Browsing by Author "Senthil Kumar, S."

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COMPARATIVE ANALYSIS OF STRENGTH BEHAVIOURS ON CONCRETE FRAMES UNDER SEVERE EARTHQUAKE LOADS
(Scibulcom Ltd., 2023) Balasubramanian, S.; Palanisamy, T.; Senthil Kumar, S.
The increase in the development of constructions and infrastructures to compensate the growing population of the world had led to the tremendous demand for concrete. Concrete has been revolutionised by Romans and its use resulted as the finest building material on earth. But as the concrete strength improves, the brittleness increases and as a result the potential for deformation decreases, thus restricting the use of concrete in seismically active areas. Hence, this paper does the experimental research and study of the strength behaviour of reinforcement concrete (RC) and high strength concrete (HSC) effectively. The main aim of this study is to improve the properties of the frame and to withstand the burdens arising from earthquake charges against seismic behaviour. The research analysis includes the design and manufacture with casting and examination of frame speci-mens. The experimental data is checked with empirical results, and the average error percentage is 4.86. The study result showed that HSC infilled frame’s overall load-bearing capability is 4.27 times higher than RC infilled frame, and also 4.48 times higher for HSC bare frame than the RC bare frame. © 2023, Scibulcom Ltd. All rights reserved.
Effect of Chloride on Accelerated Corrosion of Steel Rebar in Alkali-Activated Fly Ash and Paper Sludge Ash–Reinforced Concrete
(Electrochemical Science Group, 2022) Senthamilselvi, P.; Palanisamy, T.; Senthil Kumar, S.
The aim of this work was to investigate the corrosion of reinforcing rebar inserted in geopolymer concrete (GPC) made from fly ash (FA) containing 10% paper sludge ash (PSA) by weight under three curing conditions, namely oven curing (OC) at 60°C, external exposure curing(EEC), and curing at ambient temperature (AC). The investigation was carried out on the GPC using linear polarization resistance and Tafel plot techniques. All of the reinforced lollipop specimens were stored in a 3.5% NaCl solution with a steady anodic electrical potential of about 12 V applied to accelerate the corrosion process. Both the bond strength loss percentage and the mass loss percentage of the corroded steel rebar embedded in the concrete cylinder specimens were calculated. The test results showed that the OC condition demonstrated best corrosion resistance in the FA-GPC specimen compared to the FA-PSA GPC specimen. The test results for FA-PSA GPC specimens showed that their corrosion resistance performance was better under AC condition compared to the other two curing conditions. © 2022 The Authors. Published by ESG (www.electrochemsci.org). This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution license (http://creativecommons.org/licenses/by/4.0/).
Improving hydrogen evolution reaction and capacitive properties on CoS/MoS2 decorated carbon fibers
(Elsevier Ltd, 2020) Sangeetha, D.N.; Krishna Bhat, D.; Senthil Kumar, S.; Muthu, M.
We report a facile method to transform abundantly dumped banana stem fibers into carbon fibers (CFs) useful for energy applications. The CFs surface area is increased by varying the quantity of KOH activation to 488 m2g-1. The solvothermal method is used to synthesize CoS, CoS/MoS2 and also grown on the activated carbon fibers (ACFs). Nano nodules of CoS arranged into sheets and layers of MoS2 stacked together were found in FESEM analysis. The morphology of the CoS/MoS2 differs when grown on ACFs. The growth of CoS/MoS2 along the ACFs length prevents any stacking of the pseudocapacitance materials. The ternary composite ACFs/CoS/MoS2 exhibits superior supercapacitor behavior as well as hydrogen evolution reaction (HER) due to the synergetic effect of the conducting ACF surface and redox active CoS/MoS2. A maximum specific capacitance of 733 Fg-1, energy and power density of 33 WhKg?1 and 999 WKg-1 respectively are obtained. A low Tafel slope value of 61 mVdec?1 is obtained for the ACFs/CoS/MoS2 ternary composite electrode. The present work therefore offers a fresh insight into the effective conversion of waste materials into electrode material for energy storage and conversion applications. © 2019 Hydrogen Energy Publications LLC
Reduced graphene oxide derived from used cell graphite and its green fabrication as an eco-friendly supercapacitor
(Royal Society of Chemistry, 2014) Sudhakar, Y.N.; Muthu, M.; Bhat, D.; Senthil Kumar, S.
Graphite extracted from a used primary cell was converted into reduced graphene oxide (rGO) using calcium carbonate together with rapid and local Joule heating by microwave irradiation. Electrodes were prepared by ultrasonically dispersing rGO in biodegradable poly(vinylpyrrolidone) (PVP) binder and coating this on recyclable poly(ethyleneterephthalate) (PET) sheet using a low cost screen printing technique. The use of the same polymer (PVP) as a binder, in addition to as the solid polymer electrolyte (SPE), enhances the compatibility and ionic conductivity of the hydrophobic rGO electrode in the supercapacitor system. Further, the phosphoric acid (H3PO4)-doped biodegradable SPE was screen printed for the first time on the rGO electrodes. Ionic conductivity and dielectric studies of the SPE were carried out at different temperatures and different dopant acid concentrations. The morphology, composition and structure of the graphene electrode components were characterized using Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) methods. Transmission electron microscopy (TEM) images showed a single layer or a few layers of rGO sheets and selected area electron diffraction showed the presence of slight defects. The fabricated environmentally friendly, industrially favorable and green supercapacitor showed a specific capacitance of 201 F g-1 and cyclic stability with 97% retention of the initial capacitance over 2000 cycles. Furthermore, the performance of this green supercapacitor is comparable to that of those fabricated using rGO synthesized from commercial graphite and in other literature reports. © 2014 The Royal Society of Chemistry.