Scanning time

More recently, the circular array was proposed to assess the reflectivity of cylindrical specimens [3]. First, a circular C-scan image was obtained. The total scan time was about 25 min., which does not include a relatively time consuming alignment of the specimen. From the circular C-scan image, circular B-scan profiles were chosen in specific planes. The transducer was a focused high frequency transducer with a center frequency of 25 MHz of the transducer bandwidth. This frequency corresponds to a wavelength of 0.11 mm and 0.25 mm in the Plexiglas specimen and the AlSi-alloy, respectively. Additional experimental parameters are presented in Table 1. 

Based on a preliminary set of acceptance criteria s developed by LM Glasfiber a standard data-set has been developed for each of the above mentioned set-ups, in order to minimize the scanning time. During the performance demonstration at LM Glasfiber the effective scanning time for a complete 21m wind turbine rotor blade based on the preliminary acceptance criteria s, was found to be less than hour. 

The coin-tap test is a widely used teclinique on thin filament winded beams for detection of disbonded and delaminated areas. However, since the sensitivity of this teclinique depends not only on the operator but also on the thickness of the inspected component, the coin-tap testing technique is most sensitive to defects positioned near the surface of the laminate. Therefore, it was decided to constructed a new scaimer for automated ultrasonic inspection of filament winded beams. A complete test rig illustrated in figure 6 was constructed in order to reduce the scanning time. While the beam rotates the probe is moved from one end to the other of the beam. When the scarming is complete it is saved on diskette and can then be evaluated on a PC. The scanner is controlled by the P-scan system, which enables the results to be presented in three dimensions (Top, Side and End view). 

Figure Bl.9.13. Time-resolved SAXS profiles diirmg isothennal crystallization (230 °C) of PET (the first 48 scans were collected with 5 seconds scan time, the last 52 scans were collected with 30 seconds scan time) calculated correlation fiinctions j(r) (nonnalized by the invariant 0 and lamellar morphological variables...

Geva E and Skinner J L 1998 Optical line shapes of single molecules in glasses temperature and scan-time dependence J. Phys. Chem 109 4920-6... 

Mapping of major constituents can be carried out in approximately 15-30 minutes of scanning per image. Minor constituents require 0.5-3 hours, and trace constituents require 3-10 hours. An example of a dot map of zinc at concentrations in copper as low as 1% is shown in Figure 5 6 hours of scan time was needed to produce a dot map at this level. 

The high sensitivity of the MS [160] makes it a particularly appropriate tool for the investigation of nucleation and growth processes, since it is possible to measure rates during the early part of the reaction using small samples or individual crystals. The influence of residual gases [160] on the initiation of reaction can also be determined. Short scan times enable very rapid reactions e.g. detonations, to be studied, and it is also possible to measure simultaneously the rate of evolution of several different product molecules. 

Figure 4. Improvement in sensitivity with the CAT. PFA and a reference peak at m/e 315. The observed improvement in signal-to-noise ratio results from the longer total scanning time and also the fact that many sweeps are made during this time. The overall improvement in signal-to-noise ratio depends on the detailed power spectrum of the noise (9). Resolution 12,000 here and for all following time averaged spectra...

Fortunately, an alternative method of excitation exists, instead of the sequential excitation of nuclei by the slow variation of the magnetic field. This involves the application of a short but intense radiofrequency pulse extending over the entire bandwidth of frequencies in which the nuclei to be observed resonate, so that all the nuclei falling within the region are excited simultaneously. As a result the total scan time is made independent... 

The amount of contrast material required for CTA is comparable to that used for conventional contrast-enhanced CT imaging. The amount of scanning time required for a CTA examination of the head and neck, such as is usually performed for acute... 

In recent years, infrared spectroscopy has been enhanced by the possibility of applying Fourier transform techniques to it. This improved spectroscopic technique, known as Fourier transform infrared spectroscopy (FTIR), is of much greater sensitivity than conventional dispersive IR spectroscopy (Skoog West, 1980). Moreover, use of the Fourier transform technique enables spectra to be recorded extremely rapidly, with scan times of only 0-2 s. Thus it is possible to record spectra of AB cements as they set. By comparison, conventional dispersive IR spectroscopy requires long scan times for each spectrum, and hence is essentially restricted to examining fully-set cements. 

Mode Interface Spray voltage Sheath gas Auxiliary gas Capillary temperature Manifold temperature Collision gas Total scan time QIMS resolution voltage added Q3MS resolution voltage added Parent masses... 

GC-MS analysis is schematically indicated in Figure 7.13. In GC-MS data collection, account should be taken of the fact that GC peaks eluting from a capillary column are only a few seconds wide, which imposes fast scan times. As most compounds analysed by GC-MS are low-MW (<800 Da), a relatively short... 

Point scanning time domain FLIM implementations... 

Optionally, adjust modulation, gain, scan time, damping. 

This approach is very straightforward, is not restricted to reversible systems, and so has been employed to study a wide range of electrochemical systems. Scan times are very low, even as low as 15 ms, hence N can be large without experimental drift becoming a problem. Sensitive spectra with stable baselines are thus quickly and simply obtained. 

Volumetric and morphological brain measurements are made with MRI. Modern MRI can produce detailed, high-contrast images of the entire brain in relatively short scan times with no invasive procedures or radioactivity. Thus, it is the modality of choice for detailed neuroanatomic studies in various neuropsychiatric disorders. Many groups have addressed the challenge of how to quantify subtle structural characteristics in the brain that appear to differ consistently between comparison groups. Methods such... 

The microcomputer should incorporate a VDU and have high-density colour graphics capability (up to 1760(x) x 1280(y)). This enables IR-spectra to be displayed on the screen of the VDU with excellent definition so that comparisons, the results of scale expansions and other spectral manipulations can immediately be seen. Parameters such as range, scan time, data point interval, etc., are set and monitored under microprocessor control and stored along with the spectrum. During the scanning of a sample, several thousand data points may be collected and stored in RAM which should be able to accommodate and display at least three spectra simultaneously. There is a wide range of manipulations that can be performed by the analyst on stored spectra, e.g. 

Fourier transform infrared spectroscopy spectrometers achieve much higher signal-to-noise ratios in comparable scanning times. 

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