Known good designs

Figure 1.26 MEMS standard cells. The use of standard cells can increase productivity in layout while avoiding layout errors by using known good designs. (Reprinted with permission from Dr. Mary Ann Maher, SoftMEMS.)...

For a good design, consider q, = 0.80 and determine approximate value of jlf from the plot of (//versus Re curve for the known j and /versus Re characteristics of each fluid side surface. The specific step-by-step design procedure is as follows. 

A convenient set of variables to specify are F, z, Tp, N, Np, p, T pfiux, L/D, and D. Multiple feeds can be specified. This is then a simulation problem with distillate flow rate specified. Because the matrices require that N and Np be known, for design problems, a good first guess of N and Np must be made (see Chapter 7). and then a series of simulation problems are solved to find the best design. 

Known expected rock types, ground water detail, i.e. adequate site investigations at the planning stage good design... 

Acoustic control materials are used to reduce noise problems where the design of a machine or tool hasn t solved the problem, or to add to the reduction in noise resulting from good design. As noted earlier, acoustic control materials take two basic forms -porous material which reduces reflection of sound, known as reveiberation, or material of a relatively high density which can reduce the vibration of sound-emitting surfaces or reduce the transmission of sound through a barrier, such as a wall or floor. Certain composites achieve the same effect with less density. 

It is well known that the intramyocardial stress and pressure (Streeter et ai, 1970 Mirsky, 1974), the coronary flow pattern, and the energy demand (Gibbs, 1978), are not evenly distributed in the LV wall. Furthermore, the spatial orientation of the muscle fibers is a function of the distance from the endocard (Streeter et ai, 1979). Thus, a spatial model which will describe distributed properties is highly desired. A good design of a distributed-parameter model depends on the following data and assumptions ... 

What was needed was a test protocol that allowed the wetting balance to be used for what it was designed for measuring solderabUity. This required producing a test sample that is considered uniform and consistent, sample to sample. This known good coupon was created and subsequently a test protocol developed. This detailed test protocol maybe found in the Appendix sections of the ANSI-JSTD-002 and ANSI-JSTD-003 documents. 

The plots (or their simpler two-dimensional form, which is a plot of /h vs /p, in effect assuming/ to be invariant) have considerable practical utility in solvent selection (Burke 1984). The solubility of a polymer is often achieved using a mixture of solvents. As a general rule, a mixture of solvents will dissolve a polymer if the solubility parameter of that mixture lies close to that of a known good solvent for the polymer. In designing mixed solvent systems the Teas plot allows the solubility characteristics of solvent mixtures to be predicted to some extent. In Fig. 2.3, the solvents carbon tetrachloride (CCI4) and methanol (CH3OH) are clearly nonsolvents for poly(methyl methacrylate)... 

Grades of acetal resins specifically designed to enhance the excellent lubricity of the material, without sacrifice in other properties, are known. These include Delrin AF, Ultraform N2311, and Celcon LW materials. Antistatic grades, particularly useful in electronic appHcations, have been developed. At least one recendy introduced new grade, Celcon SR90, claims good scuff resistance. 

Activated alumina and phosphoric acid on a suitable support have become the choices for an iadustrial process. Ziac oxide with alumina has also been claimed to be a good catalyst. The actual mechanism of dehydration is not known. In iadustrial production, the ethylene yield is 94 to 99% of the theoretical value depending on the processiag scheme. Traces of aldehyde, acids, higher hydrocarbons, and carbon oxides, as well as water, have to be removed. Fixed-bed processes developed at the beginning of this century have been commercialized in many countries, and small-scale industries are still in operation in Brazil and India. New fluid-bed processes have been developed to reduce the plant investment and operating costs (102,103). Commercially available processes include the Lummus processes (fixed and fluidized-bed processes), Halcon/Scientific Design process, NIKK/JGC process, and the Petrobras process. In all these processes, typical ethylene yield is between 94 and 99%. 

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