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  Subjects -> AGRICULTURE (Total: 653 journals)
    - AGRICULTURAL ECONOMICS (70 journals)
    - AGRICULTURE (438 journals)
    - CROP PRODUCTION AND SOIL (84 journals)
    - DAIRYING AND DAIRY PRODUCTS (24 journals)
    - POULTRY AND LIVESTOCK (37 journals)

AGRICULTURE (438 journals)                  1 2 3 4 5 | Last

Acta agriculturae Slovenica     Open Access   (4 followers)
Acta Agrobotanica     Open Access   (2 followers)
Acta Agronomica Hungarica     Full-text available via subscription   (1 follower)
Acta Agronomica Sinica     Full-text available via subscription   (6 followers)
Acta Scientiarum. Animal Sciences     Open Access  
Acta Scientiarum. Technology     Open Access  
Acta Technologica Agriculturae     Open Access  
Advances in Agriculture & Botanics     Open Access   (10 followers)
Advances in Agriculture, Sciences and Engineering Research     Open Access   (10 followers)
Advances in Agronomy     Full-text available via subscription   (12 followers)
Advances in Life Science and Technology     Open Access   (4 followers)
AFBM Journal     Open Access  
Africa Development     Open Access   (2 followers)
Africa Research Bulletin: Political, Social and Cultural Series     Hybrid Journal   (6 followers)
African Journal of Agricultural Research     Open Access  
African Journal of Food Science     Open Access   (1 follower)
African Journal of Food, Agriculture, Nutrition and Development     Open Access  
African Journal of Horticultural Science     Open Access   (2 followers)
African Journal of Range and Forage Science     Hybrid Journal   (5 followers)
African Journal of Sustainable Development     Full-text available via subscription   (2 followers)
Agribusiness : an International Journal     Hybrid Journal   (5 followers)
Agricultura Tecnica     Open Access   (5 followers)
Agricultura Tropica et Subtropica     Open Access   (1 follower)
Agricultural Advances     Open Access   (3 followers)
Agricultural and Food Science     Open Access   (14 followers)
Agricultural Economics     Hybrid Journal   (43 followers)
Agricultural History     Full-text available via subscription   (97 followers)
Agricultural Research     Hybrid Journal   (2 followers)
Agricultural Science     Full-text available via subscription   (5 followers)
Agricultural Sciences     Open Access   (7 followers)
Agricultural Sciences in China     Full-text available via subscription   (3 followers)
Agricultural Systems     Hybrid Journal   (19 followers)
Agricultural Water Management     Hybrid Journal   (13 followers)
Agriculture     Open Access   (4 followers)
Agriculture & Food Security     Open Access   (8 followers)
Agriculture (Poľnohospodárstvo)     Open Access   (1 follower)
Agriculture and Agricultural Science Procedia     Full-text available via subscription  
Agriculture and Human Values     Hybrid Journal   (10 followers)
Agriculture, Ecosystems & Environment     Hybrid Journal   (29 followers)
Agriprobe     Full-text available via subscription  
Agrivita : Journal of Agricultural Science     Open Access   (4 followers)
Agro-Science     Full-text available via subscription  
Agroalimentaria     Open Access   (1 follower)
Agrociencia     Open Access   (2 followers)
Agrokémia és Talajtan     Full-text available via subscription   (2 followers)
Agronomía Colombiana     Open Access   (1 follower)
Agronomía Costarricense     Open Access   (2 followers)
Agronomía Mesoamericana     Open Access   (1 follower)
Agronomie Africaine     Full-text available via subscription  
Agronomy     Open Access   (8 followers)
Agrosearch     Open Access  
AI & Society     Hybrid Journal   (2 followers)
Alinteri Zirai Bilimler Dergisi : Alinteri Journal of Agricultural Sciences     Open Access  
Ambiência     Open Access  
Ambiente & Agua : An Interdisciplinary Journal of Applied Science     Open Access   (1 follower)
American Journal of Agricultural and Biological Sciences     Open Access   (9 followers)
American Journal of Botany     Full-text available via subscription   (13 followers)
American Journal of Economics and Sociology     Hybrid Journal   (18 followers)
American Journal of Potato Research     Hybrid Journal   (2 followers)
Anais da Academia Brasileira de Ciências     Open Access   (2 followers)
Annales UMCS, Agricultura     Open Access  
Annales UMCS, Horticultura     Full-text available via subscription  
Annals of Agricultural and Environmental Medicine     Open Access   (1 follower)
Annals of Agricultural Sciences     Open Access   (1 follower)
Annual Review of Resource Economics     Full-text available via subscription   (10 followers)
APCBEE Procedia     Partially Free   (2 followers)
Applied Economics Letters     Hybrid Journal   (18 followers)
Applied Financial Economics Letters     Hybrid Journal   (4 followers)
Arboricultural Journal : The International Journal of Urban Forestry     Hybrid Journal   (5 followers)
Archivos de Zootecnia     Open Access  
Arquivos do Instituto Biológico     Open Access  
Arthropod-Plant Interactions     Hybrid Journal   (1 follower)
Asian Economic Papers     Hybrid Journal   (3 followers)
Asian Journal of Agricultural Research     Open Access   (2 followers)
Asian Journal of Plant Sciences     Open Access   (1 follower)
Australian Cottongrower, The     Full-text available via subscription   (1 follower)
Australian Economic Papers     Hybrid Journal   (5 followers)
Australian Forest Grower     Full-text available via subscription   (2 followers)
Australian Forestry     Full-text available via subscription   (4 followers)
Australian Grain     Full-text available via subscription   (4 followers)
Australian Holstein Journal     Full-text available via subscription  
Australian Journal of Agricultural and Resource Economics     Hybrid Journal   (5 followers)
Australian Journal of Agricultural Engineering     Open Access  
Australian Sugarcane     Full-text available via subscription  
Avances en Investigacion Agropecuaria     Open Access  
Bangladesh Journal of Agricultural Research     Open Access   (1 follower)
Bangladesh Journal of Scientific Research     Open Access  
Berkala Ilmiah Pertanian     Open Access   (1 follower)
Bioagro     Open Access   (1 follower)
Biocatalysis and Agricultural Biotechnology     Hybrid Journal   (5 followers)
Biocontrol Science and Technology     Hybrid Journal   (5 followers)
Biodiversity     Hybrid Journal   (16 followers)
Biodiversity : Research and Conservation     Open Access   (17 followers)
Biological Agriculture & Horticulture : An International Journal for Sustainable Production Systems     Partially Free   (12 followers)
Biosystems Engineering     Hybrid Journal   (1 follower)
Biotemas     Open Access  
Bragantia     Open Access   (2 followers)
Brazilian Archives of Biology and Technology     Open Access   (1 follower)
British Poultry Science     Hybrid Journal   (5 followers)
California Agriculture     Open Access   (1 follower)

        1 2 3 4 5 | Last

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  [2556 journals]   [SJR: 0.757]   [H-I: 58]
  • Automatic fruit recognition and counting from multiple images
    • Abstract: Publication date: February 2014
      Source:Biosystems Engineering, Volume 118
      Author(s): Y. Song , C.A. Glasbey , G.W. Horgan , G. Polder , J.A. Dieleman , G.W.A.M. van der Heijden
      In our post-genomic world, where we are deluged with genetic information, the bottleneck to scientific progress is often phenotyping, i.e. measuring the observable characteristics of living organisms, such as counting the number of fruits on a plant. Image analysis is one route to automation. In this paper we present a method for recognising and counting fruits from images in cluttered greenhouses. The plants are 3-m high peppers with fruits of complex shapes and varying colours similar to the plant canopy. Our calibration and validation datasets each consist of over 28,000 colour images of over 1000 experimental plants. We describe a new two-step method to locate and count pepper fruits: the first step is to find fruits in a single image using a bag-of-words model, and the second is to aggregate estimates from multiple images using a novel statistical approach to cluster repeated, incomplete observations. We demonstrate that image analysis can potentially yield a good correlation with manual measurement (94.6%) and our proposed method achieves a correlation of 74.2% without any linear adjustment for a large dataset.


      PubDate: 2014-01-24T00:04:55Z
       
  • Characterising droplets and precipitation profiles of a fixed spray-plate
           sprinkler
    • Abstract: Publication date: March 2014
      Source:Biosystems Engineering, Volume 119
      Author(s): Habib Sayyadi , Amir Hossein Nazemi , Ali A. Sadraddini , Reza Delirhasannia
      Droplet characteristics and precipitation profiles of a fixed spray plate sprinkler (FSPS) were characterised in some indoor experiments were conducted using various deflection plates (36-grooved blue, 30-grooved green and 36-grooved black plates). Four nozzle diameters (2.78, 3.97, 4.76 and 7.14 mm) were mounted on the sprinkler and operated at three pressures (69, 138 and 241 kPa) and at a nozzle height of 1.5 m. Drop characteristics were determined using a low speed digital photography method. The results showed that by increasing the nozzle size at a fixed operating pressure the resulted wetted diameter, peak application rate, droplet sizes and velocities were increased. With smaller nozzle diameters (2.78 and 3.97 mm) drop diameter increased as working pressure increased, while with larger diameters (4.76 and 7.14 mm) a reverse trend between drop size and working pressure was observed. Empirical equations were developed to estimate the wetted diameter and also volumetric mean diameter (VMD) and volume median diameters (D 50) of droplets at different distances from the sprinkler as functions of sprinkler configurations.


