bluuebunny/crossref_metadata_2025_split huggingface dataset:
Defect-guided self-tearing in graphene
Authors: Li Fengwei , Kang Zhan , Li Ming 
Published: January 2024

Abstract
The two-dimensional to three-dimensional configuration transition through self-tearing promises the engineering and promising applications of graphene. However, it is challenging to control the tearing path on demand through common thermal and interfacial treatments. In this manuscript, a defect-guided self-tearing technique is proposed to generate wider, longer, and even curved and serrated configurations, which is impossible for defect-free graphene. The underlying tearing mechanisms regarding the advancing displacement are disclosed through molecular dynamics simulations and theoretical model. This study provides a useful guidance to the implementation of complex and functional three-dimensional graphene structures.
Rotating ring on a horizontal rod
Authors: Cross Rod 
Published: January 2024

Abstract
A simple experiment is described where a metal ring was spun by hand in a vertical plane on a horizontal rod. The ring rotated about one hundred times before it fell onto the rod. The physics of the problem involves rotation of the ring in a circular path around the rod, plus rotation of the ring at a lower frequency about its own axis. It is a slightly more challenging problem than the standard loop-the-loop demonstration.
A novel split-gate trench MOSFET embedded with a high-k pillar for higher breakdown voltage
Authors: Huang Li , Li Xiaojin , Sun Yabin , Shi Yanling 
Published: January 2024

Abstract
A novel split-gate trench MOSFET embedded with a high-k pillar (HKP SGT-MOS) is proposed in this study. Numerous electric displacement lines are allowed to enter the high-k pillar introduced beneath the split gate, thus relieving the crowding of the electric field at the bottom corner of the split gate. Therefore, the HKP SGT-MOS can achieve a higher breakdown voltage (BV) without sacrificing its forward conduction. Various dielectrics for the high-k pillar, such as SiO2, Si3N4, Al2O3 and HfO2, are investigated. The results reveal that HfO2 has the largest figure of merit (FOM) and BV. The characteristics of the HKP SGT-MOS have also been validated by the Technology Computer-Aided Design simulation, and the BV and (FOM = BV 2/R
on,sp) are 258.3 V and 37.46 MW cm−2, achieving 36.7% and 87.02% improvement compared to the conventional SGT-MOS (CSGT-MOS), and 18.4% and 38.59% improvement compared to the SGT-MOS with short split-gate (SSGT-MOS). Moreover, the influence of the drift doping concentration, the mesa width, the length of the drift region and the width of the split gate/high-k pillar are also studied to optimize the proposed HKP SGT-MOS.
Terahertz dielectric properties of Fe3O4 thin films deposited on Si (100) substrate
Authors: Khandelwal Ashish , Sharath Chandra L S , Sharma Shilpam , Sagdeo Archna , Choudhary R J , Chattopadhyay M K 
Published: January 2024

Abstract
Fe3O4 is considered to be a promising material for terahertz spintronic applications as well as for stealth technology. However, the optical properties of Fe3O4 in the thin film form at terahertz frequencies are not reported in literature. In this article, we present the frequency and temperature dependence of dielectric permittivity (ε
1) and optical conductivity (σ
1) of Fe3O4 films deposited on Si substrate. The σ
1 of these films show absorption peaks related to charge localization and shallow impurities. It is also observed that the Fe2O3/Fe3O4 composite films have large σ
1 and ε
1 indicating their potential use for stealth technology applications. The overall optical properties are found to depend strongly on the microstructure and defects, such as, the grain size and the presence of grain boundaries, anti-phase boundaries, strain disorder due to lattice mismatch and/or the Fe+2/Fe+3 ratio.
Fast and accurate electromagnetic modeling of non-insulated and metal-insulated REBCO magnets
Authors: Pardo Enric , Fazilleau Philippe 
Published: January 2024

