Relation of Lake Acidification and Recovery to Fish,Common Loon and Common Merganser Occurrence in Algoma Lakes

Models are needed that predict both spatial and temporal improvements to ecosystems following reductions of acidifying emissions that produce `acid rain'. Logistic regression models were developed for the occurrence of fish and two fish-eatingbirds, common loons (Gavia immer) and common mergansers(Mergus merganser), using monitoring data collected onlakes across Ontario. These models were applied in the Algomaregion, including the Turkey Lakes Watershed (TLW). Using theWaterfowl Acidification Response Modeling System (WARMS), severalSO₂ emission reduction scenarios were simulated, i.e. thosecontributing to measured 1982–1986 sulphate deposition levels, 1994levels (corresponding to full implementation of Canadian SO₂emission reductions as stipulated in the 1991 Canada/U.S. AirQuality Agreement), 2010 levels (1994 plus full U.S. reductions),and both a 50% and a 75% further reduction beyond 2010 levels. Some habitat improvements in Algoma were predicted under the 2010scenario for all biota, but substantial increases in habitatquality, especially for mergansers, would occur only under further reductions. The TLW showed little change in chemistry orbiota, while lakes near the Montreal River were predicted toimprove substantially.     

Studies on the pyrolysis behavior of gasification and melting systems for municipal solid waste

 It is important to investigate the pyrolysis processes of municipal solid waste (MSW) in the same way as for any mixture comprised of multiple substances. In this article, a two-reaction model for a variety of MSW mixtures is proposed to predict mass changes due to pyrolysis. In order to formulate the model based on pyrolysis kinetics, we conducted experiments to determine the kinetic model parameters. By thermal analysis of the typical components of MSW, mass changes attributable to the pyrolysis reaction were found at about 350°C for paper, 400°–500°C for plastics, and 200°–400°C for garbage (dry condition). Activation energies were obtained by the Ozawa method based on the mass changes in pyrolysis. Thus, the pyrolysis behavior is formulated as a function of temperature. Then the pyrolysis mass change of the mixture can be predicted by using a weighted sum of the individual components. The model proved useful in experiments with real waste (refuse-derived fuels). Furthermore, the weight yields (pyrolysis gas, tars, solid residues) of the mixture can be calculated by their additive property after measuring the mass balance of each component. Received: May 11, 2001 / Accepted: November 16, 2001     

RESERVOIR WATER LEVEL IMPACTS ON RECREATION,PROPERTY, AND NONUSER VALUES1

ABSTRACT: Wise interbasin management of Southeastern U.S. water resources is important for future development. Alabama‐Coosa‐Tallapoosa and Apalachicola‐Flint‐Chattahoochee River basins' water usage has evolved from power generation to multiple uses. Recreation and housing have become increasingly valuable components. Changing use patterns imply changing resource values. This study focused on six Alabama reservoirs, using contingent valuation questions in on‐site, telephone, and mail surveys to estimate impacts on lakefront property values, recreational expenditures, and preservation values for scenarios of permanent changes to reservoir water quantity. As summer full‐pool duration decreased, lakefront property value decreased, and as duration increased, property values increased, but at a lesser rate. Similar findings occurred for winter draw down alternatives. Permanent one‐foot reductions in summer full‐pool water levels resulted in a 4 to 15 percent decrease in lakefront property values. Recreational expenditures decreased 4 to 30 percent for each one‐foot lowering of reservoir water levels. Current nonusers of the six reservoirs showed strong preferences for protecting study reservoirs with willingness to pay values of 47 per household or approximately 29 million for the entire six‐reservoir watershed basin area. Resource management based on historic use patterns may be inappropriate and more frequent and comprehensive valuation of reservoir resources is needed.     

论环境资源产业化

由于环境问题的复杂性与弥散性,直接界定其产权并不能真正解决环境质量问题。本文提出了环境资源产业化这种间接解决方法,并对环境资源产业化的具体内容及外部保障政策作了阐述。     

ASSESSMENT OF HYDRAULIC PROPERTIES IN AN UNCONFINED ALLUVIAL AQUIFER NEAR GRAND ISLAND,NEBRASKA1

ABSTRACT: A method is presented to analyze time-drawdown data from one or more observation wells for the calculation of four hydraulic parameters for unconfined aquifers: vertical hydraulic conductivity, horizontal hydraulic conductivity, storage coefficient, and specific yield. The hydraulic parameter results are further analyzed for reliability and the possible ranges of the actual parameter values. After verification using a theoretical example, the method was used to analyze pumping test data from 22 observation wells in an unconfined alluvial aquifer near Grand Island, Nebraska. Results indicate that this method can be used to efficiently calculate the four hydraulic parameters in this type of aquifer. The method can also identify the impact of measurement errors on the parameter estimates, and provide ranges of the actual parameter values. The parameter values calculated using this method were compared to those determined using other theories. It is found that this method is very useful for calculating the hydraulic properties from pumping test data and for analyzing the parameter reliability.     

Thermal based functional evaluation of urban park vegetation

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生产工艺参数对高碳钢线材力学性能的影响

用正交试验的方法研究了不同工艺参数对高碳钢力学性能的影响.分析了82MnA钢线材的生产工艺参数.     

从理论到实践的美国排污交易

阐述了排污交易产生的背景，排污权与排放许可证的概念，ＴＤＰ的理论研究和实践应用，排污交易政策在美国的发展等。美国的排污交易政策由补偿政策、气泡政策、净得政策和排污银行４项组成，以美国酸雨计划为例说明了排污交易的巨大环境经济效益，并给出了建议。     

超临界水的物理化学性质及意义

水的许多性质在其临界区域随温度、压力的升高有着异常的变化行为，这种行为不仅控制着热液体系中的质量和热量输运过程，使得流体和对流热通量以及水溶液溶质的大多数标准偏摩尔性质在水的临界点附近接近正的或负的无穷大，而且也影响着体系中的化学过程。超临界水溶液流体与室温下的电解质溶液在许多方面有很大的差别，这些差别对水如何溶解矿物及迁移金属和配合物具有深刻的影响。     

"共同体"范围扩展与环境权利体系--可持续发展研究

探讨了深入研究可持续发展的两个基本问题：主体范围问题，环境权利体系问题。与“人类中心论”认为道德只调整人与人之间关系不同，“生态中心论”认为起码应把受人类社会影响最大的一部分自然物与人的关系作为环境道德调整的直接客体，人类与这部分自然物构成社会的扩展体－“共同体”，环境权利体系则试图把环境权利内容扩展至生物多样性，赋予生物物种生存权利，主体范围和权利内容扩展的目的是确立可持续发展的权利体系。