Research Papers - School of Natural Sciences
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Publication Embargo A Comprehensive Investigation of Microplastic Contamination and Polymer Toxicity in Farmed Shrimps; L. vannamei and P. monodon(Springer Nature, 2025-02-20) Jayaweera, Y. U; Hennayaka, H. M.A.I; Herath, H.M.L.P.B; Kumara, G. M.P; Mahagamage, M.G.Y.L; Rodrigo, U.D; Manatunga, D. CMicroplastic (MP) pollution poses a significant threat to marine ecosystems, seafood safety, and human health. This study investigates the accumulation of microplastics in two commercially important shrimp species, Litopenaeus vannamei (L. vannamei) and Penaeus monodon (P. monodon), sourced from cluster farming sites in Puttalam, Sri Lanka. Shrimp exoskeletons and edible soft tissues underwent rigorous microplastic analysis, including density separation, alkali digestion, stereo microscopy, and Raman spectroscopy. The results revealed high microplastic contamination, with L. vannamei containing an average of 4.99 ± 1.81 MP particles/g and P. monodon containing 1.87 ± 0.55 MP particles/g. Microplastic sizes varied, with L. vannamei predominantly contaminated with 100–250 µm particles and P. monodon with 500 µm—1000 µm particles. Fiber morphotypes were prevalent in L. vannamei, while blue-colored microplastics were dominant in P. monodon. These comprised polystyrene (PS), nylon 6,6, and polyethylene (PE) which were identified by Raman spectroscopy. Additionally, the study investigated the acute toxicity effects of microplastic polymer combinations using a zebrafish embryo model (FET236 assay). Zebrafish embryos exposed to polyethylene-nylon 6,6 combinations exhibited significant adverse effects on hatching, survival, and heart function at lower concentrations, while polyethylene terephthalate-polystyrene combinations showed no considerable effects. These findings underscore the urgent need for monitoring and managing microplastic contamination in shrimp farming areas. Future research should focus on elucidating the ecological impacts and human health risks associated with microplastic exposure.Publication Embargo Activity enhanced TiO2 nanomaterials for photodegradation of dyes-A review(Elsevier, 2021-12-01) Thambiliyagodage, C. JWastewater generation due to anthropogenic activities has become a tremendous problem that the world is struggling to solve. Dyes release to normal water reservoirs badly impacts the environment causing severe issues. Removal of dyes from wastewater streams is important. The advanced oxidation process is advantageous as the dye molecules are degraded into harmless species. TiO2 is the most promising semiconductor that has been researched. However, the use of it in the visible range is restricted due to its high band gap (3.0 eV). TiO2 has been modified in order to enhance visible light sensitivity. This review mainly focused on the effects of doping TiO2 with metals and non-metals and coupling with metal and non-metal oxides to improve its efficiency in photodegrading dyes. TiO2 doped with Fe, Cu and Ag as the main metal species, N, S, and C as the main non-metals are summarized. Further, the effect of doping with multi non-metals and co-doping of metals and non-metals are also discussed. Moreover, coupling TiO2 with metal oxides and graphene oxide for enhanced photocatalytic activity is also summarized in this review.Publication Open Access Assuring Standards and Quality of Higher Education: Teaching and Learning(Asia Pacific Quality Network (APQN) Conference and AGM 2016, 2016-05-26) Peiris, C. N; Peiris, S; Wickramasinghe, SObjectives and Measurements • to investigate the effectiveness of teaching methods on students’ academic performance and to understand what measurements that someone could apply to improve the learning process. • Measurements: • Various qualities of the teacher • Feedback from Students • Learning ResourcesPublication Embargo Attitude of the Students Towards the Usage of Group Activities as a Remedy for Speaking Anxiety(Faculty of Humanities and Sciences - SLIIT, 2021-03-26) Peiris, A.E.As literature suggests Second Language (L2) speaking has always been a challenge for students. One of the main issues is the apprehension occurring when a learner is expected to perform in the second language (Gardner and MacIntyre, 1993). As facilitators at the tertiary level, it is vital to create a low-anxiety classroom to