299 reads in the past 30 days
Investigation of viscous supersonic laminar flows around F-16 airfoil: experimental, numerical, and analytical approachesNovember 2023
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5,718 Reads
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2 Citations
Published by IOP Publishing
Online ISSN: 1402-4896
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Print ISSN: 0031-8949
Disciplines: Physics, Multidisciplinary
299 reads in the past 30 days
Investigation of viscous supersonic laminar flows around F-16 airfoil: experimental, numerical, and analytical approachesNovember 2023
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5,718 Reads
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2 Citations
168 reads in the past 30 days
Raman reference database for organic molecules by using a Coupled-Optical Fiber Raman SpectrographDecember 2023
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2,047 Reads
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4 Citations
156 reads in the past 30 days
Statistical inference and optimal plans for improved adaptive type-II progressive censored data following Kumaraswamy-G family of distributionsJanuary 2025
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159 Reads
155 reads in the past 30 days
System of fractal-fractional differential equations and Bernstein wavelets: a comprehensive study of environmental, epidemiological, and financial applicationsJanuary 2025
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161 Reads
106 reads in the past 30 days
Fabrication and acoustic absorption properties of electrospun polyacrylonitrile nanofiber membranesJanuary 2025
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170 Reads
Physica Scripta is an international journal dedicated to presenting novel and accessible research findings across the breadth of theoretical and experimental physics.
February 2025
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7 Reads
Color image encryption techniques have garnered significant attention due to their importance in safeguarding sensitive visual data. This paper introduces RESAKey GAN, a novel generative adversarial network that leverages the Residual Self-Attention mechanism to generate highly secure cryptographic keys for color image encryption. RESAKey GAN employs a redesigned architecture based on Wasserstein GAN with Gradient Penalty, addressing issues such as mode collapse and training instability. The network incorporates three novel loss functions tailored for image encryption tasks, enhancing key randomness, correlation, sensitivity, and visual appearance. Experiments conducted on the SIPI dataset demonstrate that RESAKey GAN generates private keys with excellent security, robust scrambling and diffusion performance, enabling effective encryption of diverse image scenarios using a simple XOR operation. Our approach mitigates concerns associated with traditional key generation algorithms and showcases the potential of deep learning in advancing color image encryption techniques.
February 2025
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7 Reads
The simultaneous ground-state cooling and the quantum synchronization of multiple mechanical oscillators are very important in the study of the quantum coherence of the optomechanical system with multiple mechanical modes. In this paper, we propose a scheme for investigating the simultaneous ground-state cooling and the quantum synchronization of two mechanical oscillators based on an optomechanical system via backward stimulated Brillouin scattering. A photon-phonon interaction via the backward stimulated Brillouin scattering process is introduced in this scheme, which is beneficial for cooling the optomechanical system. It is found that simultaneous ground-state cooling and quantum synchronization of two mechanical oscillators can be achieved when a suitable photon-phonon coupling via the backward stimulated Brillouin scattering process is chosen. Quantum synchronization is enhanced with the help of the photon-phonon coupling via the backward stimulated Brillouin scattering process. In addition, the relation between simultaneous ground-state cooling and quantum synchronization is discussed. It turns out that the appearance of simultaneous ground-state cooling is accompanied by quantum synchronization, but simultaneous ground-state cooling may not be realized when quantum synchronization is achieved. Our scheme paves a new way for the control of the quantum properties of the mechanical oscillators based on optomechanical system.
