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  Subjects -> AGRICULTURE (Total: 662 journals)
    - AGRICULTURAL ECONOMICS (72 journals)
    - AGRICULTURE (444 journals)
    - CROP PRODUCTION AND SOIL (84 journals)
    - DAIRYING AND DAIRY PRODUCTS (25 journals)
    - POULTRY AND LIVESTOCK (37 journals)

AGRICULTURE (444 journals)                  1 2 3 4 5 | Last

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: 1)
Advances in Agriculture & Botanics     Open Access   (Followers: 10)
Advances in Agriculture, Sciences and Engineering Research     Open Access   (Followers: 10)
Advances in Agronomy     Full-text available via subscription   (Followers: 11)
Advances in Life Science and Technology     Open Access   (Followers: 5)
AFBM Journal     Open Access  
Africa Development     Open Access   (Followers: 6)
Africa Research Bulletin: Political, Social and Cultural Series     Hybrid Journal   (Followers: 6)
African Journal of Agricultural Research     Open Access   (Followers: 1)
African Journal of Food Science     Open Access   (Followers: 1)
African Journal of Food, Agriculture, Nutrition and Development     Open Access   (Followers: 2)
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: 3)
Agribusiness : an International Journal     Hybrid Journal   (Followers: 5)
Agricultura Tecnica     Open Access   (Followers: 5)
Agricultura Tropica et Subtropica     Open Access   (Followers: 1)
Agricultural Advances     Open Access   (Followers: 3)
Agricultural and Food Science     Open Access   (Followers: 14)
Agricultural Economics     Hybrid Journal   (Followers: 44)
Agricultural History     Full-text available via subscription   (Followers: 154)
Agricultural Research     Hybrid Journal   (Followers: 2)
Agricultural Science     Full-text available via subscription   (Followers: 5)
Agricultural Sciences     Open Access   (Followers: 7)
Agricultural Sciences in China     Full-text available via subscription   (Followers: 3)
Agricultural Systems     Hybrid Journal   (Followers: 19)
Agricultural Water Management     Hybrid Journal   (Followers: 13)
Agriculture     Open Access   (Followers: 4)
Agriculture & Food Security     Open Access   (Followers: 9)
Agriculture (Poľnohospodárstvo)     Open Access   (Followers: 1)
Agriculture and Agricultural Science Procedia     Full-text available via subscription  
Agriculture and Human Values     Hybrid Journal   (Followers: 10)
Agriculture, Ecosystems & Environment     Hybrid Journal   (Followers: 29)
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: 13)
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: 18)
Applied Financial Economics Letters     Hybrid Journal   (Followers: 5)
Arboricultural Journal : The International Journal of Urban Forestry     Hybrid Journal   (Followers: 6)
Archivos de Zootecnia     Open Access   (Followers: 1)
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: 3)
Asian Journal of Plant Sciences     Open Access   (Followers: 1)
Australian Cottongrower, The     Full-text available via subscription   (Followers: 1)
Australian Economic Papers     Hybrid Journal   (Followers: 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: 1)
Bangladesh Journal of Scientific Research     Open Access  
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: 18)
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: 6)
California Agriculture     Open Access   (Followers: 1)

        1 2 3 4 5 | Last

Journal Cover Biosystems Engineering
   [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  [2563 journals]   [SJR: 0.757]   [H-I: 58]
  • Rainwater harvesting options for rice–maize cropping system in
           rainfed uplands through root-zone water balance simulation
    • Abstract: Publication date: August 2014
      Source:Biosystems Engineering, Volume 124
      Author(s): Bharat C. Sahoo , Sudhindra N. Panda
      A root-zone water balance model was used to simulate the soil moisture storage of maize (Zea mays L.) and rice (Oryza sativa L.) fields in rainfed uplands of eastern India. The simulation study revealed that short duration (95 days) rice fields in uplands remained under ponding condition for a period of 32 days during the entire growing season. Based on the ponding depth requirement in rice fields (50 mm), excess ponding was found for seven days only out of the 32 days of ponding. In contrast, the maize field under similar length of growing season (95 days) and topographic condition could produce harvestable runoff for 23 days. Furthermore, the rice crop was to remain under moisture stress for eight days during its mid-season stage, whereas the maize was found to be without stress during entire growing season. Before sowing of winter crops, the soil moisture in the seeding zone was determined to be depleted below germination soil moisture for 18 and 19 years out of 30 years of simulation in rice and maize fields, respectively. This implies that a second crop, following withdrawal of monsoon, is not possible without pre-sowing irrigation in three out of five years in rainfed uplands. Thus, complete substitution of rice by maize in uplands would create a better scope for rainwater harvesting. Alternatively, partial replacement of rice could be a viable option for meeting both rice demand of the people and harvesting of adequate rainwater for supplemental irrigation to crops in rainy and winter seasons.


      PubDate: 2014-07-27T19:03:35Z
       
  • Deciduous tree reconstruction algorithm based on cylinder fitting from
           mobile terrestrial laser scanned point clouds
    • Abstract: Publication date: August 2014
      Source:Biosystems Engineering, Volume 124
      Author(s): Valeriano Méndez , Joan Ramon Rosell-Polo , Ricardo Sanz , Alexandre Escolà , Heliodoro Catalán
      Vector reconstruction of objects from an unstructured point cloud obtained with a LiDAR-based system (light detection and ranging) is one of the most promising methods to build three dimensional models of orchards. The cylinder fitting method for woody structure reconstruction of leafless trees from point clouds obtained with a mobile terrestrial laser scanner (MTLS) has been analysed. The advantage of this method is that it performs reconstruction in a single step. The most time consuming part of the algorithm is generation of the cylinder direction, which must be recalculated at the inclusion of each point in the cylinder. The tree skeleton is obtained at the same time as the cluster of cylinders is formed. The method does not guarantee a unique convergence and the reconstruction parameter values must be carefully chosen. A balanced processing of clusters has also been defined which has proven to be very efficient in terms of processing time by following the hierarchy of branches, predecessors and successors. The algorithm was applied to simulated MTLS of virtual orchard models and to MTLS data of real orchards. The constraints applied in the method have been reviewed to ensure better convergence and simpler use of parameters. The results obtained show a correct reconstruction of the woody structure of the trees and the algorithm runs in linear logarithmic time.


      PubDate: 2014-07-27T19:03:35Z
       
  • Composting of solids separated from anaerobically digested animal manure:
           Effect of different bulking agents and mixing ratios on emissions of
           greenhouse gases and ammonia
    • Abstract: Publication date: August 2014
      Source:Biosystems Engineering, Volume 124
      Author(s): Md Albarune Chowdhury , Andreas de Neergaard , Lars Stoumann Jensen
      We investigated the effects of bulking agents (BA) and mixing ratios on greenhouse gas (GHG) and NH3 emissions from composting digested solids (DS), separated from anaerobically digested manure and other bio-wastes, in small-scale laboratory composters. BA evaluated were plastic tube pieces (PT), woodchips (WC), bio-char (BC), barley straw (BS) and lupin residues (LR) and were included at a DS:BA of 3:1 or 6:1, resulting in nine treatments: CTDS (control, DS only), PT3:1, PT6:1, WC3:1, WC6:1, BC3:1, BC6:1, BS3:1 and LR3:1. Depending on treatment, C losses via CO2 and CH4 emissions accounted for 41.2–65.3 g C kg−1 initial total solids (TS) and 4.4–191.7 mg C kg−1 TS (8.4–16.1% and 0.001–0.05% of initial total-carbon), respectively, while N losses as N2O and NH3 emissions comprised 2.1–13.6 mg N kg−1 TS and 2.7–4.8 g N kg−1 TS (0.01–0.04% and 9.1–13.0% of initial total-nitrogen), respectively. Most of the CH4 emissions occurred during the thermophilic temperature phase, which had little or no effect on N2O emissions. BS addition to DS resulted in the lowest cumulative NH3-N and N2O-N losses. BC was as effective as BS in reducing cumulative NH3-N losses, but had non-significant effect on CH4-C emissions. Decreasing the mixing ratio from 6:1 to 3:1 reduced losses of CH4-C and N2O-N (except for BC) without any increase in NH3-N losses. BC and BS proved most effective in reducing emissions of total GHG (as CO2-equivalents). Composting of DS with C-rich BA can thus be an effective means of conserving N in DS, while also reducing GHG emissions.


