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Effects of Disturbance

A number of authors have studied the variation in the soils compressional behavior due to varying degrees of disturbance. The effect was to help in extrapolating to in-situ properties. Particular attention has been given to the consolidation behavior (Rutledge, 1944 Schmertmann, 1955), but other soil properties were also considered (Burmister, 1936 DeLory and Salva, 1969 Milovic, 1970). [Pg.193]

Note Pj-modal mean bulk density Pj,-density of seawater Pci grain density [Pg.193]

Nondestructive measurement of consolidation in marine soils. (From Richards, A.F., and Chaney, R.C., Mar. Georesour. Geotec., 15,305-321,1997. Reproduced with permission of Taylor Francis Group.) [Pg.193]

Sedimentation consolidation curve obtained by the modal mean method and utilizing only the nondestructive measurement of saturated bulk density within a plastic core tube. The calcium carbonate content was measured by conventional methods at the DSDP. Core from Bauer Deep, east of the East Pacific Rise and west of Callao. The numerical w values are based on an assumed grain density of 2.7 mg/m. (From Richards, A.F., and Chaney, R.C., Mar. Georesour. Geotec., 15,305-321,1997. Reproduced with permission of Taylor Francis Group.) [Pg.194]


Control of contaminant at the face of a fume cupboard depends on the movement of air through the working aperture. The velocity must be sufficiently high to resist the effects of disturbances created by the operator, other personnel, equipment, cross-drafts, etc. It should not be so high, however, as to cause disturbances to equipment in the cupboard or to create eddies in the wake of the operator or from the cupboard itself that will adversely effect containment. [Pg.890]

Parker, G.G. The Effect of Disturbance on Water and Solute Budgets of Hillslope Tropical Rainforest in Northeastern Costa Rica PhD Thesis Univ. Georgia Athens, Greece, 1985 161 p. [Pg.455]

Le Chatelier s principle demonstrates the effect of disturbances on chemical equilibrium. Le Chatelier s principle can also help predict whether or not disturbances will affect the equilibrium constant. None of these will affect the equilibrium constant EXCEPT the —... [Pg.36]

The primary objective of distillation column control is to maintain the specified composition of the top and bottom products, and any side streams correcting for the effects of disturbances in ... [Pg.231]

The pH value of the bioreactor is subjected to external disturbances (also called load changes), and the task of suppressing or rejecting the effects of disturbances is called regulatory control. Implementation of a controller may lead to instability, and the issue of system stability is a major concern. The control system also has to be robust such that it is not overly sensitive to changes in process parameters. [Pg.7]

Figure 24 Effects of Disturbance on Reverse Acting Controller. 35... Figure 24 Effects of Disturbance on Reverse Acting Controller. 35...
Figure 29 Effect of Disturbance on Proportional Plus Rate... Figure 29 Effect of Disturbance on Proportional Plus Rate...
It has been suggested (Insam and Haselwandter 1989 Anderson and Domsch 1990) that the metabolic quotient can be used as an index of ecosystem development. As an ecosystem reaches maturity, selection pressure towards efficient use of available resources results in a larger microbial biomass with a lower metabolic quotient. Nonetheless, Wardle and Ghani (1995) concluded that qC02 can be insensitive to disturbance and ecosystem development, fails to distinguish between effects of disturbance and stress and does not decline predictably in response to ecosystem development wherever stress increases along successional gradients. [Pg.216]

Bahri, P Bandoni, A., and Romagnoli, J. A. (1996). Effect of disturbances in optimizing control Steady-state open-loop backoff problem. AIChE J. 42,983-995. [Pg.200]

Ecosystem characterization Long-term monitoring should continue in order to enable estimation of natural variability, as well as to establish a baseline against which to evaluate the effects of disturbances. Standard environmental risk assessment approaches may not be useful if the components of the ecosystem in question have not been determined. Further research on... [Pg.24]

Rikhari HC, Sharma S, Nadeem M, Palni, L.M.S. The effect of disturbance levels, forest types and associations on the regeneration of Taxus wallachiana Lessons from the Central Himalaya, Curr Sci 79 88—90, 2000. [Pg.46]

