bluuebunny/crossref_metadata_2025 huggingface dataset:
Future prospects for measuring 1PPN parameters using observations of S2 and S62 at the Galactic center
Authors: de Mora Losada Victor , Della Monica Riccardo , de Martino Ivan , De Laurentis Mariafelicia
Published: January 2025

Context. The parameterized post-Newtonian (PPN) formalism offers an agnostic framework for evaluating theories of gravity that extend beyond general relativity. Departures from general relativity are represented by a set of dimensionless parameters that, at the first order in the expansion, reduce to β and γ, which describe deviations in spatial curvature and nonlinear superposition effects of gravity, respectively.

Aims. We exploit future observations of stars at the Galactic center, orbiting the supermassive black hole Sagittarius A*, to forecast the ability to constrain the first-order PPN parameters γ and β.

Methods. We have generated a mock catalog of astrometric and spectroscopic data for S2, based on the Schwarzschild metric, simulating observations over multiple orbital periods with the GRAVITY and SINFONI instruments. Our analysis includes the effects of relativistic orbital precession and line-of-sight velocity gravitational redshift. Since future data for S2 can only provide constraints on a linear combination of the PPN parameters β and γ, we also analyzed the impact of future observations of the gravitational lensing on stars that pass closer in the sky to Sgr A*, such as the known star S62, which can potentially provide tight constraints on the parameter γ, which alone regulates the amplitude of the astrometric deviations due to lensing.

Results. When combining lensing observations for S62, and the precise orbital tracking of S2, one obtains independent constraints on both γ (with a potential precision as good as and β (with a corresponding precision of ~2%), providing a precision test of general relativity and its extensions.
Horizontal flows in the atmospheres of chemically peculiar stars
Authors: ud-Doula A. , Krtička J. , Kubátová B.
Published: January 2025

Context. Classical chemically peculiar stars exhibit atmospheres that are often structured by the effects of atomic diffusion. As a result of these elemental diffusion and horizontal abundance variations, the photospheric temperature varies at a given height in the atmosphere. This may lead to horizontal flows in the photosphere. In addition, the suppression of such flows by a magnetic field can alter the elemental transport processes.

Aims. Using a simplified model of such a structured atmosphere and 2D magnetohydrodynamic simulations of a typical He-rich star, we examined atmospheric flows in these chemically peculiar stars, which often are strongly magnetic.

Methods. We used Zeus-MP, which is a publicly available Fortran 90-based parallel finite element modular code.

Results. We find that for non-magnetic stars of spectral type BA, the atmospheric flow related to the horizontal temperature gradient can reach 1.0 km s−1, yielding mixing timescales of the order of tens of days. For the magnetic counterparts, the flow speeds are an order of magnitude lower, allowing for the stratification of chemical elements.

Conclusions. Magnetic fields can significantly influence the dynamics in atmospheres. A strong horizontal magnetic field inhibits flow in the vertical direction, while a strong vertical magnetic field can suppress horizontal atmospheric flow and prevent elemental mixing.
Repeated pattern of γ-ray flares in the blazar PKS 1502+106 coincident with the IC190730A neutrino event
Authors: Blinov Dmitry , Novikova Polina
Published: January 2025

Context. It has been demonstrated that at least 10% of the brightest blazars in the fourth Fermi-LAT catalog of γ-ray sources exhibit repeating patterns of γ-ray flares. These events may be associated with the presence of a non-uniform sheath surrounding a fast jet spine in some blazars. Theoretical models suggest that such a sheath could facilitate neutrino production in these structured jets.

Aims. We aim to test the marginal statistical evidence previously reported for a connection between repeating patterns of γ-ray flares in blazars and high-energy neutrino events that are positionally consistent with these sources.

Methods. We identified a repeating pattern of flares in the γ-ray light curve of the blazar PKS 1502+106, which lies within the 50% uncertainty region of the IC190730A neutrino candidate event. This occurrence is combined with two other high-energy (≥200 TeV) neutrino events from ICECAT-1, which arrived in both positional and temporal coincidence with two blazars exhibiting ongoing repeating flare patterns. We conducted a Monte Carlo simulation to evaluate the likelihood of accidental coincidences between the repeating flare patterns and neutrino events, accounting for potential unrecognized systematic uncertainties in the arrival directions of the ICECAT-1 events.

Results. Our findings indicate the probability of a random coincidence, in both time and arrival direction for three high-energy neutrino candidates and three blazars with ongoing recurring patterns of γ-ray flares, is 1.56 × 10−3 (3.2σ).
On Bose-condensation in two-dimensional Bose systems
Authors: Shevchenko S. I.
Published: January 2025

It is shown that Bose–Einstein condensation takes place in a two-dimensional Bose gas in an external field varying on the macroscopic scale. The transition temperature is calculated for different external fields.
On resistivity correlation in Ni–Cr–Fe alloys with density of electron states
Authors: Pecherskaya V. I. , Butenko A. V. , Kopeliovich A. I.
Published: January 2025

An analysis of the temperature dependence of the resistivity ρ(T) for alloys of the Ni–Cr–Fe system reveals that at T ≃100–300 K, the resistivity ρ changes linearly with temperature. Such a dependence ρ(T) can be explained by the phonon mechanism of conduction electron scattering taking into account the s- and d- charge carriers. The concentration dependence of the slope of straight lines ρ(T) is determined by the corresponding dependence of the density of electron states of these alloys.
Melting diagrams for binary systems based on hydrogen isotopes
Authors: Bereznyak N. G. , Sheinina A. A.
Published: January 2025

