Vol. 12, Issue 1, January 2017

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Now showing 1 - 11 of 11

First-Principles Study of Structural, Electronic and Optical Properties of Lead-Free Organic Inorganic Tin Halide Perovskites for Photovoltaic Applications
(Daffodil International University, 17-01-01) 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.
Profitability of Granite Quarry Operation in Akure South Local Government Area of Ondo State, Nigeria
(Daffodil International University, 2017-01-01) 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.
Determination Of Rock Discontinuity For Prediction of Blasting Performances Using Quantitative and Qualitative Parametero
(Daffodil International University, 2017-01-01) 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.
Developed a Calibration Method in Gamma Ray Spectrometry For Environmental Samples
(Daffodil International University, 2017-01-01) Banik, Subrata
In gamma ray spectrometry, a rigorous determination of radionuclide concentration for voluminous samples depends mostly on the proper efficiency calibration. The detection efficiency may differ due to sample density, sample measurement geometry, self–absorption and detection system, etc. The aim of this work to evaluate how the efficiencies are varied in different measurement regimes for environmental samples. The efficiency calibration was observed in gamma measurement system (HPGe detectors) with the relative efficiency of 40%. Environmental samples with the density ranging from 0.55 to 1.59 g/cm3 in 240 cm3 cylindrical containers were used for efficiency calibration having gamma energy 121 KeV to 1409 KeV. All the secondary reference materials were made by using Eu-152 standard liquid source. The variation of efficiency was found from 63.2% to 76.8% due to the difference in sample matrix and variation due sample position from detector surface was 6% to 40%. Whilst due to variation in sample weight the calculated efficiency values were ranging from 27% to 60%. The evaluated result will be useful to calculate the accurate radionuclide concentration in environmental sample.
Empirical Study of Cyclomatic Complexity and Interface Complexity of Evolving Open Source Systems
(Daffodil International University, 2017-01-01) Michael A, Olatunji; Oladele, Rufus O.; Bajeh, Amos O
This paper aims at investigating the validity of Lehman's Law of Increasing Complexity. Two metrics namely cyclomatic complexity and interface complexity were defined to capture increasing complexity. The goal was to verify if these metrics can be used to validate Lehman’s law of increasing complexity. Empirical analysis was performed using historical data collected on four evolving Open Source Systems (OSS). Results show that the considered Lehman’s law is partially supported by the collected data and the metrics. In particular, empirical results reveal that: total cyclomatic complexity and total interface complexity are increasing from version to version; average cyclomatic complexity and average interface complexity either declines or increases within a very short range; and function interface complexity hardly decline in evolving OSS. Also, the addition of low complex functions reduce cyclomatic complexity in evolving OSS but does little in reducing function interface complexity.
On Nyorrauf Transformation Algorithm of Flight Crew Scheduling Problems
(Daffodil International University, 2017-01-01) Kamilu, Rauf; Ngutor, Nyor; Olorunju, Omolehin Joseph; Adebayo, Owolabi Abiodun
In this work, we applied NyorRauf Transformation Algorithm to a flight crew scheduling problem to assess its impact on crew scheduling models. The result yielded a solution that is implementable by airlines. It was concluded that, generally speaking, the transformation algorithm is efficient in the Karmarkar Interior Point scheme for solving Linear Programming Problems.
Re- Innovation of Home-Décor: Effect of Process Parameters on Designing and Development of Computer Assisted Embroidered Cushion Covers
(Daffodil International University, 2017-03-27) Khanna, Shelly; Kaur, Amandeep
The computerized embroidery process was investigated for the process variables as fabric type, motif parameters and embroidery thread, with their impact on the quality of the embroidered articles thus produced. Four sets of cotton based fabrics namely khadi, satin, velvet and Organdie with silk embroidery threads were used to experiment upon the suitability of the digital motifs along with their placement. Khadi fabric was the most suitable base for computerized work in terms of quality adjudgement parameters as fabric distortion, needle breaks, thread breaks, skipped areas and clarity index. Cushion covers were designed and developed as an interpretation of the custom designed respondent survey and costing evaluation was also carried out for the end- product.
Finite Difference Solution of Unsteady Free Convection Heat and Mass Transfer Flow Past a Vertical Plate
(Daffodil International University, 2017-04-04) Arifuzzaman, Md.; Mondal, Rabindra Nath
An analysis is performed numerically to study the unsteady free convection heat and mass transfer flow past a semi-infinite vertical flat plate by using finite difference method. First, thermal boundary layer equations have been derived from the Navier-Stokes equation and concentration equation by boundary layer technique. Second, some non-dimensional variable has been introduced to make these equations dimensionless. Then Finite difference method is used to solve these equations. The solution of heat and mass transfer flow is studied examining the velocity, temperature and concentration distribution. The effects on the velocity profiles, temperature profiles and concentration profiles for various parameters have been separately discussed and shown graphically.
Ecological Impact of Effluents Discharged After Dyeing Cotton Knit Fabric With Reactive Dyes
(Daffodil International University, 2017-05-01) Swati, Sushama Saha; Mozumder, Sumon; Majumder, S.M.M.H.
This study mainly refers to investigate the environmental impact of textile effluents discharged after dyeing cotton knit fabric with eight different reactive shades. By this work it was possible to evaluate the influence of each shade on the present ecological system. Textile effluents generated after dyeing with eight shades were collected to analyze the ecological parameters, including acidity or alkalinity (pH), amount of dissolved oxygen (DO), total dissolved solids (TDS), temperature and visual colors. From the experimental data it can be said that the effluents produced from the dyeing process comprising primarily more alkalinity, less DO, more TDS, high temperature and nearly black color which have indubitably adverse effects on the biological system. Furthermore, all reactive dyes were not found to be equally responsible to affect the surroundings. Hence, this research work becomes vital to recommend a suitable reactive dye having low impact on the environment.
A University Examination Web Application Based on Linear-Sequential Life Cycle Model
(Daffodil International University, 2017-05-20) Bello, Ridwan Oluwaseun; Olugbebi, Muyiwa; Babatunde, Abdulrauph Olanrewaju; Bello, Bashir Omolaran; Bello, Shakirat Iyabo
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
Effect of Different Block Cipher Modes of Operation for Secured Data Transmission in Convolutional Encoded Dwt Based Mimo Mc-Cdma System
(Daffodil International University, 2017-06-26) Shams, Rifat Ara
In this proposed model, performance of different block cipher Modes of operation over ZF channel equalization technique and BPSK modulation scheme in DWT based MIMO Multi-Carrier Code Division Multiple Access (MC-CDMA) system has been analyzed for security issues through simulation. This system is proposed using convolutional coding scheme over AWGN and Rayleigh fading channel with Walsh Hadamard code as orthogonal spreading code. In this research paper, the performance of Electronic Codebook (ECB) mode, Cipher Block Chaining (CBC) mode, Cipher Feedback (CFB) mode, Output Feedback (OFB) mode and Counter (CTR) mode is compared as cryptographic algorithms to encrypt the actual data and decrypt its original form.