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  Subjects -> AGRICULTURE (Total: 785 journals)
    - AGRICULTURAL ECONOMICS (69 journals)
    - AGRICULTURE (550 journals)
    - CROP PRODUCTION AND SOIL (92 journals)
    - DAIRYING AND DAIRY PRODUCTS (28 journals)
    - POULTRY AND LIVESTOCK (46 journals)

AGRICULTURE (550 journals)                  1 2 3 | Last

Showing 1 - 200 of 263 Journals sorted alphabetically
Aceh International Journal of Science and Technology     Open Access   (Followers: 2)
Acta agriculturae Slovenica     Open Access   (Followers: 4)
Acta Agrobotanica     Open Access   (Followers: 4)
Acta Agronomica Hungarica     Full-text available via subscription   (Followers: 2)
Acta Agronomica Sinica     Full-text available via subscription   (Followers: 5)
Acta Biologica Sibirica     Open Access  
Acta Scientiarum. Animal Sciences     Open Access   (Followers: 2)
Acta Scientiarum. Technology     Open Access   (Followers: 3)
Acta Technologica Agriculturae     Open Access   (Followers: 1)
Acta Universitatis Sapientiae, Alimentaria     Open Access   (Followers: 1)
Advances in Agriculture     Open Access   (Followers: 7)
Advances in Agriculture & Botanics     Open Access   (Followers: 14)
Advances in Agronomy     Full-text available via subscription   (Followers: 15)
Advances in Life Science and Technology     Open Access   (Followers: 14)
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: 5)
African Journal of Food, Agriculture, Nutrition and Development     Open Access   (Followers: 15)
African Journal of Range & Forage Science     Hybrid Journal   (Followers: 6)
Agra Europe     Full-text available via subscription   (Followers: 3)
Agribusiness : an International Journal     Hybrid Journal   (Followers: 6)
Agricultura     Open Access   (Followers: 1)
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: 18)
Agricultural Commodities     Full-text available via subscription  
Agricultural Economics     Hybrid Journal   (Followers: 44)
Agricultural History Review     Full-text available via subscription   (Followers: 9)
Agricultural Research     Hybrid Journal   (Followers: 3)
Agricultural Science     Open Access   (Followers: 2)
Agricultural Science     Full-text available via subscription   (Followers: 5)
Agricultural Sciences     Open Access   (Followers: 7)
Agricultural Systems     Hybrid Journal   (Followers: 30)
Agricultural Water Management     Hybrid Journal   (Followers: 38)
Agriculture     Open Access   (Followers: 7)
Agriculture & Food Security     Open Access   (Followers: 12)
Agriculture (Poľnohospodárstvo)     Open Access   (Followers: 2)
Agriculture and Agricultural Science Procedia     Open Access  
Agriculture and Food Sciences Research     Open Access   (Followers: 4)
Agriculture and Human Values     Hybrid Journal   (Followers: 12)
Agriculture, Ecosystems & Environment     Hybrid Journal   (Followers: 53)
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: 11)
Agrosearch     Open Access   (Followers: 1)
Akademik Ziraat Dergisi     Open Access  
Alinteri Zirai Bilimler Dergisi : Alinteri Journal of Agricultural Sciences     Open Access  
Ambiência     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: 27)
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 Sciences     Open Access   (Followers: 2)
Annals of Silvicultural Research     Open Access   (Followers: 1)
Annals Valahia University of Targoviste - Agriculture     Open Access  
Annual Review of Resource Economics     Full-text available via subscription   (Followers: 12)
APCBEE Procedia     Partially Free   (Followers: 1)
Applied Financial Economics Letters     Hybrid Journal   (Followers: 8)
Arboricultural Journal : The International Journal of Urban Forestry     Hybrid Journal   (Followers: 7)
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: 1)
Asian Economic Papers     Hybrid Journal   (Followers: 7)
Asian Journal of Agricultural Research     Open Access   (Followers: 4)
Asian Journal of Medical and Biological Research     Open Access   (Followers: 2)
Asian Journal of Plant Sciences     Open Access   (Followers: 3)
Australian Cottongrower, The     Full-text available via subscription   (Followers: 1)
Australian Economic Papers     Hybrid Journal   (Followers: 25)
Australian Economic Review     Hybrid Journal   (Followers: 6)
Australian Forest Grower     Full-text available via subscription   (Followers: 3)
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: 3)
Australian Journal of Agricultural Engineering     Open Access   (Followers: 1)
Australian Sugarcane     Full-text available via subscription  
Avances en Investigacion Agropecuaria     Open Access   (Followers: 1)
Bangladesh Agronomy Journal     Open Access   (Followers: 1)
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: 5)
Biodiversity     Hybrid Journal   (Followers: 27)
Biodiversity : Research and Conservation     Open Access   (Followers: 26)
Biological Agriculture & Horticulture : An International Journal for Sustainable Production Systems     Partially Free   (Followers: 12)
Biosystems Engineering     Hybrid Journal   (Followers: 8)
Biotecnología en el Sector Agropecuario y Agroindustrial     Open Access  
Biotemas     Open Access  
Boletín Semillas Ambientales     Open Access  
Bragantia     Open Access   (Followers: 2)
Brazilian Archives of Biology and Technology     Open Access   (Followers: 3)
British Poultry Science     Hybrid Journal   (Followers: 4)
Buletin Peternakan : Bulletin of Animal Science     Open Access  
Buletin Veteriner Udayana     Open Access   (Followers: 2)
Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca : Food Science and Technology     Open Access  
Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca. Agriculture     Open Access  
Caderno de Ciências Agrárias     Open Access  
Cahiers Agricultures     Open Access  
California Agriculture     Open Access   (Followers: 2)
Cambridge Journal of Economics     Hybrid Journal   (Followers: 58)
Canadian Water Resources Journal     Hybrid Journal   (Followers: 21)
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: 16)
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   (Followers: 1)
Ciência e Técnica Vitivinícola     Open Access  
Ciencia forestal en México     Open Access  
Ciência Rural     Open Access   (Followers: 2)
Ciencia y Agricultura     Open Access  
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   (Followers: 2)
Competition & Change     Hybrid Journal   (Followers: 10)
Computers and Electronics in Agriculture     Hybrid Journal   (Followers: 4)
Contributions to Tobacco Research     Open Access   (Followers: 2)
Corps et culture     Open Access   (Followers: 5)
Cuadernos de Desarrollo Rural     Open Access   (Followers: 1)
Cultivos Tropicales     Open Access  
Cultural Geographies     Hybrid Journal   (Followers: 18)
Cultural Sociology     Hybrid Journal   (Followers: 31)
Cultural Studies - Critical Methodologies     Hybrid Journal   (Followers: 15)
Cultural Studies of Science Education     Hybrid Journal   (Followers: 5)
Cultural Trends     Hybrid Journal   (Followers: 15)
Culture, Agriculture, Food and Environment     Hybrid Journal   (Followers: 12)
Culture, Agriculture, Food and Environment     Hybrid Journal   (Followers: 6)
Current Agricultural Science and Technology     Open Access  
Current Agriculture Research Journal     Open Access   (Followers: 1)
Current Life Sciences     Open Access   (Followers: 3)
Current Research in Dairy Sciences     Open Access   (Followers: 5)
Developments in Agricultural Economics     Full-text available via subscription   (Followers: 4)
Developments in Agricultural Engineering     Full-text available via subscription   (Followers: 1)
Diatom Research     Hybrid Journal   (Followers: 2)
Die Bodenkultur : Journal of Land Management, Food and Environment     Open Access  
Dossiers Agraris     Open Access  
Ecological Applications     Full-text available via subscription   (Followers: 145)
Economic Affairs     Hybrid Journal   (Followers: 6)
Economic and Industrial Democracy     Hybrid Journal   (Followers: 8)
Economic Bulletin     Hybrid Journal   (Followers: 4)
Economic Policy     Hybrid Journal   (Followers: 59)
Economic Record     Hybrid Journal   (Followers: 6)
Emirates Journal of Food and Agriculture     Open Access   (Followers: 1)
Empirical Economics     Hybrid Journal   (Followers: 13)
Encuentro     Open Access  
Engineering in Agriculture, Environment and Food     Hybrid Journal  
Ensaios e Ciência: Ciências Biológicas, Agrárias e da Saúde     Open Access  
Eppo Bulletin     Hybrid Journal   (Followers: 2)
Ethiopian Journal of Agricultural Sciences     Open Access  
Ethiopian Journal of Science and Technology     Open Access  
Ethology     Hybrid Journal   (Followers: 5)
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: 10)
European Journal of American Culture     Hybrid Journal   (Followers: 2)
European Journal of Health Economics     Hybrid Journal   (Followers: 19)
European Journal of Law and Economics     Hybrid Journal   (Followers: 62)
European Review of Agricultural Economics     Hybrid Journal   (Followers: 12)
EvoDevo     Open Access   (Followers: 3)
Extensão Rural     Open Access   (Followers: 1)
Farmer’s Weekly     Full-text available via subscription  
Farmlink Africa     Full-text available via subscription  
Fitosanidad     Open Access  
Florea : Jurnal Biologi dan Pembelajarannya     Open Access  
Folia Horticulturae     Open Access   (Followers: 3)
Food and Agricultural Immunology     Hybrid Journal   (Followers: 2)
Food and Energy Security     Open Access   (Followers: 4)
Food Biotechnology     Hybrid Journal   (Followers: 12)
Food Economics - Acta Agriculturae Scandinavica, Section C     Hybrid Journal   (Followers: 2)
Food New Zealand     Full-text available via subscription   (Followers: 4)
Food Policy     Hybrid Journal   (Followers: 31)
Forest@ : Journal of Silviculture and Forest Ecology     Open Access  
Forestry Chronicle     Full-text available via subscription   (Followers: 10)
Forum for Health Economics & Policy     Hybrid Journal   (Followers: 7)

        1 2 3 | Last

Journal Cover Biosystems Engineering
  [SJR: 0.824]   [H-I: 77]   [8 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1537-5110 - ISSN (Online) 1537-5129
   Published by Elsevier Homepage  [3043 journals]
  • Measurement and modelling of soil displacement from sweeps with different
           cutting widths
    • Authors: Songül Gürsoy; Ying Chen; Bo Li
      Pages: 1 - 13
      Abstract: Publication date: September 2017
      Source:Biosystems Engineering, Volume 161
      Author(s): Songül Gürsoy, Ying Chen, Bo Li
      Soil dynamic properties are important performance indicators for soil-engaging tools. In this study, soil displacement and cutting forces of selected sweeps were measured and simulated. The sweeps had different cutting widths: 153, 280, and 330 mm, and they were tested in an indoor soil bin with a sandy loam soil at a working depth of 50 mm and a travel speed of 1.53 m s−1. A discrete element model was developed using PFC3D (Particle Flow Code in Three Dimensions) to simulate soil-sweep interactions. With the measured soil cutting forces, the model particle stiffness was calibrated to be 3 × 103 N m−1. Results from modelling and measurements showed a general trend of the highest displacements around the centre of the path of sweep, reducing at the further distance away from the centre. Among all directions, measured soil displacements were the highest in the forward direction, up to 608 mm. Measured results showed that forward soil displacements were smaller for smaller sweeps, and lateral soil displacements were lower at a greater depth regardless of the sweeps. Simulated forward and lateral displacements did not contradict these results. Among all the sweeps, the 153-mm wide sweep had significantly higher vertical displacements at all depths as compared to the other sweeps, demonstrated by both measurements and simulations. Overall, the simulated soil displacements were lower than the measured values in all three directions. The accuracy of the model needs to be improved for predictions of soil displacements.