The method of determining melting diagrams of binary systems of hydrogen isotopes over a wide pressure range is developed. A technique is proposed for obtaining the melting diagrams at saturated vapor pressure and for computing the melting curves under pressure by using the law of corresponding states applicable for pure isotopes.
Relaxation of energized electrons during transverse focusing in bismuth
Authors: Andrievskii V. V. , Ass E. I. , Komnik Yu. F.
Published: January 2025

The energy dependence of the inelastic scattering length l(ε) of highly energized charge carriers in bismuth is determined by using the method of transverse electron focusing. It is found that for excess electron energy Δε ≥ εf the values of l remain large (approximately 10−2−10−3 cm). The role of thermal heating of the emitter in the region of high injection currents is discussed.
A rotor molecule in an atomic cryomatrix. I. Excess dilution volume
Authors: Brodyanskii A. P. , Strzhemechnyi M. A.
Published: January 2025

The problem of excess dilution volume of an isotropically dilating impurity is considered as a part of a more general problem of dilatation around a dumbbell impurity in an atomic lattice. Displacements u of neighboring atoms are calculated from static equilibrium conditions so that the values of u on the nine nearest coordination spheres are regarded as unknown, and the displacement on next spheres are taken equal to the values obtained in the long-wave approximation. A relation between the atomic displacement in the first sphere, the excess dilution volume ΔV and the extra force exerted by an impurity on the nearest neighbor is established. It is shown that the thermal variation of dilution volume from a temperature of about 10 K to the melting temperature is almost entirely due to a change in the normalization parameter (equal to the ratio of F to the elastic modulus) caused by the thermal variation of the lattice parameter. A comparison based on the previously suggested interaction potentials between N2 and CO impurities and Ar, Kr and Xe atoms shows a good agreement with x-ray data.
Line shape and superradiant bremsstrahlung half-width in superconducting films
Authors: Gogadze G. A.
Published: January 2025

The line shape and superradiant bremsstrahlung half-width are calculated in terms of the microscopic theory of inelastic scattering of quasiparticles at the boundary of a phase slip center. The power of generated voltage oscillations is estimated.
Phonon thermal conductivity of Y-based polycrystalline high-temperature superconductors
Authors: Merisov B. A. , Khadzhai G. Ya. , Gavrenko O. A. , Voronov A. P.
Published: January 2025

The thermal conductivity λ(T) of YBa2Cu3O7–δ polycrystals (Tc = 90 K) is measured in the temperature range 50–140 K. The thermal conductivity peak is observed at 50 K. No variation in the temperature dependence is observed after the superconducting transition, but the crystal lattice of the sample exhibits instabilities at 85–100 K. It is found that λ(T) = (AT + B)−1 in the temperature region 50–140 K (excluding the interval 85–100 K). This dependence is typical of heat transfer by phonons in the case of their scattering by phonons and point defects.
Peculiarities of quantum transfer for surface electrons on liquid helium in a magnetic field
Authors: Grigor’ev V. N. , Kirichek O. P. , Kovdrya Yu. Z. , Monarkha Yu. P.
Published: January 2025

The Hall effect is investigated in the layer of surface electrons on liquid helium in the temperature range 0.4–1.5 K for concentrations up to 109 cm−2 in a magnetic field up to 5 kOe. It is shown that the Hall voltage uH first increases with decreasing temperature, passes through the maximum at 0.65 K and then decreases. Such a behavior of uH is explained by an increase in the longitudinal resistivity of the electron layer due to an increase in the effective frequency of electron–ripplon collisions in the magnetic field.
Estimation of the temperature derivative of the upper critical field and its anisotropy in high-temperature superconductors from fluctuation effects in heat capacity and magnetic susceptibility
Authors: Mikitik G. P. , Panfilov A. S.
Published: January 2025

A method based on the analysis of fluctuational contributions to heat capacity and magnetic susceptibility is proposed for estimating the temperature derivatives of upper critical fields of high-temperature superconductors. The fluctuational contribution to the magnetic susceptibility of YBa2Cu3O7 is investigated experimentally and estimates of derivatives are obtained for this superconductor.
Liquid-phase preparation of Bi–Sr–Ca–Cu–O film structures
Authors: Kosmyna M. B. , Nazarenko B. P. , Rosenberg G. Kh. , Seminozhenko V. P. , Dmitriev V. M. , Kovalenko S. I. , Krainyukova N. V. , Khristenko E. V. , Zolochevskii I. V.
Published: January 2025

Textured Bi2Sr2CaCuOx (BSCCO) films were grown from a solution–melt with 10–30 wt.% BSCCO and 70–90 wt.% KC1. The substrates were of YA1O3 of orientation (110). The films consisted of crystallites up to 300 μ m in size ordered into grains, and their c-axis was perpendicular to the substrate plane. The films had zero resistance at 82–85 K, and the critical current density was 102 A/cm2 at 77 K.
Transferrin promotes fatty acid oxidation and liver tumor growth through PHD2-mediated PPARα hydroxylation in an iron-dependent manner
Authors: Qian Xu , Zhou Qimin , Ouyang Yuan , Wu Xiaohong , Sun Xue , Wang Shuo , Duan Yuran , Hu Zhiqiang , Hou Yueru , Wang Zheng , Chen Xiaohan , Wang Katherine L. , Shen Yuli , Dong Bofei , Lin Yanni , Wen Ting , Tian Qi , Guo Zhanpeng , Li Min , Xiao Liwei , Wu Qingang , Meng Ying , Liu Guijun , Ying Hangjie , Zhou Yahui , Zhang Wuchang , Duan Shengzhong , Bai Xueli , Liu Tong , Zhan Peng , Lu Zhimin , Xu Daqian
Published: January 2025

