Considerations in design

Although the LED is one of the most basic optoelectronic devices, there exists a variety of complex and interacting material and stmctural considerations in designing these devices. These include the choice of materials for emission wavelength of the LED as well as the geometry and fabrication methods of the device. The principal stmctural properties of commercially available LEDs are summarized in Table 1. 

Orrell, W. H., Physical Considerations in Designing Vertical Thermosyphon Reboilers, Chemical Engineering, September 17, 1973. 

These alloys have corrosion resistance similar to that of copper, with mechanical properties equivalent to mild steel. Because silicon bronzes do not generate sparks under shocks, they can be used in the fabrication of explosion-proof equipment. Compared to tin bronzes, the tinless bronzes have a higher shrinkage (1.7-2.5% against 1.3-1.5% of tin bronzes) and less fluid-flow, which is an important consideration in designing. 

The main design criteria of most TPE dies are to ensure that changes in flow channel diameter from the extruder barrel bore to the die exit are equal. Most of the viscoelastic materials exhibit a die swell on exit from a die. TPEs tend to show die swell significantly lower than that of typical thermoplastics. This swell must be taken into consideration in designing dies and adjusting extrusion condition to achieve a perfect profile. The die swell normally increases with increasing hardness and shear rate and decreasing temperature. 

Considerations in designing a market basket survey also include the period of time over which product samples will be collected. For example, should samples be collected over one year to illustrate an annualized perspective on the data of interest, or is the issue more aptly addressed with a shorter collection period such as one season or one month ... 

All of this means that the use of energy is a very important consideration in designing a plant. This has become especially true since 1970, when a general awareness began to develop that the United States was entering a decade of energy crises. In 1972 the natural gas shortage became so acute that in many areas of the... 

II. ENZYME SUBSTRATE SPECIFICITY CONSIDERATIONS IN DESIGN OF PRODRUGS... 

An important consideration in designing and performing asymmetric reactions with high regioselectivity and enantioselectivity, especially for those in which more than one stereogenic center is formed, is the need to carry out the reaction with a combination of kinetic resolution in the initial asymmetric synthesis. 

If these conclusions are valid they have important implications for the design of tests to evaluate relative toxicity and also for structure/activity theories for example if the relationship between polarity and toxicity is strongly influenced by decay processes then it is important that these are given appropriate consideration in designing candidate compounds. The analysis presented above also gives a strong support for further pharmacodynamic studies of pesticide action... 

Work-up becomes a major consideration in designing processes for preparation of all phases of drug development after Phase 1, as 60 to 80% of both capital expenditures and operating costs go to separations. (Eckert, 2000) Work-up conditions can limit the selection of reagents and routes. Simple work-ups with a minimal number of transfers decrease the number of opportunities for physical losses and contamination. 

One of the most important considerations in designing a process for converting methanol to olefins was to find the best way to remove the considerable heat of reaction. Despite the fact that we are stopping the reaction at the intermediate olefin product, the reactions leading to these intermediates give off almost 90% of the heat released in the overall MTG reaction scheme (49 vs. 56 kJ/mole of methanol converted for MTO vs. MTG). Efficient removal of the heat of reaction is one of the main reasons a fluid-bed reactor was selected for scale-up demonstration. A second advantage of the fluid-bed is that product composition can be kept constant, since optimum catalyst activity can be maintained by continuous make-up and regeneration. 

A brief treatment of the major contributors to optical spreading is certainly in order because it will clarify some of the considerations in designing and adjusting the spectrometer. In some cases it will also allow us to compute a useful approximation to the optical spread function. In the same vein, we later describe the behavior of the most common, useful, and easily described form of electrical noise smoothing the single-stage RC filter. 

The author describes key considerations in design. The hyperbolic shape is shown to be an advantageous structural solution. 

Woodward SC. How fibroblasts and giant cells encapsulate implants considerations in design of glucose sensors. Diabetes Care 1982, 5, 278-281. 

For analytical testing purposes, there are two key considerations in designing an isolator. The first consideration is that the design of the isolator should be such that the individual utilizing the isolator is sufficiently protected from exposure to the material being tested. The second consideration is that the isolator construction must be such that the analytical equipment placed inside the isolator can function properly. These key design considerations are discussed in detail below. 

Therefore, a principal consideration in designing a reactor system is reaction heat management. 

Key considerations in designing preclinical safety evaluation programs for biopharmaceuticals. Program designs and material needs Investing for success. BIO 2005, Philadelphia, June 20,2005. 

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