SLIIT International Conference On Engineering and Technology Vol. 03 [SICET] 2024

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Analysis of Efficiency and TheAdsorptionNature ofMalachiteGreenDye fromanAqueous Solution on activatedCarbonGenerated fromStrychnos potatorum(Ingini) seeds
(SLIIT, Faculty of Engineering, 2024-10) Buthpitiya, B.L.S.K.; Yohan, L. N.; Arachchige, M
Malachite green (MG) is a basic dye with an amino group which is water soluble. This is a higher brilliance dye even in low concentrations. Therefore, MG is used mainly in dyeing for wool, leather, cotton, paper, wood, jute and as an anti-bacterial, anti-fungal, and anti-parasitical agent in aquaculture. The releasing of wastewater with MG from various industries is a huge problem because of the existence of MG in the wastewater causes toxicity for aquatic lives and it enters into the trophic levels of the food chains and causes teratogenic, mutagenic, carcinogenic and tumor-enhancing effects on human beings. Therefore, the major concern of this study is the removal of MG dye from an aqueous solution on activated carbon generated from Strychnos potatorum (Ingini) seeds (ACSP). The ACSP was characterized by Scanning electron microscope (SEM). The batch adsorption studies were conducted to determine the effect of adsorbent dosage, initial MG concentration, contact time and temperature on the removal of MG. The efficiency of the dye adsorption was determined by Pseudo-first order and Pseudo-second order kinetic models. The adsorption nature was determined by the thermodynamic study. According to the results of this study, the maximum removal percentage of MG dye (99.67%) was obtained for 0.20 g of adsorbent per 25.00 mL of MG volume, pH 4, 30 0C, 60 mg L-1 of initial MG concentration and 2 h contact time and Pseudo-second order kinetic model was well fitted to the data. The negative value for the Gibbs free energy change showed the spontaneity and feasibility of this adsorption process.
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Analysis of Service Quality Expectation of Passengers: Case Study of Colombo Fort Railway Station
(SLIIT, Faculty of Engineering, 2024-10) Jayathilake, M.N; Fernando, S.S.S.; Madushanka, P.G.D.; Sharic, A.H.S
This study investigates passenger perceptions of service quality at Colombo Fort Railway Station using the SERVQUAL model, focusing on five key dimensions: tangibility, reliability, responsiveness, assurance, and empathy. By examining demographic characteristics such as gender, age, income, frequency of use, trip purpose, and time of travel, this research aims to identify significant differences in service quality expectations among diverse passenger groups. Data were collected from 300 passengers through a structured survey and analyzed using t-tests and ANOVA. The findings highlight critical areas for improvement, including enhanced schedule adherence, improved communication, and better maintenance of station facilities. Notably, the study reveals that daily and weekly commuters report lower satisfaction levels with train punctuality compared to occasional users, while older passengers express higher satisfaction with emergency response and lost item retrieval services. These insights provide valuable recommendations for Sri Lanka Railways to enhance service quality, thereby increasing passenger satisfaction and loyalty. The study underscores the importance of tailored service improvements to meet the specific needs of different passenger demographics, contributing to a more efficient and reliable railway system in Sri Lanka.
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Associations Between Socioeconomic and Trip Characteristics of Bus Passengers to Plan for Transfer-Based Bus Transport Operations (TBBTN)
(SLIIT, Faculty of Engineering, 2024-10) Silva, K.N.R.; Sharic, A.H.S.; Bandara, J.M.S.J.
