Mathematical Modeling of a Renewable Energy- Connected PEM Water Electrolyzer

This study provides the framework for optimizing a renewable energy-connected PEM electrolyzer. PEM electrolyzer was primarily enforced onto the electrolyzer process and different electrolyzers. The Key factors that need to be considered for the electrolyzer modeling process such as basic principles, modeling equations, and stack structure. There are several coupling technologies between solar PV and electrolyzers, such as direct coupling, coupling via an electronic converter, and battery- assisted electrolyzer. A mathematical model of solar PV-connected PEM electrolyzer is developed in this project. Then the mathematical model is optimized using optimizing parameters such as the temperature of solar PV, and the Operating temperature of the PEM electrolyzer of the PEM electrolyzer

Evaluation of the Photocatalytic Activity of Chitosan-G-C3N4 Composite for Methylene Blue Degradation

The growing concern over environmental pollution has driven research into effective, sustainable solutions, particularly in the field of water treatment. This study investigated the photocatalytic activity of a chitosan- g-C3N4 composite, aimed at degrading methylene blue (MB), a prevalent organic dye and pollutant in wastewater. Chitosan (CS) was synthesized from shrimp shells using a series of chemical processes, including demineralization, deproteination, and deacetylation, while graphitic carbon nitride (g-C3N4) was synthesized via thermal treatment of urea. The composite was prepared by mixing varying ratios of CS and g-C3N4, and its photocatalytic efficiency was tested against MB solutions of different concentrations under visible daylight including MB solution, chitosan and MB solution, g-C3N4 and MB solution as controls. Results showed that the chitosan-g-C3N4 composite effectively degraded methylene blue, and the degradation efficiency depends on the composite ratio and MB concentration.  The highest rate constant of 10.6 × 10⁻³ min⁻¹ was obtained with 2 ppm MB solution using 1:1 ratio of CS to g-C3N4, while a 1:2 ratio demonstrated optimal degradation rates for both 4 ppm and 5 ppm MB solutions, achieving a rate constant of 6.5×10⁻³ min⁻¹. The 1:2 ratio of chitosan to g-C3N4 consistently provided one of the most efficient degradation rates across concentrations, especially at 2 ppm. These findings underscore the potential of g-C3N4 and its composites with chitosan, particularly those with higher g-C3N4 content, to significantly improve photocatalytic degradation of MB compared to chitosan alone. The optimum performance was achieved at lower MB concentrations (2 ppm), with the 1:1 and 1:2 ratios being particularly effective. The enhanced photocatalytic activity is attributed to the synergistic interaction between chitosan and g-C3N4, where chitosan’s adsorption properties complement the photocatalytic abilities of g-C3N4 by facilitating the separation of photogenerated electron-hole pairs and reducing recombination. This study highlighted the potential of using chitosan- g-C3N4 composites for wastewater treatment applications. By utilizing waste-derived chitosan, this approach not only enhances photocatalytic processes but also contributes to sustainable material development. The findings suggest that the composite can serve as an eco-friendly, cost effective, and efficient photocatalyst for degrading organic pollutants in wastewater, making it a promising and scalable solution for addressing water contamination challenges. Keywords: Photocatalysis, Chitosan, g-C3N4, Methylene blue, Wastewater treatmen

Factors Affecting Growth, Survival and Leaf Functional Traits of Tree Saplings Planted Along a Successional Chrono-Sequence in Endane Biodiversity Corridor in Southwestern, Sri Lanka

