Volume 26, No. 1 (2020)
Articles
INVESTIGATING ELECTRICITY CONSUMPTION IN OGUN STATE, NIGERIA
BADEJO BAMIDELE(1), OLASUNKANMI OMOWUMI(2), OGUNSEYE NATHANIEL(*3)
This study examined electricity consumption in a Nigeria township with a view of understanding the challenges faced by electricity consumers and to proffer practicable suggestions for sustainable electricity supply. Major findings emanating from the study show that 26.7 % of respondents acknowledged the electricity supply through the electricity service provider (ESP). Again, 71 % of respondents relied on electricity through the alternative’s sources complementing ESP services. Furthermore, 75 % of respondents confirmed a temporal supply of 5 hours daily representing 20 % daily electricity supply. In another dimension, in terms of billing, 62.4 % received estimated electricity bills as many homes are without electricity meters. Finally, this study revealed some planning and policy implications and provided recommendations through which electricity consumption in the state could be improved upon.
NEW PHOSPHINATO ORGANO- AND HALOTIN(IV) DERIVATIVES, ADDUCTS AND COMPLEXES: SYNTHESIS AND SPECTROSCOPIC STUDY
SEYDOU BASSENE(1), MOUHAMADOU SEMBENE BOYE(*2), MAMADOU SIDIBE(1), LIBASSE DIOP(1)
Five new phosphinato derivatives, adducts and complexes have been synthesized and characterized by infrared and Mössbauer spectroscopies. Based on their spectroscopic data discrete or infinite chain structures are proposed, the phosphinate ion behaving as a bicoordinating bridging or a monocoordinating ligand, the environments around the tin (IV) centers being octahedral or trigonal bipyramidal. In Me4N(SnPh2)2(H2PO2)2Cl3 and Cl2Sn(H2PO2)2NMe4H2PO2, the cation is involved in electrostatic interactions with the anions.
DESIGN ANALYSIS OF A LOW-COST PARABOLIC ANTENNA FOR DEVELOPING NATION
ONAIFO FRANK(*1), OKANDEJI ALEXANDER AKPOFURE(1), IDOWU FISAYO(1), OLASUNKANMI OMOWUMMI GRACE(1), OLALUWOYE OLAWALE(2), FOLORUNSHO OLAOLU(2)
This paper is aimed at designing a locally fabricated fiberglass parabolic antenna as a replacement for a metallic fabricated parabolic antenna. They are coated with a thin film of aluminum dust to enhance reflectivity since electromagnetic radiations do not travel deep in a conductor. This reduces the thick mass of metal usually used for constructing metallic parabolic antenna leading to a reduced cost of production. It incorporates a Low Noise Block (LNB) Converter comprising of amplifiers and frequency down converter. Metallic parabolic antenna contributes more to signal loss by reflecting radio waves. The Parabolic antenna is designed to receive microwave signals in the K-band with the down converter converting it to very high frequency (VHF) and ultra-high frequency (UHF) employing the super-heterodyning principle. The study shows the design and installation of a low-cost parabolic antenna in the rural community in Nigeria. The designed parabolic antenna is used to receive a signal with the center frequency of 11.3GHz and signal strength of 60%. The economic viability is that fiber-glass Parabolic antenna can replace the metallic fabricated ones.
ERGONOMIC EVALUATION OF PACKAGING WORKERS’ POSTURE IN A FOOD MANUFACTURING COMPANY
SALAMI OLASUNKANMI ISMAILA(1) , YUSUF ADEYEMI SALAMI(1), SIDIKATU IBIYEMI KUYE(1), OLAWALE USMAN DAIRO(2), NURUDEEN OLATUNDE ADEKUNLE(1)
This study conducted an ergonomic evaluation of the working posture of workers engaged in various processes in the packaging section of a food manufacturing company. Workers in the packaging section of the food manufacturing company were divided into operating, folding, packing, carton wrapping and palletizing. Forty of the workers in the packaging section were placed under observation through video recording of their daily activities for a period of three months to obtain their working postures. Rapid Upper Limb Assessment (RULA) was used to analyze the working postures in order to obtain their ergonomic risk levels. Computer codes for RULA were written for quick and easy evaluation of upper arm, lower arm, wrist, wrist twist, neck, trunk and leg postures. The results from RULA indicated that 25% of the workers in the operating and folding units were exposed to medium ergonomic risk level; 30% of the workers in the packing unit and 10% of the workers in the carton wrapping unit were exposed to high ergonomic risk level while 10% of the workers in the palletizing unit were exposed to a very high ergonomic risk level. The study concluded that workers in the packaging section of the food manufacturing company were exposed to between medium and very high ergonomic risk levels of working posture necessitating the need to change the conditions of their workstations.
