Applied Sciences and Chemical Engineering

Permanent URI for this collectionhttps://hdl.handle.net/20.500.14540/111

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    Preparation of Activated Carbon from Jacaranda Seed Pods as Anode Material in Supercapacitors
    (Pulchowk Campus, 2025-05) Karki,Ashman; Mukhiya,Tanka
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    Black Carbon from Wildfires and Its Potential Impact on Surface Energy Balance of Khumbu Glacier, Nepal
    (Pulchowk Campus, 2025-05) Paudel,Aashutosh; Pradhananga,Dhiraj
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    Evaluating the Impact of Climate Change on Hydrological Extremes Using Deep Learning Method
    (Pulchowk Campus, 2025-05) Karki,Pramesh; Pandey,Vishnu Prasad
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    Climate Change Impact on Streamflow in the Chilime River Basin under CMIP6
    (Pulchowk Campus, 2025-05) Bhattarai,Kabita; Ghimire, Bhola Nath Sharma
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    Metal Organic Framework Decorated Hemp Hurd Derived Carbon for Energy Storage Application
    (Pulchowk Campus, 2025-05) Pal, Gyanendra; Mukhiya, Tank
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    “AMELIORATING THE MICRO-CLIMATE OF URBAN AREAS: -A CASE STUDY OF RESIDENTIAL COURTYARD BLOCK OF PATAN”
    (I.O.E. Pulchowk Campus, 2023-11) Aryal, Grishma
    The world is experiencing a crisis with climate change, and Nepal is among the most vulnerable nations. Urban areas, including those with heritage value, are experiencing an increase in air temperature due to the combined effects of climate change and the Urban Heat Island (UHI) effect. In order to lower UHI and raise outdoor thermal comfort, urban morphology is essential. Therefore, designers, planners or climatologists in order to make better microclimate and to improve thermal comfort consideration is necessary at planning phase. This paper presents a study of a major open area in a densely built and populated area in the centre of Patan to improve thermal comfort conditions in open spaces. This study focuses on the temporal-spatial analysis of how the geometry and vegetation of courtyards affect the outdoor thermal conditions in a warm, humid climate. This study will help to report the thermal environmental conditions of a courtyard open space in terms of vernacular dwelling space for present and future scenarios of climate change. This research will help to increase the comfort level of the people residing by improving indoor and outdoor thermal comfort in the courtyard with the use of appropriate construction techniques. It will also help in enhancing courtyards’ thermal conditions and contributing to an improvement of the surrounding urban
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    Thresholds and Characteristics for Heatwaves and Coldwaves in Nepal Between 1981-2020
    (I.O.E. Pulchowk Campus, 2023-11) Gupta, Adarsh
    With continuous climate change and global warming, temperature related hazards like: heatwave and coldwave must be monitored and studied, specially keeping in mind the geographical diverseness of Nepal where temperature related hazards can easily change into disasters. This study covers all the Nepal and with 40 years of statistical and climatological study of heatwaves and coldwaves unlike any other study of its kind. Also, this study attempts to provide nationalized standard criteria for monitoring heatwaves and coldwaves on district levels that has been severely lacking. With aim to determine percentile thresholds for heatwaves and coldwaves respectively and to characterize the past behaviors of both of these waves, this study analyzed the climatology and differences of heatwaves and coldwaves by using percentile method recommended by WMO based on last 40 years (1981-2020) of climatic data from 96 stations widely spread across the country. This study uses percentile method for computation of daily thresholds for heatwaves and coldwaves. Giving emphasis on 95th and 5th percentile value thresholds for heatwaves and coldwaves, these waves were identified. Also, this study extends to examine magnitude, frequency, spatial distribution and statistical comparison of these events.