      PubDate: 2017-07-09T08:07:08Z
      DOI: 10.1016/j.biosystemseng.2017.06.005
      Issue No: Vol. 161 (2017)
       
  • Models to predict the thermal state of rice stored in aerated vertical
           silos
    • Authors: Oleg A. Khatchatourian; Manuel O. Binelo; Ricardo Neutzling; Vanessa Faoro
      Pages: 14 - 23
      Abstract: Publication date: September 2017
      Source:Biosystems Engineering, Volume 161
      Author(s): Oleg A. Khatchatourian, Manuel O. Binelo, Ricardo Neutzling, Vanessa Faoro
      The thermal state of the rice mass in steel vertical silo with an aeration system, located in a rice storage facility in Rio Grande do Sul State, Brazil, was studied. Data obtained by thermometry system were compared with the predicted data obtained from four one-dimensional models. The first model was based on the hypothetical division of the deep bed into a limited number of thin layers with identical temperatures of the grain and the passing air. The second model presented the system of two partial differential equations, describing the heat transfer and conservation of energy for air and for grain mass. The third model used the generalised dependence between dimensionless temperature and homochronous number and was adapted to conditions when both a variable temperature of the ventilation air inlet and an initial non-uniformity of the grain mass temperature existed. The fourth model was intermediate between the thermal state problem of a body made up of two different materials (with fixed boundary) and the Stefan problem in which a moving boundary separates the different phase domains. The velocity of the moving boundary and thermal diffusivities of each domain were obtained experimentally. Each of the proposed models satisfactorily described the thermal state of the studied silo. The use of the last data reading obtained as a new initial condition increased simulation accuracy. In the case of a significant transverse temperature inhomogeneity, a hypothetical division of the silo into independent vertical cylinders centred on the respective thermometry cables increased accuracy.

      PubDate: 2017-07-09T08:07:08Z
      DOI: 10.1016/j.biosystemseng.2017.06.013
      Issue No: Vol. 161 (2017)
       
  • Evaluation of the performance of portable visible-infrared instruments for
           the prediction of soil properties
    • Authors: José M. Soriano-Disla; Leslie J. Janik; Danielle J. Allen; Michael J. McLaughlin
      Pages: 24 - 36
      Abstract: Publication date: September 2017
      Source:Biosystems Engineering, Volume 161
      Author(s): José M. Soriano-Disla, Leslie J. Janik, Danielle J. Allen, Michael J. McLaughlin
      Good soil management requires large amounts of soil data which are expensive to provide using traditional laboratory methods. Soil infrared spectroscopy including portable/miniaturized visible-infrared spectrometers offers a cost-effective solution. There is a need to test and compare the performance of portable/miniaturized mid-infrared (MIR) and visible-near-infrared (vis-NIR) spectrometers for the prediction of soil properties across a range of soils. For this assessment, 458 soil samples from Australia were scanned by four vis-NIR and MIR portable/miniature spectrometers and partial least squares regressions (PLSR) applied for the prediction of 17 properties in soils dried at 40 °C and sieved to <2 mm. The performance of these instruments was tested and compared to a reference benchtop MIR/NIR instrument. Mid-infrared handheld instruments provided the best performance, the vis-NIR instrument the next most successful, and the miniature NIR instrument with a restricted spectral range (950–1650 nm) being less successful. When models using the same spectral range obtained by different instruments were compared, similar performance was achieved, thus the spectral quality provided by different instrumentation was not decisive in determining prediction accuracy. Many new portable infrared instruments have restricted spectral ranges, thus a number of different spectral ranges in both the MIR and vis-NIR were assessed to determine the optimal range for prediction of soil properties. It was concluded that the range 1650–5000 nm would be ideal.

      PubDate: 2017-07-09T08:07:08Z
      DOI: 10.1016/j.biosystemseng.2017.06.017
      Issue No: Vol. 161 (2017)
       
  • Reliability of turbulence models and mesh types for CFD simulations of a
           mechanically ventilated pig house containing animals
    • Authors: Hao Li; Li Rong; Guoqiang Zhang
      Pages: 37 - 52
      Abstract: Publication date: September 2017
      Source:Biosystems Engineering, Volume 161
      Author(s): Hao Li, Li Rong, Guoqiang Zhang
      The use of computational fluid dynamics (CFD) to study the airflow within farm animal buildings is increasing. The choice of turbulence model within CFD is generally considered to be important due to the approximations of the turbulence in varied scales. Although some studies have been conducted on evaluations of turbulence models in simulation of airflow in ventilated rooms, knowledge of airflow in the animal occupied zone (AOZ) with airflow blockage by the animals and knowledge of thermal convection effects are still limited. In this study, five commonly used two-equation turbulence models (standard k–ɛ, realisable k–ɛ, RNG k–ɛ, standard k–ω, and SST k–ω) were applied to a CFD model of the airflow in a mechanically ventilated pig room with animals housed in pens. In addition to turbulence models, the effects of non-conformal meshing which combines several computational sub-domains and connects the boundary of domains using interfaces, were tested. The effect of mesh ratio on the interface (i.e. ratio of the grid number of the up and down interface) was studied based on fully structural hexahedral mesh (SH). The investigation of mesh type effect was conducted by application of an unstructured tetrahedral mesh (UT) in the AOZ and SH in the rest of the domain. The results showed that the choice of turbulence model did not have a strong effect on the main airflow pattern except for the RNG k–ɛ model. The tested ratios of resolution at interfaces were also found not to strongly impact on the predicted airflow distributions. The use of UT in the AOZ sub domain also provided acceptable results. It was concluded that non-conformal meshes are a feasible alternative for animal buildings with complex geometries to maintain affordable grid numbers and also reduce the difficulties in mesh generation.

      PubDate: 2017-07-09T08:07:08Z
      DOI: 10.1016/j.biosystemseng.2017.06.012
      Issue No: Vol. 161 (2017)
       
  • Comparing environmental impact of air scrubbers for ammonia abatement at
           pig houses: A life cycle assessment
    • Authors: Jerke W. De Vries; Roland W. Melse
      Pages: 53 - 61
      Abstract: Publication date: September 2017
      Source:Biosystems Engineering, Volume 161
      Author(s): Jerke W. De Vries, Roland W. Melse
      Intensive livestock production involves environmental emissions and impacts, including emission of greenhouse gases and ammonia leading to climate change and terrestrial acidification. Ammonia emission from animal housing systems can be reduced by introducing air scrubbers for cleaning the exhaust air, but insight into the environmental impact throughout the entire system is lacking. This study aimed to assess and compare the environmental impact of three types of air scrubbers: an acid scrubber and two biotrickling filters, one with nitrification only and one with nitrification and denitrification. Air scrubbers were compared by using life cycle assessment and assessing five environmental impacts: climate change, terrestrial acidification, marine eutrophication, particulate matter formation and fossil fuel depletion. The acid scrubber showed reductions in all environmental impact categories (up to >2000%), whereas the biotrickling filter with combined nitrification and denitrification had highest climate change and fossil fuel depletion. The biotrickling filter with nitrification only had highest terrestrial acidification and marine eutrophication.

      PubDate: 2017-07-09T08:07:08Z
      DOI: 10.1016/j.biosystemseng.2017.06.010
      Issue No: Vol. 161 (2017)
       
  • Characterisation of the viscoelastic properties of avocado puree for
           process design applications
    • Authors: Laura Patricia Martínez-Padilla; Lisa Franke; Pablo Juliano
      Pages: 62 - 69
      Abstract: Publication date: September 2017
      Source:Biosystems Engineering, Volume 161
      Author(s): Laura Patricia Martínez-Padilla, Lisa Franke, Pablo Juliano
      Avocado is increasingly utilised for the manufacture of products including purees, concentrates, powders and avocado oil. The design of such processes requires understanding of the rheology, particularly during the puree's transformation. This study characterised the viscoelastic properties at 25 °C of fresh avocado puree resulting from various processing operations including mixing, water dilution, and after sonication treatment. The storage (G′) and loss (G″) moduli of avocado puree demonstrated a solid-like behaviour irrespective of treatment or dilution, contrary to other food matrices. Avocado puree produced with manual-shearing showed greater G′ and G″ than when obtained with a food-processor. Extended shearing through the malaxation operation (mixing and kneading at 49 rpm and 45 °C); or water dilution to 72–94% moisture, diminished both moduli, with an exponential decrease observed in the latter. However, sonication for 5 min with high-power-ultrasound (18 kHz and 40 kHz) or megasonics (MS) (2 MHz) (80–90 kJ kg−1) increased G′ and G″. The net change in viscoelastic properties due to puree low frequency sonication correlated linearly with moisture content. The influence of processing interventions in avocado puree was demonstrated through rheological methods applicable for avocado process optimisation and product development.
      Graphical abstract image

      PubDate: 2017-07-09T08:07:08Z
      DOI: 10.1016/j.biosystemseng.2017.06.016
      Issue No: Vol. 161 (2017)
       
  • Improving the repeatability of dynamic olfactometry according to EN 13725:
           A case study for pig odour
    • Authors: Nathalie C.Y. Hove; Peter Demeyer; Caroline Van der Heyden; Stephanie Van Weyenberg; Herman Van Langenhove
      Pages: 70 - 79
      Abstract: Publication date: September 2017
      Source:Biosystems Engineering, Volume 161
      Author(s): Nathalie C.Y. Hove, Peter Demeyer, Caroline Van der Heyden, Stephanie Van Weyenberg, Herman Van Langenhove
      Dynamic olfactometry, according to the standard EN 13725:2003 (CEN, 2003), is the reference method in Europe to measure odour concentrations and emissions from agricultural and industrial facilities. Laboratory measures to improve the precision (repeatability) of olfactometry were investigated here, focussing on the reference odorant, n-butanol and on pig house odour as an environmental odour. The effects of panel size, of the panellists' performance level, of the odour type and of the number of rounds on the olfactometric precision were studied. A precision-analysis tool was developed in Matlab, which randomly constituted 20,250 odour panels and randomly selected odour thresholds to generate 40,500 odour concentrations, calculated according to EN 13725. These simulations were performed, using 10 datasets of in total 776 olfactometric thresholds, measured by CEN-qualified panellists. The first results (reference odorant only) indicated that the panellists' performance level, the panel size and the number of rounds all significantly affected the laboratory's repeatability and that increasing the panel size, improved the repeatability the most. In a second study, comparing n-butanol and pig odour, as well odour type, as panel size, as the number of rounds significantly influenced the laboratory's repeatability. Odour type had the highest influence, followed by an increasing panel size. Based on these two studies, increasing the panel size seems a good means for improving the repeatability. For pig odour specifically, increasing the number of rounds from 2 to 3, improved the repeatability as much as one extra panellist.

