Peak amplitude

Some discontinuities may be identified by a conventional two-dimensional ultrasonic technique, from which the well-known C-scan image is the most popular. The C-scan technique is relatively easy to implement and the results from several NDE studies have been very encouraging [1]. In the case of cylindrical specimens, a circular C-scan image is convenient to show discontinuity information. The circular C-scan image shows the peak amplitude of a back-scattered pulse received in the circular array. The axial scan direction is shown as a function of transducer position in the circular array. The circular C-scan image serves also as an initial step for choosing circular B-scan profiles. The latter provides a mapping between distance to the discontinuity and transducer position in the circular array. 

The thermoelastic law, valid only within the elastic range of isotropic and homogeneus materials, relates the peak to peak temperature changes to the peak to peak amplitude of the periodic change in the sum of principal stresses. 

Gate Start and Width. Define the start position and width, in millimetres, of the gate used for defining the time interval in which the peak amplitude of the signal will be measured. 

Once the probe is set into the target, the acquisitions consist of the peak to peak amplitude, the time of flight and the frequency response of the back-reflected echo. 

The maximum permissible vibration, in mils (0.001 in.), during shop test at rated speed shall be equal to the square root of 20,000 divided by the sum of rated speed plus meeh-anieal and eleetrieal runout for the overhung rotor design. Only the aetual total measured runout may be subtraeted from the unfiltered peak-to-peak amplitude measured during testing to attain the shaft vibration. The meehanieal-plus-eleetrieal runout subtraeted from the unfiltered peak-to-peak amplitude shall not exeeed 0.5 mils regardless of total runout. 

Maximum continuous speed, 105 percent = Initial (lesser) speed at. 707 x peak amplitude (critical) Wg = Final (greater) speed at.707 x peak amplitude (critical) W2-/v,= Peak width at the half-power" point... 

To summarize the importance of the critical speed concept, one should bear in mind that it allows an identification of the operation region of the rotor-bearing system, probable mode shapes, and approximate locations of peak amplitudes. 

The power switch and rectifier ac-current loops contain very high trapezoidal current waveforms typical in PWM switching power supplies. These waveforms are rich in harmonics which extend far above the basic switching frequency. These ac currents can have peak amplitudes two to five times that of the... 

The AC component of the modulator/demodulator output is an indica tion of dynamic motion, or vibration. This signal provides data relating to the peak-to-peak amplitude, frequency, and form of the dynamic action of the observed surface. 

Typical magnetoconductance data for the individual MWCNT are shown in Fig. 4. At low temperature, reproducible aperiodic fluctuations appear in the magnetoconduclance. The positions of the peaks and the valleys with respect to magnetic field are temperature independent. In Fig. 5, we present the temperature dependence of the peak-to-peak amplitude of the conductance fluctuations for three selected peaks (see Fig. 4) as well as the rms amplitude of the fluctuations, rms[AG]. It may be seen that the fiuctuations have constant amplitudes at low temperature, which decrease slowly with increasing temperature following a weak power law at higher temperature. The turnover in the temperature dependence of the conductance fluctuations occurs at a critical temperature Tc = 0.3 K which, in contrast to the values discussed above, is independent of the magnetic field. This behaviour was found to be consistent with a quantum transport effect of universal character, the universal conductance fluctuations (UCF) [25,26]. UCFs were previously observed in mesoscopic weakly disordered... 

A" = peak amplitude of displacement w = 2Ttf (f = frequency of vibration) m = particle of mass being displaced and assuming a sinusoidal relation... 

A = action of cylinder, single (1) or double (2), or cross-sectional flow area of drum, ft peak amplitude of displacement cross-section flow area of first drum and second drum, respectively, fti cylinder bore, in. fti gas per min... 

Vibrations are characterized by their peak-to-peak amplitude at low frequencies or by their acceleration at high frequencies. Assuming that vibration is sinusoidal, the equation for motion is... 

What peak-to-peak amplitude (psi) of the pressure wave is necessary at bottom to get the required peak to peak value at surface Is our pulsing device suited for this job ... 

The pump noise frequency is varying around 8 Hz with a peak-to-peak amplitude of 20 psi. Can the signal still be detected Explain. 

As illustrated in Figure 43.11, the peak-to-peak amplitude (2A, where A is the zero-to-peak) reflects the total amplitude generated by a machine, a group of components, or one of its components. This depends on whether the data gathered is broadband, narrowband, or component. The unit of measurement is useful when the analyst needs to know the total displacement or maximum energy produced by the machine s vibration profile. 

As illustrated in Figure 44.42, a resonance peak represents a large amount of energy. This energy is the result of both the amplitude of the peak and the broad area under the peak. This combination of high peak amplitude and broad-based energy content is typical of most resonance problems. The damping system associated with a resonance frequency is indicated by the sharpness or width of the response curve, ci) , when measured at the half-power point. i MAX is the maximum resonance and Rmax/V is the half-power point for a typical resonance-response curve. 

Fig. 2.5.7 The ratio of the peak amplitudes, product/reactant, as a function of time with the data obtained from the system illustrated in Figure 2.5.5. Symbols squares, coil 1 triangles,...

The reference scan is to measure the decay due to spin-lattice relaxation. Compared with the corresponding stimulated echo sequence, the reference scan includes a jt pulse between the first two jt/2 pulses to refocus the dephasing due to the internal field and the second jt/2 pulse stores the magnetization at the point of echo formation. Following the diffusion period tD, the signal is read out with a final detection pulse. The phase cycling table for this sequence, including 2-step variation for the first three pulses, is shown in Table 3.7.2. The output from this pair of experiments are two sets of transients. A peak amplitude is extracted from each, and these two sets of amplitudes are analyzed as described below. 

Peak Amplitude Spectral Analysis Amplitude Based Pattern Recognition Spatial Averaging Directional Dependence Frequency Dependence Conventional Shear Wave ... 

With gain or phase margin, calculate proportional gain. Can also estimate the peak amplitude ratio, and assess the degree of oscillation. The peak amplitude ratio for a chosen proportional gain. Nichols chart is usually constructed for unity feedback loops only. 

Fig. 20. Electron spin resonance spectra of nitroxalkylcobalamin. (a) Spectrum before photolysis the high field line is broadened and therefore has a lower peak amplitude, (b) Expanded view of center line before photolysis showing no indication of additional hyperfine from methyl protons, (c) Spectrum of nitroxide photolysis product which has been freed from the cobalamin. (d) Expanded view of center line after photolysis now faintly showing proton hyperfine...

Slow-wave potentials also involve gradual depolarization of the cell membrane, but these depolarizations do not necessarily reach threshold. Therefore, the depolarization may simply be followed by repolarization back to the initial membrane potential. These slow "wave-like" potentials occur rhythmically and do not lead to smooth muscle contraction. The peak-to-peak amplitude of the slow-wave potential is in the range of 15 to 30 mV. Therefore, under the appropriate conditions, the depolarization phase of the slow-wave potential may, in fact, reach threshold. When this occurs, a burst of action potentials is generated, resulting in muscle contraction. 

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