Sri Lanka's bus transportation system relies heavily on direct routes connecting main town or city centers, leading to operational challenges such as route overlap, increased fleet requirements, and financial losses. To address these issues, this study advocates for a transfer-based bus transportation (TBBTN) approach. The proposed strategy involves shortening route lengths, boosting service frequency, and minimizing overlap to potentially enhance revenue per kilometer for operators. However, this approach introduces passenger inconvenience as travelers are required to switch buses. Analyzing the associations between passenger socioeconomic characteristics and trip characteristics is crucial for effective TBBTN planning. Data was collected through interviews with randomly selected passengers, and the study revealed that as passengers' ages increased, their service expectations rose, with younger passengers expressing concerns about trip costs. The TBBTN aims to streamline transfers and reduce travel expenses, catering to diverse income groups. The positive correlation between income levels and service expectations supports the potential for TBBTN to offer improved amenities. With buses being widely used for work and educational trips and considering reduced car ownership among young and middle-aged passengers, TBBTN emerges as an affordable alternative. The study also emphasizes the importance of addressing gender-specific service expectations, particularly safety concerns among females, by establishing well-lit and secure transfer points. Ultimately, the proposal recommends prioritizing passenger expectations, affordability, and addressing diverse demographic needs to enhance the overall transportation experience for all.
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Auto-encoder Based Data Clustering for Typical and Atypical Repetitive Child Hand Movement Pattern Identification
(SLIIT, Faculty of Engineering, 2024-10) Wedasingha, N; Samarasinhe, P; Seneviratne, L; Papandrea, M; Puiatti, A
This study is dedicated to the important task of identifying unique repetitive hand movement patterns in children, with the aim of facilitating early anomaly detection. The current body of literature lacks a comprehensive model capable of effectively discerning distinctive patterns in child repetitive hand movements. To address this gap, our innovative approach employs autoencoders to efficiently compress intricate data and extract latent features from a dataset with inherent limitations. By utilizing clustering techniques, we analyze these features to reveal distinct behaviors associated with child hand movements. Despite the challenges posed by binary annotated datasets, our model demonstrates outstanding performance in categorizing movements into four distinct types, thereby providing valuable insights into the intricate landscape of child hand movement patterns. Statistical assessments further underscore the superiority of our autoencoder, achieving a mean Bayesian value of 0.112, outperforming state-of-the-art algorithms in this domain. Subsequent in-depth analysis exposes notable inter-cluster patterns, elucidating transitions from typical to atypical behavior in child hand movements. This research constitutes a significant advancement in the field of child hand movement pattern analysis, offering a powerful and sophisticated tool for healthcare professionals and researchers alike. The automation capabilities embedded in our model empower these professionals to address childhood behavioral disorders more effectively and efficiently. In essence, our research not only contributes to the enhancement of early anomaly detection systems but also serves as a valuable resource for professionals engaged in child healthcare and behavioral research, facilitating a deeper understanding of these nuanced patterns.
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Battery-Less Sensor Node Design with Solar Panels and LoRa for Wireless Sensor Networks
(SLIIT, Faculty of Engineering, 2024-10) Premachandra, N.G.P.R; Edirisinghe, S
A wireless sensor network (WSN) is a network of sensors that detect physical changes and convert them into analog or digital signals. These sensors communicate with each other to monitor and collect data from a specific area. Applications of WSNs range from environmental monitoring to agriculture, industrial automation, etc. The current WSN nodes are powered by rechargeable batteries and designed for short distances. The problems faced with current WSNs are short-distance communication, battery replacement in large, deployed networks, and rechargeable batteries that take longer time periods to recharge. The term “battery-less” refers to devices that operate without traditional batteries or external power sources. In this design, solar energy is used as a sustainable energy source, and supercapacitors are used to store the solar energy. Supercapacitors have a greater number of charging-discharging cycles than batteries, which can operate in a wide temperature range. They are also more environmentally friendly than typical batteries. LoRa is the technology used for long-range communication, which operates in Industrial, Scientific, and Medical (ISM) radio bands, which is the most cost-effective technology that provides wide coverage with low power consumption. For power management, lowpower approach and sleep mode are used to make the sensor node work efficiently with the stored power in the supercapacitors. The whole system design was optimized, taking scalability, performance, and cost-effectiveness into account.
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ChemicalOxygen Demand Reduction of The Spent Wash Condensate by Applying Sugar Cane Bagasse Ash
(SLIIT, Faculty of Engineering, 2024-10) Lankathilake, L.J.M.U.; Wijesekara, E.R.J.M.D.D.P.; Amarasinghe, A.M.P.
