Volume 27, No. 1 (2021)
Articles
THE EFFECT OF RAW MATERIALS ON SOME PHYSICAL PROPERTIES OF OSUN STATE CERAMIC TILES
OLURANTI ABIOLA(*1), ADEKOLA OKE(2), BABATUNDE OMIDIJI(2), DARE ADETAN(2)
The study evaluates the effect of ceramic raw materials on the physical properties of ceramic tiles with a view to determine the tiles with the best material blend. Ten different blends of clay – feldspar – silica was used to produce ceramic samples. The results show that sample with 60 % clay, 30 % feldspar and 10% silica have the best water absorption (10.43%) and apparent porosity (22.77 %); while sample with 60 % clay, 20 % feldspar and 20 % silica exhibits the highest apparent relative density of 2.79. Sample with 50 % clay, 40 % feldspar and 10 % silica possesses the best bulk density of 1.43 g/cm3. Conclusively, the ceramic sample produced can be useful in the production of wall tiles.
SIGNIFICANT LEVELS OF STEEL SLAG CONCRETE PRODUCED WITH VARYING WATER CEMENT RATIOS
SOLOMON IDOWU ADEDOKUN(1), MUKAILA ABIOLA ANIFOWOSE(*2), SAMSON OLALEKAN ODEYEMI(3), JOHNSON ROTIMI OLUREMI(4)
This study investigated the significance of steel slag concrete created with varying water cement ratios. Steel slag from Prism Nigeria Limited was used to replace granite (at 0, 40, 50 and 60 %) in concrete. Properties of this modified concrete were examined and its results were exposed to measurable test utilizing Analysis of Variance (ANOVA). The outcome indicated that the compressive and flexural qualities of the concrete increased with increased in slag content but consistently decreased as the water-cement ratios increased. The p-values of the ANOVA test for the models term are significant because they are less than 0.05.
DEVELOPMENT OF A MULTI-OBJECTIVE PRODUCTION PLANNING MODEL FOR A SAWMILL
SEGUN ABIODUN ALONGE(*1), CHRISTOPHER OSITA ANYAECHE(1)
Based on the objectives set out for a Sawmill, a goal programming model was developed to simultaneously consider the production volumes goal, sales revenue goal, production cost goal, and machine utilization goal in order to develop its production plans for a horizon. The unwanted deviations from the goals served as the objective function to be optimized subject to the goals constraints, operational constraints, and non-negativity constraints. Three independent pre-emptive goal priority structures, GP1, GP2, and GP3, were considered with each prioritizing the objectives differently. The goal programming model was tested for its utility using data gathered from the mill to the three-goal priority structures. The results obtained indicated that, for GP1, the product volume goals for all products were achieved, and all but one, volume goals were achieved for both GP2 and GP3. The viability test showed that all priority structures used were profitable with GP1, GP2, and GP3 recording 1.099, 1.102, and 1.095 respectively. This indicates that the three priority structures considered are approximately profitable at the same level. The goal programming model for production planning offers the decision-maker a variety of options as to its application.
OBTAINING NEW THIN WALLED TUBULAR STRUCTURES THROUGH MATRIX MORPHOLOGICAL RESEARCH
VLAD ANDREI CIUBOTARIU(*1), CRINA MARIA RADU(1), COSMIN GRIGORAȘ(1), EUGEN HERGHELEGIU(1)
New products based on a structure that represents a combination of known elements in a higher quality set, as well as products that refer to new shapes, new curves, new surfaces can be obtained logically - analytically - deductively or by methods specific to the optimal calculation. The present paper focuses on the method of analyzing tridimensional morphology, some possible solutions being evaluated on value criteria. Of course, these methods can be applied in the field of engineering with very good results. The focus of this study is to obtain new thin walled tubular structures - such as car crash members - which in the case of axial shock loads have a higher predictable behavior compared to those already used in various technical fields. Following the study, it can be said that depending on the amount of absorbed energy in the case of axial collisions and the absorption of kinetic energy developed at the time of impact, the optimal crashworthiness solution could be tubular structures with a circular support base and rectangular deformable area for impact.
FORCES AND DISPLACEMENTS DISTRIBUTION AFTER FEM ANALYSIS OF VIBRATORY WORKING TOOL
NELUS-EVELIN GHEORGHITA(*1)
The research status and the study of vibratory working tools used in tillage operations are discussed in this paper. At this moment, one of the most critical issues for the engineers and manufacturers is to achieve the highest efficiency with the least resources needed. Various studies by researchers on vibratory working tool styles and models have been taken into account. A study was then conducted to ascertain the advantages of vibratory equipment over rigid equipment. A finite element process study was also conducted on one active working tool to observe specific deformations and displacements. Draft forces ranging from 440 to 750 N were used in the study. According to prior studies, the angle of attack after the forces have been applied should not exceed 80 degrees.
