Journal of Science
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Item Chemical Specification of Nickel-Glycinate Complexation(Journal of Science of the University of Kelaniya Sri Lanka, 2003) Liyanage, J.A.Analytical techniques which facilitate determination of concentrations of metal ions, solvated protons and hydroxo-complexes or equivalent can be used to study the complexation of metal ions and ligands. Complex speciation measurements using glass electrode potentiometry , which allows a fast, reproducible determination of equilibrium concentrations is an electrometric titration technique used for the determination of formation constants of ligands.The technique does not disturb the labile equilibrium between metal ions, ligands and protons. The computer program ESTA (Equilibrium Simulation for Titration Analysis)is a complex and sophisticated speciation program used to analyse potentiometric titration data and to simulate equilibrium distributions of chemical species. This applies weighted leat squares objective functions to analytical parameters such as titre volume and emf readings. The chemical combination of nickel (Il)-glycinate-proton system has been chosen and activities of component in the equilibrium system were kept constant by working in a medium of high and constant ionic strength of 150 mmol dm-3 sodium chloride inert electrolyte medium, which approximates to that of most biological fluids, in order to express the formation constant in concentration terms. The experimental protonation curve shows that the ligand has two protonation sites and formation and deprotonation curves show that the metal to ligand complexation ratio is up to 1:3. Estimates for the protonation and formation functions obtained were optimized and the refined constants were calculated. Results were further substantiated by the good superimposability of the experimental and simulated curves. The species distribution diagrams confirm that the complexation between nickel (II) and glycinate is up to 1:3.Item Success factors in Information Technology applications in small and medium scale industries - the Sri Lankan experience(Journal of Science of the University of Kelaniya Sri Lanka, 2003) Munasinghe, L.; Jayawardena, D.P.W.This paper argues that the industrialist in developing countries should make use of the opportunities made available by the rapid advancement of information technology to enhance the competitiveness. Most of the enterprises that have made an attempt towards this have not realized the expected benefits of implementing Management Information Systems (MISs). The main reason for this being the lack of understanding of the factors which influences the success of MISs. The main objective of this paper is to identify the factors having a positive influence on success of MISs. The present levels of application for each of the potential areas were assessed.The impact of several factors, which are likely to influence the success of the MISs were analysed. This paper identifies the importance of high commitment of management, efficient manual procedures, high level company wide computer literacy, adequate knowledge of management techniques of the systems analysts and a number of other factors for the success of MISs argues the need for a shift of the policy of IT and management education to strengthen the success factors.Item Arginine Decarboxylase from the pathogenic fungi, Colleotrichum gleosporosides : Purification and Properties(Journal of Science of the University of Kelaniya Sri Lanka, 2003) Weerasooriya, M.K.B.; Handagiripathira, H.M.N.L.; Wijewickrama, G.T.Arginine decarboxylase, a polyamine biosynthetic enzyme, was isolated from a phytopathogenic fungi, Colletotrichum gleosporoides, which causes Anthracnose in wide range of plants in many parts ofthe world. The enzyme was purified 25 fold with 16.7% recovery by elution through Sepharose 4B gel column and DEAE Cellulose ion exchange column. As determined by Sepharose 4B gel chromatography, the native molecular mass of the purified enzyme was ~265kDa. SDS-PAGE of the purified enzyme showed two bands around 65 kDa and ~25 kDa, suggesting that possibly this enzyme could be a hexamer of above two sub units. Optimum pH and temperature for the enzyme was 5.2 and 40�C respectively . Beyond 50�C enzyme activity slowly declined and was almost deactivated by 80�C. Approximate Km of the enzyme for the substrate arginine was 67mM.Item The role of Information Technology trends in planning an Information Technology led development strategy for Sri Lanka(Journal of Science of the University of Kelaniya Sri Lanka, 2003) Munasinghe, L.; Jayawardena, D.P.W.It is important to accurately identify the trends of a technology to formulate realistic policies relevant to it. Number of examples related to IT industry proves that this is no exception to