bluuebunny/crossref_metadata_2025_split huggingface dataset:
CoFeBX layers for MgO-based magnetic tunnel junction sensors with improved magnetoresistance and noise performance
Authors: Matos F. , Macedo R. , Freitas P. P. , Cardoso S. 
Published: February 2023

Magnetoresistive sensors have been enthusiastically selected for applications requiring magnetic field detection with small footprint sensors. The optimisation of the sensor response includes using soft magnetic free layers, based on CoFeB and NiFe alloys. Here we report the TMR and noise performance of magnetically saturated in-plane MTJ sensors including CoFeBTa and CoFeSiB soft magnetic films as free layers (FL). Assessing magneto-crystalline anisotropy μ0Hk values of 2.1 and 0.7 mT in CoFeB 2.5 (nm)/Ru 0.2/CoFeBTa 4 and CoFeB 3/Ru 0.2/CoFeSiB 4 compared to 1.7 mT in CoFeB 2.5/Ru 0.2/NiFe 4, together with an improved magnetoresistance of 230% in CoFeBSi comparing with 170% (NiFe) with superior noise characteristics, with Hooge parameter of αH = 7 × 10−11 μm2.
Finite image size effects on the characterization of magnetic domain patterns via magnetic force microscopy
Authors: Vaka Michael , Ray Joey , Campos Misael , Chesnel Karine 
Published: February 2023

Optimizing magnetic thin films for nanotechnologies often requires imaging nanoscale magnetic domain patterns via magnetic microscopy. The finite size of the image may however significantly affect the characterization of the observed magnetic states. We evaluated finite image size effects on the characterization of a variety of stripe and bubble domain patterns exhibited by ferromagnetic Co/Pt multilayers with perpendicular magnetic anisotropy, where the domain size (stripe width and bubble diameter) is around 100 nm. If the image size is too small, below ∼5 μm, it may cause a significant underestimation of average domain size and overestimation of domain density by up to a factor 5 when reducing the image size from about 20 μm to about a 1 μm. Using a criterion based on how the excess density evolves with image size, we found that to obtain reliable statistical estimates of domain density and average domain size, the image needs to be large enough, and include at least about 100 stripes or about 2500 bubbles.
In-plane thermoelectric properties of graphene/xBN/graphene van der Waals heterostructures
Authors: Makumi Sylvester W , Bem Daniel , Musila Nicholas , Foss Cameron , Aksamija Zlatan 
Published: February 2023

Abstract
2D materials have attracted broad attention from researchers for their unique electronic properties, which may be been further enhanced by combining 2D layers into vertically stacked van der Waals heterostructures (vdWHs). Among the superlative properties of 2D systems, thermoelectric (TE) energy conversion promises to enable targeted energy conversion, localized thermal management, and thermal sensing. However, TE conversion efficiency remains limited by the inherent tradeoff between conductivity and thermopower. In this paper, we use first-principles calculation to study graphene-based vdWHs composed of graphene layers and hexagonal boron nitride (h-BN). We compute the electronic band structures of heterostructured systems using Quantum Espresso and their TE properties using BoltzTrap2. Our results have shown that stacking layers of these 2D materials opens a bandgap, increasing it with the number of h-BN interlayers, which significantly improves the power factor (PF). We predict a PF of ∼1.0 × 1011 W K−2 m s for the vdWHs, nearly double compared to 5 × 1010 W K−2 m s that we obtained for single-layer graphene. This study gives important information on the effect of stacking layers of 2D materials and points toward new avenues to optimize the TE properties of vdWHs.
Indoor radon survey in Whitehorse, Canada, and dose assessment
Authors: Hansen Violeta , Sabo Angela , Korn Juergen , MacLean Douglas , Rigét Frank Farsø , Clausen Daniel Spelling , Cubley Joel 
Published: February 2023

