The Surface Roughness of a Rubber Soling Material Determines the Coefficient of Friction on Water-Lubricated Surfaces

For more than a decade, evidence has been accumulating that points to the fact that the microscopic roughness of the footwear soling surface is a major determinant of slip-resistance on lubricated surfaces, but conclusive experimental proof has been lacking. This article describes an experiment in which five pairs of shoes were soled with the same rubber compound. Four of the pairs were abraded by different grades of grit to produce a range of roughness values. The coefficient of friction (CoF) of the five solings was then measured repeatedly by the walking traction method on wet surfaces including glazed wall tiles, vinyl asbestos coated with the wax floor polish, and both sides of a sheet of float glass. The Kruskal-Wallis statistical test proved beyond doubt that the soling roughness is a major factor in determining the CoF of this rubber soling material; p < 10⁻⁵. Nearly all of the grip was due to surface roughness of the soling material on these atypically smooth floors, although the surface roughness of the floors also had a significant effect on CoF; p < 0.003. Float glass is shown to be a promising reference floor material for the measurement of CoF of footwear; there was no statistical difference between results for the two sides of the glass sheet. Float glass could be used in the development of a standard CoF test method because new sheets of glass from the same manufacturer are identical and extremely smooth. The specification of CoF values for solings/floors combinations in lubricated conditions is of little value unless associated with roughness measurements and knowledge of how wear will affect the surface roughness of the sole. This article reports the first evidence that any specification of flooring by measuring CoF based on dry surfaces could lead to an increase in the number of injuries caused by slipping on the wet surfaces. Published by Elsevier Science Ltd     

设备滚动轴承损坏程度快速鉴定法

滚动轴承是设备中的易损件。介绍了鉴定滚动轴承损坏程度的快速鉴定方法,以决定是否更换轴承,从而降低了检修费用。     

生物絮凝在校园生活污水处理中的应用研究

将高效生物絮凝剂产生茵V3,V11,V13应用于校园生活污水处理中,可有效提高水处理絮凝效果。试验结果表明：当SBR反应器曝气时间3h,投菌量50g/L,温度28—30℃,V3对OD550,NH3-N,COD,浊度去除率分别达91．5％．82％,91．3％,93．5％,V11对OD550,COD,浊度去除率分别达89．1％,91．5％,95．1％,对NH3-N去除率较低;V13对OD550,COD,浊度去除率分别达90．7％,93.3％,92．1％,对NH3-N几乎没有去除;3株菌混合培养,3株菌形成一种互生关系．应用于水处理中当SBR曝气时间3h,投菌量50g／L,温度28～30℃,对OD550,NH3-N,COD,浊度去除率分别达93.3％,86．7％。93．5％,96％,同时能有效的改变污泥沉降性能．     

含铬废渣炻质砖固体块长期稳定性试验和加速试验

在制砖基料中加入２０％铬渣,制成所要求几何形试块,按给定的烧成温度烧成试块,测量烧成块几何尺寸和烧成前后试块所含水溶样Ｃｒ（Ⅵ）值,将烧成试块置于不同条件的浸出液中进行长期浸取,根据Ｉａ的浸出数据,浸出率ＬＲ＝０．８×１０＾－７ｃｍ／ｄ,累积浸出分数ＬＦ＝１×１０＾－４ｃｍ,判断炻质砖试块中Ｃｒ（Ⅵ）的稳定程度,从而判定此处理铬渣方法的可行性。     

石棉摩擦材料废弃物制吸附剂对染料的吸附研究

以石棉摩擦材料加工废弃物为材料制得的吸附剂,在色度５０００倍溶液中对阳离子黄Ｘ－５ＧＬ的静态吸附量为１５９．６８ｍｇ／ｇ,在色度５００倍的溶液中对阳离子艳蓝ＲＬ的静态吸附量为７９．６８ｍｇ／ｇ;对毛纺厂腈纶染缸废水的处理量可达２８０ｍｌ／ｇ,对活性染料亦有较好的吸附效果,吸附饱和吸附剂可通过后处理实现资源化。     

环境承载力的本质及其定量化初步研究

环境承载力描述了环境系统对人类活动支持能力的阈值,是环境系统功能的外在表现,是包含时间、空间和经济行为等自变量的函数。通过环境承载力指标体系及其综合值的计算可以描述实际环境承载量和环境承载力的大小,通过环境承载率（环境承载量／环境承载力）的计算可反映环境承载力的超载状况或环境与经济的协调程度。并以实例对环境承载力进行分析。     

摩擦摆隔震支座理论分析与数值模拟研究

介绍了摩擦摆隔震支座的基本构成和隔震原理.利用力学平衡原理,对摩擦摆隔震支座进行了理论分析,推导了摩擦摆隔震支座的刚度和等效粘滞阻尼比,构造了摩擦摆隔震支座的滞回模型,并探讨了该支座的自回复能力,得到了其最大残余位移计算公式.采用有限元软件ABAQUS,对摩擦摆隔震支座进行实体单元建模,模拟低周反复荷载作用下,该支座的...     

考虑峰后软化的圆形巷道稳定性分析及工程应用

为获得更准确的巷道围岩应力分布和变形特征,基于统一强度理论,考虑围岩塑性软化和中间主应力的影响,引入塑性软化参数,推导出巷道围岩弹塑性区应力、塑性区范围和位移的表达式。通过算例分析,得到塑性软化系数和中间主应力等相关参数对巷道围岩应力分布、塑性区半径和位移的影响规律。研究结果表明:随内摩擦角软化系数和黏聚力软化系数的增大,围岩塑性区半径和位移呈现先急剧后缓慢的减小趋势;中间主应力系数对巷道围岩弹塑性应力有着显著影响,中间主应力系数越大,围岩塑性区半径和位移越小。     

基于RepastS平台的太湖水环境系统承载力研究

运用计算实验方法,以计算机为工具,构造太湖水环境系统承载力模型,通过研究水和人类的各主体行为得出太湖水环境系统的整体特征,并通过人口、TP、TN、CODMn承载度来反映。研究结果表明太湖目前点源污染得到了有效控制,但面源污染和城镇生活用水污染尚需要重点治理。实验显示:通过系统参数的调整,将大大改善太湖现有水环境系统。     

线性规划法计算工业区大气承载力的探讨

分析了目前我国常用的模拟法、线性规划法和A-P值法三种大气承载力计算方法各自的缺点和局限性,探讨了线性规划法在工业园区规划环评大气承载力计算中的应用。以福建省某石化工业园区为实例,采用线性规划法计算了大气环境对SO2的承载力并用模拟法进行验证,计算结果10846t/a与模拟法结果13141t/a吻合性较好,表明线性规划法是计算区域大气承载力的科学可行的方法。