - 801.1 Chemistry, General - 804 Chemical Products Generally - 819.1 Natural Fibers - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 822.3 Food Products - 912.2 Management - 913.3 Quality Assurance and Control - 922.2 Mathematical Statistics
DOI:10.11975/j.issn.1002-6819.2016.09.025
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
<RECORD 5>
Accession number:20162002392075
Title:Remote sensing estimation of winter wheat leaf nitrogen content based on GF-1 satellite data
Authors:Li, Fenling (1, 2); Chang, Qingrui (1, 2); Shen, Jian (1); Wang, Li (1)
Author affiliation:(1) College of Natural Resources and Environment, Northwest A&F University, Yangling, China; (2) Key Laboratory of Plant Nutrition and the Agri-Environment in Northwest China, Ministry of Agriculture, Yangling, China
Corresponding author:Chang, Qingrui(changqr@nwsuaf.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:157-164
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Nitrogen is a major element for plant growth and yield formation in agronomic crops. Crop nitrogen content estimation by remote sensing technique has been being a topic research in remote sensing monitoring of agricultural parameters. Hyper-spectral remote sensing with wealth of spectral information has been widely used in crop physiological and biochemical information extraction. It provides theoretical basis for estimating crop biochemical parameters based on multi-spectral satellite data. In terms of multi-spectral satellite remote sensing, spectral reflectances and spectral indices are effective ways to establish estimation models of biochemical parameters, but which bands and spectral indices are more effective and reliable for leaf nitrogen concentration monitoring in winter wheat is still debatable. In this article, ground-based canopy spectral reflectance and leaf nitrogen content (LNC) of winter wheat were measured from field and plot experiments including varied nitrogen fertilization levels and winter wheat varieties across the whole growth stages. Multi-spectral broadband reflectance was simulated by using the measured hyper-spectral reflectance and spectral response functions of multi-spectral camera of GF-1 satellite with a spatial resolution of 8 m, and then, they were used for the establishment of spectral index (SI). Eight spectral indices significantly correlated with LNC at the 0.01 probability level were used to construct the LNC estimation models in a linear, quadratic polynomial and exponential regression model respectively. Considering the influence factors in evaluating the efficiency of the SI-LNC model, i.e., the stability of the SI to other perturbing factors, the sensitivity of the SI to a unit change of LNC, and the dynamic range of the SI, the improved sensitivity index was proposed based on the NE and T<inf>VI</inf>index models. The optimal LNC estimation model was given according to the sensitivity and accuracy analysis, and the model was used to inverse the LNC in greenup growth period based on the GF-1 satellite image. The results showed that: 1) The simulated multi-spectral reflectance was highly correlated with the spectral reflectance from remote sensing images in visible and near infrared bands. They were consistent with each other keeping a correlation coefficient of greater than 0.95. It was concluded that the simulated broadband SI considering the spectral response function could be used to analyze the quantitative relationship with leaf nitrogen in both different growth periods and whole growth stage. 2) The SI based on the simulated spectral reflectance was significantly related with the LNC at 0.01 probability level with the correlation coefficient of greater than 0.6. A different pattern of the best combinations was found for 6 two-band spectral indices. The selection of 610-690 nm paired with 750-900 nm was the most effective two-band combination in RVI index, which was also the center wavelengths of the red and near infrared bands for GF-1 satellite data. 3) The sensitivity analysis indicated that all the regression models of selected SI passed the significance test at 0.01 probability level. The TCARI/OSAVI and RVI indices linearly related with LNC implied a stable response to the LNC changes. The first-order differentials of RVI and TCARI/OSAVI with respect to LNC were 9.44 and 3.08, and the sensitivity indices were 0.0671 and 0.1979 respectively. The RVI index was regarded as the most suitable index for LNC estimation. 4) The TCARI/OSAVI and RVI indices performed well in accuracy test, and the RVI index was more excellent in remote sensing mapping based on the GF-1 satellite image. Taking all factors into consideration, we believed the model based on the RVI index was optimal for LNC estimation with the determination coefficient of 0.6. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Remote sensing
Controlled terms:Crops - Image reconstruction - Infrared devices - Nitrogen - Optical waveguides - Parameter estimation - Probability - Reflection - Regression analysis - Satellites - Sensitivity analysis
Uncontrolled terms:Canopy spectral reflectance - Determination coefficients - GF-1 - Nitrogen fertilization level - Remote sensing estimations - Remote sensing techniques - Spectral response functions - Winter wheat
Classification code:655.2 Satellites - 714.3 Waveguides - 804 Chemical Products Generally - 821.4 Agricultural Products - 921 Mathematics - 922.1 Probability Theory - 922.2 Mathematical Statistics
DOI:10.11975/j.issn.1002-6819.2016.09.022
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
<RECORD 6>
Accession number:20162002392063
Title:Optimization for response time of solenoid valve through response surface methodology
Authors:Jiang, Huanyu (1); Zhang, Lijun (1); Zhou, Mingchuan (1); Shi, Weinan (1)
Author affiliation:(1) College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:67-73
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Solenoid valve driven by PWM (pulse width modulation) control signal is used as interface between electronic control and fluid flow in precision spraying, the response time of which has huge impact on the performance of precise spray system. Longer response time would reduce the accuracy of spraying and increase the overuse of chemical. A modified PWM technology (with much higher frequency for controlling the holding current) was applied and 3 parameters of PWM control signal containing driving voltage, delayed time and duty cycle were optimized by RSM (response surface methodology) to shorten the response time, which was composed of opening response time and closing response time. The optimization of parameters was carried out through the BBD (Box-Behnken design) with 3 factors and 3 levels. The critical factors (and their values) selected for the research were driving voltage (10, 12 and 14 V), delayed time (15, 40 and 65 ms) and duty cycle (5%, 15% and 25%). In order to better explore the influence of factors on each response phase of solenoid valve, the opening response time, closing response time and response time were discussed separately. The experiment was performed on an optimization experiment platform which consisted of human-machine control module, pressure supply module and PWM module. On the platform, the wave data that could reflect the relation between voltage of PWM control signal and instantaneous spray pressure near the nozzle were acquired through digital oscilloscope and then processed by Kalman filter. By analyzing the wave data, the opening and closing response time of solenoid valve with different parameters were calculated. After 15 runs of experiments under different parameter conditions, the mathematical regression models for the opening response time, closing response time and response time were built, respectively. Then the models were tested by the analysis of variance and statistical parameters of the model for response. The test indicated that the relations between response variables and independent variables were significant and the regression models were thought to be appropriate. Through the analyses of 3 tested models and response surfaces showing the effects of process parameters on response time, the effects of driving voltage, delayed time and duty cycle of PWM signal on 3 kinds of response time of solenoid valve were obtained. Firstly, the voltage had a significant effect on all response models and a positive effect on reducing response time. Secondly, the delayed time had a negative effect on reducing response time and the effect it brought was not so significant; in addition, longer delayed time could accelerate the opening phase but detain the closing phase. Thirdly, the duty cycle had a negative effect on reducing response time and had more remarkable influence on the closing response time than opening response time. Lastly, the interaction between driving voltage and duty cycle on closing response time was significant. After that, the optimal control parameter combination for the minimum response time of solenoid time was obtained by analyzing the regression model of response time, which was 12 V voltage for driving solenoid, delayed time of 15 ms and duty cycle of 5%. The predicted optimal control parameters were tested in the laboratory using the modified PWM control method and normal PWM control method which had stable voltage, respectively. The results showed that the measured value by the modified PWM control method was very close to the predicted value and 21.2% of response time could be reduced compared to the normal control method. The result indicates that the RSM is useful for optimizing the parameters of modified PWM control signal to improve the response characteristics of solenoid valve. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Solenoid valves
Controlled terms:Agricultural machinery - Cathode ray oscilloscopes - Counting circuits - Flow of fluids - Models - Optimization - Pulse width modulation - Regression analysis - Response time (computer systems) - Solenoids - Spray nozzles - Surface properties - Valves (mechanical) - Voltage control
Uncontrolled terms:Digital oscilloscope - Experiment platforms - Independent variables - Optimization of parameters - Parameter conditions - Response characteristic - Response surface methodology - Statistical parameters
Classification code:601.2 Machine Components - 619 Pipes, Tanks and Accessories; Plant Engineering Generally - 631.1 Fluid Flow, General - 704.1 Electric Components - 713.4 Pulse Circuits - 731.3 Specific Variables Control - 821.1 Agricultural Machinery and Equipment - 921.5 Optimization Techniques - 922.2 Mathematical Statistics - 942.2 Electric Variables Measurements - 951 Materials Science
DOI:10.11975/j.issn.1002-6819.2016.09.010
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
<RECORD 7>
Accession number:20162002392056
Title:Experiment on influencing factors of power consumption for sawing stem in cutting device of litchi harvester
Authors:Zhao, Runmao (1); Wang, Hongjun (1); Tang, Zhifu (1); Zhang, Bingchao (1); Zou, Xiangjun (1); Ye, Min (1)
Author affiliation:(1) Key Laboratory of Key Technology on Agricultural Machine and Equipment, Ministry of Education, South China Agricultural University, Guangzhou, China
Corresponding author:Wang, Hongjun(xtwhj@scau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:16-21
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:There are 3 main forms of cutter commonly assembled into agricultural harvesters, which are reciprocating cutter, cutter disks and saw blade. Given the fact that the litchi fruits grow in bunches and hang from the bearing shoots, as well as the bionic principle that the cutting-section of the litchi stem must be smooth and unsplit when litchi is picked, it is more suitable to choose the saw blade when the litchi harvester is designed. However, directly using standardized industrial saw blade could not be best in agronomy. Meanwhile, it is indispensable to focus on the studies on the relationship between structure parameters and power consumption of main motor as well as the relationship between motion parameters and power consumption of main motor. After all, the harvester works in outdoor environment. Applying the principles of wood processing and cutting tool technology, the structure and motion parameters were experimentally studied. The experiment was carried out using an universal testing machine, with a 3-jaw chuck mounted on the upper pressure head and the saw blade-motor system installed at the bottom platform. The motor speed, whose current value was real-time measured during the sawing process by a communication multimeter, was controlled by a speed governor. The samples were taken from the Germplasm Collections of Tropical and Subtropical Fruit Species, South China Agricultural University. It was assured that these samples had a length of about 10 mm and a diameter between 5-6 mm, and the branches were straight, with no divergence and free of diseases. Each group of test was conducted on the same stem so as to lower the impact of the diameter and moisture content between different samples. Experiments were designed by using the single-factor method in the study, and 9 kinds of circular saw blades were trial-manufactured, with the combination of 3 kinds of teeth numbers and 3 kinds of face bevel angles. Besides, 3 rotation speed levels were set respectively. There existed a critical rotation speed in the process of stem sawing. If operating speed was lower than the critical speed, stem fibers would not be cut off thoroughly and even cause stem splitting. Therefore, the critical speed of each saw blade was measured by preliminary tests. Finally, a 250 r/min rotation speed was set as the lowest level over the whole experimental process. After all, the results showed that: 1) The instantaneous power consumption of the sawing motor was significantly affected by the face bevel angle (P<0.05), and the rotation speed (P<0.01), but was not affected by the number of teeth; 2) The instantaneous power consumption of the sawing motor increased with the rise of the feeding speed, while decreased with the rise of the face bevel angle and rotation speed. Based on the single-factor experiment, the L<inf>9</inf>(3<sup>4</sup>) orthogonal experiment was carried out. The results showed that: 1) The order from high to low for the effect of each factor on instantaneous power consumption peak was rotation speed, feeding speed, face bevel angle and number of teeth; 2) At given levels, the lowest instantaneous power consumption of the cutting motor was 0.488 J, which was detected under the optimal combination of parameters, i.e. the face bevel angle was 25°, the feeding speed was 60 mm/min, and the rotation speed was 550 r/min. The study may provide theoretical basis for the design of cutting device of litchi harvester. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:18
Main heading:Sawing
Controlled terms:Agricultural machinery - Agriculture - Cutting - Cutting tools - Electric power utilization - Experiments - Feeding - Fruits - Harvesters - Machinery - Mechanization - Rotation - Saws - Speed
Uncontrolled terms:Cutting tool technology - Germplasm collections - Influencing factors - Orthogonal experiment - Single-factor experiments - Structure and motions - Structure parameter - Universal testing machines
Classification code:601 Mechanical Design - 603.2 Machine Tool Accessories - 691.2 Materials Handling Methods - 706.1 Electric Power Systems - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 901.3 Engineering Research - 931.1 Mechanics
DOI:10.11975/j.issn.1002-6819.2016.09.003
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
<RECORD 8>
Accession number:20162002392058
Title:Dynamic simulation on shift process of tractor hydraulic power split continuously variable transmission during acceleration
Authors:Wang, Guangming (1); Zhang, Xiaohui (1); Zhu, Sihong (2); Zhang, Haijun (2); Ma, Ran (3); Tai, Jianjian (1)
Author affiliation:(1) College of Mechanical and Electronic Engineering, Shandong Agricultural University, Tai'an, China; (2) College of Engineering, Nanjing Agricultural University, Nanjing, China; (3) School of Mechanical and Electrical Engineering, Jiangsu Normal University, Xuzhou, China
Corresponding author:Zhang, Xiaohui(zhangxh@sdau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:30-39
Language:English
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The effect of the design parameters of the hydraulic power split continuously variable transmission on the shift process during tractor acceleration was investigated. First, the model of the power train was developed with the software of Simulation X, including the engine, the transmission, the load and the clutch control system, and 8 groups of the experiments were used to validate the correctness of the model. Considering the effect of the rotational inertia on the shift process during acceleration, a complete model of the tractor with the rear axle was built. Then, based on the evaluating index of the tractor peak acceleration and the clutch friction work, five groups of design parameters were simulated and analyzed. According to the simulation results, the trend of the shift process according to the different shift starting time is not monotonous, the shift impact could be reduced by shifting before the designed shift points (about -0.65 s in this study); the maximum slipping time is a function of the flow and pressure of oil, in order to shorten the period of the slipping time and improve the shift quality, long overlap time (0.2 s in this study) and large charge flow (6 L/min in this study) should be used; the large tractor weight can reduce the speed impact of tractor and the friction work of clutch but lead to bad impact on dynamic load, therefore the determination of the tractor weight should fully consider the impact of both the traveling speed and dynamic load of tractor. In addition, the shift impact could also be reduced by using Integrated Hydraulic Pump-Motor and reducing the engine speed during shift, but the effect of the swash plate axial piston units and engine on shift process was not so significant. This study can provide references for the study in continuously variable tractor transmissions and the control system. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Tractors (truck)
Controlled terms:Clutches - Computer simulation - Computer software - Control systems - Dynamic loads - Engines - Friction - Models - Tractors (agricultural) - Transmissions
Uncontrolled terms:Continuously variable transmission - Design parameters - Evaluating index - Peak acceleration - Power splits - Rotational inertia - Shift quality - Tractor transmission
Classification code:408.1 Structural Design, General - 602.2 Mechanical Transmissions - 663.1 Heavy Duty Motor Vehicles - 723 Computer Software, Data Handling and Applications - 723.5 Computer Applications - 731.1 Control Systems
DOI:10.11975/j.issn.1002-6819.2016.09.005
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
<RECORD 9>
Accession number:20162002392064
Title:Numerical simulation and flow field analysis of backwashing of quartz sand filter in micro-irrigation
Authors:Li, Jinghai (1, 2); Zhai, Guoliang (1); Huang, Xiuqiao (1); Feng, Junjie (1); Liu, Yang (1)
Author affiliation:(1) Farmland Irrigation Research Institute, Chinese Academy of Agricultural Sciences/Key Laboratory of Water-saving Agriculture in Henan Province, Xinxiang, China; (2) Water Resources Management Committee Office of Anyang City, Anyang, China
Corresponding author:Huang, Xiuqiao(huangxq626@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:74-82
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Backwashing of quartz sand filter in micro-irrigation is an effective way to realize the regeneration of quartz sand filter media. Analysis of flow field in the backwashing process of quartz sand filter and determination of reasonable backwashing velocity play an important role in the design and operation of the quartz sand filter. The method of numerical simulation has obvious advantage in the analysis and investigation of the flow field in the filter layer. In order to realize the numerical simulation of the backwashing process of quartz sand filter, the geometric model of quartz sand filter was established through Gambit software, and the mesh division of the geometric model was carried out. Because the backwashing process of quartz sand filter layer is a solid-liquid multiphase flow system interacted by both water and quartz sand, in which quartz sand particles are distributed only in a part of the region during the process of backwashing, not being carried away to outside of the filter by the stream, and in which quartz sand accounted for a larger proportion of the whole volume, the Eulerian model was adopted as a model for numerical simulation of backwashing. At the same time, because the backwashing process of quartz sand filter layer is a dynamically stable process, the transient simulation solver was adopted. The simulation objects were three kinds of quartz sand filter layer with the same thickness of 400 mm, but the equivalent particle size were 1.06, 1.2 and 1.5 mm respectively. In order to verify the reliability of simulation results, backwashing experiments were conducted in Farmland Irrigation Research Institute, Chinese Academy of Agricultural Sciences, in 2014. The parameters such as backwashing velocity, pressure drop and expansion height of filter layer were measured. The simulation results were compared with the experimental results. Comparison showed that the maximum simulation error of the whole pressure drop of filter layer was 7.03%, and the maximum simulation error of filter layer density was 1.93%. It was proved that the numerical simulation results were reliable. On this basis, the fluctuation trend of pressure drop with time and the variation trend of the mean value and the standard deviation of the pressure drop with backwashing velocity in backwashing process of quartz sand filter layer were analyzed. If the standard deviation of pressure drop is large, it shows that the fluctuation of pressure drop is unstable, and the unstable fluctuation of pressure drop will affect the effect of backwashing. This result can determine the reasonable range of the backwashing velocity. Then, the distribution rule of the filter layer density with time, the variation trend of the mean value and the standard deviation of the density with the change of the backwashing velocity were analyzed. When the density is close to the static density of the mixture composed of water and quartz sand, the effect of backwashing is poor. When the standard deviation of density is too large, partial concentration phenomenon will appear in the filter layer, which will cause negative influence on the effect of backwashing. Thus, the reasonable range of the backwashing velocity was determined. After combined the rules of pressure drop fluctuation and density distribution, the reasonable ranges of the backwashing velocity of three kinds of filter layer are obtained as 0.0149-0.0212, 0.0146-0.0218 and 0.0191-0.0261 m/s respectively. The research results provided a theoretical basis for the mechanism of quartz sand filter in the process of backwashing. It also provided a technical support for the operation of the sand filter. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:19
