Browsing by Author "Ediriweera, E.P.S.K."
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Item Adult-Recruit Spatial Association of Shorea Species Determined by Topographic Variation in a Mixed-Dipterocarp Tropical Rainforest, Sri Lanka(Uva Wellassa University of Sri Lanka, 2021) Jayasinghe, G.J.M.S.R.; Wijekoon, P.; Wiegand, T.; Ediriweera, E.P.S.K.The spatial distribution of recruits around conspecific adults of woody species conveys detailed insights on the mechanisms governing species co-existence in tropical rainforests. Hence, we studied adult-recruit association of eight Shorea species (Shorea affinis, S. congestiflora, S. cordifolia, S. disticha, S. megistophylla, S. trapezifolia, S. stipularis, S. worthingtonii) in the Sinahraja Forest Dynamic Plot, using spatial point pattern analysis. The adult-recruit spatial patterns were extracted from four censuses in 1996, 2001, 2006 and 2011 conducted at the plot. We used slope, elevation, aspect, curvature, topographic wetness index and seventeen soil nutrients as habitat variables. To assess the adult-recruit spatial relationship, we used two null models created by the pattern reconstruction method. The null model of independence distributed recruits independently on conspecific adults without considering habitat association, but maintained their observed aggregation. In contrast, the Heterogeneous Poisson Process considered additionally the effect of topographic variations. Departures from the null models were assessed by simulation envelopes and goodness-of- fit tests using the bivariate distribution function of nearest neighbor distances and the bivariate pair correlation function. S. trapezifolia and S. stipularis indicated independent placement of recruits around adults for all distance intervals of 1-120m while other species showed significant positive association, for all distance intervals of 1-50m. Thus, the majority of recruits of Shorea species showed positive associations with conspecifics adults at medium spatial scale which implies high interference of individuals of Shore species with conspecifics. Based on the fitted intensity functions of recruits, slope, elevation and soil nutrients were identified as the main environmental factors influencing the bivariate adult-recruit spatial distributions of Shorea species. Further, for S. stipularis, the fitted Heterogeneous Poisson Process described the observed pattern well (goodness-of-fit test‟s p-value = 0.15), which suggests that the adult-recruit pattern was mainly driven by habitat heterogeneity. However, departures from the null hypothesis of habitat heterogeneity were shown for all other Shorea species (goodness-of-fit tests‟ p-values < 0.05). We conclude that the heterogeneous environment alone is insufficient to explain the observed patterns of recruits around conspecific adults of Shorea species. Consequently, the impact of other mechanisms on conspecific adult-recruit association should also be studied. Keywords: Adult-recruit association; Intraspecific; Habitat heterogeneity; Heterogeneous Poisson Process; Tropical rainforestItem A Crowdsourcing Approach for Observation of Drinking Water Supply System(Uva Wellassa University of Sri Lanka, 2020) Pavithra, W.S.K.; Shihara, M.F.F.; Ranasinghe, R.M.I.S.; Ediriweera, E.P.S.K.Drinking water availability is a varying factor in Sri Lanka due to weather changes, natural disasters, and the breakage of pipelines. In such situations, people tend to share information regarding a lack of consumable water availability through social networks. That information is decentralized and unorganized so decision-making is difficult. The objective of this study is to represent and summarize up-to-date spatial information of drinking water availability by providing a platform for commercial water utility companies that supply water and customers to meet up and getting the general public and social service involvement. A low fidelity prototype was designed to capture the concept. To test the usability of the solution, a high-fidelity prototype was implemented for a selected set of functionalities such as social login, social sharing, viewing, and filtering posts. The web application was developed using Angular 6, Node.js web framework, and Leaflet, a free JavaScript map library. The system provides dedicated interfaces for customers to post, view information, and the user-friendly interfaces for customers to send request messages without any failures. Each request is recorded together with the geographical location, time, and tag, a search key used to filter outposts. A case study was conducted to test and evaluate the functionalities of the system and the members of the Rotaract Club in Badulla were taken for the case evaluation. The thinking aloud method was used to collect feedback and to capture the user’s thoughts while interacting with the system. Therefore, this system successfully provides a solution to the general public to gain attention on an arising water availability issue, and the commercial water utility companies are provided with a platform to advertise their services and identify areas with potential customers. A future improvement was suggested to adhere to the line and polygon data to achieve advanced Geographic Information System (GIS) features. Keywords: Crowdsourcing, GIS, Web application, Water availabilityItem Detection and Classification of Diseased