bluuebunny/crossref_metadata_2025_split huggingface dataset:
Numerical and experimental investigation of the steam penetration in narrow channels during a dynamic steam sterilization cycle
Authors: Pletzer Simon , Miranda Marco , Magno Marino , Hochenauer Christoph 
Published: September 2024

Abstract
The most challenging aspect of steam sterilization is the removal of all non-condensable gases (NCGs) from the autoclave. These gases prevent the effective killing of microorganisms, impairing the sterility of medical devices. Special cycles are performed to ensure the penetration of steam, even into the deepest passages. To better understand this process, numerical models were developed to determine the spatial distribution of steam within the chamber, including its penetration into narrow channels. These are the first models that can be used to accurately determine the flow within three-dimensional cavities during a dynamic sterilization cycle. To validate the model, an experiment was designed using direct tunable diode laser absorption spectroscopy at a wavelength of 1364 nm to measure the mole fraction of steam present at the end of an aluminum pipe at a temporal resolution of 1 s. This represents a pioneering application of this technique in the field of steam sterilization. This setup was designed for installation on any autoclave. Both simulation and experimental data exhibit good agreement over the entire pressure range (0.18–3.15 bar). The most interesting observation made during the study was the increase in the steam content at the end of the tube while a vacuum was generated. The numerical results show that the mole fraction of H2O increased from 0.53 to 0.63 over the course of a single vacuum phase. This phenomenon was attributed to a stronger diffusion effect combined with small pressure gradients during low pressures. This finding inspired the idea of taking the diffusion effect more into account when designing sterilization cycles in the future to make them more sustainable and effective. The presented methodologies and models represent an excellent basis for conducting more complex investigations in the future, such as those investigating the influence of condensation effects on steam penetration in cavities.
Efficient prediction of mechanical properties of Boron Nitride Nanosheets using artificial neural networks
Authors: Kumari Nisha , Sarangi Saroj Kumar 
Published: September 2024

Abstract
This paper aims to evaluate the mechanical properties of Boron Nitride Nanosheets (BNNS) and their vital use in nano-electromechanical systems (NEMS). By employing molecular Dynamics (MD) simulation, modelling of the atomic structure was done. The mechanical response of BNNS under various parameters (strain rate, temperature, chirality and dimension) enabled the generation of a comprehensive data set that accurately represents their elastic properties. The dataset obtained from MD simulation was subsequently utilized to construct an artificial neural network (ANN) model, tailored to predict the Young’s modulus of BNNS accurately. This work aimed to improve the model’s efficiency by refining the design of ANN, which significantly reduces the computational time while maintaining higher accuracy predictions. The findings demonstrate precise and rapid prediction for developing components based on BNNS in NEMS. This paper establishes an analogy between in-depth atomistic simulations and real-world engineering applications presenting a new approach for precisely predicting the attributes of nanomaterials.
A color image encryption algorithm based on a novel 4D hyperchaotic system and bit-level diffusion
Authors: Liu Tongzhe , Chen Zhong , Long Bofeng , Wu Ximei , Wang Lujie , He Chenchen , Cao Can 
Published: September 2024

Abstract
As digital images are widely used in social media, medical, military and other fields, ensuring the privacy and security of image data has become a critical concern. Firstly, we propose a novel four-dimensional hyperchaotic system and validate that it exhibits a broad chaotic range, as demonstrated by bifurcation diagrams and Lyapunov exponent experiments. Additionally, simulated circuit diagrams verify the hardware feasibility of the proposed system. Secondly, we design a dynamic iterative scrambling (DIS) scheme that dynamically divides the image into multiple matrices for spatially indexed scrambling. Excellent substitution performance can be ensured by multiple iterations. In the diffusion stage, a multidirectional bit-level L-shaped (MDBL) scheme is proposed. Diffusion is conducted on the bit plane using a designed cross-multiplanar selection algorithm, which fuses the high and low bit planes, thereby enhancing the diffusion performance of MDBL. Thirdly, Based on the above concepts, a novel four-dimensional hyperchaotic system and an encryption algorithm based on bit-level diffusion are proposed. Finally, experimental results and security analyses demonstrate the effectiveness of the novel 4D hyperchaotic system and image encryption scheme. The proposed encryption scheme exhibits robust anti-interference capabilities and effectively safeguards image security.
Superconductivity in LaO: a density functional theory study with local, semilocal, and nonlocal exchange-correlation functionals
Authors: Rehman Habeeb-ur- , Shahbaz Muhammad , Afaq A 
Published: September 2024

