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  Subjects -> AGRICULTURE (Total: 672 journals)
    - AGRICULTURAL ECONOMICS (73 journals)
    - AGRICULTURE (450 journals)
    - CROP PRODUCTION AND SOIL (88 journals)
    - DAIRYING AND DAIRY PRODUCTS (25 journals)
    - POULTRY AND LIVESTOCK (36 journals)

AGRICULTURE (450 journals)                  1 2 3 4 5 | Last

Aceh International Journal of Science and Technology     Open Access  
Acta agriculturae Slovenica     Open Access   (Followers: 5)
Acta Agrobotanica     Open Access   (Followers: 3)
Acta Agronomica Hungarica     Full-text available via subscription   (Followers: 1)
Acta Agronomica Sinica     Full-text available via subscription   (Followers: 6)
Acta Scientiarum. Animal Sciences     Open Access   (Followers: 1)
Acta Scientiarum. Technology     Open Access   (Followers: 1)
Acta Technologica Agriculturae     Open Access   (Followers: 3)
Advances in Agriculture & Botanics     Open Access   (Followers: 10)
Advances in Agriculture, Sciences and Engineering Research     Open Access   (Followers: 11)
Advances in Agronomy     Full-text available via subscription   (Followers: 11)
Advances in Life Science and Technology     Open Access   (Followers: 6)
AFBM Journal     Open Access  
Africa Development     Open Access   (Followers: 8)
Africa Research Bulletin: Political, Social and Cultural Series     Hybrid Journal   (Followers: 8)
African Journal of Agricultural Research     Open Access   (Followers: 3)
African Journal of Food Science     Open Access   (Followers: 3)
African Journal of Food, Agriculture, Nutrition and Development     Open Access   (Followers: 4)
African Journal of Horticultural Science     Open Access   (Followers: 2)
African Journal of Range and Forage Science     Hybrid Journal   (Followers: 5)
African Journal of Sustainable Development     Full-text available via subscription   (Followers: 5)
Agribusiness : an International Journal     Hybrid Journal   (Followers: 5)
Agricultura Tecnica     Open Access   (Followers: 6)
Agricultura Tropica et Subtropica     Open Access   (Followers: 2)
Agricultural Advances     Open Access   (Followers: 4)
Agricultural and Food Science     Open Access   (Followers: 18)
Agricultural Economics     Hybrid Journal   (Followers: 45)
Agricultural History     Full-text available via subscription   (Followers: 200)
Agricultural Research     Hybrid Journal   (Followers: 4)
Agricultural Science     Full-text available via subscription   (Followers: 6)
Agricultural Sciences     Open Access   (Followers: 8)
Agricultural Sciences in China     Full-text available via subscription   (Followers: 4)
Agricultural Systems     Hybrid Journal   (Followers: 21)
Agricultural Water Management     Hybrid Journal   (Followers: 15)
Agriculture     Open Access   (Followers: 5)
Agriculture & Food Security     Open Access   (Followers: 11)
Agriculture (Poľnohospodárstvo)     Open Access   (Followers: 1)
Agriculture and Agricultural Science Procedia     Full-text available via subscription   (Followers: 1)
Agriculture and Human Values     Hybrid Journal   (Followers: 11)
Agriculture, Ecosystems & Environment     Hybrid Journal   (Followers: 31)
Agriprobe     Full-text available via subscription  
Agrivita : Journal of Agricultural Science     Open Access   (Followers: 4)
Agro-Science     Full-text available via subscription  
Agroalimentaria     Open Access   (Followers: 1)
Agrociencia     Open Access   (Followers: 2)
Agrokémia és Talajtan     Full-text available via subscription   (Followers: 2)
Agronomía Colombiana     Open Access   (Followers: 1)
Agronomía Costarricense     Open Access   (Followers: 2)
Agronomía Mesoamericana     Open Access   (Followers: 1)
Agronomie Africaine     Full-text available via subscription  
Agronomy     Open Access   (Followers: 8)
Agrosearch     Open Access  
AI & Society     Hybrid Journal   (Followers: 2)
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: 9)
American Journal of Botany     Full-text available via subscription   (Followers: 14)
American Journal of Economics and Sociology     Hybrid Journal   (Followers: 19)
American Journal of Potato Research     Hybrid Journal   (Followers: 2)
Anais da Academia Brasileira de Ciências     Open Access   (Followers: 2)
Annales UMCS, Agricultura     Open Access  
Annales UMCS, Horticultura     Full-text available via subscription  
Annals of Agricultural and Environmental Medicine     Open Access   (Followers: 1)
Annals of Agricultural Sciences     Open Access   (Followers: 1)
Annual Review of Resource Economics     Full-text available via subscription   (Followers: 10)
APCBEE Procedia     Partially Free   (Followers: 2)
Applied Economics Letters     Hybrid Journal   (Followers: 19)
Applied Financial Economics Letters     Hybrid Journal   (Followers: 6)
Arboricultural Journal : The International Journal of Urban Forestry     Hybrid Journal   (Followers: 6)
Archivos de Zootecnia     Open Access   (Followers: 2)
Arquivos do Instituto Biológico     Open Access  
Arthropod-Plant Interactions     Hybrid Journal   (Followers: 1)
Asian Economic Papers     Hybrid Journal   (Followers: 3)
Asian Journal of Agricultural Research     Open Access   (Followers: 4)
Asian Journal of Plant Sciences     Open Access   (Followers: 2)
Australian Cottongrower, The     Full-text available via subscription   (Followers: 1)
Australian Economic Papers     Hybrid Journal   (Followers: 5)
Australian Forest Grower     Full-text available via subscription   (Followers: 2)
Australian Forestry     Full-text available via subscription   (Followers: 4)
Australian Grain     Full-text available via subscription   (Followers: 4)
Australian Holstein Journal     Full-text available via subscription  
Australian Journal of Agricultural and Resource Economics     Hybrid Journal   (Followers: 5)
Australian Journal of Agricultural Engineering     Open Access  
Australian Sugarcane     Full-text available via subscription  
Avances en Investigacion Agropecuaria     Open Access   (Followers: 1)
Bangladesh Journal of Agricultural Research     Open Access   (Followers: 2)
Bangladesh Journal of Scientific Research     Open Access   (Followers: 1)
Berkala Ilmiah Pertanian     Open Access   (Followers: 1)
Bioagro     Open Access   (Followers: 1)
Biocatalysis and Agricultural Biotechnology     Hybrid Journal   (Followers: 5)
Biocontrol Science and Technology     Hybrid Journal   (Followers: 5)
Biodiversity     Hybrid Journal   (Followers: 19)
Biodiversity : Research and Conservation     Open Access   (Followers: 17)
Biological Agriculture & Horticulture : An International Journal for Sustainable Production Systems     Partially Free   (Followers: 13)
Biosystems Engineering     Hybrid Journal   (Followers: 1)
Biotemas     Open Access  
Bragantia     Open Access   (Followers: 2)
Brazilian Archives of Biology and Technology     Open Access   (Followers: 1)
British Poultry Science     Hybrid Journal   (Followers: 7)

        1 2 3 4 5 | Last

Journal Cover Biosystems Engineering
   Journal TOC RSS feeds Export to Zotero [3 followers]  Follow    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
     ISSN (Print) 1537-5110 - ISSN (Online) 1537-5129
     Published by Elsevier Homepage  [2570 journals]   [SJR: 0.757]   [H-I: 58]
  • Cooling systems in screenhouses: Effect on microclimate, productivity and
           plant response in a tomato crop
    • Abstract: Publication date: January 2015
      Source:Biosystems Engineering, Volume 129
      Author(s): R. Leyva , C. Constán-Aguilar , E. Sánchez-Rodríguez , M. Romero-Gámez , T. Soriano
      Mediterranean climates are characterised by summer temperatures that exceed 35 °C, high solar radiation ∼ 30 MJ m−2, relative humidity < 20% at around midday, and limited water resources generating yield loss in crops. For this reason, new climate strategy for greenhouses used in Mediterranean climates has been developed to avoid plant injury. Cherry tomato plants were assessed during 2010 and 2011 under different environmental conditions, namely in a screenhouse (S), in a screenhouse equipped with a fogging system (SF) and in a screenhouse with a plastic sheeting to maintain the microclimate created by the fogging system (SFS). SFS improved microclimatic conditions during the 2010 and 2011 growing seasons by, reducing incident radiation 37% and 30%, respectively while increasing relative humidity by 20% and 16%, respectively and respect to S lowering the vapour pressure deficit. These adjustments in microclimate could moderate the extremes of microclimate during the summer, avoiding episodes of physiological stress that affect yield and final quality. The dry mass vegetables plants parts grown under SFS increased while the marketable mass per plant was not significantly different. This was due to 45% increased in mean tomato fruit mass in 2010 and by 20% in 2011. Although tomato leaves grown under SFS registered the lowest values in foliar temperature, they showed the highest values for LAI, SLA, and LAR. It was concluded that a fogging could improve the climatic conditions under screenhouse and extend the growing season during adverse environmental conditions.