Tumor cells reshape iron and lipid metabolism for their rapid proliferation. However, how tumor cells coordinate the interplay between tumor cell–specific iron homeostasis and lipid metabolism reprogramming to counteract energy shortages remains unclear. Here, we demonstrated that glucose deprivation in hepatocellular carcinoma (HCC) cells induced AMPK-dependent Transferrin S685 phosphorylation, which exposed Transferrin nuclear localization signal (NLS) for binding to importin α7 and subsequent nuclear translocation. Nucleus-translocated Transferrin interacts with PPARα and enhance its protein stability to increase fatty acid oxidation (FAO) upon glucose deprivation. Mechanistically, PPARα-associated Transferrin upregulates iron-dependent PHD2-mediated PPARα P87 hydroxylation and subsequently disrupts the binding of MDM2 to PPARα, therefore inhibiting MDM2-mediated PPARα ubiquitination and degradation. Reconstitution of Transferrin S685A and NLS mutation or knock-in expression of PPARα P87A inhibited PPARα-mediated FAO upon energy stress, enhanced HCC cell apoptosis, and impeded liver tumor growth in mice. Importantly, combined treatment with Transferrin pS685 blocking peptide suppressing AMPK-Transferrin-PPARα axis could synergize with a well-established AMPK activator Metformin to inhibit tumor growth. Additionally, Transferrin pS685-mediated PPARα P87 hydroxylation is positively correlated with PPARα expression levels in human HCC specimens and poor patient prognosis. These findings revealed a mechanism by which Transferrin can sense energy stress to promote the hydroxylation and protein stability of PPARα through iron-dependent activation of PHD2 and underscore the moonlighting function of Transferrin in lipid catabolism and liver tumor development.
The Development of Speaker-Oriented Adverbs in English
Authors: Haumann Dagmar , Killie Kristin
Published: January 2025

The book investigates the development of ‘speaker-oriented adverbs’ (SOAs) such as frankly, surprisingly, and apparently in standard written English. SOAs take propositional scope, i.e. they modify clauses or sentences. It is generally assumed that they have developed from historically prior narrow-scope adverbs, e.g. adverbs modifying VPs. There is, however, disagreement about the mechanisms that brought the change about. Based on quantitative data, the book tests various hypotheses involving reanalysis of potentially ambiguous narrow-scope adverbs (often referred to as grammaticalization), ellipsis, lexicalization, and analogy. The data provide no clear evidence in favour of any of the hypotheses tested but suggest that different mechanisms may have been at work for different lexemes and subsets of SOAs. The book should appeal to researchers interested in the development and licensing of SOAs, but also to those with an interest in diachronic and syntactic change in general, or in grammaticalization, reanalysis, or subjectification in particular.
Half-time range description for the free space wave operator and the spherical means transform
Authors: Kuchment P , Kunyansky L
Published: January 2025

The forward problem arising in several hybrid imaging modalities can be modeled by the Cauchy problem for the free space wave equation. Solution to this problems describes propagation of a pressure wave, generated by a source supported inside unit sphere S. The data g represent the time-dependent values of the pressure on the observation surface S. Finding initial pressure f from the known values of g consitutes the inverse problem. The latter is also frequently formulated in terms of the spherical means of f with centers on S. Here we consider a problem of range description of the wave operator mapping f into g. Such a problem was considered before, with data g known on time interval at least

[
0
,
2
]

(assuming the unit speed of sound). Range conditions were also found in terms of spherical means, with radii of integration spheres lying in the range

[
0
,
2
]

. However, such data are redundant. We present necessary and sufficient conditions for function g to be in the range of the wave operator, for g given on a half-time interval

[
0
,
1
]

. This also implies range conditions on spherical means measured for the radii in the range

[
0
,
1
]

.
WR-3 wideband waveguide diplexers based on the perfectly symmetric Y-junction
Authors: Ding Jiangqiao , Jiang Luying , Lei Yalin , Zhao Yun , Li Sheng , Wang Caixia , Jiang Jun
Published: January 2025

In this work, two WR-3 band waveguide diplexers based on symmetrical H-plane and E-plane Y-junctions are developed, fabricated, and compared to highlight bandwidth performance. Both symmetrical H-plane and E-plane Y-junctions are first analyzed to determine the conditions for implementing wideband waveguide diplexers. Then a mid-band H-plane diplexer-I and a wideband E-plane diplexer-II are designed and demonstrated through CNC-milling technology. The measured results of H-plane diplexer-I show central frequencies of 251.5 GHz and 294 GHz, 3 dB fractional bandwidths (FBWs) of 5.6% and 3.3%, as well as insertion losses (ILs) of about 2 dB. The practical E-plane waveguide diplexer-II has achieved central frequencies of 264.5 GHz and 309 GHz, 3 dB FBWs of 11.4% and 6.2%, low ILs of 1.5 dB, as well as high isolation exceeding 50 dB. All the measured performance agree well with the simulation, verifying that the symmetrical E-pane Y-junction is optimal for the wideband waveguide diplexer. Additionally, such compact and scalable THz waveguide diplexers for future transceivers can meet the current CNC manufacturing constraints.
Enhancing photodetector performance via interlayer energy transfer in 2D hybrid perovskite heterostructures
Authors: Han Bin , Tang Yanren , Qiu Qi , Lian Bingtao , Liu Bo , Ding Shukai , Ma Shufang , Li Guoqiang , Xu Bingshe , Hsu Hsien-Yi
Published: January 2025

