Cyclic oscillation

When the slope of the heat balance line is close to the slope of the inflexion point of the mass balance curve, there is no longer a well-defined working point (solid fine in Figure 8.4) and the reactor may enter cyclic oscillations of temperature and conversion, even for constant working parameters. To avoid these oscillations, the condition must be fulfilled [2] ... 

Lang, D.A., D.R. Matthews, J. Peto R.C. Turner. 1979. Cyclic oscillations of basal plasma glucose and insulin concentrations in human beings. New Engl. J. Med. 301 1023-7. 

The method of cooling the fluid reactive composition of a neutronic reactor which comprises cyclically oscillating the reactive composition through a chain reaction zone while maintaining a sufficient amount of the reactive material in the reaction zone to maintain the chain reaction. 

It is not exceptional for a long, steep elevator conveying a fine powder to experience a cyclic oscillation of behaviour at the end of a batch run. Whereas the machine may operate smoothly, continuously transporting away all material entering the hopper until the infeed ceases, once the hopper empties and the inlet region clears, the material in transit is no longer backed-up by following product. 

A biphasic curve of ALA-synthetase activity of liver mitochondria of rats, induced by AlA and possible involving repression by heme, was first observed by Narisawa and Kikuchi [107]. The enzyme activity increased slightly during the first 12 hours, then remained unchanged for several hours, and then continued to increase during the next 24 hours to tenfold the control value. No biphasic curve was observed with DDC by Wada et al. [86]. Waxman et al. [108] reported that, after the establishment of induced ALA-synthetase in the rat for 3 days, the administration of 2 mg of hemin initiated a series of cyclic oscillations of ALA-synthetase activity with a period of 8 to 12 hours the oscillations continued for 3 days. To explain these oscillations they postulated a repression by heme of the synthesis of ALA-synthetase and thence an overshoot of abnormally increased synthesis. 

Figure4.10.31 (a, b) Modeling of cyclic oscillations in population density by the Lotka-Volterra model of...

Local Ice Deformation Under the Influence of Natural Forces. Field Observations and Analyses of Cyclic Oscillations... 

In the X- and y-directions (Figure 49.5b), an ion trajectory is more difficult to visualize. It is essentially the sum of two main effects one a simple oscillation caused by the rapid cyclic alternations of the RF field (Figure 49.5c), the other a more complicated drift or guided motion due to the inhomogeneity of the RF field within the space between all four rods. 

Gyroscopic moments Drive torque Cyclic forces Oscillating torques... 

Wall excursion with possible flow oscillation Cyclic flow regime transitions and flow rate variations... 

The electronic adsorption spectra for the complexes [Ir(OH)6]", where n = 0-2, have been resolved and peak maxima locations, molar extinction coefficients, oscillator strengths, and band half-widths calculated.44 Bands have been assigned in the main part to be one-electron MLCT transitions. Spectrophotometrically determined rate constants for the OH reduction of the IrVI and Irv complexes at 25 °C in 3M NaOH are (2.59 0.09) x 10—3 s—1 and (1.53 0.05) x 10 4 s 1 respectively. The activation energy for the reduction, Irv—>IrIV, is nAkcalmoC1. Cyclic voltammetry and potentiostatic coulometry of [Ir(OEI )r,]2 in 3M NaOH on a Pt electrode show that during the electro-oxidation compounds of Irv and IrVI are formed.45... 

Oscillations describes this cyclic characteristic. There are three types of oscillations that can occur in a control loop. They are decreasing amplitude, constant amplitude, and increasing amplitude. Each is shown in Figure 10. 

The imaginary roots imply that [X] and [Y] undergo oscillation changes but never become equal to [X]st and [Y]st and at [A] = [A]0 they remain unattainable. It can be shown that the system in the coordinates [X][T] executes the cyclic motion around zero (zero has the coordinates [X] = [X]st, [T] = [T]st). 

In addition to the deformation modes described above, there are some other modes of practical interest, for example, the cyclic spreading, recoiling, and oscillation mode typical of solder jetting process.[5°1 This mode leads to a final splat shape of multiple surface ripples at low substrate temperatures and hemispherical shape without surface ripples at high substrate temperatures. 

Double-Layer Charging in Cyclic Voltammetry. Oscillating and Nonoscillating Behavior... 

Cyclical phenomena, such as ENSO events, the North Atlantic Oscillation, the North Pacific Oscillation, and a phenomenon in the Southern Ocean called the Southern Annular Mode, have important impacts on the solubility pump. This was illustrated for the ENSO events in Figure 25.5b. These oscillations are all sensitive to global climate change. In the case of the Southern Ocean, the impact of climate change on circulation is complicated by the zonation associated with the polar and subpolar frontal boundaries (Figure 10.10). As a result, some parts of the Southern Ocean are expected to respond differently than others to changes in increases and meridional overturning circulation rates. 

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