Faculty of Engineering-Scopus
Permanent URI for this collectionhttps://rda.sliit.lk/handle/123456789/4893
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Item Embargo The Impact of Interior Design Environment on Employee Satisfaction: An Insight on State Offices in Sri Lanka(Springer Science and Business Media Deutschland GmbH, 2025) Kalpani K.I.; Ratnayake J.C; Wimalaratna P.L.; Wijesundara JJob satisfaction is crucial in corporate settings, as it influences employees’ attitudes and performance. While previous studies have highlighted the importance of workplace conditions on job satisfaction across various countries, there is a notable lack of research within the Sri Lankan context, particularly in state offices. This research investigates the factors affecting employee satisfaction in Sri Lankan state offices, with a specific emphasis on interior design environment. The study aims to determine how specific interior design environmental cues impact employee satisfaction. Based on a comprehensive literature review, the independent variables identified include floor layout, furniture arrangement, lighting, colour scheme, air temperature, noise and acoustics. This study employs a mixed-method approach, combining quantitative and qualitative data, to explore the impact of the interior design environment on employee satisfaction in three high-profile state offices in Colombo and Sri Jayewardenepura. Primary data were collected through observations and structured questionnaires distributed across various departments, yielding 50 responses from each office, resulting in a total sample size of 150 participants. On-site measurements for lighting levels, temperature, and noise levels, were taken, while furniture, colour, and floor layout were assessed through visual inspections. Questionnaire responses were analysed using SPSS statistical software. The research found that floor layout, furniture, lighting, and colour significantly impact employee satisfaction, whereas temperature and noise have minimal impact. The study offers design recommendations to improve state office environments, emphasizing the importance of passive design techniques to enhance user-friendliness and environmental sustainability, ultimately increasing employee satisfaction. This research fills a critical gap in the literature and provides practical insights for improving the working conditions in Sri Lankan state offices.Item Open Access Lean integrated circular economy in the Sri Lankan construction industry: a qualitative Delphi study(Ceylon Institute of Builders, 2025) Vijayakumar, H; Ranadewa K.A.T.O; Weerakoon, P; Weerakoon, P; Jayanetti J.K.D.D.TThe construction industry is known for its significant environmental impact and waste generation. To address this issue, the concept of Circular Economy (CE) has emerged, aiming to minimise waste and maximise resource utilisation. However, there are several barriers which impede the implementation of the CE concept in the construction industry. Therefore, this research aims to incorporate the lean concept to overcome the barriers of CE implementation in the construction industry. Therefore, this research develops a framework for a lean-enabled CE in the construction industry. The qualitative approach is used for this paper, and the Delphi technique was adopted. Purposive sampling was used to select the experts for the study, and data were analysed through manual content analysis. The findings revealed 10 benefits from CE and 12 benefits from Lean were identified, along with 8 benefits of CE and Lean integration. Furthermore, 19 barriers were identified towards this integration, and 12 strategies were identified to overcome these barriers. This study also provides a comprehensive mapping between CE and Lean implementation benefits, their integration benefits and barriers, and strategies. In addition, integrating lean and CE for the construction industry can lead to many significant benefits, such as cost savings, improved environmental performance, and enhanced stakeholder engagement.Item Open Access Assessment of Influence of Flow Regime on Heat Transfer Capacity of A Shell and Tube Heat Exchanger Using Computational Fluid Dynamics Analysis(Avestia Publishing, 2025) Ushettige S.A.P; Wimalsiri W.K; Hikkaduwa H.G.SShell and tube heat exchangers (STHX) are widely adopted in industrial thermal systems due to their reliability and performance. As such thermo-mechanical design and sizing of these devices has become a continuously expanding and existing research domain. Following technological advancements, CFD is now widely adopted for flow analysis and design. An upcoming area as of recent is the integration of tools such as non-linear least squares regression and CFD to develop correlations capable of predicting thermal performance based on the input design parameters such as Re and Pr. However, limited applications exist for STHXs. This study focuses on the development of thermal correlations in the form of Nu = C.Rea.Prb for a small TEMA E-type STHX. For these devices, turbulence is identified as a key parameter which affects thermal and mechanical performance and is often introduced by using metal plates known as baffles. Single segmental baffles which are widely used in industry are integrated into the design. Hence, turbulence is varied as a function of both the mass flow rate and the central spacing among the baffles. CFD Modelling in ANSYS-Fluent is conducted in the steady state for six, eight, ten and twelve baffles. Following CFD analysis the data is fit using non-linear least squares regression in MATLAB