University of Stuttgart

About: University of Stuttgart is a education organization based out in Stuttgart, Germany. It is known for research contribution in the topics: Laser & Finite element method. The organization has 27715 authors who have published 56370 publications receiving 1363382 citations. The organization is also known as: Universität Stuttgart.

Investigation of Thermal Equilibrium Vacancies in Metals by Positron Annihilation

Abstract: The study of thermal vacancy formation in pure metals by positron annihilation and the determination of vacancy formation enthalpies is reviewed with particular emphasis to the potential of positron lifetime spectroscopy. The investigation of high-temperature vacancy migration by positron annihilation in pulse-heating experiments is outlined and first results are reported. Es wird ein Uberblick gegeben uber die Untersuchung von Leerstellen im thermischen Gleichgewicht in reinen Metallen mit Hilfe der Positronenzerstrahlung und uber die dabei gewonnenen Resultate der Leerstellenbildungsenthalpie. Hierbei wird insbesondere auf die spezifischen Moglichkeiten der Positronlebensdauerspektroskopie hingewiesen. Es wird zudem uber die Ergebnisse von Messungen der Positronenzerstrahlung in schnellen Aufheizexperimenten berichtet, mit denen die Leerstellenwanderung bei hohen Temperaturen untersucht werden kann.

Density functionals for the Yukawa electron-electron interaction

Abstract: mShort-range nonclassical electron-electron interaction is described by a density functional in a scheme that allows multideterminant wave functions. The parameter that determines the coupling with the configuration-interaction-type calculations can be chosen in a controlled manner. Results are presented for the He and the Be series using a Yukawa-type interaction. 0 1995 John Wiley & Sons, Inc.

Rapid activation of alternative second messenger pathways in olfactory cilia from rats by different odorants.

Abstract: The molecular mechanisms mediating the chemo-electrical signal transduction in olfactory receptor cells are still elusive. In this study odor induced formation of second messengers in rat olfactory cilia was monitored in a subsecond time range using a rapid kinetic device. Application of micromolar concentration of citralva induced a rapid, transient elevation of the cyclic adenosine monophosphate level, whereas the concentration of inositol trisphosphate was not affected. In contrast, pyrazine caused a rise in the concentration of inositol trisphosphate, not affecting the level of cyclic adenosine monophosphate. Analysis of the kinetic parameter for the odorant induced reaction indicated that apparently two systems are operating simultaneously. The activating effects of odorants appear to be mediated via different G-proteins. Thus, at least two different second messenger pathways appear to be involved in olfactory signal transduction.

Current topics in smectic liquid crystal research.

Abstract: Interest in the smectic liquid-crystalline state of matter received a substantial boost with the discovery by Meyer in the mid-1970s that a chiral smectic C (SmC*) phase exhibits a spontaneous electric polarization, and with the subsequent demonstration by Clark and Lagerwall of the surface-stabilized SmC* ferroelectric liquid crystal at the beginning of the 1980s. Since then, chiral smectic phases and their plethora of polar effects have dominated the research in this field, which today has reached a mature state where the first commercial microdisplay applications are now shipping in millions-per-year quantities. In this Review we discuss some of the topics of highest interest in current smectic liquid crystal research, and address application-relevant research (de Vries-type tilting transitions without defect generation and high-tilt antiferroelectric liquid crystals with perfect dark state) as well as more curiosity-driven research (the nature and origin of the chiral smectic C subphases and their intermediate frustrated states between ferro- and antiferroelectricity).