Experimental and numerical analysis of the influence of cable tray arrangements on the resulting mass loss rate and fire spreading

In the context of industrial buildings and power plants, electrical installations and cable trays represent a main fuel load and a potential initial fire source due to possible short circuits or comparable malfunction. Furthermore, a fire can spread from one tray to additional trays mounted above and/or horizontally on one tray. Because of the high significance of cable fires, several research projects have been carried out, investigating the fire behaviour of cables from small‐scale tests, eg, the cone calorimeter, up to large‐scale tests, analysing complete cable tray constructions. The goal of the work presented in this paper is the extension of the knowledge regarding the influence of geometrical parameters like the packing density and tray distance on the burning behaviour and fire spread of cable tray installations. The results are considered, together with test results from the literature, to quantify the main physical parameters describing the burning behaviour. In a next step, the general applicability of these parameters as input data for the parametrization of the source term of numerical simulations is shown. The test results show that the burning behaviour and the fire spreading highly depend on the cable arrangement of the cables on the cable tray, in combination with other boundary conditions. By applying the results as input for a fire simulation, the mass loss rate is considered appropriately.     

Laboratory and Field Consumer Evaluation Relationships for Menu Items Processed in Retortable Trays for Quantity Foodservice

Problems associated with provision of food in quantity foodservices prompted the development and use of prepared food items processed in retortable trays. Consumer acceptance of such foods was required so that the items could be screened for foodservice application. Consumer tests, using small portion samples and sensory testing under laboratory conditions, gave a relatively reliable prediction of acceptability of most of the items under extended-use consumer testing during a field trial. Final field acceptance of some items was influenced by external factors not accounted for in laboratory testing.     

填料-旋流板脱硫塔在净化加压变脱改造中的设计与应用

阐述了以塑料阶梯环填料与带溢流锥双程叶片旋流塔板组合的新型复合脱硫塔的设计开发,其结构特点为旋流板塔板采用了双程叶片结构,溢流装置采用新型带螺旋叶片结构,塔上部设置高2.53m填料层,改进并优化了喷淋装置及气体进、出口结构等。通过实际应用,证明该型脱硫塔在净化加压变换气脱硫工序中的应用是成功的。     

Novel Redox-Dependent Esterase Activity (EC 3.1.1.2) for DJ-1: Implications for Parkinson’s Disease

Mutations the in human DJ-1 (hDJ-1) gene are associated with early-onset autosomal recessive forms of Parkinson’s disease (PD). hDJ-1/parkinsonism associated deglycase (PARK7) is a cytoprotective multi-functional protein that contains a conserved cysteine-protease domain. Given that cysteine-proteases can act on both amide and ester substrates, we surmised that hDJ-1 possessed cysteine-mediated esterase activity. To test this hypothesis, hDJ-1 was overexpressed, purified and tested for activity towards 4-nitrophenyl acetate (pNPA) as µmol of pNPA hydrolyzed/min/mg·protein (U/mg protein). hDJ-1 showed maximum reaction velocity esterase activity (V_max = 235.10 ± 12.00 U/mg protein), with a sigmoidal fit (S_0.5 = 0.55 ± 0.040 mM) and apparent positive cooperativity (Hill coefficient of 2.05 ± 0.28). A PD-associated mutant of DJ-1 (M26I) lacked activity. Unlike its protease activity which is inactivated by reactive oxygen species (ROS), esterase activity of hDJ-1 is enhanced upon exposure to low concentrations of hydrogen peroxide (<10 µM) and plateaus at elevated concentrations (>100 µM) suggesting that its activity is resistant to oxidative stress. Esterase activity of DJ-1 requires oxidation of catalytic cysteines, as chemically protecting cysteines blocked its activity whereas an oxido-mimetic mutant of DJ-1 (C106D) exhibited robust esterase activity. Molecular docking studies suggest that C106 and L126 within its catalytic site interact with esterase substrates. Overall, our data show that hDJ-1 contains intrinsic redox-sensitive esterase activity that is abolished in a PD-associated mutant form of the hDJ-1 protein.     

如何提高服装表演中的音乐水平

服装表演是一门融音乐、灯光、服装、造型为一体的舞台表演艺术，其中，音乐的作用不容忽视．本文试图分析音乐在服装表演中的作用，探索提高秀场DJ、服装设计师、服装模特音乐素养的有效途径，力求音乐与服装、音乐与表演的完美结合．     

大型塔板液体等停留时间分布的研究(Ⅰ)--实验测试方法和液流分布模式分析

大型塔板上液体的不均匀流动会严重降低塔板效率，液体等停留时间分布能直接反映咎板上液体的不均匀流动状况和真实流动特性，能由等停留时间分布预测塔板效率，并据此提出改善塔板效率的措施．介绍了测试大型塔板上液体等停留时问分布的四类方法：摄像法、电导法、光纤法和温度示踪法，评价了各类方法的优缺点，并综述了单溢流塔板、双溢流塔板、DJ塔板和导向筛板四种具有代表性塔板的液体等停留时间分布曲线．认为由于DJ塔板与导向筛板采用了合理的改进措施，使得液流分布更均匀．     

复合塔流体力学性能研究

通过冷模实验探讨了复合塔流体力学性能 .以水 -空气为系统 ,采用穿流筛板与不同直径或不同装填厚度的拉西环填料 ,并与普通穿流筛板进行比较 .实验结果表明 ,复合塔板压降小 ,雾沫夹带量小 .关联的实验数据 ,可供设计与研究使用 .     

舌形变截面增压器的平台试验与匹配特性

在分析舌形变截面蜗壳工作原理的基础上,提出设计构思。经平台试验可知,舌形挡板可变截面对柴油机性能具有多方面的影响,挡板开度过大增压器效率下降。用自行研制的舌形挡板增压器在WD615.61型柴油机上进行了外特性运行,结果表明;挡板最佳开度为4°～12°;在此开度运行,油耗率下降2％～3％,扭矩和功率均提高2％～3％。     

Factors affecting the suitability of aluminium-foil trays for microwave oven heating: Comparison with plastic trays

The suitability of shallow aluminium trays (thickness of food layer 20 mm) for heating of different casseroles in microwave ovens was extensively studied. The effects of the shapes and sizes of the trays, the initial temperature and the type of oven were tested systematically for the usability of the aluminium trays, the required heating time and heating results. The results were compared with those obtained using CPET trays. It was also investigated whether incorrect placing of an aluminium tray in the oven would cause risk situations, such as arcing. It was found that, when used correctly, aluminium trays are suitable for heating of both frozen and chilled casserole products in a microwave oven. Especially in the case of frozen products, aluminium trays are more suitable than plastic trays. The post-heating quality can be improved by packaging of foods in an aluminium tray instead of a plastic tray. The shape of the trays also has an important role. Aluminium trays are better suited than plastic trays for heating in a combination oven.     

国内新型浮阀塔板评述

介绍国内近期应用较多的各种新型浮阀塔板。