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The overwhelming majority of currently operating nuclear reactors are water-cooled. A further advancement of this trend is associated with the development of supercritical water-cooled nuclear reactors (SCWR). The work on developing SCWR is being conducted within the scope of the Generation IV International Forum. In Russia, one of such developments is related to the V-670 VVER SKDI reactor unit (RU), the concept of which was proposed by the NRC “Kurchatov Institute” in the 1990s. The VVER SKDI is a shell-type water-cooled reactor, which utilizes supercritical water and features an integrated primary circuit layout with natural coolant circulation. These features provide a high level of RU safety and make it possible to eliminate a number of safety systems (SS), which are present in the design of modern VVER reactor units. This paper offers a safety analysis of the V-670 VVER SKDI unit in comparison with the V-392M unit for a well-studied NPP-2006 project. A description of potential accidents and safety systems designed for the V-392M unit is provided. A detailed description of specific featured of the VVER SKDI reactor is presented, and their effect on reactor safety is analyzed. In addition, a review of potential issues in the core zones of the foreign single-circuit SCWRs is performed. Such reactors are characterized by tight fuel rod spacer grids and high operating temperatures of the fuel rod cladding, which could interfere with flooding of the active zone and result in rapid cladding temperature growth during LOCA. Such problem can be avoided in the VVER SKDI reactors, which have a moderate level of core temperatures and wider spacer grid. The paper summarizes the advantages of V-670 RU and discusses the challenges that must be resolved in order to advance the development of the VVER SKDI reactor design.

Inkjet ink based on silver nanoparticles with sizes of 11.1 ± 2.4 nm has been developed. Test images are printed on a laboratory inkjet printer, followed by sintering the printed patterns with a diode laser having a wavelength of 453 nm. The structure and electrical properties of the resulting films are studied depending on the parameters of laser sintering. It is found that under optimal conditions, an electrically conductive film with a low resistivity of 12.2 μΩ· cm can be formed.

Results of spectral-luminescent and electroluminescent studies of organic semiconductor zinc complexes in light-emitting diode devices are presented. A displacement of the electroluminescence band maximum toward longer wavelengths with structure complication is shown. Devices based on zinc metal organic complexes have low threshold voltage (from 2.5 V) and brightness above 100 cd/m2.

Spectral-luminescent and lasing characteristics of rhodamine 6G in porous aluminum oxide films anodized under various conditions are investigated. Lasing is obtained without external resonator in the longitudinal scheme under excitation by the second harmonic of Nd3+:YAG-laser radiation. The threshold pump power densities are in the range 3.5–15 MW/cm2 depending on the anodizing conditions. Wherein, the lasing line narrows down from 12 to 5 nm.

Spectral, luminescent, and lasing characteristics of chromene dyes and their julolidine analogs emitting in the red spectral range are investigated experimentally and theoretically. It is shown that the cause for a low lasing efficiency of oxochromene compared with iminochromene is a high intersystem crossing to the T 1 state and the presence of the induced T 1→T n absorption in the region of the luminescence band.

The consequences of postulated beyond design-basis accidents in the IR-8 reactor are now being analyzed. Since the development and construction of a three-dimensional model of IR-8 the ATHLET systems code has been used to perform computational thermohydraulic analysis of the consequences of an accident involving damage to a horizontal experimental channel. The maximum possible dewatering of fuel assemblies in the core (42 cm) with a leak appearing in a 100 mm in diameter channel due to a 2.5 mm gap opening along the entire perimeter, which could be due to the failure (detachment) of the bottom plate, is analyzed.

Results of spectral-luminescent and electroluminescent investigations of organic semiconductor polyfluorenebased copolymers in diode devices emitting dark blue, green, red, and white light are presented.

Conditions are described under which films of [(aminophenyl)azo]pyridine are formed by molecular layer epitaxy, and their optical absorption and x-ray photoelectron spectra are investigated. The nonlinear properties of such structures are described with the help of measurements of the intensity of second harmonic generation as a function of the angle of incidence.

