Search

The DANSS detector (Alekseev et al. in JINST 11:P11011, 2016) is located directly below a commercial reactor core at the Kalinin Nuclear Power Plant. Such a position provides an overburden about 50 m.w.e. in vertical direction. In terms of the cosmic rays it occupies an intermediate position between surface and underground detectors. The sensitive volume of the detector is a cubic meter of plastic scintillator with fine segmentation and combined PMT and SiPM readout, surrounded by multilayer passive and active shielding. The detector can reconstruct muon tracks passing through its sensitive volume. The main physics goal of the DANSS experiment implies the antineutrino spectra measurements at various distances from the source. This is achieved by means of a lifting platform so that the data is taken in three positions – 10.9, 11.9 and 12.9 meters from the reactor core. The muon data were collected for nearly four calendar years. The overburden parameters $$\langle E_{thr}\cos \theta \rangle $$ ⟨ E thr cos θ ⟩ and $$\langle E_{thr} \rangle $$ ⟨ E thr ⟩ , as well as the temperature and barometric correlation coefficients are evaluated separately for the three detector positions and, in each position, in three ranges of the zenith angle – for nearly vertical muons with $$\cos \theta >0.9$$ cos θ > 0.9 , for nearly horizontal muons with $$\cos \theta cos θ < 0.36 , and for the whole upper hemisphere.

Lead sulfide (PbS) thin films of different morphology were synthesized via direct interaction of lead and sulfur vapors. Low temperature nonequilibrium RF (40.68 MHz) plasma discharge at low pressure ((3–5) × 10–3 Torr) was used for the initiation of chemical interaction between precursors in the gas phase. The in-situ Optical Emission Spectroscopy (OES) was utilized to determine the exited reactive species existing in plasma discharge and possible mechanism of plasma-chemical reactions resulting in the formation of the solid phase. The chemical composition, structure and morphology of the surface of the as-deposited materials in dependence of parameters of the plasma process such as stoichiometry of the precursors in the gas phase, power of the plasma discharge and substrate temperature were characterized by SEM, XRD and AFM analytical techniques. The optical properties and electrophysical parameters of the samples were studied as well.

International audience; Introduction: The current non-invasive tools for the diagnosis of non-alcoholic fatty liver disease (NAFLD) have methodological limitations. We aimed to develop a non-invasive scale to assist in the diagnosis of NAFLD. To achieve our aim, we conducted a secondary analysis of data from a large observational study conducted in Russia.Methods: This retrospective analysis assessed the frequency of NAFLD in the population of patients in the DIREG_L_06725 study, an epidemiological, observational, cross-sectional, multicenter study performed in 50,145 outpatients from 16 Russian cities. Among the cohort of patients diagnosed with NAFLD, we identified factors associated with the risk of NAFLD. To develop a non-invasive tool for diagnosing NAFLD, we also determined the frequency of steatohepatitis.Results: Our analysis included 48,297 patients; NAFLD was present in 20,281 patients (42.0%). The majority (64.1%) were women (80.3% post-menopause), and 87% had a body mass index (BMI) > 27.0 kg/m2. We developed a fully non-invasive scale (St-index) that showed a specificity of 91.4% for ruling in steatosis, and a sensitivity of 93.8% for ruling out steatosis. Multivariate regression analyses conducted in the subgroups of patients aged ≥ 12 and < 18 years and those with BMI < 25.0 kg/m2 produced area under the receiver operating characteristic (AUROC) curve values of 0.8243 and 0.7054, respectively. The factors most strongly associated with the development of NAFLD were age > 35 years, presence of type 2 diabetes mellitus, and a waist circumference/height ratio > 0.54.Conclusion: Our non-invasive steatosis scale, St-index, can help physicians diagnose NAFLD in high-risk patients in the absence of ultrasound data.

