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We observed reduction of multiple Coulomb scattering of 855 MeV electrons within a Si crystalline plate w.r.t. an amorphous plate with the same mass thickness. The reduction owed to complete or partial suppression of the coherent part of multiple scattering in a crystal vs crystal orientation with the beam. Experimental data were collected at Mainz Mikrotron and critically compared to theoretical predictions and Monte Carlo simulations. Our results highlighted maximal 7 % reduction of the r.m.s. scattering angle at certain beam alignment with the [100] crystal axes. However, partial reduction was recorded over a wide range of alignment of the electron beam with the crystal up to 15 deg. This evidence may be relevant to refine the modelling of multiple scattering in crystals for currently used software, which is interesting for detectors in nuclear, medical, high energy physics., Comment: 8 pages, 4 figures, submitted to the European Physical Journal C

We describe a homogeneous catalog compilation of common proper motion stars based on Gaia DR2. A preliminary list of all pairs of stars within the radius of 100 pc around the Sun with a separation less than a parsec was compiled. Also, a subset of comoving pairs, wide binary stars, was selected. The clusters and systems with multiplicity larger than 2 were excluded from consideration. The resulting catalog contains 10358 pairs of stars. The catalog selectivity function was estimated by comparison with a set of randomly selected field stars and with a model sample obtained by population synthesis. The estimates of the star masses in the catalogued objects, both components of which belong to the main-sequence, show an excess of "twins", composed by stars with similar masses. This excess decreases with increasing separation between components. It is shown that such an effect cannot be a consequence of the selectivity function only and does not appear in the model where star formation of similar masses is not artificially preferred. The article is based on the talk presented at the conference "Astrometry yesterday, today, tomorrow" (Sternberg Astronomical Institute of the Moscow State University, October 14-16, 2019)., Comment: 18 pages, 10 figures

The method of relativistic molecular dynamics is applied for accurate computational modelling and numerical analysis of the channelling phenomena for 855 MeV electrons in bent oriented silicon (111) crystal. Special attention is devoted to the transition from the axial channelling regime to the planar one in the course of the crystal rotation with respect to the incident beam. Distribution in the deflection angle of electrons and spectral distribution of the radiation emitted are analysed in detail. The results of calculations are compared with the experimental data collected at the MAinzer MIctrotron (MAMI) facility., Comment: 15 pages, 16 figures, submitted to the European Physical Journal Plus (EPJ Plus)

Malnutrition among surgical patients is rather common problem. The degree and severity of malnutrition after surgery significantly correlates with the length of stay in the intensive care unit and surgical hospital, rate of infectious complications development, unsatisfactory results of treatment and increased costs. The presented clinical recommendations clarifies key methods for the prevention of development, diagnosis and treatment of the protein-energy malnutrition (PEM) syndrome in the pre and postoperative period. The choice of methods for diagnosis and PEM correction during the perioperative period is based on studies evaluated from the endpoints of evidence-based medicine. In applications, key quality criteria for treatment, as well as algorithms of actions in the preoperative and postoperative period are presented.

A study of the main indicators of red blood (RBC, HGB, HCT, MCV, MCH) and the concentration of EPO, sTfR in 9 cancer patients with anemic syndrome (AS) against sepsis was carried out. Among them, patients with chronic disease anemia (ACh), with normocytic, normochromic characteristics of red blood cells and low hematocrit predominated. In 2 patients, microcytosis and erythrocyte hypochromia were noted, the concentration of sTfR was significantly higher than normal (0.9 ± 0.07 μg / ml), amounted to 2.7 μg / ml in one of them and 1.9 μg / ml in the other, which testified to t iron deficiency erythropoiesis (IDE) on the background of the ACh,. In 7 patients with ACh without IDE, sTfR values were within the normal range (0.1-1.2) μg / ml, the median was 0.5 μg/ml. In all patients with sepsis, the production of EPO was inadequate for the severity of the AS, to a lesser extent in patients with IDE. The average EPO production in the group was 19.4 ± 5.1 (7.7-52.8) mU / ml, median = 12.1 mE / ml. Further studies of EPO, sTfR are planned in order to determine their role in therapeutic tactics in the correction of AS in cancer patients with sepsis.