A CFD ANALYSIS IN SOLIDWORKS FLOW SIMULATION FOR TWO MIXING FLUIDS WITH DIFFERENT TEMPERATURES IN NOZZLES
OLARU IONEL
The heat can have a direct impact on the mechanical elements by creating deformations and by causing the induction of additional stress in them. In designing of the heat exchangers or for the electronic components, the temperature changes for structural analysis as well as structural performance of thermal impact for the entire element must be analyzed. The study from this paper proposes an analysis and a simulation of flow through the convergent-divergent nozzle type to optimize the inlet of warm fluid to have minimum impact on the nozzle walls This analysis will be performed with a computer program specialized in complex analysis of Computational Fluid Dynamics (CFD), which will also take into account the fluid temperature and its influence throughout the system.
SHRINKAGE AND CREEP CHARACTERISTICS OF PALM KERNEL SHELL CONCRETE
ADETUKASI ADESOLA OLAYINKA(*1), IKPONMWOSA EFE EWAEN(1)
This research work evaluates the shrinkage and creep characteristics of concrete containing Palm Kernel Shell (PKS) as partial replacement of natural coarse aggregate. Concrete was mixed at 0.55 water-cement ratio, mix proportion of 1:1:2 and percentage replacement of natural aggregate with PKS at 0%, 25 % and 50%. The creep and shrinkage results of Palm Kernel Shell Concrete (PKSC), increased as the percentage content of PKS increased in the concrete. The maximum creep strain observed for normal concrete, 25 % and 50 % PKS content were 0.00018 mm/m, 0.00057 mm/m and 0.00094 mm/m respectively. The maximum total shrinkage strain recorded for 0%, 25% and 50 % PKS content was 0.00102 mm/m, 0.00183 mm/m and 0.00247 mm/m respectively.
USE OF NATURAL DOLOMITE AS A CHEAP FOAMING AGENT FOR PRODUCING GLASS FOAMS FROM GLASS WASTE IN THE MICROWAVE FIELD
LUCIAN PAUNESCU(*1), MARIUS FLORIN DRAGOESCU(1), SORIN MIRCEA AXINTE(1,2)
The paper presents experimental results obtained in the process of making glass foam from glass waste using a cheap foaming agent (natural dolomite). The originality of the work is the application of the microwave energy, unlike the conventional techniques commonly used in the world. The main advantage highlighted by the experiments is the very low specific energy consumption (below 1.5 kWh/kg), due to the peculiarities of the microwave heating technique. The foamed product has physical, mechanical and morphological characteristics (density between 0.30-0.32 g/cm3, thermal conductivity between 0.064-0.067 W/m·K, compressive strength in the range 2.2-2.6 MPa), which are similar to those of foams made by conventional methods and are suitable for its use as insulating material in construction.
OPTIMIZATION OF TURNING PARAMETERS USING AN ALGORTIM BASED ON COMBINED LINEAR AND BINARY SEARCH METHODS
DAN GEORGE PRUTICA(*1), GHEORGHE BRABIE(1), BOGDAN CHIRITA(1)
Optimization of cutting parameters in machining operations is a complex task requiring extensive knowledge and experience to reach the maximum potential for cost reductions in manufacturing. Through the work presented in this paper a cutting parameters optimization algorithm for roughing and finishing turning has been realized. The proposed optimization algorithm is based on a combination of linear search and binary search methods, heaving as objective criterion the minimization of the machining time. Examples for roughing and finishing turning have been presented to illustrate the application of the proposed algorithm and analyse the results.
AUTOMATED CUTTING TOOLS SELECTION FOR BEARINGS COMPONENTS TURNING PROCESS
DAN GEORGE PRUTICA(*1), GHEORGHE BRABIE(1), BOGDAN CHIRITA(1)
Due to the high potential of improving efficiency and productivity in machining operations, the automated cutting tools selection and the optimization of cutting parameters has been an area of high interest for many researchers in the frame of CAPP systems development. Through the work presented in this paper an automated cutting tools selection algorithm for roughing and finishing turning has been realized. An example for turning of the outer rings for large-size single row cylindrical roller bearings has been presented to illustrate the application of the proposed algorithm and analyze the results.
SHIELDING OF NOISE SOURCES USING ACOUSTIC SCREENS COMPOSED
CLAUDIA TOMOZEI(1), OANA IRIMIA(1), MIRELA PANAINTE-LEHADUS(1), FLORIN NEDEFF(1)
The paper presents some experiments in which was used acoustic screens performed in two combinations of material layers. First variant of experimentation was the one in which the walls of the acoustic screens were performed by alternating the layers of OSB - mineral wool – plasterboard. In the second variant was used the combination layers of OSB - mineral wool - corrugated cardboard. The noise level measurements were made of the acoustic screen on construction type with three walls and three walls and lid. The recordings of the noise level were achieved by positioning the source in 4 measuring points and the microphone (receiver) in 16 points. Measurement results showed the best variant of work.