Abstract
REBCO high-temperature superconductors are promising for all-superconducting high-field magnets, including ultra-high field magnets. Non-insulated (NI) and metal-insulated (MI) windings are a good solution for protection against electro-thermal quench. Design and optimization requires numerical modelling of REBCO inserts for high-field magnets. Here, we detail a fast and accurate two-dimensional cross-sectional model for the electromagnetic response of NI and MI coils, which is based on the minimum electro magnetic entropy production. Benchmarking with an A − V formulation method on a double pancake coil shows good agreement. We also analyse a fully superconducting 32 T magnet with a REBCO insert and a low-temperature superconducing outsert. In particular, we analyse the current density, the screening current induced field (SCIF), and the AC loss. We have shown that metal-insulated coils enable transfer of angular current in the radial direction, and hence magnet protection, while keeping the same screening currents and AC loss of insulated coils, even at relatively high ramp rates of 1 A s−1. Surprisingly, soldered coils with low resistance between turns present relatively low AC loss for over-current configuration, which might enable higher generated magnetic fields. The numerical method presented here can be applied to optimize high-field magnets regarding SCIF in MI or NI magnets. It also serves as the basis for future electro-thermal modelling and multi-physics modelling that also includes mechanical properties.
Fractional approach to evolution of the magnetic field lines near the magnetic null points
Authors: Durmaz Hasan , Özdemir Zehra , Sekerci Yadigar 
Published: January 2024

Abstract
In this work, the magnetic reconnection model near null points in 3D space will be investigated using fractional calculations in the 3D magnetohydrodynamic framework. For the initial magnetic configuration (without external currents), we reformulated the numerically solved boundary initial value problem using fractional calculations. We studied the 3D Magnetic reconnection states and the behavior of the magnetic field around the null point and the null line. We also analyzed the fractional significance of charged particle motions in Killing magnetic fields. Moreover, the obtained results were visualized, and a comparison was made between the results obtained from integer and fractional calculations.
AuNP decorated aegle marmelos leaf as SERS substrate for trace detection of antibiotics and machine learning based classification
Authors: Sarma Dipjyoti , Marak Macduf R , Chetia Indrani , Badwaik Laxmikant S , Nath Pabitra 
Published: January 2024

Abstract
Surface-enhanced Raman spectroscopy (SERS) has emerged as a reliable molecular spectroscopic technique for trace detection of chemical and biological samples. Present study illustrates a new SERS platform which has been obtained through surface adsorption of gold nanoparticles (AuNP) on a microscopically roughened surface of aegle marmelos (AM) leaf. The micro-structured patterns of the AM leaves promote the generation of hotspot regions for the surface deposited AuNPs thus, aids in electromagnetic enhancement for the scattered Raman signals from the sample. For the proposed SERS platform, with rhodamine6G (R6G) as an analyte, the limit of detection (LoD) was found to be 0.88 nM. The applicability of the designed SERS was realized through detection and quantification of two commonly used antibiotics- Ceftriaxone (CEFTR) and Ceftiofur sodium (CEF-Na) residues from cow milk samples. Furthermore, a dimensionality reduction method known as principal component analysis (PCA) and an optimal machine learning-based model were built to categorize the analytes in the milk samples. The suggested machine learning model’s classification accuracy was found to be 94%.
Mathematical formulae for neutron self-shielding properties of media in an isotropic neutron field
Authors: Elmaghraby Elsayed K , Mahmoud Ateia W , Salama E , Elghazaly A , El-fiki S A 
Published: January 2024

Abstract
In the current study, an ab initio derivation of the neutron self-shielding factor to solve the complex neutron transport problem of the decrease of the neutron flux as it penetrates into a material placed in an isotropic neutron field having equal flux in all directions. The theory of steady-state neutron transport was employed, starting from Stuart’s formula, to derive simple analytical formulae based on the integral cross-section parameters. The formulae could be adopted by the user according to various variables, such as the neutron flux distribution and geometry of the simulation at hand. The concluded formulae of the self-shielding factors comprise an inverted sigmoid function normalized with a weight representing the ratio between the macroscopic total and scattering cross-sections of the medium. The general convex volume geometries are reduced to a set of chord lengths, while the neutron interaction probabilities within the volume are parameterized to the epithermal and thermal neutron energies. The arguments of the inverted-sigmoid function were derived from a simplified version of neutron transport formulation. The derived analytic formulae agreed greatly with the experimental observations for different elements and geometries.
Photodegradation of methylene blue dye using graphene oxide incorporated, post-transition metal doped zinc oxide thin films by spray pyrolysis
Authors: Paul John , Dhivyaprasath K , Ashok M , Kumar M C Santhosh 
Published: January 2024