      PubDate: 2014-10-21T04:05:04Z
       
  • Parametric evaluation using mechanistic model for release rate of
           phosphate ions from chitosan-coated phosphorus fertiliser pellets
    • Abstract: Publication date: January 2015
      Source:Biosystems Engineering, Volume 129
      Author(s): N.N.R. Ahmad , W.J.N. Fernando , M.H. Uzir
      Evaluation of nutrient release from a controlled-release fertiliser (CRF) using mechanistic model is important in order to increase the understanding towards the mechanism that might involve in a release process. In this study, a mechanistic model was used to evaluate the parameters that govern the phosphate release rate through chitosan-coated phosphorus fertiliser. The model considers the phenomena of boundary layer formation on the external surface of the coat and the coating thickness changes due to erosion. Static release experiments were conducted in order to study the effect of the number of coatings and pH conditions to the release rate of phosphate ions. The respective parameters of the phosphate release such as diffusion coefficient were evaluated using the model in both cases. The diffusivity of the phosphate was found to increase as the number of coatings and pH values of the medium decreased. Regeneration of the released data for the phosphate ions using the model indicated a very satisfactory fit with the experimental data.


      PubDate: 2014-10-21T04:05:04Z
       
  • Mechanical analysis of the bending behaviour of plant stems
    • Abstract: Publication date: January 2015
      Source:Biosystems Engineering, Volume 129
      Author(s): Tom Leblicq , Simon Vanmaercke , Herman Ramon , Wouter Saeys
      In order to optimise the processing of stem crops, insight into the deformation behaviour of the crop and the interaction between crop and machine is essential. Most research in the area of mechanical and physical properties of crop stems is focused on characterising the agricultural products to the point of failure using mechanical parameters and empirical relations. No studies have been conducted on the processes which lead to failure of stems and on the processes that take place after failure. In this paper it is shown that the bending behaviour of wheat and barley stalks is very similar to that of steel tubes. Two consecutive phases can be distinguished: ovalisation and buckling. During ovalisation the forces on the wall tend to flatten the cross-section. When this process continues the flexural stiffness is reduced until the structure becomes unstable and buckles. The cross-section locally completely flattens. This deformed cross-section offers virtually no resistance to bending. Mechanical models described in literature have successfully been adapted to describe the bending behaviour of crop stalks during both phases ( R 2 > 0.98 for ovalisation and R 2 > 0.97 for buckling). The crop species, growing conditions, stem diameter and wall thickness were found to influence the bending process significantly. The presence of a core-rind structure increases the bending resistance of the stems.


      PubDate: 2014-10-21T04:05:04Z
       
  • Determining total solids and fat content of liquid whole egg products via
           measurement of electrical parameters based on the transformer properties
    • Abstract: Publication date: January 2015
      Source:Biosystems Engineering, Volume 129
      Author(s): Yamei Jin , Na Yang , Xiang Duan , Fengfeng Wu , Qunyi Tong , Xueming Xu
      A method for determining the total solids and fat content of liquid whole egg products based on the principle of transformer was developed. The electrical parameters (terminal voltage and λ value) in the secondary circuit, where the sample acted as the coil, were investigated under the action of alternating magnetic flux in the frequency range from 60 to 400 Hz. Findings indicated that subtle changes of quality indices could be detected by electrical parameters based on the transformer properties that relate to the amount of free ions in the samples. As the inductive voltage was fixed, terminal voltage was negatively correlated with quality indices of total solids and fat content. Therefore the decrement of impedance in the secondary circuit caused the increment of inductive current according to Ohm's law. Linear prediction models for the aforementioned quality indices based on these electrical parameters were also established. Judging from coefficients of determination (R 2) and the root mean square error of prediction (RMSEP) of these models, the λ value was found to be a better predictor for quality indices of liquid whole egg products than terminal voltage. It is believed that this method has the potential to evaluate the quality of liquid food materials over a wider frequency and temperature range.


      PubDate: 2014-10-16T03:37:25Z
       
  • Design and analysis of the response of elastically supported wind-break
           panels of two different permeabilities under wind load
    • Abstract: Publication date: January 2015
      Source:Biosystems Engineering, Volume 129
      Author(s): Anastasios Giannoulis , Antonios Mistriotis , Demetrios Briassoulis
      The design and response of elastically supported short-length windbreak panels of different permeabilities under wind load is presented. The response of the panels was investigated through full-scale experiments and numerical simulation analysis. Two cladding materials were used: an impermeable film and a permeable net (62% porosity ratio). For the field experiments the elastic support of the panel was achieved by using extension springs which allowed it to pivot in response to wind loading through a hinge support at its base. The wind pressures developed on the panel for various equilibrium positions reached under different wind velocities were measured. The elastic support response resulted in a significant reduction of the wind pressures and the stress resultants on the windbreak for both cladding materials. A combined model coupling two-dimensional computational fluid dynamic simulation and non-linear structural analysis was used to analyse the behaviour of the elastically supported panel when interacting with the wind. The numerical results for the elastic support response under wind load, and the developed wind pressures, were found to agree with the full-scale experiments for both cladding cases. For the permeable cladding case, the wake flow of the elastically supported panel was shown to be free of large scale turbulent eddies when analysed by numerical simulations. The wake airflow for the impermeable panel case was found to be complex and extensive investigation is required.


      PubDate: 2014-10-12T03:10:13Z
       
  • Simulation and prediction of radio frequency heating in dry soybeans
    • Abstract: Publication date: January 2015
      Source:Biosystems Engineering, Volume 129
      Author(s): Zhi Huang , Hankun Zhu , Rongjun Yan , Shaojin Wang
      Radio frequency (RF) heating is considered as a potential postharvest technology for disinfesting legumes. However, the non-uniformity in RF heating is still a major problem in developing effective RF heat treatments for pest control and other applications. A computer simulation model was developed with a finite element-based commercial software, COMSOL, to analyse the temperature distributions. Dry soybeans packed in a rectangular plastic container were used to determine the heating uniformity and validate the simulation model using a 27.12 MHz, 6 kW RF system. Both simulated and experimental results showed similar heating patterns in RF treated soybeans, in which corners and edges were more heated and the temperature values were higher in the lower part of the container. The simulation results demonstrated that the RF heating uniformity could be improved using a similar dielectric material around the samples, a smaller top plate area (similar to the sample size), and placing the samples in the middle of the two plate electrodes. The simulation model developed in this study could be applied to improve the RF heating uniformity and to optimise the treatment parameters.


      PubDate: 2014-10-12T03:10:13Z
       
  • The effects of storage time and temperature on biogas production from
           dairy cow slurry
    • Abstract: Publication date: January 2015
      Source:Biosystems Engineering, Volume 129
      Author(s): James D. Browne , Stephen R. Gilkinson , John P. Frost
      The effects of length of storage time and storage temperature on subsequent biogas production from dairy cow slurry by anaerobic digestion were investigated. Slurry was stored under anaerobic conditions at 9 °C and 20 °C for between 1 and 26 weeks prior to digestion. Digestion was carried out in 7 l continuously stirred tank reactors, with an average hydraulic retention time of 25 d. Storage of slurry at 9 °C had no significant effect on subsequent biogas production. However, after 8 weeks of storage at 20 °C there was an increasing negative impact on subsequent biogas production so that after 26 weeks of storage at 20 °C biogas production had decreased from 16.4 m3 t−1 to 5 m3 t−1 of fresh slurry. This reduction was strongly related to the decrease in the concentration of volatile solids in the stored slurry which was approximately 0.4 g kg−1 week−1. Storage time and temperature had no affect on the total nitrogen concentrations in the slurries, though both factors resulted in small increases in ammonia nitrogen concentrations.


      PubDate: 2014-10-12T03:10:13Z
       
  • Climate change, effective water use for irrigation and adaptability of
           maize: A case study in southern Italy
    • Abstract: Publication date: Available online 3 October 2014
      Source:Biosystems Engineering
      Author(s): Eugenia Monaco , Antonello Bonfante , Silvia M. Alfieri , Angelo Basile , Massimo Menenti , Francesca De Lorenzi
      Climate change may lead to differences in the distribution of precipitation and to reduced water availability, with constraints on the cultivation of some crops. An analysis of vulnerability and of opportunities for adaptation is required for crops in areas where they are currently cultivated. The intra-specific biodiversity of crops is a significant resource for the adaptation of agriculture, but requires better knowledge of the responses of cultivars to environmental stressors. Simulation models of water flow in the soil-plant-atmosphere system can be coupled with future climate scenarios to describe the soil water regime, taking into account different irrigation scheduling options. The adaptive capacity of maize hybrids is evaluated in an irrigated district in Southern Italy. Two climate cases were studied: “reference” (1961–1990) and “future” (2021–2050). The model SWAP was run to determine the soil water balance for different irrigation levels. For each level the effectiveness of irrigation was evaluated by means of a performance indicator (IE). The Relative Evapotranspiration Deficit (RETD) was used as an indicator of water availability. The yield response to water availability of several maize hybrids was determined; their hydrologic requirements were thus defined and compared with the simulated values of RETD in response to climate and irrigation. Soil moisture regime and irrigation performance were also analysed. The adaptability of hybrids to the future water regime was assessed for different irrigation levels. The study indicated how, in the future climate case, the intra-specific crop biodiversity, in combination with cropping patterns better adapted to soil characteristics, may allow the current production system to be maintained.


