Volume 26, No. 3 (2020)
Articles
QUADRIFILAR HELIX ANTENNA FOR WEATHER SATELLITE RECEPTION
ENOCH ADEAGBO(1,2*), WALIU APENA(1,3), KAYODE AKINGBADE(1,2)
The study designed and implemented quadrifilar helix antenna (QHA) for weather satellite signal reception. The antenna design and optimization were done by varying the element diameter, the radial lengths, the axial lengths, and element materials on adopted model. The simulated QHA has far-field radiation pattern in the upper hemisphere with maximum gain of 4.14dBi at 0o and omnidirectional coverage, half-power beamwidth of 140o, bandwidth of 6.5MHz, and VSWR of 1.13. The implemented QHA has major lobe in conformity with the simulated QHA with maximum gain of 10.75dB at 0o, and half-power beamwidth of 104o.
DEVELOPMENT OF QUICK RETURN MECHANISM FOR EXPERIMENTATION USING SOLIDWORKS
NURUDEEN OLATUNDE ADEKUNLE(1), KOLAWOLE ADESOLA OLADEJO(*2), ISMAILA OLASUNKANMI SALAMI(1), ADEWALE OREOLUWA ALABI(1)
Quick Return Mechanisms (QRMs) are one of the essential accessories used in machine tools which involve reciprocating cutting action with a quick return stroke and a constant angular velocity of driving crank. The aim of this work was to simulate, design and construct a prototype of a QRM that can be used for demonstration and instrumentation. The QRM was simulated using Solidworks and a prototype was developed from the simulated results. The experiment was conducted using the prototype. The kinematic simulation of the Solidworks model was compared with the kinematics of motion of the prototype. The result showed that the Percentage Stroke Length error was 0.36%. It was observed that, there was no significant difference in the simulated and experimental results, hence, the prototype can be used for demonstration and experimentation to assist students in understanding basic principles of the machine operation.
DEVELOPMENT AND APPLICATION OF A COMPUTER PROGRAM FOR FOUR-BAR LINKAGE AND SLIDER-CRANK MECHANISMS
OLADEJO KOLAWOLE ADESOLA(*1), ADEKUNLE NURUDEEN OLATUNDE(2), ADETAN DARE(1), ABU RAHAMAN(3), ORIOLOWO KOLAWOLE TAOFIK(4)
Complex mathematical problems have been solved with the aid of software application to obtain reliable results. The positional kinematic analysis of a slider crank mechanism involves computation of the motion parameters: linear displacement, velocity and acceleration of the slider; and angular velocity and angular acceleration of the connecting rod for every 300 variation of the crank angle. This study aimed to develop a customized software which can be used to efficiently analyse a given design of a four-bar and a slider-crank mechanisms. A program was written using VB (Visual Basic) programming language for the equations of angular velocities and angular acceleration of the coupler and follower for the four-bar linkage and the linear velocity and acceleration of the piston for the slider crank mechanism. The program was tested with different parameters for the mechanisms and the solutions compared with the results from manual calculations. The findings revealed that there were no differences (p ≤ 0.05) between the results using the program and manual calculations, which imply the accuracy of the program. It can be concluded that the program could be used to solve problems of four- bar linkage and slider-crank mechanisms.
ELECTRICAL LOAD RELIABILITY ASSESSMENT USING ANALYTICAL METHOD, CASE STUDY: FUPRE 1 X 2.5MVA INJECTION SUBSTATION
AMAKIRI OKILO FRIDAY(1), OSHEVIRE PATRICK(*1)
This research work presents the reliability assessment of electrical load distribution system in Federal University of Petroleum Resources, Effurun (FUPRE), Warri using the Analytical method and ETAP software as the simulation tool to run the reliability assessment of the System. The analytical analysis was conceded out by using August 2018 – August 2019 historical data of Tetfund Classrooms Blocks, Hostels, College of Technology, Administration Block, Health Center, and College of Science Feeder obtained from the Benin Electricity Distribution Company [BEDC]. The results conceded revealed that College of Technology Injection Substation is the most reliable in the distribution network when compared to the other five substations around the institution premises as it recorded system indices of ASAI: 99.30, SAIFI: 1.10, SAIDI: 55.35, CAIDI: 123.04 in August 2018 to August 2019. Nevertheless, the total reliability indices of the six substations under investigation as obtained from the analysis, and it shows that availability of power to FUPRE distribution is very poor as compared with the benchmark of IEEE ASAI of 99.99 for distribution substation availability.
