Communities in DSpace
Select a community to browse its collections.
Recent Submissions
Item type: Publication , An electrical double-layer supercapacitor based on a biomass-activated charcoal electrode and ionic liquid with excellent charge-discharge cycle stability(National Science Foundation: Colombo, 2024-10-10) Kumara, G. R. A.; Medagedara, A. D. T.; Gadiarachchi, H. W.; Karunarathne, D. G. B. C.; Tennakone, K.; Rajapakse, R. M. G.; Bandara, T. M. W. J.Supercapacitors that exhibit high power density and safety are emerging as alternative energy storage devices. The construction and performance of a supercapacitor using the ionic liquid, triethylammonium thiocyanate, as the electrolyte and biomass-activated charcoal films as the electrode are described. Enhancements in both energy and power density were observed even for 10,000 charge-discharge cycles. The fabricated supercapacitor with ionic liquid and activated charcoal-based electrodes showed an impressive specific capacitance retention of 142% even after 10,000 cycles at a scan rate of 500 mv s-1, which is attributed to the clearing of ion conducting pathways and enhanced charge transport with increasing temperature. Impedance analysis confirmed the reduction of resistive losses with increasing cycle numbers. The initial energy and power densities of the Electrical double-layer capacitance (EDLC) were 0.926 W h kg-1 and 5681 W kg-1, and they showed 42.2 % and 60.6 % increments after supercapacitors cycles. The study reveals low-cost biomass-based activated carbon electrodes and trimethylamine thiocyanate can be used to prepare supercapacitors with remarkable cycling performances.Item type: Publication , Structural brain network topology in migraine vs. healthy subjects: a graph theory study(National Science Foundation: Colombo, 2024-10-10) Amarasinghe, A. D. I.; Wijewickrama, D. I. H.; De Fonseka, I. S.; Lawanya, M. A. D.; Fernando, W. N. S.; Wishwanthi, D.A.D.; Senanayake, G.; Pushpakumara, S.; Ediri Arachchi, W. M.There is compelling evidence that migraine is associated with a decline in grey matter in the brain. We postulate that these changes might affect the architecture of the structural brain networks and normal wiring leading to altered functioning of the brain. Therefore, our goal was to compare the global brain network topology of patients with migraines and healthy subjects using grey matter structural networks. The study involved 45 patients with migraine and 46 healthy subjects. 3D, T1-weighted brain images were obtained using a 3 Tesla MRI scanner. Images were preprocessed, and grey matter volume images were generated. Group-level structural connectivity matrices were created using Pearson correlation, and the matrices were binarized by applying a series of sparsity thresholds to compute global network topologies. According to the between-group results, patients with migraines showed increases in small-worldness and global efficiency while local efficiency and synchronization did not differ significantly between patients and healthy subjects (p< 0.05). Assortativity values were widely dispersed across different levels of sparsity and were significantly higher in the healthy network compared to the migraine network at sparsities of 0.4 and 0.5 (p< 0.05). Furthermore, as network sparsity increased, there was a noticeable trend towards a hierarchy property among patients. According to our findings, patients with migraines exhibit better integration and poorer segregation of information processing in the human brain. Graph theory-based approach provides valuable information on network topological metrics in migraine.Item type: Item , Changing coastline of southwest Sri Lanka(Colombo : Natural Resources, Energy and Science Authority of Sri Lanka ; v,55p. ; NA Colleciton, 1995) Weerakkody, U.Item type: Item , Medicinal plants (indigenous and exotic) used in Ceylon-part 1 : Acanthaceae - Burseraceae(Colombo : National Science Foundation ; xv,232p. ; NA Colleciton, 2006) Jayaweera, D.M.A; Senarathne, L.K.Item type: Item , A bibliography on accelerated Mahaweli Project :1977-79 :(Colombo : National Science Council ; 45p. ; NA Colleciton, 1982) Wimalasena, W.G.S [Comp.]