ICAPS-2021

Permanent URI for this collectionhttp://repository.kln.ac.lk/handle/123456789/23880

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Allelopathic effects of Prosopis juliflora (Sw.) Dc. on selected crops and native plants
(Faculty of Science, University of Kelaniya, Sri Lanka., 2021) Jayasinghe, J. A. C. P.; Ratnayake, R. M. C. S.
Allelopathic effects of exotic plant species in natural and agricultural ecosystems have received increasing attention because of their negative impacts on native plant growth and reduction of crops yields. It was hypothesized that leaf extracts of P. juliflora have allelochemicals that could inhibit seed germination and seedling growth of the selected plants. The objective of the study was to investigate the allelopathic effects of the Prosopis juliflora leaves on seed germination and seedling growth of selected crops (Eleusine coracana, Vigna radiata) and native plants (Manilkara hexandra, Calophyllum inophyllum). The stock extract (100 gL-1) was preparedfrom P. juliflora leaves collected from Bundala National Park after five days of digestion in deionized water. The stock solution was used to prepare dilution series for applications (10.0 gL-1, 25.0 gL- 1, 50.0 gL-1, and 75.0 gL -1). The above concentrations of P. juliflora leaf extracts were separately tested for percentage seed germination, shoot lengths, root lengths, and seedling growth of the selected plant species with distilled water as the control. Seed germination percentages, root lengths, and shoot lengths results of the test species were analyzed using One-way ANOVA followed by Tukey’s test at p=005. The findings indicate that with the increasing concentration of P. juliflora leaf extracts, seed germination and seedling growth of E. coracana, V. radiata were significantly reduced. The negative effects were more visible in E. coracana than V. radiata. The lowest germination percentage of E. coracana (0.0 %) was observed when seeds were treated with 100 gL-1 and 75 gL-1 and C. inophyllum seeds were also not germinated in those concentrations. Manilkara hexandra seeds were not germinated in all concentrations of P. juliflora leaf extracts. Allelopathy was concentration-dependent and with increasing concentration of P. juliflora leaf extract, seed germination and seedling growth of C. inophyllum significantly reduced (One-way Anova, p=0.05). Hence it showed that Prosopis juliflora aqueous leaf extracts have an allelopathic effects on the seed germination and seedling growth of the selected crops and the native plants. Therefore, allelopathic effects of the aqueous leaf extracts P. juliflora need to consider in forest management and agriculture.
Analysis of biogenic amines in grave soil and cadaver dog training aids using gas chromatography mass spectrometry
(Faculty of Science, University of Kelaniya, Sri Lanka, 2021) Perera, U. D. N. T.; Wisor, M. R.
In a forensic investigation of a missing persons or a suspected murder, finding human remains plays a vital role. Currently, the most common method to find these remains is the use of human remains detection dogs or HRD dogs. Although, these dogs can distinguish human remains from animal remains, and find human remains buried in significant depths, the scientific basis for this remarkable ability is not well understood. HRD dog’s ability to detect human remains depends on the volatile organic compounds (VOCs) produced during the decomposition process. These VOCs contribute to the “smell of death” and the analysis of them is crucial to understand the differences between human and animal decomposition odor. Additionally, some HRD dogs are trained using cadaver dog training aids known as “pseudo corpse” due to the limited availability of decomposing human remains for training purposes. In some studies, these training aids are found to be less effective compared to real human remains. Although biogenic amines like putrescine and cadaverine are present in grave soil and decomposition odor, the presence of these compounds in decomposition odor is not well reported in literature. In previous work researchers have used gas chromatography mass spectrometry (GC-MS) in decomposition odor analysis. These amines often have high basicity, high polarity, and low volatility compared to other VOCs, and they tend to absorb and decompose in the GC column, sample vessels, and injection system making them hard to detect in low concentrations and difficult to analyze using GC-MS. To obviate these problems, the current work focuses on analyzing these amines by derivatizing them followed by the analysis using GCMS. Furthermore, an extraction method is developed to extract amines from soil samples. Three derivatization agents trifluoroacytalacetone (FAA), pentafluoroproponic anhydride (PFPA) and, isobutyl chloroformate (IBCF) were investigated and IBCF showed promising results. This method was used to analyze grave soil samples collected near to a partially decomposed human body and a relatively fresh human body and three commercially available cadaver dog training aids. Cadaverine and putrescine were present in one of the cadaver dog training aids at concentrations of 780. ± 6 mg/mL and 1440. ± 6 mg/mL respectively. Only cadaverine was present in the second training aid at a concentration of 426 ± 6 mg/mL. One training aid did not contain any amines in detectable levels. Soil obtained near the partially decomposed corpse showed a slightly elevated amount of cadaverine at a concentration of 37 ± 1 mg/g compared to the body that was recently placed which contained 31 ± 1 mg/g of cadaverine. Future work of this research involves the analysis of amines in grave soil during different stages of decomposition.
An analysis of the technical efficiency of protected agriculture in dry zone area of Sri Lanka
(Faculty of Science, University of Kelaniya, Sri Lanka, 2021) Wickramasinghe, H. M. K.; Dissanayaka, D. M. P. V.
