Journal of Theoretical and Applied Physics
Journal of Theoretical and Applied Physics is an international peer-reviewed, open-access and free-of charge bimonthly scientific journal. The JTAP covers all fundamental and applied experimental and theoretical physics research. Journal DOI: 10.57647/jtap Journal Abbreviation: J Theor Appl Phys Journal Title Acronym: JTAP Journal Owner: Islamic Azad University Publisher: Islamic Azad University, Co-publishing, OICC Press, UK Keywords: Atomic and molecular physics, Solid state physics, Quantum physics, Nanophysics, Nuclear physics, Computational physics Editor-in-Chief: Seyedeh Mehri Hamidi, PhD 0000-0002-5298-2224 Associate Editors: Laya Dejam, PhD 0000-0003-3925-1838 Latest News: We only accept DOC or DOCX files for submission. We would like to inform all authors and contributors that, effective 1st November 2025, an Article Processing Charge (APC) will apply to all new submissions, manuscripts submitted on or after this date that are accepted for publication in the Journal of Theoretical and Applied Physics (JTAP).
Quantum Information and Elementary Particles
Motivated by string theory and standard model physics, we discuss the possibility of other particles-based quantum information. A special attention is put on the consideration of the graviton in light of the gravitational wave detection. This may offer a new take in approaching quantum information using messenger particles. The construction is readily extended to higher dimensional qubits where we speculate on possible connections with open and closed string sectors in terms of quiver and graph theories, respectively. In particular, we reveal that the vectorial qubits could be associated with skeleton diagrams considered as extended quivers.
Copyright (c) 2026 Adil Belhaj, Salah Eddine Ennadifi (Author) https://creativecommons.org/licenses/by/4.0
Analysis of Human Fingernails for Disease Diagnostics by Laser-Induced Breakdown Spectroscopy: An Advance Review
This systematic review highlights the role of nail analysis as a biomarker for the metabolic, diagnostic, and management of chronic diseases such as diabetes mellitus (DM), thyroid disorders, osteoporosis, and environmental exposure to heavy metals. It combines multi-method insights and a range of techniques, such as X-ray fluorescence (XRF) spectroscopy, inductively coupled plasma mass spectrometry (ICP-MS), atomic absorption spectrometry (AAS), and their comparison with Laser-Induced Breakdown Spectroscopy (LIBS). LIBS provides rapid, multi-element analysis with little or no sample preparation. This study is very beneficial because it provides a quick, simple, and affordable method of monitoring for diseases over time. LIBS is used as a strong analysis ability with nails as a permanent bio record and in early customized health checks because it works in both science and healthcare. The main challenges hindering the clinical transfer of LIBS are discussed, including matrix effects, spectral interferences, environmental interferences, and clinical validation through large-scale experiments and large sample numbers. Finally, the details are discussed for future prospects, focusing on the development of portable LIBS systems for point-of-care testing (POCT), the integration of AI-based diagnostic platforms, and the creation of global spectral databases for precision medicine.
Copyright (c) 2026 Sura Allawi Obaid, Muayyed Jabar Zoory, Haidar J. Mohamad (Author) https://creativecommons.org/licenses/by/4.0
The Quantized Dimensional Ledger for Metrology: Dimensional Closure, QMU Ledgers, and the Ontology of Physical Constants
This work introduces the Quantized Dimensional Ledger (QDL), a unified dimensional framework based on a 3L + 2F basis of length-like and frequency-like primitives. The QDL constructs a closed algebra of physical dimensions in which mass, time, and all derived quantities emerge from combinations of five operational axes: three geometric scales (L1, L2, L3) and two frequency scales (F1, F2). Within this basis, the Quantum Measurement Unit (QMU) is defined as a standardized ledger cell for energy, momentum, and action, enabling a structured representation of physical constants and observables. The framework yields a 20-entry dimensional ledger (Appendix B) spanning mechanics, electromagnetism, gravitation, thermodynamics, and quantum observables. This ledger provides a consistent classification system that clarifies which constants are dimensionless invariants and which are dimensional couplings whose exponents are fixed by the 3L + 2F structure. A key feature of QDL is dimensional closure, ensuring that the Einstein–Hilbert action, Maxwell action, and classical mechanical quantities share a common underlying exponent structure. This enables a unified interpretation of constants such as c, ℎ, G, and the fine-structure constant α as ledger invariants or as ratios of ledger entries. A quantitative demonstration is included, showing how ledger ratios reconstruct the structural dependence of Planck’s constant, the Rydberg constant, and vacuum impedance, with comparison to CODATA values. The purpose of this work is conceptual and metrological rather than dynamical: QDL does not propose new field equations, but offers an internally consistent dimensional ontology supporting the interpretation, classification, and potential reduction of physical constants.
Copyright (c) 2026 James D. Bourassa (Author) https://creativecommons.org/licenses/by/4.0
Investigation of Photon Interaction Parameters of Perovskite Ceramics Materials using Phy-X/PSD And NGCal Software
This study aims to evaluate the radiation shielding performance of selected metal oxide–based and oxide double perovskite ceramic materials using various photon attenuation parameters. The photon attenuation parameters were calculated and analyzed using Phy-X/PSD and NGCal software over the range of 0.015–15 MeV. The results, based on the total interaction cross-section of photon–matter interactions, show that all investigated samples exhibit higher attenuation efficiency in the low-energy region due to the dominance of the photoelectric effect, followed by a gradual reduction in shielding performance in the intermediate and high-energy regions, where Compton scattering and pair production prevail. Materials with higher atomic number (Z) and greater density demonstrate superior shielding performance, as reflected by higher MAC and LAC values and lower HVL, TVL, and MFP values. The radiation shielding parameters obtained from the two software tools were in good agreement, with differences within 0.1%. Overall, both perovskite families display promising radiation shielding capabilities, with oxide double perovskite samples showing enhanced attenuation efficiency compared to metal oxide–based perovskite composites, highlighting their greater potential for effective photon radiation shielding applications.
