Applied Sciences and Chemical Engineering

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

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Metal Organic Framework Decorated Hemp Hurd Derived Carbon for Energy Storage Application
(Pulchowk Campus, 2025-05) Pal, Gyanendra; Mukhiya, Tank
“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
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.
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.
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.
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.
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
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
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.
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.
Analysis of Morphological properties of Ag3PO4 embedded Polyacrylonitrile electrospun membrane for waste-water treatment
(I.O.E. Pulchowk Campus, 2022-09) Shrestha, Sugandha
Electrospinning is a straightforward, inexpensive and quick method for the fabrication of nanofibres and nanofibre-based materials. In this work, electrospun polyacrylonitrile (PAN) nanofibres embedded with silver phosphate (Ag3PO4) have been fabricated. Electrospun PAN nanofibres were surface modified with hydrazine to form amidoxime groups —C(CN2=NOH) for effective anchoring of silver ions, which is then converted to silver phosphate through chemical methods. The composite fibres that were produced in this way were evaluated using a Scanning electron microscope(SEM), Fourier transform infrared (FTIR), Ultraviolet-visible(UV-vis) and X-ray Powder Diffraction(XRD). Photocatalytic behaviour and antibacterial testing were done on the composite and analyzed. According to experimental findings, composite nanofibres made by reacting functionalized PAN nanofibres with 0.02Mconcentration solutions of silver nitrate and disodium hydrogen phosphate are found to be more effective in the photo-degradation of dyes when exposed to visible light and for antibacterial activity, PAN nanofibres fabricated by utilization of 0.05 M concentration solutions was found to be the most effective.
An Analysis on Building Energy Consumption by Using Simulation Tool: A Case Study of Existing Office Building in Kathmandu Valley
(I.O.E. Pulchowk Campus, 2022-03) Mandal, Roshani
Concerns about climate change are driving an increase in the demand for energy conservation. Buildings are large energy consumers in all countries, thus studying the impact of climate change on building energy performance is important. Building energy simulation software is a useful tool in this regard. A suitable set of typical weather files plays an important role in the success of building energy simulation. The objective of this research is to evaluate the impact of climate change on energy consumption mainly due to atmospheric temperature change in the future. This study reports the work of developing a set of weather data files for Kathmandu, taking into the effects of future climate change. An existing Typical meteorological year (TMY) weather file of period 1973-1996 composed of weather data by the SWERA project was assumed as the baseline climate in this study. The monthly average temperature for future periods was predicted by SDSM (statistical downscaling model) under different emission scenarios, was further downscaled to hourly temperature data using the downscaling method, morphing.
Preparation of Waste Betel Nut Based Activated Carbon and Test its Energy Storage Performance
(I.O.E. Pulchowk Campus, 2022-09) Ale, Ram Bahadur
In this study, waste betel nut based AC was prepared by chemical method of activation of finely crushed and shieved powder of waste betel nut with H3PO4 in the ratio 1:1 (by weight) followed by carbonization at temperature of 500 C. Characterization of the as prepared AC was performed by determination of iodine number (IN), methylene blue (MBN) and estimating its surface area followed by analysis of Scanning electron microscopy (SEM) image, X-ray diffraction (XRD) pattern, Raman spectroscopy pattern and Fourier transform infra red (FTIR) pattern. The MBN, IN and surface area of the resultant AC was determined to be 365 mg g−1,882 mg g−1 and 927 m2 g−1. These analyses suggested the formation of AC with high specific surface area and high porosity from waste betel nut, successfully. The cyclic (CV) curve galvanostatic charge discharge curves shows that as prepared working electrode fabricated by using as waste betel nut based AC, exhibits specific capacitance increases to 154 F g-1 at current density of 0.5 Ag-1. This suggests a probable use of as prepared AC as supercapacitor electrode material. Moreover, preparation of AC from waste betel nut is a simple way of bio-waste management.
Study on Phytoremediation and Biomass-Adsorption of Cationic and Anionic Dye using Azolla Pinnata
(I.O.E. Pulchowk Campus, 2022-10) Gyawali, Manoj
Waste water generated from the textile industry consists of non- biodegradable complex compounds such as dye. This waste water can be toxic to the living organism. Hence, the treatment of the waste water consisting dye is very important before it is released streams, lake, river etc. Among the several methods of dye waste water treatment such as adsorption, filtration, bio adsorption and photo degradation, Phytoremediation is suitable because it is naturally occurring process on which micro-organism or plant transforms or immobilize the complex compounds such as dye. Azolla Pinnata, phytoremediation plant can be used for extraction of the dye and complex compound from waste water.
Morphological and Mechanical Characterization of Ag Nanospecies Decorated Electrospun Membrane for Water Purification
(I.O.E. Pulchowk Campus, 2022-10) Thapa, Kshitij
Membrane development includes a wide array of technological fields, which includes design of process and product, various fields of engineering such as materials engineering, chemical engineering, and also interaction phenomena. Progress in membrane technology can help resolve most worldwide problems related to water, healthcare, energy, air, and consequently global warming. Currently, electrospun polymeric fiber membranes are dominant products because of their broad spectrum of materials and process-dependent architecture with desirable physico-chemical properties for diverse applications. The low cost and ease of fabrication of nanofibers with different functionalities make electrospinning superior to other techniques. Using this process, one can easily incorporate nanoparticles of metal and metal oxide through nanofibers to get composite nanomaterials for different applications. In this work, dual membranes, one having amphiphilic/antibacterial and photocatalytic properties and another having antibacterial and hydrophobic properties, are being fabricated using electrospinning.
