Einflüsse von NFC-Smartphones auf das RFID- Bibliothekssystem : eine Analyse des Bedrohungspotentials durch NFC-Smartphones und Beschreibung von möglichen Gegenmaßnahmen

Dieses Kapitel soll einen Einstieg in die Problematik von NFC-Einfl üssen auf Bibliothekssysteme geben. Dazu werden die Eigenschaften der beteiligten Systemkomponenten kurz erklärt. Anschließend werden zwei Hauptangriffsszenarien mit den Auswirkungen für eine Bibliothek beschrieben. Des Weiteren werden mögliche Wege aufgezeigt, wie solche Angriffe verhindert werden können und was bei Einsatz solcher Lösungen beachtet werden muss

NUMERICAL STUDY OF BUBBLE HYDRODYNAMICS FOR GAS-SOLID FLUIDIZED BEDS WITH AND WITHOUT HORIZONTAL TUBES

The paper deals with numerical simulations using the Eulerian-Eulerian Two Fluid Model (TFM) of 2D gas-solid bubbling fluidized beds with and without immersed horizontal tubes. The bubble diameters and rise velocities obtained from the simulations presented good agreement when compared with experiments and correlations available in the literature. The presence of horizontal tubes inside the bed was found to be the main cause of bubble breakup, which eventually reduce the bubble diameter and rise velocity

NUMERICAL STUDY OF BUBBLING FLUIDIZED BEDS: INFLUENCE OF IMMERSED TUBES, EXTRACTION METHODS AND AVERAGING PERIODS

Numerical simulations using the Two Fluid Model were performed for 2D gas-solid fluidized beds with and without immersed horizontal tubes. The results were compared with experimental data available in the literature. Different techniques of extracting the time-averaged values of pressure drop and bed expansion and the influence of averaging time were investigated. Furthermore, the influence of tubes on the solids motion and distribution were studied

Getting magnetocaloric materials into good shape: Cold-working of La(Fe, Co, Si)13 by powder-in-tube-processing

The powder-in-tube (PIT) technology was applied to La(Fe, Co, Si)13 powder cladded by a thin seamless austenitic steel jacket. Wires appear to be promising in the search for alternative regenerator geometries, since they offer various possibilities of arrangements allowing to optimise heat transfer and pressure loss within the boundaries set by parallel plate and sphere beds. Here, pre-alloyed La(Fe, Co, Si)13 powder was filled in a AISI 316L austenitic steel tube and swaged to wires with an outer diameter of 1 mm. By mechanical deformation, the steel jacket thickness was reduced to about 100 μm surrounding the magnetocaloric core. A post-annealing of only 10 min at 1050 °C is sufficient to form the magnetocaloric NaZn13-type phase resulting in an entropy change close to the value of a pure reference sample. The presented technology is not limited to La(Fe, Co, Si)13/steel combination but can be extended to material pairs involving wire core materials with a first order transition, such as Fe2P-type or Heusler alloys

Neue lichtstarke Anordnungen für photochemische Reaktionen

New arrangements for photochemical reactions of substances with active absorption especially in the short wavelength region of the ultraviolet spectrum are described. As light sources are used water cooled high pressure mercury lamps and new xenon arc lamps. The water cooled annual cylindrical vessels containing the photochemical substances are made of fused quartz or special glasses with adapted transmission in the ultraviolet spectrum. They surround completely the light sources which can be exchanged very easily. In this way energy losses of u.v.-radiation and heating of the photochemical substances are avoided, so that best efficiencies can be reached in less than the tenth of the time needed before. This could be confirmed in various photochemical reactions i. e. with vitamin D2 and chlorination of benzene