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  Subjects -> AGRICULTURE (Total: 780 journals)
    - AGRICULTURAL ECONOMICS (78 journals)
    - AGRICULTURE (527 journals)
    - CROP PRODUCTION AND SOIL (92 journals)
    - POULTRY AND LIVESTOCK (52 journals)

AGRICULTURE (527 journals)                  1 2 3 | Last

Showing 1 - 200 of 263 Journals sorted alphabetically
Aceh International Journal of Science and Technology     Open Access   (Followers: 1)
Acta agriculturae Slovenica     Open Access   (Followers: 3)
Acta Agronomica Hungarica     Full-text available via subscription   (Followers: 1)
Acta Agronomica Sinica     Full-text available via subscription   (Followers: 5)
Acta Scientiarum. Animal Sciences     Open Access   (Followers: 1)
Acta Scientiarum. Technology     Open Access  
Acta Technologica Agriculturae     Open Access   (Followers: 1)
Acta Universitatis Sapientiae, Alimentaria     Open Access  
Advances in Agriculture     Open Access   (Followers: 5)
Advances in Agriculture & Botanics     Open Access   (Followers: 10)
Advances in Agronomy     Full-text available via subscription   (Followers: 13)
Advances in Life Science and Technology     Open Access   (Followers: 11)
AFBM Journal     Open Access  
Africa Research Bulletin: Political, Social and Cultural Series     Hybrid Journal   (Followers: 9)
African Journal of Agricultural Research     Open Access   (Followers: 3)
African Journal of Food Science     Open Access   (Followers: 3)
African Journal of Food, Agriculture, Nutrition and Development     Open Access   (Followers: 14)
African Journal of Range & Forage Science     Hybrid Journal   (Followers: 5)
Agra Europe     Full-text available via subscription   (Followers: 3)
Agribusiness : an International Journal     Hybrid Journal   (Followers: 6)
Agricultura Tecnica     Open Access   (Followers: 6)
Agricultura Tropica et Subtropica     Open Access   (Followers: 1)
Agricultura, Sociedad y Desarrollo     Open Access   (Followers: 1)
Agricultural Advances     Open Access   (Followers: 3)
Agricultural and Food Science     Open Access   (Followers: 14)
Agricultural Commodities     Full-text available via subscription  
Agricultural Economics     Hybrid Journal   (Followers: 44)
Agricultural History Review     Full-text available via subscription   (Followers: 5)
Agricultural Research     Hybrid Journal   (Followers: 3)
Agricultural Science     Full-text available via subscription   (Followers: 4)
Agricultural Science     Open Access   (Followers: 1)
Agricultural Sciences     Open Access   (Followers: 7)
Agricultural Sciences in China     Full-text available via subscription   (Followers: 4)
Agricultural Systems     Hybrid Journal   (Followers: 28)
Agricultural Water Management     Hybrid Journal   (Followers: 26)
Agriculture     Open Access   (Followers: 5)
Agriculture & Food Security     Open Access   (Followers: 9)
Agriculture (Poľnohospodárstvo)     Open Access   (Followers: 1)
Agriculture and Agricultural Science Procedia     Open Access  
Agriculture and Food Sciences Research     Open Access   (Followers: 1)
Agriculture and Human Values     Hybrid Journal   (Followers: 12)
Agriculture, Ecosystems & Environment     Hybrid Journal   (Followers: 48)
Agriprobe     Open Access  
Agrivita : Journal of Agricultural Science     Open Access   (Followers: 2)
Agro-Science     Full-text available via subscription  
Agroalimentaria     Open Access  
Agrociencia     Open Access   (Followers: 1)
Agrociencia Uruguay     Open Access  
Agrokémia és Talajtan     Full-text available via subscription   (Followers: 2)
Agrokreatif Jurnal Ilmiah Pengabdian kepada Masyarakat     Open Access  
Agronomía Colombiana     Open Access  
Agronomía Costarricense     Open Access   (Followers: 1)
Agronomía Mesoamericana     Open Access  
Agronomie Africaine     Full-text available via subscription  
Agronomy     Open Access   (Followers: 8)
Agrosearch     Open Access   (Followers: 1)
Akademik Ziraat Dergisi     Open Access  
Alinteri Zirai Bilimler Dergisi : Alinteri Journal of Agricultural Sciences     Open Access  
Ambiente & Agua : An Interdisciplinary Journal of Applied Science     Open Access   (Followers: 1)
American Journal of Agricultural and Biological Sciences     Open Access   (Followers: 10)
American Journal of Botany     Full-text available via subscription   (Followers: 15)
American Journal of Economics and Sociology     Hybrid Journal   (Followers: 26)
American Journal of Potato Research     Hybrid Journal   (Followers: 2)
American Journal of Rural Development     Open Access   (Followers: 3)
Anais da Academia Brasileira de Ciências     Open Access   (Followers: 2)
Annales des Sciences Agronomiques     Full-text available via subscription  
Annals of Agricultural and Environmental Medicine     Open Access   (Followers: 1)
Annals of Agricultural Sciences     Open Access   (Followers: 2)
Annals of Silvicultural Research     Open Access   (Followers: 1)
Annual Review of Resource Economics     Full-text available via subscription   (Followers: 10)
APCBEE Procedia     Partially Free   (Followers: 1)
Applied Economics Letters     Hybrid Journal   (Followers: 24)
Applied Financial Economics Letters     Hybrid Journal   (Followers: 7)
Arboricultural Journal : The International Journal of Urban Forestry     Hybrid Journal   (Followers: 6)
Archivos de Zootecnia     Open Access   (Followers: 1)
ARO. The Scientific Journal of Koya University     Open Access  
Arquivos do Instituto Biológico     Open Access   (Followers: 1)
Arthropod-Plant Interactions     Hybrid Journal   (Followers: 2)
Asian Economic Papers     Hybrid Journal   (Followers: 4)
Asian Journal of Agricultural Research     Open Access   (Followers: 4)
Asian Journal of Medical and Biological Research     Open Access   (Followers: 1)
Asian Journal of Plant Sciences     Open Access   (Followers: 1)
Australian Cottongrower, The     Full-text available via subscription   (Followers: 1)
Australian Economic Papers     Hybrid Journal   (Followers: 8)
Australian Economic Review     Hybrid Journal   (Followers: 7)
Australian Forest Grower     Full-text available via subscription   (Followers: 2)
Australian Forestry     Full-text available via subscription   (Followers: 2)
Australian Grain     Full-text available via subscription   (Followers: 3)
Australian Holstein Journal     Full-text available via subscription  
Australian Journal of Agricultural and Resource Economics     Hybrid Journal   (Followers: 4)
Australian Journal of Agricultural Engineering     Open Access   (Followers: 2)
Australian Sugarcane     Full-text available via subscription  
Avances en Investigacion Agropecuaria     Open Access   (Followers: 1)
B.E. Journal of Theoretical Economics     Full-text available via subscription  
Bangladesh Agronomy Journal     Open Access  
Bangladesh Journal of Agricultural Research     Open Access   (Followers: 3)
Bangladesh Journal of Scientific Research     Open Access   (Followers: 1)
Bioagro     Open Access   (Followers: 1)
Biocatalysis and Agricultural Biotechnology     Hybrid Journal   (Followers: 4)
Biocontrol Science and Technology     Hybrid Journal   (Followers: 6)
Biodiversity     Hybrid Journal   (Followers: 23)
Biodiversity : Research and Conservation     Open Access   (Followers: 24)
Biological Agriculture & Horticulture : An International Journal for Sustainable Production Systems     Partially Free   (Followers: 11)
Biosystems Engineering     Hybrid Journal   (Followers: 6)
Biotemas     Open Access  
Boletín Semillas Ambientales     Open Access  
Bragantia     Open Access   (Followers: 2)
Brazilian Archives of Biology and Technology     Open Access   (Followers: 1)
British Poultry Science     Hybrid Journal   (Followers: 5)
Buletin Peternakan : Bulletin of Animal Science     Full-text available via subscription  
Buletin Veteriner Udayana     Open Access  
Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca : Food Science and Technology     Open Access  
California Agriculture     Open Access   (Followers: 1)
Cambridge Journal of Economics     Hybrid Journal   (Followers: 40)
Canadian Water Resources Journal     Hybrid Journal   (Followers: 19)
Capitalism Nature Socialism     Hybrid Journal   (Followers: 11)
Ceiba     Open Access  
Cereal Chemistry     Full-text available via subscription   (Followers: 4)
CERNE     Open Access  
CESifo Economic Studies     Hybrid Journal   (Followers: 7)
Change and Adaptation in Socio-Ecological Systems     Open Access   (Followers: 1)
Chemical and Biological Technologies for Agriculture     Open Access  
Chilean Journal of Agricultural Research     Open Access   (Followers: 1)
Ciencia & Natura     Open Access  
Ciência e Agrotecnologia     Open Access  
Ciencia e investigación agraria     Open Access  
Ciência e Técnica Vitivinícola     Open Access  
Ciencia forestal en México     Open Access  
Ciência Rural     Open Access   (Followers: 2)
Ciencia, Tecnología y Salud     Open Access  
COCOS : The Journal of the Coconut Research Institute of Sri Lanka     Open Access   (Followers: 1)
Coffee Science     Open Access  
Cogent Food & Agriculture     Open Access  
Competition & Change     Hybrid Journal   (Followers: 8)
Computers and Electronics in Agriculture     Hybrid Journal   (Followers: 2)
Contributions to Tobacco Research     Open Access   (Followers: 1)
Corps et culture     Open Access   (Followers: 5)
Cuadernos de Desarrollo Rural     Open Access   (Followers: 1)
Cultivos Tropicales     Open Access  
Cultural Geographies     Hybrid Journal   (Followers: 16)
Cultural Sociology     Hybrid Journal   (Followers: 27)
Cultural Studies - Critical Methodologies     Hybrid Journal   (Followers: 15)
Cultural Studies of Science Education     Hybrid Journal   (Followers: 5)
Cultural Trends     Hybrid Journal   (Followers: 13)
Culture & Agriculture     Hybrid Journal   (Followers: 10)
Culture, Agriculture, Food and Environment     Hybrid Journal   (Followers: 6)
Current Life Sciences     Open Access   (Followers: 3)
Current Research in Dairy Sciences     Open Access   (Followers: 5)
Derim     Open Access  
Developments in Agricultural Economics     Full-text available via subscription   (Followers: 4)
Developments in Agricultural Engineering     Full-text available via subscription  
Diatom Research     Hybrid Journal  
Die Bodenkultur : Journal of Land Management, Food and Environment     Open Access  
Dossiers Agraris     Open Access  
Ecological Applications     Full-text available via subscription   (Followers: 112)
Economic Affairs     Hybrid Journal   (Followers: 6)
Economic and Industrial Democracy     Hybrid Journal   (Followers: 6)
Economic Bulletin     Hybrid Journal   (Followers: 4)
Economic Policy     Hybrid Journal   (Followers: 25)
Economic Record     Hybrid Journal   (Followers: 4)
Empirical Economics     Hybrid Journal   (Followers: 8)
Encuentro     Open Access  
Engineering in Agriculture, Environment and Food     Hybrid Journal  
Ensaios e Ciência: Ciências Biológicas, Agrárias e da Saúde     Open Access  
Environment and Development Economics     Hybrid Journal   (Followers: 26)
Eppo Bulletin     Hybrid Journal   (Followers: 2)
Ethology     Hybrid Journal   (Followers: 7)
EU agrarian Law     Open Access   (Followers: 3)
Euphytica     Hybrid Journal   (Followers: 7)
Eurochoices     Hybrid Journal   (Followers: 1)
European Agrophysical Journal     Open Access  
European Journal of Agronomy     Hybrid Journal   (Followers: 9)
European Journal of American Culture     Hybrid Journal   (Followers: 2)
European Journal of Health Economics     Hybrid Journal   (Followers: 17)
European Journal of Law and Economics     Hybrid Journal   (Followers: 55)
European Review of Agricultural Economics     Hybrid Journal   (Followers: 11)
EvoDevo     Open Access   (Followers: 2)
Extensão Rural     Open Access   (Followers: 1)
Farmer’s Weekly     Full-text available via subscription  
Farmlink Africa     Full-text available via subscription  
Fitosanidad     Open Access  
Folia Horticulturae     Open Access   (Followers: 1)
Food and Agricultural Immunology     Hybrid Journal   (Followers: 2)
Food and Energy Security     Open Access   (Followers: 4)
Food Biotechnology     Hybrid Journal   (Followers: 11)
Food Economics - Acta Agriculturae Scandinavica, Section C     Hybrid Journal   (Followers: 2)
Food New Zealand     Full-text available via subscription   (Followers: 3)
Food Policy     Hybrid Journal   (Followers: 28)
Forestry Chronicle     Full-text available via subscription   (Followers: 10)
Forum for Health Economics & Policy     Hybrid Journal   (Followers: 7)
Frontiers in Science     Open Access   (Followers: 1)
Frontiers of Agriculture in China     Hybrid Journal   (Followers: 2)
Future of Food : Journal on Food, Agriculture and Society     Open Access   (Followers: 1)
Geoderma     Hybrid Journal   (Followers: 8)
Ghana Journal of Agricultural Science     Full-text available via subscription   (Followers: 2)
Global Approaches to Extension Practice : A Journal of Agricultural Extension     Full-text available via subscription   (Followers: 1)
Global Economic Review     Hybrid Journal   (Followers: 6)
Global Journal of Agricultural Sciences     Full-text available via subscription  
Hacquetia     Open Access  
Handbook of Agricultural Economics     Full-text available via subscription   (Followers: 4)