Distillery spent wash is a highly acidic waste generated during ethanol production in sugar industries. It makes a challenging industrial wastewater, due to its high organic content and complexity and it needs to treat before being released into the environment. The spent wash can evaporate, creating a thick slurry and vaporized liquid. The slurry can be used for different applications such as a fertilizer production. This vaporized fraction can be condensed, and this research study focuses on applying a sustainable waste management approach to reduce the COD of spent wash condensate by using ash generated from bagasse combustion. Four experiments were included in the study. First, H2O2-treated and untreated fly ash and bottom ash from the bagasse combusted boiler were mixed with the spent wash condensate and filtered out to determine the most suitable ash type for COD reduction. Then, the chosen ash type was used in various ratios and retention times to determine the optimum operation conditions. Finally, the COD reduction capacity of the boiler ash was determined by treating condensate multiple times. The results indicated that the optimum COD reduction spent wash condensate to treated bagasse fly ash ratio is 1: 50 (W/V), and the optimum retention time is 02 hours. Furthermore, the treated bagasse fly ash can be used twice to treat the condensate of distillery spent wash, and if it wants to be reused more, it should retreat with H2O2. The average COD value of raw spent wash was around 130,000 – 160,000 mg/L range, and it has reduced to approximately 70,000 mg/L in the spent wash condensate. After ash treatments the COD of spent wash condensate can be reduced to approximately 30,000 mg/L. This method can reduce the spent wash COD by about 75%; additional treatment is required to reduce it to an environmentally disposable level.
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Comparative Analysis of Characteristics of Dye-Sensitized Solar Cells Utilizing Extracts of Young vs Mature Leaves of Elaeocarpus Serratus as Natural Sensitizers
(SLIIT, Faculty of Engineering, 2024-10) Davisan, S.; Nupearachchi, C.N.; Perera, V. P. S.
This study addresses the pressing global need for sustainable energy sources by exploring dyesensitized solar cells (DSSCs) as a viable alternative. Specifically, the research focuses on extracting natural pigments from Elaeocarpus serratus (Sri Lankan olive) leaves to enhance the efficiency of DSSCs. These leaves undergo color changes as they mature, presenting opportunities to extract different types of pigments at different ages. Extraction involves boiling pieces of leaves in absolute ethanol to obtain the desired pigments. Further characterization via UV-visible spectroscopy revealed the presence of different absorption bands of pigments in the natural dyes’ extracts. The constructed DSSCs employed these natural dyes, coated on TiO2 films deposited on FTO glass plates as the photoanodes. The liquid electrolyte was I2/I3 - and a platinum-sputtered glass plate served as the counter electrode. Photovoltaic characteristics were evaluated using a computerized PK-IV 100 I-V analyzer under 100 W/m2 illumination. Results indicated the superior performance of DSSCs utilizing young leaf extracts, yielding a short circuit current density (JSC) of 3.950 mA/cm2, open circuit voltage (VOC) of 458.8 mV, and a fill factor (ff) of approximately 0.553 with an efficiency (η) of 1.003%. Conversely, DSSCs utilizing. Mature green leaf extracts exhibited lower performance metrics, with JSC of 2.379 mA/cm2, VOC of 477.5 mV, ff around 0.492, and η of 0.559%. Therefore, the efficiency of DSSC fabricated with young leaf is 56% higher than the DSSC made with mature green leaf extract.
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A Comprehensive 5G NR V2X Simulator for Unicast, Multicast, and Broadcast Communication Modes
(SLIIT, Faculty of Engineering, 2024-10) Dissanayaka, D.M.S.D.; Nethmini, K.G.M.; Dharmarathne, R.G.C.D.S.; Priyankara, W.N.B.A.G.
