bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gauge/frame invariant variables for the numerical relativity study of cosmological spacetimes
Authors: Ijjas Anna 
Published: June 2023

Abstract
To numerically evolve the full Einstein equations (or modifications thereof), simulations
of cosmological spacetimes must rely on a particular formulation of the field equations combined
with a specific gauge/frame choice. Yet truly physical results cannot depend on the given
formulation or gauge/frame choice. In this paper, we present a resolution of the gauge problem
and, as an example, numerically implement it to evaluate our previous work on contracting
spacetimes.
Transport and acceleration mechanism of fast ions during edge localized modes in ASDEX Upgrade
Authors: Rivero-Rodríguez J.F. , Galdon-Quiroga J. , Domínguez-Palacios J. , García-Muñoz M. , Garcia-Vallejo D. , Gonzalez-Martin J. , McClements K.G. , Sanchís L. , Särkimäki K. , Snicker A. , Todo Y. , Velarde L. , Viezzer E. 
Published: June 2023

Abstract
Observations of enhanced fast-ion losses during edge localized modes (ELMs) have been reported in the ASDEX Upgrade tokamak, revealing losses above the injection energy. This suggests that fast ions can be accelerated and lost due to the ELMs. Recent analysis of the ELM-induced losses suggests that the fast ions are lost due to a resonant interaction with the electromagnetic perturbation during the ELM crash. The fast-ion transport and acceleration during ELMs is modelled using electromagnetic fields computed using the hybrid kinetic-MHD code MEGA, while fast-ion full orbits are tracked with the ASCOT code. Time-evolving 3D electromagnetic fields have been implemented in ASCOT to compute fast-ion orbits in the presence of fast MHD events such as ELMs. The simulations successfully reproduce a field-aligned pattern of the losses on the tokamak wall and the formation of an accelerated population in the lost fast-ion distribution, while they predict an accelerated population in the confined distribution. A parametric study of the fast-ion constants of motion suggests a resonant interaction between the fast-ions and the electromagnetic fields arising during the ELM crash. In the case of fast-ion acceleration, the perpendicular electric perturbation, with scales smaller than the fast-ion gyroradius, breaks magnetic moment conservation and resonantly modifies the fast-ion energy.
Test and simulation of mechanical properties of a lightweight adaptation device
Authors: Zhang Mingyang , Zhang Yongqing , Tang Haozhen , Lyu Duojun 
Published: June 2023

Abstract
Based on carbon fiber, extruded polystyrene foam (XPS), ethylene vinyl acetate plastic foam (EVA), and other materials, a lightweight fitting device is designed. Its mechanical properties are tested and simulated. The experimental results and simulation are consistent. The adaptive device adopts a lightweight design, and the single piece weight is less than 30 kg. The final height of the adaptive device can be changed through manual stacking and combination to meet different application scenarios. The adaptive device also adopts a modular design, which separates the bearing function from the adaptive function. The bearing module meets the bearing demand, while the adaptive module has good deformation capacity. The device can be repeatedly used for the safe and fast transfer of heavy equipment.
Bubble dynamics and cavitation damage to curved elastic boundaries
Authors: Liu Can , Hu Jiwen , Xie Yaqian , Liu Yong , Lei Weirui 
Published: June 2023

Abstract
Prediction of cavitation damage to the solid boundary is crucial in the application of ultrasound. The goal of this study is to investigate the potential for a cavitation bubble to cause mechanical effects on the curved elastic boundary and contribute to the understanding of the mechanisms of bubble-structure interaction. Effects of the surface curvature of the boundary are studied using the finite volume method. In the oscillatory migration of bubbles to the bottom of the boundary, there are several shape modes at the same time. The wall stress/deformation produced by impinging jets increases with parameter α. The bubble dynamic behaviors and the wall deformation have no significant effect as Young’s modulus equals or exceeds 60 MPa. Boundary deformation generated by tensile and compressive stresses during bubble collapse may be the basic mechanism of cavitation erosion. Due to the lack of visual observation and research on the acoustic cavitation effect, the key mechanism of ultrasonic cavitation is missing. Therefore, the importance of bubble dynamics and cavitation damage in this paper is self-evident
The collision performance of jack-up marine platforms based on pile-soil coupling technology
Authors: Liang Enqiang , Kong Jiali , Zheng Minghui , Li Shengtao 
Published: June 2023

