bluuebunny/crossref_metadata_2025_split huggingface dataset:
Where is Love? Tidal deformability in the black hole compactness limit
Authors: Chirenti Cecilia , Posada Camilo , Guedes Victor 
Published: August 2020

Abstract
One of the macroscopically measurable effects of gravity is the tidal deformability of astrophysical objects, which can be quantified by their tidal Love numbers. For planets and stars, these numbers measure the resistance of their material against the tidal forces, and the resulting contribution to their gravitational multipole moments. According to general relativity, nonrotating deformed black holes, instead, show no addition to their gravitational multipole moments, and all of their Love numbers are zero. In this paper we explore different configurations of nonrotating compact and ultracompact stars to bridge the compactness gap between black holes and neutron stars and calculate their Love number k
2. We calculate k
2 for the first time for uniform density ultracompact stars with mass M and radius R beyond the Buchdahl limit (compactness M/R > 4/9), and we find that k
2 → 0+ as M/R → 1/2, i.e., the Schwarzschild black hole limit. Our results provide insight on the zero tidal deformability limit and we use current constraints on the binary tidal deformability

Λ

̃

from GW170817 (and future upper limits from binary black hole mergers) to propose tests of alternative models.
emf generated by squeezing an ellipse
*
Authors: Binder P-M , Devedzhiev Kostadin G , Runyan Alexandra T 
Published: August 2020

Abstract
We study the motional emf generated by squeezing an elliptical conducting loop traversed by a constant magnetic field. The circumference of the loop remains constant in the elastic regime, acting as a non-trivial constraint. We numerically find the dependence of one axis of the ellipse on the other and hence calculate the rate of change in area and the ensuing emf. We discuss possible applications of our findings.
Theoretical and experimental study on scattering of low-energy electrons by dimethyl and diethyl ethers
Authors: Tatreau Gillian , Hlousek Borna A , Zawadzki Mateusz , Khakoo Murtadha A , Bardela Fernanda P , Barbosa Alessandra Souza , Bettega Márcio H F 
Published: August 2020

Abstract
We report a joint theoretical and experimental investigation on low-energy electron scattering by dimethyl and diethyl ethers. The experimental elastic differential cross sections were measured at impact energies from 1 eV up to 30 eV and scattering angle range of 10° to 130°. Theoretical elastic differential, integral and momentum-transfer cross sections are calculated at impact energies up to 30 eV, employing the Schwinger multichannel method implemented with norm-conserving pseudopotentials, in the static-exchange and static-exchange plus polarization approximations. Our experimental and theoretical results for dimethyl and diethyl ether are compared with previous data for their isomers, ethanol and butanol, respectively. These comparisons reveal that although the cross sections for the ether and its respective alcohol present similar magnitudes, the angular behavior of their differential cross sections shows some significant differences. From the analysis of the integral cross sections for electron scattering by dimethyl and diethyl ether, we observe a broad structure, at around 9.5 eV, which we assign as the overlap of several resonant structures.
Five texture zeros for Dirac neutrino mass matrices
Authors: Benavides Richard H. , Giraldo Yithsbey , Muñoz Luis , Ponce William A , Rojas Eduardo 
Published: August 2020

Abstract
In this work, we propose new five texture zeros for the mass matrices in the lepton sector in order to predict neutrino masses. In our approach, we extend beyond the standard model (SM) by assuming Dirac masses for the neutrinos, a feature which allows us to make a theoretical prediction for the lightest neutrino mass in the normal ordering. The textures that were analyzed have enough free parameters to adjust the V
PMNS mixing matrix including the CP-violating phase, the neutrino mass squared differences

δ

m

21

2

,
δ

m

31

2

, and the three charged lepton masses. In order to obtain reliable results, we used two different procedures that are based on the weak basis transformation, a well known technique to analyze textures and their implications for flavor physics. The first method was based on a least-squares analysis to theoretically fit the lepton masses and the mixing parameters to their corresponding experimental values; for this case, the best fit obtained for the lightest neutrino mass was

