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Three charge density waves (CDWs), two of which are formed above room temperature, are observed in the NbS3 monoclinic phase (NbS3-II). The charge density and mobility in the high-field limit have been determined for each of three CDWs in this work using the synchronization effect of CDWs in high-frequency fields. It has been found that the mobility of each CDW in this limit is approximately equal to the normal-state mobility of quasiparticles condensed in it. Furthermore, correlation has been observed between the temperature dependences of mobilities of CDWs and quasiparticles. The results of this work refresh problems of a mechanism of the limit conductivity of CDWs and of the distribution of CDWs between atomic chains in the unit cell.

A new polytype of the quasi-one-dimensional conductor NbS3 with high-temperature charge density waves has been synthesized. The transmission electron microscopy study at room temperature has revealed only one of the two superstructures existing in the previously studied monoclinic phase with the period along chains close to b/0.352. In addition, a new incommensurate distortion of the lattice with the period close to 2b has been observed. The transport properties of the samples under study are in agreement with the study of the superstructure. The main lattice constants are somewhat different from the respective parameters in the previously studied monoclinic phase. The new phase can assumingly be intermediate between the two main known phases of NbS3, monoclinic and triclinic. Its properties can be explained within a model where a unit cell of the monoclinic phase can be considered as the superposition of unit cells of the triclinic phase.

Experience gained from the operation of nuclear power plants shows that emergencies or incorrect actions of the personnel may give rise to water hammer phenomena, which exert additional impacts on the pipelines and equipment. Condensation-induced water hammer (CIWH) is one of the most destructive kinds of water hammer. Experimental studies of CIWH were carried out in a number of scientific organizations around the world. The main features of the experimental facilities used in the world are considered. For studying the CIWH phenomena occurring in a horizontal channel, a special experimental test facility was set up in 2018 at the Elektrogorsk Research and Engineering Center for Nuclear Power Plants’ Safety (EREC). The facility’s test section and the parameters of experimental regimes are described. Fifty-two experiments were carried out on the facility under different initial and boundary conditions for three values of the water flowrate supplied to the facility (1, 3, and 5 t/h), two values of water temperature (30 and 60°С), and two values of vapor pressure in the test section (0.6 and 1.0 MPa). In all experiments, CIWH phenomena were recorded. As an example, one experimental regime was considered in detail, and the CIWH occurrence mechanism is described proceeding from the readings of pressure and level gages and temperature sensors. The described experimental regime was modeled using the RELAP5 and WAHA thermal-hydraulic codes. The effect that the size of nodalization diagram cells and the integration time step have on the computation results is analyzed. The significant amount of experimental points obtained from the study can be used for setting up a database for validating computer codes.

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.

Used electron-beam additive manufacture with two wire filaments simultaneously produced composite 321SS/CuA19Mn2 with 50:50 components ratio. Investigated of microstructure and mechanical properties of composite 321SS/CuA19Mn2 and compared with properties of stainless steel with aluminum bronze produced by electron beam additive manufacture. It was found that the formation of the composite 321SS/CuA19Mn2 leads suppresses of the residual β’-phase: diffusion of elements initiates phase transition from γ-Fe to α-Fe and leads to formed nanoparticles of κiv-phase in solid solution of α-Cu. Mechanical tensile tests and microhardness were showed composite 321SS/CuA19Mn2 have highest microhardness (∼3280 GPa) and highest tensile strength (830 MPa) as compared with steel and bronze produced by additive manufacture.

The OECD/NEA Benchmark on NPP Kalinin Unit 3 “Switching-off of one of the four operating main circulation pumps at nominal power” based on measurements is at its end phase. A new benchmark is starting based on measurements from the NPP Rostov Unit 2 “Reactivity compensation with diluted boron by stepwise insertion of control rod cluster into the VVER-1000 core”. The Rostov-2 core is loaded with assemblies of a new modern type “TVS-2M” which differs in construction in comparison with the “TVSA”-type implemented in the Kalinin-3 core. The goal of the performed study is to determine the thermohydraulic differences, during steady-state operation, between the two cores based on loads with different assembly types. Results of steady-state simulations are compared for Kalinin-3 and Rostov-2 cores, taken from the respective Benchmarks specifications. To ensure that the observed differences are coming only from the fuel assembly construction, the same axial power density is used for all cases. Calculations are done with an under-development version of the GRS system code ATHLET, which has sub-channel modeling capabilities. Thus, in addition to the typical assembly-wise models, calculations with seven assemblies modeled at the sub-channel (pin-by-pin) level were also performed and analyzed. This work will help the Benchmarks' Rostov-2 participants to set up more accurate core thermohydraulic models.