As the field of vehicular communication continues to evolve, the need for reliable and realistic simulation tools becomes increasingly critical. This paper introduces a novel 5G New Radio Vehicle to Everything (NR V2X) simulator, a state-of-the-art tool to emulate unicast, multicast, and broadcast communication modes. The simulator is built upon the well-established ns-3 network simulator and integrates seamlessly with the Simulation of Urban Mobility (SUMO) traffic simulator. This integration allows for the creation and analysis of complex vehicular communication scenarios, enhancing the realism and applicability of the simulations. One of the key features of our simulator is its flexible architecture. This flexibility enables it to accommodate a wide range of scenarios, making it a versatile tool for researchers and practitioners in vehicular communication. In addition to its technical capabilities, the simulator boasts a user-friendly interface. This interface enhances its accessibility, making it an easyto- use tool for researchers of all levels of expertise. We present an in-depth analysis of the performance of different communication modes under various scenarios. Key performance indicators such as average throughput, delay, and packet loss are evaluated, providing valuable insights into the intricacies of nextgeneration vehicular communication systems. Our work contributes significantly to the advancement of 5G NR V2X research. The simulator is a useful resource for exploring and understanding the complexities of vehicular communication systems, paving the way for future advancements in this exciting field. Our work will inspire further research and development in vehicular communication, bringing us one step closer to realizing the full potential of intelligent transportation systems.
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Computational Modelling of Drying Process in a Novel Solar Dryer Design with Experimental Validation
(SLIIT, Faculty of Engineering, 2024-10) Gunathilaka, R.A.C.K.; Kumar, R; Chatterjee, S; Bandara, R.M.P.S.
Crops and food products are dried by a variety of conventional methods, including open-air drying, smoking, and oven-drying for preservation purposes. Due to inherent drawbacks in the conventional drying methods, such as higher energy consumption, possible contamination and uncontrollable drying conditions, solar drying is preferred over the said drying methods. A solar dryer utilizes solar energy to dry crops, food products etc. by harnessing the heat energy from the sun to reduce the moisture content of the substances. The study focuses on modelling the drying process in an indirect type novel solar dryer through computational modelling with subsequent experimental validation of the temperature and air velocity profiles. The solar dryer is comprised of a divergent section, a convergent section, an absorber plate, a drying chamber, an outlet and trays. The Computational Fluid Dynamics (CFD) approach has been adopted in modelling the drying process and ANSYS Fluent has been used as the CFD tool. The computational mesh is comprised of 621,106 tetrahedral mesh elements. Pressurevelocity- coupling numerical scheme was used for discretizing the Navier-Stokes and other transport equations. A realizable k-ε model was applied in modelling turbulence. CFD simulations were conducted for three different mass flow rates of air: 0.0872 kg/s, 0.0636 kg/s, and 0.0447 kg/s at a solar insolation of 996 W/m². CFD simulations provided a comprehensive insight into the temperature and velocity profiles within the solar dryer. Furthermore, modelling results are well aligned with the experimental measurements taken on the solar dryer, confirming the reliability and accuracy of the computational model. The findings of this study will contribute as a platform for optimizing the performance of solar dryer designs.
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Computing Awareness and Computational Thinking in Sri Lankan Street Vendor Communities: A Pilot Study
(SLIIT, Faculty of Engineering, 2024-10) Perera, S.A.K.M; Munasinghe, B.
Although street market is a common and diverse form of informal economy in a country, the computing awareness and computational capacity of its contributing communities are largely understudied. This case study attempts to investigate the Computing awareness and Computational Thinking (CT) skills among street vendors in a Sri Lankan urban commercial area, using a mixed methods approach. It summarizes interviews, survey and observational findings about their digital literacy, digital awareness, problem solving skills and algorithmic thinking ability and the results are interpreted to understand their Computing awareness and CT skills. The findings reveal that Sri Lankan urban street vendors use digital devices, especially smartphones, for various purposes related to their vending activities, yet face concerns and challenges in accessing, affording, and trusting digital technologies. They seem to apply algorithmic thinking in planning, organizing, and optimizing their vending operations, and display problem-solving skills in coping with uncertainties, risks, and conflicts in their work environment, reflecting their resilience and adaptability. The study confirms that CT could be a valuable and relevant skill for street vendors and recognizing and nurturing these skills can enhance their socio-economic inclusion and resilience. The study also provides indicators for future research, such as exploring the gender and generational differences in both Computer awareness and Computational Thinking skills and evaluating the impact of educational interventions in those areas.