Copyright (c) 2026 Muhammed Abdurraheem, Wasiu Yahya, Sunday Ajani, Godwin Egbeyale (Author) https://creativecommons.org/licenses/by/4.0
Effects of Direct and Indirect Cold Plasma Treatments on Barley (Hordeum vulgare L.) Seed Germination and Seedling Growth
This study presents a comparative evaluation of direct and indirect cold plasma treatments on seed germination and seedling growth of barley (Hordeum vulgare L. cv. Sahra). Direct treatments was performed using low-pressure nitrogen glow discharge under ion-dominant (P1) and electron-dominant (P2) conditions, while indirect treatments employed plasma-activated water (PAW) generated via atmospheric-pressure dielectric barrier discharge (DBD) in deionized (PAW1) and tap water (PAW2). Germination rate, seedling vigor index, and early growth parameters were assessed under controlled conditions. The ion-dominant plasma treatment (P1) showed the highest germination rate (93.3%) and seedling vigor index (7082.0), outperforming PAW1 (79.7%), PAW2 (73.3%), and control (72.0%). In contrast, electron-dominant treatment (P2) reduced germination (60.3%), demonstrating the crucial role of plasma species composition in biological responses. The enhanced efficacy of PAW was associated with its physicochemical properties, particularly a reduced pH (3.42) and increased conductivity (174 µS/cm for PAW1, 1281 µS/cm for PAW2), which may facilitate the stabilization of reactive nitrogen species and improve seed coat permeability. Optical emission spectroscopy and water contact angle measurements supported plasma-induced surface hydrophilization and the presence of excited nitrogen species under ion-dominant conditions. These findings establish ion-dominant nitrogen cold plasma as an effective, chemical-free seed priming strategy and emphasize the importance of plasma regime control in optimizing sustainable agricultural applications.
Copyright (c) 2026 Samira Tajiknezhad, Ameneh Kargarian (Author) https://creativecommons.org/licenses/by/4.0
Real-time polarization tuning in Mach-Zehnder interferometer using electro-optically modulated twist angles of nematic liquid crystal
We propose a theoretical framework to dynamically control the degree of polarization of light by using the superposition of incoherent orthogonally polarized beams in a Mach-Zehnder interferometer incorporating a twisted nematic liquid crystal cell in one of its arms. The liquid crystal acts as an elecro-optically controlled polarization rotator, where the applied electric field changes the twist of molecules inside the nematic liquid crystal, thereby altering the plane of polarization. This controllable voltage dependent polarization rotation causes manipulation of the output degree of polarization. The resulting system allows real-time, tunable control over the degree of polarization, offering advantages over traditional static or reflection-based approaches, which often suffer from intensity losses or manual errors. We also observe that in the interference of fully coherent orthogonally polarized beams through a similar configuration, the degree of polarization is always equal to 1, whereas the orientation of linear state of polarization is changed with voltage.
Copyright (c) 2026 Rajneesh Joshi, Gyaprasad Gyaprasad (Author) https://creativecommons.org/licenses/by/4.0
First-Principles Investigation of the Structural, Electronic, and Optical Properties of Tl1-xBxN Alloys in the Zinc-Blende Phase
In this work, a comprehensive first-principles investigation of the structural, electronic, and optical properties of Tl₁₋ₓBₓN (x = 0.25, 0.50, and 0.75) alloys crystallizing in the zinc-blende phase is presented. To the best of our knowledge, a systematic theoretical study of these ternary alloys combining structural optimization, electronic structure analysis, and optical response including spin–orbit coupling effects has not been reported previously. The calculations were performed within density functional theory using the generalized gradient approximation. The optimized lattice parameters were obtained from total energy–volume calculations and exhibit a composition-dependent trend consistent with Vegard’s law, confirming the structural stability of the considered alloys. The electronic band structures reveal a pronounced dependence of the band gap on boron concentration, demonstrating the possibility of band gap engineering through composition tuning. The inclusion of spin–orbit coupling leads to a noticeable modification of the electronic structure and a reduction in the band gap, reflecting the significant relativistic effects associated with thallium atoms. The optical properties were analyzed in the photon energy range of 0 - 14 eV. The calculated dielectric function, absorption coefficient, refractive index, and reflectivity show strong sensitivity to boron content, indicating tunable optical behavior. Overall, the results highlight the potential of Tl₁₋ₓBₓN alloys for advanced optoelectronic and photonic applications, particularly in tunable semiconductor and ultraviolet device technologies.
Copyright (c) 2025 Abed Zoulikha, Abdelali Laid, Lachabi Abdelhadi, Abid Hamza (Author) https://creativecommons.org/licenses/by/4.0
Effect of Electrode Surface Roughness on Copper Oxide Nanoparticle Synthesis via Atmospheric-Pressure Plasma in Liquid
Atmospheric-pressure plasma–liquid interactions provide a non-equilibrium environment for surface modification and nanostructure formation under ambient conditions. In this work, the effect of copper surface roughness on copper oxide nanostructure formation is investigated using an atmospheric-pressure plasma-in-liquid configuration in a strongly alkaline electrolyte (3 M NaOH). Copper electrodes with three controlled roughness levels were exposed to stable argon microplasma under identical operating conditions. X- ray diffraction indicates the formation of crystalline copper oxide on the copper surface without the use of metal salt precursors. UV–Vis spectroscopy reveals optical features characteristic of copper oxide nanostructures. Electron microscopy shows a clear roughness-dependent morphological evolution, where coarse surfaces promote localized growth and agglomeration, while smoother surfaces lead to higher nucleation density and finer, more uniform nanostructures. Elemental analysis indicates copper and oxygen as the dominant constituents of the formed layers. The results demonstrate that surface roughness governs local electric field distribution and microdischarge interaction at the plasma–liquid interface, thereby controlling the balance between nucleation and growth. These findings highlight surface roughness as an effective parameter for tuning plasma–liquid-driven oxidation processes and contribute to a deeper understanding of plasma–liquid interaction mechanisms.
Copyright (c) 2025 Zohreh Dehghani (Author) https://creativecommons.org/licenses/by/4.0
Effects of q-Deformation on the Thermal Deconfinement Phase Transition in High-Energy Physics
The influence of the q-deformation parameter on the thermal deconfinement phase transition (DPT) from a hadronic gas phase to a Quark-Gluon Plasma (QGP) phase is investigated in this paper using analytical derivations and numerical simulations within the phase coexistence model. By studying key thermodynamic parameters such as specific heat, entropy, energy density, and the order parameter, we demonstrate how the phase transition dynamics are modified by the deformation parameter q. Our results indicate that increasing q lowers the critical transition temperature TC(q) while enhancing thermodynamic quantities like entropy and energy densities. Furthermore, the phase transition exhibits first-order characteristics, as evidenced by latent heat and discontinuities in thermodynamic functions near the critical point. Additionally, we study finite-size effects, which result in smoothed transitions in smaller system volumes. These findings underscore the relevance of q-deformation in high-energy physics, particularly in understanding the thermodynamics of QCD phase transitions and non-extensive statistical contributions.
