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  Subjects -> AGRICULTURE (Total: 793 journals)
    - AGRICULTURAL ECONOMICS (70 journals)
    - AGRICULTURE (557 journals)
    - CROP PRODUCTION AND SOIL (92 journals)
    - DAIRYING AND DAIRY PRODUCTS (28 journals)
    - POULTRY AND LIVESTOCK (46 journals)

AGRICULTURE (557 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: 3)
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 Horticultural Science     Open Access  
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: 16)
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)
Agric     Open Access  
Agricultura     Open Access   (Followers: 1)
Agricultura Tecnica     Open Access   (Followers: 5)
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: 45)
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: 39)
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 Biology Journal of North America     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: 54)
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: 28)
American Journal of Potato Research     Hybrid Journal   (Followers: 2)
American Journal of Rural Development     Open Access   (Followers: 5)
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: 2)
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: 29)
Australian Economic Review     Hybrid Journal   (Followers: 6)
Australian Forest Grower     Full-text available via subscription   (Followers: 4)
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   (Followers: 1)
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: 11)
Biosystems Engineering     Hybrid Journal   (Followers: 9)
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   (Followers: 1)
Buletin Veteriner Udayana     Open Access   (Followers: 3)
Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca : Food Science and Technology     Open Access   (Followers: 1)
Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca. Agriculture     Open Access   (Followers: 1)
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: 20)
Capitalism Nature Socialism     Hybrid Journal   (Followers: 12)
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: 3)
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: 32)
Cultural Studies - Critical Methodologies     Hybrid Journal   (Followers: 16)
Cultural Studies of Science Education     Hybrid Journal   (Followers: 6)
Cultural Trends     Hybrid Journal   (Followers: 15)
Culture, Agriculture, Food and Environment     Hybrid Journal   (Followers: 12)
Culture, Agriculture, Food and Environment     Hybrid Journal   (Followers: 7)
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: 148)
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: 63)
Economic Record     Hybrid Journal   (Followers: 7)
Emirates Journal of Food and Agriculture     Open Access   (Followers: 1)
Empirical Economics     Hybrid Journal   (Followers: 15)
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: 6)
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: 11)
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: 64)
European Review of Agricultural Economics     Hybrid Journal   (Followers: 11)
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)

        1 2 3 | Last

Journal Cover Biosystems Engineering
  [SJR: 0.824]   [H-I: 77]   [9 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]
  • Potential of turbulence interference in rough rice bin drying and storage
           systems fitted with cabling technology
    • Authors: Gbenga A. Olatunde; Griffiths G. Atungulu
      Pages: 1 - 14
      Abstract: Publication date: November 2017
      Source:Biosystems Engineering, Volume 163
      Author(s): Gbenga A. Olatunde, Griffiths G. Atungulu
      Modern on-farm in-bin drying and storage systems are equipped with networks of sensors to monitor air and grain conditions throughout the bins. However, the performance of sensors may be impaired by turbulent flow of the air through the grain mass. Computational fluid dynamic (CFD) simulations allow a more detailed view of fluid flow around the sensors to be obtained. The objectives of this work are to investigate the potential of turbulence generation around the sensors and the potential of turbulence to impair sensor performance. A finite volume method with porous media formulation was employed to simulate the turbulent airflow. The turbulence intensities predicted from different turbulence models (K−ɛ model, k−ω model and the Reynolds stress model (RSM)) were investigated and the result of airflow rates of 1.1 m3 min−1 [air] t−1 [rice] is presented. The results revealed that the turbulence models predicted a low to medium turbulence with intensities ranging between 1% and 2%. Sensors closer to the plenum experienced about 100% increase in turbulence intensity compared to the sensors closer to the outlet. Comparing the turbulence models used, RSM model require the least computational duration with average of 5 h simulation time compared with K–ɛ model and k –ω model requiring 9–42 h and 40 h, respectively. It can be concluded that sensors closer to the plenum should be built to cope with medium scale turbulent flow.

      PubDate: 2017-09-08T09:15:21Z
      DOI: 10.1016/j.biosystemseng.2017.08.010
      Issue No: Vol. 163 (2017)
       
  • Investigating air leakage and wind pressure coefficients of single-span
           plastic greenhouses using computational fluid dynamics
    • Authors: Takeshi Kuroyanagi
      Pages: 15 - 27
      Abstract: Publication date: November 2017
      Source:Biosystems Engineering, Volume 163
      Author(s): Takeshi Kuroyanagi
      Air leakage from greenhouses not only influences heating load and the carbon dioxide supply, but also affects wind loads on the greenhouse structure. Quantitative evaluation of the greenhouse air leakage is essential to estimate variable costs and achieve reasonable designs for greenhouses with adequate strength. In this study, greenhouse leakage rate was estimated through a combination of CFD simulation of the external pressure coefficients of the greenhouse cladding and modelling of airflow through leakage paths on the greenhouse walls. The simulation results of the leakage rate were validated by the experimental results obtained from two greenhouses with the same structure but different orientation. The correlation coefficients between the simulated and measured values ranged from 0.82 to 0.99, and the RMSE of the simulated leakage rate ranged from 0.014 to 0.052. The simulation results indicated that a strong transverse wind created lower leakage rate and internal pressure coefficient. These findings and methodology will be helpful for designing light-weight greenhouses in windy regions.

      PubDate: 2017-09-08T09:15:21Z
      DOI: 10.1016/j.biosystemseng.2017.08.004
      Issue No: Vol. 163 (2017)
       
  • The impact of transient heat transfer on tissue culture cell distribution
    • Authors: Jeffrey D. Brown; Heather E. Dillon; Dorcas V. Kaweesa; Arden M. Harada
      Pages: 28 - 36
      Abstract: Publication date: November 2017
      Source:Biosystems Engineering, Volume 163
      Author(s): Jeffrey D. Brown, Heather E. Dillon, Dorcas V. Kaweesa, Arden M. Harada
      It is common practice to subculture adherent eukaryotic cells in multi-well plates at room temperature before 37 °C incubation for growth. Under these conditions, cell distribution was non-uniform with a higher density of cells near the edges of the wells. Non-uniform cell density can alter cell behaviour in numerous biological assays and can result in variability when using automated plate readers on intact cells. This study investigated the possibility that the non-uniform cell distribution was caused by temperature gradients in the growth medium and well walls. Cell density analyses revealed significantly greater cell densities near well walls. Temperature distribution was documented using infrared imaging and temperature-sensitive LCD films, and a transient heat transfer mathematical model was developed to characterise the system and compared to the cell density results. The model predicts that an initial less-than-1 °C temperature gradient is present in the well shortly after initiating 37 °C incubation, leading to preferential cell adhesion to the warmer edges of wells in the first ∼30 min of incubation. Techniques to remediate non-uniform cell distribution were evaluated, and a simple method proved effective to promote uniform cell densities across wells of 24-well plates.
      Graphical abstract image

      PubDate: 2017-09-08T09:15:21Z
      DOI: 10.1016/j.biosystemseng.2017.08.009
      Issue No: Vol. 163 (2017)
       
