bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mathematical modelling the interaction of laser pulse with substance for the tasks of proton therapy
Authors: Echkina Eu. , Guzminova N 
Published: December 2019

Abstract
In this paper, we discuss using laser plasma as a source of high-energy ions for the purposes of hadron (proton) therapy. Hadron therapy (HT) is a modern, high-precision form of radiation therapy that uses protons to irradiate diseased tissue. HT has received the greatest use for the fight against cancer. The high accuracy of cancer cell damage, together with the gentlest impact on healthy organs and normal tissues, the absence or mild side effects, make proton therapy indispensable where the tumour is located next to the vital organs, in paediatrics, where the anatomical location of the tumour makes it impossible for surgical removal and use of photon therapy will place the patient at an unacceptable risk. In our work we present the results of mathematical modelling of laser pulse with substance. Computer modelling gives the chance of selection of parameters of a laser pulse and target, for more exact focusing of a pulse and obtaining the set energy of ions.
Computer simulation of the process of magnetic reconnection in the vector configuration
Authors: Echkina Eu. , Inovenkov I 
Published: December 2019

Abstract
Computational simulation of processes or magnetic reconnection an play an important role of studying of laboratory and space plasma. 3D nonlinear magnetohydrodynamic llow us to more accurately describe such phenomena as the current layer, solar flashes, solar wind, magnetic islands in the tokamak. Here we demonstated the results of computer simulation using the parallel algorithm of process of the magnetic reconnection in 3D magnetic configuration.
A Numerical Study of a Modular Sparse Grad-Div Stabilization Method for Boussinesq Equations
Authors: Demir Medine , Kaya Songül 
Published: December 2019

Abstract
This study presents a modular sparse grad-div stabilization method for solving the Boussinesq equations. Unlike the usual grad-div stabilization which produces fully coupled block matrices, the proposed stabilization method produces block upper triangular matrices. Thus, the proposed method is more attractive in terms of both its computational cost and solution accuracy. We provide unconditional stability results for velocity and temperature. Two numerical experiments are performed to demonstrate the efficiency and accuracy of the method.
Fluctuation and evolution of research topics
Authors: Huang Ding-wei 
Published: December 2019

Abstract
We study the shift of global research interests from 1985 to 2016. We consider the 252 research areas in Web of Science and analyse the temporal variation of their rankings. In the last three decades, science dominates over both social sciences and humanities in the high ranks. The average ranking of science continues to rise. In contrast, a decline is observed in both social sciences and humanities. A widening gap is noted between science and humanities. The shift of research interests can be observed in the continuing change of similarity between two distributions from different years. However, the Lorenz curve remains stationary in the last thirty years. The 70/30 rule can be applied, where 70% of annual publications can be attributed to 30% of research areas.
Investigation of dynamics of the IBR-2M pulsed reactor with energy-production up to 1200 MW·day
Authors: Pepelyshev Yu.N. , Popov A.K. , Sumkhuu D. 
Published: December 2019

Abstract
The operation of the IBR-2 pulsed reactor (1987-2006) showed that a total transfer coefficient of the power decreases during the operation of the reactor, therefore each reactor cycle has its own transfer coefficients [1] and stability margins. Hence, the study of dynamics of the new reactor IBR-2M (modernized version IBR-2, since 2011) is extremely important. In this paper, the results of an experimental and a modelling study of dynamics of the IBR-2M are presented, for the reliable and safe operation of reactor. For this purpose, model dynamics of the IBR-2M has been developed, which includes experimental data on reactor feedback parameters in period 2015-2017 at a mean power of 0.5 MW. Using the model dynamics of the IBR-2M, the stability margins of the reactor in different regimes its operation (self-regulating and automatic regulating) were estimated. It shown that during the analyzed time of the operation reactor with energy production up to 1200 MW·day significant changes in dynamics of reactor has not occurred. The reactor has been working in the stability region.
Advances in the project of the gravitational signal generator device to measure the speed of gravity
Authors: Souza M. A. , Coppedé D. , Frajuca C. , Bortoli F. S. , Santos G. A. , Nakamoto F. Y. 
Published: December 2019

