Research Symposium-2016

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Browsing Research Symposium-2016 by Author "Alakolanga, A.G.A.W."

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    Antifungal Activity of Endophytic Fungal Species Isolated from Apple (Malus domestica)
    (Uva Wellassa University of Sri Lanka, 2016) Naseefa, M.A.; Alakolanga, A.G.A.W.
    Novel natural metabolites with a microbial origin are one of the most interested areas in Natural Product Chemistry. This study was aimed to investigate the antifungal activity of endophytic fungal species isolated from apple (Malus domestica). Endophytes, which have a microbial origin, reside inside tissue without causing apparent disease to host. Fresh apple samples from local supermarket, Badulla, were first surface sterilized to limit epiphytic fungi. Potato Dextrose Agar (PDA), supplemented with chloramphenicol (100 mg mL-I) was used to isolate a Penicilium sp. and a Chrysosporium sp. at pH 5.6. Isolated endophytes were cultured in potato dextrose broth for 14 days and extracted with hexane and ethyl acetate successively. Diluted (10 %) diethyl sulfoxide was used to prepare solutions of extracts and inhibition of fungal growth was determined using disc diffusion method at five different concentrations (1000, 2000, 3000, 4000 and 5000 ppm) against Alternaria sp. and Aspergillus sp. with 100 mg mL-1 flucanazole as positive control. Effective concentrations (EC,,, and EC90) were calculated for mean inhibition percentage. Aspergillus sp. growth was highly inhibited compared to Alternaria sp. by Penicllium extract. EtOAc extract of Penicllium showed high inhibition against (Minimum Inhibitory Concentration < 1000 ppm) Alternaria sp. than Crysosporium extracts (MIC 4572.2 ppm). Brine Srimp Lethality Assay (BSLA) was also carried out with 48h old naupali. Results were noted after 24 h. Penicllium sp. extract showed a high lethal toxicity (LC50 402.078 ppm) as they may produce excess of metabolites than Crysosporium sp. The observation of different antifungal activity of the two types of endophytic fungal extracts revealed the variations in chances and rates of producing secondary metabolites. With these results, it can be concluded that, apple endophytic fungal extracts can be used to control selected phytopathogenic fungal species, but the toxicity of extracts should be considered in case of food commodity. Keywords: Endophytic fungi, Fungal extract, Bioactivities, Malus domestica, Antifungal compounds
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    Determination of Factors Affecting to the Hardness of the Compound Used for Apex of Bead of Industrial Pneumatic Tyre
    (Uva Wellassa University of Sri Lanka, 2016) Dharmathilaka, W.S.S.; Alakolanga, A.G.A.W.; Arachche, P. K.W.; Weerawansha, A.N.R.
    The market for industrial pneumatic tyres created a demand for high hardness compounds for bead filler (apex) and sidewall support applications to increase the performance and load bearing capacity of the tyre. A number of different approaches have been used to increase the hardness of bead filler compounds. To obtain additional hardness for the bead filler compound phenolic reinforcing resins are used and mixing conditions are changed. The study was conducted to find out the factors affecting to the hardness of bead filler compound and identified their appropriate values. As well as verified those factors by performing the experiments. Through that hardness was improved to the expected limit. Effect of dumping temperature and maturation time and the interaction between maturation time and dumping temperature were checked. For that intermediate mixing was done under three different dumping temperatures and kept under three different maturation time. Obtained results were analyzed using two factor factorial analysis. There is no significant effect of dumping temperature and maturation time and also the interaction between dumping temperature and the maturation time. But highest mean hardness values are given by 18hrs of maturation time and 110 ° C dumping temperature. As the second experiment HMT incorporation stage has been changed. Generally HMT is incorporated in to 2" stage mixing but here it was incorporated in to intermediate mixing stage. Previously founded maturation time (18 hrs) and dumping temperature (110 °C) were used for the 2" experiment. Two sample t-test was applied to analyze obtained data. According to the analysis, there was a significant effect of HMT incorporation stage for the hardness of bead filler compound. It is concluded that if there is not a significant effect of dumping temperature and maturation time there is a considerable effect of dumping temperature and maturation time for the hardness. Keywords: Bead filler, Dumping temperature, Maturation time, intermediate mixing, 2" stage mixing
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    Determination of Factors Affecting to the Tensile Strength of Tread Compound of Pneumatic Rubber Tyre Used in Industrial Application
    (Uva Wellassa University of Sri Lanka, 2016) Herath, H.M.L.P.; Alakolanga, A.G.A.W.; Wickramaarchchi, P.K.; Weerawansha, A.N.R.
