bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of artificial intelligence on human loss in decision making, laziness and safety in education
Authors: Ahmad Sayed Fayaz , Han Heesup , Alam Muhammad Mansoor , Rehmat Mohd. Khairul , Irshad Muhammad , Arraño-Muñoz Marcelo , Ariza-Montes Antonio
Published: June 2023

This study examines the impact of artificial intelligence (AI) on loss in decision-making, laziness, and privacy concerns among university students in Pakistan and China. Like other sectors, education also adopts AI technologies to address modern-day challenges. AI investment will grow to USD 253.82 million from 2021 to 2025. However, worryingly, researchers and institutions across the globe are praising the positive role of AI but ignoring its concerns. This study is based on qualitative methodology using PLS-Smart for the data analysis. Primary data was collected from 285 students from different universities in Pakistan and China. The purposive Sampling technique was used to draw the sample from the population. The data analysis findings show that AI significantly impacts the loss of human decision-making and makes humans lazy. It also impacts security and privacy. The findings show that 68.9% of laziness in humans, 68.6% in personal privacy and security issues, and 27.7% in the loss of decision-making are due to the impact of artificial intelligence in Pakistani and Chinese society. From this, it was observed that human laziness is the most affected area due to AI. However, this study argues that significant preventive measures are necessary before implementing AI technology in education. Accepting AI without addressing the major human concerns would be like summoning the devils. Concentrating on justified designing and deploying and using AI for education is recommended to address the issue.
Increasing the scan speed in high resolution, low energy electron diffraction measurements by presetting the gate time
Authors: Kny Anna J. , Sokolowski Moritz , Kury Peter
Published: June 2023

We report on a speed-up data acquisition routine for recording intensities in reciprocal space (k-space) with increased scan speed by a single point detector. It is designed for recording low energy electron diffraction (LEED) data with high resolution by a spot profile analysis LEED instrument. It counteracts the problem of long acquisition times that are encountered when larger areas in the reciprocal space are scanned. It exploits the fact that in typical LEED images of ordered surfaces, more than 90% of the data points in k-space belong to the low-intense background, which is often not of interest. Only about 10% of the data points are related to the relevant diffraction features, namely, the LEED spots. Often it is not necessary to measure the background with the same statistical significance as measuring those points that contain information. The data points belonging to the LEED spots can be discriminated from those of the background by their higher intensities. An acquisition routine that sets an increased gate time for the counting in response to higher intensities thus safeguards good statistics for data points of the LEED spots and saves measurement time when recording data points of the background with small gate times. For typical LEED images, a reduction of the total acquisition time by a factor of about 10 is obtained. We give examples of one- and two-dimensional scans from current experiments, recorded with and without the speed-up routine. We further discuss how the routine supports the measurement of energy dependent reciprocal space maps.
Experimental verification of magnetic near-field channeling using a helical-shaped wire medium lens
Authors: Morgado Tiago A. , João Guilherme L. , Pereira Ricardo A. M. , Fernandes David E. , Lannebère Sylvain
Published: June 2023

We experimentally verify that a magnetic uniaxial wire medium lens consisting of a racemic array of helical-shaped metallic wires may enable channeling the normal component of the magnetic field of near-field sources with resolution well below the diffraction limit over a broad bandwidth. It is experimentally demonstrated that the helical-shaped wire medium lens can be regarded as the magnetic counterpart of the usual wire medium lenses formed by straight metallic wires. The experimental results are validated with full-wave numerical simulations. We envision that the proposed metamaterial lens may have potential applications in magnetic resonance imaging, near-field wireless power transfer, and sensing.
On the importance of three-dimensional modeling for high-energy-density physics experiments
Authors: Sauppe J. P. , Lu Y. , Tzeferacos P. , Reyes A. C. , Palaniyappan S. , Flippo K. A. , Li S. , Kline J. L.
Published: June 2023

Laser-driven cylindrical implosion experiments enable direct measurements of hydrodynamic instability growth in convergent geometries, providing a wealth of validation data in the high-energy-density regime. These experiments are designed to be nearly axially invariant, allowing for modeling with complementary two-dimensional slices of the cylinder. Two distinct hydrodynamics codes are employed to model a subset of these experiments, and the results are shown to be in very good agreement with each other and the available experimental data. While this 2D modeling approach adequately captures most of the physics of the implosion and ensuing instability growth, there are crucial aspects from the three-dimensional nature of the experiments that are missed in 2D. The first fully 3D simulations of these experiments are presented, and small but significant differences are found to arise from both the axial and azimuthal non-uniformity in the laser drive. Recent experimental results confirming the drive asymmetry are discussed.
Hafnium oxide: A thin film dielectric with controllable etch resistance for semiconductor device fabrication
Authors: Wratten A. , Walker D. , Khorani E. , Healy B. F. M. , Grant N. E. , Murphy J. D.
Published: June 2023