February 2025
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13 Reads
This study explores the effects of nonthermal nonextensive particles on the destabilization of Alfvén-cyclotron (AC) modes in collisionless anisotropic non-equilibrium magnetized plasmas. We employ the superextensive and subextensive anisotropic Cairns-Tsallis distribution functions (CTDF) through two distinct theoretical frameworks: model-I (M-I) and model-II (M-II). M-I delineates a temperature model that is invariant with respect to nonthermality and nonextensivity, whereas M-II incorporates a temperature that intrinsically depends on these parameters. Utilizing the linear plasma kinetic theory, we derive the dielectric response function and solve it numerically for AC modes in superextensive and subextensive Cairns-Tsallis distributed plasmas (CTDPs) for both models. Intriguingly, we observe a marked difference in the behavior of AC instability for the two models; M-II significantly augments instability growth in superextensive CTDP compared to M-I, while an opposite trend is manifested in the case of subextensive CTDP. Our investigation further elucidates the impact of pivotal parameters such as plasma beta (β∥) and ion temperature anisotropy (ηi) on real and imaginary frequencies of AC modes. This study also offers an in-depth comparative analysis of AC instability in anisotropic CTDP (encompassing both subextensive and superextensive cases), as well as in anisotropic Cairns, and bi-Maxwellian plasmas.
February 2025
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6 Reads
Ab initio calculations were performed to investigate the effects of strain on the structural, electronic, and vibrational properties of the Bi2Sr2CaCu2O8 (Bi-2212) compound. To accurately represent the Bi-2212 ground state, a modulation correction was applied, generating a distorted structure with lower symmetry that better represents the incommensurate superstructure observed in this compound. Phonon spectra and electronic properties were calculated under various levels of c-axis strain, ranging from −2.0% to +2.0%. For the electronic properties, minor changes were observed in the electronic density of states and band structure. However, trends could be identified by analyzing the fine features of the band structure through a tight-binding model. The most significant changes were observed in the vibrational properties, where different trends emerged for the various Raman-active modes. The changes observed in the vibrational and electronic properties can be explained by examining the distances and overlap populations of the relevant bonds, as well as the reduced mass of certain modes. This work can serve as an input for analyzing experimental measurements, helping to distinguish structural effects from others.
February 2025
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8 Reads
We develop a deterministic patch model for the transmission of Nipah virus in bat, pig, and human populations. The mathematical analysis of the model reveals that the disease-free equilibrium is globally asymptotically stable when the basic reproduction number R0 is less than 1, and unstable when R0>1 . In the case where R0>1 , there exists at least one positive equilibrium. Under the assumption of symmetric connectivity matrices, the basic reproduction number is increasing in terms of the dispersal rate of exposed humans, if the dispersal rates of symptomatic and asymptomatic humans are zero. On the other hand, if the direct transmission rates of symptomatic and asymptomatic infections are equal and the dispersal rates of exposed and symptomatic humans are zero, the basic reproduction number is increasing in terms of asymptomatic humans. For small dispersal rates, the endemic equilibrium approaches an endemic equilibrium with relatively lower endemic level.
February 2025
Pius Privatus
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Umananda Dev Goswami
This study aims to investigate whether the environment and the nuclear activity of a particular galaxy influence the ageing and quenching at the transition stage of the galaxy evolution using the volume-limited sample constructed from the twelve release of the Sloan Digital Sky Survey. To this end, the galaxies were classified into isolated and non-isolated environments and then each subsample was further classified according to their nuclear activity using the WHAN diagnostic diagram, and ageing diagram to obtain ageing and quenching galaxies. The ageing and quenching galaxies at the transition stage were selected for the rest of the analysis. Using the star formation rate and the u-r colour-stellar mass diagrams, the study revealed a significant change of 0.03 dex in slope and 0.30 dex in intercept for ageing galaxies and an insignificant change of 0.02 dex in slope and 0.12 dex in intercept of the star formation main sequence between isolated and non-isolated quenching galaxies. Further, a more significant change in the number of ageing galaxies above, within and below the main sequence and the green valley was observed. On the other hand, an insignificant change in the number of quenching galaxies above, within and below the main sequence and the green valley was observed. The study concludes that ageing depends on the environment and the dependence is influenced by the nuclear activity of a particular galaxy while quenching does not depend on the environment and this independence is not influenced by the nuclear activity.
