bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of depth of interaction resolution on the spatial resolution of SIAT aPET
Authors: Kuang Zhonghua , Zhang Ling , Ren Ning , Kinyanjui Samuel M , Liu Zheng , Sun Tao , Hu Zhanli , Yang Yongfeng 
Published: October 2023

Abstract

Objective. Spatial resolution is a crucial parameter for a positron emission tomography (PET) scanner. The spatial resolution of a high-resolution small animal PET scanner is significantly influenced by the effect of depth of interaction (DOI) uncertainty. The aim of this work is to investigate the impact of DOI resolution on the spatial resolution of a small animal PET scanner called SIAT aPET and determine the required DOI resolution to achieve nearly uniform spatial resolution within the field of view (FOV). Approach. The SIAT aPET detectors utilize 1.0 × 1.0 × 20 mm3 crystals, with an average DOI resolution of ∼2 mm. A default number of 16 DOI bins are used during data acquisition. First, a Na-22 point source was scanned in the center of the axial FOV with different radial offsets. Then, a Derenzo phantom was scanned at radial offsets of 0 and 15 mm in the center axial FOV. The measured DOI information was rebinned to 1, 2, 4 and 8 DOI bins to mimic different DOI resolutions of the detectors during image reconstruction. Main results. Significant artifacts were observed in images obtained from both the point source and Derenzo phantom when using only one DOI bin. When accurate measurement of DOI is not achieved, degradation in spatial resolution is more pronounced in the radial direction compared to tangential and axial directions for large radial offsets. The radial spatial resolutions at a 30 mm radial offset are 5.05, 2.62, 1.24, 0.86 and 0.78 mm when using 1, 2, 4, 8, or 16 DOI bins, respectively. The axial spatial resolution improved from ∼1.3 to 0.7 mm as the number of DOI bins increased from 1 to 16 at radial offsets from 0 to 25 mm. Two DOI bins are required to obtain images without significant artifacts. The required DOI resolution is about three times the crystal width of SIAT aPET to achieve a uniform submillimeter spatial resolution within the central 60 mm FOV and resolve the 1 mm rods of the Derenzo phantom at both positions.
Development of a novel single-mode miniature standing wave ultrasonic motor
Authors: Pan Qiaosheng , Wang Ya , Wan Aode , Li Chen , Zhao Mingfei , Li Ruijun 
Published: October 2023

Abstract
A novel single-mode miniature standing wave ultrasonic motor (SUSM) is proposed. The SUSM uses the first extension vibration mode and second extension vibration mode of the stator to generate different diagonal vibration trajectories and drive the rotor to rotate in different directions through a single-phase signal. The bidirectional motion of the SUSM can be realised by switching the two vibration modes and excitation methods. The motor is designed and the operating principle is analysed. The resonant frequencies of the two vibration modes are determined by the finite element simulated analysis, and the transient analysis is adopted to obtain the diagonal trajectories of the driving part. Finally, a prototype of the single-mode SUSM is developed and the mechanical performance of the prototype is measured and evaluated. According to the experimental results, the motor has a no-load speed of 265.37 rpm (B1 mode) and 320.20 rpm (B2 mode) in each direction under 200 Vp−p and 100 Vp−p voltage excitation, and the maximum load is 60 mN and 70 mN, respectively.
Performance characteristics of REBCO coated conductor joints fabricated by flux-free hybrid welding
Authors: Nisay Arman Ray , Shin Hyung-Seop 
Published: October 2023

