bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysing the shape memory behaviour of GnP-enhanced nanocomposites: a comparative study between experimental and finite element analysis
Authors: Gupta Ritesh , Mittal Gaurav , Kumar Krishna , Pandel Upender 
Published: May 2024

Abstract
Shape memory polymers (SMPs) are capable of enduring significant deformations and returning to their original form upon activation by certain external stimuli. However, their restricted mechanical and thermal capabilities have limited their broader application in engineering fields. To address this, the integration of graphene nanoplatelets (GnPs) with SMPs has proven effective in enhancing their mechanical and thermal properties while maintaining inherent shape memory functions. The study evaluated shape memory nanocomposites (SMNCs) using dynamic mechanical, thermogravimetric, and static tensile, flexural, and shape memory tests, along with scanning electron microscopy to analyse tensile fractures. The results indicate that the optimal content of GnP is 0.6 wt%, resulting in excellent shape memory, thermal, and mechanical properties. Specifically, this composition demonstrates a shape recovery ratio of 94.02%, a storage modulus of 4580.07 MPa, a tensile strength of 61.42 MPa, and a flexural strength of 116.37 MPa. Additionally, the incorporation of GnPs into epoxy reduces recovery times by up to 52% at the 0.6 wt% concentration. While there is a slight decrease in the shape fixity ratio from 98.77% to 93.02%, the shape recoverability remains consistently high across all samples. Current finite element (FE) models often necessitate complex, problem-specific user subroutines, which can impede the straightforward application of research findings in real-world settings. To address this, the current study introduces an innovative finite element simulation method using the widely used ABAQUS software to model the thermomechanical behaviour of SMNCs, importantly incorporating the time-dependent viscoelastic behaviour of the material. The effectiveness of this new approach was tested by comparing experimental results from bending test of SMNCs cantilever beam with outcomes derived from FE simulations. The strong agreement between the experimental data and simulation results confirmed the precision and reliability of this novel technique.
Piezoresistive sensitivity enhancement below threshold voltage in sub-5 nm node using junctionless multi-nanosheet FETs
Authors: Kumar Nitish , Joshi Khanjan , Gupta Ankur , Singh Pushpapraj 
Published: May 2024

Abstract
In this paper, the piezoresistive sensitivity is enhanced by applying uniform mechanical stress (MS) on the multi-nanosheet (NS) channels of sub-5 nm junctionless field-effect transistors. The piezoresistivity of the sensing device is boosted by narrowing channel conductivity using low gate biasing and reducing physical channel width, resulting in the maximum (∼6 times higher) sensitivity observed in the subthreshold regime compared to the ON-state condition. In addition, the sensitivity is extensively increased by ∼30.3% near the threshold voltage with horizontally multi-NS stacking due to the uniform MS distribution on the multi-NS channels, which can sense slight deflection of pressure on the circular diaphragm. These results show that the tunable sensitivity of junctionless multi-channel devices is superior to the inversion mode, a consequence of the less scattering effect, better thermal stability, and low electronic noise.
A synapse with low power consumption based on MoTe2/SnS2 heterostructure
Authors: He Wenxin , Xing Yanhui , Fang Peijing , Han Zisuo , Yu Zhipeng , Zhan Rongbin , Han Jun , Guan Baolu , Zhang Baoshun , Lv Weiming , Zeng Zhongming 
Published: May 2024

Abstract
The use of two-dimensional materials and van der Waals heterostructures holds great potential for improving the performance of memristors Here, we present SnS2/MoTe2 heterostructure synaptic transistors. Benefiting from the ultra-low dark current of the heterojunction, the power consumption of the synapse is only 19 pJ per switching under 0.1 V bias, comparable to that of biological synapses. The synaptic device based on the SnS2/MoTe2 demonstrates various synaptic functionalities, including short-term plasticity, long-term plasticity, and paired-pulse facilitation. In particular, the synaptic weight of the excitatory postsynaptic current can reach 109.8%. In addition, the controllability of the long-term potentiation and long-term depression are discussed. The dynamic range (G
max/G
min) and the symmetricity values of the synaptic devices are approximately 16.22 and 6.37, and the non-linearity is 1.79. Our study provides the possibility for the application of 2D material synaptic devices in the field of low-power information storage.
Development and characterization of self-powered, highly sensitive optoelectronic device based on PVA-rGO nanofibers/n-Si
Authors: Yıldırım Fatma , Galehdarvand Sharmineh , Chenari Hossein Mahmoudi , Yılmaz Mehmet , Aydoğan Şakir 
Published: May 2024

