Mahatma Gandhi College

Existing magneto‑photo‑thermoelastic models for semiconductor media typically treat key effects in isolation, and therefore cannot simultaneously represent microstructural porosity, long‑range nonlocal stress interactions, and memory‑dependent thermal transport. This limitation hinders realistic prediction of coupled heat, deformation, and carrier dynamics in advanced semiconductor structures. This study develops a unified analytical framework to quantify the coupled magneto‑photo‑thermoelastic response of porous semiconductor cylinders while accounting, in a single formulation, for porosity, nonlocal elasticity, and thermal memory, while preserving finite thermal‑wave propagation. Nonlocal elasticity is integrated with a memory‑dependent three‑phase‑lag (3PL) heat‑conduction theory, and the Moore–Gibson–Thompson (MGT) equation is included to ensure finite thermal‑wave speeds under strong multi physics coupling. The resulting governing equations are solved in the Laplace domain, and time‑domain responses are obtained via numerical Laplace inversion. Parametric simulations are performed in Wolfram Mathematica. The computed fields show pronounced sensitivity to the governing physical parameters. In particular, porosity and the nonlocal length‑scale parameter strongly affect thermal stress and carrier‑density distributions, producing distinct shifts in response trends as these parameters vary. The memory‑dependent formulation also enables improved modulation of the coupled thermo‑mechanical wave profiles. By unifying porosity, nonlocality, and thermal memory in a finite‑speed transportmodel, the proposed framework resolves an important multiphysics modeling gap and provides a versatile basis for the analysis and design ofsemiconductor‑based technologies such as energy‑harvesting systems, optoelectronic devices, and precision thermal‑management applications.

The prevalent TiO2 photocatalysts have some glaring limitations, viz., (i) their inactivity under visible light irradiation and (ii) the irreversible temperature-dependent transformation of photocatalytically active anatase phase into inactive rutile. In this study, we employed a facile method to develop visible-light sensitive coloured rutile photocatalysts to tackle these issues. Here, we executed a surface modification technique on sol-gel derived, crystalline rutile TiO2 using sodium borohydride (NaBH4). This was done in favourable atmospheric conditions, rendering it cost-effective and scalable. A series of rutile TiO2 samples, with colour varied from white to black, were prepared by changing the amount of NaBH4. Surface-modified samples exhibited crystalline core and disordered shell heterostructure. The pristine rutile sample was rich in Ti3+ and doubly charged oxygen vacancy V-o(++), respectively corresponding to shallow and deep defect states. In contrast, the surface-modified samples are rich in photocatalytically active shallow-trapped surface Ti3+ and singly charged oxygen vacancy (V-o(+)) defects, which act as colour centers. Hence, the photocatalytic activities of the surface-modified rutile TiO2 enhanced significantly upon white LED irradiation. Amongst a series of surface-modified samples, rR3 (treated with 0.1 g of NaBH4) showed the highest visible-light photocatalytic degradation rate constant (10.35 x 10(-3) min(-1)) for methylene blue (MB) dye. In addition to MB, sample rR3 showed better degradation of rhodamine B (RhB) and phenol than the pure rutile and commercial photocatalyst Degussa P25 under visible-light irradiation. Since rutile is the thermodynamically stable form of TiO2, surface-modified samples could be effective in hightemperature applications, especially without the assistance of regularly utilized UV radiation.

The increasing demand for effective energy storage solutions has spurred research into innovative materials with exceptional properties. Among these, two-dimensional (2D) materials have become popular alternatives due to their unique mechanical, chemical, and electrical characteristics. This review highlights recent advances in using 2D materials-such as graphene, MXenes, and transition metal dichalcogenides (TMDs) for energy storage devices like batteries and supercapacitors. Graphene, known for its high conductivity and surface area, enhances charge storage when used as an anode. MXenes, a newer class with variable compositions, provide high capacitance for both anodes and cathodes. The large surface area and capacitance of graphene, along with the flexibility of MXenes, offer promising advantages. Additionally, combining 2D materials with carbon nanotubes and metal nanoparticles further improves storage performance. New hybrid architectures and composites that incorporate 2D materials optimise energy storage devices, increasing metrics such as energy density and cycling stability. Moreover, integrating 2D materials into flexible, wearable devices addresses the needs of portable electronics and IoT. The review links the structure, synthesis, and characterisation to the electrochemical behavior of each material and also captures recent advances in the last decade related to battery and supercapacitor applications. In addition, the review includes two tables that compare the performance of each type of material as well as an increased focus on emerging hybrid structures for next-generation energy storage systems.

This study presents a novel semi-analytical framework for modeling the hygro-thermoelastic response of infinite porous cylinders under environmental loading. Unlike conventional models, the proposed formulation uniquely integrates several advanced physical mechanisms: a tunable memory-dependent transport law with customizable kernel functions (uniform, exponential, and polynomial), Eringen-type nonlocal elasticity to capture long-range microstructural interactions, dynamic porosity evolution coupled with stress, temperature, and moisture fields, and the explicit inclusion of cross-diffusion effects (Dufour and Soret). The problem considers an axisymmetric porous solid cylinder subjected to coupled hygro-thermal-mechanical loads. The solution methodology employs the Laplace transformation and Bessel function expansions, with numerical inversion carried out via the fixed Talbot contour. Key findings reveal that the choice of memory kernel significantly influences the distributions of temperature, moisture, displacement, and stress, while the nonlocal parameter smooths field gradients and delays peak responses. The model provides a unified platform for benchmarking porous media behavior, with direct applications in the design and optimization of thermal insulation systems, biomedical implants, and microstructured devices. This fully coupled approach, in which memory-dependent transport, nonlocal stress, and dynamic porosity evolution are solved simultaneously within a single governing system, has not been previously reported and offers new avenues for experimental validation and multiphysics simulation.

Localised approaches can bring about significant changes in how climate solutions are formulated and implemented. In this context, the state of Kerala is implementing a decentralised waste management initiative called Haritha Karma Sena under Haritha Kerala Mission. It serves as an excellent example of sustainable practice and job creation. The Haritha Karma Sena in Kerala employs an innovative approach to climate conservation through community-based waste management and environmental initiatives. Notably, women's active participation in the Sena highlights the potential for inclusive, community-driven climate action. This study examines the role of local initiatives in climate protection and analyses how it would result in the formulation of sustainable climate strategies at the global level. Keywords: Haritha Karma Sena, Community Participation, Sustainable Climate Protection Strategy, Local Initiatives, Climate Protection, Women Empowerment, Waste Management