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1.
We report a series of 350 patients submitted to transabdominal chorionic villus sampling (CVS). A technique using two ultrasound-guided needles and a suction pump was used. In most cases, the procedure was performed between 9 and 13 weeks. Twenty-one pregnancies were selectively terminated; nine spontaneous abortions followed the procedure and one fetal loss after 28 weeks was recorded; 153 pregnancies are in progress and 169 delivered fetuses are alive and well. Transabdominal biopsy is a feasible and effective technique for CVS.  相似文献   
2.
Environmental assessment of supercritical water oxidation of sewage sludge   总被引:1,自引:0,他引:1  
Environmental aspects of using supercritical water oxidation (SCWO) to treat sewage sludge were studied using a life cycle assessment (LCA) methodology. The system studied is the first commercial scale SCWO plant for sewage sludge in the world, treating sludge from the municipal wastewater treatment facility in Harlingen, TX, USA. The environmental impacts were evaluated using three specific environmental attributes: global warming potential (GWP), photo-oxidant creation potential (POCP) and resource depletion; as well as two single point indicators: EPS2000 and EcoIndicator99. The LCA results show that for the described process, gas-fired preheating of the sludge is the major contributor to environmental impacts, and emissions from generating electricity for pumping and for oxygen production are also important. Overall, SCWO processing of undigested sewage sludge is an environmentally attractive technology, particularly when heat is recovered from the process. Energy-conserving measures and recovery of excess oxygen from the SCWO process should be considered for improving the sustainability potential.  相似文献   
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Total suspended particulate matter and deposition fluxes of particles were investigated in the town of Didouche Mourad which is located 13 km north of Constantine. Samples of air particulate matter were collected at one site located in the heart of the town and situated 3 km north of a cement plant. Samples were collected from 2 November 2002 to 28 April 2003 every 3 days using a high volume air sampler. Sampling intervals were 24 h in all cases. During the same period, samples of dust fallout were collected at the same site. Samples were collected at 30-day intervals. Lead, chromium, manganese, nickel, copper, cobalt and cadmium deposition fluxes were measured and both the soluble and insoluble fractions were determined. Furthermore, the information gathered by this study was correlated with the corresponding hourly weather data provided by a weather station installed at the study station. The possible sources for dust and trace metals were analyzed by comparing average contributions of wind aspects to the concentrations and depositions of mass and chemical species with the average frequencies of wind direction. The mean concentration was 300 μg/m3. The average dust deposition rate through the period of study was 221 mg/(m2.day). Results indicate that anthropogenic sources contribute greatly to trace elements. An exposure assessment to the heavy metals taking into account the inhalation route and soil dust ingestion was carried out and allowed direct comparison of trace metal intakes via these routes.  相似文献   
5.
ABSTRACT: Two case studies highlighting the institutional arrangements and decision-making processes used to attempt to allocate water on large scale river systems in two countries are presented. In both cases the implementation of river plans has been blocked by conflicts between those who wish to use water for irrigation, hydropower, or municipal purposes and those who wish to maintain instream flows for fish and wildlife. To date conflict has blocked the implementation of a large hydropower scheme on the Danube River, downstream from Vienna, Austria, and the construction of municipal and agricultural projects, as well as the relicensing of an existing hydropower facility on the Platte River in Nebraska. Analysis of the decision-making processes and institutional settings of both cases led to the identification of problem areas and development of recommendations that would support the achievement of compromise solutions for management.  相似文献   
6.
ABSTRACT .Many growing municipalities near irrigated agriculture are advocating a transfer of water now utilized for irrigation to municipal use. Alternatives are presented whereby this water can be transferred to municipal use in exchange for treated sewage effluent. The irrigation water would in effect be cycled through the municipal system prior to use on the farms. A case study of the Tucson region illustrates the relevant legal, economic and technical aspects. Effluent could be delivered to irrigators in Avra Valley at a cost less than that now paid for water pumped from declining water tables. In return the City of Tucson could import ground water now being used for irrigation through an existing pipeline which presently cannot be used because of a court injunction obtained by the irrigators. It appears that such an exchange agreement could be made without modification of existing statutory law. Similar exchange arrangements may prove to be feasible in other regions containing irrigated agriculture. Increased efficiency of water use can be achieved avoiding external effects which commonly arise in a direct transfer and are difficult to evaluate. High quality water is allocated to municipal use whereas nutrient-rich sewage effluent is transferred to irrigation.  相似文献   
7.