      PubDate: 2014-10-08T02:43:52Z
       
  • A method of optimal traction control for farm tractors with feedback of
           drive torque
    • Abstract: Publication date: January 2015
      Source:Biosystems Engineering, Volume 129
      Author(s): Pavel V. Osinenko , Mike Geissler , Thomas Herlitzius
      Traction efficiency of farm tractors barely reaches 50% in field operations (Renius et al., 1985). On the other hand, modern trends in agriculture show growth of the global tractor markets and at the same time increased demands for greenhouse gas emission reduction as well as energy efficiency due to increasing fuel costs. Engine power of farm tractors is growing at 1.8 kW per year reaching today about 500 kW for the highest traction class machines. The problem of effective use of energy has become crucial. Existing slip control approaches for farm tractors do not fulfil this requirement due to fixed reference set-point. This paper suggests an optimal control scheme which extends a conventional slip controller with set-point optimisation based on assessment of soil conditions, namely, wheel-ground parameter estimation. The optimisation considers the traction efficiency and net traction ratio and adaptively adjusts the set-point under changing soil conditions. The proposed methodology can be mainly implemented in farm tractors equipped with hydraulic or electrical infinitely variable transmissions (IVT) with use of the drive torque feedback.


      PubDate: 2014-10-08T02:43:52Z
       
  • Editorial Board
    • Abstract: Publication date: November 2014
      Source:Biosystems Engineering, Volume 127




      PubDate: 2014-10-08T02:43:52Z
       
  • Effects of mechanical distribution on survival and reproduction of
           Phytoseiulus persimilis and Amblyseius swirskii
    • Abstract: Publication date: January 2015
      Source:Biosystems Engineering, Volume 129
      Author(s): Fabio Pezzi , Roberta Martelli , Alberto Lanzoni , Stefano Maini
      The application of beneficial organisms to protected crops requires substantial manpower and obliges operators to remain for long periods in a hot and humid environment that leads to discomfort and fatigue. Mechanisation of this operation could reduce the distribution time with subsequent benefits for the health and safety of workers. A prototype distribution system for beneficial arthropods that could increase labour productivity and distribution quality on protected crops was developed. Experiments were conducted to assess the efficiency of the mechanical distribution system and its effect on the distributed organisms. Releases of the predatory mites Phytoseiulus persimilis and Amblyseius swirskii were tested in the laboratory. The release quality was verified through evaluation of distribution patterns and the effects on the viability and fecundity of both beneficial arthropods. The prototype was shown to properly perform the release without compromising the quality and biological traits of either species.


      PubDate: 2014-10-08T02:43:52Z
       
  • Prototype emitter for use in subsurface drip irrigation: Manufacturing,
           hydraulic evaluation and experimental analyses
    • Abstract: Publication date: Available online 3 October 2014
      Source:Biosystems Engineering
      Author(s): Wanderley de Jesus Souza , Leonor Rodrigues Sinobas , Raúl Sánchez , Tarlei Arriel Botrel , Rubens Duarte Coelho
      The current research aims to analyse theoretically and evaluate a self-manufactured simple design for subsurface drip irrigation (SDI) emitter to avoid root and soil intrusion. It was composed of three concentric cylindrical elements: an elastic silicone membrane; a polyethylene tube with two holes drilled on its wall for water discharge; and a vinyl polychloride protector system to wrap the other elements. The discharge of the emitter depends on the change in the membrane diameter when it is deformed by the water pressure. The study of the operation of this emitter is a new approach that considers mechanical and hydraulic principles. Thus, the estimation on the membrane deformation was based on classical mechanical stress theories in composite cylinders. The hydraulic principles considered the solid deformation due to force based on water pressure and the general Darcy–Weisbach head-loss equation. Twenty emitter units, with the selected design, were handcrafted in a lathe and were used in this study. The measured pressure/discharge relationship for the emitters showed good agreement with that calculated by the theoretical approach. The variation coefficient of the handcrafted emitters was high compared to commercial emitters. Results from field evaluations showed variable values for the relative flow variation, water emission uniformity and relative flow rate coefficients, but no emitter was obstructed. Therefore, the current emitter design could be suitable for SDI following further studies to develop a final prototype.


      PubDate: 2014-10-08T02:43:52Z
       
  • Wind pumps for irrigating greenhouse crops: Comparison in different
           socio-economical frameworks
    • Abstract: Publication date: Available online 3 October 2014
      Source:Biosystems Engineering
      Author(s): Rodrigo Díaz-Méndez , Adnan Rasheed , Manuel Peillón , Alicia Perdigones , Raúl Sánchez , Ana M. Tarquis , José L. García-Fernández
      A simple methodology was used to compare the economic feasibility of wind pump technology, solar photovoltaic pumping, diesel generators, and connection to the electrical grid to provide energy for pumping irrigation water in commercial greenhouses in Spain, Cuba and Pakistan (countries with different developmental backgrounds). The analysis took into account wind resources, distance to the grid, water storage tank volume requirements, and planting dates. Comparisons were made in terms of the levelised cost of energy associated with each system. For all three countries, if a grid connection was already in place, installing wind pumps would be economically unwise. Where no grid connection exists, the distance to the grid and the wind resource available are key factors to be taken into consideration when deciding between options: a 10% increase in the average wind speed is equivalent to a 20% reduction in the distance to the grid in terms of costs return. Finally, the water elevation has a major influence on the economic feasibility of wind pump technology, much more than, for example, on solar photovoltaic pumping technology. The results reveal that, generally, the critical factors to consider when making energy management decisions differ depending between countries. In Spain, the proximity of the electrical grid makes the connection to it the best option. In Pakistan, scarce wind resources are a serious limiting factor. Cuba, however, has good wind resources; water elevation, distance to the grid and water storage needed are the critical factors when determining the economic feasibility of wind pumping there.


      PubDate: 2014-10-08T02:43:52Z
       
  • Diurnal pattern in canopy light interception for tree fruit orchard
           trained to an upright fruiting offshoots (UFO) architecture
    • Abstract: Publication date: January 2015
      Source:Biosystems Engineering, Volume 129
      Author(s): Jingjin Zhang , Matthew D. Whiting , Qin Zhang
      Fractional interception of photosynthetically active radiation (FIPAR) (i.e. light interception) by tree fruit canopies determines, in large part, fruit quantity and quality, and thus profitability. This study aimed to elucidate the diurnal pattern in FIPAR and determine the optimum time at which the measured FIPAR best represents mean daily FIPAR in sweet cherry trees trained to the planar UFO (Upright Fruiting Offshoots) architecture. Two experiments were conducted to assess the influence of canopy development stages and of canopy height to row spacing ratios (H/S ratio) on diurnal FIPAR pattern and optimum measurement time. For different canopy development stages, three adjacent north-to-south sample blocks were selected. For different H/S ratios, three levels of 0.75, 1.00, and 1.25 were used, and 9 north-to-south sample block for each level were selected. Daily FIPAR was determined from measurements taken within ±6 h of solar noon. Gaussian process regression with four parameters was applied to obtain the diurnal pattern with coefficients of determination (R 2) ranging from 0.97 to 1.00. The diurnal pattern was symmetric with the lowest point around solar noon. Mean daily FIPAR increased during the season, as well as with increasing H/S ratio. For both experiments, there was no substantial difference in optimum measurement time among stages and among H/S ratios, with maximum difference of 0.3 h and 0.4 h respectively. We recommend an optimal measurement time window of −2.5 h to −2.0 h with reference to solar noon for the planar UFO architecture to estimate mean daily FIPAR with ±10% tolerance interval.


      PubDate: 2014-10-08T02:43:52Z
       
  • Influence of recirculation of liquid fraction of the digestate (LFD) on
           maize stover anaerobic digestion
    • Abstract: Publication date: November 2014
      Source:Biosystems Engineering, Volume 127
      Author(s): Yun Hu , Fei Shen , Hairong Yuan , Dexun Zou , Yunzhi Pang , Yanping Liu , Baoning Zhu , Wachemo Akiber Chufo , Muhammad Jaffar , Xiujin Li
      Influence of recirculation of the liquid fraction of the digestate (LFD) on anaerobic digestion of maize stover as sole substrate was investigated. Digestion without recirculation (R1) was compared with two LFD recirculation modes, direct recirculation (R2) and aerated recirculation (R3). There were no significant differences in biomethane production, biomethane yield, substance reduction rates, and pH. The biomethane yield in R1, R2, and R3 reached 73.8%, 68.2%, and 71.8% of the theoretical methane potential (TMP), respectively, and 55–60% of cellulose and hemicellulose were converted into biogas in three runs. Chemical oxygen demand (COD) and ammonia nitrogen (NH3–N) concentrations gradually increased in R2 over the whole period of digestion (360 days), but stabilised in R1 and R3 by the end of the digestion (225th−360th day). Aerated recirculation performed best in terms of COD reduction, and low NH3–N accumulation for long term operation, and therefore is recommended. The study indicated that it is technically acceptable to partially recirculate the liquid fraction for anaerobic digestion of maize stover, with the potential to reduce LFD discharge and avoid potential pollution associated with LFD.


      PubDate: 2014-10-02T02:07:07Z
       
  • A comparison of four instruments for measuring the effects of organic
           matter on the strength of compacted agricultural soils
    • Abstract: Publication date: November 2014
      Source:Biosystems Engineering, Volume 127
      Author(s): Edwin I. Ekwue , Robert A. Birch , Nicholas R. Chadee
      Soil strength estimates from shear vane, Proctor and drop cone penetrometer were obtained alongside cohesion and angle of internal friction measured with the triaxial test. Two organic materials (peat and farmyard manure) were incorporated at the rates of 0%, 4%, 8% and 12% to two soils (one sandy loam and the other clay), and compacted with 25 blows of the Proctor hammer. For the shear vane and the penetrometers, the soils were tested at moisture contents ranging from 5% to 55%, while for the triaxial tests, the soils were tested at three moisture states (5% below optimum, optimum and 5% above optimum moisture content). Although organic matter addition decreases soil strength of compacted soils at lower moisture contents, the effect decreases as moisture content increases, and there is a small increase in strength at the highest moisture contents. Organic matter decreased the strength of the soils at the three moisture states by decreasing the angle of friction rather than soil cohesion. Proctor penetrometer strength estimates were the highest followed by those from the drop cone, shear vane and the triaxial test. The shear vane overestimated the cohesion in the soil when compared with the triaxial test measurement. The penetration resistance measured with the Proctor and the drop cone penetrometers were correlated as were the shear strength measurements from the triaxial and the shear vane instrument. The Proctor penetrometer was the quickest to use, followed by the drop cone penetrometer, shear vane and the triaxial test.


