Journal of Advances in Engineering and Technology [JAET] Volume 03 Issue i
Permanent URI for this collectionhttps://rda.sliit.lk/handle/123456789/3946
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Publication Open Access Optimizing the Financial Risk Management Strategies in Water Supply Projects in Sri Lanka(SLIIT, Faculty of Engineering, 2025-01) Senanayake, U. S; Wijesinghe, T.; Perera, B. K. C.; Jayasinghe, Y. M.Infrastructure construction projects are considered highly susceptible to risks and uncertainties due to their complicated designs, sizes, functions and structural complexities. Among the different types of risks, the financial risks and the ability to manage them will have great implications for the cost performance of the relevant infrastructure projects. Therefore, high attention is paid to the financial risk management aspect of public infrastructure projects. In that concern, water supply infrastructure projects share several characteristics in common with other infrastructure construction projects while holding several other characteristics unique to themselves. Although many studies have been conducted on financial risk management in building and infrastructure projects, observed scanty of studies that address the financial risk management aspects of water supply projects in the Sri Lankan context. Therefore, this study is meant to fill significant void in terms of developing a financial risk management framework to address financial risk factors in Sri Lankan water supply projects. In carrying out this study, a mixed methodology was followed under an exploratory sequential design. Accordingly, the risk factors and risk management strategies identified in the reference literature were screened and shortlisted for their applicability in designing water supply projects in Sri Lanka and were validated through findings achieved at interviews with experts capable of highlighting new risk financial factors and strategies unique to the water supply projects in Sri Lanka. Subsequently, the risk factors and strategies identified in this process are mapped to develop a financial risk management framework for implementation of water supply projects in Sri Lanka in the future.Publication Open Access Use of Ascorbic Acid Linker in Enhancing the Photovoltaic Performance of CdS/TiO2 Quantum Dot Sensitized Solar Cells(SLIIT, Faculty of Engineering, 2025-01) Ajward, N.F.; Davisan, S.; Perera, V.P.S.This study explores the use of ascorbic acid to enhance the photovoltaic performance of CdS/TiO2 Quantum Dot Sensitized Solar Cells (QDSSCs). Ascorbic acid acts as a mild reducing agent, donating electrons to Ti atoms on the TiO2 film, effectively filling oxygen vacancies known to act as recombination centers for photogenerated charge carriers. By passivating these detrimental sites, ascorbic acid facilitates improved carrier transport and reduces recombination, ultimately boosting photocurrent and overall efficiency. QDSSCs fabricated via the Successive Ionic Layer Adsorption and Reaction (SILAR) method were characterized using I-V measurements, Incident Photon to Current Conversion Efficiency (IPCE), Impedance Spectroscopy (IS), and overall power conversion efficiency. The optimized cell incorporated with ascorbic acid demonstrated a remarkable improvement compared to the control, achieving a short circuit current density (Jsc) of 4.863 mA/cm², open circuit voltage (Voc) of 446.1mV, efficiency of 1.368%, fill factor of 24.6%, and maximum power of 0.342mW. Optimization of ascorbic acid absorption time and precursor concentrations resulted an impressive 68.26% enhancement in efficiency (from 0.813% to 1.368%) and increase in maximum power from 0.163 mW to 0.342 mW for 0.64 cm². cell. This study highlights the potential of ascorbic acid as a simple and effective strategy for enhancing the performance of CdS/TiO2 QDSSCs, paving the way for further developments in low-cost and efficient solar cell technologies.Publication Open Access Advancing Audio Surveillance in Simulated Environments: Real-World Soundscapes and Targeted Noise Detection through Enhanced Beamforming Techniques(SLIIT, Faculty of Engineering, 2025-01) Stroud, S; Jones, K; Edwards, G; Robinson, C; Chandler-Crnigoj, S; Ellis, DThis paper introduces an innovative beamforming approach designed for audio surveillance, executed through a virtual simulation of a real-world environment based at Liverpool John Moores University. Our research is driven by the increasing requirement for sophisticated audio analysis methods to isolate and enhance specific sounds within noisy environments for forensic analysis, for example, in criminal court cases. By leveraging a time-delay beamforming algorithm, our work offers a novel solution to discern and amplify targeted noises amidst complex soundscapes, a challenge commonly encountered in urban surveillance and forensic audio analysis. Our approach's foundation lies in utilising a carefully arranged, robust array of omnidirectional microphones, which are instrumental in capturing a wide range of real-world sound signals. The core of our methodology involves processing captured sounds using the proposed algorithm, followed by evaluating the system's effectiveness in capturing the desired localised audio sources. This paper explores the system's resilience against microphone array degradation, showcasing its robustness in scenarios of partial system functionality. The experiments, grounded in the simulation of real-world acoustic environments, demonstrate the algorithm's adeptness at managing sound reflections and reverberation, critical factors in the realistic replication of urban soundscapes. It also