      PubDate: 2014-01-24T00:04:55Z
       
  • Analysis of the detachment of citrus fruits by vibration using artificial
           vision
    • Abstract: Publication date: March 2014
      Source:Biosystems Engineering, Volume 119
      Author(s): A. Torregrosa , F. Albert , N. Aleixos , C. Ortiz , J. Blasco
      The vibratory behaviour of citrus fruits is studied using slow-motion cameras in order to gain a better understanding of the parameters involved in fruit detachment when mechanical harvesting is done using shakers. Single citrus fruits with a small portion of stem were vibrated using strokes from 60 mm to 180 mm and frequencies from 3 Hz to 18 Hz. The movement was recorded at 300 fps and the main parameters considered for fruit detachment were determined through the analysis of the video sequences. Image-processing algorithms created for this purpose were applied to the automated estimation of the centroid of the fruit, the angle of the stem–pistil axis, and the position of some selected points in the fruit in each frame of the video sequences to obtain dynamic parameters such as the position, speed and acceleration of the fruit during the movement until it is detached. The signals obtained from the image processing were filtered, providing results in accordance with the calibration systems. In general, results suggest that the inertial forces transmitted to the fruit were lower than the tensile forces required to detach the fruit by pulling it in the stem–pistil direction. The largest peaks were observed using long strokes that required fewer cycles for detachment. On the other hand, short strokes combined with high frequencies needed more cycles, and thus a fatigue phenomenon was present. Short strokes and low frequencies were unable to detach some fruit.


      PubDate: 2014-01-24T00:04:55Z
       
  • Corrigendum to “Wheel Traffic Effects on Tillage Draught” [J
           Agric Eng Res 75 (2000) 375–382]
    • Abstract: Publication date: Available online 15 January 2014
      Source:Biosystems Engineering
      Author(s): Jeffrey N. Tullberg



      PubDate: 2014-01-16T00:05:36Z
       
  • Traditional olive tree response to oil olive harvesting technologies
    • Abstract: Publication date: February 2014
      Source:Biosystems Engineering, Volume 118
      Author(s): Rafael R. Sola-Guirado , Sergio Castro-García , Gregorio L. Blanco-Roldán , Francisco Jiménez-Jiménez , Francisco J. Castillo-Ruiz , Jesús A. Gil-Ribes
      Traditional olive tree growing is a symbol of the Mediterranean basin agriculture. Technological development of this mostly rainfed crop has been reduced and related with employment in rural areas. In order to improve the harvesting process of this crop, this study analyses the available technologies used for fruit detachment and the introduction of a continuous harvesting system, based on a tractor-drawn canopy shaker, to work around the large canopy trees. Results showed that harvest efficiency of mass mechanical systems, such as a trunk shaker (90.5%) and canopy shaker (78.8%), was lower than that of manual harvesting and hand-held harvesting systems (98%). However, these last systems led to high debris production because they mainly extend the harvest time to increase harvest efficiency. Canopy shaker system applied the forced vibration directly to the fruit-bearing branches. This characteristic recognised that vibration transmission plays a less important role on the fruit detachment process. The continuous harvesting process around the large canopy trees in traditional olive orchards enabled relatively high harvest efficiency values to be achieved, considering the trees were not adapted to mechanical harvesting. High harvesting efficiency values were obtained mainly where the rods were in contact with the canopy. An adaptation of the tree through pruning is required to avoid large irregularities in the tree canopy, reduce fruiting inside the canopy that is unreachable by the canopy shaker rods and facilitate the penetration of the rods into the canopy in order to achieve higher harvest efficiency values.


      PubDate: 2014-01-16T00:05:36Z
       
  • Bulk compression characteristics of straw and hay
    • Abstract: Publication date: February 2014
      Source:Biosystems Engineering, Volume 118
      Author(s): Kenny D. Nona , Bart Lenaerts , Erdal Kayacan , Wouter Saeys
      Compression of biological materials facilitates their transport and storage. In agriculture, straw and hay are commonly compressed with extrusion, but this process is highly influenced by changing crop conditions. A mathematical description of the compression profile of fibrous materials would be useful to compare the compression characteristics of different materials and to predict the energy required for compressing it to a certain density. In this study, different biomass modelling techniques have been reviewed to select the most useful crop compression model. It is shown that the selected crop model (Faborode model) is appropriate in describing the crop compression up to a density of 145 kg m−3, dry matter (with R 2 > 0.8). The selected stress-deformation relation (Faborode model) involves two crop parameters which are determined for wheat straw and hay at different moisture contents and particle orientations (random and parallel stacking). These parameters allow for separating the time-dependent and the elastic compression behaviour. The relaxation properties of the samples have been estimated by fitting the stress decay over time. It is shown that a Maxwell model cannot properly describe the relaxation (R 2 > 0.7) while the Peleg model resulted in reasonable fits with high R 2 (>0.8). Although the model of Peleg is accurate only after a relaxation time of 1 s, the parameters can be used in describing the relaxation behaviour.


      PubDate: 2014-01-16T00:05:36Z
       
  • Vision-based localisation of mature apples in tree images using convexity
    • Abstract: Publication date: February 2014
      Source:Biosystems Engineering, Volume 118
      Author(s): Eliyahu (Efim) Kelman , Raphael Linker
      This paper details a procedure for detecting apples in tree images using shape analysis are presented. The core of the procedure consists of a so-termed convexity test that identifies edges that could correspond to three-dimensional convex objects of a given size range from a much larger set of edges. This is achieved by analysing a number of intensity profiles that originate at each edge and determining whether they have a shape that is suitable with a 3D convex object of the correct size. We show that contrarily to the prevailing opinion, the intensity functions of three-dimensional convex objects are not necessarily convex, which led us to developing models for describing such profiles. The simplest suitable model includes four parameters that can be easily estimated by a standard least square constrained optimization procedure. After merging the selected edges that fall on circles, a second analysis is performed to remove false positive detections and eliminate multiple detections of apples. The procedure was demonstrated on 51 grey-level images that were recorded in a Golden Delicious apple variety orchard under natural light conditions. On average, together with preliminary pre-processing operations, the convexity test removed 99.8% of the edges initially identified by Canny filter. Analysis based on the remaining edges led to correct detection of 94% of the apples visible in the images. Fourteen percent of the identified objects were “false positive” detections, mainly due to leaves or parts of leaves that generated convex surfaces very similar to apples, or by leaves that lay on apples and created misleading edges.


      PubDate: 2014-01-12T00:04:51Z
       
  • Effects of mineral contamination on the ash content of olive tree residual
           biomass
    • Abstract: Publication date: February 2014
      Source:Biosystems Engineering, Volume 118
      Author(s): A. García-Maraver , L.C. Terron , A. Ramos-Ridao , M. Zamorano
      The rise in energy consumption has made the use of alternative fuels a priority. Residual biomass is an abundant renewable energy resource whose use can lead to significant socioeconomic and environmental benefits. This biomass is destined to play an important role in the new energy model since agricultural residues are produced in huge amounts throughout the world. Consequently, converting this residue into an energy product increases the value of these waste materials and reduces the environmental impact of waste disposal. The generation of agricultural residues from the olive sector in the Mediterranean area is an important source of residual biomass highly suitable for thermal energy generation. This biomass comes from olive groves and olive oil production plants that generate by-products with high energy content. However, since the properties of biomass are dependent on a wide range of factors, the focus of our research was to analyse all of its forms (leaves, branches, bark and wood) separately in order to better understand their thermal behaviour and assure the quality of the final energy product. The determination of the ash content for each type of olive tree residual biomass indicated that olive leaves were responsible for the high ash content of this biomass. As a result, various cleaning methods were used to study the effect of the mineral contamination from leaves on the final ash content. The ashes were also analysed with a microscope to ascertain their composition.


      PubDate: 2014-01-08T00:04:57Z
       
  • Embodied energy of sugarcane harvesters
    • Abstract: Publication date: February 2014
      Source:Biosystems Engineering, Volume 118
      Author(s): Edemilson J. Mantoam , Marcos Milan , Leandro M. Gimenez , Thiago L. Romanelli
      Intensification of agricultural production has largely been based on higher energy demand. In Brazil, sugarcane cultivation, ethanol production and the adoption of mechanised harvesting have increased since 2000 due to economic decisions and environmental constraints. Evaluating the energy demand in production systems is a way to measure how intensification is converted into yield, mainly in energy crops such as sugarcane. The energy embodiment in agricultural machinery has been studied, but generally based on data from automotive production. This study aimed to determine the energy demanded in the life cycle of a sugarcane harvester. It is aimed at providing suggestions for further studies approaching other machinery and to provide detailed material flows, in order to give support for other environmental evaluations. Two harvesters were evaluated: Harvester 1 (H1), with steel wheels and rubber tyres and Harvester 2 (H2) with metal tracks. The embodied energy of the life cycle of a sugarcane harvester included the repair and maintenance phase, the directly used inputs, the indirect inputs and the depreciated infra-structure, whose shares on the energy demand were, respectively, 72.0%, 27.4%, 0.6% and 0.0% for H1 and 72.8%, 26.7%, 0.5% and 0.0 for H2. The indices relating energy demand with life cycle (time), mass and power were 138.8 MJ h−1 202.6 MJ kg−1 and 11.6 GJ kW−1, for H1 and 159.8 MJ h−1, 204.3 MJ kg−1 and 13.3 GJ kW−1, for H2.


