Gandhi Institute for Technology

The growing shift toward sustainable and biodegradable materials has accelerated research on natural fiber-reinforced materials as eco-friendly substitutes for synthetic polymer composites. The current study aims to develop and characterize environmentally friendly biocomposites using Palmyra fiber (Borassus flabellifer L.) as reinforcement and Kondagogu gum (Cochlospermum gossypium) as a natural bio-based matrix for potential lightweight and sustainable engineering applications. To evaluate the effect of fiber surface modification on composite performance, the composites were fabricated using the hand lay-up technique with fiber loadings of 5 wt%, 10 wt%, and 15 wt%, incorporating both untreated and treated fibers. Mechanical, thermal, physical, and morphological characterizations were systematically carried out using tensile, flexural, and impact testing, Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), and Scanning Electron Microscopy (SEM). The results demonstrated that alkali treatment significantly enhanced fibre-matrix interfacial adhesion and overall composite performance. At the optimum fibre loading of 15 wt%, the alkali-treated composites exhibited a 27% improvement in tensile strength, a 61.51% increase in flexural strength, and a 31.6% enhancement in impact resistance compared with untreated composites. FTIR analysis confirmed the partial removal of hemicellulose and impurities after alkali treatment, while TGA results revealed improved thermal stability. SEM observations further confirmed stronger interfacial bonding, improved fiber dispersion, and increased surface roughness in the treated composites. The enhanced mechanical and thermal properties highlight the significance of alkali treatment in developing high-performance green composites. These findings demonstrate that PF/KGG biocomposites possess strong potential for use in biodegradable packaging and lightweight sustainable engineering applications, offering an environmentally benign alternative to conventional synthetic composites.

Abstract Titanium alloys such as Ti–6Al–4V and Ti–3Al–2.5V are commonly utilized in the aerospace industry and medical sectors, but their low surface hardness and poor wear resistance may reduce their service life. In this study, CrN thin-film coatings were deposited on both alloys using RF magnetron sputtering to investigate the influence of substrate composition on coating microstructure, crystallinity, nano-mechanical behavior, and scratch resistance. The coatings were characterized using 3D profilometry, field emission scanning electron microscopy/energy dispersive x-ray spectroscopy, x-ray diffraction (XRD), nanoindentation, and scratch testing. Dense and uniform CrN coatings with an average thickness of approximately 460 nm were successfully obtained. XRD confirmed the formation of single-phase crystalline CrN, while the coating on Ti–3Al–2.5V exhibited broader diffraction peaks, indicating substrate-dependent differences in crystallinity. Nanoindentation showed a significant increase in hardness from 6.01 to 12.57 GPa for Ti–6Al–4V (109.2% increase) and from 6.77 to 16.49 GPa for Ti–3Al–2.5V (143.6% increase). The residual indentation depth decreased by 36.3% for CrN G5 and 61.3% for CrN G9, indicating improved resistance to permanent deformation and enhanced elastic recovery. Scratch testing demonstrated good adhesion for both coatings, with critical loads of 372 and 532 mN for CrN G5 and 428 and 476 mN for CrN G9. The coating on Ti–3Al–2.5V showed better resistance to crack initiation, whereas the coating on Ti–6Al–4V exhibited greater resistance to crack propagation. Overall, RF-sputtered CrN coatings significantly improved the nano-mechanical performance and scratch resistance of both titanium alloys, highlighting the important role of substrate composition in determining coating behavior.

Telemedicine demands watermarking schemes that can secure diagnostic images while preserving clinical readability. This paper proposes a blind mid-band DCT watermarking framework in which the scaling factor $\alpha$ is automatically tuned by a sequential hybrid of the Firefly Algorithm (FA) and Particle Swarm Optimization (PSO). FA first performs wide stochastic exploration of the scaling-factor space, and PSO then refines around the best region to obtain an optimal $\boldsymbol{\alpha}^{*}$. Watermark bits are embedded into pseudo-randomly selected $\mathbf{8} \times \mathbf{8}$ DCT mid-band coefficients using a secret key, and repetition coding with majorityvote decoding enhances blind recovery under distortions. Experiments on CT and X-ray images show that the hybrid FA-PSO strategy consistently produces low-strength embeddings that achieve PSNR of 60-65 dB and SSIM above 0.9999, clearly outperforming both standalone FA/PSO and six recent benchmark methods. Robustness tests under JPEG compression, Gaussian noise, and median filtering maintain NCC values above 0.87, indicating reliable watermark extraction and demonstrating the suitability of the proposed scheme for secure telemedicine environments.

Iron ore beneficiation plant tailing (IOBT) is a common voluminous solid waste found at iron ore mining and mineral beneficiation sites. It is found commonly in granulated form with suitable grading. With appropriate test procedure conforming to relevant standard code, the waste is found to be suitable for replacing river sand, a natural resource as fine aggregate in concrete work. Slump and compaction factor values remain within the medium range so that it may be used general purpose concrete work. Strength values like compressive strength, split tensile strength and flexural strength values by and large meet the requirement at all replacement level. However the optimum values for both fresh and hardened properties of concrete are found to be at 50

Plastics are essential to modern life, consisting primarily of non-biodegradable polymers made from carbon, hydrogen, and occasionally elements like chlorine and nitrogen. The rapid growth of the global population has increased the demand for commodity plastics, due to its diverse applications. The world is now grappling with the challenge of effectively managing and recovering resources from the vast amount of plastic wastes. To prevent environmental pollution from plastic wastes, recycling and recovery are essential. The depletion of fossil fuels and rising energy demand has driven research into alternative energy sources. Plastics, due to their petrochemical origin and high calorific value, are well-suited for energy recovery. The fuels extracted from waste plastics by pyrolysis with regard to various inclusions of fuel additives have a significant effect on mitigating the pollutants from engine emissions. This study combines waste plastic fuel production with ethanol, nanographene, and biogas additives, optimizing engine performance and emissions. An environmental pollution cost analysis was conducted for WPO blended with ethanol, nanographene, and biogas under optimized engine conditions. The study showed notable reductions of CO by 0.06 % for 20WPO, 11.53 % for 20W20E as compared to diesel and other fuel mixtures. Similarly, HC and NOx were found reduced by 2.5 % for 20W20E as compared to diesel. The concentration of CO2 for 20W20E was also reduced by 1.9 % as compared to diesel. 20W20E has lowest environmental cost (2.7305 x 10-4 kg/kJ), shortest payback (0.6665 yr), and highest energy payback (9.1713 yr), showing the best environmental and economic balance. The 20W20E blend showed the best overall performance across all load conditions.