Abstract
Recently, the joining of rare-earth barium copper oxide coated conductor (CC) tapes using ultrasonic welding (UW) has demonstrated outstanding potential in the in-line fabrication of longer tapes required for superconducting device applications. The UW method can produce CC joints by applying ultrasonic vibration in less than one second, and hybrid welding (HW) has been adopted to improve further the joint resistance (R
j) and electromechanical properties of the UW CC joints. However, conventional methods for preparing the HW and soldered CC joints involve applying solder flux to remove the oxide film, which can cause corrosion to the surface of the CC tapes and affect the joint’s lifespan during device operation. Therefore, this study aims to fabricate a robust HW CC joint of pre-solder insertion without solder flux and compare its joint strength and electromechanical properties with the traditional cases with the solder flux. While similar R
j can be obtained from both cases of HW CC joints, the flux-free HW CC joint has slightly higher joint strength and superior adhesive characteristics than those with flux. The difference in fracture mechanisms after lap-shear and T-peel tests between flux-free HW and with flux was extensively discussed. Additionally, the study investigates the correlation between a decrease in R
j with longer joint length in differently stabilized and processed CC tapes for flux-free HW. Overall, this study demonstrated that the flux-free HW method could efficiently produce robust CC joints with a lesser risk of corrosion and enhanced joint characteristics.
Co-optimization for hydrodynamic lubrication and leakage of V-shape textured bearings via linear weighting summation
Authors: Guo Juan , Ding Bo , Wang Yifei , Han Yanfeng 
Published: October 2023

Abstract
In this study, the linear weighting summation method is adopted for the co-optimization of V-shape textured bearings to maximize the load-carrying capacity and minimize the leakage and friction. Optimal parameters including texture angle and depth and ratio of the texture width are identified based on the established numerical model. Moreover, to improve the comprehensive performance, especially leakage reduction, two profile modifications are introduced: micro-slope and micro-step. The results show that the two proposed modifications are effective for improving the comprehensive performance of V-shape textured journal bearings, and optimal values exist for both the modifications. Furthermore, the overall performance of a bearing with micro-step modification is superior to that of a bearing with micro-slope modification, but the bearing with micro-slope modification is more sensitive to leakage. In summary, this study aims to provide theoretical foundation for the multi-objective optimization design of V-shape textured bearings.
Exploring the impact of kesterite charge transport layers on the photovoltaic properties of MAPbI3 perovskite solar cells
Authors: Noman Muhammad , Sherwani Tayyab , Tariq Jan Shayan , Ismail Muhammad 
Published: October 2023

Abstract
The pressing need for highly efficient renewable energy technologies has propelled research into perovskite solar cells (PSC) due to their excellent photovoltaic properties and high-performance potentials. This research investigates the performance and optimization of MAPbI3-based PSC, focusing on the use of different kesterite based hole transport layers (HTLs). Through a detailed analysis using SCAPs simulation software, the study explores the effects of charge transport layers, thickness, doping, defects, work function, and temperature on the solar cell’s performance, quantum efficiency, energy band alignment, absorption, electric field and recombination. The PSC design parameters were optimized to their highest potential. The best performance was demonstrated by ZnSe/MAPbI3/CBTS with PCE 21.01%. The research provides valuable insights into achieving highly efficient and stable photovoltaic technologies, contributing to the advancement of next-generation perovskite solar cells.
Study on wear, corrosion and fatigue properties of dual metallic bearings coated with nickel and aluminum particles
Authors: Esfahani Zahra , Sadooghi Ali , Rahmani Kaveh , Hashemi Seyed Jalal 
Published: October 2023

Abstract
One of the solutions for improving the mechanical properties is coating them with particles, which is carried out by various methods. In this study, dual metallic copper/steel bearings were investigated so that, one of them was an uncoated (S0) and three coated samples, nickel micro-particles (S1), nickel/aluminum micro-particles (S2), and nickel/aluminum nano-particles (S3) were produced. The samples were subjected to mechanical tests including micro hardness, wear, and scratch, and then their corrosion rate and fatigue life were evaluated. The results showed that creating a nano-sized coating on the sample improved their properties compared to the micro-sized and uncoated samples. The highest micro hardness was obtained for sample S3, which was equal to 103.6 HV, 18% higher than sample S0. The lowest wear and corrosion rates were also obtained for sample S3, which were equal to 0.38 mg m−1 and 3.14 mm year−1, respectively. Also, sample S3 had lowest delamination amount in the scratch test equal to 0.17 mm and most number of cycles until failure, 242 thousand cycles, in the fatigue test which was 76% more than the number of cycles spent on sample S0. Additionally, the microstructure of the corroded and worn surfaces of samples were examined by SEM imaging.
Ultra-thin metal-free terahertz absorber for electromagnetic shielding
Authors: Mandal Shankha Shuvra , Varshney Gaurav , Jagadeesh V K 
Published: October 2023