STUDY OF PHYSICOCHEMICAL AND MICROBIOLOGICAL QUALITY OF THE SPRING WATERS OF THE REGION OF OUM TEBOUL WILAYA OF EL TARF- ALGERIA
SABRINA BOUCHELAGHEM(*1), SAMIA MOUISSI(1), CHAIMA BENZERAA(1), ROUMAISSA KHALFOUN(1)
The present work aims to assess the physico-chemical and microbiological parameters of the waters of the three sources (Ain Bergougaya, Ain Sigleb and Siporex) in the region of Oum el Teboul wilaya of El Tarf. Parameters such as temperature, pH, conductivity and salinity were measured in situ with a field multimeter. Hardness (62 mg/L to 266 mg/L), salinity (0.01 to 1 mg/L). From a microbiological point of view, there has been no evidence of the complete absence of germs of contamination such as total coliforms and fecal coliforms. This study compared to the drinking water standards shows that the waters in the area studied are of good quality.
COMPARATIVE ANALYSIS OF THE FOAM GLASS GRAVEL TYPES EXPERIMENTALLY PRODUCED BY MICROWAVE IRRADIATION
FELICIA COSMULESCU(1), LUCIAN PAUNESCU(*2), MARIUS FLORIN DRAGOESCU(2), SORIN MIRCEA AXINTE(2,3)
The paper presents an unconventional technique for manufacturing foam glass gravel. The numerous experimental results obtained by the authors in the last year using various manufacturing recipes common in the world industrial production by conventional techniques were selected and subjected to a qualitative and energy efficiency comparative analysis, aiming to determine the best foam glass gravel manufacturing procedure under the conditions of the use of the microwave energy. The optimum recipe was composed of 83% glass waste, 1 % glycerol, 8 % sodium silicate and 8 % water. The maximum heating temperature reached 823 ºC with a very economical energy consumption of 0.88 kWh/kg. The sample characteristics were apparent density-0.24 g/cm3, porosity-89.1% with pore size between 0.3 - 0.6 mm, thermal conductivity-0.063 W/m·K and compressive strength - 5.9 MPa, almost similar to those industrially obtained.
INTERACTIONS BETWEEN CETYLTRIMETHYLAMMONIUM OR TETRAMETYLAMMMONIUM BROMIDE AND MCl2 OR MCl5 (M = Hg, Cu, Zn, Co, Ni, Cd and Nb) IN MONONUCLEAR COMPLEXES: SYNTHESIS AND INFRARED STUDY
DAME SEYE(*1), ASSANE TOURE(1), CHEIKH ABDOUL KHADIR DIOP(1), LIBASSE DIOP(1)
On allowing cetyltrimethyl ammonium bromide (C19H42NBr) and HgCl2, CuCl2.2H2O, CoCl2.6H2O, ZnCl2, NiCl2.6H2O or NbCl5 in specific ratio in methanol, new mononuclear have been obtained and studied by infrared. The suggested structures are discrete, of infinite chain with octahedral or tetrahedral environments around the metallic centres. The MX2 behaves as discrete chains. For most of the structures, when intermolecular hydrogen bonds are considered, supramolecular architectures may be obtained.
CONSIDERATIONS CONCERNING THE EVALUATION OF TOWING FORCES FOR ROAD TRANSPORTATION OF AGABARITICAL MECHANICAL EQUIPMENT
RADU IATAN(*1), MIHAI STATESCU(2), ION DURBACA(1), GEORGIANA LUMINITA ENACHESCU(1)
The full safety of operating industrial mechanical equipment, in particular the over-sized ones, with a complex structure, is ensured by compliance with all necessary requirements, starting with design, fabrication, transportation from the supplier to the recipient and operation within the working parameters. The present article that is continuing the analysis of transportation stages of over-sized and heavy equipment, as can be seen from the attached bibliography, takes into consideration the evaluation of the towing forces, in the case of two distant platforms. The masses of the transported components, the characteristics of the roadways, as well as the character of the movement and the influence of the wind loads are considered.