In order to establish the scientific principles of a technology for the production and ladle treatment of new steels that can be quenched at forming, steels which were made in factory and laboratory heats and had different carbon contents were analyzed to explore the key factors and processes that determine both their total content of nonmetallic inclusions (NIs) and their content of certain types of NIs – particularly the types that are harmful. It was found that the most important factors in producing steel which is clean based on its content of all types of inclusions (which has an NI rating no higher than 1.5 in the government standard GOST 1778) are the slag regime and the ratio of the weights of the lime and aluminum added to the steel-pouring ladle during tapping. The optimum ranges of values for these parameters are determined. The existing requirements on the slag-regime parameters are observed to ensure a low content of harmful corrosion-active nonmetallic inclusions (CANIs) in the steel. However, it is essential to maintain a low (at or below the lower limit of 0.02% specified for the grade of steel) aluminum content for the duration of the ladle treatment. Aluminum content can be increased during the final stages, if necessary. A study was made of the effect of the MgO content of the covering slag on the possibility and rate of formation of CANIs based on alumomagnesian spinel. it was found that the steel’s content of such inclusions rises sharply when the concentration of MgO in the covering slag is greater than 14.1%. An MgO content of up to 8% guarantees that the steel will be clean based on its content of all types of inclusions. The results obtained for the metal of two trial heats confirmed the adequacy of the key parameters that were identified and the ranges of values for those parameters which were determined to be optimum for obtaining a low CANI content and high resistance to local corrosion.

Spectroscopic characteristics of complexes of Cu[I] ion with halogens synthesized by the TDDFT/CAM-B3LYP method are studied. It is shown that S0 → S1 and S0 → T1 electronic transitions are excitations with charge transfer. In this case, the electronic transitions proceed from the HOMO, HOMO-1 and HOMO-2 localized on halogen atoms to the LUMO localized on a ligand. The matrix elements of spin-orbit interaction are calculated using the single-electron operator (HSO). Based on these compounds, the organic light emitting diodes have been created. Their current–voltage and current-brightness characteristics are investigated.

The absorption spectra of the triplet excited state of coumarin sensitizers are investigated both theoretically and experimentally. The most intense triplet-triplet (TT) absorption bands are determined. The experimental spectra of the T-T absorption are compared with the theoretical T-T transitions. The phosphorescence spectra of five compounds are measured at a temperature of 77 K. The quantum phosphorescence yield is determined by the method of comparison with an etalon (8-methoxypsoralen). The phosphorescence lifetime is determined for the examined molecules at a temperature of 77 K. For 3,4-phenyl-4',5'-cyclohexylpsoralen, 4'-methyl-3,4-cycloheptylpsoralen, and 4'5'-dimethyl-3,4-cyclohexylpsoralen compounds, this time is equal to 1.1, 1.25, and 2.5 s, respectively. The main energy deactivation channel for all examined compounds is the phosphorescence. The positions of the lower excited triplet states, calculated by the quantum-chemical method of intermediate neglect of differential overlap with spectroscopic parameterization (INDO/S), are confirmed by the available experimental data.

A numerical modeling technique has been used to study the dynamics of generation of induced emission in a series of organic compounds: coumarin (7-amino-4-methylcoumarin and 6-bromo-3-(4-(4-bromophenyl) thiazole-2-yl)-coumarin) and rhodamine 6G. The effect of concentration on the lasing wavelength (rhodamine 6G) has been elucidated, along with the lasing capability of 7-amino-4-methylcoumarin at different pump pulse durations. The reasons for the absence of lasing in 6-bromo-3-(4-(4-bromophenyl)thiazole-2-yl)-coumarin have been investigated.

Lasing characteristics (spectrum, lifetime, and energy) of solid-state active media based on pyrromethene 567 (PM567) in polymethylmethacrylate (PMMA) and hybrid polymers (PMMA–POSS) are investigated. Patterns of changing the lasing characteristics depending on composites and excitation conditions are established. It is demonstrated that the solid-state active media with efficiency and lifetime that are not inferior to solutions can be synthesized on their basis.

