Systemic response

Estimate the slopes in region II of the isotherms in Fig. XI-13. Derive adsorption laws from these estimates and discuss the differences in the two systems responsible for the different isotherms. 

Measurement Requirements. Any analysis of measurement requirements must begin with consideration of the particular accuracy, repeatabihty, and range needed. Depending on the appHcation, other measurement considerations might be the speed of system response and the pressure drop across the flow meter. For control appHcations repeatabihty may be the principal criterion conversely for critical measurements, the total installed system accuracy should be considered. This latter includes the accuracy of the flow meter and associated readout devices as well as the effects of piping, temperature, pressure, and fluid density. The accuracy of the system may also relate to the required measurement range. 

Estrogens coordinate the systemic response during the ovulatory cycle, including the growth and maintenance of the reproductive tract, pituitary, breasts, and other tissues. Estrogens are also responsible for maturation of the skeleton and development of female secondary sex characteristics when females enter puberty. The other important functions of estrogens include modulation of many metaboHc processes (76). 

The enzyme system responsible for the biosynthesis of PGs is widely distributed in mammalian tissues and has been extensively studied (2). It is referred to as prostaglandin H synthase (PGHS) and exhibits both cyclooxygenase and peroxidase activity. In addition to the classical PGs two other prostanoid products, thromboxane [57576-52-0] (TxA ) (3) and prostacyclin [35121 -78-9] (PGI2) (4) are also derived from the action of the enzyme system on arachidonic acid (Fig. 1). 

There is no easy understanding of the spectral properties of these compounds in general, which may or may not have a built-in chromophoric system responsible for a long-wavelength absorption like 7,8-dihydropteridin-4-one or a blue-shifted excitation like its 5,6-dihydro isomer. More important than the simple dihydropteridine model substances are the dihydropterins and dihydrolumazines, which are naturally occurring pteridine derivatives and reactive intermediates in redox reactions. 

Higher-Order Lags If a process is described by a series of n first-order lags, the overall system response becomes proportionally slower with each lag added. The special case of a series of n first-order lags with equal time constants has a transfer function given by ... 

Control system, speed control, pressure control, and process control, so that consideration can be given to remote control, speed or pressure variation that can be tolerated, and system response speed... 

The eomplex FCC system involves not only turbomaehinery, but also related proeess eomponents. All of these must be properly designed and sized to operate within system parameters from startup to steady state design point, and through shutdown. System response to emergeney eonditions is also mandatory. Computer simulation is, therefore, an integral part of the design proeess. A eomputer program eapable of this simulation is deseribed below. 

The interesting aspect of torsional problems in turbomachiner s terns is that the first indication of a problem is usually a ruptured shah oi coupling in the field. Silent and deadly, a torsional response can lurk a synchronous or non-synchronous frequencies, and be steady or transieri. in nature. Once a torsional problem is found in the field and the excua tions are determined to be inherent in the system, the only solution avail able, to put the system back on line quickly, is to decouple the excitation source or to dampen the system response. 

On the bad side, many of the elastomeric types are highly nonlinear in their characteristics. The elastomeric compression-type couplings are very soft at small wind-ups under low loads, but once the elastomer has filled the available squeeze space, the coupling is effectively rigid. This makes prediction of system response difficult unless the load and coupling characteristics are well defined prior to installation. 

System response studies should include rotor residual unbalance, which can be verified during manufacture. An additional study must be made to consider the application of a deliberate unbalance weight at a location chosen by the vendor. The amount and location of the unbalance must be used in the following test. Normally the location chosen is ihe coupling. 

In control engineering, the way in which the system outputs respond in changes to the system inputs (i.e. the system response) is very important. The control system design engineer will attempt to evaluate the system response by determining a mathematical model for the system. Knowledge of the system inputs, together with the mathematical model, will allow the system outputs to be calculated. 

The total response of the system is always the sum of the transient and steady-state eomponents. Figure 3.1 shows the transient and steady-state periods of time response. Differenees between the input funetion X[ t) (in this ease a ramp funetion) and system response Xo t) are ealled transient errors during the transient period, and steady-state errors during the steady-state period. One of the major objeetives of eontrol system design is to minimize these errors. 

JLo(.v) is the Laplace transform of the output function, or system response. 

Generalized second-order system response to a unit step input... 

The generalized seeond-order system response to a unit step input is shown in Figure 3.19 for the eondition K = 1 (see also Appendix 1, sec ord.m). 

Flence, for a sinusoidal input, the steady-state system response may be calculated by substituting. v = )lu into the transfer function and using the laws of complex algebra to calculate the modulus and phase angle. 

Using equations (6.18) and (6.21), values for the modulus and phase angle may be ealeulated as shown in Table 6.1. The results in Table 6.1 may be represented as a Polar Plot, Figure 6.4(a) or as a reetangular plot. Figures 6.4(b) and (e). Sinee the reetangular plots show the system response as a funetion of frequeney, they are usually referred to as frequeney response diagrams. 

Find the pulse transfer function and hence calculate the response to a unit step and unit ramp. T = 0.5 seconds. Compare the results with the continuous system response Xo t). The system is of the type shown in Figure 7.9(b) and therefore... 

The robust eontrol problem is to find a eontrol law whieh maintains system response and error signals within preseribed toleranees despite the effeets of uneertainty on the system. Forms of uneertainty inelude... 

FMEA examines each potential failure mode of a process to determine effects of failure on the system. A failure mode is anything that fails hardware. It may be a loss of function, unwanted function, out-of-tolerance condition, or a failure such as a leak. The significance of a failure mode depends on how the system responses to the failure. 

The problem with function event trees is that some functions are quite complex and must be analyzed. If a function event tree models the plant s response to an accident initiator, modeling system responses in a fault tree will not clearly exhibit the functional criteria. 

Risk Reduction Factors Coutrol/ rator responses. Alarms, Control system response. Manual anti automatic ESD, Fire/gas detection system Sa/ety System Responses Relief valves. Depressurization system. Isolation systems, High reliability trips. Back-up systems... 

Figure 1.1 Clause relationship with management system responsibility...

Traditional control systems are in general based on mathematical models that describe the control system using one or more differential equations that define the system response to its inputs. In many cases, the mathematical model of the control process may not exist or may be too expensive in terms of computer processing power and memory. In these cases a system based on empirical rules may be more effective. In many cases, fuzzy control can be used to improve existing controller systems by adding an extra layer of intelligence to the current control method. 

Protection is the branch of electric power engineering concerned with the principles of design and operation of equipment (called relays nr protective relays ) which detect abnormal power system conditions and initiate corrective action as quickly as possible in order to return the power system to its normal state. The quickness of response is an essential element of protective relaying systems—response times of the order of a few milliseconds are often required. Consequently, human intervention in the protection of system operation is not possible. The response must be automatic, quick, and should cause a minimum amount of disruption to the power system. 

When the maximal stimulus-response capability of a given system is saturated by agonist stimulus, the agonist will be a full agonist (produce full system response). Not all full agonists are of equal efficacy they only all saturate the system. 

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