IRSPAS 2018

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Identification and evaluation of current socio-economic conditions for improvement of water supply and sanitation in rural areas in tropical regions;A study from Sri Lanka
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Bellanthudawa, B. K. A.; Wijesinghe, L.; Darshana, W. D.; Jayasooriya, J. M. S. N.; Sundarapperuma, S. R. Y. S. S. B.; Kumara, S. D. K. S.; Nawalage, N. M. S. K.; Samaradiwakara, T. C. B.
Empowering the water supply and sanitation is a concern in Sri Lanka.Thus, present study was carried out on Anhettigama area in Deraniyagala Divisional Secretariat Division (DSD) in Kegalle District to identify the socio-economic status in the study area for implementing a water supply and sanitation improvement project and identify crucial issues to implement water supply. A semi-structured questionnaire survey was conducted for households (n=50) for assessing the social-demographic and economic background of the community through random sampling technique in project impact area. Data analysis was conducted using Microsoft Excel 2013 software to compare the responses in graphical presentations. Majority (92%) indicated that their livelihood pattern as mixed economic. 86% of the families were headed by males whereas 14% families were headed by females in the project area. Project impact area was composed of 83% Sinhalese and 17% Tamil families. In terms of water consumption patterns, 34% of houses used existing “Suhada” water supply scheme and 66% fulfilled their water requirement from private protected and unprotected wells located within their premises. Surface well water usage was 32%, which was not safe unless subjected to disinfection before drinking. 72% of the respondents mentioned that water was insufficient during dry seasons, which may reduce the water quality as well. Majority of the respondents (92%) mentioned that they were not satisfied with their present water supply scheme. Since current drinking water has not undergone any treatment method, 96% people used domestic purification methods such as artificial filtering and boiling. About 84.9% of the households had proper sanitation facilities while 9.2% of the people did not have toilets. Out of these 84.9%, 50% accounted for water sealed toilets with cistern and 34.9% accounted for water sealed toilets without cistern. Since the current water supply was insufficient, 97% people were willing to pay a monthly water bill. 16% of households received the government food subsidy of Samurdhi given for households living below the official poverty line with regards to economy. 35% of the people were involved in professions in the private sector, 26% in agriculture, 12% were government employees while unemployed population was 5%. In conclusion, there is a necessity and high demand for pipe borne water, sanitation and economic development. Incorporation of a water supply and sanitation improvement project is a sustainable solution.
Study on subsoil profile analysis at Lamae district municipality ground, Chumphon city, Thailand by atomic absorption spectroscopy for forensic application
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Moorthy, T. N.
Soil is an important physical evidence used in crime investigation. It is a trace evidence found in shoes, shirts, head hairs, vehicle tyres, transferred from the crime site. Soil is a mixture of multi-minerals, plant materials, animal matters and tiny man-made materials like paint chips, glass pieces, concrete materials, oil stains and many more. Soil is composed of small particles and these particles vary in size, shape and chemical composition. Three types of soil particles are known viz. sand, silt and clay. Soil texture is determined by the relative amounts of sand, silt and clay in the soil. The combination of soil mixture makes it distinct and thus vary from one site to another. Even the color of soil vary from one place to another since color is an indicator of the chemical and physical characteristics of soils. The metal ion concentration plays a vital role for soil comparison. Similar to top soils, subsoil samples also show variation in density, pH and metal ion concentration. Comparison of soil trace is an important component to identify and link the primary and secondary crime scenes. Therefore, forensic scientists are interested in subsoil analysis for forensic application. The objective of this research was to analyse the subsoil profiles. Three soil samples each (500 g) were collected at three different points in the same ground, viz. top soil, soil at the depth of 15 cm, and 30 cm from a total of 9 soil samples from Lamae district municipality ground, Chumphon town, Southern Thailand and preserved. The color of the soil was noted by using Munsell color chart and pH of the soil samples were identified using pH paper. Atomic Absorption Spectroscopy (AAS) was used to determine the metal ions concentration of potassium, sodium, calcium, iron, lead, copper, chromium and cadmium from soil samples collected from different points and depths. Soil samples in point S1 showed that potassium metal ion concentration at 5.72 mg/kg in top soil sample, 11. 64 mg/kg in 15 cm subsoil and 7.23 mg/kg in 30 cm subsoil and show sub profile variation at the same point. Similar variations were observed in other metal ion concentrations. The results show that no two soil samples are same and all soil samples varied both physically and chemically. Hence, it is concluded that this method of soil analysis can be used for forensic application.
Comparing the performance of randomization tests and classical non-parametric tests
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Hapuarachchi, H. T. S.; Magalle, C. H.
