Modelling of thermal desorption of active coke loaded with sulphuric acid and ammonium sulphate

The BF-Uhde-Mitsui Process uses active coke for SO₂- and NO_x-removal from flue gases in the temperature range between 100 and 190 °C, Experimental methods of thermal regeneration were applied to the evaluation of the state of the adsorbent after use in flue gas cleaning and of the parameters for disrober design. A reaction model was derived from experiments carried out in differential and back-mix reactors. The parameters were evaluated by adaptation of the model to the adsorption spectra. The model was successfully applied to the regeneration of active coke in a fluidized bed reactor.     

Serviceorientierte Architektur

Zusammenfassung Das Schlagwort der serviceorientierten Architektur (SOA) beherrscht gegenw?rtig die Diskussion um die Gestaltung unternehmensweiter Anwendungslandschaften. Dabei wird SOA h?ufig gleichgesetzt mit der Verwendung von Web Services und deren assoziierten Technologien. SOA sollte aber als fachliches Architekturmuster interpretiert werden, das technologieunabh?ngig angewendet werden kann.     

Advanced glycation endproducts stimulate the MAP-kinase pathway in tubulus cell line LLC-PK1

Advanced glycation endproducts (AGEs) are suggested to play an important role in diabetic nephropathy. They induce specific cellular responses such as the release of cytokines in different cell lines. The effect of AGEs on signal transduction pathways was investigated in the renal tubulus cell line LLC-PK1. Using a serine-phosphate-specific antibody AGE-induced cellular responses associated with phosphorylation/dephosphorylation events were demonstrated. In particular, the p42MAP kinase and its downstream target, the AP-1 complex, are shown to be activated by AGE-BSA but not by BSA. In contrast, only partial phosphorylation is observed for the p70S6-kinase. Thus, AGEs appear to induce specific signal transduction pathways.     

Impact strength of nylon 6 and 66 in the dry and moist states

The impact strength of nylon was determined by the modified Charpy test with double-V notches described in DIN 53753, because it cannot be reliably assessed by the notched Charpy and Izod tests. This test was adjusted to obtain a sensitive, accurate and reproducible method for the determination of impact strength in the dry and moist states. In the light of the criterion thus gained, it is shown that the dry “as-moulded” state is unstable and that the impact strength decreases exponentially with storage timE. Therefore, comparison tests are not valid unless the measurements are performed within a restricted period of time after the specimens had been demoulded. If the age of the specimens is unknown, a reproducible “as-moulded” state can be regenerated by an annealing procedure. The state of “conventional” moisture content that is taken as a reference for comparing data obtained on moist nylon is the equilibrium moisture content in a standard laboratory atmosphere. Various methods are discussed for attaining this state rapidly by accelerated conditioning. An atmosphere of 70‡ C and 62% relative humidity allows accurate adjustment to the “conventional” moisture content but does not result in a stable reference state; for instance, the impact strength decreases within several weeks after conditioning.     

Investigation on topology of platelet-like effect-pigments in automotive surface-coatings

To investigate the interrelation between the orientation of platelet-like effect pigments in surface coatings and their coloristic properties, two metallic basecoat systems (Al, Al–blue mixture) have been deliberately blended with a colorless organic extender (nearly spherical), that allows for a systematic disturbance of the alignment of the pigment particles. As methods of investigation, goniospectrophotometry, confocal Laser-scanning microscopy, and microscopic image analysis of basecoat cross-cuts have been employed. From the reflection-indicatrix, the variation of colorimetrical quantities with deorientation agent content have been derived in a direct way. Moreover, the phase-function of the Al-pigments has been determined from fitting the equation of radiative transfer to the experimental reflection surfaces. The phase-function provides information about the distribution function of polar angles of the pigment particles in 3-dimensional space. The distribution function of the orientation angle of Al-pigments in cross-cuts of basecoats as obtained from microscopic image analysis can be satisfactorily explained within a simulation model, that allows for a calculation of the distribution function for when assuming the individual distribution functions for polar- and azimuthal-angle of the surface normal of the pigment particles, taking fully into account induced axes of anisotropy.     

Realization of true-time delay lines based on acoustooptics

A true-time optical delay line for short radiofrequency (RF) pulses using path length dispersion is proposed. It is an optical implementation of the linear phase-shift theorem of the Fourier transformation. Acoustooptic signal processing is used for conversion into the optical frequency domain and for spatial Fourier decomposition of the pulse. The processing of the pulse is obtained by differentially phase shifting the particular frequency components, followed by a heterodyne reconversion into the RF domain. The optical system is intended to be used for delaying, but also for shaping and filtering of RF pulses, mainly in phased array radar antennas. Theoretical analysis of the system principle is given together with experimental results, demonstrating 2-μs time delay of 0.5-μs-long pulses with maximum optical phase shift of 1.2π. A detailed theoretical and experimental bandwidth analysis is carried out, pointing to the main technical problems and their solutions     

CO Oxidation on Pd(100) Versus PdO(101)-(\sqrt{5}\times \sqrt{5})R27^{\circ}: First-Principles Kinetic Phase Diagrams and Bistability Conditions

We present first-principles kinetic Monte Carlo (1p-kMC) simulations addressing the CO oxidation reaction at Pd(100) for gas-phase conditions ranging from ultra-high vacuum to ambient pressures and elevated temperatures. For the latter technologically relevant regime there is a long-standing debate regarding the nature of the active surface. The pristine metallic surface, an ultra-thin $(\sqrt{5}\times \sqrt{5})R27^{\circ}$ PdO(101) surface oxide, and thicker oxide layers have each been suggested as the active state. We investigate these hypotheses with 1p-kMC simulations focusing on either the Pd(100) surface or the PdO(101) surface oxide and intriguingly obtain a range of (T, p)-conditions where both terminations appear metastable. The predicted bistability regime nicely ties in with oscillatory behavior reported experimentally by Hendriksen et al. (Catal Today 105:234, 2005). Within this regime we find that both surface terminations exhibit very similar intrinsic reactivity, which puts doubts on attempts to assign the catalytic function to just one active state.