A procedure of theoretical investigations into the dynamics of energy level populations of organic molecules upon high-power laser excitation is developed that allows information on stimulated emission of molecules, gain and lasing spectra, dynamics of lasing pulses, populations of the ground and excited states, and influence of the induced absorption on lasing of the organic molecules to be obtained. Laws of changing of the above-indicated processes are established for two pyran substitutes. Results of theoretical and experimental investigations are well correlated.

Results of experiments conducted on a large-scale integral PSB-VVER bench and directed toward investigation of the performance of new passive safety systems for nuclear plants with a water-cooled power reactor, an additional system for passive flooding of the active zone, and a system for the passive removal of heat from steam generators are presented.

The review is devoted to angiogenin, one of the factors that induce formation of blood vessels, which is unique in that it is a ribonuclease. Consideration is given to the tertiary structure of human angiogenin; the catalytic and cell receptor binding sites, their significance for angiogenic activity; the human angiogenin gene structure, chromosomal localization, and expression; the specificity of angiogenin as a ribonuclease and abolishment of protein synthesis; the nuclear localization of angiogenin in proliferating endothelial cells and its significance for angiogenic activity; angiogenin binding to cell surface actin as a plausible mechanism of inducing neovascularization (enhancement of plasminogen activation by actin, stimulation of the cell-associated proteolytic activity; promotion of the cultured cell invasiveness); modulation of mitogenic stimuli in endothelial, smooth muscle, and fibroblast cells by angiogenin. The importance of angiogenin as an adhesive molecule for endothelial and tumor cells is discussed too, as well as the modulation of tubular morphogenesis by bovine angiogenin, prevention of tumor growth in vivoby angiogenin antagonists, prospects of the use of angiogenin and angiogenin-encoding recombinant plasmids and vaccinia virus in therapeutic practice.

In this paper, we propose standards which can be used to simply and reliably monitor the content of technogenic radioactive substances in rivers and other bodies of water. We introduce the concept of “maximum safe concentration” and “reference monitored concentration” of radionuclides in water, and also the “maximum concentration of radionuclides in bottom sediments.” To determine the maximum safe concentration of radionuclides in water, we have used the basic public health principle established in NRB-96: to not exceed the limit of an effective dose of 1 mSv/y for external and internal radiation exposure for a critical population group, considering overall water use. To define the degree of radioactive contamination of the bottom of bodies of water, we propose using the maximum concentration of radionuclides in bottom sediments: a concentration less than that for which the bottom sediments may be classified in the category of “low activity solid radioactive wastes” according to OSP-72/87. We offer a calculation scheme and numerical values for the proposed standards for some radionuclides most frequently encountered in practice and examples of their use.

Powerful gas-discharge devices controlled by a small signal are of considerable interest in connection with problems of high-current electronics and high-voltage switching technology. In the present paper we study the semi-self-maintained discharge in the rarefied gas between coaxial cylindrical electrodes in an external azimuthal magnetic field. We demonstrate that under specific conditions the discharge will be maintained only in the presence of an external triggering current or where the discharge current is considerably greater than the triggering current.

The self-consistent equilibrium states of an electron beam in a longitudinal magnetic field B are investigated with the use of a model distribution function having quadratic dependence on the canonical angular momentum. The multiple character of the equilibrium is demonstrated for certain limited values of B (in particular, for B = 0).

isobaric. The current produces Joule heating, namely an additional bulk heat source, which extends to the entire current layer and which may play an important part in the energy balance. We consider the stationary state on the assumption that thermal conduction is the main mode of heat loss. The problem can be formulated as follows in a frame of reference coupled to the free flow: One has to determine the structures of the thermal and current boundary layers formed in rectilinear motion of distributed heat sources and the bifilar current in the gas. 1. Figure 1 shows the disposition of the axes of the cylindrical coordinate system and the sections of the thermal and current layers. The forward current I with density J0 = (0, 0, J0) is localized in a column of radius a and sets up the azimuthal magnetic field B 0 = (0, B0, 0). The reverse current with dens[tyj = (Jr, 0, -jz ) produces the opposite field B' = (0, -B', 0). The component Jr of the reverse current is localized in the main in a small region of the initial section. The total magnetic field B = (0, B, 0) can be written as