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We present here results from model experiments with poikilotherm hydrobionts belonging to different taxonomic groups: crayfish (Pontatacus leptodactylus), fish, i.e., carp (Cyprinus carpio), and amphibians, i.e., axolotl (Ambystoma mexicanum). Fatty dystrophy of the hepatopancreas in crayfish and pathology of the pancreas in carp were modeled by administration of alloxan at doses of 50 and 200 mg/kg, respectively. Crayfish received alloxan into the ventral sinus and fish were treated i.p. Liver pathology in fish was modeled by administration of seven doses of paracetamol 15 g/kg over 14 days. Parenteral administration (into the central sinus of crayfish, i.v. in fish, and i.p. in axolotls) of stem and progenitor cells from mammalian donors (mice) at a dose of 10·106 bone marrow cells (BMC) was found to have effects. Fish and crayfish with pathology displayed intensive tissue regeneration and restoration of damaged parenchymatous organs. Administration of stem cells accelerated the process of regeneration of amputated limbs in axolotls. These results extend the potential of medical-biological studies of in vivo models.

Field tests of oil line tubes from commonly used steels are performed. It is shown that the tubes produced from low-alloy Cr, Mo, V steels have higher resistance to corrosion-mechanical fracture.

The isochoric thermal conductivity of gama-O2 has been studied on samples of varying density in the temperature interval from 44 K to the onset of melting. The thermal conductivity of nearly free sample decreases at rising temperature along the isochores. It is shown that the absolute value of thermal conductivity in the gama-phase of O2 is close to its lower limit and most of the heat is transported by "diffusive" modes. The growth of thermal conductivity in gama-O2 is attributed to the decay of the phonon scattering at the rotational excitations of the molecules and at the short-range magnetic order fluctuations at rising temperature., Comment: Postscript 9 pages, 2 figures, 1 table. To be published in 2005

The experimental work performed on a BOR-60 reactor over a period of 30 years of reactor operation is briefly reviewed. The results of investigations of the neutron-physical, thermohydraulic, and dynamical characteristics and the safety parameters of the reactor are presented. The investigations performed and the analysis of transient and emergency regimes made it possible to improve the standard shutdown and cooldown systems in order to soften the temperature conditions on the reactor components. The result of a series of experiments on the safety of fast sodium reactors, among which the introduction of gas into the core, sodium boiling, blocking of the flow in the experimental fuel assembly with destruction of fuel elements, interloop leakage in the steam generators, and so on, are discussed. A complex of diagnostics systems has been developed and tested on the basis of the safety investigations. Analysis of the radiation parameters and characteristics of the reactor made it possible to develop methods and means for monitoring and improving the radiation conditions and the safety of the reactor. Experimental irradiation of various initial materials, using threshold and other reactions, enabled the serial production of radionuclides for medical purposes.

Systematic investigations of the kinetics of redox reactions with the participation of U(IV), Pu(III, IV), HNO/sub 2/ in aqueous nitric-acid solutions in systems with TBP have been undertaken, permitting not only the quantitative description of the reaction rates but also a new approach to the construction of a mathematical model of the reductive reextraction of Pu(IV) by tetravalent uranium in multistage extraction apparatus. In the model proposed, the extraction stage is arbitrarily divided into three reaction volumes: a mixing chamber, and the volumes of aqueous and organic phase in the settling chamber, each of which is modeled as an ideal-mixing reactor. It is assumed that mass transfer between the phases as a result of extraction only occurs in the mixing chamber; simultaneously, the corresponding redox reactions occur there. It is also supposed that in the settling chamber the concentration of the components changes only on account of chemical reaction.

1. The research performed has shown that, in the course of lengthy thermoradiation aging, the electric strength of the casing and turn insulation of the electromagnetic pump windings undergoes significant changes. Further, if the electric strength decreases in the initial aging period, then stabilization and even a certain increase in the breakdown voltage, will subsequently occur. 2. Processing the results of electric strength measurements makes it possible to use the data for individual samples to obtain analytic expressions for the breakdown voltage distribution function for the electromagnetic pump windings, to find calculated values of the parameters, and to estimate the possible service life of the coil insulation. 3. The values obtained for the breakdown voltage of the casing and turn insulation allow us to conclude that for a temperature not exceeding 410°C and a neutron fluence of up to 8.7·1019 m−2, in the absence of vibrational, current, and other loads, the electric insulation materials used in the electromagnetic pump windings can maintain acceptable electric strength for approximately 24,000 h.

1. As a result of an investigation into the compressibility of nickel powders in strip rolling, it was established that the best compressibility over the range Psp max = 12.5–67 kN/cm2 (1.25–6.7 tons/cm2) is exhibited by atomized powder and the poorest compressibility by carbonyl-nickel powder. The relationships established are supported by results of x-ray diffraction studies. 2. Using x-ray diffraction techniques, it was determined that the broadening of the interference lines of carbonyl-nickel specimens is linked with the size of c.s.r., the magnitude of microdistortions, and the presence of s.f. The role of each factor depends on the degree of compression of the powder: For the starting powder, the extent of broadening due to s.f. amounts to about 30% of the physical breadth of the (111) line. After rolling at Psp. max = 67 kN/cm2 (6.7 tons/cm2), the line-breadth fraction due to s.f. decreases by half. 3. The presence of s.f. in the starting carbonyl nickel and in strips rolled from it confirms that the crystal-growth and plastic-deformation processes are governed by the dislocation mechanism. 4. The relationship MΔa/a- 0.4d, obtained for cold-deformed bulk nickel, has been found to apply also to the rolling of carbonyl-nickel powder over the range Psp. max = 46–67 kN/cm2(4.6–6.7 tons/cm2).

1. The accuracy of the readings of a point dynamometer depends upon the correct setting of the projection of the measuring pin. 2. The optimal projection of the measuring pin can be determined by formulas (3) and (4). 3. The accuracy of the measurement is higher, the smaller the diameter of the measuring pin for a given elastic element or smaller the deformation of the elastic element at a given diameter of the measuring pin, but not to the detriment of the sensitivity of the dynamometer.