Abstract
We studied the dynamical, electronic, and superconducting properties of LaO using a local (PZ), a semilocal (PBE), and three nonlocal correlation functionals (rVV10, vdW-DF2, and vdW-DF3) of the density-functional theory. We concluded that the nonlocal correlations have a marginal effect on the electronic band energies near the Fermi surface. However, the corresponding shifts in the density of states are relatively significant. In contrast, the phonon energies get modified by larger amounts, particularly for optical phonons. These variations in energies of optical phonons do not get reflected to the same degree in electron-phonon coupling constant, λ, from different functionals as their contribution in λ is minor that ranges from 21% to 33%. Moreover, the imperative role of Kohn anomalies and Fermi surface nesting for the electron-phonon coupling is reconfirmed. We also highlighted the role of the matrix elements that surpasses, in certain parts of the Brillouin Zone, all other factors including the Fermi surface nesting. The nonlocal correlation functional, vdW-DF2, gives significantly different results than other nonlocal as well as local/semilocal functionals due to excessive low energy phonons and larger phonon linewidth.
Edge-state-mediated RKKY coupling in graphene nanoflakes
Authors: Canbolat Ahmet Utku , Çakır Özgür 
Published: September 2024

Abstract
We investigate the long-range behavior and size dependence of the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction in hexagonal and triangular graphene nanoflakes with zigzag and armchair edges. We employ the tight-binding model with exact diagonalization to calculate the RKKY interaction as a function of the distance between magnetic impurities, nanoflake size, and edge geometry. Our findings demonstrate a strong dependency of the RKKY interaction on edge geometry and flake size, with notable changes in the RKKY interaction strength. We further analyze the influence of structural defects on the interaction strength of exchange interactions.
Theoretical and experimental study of a two-dimensional circular stealth acoustic lens
Authors: Gong Feilong , Li Qi , Sun Xiaomei , Kong Yue , Liu Song 
Published: September 2024

Abstract
The detection of underwater acoustic signals is a key focus in ocean development, and acoustic metamaterials play a crucial role in achieving this goal. Pentamode metamaterials exhibit fluid-like properties, allowing for the propagation of compressional waves without shear waves. In this study, a two-dimensional circular stealth acoustic lens based on pentamode metamaterials was proposed. By applying the transformation acoustics theory, the theoretical properties of circular stealth acoustic lenses were calculated, and they were verified with Finite Element Method (FEM). A practical model was designed with pentamode metamaterials and silicone oil, and its performance was verified with FEM software. A half-model was fabricated, and underwater experiments demonstrate that it does not effectively affect the propagation state of acoustic waves. The consistency between theoretical results and experimental findings highlights practical significance and broad application prospects for the circular stealth acoustic lens in the field of acoustic detection.
Comparative analysis of thermoelectric properties in bulk 2H and monolayer MoS2: a first-principles study at high temperatures
Authors: Kumar Rohit , Muralidharan Bhaskaran 
Published: September 2024

