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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 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 An integrated approach to the management of rice root knot nematode, Meloidogyne graminicolain Sri Lanka(Journal of Science of the University of Kelaniya, Sri Lanka, 2011) Amarasinghe, L.D.This study was carried out to design tools for integrated management of root knot nematode, Meloidogyne graminicola, in rice in Sri Lanka. Rice varieties namely, At5, At353, Bg304, Bg305, Bg359, Bg450, Bg94-1, Bg379-2, Ld355 and Ld356 were tested for their reactions against M. graminicola. Effect of poultry manure, cow-dung and paddy husk with or without cinnamon-leaf oil in reducing M. graminicola was studied. It was revealed that rice varieties At5, At353, Bg304, Bg305, Bg450, Bg379-2, and Ld356 were tolerant to M. graminicola as compared to Bg94-1 which is highly susceptible with high rate of reproduction. Plants treated with poultry manure had significantly low nematode population. Plants grown in poultry manure enriched soil had lower yellow and dead leaves as compared to other plants. Addition of cinnamon-leaf oil improved the nematode control. This study concludes that rice varieties namely At353, Ld356, Bg304, At5, Bg305, Bg450 and Bg379-2 can be used for fields that are prone to M. graminicola infestation while poultry manure can be utilized at least occasionally as a nematicide cum fertilizer to reduce nematode infestation level in rice plants and to improve soil fertility.Item Applied magnetic field and stress induced anisotropy dependence of energy for oriented ferromagnetic thick films(University of Kelaniya, 2008) Samarasekara, P.The energy of perfectly oriented thick ferromagnetic films at different applied magnetic field and stress was studied using classical model of Heisenberg Hamiltonian. For the values of parameters used in this report, the energy required to orient the film with 1000 layers in 41.4° or 57.6° directions becomes minimum at applied magnetic fields of ω Hout = 4.8 or ω Hin = 4.8, respectively. The film can be easily oriented in 172° direction by applying the external stress ω Ks = 3.6 perpendicular to the film plane, for the values of parameters used in this report. These final results mainly depend on the values of other parameters used for calculations. The energy becomes minimum and maximum at almost the same values of oriented angle (θ), in plane magnetic field, out of plane magnetic field and stress for both sc(001) and bcc(001 lattice types. But the values of energies corresponding to maxima and minima are slightly different for the sc(001) and bcc(001) lattices.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 Assessment of the future management education needs foe industrial development in Sri Lanka(University of Kelaniya, 1992) Goonatilake, L.Item Automatic Segmentation Of Given Set Of Sinhala Text Into Syllables For Speech Synthesis(University of Kelaniya, 2007) Kumara, K.H.; Dias, N.G.J.; Sirisena, H.A dictionary based automatic syllabification tool has been given for Speech Synthesis in Sinhala language. This tool is also capable of providing frequency distributions of Vowels, Consonants and Syllables for a given set of Sinhala text. A method of determining syllable boundaries has also been shown. Detection of Syllable boundaries for a given Sinhala sentence is achieved by four main phases and those phases have been described with examples. Rules for the automatic segmentation of words into syllables have been derived based on a dictionary. An algorithm has been produced for the implementation of these rules which utilizes the dictionary together with an accurate mark up of the syllable boundaries.Item Automatic Segmentation of Separately Pronounced Sinhala Words into Syllables(University of Kelaniya, 2011) Priyadarshani, P.G.N.; Dias, N.G.J.Aligned corpora are widely used in various speech applications like automatic speech recognition, speech synthesis, as well as prosodic and phonetic research. The segmentation into syllables can be done manually or automatically. But it consumes significantly more time for a fully manual phonetic segmentation and practically it is a complicated task because in many cases it requires a large aligned speech corpus. If the manual syllabification is done by a group of individuals then the consistency is decreased because the analysis variations of the individuals. Consequently, there is a dire need for automatic syllabification and it is important because Sinhala language is syllable centric in nature. A method for syllabification of acoustic signals of separately pronounced Sinhala words has been given. Detecting the syllable boundaries was achieved by two main phases and those phases have been described with examples. Keywords:Item Buddhism discernible in Science(University of Kelaniya, 1992) Ariyarathne, J.K.P.Item The changing quality of life(University of Kelaniya, 1992) Fonseka, C.