Efficiency is an important factor in productivity growth. It helps in utilizing scarce resources in an effective manner to derive efficient consumption. Identifying the determinants of efficiency levels is a major task in efficiency analysis. Vegetable Production is the most essential sector of the Sri Lankan economy, but recently the seasonality of production supplemented by the climate change effects has posed a major threat to maintaining a constant year-round vegetable production. Protected Agriculture (PA) is identified as one of the best adaptation methods to increase the productivity of horticultural crops, particularly vegetables. The resources that affect the inefficiency in protected agriculture has contributed to such variations in the productivity across the dry zone area. Technical Efficiency (TE) is used as an indicator to determine whether the output reached at its optimal level in production. Both technical and socio-economic factors may result the inefficiency. On the other hand, if it is possible to identify the characteristics of efficient farmers and inefficient farmers, it would be helpful to improve the efficiency of protected agriculture production. Therefore, the attempt of this thesis is to first estimate the technical efficiency in PA based on the factors which derive efficiency of Protected farming and thereby, investigate the influence of socioeconomic factors of farmers on the efficiency in the dry zone. In comparison to the wet and intermediate zones, the dry zone has the highest vegetable production area in the country with sample resources and there are more protected agriculture farmers in the dry zone area. Therefore, the research study was done using all PA farmers in dry zone area. The data set was gathered from the HARTI and consists of 70 farmers' data from the year 2017, taking into account the population of the dry zone area's geographic location. The stochastic frontier approach has been used to generate technical efficiency estimates using Frontier 4.1 by Coeili (1994). The results of this thesis show that the estimated mean technical efficiency of PA production is 49.64 %. Therefore, there is a 50.36 % scope for increasing technical efficiency in PA by using the present technology. The elasticity of inputs is computed from the estimated Cobb- Douglas production function. A production function is a mathematical expression that describes how the quantity of output changes as a function of the inputs utilized in the process. Which concludes, total labor, total Fertilizer, unit price, access to extension service, and initial cost are statistically significant at 5 percent. This implies that the variables of significance remain an important contribution to the determination of technical efficiency in protected farming in the dry zone areas. The analysis reveals that the sum of the partial output elasticity with respect to all inputs is 159, which indicates an increasing return to scale in PA production. Future, it has been found that age, gender, education, and farm size are statistically significant determinants of technical efficiency. The result of the study indicates that the current use of all production inputs is not at the optimum level. Thus, the study provides guidance in increasing the technical efficiency in Protected agriculture in the dry zone in Sri Lanka.
An analysis on the optimization of the upper convective zone thickness to minimize the surface heat loss of a model salinity gradient pond
(Faculty of Science, University of Kelaniya, Sri Lanka, 2021) Jayatissa, N.W. K.; Perera, P. A. A.; Attalage, R. A.
Solar energy is a renewable energy source that provides enough energy to keep the natural cycles alive. Sri Lanka is a country near the equator that has abundant sunlight throughout the year. Solar ponds are a proven technology for storing thermal energy at low temperatures. In general, a solar pond consists of three layers: the upper convective zone (UCZ), the middle non-convective zone (NCZ) and the lower convective zone (LCZ). Part of the incident solar radiation passes through the UCZ and NCZ and is trapped in the LCZ. Unlike the other two layers, the top layer of the pond is directly exposed to the environment. The energy flows associated with the UCZ and their impact on the LCZ were the focus of this experimental study. The solar pond described in the present work is constructed in the premises of the University of Kelaniya, Sri Lanka (Latitude 6.97 N, Longitude 79.91 E). The pond has a surface area of 6 m2 (3 m  2 m) and a depth 1.5 m. The bottom of the pond and the walls are properly insulated to reduce energy loss through the walls and bottom. Since the UCZ is exposed to the environment, heat is lost from this area through convection, evaporation and radiation. The average UCZ temperature of the solar pond varies from 27.3 oC to 31.5 oC depending on the month of the year. This study shows that the total energy loss (radiation, convection and evaporation) of the upper surface varies between 11 Wm-2 and 57 Wm-2. The convective heat transfer coefficient is directly related to the average wind speed, and in this study the wind effect is minimal because the water surface is blocked by the perimeter walls. Therefore, the wind effect is neglected in the energy calculations. The radiant heat loss is estimated to be about 40% of the total energy, assuming an emissivity of 0.83 for water. Since the wind effect was negligible in this study, the estimated evaporative heat loss is about 10% of the total energy. Depending on the solar insolation, energy from the NCZ and the total losses associated with the UCZ determine the heat storage of the UCZ. The easily adjustable parameter of an established solar pond is the thickness of the UCZ. A thicker UCZ can hold more incident solar insolation inside and this causes high temperature values in the zone. High temperature values in the UCZ minimize the conduction of heat transfer from the LCZ to the UCZ, while decreasing surface heat loss by convection and radiation. However, this process reduces the amount of solar radiation entering the LCZ. When the thickness of the UCZ layer was increased from 5 cm to 10 cm, the energy absorption increased from 42% to 47%. Similarly, increasing the thickness to 20 cm, resulted in an additional 6% increase. Therefore, ultimately it affects the LCZ heat storage. On the other hand, reducing the thickness of the UCZ decreases its temperature and allows more insolation to reach the bottom of the pond. Therefore, it is important to optimize the thickness of the UCZ and the results suggested that a thickness in the range 2 to 8 cm is optimal for the operation of the pond.
An anthropometric index to estimate the obesity
(Faculty of Science, University of Kelaniya, Sri Lanka, 2021) Tissera, H. A. N. S.; Munasinghe, M. A. H. C.; Dissanayaka, D. M. P. V.