Abstract
This study provided a promising way to fabricate low-cost and high-performance Poly (vinyl alcohol)-reduced graphene oxide (PVA-RGO) nanofibers/n-Si heterojunction photodetector. For this purpose, the hybrid heterojunction with a very-high rectification ratio (2.4 × 106) was achieved by successfully coating PVA-RGO nanofibers on n-Si wafer by electrospinning method. When the electro-optical analysis of the fabricated heterojunction photodetector under visible light depending on the light intensity, ultraviolet (UV) and infrared (IR) lights was examined in detail, it was observed that the photodetector exhibited both self-powered behavior and very high photo-response under each light sources. However, the highest optical performance was obtained under UV (365 nm) originated from PVA-RGO layer and IR (850 nm) light from both interfacial states between PVA-RGO nanofibers and Si and from Si layer. Under 365 nm UV light, the maximum performance values of R, D, ON/OFF ratio, normalized photo-dark-current ratio and external quantum efficiency (%) were obtained as 688 mA W−1, 1.15 × 1015Jones, 2.49 × 106, 8.28 × 1010 W−1 and 234%, respectively.
Effect of sandblasting and acid surface pretreatment on the specific capacitance of CuO nanostructures grown by hot water treatment for supercapacitor electrode applications
Authors: Haque Shanzida , Wang Daoyuan , Ergul Busra , Basurrah Assem , Karabacak Tansel 
Published: May 2024

Abstract
Crystalline copper oxide (CuO) nanostructures with micro, nano, and micro-nano surface roughness were grown on Cu sheet substrates by a facile, scalable, low-cost, and low-temperature hot water treatment (HWT) method that simply involved immersing Cu sheet in DI water at 75 °C for 24 h without any chemical additives. Various morphological features and sizes of CuO nanostructures were tuned by using different surface pretreatment techniques including acid treatment, sandblasting, or a combination of those two. The surface morphology of the prepared samples was analyzed by scanning electron microscopy. The crystal structure of the CuO nanostructures was investigated by x-ray diffraction XRD and Raman spectroscopy. To study the pseudocapacitive behavior, their potential supercapacitor performance, and equivalent series resistance, electrochemical analysis was done by cyclic voltammetry and electrochemical impedance spectroscopy for all the CuO/Cu samples in 1 M of Na2SO4 electrolyte. Among all, the best supercapacitive performance was achieved for CuO/Cu samples pretreated with Sandblasting followed by Acid treatment resulting in a specific capacitance of about 104 F g−1. The electrode with the sandblasted + acid pretreated sample showed a maximum of ∼69% capacitive retention after 2000 consecutive cycles. Our results indicate that CuO nanostructures on Cu substrates prepared with different surface pretreatment conditions and grown by HWT can be promising electrodes for supercapacitor device applications.
Feasibility and optimization of 19F MRI on a clinical 3T with a large field-of-view torso coil
Authors: Lechuga Lawrence M , Cho Monica M , Vail David M , Captini Christian M , Fain Sean B , Begovatz Paul 
Published: May 2024

Abstract

Objective. The objective of this work is to: (1) demonstrate fluorine-19 (19F) MRI on a 3T clinical system with a large field of view (FOV) multi-channel torso coil (2) demonstrate an example parameter selection optimization for a 19F agent to maximize the signal-to-noise ratio (SNR)-efficiency for spoiled gradient echo (SPGR), balanced steady-state free precession (bSSFP), and phase-cycled bSSFP (bSSFP-C), and (3) validate detection feasibility in ex vivo tissues. Approach. Measurements were conducted on a 3.0T Discovery MR750w MRI (GE Healthcare, USA) with an 8-channel 1H/19F torso coil (MRI Tools, Germany). Numerical simulations were conducted for perfluoropolyether to determine the theoretical parameters to maximize SNR-efficiency for the sequences. Theoretical parameters were experimentally verified, and the sensitivity of the sequences was compared with a 10 min acquisition time with a 3.125 × 3.125 × 3 mm3 in-plane resolution. Feasibility of a bSSFP-C was also demonstrated in phantom and ex vivo tissues. Main Results. Flip angles (FAs) of 12 and 64° maximized the signal for SPGR and bSSFP, and validation of optimal FA and receiver bandwidth showed close agreement with numerical simulations. Sensitivities of 2.47, 5.81, and 4.44