Problem formulating. The features of linear and nonlinear conductivity, magnetic conductivity, thermopower, and the Hall effect observed on TiS3 whiskers indicate phase transitions to a state of CDW in this compound, but there is no direct evidence yet. The study of photoconductivity would allow us to learn more about the nature of these phase transitions. Goal. Study of the effect of radiation in the range from near-IR to near-UV on the conductivity of single-crystal TiS3 whiskers at 4.2

The voltage dependences of conductivity, $\ensuremath{\sigma}(V)$, of the monoclinic phase of ${\mathrm{NbS}}_{3}$ are reported. The extremely high coherence of the room-temperature charge density wave (CDW) allows its synchronization by a rf field up to ${T}_{\mathrm{P}1}\ensuremath{\approx}365\phantom{\rule{0.16em}{0ex}}\mathrm{K}$, the temperature of the Peierls transition, and above it by about 10 K. The ratio of nonlinear current, ${I}_{\mathrm{nl}}=I\ensuremath{-}V\ensuremath{\sigma}(0)$, to the fundamental frequency of the CDW sliding, ${f}_{\mathrm{f}}$, falls as T increases across ${T}_{\mathrm{P}1}$. This result is considered in terms of spontaneous phase slippage near ${T}_{\mathrm{P}1}$, which could give both single-particle and collective contributions to linear conductivity. The two contributions are considered, and the former is found to dominate. The temperature-frequency dependence of ${I}_{\mathrm{nl}}/{f}_{f}$ is consistent with the model of thermally activated phase slippage.

Монография посвящена истории хозяйственного освоения районов Европейской Арктики — Мурманского берега и архипелага Новая Земля — монастырями и крестьянами Поморья в XVI–XVIII вв. В работе на базе широкого круга документальных источников исследованы факторы, обусловившие процесс промысловой колонизации этих территорий: рассмотрена взаимосвязь хозяйственного освоения Мурманского берега и Новой Земли крестьянами и монастырями Поморья; охарактеризован территориальный, социальный и возрастной состав его участников; выявлена роль в нем крестьянской кооперации и такой социальной организации, как артель промышленников; прослежены изменения в состоянии промыслов на побережье Баренцева моря в XVIII в. под влиянием новой государственной политики, обусловленной модернизационными процессами. В исследовании также рассматриваются аспекты повседневной жизни промышленников мурманского и новоземельского промыслов. Книга рассчитана на специалистов по истории и источниковедению Русского Севера, а также на широкий круг читателей.

The presence of specific components in the environment can change the state of cenoses. The effect of ionizing radiation on plant communities, animals and humans have been well studied, while the effect on soil microflora has not been insufficiently studied. In this paper investigated the effect of radionuclide contamination on microflora of soil samples from the territory of PTLRW "Red Forest 1" (trench), "Red Forest 2" (outside the trench), " Cooling Pond " and " Zalissia ". Phospholipid fatty acid (PLFA) content was obtained by PLFA analysis. The highest level of total PLFA was observed in the territory of "Zalissia" which was 17.40 ± 10.59 μg / h. From the territory of PTLRW "Red Forest 1" (trench) and "Red Forest 2" (outside the trench) the level of total PLFA was 16.29 ± 3.43 μg / g and 16.40 ± 2.90 μg / h, respectively. The PLFA content of the "Cooling Pond" was significantly different from the "Red Forest" and " Zalissia ". The taxonomic groups assessment of the samples, a fungus, gram-positive and gram-negative bacteria content increased in PTLRW "Red Forest" relative to the point "Zalissia ".

The sliding of the room-temperature charge density wave (CDW) in the monoclinic phase of $\mathrm{Nb}{\mathrm{S}}_{3}$ under rf power is studied. The threshold field, ${E}_{\mathrm{t}}$, and Shapiro steps' width, \ensuremath{\delta}E, show aperiodic Bessel-type oscillations as a function of rf voltage. Here we demonstrate experimentally that, if presented as a function of CDW path length in each half period of the rf voltage, ${E}_{\mathrm{t}}$ and \ensuremath{\delta}E show periodic oscillations, the period being equal to the CDW wavelength. The result is found to be universal for different compounds and gives clear understanding of the synchronization effects in terms of forced oscillations of a particle in a periodic potential.

