Resistance monitoring methods 1292 Subject

An additional complication with SCF processes is the possibility of complex phase behavior. A thorough understanding of the phase behavior of each reaction mixture is desirable, but not always possible. There is an extensive literature devoted to the investigation and prediction of phase behavior of SCFs [11], and the subject is introduced in chapter 1.2. Spectroscopic monitoring can provide at least an indication of phase behavior for example, which compounds are dissolved in which phase, as well as a method for monitoring the progress of reactions and identifying intermediates and products. It is best to resist the temptation to treat a supercritical reactor as a black box, and simply... 

More generally, ftacture is a vitally important characteristic of materials and is encountered in a variety of different circumstances. In order to determine the strength or resistance to breakage in use, a number of test methods are employed. In these, testing to destruction usually leads to failure by way of fracture of the specimen. The two methods most often used are tensile testing and impact testing. In the former, the material is subjected to a continuous tensile stress. Then the stress and the resulting strain are monitored until the sample breaks. 

Since creep is considered as a key weaknesses of pressure sensitive adhesives, various specific test methods and standards have been developed to evaluate the creep resistance of pressure sensitive adhesives like, for example, in the European Standard EN 1943 ( Self adhesive tapes-Measurement of static shear adhesion ), FINAT (Federation Internationale des Fabricants et Transformateurs d Adhesives et ThermocoUants sur Papier et autres Supports), test method FTM 8 (Resistance to shear from a standard surface), or the Pressure Sensitive Tape Councils test method PSTC 107 (International Standard for Shear Adhesion of Pressure Sensitive Tape) by either monitoring the time- and load-dependent displacement of an adhesive specimen under shear load or simply recording the time to failure. The result of the so called SAFT-test ( Shear Adhesion Failure Temperature ) indicates the temperature at which a sample that has been subjected to an environment with steadily rising temperature under static shear load has failed. 

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