  • Detection and continuous monitoring of localised high-moisture regions in
           a full-scale grain storage bin using electromagnetic imaging
    • Authors: Mohammad Asefi; Colin Gilmore; Ian Jeffrey; Joe LoVetri; Jitendra Paliwal
      Pages: 37 - 49
      Abstract: Publication date: November 2017
      Source:Biosystems Engineering, Volume 163
      Author(s): Mohammad Asefi, Colin Gilmore, Ian Jeffrey, Joe LoVetri, Jitendra Paliwal
      The performance of a radio-frequency grain bin imaging system, used for stored grain monitoring in an industrial scale (80 t) hopper-bottom grain bin, is investigated via a variety of experimental tests. The system is comprised of 24 magnetic field transmitter/receiver probes mounted on the inner walls of the bin. The system quantitatively images the dielectric properties of the grain which can then be used as indirect indicators of moisture content, temperature, insect infestation, and other anomalous physiological features. In this paper, we show that the imaging system is capable of detecting induced localised high moisture anomalies in 48 t of hard red winter wheat. These localised moisture anomalies consist of approximately 60 kg bags of wheat that have had their moisture content increased to a specified amount. Outside of these controlled regions the grain is heavily infested with red flour and rusty grain beetles. The moisture content is detectable within the images. Experiments with single and multiple regions of varying moisture content, as well as a ten-day study of the evolution of a single initial moisture region over time are presented.

      PubDate: 2017-09-08T09:15:21Z
      DOI: 10.1016/j.biosystemseng.2017.08.015
      Issue No: Vol. 163 (2017)
       
  • A 3-D model to predict the temperature of liquid manure within storage
           tanks
    • Authors: Timothy J. Rennie; Hambaliou Baldé; Robert J. Gordon; Ward N. Smith; Andrew C. VanderZaag
      Pages: 50 - 65
      Abstract: Publication date: November 2017
      Source:Biosystems Engineering, Volume 163
      Author(s): Timothy J. Rennie, Hambaliou Baldé, Robert J. Gordon, Ward N. Smith, Andrew C. VanderZaag
      A numerical model was developed to determine the year-round temperature distribution within liquid manure storages, which is relevant for modelling temperature-dependent greenhouse gas and ammonia emissions. The model considers net short and long-wave radiation, heat conduction through walls and floor, surface convective heat transfer, evaporative heat loss, and manure loading. The model was implemented and validated for a circular concrete storage tank (40 m diameter; 2.5 m depth) on a dairy farm in Ontario, Canada, where it is assumed that heat transfer occurs in horizontal and vertical directions, and is symmetric in the angular direction. Annual root mean square error (RMSE), Nash–Sutcliffe model efficiency, coefficient of determination, and average bias between model estimates and measured values were 2.4 °C, 0.91, 0.95, and 0.12 °C, respectively. The model performed best in summer and autumn (lowest RMSE), which are the most important seasons for modelling temperature, as both temperature and manure volume are highest, leading to the greatest opportunity for gaseous emissions. A sensitivity analysis indicated that the most significant parameters were solar absorptivity, manure depth, incoming manure temperature, emissivity, and wind-speed. For every unit increase in depth (m), incoming manure temperature (°C), or wind-speed (m s−1), the peak summer temperature changed by −7.3, 0.3, or −2.4 °C, respectively. Parameters with little effect on temperature were the manure solids content and thermal conductivity of soil around the sides and the bottom of the tank. Results show that heat transfer is primarily 1-dimensional, and a simplified 1-D model would be sufficient for future applications.

      PubDate: 2017-09-08T09:15:21Z
      DOI: 10.1016/j.biosystemseng.2017.08.014
      Issue No: Vol. 163 (2017)
       
  • Microclimate and agronomical effects of internal impermeable screens in an
           unheated Mediterranean greenhouse
    • Authors: Joaquín Hernández; Santiago Bonachela; María R. Granados; Juan C. López; Juan J. Magán; Juan I. Montero
      Pages: 66 - 77
      Abstract: Publication date: November 2017
      Source:Biosystems Engineering, Volume 163
      Author(s): Joaquín Hernández, Santiago Bonachela, María R. Granados, Juan C. López, Juan J. Magán, Juan I. Montero
      In unheated greenhouses in mild-winter areas, low-cost, fixed, water-impermeable plastic screens are frequently installed in winter cycles of the vegetable crops more sensitive to fungal diseases. They are used to prevent rain and condensation falling on the crop and to improve the greenhouse air temperature. Two experiments were carried out to quantify how fixed and movable impermeable screens affect microclimate and crop behaviour in an unheated greenhouse in a mild-winter area. The fixed screen improved the night-time temperature and humidity of the air below the screen, and reduced the water condensation on its inner plastic surface or the proliferation of fungal diseases, but did not completely prevent it. Compared to the greenhouse without screen, the movable screen, usually unfolded at night, increased the night-time temperature of the air and the crop, reduced the night-time relative humidity of the air below the screen, prevented the water condensation on the screen or the crop, accelerated melon crop development, and significantly increased early marketable yield of melon fruits and their quality, but it did not substantially affect the substrate temperature, or the total marketable yield of melon fruits. In the comparison of the greenhouse with fixed versus movable screen, no substantial differences were found for a winter cucumber cycle in night-time temperature and relative humidity of the air below the screens, in shoot biomass or in fresh weight of total and marketable cucumber fruits. This can be mainly attributed to the small differences between both treatments in the shortwave radiation reaching the crop.

      PubDate: 2017-09-14T01:05:51Z
      DOI: 10.1016/j.biosystemseng.2017.08.012
      Issue No: Vol. 163 (2017)
       
  • Soil rut depth prediction based on soil strength measurements on typical
           Estonian soils
    • Authors: Kersti Vennik; Thomas Keller; Peeter Kukk; Kadri Krebstein; Endla Reintam
      Pages: 78 - 86
      Abstract: Publication date: November 2017
      Source:Biosystems Engineering, Volume 163
      Author(s): Kersti Vennik, Thomas Keller, Peeter Kukk, Kadri Krebstein, Endla Reintam
      Deep ruts in soil hinder the movement of off-road vehicles and harm drastically the soil environment. The aim of this study was to determine the most suitable cone and remoulding index based methods for rut depth estimation for single and repeated military vehicle passage in typical Estonian soils. Cone index based sinkage models – US Army ERDC, Maclaurin (1990) and Willoughby and Turnage sinkage models applicable for military vehicles were tested, using different critical layers (0–15 cm, 7.5–23 cm or 15–30 cm). The test vehicles were a 7 Mg truck and a 23 Mg armoured personnel carrier. At eight experimental sites covering mechanically very variable soil conditions (from peat to clay soil), rut depth was measured after one and ten vehicle passes, cone penetration tests were conducted in situ, and samples were collected for determination of bulk density, organic carbon content, texture, gravimetric water content, plastic and liquid limits of the topsoil and subsoil. According to average RMSD values for military truck the Willoughby and Turnage model was the most accurate prediction method. For one pass and 10 passes the rating cone index values from the 7.5–23 cm and 15–30 cm soil layer, respectively, produced the lowest RMSD values.

