University of Sri Jayewardenepura: Journals & Proceedings
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Extraction and Characterization of Natural Food Colorants from Canistel Fruit (Pouteria campechiana): A Comprehensive Evaluation of Physicochemical Properties
Get PDFA food colorant is a food additive that can be any kind of dye, pigment, or substance applied to foods. As artificial food colorants impart health hazards, this research aims to extract carotenoids from Canistel fruits (Pouteria campechiana) as a natural food colorant substitute for artificial food colorants. Carotenoid extraction was done using the solvent extraction method using a hexane, acetone, and ethanol (70%:15%:15) ratio. The instability of the carotenoid is one of the main drawbacks, and microencapsulation techniques have been used to overcome this. 10% MD, 5% MD + 5% GA mixture, and 10% GA were tested as the wall material treatments in the encapsulation process. Encapsulation with 10% MD showed an 11.91±0.29 g higher yield and higher total carotenoid content after spray drying, while 10% MD retained 45.64±5.3% more carotenoid concentration. The color Chroma meter values in three treatments were observed. When considering b* values, the highest yellowness and overall best color measurements were reported by the 10% MD treatment. The 2, 2-diphenyl-2-picrylhydrazyl (DPPH) assay method was used to find antioxidant activity. The highest antioxidant activity indicated the lowest IC50 value as recorded as 3.57±0.04 mg/mL, 4.38±0.20 mg/mL, and 5.19±0.24 mg/mL from the 10% MD, (5% MD + 5% GA) mixture, and 10% GA, respectively. Results revealed that the spray drying technique auspiciously encapsulated the carotenoids
Design and Simulation of a Carburattor to Run an Otto Engine on Producer Gas
Get PDFThis study presents the design and simulation of a carburetor optimized for internal combustion engines running on producer gas, a renewable fuel derived from biomass. Due to the lower energy density of producer gas compared to conventional fuels, achieving an optimal air-fuel ratio is critical for efficient combustion. Several carburetor models were developed and simulated using ANSYS to assess their mixing performance and ability to maintain the required air-fuel ratio under varying conditions. The simulations highlighted challenges in achieving a homogeneous mixture, with early models exhibiting poor mixing and safety risks, such as the potential for backfire due to inadequate pressure relief mechanisms. To address these issues, successive models incorporated design improvements and optimized nozzle configurations, which significantly enhanced the mixing quality. The final model demonstrated a substantial improvement in the uniformity of the air-fuel mixture, ensuring stable engine operation. These findings underline the importance of precise control over the mixing process in carburetor design for alternative fuels like producer gas. The results provide a foundation for further refinement and practical implementation of this technology, contributing to the development of more sustainable energy solutions
Economic Valuation of Nanoplastics from X-Press Pearl Ship Accident
No full textThe X-Press Pearl ship accident resulted in one of the most devastating environmental catastrophes in the region, marked by extensive release of hazardous chemicals, oil, and a significant discharge of nurdles into the marine ecosystem. Nurdles, which are microplastics, can be weathered into nanoparticles which range in size from 1 to 1000 nm during the photodegradation process. A significant research gap exists in understanding the economic consequences of this plastic pollution, which is vital for designing recovery and preventive strategies. Recent studies have found that nano plastics have a significant impact on the health of fish consumers, but no global economic valuation of nano plastics has been conducted yet. Therefore, this study aims to estimate the damage due to nano plastics generated from the X-Press Pearl ship accident, on public health and to determine how the socio-economic factors impact the Willingness to Pay (WTP). Employing the Contingent Valuation Method (CVM), the study assesses the public's WTP to prevent future incidents similar to the X-Press Pearl ship accident. A household survey was conducted using a pre-tested questionnaire for a sample of 800 households in Western Province through one-to-one interviews. A stratified sample was created based on the population of each district and the double bounded dichotomous choice format was used as the elicitation method. Respondents were asked whether they were willing to pay a specific amount towards the scenario proposed and depending on their answer, a follow-up question was asked. It includes a lower bid if the answer given to the first question was negative, and higher otherwise. Annual mean WTP per household considering the impacts on human health was calculated using the estimated bivariate probit model. The econometric model indicates that individuals with higher incomes and those in younger age categories are more likely to pay. The findings of this study can be used to inform policymakers to allocate financial resources to prevent these types of incidents in the future.