IT. This article discusses the global trends of IT applications in areas like education, acces to information, governance, public services, business & commerce, industry , agriculture, home & leisure and their relevance to Sri Lanka . The potential key impediments and trends with respect to the two main investment opportunities namely the software and IT education & training are also highlighted. Sri Lanka has the potential to take advantage of the emerging trend s in many areas. This paper stresses the need to formulate a national policy on IT that would actively promote its application in as many spheres as possible and eliminate the obstacles stifling their implementation.Item A statistical analysis of the monthly mean maximum air temperature in Colombo, Sri Lanka(Journal of Science of the University of Kelaniya Sri Lanka, 2003) Hewapathirana, T.K.The present study was carried out to fit a mathematical model to describe the variation pattern of monthly mean maximum air temperature in Colombo in order to predict the future values. Monthly mean maximum temperature values for a period of over 35 years were used for the analysis : Time series statistical methods were considered to study the trend and seasonal , cyclic and irregular components. The long term pattern in tlie variation of,monthly mean maximum temperature in Colombo appears to be dominated by a pronounced seasonal effect. The highest seasonal effect was found to be in March . It was found that the temprature of a particular month depends on the lagged temperature values of the two preceding months.Item Harnessing Information Technology for national development: A policy framework for Sri Lanka(Journal of Science of the University of Kelaniya Sri Lanka, 2003) Munasinghe, L.; Jayawardena, D.P.W.Unprecedented advancements in Information Technology have made mankind very much dependant on it for a wide array of activities. IT also has paved a path for developing countries like Sri Lanka to overcome the severe challenges imposed by the globalisation of economic and financial activities. Therefore, the time is opportune for Sri Lanka to embrace IT and harness its capabilities for national development. Sri Lanka possesses the necessary prerequisites like a literate population and a liberalised economy, which would make this a relatively easy task. This paper discusses the measures needed to strengthen the key enabling factors for proliferation of IT including IT manpower and IT literacy, information infrastructure and legislation, measures needed to promote application of IT for activities falling under the major potential areas including education, access to information, governance, public services, business & commerce, industry, agriculture and home & leisure activities. The paper also presents measures to reap the maximum benefits of the two sectors related to IT having the greatest potential for success i.e., software industry and IT education & training. The paper argues the importance of incorporating the measures discussed under the above categories if Sri Lanka is to successfully harness the opportunities made available by IT for its development.Item Roost Selection of the Short-Nosed Fruit Bat, Cynopterus spp. in Sri Lanka(Journal of Science of the University of Kelaniya Sri Lanka, 2003) Digana, P.M.C.B.; Yapa, W.B.; Randeniya, R.V.; Ratnasooriya, W.D.A total of 160 day roosts of short nosed fruit bats (Cynopterus sp.) were examined during a 3 year study in Sri Lanka. Day roosts were found in five species of trees; Talipot palm (Corypha umbraculiferay), Coconut (Cocos nucifera), Banana(Musa sp.), Habarala (Alocasia sp.) and Kitul (Caryota urens). A11 the day roostsfound in this study can be categorized in to three groups, viz, tents, foliage roosts and seed string roosts. Majority (92%) of day roosts were in the form of tents, all of which were found in the talipot palm. Foliage roosts ( 7%) were found in three species of plants (c. nucifera, Musa sp., Alocasia sp.) while two (1%) of the roosts were found in Kitul palm, inside the seed strings. Our observations indicate that the tents are constructed by male bats and serve as the primary roosts of the Cynopterus.Item An evaluation of the performance of undergraduate students at the university examinations in relation to selcetion criteria - a case study in statistics at the University of Kelaniya(Journal of Science of the University of Kelaniya Sri Lanka, 2003) Hewapathirana, T.K.Students are selected to follow Statistics and Computer Science as a subject at the University of Kelaniya on the same criteria used by the University Grants Commission to select students to Science based streams of the Universities. As such 40% of the students are selected on island wide merit on their performance at the G.C.E (Advanced Level) examination , 55% on district basis and 5% from the underprivileged districts. The G.C.E (Advanced Level) aggregate mark or the z-score is high in the first group of students , and is low in the last group of students. The objectives of the present study were to determine whether the students who were selected on merit basis do better in the university examinations than the other students and to determine whether the students selected from underprivileged districts do not perform as good as the other students at the university examinations with respect to Statistics course units. The statistical analyses were performed using one way ANOVA, multiple regressions and simple linear correlations. The results indicated that there is no significant correlation between G.C.E.