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741.
Miskewitz R. J. Hires R. I. Su T. L. Korfiatis G. P. Sidhoum M. 《Water, Air, & Soil Pollution: Focus》2004,4(4-5):45-54
A 50 ha known contaminated site in Bayonne, New Jersey, U.S.A. is permitted to receive up to 3 × 106 m3 of sediment dredged from navigation channels in the New York/New Jersey Harbor. Much of the sediment is expected to contain low to moderate concentrations of industrial and agricultural chemicals, including Polychlorinated Biphenyls (PCBs). The dredged material brought to the site is stabilized with cement and then placed as a capping and grading layer. The flux of PCBs from drying stabilized dredged material has been estimated from measurements of PCB air concentrations at two heights above the ground along with micrometeorological observations. A statistically significant gradient in PCB concentrations has been consistently measured in the first 3 m above the ground. Observed PCB fluxes were highest over freshly placed stabilized dredged sediment and decreased as it cured. The highest flux observed in this study was 7214 ng/m2/h, but during subsequent sampling intervals at the same site, the flux estimates decreased by an order of magnitude over a 5-day interval. 相似文献
742.
随着我国油田相继进入开发后期,传统的滤料及设备过滤精度已不能满足注水的要求。因此,研究并开发了具有一定抗油污能力的新型过滤材料,设计了新型的超精细过滤器系列产品。对滤料进行的室内实验结果表明,在开始过滤的近10h内,过滤后的水中含油量基本上满足注水的水质要求。在开始过滤的近20h内,滤层的水头损失随时间的变化较为平缓;随着过滤时间的延长,水头损失变化加剧。从现场实验可以看出,所设计的过滤器有良好的过滤性能和抗冲击能力。新型过滤材料的研究成功解决了油田含油污水精细过滤的问题,新型过滤器也是含油污水超精细过滤的理想产品。 相似文献
743.
红外光度法测定石油类和动植物油常见问题探讨 总被引:2,自引:0,他引:2
根据石油类在波数为2930cm-1、2960 cm-1、3030 cm-1全部或部分谱带处有物征吸收的原理,采用红外光度测油仪和水样絮凝富集技术测定石油类、动植物油。 相似文献
744.
745.
The Ethical Contract as a Tool in Organic Animal Husbandry 总被引:1,自引:3,他引:1
Vonne Lund Raymond Anthony Helena Röcklinsberg 《Journal of Agricultural and Environmental Ethics》2004,17(1):23-49
This article explores what an ethicfor organic animal husbandry might look like,departing from the assumption that organicfarming is substantially based in ecocentricethics. We argue that farm animals arenecessary functional partners in sustainableagroecosystems. This opens up additional waysto argue for their moral standing. We suggestan ethical contract to be used as acomplementary to the ecocentric framework. Weexpound the content of the contract and end bysuggesting how to apply this contract inpractice. The contract enjoins us to share thewealth created in the agroecosystem (by ourjoint contributions) by enjoining us to carefor the welfare and needs of the individualanimal, and to protect them from exploitation(just as human co-workers should not beexploited). The contract makes promoting goodanimal welfare a necessary condition forbenefiting farm animals. Animals for their partare guaranteed coverage under the contract solong as they continue to contribute to thesystem with products and services. 相似文献
746.
Forest resources play a key role and provide many basic needs to communities in developing economies. To assess the patterns of vegetation cover change, as a corollary of resource utilization, satellite imagery, ground truth data, and image processing techniques can be useful. This article is concerned with identifying change in major vegetation types in East Timor between 1989 and 1999, using Landsat Thematic Mapper data. The results highlight a significant level of deforestation and decline in foliage cover. All major vegetation cover types declined from 1989 to 1999, and there was a sizeable increase in degraded woodlands. This decline has had considerable impact on the livelihoods of rural and urban communities. Causes for these changes include: economic exploitation of abundant resources; and implications of transmigration policies implemented during Indonesian rule, resulting in increased competition for land and woodland resources. As the new nation of Timor‐Leste establishes itself, it must consider its current stock and distribution of natural capital to ensure that development efforts are geared towards sustainable outcomes. Without the knowledge of historical patterns of resource consumption, development efforts may, unwittingly, lead to continuing decline in forest resources. 相似文献
747.
Aida Mendez Gary R. Sands Berangere Basin Chang‐Xing Jin Paul J. Wotzka 《Journal of the American Water Resources Association》2004,40(2):385-400
ABSTRACT: Surface and subsurface drainage make crop production economically viable in much of southern Minnesota because drainage allows timely field operations and protects field crops from extended periods of flooded soil conditions. However, subsurface drainage has been shown to increase nitrate/nitrogen losses to receiving waters. When engaging in drainage activities, farmers are increasingly being asked to consider, apart from the economic profit, the environmental impact of drainage. The Agricultural Drainage and Pesticide Transport model (ADAPT) was used in this study to evaluate the impact of subsurface drainage design on the soil water balance over a two‐year period during which observed drainage discharge data were available. Twelve modeling scenarios incorporated four drainage coefficients (DC), 0.64 cm/d, 0.95 cm/d, 1.27 cm/d, and 1.91 cm/d, and three drain depths, 0.84 m, 1.15 m, and 1.45 m. The baseline condition corresponded to the drainage system specifications at the field site: a drain depth and spacing of 1.45 m and 28 m, respectively (DC of 0.64 cm/d). The results of the two‐year simulation suggested that for a given drainage coefficient, soils with the shallower drains (but equal DC) generally have less subsurface drainage and can produce more runoff (but reduced total discharge) and evapotranspiration. The results also suggested that it may be possible to design for both water/nitrate/nitrogen reduction and crop water needs. 相似文献
748.
749.
Darren C. Treadway Wayne A. Hochwarter Charles J. Kacmar Gerald R. Ferris 《组织行为杂志》2005,26(3):229-245
The current study used Mintzberg's (1983) conceptualization of political will and political skill to evaluate the predictors and consequences of political behavior at work. As elements of political will, we hypothesized that need for achievement and intrinsic motivation would predict the use of political behavior at work. Furthermore, we argued that political skill would moderate the relationship between political behavior and emotional labor. Data gathered from employees (N = 193) representing a wide array of organizations substantiated the proposed relationships. Specifically, need for achievement and intrinsic motivation were positively associated with political behavior. In turn, those opting to employ political behavior at work experienced a higher degree of emotional labor, but this relationship was found to operate differently at low and high levels of political skill. Specifically, emotional labor was a consequence of political behavior for those low in political skill, but emotional labor reactions from political behavior were neutralized for individuals high in political skill. Implications of these results, strengths and limitations, and directions for future research are discussed. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
750.