bluuebunny/crossref_metadata_2025 huggingface dataset:
Fetal Echocardiography Indications and Lack of Association between Abnormal Exams and Advanced Maternal Age: A Cross-Sectional Study - Fetal Abnormal Echocardiography
Authors: Silveira Daniela Tarta da , Valete Cristina Ortiz Sobrinho , Lucas Eliane , Herdy Gesmar Volga Haddad
Published: December 2020

Objective To analyze the most frequent referrals for fetal echocardiography, including advanced maternal age and its association with abnormal results.

Methods We included all pregnant women referred to perform fetal echocardiography (gestational age 22–32 weeks) in 2 health centers in Rio de Janeiro, from June 2015 to June 2016. Advanced maternal age was considered when age was > 35 years at the time of delivery). Referral reasons and results were recorded, according to the Brazilian Fetal Cardiology Statement. Crude and adjusted prevalence ratios were calculated (Poisson regression). We considered p < 0.05 as significant.

Results A total of 1,221 tests were analyzed. Abnormal fetal echocardiography was observed in 14.82% of the cases. The most frequent abnormalities were interventricular septal defect (6.39%), septal hypertrophy (3.35%) and atrioventricular septal defect (1.14%). Routine exams were performed in 559 women, 289 were referred for advanced maternal age and 373 were referred according to the Brazilian Fetal Cardiology Statement criteria. An obstetric ultrasound suggesting fetal cardiac abnormality, maternal diabetes, increased nuchal translucency, and obstetric ultrasound suggesting a noncardiac abnormality were strongly associated with an abnormal fetal echocardiography. Abnormal results were not more frequent in women with advanced maternal age when compared with the rest of the study group.

Conclusions It was observed that routine exams and advanced maternal age referrals were very frequent. Those exams were not associated to fetal echocardiography abnormalities. In this scenario, when the obstetric ultrasound suggests a fetal cardiac abnormality, the fetal echocardiography probably is abnormal. Therefore, obstetric ultrasound is a good screening method.
Physical Performance Regarding Handgrip Strength in Women with Polycystic Ovary Syndrome
Authors: Kogure Gislaine Satyko , Ribeiro Victor Barbosa , Gennaro Flávia Ganoa de Oliveira , Ferriani Rui Alberto , Miranda-Furtado Cristiana Libardi , Reis Rosana Maria dos
Published: December 2020

Objective The present study aimed to investigate the physical performance of handgrip strength (HGS) in women with polycystic ovary syndrome (PCOS).

Methods A case-control study that included 70 women with PCOS and 93 age-matched healthy women aged between 18 and 47 years with body mass index (BMI) between 18 Kg/m2–39.9 Kg/m2. The serum levels of total testosterone, androstenedione, insulin, estradiol, thyroid-stimulating hormone (TSH), prolactin, sex hormone-binding globulin (SHBG), and 17-hydroxyprogesterone (17-OHP) were measured. The free androgen index (FAI) and the homeostatic model assessment of insulin resistance (HOMA-IR) were calculated. The body composition regions of interest (ROIs) were assessed by dual-energy X-ray absorptiometry (DXA), and the handgrip strength (HGS) was evaluated for both the dominant and the non-dominant hands with a manual Sammons Preston (Bolingbrook, IL, US) bulb dynamometer.

Results Women with PCOS had high serum levels of total testosterone (p < 0.01), androstenedione (p = 0.03), and insulin (p < 0.01), as well as high FAI (p < 0.01) and HOMA-IR (p = 0.01) scores. Compared with the non-PCOS group, the PCOS group had greater total lean mass in the dominant hand (p < 0.03) and greater HGS in both the dominant and the non-dominant hands (p < 0.01). The HGS was correlated with lean mass (p < 0.01).

Conclusion Women with PCOS have greater HGS. This may be associated with age and BMI, and it may be related to lean mass. In addition, the dominance effect on muscle mass may influence the physical performance regarding HGS in women with PCOS.
The Multigenerational Legacy of Diabetes, Emotional Reactions, and Insulin Adherence
Authors: Scollan-Koliopoulos Melissa
Published: December 2020

Purpose The purpose of this study was to estimate the effect of having a multigenerational legacy of diabetes on insulin adherence by measuring memories of family members’ experiences with insulin self-injection.

Methods A cross-sectional correlational design was implemented by surveying hospitalized adults with type 2 diabetes who recently transitioned to using insulin. Surveys included items about the vividness, frequency, and controllability of memories of a family member self-injecting insulin and concordant emotional reaction, and one’s own emotional reaction to a diagnosis of diabetes and insulin regimen adherence.