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Correlation of compressive strength and flexural tensile strength of blended cement concrete
(SLIIT, Faculty of Engineering, 2024-10) Kulathilaka, U. G. D. U.; Somaratna, N.
Eurocodes for structural designs have been adopted for Sri Lanka. Hence in Sri Lanka, concrete designs need to be in compliance with the relevant Eurocodes – mainly EN1992 (EC2). In EC2, concrete is categorized by its compressive strength. The other strength parameters are derived from the compressive strength using correlations based on empirical data. A recent trend has been the increasing use of blended cement for concrete in certain applications. But the correlations specified in EC2 are based on data probably related to Ordinary Portland Cement (OPC) concrete. It is important to examine whether the correlations listed in EC2 are applicable to blended cement concrete too. The present study was performed to experimentally examine the correlation of compressive strength and flexural tensile strength of blended cement concrete. A parallel study was conducted for OPC concrete to serve as a baseline reference. Standard beam and cylinder specimens of concrete were cast, cured, and tested for flexural tensile strength and compressive strength. Three different mix ratios were used. Each mix was tested twice. The same series of tests were conducted for blended cement (Portland Composite Cement – PCC) and for OPC. Experimentally measured values of flexural tensile strength were compared against their estimated values derived from the experimentally measured compressive strengths, using EC2 listed relationships. The analysis showed that in the case of both OPC as well as PCC, the measured values of the flexural tensile strength exceeded their estimated values based on EC2 relationships. But the testing conducted has been limited in the number of tests performed, the range of mix ratios, and the types of aggregate used. In order to affirm the general applicability of Eurocode 2 relationships for blended cement concrete also, additional more comprehensive testing is warranted across a wider span of mix ratios and aggregate types.
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The Current Status, Challenges, and Future Directions of Sustainability Assessment of Buildings in Sri Lanka
(SLIIT, Faculty of Engineering, 2024-10) Herath, M. R; Karunaratne, S
Buildings are currently responsible for 39% of global energy-related carbon emissions; 28% from operational emissions, and 11% from materials and constructions. Sustainability assessments of buildings to estimate the impacts become important for Sri Lanka to meet the national target of achieving socially inclusive, environmentally sustainable, and carbon-neutral housing by 2050. Life Cycle Assessment (LCA) is a powerful tool, which can be used to assess building sustainability. Hence a study was conducted to identify the current status, the challenges faced, and future suggestions for the sustainability assessments of buildings in Sri Lanka. A questionnaire survey was conducted to collect data among building construction professionals in Sri Lanka where 55%, 17.5%, 10%, 9.2%, and 8.3% were civil engineers, engineering consultants, quantity surveyors, academics, and architects out of 120 total respondents. More than half of the respondents, 52% have more than 15 years of building construction experience, and the rest 48% have experienced less than 15 years. The questionnaire consisted of 45 questions with three main segments to capture the respondents' experience in building sustainable assessment, its application, and the challenges faced in the attempt. According to the analysis, it was evident that there was a lack of performing sustainability assessments in Sri Lanka as only 15.8% of total respondents have experience in performing sustainability assessments of buildings, although more than 65% have moderate to expert knowledge in LCA. The reasons such as lack of policies and regulations and lack of knowledge and experience were the main causes for sustainability assessment not being popular within the industry. Sustainability assessment is important in benchmarking projects, reducing the emissions from the building sector while achieving nationally determined contributions by 2050.
