bluuebunny/crossref_metadata_2025_split huggingface dataset:
Assessment of energy availability and associated risk factors in professional female soccer players
Authors: Moss Samantha L. , Randell Rebecca K. , Burgess Darren , Ridley Stephanie , ÓCairealláin Cairbre , Allison Richard , Rollo Ian 
Published: July 2020

AbstractThis study aimed to assess energy availability (EA), alongside possible risk factors of reduced or low EA of professional female soccer players during a competitive season. Thirteen players (age: 23.7 ± 3.4 y, stature: 1.69 ± 0.08 m, body mass: 63.7 ± 7.0 kg) engaged in a 5‐day (two rest days, one light training, heavy training and match day) monitoring period. Energy intake (EI) and expenditure during exercise (EEE) were measured. EA was calculated and categorised as optimal, reduced or low (>45, 30‐45, <30 kcal·kg FFM−1·day−1, respectively). Relationships between EA and bone mineral density, resting metabolic rate (RMR), plasma micronutrient status, biochemical markers and survey data were assessed. EA was optimal for 15%, reduced for 62% and low for 23% of players. Higher EA was observed on rest days compared to others (P<0.05). EA was higher for the light compared to the heavy training day (P<0.001). EEE differed significantly between days (P<0.05). EI (2124 ± 444 kcal), carbohydrate (3.31 ± 0.64 g·kg·day−1) and protein (1.83 ± 0.41 g·kg·day−1) intake remained similar (P>0.05). Survey data revealed 23% scored 8 on the Low Energy Availability in Females Questionnaire and met criteria for low RMR (ratio <0.90). Relationships between EA and risk factors were inconclusive. Most players displayed reduced EA and did not alter EI or carbohydrate intake according to training or match demands. Although cases of low EA were identified, further work is needed to investigate possible long‐term effects and risk factors of low and reduced EA separately to inform player recommendations.
Reply to Comment on ‘A note on Purcell’s basic explanation of magnetic forces’
Authors: D’Abramo Germano 
Published: July 2020

Abstract
The article ‘Comment on “A note on Purcell’s basic explanation of magnetic forces”’ (2020 Eur. J. Phys.
41 068001) disputes the validity of the results presented in D’Abramo (2020 Eur. J. Phys.
41 025203). In this reply, we provide several arguments against that criticism and confirm the original conclusions.
EUV spectroscopy of Sn5+–Sn10+ ions in an electron beam ion trap and laser-produced plasmas
Authors: Bouza Z , Scheers J , Ryabtsev A , Schupp R , Behnke L , Shah C , Sheil J , Bayraktar M , López-Urrutia J R Crespo , Ubachs W , Hoekstra R , Versolato O O 
Published: July 2020

Abstract
Emission spectra from multiply-charged Sn5+–Sn10+ ions are recorded from an electron beam ion trap (EBIT) and from laser-produced plasma (LPP) in the extreme ultraviolet range relevant for nanolithographic applications. Features in the wavelength regime between 12.6 and 20.8 nm are studied. Using the Cowan code, emission line features of the charge-state-resolved Sn ion spectra obtained from the EBIT are identified. Emission features from tin LPP either from a liquid micro-droplet or planar solid target are subsequently identified and assigned to specific charge states using the EBIT data. For the planar solid tin target, the 4d–5p transitions of Sn8+–Sn10+ ions are shown to dominate the long-wavelength part of the measured spectrum and transitions of type 4d–4f + 4p–4d are visible in absorption. For the droplet target case, a clear increase in the charge state distribution with increasing laser intensity is observed. This qualitatively demonstrates the potential of using long-wavelength out-of-band emission features to probe the charge states contributing to the strong unresolved transition array at 13.5 nm relevant for nanolithography.
The physics of spontaneous parity-time symmetry breaking in the Kelvin–Helmholtz instability
Authors: Fu Yichen , Qin Hong 
Published: July 2020