(

3.9

±

0.8

0.6

)

×
1

0

−
3

eV. The second approach was algebraic, resulting in a lightest neutrino mass consistent with the experimental values and the restrictions arising from the five texture zeros of the mass matrices, and the lightest neutrino mass obtained was (3.5 ± 0.9) × 10−3 eV.
Localization to delocalization transition in a double stranded helical geometry: effects of conformation, transverse electric field and dynamics
Authors: Sarkar Suparna , Maiti Santanu K 
Published: August 2020

Abstract
Conformational effect on electronic localization is critically investigated for the first time considering a double-stranded helical geometry (DSHG) subjected to an electric field. In the presence of electric field the DSHG behaves like a correlated disordered system whose site potentials are modulated in a cosine form like the well known Aubry–André–Harper model. The potential distribution can be modulated further by changing the orientation of the incident field. A similar kind of cosine modulation is also introduced in the inter-strand hopping integrals of the DSHG. Suitably adjusting the orientation of the electric field, we can achieve fully extended energy eigenstates or completely localized ones or a mixture of both. The effects of short-range and long-range hopping integrals along with the chirality on localization are thoroughly studied. Finally, we inspect the role of helical dynamics to make the model more realistic. The interplay between the helical geometry and electric field may open up several notable features of electronic localization and can be verified by using different chiral molecules.
Etch characteristics of magnetic tunnel junction materials using H2/NH3 reactive ion beam
Authors: Kim Ju Eun , Kim Doo San , Gill You Jung , Jang Yun Jong , Kim Ye Eun , Cho Hanna , Won Bok-Yeon , Kwon Oik , Yoon Kukhan , Choi Jin-Young , Park Jea-Gun , Yeom Geun Young 
Published: August 2020

Abstract
Magnetic tunneling junction (MTJ) materials such as CoFeB, Co, Pt, MgO, and the hard mask material such as W and TiN were etched with a reactive ion beam etching (RIBE) system using H2/NH3. By using gas mixtures of H2 and NH3, especially with the H2/NH3( 2:1) ratio, higher etch rates of MTJ related materials and higher etch selectivities over mask materials (>30) could be observed compared to those etching using pure H2( no etching) and NH3. In addition, no significant chemical and physical damages were observed on etched magnetic materials surfaces and, for CoPt and MTJ nanoscale patterns etched by the H2/NH3( 2:1) ion beam, highly anisotropic etch profiles >83° with no sidewall redeposition could be observed. The higher etch rates of magnetic materials such as CoFeB by the H2/NH3( 2:1) ion beam compared to those by H2 ion beam or NH3 ion beam are believed to be related to the formation of volatile metal hydrides (MH, M = Co, Fe, etc) through the reduction of M-NHx( x = 1 ∼ 3) formed in the CoFeB surface by the exposure to NH3 ion beam. It is believed that the H2/NH3 RIBE is a suitable technique in the etching of MTJ materials for the next generation nanoscale spin transfer torque magnetic random access memory (STT-MRAM) devices.
Global gyrokinetic simulations of ITG turbulence in the magnetic configuration space of the Wendelstein 7-X stellarator
Authors: Bañón Navarro A , Merlo G , Plunk G G , Xanthopoulos P , von Stechow A , Di Siena A , Maurer M , Hindenlang F , Wilms F , Jenko F 
Published: August 2020

Abstract
We study the effect of turbulent transport in different magnetic configurations of the Weldenstein 7-X stellarator. In particular, we performed direct numerical simulations with the global gyrokinetic code GENE-3D, modeling the behavior of Ion Temperature Gradient turbulence in the Standard, High-Mirror and Low-Mirror configurations of W7-X. We found that the Low-Mirror configuration produces more transport than both the High-Mirror and the Standard configurations. By comparison with radially local simulations, we have demonstrated the importance of performing global non-linear simulations to predict the turbulent fluxes quantitatively.
Realization of wafer-scale single-crystalline GaN film on CMOS-compatible Si(100) substrate by ion-cutting technique
Authors: Shi Hangning , Huang Kai , Mu Fengwen , You Tiangui , Ren Qinghua , Lin Jiajie , Xu Wenhui , Jin Tingting , Huang Hao , Yi Ailun , Zhang Shibin , Li Zhongxu , Zhou Min , Wang Jianfeng , Xu Ke , Ou Xin 
Published: August 2020