      PubDate: 2014-10-02T02:07:07Z
       
  • Development of correlations for the flow of agricultural residues as
           slurries in pipes for Bio-refining
    • Abstract: Publication date: November 2014
      Source:Biosystems Engineering, Volume 127
      Author(s): Mahdi Vaezi , Amit Kumar
      Pipeline hydrotransport of agricultural residue in a carrier liquid could be an economically viable alternative to replace truck delivery of biomass materials, as well as encouraging the increase in scale of bio-refineries. The feasibility of this concept, together with friction loss behaviour and corresponding mechanisms of biomass slurry flows through pipelines, was previously studied by the authors. A 50 mm diameter, 25 m long pipeline facility was used to measure the longitudinal pressure gradient of wheat straw and corn stover slurries over a range of particle dimensions, slurry solid mass fractions, and slurry velocities. Econometric software and a nonlinear least square regression model were used to analyse the measured pressure gradients and an empirical correlation was proposed to predict slurry pressure gradients as a function of slurry specifications and operating conditions. The correlation was then modified using scale-up methods to account for the effects of pipe diameter. The pressure gradient was found to be proportional to the pipe diameter to the power of −1.2. The final correlation was able to predict the longitudinal pressure gradient of the flow of agricultural residues (i.e., non-wood fibres) as biomass slurries in pipes and, with a small uncertainty (<10%), could be applied to design commercial pipelines to hydraulically transport various agricultural residue biomass slurries. This knowledge of the slurry flow pressure gradient is essential to specify slurry pumps, determine the number of booster stations, and estimate the capital and operational costs of a slurry pipeline.


      PubDate: 2014-09-25T01:16:39Z
       
  • Mapping soil hydraulic conductivity and matric potential for water
           management of cranberry: Characterisation and spatial interpolation
           methods
    • Abstract: Publication date: Available online 24 September 2014
      Source:Biosystems Engineering
      Author(s): Silvio J. Gumiere , Jonathan A. Lafond , Dennis W. Hallema , Yann Périard , Jean Caron , Jacques Gallichand
      Spatial interpolation methods are required for analysing the effects of soil hydraulic properties on irrigation management. This study was conducted to determine which interpolation methods are best suited to map these properties. During the summer of 2012 we mapped the spatial variability of soil physical properties, soil matric potential, water table depth and yield of two cranberry fields located near Quebec City, Canada. Three spatial interpolation methods, inverse distance weighting (IDW), thin plate splines (TPS) and kriging with external drift (KED), were compared by means of cross-validation. The best interpolation method for a given property was used to produce maps and perform HYDRUS 1D simulations for the purpose of irrigation management. Results show that even in highly constructed fields, such as for cranberries, spatial patterns of soil hydraulic properties exist. The TPS method was the best interpolation method based on the cross-validation analyses and generated maps. Spatial variability of crop yield showed a strong relationship with soil hydraulic properties and simulations suggest that irrigation can be reduced by 75% when accounting for the spatial variability of soil hydraulic properties.


      PubDate: 2014-09-25T01:16:39Z
       
  • CFD simulations of the night-time condensation inside a closed glasshouse:
           Sensitivity analysis to outside external conditions, heating and glass
           properties
    • Abstract: Publication date: November 2014
      Source:Biosystems Engineering, Volume 127
      Author(s): Hacène Bouhoun Ali , Pierre-Emmanuel Bournet , Vianney Danjou , Benjamin Morille , Christophe Migeon
      Humidity and temperature are key factors in greenhouse climate management since they impact crop growth. For example, under high humidity and low temperatures, condensation may occur and lead to crop damage. In order to assess the condensation mechanism inside a closed greenhouse during the night, a closed monospan 100-m2 Venlo glasshouse was considered and 2D transient CFD simulations were conducted with particular attention paid to condensation and crop transpiration since this combination had rarely been considered before in CFD models. Radiative exchanges were included through a specific submodel and a user-defined function was activated to take account of both heat and mass transfers induced by crop transpiration and by condensation along the greenhouse walls. The aim was, to validate the CFD model by comparing simulations with experimental results and to analyse in detail the influence of external conditions, heating and glass properties on the greenhouse climate. Five parameters were successively tested: external temperature, wind velocity, sky temperature, emissivity of the glass and ground heat flux. Results revealed the ability of the model to predict both the air and wall temperatures of the greenhouse. The root-mean-square difference between the simulations and measurements was <1 K for all temperatures and <11% for relative humidity. Condensation appears to have a strong impact on the resulting relative air humidity inside the greenhouse. A sensitivity analysis showed that low external or sky temperatures may increase condensation because they lead to a considerable decrease in wall temperature.


      PubDate: 2014-09-25T01:16:39Z
       
  • Finite element method model of the mechanical behaviour of Jatropha curcas
           L. bulk seeds under compression loading: Study and 2D modelling of the
           damage to seeds
    • Abstract: Publication date: November 2014
      Source:Biosystems Engineering, Volume 127
      Author(s): Michal Petrů , Ondřej Novák , David Herák , Ivan Mašín , Petr Lepšík , Petr Hrabě
      This article is focused on comprehensive research of a pressing process of Jatropha curcas L. bulk seeds during linear compression. Compression experiments were performed and the strain and brittle fracturing of the seeds visualised. The mechanical behaviour and stress distribution at the volumetric strain of bulk seeds in pressing cylinders and semi-cylinders with diameters of 60, 80 and 100 mm were described by 2D FEM models. It has been determined that the study of nonlinear visco-elastic and plastic strain seed interactions and the damage and crack growth in such seeds can be significantly improved through computer simulations using an explicit FEM algorithm. In this study, the compressibility of ripe J. curcas L. bulk seeds was analysed and compared depending on the volume strain and energy performance of the linear pressing process. Empirical equations and differential deformation theory describing the seeds interacting beyond the oil point were reported. In addition, the issue of contact theory in numerical modelling of the point contact of interacting seeds was also described. Statistical results showed that the 2D FEM model can be used to study the volumetric strain, stress and damage of J. curcas L. bulk seeds. These studies suggest that FEM models may be considered an important tool to assess the energy performance of the pressing process of J. curcas bulk seeds and can provide valuable information for the design and optimisation of pressing equipment.


      PubDate: 2014-09-18T00:24:06Z
       
  • Soil translocation by narrow openers with various bent leg geometries
    • Abstract: Publication date: November 2014
      Source:Biosystems Engineering, Volume 127
      Author(s): Aliakbar Solhjou , John M. Fielke , Jacky M.A. Desbiolles , Chris Saunders
      No-till farmers in Australia often use narrow point openers to place seed and fertiliser in furrows in conjunction with the spraying of pre-emergence herbicides. These openers can produce excessive soil throw which creates problems such as increasing the depth of soil cover on adjacent furrows, herbicide contamination above seed in adjacent furrows, increased stimulation of weed seed germination and furrow moisture loss. This study evaluated the effect of a range of bent leg narrow opener geometries on soil movement when operating at 120 mm depth and 8.2 kmh−1. Results showed that a bent leg opener geometry combined with a chamfered face could loosen a furrow without throwing soil laterally out of the furrow due to the shank being offset (bent) away from the central upheaval of soil. The bent leg openers were also able to loosen soil with minimal mixing of soil layers. Increasing the shank offset from the furrow centre reduced the surface soil interaction with the vertical shank section operating in the furrow. Decreasing the side bend angle from 65° to 45° reduced surface tracer lateral movement. Adding a leading foot to a bent leg opener reduced the loosened cross sectional area by 13% due to the shallower engagement of the side-leg portion. These findings have implications for optimising no-till seeding practises through better control of soil throw, aiming to: reduce weed seed germination and soil moisture loss, enable narrower row spacing options, the safer use of pre-emergence herbicides incorporated when seeding and higher operating speeds.


      PubDate: 2014-09-18T00:24:06Z
       
  • Estimating aboveground green biomass in desert steppe using band depth
           indices
    • Abstract: Publication date: November 2014
      Source:Biosystems Engineering, Volume 127
      Author(s): Hongrui Ren , Guangsheng Zhou
      Estimation of aboveground green biomass is essential for evaluating grassland productivity and functioning. This study aimed to explore the potential of band depth indices for estimating aboveground green biomass in grassland with low canopy cover. Field spectral and biomass measurements were conducted during 2009 and 2010 growing seasons in desert steppe of Inner Mongolia. Band depth (BD), band depth ratio (BDR), normalised band depth index (NBDI), band depth normalised to area (BNA), maximum band depth (BDmax), and area of absorption region (BDarea) extracted from red absorption region (650–740 nm) were utilised as band depth indices. Results indicated that: (1) BD at individual bands between 655 and 716 nm showed good accuracy for aboveground green biomass estimation; (2) BD at 698 nm yielded the best accuracy (R 2 = 0.7, RMSECV = 29.6 g m−2 for calibration; RMSE = 32.4 g m−2, rRMSE = 26.9% for validation); (3) BDR, NBDI, and BNA at all bands were not reliable estimators of aboveground green biomass (R 2 < 0.3, RMSECV > 45 g m−2 for calibration; RMSE > 46 g m−2, rRMSE > 39% for validation); (4) although the performance of BDmax (R 2 = 0.65, RMSECV = 32.1 g m−2 for calibration; RMSE = 34.5 g m−2, rRMSE = 28.7% for validation) and BDarea (R 2 = 0.69, RMSECV = 30.2 g m−2 for calibration; RMSE = 33.1 g m−2, rRMSE = 27.6% for validation) was slight lower than that of BD698nm, the performance was far better than that of BDR, NBDI, and BNA. Our results suggest that BD698nm has good potential to estimate aboveground green biomass in grassland with low canopy cover. The performance of BD698nm needs to be further tested using space-borne hyperspectral images.