Thin film dielectrics are ubiquitous in the manufacture of electronic devices and are frequently deposited and etched away at various stages of device fabrication. We demonstrate that hafnium oxide (HfO2) thin films grown via atomic layer deposition on silicon and silicon pre-coated with aluminum oxide (Al2O3) have etch resistance properties, which can be tuned simply by changing the post-deposition annealing temperature. The etching rates of films in hydrofluoric acid (HF) solutions were found to be dependent on annealing temperature, with the etch rate decreasing with increasing temperature. A transition region in the etch rate was identified between 300 and 350 °C, corresponding to the crystallization of the HfO2 films, as identified via x-ray diffraction. HfO2 films deposited directly onto silicon annealed above 350 °C were resistant to 10% HF solutions over the course of several hours. In the case of Si/Al2O3/HfO2 stacks, closer inspection reveals the existence of channels, which reduces the etch resistance of HF acid, as evidenced by tetramethylammonium hydroxide etching of the silicon substrate. Crystallized HfO2 can be used to protect other dielectrics in device processing, and we demonstrate its use in single-sided fabrication of patterned structures of Al2O3, which can control the effective charge-carrier lifetime in silicon wafers for use in modulating THz and mm-wave radiation.
Scale-invariant resonance characteristics in magnetized capacitive radio frequency plasmas
Authors: Yang Dong , Wang Huihui , Zheng Bocong , Zou Xiaobing , Wang Xinxin , Fu Yangyang
Published: June 2023

Resonance mechanisms have been found to be essential for the generation of high-density rf plasmas at low pressures, in which electrons can be continuously accelerated through multiple interactions with the oscillating rf sheaths. In this work, we report the scale-invariant resonance mechanisms, such as bounce resonance heating and plasma series resonance, in low-pressure capacitive rf plasmas in the presence of an external magnetic field. The generation conditions for the resonance mechanisms are determined via fully kinetic simulations. It is found that the resonance dynamical properties of single-frequency plasmas (e.g., a double-peak electron density vs magnetic field curve) can be exactly replicated at different scales when three combined control parameters, i.e., the reduced gap distance pd (pressure × distance), reduced driving frequency f/p (frequency divided by pressure), and reduced magnetic field B/p (magnetic field divided by pressure), are kept constant. The similarity relations for the electron density and electron power absorption in magnetized rf plasmas are numerically confirmed. Furthermore, the similarity and scale-invariant resonance characteristics are elucidated through the scaling of the Boltzmann equation with collisional terms for weakly ionized rf plasmas with a magnetic field, which is proven to be theoretically exact.
Dual-phase digital lock-in implementation based on Nyquist rate and sampling subtraction
Authors: Ricobom B. , Nardi M. , Bonfim M.
Published: June 2023

Lock-in amplifiers (LIA) are widely used in laboratory environments to detect low-amplitude signals buried in noise as well as real and imaginary parts of a complex quantity. They are based on the technique of synchronous detection, where the signal of interest is modulated into a desired frequency, sent to the medium or device to be analyzed, and captured by a detector. The detector scheme relies on the concept of phase-sensitive detection, generally resulting in two components: in-phase and quadrature. This article shows a very simple and low computational-cost way to implement a dual-phase LIA, using readily available microcontrollers, running a simple and fast algorithm. Three examples of signal detection are presented (sound wave signal, impedance meter, and weak signal recovery) to point out the flexibility and capabilities of the proposed methodology.
Enhancing the ultrasonic waveguide sensor’s fluid level sensitivity using through-transmission and pulse-echo techniques simultaneously
Authors: Kumar Abhishek , Periyannan Suresh
Published: June 2023

This paper reports an ultrasonic waveguide technique using U-shaped configurations to measure the fluid level. The longitudinal L(0,1) wave mode was propagated in the waveguide using through-transmission (TT) and pulse-echo (PE) techniques simultaneously using a single shear transducer. Initially, we used the Finite Element Method (FEM) to study the waveguide's wave propagation behavior while immersed in various fluids. Develop the level sensor using the waveguide’s first and second pass signals, corresponding to TT and PE. We have performed the level measurement experiments based on the drop in amplitude and change in time of flight of the received sensor signals. Studied the sensor’s sensitivity using TT1, PE1, TT2, and PE2 signals (1 and 2 represent first and second pass signals, respectively) with different fluid levels (petrol, water, castor oil, and glycerin). A comparison study was performed between straight waveguides using PE and U-shaped waveguides using TT techniques to find the limitations of waveguide sensors. During level-sensing experiments, the average error for U-shaped and straight waveguides was identified as 3.5% and 5.6%, respectively. We studied signal attenuation from straight and U-shaped waveguide sensors based on the sensor surface and dead-end region. In the designed U-shape waveguide, only the wave leakage effect was considered, avoiding the dead-end reflection during the immersion of the sensor in liquid and allowing for more fluid depth measurements. In addition, the U-shaped waveguide was further used for fluid-level sensing using three wave modes [L(0,1), T(0,1), and F(1,1)] simultaneously. This sensor can monitor fluid levels in hostile environments and inaccessible regions of power plants, oil, and petrochemical industries.
On the galloping cross-flow vibration responses of three in-line square cylinders
Authors: Behara Suresh , Ravikanth B. , Chandra Venu
Published: June 2023