In the present world of data, there are plenty of instances where data does not adhere to the parametric assumptions. However, with the development of technology and computational facilities, Randomization Tests have become a popular alternative for these situations. Randomization tests also does not make any distributional assumptions but differ from classical non- parametric tests in many aspects. In this study, Wilcoxon Signed Rank test for both one sample and paired samples, Mann-Whitney test, Kruskal-Wallis test and Friedman test are being compared with respective Randomization Tests. The performance of the tests is compared for various sample sizes where 30 being the maximum sample size since the non-parametric tests are more useful when sample size is less than 30 and different variance conditions as well. The tests are compared for both skewed and symmetrically distributed data. Exponential and Gamma distributed data were generated as skewed data while Uniform and Normal distributed data are generated for symmetric data. The tests are being compared using type 1 error and power. Data were simulated using R software under each case and performed both tests for the same sample of data and obtained their type 1 error and power. Through this study, many cases were identified where randomization tests is more reliable than classical non- parametric tests in terms of type 1 error. For two skewed distributed unbalanced samples with heterogeneous variances, randomization tests are reliable since their type 1 error was around the pre-defined level while Mann-Whitey test is not reliable. Further, it could be found that randomization test is capable of protecting the type 1 error than Kruskal-Wallis test for large samples of non-normal symmetric and exponentially distributed data with heterogeneous variances. There were several situations of Friedman test performing meagerly than randomization test in terms of type 1 error. When considering the power values of the tests, randomization tests show almost equal robustness with classical non-parametric tests in most of the cases. However, for large sample sizes, randomization test has high power than Wilcoxon Signed Rank test (one sample). Moreover, when data are non-normal but symmetrically distributed, randomization test is more powerful than Kruskal-Wallis test according to the type 1 error. For symmetric data, randomization test is more powerful than Friedman test in both heterogeneous and homogenous samples. Hence, it is necessary to apply the two tests carefully as described in this study for more accurate analysis of data.
Time series modeling of red onion production in Jaffna, Sri Lanka
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Mirojan, U.; Varathan, N.; Arumairajan, S.
Onion is one of the most important commercial vegetable crops grown in Sri Lanka. Observing fluctuation of onion production is essential in the market economy. The level of the production and the fluctuation not only has a significant influence on farmers and consumers, but also a reasonable effect on the safe running of the onion in market. In this study, the annual production of red onion in Jaffna is modeled by using Box – Jenkins time series approach. The Onion production in Jaffna is cultivated in two seasons, Maha season: from September to March, Yala season: from April to August. The annual seasonal red onion production data was obtained from the office of the Deputy Provincial Director of Agriculture (Extension) during the period of 1987 to 2016. The main objective of this study is to find the suitable Auto Regressive Integrated Moving Average (ARIMA) model for the annual production of Red onion in Jaffna. Further, three statistical criteria such as Akaike’s information criteria, Bayesian information criteria, mean squared error were carried out in order to select the best ARIMA model. Through the modeling, it was identified that ARIMA (1,1,0) is the best fitting model to the given data. Moreover, the model validation has been done using the actual figures. Further, the identified best model can be used to predict the red onion production of Jaffna in near future.
Comparison study of mechanical and chemical properties of ancient and modern clay pots
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Madhuwanthi, H. M. L. U.; Katugampola, M.; Jayathilaka, K. M. D. C.; Sumathipala, H. H.
In this study, the ancient clay pottery samples from archaeological site Devalapola, Minuwangoda, Sri Lanka (3000 years, radiocarbon age) which were found by the Department of Archaeology, University of Kelaniya, were collected and compared their physical properties with modern clay pottery samples. Also to analyze the mineralogical components and the compositions, the Scanning Electron Microscopy (SEM) coupled with the Energy Dispersive X-Ray spectroscopy (EDX) analysis were performed on the both ancient and modern clay pot samples on both side and top surfaces of them. The firing clay objects is an irreversible process, which produces ceramic materials characterized by new chemical-mineralogical composition and different physical and microstructural features. Physical properties of the shards such as pottery density and water absorption capacity were analyzed. There was no significant difference in the pottery density. The values for the water absorption of the ancient clay pot samples have a wider range than the modern clay pot samples. According to the SEM results, the grain sizes of the modern clay pot samples are comparatively larger than the ancient clay pot samples. The grain sizes of the ceramic indicate the open porosity of the matrix. Based on the SEM-EDX results, SiO2 and Al2O3 were the major components of the both ancient and modern clay pot samples while CaCO3, MgO, MAD-10-Feldspar, CaSO3, Ti, and Fe are present in trace amounts. Further albite, FeS2 and KCl were only present in the modern clay pot samples. By analyzing the EDX results it can be concluded that when the production of the ancient potteries was happening, the furnace atmosphere was filled with more CO2 and the firing temperature of the ancient clay pot samples at the production was around 850 - 9000C.
Okra leaf curl disease: an emerging threat to okra cultivation in Northern Sri Lanka
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Jeyaseelan, E.C.; Sharmya, M.; Jeyaseelan, T.M.; Shaw, M.W.
