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991.
为解决危化品罐车的储罐阀门管线等关键部件易损坏造成危化品泄漏的问题,基于系统本质安全原理设计1种内置自封堵式安全截断阀并对其关键部件强度进行校核计算,建立实现阀芯阀座有效密封的三维实体模型并完成有限元分析。结果表明:在阀座密封面与球形阀芯接触处出现最大应力,阀座承受的最大应力小于材料的最大屈服应力,内置自封堵式安全截断阀具有较高的可靠性,可为危化品储运相关安全装置设计提供理论参考。 相似文献
992.
Major earthquakes have demonstrated that Natech events can be triggered by liquid overtopping in liquid storage tanks equipped with floating roofs. Thus, research on the dynamic behaviour of steel storage tanks with floating roofs is still required. In this paper, the seismic risk against liquid overtopping in a real steel storage tank with a floating roof was analysed using a simplified model that was validated by a refined finite element model based on the arbitrary Lagrangian-Eulerian approach. The simplified model utilizes the Lagrangian of a floating roof-fluid system and is capable of providing a response history of the floating roof. It was demonstrated that it could predict the maximum vertical displacement very accurately, while some differences were observed in the response history of vertical displacement. The computational time for a single response history analysis based on the simplified model amounted to a few minutes, which is significantly less demanding compared to hours required for response history analysis in the case of the refined FE model. The simplified model is thus appropriate for the seismic fragility analysis considering the overtopping limit state. It is shown that the fragility curves are significantly affected by the liquid filling level. The risk for liquid overtopping is quite high in the case of a full tank. However, by considering the variation of filling level during the year, the overtopping risk was observed reduced by approximately 30%. Alternatively, the approximate fragility analysis for the liquid overtopping can be performed by utilizing the Eurocode formula for the vertical displacement of liquid. This approach is straightforward, but the formula does not account for the higher mode effects, which may result in overestimated seismic intensity causing overtopping, as discussed in the paper. 相似文献
993.
通过场地污染情况调查对某土壤有机污染的环境损害进行鉴定评估,分析了污染物性质、事件发生的空间范围及时间范围,对环境损害进行了量化,以期为相关案例评估提供依据。 相似文献
994.
以石家庄某机械制造企业搬迁遗留场地为例,结合分区与专业判断进行土壤调查与分析。结果表明:27个点位不同深度土壤样品中,氰化物、六价铬及多氯联苯均未检出。检出重金属6种,总石油烃2种、苯系物3种,但均未超标。污染主要来源是原辅材料堆存和在工艺过程中遗撒、泄漏迁移所致。 相似文献
995.
随着我国社会经济发展进程的不断推进,建筑行业发展趋势也有了空前的提高。基于这样的发展态势,建筑行业市场中竞争越来越激烈。建筑工程在施工现场的安全和环境保护问题与企业的经济效益、人们的健康、生命安全有着很大的关系。建筑工程施工现场安全和环境管理措施的有效程度,决定着企业的管理水平,也能在很大程度上影响企业的发展。 相似文献
996.
Benefit‐Cost Analysis of Integrated Water Resource Management: Accounting for Interdependence in the Yakima Basin Integrated Plan 下载免费PDF全文
Jonathan Yoder Jennifer Adam Michael Brady Joseph Cook Stephen Katz Shane Johnston Keyvan Malek John McMillan Qingqing Yang 《Journal of the American Water Resources Association》2017,53(2):456-477
Integrated water resource management (IWRM) requires accounting for many interrelated facets of water systems, water uses and stakeholders, and water management activities. The consequence is that project analysis must account for the nonseparability among the component parts of IWRM plans. This article presents a benefit‐cost (B‐C) analysis of a set of projects included in the Yakima Basin Integrated Plan proposed for the Yakima Basin in south‐central Washington State. The analysis accounts for interdependence among proposed water storage projects and between water storage and water market development in the context of historical and more adverse projected future climate scenarios. Focusing on irrigation benefits from storage, we show that the value of a given proposed storage project is lower when other proposed storage projects in the basin are implemented, and when water markets are functioning effectively. We find that none of the water storage projects satisfy a B‐C criterion, and that assuring proposed instream flow augmentation is less expensive by purchasing senior diversion rights than relying on new storage to provide it. 相似文献
997.
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999.
Ambient concentrations of PM2.5 and PM10 are of concern with respect to effects on human health and environment. Increased levels of mortality and morbidity have been associated with respirable particulate air pollution. In India, it is not yet mandatory to monitor PM2.5 levels therefore very limited information is available on PM2.5 levels. To understand the fine particle pollution and also correlate with PM10 which are monitored regularly in compliance with ambient air quality standards. This study was carried out to monitor PM2.5, PM10, and NO2 for about one year in a residential cum commercial area of Mumbai city with a view to understand their correlation. The average PM2.5 concentration at ambient and Kerbsite was 43 and 69 μg/m3. The correlation coefficients between PM2.5 and PM10 at ambient and Kerbsite were 0.83 and 0.85 respectively thus indicating that most of the PM2.5 and PM10 are from similar sources. TSP, PM10 levels exceeded Central Pollution Control Board(CPCB) standard during winter season. PM2.5 levels also exceeded 24 hourly average USEPA standard during winter season indicating unhealthy air quality. 相似文献
1000.
简述了当前静力触探的现状与发展。介绍了国际最新研制的RCPTU(电阻率孔压静力触探)探头和多功能静力触探技术在污染场地评价、地下水污染和垃圾填埋场地下水位高度评估等环境领域的应用及工程实例。指出了多功能静力触探测试技术研究中存在的问题,展望了其应用前景。 相似文献