Abstract
An ultrathin broadband absorber covering the frequency range of 0.1 to 10 terahertz (THz) and

0.1

to

6.94

THz with more than 80% and 90% absorption, respectively is designed and numerically analysed. The absorber structure utilizes a partial reflecting surface and reflector of graphene separated by a thin dielectric spacer providing the metal-free structure. Multiple resonances are generated in the absorber structure whose spectrum can be separated or merged to find the narrow or broad absorption spectrum. The proposed absorber operates with the combine effect of the electromagnetic (EM) resonances occurring in the graphene resonator and the destructive interference taking place in the dielectric spacer. The absorber operation is validated through the theory of electromagnetic coupled mode resonances and with the theory of multiple reflections. The narrow absorption peaks can allow the proposed absorber to be utilized as refractive index sensor and the broad absorption spectrum can allow it to be utilized in the EM shielding and packaging applications.
Dark energy in light of the early JWST observations: case for a negative cosmological constant?
Authors: Adil Shahnawaz A. , Mukhopadhyay Upala , Sen Anjan A. , Vagnozzi Sunny 
Published: October 2023

AbstractEarly data from the James Webb Space Telescope (JWST) has uncovered the existence of a surprisingly abundant population of very massive galaxies at extremely high redshift, which are hard to accommodate within the standard ΛCDM cosmology. We explore whether the JWST observations may be pointing towards more complex dynamics in the dark energy (DE) sector. Motivated by the ubiquity of anti-de Sitter vacua in string theory, we consider a string-inspired scenario where the DE sector consists of a negative cosmological constant (nCC) and a evolving component with positive energy density on top, whose equation of state is allowed to cross the phantom divide. We show that such a scenario can drastically alter the growth of structure compared to ΛCDM, and accommodate the otherwise puzzling JWST observations if the dynamical component evolves from the quintessence-like regime in the past to the phantom regime today: in particular, we demonstrate that the presence of a nCC (which requires a higher density for the evolving component) plays a crucial role in enhancing the predicted cumulative comoving stellar mass density. Our work reinforces the enormous potential held by observations of the abundance of high-z galaxies in probing cosmological models and new fundamental physics, including string-inspired ingredients.
Mechanism of enhanced ion temperature by impurity seeding in EAST H-mode plasma
Authors: Yang Xiuda , Gong Xianzu , Qian Jinping , Jin Yifei , Manas Pierre , Li Pan , Bourdelle Clarisse , Chu Yuqi , Zhang Bin , Chen Yingjie , Hu Yunchan , Li Yingying , Li Kedong , Zhang Xuexi , Duan Yanmin , Zhang Hongming , Jia Tianqi , Liu Haiqing , Zang Qing , Huang Juan , Ding Rui , Wang Liang , Xu Guosheng 
Published: October 2023

Abstract
Ion temperature (T
i) profiles are commonly observed to increase in peaking, leading to higher central T
i, after impurity seeding in the EAST H-mode plasma. Argon can be more efficient at raising T
i than neon. Toroidal rotation can also be enhanced in scenarios with NBI heating. A more significant increase in toroidal rotation is brought about by seeding argon than seeding neon. Turbulence is experimentally observed to be suppressed. Extensive modeling using the quasilinear gyrokinetic code QuaLiKiz is performed to explain the above observations. It is found that the enhanced T
i can always be explained by the turbulence stabilization. However, the mechanism of turbulence stabilization is related to heating methods and the seeding impurity species. In the pure RF (ECRH + LHW) heating scenarios, where only the trapped electron mode (TEM) exists, argon can stabilize the TEM more significantly than neon due to its higher charge and heavier mass. In scenarios with increasing NBI power, the ion heat flux can be dominated by the ion temperature gradient (ITG), thus the enhanced T
i is mainly attributed to ITG stabilization. In these cases, except argon’s ability to more efficiently stabilize TEM, more evident increased toroidal rotation brought about by argon seeding can also be beneficial to stabilize turbulence.
The first observational evidence of a mixed Rossby–gravity wave contribution to triggering the onset process of the South China Sea summer monsoon
Authors: Hu Peng , Huangfu Jingliang , Chen Wen , Feng Tao , Wang Lin , Tang Yulian 
Published: October 2023

