Faculty Publications

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    Experimentation and Prediction Analysis on the Mechanical Performance of Fish Scale and Coconut Shell Powder-Based Composites
    (Taylor and Francis Ltd., 2022) Lokesh, L.; Shanmugam, B.K.; Mayya D, S.; B.p, P.; Naveen Kumar, N.; Hanumanthappa, H.
    In India, the utilization of natural fibers for developing new composites with desirable properties has been increasing from the last decade. Bio-waste such as fish scale and coconut shell (CS) powder was utilized to develop natural fiber-based composites in the present work. Three composite specimens, i.e., 30 wt% fish scale (FS), 30 wt% CS powder (CS), and 5 wt% fish scale (FS)+ 5 wt% CS powder specimen, were developed. The tensile, flexural, and impact strength testing was carried out on each specimen. A comparative study was drawn between the test results of the specimen. The experimental results showed that the CS powder-based composites yield improved mechanical properties compared to the fish scale-based composites. Furthermore, a quadratic and cubic mathematical model was developed on the experimental results of tensile and flexural testing for each specimen. The regression results show that the cubic regression model yields better prediction results than the quadratic regression model for all the composite specimens. The experimental results showed that the largely available fish scale and CS powder could be used to produce biowaste-based value-added material that provides a sustainable and eco-friendly approach. © 2021 Taylor & Francis.
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    Preparation and structural characteristics of biphasic calcium phosphates from prawn shell bio-waste
    (Taylor and Francis Ltd., 2023) Satish, P.; Salian, A.; Hadagalli, K.; Mandal, S.
    The major objective of the work is to explore the mechanical properties of biphasic calcium phosphates (BCP), a biomaterial derived from marine resources like prawn (Fenneropenaeus Indicus) shell biowaste through wet chemical treatment of CaO. We report the BCP, a mixture of hydroxyapatite and octa calcium phosphate from prawn shell biowaste using wet chemical synthesis at 80°C under pH 10. XRD of BCP revealed the coexistence of secondary phases like β-TCP and α-TCP along with HA upon sintering at different temperatures. Furthermore, the SEM and EDS opened well-sintered uniaxial grains and the presence of trace elements like Fe, Mg, Si, and Na. The specimens sintered at 1100°C showed the highest compression strength of 56.8 MPa due to MgO at the grain boundaries, which plays an important role in grain boundary diffusion. Therefore, the prawn shell biowaste-derived BCP has good mechanical properties, making them suitable materials for high-strength bone substitutes. © 2023 Institute of Materials, Minerals and Mining. Published by Taylor & Francis on behalf of the Institute.
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    Recycling waste plastics and biowaste into high-performance NiCo-MOF/activated carbon electrocatalyst for overall water splitting
    (Elsevier Ltd, 2025) Nayak, M.P.; Rao, L.; Rodney, J.D.; S, S.; Rohit, A.G.; Badekai Ramachandra, B.R.
    Environmental and energy crises are the most significant global challenges. Developing non-precious and environmentally sustainable electrocatalysts remains critical for advancing renewable hydrogen production. This study presents a novel hybrid electrocatalyst comprising a NiCo-BDC Metal-Organic Framework (NiCo-MOF), where the BDC (Benzene 1,4-di carboxylic acid) ligand was obtained by recycling waste poly(ethylene terephthalate) (PET) bottles, integrated with activated carbon (AC) derived from dried drumstick (Moringa olifera) biowaste, via a one-pot hydrothermal method. The research emphasizes optimizing the AC content within the MOF matrix to enhance catalytic performance. The synergistic interaction between NiCo-MOF and AC significantly reduces the overpotentials required for the Hydrogen Evolution Reaction (HER) and Oxygen Evolution Reaction (OER) in an alkaline medium. Notably, the optimized composite, NiCo-MOF@40AC, exhibited enhanced crystallinity, BET surface area, and electrocatalytic activity. At a current density of 100 mA cm?2, NiCo-MOF@40AC achieved overpotentials as low as 217 mV for HER with a Tafel slope of 105.6 mV dec?1 and 315 mV for OER with a Tafel slope of 42.2 mV dec?1. Furthermore, this material demonstrated robust stability over a 24 h chrono potentiometric test, maintaining performance at an elevated current density of 200 mA cm?2. In a two-electrode system, NiCo-MOF@40AC needed only 1.58 V to sustain a current density of 10 mA cm?2, exhibiting stability over 48 h and 24 h at a current density of 10 mA cm?2 and 400 mA cm?2, respectively. An average faradaic efficiency was found to be 93.48 % for HER and 91.91 % for OER. These findings highlight the potential of NiCo-MOF@40AC as an efficient electrocatalyst, characterized by a high surface area, rapid electron transfer, favorable structural properties, and enhanced reaction kinetics. © 2025 Hydrogen Energy Publications LLC