        1 2 3 | Last

Journal Cover Biosystems Engineering
  [SJR: 0.773]   [H-I: 66]   [6 followers]  Follow
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1537-5110 - ISSN (Online) 1537-5129
   Published by Elsevier Homepage  [2969 journals]
  • Human powered press for producing straw bales for use in construction
           during post-emergency conditions
    • Abstract: Publication date: October 2016
      Source:Biosystems Engineering, Volume 150
      Author(s): Walter Franco, Federico Iarussi, Giuseppe Quaglia
      The straw bale construction technique is considered one of the most appropriate for the improvement of housing conditions in developing countries and for the reconstruction in post-emergency situations. In this environment, no electricity or other energy sources are available; for this reason, straw bales have to be produced by means of a human powered press. This paper presents the designing process of a manual press, that is a key tool for the objectives introduced above. Following definition of the machine architecture and the actuating mechanism (slider-crank), a design method based on energy considerations is introduced. Given the mechanical properties of straw, described by a simplified linear model, and the maximum work that a human operator can do, applying the designing method, it was possible to obtain the main functional parameters of the machine, such as the pressing piston stroke, and the length both of the connecting rod and of the crank. The method was experimentally validated and a prototype assembled and used for the production of infill bales in the construction of a warehouse in Haiti.

      PubDate: 2016-08-24T13:30:11Z
  • Simultaneous localisation and mapping in a complex field environment
    • Abstract: Publication date: October 2016
      Source:Biosystems Engineering, Volume 150
      Author(s): Peter Lepej, Jurij Rakun
      The usefulness of image registration techniques in mapping and localising a robot in an agricultural environment by using readings from a laser range scanner was investigated. The proposed approach used frequency domain and correlation. Translational and rotational differences that occur between successive readings of the scanner and that correspond to the movement of the robot were used. The approach was tested on 9 test runs, with a total of 252 m in length, recorded in an apple orchard and in a vineyard. The results were then compared to results from the Hector mapping algorithm. It was shown that the present approach performed very well compared to Hector mapping. On average achieved an 4.24% ± 2.9% error rate and the present approach 0.16% ± 0.1%. Hector mapping on the other hand proved better in cases where rotational differences were looked for, reaching an error rate of 1.69% ± 0.7% in comparison to present approach with an error rate of 4.19% ± 3.1%.

      PubDate: 2016-08-24T13:30:11Z
  • Editorial Board
    • Abstract: Publication date: September 2016
      Source:Biosystems Engineering, Volume 149

      PubDate: 2016-08-24T13:30:11Z
  • A numerical study on forced convective heat transfer of a chicken (model)
           in horizontal airflow
    • Abstract: Publication date: October 2016
      Source:Biosystems Engineering, Volume 150
      Author(s): Hao Li, Li Rong, Chao Zong, Guoqiang Zhang
      Under hot climatic conditions, heat stress of the animal is a general concern in livestock farming. To reduce the heat stress, an important approach is ensuring a suitable air speed in the animal occupied zone (AOZ) to increase convective heat removal for animals. Therefore, the relationship between convective heat transfer and air speed is essential to understand the effects of the airflow speed manipulation, and consequently, the optimal design and control of a ventilation system. In this study, computational fluid dynamics (CFD) was employed to study the convective heat transfer coefficient for a chicken. Simulated results were compared with the experimental data found in the literature. SST k–ω model was evaluated on a sphere model first by comparing it to a semi-experimental equation of the convective heat transfer coefficient. Good agreement was found and therefore this numerical method was adopted for further modelling with a more realistic geometric model of a chicken. Three different angles between the chicken trunk axis and airflow direction: 0°, 45°, and 90° were studied as well as various chicken weights of the model. The study results revealed that the angle at which the airflow struck the chicken model was not significant. By testing chicken models at different weights (bird mass of 0.2 kg, 0.9 kg, and 2 kg), larger specific surface (the ratio of surface area to the weight) led to a higher convective heat transfer coefficient. In addition, a correlation of the predicted convective heat transfer coefficients was found between a sphere and the chicken models used, indicating that a chicken can be simplified as spherical model in future studies.

      PubDate: 2016-08-24T13:30:11Z
  • Comparing different methods of using collecting trays to determine the
           spatial distribution of fertiliser particles
    • Abstract: Publication date: October 2016
      Source:Biosystems Engineering, Volume 150
      Author(s): Simon R. Cool, Jürgen Vangeyte, Koen C. Mertens, David R.E. Nuyttens, Bart R. Sonck, Tim C. Van De Gucht, Jan G. Pieters
      Precise application of granular fertiliser requires the correct calibration of spreading equipment. Currently, the performance of spreaders is assessed by determining the transverse distribution using a row of collection trays aligned perpendicularly to the driving direction. When the homogeneity of the distribution for a given spreader with a given fertilizer is inadequate, the spreader settings need to be corrected. However, because particle deposition is measured in only one dimension, this technique does not provide an adequate insight into the spreading process as a whole. The distribution should be measured in two dimensions, which, due to the large spreading widths involved with modern spreaders, is only possible by sampling the spreading area. In this paper, two different two-dimensional methods to determine spreading pattern were evaluated, each consisting of a sampling method and a matching interpolation algorithm. Both sampling methods use a similar number of collecting trays. Experiments were executed using three commonly used types of fertiliser (CAN (Ammonium-nitrate fertiliser), NPK (Compound fertiliser), KCl (Potassium-chloride fertiliser)) with different physical properties. The resulting spreading patterns were compared with the standard one-dimensional technique. Differences were found both in the application rate and application homogeneity. The results illustrated the importance of using an adequate spreading pattern measurement technique to accurately compare the spreading patterns of granular fertiliser spreaders.

      PubDate: 2016-08-19T13:20:48Z
  • Test results and empirical correlations to account for air permeability of
           agricultural nets
    • Abstract: Publication date: October 2016
      Source:Biosystems Engineering, Volume 150
      Author(s): Sergio Castellano, Giuseppe Starace, Lorenzo De Pascalis, Marco Lippolis, Giacomo Scarascia Mugnozza
      Fifteen HDPE agricultural nets were tested inside a micro wind tunnel (0.1345 m diameter) to establish their characteristic air flow rate vs pressure drop curves with velocities >4 m s−1. The air pressure drop through the net was accounted for, with reference to the Bernoulli scheme, by means of the loss coefficient. Experimental results confirmed those available in the literature, in terms of the dependence of the pressure drop on the velocity squared and the net porosity, ε, by means of the function h ( ε ) = ( 1 − ε 2 / ε 2 ) . The influence of the orifice geometry was investigated and an effect equivalent to the increase in net porosity was identified in textile pores with elongated shapes. As with previous studies, the loss coefficient trend was found to fit the product of two functions, one depending on the porosity, and the other on the Reynolds number defined using the pore equivalent diameter. The calculated values of the loss coefficient show deviations from experimental results in the range of 19.9–41.1%. In addition, a new formulation for the loss coefficient, dependent only on the porosity and wet perimeter was proposed. Except for higher porosity nets the simplified formulation, showed the best match with the experimental data. The two formulations of the loss coefficient proposed here were compared with those found in the literature.