Copyright (c) 2025 Lebba Ghenam, Karima Bouakaz (Author) https://creativecommons.org/licenses/by/4.0
Detailed Analysis of the Electronic and Structural Properties of the New Compound Tl₁₋ₓBx P, Taking into Account the Spin–Orbit Effect Using MBJ-GGA
We report an ab initio study of ternary Tl₁₋ₓBₓP alloys (x = 0.25, 0.5) in the zinc-blende structure using DFT with GGA and mBJ-GGA, including spin–orbit coupling (SOC). A 2×2×2 supercell based on TlN was used, where boron atoms were substituted by thallium. Our results show that while BP is an indirect semiconductor and TlN is metallic, Tl₁₋ₓBₓP alloys exhibit a semi-metallic character, bridging wide-gap borides and narrow-gap thallium compounds. Increasing boron content reduces the lattice constants and modifies the total energy, enabling precise tuning of electronic properties. This work highlights the stabilizing role of thallium in forming new alloy phases and provides a novel route for band-gap engineering in III–V semiconductors, considering SOC effects. These findings offer guidance for the design of future optoelectronic and electronic devices.
Copyright (c) 2026 Abdelali Laid, Abed Zoulikha, Lachabi Abdelhadi, Abid Hamza (Author) https://creativecommons.org/licenses/by/4.0
Generation of Surface Waves in a Magnetized Warm Plasma
This paper investigates the linear generation of surface waves in both cold and warm non-magnetized and magnetized plasma. Using a fluid-plasma model with Maxwell’s equations in the presence of an external magnetic field ( <!-- [if gte mso 9]><xml> <o:OLEObject Type="Embed" ProgID="Equation.3" ShapeID="_x0000_i1025" DrawAspect="Content" ObjectID="_1834411629"> </o:OLEObject> </xml><![endif]-->), we derive governing equations for wave generation via linear interactions between incident waves of identical polarization. Analytical solutions reveal that both S- and P-polarized incident waves generate P-polarized surface waves, demonstrating polarization selectivity induced by magnetic anisotropy. The results provide insight into wave mechanisms at plasma boundaries and suggest potential applications in plasma-based wave control and frequency conversion. These findings provide new insight into the mechanisms governing surface wave behavior in magnetized warm plasmas and extend earlier studies limited to unmagnetized or cold plasma models.
Copyright (c) 2025 Kh. H. El-Shorbagy, Hania Mahassen, W. H. Amein, Y. A. Sayed, E. S. Al-Zahrani (Author) https://creativecommons.org/licenses/by/4.0
Differential Cross-Section Analysis Using Thermal Volkov Wave Functions and Gaussian-Screened Potentials in Laser-Assisted Scattering
The aim of this work is to study the scattering behavior of electrons in a Gaussian-screened potential under polarized laser fields (linear, circular, and elliptical) within thermal and nonthermal environments. For this purpose, we developed a theoretical model using the thermal Volkov wave function to describe electron dynamics in the Gaussian-screened potential. Using the thermal Volkov wave function, we derived the scattering and transition matrices via the Kroll-Watson approximation. From the transition matrix, the differential cross-section was obtained, which directly characterizes the scattering behavior of electrons in the Gaussian-screened potential. The developed differential cross-section model was computed to analyze electron behavior under thermal and nonthermal conditions. Observations indicate that the differential cross-section is highest for elliptical polarization, followed by circular and linear polarizations. Additionally, the differential cross-section is greater in thermal environments compared to nonthermal ones. Also, the screening parameters significantly affect resonance positions and differential cross section magnitudes, shifting peaks toward smaller angles and increasing cross-section values at higher screening. Distance separation studies reveal contrasting trends between thermal and non-thermal regimes, and photon energy variations highlight polarization reversals at higher energies. The study demonstrates that differential cross section can be effectively manipulated by tuning polarization, screening, temperature, and scattering angle. This study shows that electron scattering with Gaussian-screened potentials can be controlled by tuning polarization, screening, temperature, and scattering angle, which has practical applications in plasma physics, fusion energy, and semiconductor technology. The findings also provide insights for advanced material processing, space plasma modeling, and the development of laser-based diagnostic tools.
Copyright (c) 2026 Dol Raj Paudel, Bibek Pandey, Madhurendra Lal Das, Hemant Bahadur Deuba, Kishori Yadav, Suresh Prasad Gupta, Saddam Husain Dhobi (Author) https://creativecommons.org/licenses/by/4.0
Creation of Avalanche Chain Reactions in p11B Fuel Using Magneto-Inertial Fusion
A proton beam is produced at a velocity of the order of <!-- [if gte msEquation 12]><m:oMath><m:sSup><m:sSupPr><m:ctrlPr></m:ctrlPr></m:sSupPr><m:e><m:r>10</m:r></m:e><m:sup><m:r>9</m:r></m:sup></m:sSup><m:r> </m:r><m:r>cm</m:r><m:r>/</m:r><m:r>s</m:r></m:oMath><![endif]--> to interact with an uncharged hydrogen-boron medium such as <!-- [if gte msEquation 12]><m:oMath><m:sSub><m:sSubPr><m:ctrlPr></m:ctrlPr></m:sSubPr><m:e><m:r>H</m:r></m:e><m:sub><m:r>3</m:r></m:sub></m:sSub><m:r>B</m:r></m:oMath><![endif]-->. The generated charged particles are confined by electromagnetic fields. This is the basic concept of the new non-thermal fusion reactor. An external electric field is applied to prevent the energy loss of the proton particles by friction, due to their interaction with the electrons of the medium, to keep the proton-boron fusion at a maximum cross-section. Alphas produced by <!-- [if gte msEquation 12]><m:oMath><m:r>p</m:r><m:sSup><m:sSupPr><m:ctrlPr></m:ctrlPr></m:sSupPr><m:e><m:r>B</m:r></m:e><m:sup><m:r>11</m:r></m:sup></m:sSup></m:oMath><![endif]--> fusion undergo nuclear elastic collisions with surrounding protons, triggering a <!-- [if gte msEquation 12]><m:oMath><m:r>p</m:r><m:sSup><m:sSupPr><m:ctrlPr></m:ctrlPr></m:sSupPr><m:e><m:r>B</m:r></m:e><m:sup><m:r>11</m:r></m:sup></m:sSup></m:oMath><![endif]--> CR. The aim of this paper is to estimate the key parameters related to the performance of a new fusion reactor with neutron-free fusion fuel <!-- [if gte msEquation 12]><m:oMath><m:r>p</m:r><m:sSup><m:sSupPr><m:ctrlPr></m:ctrlPr></m:sSupPr><m:e><m:r>B</m:r></m:e><m:sup><m:r>11</m:r></m:sup></m:sSup></m:oMath><![endif]-->considering the production of alpha particle avalanches by presenting only the main physical processes and not a complete engineering design. To achieve this goal, a conceptual fusion reactor is proposed in this work using laser-plasma interactions and magnetic confinement configurations. The final result of our work considering this new reactor shows that it is possible to achieve fusion energy gain about 115, which is much higher than other cases examined.