Results A diverse sample responded to the surveys. Significant associations were revealed between having a recollection of a family member fearing insulin injections and a negative emotional reaction toward one’s own diabetes diagnosis with suboptimal insulin adherence. Suboptimal insulin adherence may be an indication of avoidance-based coping. Inquiry into how a multigenerational legacy of diabetes influences individual coping styles for diabetes self-management will help clinicians identify patients at risk for suboptimal insulin adherence.
Patient satisfaction with physiotherapists is not inferior to surgeons in an arthroplasty review clinic: non-inferiority study of an expanded scope model of care
Authors: Murphy Michael Thomas , Radovanovic John
Published: December 2020

ObjectiveThis study evaluated whether the satisfaction of patients attending a physiotherapy-led postarthroplasty review out-patient clinic was non-inferior to that of patients attending traditional surgeon clinics.
MethodsUsing a modified nine-item Visit-Specific Satisfaction Instrument (VSQ-9), 50 patients attending the physiotherapy clinic and 50 patients attending surgeon clinics were surveyed. Sample means (±s.d.) were calculated for each domain of the VSQ-9. Non-inferiority testing was performed using 95% confidence intervals (CIs) of the adjusted mean difference to examine whether normalised patient satisfaction scores in the physiotherapy group were no worse than those in the surgeon group.
ResultsBoth groups were satisfied (overall domain; 100% of both groups rated good–excellent). Based on mean item score, there was strong evidence that the satisfaction of the physiotherapy group was non-inferior to that of the surgeon group (adjusted mean difference (physiotherapy – surgeon) in mean score 5.1 (95% CI –0.3, 10.4). Furthermore, the mean differences in all but one of the nine domains were in favour of the physiotherapy group in this study.
ConclusionThe satisfaction of patients attending a physiotherapy arthroplasty review clinic is not inferior to that of patients attending traditional surgeon clinics.
What is known about the topic?A substitution model of care where an advanced practice physiotherapist reviews routine postarthroplasty patients instead of surgeons originated in the UK and has been adopted in Canada and Australia to address the increasingly overloaded public out-patient health services. Evidence of clinical and cost effectiveness has been demonstrated but, to the best of the authors’ knowledge, only one paper has evaluated consumer engagement, and that paper was in a Canadian population.
What does this paper add?This study evaluated the satisfaction of patients in an Australian public healthcare system and was able to demonstrate that patients seen by physiotherapists were no less satisfied than those seen by surgeons in traditional clinics. The findings support those reported in the Canadian study. This is an important step in the development and acceptance of these substitution model of care innovations locally.
What are the implications for practitioners?The results of this study will provide an important addition to the evidence of the clinical efficacy of this model of care: that of consumer acceptance. This will assist with planning, expansion and rollout of similar initiatives in Australia.
Galphimia glauca (goldshower).
Authors: Rojas-Sandoval Julissa
Published: December 2020

Galphimia glauca is a perennial shrub native to Mexico and Central America that has been introduced in tropical and sub-tropical warm regions to be used as a medicinal and ornamental plant. The species has escaped from cultivation and can be found naturalized in grasslands, disturbed sites and along roadsides. Currently it is listed as invasive only in Cuba.
Digitaria fuscescens (yellow crab grass).
Authors: Vélez-Gavilán Jeanine
Published: December 2020

D. fuscescens is an annual, to perennial grass that is a weed of cultivated crops and disturbed soils (Useful Tropical Plants, 2016). It is also a weed of turf grass (Uddin et al., 2012). The species is listed as invasive in Asia (Chagos Archipelago), South America (Colombia, Peru) and Oceania (Fiji, French Polynesia, USA-Hawaii) (PIER, 2016).
Euphorbia umbellata (African milk bush).
Authors: Rojas-Sandoval Julissa
Published: December 2020

Euphorbia umbellata is a succulent shrub, widely cultivated as an ornamental. It grows in dry open woodland, rocky areas and also in disturbed habitats, where it has escaped from cultivation. Currently it is listed as invasive in India and Cuba, although there is no information available about its environmental impacts in either country. In Australia, it is listed as a minor environmental weed.
Spatial radiation features of Thomson scattering from electron in circularly polarized tightly focused laser beams
Authors: Wang Yiqiu , Wang Conglin , Li Kang , Li Lingxiao , Tian Youwei
Published: December 2020

Within the frame of electrodynamic and nonlinearly Thomson scattering, we study the motion and spatial radiation features of a static electron irradiated by circularly polarized tightly focused laser with different laser intensities. Combining the existing

φ
,
θ

and our novel 3D Oxyz coordinate analysis, we find the azimuthal divergence and peak radiation azimuth decrease at varied speeds with laser intensity increasing, whereas both the total radiated power and motion intensity expand tremendously. Furthermore, the relation between angular radiation and electron’s motion is illustrated by investigating the evolvement of radiation’s 2D spectrum and 3D shape. Eventually, by means of separating the motion into two parts, similarities between the trajectory of the later part and Oxyz radiation image provide insights into the spatial coupling and decoupling process in angular radiation.
Quantum field fluctuations in the vicinity of a classical laser soliton
Authors: Fedorov S V , Rosanov N N , Aleksandrov I A , Popov R V , Tumakov D A , Dadeko A V , Vashukevich E A , Baeva A V
Published: December 2020

An analysis of weak quantum fluctuations of a spatial soliton in a laser with fast saturable absorption in the possible presence of weak holding radiation is carried out. In the c-number representation with adiabatic elimination of atomic variables, the master Heisenberg–Langevin equation is linearized in the vicinity of a stable classical (in the absence of fluctuations) laser soliton. The linearized equation’s solution is constructed on the basis of the spectral expansion in eigenfunctions of the evolution operator unperturbed by fluctuations. The discrete spectrum of this operator is found and used to determine the mean values of the squared fluctuations of the coordinates of the soliton center and its momentum. A comparison is made with similar fluctuations in driven interferometers with Kerr non-linearity of the medium.
Ultrametric fitting by gradient descent
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Authors: Chierchia Giovanni , Perret Benjamin
Published: December 2020

