MERCon - 2021

Permanent URI for this collectionhttp://192.248.9.226/handle/123/18493

Browse

Recent Submissions

Now showing 1 - 20 of 128
  • Thumbnail Image
    item: Conference-Full-text
  • Thumbnail Image
    item: Conference-Full-text
    Feasibility study on, enablers and barriers for the implementation of lean construction and the applicability of visual management practices through forms of digital communication in the Sri Lankan industry
    (IEEE, 2021-07) Kariyawasam, DT; Siriwardana, CSA; Adhikariwatte, W; Rathnayake, M; Hemachandra, K
    Even though the implementation of lean practices into the construction framework have many advantages, thus far, the use of lean in the Sri Lankan construction industry is seldom and infrequent. Though many success stories exist around the world on implementing Lean Construction (LC), why the concept is untapped in Sri Lankan context require a thorough and in-depth understanding on the Barriers for LC implementation. In this study, a comprehensive analysis is done on identifying and assessing the possible factors that affect the application of LC, and factors to overcome those barriers based on an extensive literature review followed by a statistical analysis of data from a questionnaire survey which targeted professionals in the industry. From the results obtained from the questionnaire a recommendation was made on integrating Visual Management (VM) practices through means of digital communication as a lean tool, and the feasibility of the application was appraised through a questionnaire survey where a favourable result was obtained. The outcome of this study could help companies to overcome barriers and focus their attention and resources on the significant issues, crucial to support the successful implementation of LC and develop a framework to integrate Visual Management practices into digital communication.
  • Thumbnail Image
    item: Conference-Full-text
    Application of nanotechnology and nanomaterials in the construction industry: the case of Sri Lanka
    (IEEE, 2021-07) Safshath, MIM; Waidyasekara, KGAS; Tennakoon, GA; Adhikariwatte, W; Rathnayake, M; Hemachandra, K
    Nanotechnology is one of the evolving modern technologies, increasingly being adopted in the construction industry. Nanomaterials provide numerous advantages over conventional materials such as improvements in quality and sustainability performance and reduction in cost and time for use. Sri Lanka is geographically rich with mineral resources that contain suitable raw materials for producing nanomaterials. Despite this, adoption of nanotechnology in the Sri Lankan construction industry is low. This paper therefore aims to investigate the availability and application of nanotechnology and nanomaterials in the Sri Lankan construction industry. Considering the novelty of the area, a qualitative research approach was adopted for this study. Semi-structured interviews were conducted with experts in the field of nanotechnology to gather the required data and content analysis techniques were used to analyze the qualitative data collected. The study findings reveal that nanomaterials can be produced using locally available mineral resources. However, Sri Lanka is yet to realize the optimum value from its mineral resources that can be used in the production of nanomaterials. Further empirical opinions regarding the feasibility of producing nanomaterials in Sri Lanka are also offered through this research.
  • Thumbnail Image
    item: Conference-Full-text
    A study to investigate the factors affecting construction worker performance
    (IEEE, 2021-07) Anojan, T; Siriwardana, CSA; Adhikariwatte, W; Rathnayake, M; Hemachandra, K
    Worker performance is highly significant in the construction industry since it affects the productivity, safety, and quality level of the project. Construction activities are considered labour-intensive as they heavily rely on human effort. This study aims to evaluate and rate the impact of the factors affecting construction worker performance in the Sri Lankan construction industry. The factors identified through the literature review were categorized into different 11 groups by their nature. The most suitable factors were selected and grouped by using a specific structured approach. Structured questionnaires comprising all the selected factors were used to gather the relevant data from directors, managers, technical officers, engineers, and other professionals. All the gathered data were analysed and were ranked using the Relative Important Index (RII). Improvement strategies were also proposed, and a framework had been developed for improving worker performance. The results of this study will be worthwhile information to improve the performance of the project as part of the research was involved in investigating the interaction relationship of the key factors affecting worker performance to improve the labour productivity in the Sri Lankan construction industry.