THE EFFECT OF PACKAGING TYPE AND STORAGE TEMPERATURE ON THE SHORT TERM STABILITY OF ELECTROLYTIC CONDUCTIVITY REFERENCE MATERIALS
AYU HINDAYANI(1), OMAN ZUAS(*1), NURYATINI HAMIM(1)
In this work, monitoring the effect of packaging type and storage temperature on the short term stability of calibration standard solution KCl 1 M were conducted. The KCl 1M were packaged in two types of packaging i.e., high-density polyethylene (HDPE) and glass bottle. The effects of packaging type and storage temperature were monitored for four weeks at 25 °C and 40 °C. The conductivity values of KCl 1 M in the HDPE and glass bottle were 111.61 mS/cm and 111.62 mS/cm, respectively. The results indicated that the KCl 1M solution at 25 °C in both HDPE and glass bottle were found to be good in short term stability and there was no significant different between the two packaging types. At temperature of 40 °C, however, short term stability of the KCl 1 M in a glass bottle was better than the HDPE bottle.
INTELLIGENT LIQUID LEVEL CONTROL OF A COUPLED NONLINEAR THREE TANK SYSTEM SUBJECTED TO VARIABLE FLOW PARAMETERS
MUSTEFA JIBRIL(1), MESAY TADESSE(*1), NURYE HASSEN(1)
In this paper, an intelligent control system technique is proposed to model and control of a nonlinear coupled three tank system. Two pumps fed the tank 1 and tank 2 and a fractional flow of these two pumps fed tank 3. The main aim of this paper is to make a set point tracking experiments of the tanks level using a nonlinear autoregressive moving average L-2 (NARMA L-2) and neural network predictive controllers. The proposed controllers are designed with the same neural network architecture and algorithm. Comparison of the system with the proposed controllers for tracking a step and random level set points for a fixed and variable flow parameter and some good results have been obtained.
SOLID PARTICLE CHARACTERIZATION. SOME ASPECT RELATED TO THE SHAPE EVALUATION BY USING SOFTWARE CORRELATIONS
EMILIAN-FLORIN MOSNEGUTU(1), VALENTIN NEDEFF(1,2), ALEXANDRA-DANA CHITIMUS(*1), MARCIN JASIŃSKI(3), NARCIS BARSAN(1)
This article presents a method for determining the Riley circularity evaluation, a characteristic that defines the shape of a solid particle. To determine this parameter, a working methodology was identified by using Mathcad. To verify this methodology 15 anthracite particles were inserted in the working file, the shape of which is different, to determine the analyzed characteristic.
ASSESSMENT OF CARBON FOOTPRINTS OF A TYPICAL NIGERIAN TOWNSHIP POST OFFICE: A CASE STUDY OF KAFANCHAN DISTRICT POST OFFICE, KAFANCHAN, NIGERIA
RICHARD BALTHI MSHELIA(*1), FUNSHO BABARINDE(2)
This research work focuses on carbon footprinting the operations of a township post office in a developing country. The analysis was carried out in accordance with the Universal Postal Union’s guidelines for carbon accounting. The results showed that for the inventory year, the office’s carbon footprint was 13.3423 tonnes of carbon dioxide equivalent (CO2e). It was found that for each gram of parcel delivered, 0.0171 kgCO2e was emitted into the atmosphere. Results further showed that 82 % of emission is attributed to delivery of mails while 18 % is as a result of sorting and other minor activities within the facility.
AN ASSESSMENT OF THE DISPLACEMENT OF A CAM FOLLOWER USING REGULA FALSI METHOD
KOLAWOLE ADESOLA OLADEJO(*1), DARE ADERIBIGBE ADETAN(1), ADEKOLA OLAYINKA OKE(1), RAHAMAN ABU(2), GANIU AYOOLA LAMID(1)
Cam is a mechanical component that transforms circular motion to reciprocating motion by using mating component, called the follower. The principal aim of this work was to study and analyse the displacement of a cam-follower with Regula Falsi method and verify its input by using MATLAB and FORTRAN simulations. A study was conducted on angle of rotation and the displacement of the follower, which is equal to the radius of the cam given as transcendental equation to find the exact solution. The parameters such as initial guess, final guess, iteration counter and the desired displacement are involved in finding the angular displacement to the cam system in high speed rotation. The analysis was done using a computer programming that enables verification of the results obtained and ascertaining whether the inputs are correct or not for the displacement in cam follower system. The computer output showed results of the two data sets that yielded solutions and two that did not. The results revealed that the programme could be used to find the angular displacement corresponding to a given follower displacement for any cam; if the function CAMF is modified to include the appropriate radius function, r(x). The results further revealed that at a halve cycle of a rotating cam, which is equivalent to (x = 3.142 rad), is a solution that would provide the desired displacement of the follower (opening and closing of valves).
DAYLIGHT INVESTIGATION IN CAMPUS LECTURE THEATERS. CASE STUDY: SOUTH WEST COAST UNIVERSITY OF NIGERIA
OYELEYE OLAYINKA(*1), MAKANJU TOLULOPE(1)
Appropriate day lighting design saves lighting power energy (LPE) and reduces LPE cost. This research investigates daylight contribution of in selected north campus lecture theaters in a South West Coast University of Nigeria. TES 1332A lux meter was used for lux level determination. The window area to wall area (AWD to AW) ratio was determined using reliable algorithms. In the three studied buildings, the daylight contribution varies from 12 lux to 3803 lux; AWD to AW varies from 14 % to 22 % to 37 %; 22 % AWD to AW is considered moderate while 37 % AWD to AW is considered more suitable in the studied buildings.