      PubDate: 2014-01-08T00:04:57Z
       
  • Relationships between rut depth and soil mechanical properties in a
           calcareous soil with unstable structure
    • Abstract: Publication date: February 2014
      Source:Biosystems Engineering, Volume 118
      Author(s): A. Hemmat , M. Yaghoubi-Taskoh , A. Masoumi , M.R. Mosaddeghi
      For proper management of soil-machinery interactions, it is essential to know the mechanical strength (i.e. pre-compaction stress, σ pc) of agricultural soils. However, there is little information linked directly to soil sinkage in the field to σ pc. This research was conducted to explore the relationships of rut depth (d R) with σ pc, penetration resistance (CI) and dynamic drop-cone resistance (DCI) in a calcareous clay loam soil with unstable structure. The σ pc, CI, DCI, and d R were determined before and after single or multiple wheelings with two tractors under different soil conditions. Average ground pressure (σ g) applied by the tractors was also determined. The σ pc was determined using large undisturbed soil samples which were taken from the 0–15 cm layer in the wheel track. The CI, DCI and d R were measured simultaneously along the tyre centreline. When σ pc values before each wheeling were compared with d R values after wheeling, it was found that σ pc was approximately a threshold value between reversible and irreversible deformations. The results indicated that when the σ pc/σ g is well above 1 (e.g. 1.6), soil sinkage is essentially negligible. However, for the ratios <1.6, soil sinkage is irreversible and significant. These findings and published documents show that some physico-empirical safety factor greater than 1 is needed as a criterion for field traffic in structurally-unstable soils. Similarly, two-region trends were also observed between d R and CI or DCI. As soil trafficability criteria, soil properties such as CI and DCI, which are easily and quickly measurable, might be used for practical purposes.


      PubDate: 2014-01-04T00:05:08Z
       
  • Determination of impact energy to devitalise annual ryegrass (Lolium
           rigidum) seed from one impact using double and single sided impacts
    • Abstract: Publication date: February 2014
      Source:Biosystems Engineering, Volume 118
      Author(s): Nicholas K. Berry , John M. Fielke , Chris Saunders
      Herbicide resistance is one of the most significant challenges for cropping systems that rely on herbicides for weed control. To address this challenge, mechanical weed control methods are being investigated that apply impact energy to weed seeds in the chaff after they exit the sieve of a combine harvester. A pendulum impact tester applying a double-sided impact and a rotational impact tester applying a single-sided impact were used to apply a single impact to annual ryegrass (Lolium rigidum) seeds. The impacted seeds were evaluated for physical damage and germination potential under controlled conditions using paper and soil. A logistic regression was used to model energy dose response for visibly damaged seeds and seed devitalisation based on: normal germinated seeds on paper; total germinated seeds on paper (normal + abnormal) and emerged seedlings in soil bins. The median effective dose (ED50) of impact energy for visibly damaging seeds was lower for the double-sided impact of the pendulum impact tester (6.5 mJ) compared to the single-sided impact of the rotational impact tester (8.7 mJ). However, the rotational impact tester was more efficient at devitalising seeds having a median effective dose of 7.1 mJ and 3.0 mJ for devitalisation based on both normal germination and total germination, respectively; compared to 15.7 mJ and 6.8 mJ, respectively for the pendulum impact tester. These energy values required to devitalise seeds is data that can be used in the design of machinery for mechanical weed seed control.


      PubDate: 2014-01-04T00:05:08Z
       
  • A novel method to measure the impact of sea transport motion on sheep
           welfare
    • Abstract: Publication date: February 2014
      Source:Biosystems Engineering, Volume 118
      Author(s): Eduardo Santurtun , Valerie Moreau , Clive J.C. Phillips
      Sheep are subjected to multiple stressors during commercial sea transport, including ship motion, ammonia, novel social dynamics and feed, high stocking density and multiple handling, all of which make it difficult to measure sheep responses to ship motion in isolation during a voyage. A practical method for measuring the impact of ship motions on the welfare of sheep on land was therefore developed, which exposed them to the three most important motions, roll (sideways), heave (vertical) and pitch (fore-aft). Roll and pitch motions were created using a programmable flight simulator platform, and heave motion was simulated elevating the entire apparatus with an electric forklift. Two main methods were developed to investigate the effect of these motions on sheep behaviour, physiology, balance, body posture, heart rate variability, rumination and feed intake. The first method evaluated each of the motions independently, replicating the frequency and magnitude of typical ship movements, taking into consideration the dimensions of a commercial vessel. The second method compared regular and irregular (random) movement sequences to investigate the importance of movement predictability on stress responses from sheep. The behaviour of sheep on the platform was similar to that which has been observed on ship. It is concluded that a detailed understanding of the responses of sheep to ship motion can be obtained by subjecting them to the different components of simulated transport using land-based equipment.


      PubDate: 2014-01-04T00:05:08Z
       
  • Prediction of the spread of highly pathogenic avian influenza using a
           multifactor network: Part 2 – Comprehensive network
           analysis with direct/indirect infection route
    • Abstract: Publication date: February 2014
      Source:Biosystems Engineering, Volume 118
      Author(s): Hyung-jin Lee , Kyo Suh , Nam-su Jung , In-bok Lee , Il-hwan Seo , Oun-kyung Moon , Jeong-jae Lee
      Epidemic diseases of domestic animals, such as high pathogenic avian influenza, can be directly spread by poultry-related business personnel/vehicles visiting farms and can be indirectly caused by aerial spread. However, most of comprehensive analysis studies have considered only direct or indirect causes. The purpose of this study is to construct a direct HPAI spread network based on the relationships between farms using poultry-related business data from 39 farms in the Kimje district of South Korea and an indirect HPAI spread network using the aerial spread from each farm during the HPAI outbreak in 2008. Direct/indirect HPAI spread networks were also analysed using centrality analyses to identify highly vulnerable farms for infection and highly influential farms on other farms so the initial spread can be prevented. This study proposes an optimal prevention solution through a comprehensive spread simulation and compares the centrality of infected/suspected farms by tracing the infection routes for network validation.


      PubDate: 2013-12-27T09:02:19Z
       
  • Comparison of equilibrium and logarithmic models for grain drying
    • Abstract: Publication date: February 2014
      Source:Biosystems Engineering, Volume 118
      Author(s): Daniela de C. Lopes , Antonio José Steidle Neto , Jéssika K. Santiago
      Mathematical simulation is an important tool for optimising agricultural processes to reduce costs. Many models have been proposed and adapted to simulate grain drying. Among them, are the logarithmic or Hukill model and the equilibrium or Thorpe model, which do not require expensive solution techniques and can be used to evaluate the grain-drying behaviour regarding process time, grain temperature and variations in grain moisture content. These models were compared with experimental data found in the literature. The two models were also compared regarding predicted grain temperatures, grain moisture contents and drying times. Results showed that both models gave good prediction performance, but the Thorpe model was slightly better than the Hukill. The Thorpe model is applicable over a wider range of drying situations, including processes with variable inlet air conditions. It also provides a more fundamental understanding of the drying process. However, the logarithmic model has advantages with respect to simplicity and speed of solution.


      PubDate: 2013-12-27T09:02:19Z
       
  • Internal characterisation of fresh agricultural products using traditional
           and ultrafast electron beam X-ray computed tomography imaging
    • Abstract: Publication date: January 2014
      Source:Biosystems Engineering, Volume 117
      Author(s): Irwin R. Donis-González , Daniel E. Guyer , Anthony Pease , Frank Barthel
      Currently, destructive techniques can be employed to evaluate the internal attributes of fresh fruits, vegetables and nuts. However, clearly not all produce can be evaluated. Thus, there is a need to develop an in vivo non-destructive technique able to assess fresh agricultural commodity internal components, especially disorders. In this study, medical grade computed tomography (CT) was used to obtain transversal two-dimensional (2D) images from several fresh agricultural product phenomena. CT scanning was performed by placing and securing numbered samples onto a whole polyethylene sheet, placed on the CT scanner table. Phenomena included the internal decay of chestnuts (Castanea spp.), internal defects in pickling cucumbers (Cucumis sativus), translucency disorder in pineapples (Ananas comosus), pit presence in tart cherries (Prunus cerasus var. Montmorency) and plum curculio (Conotrachelus nenuphar) infestation of tart cherries. In addition, an ultrafast X-ray CT scanner was also used to visualise internal characteristics of fresh chestnuts. Chestnuts were labelled and packed in a thin plastic hose, which was pulled through the scanning plane. The 2D CT X-ray images and post-processing three-dimensional CT image reconstruction indicate that CT can be used as an accurate in vivo insight of fresh intact agricultural products. Results suggest that there is a potential for non-destructive inline sorting of the internal quality of several agricultural products. The long-term objective is that the fresh and processing product industries will then be able to detect internal quality attributes of fresh agricultural commodities, at a relatively early stage, after validation under commercial conditions.