(Advanced Level) results and the performance at the subsequent university examinations in Statistics course units.The low performance of the students of underprivileged districts at the G.C.E (Advanced Level) examination appears to be due to low facilities for education prevailing in these districts. Given the same facilities and opportunities the students from underprivileged districts perform equally well at the university examinations of Statistics course units as the students who get better results at the G.C.E. (Advanced Level) examination.Item Let science and intuition work together(Journal of Science of the University of Kelaniya Sri Lanka, 2003) Degamboda, S.Docs modern science, which depends totally on inductive and deductive investigation methodologies give us absolute knowledge, or is there another mode of generating knowledge out side these two methodologies? This paper attempts to explain that modern science has inherited the mankind, during its existence of over three hundred years, a body of knowledge, which is not only uncertain and transient, but also is relative. The very nature of the way the universe presents itself to us and human limitations prevent scientists from generating a body of knowledge that is absolute, or at least reliable. This study reveals that in some instances new knowledge have emerged in ways not akin to scientific investigation methodology. This source of knowledge is popularly referred to as intuition, but not much work has been done to ascertain the process and realities of intuitive knowledge. A conceptual model of the brain enables us to visualize it as having right and left halves and that those who are stronger on the right can get intuitive sparks that may become seeds of new knowledge. The paper concludes that scientific explorations could be complemented by intuition,which emanates from the right brain and directed training could develop right brain skills .Item Inflight and Outflight Activity Patterns of Five Species of Cave Dwelling Bats in Sri Lanka(Journal of Science of the University of Kelaniya Sri Lanka, 2005) Yapa, W.B.; Ratnasooriya, W.D.; Costa, H.H.; Rubsamen, R.Wavulgalge, a natural cave situated in Nikapitiya, Koslanda (6?40' - 6?45N': 80?00'-81?05'E), in the eastern region of Sri Lanka is sympatrically inhabited by five species of bats. i.e., four microchiropterans: Rhinolophus rouxii (10000 ? 12000 individuals). Hipposideros lankadiva (1500 - 2000). Hipposideros speoris (200 - 300).Mmiopterus schreibersii (700 - 1000) and one megachiropteran, Rousettus leschenaulti (5000 - 7000). Field studies were carried out from May 1988 to November 1989 in this cave to study the factors influencing the timing of inflight and outflight activity of each bat species. Throughout the study period the outflight commenced ca. 10 minutes before the sunset (light intensity 150-350 lux) and the bats retuned the following morning. ca. 10 minutes before the sun rise (light intensity 100 - 200 lux). The light intensity threshold of different species of bats appeared to be different from one another . During the outflight. R. rouxii and M schrribersii were the first bats to emerge, followed by hipposiderids and the fruit bat, R. leschenaulti. During the inflight in the morning, complete reverse sequence was observed. Results show that the light intensity is the most crucial environmental factor that regulates the time of outward and inward flight activities of the bat species of this cave. In contrast, no relationship was evident between the outward and inward flight activities of the bats and the other environmental factors monitored namely temperature, humidity, rainfall and the velocity of the wind.Item Comparison between ultrasonic acoustic emission (UAE) and hydraulically measured loss of hydroulic conductance in Eucalyptus spp. clone GU210(University of Kelaniya, 2005) Manoharan, P.; Pammenter, N.W.Item Oxygen partial pressure dependence of the coercivity of sputtered Polycrystalline nickel ferrite films(University of Kelaniya, 2005) Samarasekara, P.Item Effect of Method of Extraction on the Quality of Coconut Oil(Journal of Science of the