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    Analyzing the Hydrological Regime of Sunkoshi River Basin, Nepal, using a Glacio-hydrological Degree-day Model (GDM)
    (I.O.E. Pulchowk Campus, 2023-12) BUDHATHOKI, SAILESH
    The Glacio-hydrological Degree-day Model (GDM), a distributed and gridded model in glacio-hydrology, uses a temperature index concept to calculate daily river discharge from snow and ice melt, rainfall and base flow. GDM calibration relies on factors like positive degree-days, snow and rain runoff coefficients and recession coefficient. The Sunkoshi River basin is a transboundary river between Nepal and Tibet. The study from 2000 to 2020 A.D includes calibration (2000-2009) and validation (2010-2020) phases in the model simulation. Its robust performance, reflected by Nash-Sutcliffe Efficiency (NSE) values between 0.79 to 0.77, volume difference below 10% and a strong R-squared (R2) value of 0.83 to 0.77, underscores its reliability. During calibration and validation, snowmelt contributes 9.68% to 11.38%, while clean ice and ice melt beneath debris account for 2.5% to 3% to the total discharge. Rainfall maintains substantial proportions at 48.26% to 50.15%, and baseflow ranges from 37.33% to 37.66% to the total discharge. In May to June's low-flow period, the study shows snow and ice melt greatly affect river discharge. Future analysis predicts a rise in ice melt's influence, especially during low-flow phases, impacting stream flow significantly. However, increasing temperatures reduce snowfall and glacier cover, to the point of diminishing ice and snow melt contributions, ultimately impacting future low-flow stream conditions.
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    Application of Glacio-hydrological degree-day Model to simulate hydrological regime of Tamakoshi River Basin, Nepal
    (I.O.E. Pulchowk Campus, 2023-12) CHAULAGAIN, NABIN
    The glaciers and snow-covered areas has been highly influential in the hydrology of the glacierized basin. Long-term water management will become more difficult as a result of climate change, which is anticipated to alter water availability. Here we have set up Glacio-hydrological Degree day Model Version 2 (GDM V.2) as a hydrological model to simulate the discharge in Tamakoshi River basin (TRB) and quantified various runoff components. The model is first calibrated and validated for the period of 2004-2009 and 2011-2020, respectively where Nash-Sutcliffe Efficiency (NSE) is 0.77 and 0.80 for calibration and validation periods. The monsoonal rain was anticipated to influence stream flow changes the most (46.86%), followed by base flow (37.57%), snowmelt (12.17%), and ice melt (3.18%) form the year 2004-2009 and rain (46.33%), followed by base flow (38.79%), icemelt (3.27%), and snowmelt (10.77%) from 2011-2020 according to the model. Forecasts indicate a rise in discharge under SSP58.5, notably reaching 3.68 m3/s according to EC-Earth3, in stark contrast to the declines projected under SSP24.5, such as the decrease to 0.09 m3/s under Nor ESM2-MM, between SSP24.5 and SSP58.5, constituent contributions exhibit significant variations, shedding light on potential shifts in resource availability.
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    COMPARATIVE ANALYSIS OF LONG SHORT-TERM MEMORY (LSTM) AND MULTI-LAYER PERCEPTRON (MLP) MODELS FOR RIVER RUNOFF PREDICTION IN THE HINDU KUSH HIMALAYAN REGION
    (I.O.E. Pulchowk Campus, 2023-12) Shrestha, Hansal
    Hydrological forecasting in the Hindu Kush Himalayas (HKH) presents special challenges because of the complex interplay between climatic and environmental factors. The quantitative predictive capabilities of two well-established models, Long Short-Term Memory (LSTM) and Multi-Layer Perceptron (MLP), chosen for their proven performance in previous studies, are meticulously compared in this thesis. The analysis uses comprehensive data spanning 2001 to 2013, including discharge records from the Department of Hydrology and Meteorology (DHM), precipitation data from APHRODITE, temperature data from APHRODITE, and snow cover area information from Google Earth Engine with MOD09A1 V6.1. The study employs rigorous evaluation metrics, revealing nuanced insights into the hydrological processes. Contrary to expectations, the MLP model exhibited slight superiority, showcasing a nuanced understanding of the region's complexities. The quantitative assessment, including RMSE (LSTM: 0.2396, MLP: 0.1733), MAE (LSTM: 0.1698, MLP: 0.0841), R2 Score (LSTM: 0.9976, MLP: 0.9987), and NSE (LSTM: 0.9976, MLP: 0.9987), emphasizes the indispensable role of robust predictive models, showcasing the necessity of reliable models for enhancing accurate river runoff predictions crucial for effective water resource management and flood preparedness in challenging terrains like the HKH.
