Lakshminath Bezbaroa Central Library Digital Repository
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- This digital archive comprised of the Institutes' intellectual output.
- It manages, preserves & makes available the academic works of faculty and research scholars.
- It is established to facilitate deposit of digital content of scholarly or heritage nature.
- Allowing academics & their departments to share & preserve contents in a managed environment.
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Recent Submissions
Transported emissions from the Indo-Gangetic Plain dominate Air pollution and Climatic impacts over North East India during Pre-monsoon season
(2024) Barman, Neeldip
Aerosols are suspended particles that can significantly impact air quality as well as weather through their different effects. The westerlies carry emissions from the Indo-Gangetic Plain towards North-East India through atmospheric transport along the southern slope of the Himalayas and contribute to the aerosol burden over North-East India. The pre-monsoon season is a period of high aerosol loading over North-East India, with the highest atmospheric heating and aerosol optical depth with an increasing trend. Moreover, studies have also reported a declining rainfall trend and an increasing rainfall intensity over this region. This study investigated the direct, semi-direct and indirect radiative effect of atmospheric aerosols and black carbon, specifically on the rainfall mechanisms responsible for the pre-monsoon rainfall over North-East India with the WRF-Chem model. Aerosol radiative effects affected rainfall according to the height of the terrain in the North-East India region. Aerosol effects, in general, tended to increase total rainfall over lower-terrain areas, whereas moisture reduced between 2-3 km, which decreased total rainfall over high-terrain areas. The study also differentiated the impacts of aerosols emitted locally within the NE India region and those transported from outside this region to ascertain whether local or transported aerosols were more impactful in influencing this region’s rainfall during this season. The role of different aerosol effects on radiative forcing and rainfall was also studied. Results show that aerosols transported primarily from the Indo-Gangetic Plain were responsible for about 94% of the PM10 mass over North-East India’s atmosphere and 64% of near-surface PM10 concentration. The indirect aerosol effect was found to be the major effect and more impactful with transported aerosols that dominated both rainfall and radiative forcing and suppressed rainfall significantly than the direct and semi-direct effect. Thus, this study found that emission control policies implemented in Indo-Gangetic Plain will reduce air pollution as well as the climatic impacts of aerosols over the North-East India region. The study also compared the performance of planetary boundary layer parametrization schemes to select a suitable scheme to accurately predict meteorological parameters during the pre-monsoon and monsoon season with the WRF model at an enhanced resolution of 3 km grid size compared to the 10 km used in WRF-Chem.
Development of inverse optimization model for identification of virus sources in the saturated-unsaturated zone
(2024) Das, Mamata
Groundwater aquifers, essential drinking water sources, are vulnerable to virus contamination. Identifying the source of viruses in groundwater can help determine the appropriate measures needed to prevent or mitigate contamination, protect public health, and maintain the quality of groundwater resources. This study focuses on developing an effective source identification model in an unconfined groundwater aquifer considering both the unsaturated and saturated zones. This model is developed using a linked simulation optimization model, where the objective function minimizes the error between the observed and simulated virus concentration. Current computational models like HYDRUS-3D and MT3DMS have shortcomings in addressing variable degrees of saturation and activation rates of viruses. To overcome these limitations, a three-dimensional virus transport model is developed, encompassing the unsaturated and saturated zones and accommodating variations in transport parameters due to saturation degree. The model is developed in the MATLAB environment. However, some of these parameters are not available on field and laboratory scale and thus need a parameter estimation model. As such a parameter estimation model is developed for coupled unsaturated and saturated zone to estimate the flow and transport parameters using Metaheuristic optimization algorithm. Once the computational virus transport model is developed, it is linked with an optimization model to identify the virus sources in the aquifer. The Shuffled Frog Leaping Algorithm (SFLA) is used as an optimization algorithm to identify the virus source location and source strength. The SFLA source identification model accurately determined the virus source locations and the source fluxes. However, the computational time required for the process was quite high. Thus, to overcome this limitation, an improved source identification model algorithm is developed by using Recurrent Neural Network (RNN) in conjunction with the computational simulation model and shuffled Frog Leaping Algorithm. This model is efficient both in computation time and predicting performance.
Life Cycle Energy Analysis of Buildings: A Systems Approach
(2024) Dahiya, Devender Singh
Buildings consumes large amount of energy and resources right from the inception to construction, operation, discard and disposal. Most of the energy consumed by the buildings is produced from fossils fuels which result in carbon emissions that lead to climate change. The current research is mainly in pursuit of the research question. What oppurtunities exists for improvement in the energy performance of buildings during various stages of their life cycle.
Reclaiming the Virangana Myth: A Study of Selected Contemporary Historical Fiction
(2024) Deka, Snigdha
Although there has been extensive scholarship and literature on the figure of the warrior woman and the gendered metaphors to disseminate hypermasculine nationalist narratives, this figure has been dominantly used as a masculine tool, as and when required, to sustain the narratives of nation and nationalism. This warrior woman is dominantly perceived and depicted as the Virangana in cultural and historical narratives in India. These representations of the popular Virangana trope also suggest how the figure, apart from being a portrayal of the once assertive pre-Aryan formation of the Mother goddess, is also stereotypically graceful, beautiful and sometimes sensual. She appears as the mother-in-pain as well as the wrathful warrior on the battlefield. The hyperbolic myth that the Virangana is made to be has found increased reproduction in popular literature, culture and media. Such reproductions claim to be essentially feminist revisions of both fictionalised history and historical fiction, thus catering to the contemporary market and “the need of the hour” narrative spin and debates.
Fabrication and Testing of PVDF Based Peng Devices for IoT Applications
(2024) Kulkarni, Nikhil Dilip
Increasing environmental pollution and battery durability have redirected energy research toward eco-friendly renewable technologies. There is a pressing need to create energy conversion and power supply devices that are both high-performing and sustainable due to the rapid development of wearable electronics and the Internet of Things (IoT). The rapid development of polymer based flexible piezoelectric sensors have attracted considerable attention due to their promising applications in nanogenerators. PVDF thin films have a wide prospect in energy harvesting applications due to flexible design and presence of electroactive phase. Despite massive work in this domain, commercial applications are very rare since PVDF based thin films have low piezo response. Composite film samples are fabricated using DMF as a solvent through low cost solvent casting approach. This research work focuses on the fabrication and testing of flexible PENG devices made up of PVDF-based composites with enhanced mechanical, dielectric, and piezoelectric response for energy scavenging purposes. PVDF-TiO2 composite films are fabricated to assess their piezoelectric performance for energy scavenging. Effect of varying rGO content on energy scavenging capacity of PVDF-TiO2 composite films is then studied. Further, the MCDM-based TODIM technique is used to select the best piezoelectric material from the samples available. Role of reinforcement of rGO in PVDF-BTO composites for enhanced mechanical and piezoelectric performance is then studied. Further, naturally available bio-compatible filler materials are explored to develop sustainable piezoelectric energy harvesters. PVDF composites based on treated BMP are tested for their suitability as impact sensor under a variety of impact loading conditions. After that, PVDF-FS based bio based energy scavenging device interacting with human body parts to monitor real-time physiological signals is developed. The surface morphology, beta phase fraction, thermal stability, mechanical behaviour, and dielectric response of all the nanocomposite structures are examined. Conductive electrodes are deposited on the top and bottom surfaces of fabricated composite films to create a PENG device. The device is then put through a series of bio-mechanical operations, including tapping, thumb pressing, film twisting, and bending, to measure piezo response.These kind of flexible piezo devices prove to be ideal for mechanical energy harvesters used in sensing applications due to their excellent overall properties and good cost-performance balance.