The effect of pre-warming on performance during simulated firefighting exercise

This study examined the effect of active pre-warming on speed and quality of performance during simulated firefighting exercise. Twelve male firefighters performed two trials in counterbalanced order. They were either pre-warmed by 20-min cycling at 1.5 Watt kg⁻¹ body mass (WARM) or remained thermoneutral (CON) prior to a simulated firefighting activity. After the pre-warming, gastrointestinal temperature (P < 0.001), skin temperature (P = 0.002), and heart rate (P < 0.001) were higher in WARM than in CON. During the firefighting activity, rating of perceived exertion, thermal sensation and discomfort were higher for WARM than for CON. Finish time of the firefighting activity was similar, but the last task of the activity was completed slower in WARM than in CON (P = 0.04). In WARM, self-reported performance quality was lower than in CON (P = 0.04). It is concluded that pre-warming reduces the speed during the last part of simulated firefighting activity and reduces self-reported quality of performance.     

The effect of fibre-matrix interactions on structure and property changes during the fabrication of unidirectional carbon/carbon composites

This paper reports the systematic characterisation of changes in the structure and properties of a series of unidirectional carbon-carbon composites at key stages of processing. The composites were fabricated from PAN-based carbon fibres (surface treated and untreated) and two carbon matrix systems (graphitising and non-graphitising). The effects of matrix shrinkage, together with thermal expansion mismatch and interfacial bonding, established the composite structure and hence the composite properties. The morphology and interconnectivity of the shrinkage cracks, the strength and nature of the fibre-matrix interfacial interaction and the development of matrix texture were identified as key structural features. These features were characterised and their effect on subsequent processing stages (densification) and composite properties was determined.     

CFRP压力容器固化成型过程中边界条件的确定

文中应用总放热系数等效考虑了CFRP压力容器固化过程中热压釜辐射与对流边界条件。将有限元法引入瞬态热传导的反问题，根据试验测量的温度曲线，并结合最优化理论确定合理的热压釜热边界条件。结果表明：平板试验得到了总放热系数序列，其计算温度与测试温度的最大温差为0．147℃。由此，可以将得到的总放热系数序列作为CFRP压力容器固化成型过程的等效热边界条件，为其固化成型的数值模拟提供计算基础。     

Phenol adsorption on porous and non-porous carbons

Phenol physisorption on a series of porous and non-porous amorphous carbons was studied at 298 K. Grand Canonical Monte Carlo computer simulations were performed to simulate phenol adsorption from the gas phase. Phenol is adsorbed in a solid-like state within the pores and there is no well-developed multilayer regime. The ‘t’ plot method was adapted to phenol adsorption and the results obtained are in agreement with the model solids employed. The simulated adsorption isotherms were compared with experimental results obtained for adsorption from aqueous solutions of phenol. BET surface areas were calculated. Other characteristics of the adsorption system analyzed were: adsorption energy distribution functions, density profiles, distribution of molecules according to gas-solid energy, and local isotherms.     

EXTERNAL FLUID HEATING OF A POROUS ED

This work deals with the thermal analysis of externally heated porous beds of finite length. A one dimensional model was developed that includes conduction and storage in both the fluid and bed, convective exchange between the fluid and bed, and the effect of adsorption/desorption in the bed. This model results in two coupled differential equations for the fluid and bed temperatures as functions of four independent dimensionless parameters. These equations were solved numerically using finite difference approximations. A truncation error analysis was carried out to maintain an accurate solution. The method of normalization is such that the results of this analysis are of use in bed design when the breakthrough characteristics in finite length beds are of interest. A method to measure bed thermal performance is defined and a means to optimize bed thermal performance is presented. An experiment was conducted to validate the numerically obtained results. A comparison of numerical to experimental results is presented     

大型管壳式换热器管-管板连接的可靠性措施

从材料性能、管孔的结构及加工要求、管与管板的连接形式等影响换热器管与管板连接接头强度的因素出发 ,结合乙烯大型换热器E EA12 3F的制造提出了管与管板连接接头的可靠性措施     

INNOVATIVE APPLICATIONS OF IONIC LIQUIDS AS “GREEN” ENGINEERING LIQUIDS

Over the past decade, ionic liquids (ILs) have become one of the fastest growing “green” media for chemists and engineers due to their superb physicochemical properties. The applications of these remarkable salts in reactions and extraction processes have been extensively investigated and reviewed. This review, however, highlights recent advances of ILs as versatile “green” engineering liquids in a variety of industrial applications including heat transfer fluids, azeotrope-breaking liquids, lubricants, electrolytes, liquid crystals, supported IL membranes, plasticizers, and more. This review is not intended to be comprehensive, but rather to discuss the potentials of ILs for diverse industrial applications.     

单填料函滑动管板式换热器密封结构的设计

自行设计了一台单填料函滑动管板式换热器代替进口设备，运转良好。本文着重介绍该设备密封结构的设计。     

管壳式换热器管束振动分析及防振措施

针对管壳式换热器常见的振动破坏形式 ,全面分析了管束振动的机理 ,并提出了相应的抗振措施     

脱乙烷系统参数优化

吉化300kt/a乙烯装置脱乙烷系统采用德国Linde公司双塔双压前脱乙烷技术，自1996年开始以来，运行良好，通过工程技术人员近两年的探索实践，对其工艺参数做了较大的优化调整，取得了较好的经济效益。