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991.
This article is a series of representative case studies of Department of Defense hazardous waste minimization. Each Military Department and the Defense Logistics Agency describe actual accomplishments. Areas covered range from production line modification to product specification change. These efforts are part of a Department of Defense plan composed of individual programs executed independently by each military service and defense agency.

Part VII of the hazardous waste minimization series appears in two separate installments: the first installment, Part VII (A), dealt with Department of Defense waste minimization efforts in vehicle repair operations, explosives manufacturing, and abrasive blasting processes; Part VII (B) covers shipboard mercury wastes, industrial chemical control, solvent reclamation, and hazardous property sales efforts.  相似文献   
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The European Economic Community Council Directive 80/779/EEC1 describes air quality limit values and guide values for sulfur dioxide and suspended particulates. However, article 10, paragraph 1 does not define well enough the reference method required, amongst others, for the gravimetric measurement of suspended particulates. It is explicity stated in article 10, paragraph 5 of the directive, that “the commission shall, in selected locations in the member states and in cooperation with the latter, carry out studies on the sampling…of suspended particulates. These studies shall be designed in particular to promote the harmonization of methods of sampling and analysis of these pollutants.” Therefore, in a joint research program the Umweltbundesamt (grant #104 02263), the commission of European Communities (grant #84-B-6642-11-017-11-N) and the U.S. EPA (grant #2-43211-3580) funded the development of a reference dust sampler by the Fraunhofer-lnstitute of Toxicology and Aerosol Research (FhITA, in Hannover, Federal Republic of Germany) in order: ? to study the particle size distribution of ambient air aerosol at a number of selected sites;

? to compare the results obtained with the reference dust sampler with those of particle samplers operated in Europe and the United States;

? to verify the applicability of wind tunnel results to sampling behaviour in the free atmosphere.

  相似文献   
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996.
Abstract:  World chocolate demand is expected to more than double by 2050. Decisions about how to meet this challenge will have profound effects on tropical rainforests and wild species in cocoa-producing countries. Cocoa, "the chocolate tree," is traditionally produced under a diverse and dense canopy of shade trees that provide habitat for a high diversity of organisms. The current trend to reduce or eliminate shade cover raises concerns about the potential loss of biodiversity. Nevertheless, few studies have assessed the ecological consequences and economic trade-offs under different management options in cocoa plantations. Here we describe the relationships between ant ecology (species richness, community composition, and abundance) and vegetation structure, ecosystem functions, and economic profitability under different land-use management systems in 17 traditional cocoa forest gardens in southern Cameroon. We calculated an index of profitability, based on the net annual income per hectare. We found significant differences associated with the different land-use management systems for species richness and abundance of ants and species richness and density of trees. Ant species richness was significantly higher in floristically and structurally diverse, low-intensity, old cocoa systems than in intensive young systems. Ant species richness was significantly related to tree species richness and density. We found no clear relationship between profitability and biodiversity. Nevertheless, we suggest that improving the income and livelihood of smallholder cocoa farmers will require economic incentives to discourage further intensification and ecologically detrimental loss of shade cover. Certification programs for shade-grown cocoa may provide socioeconomic incentives to slow intensification.  相似文献   
997.
The interactions between potassium and sulfur-containing species are unique, yet important, phenomena for a coal-fired magnetohydrodynamics (MHD) system. An in-depth understanding of such phenomena will help in the future design of MHD systems. This paper deals with the modeling of potassium and sulfur interactions in DOE's Coal-Fired Flow Facility (CFFF), located in Tullahoma, Tennessee.  相似文献   
998.
Gray, Stephen T., Jeffrey J. Lukas, and Connie A. Woodhouse, 2011. Millennial‐Length Records of Streamflow From Three Major Upper Colorado River Tributaries. Journal of the American Water Resources Association (JAWRA) 47(4):702‐712. DOI: 10.1111/j.1752‐1688.2011.00535.x Abstract: Drought, climate change, and shifting consumptive use are prompting a widespread reassessment of water availability in the Upper Colorado River basin. Here, we present millennial‐length records of water year (October‐September) streamflow for key Upper Colorado tributaries: the White, Yampa, and Little Snake Rivers. Based on tree rings, these records represent the first paleohydrological reconstructions from these subbasins to overlap with a series of Medieval droughts (∼ad 800 to 1300). The reconstructions show marked interannual variability imbedded in nonstationary behavior over decadal to multidecadal time scales. These reconstructions suggest that, even in a millennial context, gaged flows from a handful of years (e.g., 1977 and 2002) were extremely dry. However, droughts of much greater duration and magnitude than any in the instrumental record were regular features prior to 1900. Likewise these reconstructions point to the unusual wetness of the gage period, and the potential for recent observations to paint an overly optimistic picture of regional water supplies. The future of the Upper Colorado River will be determined by a combination of inherent hydroclimatic variability and a broad range of human‐induced changes. It is then essential that regional water managers, water users, and policy makers alike consider a broader range of hydroclimatic scenarios than is offered by the gage record alone.  相似文献   
999.
This study examines the composition and activity of the planktonic community during the polar night in the high Arctic Kongsfjord, Svalbard. Our results are the first published evidence of bioluminescence among zooplankton during the Arctic polar night. The observations were collected by a bathyphotometer detecting bioluminescence, integrated into an autonomous underwater vehicle, to determine the concentration and intensity of bioluminescent flashes as a function of time of day and depth. To further understand community dynamics and composition, plankton nets were used to collect organisms passing through the bathyphotometer along with traditional vertical net tows. Additionally, using a moored bathyphotometer closed to the sampling site, the bioluminescence potential itself was shown not to have a diurnal or circadian rhythm. Rather, our results provide evidence for a diel vertical migration of bioluminescent zooplankton that does not correspond to any externally detectable changes in illumination.  相似文献   
1000.
The numerical computer models that simulate municipal solid waste (MSW) bioreactor landfills have mainly two components – a biodegradation process module and a multi-phase flow module. The biodegradation model describes the chemical and microbiological processes. The models available to date include predefined solid waste biodegradation reactions and participating species. Some of these models allow changing the basic composition of solid waste. In a bioreactor landfill several processes like anaerobic and aerobic solids biodegradation, nitrogen and sulfate related processes, precipitation and dissolution of metals, and adsorption and gasification of various anthropogenic organic compounds occur simultaneously. These processes may involve reactions of several species and the available biochemical models for solid waste biodegradation do not provide users with the flexibility to simulate these processes by choice. This paper presents the development of a generalized biochemical process model BIOKEMOD-3P which can accommodate a large number of species and process reactions. This model is able to simulate bioreactor landfill operation in a completely mixed condition, when coupled with a multi-phase model it will be able to simulate a full-scale bioreactor landfill. This generalized biochemical model can simulate laboratory and pilot-scale operations in order to determine biochemical parameters important for simulation of full-scale operations.  相似文献   
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