Faculty Publications
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Item Towards a Greener Extraction: Renewable Energy Initiatives in India's Mining Industry(Institute of Electrical and Electronics Engineers Inc., 2024) Bojja, S.K.; Kunar, B.M.; Rajendhar, R.The main objectives of using renewable energy in India are to advance economic growth, enhance power reliability, increase access to electricity, and lessen the consequences of global warming. Utilizing sustainable energy and ensuring that all residents have access to reliable, inexpensive, environmentally friendly, and contemporary amenities enable sustainable development. Due to strong government support and an improving economic climate, India is rising to the top of the list of the most promising markets in the world for renewable energy. The administration has developed open-minded guidelines, approaches, and a setting that welcomes foreign investment and advances the nation's green energy industry. This essay discusses significant advancements in India's use of renewable energy, including prospects, projections, electricity production and challenges. This study recognized the considerable challenges that the renewable energy industry faces as well as how renewable energy affects the mining sector. Mining businesses are switching to non-fossil fuels in order to lessen their carbon footprint. Policymakers, entrepreneurs, project developers, investors, businesses, appropriate parties-related scholars, and experts will find the suggestions based on the evaluated results. © 2024 IEEE.Item Evaluation of properties of nonfoaming Warm mix asphalt mixtures at lower working temperatures(American Society of Civil Engineers (ASCE) onlinejls@asce.org, 2017) Shiva Kumar, G.; Suresha, S.N.Warm mix asphalt (WMA) is a green technology which has the potential to replace hot mix asphalt (HMA) because it reduces greenhouse gas emissions and energy consumption by lowering the temperature at which asphalt mixtures are produced and placed. During the design process, evaluation of the mix design and mechanical properties of WMA mixtures is necessary. Therefore, the ability to quantify compactability would be very useful. This paper presents details on the evaluation of asphalt mix design, workability, and mechanical properties of asphalt mixtures modified with nonfoaming WMA additives at lower working (mixing and compaction) temperatures. Further, it seeks to provide a wider gap between mixing and compaction temperatures to ensure that WMA mixtures are suitable for longer haul distances. Asphalt mix design properties were evaluated by the Superpave method for various design gyrations (Ndes), and workability properties were evaluated in terms of Superpave gyratory compactor (SGC) densification indices using the Bahia and locking point methods. Mechanical properties such as resistance to moisture-induced damage were evaluated by the tensile strength ratio (TSR) approach, rutting resistance was evaluated by a laboratory wheel tracking test using a wheel rut tester (WRT), and flexural fatigue characteristics were evaluated by four point bending using a repeated load testing (RLT) machine. The effects of nominal maximumaggregate size (NMAS), working temperature, and type of mixture on the properties ofWMAmixtures were investigated. The experimental results were statistically analyzed to identify the major influencing factors and their significance. © 2017 American Society of Civil Engineers.Item Structure-sensitive electrocatalytic reduction of co2 to methanol over carbon-supported intermetallic ptzn nano-alloys(American Chemical Society service@acs.org, 2020) Payra, S.; Shenoy, S.; Chakraborty, C.; Tarafder, K.; Roy, S.The electrochemical reduction of CO2 (CO2RR) to produce valuable synthetic fuel like CH3OH not only mitigates the accumulated greenhouse gas from the environment but is also a promising direction toward attenuating our continuous reliance on fossil fuels. However, CO2RR to yield CH3OH suffers because of large overpotential, competitive H2 evolution reaction (HER), and poor product selectivity. In this regard, intermetallic alloy catalysts open up a wide possibility of fine-tuning the electronic property and attain appropriate structures that facilitate selective CO2RR. Here, we report for the first time the CO2RR over carbon-supported PtZn nano-alloys and probed the crucial role of structures and interfaces as active sites. PtZn/C, Pt3Zn/C, and PtxZn/C (1 < x < 3) synthesized from the metal-organic framework material were characterized structurally and morphologically. The catalysts demonstrated structure dependency toward CH3OH selectivity, as the mixed-phase PtxZn/C outperformed the phase-pure PtZn/C and Pt3Zn/C. The structure-dependent reaction mechanism and the kinetics were elucidated over the synthesized catalysts with the help of detail experiments and associated density functional theory calculations. Results showed that in spite of low electrochemically active surface area, PtxZn could not only have facilitated the single electron transfer to adsorbed CO2 but also showed better binding of the intermediate CO2 •- over its surface. Moreover, the lower bond energy between the mixed-phase surface and -OCH3 compared to the phase-pure catalysts has enabled higher CH3OH selectivity over PtxZn. This work opens a wide possibility of studying the role of interfaces between phase-pure nano-alloys toward CO2RR. © 2020 American Chemical SocietyItem Sustainable reflective triple glazing design strategies: Spectral characteristics, air-conditioning cost savings, daylight factors, and payback periods(Elsevier Ltd, 2021) Gorantla, K.; Saboor, S.; Kontoleon, K.J.; Mazzeo, D.; Maduru, V.R.; Vali, S.V.Buildings with conventional glazing systems are