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91.
This study aims to characterize the different types of certification in the Brazilian citriculture as well as analyze the major changes in the market. The paper also has the objective to discuss how social and environmental factors influence the demand for food certifications and the sustainability and ethics aspects in the field. Therefore, a literature review on the subject was carried out as well as a qualitative research using interviews with certifiers, governmental institutions, farmers, cooperatives and producer associations. The certification is becoming mandatory for those working in foreign markets and for those working nationally; it can be a competitive differential. The organic certification in citriculture shows the highest number of growers. Companies with large areas of citrus and the orange juice processing industry are adhering to this certification in order to maintain themselves competitive in the market. There is an enormous potential of Brazilian citriculture certification, because the certified area is still less than 6 % of the total area. Certification reduces the asymmetry of information and consists of an important step towards sustainability although incapable of solely guaranteeing it.  相似文献   
92.
Environmental Economics and Policy Studies - In this paper, we investigate the economically optimal regulation of aquaculture production. The time between releasing and harvesting fish (rotation...  相似文献   
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This paper compares individual (split) and central systems of air-conditioning in a life cycle perspective, taking into account the environmental impacts and resource consumption during resource extraction, material production, production of the air-conditioning units, their use, disposal and recycling. Life cycle assessment (LCA) is used in conducting this comparison.

Central systems have a longer lifetime than individual systems, lower electricity consumption and maintenance requirements during the use phase, and a higher recycling potential during the disposal phase. However, to transfer cool air, central systems use a large quantity of water pipes or air ducts, the production of which contributes significantly to resource use. The LCA study reveals that, on the whole, the central systems generally use less resources than split systems and result in lower environmental impacts.

The paper suggests a need for producers of air-conditioners to consider a change from being suppliers of air-conditioning hardware to being suppliers of cool air in order to overcome the initial cost constraints of central systems and realize their environmental and economic improvement potential to the benefit of the environment, and the industry as well as customers.  相似文献   
95.
Increasing land consumption and loss of biodiversity make it particularly important that protected areas fulfil their function. This, however, is often impaired by insufficient political and financial support. This study investigates how existing protected area management capacities can be used more effectively in a prompt and lasting manner. Therefore, data from protected area management effectiveness evaluations were analysed. Efficient workflows and teamwork were identified to be key capacities for effective management. Simultaneously, deficient financial and social security, lack of incentives and inflexible management structures prevent the productive use of existing capacities. In order to improve the situation, greater attention should be given to intangible assets. Additionally, protected area managers and employees must be enabled to be more self-reliant and self-responsible in order to foster a lasting learning process.  相似文献   
96.
The ecology of small, gelatinous zooplankton is not integrated into management of Dogger Bank (54° 00′ N, 3° 25′ E to 55° 35′ N, 2° 20′ E). In pursuit of this goal, gelatinous zooplankton and their potential prey were sampled along a transect across the bank on June 10–16, 2007. Eleven species of small medusae and ctenophores were collected, with six abundant taxa occurring in greater numbers below the thermocline and in the shallower, southeastern portion of the bank. There were no statistically significant diel changes in distribution. In contrast, potential prey were distributed more evenly across the bank and throughout the water column. Isotopic analyses revealed that gelatinous zooplankton fed on both smaller (100–300 μm) and larger (>300 μm) mesozooplankton, but also potentially on each other. These ecological insights suggest that small medusae and ctenophores should be integrated into sustainable management of Dogger Bank.  相似文献   
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Iron water treatment residues are a free by-product with high concentration of iron oxides Iron water treatment residues has a large potential for arsenic sorption Soils are highly contaminated by arsenic at wood preservation sites Iron water treatment residues were added to hot spots contaminated with arsenic The addition led to significant decrease in leaching of arsenic from the contaminated soil Iron water treatment residues (Fe-WTR) are a free by-product of the treatment of drinking water with high concentration of iron oxides and potential for arsenic sorption. This paper aims at applying Fe-WTR to a contaminated site, measuring the reduction in contaminant leaching, and discussing the design of delivery and mixing strategy for soil stabilization at field scale and present a cost-effective method of soil mixing by common contractor machinery. Soil contaminated by As, Cr, and Cu at an abandoned wood impregnation site was amended with 0.22% (dw) Fe-WTR. To evaluate the full scale amendment a 100 m2 test site and a control site (without amendment) were monitored for 14 months. Also soil analysis of Fe to evaluate the degree of soil and Fe-WTR mixing was done. Stabilization with Fe-WTR had a significant effect on leachable contaminants, reducing pore water As by 93%, Cu by 91% and Cr by 95% in the upper samplers. Dosage and mixing of Fe-WTR in the soil proved to be difficult in the deeper part of the field, and pore water concentrations of arsenic was generally higher. Despite water logged conditions no increase in dissolved iron or arsenic was observed in the amended soil. Our field scale amendment of contaminated soil was overall successful in decreasing leaching of As, Cr and Cu. With minor improvements in the mixing and delivery strategy, this stabilization method is suggested for use in cases, where leaching of Cu, Cr and As constitutes a risk for groundwater and freshwater.  相似文献   
100.
<欧洲水框架指令>(WFD)要求确定所有地表水的参考条件,即原始条件.鉴于丹麦沿岸水域的目前状态不能被称为是原始的,因此,必须通过分析历史资料或利用模型来评价参考条件.以兰讷斯峡湾为例,本文的目的是①论证通过历史资料和模拟评价参考条件的可能性和限制因素;②论证生态条件是如何随着富营养化而改变的.来自兰讷斯峡湾的充分历史资料使我们能够评价与底栖大型植物和底栖动物有关的参考条件.具有不同复杂性的模型使我们能够评价营养物质、叶绿素α、透明度板深度以及大叶藻等的参考条件.我们断定,模型是评价参考条件的有益补充,尽管它们目前由于缺乏富营养化和物种组成之间的定量联系而受到限制.  相似文献   
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