DECHEMA

About: DECHEMA is a nonprofit organization based out in Frankfurt am Main, Germany. It is known for research contribution in the topics: Corrosion & Oxide. The organization has 756 authors who have published 1307 publications receiving 25693 citations.

Resistance of Coatings for Boiler Components of Waste-to-Energy Plants to Salt Melts Containing Copper Compounds

Abstract: The accelerating effect of heavy metal compounds on the corrosive attack of boiler components like superheaters poses a severe problem in modern waste-to-energy plants (WTPs). Coatings are a possible solution to protect cheap, low alloyed steel substrates from heavy metal chloride and sulfate salts, which have a relatively low melting point. These salts dissolve many alloys, and therefore often are the limiting factor as far as the lifetime of superheater tubes is concerned. In this work the corrosion performance under artificial salt deposits of different coatings, manufactured by overlay welding, thermal spraying of self-fluxing as well as conventional systems was investigated. The results of our studies clearly demonstrate the importance of alloying elements such as molybdenum or silicon. Additionally, the coatings have to be dense and of a certain thickness in order to resist the corrosive attack under these severe conditions.

Detection of hydrogen in hidden and spalled layers of turbine blade coatings

Abstract: Gas turbine blades are covered with an outer ceramic top coat and an inner metallic bond coat, namely a thermal barrier coating system (TBC). The stability of the TBC is strongly influenced by the thermally growing oxide (TGO) which forms between the top and bond coat during turbine operation. This work is focused on the role of hydrogen in the adhesion of the top coat after oxidation at 1100 °C in dry and wet air at various time steps between 75 and 1150 h. To obtain the essential hydrogen information from the TGO the nuclear reaction 1H(15N, αγ)12C is used with a unique scattering chamber (SDIBA). This equipment combines the defined exfoliation of the top coat by using a 4-points bending mechanism followed by IBA. This allows the determination of hydrogen concentration depth profiles at the TGO and first results are presented.

Potential-controlled chromatography for the separation of amino acids and peptides

Abstract: Potential-controlled chromatography is introduced as a new technique for the separation of amino acids and peptides. The principle of potential-controlled chromatography depends on the use of electrically conductive material as the stationary phase of the chromatographic column. Thus from an electrochemical point of view the packed column can be regarded as a packed-bed electrode. The electrical potential of this stationary phase can be controlled by a potentiostat. The separation of amino acid and peptide molecules during their migration through the column depends on their own electric charge on the one hand and on the electrical potential of the stationary phase on the other. The chromatographic separation of some amino acids could be demonstrated.

Fermentation process for preparing perfuming and flavouring agents

Abstract: The glycol has a molecular weight of 1200-1800. The amino acid used is phenylalanine in a large quantity, which separates in the aqueous phase by bio converting reaction. Carbon source and vitamins for cell growth and minerals are added to the growth medium. The ratio of glycol is 1:1. The process further comprises separating the emulsion by constant agitating and centrifuging.

Safe biotechnology (4). Recommendations for safety levels for biotechnological operations with microorganisms that cause diseases in plants.

Abstract: The Working Party on Safety in Biotechnology of the European Federation of Biotechnology has proposed a classification of microorganisms that cause diseases in plants. In this paper appropriate safety levels are proposed for these classes of microorganisms in order to ensure that research, development and industrial fermentation work with plant pathogens will limit the risk of outbreaks of diseases in crops that could result from work with such microorganisms when they are cultivated in laboratories, glasshouses and biotechnology installations.