responsible for excessive cooling and heating costs. Sustainable use of energy in building environments requires the use of high-performing opaque and windowed walls. Triple glazing units attenuate solar heat gain/loss compared to single- and double-glazing assemblies, thus reducing air-conditioning costs and greenhouse gas emissions. The optical, energy, economic and environmental performances of a glazing unit are strictly correlated with each other. An improvement of optical properties leads to higher glazing energy performance, cost savings, and greenhouse gas emission mitigations. This work aims to suggest and define an energy-efficient triple glazing unit for lowering cooling and heating costs in buildings while experimentally testing the spectral performance of reflective glasses and assessing heat gains/losses. In this regard, bronze, green, grey, sapphire blue, and gold reflective glasses were considered and settled in sixty different triple glazing combinations. Spectral characteristics of reflective glasses were measured experimentally using a spectrophotometer over the entire solar spectral range (300–2500 nm). For the aims of this investigation, a numerical model was developed to assess the net annual cost saving ($/m2) and the payback period of the examined glazing units for the eight cardinal directions (N, N-E, E, S-E, S, S–W, W and N–W). The results confirmed that the TWG35 window glass unit in the S-E orientation was the most energy-efficient glazing in terms of alleviating this critical challenge (air-conditioning cost-saving 16.72 $/m2 among all other studied window glass units), while a payback period of 2.2 years was revealed. On the other hand, the TWG33 window glass unit has led to the optimal-lowest payback period (2.1 years), with a net annual cost saving of 16.55 $/m2. The findings of this paper demonstrate the significance of triple-glazing design approaches from an economic and environmental point of view. © 2021 Elsevier LtdItem Effects of fiber addition on performance of high-performance alkali activated slag concrete mixes: An experimental evaluation(Taylor and Francis Ltd., 2022) Manjunath, R.; Narasimhan, M.C.; Kumar, S.There is an ever-increasing awareness on issues connected with emission of high amounts of greenhouse gases from various industries, including that from the concrete construction industry. Performances of alternative binder systems including geopolymers and alkali activated slag concretes are being investigated in this context. There is again a continuous drive to enhance their performances, both when green and on getting hardened and so also, simultaneous efforts are being made to take advantage of all the various fast-track, state-of-art construction technologies, leading to efficient, eco-friendly and economical infrastructure projects. The present authors have developed and evaluated a new set of such alkali activated slag concrete mixes having self-compacting property, along with higher mechanical properties (hereafter referred to as HPAASC mixes) using three industrial by-products, all obtained from iron and steel industry. While these HPAASC mixes have higher compressive strengths (in the range of 70–90 MPa), reasonable split and flexural strengths and are self-compacting, they continue to be brittle just as other high strength concrete mixes. In order to improve their cracking behaviour during failure, either under mechanical loads or on exposure to higher temperatures, addition of increasing amounts of steel fibers in HPAASC mixes is contemplated. Hence in the present study, the attempt is to study the effect of incorporation of fibers (within a small range of 0.4 ? 0.8%) in the new class of high-performance, fibre reinforced. Self-compacting alkali-activated slag concrete mixes–(referred to as HFSASC hereafter). The present study evaluates the properties such as flow ability, compressive strength and flexural toughness performances for these mixes. Results in the present study indicate that, while all the HFSASC mixes exhibit satisfactory passing and flowing abilities specified as per EFNARC standards for self-compacting mixes, they exhibit enhanced toughness characteristics too. © 2020 Informa UK Limited, trading as Taylor & Francis Group.Item 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.Item Efficient photoelectrocatalytic conversion of CO2 to formic acid using Ag-TiO2 nanoparticles formed on the surface of nanoporous structured Ti foil(Korean Society of Industrial Engineering Chemistry, 2022) Mubarak, S.; Dhamodharan, D.; Byun, H.-S.; Pattanayak, D.K.; Arya, S.B.Global warming and adverse climate change, which have been intensified by a strident increase in carbon dioxide (CO2) emissions, have necessitated the development of alternative techniques to reduce the disproportionate concentration of CO2 in the atmosphere. The photoelectrochemical reduction of CO2 is a technique of lowering the energy required to convert greenhouse gases into useful end products. Herein, we have manufactured an innovative, cost-effective silver (Ag) decorated anatase TiO2 (TO-Agx; ‘x’ stands for different concentration of Ag) nanoparticles which created on the 3D nanoporous structured surface of a thin titanium foil (Ti-foil) by the assist of chemical treatment with hydrogen peroxide (H2O2) and different concentrations (1, 5, 10, 20 mM) of silver nitrate (AgNO3) solution and followed by calcination at 500 °C. As-prepared samples were analyzed by several characterization techniques such as XRD, XPS, TEM and Raman spectroscopy. Among various samples (TO, TO-Ag1, TO-Ag5, TO-Ag20), the TO-Ag10 sample were exposed a supreme photocurrent density of 83.2 µA/cm−2 (86.1% higher than TO sample which is untreated with AgNO3 solution). Because of its high photocurrent density, the sample TO-Ag10 were selected as the electrode material for photoelectrochemical CO2 reduction reaction and a lowest reduction onset potential (−1.018 V) was observed on linear sweep voltammetry analysis in the presence of light with Ag/AgCl reference electrode. 