We study the problem of fitting an ultrametric distance to a dissimilarity graph in the context of hierarchical cluster analysis. Standard hierarchical clustering methods are specified procedurally, rather than in terms of the cost function to be optimized. We aim to overcome this limitation by presenting a general optimization framework for ultrametric fitting. Our approach consists of modeling the latter as a constrained optimization problem over the continuous space of ultrametrics. So doing, we can leverage the simple, yet effective, idea of replacing the ultrametric constraint with a min–max operation injected directly into the cost function. The proposed reformulation leads to an unconstrained optimization problem that can be efficiently solved by gradient descent methods. The flexibility of our framework allows us to investigate several cost functions, following the classic paradigm of combining a data fidelity term with a regularization. While we provide no theoretical guarantee to find the global optimum, the numerical results obtained over a number of synthetic and real datasets demonstrate the good performance of our approach with respect to state-of-the-art agglomerative algorithms. This makes us believe that the proposed framework sheds new light on the way to design a new generation of hierarchical clustering methods. Our code is made publicly available at https://github.com/PerretB/ultrametric-fitting.
Data-dependence of plateau phenomenon in learning with neural network—statistical mechanical analysis
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Authors: Yoshida Yuki , Okada Masato
Published: December 2020

The plateau phenomenon, wherein the loss value stops decreasing during the process of learning, has been reported by various researchers. The phenomenon was actively inspected in the 1990s and found to be due to the fundamental hierarchical structure of neural network models. Then, the phenomenon has been thought of as inevitable. However, the phenomenon seldom occurs in the context of recent deep learning. There is a gap between theory and reality. In this paper, using statistical mechanical formulation, we clarified the relationship between the plateau phenomenon and the statistical property of the data learned. It is shown that the data whose covariance has small and dispersed eigenvalues tend to make the plateau phenomenon inconspicuous.
Gauges, loops, and polynomials for partition functions of graphical models
Authors: Chertkov Michael , Chernyak Vladimir , Maximov Yury
Published: December 2020

Graphical models represent multivariate and generally not normalized probability distributions. Computing the normalization factor, called the partition function, is the main inference challenge relevant to multiple statistical and optimization applications. The problem is #P-hard that is of an exponential complexity with respect to the number of variables. In this manuscript, aimed at approximating the partition function, we consider multi-graph models where binary variables and multivariable factors are associated with edges and nodes, respectively, of an undirected multi-graph. We suggest a new methodology for analysis and computations that combines the Gauge function technique from Chertkov and Chernyak (2006 Phys. Rev. E 73 065102; 2006 J. Stat. Mech.
2006 P06009) with the technique developed in Anari and Oveis Gharan 2017 arXiv:1702.02937; Gurvits 2011 arXiv:1106.2844; Straszak and Vishnoi 2017 55th Annual Allerton Conf. on Communication, Control, and Computing, based on the recent progress in the field of real stable polynomials. We show that the Gauge function, representing a single-out term in a finite sum expression for the partition function which achieves extremum at the so-called belief-propagation gauge, has a natural polynomial representation in terms of gauges/variables associated with edges of the multi-graph. Moreover, Gauge function can be used to recover the partition function through a sequence of transformations allowing appealing algebraic and graphical interpretations. Algebraically, one step in the sequence consists of the application of a differential operator over gauges associated with an edge. Graphically, the sequence is interpreted as a repetitive elimination/contraction of edges resulting in multi-graph models on decreasing in size (number of edges) graphs with the same partition function as in the original multi-graph model. Even though the complexity of computing factors in the sequence of the derived multi-graph models and respective Gauge functions grow exponentially with the number of eliminated edges, polynomials associated with the new factors remain bi-stable if the original factors have this property. Moreover, we show that BP estimations in the sequence do not decrease, each low-bounding the partition function.
Tractable minor-free generalization of planar zero-field Ising models
Authors: Likhosherstov Valerii , Maximov Yury , Chertkov Michael
Published: December 2020

We present a new family of zero-field Ising models over N binary variables/spins obtained by consecutive ‘gluing’ of planar and O(1)-sized components and subsets of at most three vertices into a tree. The polynomial time algorithm of the dynamic programming type for solving exact inference (computing partition function) and exact sampling (generating i.i.d. samples) consists of sequential application of an efficient (for planar) or brute-force (for O(1)-sized) inference and sampling to the components as a black box. To illustrate the utility of the new family of tractable graphical models, we first build a polynomial algorithm for inference and sampling of zero-field Ising models over K
33-minor-free topologies and over K
5-minor-free topologies—both of which are extensions of the planar zero-field Ising models—which are neither genus- nor treewidth-bounded. Second, we empirically demonstrate an improvement in the approximation quality of the NP-hard problem of inference over the square-grid Ising model in a node-dependent nonzero ‘magnetic’ field.
Project based pedagogy in the development of physical-mathematical thinking
Authors: Gallardo Pérez H J , Villamizar Jaimes D , Maldonado E
Published: December 2020