Abstract
The truss jack-up offshore platform has become the main force of offshore oil and gas development with its stable operation ability and environmental adaptability. Meanwhile, along with the development of the offshore shipping industry, collisions between ships and offshore platforms have become more and more frequent. Therefore, it is important to study the collision performance of truss jack-up offshore platforms. Based on the “pile-soil” coupling technology, the non-linear finite element software ABAQUS is used to establish the pile-leg collision calculation model. The key parameters, such as damage deformation, collision force, and energy absorption, are analyzed through the analysis. The collision performance of the trussed offshore platform is analyzed through the calculated damage deformation, collision force, energy absorption, and other key parameters. The research results show that the collision between the ship and the marine platform has obvious local characteristics. In addition, the strength of the spar in the collision area can be increased appropriately to improve the collision performance of the platform effectively.
Optimization of brazing process and structure lightweight design for diamond microchannel
Authors: Fang Kun , Song Kuijing , Lin Tiesong , Jiang Haitao 
Published: June 2023

Abstract
The application of diamond material significantly improves the heat dissipation capability of liquid cooling microchannels, solving the bottleneck problem of heat dissipation for highly integrated electronic components and thus promoting the development of a new generation of military electronic equipment. In this study, diamond microchannels with ultra-high heat flux density were reliably vacuum-brazed by using AgCuTi filler metal in a high vacuum furnace. Microstructure and properties of diamond brazing joints were studied and effect of brazing temperature and time was analyzed. The optimal brazing process parameters were obtained as follows: a vacuum level of <1×10−5 Pa, brazing temperature of 840°C, brazing pressure of 0.5–3 bars and holding time of 10 min. Following vacuum-brazing experiment, the brazing residual stress and working stress of the diamond microchannel were analyzed by finite element simulation. The wall thickness of the diamond microchannel was optimized. The minimum wall thickness, which was 0.4 mm, was obtained for the diamond microchannel with dimensions of 14 mm × 10 mm × 1.3 mm. On that basis, the influence of brazing pressure on the brazing filler overflow in the diamond microchannel brazing process was studied. It was showed that when the pressure was below 1 bar, the overflow of brazing filler from the brazing seam could be controlled to a minimum, especially suitable for brazing precision. The formation of residues in the diamond microchannel was thereby avoided basically, and a diamond microchannel heat sink with good performance was obtained.
Anti-turnover of Iced Transmission Lines Based on the Cable
Authors: Liu Zhuli , Hu Juntao , Wu Chuan , Zhang Bo 
Published: June 2023

Abstract
During the operation and maintenance of the transmission line, the phenomenon of turnover and twist was observed, which seriously affected the safety of the line operation. In this paper, considering that the turnover of the transmission line comes from the torsional galloping, a scheme is designed to restrain the turnover by connecting the conductor and the earth with cable. The torsional galloping angle of the line under the action of ice wind is proposed as a characteristic parameter to evaluate the prevention effect. Based on the finite element method, the torsional galloping of an iced line with equal height quad-bundle 450 m span under the condition of 50° wind attack angle and 12 m/s wind speed is analyzed, which verifies the feasibility of the cable turnover prevention scheme. The research studies the influence of cable load and hanging point position on the turnover prevention effect. The results show that the anti-turnover scheme of cable can effectively restrain the torsional galloping of the transmission line. Increasing the cable load will significantly reduce the torsional galloping degree of the transmission line. The effect of the cable on the torsional galloping of the transmission line near both sides of the hanging point position is more obvious.
Train craters to reduce the air resistance of trains during travel
Authors: Ma Zikai 
Published: June 2023

