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.     

Eine allgemeine Berechnungsmethode für Wärmeübertragerschaltungen

A general method for calculating any heat exchanger network is presented. As heat exchanger networks can be considered as coupled heat exchangers, that are supplied in a predetermined order, it is convenient to consider even a single heat exchanger with complicated flow patterns as a network composed of several ideally-supplied, coupled devices. The advantage of this method lies in its higher accuracy and the use of a simpler calculation formula for an ideal device model. These advantages far outweigh the disadvantages of the arduous iterative type of calculation used to establish the temperature between ideal devices. The presented method allows, for the first time, without using the iterative method, a calculation of heat exchanger networks based upon the principle of coupled matrix equations. These equations are for any given heat exchanger network simply allocated parameters, and therefore this method is especially suited for the calculation of any network modification. For the application of this method is no special software necessary. The solution of the model equations is obtained very easy and clear with mathematical standard software, e.g. Mathcad or Maple.     

Combination of coating and heat treatment processes

For a proper use of coated tools and components excellent coating properties as well as excellent substrate properties of the coating/substrate composite are necessary. A well known example is the load support of hard steel substrates for thin wear resistant coatings. Therefore coating processes must be combined with heat treatment processes of the substrates, whereby several practical processing constraints like order and compatibility of the applied treatment procedures must be considered. The combination of CVD-coating plus laser beam hardening is an example of a post coating heat treatment. Applications may be possible for large forming tools made of high alloyed tool steels, which nowadays are usually through hardened after CVD-coating. Laser beam hardening offers the possibility, to harden only the highly loaded edges of the tools. The advantages of this combination are short process time, less distortion and compressive residual stresses in the substrate surface. CVD-coatings can endure laser beam hardening with suitable parameters. The influence of CVD TiN-coated steel substrates and laser beam hardening parameters on microstructures and properties of coating/substrate compounds have been investigated. Special attention was paid to overlapping hardening zones, which may occur at the start and end points of a laser hardened track. In summary, the combination of coating and heat treatment processes show a high potential to produce coating/substrate compounds with excellent coating properties as well as excellent substrate properties.     

阿维斯塔波莱瑞特厂炉卷轧机新技术

阿维斯塔波莱瑞特厂正在进行一个现代化改造项目，以提高炉卷轧机的生产能力，达到年产100万吨。但是，由于在阿维斯塔波莱瑞特厂炉卷轧机上的现有技术已达到极限，只有通过对轧机及自动化系统进行现代化的改造才有可能提高和增强轧机的利用率和易维护性。     

Biologically active secondary metabolites of barley. IV. Hordenine production by different barley lines

Forty-three lines of barley, including ancestral (wild), landraces, Middle Eastern lines, and modern cultivars, were grown under two different sets of environmental conditions. Hordenine production in barley roots was determined at the one-leaf stage by HPLC analysis and, in two lines only, over a period of 35 days. Forty-two of the 43 lines produced significant amounts of hordenine, although there was no variation among groups. Middle Eastern lines had the highest production with 327 µg/g on a dry weight basis. Production was, however, determined more by environmental conditions during growth than by genetic factors. Hordenine production was up to seven times higher in plants grown under lower light intensities.     

Several ways to produce porous carbon monoliths by template assisted routes

Several ways to produce microporous and mesoporous carbon monoliths by template assisted synthesis routes are described. Pressed zeolite (HY) and silica powder tablets have been used as templates. Sucrose acts as a carbon precursor and as a binder between the carbon particles as well. In the case of zeolite template, the carbon porosity could be increased by additional loading of the template with ethene. Due to the balance between mechanic stability and porosity of the carbon monolith, an optimal amount of sucrose is required. The final products were characterized by low temperature nitrogen adsorption.