Sensitive process steps

Purchase and install instrumentation whose resolution is high enough for the most sensitive process/step... 

The detection of spectral sensitizing action often depends on amplification methods such as photographic or electrophotographic development or, alternatively, on chemical or biochemical detection of reaction products. Separation of the photosensitization reaction from the detection step or the chemical reaction allows selection of the most effective spectral sensitizers. Prime considerations for spectral sensitizing dyes include the range of wavelengths needed for sensitization and the absolute efficiency of the spectrally sensitized process. Because both sensitization wavelength and efficiency are important, optimum sensitizers vary considerably in their stmctures and properties. 

The choice between different types of dryers is often guided by the chemicals involved and their physical properties, particularly heat sensitivity. As when selecting other equipment, the designer should first ask if the step is necessary if so, whether this is the correct or safest process step. Does the material being processed have to have all of the liquid removed Can the downstream step or customer use the material in a liquid, slurry or paste form ... 

In analyzing these data it is necessary to go beyond the curves and determine the expected behavior of the material with respect to notch sensitivity. Problems with notch sensitivity can often be corrected by modifying the processing steps and/or heat treatment. 

In order to establish good electrical contact to the sensitive layer, it was necessary to coat the electrodes with a metal stack of Ti/W (diffusion barrier and adhesion layer) and Pt. The usage of a shadow mask during the metal deposition ensures full compatibility with other MEMS processing steps so that it is possible to fabricate various CMOS-MEMS devices on the same wafer. 

In a coal gasification plant, the "Claus unit is nearly the last in a chain of process steps, and the foregoing steps can have a major effect on the Claus in a number of ways. Most of this paper will be examining the kind of Claus feed, but at the outset re should note that a Claus plant is sensitive to variations in feed rate, and that relatively minor ups and downs in upstream units will tend to amplify into wild fluctuations in the Claus plant. Accordingly our Claus-type plant should be inherently stable, if possible, able to ride through large changes in feed rate as well as composition. 

Sensitization by compounds that contain a labile sulfur atom, such as thiosulfate ion and thiourea, was established by Sheppard in 1925 (121), although Newton (122) obtained this form of sensitization in 1874 without recognizing it. The steps in the sensitizing process involve (a) adsorption of the sensitizer by the silver halide, (b) reaction of the adsorbed sensitizer with silver ions to form Ag2S, and (c) probably rearrangement of the Ag2S molecules on the grain surface to form nuclei. 

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