Faculty Publications

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    Performance evaluation of PV panel under dusty condition
    (Diponegoro university Indonesia - Center of Biomass and Renewable Energy (CBIORE), 2017) Tripathi, A.K.; Mangalpady, M.; Murthy, C.S.N.
    The performance of PV panel depends on the incoming sunlight on its surface. The accumulated airborne dust particles on panel surface creates a barrier in the path of sunlight and panel surface, which significantly reduces the amount of solar radiation falling on the panel surface. The present study shows a significant reduction in short circuit current and power output of PV panel due to dust deposition on its surface, whereas the reduction in open circuit voltage is not much prominent. This study has been carried in the field as well as in the laboratory. The reduction in maximum power output of PV panel for both the studies ensures a linear relation with the dust deposition on its surface. In the field study, the reduction in the power output due to 12.86gm of dust deposition on the panel surface was 43.18%, whereas in the laboratory study it was 44.75% due to 11gm of dust deposition. © IJRED.
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    Influence of Gd on the microstructure, mechanical and shape memory properties of Cu-Al-Be polycrystalline shape memory alloy
    (Elsevier Ltd, 2018) Bala Narasimha, B.N.; Murigendrappa, S.M.
    In the present study, the influence of rare earth element gadolinium (Gd) on Cu-Al-Be polycrystalline shape memory alloy has been investigated. Cu 88.13 Al 11.42 Be 0.45 ternary alloy with addition of Gd from 0.05 to 0.15 wt% has been used for investigation. The tests have been carried out for microstructure, morphology, ductility, phases, crystal structure, phase transformation temperatures and shape recovery ratio. Refinement of the grain size resulted as gadolinium increased from 0 to 0.08 wt%, the grain size decreases from 463.45 to 81.80 µm with reduction of 82.34%. The tensile strength has increased from 398.93 to 581.42 MPa with improvement in the ductility from 10.05% to 23.72% at 0.08 wt% gadolinium. The phase transformation temperatures increases as gadolinium increases and reduction in shape recovery ratio from 97% to 65%. © 2018 Elsevier B.V.
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    Effect of zirconium on the properties of polycrystalline Cu-Al-Be shape memory alloy
    (Elsevier Ltd, 2019) Bala Narasimha, G.; Murigendrappa, S.M.
    This paper presents an investigation of the effect of zirconium on the properties of polycrystalline Cu-Al-Be shape memory alloy. Mechanical and shape memory properties have been evaluated by varying the compositions of Zr to Cu88.13-Al11.42-Be0.45 alloy ranging from 0.05 to 0.4 wt% with step 0.1 wt%. The results unveil reduction in the grain size of 89.18% with the improved tensile strength of 667 ± 30 MPa and ductility of 23.95 ± 0.86% and excellent shape recovery ratio of 100% with the addition of Zr up to 0.3 wt%. Increase in transformation temperatures is observed with the addition of Zr. © 2019 Elsevier B.V.
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    Numerical investigation of cooling performance of a novel air-cooled thermal management system for cylindrical Li-ion battery module
    (Elsevier Ltd, 2021) Kausthubharam, n.; Koorata, P.K.; Chandrasekaran, N.
    Batteries strongly influence the performance of electric vehicles. Therefore it is crucial to develop a battery thermal system that is highly efficient in removing the battery pack's heat during its operation. In this paper, a numerical analysis of a lumped thermal model coupled with fluid flow equations is employed to investigate the novel air-cooled battery thermal management system (BTMS). The cooling efficiency of the proposed battery thermal system with commercial thermal interface material (3M™) is investigated by comparing it with a standard battery pack at different discharge rates. The proposed solution offers a 25% reduction in peak temperature when compared to the standard one. The thickness of the thermal interface material is found to have an insignificant impact on the battery pack's thermal performance. Introducing forced air-cooling in the battery pack reduced the maximum temperature considerably but increased the temperature difference compared to the battery pack without forced convection. Then the effect of various structural and operational parameters on the performance of the BTMS is investigated. Moving the air inlet-outlet boundaries to a central location increased the uniformity of temperature distribution in the battery pack. Although the increase in the inlet airflow velocity reduces the maximum temperature, it comes at the cost of an increase in temperature difference and power consumption. It is further observed that a reduction in ambient temperature reduces the peak temperature and makes the temperature distribution in the battery pack more homogeneous. The discharge voltage curves indicate a slight reduction in cell potential as a reducing function of temperature. © 2021 Elsevier Ltd
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    Fabrication of visible-light assisted TiO2-WO3-PANI membrane for effective reduction of chromium (VI) in photocatalytic membrane reactor
    (Elsevier B.V., 2021) Rathna, T.; JagadeeshBabu, J.; RubenSudhakar, D.
