University of Sri Jayewardenepura: Journals & Proceedings
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Screening of In vitro Antidiabetic and Antioxidant Activities of Selected Sri Lankan Medicinal Plants
No full textSri Lanka is renowned for its rich biodiversity of medicinal plants that have been used in traditional medicine to manage diabetes and oxidative stress. Determining the antidiabetic and antioxidant properties of these medicinal plants offers a novel, accessible, affordable and natural alternative to synthetic drugs. This research also highlights utilizing natural resources for human benefit and sustainable resource management. By reducing use of synthetic drugs, we can minimize the associated environmental costs, such as pollution from manufacturing processes and disposal of pharmaceutical waste. The study investigated the antidiabetic and antioxidant properties of five Sri Lankan medicinal plants: young leaves of Jack (Artocarpus heterophyllus Lam.), Little King Bitter (Andrographis paniculata (Burm.f.) Nees), Ivy gourd (Coccinia grandis (L.) Voigt), Cluster fig (Ficus racemosa L.) and flowers of Aloe vera (Aloe barbadensis Mill.). Total phenolic content and flavonoid content were determined using standard TPC and TFC assays, respectively. Antioxidant activity was assessed by DPPH and FRAP assays, while alpha-amylase and alpha-glucosidase inhibition assays evaluated the antidiabetic potential. Jack young leaves exhibited the highest TPC (54.225±0.754 mg GAE/g) and TFC (18.3402±0.1384mg QE/g), suggesting strong antioxidant potential. Cluster fig displayed the highest FRAP value (23.836±1.133 mg TE/g). Jack and Ivy gourd extracts underwent further analysis. Jack young leaves showed a lower IC50 value (236.636±0.44 ppm) in the DPPH assay compared to Ivy gourd (337.649±1.456 ppm), indicating superior free radical scavenging activity. Conversely, Ivy gourd leaves displayed the strongest alpha-amylase inhibition (IC50=9.145±0.0485 ppm), while Jackfruit leaves exhibited the strongest alpha-glucosidase inhibition (IC50=1.49367±0.00379 ppm). These findings suggest all five plants treated in this study possess varying antidiabetic and antioxidant properties. Jackfruit leaves emerged as particularly promising, demonstrating the most potent free radical scavenging activity and glucosidase inhibition. Further research is needed to explore the mechanisms underlying and validate their potential use for diabetes and oxidative stress management.
Keywords: Natural, Diabetic, Herbal, Inhibition, Pharmaceutica
Analysis of Heavy Metal Accumulation by Soil and Vegetation of Wetlands in Colombo Area
No full textWetlands are an indispensable component in ecosystems. The health of the wetlands is portrayed by the health of plants and soil in the wetland. Pollution of wetlands is a huge problem because the pollutants usually contain a high concentration of heavy metals and other hazardous chemicals. Wetlands can be polluted directly or indirectly via the water bodies that wetlands are interconnected with. Furthermore, wetlands act as sponges and harbor heavy metals within the wetlands. The purpose of the present study was to analyze the accumulation of heavy metals in soil and terrestrial plant species at the wetlands in the Colombo area: Kotte, Madinnagoda, Heen Ela, Diyasaru Park, and Gothatuwa. The content of 10 heavy metals (Cr, As, Cd, Ni, Pb, Cu, Zn, 57Fe, 56Fe, and Mn) in soil and abundant terrestrial plant species in 15 locations of five different vegetation types of wetlands were analyzed. Moreover, the linkage between the above five wetlands was also determined. There are five types of vegetation considered in the above wetlands: herb-dominated low vegetation, herb-dominated high vegetation, Annona woodlands, mixed woodlands, and highland vegetation (Strategy, 2015) associated with wetlands. Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) was utilized to determine the heavy metal contents in each sample. Data analysis was done using SPSS software (IBM SPSS statistics version 21) and Minitab 16 for windows. Microsoft Excel 2010 was used for graphical representation of data. Results indicated that the plant, Syzygium caryophyllatum, had a higher ability to accumulate heavy metals than the other plant species studied. Relatively, the more contaminated areas were Madinnagoda, Heen Ela and Kotte and the less contaminated area was Diyasaru Park. Moreover, Fe accumulation was higher than the others and Cd accumulation was lower than the others in all the wetlands. The present study indicated that the wetlands were slightly polluted by heavy metals with the detected levels of below the maximum permitted levels by WHO. (Chiroma T. M et al., 2014) However, further studies are warranted as environmental pollution is ongoing. The output of the evaluations also insists efforts to conserve the environment, manage agriculture, and shape the environmental policies and regulations.