Main heading:Sand
Controlled terms:Bandpass filters - Computer simulation - Computer software - Drops - Flow fields - Geometry - Irrigation - Models - Multiphase flow - Numerical methods - Numerical models - Particle size - Pressure drop - Quartz - Stability criteria - Statistics - Velocity
Uncontrolled terms:Back washing - Concentration phenomena - Density distributions - Design and operations - Equivalent particle size - Multi-phase flow systems - Quartz sand - Transient simulation
Classification code:482.2 Minerals - 483.1 Soils and Soil Mechanics - 631.1 Fluid Flow, General - 703.2 Electric Filters - 723 Computer Software, Data Handling and Applications - 723.5 Computer Applications - 821.3 Agricultural Methods - 921 Mathematics - 921.6 Numerical Methods - 922.2 Mathematical Statistics - 961 Systems Science
DOI:10.11975/j.issn.1002-6819.2016.09.011
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
<RECORD 10>
Accession number:20162002392084
Title:Design and experiment of aseptic packaging line of staple wheat food with analytic hierarchy process method
Authors:Xu, Xuemeng (1); Qu, Lingbo (2); Xu, Yun (1)
Author affiliation:(1) School of Mechanical and Electrical Engineering, Henan University of Technology, Zhengzhou, China; (2) School of Mechanical Engineering, Luoyang Institute of Science and Technology, Luoyang, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:219-224
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:A design of aseptic packaging system integrated as the end part of the staple wheat food product line is studied, in order to keep the quality of the staple wheat food in the period of the distribution and sale. There are 3 basic parts in the aseptic packaging system, i.e. drying unit, compound sterilization units and packaging unit, considering influence factors for the food quality during storage and circulation as well as fresh-keeping packaging technology. Three basic parts can be freely used for different kinds of staple wheat food. Four technical schemes of aseptic packaging line are established according to different kinds of drying, sterilization and packaging techniques. The 4 schemes are studied with the analytic hierarchy process (AHP) method. In the AHP analysis process, the hierarchy with 3 criteria i.e. working performance, economic efficiency and reliability, and 9 sub-criteria is established. Through evaluation and priority considering, the optimum scheme is chosen. The aseptic packaging line is carefully designed, which is composed of the infrared drying unit, compound sterilization units of ultraviolet (UV), low temperature, Ozone, packaging machine, and reasonable product flow. In order to achieve industrial production of aseptic packaging for different kinds of staple wheat food, the line can be program-controlled with adjustable parameters, such as drying time, drying temperature, sterilization time, UV illumination intensity and Ozone intensity. The aseptic packaging system is set up in accordance with the above optimum scheme by the AHP method. Chinese steamed bread made of flour with primary moisture content of 43% have been processed by the compound sterilization units of aseptic packaging system under the condition of 4, relative humidity (RH) of 50%-70%, UV illumination intensity of 90-100 µW/m<sup>2</sup>and Ozone intensity of 40-60 mg/m<sup>3</sup>. For processed and the naturally placed Chinese steamed bread, the comparative tests of color, texture and bacterial quantity have been conducted. For color comparison, lightness, contrast by red to green, yellow to blue are determined, while hardness, elasticity and recoverability are for texture comparison. The results show that the Chinese steamed bread processed by the packaging line has better quality and less bacterial quantity than that naturally placed under 25 and 50%-70% RH. The processed Chinese bread is stored in the environment with 4 temperature and 50%-70% RH for the expected guarantee period of 20 d, and the total number of bacteria within it is 3.5 lg (CFU/g), which is lower than the upper limit 4 lg (CFU/g) of the defined by standard, so it can keep the good quality of steamed bread in the expected guarantee period. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:18
Main heading:Thermal processing (foods)
Controlled terms:Analytic hierarchy process - Aseptic conditions - Crystal symmetry - Drying - Food products - Food storage - Hierarchical systems - Infrared drying - Ozone - Packaging - Packaging machines - Product design - Reliability analysis - Sterilization (cleaning) - Temperature - Tungsten compounds
Uncontrolled terms:Adjustable parameters - Analytic hierarchy process (ahp) - Chinese steamed breads - Economic efficiency - Industrial production - Packaging techniques - Packaging technologies - Working performance
Classification code:461.1 Biomedical Engineering - 641.1 Thermodynamics - 694 Packaging - 804 Chemical Products Generally - 822 Food Technology - 913.1 Production Engineering - 933.1.1 Crystal Lattice - 961 Systems Science
DOI:10.11975/j.issn.1002-6819.2016.09.031
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
<RECORD 11>
Accession number:20162002392094
Title:Antioxidants dipping treatment improving quality of frozen tilapia fillets
Authors:Li, Min (1); Guan, Zhiqiang (1); Li, Pengpeng (1)
Author affiliation:(1) School of Engineering, Guangdong Ocean University, Zhanjiang, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:291-298
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to improve the stability of frozen tilapia fillets, thiobarbituric acid (TBA) value, Ca<sup>2+</sup>-ATPase activity, salt-soluble protein content, total volatile basic nitrogen (TVB-N) content and texture were used as the indices. Single-factor experiments that aimed to figure out how antioxidants solution affected the quality of frozen tilapia fillets by dip treating were carried out, and single factors included vitamin E, isoascorbate and tea polyphenols; then an L<inf>9</inf>(3<sup>4</sup>) orthogonal experiment with antioxidant compounds was performed. The rules on how antioxidant solutions with different concentrations influenced the quality of frozen tilapia, including TBA value, Ca<sup>2+</sup>-ATPase activity, salt-soluble protein content, TVB-N content and texture were weighted by subjective weighting method, and all modes of combination were ranked, the optimal concentration of antioxidant solutions and the optimal mode of combination were obtained. The results showed that after single-factor experiments, these 3 antioxidants could improve the quality of frozen tilapia and antioxidant properties, and for the concentration of the impregnation solution, the optimal mass concentrations of vitamin E, sodium ascorbate and tea polyphenols were 6, 6 and 4 g/L respectively, and under the conditions above, the quality index of comprehensive evaluation was increased by 29.11%, 18.46% and 46.28% respectively compared to the control group with distilled water soaking for 60 min. The maximum quality index of comprehensive evaluation corresponded to the 4 g/L tea polyphenols, and accordingly the TBA value, the Ca<sup>2+</sup>-ATPase activity and the mass fraction of salt-soluble protein were 0.1326 mg/kg, 3.00 μmol Piprot/h and 75.82 mg/g respectively. Moreover, after the orthogonal experiment, considering cost analysis combined with better quality, the best combination of antioxidant compounds was 4 g/L sodium erythorbate, 2 g/L vitamin E and 3 g/L tea polyphenols, and accordingly the TBA value, the Ca<sup>2+</sup>-ATPase activity and the mass fraction of salt-soluble protein were 0.1248 mg/kg, 3.12 μmol/(mg·h) and 77.72 mg/g, which was better than the effect of any of single antioxidant, and compared to the control group with distilled water soaking for 60 min, the Ca<sup>2+</sup>-ATPase activity was increased by 52.20%, the mass fraction of salt-soluble protein was increased by 16.78%, and the TBA value was dropped by 46.07%. The composite antioxidant is natural antioxidant formula, its antioxidant property for tilapia fillets has been verified by repeated experiments, which is safe and effective, and the formula is simple and has low cost, so it can be considered to popularization and application in industrial production. Moreover, the results can provide the theoretical basis for the antioxidants application in the frozen aquatic products, which may improve the frozen quality. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:34
Main heading:Quality control
Controlled terms:Antioxidants - Cost benefit analysis - Energy storage - Freezing - Proteins - Quality assurance
Uncontrolled terms:Antioxidant properties - Comprehensive evaluation - Impregnation solution - Industrial production - Orthogonal experiment - Single-factor experiments - Tilapia fillets - Total volatile basic nitrogens
Classification code:525.7 Energy Storage - 804.1 Organic Compounds - 911 Cost and Value Engineering; Industrial Economics - 913.3 Quality Assurance and Control
DOI:10.11975/j.issn.1002-6819.2016.09.041
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
<RECORD 12>
Accession number:20162002392096
Title:Summarization on vegetable oil extraction technology by aqueous medium method
Authors:Yang, Ruijin (1, 2); Ni, Shuangshuang (2); Zhang, Wenbin (1, 2); Li, Pengfei (2); Liu, Junjun (2); Xie, Bin (2)
Author affiliation:(1) State Key Laboratory of Food Science & Technology and School of Food Science and Technology, Jiangnan University, Wuxi, China; (2) School of Food Science and Technology, Jiangnan University, Wuxi, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:308-314
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Vegetable oil is an exceedingly important and indispensable part of the modern diet. Most of the production methods of vegetable oils in traditional commercial company are the hot-pressing method and/or the solvent extraction method. The hot-pressing method is a conventional oil production method in which oilseeds are firstly treated under hyperthermal condition and then exuded by mechanical extrusion. This method has the characteristics of simple equipment and universality on the production of different oils, but its oil yield is relatively low. In addition, during the long-time hyperthermal treatment, oil may be oxidized, and then the oxidation product would degrade and generate some harmful compositions, such as trans-fatty acid and polycyclic aromatic hydrocarbons. The solvent extraction method applies hexane as extraction solvent chiefly, and has a high oil yield (>96%). But in hexane extraction, many byproducts would be dissolved out with the oil, which leads to the inferior physical-chemical characteristics of crude oil. Hence, the deep refining is needed, however, excessive refining not only causes the loss of nutrients, but also may bring new harmful substances, such as plasticizers, heavy metals and chlorine propanol esters. Furthermore, hexane has been identified as the hazardous air pollutant. Because of the toxicity and flammability of hexane and the increasing demand of food safety, the development of alternative green production process of vegetable oils is becoming extraordinarily urgent. The aqueous extraction method is recently receiving considerable attention, in which pure water is employed as main extraction medium. It is a new developed green and efficient oil extraction technology. Compared with traditional technology, this method is mild and safe due to the relatively low temperature and the complete avoidance of organic solvents. Based on the decades of our team's research work on the aqueous medium extraction technology, we have established the concept of aqueous medium method of vegetable oil extraction technology firstly in this review. The so-called aqueous medium method of vegetable oil extraction technology employs pure water as the main extraction medium, with or without the assistance of edible substances that are miscible with water like ethanol, food-grade enzyme, supersonic and microwave. The effects of these supplements were to destroy the cell wall of oil-bearing materials or prevent the formation of highly-creamed emulsion in extraction process. This method contains aqueous extraction method, aqueous enzymatic extraction method and aqueous ethanol extraction method. In this review, the technological process, technical features, development history, existing problems and promising prospects are also discussed in detail. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:42
Main heading:Extraction
Controlled terms:Aromatic hydrocarbons - Byproducts - Crude oil - Emulsification - Ethanol - Fatty acids - Heavy metals - Hexane - Hot pressing - Oil bearing formations - Oils and fats - Plants (botany) - Polycyclic aromatic hydrocarbons - Refining - Solvent extraction - Solvents - Technology - Temperature - Vegetable oils - Water - Well stimulation
Uncontrolled terms:Aqueous enzymatic extraction - Aqueous ethanol - Aqueous extraction - Aqueous medium - Chemical characteristic - Extraction technology - Hazardous air pollutants - Solvent extraction methods
Classification code:512.1 Petroleum Deposits - 512.1.1 Oil Fields - 531 Metallurgy and Metallography - 641.1 Thermodynamics - 802.3 Chemical Operations - 803 Chemical Agents and Basic Industrial Chemicals - 804 Chemical Products Generally - 804.1 Organic Compounds
DOI:10.11975/j.issn.1002-6819.2016.09.043
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
<RECORD 13>
Accession number:20162002392072
Title:Effects of different width of scouring flumes on runoff and sediment yield of colluvial deposits of collapsing hill
Authors:Li, Xuezeng (1); Huang, Yanhe (1); Lin, Jinshi (1); Jiang, Fangshi (1); Hao, Fuxing (1); Guan, Jiachun (1); Xu, Huangji (1); Yang, Dandan (1); Wang, Zhenhong (1)
Author affiliation:(1) College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou, China
Corresponding author:Huang, Yanhe(yanhehuang@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:136-141
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Collapsing hill is the typical and serious erosion phenomenon in the red soil area of southern China. The colluvial deposit erosion is the main sediment source of collapsing hill, which has the characteristics of loose texture, bad structure, and high erodibility. Study of the influence of elements on erosion sediment in the process of slope erosion is of great significance for revealing the mechanism of slope erosion. The width of scouring flumes is one of the factors that affect the characteristics of erosion and yield of runoff and sediment in the process of slope scouring erosion but now has fewer research achievements. With the colluvial deposits of collapsing hill as the research object, and through the simulated scouring in laboratory, this study intended to disclose the impacts of different width of scouring flumes (10, 20, 30, 40 and 50 cm) and discharge per unit width (1.2×10<sup>-2</sup>, 2.4×10<sup>-2</sup>, 3.6×10<sup>-2</sup>and 4.8×10<sup>-2</sup>m<sup>2</sup>/min) on the slope scouring erosion and runoff and sediment yield of colluvial deposits. Soil samples were collected from the Longmen Town, Anxi County, Fujian Province in southeast China, and preprocessed according to the experimental standards. Results showed that: 1) The width of scouring flumes had significant effects on the runoff rate and sediment yield rate when the discharge per unit width was 1.2×10<sup>-2</sup>, 2.4×10<sup>-2</sup>and 3.6×10<sup>-2</sup>m<sup>2</sup>/min (P<0.05), while had no significant effects when the discharge per unit width was 4.8×10<sup>-2</sup>m<sup>2</sup>/min; 2) When the discharge per unit width was 1.2×10<sup>-2</sup>m<sup>2</sup>/min, the runoff rate increased gradually with the increase in time, when the discharge per unit width was 2.4×10<sup>-2</sup>and 3.6×10<sup>-2</sup>m<sup>2</sup>/min, the runoff rate increased at first and then became stable with the increase in time, and when the discharge per unit width was 4.8×10<sup>-2</sup>m<sup>2</sup>/min, the runoff rate increased at first and then decreased with the increase in time; when the discharge per unit width was 1.2×10<sup>-2</sup>m<sup>2</sup>/min, the trends of sediment yield rate and sediment concentration over time under different width of scouring flumes were different, and when the width of scouring flumes was 10, 20 and 30 cm, the sediment yield rate and sediment concentration increased at first and then became fluctuant, but increased with time all the way while the width of scouring flumes was 40 and 50 cm; when the discharge per unit width was 2.4×10<sup>-2</sup>, 3.6×10<sup>-2</sup>and 4.8×10<sup>-2</sup>m<sup>2</sup>/min, the sediment yield rate and sediment concentration under each width of scouring flumes showed an increase-stability-decrease trend with the increase in time; 3) When the discharge per unit width was constant, the difference of the cumulative runoff yield under different width of scouring flumes was not significant, and that of the cumulative sediment yield and the average sediment concentration were significant (P<0.05) while the discharge per unit width was 1.2×10<sup>-2</sup>, 2.4×10<sup>-2</sup>and 3.6×10<sup>-2</sup>m<sup>2</sup>/min; when the discharge per unit width was 4.8×10<sup>-2</sup>m<sup>2</sup>/min, the width of scouring flumes had no significant effects on the cumulative sediment yield and the average sediment concentration; 4) The width of scouring flumes had no effects on slope erosion and characteristics of runoff and sediment yield when the discharge per unit width was 4.8×10<sup>-2</sup>m<sup>2</sup>/min, and thus, faculative width of scouring flumes could be chosen while the discharge per unit width was 4.8×10<sup>-2</sup>m<sup>2</sup>/min. This research has used the colluvial deposits of collapsing hill as the research object and carried out the experiments under the condition of 15° slope, but colluvial deposits' characteristics (loose texture, bad structure, high erodibility) are obviously different from other soil types, and thus, more studies aiming at other soil types about the effects of different width of scouring flumes on erosion and yield of runoff and sediment are needed, and further researches can also be conducted with other slope gradients. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:22
Main heading:Sediments
Controlled terms:Deposits - Erosion - Runoff - Sand - Scour - Sedimentation - Slope stability - Soils
Uncontrolled terms:Collapsing hill - Colluvial deposits - Per unit - Research achievements - Runoff and sediment yields - Runoff and sediments - Sediment concentration - Width of scouring flumes
Classification code:406.2 Roads and Streets - 442.1 Flood Control - 483 Soil Mechanics and Foundations - 483.1 Soils and Soil Mechanics - 802.3 Chemical Operations - 951 Materials Science
DOI:10.11975/j.issn.1002-6819.2016.09.019
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
<RECORD 14>
Accession number:20162002392069
Title:Impacts of type and concentration of salt cations on soil water retention and desiccation cracking
Authors:Xing, Xuguang (1, 2); Ma, Xiaoyi (1, 2); Kang, Duangang (1, 2)
Author affiliation:(1) College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling, China; (2) Key Laboratory for Agricultural Soil and Water Engineering in Arid Area of Ministry of Education, Northwest A&F University, Yangling, China
Corresponding author:Ma, Xiaoyi(xiaoyima@vip.sina.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:115-122
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The soil water characteristic curve (SWCC) defines the relationship between soil suction and volumetric water content, and is commonly used to evaluate the size and distribution of soil pores and the soil water availability and holding capacity for investigating the functions of unsaturated soil with various properties and for modeling the transport of soil water and solutes. Besides, the SWCC is usually effectively used to evaluate soil water retention, which is always considered as a basic factor for determining reasonable irrigation schemes. The SWCC can be obtained via centrifuge method; however, soil samples often shrink and crack during the SWCC measurement. Of various influencing factors on water retention, salt ions with different types and concentrations have various effects on water-holding capacity. The present study therefore aims to explore the differences in the characteristics of the soil water retention and the shrinkage and cracking during drying process resulting from 4 types of salt cations with different concentrations. In order to achieve the objectives, silty clay loam from Shaanxi Province was selected as experimental soil. Four replicates of the samples were air dried, sieved through a 2-mm mesh, and then compacted into cutting rings at a bulk density of 1.40 g/cm<sup>3</sup>. Four powder reagents, namely potassium chloride (KCl), sodium chloride (NaCl), calcium chloride (CaCl<inf>2</inf>) and magnesium chloride (MgCl<inf>2</inf>), which included 4 kinds of salt cations (i.e., K<sup>+</sup>, Na<sup>+</sup>, Ca<sup>2+</sup>and Mg<sup>2+</sup>), were dissolved in distilled water at the concentration of 5, 30 and 100 g/L respectively. Distilled water was used as the control (CK). And all soil samples were first saturated in the solutions for 48 h before the experiment. The SWCCs were then constructed using a centrifugal method and used to quantitatively assess soil water holding capacity. At the same time, the deposit height of soil samples for each tested soil suction was measured using a vernier caliper, which was used to calculate linear shrinkage ratio and axial shrinkage strain for quantitatively evaluating soil shrinkage during the drying process. Cracks gradually occurred with soil water decreasing and were obtained using digital image processing technique in this paper, which were used to quantitatively evaluate the desiccation cracking based on crack area density and length density. The experimental results showed that first of all, salt cations had no effects on the SWCC shape, and the van Genuchten model was suitable for fitting SWCC saturated by saline solution with the R<sup>2</sup>of high than 0.99. Furthermore, the 4 kinds of salt cations could weaken soil water retention, and water-holding capacity was correlated negatively with the concentration of salt cation. According to the fitting results by the van Genuchten model, the 4 kinds of salt cations could also weaken saturated water content, residual water content and air suction, and water-holding capacity was correlated negatively with saturated water content. Besides, K<sup>+</sup>, Na<sup>+</sup>with high concentration and Mg<sup>2+</sup>with low concentration were helpful to decrease soil axial shrinkage. And the axial shrinkage strain was correlated negatively with the concentration of K<sup>+</sup>(P<0.01), Na<sup>+</sup>(P<0.05) and Ca<sup>2+</sup>and positively with Mg<sup>2+</sup>concentration. Shrink of soils during the drying process was accompanied with the increasing of soil bulk density, and the effect of salt cations ranked in the order of Mg<sup>2+</sup>>Ca<sup>2+</sup>>Na<sup>+</sup>>K<sup>+</sup>. Finally, the 4 kinds of salt cations were helpful to weaken cracking based on the quantitative analysis of crack area density and length density. And these 2 crack indicators were significantly negatively correlated with the concentration of K<sup>+</sup>, Na<sup>+</sup>and Ca<sup>2+</sup>and positively with Mg<sup>2+</sup>concentration. These findings are helpful to provide the theoretical and practical guidance for the evaluation of water retention and the determination of irrigation scheme, and to provide some references for developing the engineering practice on saline soils. The further study should add focuses on the effects of salt anions and smaller concentration gradient on soil water retention and desiccation cracking. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:40