Abstract
First, we found various ways to reduce the air resistance to the train by studying some papers in the past years, and we selected the circular hole as the main subject of our study. After that, we used computational fluid dynamics to determine the main source of drag on the prototype, explore why the circular pit can reduce drag, and analyze how to make the circular pit have the best drag reduction effect. Finally, we selected the shape, spacing, and size of the circular pit. We clarified why our selected circular pit has the best drag reduction effect by the mechanism of the circular pit. It is clear that a 20 mm diameter 40 mm pit has the best effect, which can reduce about 2.79% of the resistance.
Mechanical Properties of Stretching-Bending Synergistic Lattice Materials
Authors: Liu Hui , Yang Zhongliang , Long Lianchun 
Published: June 2023

Abstract
Lattice materials are widely used in engineering structures as their potential for multifunctional applications. In this study, a body-centered cubic (BCC) stretching-bending synergistic lattice material is constructed based on the face-centered cubic with vertical struts (FCCZ) stretching configuration that has both stretching and bending deformation mechanisms. Finite element models and equivalent models are established to investigate the mechanical properties of the stretching-bending synergistic lattice material. The effect of the relative density of the frame unit cell is studied. The results show that the finite element model agrees well with the calculated results of the equivalent model. The stiffness of the stretching-bending synergistic lattice material is significantly increased with the increase of the relative density of the frame unit cell. The findings of this work provide a reference for predicting and optimizing the mechanical properties of the stretching-bending synergistic lattice materials.
The influence of detonation interval on the dynamic response of underground fortification
Authors: Yuan Jianfei , Feng Chun , Lin Qindong , Jiao Wenjun , Gan Yundan 
Published: June 2023

Abstract
It is of great theoretical significance and engineering application to investigate the influence of detonation interval on the dynamic response of underground fortification under blasting loading. First, a numerical simulation of underground fortification under blast loading is carried out based on the continuum-discontinuum element method. Then, the displacement characteristic of underground fortification is analyzed. Finally, the fracture characteristic of underground fortification is analyzed. The results indicate that the increasing trend of displacement at the top boundary gradually decays with the increase of detonation interval. The final value of displacement at the left boundary first increases and then decreases with the increase of detonation interval. With the increase in detonation interval, the proportion of concrete undergoing shear fracture at the top, left, and right boundary gradually decreases.
Energy Absorption Characteristics of Triply Periodic Minimal Surface Lattices
Authors: Wang Haodong , Li Siqi , Wang Cunxian 
Published: June 2023

Abstract
Historically, structural equipment has been studied to determine the impact and protection of its components, and common energy-absorbing materials include honeycomb, foam, bellows, and expansion tubes. According to related analyses, topological metamaterial structures designed based on mathematically known non-self-intersecting three-periodic minimal surfaces (TPMS) may possess superior mechanical properties. It is demonstrated in this study that a solid structure with a TPMS of 10 mm × 10 mm × 10 mm is constructed based on the Schwarz Primitive surface. Analyses were conducted on the effects of element type and modeling conditions on simulation results. Based on the simulation results, the solid element exhibited better analysis accuracy than the shell element. The structure had a better energy absorption capability when its surface thickness was set at approximately 1.31 mm.
The Fatigue topology optimization of orthotropic materials
Authors: Ye Hongling , Zhang Yiwen , Wei Nan , Wang Weiwei , Xiao Yang 
Published: June 2023

Abstract
Combining with the constitutive relation of orthotropic materials, a fatigue topology optimization model considering orthotropic materials is established based on the Independent Continuous Mapping (ICM) method. It uses the minimum structural mass as the optimization objective, the element fatigue life as the constraint condition, and the criterion method. The fatigue life filtration function, mass filtration function, and stiffness filtration function are introduced to identify whether the material is retained. The effectuality of the method is verified by several numerical examples, and the influence of different filter function coefficients on the results is explored. This paper has some theoretical significance for considering the fatigue properties of orthotropic material components in the conceptual design stage.
Experimental study on hysteretic properties of oscillating column structures
Authors: Zhao Bingzhen , Zhang Xiaomeng , Chen Jia , Feng Yao 
Published: June 2023