      PubDate: 2017-07-09T08:07:08Z
      DOI: 10.1016/j.biosystemseng.2017.06.004
      Issue No: Vol. 161 (2017)
       
  • Pyrolysis in auger reactors for biochar and bio-oil production: A review
    • Authors: Patrick Brassard; Stéphane Godbout; Vijaya Raghavan
      Pages: 80 - 92
      Abstract: Publication date: September 2017
      Source:Biosystems Engineering, Volume 161
      Author(s): Patrick Brassard, Stéphane Godbout, Vijaya Raghavan
      Pyrolysis is the thermochemical decomposition of biomass under oxygen-limiting conditions used for biochar and bio-oil production. Depending on biomass feedstock, pyrolysis technology and operating parameters, product yields and properties will differ. Among the available pyrolysis units, auger pyrolysis is a polyvalent and promising technology for producing both bio-oil and biochar. These reactors are simple to operate and can be mobile, they require little or no carrier gas and low energy. Moreover, the operating parameters can be controlled easily in order to obtain the desired products. Recently, many research articles on biomass pyrolysis in auger reactors have been published. Design of laboratory-scale pyrolysis units and operating parameters differ considerably. Therefore, there was a need to list the studies in which auger pyrolysis reactors are used and to collect data for experimental operating parameters and product yields. The type and the capacity of the reactor, pyrolysis temperature, solid residence time, carrier gas flowrate, vapour residence time, and biomass feedstock type and size were identified as the parameters having the most influence on product yields and their properties. Because each pyrolysis reactor is unique, it is important to establish the relationship between operating parameters and product yields and their properties for each biomass feedstock. Future work is needed in order to provide simple solutions to scale-up laboratory-scale auger pyrolysis units to industrial size.

      PubDate: 2017-07-09T08:07:08Z
      DOI: 10.1016/j.biosystemseng.2017.06.020
      Issue No: Vol. 161 (2017)
       
  • Nitrogen-oxide emissions from diesel-engine farm tractors during real-life
           cycles and their correlation with the not-to-exceed operating zones
    • Authors: Algirdas Janulevičius; Antanas Juostas; Aušra Čiplienė
      Pages: 93 - 105
      Abstract: Publication date: September 2017
      Source:Biosystems Engineering, Volume 161
      Author(s): Algirdas Janulevičius, Antanas Juostas, Aušra Čiplienė
      A methodology is introduced to help provide a better understanding of how real-life factors influence emissions from tractors by determining: engine speed vs. load for modes in which tractors most often operate in farms; the operating time for tractor engines in load vs. speed modes that fall into the range of exhaust gas not-to-exceed (NTE) control zones; NOx emissions during tractor real-life cycles, and the quantities emitted by engines when operating in NTE zone. Real-life operating times were calculated and broken down by engine operating modes and NOx emissions by referring to load profile databases accumulated in the control processors of tractor engines. Tests showed that for the ten farm tractors studied (Massey Ferguson 6499), they operated with engine operating modes that fell into the NTE zone for only about 51% of their total real-life operating times and in that mode emitted 60.1% of the total NOx gases emitted during the whole of their operation. Most of the tractors (∼76%) emitted NOx during engine loads above 50% of the maximum torque (T max ), 21.6% at loads between 30 and 50% of T max , and only 2.3% in loads up to 30% of the T max . The most significant amount of NOx emitted during the real-life cycles occurred when the tested engines operated in a cyclic fuel injection mode with 10–20 mg cycle−1 and engine speeds of 700–1100 rpm. The data acquired using this method could help farmers operate tractors in a more rational and environmental modes.

      PubDate: 2017-07-09T08:07:08Z
      DOI: 10.1016/j.biosystemseng.2017.06.022
      Issue No: Vol. 161 (2017)
       
  • Influence of the divider head functioning conditions and geometry on the
           seed's distribution accuracy of the air-seeder
    • Authors: Andrii Yatskul; Jean-Pierre Lemiere; Frédéric Cointault
      Pages: 120 - 134
      Abstract: Publication date: September 2017
      Source:Biosystems Engineering, Volume 161
      Author(s): Andrii Yatskul, Jean-Pierre Lemiere, Frédéric Cointault
      As the working width of sowing implements increases, the use of conventional mechanical seed drills, with hoppers above all the implement working width, has reached its limits. Any further increase of the working width (more than 4–6 m) or the coupling of conventional additional apparatus is expensive, complex and time-consuming. Air-seeding appears thus as the best solution to solve this problem. One storage hopper is able to supply the working width of 24 m or more. However, it should be noticed that to ensure uniform crop growing, a machine needs an accurate, technical solution to ensure seeding material to be distributed across the full implement working width. Indeed, low transversal distribution accuracy is one of the most important shortcomings of modern air-seeders. Even if air-seeding has been used for more than 50 years, few developments have been carried out on divider headers responsible for distribution accuracy. This paper deals with a study on the influence of divider head geometry and functioning conditions on the seed's distribution accuracy. The first part concerns the study of the influence of the air velocity and the material flow rate on the distribution accuracy. A second study deals with the influence of the outlet closing, of different outlet pipes lengths, of distribution head tightness, of the angle position of distribution heads. Finally the influence of the structural elements such as the pipe elbow, the tower configurations, the tower height and the cone shape deflectors' implementation on the divider lid is proposed. Moreover, observation of the seed's behaviour is undertaken using a high-speed camera system. These experimental results allowed for proposals of hypothesis about the parameters influencing the final result. This paper also proposes theoretical and mathematical explanations of the observed effects, necessary for future divider heads design.
      Graphical abstract image

      PubDate: 2017-07-23T07:53:23Z
      DOI: 10.1016/j.biosystemseng.2017.06.015
      Issue No: Vol. 161 (2017)
       
  • Validation of CFD models for the deep-bed drying of rice using thermal
           imaging
    • Authors: Ramadan A. ElGamal; Sameh S. Kishk; Gamal M. ElMasry
      Pages: 135 - 144
      Abstract: Publication date: September 2017
      Source:Biosystems Engineering, Volume 161
      Author(s): Ramadan A. ElGamal, Sameh S. Kishk, Gamal M. ElMasry
      Validation is one of the most important steps in modelling the drying process of cereal crops. Once a simulation model is validated, it can be used for further practical applications. This study examines the potential of the thermal imaging technique to validate computational fluid dynamic (CFD) simulation models developed for describing the deep-bed drying process of rough rice and to visualise the temperature profiles throughout the bed under different drying conditions. A laboratory forced-air convective dryer was designed and fabricated to dry the rough rice in deep layers and thermal images of the rough rice inside the drying bin were directly acquired during drying process. The predicted data of the CFD models for moisture and temperature distributions through the deep bed during drying were verified against the experimental results. The results revealed that the CFD model developed for predicting moisture content exhibited good correlation with a coefficient of determination R 2 = 0.96. The model was also very accurate for predicting the temperature of rough rice in the deep-bed dryer with coefficients of determination > 0.90 and low RMSE (<5 °C). A fair agreement was also obtained between the temperature values recorded by the thermocouples and those exported from the thermal images with a coefficient of determination of 0.94.

      PubDate: 2017-07-23T07:53:23Z
      DOI: 10.1016/j.biosystemseng.2017.06.018
      Issue No: Vol. 161 (2017)
       
  • Finite element model updating of multi-span greenhouses based on ambient
           vibration measurements
    • Authors: Taehyu Ha; Jinwon Kim; Bong-Ho Cho; Dae-Jin Kim; Ji-Eun Jung; Seung-Hoon Shin; Hongjin Kim
      Pages: 145 - 156
      Abstract: Publication date: September 2017
      Source:Biosystems Engineering, Volume 161
      Author(s): Taehyu Ha, Jinwon Kim, Bong-Ho Cho, Dae-Jin Kim, Ji-Eun Jung, Seung-Hoon Shin, Hongjin Kim
      Plastic greenhouses are often designed with low levels of safety. As a result there has been an increasing number of structural failures due to abnormal climatic conditions such as heavy snow and strong winds. Standardised prototypes are often used to facilitate the design process, but these prototypes cannot withstand every extreme loading condition. To aid the accurate evaluation of the disaster resilience of plastic greenhouse structures, finite element (FE) analysis for specific load cases is essential in their design process. In plastic greenhouses, clamp connectors and swivel couplers are generally used to connect beams to columns and arched rafters to purlins, and columns are usually driven directly into the ground to support the entire structure. In the FE analysis, however, connections and supports are idealised as fully rigid or frictionless-pinned, which does not accurately reflect realistic conditions. In this study, ambient vibration tests were performed on two full-scale models to identify the dynamic properties of multi-span greenhouses. FE model updating was then carried out to determine the rigidity factors of connections and supports that yield the same dynamic properties as built structures. The results showed that the modelling of connections and supports causes significant changes in modal frequencies. They also showed that the connection modelling condition contributed more to the dynamic parameters of the multi-span greenhouses than the support modelling condition.

      PubDate: 2017-07-23T07:53:23Z
      DOI: 10.1016/j.biosystemseng.2017.06.019
      Issue No: Vol. 161 (2017)
       
  • Machine vision system for the automatic segmentation of plants under
           different lighting conditions
    • Authors: Sajad Sabzi; Yousef Abbaspour-Gilandeh; Hossein Javadikia
      Pages: 157 - 173
      Abstract: Publication date: September 2017
      Source:Biosystems Engineering, Volume 161
      Author(s): Sajad Sabzi, Yousef Abbaspour-Gilandeh, Hossein Javadikia
      Precision agriculture needs the use new technologies for identification. Using digital images and analysing their colour is one of the most useful methods for the segmentation of plants from their background and is a basic operation in all machine vision applications. A machine vision system is presented based on hybrid artificial neural network-harmony search (ANN-HS) classifiers for the segmentation of different plants in different growth stages, different conditions of the day and one controlled state and different imaging situations. This system works in two stages; the first stage is to specify photography state and the second stage is to apply an appropriate threshold. In total, 23,899 images were taken from eight different states during the day and one control state. Five features among 126 extracting features of five colour spaces RGB, CMY, HSI, HSV, YIQ and YCbCr for use in classification unit were selected using hybrid artificial neural network – differential evolution algorithm. Meta-heuristics and statistical classifiers were used for classification. The results showed that the accuracies of meta-heuristics method of the hybrid artificial neural network-harmony search and k-nearest neighbour statistical method were 99.69% and 94.06% respectively. In order to determine appropriate thresholds an improved YCbCr colour space was proposed. The results showed that among eight different states during day and one control state, the level of threshold for six states must be determined in third channel related to this colour space and the rest should be determined in HSV and YIQ colour spaces. The suggested machine vision system segments each image during 0.37 s. Finally, it can be claimed that this system is applicable in all machine vision systems related to fields and has high accuracy and speed.