    In this work, TiO 2-WO3(40:1) nanoparticles were hydrothermally prepared and, embedded in Polyaniline (PANI) membrane with varying concentrations (3–7 wt%) and, used in photocatalytic membrane reactor for the removal of Cr(VI) from the aqueous solutions. 4-methyl piperidine (4-MP) was used as a gel inhibiting agent in N-methyl-2-pyrrolidone (NMP) solvent to prepare PANI-based flat-sheet membranes by phase inversion method. Through different characterization technique, it has been found that TiO 2-WO3 incorporated PANI membranes showed enhanced membrane properties like better hydrophilicity, better antifouling properties, higher water uptake, lower contact angle, higher porosity, and better heavy metal removal efficiency compared to bare PANI membranes. PANI membrane with 5 wt% TiO 2-WO3 exhibited a percentage rejection of 98.50% within 60 min at 0.5 MPa transmembrane pressure. Cr(VI) reduction under light and dark conditions was performed in a dead-end filtration cell with a quartz window at the top and the 5 wt% TiO 2-WO3– PANI membrane showed 67.32% reduction under visible light. TiO 2-WO3 incorporated PANI nanofiltration membranes can act as an integrated system consists of a short-circuited photo-anode and cathode under visible light irradiation. Overall, TiO 2-PANI membranes promote Cr(VI) reduction to Cr(III) in the photocatalytic membrane reactor and exhibits a better self-cleaning property. © 2021
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    Experimental investigation of shellac wax as potential bio-phase change material for medium temperature solar thermal energy storage applications
    (Elsevier Ltd, 2022) B.V., B.V.; Thanaiah, K.; Gumtapure, V.
    Thermal performance of shellac wax as a novel bio-phase change material (BPCM) and Therminol®-55 as heat transfer fluid (HTF) in a vertical shell and tube latent heat thermal energy storage (LHTES) unit is analyzed experimentally. Operational parameters considered, namely HTF flow rate and inlet temperature in the range of 2–5 LPM and 100–120 °C, respectively. The comprehensive study of contours and plots reveals the impact of natural convection and the progress of the melting and solidification front in the charging and discharging process. As the HTF flow rate increases, the charging rate improves considerably, and a maximum reduction in melting time is obtained as 43.6% for 4 LPM. The maximum reduction in melting time and storage efficiency are 42.2% and 73.4%, respectively, at 120 °C and 4 LPM. However, the discharging process's increased flow rate has no significant effect on solidification and discharge efficiency, which attributes the dominant mode of heat transfer is conduction during the solidification. Shellac wax storage efficiency is comparable to existing paraffin wax, stearic acid and palmitic acid-based LHTES unit. In this regard, shellac wax can be a potential Bio-PCM for medium temperature range (60–80 °C) solar thermal applications such as domestic water heating and food drying. © 2021 International Solar Energy Society
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    Synthesis, Characterization and Performance Evaluation of TiO2-SnO2 photocatalyst for Removal of Toxic Hexavalent Chromium
    (Springer Science and Business Media Deutschland GmbH, 2022) Rathna, T.; JagadeeshBabu, J.B.; Ruben Sudhakar, D.R.
    Heavy metal pollution bears a substantial threat to flora, fauna, humans, and milieu. The elimination of hexavalent chromium [Cr(VI)] from polluted water is of considerable research interest from a health and environmental viewpoint. This work aims for photocatalytic reduction of Cr(VI) to Cr(III) using TiO2 and SnO2 as catalysts. The process parameters varied are catalyst dosage, pH, initial concentration of model pollutant with citric acid (CA) as a scavenger. TiO2-SnO2 (in the molar ratios 10:1, 20:1, 30:1, and 40:1)-based catalysts were synthesized using the hydrothermal method. The 40:1 catalyst showed higher photoactivity than other catalysts and could extend the optical activity in the visible light region. The complete reduction of Cr(VI) with a concentration of 15 mg/L and pH 3.0 was achieved when catalyst concentration was 0.6 g/L over a period of 30 min. The XRD (X-Ray Diffraction Spectroscopy) and ATR-FTIR (Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy) results confirm the Ti-Sn heterojunction formation, and XPS (X-ray Photoelectron Spectroscopy) analysis corroborate the presence of trivalent chromium [Cr(III)] on TiO2-SnO2 catalyst after reduction. © 2022, The Author(s), under exclusive licence to Springer Nature Switzerland AG.
