The behavior of a reverse-flow reactor was studied for the purification of polluted air by catalytic combustion. A heterogeneous one-dimensional model was extended with a heat balance for the reactor wall. An overall heat transport term is included to account for the small heat losses in radial direction. The calculations are compared to experimental data without using fit parameters. The agree...

Biofilms of natural anaerobic microbial consortia externally grown on Gas Diffusion Electrodes (GDL) in a bioreactor, were investigated within a MembraneElectrode-Assembly with respect to lifetime and electricity production upon variation of biodegradable materials with an oxygen demand of 1000mg/l as simulated waste water. A remarkable differentiation and plasticity of the films is observed, t...

At present in Germany there are 61 plants for Mechanical(-Biological) Treatment (M(B)T) of residual wastes with a total capacity of about 6.4 million tons per year. They can be classified in four process concepts: material stream separation, mechanical-biological stabilization (with a biological drying process), mechanical-physical stabilization (with a thermal drying process) and mechanical(-b...

A method for measuring the major urinary 17-ketosteroid fractions has been developed. This method includes extraction of the conjugated steroids, hydrolysis, extraction of the free steroids, purification of the extraction, and quantitation of the steroids contained in the purified extract by gas-liquid chromatography. Data are presented on the excretion of androsterone, etiocholanolone, and deh...

The intrinsic defects in reduced graphene oxide (rGO) formed during reduction processes can act as nanopores, making rGO a promising ultrathin-film membrane candidate for separations. To assess the potential of rGO for such applications, molecular dynamics techniques are employed to understand the defect formation in rGO and their separation performance in water desalination and natural gas pur...

The causes and the prevention of carbon steel corrosion in amine systems are reviewed. The corrosive agents are acid gases, oxygen, heat stable salts, amine degradation products, and, in refineries, gas contaminants such as ammonia and hydrogen cyanide. Corrosion mechanisms are provided for carbon steel exposed to amine solutions and for amine regenerator overhead systems containing aqueous con...

We report the determination of 3-methoxy-4.-hydroxyphenylpyruvic acid, 3,4-dihydroxyphenylmandelic acid, and 3,4-dihydroxyphenylethylene glycol in urine, by use of gas chromatography/mass spectrometry in combination with a simple purification method and deuterium-labeled internal standards. Normal excretion values in terms of creatinine, expressed as a function of age, are given, together with ...

We describe a ratio gas-chromatographic method for determination of cortisol production rate by measuring the isotope dilution of urinary cortisol metabolites. The method was calibrated by analyzing [3H]tetrahydrocortisol and [3H]tetrahydrocortisone of known specific activities. Results are reasonably well reproducible, the coefficients of variation ranging from 8-15% of allotetrahydrocortisol/...

Combined gas chromatography-mass spectrometry has been used to identify indole-3-methanol in a purified buffer extract from etiolated seedlings of Pinus sylvestris L. Quantitative estimates obtained by high performance liquid chromatography with fluorescence detection, corrected for losses occurring during purification, indicated that etiolated seedlings of P. sylvestris contained 19.7 +/- 1.4 ...