External controls

KU-1 Stormer-type A 100-5,000 -50 external control, usually poor ... 

External Control. The use of external control to govern the release of dmgs from dehvery systems has largely been experimental. A number of mechanisms have been explored, and include external sources such as electrical currents, magnetism, ultrasound, temperature changes, and irradiation. 

External control of the process is achieved by devices that are specially designed, selected and configured for the intended process-control application. The text below covers three very common function classifications of process-control devices controllers, final control elements, and regufators. 

FIG. 10-58 A form of acid egg. External controls required for automatic operation are not shown. 

EXPERIMENTAL UNITS FOR PLANAR CHROMATOGRAPHY WITH EXTERNAL CONTROL PROPARTIES OF THE CHROMATOGRAPHIC SYSTEM... 

THIN-LAYER CHROMATOGRAPHY OF BENZOIC ACIDS WITH EXTERNAL CONTROL PROPERTIES OF THE MOBILE PHASE... 

A modification of the thin-layer chromatography (TLC) technique with external control over the chromatographic system is proposed. 

It follows that the position of thermodynamic equilibrium will change along the reactor for those reactions in which a change of tire number of gaseous molecules occurs, and therefore that the degree of completion and heat production or absorption of the reaction will also vaty. This is why the external control of the independent container temperature and the particle size of the catalyst are important factors in reactor design. 

LEED can be used to determine the atomic structure of surfaces, surface structural disorder, and to some extent, surfiice morphology, as well as changes in structure with time, temperature, and externally controlled conditions like deposition or chemical reaction. Some examples are briefly discussed here ... 

The above considerations indicate the great importance of experimental studies on the influence of externally controlled conditions, in... 

Most pumps that are used in hydraulic applications have a fixed displacement which cannot be changed except by replacing certain components. However, in some, it is possible to vary the size of the pumping chamber and thereby the displacement by means of external controls. Some unbalanced vane pumps and many piston units can be varied from maximum to zero delivery or even to reverse flow without modification to the pump s internal configuration. 

It is the basic task of electrochemical kinetics to establish the functional relations between the rate of an electrochemical reaction at a given electrode and the various external control parameters the electrode potential, the reactant concentrations, the temperature, and so on. From an analysis of these relations, certain conclusions are drawn as to the reaction mechanism prevailing at a given electrode (the reaction pathway and the nature of the slow step). 

In electrocatalysis, in contrast to electrochemical kinetics, the rate of an electrochemical reaction is examined at constant external control parameters so as to reveal the influence of the catalytic electrode (its nature, its surface state) on the rate constants in the kinetic equations. 

Greater co-operation among producers could be developed. The World Wide Web has provided a model of sharing information based on very clear technical principles and formats, but with no formal bureaucracy or external control. Researchers using the Web can move easily among computers of many research institutions that are linked to the Internet. Perhaps the National Measurement Institutions that produce RM could make their instruments and laboratories just as open and available to researchers who are characterizing a new material (Rasberry 1998). 

Luft and Tsuo have presented a qualitative summary of the effects of various plasma parameters on the properties of the deposited a-Si H [6]. These generalized trends are very useful in designing deposition systems. It should be borne in mind, however, that for each individual deposition system the optimum conditions for obtaining device quality material have to be determined by empirical fine tuning. The most important external controls that are available for tuning the deposition processs are the power (or power density), the total pressure, the gas flow(s), and the substrate temperature. In the following the effects of each parameter on material properties will be discussed. 

The availability of thermodynamically reliable quantities at liquid interfaces is advantageous as a reference in examining data obtained by other surface specific techniques. The model-independent solid information about thermodynamics of adsorption can be used as a norm in microscopic interpretation and understanding of currently available surface specific experimental techniques and theoretical approaches such as molecular dynamics simulations. This chapter will focus on the adsorption at the polarized liquid-liquid interfaces, which enable us to externally control the phase-boundary potential, providing an additional degree of freedom in studying the adsorption of electrified interfaces. A main emphasis will be on some aspects that have not been fully dealt with in previous reviews and monographs [8-21]. 

The former phase, interference term and hence the reaction outcome. The latter phase, 5(E), serves as an analytical tool that provides a route to the phases of the scattering wavefunctions. 

When calculating the potential of mean force along a fluctuating coordinate r, we can at best observe r (e.g., the instantaneous molecular extension), but we do not set it explicitly. Therefore, r is no longer an externally controlled coupling parameter, and Jarzynski s identity does not immediately apply. However, as was shown in [3], an extension produces the desired result. 

For very stiff pulling springs (where r is almost a coupling parameter under external control), we can instead pursue the so-called stiff-spring approximation of Park et al. [45]. A Fourier representation of the spring Boltzmann factor on the right-hand side of (5.60) results in... 

Yang, I. V. (2006). Use of external controls in microarray experiments. Methods Enzymol. 411, 50-63. 

For all MicroSYNTH systems, reactions are monitored through an external control terminal utilizing the Easy WAVE software packages. The runs can be controlled by adjusting either the temperature, the pressure, or the microwave power output in a defined program of up to ten steps. The software enables on-line modification of any method parameter and the reaction process is monitored through an appropriate graphical interface. An included solvent library and electronic lab journal feature simplifies the experimental documentation. 

This method can be applied not only for polyion detection but for the detection of small ions as well. In contrast to potentiometric electrodes the external control of the... 

While the rate of an electron-transfer process and thus the mode of the resulting spin-density distribution can be controlled by the length and the conformation of the spacer groups, the ion pairing creates an additional factor that can serve as some external control even for a given choice of subunits and spacers. 

Methodology appropriate for the measuring of DTA profiles has been extensively reviewed [12,13]. A schematic diagram illustrating the essential aspects of the DTA technique is shown in Fig. 3. Both the sample and reference materials are contained within the same furnace, whose temperature program is externally controlled. The outputs of the sensing thermocouples are amplified, electronically subtracted, and finally shown on a suitable display device. 

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