Abstract
Radon-222 (222Rn) and its decay products are the primary sources of a population’s exposure to background ionizing radiation. Radon decay products are the leading cause of lung cancer for non-smokers and the second leading cause of lung cancer after smoking for smokers. A community-driven long-term radon survey was completed in 232 residential homes in different subdivisions of Whitehorse, the capital of the Yukon, during the heating season from November to April in 2016–2017 and in 2017–2018. Radon concentrations were measured in living rooms and bedrooms on ground floors. The arithmetic and geometric means of indoor radon activity concentrations in different subdivisions of Whitehorse ranged from 52 ± 0.6 Bq m−3 and 37 ± 2.3 Bq m−3 in the Downtown area of Whitehorse to 993.0 ± 55.0 Bq m−3 and 726.2 ± 2.4 Bq m−3 in Wolf Creek. Underlying geology and glacial surfaces may partly explain these variations of indoor radon concentrations in subdivisions of Whitehorse. A total of 78 homes (34.0%) had radon concentrations higher than 100 Bq m−3, 47 homes (20.5%) had concentrations higher than 200 Bq m−3 and 33 homes (14.4%) had concentrations higher than 300 Bq m−3. The indoor radon contribution to the annual effective inhalation dose to residents ranged from 3.0 mSv in the Downtown area to 51.0 mSv in Wolf Creek. The estimated annual average dose to adults in Whitehorse, Yukon, is higher than the world’s average annual effective dose of 1.3 mSv due to the inhalation of indoor radon. The annual radon inhalation effective dose was assessed using radon measurements taken during winter; hence the assessed dose may be overestimated. Cost-efficient mitigation methods are available to reduce radon in existing buildings and to prevent radon entry into new buildings.
Weak signal enhancement for rolling bearing fault diagnosis based on adaptive optimized VMD and SR under strong noise background
Authors: Luo Jianqing , Wen Guangrui , Lei Zihao , Su Yu , Chen Xuefeng 
Published: February 2023

Abstract
Owing to the nonlinearity and nonstationarity of the bearing fault signal, it is difficult to identify fault characteristics under the influence of a strong noise environment. The extraction of early weak fault features is critical for the reliability of bearing operations. Therefore, an urgent problem is reasonable noise reduction and feature enhancement in weak-signal processing. Traditional variational modal decomposition (VMD) and stochastic resonance (SR) are commonly applied to detect weak signals in fault diagnosis. The VMD method can decompose the signal into several intrinsic mode functions (IMFs) to effectively reduce the modal aliasing problem. However, uniform standards for the key parameters of decomposition and the selection of the optimal IMF after decomposition are lacking. Meanwhile, some disadvantages of SR still exist; for example, the interference of multiscale noise may lead to false detection by incorrect selection of high-pass filter parameters, and the system parameters are not adaptive to different signals to achieve the best response output. To better address the weak signal feature enhancement, a novel rolling bearing fault diagnosis method combining adaptive VMD and SR by improved differential search (IDS) optimization is proposed. First, the bearing fault signal is decomposed into several IMFs using the IDS-VMD. Second, the feature information of the fault signal is retained and reconstructed using the correlation kurtosis for sensitive modal extraction. Furthermore, the fault features of the reconstructed signal are effectively enhanced by the variable-step IDS-SR, which can reasonably transfer the noise energy of the input components to the fault characteristic frequency. Finally, the periodic pulse can be observed in the corresponding envelope spectrum. The simulated and experimental data show that the proposed method can not only effectively extract the signal feature information in the actual fault but also realize early weak fault diagnosis of rolling bearings more accurately.
Insulated rail joint (IRJ) contact characterisation-an ultrasonic reflectometry approach for a cross-material interface
Authors: Zhou Lu , Luo Yun-Ke , Lewis Roger 
Published: February 2023

Abstract
Vehicle–track interaction at insulated rail joints (IRJs) plays a significant role in the wear evolvement and damage of the IRJ components. It is, however, challenging to characterise the contact conditions within the region non-destructively and accurately using experimental tools, especially when the IRJ contact involves both wheel–rail and wheel–endpost contact pairs. This study presents an ultrasonic technique to monitor and characterise static IRJ contacts in a non-invasive manner. The proposed ultrasonic reflectometry technique can realise high-resolution visualisation of contact patch and contact pressure distribution for both wheel–rail contact and wheel–endpost contact, by striking a beam of focused ultrasonic signals at the contact interface. Different data post-processing strategies are applied for the two types of contacts and a deconvolution algorithm is applied to rectify the measurements near the rail–endpost boundary. The ultrasonic measurements are verified through finite element simulations and the results show good agreement with each other in terms of both contact area and contact pressure level. It is expected that the proposed ultrasonic approach can be a reliable tool to assist in revealing the contact behaviour of IRJs more profoundly.
Optimized hydrodynamic interactions in phalanx school arrays of accelerated thunniform swimmers
Authors: Abouhussein Ahmed , Peet Yulia T 
Published: February 2023