      PubDate: 2014-07-27T19:03:35Z
       
  • An application of the vehicle routing problem to biomass transportation
    • Abstract: Publication date: August 2014
      Source:Biosystems Engineering, Volume 124
      Author(s): Carlos Gracia , Borja Velázquez-Martí , Javier Estornell
      Pruning is a cultural operation linked to Mediterranean agricultural management and it offers through its wastes the chance to procure biofuels. Currently, these residues are disposed of by burning or shredding, not being exploited because of several technical difficulties in extraction, handling and transport as well as because of the lack of accurate data on the quantity and suitability of these residues. However, recent work has reported methods of supplying new biomass detection models and concentration locations. These make it possible to tackle reliable collection plans as a part of the decision support system in a biomass supply management information system. This paper addresses the biomass collection problem, as an application of the classical vehicle routing problem, where minimum cost routes have to be calculated for a fleet of several agricultural vehicles (chippers, trucks, tipper trailers and tractors). A hybrid approach based on genetic algorithms and local search methods is presented to solve a real case study. Results show a significant improvement in the operational efficiency obtained by applying such methods that come from the industrial engineering domain.


      PubDate: 2014-07-27T19:03:35Z
       
  • Characterisation of ventilation rate in naturally-ventilated buildings
           using heat dissipation from a line source
    • Abstract: Publication date: August 2014
      Source:Biosystems Engineering, Volume 124
      Author(s): Ivan Lule , Sezin Eren Özcan , Daniel Berckmans
      To determine air exchange in naturally-ventilated buildings, Eren Özcan, Vranken, and Berckmans (2009) used heat dissipation from a heat source close to an inlet to measure ventilation rate through the opening. Because their method used a bulky heat source, which caused an obstruction to airflow, they were unable to cover the whole of the inlet opening, and therefore, an improved technique was required. This study extended the earlier method to investigate heat dissipation by using a line heat source that covered the whole vertical extent of the inlet. Steady state experiments were performed with a constant heat source, and dynamic experiments, where the heat source was turned off during the ventilation process. A two-dimensional temperature distribution around the ventilation opening was obtained by infrared thermal imaging. Using data-based mechanistic approach, well-mixed temperature zones were used to predict the volumetric concentration of fresh air supply, and to investigate the effect of buoyancy on the heat plume. Results obtained revealed that ventilation rate can be predicted using data-based mechanistic approach with an error of 8%.


      PubDate: 2014-07-27T19:03:35Z
       
  • Advanced exergoeconomic evaluation of a heat pump food dryer
    • Abstract: Publication date: August 2014
      Source:Biosystems Engineering, Volume 124
      Author(s): Zafer Erbay , Arif Hepbasli
      In this study, the results of conventional and advanced exergoeconomic analyses of the performance of a pilot scale air-source heat pump food dryer were compared for the first time. The contributions of the components of the drying system to the exergetic cost effectiveness of the dryer were evaluated, and the effects of changing the inlet drying temperature were determined. The most important system component was determined to be the heat recovery unit, followed by the condenser with respect to the reducing potentials for the total costs of the overall system. Decreasing temperature caused an increase in the cost performance of drying. The modification of the system components for improving the efficiency of the system can be effectively determined through advanced exergoeconomic approach by stating the realistic potential improvements and the priorities in the system.


      PubDate: 2014-07-27T19:03:35Z
       
  • Ultrasound-assisted enzymatic hydrolysis of sugarcane bagasse for the
           production of fermentable sugars
    • Abstract: Publication date: August 2014
      Source:Biosystems Engineering, Volume 124
      Author(s): Felipe C. Lunelli , Pâmela Sfalcin , Matheus Souza , Eduardo Zimmermann , Valéria Dal Prá , Edson L. Foletto , Sérgio L. Jahn , Raquel C. Kuhn , Marcio A. Mazutti
      The effects of ultrasound irradiation on enzymatic hydrolysis of sugarcane bagasse were evaluated to obtain fermentable sugars. The influences of temperature, enzyme concentration and moisture content were evaluated with and without ultrasound irradiation. The hydrolysis yield achieved using ultrasound irradiation was significantly higher than that without. The highest amount of fermentable sugars obtained in the presence of ultrasound was 0.26 g [sugar] g−1 [dry sugarcane bagasse], which was around twice the value obtained without, at the temperature of 50 °C, 10% mass of enzyme and a moisture content of 75% (dry basis), after 240 min of reaction. The ultrasound irradiation appears to be a promising technology to be used in enzymatic reactions due to its positive effects on the reaction yield.


      PubDate: 2014-07-27T19:03:35Z
       
  • Automation and the situation awareness of drivers in agricultural
           semi-autonomous vehicles
    • Abstract: Publication date: August 2014
      Source:Biosystems Engineering, Volume 124
      Author(s): Behzad Bashiri , Danny D. Mann
      The effects of in-vehicle automation and driving assistant systems on the situation awareness of drivers have been the subject of much research with the implications of automation in such man-machine systems being identified. With the introduction of advanced automated systems in agricultural machinery, farmers are now working with semi-autonomous vehicles. A human factors perspective is needed to ensure the safe and efficient operation of such systems. This simulator study investigated the effects of automating vehicle steering and implement control and monitoring task automation on the situation awareness of drivers. Experiments were conducted using a tractor driving simulator located in the Agricultural Ergonomics Laboratory at the University of Manitoba. Thirty young, experienced tractor drivers participated in this study. It was found that implement control and monitoring task automation significantly affected the situation awareness of operators. Situation awareness increased as the level of automation support increased although the highest level of automation, where the participants were removed from the task loop, resulted in low situation awareness at a level similar to the condition with no automation support. The highest level of situation awareness was observed when the simulator suggested the required action to be taken by the operator. Vehicle steering task automation reduced the attentional demand of the task.


      PubDate: 2014-07-27T19:03:35Z
       
  • Modelling of transpiration rate of grape tomatoes. Semi-empirical and
           analytical approach
    • Abstract: Publication date: August 2014
      Source:Biosystems Engineering, Volume 124
      Author(s): Georgios T. Xanthopoulos , Athanasios A. Athanasiou , Diamanto I. Lentzou , Andreas G. Boudouvis , Grigorios P. Lambrinos
      Transpiration is a well known physiological process of water loss from fresh products, associated with visual and texture degradation and loss of market value. A loss of 3–5% of the initial mass may cause in fresh products loss of freshness and visual attractiveness. Grape tomato has been increasingly accepted by consumers as “snacking tomato” and as an ingredient in mixed salads of fresh-cut vegetables. An experimental procedure was developed to record the associated with transpiration, water loss in grape tomatoes (Solanum lycopersicum, Lobello F1), at temperatures 10, 15 and 20 °C and relative humidity 70, 80 and 92%. Water activity was calculated and correlated with the respective mass loss; its average value was found 0.988 ± 0.01. The mean transpiration rates ranged between 0.012 and 0.058 mg cm−2 h−1 for water vapour pressure deficit range of 0.061–0.662 kPa. A semi-empirical and an analytical model were developed to correlate the mass loss of grape tomatoes with the storage conditions (temperature and relative humidity) and storage time. Both provided satisfactory fit to the experimental data. Finally, the air-film mass transfer coefficient (ka) and skin mass transfer coefficient (ks) were calculated and the ks coefficient correlated efficiently with an exponential equation with the respective water vapour pressure deficit.


      PubDate: 2014-07-27T19:03:35Z
       
  • Editorial Board
    • Abstract: Publication date: August 2014
      Source:Biosystems Engineering, Volume 124




      PubDate: 2014-07-27T19:03:35Z
       
  • 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
       
  • Foreground detection of group-housed pigs based on the combination of
           Mixture of Gaussians using prediction mechanism and threshold segmentation
           
    • Abstract: Publication date: September 2014
      Source:Biosystems Engineering, Volume 125
      Author(s): Yizheng Guo , Weixing Zhu , Pengpeng Jiao , Jiali Chen
      In this paper, a foreground detection method to obtain the foreground objects of pigs in overhead views of group-housed environments is proposed. The method is based on the combination of Mixture of Gaussians (MoG) using prediction mechanism (PM) and threshold segmentation algorithm. First, the “valid region” is manually set according to a priori knowledge. Second, the foreground objects of pigs are detected using the PM-MoG algorithm. The algorithm uses the detected binary image of the previous frame to predict the current frame in the valid region for pixels that fulfil background updating conditions. Different update strategies are used to update the background for different circumstances. Third, the maximum entropy threshold segmentation algorithm is used according to the colour information of foreground objects. Finally, the results of the two previous steps of foreground detection are fused. The experimental results show that the method is effective and can extract relatively complete foreground objects of pigs in complex scenes. These complex scenes include light changes, the influence of ground urine stains, water stains, manure, and other sundries, pigs' slow movement patterns, and varying colours of foreground objects. The average foreground detection rate is approximately 92%. The experimental results set the foundation for further exploration of individual identification of group-housed pigs, their behaviour analysis, and other objectives.