Main heading:Soil surveys
Controlled terms:Cracks - Driers (materials) - Drying - Image processing - Ions - Irrigation - Magnesium powder - Moisture - Positive ions - Saline water - Salts - Shrinkage - Sodium chloride - Soil moisture - Soils
Uncontrolled terms:Concentration gradients - Digital image processing technique - Linear shrinkage ratio - Sodium chloride (NaCl) - Soil water availability - The soil-water characteristic curves (SWCC) - Volumetric water content - Water retention
Classification code:444 Water Resources - 483.1 Soils and Soil Mechanics - 542.2 Magnesium and Alloys - 803 Chemical Agents and Basic Industrial Chemicals - 821.3 Agricultural Methods - 951 Materials Science
DOI:10.11975/j.issn.1002-6819.2016.09.016
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
<RECORD 15>
Accession number:20162002392082
Title:Peasant household type and its land use pattern in Melamchi basin of central mountainous area in Nepal
Authors:Su, Yi (1, 2); Deng, Wei (1, 2); Zhang, Jifei (1); Hriday, Lal Koirala (3)
Author affiliation:(1) Institute of Mountain Hazards and Environment, Chinese Academy of Science, Chengdu, China; (2) University of Chinese Academy of Science, Beijing, China; (3) Central Department of Geography, Tribhuvan University, Kathmandu, Nepal
Corresponding author:Deng, Wei(dengwei@imde.ac.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:204-211
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Changes in household livelihood strategy have provided a new research perspective for land utilization changes. By means of questionnaire survey, semi-structured interview, mathematical statistics and other research methods, this research conducts a systematic investigation on the households and land plots of 4 typical villages located at the Melamchi basin in the central mountainous areas in Nepal. Then based on the income combinations, this research classifies the peasant households into 4 types, which are pure agriculture type, agriculture-dependent type, non-farming-dependent type and non-agriculture type. With above classification, the analysis is carried out on different types of households' livelihood strategies and land use patterns, in terms of the number of land plots, the area of land, the renting of land, the arrangement of labor forces and the yield-increasing input and so on. Through contrastive study on different types of households' perceptions and strategies of livelihood improving, this paper analyzes their influences on land use and comes up with the suggestions including properly utilizing land resources as well as improving household livelihood capability and level. The results show that different types of households reflect different characteristics in their family scale, family member, labor allocation, age structure and cultural level. To be specific, for the households of agriculture-dependent type and non-farming-dependent type, their livelihood strategy combination is better and livelihood diversity index is higher, and hence they possess relatively lower livelihood risks. Different households' land use patterns are obviously different. From the angle of the area of land, land area per household and per capita, it can be summarized as the sequence of agriculture-dependent type>pure agriculture type>non-farming-dependent type>non-agriculture type. Among these, the households of agriculture-dependent type possess the largest renting land coverage. From the perspective of cultivating land structure, various types of households all plant food crops as the primary crop, whereas relatively fewer households and fewer lands focus on economic crops. Comparatively, the households of agriculture-dependent type occupy the highest proportion and area of economic crop planning; as for labor input, agriculture-dependent type has the largest labor input and their male labor proportion is the highest as well; as for land yield-increasing input, the proportion of households using fertilizer in Helambu Village shows agriculture-dependent type>pure agriculture type>non-farming-dependent type, but the proportion of households in the other 3 villages shows non-farming-dependent type>pure agriculture type>agriculture-dependent type. And non-farming-dependent type occupies the largest land yield-increasing input per unit area land. Because different types of households' perceptions and strategies of livelihood improving are not same, their influences on land use are varied. The largest demands of households are to establish irrigation facilities, increase agricultural yield-increasing input, improve breeding technology guide, enhance skill training and increase local employment opportunities, encourage loans with interest subsidy or lower interest, and construct roads and so on. And they are important measures to reduce the rate of land reclamation. Non-agricultural livelihood activities will not only reduce the vulnerability and risks of livelihood, but also reduce household's dependency degree and reclamation ratio to the land, which will promote the change of land ownership and land re-distribution and improve agricultural production rate. However, this will also increase the risk of land quality devolution and environmental pollution. Given the resource environment features in the mountainous areas of Nepal and unfavorable factors hindering the improvement of households' livelihood, this paper comes up with feasible strategies of improving household's livelihood and promoting the sustainable utilization of land from both household level and regional level. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:34
Main heading:Land reclamation
Controlled terms:Agriculture - Crops - Forestry - Land use - Optimization - Rural areas - Statistics - Surveys
Uncontrolled terms:Agricultural productions - Environmental pollutions - Households types - Livelihood strategies - Mountainous area - Nepal - Semi structured interviews - Sustainable utilization
Classification code:403 Urban and Regional Planning and Development - 442.2 Land Reclamation - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.4 Agricultural Products - 921.5 Optimization Techniques - 922.2 Mathematical Statistics
DOI:10.11975/j.issn.1002-6819.2016.09.029
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
<RECORD 16>
Accession number:20162002392079
Title:Dynamic experiment of biogas desulfurization by activated carbon
Authors:Shi, Fengmei (1); Pei, Zhanjiang (1); Wang, Su (1); Gao, Yabing (1); Sun, Bin (1); Liu, Jie (1)
Author affiliation:(1) Rural Energy Institute of Heilongjiang Academy of Agricultural Sciences, Harbin, China
Corresponding author:Liu, Jie(Liujie@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:187-192
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The world suffers the fossil energy crisis, and biogas gains more and more attention for it is a kind of reproducible, clean and environmental-friendly energy. Biogas comes from the anaerobic fermentation of organic materials in agriculture, industry and household waste at certain temperature and pressure. The concentration of H<inf>2</inf>S in biogas varies from 10 to 2 000 ×10<sup>-6</sup>or even more, which is different with the type, concentration of organic materials and the operation of anaerobic digestion process. In order to use biogas safely, the H<inf>2</inf>S in biogas which is hazardous to the equipment or human health should be removed from the biogas. Purification methods of H<inf>2</inf>S vary from simple physical or chemical technology to complex process including chemical, physical or biological treatment units, which depended on the use purpose of biogas. Activated carbon is a highly porous material, and known as an efficient media for low-concentration H<inf>2</inf>S removal by adsorption process. Moreover, activated carbon is easily available and cheap in price, because it is produced from biomass such as agricultural waste, wood, bamboo, coconut shells, and almond shells, which is abundant in China. Currently, most efforts are made in the study on H<inf>2</inf>S adsorption by modified activated carbon such as impregnated activated carbon with alkali or heavy metal salts. The modified active carbon has the better performances in most cases, but it is proved to have negative effects on the removal of H<inf>2</inf>S. For example, active carbon's absorption capacity of H<inf>2</inf>S will decrease when the crystals of alkali or metal salts block the pores which act as adsorption site. The price of impregnated active carbon is higher than unmodified activated carbon and the corrosion often occurs inevitably. It is necessary to study the most efficient way to improve the performance of unmodified active carbon. Thus, the effects of the inflow rate, the concentration of H<inf>2</inf>S, the size of unmodified activated carbon and the length of the fixed adsorption bed on activated carbon's adsorption capacity of H<inf>2</inf>S and the breakthrough time through fixed adsorption column were investigated. The adsorption capacity of H<inf>2</inf>S was 1.20 and 1.86 mg/g when the effluent H<inf>2</inf>S concentration was 0.0124% and 0.0454% respectively. The adsorption capacity of H<inf>2</inf>S with the effluent rate of 0.15 L/min was 1.6 times that with the effluent rate of 0.30 L/min, and the adsorption capacity of H<inf>2</inf>S with the particle size of 0.84-2.00 mm was only 58% of that with the particle size of 0.42-0.84 mm. Therefore, it could enhance activated carbon's adsorption capacity of H<inf>2</inf>S by increasing the inlet concentration of H<inf>2</inf>S, decreasing the inflow rate and utilizing the small-size particles. The adsorption process was modeled by Bangham equation. The H<inf>2</inf>S adsorption capacity of unmodified activated carbon could be well described by Bangham equation. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Desulfurization
Controlled terms:Activated carbon - Adsorption - Agricultural wastes - Agriculture - Anaerobic digestion - Biogas - Biohazards - Bioremediation - Effluents - Energy policy - Heavy metals - Particle size - Porous materials - Salts
Uncontrolled terms:Anaerobic digestion process - Anaerobic fermentation - Bangham equation - Environmental-friendly - Highly porous materials - Impregnated activated carbon - Modified activated carbons - Temperature and pressures
Classification code:452.3 Industrial Wastes - 454.2 Environmental Impact and Protection - 525.6 Energy Policy - 531 Metallurgy and Metallography - 802.3 Chemical Operations - 804 Chemical Products Generally - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.5 Agricultural Wastes - 914.1 Accidents and Accident Prevention - 951 Materials Science
DOI:10.11975/j.issn.1002-6819.2016.09.026
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
<RECORD 17>
Accession number:20162002392088
Title:Red and blue LED weak light irradiation maintaining quality of cherry tomatoes during cold storage
Authors:Lei, Jing (1); Zhang, Na (2); Yan, Ruixiang (2); Xu, Lixing (1); Li, Ying (1); Guan, Wenqiang (1)
Author affiliation:(1) Tianjin Key Laboratory of Food Biotechnology, College of Biotechnology and Food Sciences, Tianjin University of Commerce, Tianjin, China; (2) National Engineering and Technology Research Center for Preservation of Agricultural Products (Tianjin), Tianjin Key Laboratory of Postharvest Physiology and Storage of Agricultural Products, Tianjin, China
Corresponding author:Guan, Wenqiang(gwq18@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:248-254
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Tomatoes are rich in compounds including carotenoids, vitamin C (Vc), and flavonoids, which are believed to be beneficial to human health. The increasing growth in the consumption of fresh cherry tomato (Lycopersicon esculentum Mill.) has driven the demand for developing new green postharvest technology to maintain the quality during cherry tomato's storage period and shelf life. Blue and red lights among visible light regions may be still useful for the photosynthesis of some fresh products that are not fully mature during storage. Light-emitting diodes (LEDs) technologies could provide some opportunities to develop new equipment and method for controlling postharvest quality of cherry tomato treated by different light sources during storage and shelf life. Mature-green (breaker-stage) tomatoes were harvested and treated continuously with red and blue LED weak light at 4 for up to 20 d. Untreated tomatoes (the control) were kept in the dark for the same period. The effects of the treatments on the sensory quality (levels of appearance, color, odor and decay), Vc, reducing sugar, total soluble sugar, total soluble solids, titratable acid and lycopene were evaluated throughout the storage. The results showed that LED irradiation apparatus used in the experiment was stable and reliable. LED red and blue lamps could emit the designated light spectrum and not drift as the change of light intensity. The sensory quality was maintained at high level in all treatment during early storage period. After 10 d storage, the cherry tomatoes irradiated by LED red and blue light began to change color to yellow and red and had significantly better sensory quality than the control treatment (P<0.05), and LED red light had better effect than LED blue light. On the 20<sup>th</sup>day, the cherry tomatoes in the control showed inferior sensory quality involving flesh severe softening, apparent browning pitting on the peel and fungal decay spot, while the tomatoes irradiated by LED red and blue light kept good sensory quality (P<0.05). LED blue light irradiation could significantly inhibit the decrease of Vc content (P<0.05) in cherry tomato during storage compared with the control treatment, while the cherry tomatoes irradiated by LED red light showed lower Vc content than the control. LED red and blue light irradiation could lead to the accumulation of reducing sugar and total soluble sugar in cherry tomato during the early stage of storage, and reducing sugar and total soluble sugar content reached the highest on the 10<sup>th</sup>day. The contents of reducing sugar and total soluble sugar in cherry tomatoes decreased gradually between the 10<sup>th</sup>and the 20<sup>th</sup>day, while it was higher in the tomatoes irradiated by LED red and blue weak light than that in the control during the whole storage (P<0.05). Compared to the control, LED red and blue light irradiation could significantly delay the decrease of total soluble solids content and titratable acid content in cherry tomato (P<0.05), and LED red light had significantly higher effect than LED blue light (P<0.05). LED red light irradiation could lead to significantly higher lycopene content on the 20<sup>th</sup>day, while there was no significant difference between LED blue light and the control during storage. In comparison with the control treatment, LED red and blue weak light irradiation was beneficial for controlling the sensory and nutritional quality of cherry tomato at 4, completing the ripening process, and keeping the normal postharvest physiological metabolism. LED red weak light irradiation had the best effect among the treatments. In conclusion, LED red and blue weak light irradiation, as a simple and effective postharvest method, has the potential of application in the postharvest quality control of cherry tomato. The results provide the basis for sensory and nutritional quality control of fresh fruits and vegetables during cold storage. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Light emitting diodes
Controlled terms:Cold storage - Energy storage - Fruits - Irradiation - Light - Light sources - Quality assurance - Quality control - Radiation - Vegetables
Uncontrolled terms:Cherry tomatoes - Nutritional qualities - Post-harvest technologies - Postharvest quality - Soluble sugar contents - Total soluble solids - Total soluble solids content - Visible light region
Classification code:525.7 Energy Storage - 644.3 Refrigeration Equipment and Components - 714.2 Semiconductor Devices and Integrated Circuits - 741.1 Light/Optics - 821.4 Agricultural Products - 913.3 Quality Assurance and Control
DOI:10.11975/j.issn.1002-6819.2016.09.035
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
<RECORD 18>
Accession number:20162002392060
Title:Kinematic analysis of leg mechanism of six-legged walking robot
Authors:Zhang, Jinzhu (1); Jin, Zhenlin (1, 2); Chen, Guangguang (1)
Author affiliation:(1) College of Mechanical Engineering, Yanshan University, Qinhuangdao, China; (2) State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, Shanghai, China
Corresponding author:Jin, Zhenlin(zljin@ysu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:45-52
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to increase the automation level of agricultural operations, broaden the application scope of agricultural robot, and improve the ability of adapting to the different working environment and flexible work, a novel three-degree-of-freedom leg mechanism used in the six-legged walking robot is introduced. This leg mechanism comprised a drive mechanism based on 2RUS+RU parallel manipulator and a traveling mechanism based on parallelogram mechanism. The motor of drive mechanism is fixed on body frame. This leg mechanism has not only the advantage of parallel mechanism, but also a good protectiveness. In this paper, kinematic analysis and simulation of leg mechanism of six-legged walking robot is accomplished. Firstly, based on the intrinsic relation between the angular velocity and the angular velocity of Euler angles of the dynamic platform, the relationship matrix between linear velocity and angular velocity of driving mechanism is established. Based on that, the entire Jacbian matrix in the 3×3 form of the leg mechanism is deduced by using the relationship matrix derivative method, and the explicit Hessian matrix in the 3×3×3 form of the parallel drive mechanism and the leg walking mechanism is obtained, which also adopts the method of derivative matrix. Secondly, with the rationed rotation angle of the revolute joint ranging in [-45°, 45°], a distribution diagram of condition number of the integral Jacobian matrix is drawn. The condition number of integral Jacobian matrix is changed slowly and smaller in the central region of the workspace in this diagram, so that the mechanism flexibility is good in this area and can meet the requirements of the robot movement. Lastly, under the conditions that were step increment of 300 mm and crossing obstacle height of 200 mm, the trajectory planning of the foot end is accomplished and the track function of the foot end is presented based on the method of combined polynomial, which can make the robot stable and free from impact and have a good landing performance in the process of motion. Under the condition of the geometrical parameters of the leg mechanism, the simulation model of the robot's leg is established and the track function of the foot end is presented when the six-legged walking robot walks straight. The function of the trajectory is as input. The velocity and acceleration curves of driver deputy based on the analytical solutions and virtual prototype are described. Through the data analysis in curves, the accuracy of angular velocity and angular acceleration based on the theory and simulation results both can reach 10<sup>-3</sup>mm, which indicates that the theoretic analysis is correct and feasible. In addition, the simulation results show that the maximum of angular velocity of drive joint is less than 0.33π rad/s and the maximum of angular acceleration of drive joint is less than 1.22π rad/s. Therefore, the driving speed and torque of leg mechanism are both smaller in the course of the planned trajectory movement, which is favorable to drive. Accordingly, the rationality of the trajectory planning is confirmed. The results can provide the theoretical reference for the development and control of the hexapod robot. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:26
Main heading:Robot programming
Controlled terms:Agriculture - Angular velocity - Computer simulation - Degrees of freedom (mechanics) - Digital storage - Geometry - Jacobian matrices - Kinematics - Manipulators - Matrix algebra - Mechanisms - Mobile robots - Number theory - Robots - Trajectories - Velocity
Uncontrolled terms:Agricultural operations - Development and controls - Distribution diagram - Parallel manipulators - Parallelogram mechanisms - Six-legged walking robots - Three degree of freedoms - Trajectory Planning
Classification code:601.3 Mechanisms - 722.1 Data Storage, Equipment and Techniques - 723.5 Computer Applications - 731.5 Robotics - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 921 Mathematics - 921.1 Algebra - 931.1 Mechanics
DOI:10.11975/j.issn.1002-6819.2016.09.007
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
<RECORD 19>
Accession number:20162002392087
Title:Technologic parameter optimization in pilot-scale process of heat pump drying of Areca catechu L.