Abstract
Optimal fish array hydrodynamics in accelerating phalanx schools are investigated through a computational framework which combines high fidelity Computational Fluid Dynamics (CFD) simulations with a gradient free surrogate-based optimization algorithm. Critical parameters relevant to a phalanx fish school, such as midline kinematics, separation distance and phase synchronization, are investigated in light of efficient propulsion during an accelerating fish motion. Results show that the optimal midline kinematics in accelerating phalanx schools resemble those of accelerating solitary swimmers. The optimal separation distance in a phalanx school for thunniform biologically-inspired swimmers is shown to be around 2L (where L is the swimmer’s total length). Furthermore, separation distance is shown to have a stronger effect, ceteris paribus, on the propulsion efficiency of a school when compared to phase synchronization.
Valence subbands profile regulation in AlGaN quantum well based on k·p theory
Authors: Wang Xianjun , Jiang Ke , Sun Xiaojuan , Zhang Zi-Hui , Chen Yuxuan , Wang Bingxiang , Li Dabing 
Published: February 2023

Abstract
The profiles for the valence subbands of an AlGaN-based quantum well (QW) is investigated by considering quantum confinement effect (QCE) and strain through the
k
·
p
theory. We have found that to increase the QCE and the compressive strain would rise the relative position of the heavy hole (HH) subband to the crystal field splitting hole (CH) subband in the valence band of the QW. However, although the variation trend of the relative valance subbands position is similar, the underlying mechanisms of the modulation by the QCE and strain are not the same. In addition, we have found that if the energy level between the HH and the CH subbands is close at a certain
k

t

point, the subband anti-crossing effect of the QW will enhance their coupling level, causing dipole moments from the conduction subbands to these valence subbands transformation between each other. These results can provide important basis for the active region design of some AlGaN-based short wavelength, high carrier injection, or monolithic integration optoelectronic devices.
Synergetic role of Ni and GOns to improve the microstructure and mechanical creep rate of Sn-5.0Sb-0.7Cu solder alloy
Authors: Mousa M M , Mahmoud M A , El-Zhery M M , Sobhy M 
Published: February 2023

Abstract
The role of minor additions of Ni and GOns to Sn- 5 wt% Sb- 0.7 wt% Cu (SSC-507) has been explored. Findings of scanning electron microscopy (SEM), energy dispersive x-ray spectrometry (EDX), and x-ray diffractometry (XRD) display the new phases like (Cu,Ni)6Sn5 and the size decrement of β-Sn grains. A slight increase in the melting temperature was observed using differential scanning calorimetry (DSC) analysis due to adding Ni (ΔTm = 1.02 °C) and GOns (ΔTm = 0.75 °C). Interestingly, 0.1 wt% Ni addition reduced the under-cooling by ∼28%, whenever adding of 0.1 wt% GOns enhanced the under-cooling by ∼115%. The average size of β-Sn grains of SSC-507 plain solder was decreased from ∼150 to ∼70 μm due to adding of Ni and then GOns. The enhanced creep resistance of SSC-Ni-GOns alloy motivated the values of creep fracture and enhanced the stress exponent parameters (n) by ∼27%. The outcomes of tensile creep examination demonstrate that increasing levels of stress and testing temperatures raise the steady-state creep rates for all tested alloys. The average activation energy (E) for the three solders ranged from ∼46.5 kJ mol−1 to ∼54.3 kJ mol−1 which close to that of pipe-diffusion mechanism in Sn based solder alloy.
Model for anisotropic compact stars via Chaplygin equation of state in Tolman space-time
Authors: Kumar Mahesh , Kumar Jitendra 
Published: February 2023

AbstractIn this work, we construct a unique anisotropic solution for spherically symmetric spacetime by investigating the Chaplygin EOS for the anisotropic fluid distribution. For generating the solutions, we have used Tolman metric potential Tolman R C (1939Phys. Rev.,55, 364–373) to solve the field equations. The anisotropic solution gives well behaved results and the energy conditions are fully satisfied. The TOV equation, Harrison-Zeldovik-Novikov criteria, and adiabatic index have been used to verify the stability of the model. Because this model meets all of these characteristics, it may be used to investigate realistic compact objects. We have also used this model to calculate the masses and radii of compact stars like Her X-1, 4U 1538-52, SAX J1808.4-3658, and LMC X-4, and found that these values were consistent with observational data which was derived using the provided solution.
Evidence of fresh cosmic ray in galactic plane based on DAMPE measurement of B/C and B/O ratios
Authors: Zhang Pei-Pei , He Xin-Yu , Liu Wei , Guo Yi-Qing 
Published: February 2023