      PubDate: 2014-09-18T00:24:06Z
       
  • Comparison between a rollover tractor dynamic model and actual lateral
           tests
    • Abstract: Publication date: November 2014
      Source:Biosystems Engineering, Volume 127
      Author(s): Bruno Franceschetti , Roland Lenain , Valda Rondelli
      Despite the progress in tractor design with respect to safety, one of the most dangerous situations for the driver under operating conditions on agricultural machines is the lateral rollover. Several accidents involving tractor rollover have indeed been encountered, requiring the design of a robust Roll-Over Protective Structure (ROPS). A mathematical model representing the behaviour during a generic tractor lateral rollover, with the possibility of modifying the geometry, the inertia of the tractor and the environmental boundary conditions is herein proposed. The purpose was to define a method allowing the prediction of the elasto-plastic behaviour of the impacts occurring in the rollover phase. In particular, this paper proposes a tyre impact model capable of analysing the influence of the wheels on the energy to be absorbed by the ROPS. Different tractor design parameters that affect the rollover behaviour, such as mass and dimensions, were considered and their influence on the energy absorbed by the ROPS was determined. The model was designed and calibrated with respect to the results of actual tests carried out on a narrow-track tractor. The results of the model showed a good match with the dynamic behaviour and energy absorbed by the ROPS in experimental lateral rollover tests. This should permit good prediction of the amount of energy to be absorbed in some accident situations, and therefore assist in the design of protective structures.


      PubDate: 2014-09-18T00:24:06Z
       
  • Microwave-assisted treatment for continuous olive paste conditioning:
           Impact on olive oil quality and yield
    • Abstract: Publication date: November 2014
      Source:Biosystems Engineering, Volume 127
      Author(s): Antonia Tamborrino , Roberto Romaniello , Riccardo Zagaria , Alessandro Leone
      Olive paste conditioning using microwave technology was integrated into an olive oil extraction plant using industrial-scale microwave-assisted apparatus. This first effort at integrating microwave technology contributed significantly to the continuous conditioning of the olive paste. The components of the equipment were designed and sized for optimal efficiency in an earlier preliminary study. With the aim of improving the operation of the extraction plants towards providing a continuous management of the process, an investigation of effects of optimal scheduling on olive oil quality was conducted. The objective was to evaluate the impact of the microwave treatment used to condition the olive paste on olive oil quality and yield and comparing it with the conventional industrial malaxation. The short process time of the rapid microwave treatment resulted in a low oxidation of the olive oil and consequently a reduction in the peroxide value compared with the conventional method. Using the microwave treatment, a higher concentration of volatile compounds in the oil was obtained with a lower content of phenolic compounds that are associated with spicy and bitter notes. No significant differences were found with extraction yield. Microwave processing was therefore confirmed as an attractive alternative to the conventional malaxation, with the main advantages being the rapid processing time and the high olive oil quality.


      PubDate: 2014-09-18T00:24:06Z
       
  • Measurements of emission factors from a naturally ventilated commercial
           barn for dairy cows in a cold climate
    • Abstract: Publication date: November 2014
      Source:Biosystems Engineering, Volume 127
      Author(s): Ngwa M. Ngwabie , Andrew Vanderzaag , Susantha Jayasundara , Claudia Wagner-Riddle
      Emission rates of CH4, N2O and NH3 were measured in a commercial free-stall barn that housed 141 lactating dairy cows, and 75 dry cows and replacement heifers. Animal activity, measured using the ALPRO™ dairy herd management system was used together with the CO2 balance method to calculate the ventilation rate. Methane emission was also modelled using the IPCC Tier 2 method. Animal activity variations similar to reported patterns indicated that the activity monitoring system provided high resolution measurements since all cows were considered. Diurnal variations were observed in the emissions with mean values of 12.2–13.9 g CH4 LU−1 h−1, 0.43–0.64 g NH3 LU−1 h−1 and 29.4–41.3 mg N2O LU−1 h−1. Modelled enteric CH4 emission was 312 g CH4 head−1 d−1 (10.58 g CH4 LU−1 h−1). It was estimated that indoor manure emitted 73 g CH4 head−1 d−1 (2.5 g CH4 LU−1 h−1), with enteric fermentation representing 81% of the total barn CH4 emission. Lactating cows emitted about 363 g CH4 head−1 d−1 (11.42 g CH4 LU−1 h−1) while non-lactating cows emitted 241 g CH4 head−1 d−1 (9.67 g CH4 LU−1 h−1).


      PubDate: 2014-09-18T00:24:06Z
       
  • Improved pig slurry mechanical separation using chitosan and biochar
    • Abstract: Publication date: November 2014
      Source:Biosystems Engineering, Volume 127
      Author(s): Popovic Olga , Gioelli Fabrizio , Dinuccio Elio , Balsari Paolo
      The efficient separation of pig slurry into its solid and liquid components is useful on a farm where the removal of excess nutrients is desired. This study investigates the effectiveness of two pre-treatments (chitosan, and biochar) in separating pig slurry using two methods of mechanical separation (screw press SP and centrifugation CENT). Several indicators—high dry matter and phosphorus in solids, and low P, Cu, and Zn content in liquids—informed the evaluation. Overall, results showed that chitosan addition changed the elemental content in both fractions of the SP group, but not in liquid fractions of the CENT group. Chitosan produced loosened flocs sensitive to SP pressure, but more resistant to centrifugation. Added biochar increased mass efficiency by 2–3% in both separation methods, but had little effect on the chemicals tested, except for the elemental content of solids produced in the SP group. The combination of chitosan and biochar performed worse than when treated with chitosan alone. Based on simple and reduced separation indices, no treatments affected the separation efficiency of the mechanical separators. Despite pre-treatment failures, there is some indication that under different experimental conditions, these pre-treatments may be beneficial when separating manure.


      PubDate: 2014-09-18T00:24:06Z
       
  • Multispectral fluorescence imaging for detection of bovine faeces on
           Romaine lettuce and baby spinach leaves
    • Abstract: Publication date: November 2014
      Source:Biosystems Engineering, Volume 127
      Author(s): Hoyoung Lee , Colm D. Everard , Sukwon Kang , Byoung-Kwan Cho , Kuanglin Chao , Diane E. Chan , Moon S. Kim
      Hyperspectral fluorescence imaging with ultraviolet-A excitation was used to evaluate the feasibility of two-waveband fluorescence algorithms for the detection of bovine faecal contaminants on the abaxial and adaxial surfaces of Romaine lettuce and baby spinach leaves. Correlation analysis was used to select the most significant waveband pairs for two-band ratio and difference methods in distinguishing contaminated and uncontaminated leaf areas. For this investigation, two-band ratios using bands at 665.6 nm and 680.0 nm (F665.6/F680.0) for lettuce and at 660.8 nm and 680.0 nm (F660.8/F680.0) for spinach effectively differentiated all contamination spots applied to the lettuce and spinach leaves, respectively. The fluorescence emission peaks for the faecal matter of animals that consume green plant materials and for chlorophyll a occur in close proximity in the red spectral region. Consequently, a high spectral resolution would be required for multispectral imaging with these two-band ratios for online implementation to detect bovine faecal contamination on leafy greens such as Romaine lettuce and baby spinach.


      PubDate: 2014-09-18T00:24:06Z
       
  • Modelling soil erosion risk for pipelines using remote sensed data
    • Abstract: Publication date: November 2014
      Source:Biosystems Engineering, Volume 127
      Author(s): Herbert K. Winning , Mike J. Hann
      This paper presents a method of using GIS and public domain remote sensed data to perform a preliminary soil erosion risk analysis aggregated into 1,000 m sections for onshore pipeline corridors. The results obtained using this method correspond well with the soil erosion risk assessment carried out in the field, with over 69% in agreement and 95% of the results obtained being within ±1 erosion classification identified by the field data. The areas where this method fails to correctly classify the soil erosion risk are identified and are largely confined to major river crossings and areas of seismic activity, which would require field verification irrespective of the results obtained for these sections using this method. The limitations of the proposed method due to the lack of detailed soil data and strategies to mitigate poor soil data are discussed. Using this method it is possible to identify areas along the pipeline corridor where there is potential for soil erosion risk early on in the project design; this enables the route selection process to consider this important environmental aspect, as well as providing a basis for focusing any subsequent field investigation. The proposed method enables the erosion risk to be quickly reassessed to compare different route options or to revise the proposed pipeline route.