Physical-mathematical thinking is the visible representation of the relationship between physics and mathematics. It is based on the development of the five types of mathematical thinking and leads to the consolidation of the learning of physics through the construction, interpretation, abstraction and consolidation of meanings for the teacher and the student about physical phenomena. The work allows for the implementation of a pedagogical strategy based on project-based pedagogy, which facilitates the development and application of mathematical algorithms for the analysis, understanding and explanation of physics by students in the context of collaborative field work. The study is framed in the quantitative paradigm, in a quasi-experimental design, working with control and experimental groups. Pre-test is applied to identify the development of physical-mathematical thinking in students and as a support to the design of the intervention proposal. Once the proposal is developed, the results are evaluated by means of a post-test that allows identifying significant improvements in the students’ physical-mathematical thinking.
Diagnosis of road capacity and service level using the highway capacity manual
Authors: Rojas Suárez J P , Orjuela Abril M S , Prada Botia G C
Published: December 2020

Vehicle congestion is a phenomenon that affects the world due to the potential increase in its population. Consequently, the capacity and level of service of Norte de Santander, Colombia, main avenue was analyzed, being the epicenter of the problem. This article was carried out using the highway capacity manual 2000, in addition to collecting information by means of vehicle gauges, conceptualizing the causes and critical points of the sector to diagnose the vehicle situation, proceeding to classify and process according to the highway capacity manual 2000. It is concluded that currently the system is with a level of service D and E, being these unstable, with tolerable speeds in some specific hours, but an incident on the road would cause little mobility, long queues and high waiting times for its narrow road space.
The time-development of energy spectrum of a quantized vortex ring
Authors: Andryushchenko V A , Kondaurova L P
Published: December 2020

The present work is devoted to the study of time dependence of the energy spectrum that is associated with quantized vortex ring movement in the superfluid helium at different temperatures. Temperature changes from 1.3 K to 1.9 K. The full Biot-Savart equation is used to calculate velocity fields. The energy spectrum is calculated by using the method of structure functions. It is established that the structure function amplitude is associated with energy dissipation, while the energy spectrum is independent of temperature and time. The relationship between the energy dissipation rate and the vortex ring length is also discussed.
Studying the efficiency of cooling and resistance of ribbed tubular elements
Authors: Koroleva M R , Saburova E A , Chernova A A
Published: December 2020

The cooling of compressed medium when passing through the set of ribbed tubular elements is numerically investigated. Numerical experiments are carried out with the model of viscous heat conductive turbulent compressed gas by the control volume method with application of different numerical schemes and algorithms. The process of convective heat exchange between the cold ribbed surface and the hot gas flow is studied as well as the heat conductance processes in tubular elements. After processing the obtained results recommendations are given on the arrangement of the set of ribbed tubular elements to provide the assigned temperature characteristics of the cooling system; and the engineering technique of evaluating the thermohydraulic parameters of the cooling system is developed.
The effect of convection on the position of the free liquid surface under zero and terrestrial gravity
Authors: Fedyushkin A I
Published: December 2020

Theresults of numerical modelinghas based on the solution of Navier-Stokes equations for convection oftwo-layer system air-water are presented.The influence of thermo-capillary and gravitational convection on the deformation and time averaged position of the interface of air-water system under sudden lateral heating of a square-section cavity are shown.
The effect of air relative humidity on the evaporation temperature of water-ethanol droplets
Authors: Sterlyagov A N , Nizovtsev M I , Borodulin V Yu , Letushko V N
Published: December 2020

Using the method of infrared thermography, an experimental study of the temperature of evaporating droplets of a water-ethanol solution of different concentrations suspended on polypropylene thread at different air relative humidity was carried out. It is shown that the amplitude of the diminution in droplet temperature during evaporation decreases with an increase in relative air humidity for all considered concentrations of the water-ethanol solution. It is shown that the pattern of decreasing the minimum temperature of cooling of the evaporating droplets with increasing ethanol concentration is characteristic of all the studied air relative humidity. The obtained experimental data are generalized and can be used when calculating the heat and mass transfer of evaporating droplets of the water-ethanol solution.
Numerical modelling of a gas-dust sphere scattering by SPH-IDIC method
Authors: Davydov M N , Stoyanovskaya O P , Glushko T A
Published: December 2020

The paper is devoted to the first application of the SPH-IDIC method to simulation of three-dimensional dusty gas flow. The expansion of a sphere consisting of gas and monodisperse fine dust into vacuum is considered as a model problem. Computing was carried out using graphic accelerators based on nVidia CUDA technology. The numerical simulations show ability of the method to deal with three-dimensional dynamics. We found that in 3D case the method kept all the advantages previously demonstrated on one-dimensional problems: robustness, efficiency and simplicity in implementation.
Experimental applicability limits investigation of Spalart-Almares turbulent model and Reynolds stresses transfer model under control of rotary-divergent flow
Authors: Kabardin I K , Yavorsky N I , Meledin V G , Kh Pravdina M , Gordienko M R , Ezendeeva D P , Kakaulin S V , Usov E V , Klimonov I A , Krotov S V , Bakakin G V , Kabardin A K
Published: December 2020