aid students with L2 speaking anxiety. This research attempts to investigate the perspective of students towards using group activities to alleviate speaking anxiety in the ESL classroom. The sample group consisted of forty-five Post Advanced Level Students from an intensive course in a private institute. A questionnaire prior to any speaking activity and weekly questionnaires while conducting both group and individual speaking activities were given to this mixed ability group to study their attitude towards L2 speaking for three weeks. The participation, behaviour and responses of the closely monitored sample group were observed and evaluated to meet the intended objectives. Initial questionnaire revealed that majority was afraid of L2 speaking due to several reasons. During the second week there was a slight attitudinal change towards the perception on L2 speaking, but there was a drop in the attendance towards the end of the three weeks. As revealed, group activities have helped the students to make an effort to speak as there were students who did speaking activities for the first time in their life. It was concluded that Group activities can be used effectively to a certain extent, and since students preferred group activities more than individual activities, they can be used to bridge the gap between students and L2 Speaking.Publication Open Access Ball milling–A green and sustainable technique for the preparation of titanium based materials from ilmenite(Elsevier, 2022-01-01) Thambiliyagodage, C. J; Wijesekera, RIlmenite is a naturally available mineral that is highly applicable in the synthesis of pure TiO2. Titania mainly presents in four polymorphs as rutile, anatase, brookite and TiO2–B. Titania could be mined from minerals such as ilmenite, leucoxene and rutile among which ilmenite is the main source. Ball milling is a mechanical activation method used before subjecting ilmenite to chemical treatment methods to produce titanium based materials. Effect of milling time, milling intensity, milling atmosphere, the introduction of reducing agents on the particle size, surface area, annealing temperature, and the crystal structure of the products are reviewed. The effect of ball milling on acid digestion of ilmenite in hydrochloric acid and sulfuric acid is discussed. Further, the effect of mechanical activation on hydrothermal treatment of ilmenite is explained in detail.Publication Open Access Biodiversity of fruit and other tree species in the Huruluwewa watershed with emphasis on their economic utility(Postgraduate Institute of Agriculture, University of Peradeniya: Peradeniya, 1997) Amarasinghe, A. A. Y; Peiris, B. C. N; Peiris, SThis stud}1 attempted to determine species and genetic diversity in the Huruluwewa wa'ershed considering basic information on native tree species with emphasis oi i fruit and other tree species of future economic utility. This study :vas carried out in different phases, namely, "reconnaissance survey" leading to specific information of the Huruluwewa watershed to determine the species diversity and "Identification of genetic diversity of fruit tree species" through starch gel electrophoresis techniques. Few groups of fruit tree species showing close similarities were used to establish the "Finger printing" through starch gel electrophoresis to identify the genetic diversity. The existing high degree of species diversity in the Huruluwewa watershed can be categorized into different groups based on their economic utility. These are fruit ti ee species, medicinal plants, firewood species, timber trees, ornamental plants food crops, shade trees, cover crops andfodder crops. Different banding patterns in the starch gel electrophoresis established for fruit tree species with closn morphological similarities, indicated the genetic diversity within and among fruit tree species in the watershedPublication Open Access Breeding and selection of tomato F1 hybrids for yield and fruit quality characters(Postgraduate Institute of Agriculture, University of Peradeniya: Peradeniya, 2005) Alwis, L. M. H. R; Perera, A. L. T; Fonseka, H; Peiris, C. NTomato (Lvcopersicon esculentum Miller) of the family Solanaceae is one of the most important vegetable crops grown in Sri Lanka. To understand the actual consumer requirements, especially in terms of fruit quality characters, an extensive survey was carried out. Results revealed that