ANALYSIS OF DOWNTIME IN A TYPICAL NIGERIAN MULTINATIONAL BOTTLING COMPANY
ABAFI JOEL(1), OKE ADEKOLA(*1)
Failure data were extracted from the report book of the case study company. These data were stratified and analysed.Data stratification was pivotal in the separation of failure data into smaller and more defined form based on a predetermined set of criteria. Filler system was found to have the highest percentage failure occurrences; hence a standby filler system became the best option. The study concluded that, although in a production/manufacturing system, downtime is inevitable but it can be limited to the planned downtime with respect to the typical Nigerian multinational bottling company.
EXPERIMENTAL INVESTIGATION OF A CONCEPT WAVE ENERGY CONVERTER FOR HARNESSING LOW AMPLITUDE SEA WAVES
OLAKUNLE KAYODE(*1), TITUS OLUWASUJI AJEWOLE(2), OLUFEMI ADEBOLA KOYA(3)
This paper presents the results from experimental validation of numerical simulation of a concept wave energy converter for low amplitude sea waves. The device was conceived to contain a wave amplifying device (WAD) to magnify the wave height of incident waves while point absorber buoy(s) efficiently harness the wave energy for electricity production. The validation results show that the optimum aperture angle for the WAD is 45±2 degree, and wave height magnification of 170% is possible. The optimal buoy shape for the device was confirmed as concave wedge buoy. The combination of the two in a single device shall make economical the harnessing of low amplitude waves.
STUDY ON THE INFLUENCE OF WELDER’S FATIGUE ON THE QUALITY OF WELD LINES
DIANA LUNGU(1), CAROL SCHNAKOVSZKY(1), ALEXANDRU ACSINTE(1), EUGEN HERGHELEGIU(1), CRINA RADU(1)
In this paper a case study is presented, based on certain exercises applied to different welders, to evaluate the influence of welder’s fatigue on the quality of welding. The performed test was aimed at evaluating the technical performance (the welding act) of subjects, as well as the accuracy of weld lines. Five modules of exercises were applied. The exercises of each module were various, they were of medium level, so that they were neither overburdened, nor unsolicited, because both situations could lead to accidents due to fatigue. A weld line was performed after each exercises’ module. The visual quality of welding was appreciated according to the EN ISO 17637:2011 standard.
A SYSTEM DYNAMICS MODEL TO DETERMINE THE VALUE OF INVENTORY HOLDING COST
BABATUNDE OMONIYI ODEDAIRO(*1), EMILOLA HELEN ALABA(1), INYENEOBONG EDEM(1)
Traditionally, Inventory Holding Cost (IHC) is assumed to be a combination of several costs and determined by the summation of these cost components. Several authors have suggested that the value of IHC ranges between 12-50% of the procurement cost of an item. However, due to the absence of a generally acceptable methodology, many practitioners still determine this percentage based on estimates, benchmarks and intuition. Giving considerations to this reality, a mathematical model to determine the value of IHC using systems dynamics approach was developed. IHC was viewed holistically to identify relevant quantities, their interactions (static or dynamics), behaviour and consequences. A Causal Loop Diagram (CLD) was developed to establish the relationship among these quantities. Thereafter, CLD was transformed into a Flow Diagram (FD). FD was used to formulate a set of systems dynamics equations to obtain IHC. The interaction among fraction of goods ordered per month (FOM), fraction sold per month (FSM) and fraction damaged per month (FDM) was simulated to obtain percentage values of IHC. The value of IHC obtained from the model and simulation analysis ranges between 22.58-25.39% of the item held in stock. Based on these results, it is concluded that the developed model can be used for simulation and system analysis of the holding cost component of an inventory system under different contextual settings.