The work continues the work of the previous year. The mass transfer characteristics were experimentally analyzed in a rotary-divergent flow with inserted blades. The laser Doppler anemometer was used for turbulent mass transfer diagnostics. The experimental investigation was used to verify the numerical calculations. As in previous year the model of Reynolds stress transfer describes the flow in range of flow rates from 50 to 250 n.m3/h more adequately than the Spallart-Almares turbulence model.
Optical properties of polymer-graphene composites coated with gold and silver alloy nanoparticles
Authors: Boyko E V , Kostogrud I A , Smovzh D V
Published: December 2020

The plasmon resonance phenomenon occurring in the system of graphene-polymer-nanoparticles of an alloy of gold and silver is investigated. The possibility of controlling the attenuation of the intensity of electromagnetic radiation passing through the sample by changing the composition and thickness of the deposited coating is shown. For the investigated gold and silver alloy nanoparticles, the highest degree of radiation attenuation falls on the wavelength range from 400 to 600 nm. It was shown that by changing the composition of the nanoparticles (changing the ratio of gold and silver in the alloy), it is possible to achieve the maximum selective light attenuation by more than 2.5 times in the 500 nm region. In the 700 nm region, light attenuation by not more than 2 times is achieved. It was revealed that the use of films with different metal ratios allows us to shift the position of plasmon absorption in the entire visible wavelength range.
Experimental study of the surface tension of highly concentrated boric acid solutions applicable to VVER emergency cooling
Authors: Sakhipgareev A S , Shlepkin A S , Morozov A V
Published: December 2020

The results of the experimental studiesof the surface tension of aqueous solutions of boric acid in a range of concentrations of 2.5-150 gkg−1H2O are presented in the paper.As a result of a literature review, it was foundthe present information about surface tension of boric acid solutions is contradictory and does not cover the entire range of parameters characteristic of a possible emergency at nuclear power plants (NPPs) with the VVER reactor. The technique of the experimental research is described. The results of the measurements of the surface tension of aqueous solutions of boric acid are presented.The existence of the temperature dependence is confirmed.The effect of concentration on the surface tension of aqueous solutions of boric acid in the studied range of parameters is shown.
Study of unsteady thermal conductivity of a package consisting of one layer of equal-size balls
Authors: Dekhtyar R A , Ovchinnikov V V
Published: December 2020

The study of unsteady heat transfer of a package consisting of the equal-size balls was performed at boundary conditions of the first kind. The package was located on a horizontal surface and was limited by the walls of a cylindrical thermostat 129 mm in diameter. The experiments were carried out using glass balls with a diameter of 8.85 mm, 16.0 mm, as well as polyoxymethylene balls with a diameter of 9.0 mm. The package was filled with water. The height of the water layer was equal to the diameter of the balls. In the experiments, the time was determined during which the ball package was heated or cooled to the temperature of the thermostat. It is shown that the time of temperature equalization between the package and the thermostat depends not only on the material and size of the balls but also on the direction of the heat flux. It is shown that the heating time of one layer of equal-size balls is much shorter than the cooling time.
Structure and thermal stability of austenitic steel Fe-17%Cr-12%Ni-2%Mo-0.02%C synthesized by selective laser melting
Authors: Bazaleeva K , Tsvetkova E
Published: December 2020

The structural features of the Fe-17%Cr-12%NI-2%Mo-0.02%C alloy manufactured by selective laser melting (SLM) and the thermal stability of the formed structures are investigated. It is shown that crystallization cells form at SLM, the boundaries of which are volume plexes of dislocations, fixed by segregation of impurity atoms. The microhardness of such a structure is one and a half times higher than that of an alloy of the same composition in a standard hardened state. During annealing up to 800 °C, this cellular structure maintains stability while maintaining hardness indices.
Determination of the Seizure load of copper-based coatings on steel obtained by laser surfacing
Authors: Biryukov V. P. , Starostin D. A. , Klevetov D. V.
Published: December 2020

The paper considers the process of surfacing a copper-based powder PR-BrAlFe 9.5-1, PR-L63, PR-BrSnPb10-1.5 on 40r steel samples using continuous CO2 -laser radiation and cross-beam scanning with a frequency of 227 Hz. It is shown that the jamming load depends on the powder material and processing modes. The influence of transverse beam vibrations on the quality and productivity of the surfacing process is studied.
Metrological method for determining the surface area function of the nanohardness testers tips
Authors: Kazieva T V , Gubskiy K L , Reshetov V N , Kuznetsov A P
Published: December 2020

The paper describes a method for measuring the surface area function of the tips of the probes of nanohardness testers using a laser interferometer. The features of the developed system provide traceability of measurements to the standard of length through the wavelength of a stabilized source of laser radiation. In addition, it is possible to measure the parameters of the probe tip without removing it from the nanohardness tester, which allows the device not to be taken out of working condition and provides unambiguous measurements.
Cleaning the surface of products with glow discharge plasma
Authors: Arustamov V.N. , Ashurov R.KH. , Rotchtein V.M. , Ashurov KH.B. , Khudaykulov I.KH.
Published: December 2020