Abstract
This work shows the latest improvements in the geometry of the quadrupole mass of a gravitational signal generator device, which should be used in an experiment to measure the speed of gravity. This device must generate a tidal gravitational signal with a frequency of 3200 Hz. The gravitational wave detector Mario Schenberg, developed in Brazil, is the first option as the detector of the signal. The previous steps of the project are briefly discussed, and the new FEM (finite element modeling) simulation for the quadrupole mass is shown. An analysis of the mechanical stresses produced at high speed rotation is presented. The new FEM simulation yields a favorable geometry for the inclusion of the magnetic suspension of the quadrupole mass. The results indicate the feasibility for the continuation of the project and subsequent construction of the real device.
Soliton surfaces induced by the coupled integrable dispersionless equation with self-consistent sources
Authors: Shanina Z. , Myrzakulov R. 
Published: December 2019

Abstract
The coupled integrable dispersionless equations have a signi cant interest because of structure, integrability, and the possibility of obtaining a soliton solution. In this paper, we construct soliton surfaces for integrable dispersionless equation with self-consistent sources in Riemann space. The surfaces, arising from M-XXXII equation and their reduction in R
3, are studied. We obtain Gaussian and mean curvatures and also evaluate the area of surface parametrically de ned with the Riemannian metric. Using the scale transformation and transformation of dependent and independent variables of the coupled dispersionless equations we obtain the equation that describes a current-fed string interacting with an external magnetic eld in three-dimensional Euclidean space.
Soliton surface associated with the WDVV equation for n = 3 case
Authors: Zhadyranova A.A. , Myrzakul Zh.R. 
Published: December 2019

Abstract
This paper describes the soliton surfaces approach to the Witten-Dijkgraaf-E.Verlinde-H. Verlinde (WDVV) equation. We constructed the surface associated with the WDVV equations using Sym-Tafel formula, which gives a connection between the classical geometry of manifolds immersed in R

m
and the theory of solitons. The so-called Sym-Tafel formula simplifies the explicit reconstruction of the surface from the knowledge of its fundamental forms, unifies various integrable nonlinearities and enables one to apply powerful methods of the soliton theory to geometrical problems. The soliton surfaces approach is very useful in construction of the so-called integrable geometries. Indeed, any class of soliton surfaces is integrable. Geometrical objects associated with soliton surfaces (tangent vectors, normal vectors, foliations by curves etc.) usually can be identified with solutions to some nonlinear models (spins, chiral models, strings, vortices etc.) [1], [2]. We consider the geometry of surfaces immersed in Euclidean spaces. Such soliton surfaces for the WDVV equation for n = 3 case with an antidiagonal metric η11 = 0 are considered, and first and second fundamental forms of soliton surfaces are found for this case. Also, we study an area of surfaces for the WDVV equation for n = 3 case with an antidiagonal metric η11 = 0.
Neural net clustering in the study of electrical grids failures in relation to geomagnetic storms
Authors: Siluszyk A , Gil A , Modzelewska R , Moskwa Sz , Siluszyk M , Wawrzynczak A 
Published: December 2019

Abstract
Nowadays, the space weather issues are of a great importance, especially, for all satellites operators or ground-based electrical and electronic systems caused by geomagnetic storms. In spite of many studies on the changeable Sun and the fluctuations in the interplanetary space triggered by solar-driven disturbances, the question, which of the components of geomagnetic storms influence the strongest the electrical and electronic systems is still open. Here, we consider the data of electrical grids breakdowns having unidentified reasons, as well as failures connected to the aging of the infrastructure elements and breakdowns of electronic devices, which occurred during the periods of an increased geomagnetic activity. Mathematical and statistical methods, among them neural net clustering, demonstrate that there exist connections between the groups of the coefficients characterizing the state of Earths vicinity during magnetic storms and the number of failures in electrical network.
Reduced directional coupler through the use of artificial cells
Authors: Letavin Denis A. 
Published: December 2019