Most stars form in binary or multiple systems. Their evolution is defined by masses of components, orbital separation and eccentricity. In order to understand star formation and evolutionary processes, it is vital to find distributions of physical parameters of binaries. We have carried out Monte Carlo simulations in which we simulate different pairing scenarios: random pairing, primary-constrained pairing, split-core pairing, and total and primary pairing in order to get distributions of binaries over physical parameters at birth. Next, for comparison with observations, we account for stellar evolution and selection effects. Brightness, radius, temperature, and other parameters of components are assigned or calculated according to approximate relations for stars in different evolutionary stages (main-sequence stars, red giants, white dwarfs, relativistic objects). Evolutionary stage is defined as a function of system age and component masses. We compare our results with the observed IMF, binarity rate, and binary mass-ratio distributions for field visual binaries to find initial distributions and pairing scenarios that produce observed distributions.

Information on interstellar extinction and dust properties may be obtained from modern large photometric surveys data. Virtual Observatory facilities allow users to make a fast and correct cross-identification of objects from various surveys. It yields a multicolor photometry data on detected objects and makes it possible to estimate stellar parameters and calculate interstellar extinction. A 3D extinction map then can be constructed. The method was applied to 2MASS, SDSS, GALEX and UKIDSS surveys. Results for several high-latitude areas are obtained, compared with independent sources and discussed here.

We report the observation of the steering of 855 MeV electrons by bent silicon and germanium crystals at the MAinzer MIkrotron. 15 $\mu $m long crystals, bent along (111) planes, were exploited to investigate orientational coherent effects. By using a piezo-actuated mechanical holder, which allowed to remotely change the crystal curvature, it was possible to study the steering capability of planar channeling and volume reflection vs. the curvature radius and the atomic number, Z. For silicon, the channeling efficiency exceeds 35 %, a record for negatively charged particles. This was possible due to the realization of a crystal with a thickness of the order of the dechanneling length. On the other hand, for germanium the efficiency is slightly below 10 % due to the stronger contribution of multiple scattering for a higher-Z material. Nevertheless this is the first evidence of negative beam steering by planar channeling in a Ge crystal. Having determined for the first time the dechanneling length, one may design a Ge crystal based on such knowledge providing nearly the same channeling efficiency of silicon. The presented results are relevant for crystal-based beam manipulation as well as for the generation of e.m. radiation in bent and periodically bent crystals., Comment: 12 pages, 10 figures, submitted to Eur. Phys. J. C

Accretion disks around young binary stars are subject to strong forces exerted by the system components. Gas–dynamical interactions excite strong non-linear perturbations in the disk, which can give rise to turbulence. This study considers a mechanism for the excitation of turbulence based on the instability of non-linear waves in a rotating flow. It is shown that the spectrum of non-linear perturbations excited in the inner part of the disk leads to turbularization of the flow. Estimates of the Shakura–Syunyaev index, α ∼ 0.01−0.05, are obtained for use in numerical models of accretion disks.

On 27 June, a 1–2-m high wave struck the beaches of Odessa, the third largest Ukrainian city, and the neighbouring port-town Illichevsk (northwestern Black Sea). Throughout the day, prominent seiche oscillations were observed in several other ports of the Black Sea. Tsunamigenic synoptic conditions were found over the Black Sea, stretching from Romania in the west to the Crimean Peninsula in the east. Intense air pressure disturbances and convective thunderstorm clouds were associated with these conditions ; right at the time of the event, a 1.5-hPa air pressure jump was recorded at Odessa and a few hours earlier in Romania. We have utilized a barotropic ocean numerical model to test two hypotheses: (1) a tsunami-like wave was generated by an air pressure disturbance propagating directly over Odessa (‘‘Experiment 1’’) ; (2) a tsunami-like wave was generated by an air pressure disturbance propagating offshore, approximately 200 km to the south of Odessa, and along the shelf break (‘‘Experiment 2’’). Both experiments decisively confirm the meteorological origin of the tsunami- like waves on the coast of Odessa and imply that intensified long ocean waves in this region were generated via the Proudman resonance mechanism while propagating over the northwestern Black Sea shelf. The ‘‘Odessa tsunami’’ of 27 June 2014 was identified as a ‘‘beach meteotsunami’’, similar to events regularly observed on the beaches of Florida, USA, but different from the ‘‘harbour meteotsunamis’’, which occurred 1–3 days earlier in Ciutadella (Baleares, Spain), Mazara del Vallo (Sicily, Italy) and Vela Luka (Croatia) in the Mediterranean Sea, despite that they were associated with the same atmospheric system moving over the Mediterranean/Black Sea region on 23–27 June 2014.