February 2025
Wei Li
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Feng-ning Xue
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Peng-bo Zhao
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Yong Lu
The traditional three-phonon scattering approach cannot adequately reflect the anharmonic phonon properties of the ZrS 2 system due to its strong intrinsic anharmonicity. In this study, the vibrational properties and lattice thermal conductivity of both bulk and monolayer ZrS 2 were investigated using large-scale machine learning force field molecular dynamics simulations and the anharmonic phonon approach, where all orders of anharmonic interactions between phonons caused by temperature were considered. At finite temperatures, the predicted Raman-active in-plane E g mode of the bulk phase ZrS 2 decreases, while the inter-plane A 1g mode shifts to the blue, in agreement with experimental observations. Due to the competition between the chemical bond ionicity and phonon anharmonicity, the vibrational stiffness and frequency of the A 1g mode in monolayer ZrS 2 exhibit inverse temperature-dependent behavior compared to the bulk phase. Phonon linewidths and scattering rates increase significantly with temperature, indicating stronger anharmonic interactions in ZrS 2 . The lattice thermal conductivity of bulk ZrS 2 is significantly reduced when anharmonic phonon scattering beyond three-phonon processes is considered, with an average value of 1.91±0.08 Wm ⁻¹ K ⁻¹ at 300 K, which aligns with experimental results. Acoustic phonon modes dominate heat transport, with the lifetime of the TA mode being particularly temperature-sensitive. Monolayer ZrS 2 exhibits enhanced lattice thermal conductivity, more than twice that of the bulk, due to the reduced unit cell volume and increased phonon lifetimes.
February 2025
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1 Read
Panlong Li
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Dan Li
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Yuqian Zhou
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[...]
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Yuguang Yang
This paper introduces a novel alternated two-particle discrete-time quantum walk model on arbitrary graphs, overcoming the limitation that conventional shared coin schemes are confined to regular graphs. By employing a fixed-dimension coin operator and encoding the graph structural information into the shift operator, the new model becomes applicable to arbitrary graphs. Further, by adding interaction between the two particles, an extension is presented, which can enhance the model’s dynamic properties and facilitate more intricate quantum interference phenomena. Based on the new model, a kind of quantum graph isomorphism algorithm framework is proposed. It just need O(N0.5*∣E∣) steps of quantum walk and O(N²) dimensions of Hilbert space, which offers a significant reduction in complexity compared to other quantum walk based algorithms. The graph isomorphism testing is performed in the framework using non-interacting and interacting quantum walks respectively. Experimental results illustrate that the algorithm based on interacting particles achieves a 100% success rate in discriminating all test graphs. While the algorithm with non-interacting particles performs a 100% distinction success rate on general non-regular graphs, albeit being ineffective on strongly regular graphs. Due to the effectiveness of the algorithm on arbitrary graphs, the algorithm has broad application prospects in the identification and comparison of chemical molecular structures, the analysis of social networks and so on.
February 2025
Xing Heng
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Weiyi Wang
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Fan Wang
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[...]
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Kai Wei
The generation of multi-mode squeezing using four-wave mixing process has attracted considerable attention, offering significant potential for advancements in quantum communication, quantum key distribution, and quantum-enhanced sensing. In this paper, we propose a balanced regime within the dual-four-wave mixing (DFWM) process to theoretically generate quantum-enhanced multi-mode squeezed light. By operating at a plane-balanced regime, the relative intensity squeezing noise factor of the multi-mode beams can be made to approach zero theoretically, thus achieving perfect multi-mode squeezed states. Moreover, the generated beams at the plane-balanced regime exhibit quantum-enhanced entanglement superior to that of conventional four-wave mixing processes, offering significant implications for quantum information processing. The DFWM process can also be extended to multi-spatial-mode squeezing with a spatial-balanced regime, where the attainable squeezing degree is enhanced by a factor of GN, where N denotes mode numbers and G denotes the gain, facilitating simply experimental implementation within a single atomic system. The proposed method paves the way for practical applications in high-precision measurements, robust quantum communication networks, and advanced quantum information processing systems.