Abstract
This paper presents the topology of the directional coupler that carries out the power division of 1 to 3. The area of the proposed device was reduced by 72.5% due to the use of artificial cells, whose characteristics are equivalent to quarter-wave segments, with smaller dimensions. Using the NI-AWR Environment 14 program, the topology of the proposed device was developed, with an operating frequency of 1 GHz and on the FR-4 material. Then, using a photolithography, a prototype of the coupler was made and its characteristics were measured using a R&S vector network analyser.
A Novel Simple Miniaturization Technique for Microstrip Couplers
Authors: Letavin Denis A. , Mitelman Yuriy E. , Chechetkin Victor A. 
Published: December 2019

Abstract
This paper analyzes the new compact design of couplers based on the use of microstrip lowpass filters. The proposed design achieves significant reduction in coupler size while obtaining the same characteristics as of the conventional coupler. Prototype of the coupler with the central frequency of 1 GHz was produced on the substrate with dielectric permittivity of 4.4. The experimental results showed good agreement with numerical simulations. The size of the rat-race coupler was reduced by 83.7%.
Distribution of ionization and tunneling times in a model of strong field ionization
Authors: Lunardi José T. , Manzoni Luiz A. 
Published: December 2019

Abstract
We consider a simple model for strong field ionization and use the Salecker-Wigner-Peres clock to obtain a distribution of (real) times associated with this phenomenon. By coupling the Salecker-Wigner-Peres clock to the particle in different regions, we are able to distinguish between the ionization (exit) time, the tunneling time and the time the particle spends in the well before entering the barrier (the well time). We show that the distribution of ionization/exit times, which are the times usually measured in attoclock experiments, may differ significantly from the distribution of tunneling times, suggesting that the ionization times cannot be generally interpreted as tunneling times.
Application of the random matrix theory to vibrational properties of amorphous solids
Authors: Conyuh D A , Beltukov Y M 
Published: December 2019

Abstract
In this work, we apply the random matrix theory to the study of vibrational properties of disordered systems with a big number of degrees of freedom, such as amorphous solids. Mechanical stability of amorphous solids implies the Wishart ensemble with the positive definite dynamical matrix of the form

M
^

=

B
^

B
^

T

. The translational invariance in amorphous solids leads to the sum rule Σ
i

Bij
= 0, which means non-zero correlations of the matrix elements Bij
. The proposed correlated Wishart ensemble has many universal properties of amorphous solids. One of these properties is the boson peak in the reduced vibrational density of states g(ω)ω
2. The boson peak has been observed in many experiments on amorphous solids, but its nature was not clear so far. We show that the boson peak naturally occurs in the proposed model and find its analytical form.
Evaluating the connectivity, continuity and distance norm in mathematical models for community ecology, epidemiology and multicellular pathway prediction
Authors: Allaerts W 
Published: December 2019

Abstract
The main global threats of the biosphere on our planet, such as a global biodiversity impairment, global health issues in the developing countries, associated with an environmental decay, unnoticed in previous eras, the rise of greenhouse gasses and global warming, urge for a new evaluation of the applicability of mathematical modelling in the physical sciences and its benefits for society. In this paper, we embark on a historical review of the mathematical models developed in the previous century, that were devoted to the study of the geographical spread of biological infections. The basic notions of connectivity, continuity and distance norm as applied by successive bio-mathematicians, starting with the names of Volterra, Turing and Kendall, are highlighted in order to demonstrate their usefulness in several new areas of bio-mathematical research. These new areas include the well-known fields of community ecology and epidemiology, but also the less well-known field of multicellular pathway prediction. The biological interpretation of these abstract mathematical notions, as well as the methodological criteria for these interpretative schemes and their corroboration with empirical evidence are discussed. In particular, we will focus on the boundedness norm in polynomial Lyapunov functions and its application in Markovian models for community assembly and in models for cellular pathways in multicellular systems. Finally, the usefulness of hybrid mathematical modelling in miscellaneous biological, environmental and public health issues will be discussed.
.
Mathematical model of the motion of suspended particles in a turbulent flow and their influence on the motion of an unmanned aerial vehicle
Authors: Shalabayeva Bakyt , Jaichibekov Nurbolat , Kutpanova Zarina , Toleu Altynbek 
Published: December 2019