This paper discusses the initiative of implementing a GPU-based numerical algorithm for studying various phenomena associated with dynamics of a high-speed railway transport. The proposed n...

The development of high-energy electromagnetic showers in long oriented lead tungstate crystals, accelerated by the effects induced by the strong field of atomic strings, is simulated for the first time. For that the characteristics of pair production and gamma-radiation by electrons or positrons were first simulated by the direct application of Baier-Katkov formulae in a thin PWO crystal to derive the scaling coefficients of the corresponding Bethe-Heitler cross sections to be incorporated into GEANT4 for the simulation of the electromagnetic shower development in a long crystal. Simulation results demonstrate the significant influence of the crystal structure on the e± and gamma-quanta registration processes in the existing homogeneous electromagnetic calorimeters and gamma-telescopes as well as wide possibilities of improving their performance in future developments.

In this Erratum, an improved simulation of the channeling efficiency of protons and antiprotons as a function of the particle momentum is shown in for different configurations

The production techniques of radioisotopes for medical purposes is a valuable and important field in nuclear medicine. In particular, the expensive cost of the prime materials for the production via cyclotron obliges the search for new solutions to enhance the production rate with minor upgrades of the current instrumentation. Oriented ordered structure can modify particle trajectories inside a medium leading to a sensible variation of the interaction rate with atomic nuclei. Under specific orientations of the target with respect to the incident beam, the probability of inelastic interaction with nuclei can be enhanced with respect to the standard rate. This effect is called anti-channeling and leads to an increase of the radioisotope production yield. A dedicated set of experimental measurements were carried out at the CN accelerator of the INFN Legnaro Laboratories to investigate nuclear reactions under channeling experiments. In particular, the production of the Arsenic-74 radioisotope through a proton beam delivered to a natural single-crystal Germanium target was monitored via γ-spectroscopy of the prompt γ-rays upon de-excitation of produced nuclei, in order to quantify the production rate variation as a function of the incident angle.

The interaction rate of a charged particle beam with the atomic nuclei of a target varies significantly if the target has a crystalline structure. In particular, under specific orientations of the target with respect to the incident beam, the probability of inelastic interaction with nuclei can be enhanced with respect to the unaligned case. This effect, which can be named antichanneling, can be advantageously used in the cases where the interaction between beam and target has to be maximized. Here we propose to use antichanneling to increase the radioisotope production yield via cyclotron. A dedicated set of experimental measurements was carried out at the INFN Legnaro Laboratories with the AN2000 and CN accelerators to prove the existence of the antichanneling effect. The variation of the interaction yield at hundreds of keV to MeV energies was observed by means of sapphire and indium phosphide crystals, achieving an enhancement of the interaction rate up to 73% and 25%, respectively. Such a result may pave the way to the development of a novel type of nozzle for the existing cyclotrons, which can exploit crystalline materials as targets for radioisotope production, especially to enhance the production rate for expensive prime materials with minor upgrades of the current instrumentation.

We present the crystalrad simulation code, combining all the features of the crystal simulation code for simulations of charged particles trajectories in a bent crystal and the radcharm++ code for calculation of the radiation spectrum. The crystalrad code is based on Monte Carlo simulations of trajectories in the planar and axial electric field either in a straight, bent, or periodically bent crystal taking into account multiple and single Coulomb scattering on nuclei and electrons, nuclear scattering and ionization energy losses. The trajectories simulated are used for calculation of radiation spectra by the Baier-Katkov method. We compare our simulations with experimental data taken at MAMI (MAinzer MIkrotron) as well as give an example for a possible future study with sub-GeV electrons interacting with Si bent crystals.

