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961.
Ship board testing of a deoxygenation ballast water treatment 总被引:2,自引:1,他引:1
McCollin T Quilez-Badia G Josefsen KD Gill ME Mesbahi E Frid CL 《Marine pollution bulletin》2007,54(8):1170-1178
A ship board trial of a deoxygenation method for treating ballast water was carried out during a voyage from Southampton (United Kingdom) to Manzanillo (Panama). A nutrient solution added to two ballast tanks encouraged bacterial growth, resulting in a gradual change to an anoxic environment. Samples were taken from two treated tanks and two untreated tanks to assess changes in the abundance and viability of zooplankton, phytoplankton and bacteria. The work was carried out before the International Maritime Organization (IMO) standard was agreed so only a broad indication of whether the results achieved the standard was given. For the zooplankton, the standard would have been achieved within 5 or 7 days but the phytoplankton results were inconclusive. The biological efficacy was the result of the combination of several factors, including the treatment, pump damage and an increase in the water temperature during the voyage. 相似文献
962.
Numerical modelling of flood inundation over large and complex floodplains often requires mesh resolutions coarser than the structural features (e.g. buildings) that are known to influence the inundation process. Recent research has shown that this mismatch is not well represented by conventional roughness treatments, but that finer‐scale features can be represented through porosity‐based subgrid‐scale treatments. This paper develops this work by testing the interactions between feature representation, subgrid‐scale resolution and mesh resolution. It uses as the basis for this testing a 2D diffusion‐based flood inundation model which is applied to a 2004 flood event in a topologically complex upland floodplain in northern England. This study formulated simulations with different grid mesh resolution and subgrid mesh ratio. The sensitivity of the model to mesh resolution and roughness specification was investigated. Model validation and verification suggest that the subgrid treatment with higher subgrid mesh ratio can give much improved predictions of flood propagation, in particular, in terms of the predicted water depth. This study also highlighted the limitation of using at‐a‐point in time inundation extent for validation of flood models of this type. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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东太湖堤线调整大堤由黏性土水力吹填形成,填土中含大量鹅卵状土块.本文通过野外勘察、室内试验等方法初步研究分析黏性吹填土形成机理、内部结构特点、力学特性等.研究结果表明:吹填土体性质不均匀,鹅卵状土块土性较好,而重塑淤泥质黏土土性极差.黏性吹填土的渗透系数很小,固结所需时间长.其室内土工试验参数与现场实际不符,其原因是现... 相似文献
966.
为达到该滑坡的综合治理,对其进行详细工程地质勘察、滑坡成因研究和稳定性分析.在此基础上综合考虑当地建材来源和施工便利,通过治理方案比选,提出抗滑挡墙和抗滑桩相结合的治理方案. 相似文献
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煤矿在开采煤炭的同时,会有大量的矿井污水排到地面,造成环境污染。为解决矿井水排放的污染问题,施工大口径回灌井和建造地面水净化处理厂,矿井水经处理后部分用于煤矿生产,多余部分通过回灌井注入地下,实现水资源循环利用和节能减排。通过梧桐庄矿工程实例,介绍了煤矿矿井水净化处理与回灌治理技术。 相似文献
970.
根据福建三明荆山矿区ZK1402孔深孔钻探实践,总结在多段漏水破碎地层钻进中,采用多种堵漏措施和优质泥浆护壁的方法解决钻遇技术难题的经验。 相似文献