Galloping cross-flow vibration responses of three in-line identical square cylinders are numerically studied for the mass ratio m*=2, streamwise gaps Lx=3B and 5B, reduced velocity U*=3−50, and Reynolds numbers Re = 150 in two dimensions (2-D) and 2000, where the flow is three-dimensional (3-D). Here, B is the side of the cylinder. An isolated cylinder does not gallop since the mass ratio m*=2 is less than the critical value in the Re = 150 flow, whereas for the three in-line bodies, galloping instability is triggered at the upstream cylinder due to the interference effect caused by the presence of downstream bodies. The interaction with the wake of galloping upstream cylinder promotes galloping instability for the two downstream cylinders almost immediately at Re = 150. In the three-dimensional wake at Re = 2000, downstream cylinders interact with less coherent Karman vortices shed by the galloping upstream cylinder, compared to the 2-D case. This phenomenon leads to the delayed on-set of galloping response for the first downstream cylinder, while the second one never gallops.
Parameter estimation for the reaction–diffusion master equation
Authors: Barrows Dexter , Ilie Silvana
Published: June 2023

In this paper, we present a novel method to estimate chemical reaction and diffusion rates for biochemical reaction–diffusion dynamics from a time series of observations. Our approach leverages iterated particle filtering as a means to fit a high-dimensional stochastic and discrete spatiotemporal model to sparse time series data, often with some chemical species present in low copy numbers. We demonstrate the feasibility of this approach on three realistic reaction–diffusion systems. In each case, the method recovered known true values for all rate parameters with a great degree of accuracy.
Decomposition of the wall-heat flux of compressible boundary layers
Authors: Ricco Pierre , Duan Lian
Published: June 2023

We use the method developed by Elnahhas and Johnson [“On the enhancement of boundary layer skin friction by turbulence: An angular momentum approach,” J. Fluid Mech. 940, A36 (2022)] and Xu et al. [“Decomposition of the skin-friction coefficient of compressible boundary layers,” Phys. Fluids 35, 035107 (2023)] for the decomposition of the skin-friction coefficient to integrate the mean temperature equation for high-Reynolds-number compressible boundary layers and arrive at an identity for the decomposition of the wall-heat flux. The physical interpretation of the identity and the limitations of this approach are discussed. We perform an integration on the mean temperature equation to obtain an identity that is the heat-transfer analog to the compressible von Kármán momentum integral equation for the skin-friction coefficient. This identity is applied to numerical data for laminar and turbulent compressible boundary layers, revealing that the mean-flow dissipation and production of turbulent kinetic energy given by the Favre–Reynolds stresses dominate the thermal-energy balance. The term related to the growth of the turbulent boundary layer opposes the wall cooling. Other identities for the wall-heat flux, inspired by the method of Fukagata et al. [“Contribution of Reynolds stress distribution to the skin friction in wall-bounded flows,” Phys. Fluids 14(11), L73–L76 (2002)], are studied numerically and by asymptotic methods. The terms of these identities depend spuriously on the upper integration bound because this bound is a mathematical quantity used in the derivation. When the bound is asymptotically large, the integral identities simplify to the heat-transfer analog to the von Kármán momentum equation. We also prove that an existing multiple-integration identity reduces to the definition of the wall-heat flux when the number of integrations is asymptotically large. No information about the wall-heat transfer is extracted because the impact of the integration number is nonphysical.
High sensitivity multiscale and multitasking terahertz Janus sensor based on photonic spin Hall effect
Authors: Sui Jun-Yang , Zou Jia-Hao , Liao Si-Yuan , Li Bing-Xiang , Zhang Hai-Feng
Published: June 2023

Photonic spin Hall effect (PSHE) is an effective metrological tool to characterize the variation in weak refractive index (RI) and nanostructure parameters. In this Letter, a highly sensitive terahertz Janus sensor (JS) based on PSHE is proposed. Through the asymmetric arrangement of different dielectrics, the sensor has a Janus feature, realizing the multitasking of thickness and RI detection on multiple scales. When electromagnetic waves (EWs) are incident into the JS from the forward scale, the number of graphene layers (1–7 layers) can be exactly identified by thickness detection. Enhancing the PSHE by the property of graphene, the JS can extend the thickness change of the graphene layer at the nanometer level by 106 times to the millimeter level with a sensitivity of 3.02 × 10−3 m/nm. In the case of EWs backward scale propagation, based on the sensitivity of 6.244 × 10−3 m/RIU, the JS can identify different kinds of waterborne bacterium such as Vibrio cholerae, Escherichia coli, and Shigella flexneri, in the RI range of 1.355–1.43 with high precision. The design of the multiscale and multitasking JS with high sensitivity is of great significance for accelerating the research and exploration of graphene materials. In addition, it provides an idea for real-time, no-label, and low-cost detection in the biomedical field.
Swirl driven solute mixing in narrow cylindrical channel
Authors: Kumar Dhananjay , Gaikwad Harshad Sanjay , Kaushik P , Mondal Pranab Kumar
Published: June 2023

