http://dr.lib.sjp.ac.lk/handle/123456789/10365 Wed, 07 Jan 2026 06:16:30 GMT 2026-01-07T06:16:30Z http://dr.lib.sjp.ac.lk/handle/123456789/10408 Antioxidant Activity and Nutritional Properties of Freshly Tapped Palmyra (Borassus flabellifer) Sap Sivaji, M.; Aheeshan, B. This study aims to analyze the antioxidant activity and the nutritional profile of the freshly tapped palmyra sap. Samples were collected in pre-sterile sample collection bottles from different parts of Jaffna peninsula and immediately transferred into an ice box. Pooled samples were centrifuged (1000rpm, 5 minutes) and the supernatant is stored at the refrigerator (4℃) for nutritional, and antioxidant analysis. The results exhibit that fresh sap consists of Na (15.3±0.14 mg/100g) and K (22.6±0.12 mg/100g), while the total ash content was 0.62±0.45 (g/100g). The total sugar content of the sap was 16.43±0.07(g/100g) and the reducing sugar and non-reducing sugar content were 2.16±0.32 (g/100g), 14.27±0.04 (g/100g) respectively. Sap exhibited a relatively low amount of fat 0.02±0.01 (mg/100g). DPPH scavenging activity with regard to IC 50 value was 1.36±0.35 mg/mL, and the total phenolic content and ascorbic acid content were recorded as 186±12.27(mg GAE/100g), 12.16±0.31 (mg/100g) respectively. It can be concluded that the fresh sap of palmyra is a good source of antioxidant properties and nutritional value Tue, 06 Jul 2021 00:00:00 GMT http://dr.lib.sjp.ac.lk/handle/123456789/10408 2021-07-06T00:00:00Z http://dr.lib.sjp.ac.lk/handle/123456789/10407 Fiber Optic Sensors for Bridge Monitoring. Appuhamillage, G.K.; Jayawardena, A. This paper presents the data obtained from monitoring a steel Struss bridge using Fiber Bragg Grating (FBG) sensors before and after a proposed repair for crack propagation in the end plates. This paper details the operating mechanism behind the FBG sensors and the advantages of using FBG sensors over resistive foil strain gauges for bridge structural health monitoring and also details how cracks on the outer web’s end plate originated and then provides a step-by-step guide to the completed repair. This technology can be used in other practical applications where structural health monitoring is needed. Tue, 06 Jul 2021 00:00:00 GMT http://dr.lib.sjp.ac.lk/handle/123456789/10407 2021-07-06T00:00:00Z http://dr.lib.sjp.ac.lk/handle/123456789/10406 Effect of Different Process Parameters on the formation of Silver Nanoparticles using Crude and Modified Neem (Azadirachta indica) Leaf Extracts Vivehananthan, K.; Weligodage, H. In recent times, the biosynthesis of nanoparticles, which has led to significant growth in the field of nanotechnology. The use of plant extracts has become an impetus in this field as it is a simple and eco-friendly method. This study was an attempt to study different parameters in biosynthesis of silver nanoparticles using Azadirachta indica (Neem) leaf extracts. Four different process parameters such as concentrations of neem leaf extract, types of neem leaf extract, mixing ratios and the reaction time period were investigated on the formation of silver nanoparticles. Initially, the formation of silver nanoparticles was detected by the visual observation. Then, the synthesized silver nanoparticles were characterized using UV-Visible spectroscopy and scanning electron microscopy (SEM). The change of color from yellow to reddish brown color confirmed the formation of silver nanoparticles. The silver surface plasmon resonance (SPR) band obtained in the expected visible range of UV-Visible spectroscopy confirmed the synthesis of the nanoparticles. SEM images showed that silver nanoparticles are roughly spherical and of uniform particle size, and the average particle size is 100 nm. Further, the maximum absorbance of SPR band was considerably varied with different process parameters used in the present study. The UV-Visible spectra of 2.5 g/100 mL of crude neem leaf extract without any dilution showed maximum absorbance in the expected range with the mixing ratio of (Neem and AgNO3) 1:8. However, the maximum absorbance of modified neem leaf extracts (pH 10) resulted lower in value than the crude extracts in the 20 times diluted sample with the mixing ratio of 1:9. Moreover, modified extract with UV radiation exposure increased the absorbance in the expected visible range. It concludes that fine tuning of the bioprocess parameters would enhance nanoparticle synthesis. Tue, 08 Jun 2021 00:00:00 GMT http://dr.lib.sjp.ac.lk/handle/123456789/10406 2021-06-08T00:00:00Z http://dr.lib.sjp.ac.lk/handle/123456789/10405 Extraction and screening of Biofilm producing Bacterial isolated in Short and Long-term Catheters Vivehananthan, K.; Thevashayinath, S.; Abeygunawardena, I. Sat, 17 Jul 2021 00:00:00 GMT http://dr.lib.sjp.ac.lk/handle/123456789/10405 2021-07-17T00:00:00Z