Authors:Zhang, Ronghu (1); Gao, Yuanneng (2); Feng, Jiancheng (3); Xie, Hui (1); Deng, Hao (1); Zhuang, Guanghui (1); Dou, Zhihao (1)
Author affiliation:(1) Institute of Processing & Design of Agroproducts, Hainan Academy of Agricultural Science, Haikou, China; (2) Hainan Quanneng Energy Co. Ltd, Wanning, China; (3) College of Materials and Chemical Engineering, Hainan University, Haikou, China
Corresponding author:Dou, Zhihao(513408658@qq.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:241-247
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Areca catechu L. belongs to perennial aiphyllium of palmae. It has very high medicinal value and is regarded as the first one of 4 kinds of the south medicines in China. Areca catechu L. abounds in Hainan, 10% for fresh food, more than 90% dried for further processing, Areca catechu L. drying has become the important processing industry in Hainan, the annual output of dried betel nut is about 200 000 t, and the annual output value is more than 10 billion yuan. For the Areca catechu L. drying, there are hot air drying and vacuum freeze drying, which have not been applied in production because of the limitation of experimental conditions and equipments, and the traditional furnace drying, steam drying and heat pump drying are used in production. The traditional furnace drying is a kind of small workshop processing, and its characteristics of small scale, large labor intensity and serious pollution are difficult to adapt to the modern agriculture development, so it has been gradually eliminated. For the steam drying whose heat source is from the burning coal, the characteristic of large scale and high mechanical strength adapts to the intensive agricultural product processing development, however it is limited because of a lot of greenhouse gases emitted from burning coal. Only the energy-conservation and environment-protection drying method is suitable for the Areca catechu L. drying industry's sustainable and healthy development. The betel nut drying was studied using the heat pump drying equipment in this paper. The influences of boiling time on betel nut hardness, and drying temperature and loading capacity on moisture content of dried fruit were analyzed via the single factor experiment. The technology parameters of heat pump drying were optimized by the orthogonal experiment, and the quality of the dried betel nut was evaluated using the weighted score method. After 30-day storage, the physical, chemical and microbiological indicators of the dried fruits were detected, and moreover, the advantages and benefits were analyzed based on the comparison between the heat pump drying method and the steam drying and traditional drying methods. The optimum drying parameters were: boiling time of 15 min, initial drying time of 12 h at 50, following drying time of 84 h at 65, loading capacity of 3.5 t, 25% air relative humidity of dried room, and 16.8% water content of betel nut. The results showed as follows: the ratio of good dried fruit was 96%, the uniformity of dried fruit was 91%, the power consumption of dried fruit was 0.92 (kW·h)/kg, the comprehensive score of dried betel nut quality was 90.1, and the color of dried fruit was either olive yellow or brown. After 30-day storage at 25, the dried fruit did not mildew, and the physical and chemical indicators were in the controllable range. The cost of drying betel nut by heat pump was more economical, 11% lower than that of the steam drying and 50% lower than that of the traditional drying. The heat pump drying had the advantages of energy saving, low emissions, intelligent operation, low drying cost and good economic benefit. The research results provide the technical reference for the standardized processing of the betel fruit with the heat pump drying method. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:22
Main heading:Drying
Controlled terms:Agricultural products - Agriculture - Chemical analysis - Energy conservation - Fruits - Greenhouse gases - Heat pump systems - Indicators (chemical) - Optimization - Processing - Pumps - Steam - Thermal processing (foods) - Vacuum furnaces
Uncontrolled terms:Betel nut - Environment protection - Experimental conditions - Heat pumps - High mechanical strength - Intelligent operations - Single-factor experiments - Value methods
Classification code:451.1 Air Pollution Sources - 525.2 Energy Conservation - 616.1 Heat Exchange Equipment and Components - 618.2 Pumps - 801 Chemistry - 804 Chemical Products Generally - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.4 Agricultural Products - 822.2 Food Processing Operations - 913.4 Manufacturing - 921.5 Optimization Techniques
DOI:10.11975/j.issn.1002-6819.2016.09.034
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
<RECORD 20>
Accession number:20162002392054
Title:Analysis and experiment of tillage depth and width stability for plowing and rotary tillage combined machine
Authors:Qin, Kuan (1, 2); Ding, Weimin (1, 2); Fang, Zhichao (1, 2); Du, Taotao (1); Zhao, Siqi (1); Wang, Zhen (1)
Author affiliation:(1) College of Engineering, Nanjing Agricultural University, Nanjing, China; (2) Jiangsu Key Laboratory for Intelligent Agricultural Equipment, Nanjing, China
Corresponding author:Ding, Weimin(wmding@njau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:1-8
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The plowing and rotary tillage combined machine developed in this study is a duplex-operation scarification machine designed with the combination of plough mechanism and rotary tillage mechanism in the front. Such a design allows the cultivator to accomplish multiple tasks simultaneously, such as plow tillage, rotary tillage, straw chopping for mulching, soil pulverization, soil covering, and surface leveling. To investigate the stability of the plowing and rotary tillage combined machine, the factors such as cultivator tillage stability were examined from 3 different aspects: traction, force analysis in the horizontal plane, and vibration analysis. The center of mass of the machine could be determined on the longitudinal vertical plane of the machine, where the traction line passing through the instantaneous center of rotation intersected with the vertical line passing through the center of mass. The traction angle (15°-30°), i.e., the angle between traction line and horizontal line, was a crucial factor affecting tillage stability. The forces acting on the machine on the horizontal plane during operation were analyzed to obtain the plow tilt angle (23°-30°) from the equilibrium equations of the plough, rotary blade, and traction forces on the horizontal plane; the plow tilt angle affected tillage stability by directly impacting the force balance on the horizontal plane. From an analysis of the vibrational excitation during machine operation, it was determined that alternating load in rotary blade operations was the main source of machine vibration excitation. The lift angle of the rotary blade (54°-85°) affected the alternating load, therefore influencing tillage stability. The traction angle, plow tilt angle, and lift angle of the rotary blade were used as the experimental variables, and the stability coefficient under tillage depth-based working conditions and the stability coefficient under tillage width-based working conditions were used as the experimental indicators in a 3-factor/2-level quadratic orthogonal rotating combinatorial test to determine the optimal parameter combination of the influencing factors. Subsequently, the regression equations with the stability coefficient as the objective functions as well as the response surface for the stability coefficient could be obtained by analyzing the test results using the Design-Expert software. The variance analysis showed that among the 3 variables in the test, the plow tilt angle had the greatest influence on the tillage depth and tillage width stability coefficients, while the lift angle of the rotary blade had the least influence on the coefficients. The response surface analysis showed that with a fixed lift angle of the rotary blade of 69.5°, an optimal tillage depth stability coefficient of 91.7% could be obtained with traction angle and plow tilt angle of 23.7° and 26.8°, respectively. An optimal tillage width stability coefficient of 93.2% could be achieved with traction angle and plow tilt angle of 25.2° and 27.3°, respectively. The optimal parameter combination was traction angle of 17.3°, plow tilt angle of 27.8°, and rotary blade's lift angle of 72.6°. This optimal combination could achieve the working condition tillage depth stability coefficient of 91.8% and the tillage width stability coefficient of 93.4%, respectively. The validation experiments showed that with the optimal parameter combination of the influencing factors, the working condition tillage depth stability coefficient and the tillage width stability coefficient were 91.5% and 93.1%, respectively; these results were consistent with the ones obtained via software analysis. Other tillage performance indicators of the machine, such as tillage depth, tillage width, surface leveling degree, pulverization rate, and straw coverage rate which were respectively 1.87, 1.98, 21.20, 90.30% and 90.70%, all met the agronomic requirements. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:22
Main heading:Agricultural machinery
Controlled terms:Agriculture - Comminution - Convergence of numerical methods - Cultivation - Factor analysis - Optimization - Software testing - Stability - Surface analysis - Surface properties - Turbomachine blades - Vibration analysis
Uncontrolled terms:Instantaneous center of rotation - Optimal parameter combinations - Recombination - Response surface analysis - Rotary tillages - Tilling depth - Tilling width - Vibrational excitation
Classification code:723.5 Computer Applications - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 921.5 Optimization Techniques - 921.6 Numerical Methods - 922.2 Mathematical Statistics - 951 Materials Science
DOI:10.11975/j.issn.1002-6819.2016.09.001
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
<RECORD 21>
Accession number:20162002392065
Title:Algorithm to simulate concrete temperature control cooling pipe boundary based on heat flux integration
Authors:Zhu, Zhenyang (1); Liu, Minzhi (2); Qiang, Sheng (3); Xiang, Jianfang (1)
Author affiliation:(1) State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing, China; (2) Yinzhou District Quality and Safety Supervision Station of Water Conservancy Projects, Ningbo, China; (3) College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:83-89
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:When using the explicit iterative method to solve the temperature of mass concrete with cooling pipes, it is generally considered that the inner and outer surface of metal pipes can be neglected but the temperature difference cannot be neglected when using the plastic pipes. And the plastic pipes are usually regarded as the third boundary condition. For the past researchers, the coefficient of this kind of boundary condition can be got by experiment and inversion, which is yet expensive and may also not be reliable sometimes. To solve the problem, on the base of heat balance condition, a new calculation method is brought forward. It is well known that concrete is a poor conductor of heat, and there is a large temperature difference between the concrete and the cooling water. So, in the shell of a cooling pipe and the concrete near it, it can be assumed that the heat flux is only discharged by cooling water in the pipe and the direction of the temperature gradient is perpendicular to the cooling pipe surface. So, the heat fluxes passing through any circle (take the center pipe as the center of those circles) in the shell of the plastic pipe are equal. Based on these basic principles, the temperature of cooling pipe outer surface can be obtained by the heat flux of the concrete around the pipe, the thermal conductivity, the thickness of the pipe and the temperature of pipe inner surface. When using the conventional iterative method to solve the temperature of the mass concrete with cooling pipes, the iterative method should be used for the unknown water temperature distributions along the cooling pipes. For this new method, the temperature distributions along the inner surface of the pipes is also unknown, so the iterative method should be also used. With this new method, when using the conventional iterative method, the convergence speed is relatively low, or even can not converge. To solve this problem, the iterative algorithm is also improved. When the iteration time is (N-1) and N separately, it is assumed that the corresponding calculated temperature on the outer surface of the cooling pipe is T<inf>n-1</inf>and T<inf>n</inf>respectively. And then, when using 0.5 (T<inf>n-1</inf>+ T<inf>n</inf>) as the initial calculation condition for the (N+1)<sup>th</sup>time, the convergence of the iteration can be easily achieved. The convergence condition of the improved method was proved by mathematical deduction, and the deduction results showed that the convergence could be always reached in different engineering cases. A comparing numerical example was used to comparing the accuracy of the new method and the conventional explicit iterative method. In this comparing numerical example, the calculation results of the finite element method (FEM) considering the pipe as a part of mesh were considered as the theoretical solution. The calculation results showed that in the concrete near adiabatic boundary of the mesh in the comparing example, the temperature difference between the calculation result of conventional explicit iterative method and the theoretical solution was 1.67, and the temperature difference between the calculation result of improved method and the theoretical solution was only 0.3. So, the improved method can be more accurate than the conventional explicit iterative algorithm. Using these new achievements, the temperature field of a concrete block during construction period was simulated, and the calculation results and testing results were compared. The total number of the iteration times was 15 for the conventional iterative method and only 7 for the improved method in this engineering example. The results show that the calculation value is close to the actual value, and this algorithm has high convergence speed. So this method can be used in engineering projects to prevent mass concrete from cracking. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:22
Main heading:Iterative methods
Controlled terms:Algorithms - Boundary conditions - Concrete blocks - Concrete testing - Concretes - Cooling - Cooling water - Finite element method - Heat flux - Mesh generation - Models - Numerical methods - Plastic pipe - Temperature - Temperature distribution - Thermal conductivity
Uncontrolled terms:Calculation results - Concrete temperatures - Construction period - Convergence conditions - Iterative algorithm - Temperature differences - Theoretical solutions - Water temperature distribution
Classification code:412 Concrete - 619.1 Pipe, Piping and Pipelines - 641.1 Thermodynamics - 641.2 Heat Transfer - 921.4 Combinatorial Mathematics, Includes Graph Theory, Set Theory - 921.6 Numerical Methods
DOI:10.11975/j.issn.1002-6819.2016.09.012
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
<RECORD 22>
Accession number:20162002392059
Title:Improvement of tractor crankshaft properties by rapid high temperature salt bath nitriding
Authors:Dai, Mingyang (1); Tang, Wei (1); Sun, Fei (2, 3); Hu, Jing (1, 2)
Author affiliation:(1) Jiangsu Key Laboratory of Materials Surface Science and Technology, School of Materials Science and Engineering, Changzhou University, Changzhou, China; (2) Jiangsu Collaborative Innovation Center of Photovolatic Science and Engineering, Changzhou University, Changzhou, China; (3) Department of Mechanical Engineering, Changzhou Institute of Light Industry Technology, Changzhou, China
Corresponding author:Hu, Jing(jinghoo@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:40-44
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Salt bath nitriding is one of the most popular surface modification technologies to treat tractor's crankshaft for obtaining the required properties. Generally, several hours is needed to acquire the required layer depth in normal salt bath nitriding, and especially, it is almost impossible to get the required qualified deep layer depth due to the loose outermost surface layer formed at longer duration. Therefore, it is of significant value to improve its efficiency and get the required layer depth with good quality. In order to enhance the nitriding efficiency of tractor's crankshaft, AISI 1045 carbon steel, which is a type of common material used to produce tractor's crankshaft in industrial production, was selected as the testing material. Rapid salt bath nitriding was conducted at higher temperature of 660 instead of normally used 560. Then we compared normal salt bath nitriding with higher temperature salt bath nitriding for different nitriding time. Optical microscopy (OM), X-ray diffraction (XRD), micro-hardness testing and electrochemical workstation were employed for analyzing the microstructure, phase, micro-hardness and corrosion resistance of the tested material, respectively. The results show that compound layer (also called white layer) is formed at the outermost surface after salt bath nitriding under all conditions. The thickness of compound layer is only 3.8 μm nitrided at 560 for 20 min, which is too thin to effectively improve the surface hardness and corrosion resistance of AISI 1045 steel, and it is increased to 17.1 μm treated at higher temperature of 660 for 20 min, which is the same thickness as that nitrided at 560 for 140 min. Therefore, it can be concluded that higher temperature salt bath nitriding is much more efficient than normal salt bath nitriding. Meanwhile the main phases of compound layer are composed of Ε-Fe<inf>2-3</inf>N and γ'-Fe<inf>4</inf>N nitrided under different conditions. But the relative contents of Ε-Fe<inf>2-3</inf>N and γ'-Fe<inf>4</inf>N are different, which can be obtained by calculating the ratio of the strongest peak of γ'-Fe<inf>4</inf>N to the strongest peak of Ε-Fe<inf>2-3</inf>N. The ratio of γ'-Fe<inf>4</inf>N to Ε-Fe<inf>2-3</inf>N is 0.61 and 0.46 for higher temperature salt bath nitriding and normal temperature salt bath nitriding, respectively, which clearly shows that the relative content of γ'-Fe<inf>4</inf>N is more at higher temperature salt bath nitriding. Higher surface hardness and modestly higher sub-surface hardness are obtained with the same compound layer thickness after higher temperature salt bath nitriding. The maximum cross-sectional micro hardness of the AISI 1045 steel is increased from 702 to 784 HV<inf>0.01</inf>, which implies that the tractor's crankshaft made of AISI 1045 steel treated by higher temperature salt bath nitriding may have better wear resistance. Moreover, AISI 1045 steel treated by higher temperature salt bath nitriding shows higher corrosion potential of -993 mV and lower corrosion current of 0.302l A/cm<sup>2</sup>compared with that treated by normal temperature salt bath nitriding, which indicates that AISI 1045 steel treated by higher temperature salt bath nitriding has better corrosion resistance. The mechanism of high temperature salt bath nitriding process is that the decomposition rate of CNO<sup>-</sup>is greatly accelerated, and thus much more active nitrogen atoms can be produced in the salt bath media, plus the vacancy concentration in AISI 1045 steel is significantly increased at higher temperature. Therefore, a conclusion can be drawn that high temperature salt bath nitriding is possible to replace normal salt bath nitriding to further enhance the tractor's crankshaft made of AISI 1045 steel, since high temperature salt bath nitriding can not only shorten salt bath nitriding time, but also enhance the combined properties of tractor's crankshafts. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:22
Main heading:Nitriding
Controlled terms:Carbon - Carbon steel - Corrosion - Corrosion resistance - Crankshafts - Efficiency - Experiments - Hardness - Ionization of gases - Iron compounds - Stainless steel - Steel testing - Surface resistance - Surface treatment - Temperature - Tractors (agricultural) - Tractors (truck) - Wear resistance - X ray diffraction
Uncontrolled terms:Corrosion current - Corrosion potentials - Decomposition rate - Industrial production - Nitriding efficiency - Salt bath nitriding - Testing materials - Vacancy concentration
Classification code:537.1 Heat Treatment Processes - 539.1 Metals Corrosion - 545.3 Steel - 601.2 Machine Components - 641.1 Thermodynamics - 663.1 Heavy Duty Motor Vehicles - 802.2 Chemical Reactions - 804 Chemical Products Generally - 901.3 Engineering Research - 913.1 Production Engineering - 931.2 Physical Properties of Gases, Liquids and Solids - 951 Materials Science
DOI:10.11975/j.issn.1002-6819.2016.09.006
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
<RECORD 23>
Accession number:20162002392081
Title:Effects of different vegetation on soil nutrients remediation degree in earth disposal site after 16 a in mining area of Shanxi-Shaanxi-Inner Monglia adjacent region
Authors:Wang, Xiaolin (1); Wang, Limei (1); Zhang, Xiaoyuan (1); Ma, Jiangbo (1); Zheng, Jiyong (1, 2); Zhang, Xingchang (1, 2)
Author affiliation:(1) College of Natural Resources and Environment, Northwest A&F University, Yangling, China; (2) State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Insitute of Soil and Water Conservation, Chinese Academy of Sciences & Ministry of Water Resources, Yangling, China
Corresponding author:Zheng, Jiyong(zhjy@ms.iswc.ac.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:198-203
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Shanxi-Shaanxi-Inner Monglia adjacent region is an important coal energy base, and also the most fragile ecological region in China. Recent years, the large-scale opencast mining has heavily destroyed the original landscape and ecosystem, and formed a large number of earth disposal sites. To guaranty the harmonious development of the local society, economy and ecosystem, the rapid artificial vegetation reconstruction in these sites is the key part of the local ecological restoration. To evaluate the effects of different vegetation measures in the process of land reclamation on the recovery of soil nutrient, the east earth disposal site in Heidaigou opencast coal mine located in Jungar Banner, Inner Mongolia was chosen as studying area, where the land reclamation was carried out with 7 different artificial vegetation configuration modes (Astragalus adsurgens, Stipa bungeana, Amorpha fruticosa, Robinia pseudoacacia, Hippophae rhamnoides, Poplar and Pinus sylvestris var mongolica Litv) since 1996. The recovery degrees of soil total nitrogen (TN), soil organic carbon (SOC), NO<inf>3</inf><sup>-</sup>-N and NH<inf>4</inf><sup>+</sup>-N within 0-40 cm were studied by comparing with the nearby natural soil under 2 vegetation types (natural Stipa bungeana and natural Hippophae rhamnoides). The results showed that: 1) The content of TN, SOC, NO<inf>3</inf><sup>-</sup>-N and NH<inf>4</inf><sup>+</sup>-N declined with the increase of the soil depth within 0-40 cm under different vegetation except the Pinus sylvestris var mongolica Litv and Astragalus adsurgens. 2) Within 0-40 cm, the contents of TN and SOC of 7 artificial vegetation types were significantly lower than the 2 natural vegetation types, and there was no significant difference between 7 artificial vegetation types and 2 natural vegetation types in NH<inf>4</inf><sup>+</sup>-N within 0-10 and 20-40 cm. Seven vegetation types improved soil quality at different levels, and the remediation degree of Robinia pseudoacacia vegetation was better than other vegetation patterns. Average TN, SOC, NO<inf>3</inf><sup>-</sup>-N and NH<inf>4</inf><sup>+</sup>-N within 40 cm soil depth were recovered to 44.15%, 44.65%, 85.33% and 93.77% of natural Stipa bungeana site and 56.85%, 54.82%, 84.66% and 105.70% of natural Hippophae rhamnoides site after nearly 16 years' recovery. And the remediation effects of Poplar and Pinus sylvestris var mongolica Litv were no more than 40% of the 2 natural vegetation types. The remediation effect of NH<inf>4</inf><sup>+</sup>-N was relatively better under 7 vegetation patterns. Average NH<inf>4</inf><sup>+</sup>-N within 40 cm soil depth was recovered to 79.50%-93.77% of natural Stipa bungeana site, and 89.47%-105.7% of natural Hippophae rhamnoides site. However, the remediation degree of TN, SOC, and NO<inf>3</inf><sup>-</sup>-N were relatively lower than NH<inf>4</inf><sup>+</sup>-N. Average TN, SOC, and NO<inf>3</inf><sup>-</sup>-N within 40 cm soil depth had recovered to 24.70%-44.15%, 25.09%-44.65%, 47.25%-85.33% of natural Stipa bungeana site, and 33.52%-56.85%, 32.83%-54.82%, 47.18%-84.66% of natural Hippophae rhamnoides site. Although soil nutrients of 7 artificial vegetation modes in land reclamation area have not reach the natural level completely after 16 years' land reclamation, artificial vegetation is an effective measure to improve soil nutrients' recovery. Fabaceous plant vegetation (mainly Robinia pseudoacacia) was better than other vegetation patterns for soil nutrient recovery, so Robinia pseudoacacia, Hippophae rhamnoides and Stipa bungeana could be the suitable vegetation for the land reclamation in this area. The research has evaluated the soil nutrient remediation degree of different vegetation measures in the process of land reclamation and provided the theoretical basis for the vegetation measure selection during ecological restoration and land reclamation in the opencast coal mine area. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:20