      PubDate: 2016-08-11T13:02:13Z
  • Modeling intrinsic kinetics in a reactor of corona discharge coupled with
    • Abstract: Publication date: October 2016
      Source:Biosystems Engineering, Volume 150
      Author(s): Sheng-ying Ye, Jia-liang Liang, Xian-liang Song, Shu-can Luo, Jia-yong Liang
      A reactor that is able to degrade ethylene efficiently inside a cold humid storehouse was designed for the purpose of extending the shelf-life of horticultural products. The reactor generates non-thermal plasma by corona discharge, improves the ethylene degradation efficiency, and controls the ozone concentration with titanium dioxide-activated carbon fibre (TiO2/ACF). To arrive at a rational reactor design, we investigated the intrinsic kinetics of the reaction process. According to the order of reaction, reactions in which ethylene or ozone are involved in the discharge process could be classified into four categories: non-thermal plasma formation, ethylene degradation, ethylene ozonolysis, and ozone decomposition. Therefore, we present an intrinsic kinetics model, which is in the form of an autonomous first-order ordinary differential equation set, combining two dependent variables, i.e., the concentrations of ethylene and ozone. Experimental data obtained for the corona discharge, the corona discharge coupled with an ACF film, and a corona discharge coupled with a TiO2/ACF film proved that the model is capable of describing the concentrations of ethylene and ozone. The rate constants reveal that the intrinsic kinetics as internal mass transport are accounted for. The corona discharge coupled with the TiO2/ACF film increased the rate constant of ethylene degradation (k 2) and decreased the rate constant of ozone formation (k 1). However, it did not obviously influence the rate constant of ethylene ozonolysis (k 3) and the rate constant of ozone decomposition (k 4).

      PubDate: 2016-08-11T13:02:13Z
  • Evaluation of oil spraying systems and air ionisation systems for
           abatement of particulate matter emission in commercial poultry houses
    • Abstract: Publication date: October 2016
      Source:Biosystems Engineering, Volume 150
      Author(s): Albert Winkel, Julio Mosquera, André J.A. Aarnink, Peter W.G. Groot Koerkamp, Nico W.M. Ogink
      The present study evaluated the performance of four systems for abatement of particulate matter (PM) emission inside full-scaled commercial poultry houses: a fixed oil spraying system (OSF) inside two broiler farms and one laying hen house, an autonomously driving oil spraying vehicle (OSV) in one laying hen house, a negative air ionisation system (NAI) inside two broiler farms, and a positive air ionisation system (PAI) inside two laying hen houses. The systems were evaluated using case-control approaches. At each farm, six 24-h measurements were scheduled of PM10, PM2.5, ammonia, odour, and carbon dioxide concentrations (the latter for estimation of the ventilation rate and herewith emissions). This paper presents the layout of the systems, compares their performance in practice with that under experimental conditions, discusses improvement possibilities, reports the baseline emission rates of the poultry houses, and discusses the validity of the case-control approaches. The emission reductions of PM10 and PM2.5 were: 60% and 53% for the OSF in broilers (at 12 mL m−2 d−1), 21% and 31% for the OSF in laying hens (at 15 mL m−2 d−1), 32% and 38% for the OSV in laying hens (at 30 mL m−2 d−1), 49% and 68% for the NAI in broilers, and 6% and zero for the PAI in laying hens. None of the systems significantly reduced the emission rate of odour or ammonia. On the basis of this work, emission reduction factors of the OSF, OSV, and NAI have been adopted in Dutch regulations.

      PubDate: 2016-08-07T12:59:44Z
  • Multi-crop-row detection algorithm based on binocular vision
    • Abstract: Publication date: October 2016
      Source:Biosystems Engineering, Volume 150
      Author(s): Zhiqiang Zhai, Zhongxiang Zhu, Yuefeng Du, Zhenghe Song, Enrong Mao
      Pathway determination is an important process in vision-based navigation. The pathway is very difficult to determine simply using 2D image processing, because fields are often infested with weeds, and images contain shadows, illumination variation, irregular backgrounds and other unexpected noise. Stereo vision techniques can be used to locate the spatial positions of crop rows for pathway determination. However, the stereo matching of field images is generally time-consuming and insufficiently accurate. To solve this problem, a multi-crop-row detection algorithm based on binocular vision is proposed in this paper. The algorithm is composed of the modules of image preprocessing, stereo matching and centreline detection of multiple crop rows. An accurate stereo matching method was put forward to locate the 3D position of crop rows based on the rank transformation, Harris detector and random sample consensus methods. A new method for detecting the centrelines of multiple crop rows was proposed according to their spatial distribution. The proposed algorithm was validated by comparative experiments. Regarding the proposed algorithm in situations without turnrows, the correct detection rate is greater than 92.78%; for the average deviation angle, the absolute average value is less than 1.05°, and the average standard deviation is less than 3.66°; for the processing time, the average value is less than 634 ms, and the average standard deviation is less than 101 ms. The results indicate that the proposed algorithm can satisfy the requirements of accuracy and real-time execution in field operation.
      Graphical abstract image

      PubDate: 2016-08-07T12:59:44Z
  • An interactive photogrammetric method for assessing deer antler quality
           using a parametric Computer-Aided Design system (Interactive
           Photogrammetric Measure Method)
    • Abstract: Publication date: October 2016
      Source:Biosystems Engineering, Volume 150
      Author(s): Miguel A. Rubio-Paramio, Juan M. Montalvo-Gil, José A. Ramírez-Garrido, Débora Martínez-Salmerón, Concepción Azorit
      In the area of deer antler evaluation for trophy homologation, as well as in the obtaining of biometric databases for later analysis in the field of Geometric Morphometrics, different linear biometric tools have traditionally been used. In this study we used two sets of antlers from 29 Iberian red deer (Cervus elaphus hispanicus) to develop and establish a new photogrammetric technique which creates the 3D model of the antler using a parametric 3D Computer-Aided Design (CAD). This simple and reliable method for deer hunting trophy homologation was compared with the other two more extensively used methods of antler measurement, the traditional measuring tape and the Articulated Arm Coordinate Measuring Machine (AACMM or CMA). The advantage of this innovative photogrammetric method is the use of only two photographs to obtain both the 3D model and the dimensions required for antler evaluation. A procedure was performed to compare lengths and antler evaluation as hunting trophy. The three methods showed similar reliability, although the photogrammetric process using the 3D CAD system was much faster and more functional than both the traditional measuring tape and Articulated Arm methods. Since this method only requires two photographs per individual, it makes possible the study of a high percentage of antlers in the field. This new photogrammetric method has been successfully used in the biometrics area, but it could become a more extensively used method in this and other fields because of its ease of operation, speed and accuracy of data collection.

      PubDate: 2016-08-07T12:59:44Z
  • A shadow-based method to calculate the percentage of filled rice grains
    • Abstract: Publication date: October 2016
      Source:Biosystems Engineering, Volume 150
      Author(s): Tao Liu, Wei Wu, Wen Chen, Chengming Sun, Chen Chen, Rui Wang, Xinkai Zhu, Wenshan Guo
      Rice grain filling is a critical factor that determines the grain yield. It is important to measure the percentage of filled grains (PFR) in rice production management and scientific research. Current methods to measure filled grain percentage are generally manual, which are all time-consuming and labour-intensive with subjective results. Here, we designed an image analysis-based method to measure the percentage of filled grains using four light sources to generate grains shadows from four different directions. The differences of grain shadows between filled and unfilled grains were found out. The ratio of shadow characteristics to grain characteristics distinguished filled and unfilled grains. The conveyor belt with a vibrating feeder and controlled variable-speed was used to measure batched grains. The maximum measuring speed of the conveyor belt was about 60–100 grains/s, and the proper measuring speed was about 40–50 grains/s. Support vector machine (SVM) identified the unfilled grains, and the percentage of the unfilled grains was calculated for 8 Indica and 8 Japonica rice cultivars. The average false positive rate for Indica rice was 3.85%, and the average false negative rate was 5.44%. The average false positive rate for Japonica rice was 5.11%, and the average false negative rate was 3.54%. All these results indicate that this method is reliable and can be used for fast and intelligent measurement of filled grain percentage. The method shows great potential in improving the efficiency of grains' trait evaluation in crop breeding and cultivation research.

      PubDate: 2016-08-07T12:59:44Z
  • Ammonia concentrations and emission rates at a commercial poultry manure
           composting facility
    • Abstract: Publication date: October 2016
      Source:Biosystems Engineering, Volume 150
      Author(s): Lingying Zhao, Lara Jane S. Hadlocon, Roderick B. Manuzon, Matthew J. Darr, Harold M. Keener, Albert J. Heber, Jiqin Ni
      Composting facilities are essential parts of most manure-belt (MB) poultry houses in the U.S., but their NH3 concentrations and emission are not well understood. This may affect farm operation safety and limit the development of NH3 mitigation and management strategies. The study aimed to quantify NH3 concentrations and hen-specific emission rates (ER) at a commercial poultry manure composting facility and to understand their diurnal and seasonal variations. Two large tunnel-ventilated composting buildings with twelve 122-cm exhaust fans were chosen as the study site, which received manure from four on-site manure-belt layer barns. The inlet and exhaust NH3 concentrations at the compost building were monitored quasi-continuously for one month per season for two years. Ammonia ERs were calculated based on the NH3 concentrations and building ventilation rates. The average daily mean ± SD of the NH3 concentrations in spring, summer, fall, and winter were 114 ± 20, 144 ± 35, 115 ± 13, and 141 ± 25 ppmv, respectively. Seasonal and diurnal variations existed in both NH3 concentrations and ERs. The daytime NH3 ER was significantly higher than that of night time. These results showed that NH3 emissions from composting facilities are considerably high, and thus mitigation strategies are needed to further reduce NH3 from the whole MB layer facility system.