Obesity is a disease that occurs when the percentage of body fat has a negative effect on a person’s health. As for the World Health Organization's definition, obesity is defined as the condition of the body when the body fat is greater than 25% and 35% for men and women respectively. Obesity is a crucial point to discuss as it has been considered a major nutritional health problem in developed and developing countries. Therefore, many indices have been developed to estimate body fat using various measurements of the body. The objective of this study was to develop a simple anthropometric linear equation (index) that is more accurate than the Body Mass Index (BMI) and other indices which currently use to estimate whole-body fat percentage among individuals. Developing a new index to measure body fat is significant as the current indices fail to measure body fat accurately in some exceptional cases like professional athletes. As for an example, the BMI also does not capture information on the mass of fat in different body parts. Hence developing a new index to measure the body fat level is essential. This study used secondary data from the National Health and Nutrition Examination Survey (NHANES) in 2017- 2018. Missing values were imputed by using the multiple imputation techniques. Initially a descriptive analysis was performed to analyze the composition of the sample. It was discovered that the mean fat percentage was 35.416 with a standard deviation of 7.109 and 24.461 with a standard deviation of 7.964 in girls and boys of age 15 to 19 years, respectively. Total fat percentage was considered as the response variable. Simple linear regression models were fitted to find the most correlated variables with the total body fat level. 15 anthropometric indices were generated using transformations on explanatory variables. The best-fitted equation was selected by considering the High Correlation with body fat, Minimum Akaike Information Criterion (AIC), and Highest R2 value. The accuracy of the index was tested using the test dataset and compared with the accuracy of the current indices. It was revealed that this index measures body fat more accurately than the Body Mass Index (BMI) and Waist-Height Ratio (WHR) with an accuracy of 76.8%. Waist Circumference, Hip Circumference and height measurements used to develop new index. Then the selected variables were used with the age category and gender as explanatory variables to perform a multiple linear regression model to find the determinants of the body fat level. As a further study, the developed index can be improved by adjusting for gender-wise and age-wise to obtain more accurate results.
Anthurium disease detector using machine learning techniques
(Faculty of Science, University of Kelaniya, Sri Lanka, 2021) Ranasinghe, K. M. N. S.; Liyanage, U. P.
There are many problems with planting Anthurium due to diseases. The lack of knowledge about the diseases and identification of the disease correctly, are the major challenges that face by the farmers. Further, some of diseases have no cure, yet must be destroyed before they can be spread. The ways and means of obtaining the essential assistance, for example may be from responsible parties such as Department of Floriculture or Agriculture in Sri Lanka, are limited due to the fact that there is no flexible mechanism to approach their resource personals in efficient manner. Thus, treatment of ill plans becomes hard problem. To overcome these practical difficulties faced by farmers, this study focus to build a mobile application using Android Studio Software to detect the disease through image processing and computer aided models, and thereby, allows farmers to apply disease treatment steps as soon as possible. Using the mobile application, farmers allows to take pictures of disease plant parts, and send for disease detection programs. These programs analyses the images using appropriate machine learning techniques and gives a feedback concerning the disease the plant has. Indeed, correct identification of the plant disease leads to early treatment, and hence the better curing possibilities. The system allows to determine diseases using the images of the Anthurium leaves, flower body, flower nose and the roots of the plants. The system allows to recognize three diseases namely, Bacteria Blight, Rhizoctonia Root Rot and Black Nose Disease. To determine disease correctly, images from all the above mention plant parts are needed. As the disease detection techniques, algorithms using the Convolutional Neural Network (CNN) have been utilized. In particularly, a sequential CNN model namely, LeNet, have been trained and tested using 2962 images. Further, all the images are transformed to gray-scale images to improve the classification rate of CNN algorithms. The models are trained with 10,15,20,30,40,50,75,80 and 100 epochs, and the scenario with 80 epochs performed best in terms of both accuracy and loss values and had the best curve. Based on the image set that has been used, Bacteria Blight, Rhizoctonia Root Rot and Black Nose Disease have been detected with the accuracy of 96.5%, 99% and 98%, respectively. The predicted time is on average less than one second using average computer power utilized in the back end of the system. This accuracy is sufficient for successfully detecting the plant diseases, and thereby, the system that has been engineered will be beneficial for the farmers to manage healthy plant nursery.
Antibacterial activity of Flueggea leucopyrus Willd
(Faculty of Science, University of Kelaniya, Sri Lanka, 2021) Karunarathne, E. D. C.; Lokuwalpola, D. V.; Sandaruwan, K. P. A. M.; Dabarera, M. D.; Wanigasekara, D. N.
Fluggea leucopyrus Willd. (Euphorbiacea) known as ‘Katupila’ in local dialect is a plant widely used in indigenous medicinal system in Sri Lanka as a remedy for cancers and infectious diseases. Sufficient scientific investigations however are unavailable to rationalize the ethnobotanical and ethnopharmacological significance of the plant. Present study was conducted to investigate the antimicrobial potential of F. leucopyrus whole plant extract. The antimicrobial activity of the methanolic extract of F. leucopyrus was determined by agar well diffusion method. The extract was tested against five standard bacterial strains and eight clinically isolated bacterial cultures; Staphylococcus aureus (ATCC 25923), Staphylococcus aureus (ATCC 6538), Escherichiacoli (ATCC 8739), Pseudomonas aeruginosa (ATCC 9027), Pseudomonas aeruginosa (ATCC 27853), Streptococcus pyogenes, Klebsiella pneumoniae, Proteus mirabilis, Enterococcus faecalis, Salmonella typhi, Bacillus subtilis, Methicillin Resistant Staphylococcus aureus (MRSA) and Staphylococcus saprophyticus. The test was triplicated for each microorganism. Ciprofloxacin was used as the positive control while 20% Dimethyl sulfoxide (DMSO) which was used to dissolve the plant extract was used as the negative control. No inhibition of growth was observed in the negative controls and the positive control was able to inhibit the growth of all test bacterial strains used. The growth of S. pyogenes, K. pneumoniae, S. typhi, B. subtilis, E.coli (ATCC 8739) was not affected by F. leucopyrus extract, meanwhile S. aureus (ATCC 25923), S. aureus (ATCC 6538), P. mirabilis, E. faecalis, MRSA, P. aeruginosa (ATCC 9027), P. aeruginosa (ATCC 27853) and S. saprophyticus seemed to be susceptible to the extract showing inhibition zone diameters of 12.67±0.58 mm, 12.67±0.58 mm, 15.33±0.58 mm, 9.67±0.58 mm, 13.67±0.58 mm, 12.67±0.58 mm, 11.33±0.58 mm and 13.67±0.58 mm respectively. These preliminary observations suggest that F. leucopyrus plant is a potent source of antimicrobial substances. Further studies are required to determine the phytochemicals responsible for the antimicrobial action.