Preparation and Characterization of Activated Carbon from Harro (Terminalia chebula) Seed Stone by Chemical Activation with Phosphoric Acid for Energy Storage Devices.
(I.O.E. Pulchowk Campus, 2022-10) Rajguru, Kirti Bir
In order to meet the growing energy demand, effective energy storage devices are essential. Harro is a novel and bio-based precursor for the preparation of activated carbon (AC). In energy storage technologies, activated carbon is applied as an electrode material. By utilizing phosphoric acid as the activating agent, study examined at how the carbonization temperature affected the pore structure and surface chemistry of activated carbon from Harro seed stone. The AC was prepared at various temperatures such as 4000C, 5000C, 6000C and 7000C i.e.HS4, HS5, HS6 and HS7. By using FT-IR, XRD, SEM, Surface area, Total pore volume, Iodine number, Micropore volume, Methylene blue number and Raman Spectroscopy, study examined the physiochemical characteristics of the synthesized AC. Using cyclic voltammetry, the synthesized AC's electrochemical performance was examined. Results showed that, the activated carbon at 4000C has the greater surface area, Iodine number and Micropore volume of 977.19 m2/g, 960.45 mg/g and 0.69 cm3/g respectively. And the activated carbon at 7000C has highest value of Methylene blue number and specific capacitance of 334.72mg/g and 9.26× 10-3 Fcm-1 respectively.
Development and Characterization of Bacteria based Self-healing Concrete
(I.O.E. Pulchowk Campus, 2023-04) Neupane, Gaurab Raj
It is highly typical for concrete structures to develop cracks as a result of different load and non-load causes, which shortens their useful lifespan. Hence, maintenance and repair procedures are required to stop cracks from spreading and shortening the service life of the buildings. However, access to the damaged areas may be challenging because of the high labour and material costs connected with the fixing and upkeeping of concrete structures. One potential approach is autonomous healing using bacteria-based self-healing agents in capsules. The bacteria are activated by water and oxygen availability when released from a broken capsule during this process. Aerobic digestion of bacteria produces calcite which in turn is used to fill up the microcracks in concrete.
Engineering carbon and nitrogen intermingled three dimensional porous cobalt oxide polyhedrons/nanowires for energy storage
(I.O.E. Pulchowk Campus, 2022-09) G.C., Bishal
There is great demand in the development of efficient and economic energy storage devices to address the environmental and exhausting issues of fossil fuel. Supercapacitor, a promising energy storage technology for future generation, demands enormous improvement in its electrode such high specific surface area, high porosity, conductivity and proper architecture. Among various materials, cobalt oxide (Co3O4) has high capacitance but less stability and conductivity. Recently, metal-organic frameworks (MOFs) have been used to enhance the surface area and controllable porosity. However, there is still a challenge to design and synthesize assembly of nanostructure with proper architecture. Here, MOFs-based carbon and nitrogen intermingled highly porous three dimensional (3D) cobalt oxide polyhedrons have been assembled with their nanowires on nickel foam by a combination of hydrothermal, solution, carbonization and calcinations method. Here, MOFs ensured high surface area, high porosity and also contribute carbon and nitrogen required for enhancing conductivity of cobalt
Fabrication of Metal Oxide/ Activated Carbon Nanocomposite from Jujube (Ziziphus Mauritiana) Seeds for Photodegradation of Dye
(I.O.E. Pulchowk Campus, 2022-10) Kumari, Anshu
The photocatalytic degradation of dye from water using metal oxide semiconductor is the study of great interest due to its environmental and health concerns. The aim of this study is to fabricate metal oxide/activated-carbon composite using zinc oxide and copper oxide with agro-base Indian Jujube (Ziziphus Mauritiana) activated-carbon for dye degradation from aqueous solution. Indian Jujube seed was used to synthesize agro-based activated carbon (JAC) using ZnCl2 as an activating agent at carbonization temperature 500°C for 3 hrs. Thus, prepared JAC was used to synthesize metal oxide/activated carbon nanocomposites by one-step hydrothermal process. Both, activated carbon and its composite were characterized by SEM, FTIR, XRD, and UV-Vis spectroscopy. The UV-Vis spectroscopy result showed the increment in band gap of CuO in case of CuO/JAC nanocomposite from ̴ 2.3 eV to ̴ 2.6 eV while decrease in band gap of ZnO in case of ZnO/JAC nano-composite from 3.3 eV to 3.2 eV revealing the enhanced photocatalytic activity of nanocomposites. The kinetic study followed pseudo-first order kinetics for the degradation of MB & MO dye. The rate constant for MB and MO dye degradation using ZnO/JAC were 0.163 min-1 and 0.009 min-1 respectively.
Effect of Activated Carbon, CMC and Fly Ash on Different Grade of Concrete
(I.O.E. Pulchowk Campus, 2023-04) CHAUHAN, ADARSHA
Cement is the extensively used material in the world after water. Adding new functional materials to like Activated Carbon (AC), Carboxymethylcellulose (CMC) sodium salt, fly ash (FA), PCE (Poly Carboxylic Ether) based plasticizer can improve the quality and add novel characteristics. Also, reducing the usage of cement. This study focused on the investigation of compressive strength and modulus of elasticity after introduction of CMC, AC, FA on different grade of concrete. 41 batches of concrete were prepared and tested for M 30 and M 25 grade concrete. The AC being a highly hydrophobic material, agglomeration occurs. CMC sodium salt aqueous solution is chosen surfactant to form the gel structure to disperse the AC. Standard mix design of 132 concrete cubes were carried out varying CMC, AC, FA and its effects were analyzed.

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