bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pressure dynamics of an internal shock wave emission inside a water droplet and potential cavitation
Authors: Tang Mao , Zhang Hongchao , Lu Jian 
Published: December 2023

Abstract
Shock reflected by a spherical interface is involved in shock-droplet interaction. Here, we investigate the pressure dynamics of an internal spherical shock wave and the potential cavitation inside a spherical water droplet. We conduct hydrodynamic simulation and employ the linear geometrical acoustics approximation to analyze the negative pressure and the wavefront at different intervals d between the source point of the shock and the droplet surface. Studies indicate that the negative pressure at a very large d is primarily attributed to the focusing effect of the droplet surface, whereas the collision of the reflected waves contributes to negative pressure at a small d. The caustic, which is the locus of the cusps (singular points) on the shock wavefront is determined by the parametric equations. Notably, the caustic also has singular points owing to the off-axis reflection. Finally, we evaluate the cavitation inside the droplet. Cavitation occurs on the opposite side of the droplet and moves away from the surface with d increasing, which agrees with previous experimental results. Additionally, we demonstrate that cavitation can occur with less damage to the droplet compared to a planar shock impact on a water droplet.
Nonlinear electrostatic kelvin-helmholtz shock waves in a viscous electron-positron-ion plasma with non-maxwellian distribution
Authors: Ahmad Mushtaq , Ahmad Zulfiqar , Farooq M , Usman S 
Published: December 2023

Abstract
A theoretical investigation is carried out for nonlinear electrostatic Kelvin-Helmholtz (K-H) shock waves in a magnetized electron-positron-ion viscous plasma in the presence of transport equations and non-Maxwellian particles by following the generalized (r, q) distribution function. The propagation of electrostatic K-H modes are studied both in the presence of trapped and free electrons. The nonlinear analysis with inclusion of plasma transport properties (magnetic viscosity and heat conduction) lead to nonlinear electrostatic K-H mode in the form of shock like waves by solving the modified Burgers’ equation. The electrostatic K-H shocks are investigated numerically with effect of different plasma parameters such as shear velocity and non-Maxwellian distributed particles. It is observed that the striking features (viz., amplitude and width of dissipative shock through the solution of Burgers’ equation) of the K-H mode are significantly modified by the effects of non-thermality of electrons and positrons both at shoulder and tails along with shear velocity due to viscosity. The relevancy of our work to the observations in space (viz., cometary comae and earth’s ionosphere), astrophysical (viz., pulsars) and laboratory (viz., solid-high intense laser plasma interaction experiments) plasmas is highlighted.
Diffuse reflectance and photoluminescence spectroscopic investigations of Sr2RE8(SiO4)6O2 (RE = rare earth) apatites
Authors: Viegas Jéssica I , Martins Guilherme M , Dias Anderson 
Published: December 2023

Abstract
Apatite-type compounds have attracted attention due to their flexible crystalline structure besides high chemical stability, which increases the interest in understanding and modifying their properties to achieve the requirements for applications in catalysis and energy devices. In order to attend these demands, this paper investigates the optical properties of apatite-type Sr2
RE
8(SiO4)6O2 ceramics (RE = rare earth) by using diffuse reflectance and photoluminescence spectroscopies. Intraconfigurational f-f transitions, charge transfer bands, and energy gaps were identified and detailed discussed in terms of their relationships with the structural features of the rare earth apatites. Although all materials have the same hexagonal space group (P6
3
/m, # 176), the band gaps varied between 3.51 and 3.95 eV, for Eu- and Yb-containing apatites, respectively, showing the influence of their ionic radii and their electronic configurations on this property. In this sense, diffuse reflectance spectroscopy emerges as a powerful tool to study the optical properties of rare earth-containing materials as a complementary technique to photoluminescence spectroscopy. In this work, these techniques were discussed in association, which allowed us to provide a complete set of optical information that improves the understanding of apatite-type materials, as required in advanced technological demands.
Millimeter-wave metalens with extended depth of focal on the short focal length
Authors: Zhang Quansheng , Guo Di , Shen Changsheng , Chen Zhaofu , Bai Ningfeng 
Published: December 2023