Tomato Leaf Using Image Processing Techniques(Uva Wellassa University of Sri Lanka, 2016) Mehendran, Y.; Kartheeswaran, T.; Ediriweera, E.P.S.K.Tomato plants are highly vulnerable to fusarium wilt, verticillium wilt, and late blight. The symptom is yellowing of the lower leaves, which gradually wilt and die. The naked eye observation of experts is the main approach adopted for detection and the identification of plant diseases. We developed a method to detect and classify damages in leaves using image processing techniques. For this experiment, images downloaded from the interne were used. The disease regions were segmented using K-Means clustering and the classification of the disease was done with Support Vector Machine (SVM) by training with the selected features from the training set of images. The initial version has three classes such as Bacterial Wilt, Early blight and Healthy tomato leaves. The accuracy level for the identification and the classification of diseases was calculated for each category separately. The accuracy of the system for the selected nine features was calculated as 76.5%. Association among the features as Contrast, Correlation, Energy, Homogeneity, Entropy, Mean, Standard deviation, Skew, and Kurtosis gave the optimum accuracy. This system with high accuracy motivates the other researchers to extend the system with added functionality, which will be a farmer friendly software solution. Keywords: HSI, K-means, Gray-level co-occurrence matrix, Support Vector Machine (SVM),Item Development of manioc (Manihot esculenta) based nutria mix(Uva Wellassa University of Sri Lanka, 2015) Faeema, S.F.; Ediriweera, E.P.S.K.; Tilakaratne, B.M.K.S.A simple, convenient and quick to prepare food product besides being hygienic and convenient to eat is ‘Instant food’. Various technologies are being used to develop “Instant foods” and add immense value to raw material (Pathania et al., 2013). Fruits and vegetables nutritional value is highest when they are fresh, but it is not always possible to consume them immediately. Preserving of vegetables as a means of improving storability has been practiced for many centuries. Life expectancy of Sri Lankans is 68 years for males and 76 years for females in 2006 (Hans et al., 2008). Despite the relatively high literacy rate (90.8% in 2006) in the country (Central Bank Annual Report. 2008), and achievements in economic growth and the nutritional status of children is not satisfactory. The nutrition status shows a wide variation across the districts & as for wasting, it ranges from 10.5% to 28.1% substantiating the geographical disparity (Hans et al., 2008). Therefore, the need to find inexpensive sources of nutritional food of good quality can be over emphasized. Once it is harvested, the agricultural product is edible for only a limited time, which can vary from a few days to weeks. Therefore processing of blends of manioc with murunga leaves, soy beans and banana blossom into forms which combine the advantage of nutritive value, convenience and preservation of use stands a better chance of success. Methodology Manioc flour, soy bean flour (Pb-1), muruga leaves flour and banana blossom flour were prepared. Flour items were analyzed for protein, fat, fiber, ash and moisture following AOAC(1990) methods. Prepared flours were used to prepare nutria mix with either 80% manioc flour and 10% soy bean flour (T1) or 75% manioc flour and 15% soy bean flour (T2) or 70% manioc flour and 20% soy bean flour (T3) or 60% manioc flour and 30% soy bean flour (T4) or 55% manioc flour and 35% soy bean flour (T5), following nutria mix preparation methods. Nutria mixes were analyzed for physico chemical characteristic following Sri Lanka standard methods of SLS 280 (2009). Sensory evaluation was conducted to evaluate and comment on sensory characteristics by untrained twenty sensory panels. Complete Randomized Design (CRD) was performed to compare values obtained from proximate composition. The data gathered from sensory evaluation were analyzed by using Friedman statistical technique.Item Effect of substrate on biochemical expression of Bacterial Biofilms(Uva Wellassa University of Sri Lanka, 2015) Lakmali, N.A.D.; Singhalage, I.D.; Ediriweera, E.P.S.K.; Senevirathne, G.Single or multi species bacteria are agglomerated together with the help of Extracellular Polymeric Substance (EPS) forming bacterial biofilms (BBs). BBs get attached to the biotic or abiotic surfaces. This surface based adhesion alters the biochemical expression of BBs. Under the optimum conditions, the biochemical expression of BBs can be maximized. The BBs can be used in various biotechnological applications like biofertilizers, drug discovery, biofuels etc. (Senaviratne, et al., 2008). Thus, present study figure outs preferable surface for the BBs, which would enhance the functional properties of BBs. Methodology In this experiment, single species bacterial biofilms were formed in glass wool (G), metal fibers (M) and fungal filaments (F) immersed in a Low Cost Medium (LCM). Control (C) was maintained without surfaces or bacterial strain. There were three replicates for each treatment. Completely Randomized Design was followed as the experimental design. Attachment of bacterial biofilm with different surfaces was observed through the microscopy. Biochemical expressions of different biofilms were examined by analyzing the exudates using