Amplitude variation

So the correlative processing gives additional (to the amplitude) variation of output signal and makes the signal processing a multiparamctric one. Such processing increases the sensitivity and reduces the noises. 

To increase the sensitivity, direction of amplitude variation of probe output signal in defective area must coincide with the one after CCF processing. If the defect decreases the probe signal (single contact probe) A((/should be set Ai// = 0, in the opposite case (twin contact probe) it should be set Aif/= n. So the instrument should be supplied with a device to adjust A((/ and to sustain it constant. 

Figure 4-252. Wave amplitude variation as a function of distance in water-base mud and in oil-base mud (a) mud weight, 9 Ib/gal (b) mud weight, 17.9 Ib/galt. (Courtesy Petroleum Erigmeer International [108]. ...

While an increase or a decrease in amplitude may indicate degradation of the machine-train, this is not always the case. Variations in load, operating practices, and a variety of other normal changes also generate a change in the amplitude of one or more frequency components within the vibration signature. In addition, it is important to note that a lower amplitude does not necessarily indicate an improvement in the mechanical condition of the machine-train. Therefore, it is important that the source of all amplitude variations be clearly understood. 

What is not commonly known outside the NMR community is the relative difficulty in making accurate relative density measurements by NMR/MRI compared, for example, with making velocity measurements by NMR/MRI. This is because density measurements rely on the signal strength, which can be affected by any number of factors. In contrast, the most common way to measure flow velocity by NMR/MRI is to use the phase of the NMR signal rather than the amplitude, which vastly reduces its sensitivity to amplitude variations. 

The forms of equations 14 and 17 describing the deposition of the tracer on the ocean surface, ocean floor and into the historical layers of the sediments are all similar. However, the amplitude variations in the historical layers of sediment are attenuated considerably compared to variations in deposition on the ocean surface, i.e., at input, the attenuation being governed by the effective residence times of nuclides in sea water and in the mixed layer of the sediments. 

Figure 8. (A) Shell 8180 and 813C cycle from one sample from the Siwaliks of Nepal. Note that the calculated amplitude of SlsO change in the river water is 10%o if cool temperature is associated with the most positive shell 8180 value. The amplitude is larger (13.65%o) if the temperature association is reversed. Modified from Dettman et al. 2001. (B) Tooth enamel SlsO cycle from the Siwaliks of Pakistan, showing similar amplitude variations for older vs. younger teeth.

The diagrams in Fig. llc-f can be measured by the force probe method, when the amplitude and phase are measured as the tip approaches and retracts the surface vertically. In the non-contact range, both the amplitude and the phase retain their constant values (Fig. llc,e). When the tip enters the intermittent contact range (Zphase reduces almost linearly on approaching the surface. The deviation of the amplitude signal from a certain set-point value As is used by a feedback loop to maintain the separation Zc between the tip and sample constant, and hereby visualise the surface structure. When the surface composition is uniform, the amplitude variation is mainly caused by the surface topography. However, if the surface is heterogeneous, the variation in the amplitude can be affected by local differences in viscoelasticity [108-110 ] and adhesion [111] of the sample (Sect. 2.2.2). 

When X-rays interact with any kind of materials, absorption and phase shifts effects occur. Conventional X-ray radiography relies on the absorption properties of the sample. The image contrast is produced by a variation of density, a change in composition or thickness of the sample, and is based exclusively on the detection of an amplitude variation of X-rays transmitted through the sample itself. Information about the phase of X-rays is not considered. The main limitation of this technique is the poor intrinsic contrast in samples with low atomic number (i.e., the case of soft matter ) or in materials with low variation of absorption from point to point. 

It is also possible that one can re-interpret the Landau equation and write its amplitude variation by. 

In Fig. 5.3, computed Ae is also compared with the correlation proposed by Norberg (2003)- based on his experimental results. For his experimental facility, Rccri = 47 and in the range 47 < Re < 190 as3Tuptotic amplitude variation (r.m.s.) with Re is given by, Ae = ( + Whereas, in... 

Figure 1.29 (a-d) SAME curves on an (0111) oriented Zr single grain after potentiodynamic formation to the indicated formation potentials (10-40 V). The symbols referto the experimental data, the lines represent the fit results (SAME determination of the orientation angles). Significant amplitude variations and phase shift of the A curves with respect to the curves are... 

In the literature hard pulses and shaped pulses are usually treated as different entities such that any phase or amplitude modulation of hard pulses is neglected or assumed to be negligible whereas the phase and amplitude variation of a shaped pulse is always emphasized. The truth is that even hard pulses can have a significant phase and amplitude variation particularly at the extremes of their excitation bandwidth. For a comprehensive discussion the reader is referred to section 5.3.1. 

Capillary breakup method The capillary breakup method is based on Tomotika s theory [Tomotika, 1935, 1936]. The author was the first to investigate the development of Rayleigh s instabilities in cylinders of one fluid imbedded in another (see Pigs. 4.10 and 4.11) [Rayleigh, 1879]. The amplitude variations of the sinusoidal distortions, a, can be described by ... 

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