Recent progress and application of low level liquid scintillation counting

The use of an ultra low level liquid scintillation counter with extremely low background, MCA technique, storage and software evaluation of pulse height spectra has given very low LLD's, the possibility of - and -spectrometry to some extent and time saving optimization of counting conditions. Quick and very simple but yet accurate analytical methods could be worked out worked out for environmental measurements: Environmental levels of tritium,¹⁴C in several assimilation products,²²²Rn and²²⁶Ra in water without any sample pretreatment. Suggestions for possible further applications in environmenial monitoring and low level counting are given.     

The BTL2 process of biomass utilization entrained-flow gasification of pyrolyzed biomass slurries

Forschungszentrum Karlsruhe has developed a concept for the utilization of cereal straw and other thin-walled biomass with high ash content. The concept consists of a regional step (drying, chopping, flash-pyrolysis, and mixing) and a central one (pressurized entrained-flow gasification, gas cleaning, synthesis of fuel, and production of byproducts). The purpose of the regional plant is to prepare the biomass by minimizing its volume and producing a stable and safe storage and transport form. In the central gasifier, the pyrolysis products are converted into syngas. The syngas is tar-free and can be used for Fischer-Tropsch synthesis after gas cleaning.     

Nucleation of calcium carbonate as polymorphic crystals in the presence of lipid A-diphosphate

The well-defined structure of lipid A-diphosphate in aqueous solutions provides a way of observing the formation of calcium carbonate crystals. The crystals are either tetrahedral or rhombohedral calcite at a volume fraction of phi = 5.4 x 10 (-4) at pH 5.8 or the vaterite polymorph of CaCO(3) at a volume fraction of phi = 7.8 x 10 (-4) at pH 5.8. In both cases, nucleation, adsorption pH, and the shape-dependent template of lipid A-diphosphate control the formation of the calcite and vaterite.     

Richtungsabhängigkeit der Szintillations-Lichtausbeute von Anthrazen beim Beschüß mit α-Strahlen

The scintillation response of anthracene crystals to α-particles depends on their direction of incidence with respect to the crystal axes. The response is maximal in the direction perpendicular to the main cleaving planeab and minimal in the direction parallel to the axisa, the quotient of maximum and minimum response being about 1.55 at an energy of 5.3 MeV and increasing with decreasing energy of the α-particles. A formula based on simple assumptions is derived, which describes correctly the measured angular dependence.     

Die Bestimmung kleiner Mengen Wismut in Blei mit Hilfe von Kupferron

Zusammenfassung Durch Extraktion des Wismutkupferronates mit Chloroform bei p_H 1 läßt sich Wismut von Blei trennen. Durch Rückschütteln mit 2 n Schwefelsäure wird das Wismut aus dem Chloroformextrakt in die Schwefelsäure übergeführt und darin colorimetrisch als (BiJ₄)-Komplex bestimmt.Wir sind Herrn Prof. Dr. W. Geilmann für Anregungen und sein dauerndes förderndes Interesse, Herrn Prof. Dr. F. Strassmann für die Bereitstellung von Institutsmitteln zu großem Dank verpflichtet.     

Die quantitative Bestimmung des Stickstoffs

Ohne Zusammenfassung     

Vocal fold and ventricular fold vibration in period-doubling phonation: physiological description and aerodynamic modeling

Occurrences of period-doubling are found in human phonation, in particular for pathological and some singing phonations such as Sardinian A Tenore Bassu vocal performance. The combined vibration of the vocal folds and the ventricular folds has been observed during the production of such low pitch bass-type sound. The present study aims to characterize the physiological correlates of this acoustical production and to provide a better understanding of the physical interaction between ventricular fold vibration and vocal fold self-sustained oscillation. The vibratory properties of the vocal folds and the ventricular folds during phonation produced by a professional singer are analyzed by means of acoustical and electroglottographic signals and by synchronized glottal images obtained by high-speed cinematography. The periodic variation in glottal cycle duration and the effect of ventricular fold closing on glottal closing time are demonstrated. Using the detected glottal and ventricular areas, the aerodynamic behavior of the laryngeal system is simulated using a simplified physical modeling previously validated in vitro using a larynx replica. An estimate of the ventricular aperture extracted from the in vivo data allows a theoretical prediction of the glottal aperture. The in vivo measurements of the glottal aperture are then compared to the simulated estimations.     

Literatur

Ohne Zusammenfassung     

Über Derivate des Amidoorcins

Ohne Zusammenfassung