      PubDate: 2014-07-27T19:03:35Z
       
  • Vis/NIR spectroscopic measurement of selected soil fertility parameters of
           Cuban agricultural Cambisols
    • Abstract: Publication date: September 2014
      Source:Biosystems Engineering, Volume 125
      Author(s): Ahmed Chacón Iznaga , Miguel Rodríguez Orozco , Edith Aguila Alcantara , Meilyn Carral Pairol , Yanet Eddith Díaz Sicilia , Josse de Baerdemaeker , Wouter Saeys
      The conventional methods frequently used in Cuba to determine some fertility parameters important for sugarcane production, such as organic matter (OM), available phosphorus (P) and potassium (K2O), are difficult, costly, and time-consuming procedures. This study was undertaken to build and validate Visible/Near Infrared Reflectance (Vis/NIR) calibration models of these parameters at landscape level and within a field, by taking into consideration their correlation coefficients with the OM. The parameters P and K2O, which are not spectrally active in the Vis/NIR range should be better predicted when are highly correlated with OM. Also, the wavelength intervals to simplify this methodology were selected. Samples were air-dried before scanning using a diode array spectrophotometer covering the wavelength range from 399 to 1697 nm. The regression models were built by using the linear multivariate regression method Partial Least Squares (PLS), and the nonlinear multivariate regression methods Support Vector Machines (SVM) and Locally Weighted Regression (LWR). At landscape level the best correlations between soil spectra and OM (0.90 ≤ R 2 ≤ 0.93; 0.12 ≤ RMSEP≤0.14) were obtained with LWR, followed by K2O with LWR (0.77 ≤ R 2 ≤ 0.79; 3.47 ≤ RMSEP≤3.62), Olsen P (0.69 ≤ R 2 ≤ 0.81; 0.27 ≤ RMSEP≤0.35) and Oniani P (0.64 ≤ R 2 ≤ 0.65; 3.31 ≤ RMSEP≤3.61) both with SVM. Also, the nonlinear regression models gave the best results within a field. The higher values for OM (R 2 = 0.92; RMSEP = 0.14) and Olsen P (0.68 ≤ R 2 ≤ 0.83; 0.27 ≤ RMSEP≤0.34) were observed with SVM, while for K2O (0.16 ≤ R 2 ≤ 0.63; 5.13 ≤ RMSEP≤5.88), and Oniani P (0.70 ≤ R 2 ≤ 0.72; 2.32 ≤ RMSEP≤2.52) were obtained with LWR. The soil fertility parameters studied at landscape level and within a field were best estimated by using nonlinear regression models.


      PubDate: 2014-07-27T19:03:35Z
       
  • Vegetation segmentation robust to illumination variations based on
           clustering and morphology modelling
    • Abstract: Publication date: September 2014
      Source:Biosystems Engineering, Volume 125
      Author(s): Xiaodong Bai , Zhiguo Cao , Yu Wang , Zhenghong Yu , Zhu Hu , Xuefen Zhang , Cuina Li
      Vegetation segmentation from images is an essential issue in the application of computer vision in agriculture. In this paper, we present a new vegetation segmentation method based on Particle Swarm Optimisation (PSO) clustering and morphology modelling in CIE L ∗ a ∗ b ∗ colour space. At the off-line learning stage, a new method is put forward to determine the clustering number. Secondly, the tools of morphological dilation and erosion are employed to establish the vegetation colour model. At the online segmentation stage, the PSO-based k-means is used to cluster the vegetation image into vegetation classes and non-vegetation classes. Afterwards, the established colour model is used to distinguish the vegetation classes and give the segmentation result. In the experiments, the proposed method was applied to segment 200 smaller regions of the full camera images of rice and 100 smaller regions of the full camera images of cotton. The means of segmentation qualities reached 88.1% and 91.7% respectively. Moreover, the proposed method was compared with three well-known vegetation segmentation methods and two skin segmentation methods. Experiments demonstrate that the proposed method yielded the highest mean of segmentation qualities and lowest standard deviations of segmentation qualities. In addition, the vegetation colour models built with different structuring element types are analysed.


      PubDate: 2014-07-27T19:03:35Z
       
  • Within-row spacing sensing of maize plants using 3D computer vision
    • Abstract: Publication date: September 2014
      Source:Biosystems Engineering, Volume 125
      Author(s): Akash D. Nakarmi , Lie Tang
      Within-row plant spacing plays an important role in uniform distribution of water and nutrients among plants which affects the final crop yield. While manual in-field measurements of within-row plant spacing is time and labour intensive, little work has been done on an alternative automated process. We have attempted to develop an automatic system making use of a state-of-the-art 3D vision sensor that accurately measures within-row maize plant spacing. Misidentification of plants caused by low hanging canopies and doubles were reduced by processing multiple consecutive images at a time and selecting the best inter-plant distance calculated. Based on several small scale experiments in real fields, our system has been proven to measure the within-row maize plant spacing with a mean and standard deviation error of 1.60 cm and 2.19 cm, and a root mean squared error of 2.54 cm, respectively.


      PubDate: 2014-07-27T19:03:35Z
       
  • Water and nitrogen budgets under different production systems in Lisbon
           urban farming
    • Abstract: Publication date: September 2014
      Source:Biosystems Engineering, Volume 125
      Author(s): Maria R. Cameira , Sara Tedesco , Teresa E. Leitão
      Public concern is growing over soil and groundwater contamination from the use of agrochemicals in urban farming. Heavily used nitrogen (N) fertilisers are converted to nitrates that can be a health hazard. In this study, water and N budgets over a 1-year period are presented for typical urban vegetable gardens in Lisbon. A conceptual analysis supported by an integrated methodology of field experiments and modelling identified the N surpluses associated with conventional and organic gardens. It is concluded that the gardening systems are continuously cropped using high N and water application rates. For all of the case-study allotments, the N inputs, mainly from organic amendments with diverse N release rates, were higher than the crop uptake generating surpluses that were lost by different processes. On one study site a drainage flux of 280 mm yr−1 was calculated, with a mean concentration of 295 mg NO3 − l−1. On another site N accumulated in the lower soil depths at a rate of 420 kg NO3 − ha−1 yr−1. The cumulative impact of N surpluses on the environment and human health must be considered. To minimise adverse impacts, we propose the selection of organic fertilisers with N release rates close to the crop N uptake, the prevention of excess irrigation to minimise N leaching and gaseous losses and the inclusion of the non-fertiliser N sources in the fertiliser calculations. It is shown how an integrated model can be used to predict the N release dynamics from the organic fertilisers as affected by the moisture conditions.


      PubDate: 2014-07-27T19:03:35Z
       
  • Evaluation of the thermal properties of Jatropha curcas L. kernels using
           near-infrared spectroscopy
    • Abstract: Publication date: September 2014
      Source:Biosystems Engineering, Volume 125
      Author(s): Jetsada Posom , Panmanas Sirisomboon
      The determination of the thermal properties, including thermal diffusivity, thermal conductivity, and specific heat, of Jatropha curcas L. kernels was conducted using near-infrared (NIR) spectroscopy. A total of 100 samples of whole kernels from green, yellow and black fruits and oven dried kernels were scanned using a Fourier transform NIR spectrometry over the range of 1,250,000–400,000 m−1. Models correlating the spectral data and the thermal properties measured by a reference method were developed by partial least squares regression and validated by test set validation. The results showed that for thermal diffusivity, thermal conductivity at 40 °C and 100 °C and specific heat at 40 °C and 100 °C, the coefficients of determination (R 2) were 0.5968, 0.7592, 0.7509, 0.4211 and 0.6396%, respectively; the root mean square errors of prediction (RMSEP) were 1.1 × 10−6 m2 s−1, 0.0169 W m−1 °C−1, 0.0685 W m−1 °C−1, 5.88 kJ kg−1 °C−1 and 15.8 kJ kg−1 °C−1; the biases were −2.52 × 10−7 m2 s−1, 2.85 × 10−3 W m−1 °C−1, 2.52 × 10−2 W m−1 °C−1, 1.83 kJ kg−1 °C−1 and 4.69 kJ kg−1 °C−1; and the ratios of prediction to deviation (RPD) were 1.57, 2.04, 1.98, 1.28 and 1.64, respectively. These show the possibility of using NIR spectroscopy as an alternative method to estimate the properties of Jatropha kernels, especially the thermal conductivity at 40 °C and 100 °C.


