Refraction of Gases

Bond Refractions Deduced from Molecular Refractions of Gases... 

Index of Refraction of Air, 10-253 Index of Refraction of Gases, 10-254 Index of Refraction of Inorganic Crystals,... 

The transition between crystalline and amorphous polymers is characterized by the so-called glass transition temperature, Tg. This important quantity is defined as the temperature above which the polymer chains have acquired sufficient thermal energy for rotational or torsional oscillations to occur about the majority of bonds in the chain. Below 7"g, the polymer chain has a more or less fixed conformation. On heating through the temperature Tg, there is an abrupt change of the coefficient of thermal expansion (or), compressibility, specific heat, diffusion coefficient, solubility of gases, refractive index, and many other properties including the chemical reactivity. 

Xiao, G. Z. Adnet, A. Zhang, Z. Sun, F. G. Grover, C. P., Monitoring changes in the refractive index of gases by means of a fiber optic Fabry Perot interferometer sensor, Sens. Actuators A Phys. 2005, 118, 177 182... 

Thus the value of the dielectric constant at the sample/metal interface determines the shift of the resonance. When adsorption of molecules at the metal surface results in the change of the refractive index or of the local value of the dielectric constant, the change of reflectivity is observed. This phenomenon has been used as the mechanism for detection of gases (Fig. 9.18a) and of adsorbed biomolecules (Fig. 9.18b). The depth of penetration of the surface plasmon is comparable to that of the evanescent field, that is, 100-500 nm for the visible-near infrared range. 

R. C, Burns, C. Graham, and A. R. M. Weller. Direct measurement and calculation of the second refractivity virial coefficients of gases. Molec. Phys., 59 41-64 (1986). 

This theory has revealed a powerful tool for the interpretation of a wide class of phenomena, including the optical rotatory power, the refractive index and the stopping power of gases, the Stark effect, the long-range intermol-ecular forces, and so on,... 

Ramaswamy and Watson (1936) also reported Rx s for a number of other simple molecules the bond refractions which may be inferred from these are included in Table 9, along with miscellaneous data deducible from measurements cited by Buckley and Maryott (1953), incidentally while listing dielectric polarizations and dipole moments of gases. (Except where indicated, the bond values in Table 9 refer to the... 

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