Keywords: Wetlands, Soil and terrestrial abundant plants, Heavy metals, Garbage dumping, ICP-M
Market Potential and Value Addition Opportunities for Pinus caribaea Products in Sri Lanka: A Stakeholder Analysis
No full textThe current oversupply of Pinus caribaea (Pine) timber in Sri Lanka presents both a challenge and an opportunity for value addition in the timber industry. This study investigated the potential for developing value-added Pine products, addressing common misconceptions about Pinewood properties while identifying viable market opportunities. A comprehensive qualitative survey was conducted using semi-structured interviews with industry stakeholders. Data analysis employed a hybrid approach combining thematic and content analysis methodologies. The investigation encompassed multiple dimensions: current value-added product portfolios, production methodologies, market dynamics, distribution channels, and economic viability. Environmental sustainability and resource utilization were also evaluated to provide a holistic industry assessment. The findings revealed a potential for Pine value addition with a diverse range of existing value-added Pine products in the Sri Lankan market, primarily in the furniture, construction, joinery, assembly, and accessories sectors. However, the study identified several barriers to market expansion, including inherent material limitations, policy constraints, technical challenges, and research gaps. These constraints, while significant, can be addressed through targeted interventions and strategic industry development. Market analysis revealed emerging opportunities for popularizing Pine value-added products in the Sri Lankan timber market, driven by increasing environmental consciousness among consumers seeking durable, cost-effective local products. The export potential for value-added Pine products shows promise, with identified demand in regional markets including Seychelles, Maldives, Mauritius, and India. These findings suggest a viable pathway for transforming Sri Lanka's Pine timber surplus into an economic advantage through strategic value addition. The study provides evidence-based recommendations for developing Sri Lanka's Pine value-addition industry, emphasizing the need for coordinated efforts among stakeholders to overcome identified challenges and capitalize on market opportunities. This research contributes to the broader discourse on sustainable forestry resource utilization and value-chain development in developing economies.
Keywords: Pinus caribaea, Oversupply, Value addition, Market potential, Stakeholder analysi
Evaluating the Financial, Technical, and Sustainability Performance of Fire Briquette Produced from Tea Waste
No full textSri Lanka is a leading tea exporter, contributing significantly to its export income. However, the tea industry faces many challenges such as rising production costs, managing wastes, rising environmental concerns, and rising labor concerns. Under numerous costs of production, the energy costs are a major highlight in the sector. The cost of steam generation using boilers is at the top among all the energy related costs. As a solution, many industries utilize biomass as a cost-effective energy source. But heavy reliance on biomass has raised concerns over long-term sustainability of the biomass supply. Moreover, tea waste resulting from the tea production process poses many challenges with regards to the environmental management in the sector. Therefore, this study evaluates the financial, technical, and sustainability feasibility of producing fire briquettes using tea waste to address the above challenges. The data were gathered from a major tea producer in Sri Lanka's up-country region. The financial feasibility was assessed through primary and secondary data, focusing on initial, operational, and labor costs. Key financial indicators: Benefit-Cost Ratio (BCR), Internal Rate of Return (IRR), and Net Present Value (NPV) were used in the study. Each indicator was calculated for two discount rates (10% and 5%). The computed results of the indicators [BCR (1.17/1.01), IRR (5.07%/0.28%), and NPV (LKR 121,102/LKR 6,224)] were falling short of favorable levels, with a lengthy payback period of nearly five years. From a technical perspective, the calorific value of the tea waste briquette (18.3 MJ/kg) is comparatively similar to the calorific value of other options (wooden briquettes: 16-22 MJ/kg, sugarcane bagasse:17-19 MJ/kg). Hence, tea waste briquettes are technically viable for boiler use. In terms of sustainability, the shift towards tea waste briquettes would reduce dependency on firewood, minimize waste, generate employment opportunities, prevent open dumping, protect natural habitats and re-aligning with environmental objectives. Although tea waste briquettes offer technical and sustainability advantages, financial viability remains a challenge if the facility serves only the organization’s needs. Based on the findings, scaling up production to meet broader organizational or regional demand may improve financial feasibility, but re-assessing the financial, technical, and environmental performance is recommended.
