ICACT 2019
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Item Integrating Technology into Undergraduate Classroom; Studentled Video Production as an Effective Instructional Strategy(4th International Conference on Advances in Computing and Technology (ICACT ‒ 2019), Faculty of Computing and Technology, University of Kelaniya, Sri Lanka, 2019) Rupasinghe, T.P.; Wijesinghe, S.C.In the current world context, successful integration of digital technology and education theory has led to new advents of teaching and learning. Current students, termed as “Digital natives” have grown up in a multi-media simulated world and are highly competent in adopting to new technologies and therefore, it is importance to utilize technology enabled pedagogical approaches to invoke students’ interest and engagement. Further in the current socio-economic context, it is of enormous importance to enhance students’ generic skills such as self-directed learning, critical thinking, problem-solving, collaboration and cooperation in addition to the domain-specific knowledge and skills. Utilizing digital technologies in the tertiary education can be named as a valuable approach to address above challenges. In the past decade, using digital videos in the teaching and learning have become an emerging instructional strategy, mainly being used in the content delivery. However, there is only a limited number of studies that have been conducted focusing on learning through student-produced digital videos. Current study focuses on investigating student-led video production as an effective active learning instructional strategy. Study was conducted as a part of an Engineering Technology degree program and students (N=72) were asked to create videos (10-15 minutes) to educate their peers on given topics in the course content. Then they were given the opportunity to teach their peers using produced videos. Students’ perception on the activity was evaluated using surveys and its’ impact on the learning process was evaluated through an in-class quiz and was compared with previous quizzes. Majority of the students (> 90 %) had agreed that the activity helped them to understand subject matter better and improved their confidence, communication skills, team work skills and technical skills. Further, according to statistical testing it was proved that the average mark (57 %) for the quiz after the activity was higher than previous quiz (39 %) proving that the activity has a direct impact on students learning. In conclusion, it can be stated that student-led video production has a vast impact as an instructional strategy which enhances students’ competence, generic skills as well as the subject knowledge and thereby enhance the quality of tertiary education.Item Study on Virtual Learning Environment System in the Field of Construction Technology - A Sri Lankan Universities Perspective(4th International Conference on Advances in Computing and Technology (ICACT ‒ 2019), Faculty of Computing and Technology, University of Kelaniya, Sri Lanka, 2019) Charanya, R.; Kesavan, M.In order to maintain a good relationship in teaching and learning activities among students and university academic staff, a system called Virtual Learning Environment (VLE) can be used. A VLE system was designed among the students and university academic staff members in the field of Construction Technology in Sri Lankan universities to encourage a positive approach in knowledge achievement and to support active learning within the university. This study was carried out to analyze the factors influencing the VLE system and to explore the relationship between the students and university academic staff members on the VLE system. The factors influencing VLE were identified through the literature review and the interviews which were conducted among the university academic staff and the industry experts. A paper-based questionnaire survey was carried out among the students and university academic staff members who used the above created VLE system in the field of Construction Technology in order to measure the severity of the factors influencing the VLE system. There were 40 nos. of responses from the students and 14 nos. of responses from the university academic staff members received. The respondents were requested to indicate their level of contribution on various factors in the survey questionnaire with a 5-point Likert scale. The Relative Importance Index (RII) was calculated for each factor. The severity of each factor was identified based on its RII value. The factors were ranked based on their severity and Spearman’s rank correlation coefficient was calculated. It was found that there was 48.4% of positive degree of agreement between the students and university academic staff on the factors influencing VLE in the field of Construction Technology. The students stated that time saving, infrastructure, collaborative learning, frequent feedback, sustainability and flexible learning are the most significant factors influencing the VLE system, where the university academic staff members identified that collaborative learning, time saving, frequent feedback and infrastructure are the most significant factors influencing the VLE system in the field of Construction Technology from Sri Lankan universities.Item High Fidelity Simulation in Undergraduate Medical Curricula: Experience of Fourth Year Medical Students at a Sri Lankan Medical Faculty(4th International Conference on Advances in Computing and Technology (ICACT ‒ 2019), Faculty of Computing and Technology, University of Kelaniya, Sri Lanka, 2019) Kodikara, K.G.; Karunaratne, W.C.D.; Chandratilake, M.N.Application