      PubDate: 2014-07-27T19:03:35Z
       
  • Effect of excitation position of a handheld shaker on fruit removal
           efficiency and damage in mechanical harvesting of sweet cherry
    • Abstract: Publication date: September 2014
      Source:Biosystems Engineering, Volume 125
      Author(s): Jianfeng Zhou , Long He , Qin Zhang , Manoj Karkee
      As labour cost keeps rising and labour availability remains increasingly uncertain, growers are seeking mechanical harvesting solutions for fresh-market tree fruit production. To fulfil this need, this research aimed at assessing the effect of excitation position on fruit removal efficiency and fruit damage using a hand-held limb shaker for harvesting sweet cherry. In this study, four excitation positions were selected on each randomly selected limb of “Y” trellis cherry trees. The total number of fruit being removed from five fruiting zones of each limb and those remaining on the tree after harvesting was counted, and harvest-induced damage was assessed. Results showed that fruit removal efficiency from each zone was highly affected by the distance of the zone to the excitation position. The overall fruit removal efficiency was 84% when shaken at the lowest excitation position, and 77%, 51% and 72% respectively as the excitation position moved up the limbs. The fruit damage rates from low to high excitation positions were 20%, 28%, 20% and 23%, which was approximately 10% higher than that of handpicked fruit. No significant difference was found in the fruit damage rate when comparing different excitation positions. It was observed that the fruit removal efficiency may reach up to 97% when the limbs were excited at both the lowest and the highest excitation positions, and adopting such an excitation method could lead to a high fruit removal efficiency with not much increase in fruit damage.


      PubDate: 2014-07-27T19:03:35Z
       
  • Specification and implementation of a continuous microwave-assisted system
           for paste malaxation in an olive oil extraction plant
    • Abstract: Publication date: September 2014
      Source:Biosystems Engineering, Volume 125
      Author(s): Alessandro Leone , Antonia Tamborrino , Roberto Romaniello , Riccardo Zagaria , Erika Sabella
      An industrial prototype continuous microwave-assisted system (MWS) to condition olive paste was specified, built and implemented as an industrial process. The developed system was tested to assess its performance during implementation in an industrial olive oil extraction plant. The extraction efficiency of the olive oil plant was investigated for different operating conditions of the MWS and compared with conventional methods to condition the olive paste. The results indicate that exposing the olive paste to microwaves determines the thermal and non-thermal effects that influence the coalescence phenomena and the extraction efficiency. The experiments showed the feasibility of the continuous microwave-assisted prototype and great the potential to become an alternative technique to effectively condition olive paste. The MWS removes the limitations of the batch malaxation process and produces an olive oil extraction process that is truly continuous.


      PubDate: 2014-07-27T19:03:35Z
       
  • Relaxation behaviour of Jatropha curcas L. bulk seeds under compression
           loading
    • Abstract: Publication date: September 2014
      Source:Biosystems Engineering, Volume 125
      Author(s): David Herak , Abraham Kabutey , Michal Petru , Petr Hrabe , Petr Lepsik , Satya Simanjuntak
      The relaxation behaviour of Jatropha curcas L. bulk seeds, expressed as the dependency of compressive force in relation to time, was determined for deformations 45, 50, 55, 60 and 65mm respectively from Jatropha bulk seed of initial pressing height 80mm using the pressing vessel diameter 60mm. The normalised force, the rate of normalised force and the second derivative of normalised force, all versus relaxation time, were described for different deformations of Jatropha bulk seeds. It was observed that at the beginning of the relaxation process the normalised force at the oil point produced minimal amount suggesting that the oil point can be determined directly from the relaxation process which is also dependent on the rate and second derivative of the normalised force. However, the oil point of Jatropha bulk seeds can equally be determined by observation of the relaxation process. The dependency of compressive force versus relaxation time of Jatropha bulk seeds for different deformations showed a linear dependency within 2s of relaxation time and after 10s of the relaxation process, the rate of normalised force was constant and the relaxation process showed no internal dynamic forces and stresses on the bulk seeds. From observations after 100s the whole relaxation process of Jatropha bulk seeds was completed.


      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
       
  • Non-contact, motion-tolerant measurements of chicken (Gallus gallus)
           embryo heart rate (HR) using video imaging and signal processing
    • Abstract: Publication date: September 2014
      Source:Biosystems Engineering, Volume 125
      Author(s): Ali Youssef , Stefano Viazzi , Vasileios Exadaktylos , Daniel Berckmans
      The chicken embryo provides an excellent model organism for physiological and developmental biology studies. The chick chorioallantoic membrane (CAM) is widely used to study angiogenesis and vasculogenesis in primary tumour growth. The cardiovascular system is the first organ system to form and function in the developing embryo. Heart rate (HR) is deemed to be an important physiological parameter in such studies. The heart rate of the developing embryo can be very informative in developmental studies of cardiac rhythm. Many studies have considered developing techniques to measure avian embryonic heart rate from incubated eggs. However, the existing techniques disturb the incubation process and/or are sensitive to embryonic motion. A novel non-contact, semi-invasive, and motion-tolerant technique to measuring embryonic heart rate from chicken eggs using video imaging and signal processing is described and implemented in this paper. The technique is based on videos captured from incubated eggs to recover heart rate signals. Heart rate is estimated using frequency analysis techniques and the values obtained are in agreement with results from the literature. The technique proposed in this paper provides a real-time approach to monitoring developmental embryonic heart rate. Also it can provide a promising technique for monitoring the developing vasculature in primary tumour growth.


      PubDate: 2014-07-27T19:03:35Z
       
  • Editorial Board
    • Abstract: Publication date: July 2014
      Source:Biosystems Engineering, Volume 123




      PubDate: 2014-07-27T19:03:35Z
       
  • Thank you to reviewers
    • Abstract: Publication date: July 2014
      Source:Biosystems Engineering, Volume 123




      PubDate: 2014-07-27T19:03:35Z
       
  • Integrated modelling for agricultural policies and water resources
           planning coordination
    • Abstract: Publication date: Available online 27 June 2014
      Source:Biosystems Engineering
      Author(s): Claudio Gandolfi , Guido Sali , Arianna Facchi , Alice Tediosi , Claudia Bulgheroni , Michele Rienzner , Enrico Weber
      Pressures due to agricultural activities play a major role in the status of water resources systems. The evaluation of the effects of agricultural policies is therefore a key problem in water resource planning and management. The work presented in this paper is an attempt to include the predictable effects of the Common Agricultural Policy (CAP) of the European Union (EU) in the process of water resources planning at the basin scale prescribed by the EU Water Framework Directive (WFD). The approach is based on the combined use of three models: (i) an economic model used to predict the likely land use scenarios at the basin scale following CAP reform; (ii) a spatially distributed hydrological model for the assessment of the related irrigation water requirements; and (iii) a decision model supporting stakeholders and decision makers in the process of water resources planning. The paper presents an application to a pilot study area in Northern Italy. The results highlight how the CAP may produce an adjustment in the agricultural sector, with a shift towards more extensive land use and to a greater diversification of production. The predicted changes in land use type and distribution are shown to have significant influence on water requirements, with a generalised decrease of their amount, which may exceed 10% in some areas. In turn, the decrease of irrigation demand can be exploited to achieve a higher degree of satisfaction of other water users in the basin and can improve the attainment of the WFD objectives.


