The function of the reproductive system in x-ray-irradiated male rats after the transplantation of a culture of testicular cells from newborn piglets

The effect exerted by transplantation of the 5 day culture of testicles from newly born piglets on the hypogonadal state of mature X-ray irradiated (3 Gy) rats was studied. It has been found that a month after transplantation (two months after irradiation) the hypogonadal state disappeared for a while, which is confirmed by normalization of the weight of seminal vesicles, content of testosterone and biologically active lutropine, restoration of the reproductive function of rats. No significant changes in steroidogenesis activity have been found, which proves a substituent character of transplantation. The effect disappears three months later but certain restoration of the content of nucleic acids in the testicles is observed.     

The comparative characteristics of the Salmonella serotypes rarely encountered in the Maritime Territory

The results of the comparative study of the phenotypical properties and the plasmid profile of 63 strains of salmonellae, belonging to 44 serotypes of groups B, C1, C2, C3, D, E1, E4, F. The study revealed that strains of different serotypes had their individual plasmid profile. Strains of the same serotype of salmonellae isolated from similar sources had an identical plasmid profile, while strains isolated from different sources differed in their plasmid profiles, though they might have a similar phenotype. Plasmid analysis was shown to be an effective method for the intraspecific typing of rarely isolated Salmonella serotypes and suitable for use as the basis of the microbiological monitoring of salmonellae.     

Phase Transformations in Martensitic Steels Tested for High-Temperature Fatigue

The method of layer-by-layer physicochemical analysis is used to study phase transformations in chromium-nickel steels of martensitic class after high-cycle fatigue tests and after thermal exposure at similar temperature and time conditions. The Laves phase is shown to be distributed nonuniformly over the cross section of specimens tested for fatigue resistance. The results of the tests are used to correct phase compositions.     

High-current-density subnanosecond electron beams formed in a gas-filled diode at low pressures

The formation of electron beams in a gas diode filled with various gases at low and medium pressures under the action of nanosecond voltage pulses has been studied. It is shown that subnanosecond pulses of the beam current in helium, hydrogen, neon, nitrogen, argon, methane, sulfur hexafluoride, krypton, and xenon can be obtained both at atmospheric pressure and at a pressure of several units or dozens of Torr. In particular, a beam current density above 2 kA/cm² behind the foil at a pulse duration (FWHM) of 250 ps has been obtained in helium-filled diode. On the passage from the regime of ultrashort avalanche electron beam formation to the vacuum diode regime, the beam current pulse amplitude decreases, while both the beam pulse duration (FWHM) and the pulse front width increase.     

Method for removing silicide coatings in a medium of low-melting metals

We propose a method for removing silicide coatings from the surfaces of workpieces made of refractory metals. The entire volume of the silicide layer is borated in a melt based on low-melting metals. The boride layer formed as a result is characterized by a large number of defects, low mechanical strength, and high etching susceptibility. Therefore, it can easily be removed by any existing method.Karpenko Physicomechanical Institute, Ukrainian Academy of Sciences, L'viv. Translated from Fiziko-Khimicheskaya Mekhanika Materialov, Vol. 30, No. 3, pp. 121–124, May – June, 1994.     

Change in the structure of alloy VT22 with the combined action of ultrasonic radiation and thermal cycling treatment

A study is made of the structure of alloy VT22 with thermal cycling treatment (TCT) and also with TCT and prior ultrasonic irradiation (USI) by the methods of metallography, electron microscopy, and hardness measurements. It is shown that TCT for annealed specimens promotes recrystallization, fragmentation, and spheroidization of and phases.It is established that TCT of specimens quenched to phase previously treated with ultrasonic radiation leads to formation of -phase platelets of considerably smaller dimensions and more strongly fragmented compared with -phase platelets after TCT for unirradiated specimens.Translated from Problemy Prochnosti, No. 10, pp. 47–49, October, 1990.     

Corrosion-Resistant Steels for Force-Measuring Elastic Members

The mechanical and corrosion properties of copper-bearing maraging steels used for fabricating force-measuring elastic members of electronic strain-measuring scales are studied. The effects of aging temperature, process heating, and presence of oxide film on the hardness, impact toughness, and parameters of the anode process in potentiodynamic tests are investigated. After an analysis of the obtained results, a steel composition is recommended for the production of force-measuring members, and a regime for its heat treatment is chosen.     

A high-power xenon dimer excilamp

A high-power sealed-off excilamp operating on xenon dimers excited by a barrier discharge and emitting in the vacuum ultraviolet spectral range (λ ～ 172 nm) has been designed, constructed, and tested. The lamp comprises six quartz tubes (emitters) and has a total radiating surface area of 20 × 20 = 400 cm². The average output power density radiated from the surface of each emitter exceeds 120 mW/cm². The total output power of the excilamp immediately upon discharge ignition exceeds 50 W.