Two-dimensional (2D) organic–inorganic hybrid perovskites (OIHPs) have emerged as promising materials for optoelectronic devices due to their exceptional properties. However, their application is often hindered by limited charge transfer (CT) capabilities, attributed to the insulating organic spacer layers. In this study, we address this challenge by introducing a BA2MA2Pb3I10/PEA2MA2Pb3I10 heterostructure, which leverages interlayer energy transfer (ET) to overcome CT limitations. This ET mechanism leads to a substantial enhancement in photoluminescence (PL) emission, with the heterostructure displaying a ∼2.4-fold increase in PL intensity compared to pristine PEA2MA2Pb3I10. Additionally, encapsulating the heterostructure boosts PL emission by 5.2 times. The impact of ET on device performance was further demonstrated in photodetectors based on this heterostructure. These devices exhibited significant improvements in photoresponse, achieving a maximum responsivity of 10 A W−1, which are almost 10 times greater than those of devices fabricated from the individual BA2MA2Pb3I10 and PEA2MA2Pb3I10 devices. Additionally, the heterostructure device demonstrates rapid response times, with a rise time of 7 ms and a decay time of 4 ms, significantly outperforming both the pure BA2MA2Pb3I10 device (450 ms rise, 470 ms decay) and the PEA2MA2Pb3I10 device (350 ms rise, 370 ms decay). These findings highlight ET as an effective strategy for enhancing the optoelectronic performance of 2D OIHP-based devices, paving the way for high-efficiency applications in future photodetectors and other optoelectronic technologies.
Structural diversity and electronic properties of neodymium borides under high pressure
Authors: Sun Weiguo , Li Xiaofeng , Zhang Chuanzhao , Ju Meng
Published: January 2025

Rare earth (RE) borides have garnered significant attention due to their high mechanical strength, superconductivity, and novel electronic properties. In this study, we systematically investigate the structural, electronic, and mechanical properties of RE neodymium borides across a wide range of pressures. Various stoichiometries of Nd–B compounds are predicted using the unbiased CALYPSO structure search method and density functional theory calculations. Our findings indicate that the newly predicted NdB5, NdB7, and NdB8 compounds are thermodynamically and mechanically stable at high pressures. Detailed analyses of the electronic band structure and density of states reveal that all neodymium borides exhibit metallic behaviour. The hardness of the stable phases has been evaluated using an empirical model. Notably, NdB5 compound could also be dynamically and mechanically stable at ambient pressure with an estimated hardness of approximately 24.82 GPa, suggesting that NdB5 is a potential hard metal boride. Our results provide valuable insights into the structural, electronic, and mechanical properties of Nd–B compounds, enhancing our understanding of their potential applications in various fields.
Human fall detection based on adaptive local region-duration features using MIMO radar
Authors: Lin Jinhong , Yang Zhaocheng , Chu Ping , Lian Tongsheng , Zhou Jianhua
Published: January 2025

The existing radar-based human fall detection methods mostly consider relatively simple fall actions, overlooking the complexity of actual human falls involving different postures and speeds. Additionally, the dynamic changes in household items such as electric fans and curtains in real indoor environments can affect the performance of fall detection. To address these problems, we propose a human fall detection approach based on adaptive local region-duration features using multi-input multi-output radar. We first utilize multiple target detection and tracking to obtain target trajectory information. Then, we select local region and extract multidimensional dynamic sequences of targets based on their trajectory information. Finally, we adaptively intercept corresponding information sequences through suspicious fall event detection and extract adaptive local region-duration features for the classification of fall and non-fall events. The experimental results show that the proposed approach is capable of detecting various complex fall actions with different durations. Moreover, the proposed approach achieves an average accuracy of 98.2% and 98.0% in the absence and presence of interference, respectively.
Anatomy-wise lung ventilation imaging for precise functional lung avoidance radiation therapy
Authors: Chen Zhi , Li Zihan , Huang Yu-Hua , Teng Xinzhi , Zhang Jiang , Xiong Tianyu , Dong Yanjing , Song Liming , Ren Ge , Cai Jing
Published: January 2025