February 2025
ensuo Ma
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K. L. Zhang
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Z. Song
We study the topological bulk and edge correlations of condensed ground state in a p-wave Kitaev model on a square lattice. It is shown that the ground state of the system has the form of the condensate of the Bardeen-Cooper-Schrieffer pair, and the topological transition is associated with the nonanalytic behavior of the pairing order parameters. A real space correlation function is proposed to characterizing the topological phase of the many-body ground state. Numerical results demonstrate that this method works well in the presence of disordered perturbation, lattice defects, or irregular boundary conditions. In addition, the real space correlation function between two edges of the system is investigated, which directly reflects the existence of topological edge modes in the many-body ground state.
February 2025
Sakthikumaran Panneerselvam
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Salman Khan
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Anbarasu Manivannan
The threshold switching (TS) dynamics of Ovonic Threshold Switching (OTS) selector devices play a pivotal role in the programming speeds of Phase Change Random Access Memory (PCRAM) and Selector Only Memory (SOM). The TS phenomenon in amorphous selector devices rapidly reduces the initial high-resistance state to a low-resistance state within nanoseconds. In this work, we present a detailed experimental study of the time-resolved transient threshold switching characteristics of GeTe4 OTS devices, including measurements of delay time and holding voltage. The voltage-dependent delay time analysis reveals an exponential decrease in the delay time for the increase in the applied voltage above the threshold voltage. Moreover, the delay time rapidly decreased by an order for 10 % increase over the steady-state threshold voltage. Furthermore, the lowest delay time of approximately 300 picoseconds was observed for the input voltage of 1.8 V, i.e. 50 % higher than the steady state threshold voltage. These experimental findings on sub-nanosecond threshold switching dynamics in GeTe4 OTS devices pave the way for the development of high-speed PCRAM and SOM devices.
February 2025
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1 Read
Xulei Nan
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Lixia Li
Metastructures have shown good application prospects in wavefront manipulation. By studying the reconfigurable characteristics of metastructure, the great potential of metastructures in the multi-functional flexible control of flexural waves can be revealed.In this paper, a broadband flexible reconfigurable elastic solid-liquid-type metastructure is proposed. By filling cylindrical cavities with different volumes of liquid, the flexural wave band structure of the solid-liquid metastructure unit cell is regulated. Based on the functional relationship between the flexural wave frequency dispersion curve and the phase, the 0-2p accurate phase change of the flexural wave over a broadband range is realized. The design of subwavelength elastic metastructure based on the generalized Snell's law realizes the specified angular refraction of flexural waves over a wide range of frequencies without the need to remanufacture the metastructure. In addition, based on the bandgap properties of metamaterials, a metastructure for bidirectional selective transmission of flexural waves is designed. Finally, by changing the height of the liquid surface, the multiple functions of the solid-liquid reconfigurable metastructure in beam focusing and the phenomenon of generating non-diffracting Bessel beam are demonstrated. And when focusing the beam, we find a phenomenon, which uses a fixed phase profile to achieve flexural wave focusing at different frequencies. The reconfigurable solid-liquid type metastructure proposed in this paper provide a modulation for the active regulating of elastic flexural waves within a wide range of frequency, and provides a new idea for the development of reconfigurable elastic metastructure.
February 2025
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1 Read
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1 Citation
Fractal networks fluid flows have attracted significant research interest, yet most studies often assume a constant viscosity or power-law fluid flows. This research explores yield stress fluid flows in fractal tube networks, which are commonly found in engineered microfluidic devices and various industrial processes. We analyze optimal flow conditions and structures in tree-like branching networks using Herschel-Bulkley fluid model to understand yield stress materials. We focus on maximizing flow conductance under volume constraints, assuming steady, incompressible, fully developed laminar flow in circular tubes. We propose a conjecture that if the tube-wall stress, remains the same in the network for all branches, then an optimal solution exists and we derive the theoretical formulations for it. We find that the flow conductance is extremely sensitive to the geometry of the network. The effective conductance initially rises as the daughter-parent radius ratio increases, but eventually, it begins to decline. The peak conductance occurs at a specific radius ratio. We find that optimal network geometry depends on the number of branch splits N, and independent of the power-law index n and the yield stress τy. This optimal condition leads to an equal pressure drop as well as equal tube-volume across each branching generation level. Our results are validated with existing theory and extended to encompass shear-thinning and shear-thickening behaviors for any number of splits N with and without yield stress. Additionally, we derive relationships between geometrical and flow characteristics for parent and daughter tubes, including wall stresses, length ratios. These findings provide valuable design principles for efficient transport systems involving yield stress fluids.