Keywords: Nanoplastics, Willingness to pay, Economic valuation, Healt
Integrating Community Engagement in Sustainable Forest Management: Strategies for Resilience and Biodiversity
No full textForests are vital ecosystems that play a crucial role in maintaining ecological balance, supporting biodiversity, and providing livelihoods for millions of people worldwide. This study underscores the critical need for integrating community engagement in sustainable forest management (SFM) as a strategy to enhance resilience and protect biodiversity. The importance of this research lies in its potential to inform policy and practice by demonstrating how local involvement can lead to more effective and sustainable forest management outcomes. The primary objectives of this study are threefold: first, to evaluate the effectiveness of community engagement strategies in SFM; second, to identify key barriers that hinder meaningful participation; and third, to propose actionable recommendations for fostering collaboration between local communities and forest management authorities. To achieve these objectives, a mixed-methods approach was employed. This involved quantitative analyses of forest health indicators, such as biodiversity metrics and carbon storage capacity, alongside qualitative interviews with a diverse range of stakeholders, including community members, local leaders, non-governmental organizations (NGOs), and forestry officials. The research was conducted across multiple forest ecosystems, allowing for a comprehensive examination of various engagement practices and their outcomes. Key findings from the study indicate that communities actively engaged in forest management exhibit significantly better ecological outcomes compared to those where community involvement is minimal. Successful case studies highlight the integration of local knowledge and practices into management frameworks, which not only enhances sustainability but also fosters a sense of ownership among community members. For instance, areas where traditional ecological knowledge is utilized in forest planning have shown improvements in biodiversity conservation and ecosystem resilience. However, the research also identifies several barriers to effective community engagement, including limited access to resources, insufficient training opportunities, and bureaucratic obstacles that often prevent meaningful participation in decision-making processes. The study concludes that fostering inclusive governance structures is essential for achieving sustainable forest management. Policymakers are encouraged to develop frameworks that empower local communities by providing them with the necessary tools, resources, and authority to manage their forest resources effectively. Additionally, integrating scientific research with traditional ecological knowledge can enhance the understanding of local ecosystems, ensuring that management strategies are both context-specific and culturally appropriate. This research contributes to the broader discourse on sustainable forest management by highlighting the vital role of community engagement in promoting resilience and biodiversity. It advocates for a paradigm shift towards participatory governance, emphasizing that local voices must be at the forefront of conservation efforts to achieve long-term sustainability. By prioritizing collaborative approaches, this study asserts that it is possible to create sustainable management systems that benefit both the environment and the communities that depend on these vital resources. Ultimately, the findings underscore the importance of recognizing local communities as key partners in forest management.
Keywords: Forests, Management, Policies, Researc
Increasing the Biodiversity of Habitats around Sri Lankan Railway Systems
No full textThe increasing fragmentation of natural habitats in Sri Lanka due to urbanization and infrastructure development has left vast stretches of land underutilized and ecologically degraded, such as the spaces to the sides of the railroads. This is quite evident in the Kelani Valley Line, where from Maharagama to Maradana most of the spaces adjacent to railroads are either infrastructure, including illegal settings, or spaces overrun by weeds. The focus of this study is to assess the effectiveness of rewilding these empty spaces along railroads to restore urban biodiversity and mitigate the environmental impact of transportation networks. To assess the potential for rewilding, a biodiversity survey was conducted along the 1.2-kilometer railroad corridor between Nawinna and Maharagama railway stations. The methodology involved detailed observation and documentation of flora and fauna surrounding the railway, with species identification supported by the citizen science platform iNaturalist. Surveys were conducted over two months from September to October 2024. Results showed that the floral community with more than 50 plant species located near the railroad comprises a mix of introduced species accounting for 65% of the flora species identified (Eg: Senna occidentalis, Xanthosoma sp., Euphorbia sp., Tridax sp., Syngonium sp., Asystasia sp., Mikania sp.) and some native species that accounted for 20% of the plant species (Eg: Colocasia sp., Commelina sp., Terminalia sp., Ficus sp., Macaranga sp.) found, which are abundant in urban habitats, with the rest being cultivated plants (Eg: Coffea arabica, Carica papaya, Canna sp.). In addition to the flora, the railroad habitats also hosted a range of native fauna, which included native grasshoppers (Oxya sp.), orb-weaving spiders (Argiope aemula), and seed-eating birds such as munias (Lonchura sp.). Vegetation extended to approximately 1-2 meters to the Railway roadside from the railroad, and 5-8 meters to the opposite side, consisting of mostly neglected landscapes of overgrown weeds mentioned above. Challenges included difficulties in accessing certain overgrown areas, while certain sections of the surveyed railroad corridor were entirely cleared of vegetation, resulting in the absence of any observable flora or fauna. Despite these hurdles, with these data gathered at surveys, it is possible to conclude that spaces near railroads are often dominated by invasive weeds and common fauna associated with degraded urban ecosystems. Thus, there is the opportunity to improve upon these spaces by potentially replacing their mostly introduced floral communities with native plants that can sustain native, yet persistent ecosystems with higher diversity.