Abstract
Convectively coupled equatorial waves (Kelvin waves, equatorial Rossby waves, the Madden–Julian Oscillation, tropical depression–type waves, and mixed Rossby–gravity (MRG) waves) are important components of the tropical atmosphere. It is already known that the first four kinds of equatorial waves can trigger the onset of the South China Sea summer monsoon (SCSSM). This study provides observational evidence that an MRG wave contributes to triggering the onset process of the SCSSM in 2023, which took place very early (advanced by two weeks). Specifically, anomalous upper-tropospheric southerly winds first appeared in the equatorial central Pacific at the end of April. These southerly winds propagated westwards and downwards to the equatorial western Pacific and became an MRG wave. As this MRG wave continued to propagate westwards, the associated southwesterly winds contributed to the SCSSM onset. In addition to the MRG wave, the westerly phase of the Madden–Julian Oscillation is located around the Maritime Continent, which also creates a favorable environment for the SCSSM onset in 2023. After addressing the important role of the MRG wave, this study completes the last piece of the puzzle of the impacts of equatorial waves on the monsoon onset.
Two-dimensional integrable systems with position-dependent mass via complex holomorphic functions
Authors: Zhang Hai , Wu Kai , Wang Delong 
Published: October 2023

Abstract
We study the relationship between integrable systems with a position-dependent mass (PDM) and complex holomorphic functions and the potential applications of the latter to deduce the former. For a prescribed mass term the associated complex function is derived. The complex function and related plane transformation are used to generate the PDM systems of three integrable Hénon–Heiles systems and a Holt system as well. We also figure out a holomorphic function, which ensures separability of the corresponding PDM systems in the polar-like coordinates. The holomorphic function together with Jacobi method have yielded a variety of generalized separable systems. At last we put forward an example of a family of separable systems to show that not all PDM systems can be deduced through some holomorphic function.
3D-printed wearable BaTiO3/PDMS piezoelectric nanogenerator for self-powered body movement sensing
Authors: Shi Xiaoquan , Sun Yazhou , Tian Haiying , Liu Haitao , Li Dekai 
Published: October 2023

Abstract
Flexible piezoelectric nanogenerators (PENGs) used in body movement real-time monitoring are of great interest for their wide application potential such as in the field of smart healthcare. In this work, a self-powered BaTiO3/Polydimethylsiloxane (PDMS) PENG for body movement sensing was successfully fabricated by extrusion 3D printing. Matrix system composed of different ratios of PDMS was selected based on the rheological property of materials. Experimental investigations were conducted to examine the impact of printing pressure and speed on the linewidth. Subsequently, the extrusion parameters for nanogenerators were determined based on the printed linewidth. The composite showed good ferroelectric property. After polarization, the nanogenerators exhibited an improvement in output performance of up to 55.2%. Additionally, the device demonstrated a good linear relationship between voltage and tapped force test by an electromechanical vibrator. Successful detection of body or muscle movement signals was achieved when the nanogenerator was mounted on the human finger, throat, or foot using a wearable sock, highlighting its potential for applications in self-powered wearable devices for smart healthcare.
Interpretable surrogate models to approximate the predictions of convolutional neural networks in glaucoma diagnosis
Authors: Sigut Jose , Fumero Francisco , Arnay Rafael , Estévez José , Díaz-Alemán Tinguaro 
Published: October 2023

