Mirpur University of Science and Technology

The precise control of electromagnetic wave behavior is essential for the development of next-generation photonic and communication devices. Metamaterials enable advanced wave manipulation through their unique electromagnetic properties. Among their key building blocks, metallic nanowires have been designed to dilute plasma frequency, a concept validated at microwave frequencies. Existing nanowire models face limitations; the quasi-static voltage-current models apply only to dipole-dominant nanoparticles, while wave impedance methods require infinite series expansion. These constraints highlight the need for a computationally efficient and physically intuitive modeling approach. This work introduces a cylindrical wave impedance framework at optical frequencies, deriving impedance expressions that simplify the dominant-mode resonance analysis under TE polarization by mapping it to a linear circuit model. The dominant mode is validated through simulations and Mie theory comparisons, ensuring accuracy. The proposed compact and intuitive model enhances understanding of wave-nanowire interactions, aiding the design of plasmonic and metamaterial-based applications. It also opens new avenues for the analytical treatment of complex nanostructures in both research and practical device engineering.

Fabrication of CuO/ZnO nanocomposite (NC) via the green method is an easy and environmentally friendly process. In this research work, CuO/ZnO NC were fabricated using Jasminum mesyni (J. mesyni) leaf extract, which acted as a reducing and capping agent. The prepared NC was characterized by Ultraviolet–visible (UV–VIS) spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), Transmission electron microscopy (TEM), Scanning electron microscopy (SEM), and Energy dispersive X-ray (EDX). Morphological imaging of the synthesized nano-product through TEM revealed spherical to quasi-spherical particles. XRD established the crystallinity of the synthesized NC, having an average crystallite size of 16 nm. EDX spectrum indicated the existence of oxygen, copper, and zinc in the product. After characterization, the synthesized CuO/ZnO NC was tested for photocatalytic and antibacterial activity. The photocatalytic experiment showed the degradation of methylene blue (MB) in 40 min. The synthesized nano-product demonstrated good photocatalytic activity under sunlight irradiation. The bactericidal activity of CuO/ZnO was tested against three gram-positive (B. subtilis, S. aureus, and S. pyogenes) and three gram-negative (P. mirabillis, E. coli, and P. aurginosa) bacteria at various concentrations. IC50 values of the bactericidal activity of the prepared NC were also calculated for each pathogenic bacteria. The results of antibacterial activity revealed an increase in antibacterial activity with increasing concentration.

In this paper, the numerical analysis is performed on two-dimensional incompressible and natural convection flow of viscous nanofluid by considering the effects of heat generation and porous medium. For this purpose, is regarded as nanoparticles dispersed in some base fluids, including water, methanol, and engine oil. Essentially, the goal of this work is to examine the flow characteristics and thermal performance of three distinct nanofluids. The objective of this study is to measure the effects of thermophysical interactions, porous drag, and nanoparticle loading on heat transmission and irreversibility. Several assumptions are used to develop the flow model. With the appropriate transformation, the two-dimensional non-linear partial differential equations become non-linear ordinary differential equations. In MATLAB software, the Bvp4c technique is utilized to find the numerical outcomes of the flow model. The graphs are modelled by plotting several parameters against the velocity and temperature profiles. The impacts of skin friction and the Nusselt number are assessed for several involved parameters. To investigate the energy loss, the entropy generation model is also assumed. The velocity field marks the incrementing impact due to the thermal Grashof number. By producing the values of the porous media parameter, resulting in the velocity field of the nanofluid methanol + Ti6Al4v being very low. We noted that the methanol + Ti6Al4v has an extremely low velocity field when the porous medium parameter is big. When the curvature parameter is increased, the temperature field for engine oil rises swiftly in relation to the volume fraction and for water + Ti6Al4v nanofluid.

This paper investigates the widely used Zig-zag optical lattice prototype for cold bosonic atoms. This prototype generally represents nonlinear waves in plasma physics and fluid mechanics. To obtain soliton solutions, two different techniques are used, the Kumar-Malik method and the improved F-expansion approach. These solutions include periodic, kink, combo dark-bright, bright, and dark types of soliton solutions. The conducted soliton solutions show that the approach is capable of identifying a wide range of wave patterns in nonlinear partial differential equation (NLPDE) models and is also compatible, effective, and scientifically efficient. Using the Maple software, 3D, contour, density and 2D structures were created for various values of the relevant parameters in order to do numerical simulations of the outcomes. To the best of our knowledge, no previous study has explored this equation to such an extent. All the solutions obtained are verified using the Maple software application, ensuring their accuracy and correctness.

In this paper, we examine the flow of a convective Maxwell fluid through a channel with a sensor surface placed between two parallel plates, for applications in cooling electronic devices, microfluidics, environmental monitoring, and the oil and gas industries. The flow is squeezed from one side, and the channel surface is instrumented with a microcantilever sensor. The heat- and mass-transfer equations are formulated using the Cattaneo–Christov model, to incorporate heat absorption and a chemical reaction. Boundary-layer approximations are considered, and similarity transforms convert the partial differential equations into linear ordinary differential equations, which are solved numerically. The effects of various parameters on velocity, concentration, and temperature gradients are analyzed. Results show that the velocity of the Maxwell fluid decreases with higher thermal and solutal Grashof numbers and the Maxwell fluid parameter. The thermal-relaxation parameter and heat-absorption coefficient contribute to a reduced temperature distribution. The concentration decreases with variations in the solutal relaxation coefficient and reaction parameter. Physical quantities, such as skin friction, decline due to the Maxwell fluid parameter. A comparison with previously published results is also included.