Abstract
Millimeter wave (mm-wave) metalens has shown significant progress in recent years. However, the existing works in the literature on the extended depth of focal (EDOF) metalens present limitations for mm-waves. More specifically, the good performance of the EDOF requires a focal length larger than the radius of the metalens, which limits its miniaturization applications. In this work, mm-wave metalens with EDOF on the short focal length was proposed. The focus distribution was equally divided and the spin Hall effect was employed to guarantee the uniform focus intensity. From our analysis, it was demonstrated that the designed metalens can work at mm-wave frequencies and also achieve extended focal depth at half the metalens’ radius. The proposed metalens has the unique characteristics of short focal length (The focal diameter ratio is 0.36) with EDOF. Moreover, it can be used in the mm-wave field for short-distance imaging and detection, also the development of high-power metalens applications may be facilitated.
A Sine-coupled model for constructing N-dimensional non-degenerate discrete hyperchaotic map
Authors: Huang Lilian , Li Chuang , Yang Yan , Mao Yanhao 
Published: December 2023

Abstract
The non-degenerate hyperchaotic systems with the maximum number of positive Lyapunov exponents (LEs) typically have better ergodicity, pseudo randomness, and stronger anti-degeneration property. Therefore, designing non-degenerate hyperchaotic maps with complex dynamics has attracted increasing attention from various research fields in recent years. By introducing the sine function, this paper proposes a construction model of N-dimensional non-degenerate discrete hyperchaotic map. To verify the effectiveness of this model, we provide three sub-maps of different dimensions based on this model as illustrative examples, and the dynamic behavior is explored using multiple numerical measures. The results demonstrate that the sub-maps with concise symmetric structures have complex dynamics, such as ultra-wide non-degenerate hyperchaotic parameter range, state transition phenomenon, and multistability. In particular, coexisting symmetric attractors and quasi-periodic curves switch periodically with the change of initial value. Furthermore, the hyperchaotic sequences generated by the three sub-maps have excellent performance, and the NIST test also further verifies the super randomness and unpredictability of these sequences. Finally, through the DSP hardware platform, the physical realizability of the sub-maps is verified successfully.
The enhanced adsorption mechanism of ethanol on (Fe-Zn) bimetallic-doped Ti2CO2 monolayers: a DFT study
Authors: Zhao Bing , Liu Xin , Zhang Hanmei , Su JiaHui , Feng Yue , Shen Tao 
Published: December 2023

Abstract
Ti2C as a new two-dimensional layered MXene material has a certain potential in the sensor field. The adsorption properties of gases (NH3, NO, ethanol, CO) on intrinsic Ti2CO2 and transition metal atoms (Fe, Zn) doped Ti2CO2 were studied by density functional theory systematically. The geometric structure, adsorption energy, molecular dynamics, energy band structure, density of states, charge transfer, and differential charge density of these molecules at five sites of intrinsic Ti2CO2, Fe-doped Ti2CO2, Zn-doped Ti2CO2, FeZn-adjacent co-doped Ti2CO2 and FeZn-pair co-doped Ti2CO2 were analyzed. The results show that the activity of the substrate can be improved by the introduction of Fe-Zn transition metals. The high adsorption energy of ethanol gas at (A) FeZn site is −1.98eV with the short adsorption distance. The high charge transfer between the metal co-doped Ti2CO2 substrate and ethanol gas was also found. The results suggest that the Fe-Zn bimetallic-doped Ti2CO2 monolayer may be a potential sensing material for the detection of ethanol gas.
The linear response theory approach to the sub-GeV dark matter in the Sun
Authors: Liang Zheng-Liang , Zhang Ping 
Published: December 2023

Abstract
In recent years, the importance of the electronic in-medium effect
in the sub-GeV dark matter (DM) direct detection has been recognized
and a coherent formulation of the DM-electron scattering based on
the linear response theory has been well established in the literature.
In this paper, we apply the formulation to the scattering between
DM particles and solar medium, and it is found that the dynamic structure
factor inherently incorporate the particle-particle scattering and
in-medium effect. Using this tool and taking a benchmark model as
an example, we demonstrate how the in-medium effect affects the scattering
of DM particles in the Sun, in both the heavy and the light mediator
limit. Formulae derived in this work lay the foundation for accurately
calculating the spectra of solar-accelerated DM particles, which is
of particular importance for the detection of DM particles via plasmon
in semiconductor targets.
General parallel cosmology
Authors: Aguiar Gomes Débora , Beltrán Jiménez Jose , Koivisto Tomi S. 
Published: December 2023