of theoretical knowledge to management of critically ill patients is a challenging task faced by medical undergraduates where opportunities to learn clinical skills with regard to management of emergencies are few. High fidelity simulation (HFS) is widely used globally as an adjunct to clinical practice enabling students to learn clinical skills in a safe environment. However, research in the use of HFS in Sri Lanka is minimal. The purpose of this study was to explore the response of medical undergraduates to a high-fidelity simulator (HFS) in the context of management of emergencies. A pilot group of 30 fourth year medical students underwent a high-fidelity simulator session. They completed a self-administered evaluation, which included both open and close ended questions and participated in a focus group discussion post-simulation. Descriptive statistics were employed to analyze the responses to close-ended questions and the responses of the focus group discussion and open-ended questions were analyzed for recurring themes. All participating students responded to the evaluation. Students rated the simulation-based learning experience with high positivity. The self-competency of 29 (96.6%) students had increased following the sessions. The session provided a safe learning environment to all students. 19 (63.3%) students felt it helped put theory into practice while 21 (70.7%) students identified it as good practice for internship. 25 (83.3%) students wished to participate in more sessions. 17 (56.6%) students commented on the realistic nature of the experience. This study confirmed findings of previous studies conducted using HFS among medical undergraduates, confirming that the students highly valued high-fidelity simulation and find the opportunity to apply theoretical knowledge to practice in a safe environment. A high-fidelity simulator is a valuable learning tool in undergraduate medical education.Item Establishing Embodied Carbon Coefficients for Building Materials in Sri Lanka(4th International Conference on Advances in Computing and Technology (ICACT ‒ 2019), Faculty of Computing and Technology, University of Kelaniya, Sri Lanka, 2019) Kumanayake, R.P.Buildings are identified as a major energy user and carbon emitter throughout their lifecycle. Carbon emission associated with energy consumption and chemical processes of material production is termed as ‘embodied carbon’. Material production stage or cradle-to-gate building lifecycle includes processes of raw material extraction, transportation and material production which are responsible for about 2040% of building lifecycle carbon emission. As embodied carbon of building materials highly vary with raw material quality, energy sources and production technologies, development of embodied carbon coefficients in the specific context of a country is necessary. Currently, Sri Lanka lacks such data inventories. This study was aimed at establishing embodied carbon coefficients of commonly used building materials in Sri Lanka. The process is made up of 3 stages; scoping, data collection and calculation. The data were collected through on-site surveys of material production facilities. In determining embodied carbon coefficient of a building material, aggregation decomposition hierarchy method was used. The embodied carbon coefficients obtained in the study were compared with values given in Inventory of Carbon and Energy (ICE) database. As the linkage between material production, energy use and carbon emission is dependent on many country specific factors, differences in values can be observed. A country-specific database ensures reliability and accuracy of building carbon emission studies. The process of establishing material embodied carbon coefficients should be standardized and data should be collected throughout the country so that computed values will represent national averages. This study will lead to future development of an embodied carbon coefficient database in the context of Sri Lanka, which will be useful in assessing embodied carbon of building materials and identifying appropriate strategies for mitigating embodied carbon of Sri Lankan buildings.Item Soil Degradability of Food Wrapping Polythene Films Manufactured from PLA, PBAT and LDPE(4th International Conference on Advances in Computing and Technology (ICACT ‒ 2019), Faculty of Computing and Technology, University of Kelaniya, Sri Lanka, 2019) Abeywickrama, M.S.J.; Yatawara, M.D.M.D.W.M.M.K.Food wrapping polythene films manufactured from different virgin materials have become a major environmental concern at present as these films take much time for the complete degradation in the environment. This study assesses the soil degradability of films manufactured from poly-L-lactic acid (PLLA) (28%) + dimethyl ester (38%) + starch (26%) + auxiliaries (8%) (F001), poly-lactic acid (PLA) (F002), poly butylene adipate terephthalate (PBAT) (F003) and low-density polyethylene (LDPE) (F004) in natural soil. The tensile strength, elongation, moisture and water absorption of manufactured films were analyzed at the beginning of the experiment. Half of the manufactured films was immersed in food waste contaminated water and buried at 10 cm depth in soil. The other half was also buried without processing at the same depth in soil. The study was carried out for four months. Percentage degradability was calculated after 02- and 04-month intervals and by using weight losses as a representative parameter of the degradability. Results revealed the significantly highest tensile strength and elongation from manufactured F004. In addition, manufactured F004 showed the significantly lowest