With the global warming, the frequent and severe river floods in Arctic regions have affected the distribution of willows in river lowlands. To investigate the effect of floods, especially waterlogging, on nitrogen conditions for willows, we measured their foliar nitrogen content and isotopic composition (δ15N), under various hydrological conditions in Northeastern Siberia, which was classified into four conditions according to the previous study: dry, wet, waterlogging [WL], long-period waterlogging [LWL] respects to willows’ physiological response. The δ15N values of willow leaves, which correlate to those of the soil, were significantly lower under dry (−3.6 ± 1.3‰) and wet (−3.5 ± 1.7‰) than WL (0.3 ± 2.6‰) and LWL (2.7 ± 2.4‰), indicates acceleration of soil nitrogen dynamics for waterlogging. There is no higher foliar nitrogen contents found under LWL (2.3 ± 0.3%) than WL (2.4 ± 0.4%). This might be caused by little decreased nitrogen uptake related to the low activity of carbon fixation in willows under LWL. Interestingly, LWL occurred over a wide area following extreme flooding in 2017; yet, willows survived, whereas potential competing species (larch) died. We further predict that the distribution of willows in Arctic riparian areas will expand, particularly after extreme floods under Arctic amplification.

To assess the efficiency of the method of thermal diagnostics of friction in a system of sliding bearings at shaft speeds of no more than 2π rad/s, friction torque values obtained by solving an inverse heat-transfer problem and measuring with a commercial friction machine sensor have been compared. It has been established that the agreement between the total friction torque values obtained using fundamentally different methods is within 10–15%. The ability of the thermal diagnostics method to identify differing friction torques in each bearing is substantiated by the recovery of their identical values under conditions of difference of the temperature fields in the bearings.

In this work, results of numerical simulation of the interaction of pulsed capillary discharge plasma jets at atmospheric pressure are presented. The interaction of the pulsed plasma jets with a shock wave is considered. Modes with plasma jets created by the capillary discharge with a vaporizing wall expiring through a magnetic nozzle are simulated. Results obtained for several plasma channels are presented together with calculated plasma jets in the capillary discharge with a vaporizing wall.

Omniphobic and icephobic twin-scale surfaces based on the “urchin”-like fluorinated Al2O3 particles are presented. Combined effect of hierarchical topography and fluorination supplied to the surfaces omniphobic and icephobic properties. The study of the stability of the Cassie wetting state is reported. High apparent contact angles were accompanied with the low contact angle hysteresis and high stability of the Cassie air trapping wetting state. Time delay of the ice crystallization as high as $$88\pm 5$$ 88 ± 5 min was established when compared to the ice formation on flat aluminum and non-fluorinated “urchin”-like surfaces. Crystallized water droplets formed on the reported nano-structured surfaces were easily blown out by the air jet with the velocity of $$v=3.0\pm 1.0$$ v = 3.0 ± 1.0 m/s, (which is markedly lower than that common for exploitation of aircrafts and turbines). Heated “urchin”-like surfaces completely restored their omniphobic and icephobic surfaces after thawing. Qualitative analysis of water freezing is supplied.

The promising fields of gallium oxide application are the production of hybrid cars, electrical equipment of high-power, ultraviolet radiation sensors and uninterruptible power supplies. However, the main factor hindering its massive commercial use is the lack of synthesis technologies, that should be cheap, reproducible, and scalable. In this work we develop a novel plasma-chemical method of Ga2O3 synthesis. The high-purity elemental gallium was used as the precursor, which was delivered by argon flow to the reaction zone, where the interaction with iodide pentoxide took place. RF (40.68 MHz) non-equilibrium plasma discharge at low pressure (0.1 Torr) was employed for the initiation of interactions between precursors. Optical Emission Spectroscopy in tandem with quantum-chemical calculations allowed us to find out the reactive species formed in the plasma discharge. The properties of the solid phase obtained were studied as well.