Abstract
Deep learning systems, especially in critical fields like medicine, suffer from a significant drawback, their black box nature, which lacks mechanisms for explaining or interpreting their decisions. In this regard, our research aims to evaluate the use of surrogate models for interpreting convolutional neural network (CNN) decisions in glaucoma diagnosis. Our approach is novel in that we approximate the original model with an interpretable one and also change the input features, replacing pixels with tabular geometric features of the optic disc, cup, and neuroretinal rim. We trained CNNs with two types of images: original images of the optic nerve head and simplified images showing only the disc and cup contours on a uniform background. Decision trees were used as surrogate models due to their simplicity and visualization properties, while saliency maps were calculated for some images for comparison. The experiments carried out with 1271 images of healthy subjects and 721 images of glaucomatous eyes demonstrate that decision trees can closely approximate the predictions of neural networks trained on simplified contour images, with R-squared values near 0.9 for VGG19, Resnet50, InceptionV3 and Xception architectures. Saliency maps proved difficult to interpret and showed inconsistent results across architectures, in contrast to the decision trees. Additionally, some decision trees trained as surrogate models outperformed a decision tree trained on the actual outcomes without surrogation. Decision trees may be a more interpretable alternative to saliency methods. Moreover, the fact that we matched the performance of a decision tree without surrogation to that obtained by decision trees using knowledge distillation from neural networks is a great advantage since decision trees are inherently interpretable. Therefore, based on our findings, we think this approach would be the most recommendable choice for specialists as a diagnostic tool.
Investigating community-based care service factors delaying residential care home admission of community dwelling older adults and cost consequence
Authors: Jeon Yun-Hee , Simpson Judy M , Comans Tracy , Shin Mirim , Fethney Judith , McKenzie Heather , Crawford Tonia , Lang Catherine , Inacio Maria 
Published: October 2023

Abstract

Objectives
To examine factors contributing to delaying care home admission; and compare the rates of care home admission and cost consequence between two government subsidised programmes, Veterans’ Affairs Community Nursing (VCN) and Home Care Package (HCP).

Methods
Our national, population-based retrospective cohort study and cost analysis used existing, de-identified veterans’ claims databases (2010–19) and the Registry of Senior Australians Historical Cohort (2010–17), plus aggregate programme expenditure data. This involved 21,636 VCN clients (20,980 aged 65–100 years), and an age- and sex-matched HCP cohort (N = 20,980).

Results
Service factors associated with lower risk of care home admission in the VCN cohort were periodic (versus continuous) service delivery (HR 0.27 [95%CI, 0.24–0.31] for ≤18 months; HR 0.89 [95%CI, 0.84–0.95] for &gt;18 months), and majority care delivered by registered nurses (versus personal care workers) (HR 0.86 [95%CI, 0.75–0.99] for ≤18 months; HR 0.91 [95%CI, 0.85–0.98] for &gt;18 months). In the matched cohorts, the time to care home admission for VCN clients (median 28 months, IQR 14–42) was higher than for HCP clients (14, IQR 6–27). Within 5 years of service access, 57.6% (95%CI, 56.9–58.4) of HCP clients and 26.6% (95%CI, 26.0–27.2) of VCN clients had care home admission. The estimated cost saving for VCN recipients compared to HCP recipients over 5 years for relevant government providers was over A$1 billion.

Conclusions
Compared to an HCP model, individuals receiving VCN services remained at home longer, with potentially significant cost savings. This new understanding suggests timely opportunity for many countries’ efforts to enhance community-based care services.
The simulation argument reconsidered
Authors: Harris Keith Raymond 
Published: October 2023

Abstract
Some philosophers regard it as a serious possibility that we now exist within a simulation. That this hypothesis is somewhat probable has been defended extensively by Nick Bostrom. Notably, Bostrom does not defend the conclusion that we inhabit a simulation, but rather the disjunctive conclusion that the human species is very likely to die out before reaching a ‘posthuman stage’, that posthuman civilizations are extremely unlikely to run significant numbers of simulations, or that we almost certainly inhabit a simulation. Bostrom argues that there is no basis for strongly favouring one of these alternatives over its counterparts. The upshot is that it is fairly probable that we inhabit a simulation. I argue that posthuman civilizations are likely to be unwilling to run significant numbers of simulations, thereby undermining the case for assigning a somewhat high probability to the hypothesis that we live in a simulation.