The growth of a sapling is influenced by species, succession, and habitat characteristics such as shade and elevation. Forest restoration efforts often fail due to insufficient consideration of habitat characteristics and site-species suitability. In this study, we examined how habitat characteristics, successional age and elevation affect growth, survival, and functional traits of 13 threatened tree species planted in Endane Biodiversity Corridor in Southwestern Sri Lanka. The growth parameters and selected leaf functional traits in 13 threatened tree species interplanted within four successional ages (marginal tea, scrub, woodland 1, and woodland 2) with contrasting elevation and canopy closure were measured after one year of planting and analyzed using a linear mixed-effect model. We found that mean annual height growth in different habitats increased significantly with successional age, from the highest being in shaded woodland, the lowest growth (p<0.001) in open marginal tea habitats. Mean annual diameter growth also varied by successional age but did not follow the same trend as height growth due to differences in canopy closure. A strong positive correlation was observed between height and diameter growth one year after planting (r=0.71, p<0.001). Chlorophyll content increased with succession, the highest in a shaded woodland (p<0.001). In contrast, leaf dry matter content (LDMC) and leaf mass per area (LMA) decreased with successional age, with marginal tea showing the highest values (p<0.001). The LMA variability was explained by LDMC (r=0.41, p<0.001) and leaf thickness (LT) (r=0.42, p<0.001). These results provide valuable insights into long-term monitoring of restoration success in Endane Biodiversity Corridor in Southwestern Sri Lanka. Keywords: Mean annual height growth, Species selection, Specific leaf area, Specific dry matter conten

Developing Timber Classification Systems for Sri Lanka based on Wood Properties and End Uses

This research develops enhanced timber classification systems for Sri Lanka, based on wood properties and end-use applications. The study analyzed wood properties of 60 timber species which are included in eight classes of the current timber classification of State Timber Corporation (STC), assessed the durability and applications through local carpenter surveys and proposed improved classification systems integrating wood property analysis, survey results, and international comparisons. Wood property analysis included the wood density, Modulus of Rupture (MOR), and Modulus of Elasticity (MOE). Through expert consultations, the analysis yielded a four-category quality-based classification system (Q1 to Q4) focused on structural applications. This data-driven approach revealed significant differences from the existing STC classification. While high-quality (Q1) species like Satin and narrow-leaved Mahogany aligned with higher STC groups, other Q1 species such as Hora and Coconut were categorized in lower STC groups (fifth and sixth groups of STC classification). Notable discrepancies included Q3 species like Jack (classified in STC's second group) and Q4 species including Toona, Cypress, and Lunumidella (classified in sixth group of STC classification). The research further classified the wood species according to dimensional stability using the Tangential/Radial (T/R) ratio, durability characteristics and end-use suitability. These classification systems provide a scientifically grounded framework for timber selection process in Sri Lanka, enabling evidence-based decision-making and optimal utilization of timber resources across various applications. Keywords: Timber classification, Structural applications, Dimensional stability, Durability, Expert consultations &nbsp

Characterization of Fusarium oxysporum Causes Foot Rots of Capsicum annum L. of Sri Lanka and Its Control with the Use of Endophytic Fungi