AbstractGeneral (tele)parallel Relativity, G∥R, is the relativistic completion of Einstein's theories of gravity. The focus of this article is the derivation of the homogeneous and isotropic solution in G∥R. The first-principles derivation, based on a non-trivial realisation of the symmetry, supersedes and unifies previous constructions of Riemannian and teleparallel cosmologies, and establishes the uniqueness of the physical solution. The constitutive law and the form of the material and inertial source currents is presented in the tensor (Palatini) formalism and adapted to the cosmological background, which exhibits novel features absent in the previously studied, static solutions to the theory. The results are contrasted with those in incomplete theories, such as sitting at the three corners of the geometrical trinity which correspond to particular reference frames in G∥R.
A thermodynamical model of non-deterministic computation in cortical neural networks
Authors: Stoll Elizabeth A 
Published: December 2023

Abstract
Neuronal populations in the cerebral cortex engage in probabilistic coding, effectively encoding the state of the surrounding environment with high accuracy and extraordinary energy efficiency. A new approach models the inherently probabilistic nature of cortical neuron signaling outcomes as a thermodynamic process of non-deterministic computation. A mean field approach is used, with the trial Hamiltonian maximizing available free energy and minimizing the net quantity of entropy, compared with a reference Hamiltonian. Thermodynamic quantities are always conserved during the computation; free energy must be expended to produce information, and free energy is released during information compression, as correlations are identified between the encoding system and its surrounding environment. Due to the relationship between the Gibbs free energy equation and the Nernst equation, any increase in free energy is paired with a local decrease in membrane potential. As a result, this process of thermodynamic computation adjusts the likelihood of each neuron firing an action potential. This model shows that non-deterministic signaling outcomes can be achieved by noisy cortical neurons, through an energy-efficient computational process that involves optimally redistributing a Hamiltonian over some time evolution. Calculations demonstrate that the energy efficiency of the human brain is consistent with this model of non-deterministic computation, with net entropy production far too low to retain the assumptions of a classical system.
Free Energy of Anisotropic Strangeon Stars
Authors: Chen Shichuan , Gao Yong , Zhou Enping , Xu Renxin 
Published: December 2023

Abstract
Can pulsar-like compact objects release further huge free energy besides the kinematic energy of rotation? This is actually relevant to the equation of state of cold supra-nuclear matter, which is still under hot debate. Enormous energy is surely needed to understand various observations, such as γ-ray bursts, fast radio bursts and soft γ-ray repeaters. In this paper, the elastic/gravitational free energy of solid strangeon stars is revisited for strangeon stars, with two anisotropic models to calculate in general relativity. It is found that huge free energy (>1046 erg) could be released via starquakes, given an extremely small anisotropy ((p
t − p
r)/p
r ∼ 10−4, with p
t/p
r the tangential/radial pressure), implying that pulsar-like stars could have great potential of free energy release without extremely strong magnetic fields in the solid strangeon star model.
Evaluating and benchmarking the EEG signal quality of high-density, dry MXene-based electrode arrays against gelled Ag/AgCl electrodes
Authors: Erickson Brian , Rich Ryan , Shankar Sneha , Kim Brian , Driscoll Nicolette , Mentzelopoulos Georgios , Fernandez-Nuñez Guadalupe , Vitale Flavia , Medaglia John D 
Published: December 2023