Abstract
Photocatalytic activity of graphene oxide incorporated pure and metal doped zinc oxide thin films were studied against methylene blue dye under simulated solar irradiation. Thin films were deposited on a glass substrate using an automated spray pyrolysis technique at a temperature of 425 °C. Aluminium, gallium, and indium were the post-transition metals used for doping. Graphene oxide content in the precursor solution was fixed at 0.00375 g/l. The formation of the wurtzite structure of zinc oxide has been confirmed using structural analysis. The average crystallite size of all the thin film samples was found to be in the range of 45–55 nm. The morphology and elemental composition of the films were studied using scanning electron microscopy and energy-dispersive x-ray spectroscopy. The energy band gap of the material was determined from UV–vis-NIR spectroscopic measurements using Tauc’s plot and it is in the range of 3.25–3.28 eV. Photoluminescence spectra of the as-deposited films were recorded. Intensity of the near band emission at 395 nm was found to decrease upon metal doping, indicating a better photocatalytic property. All the films were used for heterogeneous photocatalysis and the indium doped zinc oxide thin film incorporated with graphene oxide was found to be a better catalyst with an efficiency of 94.9% for degrading methylene blue dye in 180 min.
Energy gap measurements based on enhanced absorption coefficient calculation from transmittance and reflectance raw data
Authors: Allaham Mohammad , Dallaev Rashid , Burda Daniel , Sobola Dinara , Nebojsa Alois , Knápek Alexandr , Mousa Marwan S , Kolařík Vladimír 
Published: January 2024

Abstract
The absorption coefficient plays an important role in studying and characterizing semiconducting materials. It is an important parameter to study the mechanism of photons absorption within the structure of the studied material. Thus, it helps to study the several types of charge carrier transport along with the energy band structure and its defects. In literature, a formula was reported to precisely calculate the absorption coefficient from raw data of transmittance and reflectance of electromagnetic radiation. However, the reported formula has several issues limiting its validity in the literature. In this paper, we provide a more mathematically accurate form of this equation to precisely obtain the absorption coefficient from the raw data, by considering the total internal reflection at the different interfaces. Moreover, the equation is tested by simulated data and is applied to study the optical characteristics of a single-component epoxy resin from its transmittance and reflectance raw data.
Carrier density distribution in AlGaAs/GaAs superlattices with different numbers of quantum wells determined by capacitance-voltage profiling
Authors: Vasilkova E I , Pirogov E V , Sobolev M S , Baranov A I , Gudovskikh A S , Khabibullin R A , Bouravleuv A D 
Published: January 2024

Abstract
The charge carrier density distribution in uniformly doped AlGaAs/GaAs superlattices with layer thicknesses of 1.5/10 nm and different numbers of quantum wells was studied. Both energy band theory and capacitance–voltage profiling were used to determine the carrier concentration profiles of the structures. During the analysis of the experimental and simulated capacitance–voltage characteristics, it was found that the maximum electron concentrations increase with an increase in the number of quantum wells from ∼

7.1
⋅

10

16

cm

−
3

for three wells to ∼

9.3
⋅

10

16

cm

−
3

for 25 wells with an overall superlattice doping level of ∼

10

17

cm

−
3

.
Comparison of partial and deep energy detachment behaviors with Ar seeding on EAST new corner slot divertor
Authors: Li Kedong , Wang Rong , Yang Zhongshi , Wu Kai , He Tao , Jia Guozhang , Lin Xin , Meng Lingyi , Yu Lin , Zhang Bin , Wu Jinhua , Duan Yanmin , Mao Songtao , Zang Qing , Zhang Ling , Zhang Tao , Wang Fudi , Wang Shouxin , Yuan Qiping , Wang Liang , Luo Guang-Nan 
Published: January 2024