      PubDate: 2017-09-14T01:05:51Z
      DOI: 10.1016/j.biosystemseng.2017.08.016
      Issue No: Vol. 163 (2017)
       
  • Use of electrostatic precipitators in small-scale biomass furnaces to
           reduce particulate emissions from a range of feedstocks
    • Authors: John Carroll; John Finnan
      Pages: 94 - 102
      Abstract: Publication date: November 2017
      Source:Biosystems Engineering, Volume 163
      Author(s): John Carroll, John Finnan
      The results of a study into the precipitation efficiencies of two different electrostatic precipitator (ESP) types (chimney top with manual cleaning and in-line with automated cleaning) using three biomass fuels with low (wood), medium (willow) and high (tall fescue) particulate emission levels are presented. Testing showed that precipitation efficiencies of greater than 70% are possible in an inline system with automated cleaning, while in the chimney top, manual cleaning system high efficiencies can be achieved for willow (86%) and wood (69%) on a short term basis. For low emission fuels such as wood (<10 mg Nm−3), acceptable precipitation efficiencies (∼70%) could be achieved and maintained over a long time period on both automated and manual systems. For medium (willow > 100 mg Nm−3) and high (tall fescue > 300 mg Nm−3) emission fuels it was found that the use of an automated cleaning system is necessary to maintain precipitation efficiencies at acceptable levels. In the chimney top type, system efficiencies dropped to zero with willow after 50 h and with tall fescue after 10 h of combustion with no cleaning, due to build-up of particulate matter on the electrode causing reduced distribution of charge to the oncoming particles. For the in-line system, it was also shown that an improved electrode design had the capacity to increase precipitation efficiency by on average 18%. It was concluded that ESPs have an important role to play in particulate emission reduction in future low emission biomass combustion systems if they are to meet stricter particulate control guidelines.

      PubDate: 2017-09-20T02:23:47Z
      DOI: 10.1016/j.biosystemseng.2017.08.021
      Issue No: Vol. 163 (2017)
       
  • Role of large inhomogeneities in initiating liquid sheet breakup in
           agricultural atomisation
    • Authors: Steven A. Cryer; Anthony L. Altieri
      Pages: 103 - 115
      Abstract: Publication date: November 2017
      Source:Biosystems Engineering, Volume 163
      Author(s): Steven A. Cryer, Anthony L. Altieri
      It is known that agricultural emulsifiable concentrate (EC) formulations reduce the fraction of fine spray produced during atomisation when compared with water. In recent years researchers inferred why EC formulations spray differently when multiple phases are present. The dispersed phase (e.g., oil drops/solid particles) is responsible for creating holes within the sheet, where the holes grow and merge to form liquid bridge ligaments which stretch and then breakup into droplets. Creating an inhomogeneous formulation of water and oil is a necessary, but not sufficient condition, to reduce the fine droplets produced during atomisation. The dispersed phase must also be of sufficient size and wettability (hydrophobicity) to create holes within the spray sheet emanating from agricultural nozzles. This manuscript describes the mechanics of creating perforations in liquid sheets using inhomogeneities within the spray solution. Perforations alter the sheet breakup mechanism leading to a reduction of very small drops (e.g., driftable fines) when atomised. Therefore, the number and location of perforations within the sheet can be used to control sheet breakup and droplet size distribution upon atomisation, based upon proof-of-concept experimental observations, surface energy minimisation principles, an overview of the various antifoaming agents that have been reported in literature (solids, oil globules, micelles), along with physical mechanisms for hole growth. Understanding the multiphase fluid parameters and atomisation process conditions that lead to hole perforation in liquid sheets (i.e., inhomogeneities) provides the basis for a priori formulation design based solely on physicochemical properties of formulation components.

      PubDate: 2017-09-26T02:38:36Z
      DOI: 10.1016/j.biosystemseng.2017.08.020
      Issue No: Vol. 163 (2017)
       
  • Investigation on the heat loss characteristic of underground household
           biogas digester using dynamic simulations and experiments
    • Authors: Yanfeng Liu; Yaowen Chen; Tao Li; Dengjia Wang; Daokun Wang
      Pages: 116 - 133
      Abstract: Publication date: November 2017
      Source:Biosystems Engineering, Volume 163
      Author(s): Yanfeng Liu, Yaowen Chen, Tao Li, Dengjia Wang, Daokun Wang
      Underground household biogas digesters (UHBD) may achieve higher gas production in cold environments by adopting heating and insulation technologies. Fully understanding the heat loss characteristic of UHBD is the prerequisite to put these technologies into application. Here, a 3-D unsteady heat transfer model coupled with the digester and surrounding soil was developed to more accurately calculate the dynamic heat loss of UHBD. The solar-air temperature (SAT) was taken as the ground surface boundary condition parameter to describe the comprehensive influences of air convection, solar radiation, and long-wave radiation. Field experiments provided the initial and boundary conditions of the model. Furthermore, the changes in the digester heat loss process and the heat response process of the soil temperature under experimental condition were measured to create a more accurate model. The comparison between the numerical and experimental results showed that the errors were minimal when adopting SAT as the boundary condition parameter, in which the maximum error of average heat flux was 5.9%. Therefore, using the SAT boundary model, heat dissipation was calculated under different fermentation temperatures, burial depths, materials, and tectonic forms. The optimal fermentation temperature was 35 °C for maximum net energy production. Heat loss exponentially decreased with increase in burial depth. Insulation could significantly reduce the heat loss of a digester. The heat loss intensity could be decreased by 67.1% when the insulation was increased to 30 mm.

      PubDate: 2017-10-04T03:43:58Z
      DOI: 10.1016/j.biosystemseng.2017.09.002
      Issue No: Vol. 163 (2017)
       
  • Variable air assistance system for orchard sprayers; concept, design and
           preliminary testing
    • Authors: Ryszard Hołownicki; Grzegorz Doruchowski; Waldemar Świechowski; Artur Godyń; Paweł J. Konopacki
      Pages: 134 - 149
      Abstract: Publication date: November 2017
      Source:Biosystems Engineering, Volume 163
      Author(s): Ryszard Hołownicki, Grzegorz Doruchowski, Waldemar Świechowski, Artur Godyń, Paweł J. Konopacki
      Conventional air-assisted sprayers with hydraulic nozzles generate large radial spray plumes which produce significant off-target losses and can consume high power (20–30 kW). Also, it is not uncommon to see these machines treating dwarf orchards, where the spray losses at the full leaf stage may be over 80% of applied spray volume. Significant reductions in spray losses can be obtained with targeted and wind-oriented airflow adjustment. The objectives of the presented studies were to develop an energy saving variable air assistance (VAA) system with continuous real-time adjustment of air volume and with spraying systems mounted on both sides of the sprayer. The system is based on a double axial fan system which allows for remote adjustment of air volume. The nominal air output was 20,000 m3 h−1, for use in typical dwarf and semi-dwarf orchards, and this was designed to be obtained with 10 kW power consumption. The system used variable speed impellers with fixed blades which showed greater suitability than a method with adjustable pitch blades working at constant speed because it provided a wider range of air volumes (±35%). The air volumes produced could be continuously adjusted to obtain airflow profiles, on both sides of the sprayer that were almost symmetrical. The results obtained in tests appear to meet the objectives and, therefore, the VAA system can be considered as a suitable prototype platform for variable rate technology and future intelligent orchard sprayers.

