Practical Design

Because the select TFT is used only for (dis)charging the storage capacitor (the gate capacitor of the drive TFT is much smaller than the storage capacitor), we can use a small device geometry, W = 20 pm, L = 20 pm. This transistor is basically working in the linear region, and the on-resistance of the select TFT can be calculated by use of Eq. (2)  

Taking a modest mobility of 0.5 cm2 V 1 s 1, and Vgs and Vj of —30 V and +10 V, respectively, the calculated on-resistance is only 2 MC2. Assuming a storage capacitor of 1.2 pF, which conveniently corresponds to an area of 200 pm x 50 pm, the (dis)charging time is only 2.5 ps, much less than the required row time for a VGA-sized display at 60 Hz refresh rate ( 30 ps). 

All these calculations show that pentacene TFTs are feasible for active-matrix OLED display backplanes. For the Penn State/Kodak practical realization mentioned above, a 48 x 48 pixel bottom-emission display panel was designed on a 64 mm x 64 mm glass substrate. To obtain good yield, a design rule of 10 pm was used for the minimum feature size (line width or separation) for most structures on the test panel. The coarseness of this design rule is not related to the use of organic compounds, but rather to the simplicity of photolithographic processes. 

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Equation (7.12) is derived in App. C. Practical designs will be limited to some fraction of P ax, that is,... 

A knowledge of the viscous and thermal properties of non-Newtonian fluids is essential before the results of the analyses can be used for practical design purposes. Because of the nonlinear nature, the prediction of these properties from kinetic theories is as of this writing in its infancy. Eor the purpose of design and performance calculations, physical properties of non-Newtonian fluids must be measured. 

The major water desalination processes that ate currendy in use or in advanced research stages are described herein. Information on detailed modeling can be found in the Hterature cited. The major texts on water desalination written since the 1980s are those by Spiegler and Laird (47), Khan (48), which contains many practical design aspects, Lior (49) on the measurements and control aspects, Heitman (40) on pretreatment and chemistry aspects, and Spiegler and El-Sayed (50), an overview primer. Extensive data sources are provided in References 39 and 51. 

This approach attempts to permit the designer to evaluate and optimize alternatives quickly, using shortcut hand calculations. However, if it is to be adopted by practicing design engineers it must be complemented by software for at least the analysis, evaluation, and optimization stages. 

For combustion of simple hydrocarbons, the oxidation reactions appear to foUow classical first-order reaction kinetics sufficiently closely that practical designs can be estabUshed by appHcation of the empirical theory (8). For example, the general reaction for a hydrocarbon ... 

Design Methods for Continuous Tunnel Dryers In actual practice, design of a continuous through-circulation diyer is best based upon data taken in pilot-plant tests. Loading and distribution of solids on the screen are rarely as nearly uniform in commercial installations as in test diyers 50 to 100 percent may be added to the test diying time for commercial design. 

If the liqmd-phase reaction is extremely fast and irreversible, the rate of absorption may in some cases be completely governed by the gas-phase resistance. For practical design purposes one may assume (for example) that this gas-phase mass-transfer limited condition will exist when the ratio yj/y is less than 0.05 everywhere in the apparatus. 

An established design method for this type of system is not available. The practical design of the low-momentum supply with exterior hood system described in the previous part of this section used the flow ratio method. How-evec, the actual exhaust flow rate was adjusted visually to the appropriate value in order to exhaust only the contaminants transported by the supply airflow. 

For practical design, the recommended aspects of the push-pull flow (hood) and the safety factor are as follows ... 

The EUF and FESR are then simple to derive and typical area plots of the range of EUF and FESR against the derived Acg, for gas turbines with varying practical design parameters, are illustrated in Fig. 9.8. 

The final area of concern is to develop a practical design philosophy for composite structures. Is there a philosophy that will enable us to account for and accommodate all the essential behavioral characteristics of composite materials Can we do it without getting bogged down in overly complicated issues ... 

TABLE 17.2.1 Major Organizations Providing Codes and Standards, Recommended Practices, Design Criteria, or Guidelines for Equipment in Chemical and Allied Industry Process Plants... 

Sonti, R. S., Practical Design and Operation of Vapor-Depres-surlzing Systems, Chem. wg> , Jan. 23, 1984, p. 66. 

For practical design, select L/V = (1.5) (0.525) = 0.7875. Select L/V internal reflux lines and add to the equilibrium plot, similar to that shown for a normal curve of Figure 8-35, but unlike the abnormal ethanol curve shown. 

Shorter center distance is a very practical design objective. Such a design uses space economically and allows for a stable operation. In general, center distances are limited by the physical dimensions of the sheaves, or the minimum angle of 6, i.e.. 150". Maximum drive centers are limited only by available V-belt stocked lengths. 

Figure 4-261. Practical design of a drilling parameter sub. (Courtesy Anadrill [ 06].)...

Finally, there is the transfer of sensible heat from the bulk of the water to the surface area. This is so slight in terms of resistance that it is normally neglected. Radiant heat transfer is also ignored for all practical design purposes. 

Recommended Practice Design, Installation, Operation and Maintenance of Internal Cathodic Protection Systems in Oil Treating Vessels, RP-05-75, NACE, Houston (1975)... 

Certain conclusions can now be developed, based on creep-data test results First, for practical design purposes, the data accumulated for up to 100 hours of creep are of no real benefit. There is usually too much variation during this test period, which is of a relatively short duration. 

Depending on construction and orientation of stress relative to reinforcement, it may not be necessary to provide extensive data on time-dependent stiffness properties since their effects may be small and can frequently be considered by rule of thumb using established practical design approaches. When time dependent strength properties are required, creep and other data are used most effectively. There are many RP products that have had super life spans of many decades. Included are products that have been subjected to different dynamic loads in many different environments from very low temperatures to very high corrosive conditions, etc. An example is aircraft primary structures (10,14,62). 

The most likely CVD applications of these superconductors to reach the practical stage are coatings for semiconductor and other electronic-related applications. For 1 arger current-carrying applications, a superconductor coating over a metallic conductor such as copper may also become a practical design because of its advantage over a monolithic superconductor wire. It is able to handle current excursions and has better mechanical properties. 

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