Requirements for control

Third, design constraints are imposed by the requirement for controlled cooling rates for NO reduction. The 1.5—2 s residence time required increases furnace volume and surface area. The physical processes involved in NO control, including the kinetics of NO chemistry, radiative heat transfer and gas cooling rates, fluid dynamics and boundary layer effects in the boiler, and final combustion of fuel-rich MHD generator exhaust gases, must be considered. 

Also, the electronic control-valve device s level of immunity to, and emission of, electromagnetic interference (EMI) can be an issue in the chemical-valve environment. EMI requirements for the control-valve devices are presently mandatory in the European Community but voluntary in the United States, Japan, and the rest of the world. International Electrotechnical Commission (lEC) SOI, Parts I through 4, Electromagnetic Compatibihty for Industrial Process Measurement and Control Equipment, defines tests and requirements for control-device immunity. Immunity and emission standards are addressed in CENELEC (European Committee for Electrotechnical Standardization) EN 50 081-1 1992, EN 50 081-2 1993, EN 50 082-1 1992, and prEN 50 082-2 1994. 

The top pressure controller varies the level of liquid in the condenser, so it, like the reboiler, must have extra surface for the derating required for control. Many other control methods also require some control surface. If noncondensibles are present, a vent should be provided. Otherwise, they collect at the liquid seal. With large amounts of noncondensibles, another type of system should be considered. 

Introducing COSHH. A bnef guide for all employers to the new requirements for controlling hazardous substances m the workplace introduced m the Control of Substances Hazardous to Health Regulations 1988 (COSHH)... 

TABLE 9.7 Important Information and Requirements for Control and Instrumentation... 

How do you identify the need for statistical techniques required for controlling and verifying process capability ... 

Choking, or expansion of gas from a high pressure to a lower pressure, is generally required for control of gas flow rates. Choking is achieved by the use of a choke or a control valve. The pressure drop causes a decrease in the gas temperature, thus hydrates can form at the choke or control valve. The best way to calculate the temperature drop is to use a simulation computer program. The program will perform a flash calculation, internally balancing enthalpy. It will calculate the temperature downstream of the choke, which assures that the enthalpy of the mixture of gas and liquid upstream of the choke equals the enthalpy of the new mixture of more gas and less liquid downstream of the choke. 

The basic instrumentation required for controlled-potential experiments is relatively inexpensive and readily available commercially. The basic necessities include a cell (with a three-electrode system), a voltammetric analyzer (consisting of a potentiostatic circuitry and a voltage ramp generator), and an X-Y-t recorder (or plotter). Modem voltammetric analyzers are versatile enough to perform many modes of operation. Depending upon the specific experiment, other components may be required. For example, a faradaic cage is desired for work with ultramicroelectrodes. The system should be located in a room free from major electrical interferences, vibrations, and drastic fluctuations in temperature. 

Because of the very high reactivity of platinum in many reactions of technological interest, such as those in fuel cells, and the well-demonstrated requirement for control... 

Even the most superficial evaluation of bioequivalency requirements for controlled-release products will indicate that for some of these products, at least, the conventional AUC, Tmax, and Cmax measures of bioequivalency may well be insufficient. Thus, for a non-pulsatile sustained-release product with a dosing interval of 24 hours (as compared to 4 hours for the noncontrolled product), the time period during which plasma concentrations are maintained at essentially a plateau level might well be regarded as of critical... 

The tetracyclic [l,2,4]triazino[4,3-/]phenanthridines 162 showed fungicidal activity, where they appeared to be the key requirements for control of Erysiphe graminis tritici (90MI3). 

The goal of treatment for active Crohn s disease is to achieve remission however, in many patients, reduction of symptoms so that the patient may carry out normal activities or reduction of the steroid dose required for control is a significant accomplishment. 

There is no standard or specification within the industry which specifies the dual redundancy for PLCs used for process control functions. The requirement for control system redundancy is primarily a function of the desired availability or demand of the process control system. Most control sytem availability percentages are in the range of 99 to 99.9%. Depending on the type of PLC system configuration defined, availability generally improves in relation to the amount of redundancy added to the various system components, but does not necessarily improve system reliability. 

Wright, E.J., Sinclair, E.A., and Annis, P.C. 2002. Laboratory determination of the requirements for control of Trogoderma variabile (Coleoptera Dermestidae) by heat. J. Stored Prod. Res. 38, 147-155. 

When the pressure of the hydrogen gas and the demand by the customer are greater than those applicable under the provisions of this paragraph, the requirements for control and limiting of the pressure of hydrogen gas delivered are included in para. PL-3.13.3. 

The reaction is exothermic, and temperature control is required for control of the reaction. Good agitation is essential to avoid occlusion of unreacted starting materials in the sticky precipitate. 

One of the best ways to determine that potential is to examine the Material Safety Data Sheets (MSDS), which by law in most jurisdictions must be provided by the manufacturer for any hazardous material used in the workplace and made available to the employees by plant management. The MSDS provides all the information necessary to determine the hazard potential and the requirements for control of any hazardous substance. Still other information can be found in the various guidelines published by the American Industrial Health Association, or by the U.S. National Safety Council, or by NIOSH (the U.S. National Institute for Occupational Safety and Health) or various other national, state, or provincial government bodies. (See Appendix II for information on sources.) Once you have an inventory, of course, you can start relating potential health problems to possible sources in particular areas. Also, in the process of preparing this report, you will begin to build an invaluable library that will stand you in good stead for further consideration of the problems at hand. 

Oxygen requirements for controlling odours from pig slurry by aeration... 

OXYGEN REQUIREMENTS FOR CONTROLLING ODOURS FROM PIG SLURRY BY AERATION... 

One of the major difficulties in the synthesis of these binary indole-indoline alkaloids is the necessity of generating the natural PARF (priority antireflective) (12) relative stereochemistry between C-14 and C-16, as well as the requirement for controlling the absolute stereochemistry at C-16, which must be (5). Other epimers at these positions lack the high cytotoxicity, with mitotic arrest at metaphase, that is the basis of the anticancer activity of these compounds (13,14). 

Although the GLP revisions of 1987 excluded animal feed and water from the definition of control article, it would appear that such common vehicles as saline solutions and carboxymethylcellulose solutions still fall within the definition. Such a strict definition of the term for such innocuous vehicles as saline solutions is quite burdensome when one considers the requirements for control articles that are found in other sections of the GLPs characterization [ 58.105(a)], stability testing [ 58.105(b)], sample retention [ 58.105(d)], and inventory [ 58.107(d)]. It does not appear that this comprehensive definition is enforced by FDA field investigators in the course of GLP inspections. 

The inability of the engine to produce a useful propulsive force at zero or low flight speeds necessitates the use of an auxiliary power plant to initially accelerate the vehicle to the required take-over speed of the ramjet. Such auxiliary power is also required for controlled landing of the vehicle. As a consequence the ramjet engine is not well-suited for conventional aircraft applications (with the exception of the helicopter) and the principal application of the engine appears to be further restricted to missiles or other similar vehicles of a one-flight expendable nature ... 

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