Abstract
A mathematical model of turbulent motion of a non-homogeneous flow is constructed. Based on the pulsation energy balance method, a closed system of equations is obtained for calculating the average velocity and turbidity of a non-uniform flow. The calculation of the pulsation characteristics of the flow with a transverse shift is carried out and the analysis of the effect of the impurity on the pulsation structure of the turbulent flow and its effect on the motion of an unmanned aircraft is carried out. Since the safety assessment and service lifetime of an unmanned aerial vehicle cannot exclude the influence of disturbances in the atmosphere when calculating characteristics.
Simulation of disruptions triggered by Vertical Displacement Events (VDE) in tokamak and leading edge effect in plasma energy deposition to material surfaces
Authors: Atanasiu Calin V. , Zakharov Leonid E. , Li Xujing 
Published: December 2019

Abstract
The paper describes two major non-linear properties of the vertical instability of a tokamak plasma, which has a vertical elongation: (a) inductive excitation of surface (edge) currents stabilizing the instability and converting it into fast equilibrium evolution, and (b) creation of a wetting zone without the normal component of the magnetic field when the plasma has contact with material surfaces. Two major disruption effects for both mitigated and non-mitigated disruptions, important for JET and ITER, were considered: (a) excitation of vertical disruption during the current quench (i.e., abnormal plasma current ramp down) and (b) related to the wetting zone, potential leading edge effect in plasma energy deposition to the in-vessel tiles during disruptions. Our considerations together with a 2-D version of the VDE (Vertical Disruption Event) code are based on a new mathematical model, called Tokamak MHD (TMHD), as a replacement for the conventional model, a model that cannot solve numerical problems related to extreme plasma anisotropy and negligible mass. The code includes a 3-D model of surface currents on a thin conductive wall and has a well-specified algorithm for extension to vertical disruptions that excite asymmetric kink modes.
Use of Robotic Simulation in the training of Nursing Students of the Faculty of Health Sciences: Perceptions
Authors: Romero A , Valderrama D , González J D 
Published: December 2019

Abstract
Clinical simulation is rapidly becoming an important tool in the training of students who pursue a career in nursing as a viable complement or a substitute for practice with living patients. Although simulation can never replace real clinical practice, it is a useful tool to create realism before performing practical skills during patient care. Robotic simulation can create real scenarios that not only test knowledge, but also provide a safe environment for practicing advanced concepts and difficult patient situations. Members of the nursing faculty often have the challenge of preparing nurses for complex environments and working with interdisciplinary teams. In addition, health care administrators expect a basic competency from new nursing graduates who are prepared to function in the complex work environment independently after orientation. An exploratory and descriptive study was conducted using surveys among the students of the nursing program on the use of a humanoid robot for teaching nursing in the laboratory of practices of the Magdalena University. The results of this study indicate that, in the program and students are positively motivated about the use of technology as a teaching strategy (especially humanoid robots), which suggests a greater exploration of its use in education Nursing.
Boss Tower and Baseplate Flange Optimization
Authors: Bamrungwong Joompon 
Published: December 2019