Abstract
More and more experiments have identified that the energy spectra of both primary and secondary cosmic-rays exhibit a hardening above ∼ 200 GV. More recently, the DAMPE experiment has reported a hardening of boron-to-carbon ratio at 200 GV. These signs call for modifications of the conventional cosmic-ray (CR) picture. In this work, we propose that the plethoric secondary cosmic rays, for example, boron, antiprotons, originate from the hadronic interactions of freshly accelerated cosmic rays with the interstellar gas near the sources. We find that secondary-to-primary ratios, for example, boron-to-carbon, boron-to-oxygen and antiproton-to-proton ratios, can be well described. The measurements of electrons and positrons can also be accounted for.
Spatial search by continuous-time quantum walk on truncated simplex lattices
Authors: Zhu Xuanmin , Deng Yuanchun , Zhang Dezheng , Gao Runping , Wei Qun , Luo Zijiang 
Published: February 2023

Abstract
Quantum search via continuous-time quantum walk on truncated simplex lattices is an important example of the quantum search on the structured database. In this letter, when the search target is a set of the marked vertices, the run time of the quantum search and the critical jumping rates are derived. Quantum search with the partial information of the location of the marked vertex is also discussed. Furthermore, with the edge weights suitably adjusted, the three-stage search process can be optimized into a two-stage quantum search algorithm on the second-order truncated simplex lattice.
Limiting Magnitudes of the Wide Field Survey Telescope (WFST)
Authors: Lei Lei , Zhu Qing-Feng , Kong Xu , Wang Ting-Gui , Zheng Xian-Zhong , Shi Dong-Dong , Fan Lu-Lu , Liu Wei 
Published: February 2023

Abstract
Expected to be of the highest survey power telescope in the northern hemisphere, the Wide Field Survey Telescope (WFST) will begin its routine observations of the northern sky since 2023. WFST will produce a lot of scientific data to support the researches of time-domain astronomy, asteroids and the solar system, galaxy formation and cosmology and so on. We estimated that the 5σ limiting magnitudes of WFST with 30 s exposure are u = 22.31 mag, g = 23.42 mag, r = 22.95 mag, i = 22.43 mag, z = 21.50 mag, w = 23.61 mag. The above values are calculated for the conditions of airmass = 1.2, seeing = 0.″75, precipitable water vapor = 2.5 mm and Moon-object separation = 45° at the darkest New Moon night of the Lenghu site (V = 22.30 mag, Moon phase θ = 0°). The limiting magnitudes in different Moon phase conditions are also calculated. The calculations are based on the empirical transmittance data of WFST optics, the vendor provided CCD quantum efficiency, the atmospherical model transmittance and spectrum of the site. In the absence of measurement data such as sky transmittance and spectrum, we use model data.
3D Kinematics of Classical Cepheids According to Gaia EDR3 Catalog
Authors: Bobylev V. V. , Bajkova A. T. 
Published: February 2023

Abstract
The kinematics of about 2000 classical Cepheids of the Milky Way with data from Gaia EDR3 catalog has been studied. For some of these stars, there are line-of-sight velocities. On the basis of the nonlinear rotation model, the parameters of the rotation curve of the Galaxy were determined. The circular linear rotation velocity of the near-solar neighborhood around the Galaxy center was V
0 = 236 ± 3 km s−1 for the assumed Sun’s galactocentric distance R
0 = 8.1 ± 0.1 kpc. Analysis of residual velocities of Cepheids based on the linear Ogorodnikov–Milne model showed the presence of the following significantly different from zero gradients: ∂U/∂x, ∂U/∂z, ∂V/∂x, ∂V/∂z and ∂W/∂x, which behave differently depending on the selection radius. The most interesting is the gradient ∂W/∂x ∼ − 0.5 ± 0.1 km s−1 kpc−1 (positive rotation of this star system around the Galactic axis y, Ω
y
) since the velocities W are free of Galactic rotation. Here we have an indirect influence of various effects leading to a perturbation of the vertical velocities of the Galactic disk stars. Based on a simpler model, a more accurate estimate of this rotation is obtained, Ω
y
= 0.51 ± 0.07 km s−1 kpc−1.
The new monolithic ASIC of the preshower detector for di-photon measurements in the FASER experiment at CERN
Authors: Gonzalez-Sevilla S. 
Published: February 2023

Abstract
The ForwArd Search ExpeRiment (FASER) is an experiment searching for new light and weakly-interacting particles at CERN’s Large Hadron Collider. FASER is composed of different sub-detectors, including silicon microstrip detectors, scintillator counters and an electromagnetic calorimeter. In this paper, a new preshower detector for the FASER experiment is presented. The new detector, based on monolithic pixel ASICs, will provide excellent spatial and time resolutions and a large charge dynamic range. First results from a prototype chip produced by IHP in 130 nm SiGe BiCMOS technology are shown.
A wide-band, high-resolution vacuum flat crystal spectrometer for LEAF facility
Authors: Wang W. , Shao C.J. , Yang Y. , Yu D.Y. , Xue Y.L. , Cai X.H. 
Published: February 2023