We investigate the mixing of constituent components transported through a narrow fluidic cylindrical channel in a swirling flow environment. We solve for the flow field analytically using the separation of variables method under the framework of fully developed axial velocity and no-slip condition at fluid–solid interface and validate the same with numerical solution. The swirl velocity profile, which is a function of Reynolds number (Re), exhibits exponential decay along the length of the fluidic channel. We numerically solve the species transport equation for the Peclet number in the range of 102 to 104 coupled with the swirl velocity obtained for 0.1≤Re≤100, by using our in-house developed code essentially for the concentration distribution in the field. As seen, an increase in the Reynolds number results in complete rotation of fluids in the pathway, which, in turn, forms an engulfment flow (onset of chaotic convection) and enhances the underlying mixing efficiency substantially. The results show that inlet swirl promotes advection dominated mixing, while the dominance of advection increases substantially for the higher Reynolds number. We show that adding a small magnitude of swirl velocity at the inlet significantly reduces the channel length required for complete mixing even after the swirl velocity has decayed completely.
Modification of BCZT piezoelectric ceramics by modulating oxygen vacancies in different sintering atmospheres
Authors: Liu Chang , Mao Runyu , Wu Qiyun , Li Jianlin , Zheng Deyi , Fei Zihao , Pang Chi
Published: June 2023

In this work, we regulated the oxygen vacancy concentration by sintering BCZT + 0.1 mol % Y + 0.1 mol % Nb [BCZT-0.1 mol % (Y + Nb)] ceramics under air, oxygen, argon, and vacuum atmospheres and examined the effect of oxygen vacancy concentration on phase composition, crystal structure, microstructure, and electrical properties. X-ray photoelectron spectrometry and X-ray diffraction Rietveld refinement showed that the air- and oxygen-sintered ceramic samples had lower oxygen vacancy concentrations, and the oxygen octahedral lattice distortion in the samples was stable when the R-O-T phases coexisted, forming a multiphase coexistence structure with more spontaneous polarization directions. The oxygen-sintering atmosphere is important in oxygen compensation, which promotes the formation of dense microstructure, thereby increasing the Curie temperature (TC). Oxygen vacancy formation energy was low in the argon and vacuum atmospheres, and some oxygen vacancies increased the mass transfer effect and grain growth. Nevertheless, excess oxygen vacancies increased the leakage current during polarization resulting in poor polarity, which prevents directional deflection of domains and degrades performance. The vacuum-sintered sample was calcined in 1000 °C air for oxygen supplementation sintering, and as the sintering time increased, the oxygen vacancy concentration decreased, the grains grew further, the density increased, and the piezoelectric properties improved. The oxygen-sintered BCZT-0.1 mol % (Y + Nb) samples had good comprehensive electrical properties (d33 = 547 pC/N, kp = 55%, εr = 5355, Pr = 10.63 µC/cm2, EC = 1.89 kV/cm, tan δ = 0.02, and TC = 102 °C).
Piloting the rapid R-MEET framework at a coastal Ramsar Site
Authors: Munguía S. M. , Heinen J. T.
Published: June 2023

Context The Ramsar Convention on Wetlands is critical to conserving wetlands. However, it has received much criticism, particularly about the inadequacy of reporting by Contracting Parties. Aim We previously developed a rapid assessment tool called the Rapid Ramsar Management Effectiveness Evaluation Tool (Rapid R-MEET) to alleviate the reporting burden and emphasise the Convention’s priorities. Methods In this paper, we pilot this tool in the Caroni Swamp Ramsar Site in Trinidad. We also conduct a policy-gap analysis to understand the context in which management decisions are being made. Key results We found serious gaps in management capacity and a complex institutional context in which wetland decision-making takes place that undermine the successful implementation of the Ramsar Convention in the twin island nation. Conclusions These limitations have created a system of Ramsar Sites with minimal monitoring, research, and enforcement to achieve the Convention’s goals, particularly crippling reporting on ecological character. Implications Better coordination among agencies involved in wetland management, as well as more robust resourcing for management, is needed to achieve wetland conservation goals at the national and site levels. We also found that the Rapid R-MEET can be completed efficiently and effectively by external researchers, providing an avenue to increase collaboration, support under-resourced management teams, and improve reporting to the Convention.
Showing where you stand
Authors: Vandenitte Sébastien
Published: June 2023

Enactment is a frequent depictive strategy used to denote referents. Its referential functions are increasingly
well-documented cross-linguistically, notably in sign languages. A lesser-known function of enactment is that of stance
expression. By enacting a referent, language users can also convey their own perspective and comment on the enacted individual. In
this article, it is argued that the depictive manipulation of the French Belgian Sign Language (LSFB) lexical sign ls,
which refers to the action of signing, is a fruitful area of investigation for the study of social meanings conveyed by means of
enactment. The observation of elicited dyadic conversations about language attitudes shows that LSFB signers can mold several
formational aspects of the sign ls in a variety of ways by means of enactment, providing a near first-hand experience
of – and commenting on – diverse signers and their signing styles.
Put another way
Authors: Meurant Laurence
Published: June 2023

