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The duct injection retrofit process for flue gas cleanup of sulfur dioxide emissions has been demonstrated at several sites in the United States through a series of U.S. Department of Energy research projects. As a subcontractor on one of the projects, the University of North Dakota Energy & Environmental Research Center performed a comprehensive characterization of four residues from three demonstration sites. The characterization task objective was to facilitate understanding of materials handling and to identify potential disposal and utilization options for these high-volume coal utilization solid residues. Characterization included evaluation of the physical and engineering properties, chemical composition, mineralogy, and leaching potential. Chemical characterization results provided interesting and valuable information from the standpoint of the bulk chemistry and phase assemblages, as well as potential environmental issues associated with the use or disposal of these materials. Results of the chemical and mineralogical characterizations indicate that duct injection residues will be suitable for specific utilization applications and that disposal of these residues should be similar to many conventional coal combustion residues. Significant mineralogical phase changes were noted in long-term leaching experiments.  相似文献   
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Protecting eggs from predators is common practice in sea turtle conservation, but routine protection of hatchlings is not. Of 42 loggerhead hatchlings observed emerging from 10 nests on undeveloped Onslow Beach, North Carolina, 24 % were preyed on by ghost crabs. In experimental trials, ghost crabs similarly threatened and captured neonate freshwater sliders, supporting their substitution as proxy for threatened and endangered sea turtle hatchlings in field experiments testing density dependence. Exploiting natural long-shore variation in ghost crab density, we show that a 2.6-fold higher ghost crab density resulted in 5 times more nocturnal threat encounters with sliders and 3.4 times more slider captures. Sliders released in simulated group emergences experienced lower per capita capture risk by ghost crabs than solitary sliders, implying predator dilution. Non-independence of egg and hatchling depredation motivates consideration of merging sea turtle egg and hatchling stages when modeling and managing food web interactions.  相似文献   
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Resource planning and management in British Columbia, Canada, has been steadily moving towards more active public participation. While government agencies have long been required to consult the general public during the course of land or resource use planning, the 1990s brought in a period of more intense public involvement. In terms of resource planning, this led to the creation of several new planning processes. Given that there is now considerable experience with the Commission on Resources and Environment (CORE) and the Land and Resource Management Plan (LRMP) processes, it is time for an appraisal. In particular, the paper examines the public's perceptions of these processes with respect to 'what works well' and 'what needs improvement'. The results highlight a number of areas to which process designers and managers should direct attention. There are three key items of note. First, there are generally low levels of awareness by respondents of public consultation processes in their community. Second, there is a need for access to timely, relevant and readable information throughout the course of the process in order to keep participants and the public as up-to-date as possible. Finally, there must be greater clarity about the process itself, including mandates, participants and decision-making powers.  相似文献   
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The biophysical features of small islands (SI) distinguish them from other territories; isolation, small size and several anthropogenic pressures reduce the resilience of ecosystems and increase their vulnerability to global changes. Many SI have a shortage of infrastructures, institutions and technical/financial resources that hinder planning and require different integrated solutions. In Portugal, the National Ecological Reserve (NER) is legally binding for spatial planning instruments. It aims to defend natural values and areas of ecological value, or sensibility, or susceptible to natural hazards. However, the criteria for the design of NER are strictly set for mainland territory, not taking into account specific features of small islands. A case study of the Azores Archipelago is used to demonstrate that spatial planning instruments should be adapted to island contexts. Such adaptation will increase the effectiveness of their implementation in relation to the protection of natural resources, stability of biophysical structures and prevention of natural hazards. Observing the main differences between mainland and the Azores Archipelago it is possible to define a methodological transposition of the NER aims and goals into an island context. This approach is an answer to the constraints in effective adaptation of spatial planning instruments for islands.  相似文献   
116.
Smelter waste deposits pose an environmental threat worldwide. Biosolids are potentialy useful in reclamation of such sites. Biological aspects of revegetation of Zn and Pb smelter wastelands using biosolids are discussed in this report. The goal of the studies was to assess to what extent biosolid treatment would support ecosystem functioning as measured by biological indicators such as enzyme activities of revegetated metal waste or plant growth. Another crucial aspect was related to the assessment of metal transfer to the ecosystem which could affect the health of local fauna and also create a food chain risk. A field experiment was conducted on a smelter waste deposit in Piekary Slaskie, Silesia, Poland, with two separate fields - established on wastes from the Welz and Doerschel smelting processes. The tested methods allowed revegetation of the fields - application of municipal biosolid at the rate 300 dry t ha(-1) combined with the incorporation of commercial lime in a mixed oxide and carbonate form at the rate of 1.5 and 30 t for Welz waste or use of a 30 cm by-product lime cap followed by incorporation of biosolid at a rate of 300 t ha(-1) for the more acidic Doerschel waste. Studies on biological activities demonstrated that the reclamation methods used are an effective way to establish new, fully-functioning ecosystems that support plant growth. They also provided strong evidence that forage crops grown on Zn, Cd and Pb contaminated sites reclaimed using lime and biosolids do not pose identified risk for wildlife and food safety.  相似文献   
117.
An insect parasitoid carrying an ochratoxin producing fungus   总被引:2,自引:0,他引:2  
The insect parasitoid Prorops nasuta has been introduced from Africa to many coffee-producing countries in an attempt to control the coffee berry borer. In this paper, we report on the sequencing of the ITS LSU-rDNA and beta-tubulin loci used to identify a fungus isolated from the cuticle of a P. nasuta that emerged from coffee berries infected with the coffee berry borer. The sequences were compared with deposits in GenBank and the fungus was identified as Aspergillus westerdijkiae. The fungus tested positive for ochratoxin A production, with varying levels depending on the media in which it was grown. These results raise the possibility that an insect parasitoid might be disseminating an ochratoxin-producing fungus in coffee plantations.  相似文献   
118.
The objectives of this paper are to contrast the relative variability of replicate laboratory measurements of selected chemical components of fine particulate matter (PM) with total variability from collocated measurements and to compare the magnitudes of the uncertainties determined from collocated sampler data with those currently being provided to U.S. Environmental Protection Agency (EPA)'s Air Quality System (AQS) database by RTI International (RTI). Pointwise uncertainty values are needed for modeling and data analysis and should include all the random errors affecting each data point. Total uncertainty can be decomposed into two primary components: analytical measurement uncertainty and sampling uncertainty. Analytical measurement uncertainties are relatively easy to calculate from routine quality control (QC) data. Sampling uncertainties, on the other hand, are comparatively difficult to measure. In this paper, the authors describe data from collocated samplers to provide a snapshot of whole-system uncertainty for several important chemical species. The components of uncertainty were evaluated for key species from each of the analytical methods employed by the PM2.5 Speciation Trends Network (STN) program: gravimetry, ion chromatography (IC), X-ray fluorescence (XRF), and thermal-optical analysis for organic carbon and elemental carbon. The results show that the laboratory measurement uncertainties are typically very small compared with uncertainties calculated from the differences between samples collected from collocated samplers. These differences are attributable to the "field" components uncertainty, which may include contamination and/or losses during shipping, handling, and sampling, as well as other distortions of the concentration level due to flow and sample volume variations. Uncertainties calculated from the collocation results were found to be generally similar to the uncertainties currently being loaded into EPA's AQS system, with some exceptions described below.  相似文献   
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