      PubDate: 2013-12-23T00:04:56Z
       
  • Automatic corn (Zea mays) kernel inspection system using novelty detection
           based on principal component analysis
    • Abstract: Publication date: January 2014
      Source:Biosystems Engineering, Volume 117
      Author(s): José M. Valiente-González , Gabriela Andreu-García , Paulus Potter , Ángel Rodas-Jordá
      Corn (Zea mays) kernel processing companies evaluate the quality of kernels to determine the price of a batch. Human inspectors in labs inspect a reduced set of kernels to estimate the proportion of damaged kernels in any given lot. The visual differences between good and damaged kernels may be minor and, therefore, difficult to discern. Our goal is to design a computer vision system that enables the automatic evaluation of the quality of corn lots. To decide if an individual kernel can be accepted or rejected, it is necessary to design a method to detect defects, as well as quantify the defective proportions. A setup to work in-line and an approach to identify damaged kernels that combines algorithm-based computer vision techniques of novelty detection and principal component analysis (PCA) is presented. Experiments were carried out in three colour spaces using 450 dent corn kernels previously classified by experts. Results show that the method is promising (92% success) but extensions are recommended to further improve results.


      PubDate: 2013-12-23T00:04:56Z
       
  • Hyperspectral imaging of intact bell peppers
    • Abstract: Publication date: January 2014
      Source:Biosystems Engineering, Volume 117
      Author(s): Ze'ev Schmilovitch , Timea Ignat , Victor Alchanatis , Janna Gatker , Viacheslav Ostrovsky , József Felföldi
      Agricultural engineering technologies have successfully addressed certain challenges by the use of advanced sensors and machine vision technologies. The objective of this study was to develop a non-destructive method to evaluate and to map quality indices in bell pepper. Three cultivars of bell pepper (‘Ever Green’, ‘No. 117’ and ‘Celica’) were studied during maturation by using hyperspectral imaging in the visible and near-infrared (550–850 nm) region. Peppers were marked in the flowering stage and 20 samples from each variety were collected weekly, along a growing period of seven weeks, until full growth. Quality parameters like total soluble solids, total chlorophyll, carotenoid and ascorbic acid content were determined and correlated with the spectral data. Images of intact peppers were collected by an acousto-optic-tuneable-filter (AOTF) hyperspectral charged-coupled-device (CCD) camera, in spectral resolution of 5 nm. Spectral information of the hyper cubes was analysed by chemometric procedures. Partial least squares regression was used for model development. Comparisons were made between the PLS regression analysis of the reflectance spectra (R), and the pre-processed spectra such as the first derivative (D 1 R), log(1/R), D 1(log(1/R)) and D 2(log(1/R)). Models were established to predict the quality attributes creating the basis for multiple sampling of a particular fruit or individual peppers from many fruits in the same time. High correlations were obtained by the established models with coefficients of determination of 0.95, 0.95, 0.97, and 0.72 for total soluble solids, total chlorophyll, carotenoid and ascorbic acid content, respectively.


      PubDate: 2013-12-23T00:04:56Z
       
  • Estimation of orange skin thickness based on visual texture coarseness
    • Abstract: Publication date: January 2014
      Source:Biosystems Engineering, Volume 117
      Author(s): Abdolabbas Jafari , Atefeh Fazayeli , Mohammad Reza Zarezadeh
      Much research has been carried out on grading citrus fruits using machine vision. Citrus grading is normally achieved based on external visible criteria including size, shape, and colour of the fruits. However, identification of the internal characteristics of the fruits is almost impossible by computer vision which uses visible spectral imaging. Thickness of the fruit skin is one of the important factors for consumers which can be considered as a grading criterion. Citrus fruits with thin skins are more desirable but it calls for spectral solutions. However, internal quality of the fruits can be evaluated if there is a correlation between the internal and visible external characteristics. It is normally seen that oranges with coarser surfaces have thicker skin and vice versa. Such correlation between the surface coarseness and thickness of the skin was investigated in this research. Coarseness of the skin could be verified by normal visible imaging. An innovative approach is described for fast description of texture while retaining the accuracy of high resolution images. Three strips having a width of one pixel were selected from the images. A coarseness factor was devised that utilized successive moving average filters. A correlation was achieved between the coarseness factors and thickness of the oranges which showed a good agreement between these two factors (R 2 = 0.944). The experiments demonstrated that this method could be used for non-destructive grading of orange or other citrus fruits to evaluate skin ratio of the fruit by using a simple and inexpensive machine vision system.


      PubDate: 2013-12-23T00:04:56Z
       
  • A new method for pedicel/peduncle detection and size assessment of
           grapevine berries and other fruits by image analysis
    • Abstract: Publication date: January 2014
      Source:Biosystems Engineering, Volume 117
      Author(s): Sergio Cubero , María Paz Diago , José Blasco , Javier Tardáguila , Borja Millán , Nuria Aleixos
      The berry size of wine-grapes has often been considered to influence wine composition and quality, as it is related to the skin-to-pulp ratio of the berry and the concentration of skin-located compounds that play a key role in the wine quality. The size and weight of wine-grapes are usually measured by hand, making it a slow, tedious and inaccurate process. This paper focuses on two main objectives aimed at automating this process using image analysis: (1) to develop a fast and accurate method for detecting and removing the pedicel in images of berries, and (2) to accurately determine the size and weight of the berry. A method to detect the peduncle of fruits is presented based on a novel signature of the contour. This method has been developed specifically for grapevine berries, and was later extended and tested with an independent set of other fruits with different shapes and sizes such as peppers, pears, apples or mandarins. Using this approach, the system has been capable of correctly estimating the berry weight (R 2 > 0.96) and size (R 2 > 0.97) of wine-grapes and of assessing the size of other fruits like mandarins, apples, pears and red peppers (R 2 > 0.93). The proven performance of the image analysis methodology developed may be easily implemented in automated inspection systems to accurately estimate the weight of a wide range of fruits including wine-grapes. In this case, the implementation of this system on sorting tables after de-stemming may provide the winemaker with very useful information about the potential quality of the wine.


      PubDate: 2013-12-23T00:04:56Z
       
  • Identification and determination of the number of immature green citrus
           fruit in a canopy under different ambient light conditions
    • Abstract: Publication date: January 2014
      Source:Biosystems Engineering, Volume 117
      Author(s): Subhajit Sengupta , Won Suk Lee
      Yield mapping for tree crops by mechanical harvesting requires automatic detection and counting of fruits in tree canopy. However, partial occlusion, shape irregularity, varying illumination, multiple sizes and similarity with the background make fruit identification a very difficult task to achieve. Therefore, immature green citrus-fruit detection within a green canopy is a challenging task due to all the above-mentioned problems. A novel algorithmic technique was used to detect immature green citrus fruit in tree canopy under natural outdoor conditions. Shape analysis and texture classification were two integral parts of the algorithm. Shape analysis was conducted to detect as many fruits as possible. Texture classification by a support vector machine (SVM), Canny edge detection combined with a graph-based connected component algorithm and Hough line detection, were used to remove false positives. Next, keypoints were detected using a scale invariant feature transform (SIFT) algorithm and to further remove false positives. A majority voting scheme was implemented to make the algorithm more robust. The algorithm was able to accurately detect and count 80.4% of citrus fruit in a validation set of images acquired from a citrus grove under natural outdoor conditions. The algorithm could be further improved to provide growers early yield estimation so that growers can manage grove more efficiently on a site-specific basis to increase yield and profit.


      PubDate: 2013-12-23T00:04:56Z
       
  • An automated growth measurement system for leafy vegetables
    • Abstract: Publication date: January 2014
      Source:Biosystems Engineering, Volume 117
      Author(s): Yu-Hui Flora Yeh , Tsung-Cheng Lai , Ting-Yu Liu , Chang-Chih Liu , Wei-Chang Chung , Ta-Te Lin
      In plant science, the fundamental information for research and related applications is derived from the measurement of plant features. It is especially useful for applications in plant growth modelling and climate control in greenhouses or plant factories. Standard, direct measurement methods are generally simple and reliable, but they are time consuming and laborious. In contrast, vision-based methods are non-destructive and an efficient way to describe external plant features and plant growth. In this study, a stereo-vision system, using two off-the-shelf cameras with parallel optical axes, integrated a self-developed image processing algorithm to monitor the growth of Boston lettuce in a plant factory. The system was mounted on a sliding rail to extend the field of vision of planting beds. Images were continuously recorded to determine the plants' features and construct panoramic images. The image processing algorithms, that calculated geometric features such as the projected leaf area, plant height, volume and diameters were developed and incorporated into the automated measurement system. Subsequently, plant growth curves were determined from calculations of the plant features data. This automated vision-based system showed promising results when put into practice.