Copyright (c) 2025 Fatemeh Namdari, Seyede Nasrin Hosseinimotlagh (Author) https://creativecommons.org/licenses/by/4.0
Generalized Functional Analysis Approach for Bound State Solutions with Solvable and Quasi-Solvable Potentials
In this paper, a generalized functional analysis approach has been used to obtain the bound state solutions of the Schrödinger equation with solvable and quasi-solvable potentials. We extended the Nikiforov-Uvarov functional analysis method which has been limited to obtaining bound states solutions of exponential-type potentials. Here, we have generalized the approach to obtain the approximate and exact energy spectra and the corresponding wave functions of the Schrödinger equation under the Coulomb, Pseudo harmonic, hyperbolic, q-deformed hyperbolic and perturbed Coulomb potentials in closed forms. These potential functions with the Schrödinger equation were transformed into standard second-order linear differential equations such as the Whittaker, associated Laguerre, Gauss hypergeometric and the confluent Heun differential equations. The parameters of the wave functions and energy quantization conditions were derived from a direct comparison with the quantized systems of differential equations. Our results are in excellent agreement with the earlier works in which different approaches were utilized. Also, the quasi-exact energies for fixed potential parameters were found to be in good agreement with energy eigenvalues obtained via the matrix Numerov method.
Copyright (c) 2025 Ekwevugbe Omugbe, T.V. Targema, E.S. Eyube, C.A. Onate, S.O. Ogundeji, U.E. Vincent (Author) https://creativecommons.org/licenses/by/4.0
Propagation Characteristics of Higher-Order Hollow Sinh-Gaussian Laser Beams in Collisionless Plasma
Hollow sinh-Gaussian (HshG) beams are the appropriate analogue to describe optical beams with null central intensity. In the present work, the modified paraxial approach is adopted to study the propagation characteristics of higher-order HshG beams in plasma. The nonlinearity in the dielectric constant of plasma considered herein is of the ponderomotive type. A nonlinear differential equation is obtained for the beam-width parameter and then solved numerically to investigate the self-focusing/defocusing characteristics of HshG beams in plasma. The dependence of the beam-width parameter of HshG beams on the dimensionless distance of propagation through plasma has been specifically carried out. Results show that the self-focusing ability of the aforesaid beams weakens with an increase in the order of HshG beams. The effect of the initial intensity parameter and the normalized plasma frequency for higher-order HshG beams has also been examined.
Copyright (c) 2026 Prajakta P. Patil, Mansing V. Takale, Sandip D. Patil (Author) https://creativecommons.org/licenses/by/4.0
Fabrication of Different Photoluminescence Nanostructures of Cadmium Sulfide to Quickly Identify Heavy and Carcinogenic Metals Cadmium and Lead
In this study, the fabrication of photoluminescent cadmium sulfide nanostructures with various dimensions was explored to achieve rapid detection of the heavy and carcinogenic metals cadmium and lead. These metals have become increasingly significant in scientific research—particularly in environmental and health sciences—due to the serious hazards they pose to both human health and the environment. The focus of this work was to develop a fast and sensitive method for identifying these hazardous metals using nanostructured materials. To accomplish this, zero-dimensional, one-dimensional, and two-dimensional cadmium sulfide nanostructures were synthesized, and their photoluminescence characteristics were subsequently examined. Photoluminescence, the emission of light from a material upon optical or electrical excitation, is a key property that can be employed for the detection and identification of specific substances. The ability of these nanostructures to rapidly detect the carcinogenic heavy metals cadmium and lead was assessed and compared. Photoluminescence spectroscopic analysis—through evaluation of the intensity and wavelength of the emitted light—demonstrated that these nanostructures are capable of distinguishing between heavy metals and carcinogenic agents. The results indicate that producing photoluminescent cadmium sulfide nanostructures with different dimensionalities offers an effective approach for the quick and sensitive identification of cadmium and lead. This method provides greater speed and accuracy than conventional detection techniques and holds potential for use in laboratory, industrial, and medical applications.
Copyright (c) 2025 Mohammed Kareem Hanoon, Zhaleh Ebrahiminejad, Maryam Ali Asaad Al-Lami, Amir hoshang Ramezani, S. Asgary (Author) https://creativecommons.org/licenses/by/4.0
Disentangling Thermal and Degeneracy Pressure in Quantum-Confined Fermi Gases
A theoretical framework is developed to decompose the total pressure of a quantum-confined Fermi gas into degeneracy pressure, arising from Fermi–Dirac statistics, and thermal pressure, associated with finite-temperature excitations. Using Weyl’s conjecture for the confined density of states, geometric confinement effects are incorporated through surface- and edge-to-volume parameters (<!-- [if gte msEquation 12]><m:oMath><m:r>α</m:r></m:oMath><![endif]--> and <!-- [if gte msEquation 12]><m:oMath><m:r>β</m:r></m:oMath><![endif]--> ). Exact analytical expressions for both components are derived using polylogarithmic functions, and asymptotic forms are obtained for the strongly degenerate (<!-- [if gte msEquation 12]><m:oMath><m:r>T</m:r><m:r>≪</m:r><m:sSub><m:sSubPr><m:ctrlPr></m:ctrlPr></m:sSubPr><m:e><m:r>T</m:r></m:e><m:sub><m:r>F</m:r></m:sub></m:sSub></m:oMath><![endif]--> ) and weakly degenerate (<!-- [if gte msEquation 12]><m:oMath><m:r>T</m:r><m:r>≫</m:r><m:sSub><m:sSubPr><m:ctrlPr></m:ctrlPr></m:sSubPr><m:e><m:r>T</m:r></m:e><m:sub><m:r>F</m:r></m:sub></m:sSub></m:oMath><![endif]--> ) regimes. The analysis shows that quantum confinement enhances degeneracy pressure by a factor of (<!-- [if gte msEquation 12]><m:oMath><m:r>1+</m:r><m:f><m:fPr><m:type m:val="lin"/><m:ctrlPr></m:ctrlPr></m:fPr><m:num><m:r>5</m:r><m:sSup><m:sSupPr><m:ctrlPr></m:ctrlPr></m:sSupPr><m:e><m:r>α</m:r></m:e><m:sup><m:r>F</m:r></m:sup></m:sSup></m:num><m:den><m:r>16</m:r></m:den></m:f></m:oMath><![endif]--> )​,​ while suppressing thermal pressure, with the contrast most significant under strong degeneracy. The maximum relative error in the total pressure, occurring at the crossover temperature <!-- [if gte msEquation 12]><m:oMath><m:sSup><m:sSupPr><m:ctrlPr></m:ctrlPr></m:sSupPr><m:e><m:acc><m:accPr><m:chr m:val="̃"/><m:ctrlPr></m:ctrlPr></m:accPr><m:e><m:r>T</m:r></m:e></m:acc></m:e><m:sup><m:r>*</m:r></m:sup></m:sSup><m:r>~0.604282</m:r></m:oMath><![endif]--> , is about 22%, while that for thermal pressure reaches 52%. The asymptotic expressions remain valid across <!-- [if gte msEquation 12]><m:oMath><m:sSup><m:sSupPr><m:ctrlPr></m:ctrlPr></m:sSupPr><m:e><m:r>α</m:r></m:e><m:sup><m:r>F</m:r></m:sup></m:sSup><m:r>∈</m:r><m:d><m:dPr><m:begChr m:val="["/><m:endChr m:val="]"/><m:ctrlPr></m:ctrlPr></m:dPr><m:e><m:r>0.1, 0.5</m:r></m:e></m:d></m:oMath><![endif]--> and <!-- [if gte msEquation 12]><m:oMath><m:sSup><m:sSupPr><m:ctrlPr></m:ctrlPr></m:sSupPr><m:e><m:r>β</m:r></m:e><m:sup><m:r>F</m:r></m:sup></m:sSup><m:r>∈</m:r><m:d><m:dPr><m:begChr m:val="["/><m:endChr m:val="]"/><m:ctrlPr></m:ctrlPr></m:dPr><m:e><m:r>0.01, 0.2</m:r></m:e></m:d></m:oMath><![endif]--> . Separating thermal and degeneracy contributions enables improved interpretation of thermodynamic measurements in confined quantum systems where only total pressure is accessible. The framework is relevant for nanoelectronic devices, ultracold atomic gases, and quantum dots, offering insight into how spatial confinement differentially shapes thermal and quantum contributions to observable thermodynamic behavior.
