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Oscillations, break

In precise investigation of atomic oscillations in the molecule, it appears that two different types are again distinguishable valence oscillations and deformations or break oscillations. The former consist of the periodic motion of the atoms in the direction of the main valences linking them the oscillation therefore causes an intermittent variable extension and contraction of any bond distance, a few data for which are shown in Table 2. In the break oscillations, however, the deformations of the atom are executed perpendicular to the bond direction and effect a periodic increase and diminution of the valence angle numerical data are also given for these in Table 4. [Pg.39]

Coupling to these low-frequency modes (at n < 1) results in localization of the particle in one of the wells (symmetry breaking) at T = 0. This case, requiring special care, is of little importance for chemical systems. In the superohmic case at T = 0 the system reveals weakly damped coherent oscillations characterised by the damping coefficient tls (2-42) but with Aq replaced by A ft-If 1 < n < 2, then there is a cross-over from oscillations to exponential decay, in accordance with our weak-coupling predictions. In the subohmic case the system is completely localized in one of the wells at T = 0 and it exhibits exponential relaxation with the rate In k oc - hcoJksTY ". [Pg.24]

To prevent surges, a well-trained operator would put the controller in manual mode and freeze the valve in an open position. This stops the control loop oscillations and decreases the compressor discharge resistance, thus breaking the surge cycle. Unfortunately, the operator has no way of knowing how much to open the valve and, subsequently, how much to close it. [Pg.394]

Actually, a total closed-loop phase lag limit of 3i5 degrees is commonly used by designers any closer to 360 degrees would constitute a metastable system. This could result in the power supply breaking out into periods of oscillation when large loads or line transients are experienced. [Pg.205]

Band gap engineetring confined hetetrostruciutres. When the thickness of a crystalline film is comparable with the de Broglie wavelength, the conduction and valence bands will break into subbands and as the thickness increases, the Fermi energy of the electrons oscillates. This leads to the so-called quantum size effects, which had been precociously predicted in Russia by Lifshitz and Kosevich (1953). A piece of semiconductor which is very small in one, two or three dimensions - a confined structure - is called a quantum well, quantum wire or quantum dot, respectively, and much fundamental physics research has been devoted to these in the last two decades. However, the world of MSE only became involved when several quantum wells were combined into what is now termed a heterostructure. [Pg.265]

The induced absorption band at 3 eV does not have any corresponding spectral feature in a(co), indicating that it is most probably due to an even parity state. Such a state would not show up in a(co) since the optical transition IAK - mAg is dipole forbidden. We relate the induced absorption bands to transfer of oscillator strength from the allowed 1AS-+1 (absorption band 1) to the forbidden 1 Ak - mAg transition, caused by the symmetry-breaking external electric field. A similar, smaller band is seen in EA at 3.5 eV, which is attributed to the kAg state. The kAg state has a weaker polarizability than the mAg, related to a weaker coupling to the lower 1 Bu state. [Pg.118]

An interesting improvement from the classical treatment of the bond under stress was proposed by Crist et al, [101], Considering the chain as a set of N-coupled Morse oscillators, these authors determined the elongation and time to failure as a function of the axial stress. The results, reported in Fig. 20, show a decreasing correlation between the total elastic strain before failure and the level of applied force with the chain length. To break a chain within some reasonable time interval (for example <10-3s) requires, however, the same level of stress (a0.7 fb) as found from the simpler de Boer s model. [Pg.112]

Spontaneous nuclear fission takes place when the natural oscillations of a heavy nucleus cause it to break into two nuclei of similar mass (Fig. 17.21). We can think of the nucleus as distorting into a dumbbell shape and then breaking into two smaller nuclei. An example is the spontaneous disintegration of americium-244 into iodine and molybdenum ... [Pg.838]

In systems such as [A... A ]+ where an electron (or a hole) hesitates or oscillates between two equivalent positions on subsystems A or A, symme breakings may occur when the effective transfer integral between the two sites is weak. Hiis will be the case when A and A are far apart, when they are bridged by an "insulating" ligand, or when the two localized MOs concerned by the electron transfer have a very we spatial overlap. [Pg.109]

Jigging is produced by a gas oscillation generator, which could be either mechanical or electromagnetic, separated from the bottom of the jigged section first by a solids knockout hopper and then by a thermal break, which is essentially a packed-bed heat regenerator. To protect further the gas oscillation generator from hot gases, a cooler is interposed between it and the thermal break. [Pg.555]

Most of the evaluation boards of such ESR-sensitive parts are shipped out to customers with only aluminum electrolytic or tantalum capacitors at their outputs. But what really happens is that the customer happily connects the eval board (rather expectantly) into his or her system, and completely forgets there are a bunch of ceramic capacitors all over the system board (for local decoupling at different points). In effect, the switcher can lose that valuable zero in its control loop and break into oscillations (see Figure 3-5). More so if the connecting leads are short. [Pg.83]

These cause dynamic issues to the switching power supply, and usually the only solution to that is to have enough bulk capacitance present on the 12V output rail. Luckily, since the main feedback loop is derived from the primary 5V/3.3V rails of the power supply, there is no minimum ESR requirement for the 12V rail output capacitance, and we can freely add several electrolytic capacitors in parallel. However, modern core processors can place very fast transient load demands on the primary regulated rail, too, and for that we need a whole bunch of ceramic capacitors sitting right at the point of load. In that case we must ensure the converter is designed to accept ceramic loads. Otherwise it will break up into oscillations. [Pg.190]

The model Hamiltonian (37) obtained from Eq.(32) contains solute oscillators linearly perturbed by its coupling with the solvent as well as bilinear terms that break down a total separability between solute and solvent ... [Pg.304]


See other pages where Oscillations, break is mentioned: [Pg.107]    [Pg.149]    [Pg.92]    [Pg.383]    [Pg.1443]    [Pg.1939]    [Pg.86]    [Pg.130]    [Pg.860]    [Pg.813]    [Pg.268]    [Pg.40]    [Pg.147]    [Pg.224]    [Pg.152]    [Pg.323]    [Pg.97]    [Pg.119]    [Pg.190]    [Pg.129]    [Pg.924]    [Pg.19]    [Pg.284]    [Pg.276]    [Pg.192]    [Pg.17]    [Pg.118]    [Pg.127]    [Pg.128]    [Pg.135]    [Pg.136]    [Pg.136]    [Pg.158]    [Pg.215]    [Pg.328]    [Pg.187]    [Pg.84]   
See also in sourсe #XX -- [ Pg.39 , Pg.51 , Pg.52 ]




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