Reformulation involves saying something again in a different way. Because of its metalinguistic nature (Rabatel 2017), combined with its general aim of clarifying the utterance, we propose to
consider the act of reformulation as offering a window to the way interlocutors process and adjust themselves and their utterances
in their social language practices. More specifically, this study proposes a set of four analytical criteria to characterize
interlocutors’ investment in discourse and interaction via the observation of their use of reformulations. These criteria concern
the frequency of reformulations within a production, the proportion of self- and other-reformulations (Güllich and Kotschi 1987), the type of adjustment that the act of reformulation seeks to achieve
(Authier-Revuz 1995) and the type of semiotic strategies used, namely descriptive, indicative and depictive ways of meaning making
(Clark 1996; Ferrara and Hodge 2018).
The paper draws on the exploratory analysis of the productions of deaf LSFB signers extracted from the LSFB Corpus. It illustrates
how describing the reformulations according to the proposed criteria, reveals distinctions between different patterns of
pragmatic attitude and involvement in discourse and interaction. This approach opens new avenues for the pragmatic descriptions of
LSFB and signed discourses in general.
Foreign accent in L1 (first language)
Authors: Han Jeong-Im , Kim Joo-Yeon , Tsukada Kimiko
Published: June 2023

This study builds on Flege et al. (2006) and evaluated the influence of
chronological age and length of residence in North America on degree of foreign accent in first language (L1) Korean by Korean
adults and children in immigrant settings. The adult (A4/6) and child (C4/6) immigrants lived in the host countries for 4 or 6
years, respectively. Their Korean utterances were compared to those of age-matched controls in Seoul, Korea. The purpose was to
examine the cross-linguistic influence of English on the degree of foreign accent in L1 Korean by the immigrants. Eighteen
native-speaking judges rated four Korean utterances for overall degree of perceived foreign accent. Both adult and child
immigrants were more strongly foreign accented than the controls. However, (1) stability of L1 Korean was greater (less
foreign-accented) for the adult than child immigrants; and (2) there was no significant difference between the A4 and A6, and C4
and C6 groups. This suggests that by the time the Korean immigrants lived in North America for four years, they have diverged
audibly from the predominantly monolingual speakers in Seoul. The results have implications for L1 maintenance/attrition and
plasticity in spoken language processing.
Further observations on the definition of global hyperbolicity under low regularity
Authors: Minguzzi E
Published: June 2023

The definitions of global hyperbolicity for closed cone structures and topological preordered spaces are known to coincide. In this work we clarify the connection with definitions of global hyperbolicity proposed in recent literature on Lorentzian length spaces and Lorentzian optimal transport, suggesting possible corrections for the terminology adopted in these works. It is found that in Kunzinger–Sämann’s Lorentzian length spaces the definition of global hyperbolicity coincides with that valid for closed cone structures and, more generally, for topological preordered spaces: the causal relation is a closed order and the causally convex hull operation preserves compactness. In particular, it is independent of the metric, chronological relation or Lorentzian distance.
Black hole minimum size and scalar charge in shift-symmetric theories
Authors: Thaalba Farid , Antoniou Georgios , Sotiriou Thomas P
Published: June 2023

It is known that, for shift-symmetric scalars, only a linear coupling with the Gauss–Bonnet (GB) invariant can introduce black hole hair. Such hairy black holes have a minimum mass, determined by the coupling of this interaction, and a scalar charge that is uniquely determined by their mass and spin for a fixed value of that coupling. Here we explore how additional shift-symmetric interactions affect the structure of the black hole, the value of the minimum mass, and the scalar charge.
Optical solitons in curved spacetime
Authors: Spengler Felix , Belenchia Alessio , Rätzel Dennis , Braun Daniel
Published: June 2023

Light propagation in curved spacetime is at the basis of some of the most stringent tests of Einstein’s general relativity. At the same time, light propagation in media is at the basis of several communication systems. Given the ubiquity of the gravitational field, and the exquisite level of sensitivity of optical measurements, the time is ripe for investigations combining these two aspects and studying light propagation in media located in curved spacetime. In this work, we focus on the effect of a weak gravitational field on the propagation of optical solitons in non-linear optical media. We derive a non-linear Schrödinger equation describing the propagation of an optical pulse in an effective, gradient-index medium in flat spacetime, encoding both the material properties and curved spacetime effects. In analyzing the special case of propagation in a 1D optical fiber, we also include the effect of mechanical deformations and show it to be the dominant effect for a fiber oriented in the radial direction in Schwarzschild spacetime.
Noncommutative Hamiltonian formalism for noncommutative gravity
*
Authors: Castellani Leonardo
Published: June 2023

We present a covariant canonical formalism for noncommutative (NC) gravity, and in general for NC geometric theories defined via a twisted

⋆

-wedge product between forms. Noether theorems are generalized to the NC setting, and gauge generators are constructed in a twisted phase space with

⋆

-deformed Poisson bracket. This formalism is applied to NC d = 4 vierbein gravity, and allows to find the canonical generators of the tangent space

⋆

-gauge group.
Strategies to reduce the thermoelastic loss of multimaterial coated finite substrates
Authors: Zhou R , Molina-Ruiz M , Hellman F
Published: June 2023