for home consumption, a majority preferred acidic, round to flatshaped, medium-sized fruits, red in colour for curries, salads and sandwiches. The Government of Sri Lanka has also identified the production of local vegetable hybrids as a matter of high priority. With this information, a half diallel genetic crossing design was carried out to produce 36 F, hybrids using nine local and foreign varieties at the Agricultural Biotechnology Centre, University of Peradeniya. These were evaluated in the Meewatura farm of the Faculty of Agriculture, University of Peradeniya. Yield and fruit quality characters including brix, acidity and fruit shape and colour were evaluated. General combining ability (GCA) and specific combining ability (SCA) were significant indicating the importance of both additive and dominance gene action. Out of the 36 Fi tomato genotypes; T068 was selected as the best hybrid for the tourist industry as it showed heterobeltiosis for yield (48%) and low acidity, while T025 was selected as the best hybrid for local consumption as it too showed heterobeltiosis for yield (76%) with high acidity. Both hybrids showed that yield potentials were much higher than the currently used varieties.Publication Open Access Calcium/calmodulin activation of two divergent glutamate decarboxylases from tobacco(Oxford University Press, 2003-08-01) Yevtushenko, D. P; McLean, M. D; Peiris, S; Cauwenberghe, O. R. V; Shelp, B. JGlutamate decarboxylase (GAD, EC 4.1.1.15) catalyses the α‐decarboxylation of glutamate to produce γ‐aminobutyrate (GABA). The nucleotide sequences of two divergent GADs (designated GAD1 and GAD3) were isolated from a Nicotianatabacum L. cv. Samsun NN leaf cDNA library. Open reading frames indicated that GAD1 encodes a polypeptide of 496 amino acids and has greater than 99% identity with known tobacco GADs, whereas GAD3 encodes a polypeptide of 491 amino acids and has about 14% divergence from known tobacco GADs. Genomic DNA analysis suggested that there are at least four tobacco GAD genes, existing in pairs of highly identical genes. An in vitro assay at pH 7.3 revealed that activities of the recombinant proteins, after isolation from Escherichia coli and partial purification by nickel‐affinity chromatography, are 57–133 times the control levels in the presence of 0.5 mM calcium and 0.2 µM bovine calmodulin.Publication Open Access A case study on identification and assessment of postharvest losses of tomato (Lycoperisicon escuentum Mill)(Postgraduate Institute of Agriculture, University of Peradeniya: Peradeniya, 1992) Rupasinghe, H. P. V; Peiris, C. N; Wijeratnam, R. S. WA study was undertaken to quantify and identify the causes of the postharvest losses of tomato during the Malta season of 1991. In the first phase of the study a suivey was earned out using random samples to collect information on the present system of posthaivest handling of tomato. Four major stages of the posthaivest marketing sequence were identified, namely; fann gate, collection agent, Manning wholesale market (Colombo) and exporter respectively. Loss assessments were conducted at these stages. Tlie survey revealed that pest and diseases such as pod borrer (Heliolhis zea) attack and blight (Altemuiia solani and Pliyiopluliora infestans) are the major contributions for posthaivest losses at the fann gate. Over maturity at hanest, bird attack and losses due to sun scorch were also obseived. Cultivating small extents of land (66% of farmers possess less than half acre) increases the liaircsting interval which resulted in a high percentage of over maturity. Tlie above factors subsequently made considerable losses at the collection agents when soiling the product for transportation. Significant losses were observed al the Manning market due to long distance of transportation with improper handling and transportation. Tlte main problem with exporters was the lack of uniformity of product with respect to maturity and size. Cumulative loss at the Manning wholesale market was obseived to be close to 54%. Contributions to the major causes of loss were as follows; mechanical damage due to over ripening 17.3%, pod borrer attack 23%, blight 4.8% and mechanical damage due to other factors 15%. Tlie cumulative loss and rejections after export quality selection was as high as 96%. Rejects due to non conformity to export specifications with respect to maturity, size and