Antimicrobial activity of selected plant extracts against Salmonella typhi and Escherichia coli and their phytochemical screening
(Faculty of Science, University of Kelaniya, Sri Lanka., 2021) Wijekoon, W. M. A. N.; Gayathri, S. M. D. S.; Dias, P. G. I.; Anuradha, N. G. D.; Kananke, T. C.; Athnayaka, R. M. K. T.; Perera, M. G. A. N.; Sabaragamuwa, R. S.; Wickramaratne, M. N.; Rathnayaka, R. M. U. S. K.
Salmonella typhi and Escherichia coli are foodborne pathogens that cause food poisoning, various infections, and sepsis. Emergence of microbial resistance to currently available antibiotics creates a notable curiosity to find novel antibacterial drugs or complementary medicines. Olax zeylanica L. (Mella), Phyllanthus debilis (Ela pitawakka), Osbeckia octandra (Heen bowitiya) and Artocarpus heterophyllus (Kos) leaves are edible remedies used by local villagers. All four plants are abundantly utilized in ayurvedic medicine against different ailments. This study aims to evaluate the antimicrobial activity and screen the phytochemicals in these plant leaves. Initially, methanol and ethanol leaf extracts were prepared and then they were concentrated using the rotary evaporator. Antibacterial activity of the plant extracts (10 mg/ml) against S. typhi and E. coli was evaluated using the well diffusion method (40 µl/well) in Mueller Hinton agar and replicated thrice. Positive (Ciprofloxacin) and negative controls (ethanol and methanol) were also tested. The size of the microbial inoculum was adjusted to the cell count of 6.0 ×108 CFU/ml, approximately using the McFarland standard. Preliminary phytochemical screening was conducted for flavonoids, saponins, steroids, tannins, and terpenoids using standard techniques. Statistical analysis was conducted using two-way ANOVA and Fisher LSD method. The highest average diameter of the inhibitory zone against E. coli was recorded for the methanol extract of O. zeylanica (0.94 ± 0.02 mm) while the lowest was for A. heterophyllus ethanol extract (0.68 ± 0.02 mm). The methanol extract of P. debilis showed the highest average diameter of the inhibitory zone (1.79 ± 0.08 mm) against S. typhi while O. zeylanica ethanol extract showed the lowest diameter (0.59 ± 0.03 mm). The diameters were significantly different (P<0.05) among the four plants and different extract types of the same plant. Tannin was detected in O. octandra, A. heterophyllus and P. debilis. Saponin was detected only in O. zeylanica. Terpenoids were detected in all other plants except in P. debilis. Further analysis with more advance tests is needed to confirm the presence and quantity of phytochemicals with higher accuracy. Since all plants exhibited antibacterial activities, identification of the specific chemical compounds responsible is important for synthesizing plant-based antimicrobials.
Antioxidant activity and protein precipitating ability of peel extract of Nephelium lappaceum Linn. (Rambutan)
(Faculty of Science, University of Kelaniya, Sri Lanka, 2021) Binuwangi, A. K. D. M.; Rajapakse, C. S. K.
Nephelium lappaceum Linn. (Rambutan) peels, one of the tropical agricultural wastes, have been identified as a rich source of polyphenols with antioxidant properties. Plant phenolic compounds can interact with protein molecules and the polyphenol-protein complexes enhance the antioxidant capacity of polyphenols and therefore influences the bioaccessibility of phenolics. This study was aimed to determine the antioxidant activity and the bovine serum albumin (BSA) protein precipitating ability of peel extract of Rambutan (Nephelium lappaceum). Fresh Rambutan fruits of Malwana special variety were collected from a commercial cultivation in the Western province, Sri Lanka. Chemical constituents in dried, powdered Rambutan peels were extracted using cold extraction (extracting solvents = methanol, ethanol, and ethyl acetate) (6 days, 37° C) and methanolic soxhlet extraction (6 hrs, 60 °C) separately. Antioxidant activity and total phenolic content (TPC) of freeze-dried extracts were determined using 1,1-diphenyl-2-picryl-hydrazyl (DPPH) free radical scavenging assay and Folin-Ciocalteu assay, respectively. The correlation between antioxidant activity and TPC was analyzed using Pearson’s correlation. Since the methanolic crude extract obtained from cold extraction was rich in phenolics, it was fractionated into hexane, dichloromethane (DCM), ethylacetate, and aqueous methanol, and their protein precipitation ability was determined using Bradford assay. Among the crude extracts, the highest percentage yield was obtained from soxhlet extraction (34.5 %). Methanolic cold extract had the highest TPC (332.56 ± 1.20 mg GAE / g of extract), and ethylacetate crude extract had the lowest TPC (210.13 ± 3.20 mg GAE / g of extract). Further, antioxidant activity of soxhlet extract (IC50 = 9.70 ± 0.50 µg/mL) and methanol (IC50 = 8.20 ± 0.35 µg/mL) and ethanol (IC50 = 8.31 ± 0.50 µg/mL) cold extract was significantly higher (p < 0.05) than that of synthetic antioxidant BHT (IC50=13.92 ± 1.19 µg/mL). Statistically significant (p < 0.01), a strong positive correlation was observed between DPPH radical scavenging activity and the TPC with Pearson’s correlation coefficient (r) of 0.99. Hence, the results suggested a potential for the utilization of peels N. lappaceum, as a nutraceutical enriched with natural antioxidants. According to results of protein precipitation potential of fractions, the highest percentage of BSA precipitate was observed (88.54 ± 0.92 %) in the ethyl acetate fraction. Thus, this study identified that Rambutan peel polyphenols have an affinity to bind with BSA at pH 4.5 in-vitro and the antioxidant activity of Rambutan peel extract would be masked by polyphenol–protein precipitation to some extent. Therefore, further studies should be necessary to isolate, purify, and identify polyphenols in Rambutan peels with their protein precipitation potentials to understand the mechanism of phenolic-protein interactions and their industrial applications.