  • Thumbnail Image
    item: Conference-Full-text
    Study on effectiveness of capillary barrier in reduction of rainfall infiltration on a 15° slope
    (IEEE, 2021-07) Havisanth, E; Kulathilaka, SAS; Adhikariwatte, W; Rathnayake, M; Hemachandra, K
    Rainfall induced slopes failures are a very critical issue in Sri Lanka. Natural or cut slopes which remain stable during dry season due to prevalence of high matric suction undergo failure because of loss of matric suction and pore water pressure buildup. Capillary barrier cover system is a cost-effective system with natural soils that could minimize infiltration of rainwater. Capillary barriers are unsaturated cover system that functions in response to change in negative pore water pressure. This research on applicability of capillary barrier cover system on local Sri Lankan cut slopes with 15° slope angle was done through experimental studies and numerical verification of results using GeoStudio, 2012 SEEP/W software.
  • Thumbnail Image
    item: Conference-Full-text
    Prediction of compaction characteristics of coal bottom ash
    (IEEE, 2021-07) Suloshini, S; Ranathunga, AS; Kulathilaka, SAS; Gunawardana, WB; Adhikariwatte, W; Rathnayake, M; Hemachandra, K
    Compaction is the process of artificially improving the mechanical properties of soil. However, determination of compaction characteristics in laboratory using Proctor compaction test is time consuming and expensive. Hence, there is a need of correlating compaction characteristics with other physical properties of bottom ash which can be obtained easily. This paper describes an innovative solution to predict the compaction properties of coal bottom ash for the preliminary assessment prior to geotechnical engineering related field applications. The data for required parameters of bottom ash for the model development were collected through a literature survey representing different parts of the world. After stepwise regression analysis, specific gravity and uniformity coefficient were found to be the most significant input parameters to predict the compaction characteristics of bottom ash. These parameters were then used to develop the models to predict maximum dry density and optimum moisture content of bottom ash using multiple regression analysis. The developed models were accurate with a prediction accuracy less than ±3% for both maximum dry density and optimum moisture content models. These empirical models were also presented graphically. According to those predictive curves, maximum dry density increases with increasing uniformity coefficient and specific gravity while optimum moisture content reduced.
  • Thumbnail Image
    item: Conference-Full-text
    Modeling and simulation of micro size ultrasonic characteristics of lead zirconate titanate and polyvinylidene fluoride
    (IEEE, 2021-07) Rajendraseelan, P; Vijayasingam, T; Adikary, U; Adhikariwatte, W; Rathnayake, M; Hemachandra, K
    This study was focused on modeling and simulation of micro size ultrasonic generator and receiver of polyvinylidene fluoride (PVDF) and lead zirconate titanate (PZT) using finite element analysis (FEA). When PZT-5 H was selected as both ultrasonic generator and receiver, the resonance frequency of the generator and receiver were determined as 15 MHz and 13 MHz respectively and the simulation was performed at 13 MHz frequency to generate ultrasonic wave. In addition to that, when PVDF was utilized as the receiver material its resonance frequency was determined as 10 MHz and therefore simulation was performed at 10 MHz. The resonance frequency remains the same (5 MHz) When PVDF was selected as an ultrasonic generator with whatever receiver materials (PVDF and PZT-5H) used. Then the generated ultrasonic wave was directed to hit the ultrasonic receiver to generate electric potential. To compare and validate the induced voltage across the receiver mathematical equation was derived using piezoelectric constitutive equations. When PVDF worked as receiver it generated higher voltage value than PZT-5H. On the other hand, when PZT-5H worked as an ultrasonic generator, it induced higher voltage across the receiver.