shape were 27.52% and 7.34%, respectively.Publication Embargo Catalytic graphitization in nanocast carbon monoliths by iron, cobalt and nickel nanoparticles(Pergamon, 2018-08-01) Thambiliyagodage, C. J; Ulrich, S; Araujo, P. T; Bakker, M. GHierarchically porous carbon monoliths containing metal (Fe, Co, Ni) nanoparticles were synthesized in a one-pot synthesis through a nanocasting technique using silica (SiO2) as the template. The macropore structure of SiO2 has been replicated in nanocast carbon and N2 adsorption analysis shows that the monoliths have high surface area, high mesopore volume, and that micropores are also present. The temperature effect on catalytic graphitization was studied by using x-ray diffraction (XRD), transmission electron microscope (TEM) and Raman spectroscopy. It is observed that iron was capable of producing turbostratic carbon at 500 °C, while turbostratic carbon was produced at temperatures of 700 °C when cobalt and nickel are present. Iron, cobalt, and nickel were found to be good graphitization catalysts with the order of catalytic activity being iron > cobalt > nickel. Raman spectroscopy experiments provide insight into the degree of ordering of the carbon of each sample and are in agreement with the results from the other techniques: with increasing pyrolysis temperature, with and without the presence of metals, ordering of amorphous carbon is confirmed. Detailed analysis of the Raman spectroscopic data showed clear differences between the metal catalyzed and non-catalyzed samples enabling the contributions from the two different mechanisms to be clearly distinguished.Publication Embargo Control of circadian rhythm-regulated nyctinastic movement in water lily (Nymphea stellataWilld.) flowers(Taylor & Francis Group, 2005-01-01) Samarakoon, U. C; Peiris, SFlowers of Nymphea stellata Willd., like other water lilies, are subject to circadian clock-controlled petal closure in the afternoon. To investigate the effects of plant growth regulators, and various other chemicals, in arresting nyctinastic movement (petal closure), cut flowers of N. stellata were exposed to different concentrations of gibberellic acid (GA), benzyl amino purine (BAP), naphthalene acetic acid (NAA), abscisic acid (ABA), ethanol, AgNO3, NaCl or Rinso (laundry detergent powder). The most effective treatment to control the biological clock of petal movement was keeping flowers continuously in 25 mg l–1 GA. This treatment kept flowers open, to an acceptable cut flower standard, for over 28 h. Continuous exposure to 5 mg l–1 BAP also kept flowers open to the same acceptable standard for over 15 h. Considering low-cost applications, immersing flowers in 25 g l–1 NaCl for 1 h kept them open for almost 17 h, to an acceptable cut flower standard. Immersing in 2 g l–1 Rinso (Unilever, Sri Lanka) for 1 h also kept flowers open for 14 h in an acceptable condition. By inhibiting nyctinastic closure using any of the above chemicals, N. stellata could now be considered and exploited as a cut flower.Publication Open Access Correlation between molecular diversity and biochemical traits of edible aerial parts of Basella alba L. from different geographical locations of Sri Lanka(BioMed Central Ltd, 2025-12-29) Dahanayaka, L. W.; Mapa, M. M. S. T; Kadigamuwa, C.C; Udayanga, DBackground: Basella alba L. a widely consumed green leafy vegetable, exhibits considerable nutritional and therapeutic potential attributed to its bioactive constituents. Prior investigations revealed significant variation in phytochemical and antioxidant activity across agro-climatic zones in Sri Lanka, suggesting potential genetic influence. This study is designed to explore underlying genetic variation using RAPD markers to investigate the correlations and contributions of genotype on previously reported bioactivity variation. Results: From a screening of 15 RAPD primers, four primers (OPA 9, OPA 10, OPA 16, and OPB 10) produced, polymorphic, consistent and clearly scorable banding profiles (under optimized PCR conditions) in B. alba L. collected from 15 Sri Lankan locations. These primers collectively yielded 36 bands, 35 of which were polymorphic, resulting in a high polymorphism rate of 97.2%, confirming the informativeness of the selected primers for genetic diversity analysis. Genetic similarity was assessed using Jaccard’s coefficient in NTSYSpc.v2·10e, revealing values ranging from 