Abstract
The pursuit of high-efficiency heat-to-electricity conversion is one of the indispensable driving forces toward future renewable energy production. The two-dimensional (2D) transition metal dichalcogenide, such as molybdenum disulfide (MoS2), is at the forefront of research due to its outstanding heat propagation features and potential applications as a thermoelectric material. Using the first-principles density functional theory coupled with the semi-classical Boltzmann transport equation within the constant relaxation time approximation, we present the thermoelectric and energy transport in the bulk 2H and monolayer MoS2 material system. In order to advance the underlying physics, we calculate several crucial transport parameters such as electrical conductivity, electronic thermal conductivity, Seebeck coefficient, and power factor as a function of the reduced chemical potential for different doping types and temperatures, in addition to the electron energy dispersion relation of the material system. Our comprehensive study employs the Shankland interpolation algorithm and the rigid band approximation to attain a high degree of accuracy. This thorough investigation reveals the high Seebeck coefficient of 1534 and 1550 μ
V/K at 500 K for the bulk 2H and monolayer MoS2, respectively. Furthermore, the ultrahigh power factor values of 9.21 × 1011 and 3.69 × 1011
Wm
−1
K
−2
s
−1 are shown at 800 K in the bulk 2H and monolayer MoS2, respectively. Based on the power factor results, our in-depth analysis demonstrates that the bulk 2H MoS2, when compared to monolayer MoS2, exhibits great potential as a promising semiconducting thermoelectric material for advanced high-performance energy device applications.
Role of biquadratic exchange on thermodynamic quantities in anisotropic Heisenberg model
Authors: Korkmaz Nida , Mert Gülistan 
Published: September 2024

Abstract
The magnetic and thermodynamic properties of the spin-1 anisotropic Heisenberg system are studied within Oguchi approximation. The system contains both the bilinear and biquadratic exchange interactions between the nearest neighboring spins located on a centered honeycomb lattice. For the positive biquadratic exchange interaction parameters, the phase transition in the Heisenberg case is of both second and first order where there is a discontinuity in the thermodynamic properties at this transition temperature. For some negative biquadratic exchange interaction parameters, in both the Heisenberg and Ising cases, the ferromagnetic state changes in favor of the antiferromagnetic state. The frustrated antiferromagnetic structure created by the biquadratic exchange parameter with negative sign was shown significantly influence the magnetization, quadrupolar moment, internal energy, heat capacity, entropy and free energy of the system, where the system has an oscillating chaotic phase regime. A double peak behavior was observed in the specific heat, with one at the critical temperature and another at a low temperature.
Cosmography of the local Universe by multipole analysis of the expansion rate fluctuation field
Authors: Kalbouneh Basheer , Marinoni Christian , Maartens Roy 
Published: September 2024

Abstract
We establish a relationship between the multipoles of the expansion rate fluctuation field η, which capture in an accurate way deviations from isotropy in the redshift-distance relation, and the multipoles of the covariant cosmographic parameters—Hubble ℍ
o
, deceleration ℚ
o
, jerk 𝕁
o
, and curvature ℝ
o
. These parameters, derived from the third-order expansion of the luminosity distance with respect to redshift in a generic spacetime, provide model-independent insight into the geometry and symmetries of the cosmic line element without requiring the Cosmological Principle. Moreover, we demonstrate that although this approach is fully nonperturbative and does not rely on concepts such as peculiar velocities, it has the potential to constrain the motion of the matter frame at the observer's position relative to the cosmic microwave background.

We use two analytical axisymmetric models, motivated by observational evidence, to test the formalism and the effectiveness of the third-order expansion of the luminosity distance. These models also help to predict the precision with which future surveys, like the Zwicky Transient Facility, will constrain the covariant cosmographic parameters in the local (z < 0.1) Universe.
Covariant cosmography: the observer-dependence of the Hubble parameter
Authors: Maartens Roy , Santiago Jessica , Clarkson Chris , Kalbouneh Basheer , Marinoni Christian 
Published: September 2024

AbstractThe disagreement between low- and high-redshift measurements of the Hubble parameter is emerging as a serious challenge to the standard model of cosmology. We develop a covariant cosmographic analysis of the Hubble parameter in a general spacetime, which is fully model-independent and can thus be used as part of a robust assessment of the tension. Here our focus is not on the tension but on understanding the relation between the physical expansion rate and its measurement by observers — which is critical for model-independent measurements and tests. We define the physical Hubble parameter and its multipoles in a general spacetime and derive for the first time the covariant boost transformation of the multipoles measured by a heliocentric observer. The analysis is extended to the covariant deceleration parameter. Current cosmographic measurements of the expansion anisotropy contain discrepancies and disagreements, some of which may arise because the correct transformations for a moving observer are not applied. A heliocentric observer will detect a dipole, generated not only by a Doppler effect, but also by an aberration effect due to shear. In principle, the observer can measure both the intrinsic shear anisotropy and the velocity of the observer relative to the matter — without any knowledge of peculiar velocities, which are gauge dependent and do not arise in a covariant approach. The practical implementation of these results is investigated in a follow-up paper. We further show that the standard cosmographic relation between the Hubble parameter, the redshift and the luminosity distance (or magnitude) isnotinvariant under boosts and holds only in the matter frame. A moving observer who applies the standard cosmographic relation should correct the luminosity distance by a redshift factor — otherwise an incorrect dipole and a spurious octupole are predicted.
Numerical challenges in modeling gravothermal collapse in Self-Interacting Dark Matter halos
Authors: Palubski Igor , Slone Oren , Kaplinghat Manoj , Lisanti Mariangela , Jiang Fangzhou 
Published: September 2024