  • Thumbnail Image
    item: Conference-Full-text
    Individualization of nanofibrillated cellulose from Sri Lankan rice straw: structural characteristics and thermal properties
    (IEEE, 2021-07) Ratnakumar, A; Samarasekara, AMPB; Amarasinghe, DAS; Karunanayake, L; Adhikariwatte, W; Rathnayake, M; Hemachandra, K
    Rice straw is the agricultural production residue which is considered as an agricultural waste. Though it is utilized in various ways, there is a greater possibility for value addition by disintegrating nanofibrillated cellulose from this commercially underutilized waste material. In this study, nanofibrillated cellulose (NFC) was individualized from locally available rice straw variety Murunkan via chemo-mechanical treatments. Firstly, cellulose fibers were extracted from rice straw via a set of chemical processes. Then using high intensity ultrasonication (HIUS) treatment acquired cellulose fibers were individualized into nanofibrillated cellulose. Structural, morphological and thermal behavior of NFC throughout the chemo-mechanical processes were studied. FTIR analysis confirmed that the chemical composition of nanofibrillated cellulose was mainly cellulose where amorphous natured hemicellulose and lignin were effectively removed during chemical processes. From the set of chemical processes, Murunkan variety yielded around 34 per cent cellulose fibers. Out of these cellulose fibers around 17 per cent NFC was individualized via the HIUS treatment. Microscopy study showed that the diameters of the extracted NFC ranged between 100 to 200 nm. Findings of this study will not only add value to the rice straw but also embrace sustainable transition to a bioeconomy in the country.
  • Thumbnail Image
    item: Conference-Full-text
    Investigation of mechanical properties of rice straw ash-filled natural rubber compounds
    (IEEE, 2021-07) Fernando, ANA; Pabasara, WGA; Gayashini, KY; Liyanage, DN; Adhikariwatte, W; Rathnayake, M; Hemachandra, K
    Rice straw is the one of highest plant-based waste generated in Sri Lanka. Farmers burn rice straw without taking any advantage making substantial air pollution. It is found that rice straw ash contains a significant amount (62%-82%) of silica which is a prominent reinforcing filler material in rubber compounding. The present research work focuses on incorporation of rice straw ash as an alternative filler material in rubber compounding. Up to date, different ratios of rice straw ash has been incorporated with selected rubber compound replacing the silica filler loading and tensile, tear strength, hardness, compression set properties have been investigated. These properties were compared with those of the reference sample prepared according to the same formulation but without adding rice straw ash. The sample containing the same proportion of rice straw ash and silica showed the highest tensile strength compared with that of the control sample. Further, tensile strength of the sample which contained only rice straw ash was also higher than that of the control sample. The rice straw ash has a strong ability to improve the tensile properties of the rubber vulcanizates, while it negatively affects the other mechanical properties such as hardness, tear strength and compression set.
  • Thumbnail Image
    item: Conference-Full-text
    Numerical modeling of drying behavior of Sri Lankan kaolin
    (IEEE, 2021-07) Jayaweera, JMN; Narayana, M; Adikary, SU; Adhikariwatte, W; Rathnayake, M; Hemachandra, K
    Drying process of green ceramic bodies are complicated due to simultaneous and coupled heat and mass transfers. Dimensional variations and mechanical stresses occur within the ceramic body during drying may create defects in the final product if drying conditions are not carefully controlled. In this study, the drying behavior of Sri Lankan Kaolin was investigated. Initially, Kaolin was characterized using wet chemical analysis and X-ray diffraction to investigate structure and composition. Two batches of Kaolin with different particle size distributions were prepared using wet ball mill grinding with average particles size (D50) of 4.07 μm and 3.57 μm respectively. Green ceramic samples were obtained using extrusion process. Samples were dried in oven at 60°C and moisture variation of the green product was measured with time. Critical moisture content of the Sri Lankan Kaolin was 1.50%. Mathematical relationship was formulated to determine drying behavior of Sri Lankan Kaolin. An unsteady three-dimensional (3D) model was developed and simulated in Computational Fluid Dynamics (CFD) framework. Simulation results developed by the model were compared with data obtained by experiments conducted using Sri Lankan Kaolin. The model results were validated and comply with experiments results and R 2 value was 0.9.
