Design compromises

Because of the complexities of the materials and the effects of the processing on the materials, this is an area where predictability based on scientific data is very limited and casting experience is desirable. Successful products will result from close cooperation between designer, tool designer, mold maker, and processor to arrive at design compromises that make the products acceptable and producible at an economical price. 

The speed of response of the photodiode depends on the diffusion of carriers, the capacitance of the depletion layer, and the thickness of the depletion layer. The forward bias itself increases the width of the depletion layer thus reducing the capacitance. Nevertheless, some design compromises are always required between quantum efficiency and speed of response. The quantum efficiency of a photodiode is determined largely by the absorption coefficient of the absorbing semiconductor layer. Ideally all absorption should occur in the depletion region. This can be achieved by increasing the thickness of the depletion layer, but then the response time increases accordingly. 

The problem with the Clark electrode is that some of these requirements have solutions that are opposing. For instance, flow dependence may be reduced by employing a thicker membrane but this would occur at the cost of increased response time. As a result, most commercially available systems are design compromises that sacrifice a part of some desirable feature. It should he noted that an optical measurement technique where oxygen and/or electrolyte is not consumed will be free of the drawbacks mentioned above. 

In the SOFC, the thickness of the electrolyte layer is a vital consideration, as is any additional biconductor interface 20-50 jtm is referred to as a thick electrolyte film, a design compromise between the minimisation of electrical losses and freedom from defects. Thin films may go down to nanometres and are more difficult to make without defects. Global Thermoelectric (Kuo etal., 1999) is in SOFC production at 6 xm and InDEC (Section 4.12) at 5 p,m. In the small-tube SOFC the membrane thickness is about half a millimetre. It is difficult to see the latter thickness coming down for improved efficiency to 6 xm, impossibly delicate tubing. 

Tablet dosage forms have to satisfy a unique design compromise. The desired properties of rapid or controlled disintegration and dissolution of the primary constituent particles must be balanced with the manufacturability and esthetics of a solid compact resistant to mechanical attrition.

Catalyst particle size is a very important factor in possible pressure variation. While catalyst effectiveness normally improved upon the use of smaller particles, it is often at the expense of higher pressure drops along the reactor length, so a design compromise is sometimes necessary. 

As an alternative to the use of a thin layer electrolysis method, systems based on the use of fiber optic cable for transmission of infrared radiation may be used in an in situ dip probe made for monitoring the course of conventional bulk electrolysis experiments. Unlike thin layer cell methods, this spectroelectrochemical technique requires no cell design compromises which diminish the accuracy of the voltammetric data that also may be obtained during the course of the electrolysis. 

Several devices are available for separating ions with different mass-lo-charge ratios. Ideally, the mass analyzer should be capable of distinguishing minute mass differences. In addition, the analyzer should allow passage of a sufficient number of ions to yield readily measurable ion currents. As with an optical monochromator, to which the analyzer is analogous, these two properties are not entirely compatible, and design compromises must be made. 

The government succeeded in moving rapidly, facilitated in part by its experience with the Trabajar program. Even though the latter had been discontinued, some of the same people who had worked on the Trabajar program were still available in the central ministry and municipalities, so not all the capacity had been lost. The other factor that facilitated the speed of response was the design compromises made in relation to targeting criteria and enforcement of the work requirements. 

Design Compromises for Efficacious and Safe Electrical Stimulation. 127... 

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