The paper presents a method for cleaning the surface of products by plasma glow ions. Before applying vacuum-plasma coating methods. The foundations of the evaluation method are formed. Methods of quality control of preparing the treated surface for the coating process based on IR spectra and Raman spectra (Raman spectra) obtained by analytical studies of the surface state of the samples are presented. Based on the analysis of the intensities of the IR and Raman spectra, the dependence of the degree of surface purity of the samples on the cleaning method used is demonstrated.
Properties of graphite to be used as a material for the T-15MD tokamak plasma-facing elements
Authors: Puntakov N A , Ayrapetov A A , Begrambekov L B , Grunin A V , Dovganyuk S S , Kaplevskiy A S , Tenishev A V , Grashin S A , Arkhipov I I
Published: December 2020

The results of the measurement of physical properties, sputtering yield during irradiation by hydrogen ions and a study of surface morphology modification of graphite to be used for the plasma-facing materials of the T-15MD tokamak are presented in this work.
Blocking of annihilation of Frenkel pairs by He atoms
Authors: Degtyarenko N.N. , Pisarev A.A.
Published: December 2020

The results of DFT modelling of blocking the annihilation of Frenkel pairs at small distances between vacancy and self interstitial atom is performed in application to “subthreshold” radiation defects formation in W. It is shown that even at small distances sufficient for spontaneous annihilation of the Frenkel pair, He atoms can suppress the annihilation near the surface. In some cases an additional vacancy can appear close to the surface thus increasing the radiation damage. It is concluded that He impurities can be an additional reason for subthreshold” radiation damage.
Coherent backscattering from an ensemble of Mie-particles immersed in a magneto-active medium
Authors: Gorodnichev E E , Rogozkin D B
Published: December 2020

We show that coherent backscattering of light from a disordered sample in a magnetic field can exhibit unusual features. The helicity retention in scattering from particles of the sample underlies these features. In the magnetic field parallel to the sample surface, the peak of coherent backscattering of circularly polarized light shifts from the backward direction by an angle proportional to the magnetic field strength. For linearly polarized light the coherent backscattering cone splits into two ones. The results obtained correlate well with the available experimental data.
Study of factors affecting the light shift of the CPT resonance
Authors: Chuchelov D S , Tsygankov E A , Vaskovskaya M I , Zibrov S A , Velichansky V L , Petropavlovsky S V , Yakovlev V P
Published: December 2020

Motivated by recent developments in atomic frequency standards employing the effect of coherent population trapping (CPT), we propose a theoretical framework for describing the CPT resonances. Our extended model includes several realistic experimental factors not accounted for in the standard approaches, namely, the FM-based technique for generating the error signal, skewed laser spectrum, etc. We provide a simple yet non-trivial analytical solution revealing the magnitude and structure of the light shift. The performance of the model is checked against numerical simulations, the agreement is good to perfect.
Automation of the construction of the soliton solutions of nonlinear Schrödinger-type equations
Authors: Kutukov A A , Kudryashov N A
Published: December 2020

An algorithm for constructing solitary wave solutions of nonlinear ordinary differential equations which is a variation of the simple equations method has been considered. The program was written in the Maple computer algebra system. The program has been tested on equations describing the propagation of pulses in an optical fiber.
Silicon Carbide 3C-SiC phase band structures calculation in DFT
Authors: Alimov L. E. , Anufriev A. V. , Gurskaya A. V. , Chepurnov V. I. , Puzyrnaya G. V. , Dolgopolov M. V.
Published: December 2020

The 3C-SiC Silicon Carbide phase doped by P, Ga, and N atoms was analyzed in the framework of Density Functional Theory. The physical parameters, changing with time due to N concentration increase, were calculated. Crucial statements about the existence of the deepest level were checked. Calculations of band structures were performed using the software applications VASP and Siesta. The plane wave basis was used in the first case and the orbital basis in the frame of the virtual crystal approach in the second one.
Structure and magnetic properties of the Co2FeAl and Co2NiSi Heusler alloy films
Authors: Malikov I V , Berezin V A , Fomin L A , Perevozchikova Yu A , Bannikova N S , Patrakov E I , Naumova L I , Semiannikova A A , Milyaev M A , Korenistov P S , Marchenkov V V
Published: December 2020

The structural and magnetic properties (field dependences of the magnetization in magnetic fields of up to 6 kOe) of thin-film Co2FeAl, and Co2NiSi Heusler alloys grown by pulsed laser deposition on glass and a single-crystalline Al2O3 R-plane substrate at different growth temperatures (20, 280 and 420 °C) were studied. It was found that the stoichiometric composition of the films depends on the substrate temperature during growth and repeats the composition of the target for films grown at low temperatures. The films deposited on a single crystalline Al2O3 substrate have uniaxial magnetic anisotropy in the plane.
Relationship between electrical resistance and thermal expansion coefficient in YBCO and Ti67Al33
Authors: Palchaev D K , Murlieva Zh Kh , Kh Rabadanov M , Kh Gadzhimagomedov S , Iskhakov M E , Emirov R M
Published: December 2020

Experimental study of thermal coefficients of both electrical resistance and volume expansion in nanostructured superconducting ceramics YBa2Cu3O7-8 and intermetallic Ti67Al33 alloy was performed. In both compounds we found a correlation between the temperature dependences of these coefficients. Formation and relaxation of charge excitations in conductors with a nonmetallic type of interatomic bonds are discussed. We point that, to explain temperature dependence of the conductivity, one should take into account an anharmonicity of atomic vibrations.
Estimation of the charge state of Th implanted in SiO2 in the different atomic environment
Authors: Kurelchuk U.N. , Borisyuk P.V. , Nikolaev A.V. , Tkalya E.V.
Published: December 2020