0.44 to 0.97, with the highest similarity from the samples from Ratnapura and Kandy and the lowest similarity in Ratnapura and Kalutara. A dendrogram constructed via UPGMA grouped the samples into two major clusters and five sub-clusters, demonstrating substantial genetic differentiation influenced by geographic origin. Cluster I included Ratnapura and Kandy, while the remaining samples formed Cluster II and its subgroups, each representing different ecological zones. When compared to the phytochemical and antioxidant clustering data of the previous study, partial correspondence was observed. A Mantel test comparing genetic diversity and biochemical/antioxidant potential revealed a weak negative correlation which was not significantly different. Some of the locations within similar genetic cluster shared similar biochemical traits, while others diverged significantly, indicating that environmental conditions also influence bioactive compound synthesis. Notably, Cluster I (Ratnapura and Kandy) showed both genetic similarity and lower antioxidant traits. Samples from Ella and Polonnaruwa showed similar bioactive traits even though they were grouped into different genetic clusters. Conclusion: These findings suggest that both genetic makeup and environmental adaptation contribute to observed biochemical diversity in B. alba L. with a clear geographical correlation. This study highlights the value of integrating molecular and biochemical analyses to develop regionally adapted B. alba L. cultivars with enhanced nutritional traits, supporting sustainable agriculture in Sri Lanka and beyond.Publication Open Access CSUP technique: a low cost sterilization method using sodium hypochlorite to replace the use of expensive equipment in micropropagation(National Science Foundation of Sri Lanka, 2012-03-28) Peiris, S; De Silva, E. D. U. D; Edussuriya, M; Attanayake, A. M. U. R. K; Peiris, B. C. NThe ability of in vitro micropropagtion to produce high quality planting material in large quantities is hindered by their high cost of production. Hence the price of planting material is high, making them unaffordable to growers. However, a larger portion of the capital and running cost of micropropagation can be reduced using CSUP (pronounced as seesap) technique, where sodium hypochlorite is used to sterilize glassware and culture media followed by culturing without using a laminar flow cabinet. This study was undertaken with the objective of evaluating the feasibility of the CSUP technique to replace the sterilization carried out using autoclaves and laminar flow cabinets. Sodium hypochlorite in four concentrations 5, 10, 15 and 20% (v/v) were used to rinse glassware and accessories prior to pouring the appropriate culture medium for anthurium cv ‘Tropical Red’ in vitro shoot multiplication. The culturing of axenic shoots was carried out inside a glass-cage and cultures were placed in the growth room. Autoclaved culture medium and a laminar flow cabinet were used in the case of the control cultures. Results revealed that the percentage of contaminationfree cultures, dry weight increase and the shoot multiplication were not significantly different between the respective treatments and the controls, as well as among treatments of different sodium hypochlorite concentrations. Therefore, the CSUP technique using 5% (v/v) sodium hypochlorite solution can be adopted to replace the use of an autoclave and the laminar flow cabinet in the major micropropagation activity of in vitro multiplication.Publication Open Access DEVELOPING WEB BASED QUALITY INFORMATION SYSTEMS FOR QUALITY IMPROVEMENT AT THE HORIZON CAMPUS(Horizon Campus, National School of Business and Management , Sri Lanka, 2017) Peiris, S; Wickramasinghe, S; Peiris, C. NQuality Information Systems (QIS) provide quality related information to stakeholders. In elearning applications, QIS should provide e-learning materials to the lecturers and the learners who use them. In Student Management Systems (SMS), QIS provide all the facilities to run the administrative functions smoothly. Electronic Research Repository (such as DSpace) enhances the quality of the institute as it reflects the research competencies of the academic staff of the institute. Horizon Campus QIS include eLearning, SMS, DSpace, Library Management System, all based on a single platform. QIS provide better service to their stakeholders anywhere, anytime