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    Remote Sensing and GIS Based Assessment of Avalanching Glaciers in the Himalayas Due to Climate Change
    (I.O.E. Pulchowk Campus, 2023-12) Yadav, Pranav
    Hanging glaciers are a significant risk factor for avalanches, which can cause major disasters. Icefalls and avalanches from hanging glaciers pose a continuous threat to the regions beneath them. Therefore, it is imperative to invest in monitoring, analyzing, and modeling these phenomena. This will help to produce reliable forecasts, which can be used to take timely and efficient actions, such as evacuating areas. The analysis and modeling of avalanches can also help to improve our understanding of the underlying processes and influential factors. This can lead to the development of more effective early warning system. One approach to identifying potential avalanche zones is to use the Analytical Hierarchy Process (AHP) within a Geographic Information System (GIS) platform. This method has been proven effective for mapping avalanche-prone areas in rugged mountain landscapes. Another approach is to use a numerical simulation model such as the Rapid Mass Movement Simulation (RAMMS) model. This model can be used to simulate the flow dynamics of sites with potential avalanche activity. Both approaches have demonstrated their efficacy in predicting avalanche hazards in snowy and glacial environments. The goal of this study is to comprehensively address the societal impacts of avalanches, viewing them both as hazards and as disturbances within the environment. Keywords: Avalanche, Analytical Hierarchical Process (AHP), Hazard, Hanging glacier, Mass
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    Analysis of thermal comfort in free-running and mixed-mode office buildings during summer season: A case study of Kathmandu Valley
    (I.O.E. Pulchowk Campus, 2023-12) Rai, Anju
    Nepal is witnessing a more rapid temperature increase compared to the global average, heightening concerns about potential thermal discomfort and its impact on the workplace environment. Addressing this, there is a critical need to prioritize improvements in the indoor thermal conditions of office buildings to mitigate potential adverse effects on occupants. The indoor environmental quality, encompassing thermal comfort and indoor air quality, holds substantial sway over occupants' well-being and productivity in office settings. Therefore, fostering a comfortable and productive working environment is paramount for effective work outcomes. The scientific community, particularly in building analysis, has shown increased interest in issues related to thermal comfort and indoor air quality, evident in recent revisions to the Directive 2018/844/EU on the energy performance of buildings. This study aims to report on the thermal environment conditions in free-running and mixedmode office buildings and assess the thermal perception of office employees during the summer season. Through physical parameter monitoring and survey questionnaires conducted in Kathmandu Valley during June-July 2023, the study determined the comfort temperature using Griffiths' method. The results indicate comfort temperatures of 27.21 °C
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    Synthesis of Silica Aerogel with and without Glass Wool
    (I.O.E. Pulchowk Campus, 2023-04) Sah, Sunny Kumar
    Aerogel is one of the most researched and versatile products in the current era. Since its invention, silica is mostly used for making aerogel by using three major processes called supercritical drying, ambient pressure, & freeze-drying process. So, this project illustrated the making of silica aerogel from laboratory reagent-type sodium silicate (commercial grade) available in the Nepali market and glass wool was utilized for reinforcing the structure. In this project, the work is focused on the simple method called the ambient drying process to synthesize the silica aerogel with and without glass wool. The silica gel samples were prepared from sodium silicate through the sol-gel process with and without glass wool. The gel samples were passed through the solvent exchange process using ethanol and then modified using 4:30:1 & 20:30:10 ratios of TMCS (Trimethyl Monochlorosilane): n-hexane; ethanol which gave two types of samples called Type-1 & Type-2 respectively. The modified samples were then dried at ambient temperature to get the final product. From the characterization, it was revealed that all Type-2 samples and only S1, S2, S3 & A1 of Type-1 showed the presence of Si-C bond to confirm the hydrophobic nature. Further, the contact angle of 146.7o & adsorption of organic oil was higher for the Type-2 sample. But the mechanical test was not feasible for the sample with glass wools due to cracks and improper binding between silica & glass wool.
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    Preparation and Characterization of Activated Carbon from Amla (Phyllanthus emblica) Seed Stone by Chemical Activation with Phosphoric Acid for Energy Storage Devices
    (I.O.E. Pulchowk Campus, 2022-09) Bhandari, Sujan
    In order to mitigate climate change and ensure stable energy supply, energy storage is essential. Activated carbon (AC) has a large surface area which makes it ideal electrode for energy storage devices such as supercapacitors. In this work we have used Amla seeds as precursors to produce AC because of their novelty and managing agricultural waste. The AC was produced at temperatures of 4000C, 5000C, and 6000C using Phosphoric acid as activating agent. Their characterization showed AC prepared at 500 0C and 6000C had the highest surface area and amorphous contents. They also showed the comparatively high specific capacity of 0.113 Fcm−2 and 0.0729 Fcm−2 respectively for samples at temperatures 500oC and 600oC which means the AC prepared at these temperatures are suitable for energy storage devices.