Alumina with an urchin-like morphology has been synthesized from Al2(SO4)3/CO(NH2)2/H2O/isopropanol mixture via hydrothermal route followed by calcination. Raman spectra and SEM images have shown the urchin-like structure to be formed of γ-AlOOH phase with the component ratio Al3+/CO(NH2)2/H2O = 1:(2–3):(100–200). The increase in CO(NH2)2 content has resulted in the formation of needle-like crystals of NH4Al(OH)2CO3. Structural transformations of alumina during hydrothermal synthesis have been investigated by SEM and TEM methods. The 5–10 μm urchin-like alumina particles have been found to be composed of 100–200-nm-thick sheets. The alumina samples have been studied by low-temperature nitrogen adsorption method. The adsorption–desorption isotherms and pore size distributions have shown that pore structure of the urchin-like alumina is formed by the slit pores with two open ends. It has been found that after treatment with chlorosilanes the surface of the urchin-like alumina becomes superhydrophobic, the average contact and sliding angle values being 154° and 5°, respectively. Addition of 5 wt% of the hydrophobized urchin-like alumina particles to the model fire-extinguishing powder has made the powder hydrophobic, the average contact angle being increased up to 151°. Introduction of 5 wt% of the hydrophobized urchin-like alumina particles to ammonium dihydrophosphate has resulted in a decrease in the cohesion strength for ammonium dihydrophosphate fire-extinguishing powder from 0.415 to 0.104 kPa. The hydrophobized urchin-like alumina particles can be used as functional additives to the fire-extinguishing powders for the improved flowability and water repellency to be achieved.

This paper reports on corrosion behavior of different materials under combustion of a nitrogen-based fuel: aqueous solution of ammonium nitrate and urea (UAN). Tested materials include stainless steels 316, 310 and nickel alloys: 600, 601, 617, 800H and RA333. The results were derived under conditions close to those in practical continuous combustion applications. The coupons were positioned in quartz cylinders at temperature 520 ± 10 °C and pressure 10 MPa in the effluent gases. The corrosion of the 316 SS fuel injection tube was tested as a function of the stages that occurred along the tube, namely: heating, ignition, and combustion. Microstructure, chemical composition, depth profile and thickness of the formed oxide scales were studied. High corrosion resistance was found for 310 SS, nickel alloys 601 and RA 333. The heaviest corrosion attack of 316 inlet tube (both general and intergranular) was observed in the area where the exothermic combustion process began.

A theoretical study has been made of the thermal process of welding polyethylene pipes for gas pipelines at low ambient air temperatures. The mathematical model used takes into account the heat of the phase transition in the temperature range, as well as the thermal effect of the fin formed by the slip. Computing experiments have shown that it is possible to control the temperature regime in welding at low ambient air temperatures and provide, in the thermal influence zone, the same change in the temperature field as at permissible air temperatures.

A modified bispectral method is proposed for solving the inverse problem of image reconstruction in ophthalmology. Modeling shows that the method produces stable results for typical symmetric aberrations of the human eye's imaging system in the presence of turbulent distortions leading to a signalternating optical transfer function.

Modern concepts about nanosized conjugates of gold, silver, and iron oxide nanoparticles with antitumor drugs that are intended for chemotherapy of oncological diseases are reviewed. The main possibilities for increasing the safety and efficacy of chemotherapy with the aid of such metal-nanoparticle—antitumor-drug conjugates are shown. Among these possibilities, the most important in practice are targeted drug delivery, controlled drug release, and suppression of multiple drug resistance of tumor cells. An analysis of the advantages and drawbacks of biomedical applications of various metal nanoparticles for antitumor therapy shows good prospects for using conjugates of iron oxide nanoparticles with antitumor drugs, in particular, with doxorubicin. The expediency of creating these nanocomplexes is justified by the possibility of their magnetic-driven delivery, controlled biodistribution, selective toxicity, and relatively simple synthesis.

We report here for the first time on a metal corrosion screening study of a novel nitrogen-based fuel under high temperature and pressure continuous combustion. The fuel consists of an aqueous urea and ammonium nitrate solution. Three austenitic stainless steels (SS) 316L, 310S, 330 were tested for 200 h under 20 MPa. One coupon set was positioned in the hot reactor zone, while a second set was placed in a colder zone. The temperatures in the hot and cooler zones were 745 ± 5 and 545 ± 5 °C, respectively. Microstructure, chemical composition, depth profile, and oxide scale thickness were studied by SEM/EDS and TOF-SIMS analyses. The heaviest corrosion was observed in the hot reaction zone for 316L SS. No protective Cr-rich oxide films were found in the scales formed on all tested SS.