Abstract
Heterogeneous integration of gallium nitride (GaN) film on complementary metal-oxide-semiconductor (CMOS)-compatible Si(100) substrate provides a material platform for future high-performance chips with multiple functions. In this work, a 2 inch wafer-scale single-crystalline GaN film is transferred from commercialized bulk GaN wafer onto Si(100) substrate by combining ion-slicing and modified surface-activated bonding with a sputtering-deposited Si nanolayer. The H+ implantation fluence for the exfoliation of GaN film is as low as 2.5 × 1017 cm−2 and the full width at half maximum of the (0002) x-ray rocking curve of GaN film is 203 arcsec. The sliced bulk GaN wafer is recycled, which is beneficial to reduce the cost and to enhance the mass application of the ion-cutting technique to GaN. The exfoliation mechanism of H-implanted GaN is investigated. The activation energy for slicing GaN is only 2.08 eV owing to the high quality of the GaN wafer, while the wide residual damage band is still an obstacle to improving the quality of the GaN film. The successful demonstration of wafer-scale single-crystalline GaN film on Si(100) substrate will be of great benefit to the integration of high-performance GaN devices and Si CMOS integrated circuits with mature processing technology.
DC electric discharge in processes surface polishes of metal products
Authors: Shaidullin A I , Kuputdinova A I , Akhmadullina L I , Gaysin Al F , Gaysin F M , Gaysin Az F 
Published: August 2020

Abstract
An electric discharge of direct current between the jet anode and the metal cathode is studied in the processes of local surface treatment of metal products at atmospheric pressure. The oscillations of the current and voltage of the discharge, the power invested in the discharge are investigated. The surface temperature of the medium in the combustion zone of the discharge was investigated. The microrelief of the product surface was studied before and after electrolyte-plasma treatment.
Study of corona discharge treated poly(ethylene terephtalate) films by atomic force microscopy
Authors: Galikhanov E M , Lyakhovich A M , Luchkin A G 
Published: August 2020

Abstract
The paper studies poly(ethylene terephthalate) films modified in corona discharge. Surface topography and elastic properties of films dependence on the distance between needle and grounded substrate are obtained by atomic force microscopy.
Temperature measurement in the PMMA k-phase during combustion in a high enthalpy flowunder the electrostatic field influence
Authors: Zyryanov I A , Pozolotin A P , Budin A G 
Published: August 2020

Abstract
The purpose of present work is to clarify the mechanisms of the electrostatic field influence on the polymers (PMMA) combustion in high enthalpy flows. For this, the PMMA temperature profiles during combustion in a hybrid rocket engine studies were carried out. Based on the results obtained the assumption about the intensification of the substance entrainment from the polymer surface combusting in a high-enthalpy flow under the electrostatic field influence is confirmed.
Application of low-pressure glow discharge in transverse supersonic gas flow
Authors: Israphilov D I , Israphilov I H 
Published: August 2020

Abstract
Article presents application of glow discharge at low pressures in transverse supersonic gas flow limited in part of discharge region. Mathematical model of supersonic flow in a vacuum chamber described. Results of experiments on realization of glow discharge at low pressures due to the organization of a transverse supersonic gas flow are given.
The ionization waves propagation in a long capillary dielectric tube in the absence of surface charge
Authors: Akishev Yu S , Balakirev A A , Karalnik V B , Medvedev M A , Petryakov A V , Trushkin N I 
Published: August 2020