Main heading:Land reclamation
Controlled terms:Coal - Coal mines - Coal reclamation - Ecology - Ecosystems - Forestry - Land use - Metal recovery - Nutrients - Organic carbon - Plants (botany) - Pollution - Reclamation - Recovery - Restoration - Soils - Value engineering - Vegetation
Uncontrolled terms:Artificial vegetation - Ecological restoration - Harmonious development - Hippophae rhamnoides - Pinus sylvestris var mongolica - Robinia pseudo-acacia - Soil nutrients - Soil total nitrogen
Classification code:403 Urban and Regional Planning and Development - 442.2 Land Reclamation - 454.3 Ecology and Ecosystems - 483.1 Soils and Soil Mechanics - 503.1 Coal Mines - 524 Solid Fuels - 804.1 Organic Compounds - 911.5 Value Engineering
DOI:10.11975/j.issn.1002-6819.2016.09.028
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
<RECORD 24>
Accession number:20162002392061
Title:Forward kinematics analysis and experiment of hybrid harvesting robot based on screw theory
Authors:Yang, Hanjiang (1); Li, Lijun (1); Gao, Zicheng (1)
Author affiliation:(1) School of Mechanical and Electrical Engineer, Central South University of Forestry and Technology, Changsha, China
Corresponding author:Li, Lijun(junlili1122@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:53-59
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In this paper, the research progress of the camellia oleifera fruit harvesting equipment was introduced. This paper simplified the structure of the 2P4R hybrid camellia oleifera fruit harvesting robot, which included waist part, arm part and wrist part. The manipulator could accomplish 6 kinds of movements including waist revolution, translational motion of vertical slider and horizontal slider, and 3 kinds of revolute motions of the wrist part. In arm part, the fore-arm is linked with back-arm by 2 components; one is link-bar below and the other is lower-arm above. Fore-arm is paralleled with back-arm and link-bar is paralleled with lower-arm. It means these 4 components form a parallel quadrilateral mechanism, which not only increases the stiffness of the arm part, but also can obtain larger end effector working space through a smaller drive stroke, and thus, the harvesting robot meets the requirements of large end effector working space when it clamps the camellia oleifera trunk. Robot can adjust the posture and position of the end effector by controlling the rotation of waist part and wrist part and the translation of arm part respectively. It makes the wrist part decrease by 2 degrees of freedom, lightens the burden of the arm, and also reduces the adverse effect of high-frequency vibration when the robot harvests camellia oleifera fruit. The screw theory and a kind of kinematics analysis method for hybrid robot were introduced. With the proposed method, firstly, the open chain from the waist part to the end effector of the manipulator was defined, which contained the vertical slider as major chain, and the kinematic analysis problem of hybrid robot was turned to the sub-problems of the kinematic analysis of an open major chain and a single closed chain; secondly, the kinematics equation of the closed chain and major chain was established, and then the conversion formula between the driving joint variable in closed chain and the passive joint variable in major chain was obtained by figuring out the equation of the closed chain; thirdly, the position of the end effector was got from the kinematics analysis of the closed chain by using the Lie group, Lie algebra, screw theory and product-of-exponential formula; and finally the positive kinematics equation for the position of the end effector was obtained from the synthesized results of the kinematic analysis of the major chain and closed chain. The first-order and second-order derivative of the position equation were the velocity equation and acceleration equation of the manipulator respectively. In order to verify the feasibility of the proposed method and the correctness of the kinematics equation, select a group of joint variable values, and then figure out the theoretical position coordinate of the end effector by putting the values into the kinematical equation in Matlab. A test platform for kinematics experiment was built, which consists of a three-dimensional position measuring instrument and a camellia oleifera fruit hybrid harvesting robot. The three-dimensional position measuring instrument was used to measure the actual position coordinates of the end effector directly, which was driven by the selected values. From the comparison between the theoretical and actual results, it was found that the maximum position error between kinematical equation resolution and actual position coordinate of the end effector was 10.4 mm, which was significantly smaller than 200 mm, the open size of the end effector. From the above experiment results, the correctness of the kinematics equation of the manipulator based on the proposed method was verified. Therefore, the application of the proposed method based on screw theory in kinematics analysis is beneficial for establishing the control method and trajectory planning. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:19
Main heading:End effectors
Controlled terms:Algebra - Chains - Degrees of freedom (mechanics) - Fruits - Group theory - Harvesting - Industrial robots - Kinematics - Lie groups - Manipulators - Models - Robots - Screws
Uncontrolled terms:Acceleration equations - Camellia oleifera fruits - Forward kinematics analysis - High frequency vibration - Hybrid robots - Kine-matical equations - Screw theory - Second order derivatives
Classification code:602.1 Mechanical Drives - 605 Small Tools and Hardware - 731.5 Robotics - 731.6 Robot Applications - 821.3 Agricultural Methods - 821.4 Agricultural Products - 921.1 Algebra - 931.1 Mechanics
DOI:10.11975/j.issn.1002-6819.2016.09.008
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
<RECORD 25>
Accession number:20162002392068
Title:Effects of precipitation and air temperature changes on yield of several crops in Eastern Gansu of China
Authors:Yang, Xuan (1); Wang, Zikui (1); Cao, Quan (1); Zhang, Xiaoming (1); Shen, Yuying (1)
Author affiliation:(1) College of Pastoral Agriculture Science and Technology, Key Laboratory of Grassland Agro-ecosystem, Lanzhou University, Lanzhou, China
Corresponding author:Shen, Yuying(yy.shen@lzu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:106-114
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Investigating the response of crop production to climate change can help to optimize local agricultural practices, and then ensure food and ecological security. Crop models can provide a useful way to examine the effects of a range of climatic condition, management or crop cultivar on crop growth and yield in field and pasture. This work investigated the effects of precipitation and air temperature changes on the production of winter wheat, maize and lucerne in rain-fed agriculture area located in the central and western Loess Plateau by field experiment and crop simulation model. The field experiment was conducted at Qingyang Loess Plateau Experimental Station of Lanzhou University through 2001 to 2010, and the Agricultural Production Systems Simulator (APSIM) was applied in this study to simulate the growing process of winter wheat, maize and lucerne. The APSIM was validated with the experimental data firstly, and then the APSIM was applied to simulate the yield variability of the crops under the combinations 5 precipitation levels and 5 air temperature levels based on historical climatic data from 1961 to 2010. Temperature levels were: 1) -1.5 decrease in daily mean temperature (T<inf>1</inf>); 2) -1 decrease in daily mean temperature (T<inf>2</inf>); 3) historical daily temperature (T<inf>2</inf>); 4) 1 increase in daily mean temperature (T<inf>4</inf>); and 5) 1.5 increase in daily mean temperature (T<inf>5</inf>). Precipitation levels were: 1) 20% decrease in daily precipitation (P<inf>1</inf>); 2) 10% decrease in daily precipitation (P<inf>2</inf>); 3) historical daily precipitation (P<inf>3</inf>); 4) 10% increase in daily precipitation (P<inf>4</inf>); and 5) 20% increase in daily precipitation (P<inf>5</inf>). Results showed that the APSIM can predict the grain yield and biomass of the 3 crops accurately with the determination coefficients varied between 0.80-0.93, the normalized root mean square errors varied between 11.35%-22.48%, and the model efficiency varied between 0.53-0.91; Overall, APSIM was powerful to simulate the crop grain yield and biomass of winter wheat, maize and lucerne in study site. Winter wheat and lucerne maintained the greatest yield increase when the air temperature decreased and the precipitation increased during 1961-2010, which was 29.8% and 51.7%. Maize reached its greatest yield, which improved 22% when the precipitation increased and the air temperature remained unchanged. The maximal reduction of yield of 3 crops were 38.7%, 40.3% and 41.8%, respectively, which presented in the scenarios with low precipitation level and high temperature level. In addition, the variation range of winter wheat yield was reduced by increasing air temperature and precipitation while lucerne yield exhibited a smaller variation range when precipitation decreased and temperature increased. According to the trend of winter wheat and lucerne, the variation range of maize yield tended to boost by increasing precipitation, otherwise, maize yield also showed a wider range under the temperature level varied from T<inf>1</inf>to T<inf>3</inf>; but when temperature level hoisted up the T<inf>5</inf>, variation range of maize yield tended to be narrower. Overer, lucerne could adapt to the climate change better than winter wheat and maize with relatively inferior changes of yield variation under different climatic scenarios. In conclusion, the 3 crops were more sensitive to precipitation and they had positive linear relationships with precipitation level by slopes of 14.3-16.0, 11.8-15.5 and 15.0-18.9, respectively. The results should offer better comprehension and consultation for future studies and actual production about long-term of chief crop production when climate changes. Future agricultural production should attach importance to change crop management such as sowing date and cultivar to avoid heat or moisture stress. Otherwise, more efforts should be paid to explore the effect of interaction by CO<inf>2</inf>, solar radiation, precipitation and air temperature on crop production on the western of Loess Plateau. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:40
Main heading:Climate change
Controlled terms:Agriculture - Atmospheric temperature - Carbon dioxide - Crops - Cultivation - Ecology - Forestry - Grain (agricultural product) - Landforms - Mean square error - Precipitation (chemical) - Precipitation (meteorology) - Rain - Sediments - Temperature
Uncontrolled terms:Agricultural production system - Agricultural productions - Air temperature changes - APSIM - Determination coefficients - Eastern Gansu - Root mean square errors - Yield
Classification code:443.1 Atmospheric Properties - 443.3 Precipitation - 454.3 Ecology and Ecosystems - 481.1 Geology - 483 Soil Mechanics and Foundations - 641.1 Thermodynamics - 802.3 Chemical Operations - 804.2 Inorganic Compounds - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 922.2 Mathematical Statistics
DOI:10.11975/j.issn.1002-6819.2016.09.015
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
<RECORD 26>
Accession number:20162002392055
Title:Working performance experiment of combination blade roller for straw returning in paddy field and dry land
Authors:Zhang, Xiumei (1); Xia, Junfang (1); Zhang, Jumin (1); He, Xiaowei (1); Liang, Shifang (1); Zhang, Shun (1); Wu, Hao (1); Wan, Song (1)
Author affiliation:(1) College of Engineering, Huazhong Agricultural University, Wuhan, China
Corresponding author:Xia, Junfang(xjf@mail.hza.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:9-15
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In transitory and busy farming season, the straw has to be buried in the field whether it's paddy or dry land. In this study, we designed a straw burying rotary tiller, which can bury crop straw not only in paddy field, but also in dry land. It is suitable for tillage in middle and lower reaches of Yangtze River, where the principal crop rotation is paddy field rice after dry land crop annually. In order to improve the working quality of the cultivating roller for straw returning in paddy field and dry land, the experimental studies have been conducted in the fields. First, L<inf>9</inf>(3<sup>4</sup>) orthogonal experiment was conducted to research the influence factors of the performance of the cultivator for straw returning. The main influence factors for working quality of rotary tiller were tillage depth, rotary speed and forward speed. The tillage depth of 15.5, 18.5 and 21.5 cm, the rotary speed of 314, 330 and 360 r/min, and the forward speed of 0.43, 0.69 and 0.93 m/s were selected. The results showed that among the above 3 factors the influence order was tillage depth>forward speed>rotary speed. The tillage depth affected straw coverage extremely significantly, the forward speed affected straw coverage extremely significantly, and the rotary speed didn't affect straw coverage obviously, but it affected soil crushing rate significantly. The better test conditions were shown as below: the forward speed was 0.43-0.93 m/s, the rotary speed was about 330 r/min, and the tillage depth was about 21.5 cm. Based on the better test conditions (the forward speed was selected as 0.43 m/s), the experiments on working performance of cultivator for straw returning in paddy field and dry land were conducted in the fields, and the wireless telemetry technology and the power output shaft torque sensor were used in the study. The results showed that the working qualities of cultivator which met the agro-technical requirement of rice sowing and transplanting were as follows: in paddy field, when the soil texture was clay loam, the soil water content was 42.6%, the height of straw was 78.9 cm, the tillage depth was about 150 mm and the soil compaction value was under 1 244.8 kPa, the vegetation coverage rate reached 94.3%, the tillage depth reached 20.8 cm, the stability of tillage depth was 92.3%, the field surface evenness was 0.9 cm, and the power consumption was 27.6 kW; in dry land, when the soil texture was loam, the soil water content was 25.8%, the height of wormwood was 97.2 cm, the tillage depth was 150 mm and the soil compaction value was under 2 310.5 kPa, the vegetation coverage rate reached 96.5%, the tillage depth reached 20.3 cm, the stability of tillage depth was 90.6%, the field surface evenness was 1.2 cm, and the power consumption was 31.2 kW. At the same time, the comparative tests between the combination blade roller and the spiral blade, the traditional rotary blade were also conducted, in which the new roller was in according with the national standard of the work quality. The results showed that the working quality of the combination blade roller was better than that of the spiral blade and the traditional rotary blade, and the power consumption of the combination blade roller was higher than that of the traditional rotary blade. Based on the above results, further research on the power consumption of the cultivator for straw returning in paddy field and dry land is needed. The results provide the basis for the structure optimization of the cultivator for straw returning and the improvement of its working performance, and also provide a suitable implement to achieve high stubble straw mulching and soil tillage in paddy field and dry land. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:24
Main heading:Agricultural machinery
Controlled terms:Agriculture - Compaction - Crops - Cultivation - Electric power utilization - Experiments - Optimization - Rollers (machine components) - Soil mechanics - Soil moisture - Soils - Speed - Structural optimization - Turbomachine blades - Vegetation
Uncontrolled terms:Combination blade roller - Dry land - Middle and lower reaches of yangtze rivers - Orthogonal experiment - Structure optimization - Technical requirement - Vegetation coverage - Working performance
Classification code:483.1 Soils and Soil Mechanics - 601.2 Machine Components - 706.1 Electric Power Systems - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 901.3 Engineering Research - 921.5 Optimization Techniques
DOI:10.11975/j.issn.1002-6819.2016.09.002
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
<RECORD 27>
Accession number:20162002392067
Title:Calibration and evaluation of R-K evapotranspiration model for winter wheat in North China Plain
Authors:Wang, Juan (1, 2); Wang, Jianlin (3); Liu, Jiabin (4); Jiang, Yongchao (2); Wang, Guodong (1)
Author affiliation:(1) College of Science, Northwest A&F University, Yangling, China; (2) College of Sciences and Information Science, Qingdao Agricultural University, Qingdao, China; (3) College of Agronomy and Plant Protection, Qingdao Agricultural University, Qingdao, China; (4) Department of Modern Agricultural Demonstration Farm, Qingdao Agricultural University, Qingdao, China
Corresponding author:Wang, Guodong(gdwang211@aliyun.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:99-105
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Understanding of evapotranspiration (ET) of crops is very important for the research on the balance of water, such as hydrology, agronomy and environmental science. The Penman-Monteith equation (PM equation) has been widely used for predicting the actual ET, but the direct application of the PM equation is very difficult because of the determination of canopy resistance. Two operational models are developed to determine the actual ET based on the PM equation: FAO-PM model (FAO is the abbreviation of Food and Agriculture Organization) and Rana and Katerji model (R-K model). To analyze the applicability and stability of these 2 models on predicting the ET from winter wheat field in the North China Plain, the dynamic variations of ET from winter wheat field in 2013-2014 and 2014-2015 were studied on the basis of the data obtained with eddy covariance system (EC) and microclimate observations. The applicability of the R-K model was also analyzed in the experimental field. The R-K model was calibrated and validated with the data obtained in winter wheat growing seasons during 2013-2014 and 2014-2015. The daily ET predicted by the R-K model and the FAO-PM model was compared to the observed ET with the EC method. The application of the R-K model in predicting the ET in different growing stages of winter wheat was further studied. Results indicated that the ET of winter wheat showed obvious seasonal variation, and the minimum daily ET occurred in late January (the value was nearly zero). With the advent of the returning green stage, the winter wheat entered the development stage, and the ET started to increase slowly, reaching the maximum that was 7.37 mm in May for 2013-2014 and 5.72 mm in April for 2014-2015. The minimum monthly ET occurred in January, which was 10.7 and 8.6 mm in 2013-2014 and 2014-2015, respectively; and the maximum monthly ET was 142.8 and 102.5 mm in May for 2013-2014 and 2014-2015, respectively. The total ET of whole growing season was 436.3 and 334.8 mm respectively for these 2 growing seasons. The coefficients a and b in the R-K model were calibrated by using 3 data sets (data in 2013-2014, data in 2014-2015, and data in both years). There was small difference between the 3 data sets, and the stability of the R-K model was good. The calibrated coefficients a and b by using the data in 2013-2014 were 1.277 and 0.540 respectively (R<sup>2</sup>=0.741 and RMSE=2.034×10<sup>-5</sup>) and taken as the calibrated coefficients suitable for the experiment field. The data in 2014-2015 were used to validate the performance of the model. In the FAO-PM model, the slope of the linear regression between the observed and predicted values (1.01) was slightly greater than 1.0, the coefficient of determination was higher than 0.85, the index of agreement was 0.90, and the relative error was 16.2%. In the revised R-K model, the slope of linear regression (0.89) was less than 1.0, the coefficient of determination was higher than 0.85, the index of agreement was 0.91 and the relative error was 6.95%. These statistical parameters indicated that predicting daily ET with the revised R-K model performed slightly better than the FAO-PM model. To guide the management of the field irrigation, the ET during different growing stages was predicted with the R-K model. The performance of the model was much better in late-season stage with the relative error less than 0.5%, followed by the development stage with the relative error of about 19%, and then the mid-season stage with the relative error of about 21%, and poor for the initial stage and the overwintering stage with the relative error value of about 48% and 92%, respectively. The sensitivity analysis indicated the R-K model had good stability because it was only slightly sensitive to the aerodynamic resistance and the critical resistance. Overall, the R-K model is a promising model to predict the actual ET, and the calibration and validation of the model need further study at hourly, daily, monthly and annual time scales in different locations. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:46
Main heading:Crops
Controlled terms:Aerodynamic stability - Agriculture - Calibration - Errors - Evapotranspiration - Forecasting - Models - Sensitivity analysis
Uncontrolled terms:Calibration and validations - Coefficient of determination - Eddy covariance method - Eddy covariance systems - Evapotranspiration modeling - Food and agriculture organizations - Meteorological parameters - Penman-Monteith equations
Classification code:651 Aerodynamics - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.4 Agricultural Products - 921 Mathematics
DOI:10.11975/j.issn.1002-6819.2016.09.014
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
<RECORD 28>
Accession number:20162002392091
Title:Technology optimization of Medicago sativa leaf protein separation with foam fractionation
Authors:Liu, Haibin (1); Zhang, Wei (1); Chen, Yuantao (1); Gao, Zhongchao (1); Liu, Long (1)
Author affiliation:(1) Department of Chemistry, Qinghai Normal University, Xining, China
Corresponding author:Zhang, Wei(zhangwei@qhun.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:271-276
Language:English
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to purify Medicago sativa leaf protein effectively, foam fractionation which could increase both enrichment ratio and recovery of Medicago sativa leaf protein, was developed based on the research of the influences of initial pH value, the air flow rate, the loading liquid volume and the ratio of material to solvent. Then the best single factor was defined which was the loading liquid volume of 550 mL, pH value of 6.5, the ratio of material to solvent of 87.5 mg/L, the air flow rate of 250 mL/min. Based on the single factor experiment, Box-Behnken design was adopted to investigate the influence of four factors: pH value, the loading liquid volume, concentration and the air flow rate on recovery and enrichment ratio of leaf protein from Medicago sativa. Response surface and contour plots were finally graphed with the recovery and enrichment ratio as the response value. The foam fractionation of leaf protein from Medicago sativa was optimized by response surface methodology. The model P-value were both smaller than 0.0001 and the model were goodness-of-fit and the adequacy of the regression model. The optimum conditions for the foam fractionation of leaf protein from Medicago sativa were found to pH value of 6.92, the ratio of material to solvent of 87.5 mg/L, the loading liquid volume of 600 mL, the air flow rate of 200 mL/min. Under the conditions, the recovery of Medicago sativa leaf protein was 92.2% and the enrichment ratio was 8.03. Considering actual process, The optimization processes were pH value of 7.0, the ratio of material to solvent of 87.5 mg/L, the loading liquid volume of 600 mL, the air flow rate of 200 mL/min. The recovery of Medicago sativa leaf protein was 90.2% and the enrichment ratio was 7.64. respectively. The experimental results showed that foam fractionation was an effective method to separate leaf protein from Medicago sativa. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:23
Main heading:Loading
Controlled terms:Air - Flow rate - Fractionation - Liquids - Optimization - pH - Plants (botany) - Proteins - Recovery - Regression analysis - Solvents - Surface properties - Technology
Uncontrolled terms:Box-Behnken design - Enrichment ratio - Foam fractionation - Medicago sativa - Optimum conditions - Response surface methodology - Single-factor experiments - Technology optimization
