Hasan Khaled Rouf

A comprehensive computational model was developed to simulate magnetic fluid hyperthermia (MFH), incorporating a realistic 3D human liver model with an irregular-shaped tumor. It provides an accurate and clinically relevant framework for effective treatment planning. The entire process of MFH, including nanofluid injection, diffusion, magnetic field generation, heat transfer, and subsequent tissue necrosis, is appropriately modeled and thoroughly analyzed. The generated magnetic field, produced by a system of 20 circular copper coils, achieved a maximum intensity of 2.57 kA m⁻¹ (34.60 Oe) and a maximum flux density of 3.46e-3 T within the tumor region. The temperature distribution within the tumor reached a peak of approximately 53.6 °C, resulting in significant tumor cell necrosis. The model accurately predicted the temporal and the spatial evolution of temperature, which was validated by comparing with the experimental measurements of hyperthermia in animal tumors. The nanoparticle diffusion profile was also validated against an analytical solution.

For developing effective reconfigurable photonic devices, low‐loss phase change materials, such as Sb ₂ S ₃ , can be a good choice. Sb ₂ S ₃ ‐tunable directional couplers (DCs) have the lowest insertion loss in both amorphous and crystalline states. However, they suffer from a large coupling length issue, which can be overcome by combining with hybrid plasmonic waveguides (HPWGs). Herein, a Sb ₂ S ₃ ‐assisted HPWG‐based reconfigurable, nonvolatile 1 × 2 switch that has been designed using an asymmetric DC is proposed. The proposed switch has dual‐polarization functionality (operates in both transverse electric and TM modes) indicating its broader applicability and flexibility in integrated photonic systems where polarization diversity is often required. The optical characteristics and coupling behavior with phase transitions have been numerically examined. With a compact coupling length of 46 μm, the proposed 1 × 2 switch achieves a low insertion loss of ≈0.5 dB and a small crosstalk of <−10 dB over a bandwidth of 70 nm (1510–1580 nm).

Mn0.5Ni0.1Zn0.4TixFe2−xO4 (x = 0.00, 0.03, 0.05, 0.07, 0.10) was synthesized using the solid-state reaction method to analyze the effects of titanium substitution on its structural, optical, magnetic, and electrical properties. Characterization techniques employed include x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), ultraviolet–visible (UV–vis) spectroscopy, PPMS, and an impedance analyzer. Rietveld refinement of the XRD data confirms that the samples adopt a spinel cubic structure (Fd3̄m space group) with the presence of secondary Fe2O3 peaks across all Ti-doped samples. The lattice parameter shows an increasing trend with an increase in Ti content. The theoretical density (ρth) and bulk density (ρB) findings reveal that ρth exceeds ρB, suggesting that pores are formed within the bulk specimens. The FTIR spectrum displays peaks at 357 and 529 cm−1, confirming the formation of metal oxide bonds at both tetrahedral and octahedral sites. UV–vis spectroscopy shows significant absorption in the UV region between 200 and 240 nm. The Tauc plot analysis reveals that the bandgap energy increases with higher Ti content. The study of the magnetic hysteresis loop shows a decrease in saturation magnetization (Ms) as Ti4+ content rises, likely due to the transition of Fe3+ ions from octahedral to tetrahedral sites and the non-magnetic nature of titanium. In addition, the dielectric constant and dielectric loss tend to decrease with increasing frequency, while resistivity increases with higher Ti concentrations. Notably, the 5% Ti doping sample exhibited high resistivity and low dielectric loss at elevated frequencies, indicating promising potential for high-frequency applications.

Nowadays, perovskite materials are well known for electronics and optoelectronics applications. We have investigated a potential candidate for those applications to compare the applicability in optoelectronics, photorefractive and photovoltaic (PV) devices. The systematic comparative study of the structural, electronic, optical, mechanical, and thermodynamic properties of pure BaTiO₃and Ca doped BaTiO₃(Ba_1−xCa_xTiO₃where x = 0.125, 0.25, 0.375, 0.500, 0.625) perovskite have been carried out using first-principles and density-functional-theory calculations as recently this material was mostly experimented. The measured structural parameters from the geometrically optimized structure of cubic BT ceramic compared with the other theoretical values. A crystal phase transition occurs when doping content x = 0.25. The electronic band structure shows that the nature of the bandgap is changed from indirect bandgap to direct bandgap energy at G-point after doping the Ca atom into BaTiO₃(BT) crystal. Doping of Ca into BT has led to bandstructure modification including conduction band (CB) shifting toward the higher energy level. Electronic properties have been reported to examine the contribution of different orbitals to the CB and to the valance band (VB). This study investigated the modification of optical properties such as absorption, reflectivity, refractive index, extinction coefficient, conductivity, dielectric function and loss function at the energy range from 0 to 30 eV. The prominent absorption peak and optical energy were observed at the UV light energy region. Based on the optical behavior of the material this theoretical research suggests that the doped BT solution is a suitable candidate for photorefractive and optoelectronic devices. Different elastic constants reveal mechanical stability and the existence of the covalent bond of those compounds. Debye temperature increases with doping content. Hence modification of BaTiO₃crystal by Ca atom significantly develop various properties that led it to multifunctional applications.

This work presents the fabrication of Zn_1−xS:Sn_xthin films using the chemical bath deposition method and investigates the effects of Sn doping and annealing temperature on the structural, optical and electrical properties of ZnS thin films. The XRD patterns show that the relative intensities of the major diffraction peaks increase with Sn dopant incorporation and annealing temperature. Because high-temperature annealing forms several nucleation centers throughout the lattice and dopant incorporation enhances point defects leading to crystallite boundary mobility enhancement, crystallinity is also improved. UV–vis-NIR spectrophotometric studies revealed that the films have good transmittance that is larger than 75% in both visible and near-infrared regions and their optical bandgap ranges from 3.34 eV to 3.90 eV. Both the Sn content and annealing temperature cause the transmittance and the optical bandgap to rise. The absorption edge shifts towards the longer wavelength for higher Sn contents and annealing temperatures. Also, the decreased Urbach energy with increased Sn content or annealing temperature can be attributed to the reduced structural disorders and dislocations of ZnS crystals that are indicated by improved crystallinity. Electrical characterization by the two-point probe method exhibits that at higher annealing temperature grain boundary scattering limits the number of mobile carriers by increasing interatomic binding. On the other hand, due to increased carrier concentration and decreased dislocations resulting from the Sn content or annealing, localized carriers dominate in the bulk crystal state and require higher activation energy to replace an interstitial atom and excite the bulk states.