Keywords: Biomass and sustainable energy, Cost-benefit analysis, Fire briquettes, Tea waste, Waste managemen
Health Risks and Environmental Impact Assessment of Reject Water Quality from Reverse Osmosis Plants: A Case Study in Medawachchiya Divisional Secretariat
No full textChronic Kidney Disease of unknown aetiology (CKD-u) has surfaced as a pressing public health challenge in Sri Lanka, particularly within the North Central Province (NCP), where the incidence is highest. Despite extensive research efforts, the precise causes of CKD-u remain elusive, with previous studies indicating that the quality of drinking water may play a significant role in the disease's progression. In response to this public health crisis, both governmental and non-governmental organizations have deployed Reverse Osmosis (RO) water purification systems in regions affected by CKD-u to ensure access to safer drinking water. Medawachchiya, a locality within the NCP, stands out as the area most severely impacted by CKD-u and was the pioneer site for the introduction of RO filtration for drinking purposes. This research, conducted over five years, sought to evaluate the effectiveness of RO systems in removing contaminants from drinking water and to assess potential health risks linked to their consumption. Additionally, the study aimed to analyze the composition and concentration of reject water produced by RO systems to determine its environmental implications and compliance with the Central Environmental Authority (CEA) wastewater discharge standards. A comprehensive social survey was conducted to gather data on prevalent health issues reported by residents across 13 Grama Niladari (GN) divisions in Medawachchiya. Commonly reported symptoms included headaches, migraines, dental issues, gastritis, joint pain, fatigue, stunted growth, and increased thirst and urination. Over the five-year period, measurements of pH, Total Dissolved Solids (TDS), and temperature revealed that TDS levels in RO-filtered water were significantly lower than recommended, while pH values fell into the acidic range. Furthermore, the reject water from the RO process was found to have removed essential minerals and heavy metals, leading to elevated TDS levels in nearby wells associated with the RO facilities. These findings underscore the urgent need for further research to investigate the rising TDS levels and to establish effective regulations governing the operation of RO plants and the management of reject water discharge. The study advocates for the re-mineralization of RO-treated water and the formulation of comprehensive guidelines to mitigate health risks and environmental consequences associated with RO water purification in communities impacted by CKD-u.
Keywords: Reverse osmosis, Chronic kidney disease, Reject water quality, Health risk
Preliminary Assessment on Growth Performance of Sea Cucumber (Holothuria scabra) Integrated with Seaweed (Kappaphus alvarezii) under Pen Culture in Jaffna District
Get PDFAquaculture is one of the essential sectors of global food production, addressing the increasing demand for seafood while alleviating pressure on natural ecosystems. Holothuria scabra, a high-value sea cucumber species naturally occurs in the Northern waters of Sri Lanka and is now being cultured in farms. Kappaphycus alvarezii is a prevalent and quickly expanding seaweed species. Even though new opportunities in the aquaculture sector led many farmers to adopt sea cucumber farming, the lack of suitable sites remains a potential limitation which requires effective techniques to use the available land resources effectively. Therefore, the current study aimed to assess the growth performance of H. scabra integrated with K. alvarezii in pen culture. For this purpose, three different lagoon-based sea cucumber farms were selected in the Jaffna district namely Allaipiddy, Mandaitivu and Passaiyoor. To perform the integration of selected species, the selected sea cucumber farms were divided into two portions: one with seaweed monoline culture, and the other segregated for sea cucumber species only. Then 10 samples of sea cucumber both under segregated and integrated farming and seaweed were selected to measure the fresh weight at a one-week interval. In addition, water quality parameters such as salinity, pH, temperature, and total dissolved solid also were measured at a one-week interval. According to the results, comparatively higher weight gain for sea cucumber was observed under integrated farming due to the contribution of decaying seaweed materials. Specifically, the highest average weight gain of 7.5 g over six weeks of study was recorded in the Mandaitivu area with no significant difference among different study areas. Regarding the growth performance of seaweed, the highest weight gain of 523 g was observed in the Passaiyoor area over six weeks, resulting in an additional income of 7.14% which might have resulted due to more nutrients like nitrate and phosphate added by sea cucumber wastes. Furthermore, the spatial water quality parameters remained the same for all three locations. Overall, it can be concluded that integrated farming of sea cucumber with seaweed, by contributing to the substantial weight gain of sea cucumber and additional profit, hold promise as a sustainable approach in meeting the growing demand for these valuable marine organisms while mitigating the problem associated with limited land area. Further, it is recommended to study the organic matter content in selected study areas to validate the results in future studies.
