Oscillation displacement pumps

This result should seem plausible. The assumptions on g x) mean that the restoring force acts like an ordinary spring, and tends to reduce any displacement, whereas the assumptions on /(x) imply that the damping is negative at small x and positive at large x. Since small oscillations are pumped up and large oscillations are damped down, it is not surprising that the system tends to settle into a self-sustained oscillation of some intermediate amplitude. 

Vetter, G. Schweinfurter, F. (1990) Elimination of Disturbing and Dangerous Pressure Oscillation caused by High Pressure Positive Displacement Pumps, in Proc. 6th Int. Conf. on Pressure Surges, BHRA, pp. 309-324. 

The coherent oscillation of the A g mode was a cosine function of time (Fig. 2.8) [21,24-26]. Recent X-ray measurements demonstrated a clear shift in the equilibrium position at photoexcitation [35], as we will see in the next chapter. These results confirmed the displacive generation of coherent A g phonons, as discussed in Sect. 2.2.2. In contrast, the coherent oscillation of the Eg mode was a sine function of time, and its amplitude exhibited a cos 2ip dependence on the pump polarization angle ip. Both features indicated the ISRS generation of the coherent Eg phonons [21,25],... 

Fig. 7.18. Low-pressure interfaces to detectors based on flow injection. (A) Interface to a photometric detector across a membrane. (Reproduced with permission of the American Chemical Society.) (B) Interface to a flow-through photometric sensor with prior derivatization by the modified Griess reaction. (Reproduced with permission of the American Chemical Society.) (C) Interface to a piezoelectric detector. P peristaltic pump, C collector, CUC clean-up column, DB debubbler, SA sulfamic acid, NEDD /V-( 1-naphthyl)ethylenediamine dihydrochloride, SV switching valve, W waste, DF displacement flask, IV injection valve, FC-PZ flow-cell-piezoelectric crystal, OC oscillator circuitry, F frequency counter, PC personal computer. (Reproduced with permission of Elsevier.)...

We now we summarize some of the procedures that are used in analyzing multidimensional IR data. Constants factors are often omitted from the formulas as are the transition dipole factors which are easily incorporated [74] when the modes are a collection of coupled harmonic oscillators. More generally the variations of transition dipole with nuclear displacement should be incorporated. It is often useful to compare the 2D-IR results with the results of other nonlinear experiments because it turns out that various manipulations of these multidimensional signals provide all of the common nonlinear results such as echoes, gratings, degenerate four wave effects, and pump-probe spectroscopy. 

A diaphragm vacuum pump is an oscillating type of positive displacement vacuum pump in which the wall moving to and fro is a diaphragm (Figure 5.4). Today, diaphragm vacuum pumps have become a popular environment-friendly alternative to water jet vacuum pumps (kinetic vacuum pump) at low and medium pumping speeds especially in chemical laboratories and in connection with pilot... 

Isothermal tests started in January 1985 with an initial build-up in temperature limited to 395 C following the appearance of a phenomenon of oscillation of the thermal shield in the main vessel during increased primary pump speed. Investigations on this problem, carried out both on the reactor (visual examination by camera and displacement measurements through the... 

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