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21.
Reporting standards for biofilter performance studies 总被引:1,自引:0,他引:1
John Colt Jonathan Lamoureux Richard Patterson Gary Rogers 《Aquacultural Engineering》2006,34(3):377-388
The development of standardized rating and design procedures for biological filters will require that filter performance be evaluated and reported in a standardized manner. This article recommends draft reporting standards for biofilter performance studies. It is important that critical parameters are defined and reported in a standard manner, both in terms of definition, variable names, and units. Depending on the type and scale of an experiment, reporting of certain parameters will be either mandatory or optional. Basic principles of experimental design, statistical analysis, and randomization must be followed. Experimental protocols are recommended to ensure the accuracy of measured or computed parameters. The development of this reporting standard is being organized through the Standards and Reporting Committee of the Aquaculture Engineering Society (AES). It is anticipated that a revised version of these standards will be incorporated into the Guide to Authors for Aquacultural Engineering. 相似文献
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张军华 《湖南农业大学学报(自然科学版)》2014,(3):80-86
以2004~2011年沪深A股上市公司为样本,研究权益资本成本的行业差异以及行业特征对权益资本成本的影响。研究发现:行业门类层面和制造业次类层面的权益资本成本差异显著,这种差异在时序上较为稳定。行业竞争程度越低,权益资本成本越小,体现了产品市场竞争的特质性风险效应,行业收益波动和行业成长性分别对权益资本成本产生显著的正向影响和负向影响。企业会计准则的改革强化了行业因素对权益资本成本的影响。 相似文献
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Trond Rafoss Knut Sælid Lars Fredrik Gyland 《Computers and Electronics in Agriculture》2010,74(2):336-340
The threat posed by invasive alien species to global crop production and biodiversity is recognized as one of the major drivers of global change today. Here we report on a successful implementation and operational use of new technology to support risk- and crisis management in the case of fighting an invasive plant disease. The open geospatial standards Web Feature Service Transaction (WFS-T) was implemented in software for GPS-enabled mobile phones communicating with a GeoServer backend in order to track down and eradicate disease outbreaks and susceptible host plants. This new technology offering georeferenced events online from field provides new possibilities for real time action in risk and crisis management. 相似文献
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The analysis distinguishes two types of standards for defining organic produce; process standards and product standards. Process standards define organic products by the method and means of production. Product standards define organic by the physical quality of the end product. The National Organic Program (NOP) uses process standards as the basis for defining organic. However, the situation is complicated by agricultural production practices, which sometimes result in the migration of NOP prohibited substances from conventional to organic fields. When this interaction alters the value of the product or the costs of production, a production externality is said to exist. Defining organic using process, rather than product standards, influences the burden and character of production externalities. The NOPs emphasis on process standards reduces the likelihood that production externalities will emerge.B. James Deaton is an Assistant Professor in the Department of Business and Agricultural Economics, University of Guelph, Canada. His research examines environmental and natural resource issues. He is particularly interested in the manner in which laws, rules, and standards influence environmental quality, natural resource use, and economic development. Additional research examines the relationship between different forms of private property and economic development, public support for various criteria used to preserve farmland, and the social construction of production externalities in agriculture. Prior to his PhD training, he worked on economic development projects in Lesotho (Southern Africa) and the Appalachian region of eastern Kentucky.John P. Hoehn is a Professor of Environmental and Natural Resource Economics in the Department of Agricultural Economics, Michigan State University. His teaching and research activities address environmental and natural resource policies, benefit-cost analysis of environmental improvements, methods for valuing non-market goods, improved institutions for protecting, managing, and using environmental resources, and the economics of ecological resources. He teaches core courses in the departmental and university-wide graduate programs in environmental and resource economics. 相似文献