Laser scattering technique

Komori, S., T. Kanzaki, Y. Murakami, and H. Ueda (1989). Simultaneous measurements of instantaneous concentrations of two species being mixed in a turbulent flow by using a combined laser-induced fluorescence and laser-scattering technique. Physics of Fluids A Fluid Dynamics 1, 349-352. 

C, shake flask-laser scattering technique, measured range 276.94-386.6 K, Ochi et al. 1996)... 

Laser-scattering techniques have been used in a variety of operational modes to size pharmaceutical aerosols. These may be listed as forward scattering, Fraunhofer diffraction, and laser Doppler velocimetry, in conjunction with either accelerating nozzles or acoustic excitation. 

The laser scattering technique is newly developed, and probably will be extremely valuable in quantitating the differences in embolic events during blood-material interactions, and thus potentially useful in elucidating the mechanisms responsible for these differences. 

Another set of analytical techniques (optocal-orimetric methods) is based on indirect measurement of the energy absorbed by the sample. Absorbed energy is transformed into kinetic energy of the sample particles followed by an increase in the local temperature of the sample. The resultant changes in pressure and refractive index can be measured by optoacoustic methods or by laser scattering techniques. 

CH Ochi, K., Saito, T., and Kojima, K., Determination of solubilities of polymers in solvents by a laser scattering technique. Fluid Phase Equil, 158-160, 847, 1999. 

Gamez G., Bogaerts A., Andrade E., and Hieftje G. M. (2004) Eunda-mental studies on a planar-cathode direct current glow discharge, Part I Characterization via laser scattering techniques, Spectrochim. Acta, Part B 59 435-447. 

Ahmad, S.R., Foster, V.G. and Reynolds D.M. (1993). Laser scattering technique for the non-invasive analysis of wastewater. SPIE Vol. 2092, Substance Detection Systems (pp. 353-359). Washington, DC SPIE - International Society for Optical Engineering. 

Flowever, in order to deliver on its promise and maximize its impact on the broader field of chemistry, the methodology of reaction dynamics must be extended toward more complex reactions involving polyatomic molecules and radicals for which even the primary products may not be known. There certainly have been examples of this notably the crossed molecular beams work by Lee [59] on the reactions of O atoms with a series of hydrocarbons. In such cases the spectroscopy of the products is often too complicated to investigate using laser-based techniques, but the recent marriage of intense syncluotron radiation light sources with state-of-the-art scattering instruments holds considerable promise for the elucidation of the bimolecular and photodissociation dynamics of these more complex species. 

A final example of laser measurement techniques is measurement of the velocity of fluid flow (79) (see Flow measurement). If a laser beam is directed into a transparent fluid, some of the light may be scattered with a frequency shift zy given by... 

The laser-Doppler anemometer measures local fluid velocity from the change in frequency of radiation, between a stationary source and a receiver, due to scattering by particles along the wave path. A laser is commonly used as the source of incident illumination. The measurements are essentially independent of local temperature and pressure. This technique can be used in many different flow systems with transparent fluids containing particles whose velocity is actually measured. For a brief review or the laser-Doppler technique see Goldstein, Appl. Mech. Rev., 27, 753-760 (1974). For additional details see Durst, MeUing, and Whitelaw, Principles and Practice of Laser-Doppler Anemometry, Academic, New York, 1976. 

Beri, R. G., Walker, J., Reese, E. T., and Rollings, J. E., Characterization of chitosans via coupled size-exclusion chromatography and multiple-angle laser light-scattering techniques, Carb. Res., 238, 11, 1993. 

T. Arakawa, Applications of laser light scattering techniques to molecular biology, Cell Technol., 15(5), 679 (1996). 

The advancement of the application of lasers in combination with the molecular beam technique has made a great impact in the understanding of primary photodissociation processes. For state-specific detection of small fragments, laser-induced fluorescence, multiphoton ionization, and coherent laser scattering have provided extremely detailed information on the dynamics of photodissociation. Unfortunately, a large number of interesting... 

Yeh and Keeler 244) extended the method of laser-scattering spectroscopy to probe systems undergoing rapid chemical reactions. They observed the spectral line broadening in light from a singlemode He-Ne laser scattered from multicomponent solutions, as a function of time. The experiment employed a pressure-scanned Fabry-Perrot interferometer and photon counting techniques. 

The elution character of the FFF techniques allows for it to be used in combination with other methods for further on-line or off-line characterization of the analytes (see Figure 12.1). FFF can be hyphenated with selective detection systems like mass spectrometry, multiangle laser scattering and can be combined with different separation techniques in multidimensional modes. In Figure 12.3, the trend in the number of published papers is reported. 

Hizukuri, S., Takagi, T. (1984). Estimation of the distribution of molecular weight for amylose by the low-angle laser-light-scattering technique combined with high-performance gel chromatography. Carbohydr. Res., 134, 1-10. 

The first data on polymer systems were collected via (laser-) light-scattering techniques [1] and turbidity measurements, further developed by Derham et al. [2,3]. Techniques based on the glass-transition of the polymer-blend constituents were also tested, such as DSC, Dynamic Mechanical Spectroscopy, and Dielectric relaxation [4]. Films made from solutions of... 

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