Research Papers - School of Natural Sciences

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Start date: 2010End date: 2019

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    PublicationOpen Access
    Porous carbon materials in biomedical applications
    (2019-11-12) Thambiliyagodage, C. J; Mirihana, S; Gunathilaka, H
    Recent advances in carbon based porous materials in biomedical science and technology have been discussed. Biomedical applications like drug delivery, tissue engineering, biomedicine, gene transfection, photothermal and photo-dynamic theory of porous carbon materials such as mesoporous carbon materials, carbon nanotubes, activated carbon, graphene and fullerenes have been briefed. Finally, future biomedical applications of new porous carbon materials including metal organic frameworks, carbon dots have been introduced in this mini review.
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    PublicationOpen Access
    Eco-friendly porous carbon materials for wastewater treatment
    (Springer, Singapore, 2019-08-07) Thambiliyagodage, C. J; Cooray, V. Y; Perera, I. N; Wijesekera, R. D
    Different porous carbon materials were applied to remove organic compounds and heavy metals from wastewater. Hierarchically, porous nitrogen rich monolithic carbon (HPC) was synthesized through the sol-gel synthesis method and carbonization process. Rice husk (RH), an agricultural waste material followed by carbonization at two different temperatures (RH400 and RH600) was used as the naturally generated porous carbon composite. Activated carbon (AC) was used as the control. According to the FT-IR spectra, different functional groups are present in all adsorbents. Scanning electron microscopic (SEM) images show an irregular shaped, random disordered macropore structure in RH and a robust sponge-like disordered macropore structure with ligaments in HPC. Transmission electron microscopic (TEM) images of these materials show a disordered mesopore network. Adsorption capacities of these porous carbon materials were determined for organic dyes and metal ions. Methylene blue and Methyl orange were used as the model organic compounds and Pb2+, Cu2+, Ni2+, and Cd2+ ions were selected as the metal ions. The experimental data demonstrate that the adsorption capacity of AC for Methyl orange (5.88 mg/g) is much higher than that of the alternatives (RH400–1.97 mg/g, RH600–0.69 mg/g, and HPC – 1.14 mg/g). Adsorption capacity of all the adsorbents for Methylene blue is quite similar. Adsorption capacity of RH400 for Pb2+ is much higher than that of RH600, AC and HPC. RH400 has a greater adsorption for Cu2+ and Ni2+ than the other adsorbents. All adsorbents show a low adsorption capacity for Cd2+. RH400 is a promising adsorbent for wastewater purification.
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    PublicationEmbargo
    Catalytic graphitization in nanocast carbon monoliths by iron, cobalt and nickel nanoparticles
    (Pergamon, 2018-08-01) Thambiliyagodage, C. J; Ulrich, S; Araujo, P. T; Bakker, M. G
    Hierarchically porous carbon monoliths containing metal (Fe, Co, Ni) nanoparticles were synthesized in a one-pot synthesis through a nanocasting technique using silica (SiO2) as the template. The macropore structure of SiO2 has been replicated in nanocast carbon and N2 adsorption analysis shows that the monoliths have high surface area, high mesopore volume, and that micropores are also present. The temperature effect on catalytic graphitization was studied by using x-ray diffraction (XRD), transmission electron microscope (TEM) and Raman spectroscopy. It is observed that iron was capable of producing turbostratic carbon at 500 °C, while turbostratic carbon was produced at temperatures of 700 °C when cobalt and nickel are present. Iron, cobalt, and nickel were found to be good graphitization catalysts with the order of catalytic activity being iron > cobalt > nickel. Raman spectroscopy experiments provide insight into the degree of ordering of the carbon of each sample and are in agreement with the results from the other techniques: with increasing pyrolysis temperature, with and without the presence of metals, ordering of amorphous carbon is confirmed. Detailed analysis of the Raman spectroscopic data showed clear differences between the metal catalyzed and non-catalyzed samples enabling the contributions from the two different mechanisms to be clearly distinguished.
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    PublicationOpen Access
    THE USE OF BLOOM’S TAXONOMY TO ASSESS STUDENTS’ PERFORMANCE EFFECTIVELY IN WRITTEN EXAMINATIONS
    (2017) Peiris, S; Peiris, C. N; Wickramasinghe, S
    Bloom’s Taxonomy is widely used, to bring out thinking ability in students, as an assessment method. In this article we emphasize four types of methods generally used in evaluating the intended learning outcomes in written examinations. How questions should be structured in each level of cognitive domain is discussed with an example in multiple choice questions (MCQ), short answer question (SAQ), structured type questions (STQ) and essay type questions (ETQ). Common biological applications were used as example questions. The questions were developed to show how students’ thinking ability was brought out when questions were structured in line with the levels of cognitive domain in Bloom’s Taxonomy. In conclusion, this paper defines how the application of Bloom’s Taxonomy helps in developing complete answers which come out not from the students’ memory but from applying, analyzing, synthesizing and evaluating.
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    PublicationOpen Access
    GUIDANCE FOR PERFORMING TEACHER SELF-EVALUATION IN ORDER TO ENHANCE THE QUALITY OF TEACHING AT HIGHER EDUCATION INSTITUTIONS IN THE ASIA-PACIFIC REGIONS
    (Asia-Pacific Quality Network, 2017) Jayakodyarachchi, D. K; Jayatilake, H. H; Malalage, B. A; Peiris, C. N
    Adaptation to globalization and diversification in Higher Education opens new horizons and leads to re-engineering of the existing higher education (both teaching and learning) in order to cope with the expanding scope and differences. Consequently, Higher Educational Institutes (HEIs) will need to adopt new theories and practices to dissolve the boundaries of quality in HE. The Internal Quality Assurance subdivitions of HEIs play an important role in these processes and will need to focus on and guide the ‗enhancement‘ of teaching and learning quality. This enhancement could be achieved by a variety of ways with the aim to develop quality in teachers. This is bound to result in the quality of the teaching process. When developing the quality in teachers‘, it is vitally important to have positive perceptions towards the changing needs. Thus, the Teacher Self Evaluation method (TSE) directly helps individuals improve their perceptions in the positive way and thereby achieve most of the characteristics of a quality teacher. Therefore the guidelines of good practices applicable to IQA units/evaluators for effective teacher evaluations/assessments ,the characteristics of a quality teacher, the enhancement of the teaching quality at HEIs in the AsiaPacific regions as well as the issues which disrupt the TSE have become vitally important for the teaching practice.
