Thin film materials for the production of low energy density devices such as supercacitors are very attractive because of the positive impact on the environment. Metal oxides thin films materials are widely used due to their unique properties unlike single structured metal oxide thin films which amy suffer from low efficiency under visible light. In this study the doping of ZnO thin films with Ag form a composite material with new properties due to synergetic effect. The synthesis of ZnO thin film was by electrodeposition technique after which the optical properties were characterized using UV-VIS spectrometer. A slight shift in the absorption spectra to the higher wave length was observed in all the samples. It can be seen that the optical transmission of pure ZnO is about 47 % at 1026 nm in the visible region and after doping it increased to 71 % at 950 nm due to the presence of impurity; negative reflectance spectra shown by most samples is an indication of the incident and refracted wave travelling in the same direction. The optical energy gap of the doped samples ranges from 3.32-3.43 eV, these observations show that the Ag behavior as a p-type dopant of ZnO is good for the realization of low energy density devices such as supercapacitors.
Cisssan Sylvanus (2022) Thin Film Investigation of Silver Doped Zinc Oxide as Electrode Material, European Journal of Material Science, 9, (1), 44-63
Characteristics and Composition of Fermentation Containers, Its Effect on Ph and Some Functional Properties for Effective and Sustainable Fermentation of Locust Beans (Parkia biglobosa) (Published)
The choice for type of container to be used for effective and sustainable fermentation of locust bean (Iru) has been of contention by local processors having preference for some materials over others. Calabash gourd, highly dense polyethylene (plastic) and stainless steel were used to ferment locust bean for a threshold of 72 hrs. pH of significant difference p<0.005 was obtained from calabash gourd 6.02, plastic 5.95, and stainless steel 5.8. Insignificant differences were obtained in bulk density, water absorption capacity and oil absorption capacity.Iheke et al 2017 reported increase in pH with fermentation time and Olasupo et al 2016 reported a threshold of pH 8.2 after four days of fermentation. The three respective containers have low thermal and electrical conductivities but calabash, a polymer of lignin fused with cellulose has the lowest thermal and electrical conductivities of 0.163W/MK and 0.01 W/mK at 25oc respectively, followed by plastic a polymer of polyethylene with 0.4W/Mk and 0.44W/mK at 25oc respectively, and stainless steel an alloy of Iron, Chromium, Nickel, Molybdenum, Carbon, Manganese and Nitrogen having the highest values of 15 W/mK and 16W/Mk at 25o c. The insulating capacity and ability to retain and sustain heat in a closed system is inversely proportional to both thermal and electrical conductivities.
The Development of Contextual Approach-Based Materials for Poetry Writing On Grade X Student In Sma Budi Murni 2 Medan (Published)
This research is based on the learning problems of class X students of SMA Budi Murni 2 that are still teacher-centered. This causes students not being able to study independently because of the lack of poetry text references used in poetry writing class. In addition, the student’s ability to write poetry texts is known to be low because the teaching materials used by teachers and students are still based on textbooks. The book is the only source of information for poetry text writing study. In learning to write poetry texts, teacher sometimes still use learning methods that tend to be monotonous, such as the use of discussion methods. This is known from the results of observations made by the researchers themselves. All poetry texts writing learning comes from textbooks. Based on the above problems, the researcher conducted a research development aimed at (1) to analyze the development process of the contextual approach-based poetry text writing materials on grade X student in SMA Budi Murni 2 Medan, (2) to analyze the feasibility of the contextual approach-based poetry text writing materials on grade X student in SMA Budi Murni 2 Medan, (3) to analyze the effectiveness of the contextual approach-based poetry text writing materials on grade X student in SMA Budi Murni 2 Medan. The method adopted is the Research and development (R&D) proposed by Sugiyono, based on Borg and Gall. The trial subjects consisted of 3 students in individual test, 9 students in small group test, and 35 students in limited field test. The data collection technique used observation, interviews, questionnaire, and poetry text writing test. The research result shows that (1) material expert’s validation includes content feasibility with an average of 83,52% in “very good” criteria, presentation eligibility with an average of 87,5% in “very good” criteria, and language aspect with an average of 75% in “good” criteria, (2) graphyc design expert’s validation with an average of 83,46% in “very good” criteria, (3) teachers’ responses with an average of 88,23% in “very good” criteria, (4) individual test with an average of 77,77% in “very good” criteria, (5) small group test with an average of 80,10% in “very good” criteria, (6) limited field test with an average of 84,82% in “very good” criteria. The learning outcomes of student’s poetry writing before using the module was 74.28, while after using the module increased up to 85.57. The resulted difference between before and after the module usage is as much as 11.29. The implication of this study is that, the developed teaching materials may provide practical contributions in the implementation of the learning process for teacher. This is because the additional teaching materials provide convenience in the process of teaching.
Finite element analysis of the camshafts assembly of different materials with different meshing conditions has been conducted in the present work. Camshafts of Grey Cast Iron, Nodular Cast Iron and EN 18 materials have been considered for analysis in the present work. SolidWorks and ANSYS Software have been used for drafting and FEA analysis of camshaft respectively. The effect of different meshing elements i.e. 10mm, 50mm and 100mm has also been studied. From the results, it has been found that with decrement in the element size, number of nodes and elements increases continuously showing a fine meshing. The effect of different magnitude of load has also been analysed. During analysis, it has been varied from 1kN-1000kN by multiple of 10. Analysis has been done on the basis of deformation, stress and strain generating in the camshaft. It has been found that with increment in the load, deformation and stress generating in the camshaft assembly increase continuously indicating large deformation. It has also been found that the total deformation in the camshaft of EN 18 material is less compared to grey cast iron and nodular cast iron. Camshaft made of nodular cast iron weighs less compared to the camshaft made of grey cast iron and EN 18
AN EXPERIMENTAL INVESTIGATION OF MOISTURE EFFECT ON FATIGUE BEHAVIOR OF COMPOSITE MATERIALS (Published)
In this study the effect of moisture content on the fatigue behavior of the composite materials is investigated. Samples of random and woven fibers with polyester resin are used in this study. The samples are immersed in water for different period’s .The moisture content is measured .The results Showed that the moisture content has a significant effect on the fatigue life of the composite materials. The fatigue life decreases as the moisture content increase.