Laser methods, comparison between

An experimental method based on the theories for rainbow phenomena has been applied to the measurement of droplet size and velocity and to the detection of non-sphericity.[7] In this method, a comparison between two droplet diameters is deduced from two different optical interference patterns observed in a rainbow that is created by a droplet scattering laser light. Once a rainbow pattern is... 

For the sake of comparison and mutual validation of methods for measuring large follow-up reaction rate constants, it is interesting to apply different methods to the same system. Such a comparison between high-scan-rate ultramicroelectrode cyclic voltammetry, redox catalysis, and laser flash photolysis has been carried out for the system depicted in Scheme 2.25, where methylacridan is oxidized in acetonitrile, generating a cation radical that is deprotonated by a base present in the reaction medium.20... 

COMPARISON BETWEEN THE VALUES OF THE LASER SPECTRAL BANDWIDTH AS OBTAINED BY DIFFERENT METHODS.(a) ... 

Table I provides a schematic comparison between photo-sensor, laser, and ultrasonic methods, the different sensor systems being considered in more detail below.

A full comparison of the aforementioned methods of obtaining TRES has not hitherto been carried out, presumably because of the time involved in collecting the requisite number of decay curves with conventional single-photon counting instm-ments. With highly intense, S MHz laser pulses used as an excitation source data accumulation can be achieved rapidly and it is worthwhile describing a comparison between the two methods of obtaining TRES. 

A modified mechanism has been proposed for formation of the M—92 and M—106 ions in the mass spectra of carotenoids (see Scheme 1). Further resonance-enhanced laser Raman spectra of retinal derivatives have been reported.A comparison between various semi-empirical methods for the calculation of -carotene MO s has appeared. A better correlation between the u.v. spectrum and theoretical predictions is claimed by Suzuki et... 

In the case of cytochrome cdi (Cyt cdi) found in many facultative, anaerobic denitrifying bacteria, the SERRS spectroscopy has been used to obtain preliminary heme structure/environment comparisons between cyt cdx from two bacteria sources. Pseudomonas and Paracoccus. The difficulty encountered in preparing sufficient quantities of cyt cdi, can be thus solved by the low product consuming SERRS method. By exciting selectively with the 514.5 nm and 460 nm lines of an Ar laser, it is possible to produce successively an enhancement of RR scattering of reduced heme c, see Fig. 34, and heme di, see Fig. 35, in the protein complexes (3 x 10 M) adsorbed on Ag at —0.6 V vs. SCE. A comparison between the SERRS spectra of cdi proteins from the bacteria suggests differences in the heme chromophore and peripheral substituents. 

Fig. 5.10 Comparison between the conventional Rabi method (a) and its laser version (b)...

The main part of the book presents various applications of lasers in spectroscopy and discusses the different methods that have been developed recently. Chapter 6 starts with Doppler-limited laser absorption spectroscopy with its various high-sensitivity detection techniques such as frequency modulation and intracavity spectroscopy, cavity ring-down techniques, excitation-fluorescence detection, ionization and optogalvanic spectroscopy, optoacoustic and optothermal spectroscopy, or laser-induced fluorescence. A comparison between the different techniques helps to critically judge their merits and limitations. 

Summarizing the strengths of the approximate QD method, it reflects the dominant wave packet motions quite well, while the intensities cannot be reproduced exactly. Nevertheless, the comparison between the exact QD and the approximate QD method demonstrates that the latter method enables an efficient study of the dynamics that are induced with different laser pulse parameters even for larger molecules. 

For comparison between the analysis methods the results of laser diffraction and wet sieving were imported in a commercial program for matrix calculation and presentation in figures 5-8. 

Comparison between scaled theoretical and experimental one-electron Lamb shifts, expressed as deviations from the theoretical mjjn. The upper horizontal line for each ion is Erij son s theory and the lower horizontal line is Mohr s theory and S is the average of the two. The experimental data are labelled by the method of measurement according to (0) microwave resonance (a) anisotropy measurement (+) quench-rate measurement ( ) laser resonance. The dashed lines are the Borie corrections to the theoretical values. (From Drake )... 

Three strong lines of Ru XXXIII and Rh XXXIV have been identified in laser produced plasmas [11]. The intercombination line 3s Sq-3s3p P has not been observed but systematic comparisons between experiment and MCDF calculations lead to accurate wavelength predictions [12]. The energy levels of all (n = 3) configurations are calculated by relativistic model potential methods [13] and by the relativistic parametric potential method [14], but... 

A detailed description of the laser-excited vibrational fluorescence method and further results on relaxation processes in methane, including V - R transfer, have been given in reference In this paper, too, a comparison is made between the experimentally obtained F - F rates and calculations for the repulsive intermolecular potential responsible for these transitions. 

The luminescence of diamonds is related to various defects in its structure. Almost always, luminescence centers in diamonds are related to N atoms. It is logical, because the atomic radii of C and N are nearly equal (approximately 0.77 A). Luminescence spectroscopy has proven to be the most widely used method in studies of diamonds even in comparison with optical absorption, ESR, IR and Raman spectroscopies. Himdreds of spectra have been obtained, fluorescence characteristics enter into diamond quality gemological certificates, a wide range of electronic and laser applications are based on diamond optical properties in excited states nitrogen center aggregation is controlled by the residence time of diamond in the mantle, distinction between natural... 

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