MODEL IDENTIFICATION AND LEVEL CONTROL OF COUPLED TANKS SYSTEM
OKUBANJO AYODEJI(*1), OKANDEJI ALEXANDER(2), ALAO PETER(1), OLALUWOYE OLAWALE(1), ONAIFO FRANK(1), MUFUTAU OLAYEMI(3)
The Couple Tank (CT) system remains as a benchmark to investigate and test new emerging control schemes in the process industry since its dynamic emulates many factual system in the field of process control. In this paper, we examine the performance evaluation of two control algorithms, proportional derivative controller (PD) and proportional-integral-derivative controller (PID). The dynamics of the CT system is experimentally derived by system identification method and validated with a mathematical model that depicts the dynamic behaviour of the coupled tank system. Furthermore, the control schemes are expanded on the model obtained through system identification method. The simulation results showed that the PD controller did not meet all the specified control objectives. To improve the response an integral controller was incorporated to the PD controller and the response was compared to that of the PID controller and uncompensated system. The results revealed that the PID controller satisfied all the control goals. However, the PD controller was more satisfactory in terms of time response criteria.
OPTIMIZATION OF DOUBLY REINFORCED BEAM DESIGN USING SIMULATED ANNEALING
SIMON OLAYIWOLA ADEREMI OLAWALE(1), OLUTOSIN PETER AKINTUNDE(*1), MOSES OLADIPUPO AFOLABI(1), OLUWOLE AKINYELE AGBEDE(1)
The optimization of the doubly reinforced concrete beam was investigated in this paper using the simulated annealing. Materials costs are considered as the objective function. The variables are the width, depth, compression steel, tension steel and cost. The constraints are the ultimate moment of resistance, compression/tension-steel ratio, minimum and maximum area of reinforcements. At the concrete compressive strength of 25 MPa, it is demonstrated that simulated annealing method can be used to optimize the design of concrete beams.
A FLUID FLOW ANALYSIS OF A JET EJECTOR SYSTEM USED IN INDUSTRIAL APPLICATIONS
OLARU IONEL(*1)
Many studies have been conducted for jet ejectors used in the recovery of solar energy or for their use in refrigeration systems for various industrial applications. Generally, these types of ejectors are using water as the working fluid because water have a low cost, a chemical stability and is safe to use. Naturally, other refrigerants, with large-scale application for industry, can be used. In such a type of jet ejector, besides selection of the refrigerant, the design of ejector is very important, with strongly influence to the performance, because the compression ratio depends on the geometry of the nozzle and on the geometry of the diffuser. Compared to other refrigeration systems, those with ejector have some advantages: simplicity in construction, high liability and low cost. However, it has a coefficient of performance lower than conventional systems, this limited the widespread application of ejector refrigeration systems.
PHYSICO-MECHANICAL PROPERTIES OF WOOD AND NON-WOOD PLASTER OF PARIS BONDED COMPOSITE CEILING BOARDS
TEMIDAYO EMMANUEL OMONIYI(*1), KAYODE AYODELE AJOBIEWE(1)
The effects of wood and non-wood fibres reinforcement on the properties of Plaster of Paris were evaluated. The woody and non woody residues were varied in 10, 20, 30, 40, and 50 % of the whole mix while the Plaster of Paris used was in the ratio 100 (control), 90, 80, 70, 60, and 50 %. The mean density of the composite produced is 3250 kg/m3. The mean thickness swelling and water absorption after 2 and 24 hours were 0.84 % and 0.88 %, and 13.8 % and 16.2 % respectively. The MOR and MOE increased with increase in fibre content hence the composite is suitable for indoor applications.
TECHNO-ECONOMIC ASSESSMENT OF TRANSFORMING SORGHUM BAGASSE INTO BIOETHANOL FUEL IN NIGERIA: 1 - PROCESS MODELLING, SIMULATION, AND COST ESTIMATION
AJAYI OLUFUNMILOLA OYENIKE(1), ONIFADE, KOLAWOLE RASHEED(2), ONADEJI ABIODUN(3), OYEGOKE TOYESE(*2, 4)
Apart from the environmental threats posed by fossil fuel due to emissions of greenhouse gases (majorly CO2), Nigeria's economy's continuous reliance on only one source of fuel production is unsustainable, hence, the need to consider diversification and alternative sources of energy generation and fuel production. This work aims to model and simulate the process of transforming sorghum bagasse into a fuel grade bioethanol via the use of Aspen HYSYS and MATLAB for the development and evaluation of cost implications and demand of the concerned plant studied. The study of process plant models shows that 189 g of fuel grade bioethanol will be obtainable from a kilogram of sorghum bagasse based on the condition employed in the modeling of the process. Cost analysis indicates that it would require a capital and operation cost worth of $1.92 and $ 0.83, respectively, to produce a liter of fuel grade bioethanol from sorghum bagasse.