Copyright (c) 2025 Coskun Firat (Author) https://creativecommons.org/licenses/by/4.0
Pressure-Volume Response in Nanomaterials: Contrasting Graphenic ‎Sheets, Oxide Ceramics, and Transition Metal Architectures
This investigation presents a comprehensive theoretical examination of pressure-induced volumetric compression characteristics in five structurally diverse nanomaterials: graphite, aluminium oxide (Al2O3), single-walled carbon nanotubes (SWCNTs), nano-epsilon-phase iron (nano-ε-Fe), and nano-nickel (nano-Ni), representing carbon allotropes, ceramic oxides, and transition metal systems. Four established equations of state (Tait, Murnaghan, Kholiya and Chandra, and Shanker) were employed using experimentally derived bulk modulus values and their pressure derivatives from literature to model relative volumetric changes under applied pressure up to 16 GPa. The analysis reveals material-specific compressibility behaviours dictated by bonding characteristics, atomic configuration, and dimensionality. Al2O3 demonstrates the highest incompressibility among studied materials due to its strong ionic-covalent bonding, while SWCNTs exhibit pronounced nonlinear compression attributed to structural instabilities under confinement. Nano-Ni and nano-ε-Fe show intermediate compressibility with enhanced sensitivity due to nanoscale effects including surface energy influences and modified coordination environments. The study validates the applicability of classical equations of state for predicting nanoscale mechanical responses and provides critical insights for material selection in nanodevice design for biomedical, energy, and high-pressure applications.
Copyright (c) 2026 Tajamul Islam, A.K Srivastava, Mudasir Mir, Santosh Chackrabarti, R.A. Zargar (Author) https://creativecommons.org/licenses/by/4.0
Ultra-Compact and Highly Sensitive Pressure Sensor Based on a 2D Photonic Crystal Square-Ring Resonator for High-Pressure Range (0 to 10 GPa)
This study presents an optical platform for pressure sensing based on a square-ring resonator. Numerical simulations reveal a shift in the resonant frequency towards lower frequencies, concomitantly with a shift in the resonant wavelength towards higher wavelengths, in response to an increase in applied pressure. Two simulation methodologies, the plane wave expansion (PWE) method and the finite-difference time-domain (FDTD) method, were employed to extract the guided mode and analyze the functional characteristics of the proposed sensor under varying pressure constraints. The envisioned structure is distinguished by a high-quality factor, a sensitivity of approximately 4.39 nm/GPa over a dynamic range from 0 to 10 GPa, and an ultra-compact footprint of 274 μm². These properties render this structure particularly suitable for integration into microscale photonic integrated circuits.
Copyright (c) 2026 Elhachemi Kouddad, Hassan Dahbi, Sououdi Boumediene Chabani, Islam Hassani, Nourddine Kaddouri (Author) https://creativecommons.org/licenses/by/4.0
Optimization of ‎Copper Ion ‎Concentration into ‎the Lattice of ‎Barium Sulphide ‎Nanoparticles ‎Synthesized via a ‎Chemical ‎Approach
Copper barium sulphide (<!-- [if gte msEquation 12]><m:oMath><m:sSub><m:sSubPr><m:ctrlPr></m:ctrlPr></m:sSubPr><m:e><m:r><m:rPr><m:scr m:val="roman"/><m:sty m:val="p"/></m:rPr>Cu</m:r></m:e><m:sub><m:r><m:rPr><m:scr m:val="roman"/><m:sty m:val="p"/></m:rPr>x</m:r></m:sub></m:sSub><m:sSub><m:sSubPr><m:ctrlPr></m:ctrlPr></m:sSubPr><m:e><m:r><m:rPr><m:scr m:val="roman"/><m:sty m:val="p"/></m:rPr>Ba</m:r></m:e><m:sub><m:r><m:rPr><m:scr m:val="roman"/><m:sty m:val="p"/></m:rPr>1-x</m:r></m:sub></m:sSub><m:r><m:rPr><m:scr m:val="roman"/><m:sty m:val="p"/></m:rPr>S</m:r></m:oMath><![endif]--> <span style="font-size: 11.0pt; line-height: 107%; font-family: 'Calibri',sans-serif; mso-ascii-theme-font: minor-latin; mso-fareast-font-family: Calibri; mso-fareast-theme-font: minor-latin; mso-hansi-theme-font: minor-latin; mso-bidi-font-family: Arial; mso-bidi-theme-font: minor-bidi; position: relative; top: 4.0pt; mso-text-raise: -4.0pt; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;"> ) thin films (TFs) were fabricated via the chemical bath deposition (CBD) approach on glass substrates. The study used solutions of copper (II) sulphate, barium chloride dihydrate, and thiourea as the sources of the elements (copper, barium, and Sulphur). The thin films were characterized using the x-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) and ultraviolet-visible spectroscopy. XRD examination of the films revealed that they were polycrystalline and increased with doping concentrations. However, increasing copper incorporation led to an increase in the average crystallite sizes from 18.80 to 21.96 nm, accompanied by a decrease in dislocation density (δ) (<!