Abstract
When dark matter has a large cross section for self scattering, halos can undergo a process known as gravothermal core collapse, where the inner core rapidly increases in density and temperature.
To date, several methods have been used to implement Self-Interacting Dark Matter (SIDM) in N-body codes, but there has been no systematic study of these different methods or their accuracy in the core-collapse phase. In this paper, we compare three different numerical implementations of SIDM, including the standard methods from the GIZMO and Arepo codes, by simulating idealized dwarf halos undergoing significant dark matter self interactions (σ/m = 50 cm2/g).
When simulating these halos, we also vary the mass
resolution, time-stepping criteria, and gravitational force-softening scheme. The various SIDM methods lead to distinct differences in a halo's evolution during the core-collapse phase, as each results in spurious scattering rate differences and energy gains/losses.
The use of adaptive force softening for gravity can lead to numerical heating that artificially accelerates core collapse, while an insufficiently small simulation time step can cause core evolution to stall or completely reverse. Additionally, particle numbers must be large enough to ensure that the simulated halos are not sensitive to noise in the initial conditions. Even for the highest-resolution simulations tested in this study (106 particles per halo), we find that variations of order 10% in collapse time are still present.
The results of this work underscore the sensitivity of SIDM modeling on the choice of numerical implementation and motivate a careful study of how these results generalize to halos in a cosmological context.
Differences in the acoustic characteristics of DC bias alternating arcs in argon, helium, and nitrogen
Authors: Li 李 Yutai 雨泰 , Wen 文 Qinghao 清皓 , Fu 付 Yangyang 洋洋 , Zou 邹 Xiaobing 晓兵 , Li 黎 Handong 晗东 , Liu 刘 Zhigang 志刚 , Luo 罗 Haiyun 海云 , Qian 钱 Dun 盾 , Chen 陈 Zhe 喆 , Wang 王 Xinxin 新新 
Published: September 2024

Abstract
The acoustic effects of gas discharge plasma have received much attention. Previous studies have shown that cold plasma and thermal plasma have different principles of sound generation. In this paper, the differences in the acoustic characteristics of DC bias alternating arc plasma (thermal plasma) in different gas environments (argon, helium, and nitrogen) are investigated by combining experiments and simulations. Many processes in industrial machining involve this arc plasma. It was found that the acoustic characteristics of the arcs of these three gases are significantly different. The two key parameters, electrical and thermal conductivity of the gas, determine the acoustic characteristics of the arc by influencing the electric power of the arc and the heat dissipation through the anode. At the same drive current, the nitrogen arc has the largest voltage drop and the helium arc has the highest electroacoustic conversion efficiency. This results in the acoustic pressure amplitude being helium, nitrogen, and argon in descending order. The research contributes to a deeper understanding of the vocalization mechanism of arc plasma and provides theoretical guidance on gas selection for arc acoustic wave applications.
Screening A-site ordered quadruple perovskites for alkaline hydrogen evolution reaction via unifying electronic configuration descriptor
Authors: Sun 孙 Ning 宁 , Li 李 Wenbo 文博 , Qin 秦 Yang 杨 , Zheng 郑 Zhichuan 智钏 , Zhang 张 Bowen 博文 , Dong 董 Xiangjiang 祥江 , Wei 魏 Peng 鹏 , Zhang 张 Yixiao 艺潇 , He 何 Xian 贤 , Xie 谢 Xinyu 新煜 , Huang 黄 Kai 凯 , Wu 吴 Lailei 来磊 , Lei 雷 Ming 鸣 , Gou 缑 Huiyang 慧阳 , Yu 于 Runze 润泽 
Published: September 2024