INVESTIGATING POINTS-OF-GENERATION POWER LOSSES ON THE NIGERIAN NATIONAL GRID FOLLOWING UNBUNDLING OF THE ELECTRIC UTILITY INDUSTRY
AJEWOLE TITUS OLUWASUJI(*1), OLABODE OLAKUNLE ELIJAH(2), OKAKWU IGNATIUS KEMA(3), EGBEDINNI OLAKUNLE FEMI(4)
Aside from the domino effects of being radial in structure, the Nigerian national electric grid is currently suffering from deteriorated infrastructures and unpredictable fuel supply for power generation. Massive introduction of green energy-based microgrid alternatives has been proposed as a major means of resolving the challenges. Such paradigm shift needs to be substantiated within the context of the present situation of the grid, for the consumption of policy makers and implementers, hence; the performance of the generation sub-system of the grid in the post-deregulation era is evaluated in this study. Two-year numerical data on the operational capacities of the twenty-nine power plants that are currently connected to the grid are employed to profile the behaviours of the plants over the period. Yearly averages of the three operational capacities of each plant are estimated, and by comparing the respective capacities, generation losses are computed for each of the plants. With 5,063.8 MW yearly average generation capacity in the year 2018, a loss of 61.02 % was experienced on the sub-system; while the generation loss was 61.55 % in the year 2019 that has yearly average generation capacity of 5,062.5 MW. For the two years combined, the average generation capacity is 5,063.2 MW at 61.36 % power loss. These estimations reveal that the pre-deregulation loss profile of the generation sub-system has not been curtailed despite the unbundling of the electric power industry. Generation loss has rather persisted and keeps taking a heavy toll on the electric utility market of the country. Significant deployment of renewable electricity microgrid is therefore required to provide enduring solution.
MICROWAVE MANUFACTURE OF GLASS FOAM BY COMBINED USE OF GRAPHITE AND CALCIUM CARBONATE AS FOAMING AGENTS
LUCIAN PAUNESCU(*1), SORIN MIRCEA AXINTE(1,2), MARIUS FLORIN DRAGOESCU(2), BOGDAN VALENTIN PAUNESCU(3), FELICIA COSMULESCU(4)
The paper presents experimental results obtained in the manufacturing process of high-strength glass foam by combined use of two solid foaming agents (calcium carbonate and graphite) in variable weight ratios. The originality of the work is applying the unconventional microwave heating method, unlike the conventional techniques currently used in similar industrial processes. The optimal experimental variant, composed of 89.1 % glass waste, 0.9% calcium carbonate, 1 % graphite and other additives, was sintered at 828 ºC with a very low energy consumption (0.73 kWh/kg). The main characteristics of the optimal product were apparent density of 0.39 g/cm3, thermal conductivity of 0.088 W/m·K and compressive strength of 3.6 MPa, being usable in fields that requires resistance to mechanical stress and relatively difficult environmental conditions.
OPTIMIZATION OF THE MICROELECTROMECHANICAL PROPERTIES OF HEAT EXCHANGE SYSTEMS THROUGH MICROCHANNEL TECHNOLOGY
SARDER SHAMIR SHAKHER(1), KWADWO OSEI BONSU(*2)
Performance of microchannel heat exchangers is highly dependent on their geometry and shape. Hence, the structural design is as equally important as the material components. This paper expounds the development and applications of microchannel technology thereby proposing an optimal applicability on the microelectromechanical properties of heat exchange systems.
GREY WOLF OPTIMIZER BASED OPTIMAL PLACEMENT OF MULTIPLE FACTS DEVICES IN THE TRANSMISSION SYSTEM UNDER DYNAMIC LOADING SYSTEM
YUSUF SAMUEL SUNDAY(*1), OKORIE PATRICK UBEH(1), ABUBAKAR ADAMU SAIDU(1), ALHASSAN FAHAD(1)
The application of grey wolf optimization technique for multiple FACTS placement is presented in this paper for the reduction of total system losses and minimization of voltage deviation via optimal placement of Flexible AC Transmission System (FACTS) device. Grey wolf optimization (GWO) technique is inspired by social hierarchy and hunting behaviour of wolves and offers a right balance between exploration and exploitation during the search for global optimal. Series-shunt FACTS device; unified power flow controller (UPFC) is considered as a formidable device that can provides an alternative option for the flexible controllability and improvement of power transfer capability of a transmission lines. The analyses were conducted by increasing the number of UPFC in the network in order to evaluate the optimal number of FACTS devices that would give the least loss under maximum loading and contingency conditions. The efficacy of this proposed technique is demonstrated on 31-bus, 330 kV Nigeria National Grid (NNG) using MATLAB environment. The results show that optimal placement of FACTS device along with optimization technique provides a promising solution to the high power loss and voltage deviation bedevilling Nigeria National Grid.