Keywords: Rewilding, Urban biodiversity, Invasive species, Railroad ecology, Ecological restoratio
Estimating Households’ Willingness to Pay for Composting of Solid Waste: A Choice Experiment Approach
No full textRapid urbanization and a growing population cause difficulties in managing household waste in Sri Lanka. Improper management of household waste adversely affects both the environment and public health. Composting is an effective practice that lessens the adverse effects of household waste. Therefore, this study employed the choice experiment approach to analyze the households’ preferences and willingness to pay for solid waste composting. This study considered attributes such as composting, recycling, separation, and payment. A random sample of 331 households was selected in the Jaffna Municipal area. The random parameter logit and latent class models were used to estimate the households’ preferences for attributes chosen for this study. The findings of this study revealed that households are willing to pay more for waste collection (LKR 761.40), followed by waste composting (LKR 466.47), waste recycling (LKR 367.73), and waste separation (LKR 303.99). Moreover, respondents’ age and household monthly income significantly influence their preference for composting. The latent class model identified two classes. The latent class model results suggest that respondents in class one (environment-conscious households) had a significantly higher willingness to pay (WTP) for waste composting, at LKR 1,239.58, compared to class two (payment-conscious households), whose WTP for waste composting was LKR 100.29. This study's findings will help policymakers or local municipal councils design an effective service payment system for managing household solid waste and composting, which will help to address the challenges associated with household solid waste.
Keywords: Composting, Latent class model, Random parameter logit model, Solid waste, Willingness to pay
 
Investigation of Some Selected Rice Landraces for C4 Photosynthetic Traits
No full textAchieving food security amidst rapid climate change necessitates an increase in rice production, a crucial food crop for over half of the global population. One promising approach in this regard is the introduction of the more efficient C4 photosynthesis into the rice plant, which is driven by C3 photosynthesis. However, despite numerous attempts, the absence of a leaf anatomy compatible with C4 photosynthesis still acts as a major roadblock to successfully implement the complex C4 biochemistry into the rice plant, and the identification of phenotypes with a naturally occurring C4-like leaf anatomy could potentially act as a stepping stone in the introduction of C4 photosynthesis into rice. Therefore, this study aims to investigate some selected Sri Lankan rice landraces for the presence of C4-like leaf anatomical characteristics, such as high leaf vein density, reduced mesophyll cell number, and low stomatal density, by comparing them with those of two representative C4 grass species, Setaria italica and Echinochloa colona. Leaf samples were collected and fixed six weeks post transplantation. For the measurement of vein density, leaf sections were cleared using a KOH gradient, and stomatal density measurement was carried out on both nail polish stomatal imprints and leaf sections cleared using an 85% Lactic acid: 1% chloral hydrate solution, depending on the species. Mesophyll cell counts were taken by clearing leaf sections using the same clearing solution. All the measurements were carried out on the photomicrographs captured using a digital light microscope. Each of these measurements were represented by 15 measurements of five leaf blades taken from five different plants. Our findings highlighted that, despite none of the landraces showing comparable leaf anatomical characteristics to S. italica and E. colona, interestingly, Pachchaperumal stood out for its highest vein density, lowest mesophyll cell number, and relatively lower stomatal density among the rice landraces tested, showing a possible adaptation to reduce transpiration and maintain the hydraulic integrity in the hot tropical microclimate of Sri Lanka, similar to the conditions under which C4 photosynthesis evolved. Apart from that, in our study, two other landraces, Hondarawalu and Niyanwee, were also selected as high vein density candidates. Overall, we present three candidates as a germplasm source for future studies in understanding the establishment of C4-compatible leaf anatomy in a C3 rice plant, namely, Hondarawalu, Niyanwee, and especially, Pachchaperumal, which could meaningfully contribute to the ongoing work of the development of C4 rice.