      PubDate: 2013-12-23T00:04:56Z
       
  • Automatic detection of tulip breaking virus (TBV) in tulip fields
           using machine vision
    • Abstract: Publication date: January 2014
      Source:Biosystems Engineering, Volume 117
      Author(s): Gerrit Polder , Gerie W.A.M. van der Heijden , Joop van Doorn , Ton A.H.M.C. Baltissen
      Tulip breaking virus (TBV) causes severe economic losses in flower bulbs in the Netherlands. To prevent further spread by aphids, the vector of the disease, infected plants must be removed from the field as soon as possible. Until now screening has been carried out by visual inspection in the field. As the availability of human experts is limited there is an urgent need for a rapid, automated and objective method of screening. Based on laboratory experiments, a vision method for use in open fields has been developed. In the period 2009–2012 field trials were carried out and the techniques were tested and improved. During the final evaluation of our system, in the last experiment (2012), the system approached the scores obtained by the experienced crop experts.
      Graphical abstract image

      PubDate: 2013-12-23T00:04:56Z
       
  • A digital image-processing-based method for determining the crop
           coefficient of lettuce crops in the southeast of Spain
    • Abstract: Publication date: January 2014
      Source:Biosystems Engineering, Volume 117
      Author(s): Daniel G. Fernández-Pacheco , David Escarabajal-Henarejos , Antonio Ruiz-Canales , Julián Conesa , Jose M. Molina-Martínez
      In the arid and semi-arid regions of the southeast of Spain, the low availability of water for irrigation requires the development of new water-conserving irrigation techniques. This leads to the use of precision agriculture technologies that permit an improvement in performance or reductions in the consumption of water and fertilisers. In this context, the use of digital photography enables plant growth monitoring, which allows crop water requirements to be determined from variables that are directly related to evapotranspiration. One of these variables is the percentage of ground cover, which has also been correlated with plant height. This paper presents a new method based on computer vision for estimating the crop coefficient (K c) of lettuce crops from the percentage of ground cover (PGC) extracted from digital photographs. In contrast to other methods reported in the literature, plant height (h) is estimated first; then, the term PGC/h is correlated with K c. The method was successfully applied to and validated using a commercial crop of lettuce (Lactuca sativa L. cv. ‘Hierro’) located in the southeast of Spain.


      PubDate: 2013-12-23T00:04:56Z
       
  • Water stress detection based on optical multisensor fusion with a least
           squares support vector machine classifier
    • Abstract: Publication date: January 2014
      Source:Biosystems Engineering, Volume 117
      Author(s): Dimitrios Moshou , Xanthoula-Eirini Pantazi , Dimitrios Kateris , Ioannis Gravalos
      The objective was to optically discriminate between healthy and water stressed wheat canopies. Canopies were grown under greenhouse conditions. The aim was to develop an optical multisensor system that can detect and identify biotic and abiotic stresses. In the current investigation the successful recognition of water stressed and healthy winter wheat plants in the presence of a Septoria tritici infection is presented. The difference in spectral reflectance and fluorescence response between healthy and stressed wheat plants was investigated. Stress type detection algorithms have been developed based on the combination of least squares support vectors machine (LSSVM) with sensor fusion. Through the use of LSSVM, classification performance increased to more than 99%. These results show promise for the development of cost-effective detectors for automated recognition of different biotic and abiotic stresses.


      PubDate: 2013-12-23T00:04:56Z
       
  • Editorial Board
    • Abstract: Publication date: January 2014
      Source:Biosystems Engineering, Volume 117




      PubDate: 2013-12-23T00:04:56Z
       
  • Editorial
    • Abstract: Publication date: January 2014
      Source:Biosystems Engineering, Volume 117
      Author(s): Jose Blasco , Enrique Moltó , Nuria Aleixos , Manuela Zude



      PubDate: 2013-12-23T00:04:56Z
       
  • Getting simultaneous red and near-infrared band data from a single digital
           
    • Abstract: Publication date: January 2014
      Source:Biosystems Engineering, Volume 117
      Author(s): Gilles Rabatel , Nathalie Gorretta , Sylvain Labbé
      Multispectral images, including red and near-infrared bands, have proved efficient for vegetation–soil discrimination and agricultural monitoring in remote-sensing applications. However, they remain little used in ground-based and unmanned aerial vehicle (UAV) imagery, due to a limited availability of adequate 2D imaging devices. A methodology is proposed to obtain simultaneously the near-infrared and red bands from a standard single RGB camera, after having removed the near-infrared blocking filter inside. Its ability to provide satisfactory NDVI (normalised difference vegetation index) computation for vegetation and soil has been assessed through spectral simulations. Application in field conditions with Canon 500 D and Canon 350D cameras has then been considered, taking into account signal–noise and demosaicing concerns. The results obtained have proved the practical usability of this approach, opening new technical possibilities for crop monitoring and agricultural robotics.


      PubDate: 2013-12-23T00:04:56Z
       
  • Development of a prototype malaxer to investigate the influence of oxygen
           on extra-virgin olive oil quality and yield, to define a new design of
           machine
    • Abstract: Publication date: February 2014
      Source:Biosystems Engineering, Volume 118
      Author(s): Alessandro Leone , Roberto Romaniello , Riccardo Zagaria , Antonia Tamborrino
      The malaxation has been a focus of extra-virgin olive oil (EVOO) research for many years. A system that supplied gas and measured oxygen concentration was implemented on a prototype malaxer that was used as a control tool to investigate the influence of oxygen concentration on the final quality and extraction yield of EVOO. The oxygen content in the headspace and olive paste was measured and the balance between these contents was assessed; a high correlation between the oxygen consumed in the headspace and the oxygen consumed by the olive paste was found. The optimal amount of oxygen per kilogram of dough over 40 min of kneading was identified to be in the range 55.4–77.9 mg [O2] kg−1 [olive paste]. This oxygen content facilitates the acquisition of the best qualitative and quantitative performance during the malaxation process. These data allowed us to define new basic parameters for the malaxer design and to optimise the extraction performance, thus ensuring the production of high-quality olive oil.


      PubDate: 2013-12-23T00:04:56Z
       
  • Sorptional behaviour of rosehip leather formulations added with sucrose or
           polydextrose
    • Abstract: Publication date: February 2014
      Source:Biosystems Engineering, Volume 118
      Author(s): Silvana M. Demarchi , Natalia A. Quintero Ruiz , Sergio A. Giner
      The sorptional behaviour of two formulations intended to develop rosehip leathers, both based on rosehip fruit pulp, was assessed experimentally. One formulation had sucrose added, while polydextrose was added to the other to reduce the calorie intake. Isotherms were measured by the static gravimetric method at 10, 20, 40 and 60 °C. The GAB equation and a model proposed by Leiva Díaz, Giannuzzi, and Giner (2009) gave the best representation of data for sucrose- and polydextrose-added formulations, respectively. A detailed statistical analysis revealed an interaction between composition and temperature effects on isotherms. Sucrose proved to be more effective than polydextrose to lowering the water activity of the formulation, except in conditions that favour the formation of sucrose crystals. In general, the water activity of the polidextrose-added formulation, which did not experience crystallisation, increased with increasing temperature for a given moisture content. However, the temperature effect on the isotherms of the sucrose-added matrix was more complex, possibly being affected by crystallisation.


      PubDate: 2013-12-19T00:05:08Z
       
  • Performance of new agricultural impact sprinkler fitted with plastic
           nozzles
    • Abstract: Publication date: February 2014
      Source:Biosystems Engineering, Volume 118
      Author(s): Talel Stambouli , Nery Zapata , José M. Faci
      The radial water distribution and irrigation performance of an agricultural sprinkler with plastic nozzles were analysed. Twenty-six tests with an isolated sprinkler corresponding to different combinations of three working pressure (p, 200, 300 and 400 kPa) and three nozzle diameters of the main nozzle (4.0, 4.5 and 5.0 mm) were performed to evaluate the radial water distribution curves, All the tests were performed under calm wind (≤1 m s−1) under open air conditions. Fifty tests corresponding to six combinations of nozzle diameter and pressure with the same sprinkler model were performed under a wide range of meteorological conditions in a rectangular solid-set system at 18 m × 18 m sprinkler spacing to evaluate the Christiansen's Uniformity Coefficient (CUC) and wind drift and evaporation losses (WDEL). The resulting radial water distribution curves were compared with those from impact sprinklers with brass nozzles. Sprinkler model had an important effect on the radial water distribution, even under similar operational conditions, and these differences were shown in the first 2.5–6 m from the sprinkler. The CUC and WDEL of a solid-set sprinkler system were compared with simulated values from the “Ador-Sprinkler” model. The results of this analysis showed that the type of sprinkler had a moderate influence on sprinkler irrigation uniformity. The analysis presented in this study may serve to develop a decision tool to choose the most suitable combinations of sprinkler model, nozzle diameter and working pressure to optimise the uniformity and efficiency of sprinkler irrigation.