Keywords: Additional income, Integration, Sustainable approach, Water quality, Weight gai
Microgrid-Based Solutions for Enhancing the Resilience of Power Systems in Agricultural Regions: A Smart Grid Approach for Green Energy
No full textThe potential of smart grid technologies is becoming solutions for the integrity of sustainable energy demand. These concepts will contribute to enhancing the resilience of power systems, particularly in agricultural regions. Despite being highly dependent on reliable power sources, agricultural operations are dealing with challenges such as adverse weather conditions, intermittent renewable energy sources, and interruptions in the grid. This study investigates how smart grid technology combined with microgrid-based systems can improve the sustainability and resilience of power networks in agricultural regions. The objectives include assessing the impact of high renewable energy penetration on grid stability, optimizing energy storage systems for agricultural operations, and implementing demand response techniques to prioritize critical loads. Additionally, the analysis explores methods to address renewable energy intermittency by integrating energy storage systems and implementing strategies to manage the transitions between grid-connected and islanding modes of microgrids. These methods aim to ensure a stable energy supply and reduce disruptions in power distribution during fluctuations in renewable energy generation. The study utilizes MATLAB Simulink to simulate the performance of microgrids under various scenarios, including extreme weather conditions. The simulations are enhanced with a fuzzy logic controller, which facilitates real-time decision-making by dynamically managing changes in energy demand for agricultural operations. This approach enables the evaluation of microgrid resilience in maintaining uninterrupted energy supply for critical agricultural activities while adapting to demand and generation variations. The findings indicate that microgrids can improve the continuation of essential agricultural operations, grid stability, control of renewable energy intermittency and minimize the interruption during the grid disturbances. In order to improve microgrid performance under increasingly unpredictable climate conditions, future implementations will focus on expanding the integration of developing renewable energy technologies and improving adaptive control systems.
Keywords: Demand management, Microgrids, Renewable energy, Resilienc
Catalytic Synergy via Optimized MoS2-WS2 Heterostructure Supported on Nitrogen-Doped Reduced Graphene Oxide for Enhanced Hydrogen Generation in Acidic Medium
No full textTungsten disulfide (WS2) has shown promise as a catalyst for the hydrogen evolution reaction (HER), and doping it with transition metals (e.g., Mo) can further boost its activity. In this study, we synthesized MoS2-WS2 heterostructure supported on nitrogen-doped reduced graphene oxide (N-rGO) using a hydrothermal method, testing MoS2 concentration(w/w) levels at 5%, 10%, and 20% to optimize HER performance. Raman spectroscopy and SEM confirmed the successful formation of MoS2-WS2/N-rGO composites, with Raman spectra revealing four characteristic peaks: 420 cm-1 (A1g mode of WS2), 380 cm⁻¹ (E12g mode of MoS2), and D and G bands of N-rGO at 1,360 cm-1 and 1,600 cm⁻¹, respectively. Additionally, the peak heights of MoS2 and WS2 are influenced by the incorporating concentration of MoS2. SEM images showed a structural shift from irregular flakes to granular and flower-like particles with increased MoS2 concentration, and the presence of MoS2 is responsible for the formation of flower-like particles. Electrochemical HER testing in 0.5 M H2SO4 demonstrated that 10% MoS2-WS2/N-rGO achieved the lowest overpotential (-177.6 mV at -10 mA cm-2) and smallest Tafel slope (73.40 mV dec-1), compared to 5% (-292.3 mV; 101.8 mV dec-1) and 20% (-284.9 mV; 92.9 mV dec-1). The Tafel slope of 10% MoS2-WS2/N-rGO suggests balanced Volmer and Tafel contributions. Double layer capacitance (Cdl) of 5%, 10%, and 20% MoS2-WS2/NrGO, as determined by the CV method, is 2.72, 5.71, and 1.17 mF cm-2, respectively. The corresponding electrochemical active surface areas (ECSAs) measured are 136, 285.5, and 58.5 cm2. This indicates that a 10% (w/w) concentration of MoS2 provides optimal active surface area, highlighting its superior HER performance in acidic media.
