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Polarized measurements

Much attention has been given to the analysis of OH stretching bands of micas occurring in an isolated region of the spectrum ranging from about 3750 to 3550 cm (Farmer 1974). Using polarized radiation, the pleochroic scheme of IR absorption bands, measured on oriented crystal sections, makes it possible to impose defined constraints on the orientation of the OH dipoles. In a fundamental polarised IR study, Tsuboi (1950) determined the position of the H atom in the structure of muscovite. The variation of absorption intensity of the OH stretching band with the direction of the electric vector of [Pg.359]


It is advantageous if the laser system pemiits rotation of the optical polarization. Detached electrons correlated witii different final electronic states of the neutral molecule will generally be emitted with different angular distributions about the direction of polarization. Measurement of the angular distribution helps in the interpretation of complex photoelectron spectra. The angular distribution/(0) of photoelectrons is [50]... [Pg.804]

The value obtained as a result of a polarization measurement for sucrose is expressed as "pol" or "polarization" or "degrees pol" and not as percentage of sugar, but it is considered to closely approximate the sugar content. [Pg.9]

One of the best available texts describing the principles of Raman scattering from crystals. Includes factor group calculations, polarization measurements, force constant calculations, and many other aspects of crystal physics. [Pg.440]

From a practical sense, MOKE is a versatile technique it is an optical method the polarization measurement is fairly easy to do the necessary optical components are common and relatively inexpensive and it has no intrinsic vacuum requirements. [Pg.725]

Many other measures of solvent polarity have been developed. One of the most useful is based on shifts in the absorption spectrum of a reference dye. The positions of absorption bands are, in general, sensitive to solvent polarity because the electronic distribution, and therefore the polarity, of the excited state is different from that of the ground state. The shift in the absorption maximum reflects the effect of solvent on the energy gap between the ground-state and excited-state molecules. An empirical solvent polarity measure called y(30) is based on this concept. Some values of this measure for common solvents are given in Table 4.12 along with the dielectric constants for the solvents. It can be seen that there is a rather different order of polarity given by these two quantities. [Pg.239]

Closely related to water solubility as a polarity measure is the partition coefficient of a substance between water and an immiscible organic solvent. Most commonly the organic solvent is selected to be n-octanol, and the symbol P is given to the octanol/water partition coefficient. Then log P is a quantitative measure of hydro-phobicity and, therefore, of nonpolarity. Table 8-3 gives log P values for many of... [Pg.400]

Another solvatochromic polarity measure, (30), is the transition energy for compound 8, which is 2,6-diphenyl-4-(2,4,6-triphenylpyridinio)phenolate, also referred to as Dimroth-Reichardt s betaine. [Pg.437]

Table 3.5-1 Solvent polarity measurements for some ionic liquids. Table 3.5-1 Solvent polarity measurements for some ionic liquids.
The relative importance of the hafide anion - HO - Cell interactions can be inferred from application of the Taft-Kamlet-Abboud equation to the UV-Vis absorbance data of solvatochromic probes, dissolved in cellulose solutions in different solvent systems, including LiCl/DMAc and LiCl/N-methyl-2-pyrrolidinone [96]. According to this equation, the microscopic polarity measured by the indicator, Ej (indicator), in kcalmol is correlated with the properties of the solvents by Eq. 1 ... [Pg.117]

Figure 26. Bench for s- and p- polarization measurements of the losses due to birefringence in s- and p- polarization (dex scale). The cross in the left image is due to the mirror support. Figure 26. Bench for s- and p- polarization measurements of the losses due to birefringence in s- and p- polarization (dex scale). The cross in the left image is due to the mirror support.
Of the five bending vibrations of the Sg molecule three are Raman active (V2, Vg, Vii) and two are IR active (V4, Vg). Most of the Raman active modes in the crystal could clearly be resolved in spectra at low temperatures and by polarization measurements. For example. Fig. 6 shows the Raman active factor group components of the Vg mode obtained at three different polarizations. In Fig. 7 an analogous IR spectrum is presented. [Pg.52]

Calibration. The quantitative transformation of polarization measurements into binding takes advantage of unique features of the FLPEP system. Weber s Law of the additivity of anisotropy is given by... [Pg.66]

Advantages. Polarization measurements permit continuous binding analysis with subsecond resolution if required. When applied in stop-flow mixing conditions the technique has the best time resolution of the methods presently available. [Pg.67]

Molecular Rotational Diffusion. Rotational diffusion is the dominant intrinsic cause of depolarization under conditions of low solution viscosity and low fluorophore concentration. Polarization measurements are accurate indicators of molecular size. Two types of measurements are used steady-state depolarization and time-dependent (dynamic) depolarization. [Pg.183]

In principle, pulsed excitation measurements can provide direct observation of time-resolved polarization decays and permit the single-exponential or multiexponential nature of the decay curves to be measured. In practice, however, accurate quantification of a multiexponential curve often requires that the emission decay be measured down to low intensity values, where obtaining a satisfactory signal -to-noise ratio can be a time-consuming process. In addition, the accuracy of rotational rate measurements close to a nanosecond or less are severely limited by tbe pulse width of the flash lamps. As a result, pulsed-excitation polarization measurements are not commonly used for short rotational periods or for careful measurements of rotational anisotropy. [Pg.189]