Applicability of modified queueing model with encouraged arrivals for economic recession
(Faculty of Science, University of Kelaniya, Sri Lanka., 2021) Dinushan, J. A. S.; Walgampaya, C. K.
Businesses often offer lucrative deals and discounts so that customers’ encouragement to engage with those firms are developed. This kind of arrivals are termed as encouraged arrivals. As a pandemic is overwhelming the world, it could be suggested that, for upbringing of declining businesses, this concept, now, deserves to be taken into account more than ever in the past. In order to describe the encouraged arrival process mathematically, a Markovian queuing model is used and the parameter that represents the arrival rate is modified with percentage increase in the arrival rate of customers. In this paper, we investigate the behavior of measures of performances with and without encouraged arrivals for multi-server finite capacity queuing system. In the analysis it was possible to identify that a significant number of customers compared to the normal arrival process is engaged with the system when it is affiliated with the encouraged arrival process. As well as it shows that customers engage more and more with the system irrespective of the high rates of arrivals and low rates of services. In addition to that under the economic analysis, it was uncovered that the profit increment due to encouraged arrivals is very higher than that due to normal arrivals.
Application of cleaner production technique in small scale tea industry in Sri Lanka
(Faculty of Science, University of Kelaniya, Sri Lanka., 2021) Rasangi, A.G. D.; Jayasena, D. M.
This study explored the cleaner production techniques that can be used in the small and medium- scale tea sector in Sri Lanka. Sustainability of the sector has become a big question due to persisting climate change, socioeconomic changes, unstable financial positions, and the lack of knowledge of modern technology. This paper investigates the possibility of adopting Cleaner Production (CP) practices in the small and medium-sized tea industry from the land preparation stage to the manufacturing stage along with the tea supply chain. The paper reviewed the material and energy flow analysis of the Sri Lankan tea industry in order to identify CP opportunities and make recommendations to minimize negative environmental impacts. Data were collected from small-scale (less than 0.8 ha) tea farmers, transporters/drivers involved in tea leaf transportation, and small and medium scale (SME) factories in the southern Province of Sri Lanka. The sample consists of 100 farmers, 60 tea transporters and 5 SME factories. To gather data from farmers and transporters, questionnaires were used. Interviews also were conducted and observations were made to gather information from selected factories. The results show that the monthly average raw tea leaf yield per hectare was 1233 kg. Further, to produce 1 kg of black tea, generally, 4.5 kg of fresh tea leaves, less than 20 mins. of human energy, and 0.89 kWh of energy (electricity) is required. Besides, an average of 819.5 kg of chemical fertilizers is used per ha per year. Results indicate that opportunities are available to adopt five cleaner production options to reduce the environmental footprint of small-scale tea industry of Sri Lanka. They include growing tea with seeds instead of vegetatively propagated basket tea plants, using machines to pluck tea, automate movement of tea from withering to rolling section, improve knowledge of tea cultivators on more effective cultivation and caring techniques , ensure worker safety and opportunities to acquire better skills relevant to tea industry, introducing mechanisms to improve the link between raw leaf suppliers and the factory, introduce environmentally friendly inputs such as organic fertilizer and recycled organic waste and water and use of biodegradable material instead of polythene. These measures may contribute to optimize material energy and water usage by small and medium scale sector and therefore to environmental sustainability,
An approximate solution to Lane-Emden equation of the polytrophic index three by using Differential Transform Method
(Faculty of Science, University of Kelaniya, Sri Lanka, 2021) Aththanayaka, A. M. S. K.; Wimaladharma, N. A. S. N.
Lane-Emden equation is a second order dimensionless non-linear ordinary differential equation which can be used to describe internal structure of a star, the thermal behaviour of a spherical cloud of gas, isothermal gas spheres etc. Self-gravitating spheres of plasma, such as stars, can also be described approximately by using these equations. Lane-Emden equation was solved by using Adomian Decomposition Method (ADM), Homotopy Analysis Method for some values of polytrophic index n. There are exact, analytical solutions for Lane-Emden equation in particular values n = 0, 1, 5. Since its non-linearity, the exact solutions cannot be found easily. Differential Transform Method (DTM) is an iterative method with a Taylor series solution gives good approximation in very small region. DTM can be applied for both linear and nonlinear nth derivative functions. In this research, a numerical solution to Lane-Emden equation with n = 3 has been found by using Differential Transform Method. To increase the range of convergence of the solution, the Pade approximation has been applied. Pade approximation is a ratio of two McLaurin’s expansion of the polynomials. The obtained solution for Lane-Emden equation has been compared with the solutions obtained by using the Fourth Order Runga-Kutta (RK4) method, ODE45 and Forward Euler method, which are effective and accurate methods for solving differential equations. The Einstein-Maxwell equations for a static spherical distribution of matter which is called Electrically Counterpoised Dust (ECD) under gravitational attraction and electrical repulsion can be simplified to the Lane-Emden equation when n = 3. It has been shown that the mass of a sphere of electrically counterpoised dust is an increasing function of its radius and it has a maximum value. Since the solution obtained gives us a physically acceptable result, it can be justified that the obtained solution using DTM is acceptable and gives better approximate solution with the form of a polynomial for linear and nonlinear differential equations.