      PubDate: 2017-08-02T12:54:13Z
      DOI: 10.1016/j.biosystemseng.2017.06.021
      Issue No: Vol. 161 (2017)
       
  • Day-to-night heat storage in greenhouses: 1 Optimisation for periodic
           weather
    • Authors: Ido Seginer; Gerrit van Straten; Peter J.M. van Beveren
      Pages: 174 - 187
      Abstract: Publication date: Available online 24 July 2017
      Source:Biosystems Engineering
      Author(s): Ido Seginer, Gerrit van Straten, Peter J.M. van Beveren
      Day-to-night heat storage using water tanks (buffers) is common practice in cold-climate greenhouses, where gas is burned during the day for carbon dioxide enrichment. In this study an optimal control approach is outlined for such a system, based on the idea that the virtual value (shadow price) of the stored heat, its ‘co-state’, could be used to guide the instantaneous control decisions. If this value is high, the system has an incentive to fill the heat storage (buffer), and vice versa if the co-state is low. The optimal co-state trajectory maximises the net income (performance criterion). To illustrate the method, a system description and a parameter-set roughly representative of tomato greenhouses in The Netherlands is used. The results, for daily-periodic weather, show: (1) The optimal co-state is constant (same value night and day), in contrast to the varying set-points and control fluxes. (2) The optimal solution is associated with minimum time on the storage bounds (minimum time of full or empty buffer). (3) The optimal virtual value (co-state) of stored heat is about the same as the actual cost of boiler heat during winter and about zero in summer. (4) The gain from installing a buffer is highest during spring and minimal in winter. (5) The intensive utilisation of the heat buffer in summer and its low utilisation in winter indicate that the justification of the heat storage practice, under the assumed conditions, is more the need for CO2 enrichment in summer than the need for heating in winter.

      PubDate: 2017-08-02T12:54:13Z
      DOI: 10.1016/j.biosystemseng.2017.06.024
      Issue No: Vol. 161 (2017)
       
  • Day-to-night heat storage in greenhouses: 2 Sub-optimal solution for
           realistic weather
    • Authors: Ido Seginer; Gerrit van Straten; Peter J.M. van Beveren
      Pages: 188 - 199
      Abstract: Publication date: Available online 24 July 2017
      Source:Biosystems Engineering
      Author(s): Ido Seginer, Gerrit van Straten, Peter J.M. van Beveren
      Day-to-night heat storage in water tanks (buffers) is common practice in cold-climate greenhouses, where gas is burned during the day for carbon dioxide enrichment. In Part 1 of this study, an optimal control approach was outlined for such a system, the basic idea being that the virtual value (shadow price) of the stored heat (its ‘co-state’) could be used to guide the instantaneous control decisions. The results for daily-periodic weather showed: (1) The optimal co-state is constant in time. (2) The optimal solution is associated with minimum time on the storage bounds (buffer empty or full). With these conclusions as guidelines, a semi-heuristic procedure of optimisation for realistic (i.e. not strictly periodic) weather is developed. The co-state remains constant while the storage trajectory is between the heat storage bounds. It is gradually increased while the buffer is empty, and decreased when the buffer is full, attempting to push the trajectory away from the bounds, thus minimising the time that the buffer is idle. The main outcomes are: (1) No information about the future is required. (2) The algorithm changes the co-state automatically, producing the correct annual variation (high in winter and low in summer). (3) The predictions of yield and heat requirement compare favourably with practice. (4) The gain in performance achievable with the suggested method is probably 75% or more of the true optimum. (5) The procedure can be used in the design stage to determine the optimal buffer size and the usefulness of other modifications of the system.

      PubDate: 2017-08-02T12:54:13Z
      DOI: 10.1016/j.biosystemseng.2017.06.023
      Issue No: Vol. 161 (2017)
       
  • Anaerobic co-digestion of cattle manure and meadow grass: Effect of serial
           configurations of continuous stirred tank reactors (CSTRs)
    • Authors: Lu Feng; Radziah Wahid; Alastair J. Ward; Henrik B. Møller
      Pages: 1 - 11
      Abstract: Publication date: August 2017
      Source:Biosystems Engineering, Volume 160
      Author(s): Lu Feng, Radziah Wahid, Alastair J. Ward, Henrik B. Møller
      In this study, anaerobic co-digestion of cattle manure (CM) and meadow grass (MG) with serial configurations of continuous stirred tank reactors (CSTRs) was investigated. Four laboratory-scale CSTRs were operated at thermophilic condition (55 °C), of which two CSTRs were connected serially with equal working volumes while the remaining two CSTRs were operated as single CSTRs as controls. Improvements on bio-methane yield, methane contents and solids reduction were observed with serial CSTR configurations. The results showed that co-digestion with 5% (w/w) MG with serial configurations of CSTRs produced 24% more bio-methane compared with single reactor, with the total hydraulic retention time (HRT) being the same. The volatile fatty acids (VFA) concentration was found higher in the 1st reactor, but was reduced by 40–50% in the 2nd reactor. The improved bio-methane yield with serial CSTR configuration with 100% CM was 8%, indicating that the serial CSTRs process is superior in a co-digestion set up with addition of MG.

      PubDate: 2017-06-06T10:24:29Z
      DOI: 10.1016/j.biosystemseng.2017.05.002
      Issue No: Vol. 160 (2017)
       
  • Modelling and experimental verification of the thermal performance of an
           active solar heat storage-release system in a Chinese solar greenhouse
    • Authors: Wei Lu; Yi Zhang; Hui Fang; Xinglin Ke; Qichang Yang
      Pages: 12 - 24
      Abstract: Publication date: August 2017
      Source:Biosystems Engineering, Volume 160
      Author(s): Wei Lu, Yi Zhang, Hui Fang, Xinglin Ke, Qichang Yang
      An active solar heat storage-release (AHS) system that stores solar energy in a water storage tank can supplement heat to raise the air temperature in Chinese solar greenhouses (CSGs) during cold winter nights. To quantify such heat transfer processes and to improve the performance of AHS systems, a tank temperature model was developed. The model was calibrated and validated, and it can predict water temperatures in the storage tank with an average accuracy of 0.4 °C. The model was used to determine the required solar collector area and storage tank volume under various desired air temperatures in different greenhouses. In two cases, greenhouses with a ground area of 272 m2 and roughly 62 m2 of solar collectors were installed to maintain temperatures above 12 °C under Beijing climate conditions. To facilitate a 1 °C increase in the air temperature set-point, approximately 2 m2 of additional solar collectors and 0.1 m3 of additional storage tanks are needed.

      PubDate: 2017-06-11T10:30:23Z
      DOI: 10.1016/j.biosystemseng.2017.05.006
      Issue No: Vol. 160 (2017)
       
  • Composting potential of the solid fraction of digested pulp produced by a
           biogas plant
    • Authors: W. Czekała; J. Dach; R. Dong; D. Janczak; K. Malińska; K. Jóźwiakowski; A. Smurzyńska; M. Cieślik
      Pages: 25 - 29
      Abstract: Publication date: August 2017
      Source:Biosystems Engineering, Volume 160
      Author(s): W. Czekała, J. Dach, R. Dong, D. Janczak, K. Malińska, K. Jóźwiakowski, A. Smurzyńska, M. Cieślik
      Agricultural biogas plants produce biogas and residues referred to as digested pulp. In Europe, digestate is mostly used as fertilizer for agricultural soils although it can be converted to solid fertilizer and also used for biofuel production. The aim of this study was to evaluate if solid fraction of the digestate (DSF) is a suitable material for composting. Composting of DSF was performed for 51 d in a specially designed and constructed system of composting bioreactors (each with volume of 165 l). The process was controlled by daily measurements of temperature and gaseous emissions and samples of composted material tested for dry and organic matter, pH and conductivity. The maximum temperature of the composted mixture was 70.2 °C. High temperature (over 60 °C) for at least two days will allow to annihilate most pathogens. Dynamic temperature rise was related to significant decrease in organic matter (by 39.6%) – from an initial 8.46 kg to 5.12 kg at the end of the process. Decomposition of organic matter during the thermophilic phase of composting was also related to intensive emissions of CO2. The maximum values of carbon dioxide occurred at the highest compost temperature on the third day of the experiment and amounted to 13.3% in the chamber. The results of the analysed parameters allowed us to conclude that the composting process was operating properly and that composting of DSF can a solution for the management of biogas effluent.

      PubDate: 2017-06-11T10:30:23Z
      DOI: 10.1016/j.biosystemseng.2017.05.003
      Issue No: Vol. 160 (2017)
       
  • Histogram-based automatic thresholding for bruise detection of apples by
           structured-illumination reflectance imaging
    • Authors: Yuzhen Lu; Renfu Lu
      Pages: 30 - 41
      Abstract: Publication date: August 2017
      Source:Biosystems Engineering, Volume 160
      Author(s): Yuzhen Lu, Renfu Lu
      Thresholding is an important step in the segmentation of image features, and the existing methods are not all effective when the image histogram exhibits a unimodal pattern, which is common in defect detection of fruit. This study was aimed at developing a general automatic thresholding methodology for fast and effective segmentation of bruises from the images acquired by structured-illumination reflectance imaging (SIRI). SIRI images, under sinusoidal patterns of illumination at a spatial frequency of 100 cycles m−1, were acquired from 120 apple samples of four varieties with artificially created bruises and from another 40 apples with naturally occurred bruises. Subsequently, three sets of images, i.e., amplitude component (AC), direct component (DC) and ratio (i.e., dividing AC by DC), were derived from the original SIRI images. A unimodal thresholding method, called UNIMODE, was first applied to DC images for background removal, and then nine automatic thresholding techniques, including one unimodal and eight bimodal, were applied to the ratio images for bruise segmentation. It was found that severe over-segmentation occurred when using the bimodal thresholding methods, and this problem was mitigated by confining threshold selection to the lower part of the histogram that contained bruise information. Three bimodal thresholding techniques, i.e., INTERMODE (histogram valley emphasized), RIDLER (iterative thresholding), OTSU (clustering based) achieved the best bruise detection results with the overall accuracies of more than 90%. The overall detection results were further improved by integrating these techniques with the unimodal thresholding, due to reductions in the false positive error. The three bimodal thresholding techniques resulted in overall detection accuracies of 77–85% for naturally occurred bruises. This study has showed that the proposed automatic thresholding methodology provides a simple and effective tool for bruise detection of apples.

      PubDate: 2017-06-15T10:39:45Z
      DOI: 10.1016/j.biosystemseng.2017.05.005
      Issue No: Vol. 160 (2017)
       
  • Benefits of dry comminution of biomass pellets in a knife mill
    • Authors: Orla Williams; Edward Lester; Sam Kingman; Donald Giddings; Stephen Lormor; Carol Eastwick
      Pages: 42 - 54
      Abstract: Publication date: August 2017
      Source:Biosystems Engineering, Volume 160
      Author(s): Orla Williams, Edward Lester, Sam Kingman, Donald Giddings, Stephen Lormor, Carol Eastwick
      The potential benefits of dry comminution in a knife mill for a diverse range of biomass pellets are explored. The impact of dry comminution on energy consumption, particle size and shape, is examined as well as the link between milling and mechanical durability. Biomass pellet comminution energy was significantly lower (19.3–32.5 kW h t−1 [fresh] and 17.8–23.2 kW h t−1 [dry]) than values reported in literature for non-densified biomass in similar knife mills. The impact of drying was found to vary by feedstock. Dry grinding reduced milling energy by 38% for mixed wood pellets, but only 2% for steam exploded pellets. Particle size and shape, particle distribution dispersion, and distribution shape parameters changes between fresh and dry milling were also material dependent. Von Rittinger analysis showed that to maximise mill throughput, pellets should be composed of particles which can pass through the screen and thus have a neutral size change. A strong correlation was found between pellet durability and energy consumption for fresh biomass pellets. Dry grinding has the potential to significantly reduce energy consumption without compromising the product particle size, as well as enhancing product quality and optimising biomass pellet comminution and combustion.

