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.

Mass Transfer by Fluid Flow, Convective Diffusion and Ionic Electricity Transport in Electrolytes and Cells

Abstract: The performance of electrochemical processes is not only determined by charge transfer and electrode kinetics, but a number of additional phenomena cause and rule the electrode kinetics (in the microkinetic as well as macrokinetic sense), the heat balance of the cell and the mass balances of all process streams (electrolyte, gases, solid products). Among these factors the fluid dynamic conditions, under which the electrolyte enters, passes and leaves the electrolysis cell or moves in it under free convection, is the most powerful process parameter since hydrodynamics rule mass and heat transport.

DaNa 2.0 – verlässliche Informationen zur Sicherheit von marktüblichen Nanomaterialien

Abstract: Sowohl Wissenschaftler als auch der Burger brauchen verlassliche Informationen, wenn sie faktenorientiert uber die Sicherheit von Nanomaterialien diskutieren wollen. Nicht alle Artikel zu diesem Thema eignen sich fur eine Risikoabschatzung. Deshalb ist es notwendig, geeignete von ungeeigneten Artikeln zu trennen. Dies ist das Ziel des vom Bundesministerium fur Bildung und Forschung geforderten Projekts DaNa 2.0. Hier werden wissenschaftliche Veroffentlichungen in einem transparenten Verfahren unter Verwendung eines Literatur-Kriterienkatalog evaluiert und die Ergebnisse in Form von allgemeinverstandlichen Artikeln auf der Projekt-Website publiziert.

Electrochemistry, 2. Inorganic Electrochemical Processes

Abstract: The article contains sections titled: 1. Chlor-Alkali Electrolysis 1.1. Molten Salt Electrolysis 1.2. Production of Chlorine 1.3. Electrosynthesis of Hypochlorite 1.4. Electrosynthesis of Chlorate 1.5. Electrosynthesis of Perchlorate 1.6. Chlorine Production Using Gas-Diffusion Electrodes 2. Water Electrolysis for Hydrogen Production 3. Anodic Generation of Peroxodisulfuric Acid and Peroxodisulfates 4. Electrowinning and Electrorefining of Metals 4.1. Aqueous Electrolytes 4.2. Melts 5. Electrochemical Processes in Nuclear Fuel Reprocessing 5.1. Electroredox Separation Processes 5.2. Electroreduction Processes 5.3. Electrooxidation 5.4. Corrosion 6. Electrochemical Water and Effluent Treatment 6.1. Cathodic Treatment 6.1.1. Optimization of Cell Design 6.1.2. Electrochemical Reactors and Their Applications 6.1.3. Operation Data of Electrochemical Cells 6.2. Electrodialysis 6.3. Anodic Treatment 6.3.1. Direct Oxidation at the Anode 6.3.2. Indirect Oxidation 7. Electrochemical Gas Purification 7.1. General Aspects 7.2. New Process Developments 8. Electrochemical Shaping

Oxidation Protection of Titanium Aluminides and Ni-Base Superalloys at High Temperatures by the Halogen Effect – Principles and Applications

Abstract: The oxidation protection of TiAl-alloys at temperatures above 750°C can be improved by the fluorine effect. The results of thermodynamical calculations predict a corridor for a positive fluorine effect. Ion implantation of F was performed because of giving the best results. After a high F-loss during heating a thin protective alumina scale acts as a diffusion barrier. The F-depth profiles show a distinct maximum at the metal/oxide interface. The diffusion coefficient of F in TiAl for 900°C was determined. The stability of the F-effect after long oxidation time at 900°C and 1000°C can be explained by the existence of a constant F-amount at the metal/oxide interface ensuring a slow growth of the alumina scale. The fluorine effect was also applied to Ni-base superalloys to improve their high temperature oxidation resistance by forming a dense continuous protective alumina scale.