February 2025
Qihao Wang
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Xiongwu Ju
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Can Yang
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[...]
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Jinyong Hu
Dielectric nanomaterials have attracted significant attention in the realm of micro- nano optics owing to the simultaneous low ohmic loss and distinctive electromagnetic resonance characteristic. However, achieving both ultra-narrow multi-band band and perfect absorption effects simultaneously has been challenging due to the weak magnetic response within traditional dielectric metamaterials. In this work, employing the finite-time domain differential method for simulation calculations, a multi-band perfect absorber consisting of titanium dioxide cylinder arrays is theoretically proposed. Benefiting from the concurrent presence of electromagnetic lattice resonance within the arrays of titanium dioxide cylinders, the as-proposed optical absorber demonstrates the simultaneous achievement of triple absorption bands, with extremely narrow spectral characteristics (minimum bandwidth approximately 0.8 nm) and near-perfect absorption rates (around 95.6%, 96.8%, and 95%) in 700-900 nm. Further near-field analysis unveils that surface lattice resonance arises from the synergistic interaction between the incident light and periodic structures, enhancing the coupling efficiency between the light and the surface plasmon, which can significantly amplify the electromagnetic field. By adjusting the lattice constant and geometric parameters, the physical mechanisms of the structure are further elucidated, and the optimal parameters of the absorber are ultimately determined. Moreover, due to its exceptional optical properties, the as-proposed multi-band absorber can be employed as a high-efficiency refractive index sensor with multi-frequency channel sensing. The corresponding sensitivity is calculated to be 356, 443.6 and 305.9 nm/RIU, with corresponding figure of merits of 482, 460.4 and 19.5 RIU-1, respectively. This research establishes a robust foundation for advancing multi-band perfect optical absorber, offering significant potential applications in multiple fields such as biochemical sensing, surface enhancement spectroscopy, and nonlinear nano-optics.
February 2025
This research presents a circuit-level hybrid CMOS memristor architecture for constructing Bidirectional Associative Memory (BAM). Initially, a synaptic circuit structure was built by employing a voltage threshold memristor in a crossbar architecture. This synaptic structure is adaptable and flexible for generating a wide range of synaptic weights. It is then deployed in the BAM network to perform an associative function. To aid in better name recall, this BAM network has been trained to associate Greek and mathematical symbols with their first letters in English, and vice versa. The designed circuit was validated using MATLAB and the EDA (Electronic Design Automation) Tool: Cadence Virtuoso. The addition of noise further evaluates the performance of the BAM network. When tested with noise levels of 10%, 20%, and 30%, the input patterns were retrieved at 100% in both directions. Furthermore, the proposed synaptic circuit is validated for variations in RON, ROFF and it’s performance is compared with other memristor models. It is also found that the average power consumption of the proposed synatic circuit is 1.22 mW. These results, which were experimentally confirmed, demonstrate the precision and noise isolation of the proposed BAM design. With appropriate tuning of memristor, the synaptic weights can be mapped easily with the memristor conductance value. This circuit can be effectively used in the field of image processing, neural network and neuromorphic computation which helps to associate and restore original or damaged binary images, showing strong robustness and accuracy.