      PubDate: 2017-06-15T10:39:45Z
      DOI: 10.1016/j.biosystemseng.2017.05.011
      Issue No: Vol. 160 (2017)
       
  • Measurement and numerical simulation of single-sided mechanical
           ventilation in broiler houses
    • Authors: Eliseo Bustamante; Salvador Calvet; Fernando Estellés; Antonio G. Torres; Antonio Hospitaler
      Pages: 55 - 68
      Abstract: Publication date: August 2017
      Source:Biosystems Engineering, Volume 160
      Author(s): Eliseo Bustamante, Salvador Calvet, Fernando Estellés, Antonio G. Torres, Antonio Hospitaler
      In recent years, some broiler production farms especially in Mediterranean areas, have incorporated single-sided mechanical ventilation (i.e. air inlets and fans are located in the same lateral wall). However, little scientific information on the performance of mechanical single-sided ventilation systems is available to date. This ventilation method is fitted to broiler houses because this ventilation system appears appropriate to diminish the stress and mortality of broilers during hot seasons in this climate. To analyse the single-sided ventilation method scientifically, the indoor environments of broiler houses were examined by numerical simulation using computational fluid dynamics (CFD) with validation using a range of different buildings with direct measurements using a multi-sensor system. An analysis of variation of the results of the validation tests produced to a p-value of 0.3908. Thus, the methodology employed (i.e. CFD or sensors) was not significant. The CFD simulations showed a wide range of values for air velocity: the minimum value of air velocity at broiler level was 0.52 ± 0.40 m s−1 and the maximum was 1.29 ± 0.41 m s−1. Two major conclusions were drawn in terms indoor air velocity: (i) excessive heterogeneity in the plane where the animals were located; and (ii) insufficient air movement to contribute to the thermoregulation of the birds and lower their internal heat and associated thermal stress in occasional periods of hot weather.

      PubDate: 2017-06-15T10:39:45Z
      DOI: 10.1016/j.biosystemseng.2017.05.009
      Issue No: Vol. 160 (2017)
       
  • Comparison of different uni- and multi-variate techniques for monitoring
           leaf water status as an indicator of water-deficit stress in wheat through
           spectroscopy
    • Authors: Bappa Das; Rabi N. Sahoo; Sourabh Pargal; Gopal Krishna; Rakesh Verma; Viswanathan Chinnusamy; Vinay K. Sehgal; Vinod K. Gupta
      Pages: 69 - 83
      Abstract: Publication date: August 2017
      Source:Biosystems Engineering, Volume 160
      Author(s): Bappa Das, Rabi N. Sahoo, Sourabh Pargal, Gopal Krishna, Rakesh Verma, Viswanathan Chinnusamy, Vinay K. Sehgal, Vinod K. Gupta
      Ten different wheat genotypes were studied for understanding their differential behaviour to different water-deficit stress levels. Hyperspectral data (350–2500 nm) and relative water content (RWC) of plants were measured at different stress level for identifying optimal spectral bands, indices and multivariate models to develop non-invasive phenotyping protocols. Evaluation of water sensitive existing spectral indices, proposed indices and band depth analysis at selected wavelengths was done with respect to RWC and prediction models were developed. The prediction models developed were efficient in predicting RWC with the R 2 values ranging from 0.73 to 0.88 for spectral indices and 0.74–0.85 with continuum depth. Then, the ratio spectral indices (RSI) and normalised difference spectral indices (NDSI) were obtained in all possible combinations within 350–2500 nm and their correlations with RWC were quantified to identify the best indices. The best spectral indices for estimating RWC in wheat were RSI (R 1391, R 1830) and NDSI (R 1391, R 1830) with R 2 of 0.86 and 0.81, respectively. Spectral reflectance data were also used to develop partial least squares regression (PLSR) followed by multiple linear regression (MLR), support vector machine regression (SVR), multivariate adaptive regression spline (MARS) and random forest (RF) model to calculate plant RWC. Among these multivariate models, PLSR was the best model for prediction of RWC (R 2 and RMSE of 0.96 and 3.88%; 0.91 and 6.52% for calibration and validation, respectively). The methodology developed would help for its further use in high-throughput phenomics of different crops for drought stress.

      PubDate: 2017-06-21T01:58:49Z
      DOI: 10.1016/j.biosystemseng.2017.05.007
      Issue No: Vol. 160 (2017)
       
  • Psychrometer based on a contactless infrared thermometer with a predictive
           model for water evaporation
    • Authors: Chien Lee; Yu-Jen Wang
      Pages: 84 - 94
      Abstract: Publication date: August 2017
      Source:Biosystems Engineering, Volume 160
      Author(s): Chien Lee, Yu-Jen Wang
      This study developed a novel psychrometer design in which air is pumped by a 0.35-W minifan through a chamber with a hanging wet wick and a single-packaged contactless infrared thermometer aimed at the wick. The thermometer is small sized, low cost, commercially available, and comes factory calibrated with a digital I2C communication port. It can measure the temperatures of the package itself (dry bulb) and the wick surface (wet bulb). For the fast conversions of relative humidity (RH) and vapour pressure deficit Δe from both dry- and wet-bulb temperatures in a low-end microcontroller, a method for deriving a fifth-order polynomial approximation equation for saturation vapour pressure e s is presented. This equation enables the calculation to be rapidly executed on the microcontroller. An error analysis of conversion conducted taking the Goff–Gratch equations as a standard indicates that at temperatures ranging from 0 °C to 55 °C, the computational accuracy for RH reading is within +0.02 to −0.005, compared with ±0.1 derived for the Magnus form; in addition, the accuracy for Δe is within +0.002 to −0.0013 hPa, compared with +0.23 to −0.024 hPa derived for the Magnus form. For predicting the water evaporation of the psychrometer according to its own climate parameters, a model based on the simplified Penman Equation was constructed; the predictive error for water mass loss is within ±2 g for a 325-g evaporation.

      PubDate: 2017-06-21T01:58:49Z
      DOI: 10.1016/j.biosystemseng.2017.05.010
      Issue No: Vol. 160 (2017)
       
  • Effects of landscape positions on soil resistance to rill erosion in a
           small catchment on the Loess Plateau
    • Authors: Ren Geng; Guang-hui Zhang; Qian-hong Ma; Hao Wang
      Pages: 95 - 108
      Abstract: Publication date: August 2017
      Source:Biosystems Engineering, Volume 160
      Author(s): Ren Geng, Guang-hui Zhang, Qian-hong Ma, Hao Wang
      Landscape position has significant effects on soil properties and plant roots, and thus probably affects soil resistance to rill erosion, reflected by rill erodibility and critical shear stress. However, the potential effects of landscape positions on soil resistance to rill erosion are still unclear. Therefore, this study was conducted to investigate the spatial variations in soil resistance to rill erosion under different landscape positions, and to identify the main factors controlling these variations in a small catchment of the Loess Plateau. 540 undisturbed soil samples were collected from 18 typical sampling sites of natural succession grassland under six landscape positions and subjected to scour under different flow shear stresses. The results showed that landscape position significantly affected the spatial variation of rill erodibility. The mean rill erodibility decreased gradually from the top of ridge to footslope and increased linearly with elevation. Significant differences were detected in rill erodibility between three grass species. No significant difference was found in critical shear stress between six landscape positions. Soil erosion and soil water content dominated the regular spatial changes of soil properties and root mass density along six landscape positions. All of these factors collectively resulted in the regular decrease of rill erodibility from the top of ridge to footslope. A negative relationship was identified between critical shear stress and clay content. Rill erodibility could be satisfactorily estimated by the median soil grain size, soil cohesion, water stable aggregate and root mass density.

      PubDate: 2017-06-21T01:58:49Z
      DOI: 10.1016/j.biosystemseng.2017.06.001
      Issue No: Vol. 160 (2017)
       
  • Bridging the gap between reliable data collection and the environmental
           impact for mechanised field operations
    • Authors: Daniela Lovarelli; Jacopo Bacenetti
      Pages: 109 - 123
      Abstract: Publication date: August 2017
      Source:Biosystems Engineering, Volume 160
      Author(s): Daniela Lovarelli, Jacopo Bacenetti
      Mechanisation is related to an important proportion of the environmental impacts associated with agriculture, mainly due to engine fuel consumption and exhaust gas emissions, and materials production, use and disposal. Despite standardised and extensively accepted methods for environmental impact assessment have been developed, their application to mechanical field operations is still limited. In absence of reliable data, the reductions in environmental impact that are achievable cannot be easily evaluated by studying machinery already available on the market and more suitable machinery or by selecting the proper coupling between the implement and the tractor. This study carries out a comparative Life cycle assessment (LCA) of a rotary harrowing operation using different data sources. Data was gathered from: (i) Ecoinvent database, (ii) ENVIAM, a tool developed to support the completion of inventories for agricultural machinery varying the local pedo-climatic, operating and mechanical features, and (iii) primary data directly collected during experimental tests with CAN-bus, GPS and exhaust gases analyser. The analysis showed that using database average data, the resulting environmental load is not always reliable and, in this particular study, it consistently overestimated most outcomes. Moreover, by processing primary data collected using modern technology, the operation could be split in different working phases (effective work, turns, stationary-idling). Thus, specific mechanical features were quantified and this permitted the environmental impact to be evaluated with more detail.

      PubDate: 2017-06-21T01:58:49Z
      DOI: 10.1016/j.biosystemseng.2017.06.002
      Issue No: Vol. 160 (2017)
       
  • Development of a cartridge design anaerobic digestion system for
           lignocellulosic biomass
    • Authors: Liangcheng Yang; David E. Kopsell; Alisha M. Kottke; Matthew Q. Johnson
      Pages: 134 - 139
      Abstract: Publication date: August 2017
      Source:Biosystems Engineering, Volume 160
      Author(s): Liangcheng Yang, David E. Kopsell, Alisha M. Kottke, Matthew Q. Johnson
      A novel cartridge design anaerobic digestion system was developed for the treatment of lignocellulosic biomass. This new design is composed of a novel anaerobic digestion chamber with three replaceable feedstock cartridges. This design has multiple advantages, e.g. high stability, easy to operate, and no liquid waste, over conventional anaerobic digestion systems. In a seven-month test, maize straw was employed as the feedstock, and the system was operated in three scenarios: no rotation of cartridge; rotation with 14 g dry maize straw in each cartridge; and rotation with 28 g dry maize straw in each cartridge. Results showed that biogas production from this system was comparable to solid-state anaerobic digestion units, and the rotation of cartridges significantly improved the stability of methane yield and reduced hydrogen sulfide in biogas. Digestion effluent was completely reused in the rotation tests.