      PubDate: 2014-09-18T00:24:06Z
       
  • Detecting crop water status in mature olive groves using vegetation
           spectral measurements
    • Abstract: Publication date: Available online 15 September 2014
      Source:Biosystems Engineering
      Author(s): Giovanni Rallo , Mario Minacapilli , Giuseppe Ciraolo , Giuseppe Provenzano
      Full spectral measurements (350–2500 nm) at tree canopy and leaf levels and the corresponding leaf water potentials (LWP) were acquired in an olive grove of Sicily, at different hours of the day, during summer season 2011. The main objective of the work was to assess, on the basis of the experimental data-set, two different approaches to detect crop water status in terms of LWP. Specifically, using existing families of Vegetation Indices (VIs) and applying Partial Least Squares Regression (PLSR) were optimised and tested. The results indicated that a satisfactory estimation of LWP at tree canopy and leaf levels can be obtained using vegetation indices based on the near infrared–shortwave infrared (NIR–SWIR) domain requiring, however, a specific optimisation of the corresponding “centre-bands”. At tree canopy level, a good prediction of LWP was obtained by using optimised indices working in the visible domain, like the Normalized Difference Greenness Vegetation Index (NDGI, RMSE = 0.37 and R 2 = 0.57), the Green Index (GI, RMSE = 0.53 and R 2 = 0.39) and the Moisture Spectral Index (MSI, RMSE = 0.41 and R 2 = 0.48). On the other hand, a satisfactory estimation of LWP at leaf level was obtained using indices combining SWIR and NIR wavelengths. The best prediction was specifically found by optimising the MSI (RMSE of 0.72 and R 2 = 0.45) and the Normalized Difference Water Index (NDWI, RMSE = 0.75 and R 2 = 0.45). Even using the PLSR technique, a remarkable prediction of LWP at both tree canopy and leaf levels was obtained. However, this technique requires the availability of full spectra with high resolution, which can only be obtained with handheld spectroradiometers or hyper-spectral remote sensors.


      PubDate: 2014-09-18T00:24:06Z
       
  • Bulk properties of densified hop cones related to storage and throughput
           measurements
    • Abstract: Publication date: October 2014
      Source:Biosystems Engineering, Volume 126
      Author(s): František Kumhála , Jiří Blahovec
      Hop is one of the most important materials for beer production. Nevertheless the material density of hop is little known even though this information is needed for the harvesting, processing and storage of the hop cones. To fill this gap in knowledge, densification experiments were carried out during 2013 harvesting season with wet and dry hop cones of different varieties. It was shown that for hop cones of all varieties in dry state that pressure increased with increasing material density. In a wet state, Sladek and Vital varieties showed different behaviour. Higher initial densities meant greater hardness of those two varieties. The densification process caused significant increase in the densification curve slope at the initial and final points. The initial slope was very high for the Sladek and Vital varieties in a wet state. Resulting pressure values were statistically different for most of the tested varieties. The differences in densification parameters were in all cases transferred from the wet to dry states. Differences found between varieties can significantly influence hop material throughput during harvesting as well as the behaviour of hop cones during post-harvest processing and storage.


      PubDate: 2014-09-04T22:47:12Z
       
  • Greenhouse gas emissions during composting of dairy manure: Influence of
           the timing of pile mixing on total emissions
    • Abstract: Publication date: October 2014
      Source:Biosystems Engineering, Volume 126
      Author(s): Walter Mulbry , Heekwon Ahn
      The effect of the timing of pile mixing on greenhouse gas (GHG) emissions during dairy manure composting was determined using large flux chambers designed to completely cover replicate pilot-scale compost piles. Approximately 50–70% of total CO2 and 75–80% of CH4 emissions occurred within the first two weeks of composting. Total GHG emissions from compost piles that were mixed at 2, 3, 4, or 5 weeks after initial construction were not significantly different from the emissions from unmixed (static) piles during a six week trial period. Although delaying initial pile mixing (2, 3, 4, or 5 weeks) generally lead to decreases in CO2 emissions, delaying mixing did not significantly affect CH4 or total GHG emissions. When normalised for degraded volatile solids (VS), CO2, CH4, N2O, and total emissions values ranged from 600--700, 130--150, 50--100, and 800–950 g CO2-eq per kg VS degraded, respectively. Carbon dioxide, methane, and nitrous oxide accounted for 75%, 14–19%, and 6–12%, respectively, of total GHG emissions from static and mixed piles.


      PubDate: 2014-09-04T22:47:12Z
       
  • Non-destructive technology associating PIV and Sunset laser to create wood
           deformation maps and predict failure
    • Abstract: Publication date: October 2014
      Source:Biosystems Engineering, Volume 126
      Author(s): Tomé M. Souza , Ellem W.N.F. Contado , Roberto A. Braga , Henrique C. Barbosa , José T. Lima
      Mechanical tests on wood specimens are usually made using a Universal Testing Machine (UTM) which allows the monitoring both of deformation and the moment of failure. However, besides the destruction of the samples, it is not possible to evaluate through these tests the distribution of deformations and the intensity of the forces involved throughout the sample, particularly in heterogeneous materials such as wood. Among the non-destructive techniques, optical approaches are available associated with image analysis that can overcome the destruction of samples and can even be used when one cannot remove a piece of wood installed in a building structure. This study presents an optical approach using particle image velocimetry (PIV) to create deformation maps of wood specimens under loading, without contact. A laser beam was placed parallel to the wood surface emphasising the irregularities, which are used as particles in the PIV method, and are monitored during the deformation of three different wood species during tests in the UTM. The results showed that the optical approach, using a Sunset laser in conjunction with the PIV method, could monitor the deformation of the samples in a non-destructive way, mainly in the elastic region. It was possible to predict the failure of the specimen earlier than by the UTM. In addition, the method presented a deformation map of the wood specimens allowing additional understanding of the phenomena.
      Graphical abstract image

      PubDate: 2014-09-04T22:47:12Z
       
  • Editorial Board
    • Abstract: Publication date: October 2014
      Source:Biosystems Engineering, Volume 126




      PubDate: 2014-09-04T22:47:12Z
       
  • Comments on “Weed recognition using image blur information” by
           Peng, Z. &amp; Jun, C., Biosystems Engineering 110 (2), p.
           198–205
    • Abstract: Publication date: October 2014
      Source:Biosystems Engineering, Volume 126
      Author(s): Jan Flusser , Tomáš Suk , Barbara Zitová
      This research note is in reaction to a recent paper on weed recognition using image analysis (Peng & Jun, 2011). Here, the correct use of moment invariants in a weed recognition system is presented.


      PubDate: 2014-09-04T22:47:12Z
       
  • System dynamics modelling of an integrated pig production supply chain
    • Abstract: Publication date: November 2014
      Source:Biosystems Engineering, Volume 127
      Author(s): Kullapapruk Piewthongngam , Prasert Vijitnopparat , Supachai Pathumnakul , Sawvapark Chumpatong , Monchai Duangjinda
      The supply chain for pigs is a long chain that is not resilient to environmental changes. The most vulnerable point in the chain occurs at the pig production level, which consists of breeding units, great grandparents, grandparents, parents and fattening units. Similar to other agricultural chains, the pig chain is susceptible to disruptions, such as disease outbreaks. The reaction to any disruptions in supply or demand can take several months or even years. A manager might be unable to anticipate changes in the production units and, thus, be unable to effectively manage the chain. In this study, we develop a system dynamics model as a tool for managers to visualise the movement of the entire production chain. This tool enables the integration of important factors at each breeding level that will affect the number of fattening pigs. Scenarios were applied to explore the mechanism of the model, and case studies were developed to represent an integrated pig company.


      PubDate: 2014-09-04T22:47:12Z
       
  • Fatigue life assessment of a four-rotor swather based on rainflow cycle
           counting
    • Abstract: Publication date: November 2014
      Source:Biosystems Engineering, Volume 127
      Author(s): Dimitris S. Paraforos , Hans W. Griepentrog , Stavros G. Vougioukas , Dietrich Kortenbruck
      Assessing the fatigue life of agricultural machinery is a challenging task, especially when the machine assumes different configurations in various operating modes. In such cases, assessing fatigue life requires the recording of loads at high stress points on the machine chassis during every possible mode of operation. In this paper strain data were recorded at critical, high-stress points of a four-rotor swather, along with acceleration data on the main axle. All data were georeferenced using a global navigation satellite system (GNSS). Measurements were performed while the machine was transported on asphalt and along unmade roads that are typically used by farmers. Additionally, data were acquired during swathing operations in grass fields with different conditions and speeds. For each experiment performed the rainflow cycle counting method was used to extract load cycles from stress data, and the Palmgren-Miner method was used to determine the fatigue damage from each individual cycle, as well as the total accumulated fatigue damage. The results indicated the ability of the system to identify and quantify the damage that was accumulated in every operation mode of the swather. The transition between these operating modes, e.g. lifting the rotors for headland turning, proved to have a high impact on machine fatigue life. Fatigue damage under working conditions in grass fields was also increased by surface irregularities.