      PubDate: 2017-10-04T03:43:58Z
      DOI: 10.1016/j.biosystemseng.2017.09.004
      Issue No: Vol. 163 (2017)
       
  • A liquid injection dosing system for site-specific fertiliser management
    • Authors: Marcelo J. da Silva; Paulo S.G. Magalhães
      Pages: 150 - 158
      Abstract: Publication date: November 2017
      Source:Biosystems Engineering, Volume 163
      Author(s): Marcelo J. da Silva, Paulo S.G. Magalhães
      Based on the Best Management Practices (BMPs) for nitrogen fertilisation, site-specific management must consider the most appropriate placement as well as the appropriate application rate according to local agronomic recommendations. Nitrogen fertilization on the soil surface (e.g., broadcasting, side dressing) is a common practice associated with high N loss to the environment and a low fertiliser recovery efficiency compared to the deep placement of fertiliser. We have worked to implement site-specific fertiliser management that encompasses a mechanised soil punching process combined with liquid fertiliser injection, which causes minimal disturbance of the soil subsurface (i.e., roots, soil or straw) and harmonises with conservative tillage practice. The objective was to design a hydraulic injection system to enable site-specific management according to the BMPs, as applied to mechanised soil punching to implement soil injection fertiliser placement. In this context, an injection dosing system (conceptual design, laboratory evaluations and analyses) has been developed to perform liquid injection synchronised with soil punching and variable rate application. In general, the applications were satisfactory because (i) the liquid injection was synchronised with soil punching and the fluid was incorporated into the soil at a depth greater than 50 mm, which was an appropriate deep placement with the potential to reduce nutrient losses combined by increasing nutrient uptake. In addition, (ii) the application rate was varied in a representative range (5.0 up to 18 ml cycle−1), which demonstrated a good potential for soil injection of fertiliser as a function of the local agronomic recommendations. Both conditions were aligned with the BMPs.

      PubDate: 2017-10-11T05:14:26Z
      DOI: 10.1016/j.biosystemseng.2017.09.005
      Issue No: Vol. 163 (2017)
       
  • Changes in soil compaction indicators in response to agricultural field
           traffic
    • Authors: Renato P. de Lima; Alvaro P. da Silva; Neyde F.B. Giarola; Anderson R. da Silva; Mário M. Rolim
      Pages: 1 - 10
      Abstract: Publication date: October 2017
      Source:Biosystems Engineering, Volume 162
      Author(s): Renato P. de Lima, Alvaro P. da Silva, Neyde F.B. Giarola, Anderson R. da Silva, Mário M. Rolim
      In addition to measurements of soil bulk density, compaction is usually measured by changes in soil porosity and penetration resistance. The effects of agricultural field traffic on changes in soil compaction indicators were investigated, a) to quantify the immediate effects of field traffic on the degree of compactness, penetration resistance, and matric suction and b) to evaluate the behaviour of these variables as indicators of post-traffic compaction on soils with different clay content. Two wheeling experiments were performed on two oxisols containing 200 (sandy clay loam) and 480 g kg−1 [clay] (i.e. clay soil). Compaction occurred after wheeling in both soils, but the degree of compactness was higher for the clay soil. Texture affected the behaviours of penetration resistance and matric suction in detecting compaction. With the increase in clay fraction, friction effects diminished, and variation in penetration resistance was not significant, even with compaction. Reductions in soil porosity due to compaction can cause variation in pore size and in the degree of saturation, altering the water retention energy. Due to the proportionally smaller pore size, this mechanism was detected via matric suction at approximately field capacity only for the clay soil. For the sandy loam soil, it is likely that only a larger reduction in porosity and variation in the degree of saturation impose detectable changes in matric suction.

      PubDate: 2017-09-02T09:05:30Z
      DOI: 10.1016/j.biosystemseng.2017.07.002
      Issue No: Vol. 162 (2017)
       
  • Effect of roof height on microclimate and plant characteristics in an
           insect-proof screenhouse with impermeable sidewalls
    • Authors: Meir Teitel; Hao Liang; Josef Tanny; Monica Garcia-Teruel; Asher Levi; Pablo F. Ibanez; Hana Alon
      Pages: 11 - 19
      Abstract: Publication date: October 2017
      Source:Biosystems Engineering, Volume 162
      Author(s): Meir Teitel, Hao Liang, Josef Tanny, Monica Garcia-Teruel, Asher Levi, Pablo F. Ibanez, Hana Alon
      An experiment was conducted to study the effect of structure height on air temperature and humidity, on air exchange rate and on transpiration and yield in an insect-proof screenhouse. Two houses with roof heights of 4 and 6 m, and impermeable polyethylene sheets on the sidewalls were examined. Air exchange with the outside environment took place only through the horizontal screened roof and tomato plants were grown in both houses. The results showed that the increase in screenhouse height from 4 to 6 m elicited almost no changes in daily mean air temperature, humidity ratio and consequently, in relative humidity within the canopy. However, it reduced by about 30% the airflow through the screenhouse and consequently the air exchange rate. Moreover, the increase in height did not elicit changes in crop transpiration, yield and plant development. Thus, it is concluded that in insect-proof screenhouses that are ventilated through the roof, there is no benefit in increasing structure height above the current common height of about 4 m.

      PubDate: 2017-09-02T09:05:30Z
      DOI: 10.1016/j.biosystemseng.2017.07.001
      Issue No: Vol. 162 (2017)
       
  • Discrimination of winter wheat disease and insect stresses using
           continuous wavelet features extracted from foliar spectral measurements
    • Authors: Jingcheng Zhang; Ning Wang; Lin Yuan; Fengnong Chen; Kaihua Wu
      Pages: 20 - 29
      Abstract: Publication date: October 2017
      Source:Biosystems Engineering, Volume 162
      Author(s): Jingcheng Zhang, Ning Wang, Lin Yuan, Fengnong Chen, Kaihua Wu
      Discrimination of crop diseases and insect damages is a critical task in pest management. As a non-contact and non-destructive method, spectroscopy has been recognised as an efficient way for crop pest detection. In this study, an advanced spectral analysis method, the continuous wavelet analysis (CWA), was used to discriminate three common diseases and insect damages in wheat crop: yellow rust, powdery mildew and aphid. In this research, leaf spectra were measured in both infected and reference plots at early grain filling stage. An algorithm was developed based on the continuously decomposed wavelet scalogram to identify types and severities of the damages. Its sensitivity and discrimination capability to damages were evaluated. Utilising an overlapping strategy, a wavelet feature selection method was established to identify optimal wavelet features discriminate the damages. Then, the discriminant model was developed based on the Fisher's linear discriminant analysis (FLDA). A total of six wavelet features with a central wavelength varying from 430 to 930 nm and scale factors of 4–8 were identified. According to a k-fold cross-validation, the averaged overall accuracy of the developed discriminant model was 77%. The CWA-based spectral discrimination approach showed good potential to serve as a basis to develop in-field, real-time, multi-damage mapping systems.

