http://dspace.daffodilvarsity.edu.bd:8080/handle/123456789/8929 2026-04-27T00:26:02Z http://dspace.daffodilvarsity.edu.bd:8080/handle/123456789/8974 First-Principles Study of Structural, Electronic and Optical Properties of Lead-Free Organic Inorganic Tin Halide Perovskites for Photovoltaic Applications Shalauddin Promising candidates in this respect are organometal perovskites ABX3, which have been intensely investigated during the last years. In this work, we have calculated the geometry optimization, band structure, optical properties and carrier mobility for tetragonal phase of non-toxic perovskite halide CH3NH3SnCl3 and CH3NH3SnI3 by applying density functional theory (DFT) with the generalized gradient approximation (GGA) correlation of Perdew-Berke-Erzndof (PBE). The results have showed that CH3NH3SnCl3and CH3NH3SnI3 have good optical absorption coefficient, which can be a good application for solar light harvester. 0017-01-01T00:00:00Z http://dspace.daffodilvarsity.edu.bd:8080/handle/123456789/8973 A University Examination Web Application Based on Linear-Sequential Life Cycle Model E-examination application has been used as communication and information remedy to the paper-related examination approach. The application is efficient, time-saving and resourceful. The E-examination is designed to improve examination process among educational institutions. The system can be used to conduct varying examination questions including theory-based and multiple-choice formats. In this study, an application that offers an equitable security and accuracy in examination conduct were developed. The objective of this application is to enable students to attempt examination online via intranet or the internet, using Windows Operating System. The application was also designed with the use of web-related database backend including Hypertext Preprocessor, Hypertext Markup Languages, My Structured Query Language and Cascading Style Sheet, Javascript The system ensures uniform accessibility to the web browser and enables the system to run on varied operating models. It is very robust and cheap. E-examination system can be improved utilizing integrated biometric applications including face 2017-05-20T00:00:00Z http://dspace.daffodilvarsity.edu.bd:8080/handle/123456789/8972 Determination Of Rock Discontinuity For Prediction of Blasting Performances Using Quantitative and Qualitative Parametero Alaba, O.C.; Adeniyi, T.O.; Agbalajobi, S.A. The study assesses quantitative and qualitative parameters of rock discontinuity in some selected quarries in Ekiti and Ondo state for prediction of blasting performances. Scanline method of discontinuity measurement was used to measure 200 discontinuities from RCF granite quarry, 99 discontinuities from Kopek granite quarry and 303 discontinuities from Samchase granite quarry at a distance of 20m, 25m and 20m from each quarry bench face. Quantitative and qualitative discontinuities parameters were measured and the values obtained were recorded in frequency table with class intervals of 10-100 for dip angle, 0.01 - 0.10m for spacing and 0.01 - 0.25m for persistence. The graphs of frequency against discontinuity values were plotted. The results show that the mean spacing of the three granite quarries outcrop (357mm, 337.8mm and 343.4mm) were within 200mm - 600mm [1]discontinuity spacing classification table which indicates that the outcrops were moderately spaced. Also, the persistence values of the granite quarries outcrop (1.0019m, 1.4205m and 1.4205m) were within 1m - 3m [1] discontinuity persistence classification table which indicates that the outcrops have low persistence. The quarries have rock masses of high uniaxial compressive strengths (152.320MPa, 132.256MPa and 120.973MPa) and high point load strengths (13.732MPa, 9.713MPa and 1.953MPa). The moderately spaced outcrop, low persistence outcrop and high strengths outcrop indicates good blast performance for the three quarries. 2017-01-01T00:00:00Z http://dspace.daffodilvarsity.edu.bd:8080/handle/123456789/8971 Profitability of Granite Quarry Operation in Akure South Local Government Area of Ondo State, Nigeria Alaba, O.C.; Agbalajobi, S.A The study assesses the economic profitability of granite aggregates production using Akure South Local Government Area of Ondo State, Nigeria as a case study. Three quarries were selected within the northern, southern and central part of Akure South Local Government Area and they were subjected to economic analysis based on their present operational status. Data was collected on performance characteristics of each of the quarries taking into consideration the cost implication of the basic cycles of operation. The data collected were then subjected to a pro-forma cash flow analyses for both short-run and long-run term investment. The result obtained shows that two quarries (Francisca Muinat Company (FMC) and Ebenezer Mining and Ceramic Company (EMCC)) out of the three quarries achieved returns on investment before the end of the first year of operation while the third company (Fountain Construction Company (FCC)) achieved return after the end of first year. The FMC recorded a profit of ₦570,380,000 while EMCC recorded a profit ₦563,210,000 and FCC recorded a profit of ₦369,539,100 within the first 8 years of operations. The study thereby concluded that as much as granite business is a capital intensive yet is a profitable business if is properly managed. 2017-01-01T00:00:00Z