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Urinary calculi have been recognized as one of the most painful medical disorders. Tenable knowledge of the phase composition of the stones is very important to elucidate an underlying etiology of the stone disease. We report here the results of quantitative X-ray diffraction phase analysis performed on 278 kidney stones from the 275 patients treated at the Department of Urology of Hadassah Hebrew University Hospital (Jerusalem, Israel). Quantification of biominerals in multicomponent samples was performed using the normalized reference intensity ratio method. According to the observed phase compositions, all the tested stones were classified into five chemical groups: oxalates (43.2%), phosphates (7.7%), urates (10.3%), cystines (2.9%), and stones composed of a mixture of different minerals (35.9%). A detailed analysis of each allocated chemical group is presented along with the crystallite size calculations for all the observed crystalline phases. The obtained results have been compared with the published data originated from different geographical regions. Morphology and spatial distribution of the phases identified in the kidney stones were studied with scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). This type of detailed study of phase composition and structural characteristics of the kidney stones was performed in Israel for the first time.  相似文献   
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Accessible and transparent data on the social costs of externalities is crucial to waste management researchers, decision-makers, and managers, if waste management strategies are to be successfully analyzed and implemented. The primary objective of this study, which is based on a thorough review of existing literature and research, was to assist the abovementioned in their decision-making with reliable recent data, by mapping, gathering, analyzing, and comparing different valuation results of external costs associated with various types of pollution and disamenities related to landfilling and incineration of solid waste.The second objective was to assess the suitability and reliability of various valuation methods and techniques that were implemented in the reviewed valuation studies, as well as the transferability of valuations across sites.The paper focuses on studies conducted since 1990, because in dynamic fields such as the waste sector, externalities, and valuation, it is essential to stay current with the most recent information and valuations.We discuss the issues and the limits of the valuation techniques and analyze the estimates of all the studies, presenting the results in the form of intervals and averages of damage costs. In spite of the inconsistencies evident in the variability in the results we reviewed, the outcome of this first comprehensive critical analysis is significant and the valuations obtained in this study provide estimates of orders of magnitude of external costs that can be used by decision makers in the waste sector to address important policy questions associated with social welfare.  相似文献   
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Samples of Jerusalem limestones were exposed to high levels of common air pollutants (SO2, NO) in the presence and absence of hydrocarbon, water vapor and ultra-violet light. After exposure, the outer layers were shaved off and analyzed for sulfate and nitrate. The results revealed that even after one day of exposure significant concentrations of CaSO4 and Ca(NO3)2 could be detected in the external 40 m layers. Sulfate formation was found to relate very strongly to relative humidity with nearly undetectable production at humidities below 10%. Nitrate formation was found to relate to UV light and to a limited extent to the presence of hydrocarbon but was unchanged at different humidities. Surface samples were taken from different sites of the old city wall and were also analyzed for the same substances. The data showed that the concentrations of especially CaSO4, and to a limited extend Ca(NO3)2, measured at various points along the city walls were higher than the expected values extrapolated from laboratory simulations. The elevated pollution content may be explained in part due to the deposition of transported ions, especially sulfate, onto the stone surface. It was concluded that although air pollution may not cause any structural damage in the foreseeable future it definitely deteriorates the fine details of the ancient monument.  相似文献   
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Household Demand for Waste Recycling Services   总被引:1,自引:0,他引:1  
Municipalities everywhere are coping with increasing amounts of solid waste and need urgently to formulate efficient and sustainable solutions to the problem. This study examines the use of economic incentives in municipal waste management. Specifically, we address the issue of recycling, if and when this waste management option is—on social welfare grounds—a preferred solution.A number of studies have recently assessed the monetary value of the externalities of alternative solid waste management options. In the present context, these subsidies could be interpreted as the implicit value of the benefits from reducing environmental externalities associated with landfilling as perceived by local government authorities. We surmise that the difference between mean households willingness to pay (WTP) for recycling services, via the purchase of a subsidized waste disposal facility, and the above (proxy) value of externalities reflects the difference between private and public perception regarding the negative externality associated with landfilling. We believe that this information is useful in determining the level of subsidization needed (if at all) to sustain any recycling program.The study is unique in the sense that its conclusions are based on revealed household behavior when