Abstract
We show that the dynamical system of an inviscid fluid with velocity shear admits parity-time (PT) symmetry, which provides a physical explanation of the well-known observation that the spectrum of the perturbation eigenmodes of the system is symmetric with respect to the real axis. It is found that the Kelvin–Helmholtz instability is triggered when and only when the PT symmetry is spontaneously broken. The analysis of PT symmetry also reveals that the relative phase between parallel velocity and pressure perturbations needs to be locked at π/2 when the instability is suppressed.
Effect of electrical conduction on the electron emission properties of diamond needles
Authors: Blum Ivan , Borz Mario , Torresin Olivier , Mauchain Julien , Chalopin Benoit , Vella Angela 
Published: July 2020

Abstract
Single crystal diamond needles are promising structures as point electron sources. However, the low electrical conductivity of diamond limits their application as high brightness electron sources. Here we study experimentally and numerically the field emission behavior of single crystal diamond needles, in order to better explain the link between the low electrical conduction, the non-homogeneous field distribution in the needle, the evolution of the field enhancement factor and the saturation of the Fowler–Nordheim plot. Field emission current and voltage loss were measured as a function of the applied voltage. Numerical modelling was used to solve conduction, emission and Laplace equations taking into account the real geometry of the field emitter and its environment. The combination of experimental and numerical results shows that the conduction behavior and the field enhancement factor depend on the diamond geometry. Moreover, the Fowler–Nordheim plot saturation is shown to be affected by the electrostatic environment which can limit the range of voltage losses that can appear along the diamond needle and hence limit the field emission current. At the same time, the increase of the emission current at high field, which is sometimes argued to be caused by the breakdown of the field emitter, is here presented as a simple consequence of the conduction properties of the field emitter as it was already shown for silicon field emitters.
Physical processes in laser ablation into liquid and laser shock wave pinning
Authors: Anisimov S I , Inogamov N A , Khokhlov V A , Petrov Yu V , Zhakhovsky V V 
Published: July 2020

Abstract
The most important modern laser technologies include (i) the generation of colloid nanoparticles (NPs), laser ablation into a liquid (LAL—laser ablation in liquid) and (ii) surface hardening of products by laser pinning (LSP—laser shock peening). Significantly, with laser pinning, the surface to be treated is washed with water. Therefore, the physics of processes during ablation into a liquid and during pinning is common. True, the accents are different. If the ablation in the liquid actually forget about the shock wave (SW) generated by the impact, and leaving the thickness of the target, in the problem with pinning, on the contrary, the main question is about the impact. In addition, the role of water in LAL and LSP is different. In LAL, fluid contributes to the formation of NPs and adopts NPs, gently slowing them, whereas in LSP, water is needed to enhance the recoil and increase the amplitude of the hydrocarbon in the product. The complete picture, developed in the work, of course, should include both edges: the formation of ejection into the liquid as a result of ablation, i.e., LAL, and observation of the SW from the nucleation stage to its attenuation in the product volume, i.e., LSP.
Many-electron effects in secondary radiation generation during the interaction of atoms with intense laser pulses
Authors: Romanov A A , Silaev A A , Frolov M V , Sarantseva T S , Minina A A , Smirnova D A , Vvedenskii N V 
Published: July 2020

Abstract
A parallel program has been developed for numerically simulating the interaction of intense laser pulses with many-electron atoms based on non-stationary Kohn–Sham equations. With the use of this program, we calculate the nonlinear electron currents excited during ionization of argon atoms by intense two-color laser pulses. Based on the comparison with the solution of the time-dependent Schrödinger calculations for hydrogen atoms, the importance of taking into account many-electron effects in simulating the generation of secondary radiation in atomic gases under the action of ultrashort laser pulses is shown.
Study of plasma and particles flows from shock-loaded metal target with lateral lighting by argon explosive lamp
Authors: Kulish M I , Dudin S V , Ushnurtsev A E , Mintsev V B 
Published: July 2020

Abstract
Experimental estimates of the process of the ejection of particles and the formation of plasma during the shock wave exits on the free surface of the cooper sample studied were carried out. The radiation intensity was recorded by a three-channel pulsed pyrometer in an experimental assembly with lateral observation. When the impactor speed was about 5 km/s, a stream of particles and plasma flew from the target surface, the front speed of which reached 12.5 km/s.
Experimental study of spall strength of silicon rubber with microspheres under shock-wave action
Authors: Zubareva A N , Utkin A V , Mochalova V M , Efremov V P 
Published: July 2020