      PubDate: 2017-09-02T09:05:30Z
      DOI: 10.1016/j.biosystemseng.2017.07.003
      Issue No: Vol. 162 (2017)
       
  • Determination of diffusion and convective transfer coefficients in food
           drying revisited: A new methodological approach
    • Authors: Francisco J. Arranz; Tatiana Jiménez-Ariza; Belén Diezma; Eva C. Correa
      Pages: 30 - 39
      Abstract: Publication date: October 2017
      Source:Biosystems Engineering, Volume 162
      Author(s): Francisco J. Arranz, Tatiana Jiménez-Ariza, Belén Diezma, Eva C. Correa
      It is usual to determine diffusion and convective transfer coefficients using classical approximate relationships involving dimensionless numbers. These approximate relationships were developed in the past, in order to avoid the difficulties associated with calculations of large series expansions and its corresponding expansion coefficients given by transcendental equations. However, the development of improved computing techniques has removed these difficulties, such that currently such calculations can be easily performed. An iterative methodology is proposed that takes advantage of current computational capabilities, avoiding to use approximate relationships. The proposed methodology is applied to generated data and also to experimental data from carrot drying. Additionally, a Matlab ® implementation of the proposed iterative methodology, along with the input data files corresponding to the results presented in this paper, is provided as supplementary material.

      PubDate: 2017-09-02T09:05:30Z
      DOI: 10.1016/j.biosystemseng.2017.07.005
      Issue No: Vol. 162 (2017)
       
  • Determination of the moisture content of fresh meat using visible and
           near-infrared spatially resolved reflectance spectroscopy
    • Authors: Jian-Xu Wang; Li-Feng Fan; Hai-Hua Wang; Peng-Fei Zhao; Hao Li; Zhong-Yi Wang; Lan Huang
      Pages: 40 - 56
      Abstract: Publication date: October 2017
      Source:Biosystems Engineering, Volume 162
      Author(s): Jian-Xu Wang, Li-Feng Fan, Hai-Hua Wang, Peng-Fei Zhao, Hao Li, Zhong-Yi Wang, Lan Huang
      The moisture content of intact pork meat was determined employing near-infrared non-destructive reflectance spectroscopy. The effects of various factors, namely the shape of the probe, the contact between the probe and sample and the modelling method, were also evaluated. Wavelengths in the range from 600 to 1100 nm, two spectra collection methods and three corresponding data processing methods were considered. Spectra were collected using a conventional Y-shaped optical fibre probe and an optical probe for steady-state spatially resolved detection. In the experiments, we can obtain the spectral information from the depth approximately 3 mm–4 mm or 4 mm–5 mm when the separation of the detector and the source is 6 mm or 9 mm, respectively. Models were established using data obtained with the steady-state spatially resolved probe (41 samples) and the Y-shaped optical probe (28 samples). Using the three-wavelength and Partial-least-squares regression (PLSR) calibration methods, the Y-shaped probe provided models with R2 values of 0.0097 and 0.36 respectively, whereas the steady-state spatially resolved probe provided models with R2 values of 0.3692 and 0.7769 respectively. Applying a successive-projection algorithm combined with multiple linear regressions to the data of the steady-state spatially resolved probe, the R2 of the obtained model was 0.8078. Near-infrared steady-state spatially resolved spectroscopy is thus an effective technique for predicting the moisture content of intact pork.

      PubDate: 2017-09-02T09:05:30Z
      DOI: 10.1016/j.biosystemseng.2017.07.004
      Issue No: Vol. 162 (2017)
       
  • Assimilation of canopy cover and biomass measurements in the crop model
           AquaCrop
    • Authors: Raphael Linker; Ilya Ioslovich
      Pages: 57 - 66
      Abstract: Publication date: October 2017
      Source:Biosystems Engineering, Volume 162
      Author(s): Raphael Linker, Ilya Ioslovich
      Measurements indicative of crop development, such as leaf area index, canopy cover or biomass are typically performed only a few times throughout the season at irregular time intervals. Furthermore, due to the inherent spatial variability that exists in the field, combining measurements taken at different locations in the field usually leads to large uncertainty around the mean value. These factors, together with the fact that crop-soil models are strongly non-linear, render assimilation of measurements in crop-soil models non-trivial. This work presents procedures for performing such data assimilation, using the crop model AquaCrop as specific example. The procedures are based on Extended Kalman Filter, with some heuristic adjustments, and enable re-initialisation of state variables and/or adjustments of selected parameters of the model. The uncertainties of the measurements are taken into account explicitly in the proposed assimilation scheme. The procedures were tested with data obtained from experiments conducted with potato in Denmark and cotton in Greece. In both cases the data available consisted of canopy cover and biomass (average and standard deviation on 5–10 days), and a locally-calibrated AquaCrop model was used as starting point for the assimilation process. The results demonstrate the soundness of the approach but also emphasise the inherent limitations associated with data assimilation. In particular, assimilation of easy-to-obtain canopy cover measurements did not always improve the predictions of biomass.

      PubDate: 2017-09-02T09:05:30Z
      DOI: 10.1016/j.biosystemseng.2017.08.003
      Issue No: Vol. 162 (2017)
       
  • Geochemical modelling of livestock mortality leachate transport through
           the subsurface
    • Authors: Dyan L. Pratt; Terrance A. Fonstad
      Pages: 67 - 80
      Abstract: Publication date: October 2017
      Source:Biosystems Engineering, Volume 162
      Author(s): Dyan L. Pratt, Terrance A. Fonstad
      Leachate chemistry arising from carcass disposal burial pits may pose a significant threat to the environment. Based on the results of previous studies, models were created to assess these impacts. Simple 2D models using CTRAN were created to evaluate the impacts of three orders of magnitude changes in hydraulic conductivity representative of glacial tills common to Western Canada, as well as impacts of burial trench/pit spacing on the subsurface for a conservative ion. Sorption properties were included in one scenario to provide insight on transport and sorption for ammonium ions based on published distribution coefficients. The conservative and sorption models for the mid-range hydraulic conductivity indicated transport up to 10 m after 100 years with concentrations at 40% and 1% of initial values respectively for the conservative and sorption model. The CTRAN sorption model estimates ion sorption, but does not account for ion exchange effects with soil properties, therefore, PHREEQC was used to also provide a geochemical contaminant transport model including ion exchange reactions occurring along the flow path. The PHREEQC model demonstrated elevated concentrations of a calcium and magnesium plume forming in front of an ammonium plume due to ion exchange occurring on the soil particles. After 50 years of transport, ammonium concentrations were approximately 4% of initial values in a soil with a cation exchange capacity (CEC) of 10 meq [100 g]−1. Modelling demonstrated high concentrations of ammonium, orthophosphate, sulphate and other ions in mortality leachate where transport and precipitation of these ions could occur beyond 100 years.