      PubDate: 2016-08-07T12:59:44Z
  • Effects of the underdrain design on the pressure drop in sand filters
    • Abstract: Publication date: October 2016
      Source:Biosystems Engineering, Volume 150
      Author(s): Toni Pujol, Gerard Arbat, Josep Bové, Jaume Puig-Bargués, Miquel Duran-Ros, Joaquim Velayos, Francisco Ramírez de Cartagena
      The effect of the nozzle geometry on the pressure drop of a sand filter was experimentally studied. Four nozzles were analysed: one commercially produced with a conical shape and three alternative cylindrical underdrains that differed in the location and the number of slots. Experiments in both filtration mode and backwashing conditions for a wide range of superficial velocities were carried out. The results reported a reduction of the filter energy consumption greater than 20% could be achieved by simply modifying the position of the slots above the surface of the underdrain element. The effects of the nozzle were further investigated by means of an analytical model that correctly predicted the pressure drop of the water flow through the filter. The model confirmed that the distribution of the slots in the underdrain was a critical factor for determining the length of the region with a non-uniform flow within the sand. When using the commercial nozzle at flow rates >0.85 l s−1, this region produced the major contribution to energy losses in the filter due to increases in the tortuosity of the water path within the porous medium. From these results, it is suggested that an affordable way to increase the energy efficiency of already existing installations would be to replace the current underdrain elements with new improved designs.

      PubDate: 2016-08-03T12:53:29Z
  • Development of a grow-cell test facility for research into sustainable
           controlled-environment agriculture
    • Abstract: Publication date: October 2016
      Source:Biosystems Engineering, Volume 150
      Author(s): Ioannis Tsitsimpelis, Ian Wolfenden, C. James Taylor
      The grow-cell belongs to a relatively new category of plant factory in the horticultural industry, for which the motivation is the maximization of production and the minimization of energy consumption. This article takes a systems design approach to identify the engineering requirements of a new grow-cell facility, with the prototype based on a 12 m × 2.4 m × 2.5 m shipping container. Research contributions are made in respect to: (i) the design of a novel conveyor-irrigation system for mechanical movement of plants; (ii) tuning of the artificial light source for plant growth; and (iii) investigations into the environmental conditions inside the grow-cell, including the temperature and humidity. In particular, the conveyor-irrigation and lighting systems are optimised in this article to make the proposed grow-cell more effective and sustainable. With regard to micro-climate, data are collected from a distributed sensor array to provide improved understanding of the heterogeneous conditions arising within the grow-cell, with a view to future optimisation. Preliminary growth trials demonstrate that Begonia semperflorens can be harvested to the satisfaction of a commercial grower. In future research, the prototype unit thus developed can be used to investigate production rates, plant quality and whole system operating costs.

      PubDate: 2016-08-03T12:53:29Z
  • Parameter sensitivity for tractor lateral stability against Phase I
           overturn on random road surfaces
    • Abstract: Publication date: October 2016
      Source:Biosystems Engineering, Volume 150
      Author(s): Zhen Li, Muneshi Mitsuoka, Eiji Inoue, Takashi Okayasu, Yasumaru Hirai, Zhongxiang Zhu
      Statistics show that lateral overturns are the most frequent fatal accidents involving tractors. There is thus much research interest in improving tractor lateral stability. Previous research has discovered the effects of various factors on tractor dynamic responses. While these factors have been analysed separately, their relative significance with respect to other factors remain uncertain. Furthermore, the practical limits of what operators can do have not been considered. The present study assumed a possible case that a tractor operator has several spare tyres of different types and service condition. Additionally, the ballast weight, track width, and implement position can usually be controlled before operation. A scale model tractor was thus developed allowing changes to these factors. The model tractor was designated to pass over typical farming road surfaces. Moreover, the tractor lateral stability was evaluated in terms of the roll angle, lateral-load transfer ratio, and Phase I overturn index. Employing the Taguchi method, we arranged experiments and assessed the applicability of the three kinds of indexes regarding tractor Phase I overturn. Results revealed that the roll angle did not well reflect the initiations of overturns. Compared with the lateral-load transfer ratio, the Phase I overturn index had more convincing factorial effects on tractor stability. Further investigation of the suggested tractor configuration supported this conclusion by comparing predicted and experimental results. In practical cases, this approach may provide a reference for engineers to help operators improve driving safety with limited spare parts.

      PubDate: 2016-08-03T12:53:29Z
  • Transpiration and moisture evolution in packaged fresh horticultural
           produce and the role of integrated mathematical models: A review
    • Abstract: Publication date: October 2016
      Source:Biosystems Engineering, Volume 150
      Author(s): Graziele G. Bovi, Oluwafemi J. Caleb, Manfred Linke, Cornelia Rauh, Pramod V. Mahajan
      Transpiration has various adverse effects on postharvest quality and the shelf-life of fresh fruit and vegetables (FFV). If not controlled, the water released through this process results in direct mass loss and moisture condensation inside packaged FFV. Condensation represents a threat to the product quality as water may accumulate on the product surface and/or packaging system, causing defects in external appearance and promoting growth of spoilage microorganisms. Thus, moisture regulation is extremely important for extending FFV shelf-life. This review focuses on transpiration phenomenon and moisture evolution in packaged fresh horticultural produce. It provides recent information on various moisture control strategies suitable for packaging of fresh horticultural produce. It also provides an evaluation on the role and application of integrative mathematical modelling in describing water relations of FFV for packaging design, as well as, an overview of models reported in literature.

      PubDate: 2016-08-03T12:53:29Z
  • Stomatal resistance of New Guinea Impatiens pot plants. Part 1: Model
           development for well watered plants based on design of experiments
    • Abstract: Publication date: September 2016
      Source:Biosystems Engineering, Volume 149
      Author(s): Hacene Bouhoun Ali, Pierre-Emmanuel Bournet, Patrice Cannavo, Etienne Chantoiseau, Mathilde Sourgnes
      In greenhouses, reducing water consumption by increasing water efficiency in order to fulfil the requirements of sustainability is a challenge. To reach this goal, we need to better understand the water demand of plants. Transpiration is the main mechanism involved in water transfer, which is controlled by stomatal resistance Rs. Predictive models can be used to assess this parameter. However, few models currently exist for greenhouse plants grown in pots. The aim of this work is to develop a model of Rs based on full factorial design (FFD), and to validate it for greenhouse plants at various growth stages. FFD is based on an optimisation process to establish a polynomial relationship between Rs and radiation, humidity, and temperature. To establish the parameters of the model, a set of experiments was conducted inside a 10-m2 growth chamber with New Guinea Impatiens grown in pots. Rs was measured with a porometer under nine climatic scenarios. Once the parameters were determined, the FFD model was validated against experimental data recorded from a greenhouse Impatiens crop, and compared with the Jarvis model. The slopes of the linear regression between measured Rs values and Rs values predicted from the FFD and Jarvis models varied within the range 0.89–1.12 for FFD and 0.45–0.54 for Jarvis. FFD was therefore able to correctly simulate Rs. Its main advantage was to only require few data for its calibration, contrary to the Jarvis model. In a next step, it will be used to predict transpiration rates.

      PubDate: 2016-08-03T12:53:29Z
  • Use of geophysical data for assessing 3D soil variation in a durum wheat
           field and their association with crop yield
    • Abstract: Publication date: Available online 25 July 2016
      Source:Biosystems Engineering
      Author(s): Giovanni Cavallo, Daniela De Benedetto, Annamaria Castrignanò, Ruggiero Quarto, Alessandro Vittorio Vonella, Gabriele Buttafuoco
      From the perspective of Precision Agriculture, the delineation of management zones in agricultural fields to optimise the use of soil and water resources and increase farmer's profitability requires knowledge of fine-scale variability. The objective of this paper is to delineate management zones in terms of yield performance verifying the suitability of Ground Penetrating Radar (GPR) to assess spatial variation of soil properties. In a durum wheat field in southern Italy, yield data were recorded and a GPR survey carried out after harvesting. On the basis of spatial distribution of the yield, the field was split into four management zones (MZs) and the expected values and standard deviations of GPR signal amplitude data were estimated using polygon kriging for each MZ. In order to interpret the results and assess the resistivity of the soil, the total sand content and bulk electrical conductivity from an electromagnetic induction (EMI) sensor were estimated by polygon kriging. The acquisition of very fine-scale soil information with GPR allowed 3D variability in the field to be imaged. Further, the study has shown the existence of a physically-based relationship between the yield of the wheat and the structural properties of the soil detected by GPR.

      PubDate: 2016-07-28T21:23:21Z
  • Assessment of laboratory VIS-NIR-SWIR setups with different spectroscopy
           accessories for characterisation of soils from wildfire burns
    • Abstract: Publication date: Available online 18 July 2016
      Source:Biosystems Engineering
      Author(s): Olga A. Rosero-Vlasova ​, Fernando Pérez-Cabello, Raquel Montorio Llovería, Lidia Vlassova
      Thousands of hectares of Mediterranean forests are burned every year. Fires affect all the landscape components. They trigger erosion processes, which can have catastrophic consequences. Thus, detection and post-fire monitoring of soil properties is of great importance. Changes in soil caused by the fire can be detected by proximal soil sensing. In this context, the study evaluates the applicability of laboratory experimental setups for spectral analysis of burnt soils. Three setups of Analytical Spectral Device (ASD) FieldSpec®4 spectroradiometer with different spectroscopy accessories (external integrating sphere, illuminator lamp and contact probe) were used for measurement of reflectance spectra and evaluation of soil organic matter (SOM) in 82 soil samples from wildfire burns in Aragon, Northern Spain. No statistically significant differences were detected between values obtained by different setups. Lower reflectances registered with integrating sphere are probably due to the fact that the internal cavity of the device is not perfectly spherical because of the existence of multiple port windows. Measurements with Illuminator lamp and contact probe were more stable and corresponding calibration models for SOM built using partial least square regression combined with step-down variable selection algorithm (SA-PLSR) demonstrated acceptable predictive ability (0.75 ≤ R2 V ≤ 0.81; 2.00 ≤ RPD ≤ 2.55). The coefficients are ∼10% higher than those obtained with the integrating sphere. The study demonstrated feasibility of using Visible – Near InfraRed – Short Wave InfraRed (VIS-NIR-SWIR) spectroscopy for monitoring post-fire evolution of burnt soils and showed that the choice of the appropriate accessory (e.g., Illuminator lamp) improves the reliability of SOM estimations.