Abstract

Objective. To evaluate the signal quality of dry MXene-based electrode arrays (also termed ‘MXtrodes’) for electroencephalographic (EEG) recordings where gelled Ag/AgCl electrodes are a standard. Approach. We placed 4 × 4 MXtrode arrays and gelled Ag/AgCl electrodes on different scalp locations. The scalp was cleaned with alcohol and rewetted with saline before application. We recorded from both electrode types simultaneously while participants performed a vigilance task. Main results. The root mean squared amplitude of MXtrodes was slightly higher than that of Ag/AgCl electrodes (.24–1.94 uV). Most MXtrode pairs had slightly lower broadband spectral coherence (.05 to .1 dB) and Delta- and Theta-band timeseries correlation (.05 to .1 units) compared to the Ag/AgCl pair (p < .001). However, the magnitude of correlation and coherence was high across both electrode types. Beta-band timeseries correlation and spectral coherence were higher between neighboring MXtrodes in the array (.81 to .84 units) than between any other pair (.70 to .75 units). This result suggests the close spacing of the nearest MXtrodes (3 mm) more densely sampled high spatial-frequency topographies. Event-related potentials were more similar between MXtrodes (ρ ⩾ .95) than equally spaced Ag/AgCl electrodes (ρ ⩽ .77, p < .001). Dry MXtrode impedance (x̄ = 5.15 KΩ cm2) was higher and more variable than gelled Ag/AgCl electrodes (x̄ = 1.21 KΩ cm2, p < .001). EEG was also recorded on the scalp across diverse hair types. Significance. Dry MXene-based electrodes record EEG at a quality comparable to conventional gelled Ag/AgCl while requiring minimal scalp preparation and no gel. MXtrodes can record independent signals at a spatial density four times higher than conventional electrodes, including through hair, thus opening novel opportunities for research and clinical applications that could benefit from dry and higher-density configurations.
Economically optimized design point of high-field stellarator power-plant
Authors: Prost Victor , Volpe Francesco A. 
Published: December 2023

Abstract
High temperature superconductors (HTSs) expand the design space of stellarator power-plants (PPs) toward high magnetic fields B, enabling compact major radii R. The present paper scans the space of B, R and other design parameters, finding solutions that are promising from a physics and engineering standpoint, while minimizing the capital cost of the PP and the levelized cost of fusion electricity. Similarly, it identifies minimum-cost design points for next-step burning plasma stellarator experiments of fusion gain

1
<
Q
<
10

. The study assumes advanced stellarator configurations of reduced aspect ratio, heated by neutral beam injection. Plasma-facing, flowing liquid metal (LM) walls protect it from high heat and neutron fluxes. The study relies on analytical first-principle calculations, and established zero-dimensional (0D) empirical scaling laws. Power flows are illustrated by Sankey diagrams. Plasma operating contours are used to determine the reactor’s start-up path. Sensitivity analyses are conducted to identify the most critical reactor parameters within physics, engineering and costing, quantifying their influence on the economics of the PPs. Such 0D study suggests that the assumed next generation HTS, flowing LM walls, and advances in compact plasma configurations could lead to an ignited stellarator PP of aspect ratio

A
∼
4

,

R
⩽
4

m, B > 9 T, and normalized plasma pressure

β
∼
5
%

which would minimize both the cost of electricity and capital cost while achieving a net electric power of about 1 GW.
Anisotropy of field-controlled shear viscosity of dipolar fluids
Authors: D Fjeldstad Christopher , Pousaneh Faezeh , Troncoso Roberto E , de Wijn Astrid S 
Published: December 2023

Abstract
We numerically study the anisotropic viscous response of dipolar hard spheres in the presence of an electric field. We find that the shear viscosity is sensitive to both the strength and orientation of the field relative to the shearing direction. The effect on the viscosity is strongest when the field is oriented in the shear gradient direction. We investigate the structure of the fluid in detail to explain the mechanism for the changes in viscosity, and show that the reorientation of chain-like clusters plays a crucial role. We show that the anisotropy arises from the polarization of the fluid induced by the field, leading to the orientation of chain-like clusters along the direction of the field.
NIR reflective Paints as an Alternative for Sustainable Façade Renovation
Authors: Souza Andrea R. , Veloso Rita Carvalho , Maia Joana , Flores-Colen Inês , Ramos Nuno M. M. 
Published: December 2023