One of the major diseases of Capsicum annum L. focused on in this study is fungal foot rot which is caused by Fusarium oxysporum. Because of adverse effects of chemical fungicides, biological management of diseases is suggested for sustainable food production. Within the study, the ability to suppress disease by endophytic fungi was tested with the aim of evaluating the efficacy of endophytic fungi as potential bio-control agents against referred disease. Throughout the methodology, standard procedures were used. Isolation and identification of Fusarium oxysporum were done in different places in Kandy. All samples were washed using running tap water, and about 1cm2 sections, including the edges of lesions, were cut, surface sterilized, placed on Potato Dextrose Agar (PDA), and incubated at room temperature until colonies appeared. Fungal colonies that emerged from lesions were sub-cultured onto fresh PDA, and pure cultures were prepared. The pathogenicity of the isolated pathogen was confirmed via standard Koch’s Postulate. Fusarium isolates were identified morphologically, and species-level identification was done by extracting genomic DNA and amplifying and sequencing ITS-1 and ITS-4 regions. Endophyte isolation was done similarly to the above procedure of pathogen isolation from roots and aerial parts of the healthy Capsicum plants. After screening endophytic fungi, the antagonistic effect against Fusarium oxysporum was tested with dual plate assay.  With the aid of morphological and molecular characteristics, the foot rot pathogen was confirmed and identified as Fusarium oxysporum. As a result of endophyte isolation; five different endophytic fungi were isolated (Talaromyces sp, Purpureocillium sp, Trichoderma sp, Eupenicillium sp, and Trichoderma sp). According to the results of the dual plate assay and Tukey’s pairwise comparison of five different assays with three replicates, Purpureocillium lilacinum. (49.4067%), Talaromyces purpureogenus (2883120) (62.9409%), Trichoderma spp. 1 (58.9422%), Eupenicillium spp. (62.7285%) and Trichoderma spp. 2 (63.043%) showed significantly high (p≤0.05) inhibition of Fusarium oxysporum colony growth. Microscopic observations of inhibition zones between Fusarium oxysporum and effective endophytic fungal colonies showed the presence of haustoria, coils, loops, and knobs, as mycoparasitic structures indicating their potential as biocontrol agents. According to the results, it could be concluded that all tested Endophytic fungi species (Talaromyces sp, Purpureocillium sp, Trichoderma sp 1, Eupenicillium sp, and Trichoderma sp2) can control the Fusarium oxysporum in an in vitro condition. Current study can go forward with further studies such as application method studies, field trials and develop a bio-control fungicide. Keywords: Endophytic microflora, Fungal foot rot, Fusarium oxysporum, Sri Lank

Evaluating Shoot Performance of Vertical and Horizontal Placement of Insulin (Costus igneus) Stem Cuttings Grown in Soil with Tea Waste and Cattle Manure

Costus igneus (Insulin plant) is a member of the Costaceae family of medicinal herbs which has the ability to help the body produce more insulin. This plant is vegetively propagated by using stem cuttings. An experiment was carried out at Gonawala in Gampaha district, Sri Lanka to study the impact of tea waste and cattle manure on the shoot performance of insulin stem cuttings and also to evaluate their efficiency on vertical and horizontal orientational placement of cuttings. It was arranged in a completely randomized design with eight treatments. Each treatment had three replications, and this experiment was repeated twice. Poly Bags were filled with only soil (T1, T5), soil + tea waste at 1:1 ratio (T2, T6), soil + cattle manure at 1:1 ratio (T3, T7) and soil + tea waste + cattle manure at 2:1:1 ratio (T4, T8) as potting media. Subsequently semi-hard stem cuttings approximately 5 cm in length with single nodes were placed horizontally in T1-T4 and vertically in T5-T8 treatments. Leaf length and width, number of leaves and newly developed shoot length were taken at 8th week after planting of the cuttings. The data collected were analyzed by analysis of variance using SAS software application. The results showed that there were significant variations (P<0.01) in the leaf number and shoot length among the treatments and T4 had significantly higher leaf number (10.3) compared to the other treatments except T8. The highest shoot length was observed in T4 (9.5 cm) and the lowest length was indicated by T1 (6.5 cm). In horizontal placement of cuttings (T1-T4), shoots were developed from cuttings within the first two weeks but in vertical position, (T5-T8), it took nearly four weeks to develop the shoot. According to the marked values, there was a significant variation (P<0.001) in the length of 1st and 2nd leaves among the treatments. The highest and lowest length of 1st and 2nd leaves resulted in T4 and T5 respectively. However, there was no significant difference (P>0.05) in the width of 1st and 2nd leaves. The combination of locally available tea waste and cattle manure had the greatest effect on the formation of shoots from the insulin stem cuttings. In horizontally placed cuttings, shoots were induced quicker than the cuttings placed vertically. This may be due to horizontal cuttings exposing a larger surface area to the soil than the vertical placement of cuttings. The findings showed that stem cuttings can be placed horizontally in a potting medium containing locally available household tea waste and cattle manure for the effective plant propagation of Costus igneus. Keywords: Costus igneus propagation, Tea waste, Cattle manure, Horizontal and vertical placemen

