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.

Identification of a Caldariomyces fumago mutant secreting an inactive form of chloroperoxidase lacking the heme group and N-glycans.

Abstract: By mutant colony screening of Caldariomyces fumago a mutant was isolated which was slightly greenish on fructose minimal medium and grew slower in comparison to the wild type. The supernatant samples lacked the Soret band typical for the heme group of the CPO and nearly no CPO activity was detected. SDS-PAGE analysis of mutant culture supernatant samples showed production of a 38–40 kDa protein while wild type samples contain the 42 kDa CPO protein. Protein identification using nanoLC-ESI-MS/MS was performed and based on three peptides the protein in the mutant culture was identified as CPO. No differences in the CPO gene sequences of wild type and mutant were found indicating a post-translational defect in protein maturation. Deglycosylation experiments using CPO from wild type and mutant were carried out. After removing N-linked oligosaccharides from wild type CPO a protein band at 38–40 kDa was detected. Our results reveal that the mutant protein lacks the heme group as well as the N-glycans.

Corrosion studies under conditions of thermal desalination I. Pilot test loops for the simulation of plant conditions

Abstract: In a pilot test loop conditions of thermal sea-water desalination were simulated, i. e., temperatures between room temperature and 120°C, oxygen contents between saturation and 2 ppb, flow velocities up to 6 m/s and various pH values were controlled over a long time with appropriate regulation devices. In two specimen chambers of different design corrosion rates of non alloyed and low alloyed steels were measured and compared by weight loss and polarisation resistance. Good agreement was obtained in 100 hr experiments and short duration parameter studies. This work contains the experimental and methodical requirements for investigation into the influence of oxygen, flow velocity, pH value and impurities during sea-water desalination which will be presented in part II of the publication. Korrosionsversuche unter den Bedingungen der thermischen Meerwasserentsalzung I. Pilot-Prufkreislauf zum Simulieren von Betriebsbedingungen In einem Pilot-Prufkreislauf werden die Bedingungen der thermischen Meerwasserentsalzung simuliert, d. h. Temperaturen zwischen Raumtemperatur und 120°C, Sauerstoffgehalte zwischen Sattigung und 2 ppb, Stromungsgeschwindigkeiten bis zu 6 m/s und verschiedene pH-Werte werden mit entsprechenden Regelvorrichtungen uber lange Zeit konstant gehalten. In zwei unterschiedlichen Meszellenkonstruktionen werden die Korrosionsraten von unlegierten und niedriglegierten Stahlen uber den Gewichtsverlust und uber Polarisationswiderstandsmessungen ermittelt und miteinander verglichen. Es ergibt sich gute Ubereinstimmung sowohl bei 100-h-Versuchen als auch bei den Kurzzeit-Parameterstudien. Die vorliegende Arbeit enthalt die experimentellen und methodischen Voraussetzungen fur eine unter Teil II vorgesehene Untersuchung des Sauerstoffeinflusses, des Einflusses von Stromungsgeschwindigkeit, pH-Wert und der Wirkung von Verunreinigungen bei der Meerwasserentsalzung.

100 Jahre Bakelit

Abstract: Auf der Suche nach einem Ersatz fur das Naturprodukt Schellack entstand vor rund 100 Jahren mit dem synthetischen “Bakelit” eine neue und die zugleich jungste Werkstoffklasse der Menschheit, die unserer Zeit technisch und kulturell ihren Stempel aufgedruckt hat. Die Erfindung der duroplastischen (hartbaren) Bakelite-Harze durch dem flamischen Chemiker Leo Hendrik Baekeland aus Steinkohlenteer-Phenol und Formaldehyd markiert den Beginn des “Zeitalters der Kunststoffe” im 20. Jahrhundert. About 100 years ago, in search of substitutes for the natural product shellac with the synthetic “Bakelite” a both new and until now the latest material class of mankind was born. The invention of the duroplastic (hardenable) bakelite resins by the Flemish chemist Leo Hendrik Baekeland through reaction of coal-tar phenol with formaldehyde symbolized the beginning of the “plastics age” in the 20th century.