water absorption and moisture content (p < 0.05; ANOVA). Nevertheless, the highest percentage degradability (94%) in soil was observed from F003 followed by F002 contaminated with food waste. Moreover, the results showed a poor degradation (< 1%) of films manufactured from F004. The results further revealed that the films contaminated with foods degraded more than films those haven’t contaminated with foods. Therefore, the present study concludes that food wrapping polythene manufactured from PLA and PBAT showed a significant degradation potential within four months whereas films manufactured from LDPE did not show a remarkable degradation within the same time duration.Item Study of the Effect of Incorporating a Preconditioning Step for the Adsorption of Methylene Blue from Water by Douglas fir Biochar(4th International Conference on Advances in Computing and Technology (ICACT ‒ 2019), Faculty of Computing and Technology, University of Kelaniya, Sri Lanka, 2019) Nawalage, S.; Kaumini, G.; Gunatilake, S.R.Three major kinetic processes governing adsorbate uptake by an adsorbent such as biochar (BC) has been defined as external mass transfer, intraparticle diffusion (IPD) and mass action. In the usual methodology of batch adsorption, where the solution containing the adsorbate is directly introduced to the dry biochar, the entire pore space may not be accessible as the pore interior is not well hydrated. The presented work evaluates the effect of incorporating a preconditioning step where the BC is shaken with a selected organic solvent as a means of hydrating the hydrophobic pore interior. It is followed by its equilibration with de-ionized (DI) water to replace the preconditioning solvent. The process provides a BC with hydrated pores with a ‘sample like’ solvent. Solvents utilized for preconditioning were methanol (MEOH), acetone (ACE), acetonitrile (ACN) and DI followed by equilibration with DI. Sorption characteristics of pre-conditioned BC (PBC) was compared with that of non-preconditioned (NBC). The adsorption process was not significantly influenced by pH variations and the predominant sorption mechanisms were concluded to be π-π electron donor acceptor (EDA) interactions and pore filling. Adsorption capacity showed a stochastic dependence with increasing contact time for the preconditioned biochar in contrast to the NBC. Both PBC and NBC fitted well with the PSO behavior. Sorption capacities for all PBC were lower than NBC which can be attributed to pore blockage. In contrast to NBC, a clear rate determining step was not observed by the intraparticle diffusion model for PBC. Though the Freundlich isotherm model was fitted well by the NBC, the PBC sorption did not fit into the isotherm models studied such as Langmuir, Freundlich, Temkin, Sips and Redlich- Peterson. An enhancement in kinetics for DI PBC was observed at the compromise of ill-fitting isotherm patterns and uptake behavior.Item A Novel Technique to Digest Biochar for Metal Analysis(4th International Conference on Advances in Computing and Technology (ICACT ‒ 2019), Faculty of Computing and Technology, University of Kelaniya, Sri Lanka, 2019) Wathudura, P.D.; Peiris, C.; Navarathna, C.; Kaumal, M.N.; Gunatilake, S.R.Biochar (BC) is a low cost carbonaceous adsorbent material widely used for the removal of toxic metal ions from aqueous systems due to their highly porous nature and presence of various functional groups. Depending on the feedstock used to produce these carbonaceous materials, the trace metal content may vary. Various digestion techniques have been incorporated to analyze the metal content of BC though a proper method has not yet been established. This study was focused on finding a suitable method to totally digest the carbonaceous material and to evaluate the matrix effect. Both open vessel and microwave digestion methods were carried out for BC derived from tea waste, king coconut husk, Douglas fir and steam activated coconut shell biochar (CSBC) using mixtures of 69% nitric acid (NA), fuming nitric acid (FNA), 98% sulfuric acid (SA) and 30% hydrogen peroxide (HP) and their turbidity were measured. Lowest turbidities for open vessel digestions were observed for SA/HP mixture for low-temperature pyrolyzed BC with no external heating (2.04 – 7.90 FNU). Microwave digestions provided satisfactory turbidity levels for NA, NA/SA mixture, FNA and FNA/SA mixture for all types of carbonaceous material (1.58 – 20.97 FNU). The matrix effects were compared using cadmium, copper, lead and zinc using flame atomic absorption spectrophotometry. Digestion mixture containing only fuming nitric acid showed the lowest matrix effect for cadmium (1.2) for CSBC and copper (2.4) for CSBC while the mixture containing only nitric acid shows lowest matrix effect (7.6) for zinc with respect to Douglas fir BC. Recovery study confirmed the suitability of FNA as a suitable digestion mixture incorporated with microwave energy.Item Sorptive Removal of Lead (II) from Aqueous Solution using Value Added Tea-Waste Biochar Produced Under DifferentTemperatures(4th International Conference on Advances in Computing and Technology (ICACT ‒ 2019), Faculty of Computing and Technology, University of Kelaniya, Sri Lanka, 2019) Kavinda, K.D.T.; Peiris, C.; Gunatilake, S.R.The removal of lead from aquatic systems using biochar (BC) derived from tea-waste was evaluated. The customized in-house method of BC production was incorporated slow pyrolysis at 300 ℃ (300BC), 500 ℃ (500BC) and700 ℃ (700BC). The different BC types were subjected to a nitric acid modification and magnetization. Results showed reduced adsorption capacities for nitric modified BC. Batch