Abstract
Dynamic adsorption processes of reaction intermediates for alkaline hydrogen evolution (HER) catalysts are still confusing to understand. Here, we report a series of A-site ordered quadruple perovskite ruthenium-based electrocatalysts ACu3Ru4O12 (A = Na, Ca, Nd, and La), with the target sample SrCu3Ru4O12 exhibiting a very low overpotential (46 mV @10 mA·cm−2) and excellent catalytic stability with little decays after 48-h durability test. Precise tuning A-site cations can change the average valence state of Cu and Ru, thus the plot of HER activity versus the average Ru valence number shows a volcano-type relationship. Density functional theory indicates that the Ru 4d orbitals of SrCu3Ru4O12 possesses the most suitable d-band center position among the five samples, which might be the key parameter to determine the catalytic performance. Our work provides further insight into the discovering advanced, efficient hydrogen evolution catalysts through designing precise descriptor.
The feasibility of the L-H transition for a purely electron-heated EU-DEMO tokamak
Authors: Suárez López G. , Tardini G. , Fable E. , Siccinio M. , Zohm H. 
Published: September 2024

Abstract
We study numerically the feasibility of achieving the L-H transition in the current EU-DEMO tokamak baseline using uniquely direct electron heating. The ASTRA code coupled to the TGLF turbulent transport model is used to predict steady-state kinetic plasma profiles for diverse numerical scans. Among them, we have varied the separatrix electron density, the total amount of ECRH power, the microwave beam deposition profile and the plasma impurity content. The solutions are then compared to L-H transition scaling laws to assess whether the found plasma state would enter into H-mode. We find the plasma density and impurity content to be the key variables setting the boundaries in parameter space where the L-H transition is feasible. When impurities can be controlled under a certain threshold, given here for a fully shaped DEMO plasma, the L-H transition is achieved in all the studied conditions.
Effects of divertor geometry on detachment and core plasma performance with impurity seeding in EAST
Authors: Meng L.Y. , Wang L. , Liu J.B. , Li K.D. , Lin X. , Liu X.J. , Jia G.Z. , Guo J. , He T. , Yu L. , Tang P.J. , Xu J.C. , Zhang W.M. , Zhang L. , Yang J.J. , Duan Y.M. , Zhong F.B. , Zhang T. , Wang M.R. , Lin Z.C. , Jia T.Q. , Zhang B. , Zang Q. , Yu Y.W. , Chen Z.X. , Xu G.S. , Wan B.N. 
Published: September 2024

Abstract
Divertor detachment operation compatible with the core plasma is an effective method to alleviate the steady-state heat flux approaching the divertor target; this scheme will be adopted by high-performance tokamaks in the future, such as International Thermonuclear Experimental Reactor (ITER). Currently, two ITER-like tungsten divertors with different geometries have been installed at the top and bottom of Experimental Advanced Superconducting Tokamak (EAST), providing conditions for the present study to investigate the effect of divertor geometry on the compatibility between detachment and core plasma. Recent H-mode experiments show that the electron temperature and heat flux of the outer target of the lower divertor decrease lower than those of the upper divertor after similar amounts of impurity are truly injected into the plasma. SOLPS simulations further prove that the closed lower divertor with a ‘corner slot’ structure is beneficial for trapping impurity and deuterium particles, thereby increasing momentum and energy losses. For the upper single-null discharges, the divertor electron temperature can be relatively reduced by increasing impurity seeding, but it is also easy to decrease the plasma stored energy and even lead to an H-L back transition. In addition, statistical data on discharges with impurity seeding show that the proportion of detachment discharges achieved by using the closed divertor is higher than that achieved by using the open divertor. The discharges with the closed divertor after detachment have less damage to the core plasma performance than those with the open divertor, irrespective of whether neon or argon seeding is employed. This research will support long-pulse detachment operation in EAST and provide a reference for other tokamaks in divertor design.