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Data-Driven Bioclimatic Zoning in Sri Lanka: PCA and Clustering Analysis
(SLIIT, Faculty of Engineering, 2024-10) Nadarajah, P.D; Singh, M.K; Mahapatra, S
Driven by evolving lifestyles and the escalating demand for thermal comfort, Sri Lanka faces a critical absence of climate zone classifications necessary for constructing energy-efficient and climateresponsive buildings. This study addresses this gap by implementing bioclimatic zoning using a comprehensive 31-year weather dataset of 25 locations across the country. By applying Principal Component Analysis and Hierarchical Clustering to the 31-year weather data, Sri Lanka was classified into three distinct bioclimatic zones: Z1 (Hot and humid), Z2 (Cool and humid), and Z3 (Warm and humid). Bioclimatic potential analysis for each zone reveals natural ventilation as the most effective passive design strategy, demonstrating potential percentages of 64 ± 13%, 63 ± 10%, and 83 ± 4% in a year for Z1, Z2, and Z3, respectively. These findings underscore the crucial role of bioclimatic zoning in guiding the design of energy-efficient buildings in Sri Lanka. The approach contributes significantly to achieving national energy efficiency goals by leveraging climate-specific passive design strategies and reducing reliance on energy-intensive cooling systems. Moreover, the study not only classifies Sri Lanka into three bioclimatic zones but also emphasises the broader impact of implementing such strategies on sustainable construction practices. This research, therefore, stands at the intersection of bioclimatic zoning, sustainable building practices, and the evolving energy landscape.
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Design and Development of a 50kW Producer Gas Generator in Sri Lanka
(SLIIT, Faculty of Engineering, 2024-10) Perera, K.D.M; Ratnaweera, H.G.J.N.; Nilanka, A.A.P.
This research paper presents the design, fabrication, and experimental investigation of a downdraft gasifier system. The design of the system first required evaluation of various literature to select the correct gasifier type and the components of the gas conditioning system. The downdraft gasifier design was done by using existing gasifier designs in the literature and Sri Lanka. Further, a gas conditioning system comprising a cyclone separator and a wet-packed bed scrubber was designed and fabricated. The completed gasifier system was then tested to validate its capacity and to evaluate the thermal conversion efficiency. A maximum cold gas efficiency of 67% was achieved and the maximum capacity was 50.9kW. The capacity and cold gas efficiency were evaluated with the variation of the inlet velocity of the air nozzles. Further, the report consists of the operational manual and manufacturing procedure. A brief feasibility study was done regarding its applicability for a heating application and its financial assessment.
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Design Environments Inspiring Employee Satisfaction: A Comprehensive Study on Design Elements Rousing Satisfaction Levels with Special Reference To State Sector Offices in Homagama, Sri Lanka
(SLIIT, Faculty of Engineering, 2024-10) Pathirana, V.D.; Wijesundara, J
Though job satisfaction is one of the most studied facets of organizational behaviour, the involvement between its physical environment and satisfaction for work efficiency is seldom studied. A quality design fosters a less stressful and productive office environment. The employable community has proliferated with the development of the tech city in Homagama. Thus, a healthy office environment is essential for employees' eight-hour daily work duration. This paper aims to study how employees determine their satisfaction level within the work environment regarding different design elements. It investigates the extent of integration of identified design elements and discusses further necessary improvements. The research involved 84 employees across three state-sector offices in Homagama: the Divisional Secretariat Office, the Zonal Education Department, and the Medical Officer of Health. The examination will utilize on-site observation, an open-ended structured questionnaire and available literature. The perceived importance of different parameters will be clarified with the compatibility of the standard parameters of British standards. The results highlight a significant impact on employee satisfaction due to the lack of personal space, with additional factors including internal layout, furniture, circulation space, ventilation levels, and sanitary facilities. Furthermore, the study indicates that the perceived importance of design parameters equals or higher than the importance of satisfaction. In conclusion, prioritizing employee health and well-being in office spaces is crucial for improving overall well-being, efficiency, and reducing energy consumption. The paper suggested enhancing office design through the implementation of passive design principles and space utilization strategies. The insights will be useful for architects and facility managers to utilize the interior by improving the quality of productive, user-friendly, energy-efficient, and sustainable offices.
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Determination of Shrinkage of Mud Concrete
(SLIIT, Faculty of Engineering, 2024-10) Kuruppu, K.D.S.; Dharmaratne, P.D.; Galabada, H.G.