Keywords: Food security, C4 photosynthesis, C4 rice, rice landraces, C4 leaf anatom
Enrichment of Municipal Solid Waste Compost with Native Free-Living Diazotrophic Bacteria to Enhance the Plant Available Nitrogen
No full textComposting is one of the sustainable solutions for Municipal Solid Waste (MSW) management. However, the applicability of MSW compost for agricultural purposes is limited due to the relatively lower availability of Nitrogen (N). N is considered one of the primary macronutrients required for plant growth. Thus, the present study focuses on the enrichment of MSW compost with native free-living diazotrophs isolated from open dump sites and soil from agricultural lands in the western province of Sri Lanka. Bacteria were isolated using nitrogen-free Ashby’s mannitol medium and Winogradsky’s medium, and their nitrogen fixation potential was evaluated using spectrophotometric methods. The isolates with the highest nitrogen fixation potential were selected for consortia preparation and identified through 16S rRNA molecular analysis. Moreover, their single and synergistic compatibility to enhance the plant available N in MSW compost was evaluated using a pot experiment with Capsicum annuum as the test plant. Based on the results, 12 morphologically different bacterial isolates were isolated as nitrogen-fixing bacteria, and out of those two potential bacterial strains (N2-Bacillus altitudinis and N3-Lysinibacillus macroides) were selected for consortia preparation to enhance the plant available N in MSW compost. The enriched compost with N2N3 consortia showed significantly higher (p≤0.05) levels of plant available Nitrogen in nitrate and ammonium concentrations compared to the control. Furthermore, the results of the pot experiment showed that the enriched compost with N2N3 consortia increased the plant growth parameters during the early growth of Capsicum annuum (root length (cm); 72±2%, shoot length (cm); 25±1%, Number of leaves per plant; 13±1%). Thus, this study provides a cost-effective, eco-friendly alternative to imported and expensive chemical fertilizers, providing valuable insights into sustainable agricultural practices and waste management strategies.
Keywords: Biofertilizer, Bacterial consortia, Compost enrichment, Free-living diazotrophic bacteria, Municipal solid waste compos
From Wilderness to Urbanity: The Adaptation of African Green Monkeys in Bangkok’s Abandoned Forest Areas
Get PDFThis study investigates the adaptation and survival of non-native African green monkeys (Chlorocebus sabaeus) in an abandoned urban forest area of Bangkok, Thailand. Combining ethnographic and ecological fieldwork, we explored the factors shaping their establishment, focusing on their interactions with the local environment and human community. Key findings reveal that the Mon community, guided by Buddhist beliefs and traditions of animal veneration, plays a critical role in fostering a symbiotic relationship with the monkeys by providing essential resources such as food and shelter. Ecologically, the monkeys have adapted well to the urban forest without causing major disruptions to local biodiversity; however, concerns about unregulated population dynamics warrant attention. To address potential risks and ensure sustainable coexistence, we propose a community-based management strategy that integrates cultural practices, ecological monitoring, and legal recognition of the monkeys as part of Thailand’s wildlife heritage. Specifically, this approach emphasizes collaboration between local stakeholders, such as the Mon community and landowners, alongside governmental agencies. Our findings contribute to broader discussions on urban wildlife adaptation and highlight the importance of integrating cultural and ecological perspectives in managing non-native species.
Keywords: Chlorocebus sabaeus, Non-native species, The Mon people, Environmental law
Optimization of Waste Glass Powder Content to Improve the Mechanical Properties of Concrete Mixers
No full textConcrete is the largest used building material in the world. Use of waste and by product material as partial substitute material in concrete is now trending in the world construction industry in order to produce sustainable concrete and reduce the environmental impact due to over consumption of resources. This study focus to replace the Portland cement by waste glass powder in the concrete mixture. Mechanical properties such as the compressive and tensile strengths were calculated with the laboratory experiment. A 0%, 5%, 10% and 15% volumetric replacement of cement by glass powder is considered and strength was calculated in 7, 21, and 28 days of curing. The results showed the addition of different mixes of glass powder into concrete is an effective solution for the depletion of raw materials and eco-friendly materials. Furthermore, this is the solution for the waste disposal of glass packaging material. Even though correct proportions should be maintained throughout the usage to obtain the desired strength in tensile, and compressive strength. The workability of the concrete is measured with the slump test of the concrete mixes. Slump test results showed that the slump increased when the glass powder percentage increased in concrete. The maximum slump value was 121mm in the addition of 15% of glass powder. Compressive strength increased from 7 days to 28 days of curing. Compressive strength is maximum at the 10% of waste glass powder which is 28.5Nmm-2. Split tensile strength increased along the curing and the maximum tensile stress was obtained when the waste glass powder is 10% such that is 14.1Nmm-2. The study concludes the better mechanical properties can be obtained in concrete with the presence of waste glass powder rather than conventional concrete.
Keywords: Waste glass powder, concrete compressive strength, split tensile strengt