http://ir.lib.seu.ac.lk/handle/123456789/5855 ASRS - 2021 2026-04-06T01:34:33Z http://ir.lib.seu.ac.lk/handle/123456789/5913 Title: Tourism and economic growth in Sri Lanka: an ARDL bound test approach Authors: Wickramasinghe, T. G. A. P. M.; Jahufer, A. Abstract: The contribution of the tourism industry to the economic growth of Sri Lanka is very important. It is a vital segment of the Sri Lankan economy. The purpose of this study is to explore the contribution of tourism to the economic growth of Sri Lanka. The Autoregressive Distributed Lag bounds testing approach is used as the analytical process to find the long-run and short-run behaviors between the Sri Lankan tourism industry and economic growth using three variables real gross domestic product, international tourist arrivals, and real effective exchange rate. Altogether, this analysis reveals that in both the short run and long run, tourism positively impacts the economic growth of Sri Lanka. Thus, it is important for the Sri Lanka government to focus on the development of tourism infrastructure and proving political solutions, resolving conflicts which make negative consequences on Sri Lanka tourism industry. 2021-11-30T00:00:00Z http://ir.lib.seu.ac.lk/handle/123456789/5912 Title: The effect of annealing steps of spin coated Sb2S3 film in planar structure solar cells Authors: Farhana, M. A.; Bandara, J. Abstract: The inorganic Sb2S3 thin-film solar cells have increasing attention due to their merit features, which are suitable for solar cell applications. The performance of solar devices is varied based on different conditions of film deposition. The annealing temperature is an important factor in the spin-coated Sb2S3 layers because it changes from amorphous to crystalline during the preparation. Therefore, the present work was done by a step-annealing process of Sb2S3. Herein, Sb2S3 precursor was prepared by using 1 mmol of Sb2S3 and 1.5 mmol of thiourea in 1 ml of 2-methoxy ethanol and it was spin-coated at 4000 rpm on com-TiO2/FTO. Just after coating, the cells were annealed in two different conditions. For the first condition, the coated Sb2S3 was pre-heated inside the tube furnace at 160 oC for 1 minute, then again annealed at 280 oC for 10 minutes. In the second condition, the Sb2S3 was annealed in a single step at 280 oC for 10 minutes. All these annealing processes have proceeded under the N2 stream. In the cell with a two-step annealing, the desired phase was synthesized and photo-generated electron-hole pairs effectively converted. By improving the photovoltaic parameters, the power conversion efficiency (PCE) of 1.76% was achieved in a configuration of FTO/com-TiO2/Sb2S3/P3HT/Ag. 2021-11-30T00:00:00Z http://ir.lib.seu.ac.lk/handle/123456789/5911 Title: A cyclic voltammetry study of polypyrrole conducting polymer film in aqueous BaCl2 and LiCl electrolytes Authors: Farhan, M. S. M.; Jafeen, M. J. M. Abstract: The emergence of electronically conducting polymers having fascinating properties has opened up a novel class of polymers suitable for modern applications, including smart soft actuators or ‘artificial muscles”. The change in volume of these polymers when the redox state is altered in aqueous electrolytes is exploited in these actuators. The actuation property of these polymers highly depends on cycling electrolytes, types, and concentrations. The present study aims to explore the possibilities to use Polypyrrole, doped with the immobile anion dodecyl benzene sulfonate (PPy/DBS) films cycled in LiCl and BaCl2 electrolytes. In this study, PPy (DBS) films of thickness 400 nm were electropolymerized on 6 MHz AT-cut quartz crystal electrodes from a synthesized solution containing 0.05 M pyrrole monomer in 0.05 M NaDBS solution and characterized by simultaneous cyclic voltammetry and Electrochemical Quartz Crystal Microbalance (EQCM) measurements. The films were cycled in 0.1 M BaCl2 0.1 M LiCl, 2 M LiCl, and 1 M BaCl2 electrolytes. The actuation mechanism of the film in LiCl electrolytes (up to 2M concentrations) is exclusively based on cations motions while that in BaCl 2 (up to 1M concentrations) is contributed with both cations and anions in electrolytes. It implies that the redox ionic motion resulting from the actuation of PPy (DBS) films is not exclusively based on metallic ion presence in the electrolyte but depends on the type of metallic ions present in the cycling electrolytes used. When compared with high and low concentrations in LiCl and BaCl2, a larger frequency change was obtained in low concentrations rather than in higher concentrations, indicating that the actuation in thin concentrations is larger than higher. 2021-11-30T00:00:00Z http://ir.lib.seu.ac.lk/handle/123456789/5910 Title: Interpolation: a Taylor polynomial approach Authors: Sasni, M. I. S.; Faham, M. A. A. M. Abstract: Interpolation is a technique that calculates the unknown values from known given values within a certain range. Whereas the process of calculating unknown values beyond a certain given range is called extrapolation. However, the term interpolation includes extrapolation. Many operators require weak interpolation theory to accurately describe their cartographic properties. For example, Anthony P.Austin (2016) discussed several topics related to interpolation and how it is used in numerical analysis. Biswajit Das, Dhritikesh Chakrabarty (2016) had developed an interpolation formula derived from Lagrange’s interpolation formula. The formula obtained had been applied to represent the numerical data, on the total population of India by a suitable polynomial. Slawomir Sujecki (2013) proposed an extension of the concept of the Taylor series to arbitrary functions that are physically meaningful. The prime objective of our work is to construct a model for interpolation to get a better approximation compared to some existing methods. In this research, we aimed to approximate the Taylor polynomial of unknown function by known data set. We obtained a system of equations by substituting known data set to the Taylor polynomial and found the derivatives needed for the interpolation model using the system of equations. Then we intended to compare the proposed method with some existing methods taking single polynomial, trigonometric and exponential functions as test functions. Also, we compared our model with a well-known existing method, polynomial interpolation. The proposed model overlaps on the polynomial function and exponential function when 5 points are taken with an even comparatively larger step size. The error of our model is less than the error of polynomial interpolation throughout the range in both cases. However, the proposed model deviates from the test function when using a small number of feed data for the trigonometric function. When increased the feed data, our model and the trigonometric function fall on the same curve whereas the usual polynomial interpolation deviates much from the trigonometric function. Consequently, we can conclude that the proposed model performs better than polynomial interpolation for polynomial, trigonometric and exponential functions. And in the case of the increased amount of feed data, we record improved accuracy at interpolating procedure. 2021-11-30T00:00:00Z