Abstract
Several studies of infrared reflective materials used on opaque envelopes have shown that their application can reduce the surface temperature and the cooling energy needs of buildings and help mitigate the urban heat island effect. Some of these studies were carried out by incorporating near-infrared (NIR) reflective materials on new buildings or as part of new construction systems, considering that one of the simpler and most used façade renovation methods is repainting. In a repainting process, the reflectance could change since the reflectance depends on the interaction between the reflective layer and the substrate. A study was carried out on the reflectance of paints with NIR reflective properties applied on the finishing coat of external thermal insulation composite systems (ETICS), simulating a façade renovation. A black NIR reflective paint was applied in one layer over the existing finishing coat of two ETICS samples: one with a grey mortar colour and another with a conventional black colour. A second configuration was considered by adding an intermediate layer of regularisation with white colour. Traditional black colour and the mortars were applied on a transparent acrylic base as a reference. The samples were assessed with a modular spectrophotometer to assess the total and NIR reflectance and the colour coordinates on the CIELab space. The results showed that the reflectance and colour of the new layer are independent of the colour or type of the first layer in the case of conventional paint. Conversely, the substrate affects the NIR paint performance, where a lighter substrate can help improve the reflectance but can also lead to a more significant colour change. Likewise, the results of the paint over a new white layer resulted in a lower reflectance compared to the reflectance of a single paint layer.
Assessing the deterioration risk of mural paintings in Cave 98 of Mogao Grottoes based on the hygrothermal behavior
Authors: Hu X Q , Zhang Z M , Zhang R B , Yang Z X , Hokoi S , Li Y H 
Published: December 2023

Abstract
Cave 98 is a typical cave in Mogao Grottos with various and serious degradations. This paper aims to clarify the heat and moisture transfer law of Cave 98 and murals and evaluate whether the current hygrothermal environment is conducive to the long-term preservation of murals. In this paper, a coupled heat and moisture transfer 2D model of Cave 98 was first established, and the accuracy of the model was verified by on-site monitoring data. Then, the spatial distributions of the temperature and moisture in Cave 98 were analyzed, and the quantitative evaluation of the deterioration risk of mural paintings in different locations was further evaluated. The results showed that 14% and 13.8% of the time indoor temperature and relative humidity (RH) exceeded the target range. Salt damage occurred more than 10 days a year, mold contamination occurred just a few days a year, and deterioration occurred at its peak in summer. Dehumidification measures can be taken during periods of high humidity to improve the adaptability of the current preservation environment.
Distribution and location of damages in Swedish buildings
Authors: Mundt-Petersen S O , Wallentén P , Joelsson A , Kläth M 
Published: December 2023

Abstract
Different damages and defects in buildings create huge cost for owners and the society. Besides free water damages, current knowledge about damages in buildings in general focuses on costs and has a qualitative approach rather than based on real quantitative facts. This paper presents the location and distribution of 1105 different damages, failures, and functional defects in Swedish buildings based on real damage investigations. Besides moisture inventories, most of the damage investigations were initiated by perceived SBS (Sick Building Syndrome) or visible free water. Possible negative effects on the indoor environment caused by different types of microbial growth were the most common damage. Damages often become noticed and, at a later state, located in ordinary rooms or classrooms. Most of the damages were located in the exterior wall and generally in wooden materials. The number of reported damages in the form of emissions from flooring due to degradation of glue was low in the studied sample.
Sensitivity Analysis of Traditional Solid Masonry Wall to Frost Damage in North China
Authors: Chen Xiaolin , Van De Bossche Nathan 
Published: December 2023

Abstract
The historic façades are significant to building heritage, but they are also extremely vulnerable to changing environmental conditions. Water is well studied as the primary agent that causes the deterioration of porous materials, but the impact of variations in moisture storage, moisture transport, and thermal properties of the materials in solid masonry wall construction remains uncertain and requires quantitative analysis. Sensitivity analysis of solid wall construction can be beneficial in understanding the correlation between material properties and risk in proposing rational preservation strategies. This paper aims to investigate the predominant parameters for frost damage criteria in traditional Chinese masonry construction in North China. Under typical outdoor climate conditions in North China and a constant indoor climate, a 2D Heat, Air Moisture (HAM) model is applied to 240mm and 370 mm thick walls. The sensitivity analysis is quantified with three frost-related criteria. The hygrothermal simulation validates that the main dominant factor varies with different criteria and that the properties of adjacent materials dominate the frost damage risk at certain locations. The results could contribute to the expansion of the international material database and the conservation of masonry heritage from the risk of the freeze-thaw cycle.