      PubDate: 2016-07-23T21:03:59Z
  • Stomatal resistance of New Guinea Impatiens pot plants. Part 2: Model
           extension for water restriction and application to irrigation scheduling
    • Abstract: Publication date: September 2016
      Source:Biosystems Engineering, Volume 149
      Author(s): Patrice Cannavo, Hacène Bouhoun Ali, Etienne Chantoiseau, Christophe Migeon, Sylvain Charpentier, Pierre-Emmanuel Bournet
      In greenhouses, reducing water consumption by increasing water efficiency is of high interest. To reach this goal, predictive models of soil-plant-atmosphere water transfer could be helpful. However, such models have been mainly developed for open field conditions, and very few models exist for greenhouse plants grown in pots. Moreover, most of these models were implemented under well-watered conditions, but very few are available under water restriction. The aim of this study is to develop an integrated soil-plant-atmosphere water balance model applied to potted plants grown in greenhouses, to predict plant transpiration under different restrictive irrigation regimes. Implementing such a model requires an accurate estimation of stomatal resistance R s under water restriction conditions. R s is then used in the Penman-Monteith model to evaluate transpiration. To establish the model parameters, an experiment was conducted for sixteen weeks inside a greenhouse with ornamental plants (New Guinea Impatiens) grown in containers on shelves. Well-watered and water restriction conditions were applied. The peat matric potential, radiation, temperature and humidity were continuously recorded, while R s was measured and transpiration was assessed every half-hour from 8:00 am to 8:00 pm 10, 11, 12, 14, and 16 weeks after planting. The resulting model was first validated against experimental measurements during the twelfth week of the experiment. It displayed good correlations for both the instantaneous data and integrated total transpiration. Different scenarios of irrigation reduction (frequency x volume) were tested and the results indicated real potential for water use reduction. Indeed, by reducing water application by 50% and by applying one irrigation per day, transpiration was not affected.

      PubDate: 2016-07-17T15:06:15Z
  • Agricultural robots for field operations: Concepts and components
    • Abstract: Publication date: September 2016
      Source:Biosystems Engineering, Volume 149
      Author(s): Avital Bechar, Clément Vigneault
      This review investigates the research effort, developments and innovation in agricultural robots for field operations, and the associated concepts, principles, limitations and gaps. Robots are highly complex, consisting of different sub-systems that need to be integrated and correctly synchronised to perform tasks perfectly as a whole and successfully transfer the required information. Extensive research has been conducted on the application of robots and automation to a variety of field operations, and technical feasibility has been widely demonstrated. Agricultural robots for field operations must be able to operate in unstructured agricultural environments with the same quality of work achieved by current methods and means. To assimilate robotic systems, technologies must be developed to overcome continuously changing conditions and variability in produce and environments. Intelligent systems are needed for successful task performance in such environments. The robotic system must be cost-effective, while being inherently safe and reliable—human safety, and preservation of the environment, the crop and the machinery are mandatory. Despite much progress in recent years, in most cases the technology is not yet commercially available. Information-acquisition systems, including sensors, fusion algorithms and data analysis, need to be adjusted to the dynamic conditions of unstructured agricultural environments. Intensive research is needed on integrating human operators into the system control loop for increased system performance and reliability. System sizes should be reduced while improving the integration of all parts and components. For robots to perform in agricultural environments and execute agricultural tasks, research must focus on: fusing complementary sensors for adequate localisation and sensing abilities, developing simple manipulators for each agricultural task, developing path planning, navigation and guidance algorithms suited to environments besides open fields and known a-priori, and integrating human operators in this complex and highly dynamic situation.

      PubDate: 2016-07-17T15:06:15Z
  • Integration of visible branch sections and cherry clusters for detecting
           cherry tree branches in dense foliage canopies
    • Abstract: Publication date: September 2016
      Source:Biosystems Engineering, Volume 149
      Author(s): Suraj Amatya, Manoj Karkee
      To minimise the demand for seasonal workers in sweet cherry production, there is a need to develop automated harvesting systems. The first step in automating a shake-and-catch type harvesting system is to develop a machine vision system for detecting tree branches and localising shaking points in those branches. In this study, an image processing algorithm was developed to detect branches of cherry trees using segmentation of branch and cherry pixels. Firstly, partially visible branch segments within the tree canopies were connected using morphological features of the segments to form whole branches. Then, the positions of cherry clusters in the canopy were used as an indication to detect branch sections that were occluded by cherries and leaves. Different cherry clusters were grouped together based on their spatial location and distance between them. Branch equations were then defined through those cherry clusters using minimum residual criteria. Overall, 93.8% branches were detected in a Y-trellis fruiting wall cherry orchard, with 55.0% of branches detected using only branch pixels and 38.8% additional branches detected using cherry clusters. The method resulted in a total of 12.4% of false positive detection. The results showed that branch detection accuracy can be substantially improved by integrating cherry location information with the location of segments of partially visible branches. This study has shown the potential of machine vision systems to detect cherry tree branches in full foliage season, which is highly promising for the development of automated sweet cherry harvesting systems.

      PubDate: 2016-07-17T15:06:15Z
  • Soil physical property estimation from soil strength and apparent
           electrical conductivity sensor data
    • Abstract: Publication date: Available online 16 July 2016
      Source:Biosystems Engineering
      Author(s): Yongjin Cho, Kenneth A. Sudduth, Sun-Ok Chung
      Proximal soil sensing is an attractive approach for quantifying soil properties, but many currently available sensors do not respond to a single soil property. For example, soil strength and apparent electrical conductivity (ECa) sensor measurements are significantly affected by soil texture, bulk density (BD), and water content (WC). The objective of this study was to explore the potential for estimating soil texture, BD, and WC using combinations of sensor-based soil strength and ECa data obtained from sites with varying soil physical properties. Data collected from three research sites in Missouri included on-the-go horizontal soil strength at five depths up to 0.5 m on a 0.1-m interval, cone index measurements at the same depths, ECa measured by a Veris 3100, and depth-dependent, laboratory-determined soil properties. An ECa model inversion approach was used to generate layer EC values corresponding to the depth increments of the other variables. Fits of models using EC to estimate WC were variable (R2 = 0.31–0.79). Best fitting BD estimation models (R2 = 0.11–0.55) generally included EC, but soil strength was included in fewer than half of the models. BD model fits were improved considerably by adding lab-measured WC to the model (R2 = 0.30–0.86), suggesting the need for a WC sensor. Soil clay texture fraction models based on EC and WC fit well (R2 = 0.80–0.93). This study showed the potential of combining data from multiple mobile proximal sensors to estimate important soil physical properties.

      PubDate: 2016-07-17T15:06:15Z
  • Assessment of soil properties in situ using a prototype portable MIR
           spectrometer in two agricultural fields
    • Abstract: Publication date: Available online 5 July 2016
      Source:Biosystems Engineering
      Author(s): Wenjun Ji, Viacheslav I. Adamchuk, Asim Biswas, Nandkishor M. Dhawale, Bharath Sudarsan, Yakun Zhang, Raphael A. Viscarra Rossel, Zhou Shi
      Mid-infrared (MIR) soil spectroscopy has shown applicability to predict selected properties through various laboratory studies. However, reports on the successful use of MIR instruments in field conditions (in situ) have been limited. In this study, a small portable prototype MIR (898–1811 cm−1) spectrometer was used to collect soil spectra from two agricultural fields (predominantly organic and mineral soils). Both fields were located at Macdonald Campus of McGill University in Ste-Anne-de-Bellevue, Quebec, Canada. In each of the 120 predefined field locations, in situ spectroscopic measurements were repeated three times and one representative soil sample was analyzed following conventional laboratory procedures. For every soil property, a field-specific partial least squares regression (PLSR) model was developed and evaluated using a leave-one-out cross-validation routine. Each soil property was evaluated in terms of the accuracy and reproducibility of model predictions. Among tested soil properties, soil organic matter, water content, bulk density, cation exchange capacity (CEC), Ca and Mg yielded higher model performance indicators (R2 > 0.50 and RPD > 1.40) as compared to soil pH, Fe, Cu, phosphorus, nitrate-nitrogen, K or Na. In most instances, the error estimate representing the prediction reproducibility was found to be as high as 50% of the overall prediction error. This was due to the combination of optical and electrical noise and soil micro-variability causing soil spectra representing the same field location to yield different predictions.

      PubDate: 2016-07-08T23:01:51Z
  • Editorial Board
    • Abstract: Publication date: August 2016
      Source:Biosystems Engineering, Volume 148

      PubDate: 2016-07-08T23:01:51Z
  • Experiments and discrete element method simulations of distribution of
           static load of grain bedding at bottom of shallow model silo
    • Abstract: Publication date: September 2016
      Source:Biosystems Engineering, Volume 149
      Author(s): Józef Horabik, Piotr Parafiniuk, Marek Molenda
      The influences of a filling method, seed size and seed aspect ratio on the radial distribution of the vertical pressure at the bottom of a shallow model silo were studied. Two filling methods were applied: central and circumferential. Seeds of five varieties were used: horse bean (Vicia faba), field pea (Pisum sativum), wheat (Triticum), vetch (Vicia) and rapeseed (Brassica napus). The vertical pressure at the bottom was influenced by the filling methods and seed size. A significant dip in the vertical pressure near the centre of the silo radius was observed in each experimental case except the rapeseed case. Discrete element method (DEM) simulations confirmed the impact of the filling methods on the pressure distribution. The pressure increased with increasing radius for central filling and decreased with increasing radius for circumferential filling. DEM simulations of filling with higher particle kinetic energies produced the greatest vertical pressures near the centre of the silo radius, whereas the lowest values were located close to the silo centre and wall.
      Graphical abstract image

      PubDate: 2016-07-08T23:01:51Z
  • In-situ plant hyperspectral sensing for early detection of soybean injury
           from dicamba
    • Abstract: Publication date: September 2016
      Source:Biosystems Engineering, Volume 149
      Author(s): Yanbo Huang, Lin Yuan, Krishna N. Reddy, Jingcheng Zhang
      Drift of dicamba onto non-target crops is a major concern because it is highly active on susceptible crops even at low doses. Early detection of crop injury is critical in crop management. A field study was conducted to determine spectral characteristics of soybean (Progeny P4819LL) treated with dicamba. Drift deposition of dicamba was simulated by direct application at 0.05 to 1.0 times of the recommended label rate (0.56 kg [ai] ha−1) to soybean at the 5- to 6-trifloliolate leaf stage, approximately 6 weeks after planting. The canopy spectral measurements were taken at 24, 48, and 72 h after treatment (HAT) using a portable spectroradiometer in the 325–1075 nm spectral range on 3 randomly selected plants within each plot with device optimisation and data calibration. The results indicated that it was difficult to clearly differentiate the dose response of soybean to different dicamba spray rates within 72 HAT. Regardless of spray rates the soybean treated with dicamba could be clearly differentiated from untreated soybean from 24 to 72 HAT through spectral vegetation index analysis with anthocyanin reflectance and photochemical reflectance indices with accuracies at 24, 48, and 72 HAT ranging from 76 to 86%. Simulated dicamba drift injured soybean and reduced its yield by 71 and 90% at 0.05 and 0.1 times recommended rate, respectively. This study demonstrated that hyperspectral remote sensing has a potential in early detection of soybean injury from exposure to off-target dicamba drift at sub lethal rates in the field.