Arsenic contamination in Sri Lankan traditional rice varieties in Anuradhapura district and probabilistic assessment of human health risk through rice consumption
(Faculty of Science, University of Kelaniya, Sri Lanka, 2021) Senarathne, E. M. N. S.; Edirisinghe, E. M. R. K. B.
Arsenic (As) is one of major hazardous carcinogen found in foods and identified as a significant public health concern. Diet and lifestyle of Sri Lankans are mainly relied on rice. Nowadays high demand for traditional rice can be distinguished in the market. The study was aimed to determine the As contamination in Sri Lankan traditional rice varieties and to assess the adverse health effect on human through consumption of these varieties. Twenty four rice varieties were collected from local farmers, Anuradhapura district in the North Central province of Sri Lanka. Rice samples were taken without husks and dry weights were considered. Digestion procedure was carried out using microwave digestion system prior to the analysis. Total As levels were detected using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Results were verified using a certified reference material (NMIJ 7503b) with 98% recovery. As concentration detected between 39.92 (± 0.10) µg/kg to 543.00 (± 3.10) µg/kg and maximum level was reported in Rathdel while Kuruluthuda showed the lowest concentration. Ten rice varieties including Madathawalu (265.75 ± 4.34) µg/kg , Dik Wee (257.73 ± 2.90) µg/kg, Goda Heenati (249.88 ± 0.50) µg/kg, Rathu Heenati (238.65 ± 3.40) µg/kg, Kiri Murunga (268.04 ± 14.96) µg/kg, Hondaruwal (204.09 ± 6.52) µg/kg, Gurusinghe Wee (251.91 ± 6.03) µg/kg, Gonabaru (274.86 ± 2.50) µg/kg, Al Wee (284.71 ± 7.90) µg/kg and Rathdel (543.40 ± 3.10) µg/kg exceeded the maximum allowable concentration of As in rice (200 µg/kg). There was a significant difference between As amount of Rathdel with that of all the other varieties (P<0.005). Health risk assessment was performed based on the Estimated Daily Intake (EDI) and Hazard Quotient (HQ). EDI for all the rice varieties were within the tolerable daily intake reference limit for As. Noncarcinogenic risk of As was evaluated by HQ value and it was increased in the order, Al Wee < Bada Heenati < Beheth Heenati < Dahanala < Dik Wee < Duru Wee < Goda Heenati < Gonabaru < Gurusinghe Wee < Handiran < Hondaruwal < Kalu Heenati < Kalu Murunga < Kiri Murunga < Kiri Naran < Kurulu Thuda < Madathawalu < Marjuana < Pushparaga < Rath Suwandel < Rathdel < Rathu Heenati < Sudu Heenati < Suwandel. However, all the HQ values were lower than 1 indicating no carcinogenic health risk. Even though ten varieties exceeded the maximum allowable limit, overall health risk assessment confirmed that the consumers are safe to consume rice of these native varieties.
Assessing knowledge, attitude and practices towards household e-waste management: A case study of householders in Gampaha district, Sri Lanka
(Faculty of Science, University of Kelaniya, Sri Lanka., 2021) Athukorala, A. S. T.; Jothirathne, P. A. A. U.
This study aimed to assess the knowledge, attitude and practices of householders towards e-waste management in Gampaha District. Due to the current economic status and high rate of urbanization, Gampaha District was selected to study and it was based on a quantitative approach. Primary data were collected through pre-tested a structured questionnaire. Then, 400 questionnaires were distributed among households and the response rate was 85%. Mobile phones, desktop computers, laptops, cameras, and other electronic appliances were the types of e-waste considered in this study. The analysis demonstrated that 71.1% of respondents were aware of e-waste although 51.3% did not receive proper education on e-waste. 93.2% of the participants were not aware of government rules and regulations on e-waste and 81.4% did not know the e- waste collection centers in their area. 96.2% of householders tend to change their electronic devices and move into new devices due to damages. 22% of householders store their waste electronic and electrical equipment at home and the rest of the people dispose of them by exchanging them for new devices (15%), dumping (10%), sell to recyclers (17%), donate (5%), sell to individuals (16%), discard with household waste (7%) and burning (8%). Furthermore, the knowledge score of the participants was calculated using the eight questions about knowledge, the score of zero was given for incorrect answers and one was given for correct answers. Hence, the maximum Knowledge score was eight. A score less than 3 was considered poor, 3-5 moderate and above 6 was good. Results revealed that 48.38% of the respondents have good knowledge about e-waste. “The continuous increase in e-waste is a problem for Sri Lanka”, “Everyone is responsible for the e-waste at their home”, “I refrain from buying new device as long as they can use the old one”, “They need to be aware of the materials in the electronics they use”, “I would like to provide e-waste to the equipment manufacturer free of charge for eco-friendly recycling” and “If the cost of recycling is included in the cost of production, I would like to pay more for the equipment” were the six questions used to evaluate the attitude of the householders towards e- waste management and those were considered as indicators to assess attitude. The attitude score was assessed by applying a four-level Likert scale (strongly disagree-disagree-agree-strongly agree) such that the minimum score was 4 and the maximum score was 24. The average of an individual’s total score is considered for the categorization of the attitude level. It disclosed the necessity to change the attitudes of the household members over the e-waste management activities. Hence, the findings provide valuable insights for the government and for the responsible authorities on the requirement of installing effective steps to promote knowledge and attitude level of the citizen about the household e-waste management activities and socio- demographic based promotional and training activities will be more productive. Furthermore, results indicate that respondents dispose their e-waste using unsustainable practices and hence cause damages to the environment.
