Fabricating variable

The distinction between machine conditions and fabricating variables is a necessary one to avoid mistakes in using problem-and-solution or cause-and-effect relationships to advantage. If the processing variables are properly defined and measured, not necessarily the machine settings, they can be directly... 

Fig. 5.4 Illustrative drawing of a three-electrode electrochemical cell in which the Ti samples are anodized. Fabrication variables include temperature, voltage, pH and electrolyte composition.

The effects of the generation-layer fabrication variables on the sensitometry of a dual-layer photoreceptor prepared with bis(4-dimethylaminophenyl) squaraine (X = H in Appendix 2) have been extensively investigated by Law (1987). The charge acceptance, dark discharge, sensitivity, and the residual... 

It contains no silicate therefore problems associated with silicate e.g. harsh fabric, variable wetting and dyeing and build up on machines, are eliminated. 

Unfortunately, this system is extremely sensitive to minor fabrication variables and with the limited fabrication capabilities available at SRI International, it was not possible to achieve the necessary control to assure preparation of reproducible batches of devices. Thus, farther development of this system has been discontinued. However, successful devices could almost certainly be developed at a more sophisticated manufacturing facility where experimental variables can be closely controlled. 

Mechanical properties, various fabrication variables and cellular behavior... 

The surface profilometer software calculates numerous parameters from the surface roughness profile. As the Advanced Processing Program continues, the research effort will be focused on detennining which of these roughness parameters or additional spectral analysis (max peak/unit distance, fractal dimension, etc.) are predictive of mechanical behavior, and relating them to fabrication variables. 

As mentioned in Sec. 3.3 above, a carbon-fiber composite has a complex nature with wide differences in properties. This is certainly true of carbon -carbon. 1 The task of analyzing the fabrication variables and their effects on the properties of the composite is far from completed. 

The distinction between machine conditions and fabricating variables is a necessary one to avoid mistakes in using cause-and-effect relationships to advantage. If the processing variables are properly defined and measured, not necessarily the machine settings, they can be correlated with the parts properties. For example, if one increases cylinder temperature, melt temperatures do not necessarily also increase. Melt temperature is also influenced by screw design, screw rotation rate, back pressure, and dwell times (see Chapter 7). It is much more accurate to measure melt temperature and correlate it with properties than to correlate cylinder settings with properties. 

In evaluating plastics for a particular cyclic loading condition, the type of material and the fabrication variables are quite important. Remember that the many plastics perform very differently, whether they are TPs, TSs, unreinforced and reinforced composites. 

The test vehicle design has a significant impact on resnlts.The closer the circuit features, the more likely that CAF failures will occur. In addition, the other attributes of the test vehicle design can impact the fabrication variables that inflnence CAF—for example, the thickness of the PCB and drilled hole sizes can lead to high aspect ratios that can be more challenging to manufacture. As a result of these factors, there is not universal agreement on what constitutes a CAF-resistant material. This can vary by OEM and application. 

Source J. Shannon, Jr. and W. Brown. Jr., Effects of Several Production and Fabrication Variables on Sharp Notch Properties of 5AI-2.5Sn Titanium Alloy Sheet at Liquid Hydrogen Temperature, P/oc. ASr/W,Vol 63,1963, p 809... 

In the second case, the deformation method will not be by a standard test, but suitable samples will be designed to fit the microscope. The in situ deformation of polymers is almost always conducted in the SEM at low magnification and is most often used for fibers and fabrics. Variable pressure SEM and AFMs are also... 

Other methods to prepare porous membranes include pyrolysis for carbon membranes, heat treatment and leaching for mesoporous glass membranes, and anodization for alumina membranes. The microporous carbon membranes are prepared by coating a polymeric precursor such as polyfurfuril alcohol and polycarbosilane on porous substrates, followed by controlled pyrolysis under N2 atmosphere [15]. The carbon membrane structure is determined by the fabrication variables, including the polymeric solution concentration, solvent extraction, heating rate, and pyrolysis temperature [16]. 

Briceno, K., Montane, D., Garcia-Valls, R., lulianelli, A. and Basile, A. (2012) Fabrication variables affecting the structure and properties of supported carbon molecular sieve membranes for hydrogen separation. Journal of Membrane Science, 415/416,288-297. 

It is believed that a greater investment of effort in detailed phenomenology of fine oxide powders and precursor-product relationships will return a handsome dividend in terms of both fundamental knowledge and improved understanding and control of fabrication variables. The combination of high-resolution electron microscopy and selected-area diffraction constitutes a powerful characterizing tool. In the particular context of this volume phe-... 

A detailed analysis of the effect on resolution of etching with external control versus light enhanced corrosion has not been made. Qualitatively, results seem similar for both techniques applied to lll-V compounds. Since the process can be followed optically, e.g., with a weak secondary probe beam (9), coulometric monitoring may not be absolutely necessary. Certainly the polarization of the crystal by external means often yields the advantages of using a neutral or mild electrolyte and higher effective quantum yields. At this time, more work Is required to assess the effect of external fabrication variables on the actual performance of the gratings in iasers and spectroscopic instrumentation. 

Jiang B, Kish V, Fauth DJ, Gray ML, Pennline HW, Li B (2011) Performance of amine-multilayered solid soibents for CO2 removal effect of fabrication variables. Int J Greenhouse GasContiol 5(5) 1170-1175. doi 10.1016/j.ijggc.2011.05.035... 

Multiple block copolymers form a domain-matrix morphology due to the chemical and steric incompatibilities of the two chemically different blocks. The surface molecular and morphological structures of a series of block copolyether-urethane-ureas have been studied in detail via Electron Spectroscopy for Chemical Analysis (ESCA) and Fourier Transform Infrared Spectroscopy (FTIR) coupled with internal reflectance techniques. ESCA provides elemental information concerning the very surface, while FTIR provides the molecular and secondary bonding Information of the surface and into the bulk. Bulk and surface chemical and morphological structures are shown to be quite different, and are affected by synthetic and fabrication variables. 

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