[Disturbances of thyroid function after coronary angiography].

Frequency of thyroid gland functional disturbances after introduction of iodine-containing radiographic contrast agents during coronary angiography was studied in 146 patients, residents of the zone of borderline iodine deficit. Frequency of thyroid pathology was high at baseline (39%). Functional state of the thyroid gland was assessed before and 1, 3, 6, 12 months after investigation. During first month after coronary angiography there were several new cases of thyrotoxicosis and hypothyroidism, as well as deterioration of preexisting functional disturbances of the thyroid. Patients with baseline pathology and functional disturbances of thyroid gland before conduction of coronary angiography should be included into risk group of development of iodine induced states.

Hysteresis in the de Haas-van Alphen effect.

A hysteresis loop is observed for the first time in the de Haas-van Alphen (dHvA) effect of beryllium at low temperatures and quantizing magnetic field applied parallel to the hexagonal axis of the single crystal. The irreversible behavior of the magnetization occurs at the paramagnetic part of the dHvA period in conditions of Condon domain formation arising by strong enough dHvA amplitude. The resulting extremely nonlinear response to a very small modulation field offers the possibility to find in a simple way the Condon domain phase diagram. From a harmonic analysis, the shape and size of the hysteresis loop is constructed.

Direct observation of condon domains in silver by Hall probes.

Using a set of micro Hall probes for the detection of the local induction, the inhomogeneous Condon domain structure has been directly observed at the surface of a pure silver single crystal under strong Landau quantization in magnetic fields up to 10 T. The inhomogeneous induction occurs in the theoretically predicted part of the Condon domain phase diagram. Information about size, shape, and orientation of the domains is obtained by analyzing Hall probes placed along and across the long sample axis and by tilting the sample. On a beryllium surface the induction inhomogeneity is almost absent although the expected induction splitting here is at least 10 times higher than in silver.

Self-consistent model of a positive column in a glow discharge under free-flight and collisional regimes of charged-particle motion.

We consider the nonlocal theory of a positive column in a glow discharge in two cases, where the mean free path of charged particles is either greater than the discharge tube radius (the free-flight regime) or much less than the radius (the collisional regime). The great bulk of electrons, which determines the density and the discharge current in the axial direction, appears to be trapped by the radial field of a positive column. The electron flux to the wall, which compensates for the ionization in a volume, is determined by fast electrons with energies of the order of wall potential, which are able to leave in a loss cone. The electron kinetic equation, which is solved by averaging it over the radial transits for the two regimes considered, permits us to obtain the electron density and the ionization rate. Thus, we develop the theory of a positive column for the non-Boltzmann electron distribution in the radial field. Under the free-flight regime, this theory is developed by analogy with the Langmuir-Tonks one. Under the collisional regime, the spatial distribution of the potential is obtained from the ion motion equation with the ambipolar diffusion coefficient, which depends on the radial coordinate. The concrete calculations are carried out for the xenon discharge under the free-flight and collisional regimes. The theoretical calculations are compared with the results of experiments on the measurements of the electric field and the densities of metastable and resonance xenon atoms.

[The working conditions during the prototype commercial operation of continuous-output equipment in KATEK coal stripping and sanitary improvement measures]. / Usloviia truda pri opytno-promyshlennoi ékspluatatsii kompleksa nepreryvnogo deistviia na ugol'nmom razreze KATEK i ozdorovitel'nye meropriiatiia.

Work conditions were analysed in workers engaged into realization of the new coal extracting line technology producing 5250 m3 of coal per hr in KATEK open-cast mine. Hygienic standards appeared to be followed mainly on the constant working places and in the mining machine cabs, but noise dust parameters were not evaluated in the transloaders, microclimate parameters of excavator and transloaders were not assessed during the cold season. High concentration of dust appear in the air due to mining machines cleaning with the pumped air. Workers engaged into the coal transportation and its intermediate storage appeared to work in more hazardous conditions. Sanitary measures are suggested.