Abstract
A wide-band, high-resolution vacuum flat-crystal
spectrometer was developed for analyzing the x-rays spectra of
hollow atoms. The spectrometer was designed to cover an energy
dynamic range of 0.6 to 16 keV by combining different flat crystals
and an x-ray CCD detector mounted on a twistable bellows that could
modulate the Bragg angles ranging from 25° to 50°.The
performance of the spectrometer was evaluated in energy range of
3–12 keV by measuring the K and L x-rays generated by
10–30 keV electron beam collisions with solid titanium, silver and
gold targets, respectively. The typical resolving power of the
spectrometer is estimated to be around 103, with a single
exposure measurement range of 144–1411 eV and corresponding energy
resolution of 3.5–33.2 eV. This spectrometer could be utilized
to investigate the fine hyper-satellite line structure of hollow
atoms with 10 ≤ Z ≤ 26.
Fabrication of mechanical skeleton of small-diameter vascular grafts via rolling on water surface
Authors: Li Shuo , Yang Lei , Zhao Zijian , Wang Jie , Lv Hongying , Yang Xiaoniu 
Published: February 2023

Abstract
Mimicking the multilayered structure of blood vessels and constructing a porous inner surface are two effective approaches to achieve mechanical matching and rapid endothelialization to reduce occlusion in small-diameter vascular grafts. However, the fabrication processes are complex and time consuming, thus complicating the fabrication of personalized vascular grafts. A simple and versatile strategy is proposed to prepare the skeleton of vascular grafts by rolling self-adhesive polymer films. These polymer films are directly fabricated by dropping a polymer solution on a water surface. For the tubes, the length and wall thickness are controlled by the rolling number and position of each film, whereas the structure and properties are tailored by regulating the solution composition. Double-layer vascular grafts (DLVGs) with microporous inner layers and impermeable outer layers are constructed; a microporous layer is formed by introducing a hydrophilic polymer into a polyurethane (PU) solution. DLVGs exhibit a J-shaped stress–strain deformation profile and compliance comparable to that of coronary arteries, sufficient suture retention strength and burst pressure, suitable hemocompatibility, significant adhesion, and proliferation of human umbilical vein endothelial cells. Freshly prepared PU tubes exhibit good cytocompatibility. Thus, this strategy demonstrates potential for rapid construction of small-diameter vascular grafts for individual customization.
Design of novel bioadhesive chitosan film loaded with bimetallic gold-silver nanoparticles for antibiofilm and wound healing activity
Authors: Singh Chandrashekhar , Mehata Abhishesh Kumar , Vikas  , Tiwari Punit , Setia Aseem , Malik Ankit Kumar , Singh Sanjeev K , Tilak Ragini , Muthu Madaswamy S 
Published: February 2023

Abstract
Microbial infections and antibiotic resistance are among the leading causes of morbidity and mortality worldwide. The bimetallic chitosan (CS)-capped gold-silver nanoparticles (CS-AuAg-NPs) were prepared by the seeded growth synthesis technique. The nanoparticles were optimized for particle size (PS), zeta potential (ZP) and antibacterial activity by Box–Behnken design at three levels and three factors. The developed CS-AuAg-NPs were polydispersed with mean hydrodynamic PS in the range of 55 – 289 nm and ZP ranges from +8.53 mV to +38.6 mV. The optimized CS-AuAg-NPs found to have a minimum inhibitory concentration and minimal bactericidal concentration of 1.625 ± 0.68 and 3.25 ± 0.74 µg ml−1 towards multidrug resistant (MDR) Staphylococcus aureus ATCC 25923 (MDR AT) and 3.25 ± 0.93 and 3.25 ± 0.86 µg ml−1 towards MDR S. aureus clinical isolate MDR1695 (MDR CI) strain, respectively. The CS-AuAg-NPs were much more effective against MDR AT and MDR CI compared to clindamycin standard. The live/dead assay of clinical isolates strain demonstrated significant reduction of bacterial cells ∼67.52 folds compared to control group in 12 h. The hemolysis study suggested that CS-AuAg-NPs were non-hemolytic and safer for application in the wound. Furthermore, CS-AuAg-NPs were distributed in the CS film, which showed 87% wound recovery after 7 d in mice model. Hence, we concluded that CS-AuAg-NPs was safer and more effective against MDR bacteria and capable of skin regeneration in the infected wound.