  • Thumbnail Image
    item: Conference-Full-text
    Process optimization of microfibrillated cellulose extraction from cotton waste using response surface methodology
    (IEEE, 2021-07) Jayasinghe, JMR; Ratnakumar, A; Samarasekara, AMPB; Amarasinghe, DAS; Adhikariwatte, W; Rathnayake, M; Hemachandra, K
    Cotton is a natural staple fiber that mostly consists of cellulose compared to wood. The major economic value of cotton is in textile industry. Over the recent past years the demand for cotton consumption has increased significantly than its production. In textile manufacturing, cotton is blended with various other synthetic fibers such as polyester, nylon and lycra to obtain the desired properties. Though fabric recycling methods are available for pre-consumer garment waste, the processes are quite complicated in actual practice. In this work Microcrystalline Cellulose (MCC) extracted from cotton fabric waste was converted into Microfibrillated Cellulose (MFC) using acid hydrolysis method. However, the major challenge in using acid hydrolysis method is the low amount of yield. Three experimental factors that includes; acid concentration, hydrolysis time and temperature show the highest effect in yield and quality of MFC. Therefore, this experiment was designed to optimize the effect of these three independent factors on yield (%) and width (nm) of MFC. Response surface methodology was adapted to design the experiment and ANOVA statistical test results were used to determine the significant effect of those listed parameters on acid hydrolysis.
  • Thumbnail Image
    item: Conference-Full-text
    Linear and non linear creep modeling of talc filled peek composite
    (IEEE, 2021-07) Janith, GI; Amarasinghe, DAS; Attygalle, D; Weragoda, VSC; Samarasekara, AMPB; Adhikariwatte, W; Rathnayake, M; Hemachandra, K
    The creep compliance of a viscoelastic material is a crucial material parameter that controls the time dependent creep. Viscoelastic materials and their composites are being widely used in electronic and structural components where strain response of such a material is of great concern. Linear viscoelastic models such as the generalized kelvin Voigt model is widely used to model the linear creep behavior. Poly ether-ether ketone is a semi crystalline polymer and in this study a PEEK composite filled with talcum is being used which also consists of a semi crystalline polymer matrix. Such semi crystalline matrixes are known to bring forth nonlinear viscoelastic properties. In this study we model the linear creep behavior and the stress dependent nonlinearity of the above-mentioned composite.
  • Thumbnail Image
    item: Conference-Full-text
    Lagrange multiplier based solution for optimizing dg sizes in distribution networks
    (IEEE, 2021-07) Anuradha, KBJ; Jayatunga, U; Adhikariwatte, W; Rathnayake, M; Hemachandra, K
    Integration of Distributed Generation (DG) has occupied a great interest in modern power engineering due to its significant merits over the conventional power generation techniques. However, several aspects such as climatic conditions, land and fuel availability, DG location and DG size need to be carefully considered to harness the best results from integrating DG units for power networks. Among them, sizing of DG units has taken a prominent place as it affects the network operation as well as the cost aspect. Optimizing the sizes of prospective DG units that are intended to be integrated for a given network will facilitate in gaining the expected merits such as minimizing active power losses and voltage deviations without causing any stability, protection and power quality issue. The existing methodologies for determining optimal DG sizes are rather sophisticated. This paper presents a robust mathematical solving approach based on Lagrange Multiplier Method (LMM) for determining the optimal DG sizes for minimizing the active power losses and voltage deviations. The problem is formulated and solved as a multi objective function. Validation of the proposed mathematical solution strategy was tested using the IEEE-6 and IEEE-33 standard test bus systems. Results demonstrate the effectiveness of the proposed methodology.
  • Thumbnail Image
    item: Conference-Full-text
    Voltage control of three phase distribution systems with minimum cost
    (IEEE, 2021-07) Manamperi, DI; Dissawa, LH; Arachchige, LNW; Binduhewa, P; Ekanayake, JB; Adhikariwatte, W; Rathnayake, M; Hemachandra, K
    Prevention of voltage rise under minimum cost in distribution networks with high PV penetration is considered in this study. On load tap changing (OLTC) transformer and PV inverters are used as controllable devices. The actual cost minimization of transformer tap change, inverter curtailment and line losses is considered as the objective of the optimization problem. Sequential use of mixed integer second order cone (MISOCP) program is used as the optimization technique. Simulations results demonstrate the capability of voltage regulation under minimum cost. Exactness of the generated solutions are validated after comparison with load flow.