      PubDate: 2014-07-27T19:03:35Z
       
  • Satellite-based evapotranspiration of a super-intensive olive orchard:
           Application of METRIC algorithms
    • Abstract: Publication date: Available online 16 July 2014
      Source:Biosystems Engineering
      Author(s): Isabel Pôças , Teresa A. Paço , Mário Cunha , José A. Andrade , José Silvestre , Adélia Sousa , Francisco L. Santos , Luís S. Pereira , Richard G. Allen
      METRIC™ is a satellite-based surface energy balance model aimed at estimating and mapping crop evapotranspiration (ET). It has been applied to a large range of vegetation types, mostly annual crops. When applied to anisotropic woody canopies, such as olive orchards, extensions are required to algorithms for estimating the leaf area index (LAI), surface temperature, and momentum roughness length (Z om). The computation of the radiometric surface temperature needs to consider a three-source condition, thus differentiating the temperature of the canopy (T c ), of the shaded ground surface (T shadow), and of the sunlit ground surface (T sunlit). The estimation of the Z om for tall and incomplete cover is based upon the LAI and crop height using the Perrier equation. The LAI, Z om, and temperature derived from METRIC after these adjustments were tested against field collected data with good results. The application of METRIC to a two year set of Landsat images to estimate ET of a super-intensive olive orchard in Southern Portugal produced good ET estimates that compared well with ground-based ET. The analysis of METRIC performance showed a quantitative improvement of ET estimates when applying the three-source condition for temperature estimation, as well as the Z om computation with the Perrier equation. Results show that METRIC can be used operationally to estimate and mapping ET of super-intensive olive orchards aiming at improving irrigation water use and management.


      PubDate: 2014-07-27T19:03:35Z
       
  • Wine-distillery waste compost addition to a drip-irrigated horticultural
           crop of central Spain: Risk assessment
    • Abstract: Publication date: Available online 25 July 2014
      Source:Biosystems Engineering
      Author(s): María I. Requejo , María C. Cartagena , Raquel Villena , Augusto Arce , Francisco Ribas , María J. Cabello , María T. Castellanos
      The assessment of environmental effects is important before agricultural use of organic wastes, especially in irrigated agricultural areas vulnerable to nitrate pollution. A field study with melon crop was conducted during 2011 and 2012 in central Spain, using different rates of wine-distillery waste compost to quantify nitrogen (N) leaching under two regimes of irrigation. To evaluate the groundwater pollution risk associated with these practices, some environmental indices were used to determine the variation in the quality of drinking water (Impact Index (II)) and in the nitrate concentration of the groundwater (Environmental Impact Index (EII)). To combine environmental together with yield parameters, the Management Efficiency (ME) was calculated. Considering II and EII, compost addition together with adjusted irrigation (90–100% ETc) do not represent a risk to increase groundwater contamination, and, in high doses, may contribute to remove nitrate from drainage water and improve the quality of the drinking water. In contrast, applying large amounts of compost together with an excess of water (120% ETc) increased N leaching significantly and poses a higher risk of groundwater contamination. The rate corresponding to 13 t ha−1 of compost together with an efficient irrigation is sufficient to achieve the highest yield, does not exceed the maximum allowable limits established by II and EII and has an adequate ME.


      PubDate: 2014-07-27T19:03:35Z
       
  • Use of inorganic substrates and composted green waste in growing media for
           green roofs
    • Abstract: Publication date: August 2014
      Source:Biosystems Engineering, Volume 124
      Author(s): Abigail Graceson , Martin Hare , Nigel Hall , Jim Monaghan
      Inorganic substrates are used as the primary component in green roof growing media because they can provide the desired physical properties and are thought to be physically, chemically and structurally stable over time. Inorganic substrates can be amended with organic matter to help establish vegetation on green roofs but there is little information on how this affects the physical properties; dry bulk density, water holding capacity and air filled porosity; of the resulting growing medium or whether the effects are the same for all inorganic substrates. Nine crushed brick and three crushed tile substrates obtained from five UK suppliers of aggregates were amended with 30% v/v composted green waste. The physical properties of the substrates and growing media mixes were determined using the gravitational drainage technique. Amending the inorganic substrates with composted green waste significantly improved the physical properties by reducing the dry bulk density and increasing the water holding capacity. Air filled porosity of inorganic substrates decreased with addition of fine composted green waste but aeration was always adequate for plant growth and survival. This provides evidence of the beneficial effects of inclusion of composted green waste on the physical properties of inorganic substrates for green roof growing media but highlights the fact that the responses to inclusion of composted green waste may be different for different inorganic substrates or grades of substrate.


      PubDate: 2014-06-14T15:25:37Z
       
  • Effect of nano-Si2O and nano-Al2O3 on cement mortars for use in
           agriculture and livestock production
    • Abstract: Publication date: July 2014
      Source:Biosystems Engineering, Volume 123
      Author(s): Nestor León , Jordi Massana , Francisco Alonso , Amparo Moragues , Elvira Sánchez-Espinosa
      The effect of nano-silica, nano-alumina and binary combinations on surface hardness, resistance to abrasion and freeze-thaw cycle resistance in cement mortars was investigated. The Vickers hardness, the Los Angeles coefficient (LA) and the loss of mass in each of the freeze–thaw cycles to which the samples were subjected were measured. Four cement mortars CEM I 52.5R were prepared, one as control, and the other three with the additions: 5% nano-Si, 5% nano-Al and mix 2.5% n-Si and 2.5% n-Al. Mortars were tested at 7, 28 and 90 d of curing to determine compression strength, total porosity and pore distribution by mercury intrusion porosimetry (MIP) and the relationship between the CSH gel and Portlandite total by thermal gravimetric analysis (TGA). The capillary suction coefficient and an analysis by a scanning electron microscope (SEM) was made. There was a large increase in Vickers surface hardness for 5% n-Si mortar and a slight increase in resistance to abrasion. No significant difference was found between the mortars with nano-particles, whose LA was about 10.8, classifying them as materials with good resistance to abrasion. The microstructure shows that the addition of n-Si in mortars refines their porous matrix, increases the amount of hydrated gels and generates significant changes in both Portlandite and Ettringite. This produced a significant improvement in freeze–thaw cycle resistance. The effect of n-Al on mortar was null or negative with respect to freeze–thaw cycle resistance.


      PubDate: 2014-06-14T15:25:37Z
       
  • First steps to predicting pulp colour in whole melons using near-infrared
           reflectance spectroscopy
    • Abstract: Publication date: July 2014
      Source:Biosystems Engineering, Volume 123
      Author(s): María-Teresa Sánchez , Irina Torres , María-José De la Haba , Dolores Pérez-Marín
      Near-infrared reflectance spectroscopy (NIRS) technology was used for the non-destructive measurement of melon-pulp colour (a*, b*, C* and h*), one of the main indicators of ripeness and quality. A total of 432 Cantaloupe and Galia melons were used in the construction of calibration models, testing various spectral signal pretreatments and both linear and non-linear regression algorithms. The coefficient of determination (r 2) and the standard error of cross-validation (SECV) obtained for parameters a* (0.96, 2.16), b* (0.85, 3.25), C* (0.82, 3.76) and h* (0.96, 3.64) in intact fruit confirmed the a priori viability of NIRS technology with modified partial least squares (MPLS) regression for measuring melon ripeness and quality. Moreover, the application of a local algorithm improved the ability of models to predict all the internal-colour quality parameters studied. These results suggest that NIRS technology is a promising tool for monitoring ripening in melons and thus for establishing the optimal harvesting time.


      PubDate: 2014-06-14T15:25:37Z
       
  • Energy intensity and energy ratio in producing willow chips as feedstock
           for an integrated biorefinery
    • Abstract: Publication date: July 2014
      Source:Biosystems Engineering, Volume 123
      Author(s): Mariusz J. Stolarski , Michał Krzyżaniak , Józef Tworkowski , Stefan Szczukowski , Janusz Gołaszewski
      This study examined the production of willow at a commercial plantation with an area of 10.5 ha, situated in north-eastern Poland. Its aim was to evaluate the energy intensity and energy ratio of the production of chips of new willow cultivars as feedstock for an integrated biorefinery. This study emphasises the key importance of the selection of a willow cultivar for the production of willow chips and the transport distance to a biorefinery for the energy intensity of the production process and the energy ratio of the supplied biomass. The lowest energy intensity for willow chip production was achieved for the plantation of the highest-yielding cultivar (UWM 006). When the yield exceeded 86 t ha−1 of fresh biomass, the energy intensity was 0.35 GJ t−1 of fresh matter (f.m.). The energy ratio for the product at the farm gate varied depending on the cultivar and ranged from 23.9 to 10.2, for UWM 006 and UWM 155 cultivars, respectively. The distance of biomass transport to a biorefinery significantly affected the energy ratio. When chips were transported for 25 km, the energy intensity for the production of 1 t of chips increased by 3–7% compared to its value at the farm gate. The energy intensity for the longest of the analysed transport distances increased by 23–53%. The energy ratio for each cultivar decreased significantly by 3–35% with increasing transport distance. The values of energy intensity and energy ratio for UWM 006 and UWM 043 were better than those achieved in other studies.