Abstract
This research aims at the problem of excessive temperature stress in the super-long structural system. In order to release the temperature stress and bending moment, a new type of oscillating column structure is proposed. Rubber pads are set up above and below the column to reduce the transmission of bending moment and make the column suffer more shear and axial force. The mechanical properties and mechanism were studied by seismic test. The experimental structure shows that this system has good deformation and mechanical properties compared with ordinary column structure and can be effectively applied to practical engineering.
Seismic performance of fabricated reinforced concrete bridge piers based on durable grouting material
Authors: Zhang Encheng , Yan Xianliang , Song Linlin , Cui Fengkun , Wang Risheng 
Published: June 2023

Abstract
To meet the high durable requirements of assembled bridge piers in the marine environment, a new grout is used in the grout sleeve to improve the corrosion resistance of the pier bottom. The seismic performance of piers adopting this new grout is studied. Firstly, a dynamic analysis model of the assembled reinforced concrete bridge pier with this grout is established using the finite element software ABAQUS. Moreover, the damage modes, hysteresis curves, and energy consumption for low reversal cyclic loading are investigated. The results indicate that the seismic failure mode of the precast piers is the concrete damage at the joints of the precast members, and the local damage of the grout in the grout sleeve does not affect the integral seismic performance of the bridge pier.
Plasma fluorination modified CaTiO3 for dielectric properties of PTFE-based composites
Authors: Zheng Xiaolei , Wang Qun 
Published: June 2023

Abstract
The interface incompatibility between organic polymer and inorganic ceramic filler is a common phenomenon in polymer-based dielectric composites. In this paper, the Ar/CF4 plasma is used to modify the CaTiO3 particles, which improved the dispersion of CaTiO3 and its compatibility with polytetrafluoroethylene (PTFE). The findings demonstrate that growing argon (Ar) flow rate was beneficial to enhance discharge and increase fluorinated graft content. The modified CaTiO3/PTFE is uniformly distributed and has no serious agglomeration phenomenon, which effectively improves its dielectric characteristics. Modified CaTiO3/PTFE composite with 5 wt.% CaTiO3 has a dielectric constant of 2.32 whilst the dielectric loss reaches 2.8 × 10−3 at around 10 GHz.
Searching for phase transitions in neutron stars with modified Gaussian processes
Authors: Mroczek Debora , Coleman Miller M. , Noronha-Hostler Jacquelyn , Yunes Nicolas 
Published: June 2023

Abstract
Gaussian processes provide a promising framework by which to extrapolate the equation of state (EoS) of cold, catalyzed matter beyond 1 – 2 times nuclear saturation density. Here we discuss how to extend Gaussian processes to include nontrivial features in the speed of sound, such as bumps, kinks, and plateaus, which are predicted by nuclear models with exotic degrees of freedom. Using a fully Bayesian analysis incorporating measurements from X-ray sources, gravitational wave observations, and perturbative QCD results, we show that these features are compatible with current constraints and report on how the features affect the EoS posteriors.
Constraints on the Nuclear Symmetry Energy from Experiments, Theory and Observations
Authors: Lattimer James M. 
Published: June 2023

Abstract
Nuclear mass measurements and neutron matter theory tightly constrain the nuclear symmetry energy parameters J, L, Ksym
and Qsym
. Corroboration of these constraints on J and L can be found from measurements of the neutron skin thicknesses and dipole polarizabilities of neutron-rich nuclei. The experimental constraints on these parameters are compared with those obtained from consideration of astrophysical measurements of the neutron star radius, which we show is highly correlated with L. Attention is aimed at the recent PREX and CREX neutron skin measurements from Jefferson Lab, NICER neutron star radius measurements, and a new interpretation of the GW170817 tidal deformability measurement. We find joint satisfaction of PREX and CREX gives J = 32.2 ± 1.7 MeV and L = 52.9 ± 13.2 MeV, in excellent agreement with neutron matter predictions of J = 32.0±1.1 MeV and L = 51.9±7.9 MeV.
Chiral Transport Phenomena and Compact Stars
Authors: Manuel Cristina 
Published: June 2023