    There are many factors which affect the tensile strength ofpneumatic tyre tread compound. In this experiment, it is focused on mixing process parameters which affect to the tensile strength. The mixing parameters were investigated on an intermesh mixer for selected tyre tread compound. It was identified that the dumping temperature, mastication time, carbon black and silica incorporation temperature and carbon black silica feeding sequence influence the tensile strength of particular compound. The study was conducted to find out the effect of above factors to the tensile strength of tread compound and to identify their appropriate value. For that 1' stage mixing was done under three different dumping temperatures (155 °C, 160 °C, 165 °C) and three different mastication times (0 s, 20 s, 40 s) using the best combination of mastication time and dumping temperature changed carbon black silica incorporation temperature (120 °C, 140 °C) and carbon silica feeding sequence. According to the two factor factorial analysis dumping temperature significantly affect to the tensile strength. Experimental results showed that higher and lower dumping temperatures retard the strength but moderate temperature of 160 °C is the optimum. Mastication time also affect to the tensile strength but not significantly. Considering the interaction between mastication time and dumping temperature, we can conclude that it significantly affects to the tensile strength. Best combination of those factors is 40 s and 160 °C. Carbon black and silica dispersion also influence to the tensile strength of tread compound. A minimum temperature of 140 °C is necessary to gain efficient reaction between silica and silane. Feeding silica and carbon black separately avoids the restriction ofcarbon black against silica - silane reaction. Keywords: Tread compound, Tensile strength, Dumping temperature, Mastication time, Carbon black
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    Determination of the Effect of Water Quality on the Sensory Properties of Tea Liquor
    (Uva Wellassa University of Sri Lanka, 2016) Ruwanpura, R.N.D.S.; Alakolanga, A.G.A.W.; Wanniarachchi, M.
    Tea is an aromatic beverage which is demanded by consumers because of its unique taste, color and aroma also known as sensory properties of tea liquor which are influenced by several factors. The major ingredient of beverage tea is water and therefore water used to brew tea can be on sensory properties. This study was therefore, conducted to find out whether there is an effect of water quality on tea liquor properties by analysing most important water quality parameters to develop a profile of suitable water for brewing of tea comprised with optimum ranges of these water quality parameters. In this view, ten water samples were obtained from ten DS divisions of each Matara, Colombo, Ratnapura, Puttalam, Anuradhapra and Kandy districts were analyzed. This study was conducted in two steps; a sensory evaluation of teas of DUST 1 grade prepared with different water was conducted by trained panellists and a water analysis to determine the pH, Total hardness, total alkalinity, phenolphthalein alkalinity, EC andTDS. Results of water analysis showed, values for all the selected water quality parameters within districts as well as among districts were varied significantly. Therefore, it is evident that the water quality in terms of these parameters is varied within a district as well as among districts substantially. Average ranks obtained from sensory evaluation data varied pertainingto thearea hence, concluded that the area used to obtain water for brewing of tea has a significant effect on the sensory properties of tea liquor.Teas prepared from the water obtained from Deniyaya, Devinuwara, Mulatiyana, Rathnapura, Godakawela, Pelmadulla,Moratuwa, Kotte, Thimbirigasyaya, Kesbewa, Nattandiya, Dankotuwa, Rajanganaya, Thalawa, Mihinthale, Ganga IhalaKorale, Panwila, Yatinuwaraareas showed highest average ranks hence can be concluded as good in quality. Results shows a negative relationship between total hardness, electrical conductivity and total dissolved solids contents of water and tea liquor properties, yet the relationship between pH and total alkalinity parameters with tea liquor properties is insignificant. Results of the study concludes, liquor properties of tea are affected by water quality in terms of water hardness, conductivity and total dissolved solids. Approximately, total hardness of25-218 ppm, electrical conductivity of 5.45-861.1s/ cm and total dissolved solids of 3.27-51.6 ppm ranges are preferable for brewing of tea. Keywords: Water quality, Tea liquor Properties, Water quality parameters
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    Development of a Simple and an Economical Method for Extraction of Edible Crude Fish Oil from Catla catla
    (Uva Wellassa University of Sri Lanka, 2016) Dahanayaka, D.R.C.; Alakolanga, A.G.A.W.; Abeyrathne, E.D.N.S.