Short-period crystalline undulators have the potential to enable intense and monochromatic sources of hard X and $\ensuremath{\gamma}$ radiation. Three crystalline undulators were manufactured and their structural properties were characterized at the ESRF x-ray light source. In particular, a crystalline undulator consists in a periodically bent crystal in which channeled electrons or positrons follow the bending of the crystalline planes, thus generating electromagnetic radiation in analogy with standard magnetic undulators. State-of-the-art magnetic undulators can be built with a period of no less than a few cm. On the other hand, a crystalline undulator could be built with a period down to the sub-mm range. Thus, a crystalline undulator would allow generating harder photons. Since the radiator consists of a small crystal, a crystalline undulator is a valid and low-cost alternative for intense hard radiation production at electron accelerator facilities. The three samples were realized at the INFN laboratory of Ferrara, Italy, through the grooving method, namely a method developed to induce a self-standing and adjustable deformation to a crystal. The samples showed a uniform and sinusoidal curvature, thus proving that the grooving method is suitable for building crystalline undulators.

Creation of the Galaxy model describing formation and evolution of binary stars requires generating and testing hypotheses related to the process of formation of binary stars and distributions of their characteristics. A set of hypotheses can be generated on the basis of a number of publications that suggested the formation of binary systems. We describe the project aimed at finding initial distributions of binary stars over masses of components, mass ratios of them, semi-major axes and eccentricities of orbit, and also pairing scenarios by means of Monte-Carlo modeling of the sample of visual binaries of luminosity class V with a set of additional restrictions, so it can be considered as free of observational incompleteness effects. We present results which allow rejecting some estimated initial distributions of visual binary star parameters.

The time dependence of the potential difference that appears between two VT6 titanium alloy plates separated by a mixture of epoxy resin with an epoxy hardener is studied. One of the plates is placed in epoxy resin until equilibrium is established, and the second plate is coated with an as-prepared mixture of epoxy resin and a hardener. It is found that the potential difference decreases in time because of charge transfer by Ti2+ ions through epoxy resin. Photoluminescence and infrared absorption spectra of epoxy adhesive on the VT6 alloy surface are recorded. Their analysis shows that the Ti2+ ions having penetrated into the as-prepared mixture of epoxy resin and a hardener interact with CN groups in adhesive molecules to form coordination compounds. As a result, a diffusion layer saturated with coordination compounds forms at the alloy/adhesive interface, which leads to an increase in the strength of the adhesive.

The potential difference that appears in the epoxy resin located between two grade 3 steel plates is studied. One of them is stored in epoxy resin to reach equilibrium, and the second plate is coated with an asprepared mixture of epoxy resin with a hardener. It is found that the potential difference decreases in time because of charge transfer by Fe2+ ions through epoxy resin. The luminescence and infrared absorption spectra of the epoxy adhesive on the grade 3 steel surface are recorded. An analysis of these spectra shows that Fe2+ ions penetrate into the as-prepared mixture of epoxy resin with the hardener, and interact with CN groups in the mixture, and form coordination compounds. As a result, a diffusion layer saturated by the coordination compounds forms at the interface between the steel and the adhesive.

A method for analyzing the transverse beam feedback circuit in a ring accelerator and selecting its parameters using the concept of the active beam coupling impedance, which is externally imposed and controlled, is described. This approach is used for the physical substantiation of approaches to upgrading two operational transverse feedback systems that are available in the U-70 synchrotron of the Institute for High Energy Physics, National Research Centre Kurchatov Institute: narrow-band analog and broadband digital systems. Both systems were subjected to deep upgrading, which is based on this method, and were successfully commissioned in 2007 and 2011, respectively. A brief description of their updated engineering implementation is given. The presented experimental results confirm the adequacy of the impedance approach to designing and adjusting the transverse beam feedback circuits in the U-70 synchrotron.