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    PublicationOpen Access
    A gap analysis to measure service quality of university libraries through user perspectives: a case study at the University of Colombo
    (KDU Library, 2010) Somaratna, H. M. D. S. D; Peiris, C. N; Jayasundara, C. C
    User expectations and perceptions are important measures of service quality in academic libraries and service quality is frequently defined in terms of reducing the gap between user expectations and the service provided. The assessment of service quality through user perspectives provides an important feedback for libraries. The aim of this research was to determine the gap between user desired service expectations and actual service perceptions of the University of Colombo Library System to provide a better service to satisfy their expectations. This study conducted as a user survey covered 614 users of the Colombo University Library system. A modified version of a SERVQUAL model was used to ascertain the views of library users about service level. They were asked to assess the actual service delivered by the library; to establish the importance of the service to them as users; and, to identify to what extent the service met their expectations. The largest service quality gap among all the attributes applied to the Colombo University Library System was “Access to electronic journals”. The author’s fervent hope is that this research would provide insights for further research in this field which in turn would eventually help decision makers to improve service quality in our academic libraries.
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    PublicationOpen Access
    WEB BASED MONITORING AND EVALUATION SYSTEM FOR EXTERNAL QUALITY ASSESSMENTS IN UNIVERSITIES
    (INQAAHE Conference, 9-11 April, 2013-Chinese Taipei, 2013-04-09) Peiris, C. N; Wickramasinghe, S; Peiris, S; Meegama, R; Upeksha, G; Hettiarachchi, S
    External Quality Assessment (EQA) is the major component of QA framework in Sri Lanka. The main function of EQA is to review the standard and quality of the HEIs and its programmes of study and to provide the outcome to stakeholders to observe their expectations. Due to lack of organized mechanism to monitor and evaluate the outcome of the EQA conducted in universities the improvement in quality is not visible. Also the System users are in different geographical locations and therefore, no access to observe the outcome of EQA’s. A web based approach was developed, as a method to achieve the expected outcomes of EQA’s. The system provides user friendly, accurate and up-to date information of EQAs and also it provides a feedback mechanism through online forms/questionnaires. The easy access of information would provide the authorities a basis for decision making to improve higher education sector in Sri Lanka.
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    PublicationOpen Access
    User expectation verses user perception of service quality in University libraries: a case study
    (ICULA 2010, Colombo, 2010) Somaratna, S. D; Peiris, C. N; Jayasundara, C. C
    The library as one of the main service organizations in any University the assessment of service quality through user perspectives is very important. It provides a prompt feedback for libraries to assess and improve their services to users. The aim of this research was to measure the desired service expectations and actual service performance of the users of the University of Colombo Library System. As the initial step, 116 different service quality attributes were identified from previous studies done all around the world. Of these 35 attributes which are most appropriate to the Sri Lankan University Libraries were selected by an expert panel evaluation. The selected attributes were incorporated with the SERVQUAL model and a robust instrument was developed to ascertain the views of library users about service levels. This study was conducted during period of May -June 2008 as a user survey in the University of Colombo library system covering the main library and its two branch libraries, Science Faculty Library and the Medical Faculty Library. A total of 614 questionnaires were received indicating 74% overall response rate. Gap analysis was used to determine the service quality gap between desired service expectations and actual service performance. The most important area expected by users was relevance of information received followed by access to electronic journals and adequate lighting in reading areas. The highest performance area was accuracy of information received followed by feel safe and secure in the library and relevance of information received. Access to online journals showed the largest gap between user expectation and performances. The findings of this study give a good insight to improve user satisfaction providing a better service in identified areas.
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    PublicationOpen Access
    Service quality in University of Colombo libraries: an assessment
    (university of Colombo, 2011) Somaratna, S. D; Peiris, C. N
    Survey of 614 users of the University of Colombo Library system using a modified version of SERVQUAL was carried out to ascertain the views of library users about the service level. They were asked to assess the actual service delivered by the library; to establish the importance of the service to them as users; and, to identify to what extent the service met their expectations. Exploratory factor analysis with Varimax rotation was employed to identify underlying dimensions of service quality of the Library and the best predictor of the overall service quality of the University of Colombo Library was identified by regression analysis. Finds that the service quality of the University of Colombo Library System was represented by seven dimensions and the best predictor of the overall service quality was the dimension referred to as “Collection and Access”. This is the first user survey conducted in University Libraries in Sri Lanka to assess the service quality through user perspectives, discovering service quality factors.
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    PublicationOpen Access
    EXTERNAL QUALITY ASSURANCE AT PROGRAM LEVEL: STANDARDS & PERSPECTIVES
    (APQN AGM and Conference, 7-8 March, 2014-Hanoi, Vietnam, 2014-03-07) Peiris, S; Peiris, C. N; Wickramasinghe, S
    are public/private institutions and responsible for quality and standards • University accountability for quality and standards is a key factor in promoting and safeguarding public confidence • To identify and share good practice in the provision of education • To enable funding judgments to be taken on the basis of the outcomes of reviews • To safeguard the standards of awards and the quality of delivery