  • Thumbnail Image
    item: Conference-Full-text
    Modeling and sizing of hybrid energy storage system for virtual synchronous generator
    (IEEE, 2021-07) Wijetunge, SV; Gunasekera, S; Gamage, J; Pathirana, CD; Bolonne, S; Adhikariwatte, W; Rathnayake, M; Hemachandra, K
    Renewable energy sources (RESs) play a major role in the modern power system to meet the increasing demand and to reduce environmental effects. But they are unable to perform frequency regulation resulting in higher frequency deviations with higher integration of RESs. To overcome this problem power converters are modified as synchronous generators using proper control mechanisms called as Virtual Synchronous Generators (VSGs). Energy Storage Systems are required to absorb and deliver excess energy. We have used a battery/ultracapacitor hybrid energy storage system (HESS) to achieve this. Power allocation for the two storage units is modeled such that fast-varying power fluctuations are compensated by ultracapacitor (UC) and low frequency power fluctuations are compensated by the battery. This is achieved by emulating the inertia by the ultracapacitor and emulating reheat turbine model, droop control etc. by the battery. Some research produces the modelling details of HESS but not the sizing considering required performance. To fulfil this research gap sizing of the HESS is presented through this research paper. Eventually, the proposed system was implemented and simulated in MATLAB Simulink. Results were analyzed to verify the proposed concept for different cases to prove that it gives outputs similar to conventional synchronous generator.
  • Thumbnail Image
    item: Conference-Full-text
    A mixed integer nonlinear programming model and heuristic solutions for an automated demand response system for large facilities
    (IEEE, 2021-07) Rodrigo, AS; Ranawaka, AM; Abeywickrama, M; Malawara Arachchi, DA; Adhikariwatte, W; Rathnayake, M; Hemachandra, K
    Demand Response is utilized around the globe to alleviate the peak demand economically and to manage reliability-compromising emergencies in power systems. Sri Lanka requires an effective Demand Response system to cater the peak demand more economically than dispatching expensive thermal power plants, while minimizing sub-optimal consumption patterns exhibited by consumers during peak demand periods. Therefore, this paper is focused on the development of an algorithm for an Automated Demand Response system for large facilities, which is customized to suit the requirements of the Sri Lankan power system. Under this system, both the utility organization and the consumers are expected to be mutually benefited. This algorithm consists of three levels: deciding on whether or not to execute an Automated Demand Response event for a particular time interval, determining the optimum facility-level demand reductions, and determining the optimum appliance- level demand reductions. Mixed integer nonlinear programming and a heuristic method are used to solve the optimization problems in this algorithm. Results of this algorithm are analysed using a miniature model of the Automated Demand Response system, consisting of fifteen power plants and five industrial and general-purpose facilities.
  • Thumbnail Image
    item: Conference-Full-text
    Performance analysis of modified elliot function based temperature controller in the heating mode operation of ahu
    (IEEE, 2021-07) Walgama, S; Kumarawadu, S; Pathirana, CD; Adhikariwatte, W; Rathnayake, M; Hemachandra, K
    (HVAC) systems are responsible for the majority of total global energy consumption and this fact has been increasing emphasis on innovative and efficient energy saving concepts for several years. With the dynamic nature of the indoor thermal conditions, optimum controlling of the operation of heat exchanger coils in Air Handling Units (AHU) is particularly required to ensure user comfort and energy efficiency. This can be accomplished by precisely adjusting the valve opening of the primary supply to heat exchangers. PID controllers are being commonly used as the conventional control method while many other control strategies are offering better performance and hence allowing significant energy saving. This paper introduces a novel modified Elliot function based controller which can be applied for regulating supply air temperature by adjusting the valve opening of the heat exchanger coil in AHU and analyses the performance for heating mode operation by comparing with PID, Fuzzy Logic, and Sigmoid function-based controllers. The results illustrate that the proposed controller outperforms conventional PID controllers and offers closer performance to Fuzzy Logic controllers with 20876 times reduced execution time.