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 Cobal Ferrite Films as Described by Third Order Perturbed Heisenberg Hamiltonian(University of Kelaniya, 2014) Samarasekara, P.Magnetic properties of thick films of Cobalt ferrite have been investigated using third order perturbed modified Heisenberg Hamiltonian at different values of second and fourth order magnetic anisotropy. Thick films with up to 10,000 layers have been employed for this investigation. The magnetic energy versus number of layers, second and fourth order anisotropy have been plotted in order to find the magnetically easy and hard directions of cobalt ferrite films. Energy has minimum and maximum values at certain values of second and fourth order anisotropy values, indicating that that there are magnetically easy and hard directions. Energy shows the same type of variations with number of layers in the film. For the values considered in this manuscript, the easy direction of magnetization was found to be 1530 with the normal line drawn to the film surface. However, the easy axis direction depends on the values of parameters used in simulation. Determination of easy directions of magnetic films is important in applications of magnetic memory devices.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 Detecting and preventing plagiarism in online assessment(University of Kelaniya, 2008) Wannige, C.T.; Sonnadara, D.U.J.; Usoof, H.A.; Hewagamage, K.P.Assessment is an important area in both teaching and learning. E-assessment is the foremost methodology for assessment in distance learning. This paper presents a method based on client-server architecture that can be used in capturing/preventing plagiarism in online assessments for distance learning centres. Among many possible scenarios of plagiarism, developed system focused on preventing or capturing unauthorised help obtained from online chat forms, websites or other types of communication mediums as well as use of stored text/restricted software. Bench tests show high degree of accuracy in capturing plagiarism scenarios by monitoring the change of grey values observed in edge detected screen shots. During pilot tests, participants attempted activities of plagiarism although the software was designed to prevent the act of plagiarism. The results show 97% accuracy in capturing plagiarism scenarios by the developed software in a restricted Ubuntu Linux environment.Item Determination of Phase Transitions in Y-Shaped, Branched Alkane, C120H241CH(C195H391)C119H23 Using Raman Spectroscopy(University of Kelaniya, 2008) Suranga, P.A.; Wickramarachchi, R.; Spells, S.J.Raman spectroscopy has been used to identify solid – solid phase transitions in the symmetrically branched alkane, C120H241CH(C195H391)C119H239 during real-time heating. The vibrational modes in the region from 1700 to 200 cm-1 were studied. A single phase transition was identified at 87°C ± 5°C in this alkane based on the changes in the band intensities. It was revealed that the crystalline bands show subtle changes whereas the disorder bands show the most significant changes at this transition.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 Development of Suitable Propagation Systems for Tephrosia spp. in Sri Lanka(University of Kelaniya, 2014) Priyadarshan, A.I.S.; Senanayake, S.P.; Jayatilleke, M.P.; Rajapakse, S.Genus Tephrosia (Fabaceae) commonly known as ‘Pila’ in Sri Lanka. Some Tephrosia spp. are used in many traditional therapeutic preparations in Sri Lanka and also in other countries. Increased use of Tephrosia in traditional therapeutic systems has developed a great demand for these species. Thus production of planting materials for commercial cultivation has become a timely requirement. Therefore, this research was conducted to determine suitable propagation systems for four selected Tephrosia spp.; T. purpurea, T. villosa, T. noctiflora and T. pumila. Even though seeds of Tephrosia spp. showed high viability, lower germination percentage was observed on