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771.
Plant species, forming important components of Arctic food chains and of interest from a monitoring perspective, were studied at 36 plots representing flood plain and terrace landscapes of the Yenisey River and Estuary from its upper delta to the gulf. (137)Cs contamination densities at the plots varied from 0.35kBq/m(2) (central delta, sandy riverside plot) to 88kBq/m(2) (the upper delta plot) indicating both global and regional sources of anthropogenic pollution. Cs-137 levels in plants were within the range expected from global fallout inputs and varied from 31 to 140Bq/kg d.w. increasing in dominant groups in the order: grasses相似文献   
772.
Recent developments regarding environmental impact assessment methodologies for radioactivity have precipitated the need for information on levels of naturally occurring radionuclides within and transfer to wild flora and fauna. The objectives of this study were therefore to determine activity concentrations of the main dose forming radionuclides 210Po and 210Pb in biota from terrestrial ecosystems thus providing insight into the behaviour of these radioisotopes. Samples of soil, plants and animals were collected at Dovrefjell, Central Norway and Olkiluoto, Finland. Soil profiles from Dovrefjell exhibited an approximately exponential fall in 210Pb activity concentrations from elevated levels in humus/surface soils to “supported” levels at depth. Activity concentrations of 210Po in fauna (invertebrates, mammals, birds) ranged between 2 and 123 Bq kg−1 d.w. and in plants and lichens between 20 and 138 Bq kg−1 d.w. The results showed that soil humus is an important reservoir for 210Po and 210Pb and that fauna in close contact with this media may also exhibit elevated levels of 210Po. Concentration ratios appear to have limited applicability with regards to prediction of activity concentrations of 210Po in invertebrates and vertebrates. Biokinetic models may provide a tool to explore in a more mechanistic way the behaviour of 210Po in this system.  相似文献   
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Abstract

The characteristics of the air pattern and spray droplet trajectories from the Algonquin airblast forestry sprayer were investigated. An experiment with water and Rhodamine tracer dye was conducted in a shelterwood location to evaluate droplet deposition on Kromekote® card targets above and within a canopy of poplar saplings. Computer simulation of a free jet was used to model the airblast in order to investigate droplet trajectories. Measured deposits indicated that the effective swath width is 14 m from the blower outlet. Mean simulated droplet trajectory data were in good agreement with the droplet density data observed in the field. Both sets of results predicted a very low level of spray deposition beyond 14 m.  相似文献   
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The body of information presented in this paper is directed to administrators of smaller authorities—defined, arbitrarily, as those with small staff and not embracing large metropolitan areas. As their activities increase, viable programs are likely to produce prodigious quantities of data, necessitating the use of modern computers for most efficient analysis.

Remote links with high-speed time sharing computers provide a means for smaller authorities to satisfy this need. The capabilities of a large computer can be brought into the local office to handle (a) administrative and enforcement problems, (b) technical data analysis, and (c) instructional needs.

A data handling system being developed for use by the Northwest Air Pollution Authority is described, together with an examination of its potential utility to the Authority as its activities increase.  相似文献   
778.
Coconut trees growing on atolls of the Bikini Islands are on the margin of K deficiency because the concentration of exchangeable K in coral soil is very low, ranging from only 20 to 80 mg kg−1. When provided with additional K, coconut trees absorb large quantities of K and this uptake of K significantly alters the patterns of distribution of 137Cs within the plant. Following a single K fertilization event, mean total K in trunks of K-treated trees is 5.6 times greater than in trunks of control trees. In contrast, 137Cs concentration in trunks of K-treated and control trees is statistically the same while 137Cs is significantly lower in edible fruits of K-treated trees. Within one year after fertilization (one rainy season), K concentration in soil is back to naturally low concentrations. However, the tissue concentrations of K in treated trees stays very high internally in the trees for years while 137Cs concentration in treated trees remains very low in all tree compartments except for the trunk. Potassium fertilization did not change soil Cs availability.  相似文献   
779.
Territoriality is an emerging concept of importance in organizations. Unfortunately, there does not exist currently a valid measure of territoriality with which to conduct research on territoriality in organizations. I developed a theoretically driven four-factor measure of territoriality. Six hundred and sixty-three people working in office settings completed an online survey about their territorial behaviors. Using confirmatory factor analysis I found that the four-factor structure had acceptable fit. I also found preliminary evidence of construct validity. Collectively, the results support the validity of the measure, thus providing an instrument for studying territoriality in organizations. I then discuss specific implications of this measure for both research and practise.  相似文献   
780.
The perspectives of residents are brought together in this assembly of statements concerning the management of hexachlorobenzene waste in Botany, a southeastern suburb of Sydney. The paper indicates how residents have responded as participants in public participation exercises, and the contribution made by lay experts in the search for a negotiated solution to the problems of legacy wastes. Resident comments on the role of independent scientific experts, on legal liability, and on the State Government sponsored Commission of Inquiry, indicate the deficit of resources faced by the local community. The paper provides insights into the status of citizen knowledge in environmental controversies and the pitfalls of participatory processes.  相似文献   
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