      PubDate: 2014-06-14T15:25:37Z
       
  • Combustion characteristics and emissions of a compression ignition engine
           using emulsified jatropha biodiesel blend
    • Abstract: Publication date: July 2014
      Source:Biosystems Engineering, Volume 123
      Author(s): Hifjur Raheman , Sweeti Kumari
      An emulsified fuel containing 10% and 15% water by volume was prepared from a diesel blend with 10% Jatropha biodiesel (JB10) to evaluate the combustion characteristics of a 10.3 kW, single cylinder, 4-stroke, water cooled, direct injection (DI) diesel engine. Initially experiments were conducted to determine the required hydrophilic–lipophilic balance (HLB). The results showed that JB10 and its emulsified fuel exhibited similar combustion stages to that of diesel with no undesirable combustion features observed such as an unacceptable increase cylinder gas pressure. With increasing percentage of water, ignition delay was longer at higher engine loads. Reductions in emission of CO, CO2, HC and NO x were observed for the emulsified fuel compared to JB10. Emulsified biodiesel can be recommended for use in place of biodiesel.


      PubDate: 2014-06-14T15:25:37Z
       
  • Two-stage procedure based on smoothed ensembles of neural networks applied
           to weed detection in orange groves
    • Abstract: Publication date: July 2014
      Source:Biosystems Engineering, Volume 123
      Author(s): Joaquín Torres-Sospedra , Patricio Nebot
      The potential impacts of herbicide utilization compel producers to use new methods of weed control. The problem of how to reduce the amount of herbicide and yet maintain crop production has stimulated many researchers to study selective herbicide application. The key of selective herbicide application is how to discriminate the weed areas efficiently. We introduce a procedure for weed detection in orange groves which consists of two different stages. In the first stage, the main features in an image of the grove are determined (Trees, Trunks, Soil and Sky). In the second, the weeds are detected only in those areas which were determined as Soil in the first stage. Due to the characteristics of weed detection (changing weather and light conditions), we introduce a new training procedure with noisy patterns for ensembles of neural networks. In the experiments, a comparison of the new noisy learning was successfully performed with a set of well-known classification problems from the machine learning repository published by the University of California, Irvine. This first comparison was performed to determine the general behavior and performance of the noisy ensembles. Then, the new noisy ensembles were applied to images from orange groves to determine where weeds are located using the proposed two-stage procedure. Main results of this contribution show that the proposed system is suitable for weed detection in orange, and similar, groves.


      PubDate: 2014-06-14T15:25:37Z
       
  • Profit maximisation algorithm including the loss of yield due to uncertain
           weather events during harvest
    • Abstract: Publication date: July 2014
      Source:Biosystems Engineering, Volume 123
      Author(s): Lazar Savin , Snežana Matić-Kekić , Nebojša Dedović , Mirko Simikić , Milan Tomić
      A general LP model and a profit maximisation algorithm for harvesting during an agrotechnical period have been created. The profit was based on the crop yields on a primary farm and the rental of combines to surrounding farms for their harvests. In contrast to the standard approach, the use of integer variables was avoided in the proposed model. The objective function included the risk of yield reduction due to bad weather conditions and the deliberate extension of the harvest on the primary farm, with the aim of higher profits from combine rentals. The model involved two conflicting criteria: the minimisation of risk during harvest on the primary farm and the maximisation of combine rentals; both of these aims were successfully incorporated into the objective function. The operational reliability of combines and tractors was taken into account in model creation. A general model was applied to a large farm (1380 ha) during a period of harvest and transport of oilseed rape, wheat and winter barley into storage (June–July). The farm that was considered is equipped with enough machinery to harvest other farms and on its own parcels simultaneously.


      PubDate: 2014-06-14T15:25:37Z
       
  • Simulation of soya bean flow in mixed-flow dryers using DEM
    • Abstract: Publication date: July 2014
      Source:Biosystems Engineering, Volume 123
      Author(s): Oleg A. Khatchatourian , Manuel O. Binelo , Rodolfo F. de Lima
      Soya bean movement in mixed-flow dryers (MFDs) is explored. A three-dimensional model of soya beans flow was developed applying the discrete element method (DEM) implementation of the Yade software package. To validate the developed model the experiments of the soya beans discharge in small MFD were carried out and the results compared with simulations. Considering the soya bean seeds as single spheres, and using the values of the principal material properties (Poisson coefficient, Young modulus, fraction angle and rolling stiffness) from the literature, satisfactory agreement was obtained between simulated and experimental results with a damping factor value of 0.05. Simulations of continuous flow detected significant non-uniformity in particle velocity and residence time.


      PubDate: 2014-06-14T15:25:37Z
       
  • A novel intelligent control system for flue-curing barns based on
           real-time image features
    • Abstract: Publication date: July 2014
      Source:Biosystems Engineering, Volume 123
      Author(s): Juan Wu , Simon X. Yang , Fengchun Tian
      Most intensive tobacco curing systems are manually operated requiring the curers to frequently observe the status of tobacco leaves and in order to achieve the desired temperature and relative humidity, curers adjust the setpoint values of dry and wet bulb temperatures and the time to change to the next setpoints. Control is therefore subjective and it is difficult to maintain consistent high quality curing. A novel intelligent control system based on the real-time image processing of the tobacco leaves images to monitor the status of the tobacco leaves was developed. A neural network based approach was designed to identify the setpoints for the dry and wet bulb temperatures, and the time to change to the next setpoints. Inputs were 12 extracted image features obtained from an image processing algorithm and the measured dry and wet bulb temperatures in the barn. Without any manual intervention by curers, the developed intelligent control system achieved real-time monitoring and management of the curing process. The effectiveness of the developed intelligent control system was demonstrated by simulation and experiment.


      PubDate: 2014-06-14T15:25:37Z
       
  • Anaerobic digestion of pig manure fibres from commercial pig slurry
           separation units
    • Abstract: Publication date: July 2014
      Source:Biosystems Engineering, Volume 123
      Author(s): Ole Thygesen , Jin M. Triolo , Sven G. Sommer
      The composition of manure fibres (MF) from 17 commercially separated pig slurries and seven raw pig slurries were characterised in terms of dry matter (DM), volatile solids (VS), protein, hemicellulose, cellulose and lignin. The average lignocellulose concentration in manure fibres and pig slurries was 790 and 370 g kg−1 [VS] respectively. Biochemical methane potential was ascertained after 60 days, revealing a trend in biochemical methane potential between the different separation technologies used: pig slurry > shaking filter and screw press combined ≈ decanter centrifuge > flocculation, belt and screw press combined ≈ screw press. The maximum methane yield of manure fibres from decanter centrifuges and the combined shaking filter and screw press was approximately 330 l [CH4] kg−1 [VS] at standard temperature and pressure (STP), while manure fibres from a screw press and a combination of belt press and screw press on average produced approximately 220 l [CH4] kg−1 [VS]. Initial methane production can be described using a first-order kinetic model. The average rate constant for manure fibres was 0.030 d−1 and for pig slurry 0.071 d−1, showing that pig slurry is digested much faster than manure fibres.


