Coarse control

Set the humidistat (if fitted) downwards and note when the heater(s) come on. As before, results that are more accurate are obtained by swinging room conditions, but (a) we will have ascertained that the direction of operation is correct and (b) the method is sufficient for the relatively coarse control required. Reset. 

Where evaporative condensers and water cooling towers have only one fan (or fan drive motor), coarse control can he effected hy on-off switching. The time lag will then depend on the mass of water in the circuit, and the sensing element needs to have a wide differential to prevent frequent motor starts. Towers should have thermostatic control of the fan to prevent water freezing on the packing in winter. 

A motor unit is defined as an alpha motor neuron and all of the skeletal muscle fibers it innervates. The number of muscle fibers innervated by an alpha motor neuron varies considerably, depending upon the function of the muscle. For example, the muscles of the eyes and hands have very small motor units. In other words, each alpha motor neuron associated with these muscles synapses with only a few muscle fibers. As a result, each of these muscles is innervated by a comparatively large number of alpha motor neurons. Densely innervated muscles are capable of carrying out more precise, complex motor activities. On the other hand, antigravity muscles have very large motor units. For example, the gastrocnemius muscle of the calf has about 2000 muscle fibers in each motor unit. Muscles with large motor units tend to be more powerful and more coarsely controlled. 

Koch, K. E., Xu. J., Duke, E. R., McCarty, D. R., and Yuan, C. X. 1995. Sucrose provides a long distance signal for coarse control of its genes affecting its metabolism. In "Sucrose Metabolism, Biochemistry and Molecular Biology" (H. G. Ponlis, G. Salerno, and E. Eccheverria, eds.), pp. 266-277. American Society of Plant Physiologists, Rockville, MD. 

Fig. 2-7. Thermocouple potentiometer. Ih, 25Q 10-turn Helipot Ri, 50 variable resistor (fine control) Rs, 1000 variable resistor (coarse control) lUe 4000 wire wound M, galvanometer.

Attempts to utilize pure d.c. power were unsuccessful. The power supplies available were designed to deliver several hundred milliamperes and had relatively coarse controls which did not permit sufficient control, resulting in runaway or burning in two of the substrate wire. 

The apparatus has been reported previously ( ). The micro-manipulator had coarse control in the X and Y axes and a precise vernier for the Z axis. A reference plane was established by lowering the microprobe until electrical contact was established at points several millimeters away from the colony in all directions. The colony was traversed by the microprobe at the center line, at several locations progressing toward the edge, and adjacent agar was also probed. Small, medium, and large colonies were selected. 

For coarse control, the lower portion of the reactor 2 may be displaced relative to the upper hemisphere. When the two parts are separated, neutrons emanating from one part, which would normally enter the other, fail to do so because of escape through the gap between the hemispheres. When the two parts are placed in juxtaposition, this excess leakage or escape of neutrons is reduced so that a larger propbrtion of those neutrons emanating from one part will enter into the chain reaction in the other hemisphere. In this manner the reproduction ratio may be changed to a value below unity when the hemispheres are separated a maximum amount, to... 

Regulation of enzyme level serves as a coarse control over fatty acid synthesis. In response to changes in physiological state, the levels of the enzymes of fatty acid synthesis fluctuate coordinately. Fatty acid synthesis is also regulated by the direct action of metabolite effectors on key enzymes in the pathway. This means of control is more responsive to sudden alterations in cellular fatty acid requirements. In the case of the committed acetyl-CoA carboxylation step, citrate has been shown to be a positive feed-forward allosteric effector. Since this is the rate-determining step, activation by citrate can effectively adjust the rate of fatty acid synthesis to momentary fluctuations in cellular needs. 

In general the fuel channels contain fiiel elements in a uniform array, but tiie occupancy of a control rod channel may vary in accordance with its purpose for core control. It may contain either a fine or coarse control rod at an appropriate insertion level, an emergency shutdown device (ESD) or other core viewing or monitoring devices. Tlie possible occupancy of the 185 control rod channels is given below ... 

Where the foot is used to control a machine, the heel should rest on a support and in operating the control the foot should only need to be raised (extended) a minimum amount and the control actuated by flexing the foot to give a fine degree of control. Foot controls that require the whole foot to be raised allow only very coarse control and are best restricted to operations that require only a simple either/or position of the control. 

Control One safety rod and two sets of three shut-off rods one fine, four coarse control rods of boron carbide in stainless steel annulus... 

Control Coarse control/shut-off six arms (Pluto seven arms) cadmium in stainless steel sheath, two vertical safety rods, one vertical line control rod of cadmium in stainless steel tubes, D2O reflector dumping... 

Control Variable up to 6 boron steel safety rods, 2 fine control and 16 coarse control rods dependent on the experiment... 

Control Four safety rods cadmium in stainless steel sheath in hollow fuel elements, vertical fine control rod (same type). Control is by variation by D2O level and/or reactor fine control rod. Signal-type coarse control arms (cadmium in stainless steel sheath) may be adjusted when sub-critical to stimulate coarse control/shut-off arms in Dido and Pluto... 

Control All control and safety rods are B.C packed in steel tubes six safety rods and six shutdown rods two coarse control rods and one fine... 

In this technique, depicted in Fig. 1.4, forces are measured between two partially silvered atomically smooth mica sheets mounted on silica cylinders, which are positioned with their long axes at 90 degrees to each other. The vertical separation between the cylinders is controlled mechanically for coarse control and for fine control using calibrated piezoelectric transducers. One of the cylinders is fixed, and the other is mounted on a cantilever spring of a calibrated spring constant, capable of measuring forces as low as 10 nN. The separation of the partially silvered layers is determined to a resolution of 0.1 nm using optical interferometry. The difference between the piezoelectric translation and surface separation allow... 

Figure 9.6 Manometer system for applying negative or positive pressures to the micropipet Coarse control is achieved by use of a simple syringe to displace volume above the front reservoir (on the right). Fine control, microatmospheres, is achieved by adjusting the position of the front reservoir using the sprung micrometer drive. The whole manometer system can be leveled with the pipet tip in order to achieve zero pressure at the pipet tip, using the central coarse screw. In-line pressure transducers measure small pressures (0-1000 dyne cm ) and large pressures (1000-100000 dyne cm ) [84].

The required electrical interlock reliabilities comprise the interlock schedule from which the coarse control system structure is derived (Fig 2). Those channels based upon programmable logic, including associated input sensing devices and output actuators are considered in detail in the following sections. 

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