Curve-Fitter Toolbox generating four correlations with applicable operating ranges. The results of the goodness of fit were reasonable, however, high 95 % confidence interval widths were evident for certain fitted coefficients leaving further potential for improvement. The work conducted highlights that the application of CFD combined with numerical tools such as non-linear least squares regression can act as an aid in the design and optimization of heat exchangers, increasing design potential for engineers and researchers.Item Embargo Dual-Hop Hybrid Communication for Underwater and Terrestrial Systems: A Study on VLC and RF/FSO/THz Integration(Institute of Electrical and Electronics Engineers Inc., 2025) Rajahrajasingh, H; Jayakody, D.N.K; Tsiftsis, T.AThis paper presents an analysis of dual-hop hybrid communication systems that integrate Visible Light Communication (VLC) for underwater transmission with three different terrestrial communication technologies. Specifically, we compare the performance of VLC with radio frequency (RF), free space optics (FSO), and terahertz (THz) communication in a cooperative framework involving a floating buoy as a relay node. Our results demonstrate that the THz-VLC combination significantly outperforms both the RF-VLC and FSO-VLC configurations in terms of Outage Probability (OP) and overall system efficiency. This work provides valuable insights into optimizing communication pathways in hybrid underwater-terrestrial environments, highlighting the potential of THz technology for enhanced data transmission.Item Open Access THE APPLICABILITY OF CARBON EMISSION ESTIMATION WITH BIM ENVIRONMENT: SRI LANKAN CONTEXT(Ceylon Institute of Builders, 2025) Perera D.A.M.V; Allis C; Perera B.K.C; Lokuge AThe global construction industry is increasingly adopting sustainable practices and advanced technologies to enhance efficiency and reduce environmental impacts. Within this context, managing carbon emissions has emerged as a critical component of sustainable development, with Building Information Modelling (BIM) serving as a pivotal tool in this pursuit. While developed countries have already integrated BIM and carbon emission estimates, there is a notable opportunity for similar advancements in developing countries, potentially leading to significant progress within the industry. Hence, this paper aims to explore the applicability of implementing BIM for carbon emission estimations in the Sri Lankan construction industry. A comprehensive review of existing literature identified the importance of carbon emission simulations, BIM implementation strategies and estimation procedures in other countries. Further, this research involved a survey to assess the familiarity and experience levels of construction professionals with BIM tools for carbon emission estimations in Sri Lanka. Findings from the research point to Autodesk Insight as the primary software tool used within the industry. While the industry demonstrates an awareness of these processes, its progress is hampered by a lack of experience in using these technologies for carbon emission estimation scenarios and the absence of crucial databases such as Environmental Product Declarations. The study recommends enhancing industry capacity through targeted training and the adoption of advanced tools. It also encourages further research to assess the compatibility of BIM technologies in the local context, aiming to bridge the gap and drive sustainable transformation in Sri Lanka’s construction sector.Item Embargo Relative Tsunami Vulnerability of Structural Materials Across Tsunami Events(Institute of Electrical and Electronics Engineers Inc., 2025) Ukwaththa U.J.; Dias W.P.SThe influence of structural material on tsunami vulnerability is well established. However, there are shortcomings in incorporating this effect into vulnerability models. This study was conducted to compute the overall building damage due to a tsunami from fragility curves and replacement cost coefficients, and to identify the influence of different structural materials on structural vulnerability. The damage curves were of negative exponential form, with the influence of differing structural materials characterized by the single parameter defining those curves, i.e. the 'n' value. The results confirmed the established knowledge that vulnerability increased from RC through steel and masonry to timber structures. More importantly, they highlighted the fact that relative vulnerability is coupled with inundation depth, since, at depths approaching around 6 m, all materials will incur similar heavy damage. The most important finding of this work is that there is less modelling variance across tsunami events if a relative vulnerability approach is used (with each material compared to reinforced concrete), rather than using a mean 'n' value for each material across all tsunami events.Item Open Access BARRIERS AND SOLUTIONS TO ADOPTING DIGITAL TWIN IN SRI LANKAN CONSTRUCTION(Ceylon Institute of Builders, 2025) Indunil H.T.T.A; Bandara R.P.H.S; Buddhini P.H.Y.In the Industry 4.0 era, Digital Twin (DT) technology has emerged as a key innovation, integrating physical assets with their digital counterparts to enhance coordination, safety, and cost management in construction. Despite its potential, DT adoption in construction remains limited, particularly in developing countries like Sri Lanka, due to high costs, technological barriers, and a lack of standardized integration methods. While DT has significantly improved efficiency in other sectors, the construction industry still lacks practical large-scale