Journal of Advances in Engineering and Technology [JAET]
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The Journal of Advances in Engineering and Technology (JAET) is an international, open access, double blind peer-reviewed journal. It is published by the Faculty of Engineering of Sri Lanka Institute of Information Technology (SLIIT). The JAET aims at fostering research and development work in Engineering and Technology and bringing researchers on to a common platform. Furthermore, JAET will also accept review articles on appropriate subject areas including concept papers of academic opinions, book reviews, etc. for publication therein.
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Item Open Access Synergistic Charge Dynamics and Light Harvesting in TiO₂/MgO Composites for Efficiency Enhancement in CdS Quantum Dot-Sensitized Solar Cells(Faculty of Engineering, 2026-01) Ajward, N.F.; Fernando,J.V.P.; Perera, V.P.S.Quantum dot-sensitized solar cells (QDSSCs) represent a promising advancement in renewable energy technologies, with recent improvements achieving power conversion efficiencies close to 6%. Structurally similar to dye-sensitized solar cells (DSSCs), QDSSCs employ quantum dots (QDs) as sensitizers that absorb photons and inject excited electrons into the conduction band of a wide-bandgap semiconductor electrode, while the redox electrolyte removes the generated holes and completes the circuit through regeneration at the counter electrode. Quantum dots composed of materials such as CdS, CdSe, PbS, and InP are increasingly studied for use in QDSSCs, offering the advantage of tunable optical band gaps through particle size manipulation. This adaptability enhances QDSSCs’ design potential, enabling the integration of third-generation solar cell configurations, including multiple exciton generation (MEG), to further improve energy conversion efficiency. Despite these advancements, QDSSC performance is currently limited by issues such as reduced photovoltage and recombination losses at the TiO₂-QD-electrolyte interface. This study investigates the effect of MgO incorporation into TiO₂ photoanodes on the photovoltaic performance of CdS QDSSCs, with particular attention to the fill factor (FF) and overall cell efficiency. MgO is expected to act as an interfacial passivation layer suppressing combination and improving charge-selective transport. In addition, MgO may enhance light scattering within the photoanode, thereby improving light harvesting and short-circuit current density. In this study, MgO powder was incorporated in specific mass ratios with TiO₂, followed by the application of CdS quantum dots (QDs) on the TiO₂/MgO composite layer using the SILAR method. Results indicated a significant improvement in the fill factor (FF) at an optimal MgO-to-TiO₂ ratio, attributed to synergistic effects of MgO on interface stabilization, reduced recombination, and enhanced charge transport. The optimized MgO-modified TiO₂ films achieved a current density of 1.95 mA cm-2, voltage of 437 mV, and power of 0.121 mW (active area = 0.49 cm²), reaching an efficiency of 0.311 % (18.7% higher than TiO₂/CdS QDSCs), with improved interfacial impedance, Incident Photon to Current Efficiency (IPCE), and FF of 0.374.Publication Open Access Efficient Ventilation Configurations for an Isolation Ward in View of Reducing the Potential Contamination of Its Occupants(SLIIT, Faculty of Engineering, 2023-03-02) Durage, H; Attalage, R; Bandara, R.M.P.S.The rise of respiratory infections, such as the SARS epidemic in 2003, and the H1N1 influenza epidemic in 2011, highlighted the importance of efficient ventilation in healthcare facilities. The novel SARS -Cov-2 disease has sparked many concerns over the ventilation performance of multi-bed isolation wards and their ability to suppress airborne infectious contamination. The study is primarily based on suggesting ventilation improvements for a locally acquired multi-bed intensive care isolation unit. The study via ANSYS -fluent incorporates a k-𝜀 turbulent model that is used to analyze exhaled CO2 particle tracks of 4 human models. Three ventilation strategies, namely, Displacement, Stratum, and Curtain -Air-jet are initially considered and evaluated based on two indoor air quality indices (IAQs), namely, air change efficiency and contaminant removal effectiveness. Stratum ventilation comfortably exhibits unidirectional flow characteristics with an air change efficiency of 0.946, which was obtained through ANSYS -CFX while each suggested configuration is capable of achieving a contaminant removal effectiveness value greater than 1 which depicts that the contamination source is not in a perfect mixing zone. Results provided inconclusive evidence to draw correlations between the two IAQ indices and thus it is confirmed that these indices solely depend on the type of ventilation strategy. Contaminant concentration on health care worker breathing plane and exhaled particle tracking for 4 minutes in each analyzed configuration revealed that both Stratum and Curtain air-jet models improve the escaped particle efficiency by 25% and 29% respectively compared to the base model. These models are further compared against reference values specified by guidelines to evaluate their suitability for real-world operation.