February 2025
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7 Reads
Due to the large amount of information and intuitive characteristics, the image has become an important information carrier in our daily life, so its security has been an important direction in the field of information security. This paper mainly studies the problems of multiple images information hiding and visual security, and considers the advantages of block compressed sensing to design an image visual security encryption scheme. Firstly, we design a new chaotic map and block Arnold transform, combining with block compression sensing theory to scramble and encrypt the plain images after 2D Discrete Wavelet Transform (2D DWT), and obtain the secret images to be hidden. Finally, the secret images are embedded into the carrier image after the 2D Fast Fourier Transform (2D FFT) to hide, and the visually secure cipher image is obtained. Experiments demonstrate that the proposed scheme can effectively realize the information hiding and recovery of four images, while exhibiting strong robustness against noise interference and clipping attacks.
February 2025
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13 Reads
The article discusses the development of an infrared detector using a graphene lattice, focusing on how environmental temperature and external voltage affect its electrical conductivity. The study models environmental temperature as a phonon bath and uses random matrix theory and quantum chaos to analyze the impact of impurities and structural defects. Impurities and defects in the graphene lattice significantly impact both the multifractal dimension and conductivity. The applied external voltage increases the spread of the multifractal dimension, indicating a tendency toward localization at higher voltages. Additionally, the multifractal dimension narrows for the metal state and converges to a single point for localized states. The research highlights the importance of studying these factors to understand the conductivity phase and the ability to detect infrared photons. The findings suggest that changes in electrical current at specific bias voltages can be used to detect infrared photons, with a graphene lattice containing boron impurities operating effectively at room temperature.
February 2025
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16 Reads
This study investigates the influence of relativistic effects on some atomic properties of the halogen group and gold atoms, including their ions (±1). The analysis covers radii, orbital’s energy, first and second ionization energies, electron affinity, and polarizability. The study confirms that the p1/2 orbitals contract under relativistic effects, whereas for the p3/2 orbitals, the mass-velocity and spin–orbit effects do not appear to cancel each other out completely. This may indicate that the spin–orbit effect grows, when increasing the atomic number, slightly faster than the mass-velocity effect. In addition, expansion of the np3/2 orbitals may lead to dilation of the bond length in the related molecules. We found that the non-relativistic Hartree–Fock method gave, for atoms from fluorine to iodine, first ionization energy values with smaller deviations from their experimental ones than other methods involving relativistic and correlation effects. In particular, the method accurately, up to three significative digits, predicts the experimental value for chlorine, and thus can be adopted, discarding other sophisticated methods considering the huge computational effort required by them while not improving much on the agreement with experiment, when evaluating physical/chemical properties of large systems containing light halogen elements. It also predicts an electron affinity of 2.4 eV for the tennessine atom, where it shows also that the relativistic effects play a more important role than in gold atoms.
February 2025
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2 Reads
A compact quad-element multiple-input multiple-output (MIMO) antenna with self-isolation and pattern diversity features for 5G applications has designed in this article. In the proposed MIMO antenna design, drop-shaped slots have been cut from the ground plane to attain wide bandwidth of 1 GHz in the operating band 3.3–4.3 GHz of near radio (NR-77) band for 5G applications. Further, a criss-cross shaped isolator is formed after integrating four single wideband antenna elements with different orientations in the ground plane. This shape is responsible for high self-isolation of 25 dB in the desired band of 5G. Further, the 2D radiation pattern of the MIMO antenna has pattern diversity characteristics with a high peak gain of 6 dB in the working band, which validates the proposed work for the 5G MIMO application. The diversity performance of the proposed MIMO antenna has been validated with measured envelope correlation coefficient of 0.0002, diversity gain of 10 and channel capacity loss is below 0.5 bits s⁻¹ Hz⁻¹ across the entire frequency band. Furthermore, simulation studies have been demonstrated for different practical applications such as housing, automotive and on body for practical utility of proposed prototype.
