Amrita Vishwa Vidyapeetham

Speech Emotion Recognition (SER) in low-resource languages is hindered by scarce labeled data, speaker variability and prosodic diversity. Existing few-shot learning models underperform in such settings due to weak generalization and inadequate exploitation of emotional cues in speech. This study proposes SegTM-SGD, a novel meta-learning framework that integrates Whisper-derived acoustic representations with a lightweight Transformer encoder optimized using Meta-SGD. Unlike prior approaches, SegTM-SGD employs segment-level temporal modeling with learnable per-parameter adaptation, enabling rapid task transfer with minimal supervision. The framework adopts episodic N-way K-shot learning to simulate real-world data scarcity. Experiments conducted on Tamil, Malayalam, and Indian-English emotional speech datasets demonstrate significant performance gains over state-of-the-art metric- and gradient-based baselines. SegTM-SGD achieves macro F1-scores of 0.90, 0.83, and 0.92 in 1-shot settings, improving to 0.95, 0.94, and 0.96 under 10-shot conditions, respectively. These results highlight the effectiveness of segment-aware transformer refinement with adaptive meta-learning for few-shot SER in multilingual low-resource environments.

A steadily growing need for efficient energy storage systems has positioned supercapacitors as an innovative technology. Conventional supercapacitor materials have low energy density compared to batteries, limited electrolyte stability and capacitance loss over prolonged operation. Polymer nanocomposites have gained attention as a solution to these drawbacks to a certain extent but still face challenges like poor filler dispersion and weak interfacial bonding. One efficient way to get around these obstacles is to employ functionalized nanofillers in polymer nanocomposites. This review briefly discusses various classes of nanofillers, their functionalization, along with fabrication techniques of functionalized polymer nanocomposites. A detailed discussion is presented on the effect of functionalized nanofillers in polymer matrices on supercapacitor performance parameters, such as specific capacitance, power density, and long-term cyclic stability. Among the reported nanofiller systems, graphene and its derivatives were the most extensively investigated, followed by carbon nanotubes and carbon quantum dots, while polyaniline and polypyrrole dominate as the preferred polymer matrices. A wide range of emerging nanomaterials and polymer matrices have received comparatively limited attention. This review provides a comprehensive overview of the performance of functionalized polymer nanocomposites for advanced supercapacitor applications and provide an outline for future research and development strategies.

In the pursuit of sustainable materials for next-generation energy storage, the coconut palm represents a uniquely circular biomass system capable of delivering both hard and soft carbons from a single plant source. The components exhibit distinct lignin-to-cellulose ratios, which critically determine carbon purity, graphitizability, and electrochemical behavior. This review consolidates the current understanding of coconut-derived carbons with a focus on their structural evolution during carbonization and activation, the resulting pore architectures, and their performance in batteries and supercapacitors. Hard carbons derived from cellulose-rich precursors exhibit disordered microstructures with high durability and ion-storage capability, while lignin-rich components yield soft, partially graphitized carbons offering superior conductivity and rate performance in supercapacitors. The effects of carbonization temperature, activating agents, and electrolyte composition on pore distribution, surface functionality, and charge-storage mechanism are systematically analyzed. These carbons can have surface areas up to 3000 m2·g− 1, specific capacitances up to 600 F·g− 1 in supercapacitors, and battery capacities up tp 292 mAh·g− 1. Beyond performance, the study highlights the global potential of coconut palm waste, which is estimated at 15 Mt y− 1 carbon yield, as a low-carbon feedstock for high-value electrochemical materials. By linking compositional chemistry with electrochemical function, this review underscores coconut palm as a scalable, sustainable and renewable carbon resource for developing circular energy-storage technologies.

Carbon-Carbon (Cf-C) composites are widely used in aerospace and nuclear applications due to their low density, excellent thermal stability, and superior mechanical properties. However, joining Cf-C to metals, ceramics, or itself remains challenging due to poor wettability and a large coefficient of thermal expansion (CTE) mismatch, leading to residual stresses, interfacial reactions, and joint degradation. Brazing has emerged as a promising solution with the use of active filler alloys. This review compares different filler systems based on wettability and performance. Al, Ag, and Cu-based fillers provide moderate joint strength ( 20–50 MPa) but are suitable for lower-temperature applications. In contrast, Ni and Ti-based fillers provide higher strength ( 50–70 MPa) and improved thermal performance (up to 900 °C), although residual stresses and interfacial brittleness remain key challenges. In addition, recent approaches, such as particle-reinforced fillers and interlayer coatings, have shown potential in reducing residual stresses and improving joint reliability. This review highlights the relationships between filler composition, microstructure, wettability, and mechanical performance, and outlines current limitations and future directions for developing advanced brazing fillers for Cf-C composite joining. This review comprehensively analyzes the challenges, filler design strategies, and interfacial mechanisms involved in brazing carbon-carbon (Cf-C) composites with self and dissimilar materials. It compares the performance of Al-, Ag-, Cu-, Ni-, and Ti-based fillers in terms of wettability, phase formation, shear strength, and oxidation resistance. The study highlights the critical role of interfacial reactions, residual stresses, and carbide layer formation in determining joint integrity. Recent advancements using particle-reinforced fillers and stress-relief interlayers show significant potential for enhancing wetting and long-term thermal reliability of Cf-C brazed joints.

Recently, the bioactive polysaccharides have not been extensively explored for development of bioactive wound dressing. Hence, moringa gum has been utilized to develop the hydrogel by graft copolymerization of poly(2-hydroxyethylmethacrylate phosphate) in the presence a multifunctional crosslinker for use in drug delivery (DD) application. The hydrogel were characterized by FESEM, EDS, AFM, XRD FTIR, solid state 13C-NMRand TGA and DSC. The DD, wound sorption, biocompatibility, antioxidant, mucoadhesion, and antibacterial properties along with mechanical and oxygen/water permeability aspects. The sustained delivery of minocycline from hydrogel governed by a non-Fickian diffusion mechanism release data was best described by first-order kinetic model. The one gram dressings retained 5.59 ± 0.24 g of wound fluid, which is beneficial in preserving a moist surrounding for efficient wound healing. The dressing materials exhibited antioxidant activity quantified as 74.67 ± 1.35 µg gallic acid equivalentsby the F-C assay. The material illustrated notable mucoadhesion and required detachment force of 153.00 ± 13.00 mN from the mucosal surface for its separation. The hydrogels elucidated biocompatibility observed from minimal hemolytic effect, indicating safe interaction with the biological system. Hydrogel dressing expressed antibacterial properties that significantly enhanced after drug encapsulation. Further, the web-like network structure was permeable to the diffusion of water vapor and oxygen. The findings of various physicochemical and biomedical properties suggested their suitability for use as wound dressing materials.