The research study systematically examined the shrinkage of mud concrete, aiming to evaluate its potential as an eco-friendly construction material. It investigated the influence of water-retarder admixture and coir fiber additions on dimensional changes, utilizing ASTM C157 as the test method. The study is required to address knowledge gaps in mud concrete shrinkage characteristics and provide guidance for its sustainable construction application. Three primary objectives were identified: analyzing shrinkage, determining optimal curing times for shrinkage minimization, and assessing the impact of fibers and admixtures on the shrinkage process. The mix design incorporated locally available soil, ordinary Portland cement, coconut fiber, water, and a water-retarder admixture (Plastolith 55R) to improve workability and structural integrity. Results indicated a consistent length reduction in all mud concrete compositions over time, with the water-retarder admixture and coir fiber effectively mitigating shrinkage. However, fiber addition was observed to increase shrinkage, necessitating further investigation. Wet curing conditions significantly reduced shrinkage compared to dry conditions, underscoring the importance of moisture content during curing. The study concluded by highlighting the crucial role of water-retarder admixture in reducing mud concrete shrinkage and enhancing longterm performance. It acknowledged the observed increase in drying shrinkage rate with fiber addition, emphasizing the need for additional research into underlying processes. Overall, the study provides valuable insights into sustainable construction practices by advocating for judicious additive use to optimize mud concrete compositions and calls for further research to explore fundamental mechanisms influencing shrinkage.
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Development of DSSC Counter Electrode Using PEDOT: PSS/GO Nanocomposite
(SLIIT, Faculty of Engineering, 2024-10) Ravindran, N. S; Wijayarathne, W. M. K. B. N; Chandrika, R. P.; Medagedara, A. D. T.; Kumara, G. R. A; Bandara, T. M. W. J.
Dye-sensitized solar cells (DSSCs) have garnered considerable research interest owing to their ability to achieve high photo-to-electric energy conversion efficiencies at a relatively low production cost. While platinum has been recognized for its exceptional electrocatalytic performance and efficiency as a counter electrode in DSSCs, its higher cost and vulnerability to corrosion have prompted the exploration of alternative materials to replace Pt in this role. DSSCs have demonstrated noteworthy photovoltaic performances by employing a range of candidate materials, including conducting polymers, carbon materials, and nanocomposites of conducting polymers and carbon materials, as counter electrodes. The motivation to form composites or hybrids with nanomaterials stems from the aim to improve the overall photovoltaic efficiency in DSSCs. The main objective of this study was to fabricate a DSSC utilizing a counter electrode comprised of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate and graphene oxide (PEDOT: PSS/GO). The fabrication of the counter electrode involved depositing the PEDOT: PSS/GO nanocomposite onto a graphite sheet using drop casting. The GO, which was synthesized through a modified version of Hummer’s method, underwent characterization via Raman spectroscopy and XRD analysis to ensure a successful synthesis process. The surface morphology and the Raman spectra of coated nanocomposites indicated the good dispersion of GO and the strong interaction between GO and the PSS chain, respectively. In the fabrication process of the DSSC, a gel polymer electrolyte was incorporated between a five-layer TiO2-based photoanode and the PEDOT: PSS/GO-based counter electrode. Photovoltaic performances of DSSCs were evaluated under simulated solar irradiance of 1000 W m-2. They were able to achieve a power conversion efficiency of 2.7%, Voc of 0.73 mV, Jsc of 5.21 mA cm-2, and a fill factor of 0.71.
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Driving Towards Sustainability During the Construction Phase of Roads in Sri Lanka by Mitigating CO2 Emission: A Systematic Literature Review Approach
(SLIIT, Faculty of Engineering, 2024-10) Yaparathnea, I.H.G.Y.M. Udari; Guruge, K
Climate change has become a pressing concern for humanity in the contemporary era. Scientists believe that the acceleration of global warming and climate change is directly linked to the rising concentration of greenhouse gases, particularly carbon dioxide (CO2). This has become a challenge for many developing countries. The construction industry is one of the sectors that significantly contributed to heightened carbon emissions into the environment. Road construction involves various activities and processes that release substantial amounts of CO2 into the atmosphere. Addressing these issues are crucial for mitigating the adverse effects of climate change and fostering sustainable development. The development of road infrastructure generates CO2 emissions across various stages. Notably, the construction stage is responsible for a significant portion of these emissions. Despite this, research efforts in Sri Lanka have primarily focused on reducing CO2 emissions in building construction projects, with limited attention to strategies specifically targeting road construction projects. The construction phase of road development has thus far been overlooked in terms of CO2 emission reduction strategies. Consequently, this study seeks to raise awareness among academics, professionals, and practitioners involved in road development projects about the factors influencing CO2 emissions during the road construction phase. The objectives of this study are to examine the factors affecting CO2 emissions during road construction development, identify the activities and processes contributing to CO2 emissions during the construction phase of road projects, explore existing sustainable strategies used in road construction to mitigate CO2 emissions, and assess their applicability to the Sri Lankan Road construction sector. A systematic literature review was conducted to achieve these objectives, selecting the fifty-six most relevant past research studies.
