Synthesis and Characterization of SiO_2 Coated γ-Fe_2O_3 Nanocomposite Powder for Hyperthermic Application

SiO2 coated γ-Fe2O3 nanocomposite powder has been successfully synthesized by chemical vapor condensation process and its feasibility on hyperthermic application was investigated in this study. The power loss of SiO2 coated γ-Fe2O3 nanocomposite powder which means the magnetic heating effect under alternative magnetic field was much higher than the single phase γ-Fe2O3 nano powder due to the very fine size under 20 nm and well dispersion in biologically compatible SiO2 matrix. The superparamagnetism and hyperthermic property of SiO2 coated γ-Fe2O3 nanocomposite powder were discussed in terms of microstructural development in this study.     

Strömungsmechanische und akustische Untersuchungen an Koaxialstrahlen unterschiedlicher Profilierung

Ohne Zusammenfassung     

STUDIES OF STEAM DRYING IN A FLUIDIZED BED

In general, drying processes are described by the quantity of air humidity of the exiting gases. This approach is not possible however by the drying medium of water in steam drying, since the air humidity naturally possesses a constant value of 100%. This paper presents a model which represents the drying processes on the basis of the observation of temperature profiles of the material and energetic balancing of all components involved as well as the wall of the apparatus. The modeling differentiates three intervals: the condensation phase, the 1st drying period and the 2nd drying period. In addition, a validation of the model on the basis of experiments in an experimental plant DN100 belonging to the university is dealt with. The satisfying concurrence of the theoretical and practical results shows that, with the help of the theoretical model, discontinuous steam drying processes can be theoretically described with sufficient accuracy.     

Arsenic burden among children in industrial areas of eastern Germany

Several accounts of specific language impairment (SLI) in children have appeared in the recent literature. One of the most explicit is that of Locke. The purpose of the present investigation was to evaluate some of the details of Locke's proposal. In the first of two studies, it was found that children with SLI who were limited to single-word utterances showed deficits in their lexical comprehension. In the second study, a number of children with SLI who had reached the grammatical stage of development showed age-appropriate levels of lexical comprehension. Although the first of these findings was in keeping with Locke's account, the second was not. Additional provisions for this proposal are suggested.     

Instandhaltungsgerechte Gestaltung technischer Anlagen

Maintenance-favourable design of industrial plant . A study by the German Maintenance Committee proves that maintenance costs in the Federal Republic in 1977 amounted to 123 × 10⁹ DM, of which 30 × 10⁹ DM were accounted for by manufacturing industry and more than 5 × 10⁹ DM by the chemical industry. Over 50% of subsequent damage costs are caused in the planning and manufacture phase. These sources of damage become manifest during later use and damage and secondary damage costs are incurred by the user. An appeal therefore goes out to plant manufacturers, users, and maintenance staff to cooperate in reducing the sources of damage. An important basis for such a move is the collection and exchange of data, utilization of data pools, and systematic analysis for determination of weak points at the planning and construction stage. Since maintenance costs, as one of the four operational cost factors (material, personnel, energy, and maintenance costs), show an increasing tendency with progressive automation there is a continuiing need for a cost or profit center for plant engineering or planned maintenance.     

Ein allgemein anwendbares,zweidimensionales Verfahren zur Berechnung von stationären und instationären Ausgleichsvorgängen unter Berücksichtigung nichtkonstanter Stoffwerte

Beschreibung von numerischen Verfahren zur Berechnung von stationären und instationären Vorgängen wie Wärmeleitung, Stoffdiffusion, elektrischer Stromfluß und Impulsaustausch. Hinweise auf die Anwendbarkeit, Vor- und Nachteile dieser Verfahren. Beschreibung eines allgemein anwendbaren zweidimensionalen Rechenprogramms für nichtlineare Ausgleichsprozesse, dargestellt am Beispiel der Berechnung eines Temperaturfeldes. Anwendung des Programms auf die Berechnung der Ausbreitung turbulenter Gasstrahlen aus einem Registerbrenner und des Temperaturfeldes bei der Tragschienenkühlung eines Verzinkungsofens.     

Einfluß des Umwandlungsgefüges auf das Zeitstandverhalten des Stahles 10 CrMo 9 10

Auswertung von Zeitstandversuchen bei 500, 550 und 600 °C bis rd. 20000 h Dauer an einer Schmelze des Stahles 10 CrMo 9 10 mit 0,11% C, 2,30% Cr und 1,03% Mo in vier Wärmebehandlungszuständen. Untersuchung des Gefüges im Ausgangszustand und nach Zeitstandbeanspruchung. Zusammenhang zwischen Zeitstandfestigkeit und Ausscheidungsverhalten.