      PubDate: 2016-07-08T23:01:51Z
  • A mobile, in-situ soil bin test facility to investigate the performance of
           maresha plough
    • Abstract: Publication date: September 2016
      Source:Biosystems Engineering, Volume 149
      Author(s): Solomon Gebregziabher, Karel De Swert, Wouter Saeys, Herman Ramon, Bart De Ketelaere, Abdul M. Mouazen, Kindeya Gebrehiwot, Jozef Deckers, Josse De Baerdemaeker
      Ethiopia is well known for its use of an ard plough dating from antiquity – maresha – which fractures and disturbs the soil. However, hardly any notable progress of experimental research on this animal drawn tillage tool in the field has been made. The attendant problems in current practise are soil-maresha interaction, viz., uneven oxen strength along with different pace of walking, uncontrolled implement behaviour, and field conditions. Taking stock of the experimental research on animal drawn tillage tools in general, most of the documented works on the dynamics of the interaction between soil and animal drawn tillage tools tend to rely on trial-and-error based on factors mainly based on experience and cultural context. As such, no research tailored to systematically handle the link between maresha plough and soil bin experiments exists. To this aim, this study developed a mobile in-situ soil bin facility in which the system was calibrated, tested, and evaluated under outdoor experimental conditions, wherein online measurements of draught, speed, and depth of tillage were carried out. The insights and observations gained from the experimentation were discussed and reported in terms of smooth run, overload, cyclic forces, zero speed with minimal force, stoppage, speed measurement with no force, force measurement with no speed, and low speed with low force.

      PubDate: 2016-07-01T18:28:50Z
  • Methodology for designing accelerated structural durability tests on
           agricultural machinery
    • Abstract: Publication date: September 2016
      Source:Biosystems Engineering, Volume 149
      Author(s): Dimitris S. Paraforos, Hans W. Griepentrog, Stavros G. Vougioukas
      Structural durability assessment is one of the last stages before an agricultural machine prototype reaches the market. Accelerated structural testing (AST) aims at reducing the time and resources required for this stage. According to existing AST methodologies, strain measurements are used to characterise machine loads under real-world operating conditions, and calculate resulting accumulated fatigue damages. An operation profile is defining the conditions to be monitored but also the target damages of the accelerated testing. Next, rainflow cycles are extrapolated to include non-measured high-amplitude loads. Finally, the machine prototype travels on suitable proving grounds to replicate real-world service loads. The number of laps required to reach the target damage values is the result of optimisation, given the fatigue damages accumulated during each lap. In this paper the above AST methodology was implemented on a four-rotor swather, which is an agricultural implement that drastically changes structure configuration during its working life, depending on its operating mode. Furthermore, recognising the fact that the damage accumulated during each lap varies, automated test facilities were utilised, and Monte-Carlo sensitivity analysis was introduced as part of the AST methodology, to study the effects of damage-per-lap variance on the required numbers of laps calculated via optimisation. When average values were used for lap damages, the total testing time was 1228 h with an acceleration factor of 3.3. However, conservative test design using the 99.9th percentile of the testing time simulation results, required 7.1% longer testing time, leading to a lower acceleration factor equal to 3.1.

      PubDate: 2016-07-01T18:28:50Z
  • Comparison of CO2- and SF6- based tracer gas methods for the estimation of
           ventilation rates in a naturally ventilated dairy barn
    • Abstract: Publication date: September 2016
      Source:Biosystems Engineering, Volume 149
      Author(s): Nadège Edouard, Julio Mosquera, Hendrik J.C. van Dooren, Luciano B. Mendes, Nico W.M. Ogink
      Livestock production is a source of numerous environmental problems caused by pollutant gas emissions. In naturally ventilated buildings, estimating air flow rate is complicated due to changing climatic conditions and the difficulties in identifying inlets and outlets. To date no undisputed reference measurement method has been identified. The objective of this paper was to compare CO2- and SF6-based tracer gas methods for the estimation of ventilation rates ( V R C O 2 vs. V R S F 6 ) in naturally ventilated dairy barns both under conventional and very open ventilation situations with different spatial sampling strategies. Measurements were carried out in a commercial dairy barn, equipped with an injection system for the controlled release of SF6, and measurement points for the monitoring of SF6 and CO2 concentrations to consider both horizontal and vertical variability. Methods were compared by analysing daily mean V R C O 2 / V R S F 6 ratios. Using the average gas concentration over the barn length led to more accurate ventilation rates than using one single point in the middle of the barn. For conventional ventilation situations, measurements in the ridge seem to be more representative of the barn average than in the middle axis. For more open situations, both V R C O 2 and V R S F 6 were increased, V R C O 2 / V R S F 6 ratios being also more variable. Generally, both methods for the estimation of ventilation rates gave similar results, being 10–12% lower with the CO2 mass balance method compared to SF6 based measurements. The difference might be attributed to potential bias in both methods.

      PubDate: 2016-06-26T18:04:16Z
  • Non-destructive measurement of nitrogen status of leafy ornamental
           cuttings by near infrared reflectance spectroscopy (NIRS) for assessment
           of rooting capacity
    • Abstract: Publication date: August 2016
      Source:Biosystems Engineering, Volume 148
      Author(s): Dieter Lohr, Peter Tillmann, Siegfried Zerche, Uwe Druege, Thomas Rath, Elke Meinken
      An adequate nitrogen supply to stock plants is a well-known key factor in adventitious root formation of herbaceous ornamental cuttings. Both slight deficiency and luxury amount of nitrogen in the tissue can impair rooting. Due to a lack of fast, cheap and reliable analytical methods, parameters characterising the nitrogen status of cuttings are not used as quality indicators. Near infrared reflectance spectroscopy (NIRS) might bridge this gap, especially if sample preparation such as drying or grinding is avoided. NIR spectra of intact chrysanthemum and pelargonium cuttings were taken and partial least square regression models were developed for various nitrogen fractions as well as for total nitrogen. Calibration equations with high prediction performance were developed for insoluble, organic and total nitrogen (R2 > 0.8). Calibration models for various soluble nitrogen fractions were at least suitable for a rough screening (R2 > 0.6). In a second experiment, calibration models were extended to poinsettia, impatiens and osteospermum cuttings by adding a few samples to the calibration data set. Thus, analysing nitrogen status of ornamental cuttings by NIRS might be a valuable tool for optimisation of stock plant cultivation and assessment of rooting capacity of cuttings.

      PubDate: 2016-06-26T18:04:16Z
  • Effects of temperature and material on sensing moisture content of
           pelleted biomass through dielectric properties
    • Abstract: Publication date: September 2016
      Source:Biosystems Engineering, Volume 149
      Author(s): Murat Sean McKeown, Samir Trabelsi, Ernest William Tollner
      The production of pelleted biomass represents a significant emerging industry in the United States. Solid biomass can be formed from the waste products of different natural and manufactured products. In this study, the effects of temperature and pellet material type on the dielectric properties were investigated. The resulting information was used to develop temperature- and material-independent moisture prediction equations. Dielectric properties of peanut-hull, pine, and hardwood pellets were measured at microwave frequencies for temperatures between 10 °C and 50 °C and at moisture contents between 4.9% and 16.0%. Further work was performed in investigating the dielectric properties of pine, peanut-hull, and hardwood pellets to determine whether a “unified” calibration for moisture content might be developed. Results showed that a temperature-compensated calibration for moisture content could be developed for different pellet types with standard errors of calibration between 0.50% and 1.04%. In addition, a unified calibration for pine, peanut-hull and hardwood pellets at 20 °C was developed that provides moisture content for the materials with a standard error of calibration between 0.48% and 0.56%.

      PubDate: 2016-06-26T18:04:16Z
  • Estimation of the density of pomegranate fruit and their fractions using
           X-ray computed tomography calibrated with polymeric materials
    • Abstract: Publication date: August 2016
      Source:Biosystems Engineering, Volume 148
      Author(s): Ebrahiema Arendse, Olaniyi Amos Fawole, Lembe Samukelo Magwaza, Umezuruike Linus Opara
      The application of microfocus X-ray computed tomography (μCT) with a density calibration with homogenous polymeric materials ranging from 910 to 2150 kg m−3 and its accuracy for differentiating fruit fractions (albedo and arils) and the effects of detecting false codling moth and blackheart disease in pomegranate fruit was investigated. A commercial microfocus X-ray (μCT) system in combination with image analysis techniques was used to generate two-dimensional (2-D) radioscopic images which were reconstructed into three dimensional (3-D) images. Optimum μCT settings were obtained using an isotropic voxel size of 71.4 μm based on a radiation source generated from a voltage of 100 kV with the electric current set at 200 μA. The density of whole pomegranate fruit, its fractions (arils and albedo), false codling moth, and blackheart infected portions were successfully determined within the calibration range. Furthermore, the density of larva moth (9400 ± 40 kg m−3) were found to be significantly (p < 0.0001) lower than whole fruit (1070 ± 20 kg m−3) and fruit fractions (arils 1120 ± 40 kg m−3 and albedo 1040 ± 30 kg m−3). Similarly, the differentiation between healthy and blackheart affected fruit was successfully accomplished. The density of healthy fruit was significantly (p < 0.0001) higher (1070 ± 20 kg m−3) than that of fruit affected by blackheart which ranged from 870 to 1000 kg m−3. The results thus demonstrated that X-ray μCT with associated algorithm can be used to accurately detect and quantify internal defects caused by false codling moth and blackheart disease in pomegranate fruit.

