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1. Guide-vane units of the types tested can increase the throw of a jet created by a propellerby a factor of 1.3–1.8 for the same drive power. The use of distributor units to untwist the jet is inadvisable for economic and health reasons. 2. To analyze a jet untwisted by guide-vane units we can use the equation for untwisted jets with the coefficients α and β0. 3. For open-pit ventilators of limited size, it is advisable to get the required throw of the jet by increasing the number of guide vanes in the unit and reducing their width.

The construction and operating principles of a heavy-current linear induction accelerator yielding 3-MeV electrons and pulse currents up to 200 A are described. Results obtained on one section of this accelerator are presented. The electron current is 180 A (pulsed) with an energy of 485 keV; the pulse duration at a level of 0.95 is 0.35 μsec.

It is proved that if the Taylor coefficients of an entire transcendental function change sign sufficiently infrequently, then such a function increases on a positive ray in the same way as in the whole plane.

It was experimentally demonstrated that cholinesterase activity increases in the gray matter of the cerebral hemispheres in tetanus and dysentery intoxications. However, there is no change in its activity in pneumococcal mococcal intoxication. The activity of the enzyme does not change in the cerebellum in tetanus and dysentery intoxications. The increase in activity of cholinesterase in all the above cases is proved statiscally.

CONCLUSIONS (1) It has been found that the symmetrical structure of a polyoxadiazole is responsible for the formation of spherulitic structures, which account for the poor strength characteristics of polyoxadiazole films. (2) It is shown tha~ poly-(p,p'-diphenyloxide)-l,2,4-(4-phenyl)triazole, obtained by modification of poly-(p,p'-diphenyloxide)-l,3,4-oxadiazole, has a fibrillar structure and fairly good strength characteristics, and can be processed. Translated by E. O. PHILLIPS

The paper deals with the study, by a 4-probe method, of semiconductor layers which are non-uniform in depth. The appropriate boundary conditions in electrodynamics are solved and equations are obtained which enable the average values of the electric conductivity to be calculated from the results of 4-probe measurements. It is shown how to use the equations to measure the surface conductivity of semiconducting layers and to determine how this quantity varies.

A large group of scholars of the Institute of Government and Law, USSR Academy of Sciences, jointly with personnel of the Institute of Philosophy and Law of the Academy of Sciences, Kazakh SSR, have familiarized themselves with the practices of the Soviets of Kazakhstan.

During the Late Paleozoic or Early Mesozoic the Zayarskaya dolerites (diabases) were intruded into rocks of the Lower Cambrian Usol'ye series (salt strata separated by carbonate and sulfate-carbonate layers) in the Angara-Ilim watershed area of the Irkutsk amphitheater. Both field observations of the two dolerites intruded into salt strata and experimental data on the system dolerite-NaC1 indicate these dolerites were implaced at low water-vapor pressures. They appear little changed except for veinlets or inclusions of halite and calcite, and rocks of skarn mineralogy result where they have intruded nonsalt strata. Contacts between dolerites and salt are sharp, and between the NaCl and dolerite melts none of intermediate composition were found experimentally. In general, iron-bearing sublimates are evolved from the superposition of trap magma onto halogen rocks. No migration of volatile iron chlorides is evident in the Zayarskaya intrusives because the requisite high water-vapor pressures and outlet chann...

A modified thermomechanical method is used as a basis for developing new means of rapid determination of the numerical values of the parameters u0, γ and ur,0, γr in the Zhurkov lifetime equation and the Aleksandrov-Gurevich-Lazurkin relaxation time equation, which respectively characterize the strength and relaxation properties of polymers. For this purpose a special law of temperature variation is used in recording the thermomechanical curve under constant tensile stress. This makes it possible to avoid the mathematical difficulties associated with the quantitative description of that curve.

Introduction. The obstetric and gynecological clinic at the University of Warsaw, functioning as such, from 1869 to the present, has only for a relatively short period of time a report drawn up by the former resident of the clinic, Dr. I. I. Fedorov. This report partially fills this gap. The report includes the time from January 1, 1874 to March 15, 1885, that is, until the day of entry into the management of the Warsaw obstetric clinic by prof. N.V. Yastrebova. At the reporting time, the clinic was until 1884 under the direction of prof. Tyrkhovskaya, and from 1884 to March 15, 1885 prof. L. Neugebauer. The material for this report was collected only from the records found in the so-called control books of the Midwife Institute according to the generally accepted plan for such reports. Mournful sheets of time running the clinic prof. We had no opportunity to use Tyrkhovsky, because for reasons unknown to us, they were not in the archives of the clinic. Therefore, some sections of this report, as will be seen from the following, are far from complete, others were not developed at all due to incomplete data (for example, data on estates, employment, on the legality of birth and causes of death of children, etc.), or were developed only from a general point of view (for example, data on presentations, operations, etc.); so for example, in the section of this report on labor complications, no mention is made of complications of labor with a narrow pelvis, since in most cases it is mentioned in the records only by such a general phrase as "strictura pelvis", occasionally with a designation of the degree of contraction (in I, II , III gradu), in other cases marked or only conjug. externa, or, finally, in comparatively very few cases, conjug. vera; about dist. spin and crist. not mentioned at all; with all this, the dimensions are given for the most part in Polish inches (cale), rarely in centimeters.

The changes in the properties of certain polymeric materials subjected to the action of plane shocks of varying amplitude are discussed. Three loading techniques are employed — single, multiple, and high-frequency multiple loading — each accompanied by a different rise in the temperature of the polymeric material. The results show that the change in physicomechanical properties also varies with the loading technique.

Experiments on isotactic polypropylene films were used to study the relationship between parameters of the tensile stress/strain diagram and the size of supermolecular structure elements (spherulites). Certain qualitative and quantitative laws were established. Test results showed that the spherulite size affects almost all the mechanical properties studied (except the recrystallization stress), especially the parameters characterizing the deformation of polypropylene. Microscopic examination showed that the rupture of spherulitic structures in most cases takes place along the spherulite boundaries. Such ruptures can be attributed to the unavoidable presence of large defects between spherulites in the initial polymer films.

A graphoanalytical method of calculating the stress relaxation curves at constant strain is described. By its means the constants characterizing the mechanical properties of polymers can be easily and rapidly determined.