sorption experiments were conducted to evaluate the effect of pH, equilibrium time, associated kinetic models and the thermodynamic basis of lead uptake. For both Non-Modified Biochar (NBC) and Magnetized Biochar (MBC), an acceptable fit for the pseudo second order kinetic model with regression coefficients greater than 0.998 justified a chemisorption process. The dominant mechanism for 700BC can be considered as pore filling together with π electron sharing between the graphene rings and lead whereas sorption on 300BC was governed by electrostatic interactions. Adsorption isotherms modeled were Langmuir, Freundlich, Sips, Redlich- Peterson and Toth, out of which the results were seen to best fit Langmuir and Sips models. A maximum Langmuir capacity of 57.80 mg/g and 48.61 mg/ for 700NBC and 700MBC were obtained respectively. Positive enthalpies and free energies indicated a nonspontaneous and exothermic sorption. Magnetic modification decreased sorption capacities by 15.86 % but led to the easy removal of biochar after the sorption.Item Comparing Geant4 Simulated and TALYS-1.8 Code Evaluated Cross-Section Data for 4.438 MeV Gamma ray Line of 12C(4th International Conference on Advances in Computing and Technology (ICACT ‒ 2019), Faculty of Computing and Technology, University of Kelaniya, Sri Lanka, 2019) Ramanathan, V.In present, Monte-Carlo transport code plays a major role in developing detectors, particularly the Geant4 Monte-Carlo code due to its versality and flexibility for different applications. Although, the Geant4 has been an invaluable tool for the development of devices, the discrepancies in prompt gamma cross-section data for prominent elements of human body has been reported in the range of proton therapy (50 -250 MeV). Even though, the binary cascade model has been suggested in proton therapy range, the problems with prompt gamma production cross-section have been reported. The aim of this study is to compare Geant4 simulated and TALYS evaluated prompt gamma cross-section data of 4.438 MeV photo peak of 12C to identify the inconsistency in the cross-section data. TALYS is a nuclear reaction study software which can be used to simulate nuclear reactions in the energy range of 1 keV to 200 MeV. The Geant4 model of AFRODITE detector system has been modeled to mimic the iThemba LABS AFRODITE detector system. The Geant4 AFRODITE model was validated using three standard gamma emitting sources (60Co, 137Cs, and 152Eu). The absolute detector efficiency of the Geant4 AFRODITE model also was determined. In the cross-section measurement simulation study, 1012 proton histories were used to collide the carbon and mylar target in the proton energy range of 66 – 125 MeV. The same procedures were performed experimentally using AFRODITE clover detector system. Further, TALYS 1.8 code was used to simulate the proton interaction with carbon target in the range of 5 to 150 MeV. As with the 4.438 MeV cross-section data comparison, there is a significant inconsistency between Geant4 simulated and TALYS simulation and also with experimental data set. To improve the accuracy of Monte-Carlo simulation study, more experimental cross-section data and the evaluation of proper physics models of Geant4 Monte-Carlo transport code in proton therapy range are future need.Item Potential Use of Selected Macrophytes Based Constructed Wetlands for the Treatment of Landfill Leachate(4th International Conference on Advances in Computing and Technology (ICACT ‒ 2019), Faculty of Computing and Technology, University of Kelaniya, Sri Lanka, 2019) Perera, K.R.S.; Yatawara, M.D.M.D.W.M.M.K.Phytoremediation using constructed wetlands (CWs) is widely practiced for the removal of contaminants in landfill leachate. The present study was planned to assess the potential of floating macrophytes (Eichhornia crassipes and Pistia stratiotes) and emergent macrophytes (Typha angustifolia and Chrysopogon zizanioides) in improving the quality of leachate discharged from a Sequencing Batch Reactor (SBR) system located at Dompe sanitary landfill, Gampaha, Sri Lanka. The batch type CWs were arranged to identify the suitable dilution of leachate (as 0%, 25%, 50% and 75%) for the optimum plant growths. Based on the preliminary investigations, the potential of improving leachate quality by (ia) E. crassipes (T501) (ib) T. angustifolia (T502) and C. zizanioides (T503) at 50% dilutions and (ii) T. angustifolia (T04) and C. zizanioides (T05) at 0% dilution were assessed in continuous flow CWs. Water quality parameters including temperature, pH, electrical conductivity, turbidity, BOD, COD, TSS, phosphate, ammonium nitrogen, nitrate, sulphate and color were tested once in five days for 40 days period. Results were subjected to One-way ANOVA followed by Tukey’s pair wise tests in Minitab 14. Two sample t-test at 95% CI was also applied as required. With respect to controls, percentage reductions of measured parameters increased in wetlands having either floating macrophyte, E. crassipes or selected emergent macrophytes. Nevertheless, among the emergent plants, C. zizanioides [(T503) and (T05)] showed the highest performance in improving leachate quality followed by T. angustifolia [(T502) and (T04)]at both dilutions. Although E. crassipes (T501) showed higher percentage reductions of the selected parameters at 50% dilutions, this is not recommended as leachate dilutions are impractical in CWs. P. stratiotes has proven unsuccessful in the present study. Therefore, among the plant species selected, C. zizanioides that performed at 0% dilution could be recommended as the best plant for the remediation of leachate draining from SBR system.