-- [if gte msEquation 12]><m:oMath><m:r><m:rPr><m:scr m:val="roman"/><m:sty m:val="p"/></m:rPr>2.83 x </m:r><m:sSup><m:sSupPr><m:ctrlPr></m:ctrlPr></m:sSupPr><m:e><m:r><m:rPr><m:scr m:val="roman"/><m:sty m:val="p"/></m:rPr>10</m:r></m:e><m:sup><m:r><m:rPr><m:scr m:val="roman"/><m:sty m:val="p"/></m:rPr>-</m:r><m:r><m:rPr><m:scr m:val="roman"/><m:sty m:val="p"/></m:rPr>3</m:r></m:sup></m:sSup><m:r><m:rPr><m:scr m:val="roman"/><m:sty m:val="p"/></m:rPr> to 2.08 x </m:r><m:sSup><m:sSupPr><m:ctrlPr></m:ctrlPr></m:sSupPr><m:e><m:r><m:rPr><m:scr m:val="roman"/><m:sty m:val="p"/></m:rPr>10</m:r></m:e><m:sup><m:r><m:rPr><m:scr m:val="roman"/><m:sty m:val="p"/></m:rPr>-</m:r><m:r><m:rPr><m:scr m:val="roman"/><m:sty m:val="p"/></m:rPr>3</m:r></m:sup></m:sSup><m:sSup><m:sSupPr><m:ctrlPr></m:ctrlPr></m:sSupPr><m:e><m:r><m:rPr><m:scr m:val="roman"/><m:sty m:val="p"/></m:rPr>nm</m:r></m:e><m:sup><m:r><m:rPr><m:scr m:val="roman"/><m:sty m:val="p"/></m:rPr>-</m:r><m:r><m:rPr><m:scr m:val="roman"/><m:sty m:val="p"/></m:rPr>3</m:r></m:sup></m:sSup><m:r>)</m:r></m:oMath><![endif]--> <span style="font-size: 11.0pt; line-height: 107%; font-family: 'Calibri',sans-serif; mso-ascii-theme-font: minor-latin; mso-fareast-font-family: Calibri; mso-fareast-theme-font: minor-latin; mso-hansi-theme-font: minor-latin; mso-bidi-font-family: Arial; mso-bidi-theme-font: minor-bidi; position: relative; top: 4.0pt; mso-text-raise: -4.0pt; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;"> , and strain (ε) (<!-- [if gte msEquation 12]><m:oMath><m:r><m:rPr><m:scr m:val="roman"/><m:sty m:val="p"/></m:rPr>1.84 x </m:r><m:sSup><m:sSupPr><m:ctrlPr></m:ctrlPr></m:sSupPr><m:e><m:r><m:rPr><m:scr m:val="roman"/><m:sty m:val="p"/></m:rPr>10</m:r></m:e><m:sup><m:r><m:rPr><m:scr m:val="roman"/><m:sty m:val="p"/></m:rPr>-</m:r><m:r><m:rPr><m:scr m:val="roman"/><m:sty m:val="p"/></m:rPr>3</m:r></m:sup></m:sSup><m:r><m:rPr><m:scr m:val="roman"/><m:sty m:val="p"/></m:rPr> to 1.58x </m:r><m:sSup><m:sSupPr><m:ctrlPr></m:ctrlPr></m:sSupPr><m:e><m:r><m:rPr><m:scr m:val="roman"/><m:sty m:val="p"/></m:rPr>10</m:r></m:e><m:sup><m:r><m:rPr><m:scr m:val="roman"/><m:sty m:val="p"/></m:rPr>-</m:r><m:r><m:rPr><m:scr m:val="roman"/><m:sty m:val="p"/></m:rPr>3</m:r></m:sup></m:sSup><m:r><m:rPr><m:scr m:val="roman"/><m:sty m:val="p"/></m:rPr>)</m:r></m:oMath><![endif]--> <span style="font-size: 11.0pt; line-height: 107%; font-family: 'Calibri',sans-serif; mso-ascii-theme-font: minor-latin; mso-fareast-font-family: Calibri; mso-fareast-theme-font: minor-latin; mso-hansi-theme-font: minor-latin; mso-bidi-font-family: Arial; mso-bidi-theme-font: minor-bidi; position: relative; top: 4.0pt; mso-text-raise: -4.0pt; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;"> respectively. Energy-dispersive X-ray analysis reveals good agreement between detected and selected element ratios with different stoichiometry. Optical examination indicated that <!-- [if gte msEquation 12]><m:oMath><m:sSub><m:sSubPr><m:ctrlPr></m:ctrlPr></m:sSubPr><m:e><m:r><m:rPr><m:scr m:val="roman"/><m:sty m:val="p"/></m:rPr>Cu</m:r></m:e><m:sub><m:r><m:rPr><m:scr m:val="roman"/><m:sty m:val="p"/></m:rPr>x</m:r></m:sub></m:sSub><m:sSub><m:sSubPr><m:ctrlPr></m:ctrlPr></m:sSubPr><m:e><m:r><m:rPr><m:scr m:val="roman"/><m:sty m:val="p"/></m:rPr>Ba</m:r></m:e><m:sub><m:r><m:rPr><m:scr m:val="roman"/><m:sty m:val="p"/></m:rPr>1-x</m:r></m:sub></m:sSub><m:r><m:rPr><m:scr m:val="roman"/><m:sty m:val="p"/></m:rPr>S</m:r></m:oMath><![endif]--> <span style="font-size: 11.0pt; line-height: 107%; font-family: 'Calibri',sans-serif; mso-ascii-theme-font: minor-latin; mso-fareast-font-family: Calibri; mso-fareast-theme-font: minor-latin; mso-hansi-theme-font: minor-latin; mso-bidi-font-family: Arial; mso-bidi-theme-font: minor-bidi; position: relative; top: 4.0pt; mso-text-raise: -4.0pt; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;"> TFs have a transmittance that increased from 20% to 50% with an increase in copper concentrations, while the optical band gap varied from 1.65 to 3.12 eV. These results indicate that the synthesized <!-- [if gte msEquation 12]><m:oMath><m:sSub><m:sSubPr><m:ctrlPr></m:ctrlPr></m:sSubPr><m:e><m:r><m:rPr><m:scr m:val="roman"/><m:sty m:val="p"/></m:rPr>Cu</m:r></m:e><m:sub><m:r><m:rPr><m:scr m:val="roman"/><m:sty m:val="p"/></m:rPr>x</m:r></m:sub></m:sSub><m:sSub><m:sSubPr><m:ctrlPr></m:ctrlPr></m:sSubPr><m:e><m:r><m:rPr><m:scr m:val="roman"/><m:sty m:val="p"/></m:rPr>Ba</m:r></m:e><m:sub><m:r><m:rPr><m:scr m:val="roman"/><m:sty m:val="p"/></m:rPr>1-x</m:r></m:sub></m:sSub><m:r><m:rPr><m:scr m:val="roman"/><m:sty m:val="p"/></m:rPr>S</m:r></m:oMath><![endif]--> <span style="font-size: 11.0pt; line-height: 107%; font-family: 'Calibri',sans-serif; mso-ascii-theme-font: minor-latin; mso-fareast-font-family: Calibri; mso-fareast-theme-font: minor-latin; mso-hansi-theme-font: minor-latin; mso-bidi-font-family: Arial; mso-bidi-theme-font: minor-bidi; position: relative; top: 4.0pt; mso-text-raise: -4.0pt; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;"> TFs hold significant potential for applications in solar energy and optoelectronics.