effectively and efficiently. Students‘ pass rate has been increased after introducing the Learning Management System (LMS). eLearning platforms immensely facilitate the teaching and learning process as they offer an environment-friendly and efficient mechanism for ensuring learner centered teaching and learning. As QIS implemented in a Cloud based System, it is easy to maintain and run with minimal cost.Publication Open Access Development of new high yielding chilli hybrids (Capsicum annuum L.) based on heterobeltiosis and characterization of parental germplasm for DNA polymorphisms(Postgraduate Institute of Agriculture, University of Peradeniya: Peradeniya, 2006) Millawithanachchi, M. C; Perera, A. L. T; Peiris, C. N; Fonseka, H. MTwenty-eight hybrids of chilli (Capsicum annuum L.) were produced through the half Diallel genetic design using improved chilli varieties, MI 1, MI 2, KA 2, Arunalu, MI Hot, IR, Thiwari and Hot Pepper. Hybrids and parents were evaluated for yield characteristics using a 7 x 7 lattice design under the field conditions of Meewathura farm, University of Peradeniya, from June to November 2004. Performance for total yield, total number of pods, average pod weight, plant height, plant width, pod length, and dry matter percentages were significantly different among tested genotypes. High heterobeltiosis was observed for total yield, while heterosis for total number of pods, average pod weight, and dry matter percentage was low. H 42 was the best performing hybrid with 113.24% heterobeltiosis for total yield having early flowering characteristics. PCR, based on RAPD primers OPM 05 and OPM 11 gave polymorphic …Publication Open Access Development of Silica-Copper Nanocomposite for Water Purification(SLIIT, 2022-02-11) Angappan, S; Karunaratne, M; Thambiliyagodage, CWater pollution is one of the serious concerns across the world at the moment. Industrial wastewater significantly contributes to the negative impacts caused by water pollution. Textile industries discharge large amounts of effluents into water streams with little or no treatment of the discharge because wastewater treatment is an expensive process. Thus, there exists a need for a cheap and effective way to treat textile effluent that contains dyes before being discharged. A high purity silica-based Nano-adsorbent was synthesized by using rice husk as the commercially available main cheap precursor. Copper-loaded silica nanoparticles were successfully functionalized with 3-aminopropyl triethoxysilane (APTES) via the sol-gel pathway to enhance the adsorption performance of organic dyes from textile effluent. The performance of produced Nano-adsorbent was evaluated by using methylene blue as waste adsorbate. As synthesized nanomaterial was characterized by X-Ray Diffraction (XRD) and Fourier Transform Infrared (FTIR) spectroscopy, the XRD results confirmed the presence of silicon dioxide (SiO2) and paramelaconite (Cu4O3) as predicted. The FTIR confirmed the presence of Si–O stretching, N-H bending, C–H stretching, Cu–O stretching and O–H bending vibrations thereby suggesting the presence of SiO2, NH2 groups, CH2, Cu4O3 and physisorbed H2O. The optimum conditions for pH and adsorbent dosage were successfully evaluated for the adsorption process. The optimum pH at which the nanomaterial performed best was at pH 4. The optimum mass of the adsorbent that gave maximum adsorption performance was 20 mg. Kinetic studies revealed that the experimented data was in better correlation with pseudo-second-order kinetics. The outcome of this project would be of interest to textile industries looking for a cheap and effective way to treat textile wastewaterPublication Embargo Development of the major triterpenoids and oil in the fruit and seeds of neem (Azadirachta indica)(No longer published by Elsevier, 1996-09-01) JOHNSON, S; MORGAN, D. E; PEIRIS, C. NIn order to learn the best time for harvesting Neem (Azadirachta indica) seeds, the amount of the five major triterpenoids, together with the oil content have been determined throughout a fruiting season in six selected trees in Sri Lanka. The triterpenoid content and the relative proportions of the major compounds changed little from the hard green fruit stage to mature seeds, while the oil content increased markedly with time. The highest content of azadirachtin (10 mg g-1seed kernels) was recorded in newly ripened seeds. There