Okra (Abelmoschus esculentus) is cultivated in tropical, subtropical, and warm temperate regions for its edible fruits. During the last few years okra cultivation in South Asia has been severely affected by okra yellow vein mosaic disease (OYVMD), and several research activities are conducted to find suitable control measures. However, in the last two seasons, okra plants have been affected by a new disease in northern Sri Lanka. The symptoms of the disease coincide with the description of leaf curl disease reported from India. The present study was aimed to quantify incidence of the disease and identify the causative agent associated with the disease in Northern Sri Lanka. Five districts were selected for this study, namely Jaffna, Vavuniya, Mannar, Kilinochchi, and Mullaitivu. In each district, the disease incidence was measured in three different farms affected by the disease. Symptomatic leaf samples and symptomless leaf samples from different plants were collected from each farm. Total DNA was extracted by a modified CTAB method. Polymerase chain reactions (PCR) were carried out using primers specific to begomovirus and its satellites. Leaf samples collected from okra plants grown in insect proof cages were used as control. Seeds of four different okra varieties were tested using PCR with same primers to determine whether the disease could be transmitted via seed. Symptomatic plants showed upward curling of leaves, vein thickening, twisting of the stem and lateral branches with leaves becoming thick and leathery. In the later stages of disease, plants were severely stunted with small, deformed fruit, unfit for marketing. The disease was noticed only in some newly introduced hybrid varieties. Varieties which showed high sensitivity to OYVMD, such as MI5, MI7, TV8 and Haritha, did not show leaf curl symptoms. The disease incidence ranged from 10% to 87.5%. PCR assays confirmed that the disease was associated with a complex of three different viruses: a monopartite begomovirus, betasatellite and alphasatellite. Above viruses were not detected in seeds; therefore, the viruses are unlikely to be transmitted by seeds. The present study has confirmed that some varieties of okra plants are affected by a leaf curl disease in northern Sri Lanka and the disease is associated with infection by a begomovirus and specific satellite viruses. Further studies are being carried out to identify the virus at species level based on nucleotide sequences.
Mobile solution for color blindness - An application of image processing
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Thanusanth, B.; Jeewanie, J. A.
Color blindness is a deficiency of color vision which mostly appear as a genetic problem. Due to presence of color blindness, human eye becomes unable to differentiate colors from other colors. People who suffer from the color blindness fully or partially have trouble in differentiating certain colors, but the severity of the color deficiency is varying. Sometimes damage of an eye or disorder of eye and brain are also cause to color blindness. The people suffers from color blindness wear suitable spectacles to overcome the deficiency. There are some scientific studies currently going on to address this problem. They can be classified as computer aided solutions and non-computer aided solutions. On the non-computer aided side, there is just one technique used: colored filters. These filters come in different forms such as Lenses, Glasses, etc. In the Computer aided side, there are different tools available such as Ishihara Test, Farnsworth Lantern Test. In the modern world, people always carry many smart solutions with their mobile phones in their hands and many services available to them with a single touch. For example, weather information, train time table, alerts about important meetings etc. By following a design science research methodology, this research is to study the techniques for color blindness and, implement an algorithm to detect the color ranges using Convolution matrix. The main artifacts are algorithm and mobile application. The results are twofold. On one hand, the proposed solution is very useful for those who don’t like to wear spectacles or if they forget to bring the spectacles every time. On the other hand, there are some people who are still not aware about their color blindness. For them, the mobile application can be used to identify their color blindness. Images are captured using the camera of the mobile phone and they are matched with the RGB range for colorblindness. Basically image processing techniques are used to implement the solution. The Convolution Matrix class is used to sharpening the image when mapping. This mobile application has facilities to check the different colorblindness and also a test for colorblindness. The proposed solution is validated with a sample of 25 users.
Isolation of Salmonella spp. and Shigella spp. from ground and surface water in the lower part of the Kelani river basin: evaluation of resistance against selected antibiotics
(2018) Abinaiyan, I.; Mahagamage, M.G.Y.L.; Manage, P.M.
In recent years, greater attention has been paid by national and international agencies on microbial contamination of ground and surface water sources. Antibiotics are commonly used to treat emerging infectious diseases due to anthropological activities. Improper application of antibiotics both in human and animal therapy has become the main cause of antibiotic resistance. The Kelani River Basin (KRB) is the home to more than 25% of the Sri Lankan population and it provides about 80% of the drinking water to Greater Colombo. Thus, evaluation of the microbiological status along with antibiotic resistance is important to safeguard consumers within the KRB. Therefore, twenty ground and twenty surface water samples were collected from a lower part of KRB for the study during March 2018. Water temperature, Dissolved Oxygen (DO), pH and conductivity were measured at the site itself using standard meters and N-NO3−, N-NO2−, N-NH3, Total Phosphate (TP), COD and Total Hardness (TH) were measured by following standard spectrophotometric and titrimetric methods. Total Coliform (TC) and Fecal Coliform (FC) counts were obtained from membrane filtration methods where Salmonella spp. and Shigella spp. were isolated and identified according to the WHO standard protocol. Antibiotic resistance of the isolated Salmonella spp. and Shigella spp. were obtained using Antibiotic Susceptibility Test (AST) following Agar Disk Diffusion Method (ADDM) for some selected antibiotics by commercially available AST disk. Resistant strains were subjected to Broth Microdilution Assay (BMA) to find Minimum Inhibition Concentration (MIC). All the tested general water quality parameters were within the SLSI drinking water standard except pH and COD. It was found that; out of 40 samples, 39 were contaminated with TC and FC and 39 samples exceeded the bacteriological standards given by SLSI drinking water standards. Salmonella spp. and Shigella spp. were recorded in a groundwater sample located in Pattipola where poor sanitation practices were observed. Another sampling location in Kanampella, Shigella spp. was recorded. AST results of the study revealed that the Salmonella spp. and Shigella spp. were resistant to 10 µg/disk of Amoxicillin (AMX) and Ampicillin (AMP). The BMA indicates that MICs of the isolated strains against AMX and AMP were up to 70 µg/mL. Accordingly, treatment, awareness and strategic management plan is a must to safeguard both ground and surface water consumers in the lower part of the KRB.