      PubDate: 2016-06-22T17:52:01Z
  • Editorial Board
    • Abstract: Publication date: July 2016
      Source:Biosystems Engineering, Volume 147

      PubDate: 2016-06-22T17:52:01Z
  • Thank you to reviewers
    • Abstract: Publication date: July 2016
      Source:Biosystems Engineering, Volume 147

      PubDate: 2016-06-22T17:52:01Z
  • Detection of cucumber green mottle mosaic virus-infected watermelon seeds
           using a near-infrared (NIR) hyperspectral imaging system: Application to
           seeds of the “Sambok Honey” cultivar
    • Abstract: Publication date: August 2016
      Source:Biosystems Engineering, Volume 148
      Author(s): Hoonsoo Lee, Moon S. Kim, Hyoun-Sub Lim, Eunsoo Park, Wang-Hee Lee, Byoung-Kwan Cho
      The cucurbit diseases caused by cucumber green mottle mosaic virus (CGMMV) have led to a serious problem to growers and seed producers because it is difficult to prevent spreading through pathogen-infected seeds. Conventional detection methods for infected seeds such as biological, serological, and molecular measurements are not practical for measuring entire samples due to their destructive nature, and time, and cost issues. For this reason, it is necessary to develop a rapid and non-destructive novel technique for detecting seeds infestation. A near-infrared (NIR) hyperspectral imaging system was used to discriminate virus-infected seeds from healthy seeds with partial least square discriminant analysis (PLS-DA) and least square support vector machine (LS-SVM). The classification accuracy for virus-infected watermelon seeds were 83.3% with the best model, demonstrating the potential of NIR hyperspectral imaging for detection of virus-infected watermelon seeds.

      PubDate: 2016-06-18T18:00:44Z
  • Detecting tomatoes in greenhouse scenes by combining AdaBoost classifier
           and colour analysis
    • Abstract: Publication date: August 2016
      Source:Biosystems Engineering, Volume 148
      Author(s): Yuanshen Zhao, Liang Gong, Bin Zhou, Yixiang Huang, Chengliang Liu
      Despite the rapid development of agricultural robotics, a lack of access to automatic fruit detection and precision picking is limiting the commercial application of harvesting robots. An algorithm for the automatic detection of ripe tomatoes in greenhouse was developed for a simple machine vision system. The images of tomato planting scenes were captured by a colour digital camera, and most of the ripe tomatoes were correctly recognised using the proposed algorithm. The proposed tomato detection approach worked in two steps: (1) by extracting the Haar-like features of grey scale image and classifying with the AdaBoost classifier, the possible tomato objects were identified; (2) the false negatives in the results of classification were eliminated using average pixel value (APV) based colour analysis approach. Comparative test results showed that the C style of Haar-like features and I component image were optimum in the proposed algorithm. The results of validation experiments show that combination of AdaBoost classification and colour analysis can correctly detect over 96% of ripe tomatoes in the real-world environment. However, the false negative rate was about 10% and 3.5% of the tomatoes were not detected.

      PubDate: 2016-06-14T13:10:36Z
  • Front end loader with automatic levelling for farm tractors
    • Abstract: Publication date: August 2016
      Source:Biosystems Engineering, Volume 148
      Author(s): Juan I. Latorre-Biel, Ignacio Arana, Tomás Ballesteros, Jesús M. Pintor, José R. Alfaro
      One of the most commonly used accessories in multiple applications with farm tractors is the front end loader. There is a broad variety of loaders that can offer a range of possibilities and advantages to the operator. Depending on the task to be developed, the functionality that the operator requests from the loader may be different. Nevertheless, in order to avoid significant loss of product during transport, in most applications it is desirable for the loader to be level throughout its movement. In this paper, a new methodology for achieving a high quality levelling is described. This methodology, when compared to the alternative options that can be found in the market, presented favourable features. The proposed methodology could be implemented at affordable cost by using a reduced set of inexpensive components and can be applied to both new and old tractors.

      PubDate: 2016-06-14T13:10:36Z
  • Compression and relaxation properties of selected biomass for briquetting
    • Abstract: Publication date: August 2016
      Source:Biosystems Engineering, Volume 148
      Author(s): Lei Guo, Decheng Wang, Lope G. Tabil, Guanghui Wang
      Compression and relaxation properties of selected biomass for briquetting (barley, oat, canola and wheat straw) were investigated to determine the correlation with variables (pressure, particle size (hammer mill screen size) and moisture contents). The applied pressure ranged from 7.03 to 14.06 MPa. Three hammer mill screen sizes (19.05, 25.40 and 31.75 mm) were used to grind the biomass samples. The ground biomass materials were conditioned to moisture contents of 9%, 12% and 15% (w.b.). The results indicated that the compact density of biomass increased with increasing pressure and moisture content. The relaxation properties of selected materials were affected by the set variables. Biomass materials had a higher stress relaxation speed with higher applied pressure and lower moisture content.

      PubDate: 2016-06-14T13:10:36Z
  • Droplet characterisation of a complete fluidic sprinkler with different
           nozzle dimensions
    • Abstract: Publication date: August 2016
      Source:Biosystems Engineering, Volume 148
      Author(s): Junping Liu, Xingfa Liu, Xingye Zhu, Shouqi Yuan
      The complete fluidic sprinkler (CFS) has the advantages of a simple structure and the ability to work well at a lower nozzle pressures. CFS is a gas–liquid fluidic sprinkler, whose driving moment is achieved by a flow reaction as a result its droplet characteristics differ from those of conventional sprinklers. To study the droplet characteristics of the CFS, droplet diameter and velocity were measured using a Thies Clima laser precipitation monitor (TCLPM). Statistical analysis was conducted on the droplet size distribution using a volume-weighted method and droplet velocity was analysed using a number-weighted method. The results showed that volume mean droplet diameter and volume medium diameter increased with the distance from the nozzle and decreased with the nozzle size. The frequency of droplets with a diameter <3 mm increased with the working pressure. The number of larger droplets decreased with pressure and increased with the nozzle size when the pressure was 0.25, 0.30, or 0.35 MPa. A lognormal distribution model was used to evaluate the drop diameter distribution for each observed distance. With increasing pressure, the slope of the cumulative volume frequency droplet size curve at different distances from the nozzle decreased, and the distribution followed the trend of a Boltzmann function distribution. Droplet velocity increased with the droplet diameter but was not significantly influenced by the nozzle pressure. The results may provide a basis for further systematic research on the CFS.

      PubDate: 2016-06-14T13:10:36Z
  • Methodology to analyse farm tractor idling time
    • Abstract: Publication date: August 2016
      Source:Biosystems Engineering, Volume 148
      Author(s): Daniela Perozzi, Michele Mattetti, Giovanni Molari, Eugenio Sereni
      Actual in-service damage to tractor engines could be different from that predicted according to other estimates due to the difficulties in evaluating all the information necessary to completely define the mission profile. Among the different parameters which could be measured or estimated, the idling duration is one of the most influential factors in the calculation of in-service damage. In this paper, a methodology to estimate the idling time from signals recorded through a data logger interfaced to the vehicle-bus is proposed. Through statistical methods, the idling duration distribution was identified for a fleet of 61 New Holland T9 farm tractors used in Europe and in North America. Starting from these distributions the percentiles have been estimated. The recorded values of idling duration range from 5% up to 50% and the average value is about 20% of the tractor life. Furthermore, 97.5% of the analysed tractors run under idling condition for greater than 10% of the whole life of the machine. All tractors have made at least a stop shorter than 1920 s, while not all have made a stop longer than 1920 s. From the analysis, tractors located in areas with extreme temperatures have run under idling conditions for a longer time to keep the cab comfortable or to maintain the engine on temperature. This data confirms the importance to considering the geographical distribution of the machines and the necessity of performing a wide acquisition campaign to define the tractor mission profile.

      PubDate: 2016-06-14T13:10:36Z
  • Field phenotyping system for the assessment of potato late blight
           resistance using RGB imagery from an unmanned aerial vehicle
    • Abstract: Publication date: August 2016
      Source:Biosystems Engineering, Volume 148
      Author(s): Ryo Sugiura, Shogo Tsuda, Seiji Tamiya, Atsushi Itoh, Kentaro Nishiwaki, Noriyuki Murakami, Yukinori Shibuya, Masayuki Hirafuji, Stephen Nuske
      In tests for field resistance of potato (Solanum tuberosum L.) to late blight, crop scientists rate the disease severity exclusively using visual examinations of infections on the leaves. However, this visual assessment is generally time-consuming and quite subjective. The objective of this study was to develop a new estimation technique for disease severity in a field using RGB imagery from an unmanned aerial vehicle (UAV). For the assessment of disease resistance of potatoes a test field was designed that consisted of 262 experimental plots on which various cultivars and lines were planted. From mid-July to mid-August in 2012, conventional visual assessment of disease severity was conducted while 11 aerial images of the field were obtained. The disease severity was estimated using an image processing protocol developed in this study. This estimation method was established so that the error of the severity estimated by image processing was minimal when compared with the visual assessment. Comparing the area under the disease progress curves (AUDPCs) calculated from the visual assessment and time series of images, the coefficient of determination was 0.77. A further experiment was conducted to validate the developed method. Eleven images of a field planted the following year were taken, and the resulting coefficient of determination was 0.73. The breeders concluded that these correlations were acceptable and that the UAV image acquisition and the disease severity estimation from the image were more efficient than the conventional visual assessments. Therefore, the developed technique based on aerial imagery allows high throughput, objective, and precise phenotyping with regard to field resistance to potato late blight.