Thermoelastic loss is an important energy dissipation mechanisms in resonant systems. A careful analysis of the thermoelastic loss is critical to the design of low-noise devices for high-precision applications, such as the mirrors used for gravitational-wave (GW) detectors. In this paper, we present analytical solutions to the thermoelastic loss due to thermoelasticity between different materials that are in contact. We find expressions for the thermoelastic loss of multimaterial coatings of finite substrates, and analyze its dependencies on material properties, mirror design and operating experimental conditions. Our results show that lower operating mirror temperature, thinner layers and higher number of interfaces in the coating, and the choice of the first layer of the coating that minimizes the thermal expansion mismatch with the substrate are strategies that reduce the thermoelastic loss and, therefore, diminish the thermal noise that limits the resolution in sensing applications. The results presented in this paper are relevant for the development of low-noise GW detectors and for other experiments sensitive to energy dissipation mechanisms when different materials are in contact.
Advanced materials for triboelectric nanogenerator
Authors: Li Chang-Heng , Ma Xinyu , Fu Jingjing , Sun Yuexuan , Wang Feipeng , Huang Zhengyong , Li Jian
Published: June 2023

Due to the advantages of excellent output power, low cost and easily preparation, triboelectric nanogenerator (TENG) is developing rapidly in the field of renewable energy. The output performance of TENG is largely dependent on the surface charge density, which is closely related to the ability of the tribo-material to gain or lose electrons. To obtain higher output power, numerous efforts have been done on material modifications of the friction layer and electrodes of TENG with additional fillers or molecular modifications. In this review, advanced materials for the preparation of TENG devices to achieve high output, humidity-resisting and wear-resisting performance are presented and the working mechanisms of performance optimisation are discussed. Moreover, natural materials, recyclable materials and non-conventional electrode materials are mentioned to inspire subsequent research on TENG.
Magnetization reversal modes and coercive field dependence on perpendicular magnetic anisotropy in FePt thin films
Authors: Román A , Lopez Pedroso A , Bouzehouane K , Gómez J E , Butera A , Aguirre M H , Soares M Medeiros , Garcia C , Steren L B
Published: June 2023

The competition between shape and perpendicular magnetic anisotropies in magnetic thin films gives rise to unusual magnetic behaviors. In ferromagnetic thin films, the presence of an out-of-plane component of the magnetic anisotropy may induce a transition from planar to stripe-like magnetic domains above a critical thickness,

t

c

. In this article, we present a detailed study of the magnetization switching mechanism in FePt thin films, where this phenomenon is observed. Using micromagnetic simulations and experiments, we found that below

t

c

the reversal mechanism is well described by the two-phase model while above this thickness the magnetization within each stripe reverses by coherent rotation. We also analyzed the out-of-plane component of the magnetic anisotropy and its temperature dependence, probing that substrate-induced strains are responsible for the abnormal coercive field behavior observed for FePt films with

t
>

t

c

.
Characterization of crack on the outer edge of the disk based on blade tip timing technology
Authors: Zhang Fanyu , Guo Shuaiping , Li Xuejun , Han Qingkai , Ma Jiaojiao , Zhang Hongxian
Published: June 2023

The structural performance failure of the rotating blade disk with disk crack is one of the major causes of aero-engine failures and even serious accidents. The blade tip timing (BTT) is a non-contact measurement technology that obtains the rotor operation status by detecting the blade. This paper has proposed a crack characterization method for the disk’s outer edge based on the BTT technique. In this process, the influence of crack state parameters (length and position) on the circumferential displacement signal of the blade tip is determined by using the crack tip displacement, the relative position of the blade tip motion during the rotation of the outer edge crack-containing disk and the actual blade tip measuring points, and the critical value of the crack state parameters affecting the blade tip offset is analyzed. The finite element simulation results verify the effectiveness and accuracy of the proposed method. The study of this article can provide a theoretical basis for the measurement of cracks on the disk’s outer edge by the BTT technique, which is of great significance for the accurate identification of the operating condition of the rotating blade disk structure.
Continuum limit for the Ablowitz–Ladik system
Authors: Killip Rowan , Ouyang Zhimeng , Visan Monica , Wu Lei
Published: June 2023

We show that solutions to the Ablowitz–Ladik system converge to solutions of the cubic nonlinear Schrödinger equation for merely L
2 initial data. Furthermore, we consider initial data for this lattice model that excites Fourier modes near both critical points of the discrete dispersion relation and demonstrate convergence to a decoupled system of nonlinear Schrödinger equations.
A simple experiment to study the array theorem using Fraunhofer diffraction of a two-dimensional grating
Authors: Singh Mamraj
Published: June 2023

A transmission electron microscopy (TEM) grid comprises an array of identical square apertures. In this study, the Fraunhofer diffraction pattern of a TEM grid was obtained by a 532 nm wavelength diode laser. It was compared with the Fraunhofer diffraction pattern computed by using the array theorem and employed to estimate the mesh size of the TEM grid.
Magnetohydrodynamics simulation of magnetic flux rope formation in a quadrupolar magnetic field configuration
Authors: Kumar Sanjay , Prasad Avijeet , Nayak Sushree S , Agarwal Satyam , Bhattacharyya R
Published: June 2023