The impact of employer - employee relationship and practice of effective goal setting on employee performance: A study on millennial employees in small and medium scale IT organisations in Sri Lanka
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Wickramasena, R. D. G. K.; Tharaka, V. K.
This research study has been conducted to investigate the effect of two human resource management (HRM) practices on employee performance. Goal setting and maintaining robust relationship with the employees are considered to be two important factors for any organisation to achieve desired level of performance. Information Technology (IT) industry is a booming industry in Sri Lanka, and the majority of the employees who are working in Sri Lankan IT organisations are millennials. There are many studies conducted on the factors that affect the employee performance and the impact of each factor on the organisational performance. But there are no sufficient studies conducted to explore the impact of the practice of effective goal setting and employer-employee relationship on employee performance. Hence, this research investigates the effect of the practice of effective goal setting and employer-employee relationship on employee performance, in small and medium scale IT organisations in Sri Lanka. Since the higher proportion of IT workforce in Sri Lanka belongs to millennial category, this study provides thorough information for the industry, in order to achieve optimal level of employee performance. The primary data on employee performance, practice of effective goal setting and employer-employee relationship were collected through questionnaires. Out of a population of 90,000 employees, 300 employees who met the criteria have been chosen as the sample. The data analysis method used is Structural Equation Modelling (SEM) method. This study examines that there is a positive and significant influence collectively and individually of the practice of effective goal setting and employer- employee relationship on employee performance. Apart from these results, it further elaborates on the extent of the influence that practice of effective goal setting and employer-employee relationship portrays on employee performance and how the management should focus on these factors.
Evaluation of antibacterial potential of tea and different herbal plant extracts against Escherichia coli and Staphylococcus aureus
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Hansanee, K. P. N.; Yapa, P. N.
Escherichia coli is the most commonly found bacteria in the human intestinal tract. E. coli is non-pathogenic in normal conditions, but virulent strains such as Escherichia coli O157:H7 can cause gastroenteritis, urinary tract infections, neonatal meningitis etc. Staphylococcus aureus colonizes the human skin as a part of the normal flora and the most common pathogen causing bacterial infections in hospitalized patients. Further, S. aureus causes food borne infections in humans as well as pneumonia, bacteraemia, osteomyelitis, endocarditis, sepsis and toxic shock syndrome. The prevalence of methicillin resistant S. aureus (MRSA) and its ability to resist multiple drugs has posed a serious challenge for disease control. Tea is mainly an infusion of leaves of the plant Camellia sinensis consumed for centuries as a beverage and is valued for its medicinal properties. It was hypothesized that some herbal teas could also be useful in fighting against some bacteria especially enteropathogens. In the present study, C. sinensis tea leaves and plant parts frequently used in herbal tea production, were selected and their aqueous extracts were tested for antimicrobial activity against E. coli and S. aureus. C. sinensis black tea and green tea leaves, flower buds of Syzygium aromaticum, stems of Hemidesmus indicus, flowers of Senna auriculata, Aegle marmelos, plant of Aerva lanata, inner bark of Cinnamomum zeylanicum, and rhizome of Zingiber officinale were purchased from domestic markets and herbalists from Mihinthale, Kandy and Kalutara areas. They were air-dried, ground into powder and extracts were made using boiled distilled water, allow to cool at 370C and tested for its antimicrobial effect against E. coli and S. aureus, using standard agar-gel diffusion inhibition test. The test bacteria were introduced and uniformly spread on the surface of Mueller Hinton agar plates. After placing 20 μl of extracts into each well, plates were incubated at 370C for 24 hr and the diameter of the growth inhibition zone around the wells were measured. Comparisons were performed using one-way ANOVA followed by Duncan multiple-range test. Green tea was found to be most effective, followed by black tea, H. indicus and C. zeylanicum extracts, against S. aureus. The tested aqueous extracts did not show antibacterial activity against E. coli. It can be concluded that green and black teas as well as tea made by infusing specific parts of H. indicus and C. zeylanicum can be used to prevent and control diseases caused by S. aureus. Further, E. coli present in human gastrointestinal tract will not be affected by drinking the tested extracts.
Supercapacitor based novel approach for efficient solar energy harnessing
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Piyumal, P. L. A. K.; Ranaweera, A. L. A. K.; Kalingamudali, S. R. D.; Kularatna, N.
