991 resultados para Agricultural processing


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Published by: Agricultural Research Service, U.S. Dept. of Agriculture, 1982-1987; by: Sugar Processing Research Institute, 1988-

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This research develops a low cost remote sensing system for use in agricultural applications. The important features of the system are that it monitors the near infrared and it incorporates position and attitude measuring equipment allowing for geo-rectified images to be produced without the use of ground control points. The equipment is designed to be hand held and hence requires no structural modification to the aircraft. The portable remote sensing system consists of an inertia measurement unit (IMU), which is accelerometer based, a low-cost GPS device and a small format false colour composite digital camera. The total cost of producing such a system is below GBP 3000, which is far cheaper than equivalent existing systems. The design of the portable remote sensing device has eliminated bore sight misalignment errors from the direct geo-referencing process. A new processing technique has been introduced for the data obtained from these low-cost devices, and it is found that using this technique the image can be matched (overlaid) onto Ordnance Survey Master Maps at an accuracy compatible with precision agriculture requirements. The direct geo-referencing has also been improved by introducing an algorithm capable of correcting oblique images directly. This algorithm alters the pixels value, hence it is advised that image analysis is performed before image georectification. The drawback of this research is that the low-cost GPS device experienced bad checksum errors, which resulted in missing data. The Wide Area Augmented System (WAAS) correction could not be employed because the satellites could not be locked onto whilst flying. The best GPS data were obtained from the Garmin eTrex (15 m kinematic and 2 m static) instruments which have a highsensitivity receiver with good lock on capability. The limitation of this GPS device is the inability to effectively receive the P-Code wavelength, which is needed to gain the best accuracy when undertaking differential GPS processing. Pairing the carrier phase L1 with the pseudorange C/A-Code received, in order to determine the image coordinates by the differential technique, is still under investigation. To improve the position accuracy, it is recommended that a GPS base station should be established near the survey area, instead of using a permanent GPS base station established by the Ordnance Survey.

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This study tested whether contract farming or farmers professional cooperatives (FPCs) improved the social benefit of pork production and income of breeding farmers in China. The main concern of this study is whether institutional arrangement like contract farming or FPCs actually improved the welfare of farmers as expected. To answer this question accurately, we estimated the differentiated market demand of pork products in order to quantify the benefit by transaction types. Our study finds that contract farming or FPCs improved the benefits of pork products, but farmer's income remained lower than that of traditional transaction types. This finding is new in terms of quantifying distribution of the economic values among sales outlets, agro-firms and farmers. It is more reliable because it explicitly captures impacts from both demand side and supply side by structural estimation. In practice, we need to keep it mind the bargaining power of small farmers will not improve instantly even when the contract farming or FPCs are introduced.

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Cassava is one of the major food crops in Nigeria, with multiple uses from human consumption to industrial applications. This study explores the potential of cassava in Nigerian agriculture based on a review of cassava development policies; performs a trend analysis of the cultivation area, production, productivity, and real price of cassava and other competing crops for the period 1961–2013; identifies the sources of growth in production; and examines the production constraints at the local level based on a survey of 315 farmers/processors and 105 marketers from Delta State. The results revealed that several policies and programmes were implemented to develop the cassava sector with mixed outcomes. Although cassava productivity grew at 1.5% per annum (p.a.) during the post-structural adjustment programme period (1993–2013), its real price declined at a rate of 3.5% p.a. The effect of yield is the main source of growth in production, contributing 76.4% of the total growth followed by the area effect (28.2%). The cassava sector is constrained by inadequate market infrastructure, processing facilities, and lack of information and unstable prices at the local level. The widespread diffusion of improved tropical manioc selection technologies and investments in market and marketing infrastructure, processing technologies, irrigation/water provision and information dissemination are recommended to enhance the potential of the cassava sector to support agricultural growth in Nigeria.

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The technical, environmental and economic potential of hemp fines as a natural filler in bioplastics to produce biocomposites is the subject of this study – giving a holistic overview. Hemp fines are an agricultural by-product of the hemp fibres and shives production. Shives and fibres are for example used in the paper, animal bedding or composite area. About 15 to 20 wt.-% per kg hemp straw results in hemp fines after processing. In 2010 about 11,439 metric tons of hemp fines were produced in Europe. Hemp fines are an inhomogeneous material which includes hemp dust, shives and fibre. For these examinations the hemp fines are sieved in a further step with a tumbler sieving machine to obtain more specified fractions. The untreated hemp fines (ex work) as well as the sieved fractions are combined with a polylactide polymer (PLA) using a co-rotating twin screw extruder to produce biocomposites with different hemp fine content. By using an injection moulding machine standard test bars are produced to conduct several material tests. The Young’s modulus is increased and the impact strength reduced by hemp fines. With a content of above 15 wt.-% hemp fines are also improving the environmental (global warming potential) and economic performance in comparison to pure PLA.

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Lignocellulosicwaste from the pineapple production is a raw material useful for the xylose production by hydrolysis and it can be converted to xylitol. The objective of this work was to study the hydrolysis of pineapple peel with sulfuric acid at variable concentration (2-6%), reaction time (0-350 min) and temperature at 98 ˚C. The concentration of xylose, glucose and degradation products as acetic acid and furfural was determined. Optimal conditions found for hydrolysis were 6% H2SO4 at 98 ˚C for 83 min which yield was 26,9 g xylose/L, 2,61 g glucose/L, 7,71 g acetic acid/L and 0,29 g furfural/L.

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Very high resolution remotely sensed images are an important tool for monitoring fragmented agricultural landscapes, which allows farmers and policy makers to make better decisions regarding management practices. An object-based methodology is proposed for automatic generation of thematic maps of the available classes in the scene, which combines edge-based and superpixel processing for small agricultural parcels. The methodology employs superpixels instead of pixels as minimal processing units, and provides a link between them and meaningful objects (obtained by the edge-based method) in order to facilitate the analysis of parcels. Performance analysis on a scene dominated by agricultural small parcels indicates that the combination of both superpixel and edge-based methods achieves a classification accuracy slightly better than when those methods are performed separately and comparable to the accuracy of traditional object-based analysis, with automatic approach.