Copyright (c) 2026 McDonald Chukwudi OKAFOR, Lawrence Ese ESIEKPE, Vivian Anulichukwu ATTOH, Nwando Blessing OKEKE, Azuka Bright OKWUELUM, Joseph Onyeka EMEGHA‎ (Author) https://creativecommons.org/licenses/by/4.0
Study of Intra-Molecular C−H‧‧‧O Bonded Chair Conformer of (R)−(−)−Menthyl Acetate using Combined Spectroscopic and Computational Methods
The intra-molecular C−H‧‧‧O bond has been studied in (R)−(−)−Menthyl Acetate employing both DFT and QT-AIM methods. The B3LYP/6−311+G(d,p) level has predicted a stable chair conformation in agreement with measured IR and Raman modes. This C−H‧‧‧O bonded chair conformer is also supported by a downfield shift at δ 4.68 ppm (computed δ 4.78 ppm) in the measured 1H NMR spectrum and positive values of electron density and its Laplacian obtained from QT−AIM. The computed H···O distance (2.351 Å) in C–H···O bond is shorter than the sum of van der Waals radii of H and O atoms, 2.720 Å. A strong positive Cotton effect at 232 nm in the ECD spectrum corresponds to the medium UV band at 241 nm (other bands: 219 and 276 nm) and is assigned to the n→π* transition. It is argued that the good agreement between computed CD band at 214 nm and its corresponding experimental band at 232 nm support proposed intra−molecular C−H‧‧‧O bonded chair conformer for (R)−(−)−Menthyl Acetate. The charge delocalization in C−H‧‧‧O bond is characterized by overlapping n(2)O→π*(C=O) natural bond orbitals with ~47 kcal/mol stabilization energy. The C−H‧‧‧O bonding and its neighbor atoms are shown in terms of electron localization function and localized orbital locator as electron density distributions and their spatial locations in the interaction.
Copyright (c) 2026 Kiran Gadivaddar, J. Tonannavar, Jayashree Tonannavar (Author) https://creativecommons.org/licenses/by/4.0
Rashba Coupling Assisted Negative Differential Conductance in Graphene Based Quantum Antidot Nano-Ribbon
Characteristic quantum transport features of a graphene-based quantum antidot structure which has been considered between two semi-infinite zig-zag graphene leads is investigated theoretically. The RPA-Keldysh method has been employed to capture Colomb interaction between the carriers in the presence of the Rashba interaction. It has been realized that the Colomb interaction results in negative differential conductance (NDC) which significantly depends on the strength of the Rashba coupling.
Copyright (c) 2026 Kobra Hasanirokh, Neda Shahabi, Arash Phirouznia (Author) https://creativecommons.org/licenses/by/4.0
Exploring ‎propagation ‎regimes of ‎amplitude-‎modulated dark ‎and antidark ‎Gaussian laser ‎beams in plasma
In this work, we analyzed three distinct propagation regimes of amplitude-modulated dark and antidark Gaussian (DADG) laser beams in plasma by considering ponderomotive nonlinearity. Based on Wentzel-Krammers-Brillouin (WKB) and paraxial approximations, the nonlinear differential equation for the beam-width parameter of DADG beams is derived. The behaviour of DADG beams propagation is elucidated through the analysis of critical and divider curves. The dependence of the beam-width parameter on propagation distance is illustrated for different values of the modulation parameter of DADG beams. The relevance of axial intensity and dielectric function with the dependence of the beam-width parameter of DADG beams on the distance of propagation has been illustrated. Further, the effect of plasma temperature and inhomogeneity on the self-focusing of DADG beams in plasma has been explored. The fundamental Gaussian beam is obtained as a particular case of the present study. Our results show that the self-focusing of antidark (dark) Gaussian beams is more (less) pronounced as compared with fundamental Gaussian beam.
Copyright (c) 2026 Manisha B. Mane, Prajakta P. Patil, Mansing V. Takale, Sandip D. Patil (Author) https://creativecommons.org/licenses/by/4.0
Laser Induced Fluorescence Enhancement by MgF2 Metasurface
We have experimentally examined the effect of all dielectric metasurface onto the laser induced fluorescence in flexible polydimethylsiloxane based structure. The host medium of the Rh6G dye achieved by spin coating over the two dimensional all dielectric MgF2 structure. The spectral fluorescence response of the multilayer sample in four different incidence energies indicate that the field enhancement due to Electric and magnetic dipoles resonance can boost laser induced fluorescence. Adjusting the wavelength due to different unit cell size and also incidence laser power, can open new insights in developing low cost and ohmic loss less devices.
Copyright (c) 2026 Noor Abdulameer, nizar Shnan, Lazem Aboud (Author) https://creativecommons.org/licenses/by/4.0
Physical Properties of Common Two-Temperature ‎Fusion Plasmas
Here, we investigate thermal relaxation dynamics in dense, non-isothermal plasmas using a binary plasma framework combined with the effective interaction potential method, which is crucial for understanding thermonuclear burn processes. The analysis covers primary fusion fuels, including DT (neutron-yielding) and aneutronic fuels such as D³He and p¹¹B. Electron and ion temperatures (Tₑ and Tᵢ) are considered independently, since intra-species equilibration occurs significantly faster than inter-species energy exchange due to the substantial mass difference. Addressing the computational challenges associated with simulating confined fusion plasmas—arising from multiple coupled physical phenomena—we introduce, for the first time, the effective interaction potential approach as a computationally efficient and accurate method for dense plasma systems. These potentials account for both (i) long-range charge overlap effects and (ii) short-range quantum interactions. Within this framework, we evaluate critical plasma properties, including stopping power, deceleration time, energy transfer coefficients, absorbed energy, and temperature relaxation rates for p¹¹B, D³He, and DT fuels, providing valuable insights into the optimal conditions for thermonuclear performance.
