Research Papers - School of Natural Sciences
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Publication Embargo Facile synthesis of silver/iron-TiO2 nanoparticles for sterilization of Nodal explants of Dracaena sanderiana Sander ex Mast. cvs ‘Gold’ and ‘Victory’ and growth regulator effects on in vitro growth(OICC Press, 2025-02-08) Seneviratne, K.L; Peiris, S. E.; Peiris, C. N; Shashikala, R. P. A; Jayasinghe, S; Kottegoda, NThis study investigates the application of silver/iron-titanate (Ag/Fe-TiO2) nanoparticles (NPs) as a sterilizing agent for in vitro cultures of Dracaena sanderiana cultivars ‘Gold’ and ‘Victory’. The motivation behind this research is to find an effective sterilization method that does not harm plant growth. The Ag/Fe-TiO2 NPs, activated by visible light, exhibit catalytic properties that eliminate harmful microbes such as Escherichia coli, Staphylococcus aureus, and Fusarium spp. The main findings indicate that the combination of Benzyl Amino Purine (BAP) at 1.5 mg/L and Indole Acetic Acid (IAA) at 0.01 mg/L significantly enhances shoot number and length in both cultivars. The use of 200 mg/L Ag/Fe-TiO2 NPs achieved 90% contamination-free cultures in the first cycle, with a slight decrease to 80% in the second cycle and 70% in the third cycle. Importantly, the treatment not only sterilizes but also promotes plant growth, suggesting that Ag/Fe-TiO2 NPs could be a sustainable solution for in vitro plant mass production. © 2025 The Author(s)Publication Embargo Visible Light Active Silver Decorated Iron Titanate/Titanium Dioxide Nanohybrid for Sterilization of Explants Grown by In Vitro Technique(John Wiley and Sons, 2022-12-04) Seneviratne, K .L; Munaweera, I; Peiris, S. E; Kodithuwakku, P; Peiris, C. N; Kottegoda, NVisible light (VL) active silver decorated iron titanate/titanium dioxide (Ag-FeTiO3/TiO2) nanohybrids derived from natural ilmenite sand effectively cleanse the exophytic plant pathogens in explants grown by in vitro techniques. VL active nanohybrid is synthesized by acid-hydrolysis of natural ilmenite, followed by precipitation of the lixivium and decoration with Ag onto FeTiO3/TiO2 nanoparticles, and finally calcination under a nitrogen environment to obtain Ag-FeTiO3/TiO2. A morphological study conducted using transmission electron microscopy (TEM) confirms the formation of Ag-FeTiO3/TiO2. Powder X-ray diffraction (PXRD) analysis shows that the nanohybrid primarily consists of anatase, iron titanate (FeTiO3), Ag2O, and Ag. X-ray photoelectron spectroscopy (XPS) study suggests the presence of Ag0/Ag2O/Fe2O3 composites on the FeTiO3/TiO2 particle surface. The optical band gap significantly changes from 3.14 eV (ilmenite) to 2.80 eV after the decoration of FeTiO3/TiO2 with Ag. This nanohybrid is utilized as a surface-sterilizing agent for in vitro establishment of the Dracaena sanderiana Sander ex Mast plant. Findings illustrate Ag-FeTiO3/TiO2 nanohybrid-based photo-sterilization leads to the survival of 90% of the microbes’ free cultures while the material can be re-used due to its photocatalytic behavior. Thus, the newly synthesized nanohybrid can replace harmful sterilization agents used in tissue culture techniquesPublication Open Access THE USE OF BLOOM’S TAXONOMY TO ASSESS STUDENTS’ PERFORMANCE EFFECTIVELY IN WRITTEN EXAMINATIONS(2017) Peiris, S; Peiris, C. N; Wickramasinghe, SBloom’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.Publication Open 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. NAdaptation 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.Publication Open 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. CUser 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.Publication Open 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, SExternal 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.Publication Open 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. CThe 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.Publication Open Access Service quality in University of Colombo libraries: an assessment(university of Colombo, 2011) Somaratna, S. D; Peiris, C. NSurvey 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.Publication Open 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, Sare 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 deliveryPublication Open Access SRI LANKA QUALIFICATIONS FRAMEWORK (SLQF) AND SIGNIFICANCE IN HIGHER EDUCATION(Yunnan Publishing Group Corporation and Yunnan People's Publishing House, 2015-04-18) Wickramsinghe, S; Peiris, C. N; Peiris, SThe Sri Lankan Qualifications Framework (SLQF) is a nationally consistent framework for all higher education qualifications offered in Sri Lanka. It recognizes the volume of learning of students and identifies the learning outcomes that are to be achieved by the qualification holders. With the objective of having a uniform system in naming a qualification, the designators and qualifiers of each qualification have been identified in the SLQF. The purposes and characteristics of each qualification as well as the minimum admission requirements are also stated in the SLQF. SLQF integrates the National Vocational Qualifications Framework (NVQF) developed by the Tertiary and Vocational Education Commission and the pathways of lateral mobility between the vocational education sector and higher education sector have also been identified. SLQF helps in the recognition of accredited prior learning in order to facilitate the vertical mobility within the higher education system. Until the development of SLQF there had been no mechanism to evaluate the qualifications offered by higher education institutions in Sri Lanka. In addition, the SLQF will be helpful to the potential employers to know the level of learning and the attributes of a particular qualification holder. SLQF is useful to the higher education institutions, both in the public and private sector in designing their courses as the minimum level of learning effort required for each qualification is indicated by way of the minimum number of credits that should be earned by a qualification holder. Thus, the SLQF will contribute towards strengthening the quality of higher education qualifications offered by the universities and other higher education institutions in Sri Lanka.