Abstract
It is necessary for future fusion reactor to reduce the heat fluxes on the entire divertor target, especially if view of long pulse high performance operation. In recent EAST experiments, partial energy detachment without confinement degradation, and deep energy detachment with protection of the entire divertor target have both been confirmed on EAST corner slot divertor by argon (Ar) seeding, which can provide reference for the divertor protection on future fusion reactors. In the deep energy detachment state, the electron temperature T
et along entire lower outer divertor target decreases to less than 10 eV and heat fluxes are also strongly mitigated with peak heat flux reduction of more than 90%. Compared to the attached state, there is a moderate confinement degradation with H
98,y2 from ∼1 to ∼0.9 because of Ar radiation in the core region. This confinement degradation can be avoided in the partial energy detachment state, where the radiative power losses in the core are reduced. The experiment and SOLPS-ITER simulation results show that there is no decrease of particle flux js
on the divertor target in the partial energy detachment state because the momentum loss in the SOL region is not strong enough. With increasing Ar seeding, there is a js
decrease in the deep energy detachment state. The increases of momentum and power losses in the SOL region, and the decrease of upstream pressure all contribute to the js
reduction.
Modeling of frequency-sweeping Alfvén modes in the TJ-II stellarator
Authors: Ghiozzi A.G. , Mantsinen M.J. , Pastells P. , Spong D.A. , Melnikov A.V. , Eliseev L.G. , Sharapov S.E. 
Published: January 2024

Abstract
Alfvénic activity has been observed in the TJ-II stellarator which resembles the frequency sweeping demonstrated by Alfvén cascade modes in tokamaks. A numerical validation study was conducted using a reduced magnetohydrodynamic (MHD) model to show that such modes could only have been observed in discharges where the rotational transform profile was non-monotonic. During experiments, coil current was varied which resulted in shifting of the minimum value of the rotational transform profile. To mimic this effect, we study the Alfvénic activity predicted by the reduced MHD model for a set of input rotational transform profiles with varying minima. A mode is found whose toroidal and poloidal mode numbers match those predicted in experiments which sweeps downward/upward in frequency as the minimum value of the rotational transform profile is increased/decreased. The results serve as a demonstration of the validity and utility of MHD spectroscopy.
Enhancement of ECCD by the current condensation effect for stabilizing large magnetic islands caused by neoclassical tearing modes in tokamak plasmas
Authors: Liu Tong , Wang Zheng-Xiong , Wei Lai , Wang Jialei , Reiman Allan 
Published: January 2024

Abstract
The radio frequency current condensation effect reported in Reiman and Fisch (2018 Phys. Rev. Lett.
121 225001) is modeled in the nonlinear resistive magnetohydrodynamic code. A series of numerical investigations have been performed to investigate the enhancement of electron cyclotron current drive (ECCD) by the current condensation effect during the control of neoclassical tearing mode (NTM) in tokamak plasmas. In the numerical model, both the parallel transport and the perpendicular transport of electron temperature are considered. The EC driven current and driven perturbed electron temperature can nonlinearly evolve within the given magnetic configuration and eventually reach saturation states. The input power threshold of ECCD and the fold bifurcation phenomenon are numerically verified via nonlinear simulations. The numerical results show good agreements with the analytical results. Moreover, spatial distributions of EC current for the two solutions at different condensed level are displayed. The control effectiveness of ECCD for large NTM islands has been evaluated while considering the current condensation effect. While taking into account current condensation effect, for a sufficiently large input power, a larger island can be more effectively stabilized than a smaller one, which suggests a reassessment of the previous idea that the ECCD should always be turned on as early as possible. The potential physics mechanism behind the ECCD control have all been discussed in detail. Furthermore, the condensation effect is found to have favorable effects on the radial misalignment of ECCD. In the consideration of the situation for extremely localized control needs, a highly peaked heating profile is adopted to verify that the fold bifurcation phenomenon still exists and the current condensation effect can still take effect in this extreme condition.
Third order nonlinearity examined by pulsed and CW lasers: an organic urea barbituric acid (UBA) single crystal for optical limiting application with DFT study
Authors: Suresh A , Jauhar RO MU , Girisun T C Sabari , Manikandan N , Vinitha G 
Published: January 2024