Copyright (c) 2025 Mehdi Kavehnia, Hossein Sadeghi, Seyede Nasrin Hosseinimotlagh (Author) https://creativecommons.org/licenses/by/4.0
Analytical and symmetry approaches to the Gardner-Kawahara equation: solitary wave solutions and conservation laws
In this paper, we investigate invariant solutions of the Gardner–Kawahara (GK) equation, an extended form of the Korteweg–de Vries (KdV) equation that models solitary wave propagation in plasmas, shallow water with surface tension, and magneto acoustic media using the Lie symmetry method. The study is divided into two main parts. In the first, we systematically derive infinitesimal generators and perform symmetry reductions to obtain nonlinear ordinary differential equations (ODEs), which are solved using the tanh and power series methods. Exact traveling wave solutions are constructed and illustrated graphically to reveal the influence of key parameters on wave dynamics. Conservation laws are also derived using the multiplier homotopy method. In the second part, we examine the modulational instability (MI) of uniform wave trains through linear stability analysis. The instability condition highlights the contrasting effects of nonlinearity and higher-order dispersion. Numerical simulations demonstrate unstable modulation bands. The present work illuminates wave breaking, energy localization, and pattern formation in nonlinear dispersive media. The results enhance our knowledge of intricate wave dynamics governed by the GK equation, and can be used in various domains such as fluid dynamics, plasma physics, and nonlinear optics.
Copyright (c) 2025 SWAIN SRADHARAM (Author) https://creativecommons.org/licenses/by/4.0
Safety Assay of Marketed Paracetamol Tablet by ‎Using Raman Spectroscopy Technique
Controlling and identifying the degraded products and impurities in the drug materials are the key issues in assuring the stability and quality of drugs throughout their shelf life, from both pharmaceutical and toxicological perspectives. Although, the drugs are packaged in a controlled environment at room temperature (25°C; 60% Relative Humidity (RH)), they may be exposed to elevated temperature and humidity during use, especially in regions with diverse climatic conditions. This study investigates the degradation of the Active Pharmaceutical Ingredient (API) of paracetamol tablet due to storage in inappropriate environmental conditions. The empirical method relies on the investigation of the respective Raman spectra of two groups of tablets; bare and packaged tablets. First, the accuracy of the analytical method used is evaluated, showing acceptable precision and accuracy within the range of the pharmacopeia guidelines with the Relative Standard Deviation (RSD)of less than ±5%. The tablet packaging effectively prevents moisture absorption; however, the API degradation process due to increased temperature is inevitable, and noticeable degradation in both tablet groups takes place after 30 minutes. The resulting data is validated using paracetamol tablets produced by different companies. Exposure to elevated temperatures leads to a noticeable degradation of paracetamol across different brands, all following similar trends. Also, the inappropriate environmental conditions result in the formation of the toxic compound P-aminophenol within the tablet. As the API degradation progresses, the corresponding characteristic Raman peak of P-aminophenol becomes more pronounced. Therefore, Raman spectroscopy technique can be operationalized as a standard method for online controlling of drug quality in both production lines and in the market.
Copyright (c) 2025 Mohadeseh Keshavarz Mohammadian, Somayeh. Karimi, Seyed. Hassan. Tavassoli (Author) https://creativecommons.org/licenses/by/4.0
Ion-Acoustic Wave Structures in a Collisionless ‎Magnetised Plasma Considering (r, q)-‎Distributed Electrons and k-Distributed ‎Positrons
This study addresses the properties of nonlinear ion-acoustic solitary waves (IASWs) within a magnetised plasma composed of ions, inertialess electrons, and positrons with a density gradient where electron and positron particles follow distinct non-Maxwellian energy distributions. To model this system, we derive a governing nonlinear evolution equation, known as the Zakharov-Kuznetsov (ZK) equation, using a standard reductive perturbation method (RPM). This equation is then analysed as a dynamical system to study the resulting solitary wave (SW) structures qualitatively. Through extensive numerical analysis, we investigate how physical parameters such as temperature and density ratios, the degree of non-thermality, the soliton velocity, the direction cosines, and the strength of the magnetic field affect the wave profile. A key finding is that, in contrast to the other non-thermal distributions, the amplitude of the solitary waves (SWs) is highest when the electron distribution approaches the standard Maxwellian case.
Copyright (c) 2025 Jintu Ozah, P.N. Deka (Author) https://creativecommons.org/licenses/by/4.0
Exploring Tl 1-xB x as: A New Addition to the Family of ‎Advanced Materials with Distinct Structural, Electronic ‎and optical Properties
In this study, we present a theoretical investigation of the structural, electronic, and optical properties of the ternary compound Tl₁₋ₓBₓAs (0 < x < 1) crystallizing in the zinc blende (ZB) structure, using density functional theory (DFT) within both the generalized gradient approximation (GGA) and the modified Becke–Johnson (mBJ-GGA) potential. The calculated results reveal that the crystal lattice maintains its structural stability across all studied boron concentrations. Within the GGA approach, the alloy exhibits a metallic nature with no distinct band gap between the valence and conduction bands. However, when the mBJ-GGA correction is applied a remarkable direct band gap emerges at the boron concentration of x = 0.75, highlighting its semiconducting behavior. From an optical point of view the imaginary part of the dielectric function indicates that the absorption edge starts from zero energy for low boron concentrations (x = 0.25 and 0.5) and extends up to around 8 eV while it shifts to approximately 10 eV for x = 0.75, indicating a wider absorption range. This broad optical response combined with structural stability and tunable electronic properties suggests that Tl₁₋ₓBₓAs alloys are promising materials for advanced technological applications particularly in optoelectronic and semiconductor–metal transition devices.
Copyright (c) 2025 Zoulikha Abed, Laid Abdelali, Abdelhadi Lachabi (Author) https://creativecommons.org/licenses/by/4.0
Self-Focusing of Gaussian Laser Beam in ‎Unmagnetized Plasma Described by Kappa ‎Distribution
Empirical kappa distributions have become increasingly widespread across space and plasma physics. In the present paper, logical straightforward extension of dielectric function of plasma described by Kappa parameter is employed to study the interaction of Gaussian laser beam with plasma. The nonlinear differential equation describing evolution of beam-width parameter is established by using parabolic wave equation approach under WKB and paraxial approximations. The effects of Kappa parameter and ratio of the thermal velocity of plasma electrons to the velocity of light on the propagation dynamics of Gaussian laser beam in non-Maxwellian plasma are specifically inspected. It is shown that the larger Kappa parameter and thermal velocity of electrons become more significant for stronger self-focusing of Gaussian beam in plasma. This enables the need of more exploration of physical mechanisms involved in the field of interaction of lasers with non-Maxwellian plasma.
Copyright (c) 2026 Prajakta P. Shinde, Prajakta P. Patil, Mansing V. Takale, Sandip D. Patil (Author) https://creativecommons.org/licenses/by/4.0