considers the broader implications of our findings, exploring the potential for adopting this technology in various domains beyond law enforcement, including broadcast solutions, advanced audio engineering applications, and animal conservation in the wild. In conclusion, this research showcases a creative approach to audio surveillance and opens the door to numerous applications that can benefit from enhanced methods of audio isolation and analysis. Our findings contribute to the ongoing discourse on developing advanced surveillance technologies, offering insights that could help shape the future of audio processing and analysis.Publication Open Access How Frequency and Harmonic Profiling of a ‘Voice’ Can Inform Authentication of Deepfake Audio: An Efficiency Investigation(SLIIT, Faculty of Engineering, 2025-01) Williams, E.L; Jones, K.O; Robinson, J.C; handler-Crnigoj, S; Burrell, H; McColl, SAs life in the digital era becomes more complex, the capacity for criminal activity within the digital realm becomes even more widespread. More recently, the development of deepfake media generation powered by Artificial Intelligence pushes audio and video content into a realm of doubt, misinformation, or misrepresentation. The instances of deepfake videos are numerous, with some infamous cases ranging from manufactured graphic images of the musician Taylor Swift, through to the loss of $25 million dollars transferred after a faked video call. The problems of deepfake are becoming increasingly concerning for the general public when such material is submitted into evidence in a court case, especially a criminal trial. The current methods of authentication against such deepfake evidence threats are insufficient. When considering speech within audio forensics, there is sufficient ‘individuality’ in one’s own voice to enable comparison for identification. In the case of authenticating audio for deepfake speech, it is possible to use this same comparative approach to identify rogue or incomparable harmonic and formant patterns within the speech. The presence of deepfake media within the realms of illegal activity demands appropriate legal enforcement, resulting in a requirement for robust detection methods. The work presented in this paper proposes a robust technique for identifying such AI-synthesized speech using a quantifiable method that proves to be justified within court proceedings. Furthermore, it presents the correlation between the harmonic content of human speech patterns and the AI-generated clones they produce. This paper details which spectrographic audio characteristics were found that may prove helpful towards authenticating speech for forensic purposes in the future. The results demonstrate that using specific frequency ranges to compare against a known audio sample of a person’s speech, indicates the presence of deepfake media due to different harmonic structures.Publication Open Access Optimization of Essential Oil Extraction Using Pomelo Peels as the Raw Material: A Process Study(SLIIT, Faculty of Engineering, 2025-01) Perera, W.P.S. N; Arachchige, U.S.P.R; Koliyabandara, P.AEssential oils are natural extracts known for their versatility, capturing widespread interest due to their diverse applications and the increasing consumer preference for safe and efficient health solutions. Their inherent natural properties make them valuable in various industries, including food, pharmaceuticals, agriculture, and textiles. In that respect, this research focuses on optimizing essential oil extraction using waste pomelo peels as the raw material. There two extraction methods, water distillation and Soxhlet, were employed to investigate the feasibility of utilizing pomelo peels for essential oil extraction. The main objectives that were meant to be achieved in this research included comparing the efficiency of water distillation and Soxhlet extraction methods, optimizing the essential oil extraction process by adjusting vital physical parameters, and determining the most effective pomelo peels. The waste pomelo peels required for oil extraction were collected around the Colombo district (Sri Lanka). Two distillation setups were used for water distillation: industrial-scale water distillation and lab-scale water distillation apparatus. The investigations revealed that Fresh-Grind pomelo peels exhibited notably higher efficiency for water distillation, with a yield of 0.8%. There the oil extraction yield for the industrial and laboratory extraction setup was reported as 0.5% and 0.8%, respectively. The Soxhlet experiments were conducted using various solvents: toluene, acetone, n-hexane, methanol and acetonitrile. However, based on the experiment results, n-hexane emerged as the most effective, yielding an efficiency of 7.1%. So, the Soxhlet extraction method was selected to optimize the process followed in essential oil extraction by waste pomelo peels.Publication Open Access Fabrication, Characterization, and Gas Sensing Properties of Different Semiconductor Metal Oxide Nanostructures for LPG Detection: A Comparative Study(SLIIT, Faculty of Engineering, 2025-01) Bandara, A.H.M.N.N.; Senadeera, G.K.R.; Bandara, K.N.D.; Perera, V.P.S.The research explores how the structural, morphological, and electrical properties of nanostructured semiconductor metal oxides (SMOs), including Cu2O, ZnO, TiO2, and reduced graphene oxide (rGO), synthesized via electrochemical deposition and doctor blading techniques, influence their effectiveness in sensing liquid petroleum gas (LPG). Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis were used to assess the chemical composition and structure. Cu2O, ZnO, and TiO2 were found to exhibit significant polycrystalline structures, with increasing average crystallite sizes of approximately 42.8 nm, 70.1 nm, and 87.78 nm, respectively. The dominant (111) Cu2O phase displayed a homogeneous cuboid morphology. rGO exhibited a singleplane (002) microstructure with a crumpled paper texture and an average crystallite size of ~85.3 nm, indicating a successful hydrothermal reduction of graphene oxide (GO). UV-vis absorption spectra in the range of 200 – 800 nm revealed the presence of different energy bands in ZnO, TiO2, and rGO, alongside their major band energies of 3.2 eV, 3.3 eV, and 1.9 eV. Cu2O thin films, with the lowest band energy gap of 2.5 eV, exhibited high photocatalytic activity, potentially enhancing chemical reaction rates during gas sensing under light exposure. Additionally, alternating current (AC) impedance spectra of SMO indicated increased film conductivities with positive bias voltages. ZnO films showed the most significant gas response (~27%) for LPG sensing at 70 ℃, with response and recovery times of less than 20 seconds. A stable and considerably high LPG sensitivity of ~11% was discovered with Cu2O. This finding underscores the significance of its relatively small grain size in influencing its sensitivity to LPG.Publication Open Access Pneumonia Detection and Lung Disease Assessment from Chest X-rays: Developing A Diagnostic Support System(SLIIT, Faculty of Engineering, 2025-01) Jayawardena, C.A; Wedasingha, N; Kolambage, N; Perera, SThis research, dedicated to developing an accurate and efficient pneumonia detection system from Chest X-Ray images, highlights the significance of automated tools in enhancing healthcare diagnostics. Its significance lies in the fact that pneumonia is a prevalent respiratory condition that requires timely and accurate diagnosis for effective medical intervention. The project's objective was to make use of convolutional neural networks and image analyses to create an automated diagnostic tool that could assist healthcare professionals in identifying pneumonia with precision and efficiency. To achieve this, the system initially made use of two custom deep learning architectures but ultimately used a pretrained CheXNet-based model, developed by using transfer learning. This choice was made by considering CheXNet’s proven performance in identifying pneumonia and other pulmonary conditions. The project's results proved promising, with the CheXNet-based model achieving high diagnostic accuracy and providing valuable insights into the presence of pneumonia. The system's architecture, using deep learning and the use of DICOM images, demonstrated its effectiveness in improving the accuracy and efficiency of pneumonia diagnosis. Based on the results, this paper further demonstrates a web-based application for interaction with the system. Additionally, it provides information on the work that could be done in the future. Thus, this research contributes to the growing field of medical image analysis and highlights the significance of automated tools in enhancing healthcare diagnostics. The project's outcomes are meant to pave the way for more efficient and accessible methods for pneumonia detection, ultimately benefiting both healthcare providers and patients.Publication Open Access Factors Influencing the Service Quality Expectations of Bus Passengers: Evidence from a Suburban Bus Route in Sri Lanka(SLIIT Faculty of Engineering, 2025-01) Nirodhaka, P J T P; Abhayasinghe, B A K N; Palansooriya, P G W W H M R S; Nirmal, H D T; Sharic, A H SThe decline in public transportation usage in Sri Lanka, due to inadequate service quality, reflects significant challenges for suburban mobility. Against this background, this study investigates the factors influencing bus passengers' service quality expectations on the Mawanella-Rambukkana bus route, providing insights into the need of improving public transport services at suburban levels. The existing literature indicates the key service attributes such as the ticket price, waiting time, and environmental conditions that significantly affect passenger satisfaction. However, there is a gap in understanding these factors in suburban contexts, particularly gender-specific preferences in Sri Lanka. A conjoint analysis was conducted to evaluate six critical service quality attributes: walking time, waiting time, ticket price, travel time, in-bus environment, and bus stop environment. The data was collected from 400 passengers, including 197 males and 203 females, using a structured questionnaire. The utility estimates and relative importance scores quantified the impact of each attribute. The study revealed a significant set of gender differences in service quality priorities. The ticket price emerged as the most crucial factor for both genders, with a slightly higher importance for the females (27.125) than the males (26.807). The males valued the bus stop environment (19.189) more than the females (19.065), while the females prioritized the in-bus environment (17.822) more than the males (17.044). The waiting time was more critical for the males (14.485) compared to the females (13.981), while walking time and travel time were of lower importance for both genders. The findings underscore the need for certain public transport actions such as targeted improvements in fare affordability, waiting times, and environmental conditions to enhance passenger satisfaction. The study addresses thus an existing literature gap by focusing on suburban bus passengers and providing gender-specific insights, contributing to a comprehensive understanding of the public transport service quality experienced by the people of Sri Lanka.