Magnetic flux ropes (MFRs) play an important role in high-energetic events like solar flares and coronal mass ejections in the solar atmosphere. Importantly, solar observations suggest an association of some flaring events with quadrupolar magnetic configurations. However, the formation and subsequent evolution of MFRs in such magnetic configurations still need to be fully understood. In this paper, we present idealized magnetohydrodynamics (MHD) simulations of MFR formation in a quadrupolar magnetic configuration. A suitable initial magnetic field having a quadrupolar configuration is constructed by modifying a three-dimensional linear force-free magnetic field. The initial magnetic field contains neutral lines, which consist of X-type null points. The simulated dynamics initially demonstrate the oppositely directed magnetic field lines located across the polarity inversion lines (PILs) moving towards each other, resulting in magnetic reconnections. Due to these reconnections, four highly twisted MFRs form over the PILs. With time, the foot points of the MFRs move towards the X-type neutral lines and reconnect, generating complex magnetic structures around the neutral lines, thus making the MFR topology more complex in the quadrupolar configuration than those formed in bipolar loop systems. Further evolution reveals the non-uniform rise of the MFRs. Importantly, the simulations indicate that the pre-existing X-type null points in magnetic configurations can be crucial to the evolution of the MFRs and may lead to the observed brightenings during the onset of some flaring events in the quadrupolar configurations.
Three-dimensional structure and stability of discontinuities between unmagnetized pair plasma and magnetized electron-proton plasma
Authors: Dieckmann M E , Folini D , Falk M , Bock A , Steneteg P , Walder R
Published: June 2023

We study with a 3D particle-in-cell simulation discontinuities between an electron–positron pair plasma and magnetized electrons and protons. A pair plasma is injected at one simulation boundary with a speed 0.6c along its normal. It expands into an electron-proton plasma and a magnetic field that points orthogonally to the injection direction. Diamagnetic currents expel the magnetic field from within the pair plasma and pile it up in front of it. It pushes electrons, which induces an electric field pulse ahead of the magnetic one. This initial electromagnetic pulse (EMP) confines the pair plasma magnetically and accelerates protons electrically. The fast flow of the injected pair plasma across the protons behind the initial EMP triggers the filamentation instability. Some electrons and positrons cross the injection boundary and build up a second EMP. Electron-cyclotron drift instabilities perturb the plasma ahead of both EMPs seeding a Rayleigh–Taylor (RT)-type instability. Despite equally strong perturbations ahead of both EMPs, the second EMP is much more stable than the initial one. We attribute the rapid collapse of the initial EMP to the filamentation instability, which perturbed the plasma behind it. The RT-type instability transforms the planar EMPs into transition layers, in which magnetic flux ropes and electrostatic forces due to uneven numbers of electrons and positrons slow down and compress the pair plasma and accelerate protons. In our simulation, the expansion speed of the pair cloud decreased by about an order of magnitude and its density increased by the same factor. Its small thickness implies that it is capable of separating a relativistic pair outflow from an electron-proton plasma, which is essential for collimating relativistic jets of pair plasma in collisionless astrophysical plasma.
Analysis of chaotic structures, bifurcation and soliton solutions to fractional Boussinesq model
Authors: Ali Asghar , Ahmad Jamshad , Javed Sara , Rehman Shafqat-Ur-
Published: June 2023

In this work, we used the space-time fractional coupled Boussinesq (STFCB) model that is essential tools in the study of quantum optics, steady physics, the variational string’s acoustic waves, ion vibrational frequencies, hydro-magnetic waves in cold plasma and many other fields. In order to put such new precise solutions of the aforementioned model, the modified Sardar-sub equation (MSSE) technique has been suggested with inside the sense of conformable derivative and the fractional order partial differential equation that is capable of changing into an ordinary differential equation by using the travelling wave transform. The scoring of solitons and other solutions demonstrates the MSSE technique compatibility for different constant values, which are shown in 3-D, 2-D and contour plots. Additionally, we discussed the examined model chaotic and dynamical tendencies. The theory of plane dynamical system is used to examine the chaotic patterns of the systems. The investigations are novel and unexamined. They can be utilized to explain the physical phenomena which have been simulated to provide details on the brief dynamical characteristics. According to numerical simulations modifying the parameters of frequencies and amplitudes has an impact on the system of dynamical properties. We indicated that the MSSE technique for creating precise solutions offers new and significant mathematical tools in applied mathematics.
Synthesis, structural, and microwave absorption properties of hematite (α-Fe2O3) and maghemite (γ-Fe2O3)
Authors: Husain H , Nurhayati N , Susanto A , Sujiono E H , Taryana Y , Krisdayanti K
Published: June 2023