      PubDate: 2017-06-29T02:05:35Z
      DOI: 10.1016/j.biosystemseng.2017.05.004
      Issue No: Vol. 160 (2017)
       
  • Automated calculation of udder depth and rear leg angle in
           Holstein-Friesian cows using a multi-Kinect cow scanning system
    • Authors: Jennifer Salau; Jan H. Haas; Wolfgang Junge; Georg Thaller
      Pages: 154 - 169
      Abstract: Publication date: August 2017
      Source:Biosystems Engineering, Volume 160
      Author(s): Jennifer Salau, Jan H. Haas, Wolfgang Junge, Georg Thaller
      Low cost off-the-shelf depth sensors Microsoft Kinect have already been used in studies related to body condition determination and lameness detection in dairy cows and the concept of a 3D cow scanning by combining the fields of view of six Kinect cameras being presented. The cow scanner was developed in an effort to remove if possible, the influence of human operators from conformation recording by gathering data on linear descriptive traits using image analysis. In this study, a 3D object recognition pipeline was presented to automatically determine udder and rear leg of cows recorded in free walking. These body parts were then used to calculate the height of the udder bottom above ground and the rear leg angle. Between the manually gathered corresponding conformation recording scores and the calculated traits, medium to high Spearman rank correlation coefficients (0.63 for udder bottom height, 0.67 for rear leg angle) were observed. Between consecutive measurements, the calculating of udder bottom height was highly repeatable (76.9%) and the rear leg angle showed medium repeatability (47.4%) due to variance induced by the phase of the step. Both traits exhibited expected behaviour as udder bottom heights significantly decreased with increasing lactation number and rear legs were significantly straighter in cows with greater sacrum height.

      PubDate: 2017-06-29T02:05:35Z
      DOI: 10.1016/j.biosystemseng.2017.06.006
      Issue No: Vol. 160 (2017)
       
  • Diurnal energy-partitioning and transpiration modelling in an insect-proof
           screenhouse with a tomato crop
    • Authors: Meir Teitel
      Pages: 170 - 178
      Abstract: Publication date: August 2017
      Source:Biosystems Engineering, Volume 160
      Author(s): Meir Teitel
      An experiment was conducted to measure diurnal energy partitioning and evaluate use of the Penman–Monteith equation to estimate diurnal crop transpiration in an insect-proof screenhouse. The experiment was conducted in a flat-roof house, 4 m in height with a floor area of 745 m2, which was ventilated only through a screened roof. Measurements included global solar radiation, air temperature and humidity outside and inside the screenhouse. Net radiation, soil heat flux, transpiration and air velocity were measured inside the house and wind speed and direction were measured outside. Results showed variation in transmittance of global solar radiation through the screen in the roof throughout the day. At noon, global and net radiation inside the house were about 0.68–0.73 and 0.44–0.45 of the outside global radiation, respectively. Above the canopy, the ratio of net radiation to global radiation varied throughout the day as well. Latent heat flux due to transpiration was about 0.7–0.8 of net radiation most of the day, and the proportion increased in the late afternoon to about 1.4. Sensible heat flux was about 0.06–0.25 of external global radiation until early afternoon and became negative in the late afternoon. Soil heat flux was less than 3% of the external global radiation. The Penman–Monteith equation predicted daily transpiration within 4–6%. A net cooling effect of the screenhouse air was defined and it is shown that the difference between internal and external air temperature correlated well with that cooling effect.

      PubDate: 2017-07-09T08:07:08Z
      DOI: 10.1016/j.biosystemseng.2017.05.008
      Issue No: Vol. 160 (2017)
       
  • Analysis of the parameters affecting the mechanical behaviour of straw
           bales under compression
    • Authors: Mirko Maraldi; Luisa Molari; Nicolò Regazzi; Giovanni Molari
      Pages: 179 - 193
      Abstract: Publication date: August 2017
      Source:Biosystems Engineering, Volume 160
      Author(s): Mirko Maraldi, Luisa Molari, Nicolò Regazzi, Giovanni Molari
      Straw bale construction is a building technique that has excellent thermal performance and limited impact on the environment. Improving knowledge of the mechanical properties of straw bales is important to understand the behaviour of straw bale buildings, especially in case of natural calamities, where straw bales may carry mechanical load and act as a “surviving cell”. The results of extensive tests conducted on bales of different materials are presented. The influence of the material, bale density, bale orientation, baling process and loading rate on the mechanical properties of straw bales was investigated. Force-displacement curves obtained from monotonic compression tests were analysed and relationships between the mechanical properties of straw bales and their geometry and density were determined. Continuous measurements of bales lateral displacement allowed Poisson's ratio to be calculated and, using a simple model, the strain to which bale strings are subjected during loading was estimated. Young's modulus was shown to mainly depend on the square of the density, while no influence of the loading rate and of strings pre-tension was observed. The Poisson's ratio did not remain constant during loading and it exhibited a different trend depending on the orientation of the bales. Moreover, it was observed that for flat bales a rearrangement of the straw fibres during loading occured and the maximum strings strain remained limited. Strings strain reached higher values for on-edge bales instead, and strings bursts occured more frequently.

      PubDate: 2017-07-09T08:07:08Z
      DOI: 10.1016/j.biosystemseng.2017.06.007
      Issue No: Vol. 160 (2017)
       
  • Impact forces on the drive spoon of a large cannon irrigation sprinkler:
           Simple theory, CFD numerical simulation and validation
    • Authors: Pan Tang; Hong Li; Zakaria Issaka; Chao Chen
      Pages: 1 - 9
      Abstract: Publication date: July 2017
      Source:Biosystems Engineering, Volume 159
      Author(s): Pan Tang, Hong Li, Zakaria Issaka, Chao Chen
      The service life and stability of the large cannon sprinklers depends on the stress distribution that occurs on the drive spoon caused by the impact force of the driving water jet. A simple theory of the forces caused by the impact of the water jet on the drive spoon was developed, and a three-dimensional (3D) model numerical simulation using computational fluid dynamics (CFD) was constructed. An experiment was carried out to verify the accuracy of the simple momentum-based theory and the numerical CFD simulations. The results showed a large deviation between the simulated and measured values under low pressure conditions, with a maximum deviation of 15.98%. However, the simulations had good accuracy under high pressure conditions. The difference between simple theory and experimental values also decreased with increasing working pressure when considering both horizontal and vertical components. The simple theory was adjusted by the use of correction factors that were regressed with working pressure using experimental data. The coefficient of determination of the correction factor expressions for both the horizontal and vertical components were 0.9799 and 0.9289 respectively. After adjustment of the simple theory, the calculated values of the vertical and horizontal impact forces were compared to the experimental values and had a difference <5%.

      PubDate: 2017-05-07T10:23:17Z
      DOI: 10.1016/j.biosystemseng.2017.04.005
      Issue No: Vol. 159 (2017)
       
  • Spatial assessment of soluble solid contents on apple slices using
           hyperspectral imaging
    • Authors: Changyeun Mo; Moon S. Kim; Giyoung Kim; Jongguk Lim; Stephen R. Delwiche; Kuanglin Chao; Hoonsoo Lee; Byoung-Kwan Cho
      Pages: 10 - 21
      Abstract: Publication date: July 2017
      Source:Biosystems Engineering, Volume 159
      Author(s): Changyeun Mo, Moon S. Kim, Giyoung Kim, Jongguk Lim, Stephen R. Delwiche, Kuanglin Chao, Hoonsoo Lee, Byoung-Kwan Cho
      A partial least squares regression (PLSR) model to map internal soluble solids content (SSC) of apples using visible/near-infrared (VNIR) hyperspectral imaging was developed. The reflectance spectra of sliced apples were extracted from hyperspectral absorbance images obtained in the 400–1000 nm range. Prediction models for SSC mapping were developed for three different measurement/sampling designs that varied in the number and size of the regions of interest (ROIs) used for apple SSC measurement and spectral averaging. Case 1 used 29 small ROIs per apple, Case II used 9 moderate-size ROIs per apple, and Case III used 5 large ROIs per apple. The optimal pre-treatment of the spectra extracted from the hyperspectral images was investigated to enhance the performance of the prediction models. The coefficients of determination and root mean square errors of the best-performing models were, respectively, 0.802 and ±0.674 °Brix for Case I, 0.871 and ±0.524 °Brix for Case II, and 0.876 and ±0.514 °Brix for Case III. The accuracy of the PLSR models was enhanced by using the spectra and SSC measured/averaged from the fewer but larger areas of the apples rather than from more numerous but smaller areas. PLS images of SSC showed the predicted internal distribution of SSC within the apples. The overall results demonstrate that hyperspectral absorbance imaging techniques may be useful for mapping internal soluble solids content of apples.

      PubDate: 2017-05-07T10:23:17Z
      DOI: 10.1016/j.biosystemseng.2017.03.015
      Issue No: Vol. 159 (2017)
       
  • Development of calibration models for the evaluation of pomegranate aril
           quality by Fourier-transform near infrared spectroscopy combined with
           chemometrics
    • Authors: Ebrahiema Arendse; Olaniyi A. Fawole; Lembe S. Magwaza; Helene H. Nieuwoudt; Umezuruike L. Opara
      Pages: 22 - 32
      Abstract: Publication date: July 2017
      Source:Biosystems Engineering, Volume 159
      Author(s): Ebrahiema Arendse, Olaniyi A. Fawole, Lembe S. Magwaza, Helene H. Nieuwoudt, Umezuruike L. Opara
      A Fourier transform NIR (FT-NIR) method was developed combining chemometrics for prediction of organoleptic and phytochemical parameters of pomegranate arils using two different FT-NIR acquisition methods; namely, an integrating sphere (IS) and an emission head (EH) used over a spectral region 800–2500 nm. Several pre-processing methods were investigated. Pre-processing methods that yielded higher coefficient of determination (R2) and residual predictive deviation (RPD), lower root mean square error estimation (RMSEE) and root mean square error of prediction (RMSEP) values were used for model development. Model development using the EH gave the best prediction of total soluble solids (R2 = 87.55, RMSEP = 0.30%), pH (R2 = 85.18, RMSEP = 0.10), titratable acidity (R2 = 85.59, RMSEP = 0.10%), BrimA (R2 = 83.43, RMSEP = 0.43), aril hue (R2 = 88.59, RMSEP = 4.19), total phenolic concentration (R2 = 86.48, RMSEP = 0.11 g l−1), total anthocyanin concentration (R2 = 70.50, RMSEP = 0.13 g l−1) and vitamin C concentration (R2 = 84.86, RMSEP = 0.09 g l−1), while the IS provided the best results for TSS:TA (R2 = 82.20, RMSEP = 1.03), aril firmness (R2 = 68.40, RMSEP = 6.71 N), aril colour components (a* (R2 = 73.54, RMSEP = 1.67) and Chroma (R2 = 78.37, RMSEP = 2.31)). Good prediction was observed for both the models based on EH and IS data acquisition methods. However, better prediction performance was obtained with the model based on EH data acquisition method, resulting in accurate predictions of 8 quality parameters. This study demonstrated that FT-NIR and associated chemometric analysis can holistically evaluate the quality parameters of pomegranate arils.