AN OVERVIEW OF NANOELECTRONICS AND NANODEVICES
OYUBU AKPOVI OYUBU(*1), OKPEKI UFUOMA KAZEEM(1)
Nanoelectronics is a nascent area of making electronic devices at the atomic scale to utilize small-scale 'quantum' characteristics of nature. As the name suggests, Nanoelectronics refers to employing nanotechnology in building electronic devices/components; especially transistors. Thus, transistor devices which are so small such that inter-atomic cooperation and quantum mechanical characteristics cannot be ignored are known as Nanoelectronics. This article presents Nanoelectronics and Nanodevices, which are the critical enablers that will not only enable mankind to exploit the ultimate technological capabilities of electronic, mechanical, magnetic, and biological systems but also have the potential to play a part in transforming of the systems thus giving rise to new trends that will revolutionize our life style.
FOAM GLASS GRAVEL MADE OF RECYCLED GLASS WASTE AND SILICON CARBIDE BY MICROWAVE HEATING
LUCIAN PAUNESCU(*1), MARIUS FLORIN DRAGOESCU(1), SORIN MIRCEA AXINTE(1,2)
The paper presents recent achievements in the microwave use for manufacturing foam glass gravel from recycled glass waste and silicon carbide. The aim was to obtain a product with physical and mechanical characteristics almost similar to those of industrially manufactured materials by conventional heating techniques, but with a higher energy efficiency. A foam glass with the thermal conductivity of 0.075 W/m·K and the compressive strength of 7.5 MPa was experimentally obtained. The specific energy consumption was of 1.0 kWh/kg comparable with the industrial processes and it could reach values up to 25% lower by using a high power industrial microwave equipment.
ASSESSMENT OF MALIR RIVER WATER QUALITY AND IT SUITABILITY FOR IRRIGATION PURPOSES
MUHAMMAD SALEEM(*1)
Malir river, which is passing through industrial area of mega city Karachi is assessed for the suitability of its water for irrigation purposes. It was found that the concentration of studied metals is a function of position and season. Most of the pollutants are within the limits provided by national and international standards however, nickel was above the allowable limit for irrigation water quality (1000 μg/L) which is probably attributed to the discharge of effluent from vegetable-ghee manufacturing factories working in the vicinity. The overall suitability of Malir river based on EC, TDS and SAR is ranked’Permissible’ for irrigation.
FORMULATION OF CONCRETE BASED ON PLANT MATERIALS (CASE OF RICINODENDRON HEUDELOTII: AKPI): OPTIMIZATION OF THE PROPORTION OF SHELLS
MAMERY ADAMA SERIFOU(1), SOULEYMANE OUATTARA(1), BRAHIMAN TRAORE(*1), CONAND HONORE KOUAKOU(1), EDJIKEME EMERUWA(1)
The aims of this work is to study the influence of the partial substitution of natural aggregates by the nut shells of Ricinodendron heudelotii known as AKPI, on the physical-mechanical properties of concrete. The substitution rates made are 5%, 10% and 15%. Test results indicate that the presence of Akpi nut shells (ANS) causes increased porosity and reduced compressive strength of concrete. Increasing of porosity and decreasing of strength become important when the quantity of shell increases in concrete. However, the kinetics of hardening at a young age of the concrete is improved from 1% to 7%.