Abstract
In this work, porous media are studied using silicone rubber with glass microspheres as an example. There were investigated three types of silicon rubber samples featuring different concentrations and sizes of microspheres: non-porous silicon rubber, porous silicon rubber with calibrated glass microspheres and porous silicon rubber with glass microspheres having a wide range of sizes. The density of the samples was 0.99, 0.55 and 0.48 g/cm3, accordingly. Investigating spall strength under pulse tension shows that the destruction beginning threshold of the samples in question is quite low. For the non-porous sample, it is around 30 MPa, for the porous ones it is an order of magnitude lower. The spall plate does not come off the sample after the beginning of destruction. The ability of the free surface velocity to change in such a way is typical for materials with a low destruction threshold.
The study of the liquid metal drops fragmentation
Authors: Teplyakov I O , Ivochkin Yu P , Kubrikov K G 
Published: July 2020

Abstract
The main models of the fragmentation of liquid metal droplets in a steam explosion based on thermal stress, shock-acoustic effects and explosive boiling water inside the melt were analyzed. Experimental installations are described and research results are presented. The experiments were carried out with samples of various metals (tin, nickel, zinc, stainless steel), which were heated in levitation mode using an inductor. The maximum temperature for heating a sample of ball-bearing steel did not exceeded 1600 °C. Then, in the molten state, the samples (droplets) fell into a cell filled with distilled water at room temperature. In the experiments, the temperature of the melting sample was monitored and the crushing process was recorded. An experimental material indicating the diversity of the forms of the fragments being formed was obtained. The latter circumstance confirms the assumption of the existence of various fragmentation mechanisms, including the method of breaking drops under the action of intense sound waves caused by the collapse of vapor formations. The results of numerical estimates are given, which indicate that the rate of cooling of particles formed in the process of fragmentation can reach values from 109 to 1010 K/s. These values are quite sufficient for obtaining various alloys with an amorphous structure. The possibility of destruction of vapor shells around hot drops under the action of pressure pulses caused by the collapse of adjacent vapor-gas formations has been experimentally confirmed.
The formation of a detonation wave with multipoint initiation
Authors: Sosikov V A , Torunov S I , Dudin S V , Rapota D Yu , Sokolov N S 
Published: July 2020

Abstract
The results of experimental investigations of the formation of detonation waves with multipoint initiation for the case of a planar and converging cylindrical wave are presented. A special initiation system was used, where the main element was modeled for manufacturing on a three dimensional printer. A solution was found to form a smooth detonation wave for the planar case. Studies of a converging cylindrical detonation wave have shown the need to solve some fundamental issues related to the nonstationarity of such a wave.
Interpretation of experiments on shock compression and isentropic expansion of uranium by quantum molecular dynamics simulations
Authors: Paramonov M A , Minakov D V , Levashov P R 
Published: July 2020

Abstract
In this work, results of quantum molecular dynamics calculations of thermodynamical properties of uranium are presented. The experiments on shock compression and subsequent isentropic expansion of porous samples of uranium are well described. Our first-principle calculations of the shock Hugoniot and release isentropes of uranium demonstrate good agreement with experimental measurements. In addition, unique information of temperature along experimental curves was obtained including supposed entries of isentropes into the two-phase liquid–gas region according to the hypothetical kinks on the experimental isentropes.
Numerical simulations of impact Taylor tests
Authors: Volkov G A , Bratov V A , Borodin E N , Evstifeev A D , Mikhailova N V 
Published: July 2020

Abstract
The finite element method is used for simulation of productivity in dynamic Taylor tests. Two different approaches for prediction of plastic deformation of finite element method is employed for numerical simulation of yielding under dynamic impact Taylor tests. Obtained results of modeling are compared with experimental ones. These are Johnson–Cook model and von Mises yielding criterion enhanced by incubation time approach. The simulation results have shown that the simplest method based on von Mises plasticity model provides good coincidence with experimental profiles of specimen shape in the course of deformation. The shortcoming is that the correct value of yield stress is depending on the loading rate and should be known beforehand. Thus, if there was a method to predict the value of dynamic yield stress to be used within von Mises criterion then this simple approach could be the optimal choice for simulation of dynamic plasticity in conditions of Taylor test.
Flow morphology of two-phase fluid in co-axial capillaries: Numerical simulation
Authors: Vagner S A , Patlazhan S A , Serra C A 
Published: July 2020

