Data acquisition transient

While this approach increases speed, it is not generally recommended for vibration analysis. Overlap averaging reduces the accuracy of the data and must be used with caution. Its use should be avoided except where fast transients or other unique machine-train characteristics require an artificial means of reducing the data-acquisition and processing time. 

Repeated twisting of the spindle s tube or the solid shaft used in jackshafts results in a reduction in the flexible drive s stiffness. When this occurs, the drive loses some of its ability to absorb torsional transients. As a result, damage may result to the driven unit. Unfortunately, the limits of single-channel, frequency-domain data acquisition prevents accurate measurement of this failure mode. Most of the abnormal vibration that results from fatigue occurs in the relatively brief time interval associated with startup, when radical speed changes occur, or during shutdown of the machine-train. As a result, this type of data acquisition and analysis cannot adequately capture these... 

It is the essence of transient measurements that a certain perturbation is applied to the electrode and then the response is recorded as a function of time. Usually, the transition times are short (fractions of a second), and the transient measurements are performed very rapidly with automated data acquisition. 

Intermediate in the CppNbH -Fe(C0)c Reaction. A solution of 0.35 mmol Cp2NbHo in 1 ml CgDg was transferred to a serum-capped NMR tube and cooled to just above freezing. 0.15 ml Fe(C0) was added, the tube was inserted into the XL-100 spectrometer, and a program for kinetic study data acquisition was initiated a set of transients was accumulated for 30 sec and stored data acqui-... 

In the introduction to Volume 1 of this series, the founding editors, J. N. Pitts, G. S. Hammond and W. A. Noyes, Jr. noted developments in a brief span of prior years that were important for progress in photochemistry flash photolysis, nuclear magnetic resonance, and electron spin resonance. A quarter of a century later, in Volume 14 (1988), the editors noted that since then two developments had been of prime significance the emergence of the laser from an esoteric possibility to an important light source, and the evolution of computers to microcomputers in common laboratory use of data acquisition. These developments strongly influenced research on the dynamic behavior of the excited state and other transients. 

While new data acquisition techniques under development may significantly reduce the time and increase the precision of recording diffraction patterns, it is obvious that X-ray diffraction techniques will be restricted to the study of conformations and intermediates which are stable for periods that exceed the normal half-life of these transient species. It is therefore necessary to increase the lifetime of such species so that their three-dimensional structures may be determined in the same manner as a native enzyme. 

Wt-GFP was expressed in E. coli and purified as described in Ref. [4]. Time- and frequency resolved pump-probe transients were recorded with 40-fs, 400-nm excitation pulses and probe pulses with durations of approximately 40 fs throughout the visible spectral range. Since photo-conversion strongly alters the GFP response, rapid scan data acquisition was performed... 

For some mass spectrometers, such as TOF mass spectrometers, for reasons of data transfer speed and data storage capacity, the data acquisition system needs to accumulate data for a period of time in the summing memory, and forward the accumulated data to the data system. Each spectrum is added to the sum of the previous spectra so that a continuous summation process takes place. This type of data acquisition system is called digital signal averaging (DSA) or integrating transient recorder (ITR). Figure 3.8 illustrates the principle of mass spectrum acquisition with this type of system. 

The upper limit on D is set by the requirement for multiple data points during the transient response, while the lower limit results from the long times required to approach equilibrium. Thus, thinner films (hundreds of nanometers) are better for probing slower diffusion, while thicker film (micrometers) are better for faster diffusion. An electronics scheme capable of rapid data acquisition [98] would enable larger D values to be quantified based on following the rapid transients. 

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