      PubDate: 2013-12-11T03:04:16Z
       
  • Investigation into the mechanisms of pipeline transport of slurries of
           wheat straw and corn stover to supply a bio-refinery
    • Abstract: Publication date: February 2014
      Source:Biosystems Engineering, Volume 118
      Author(s): Mahdi Vaezi , Anil K. Katta , Amit Kumar
      Pipeline hydro-transport could be more economic approach than truck delivery for agricultural waste biomass to a bio-refinery for bio-fuel production. The transportation of slurries of wheat straw and corn stover agricultural waste biomass was investigated through a laboratory-scale closed-circuit pipeline facility. While the slurry was pumped, longitudinal friction loss was measured and analysed as a function of particle type and properties, slurry solid concentration, slurry flow rate, and measured carrier fluid viscosity. Irregularly shaped fibrous particles of agricultural waste biomass 2.0–9.0 mm in length and with aspect ratios of 2–7 exhibited drag-reducing features, e.g. a drag reduction of 33% for a slurry containing 40% [mass] of <3.2 mm corn stover particles. The role of particle dimensions and morphological features on slurry friction loss and drag-reducing behaviour was investigated. The influence of particle size distribution was recognised with broad size distributions producing lower frictional losses at higher flow rates. Above certain flow rates, larger-sized particles at lower solid concentrations produced the same drag ratio as smaller size particles at higher solid concentrations thus requiring lower pumping power. Slurries of wheat straw and corn stover particles affected pressure drop behaviour differently from conventional solid–liquid systems and showed decreasing pressure gradients with increasing solid concentration. The results obtained should assist the design and operation of agricultural waste biomass pipeline hydro-transport processes.


      PubDate: 2013-12-11T03:04:16Z
       
  • Detection of dead entomopathogenic nematodes in microscope images using
           computer vision
    • Abstract: Publication date: February 2014
      Source:Biosystems Engineering, Volume 118
      Author(s): Ferhat Kurtulmuş , Tufan C. Ulu
      Entomopathogenic nematodes are soil-dwelling living organisms which have been widely used for controlling agricultural insect pests as part of biological control. Because easy to use procedures have been developed for their application using standard sprayers, they are one of the best alternatives to pesticides. In laboratory procedures, counting is the most common, laborious, time-consuming and approximate part of the studies conducted on entomopathogenic nematodes. Here, a novel method was proposed to detect and count dead Heterorhabditis bacteriophora nematodes from microscope images using computer vision. The proposed method consisted of three main algorithm steps: pre-processing to obtain the medial axes of the nematode worms as accurately as possible, separation of overlapped nematode worms with a skeleton analysis; and detection of dead nematodes using two different straighter line detection methods. The proposed method was tested on 68 microscope images which included 935 live worms and 780 dead worms. Proposed method was able to detect the worms in microscope images successfully with recognition rates of over 85%.


      PubDate: 2013-12-11T03:04:16Z
       
  • Measurement and prediction of soil erosion in dry field using portable
           wind erosion tunnel
    • Abstract: Publication date: February 2014
      Source:Biosystems Engineering, Volume 118
      Author(s): Se-Woon Hong , In-Bok Lee , Il-Hwan Seo , Kyeong-Seok Kwon , Tae-Wan Kim , Young-Hwan Son , Minyoung Kim
      The purpose of this study was to develop a wind erosion prediction model by in situ measurement using portable wind erosion tunnel. The model has a modified form of the wind erosion equation (WEQ) to represent short-term wind erosion with fast and simple measurable factors. To collect the data under controlled wind conditions but on in situ soils, a portable wind erosion tunnel was designed and utilised during field experiments. Notwithstanding measurements might include any possible error, the multiple linear regression analysis of repetitive experimental data derived the wind erosion prediction model, which showed a good agreement with the measured data with R 2 = 0.61. The short-term wind erosion predicted by the model was made available to CFD simulation by coupling the erosion mechanism with sophisticated wind environment analysis over complex terrain. The land cover data was linked to the CFD simulation by mapping the virtual porosity and using user-defined functions. The CFD simulation coupled with the regression model produced useful results concerning spatial distributions of soil erodibility, erodible area and soil erosion over complex terrain showing good potential of coupling the experimental model with CFD simulation technique. It is also a promising method for evaluation of various wind erosion prevention measures as well as for effective planning and decision-making for wind erosion control.


      PubDate: 2013-12-11T03:04:16Z
       
  • Characteristics of volatile fatty acids in stored dairy manure before and
           after anaerobic digestion
    • Abstract: Publication date: February 2014
      Source:Biosystems Engineering, Volume 118
      Author(s): Laura H. Page , Ji-Qin Ni , Albert J. Heber , Nathan S. Mosier , Xingya Liu , Hung-Soo Joo , Pius M. Ndegwa , Joseph H. Harrison
      Volatile fatty acids (VFA) are among the most abundant volatile organic compounds in dairy manure and are associated with odour nuisance. This paper presents research results of VFA production during a three-month storage of dairy manure from four different sources: a dairy barn (raw), the inlet of an anaerobic digester (influent), the digester outlet (effluent), and the effluent after solid separation (effluent SS). Manure from each source was studied in two lab-scale reactors that were continuously ventilated with fresh air in the manure headspace to simulate manure storage conditions. Two manure samples were taken weekly in the top and bottom manure layers from each reactor for VFA analysis. Five VFA (formic acid, acetic acid, propionic acid, butyric acid, and 2-methylbutyric acid) were identified in all reactors using high performance liquid chromatography (HPLC). The dominant VFA was formic acid for the influent and acetic acid for the other three manure sources. The overall average concentrations of the five VFA were 1963 ± 685 (mean ± standard deviation), 14,175 ± 4825, 286 ± 98, and 169 ± 80 mg l−1 for the raw, influent, effluent, and effluent SS, respectively. The “pre-consumer” organic wastes mixed with dairy manure in the influent significantly increased the total VFA concentrations and the proportion of individual VFA. Concentrations of VFA demonstrated highly temporal and spatial variations. Anaerobic digestion significantly reduced formation of VFA in the effluent and effluent SS. However, the complexity of VFA characteristics made it difficult to reliably model and predict the concentrations and compositions of VFA in dairy manure.


      PubDate: 2013-12-07T00:05:04Z
       
  • Furrow parameters in rotary strip-tillage: Effect of blade geometry and
           rotary speed
    • Abstract: Publication date: February 2014
      Source:Biosystems Engineering, Volume 118
      Author(s): Md. A. Matin , John M. Fielke , Jacky M.A. Desbiolles
      Two-wheeled tractors fitted with rotary cultivators are used in many developing countries for full disturbance soil tillage. Recent development, motivated by the benefits of conservation agriculture, is working toward strip-tillage seeding using two-wheeled tractors fitted with modified rotary cultivators and seeding attachments. The effect of three blade geometries (conventional, half-width and straight) at four rotary speeds (125, 250, 375, and 500 rpm) on the furrow seedbed parameters when used for strip-tillage was investigated. The experimental blades were mounted on a rotary tiller test unit operating in a reconstituted sandy loam soil travelling at a forward speed of 0.67 m s−1. Analysis of the high-speed video showed that the straight blade reduced the soil carrying and throwing. At 125 rpm all blades produced either an unsatisfactory cloddy seedbed with an irregular furrow bottom and walls or an incomplete furrow. At 500 rpm, considerable amounts of soil were thrown out of the furrow for the conventional and half-width blades which achieved furrow backfills of only 41 and 36%, respectively. The straight blade achieved the fullest backfill at 74% even when operating at 500 rpm. The level of soil pulverisation increased with rotary speed, but was not affected by blade geometry. Each of the blades produced different furrow shapes with a higher furrow volume tilled by the conventional and the straight blades compared to that by the half-width blades. Based on its high backfill and large furrow volume, the straight blade would be the preferred option when undertaking rotary strip-tillage.


      PubDate: 2013-12-07T00:05:04Z
       
  • Intra-operator repeatability of skin marker derived segment measures and
           gait kinematics in healthy pigs
    • Abstract: Publication date: February 2014
      Source:Biosystems Engineering, Volume 118
      Author(s): Sophia Stavrakakis , Jonathan H. Guy , Oliver M.E. Warlow , Garth R. Johnson , Sandra A. Edwards
      There is a lack of biomechanical research into locomotor pathology in pigs despite orthopaedic problems being a major concern for the industry. This study evaluates the intra-operator repeatability of marker placement in pigs undergoing biomechanical investigation. Three pigs were fitted twice per day on five consecutive days with skin markers over anatomical landmarks; data were captured with a 3D optoelectronic system and 10 markers were used here for segment length and gait parameter calculation. There were significant differences between front and hind leg and proximal and distal segment length repeatability. Repeatability showed a similar extent and location variability to human and other quadruped studies. The source of the greatest segment differences was the femoral segment in the hind leg. Segmental differences at the shoulder and elbow joint were limited in this application. For all segments, except the femoral, differences above 0–10 mm were observed at or less than 7% of the marker applications, which may be an acceptable level of disagreement. Gait parameter repeatability generally confirmed the segment length findings and resembled intra-operator achievement in horses. Implications in pigs will depend on the effect size of clinical conditions with an impact on gait parameters. Future studies should determine such effects by recruiting subjects with known clinical conditions whilst controlling for other confounding factors.