      PubDate: 2017-05-07T10:23:17Z
      DOI: 10.1016/j.biosystemseng.2017.04.004
      Issue No: Vol. 159 (2017)
       
  • Effect of process variables on ethylene removal by vacuum ultraviolet
           radiation: Application in fresh produce storage
    • Authors: Namrata Pathak; Oluwafemi J. Caleb; Cornelia Rauh; Pramod V. Mahajan
      Pages: 33 - 45
      Abstract: Publication date: July 2017
      Source:Biosystems Engineering, Volume 159
      Author(s): Namrata Pathak, Oluwafemi J. Caleb, Cornelia Rauh, Pramod V. Mahajan
      Detrimental effects of ethylene on fresh produce make ethylene removal one of the major challenges in storage of horticultural commodities. Novel techniques based on advanced oxidation processes such as photocatalysis and photolysis by vacuum ultraviolet light (VUV) offer good potential for ethylene removal. This study focused on the use of VUV photolysis and the impact of different process variables on the efficiency of this technique. The set objectives of this study were to investigate the combined effects of three process variables; flow rate, initial ethylene concentration, and ultraviolet radiation on the efficiency of VUV photolysis for removal of ethylene at normal atmospheric conditions. Response surface methodology along with Box–Behnken design was applied to determine the combined effect of these variables. Flowrate exerted the most significant effect on the amount of ethylene removed, followed by initial ethylene concentration and ultraviolet lamp power. The combined effect of these three process parameters exerted a significant effect on percentage ethylene removal. Reducing the flowrate and increasing the lamp power as well as the initial ethylene concentration had a positive effect on the amount of ethylene removed. For an initial ethylene concentration of 5 ppm, the percentage ethylene removal (76%) was highest under optimised process variable of 9 W lamp power and 0.5 L/min flowrate. The developed reactor was tested on short term storage of apples and kiwifruit. The reactor effectively reduced ethylene concentrations in storage space of both products. Kiwifruit storage connected to the reactor had higher flesh firmness compared to the control samples.

      PubDate: 2017-05-12T10:26:51Z
      DOI: 10.1016/j.biosystemseng.2017.04.008
      Issue No: Vol. 159 (2017)
       
  • Evaluation of the ripening stages of apple (Golden Delicious) by means of
           computer vision system
    • Authors: Stefany Cárdenas-Pérez; Jorge Chanona-Pérez; Juan V. Méndez-Méndez; Georgina Calderón-Domínguez; Rubén López-Santiago; María J. Perea-Flores; Israel Arzate-Vázquez
      Pages: 46 - 58
      Abstract: Publication date: July 2017
      Source:Biosystems Engineering, Volume 159
      Author(s): Stefany Cárdenas-Pérez, Jorge Chanona-Pérez, Juan V. Méndez-Méndez, Georgina Calderón-Domínguez, Rubén López-Santiago, María J. Perea-Flores, Israel Arzate-Vázquez
      Mexican apple production suffers high losses due to poor handling in processing. Implementation of a straightforward, low cost method to sort apples by their ripening stage is required. A set of Golden Delicious apples was used to monitor their physicochemical properties and external colour, a second set of apples was used to validate the method. To classify the stages, a ripening index (RPI) was proposed, in which three stages were identified; unripe, ripe and senescent. Weibull model was applied to the physicochemical parameters in order to describe their kinetic behaviour. The three RPI stages were compared with colour variability using the CIELab colour space, chroma (C ∗) and hue angle (h ∗), allowing the identification of the three ripening stages. Principal component analysis was used to evaluate the correlation between variables. A first correlation was performed between physicochemical and colour parameters and variables correlated correctly between each other except for L ∗, but both described the samples variability with 91.05% reliability. Using only colour parameters, the samples were described accurately with 95.06% reliability. Multivariate discriminant analysis (MDA) was done in order to validate the method. A cross-validation was performed with an initial set of apples used as trial samples and a second set of apples for validation. MDA was capable of classifying apples in their correct ripening stage with 100% accuracy. A second analysis was carried out using four colour parameters (a ∗, b ∗, C and h ∗), and results indicated that the ripening stages can be classified with 100% accuracy.

      PubDate: 2017-05-12T10:26:51Z
      DOI: 10.1016/j.biosystemseng.2017.04.009
      Issue No: Vol. 159 (2017)
       
  • Biofiltration of exhaust air from animal houses: Evaluation of removal
           efficiencies and practical experiences with biobeds at three field sites
    • Authors: Roland W. Melse; Johanna M.G. Hol
      Pages: 59 - 69
      Abstract: Publication date: July 2017
      Source:Biosystems Engineering, Volume 159
      Author(s): Roland W. Melse, Johanna M.G. Hol
      Three wood-chip based biofilters (‘biobeds’) with media depth of 0.25 m were monitored during 6–12 months (capacity and surface area for biofilter #1: 75,000 m3 h−1 from poultry manure dryer, 68 m2; biofilter #2: 100,000 m3 h−1 from pig house, 188 m2; biofilter #3: 300,000 m3 h−1 from pig house, 440 m2). Average empty bed residence times (EBRT) were 1.4, 2.6, and 3.3 s; average pressure drops were 287, 22, and 91 Pa, respectively. Average ammonia (NH3) and odour removal efficiencies per site were 38–74% and 43–62%, respectively; a large variation was found between measurements. Poor moisture control of the packing material decreased these efficiencies (breakthrough). Average fine dust (PM10) removal was mostly 90% or higher. It was found that a significant part of the NH3 may be converted to nitrous oxide (N2O), a potent greenhouse gas. At one site even 21% of all NH3-N was converted to NO2-N. It is the first time that such high average N2O production rates have been reported for long-term monitoring of biofilters. It is concluded that biofilters have potential for emission reduction at animal houses, but especially high pressure drop (clogging/fouling) and homogeneous moistening of the biobed need attention. To prevent breakthrough of air at dry spots, it is recommended to increase the media depth. Further research is necessary to explore the conditions and parameters that influence N2O production in this type of systems, as currently no control strategy is available for preventing N2O generation.

      PubDate: 2017-05-12T10:26:51Z
      DOI: 10.1016/j.biosystemseng.2017.04.007
      Issue No: Vol. 159 (2017)
       
  • Dynamic modelling of cut-and-store systems for year-round deliveries of
           short rotation coppice willow
    • Authors: Daniel Nilsson; Anders Larsolle; Nils-Erik Nordh; Per-Anders Hansson
      Pages: 70 - 88
      Abstract: Publication date: July 2017
      Source:Biosystems Engineering, Volume 159
      Author(s): Daniel Nilsson, Anders Larsolle, Nils-Erik Nordh, Per-Anders Hansson
      Short rotation coppice willow (SRCW) is a high-yielding energy crop that can be used to produce solid, liquid or gaseous biofuels. The crop is harvested during the winter, when the leaves have dropped. For economic reasons, however, most fuel processing plants require continuous year-round delivery of raw material. Thus, SRCW should be harvested as stems or in larger pieces in order to be storable, and not chipped directly at harvest for immediate use in large-scale heating plants, which is common practice at present. The aim of the project within which this study was conducted is to find cost-effective whole-stem harvesting and handling systems for year-round deliveries of natural-dried SRCW. A discrete event simulation model for such systems was developed in this study, taking weather, soil trafficability, geographical conditions, natural drying of the material and storage losses into account. The model was applied to a fictitious processing plant in Uppsala, Sweden. Machine performance and costs for a system with one stem harvester and up to three in-field shuttles, together with one chipper truck for chipping and transport, were investigated. The simulations showed that field trafficability had a crucial impact on total quantity harvested. The total cost was € 40 t−1 dry matter. Yield of SRCW and harvest productivity were important factors regarding costs. The model can be used to design cost-effective harvesting and handling systems for year-round deliveries of SRCW.

      PubDate: 2017-05-17T09:50:35Z
      DOI: 10.1016/j.biosystemseng.2017.04.010
      Issue No: Vol. 159 (2017)
       
  • Consistency of electrical and physiological properties of tea leaves on
           indicating critical cold temperature
    • Authors: Yongzong Lu; Yongguang Hu; Pingping Li
      Pages: 89 - 96
      Abstract: Publication date: July 2017
      Source:Biosystems Engineering, Volume 159
      Author(s): Yongzong Lu, Yongguang Hu, Pingping Li
      Critical cold temperature is the main control parameter for frost protection and has been indicated by testing plants electrical properties. But limited studies present a clear relationship between the response of electrical properties and critical cold temperature. The objective of this article is to analyse the relationship between physiological and electrical properties of tea leaf under freezing injury and validate the feasibility of using electrical properties to indicate the critical cold temperature. A system of measuring tea leaf's electrical property was established to obtain its typical temperature, at which the capacitance, impedance, resistance and reactance of tea leaves had obvious responses to cold stress. Relative electrical conductivity (REC) and cell damage rate of two cultivars (Fuding Dabai and Maolu) were measured under different cold stress conditions. Logistic regression analysis between REC and temperature was used to determine the low semi-lethal temperature (LT50). The results showed that the typical temperatures of Fuding Dabai and Maolu were −6.6 °C and −4.0 °C, respectively. REC of the two cultivars increased with the temperature decreasing from 0 to −10 °C and LT50 of Fuding Dabai and Maolu was −10.68 °C and −4.20 °C, respectively. The temperatures at which cell damage rate increased rapidly to 82.21% for Fuding Dabai and 77.93% for Maolu were −6.0 °C and −4.0 °C, respectively. When the electrical properties had obvious response at the typical temperatures, the cells were suffered serious cold stress and most of them were damaged. Therefore, the typical temperature could assess the freezing tolerance of tea leaves and indicate their critical cold temperature.

      PubDate: 2017-05-17T09:50:35Z
      DOI: 10.1016/j.biosystemseng.2017.04.012
      Issue No: Vol. 159 (2017)
       
  • Simulation and experimental test of waterless washing nozzles for fresh
           apricot
    • Authors: Hongkui Chu; Ruoyu Zhang; Yanjie Qi; Za Kan
      Pages: 97 - 108
      Abstract: Publication date: July 2017
      Source:Biosystems Engineering, Volume 159
      Author(s): Hongkui Chu, Ruoyu Zhang, Yanjie Qi, Za Kan
      To design a nozzle for washing fresh apricot with compressed air, four types of nozzles were studied by simulation and test methods. The working section for waterless washing was determined through the analysis of the air jet flow characteristics of the nozzles. In this working section, the best nozzle of the four tested was found through a comparison analysis of their flow characteristics by computational fluid dynamics (CFD) simulation and pressure-sensing test. The results showed that the trends of the simulation velocity and the test stress were consistent. A machine vision test was also conducted to assess the cleaning effect of the four nozzles. The results showed that the best nozzle was the column cone nozzle, and its average waterless washing efficiency was up to 99.07%. This study indicated that the combination of a simulation and an experimental test can be used to analyse and design waterless washing nozzles for fresh apricots.