Objective. This study aimed to propose a method for obtaining anatomy-wise lung ventilation image (VIaw) that enables functional assessment of lung parenchyma and tumor-blocked pulmonary segments. The VIaw was used to define multiple functional volumes of the lung and thereby support radiation treatment planning. Approach. A super-voxel-based method was employed for functional assessment of lung parenchyma to generate VIsvd. In the VIsvd of the 11 patients with tumor blockage of the airway, the functional value in tumor-blocked segments was set to 0 to generate the VIaw. The lung was divided into regions of high functional volume (HFV), unrecoverable low functional volume (LFV), and recoverable LFV (rLFV, the region in the tumor-blocked segment with a high function value based on the VIsvd) to design three intensity-modulated photon plans for five patients. These plans were an anatomical-lung-guided plan (aPlan), a functional-lung-guided plan (fPlan), and a recoverable functional-lung-guided plan (rfPlan) where the latter protected both HFV and rLFV. Main results. The LFV in the reference ventilation images and the tumor-blocked segments had a high overlap similarity coefficient value of 0.90 ± 0.07. The mean Spearman correlation between the VIaw and reference ventilation images was 0.72 ± 0.05 for the patient with tumor blockage of the airway. The V20 and mean dose of rLFV in rfPlan were lower than those in aPlan by 12.1 ± 8.4% and 13.0 ± 6.4%, respectively, and lower than those in fPlan by 14.9 ± 9.8% and 15.9 ± 6.5%, respectively. Significance. The VIaw can reach a moderate-strong correlation with reference ventilation images and thus can identify rLFV to support treatment planning to preserve lung function.
Antenna miniaturization and application in-band interference reduction using dipole array mirror reflector FSS for Sub 6 GHz applications
Authors: Ara Shabnam , Prasanthi Kumari Nunna , Varshney Atul
Published: January 2025

This work contributes a compact FSS antenna novel dual-band miniaturized planar antenna for 5G Sub 6 GHz implementations and its design considered the challenge of designing an antenna with reduced dimensions, which in turn is expected to be more cost-effective to produce and exhibit lower interferences compared to existing market solutions. The low-loss double-layered miniaturized rectangular microstrip antenna consists a dipole strip array mirror reflector frequency selective surface (FSS) layer beneath the antenna ground at an optimized gap that makes the antenna multi-layered and improves its directional radiation characteristics. The existing antennas are based on the same principle of Fabry–Perot cavity interference and achieve ultra-wideband (UWB) bandwidth with a larger substrate size. Therefore, they have in-band applications interferences issues with 5G. These issues are remedies by reduction in the UWB bandwidth and substrate size miniaturization trade-off. A 74.11% antenna size miniaturization is achieved with a 47.6% reduction in the –10 dB bandwidth in comparison to the base antenna of size 49 × 49 mm2. The introduced notch-band (5.63–5.85 GHz) bifurcate the UWB bandwidth. Therefore, the notch band works as the boundary between the extra-applications bands (5.85–8.62 GHz) and 5G applications band (1.70–5.63 GHz) and eliminates in-band applications interferences. The overall volume of the 3D antenna is controlled by optimizing the two substrates gap. A parametric study of the modified miniaturized antenna dimensions has been conducted, and the simulation results were validated through experimental measurements. Since the antenna covers almost FR1 (1.0–6.0 GHz) range, therefore, it is the most appropriate candidate for all 5G bands including the main n77 (3.3–4.2 GHz), n78 (3.3–3.8 GHz), and n79 (4.4–5.0 GHz), Global System for Mobile Communication, Personal Communication Services (PCS), Wi-Fi/WLAN/Bluetooth, Wi-MAX (3.5 GHz), HiperLAN (5.8 GHz), C-band (5.85–8.0 GHz), and Lower 6G band (7.125–8.40 GHz) applications.
Ab-initio study of anomalous Hall and Nernst effects in equiatomic quaternary heusler alloy CoFeVGe
Authors: Pradhan Ripan , Rana Monika , Sharma Anurodh , Pathipati Srinivasa Rao , Turpu G R , Das Pradip , Lingam Chittari Bheema , Rambabu P
Published: January 2025

First-principles calculations were performed to investigate the electronic, magnetic, and topological properties of the nearly half-metallic ferromagnetic Heusler alloy CoFeVGe. The compound was found to exhibit mechanical and dynamical stability. We conducted a comprehensive study of the anomalous Hall and Nernst effects, attributed to Berry curvature induced by spin–orbit coupling (SOC). The maximum anomalous Hall conductivity (AHC) and anomalous Nernst conductivity (ANC) were determined to be −340.2S/m and  −1.26Am−1 K−1 at 300 K, respectively, within an energy window of ±300meV around the Fermi level E

F
. The temperature and chemical potential dependence of the anomalous Nernst conductivity was also explored. The Curie temperature (T

c
), estimated using mean-field approximation and magnetic Heisenberg exchange interactions, was found to be 489.3K. Additionally, magneto-optical Kerr effect calculations yielded a maximum polar Kerr angle of 0.19∘. Our results suggest that CoFeVGe is a promising candidate for spintronic and magneto-optical applications.
Invariant measures for some dissipative systems from the Jacobi last multiplier
Authors: Ghosh Aritra
Published: January 2025

Hamiltonian dynamics describing conservative systems naturally preserves the standard notion of phase-space volume, a result known as the Liouville’s theorem which is central to the formulation of classical statistical mechanics. In this paper, we obtain explicit expressions for invariant phase-space measures for certain (generally dissipative) mechanical systems, namely, systems described by conformal vector fields on symplectic manifolds that are cotangent bundles, contact Hamiltonian systems, and systems of the Liénard class. The latter class of systems can be described by certain generalized conformal vector fields on the cotangent bundle of the configuration space. The computation of the invariant measures is achieved by making use of the formalism of Jacobi last multipliers.
High-precision simulation and measurement of the aerial magnetic field in the near-area of underwater conventional electrode-type source
Authors: Pan Lindong , Jiang Zekun , Gao Junqi , Shen Ying , Li Yali , Yang Xiaobao , Wang Jiazeng , Chen Jiamin
Published: January 2025