      PubDate: 2013-12-07T00:05:04Z
       
  • Editorial Board
    • Abstract: Publication date: December 2013
      Source:Biosystems Engineering, Volume 116, Issue 4




      PubDate: 2013-11-29T00:04:52Z
       
  • Microwave assisted retting – A novel method of processing of
           flax stems
    • Abstract: Publication date: December 2013
      Source:Biosystems Engineering, Volume 116, Issue 4
      Author(s): Gopu Raveendran Nair , Denis Rho , Varoujan Yaylayan , Vijaya Raghavan
      A new method for retting of flax stem was introduced by using microwave energy. The combined effect of pre-soaking, microwave volumetric heating and the non-thermal effect of microwave energy were applied in the retting of flax stem. Effective retting was observed in various combinations of pre-soaking, Microwave treatment times and microwave energy. The samples soaked for 24 and 36 h with microwave treatments of 20 min showed better retting efficiency. Fried tests, Near Infrared analysis and fibre diameter analysis were done to find out the retting efficiency. The effect of non-thermal effect of microwave in flax retting was proved experimentally. Colourimetric tests and tensile strength tests were conducted to compare the quality of fibres after microwave retting and no significant changes in the physical qualities were observed. The water released after pre-soaking was not contaminated because of less microbial activity in short duration of the entire process. In industrial point of view, this method is acceptable because of the ease of recyclability of the pre-soaked water and comparably short duration of the process.


      PubDate: 2013-10-28T04:31:04Z
       
  • Thermal behaviour and kinetic study for woody biomass torrefaction and
           torrefied biomass pyrolysis by TGA
    • Abstract: Publication date: December 2013
      Source:Biosystems Engineering, Volume 116, Issue 4
      Author(s): Shoujie Ren , Hanwu Lei , Lu Wang , Quan Bu , Shulin Chen , Joan Wu
      The thermal decomposition behaviour and kinetics of Douglas fir sawdust torrefaction and torrefied sawdust pyrolysis were investigated using a thermogravimetric analyser (TGA). The mass loss of samples in torrefaction was highly related to the torrefaction temperature. The two-step reaction model fitted well for Douglas fir sawdust torrefaction. The activation energies of the first and second reaction stages were 112 kJ mol−1 and 150 kJ mol−1, respectively. Torrefied biomass exhibited different thermo decomposition behaviours compared to untreated biomass. The start point of torrefied biomass decomposition was shifted and the degree of shift increased with the severity of torrefaction. The final biochar yield of torrefied biomass was also increased with the increase of torrefaction temperature. Derivative thermogravimetric (DTG) curves showed that the shoulder of hemicelluloses decomposition in torrefied biomass pyrolysis was eliminated. The decomposition rate of torrefied biomass has a decreasing trend due to the mass depletion in torrefaction. A first-order one-step global model with the average activation energies in the range of 195–204 kJ mol−1 can describe the raw and torrefied biomass pyrolysis. The kinetic analysis also showed that the torrefied biomass pyrolysis from high torrefaction temperature might be multiple-step reactions.


      PubDate: 2013-10-28T04:31:04Z
       
  • DEM simulation and physical testing of rice seed impact against a grain
           loss sensor
    • Abstract: Publication date: December 2013
      Source:Biosystems Engineering, Volume 116, Issue 4
      Author(s): Zhao Zhan , Li Yaoming , Liang Zhenwei , Gong Zhiqiang
      A triaxial ellipsoidal particle model was established according to the physical properties of rice seed, and its impact behaviour against a grain loss sensor was simulated using the discrete element method (DEM). The contact criterion was developed directly by solving the intersection equations, and the contact forces were calculated according to elastic–plastic and Mindlin models. It was shown that the seeds may perform translational and rotational motion in a 3D space after the impact. With the influences of particle shape, orientation and angle of incidence, three typical impact processes were found: single impact, multiple impacts in a short-time, and continuous impacts. Two important parameters for the design of loss sensors are the maximum normal impact force F n max and the force rise-time t r. Simulations showed that an increase in particle ellipticity strongly enlarged the differences in F n max. As the ellipticities increased from unity to 2, the defined force ratio η decreased from 100% to about 40%, and this value decreased to less than 20% when ellipticities continuously increased from 2 to 4. Tangential velocity led to an asymmetric variation of η. t r was generally distributed between 12 and 54 μs. In laboratory tests, rice seeds were allowed to free fall onto a loss sensor from a height of 320 mm. Results indicated that the peak output voltage was fluctuated in 1.5–4.5 V, and the rise-time was in 14–48 μs.


      PubDate: 2013-10-28T04:31:04Z
       
  • Using continuous-curvature paths to generate feasible headland turn
           manoeuvres
    • Abstract: Publication date: December 2013
      Source:Biosystems Engineering, Volume 116, Issue 4
      Author(s): Dennis Sabelhaus , Frank Röben , Lars Peter Meyer zu Helligen , Peter Schulze Lammers
      Today's agricultural engineering is characterised by automation and information technology. Automatic steering systems have become an adequate tool for guidance on a track with accuracy in the range of centimetres. Consequently, the transition from track to track must be planned exactly, so that the target track is achieved precisely. A method which can generate turn trajectories – so-called headland turns - with smooth transition and a fast computation performance is investigated. The method is based on the continuous-curvature path planning in the field of mobile robotics and is connected to the specific agronomic requirements. In this context the clothoid construction element constitutes the main construction element. It enables the smooth connection from zero curvature to maximal curvature which represents the reciprocal of the minimal turning radius. In totality, a manoeuvre can be planned with modified Dubins curves, both going backwards and forwards is feasible with modified Reeds and Shepp curves. Seven different manoeuvres are useful from an agronomic point of view. It is shown that all turn manoeuvres are feasible with this method. Also an analysis regarding the trajectory length, the headland width and the operation time is shown.
      Graphical abstract image

      PubDate: 2013-10-15T23:05:04Z
       
  • Effect of alkaline pretreatment on chemical composition of lignocellulosic
           biomass using radio frequency heating
    • Abstract: Publication date: December 2013
      Source:Biosystems Engineering, Volume 116, Issue 4
      Author(s): Kingsley L. Iroba , Lope G. Tabil , Tim Dumonceaux , Oon-Doo Baik
      The very nature of lignocellulosic biomass presents resistance and recalcitrance to biological and chemical degradation during enzymatic hydrolysis and the subsequent fermentation process. This leads to a very low conversion rate, which makes the process economically unfeasible. In this study, alkaline (NaOH) pretreatment was applied on barley straw, using radio-frequency-based dielectric heating to enhance accessibility and digestibility during the subsequent stage of enzymatic hydrolysis. Three levels of temperature (70, 80, and 90 °C), five levels of biomass:NaOH solution ratio (1:4, 1:5, 1:6, 1:7, and 1:8), 1 h equilibration time, screen size of 1.6 mm, 1% w/v NaOH concentration, and 20 min residence time were used for the pretreatment. The effect of the alkaline pretreatment was evaluated through chemical composition analysis of the pretreated and non-treated biomass samples. The use of NaOH solution and the biomass:NaOH solution ratio played a vital role in the breakdown of the lignified matrix. The ratio 1:6 at the four temperatures studied was determined to be the optimal treatment conditions. Radio frequency-assisted alkaline pretreatment resulted in lower acid insoluble lignin and higher total acid soluble lignin moieties. Based on the obtained data, we predict that this pretreatment will decrease the required amount and cost of enzymes by up to 64% compared to using non-treated biomass.


      PubDate: 2013-10-15T23:05:04Z
       
  • Modelling and simulation of cross flow grain dryers
    • Abstract: Publication date: December 2013
      Source:Biosystems Engineering, Volume 116, Issue 4
      Author(s): O.A. Khatchatourian , H.A. Vielmo , L.A. Bortolaia
      A mathematical model, algorithm, and computer program were developed to simulate the performance of cross flow grain dryers and cross flow dryers with energy saving. The mass and heat transfer processes were described by a system of four non-linear partial differential equations. This system of equations was solved by the MacCormack method with time splitting. The Neumann method was used to determine convergence. The source-terms in these equations were computed by auxiliary semi-empirical equations obtained by experimental data from thin layer drying. Equipment developed to obtain these data permitted variation of the initial air humidity, temperature, and velocity. Fixed bed drying experiments were conducted to validate the model. Simulations using various control regimens were made to determine the impact on energy consumption and cross flow dryer performance due to recycling air exhausted from various stages of the dryer. An iterative process was used to determine the initial conditions at the entrance to each section of the dryer. The computer simulations were used to evaluate the non-uniformity of temperature and grain moisture content distributions in dryers, the duration of the drying process and the energy efficiency for each geometry and control regimen.