Abstract
Bulk size of urea barbituric acid single crystal which has not been reported earlier was successfully grown by slow evaporation solution growth method. Single-crystal XRD brought out the lattice constant and the crystal system is observed to be monoclinic with space group P. Functional group of UBA were determined by FT-IR. UBA crystal is entirely visible from 270 to 900 nm with linear optical energy gap value to be 4.50 eV. The observed HOMO–LUMO energy gap was 5.21 eV. Thermally, UBA crystal is found to be stable up to 184˚°C. The Cp value of UBA increases from 1.21 to 1.58 J g−1K−1 with the temperature difference from 30 to 100˚°C. UBA shows good photoconductive nature and it found to be positive and Laser Damage Threshold (LDT) value of UBA crystal is 0.97 GW cm−2. Hardness testing confirms that UBA crystal belongs to soft nature category. Dielectric properties of UBA crystal are studied as a function of frequency and temperature. Third order NLO properties of the UBA crystal were studied under CW and pulsed lasers (ns) regimes using Z-scan technique. Good Optical limiting (OL) response (2.2860 х 1012 W/m2) confirms the efficiency of UBA crystal to be used as optical limiters for protection towards short pulse lasers.
QPI assay of fibroblasts resilience to adverse effects of nanoGO clusters by multimodal and multiscale microscopy
Authors: Valentino Marika , Pirone Daniele , Béhal Jaromir , Mugnano Martina , Castaldo Rachele , Lama Giuseppe C , Memmolo Pasquale , Miccio Lisa , Bianco Vittorio , Grilli Simonetta , Ferraro Pietro 
Published: January 2024

Abstract
Graphene is considered a possible drug deliver in nanomedicine for its mechanical, physical and chemical characteristics. Thus, studying graphene biocompatibility is pivotal to contribute to the modern nano-therapy science. The coexistence between cells and graphene should be analysed using non-invasive technologies and thus quantitative phase imaging (QPI) modalities are suitable to investigate the morphometric evolution of cells under nanomaterial exposure. Here, we show how a multimodal QPI approach can furnish a noninvasive analysis for probing the dose-dependent effect of nanoGO clusters on adherent NIH 3T3 fibroblast cells. We rely on both digital holography and Fourier ptychography (FP) in transmission microscopy mode. The former allows accurate time-lapse experiments at the single cell level. The latter provides a wide field of view characterization at the cells network level, thus assuring a significant statistical measurement by exploiting the intrinsic large space-bandwidth product of FP. The combination of these two techniques allows one to extract multimodal information about the cell resilience to adverse effects of nanoGO in the surrounding buffer, namely through quantitative, multi-scale, and time-resolved characterization.
Measurement of ultrashort laser pulses with a time-dependent polarization state using the d-scan technique
Authors: Díaz Rivas Daniel , Raab Ann-Kathrin , Guo Chen , Viotti Anne-Lise , Sytcevich Ivan , L’Huillier Anne , Arnold Cord 
Published: January 2024

Abstract
The dispersion scan (d-scan) technique is extended to measurement of the time-dependent polarization state of ultrashort laser pulses. In the simplest implementation for linearly polarized ultrashort pulses, the d-scan technique records the second harmonic generation spectrum as a function of a known spectral phase manipulation. By applying this method to two orthogonally polarized projections of an arbitrary polarized electric field and by measuring the spectrum at an intermediate angle, we can reconstruct the evolution over time of the polarization state. We demonstrate the method by measuring a polarization gate generated from

6

f
s

pulses with a combination of waveplates. The measurements are compared to simulations, showing an excellent agreement.
Rotating magnetocaloric effect in polycrystals—harnessing the demagnetizing effect
Authors: Almeida R , Freitas S C , Fernandes C R , Kiefe R , Araújo J P , Amaral J S , Ventura J O , Belo J H , Silva D J 
Published: January 2024

Abstract
Climate change and the increasing demand for energy globally have motivated the search for a more sustainable heat-pumping technology. Magnetic refrigeration stands as one of the most promising alternative technologies for clean and efficient heat pumps of the future. The rotating magnetocaloric effect (RMCE) has previously been studied in materials with magnetocrystalline anisotropy due to its potential to improve devices by requiring only a single magnetic field region, but these materials are fragile and costly to obtain, making them inviable for applications. It has been shown that by exploiting the demagnetizing effect, an RMCE is, in fact, attainable in any polycrystalline magnetocaloric sample with an asymmetric shape, without requiring magnetocrystalline anisotropy. Using gadolinium as a case study, we provide a theoretical framework for computing the demagnetizing field-based RMCE and present thorough experimental verification for different magnetic field intensities and a wide temperature range. Direct measurements of the RMCE in gadolinium reveal that a significant adiabatic temperature difference (1.2 K) and refrigerant capacity (7.44 J kg−1) can be attained within low magnetic field amplitudes (0.4 T). Utilizing lower magnetic field intensities in a magnetocaloric heat pump can significantly diminish the need for permanent magnet materials, thus reducing the overall device cost, size, and weight, ultimately enhancing the feasibility of mass-producing such devices.