was some loss of salannin and azadirachtin in storage after harvesting for up to 6 months.Publication Open Access Eco-friendly porous carbon materials for wastewater treatment(Springer, Singapore, 2019-08-07) Thambiliyagodage, C. J; Cooray, V. Y; Perera, I. N; Wijesekera, R. DDifferent porous carbon materials were applied to remove organic compounds and heavy metals from wastewater. Hierarchically, porous nitrogen rich monolithic carbon (HPC) was synthesized through the sol-gel synthesis method and carbonization process. Rice husk (RH), an agricultural waste material followed by carbonization at two different temperatures (RH400 and RH600) was used as the naturally generated porous carbon composite. Activated carbon (AC) was used as the control. According to the FT-IR spectra, different functional groups are present in all adsorbents. Scanning electron microscopic (SEM) images show an irregular shaped, random disordered macropore structure in RH and a robust sponge-like disordered macropore structure with ligaments in HPC. Transmission electron microscopic (TEM) images of these materials show a disordered mesopore network. Adsorption capacities of these porous carbon materials were determined for organic dyes and metal ions. Methylene blue and Methyl orange were used as the model organic compounds and Pb2+, Cu2+, Ni2+, and Cd2+ ions were selected as the metal ions. The experimental data demonstrate that the adsorption capacity of AC for Methyl orange (5.88 mg/g) is much higher than that of the alternatives (RH400–1.97 mg/g, RH600–0.69 mg/g, and HPC – 1.14 mg/g). Adsorption capacity of all the adsorbents for Methylene blue is quite similar. Adsorption capacity of RH400 for Pb2+ is much higher than that of RH600, AC and HPC. RH400 has a greater adsorption for Cu2+ and Ni2+ than the other adsorbents. All adsorbents show a low adsorption capacity for Cd2+. RH400 is a promising adsorbent for wastewater purification.Publication Open Access Economic analysis of cassava crocket manufacturing process from raw cassava roots as an initiative for waste reduction(www.foodsciencejournal.com, 2017-03) Somendrika, M. A. D; Wickramasinghe, I; Wansapala, M. A. J; Peiris, SCassava crocket is a convenient product which uses cassava root as main raw material. An economic analysis of anonymous cassava crocket processing plant was carried out to characterize inputs and outputs of the process and evaluate the profitability of production using Gross Margin and Profitability Ratio. Primary data obtained through interviewing production staff and Secondary data was used for the analysis and samples for analysis were collected using online multistage random sampling method over 60 working days. According to the results main wastes generated through the process were cassava peel, squeezed cassava liquid which were 21.5±1.3% and 20.8±1.7% of the raw cassava root weight respectively. According to the results of economic analysis the total raw material cost account for 41.3% of the total variable cost while the labour costs, transportation, rent and other costs accounted for 39.0%, 6.0%,12.5% and 1.2% respectively. From the total raw material cost the cost of Coconut oil made up the highest value which was 54% and cassava, scraped coconut, spices mix and salt made up 36%, 7%, 2% and 1% respectively. The cost and return analysis revealed the Gross margin of 360,740 LKR per year and benefit cost ratio of 1.76. This study reveals the production of cassava crocket in cottage level is profitable.Publication Embargo Effect of Co-pollutants on the Photocatalytic Activity of Fe doped ZnO Nanoparticles on the Degradation of Methylene Blue(IEEE, 2022-07-18) Thambiliyagodage, C; Lokuge, NZnO nanoparticles and Fe doped ZnO nanoparticles with varying Fe concentrations as 0.025, 0.05, 0.075, and 0.1% respective to Zn, was successfully synthesized by the sol-gel method. Synthesized nanoparticles were characterized by X-ray diffractometry (XRD) and Raman spectroscopy. As revealed by both studies Fe has successfully doped to ZnO without causing any lattice distortions. Synthesized catalysts were photocatalytically active in degrading methylene blue under sunlight. The effect of co-pollutants; Rhodamine B, Pb 2+ , PO43− and S2O32− on the rate of photodegradation was studied and it was found that Rhodamine B, Pb 2+ , and PO43− reduce the rate and S2O32− increases the rate of photodegradation.