Abstract
I will review the main chiral transport phemomena arising in systems made up of (almost) massless fermions associated to the quantum chiral anomaly. These quantum effects might have relevant implications in compact stars, and I will review some relevant works that reveal so. I will also show how a conservation law that has the same form of the chiral anomaly also emerge in perfect classical fluids, which expresses a conservation law of magnetic, fluid and mixed helicities for isentropic fluids, and why this should also be relevant in compact stars.
Superconducting detector magnets for high energy physics
Authors: Mentink M. , Sasaki K. , Cure B. , Deelen N. , Dudarev A. , Abe M. , Iio M. , Makida Y. , Okamura T. , Ogitsu T. , Sumi N. , Yamamoto A. , Yoshida M. , Iinuma H. 
Published: June 2023

Abstract
Various superconducting detector solenoids for particle
physics have been developed in the world. The key technology is the
aluminum-stabilized superconductor for almost all the detector
magnets in particle physics experiments. The coil fabrication
technology is also important and it has advanced along with the
conductor technology, such as the inner coil winding technique,
indirect cooling, transparent vacuum vessel, quench protection
scheme using pure aluminum strips and so on. The detector solenoids
design study is in progress for future big projects in Japan and
Europe, that is, ILC (International Linear Collider), FCC (Future
Circular Collider) and CLIC (Compact LInear Collider), based on the
technologies established over many years. The combination of good
mechanical properties and keeping a high RRR is a key point for the
development of Al-stabilized conductor. The present concern for the
detector solenoid development is to have been nearly losing the key
technologies and experiences. Nowadays, there are no industrial
companies having the capacity to manufacture such aluminum
stabilized superconductor. Complementary efforts are seriously
required to re-realize and validate the performance required in the
future projects in collaboration with worldwide institutes and
industries. Some mid-scale physics experiments required detector
solenoids wound with not aluminum stabilized conductor but
conventional copper stabilized conductor. The specific requirement
is to control the magnetic field distribution precisely, and the
efforts to realize the requirement are on going with regard to the
magnetic field design technology with high precision simulation,
coil fabrication technology and so on.
Intercropping red chili with leguminous crops to improve crop diversity and farmers’ resilience to climate change effects in dryland
Authors: Jaya I K D , Santoso B B , Jayaputra  
Published: June 2023

Abstract
This study aimed to explore the potential benefits of intercropping and determine the best time to sow leguminous crops between the rows of red chili or chili crops. Two leguminous crops, mungbean, and peanut were intercropped with chili in a dryland area of Gumantar, North Lombok, Indonesia. The leguminous seeds were sown five times; at the same time, a week, two weeks, three weeks, and four weeks after transplanting the chili seedlings. The treatments were arranged in a randomized block design with three replications. The size of each treatment plot was 600 × 100 cm, and the chili crops’ spacing was 60 × 60 cm. Three rows of leguminous crops were sown between the rows of chili crops with a spacing of 20 × 20 cm. Monocropping of chili, mungbean, and peanut was also provided in each block to calculate the land equivalent ratio (LER). The results showed that all the intercropping treatments had a LER value of higher than 1.0, indicating the advantage of intercropping over monocropping in terms of land utilization.
Crepidium ridleyi (J.J.Sm.) Szlach., a threatened endemic terrestrial orchid of Java: A Maxent modeling to predict the current and future potential distribution
Authors: Usmadi D , Wati R K , Cahyaningsih R , Purnomo D W 
Published: June 2023

Abstract

Crepidium ridleyi (J.J.Sm.) Szlach. is one of the endemic terrestrial orchids from Java. Due to rapid development and habitat fragmentation, it faces a severe threat of extinction. In this study, we predict the specific habitat of C. ridleyi within Java Island using the future greenhouse gas emission scenarios of RCP 4.5 and RCP 8.5 for the years 2050 and 2070. The occurrences were found in protected sites but have yet to be conserved in ex-situ sites. The current and future of this species distribution model comparison showed that habitat suitability is declining, even projecting the extinction in the worst scenario in the far future. Thus, supporting active conservation efforts for this species is strongly advised to protect it from extinction and use it sustainably.