A study of internal rotation in polymers by the analysis of the asymmetry in the EPR spectra

Summary In our opinion the work reported above clearly demonstrates how an examination of the anisotropy in the EPR lines obtained from oriented an isotropic polymers can yield a lot of valuable data on the structure and internal rotation in polymers, particularly information about changes taking place during polymorphic phase transitions. For example, the fact that changes observed in the shapes of spectra obtained from polycrystalline teflon are quite different from those obtained in teflon films (the experimental data relate to the crystalline phase exclusively [15]) indicate that the crystal structures of the two materials must somehow differ. This argument is further supported by the fact that the recombination rates of radicals are different in the two materials [16]. A more rigorous analysis of the asymmetry in the singlet line would obviously provide certain quantitative data as to how complete is the alignment of the polymeric chains and what kind of angular distribution persists. We did detect a relationship between the shapes of the EPR spectrum and the amount by which the film is stretched (thickness) but have not done any systematic work on this problem.Translated from Zhurnal Strukturnoi Khimii, Vol. 3, No. 1. pp. 21–27, January–February, 1962     

Hydrogen diffusion in titanium at room temperature

The diffusion of hydrogen in technically pure VT1-00 titanium is studied at room temperature under conditions of hydrogen penetration from a glow discharge plasma. Hydrogen penetration occurs under conditions of hydride phase growth. The diffusion coefficients of hydrogen in titanium at room temperature are estimated.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 43–47, March, 1982.     

Elements de la théorie de catégories polyadiques

Sans résumé Presented by J. D. Monk.     

Statistics of bremsstrahlung. II

A calculation is made of coefficients (which are linear and nonlinear in the number of photons) appearing in the equations that determine the evolution of the mean and the variance of the number of bremsstrahlung photons emitted in Born scattering of electrons by Coulomb potentials. The effect of electron injection conditions upon the consequences of the saturation produced by increasing the magnetic field is discussed.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 7–11, December, 1978.The author thanks V. L. Bonch-Bruevich, B. A. Veklenko, and M. V. Fedorov for discussions of this work.