rashmi roy

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Analysis of Heavy Metal Pollution in the Water of the Halda River: A Distinctive Breeding Habitat for Carp Fish in Bangladesh

Background: The present study aimed to assess the heavy metal concentrations in water from differ... more Background: The present study aimed to assess the heavy metal concentrations in water from different sampling sites of the Halda River, the only natural breeding ground of Indian major carps. Objectives: We have analysed the contamination level and seasonal variations of heavy metals (viz. Fe, Cu, Zn, Cr, Cd and Pb). The favourability of the breeding environment was assessed by different contamination indices. Methods: Samples were collected from six sampling sites for four different seasons, and the metal concentrations were determined for water samples using Flame atomic absorption spectrophotometer. The obtained order of mean concentrations of heavy metals for four seasons was winter > spring > monsoon > premonsoon, and the assessed mean concentrations (mg/L) of heavy metals follow the trend: Fe (9.129) > Pb (0.033) > Zn (0.024) > Cr (0.017) > Cu (0.012) > Cd (0.002). The concentration of Fe was found above the permissible limit set by the World Health Organization (WHO) (Guidelines for Water Quality) and ECR (1997), and the concentrations for Pb were found above the USEPA (2006) limit in all four seasons. Contamination indices (heavy metal pollution Index [HPI] and metal index [MI]) indicate that during winter and monsoon, the river water metal condition is critical (HPI > 100) and the sites are moderately as well as slightly (1< MI <2) affected by the studied heavy metals. Contamination indices, such as contamination factors (C f ), degree of contamination (C deg ) and the pollution load index (PLI), demonstrate the fact that Fe and Pb remarkably contaminated the studied sampling sites. The Pearson correlation matrix and the principal component analysis (PCA) revealed that the studied metals are connected by their sources, which can be geological or anthropogenic. Conclusion: Urgent initiatives need to be taken, and effective strategies must be implemented to control the different sources responsible for the entry of heavy metals into the Halda River water. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

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Evaluating Solar Energy as a Viable Solution to Bangladesh's Energy and Environmental Challenges: Opportunities, Constraints, and the Path Forward

7th International Conference on Mechanical Engineering and Renewable Energy 2023 (ICMERE2023), 2023

Regarding Bangladesh's ongoing environmental and energy crisis, the desire for ecologically sound... more Regarding Bangladesh's ongoing environmental and energy crisis, the desire for ecologically sound and carbon-free energy sources has assumed crucial significance. It is essential to look into feasible alternatives to traditional fossil fuels as the nation struggles with issues including growing urbanization, population growth, and rising emissions of greenhouse gases. Solar energy is eco-friendly technology, a superb energy supply, and also the most significant green and renewable energy source. To address Bangladesh's energy and environmental problems, this study thoroughly reviews the opportunities and constraints of solar energy. The assessment starts with a survey of the nation's existing energy situation, emphasizing the nation's excessive reliance on fossil fuels and its effects on greenhouse gas emissions and climate change. Then explores Bangladesh's enormous solar energy possibility, highlighted by the country's geographic location and year-round sunshine. It looks at how the use of solar energy has increased recently in the nation, covering the rise of solar farms and solar photovoltaic systems. The study analyses the positive aspects of solar energy, including its potential to lower carbon emissions, create jobs, and provide access to electricity in rural locations.

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Energy-Neutral Cricket Stadium: The Zahur Ahmed Chowdhury Stadium, Analytical Design, and Computational Modeling

6 th International Conference on Electrical Information and Communication Technology (EICT), 07~09 December 2023, , 2023

Traditional ways of generating electrical energy are expensive, harmful to the environment, need ... more Traditional ways of generating electrical energy are expensive, harmful to the environment, need extensive maintenance, and will eventually be phased out. Therefore, it is necessary to explore the immense potential of environmentally friendly renewable energy sources. In this research, a gridconnected PV system that is efficient, durable, and good for the environment is proposed as a solution to this problem at the Zahur Ahmed Chowdhury Stadium (ZACS). Chittagong is one of the cities in Bangladesh with significant untapped solar energy potential. The global horizontal sun irradiance at our selected location is 1624.9 kWh/m 2 , with an average of 4.45 kWh/m 2 per day, and the average temperature is around 26.6 ℃. The system's performance ratio (PR), and also additional power losses, PV module losses, inverter, and temperature losses, are all taken into account and estimated in this study using PVSyst. Simulation yields an 85.6% PR, generating 824.5 MWh/year, with a 16% Capacity Utilization Factor (CUF). The system's implementation will curtail 11475 tons of CO2 emissions, yielding a positive environmental impact. The financial analysis evaluates various interest rates, affirming system feasibility. This innovation will greatly influence the environment and electrical industry worldwide, shaping the design, analysis, operation, and maintenance of future gridconnected systems.

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Financial Feasibility and Environmental Sustainability of Rooftop Solar PV in Chattogram: A Case Study on Residential, Commercial, and Industrial Buildings

2024 International Conference on Advances in Computing, Communication, Electrical, and Smart Systems (iCACCESS), 2024

Electricity is one of the most essential aspects of economic development. This research aims to a... more Electricity is one of the most essential aspects of economic development. This research aims to analyze the financial feasibility and environmental sustainability of rooftop-mounted solar PV for Chattogram City. Chattogram is a suitable candidate for solar PV with annual horizontal solar irradiation of 4.7 kWh/m 2 /day to 4.9 kWh/m 2 /day, which can be utilized to diminish the energy crisis and provide sustainability to energy production. We calculated the total and effective rooftop areas for residential, commercial, and industrial buildings using QGIS and AutoCAD to determine feasibility. The potential for solar PV energy generation on these rooftops was evaluated using RETScreen software. Economic parameters, including net present value, payback period, internal rate of return, GHG reduction cost, and benefit-cost ratio, were considered as performance indicators. The benefit-cost ratio and debt service coverage ratio for all three cases exceeded 1, indicating economic viability. Consequently, the proposed projects demonstrate overall feasibility.

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Synthesis of isofagomine and some new azasugars as glycosidase inhibitors from d-mannitol derived nitroolefins

Tetrahedron: Asymmetry, 2013

ABSTRACT The synthesis of isofagomine, epi-isofagomine and isofagomine analogues along with some ... more ABSTRACT The synthesis of isofagomine, epi-isofagomine and isofagomine analogues along with some new azasugars from two different vinyl nitro compounds, that were derived from d-mannitol, has been carried out. Two different synthetic strategies were followed for each of the vinyl-nitro precursors. Many of the azasugars synthesized showed inhibition in the micromolar range when tested against various glycosidase enzymes, opening up the possibility of modifying structural features for better and selective inhibition.

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