Assessing the suitability of treatments for successful karyotyping of selected Phalaenopsis cultivars
(Faculty of Science, University of Kelaniya, Sri Lanka, 2021) Thathsarani, Y. K. D. D.; Senanayake, R. A. S. P.
Orchidaceae is considered as one of the largest flowering plant families and has acquired the attention of researchers in different aspects i.e., taxonomy, phylogeny, phytogeography, etc. In the family Orchidaceae, the genus Phalaenopsis has been attracted the eye of the global floriculture industry due to its specific commercial traits. Therefore, this genus has obtained a significant proportion of the global market as both pot plants and cut flowers. Hence, it is important to develop hybrids with specific commercial traits to meet the demand. Generally, the gene-trait interaction is the key point of the development of hybrids. Consequently, it is important to understand the chromosome morphology and the correlation between the chromosomes and the floral characteristics. Therefore, karyotyping based on modern and classical cytogenetic approaches in Phalaenopsis cultivars would reveal significant information associated with gene- trait interaction. However, the knowledge gap in chromosome characters of Phalaenopsis cultivars has hindered the development of quality improved cultivars with attractive traits. Therefore, it is important to infer the relationships of karyotypes with the chromosome characteristics and the ploidy levels of selected commercially valuable Phalaenopsis cultivars grown in Sri Lanka. Furthermore, it is important to assess the suitability of treatments for successful karyotyping. In this study, potted plants and tissue cultured specimens of four Phalaenopsis cultivars were selected, based on consumer demand. Tissue cultured specimens were obtained from the Floriculture Research Center, University of Kelaniya. The squashing method with 2 mM 8-hydroxyquinoline pretreatment at 3 different temperatures (16 C, 18 C and 20 C) for 4 hours was used in chromosome preparation at mitotic division stages of the root tip cells. Both Feulgen staining and aceto-orcein staining were used as staining protocols in chromosome spread preparation. In chromosome spread preparation, tissue cultured specimens performed better than the specimens of potted plants. Pretreatment with 2 mM 8- hydroxyquinoline at 18 C followed by aceto-orcein staining was successful for tissue cultured white Phalaenopsis cultivar in obtaining chromosome spreads at mitotic metaphase. Hence, pretreatment of tissue cultured plants with 2 mM 8-hydroxyquinoline at 18 C and aceto-orcein staining can be suggested as suitable treatments for successful karyotyping of white Phalaenopsis cultivars.
Atmospheric chemical composition of bulk precipitation of the vicinity of oil refinery in Sapugaskanda, Sri Lanka
(Faculty of Science, University of Kelaniya, Sri Lanka, 2021) Karunarathna, M. M. S. T.; Deeyamulla, M. P.; Kannangara, A. T.
Rainwater quality is critical because it can be used to forecast air quality. The aim of the current study was to investigate the chemical characteristics of bulk precipitation in Kelaniya, Sapugaskanda, and Siyambalape, an area close to an oil refinery in Gampaha District, one of Sri Lanka's most densely populated and urbanized districts. Wet precipitation samples were analyzed for pH, conductivity, Na+, K+, Mg2+, Ca2+, F-, Cl-, NO3-, SO42-, Pb, Cu, Mn, Al, Zn, Ni, Cr, Cd, and Fe for a total of 18 samples between 2020 July and 2020 October. The results obtained were compared with 6 samples taken from a background area situated in Kidelpitiya, Meegoda where the anthropogenic influence is minimum. Volume-weighted average concentrations of the major ionic species present in precipitation samples were in the order of F−< K+< NO3−< Mg2+< Cl−< SO42−< Ca2+< Na+. Neutralization of the acidic species would take place due to the presence of MgCO3 and CaCO3. Other than the anthropogenic sources natural sources were also considered. When considering a marine contribution, SO42−/Na+, Ca2+/Na+, and Mg2+/Na+ ratios are higher than the reference value suggesting that contribution of sources be possible other than marine. When considering a soil contribution, SO42−/Ca2+, NO3−/Ca2+, Na+/Ca2+, and Cl- /Ca2+ ratios are higher than the reference value suggesting that contribution of sources be possible other than soil. It was also found that Al is the most predominant trace element in the area while Fe is the least (All are in metallic forms not in the ionic forms). Investigation of correlation between major ionic species and elements (Ca2+, SO42-, Al, Cu, Zn, and NO3-) in the wet precipitation samples identified probable anthropogenic sources such as heavy traffic, biomass burning, large-scale constructions, and waste incineration. The highest correlation between Na+ and Cl- is probably due to marine contribution. A comparison between the background and the study area was carried out to identify the difference between the chemical compositions of the atmosphere during the given period suggesting that the area has a higher chemical composition of the species interested rather than the background. Also, this study reveals the effect of the Covid-19 pandemic on the reduction of the chemical composition of such species of the atmosphere in the area of interest. This study reveals that the chemical composition in the atmosphere is strongly dependent on both anthropogenic and natural phenomena around the area of study.