ABSTRACT. In 1970, the Canadian Federal Government passed the Canada Water Act which provides for a co-operative federal-provincial approach to water resource management. The purpose of this paper is to outline our definition of comprehensive planning and the approach being taken under the new legislation. Two basic premises underly the definition. They are that resource management consists of an array of problems and that the prime function of planning is to provide information for decision making. The definition of comprehensive planning is embodied in a general statement and a set of principles. The principles define the approach that should be taken to provide adequate information for decision making in today's complex environment. A brief resume of the jurisdictions for water management in Canada leads to a discussion of a joint federal-provincial comprehensive study of the Qu'Appelle River Basin in Southern Saskatchewan. The basin and the study are described briefly. This is followed by an outline of the economic and social considerations which are being incorporated into the comprehensive planning study for the basin.  相似文献   
8.
A tax on waste-to-energy incineration of fossil carbon in municipal solid waste from households was introduced in Sweden on July 1, 2006. The tax has led to higher incineration gate fees. One of the main purposes with the tax is to increase the incentive for recycling of materials, including biological treatment. We investigate whether and to what extent this effect can be expected. A spreadsheet model is developed in order to estimate the net marginal cost of alternative waste treatment methods, i.e., the marginal cost of alternative treatment minus avoided cost of incineration. The value of the households’ time needed for source separation is discussed and included. The model includes the nine largest fractions, totalling 85% (weight), of the household waste currently being sent to waste incineration: food waste, newsprint, paper packaging, soft and hard plastic packaging, diapers, yard waste, other paper waste, and non-combustible waste. Our results indicate that the incineration tax will have the largest effect on biological treatment of kitchen and garden waste, which may increase by 9%. The consequences of an incineration tax depend on: (a) the level of the tax, (b) whether the tax is based on an assumed average Swedish fossil carbon content or on the measured carbon content in each incineration plant, (c) institutional factors such as the cooperation between waste incinerators, and (d) technological factors such as the availability of central sorting of waste or techniques for measurement of fossil carbon in exhaust gases, etc. Information turns out to be a key factor in transferring the governing force of the tax to the households as well improving the households’ attitudes towards material recycling.  相似文献   
9.
/ It has been suggested that the general public should be moreinvolved in environmental policy and decision making. It is important forthem to realize that they will have to live with the consequences ofenvironmental policies and decisions. Consequently, policy makers shouldconsider the concerns and opinions of the general public before makingdecisions on environmental issues. This raises questions such as: How can weintegrate the perceptions and reactions of the general population inenvironmental decisions? What kind of public participation should weconsider? In the present study, using a new regional ecosystem model, weattempted to integrate these aspects in its decision making model byincluding the formation of an advisory committee to resolve problems relatedto waste management. The advisory committee requested the activeparticipation of representatives from all levels of the community: economic,municipal, and governmental intervenors; environmental groups; and citizens.Their mandates were to examine different management strategies available inthe region, considering all the interdisciplinary aspects of each strategy,elaborate recommendations concerning the management strategies that are mostsuitable for all, and collaborate in communication of the information to thegeneral population. The results showed that at least in small municipalitiessuch an advisory committee can be a powerful tool in environmental decisionmaking. Conditions required for a successful consultation process, such aseveryday lay language and the presence of a facilitator other than ascientific expert, are discussed.KEY WORDS: Public consultation; Environmental policies;Interdisciplinary aspects; Municipal sewage sludge management; Generalpopulation; Decision-making process  相似文献   
10.
ABSTRACT: The desirable proportion of citizen input into policy making and the proper mechanism for that input engender substantial conflict in the water resources arena. Nevertheless, discussions of citizen participation in water policy formation generally occur within narrow perspectives both with regard to the issues involved and the alternative mechanisms by which that participation can be realized. This paper examines the historical and current contexts of the controversies and presents a discussion of the alternative processes for citizen influence - called linkage. The linkage processes discussed include direct participation, citizen advisory committees, the pressure group model, the electoral model and the bureaucratic model. Each linkage process is discussed in terms of who is considered the public, how the public influence works, the limitations of the process, and what available water policy-related data suggest regarding the adequacy of the process.  相似文献   
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