The trends of behavior described above are found in solutions containing an excess of foreign electrolyte, which by definition is not involved in the electrode reaction. Without this excess of foreign electrolyte, additional effects arise that are most distinct in binary solutions. An appreciable diffusion potential q) arises in the diffusion layer because of the gradient of overall electrolyte concentration that is present there. Moreover, the conductivity of the solution will decrease and an additional ohmic potential drop will arise when an electrolyte ion is the reactant and the overall concentration decreases. Both of these potential differences are associated with the diffusion layer in the solution, and strictly speaking, are not a part of electrode polarization. But in polarization measurements, the potential of the electrode usually is defined relative to a point in the solution which, although not far from the electrode, is outside the diffusion layer. Hence, in addition to the true polarization AE, the overall potential drop across the diffusion layer, 9 = 9 + 9ohm is included in the measured value of polarization, AE. ... [Pg.92]

Figure 15.2 shows polarization curves for hydrogen evolution at electrodes of different metals in acidic electrolyte solutions. The results of polarization measurements are highly sensitive to the experimental conditions, in particular to the degree of solution and electrode surface purification for this reason, marked differences exist among the data reported by different workers. The curves shown still provide the correct picture of the common features. [Pg.264]

FIGURE 32.2 Scheme of a four-electrode system for polarization measurements at an ITIES comprising a potentiostat (POT), two reference electrodes connected to the cell by means of Luggin capillaries (REl, RE2), and two counter electrodes (CEl, CE2). The planar ITIES is formed at the edge of a round hole in a glass barrier between the spaces for the aqueous (water) and the organic (org) phases. [Pg.613]

Irradiation of an ITIES by visible or UV light can give rise to a photocurrent, which is associated with the transfer of an ion or electron in its excited state. Alternatively, the photocurrent can be due to transfer of an ionic product of the photochemical reaction occurring in the solution bulk. Polarization measurements of the photoinduced charge transfer thus extend the range of experimental approaches to... [Pg.617]


See other pages where Polarized measurements is mentioned: [Pg.1190]    [Pg.2788]    [Pg.318]    [Pg.2431]    [Pg.85]    [Pg.407]    [Pg.82]    [Pg.404]    [Pg.434]    [Pg.443]    [Pg.521]    [Pg.548]    [Pg.498]    [Pg.420]    [Pg.10]    [Pg.53]    [Pg.215]    [Pg.216]    [Pg.195]    [Pg.195]    [Pg.197]    [Pg.265]    [Pg.612]    [Pg.613]    [Pg.613]    [Pg.168]   
See also in sourсe #XX -- [ Pg.114 ]




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Applications and Results of Polarization Measurements

Asymmetries and polarization measurements at the Z peak

Continuous polarization measurements

Corrosion Rate Measurement by Fitting Polarization Curve to Wagner-Traud Equation

Corrosion Rate Measurement by Linear Polarization

Cross polarization quantitative measure

Cross-polarization-magic angle measurements

Cyclic potentiodynamic polarization measurements for localized corrosion

Dynamic nuclear polarization measurement

Electrochemical techniques linear polarization measurements

Electrochemical techniques polarization measurements

Electrodes polarization measurement

Empirical Parameters of Solvent Polarity from Kinetic Measurements

Empirical Parameters of Solvent Polarity from other Measurements

Empirical polarity measures

Experimental Measured Polarization Curves

Fluorescence measurements, polarized

Fluorescence polarization anisotropy measurement

Fluorescence polarization measurements

Fluorescence polarization measurements interfaces

Fractional polarity, surface tension measurement

Galvanostatic polarization measurement

Interpretation polarization measurement

Iron-base alloys polarization measurements

Linear polarization measurements

Linear polarization resistance measurement

Measurement of polarity

Measuring Polarization

Membrane fouling concentration polarization measurement

Nickel-base alloys polarization measurements

Nondemolition polarization measurement

Nonlinear optics continuous polarization measurements

Polar regions, stratospheric measurements

Polar stratosphere, atmospheric measurements

Polarity contact angle measurements

Polarity index measurement

Polarity, universal measure

Polarization measurement

Polarization measurement

Polarization measurements, nonlinear optics

Polarization properties measurement techniques

Polarization resistance measurements

Polarization resistance measurements, complications

Polarization resistance techniques corrosion-rate measurements

Polarization-Modulation Spectrometry and its Application to Reflection-Absorption Measurements

Polarization-modulation measured

Polarization-modulation measurement

Polarized light reflectance measurements

Polarized light reflectance measurements polarizers

Polarizers electrooptic measurements

Potentiodynamic polarization measurements

Potentiodynamic polarization measurements for localized corrosion

Potentiodynamic polarization resistance measurements (ASTM

Potentiostatic polarization measurement

Raman spectroscopy polarized measurements

Reference electrodes experimental polarization measurements

Resonance energy transfer polarization measurements

Solid-state polarization measurements

Solvatochromic polarity measures

Stainless steel, corrosion measurement polarization resistance

Steady-State Polarization Measurements

Steady-state polarization anisotropy measurements

Stokes parameters polarization measurement

Time-resolved fluorescence polarization measurements

Transport measurements, solids polarization

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