      PubDate: 2016-06-14T13:10:36Z
  • Remote detection of the swarming of honey bee colonies by single-point
           temperature monitoring
    • Abstract: Publication date: August 2016
      Source:Biosystems Engineering, Volume 148
      Author(s): Aleksejs Zacepins, Armands Kviesis, Egils Stalidzans, Marta Liepniece, Jurijs Meitalovs
      Precision Beekeeping (or Precision Apiculture) aims to help beekeepers monitor bee colonies remotely and identify different colony states including deviant behaviour. One monitoring target is the remote identification of bee colony swarming since this is one of the factors that can significantly reduce profitability. To identify temperature dynamics and its patterns for swarming detection, ten colonies were constantly monitored for four months from 1 May to 31 August 2015. Nine swarms were observed during experiments. During the warm-up stage, in the last 10–20 min before take-off, a temperature rise by 1.5–3.4 °C from typical range 34–35 °C to range 37–38 °C was registered by a temperature sensor placed above the polyethylene foil covering the upper hive body under the pillow. For all swarming events it was common that a bee colony needs a relatively small amount of time (from 8 to 20 min) to warm up before take-off. It was concluded that a single temperature sensor above the bee nest combined with a proposed decision support algorithm can be used for automatic remote detection of swarming at take-off stage.

      PubDate: 2016-06-14T13:10:36Z
  • Effects of an extended c-phase on vacuum conditions in the milking cluster
    • Abstract: Publication date: August 2016
      Source:Biosystems Engineering, Volume 148
      Author(s): Franziska E. Bluemel, Pascal E. Savary, Matthias E. Schick
      The objective of this study was to examine how a prolonged closing phase in the pulsation chamber cycle would affect vacuum conditions on the teat and liner movement. Wrong vacuum conditions and liner movements, controlled by pulsators, could cause discomfort on the teats and have negative effects on udder health. Therefore, 18 focal dairy cows were randomly subjected to two types of pulsation chamber cycles (treatments A and B) for 12 milkings in a low-line 2 × 3 auto tandem milking parlour. The treatments differed in the duration of closing and closed phases (c- and d-phases, respectively). In treatment A, the c-phase was 70 ms and the d-phase was 330 ms, whereas in treatment B, the c-phase lasted 130 ms and the d-phase 270 ms. Using a vacuum measuring device, measurement series with 5 s intervals were conducted during three phases of the milking process: the plateau phase, the decreasing phase, and the over-milking phase. Differences between the treatments were detected in the total pressure per cycle and maximum vacuum on the teat-end. Treatment B showed on average a 1 kPa s lower total pressure per cycle than treatment A, whereas values of maximum vacuum at the teat-end were on average 0.2 kPa higher in Treatment B than A. Further, differences could be detected between the three phases during the milking proceedings, showing that the observed parameters were related to the milk flow rate. The results indicate that treatment B might be gentler and more comfortable for dairy cows, which will be established next.

      PubDate: 2016-06-14T13:10:36Z
  • An experimental system for extraction of pectin from orange peel waste
           based on the o-core transformer structure
    • Abstract: Publication date: August 2016
      Source:Biosystems Engineering, Volume 148
      Author(s): Na Yang, Yamei Jin, Yaoqi Tian, Zhengyu Jin, Xueming Xu
      An experimental system based on the o-core transformer structure was established and used to extract pectin from orange peel waste. Unlike other electric-field-assisted techniques, it avoids the use of powered electrodes. The acidic solvent acts as the secondary coil connected to a purpose-made glass chamber which forms a closed loop. Then the induced electric field in the system appears to be under the influence of alternating magnetic flux based on Faraday's law of induction. We found that an increase in the excitation voltage causes enhancement of the pectin yield. Increasing frequency from 20 to 200 kHz had a negative impact on pectin yield partially due to the increased impedance of the primary coil. The ionic conduction was enhanced at the same excitation voltage since there are more free ions in the mixture at lower pH. This means that a lower impedance in the mixture is conducive to extraction. This multidisciplinary technique combines the transformer concept with the electric-field-assisted process, thus providing a reference for the application into agricultural by-products treatment.

      PubDate: 2016-06-14T13:10:36Z
  • Temperature distribution in a packed-bed of canola seeds with various
           moisture contents and bulk volumes during radio frequency (RF) heating
    • Abstract: Publication date: August 2016
      Source:Biosystems Engineering, Volume 148
      Author(s): Daeung Yu, Bijay L. Shrestha, Oon-Doo Baik
      This research investigated temperature distribution in a packed-bed of canola seeds at various moisture contents (5%, 7%, 9%, and 11% wet weight basis) and bulk volumes (small – 196.3 cm3, medium – 1766 cm3, and large – 6503 cm3) during RF heating (1.5 kW, 27.12 MHz). The samples were contained in RF-transparent cylindrical and rectangular sample holders. The RF exposure time required to reach a specific temperature decreased with seed moisture content (MC). The hottest spot (80 °C) was detected at the geometric center of the small and large volume canola seeds, but away from the geometric center and towards the edge of the medium volume canola seeds due to the edge effect. The temperature uniformity index values indicated that the most uniform RF heating was observed in the medium volume canola seeds in spite of the edge effect. The highest temperatures occurred between the middle and outer regions of the medium volume canola seeds. RF heating and thermal imaging were used to obtain temperature profiles for 2% agar gels in small, medium and large holders. The temperature profiles for the gels supported the observations made for the canola seeds.

      PubDate: 2016-06-14T13:10:36Z
  • Multi-tree woody structure reconstruction from mobile terrestrial laser
           scanner point clouds based on a dual neighbourhood connectivity graph
    • Abstract: Publication date: August 2016
      Source:Biosystems Engineering, Volume 148
      Author(s): Valeriano Méndez, Joan R. Rosell-Polo, Miquel Pascual, Alexandre Escolà
      A process is presented for the vector reconstruction of fruit plantations based on the model developed by Verroust and Lazarus. To solve occlusion problems, the use of a dual graph of local and extended connectivity is proposed. The process allows vegetation variables such as the length and volume of the ligneous structure to be measured, enabling studies such as intensity of pruning operations. The process has been tested against simulated models and real trees with different training systems: open-vase system (peach trees) and central leader hedgerow system (pear trees). The cost of the algorithm will be given by the cost of the implementation of Dijkstra's algorithm, which in its standard version is of potential ( O ( n 2 ) ). Algorithm accuracy was checked against point clouds of virtual trees. The reconstruction was also applied before and after a pruning operation of real trees to enable a study of the evolution of the vegetation indices. Results showed the algorithm to be suitable for multi-tree reconstruction of both central leader and open-vase training systems.

      PubDate: 2016-06-14T13:10:36Z
  • Dust explosions in an experimental test silo: Influence of length/diameter
           ratio on vent area sizes
    • Abstract: Publication date: August 2016
      Source:Biosystems Engineering, Volume 148
      Author(s): Alberto Tascón, Álvaro Ramírez-Gómez, Pedro J. Aguado
      Vented dust explosion tests have been conducted in an experimental test silo in order to analyse the effect of the length/diameter ratio (L/D). The modular design of the silo permitted the assembling of four different vessels with different geometries. The tests were carried out with wheat flour and maize starch, using three different vent area sizes. The silo was equipped with instrumentation which recorded the pressure generated by the explosion at various points in the silo, as well as the instant when the vent panel opened. The length/diameter ratio has been included in the empirical correlations currently employed in standards EN 14491 and NFPA 68 for calculating the size of vents. However, there are marked differences between the two standards when applied to certain situations, in part due to a different vent area correction for slenderness. The results obtained in this experimental test programme were compared with the standards, and indicated the advisability of applying an increase in vent area in elongated vessels when L/D > 1, as stated in EN 14491. However, this same standard appears to apply an excessively severe correction in some situations.
      Graphical abstract image

      PubDate: 2016-06-14T13:10:36Z
  • An adaptively controlled modified atmosphere container system for fresh
    • Abstract: Publication date: August 2016
      Source:Biosystems Engineering, Volume 148
      Author(s): Ji Hye Lee, Duck Soon An, Jae Min Song, Yong Bae Jung, Dong Sun Lee
      Time-variable open/close cycles of a gas diffusion tube may serve as a means to supply the desired gas transfer to attain a beneficial modified atmosphere (MA) in fresh produce containers. Because the produce respiration contributing to the atmosphere modification changes over time, adoption of real-time respiration in the open/close control of the tube may be an innovative tool to maintain the container atmosphere. An adaptive control of the tube responding to the real-time respiration of fresh produce was developed based on a simplified O2 mass balance to generate and maintain the desired MA for the fresh produce. Here, the O2 concentration change in the initially closed container before reaching the target value was used to calculate the respiration rate to determine the starting value of the opening ratio of the cycle time and the average O2 concentration of each cycle after reaching the target value once was used in the mass balance relationship to update the opening ratio for the next cycle. The developed MA container system could attain the targeted O2 concentrations and the expected desirable CO2 concentrations for blueberries and spinach at steady state, helping to preserve their quality.
      Graphical abstract image

      PubDate: 2016-06-14T13:10:36Z
  • Parameters and contact models for DEM simulations of agricultural granular
           materials: A review
    • Abstract: Publication date: July 2016
      Source:Biosystems Engineering, Volume 147
      Author(s): Józef Horabik, Marek Molenda
      The discrete element method has been in development since 1970s and has recently found practical application in simulations of granular assemblies to investigate natural phenomena as well as a design tool for technology. Agriculture and food engineering harvests, stores, handles or processes an enormous amount of particulate material of biological origin. Unlike mineral or plastic granular materials, these materials are usually hygroscopic and change their mechanical properties through the absorption of moisture. Information regarding material properties of granular materials of biological origin is insufficient, uncertain and dispersed across various journals. This review presents a collection of material properties that are useful for discrete element method, DEM, simulations gathered from contributions of various laboratories around the world. Peculiar behaviour of materials of biological origin requires not only a specific approach in determining the parameters but also a specific setup of simulations. This article presents findings that appear efficient at the current stage of development of granular mechanics and DEM simulations. Emerging trends in the evolution of DEM are also presented.
      Graphical abstract image

      PubDate: 2016-05-15T13:17:54Z
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