ARS - 2014
Permanent URI for this collectionhttp://repository.kln.ac.lk/handle/123456789/172
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Item Psycho-social factors associated with parental stress among parents of children with autism, cerebral palsy and Down syndrome in Sri Lanka(Book of Abstracts, Annual Research Symposium 2014, 2014) Godamunne, P.K.S.; Pathmeswaran, A.; Samankula, D.; Samarasinghe, G.Determining factors associated with parental stress can assist in the development of interventions to improve the well-being of parents of children with developmental disabilities. Though studies in other countries have identified a variety of factors that have an impact on stress experienced by parents of children with cerebral palsy, autism or Down syndrome, no such studies have been done in Sri Lanka.Item Electrochemical deposition of CdS thin films using ammonium thiocynate as the sulfur source(Book of Abstracts, Annual Research Symposium 2014, 2014) Ariyasingha, N.M.; de Silva, D.S.M.; Pathiratne, K.A.S.Use of a complexing agent containing sulfur atoms which can form a charge complex with Cd2+ ions could provide a condition necessary to bring atoms or ions of both the elements Cd and S together in the form of a charge complex to the electrode surface thereby facilitating the formation of CdS on the electrode surface over other materials. In the present study, electrochemical conditions necessary to electrodeposits thin films of CdS using ammonium thiocynate as the complexing agent was studied.Item Electrochemical deposition and characterization of CdTe thin films(Book of Abstracts, Annual Research Symposium 2014, 2014) Kumarasinghe, K.D.M.S.P.K.; Chinthana, H.R.D.; de Silva, D.S.M.; Pathiratne, K.A.S.The semiconductor cadmium telluride (CdTe) has been widely used in applications of photovoltaics, sensors and detectors because of its direct band gap with high atomic number and electron density. With its narrow and direct band gap, stability with high absorption coefficient and other optoelectronic properties, it is the most ideal material for photovoltaic structures. A solar cell made of polycrystalline CdTe thin film is one of the most promising low cost materials for photovoltaic applications. CdTe was grown using different techniques such as physical vapor deposition, chemical vapor deposition, molecular beam epitaxy, close space sublimation, liquid phase deposition and electrodeposition. Electrodeposition has demonstrated numerous advantages due to its simplicity, low cost and scalable manufacturing techniques. CdTe films have been electrodeposited on fluorine doped tin oxide (FTO) coated glass substrates which have sheet resistance less than 20 ?/sq. A conventional three electrode cell was used for the deposition where a high purity graphite rod and saturated calomel electrode (SCE) were presented as the counter electrode and as the reference electrode respectively. Prior to the deposition of semiconductor layers FTO glass substrates were cleaned by a sequence of steps which included wiping out with detergent, ultrasonic washing in detergent solvents and then with deionised water followed by degreasing using acetone, methanol and isopropyl alcohol. CdTe thin films have been prepared by potentiostatic electrodeposition from acidic solution containing CdSO4, CdCl2 and TeO2. The deposition mechanism was investigated by cyclic voltammetry. The thickness of the film can be controlled by the charge passed during the deposition, and it is possible to obtain p-type and n-type materials by changing the deposition potential. Photoelectrochemical (PEC) cell measurements were carried out in order to determine the electric conductivity type of electrodeposited layers.The PEC values were determined for both as deposited and heat treated materials.The electrodeposited thin films were characterized and investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-visible absorption spectroscopy. The CdTe thin films were found to posses a bandgap of (1.44�0.02) eV, which is in a good accordance with those reported in the literature.Item Eletrodeposition of CdS thin films using different sulfur sources for CdS/CdTe solar cells(Book of Abstracts, Annual Research Symposium 2014, 2014) Kumarasinghe, K.D.M.S.P.K.; Chinthana, H.R.D.; de Silva, D.S.M.; Pathiratne, K.A.S.Cadmium Sulphide (CdS) and Cadmium Telluride (CdTe) are two promising photovoltaic materials for thin film solar cells. CdS is a wide band gap n-type semiconductor, which can act as a window layer. The function of CdS is to allow energetic shorter wavelength photons to pass for the incidence at the hetero-interface with minimum absorption loss. The high optical band gap of CdS (~2.42 eV) assists this function. Among the different techniques, electrodeposition is one of the most suitable low cost methods, because the material can be deposited on the desired area of the substrate thus providing a film of reproducible quality. CdS films were prepared by electrodeposition technique from CdCl2 as cadmium precursor and Na2S2O3 or (NH4)2S2O3 as sulfur precursor in aqueous medium. For the