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    Effective photoelectrocatalytic reduction of CO2to formic acid using controllably annealed TiO2nanoparticles derived from porous structured Ti foil
    (Elsevier Ltd, 2022) Mubarak, S.; Dhamodharan, D.; Byun, H.-S.; Arya, S.B.; Pattanayak, D.K.
    The rate of global warming and unfavorable climate changes caused by the drastic upsurge of carbon dioxide (CO2) emission has necessitated the development of approaches to limit the significantly high concentration of CO2 in the atmosphere. The photoelectrochemical reduction of CO2 results in a reduction of the energy required to transform this greenhouse gas into valuable end products. In this study, we fabricated cost-effective and novel 3D nanoporous structured (3DNS) TiO2 nanoparticles (T-NPs) on the surface of a thin titanium foil (T-foil) by chemical treatment with hydrogen peroxide (H2O2) followed by calcination at high temperatures in the range of 400-800 °C. The as-proposed samples were analyzed by several characterizations such as XRD, XPS, TEM, and Raman spectroscopy. At 600 °C, the anatase-dominated mixed phases of calcinated T-foil (TO600) were seen, and a maximum photocurrent density of 71.5 μA/cm2 was obtained, in comparison to the T-foils treated at other temperatures (TO400, TO500, TO700, and TO800). Because of the better photocurrent density, TO600 was selected as the photocathode material for photoelectrochemical CO2 reduction performed with or without the presence of solar light. The lowest CO2 reduction onset potential (-1.191 V) was observed on the TO600 sample in the presence of light with Ag/AgCl as the reference electrode. 1H NMR analysis of the product solution revealed the formation of formic acid as the major product of the CO2 reduction reaction after the chronoamperometric electrolysis was performed for more than 25 h. The maximum faradaic efficiency (64%) and formic acid yield (165 μmol cm-2 h-1) were obtained at an applied potential of-1.3 V (vs. Ag/AgCl reference electrode) for TO600. © 2022 Elsevier Ltd.
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    Probing the synergistic effects of rutin and rutin ester on the oxidative stability of sardine oil
    (Springer, 2022) Chandrasekar, V.; Arunachalam, S.S.; Hari, H.; Shinkar, A.; Belur, P.D.; Iyyaswami, R.
    Multicomponent antioxidant mixture is proved to be highly effective in imparting oxidative stability to the edible oil. It is believed that the high efficacy of those mixtures is due to the synergistic effect exhibited by two or more components. The current study aims to analyse the synergistic effect of a flavonoid and its corresponding ester in improving the oxidative stability of n-3 PUFA rich sardine oil. The oxidative stability of rutin, esterified rutin and their combinations at three different concentrations was studied in sardine oil stored at 37 ºC for 12 days in contact with air under darkness. The combination of rutin and rutin ester showed maximum reduction of 54.2% in oxidation at 100 mg/kg and 150 mg/kg. Perhaps this is the first report on the synergistic effect of a flavonoid and its lipophilized ester for improving the oxidative stability of n-3 PUFA rich oil. © 2022, Association of Food Scientists & Technologists (India).
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    Investigating bus stops' influence on saturation flow at signalized intersections in heterogeneous traffic
    (Aracne Editrice, 2022) Shubhashree, K.S.; Mohan, M.
    The public transportation system efficiently reduces congestion and pollution as they lessen the dependency on personalized modes. However, most bus stops are located close to the intersection, and the stopping buses often create a bottleneck. At signalized intersections, this will seriously impact the saturation flow as it hinders the efficient functioning of the traffic signal system, resulting in delays and reduction of the intersection's capacity. Hence, a profound understanding of the factors associated with bus stoppages, which influence the saturation flow, is essential in designing efficient signalized intersections. This study simulates traffic flows at signalized intersections in heterogeneous traffic in a micro-simulation software VISSIM. Results of multiple simulation run indicated that saturation flow at intersections depends on the percentage of buses in the vehicular mix, the distance of bus stop from the stop line, and percentages of right and left-turning traffic. Further, the study proposes separate saturation flow models for upstream and downstream bus stop conditions. These could be used to optimally place bus stops near the intersection such that it does not hamper the performance of the intersection while not causing any undue discomfort to the bus passengers. © 2022, Aracne Editrice. All rights reserved.