Finding greener solutions through renewable energy sources to provide energy demand in 21st century is an important task due to the shortage of world energy sources. From many types of renewable energy sources, photovoltaic cell is the most popular device that can be used to harvest solar energy and produce electricity. Currently, efficiency of conventional solar panels lies between 20-25%. In addition, part of energy is lost during the power conversion process in solar power converters. Standalone photovoltaic systems used in houses and other buildings in remote areas employ solar charge controllers to charge their battery banks in order to store energy. Efficiency of these systems relies mostly on the efficiency of in built DC-DC converter of the charge controller. With the advancement of modern semiconductor technologies and electronics, maximum of 90% efficiency can be achieved by a brand new solar charge controller. Usually this value will be decreased with the years of usage. Hence, the purpose of this work is to minimize the energy wasted during charging process of the battery bank of a standalone photovoltaic system. The initial approach was to connect DC-DC converter and battery bank in series with a capacitor charging loop. When an empty capacitor is charged by delivering Q charge using an external source, it can theoretically be shown that 50% of energy will be lost in the charging loop regardless of the resistance of the loop. If a useful resistive load is attached to the capacitor charging loop in series, this wasted energy can be effectively utilized by doing a treasured work while charging the capacitor too. In this work, this basic concept was used by replacing the conventional capacitor from a supercapacitor and attaching the DC-DC converter and the battery bank as the useful resistive load. Thereby, charging both supercapacitor and battery bank has been done. Theoretical analysis of this novel method shows promising outcomes on achieving high charging efficiency. Experimental results show this technique increases the overall charging efficiency of a standalone photovoltaic system by 9% when 80% efficient DC-DC converter is used to charge the battery bank. Therefore, it can be concluded that the overall charging efficiency of a typical standalone photovoltaic system can be enhanced by adding supercapacitor in series. The energy stored in both devices could be used to drive DC or AC loads using necessary electronics.
Improving downstream logistics performance in Sri Lankan agricultural supply chain through collaborative digital logistics
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Sarathchandra, K.; Vidanagamachchi, K.
Global agricultural production is barely sufficient to appease the hunger of the world population. Greater part of agricultural production gets spoiled on the way to the consumer. As a consequence, agricultural logistics has gained much consideration in order to ensure that the agricultural products reach the consumer with better quality. Nowadays consumers are demanding more on the food quality and the sustainability, hence the necessity of redesigning agricultural supply chain networks and implementing best practices in place is emphasized. Thus having properly managed storage facilities and vehicles, real time access to information regarding demand, supply, weather conditions and price fluctuations, proper handling of surplus and value addition is crucial. Consequently, reengineering the agricultural processes by deploying information technology has emerged. Although the use of sophisticated new digital technologies in logistics is important to enhance the performance, it is difficult for small farmers, retailers, wholesalers, etc., to invest on these new-fangled technologies. It’s proven that collaboration is a strategic decision which aids in superior supply chain performance and is a key to achieve logistical excellence. Accordingly, this study focuses on the effect of supply chain collaboration in implementing digital logistics in less sophisticated supply chains such as Sri Lankan agricultural supply chain in order to achieve high downstream logistics performance. In relation to the results of this scrutiny, digitized logistics in Sri Lankan agricultural supply chain is in the elementary stage and inadequate knowledge, skills and investments are the major restrictions for technology adoption. The methodology adopted in this research was mixed method approach which involved data collection through questionnaire surveys using stake holders of agricultural supply chain and semi-structured interviews. Quantitative analysis was conducted to discover the relationship between variables and was done through regression analysis using SPSS software and qualitative analysis was done to identify the factors affecting collaborative digital logistics and the downstream logistics performance of agricultural supply chains through thematic analysis. The study suggests to align consumer and stakeholder expectations through collaborative digitization in order to improve agricultural downstream logistics performance. The decision model and the heuristics presented through this paper will help the agricultural supply chain stakeholders in digitizing their logistics to meet consumer expectations and to maximize their profits.
Abhiram, G. and Munasinghe, R. C. (2018). Development of new master batch mixing cycle for a track producing extrusion compound with lower rejection rate
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Thennakoon, T. M. A. D. L.; Withanage, N. S.
As rubber shows inherent viscous and elastic properties, mixing of compounding ingredients is the first and most important step in rubber manufacturing. If mixing does not properly happen, many problems will be appeared in the end product leading to higher rejection. Currently, Rubber compounding industry produces track producing extrusion compounds to make continuous band of tread for military, agricultural and construction vehicles around 98% rejection, due to viscosity. Therefore, the focus of this research was to develop a new master batch mixing cycle by modifying the present conditions maintained during mastication phase, carbon black incorporation phase and dispersion phase to reduce the rejection level of track producing extrusion compound. Hence, the mastication phase rotor speed (30 rpm, 40 rpm, 50 rpm), mastication phase masticate time (60s, 80s, 100s), carbon black incorporation phase rotor speed (30 rpm, 40 rpm, 50 rpm) and dispersion phase rotor speed (30 rpm, 40 rpm, 50 rpm) were changed separately to obtain the optimum conditions for each phase giving better viscosity properties of the compound. The results revealed that, the best batches could be obtained under 50 rpm rotor speed and 80s masticate time in mastication phase; 50 rpm rotor speed in carbon black incorporation phase and 40 rpm rotor speed in dispersion phase. Therefore, the new master batch mixing cycle could be considered as 50 rpm rotor speed and 80s masticate time in mastication phase; 50 rpm rotor speed in carbon black incorporation phase and 40 rpm rotor speed in dispersion phase to reduce the present rejection rate of track producing extrusion compound TR-5237.