Classification code:631 Fluid Flow - 691.2 Materials Handling Methods - 801.1 Chemistry, General - 802.3 Chemical Operations - 803 Chemical Agents and Basic Industrial Chemicals - 804 Chemical Products Generally - 804.1 Organic Compounds - 921.5 Optimization Techniques - 922.2 Mathematical Statistics - 951 Materials Science
DOI:10.11975/j.issn.1002-6819.2016.09.038
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
<RECORD 29>
Accession number:20162002392074
Title:Three dismensional appearance simulation of plant leaves based on multiple images with light source change
Authors:Miao, Teng (1, 2, 3, 4, 5); Guo, Xinyu (1, 2, 3, 4); Zhao, Chunjiang (1, 2, 3, 4); Xiao, Boxiang (1, 2, 3, 4); Wang, Chuanyu (1, 2, 3, 4); Wen, Weiliang (1, 2, 3, 4)
Author affiliation:(1) Beijing Research Center for Information Technology in Agriculture, Beijing, China; (2) National Engineering Research Center for Information Technology in Agriculture, Beijing, China; (3) Key Laboratory for Information Technology in Agriculture, Ministry of Agriculture, Beijing, China; (4) Beijing Key Lab of Digital Plant, Beijing, China; (5) College of Information and Electrical Engineering, Shenyang Agricultural University, Shenyang, China
Corresponding author:Zhao, Chunjiang(zhaocj@nercita.org.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:150-156
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Three-dimensional (3D) Plant modeling and visualization is a key research issue in both digital plant and agricultural application. Leaf is one of the vital organs in a plant, so the 3D modeling and shading of plant leaves is an important and fundamental work for achieving the goals of digital plant. Appearance simulation of plant leaves is still a challenging issue because of its intricate underlying structure and complex and subtle interaction with light. Texture mapping using leaf photo is a common method for appearance simulation, however, it could bring noise caused by light environment and camera position in lighting simulation step. This paper presents a technique for simulating the appearance of plant leaves with multiple images. Our method can estimate the spatially-varying reflectance properties of plant leaf surface based on a few images, which capture leaves' appearance transition information with different light directions. An apparent image acquisition system using linear light source is built for capturing 400 images with a fixed camera viewpoint and a single direction of motion for the linear light source. This system is composed of a driving module, a linear source module, a background module and a camera. Using a linear light rather than a point light source as the illuminant, we can obtain a piece of area with more intensive illumination. With these image data, we develop a fitting method, which is able to estimate the diffuse color, specular color and specular roughness of each point on the leaf surface. In our method, the isotropic ward model is utilized as the appearance model for specifying that how the leaf surface reflects light. Our fitting technique first simulates the change of reflectance attributes of diffuse and specular reflectance lobes under moving linear light source. In this process, a rectangle is employed to simulate the linear light source and Monte Carlo integration method is used to calculate the radiation transmission process. When we have the simulating results, the appearance parameters of each pixel are determined by comparing its actual parameter values to the simulating results. By above fitting method, 3 kinds of spatially-varying appearance parameters are saved into 3 parameter images for rendering leaf appearance. For quickly shading, multipoint point light sources are used for simulating various illumination conditions instead of complex radiative transfer integral. Using appearance parameter images and shading method, static appearance or dynamic appearance transition of plant leaves can be generated realistically. From the results obtained by this method, we find that it can render more accurate and real appearance texture of leaves compared to traditional texture mapping methods. The advantages of our method are that the appearance parameter images for rendering have removed the light and viewport noise, and only contained the appearance material information. In order to prove this conclusion, we quantitatively analyze the reason for this advantage by some formula derivations in this paper. But for obtaining these advantages, our method needs more complex data acquisition process and parameter fitting algorithm, which will reduce the efficiency of simulation. For improving the efficiency of our method, 2 approaches are discussed in this paper, including reducing image resolution and fitting the specular parameters of the whole leaf by a few sample points. Our method can estimate some appearance parameters which are plant leaf own intrinsic properties. We believe this characteristic will make these appearance parameters used not only for visualization, but also as some important phenotypes instead of so-called color data. In the future work, we will extend the application of our method in agriculture, such as monitoring plant growth status with the appearance parameters, or analyzing the differences among plant varieties. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:26
Main heading:Mapping
Controlled terms:Agriculture - Cameras - Color - Data acquisition - Data visualization - Efficiency - Flow visualization - Image acquisition - Image resolution - Light sources - Monte Carlo methods - Plants (botany) - Reflection - Rendering (computer graphics) - Three dimensional computer graphics - Visualization
Uncontrolled terms:Appearance modeling - Digital plant - Efficiency of simulations - Image acquisition systems - Leaf - Light resources - Monte Carlo integration method - Various illumination conditions
Classification code:405.3 Surveying - 631.1 Fluid Flow, General - 723 Computer Software, Data Handling and Applications - 723.2 Data Processing and Image Processing - 741.1 Light/Optics - 742.2 Photographic Equipment - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 913.1 Production Engineering - 922.2 Mathematical Statistics
DOI:10.11975/j.issn.1002-6819.2016.09.021
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
<RECORD 30>
Accession number:20162002392062
Title:Design and performance test of one-body purification muffler of single cylinder diesel engine
Authors:Liu, Shengji (1); Zeng, Jinjin (1); Wang, Jian (1); Wang, Yunlong (2); Xie, Minghua (2)
Author affiliation:(1) School of Automotive and Traffic Engineering, Jiangsu University, Zhenjiang, China; (2) Wuxi Worldbest KAMA Power CO.LTD., Wuxi, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:60-66
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The large production of the single diesel engine is the characteristic of China internal combustion engine industry. But the environmental pollution is more serious and the large quantity of the single diesel engine is one of the main pollution sources. The exhaust after-treatment is a good measure of the diesel engine to reduce the emissions. In order to improve the emission performance of single cylinder diesel engine through external purification, the one-body purification muffler was designed. The functions of the one-body purification muffler were noise elimination and emission purification. The internal velocity uniformity was one of the most important aspects of the structure design of the one-body purification muffler. Numerical simulation and performance test were adopted in the structure design and performance optimization of the one-body purification muffler to optimize the catalytic performance, acoustic performance, aerodynamic performance and structural performance. Numerical simulation was used to analyze the internal airflow velocity field of one-body purification muffler to optimize the internal structure. The reasonable internal structure of the one-body purification muffler could effectively improve the catalytic conversion efficiency and the service life. Performance test was used to analyze the catalytic performance, acoustic performance and aerodynamic performance of the one-body purification muffler. According to the results of the performance test, the internal structure of the one-body purification muffler was improved. The results of overall performance test showed that the test prototype with the third scheme of one-body purification muffler had the advantages of low power loss, low flow resistance and high noise elimination. The power loss of the one-body purification muffler based on the third scheme was 1.18%, which was reduced by 28.5% compared with the original muffler. The flow resistance of one-body purification muffler based on the third scheme was lower than the original muffler. With the third scheme of one-body purification muffler, the engine noise was 108.6 dB, which remained the same compared with the original muffler. The results of overall emission test showed that the test prototype with the third scheme of one-body purification muffler had the advantage of low exhaust emission value. The measured values of carbon monoxide (CO), hydrocarbon (HC) and particulate matter (PM) were 0.94, 0.46 and 0.4 g/kW·h respectively, which were reduced by 85.4%, 70.5% and 28.6% respectively, compared with the original muffler. But the measured value of nitrogen oxide (NO<inf>x</inf>) remained the same compared with the original muffler. Besides, the measured values of CO, HC and PM of the third scheme of one-body purification muffler were reduced by 21.0%, 25.8% and 7.0% respectively compared with the second scheme of one-body purification muffler because of the optimizations of the aerodynamic performance and the structural performance. After the endurance test, the exhaust emission values of the third scheme of one-body purification muffler still met the third phase limits. The third scheme of one-body purification muffler can improve the emission performance of single cylinder diesel engine through external purification effectively and optimize the catalytic performance, the acoustic performance, the aerodynamic performance and the structural performance. The research provides theoretical and technical references for the design of the one-body purification muffler of the single diesel engine. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:16
Main heading:Diesel engines
Controlled terms:Acoustic noise - Aerodynamics - Air - Carbon - Carbon monoxide - Design - Emission control - Engine cylinders - Engines - Hydrocarbon refining - Internal combustion engines - Mufflers - Nitrogen oxides - Numerical models - Pollution - Purification - Testing - Velocity
Uncontrolled terms:Aero-dynamic performance - Catalytic conversion efficiencies - Environmental pollutions - Exhaust aftertreatment - Performance - Performance optimizations - Single-cylinder diesel engine - Structural performance
Classification code:451.2 Air Pollution Control - 513.1 Petroleum Refining, General - 612 Engines - 651.1 Aerodynamics, General - 751.4 Acoustic Noise - 804 Chemical Products Generally - 804.2 Inorganic Compounds - 921 Mathematics
DOI:10.11975/j.issn.1002-6819.2016.09.009
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
<RECORD 31>
Accession number:20162002392095
Title:Analysis on spatial spillover effect and influence factors of grain yield per hectare at county level in Huang-Huai-Hai region
Authors:Liu, Yu (1, 2, 3, 4); Tang, Xiumei (1, 2, 3, 4); Pan, Yuchun (1, 2, 3, 4); Tang, Linnan (1, 2, 3, 4)
Author affiliation:(1) Beijing Research Center for Information Technology in Agriculture, Beijing, China; (2) National Engineering Research Center for Information Technology in Agriculture, Beijing, China; (3) Key Laboratory of Agri-informatics, Ministry of Agriculture, Beijing, China; (4) Beijing Engineering Research Center of Agricultural Internet of Things, Beijing, China
Corresponding author:Pan, Yuchun(panyc@nercita.org.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:299-307
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:As an important grain production base of China, Huang-Huai-Hai region is of great significance for the steady grain supply of the country. Under the strategic background of regional cooperative development, the spatial externality of grain yield per hectare has attracted increasing attention. In order to investigate the spillover effects of grain yield per hectare at county level, this study focuses on the 347 counties of Huang-Huai-Hai region by Markov Chain method and Spatial Markov Chain method, and reveals the spatial spillover effect of grain yield per hectare at county level during 1980-2010 as well as the influential factors of the differentiation of grain yield in 1995 and 2010. And the results show: 1) During 1980-2010, the type of grain yield per hectare at county level in Huang-Huai-Hai region transfers in a gradual and smooth way, with a low probability of large-scale crossing. 2) During 1980-1995, the likelihood ratio statistic is 52.198, passing the Chi-square test with the significance level of 0.01, and is 55.147, passing the Chi-square test with the significance level of 0.005 during 1995-2010. That is to say the regional background type exerts significant impact on the type shifting of grain yield per hectare, and it's more significant in the second stage. The growth of grain yield per hectare of the counties at medium-low or medium-high level is similar, while the counties with high yield and low yield under the action of the regional context, gradually change toward middle type. Taking the counties adjacent to the high grain yield for example, their grain yield types per hectare will have a relative high possibility to increase, and vice versa. 3) In the aspect of spatial pattern of evolution, the type of grain yield per hectare tends to increase in the plain, and reduce obviously in the municipal districts and the coastal area. However, the type of grain yield per hectare in Jiangsu, Henan and Shandong Province gradually transfers to be stable. 4) Variations like grain yield per unit area in the last stage, average net income of peasant, industrial structure and ratio of effective irrigated areas have great impacts on the differentiation of grain yield per hectare at county level. And the influencing direction and degree of the factors in 1995 and 2010 are significantly different. In 1995, grain yield per hectare in the last stage, average net income of peasant, ratio of effective irrigated areas and industrial structure have passed the test of the significance level of 0.01, separately, and these indices are significantly positive to promote the grain yield; in 2010, the index of grain yield per hectare in the last stage, average net income of peasant and plant structure goes through the significant test, and the significance level is 0.01, 0.01 and 0.05, respectively. Except the average net income of peasant, the rest both play a positive role in promoting the overflow yield. These results can provide scientific ground for the optimization of grain production and policy-making to increase the grain yield per hectare in Huang-Huai-Hai region. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:33
Main heading:Grain growth
Controlled terms:Chains - Grain (agricultural product) - Markov processes - Models - Optimization - Statistical tests
Uncontrolled terms:Huang-Huai-Hai region - Industrial structures - Likelihood ratio statistics - Significance levels - Spatial externalities - Spatial lag models - Spillover effects - Yield per hectare
Classification code:602.1 Mechanical Drives - 821.4 Agricultural Products - 921.5 Optimization Techniques - 922.1 Probability Theory - 922.2 Mathematical Statistics - 933.1.2 Crystal Growth
DOI:10.11975/j.issn.1002-6819.2016.09.042
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
<RECORD 32>
Accession number:20162002392071
Title:Effects of different straw return modes on contents of soil organic carbon and fractions of soil active carbon
Authors:Li, Xinhua (1); Guo, Honghai (2); Zhu, Zhenlin (1); Dong, Hongyun (1); Yang, Liping (1); Zhang, Xijin (1)
Author affiliation:(1) Shandong Institute of Agricultural Sustainable Development, Ji'nan, China; (2) Institute of Resource and Environment, SAAS, Ji'nan, China
Corresponding author:Guo, Honghai(honghaig@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:130-135
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:To assess the effects of different straw return modes on the content of soil organic carbon and the fraction of soil active carbon, we investigated 4 different straw return modes, non-straw return (CK), direct straw return (CS), straw return after mushroom cultivation (CMS), and straw return after livestock digestion (CGS) using field plot experiment. The results showed that different straw return modes all increased the content of soil organic carbon, but the increases in soil organic carbon content by different straw return modes did not exhibit significant difference (P>0.05). The increases in soil organic carbon content were found in the order of CGS > CMS > CS > CK. In comparison to CK mode, the contents of soil organic carbon with CS, CMS and CGS modes increased by 9.0%, 23.9% and 26.7%, respectively. In addition, different straw return modes all improved the content of soil active carbon. Under different straw return modes, the contents of dissolved organic carbon (DOC) were in the order of CS > CMS > CGS > CK, and significant differences were observed among different return modes (P<0.01). Compared to CK mode, the contents of DOC in the treatments of CS, CMS and CGS increased by 64.6%, 29.4% and 8.9%, respectively. The contents of microbial biomass carbon (MBC) followed the order of CMS > CGS > CS > CK, and their differences were significant (P<0.05). The contents of MBC in the treatments of CS, CMS and CGS increased by 28.9%, 84.7%, and 59.3%, respectively, compared to the CK treatment. Similarly, the contents of soil easily oxidizable carbon (EOC) were in the order of CMS > CS > CGS > CK, and their differences were significant (P<0.01). Compared to CK mode, the contents of EOC in the treatments of CS, CMS and CGS increased by 24.1%, 55.7%and 9.3%, respectively. Straw return modes also significantly affected the fraction of soil active carbon in the soil total organic carbon (TOC) and changed the quality of soil organic carbon. Under different straw return modes, the ratios of DOC/TOC, MBC/TOC and EOC/TOC were in the orders of CS > CMS > CK > CGS, CMS > CGS > CS > CK and CMS > CS > CK > CGS, respectively. From the perspective of improving soil quality, CMS is the recommended mode, which has the greatest ratios of MBC/TOC and EOC/TOC, as well as a higher soil carbon effectiveness that facilitates the carbon utilization by the microorganisms, thus benefiting the growth of crops. On the other hand, from the perspective of soil carbon sequestration, CGS is the recommended mode, which has the lowest fraction of DOC/TOC and the highest content of soil organic carbon, thus facilitating the carbon sequestration. The results of the study can provide the basic data for the rational and efficient utilization of straw, as well as the improvement of the quality of agricultural soil carbon pool. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Organic carbon
Controlled terms:Agriculture - Carbon - Cultivation - Forestry - Soils - Straw
Uncontrolled terms:Active carbon - Carbon sequestration - Dissolved organic carbon - Microbial biomass carbon - Mushroom cultivation - Soil carbon sequestration - Soil organic carbon content - Total Organic Carbon
Classification code:483.1 Soils and Soil Mechanics - 804 Chemical Products Generally - 804.1 Organic Compounds - 821 Agricultural Equipment and Methods; Vegetation and Pest Control
DOI:10.11975/j.issn.1002-6819.2016.09.018
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
<RECORD 33>
Accession number:20162002392092
Title:Purification, antioxidant, hygroscopicity and moisture retention activity of low molecular weight polysaccharide from Litchi chinensis
Authors:Jing, Yongshuai (1); Zhang, Danshen (1); Wu, Lanfang (2); Rong, Xinyu (1); Du, Hongxia (1); Xu, Weitao (1)
Author affiliation:(1) College of Chemistry and Pharmaceutical Engineering, Hebei University of Science and Technology, Shijiazhuang, China; (2) College of Pharmacology, Hebei University of Chinese Medicine, Shijiazhuang, China
Corresponding author:Wu, Lanfang(wulanfang757@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:277-283
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Litchi (Litchi chinensis Sonn.), a tropical/subtropical fruit originally from China, is cultivated all over the world with warm climates. It has become one of the most popular fruits in the world due to its delicious flavor and abundant nutrition. As a good source of minerals, dietary fiber, and phytochemicals, litchi has been employed in traditional Chinese medicine. In addition, litchi has also been used to produce various types of health products and foods, such as medicinal beverages, drinks, or soups. Litchi fruit's pericarp tissues contain a lot of flavonoids, polysaccharides, and various proteins. Polysaccharides are a kind of biomacromolecules composed of more than 10 monosaccharide units, which generally exist in plants, animals, algae and microorganisms such as fungi and bacteria. Some investigations have indicated that Litchi chinensis polysaccharides have strong antioxidative activity and can be explored as novel potential antioxidants. Plant polysaccharides are excellent candidates for health and therapeutics, and searching for polysaccharides with antioxidant activity from plant resources has become a hot research topic. Furthermore, the polysaccharides exhibit good hygroscopicity and moisture retention activity due to the presence of a large number of hydroxyl or carboxyl polar groups, which can form hydrogen bonds with water molecules and cross-linked reticular structure. Antioxidant activity and hygroscopicity and moisture retention activity are important for healthcare to protect mankind from the attack of free radicals and retard the initiation of many chronic diseases. Therefore, it is necessary to more effectively purify and determine the physicochemical properties of polysaccharides from Litchi chinensis. In the current research, crude polysaccharides were extracted from Litchi chinensis to obtain the polysaccharide fraction (PLC). PLC was further purified and a kind of homogenous hetero polysaccharide (PLC-1) was isolated. The physicochemical properties, antioxidant activity, hygroscopicity and moisture retention activity of PLC-1 were analyzed. The polysaccharides of Litchi chinensis were extracted and purified by ultrasonic-assisted extraction, alcohol precipitation, deprotein, decolouring, dialysis, DEAE-cellulose 52 and Sephadex G-100 gel column chromatography. Purity was determined by ultraviolet-visible spectral scanning, spin spectrophotometry and gel filtration chromatography (GPC). The relative molecular mass was determined by high-performance gel permeation chromatography. The monosaccharide composition was analyzed by HPAEC-PAD. The antioxidant activity was evaluated on the basis of DPPH, OH free radical scavenging activity. The hygroscopicity and moisture retention activity was evaluated by adopting the in vitro method. PLC-1 was isolated and purified from Litchi chinensis, which was a kind of homogeneous polysaccharide. The relative molecular mass of PLC-1 was 2.35×10<sup>4</sup>Da. The monosaccharide of PLC-1 included galactose, rhamnose and glucose with a molar ratio of 1.00:3.52:5.89. The antioxidant activity showed PLC-1 had a good dose-effect relationship on DPPH radical and hydroxyl radical in a certain concentration range, and the 50% inhibiting concentration (IC<inf>50</inf>) of DPPH and hydroxyl radical scavenging activity was 0.41 and 0.31 mg/mL, respectively. The hygroscopicity and moisture retention activity indicated PLC-1 had good effect. Due to the physicochemical properties, antioxidant activity, hygroscopicity and moisture retention activity, PLC-1 has a good prospect in the preparation of functional food and cosmetics. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:25
Main heading:Antioxidants
Controlled terms:Agents - Beverages - Chromatography - Column chromatography - Extraction - Filtration - Free radicals - Fruits - Gel permeation chromatography - Glucose - Hydrogen bonds - Ion exchange - Medicine - Moisture - Molecular mass - Molecules - Nutrition - Polysaccharides - Purification - Spinning (fibers)
Uncontrolled terms:Anti-oxidant activities - Free radical scavenging activity - Gel-filtration chromatography - High performance gel permeation chromatography - Litchi chinensis - Moisture retention - Physicochemical property - Ultrasonic-assisted extractions
Classification code:461.6 Medicine and Pharmacology - 461.7 Health Care - 801 Chemistry - 801.4 Physical Chemistry - 802.2 Chemical Reactions - 802.3 Chemical Operations - 803 Chemical Agents and Basic Industrial Chemicals - 804.1 Organic Compounds - 819.3 Fiber Chemistry and Processing - 821.4 Agricultural Products - 822.3 Food Products - 931.3 Atomic and Molecular Physics
DOI:10.11975/j.issn.1002-6819.2016.09.039
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
<RECORD 34>
Accession number:20162002392089