Preliminary Study of Sea Urchins Associated to Two Locations in Southern Coast of Sri Lanka

Sea urchins (Echinodermata) are an essential class of herbivores in both temperate and tropical food webs. They maintain the amount of macroalgal cover, affecting primary productivity and phase changes on reefs. The sea urchin has been recognized as a cultivable marine invertebrate species because of its commercial potential. This study aims to determine sea urchin diversity and abundance at two locations covering the Pareiwella and Polhena coral reefs in southern Sri Lanka. The study was carried out using permanent transect sampling method and transects were parallel to shoreline with the length varying from 10m-20m at the selected sites during low tide at 0.5m-1m depth range in Pareiwella and 0-0.5m depth range in Polhena to estimate the sea urchin abundance during December 2023 to January 2024. In the field, a 0.5 m × 0.5 m quadrate was placed along transects at permanent points, and each species of sea urchin was counted within the quadrate. The abundance and diversity of Sea urchins at two sites were estimated, and their mean values were compared. According to the results, a total of 4-6 sea urchin species (Diadema setosum, Stomopneustes variolaris, Toxopneustes pileolus, Tripneustes gratilla, Echinothrix calamaris and Echinometra mathaei from Polhena and Diadema setosum, Stomopneustes variolaris, Tripneustes gratilla, and Echinometra mathaei from Pareiwella) were identified between the two sampling sites. On the Pareiwella and Polhena site, sea urchin distribution is recorded as 33 individuals m-2  and 12 individuals m-2 respectively. Shannon Weiner index of diversity was highest in Polhena (H’=1.1). Results showed the dominance of Stomopneustes variolaris in Polhena reef and Echinometra mathaei in Pareiwella reef. Stomopneustes variolaris and Echinometra mathaei resulted in higher abundances for distribution in the Pareiwella and Polhena site respectively. Further studies are necessary to investigate the feeding preference of sea urchins in a wider context. Keywords: Sea Urchins, Diversity, Abundance, Distribution&nbsp

Comparative Study on Innovative Financing Strategies in Protected Area Network Management; India, Indonesia, Thailand, South Africa and Sri Lanka

Global biodiversity is threatened due to many reasons and biodiversity hotspots are in the forefront of the risk posed by declining biodiversity. Protected Area which is defined by International Union for Conservation of Nature as a clearly defined geographical space, recognized, dedicated and managed, through legal or other effective means, to achieve the long-term conservation of nature with associated ecosystem services and cultural values, play a significant role in conservation of biodiversity, and the effectiveness of Protected Area management has direct and indirect impact on the overall biodiversity management in the countries and globally. However, limited financial resources for biodiversity conservation through traditional public financing mechanisms has been identified as one of the fundamental challenges of Protected Area management, and its effectiveness. In this context, innovative financing mechanisms become the alternative. Objective of this comparative study was to examine the potentials, challenges and approaches of innovative financing solutions, which increase the volume, efficiency, and effectiveness of financial flows for Protected Area management. Among 36 listed biodiversity hotspots, India, Indonesia, Thailand, South Africa and Sri Lanka were selected due to the locational factors, percentage of declared Protected Areas, and availability of literature, including the officially validated reports on the use of innovative financing strategies. Adhering to the qualitative methodology and case study strategy, primary and secondary data were gathered through the reviewed journals, officially validated reports, and having ten Key Informant Interviews with the relevant sector officials and experts. The NVivo 10 version was utilized for the analysis. The percentage of Protected Areas in India is 5.28%, 15% in Indonesia, 17% in Thailand, 9.2% in South Africa and 30% in Sri Lanka. Key findings of the study were the need to adapt Protected Area management strategies to match with the evolving conservation policies which will reduce misalignments between the policies and practices; need to identify a balance of conservation priorities between the intrinsic conservation value and monetization of ecosystem services provided by the Protected Areas; need to consult and involve stakeholders including the communities living in close vicinities to the Protected Areas in developing and implementing innovative financing instruments; and the need to introduce internationally comparable mechanisms and tools such as  Management Effectiveness Tracking Tool to improve cross learning between the conservation managers operating in similar contexts.   Keywords: Protected areas, Innovative finance, Management effectivenes