Impact of short term aerobic exercises on taste perception for sucrose in patients with type 2 diabetes mellitus
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Vidanage, D.; Hettiarachchi, P.; Prathapan, S.; Wasalathanthri, S.
Exercise, along with diet and medications plays an important role in the management of type 2 diabetes. Several long-term studies have demonstrated that regular exercise is beneficial in increasing insulin sensitivity in patients with type 2 diabetes mellitus. The sense of taste is an important oral chemical sense that plays a critical role in determining food preferences. The studies that have been conducted to determine the impact of exercise on taste perception is very limited. Thus, the aim of this study was to assess the impact of short-term aerobic exercise on taste perception for sucrose in type 2 diabetes mellitus patients. A sample of 140 type 2 diabetic patients, aged between 35-60 years was recruited for the study and randomly assigned into two groups, an exercise group performing aerobic exercises and a control group. A pre-tested questionnaire was used to obtain demographic data of all participants. A graded exercise protocol was introduced to the exercise group and they were instructed to perform regular exercises 4-5 days a week for 3 months without changing their regular diet and medications. Adherence to the protocol was assessed by giving regular telephone calls. Taste perception was assessed in both groups at 0 and 3 months. Preference for sucrose was assessed by the “Monell 2-series, Forced Choice Method” and suprathreshold intensity ratings for sucrose were tested using “general Labeled Magnitude Scale”. Data analysis was done by paired sample t-test and the significance was set at p=0.05 level. Participants in the exercise group showed increased supra-threshold intensity ratings for 04 out of 06 sucrose solutions, with the results being statistically significant for 02 of the higher concentrations i.e. 2.02 M (Difference in mean = 7.07 ± 4.03, p=0.032) and 0.64 M (Difference in mean = 7.77 ± 4.79, p=0.038) when compared to the controls. The preference for sucrose was significantly reduced (Difference in mean = 0.04 ± 0.02, p=0.031) after 3 months in the exercise group. The supra-threshold intensity ratings in the control group did not show a statistically significant pattern while the preference for sucrose was increased (Difference in mean = 0.1 ± 1.04, p=0.479). In conclusion, taste sensitivity for sucrose increases especially for higher concentrations and taste preference decreases in type 2 diabetes mellitus patients after 3 months of regular aerobic exercise.
Estimating carbon footprint: Case study of University of Kelaniya
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Bandara, W. A. R. T. W.; Theekshana, I. K. P. R.; Tharaka, T.; Ketethenna, K. V. L. M.
According to GHG protocol, in 2011 Sri Lanka emitted 45 million metric tons of carbon dioxide equivalent (MtCO2e). In order to identify the organizational impact on carbon dioxide emission leading to global warming, an analysis was carried out using planned CO2 inventory for the University of Kelaniya, with setting Dalugama premises as organizational and operational boundary. Estimates were limited for the scope 1 and scope 2 emissions. Reporting period is for 12 months and ideally corresponding with 2016 financial year since this allows easier comparison of financial performance with other aspects of carbon footprint analysis. The four main faculties namely Faculties of Science, Social Science, Finance and Management Studies and Humanities were considered. As activity data, monthly water bills and electricity bills of year 2016 were gathered. Total consumption of fuel used in transportation from internal vehicle pool was collected for the year 2016 from the Transport Division of University of Kelaniya. Further information was collected to understand the, “Exact mode of transportation, type of vehicles (engines) used” and, “how often transport is used”. Total consumption of fugitive fuels for air conditioner and refrigerator refilling were also collected for the year 2016. In addition, amount of diesel used in diesel generator to produce electricity for the year was considered. After the collection of data direct and indirect carbon footprint was calculated separately using guidelines given in the DEFRA data base. Conversion factors widely accepted are used in conversion of electricity, water, transportation into CO2e. Emissions of other greenhouse gases were converted into equivalent emissions data in MtCO2e, using the global warming potential factors published by DEFRA. According to the analysis, the total carbon emission of the University of Kelaniya, Dalugama premises under scope 1 and 2 was 42,383.8 tons CO2e in year 2016. To calculate the per capita carbon footprint, the total carbon footprint was divided by the number of the permanent staff considered in this case study. The per capita carbon footprint by considering scope 1 and 2 was 4.7093 tons CO2e during 2016 at University of Kelaniya.
Effect of feeding herbal enriched Artemia on the growth performance and stress resistance of guppy fry (Poecilia reticulata)
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Sandamali, L.; Kumudu, R.; Sajani, R.M.