In this work the investigation of the charge states of thorium implanted in SiO2 is in different atomic environments and at different concentrations is presented.. Th was considered as interstitial and substitutional impurity in model cells of 6, 48 and 96 atoms. The estimations of the Bader effective charges of Th was derived from the electronic charge density n(r) calculated in DFT full relativistic PAW pseudopotential approximation. The change in the electron density of thorium due to the environment in the cells was estimated in comparison with the free atomic state.
The influence of type of the intermolecular interaction potential on transport properties of helium
Authors: Bogdanova Yu A , Maklashova I V , Gubin S A , Amir Zh A
Published: December 2020

A method for calculating the transport properties of helium based on the results of thermodynamic modeling using a theoretically equation of state obtained using perturbation theory is presented. The influence of the type of interparticle interaction potential on the accuracy of calculating the helium’s viscosity and thermal conductivity is shown in comparison with the known experimental data.
Numerical simulation of magnetizing processes of nickel nanowires and nanoballs grown in superfluid helium
Authors: Golenishchev M A , Stepanov M E , Karabulin A V , Matyushenko V I
Published: December 2020

The present work is dedicated to numerical modeling of magnetization processes of Ni nanoparticles ensembles acquired by pulsed laser ablation of metallic target in He II. The characteristic feature of the systems under study is their heterogeneous composition. One fraction of particles is represented by thin nanowires (with diameters of 4 nm strictly) meanwhile the other corresponds to a ball-shaped particles that can obtain diameters from 8 to 500 nm. The model was verified by comparing its calculation results with SQUID-magnetometry data.
Thermodynamic modeling of hydrogen fluid parameters at isentropic and shock wave compression
Authors: Gubin S A , Maklashova I V , Mamedov Z I
Published: December 2020

The thermophysical parameters of hydrogen were calculated based on the model of a theoretically substantiated wide-range equation of state constructed using the potentials of intermolecular interactions Exp-6 using perturbation theory and statistical mechanics relations. The calculation results are consistent with experimental data and calculations of other authors.
Simulation of shock wave produced by detonation of high-explosive charge in a conical shock tube
Authors: Medvedev S P , Khomik S V , Ivantsov A N , Anderzhanov E K , Tereza A M , Mikhailin A I , Silnikov M V
Published: December 2020

Specific features of the flow during the detonation of high-explosive charge in a conical shock tube are revealed by analyzing the results of numerical simulation. It is established that the main difference between the flow in conical geometry and the spherical case is associated with a change in the flow parameters behind the shock wave due to interaction with the bounding surface (cone wall). Comparative analysis of the calculated results shows that the real performance factor of the conical shock tube can vary both over the length and cross-section of the tube.
Analysis of the TAIGA-HiSCORE data
Authors: Samoliga V
Published: December 2020

TAIGA-HiSCORE is an extensive air shower array of 120 Cherenkov detectors spread over an area of 1 km2. It is designed to detect cosmic rays with energies from 50 TeV to 1000 PeV. Also TAIGA-HiSCORE is planned to use for gamma-ray astronomy in cooperation with the other installations of the TAIGA observatory. This work is dedicated to the analysis of the TAIGA-HiSCORE single-mode data. We consider a possibility to detect gamma-ray point source with excess of events from the source direction. For this purpose, a method for estimation of the signal significance is proposed. It takes into account the angular acceptance of the TAIGA-HiSCORE installation. The method is tested on the Monte-Carlo toy model.
Calibration of NICA-MPD electromagnetic calorimeter modules with cosmic muons
Authors: Bhattacharjee M , Tyapkin I , Dabrowska B , Egorov D , Shutov A , Terletskiy A
Published: December 2020

The large barrel-shaped, shashlyk-type electromagnetic calorimeter (ECal) is an important part of the Multi-Purpose Detector (MPD) of the heavy-ion NICA experiment, and is designed to provide spatial and energy measurements for photons and electrons in the energy range from 40 MeV to 2–3 GeV. To deal with the high multiplicity, the ECal is finely segmented and made up of 38,400 cells (‘towers’) which are grouped into modules of 16 ‘towers’ each. ECal projective geometry of the ‘towers’ oriented towards the beam interaction zone results in 8 different types of modules depending on their position in the ECal. As beam calibration of each individual ‘tower’ is time and resource expensive, we discuss our strategy of calibration for the ECal modules with cosmic muons and present some preliminary results.
Implementation of the DAQ software in the ALTI Module of the ATLAS TileCal
Authors: Tlou H
Published: December 2020