applications and a unified framework for implementation. This research aims to explore the applicability of DT in Sri Lankan construction projects. Moreover, semi-structured expert interviews were conducted with 7 experts to gather data. Accordingly, the literature review and insights gathered from interviews highlighted its current usage, benefits, and barriers, and proposed 8 practical solutions to facilitate broader adoption of DT in the Sri Lankan construction industry. The findings of this research are anticipated to contribute significantly to the effective integration of DT technology within the Sri Lankan construction sector. The results underscore the promising role that DT can fulfil in addressing a variety of barriers confronting the construction industry. This study not only emphasizes the critical importance of adopting Digital Twin technology but also seeks to raise awareness of its potential, thereby encouraging its utilization and ushering in a new era of innovation in the Sri Lankan construction industry.Item Embargo A Non-Intrusive and Cost-Effective IoT-Based System for Smart Monitoring of Power Consumption(Institute of Electrical and Electronics Engineers Inc., 2025) Jayasooriya, S; Malasinghe, LElectrical utility companies in developing countries traditionally employ non-smart energy meters to measure their users' electricity consumption, with billing conducted on a monthly or quarterly basis. However, there is an emerging market, especially in developing countries, for customers to measure their day-To-day energy usage, similar to how they track their internet data consumption. This project aims to contribute to addressing this demand by designing and developing a non-intrusive and cost-effective ESP-32-based optical measuring device that can autonomously and accurately take imagery measurements from electrical utility meters, carry out cloud-based extraction of data using optical character recognition and transmission to an interactive web application for users to access their current and historical electricity usage records remotely in a more informative way.Item Open Access Single board computer and adapted 3D-printed case-based low cost and compact optical coherence tomography(SPIE, 2025) Seong, D; Han, S; Kim, Y; Hong, J; Wijhesinghe, R. E; Jeon, M; Kim, JOptical coherence tomography (OCT) is a non-invasive, label-free imaging method based on high-resolution interferometric optics that allows real-time visualization of morphological structures and depth-resolved images. The high cost of most commercially available OCT systems limits their widespread use, especially in resource-poor settings. Miniaturization of OCT devices therefore reduces not only size but also cost and has the potential to open new markets for this technology. In this study, we developed a small, portable 3D printed OCT system (SBC-OCT) based on a single-board computer. To reduce the cost to configure the system, the whole case of SBC-OCT is made with 3D-printed architecture. Using an area camera to avoid thermally induced alignment distortions in the spectrometer during system operation, the spectrometer is temperature insensitive, requires no hardware changes or additional components, and requires minimal computational effort. An applied automatic signal correction method was developed. The smaller size, lighter weight, and lower cost of SBC-OCT highlight its significant relevance in medical, industrial, and security applications, showcasing its potential for broad adoption.Item Embargo Experimental Investigation on a Surface Treatment Technique to Enhance the Performance of Calicut Tile Aggregates(Springer Science and Business Media Deutschland GmbH, 2025) Kishotharan S; Somarathna H.M.C.C; Kaashif M.M.M.; Johnkeshanth JThe acceleration of urban development has noticeably escalated construction activities and the requisition for concrete, which predominantly depends on natural aggregates. In light of the finite access to these natural resources, investigative alternate materials that preserve the mechanical robustness of concrete is imperative. Scholarly investigations reveal that the incorporation of Calicut Tile Aggregates (CTA) as a renewable substitute for Natural Coarse Aggregates (NCA) in concrete compositions up to 40% of NCA is feasible with negligible detriment to performance. The objective of the present study is to enhance the properties of CTA through a surface treatment technique, specifically a cement sand coating, to amplify its compatibility and adhesion with the cement matrix. The methodology encompasses immersing the fragmented CTA in water for 24 hours, followed by the application of a coating of a mix of one part cement to two parts sand, and subsequently curing the coated aggregates for 28 days. The proposed treatment has been shown to enhance the physical and mechanical properties of CTA, endorsing its application as a sustainable construction aggregate. Experimental outcomes indicate that the processed CTA exhibits an enhanced specific gravity, diminished water absorption rate, and enhanced mechanical performance. Comparative analyses were conducted on concrete specimens utilizing various compositions: entirely NCA, untreated CTA and treated CTA, with partial substitutions at increments of 20% and 40%. These examinations disclosed that treated CTA showcased an improvement in compressive strength and energy absorption capacity. Consequently, the application of treated CTA addressed the intrinsic limitations of untreated CTA, potentially enhancing the ductility and resilience of the resultant composite material.