      PubDate: 2017-05-22T09:56:54Z
      DOI: 10.1016/j.biosystemseng.2017.05.001
      Issue No: Vol. 159 (2017)
       
  • Prediction mapping of physicochemical properties in mango by hyperspectral
           imaging
    • Authors: Parika Rungpichayapichet; Marcus Nagle; Pasinee Yuwanbun; Pramote Khuwijitjaru; Busarakorn Mahayothee; Joachim Müller
      Pages: 109 - 120
      Abstract: Publication date: July 2017
      Source:Biosystems Engineering, Volume 159
      Author(s): Parika Rungpichayapichet, Marcus Nagle, Pasinee Yuwanbun, Pramote Khuwijitjaru, Busarakorn Mahayothee, Joachim Müller
      Hyperspectral imaging (HSI) techniques using a newly-developed frame camera were applied to determine internal properties of mango fruits including firmness, total soluble solids (TSS) and titratable acidity (TA). Prediction models were developed using spectral data from relative surface reflectance of 160 fruits in the visible and near infrared (vis/NIR) region of 450–998 nm analysed by PLS regression. For data reduction, MLR analysis showed 16 significant factors for firmness, 17 for TA, and 20 for TSS. The results of MLR did not substantially affect the prediction performance as compared to PLS. An original approach with combined chemometric and HSI data analyses was applied using R programming. Significant correlations were found between HSI data and firmness (R2 = 0.81 and RMSE = 2.83 N) followed by TA (R2 = 0.81 and RMSE = 0.24%) and TSS (R2 = 0.5 and RMSE = 2.0%). Prediction maps of physicochemical qualities were achieved by applying the prediction models to each pixel of HSI to visualise their spatial distribution. The variation of firmness, TSS, and TA within the fruit indicated fruit ripening started from shoulder toward to tip part. From these results, HSI can be used as a non-destructive technique for determining the quality of fruits which could potentially enhance grading capabilities in the industrial handling and processing of mango.
      Graphical abstract image

      PubDate: 2017-05-22T09:56:54Z
      DOI: 10.1016/j.biosystemseng.2017.04.006
      Issue No: Vol. 159 (2017)
       
  • Low frequency aeration of pig slurry affects slurry characteristics and
           emissions of greenhouse gases and ammonia
    • Authors: Salvador Calvet; John Hunt; Tom H. Misselbrook
      Pages: 121 - 132
      Abstract: Publication date: July 2017
      Source:Biosystems Engineering, Volume 159
      Author(s): Salvador Calvet, John Hunt, Tom H. Misselbrook
      Low frequency aeration of slurries may reduce ammonia (NH3) and methane (CH4) emissions without increasing nitrous oxide (N2O) emissions. The aim of this study was to quantify this potential reduction and to establish the underlying mechanisms. A batch experiment was designed with 6 tanks with 1 m3 of pig slurry each. After an initial phase of 7 days when none of the tanks were aerated, a second phase of 4 weeks subjected three of the tanks to aeration (2 min every 6 h, airflow 10 m3 h−1), whereas the other three tanks remained as a control. A final phase of 9 days was established with no aeration in any tank. Emissions of NH3, CH4, carbon dioxide (CO2) and N2O were measured. In the initial phase no differences in emissions were detected, but during the second phase aeration increased NH3 emissions by 20% with respect to the controls (8.48 vs. 7.07 g m−3 [slurry] d−1, P < 0.05). A higher pH was found in the aerated tanks at the end of this phase (7.7 vs. 7.0 in the aerated and control tanks, respectively, P < 0.05). CH4 emissions were 40% lower in the aerated tanks (2.04 vs. 3.39 g m−3 [slurry] d−1, P < 0.05). These differences in NH3 and CH4 emissions remained after the aeration phase had finished. No effect was detected for CO2, and no relevant N2O emissions were detected during the experiment. Our results demonstrate that low frequency aeration of stored pig slurry increases slurry pH and increases NH3 emissions.

      PubDate: 2017-05-22T09:56:54Z
      DOI: 10.1016/j.biosystemseng.2017.04.011
      Issue No: Vol. 159 (2017)
       
  • Estimating soil thermal diffusivity at different water contents from
           easily available data on soil texture, bulk density, and organic carbon
           content
    • Authors: Tatiana Arkhangelskaya; Ksenia Lukyashchenko
      Abstract: Publication date: Available online 8 July 2017
      Source:Biosystems Engineering
      Author(s): Tatiana Arkhangelskaya, Ksenia Lukyashchenko
      This study provides an algorithm to estimate soil thermal diffusivity at any water content from data on soil texture, bulk density, and percentage of organic carbon. Models were trained on the dataset of 77 soil samples including silty clays, silty clay loams, silt loams, clay loams, loams, sandy clay loams, sandy loams, loamy sands, and sands. The ranges of sand, silt, and clay within the dataset were 1–97, 2–80, and 1–52%; wet bulk density varied from 860 to 1820 kg m−3, organic carbon ranged from 0.1 to 6.5%. Thermal diffusivity of the undisturbed soil cores measured by the unsteady-state method was from 0.77 to 10.09 × 10−7 m2 s−1. The dataset was split randomly into the training set of 67 samples and the test set of 10 samples; the procedure was repeated three times. Models were developed from the measured thermal diffusivity vs. water content curves. The experimental data points for each sample were described by a 4-parameter function. Parameters of average curves for different textural classes were also determined. Then regression equations were obtained to estimate the parameters of the thermal diffusivity vs. water content function for different soils: (i) from soil texture; (ii) from soil texture and bulk density; (iii) from soil texture and organic carbon; (iv) from soil texture, bulk density, and organic carbon. The test set data were used to evaluate the model performance. The normalised root mean square errors of the best-performing models were from 20 to 33% depending on soil information available.
      Graphical abstract image

      PubDate: 2017-07-09T08:07:08Z
      DOI: 10.1016/j.biosystemseng.2017.06.011
       
  • Estimation of patterns in weaned piglets' activity using spectral analysis
    • Authors: Roberto Besteiro; Tamara Arango; Manuel R. Rodríguez; María D. Fernández; Ramón Velo
      Abstract: Publication date: Available online 29 June 2017
      Source:Biosystems Engineering
      Author(s): Roberto Besteiro, Tamara Arango, Manuel R. Rodríguez, María D. Fernández, Ramón Velo
      The activity level of weaned piglets provides a useful tool for farmers to control animal welfare and pollutant emissions. In addition, data for weaned piglet activity can be used as an input signal in real-time ventilation control systems because of its relation to temperature and CO2 levels. This paper characterises the daily activity pattern of piglets from 6 to 20 kg live body mass based on data obtained by a passive infrared detector on a conventional farm. Activity level of piglets was at its maximum at the beginning of the experimental period and at its minimum at the end of the period. The analysis of the Fast Fourier Transform revealed an average pattern with two activity peaks, at 10:00 h and 18:00 h, described by three cosine waves with 24-, 12- and 8-h periodicity. The Continuous Morlet Wavelet Transform revealed variations in frequency spectrum with time between the first and second half of the cycle, defining two distinct activity periods. The predominant pattern during the first half was a single-peak pattern, whereas the predominant pattern during the second half was a two-peak pattern. Accordingly, two models for the prediction of piglet activity are proposed. Animal age and mass are essential to define behaviour patterns, which explains the existence of various models in the literature and the need to perform continuous measurements to establish accurate models for predicting activity in growing piglets. Passive infrared detectors are simple and cost-effective, and allow for the incorporation of animal activity into real-time control on conventional farms.

      PubDate: 2017-07-09T08:07:08Z
      DOI: 10.1016/j.biosystemseng.2017.06.014
       
  • Assessing fresh urine puddle physics in commercial dairy cow houses
    • Authors: Dennis J.W. Snoek; Johannes D. Stigter; Sam K. Blaauw; Peter W.G. Groot Koerkamp; Nico W.M. Ogink
      Abstract: Publication date: Available online 11 May 2017
      Source:Biosystems Engineering
      Author(s): Dennis J.W. Snoek, Johannes D. Stigter, Sam K. Blaauw, Peter W.G. Groot Koerkamp, Nico W.M. Ogink
      Ammonia emission from dairy barns can be reduced by measures that improve removal of urine from floors. Information characterizing physical and chemical properties of urine puddles on floors are essential to improve mitigation measures, however information representative for practical barn conditions is scanty. The objective of this paper is to assess the area (A p ) and depth (D p ) of fresh urine puddles in commercial dairy barns, and to investigate the effect of floor type, season and manure scraping on these variables. Sixteen farms were measured in a factorial design of four Floor-Management types (FMTypes). Each farm was measured in two seasons and underwent an intense-floor-cleaning treatment (PREclean) before puddle creation for the D p measurement, which was compared with those created under normal floor conditions with on-farm manure scraping. Overall mean values were 0.83 m2 for A p and 1.0 mm for D p . For both A p and D p the variation within a farm was large but negligible between farms. FMType significantly affected both variables. The V-shaped asphalt floor resulted in larger A p (1.04 m2) and D p (1.5 mm) than those of slatted and grooved floors (mean values 0.76 m2, 0.93 mm). Our study demonstrates that the draining capacity of solid floors is a critical design issue in lowering ammonia emission. The PREclean treatment resulted in D p values that were 3 times lower than values for puddles created under normal floor conditions. We conclude that there is a considerable potential to improve draining of excreted puddles by increasing the cleaning performance of manure scrapers.

      PubDate: 2017-05-12T10:26:51Z
      DOI: 10.1016/j.biosystemseng.2017.04.003
       
  • Assessing fresh urine puddle chemistry in commercial dairy cow houses
    • Authors: Dennis J.W. Snoek; Johannes D. Stigter; Geert C.C. Kupers; Peter W.G. Groot Koerkamp; Nico W.M. Ogink
      Abstract: Publication date: Available online 26 April 2017
      Source:Biosystems Engineering
      Author(s): Dennis J.W. Snoek, Johannes D. Stigter, Geert C.C. Kupers, Peter W.G. Groot Koerkamp, Nico W.M. Ogink
      Ammonia emission mainly originates from urea in urine puddles on floors in dairy cow houses. This emission process can be modelled. However, required model inputs have not been updated recently. In addition, values for the model variables pH, Urinary Urea Nitrogen concentration (UUN), and their relation with farm and feed management are unknown for commercial dairy cow houses. Moreover, their effect on ammonia emission is unknown. Therefore, the objective of this paper was to investigate the pH and UUN in livestock practice. Sixteen commercial farms were measured in a factorial design of four Floor-Management types (FMTypes). Each farm was measured in two seasons and a Diet factor was defined, based on the amount of grass in total roughage. Overall mean values were 4.27 kg m−3 for UUN, an initial pH of 8.3, both in fresh puddles, and a pH(ξ) of 9.0 for random puddles at a random time. For UUN both the variation within and between farms was large, whereas the variation for pH was small. The Diet was the only factor that resulted in a significant effect, with a 0.1 difference in pH(ξ). Compared to the reference values, both the mean UUN and pH showed smaller values. The calculated potential ammonia in kg puddle−1, however, showed a huge range and was considerably larger than the commonly used reference values in the Netherlands.

      PubDate: 2017-05-01T10:04:14Z
      DOI: 10.1016/j.biosystemseng.2017.03.013
       
 
 
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