Aluminium Foam Sandwich (AFS) Ready for Market Introduction

A novel production process for aluminium foam sandwich panels (AFS) is described. As an example for a serial application of AFS a support for a mobile telescope arm on a small lorry is presented and discussed.     

Modification of the water oxidizing complex in leaves of the dgd1 mutant of Arabidopsis thaliana deficient in the galactolipid digalactosyldiacylglycerol

The primary biochemical defect in the genetically well characterized dgd1 mutant of Arabidopsis thaliana causes a 90% reduction in the relative amount of the galactolipid digalactosyldiacylglycerol (DGDG). To study the effect of this DGDG deficiency on photosystem II (PS II), time-resolved transients of laser-flash-induced changes of the relative fluorescence quantum yield Fvar,rel(t) were measured in whole leaves from wild-type and the dgd1 mutant. The results obtained reveal (i) in untreated leaves the decay kinetics of Fvar, rel(t) reflecting QA.- reoxidation by endogenous plastoquinone are very similar in wild-type and the dgd1 mutant at room temperature, (ii) the Arrhenius plot of the temperature dependence of electron transfer from QA.- to QB exhibits a break point at about 19 degrees C in wild-type and about 12 degrees C in the dgd1 mutant, (iii) in leaves treated with DCMU the slow reoxidation of QA.- by the PS II donor side is blocked to a much higher extent in the dgd1 mutant (about 50%) compared to wild-type (about 10%), and iv) the normalized amplitude of Fvar,rel(t = 1 micros) reflecting the percentage of fast P680.+ reduction by YZ exhibits a characteristic period four oscillation in wild-type while this feature is strongly damped in the dgd1 mutant. Presumably, the severe DGDG deficiency is causing the thermal down shift of a lipid phase transition that affects the QA.- reoxidation by QB. Most strikingly, the properties of the WOC are modified as a result of reduced DGDG content. Thus, the lipid DGDG appears to be of structural relevance for the WOC.     

Macrophage function and host resistance against infection with Toxoplasma gondii

The role of macrophages on the course of an infection with Toxoplasma gondii has been examined. Stimulation of macrophage function by killed Bordetella pertussis cells did not show any beneficial effect as an increased susceptibility became apparent. The functional blockade of macrophages by dextran sulfate or carbon particles did not result in a higher susceptibility of mice to the lethal primary infection with T. gondii. Thus in vivo macrophages apparently do not play an essential role as effector cells as they do in infections with other obligate intracellular infective organisms such as Listeria monocytogenes. The spleen is apparently of crucial importance for resistance against T. gondii infection, since death occurred earlier in splenectomized mice than in control animals.     

Untersuchungen über die physikalischen Vorgänge bei der Elektrofilterung

Ohne Zusammenfassung     

Das dynamische Kennlinienfeld des schützengesteuerten Asynchron-Schleifringläufermotors

Einfluß des schützengesteuerten Asynchron-Schleifringläufermotors auf die Momentenverläufe in den Triebwerken von Hüttenkranen. Beschreibung eines Motorprüfstandes zur Ermittlung der Luftspaltmoment-Zeit-Funktionen während instationärer Betriebsphasen. Übertragungsfunktion zwischen dem in der Motorwelle gemessenen und dem im Luftspalt herrschenden Drehmoment. Gegenüberstellung des bekannten stationären Drehmoment-Drehzahl-Kennlinienfeldes und eines aus Prüfstandmessungen hergeleiteten Feldes dynamischer Steuerkurven. Folgerungen für die Abschätzung der motorseitig abgegebenen Drehmomentenhöchstwerte. Hinweise auf die zur beanspruchungsgerechten Dimensionierung von Triebwerksbauteilen notwendige Schwingungsbetrachtung der auszulegenden Systeme.     

Prospects of gas supplies to the European market until 2030—results from the simulation model EUGAS

Natural gas is the fossil energy fuel estimated to have the highest demand growth rates in Europe during the first three decades in the 21st century. Hence, substantial new gas supplies are needed for the European energy markets in the coming years. In this article, future European gas supplies are quantitatively projected by using the long-term optimisation model EUGAS, developed at the Institute of Energy Economics at the University of Cologne in year 2000. The model simulations show no discernible physical gas scarcity at least for the next 20–30 years in Europe, but significant investments in new production and transportation facilities will be necessary during this time period. Diversification of supplies and political considerations will have significant impacts on the development of new gas resources and on investments needed. Nevertheless, the unit costs of supplies are moderate, and only minor cost driven price increases have to be expected during the coming decades—at least as long as future gas demand growth does not significantly exceed current projections.     

Aqueous pore structure and proton dynamics in solvated Nafion membranes

Molecular dynamics computer simulations of water/Nafion mixtures using an all-atom model were performed as a function of temperature and humidity. The simulations are aimed at investigating processes and structures on the picosecond to nanosecond time scale in the nano-phase-separated material with its technological relevance for low temperature fuel cells. Characteristic differences in aqueous pore structure were observed for systems whose water content was varied between 5 and 10 molecules per acid group in the polymer. As expected, proton transport increases significantly with increasing humidity, its mechanism is dominated by the Grotthus structural diffusion mechanism in accordance with earlier studies in simplified model pores. On the simulated time scale no unambiguous conclusions on the role of polymer dynamics for the transport in dry membranes can be drawn.     

Isolation of Listeria monocytogenes in slaughter animals and bats of Togo (West Africa)

Listeria monocytogenes was isolated from the intestinal lymph nodes of 8 out of 342 apparently healthy slaughter animals at the municipal abattoir in Lome (Togo) and from the faeces of 3 out of 236 bats. Except two strains of serovar 4b isolated from bats, all the nine others belonged to serovar 1/2a. The positive findings of slaughter animals were made from the carcasses of 2 pigs, 5 little ruminants and 1 cattle. The findings are discussed in the light of present knowledge on the occurrence of L. monocytogenes in some species of animals and its implications for the human being.