Frequency effect parameter

Time-domain instraments digitize the signal at high sampling rates and permit a Fourier analysis into frequency domain in order to study complex resistivity. In frequency domain, the frequency effect parameter is used ... 

Various irradiation parameters were investigated, such as the types of organic additives, intensity of the ultrasound, dissolved gas and distance between the reaction vessel and the oscillator. In the case of frequency effects, other irradiation systems were used. The details are described in the section of effects of ultrasound frequency on the rate of reduction. 

In addition, the effects of pulsatile flow cannot be ignored. One measure of the impact of oscillary flow is the Wcmersley parameter (a) a= h/2tt f/v where r is the tube radius, f the frequency of oscillation and v is the kinematic viscosity of the fluid (Wcmersley, 1955). The degree of departure from parabolic flow increases with and frequency effects may become important in straight tubes when a > 1 (Ultman, 1985). For conditions of these experiments, a exceeds one to beyond the third generation. 

The water proton NMRD profiles of diferric iron transferrin (55) (Fig. 8) indicate a field dependent electron relaxation time with x of about 1.2 x 10 s. The fit must be done by taking into account a static ZFS, which results in a D parameter of about 0.2 cm and EjD = 1/3. The presence of ZFS is indicated by the additional inflection in the profile at about 10 MHz. In the fit, two sets of electron relaxation times (relative to ZFS axes and to external magnetic field axes) were taken into account to describe the low and the high field experimental data, the SBM theory being inadequate to describe the field dependence of the electron relaxation over the whole range of frequencies. Effective electron relaxation times of the order of 10 ° s have... 

The second theoretical development is due to Sokolov (p. 385). This writer attempts to calculate the additional energy of the H-bond in terms which appear to correspond to our effects (A), (B) and (C). The effective parameter is the positive formal charge Z on the hydrogen atom. Plausible variations of the various terms with Z and with the bond distances enable the change of frequency v in the 0—H valence vibration to be estimated, in good agreement with experiment. 

Our first attempt to apply electro-optics in the investigation of the adsorption of neutral polyacrylamide on kaolinite particles was in 1988 [4,5]. Several electro-optical parameters were used to follow the adsorption of polymer on colloid particles—the amplitude of the electro-optical effect, the critical frequency of relaxation of the low- and high-frequency effects, the electro-optical decay time after the switching off of the electric field. Variations in these parameters with concentration of the added polymer give information on the particle electric polarizability, the thickness of the adsorbed polymer layer, the size of aggregates that appear in the suspension due to flocculation [4-10], etc. 

In paper electron diffraction studies of the SO2 and SO3 molecules have been carried out, and the equilibrium parameters of these molecules have been calculated on the basis of the experimental data. The difference between the two sets of parameters proved to be negligible (Table 21). The SO2 and SO3 molecules are rigid and are characterized by high frequency stretching and deformational vibrations It is legitimate to regard effective parameters as nearly equilibrium ones, provided no low-frequency vibrations occur in the molecule. The difference between the equilibrium S=0 bond... 

The assumption implicit throughout this book is that the parameters used to fit or represent molecular transition frequencies and intensities contain insights into molecular structure. These insights can be more useful than the multi-digit fit parameters themselves, especially when simplifying assumptions axe made and tested. Comparisons of observable or effective parameters to those obtained from an exact calculation (true parameters) or a simplified electronic structure model (one-electron orbital parameters) are seldom trivial or unique. The purpose of this book is to help experimentalists and theorists to go beyond molecular fit parameters to terms in the exact microscopic Hamiltonian on the one hand and to approximate electronic structure models on the other. Physical insight, not tables of spectral data and molecular constants, is the ultimate purpose of fundamental experimental and theoretical research. 

Over recent years there has been a steady growth of interest in vibrational effects in the context of ab initio calculations of linear and non-linear molecular response functions. It has been realized that in some cases vibrational may rival electronic contributions to the parameters controlling non-linear optical responses. This is particularly likely where the molecule is of higher symmetry (quadrupolar or octupolar rather than dipolar), and for lower frequency effects where there is little pre-resonant enhancement of the electronic contribution. The main features of the theoretical methodology for the calculation of vibrational response functions were established several years ago and the fundamental papers were reviewed in the previous volume. Recent developments have been the introduction of field induced co-ordinates, improved integration techniques and the first relativistic studies. ... 

The frequency effect of K mainly originates from Ac because the remaining parameters are all independent of frequency in the low frequency region. Based on Debye relaxation model, Ac has following form ... 

FIGURE 10.8 Effect of changing the high-frequency v parameter in the HN model. 

Frequency modulation offers an effective parameter for spectral evolution the modulation index (i). As has been already demonstrated, the modulation index defines the number of partials in the spectrum. An envelope can thus be employed to time-vary the modulation... 

Ametani, A. 1974. Stratified effects on wave propagation—Frequency-dependent parameters. IEEE Trans. Power App. Syst. 93(5) 1233-1239. 

Frequency-Dependent Parameters 1.5.2.1 Frequency-Dependent Effect... 

The factor tq was found to be 10 s, which coincides with the reciprocal of the atomic vibrational frequency. The parameter Uq is taken as the activation energy, and it decreases linearly with tensile stress. The coefficient -y is a stmcmral factor that describes the orientation of the material. Zhurkov defined -y as a coefficient that relates the activation volume, 14. and (p, the localized overstress on a bond, to the average stress in the specimen. The source of stress on the system can be from either mechanical- or thermo-chemical effects. 

Attenuation coefficient is a frequency-dependent parameter. It increases with increasing frequency (low-pass filter effect). As a first approximation, there is a proportiOTiality aoc/. Berzon (1977) gives the following mean values ... 

We will explore the effect of three parameters 2 -and < )> that is, the time delay between the pulses, the tuning or detuning of the carrier frequency from resonance with an excited-state vibrational transition and the relative phase of the two pulses. We follow closely the development of [22]. Using equation (Al.6.73). 

To conclude this section it should be pointed out again that the friction coefficient has been considered to be frequency independent as implied in assuming a Markov process, and that zero-frequency friction as represented by solvent viscosity is an adequate parameter to describe the effect of friction on observed reaction rates. 

The fitting parameters in the transfomi method are properties related to the two potential energy surfaces that define die electronic resonance. These curves are obtained when the two hypersurfaces are cut along theyth nomial mode coordinate. In order of increasing theoretical sophistication these properties are (i) the relative position of their minima (often called the displacement parameters), (ii) the force constant of the vibration (its frequency), (iii) nuclear coordinate dependence of the electronic transition moment and (iv) the issue of mode mixing upon excitation—known as the Duschinsky effect—requiring a multidimensional approach. 

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