Abstract
The swaging process is commonly used in head stack assembly, which is a process that is undertaken to either reduce or increase the diameter of tubes or rods. In the head stack assembly process, a swage boss engages with an arm hole of E-Block. Current hard disk drives have very small tolerances, requiring the swage effect of new hard disk drives to be reduced to as little as possible. In this study, finite element analysis (FEA) was used to reduce the swage effect. At present, FEA and investigative tests indicate that a significant portion of gram changing through swaging is caused by E-block tip deformation due to swaging. Deformation of the E-block tip is the result of unbalanced swage forces between the tension and compression suspension. Achieving optimization concepts leads to a new swage plate design to reduce the gramload change of the target and to equalize the swage forces. The FEA results found that gramload change of the target decreased by 35% on the tension side, and by 65% on the compression side through swage by boss tower. The HGA torque out was not different. The suspension flange was also studied. Subsequently, suspension manufacturing is able to bias the suspension as incoming HGA. The flange deformation might be closer to zero after the swaging process.
Simulation of motion of satellites after fixing the values of their accelerations
Authors: Mazitov K D , Yushkov M P 
Published: December 2019

Abstract
At the Department of Theoretical and Applied Mechanics of the Faculty of Mathematics and Mechanics of St. Petersburg State University [1] the theory of motion of nonholonomic systems with linear nonholonomic constraints of high order n<2 was created. The high-order constraints are considered as program and ideal ones, and their reaction force is considered as the required control force. A consistent system of differential equations with respect to unknown generalized coordinates and Lagrange multipliers is constructed to solve the problem. The report examines the motion of Soviet satellites of the systems “Cosmos”, “Molniya”, “Tundra” after fixing the values of their accelerations in apogees. This corresponds to imposing the nonlinear second-order nonholonomic constraints on the further motion of satellites [2, 3]. The equations of constraints are differentiated in time and presented as linear third-order constraints to make it possible to apply the above theory. The motions of satellites are studied in polar coordinates, the origin of this system coinciding with the center of the Earth. It turns out that after fixing the acceleration values in the apogees, the satellites begin to rotate between two concentric circles, alternately touching each of them.
Reduction of inhomogeneous boundary conditions to homogeneous in partial differential equations
Authors: Oblakova T.V. 
Published: December 2019

Abstract
A universal replacement of the variable is proposed, which allows reducing the problem with inhomogeneous boundary conditions of any type to a problem with homogeneous ones. It is shown that due to this replacement the structure of the obtained analytical solutions is significantly simplified. The question of the existence of such a replacement is investigated, examples are given that demonstrate the performance and advantages of the proposed approach for solutions obtained by the Fourier method.
Software Environment for Computer-Aided Heuristic Optimization of Hydraulic Systems for Synchronous Movement of Actuators of Various Functional Purposes
Authors: Bushuev A Yu , Ivanov M Yu , Korotaev D V , Resh G F 
Published: December 2019

Abstract
A software environment was developed for computer-aided design of optimal throttle hydraulic synchronization systems of actuators of various functional purposes operating under conditions of external alternating-sign force effects. The criterion of an optimization procedure was the minimization of a mismatch time of relative movement of actuators during operation. A compute core of an object-oriented code was constructed on the basis of a dynamic mathematical model of a synchronization system consisting of four power cylinders. A model problem was solved with the help of the created software environment. This model problem demonstrated the efficiency of the proposed multidimensional optimization process. The methodology was based on the use of the well-known heuristic method (binary coded genetic algorithm) and the subsequent improvement (in the sense of a given objective functional) of the obtained solution by a method on the basis of the Hooke-Jeeves algorithm. Recommendations on the practical application of the software and mathematical support for achieving the best convergence to the extreme value of a vector of controlled parameters were formulated.
Model of the polarization extinction ratio change due to multiple reflection of laser radiation from the faces of the terbium-gallium garnet crystal in Faraday rotator
Authors: Seleznev A V , Ivanov G Y , Kogut E V , Shaidulin R I , Ryabushkin O A 
Published: December 2019

Abstract
In this work we investigated the phenomena in the Faraday rotator, that can affect the polarization state of transmitting laser radiation. We considered two factors that can cause deterioration of radiation extinction ratio and, therefore, isolation properties of Faraday cell: multiple reflections of radiation from the faces of the TGG crystal and imperfection of the laser beam input relative to the central axis of the crystal. We were able to calculate the impact of these factors on polarization extinction ratio of laser radiation transmitting through the crystal.