m

s

−
0.5

m

M

−
1

and empirical detection limits of 20.3, 1.5, and 6.2 mM were achieved for SPGR, bSSFP, and bSSFP-C, respectively. bSSFP and bSSFP-C achieved 1.8-fold greater sensitivity over SPGR (p < 0.01). Significance. bSSFP-C was able to improve sensitivity relative to simple SPGR and reduce both bSSFP banding effects and imaging time. The sequence was used to demonstrate the feasibility of 19F MRI at clinical FOVs and field strengths within ex-vivo tissues.
Automatic breast ultrasound (ABUS) tumor segmentation based on global and local feature fusion
Authors: Li Yanfeng , Ren Yihan , Cheng Zhanyi , Sun Jia , Pan Pan , Chen Houjin 
Published: May 2024

Abstract
Accurate segmentation of tumor regions in automated breast ultrasound (ABUS) images is of paramount importance in computer-aided diagnosis system. However, the inherent diversity of tumors and the imaging interference pose great challenges to ABUS tumor segmentation. In this paper, we propose a global and local feature interaction model combined with graph fusion (GLGM), for 3D ABUS tumor segmentation. In GLGM, we construct a dual branch encoder-decoder, where both local and global features can be extracted. Besides, a global and local feature fusion module is designed, which employs the deepest semantic interaction to facilitate information exchange between local and global features. Additionally, to improve the segmentation performance for small tumors, a graph convolution-based shallow feature fusion module is designed. It exploits the shallow feature to enhance the feature expression of small tumors in both local and global domains. The proposed method is evaluated on a private ABUS dataset and a public ABUS dataset. For the private ABUS dataset, the small tumors (volume smaller than 1 cm3) account for over 50% of the entire dataset. Experimental results show that the proposed GLGM model outperforms several state-of-the-art segmentation models in 3D ABUS tumor segmentation, particularly in segmenting small tumors.
Physical insights from the aspect ratio dependence of turbulence in negative triangularity plasmas
Authors: Balestri A , Ball J , Coda S , Cruz-Zabala D J , Garcia-Munoz M , Viezzer E 
Published: May 2024

Abstract
In this work, we study the impact of aspect ratio

A
=

R
0

/

r

(the ratio of major radius R
0 to minor radius r) on the confinement benefits of negative triangularity (NT) plasma shaping. We use high-fidelity flux tube gyrokinetic GENE simulations and consider several different scenarios: four of them inspired by TCV experimental data, a scenario inspired by DIII-D experimental data and a scenario expected in the new SMART spherical tokamak. The present study reveals a distinct and non-trivial dependence. NT improves confinement at any value of A for ITG turbulence, while for TEM turbulence confinement is improved only in the case of large and conventional aspect ratios. Additionally, through a detailed study of a large aspect ratio case with pure ITG drive, we develop an intuitive physical picture that explains the beneficial effect of NT at large and conventional aspect ratios. This picture does not hold in TEM-dominated regimes, where a complex synergistic effect of many factors is found. Finally, we performed the first linear gyrokinetic simulations of SMART, finding that both NT and PT scenarios are dominated by micro-tearing-mode (MTM) turbulence and that NT is more susceptible to MTMs at tight aspect ratio. However, a regime where ITG dominates can be found in SMART, and in this regime NT is more linearly stable.
Dynamics of switching optical soliton in fiber with sixth order dispersion and inter modal dispersion
Authors: Parasuraman E , Muniyappan A , Ravichandran R 
Published: May 2024