The problem of interpreting results of nonstationary hydrodynamic tests of a vertical well in the presence of an inhomogeneity zone in its vicinity has been considered. It has been shown that the Fourier transform of the seam pressure has complex poles determined by the inhomogeneity parameters. Numerical examples demonstrating the distribution of poles in a complex plane and their contribution to the inverse Laplace transform of the seam pressure are given. In practical applications, the experimental data on the pole parameters can be used to estimate the characteristics of the seam inhomogeneity near the well.

A timing attack exploits the variance in the running time of a crypto-algorithm’s implementation in order to infer confidential information. Such a dependence between confidential information and the running time, called a timing channel, is often caused by branching of the control flow in the implementation’s source code with branching conditions depending on the attacked secrets. We present the Side Channel Finder, a static analysis tool for detection of such timing channels in Java implementations of cryptographic algorithms.

Optimal deposition procedures are determined for nanoparticle size characterization by atomic force microscopy (AFM). Accurate nanoparticle size distribution analysis with AFM requires non-agglomerated nanoparticles on a flat substrate. The deposition of polystyrene (100 nm), silica (300 and 100 nm), gold (100 nm), and CdSe quantum dot (2–5 nm) nanoparticles by spin coating was optimized for size distribution measurements by AFM. Factors influencing deposition include spin speed, concentration, solvent, and pH. A comparison using spin coating, static evaporation, and a new fluid cell deposition method for depositing nanoparticles is also made. The fluid cell allows for a more uniform and higher density deposition of nanoparticles on a substrate at laminar flow rates, making nanoparticle size analysis via AFM more efficient and also offers the potential for nanoparticle analysis in liquid environments.

We have developed a stack of semantics for a high-level C-like language and low-level assembly code, which has been carefully crafted to support the pervasive verification of system software. It can handle mixed-language implementations and concurrently operating devices, and permits the transferral of properties to the target architecture while obeying its resource restrictions. We demonstrate the applicability of our framework by proving the correct virtualization of user memory in our microkernel, which implements demand paging. This verification target is of particular interest because it has a relatively simple top-level specification and it exercises all parts of our semantics stack. At the bottom level a disk driver written in assembly implements page transfers via a swap disk. A page-fault handler written in C uses the driver to implement the paging algorithm. It guarantees that a step of the currently executing user can be simulated at the architecture level. Besides the mere theoretical and technical difficulties the project also bore the social challenge to manage the large verification effort, spread over many sites and people, concurrently contributing to and maintaining a common theory corpus. We share our experiences and elaborate on lessons learned.

The Kets, an ethnic group in the Yenisei River basin, Russia, are considered the last nomadic hunter-gatherers of Siberia and Ket language has no transparent affiliation with any language family. We investigated connections between the Kets and Siberian and North American populations, with emphasis on the Mal’ta and Paleo-Eskimo ancient genomes, using original data from 46 unrelated samples of Kets and 42 samples of their neighboring ethnic groups (Uralic-speaking Nganasans, Enets and Selkups). We genotyped over 130,000 autosomal SNPs, identified mitochondrial and Y-chromosomal haplogroups and performed high-coverage genome sequencing of two Ket individuals. We established that Nganasans, Kets, Selkups and Yukaghirs form a cluster of populations most closely related to Paleo-Eskimos in Siberia (not considering indigenous populations of Chukotka and Kamchatka). Kets are closely related to modern Selkups and to some Bronze and Iron Age populations of the Altai region, with all these groups sharing a high degree of Mal’ta ancestry. Implications of these findings for the linguistic hypothesis uniting Ket and Na-Dene languages into a language macrofamily are discussed.