Fourier Transform Infrared (FTIR) print, polysaccharide, amide, fatty acid I, II, and mixed. Cluster analysis was performed under each window to see the similarity and the differences of the biochemical expressions of bacterial biofilms attached with different surfaces. Statistical analysis was done by using Minitab statistical package (version 16).Item Evaluating the potentials of adopting cleaner production techniques to reduce the manufacturing cost of rice flour and coffee(Uva Wellassa University of Sri Lanka, 2015) Ediriweera, E.P.S.K.; Wijesinghe, T.P.; Peris, V.R.SThe increment of cost of production (COP) whilst consumer pressure for a lower price is a major constraint for the sustainable growth of rice and coffee processing sector in Sri Lanka. Several studies have been investigated to find effective ways of minimizing COP, (Brezet and Schelleman, 1995) however literature do not evidence any use of cleaner production, a waste zeroing system. This study was aimed to evaluate the cleaner production concept in rice and coffee processing sectors, as a solution for minimizing COP. Cleaner production is the continuous application of an integrated preventive strategy to processes, products and services, to increase eco-efficiency and to reduce risks to humans and the environment (Brezet and Schelleman, 1995). Methodology Using Ruhunu Foods (Pvt). Ltd flour and spice processing factory as the host, the production process was analyzed to identify possible waste streams and their causes. Using direct measurements and material balance calculations, the waste streams were then quantified. This was done during a period of one month batch production from both processing sections. The quantified wastes were then expressed in terms of their monetary value. Significant waste streams were identified using Pareto analysis. Control measures for them were suggested using CP philosophy and CP techniques as a guide. Ten minute power logger data were obtained from both hammer mill machine and flour mill machine. Then the power factor correction was done to find the payback period for the energy saving process. Result and Discussion According to the findings of this study, both avoidable and unavoidable wastes occur in the coffee flour manufacturing process. The average loss per batch of money due to avoidable wastes of red rice, white rice and coffee processing are respectively LKR.3885.07, LKR.7612.5, and LKR.1529.39. Significant waste streams which contribute to this monetary loss are stuck red and white rice flour and coffee powder inside the milling and grinding machines (89.75%, 93.59%, 97.46%), rejected coffee beans (59.51%). The possible control measures for these waste streams are good housekeeping, better process controlling and equipment modifications. Ten minute power logger data were indicted both flour mill and hammer mill have a low power factor. According to the power factor correction both milling process takes less than 4 years payback period to recover the cost of the energy upgrade from the energy savings. Usage of premium efficiency motors and capacitor banks will save the energy. Immediate implementation of cleaner production will uphold the company image and increase the quality, productivity, worker satisfaction and profit.Item Fungi in Sri Lankan Ecosystems: A Review of Current Knowledge, and Future Directions(Uva Wellassa University of Sri Lanka, 2021) Chandrathilake, A.G.N.M.; Ediriweera, E.P.S.K.; Singhalage, I.D.Fungi are an incredible source that can be used for the economic development of developing countries like Sri Lanka to achieve the United Nation's Sustainable Development Goals. The utilization of fungal resources towards economic development is considerably less because fungi are one of the groups that have been poorly investigated in Sri Lanka. This study aimed to critically evaluate the knowledge gap of fungal studies in Sri Lanka by considering the status of the South Asian region, the Asian region and the World. Therefore, local, regional and world literature related to fungal studies were collected. Data collection was done by using online available sources, visiting resource places as well as contacting resource persons. Then, the collected 1142 different types of literature documents were referred and classified mainly under basic fungal biological studies and applied fungal studies by considering the areas of studies available. After that, necessary information from the literature of each category was extracted and analyzed the gap concerning the world status through the literature to identify new research opportunities of mycology in Sri Lanka. At present global mycology is in the status of identifying and introducing new fungal divisions, classes, orders and new families by using molecular techniques such as quantitative PCR techniques, DNA barcoding, probe development and effective amplification techniques. The global estimate is about 2.2 to 3.8 million fungal species and out of those 144,000 species have been already named and classified. Thus, over 93% of species are currently not explored and are unknown to science. Currently, the Asian region is the pioneer for fungal discovery. In 2017, 35% of new fungal species were discovered in the Asian region which is the highest fungal discovery percentage among all the regions in the World. Findings of this study showed that Sri Lanka is far behind in