Türme unter Glocken‐ und Erdbebenlast nach alter und neuer DIN 4178 und 4149

Towers under Bell and Earthquake Loads according to the old and new DIN 4178 and 4149 Due to their slenderness and their function bell towers are especially exposed to dynamic loads. These loads are the dynamic loads due to the ringing of the bells (DIN 4178 of 1978) and earthquake loads (DIN 4149 of 1981). The two for these load cases relevant codes have been updated to the current technical state of knowledge and have been published in April 2005. In this article the differences between the old and new versions of the codes are explained by two selected examples. The consequences of rehabilitation measures of the bells are also considered. It was found that the new versions of the codes lead to higher loads of the towers. To design new towers and to investigate existing ones it is therefore required to use the updated versions of the codes to obtain reliable results.     

Erhöhung der Ermüdungsfestigkeit von geschweißten höherfesten Baustählen durch Anwendung von Nachbehandlungsverfahren

Enhancement of the fatigue strength of welded high strength steels by application of post‐weld treatment methods. According to the present state of the art welded high strength steels have the same fatigue strength as welded standard steels. For an effective application of high strength steels in constructions subjected to fatigue are therefore additional efforts necessary in order to improve the fatigue strength, for example by the application of post‐weld treatment methods. However up to the present it is not possible to apply the positive effects of these methods in the fatigue design of steel structures. This paper shows first results of a research project, that examines the effectiveness of the post‐weld treatment method TIG‐dressing and the relatively new method “Ultrasonic Impact Treatment” (UIT) for the improvement of fatigue strength of welded high strength steels.     

Insights into potential cellular mechanisms of cisplatin nephrotoxicity and their clinical application

Cisplatin preferentially accumulates in cells of the S3 segment of the renal proximal tubule and is toxified intracellularly by hydration. The earliest manifestation of toxicity is inhibition of protein synthesis. GSH depletion is another important mechanism causing CP toxicity. Intracellular binding to SH groups leads to GSH depletion, resulting in lipid peroxidation and eventually mitochondrial damage. New measures to prevent GSH depletion and scavenge intracellular free oxygen radicals have been tried in clinical studies. Promising results indicate that cisplatin nephrotoxicity can be further reduced in the future.     

Does safety science fulfill the requirements of modern technical systems?

Since the idea of safety science was first conceived, technical systems have grown larger and increasingly complex, thus causing a pronounced impact on the complexity of required safety analyses and risk calculations. The author emphasizes his point of view that the physical risk definition provides the most appropriate concept for engineers when it comes to planning including risk cadastres. In order to avoid human errors, he pleads for the consideration of human factors in the early design phase and for interdisciplinary cooperation. © 2003 Wiley Periodicals, Inc. Hum Factors Man 13: 223–230, 2003.     

Alpha-galactosidase of the marine bacterium Pseudoalteromonas sp. KMM 701

An alpha-galactosidase that inactivates the group specificity of B erythrocytes (group III) of human blood and does not affect A erythrocytes (group II) was isolated from the marine bacterium Pseudoalteromonas sp. KMM 701. The enzyme preparation did not contain lectin, hemolytic, sialidase, endoglycanase, or glycosidase activities. The enzyme is stable at 20 degreesC for 24 h, has pH optimum for catalysis within the range of 6.7-7.7, and is stable to high concentrations of NaCl. It is 4-fold more efficient than the alpha-galactosidase from green coffee beans. At pH 7.0 the Km for p-nitrophenyl-alpha-D-galactopyranoside is 0.29 mM. The molecular weight of the enzyme determined by gel-filtration is 195 +/- 5 kD. The alpha-galactosidase is denatured by urea and guanidine hydrochloride. Its activity does not depend on the presence of metal ions. It contains a sulfhydryl group essential for its catalytic activity.     

On heat conduction between laser-heated nanoparticles and a surrounding gas

Uncertainties in modeling heat conduction in connection with the application of laser-induced incandescence (LII) to primary particle sizing are discussed. Comparing two models widely used in this context, namely those of Fuchs [(1963). On the stationary charge distribution on aerosol particles in a bipolar ionic atmosphere. Pure and Applied Geophysics 56, 185–193] and McCoy/Cha [(1974). Transport phenomena in the rarefied gas transition regime. Chemical Engineering Science 29, 381–388], it is demonstrated that arising differences may be accounted for by the choice of a proper “effective” thermal accommodation coefficient _eff. In experiments on a large number of carbon blacks an overally good agreement between LII results and specified values for particle sizes based on electron-microscopy (EM) is obtained with a choice of _eff=0.25 (based on the McCoy/Cha-model). As aggregate size is expected to influence heat transfer from primary particles, the experimental data are analyzed by a model for an effective heat transfer surface of fractal aggregates. Based on values for the average number of primary particles per aggregate as derived from photocentrifuge measurements the data yield an extrapolated value for the physical accommodation coefficient for isolated particles of ₁=0.43.     

Laboratory evaluation of plastic pipe from a gas service field-test installation

This article presents the background and results of the first two-year interval test of a projected 10 or more years field gas service test of various types of plastic pipes. The study is part of a program to establish the suitability of plastic pipes for gas distribution uses. A number of short-term laboratory tests were used to characterize the condition of the pipe after the first two-year exposure period some, like the cursh test, are recognized and accepted methods; others, like the ring-tensile, tensile-impact, and the tear-propagation tests were developed or modified for this stdy. The results show that comparatively little change had taken place in this test period; the possible exception being in the ductility of two kinds of pipe subsequent evaluation should confirm or deny this behavior.     

Competitive and sustainable manufacturing by means of ultra-efficient factories in urban surroundings

The rapid growth of the world population, the finiteness of resources on our planet Earth and the ongoing tendency towards urbanisation result in the need to question our actions and economic activities, also for industrial enterprises. A paradigm shift to decouple growth and resource utilisation is needed. By means of ultra-efficiency, factories are targeted, whose positive impact to their surrounding is optimised instead of only minimising negative influences. In the contribution, the concept of ultra-efficient factories and first tools for their implementation are introduced. Therefore, the term ultra-efficient factory is defined based on the state of the art. On this definition, spheres of activity for ultra-efficient factories under consideration of urban surroundings are determined. For the spheres of activity, criteria to assess the according maturity of companies are identified and aggregated into a comprehensive maturity model. The maturity model enables the determination of potentials for advancements of companies. To support the industrial application of the theoretic work, industrial best practices are determined and a visual tool is developed.     

Ordered polycrystalline thin films for high performance CdTe/CdS solar cells

An ordered polycrystalline approach is proposed to overcome fundamental problems associated with random polycrystalline thin films, namely grain boundaries and inhomogeneity. The approach consists of two main steps: (1) the deposition of a patterned growth mask and (2) the selective-area deposition of the ordered polycrystals. The ordered polycrystalline approach was investigated using the CdTe/CdS material system. Experimental results demonstrate that SiO₂ and Si₃N₄ are effective growth masks and that temperature is a dominant parameter for selective-area deposition. PL and XRD characterization indicates that the ordered polycrystalline technique has the potential for improving the crystal quality and order of polycrystalline CdTe thin films. The approach appears to be fairly general and could be applied to other material systems.