Nuclei density in the fines loop was estimated by light scattering. This technique was shown to be effective in minimizing the effect of disturbances in nucleation rate of the product CSD. [Pg.11]

Figure 10 gives results obtained with quartz samples of various grain size as indicated by the different specific surface areas. Although these surface values differ by a factor of 20, the differences in the dissolution pattern for equal areas of exposed surface are barely significant. This indicates again that no difficulties in interpreting the data arise from special effects of disturbed surface layers or small particle sizes. [Pg.177]

Jafarey et al. (61) derived a simple, approximate equation for binary distillation by simplifying the solution to Smoker s equation. Their equation is powerful for predicting the effect of disturbances on column performance. This makes their equation particularly useful in computer and microprocessor control, where it can be applied to estimate the effect of disturbances and the control action needed to compensate for them. This application is highlighted in Examples 3.8 and 3.9. The Jafarey et al, equation is... [Pg.126]

The challenges in SMB control are not only the complex nonlinear process dynamics, but also the long delays of the effect of disturbances. The required control strategy has to be able to handle multivariable dynamics with time-delays and hard constraints. Model Predictive Control (MPC) has been proven to be the most effective control strategy for this type of problems [1,2]. Only recently, a few scientific publications have addressed the automatic... [Pg.177]

Fig. 3 The effect of disturbance frequency on optimization performance. (View this art in color at www.dekker.com.)... Fig. 3 The effect of disturbance frequency on optimization performance. (View this art in color at www.dekker.com.)...
Some disturbances can be measured, but the presence of others is only recognized because of their influence on process and/or output variables. The state-space model needs to be augmented to incorporate the effects of disturbances on state variables and outputs. Following Eq. 4.28, the state-space equation can be written as... [Pg.91]

In the end, we must remind ourselves that however well we may analyze our patients for personality disorders or help them separate from the ill effects of disturbing parental influences in childhood, there remains the unknown source of psychic conditioning in the region of the primal Self to be tapped wherever we can find it. The process illustrated in this series is never completed once and for all we will always have further work to do. As Jung wrote near the end of his life. [Pg.148]

Canceling the effects of disturbance changes in upstream units,... [Pg.272]

V.21 Derive the nonlinear, steady-state feedforward control system that will keep the exit temperature of a stirred tank heater at the desired set point despite any changes in the inlet temperature or flow rate, T, and F,. The feedforward control system should be capable of (1) rejecting the effect of disturbance changes, and (2) tracking any set point changes. Identify all relevant transfer functions. [Pg.593]

Control actions will generally lag in their effects on the process because of delays in signal propagation around the control loop an actuator may not respond immediately to an external command signal (called dead time) the process may have delays in responding to manipulated variables (time constants) and the sensors may obtain values only at certain sampling intervals (feedback delays), lime lags restrict the speed and extent with which the effects of disturbances, both within the process itself and externally derived, can be reduced. They also impose extra requirements on the controller, for example, the need to infer delays that are not directly observable. [Pg.66]

Point A represents the strength of a sample, havii the same disturbance as the laboratory test samples, but having the same water content as the unconsolidated soiL Conservative estimate of completely undisturbed strength. Not fully compensate for effect of disturbance... [Pg.208]

Process control systems generally operate with a constant set point. It should be emphasized that exact control is not always necessary and over instrumentation should be avoided. Solar dryers generally have some parts of large capacities that reduce the effects of disturbances. [Pg.340]


See other pages where Effects of Disturbance is mentioned: [Pg.844]    [Pg.395]    [Pg.323]    [Pg.63]    [Pg.347]    [Pg.143]    [Pg.126]    [Pg.487]    [Pg.141]    [Pg.386]    [Pg.205]    [Pg.869]    [Pg.299]    [Pg.81]    [Pg.264]    [Pg.70]    [Pg.70]    [Pg.321]    [Pg.180]    [Pg.144]    [Pg.193]   


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