1H NMR analysis of the product solution exposed the production of formic acid as a single product of CO2 reduction reaction after the chronoamperometric electrolysis were carried out more than 6 h. The maximum faradaic efficiency (73%) and formic acid yield (193 µmol cm−2 h−1) were found at an applied potential of −1.2 V (vs. Ag/AgCl reference electrode) for TO-Ag10 photocathode. © 2022 The Korean Society of Industrial and Engineering ChemistryItem Experimental analysis of a mini truck CRDI diesel engine fueled with n-Amyl alcohol/diesel blends with selective catalytic reduction (SCR) as a DeNOx technique under the influence of EGR(Taylor and Francis Ltd., 2024) Santhosh, S.; Gottekere Narayanappa, K.The current work aims to investigate the compatibility of n-Amyl alcohol in a mini-truck common rail direct injection (CRDI) compression ignition (CI) engine with exhaust gas recirculation (EGR) and selective catalytic reduction (SCR) as a DeNOx technique. The n-Amyl alcohol is a renewable biofuel it effectively mitigates the demand for fossil fuels and reduces greenhouse gas emission. Palladium and Rhodium coated SCR catalyst was used to reduce the nitrogen oxides (NOx) emission. For SCR of NOx ammonia was used as a reductant. From the experimental results, it was noted that with an increase in the percentage of alcohol in the blends, a slight drop in brake thermal efficiency (BTE) and higher brake specific energy consumption (BSEC) was observed. Both NOx and hydrocarbon (HC) emissions could be reduced with the use of n-Amyl alcohol and a combination of SCR and EGR techniques. The maximum reduction of NOx can be successfully achieved with the use of 40N60D (40% n-Amyl alcohol & 60% Diesel v/v) blend with SCR and 20% EGR at the slight cost of BTE. The engine can be successfully worked up to 40% of n-Amyl alcohol/diesel blends without causing any visible damage to the engine, with less NOx emissions. It is concluded that n-Amyl alcohol will be a sustainable next-generation biofuel for commercial vehicles. © 2020 Taylor & Francis Group, LLC.Item Downscaled XCO2 Estimation Using Data Fusion and AI-Based Spatio-Temporal Models(Institute of Electrical and Electronics Engineers Inc., 2024) Pais, S.M.; Bhattacharjee, S.; Anand Kumar, M.; Chen, J.One of the well-known greenhouse gases (GHGs) produced by anthropogenic human activity is carbon dioxide (CO2). Understanding the carbon cycle and how negatively it affects the ecosystem requires analysis of the rise in CO2 concentration. This work aims to map CO2 concentration for the entire surface, making it useful for regional carbon cycle analysis. Here, column-averaged CO2 dry mole fraction, called XCO2, measured by the orbiting carbon observatory-2 (OCO-2) satellite, is used. Because of spectral interference by the clouds and aerosols, there are many missing footprints in the Level-2 swath of OCO-2, making it disruptive to understand any assessment related to the carbon cycle. The objective of this work is to predict 1 km2 XCO2 using data resampling and machine learning models. This work achieves a minimum mean absolute error (MAE) and root mean square error (RMSE) of 0.3990 and 0.8090 ppm, using the monthly models. © 2004-2012 IEEE.Item Climate indices and drought characteristics in the river catchments of Western Ghats of India(Springer Science and Business Media Deutschland GmbH, 2024) Shetty, S.; Umesh, P.; Shetty, A.The study addresses the long-term trend in rainfall, minimum and maximum temperature, and the climate indices for the river catchments located in the diverse climate of the Western Ghats of India. The dry sub-humid Chaliyar catchment and humid Kajvi catchment have shown a dramatic change in the decadal rainfall, with the decade 1950–1960 being the point of change. The monsoon rainfall has decreased in the Chaliyar and Netravati catchments and increased insignificantly in the Kajvi catchment. With the increase in mean temperature, the number of rainy days is decreasing, and intense rainfall is increasing in the pre-monsoon. The increase in minimum temperature is more severe in all three catchments, irrespective of the region’s climate. The decline in rainy days is more figurative in the humid and per-humid catchments and has seen a 16–20% decrease in R×1 day, R×3 day, and R×5 day in the past six decades with an insignificant increase in the dry sub-humid catchment. The frightful increase in warm days/nights with a decrease in cool days/nights has been alarming for the extremity of temperature in future years. The significant changes in the forest area in Chaliyar and Kajvi catchment and the increase in a built-up area in Netravati may have a decisive role in the nonseasonal variability in rainfall and temperature along with increasing greenhouse gases. In the case of meteorological drought studied using the Standardized Precipitation Index (SPI), moderate droughts have occurred over the Chaliyar and Kajvi, and extreme droughts over the Netravati catchments with no reduction in the frequency or severity of short-duration extreme rainfall events. The geographical location of the catchment has a greater impact on the characteristics of the rainfall and meteorological drought, and these changes in the hydrological regimes of the catchment have a significant bearing on the water availability in the catchments in the future years. © The Author(s) under exclusive licence to Institute of Geophysics, Polish Academy of Sciences & Polish Academy of Sciences 2023.