The two-electrode straight open magnetic source (TSOMS) has been widely used in magnetic minesweepers and decoys. Achieving high-precision simulation of the near area magnetic field is crucial for its precise location. In this paper, we discuss the influence of the number of subdivision units on the calculation accuracy and time of the magnetic field of the TSOMS (MFTSOMS). The multiple electric dipole magnetic field (EDMF) accumulation method is combined with the 12-point Gaussian integral method to improve the precision of the near-area EDMF. We propose to use the EDMF algorithm (the frequency is infinitesimal) to verify the correctness of the MFTSOMS algorithm (DC). Our results show that both calculation accuracy (relative accuracy) and efficiency of the MFTSOMS can be taken into account when the subdivision unit number is 103 to 2 × 105 and must be larger than 10 l/S. We also find that the two algorithms agree well in the near and far areas when the length of the line electrode is infinitely small. Finally, we conduct a pool experiment to validate the effectiveness of the MFTSOMS algorithm.
Simulation analysis of nanobubble stability in horizontal pipeline
Authors: Liu Shurong , Li Qifen , Yang Yongwen , Lei Ming , Wang Jing , Zhang Liting
Published: January 2025

The distribution characteristics of nanobubbles in pipelines are crucial for their applications in energy storage, agriculture, and medicine. Current numerical simulations of gas-liquid mixing in pipelines fail to accurately capture the complex behavior of nanobubbles, limiting simulation efficiency and accuracy. To better understand nanobubble behavior in pipeline flow, this paper uses a population balance model and CFD to simulate changes in nanobubble size and quantity. Results indicate that bubble polymerization is dominant, with nanobubble size reaching a steady state as flow increases. Additionally, a higher inlet gas phase volume fraction leads to a more dispersed size distribution, increased size, and decreased density. This study offers optimization insights and a theoretical basis for nanobubble applications in pipeline transport.
Linear and nonlinear optimization for the HALF storage ring lattice
Authors: Xu Jianhao , Yang Penghui , Li Weimin , Wang Lin , Bai Zhenghe
Published: January 2025

Hefei Advanced Light Facility (HALF) is a VUV and soft X-ray
diffraction-limited storage ring, which uses a modified hybrid
multi-bend achromat (HMBA) lattice. In a HMBA lattice, many
nonlinear effects are cancelled by the -I transformation
between sextupoles. But for amplitude-dependent tune shifts (ADTS)
and high-order chromaticities, generally they cannot be controlled
well, which will limit the dynamic aperture and momentum aperture.
To further improve the performance of the HALF lattice, linear
parameters and nonlinear dynamics are optimized in this
paper. First, linear lattice, ADTS and second-order chromaticity are
simultaneously optimized with magnet strengths varied in large
ranges to better explore good solutions. In this optimization,
lattice solutions with both low emittances and relatively good
nonlinear dynamics are efficiently obtained. Then, starting from the
good solution region generated above, direct optimization of dynamic
aperture and Touschek lifetime based on particle tracking is
performed. After this second optimization, the lattices with larger
DAs and longer lifetimes are obtained for HALF. This method can
also be used for optimizing other HMBA lattices.
Synthesis and characterization of TiO2–ZnO composite thin films for biomedical applications
Authors: Engoor Gimmi Guruprasad , Dewangan Vimal Kumar , Latiyan Sachin , Sampath Kumar T S , Sujatha N , Palani I A , Vasa Nilesh J
Published: January 2025

Titania (TiO2) has superior biocompatibility, while zinc oxide (ZnO) is antibacterial. This investigation aimed to study the influence of TiO2–ZnO composite films on enhancing the biocompatibility of stainless steel (SS). Radio-frequency magnetron sputtering (RF-MS) technique is used to synthesize TiO2–ZnO composite thin films on 304-SS substrates from three sputtering targets with typical chemical compositions of 100% TiO2, 90%TiO2–10%ZnO, and 75%TiO2–25%ZnO, mixed by their respective weight percentages. The influence of surface chemistry, morphology, and wettability of TiO2–ZnO composite film on its osseointegration and antifouling characteristics was studied. The biocompatibility was assessed by protein adsorption kit, cytotoxicity assay, and cell adhesion of MG63 osteoblast cells, followed by S. aureus bacterial adhesion studies. All RF-MS films displayed hydrophobicity, minimal bacterial-cell adhesion, and higher cytocompatibility than the SS. RF-MS films deposited from the 75%TiO2–25%ZnO target exhibited the highest antifouling capability due to the least protein adsorption and the highest antibacterial ZnO concentration. However, increased ZnO concentration decreased MG63 cell viability. RF-MS films deposited from the 90%TiO2–10%ZnO target showed the highest mammalian cell viability of ≈88% and attachment. High plasma protein adsorption caused decreased mammalian cell viability and higher bacterial adhesion on 100% TiO2 film and SS. Biocompatible and antifouling TiO2–ZnO composite thin films on SS substrates offer an alternative to conventional antibiotic coatings to combat antimicrobial resistance (AMR) and biofilm-related infections.
Deformation behavior, critical strain, and processing maps of an as-extruded Mg-2.5Zn-4Y by hot compression tests
Authors: Wang Guoxin , Guan Ying
Published: January 2025