Artemia is one of the commonly used live-feed in hatchery production in aquaculture industry. The nutrient composition of Artemia can be enhanced by bioencapsulation using various sources. The present study was conducted to evaluate the growth performance and stress resistance of guppy fry (Poecilia reticulata) fed on Artemia enriched with different herbal ingredients ie: green kankung (Ipomoea aquatica) or carrot (Daucus carota). Herbal ingredients were mixed with oil to make the enrichment solution and ІІ instar stage of Artemia (36 hr after hatching) was used for the enrichment. Two days old guppy fry was fed with unenriched Artemia (UE), Artemia enriched with carrot juice (CJ) or Artemia enriched with kankung powder (KP) for 21 days and the growth, survival and stress resistance of fry were evaluated. These comparisons were tested using one-way ANOVA. After a feeding trial of 21 days, the total length was significantly higher in fry in CJ treatment (14.59 ± 0.84 mm) followed by fry in KP treatment (13.83 ± 0.16 mm) and fry in UE treatment (12.14 ± 0.83 mm). Fry fed on CJ and KP enriched Artemia showed higher mean final weight (0.0279 ± 0.0048 g, 0.0263 ± 0.0012 g) and % Specific Growth Rate (SGR) (6.98 ± 0.063, 6.39 ± 0.99) respectively compared to the fry fed on unenriched Artemia (0.0167 ± 0.009 g, 4.64 ± 0.064 g). Fry in all treatments showed 100% survival rate by the end of the experiment period (21 days) and were subjected to stress resistance test. Cumulative Mortality Index (CMI) for salinity stress test was significantly different in the three treatments. Highest CMI (960) value, therefore lower salinity resistance was observed in the fry fed with KP enriched Artemia, and the lowest CMI (0) value and the highest salinity resistance was observed in fry in CJ treatment group. Further fry in CJ (CMI 400) and KP (CMI 320) treatments showed higher thermal resistance compared to fry in UE treatment (CMI 720). The present study reveals that Artemia enrichment using carrot juice can be used to enhance growth and stress resistance of guppy fry in aquarium condition.
Optimal parameter values for Respondent-Driven Sampling
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Kularathna, N. J.; Ramanayake, K. P. A.
Respondent Driven Sampling (RDS) is a new link tracing sampling technique which is used to collect data from hard to reach or hidden populations such as sex workers, HIV infected people, homeless people, etc. In RDS, individuals recruit other individuals through their social networks. The major benefit of RDS among other link tracing methods is that it achieves a probabilistic sample with known selection probabilities. Deciding on the number of seeds, coupons and waves are crucial prior to implementing a RDS study. However, since there are no universally accepted values for these parameters in RDS, they need to be determined based on the study. This research focused on finding optimal number of seeds, coupons and waves that give the highest level of accuracy for RDS estimates when all the parameters are free to change simultaneously. A publicly available partial dataset from Project 90, Colorado Spring study was used as the population. The simulation study used the most frequently used sets of values for the number of seeds, coupons and waves based on literature. As a result, 125 combinations of seeds, coupons and waves were formed and for each such combination, 1000 resamples were drawn from the population. The successive sampling estimator was used in this study to estimate the population parameters as it has been shown that it substantively outperforms all other estimators in RDS. The simulation results revealed that the estimated values converge to the true parameter value as the number of seeds and the number of waves increase and when the number of coupons decrease (up to 2). Once the sample size and the number of seeds have been determined, the proposed simulation process can be used to find the optimal number of coupons which gives the highest accuracy for any considered population characteristic.
Screening of selected invasive plant extracts for antifungal activity against Colletotrichum gloeosporioides
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Karunarathna, T.C.M.F.; Damunupola, J.W.; Bandara, B. M. R.
High-quality ornamental plant products are needed for export-scale floriculture. A major barrier to provide high quality products is the wide prevalence of plant pathogenic diseases. Colletotrichum gloeosporioides causes diseases in several species of ornamental plants. Use of chemical fungicides can cause undesirable non-target effects and fungal resistance. The invasive plants that threat natural ecosystems, may serve as an inexpensive source for developing antifungal products that are devoid of the problems associated with synthetic fungicides. We examined the antifungal activity of 36 extracts (6 plants x 2 plant parts x 3 extract solvents) of 6 invasive plants, Mikania micrantha, Tithonia diversifolia, Lantana camara, Clusia rosea, Chromolaena odorata and Clidemia hirta against the pathogenic fungus C. gloeosporioides that was isolated from Dracaena reflexa leaf spots. PCR and sequencing for molecular characterization of the fungus was done at Genetech, Colombo. All the invasive plants were collected from the Central Province, Sri Lanka. Plants were washed, air-dried and powdered. Each powder was sequentially extracted into n-hexane, dichloromethane (DCM) and methanol at room temperature (RT) for 30 min using an ultrasonicator (40 kHz). Removal of solvents on a rotary evaporator gave the respective plant extracts. Each plant extract (2 mg/disc) was screened for antifungal activity against C . gloeosporioides using disc diffusion method by incubating for 3-5 days at RT . Standard fungicides mancozeb and propineb (50 µg/disc) served as positive controls. All assays were carried out in triplicate and repeated thrice in completely randomized design. The areas of inhibition were measured and analyzed using one-way ANOVA with Minitab 16 . The extracts of M . micrantha, T . diversifolia, C . odorata, L . camara and C . hirta showed varying degrees of antifungal activity against C . gloeosporioides while the extracts of C . rosea were inactive. The DCM leaf extract of M . micrantha (3.42 ± 0.34 cm2) and the DCM root extract of T . diversifolia (2.26 ± 0.24 cm2) displayed the highest area of inhibition; while mancozeb and propineb were 2.17 ± 0.14 and 1.29 ± 0.06 cm2, respectively. M . micrantha leaves and T . diversifolia roots could be potential sources for developing plant-based fungicides to be used in floriculture industry.