Title:Effects of coating and heat treatments on energy levels and physiological indexes and qualities of grape fruits during storage
Authors:Zhang, Qun (1, 2); Zhou, Wenhua (1); Tan, Huan (2); Yang, Mingzhi (3); Liu, Xixia (4)
Author affiliation:(1) Food Science and Engineering, Central South University of Forestry Science and Technology, Changsha, China; (2) Hunan Agricultural Sciences Academy of Agricultural Products Processing Institute, Changsha, China; (3) Changsha County First Senior High School in Hunan Province, Changsha, China; (4) Key Laboratory of Wild Plant Resources in Hubei Province, Huangshi, China
Corresponding author:Zhou, Wenhua(13786129879@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:255-263
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Harvested grape fruit tissues are still alive. Grape fruit tissues still have metabolism including physiological and biochemical reactions. They are prone to physiological deterioration, such as texture softening, browning, decay and mildew. More and more studies have indicated that senescence and cell membrane permeability of horticultural crops may be related to energy deficit caused by the decline of energy synthesis. Changes of energy levels in grape fruit tissues during storage have not been reported. Effects of energy level on physiological quality of grape fruit tissues after coating and heat treatment with Ca<sup>2+</sup>are not clear. In this paper, the effects of coating and heat treatments with Ca<sup>2+</sup>on post-harvest energy levels and physiological deterioration of "Victoria" grape fruit during cold storage were explored through determining energy levels and physiological indices. Coating and heat treatments with Ca<sup>2+</sup>were applied to post-harvest grape fruits (compared with untreated grape fruits, i.e. the CK treatment). Grape fruits after coating and heat treatments with Ca<sup>2+</sup>were stored at (4±0.5). Respiratory rate, browning index, decay rate, hardness, contents of malondialdehyde (MDA), adenosine triphosphate (ATP), adenosine diphosphate (ADP) and adenosine monophosphate (AMP), energy charge (EC), and enzyme activities of polyphenol oxidase (PPO), peroxidase (POD), lipoxygenase (LOX) and soperoxide dismutase (SOD) of grape fruits were tested every 10 days. Results showed that with the extension of storage time, energy levels were in a loss state for grape fruit tissue under the CK. Respiratory rate decreased, but cell membrane oxidation and permeability increased. Browning index and decay rate increased, and enzyme activities of POD, PPO and LOX increased too, but enzyme activities of SOD were decreased. Physiological qualities of grape fruits decreased, and fruits were softened. Calcium combined with heat and coating treatment reduced the loss of grape fruits by rotting during storage. In addition, treatment of heat and coating with Ca<sup>2+</sup>could maintain higher energy status, energy charge, hardness and enzyme activities of SOD to keep qualities of grape fruit, delay grape fruit softening, inhibit respiratory intensity and accumulation of membrane lipid peroxidation, slow down growth of cell membrane permeability, decrease MDA content, inhibit enzyme activities of POD, PPO and LOX, and delay browning and rotting, aging process and physiological quality deterioration of grape fruits. But coating treatment was better than heat treatment. ATP was significantly positive correlation with hardness and SOD enzyme activity (r=0.938,0.930, P<0.01), but negative correlation with MDA membrane permeability and LOX enzyme activity (r=-0.896,-0.932,-0.940, P<0.01). EC was negative correlation with membrane permeability and LOX enzyme activity (P<0.05), but positive correlation with respiration intensity and SOD enzyme activity (P<0.05). Browning of grape fruits was closely related to membrane lipid peroxidation and membrane structure (the integrity of membrane structure was destroyed). PPO and POD were reacted with phenolic substrates to form brown pigment. Results showed that with the extension of storage time, energy levels of grape fruits were in a loss state. Fall of energy level significantly affected oxidation and integrity of cell membrane. Coating and heat treatments with Ca<sup>2+</sup>could maintain higher energy levels of ATP and ADP, and EC, which could slow down aging and physiological quality deterioration of grape fruit tissues. Coating and heat treatments with Ca<sup>2+</sup>may maintain high energy status and physiological qualities, and slow down aging and physiological quality deterioration of grape fruits tissues. Effects of coating treatment with Ca<sup>2+</sup>were better than heat treatment with Ca<sup>2+</sup>. Slowing down physiological deterioration of grape fruits can be realized by maintaining high energy status and preventing development of physiological deterioration. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:21
Main heading:Fruits
Controlled terms:Adenosinetriphosphate - Cells - Coatings - Cold storage - Cytology - Decay (organic) - Deterioration - Electron energy levels - Energy storage - Enzyme activity - Enzymes - Hardness - Heat treatment - Histology - Lipids - Membrane structures - Membranes - Oxidation - Phosphates - Physiology - Quality control - Tissue
Uncontrolled terms:Adenosine monophosphate - Biochemical reactions - Cell membrane permeability - Coating treatment - Grape fruit - Membrane lipid peroxidation - Physiological indices - Quality deteriorations
Classification code:461.2 Biological Materials and Tissue Engineering - 461.9 Biology - 525.7 Energy Storage - 537.1 Heat Treatment Processes - 644.3 Refrigeration Equipment and Components - 802.2 Chemical Reactions - 804.1 Organic Compounds - 813.2 Coating Materials - 821.4 Agricultural Products - 913.3 Quality Assurance and Control - 951 Materials Science
DOI:10.11975/j.issn.1002-6819.2016.09.036
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
<RECORD 35>
Accession number:20162002392090
Title:Effect of sterilization methods on volatile flavor compounds of instant carrot slices
Authors:Mi, Ruifang (1); Liu, Junmei (1); Hu, Xiaosong (1); Wu, Jihong (1)
Author affiliation:(1) China Agricultural University, Key Laboratory of Fruits and Vegetables Processing, Ministry of Agriculture, Beijing, China
Corresponding author:Wu, Jihong(wjhcau@hotmail.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:264-270
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The purpose of this paper was to study the effect of 3 different sterilization methods on the flavor of prepared carrot slices from raw materials during cold storage at 4. The samples were pretreated by pasteurization (90, 30 min), high hydrostatic pressure sterilization (550 MPa, 25, 10 min), pressure-assisted thermal sterilization (550 MPa, 50, 10 min) and stored at 4 for 60 d. The solide-phase micro-extraction (SPME)/chromatography-mass spectrometry (GC-MS) technology was used to detect and analyze the volatile flavor compounds in fresh carrot and sterilized carrot slices during storage. Results showed that carrots had a complex volatile characteristic. Fresh carrot sample's volatiles mainly consisted of terpenes, esters, aldehydes, alcohols, ketones and alkanes. Among these, terpenes were considered to be the most important volatile compounds, such as α-terpinene, terpinolene, β-caryophyllene, β-pinene and D-limonene, which impart the characteristic aroma of fresh carrots. First, a comparison was made between the untreated carrots, pasteurizated carrots, high hydrostatic pressure treated carrots and pressure-assisted thermal treated carrots. In the second step, the volatile compounds of different processing were compared in shelf life of 60 d. The volatile compounds were various in carrot slices during storage, which were treated by different sterilization processing. Firstly, the amount of terpene compounds in each treatment group was declined during the whole storage, and terpenes' oxidation reactions possibly could be the source of this observation. The level of aldehydes was the highest in pasteurizated carrot slices, but the lowest in high hydrostatic pressure sterilizated carrot slices. Furthermore the content of hexanal, pungent and rancid flavor, was increased significantly during the whole storage. The aldehydes were mainly related to unsaturated fatty acid oxidation. Hence, this suggested that pasteurization might result in a decline in the quality of carrot slices, compared to other treatments. The β-carotene degradation products, α-ionone (violet's flower aromas) and β-ionone (Cedar's wood aromas), were detected in sterizated carrot slices 20 d after storage. The level of ionone in high hydrostatic pressure sterilizated carrots was lower than other treatments, which indicated that high hydrostatic pressure sterilization could keep a higher level of β-carotene as well. In other words, the high hydrostatic pressure sterization could keep the quality of carrot slices better. In addition, the levels of esters and alkanes had less change during the storage. The main alcohol was 4-terpineol, the oxidation product of terpinolene. The content of terpenoids decreased after sterilization treatment. And it was higher in high hydrostatic pressure and pressure-assisted thermal sterilizated carrots compared to pasteurizated carrots in 30 d, which might be due to the thermal processing inducing terpinene oxidation. However, the content of β-caryophyllene decreased obviously in high hydrostatic pressure and pressure-assisted thermal sterilizated carrot slices. Pressure could induce membrane damage and bring enzymes and substrates into contact, which would not or less occur during thermal processing. And high hydrostatic pressure sterilizated carrot slices had a higher level of myrcene and terpinolene at earlier storage compared with others, which resulted in a better light balsam smell and pine fragrance kept. Pressure-assisted thermal sterilizated carrot slices had a higher content of β-pinene and β-caryophyllene, and there was better pine resin and spicy aroma. The quality of high hydrostatic pressure sterilizated and pressure-assisted thermal sterilizated carrot slices was superior to pasteurizated carrot slices. The results can provide a reference for the applications of new sterilization technologies in ready-to-eat products. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:20
Main heading:Flavor compounds
Controlled terms:Aldehydes - Cold storage - Degradation - Energy storage - Esters - Fatty acids - Flavors - Heat treatment - Hydraulics - Hydrostatic pressure - Ketones - Monoterpenes - Odors - Oxidation - Paraffins - Pasteurization - Sterilization (cleaning) - Storage (materials) - Terpenes - Unsaturated fatty acids - Volatile organic compounds
Uncontrolled terms:Carrot slice - High hydrostatic pressure - Oxidation products - Oxidation reactions - Ready-to-eat products - Sterilization technology - Thermal sterilization - Volatile flavor compounds
Classification code:525.7 Energy Storage - 537.1 Heat Treatment Processes - 631.1.1 Liquid Dynamics - 632.1 Hydraulics - 694.4 Storage - 802.2 Chemical Reactions - 804.1 Organic Compounds - 822.2 Food Processing Operations - 822.3 Food Products
DOI:10.11975/j.issn.1002-6819.2016.09.037
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
<RECORD 36>
Accession number:20162002392066
Title:Estimating rainfed spring maize evapotranspiration using modified dual crop coefficient approach based on leaf area index
Authors:Feng, Yu (1); Cui, Ningbo (2); Gong, Daozhi (1); Wang, Hanbo (1); Hao, Weiping (1); Mei, Xurong (1)
Author affiliation:(1) State Key Engineering Laboratory of Crops Efficient Water Use and Drought Mitigation/Key Laboratory of Dryland Agriculture of Ministry of Agriculture, Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, China; (2) State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, China
Corresponding author:Gong, Daozhi(gongdaozhi@caas.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:90-98
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Evapotranspiration (ET) is vital to energy and water balance in agriculture, and accurate estimation and partition of ET is needed for crop water productivity improvement. In this study, a modified approach of FAO-56 dual coefficients of crop was developed for estimating and partitioning maize ET. Daily basal crop coefficient was dynamically calculated by introducing a canopy cover coeffficient which could be simply described as a function of leaf area index (LAI). Daily evaporation coefficient was also calculated by modified canopy cover that was computed by LAI. A field experiment was conducted from May to September during 2012 and 2013 in a rainfed farmland on the Loess Plateau of North China, and daily spring maize ET and soil evaporation were measured by eddy covariance system and micro-lysimeters to validate the modified approach of dual coefficients of crop. The results indicated that the LAI and the maximum plant height in 2012 were slightly larger than those in 2013, with the LAI ranging from 0 to 4.52 m<sup>2</sup>/m<sup>2</sup>in 2012 and from 0 to 3.97 m<sup>2</sup>/m<sup>2</sup>in 2013, the maximum plant height of 2.98 m in 2012 and 2.97 m in 2013, respectively. Due to large frequency of wetting by rainfall and small canopy cover in initial stage, daily evaporation coefficient fluctuated significantly; then daily evaporation coefficient decreased with the increase of canopy cover in development and mid stages, and increased in late stage. In contrast to daily evaporation coefficient, the change trend of daily basal crop coefficient was relatively small in initial stage; then daily basal crop coefficient increased with the increase of LAI in development and mid stages, and decreased in late stage. Simulated maize ET values in initial, development, mid, late and whole growing season were 47.0, 81.1, 172.7, 64.6 and 365.3 mm in 2012, and 25.1, 78.5, 211.5, 70.5 and 385.6 mm in 2013, respectively, which were in good agreement with the measured ET, with the coefficient of determination (R<sup>2</sup>) of 0.824, root mean square error (RMSE) of 0.561 mm/d, coefficient of model efficiency (E<inf>ns</inf>) of 0.817, and average absolute error (AAE) of 0.449 mm/d in 2012, R<sup>2</sup>of 0.870, RMSE of 0.381 mm/d, E<inf>ns</inf>of 0.871, and AAE of 0.332 mm/d in 2013, respectively. The good agreements were found between the simulated soil evaporation using the modified approach of dual coefficients of crop and the measured one by micro-lysimeters; the simulated soil evaporation was 1.71, 1.25, 0.61, 0.78 and 0.98 mm/d in initial, development, mid, late and whole growing season, which accounted for 79.86%, 59.95%, 20.20%, 28.88% and 38.12% of ET in 2012, and 0.75, 0.96, 0.87, 0.77 and 0.86 mm/d in initial, development, mid, late and whole growing season, which accounted for 66.96%, 51.34%, 54.04%, 29.62% and 33.59% of ET in 2013, respectively. The results suggested that the modified approach of dual coefficients of crop could estimate and partition rainfed maize ET accurately on the Loess Plateau of North China, and thus could be a useful method for agricultural water management. The current study doesn't take the effects of maize planting density and direction of maize sowing-line on ET into consideration, and lacks the measured transpiration data, which may bring some uncertainties, and therefore, a further study considering these factors is needed to improve the performances of the approach of dual coefficients of crop. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:36
Main heading:Evapotranspiration
Controlled terms:Agriculture - Crops - Evaporation - Landforms - Lysimeters - Mean square error - Models - Productivity - Rain - Sediments - Soil surveys - Soils - Water management
Uncontrolled terms:Agricultural water management - Coefficient of determination - Crop coefficient - Eddy covariance systems - Energy and water balance - Evaporation coefficients - Loess Plateau - Spring maize
Classification code:443.3 Precipitation - 481.1 Geology - 483 Soil Mechanics and Foundations - 483.1 Soils and Soil Mechanics - 802.3 Chemical Operations - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.4 Agricultural Products - 922.2 Mathematical Statistics - 943.3 Special Purpose Instruments
DOI:10.11975/j.issn.1002-6819.2016.09.013
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
<RECORD 37>
Accession number:20162002392073
Title:Grain yield data collection and service for heterogeneous platforms
Authors:Zheng, Lihua (1); Guo, Xiang (1); Li, Minzan (1); Li, Xincheng (1); Chen, Yuan (1); Xiao, Changyi (1)
Author affiliation:(1) Key Laboratory of Modern Precision Agriculture System Integration Research, Ministry of Education, China Agriculture University, Beijing, China
Corresponding author:Li, Minzan(limz@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:142-149
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Crop yield information is the precondition for the implementation of precision agriculture, and it is the key to organize farmland production and achieve decision-making for agricultural management. Aiming at collecting yield data by the grain yield measurement and control system in harvest field and transmitting the collected data to the yield server in real time, and meanwhile meeting the demands of data access to all kinds of terminals, a data collection and service platform for monitoring grain yield was developed. It is helpful to achieve data real-time interacting among the on-site yield monitoring system, the mobile terminals and the remote yield server. Socket and SOAP (simple object access protocol) technologies are used to implement data exchanging between the remote server and various heterogeneous platforms. A grain yield data collecting system was developed and embedded in the IPC (industrial personal computer) mounted on the combine harvester to collect yield data in real time, and its modules included device setting, data collecting, data parsing and data uploading. The yield data are composed of the information input by user (farm and plot identification, which are input once for each plot), the global position system (GPS) data (longitude, latitude, altitude and time), the data (harvester speed, harvester cutter width, impulse voltage, grain moisture and grain temperature) from the sensors mounted in the harvester and the CAN (controller area network) bus. The collected yield data are packaged every 1 second and transferred to the yield server through Socket via GPRS (general packet radio service), and then they are parsed according to the yield data exchanging protocol and stored into the yield database established in the server. Then the yield data can be calculated, processed and visualized according to various modules embedded in the yield data collection and service system which is developed using Hadoop and Web GIS (web geographic information system) technologies. And the modules include user management, news management, bulletin management, document management, farm management, plot management, yield data management, harvester tracing and Web GIS service, and the grain yield data collecting system is connected with the remote data access terminals through the data collection module and data service module which are embedded in the yield data management. Yield data service is implemented using Web Service based on SOAP for data sharing for various terminals (such as mobile, tablet PC (personal computer), PDA (personal digital assistant), and desktop) with different operating systems (such as Windows, Macintosh, Linux or Android). A grain yield querying system was established for testing the yield data service XML (extensive makeup language) interface provided by the yield data collection and service system, the information including farm, plot and yield could be accessed smoothly, and the yield data visualization could be achieved accordingly. For improving the yield data transmission efficiency, GZIP (GNUzip) is used to compress SOAP messages and reduce bandwidth consumption. In addition, the digital signatures and encryption technology are used to guarantee the security of data transmission via internet. The system experiments were carried out, and the results showed that the grain yield data collecting system worked well on-site and the yield data could be collected and uploaded every 1 minute; the data collection and service system could receive, calculate, process and visualize the real-time yield data efficiently; and the Web Service interface could push the yield data querying results quickly according to client requests. The study indicates that the yield data interaction and sharing between heterogeneous platforms can be achieved by using the yield data collection and service platform proposed in this paper. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:20
Main heading:Information management
Controlled terms:Agriculture - Altitude control - Collector efficiency - Computer operating systems - Computer terminals - Control system synthesis - Controllers - Data acquisition - Data communication systems - Data handling - Data transfer - Data visualization - Decision making - Electronic data interchange - Electronic document exchange - Emergency traffic control - Farms - Formal languages - Geographic information systems - Grain (agricultural product) - Harvesters - Information services - Microcomputers - Network security - Personal computers - Personal digital assistants - Query processing - Security of data - Soaps (detergents) - Visualization - Web services - Websites
Uncontrolled terms:Cans (controller area network) - Data collection modules - Data transmission efficiency - GPRS (general packet radio service) - Industrial personal computers - Simple object access protocols - Web geographic information system - Yield monitoring
Classification code:432.4 Highway Traffic Control - 702.3 Solar Cells - 722 Computer Systems and Equipment - 723 Computer Software, Data Handling and Applications - 731.1 Control Systems - 731.3 Specific Variables Control - 732.1 Control Equipment - 804.1 Organic Compounds - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 903.3 Information Retrieval and Use - 903.4 Information Services - 912.2 Management
DOI:10.11975/j.issn.1002-6819.2016.09.020
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
<RECORD 38>
Accession number:20162002392085
Title:Fluidization effect of walnut shell particles in fluidized bed with slotted gas distributor
Authors:Li, Zhanyong (1, 2); Wang, Shaotie (1); Wang, Juan (1); Zhang, Jianguo (1, 2)
Author affiliation:(1) College of Mechanical Engineering, Tianjin University of Science and Technology, Tianjin, China; (2) Tianjin Key Laboratory of Integrated Design and On-line Monitoring for Light Industry & Food Machinery and Equipment, Tianjin, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:225-232
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Gas distributor is a key component in fluidized beds. Various gas distributors for practical application have been successfully developed and studied in depth. Fluidization of coarse particles is still a challenge for good gas-solid contacting. In this study, a slotted gas distributor with simple structure was proposed for the fluidized bed processing coarse particles. The fluidization characteristics of the Geldart D type large particles (2-2.8 mm walnut shell) were investigated experimentally in a 285 mm × 190 mm × 700mm fluidized bed with the slotted gas distributor whose opening rate was 5.6%. The experimental results were compared with the ones obtained from the traditional perforated distributor. It was found that the bed expansion ratio increased by about 5% and the minimum fluidization velocity reduced by about 8% when using the slotted gas distributor, indicating that the slotted gas distributor had better fluidization characteristics for the large-sized particles. To explain the better fluidization performance of the slotted gas distributor, a computational fluid dynamics (CFD) model was developed based on the Eulerian-Eulerian model, the particle kinetic theory, the standard k-Ε turbulence model and the SIMPLE algorithm. The CFD model was used to simulate the behaviors of the gas particle flow in the fluidized bed of walnut shell particles with slotted gas distributor or traditional perforated distributor, and the results of experiment and simulation were agreed well. The simulations were conducted under such operation conditions: The physical two-dimensional model of the rectangular fluidized bed was 285 mm × 700 mm with slotted gas distributor or traditional perforated distributor in which the opening rate was 5.6%. Particles packed in the fluidized bed had the volume fraction of 0.6 and the height of the bed was 200 mm. The superficial gas velocity of inlet was selected as operation parameter, which ranged from 0.615 to 1.128 m/s. The simulation results were compared on the bed pressure fluctuations due to bubble formation, the coalescence and eruption, the maximum bed expansion radio, the transient particle volume fraction distribution, the gas/particle velocity vector distribution and so on between the fluidized beds of these two distributors. It was observed that small bubbles first formed close to the gas distributor, coalesced when rising up, and finally erupted near the bed surface, which resulted in periodic fluctuations of bed pressure with different amplitudes and frequencies. Compared with the traditional perforated distributor, the frequency and amplitude of the bed pressure drop fluctuation caused by the slotted gas distributor were bigger and the bed expansion ratio was higher. The change of the particle concentration in the bed was scattered in the fluidized bed with slotted gas distributor, which was beneficial to the fluidization of particles near the bed wall. Also, the dead zone and recirculation area formed near the wall area were reduced. The V-shaped structure of the slotted gas distributor generated strong upward flow jets. The strong jets could deeply reach the material particle bed and easily bring the formation of bigger bubbles. The bigger bubbles caused more intensive disturbance inside the material bed, and thereby the bed pressure drop fluctuation and the bed expansion ratio were improved. Four small circulations were observed to form within the fluidized bed with slotted gas distributor, which was beneficial to the better mixing of gas and particle. Therefore, coarse particles of walnut shell can be well fluidized with the slotted gas distributor. The study provides a reference for the design and selection of fluidized bed distributor in the process of coarse particle processing in fluidized bed. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:33