Total cross sections, angular distributions, and invariant-mass distributions have been measured for the photoproduction of $\pi^0\pi^0$ pairs off free protons and off nucleons bound in the deuteron. The experiments were performed at the MAMI accelerator facility in Mainz using the Glasgow photon tagging spectrometer and the Crystal Ball/TAPS detector. The accelerator delivered electron beams of 1508 and 1557~MeV, which produced bremsstrahlung in thin radiator foils. The tagged photon beam covered energies up to 1400~MeV. The data from the free proton target are in good agreement with previous measurements and were only used to test the analysis procedures. The results for differential cross sections (angular distributions and invariant-mass distributions) for free and quasi-free protons are almost identical in shape, but differ in absolute magnitude up to 15\%. Thus, moderate final-state interaction effects are present. The data for quasi-free neutrons are similar to the proton data in the second resonance region (final state invariant masses up to $\approx$1550~MeV), where both reactions are dominated by the $N(1520)3/2^-\rightarrow \Delta(1232)3/2^+\pi$ decay. At higher energies, angular and invariant-mass distributions are different. A simple analysis of the shapes of the invariant-mass distributions in the third resonance region is consistent with strong contributions of an $N^{\star}\rightarrow N\sigma$ decay for the proton, while the reaction is dominated by a sequential decay via a $\Delta\pi$ intermediate state for the neutron. The data are compared to predictions from the Two-Pion-MAID model and the Bonn-Gatchina coupled channel analysis., Comment: accepted for publication in Eur. Phys. J. A

An experimental study is made into the process of heat transfer from a pulse-superheated probe to a solidified polymer system at probe temperatures above the temperature Td∞ of the beginning of thermal destruction of matter in a quasi-static process. Use is made of the procedures of thermal stabilization of the pulse-superheated probe (with the characteristic time of constancy of superheated probe temperature of 1 ms) and of shock heating (with the characteristic time of increasing the probe temperature of 1 µs and that of monitoring its cooling-down of 1 ms). The effect of short-term thermal stability of polymers in the region of T > Td∞ is revealed. A procedure is developed for identifying the signs of thermal destruction of polymers in the pulsed process. The maximal values are estimated of the density of heat flux through samples without their thermal destruction.

A problem is formulated about how many unit-radius tubes can touch a ball of given radius from the outside and from the inside. Upper bounds for the maximum numbers of contacts are obtained for both interior and exterior contacts. It is also shown that the maximum number of unit-radius tubes touching the same orthogonal cross-section of a particular tube of radius P is [π (arcsin(P+1)−1)−1] and if the number of contacts takes on its maximum, then all tubes are locally aligned.

All volcanic eruptions are accompanied by the degasification of the magma, which results in the growth of gas bubbles in the silicate melt. The number and growth rate of the bubbles determine the character of the eruption. When the free-gas concentration is low, the eruption is weak and takes a short time. At high concentrations, the melt is fragmented and a gas-particle mixture is formed. This results in the catastrophic intensification of the eruption. In this study, for describing the magma flow in a volcano conduit with account for the mass transfer between the bubbles and the melt, we construct models in which the conduit magma flow is considered simultaneously with the dynamics of gas-bubble growth in the melt. The models describe the magma eruptions with equilibrium or weak growth of the bubbles and also with a moderate rate of bubble growth, which is more typical of volcanic systems. Using the models constructed, an intense steady-state eruption and the problem of the evolution of the eruption to the steady-state regime after the rupture of a plug near the top of the conduit are considered. The effect of gas diffusion on the intensity and duration of the eruption is indicated.

Effect of alkylating agent dipin was studied on hematopoietic (CFU-S) and stromal (CFU-F) progenitor cells. Single administration of dipin (0.06 mg/g) to adult (CBA × C57Bl/6) F1 hybrid mice induced a long-term (2 years) oscillations in the numbers of day 7 CFU-S and day 11 CFU-S in the bone marrow and spleen. Dipin also damaged the hematopoietic stroma as indicated by decreased numbers of CFU-F which remained low for at least a year. The capacity of stromal cells to form ectopic hematopoietic foci was considerably decreased and also remained low for 10 months. The obtained data suggest high dipin sensitivity of the earliest hematopoietic and stromal cells. The dynamics of CFU-S numbers in the hematopoietic organs supports their functioning on the basis of clonal succession (Kay, 1965).

