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101.
A study of a large number of samples of flaking old paint from various buildings in Bergen, Norway (N = 68) suggests that paint may be the most important contemporary source of PCBs in this urban environment with concentrations of PCB7 up to 3.39 g/kg. Twenty-three of the samples were collected from a single building, and the concentrations were found to vary over 3 orders of magnitude. In addition, 16 concrete samples from a large bridge previously coated with PCB-containing paint were collected and separated into outer- and inner samples indicating that PCBs are still present in high concentrations subsequent to renovation. PCBs were found in several categories of paint from wooden and concrete buildings, potentially introduced to the environment by natural weathering, renovation, and volatilization. Consequently, this dispersion may lead to increased levels of PCBs in urban atmospheres, soils, and harbor sediments where high concentrations have resulted in Governmental advice against consumption of certain seafood.  相似文献   
102.
This study presents a framework of decision analysis on fire safety design alternatives based on evaluating building fire risk to life. A probabilistic risk assessment method for occupant life is presented with consideration of some uncertainties of evacuation process and fire development at first. For occupant evacuation time assessment, occupant pre-movement time is characterized by normal distribution. For onset time to untenable conditions assessment, its uncertainty is considered as probability distribution according to the range of design fires. Based on event tree technique, probable fire scenarios are analyzed with consideration of the effect of fire protection systems, employees extinguishing, etc. It is difficult to make a precise assessment on probability and consequence of every fire scenario, but their lower bound and upper bound can be achieved based on statistical data. Therefore, Supersoft Decision Theory [Malmnäs, P.E., 1995. Methods of Evaluation in Supersoft Decision Theory. Department of Philosophy, Stockholm University, 365 Stockholm; Johansson, H., Malmnäs, P.E., 2000. Application of supersoft decision theory in fire risk assessment. Journal of Fire Protection Engineering 14, 55–84] that allows decision maker to utilize vague statement is utilized to integrate with risk assessment to make decision on different fire safety design alternatives. To express how to make decision on different fire safety design alternatives based on evaluating building fire risk to life, two hypothetical fire safety design alternatives for a commercial building are presented.  相似文献   
103.
Little is known about how the condition of school facilities affects academic outcomes. This study examines the role of school attendance as a mediator in the relationship between facilities in disrepair and student grades in city and state tests. Data on building condition and results from English Language Arts (ELA) and Mathematics (Math) standardized tests were analyzed using a sample of 95 elementary schools in New York City. Variables relevant to academic achievement such as ethnicity, socioeconomic status, teacher quality, and school size were used as covariates. In run-down school facilities students attended less days on average and therefore had lower grades in ELA and Math standardized tests. Attendance was found to be a full mediator for grades in ELA and a partial mediator for grades in Math. This study provides empirical evidence of the effects of building quality on academic outcomes and considers the social justice issues related to this phenomenon.  相似文献   
104.
In this work the feasibility of using woody agricultural biomass wastes as grapes and cherries seeds, sawdust, as pore forming agent, and sugar cane ash, as silica precursor, in bricks, were reported.Sawdust and grapes and cherries seeds, thanks to their organic substances content, during their combustion, bring an energetic support in the bricks firing phase and act as pore forming agent. Usually the addition of this kind of waste is limited to 10 wt.% in order to reach an equilibrium between positive (weight and shrinkage decrease and porosity increase) and negative (increase of water absorption and mechanical resistance decrease) effects. The results show that grapes and cherries seeds, added in a percentage of 5 wt.% to a brick formulation, have better influence with respect to the sawdust, maintaining the mechanical properties of the fired brick (950 °C), showing modulus of rupture around 21–23 MPa with a weight reduction of 3–10% (respect to the standard one). Regarding the sugar cane ash, the addition of 5 wt.% improves the mechanical properties (modulus of rupture around 27 MPa) and no weight decrease is observed. These results confirmed the role played by this kind of agricultural waste, which thanks to its high silica content (61 wt.%) is capable to demonstrate a filler and plasticity reducing effect on the brick bodies. Tests carried out highlighted that the addition of these by-products (5 wt.%) do not change negatively the main technological properties measured (water absorption, linear shrinkage, flexural resistance, etc.) and permit to hypothesize their use to obtain bricks with both insulating and higher mechanical properties using a pore agent forming or silica carrier alternative raw materials, respectively.  相似文献   
105.
本文以个体生活资源基本需求为计算单位,探讨四川省主要生态资源能承载多少人口,预测四川省人口发展与生态资源的关系.根据本文给出的计算结果,四川省耕地费源已经饱和,其复耕事较高尚能满足人口需求;牧草场资源超载,面临荒漠化威胁;森林资源较为丰富,能够满足人口发展需求;水资源与人口关系富足有余,但工业污水排放和上游水源保护仍需给予关注.面对这一现实,四川省要进一步推行控制人口增长的生育政策;保护现有耕地资源,发展生态农业;合理规划草场资源,科学发展畜牧业;合理开发森林蕴藏资源,坚持合理采伐;加强水利设施建设,防治水污染,确保水资源可持续利用.  相似文献   
106.
Abstract

China is a developing country experiencing rapid economic growth. In recent years, increased urbanization has caused a tremendous rise of the energy consumption of buildings, and a corresponding need is to save this energy. In this article, the technologies and laws relative to building energy saving in China were presented which include building construction, the compound building energy system, policies, and the law etc. In order to fulfill the three stages of energy saving plan in building construction in China, the principal methods for developing building energy saving are introduced.  相似文献   
107.
区域环境承载力与工业布局研究   总被引:2,自引:0,他引:2  
利用区域环境承载力理论对城市工业布局进行了探讨,提出了工业布局合理度的概念,并将它应用于北海市的城市环境规划之中,对其工业布局现状进行了评价.  相似文献   
108.
就当前人们关注的建筑结构安全问题,结合系统失效规律,提出对建筑结构全过程实施可靠性鉴定,从而有效地控制了建筑结构倒塌事故。  相似文献   
109.
我国环境监测能力建设的现状及建议   总被引:15,自引:0,他引:15  
对我国环境监测能力建设的现状进行了分析。指出我国环境监测能力建设取得了明显进展 ,但地区差异很大 ,整体水平不高 ,存在的主要问题是投入不足、体制不顺。提出应加强环境监测管理 ,加大投入 ,建设水质、空气、重点污染源自动监测系统 ,建立国家级开放式环境分析实验室和全国生态与环境监测网络 ,完善数据卫星传输系统 ,全面提高环境监测能力。  相似文献   
110.
Community-based conservation projects implemented in conjunction with protected area management often struggle to meet expectations. This article argues that outcomes will improve if project leaders pay closer attention to four development indicators—rights, capacity, governance, and revenue—that are often taken for granted or considered beyond the scope of local conservation projects. I make the case for focusing on these variables in four steps. First, I distinguish community-based conservation linked to protected area management from community-based institutions studied by scholars of the commons. Second, I draw on the theory and practice of international development to highlight the central relevance of the variables highlighted in this article to development projects at all levels. Third, I discuss the four variables in some detail, considering problems of definition and measurement and reviewing possible interactions among them. Fourth, to illustrate the influence of the variables in particular cases, I review outcomes from community-based conservation projects implemented near protected areas in El Salvador and Zimbabwe.  相似文献   
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