Abstract
The initiation of the electrical breakdown in a narrow tube filled with a gas under reduced pressure requires the voltage higher compared to that for a much broader tube. Besides, at the fixed applied voltage formally sufficient for breakdown, the probability for the breakdown happening in a narrow tube is far from 100%. This probability can be increased appreciably if to organize the surface ionization waves preceding the volume breakdown in a narrow tube. The breakdown development in a long capillary dielectric tube induced by the surface ionization waves was investigated in this work. The experiments were carried out with the use of a quartz capillary tube with a high aspect ratio of length to diameter. The tube was filled with helium at pressures of 1 - 30 Torr. The pre-posited surface charge on the tube wall was absent. It has been found the completed high-current breakdown between two electrodes located at the ends of the long capillary tube develops with a high probability with the presence of surface ionization waves within the tube.
Application of gas discharge with liquid electrolytic cathode to create flow of steam-water plasma
Authors: Tazmeev G K , Tazmeev K K , Timerkaev B A 
Published: August 2020

AbstractA gas discharge with flowing liquid electrolyte cathode was experimentally investigated under combustion conditions inside an extended chamber with walls made of refractory material. The copper anode was located above the cathode at a distance of 20 cm. The length of the output channel was 50 cm. Heavily diluted aqueous solutions of sodium chloride were used as the electrolyte. The mass velocity of the electrolyte ranged from 8-16 g/s. A three-phase two-half-wave rectifier with voltage at the output of 2100 V served as a power source. The discharge burned stably without a ballast resistor. A plasma flow with mass velocity of 1.0-1.7 g/s in the power range of 25-30 kW was obtained. The total heat loss through electrodes did not exceed 30% of power consumption.
The effect of gas injection on energy characteristics of high-current gas discharge with liquid electrolyte cathode
Authors: Tazmeev K K , Tazmeev A K , Dautov I G 
Published: August 2020

Abstract
A gas discharge with flowing liquid electrolyte cathode was studied experimentally in high-current combustion conditions under conditions of gas injection into the discharge chamber. The interelectrode distance was 20 cm. Aqueous solutions of sodium chloride with specific electrical conductivity of 10–12 mS/cm were used as electrolyte. The discharge current varied within 14-20 A. The studies were carried out with air blowing at a mass flow rate of up to 2.2 g/s. It is shown that air blowing leads to an increase in the discharge current and decrease heat losses through electrodes.
Gas-flame spraying of babbit materials on parts of friction units
Authors: Fedyaev V L , Galimov E R , Kusk O G , Kusk A O , Belyaev A V , Sirotkina L V 
Published: August 2020

Abstract
The questions of applying on the working surfaces of the sliding friction units of babbitt coatings by gas-flame spraying are considered. The operating conditions of babbit bearings are discussed, the main causes and types of their destruction are determined. The widely used technologies for applying babbitt coatings with the method of flame spraying are compared. Experimentally, using the methods of mechanical tests, qualitative and quantitative analysis of the metal structure in control samples, the influence of the main operating parameters of the deposition on the porosity of the babbit coating material, its adhesion to the substrate, wear resistance, and other performance indicators are studied. Rational sputtering distance, the temperature of heating the surface of the substrate before sputtering are established, which ensure optimal values of these indicators. As a result of the analysis of the experimental data, regression relations were obtained characterizing the dependences of the adhesion strength, wear resistance on design (coating thickness), technological (spraying distance), and operational (load, sliding speed) factors.
Study of RF plasma flow at low pressure: electron temperature influence
Authors: Shemakhin A Yu , Zheltukhin V S , Shemakhin E Yu , Pryalukin I S 
Published: August 2020

Abstract
A mathematical model of low-pressure RF plasma flow taking into consideration electron temperature influence is presented. Results of calculations of carrier gas velocity, pressure and temperature as well as electron density and electron temperature in plasma flow are showed. Influence of electric field on electron temperature and plasma flow is analyzed.
Airflow velocity measurement of the electrostatic spray gun
Authors: Fazlyyyakhmatov Marsel , Shaidullin Linar 
Published: August 2020

Abstract
The results of an experimental study of the airflow velocity measurement of the electrostatic spray gun are presented. It has been shown experimentally that airflow velocity rate varies in the range from 1 to 25 m/s depending on the distance from the nozzle of the spray gun and air pressure.
Design and Implementation of DAC Circuit in Waveform Generator
Authors: Zhou Dengrong 
Published: August 2020