Abstract
This work pertains to the study of switching soliton in fiber for nonlinear Schrödinger (NLS) equation with the presence of higher order dispersion and inter modal dispersion (IMD). The nonlinear wave in the optical fiber are described by the NLS equation which having the second order, fourth order, fifth order, sixth order dispersion, higher order nonlinearity and IMD. The main goal of the paper is to examine the sixth order dispersion on nonlinear wave in the fiber with the conditions of IMD. Hence, we employ the Bäcklund transformation of the Riccati equation (BTRE) approach to NLS equation and obtain the soliton solution. By the use of soliton solution along with graphical snapshots, we provide the conditions for forming switching solition in optical fiber and also analyze the effect of sixth order dispersion in fiber. The stability of the solution of NLS equation is also addressed.
Two-dimensional intrinsic ferromagnetic materials of Janus 2H-NbXY (X, Y = S, Se and Te, X ≠ Y) monolayers with high Curie temperature and large magnetic anisotropy
Authors: Wang Tianxing , Tian Tian , Li Mengxin , Zhao Xu , Xia Congxin , An Yipeng , Wei Shuyi 
Published: May 2024

Abstract
Two-dimensional (2D) intrinsic ferromagnetic materials with large magnetic anisotropy (MA) and high Curie temperature (TC) are desirable for low-dimensional spintronic applications. In this work, a highly stable Janus NbXY (X, Y = S, Se and Te, X ≠ Y) monolayers with intrinsic ferromagnetism is investigated by using first-principles calculations. The results demonstrate that the MAE values of the NbSSe, NbSTe and NbSeTe MLs are as high as −2.185 meV, −4.013 meV and −4.495 meV per unit cell, respectively, which is higher than the previously reported 2D intrinsic ferromagnetic materials such as FeBrI, NiI2, and VSSe MLs etc. And they are still large enough for practical applications. The Curie temperature (Tc) is estimated to be 160 K for NbSSe monolayer, 260 K for NbSTe monolayer, and 200 K for NbSeTe monolayer based on Monte Carlo simulation. The MAE and Tc could be effectively controlled and enhanced by the biaxial strains. The MAE of NbSSe, NbSTe and NbSeTe MLs can be increased by 8.7%, 24.9% and 14.1%, and reach up to −2.375, −5.015 and −5.131 meV at 5% compressive strain, respectively. Remarkably, at 5% tensile strain, the room temperature

T

c

of 300 K can be reached for NbSTe monolayer, which is rather promising for its practical application. The large magnetic anisotropy energy and controllable Curie temperature make the NbXY monolayers a promising candidate for applications in spintronic devices at the nanoscale and in high-density data storage.
Q-switched pulse generation in L-band region with polyacrylonitrile saturable absorber
Authors: Ahmad Aeriyn D , Salam Sameer , Mokhtar Norrima , Arof Hamzah , Apsari Retna , Hamida Belal Ahmed , Harun Sulaiman W 
Published: May 2024

Abstract
In this study, we assess the practicality of using Polyacrylonitrile (PAN) as a saturable absorber (SA) for generating Q-switched pulses within an erbium-doped fibre laser (EDFL) cavity. A successful combination of PAN, a resin material, and polyvinyl alcohol resulted in the formation of a SA film. This film was utilised to generate stable Q-switched pulses operating in a long-wavelength band of 1572 nm. The greatest repetition rate achieved was 66.1 kHz, while the minimum pulse width was 2.43 μs. The maximum pulse energy was achieved at 52 nJ and measured at a pump power of 175.9 mW. To the best of our knowledge, this study is the first report of EDFL passive Q-switching employing a PAN absorber.
The state of the dark energy equation of state circa 2023
Authors: Escamilla Luis A. , Giarè William , Valentino Eleonora Di , Nunes Rafael C. , Vagnozzi Sunny 
Published: May 2024

AbstractWe critically examine the state of current constraints on the dark energy (DE) equation of state (EoS)w. Our study is motivated by the observation that, while broadly consistent with the cosmological constant valuew= -1, several independent probes appear to point towards a slightly phantom EoS (w∼ -1.03) which, if confirmed, could have important implications for the Hubble tension. We pay attention to the apparent preference for phantom DE fromPlanckCosmic Microwave Background (CMB) data alone, whose origin we study in detail and attribute to a wide range of (physical and geometrical) effects. We deem the combination ofPlanckCMB, Baryon Acoustic Oscillations, Type Ia Supernovae, and Cosmic Chronometers data to be particularly trustworthy, inferring from this final consensus datasetw= -1.013+0.038-0.043, in excellent agreement with the cosmological constant value. Overall, despite a few scattered hints, we find no compelling evidence forcing us away from the cosmological constant (yet).
Primordial origin of supermassive black holes from axion bubbles
Authors: Kasai Kentaro , Kawasaki Masahiro , Kitajima Naoya , Murai Kai , Neda Shunsuke , Takahashi Fuminobu 
Published: May 2024