An Ethnobotanical Survey of Medicinal Plants in Thoranamalai Hill in Thirunelveli, Tamil Nadu, India

Thoranamalai hill looks like an elephant; hence it is called as Vaarana hill.  It was believed that Agathiyar stayed here and did research on medicines. The way from downhill to hilltop is full of greenery. There are herbal plants all along the way to the hill temple. The temple’s specialty being that there are sixty-four natural water springs (Sunai) around the Hill. It is believed that if devotees take bath in these springs will cure their skin diseases. An Ethno-botanical survey was carried out to record information on medicinal plants from Thoranamalai hill. The aim of the study is to identified and documented the Medicinal plants available in the Thoranamalai Hill. Field survey was done, and Medicinal plants were identified with the help of the common public and data was confirmed by traditional practitioners with direct interview conversation. According to this survey, 216 Medicinal Plants were identified and documented. Commonly, These Medicinal plants were belonging to Fabaceae Family. 57% of Shrub taxonomy medicinal plants were recorded. Most of the medicinal plants have medicinal properties. Six rare medicinal plants were identified. Identified Medicinal plants were conservatized and preserved in ornamental areas. Medicinal plants can collect from wild resources and utilized for medicine preparation and get more efficacy to treat the diseases. Keywords: Thoranamalai Hill, Medicinal plants, Ethno-botany, Traditional medicine

Development of Bacillus spp. Consortia as Phosphate-Solubilizing Biofertilizers to Enhance Plant Growth: A Sustainable Agricultural Approach

The global population continues to rise steadily, making it increasingly challenging to feed the growing number of people without a substantial increase in agricultural production. The concept of biofertilizers has emerged as an innovative solution to enhance soil fertility and agricultural productivity. This study aims to isolate and characterize phosphate-solubilizing bacteria (PSB) and assess their effects on plant growth promotion as a sustainable approach. Compost soil was collected from the Karadiyana open dump site (6°48′51.8′′ N, 79°54′17.0′′ E) to isolate PSB strains. Pikovskaya’s Agar (PKV) were used to isolate PSB strains and identified through biochemical tests and 16S rRNA gene sequencing. Quantitative phosphate solubilization was measured by determining the production of available phosphorus in Pikovskaya broth medium supplemented with 0.5% tricalcium phosphate, while qualitative phosphate solubilization was assessed by calculating the Phosphate Solubilization Index (PSI) for each isolate. PSB-incorporated consortia were prepared by mixing isolated PSB strains, maintaining a concentration of 108 CFU/mL with absorbance values ranging from 0.5 to 0.9 at 595 nm. The effects of these consortia on plant growth were evaluated through pot experiments using salad leaves and radish plants, with growth parameters including shoot length, root length, fresh weight, dry weight, seed germination time, number of leaves, leaf area, leaf width, and leaf length measured. The isolated strains were identified as belonging to the genus Bacillus, with Bacillus siamensis strain KCTC 13613 showing the highest production of available phosphorus (171.2±0.3 µg/mL) on the fourth day of incubation. Pots inoculated with PSB consortia demonstrated a significant increase in all measured growth parameters for both salad leaves and radish compared to the control (p<0.05). These findings reveal the potential of Bacillus spp. as bio-inoculants to promote sustainable agriculture by enhancing phosphorus availability and plant growth. Keywords: Bacillus spp, Biofertilizers, Phosphate-solubilizing bacteria, Plant growth promotion, Sustainable agricultur