The layered quasi one-dimensional compound TiS3 is remarkable for its optical properties, especially, photoconductivity. Up to now, photoconductivity in TiS3 was studied only at room temperature. Here, we report photoconductivity, δσ, of the TiS3 whiskers in the temperature range of 5–300 K under irradiation in the near-infrared region. With a temperature decrease from room temperature down to T ∼ 100 K, δσ grows moderately, dominated by the variation of the mobility of the electrons. The estimates based on the values of δσ give the recombination time ∼3–25 μs at 300 K. The results show that above ∼100 K, TiS3 behaves as a semiconductor, where electron–hole pairs are excited across the gap, while the recombination goes through transitions of the excited electrons to a donor level with a long lifetime. Below 60 K, a drop of δσ is likely to reveal a phase transition of electrons into a collective state. Another feature in δσ( T) is seen around 17 K, resembling the temperature variation of the conductivity. This feature indicates a drop in the mobility of the electrons. While the behavior of δσ( T) is consistent with the transition of electrons into a collective state, it is strikingly different from δσ( T) of the known quasi one-dimensional conductors with charge-density waves.

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.

Experiments at the KGU test facility, devoted to condensation induced water hammers (CIWH) were analysed with the WAHA code. Test section of the KGU test facility is slightly inclined horizontal pipe of 3 m length and of 64 mm inner diameter. Subcooled water was supplied to the pipe inlet, pipe outlet was connected to separator vessel. Upper part of separator vessel was connected to steam source. Experiments were performed for different system pressure, different water subcooling and different mass flow rate of water supply. The performed experimental study of CIWH showed that in the investigated range of parameters, the development of CIWH occurs in different ways. At the stage of water propagation along the filled with steam horizontal pipe, water hammer was not observed. At the stage of free drainage of water from the outlet end of the pipe, water hammer was realized only when the water was sufficiently subcooled. At the stage of the water level rise in the horizontal pipe, water hammer occurred in all tests. At the last stage of filling the upper part in the separation vessel, there were small water hammers due to the collapses of the remaining steam bubbles. Numerical modelling of these experiments with the WAHA code revealed the shortcomings of the interphase heat transfer model developed for this code, which have a noticeable effect on the numerical solution.

Processing of experimental data on the pressure difference across a submerged perforated sheet (SPS) revealed that, at sufficiently high void fractions under SPS, the pressure difference across it became less than the pressure difference for the pure steam stream with the same flowrate. To find the cause of this, the effect of a liquid film, which can be formed on the SPS upstream surface as a result of water droplets’ impact and can smooth over sharp edges of holes in SDS, was examined. This can decrease the pressure drop across the sharp edges of holes. This assumption was checked through numerical solution to several model problems in the axisymmetric formulation for a steam flow in a round pipe with an orifice. The flow of steam and water was modeled using the viscous incompressible liquid approximation, while the turbulence was described by the k–e model. The evolution of the interfacial area was modeled using the VOF model. The following model problems of steam flow through an orifice were studied: a single-phase flow, a flow through the orifice with a liquid film on its upstream surface, a flow through a chamfered hole, and a flow through the orifice with a liquid film on its upstream surface without liquid supply to the film. The predictions demonstrate that even the approximate account of the liquid film effect on the steam flow yields a considerable decrease in the pressure drop across the hole (from 8 to 24%) due to smoothing its sharp outlet edges over. This makes it possible to make a conclusion that the cause of a decrease in the pressure drop across SPS observed in the experiments at high void fractions is the formation of a liquid film, which smooths the sharp edges of the hole.

In the present work, the structure and properties of products from heat-resistant nickel-based superalloy ZhS6U formed by wire-feed electron beam additive technology were investigated. Products were obtained under different parameters of electron beam additive process (accelerating voltage, beam current and movement speed of working table were varied). It was shown that a high speed of displacement leads to the formation of defects in the form of cracks and delamination of the obtained product from the substrate, which also leads to the appearance of cracks. It has been established that the greatest energy input leads to evaporation of aluminum (the main hardening γ’ phase). The phase composition of the additive product did not differ from the original material.

