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21.
The classification of agricultural tillage systems has proven challenging in the past using traditional classification methods due to the similarity of spectral reflectance signatures of soils and senescent crop residues. In this study, five classification methods were examined to determine the most suitable classification algorithm for the identification of no-till (NT) and traditional tillage (TT) cropping methods: minimum distance (MD), Mahalanobis distance, Maximum Likelihood (ML), spectral angle mapping (SAM), and the cosine of the angle concept (CAC). A Landsat ETM+ image acquired over southern Michigan and northern Indiana was used to test these classification methods. Each classification method was validated with 293 ground truth sampling locations collected commensurate with the satellite overpass. Classification accuracy was then assessed using error matrix analysis, Kappa statistics, and tests for statistical significance. The results indicate that of the classification routines examined, the two spectral angle methods were superior to the others. The cosine of the angle concept algorithm outperformed all the other classification routines for tillage practice identification and mapping, yielding an overall accuracy of 97.2% (Kappa=0.959). 相似文献
22.
This paper presents a mathematical programming model for the optimal design of water networks in the agriculture. The proposed model is based on a new superstructure that includes all configurations in terms of use, reuse and regeneration of water in a field constituted by a number of croplands. The model also includes the allocation of pipelines, pumps and storage tanks in different irrigation periods. The objective function consists in maximizing the annual profit that is formed by the economic incomes owing to the crop sell minus the costs for fresh water, fertilizer, storage tanks, treatment units, piping and pumping. The proposed multi-period optimization problem is formulated as a mixed integer non-linear programming formulation, which was applied to a case study to demonstrate the economic, environmental and social benefits that can be obtained. 相似文献
23.
《国际互联网参考资料服务季刊》2013,18(2-3):37-53
Abstract The World Wide Web (WWW) has a decentralized information environment and a non-linear (hypertext) information structure. This non-linear structure allows users to retrieve information at many different levels but also increases the difficulty of information retrieval. Unlike a well-developed CD-ROM database, the WWW does not have a controlled searching environment and information can be indexed in many different ways. It takes a well planned search strategy to perform an effective search in the labyrinth of the WWW. The SIRO (Systematic Information Retrieval/Organization) model offers a research planning process designed specifically for information seekers in the agricultural disciplines. The intention is to enhance search results and organize retrieved information. This process starts with the identification of the information structure on the WWW, then proceeds by organizing and analyzing information in a visual diagram or a “thinking map.” This process leads searchers to logical sources on the WWW and a systematic analysis of the result. 相似文献
24.
《Food Control》2017
To test the market viability of a non-GMO topical RNAi insect control, we conducted a Willingness-To-Pay (WTP) survey in the USA, Canada, Australia, France, and Belgium to elicit whether consumers need a premium or discount for: (1) a hypothetical GMO rice variety using the Bacillus thuringiensis (Bt) gene for insect control; and (2) a hypothetical non-GMO rice variety using topical RNAi spray for insect control. The survey was designed based on a Multiple Price List (MPL) format where respondents selected their preferred insect control technology; i.e., conventional, GMO Bt, or non-GMO RNAi, at different prices. Participants' responses were analyzed using an interval regression model to generate WTP premiums and discounts for each country with control variables for demographic influences. Further, we asked consumers their Willingness-To-Consume (WTC) food produced with GM and RNAi technologies respectively and evaluated WTC differences using a McNemar matched pairs test in each country. The results from our study clearly show that: (1) consumers in the USA, Canada, Australia, and France still require a discount for rice produced with topical RNAi compared to conventionally-produced rice (p < 0.05), (2) consumers in the USA, Canada, Australia, France, and Belgium would need an additional 30–40% discount to purchase Bt rice over rice produced with topical RNAi (p < 0.05), and (3) consumers in all countries were more willing to consume rice produced with non-GM RNAi than with GM Bt technology (p < 0.05). These findings suggest consumers differentiate among biotechnology solutions and consumers may prefer topical RNAi insect control to transgenic GMO insecticides. 相似文献
25.
In this paper we argue that insights from feminist perspectives, particularly in the form of an ethics of care, have a number of advantages when used as a lens through which to consider questions relevant to the governance of emerging technologies. We highlight how an emphasis on central themes of importance in feminist theory and care ethics such as relationality, contextuality, dependence, power, affect, and narrative can shine a light on a number of salient issues that are typically missed by the dominant and largely consequentialist risk assessment frame. We argue that the care ethics lens is a better fit when technologies are understood not simply as devices designed to create a certain end experience for a user but as transformative systems that smuggle in numerous social and political interests. The advantages of these care ethics themes for emerging technologies are illustrated through a detailed consideration of agricultural biotechnology. We show how the feminist care ethics lens might have anticipated the very questions that have proved themselves to be the sticking points for this technology. We therefore suggest that applying a care ethics lens can significantly broaden the frame of appraisal processes used for the governance of emerging technologies and usefully grant legitimacy to questions and concerns that are prominent in public discourse but typically left out of practices of risk assessment. 相似文献
26.