This work demonstrated the synthesis, structural, and microwave absorption properties of hematite (α-Fe2O3) and maghemite (γ-Fe2O3) nanopowders. The desired samples are successfully synthesized from the natural ironstone of Indonesia by using the coprecipitation method. The variations of acidic environments during the synthesis process (i.e., pH 6 and 7) were done to obtain the maghemite and hematite phases. The combination of x-ray diffraction (XRD) and scanning electron microscopy (SEM) measurements was used to investigate the crystal and microstructure, respectively. Meanwhile, the vector network analyzer (VNA) was performed to examine the microwave absorption properties at x-band frequency. The structural measurements of the samples confirmed the formation of single-phase maghemite and hematite phases for precipitation pH 6 and 7, respectively, which showed the change in morphology after the precipitation process and sphere-like agglomerated particles of samples. The results Debye–Scherrer equation indicates that the crystal size of precipitated samples is on the order of nanometers. The microwave absorption characteristics through VNA measurements showed enhanced microwave absorption properties after the precipitation process; the RL
max of natural ironstone increased from −4.39 dB to −10,99 and −11,72 dB for S6 and S7 samples, respectively. Generally, the hematite and maghemite reveal the same pattern of absorption peaks. The RL
max of natural ironstone, S6, and S7 samples were observed at 10.52, 11.04, and 11,06 GHz, respectively. These results revealed that the variation of acidic environments during the synthesis process influenced the structure and microwave absorption.
A fluorescence-T1MR dual-mode analysis method for Fe3+detection in serum
Authors: Bai Wenfeng , Jin Li , Zeng Xiaodan , Liu Yaowei , Yu Shihua , Zhang Jianpo
Published: June 2023

Fe3+ is commonly found in living organisms and the surrounding environment, and an excessive amount of Fe3+ can cause significant harm to human health and the biological environment. Therefore, it is of great importance for human health to conduct a quantitative analysis of Fe3+. A dual-mode analytical method using MnO2/BSA/CdTe quantum dot complexes is developed for the detection of Fe3+ in solution. The variety of fluorescence intensity (F455 nm/F635 nm) of this system has an excellent linear relationship with the concentration of Fe3+ (0.7500–6.750 nmol·L−1) under the optimal conditions, and the lowest detection limit is 0.7004 nmol ·L−1. Meanwhile, the T1WI imaging performance of this system also shows a good linear relationship with concentraions of Fe3+ in a linear range of 0.7500–2.250 mmol·L−1, and the lowest detection limit of 0.2642 mmol·L−1. The quenching mechanism of this system is discussed, and results show that the interaction between Fe3+ and this system is a static quenching process. This fluorescence-T1MR dual-mode sensor is simple rapid, and easy operation, which could provide a new technology for detecting Fe3+ in solution.
Multisymplectic formalism for cubic horndeski theories
Authors: Doniz Mauricio , Gaset Jordi
Published: June 2023

We present the covariant multisymplectic formalism for the so-called cubic Horndeski theories and discuss the geometrical and physical interpretation of the constraints that arise in the unified Lagrangian-Hamiltonian approach. We analyse in more detail the covariant Hamiltonian formalism of these theories and we show that there are particular conditions that must be satisfied for the Poincaré-Cartan form of the Lagrangian to project onto J
1
π. From this result, we study when a formulation using only multimomenta is possible. We further discuss the implications of the general case, in which the projection onto J
1
π conditions are not met.
Manipulation of giant Kerr nonlinearity and Doppler broadening on graphene’s Landau level
Authors: Abbas Muqaddar , Badshah Fazal , Ali Hamad , Munir Akhtar , Ziauddin  , Zhang Pei
Published: June 2023

We propose monolayer graphene system and analyze the effects of giant Kerr nonlinearity and Doppler broadening. The focus is to construct and design experimentally viable model by which we can enhance the group index of the medium so that we have slow group velocity. For obtaining the desired goal, we consider Landau level of graphene monolayer placed perpendicular to magnetic field M Tokman et al (2013, Phys. Rev. lett.
110, 077404). Giant Kerr nonlinearity and Doppler broadening enhance the medium group index greatly, resulting in a slow group velocity that has uses in storage devices, optical buffering, quantum memory, and data processing. We also investigate the behavior exhibited by the weak probe’s transmission spectrum, which can change when the terahertz signal frequency is turned on and off. Advantages of under consideration model are its a 2D material whereas other materials are semiconductor or gaseous state. Also, Landau level of graphene has domains tuneable in tera hertz and infra-red region while we cannot tune the semiconductor and atomic media once the transition is chosen. Therefore, the proposed magnetized graphene system offers a tremendous opportunity for incorporating quantum interference into the development of optical solid-state devices.
Classification and quantification of entanglement through wedge product and geometry
Authors: Mahanti Soumik , Dutta Sagnik , Panigrahi Prasanta K
Published: June 2023

The wedge product of post-measurement vectors of a two-qubit state gives rise to a parallelogram, whose ‘area’ has been shown to be equivalent to the generalized I-concurrence measure of entanglement. In multi-qudit systems, the wedge product of post-measurement vectors naturally leads to a higher dimensional parallelepiped which yields a modified faithful entanglement measure. Our new measure fine grains the entanglement monotone, wherein different entangled classes manifest with different geometries. We present a complete analysis of the bipartite qutrit case considering all possible geometric structures where three entanglement classes of pure bipartite qutrit states can be identified with different geometries of post-measurement vectors: three planar vectors; three mutually orthogonal vectors; and three vectors that are neither planar and not all of them are mutually orthogonal. It is further demonstrated that the geometric condition of area and volume maximization naturally leads to the maximization of entanglement. The wedge product approach uncovers an inherent geometry of entanglement and is found to be very useful for the characterization and quantification of entanglement in higher dimensional systems.