      PubDate: 2017-09-02T09:05:30Z
      DOI: 10.1016/j.biosystemseng.2017.08.002
      Issue No: Vol. 162 (2017)
       
  • Evaluation of manure drying tunnels to serve as dust filters in the
           exhaust of laying hen houses: Emissions of particulate matter, ammonia,
           and odour
    • Authors: Albert Winkel; Julio Mosquera; André J.A. Aarnink; Peter W.G. Groot Koerkamp; Nico W.M. Ogink
      Pages: 81 - 98
      Abstract: Publication date: October 2017
      Source:Biosystems Engineering, Volume 162
      Author(s): Albert Winkel, Julio Mosquera, André J.A. Aarnink, Peter W.G. Groot Koerkamp, Nico W.M. Ogink
      Poultry houses are important emission sources of ammonia, odour, and particulate matter (PM). Manure drying tunnels (MDTs) might act as ‘end of pipe’ PM filters, but might also emit additional ammonia and odour. This study aimed to gain insight into this matter (parts A and B) and into the perspective of two strategies to reduce additional emissions: (1) by pre-drying the manure on the belts inside the house (part C), and (2) by reducing manure accumulation time (MAT) in the house to 24-h followed by rapid drying inside the MDT (part D). This study was set up as an emission survey at 16 laying hen farms with a MDT. Results from parts A through C showed that PM10 removal efficiency of the MDTs increases linearly with manure layer thickness: from about 35% at 4 cm to 84% at 17 cm. Ammonia and odour concentrations in the drying air increased substantially upon passing the manure layers, from on average 5.5 to 13.9 ppm ammonia and from 822 to 1178 OUE m−3. In part C, ammonia emission decreased with increasing DM content of the manure, but even at DM content levels beyond 50%, substantial ammonia emission remained. In part D, the emission rates of houses and MDTs together were 44% lower for PM10, 20% higher for ammonia, and 40% higher for odour compared with the theoretical situation of the houses without MDT. Further shortening MAT to 18, 12, or 6 h might be needed to reduce emissions from MDTs.

      PubDate: 2017-09-02T09:05:30Z
      DOI: 10.1016/j.biosystemseng.2017.07.006
      Issue No: Vol. 162 (2017)
       
  • Investigation on optimal spray properties for ground based agricultural
           applications using deposition and retention models
    • Authors: Nicolas De Cock; Mathieu Massinon; Sofiene O.T. Salah; Frédéric Lebeau
      Pages: 99 - 111
      Abstract: Publication date: October 2017
      Source:Biosystems Engineering, Volume 162
      Author(s): Nicolas De Cock, Mathieu Massinon, Sofiene O.T. Salah, Frédéric Lebeau
      In crop protection, it is well known that droplet size determine spray efficacy. The optimisation of both spray deposition and retention leads to a dilemma: should small droplets be used to increase retention or large droplets be preferred to avoid drift' An ideal droplet should have a short time of flight to minimise its distance travelled while impacting the target with a moderate kinetic energy. This paper aims to determine an optimum range of droplet sizes for boom-sprayer applying herbicide using a modelling approach. The main parameters of spray deposition and retention models are systematically varied and the effects on drift potential and droplet impaction outcomes are discussed. The results of the numerical simulations showed that droplets with diameter ranging between 200 μm and 250 μm offer high control of deposition by combining a low drift potential and a moderate kinetic energy at top of the canopy. A fourfold reduction of the volume drifting further than 2 m from the nozzle was observed for a spray with a volume median diameter of 225 μm when the relative span factor of the droplet spectrum was reduced from 1.0 to 0.6. In the latter scenario, an increase from 63 to 67% of the volumetric proportion of droplets adhering to the wheat leaf was observed. Therefore, strategies for controlling the droplet size distribution may offer promising solutions for reducing adverse impact of spray applications on environment.

      PubDate: 2017-09-02T09:05:30Z
      DOI: 10.1016/j.biosystemseng.2017.08.001
      Issue No: Vol. 162 (2017)
       
  • Integration of simultaneous tactile sensing and visible and near-infrared
           reflectance spectroscopy in a robot gripper for mango quality assessment
    • Authors: Victoria Cortés; Carlos Blanes; José Blasco; Coral Ortíz; Nuria Aleixos; Martín Mellado; Sergio Cubero; Pau Talens
      Pages: 112 - 123
      Abstract: Publication date: October 2017
      Source:Biosystems Engineering, Volume 162
      Author(s): Victoria Cortés, Carlos Blanes, José Blasco, Coral Ortíz, Nuria Aleixos, Martín Mellado, Sergio Cubero, Pau Talens
      Development of non-destructive tools for determining mango ripeness would improve the quality of industrial production of the postharvest processes. This study addresses the creation of a new sensor that combines the capability of obtaining mechanical and optical properties of the fruit simultaneously. It has been integrated into a robot gripper that can handle the fruit obtaining non-destructive measurements of firmness, incorporating two spectrometer probes to simultaneously obtain reflectance properties in the visible and near-infrared, and two accelerometers attached to the rear side of two fingers. Partial least square regression was applied to different combinations of the spectral data obtained from the different sensors to determine the combination that provides the best results. Best prediction of ripening index was achieved using both spectral measurements and two finger accelerometer signals, with R P 2 = 0.832 and RMSEP of 0.520. These results demonstrate that simultaneous measurement and analysis of the data fusion set improve the robot gripper features, allowing assessment of the quality of the mangoes during pick and place operations.

      PubDate: 2017-09-02T09:05:30Z
      DOI: 10.1016/j.biosystemseng.2017.08.005
      Issue No: Vol. 162 (2017)
       
  • Terrain assessment for precision agriculture using vehicle dynamic
           modelling
    • Authors: Giulio Reina; Annalisa Milella; Rocco Galati
      Pages: 124 - 139
      Abstract: Publication date: October 2017
      Source:Biosystems Engineering, Volume 162
      Author(s): Giulio Reina, Annalisa Milella, Rocco Galati
      Advances in precision agriculture greatly rely on innovative control and sensing technologies that allow service units to increase their level of driving automation while ensuring at the same time high safety standards. This paper deals with automatic terrain estimation and classification that is performed simultaneously by an agricultural vehicle during normal operations. Vehicle mobility and safety, and the successful implementation of important agricultural tasks including seeding, ploughing, fertilising and controlled traffic depend or can be improved by a correct identification of the terrain that is traversed. The novelty of this research lies in that terrain estimation is performed by using not only traditional appearance-based features, that is colour and geometric properties, but also contact-based features, that is measuring physics-based dynamic effects that govern the vehicle–terrain interaction and that greatly affect its mobility. Experimental results obtained from an all-terrain vehicle operating on different surfaces are presented to validate the system in the field. It was shown that a terrain classifier trained with contact features was able to achieve a correct prediction rate of 85.1%, which is comparable or better than that obtained with approaches using traditional feature sets. To further improve the classification performance, all feature sets were merged in an augmented feature space, reaching, for these tests, 89.1% of correct predictions.

      PubDate: 2017-09-02T09:05:30Z
      DOI: 10.1016/j.biosystemseng.2017.06.025
      Issue No: Vol. 162 (2017)
       
  • Identification of beef cattle categories (cows and calves) and sex based
           on the near infrared reflectance spectroscopy of their tail hair
    • Authors: Christopher J. O'Neill; Jessica J. Roberts; Daniel Cozzolino
      Pages: 140 - 146
      Abstract: Publication date: October 2017
      Source:Biosystems Engineering, Volume 162
      Author(s): Christopher J. O'Neill, Jessica J. Roberts, Daniel Cozzolino
      Near infrared (NIR) reflectance spectroscopy combined with chemometrics was used to classify tail hair samples from animals of the same breed of cattle (Brahman) into cow or calf and into male or female animals. Tail hair samples (n = 74) were scanned in the NIR region (680–2500 nm) using a fibre optic probe attached to an instrument operating in reflectance mode. Principal component analysis (PCA), and partial least squares discriminant analysis (PLS-DA) were then used to classify the samples according to their origin or sex. Full cross validation (leave-one-out) was used as the validation method when classification models were developed. Correct classification rates of 92% for cow and 100% for calf samples were obtained using PLS-DA. These results demonstrated the ability of NIR spectroscopy to discriminate between the animal categories and sex of animals. Further studies will be carried out to validate the methodology in various categories of beef cattle.