Abstract
This article combines the different stages and different levels of various courses such as circuit principle, analog circuit, digital circuit, signal and system, single-chip microcomputer principle, FPGA application and practice, and utilizes the flexibility and interest of the “hardwood classroom” personal multi-functional experimental platform. The simulation design and experimental test of the DAC circuit and signal conditioning and waveform reconstruction circuit in the waveform generator are completed step by step, which fully reflects the process and fun of electronic system design.
Design of High Performance Magnetron Power Supply on the Basis of PWM Power Control
Authors: Li Jianbing , Wu Hao , Xu Tao , Lin Pengfei 
Published: August 2020

Abstract
This paper proposed a kind of high-performance magnetron power supply circuit, the output power of which could be regulated precisely and stably. Based upon the LLC resonant converter with multiplier, efficient power conversion and stable loop control were realized when the switch frequency was near to the resonant frequency. The driving pulses of the switches were controlled by a low-frequency PWM signal, thus realizing the intermittent operation mode. Therefore, the output voltage was in the form of pulsation, which met the requirement of the magnetron. Furthermore, the mean output power of the microwave could be regulated through the PWM duty ratio. An experimental prototype of 1000 W magnetron power supply was completed. As shown in the experiment, the soft switch of this circuit possessed excellent performance. The converting efficiency was higher than 93%; moreover, its output power could be easily adjusted.
Study on the Design of an Optoelectronic Equipment Capable of Detecting Infusion Returns Blood
Authors: Zhu Maolin , Wang Ya , Dong Liming 
Published: August 2020

Abstract
This topic uses photoelectric switch to monitor the characteristics of liquid in the infusion tube to transmit the resistance state. When the transmittance in the infusion tube changes, the signal is captured and fed back to MCU by means of the photoelectric switch to distinguish the return of blood to the infusion tube and the termination of transfusion process or other states. While MCU determines the occurrence of blood returning or the completion of medical transfusion, the alarm reminder function will be triggered. And stepper motor rotates to further clamps the infusion tube to stop the dripping of medicine to prevent the emergence of blood returning, air inflow, etc. The study of this system has a certain research and development value and market potential to alleviate the pain of patients and the burden on family members, greatly improving the work efficiency and fatigue of medical staff.
Research on the Characteristics of Wireless Power Transfer in Ferromagnetic Metal Pipe
Authors: Li Changsheng , Sun Wei , Hu Defu , Liu Yong 
Published: August 2020

Abstract
With the development of society, radio energy transmission technology has been paid more and more attention. However, in the actual application environment, the surrounding metal environment has a significant impact on the radio energy transmission performance. Based on the technology of MRR radio energy transmission, this paper establishes a two coil radio energy transmission model, and analyzes the influence of metal environment on the coil self inductance L, mutual inductance m and coil resistance R of the radio energy transmission system by finite element simulation. On this basis, aiming at the ferromagnetic metal environment, the steel pipe is selected as the research object to study the relationship between coil diameter and mutual inductance in the metal pipe, and the relationship between coil diameter and metal pipe diameter when the maximum mutual inductance is obtained through fitting analysis. At the same time, through the experiment, the mutual inductance between the coils of the wireless energy system in the steel tube is verified, and the experimental results are very consistent with the theory.
Simulation analysis of DC bus short circuit fault in electrochemical energy storage power station
Authors: Ren Hongtao , Zhang Ying , Zheng Shanshan 
Published: August 2020

Abstract
The paper builds a unified equivalent modelling simulation system for electrochemical cells. In this paper, the short-circuit fault of DC bus in energy storage power station is analyzed and simulated. The short circuit of DC bus is composed of three parts: short circuit current provided by energy storage battery, short circuit current provided by power grid and short circuit current provided by DC energy storage capacitor. The factors that affect the amplitude of three kinds of short-circuit current are summarized to provide reference for reducing the DC short-circuit current of energy storage station.