    Fish oil is a rich source of nutrition and it provides benefits on human health. It is considered to be an important natural source of polyunsaturated fatty acids (PUFA).When considering of existing edible fish oil extraction methods, several draw backs can be identified. The objective of this study was to develop a simple, rapid, cheap, nontoxic and scale up method to extract edible crude fish oil from Catla catla. In the present study, preliminary investigations were conducted to determine the suitable solvent for fish oil extraction. According to that ethanol, acetone, propanol and hexane were selected for sequential solvent extraction since they were recommended as the food grade solvents. The results of the sequential solvent extraction showed acetone and ethanol have an excellent capacity to extract fish oil. According to yield study, separated crude lipids, high yield was resulted from 50% acetone (p < 0.05). Therefore fish skin was treated with five volumes of 50% (v/v) acetone and homogenized. The homogenate samples were kept in refrigerator at 4°C for 24 hours. Then samples were filtered through filter paper and solvents were removed through dialysis, and separated lipids were freeze dried. In the present study, physicochemical properties were obtained as iodine value (131.13 ± 7.33), peroxide value (15.53 ± 0.38) and free fatty acid value (4.48 ± 0.22) in final extracted fish oil and it was in the acceptable range. According to the results, the extracted oil has good quality and high stability. Therefore, this method is considered as simple, rapid, cheap and non-toxic. This can also be incorporated to solvent extraction of fish oil from fish which can be scaled up. Keywords: Catla calla, Ethanol, Acetone, Lipids, Nontoxic
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    Development of a Simple and Economical Method for Chitin Extraction from Prawn (Penaeus monodon) Shell Waste
    (Uva Wellassa University of Sri Lanka, 2016) Wehella, M.N.; Alakolanga, A.G.A.W.; Abeyrathne, E.D.N. S.
    Chitin is the second most important biopolymer on earth and found mainly in invertebrates and several other organisms. It exhibits a wide range of applications in biotechnology, medicine, agriculture, food processing, environmental protection and textile industry. Disposal of shell waste is a major problem in relevant processing plants. Objective of this research was to develop a simple, economical, high yielding, non-toxic and cost effective method for chitin extraction from prawn (Penaeus monodon) shell waste. Samples were collected from a local prawn processing plant and crude chitin was obtained through deproteinization, decolourization and demineralization using NaOH, butanol and citric acid respectively. Crude chitin was then converted in to chitosan by deacetylation. Purity analysis, yield analysis, physiochemical and functional properties analysis such as moisture content, Water Binding Capacity (WBC), Fat Binding Capacity (FBC) and Ce chelating activity were measured. Control was prepared using 5% (w/v) NaOH, 100% (vlv) Acetone and 1% (vlv) HC1 solution. FBC and WBC of the present study showed significantly higher values (539.20 ± 0.40', 560.00 ± 0.23') than those of control (304.66 ± 0.23', 285.06± 0.40"), respectively (p<0.05). However, results of the yield analysis did not show a significant difference between the developed method (32.40 ± 0.01) and the control (24.80 ± 0.08). A low purity value (10%) for crude chitin was showed by the developed method compared to prepared control (25%). However, OP chelating activity was significantly higher in the developed method (51%) compared to prepared control (-16%). Observations obtained in the 3 step extraction process suggested that butanol and citric acid were the most suitable chemicals compared to acetone and HC1. WBC, FBC and chelating activity of chitosan extracted by the present method can be involved in many applications. In contrast to previous studies, the present research showed that the suggested method is a simple way to extract chitin. Keywords: Chitin, Prawn shell, Demineralization, Decolourization, CeChelating activity
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    Development of Natural Mosquito Repellent Coil Using Tea Fluff as a Filler Material
    (Uva Wellassa University of Sri Lanka, 2016) Ranasinghe, R.M.D.C.S.; Alakolanga, A.G.A.W.; Weerawansha, A.N.R.; Samaranayaka, H.G.H.