Hot compression tests were conducted on an as-extruded Mg-2.5Zn-4Y magnesium alloy using a Gleeble thermal simulation machine under various deformation conditions to investigate its hot deformation behavior. The results indicated that, at relatively high strain rates (1 s−1), the alloy exhibited limited dynamic recrystallization, with deformation primarily governed by dynamic recovery. Conversely, at lower strain rates (0.001 s−1 and 0.01 s−1), dynamic recrystallization became the dominant deformation mechanism. Flow stress and peak stress (σ
p) decreased with increasing temperature at constant strain rates. By contrast, at constant temperatures, both flow stress and σ
p increased with higher strain rates. Furthermore, at a constant temperature, a reduction in strain rate led to a decrease in the fraction of low-angle grain boundaries (LAGBs) and an increase in high-angle grain boundaries (HAGBs). Similarly, increasing the temperature (573–673 K ) at a constant strain rate resulted in a lower fraction of LAGBs, a higher fraction of HAGBs, more complete dynamic recrystallization, and an overall increase in average grain size. A critical strain prediction model for the alloy was also developed. Analysis of the processing map identified optimized processing conditions of 640–673 K and 0.001 s−1. Under these conditions, the alloy demonstrated excellent workability and enhanced mechanical properties.
Reflow soldering for low-cost electronics using near-infrared LEDs
Authors: Wenger Thomas , Schletterer Philipp , Reichenberger Marcus
Published: January 2025

Despite advances in soldering technology, the soldering of flexible, low-cost substrates such as polyethylene terephthalate (PET) remains a significant challenge, even when using low-temperature solders. This paper presents a novel approach to energy transfer that takes advantage of the varying absorption levels of materials in the near-infrared (NIR) spectrum to achieve selective heating of electronic assemblies. By combining the different absorption behaviours of bare PET and copper-clad PET with an irradiation concept that includes the use of NIR LEDs, it is possible to achieve a highly controlled and locally limited heating of the assemblies. An experimental soldering setup was utilised to identify the parameters that influence the process. The solder joints of the chip resistor components exhibited comparable microstructure and mechanical strength to those soldered by a convective method. The preliminary reliability tests demonstrated that the NIR soldering process produces high-quality solder joints. Further studies will address the remaining issues, such as solder beading and the soldering of more complex components and assemblies.
Quantum coding with finite thermodynamic resources
Authors: Xuereb Jake , Debarba Tiago , Huber Marcus , Erker Paul
Published: January 2025

Quantum direct coding or Schumacher compression generalised the ideas of Shannon theory, gave an operational meaning to the von Neumann entropy and established the term qubit. But remembering that information processing is carried out by physical processes prompts one to wonder what thermodynamic resources are required to compress quantum information and how they constrain one’s ability to perform this task. That is, if Alice and Bob only have access to thermal quantum states and clocks with finite accuracy, how well can they measure, encode and decode pure quantum state messages? In this work we examine these questions by modeling Alice’s typical measurement as a unitary involving a measurement probe, investigating imperfect timekeeping on encoding and decoding and considering the role of temperature in Bob’s appended qubits. In doing so, we derive fidelity bounds for this protocol involving the correlations Alice can form with their measurement probe, the variance of the clock’s ticks and the temperature of Bob’s qubits. Finally, we give an insight into the entropy produced by these two agents throughout the compression protocol by relating the resources they use to a quantum thermodynamic cooling protocol.
Classical and combinatorial Judd–Ofelt analysis of spectroscopic properties in Er-doped materials: TeO2–ZnO–BaO:Er3+ glasses
Authors: Hrabovsky Jan , Varak Petr , Oswald Jiri , Krystufek Robin , Dedic Vaclav , Slang Stanislav , Benes Ludvik , Wagner Tomas , Strizik Lukas
Published: January 2025

A systematic study of the doping ability of the TeO2–ZnO–BaO glassy system with Er3+ ions is presented to achieve strong Stokes/upconversion photoluminescence (UPL) emission and to determine the optimal experimental conditions for conducting Judd–Ofelt (JO) analysis in Er-doped materials using the newly introduced Combinatorial JO analysis in this work. Selected glassy samples across the TeO2–ZnO–BaO glass-forming region following the concentration trends of each constituent oxide were uniformly doped with 0.2 mol.

%

of Er2O3 but only those with high BaO content were found to be amorphous and optically homogenous. These samples exhibit strong photoluminescence (

≈

1.5

μ

m,

≈

2.7

μ

m) and UPL emission from visible to near-infrared spectral region. The intensities of Er3+ intra-4f electronic transitions were calculated on the basis of classical JO theory with derived phenomenological

Ω

2
,
4
,
6

parameters. Combinatorial analysis was introduced and employed to calculate JO parameters using all observed absorption bands and their mutual combinations. The presented results then enable the identification of critical absorption band combinations necessary for accurate JO analysis in Er3+-doped materials, ensuring consistent and reliable outcomes. Furthermore, these findings facilitate the recognition of suboptimal experimental conditions for performing JO analysis in other materials containing Er3+ ions.
Design and simulation of a multi-range thermal mass flowmeter for liquid flow rate measurement in microchannels
Authors: Chaboki Hossein Hosseinzadeh , Rahbar Shahrouzi Javad , Jodeiri Naeimeh
Published: January 2025

