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Very low frequency

Except at very low frequencies, pressure broadening may be removed simply by working at a sufficiently low pressure. Doppler broadening may be reduced or removed by two general methods, which will be discussed briefly below. [Pg.37]

Practice for insulation testing. Large a.c. rotating machines w4th high voltage at very low frequency. [Pg.271]

In the low frequency region, the calculations predict nanotube-specifiic Eig and E g modes around 116 cm and 377 cm respectively, for (10,10) armchair naiiotubes, but their intensities are expected to be lower than that for the A g mode. However, these Eig and E2g modes are important, since they also show a diameter dependence of their mode frequencies. In the very low frequency region below 30 cm a strong low frequency Raman-active E2g mode is expected. However, it is difficult to observe Raman lines in the very low frequency region, where the background Rayleigh scattered is very strong. [Pg.81]

Overpressure can lead directly to all three hazards. It can lead directly and immediately to injury, to fire or explosion if there is an ignition source, and to pollution if there is not enough containment. Therefore, we must have a very high level of assurance that overpressure is going to have a very low frequency of occurrence. [Pg.394]

At very low frequencies the movement of the panel will be controlled by the stiffness, as inertia is a dynamic force and cannot come into effect until the panel has measurable velocity. Stiffness controls the performance of the panel at low frequencies until resonance occurs. As the driving frequency increases, the resonance zone is passed and we enter the mass-controlled area. The increase in the sound-reduction index with frequency is approximately linear at this point, and can be represented by Figure 42.8. [Pg.658]

Values of and Qb can be calculated for molecules in the gas phase, given structural and spectroscopic data. The transition state differs from ordinary molecules, however, in one regard. Its motion along the reaction coordinate transforms it into product. This event is irreversible, and as such occurs without restoring force. Therefore, one of the components of Q can be thought of as a vibrational partition function with an extremely low-frequency vibration. The expression for a vibrational partition function in the limit of very low frequency is... [Pg.170]

Ordinarily, the measurements are made over a frequency range from 20 Hz to 50 kHz. Certain difficulties arise in measurements extended over wider ranges of frequency. However, methods suitable for measurements at very low frequencies, down to 1 mHz, have recently been developed that can be used to obtain additional information concerning the properties of electrochemical systems. [Pg.210]

We can see here that at very low frequencies, R, tends toward the sum R + Rp and Cj tends toward infinity. At very high frequencies, R, becomes equal to R and Cj becomes equal to Q. Therefore, by extrapolating the experimental data to zero and to infinite frequency, we basically can find the kinetic reaction parameter Ry (or p) and the EDL capacitance as well as the electrolyte s ohmic resistance. [Pg.211]

On the magnitude plot, the low frequency asymptote is a line with slope -1. The high frequency asymptote is a horizontal line at Kc. The phase angle plot starts at -90° at very low frequencies and approaches 0° in the high frequency limit. On the polar plot, the Gc(jco) locus is a vertical line that approaches from negative infinity at co = 0. At infinity frequency, it is at the Kc point on the real axis. [Pg.157]

Relevant only for a small fuel time constant and under low pressure Various modes of dynamic flow redistribution Occurs with steam injection into vapor suppression pools Very-low-frequency periodic process (-0.1 Hz)... [Pg.487]

The alleles containing 4 and 9 copies of the TSER repeat were primarily confined to African populations. TSER 4 accounted for 2-7% of TSER alleles in all African populations except the Sudanese. However, TSER 4 was also found in a British Caucasian subject but not among the American-Caucasian population studied [53]. This suggests that TSER 4 occurs at a low frequency in Caucasian populations. The absence of the TSER 4 allele in the Sudanese population may be a result of the small sample size or due to the fact that this allele occurs at very low frequencies in this population. The latter possibility would make sense as this population is an admixture of Negroid and Caucasoid characteristics at both the morphological and molecular levels [17]. [Pg.505]

Another aspect of the EMI problem for low-temperature experiments is the injection of RF (at megahertz frequencies and up) energy via the wiring into the cryostat. A common RF-induced problem is a heating caused by local telephone broadcasters. RF transmitters often ride in over resistance bridge wirings whose signal are at very low frequencies. [Pg.244]

Ruptures Large releases of very low frequencies. Typically vessel, tank pipeline or hose failures from internal, external, or third party sources and fire conditions (i.e., BLEVE conditions). [Pg.44]

In general, from a clinical standpoint, the development of resistance to the quinolones has not emerged as a major problem. Recent reviews have placed this issue in appropriate perspective [40]. Resistance to the new quinolones, as the result of single-step mutation occurs at a very low frequency (< 10 9) high-level resistance may be obtained by in vitro multiple exposures of organisms... [Pg.244]

The two techniques, ENDOR and ESE envelope modulation, supplement each other. ESE envelope modulation seems to be more sensitive in detecting nuclear transitions at very low frequencies but is limited in the frequency range by yeB , where ye denotes the gyromagnetic ratio of the electron and Bj the microwave pulse amplitude. ENDOR, whose sensitivity increases with frequency, suffers on the other hand from the small transition probability at low frequencies. [Pg.47]

Assume now that weak forces have been applied to the molecular rotations and translations so that the eigenvalues X of the Fm matrix correspond to the 3N — 6 (3N - 5 for a linear molecule) real frequencies X = 4tt2v12 of the molecule plus six (or five) very low frequencies (ordinarily calculated as zero frequencies) that correspond to translations and rotations, uncoupled from the larger molecular vibrations. Then, if one recognizes that (1) the determinant of a diagonal matrix is just the product of its diagonal elements, and (2) if a matrix A can be written as a matrix product of B and C, then... [Pg.75]

Very low-frequency vibrations have been observed in proteins (e.g., Brown et al., 1972 Genzel et al., 1976), which must involve concerted motion of rather large portions of the structure. By choosing a suitable set of proteins to measure (preferably in solution), it should be possible to decide approximately what structural modes are involved. Candidates include helix torsion, coupled changes of peptide orientation in /3 strands, and perhaps relative motions of entire domains or subunits. These hypotheses should be tested, because the low-frequency vibrations probably reflect large-scale structural properties that would be very useful to know. [Pg.312]


See other pages where Very low frequency is mentioned: [Pg.1150]    [Pg.261]    [Pg.64]    [Pg.93]    [Pg.95]    [Pg.319]    [Pg.2012]    [Pg.78]    [Pg.733]    [Pg.114]    [Pg.112]    [Pg.139]    [Pg.633]    [Pg.57]    [Pg.157]    [Pg.163]    [Pg.93]    [Pg.26]    [Pg.108]    [Pg.103]    [Pg.104]    [Pg.158]    [Pg.269]    [Pg.203]    [Pg.483]    [Pg.9]    [Pg.193]    [Pg.245]    [Pg.268]    [Pg.615]    [Pg.241]    [Pg.39]    [Pg.31]   
See also in sourсe #XX -- [ Pg.6 , Pg.7 , Pg.8 , Pg.9 , Pg.10 , Pg.11 , Pg.12 , Pg.13 , Pg.14 , Pg.15 , Pg.16 , Pg.17 , Pg.18 , Pg.19 , Pg.20 , Pg.21 , Pg.22 , Pg.23 ]

See also in sourсe #XX -- [ Pg.78 ]




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