http://repo.lib.jfn.ac.lk/ujrr/handle/123456789/5709 2026-04-17T19:17:14Z http://repo.lib.jfn.ac.lk/ujrr/handle/123456789/1540 Title: Socio-economic status of fishers in Allaipiddy village, Jaffna Authors: Ragavan, N.; Sivashanthini, K.; Sutharshiny, S. Abstract: The present study was carried out in Allaipiddy for a period of eight months from June 2014 to January 2015. The socio-economic data of randomly selected 53 fishermen was ob tained through pre-tested structured questionnaire, in-depth guided interview and observation. Descriptive analysis of the direct social demography was done by using SPSS. All fishermen are Catholics and Sri Lankan Tamils. The sex demography of the community explicit that male is higher in percentage (54.4 %). In the fisherfolk, families with five members are higher in percentage (33 %) and most of them are nuclear families (95 %). Majority of the active fishermen fall in the 36 – 45 age-group. All the fishermen are having primary education and only 21 % of them are teetotalers. The existing fishing methods are underwater-Sirahuvalai (46 %), Seer-net fishing (21 %), Driftnet fishing (13 %), Crab-net fishing (11 %) and Arakodiyan-net fishing (9 %). Majority of fishers (90 %) are earning Rs. 20,000 to Rs. 40,000 per month, while 6 % of them earn as high as Rs. 40,000 to Rs. 60, 000. The economic analysis of the Allaipiddy fisherfolk reveals that high income earning fishermen are involved in underwater-Sirahuvalai. 2015-01-01T00:00:00Z http://repo.lib.jfn.ac.lk/ujrr/handle/123456789/1539 Title: Presence of Saprolegnia spp. (Oomycetes) in the Sivanamman Pond and its Characteristic Features Authors: Digamadulla, K. M. D. S.; Sivashanthini, K.; Thavaranjit, A. C. Abstract: Simultaneous improvisation in expertise and facilities in disease diagnosis have led to the identification of several previously unknown pathogens and diseased conditions. Saprolegniosis is one of the disease for which no known remedies were discovered yet. The current research was intended to study the presence and characterization of Saprolegnia spp. The study results hoped to be beneficial to many aspects of aquaculture and research on Saprolegniosis. Water sample was collected from Sivanamman pond (9°40'50.9N" and 80°01'43.6"E). Saprolegnia spp. was isolated by baiting method under in vitro condition. Identification and characterization was carried out on cultural, vegetative and sexual characteristics featured by Saprolegnia spp. under microscopic observation. Isolate was identified as an aquatic fungus belongs to Saprolegnia spp. with respect to the sporulation from zoosporangium and sexual reproductive structures. The sexual morphologies were significant after a starvation (26 days) in the PDA. Eucarpic mycelium was transparent, vacuolated cytoplasm contained several nuclei and produced differential oogonium with oospores. The results of present study reveal the occurrence of Saprolegnia spp. in Jaffna urban ponds and evidently prove that the mold is administrable in PDA medium. 2015-01-01T00:00:00Z http://repo.lib.jfn.ac.lk/ujrr/handle/123456789/1538 Title: Assessment on the present status of coastal fisheries at Gurunagar, Jaffna Authors: Thivviyan, S.; Jayakody, D.S. Abstract: Fishery is a major income source of the Sri Lankan people resides in the coastal region. Among those, Jaffna contributes a considerable proportion to the total fishery production of the island which was 4.5% of the total fish production in Sri Lanka in 2013. This study aimed to collect recent updated fisheries information as the government already identified Gurunagar as a potential site in Jaffna to develop to the status of a harbor. Fishery related data was collected during the period April to June 2015 from commercial fishing vessels and sirakuvalai fishing operations landed at Gurunagar. Primary data was collected through direct observations during the field visits and secondary information was collected from the records of the Fisheries office at Jaffna. Catch, effort species composition, fishing craft and gear information were collected from randomly selected fishing crafts on randomly selected days. Fishers at Gurunagar engage in different fishing practices. Fishing activities of this area are regulated by the Fisher’s societies with the assistance of Department of Fisheries and Aquatic Resources. A total number of 28 species, representing 22 families were identified in commercial landings during the study period and also the species diversity and size of the fish (2.4 cm - 69 cm) varied with gear types. The types of gears used varied with the craft types. The catch rates of Outboard Fiber Reinforced Plastic Boats (OFRP - one day boats) recorded as higher than in-board day boats. Total fish production was recorded as around 128 tons during the study period. Production of sirakuvalai was accounted for 7.4 % of the total production in the study area. Commercial production per day is recorded around 3972.5 kg/Day and the average number of boats actively operated is 150. The existing facilities in the Gurunagar landing site for anchoring boats, sorting the catches, auctioning, storing and distribution are not up to the level required for an export oriented fish landings. Results of the present study suggest the need of further monitoring of this landing site to gather reliable information at least one year of time to cover seasonal variations of fish landings. 2015-01-01T00:00:00Z http://repo.lib.jfn.ac.lk/ujrr/handle/123456789/1537 Title: Stress induced changes in hydrogen pressure in contact with tubular diffusion membrane Authors: Kandasamy, K. Abstract: Hydrogen permeation studies in Palladium and Palladium alloys reveal that hydrogen diffusion is non-Fickian in metals and their alloys due to the stress field induced by the hydrogen in their lattice. Previously the non-Fickian, uphill diffusion of hydrogen in Pd81Pt19 alloy membrane was explained by attributing it to the modification in the space-time variation of the concentration of dissolved hydrogen in the metal lattice due to Diffusion-Elastic effect. This paper reports evidence for the combined effect on the space-time variation of the concentration of dissolved hydrogen in the lattice by the Gorsky effect and the Diffusion-Elastic effect when hydrogen diffusion initiated in the diffusion membrane either by suddenly increasing or reducing the hydrogen pressure at one wall of the membrane. 2015-01-01T00:00:00Z