Characterization optical methods

We present two optical methods for characterizing wire surfaces. These methods allow us to measure the roughness and the correlation length of the surface. It is also possible to identify qualitatively, at a glance, the variations of the roughness along a wire or among its different zones. 

B1.22 Surface characterization and structural determination optical methods... 

Jenngins, B. R. Electro-Optic Methods for Characterizing Macromolecules in Dilute Solution. Vol. 22, pp. 61—81. 

Janeschitz-Kriegl, H. Flow Birefrigence of Elastico-Viscous Polymer Systems. Vol. 6, pp. 170-318. Jenkins, R. and Porter, R. S. Upertubed Dimensions of Stereoregular Polymers. Vol. 36, pp. 1-20. Jenngins, B. R. Electro-Optic Methods for Characterizing Macromolecules in Dilute Solution. Vol. 22, pp. 61-81. 

The multiphase fluid systems of interest are often opaque, and thus noninvasive techniques based on optical methods or using laser beams are not effective. Various experimental techniques are available and continue to be developed to characterize opaque multiphase flows. 

The computer age has brought about considerable innovation in the operation of laboratory instrumentation. One consequence of this is the wider acceptance and utilization of the optical microscope as a quantitative analytical instrument. A brief literature survey illustrates the diversity of disciplines and optical methods associated with the development of computer interfaced optical microscopy. This is followed by a description of how our methods of fluorescence, interferometry and stereology, nsed for characterizing polymeric foams, have incorporated computers. 

Clark H.A., Kopelman R., Tjalkens R., Philbert M.A., Optical Nanosensors for Chemical Analysis inside Single Living Cells. 1. Fabrication, Characterization, and Methods for Intracellular Delivery of PEBBLE Sensors, Anal. Chem. 1999 71 4831— 4836. 

Optical methods are a perfect tool to characterize interaction processes between a sensitive chemical or bio polymer layer and analytes1. Time-resolved measurements of this interaction process provide kinetic and thermodynamic data. These types of sensors allow the monitoring of production processes, quantification of analytes in mixtures and many applications in the area of diagnostics, biomolecular interaction processes, DNAhybridization studies and evenprotein/protein interactions2,3. 

Clark HA, Hoyer M, Philbert MA, Kopelman R (1999) Optical nanosensors for chemical analysis inside single living cells. 1. Fabrication, characterization, and methods for intracellular delivery of PEBBLE sensors. Anal Chem 71 4831 1836... 

According to the definitions given above, semiconductors are characterized by Eg 0. Inorgaific materials are classified as either semiconductors or insulators if < 3 eV or E g > 3 eV, respectively. However, the MOMs scientific community often refers to insulators for E g 0.1-0.2 e V, which could also be defined as narrow gap semiconductors. Eg can be experimentally determined by optical and transport methods. However, the experimental Eg values obtained by optical methods, opt e.g., by means of absorption/rellection experiments, may differ from those derived... 

The lifetime of the RSSR radical anions is usually very short on the microsecond timescale in water. However, they have been detected and characterized by time-resolved optical methods. In one early study, y irradiation of matrices containing alkyl and aryl disulfides provided spectroscopic evidence for the formation of the corresponding radical anions. Subsequently, the formation of RSSR radical anions has been well documented, particularly by EPR, flash photolysis, and pulse radiolysis. In fact, 2a/ a three-electron bonded radical anion species, particularly from sulfur compounds, constitute significant and interesting intermediates. The RSSR radical anions may be obtained from different approaches. One is by one-electron reduction of disulfides (equation 75), such as by pulse radiolysis. However, the most common approach is by association of RS and RS (equation 79). ... 

The various techniques available for structural characterization may be grouped under the following categories optical methods, diffraction methods, electron microscopic... 

Rates of lateral diffusion of membrane components have also been determined using optical methods. The early experiments of Frye and Ediden16 demonstrated lateral motion of fluorescent-labeled surface antigens in heterokaryons of mouse and human cells. They observed intermixing of fluorescent-labeled antibodies against mouse cell and human cell antigens. Optical methods may also be characterized as either transient or steady state. The use of fluorescence correlation spectroscopy as... 

Despite the success of purely optical methods such as luminescence and absorption in studying shallow energy levels, they are seldom used for characterization of deep states. This is mainly because the deeper levels of interest are usually nonradiative ones or killer centers for which such techniques are not applicable. In addition, the deep position within the energy gap means optical experiments must be performed in the infrared where... 

Petrographic Studies. Polished thin sections were examined by optical methods to determine original mineralogy and alteration phases. The sections were taken and oriented in such a manner to allow comparison of the microscopic mineralogy with the results of the autoradiography experiments The shale was too fine-grained to be characterized in detail. 

The change in the optical absorption of et7 with time (at 77 K) is shown in Fig. 5. It can be seen that electrons stabilized in shallower traps decay more rapidly due to which, in the course of the reaction, the absorption spectra shift steadily to the short-wavelength region, and the rate of the change of the optical density depends on the wavelength. This somewhat hinders the quantitative analysis of the kinetic data obtained for reaction (4) by the optical method. At the same time, the width and the shape of the EPR lines of et7 remain unchanged as kinetic measurements are made. This makes the analysis of the kinetic data much simpler since, in this case, the amplitude of the et7 EPR spectrum can be taken directly as a value characterizing the concentration of etr. For this reason most of the kinetic measurements for reaction (4) have been made by the EPR method. 

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