ASRS 2025 http://ir.lib.seu.ac.lk/handle/123456789/7862 2026-05-04T02:52:16Z 2026-05-04T02:52:16Z http://ir.lib.seu.ac.lk/handle/123456789/7920 2026-04-23T13:24:45Z 2025-10-30T00:00:00Z

Preliminaries

2025-10-30T00:00:00Z Fernando, U. S. D. Zainudeen, U. L. http://ir.lib.seu.ac.lk/handle/123456789/7919 2026-04-23T13:21:06Z 2025-10-30T00:00:00Z

Assessing urban heat island dynamics in the South Eastern region of Sri Lanka using landsat-8/9 and GIS (2019–2025) Fernando, U. S. D.; Zainudeen, U. L. This study examines the spatiotemporal dynamics of the Urban Heat Island (UHI) effect in the Southeastern region of Sri Lanka, from 2019 to 2025, utilizing Landsat-8/9 satellite imagery and ArcGIS Pro analysis. Despite minimal land use changes, results indicate a significant rise in Land Surface Temperature (LST) from 36.31 °C in 2019 to 37.54 °C in 2025, with Urban Heat Island Intensity (UHII) increasing from 0.009172 to 0.01159. Supervised classification revealed a decline in vegetation cover (NDVI from +0.81 to -0.13) and an increase in urban (9% to 16%) and bare land (2% to 15%) areas, correlating with elevated LST and UHII, particularly during dry seasons. Albedo measurements using a lux meter showed low reflectivity (0.055-0.278) for urban surfaces like roads and concrete, enhancing heat retention, while paddy fields (0.07-0.11) contributed to temperature rises under reduced moisture. It indicates Sammanthurai has low albedo surface and it causes to rice temperature of the area. Weather data from 2024 highlighted a peak temperature of 38.7 °C, with a weak positive correlation (slope 0.02) between solar radiation (224.64 W/m²) and temperature, exacerbating UHI effects. Comparative analysis with Kitulgala’s wetter, forested region (207.065 W/m², 24-31 °C) underscores the role of vegetation and climate in mitigating heat. The study, achieving 91% classification accuracy (Kappa 0.88541), emphasizes climatic factors and land management as key drivers of UHI in semi-rural, agrarian landscapes.

2025-10-30T00:00:00Z Rajapaksha, H. T. D. Dissanayake, B. M. Wickramasinghec, W. A. G. K. Pathirana, N. U. K. http://ir.lib.seu.ac.lk/handle/123456789/7918 2026-04-23T13:17:57Z 2025-10-30T00:00:00Z

A custom Python script for automated tracking of locomotor activity in amphibian larvae Rajapaksha, H. T. D.; Dissanayake, B. M.; Wickramasinghec, W. A. G. K.; Pathirana, N. U. K. Automated behavioural tracking tools are increasingly valuable for reducing observer bias, improving reproducibility, and enabling high-throughput data collection in animal behaviour research. Recent developments in open-source and customizable tracking platforms have enhanced accessibility and analytical efficiency across species, while modern programming tools like R and Python enable affordable and precise behavioural quantification, particularly valuable for research in resource-limited settings. Existing commercial and open-source packages provide useful frameworks, yet they are often constrained by limited flexibility, high costs, or inadequate adaptability to species-specific behaviours, particularly in non- model organisms such as amphibian larvae. To address this gap, we developed a custom Python-based tracking script capable of quantifying locomotor activity from standard video recordings The tool automates the detection and tracking of individual larvae, extracting continuous X–Y positional data and generating visual outputs such as trajectory plots and heat maps to represent spatial activity patterns. Output files are produced in Excel- compatible format, allowing seamless integration with statistical workflows. Behavioral trials were conducted to evaluate both short-term repeatability and developmental consistency of locomotor traits in tadpoles, demonstrating the script’s ability to capture fine- scale variation in activity levels over time. Preliminary validation against manual scoring confirmed high accuracy and reliability, highlighting its potential as a robust alternative to observer-based measurements. Importantly, the script’s open and adaptable structure allows researchers to modify tracking parameters according to study needs, extending its applicability beyond amphibians to other small aquatic organisms. This custom tool therefore offers a flexible, low-cost, and reproducible approach for behavioural ecologists and conservation biologists investigating movement and activity in larval stages. By facilitating detailed and standardized quantification of locomotion, it contributes to advancing questions in developmental biology, personality research, and ecological assessments of amphibian populations—areas of growing significance in light of global amphibian declines.

2025-10-30T00:00:00Z Afrija, M. M. F. Zainudeen, U. L. Najitha, A. R. http://ir.lib.seu.ac.lk/handle/123456789/7917 2026-04-23T13:13:40Z 2025-10-30T00:00:00Z

Solid state double-layer capacitor with efficient natural graphite and coconut shell charcoal composite electrodes Afrija, M. M. F.; Zainudeen, U. L.; Najitha, A. R. The growing demand for electronic devices has significantly increased the need for efficient and sustainable power sources. Supercapacitors, including electrochemical double layer capacitors (EDLCs) and pseudocapacitors, have gained more attention due to their high power density, longer lifespan, and energy densities surpassing conventional capacitors. EDLCs are widely used in backup power systems owing to their durability and rapid charge- discharge capabilities. Various carbon-based materials are commonly employed as electrodes in EDLC fabrication. This study focuses on the development of an EDLC utilizing a gel polymer electrolyte (GPE) composed of polyvinylidene fluoride-hexafluoropropylene (PVdF-HFP), ethylene carbonate (EC), propylene carbonate (PC), and zinc acetate [Zn (CH3COO)2]. The GPE was synthesized via solvent casting, while electrodes were fabricated using a composite of coconut shell charcoal powder, natural graphite, and PVdF binder. Optimization of the electrode composition was achieved by varying the ratios of coconut shell charcoal and natural graphite, aiming to maximize specific capacitance. The optimal electrode composition was found to be 10 wt. % PVdF, 40 wt. % of natural graphite, and 50 wt. % of coconut shell charcoal. The optimized EDLC exhibited a highest single electrode specific capacitance of 1.82 μF/g[at the scan rate of 0.1v/s], determined through equivalent circuit analysis using NOVA 1.11 software. Electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and charge-discharge testing were conducted to evaluate the performance of the EDLC, while EIS and DC polarization tests assessed the ionic conductivity of the GPE. The temperature-dependent conductivity variation confirmed that the GPE functions as a purely ionic conductor. This research contributes to the development of sustainable, cost-effective energy storage devices by utilizing natural and renewable carbon materials, supporting advances in eco-friendly supercapacitor technologies.

2025-10-30T00:00:00Z