electrodeposition of CdS three electrode system was employed using glass/FTO as the working electrode (cathode), saturated calomel electrode as a reference electrode and high purity graphite rod as a counter electrode (anode). Electrochemical deposition method through the influence of the concentration of precursor species, deposition potential, deposition temperature and pH offers excellent control over the properties of thin CdS layers using a potentiostatic approach. The changes in the morphology and properties of the films prepared from different sulfur sources were studied. The CdS layers grown using Na2S2O3 as sulfur precursor show thickness below 100 nm. Voc and Jsc obtained for initial solar cells with CdS films grown using Na2S2O3 as sulfur precursor had higher values compared to that of CdS semiconductor layers grown using (NH4)2S2O3. The photoelectrochemical (PEC) cell measurements were used to identify the electrical conductivity type of the layers and it was found that as grown and heat treated material layers were of n-type for both CdS layers which were grown using different sulfur sources. Upon heat treatment, the material layers show enhanced PEC signal indicating improved optical properties. The optical absorption measurements were carried out in order to evaluate the band gap of the resulting materials. All samples exhibit a band gap value of 2.42 0.08 eV without any noticeable differences as expected. Electrodeposited CdS films were characterized by XRD for determination of bulk structure and SEM for surface analysis.Item Evidence based Unani basic factors that would effective on the management of obesity in this new era(Book of Abstracts, Annual Research Symposium 2014, 2014) Manuha, M.I.; Nageeb, B.M.; Iqbal, N.Z.; Paranagama, P.A.Improper diet habits and lethargy for exercises are mentioned widely for the causes of obesity1. Though the causes were found and many programs have been conducted, the obesity is still a challenging problem all over the world. Therefore, the objectives of this study were to identify causes of obesity in ancient Unani concept through the modern interpretation. The ancient physician Avicenna mentioned in his book ?Canon of Medicine� that functional disorder in the Natural faculty (Quwat e Tabai�yya ) is one of the main causes for the obesity with the above said causes2. According to the Unani or Greek concept the system called ?Natural faculty� which governs digestion, metabolism, nutrition and growth of the body. A functional disorder in the natural faculty may occur due to weakness in the organs of natural faculty or due to emotional disturbances such as anger, sadness, jealousy etc. 2. A systematic search was carried out using many ancient texts including ?Avicenna�s Canon on Medicine�, Unani Materia Medica text and scientific research journal articles located in the PUBMED journals. The review was aimed to collected published data on utilization of herbs to reduce obesity. Articles in 61 journals were cited in the systematic reviews and 58.3% research based on animal studies, 33.3% clinical research found on humans and another 8.3% was on the literary review of the anti-obesity herbs. These researches exhibit that there was a significant reduction of weight found after the herbal treatment on the obese mice or obese human. From this review it was found that 95.8% herbs possess the action of strengthening the Natural faculty or gastro intestinal tract (GIT). Out of this 54.2% of herb or part of a herb used in this research had the action of carminative effect on GIT and 45.8% herb or herb part used here had the actions of carminative and strengthening effect on GIT. Hence it was concluded that according to Unani concept a special attention should be focused to enhance the right functions of the natural faculty by carminatives medicines such as cumin etc. when treating obesity by regulating diet and exercise.Item Attractive effect of volatile extracts of tea stems, Camellia sinensis L.O.Kuntze on Glyptotermes dilatatus Bugnion and Popoff(Book of Abstracts, Annual Research Symposium 2014, 2014) PA Paranagama; PD Senanayake; Keerthi MohottiLow country live wood termite (LCLWT), Glyptotermes dilatatus Bugnion and Popoff is one of the major insect pests of low grown tea. They first colonize in rotted stumps which are formed due to the invasion of wood rot fungi through pruned stems of tea plant, Camellia sinensis L.O.Kuntze and continue their feeding to healthy wood. LCLWT damage is significant owing to its economic crop loss and spread in almost all low grown tea areas. However, concealed habit of the pest limits pest management methods leaving no efficient methods to control this pest at present.Item Usage of printed journals of undergraduates in Faculty of Social Sciences: an analysis based on user statistics of the periodicals section, University of Kelaniya(Book of Abstracts, Annual Research Symposium 2014, 2014) Ranaweera, R.A.A.S.The primary objective of this study was to analyze the usage of printed journals of students attached to the Faculty of Social Sciences, University of Kelaniya.