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Materials Degradation (material + degradation)
Selected AbstractsA review of metal release in the food industryMATERIALS AND CORROSION/WERKSTOFFE UND KORROSION, Issue 5 2006M. S. Jellesen Abstract The objective of this review is to outline literature on metal release in the food industry. Key results are reviewed from publications with high scientific level as well as papers with focus on industrial aspects. Examples of food products with a corrosive effect are given, and cases concerning processes, storing equipment as well as cleaning and sanitising procedures are reviewed. Stainless steel is the most widely used metallic material in the food industry; however other metals and their alloys are also briefly treated. The review deals with phenomena mainly relating to electrochemical corrosion, but also examples of material degradation as a consequence of wear and corrosive wear are presented. [source] Properties modification of PET vascular prosthesesJOURNAL OF PHYSICAL ORGANIC CHEMISTRY, Issue 5 2009W. Chaouch Abstract Aging mechanisms have been investigated on polyethylene terephthalate (PET) fibres extracted from various vascular prostheses in order to identify the different modifications of the material's degradation. NMR spectroscopy provides a comprehensive view of chemical structures of macromolecules. Examination of a series of PET fibres showed significant chemical differences between the virgin prostheses and the explants, especially for diethylene glycol (DEG) and cyclic oligomeric groups. These analyses revealed that PET failures in vascular prostheses are susceptible to hydrolysis during in vivo stay. We also extended this 1H NMR technique to determine the hydroxyl and carboxyl end-group concentrations. In order to validate the 1H NMR results, complementary techniques , chemical titration and classical viscosimetry , were used. The obtained results showed an increase in end-group concentrations and a decrease of the viscosity averaged macromolecular weight (M,) for the explants. Copyright © 2009 John Wiley & Sons, Ltd. [source] A step-wise incremented Fourier series model for chemical reactivity predictionJOURNAL OF CHEMOMETRICS, Issue 6-7 2006Saloua Saidane Abstract In this paper, chemical reactivity is modeled as a time series of events defined by a reactant's concentration decay measured at consecutive discrete time periods. Since traditional time series techniques such as ARIMA and current Artificial Neural Networks require large data sets that are typically not available for chemical reactions, we developed a Step Wise Incremented Fourier Series (SWIFS) algorithm to model and predict nonlinear short time series. The application of SWIFS to experimental data from first- and second-order reactions produced a significant improvement in prediction accuracy over traditional integrated rate laws. In forward-time prediction, SWIFS has achieved significantly higher prediction accuracy with first- and second-order chemical reactions data. SWIFS also proved more robust in terms of error propagation caused by the effect of the size of the estimation set. The proposed SWIFS model also outperformed rate law models in backwards-time prediction. The ability of SWIFS to provide high accuracy in predicting chemical reactions may have beneficial implications on the efficiency of industrial production of chemicals as well as on the effective control of hazardous materials degradation. Copyright © 2007 John Wiley & Sons, Ltd. [source] Progress in corrosion protection as a requirement for technical progress,MATERIALS AND CORROSION/WERKSTOFFE UND KORROSION, Issue 7 2009W. Fürbeth Abstract In many of the more recent technologies, corrosion plays a crucial role in determining their successful application. The present paper identifies such important corrosion issues in a number of technologies, which are currently under development or have been recently discussed. In this sense, CO2 sequestration, fuel cells, offshore wind energy and other offshore technologies, geothermal energy, advanced coal conversion technologies, nuclear energy, light weight construction in transport, ionic liquids as well as medical technologies are discussed with respect to corrosion problems and existing research needs. In this way, this paper intends to show the complexity and the variety of corrosion topics of today and at the same time, point at the economic aspects and the impact on daily life. In the end, this leads to an introduction of the World Corrosion Organization and its study on future needs for research and development in materials degradation and corrosion control. [source] | ||||||||||