This study sought to quantify and characterize cassava waste as fuel. The wastes from three cultivars were collected to study and were divided into three distinct parts of the cassava plant: seed stem, thick stalks, and thin stalks. Physical and chemical analyzes were carried out to determine the elemental composition of the waste: volatile matter; fixed carbon; ash; moisture; lignin; cellulose; hemicellulose; ash composition and higher heating value were determined. We conducted a thermogravimetric analysis in oxidizing and inert atmospheres to study the behavior of the waste as fuel. The root productivity obtained ranged from 7.7 to 13.0 t ha−1 yr−1 on a dry basis (db), and the ratio between waste and roots varied from 0.36 to 0.91. The physical and chemical properties of cassava waste are analogous to those of woody biomass regarding the elemental composition, the higher heating value, and thermogravimetric analysis. Ash content varied from 2.5% to 3.5%, reaching around 6.0% in samples unwashed. Approximately 60% of the ashes are alkali oxides, especially P2O5, K2O, and CaO, which have low melting points. The alkali index calculated suggests that there is a strong tendency that the combustion process leads to ash fouling and the formation of ash deposits. 相似文献
27.
《Food Control》2015
Mislabelling of seafood products has been documented in numerous countries for over three-quarters of a century. With a trend towards increased consumption of seafood, the informed consumer demands accurately labelled products that provide full disclosure of composition. DNA barcoding can be used to accurately identify a seafood product to species based on its genetic signature, and so provides a means to test the authenticity and accuracy of seafood labelling. This can be especially useful for products such as fillets which have few or no unambiguous identifying characters, and can easily be mislabelled. We investigated labelling accuracy in seafood retailers in Tasmania, Australia. Thirty-eight seafood products were obtained from seafood retailers, sequenced for the barcoding gene region cytochrome oxidase subunit 1(CO1), and subsequently identified to species level by querying GenBank and Barcode of Life Data Systems (BOLD) DNA sequence records. Results were compared with standard fish names (SFN) prescribed under the Australian Fish Names Standard (AFNS) and FishBase. Of the 38 samples, none were deemed to have been mislabelled under Australian regulation, although in some cases naming discrepancies and ambiguity may cause confusion for some consumers. Our work, while reflecting high standards in Tasmanian seafood, highlights the need for mandatory standard labelling across all seafood products so as to eliminate any possible misrepresentation. 相似文献
28.
Chen Sun 《The International journal of environmental studies》2013,70(2):232-240
Livestock and poultry husbandry is a major source of agricultural pollution in China. Thus far, national-scale approaches to estimating pollutant loads from livestock and poultry rearing remain limited. This impedes effective water quality assessment and relevant policy making. Applying unit load and export coefficient modelling, we estimated pollutant loads from livestock and poultry raising from 2000 to 2010. Results show that the total annual pollutant loads generated from the faeces and urine of livestock and poultry in 2010 had a chemical oxygen demand of 78.2?million metric tonnes; biochemical oxygen demand of 72.7?million tonnes; ammonia nitrogen of 7.4?million tonnes; total phosphorus of 6.0?million tonnes; and total nitrogen of 18.0?million tonnes. Livestock and poultry husbandry has been one of the main pollution sources in China. The significant contributors are pigs and cattle. In particular, pollution from livestock and poultry raising in China spatially overlaps with industrial and domestic pollution. South eastern regions face the difficult challenge of controlling and managing agricultural, industrial and domestic pollution. 相似文献
29.
Sulfonated Beet Pulp as Solid Catalyst in One-Step Esterification of Industrial Palm Fatty Acid Distillate 下载免费PDF全文
Farahnaz Eghbali Babadi Soraya Hosseini Salman Masoudi Soltani Mohamed Kheireddine Aroua Ahmad Shamiri Mahtab Samadi 《Journal of the American Oil Chemists' Society》2016,93(3):319-327
In this research a new heterogeneous catalyst has been prepared for biodiesel production. The catalyst was prepared by sulfonating industrial sugar waste. Unlike homogeneous catalysts, which require further purification and separation from the biodiesel production reaction media, this inexpensive synthetic catalyst does not need to go through an additional separation process. This advantage consequently minimizes the total application costs. The catalyst was prepared by partially carbonizing sugar beet pulp at 400 °C. The carbonization product was then sulfonated with concentrated H2SO4 vapor in order to produce a solid catalyst. The prepared catalyst was used in the esterification reaction between palm fatty acid distillate (PFAD) and methanol. The effects of the temperature, methanol/PFAD ratio, reaction time and catalyst dosage on the efficiency of the production were individually investigated. The optimum biodiesel production occurred at 85 °C, a reaction time of 300 min, catalyst dosage of 3 g and methanol/PFAD ratio of 5:1 (mol/mol), lowering the acid value from 198 to 13.1 (mg KOH/g oil) or the equivalent, with a fatty acid methyl ester yield of around 92 %. The results suggest that the synthesized inexpensive catalyst is useful for biodiesel production from PFAD. 相似文献
30.