wet filter paper as well as in six different potting media [M0 (Coir: dust: Sand; 1:1:1), M1 (Coir dust: Sand: Top soil; 1:1:1), M2 (Coir dust: Sand: Top soil: Compost; 1:1:1:1), M3 (Coir dust: Sand: Top soil: Compost: Cow dung; 1:1:1:1:1), M4 (Coir dust: Sand: Compost; 1:1:1), M5 (Coir dust: Sand: Top soil: Cow dung; 1:1:1:1)] during a period of one week. Water impermeability of seed coats was identified as the main reason for the seed dormancy in Tephrosia spp. and soaking seeds in Con. H2SO4: H2O; 3:1 for 25 minutes and rubbing seeds on sandpaper for 2 minutes were determined as suitable dormancy breaking methods. Variation was observed in the growth performance of Tephrosia spp. in six different potting media. Growth performances of seedlings of Tephrosia spp. in hydroponic solution and soil medium were observed and soil medium was selected as the most suitable medium for the growth of Tephrosia species based on their growth performances.Item Effect of Cinnamic Acid and Modified Atmosphere Packaging on Storage Life of Pleurotus Ostreatus (Oyster Mushrooms)(University of Kelaniya, 2013) Jayawardena, B.; Silva, H.A.P.In Sri Lanka Oyster mushroom (Pleurotus ostreatus) is a popular cultivated variety of mushrooms. It is considered as a good source of proteins and fiber. The shelf life of Pleurotus ostreatus is short and it deteriorates rapidly due to browning and microbial infestations. Polyphenol oxidae is the enzyme responsible for enzymatic browning. Polyphenol oxidase inhibitors are used to inhibit the browning reaction. Cinnamic acid is an inhibitor of polyphenol oxidase of mushroom. In the current study cinnamic acid treatment and modified atmosphere packaging were used to extend the storage life of Pleurotus ostreatus. The ID50 value of cinnamic acid for polyphenol oxidase of Pleurotus ostreatus was 3.42 mM. Mushrooms were dipped in 0.50 mM, 1.25 mM and 2.00 mM solutions of cinnamic acid and stored in polyethylene bags for 4,7, 11 and 14 days at 4ºC . After the storage period the organoleptic properties were evaluated. After 07 days of storage product started to deteriorate in the controls and some treated samples. Mushrooms treated with a cinnamic acid concentration of 1.25 mM and packed in polyethylene bags and stored at 4º C maintained the organoleptic properties up to 11 days. The storage life of Oyster mushroom can be extended up to 11 days at 4º C using 1.25 mM cinnamic acid dipping and packaging in 150 gauge (38 μm) polyethylene bags with 3:1 surface area to weight ratio.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 Effect of moisture stress at different growth stages of tomato plant (Lycopersicon esculentum Mill.) on yield and quality of fruits(University of Kelaniya, 2010) Vijitha, R.; Mahendran, S.There is a need to utilize the water efficiently and effectively because water availability is scarce in the dry zone of Sri Lanka. An experiment was conducted to determine the changes in fruit quality of tomato cv. KC-1 with moisture stress viz., determine the vitamin C, total soluble solids (TSS) and acid contents of tomato fruits during fruit ripening stage. Also, investigated in the present study was to find out the most critical stage/s of the plant growth to moisture stress in order to sustain the yield by efficient water management. Experiment was conducted at the agronomy farm of the Faculty of Agriculture, Eastern University, Sri Lanka. The experimental design was randomized complete block design with five treatments and four replications. Moisture stress was imposed during vegetative, flowering, early fruiting and fruit ripening stages of tomato for a period of four days in each growth stages. The control plants were watered daily to the field capacity. The stress cycle was single in which water was withheld completely at once. The result showed that moisture stress at fruit ripening stage reduced the vitamin C contents of fruits. The TSS and acid contents of the fruits were slightly affected by moisture stress when the stress was imposed during the fruit ripening stage but they were not significant. Vitamin C, TSS and acid contents of fruits were unaffected by moisture stress given during vegetative, flowering and early fruiting stages. Moisture stress reduced the yield of tomato and the stress during the flowering stage showed the highest yield reduction compared to the other growth stages. Hence, the flowering stage is the most critical stage of growth of tomato to moisture stress for the fruit yield.