Investigation of some water quality parameters in the ground water of East and Central regions of Valigamam Zone in Jaffna Peninsula
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Navaranjan, S.; Prabagar, S.; Rajapaksha, H. G. N.; Prabagar, J.
Jaffna peninsula relies on ground water for their entire domestic and agricultural needs due to less rainfall and not any other fresh water resources. In recent years many complaints have been received indicating that ground water is unsuitable for human consumption. Increased levels of certain ions such as calcium, nitrate in water deteriorate the quality of water and can cause serious health issues such as kidney diseases and blue baby syndrome. Thirty two water samples from domestic and agriculture wells were collected randomly from East and Central regions of Valigamam zone in Jaffna peninsula. The water quality parameters such as total dissolved solids, alkalinity, potassium, phosphate, sulfate, nitrate, calcium and magnesium were evaluated from December 2017 to March 2018. Phosphate, nitrate and sulfate were determined by multiparameter photometer using powder pillows, calcium and magnesium were determined by titration methods, total dissolved solids were determined by multiparameter and potassium by flame photometer. The results obtained were compared with the Sri Lankan standards for potable water – SLS 614:2013. It was found that about 62.5% of samples exceeded the standards (500 mg/L) in total dissolved solids. Alkalinity content of all the samples exceeded the Sri Lankan standards (400 mg/L). Sulfate content was higher in 12.5% samples compared to standard (250 mg/L). Manipay, Kopay and Inuvil areas showed high concentration in most of the ions compared to standards. These are the areas where agriculture was practiced throughout the year. High amount of calcium in ground water was observed in areas such as Kopay and Urumpirai. Calcium ions in water samples varied from 63.2 to 246.4 mg/L which shows an increase by about four fold within 16 years compared to studies in 2001. Elevated levels of nitrate content were found in Inuvil, Uduvil and some places in Kopay. A survey conducted among the farmers has shown that application of fertilizers in those areas were high. The nitrate content varied from 2.7 to 199.5 mg/L. 37.5% samples showed higher content of nitrate than the permissible level (50 mg/L) making them unsuitable for drinking purposes. The pH values of the water samples were within the range of 6.8 to 10.39 indicating slight alkalinity. The phosphate level varies from 0.18 to 3 mg/L in Kopay and 0.12 to 2.4 mg/L in Kondavil area. Compared to a study in 2013, the phosphate levels have increased in the study areas by three folds. The present study suggests that water quality of groundwater in Valigamam zone has increased in the levels of nitrate, phosphates, sulfate and calcium. Agriculture practices impact on the water quality parameters and use of fertilizers in agriculture should be minimized in Valigamam area.
Optimization of monoplex and multiplex PCR assays to detect meat species and adulteration of meat products in the Sri Lankan market
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Kothalawala, S. D.; Karaliyadda, S.; Fernando, A. L.; Karaliyadda, M.; De Silva, V.
Meat identification testing, detecting intentional adulteration of meat and detecting meat contamination due to poor processing practices are essential to ensure good quality of meat products. Incidence of meat adulteration, product mislabelling, commercially motivated adulteration and contamination of meat products with undesired or forbidden meat species have been reported in some countries. In Sri Lanka, religious and cultural views are one of the primary determinants of choice of meat consumed. Therefore, the necessity for a rapid, sensitive reliable and reasonably cost effective assay that can determine the quality of meat products is high. Even though this need exists, no such reachable methods are currently available to the Sri Lankan meat producers to determine and certify the quality of their products. PCR based DNA methods are the gold standard in food species identification due to its less time consumption, specificity and sensitivity. The present study optimized monoplex and multiplex PCR assays to detect the meat species and to detect any adulterants or contaminants present in meat products. DNA was isolated by high salt TNES extraction method, from samples of raw meat and processed meat obtained from retail outlets in Colombo. The isolated DNA was amplified using PCR which demonstrated the specificity of the adopted primers to each species of raw meat. Mixtures of meat DNA were then subjected to optimized multiplex PCR; chicken-pork and beef-pork assays to detect each of the types of meat present in the mixture. Processed products of chicken (5) and beef samples (5) were subjected to these optimized multiplexes. The assay was found to be effective in determining the species of meat present in meat products containing chicken, beef and pork, clearly demonstrating species specific bands of 266 bp, 271 bp and 149 bp respectively. These PCR assays are useful in detecting main products and the contamination at the same time with reliable accuracy and specificity which can fulfil the requirement of quality testing of meat products that is important for the consumer, the meat industry and organizations that have an interest in food safety and quality. It is also economical and has wider applicability since many species can be detected with one assay. Compared to other available methods which sometimes fail to be effective when used on highly processed samples, PCR can be applied efficiently. Therefore, it is presented as a suitable assay for identification of meat species and for the detection of adulterants and contaminants in processed meat samples.