Effect of polymetaphenylene isophthalamide (phenylon) structure on the properties of an antifriction material

The relationship between phenylon structure and the friction properties of a phenylon-based material is established using the data of friction tests, x-ray analysis, and electron microscopy. It is shown that amorphization of the binder structure leads to a change in the coefficient of friction and to a displacement of the zone of maximum operating temperatures in the direction of higher values.Institute of Hetero-Organic Compounds, Academy of Sciences of the USSR, Moscow. Translated from Mekhanika Polimerov, Vol. 5, No. 2, pp. 201–206, March–April, 1969.     

Relative molecular diffusion

We study both analytically and numerically the motion of a passive floating admixture subject to molecular collisions in a random velocity field. Within the framework of the one-dimensional model, we study the phenomena of relative molecular diffusion and the closely related fluctuations of the density of a cluster of particles that were initially located in the same physically infinitesimal volume. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 43, No. 4, pp. 456–467, September, 2000.     

Organosilicon ethers of ricinoleic acid

Russian Chemical Bulletin - Interaction of vinyl trichlorosilane with sodium salt of ricinoleic acid is investigated. It is established that the composition and structure of silicon-containing...     

Derivation of the probability distribution of velocities of a detector-recorded brownian particle

The probability distribution of velocities in the given space region (detector) is found for particles of a passive admixture in a stream of external gas. Since direct calculation of the above probability density involves significant difficulties, the solution is based on the classical problem of the probability distribution of coordinates and velocity of a Brownian particle at a fixed time. Analyzing dependence of the solution on the parameters of the initial problem, we obtain conditions under which the assumptions on the character of particle motion hold true. State University, Nizhny Novgorod, Russia. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 41, No. 10, pp. 1301–1313, October 1998.     

ELECTRON SPIN RESONANCE OF TRIPLET STATES AND FREE RADICALS APPEARING IN PORPHYRINS, AROMATIC AMINO-ACIDS AND PROTEINS UNDER THE EFFECT OF LIGHT

Abstract— The electron paramagnetic resonance (EPR) of the triplet excited state of solutions of a series of porphyrins and aromatic amino-acids has been studied at 77°K. It has been shown that for some of the compounds it is possible to observe EPR for transitions with δ M =±1, ±2.
It has been shown that photoreactions in solid solutions of porphyrins and aromatic amino-acids proceed through the triplet excited state.
Reactions of photosensitized deamination of aliphatic amino-acids in solid aqueous solutions at 77°K by aromatic compounds have been studied.     

Quasibinary amorphous phase in a three-dimensional system of particles with repulsive-shoulder interactions

We report a computer-simulation study of the equilibrium phase diagram of a three-dimensional system of particles with a repulsive-step potential. Using free-energy calculations, we have determined the equilibrium phase diagram of this system. At low temperatures, we observe a number of distinct crystal phases. However, under certain conditions the system undergoes a glass transition in a regime where the liquid appears thermodynamically stable. We argue that the appearance of this amorphous low-temperature phase can be understood by viewing this one-component system as a quasibinary mixture.     

Optimization of conditions for the extraction of antioxidants from solid parts of medicinal plants

The extraction of phenolic antioxidants from solid plant raw materials (bark and roots) under the action of an electric current was studied. A relationship between the amount and antioxidant activity of extracted phenolic compounds with the particle size and the procedure of grinding plant raw material was found. The most complete extraction of phenols was reached in experiments with ground samples. The resulting extracts from the bark of arrowwood (Viburnum opulus L.) and the root of burnet (Sanguisorba officinalis L.) were superior to the extracts obtained by circulation extraction in a Soxhlet extractor in terms of the antioxidant activity, and they increased the stability of sunflower oil to oxidation by a factor of 2–3.