the World and the Asian region as approximately 3000 fungal species have been identified out of estimated 25,000 native fungal species. The highest knowledge gap is exhibited in the area of fungal taxonomic research in Sri Lanka. There is a great possibility of implementing fungal research in Sri Lanka. However, collaborative efforts of scientists of different fields are needed with financial support to reveal the fungal resources to be utilized in the economic development of the Island. Keywords: Mycological studies; Fungal diversity; Sri Lanka; Knowledge gapItem Possibility of Using Remote Sensing Techniques as a Tool in Exploration of Marble Deposits in Sri Lanka(Uva Wellassa University of Sri Lanka, 2018) Amarasiri, P.G.S.C.; Jaliya, R.G.C.; Ediriweera, E.P.S.K.Remote sensing with the aid of hyper-spectral data are widely used in mineral exploration. However in Sri Lankan context remote sensing has not been used for mineral exploration due to nonexistence of most of required data and the vegetation cover is one of the major factor that limit the remote sensing approach. From that, the study area Balangoda and Mathale consist of rapid variation in elevation that may cause shadow effect which restrict the reflection of solar radiation. This study investigates the possibility of using freely accessible multispectral data for marble exploration. Classification techniques and topographical features were used to locate calcite and dolomite occurrences in the study area. Shuttle Radar Topography Mission (SRTM) data were used for topographic feature identification and Sentinel2 data were used for accurate classification. Anticline-syncline formations and fractured zones were identified using SRTM data. Effective classified images were obtained from Sentinel-2 and Landsat-8 data processing. Training polygons was used to extract the spectral signature in each data set. Although direct spectral signatures of calcite and dolomite are not prominent in remote sensing images, indirect indicators help in delineating possible mineralizing zones. Decision tree for each data set was used in classification process. This study proves that using relatively high resolution data acquired from Sentinel-2 can be used for more effective classification than Landsat-8 data sets in mineral explanations. Keywords: Remote sensing, Mineral exploration, Marble, SRTM, Landsat-8, Sentinel-2.Item Structure modification of mefenamic acid and evaluate their bioactivities(Uva Wellassa University of Sri Lanka, 2015) Jayamaha, J.M.S.S.; Ediriweera, E.P.S.K.; Jayasinghe, U.L.B.; Kumar, N.S.Thousands of years medicine and natural products have been closely linked through the use of traditional medicines and natural poisons (Phillipson et al., 2001). Lately, pharmaceutical industries mainly pay their attention on natural products and their bioactivities to develop novel drugs which shows promising activities on diseases in humans as well as in plants. Since biological assays are used to detect the biological activity on synthetic compounds and natural products. There are several kinds of bioassays such as, antioxidant, antifungal, phytotoxicity, cytotoxicity and enzyme inhibitory activities (e.g. lipase, α-amylase, α-Glucosidase etc). Though there are several types of bioassays, most pharmaceutical manufacturing industries limited their research activities only towards one or few types of bioassays. There can be hidden bioactivities which are important in medicinally, agriculturally and environmentally. Therefore it is important to study about the other bioactivities too by doing the structure modifications of existing drugs and evaluate their bioactivities using various types of bioassays. By doing the modification of the exiting drug that can be enhanced the efficiency of the drug usage. Mefenamic acid (MFA) which is used as a pain killer from many years ago. It is a Non-Steroidal Anti- Inflammatory Drug (NSAID) which exhibits poor water solubility properties (Dixit et al., 2012). MFA is a prescription medicine used for the relief of mild to moderate pain, including painful menstrual periods (Asl et al., 2008). There can be some hidden important bioactivities which were not studied yet in addition as a pain-killer. The aim of this study was to improve the usages of the drug for industrially, agriculturally and environmentally. Therefore the drug was synthetically modified by acetylation/acylation reaction methods. Methodology Pure MFA was separated from the tablet by using column chromatography technique. Separated pure MFA was subjected to acetylation and acylation reactions according to Arnold et al., 2007. Acylation was carried out with acid chlorides such as acetyl chloride (AC), benzoyl chloride (BC) and crotonoyl chloride (CC), while acetylation with acetic anhydride. Efficiency of the drug and its synthetic derivatives were tested by subjecting to bioassays such as α-amylase inhibition assay (Giancarlo et al., 2006), antioxidant assay (DPPH radical scavenging assay) (Mensor et al., 2001), phytotoxicty (bio-assay with lettuce seed germination) (Drewes et al., 1995) and cytotoxicity (brine shrimp lethality assay) assay using Artemia salina (Subbaraju et al., 2005). The Inhibition percentage was plotted against the sample concentration and the fitted line plot was established. Then IC50value (Inhibitory Concentration) was calculated in order to the 50% inhibition.