Control characteristic

In addition to the mobihty control characteristics of surfactants, critical issues in gas mobihty control processes are surfactant salinity tolerance, hydrolytic stabihty under reservoir conditions, surfactant propagation through the reservoir, and foam stabihty in the presence of cmde oil saturations. 

Adaptive Control. An adaptive control strategy is one in which the controller characteristics, ie, the algorithm or the control parameters within it, are automatically adjusted for changes in the dynamic characteristics of the process itself (34). The incentives for an adaptive control strategy generally arise from two factors common in many process plants (/) the process and portions thereof are really nonlinear and (2) the process state, environment, and equipment s performance all vary over time. Because of these factors, the process gain and process time constants vary with process conditions, eg, flow rates and temperatures, and over time. Often such variations do not cause an unacceptable problem. In some instances, however, these variations do cause deterioration in control performance, and the controllers need to be retuned for the different conditions. 

Describe in detail the controlling characteristics of the finished product ... 

Zone temperature control characteristics (set point, type of thermostat, throttling range)... 

Orifice plates may be treated in the same way as valves using an appropriate value of flow control characteristic within acceptable cavitation limits. 

M. Yamaguchi, T.Saito, M. Izumitani, S. Sugita and Y. Tsutsunri, Anal5fsis of Control Characteristics Using Fuel Cell Plant Simulator. IEEE Transactions on Industrial Electronics, 37 (1990) 378. 

At AWE, the Lewis acid-catalyzed bulk polymerization route has been the main synthesis route to poly(m-carborane-siloxane) elastomers. Our selection has been based on considerations of safety, availability of key reagents, and ease of scale-up operations. An understanding of the physical and chemical properties of these materials, and how these properties can be modified through the synthesis process, is essential in order to develop materials of controlled characteristics. 

Yoshino, K. Takahashi, H. Muro, K. Ohmori, Y. Sugimoto, R. 1991. Optically controlled characteristics of Schottky gated poly(3-alkylthiophene) field effect transistor. J. Appl. Phys. 70 5035-5039. 

Many control problems can be better solved with a diaphragm controller. The function of the diaphragm controller (see Fig. 3.27) can be easily derived from that of a diaphragm vacuum gauge the blunt end of a tube or pipe is either closed off by means of an elastic rubber diaphragm (for reference pressure > process pressure) or released (for reference pressure < process pressure) so that in the latter case, a connection is established between the process side and the vacuum pump. This elegant and more or less automatic regulation system has excellent control characteristics (see Fig. 3.28). 

Fixed thermocouples shall be located at key sterilizer positions, as justified by the sterilizer operation and control characteristics (i.e., at exhaust or vent line, in recirculation heating medium line, next to controller sensor, as applicable). 

Table 1 summarizes the environmental control characteristics for the aseptic processing complex. The areas classihcations are based on activity... 

Table 1 (continued) Summary of Environmental Control Characteristics... 

A Throttling characteristics of centrifugal (c) -and positive- displacement (e, reciprocating d, rotary) pumps. B Control characteristics of positive displacement pumps a,b, Systems characteristics (b, after speed control) VFluid flow Ap, Differential pressure n, Speed h, Stroke length A, B, B, Operating points. 

If the valve is applied for control purposes the closing section is usually cone-shaped in order to obtain the appropriate control characteristics. One is recommended to install easily replaceable wear-resistant inserts as valve seats (Fig. 4.2-6 A). 

The interest in periodically forced systems extends beyond performance considerations for a single reactor. Stability of structures and control characteristics of chemical plants are determined by their responses to oscillating loads. Epidemics and harvests are governed by the cycle of seasons. Bifurcation and stability analysis of periodically forced systems is especially important in the... 

Which of the three criteria is chosen is very much dependent upon the characteristics of the system. If the controlled variable response exhibits large deviations (i.e. there are large errors), then use of the ISE function will lead to the determination of controller parameters which will give the best control characteristics. As the errors are squared, minimisation of the ISE will be particularly effective. Use of the IAE function will suppress small errors better than will the ISE criterion as it treats errors of all magnitudes in a uniform manner. The ITAE function should be employed where there are persistent errors since this will lead to an amplification of the effect (and thus a weighted influence on the consequent estimation of the controller parameters) of the latter at large values of f. 

Fig. 10 (a, b) Schematic mechanism demonstrated for a reflective color M-paper with magnetically controllable characteristics, (c, d) The intensity of magnetic field dependence on the reflection spectra of chiral nematic mixtures doped with magnetite nanoparticles that are surface modified with oleic acid and a chiral pyridine-based dopant, as well as photographs of both formulations before and after a magnetic field of 1,000 GS was applied (see photograph insets above) [364], (Copyright 2010, Taylor Francis)... 

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