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341.
David J. Schaeffer Konanur G. Janardan Harold W. Kerster 《Environment international》1980,4(2):157-162
The “filter model” has been developed to explain the biologic effects of radiation and chemicals. We have examined nearly 300 sets of dose response data, of which 50 are presented here. Responses (induced by radiation and chemicals) which have been examined include in vitro survival studies on animal and plant tissues, induction of cellular aberrations and time to tumor or death. Similar data from in vivo studies has also been examined. All of the data appear to fit the model R = a lnD + b(lnD)2 + c, where R is the response, a and b are parameters fitted by regression to a particular set of data, and c is the response at zero (or lowest) dose. By writing this model in exponential form, it can be seen that the response R results from multistage filtering (by net amounts a and b) of the initial dose, D. The threshold is obtained from this model as the point, , at which the second derivative becomes zero. This is given by when a and b are oppositelt signed. 相似文献
342.
Resource estimates alone will not give advance warning of encroaching production difficulties. An analysis of the general stages in the evolution of petroleum production and discovery and of industry statistics provides an estimate of when the stage characterised by increasing production in the market economy countries outside the United States and Canada will end. The analysis indicates that the year of maximum production will be in the 1990s. Economic growth aggravates the difficulties accompanying the production decline by advancing the date of peak production and by increasing the adjustments that must be made as oil production declines. Des prévisions de ressources à elles seules ne constituent pas des signes précurseurs de difficultés croissantes de production. Une analyse des étapes générales marquant l'evolution de la découverte et de la production du pétrole ainsi que des statistiques industrielles nous permet de prévoir l'époque à laquelle prendra fin la phase de production accrue dans les pays à économie de marché en dehors des Etats-Unis et du Canada. Cette analyse révèle que l'année de production maximale se situera dans les années 90. La croissance économique accentue les difficultés qui accompagnent le déclin de la production de pétrole en avancant la date à laquelle cell-ci atteindra son plafond et en augmentant le nombre d'ajustements qui s'avèrent nécessaires au fur et à mesure qu'elle baisse. Las evaluaciones de recursos no dan por si solas un aviso anticipado de las dificultades de producción. Un análisis de las etapas principales en la evolución del descubrimiento y producción de petróleo y de las estadísticas industriales provee un estimado de cuando va a terminar la etapa caracterizada por un crecimiento de producción en los paises de economias de mercado otros que Estados Unidos y Canada. El análisis indica que el año de producción máxima se hallará en la década del 90. El crecimiento económico agrava las dificultades debidas a la declinación de la producción al adelantar la fecha de máxima producción (pico) y al aumentar los ajustes que deven hacerse cuando la producción de petróleos disminuye. 相似文献
343.
344.
John H Mutti J.David Richardson 《Journal of Environmental Economics and Management》1977,4(2):135-152
This paper demonstrates empirically the gain from adopting more general equilibrium approaches in projecting the effects on domestic output and international trade of environmental controls. The suggested models include a partial equilibrium case where all industries are treated independently, an intermediate case incorporating effects in supplying industries, and general equilibrium formulations based on alternative macroeconomic conditions. U. S. data is used to evaluate these models. Under both pollutor pays and subsidy financing schemes, moving from the simplest case to the intermediate model results in quite different industry projections. Including macroeconomic factors appears particularly important in the classical setting. 相似文献
345.
346.
This article examines the role of economic development agencies in strengthening the environmental performance of industry within rapidly industrialising East Asian economies. Three case-study examples are considered, namely, the role of the Industrial Development Board in reducing industrial pollution in Taiwan, pollution control in the palm oil industry in Malaysia, and the role of the Economic Development Board in influencing environmental performance of industry in Singapore. The concept of embedded autonomy is developed to consider the ways in which agencies of economic development can work with firms and industries while simultaneously remaining autonomous from these firms with respect to setting and enforcing performance standards. The three cases suggest that a form of policy integration that more directly integrates economic and environmental goals within agencies of economic development may be feasible, but only where there exists a strong autonomous government bureaucracy and where there is strong societal commitment to improving the environmental performance of industry. 相似文献
347.
There is a growing recognition that knowledge of indigenous communities, based on accumulated observations and experience over time, is significant for sustainable environmental management in collaboration with modern scientific knowledge. A number of innovative policy initiatives are currently being implemented in New Zealand to enable indigenous Maori tribes and sub-tribes to rehabilitate and manage their local fisheries in accordance with customary values and practices. These policies are an important milestone from an historical perspective as they are meant to recognise and empower the role of Maori as Treaty partners. The fisheries management regime in New Zealand now provides for Maori representation at the local level within a co-management framework that enables local Maori communities to exercise their customary rights. These institutional arrangements have been crafted to facilitate Maori input, based on customary values and practices, to complement modern Western management practices for sustainable harvesting of marine resources. Nevertheless, the degree to which these initiatives constitute an adequate response to Maori Treaty aspirations is debatable. A major constraint in this respect is that the government is compelled to recognise the needs of other, economically and politically more dominant, non-Maori user-groups in allocating and managing access to fishery resources and the marine environment. 相似文献
348.
Jonathan B. Butcher 《Journal of the American Water Resources Association》2003,39(6):1521-1528
ABSTRACT: Most watershed water quality simulation models require the user to specify pollutant buildup and washoff rate parameters for pollutants, by land use. Buildup and washoff rates are difficult to measure directly, and only limited guidance and few observed data are available from the literature. Many studies, however, report storm event mean concentrations (EMCs). These EMCs must arise as a result of the buildup and washoff processes, but typically represent the net contribution from a variety of pervious and impervious surfaces. This paper explores the relationship between EMCs and buildup/washoff parameters. An assumption of the mathematical form of the buildup/washoff relationship gives an algebraic expression for the EMC consistent with model assumptions. This yields techniques to separate observed EMCs into contributions from different land uses and from pervious and impervious surfaces. Given this relationship, numerical optimization may be used to estimate site specific values of buildup and washoff parameters from observed storm EMCs for use in modeling. Use of this approach helps ensure that model parameters are consistent with observed data, providing a rational starting point for final model calibration. Several site examples demonstrate use of the method. 相似文献
349.
350.
S. L. Holmberg T. Claesson M. Abul-Milh B. -M. Steenari 《Resources, Conservation and Recycling》2003,38(4):3071
At the district heating plant of Kalmar, Sweden an on-line unit for production of granulated wood ash for nutrient recycling on forest soils is being applied. Currently, the granules are dried by hot air from an oil-fired burner. The objective of this work was to investigate how drying by flue gas affects the hardening of granules, or impacts their chemical composition and properties. Ninety-six granule samples were treated by flue gas from natural gas combustion in a laboratory pilot scale flue gas generator. CO2, CO, O2, C3H8 and NO concentrations were varied during the experiment. Additionally, some samples were treated by flue gas from combustion of sawdust at the heating plant in Kalmar. Drying by flue gases did not affect the chemical composition of granules, but minor effects were seen in their mineralogy. The carbonate content was slightly higher in granules treated with flue gas from natural gas combustion compared to the granules dried by hot air only, when measured by wet chemical methods. Results from XRD analysis imply that the calcite content is higher and the portlandite and arcanite content slightly less in granules treated with flue gas from sawdust combustion compared to the granules dried by hot air only. The results from this investigation showed no negative effects on ash granule composition or physical structure by the use of a flue as a drying medium. 相似文献