faced with increased disposal costs, as well as information on WTP responses in hypothetical but related (and, therefore, familiar) scenarios. The article also explores the influence of the subsidization schemes on recycling rates. It was found that with low levels of effort needed to participate in a curbside recycling program, households participation rates are mainly influenced by economic variables and age, and households are willing to pay a higher price for the recycling scheme. When the required effort level is relatively high, however, households would pay a lower price, and the rate is influenced mainly by their environmental commitment and by economic considerations. We found that in both cases a subsidy would be required in order to achieve an efficient level of recycling. The median price that households are willing to pay for recycling devices is found to be about NIS 370 (New Israeli Shekel, approximately $90).  相似文献   
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The primary objective of this study was to assist waste management researchers, decision-makers and waste managers at national, regional and local levels, in their decision-making processes, with most recent valuations on the environmental and social costs of externalities associated with various pollutants and disamenities related to landfilling and incineration of municipal solid waste. The aim was achieved by mapping, gathering, analysing, comparing and synthesizing various valuation estimates, based on a thorough review of existing literature. This study provides the first comprehensive review and analysis focused on primary and secondary valuation studies, conducted since 1990. The second objective was to assess the appropriateness and reliability of the valuation methods and techniques that were performed in the reviewed studies. The results of the review are summarized in tables, organized by topics and units of measure and in addition a classified list that describes the profile of the reviewed studies is provided. The results are then analysed and compared, and recommended ranges of the values are presented. The study reveals inconsistency in part of the estimates across the reviewed studies and provides reasonable explanations for the variations. Given the nature of uncertainty, and the difficulties associated with transferring values among different places and cases, these values should be considered mostly as an indication for the order of magnitude of the externalities. Nevertheless, these essential estimates of the external costs can beneficially be used with proper adjustment for each individual case to address important policy questions regarding landfilling and incineration of waste.  相似文献   
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Natural (estradiol, estrone, testosterone, estriol) and synthetic hormones (ethinylestradiol) are constantly excreted into the environment from human and animal sources but little is known of their transport. The purpose of this study was to determine how far along a 100 km river course that hormones could be detected after contamination with sewage effluent or fishpond effluent. Fourteen sites in the Lower Jordan River drainage were sampled (two sites above the sewage effluent contamination, eight sites below the contamination and four tributaries) before and after the dry season of 2002 (Spring and Fall). Samples were tested for testosterone, estrogen (estrone and estradiol combined), estriol, ethinylestradiol, ammonia and fecal coli. It was found that the fecal coli count dropped exponentially (from 250,000 to 60/100 ml3) and the ammonia dropped from 15 to less than 1mg/l over the initial 25 km stretch. Over the same stretch, the hormone values declined by half from their maximum values for testosterone (3.3 ng/l), estriol (8.8 ng/l), ethinylestradiol (6.1 ng/l), and estrogen (4.9 ng/l). From 67 to 100 km mark, testosterone (4.8 ng/l) and estrogen (2.4 ng/l) were still elevated while ethinylestradiol and estriol were >or=1.5 ng/l. The high level of testosterone and estrogen between 67 and 100 km marks was probably due to major discharge from fishponds between 23 and 27 km marks. Levels of ethinylestradiol above 1 ng/l, a level which can affect fish, was seen in 70% (12/16) of the samples tested. The data suggest that hormones in readily measured quantities can be transported considerable distances from the source of pollution.  相似文献   
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Spatial planning typically involves multiple stakeholders. To any specific planning problem, stakeholders often bring different levels of knowledge about the components of the problem and make assumptions, reflecting their individual experiences, that yield conflicting views about desirable planning outcomes. Consequently, stakeholders need to learn about the likely outcomes that result from their stated preferences; this learning can be supported through enhanced access to information, increased public participation in spatial decision-making and support for distributed collaboration amongst planners, stakeholders and the public. This paper presents a conceptual system framework for web-based GIS that supports public participation in collaborative planning. The framework combines an information area, a Multi-Criteria Spatial Decision Support System (MC-SDSS) and an argumentation map to support distributed and asynchronous collaboration in spatial planning. After analysing the novel aspects of this framework, the paper describes its implementation, as a proof of concept, in a system for Web-based Participatory Wind Energy Planning (WePWEP). Details are provided on the specific implementation of each of WePWEP's four tiers, including technical and structural aspects. Throughout the paper, particular emphasis is placed on the need to support user learning throughout the planning process.  相似文献   
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