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Efficiency Enhanced by Chelation of Al3+ Metal Ions with Erythrina Fusca Flower Dye Harnessing Bathochromic Shift
(SLIIT, Faculty of Engineering, 2024-10) Mannawadu, M.W.M.K; Perera, V.P.S.
Utilization of natural dyes in dye-sensitized solar cells (DSSCs) presents a sustainable approach towards enhancing photovoltaic efficiency. This study explores the bathochromic shift exhibited by Erythrina fusca (Erabodu) flower dye upon chelation with Al3+ ions, offering an innovative strategy for improving DSSC performance. 20g of chopped flower petals was boiled with 50ml of ethanol until flower petals become pale in colour in the dye extraction process. After that, 0.1 M, AlCl3 solution was added dropwise to 2ml of dye solution until the colour changed to purple. The pH value of Erabadu bare dye was recorded as 5.47 and with the Al3+ ion addition it was changed to 4.49. Through spectroscopic analysis and electrochemical characterization, the chelation mechanism and its impact on dye absorption spectra and electron transfer dynamics was elucidated. The Dye was coated on a thin film of TiO2 nanoparticles deposited on fluorine-doped tin oxide (FTO) glass plates. FTO glass which coated with platinum was used as the counter electrode and iodin/triiodide (I2 / I3 -) was used as the electrolyte. Solar cell was tested with a light source with an intensity of 100 mW/cm2. Al3+ ion chelated Erabadu dye exhibited higher efficiencies than bare dye which was 1.627%. The open circuit voltage (Voc) of this cell was 470mV, short circuit current density (Jsc) was 4.00 mA/cm2 and the fill factor of DSSC’s was 0.553. The Incident Photon to Current Conversion Efficiency (IPCE) of the cell further revealed the action spectrum was broadened between 300 nm – 500 nm enhancing the efficiency. Our findings unveil the potential of Al3+ ion chelated Erythrina fusca dye as a promising sensitizer for DSSCs, paving the way for eco-friendly and efficient solar energy conversion.
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Empowering Urban Resilience: Innovative Architectural Solutions for Sustainable and Affordable Low-Income Settlements in Sri Lanka
(SLIIT, Faculty of Engineering, 2024-10) Perera, W.M.B.I.U
Low-income settlements’ are emerging as an upcoming situation within the current economic situation within Sri Lanka, which makes people’s lives even harder to fulfill their basic needs. Within such a scenario of rising living cost issues within the country, most people tend to accept the implementation of ‘low-income settlements’ which are not the fulfillment of the essentiality in facilitiesthat need to exist within a properly constructed house. This study intends firstly, to assess the current architectural issues and their implications that impoverished people, secondly, to find creative, affordable, and environmentally friendly housing prototypes that are suited to the requirements and thirdly, to engage with swaying the residents' hearts and minds toward capturing innovative, affordable, and sustainable housing solutions. This will be conducted as a case study by specifying the community of Lake Crest Residence, Mandawila, and another housing scheme in Borella, near to Grama Niladhari Office, Narahenpita as destinations for thegreater emergence of low-income housing settlements. Respective data would be gathered based on primary sources of semi-structured interviews from the community. This presents a detailed analysis of prevailing architectural issues and their implications to suggest creative, affordable, and environmentally friendly housing solutions. Therefore, the researchfindings can be utilized to improve the current standard of living of these dwellers to sustain the qualityof their lives within the challenge of increasing global population.