      PubDate: 2013-10-15T23:05:04Z
       
  • Capacitance and near-infrared techniques for the real-time moisture
           measurement of broiler litter
    • Abstract: Publication date: December 2013
      Source:Biosystems Engineering, Volume 116, Issue 4
      Author(s): Simerjeet S. Virk , John P. Fulton , Oladiran O. Fasina , Timothy P. McDonald
      The feasibility of capacitance and near-infrared (NIR) techniques for measuring the real-time moisture content (MC) of broiler litter was evaluated. Data collection consisted of recording differential voltage signal and spectral absorption values (1200–2200 nm) for a capacitance and a NIR sensor, respectively, for broiler litter samples within 19.3%–75.1% d.b. (16.2%–42.9% w.b.) MC. Initial data analysis indicated that litter density impacted the capacitance sensor voltage. The sensor generated a linear response between 19.3% and 45.8% d.b. MC at the given bulk density (BD) and the operating moisture range further decreased as the litter BD increased. NIR data analysis indicated that the absorption bands within the 1400–1440 nm and 1900–1950 nm wavelength regions were highly correlated to the litter MC. Linear regression models relating the output data (differential voltage and absorption spectral values for capacitance and NIR, respectively) to the litter MC exhibited a high linear correlation (R 2 = 0.89–0.99). Model validation results also generated high correlation values (R 2 = 0.87–0.95) between the predicted and measured MC's. Overall results suggested that the NIR technique performed better than the capacitance technique because of its ability to provide rapid, non-intrusive and density-independent measurements within the selected moisture range. The NIR technique is recommended for future real-time moisture measurement on litter conveying and application equipment.


      PubDate: 2013-10-11T23:04:34Z
       
  • Application of convex streamline theory to circular-crested weir
    • Abstract: Publication date: December 2013
      Source:Biosystems Engineering, Volume 116, Issue 4
      Author(s): Jahanshir Mohammadzadeh-Habili , Manouchehr Heidarpour
      Circular-crested weirs are overflow structures that can be used for flow measurement, water level control in open channels and flood control in reservoirs. Combining Newton's second law for a rectangular fluid particle on a convex streamline with Bernoulli's equation, the differential equation of velocity profile at crest section of circular-crested weir is obtained. This equation was used to derive the discharge coefficient, crest velocity profile and crest pressure profile of the weir. A wide range (0.44 ≤ H/R ≤ 7.56) of existing experimental data of circular-crested weir is used to evaluate the obtained equations. Results of the study indicated that obtained equations have good agreement with experimental data. Also, in comparison with Dressler and potential flow theories, proposed theory predicts the crest velocity profile with the better precision.


      PubDate: 2013-10-11T23:04:34Z
       
  • An improvement in the efficiency of olive pomace oil extraction using an
           optimal pooling decision model
    • Abstract: Publication date: December 2013
      Source:Biosystems Engineering, Volume 116, Issue 4
      Author(s): Pedro Sánchez-Martín , Guiomar Rayón-Durán
      When olives are harvested, local presses dispose of olive husk, the residue of the pressing process, transporting it to Olive Waste Management Centres (OWMC). Once there, the husk is emptied into pools to be classified, stored and then processed to obtain olive pomace oil and thermal and electric energy. Olive pomace oil extracted mechanically offers benefits over oil extracted chemically, both in terms of its culinary properties and in terms of its market price. This paper describes a decision model whose objective function seeks to maximise the quantity of olive pomace oil by improving the efficiency of mechanical extraction at OWMC. To improve this efficiency, a husk management decision model has been developed to cope with nonlinear husk pooling relationships over a multistage period. The convergence difficulties of mixed integer nonlinear optimisation in the decision model are dealt with by means of a novel multistage iterative linear formulation based on the first order Taylor approximation. The output accuracy and convergence of the proposed model is compared with that of a relaxed mixed integer nonlinear optimisation model. Finally, a real case study located in the south of Spain is described. In this study, by using the linear decision model the total amount of olive pomace oil was 10% greater than that obtained from the current procedure implemented at OWMC.


      PubDate: 2013-10-11T23:04:34Z
       
  • Energy efficacy analysis of a mechanical shaker in sweet cherry
           harvesting
    • Abstract: Publication date: December 2013
      Source:Biosystems Engineering, Volume 116, Issue 4
      Author(s): Long He , Jianfeng Zhou , Xiaoqiang Du , Du Chen , Qin Zhang , Manoj Karkee
      To obtain the baseline information for designing a high efficiency mechanical sweet cherry harvester, a series of dynamic and harvesting tests were conducted in orchards. In the dynamic test, a mechanical shaker was used to shake branches of target trees. Three trees were randomly selected for the study and each studied branch of the tested trees was divided into three response zones where one accelerometer was mounted on each zone to record the response to the input excitations. The kinetic energy induced by the input excitation in each response zone was tracked during the course of energy delivery. Results from these dynamic response tests showed that the kinetic energy delivered to an excited branch on average accounted for 60%, 77%, 92% and 95% of input excitation energy at shaking frequency of 6, 10, 14, and 18 Hz, respectively. Harvesting tests were also conducted using shaking frequencies of 14 and 18 Hz, and test trees were shaken using a sequence of four 5 s long intermittent excitations. On average, the shaker removed 67 ± 16% of the fruit during the first cycle of 18 Hz shaking, and 42 ± 16% with 14 Hz shaking. The shaker energy efficacy, defined as the percentage fruit removal per kilo-joule of input energy, was 6.9 ± 2.2% kJ−1 and 7.4 ± 1.3% kJ−1 during the first cycle of 14 and 18 Hz shaking, respectively. The results indicated that the 18 Hz shaking frequency reached higher fruit removal efficiency when compared to the 14 Hz shaking frequency with similar energy efficacy.


      PubDate: 2013-10-11T23:04:34Z
       
  • Spray liquid distribution and biological efficacy of commercially
           available nozzles used for precision weed control
    • Abstract: Publication date: December 2013
      Source:Biosystems Engineering, Volume 116, Issue 4
      Author(s): Peter K. Jensen , Ivar Lund , David Nuyttens
      The aim of this study was to test the application accuracy of commercially available hydraulic nozzles for the purpose of applying herbicides to decimetre sized cells. Based on various technical performance tests, 3 nozzles were selected for further biological efficacy tests. From the technical tests, nozzle output and nozzle height to achieve a 100-mm-wide spray swath were determined. In biological tests, efficacy and application accuracy controlling Matricaria perforata at the cotyledon stage with glyphosate in 100mm×100mm cells were tested. Efficacy was measured inside the square, in the border zone and just outside the square. The study showed that with commercially available nozzles, it is possible to apply a herbicide to a 100mm×100mm cell at an application speed of 1–2ms−1 with a high precision and with only a limited proportion of the spray being lost outside the intended target area. The biological efficacy obtained in the central part of the cell was slightly reduced compared to a broadcast application. A tracer study revealed that this could be explained by a reduced nozzle output compared to the measured output in the technical test. The reduction was probably caused by a much shorter nozzle operating time during application to the cell. The valves used in this study therefore should be replaced with faster acting valves.


      PubDate: 2013-10-11T23:04:34Z
       
  • Feasibility study on the use of attenuated total reflectance infrared
           spectroscopy as high throughput screening tool to phenotype single barley
           seeds (Hordeum vulgare L.)
    • Abstract: Publication date: December 2013
      Source:Biosystems Engineering, Volume 116, Issue 4
      Author(s): D. Cozzolino , S. Roumeliotis , J. Eglinton
      Knowledge of the chemical and structural differences between barley (Hordeum vulgare L.) varieties and breeding lines might lead to an understanding of the reasons for these differences among genotypes in relation to their malting properties. The aim of this study was to evaluate the use of attenuated total reflectance mid infrared (ATR-MIR) spectroscopy combined with univariate and multivariate methods as a high throughput screening tool to phenotype single seeds of barley. Varieties that yield high malting quality (hot water extract (HWE) > 80%) showed relatively high non-structural carbohydrates (e.g. starch) to protein and non-structural to structural (e.g. cellulose) carbohydrates ratios compared with those samples having moderate HWE (78% < HWE < 80%). The use of ATR-MIR spectroscopy and in particular the use of ratios at specific wavenumbers can provide useful information about the biophysical and chemical characteristics of the grain.


      PubDate: 2013-10-11T23:04:34Z
       
  • Thermal balance analysis of activated-sludge process for pig slurry
           treatment
    • Abstract: Publication date: December 2013
      Source:Biosystems Engineering, Volume 116, Issue 4
      Author(s): Peng Wang , Kikue Yokoo , Yuichiro Wakiya , Munehiro Tanaka
      The potential for operating an activated-sludge process (ASP) at higher temperatures with the aim of improving the hygienic qualities of the treated effluent was studied in terms of thermal balance. A thermal balance model for activated-sludge reactors (ASRs) was developed to simulate thermal changes in treating pig slurry, especially with respect to heat exchanges and temperature variations within the reactor. The model was validated by using data from a treatment plant and weather station. The developed model matched in situ temperature data with a root mean square error of 0.60 °C. It indicated the heat gained from solar radiation (308.435 MJ d−1) and biological reaction (217.773 MJ d−1) was significant, as was the heat dissipated from the slurry surface (273.847 MJ d−1) and slurry flow (214.522 MJ d−1). The model accurately reproduced the thermal balance of ASR and these results showed that the total heat gain resulted in a temperature increase of 3.87–5.15 °C d−1 in the reactor, but this effect was offset by heat loss. These results indicated the need for effective thermal insulation to be installed if an ASP was to be operated at higher temperatures.


      PubDate: 2013-10-11T23:04:34Z
       
 
 
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