(119)Sn Spin-Lattice Relaxation in Alpha-SnF(2)

The temperature and magnetic field dependencies of the (119)Sn nuclear spin-lattice relaxation rate in alpha-SnF(2) indicate the presence of two relaxation mechanisms. At temperatures below 350 K, the relaxation is dominated by a nuclear spin-rotation interaction modulated by lattice vibrations, as has been seen for Pb and Tl salts. This (119)Sn relaxation pathway is less effective in SnF(2) than it is for (207)Pb, (203)Tl, and (205)Tl relaxation in some Pb and Tl salts but it is more effective than (111)Cd and (113)Cd relaxation in some Cd salts. Above 350 K, there is an additional contribution to the observed relaxation rate. The most likely candidate for this thermally activated contribution is the modulation of the (119)Sn-(19)F dipolar interaction by fluoride-ion motion

International Asteroid Warning Network Timing Campaign : 2019 XS

Peer reviewe

Konzeption und Definition von schlupfgeregelten Radsaetzen fuer ein Hochgeschwindigkeitsdrehgestell Abschlussbericht

SIGLETechnische Informationsbibliothek Hannover: AC 6128. / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Technologie-Vorentwicklungen fuer Hochleistungs-Energieversorgungssysteme. Abschlussbericht. Bd. 2

The present report covers the subjects in the field of energy supply systems of future space systems: 1) Reference is made to the requirement for developing standardized DC/DC converters. Examples are provided and investigated. 2) The Standard Box Interface design and its interaction with the devices of the energy supply system are presented. 3) The factors influencing the service life of wirings in spacecraft are investigated. Thermal and corrosive loads are defined, and production and test parameters are established for individual components. (HM)Der vorliegende Bericht behandelt 3 Themenkreise auf dem Gebiet der Energieversorgungssysteme kuenftiger Raumfahrtsysteme: 1) Es wird auf die Notwendigkeit hingewiesen, (standardisierte DC/DC Konverter zu entwickeln. Beispiele werden gegeben und untersucht. 2) Es wird der Entwurf des Standard Box Interface und sein Zusammenwirken mit den Geraeten des Energieversorgungssystems dargestellt. 3) Es werden die Einflussfaktoren auf die Lebensdauer von Verkabelungen in Raumfahrzeugen untersucht. Die thermischen und korrodierenden Lasten werden definiert und fuer einzelne Komponenten Fertigungs- und Testparameter festgelegt. (HM)Available from TIB Hannover: F94B0906+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany)DEGerman

Biosphere-atmosphere interactions

The contemporary atmosphere was created as a result of biological activity some two billion years ago. To this day, its natural composition is supported and modified, mostly through biological processes of trace gas production and destruction, while also involving physical and chemical degradation processes. The biosphere has a major influence on present environmental conditions, both on a regional and global scale. One of the bestdocumented and most important indicators of global change is the progressive increase of a number of trace gases in the atmosphere, among them carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O), all of which are of biospheric origin. There is considerable uncertainty, however, regarding the processes that determine the concentration and distribution of trace gases and aerosols in the atmosphere and the causes and consequences of atmospheric change (Andreae and Schimel 1989). To improve our understanding IGAC created an environment for multi-disciplinary collaboration among biologists, chemists, and atmospheric scientists. This was essential to develop analytical methods, to characterise ecosystems, to investigate physiological controls, to develop and validate micrometeorological theory, and to design and develop diagnostic and predictive models (Matson and Ojima 1990)

Flaecheninanspruchnahme, Bodenbelastung und Moeglichkeiten des Flaechenrueckbaus bei Eisenbahnen in Ballungsgebieten. Bd. 3 Schlussbericht

SIGLEAvailable from TIB Hannover: FR 5860(Schl3) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Flaecheninanspruchnahme, Bodenbelastung und Moeglichkeiten des Flaechenrueckbaus bei Eisenbahnen in Ballungsgebieten. Bd. 2 Schlussbericht

SIGLEAvailable from TIB Hannover: FR 5860(Schl2) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman