Volume 78, Issue 12

The impact of dust streaming and polarization force on dust acoustic solitary waves (DASWs) is examined in a non-magnetized dusty plasma made up of negatively charged dust, superthermal ions, and Maxwellian electrons. In the linear limit, the dispersion relation is derived and numerically analyzed. In order to explore the characteristics of arbitrary amplitude DASWs, a Sagdeev potential technique is used. It is explored how the existence domain and characteristics of the DASWs are affected by the polarization force connected to the superthermality index of ions and dust streaming. The relevance of the present study to space dusty plasma, in particular to Saturn’s F-ring, is highlighted.

In this paper, the work is concerned with the study of moving boundary based on non-classical heat equation that includes a time dependent heat flux and convection. The latent heat is represented as a function of the moving interface. Mathematical model accounts for a control function varying with heat flux. We have obtained the explicit solution of the given mathematical model in the presence of convection and a control function. The Legendre wavelet Galerkin approach (LWGA) is used to solve the mathematical problem. In a particular case, our numerical results were compared with previous results and found to be in excellent agreement. Moreover, the current numerical technique is more efficient and accurate in comparison to the previous available method. An extensive analysis of the problem parameters is presented. It is found that the control function offers a significant contribution during the melting or freezing of a PCM. A greater value of the heat flux accelerates the rate of propagation of interface. Convection heat transfer increases the speed of the interface. Results obtained from the current study are expected to improve the fundamental understanding of heat transfer and aid in sublimation and desorption like physical phenomena.

We propose a Nambu Jona-Lasinio (NJL) effective model of relativistic superconductivity. In this framework, we discuss possible electromagnetic (EM) behaviors of (specifically) type-II superconductivity in line with the nonrelativistic Ginzburg–Landau (GL) theory. We comment on possible solitonic solutions of this model. Our investigation could be of relevance to describe type-II proton superconductivity in neutron-star crusts.

Momentum is characterized in terms of inertial mass for particles moving at less than the speed of light, but entirely in terms of their energy for those lacking inertia. Does this difference suggest a physically distinct origin of momentum in the two cases and, if so, what is actually being conserved in interactions involving both types of particle? In this paper, we consider a recently proposed gravitational origin for rest-mass energy to demonstrate that a single definition of momentum applies to all particles, massless or otherwise. When introduced into this description, inertial mass is merely a surrogate for the particle’s ‘free’ energy, but does not imply an origin of momentum different from that of particles without mass.

This study deals with the instability of shear waves, also known as Kelvin–Helmholtz instability, propagating with a complex frequency ” ω ” in magnetically quantized dense gyro-viscous plasmas. The instability arises from the transverse spatial shear of the streaming velocity, which evolves from the DC electric and magnetic fields. In dense plasmas, quantum effects contribute through magnetically quantized statistical Fermi pressure, tunnelling potential and exchange-correlation potential. The contribution of the shear profile, the drift velocity, the number density of medium species, the dc magnetic field and the propagation angle θ of the wavevector on the instability is pointed out analytically as well as graphically. By varying the angle, shear size and density of plasma particles, the growth rate is enhanced. It does not, however, change as the streaming speed increases. This work seeks applications to study the characteristics of complex media like astrophysical and semiconductor plasmas [R. P. Drake, “Hydrodynamic instabilities in astrophysics and in laboratory high-energy–density systems,” Plasma Phys. Control. Fusion , vol. 47, p. B419, 2005].

In quantum scattering theory, the time evolution of a physical system can be described as a series of unitary transformations. The operator of this transformation will be denoted S ̂ $\hat{\boldsymbol{S}}$ ; the corresponding matrix is the Ŝ -matrix (scattering matrix). This last object contains all the information on the broadcast process associated with the operator S ̂ $\hat{\boldsymbol{S}}$ The present work has two objectives: To develop the one-dimensional formalism of the scattering matrix of relativistic particles of spin-s ( s  = 0, 1/2) in the presence of a localized electromagnetic field on the one hand and on the other hand to analyze the solutions of the problem of scattering states of relativistic particles of spin-s in interaction with some localized scalar potentials via the S ̂ $\hat{S}$ -matrix formalism.

In this work, we report an effective approach based on an artificial intelligence technique to investigate the secondary ions mass spectroscopy (SIMS) profiles of boron, phosphorus and arsenic ions. Those dopant ions were implanted into n- and p-type (100) Silicon substrate using the ion implantation technique with energy of 100 and 180 keV. Annealing treatment was conducted at various temperatures ranging from 900 to 1030 °C for 30 min. The doping profile parameters such as the activation energy, diffusion coefficient, junction depth, implant dose, projected range and standard deviation were determined using particle swarm optimization (PSO) algorithm. The efficiency of this strategy was experimentally verified by the fitting between both real measured SIMS profile and predicted ones. In addition, a set of simulated doping profiles was generated for different annealing time to prove the ability of this approach to accurately estimate the above parameters even when changing the experimental conditions.

In this study, the transfer matrix method is used to analyze the optical properties of a layered structure, {Air(SrTiO 3 /BSCCO) 20 Substrate}, consisting of air, SrTiO 3 , BSCCO (bismuth strontium calcium copper oxide) bilayers, and a substrate. This paper aims to investigate the transmittance spectra of two proposed one-dimensional (1D) structures, including a conventional superconductor photonic crystal (PC) and a gyroidal superconductor PC at infrared (IR) wavelengths. A comprehensive analysis has been carried out to provide useful insights into the optical properties and the behavior of the proposed structure, highlighting the impact of many parameters, such as refractive index, filling fraction, and layer thickness. The numerical findings showed that the permittivity of the BSCCO superconductor of a gyroidal geometry takes a different response compared to the conventional one. Notably, the filling fraction and refractive index of the host material have a significant control on both real and imaginary parts of the gyroidal BSCCO permittivity through the considered wavelengths. Thus, the proposed design provides high transmittivity outside the obtained photonic band gap compared to the conventional one. We believe that the designed one-dimensional gyroidal BSCCO photonic crystals could act as an efficient reflector through near IR for optoelectronics and energy applications.

The work explores the heat transfer capabilities of semiconducting graphitic carbon nitride (g-C 3 N 4 ) nanofluids. Also, it presents a sustainable and eco-friendly method for synthesizing g-C 3 N 4 nanoparticles using commercially available rice flour as a natural carbon precursor through hydrothermal treatment. The synthesized sample subjected to various characterizations, including analysis of their structure, morphology, thermal properties, and optical properties. The optical bandgap (2.66 eV) is deduced through Tauc plot analysis and reveals the semiconducting nature of the sample. The formation of g-C 3 N 4 is confirmed by various spectroscopic techniques, including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR), and Raman spectroscopy. Thermogravimetric analysis (TGA) demonstrates the nanoparticles’ excellent thermal stability up to 550 °C, indicating potential applications in heat transfer fluids. The investigation of concentration-dependent thermal diffusivity variation using the sensitive mode mismatched dual beam thermal lens technique highlights the potential of g-C 3 N 4 semiconductor nanofluid as an organic and metal-free additive in industry-demanding coolant applications.

This work reports the sol–gel synthesis of zirconia (ZrO 2 ) nanoparticles (NPs) in which the effect of varying molarities of zirconium oxychloride salt (such as 0.025 M, 0.050 M, 0.075 M, 0.100 M, and 0.125 M) has been investigated on the structural, mechanical, and optical characteristics by maintaining a basic pH at 9. All experimental conditions were conducted using basic media, with XRD, SEM, hardness, and optical analysis performed. Structural analysis, which was performed by using an X-ray diffractometer, reveals the formation of mixed phase zirconia (tetragonal and monoclinic) under as-synthesized conditions. Optical analysis shows that transmission increases as the molarity grows. The refractive index and extinction coefficient conform to the normal dispersion behavior, while the refractive index is observed to increase as the molarity becomes large. A high value of the refractive index of about 1.65 and lowest value of band gap 3.96 eV have been observed at a molarity of 0.075 M in the UV region. The hardness is observed to be continuously increased as the molarity grows, wherein the maximum hardness of 1167 HV is observed at a molarity of 0.075 M within the considered molarities (0.025 M, 0.050 M, 0.075 M, 0.100 M, and 0.125 M).