      PubDate: 2014-06-14T15:25:37Z
       
  • Long term irrigation with treated wastewater (TWW) and soil sodification
    • Abstract: Publication date: Available online 2 June 2014
      Source:Biosystems Engineering
      Author(s): Guy J. Levy , Pinchas Fine , Dina Goldstein , Asher Azenkot , Avraham Zilberman , Amram Chazan , Tzfrir Grinhut
      Use of treated wastewater (TWW) for irrigation has grown noticeably in recent years, especially in arid and semi-arid regions. The sodium adsorption ratio (SAR) in TWW is considerably higher than that in its fresh water of origin. Recently, there is evidence showing that subsurface (depth >30 cm) exchangeable sodium percentage (ESP) levels in Israeli orchards may reach 6–9 which is higher than expected following long-term irrigation with TWW having SAR <5. Our objectives were to (i) determine the ESP in soil profiles of orchards exposed to irrigation with TWW, and (ii) examine the relationships between the SAR of the irrigation water, the SAR of the soil solution and the ESP of the studied soils. Soil samples were taken from different depths (up to 120 cm) in orchards grown on two different soil types that had been irrigated for >10 years with TWW. In each soil sample non-adjusted SAR and adjusted SAR (SARadj) of the saturated paste and ESP were determined. In all sampled sites except one, accumulation of adsorbed sodium in the soil subsurface was noted. The obtained ESP levels were higher than those expected based on the SAR of the TWW. A satisfactory agreement was noted between ESP data and the non-adjusted SAR and SARadj of the soil solution. These observations suggest that a chemical equilibrium exists between the soil exchange phase and the soil solution and that the properties of the latter were not always dictated by those of the irrigation water.


      PubDate: 2014-06-14T15:25:37Z
       
  • Editorial Board
    • Abstract: Publication date: June 2014
      Source:Biosystems Engineering, Volume 122




      PubDate: 2014-06-14T15:25:37Z
       
  • Early detection of mechanical damage in mango using NIR hyperspectral
           images and machine learning
    • Abstract: Publication date: June 2014
      Source:Biosystems Engineering, Volume 122
      Author(s): Nayeli Vélez Rivera , Juan Gómez-Sanchis , Jorge Chanona-Pérez , Juan José Carrasco , Mónica Millán-Giraldo , Delia Lorente , Sergio Cubero , José Blasco
      Mango fruit are sensitive and can easily develop brown spots after suffering mechanical stress during postharvest handling, transport and marketing. The manual inspection of this fruit used today cannot detect the damage in very early stages of maturity and to date no automatic tool capable of such detection has been developed, since current systems based on machine vision only detect very visible damage. The application of hyperspectral imaging to the postharvest quality inspection of fruit is relatively recent and research is still underway to find a method of estimating internal properties or detecting invisible damage. This work describes a new system to evaluate mechanically induced damage in the pericarp of ‘Manila’ mangos at different stages of ripeness based on the analysis of hyperspectral images. Images of damaged and intact areas of mangos were acquired in the range 650–1100 nm using a hyperspectral computer vision system and then analysed to select the most discriminating wavelengths for distinguishing and classifying the two zones. Eleven feature-selection methods were used and compared to determine the wavelengths, while another five classification methods were used to segment the resulting multispectral images and classify the skin of the mangos as sound or damaged. A 97.9% rate of correct classification of pixels was achieved on the third day after the damage had been caused using k-Nearest Neighbours and the whole spectra and the figure dropped to 91.4% when only the most discriminant bands were used.


      PubDate: 2014-06-14T15:25:37Z
       
  • Olive oil quality improvement using a natural sedimentation plant at
           industrial scale
    • Abstract: Publication date: June 2014
      Source:Biosystems Engineering, Volume 122
      Author(s): Giuseppe Altieri , Giovanni C. Di Renzo , Francesco Genovese , Antonella Tauriello , Maurizio D'Auria , Rocco Racioppi , Licia Viggiani
      Olive oil extraction is mainly carried out using continuous extraction by decanter centrifuge with efficiency of approximately 80–90%. After centrifugal extraction, olive oil is generally cleaned using a vertical disc stack centrifuge separator, which is suspected of being the major cause of decreased final olive oil quality. Experiments were carried out at industrial scale to compare the olive oil properties after improved processes of sedimentation (Sedoil) or centrifugation (Cenoil) with respect to raw olive oil obtained at the decanter exit (Control). Peroxide, polyphenol, chlorophyll, carotenoid, turbidity and K232 average values were significantly different between Sedoil and Cenoil, which confirmed that the use of disc stack centrifuges represents an important source of oxidative reactions. Analysis showed that storage time dramatically affects the oxidation level of the olive oil. All parameters used to monitor the oxidation level (i.e., free acidity, peroxide value and K232) increased after 180 d of storage, and the content of natural antioxidants and pigments decreased as expected. The residual presence of water during long-term storage represented the most important source of oxidation, and an effective cleaning operation is necessary to preserve oil quality during its storage life. The analyses performed using 1H and 13C NMR showed that Sedoil was more similar in composition to Control than to Cenoil. The use of sedimentation plant allows the employment of the disk stack centrifuge to be reduced improving both energy saving and the quality of clean olive oil.


      PubDate: 2014-06-14T15:25:37Z
       
  • Effects of cover optical properties on screenhouse radiative environment
           and sweet pepper productivity
    • Abstract: Publication date: June 2014
      Source:Biosystems Engineering, Volume 122
      Author(s): Evangelini Kitta , Alain D. Baille , Nikolaos Katsoulas , Nikolaos Rigakis , Maria M. González-Real
      The effects of cover optical properties on screenhouse radiative environment and sweet pepper productivity were investigated in a Mediterranean climate (Eastern Greece) under three covering materials (i) a pearl insect-proof screen (IP-78), (ii) a white insect proof screen (IP-59) and (iii) a green shade-screen (GS-62) with values of the transmittance to photosynthetically active radiation (τ PAR) of 78%, 59% and 62%, respectively. All screens induced impoverishment in the blue wavelength band (B, 400–500 nm) and enrichment in near-infrared broadband (NIR, 700–1100 nm) with respect to photosynthetically active radiation (PAR) (400–700 nm), and modified photomorphogenetic parameters such as the ratio R:FR (Red:Far-Red). From a 2-year agronomic survey, it was found that the lowest performance in terms of crop productivity was observed in the open field, and the highest under the IP-78 screenhouse. At final harvest, aboveground dry biomass and total yield of screenhouse crops were linearly and positively correlated with τ PAR, while plant height was negatively correlated with the ratio R:FR. The results suggested that (i) the more diffuse radiation regime prevailing under screenhouse is likely to be at the root of the higher crop performances observed under the screenhouses and (ii) τ PAR and R:FR are likely to act synergistically in light capture. We conclude that both changes in transmittance and light quality must be accounted for when analysing productivity and yield regulation of screenhouse-grown crops. From a practical point of view, a shading factor no higher than 20% is recommended for sweet pepper cropping under Mediterranean conditions similar to those of this study.


      PubDate: 2014-06-14T15:25:37Z
       
  • Numerical simulations and experimental measurements on the distribution of
           air and drying of round hay bales
    • Abstract: Publication date: June 2014
      Source:Biosystems Engineering, Volume 122
      Author(s): Franz D. Román , Oliver Hensel
      The artificial drying of round bales offers the possibility to consistently produce quality hay by reducing field curing time and leaf shattering. Air distribution in the bale must be appropriate in order to achieve a uniform and efficient drying process. The air distribution and drying of four designs of round bale dryer were simulated using computational fluid dynamics. A round bale was modelled as a cylindrical porous media having a soft core. Bales were modelled both as being perfectly formed and as having a lower density close to their circular faces. Simulations showed that the simplest dryer design in which air enters the bale through one end, provides a deficient air distribution and inadequate drying, even when the bale is perfectly formed. Other designs studied showed, to varying degrees, an improved air distribution and drying uniformity. Simulations of a design in which an axial void is created in the bale centre, produced an optimal situation where the air and the drying front moves radially from the centre outwards. Conveying of air through both bale ends also contributed significantly to flow and drying uniformity. However, simulations for bales with a deficient density profile, as often found in practice, showed important distortions in the air distribution negatively affected drying. Therefore the uniformity of bale dry matter density is a determinant for the successful operation of any dryer. Additional efforts must be invested in the field to produce more uniform bales, particularly during raking and baling.