Automatic fashion recommendation system
(Faculty of Science, University of Kelaniya, Sri Lanka., 2021) Panduwawala, P. K. P. G.; Silva, M. T. De
The fashion industry has a clear opportunity to act differently, pursuing profit and growth. The female fashion industry is one of the industries that quickly changes. By using social media, an idea about the changes and the new trends in the female fashion industry can be taken. The findings of this study contribute to a better understanding of the fashion industry by providing current trends in clothing types and colors. It allows the fashion industry's garments to guide the industry in times of need, resulting in a better trend for the industry. To provide a solution for the female fashion industry to gain an understanding of the trend of clothing types and colors in female fashion. The proposed platform has been implemented using techniques such as web scraping and Convolutional Neural Networks (CNN). In the proposed solution, first, download the images from INSTAGRAM using web scrapping. After that, the female images were filtered by applying a CNN using the Keras library. Then cloth type and cloth color are predicted by two different CNN algorithms. The system presents the predicted result using Graphical User Interface (GUI).Using that can give quick results of the changes in the female industry using this platform. According to the findings, the percentages of accuracy were recorded as 82.0% for female image filtering, 83.2% for clothing type in the fashion industry, and 80.2% for clothing color prediction respectively. The predictions were made in less than 0.5s, hence the proposed system is useful for providing instant changes to female fashion trends to the fashion industry with high accuracy. With the results of this study, It can be concluded that the developed model provides a reliable and accurate platform to gauge multiple gradients of current trends in the female fashion industry based on the Sri Lankan actresses' images on Instagram.
Avian diversity in some human-altered landscapes in the Gampaha district, Sri Lanka
(Faculty of Science, University of Kelaniya, Sri Lanka., 2021) Liyanage, M. P.; Chandrasekara, W. U.
Although diversity and distribution of avifauna have been mostly studied in and around undisturbed and protected areas in Sri Lanka, there is a dearth of studies in human-altered landscapes. The present study, therefore, was carried out to investigate the variation of avifaunal diversity in some human-altered landscapes viz garbage dump site (Manelgama village), town area (Kiribathgoda town), coconut cultivation (Gonahena village), paddy field (Weboda village), rubber cultivation (Embaraluwa village), and a fish landing site and market (Negombo town) in the Gampaha district in Sri Lanka. Birds present at each selected landscape were identified and counted following the fixed-radius point count method (n=4 each) between 0700 hrs – 0800 hrs from August 2020 to March 2021. The degree of landscape alteration of each site was measured in terms of the number of buildings, tall trees (5m<), fruit trees, power line posts, TV antennas/disks and sound level concurrent to bird counting. The species richness (SR), species heterogeneity (H’) and species evenness (J) of the avifaunal communities in each landscape were calculated. Data on the avifaunal abundance and the degree of landscape alteration were analysed using ANOVA and PCA as appropriate. Altogether, a total of 1126 bird counts were recorded, and the birds belonged into 26 different species. Although characterized by low avian heterogeneity and low species richness, the total abundance of birds was high at highly altered landscapes viz garbage dumpsite (n=566; SR=9; H’=1.23), fish market (n=276; SR=8; H’=0.90), and the town area (n=119; SR=5; H’=0.96). The house crow (Corvus splendens), intermediate egret (Mesophoyx intermedia) and the rock pigeon (Columba livia) dominated the six sites with the relative abundances of 33.04%, 28.69% and 18.65%, respectively. It was also found that the abundance of these three bird species were significantly high in the above highly altered landscapes (p<0.05). In contrast, the paddy field recorded the highest H’ (2.5), SR (16) and the J (0.90) values. The H’, J and the SR of the avian communities were also found to be negatively correlated with the degree of habitat alterations in a way that the avifaunal diversity measures decreased with the increasing habitat alterations by anthropogenic activities. Further, the more tolerant and generalist avian feeders such as house crow, intermediate egret, and rock pigeon can be regarded as bio-indicator species in human-altered landscapes.
Bacteriological analysis of egg based-Kottu rotti in selected eateries in Kesbewa, Colombo, Sri Lanka
(Faculty of Science, University of Kelaniya, Sri Lanka, 2021) Wewagama, M. M. P. M. K.; Gunasena, G. D. D. K.
Bioaccumulation potential of tributyltin in mollusks in some harbours in Sri Lanka
(Faculty of Science, University of Kelaniya, Sri Lanka, 2021) Bandara, K. R.V.; Manage, P. M.
The Organotin compound Tributyltin (TBT) is widely used as an antifouling agent in ship paints, and is considered to be one of the strongest neurotoxic xenobiotic substances in the marine environment. It has been widely recognized that exposure to TBT causes the development of male characteristics known as ‘imposex’, in female mollusks. The present study was aimed to assess if there is a potential of accumulating TBT in the lipid containing body tissues in some mollukan species namely Crassostrea madrasensis, Crassostrea cucullate, Perna viridis, Pernaperna and Thais clavigera inhabiting the Colombo, Dikkowita, Galle, Mirissa, Dewundara, Kirinda, Hambanthota and Trincomalee harbours in Sri Lanka. The TBT concentration (ng kg-1) and the lipid content (%) in lipid containing body tissues were determined in the above species (n=6). The highest concentration of TBT was recorded in P. viridis (234±3 ng kg-1) collected from the Dikkowita harbour, while the TBT concentration of this species ranged from 42±0.9 - 226±2.3 ng kg-1 in the remaining seven harbours. The TBT concentration was also high in four other molluskan species namely C. madrasensis (74±3.7 -181±4.1 ng kg-1), P. perna (35±2.4- 126±6.7 ng kg-1), C. cucullate (12±8.1- 116±6.5 ng kg-1) and T. clavigera (32±1.9 -134±2.3 ng kg-1). The mean TBT concentration and the lipid content showed a significant positive correlation (P<0.005). Further, the TBT concentrations were found to be the highest in mollusks that had the highest lipid content in their body tissues: C. madrasensis (P=0.004), C. cucullate (P=0.02), P. viridis (P=0.003), P. perna (P=0.001) and T. clavigera (P=0.001). The highest TBT concentration and the lipid content were found both in P. viridis and T. clavigera. The results suggest that the bioaccumulation of TBT was high in the molluskan species that had the highest lipid content in their body tissues. There is a threat to the molluskan biodiversity in these harbours as a result of TBT exposure and bioaccumulation in the fat tissues.