      PubDate: 2014-09-04T22:47:12Z
       
  • Environmental analysis of geothermal heat pump and LPG greenhouse heating
           systems
    • Abstract: Publication date: November 2014
      Source:Biosystems Engineering, Volume 127
      Author(s): Giovanni Russo , Alexandros S. Anifantis , Giuseppe Verdiani , Giacomo Scarascia Mugnozza
      The use of low-impact energy sources for greenhouse cultivations is growing quickly due to environmental demands, constrained by the increased price of fossil energy sources, market demand for low cost greenhouse production, and need for air pollution reduction. This paper demonstrates via environmental analysis the efficiency of a Photovoltaic-Geothermal Heat Pump integrated system (PV-GHP) as a greenhouse heating system, compared to a conventional hot air generator using liquefied petroleum gas (LPG-HG). The tests were carried out in twin experimental greenhouses in the Mediterranean area (Valenzano-Italy). In order to evaluate the environmental performance of a heat pump system with electricity supplied from the national grid, a scenario (GHP Geothermal Heat Pump) was realised. The microclimatic conditions in the two greenhouses, the thermal energy produced, and the electricity consumption were analysed. Furthermore, in order to evaluate the long-term environmental impact, an environmental analysis was conducted using life cycle assessment (LCA) methodology, carried out according to standard UNI EN ISO 14040. The interpretation of the results using method CML2001 (Centre of Environmental Science, Leiden, Netherlands) showed that neither system is more advantageous from an environmental point of view and that the GHP scenario has the higher environmental burdens. Limiting the analysis to the emissions responsible for the greenhouse effect, the plant with the geothermal heat pump and photovoltaic panels reduces carbon emissions by 50%. In order to assess the sustainability of the geothermal heat pump plant, the estimated payback-time for energy and for carbon emissions were 1 year and 2.25 years, respectively.


      PubDate: 2014-09-04T22:47:12Z
       
  • Design criteria for structural design of silage silo walls
    • Abstract: Publication date: October 2014
      Source:Biosystems Engineering, Volume 126
      Author(s): Hans E. von Wachenfelt , N. Christer Nilsson , Göran I. Östergard , N. Anders Olofsson , J. Marie Karlsson
      Existing Swedish design guidelines (JBR) cover silo wall heights up to about 3 m. These guidelines presumably overestimate the forces and pressures exerted by silage juice when silo walls are more than 3 m high, which could result in over-sizing, material waste and increased capital costs. This study determined silage physical properties in terms of horizontal wall pressure and evaluated silage juice levels in silos with a wall height of 3 m or more. Wall pressure was measured by transducers mounted on a steel ladder rack placed vertically along the internal silo wall. The ladder rack also permitted measurement of silage juice levels in slotted steel pipes. The pressure on the transducers was recorded by a data acquisition system displaying static and total loads (pressures imposed by silage material without and with the compaction machine, respectively). The static pressure at the bottom of the silo wall (4 m) was 16 kPa during filling and compaction, and 22 kPa 1–4 months after filling. The silage juice did not interact with compaction. The wall pressure increased by 30% after filling, but the increase was only significant at 1 m from the silo bottom. The dynamic load was 17 kPa when the compaction machine passed 0.1 m from the silo wall. New guidelines are proposed based on the results and on the Eurocode for ultimate limit states (ULS) for two stages; filling and the utility period. The design bending moment for ULS was 21% lower than specified in JBR.


      PubDate: 2014-08-18T21:03:41Z
       
  • Advances in agricultural machinery management: A review
    • Abstract: Publication date: October 2014
      Source:Biosystems Engineering, Volume 126
      Author(s): Dionysis D. Bochtis , Claus G.C. Sørensen , Patrizia Busato
      The introduction of intelligent machines and autonomous vehicles to agricultural operations will allow for increased efficiency as well as for reduced environmental impact. Currently, innovative sensing and actuating technologies together with improved information and communication technologies provide the potential for such advancements. However, the full exploitation of these engineering advances requires the traditional agricultural machinery management process to be revisited. As a result, traditional agricultural operations planning methods, especially the job-shop planning methodology, must be supplemented with new planning features, such as route planning and sequential task scheduling. The objectives of this review are to outline current and required advances in agricultural machinery management to prepare for future intelligent manned and/or autonomous sustainable operations in agriculture. In the following sections, five key management tasks for agricultural machinery management are selected that span the various management phases and levels. These tasks are i) capacity planning (strategic level), task times planning (tactical level), scheduling (operational), route planning (operational level), and performance evaluation (evaluation level). For each of the management tasks, a definition is provided, and the most recent related literature is presented. Finally, the future requirements which will facilitate and set the framework for the development efforts necessary for fully implementing future agricultural management models and tools are discussed.


      PubDate: 2014-08-14T20:47:20Z
       
  • The impact and retention of spray droplets on a horizontal hydrophobic
           surface
    • Abstract: Publication date: October 2014
      Source:Biosystems Engineering, Volume 126
      Author(s): Ingrid K. Zwertvaegher , Micheline Verhaeghe , Eva Brusselman , Pieter Verboven , Frederic Lebeau , Mathieu Massinon , Bart M. Nicolaï , David Nuyttens
      Spray retention, i.e. the overall capture of spray droplets by plants on initial or subsequent impact, and after loss due to run-off, is an important stage in the spray application process as droplet losses may result in reduced efficacy, economic loss, and environmental contamination. The aim of this exploratory study is to determine whether a new method based on calculating the volumetric proportions per impact type, i.e. adhesion, rebound and shatter, can be used to predict spray retention. These volumetric proportions are calculated based on logistic regression models, derived from vision-based droplet characteristics and impact assessments, and laser-based spray characteristics. The advantages and limitations of such a method are explored. The volumetric proportions per impact type on a horizontal, synthetic hydrophobic surface were determined for four different nozzles (XR 110 01 VS flat-fan nozzle, XR 110 04 VS flat-fan nozzle, XR 110 08 VS flat-fan nozzle and AI 110 08 VS air-induction nozzle) under controlled realistic conditions, and compared to the results of a retention test. The volumetric proportions of adhesion were much lower than the relative retentions, indicating that a considerable amount of rebound and shatter also contributed to final retention. The method should thus be improved by including the droplets retained after first impact and the retained proportions of partial droplet fragmentation but it is nevertheless considered a promising technique.


      PubDate: 2014-08-14T20:47:20Z
       
  • Carbon dioxide production from a fattening pig building with partial pit
           ventilation system
    • Abstract: Publication date: October 2014
      Source:Biosystems Engineering, Volume 126
      Author(s): Chao Zong , Guoqiang Zhang , Ying Feng , Ji-Qin Ni
      Carbon dioxide (CO2) is useful for determining ventilation rates in livestock buildings and its release from manure plays an important role in ammonia emission. CO2 production in a fattening pig house with a partial pit ventilation system was investigated under working conditions. The influences of animal mass, animal activity, and ventilation rate on CO2 concentrations and emissions were assessed. Results showed that the CO2 production rate increased with growing pig body mass. A mathematical model of CO2 production was developed based on the measured data. The measured CO2 productions ranged from 30.3 to 99.0 g h−1 pig−1 for pigs from 30.1 to 111.5 kg. Comparing the last days of the fattening period with and without pigs, it was found that 2.3–3.4% of the total CO2 production was released from manure. Higher pit ventilation rates resulted in higher CO2 concentration in pit air and higher emission rates via pit exhaust, but had limited influence on the total emission rate (via room + pit exhaust). However, higher room ventilation rates resulted in lower CO2 concentrations in room air but higher room and total emission rates. Diurnal variations in CO2 productions were mainly influenced by animal activities. Four models of CO2 production in literature were reviewed and compared with the model developed in this study. The CO2 production model developed in this study had similar values with the CIGR model for a pig under 80 kg and the TCER model for a pig above 60 kg.


      PubDate: 2014-08-14T20:47:20Z
       
  • Co-robotic intra-row weed control system
    • Abstract: Publication date: October 2014
      Source:Biosystems Engineering, Volume 126
      Author(s): Manuel Pérez-Ruíz , David C. Slaughter , Fadi A. Fathallah , Chris J. Gliever , Brandon J. Miller
      The automation of intra-row weed control in row crop production systems is very challenging. This work describes the development and in-field assessment of an automatic intra-row, hoe-based weeding co-robot system with real-time pneumatic hoe actuation based on an accurate odometry sensing technique. The US National Science Foundation has identified a need for robots (called co-robots) that serve as co-workers and work beside, or cooperatively with, people. These co-robots have a symbiotic relationship with a human partner, where, as a team, they combine their relative strengths to jointly perform a task. Such co-robots should be relatively inexpensive and easy to use. In this work, mechanical weed control was achieved by a co-robot actuator that automatically positioned a pair of miniature hoes into the intra-row zone between crop plants. The design was tested in a precision transplanted row crop and may also be suitable for direct seeded row crops. Co-robot cost was minimised by limiting the system to a single, simple odometry sensor. Co-robot hoe actuation was controlled using pre-programmed knowledge of the crop planting pattern and real-time odometry data as the control input for hoe positioning. Low-frequency drift in the odometry control points relative to the actual plant locations was corrected occasionally as needed in real-time by a human partner monitoring system performance. The co-robot was evaluated in an experimental trial conducted on the UC Davis campus farm. Assessment was based upon the follow-up hand hoeing required after automated intra-row weeding in comparison to the labour required to manually hoe a control plot. The mean person hours required for hand hoeing weeds in the control were 0.241 h for the 100 m2 plot, while only 0.102 h 100 m−2 were required in follow-up labour to complete the weed removal in the plots weeded by the co-robot. This represents a 57.5% reduction in hand labour requirements for intra-row weed control and indicates that the co-robot could help reduce traditional hand hoeing labour requirements with mechanised weed control in intra-row areas between the crop plants.