The design of advanced thermal mass flowmeters presents a significant challenge in meeting the diverse measurement needs of modern industries, notably in process engineering, micro air vehicles, biomedical, oil and petrochemicals, food, and pharmaceuticals. A key focus is the ability to cover a broad range of flow rates, particularly at lower levels. Employing modern techniques such as microfluidics facilitates the development of flexible thermal mass flowmeters specifically designed for low measurement ranges. This research explores the design and simulation of microscale calorimetric thermal mass flowmeters to address the growing demand for accurate measurements at low flow rates. Critical considerations for these devices include the unique conditions of microfluidic systems, necessitating careful evaluation to ensure the feasibility of fabricating microcalorimetric thermal mass flowmeters. The design considerations can be divided into three categories: microgeometry, transfer phenomena, and range selectivity. Key factors such as geometric parameters in miniature dimensions, temperature and velocity distributions, effects of distributors, and measurement range determinations are scrutinized against constraints like linearity and cavitation. The study centers on measuring flow rates through square microchannels with a hydraulic diameter of 500 μm. A multi-range system allows for comprehensive coverage of the flow rate range while preserving the device’s flexibility and ensuring accurate performance. A microchip prototype configured with 1 to 10 flow paths demonstrated the capability to support flow rates from 0 to 100, achieving an R2 value of 0.98 across temperature differentials of less than 10 degrees, affirming its linearity and precision.
Tribological assessment of rice paddy straw filled green modified phenol formaldehyde composites
Authors: Girase Shailendrasingh B , Kothavale Basavraj S , Kulkarni M B , Gholam Nikhil , S Radhakrishnan , Siva I
Published: January 2025

Natural fiber composites are the subject of significant research because of environmental concerns worldwide. In this perspective, the present study explores the suitability of silica-rich rice paddy straw (PS), an agricultural waste to create a biodegradable material for use in industries such as automotive, packaging, construction and furniture (e.g. particle boards). This approach aims to reduce the environmental damage caused by burning PS fibers and deforestation. Several researchers have used filler material up to 40%. The present study examines the tribological behaviour of PS composites that included over 50% PS fibers as a filler material, along with cashew nut shell liquid (CNSL) treated phenolic resin as a matrix in composites. The phenolic resin is formulated in three different matrix-to-filler (MF) ratios 1:1, 1:3 and 1:5. Fabricated composites are subject to water aging to understand the degradation behaviour of the phenolic composites. The experimental results reveal that all CNSL-treated formulations have greater wear resistance, fade resistance, fire resistance, and a more stable coefficient of friction (COF) than untreated formulations because of their plasticization and flexibility properties. The COF variation for treated 1:1, 1:3, and 1:5 MF formulations is less than that of untreated formulations, ranging from 3 to 33%, 0 to 12%, and 7 to 13%, respectively. Due to CNSL treatment, wear is reduced for 1:3 and 1:5 MF formulations by 20%–25% and 14%–55%, respectively, and variation in wear for 1:1 is 5 to 166%. Wear for 1:3 and 1:5 MF water-soaked treated formulations increases from 95% to 244% and 8% to 37%, respectively. From a tribology perspective, the 1:5 MF CNSL-treated formulation performed better than others in all respects. Further electron images explored the wear mechanism exerted during the abrasion.
How to build resilient community energy systems? Lessons from Malawi and Ethiopia
Authors: Vallecha Harshit , Gebreslassie Mulualem , Filli Fana , Hara Christopher , Gogoda Chrispin , Assefa Amare , To Long Seng , Kirshner Joshua , Castán Broto Vanesa
Published: January 2025

This paper defines the notion of realising resilient community energy systems (R-CESs) through community capital to withstand unforeseen natural hazards, climate change induced risks and socio-political disruptions. It evaluates the interrelationship between different stages of CES project implementation with the development of the community’s resilience in the form of social, human, economic, physical and natural capital. This study employs empirical research by carrying out case study analysis of CES projects deployed in risk-prone regions of Malawi and Ethiopia. Three CES projects, two in Malawi and one in Ethiopia, have been examined through qualitative analysis of data collected through semi-structured interviews with CES project stakeholders. Case studies analysed the role of different stakeholders in planning, installation, and operation of projects and the evolution of the community’s resilience during phases of project implementation. In-depth critical analysis of cases demonstrates how a community’s evolved resilience in different forms of community capital enables it to cope with unforeseen shocks/disruptions encountered over the period of CES operation. Comparative analysis of cases proposed the novel R-CES framework defining seven key components of community capital to realise a R-CES in practice. The proposed framework provides recommendations and best practices to CES project developers, managers and community representatives to implement CES projects in a way that strengthens community capital to thus realise a resilient community and sustainable infrastructure.
The Nothing
Authors: Bruno G Anthony
Published: January 2025

Chapter 6 shows that Heidegger diverges from German idealism by dissolving rather than solving the rhapsody problem. It argues that whereas the German idealists regard this problem as demanding a deductive solution, Heidegger denies that determining conditions of intelligibility can be deductive, since philosophical deduction, like any meaningful project, presupposes factical conditions that must be hermeneutically interpreted. The chapter then demonstrates that Heidegger improves on various aspects of Schelling’s, Lask’s, and Dilthey’s critical responses to German idealism. Next, it shows how Heidegger’s hermeneutics of facticity reveals an unspoken truth in ‘nihil ulterius,’ Kant’s phrase for the groundlessness of conditions of intelligibility. The truth is that there is no intelligible existence without what he calls ‘the nothing,’ which denotes the radical contingency that there are beings at all. Heidegger thereby effects an intensified return to Kant’s tolerance for radical contingency, casting reason’s peculiar fate not in the theoretical terms of undeniable, unanswerable questions of metaphysics, but rather in the concrete terms of the lived experience into which we are always already thrown.