University of Kelaniya Sri Lanka, 2005) Senevirathne, K.N.; Dissanayake, D.M.S.Item Haematological parameters of three species of wild caught microchiropteran bats, Miniopterus schreibersii, Taphozous melanopogon and Hipposideros lankadiva in Sri Lanka(Journal of Science of the University of Kelaniya Sri Lanka, 2005) Ratnasooriya, W.D.; Udagama-Randeniya, P.V.; Yapa, W.B.; Digana, P.M.C.B.; Dharmasiri, M.G.This study,for the first time in South Asia, examines haematological parameters of thre species of wild caught Sri Lankan microchiropteran bats, belonging to three different families having different global zoogeographical distributions; Miniopterus schreibersii (Vespertilionidae: n=12), Taphozous melanopogon (Emballonuridae; n=19) and Hipposideros lankadiva (Hipposiderosidae; n=15). Blood samples were obtained from the median vein and the total white blood cell (WBC) count, red blood cell (RBC) count, packed cell volume (PCV), haemoglobin content(Hb), mean corpuscular volume (MCV) and mean corpuscular haemoglobin content (MCHC) were determined using standard haematological techniques. lnterspecies differences existed in some of the parameters monitored, i.e. PCV, MCV, WBC and RBC counts. % of neutrophils and lymphocytes. On the other hand, a gender discrepancy was recorded for T.melanopgon with respect to neutrophils and lymphocytes, and for M. schreibersii with respect to the total WBC count. The highest WBC count and the lowest PCV and MCV were found in M. schreibersii. T.melanopgon registered the highest percentage of lymphocytes and the lowest percentage of neutrophils, while H. lankadiva possessed the highest MCV. Haematological values were recorded also for a single lactating T.melanopogon.Item Growth characteristics of two selected Eucalyptus clones in relation to physiological responses(University of Kelaniya, 2005) Manoharan, P.; Pammenter, N.W.Item Examination Performance of Undergraduates in Relation to Attendance at Lectures(University of Kelaniya, 2005) Hewapathirana, T.K.Item Serum levels of some biochemical constituents of captive Sri Lankan elephants (Elephas maximus maximus)(University of Kelaniya, 2005) de Alwis, G.K.H.; Wijesekara, R.D.; Vithana, D.; Neththasinghe, N.; Ratnasooriya, W.D.Item Determination of Protonation Constants for 2-Hydroxy-1-(2-Hydroxy-4-Sulpho-1-Naphthylazo)-3-Naphthoic Acid(University of Kelaniya, 2007) Liyanage, J.A.; Janaratne, T.K.Chemical speciation modelling in combination with potentiometric titration method was used to determine the protonation constants for 2-hydroxy-1-(2-hydroxy-4-sulpho-1-naphthylazo)-3-naphthoic acid, the Patton and Reeder’s reagent, at 25° C in three ionic strengths of 0.1 mol dm-3, 0.01 mol dm-3 and 0.001 mol dm-3 NaNO3. Potentiometric titrations were performed and pH, titrant volume, temperature and free and total proton concentrations at each titration point were measured. Constants were determined for three of the four protonated sites and the forth one being a very low value as this site is always in the ionic form and is readily ionized in aqueous solutionsItem Methyl Transferase, a Polyketide Biosynthetic Enzyme from Dreschlera Monoceras: Purification and Properties(University of Kelaniya, 2007) Weerasooriya, M.K.B.; Crosby, J.Methyl transferase, a polyketide biosynthetic enzyme in monocerin biosynthesis was isolated and purified from Dreschlera monoceras. The enzyme was purified to near homogeneity with 11.1% recovery, using ammonium sulphate fractionation followed by ultra filtration, SP Sepharose chromatography and gel filtration chromatography. The molecular mass of the purified enzyme as determined by elution through Superdex TM gel filtration chromatography was found to ~ 165kDa. SDS-PAGE of the purified enzyme showed a single band at ~55kDa indicating that possibly enzyme could be a trimer of 3 subunits. The enzyme showed optimum pH at 7.5-7.7, whereas optimum assay temperature was 35-37°C. Enzyme was stable up to 45°C and above this temperature enzyme activity slowly declined and inactivated around 70°C. Apparent Km of the enzyme was found to be ~ 0.083mM.Item Studies on antioxidant activity of Indian gooseberry fruit and seed(University of Kelaniya, 2007) Nadheesha, M.K.F.; Bamunuarachchi, A.; Edirisinghe, E.M.R.K.B.M.; Weerasinghe, W.M.S.K.Fruits and seeds of Indian Gooseberry (Phylanthus emblica, S. Nelli) were investigated to evaluate their antioxidant activity. Antioxidant activity was evaluated by the estimation of peroxide values (PV) of shark liver oil, treated with fruit and seed extracts incubated at 600 C for a period of nine days. Seed extracts showed higher antioxidant activity than fruit extracts. The ethanol and ethyl acetate extracts of the fruit and all extracts of the seed were found to have higher antioxidant activity than the synthetic antioxidant butylated hydroxy toluene (BHT).