      PubDate: 2014-08-14T20:47:20Z
       
  • Randomised kinodynamic motion planning for an autonomous vehicle in
           semi-structured agricultural areas
    • Abstract: Publication date: October 2014
      Source:Biosystems Engineering, Volume 126
      Author(s): Mohamed Elbanhawi , Milan Simic
      A randomised motion planner is presented that operates within a suitable timeframe for constrained mobile robots in agricultural environment. The core of this approach relies on splitting planning into two efficient phases to reduce its computational time. The effectiveness of sampling based planners is combined with the robustness of parametric vector-valued splines. The first phase involves relaxed two-dimensional path planning using rapidly-exploring random trees (RRT). Recent advances in sampling based planning are leveraged to improve the performance of the planner. Detailed implementation of the RRT approach and parameter selection are highlighted using comprehensive analysis and simulations. Feasible continuous paths with bounded curvature for nonholonomic robots are generated using B-spline curves. Curve segment parameters are formulated with respect to vehicle specifications. Manoeuvres satisfying maximum curvature constraints and path continuity are designed based on the segment parameters. Numerical experiments are used to validate the practicality of the proposed two-phase planner in solving kinodynamic motion queries, in real-time and replanning under limited sensing conditions.


      PubDate: 2014-08-14T20:47:20Z
       
  • Determination of the elastic constants of Scots pine (Pinus sylvestris L.)
           wood by means of compression tests
    • Abstract: Publication date: October 2014
      Source:Biosystems Engineering, Volume 126
      Author(s): José R. Aira , Francisco Arriaga , Guillermo Íñiguez-González
      This presents an exploratory analysis of a method for the determination of elastic constants using strain gauges in compression tests. The elastic constants of Scots pine (Pinus sylvestris L.) wood from the “Valsaín” sawmill (Segovia, Spain) were obtained. Compression tests were performed on small clear specimens, varying grain direction with respect to the direction of the load applied. Deformations were measured by strain gauges bonded on specimen surfaces. The modulus of elasticity parallel to the grain was obtained for prismatic specimens measuring 20 × 20 × 60 mm. The modulus of elasticity perpendicular to the grain in both radial and tangential directions was obtained for 16 × 16 × 48 mm prismatic specimens and for 48 × 48 × 48 mm cubic specimens. The shear modulus in the LR, LT and TR (longitudinal (L), radial (R) and tangential (T)) planes was obtained for 16 × 16 × 48 mm prismatic specimens with the grain at 45°. Larger stiffness values than typical average values for softwood were obtained. It can be concluded that this method is suitable for determining the modulus of elasticity (longitudinal and transversal), and that the values obtained are greater than the average values for softwoods. On the other hand, the Poisson ratios obtained parallel to the grain were similar to values in the literature, though values for ν RT and ν TR were greater.


      PubDate: 2014-08-05T20:00:15Z
       
  • Source of airborne sunflower dust generated during combine harvester
           operation
    • Abstract: Publication date: October 2014
      Source:Biosystems Engineering, Volume 126
      Author(s): Joseph P. Polin , Zhengrong Gu , Daniel S. Humburg , Kevin J. Dalsted
      The sunflower harvest season presents challenges for many farmers when an abundance of airborne dust is carried by surrounding winds and allowed to relocate on equipment surfaces. Combine fires are a serious problem resulting from the ignition of biomass dust that settle and accumulate on the combine harvester. Farmers' anecdotal evidence indicates that harvesting sunflowers can produce more airborne dust than other commodity crops. The source of this airborne sunflower dust was investigated using various methods to analyse different parts of the sunflower: whole heads, outer stalk, and inner stalk pith. These samples were compared to a collected amount of bulk sunflower dust field sample taken directly from a horizontal surface on a combine harvester during the 2011 harvest season. All testing methods; proximate and ultimate analyses, biomass dust particle density analysis, Fourier transform infrared spectroscopy, and scanning electron microscopy; suggest the sunflower bulk field sample is comprised of mostly inner stalk pith rather than dust particles from the outer stalk and whole sunflower heads. By confirming the source of the airborne sunflower dust field sample, the arrangement of combine harvester equipment could be modified to reduce the amount of sunflower dust generated during operation.


      PubDate: 2014-08-05T20:00:15Z
       
  • Editorial Board
    • Abstract: Publication date: September 2014
      Source:Biosystems Engineering, Volume 125




      PubDate: 2014-08-01T19:26:23Z
       
  • Feasibility study on the potential of electrical conductivity sensor
           Veris® 3100 for field mapping of topsoil strength
    • Abstract: Publication date: October 2014
      Source:Biosystems Engineering, Volume 126
      Author(s): Mojtaba Naderi-Boldaji , Ahmad Sharifi , Abbas Hemmat , Reza Alimardani , Thomas Keller
      With advances in technology for precision agriculture, numerous attempts have been made towards development of on-the-go sensors for measuring soil compaction. Most of the on-the-go sensors developed so far have been mechanical sensors providing a soil strength parameter that can be related to degree of soil compactness. In this study, a commercial electrical conductivity sensor (Veris® 3100) in combination with a previously developed combined horizontal penetrometer (equipped with a dielectric sensor for water content) were tested in a field in order to examine whether the apparent electrical conductivity (ECa) within the 0–0.3 m depth (ECa-shallow) could be helpful in detecting the topsoil strength (here the horizontal penetrometer resistance). Interpolated field maps of horizontal penetrometer resistance (PR), volumetric water content (θ v) and ECa showed comparable patterns within some areas (but not over the field). No significant correlation (but a negative trend) was found between ECa and dry bulk density. A significant correlation between ECa and PR/θ v (a previously proposed water content-independent PR) was found (R 2 = 0.37, P < 0.0001). However, ECa was strongly affected by soil water content and texture. It was concluded that PR may be indirectly related to ECa through θ v, which greatly affects both ECa and PR. The results suggested that the EC sensor could potentially be helpful for detecting zones of high soil strength (i.e. high PR/θ v). Further studies are suggested to address whether ECa is better related to the state of soil compaction at dry state of soil due to more significant effect of soil–soil electrical conductivity.


      PubDate: 2014-08-01T19:26:23Z
       
  • Active air flushing in a sensor-controlled fresh produce container system
           to maintain the desired modified atmosphere
    • Abstract: Publication date: September 2014
      Source:Biosystems Engineering, Volume 125
      Author(s): Yun Hee Jo , Duck Soon An , Dong Sun Lee
      Modified atmosphere (MA) containers equipped with an on/off-controlled perforation that can respond to real-time gas concentrations can contribute to maintaining the quality of fresh produce. In this study, an active flushing system was devised to flush the air promptly responding to the real-time O2 concentration, and its capability to maintain the target O2 level was compared to that of an O2 switched passive diffusion tube system. A model container with dimensions of 32 × 23 × 18 cm was filled with 350 g spinach and submitted to storage testing under different control regimes and temperatures. The gas concentration in the spinach container was programmed to stay either exactly at 11% or in the range of 11–13%. While the O2 switched passive diffusion tube system could properly control the O2 concentration in the container at the desired level or range when the container was at the low temperature of 10 °C, it could not do so at 20 °C, resulting in O2 concentrations that were too low and CO2 concentrations that were too high. The active flushing system was effective and satisfactorily controlled the gas concentration in the container at the desired level or range at both 10 and 20 °C. Compared to the O2 switched passive diffusion tube system, the active flushing system was more prompt in its response to deviating atmospheric conditions, which was more pronounced in the range control mode. The container with the controlled MA was better at preserving the quality of the produce compared to a perforated control package.


      PubDate: 2014-07-27T19:03:35Z
       
  • Structural design of corrugated boxes for horticultural produce: A review
    • Abstract: Publication date: September 2014
      Source:Biosystems Engineering, Volume 125
      Author(s): Pankaj B. Pathare , Umezuruike Linus Opara
      Corrugated boxes are used extensively for transporting and storing fresh produce in the horticultural industry. These boxes protect their contents from mechanical damage due to drops, impacts, vibration and compression loads. The analysis and prediction of the stacking compression load capacity of corrugated boxes is important to study the response of existing packaging to mechanical stress or to design new boxes to meet postharvest handling conditions. Good design of vented packaging is important in optimising the cooling and ventilation uniformity, minimising quality deterioration of packed produce and maintaining the mechanical integrity of the box. Various experimental and modelling tools are used to investigate the design and mechanical performance of packaging. Experimental studies on mechanical performance of packaging include compression, impact and vibration analysis. Finite element analysis and simulation is useful for study and structural design of ventilated corrugated packaging, considering the shape, location and size of the vent. Advances in information and communication technologies offer new prospects for development of user-friendly software toward integrated design and performance analysis of fresh produce packaging.


      PubDate: 2014-07-27T19:03:35Z
       
  • Characterisation of the dielectric properties of rubber latex from 0.5 to
           33 GHz
    • Abstract: Publication date: September 2014
      Source:Biosystems Engineering, Volume 125
      Author(s): Sakol Julrat , Mitchai Chongcheawchamnan , Ian D. Robertson
      This paper presents a detailed characterisation of the dielectric properties of rubber latex over the entire microwave frequency range (0.5–33 GHz), for samples with a range of dry rubber contents and over the temperature range 10–40 °C. The relaxation processes observed are analysed and compared to pure water, as modelled with the Debye equation. It is shown that two relaxation processes exist in rubber latex, with one of these attributed to the presence of bound water molecules. The extended Debye equation is then applied to model the dielectric permittivity. Each relaxation time extracted from the modelling exposes a different physical mechanism in rubber latex. It is believed that this is the most extensive study of the microwave properties of rubber latex yet reported, and that the results are an important step in the development of microwave sensors for determining the quality of rubber latex for agriculture and industrial application.


      PubDate: 2014-07-27T19:03:35Z
       
 
 
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