Abstract
We study a modification of the primordial black hole (PBH) formation model from axion bubbles.
We assume that the Peccei-Quinn scalar rolls down in the radial direction from a large field value to the potential minimum during inflation, which suppresses the axion fluctuations and weakens the clustering of PBHs on large scales.
We find that the modified model can produce a sufficient number of PBHs that seed the supermassive black holes while avoiding the observational constraints from isocurvature perturbations and angular correlation of the high-redshift quasars.
A study on vector mediator top-philic dark matter
Authors: Hu Yanyan , Liu Yandong , Liu Yuanyuan 
Published: May 2024

Abstract
We conducted a study on a simplified dark matter model that introduces a vector-like intermediate particle, facilitating exclusive interactions between dark matter and the top quark in the Standard Model. The analysis focused on the relic density of Dirac-type fermion dark matter and highlighted the complementary role of direct detection in constraining the dark matter model. Notably, in instances when dark matter mass is small, the tree-level two-body annihilation process experiences suppression. In such scenarios, the contributions of the three-body process (

χ

χ

¯

→
t

b

¯

W

−

) and the one-loop process (

χ

χ

¯

→
gg

) dominate the relic abundance. With regard to direct detection, calculations were performed for the two-loop contribution to the dark-matter–gluon interaction, yielding the corresponding spin-independent scattering cross section.
An approximate Kerr–Newman-like metric endowed with a magnetic dipole and mass quadrupole
Authors: Frutos-Alfaro Francisco 
Published: May 2024

Abstract
Approximate all-terrain spacetimes for astrophysical applications are presented. The metrics possess five relativistic multipole moments, namely, mass, rotation, mass quadrupole, charge, and magnetic dipole moment. All these spacetimes approximately satisfy the Einstein–Maxwell field equations. The first metric is generated using the Hoenselaers–Perjés method from given relativistic multipoles. The second metric is a perturbation of the Kerr–Newman metric, which makes it a relevant approximation for astrophysical calculations. The last metric is an extension of the Hartle–Thorne metric that is important for obtaining internal models of compact objects perturbatively. The electromagnetic field is calculated using Cartan forms for locally non-rotating observers. These spacetimes are relevant for inferring properties of compact objects from astrophysical observations. Furthermore, the numerical implementations of these metrics are straightforward, making them versatile for simulating potential astrophysical applications.
Observational appearances of hairy black holes in the framework of gravitational decoupling
Authors: Liang Yizhi , Lyu Xin , Tao Jun 
Published: May 2024

Abstract
We investigate the observational appearance of static and spherically symmetric hairy black holes in the framework of gravitational decoupling with the weak energy condition (WEC). Two types of thin illumination conditions are studied: spherical accretion and disk accretion. As the hairy parameter increases, the size of the photon sphere and photon rings in both models decreases, and the overall luminosity attenuation becomes more pronounced. In spherical accretion, the luminosity of infalling accretion is significantly lower than that of stationary accretion. In disk accretion the luminosity of the black hole is contributed by direct emission, the lensing ring and the photon ring. Employing four types of astrophysical disk luminosity model, we investigate the appearance of halos and note that their luminosities do not superimpose when the source is on or beyond the innermost stable circular orbit.
The tightness of the measure-based method to estimate quantum coherence
Authors: Zhang Zimeng , Li Yongming , Luo Yu 
Published: May 2024

Abstract
With the advancement of quantum information science, the understanding of quantum coherence has become increasingly important. In this paper, we investigate the effects of different channels on quantum states and analyze the evolution process of quantum states during channel transmission. Our findings reveal variations in the impact of different channels on quantum coherence. Additionally, we explore the estimation of lower bounds on coherence after passing through these diverse channels. We observe that channel transmission has a certain influence on the tightness of lower bounds on quantum coherence. We conduct a detailed analysis of this influence and propose improvement method to enhance the tightness of the lower bound estimation. Based on our research results, we draw conclusions that unveil the characteristics of quantum coherence under different channel conditions. Furthermore, we provide an effective estimation method and improvement strategies to accurately assess the coherence of quantum states. This research holds significant implications for further advancements in quantum information processing and quantum communication.