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101.
The purpose of this paper is to provide a helpful tool for the design of adsorption equipment, recognizing in particular the recent, more stringent regulations on air pollution. This work is based on an earlier paper by Hougen and Marshall,1 who developed therein an analytical adsorption model. Under certain assumptions, especially that of linear adsorption equilibrium, it is possible to express the results in the form of convenient usable charts. Although more sophisticated models2 have recently been developed, the numerical effort involved in solving the associated partial differential equations is such that practical application is often questionable.  相似文献   
102.
Apart from analyses for elemental contaminants in field collected specimens, very little is known about the assimilation, accumulation and toxic effects of inorganic contaminants in reptiles. This study examined the chronic accumulation of Cd in a European lacertid lizard (Podarcis carbonelli) following dietary provision of an environmentally realistic concentration of Cd for 21 weeks. Lizards were provided with Cd that had either been biologically incorporated into crickets, or as Cd(NO3)2 added superficially to crickets just prior to feeding. Among both treatment groups Cd accumulated in tissues in the following order of concentration: gut>liver>kidney>carcass. The majority of the Cd was retained within the gut, and transfer to internal organs was low. Morphological indices, brain and plasma cholinesterase activities, gut and liver metallothionein content, and standard metabolic rate were measured as biomarkers of exposure and effect; however, no differences between control lizards and Cd-treated lizards were observed.  相似文献   
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While economic research on environmental policy is mainly concerned with instruments, political science concentrates on actors. The issue of centralisation needs to be analysed using a multidisciplinary approach because it is connected with both actors and instruments. Linking the Advocacy Coalition Framework with an economic approach, the paper first develops an innovative model in order to understand the mechanisms of centralisation and decentralisation in the different phases of policy processes. Focusing on environmental policy, the idea is developed that environmental policy needs the push of centralisation in order to institutionalise the prevailing social norm, but then should be organised decentrally to account for regional differences. The examples of air pollution, climate change and urban sprawl are used to test the explanatory power of the theoretical approach.  相似文献   
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The choice between organic and conventional agriculture for farmers is modeled as an ethical decision. Farmers are either loyal to one of the systems or they optimize between systems. This model is empirically validated through a survey among Swiss farmers. A cluster analysis separates farmers into loyal organic, loyal conventional, and optimizing farmers. However, the three resulting clusters bore some, but not all the necessary characteristics of “optimizers” and “loyals.” A probit analysis shows that loyal farmers have larger farms than optimizers. Loyal organic farmers receive less direct payments than optimizers, which confirms the utility-maximizing pattern of the latter group.  相似文献   
107.
ABSTRACT: A series of studies and experiments were conducted to identify rural water supply quality problems and to develop and demonstrate solutions. We found that rural people had severe and widespread problems, while state agencies held potential answers. Communications between experts and town officials were weak or absent. To bridge this gap, an information system was devised and tested. A computer program was developed to provide a printout map of the state, showing town boundaries and the quality of water supplies for each public water system monitored by the State Health Department. The map and data were published in local newspapers with an explanation of the map and its symbols. Town health officers were interviewed to determine the results of the public disclosure. We found that the news releases led to increased awareness, interest, and understanding of water quality and demands for ameliorative action. This program was supplemented by two publications: “A Layman's Guide to Eutrophication” and “A Handbook for Rural Water Uses.” The handbook explains the nature of drinking water standards, the reasons for these standards, the dangers and results of not meeting the standards, and cost-effective alternatives for improving water quality.  相似文献   
108.
当前,我国河流污染的监测、研究与治理甚少考虑微生物指标,导致国内大多河流的微生物污染状况不明.本研究以海河流域上游山区段永定河(张家口市)、中游平原段温榆河(北京市)和下游滨海段北运河(天津市)3段典型河流为对象,选取粪大肠菌群、大肠杆菌、肠球菌、SC噬菌体为指示微生物指标,开展了历时1年的野外调查,以期明确海河流域典型河流微生物污染的浓度水平及其时空分布特征.结果表明:除有机污染和富营养化问题外,3条河流也受到了较为严重的微生物污染.监测断面的肠球菌、大肠杆菌、粪大肠菌群、SC噬菌体的年平均浓度分别在1.039×103~9.168×105CFU·L-1、10~1.870×106CFU·L-1、1.43×102~8.105×106CFU·L-1、0~4.77×106PFU·L-1之间.曼-惠特尼U检验分析结果表明,流域内指示微生物浓度分布的季节性变化不显著;3条河流中,中游平原段温榆河因受污水处理厂退水排入河道的影响,微生物污染水平最高;上游山区段永定河虽有机污染较轻,但动物粪便污染严重,导致河流微生物污染状况亦不容乐观.为保障流域公共卫生安全和地下水安全,上游山区段农村畜禽粪便处理、中游平原段污水处理厂退水应得到进一步的关注与管理.  相似文献   
109.
PROBLEM: We report on trends in road rage victimization and perpetration based on population survey data. METHOD: Based on repeated cross-sectional telephone surveys of Ontario adults between July 2001 and December 2003, logistic regression analyses examined differences between years in road rage victimization and perpetration in the previous year controlling for demographic characteristics. RESULTS: The prevalence of any road rage victimization in the previous year decreased significantly from 47.5% in 2001 to 40.6% in 2003, while prevalence of any road rage perpetration remained stable (31.0% to 33.6%). Logistic regression analyses revealed that the odds of experiencing any road rage victimization was 33% higher in 2001 and 30% higher in 2002, than in 2003. DISCUSSION: Survey data provide a valuable perspective on road rage trends, but efforts to track road rage incidents is also needed. SUMMARY: In Ontario, the proportion of adults experiencing any road rage victimization decreased from 2001 to 2003 while the proportion reporting any road rage perpetration remained stable. IMPACT ON INDUSTRY: None.  相似文献   
110.
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