    Control of mosquitoes is of extreme importance at the present day, with increasing number of mosquito borne illnesses. Therefore specialty products like mosquito repellents are used to combat mosquitoes. Chemical mosquito repellents have a remarkable safety profile, but they are toxic. Due to its high health risk researchers are making attempts to find out new filler materials and active ingredients derived from natural plants. Tea fluff has the required properties of the filler material. Hence tea fluff as a waste product produced during the secondary manufacturing process of the Camellia sinensis, can be utilized as a filler material for the production of the natural mosquito repellent coil. Citronella (Cymbopogon sp.) oil was used as the natural repellent. The preliminary trials were conducted with seven different tea fluff and binder ratios to find out the suitable tea fluff and binder range. Ratios were selected based on the sensory evaluations which were breakability, width, color, appearance and overall acceptability as sensory parameters based on 5-point hedonic scale. The effectiveness of the mosquito coils were evaluated on flammability, burning time and mosquito repellency level. 3% repellent level was identified as the best effective mosquito repellency level without causing human toxicities. Mosquito repellency level tests were conducted according to the World Health Organization reference and as the test arena model of Peet Grady chamber. The final product was determined through another sensory evaluation on breakability, color, aroma, appearance and overall acceptability as sensory parameters based on 5 point Hedonic scale. Data were statistically analyzed using Freidman test at 5% level of significance using MINITAB 16 statistical software. The finally developed new coil had five and half hours of burning time. Keywords: Natural mosquito repellent, Tea fluff, Filler material, Citronella, Mosquitoes
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    Effect of Tea Waste as a Urease Inhibitor in Soil
    (Uva Wellassa University of Sri Lanka, 2016) Dassanayake, K.G.N.D.; Alakolanga, A.G.A.W.
    Efficiency of urea rarely exceeds 50%, although it is one of the major fertilizer, as most ofit is lost as ammonia and CO, Urease enzyme is responsible for this break down. Excessive release of ammonia is toxic to plants, especially younger plants. Previous researches have shown that chemical compounds in drinking tea can inhibit urease enzyme to a greater extent. This research was designed to study the possibility of using refuse tea to inhibit the soil urease enzyme and slow down the hydrolysis of urea. The optimum amount of tea waste to be incorporated was determined by mixing different amounts of tea waste with constant amounts of urea and soil and released ammonia content was measured after 24 hours using Hoffman's method. The effect of time on inhibition of urease was studied by mixing constant amounts of urea with constant amounts of Tea waste and soil. Ammonia content was measured after 24 h, 48 h, 72 h, 96 h and 120 h. The effect of urease inhibition on growth conditions was also determined as follows. Soil and tea waste mixtures (10:1.5) were prepared in polythene bags with 50%, 75% and 100% urea from the recommended amount and chlorophyll content and inter nodal length were measured at two weeks intervals with "Thilina" tomato variety. Controls were prepared without tea waste and with 100% urea. Complete Randomized design was applied. The optimum amount of tea waste to be incorporated was determined as 1.5 g per 10 g of soil and per 50 mg of urea as this combination showed a 50% average inhibition. Inhibition exhibited a positive correlation with time with r2 0.976. The treatment containing 50% urea showed a significant increase in chlorophyll content than the control with p value 0.003. There was no significant difference among the treatments for intermodal length. With the results of this research, it can be concluded that the application of tea waste successfully control the hydrolysis of urea and it does not have any negative effects on growth parameters of "Thilina" tomato variety. Keywords: Urease, Inhibition, Tea waste, Urea
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    Evaluation of Octosol A-18(E) & Sodium Silico Fluoride (SSF) as Shrinkage Reduction Agents in the Continuous Natural Latex Foam Sheet Manufacturing Process
    (Uva Wellassa University of Sri Lanka, 2016) Gunasekara, P.D.A .; Alakolanga, A.G.A.W.; Weerawansha, A.N.R.