Goal of the study : to define the effect of various doses of laser radiation with 662 nm wave on the growth of M. tuberculosis in vitro. Materials and methods . Samples of mycobacterial suspension of M. tuberculosis H37Rv were processed by monopositional light radiation (λ = 662 nm) in six dosing regimens varying in power and duration of the exposure to the light. All samples of mycobacterial suspension of M. tuberculosis were inoculated on the solid nutritional media of Lowenstein-Jensen in triplets for each dose of the exposure to light. Cultures were incubated under 37°С for 90 days with weekly inspection of samples. Results . Continuous irradiation by diffused laser with 662 nm wave provides the most expressed bacteriostatic and bactericidal effects against M. tuberculosis H37Rv under the density of the energy dose of 234.5 and 703.5 of J/sq.cm. Such a dose was obtained through 5 and 15-minute exposure respectively.

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.

In the work, the method of wire-based electron-beam additive technology was used for the production of Cu-Ni and Fe-Cu-Ni system polymetallic samples. Wires of copper C11000 and nickel alloy Cr15Ni60 were used as wire filaments for printing. The samples with sharp interface between copper and nickel alloy and with smooth interface caused by gradual change of the copper and nickel wire feeding rate were produced. Defects in structure and regularities of the sample structure formation during printing are described.

In the present paper, products in the form of vertical walls from superalloy ZhS6U were obtained by the wire-feed electron beam additive technology. Influence of additive process parameters on formation of structural elements and direction of their growth was shown. In addition, the features of temperature gradient formation, which is the main parameter of directional solidification, were described. It was established while determining the parameters of additive growth it is necessary to consider the following: the regime for obtaining defect-free products leads to the deflection of the growth direction of structures and the enlargement of structural elements. Achieved values of temperature gradients correspond to modern methods of directional solidification realization.

In the present study, wall-shape product from nickel-based superalloy ZhS6U were obtained by the wire-feed electron beam additive manufacturing (EBAM). Changes in chemical composition of the products obtained depending on the energy input per unit length were investigated. Products had the shape of single layer or multilayer walls formed on the substrate from austenitic steel SS 304 without cooling. The content of chemical elements was measured by X-ray fluorescence spectrometer. As a result of the study the appropriate parameters of the process were revealed.

The temperature and voltage dependences of conductivity of the monoclinic phase of NbS 3 are reported. The extremely high coherence of the room-temperature charge-density wave (CDW) allows its synchronization (observation of Shapiro steps) under RF electric field up to T P1 =365 K, the temperature of the CDW transition, and even above it. The following regularity is established: the higher is the RF frequency, the higher is the utmost temperature of Shapiro steps observation. Thus, RF field can synchronize CDW fluctuations. The possible contributions of CDW fluctuations to linear and non-linear conductivity are discussed. The result present the NbS 3 whiskers as high-temperature nano-sized RF detectors.

We report I–V curves of quasi one-dimensional charge-density wave (CDW) conductors under simultaneous impacts of rf voltage at two frequencies, F and f, with F ≫ f. We find that each Shapiro step (ShS) induced by F-irradiation behaves as a “host” surrounded with “satellites” induced by f-irradiation, e.g., by ShSs at the CDW currents corresponding to F ± f. The subharmonic “hosts” are surrounded with subharmonic “satellites,” e.g., by ShSs at the CDW currents corresponding to F/2 ± f/2. The hosts and satellites show oscillations of their widths as a function of rf amplitude. We demonstrate that each satellite can be treated as a conventional ShS, if its host ShS is taken as a reference point at which the CDW is resting. Thus, with the help of rf irradiation one can emulate CDW samples with tunable threshold voltages and extremely coherent sliding modes.

The Shapiro steps (ShSs) developing in sliding charge-density wave (CDW) under rf irradiation are considered in terms of the CDW travel in the periodic (washboard) potential. We demonstrate that treating the CDW as an inertialess object whose velocity is defined by the instantaneous voltage one can predict the positions of the ShSs in dc voltages for the given amplitude of rf voltage. Moreover, the approximation allows indicating the rf voltages at which the ShSs' magnitudes show maxima and minima. The only information necessary in advance is the I–V characteristic without rf irradiation and the cross-sectional area of the sample. Thus, one can recover the course of an I–V curve in average and the positions of ShSs on it, though not their forms.