Abstract
The dynamic behavior of two-phase Newtonian fluid in co-flow coaxial capillaries was studied numerically. It was found that morphology of the dispersed phase is uniquely described by three non-dimensional parameters as capillary numbers and ratio of Reynolds numbers of the fluid components.
Fully implicit method with lower upper symmetric Gauss–Seidel preconditioner on multiple graphics processing units for hypersonic flows
Authors: Bocharov A N , Bityurin V A , Evstigneev N M , Fortov V E , Petrovskiy V P , Ryabkov O I , Teplyakov I O 
Published: July 2020

Abstract
In the paper, we present implementation and benchmarking for gas dynamic solver for hypersonic flow problems with fully implicit scheme. The aim of the paper is to verify and measure efficiency of the implicit method for computational architecture based on multiple graphics processing units. The verification is performed on a flow over the sphere-cone problem. We consider hypersonic flow regimes of Mach number around 20–30. New results are cross-compared with results of the previous version of the code for explicit time marching scheme.
Diffusion in ultracold strongly coupled multiply charged plasma: Calculation by molecular dynamics method
Authors: Bobrov A A , Bunkov A M , Bronin S Ya , Klyarfeld A B , Zelener B B , Zelener B V 
Published: July 2020

Abstract
We present the results of calculations of electron and ion diffusion by the method of molecular dynamics in an ultracold multiply charged plasma. The calculations were carried out in a wide range of Coulomb coupling parameter. The problems of similarity for a Coulomb multiply charged plasma are discussed. It is shown that in a multiply charged classical plasma for the diffusion coefficients in a wide range of coupling parameter, the similarity assumption is valid.
On dusty plasma formation in Martian ionosphere
Authors: Reznichenko Yu S , Dubinskii A Yu , Popel S I 
Published: July 2020

Abstract
A self-consistent model for the formation and evolution of dusty plasmas in the Martian ionosphere is developed. The effects of the initial distributions of dust particles, as well as condensation and absorption of carbon dioxide and water molecules by dust particles, are studied. Theory values of characteristic sizes of dust grains and their charges are obtained. The theoretical values of the sizes are in agreement with the data of observations. The possibility of the formation of dusty plasma structures in the Martian ionosphere which are analogous to noctilucent clouds in the atmosphere of the Earth is discussed.
Inhomogeneity of a one-dimensional Yukawa system in a trap
Authors: Nikolaev V S , Timofeev A V 
Published: July 2020

Abstract
A system of like charges interacting with a weak repulsive Yukawa potential and confined in a one-dimensional parabolic electrostatic trap is under consideration. It is shown that inter-particle distance in this system grows from the center of the structure to its periphery. The same effect takes place for the mean square displacement of particles from their equilibrium positions, which corresponds to the amplitude of thermal oscillations, and for the value of Lindemann parameter. This leads to different degrees of order for particles located at different distances from the center of the structure. This result might be important for the study of phase transitions in dusty, colloidal and one-component plasmas.
The influence of magnetic field on the geometrical dimensions of dusty structure in striations
Authors: Pavlov S I , Dzlieva E S , Ermolenko M A , Novikov L A , Karasev V Yu 
Published: July 2020

Abstract
The onset of magnetic field on the glow discharge results in the redistribution of plasma flows, which in turn may cause the change of the charge of dust particles levitating in strata. Upon that dusty structure changes its geometric form and inner ordering of particles. In this work, we present the investigation of the influence of magnetic field on dusty structures formed in striation of glow discharge. We detected the variation of geometrical dimensions of structures with magnetic field, and the behavior of interparticle distance was determined. There was obtained the dependence of the concentration of dust particles in normal to vector B cross section of structure on the magnetic induction. Corresponding graph was compared to one of rotation speed, which has three characteristic diapasons. First one is characterized by negative projection of angular velocity Ω on B, two other diapasons are characterized by positive Ω projection and the slope of Ω(B) graph.
Study of plasma jets in plasma focus using the snow-plough model
Authors: Baronova E O , Vikhrev V V , Stepanenko A M , Nikulin V Ya , Silin P V 
Published: July 2020