Keywords: Hydrogen evolution reaction, Water splitting, MoS2 doping, WS2, Electrocatalys
Attempts in Estimating Mangrove Forest Biomass
No full textThe biomass of a plant is the weight of its total organic matter content dried to a constant moisture, usually expressed in kilograms or metric tons. This consists of both Above Ground Biomass (AGB) which includes leaf, branch and steam, and Below Ground Biomass (BGB) which includes roots. Compared to the AGB, BGB is difficult to quantify. The biomass of a living tree consists of 50% water, 25% carbon and the remaining 25% is made up from other elements such as Phosphorus (P), Nitrogen (N), Potassium (K), Calcium (Ca) and Magnesium (Mg). Mangroves are among the most Carbon-rich forests in the tropics with higher productivity and a capacity to sink carbon four times superior to other tropical forests. However, the extent of mangrove forests declined by 30–50% over the past 50 years because of infrastructure development, aquaculture expansion and overexploitation. Meanwhile, the increasing trend of greenhouse gases such as Carbon Dioxide (CO2), Methane (CH4) and Nitrous Oxide (N2O) draws attention to the potential of Carbon storage in mangroves that are stored as part of its biomass. Therefore, it is required to generate information on mangrove forest biomass in relation to controlling the greenhouse gases in the atmosphere. Quantifying biomass in mangroves is usually performed by a ground survey, which provides consistent means of assessing the biomass. There are three primary methodologies of assessing mangrove forest biomass: (i) Remote Sensing (RS) technologies, (ii) destructive harvesting of trees, and (iii) mathematical models. These mathematical models easily estimate AGB via measured biophysical parameters like tree diameter at breast height (DBH) and height (H), or wood density (WD). Destructive harvesting of trees provides the most precise estimates whereas RS technologies require field data to calibrate and validate products. Accurate estimation mangrove biomass and the usage of RS technologies will provide insights to stakeholders on the importance of conserving mangroves and is crucial for commercial exploitation for national level developmental planning, scientific studies on ecosystem productivity, understanding energy and nutrient flows, evaluating the impact of changes in tropical forests to the global carbon cycle and understanding the crucial role of mangroves in combating climate change.
Keywords: Above ground biomass, Remote sensing, Mathematical models, Destructive harvesting, Carbon storag
Assessing the Impact of Land Use Dynamics on Urban Heat Island Effect: A Remote Sensing Analysis of Vavuniya DSD, Sri Lanka (2003-2023)
No full textThe rapid expansion of human activities has caused significant Land Use and Land Cover changes, impacting local climate through Urban Heat Island (UHI) effect. Although many studies have focused on the impact of urban development on the UHI effect, this study addresses the combination effect of urban development, agricultural expansion, forest loss, and soil texture in the heat effect by examining the dynamics of LULC changes. The study explores temporal trends and spatial patterns of LULC changes in Vavuniya DSD and their correlation with Land Surface Temperature (LST). Landsat and MODIS datasets were used to classify LULC and generate LST maps through advanced Remote sensing techniques. The relationship between LST and LULC was analyzed using trend analysis, correlation analysis, analysis of variance (ANOVA), geostatistical analysis, and regression analysis. Key findings reveal significant expansion in built-up areas (0.84 km²/year) and agricultural land (1.96 km²/year), alongside a notable decline in forest cover (-2.865 km²/year). The linear trend model for Mean MODIS LST values (2003-2023) shows a positive trend: Yt =30.285+0.0187t, including an annual LST increase of 0.0187°C. Regression analysis indicates a strong correlation between LST and both NDBI and NDBSI, identifying urbanization, agricultural expansion, and deforestation as key drivers of LST increases. Moran’s I index shows a significant positive spatial autocorrelation in LST for all years (2003, 2008, 2013, 2018, and 2023), indicating a cluster effect of similar LST values. Using the Getis-Ord Gi* method, hot spot, and cold spot analysis identified an increasing trend in high LST cluster points and a decreasing trend in low LST clusters over the study period. The influence of soil texture on LST reveals that soil with higher clay content exhibits higher LST, while sandy soils tend to have lower LST. The findings highlight the importance of sustainable land management practices to mitigate climate change impacts.
Keywords: Climate change, Land Use Land Cover, Land Surface Temperature, Remote sensing, Urban Heat Island effec