Perspectives of application of the molecular layer deposition technique for controlling operational properties of materials for shipbuilding

The results of investigations of surface modification of glass hollow microspheres are summarized. The regularities of the chemical molecular layering nanotechnology and its application for production of fillers and composite materials of low density with improved operational properties are discussed. Influence of chemical modification on thermal stability and combustibility of various polymer composites is investigated.     

Measurements of soil radon in South Russia for seismological application: Some results

Results of soil radon concentration measurements at the surface in Northern Caucasus (Krasnodar territory) in different geological features are shown. Measurements were made in mud volcanoes, faults, mineral deposits and landslips. The data were compared to seismicity. Before earthquakes, the changes in the concentration of radon appear as “humps” or “splashes” of various durations. Monthly, daily and hourly changes of the concentration of soil radon during the earthquakes are shown for each zone of researches. The simultaneous measurement of radon in the big area has shown the movement of the increased concentration of radon to the epicenter several days prior to the earthquake.     

Luminescence properties of β-(Ga1−xInx)2O3 solid solutions

In this work, luminescence properties of β-(Ga_1−xIn_x)₂O₃ solid solutions were investigated with the purpose of making the new thermoluminophors for ultraviolet (UV) dosimetry. The doping of aliovalent cation admixture (Mg, Mo) in the β-Ga₂O₃ ceramic sample brings about the appearance of high-temperature thermoluminescence glow peaks with a maximum at 395 and 435 K. The maximum of the thermoluminophor photosensitivity shifts when the composition of solid solution changes.     

Tritium measurement in the Western Caucasus

Measurement of tritium in water of rains, springs, wells, mud volcanoes and rivers, lakes of the Western Caucasus (Krasnodar region) has been carried out since 1997 for hydrogeology, engineering geology, ecology and seismology. Electrolytic cells with spiral electrodes and the big multiwire proportional chamber were used for low tritium concentration measurements on expeditions. With the new design of the cell the enrichment factor of 64.0 ± 1.5 % was obtained during the electrolytic process. Correlation of tritium concentration is observed in mud volcanoes and spring water with regional seismicity. The long-term tritium data are shown in natural waters in South Russia.     

Structural Changes in the Surface Friction Layer of a Polymeric Endoprosthesis Cup

A concept of creation of a polymeric insert for hip joint endoprostheses with the physiological and biomechanical properties typical of natural cartilage is proposed. The spherical friction surface of the insert is coated with a microporous layer imitating cartilage. This layer carries an electret charge, which improves the lubrication of the endoprosthesis with synovia and serves as a carrier of drugs, thus ensuring their prolonged discharge into the operation wound. Tribotechnical characteristics of an endoprosthesis with such an insert are investigated. It is shown that a drop in the friction coefficient of such a pair is accompanied by a change in the microrelief of the friction surface and in the degree of crystallinity of the material of the porous layer.     

Contact angles as indicators of the polymer surface structure

The capacities of the wetting method for the characterization of the surface structure of polymers and surfactant adsorption layers on polymer surfaces and also the determination of the energy characteristics of polymer surfaces at different interfaces, which are used to optimize the choice of polymers in the solution of actual practical problems, are demonstrated.     

Studies of cosmic gamma-ray bursts and soft gamma repeaters in the Russian-American Konus-Wind experiment

The studies of the cosmic gamma-ray bursts and soft gamma repeaters that have been performed in the Russian-American Konus-Wind experiment during the last several years have been summarized. The experiment has been continuously performed using the Konus Russian scientific instrument on the Wind American spacecraft since 1994 under the optimal interplanetary space conditions in the absence of noise caused by the Earth’s radiation belts and the shadowing of detectors. Two high-sensitivity detectors have constantly observed the entire celestial sphere and recorded detailed time and spectral characteristics of bursts in a wide range of energies (20 keV–15 MeV). The Konus-Wind data have been widely used in the present-day multiwave studies of gamma-ray bursts.     

Measurement of the <Superscript>222</Superscript>Rn background in the DEVIS experiment

In the DEVIS tracking experiment that is being performed at the Institute of Theoretical and Experimental Physics (ITEP, Moscow, Russia) and which is devoted to searches for ¹³⁶Xe double-beta decay, the ²²²Rn concentration is measured in xenon samples with different content of the isotope ¹³⁶Xe. The number of probable double-electron events from ²¹⁴Bi decay mimicking the double-beta decay of ¹³⁶Xe is estimated.     

The heat capacity of the ethylene glycol-tetrahydrofuran system over the range of tetrahydrofuran concentrations 0–20 mol %

The heat capacity of the ethylene glycol (EG)-tetrahydrofuran (THF) system was measured over the range of THF concentrations 0–20 mol % and the temperature range 0–50°C using a DSC204FI differential scanning calorimeter. It was found that the heat capacity passed through a maximum at a THF concentration of 5 mol %; the maximum became more pronounced as the temperature increased. It was suggested that the maximum was caused by microphase separation at THF concentrations of 5–10 mol %. We were unable to observe phase separation with the lower critical point visually over this concentration range up to 95°C. Original Russian Text ? M.N. Rodnikova, D.B. Kayumova, L.A. Tsvetkova, I.A. Solonina, 2009, published in Zhurnal Fizicheskoi Khimii, 2009, Vol. 83, No. 6, pp. 1196–1198.