February 2025
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24 Reads
In this work, we investigate the solitary wave solutions of two nonlinear evolution equations (NLEEs): the modified Camassa-Holm (MCH) equation and the Schrödinger-Hirota (SH) equation. Both are widely used, especially in fluid dynamics, nonlinear optics, and quantum mechanics. We analytically extract solitary wave solutions to the considered equations by applying the G′/G′+G+A -expansion method which enhances the understanding of wave dynamics in various fields of mathematical physics and engineering. The graphical representations of the obtained results of these two equations for certain values are shown in 3D, 2D, contour, and density plot diagrams, all of which are of the soliton types with one compacton, one anti-flat kink-shaped, one anti-bell-shaped, and one parabolic-shaped soliton. Moreover, we analyze the role of non-algebraic functions, specifically exponential and trigonometric functions, in characterizing the intricate waveforms and their stability properties. We systematically explore the applicability of the chosen expansion method, demonstrating its effectiveness in generating explicit solutions and examining the conditions under which these solitary wave phenomena arise. The novel findings contribute new analytical insights into these classical equations and pave the way for future research into the complex behaviors exhibited by nonlinear wave interactions.
February 2025
Dhyah Annur
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Syafian Falih Bilbusyra
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Lutviasari Nuraini
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[...]
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Yudi Nugraha Thaha
The growing demand for innovative metallic biomaterials for replacing and repairing dental tissue has increased due to the increasing number of people in the aging population and the expectation for an improved quality of life. In this study, a series of novel Ti-25Nb-xCu (25 and x = 3, 6, and 9, are in wt.%) alloys were fabricated by powder metallurgy processing in an argon atmosphere. The Nb content was fixed at 25 wt.%, while the Cu content was varied. The sintering temperature was 1300 °C, and the holding time was 4 hours. Physical characterization, microstructure, mechanical (hardness) properties, and corrosion behavior were observed. The microstructure of the Ti-25Nb-xCu alloys consists of α-Ti, β-Ti phases, and the precipitation of Ti 2 Cu. The lower content of Cu (Ti-25Nb-3Cu) would have a lamellar structure, while the higher content of Cu (Ti-25Nb-6Cu and Ti-25Nb-9Cu) would have a more equiaxed structure. The increasing percentage of Cu would increase the mechanical properties. As for the corrosion behavior, adding Cu did not significantly affect the corrosion resistance, but Ti-25Nb-6Cu was shown to have the highest corrosion resistance. Furthermore, Ti-25Nb-6Cu exhibited high antibacterial performance. Therefore, Ti-25Nb-6Cu was shown to be a promising material for dental implants.
February 2025
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18 Reads
We examine the influence of external circuit parameters on the breakdown of radio-frequency capacitively coupled plasma (RF-CCP) at pressures of 1 Torr and 10 Torr using a fluid-external circuit coupled model. At 1 Torr, best impedance matching delays the breakdown time, suggesting that non-best matching may expedite initiation. At 10 Torr, breakdown time decreases slightly under best matching, indicating minimal effect at higher pressures. Higher pressure divides the breakdown onset phase into two stages: an initial decrease in electron density with rising energy, followed by exponential density growth with oscillatory energy increases. Using best matching parameters enhances steady-state electron density and electron heating at both pressures. These findings highlight the significant role of external circuit parameters in the breakdown process and offer insights for optimizing plasma-enhanced chemical vapor deposition (PECVD) processes.
February 2025
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3 Reads
Aayushi Soni
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Ravibabu mulaveesala
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Satish Kumar Dubey
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Dalip Singh Mehta
Laser excitation of phosphorescent material (inorganic phosphor) to produce super-bright white light leads to thermal quenching. This article presents an innovative thermal heat reduction scheme that addresses the issue of phosphor heating. This study demonstrates a transparent conducting oxide film on a glass substrate under three conditions: low laser power with a heat sink, high laser power, and increased glass thickness. The characteristics of produced white light are examined in detail, and a thermal equivalent circuit is devised. Indium-tin oxide (ITO) film mitigates thermal and color instability issues, along with the flickering of a light source in transmission mode. Owing to the elevated conductivity of ITO film, it functions as a heat sink, absorbing thermal energy from the phosphor (luminescent material). It disperses to the underlying glass substrate via diffusion and into the ambient air more effectively than a conventional glass substrate. It is more economical than utilizing diamond, gold, or sapphire substrates. This work is expected to boost the applications of transmissive laser lighting. Experimental results of laser-based solid-state lighting (LBSSL) devices in transmission mode are presented utilizing indium-tin-oxide coated glass (ITOG). We observed substantial heat conduction through ITOG and reduced thermal quenching of the photoluminescent spectrum compared to standard glass.