      PubDate: 2017-09-02T09:05:30Z
      DOI: 10.1016/j.biosystemseng.2017.07.007
      Issue No: Vol. 162 (2017)
       
  • 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)
       
  • Model for the prediction of grain density and pressure distribution in
           hopper-bottom silos
    • Authors: Xuduo Cheng; Qiang Zhang Cuixia Shi Xiaojie Yan
      Abstract: Publication date: November 2017
      Source:Biosystems Engineering, Volume 163
      Author(s): Xuduo Cheng, Qiang Zhang, Cuixia Shi, Xiaojie Yan
      A model was developed to predict the grain density, pressure distribution and grain mass in hopper-bottom silos. The model consisted of a series of differential equations derived from the force equilibrium on a differential element of grain in the silo. These differential equations govern the relationship between the variable grain density and the stresses in the grain mass. An oedometer was used to measure the bulk density of wheat under various pressure levels. Based on the experimental data, a quadratic equation was proposed to model the relationship between the grain density and the maximum principal stress. The model predicted that grain density, and vertical and lateral pressures in the grain mass increased with the grain depth in the cylindrical portion of the hopper-bottom silo, but decreased with the depth in the hopper. The lateral pressure predicted by the model was greater than that calculated by the Janssen equation for the cylindrical section of the silo. The model predictions of grain mass in silos were compared with the measured values from commercial grain silos at two locations, and differences were found to be less than 1.45%.

      PubDate: 2017-10-11T05:14:26Z
       
  • Random field theory to interpret the spatial variability of lacustrine
           soils
    • Authors: Giovanna Vessia; Savino Russo
      Abstract: Publication date: Available online 27 September 2017
      Source:Biosystems Engineering
      Author(s): Giovanna Vessia, Savino Russo
      The mechanical characterisation of heterogeneous soils, such as alluvial deposits, is commonly performed through a deterministic approach. This latter consists on applying the engineering judgment to choose a mean trend from continuous vertical readings of in field investigations (e.g. Cone Penetration Tests – CPTs) or discontinuous ones as Standard Penetration Tests (SPTs). Conversely, in order to take into account the spatial variability of mechanical measurements of the soil the spatial standard deviation, the scale of fluctuation and the autocorrelation function have to be calculated. This latter approach follows the stochastic field theory and it can be fruitfully applied to all those soil formations that are inherently heterogeneous. In this paper, theoretical bases of this approach has been briefly described and a practical application to lacustrine soil deposits at Popoli site located in Abruzzi Region (Italy) are presented. The methods introduced are not straightforward but they provide information that can be used to improve both the reliability of the geotechnical design and the efficiency of the soil use depending on the investigated depths and the measurement intervals.

      PubDate: 2017-10-04T03:43:58Z
      DOI: 10.1016/j.biosystemseng.2017.08.023
       
  • Dormant stem water potential responds to laboratory manipulation of
           hydration as well as contrasting rainfall field conditions in deciduous
           tree crops
    • Authors: Luke K. Milliron; Andres Olivos; Sebastian Saa; Blake L. Sanden; Ken A. Shackel
      Abstract: Publication date: Available online 22 September 2017
      Source:Biosystems Engineering
      Author(s): Luke K. Milliron, Andres Olivos, Sebastian Saa, Blake L. Sanden, Ken A. Shackel
      Pressure chamber measurement of midday stem water potential (SWP) during the growing season has become a practical and widely adopted tool for irrigation management in many woody perennial and some annual crops, but this technique has not been applied to perennial crops during dormancy. The reliability of SWP measurements in dormant trees has in fact been questioned based on concerns that these tissues typically have a low percent of living tissue and/or a high level of embolism. Accurate psychrometer measurements of water potential do not depend on either of these properties, and hence should be useful in evaluating the accuracy of pressure chamber measured SWP in dormant trees. Pressure chamber and in-situ stem psychrometer methods were compared on dormant branches exposed to different levels of hydration in the laboratory. A very highly significant (Pr < 0.0001) linear regression was found between the two methods over a wide range of SWP (0 to about −2 MPa) in almond, cherry, and walnut, with r-square values ranging from 0.90 to 0.98. For almond and cherry, the slope of the regression was close to unity. Field measurements showed systematically lower SWP during a dry winter compared to a wet winter, and SWP was found to increase in response to a winter irrigation. This evidence strongly supports the validity of pressure chamber measured SWP as a reliable indicator of dormant tree water status, and hence its use as a tool to evaluate the need for winter irrigation in dormant tree crops.

      PubDate: 2017-09-26T02:38:36Z
      DOI: 10.1016/j.biosystemseng.2017.09.001
       
  • Image analysis to refine measurements of dairy cow behaviour from a
           real-time location system
    • Authors: Bruno Meunier; Philippe Pradel; Karen H. Sloth; Carole Cirié; Eric Delval; Marie M. Mialon; Isabelle Veissier
      Abstract: Publication date: Available online 20 September 2017
      Source:Biosystems Engineering
      Author(s): Bruno Meunier, Philippe Pradel, Karen H. Sloth, Carole Cirié, Eric Delval, Marie M. Mialon, Isabelle Veissier
      Long-term monitoring of animal activity can yield key information for both researchers in ethology and engineers in charge of developing precision livestock farming tools. First, a barn is segmented into delimited areas (e.g. cubicles) with which an activity can be associated (e.g. resting), then a real-time location system (RTLS) can be used to automatically convert cow position into behaviour. Working within the EU-PLF project, we tested a system already able to determine basic activities (resting, moving, eating…) and logged a “big data” set of billions of data points (123 days × 190 cows × 1 location-per-second readings). We then focused on integrating image analysis techniques to help visualise and analyse the dataset, first to validate the data and then to enrich the information extracted. The algorithm developed using freely available tools quickly confirmed the ability of the system to determine cows' main activities (except drinking behaviour), even with 11% of positions missing. The good localisation precision (16 cm) made it possible to enrich the time-budget with new activities such as using brushes and licking mineral blocks. For both activities, using visual observations as gold standard, activity profiles with excellent sensitivity (nearly 80%) were extracted. This validation procedure is both necessary and generalisable to other situations. The improvement of biological information contained in such data holds promise for people designing alarm devices and health and welfare indicators for farmers and/or vets.
      Graphical abstract image

