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The equation can be used to fit (regress) discrete values of the shift factor a T vs. temperature. Here, values of shift factor a T are obtained by horizontal shift log(a T ) of creep compliance data plotted vs. time or frequency in double logarithmic scale so that a data set obtained experimentally at temperature T superposes with the data set ...
The time–temperature shift factor can also be described in terms of the activation energy (E a). By plotting the shift factor a T versus the reciprocal of temperature (in K), the slope of the curve can be interpreted as E a /k, where k is the Boltzmann constant = 8.64x10 −5 eV/K and the activation energy is expressed in terms of eV.
Doppler shift with source moving at an arbitrary angle with respect to the line between source and receiver. The analysis used in section Relativistic longitudinal Doppler effect can be extended in a straightforward fashion to calculate the Doppler shift for the case where the inertial motions of the source and receiver are at any specified angle.
Once a curve has been fitted, the user can then define various measures of shift, twist and butterfly, and calculate their values from the calculated parameters. For instance, the amount of shift in a curve modeled by a polynomial function can be modeled as the difference between the polynomial parameters at successive dates. In practice, the ...
For any complex number written in polar form (such as r e iθ), the phase factor is the complex exponential (e iθ), where the variable θ is the phase of a wave or other periodic function. The phase factor is a unit complex number , i.e. a complex number of absolute value 1 .
The group delay and phase delay properties of a linear time-invariant (LTI) system are functions of frequency, giving the time from when a frequency component of a time varying physical quantity—for example a voltage signal—appears at the LTI system input, to the time when a copy of that same frequency component—perhaps of a different physical phenomenon—appears at the LTI system output.
This is the formula for the relativistic doppler shift where the difference in velocity between the emitter and observer is not on the x-axis. There are two special cases of this equation. The first is the case where the velocity between the emitter and observer is along the x-axis. In that case θ = 0, and cos θ = 1, which gives:
Stokes shift is the difference (in energy, wavenumber or frequency units) between positions of the band maxima of the absorption and emission spectra (fluorescence and Raman being two examples) of the same electronic transition. [1]