The Tile Calorimeter (TileCal) is the central hadronic calorimeter (|η| < 1.7) of the ATLAS experiment, made out of iron plates and plastic scintillators. The TileCal is divided into three barrels along the beam axis, each of which is azimuthally segmented into 64 wedge-shaped modules, staggered in the 0 direction. TileCal online software is a set of Trigger and Data Acquisition (TDAQ) software, and its main purpose is to readout, transport and store physics data originating from collisions at the Large Hadron Collider (LHC). The ATLAS Local Trigger Interface (ALTI) module is a new electronic board, designed for the ATLAS experiment at CERN, a part of the Timing, Trigger and Control (TTC) system. It is a 6U VME module which integrates the functionalities of four legacy modules, currently used in the experiment: Local Trigger Processor, Local Trigger Processor interface, TTC VME bus interface and the TTC emitter. ALTI module will provide the interface between the Level-1 Central Trigger Processor and the TTC optical broadcasting network to the Front-End (FE) electronics of each of the ATLAS sub-detectors. There is a need to develop and integrate the ALTI software in the Tile online software. Performance tests and maintenance of the ALTI module software will be carried out during the Long Shutdown 2 period (LS2), in preparation for Run 3 data-taking period.
Masses of two Higgs doublets within effective theory with four-quark interactions
Authors: Osipov A A , Khalifa M M
Published: December 2020

The composite Higgs scenario in the context of the effective model with SU(2)
L
× U(1)
R
symmetric four-fermion interaction proposed by Miransky, Tanabashi and Yamawaki (MTY) is considered. The low-energy dynamics of the model is described by the effective Lagrangian obtained by the Schwinger-DeWitt technique. The questions of the Nambu sum rule and the spectrum of Higgs states are addressed in detail.
Vibrations of thick domain walls: How to avoid no-go theorem
Authors: Gani V A
Published: December 2020

The asymptotic properties of the stability potentials of kinks with power-law tails are discussed. In particular, in cosmology such kinks can describe “thick” domain walls. The discrete part of the domain wall excitation spectrum, the profile of which is described by a kink solution with one or both power-law asymptotics, cannot contain levels other than zero (translational) mode. Nevertheless, it can be shown that scenarios are quite possible when long-lived localized vibrations will be excited on the domain wall. This, in turn, can affect the processes of interaction of two or more domain walls.
Approaches in centrality measurements of heavy-ion collisions with forward calorimeters at MPD/NICA facility
Authors: Volkov V , Golubeva M , Guber F , Ivashkin A , Karpushkin N , Morozov S , Musin S , Strizhak A
Published: December 2020

The MPD/NICA heavy-ion experiment is now under construction at JINR, Dubna, Russia. The centrality is the global characteristic of the nuclear interactions and reflects the degree of the nuclei overlapping or the number of interacting nucleons. One of the methods to measure the centrality is the determination of the number of non-interacting projectile fragments (spectators) which will be detected by the hadron calorimeters (FHCal) placed at the opposite sides of the beam interaction point. Since the bound spectators escape in beam holes, the central and peripheral collisions have the same spectator’s energy deposition in FHCal. It leads to the ambiguity in the determination of the collision centrality. To resolve this ambiguity a few approaches are developed based on the Monte-Carlo simulations with a few fragmentation models. The methods are based on the combination of both the spatial and the energy distributions of the spectators in the FHCal modules. A few observables for the centrality determination are constructed. Calculation of the transverse/longitudinal energies and the two-dimensional fit of the energy distributions in the FHcal modules make possible the separation of the central and peripheral events. The accuracy of the centrality measurements for a few fragmentation models is estimated.
Upgrade of the QA system in the BM@N experiment at the NICA
Authors: Driuk A V , Mashitsin K I , Merts S P , Nemnyugin S A , Roudnev V A , Stepanova M M
Published: December 2020

The BM@N (Baryonic Matter at the Nuclotron) is an experiment at the NICA (Nuclotron-based Ion Collider fAcility). The first physics runs were carried out with the collection of experimental data in 2018. For the physics analysis of events recorded by detectors of the BM@N the BmnRoot framework is used. It provides a powerful tools for detector performance studying, event simulation, data analysis and developing new algorithms that continually improve this environment. The QA (Quality Assurance) system is used to evaluate the quality of the event reconstruction procedures and collected data. It displays the results of comparing the properties of the simulated events with the reconstructed ones. However, previous version of QA system was nonflexible because its output was just a set of PNG images. Result of QA system modernization by using JSROOT library is described in current report. After this upgrade histograms are displayed in web browser. User can zoom histograms, change scales, get value of bin by moving the cursor on it, etc. It also became possible to get sample mean and standard deviation for each histogram. Upgraded system is quite scalable, so it can easily be extended with new histograms. At the moment, the modernized system is part of the BmnRoot framework.
Chemical freeze-out of light nuclei in high energy nuclear collisions and resolution of the hyper-triton chemical freeze-out puzzle
Authors: Bugaev K A , Vitiuk O V , Grinyuk B E , Yakovenko N S , Zherebtsova E S , Sagun V V , Ivanytskyi O I , Savchenko D O , Bravina L V , Blaschke D B , Farrar G R , Kabana S , Kuleshov S V , Nikonov E G , Taranenko A V , Zabrodin E E , Zinovjev G M
Published: December 2020

We present a summary of the recent results obtained with the novel hadron resonance gas model with the multicomponent hard-core repulsion which is extended to describe the mixtures of hadrons and light (anti-, hyper-)nuclei. A very accurate description is obtained for the hadronic and the light nuclei data measured by STAR at the collision energy

s

N
N

=
200

GeV

and by ALICE at

s

N
N

=
2.76

TeV

. The most striking result discussed here is that for the most probable chemical freeze-out scenario for the STAR energy the found parameters allow us to reproduce the values of the experimental ratios S
3 and

S
¯

3

without fitting.