MATHEMATICAL MODEL OF RESOURCE-SAVING PRODUCTION TECHNOLOGY OF BAKED GOODS WITH AMARANTH FLOUR
ANASTASIA SHISHKIN(1), MADINA SADYGOVA(*1), MARIA BELOVA(1), TATYANA KIRILLOVA(1)
Amaranth is a promising raw ingredients enriching bakery products, in the work used grade “Flight” Saratov breeding. The article discusses the effect of amaranth flour and the type of liquid that goes into the dough baking on the baking properties of the semi-finished product and the quality of the finished products from wheat flour with a satisfactory quality gluten. The moisture, acidity, porosity, structural and mechanical properties, gas-forming ability, lift and fermentation activity were investigated. For the manufacture of comparable samples used wheat flour, presented on the market of Saratov. Amaranth seeds of the variety “Flight” in the amount of 7, 10, 15 and 20 %. Analysis of the effect of amaranth flour on the structural and mechanical properties of the dough showed that adding 7% or more of amaranth flour significantly reduces the spreading of the dough. The index of fermentation activity of semi-finished products with the share of amaranth flour 20%, 15%, 10% and 7% was significantly higher than the control, at the beginning of fermentation. The introduction of amaranth flour in an amount of 7 to 20 % had a significant impact on the gas-forming ability of the wheat-amaranth dough and was characterized by an intense, “explosive” beginning of fermentation and a fairly rapid decline in fermentation intensity over time, especially in a sample with a share of amaranth flour 7 %. Kneading on goat milk whey had a positive effect on the studied parameters. According to the research results, the expediency of using flour from amaranth variety Flying in the technology of bakery products made from wheat flour with a satisfactory weak gluten in quality to give them functional properties has been proved. Based on the mathematical model, the optimal parameters of the process are determined: the amount of amaranth flour in the recipe for buns is 15 %, fermentation time - 85 min, dough kneading liquid - goat milk serum.
DESIGN AND FABRICATION OF AN ELECTRICALLY POWERED MAIZE PLANTER
BABATUNDE OLUWAMAYOKUN SOYOYE(*1)
The correct application of production inputs for environmental and agricultural production sustainability is a key to successful production of maize. An electrically powered maize planter was designed and fabricated. Light reflecting optoelectronic field counter capable of detecting free falling object with equivalent or greater than 0.7 mm distance in planter delivery tube was designed and built to monitor seed drop on the planter. The device accurately counted the falling seeds with the planter forward speed of 1.38 m/s and seed delivery tube of 24 mm. The average number of two seeds was discharged per hole.
CRYSTAL STRUCTURE OF TRIPHENYLTIN (IV) FORMATE POLYMER, (HCO2SnPh3)n
MODOU SARR(*1), MOUHAMADOU BIRAME DIOP(1), AMINATA DIASSE-SARR(1), AI WANG(2), ULLRICH ENGLERT(2)
The title polymer [HCO2Sn(C6H5)3]n was isolated by serendipitous from reaction in ethanol 96 % between bis-(monocyclohexyl ammonium) 2-carboxyethyl hydrogen phosphonate, {(CyNH3)2[CO2CH2CH2PO2(OH)]} and triphenyltin chloride, SnPh3Cl. The polymer crystallizes in the monoclinic space group P21/n with Z = 4, a = 14.7091 (18) Å, b = 15.4133 (19) Å, c = 14.7639 (18) Å, β = 94.242 (2)° and V = 3338.0 (7) Å3. The structure consists of an infinite chain propagating along the crystallographic a-axis direction with bidentate formate anions. The O2SnC3 core is organized into a trans-trigonal bipyramidal like-arrangement.
SYNTHESIS AND INFRARED STUDY OF SOME PHENYLPHOSPHONATE, DIPHENYLPHOSPHINATE AND ACETATOPHOSPHONATE NEW ORGANOTIN (IV) DERIVATIVES AND ADDUCTS
MODOU SARR(*1), AMINATA DIASSE-SARR(1), LIBASSE DIOP(1)
Three organotin (IV) derivatives PhPO3HSnBu2Cl, SnBu2Ph2PO2Cl·3/2H2O, Sn(PhPO3)Cl2·2H2O obtained on allowing PhPO3H2 or propylammonium PhPO3H to react with SnBu2Cl2, SnCl2·2H2O and two adducts [(C6H5CH2)2NH2]3O2C(CH2)2PO3·3SnPh3Cl, [CyNH3(HO2POCH2-N(CH2CO2H)2]2·3SnCl4.2H2O·NH4Cl obtained on allowing (C6H5CH2)NH2)3O2C(CH2)2PO3 or [CyNH3(HO2POCH2-N(CH2 CO2H)2]2 and SnPh3Cl or SnCl2·2H2O to react in ethanolic media have been characterized by elemental analyses, infrared and Mossbauer techniques. The suggested structures, while considering the anionic counterpart, are discrete, dimeric, double and triple metallic components or of infinite chain types, the anion behaving as a monochelating, a bichelating or a bidentate ligand. In OH containing structures, when extra hydrogen bonds are considered, supramolecular architectures may be obtained.