February 2025
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2 Reads
Kiran Kumari
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Mayank Agarwal
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Hari Shankar Singh
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Rajesh Khanna
This paper presents the design and application of a planar H-plane horn antenna for agricultural purposes, specifically for the treatment of loamy wet soil using microwave radiation. The antenna is designed using Substrate Integrated Waveguide (SIW) technology resonated at 2.45 GHz, having a size of 1.37λ0× 1.04λ0× 0.012λ0. To achieve a unidirectional radiation pattern on an ultrathin substrate of 0.012λ0, two exponential slots are incorporated on the top and bottom of the substrate. The gain of the antenna is further enhanced using the interdigital capacitance concept. The proposed antenna is tested for its efficacy in soil disinfection by treating loamy wet soil contained in a pot with dimensions of 150 × 150 × 150 mm³. The applicator’s performance is analyzed by performing both steady state and transient analysis on both homogeneous and heterogeneous soil model. In homogeneous soil, 80°C is reached with 18 W (RMS) in 3384 seconds, while heterogeneous soil requires 24 W (RMS) and 4644 seconds. Experimentally, at a low input power of 28 watts (RMS), the maximum soil temperature achieved is 76.6°C, with the time taken to reach this temperature being 5400 seconds. The lowest temperature of 70°C is observed at a depth of 4.5 cm. This temperature range is effective for soil treatment, ensuring the eradication of soil-borne pathogens and pests. The findings demonstrate that the planar H-plane horn antenna is effective in uniformly distributing microwave radiation for soil treatment at lower power levels. This innovative approach offers a promising solution for sustainable soil management and enhanced agricultural productivity, highlighting the potential of advanced antenna designs in agricultural applications.
February 2025
Robin Saini
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Priyanka Wadhwa
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Karuna Jain
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[...]
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Manoj Kumar Singh
Metal Organic Frameworks (MOFs) and carbon derivatives based composites are an interesting class of materials having complementary properties, with the high surface area and tunable porosity of MOFs together with excellent electrical conductivity of carbon based materials. Here in, we report a facile one step solvothermal synthesis of composite made of MOF-5 and Eucalyptus bark derived rGO. MOF-5/rGO composite (MRG) has a high specific surface area (1150 m2 g-1). MRG was studied for electrochemical energy storage application using Cycle Voltammetry (CV), Galvanostatic Charge Discharge (GCD) and Electrochemical Impedance Spectroscopy (EIS). The MRG has high specific capacitance of 1366.6 F g-1 as calculated by GCD at 1 A g-1 current density, Energy density of 150.7 W h kg-1 and Power density of 450.3 W kg-1 at a current density of 1 A g-1 as calculated by GCD with 1M H2SO4 . The coulombic efficiency for the MRG composite was found to be 89.3% at higher current density. The cyclic stability data shown that composite material is retaining ~80.9% capacitance even after 10000 cycles. Moreover, symmetrical two electrode device of MRG shown a specific capacitance of 262.4 F g-1 at a current density of 1 A g-1, while the device retained 83.7% capacitance after 10000 charging discharging cycles. The energy density and power density of device were found to be 36.4 W h kg-1 and 498.6 W kg-1 at a current of 1 A g-1. The enhanced electrochemical performance of MRG is attributed to the synergistic effect between MOF-5 and rGO leading to the enhanced conductivity and provides larger surface area for charge storage.
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