    Natural rubber latex foam sheet, which is made directly from centrifuged latex with 60 % dry rubber content and used for production of mat, mattresses or pillows. Shrinkage issue that occurs during the manufacturing process of Natural Latex Foam Sheets is a major issue which leads to greater wastages and economic losses. Shrinkage occurs during the gelling or curing period and may shrink as much as 50% in volume. However shrinkage cannot be prevent entirely and can be reduced only to an economically acceptable level. There is a possibility of using a foam stabilizer like Octosol A-18(E) to reduce the shrinkage while maintaining the expected physio-mechanical properties. Therefore, a study was conducted to find the best Octosol A-18(E) and Sodium Silico Fluoride combination which can reduce the shrinkage issue. Latex Foam was prepared and each of the sample was incorporated with Octosol A-18(E) at 0.05 phr,0.10 phr,0.15 phr,0.20 phr,0.25 phr levels and Sodium Silico Fluoride at 5.14 phr,6.14 phr,7.14 phr,8.14 phr levels. The developed twenty different foams were replicated three times and these foam were compared with a reference foam prepared without adding Octosol A-18(E) and the physio-mechanical properties were evaluated according to the ISO procedures. At 0.25 phr Octosol A-18(E) level Latex foam shows the lowest shrinkage but at that level another problem arise the "blooming" of the foam. "Blooming" of the foam can lead to the loose skin defect. However shrinkage, density and hardness decreases with increasing Octosol A-18(E) and Sodium Silica Fluoride levels than the reference sample. However compression set values decreased till 0.20 phr Octosol A-18(E) level and increased thereafter. Further this study also revealed that the effect of Sodium Silico Fluoride level on Shrinkage can be submerge by elevated Octosol A-18(E) levels. Also the results indicate that, up to 0.20 phr Octosol A-18(E) level and 5.14 phr Sodium Silico Fluoride level, most of the required properties of the foam could be maintained but the Octosol A-18(E) 0.15 phr level and Sodium Silico Fluoride level 5.14 phr level can consider as the best combination. Keywords: Octosol A-18(E), Sodium Silico Fluoride, Shrinkage, Blooming, Physio-mechanical properties
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    Expansion of Storage Time of Tread Compound of Fork Lift Tyres without Sulphur Blooming
    (Uva Wellassa University of Sri Lanka, 2016) Udeshika, D.M.A.; Alakolanga, A.G.A.W.; Wasantha, M.H.L.; Weerawansha, A.N.R.
    With rapid industrialization and agricultural advancement, road transportation is one of the most promising and potent means for existence of everything. Both solid and pneumatic tyres involved in this process. Solid tyres are used primarily for light commercial applications and personal use vehicles like forklifts. Sulphur blooming is one of the major problems encountered with them. It will cause to loss oftackiness. Therefore, solid tyres are significantly more prone to roll-over than pneumatic tyres. This study was conducted to develop a suitable chemical compound for the tread component of fork lift tyre to have a significantly high storage time without sulphur blooming. Five different compounds including soluble sulphur, insoluble sulphur, silane coupling agent and phenolic resin (bakelite) were prepared and kept for six storage time levels (12 hours, 24 hours, 36 hours, 48 hours, 60 hours and 72 hours). They were tested for cure characteristics and physical properties with respect to product specifications of fork lift tyres. The visual observations revealed that, chemical compound prepared by using soluble sulphur, silane coupling agent and phenolic resin has maximum storage of 60 hrs which did not have sulphur blooms on finished tyre surfaces. The soluble sulphur along with silane coupling agent and phenolic resin (bakelite) is more suitable for fork lift tyre compounding whereas added chemicals have significantly a favorable effect on improvement of cure characteristics and physical properties within the specifications. Keywords: Fork lift tyres, Sulphur blooming, Cure characteristics, Physical properties
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    Optimization of Sulfur: Zinc Oxide: Accelerator Ratio for Natural Rubber Latex Unsupported Gloves
    (Uva Wellassa University of Sri Lanka, 2016) Kithmini, N.C.Y.; Alakolanga, A.G.A.W.; Ariyananda, P.