The conditions for vapor-phase growth of thin SiC films on silicon substrates are optimized. The thickness of the grown films varies from 100 A to 10 µm, depending on the deposition conditions. The 3C-SiC films grown under the optimal conditions are highly homogeneous, have mirror-smooth surfaces, and adhere well to the substrate.

The first results of studies of special strip and pixel silicon detectors are presented. The detector structures allow the creation of high electrical fields (5 × 105 V/cm) near p–n junctions that are powerful enough to initiate an avalanche multiplication of charge carriers. The possibility of internal amplification in a semiconductor detector similar to the proportional amplification in gas counters is shown. The spectrum of α particles from 238Pu (E α = 5.5 MeV) demonstrates an “amplified” peak at an energy of 70.2 MeV and an energy resolution FWHM = 10.2 MeV.

We studied the properties of cells forming fibroblast colonies from the bone marrow and fetal liver of mouse and rat. Bone marrow and fetal liver cells formed colonies in vitro including fibroblasts as well as a considerable proportion of macrophages. The colonies formed from bone marrow and hepatic cells of rat differed from the murine ones by a higher proportion of fibroblasts. Most colonies derived from the bone marrow of both mouse and rat included a fraction of cells expressing alkaline phosphatase, and hence, capable of osteogenic differentiation; the colonies derived from the fetal liver included low proportions of such cells. The cell layers derived from the colony-forming fibroblasts of both bone marrow and fetal liver of mouse maintained hematopoiesis in the peritoneal cavity of irradiated mice, which indicated that these progenitor cells can form hematopoietic microenvironment.

Preliminary results of an analysis of satellite and ground-based measurements during extremely strong magnetic storms at the end of October 2003 are presented, including some numerical modeling. The geosynchronous satellites Ekspress-A2and Ekspress-A3, and the low-altitude polar satellites Coronas-F and Meteor-3M carried out measurements of charged particles (electrons, protons, and ions) of solar and magnetospheric origin in a wide energy range. Disturbances of the geomagnetic field caused by extremely high activity on the Sun were studied at more than twenty magnetic stations from Lovozero (Murmansk region) to Tixie (Sakha-Yakutia). Unique data on the dynamics of the ionosphere, riometric absorption, geomagnetic pulsations, and aurora observations at mid-latitudes are obtained.

A new experimental program is about to get underway at the Mainz Microtron (MAMI) Facility. The experimental apparatus consists of the famous Crystal Ball together with TAPS detector as a forward wall, and a central tracker. This configuration provides a geometrical acceptance close to 4π combined with good energy and angular resolution in particular for neutral final states. After the energy upgrade of the Mainz Microtron (MAMI-C), the Crystal Ball and TAPS setup will be equipped with a frozenspin polarized target filled with 1H, or 2H to perform new high precision, high statistics measurements of neutral meson production on the nucleon up to 1.5 GeV incident photon energies. In particular it provides a unique opportunity to investigate the GDH sum rule on a neutron target in the contributions by reactions γn →π0 n, γn →π0γ0 n and γn →ŋn.

Results of computational experiments on investigating the efficiency of the algorithm proposed to solve the nonlinear inverse boundary-value problem of restoration of heat release in a plain bearing by measuring the temperature are presented. Simplified three-dimensional models based on the plane thermal model are proposed for practical use of the method of thermal diagnostics of friction in plain bearings as applied to the operated equipment.

A combined spectrometer is composed of a wide-aperture magnetic spectrometer with proportional chambers and a γ-spectrometer based on a Ge(Li) detector. The respective momentum and the angular resolutions of the magnetic spectrometer are FWHM/p(%) = 0.59p (GeV/c) + 1.1 and 0.5–1 mrad; its average efficiency for 0°–5° angles is 85%. The energy resolution of the γ-spectrometer is 8 and 16 keV for 0.5- and 2.0-MeV photons, respectively; the average angular acceptance is 1.5 msr.