  • Thumbnail Image
    item: Conference-Full-text
    Impact of erp implementation on employee performance in hospitality sector: role of management capabilities
    (IEEE, 2021-07) Samarasinghe, D; Suwandaarachchi, M; Illangasinghe, SD; Adhikariwatte, W; Rathnayake, M; Hemachandra, K
    Most hotels either upgrade or implement ERP systems, with an intention to improve the organizational performance. In hospitality industry, guest satisfaction is linked with performance, where employee performance becomes a critical factor in deciding performance. Therefore, it is interesting to study the impact of the Enterprise Resource Planning (ERP) system implementation on employee performance in hospitality sector. The study investigates the influence of ERP system implementation on employee performance. Also, investigates whether management capabilities mediate the relationship between ERP system implementation and employee performance. The research was conducted based on deductive approach. Structured questionnaire was distributed among pre-selected hotels with ERP systems which were installed/upgraded within past two to three years. The finding of the study shows that there is a positive relationship towards employee performance through ERP system implementation. Further, management capabilities supportively mediate the positive relationship between ERP system implementation and employee performance. Findings will provide learnings to the hotels in the hospitality industry to enhance their performance to meet their increasing demand and agile customer preferences.
  • Thumbnail Image
    item: Conference-Full-text
    The readiness of teachers in adopting flipped classrooms and open educational resources in undergraduate blended learning
    (IEEE, 2021-07) Senanayake, SHD; Sandanayake, TC; Adhikariwatte, W; Rathnayake, M; Hemachandra, K
    Nowadays, blended learning is a popular teaching and learning concept in higher education, which enriches with modern technology. The flipped classroom is one of the models where blended learning techniques can be practiced. As an assistant for the online portion of the blended education, Open Educational Resources can be incorporated. This study focuses on analyzing the readiness of university lecturers to adopt flipped classroom techniques and Open Educational Resources in undergraduate blended education. For the data gathering, face-to-face interviews were conducted with the university lecturers. The collected data were analyzed using thematic analysis techniques. The blended learning readiness was identified under blended learning techniques, challenges and student feedback. The willingness to adopt flipped classrooms were analyzed under activity types, challenges, student feedback and assessment. The adoption of Open Educational Resources was examined under techniques, challenges and student feedback. According to the analysis, it was able to identify that some of the lecturers are already using the techniques, and some are not. But the readiness was there with the lecturers to adapt to the environment, although there are challenges. Therefore, it can be said that blended learning techniques can easily be adopted by lecturers in undergraduate teaching and learning.
  • No Thumbnail Available
    item: Conference-Full-text
    A conceptual framework for the identification of barriers in automotive remanufacturing industry in sri lanka
    (IEEE, 2021-07) Kahingala, NM; Gamage, JR; Punchihewa, HKG; Adhikariwatte, W; Rathnayake, M; Hemachandra, K
    Automotive remanufacturing provides a sustainable solution for waste generation in the automotive industry. Although the automotive remanufacturing industry is prominently seen in countries such as the UK, USA and China, it is now expanding to other parts of the world including India, Japan, Malaysia, and Singapore. Being a country having an automotive industry with significant value addition, Sri Lanka also possesses a high potential for remanufacturing. However, evidence of such industries is hardly seen. Therefore, the aim of the presented research was to develop a conceptual framework to identify barriers and propose solutions in the automotive remanufacturing industry in Sri Lanka. In this pursuit, a comprehensive review of the literature was performed. This was followed by informal interviews with people involved in the automotive remanufacturing businesses. The conceptual framework was then developed based on the challenges in each stage of the remanufacturing process against the three levels of interventions: Educational, regulatory body, and prevailing market conditions. It was revealed from the framework that most of the challenges were linked to the prevailing market conditions. Therefore, this paper provides a basis for encouraging the stakeholders to find suitable strategies in addressing the barriers associated with automotive remanufacturing in Sri Lanka.