Browsing by Author "Mishra, A."

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    Effect of orientation on stability of caverns - A numerical modelling study
    (2018) Naik, S.R.; Sastry, V.R.; Mishra, A.
    3D numerical modelling studies were carried out to study the behaviour of large twin caverns belonging to a hydroelectric project in Himalayan region. Various stages of extraction of the caverns were characterised by instrumentation studies. The cavern is oriented along the major principal stress direction. Numerical model results were in close agreement with the measured values in the field. Taking this model as the base, parametric studies were carried by varying the angle between cavern axis and direction of major principal stress. Alignment of the caverns were changed at an interval of 15o. Analysis was done for 12 orientations upto an angle of 165o. Maximum stress concentration factors for all orientations were obtained on the upstream side of powerhouse cavern, in the pillar between powerhouse cavern and transformer hall cavern and on the downstream side of transformer hall cavern. Similarly, the displacements in the walls of twin caverns were compared for all orientation of the caverns. � 2018 ISRM & SRMEG (Singapore).
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    Effect of orientation on stability of caverns - A numerical modelling study
    (International Society for Rock Mechanics isrm@inec.pt, 2018) Naik, S.R.; Sastry, V.R.; Mishra, A.
    3D numerical modelling studies were carried out to study the behaviour of large twin caverns belonging to a hydroelectric project in Himalayan region. Various stages of extraction of the caverns were characterised by instrumentation studies. The cavern is oriented along the major principal stress direction. Numerical model results were in close agreement with the measured values in the field. Taking this model as the base, parametric studies were carried by varying the angle between cavern axis and direction of major principal stress. Alignment of the caverns were changed at an interval of 15o. Analysis was done for 12 orientations upto an angle of 165o. Maximum stress concentration factors for all orientations were obtained on the upstream side of powerhouse cavern, in the pillar between powerhouse cavern and transformer hall cavern and on the downstream side of transformer hall cavern. Similarly, the displacements in the walls of twin caverns were compared for all orientation of the caverns. © 2018 ISRM & SRMEG (Singapore).
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    Efficient One-Pot Green Synthesis of Chitosan-Copper Bionanoparticles Via Sustainable Hydrothermal Carbonization Route for Photocatalysis and Fenton Studies
    (Springer, 2025) Sangeetha, A.; Hariganesh, S.; Kumar, P.; Mishra, A.
    A bionanoparticle was fabricated using a facile one-pot green synthesis assisted through Hydrothermal Carbonization and evaluated for its potential as a catalyst in Advanced Oxidation Processes (AOPs) for wastewater treatment. Bio-wastes like onion peel, corn husk and groundnut shell has been employed for green synthesis of Copper-Chitosan bionanoparticles which were characterised for their optical, physical and structural properties with the available technologies to study their composition. The onion peel extract undergone Carbonization along with Chitosan during the Hydrothermal Carbonization process, has augmented the bionanoparticle to function as a visible light active photocatalyst. The synthesized materials were utilized for the degradation of dye and drug using the AOP like Photocatalysis, Fenton-like and Photo-Fenton process. The onion peel extracts aided bionanoparticles excelled in degrading Methylene Blue dye under 15 W LED, achieving 95.9% efficiency in 120 min. Additionally, it functioned as a Fenton-like catalyst, degrading Methylene Blue dye in 60 min with 96.2% efficiency, and as a Photo-Fenton catalyst, achieving 98.1% efficiency in 25 min. Since the catalyst had higher efficiency in short time for Photo-Fenton degradation, it has been optimized by adjusting parameters such as concentration of catalyst and dye, as well for varied pH levels. The catalyst achieved 90.7% efficiency during its fifth stability cycle study. For Rifampicin drug degradation, the observed efficiency was 97.1% in 70 min. This work provides a green way of synthesizing bionanoparticles and its utilization towards the waste water treatment towards degrading the emerging pollutants. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2025.
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    Slope stabilization of coal mine overburden dumps: life cycle environmental sustainability assessment of alternatives
    (Springer Science and Business Media Deutschland GmbH, 2024) Kumar, A.; Nainegali, L.; Das, S.K.; Reddy, K.R.; Mishra, A.
    The stability of coalmine overburden dumps is a crucial aspect and often requires a slope stabilization method in place to prevent slope failures. Mechanical methods like benching, gabion wall construction, geogrid reinforcement, and biological methods like the use of vegetation can suffice the need for slope stabilization. In this study, a life cycle assessment of the above-mentioned methods was performed to obtain the environmental impacts through various midpoint impact categories considering a “cradle-to-site” assessment. The system boundary for each method was created using the involved activities and associated equipment and energy needs. The Ecoinvent 3.0 database and TRACI assessment method were used to perform the life cycle impact assessment using SimaPro software. The results show that the use of vegetation caused the least impact. The highest impact under the majority midpoint categories was caused by geogrid reinforcement followed by benching, which was mostly attributed to the geogrid production and OB handling activities, respectively. The carcinogenic, followed by ecotoxicity and fossil fuel depletions, were the most impacted categories for the mechanical methods, which may be due to the release of chemical pollutants during material production or handling. Adherence to the overburden dump management guidelines and the use of renewable sources of energy are the two major aspects that can drastically curb the emission load on the environment, thus inching towards the goal of sustainability while adopting slope stabilization measures for overburden dumps. Besides imparting stability, plants provide a diverse solution to the other ills associated with the overburden storage and management. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2024.