    Glove is one of most important export product which holds a significant place in rubber latex dipping industry in Sri Lanka. Different chemical ingredients are incorporated with centrifuge latex in compounding for glove production. Among them, the ratio of S, ZnO and accelerator plays an important role on vulcanization rate and the properties of the end product. The existing ratio which used in the glove industry is identified as having some wastage of above ingredients. Therefore, an investigation was carried out to optimize the S, ZnO and accelerator ratio while maintaining same physical properties in natural rubber latex unsupported gloves. The dispersions of 50 % Zinc Oxide, 50 % Sulfur and 50 % Accelerator were prepared successfully. Nine compounds including the control were prepared by changing the ZnO, Sulfur and accelerator ratio within the selected minimum and maximum limits while all the other ingredients are constant. The existing compound was used as the control and the physical properties of finished gloves; tensile strength, elongation, force at peak were measured. The results indicated a significant effect of different amount of dispersions on the physical properties. The treatment 4 (ZnO 0.1: Sulfur 0.3: Accelerator 1.0) was identified as the best treatment which resulted the best tensile strength (>17 Nmni2), elongation (>700 %) and force at peak (>7 N) compared to the specifications of the properties of natural rubber latex disposable gloves. The cost of glove production was successfully reduced by eliminating the excess amount of ingredients in the selected compound while maintaining the properties as well. Keywords: Vulcanization rate, Unsupported gloves, Tensile strength, Elongation, Force at peak
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    A Preliminary Study on Absorption of Heavy Metal (Lead) From Synthetic Waste Water Using Mullet (Mugil spp.) Fish Scales
    (Uva Wellassa University of Sri Lanka, 2016) Herath, H.M.S.S.; Alakolanga, A.G.A.W.; Abeyrathne, E.D.N.S.
    Heavy metals are relative dense metals present in earth crust that are in high accumulation level in water bodies. Among several technologies to remove these heavy metals, biosorption is a novel concept that use in waste water facilities. This study was carried out tofind the feasibility of using mullet (Mugilidae spp.) fish scales as a biosorbant and find the best cost effective form of mullet fish scales to absorb heavy metal (Pb) in synthetic waste water.The effect of oven drying conditions, particle size, and dosage of fish scales and pH for the absorption of heavy metal (Pb) absorption were investigated by Atomic Absorption Spectrophotometer (AA240, 283.33 nm, Varian., Australia). The reusability was investigated with the use of nitric and hydrochloric acids. The highest mean absorption results were obtained for 3 g (98.70 0.73) of damaged 1-2 cm2 size (92.03 ± 0.51) with oven drying conditions of 80°C (99.10 ± 0.52) for 24 hours (93.93 ± 2.38). All parameters were indicated that there was a significant difference among the treatments (P < 0.05). In addition to that, absorption was not depended on pH and reusable ability was high with the nitric (19.83 ± 5.66) compared to hydrochloric acid (3.09 ± 0.37). But in cost effective manner new fish scales were more applicable. The observed reason for the efficient biosorption from the fish scales were the crystal structure, chemical composition of hydroxyapatite with porous structure and the highly ordered three dimensional structure of collagen. This research revealed that, there is a high potential to use mullet fish scales as a biosorbant for treat waste water in wastewater treatment facilities and it is a rapid, cost effective and high efficient biosorbant among other biosorbants. Keywords: Heavy metal, Biosorption, Cost effective, Hydroxyapatite, Collagen