Abstract
Development of plasma jets (PJ) generated in plasma focus machine is investigated numerically by the snow-plough model. It is shown that axial speed of PJ, V = 5 × 107 cm/s, few times exceeds the speed of thermal plasma expansion. It means that long distance transportation of plasma jets can be achieved. Results of calculations are in good agreement with experimental data obtained by interferometry.
Surface barrier discharge pre-sowing treatment of winter wheat seeds in a three-electrode arrangement with dc bias
Authors: Lazukin A V , Gundareva S V , Nikitin A M , Serdykov J A , Krivov S A 
Published: July 2020

Abstract
In the present work, the experimental results of reaction of morphological indicators (sprout and root length, number of roots, 3-day germination) of seedlings of high quality winter wheat seeds treated by plasma byproducts in the three-electrode system of surface dielectric barrier discharge with dc bias on the third electrode in humid air of atmospheric pressure at different polarity of the bias voltage are shown. The treatment was carried out for 15 min in a strip electrode system (eight 1 mm width strips with 4 mm distance between them, a sinusoidal voltage of 2.7 kV (rms) with a frequency 23 kHz) made on a corundum ceramic barrier (1 mm thickness) with the additional third electrode which is a stainless steel grid distant 10 mm from the surface of the dielectric barrier. Direct-current bias of 8 kV of positive or negative polarity was applied to the third electrode. Seeds were located on the surface of the third electrode. The treatment was also carried out with vibration of the system (the imitation of seeds movement along the third electrode). It is shown that the efficiency of treatment depends on the month of carrying it out. It was succeeded to get a reliable stimulation with weak control. With strong control (potential sowing months) it was not obtained. The imposing of dc bias in any considered case is less efficient than plasma products affection without bias. The vibration of electrode system leads to seeds damage during the treatment and notable germination reduction.
Thermocouple and electric probe measurements in a cold atmospheric-pressure microwave plasma jet
Authors: Chepelev V M , Chistolinov A V , Khromov M A , Antipov S N , Gadzhiev M Kh 
Published: July 2020

Abstract
A cold atmospheric-pressure plasma jet was studied using the novel microwave plasmatron recently developed. Cold plasma jet was generated in Ar flow by electrode 2.45 GHz discharge of up to 200 W power in the portable plasmatron burner (torch) with 2.5 cm diameter outlet. Oscillograms and floating potential dependences on distance from the torch outlet were measured by planar electric probe. Axial and radial distributions of gas temperature in a cold plasma jet were obtained by means of thermocouple method.
Effectiveness of Consumption Sechium Edule on Decreasing Blood Pressure in Elderly with Hypertension in Coastal Area
Authors: Fauziningtyas Rista , Ristanto Arvian Cahya Adi , Makhfudli  
Published: July 2020

Abstract

Sechium edule contains flavonoids and potassium to reducing small blood pressure in the elderly with hypertension. The serving of chayote for consumption can be juiced, steamed, and squeezed. However, no research proves from three serving is more effective in reducing the pressure of elderly hypertension. The aims of the study compared from three presentations which is more useful to make blood pressure decrease in elderly with hypertension in coastal area. This study used Pre-Experimental Design with the three-group pre-post-test design. Samples were 51 elderly obtained from purposive sampling. The independent variable was the consumption of Sechium edule with the various presentation. The dependent variable was the blood pressure. Based on analysis data used paired t-test with significance p-value ≤ 0.05. The mean of blood pressure in the juiced group before intervention was 156.28 mmHg and after intervention 152.48 mmHg (decrease 3.8 mmHg). The mean of systolic pressure in steamed group before intervention was 154.46 mmHg and after intervention 151.43 mmHg (decrease 3.03 mmHg). The mean of systolic pressure in squeezed group before intervention 152.51 mmHg and after intervention 152.14 mmHg (decrease 0.37 mmHg). The juiced Sechium edule was most effective to decrease blood pressure in elderly with hypertension. The nurse can promote to the elderly in the coastal area to make juiced Sechium edule as a non-pharmacological intervention for patient with Hypertension.