      PubDate: 2014-04-28T22:59:40Z
       
  • Prediction of surface temperature of figs during infrared heating and its
           effect on the quality
    • Abstract: Publication date: June 2014
      Source:Biosystems Engineering, Volume 122
      Author(s): Vipavee Trivittayasil , Fumihiko Tanaka , Daisuke Hamanaka , Toshitaka Uchino
      Fresh figs have a short shelf-life due to a fast softening rate and fungal spoilage. Infrared heating treatment as a surface decontamination technique could be applied to the ostiole, where most mould growth is observed. However, the quality of fresh fruits could be degraded if the heat treatment is too severe. The objective of this study is to find the optimal trade-off between a fungal decay reduction and a fruit quality. Figs were treated with infrared heating until they reached maximum temperatures of 50 °C, 60 °C and 70 °C. A heat transfer model was employed to calculate the treatment time required for each treatment group. Quality assessment was performed after six days of storage at 7 °C. At the lowest heating treatment group of 50 °C, a suppression of fungal development was achieved without a significant heat injury.


      PubDate: 2014-04-28T22:59:40Z
       
  • Effects of acidification during storage on emissions of methane, ammonia,
           and hydrogen sulfide from digested pig slurry
    • Abstract: Publication date: June 2014
      Source:Biosystems Engineering, Volume 122
      Author(s): Kaiying Wang , Dandan Huang , Hongchuang Ying , Haojie Luo
      The effects of acidification reduction on methane (CH4), ammonia (NH3) and hydrogen sulphide (H2S) emissions from digested pig slurry during storage were investigated. Pilot-scale experiments designed with three different pH levels including one control and two acidified treatments were conducted. Digested pig slurry was stored and tested in nine mechanically ventilated reactors. An online and continuous monitoring system was used to acquire gas emissions data during the whole storage period. Temperatures and pH in digested slurry were continuously measured with sensors. Off-gas from the reactors and air from room environment were sampled alternately then supplied to gas analysers for CH4 and H2S determination. Headspace NH3 from the 9 reactors were regularly sampled by an air sampling instrument and then determined for concentration by spectrophotometer. The study found that digested pig slurry characteristics still didn't satisfy the national standards after 95 days treatments. Both temperature and pH were crucial factors to influence CH4 and NH3 emissions from digested pig slurry. In the control group (Gn) CH4 and H2S emissions mainly occurred in the first 20 days and 12 days, respectively; while no predictable NH3 emission patterns were found in the experiment. Comparing with Gn, adjustment of initial pH to 5.5 significantly reduced CH4 emissions by 80.8% and NH3 emissions by 40.2%, but increased H2S emissions by 11,324% (average increasing emission flux was 4.1 μg m−2 min−1). Acidification with pH adjusted to 6.5 reduced CH4 emissions by 31.2%, but did not affect NH3 and H2S emissions significantly.


      PubDate: 2014-04-28T22:59:40Z
       
  • Moisture transport properties of lime–hemp concrete determined over
           the complete moisture range
    • Abstract: Publication date: June 2014
      Source:Biosystems Engineering, Volume 122
      Author(s): Paulien Strandberg-de Bruijn , Peter Johansson
      To determine the durability of a lime–hemp concrete (LHC) wall and its resistance to driving rain, moisture conditions inside the wall have to be modelled. As model input, moisture transport properties were determined. Two LHC mixes were studied. Cup tests provided moisture diffusivity results at relative humidity (RH) values up to 95%. Capillary water uptake tests provided results for the interval 95–100% RH by means of curve fitting and the simulation tool JAM-KAP. A mix containing more lime showed higher moisture diffusivity at relative humidity >95%.


      PubDate: 2014-04-28T22:59:40Z
       
  • Optimised hydrodynamic parameters for the design of photobioreactors using
           computational fluid dynamics and experimental validation
    • Abstract: Publication date: June 2014
      Source:Biosystems Engineering, Volume 122
      Author(s): Jessie Pascual P. Bitog , In-Bok Lee , Hee-Mock Oh , Se-Woon Hong , Il-Hwan Seo , Kyeong-Seok Kwon
      A numerical simulation using computational fluid dynamics (CFD) was utilised to investigate the flow hydrodynamics of cylindrical bubble column type photobioreactors (PBRs) with a 30l culture medium. To establish the reliability of the simulation study, the CFD model was validated using particle image velocimetry (PIV) computed data under various air flow rates. There were 32 simulation cases for the study comprising two PBR designs, four air flow rates and four nozzle size diameters. Hydrodynamic analyses such as % volume of dead zones, average circulation time and turbulence intensity inside the simulated PBRs were evaluated. Results have shown that the most appropriate PBR for microalgae cultivation was a design with internal baffle and an extended cone-shaped bottom section. In addition, the recommended nozzle diameter was found to be 10 mm and a minimum air flow rate of 0.10 vvm. To eliminate dead zones inside the PBR, the flow rate can be slightly increased but should not exceed 0.15 vvm. Practical evaluation through laboratory experiments has further confirmed the results of the study where the biomass concentration of Chlorella vulgaris from the proposed PBR was significantly higher compared to the standard PBR design. Based on the numerical investigation and practical evaluation, the improved PBR can be seen to be more effective in culturing microalgae particularly for larger scale mass production.


      PubDate: 2014-04-28T22:59:40Z
       
  • Prototype semi-transparent photovoltaic modules for greenhouse roof
           applications
    • Abstract: Publication date: June 2014
      Source:Biosystems Engineering, Volume 122
      Author(s): Akira Yano , Mahiro Onoe , Josuke Nakata
      Improved energy efficiency and the increased use of renewable energy are important objectives for sustainable greenhouse crop production. Two prototypes of semi-transparent-bifacial photovoltaic modules intended for greenhouse roof applications were developed. A module (PV1) using 1500 spherical solar microcells (1.8 mm diameter, crystalline silicon) with 15.4 cells cm−2 density in 108 mm × 90 mm area was produced. Thirty-nine percent of the area was covered with the cells. The remaining 61% was transparent to allow the most sunlight to enter the greenhouse for promising plant photosynthesis. Similarly, a module (PV2) was made using 500 cells with 5.1 cells cm−2 density. Thirteen percent of the area of this module was covered with the cells. The peak power output was 540 mW when the PV1 module was irradiated with 1213 W m−2 sunlight coming directly from the sky and via ground reflection. The peak power output was 202 mW when the PV2 module was irradiated with 1223 W m−2 sunlight. The conversion efficiencies from sunlight energy irradiated on the 108 mm × 90 mm area into electrical energy were 4.5% for the PV1 module and 1.6% for the PV2 module. Calculations of the annual electrical energy production per unit greenhouse land area indicated that these modules are potentially suitable for greenhouses in high-irradiation regions where electricity production could be high and winter demand low.
      Graphical abstract image

      PubDate: 2014-04-28T22:59:40Z
       
  • Drip vs. surface irrigation: A comparison focussing on water saving and
           economic returns using multicriteria analysis applied to cotton
    • Abstract: Publication date: June 2014
      Source:Biosystems Engineering, Volume 122
      Author(s): Hanaa M. Darouich , Celestina M.G. Pedras , José M. Gonçalves , Luís S. Pereira
      This study explores the use of drip and surface irrigation decision support systems to select among furrow, border and drip irrigation systems for cotton, considering water saving and economic priorities. Data refers to farm field observations in Northeast of Syria. Simulation of drip irrigation was performed with MIRRIG model for various alternatives: double and single row per lateral, emitter spacing of 0.5 and 0.7 m, six alternative pipe layouts and five self-compensating and non-compensating emitters. Furrow and border irrigation alternatives were designed and ranked with the SADREG model, considering lasered and non-lasered land levelling, field lengths of 50–200 m and various inflow discharges. A multicriteria analysis approach was used to analyse and compare the alternatives based upon economic and water saving criteria. Results for surface irrigation indicate a slight advantage for long non-lasered graded furrows; non-lasered alternatives were selected due to economic considerations. For drip irrigation, the best ranking is for systems having lower costs, mainly with double rows per lateral and larger emitter spacing. Comparing surface and drip irrigation systems, despite low cost, drip alternatives may lead to 28–35% water saving relative to improved graded furrows, and increase water productivity from 0.43 kg m−3 to 0.61 kg m−3, surface irrigation provides higher farm returns. Drip irrigation is selected only when high priority is assigned to water saving. Deficit irrigation does not change this pattern of results. Apparently, adopting drip irrigation requires appropriate economic incentives to farmers, changes in the structure of production costs and increased value of production.


      PubDate: 2014-04-28T22:59:40Z
       
 
 
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