      PubDate: 2017-09-26T02:38:36Z
      DOI: 10.1016/j.biosystemseng.2017.08.019
       
  • Leaf water content estimation by functional linear regression of field
           spectroscopy data
    • Authors: José R. Rodríguez-Pérez; Celestino Ordóñez; Ana B. González-Fernández; Enoc Sanz-Ablanedo; José B. Valenciano; Victoriano Marcelo
      Abstract: Publication date: Available online 19 September 2017
      Source:Biosystems Engineering
      Author(s): José R. Rodríguez-Pérez, Celestino Ordóñez, Ana B. González-Fernández, Enoc Sanz-Ablanedo, José B. Valenciano, Victoriano Marcelo
      Grapevine water status is critical as it affects fruit quality and yield. We assessed the potential of field hyperspectral data in estimating leaf water content (C w) (expressed as equivalent water thickness) in four commercial vineyards of Vitis vinifera L. reflecting four grape varieties (Mencía, Cabernet Sauvignon, Merlot and Tempranillo). Two regression models were evaluated and compared: ordinary least squares regression (OLSR) and functional linear regression (FLR). OLSR was used to fit C w and vegetation indices, whereas FLR considered reflectance in four spectral ranges centred at the 960, 1190, 1465 and 2035 nm wavelengths. The best parameters for the FLR model were determined using cross-validation. Both models were compared using the coefficient of determination (R 2) and percentage root mean squared error (%RMSE). FLR using continuous stretches of the spectrum as input produced more suitable C w models than the vegetation indices, considering both the fit and degree of adjustment and the interpretation of the model. The best model was obtained using FLR in the range centred at 1465 nm (R 2 = 0.70 and %RMSE = 8.485). The results depended on grape variety but also suggested that leaf C w can be predicted on the basis of spectral signature.

      PubDate: 2017-09-20T02:23:47Z
      DOI: 10.1016/j.biosystemseng.2017.08.017
       
  • Corrigendum to “Machine vision system for the automatic segmentation of
           plants under different lighting conditions” [Biosyst Eng 161, September
           2017, 157–173]
    • Authors: Sajad Sabzi; Yousef Abbaspour-Gilandeh; Hossein Javadikia
      Abstract: Publication date: Available online 18 September 2017
      Source:Biosystems Engineering
      Author(s): Sajad Sabzi, Yousef Abbaspour-Gilandeh, Hossein Javadikia


      PubDate: 2017-09-20T02:23:47Z
      DOI: 10.1016/j.biosystemseng.2017.09.003
       
  • Implementation of an automatic 3D vision monitor for dairy cow locomotion
           in a commercial farm
    • Authors: Tom Van Hertem; Andrés Schlageter Tello; Stefano Viazzi; Machteld Steensels; Claudia Bahr; Carlos Eduardo Bites Romanini; Kees Lokhorst; Ephraim Maltz; Ilan Halachmi; Daniel Berckmans
      Abstract: Publication date: Available online 9 September 2017
      Source:Biosystems Engineering
      Author(s): Tom Van Hertem, Andrés Schlageter Tello, Stefano Viazzi, Machteld Steensels, Claudia Bahr, Carlos Eduardo Bites Romanini, Kees Lokhorst, Ephraim Maltz, Ilan Halachmi, Daniel Berckmans
      The objective of this study was to evaluate the system performance of a 3D vision system for automatic locomotion monitoring implemented in a commercial dairy farm. Data were gathered during 633 milking sessions on a Belgian commercial dairy farm. After milking, the cows walked in a single-lane alley where the video recording system with a 3D depth camera was installed. The entire monitoring process including video recording, video pre-processing by filtering, cow identification and video analysis was automated. Image processing extracted six feature variables from the recorded videos. Per milking session, 224 ± 10 cows (100%) were identified on average by a radio-frequency identification (RFID) antenna, and 197 ± 16 videos were recorded (88.1 ± 6.6%) by the camera. The cow identification number was merged automatically to a recorded video in 178 ± 14 videos (79.4 ± 5.5%). After video pre-processing and analysis, 110 ± 24 recorded cow-videos (49.3 ± 10.8%) per session resulted in an automatic locomotion score. Daily and cow-individual variations on the merging and analysis rate were due to cow traffic. The minimal cow traffic interval required between consecutive cows was 15 s for optimal merging. System performance was affected by lactation stage, parity of the cows and recording duration. The feature variables curvature angle of back around hip joints (Area Under the Receiver Operating Characteristics Curve (AUC) = 0.719) and back posture measurement (AUC = 0.702) could be considered as fair lameness classifiers. Cow traffic affected the success rate of the video processing. Therefore, automatic monitoring systems need to be adapted to the farm layout.

      PubDate: 2017-09-14T01:05:51Z
      DOI: 10.1016/j.biosystemseng.2017.08.011
       
  • Online warning systems for individual fattening pigs based on their
           feeding pattern
    • Authors: Jarissa Maselyne; Annelies Van Nuffel; Petra Briene; Jürgen Vangeyte; Bart De Ketelaere; Sam Millet; Janne Van den Hof; Dominiek Maes; Wouter Saeys
      Abstract: Publication date: Available online 4 September 2017
      Source:Biosystems Engineering
      Author(s): Jarissa Maselyne, Annelies Van Nuffel, Petra Briene, Jürgen Vangeyte, Bart De Ketelaere, Sam Millet, Janne Van den Hof, Dominiek Maes, Wouter Saeys
      For sustainable pork production and maximum pig welfare, all health, welfare and productivity problems in the barn should be detected as early as possible. In this paper, an automated monitoring and warning system is proposed. Based on measurements of the feeding pattern, it is able to generate daily alerts for individual fattening pigs. Using historical data, the following types of warning systems were developed: (1) fixed limits that treat all pigs and all days equally; and (2) time-varying individual limits using the concept of Synergistic Control. These types of limits were constructed either for the number of registrations per pig or the average interval between feeding visits of a pig, leading to four warning systems in total. These warning systems were used to generate alerts during an online validation period. During an entire fattening period, all pigs were individually monitored to establish true alerts, false alerts and missed problems. The best performance was achieved for the Synergistic Control method on the number of registrations, with a sensitivity of 58.0%, specificity of 98.7%, accuracy of 96.7% and precision of 71.1%. Severe problems were detected on average within 1.3 days from the start of the problem. These are promising results that provide a solid basis for the development of a system for individual pigs but further improvements are warranted to make the system more practical.

      PubDate: 2017-09-08T09:15:21Z
      DOI: 10.1016/j.biosystemseng.2017.08.006
       
  • Linking thermal imaging and soil remote sensing to enhance irrigation
           management of sugar beet
    • Authors: Quebrajo Perez-Ruiz; Egea
      Abstract: Publication date: Available online 2 September 2017
      Source:Biosystems Engineering
      Author(s): L. Quebrajo, M. Perez-Ruiz, L. Pérez-Urrestarazu, G. Martínez, G. Egea
      The use of reliable information and data that are rapidly and easily acquired is essential for farm water management and appropriate irrigation strategies. Over the past decade, new advances have been made in irrigation technology, such as platforms that continuously transmit data between irrigation controllers and field sensors, mobile apps, and equipment for variable rate irrigation. In this study, images captured with a thermal imaging camera mounted on an unmanned aerial vehicle (UAV) were used to evaluate the water status of sugar beet plants in a plot with large spatial variability in terms of soil properties. The results were compared with those of soil moisture measurements. No direct relationship was observed between the water status of the soil and that of the crops. However, the fresh root mass and sugar content tended to decrease when higher levels of water stress were detected in the crop using thermal imaging, with coefficients of determination of 0.28 and 0.94 for fresh root mass and sugar content, respectively. Differences were observed between different soil types, and therefore different irrigation strategies are needed in highly heterogeneous plots.

      PubDate: 2017-09-08T09:15:21Z
       
 
 
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