Main heading:Fluidized beds
Controlled terms:Computation theory - Computational fluid dynamics - Design - Drops - Expansion - Fighter aircraft - Fluidization - Fluidized bed process - Gas dynamics - Gases - Models - Pressure drop - Shells (structures) - Structural design - Turbulence models - Volume fraction
Uncontrolled terms:Coarse particles - Computational fluid dynamics modeling - Eulerian-Eulerian modeling - Fluidization characteristics - Gas distributor - Minimum fluidization velocity - Simulation - Velocity vector distribution
Classification code:408.1 Structural Design, General - 408.2 Structural Members and Shapes - 631.1.2 Gas Dynamics - 641.1 Thermodynamics - 652.1.2 Military Aircraft - 721.1 Computer Theory, Includes Formal Logic, Automata Theory, Switching Theory, Programming Theory - 723.5 Computer Applications - 802.3 Chemical Operations - 951 Materials Science
DOI:10.11975/j.issn.1002-6819.2016.09.032
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
<RECORD 39>
Accession number:20162002392076
Title:Wheat powdery mildew forecasting in filling stage based on remote sensing and meteorological data
Authors:Ma, Huiqin (1, 2); Huang, Wenjiang (2); Jing, Yuanshu (1)
Author affiliation:(1) Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, School of Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing, China; (2) Key Laboratory of Digital Earth Science, Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences, Beijing, China
Corresponding author:Huang, Wenjiang(huangwj@radi.ac.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:165-172
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Powdery mildew is one of the main serious diseases for winter wheat. An accurate and timely forecasting of the wheat powdery mildew occurrence at the regional scale by using multi-source data can provide important information for crop protection decision making, and achieving effective prevention of wheat powdery mildew. In this study, the Landsat8 remote sensing image was used to extract the land surface temperature (LST), the vegetation indices which included normalized difference vegetation index (NDVI), modified simple ratio index (MSR), re-normalized difference vegetation index (RDVI), triangular vegetation index (TVI), optimized soil adjusted vegetation index (OSAVI), green normalized difference vegetation index (GNDVI), and the band reflectance features. Then we obtained the parameters of wheat growth environment condition such as air temperature, number of rainy days with more than 0.1 mm rainfall, total sunshine hour, average relative humidity, temperature-rain coefficient (the ratio of total rainfall in a period of time to average temperature of the same period) and rainfall coefficient (the square root of the product of rainfall and number of rainy days) in different time steps (including month, 10 days and sensitive period) with the site daily meteorological data; and then we got the corresponding space meteorological features by using the inverse distance weighted (IDW) method in GIS (geographic information system) spatial interpolation analysis. Next, we implemented screening features with the combination of relief algorithm and Poisson's correlation coefficient, and finally got the MSR, the RDVI, the total sunshine hour from March 21<sup>st</sup>to April 20<sup>th</sup>, and the number of rainy days with more than 0.1 mm rainfall from April 11<sup>th</sup>to May 10<sup>th</sup>, which were as optimal explanatory variables for developing the powdery mildew forecasting model. The relevance vector machine (RVM) model was used to improve business decisions, detect disease, and forecast weather. And then we used it to predict the probability of powdery mildew occurrence in filling stage of wheat in Gaocheng, Jinzhou and Zhaoxian County, Shijiazhuang City, Hebei Province through remote sensing and meteorological data. The model combining remote sensing and meteorological data produced a higher Spearman relevance value than the single remote sensing data or the meteorological data model, and moreover, the values of Somers'D, Goodman-Kruskal Gamma, and Kendal's Tau-c of the remote sensing and meteorological data model were all higher than those of the other 2 models. They all indicated that the remote sensing and meteorological data model had a better performance than the other 2 models. The results showed that: the overall accuracy of the remote sensing and meteorological data model was the highest among the 3 methods, with lower omission and wrong judgement than the other 2 models. Furthermore, the overall accuracy and the kappa coefficient of the remote sensing and meteorological data model were 84.2% and 0.686 respectively, which showed better performance over the remote sensing data model (80.0% and 0.602) and the meteorological data model (74.7% and 0.500). These results reveal that compared with the single meteorological data or remote sensing data, the combination of remote sensing and meteorological data is more suitable for the prediction of crop disease occurrence situation in the regional scale. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:35
Main heading:Remote sensing
Controlled terms:Atmospheric temperature - Crops - Decision making - Diagnosis - Forecasting - Fungi - Geographic information systems - Image reconstruction - Inverse problems - Meteorology - Precipitation (meteorology) - Rain - Space optics - Vegetation - Weather forecasting
Uncontrolled terms:GIS (geographic information system) - Green normalized difference vegetation index - Inverse distance weighted - Meteorological data - Normalized difference vegetation index - Powdery mildew - Relevance Vector Machine - Spatial interpolation analysis
Classification code:443 Meteorology - 461.6 Medicine and Pharmacology - 656.1 Space Flight - 821.4 Agricultural Products - 903.3 Information Retrieval and Use - 912.2 Management
DOI:10.11975/j.issn.1002-6819.2016.09.023
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
<RECORD 40>
Accession number:20162002392057
Title:Experimental analysis on mechanical model of industrial hemp stalk
Authors:Zhou, Yang (1); Li, Xianwang (1); Shen, Cheng (1); Tian, Kunpeng (1); Zhang, Bin (1); Huang, Jicheng (1)
Author affiliation:(1) Nanjing Research Institute for Agricultural Mechanization, Ministry of Agriculture, Nanjing, China
Corresponding author:Shen, Cheng(shencheng1989@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:22-29
Language:English
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to provide the mechanical parameters for the research on industrial hemp harvest machinery, the mechanical model for industrial hemp stalk is supposed with the knowledge of mechanics of composite material in the paper. To gain the mechanical parameters, the mechanical tests like tensile test, compressive test and bending test in the light of various directions and different fractions is carried out by utilizing the WDW-10 universal testing machine. All elastic parameters of mechanical model of industrial hemp stalk were achieved through analysis and calculation with composite material theory. All of the parameters were experimentally determined for industrial hemp stalks in order to find methods for mechanical harvest with minimum energy consumption. The xylem axis elasticity modulus is 1 343.5 MPa. The phloem radial elasticity modulus is 3 607.5 MPa. The stalk axis elasticity modulus are 1 743.50 MPa. The stalk radial compressive elasticity modulus is 88 MPa. The xylem shear modulus is 33.52 MPa. The stalk shear modulus is 31.99 MPa. According to the experiment, the hemp stalk has excellent mechanical properties, especially the performance of the phloem fiber. The test result of experiment shows that radial parameters of industrial hemp stalk accord with characteristics of composite material. It is a significant guidance in hemp cutter design. This study provided a theoretical foundation for in-depth exploration on hemp cutter design and optimization to make the hemp harvester satisfy the working requirement of high quality and low consumption. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:25
Main heading:Hemp
Controlled terms:Bending tests - Composite materials - Elastic moduli - Elasticity - Energy utilization - Experiments - Industrial research - Machinery - Models - Shear strain - Tensile testing
Uncontrolled terms:Analysis and calculations - Experimental analysis - Industrial hemp - Mechanical parameters - Minimum energy consumption - Stalk - Theoretical foundations - Universal testing machines
Classification code:422 Strength of Building Materials; Test Equipment and Methods - 525.3 Energy Utilization - 821.4 Agricultural Products - 901.3 Engineering Research - 931.1 Mechanics - 951 Materials Science
DOI:10.11975/j.issn.1002-6819.2016.09.004
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
<RECORD 41>
Accession number:20162002392086
Title:Effect of ethanol dipping pretreatment on drying characteristics and quality of eggplant slices
Authors:Zhao, Haiyan (1); Fang, Xiaoming (2); Wang, Jun (1); Ju, Haoyu (1); Zhang, Yuejing (1); Chen, Xingfu (1); Zhang, Qian (3); Liu, Yanhong (1); Gao, Zhenjiang (1); Xiao, Hongwei (1)
Author affiliation:(1) College of Engineering, China Agricultural University, Beijing, China; (2) Bee Research Institute of Chinese Academy of Agricultural Sciences, Beijing, China; (3) College of Mechanical and Electric Engineering, Shihezi University, Shihezi, China
Corresponding author:Xiao, Hongwei(xhwcaugxy@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:233-240
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Because the eggplant is widely planted all over the country, but the moisture content of fresh eggplant is high and the shelf life is short, so harvested eggplants should be dried and dehydrated in time. How to achieve high-quality dried products is one of the important directions in drying research. Chemical impregnation process is a novel pretreatment technology, and ethanol is chosen as a chemical, which has many advantages, such as fast penetration, easy to evaporate, no chemical residues and harmless to human body, and has been applied to the pretreatment of fruit and vegetable. In order to improve the drying quality of eggplant slices and shorten the drying time, the eggplant slices were dipped in ethanol before hot air drying. The effects of different drying temperature (45, 55 and 65), ethanol concentration (0, 5% and 15%) in pretreatment and slice thickness (1.0, 1.5 and 2.0 cm) on drying rate, color, rehydration ratio and microscopic structure were investigated through the orthogonal experiments in this paper. Results showed that drying temperature, ethanol concentration in pretreatment and sample thickness had significant (P<0.05) effects on the drying processing. In addition, the sample thickness was most significant, followed by drying temperature and ethanol concentration in pretreatment. The drying time decreased with the increase of temperature, increased with the increase of slice thickness of the eggplant, and decreased first and then increased with the increase of alcohol concentration in pretreatment. The whole drying process was a kind of falling-rate drying. According to Fick's Second Law, the water effective diffusion coefficient was determined, which ranged from 2.74×10<sup>-9</sup>to 7.75×10<sup>-9</sup>m<sup>2</sup>/s. The sample thickness had greater impact (P<0.05) on the rehydration ratio compared with the drying temperature and ethanol concentration, and the rehydration ratio decreased as the sample thickness increased. The ethanol concentration in pretreatment had important influence (P<0.05) on color parameters of dried eggplant slices, but the effects of eggplant thickness and drying temperature on the color and lustre were not significant, which were far less than that of ethanol concentration in pretreatment on the color and lustre. And the pretreatment with ethanol also could change the microstructure and appearance quality of the dried samples. After eggplant was dipped in ethanol with low concentration, its moisture would be faster evaporated and the internal free water would be sent out in the drying process, and the drying rate was improved. And after eggplant was impregnated with high-concentration ethanol, ethanol made eggplant's internal nutrient composition change, which resulted in its structure more compact, and prevented moisture migration in the process of drying. Taking account of the drying rate and quality attributes, drying at 55, with ethanol concentration of 15% and sample thickness of 1.5 cm were recommended as the most favorable conditions for eggplant slice drying. In this drying condition, drying time, rehydration ratio and lightness was 225 min, 4.93 and 88.24, respectively. The present findings indicate that ethanol dipping pretreatment can not only enhance drying rate but also improve color attributes of dried products. The results provide a theoretical reference for the rapid drying of high-quality eggplant slices. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:44
Main heading:Drying
Controlled terms:Color - Ethanol - Impregnation - Microstructure - Moisture - Optimization - Plants (botany) - Quality control
Uncontrolled terms:Color parameter - Effective diffusion coefficients - Eggplant slice - Ethanol concentrations - Microscopic structures - Pre-Treatment - Pretreatment technology - Rehydration ratio
Classification code:741.1 Light/Optics - 804.1 Organic Compounds - 913.3 Quality Assurance and Control - 921.5 Optimization Techniques - 951 Materials Science
DOI:10.11975/j.issn.1002-6819.2016.09.033
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
<RECORD 42>
Accession number:20162002392080
Title:Lubrication properties of fatty acid methyl esters as low-sulfur diesel enhancers
Authors:Mei, Deqing (1); Luo, Yanqiang (1); Shen, Xuefeng (1); Lu, Dayong (1); Yuan, Yinnan (2)
Author affiliation:(1) School of Automobile and Traffic Engineering, Jiangsu University, Zhenjiang, China; (2) School of Energy, Soochow University, Suzhou, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:193-197
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Increasingly rigorous restriction on the sulfur content in diesel leads to a decrease in fuel lubricity. This reduced lubricity can cause damage to the fuel injection system of an engine. Biodiesel, which is derived from animal fats or vegetable oils by transesterification under alkali or acid catalysts, has been prevailed as an alternative fuel. It has been observed that the fatty acid esters in biodiesel play an active role in enhancing lubricity. Therefore, now biodiesel can serve as an additive to low-sulfur diesel fuel. To correlate the carbon chain length, unsaturation and hydroxylation of the fatty acid methyl ester to its lubricity, methyl myristic (C14:0), methyl palmitic (C16:0), methyl stearate (C18:0), methyl oleate (C18:1), methyl linoleate (C18:2), methyl linolenate (C18:3), methyl ricinoleate (C18:1 OH), castor oil methyl ester and cooking waste oil methyl ester were added to low-sulfur diesel fuel by 0.5%, 1.0%, 1.5% and 3.0%, respectively. Two types of biodiesel from castor oil and cooking waste oil, representing the mixtures of multiple fatty acid methyl esters, were also added to diesel fuel for wear test. The specified components of the two mixture solutions were determined by GC-MS. The low-sulfur diesel used in the test was manufactured by a hydrogenation process. The lubricity of various samples was studied using a high frequency reciprocating rig (HFRR) analysis method. Each wear test was repeated three times to minimize the error. As for methyl myristic (C14:0), methyl palmitic (C16:0) and methyl stearate (C18:0), we found that the fatty acid methyl ester with longer carbon chain had a better lubricity. For the C18 series, such as methyl stearate (C18:0), methyl oleate (C18:1), methyl linoleate (C18:2) and methyl linolenate (C18:3), an enhancement in lubricity was observed with the increase in the unsaturation degree of esters. Although with the same carbon chain length and unsaturation, methyl ricinoleate (C18:1 OH), as a hydroxylated ester, had better lubricity than methyl oleate (C18:1) compared with other treatments. Meanwhile, the individual fatty acid methyl ester did not show remarkable lubricating performance as biodiesel which was composed of several esters as a mixture. Biodiesel can perform better with more hydroxylated esters. From the wear test results, the lubricity of low-sulfur diesel can meet the requirement of the national standard with the addition ratio of saturated fatty acid methyl esters, unsaturated fatty acid methyl esters and biodiesel reaching 3.0%, 1.5% and 1.0%, respectively. In all, we concluded that there was a high correlation between lubricating properties with the unsaturation degree and hydroxyl groups in ester molecules. Studying the effects of molecule structure of fatty acid esters on the lubricating properties and its operation mechanism will be greatly beneficial for choosing the suitable biodiesel components as the lubricity enhancers in low-sulfur diesel. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:20
Main heading:Fatty acids
Controlled terms:Alternative fuels - Biodiesel - Chain length - Chains - Diesel fuels - Esters - Fuel injection - Fuel oils - Fuels - Hydroxylation - Lubrication - Mixtures - Molecules - Nanocapsules - Oils and fats - Palmitic acid - Saturated fatty acids - Sulfur - Unsaturated fatty acids - Vegetable oils - Wear resistance
Uncontrolled terms:Castor oil methyl esters - Fatty acid methyl ester - Fuel injection systems - High frequency reciprocating rig - Hydrogenation process - Low sulfur diesel fuel - Lubricating performance - Lubricating properties
Classification code:523 Liquid Fuels - 602.1 Mechanical Drives - 607.2 Lubrication - 761 Nanotechnology - 802.2 Chemical Reactions - 804 Chemical Products Generally - 804.1 Organic Compounds - 931.2 Physical Properties of Gases, Liquids and Solids - 931.3 Atomic and Molecular Physics - 933 Solid State Physics
DOI:10.11975/j.issn.1002-6819.2016.09.027
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
<RECORD 43>
Accession number:20162002392093
Title:Extraction technology optimization and antioxidant activity of polysaccharides from pumpkin seeds
Authors:Wang, Libo (1); Cheng, Long (1); Xu, Yaqin (1); Wang, Taiheng (1); Li, Lubin (1); Wang, Hansong (1)
Author affiliation:(1) College of Science, Northeast Agricultural University, Harbin, China
Corresponding author:Xu, Yaqin(xu-yaqin@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:9
Issue date:May 1, 2016
Publication year:2016
Pages:284-290
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Pumpkin seeds are rich in lipids, proteins, phytosterols, vitamins, minerals and other valuable components. In recent years, many researches have showed pumpkin seeds can significantly reduce serum cholesterol and triglycerides, and play a role in the prevention and mitigation of cardiovascular disease as well as in preventing prostate disease. It has been found that natural polysaccharides extracted from plant seeds possess various important biological activities, such as anti-cancer, antioxidant, immunization and hypolipidemic activities. However, there is not much published information on polysaccharides in pumpkin seeds. For the development and utilization of polysaccharides in pumpkin seeds, at present, degreased pumpkin seed powder was used as raw material, and the extraction of polysaccharides was mainly performed by hot-water extraction. The optimum extraction technology was studied and the preliminary structure of polysaccharides was analyzed by using infrared spectrum scanning (IR) and gas chromatography (GC). Taking polysaccharide yield as an index, the effects of extraction time, extraction temperature, liquid-solid ratio were studied through the single-factor experiment. And then on the basis of single-factor experiment, the optimum extraction condition was investigated with the response surface methodology (RSM) according to the Box-Behnken center combination design principle by the Design-Expert 8.0 software. The results showed that the optimum parameters were: extraction time 2.5 h, extraction temperature 60, liquid-solid ratio 40:1 mL/g, and the extraction yield of pumpkin seed polysaccharides was 2.25%. Under this condition, the actual value was 2.18%, which was closely matched with the predicted yield. The result showed that, the developed model was adequate and precise when compared with experimental data. The monosaccharide composition of polysaccharide was analyzed through comparing the retention time against the standards by GC. Composition analysis indicated that the polysaccharides were composed of rhamnose, arabinose, xylose, mannose, glucose and galactose with a mole ratio of 0.52 : 0.88 : 0.73 : 0.14 : 1.00 : 1.12. The IR spectrum showed that pumpkin seed polysaccharide exhibited the typical absorption peaks of a polysaccharide within the wave number of 4000-500 cm<sup>-1</sup>. Three strong absorption peaks of polysaccharide within the range of 1072-996 cm<sup>-1</sup>indicated the possible presence of pyranose ring in polysaccharides. There was no peak at 1730 cm<sup>-1</sup>of COOH, which showed that polysaccharides were neutral heteropolysaccharide with the absence of uronic acid. The antioxidative assays in vitro showed that polysaccharides presented certain scavenging activity toward DPPH·, HO·, and O<sup>2-</sup>·. The scavenging activity was increased with the increasing of the sample concentration within the test dosage range. At the same test concentration, the scavenging effects of polysaccharide against these 3 radicals were slightly lower than ascorbic acid. The scavenging rate of polysaccharide was respectively 21.3%±0.14%, 57.14%±0.28% and 40.50%±0.64% at the mass concentration of 1.0 mg/mL. In the future, pumpkin seed polysaccharides might be expected to play a promising role as dietary free radical scavengers for oxidative damage prevention. The experimental results provide the basis for the further preparation of pure polysaccharide product, the structure characterization and the biological activity determination. At the same time, this study provides the theoretical basis for the further development of the pumpkin seed function and the improvement of the added value of nonfat pumpkin seed cake. © 2016, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:25
Main heading:Extraction
Controlled terms:Absorption spectroscopy - Antioxidants - Ascorbic acid - Bioactivity - Diseases - Free radicals - Gas chromatography - Glucose - Optimization - Polysaccharides - Scavenging - Seed - Technology
Uncontrolled terms:Anti-oxidant activities - Development and utilizations - Monosaccharide composition - Optimum extraction conditions - Pumpkin seeds - Response surface methodology - Single-factor experiments - Structure characterization
Classification code:461.6 Medicine and Pharmacology - 612.1 Internal Combustion Engines, General - 802.3 Chemical Operations - 804.1 Organic Compounds - 821.4 Agricultural Products - 921.5 Optimization Techniques
DOI:10.11975/j.issn.1002-6819.2016.09.040
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
期刊信息
- 主管单位 中国科学技术协会
- 主办单位 中国农业工程学会
- 主编 朱明
- 总编/社长 王应宽
- 地址 北京朝阳区麦子店街41号
- 邮编 100125
- 电话 010－59197078/7077/7076
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- Bioresource Technology
- Industrial Crops and Products
- Biomass & Bioenergy
- Biosystems Engineering
- Aquacultural Engineering
- International Journal of Agricultural and Biological Engineering
- Journal of Irrigation and Drainage Engineering
- Paddy and Water Environment
- Journal of Agricultural Engineering
- Transactions of the ASABE
- Revista Brasileira de Engenharia Agricola e Ambiental
- Applied Engineering in Agriculture
- Engenharia Agricola
- AMA-Agricultural Mechanization in Asia Africa and Latin America
- 中华人民共和国农业农村部-MARA
- 中国科学技术协会CAST
- 国家新闻出版署
- 中华人民共和国科学技术部
- 国家自然科学基金委员会
- U.S. DEPARTMENT OF AGRICULTURE
- CIGR
- ASABE
- EurAgEng-European Society for Agricultural Engineers
- American Society of Agronomy
- Crop Science Society of America
- Soil Science Society of America
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