Faculty of Engineering

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A Comparative Analysis of the Well Performance of Vertical, Horizontal and Multilateral Well
(Petroleum and Coal, 2019) Ameena A. Gaji; Petrus Nzerem; Oghenerume Ogolo; Ikechukwu Okafor ; Ternenge Joseph Chior
The demand for energy in the world has been ever increasing. Conventional technologies are being replaced gradually by different new technologies. Horizontal wells and multilateral wells have proved to be highly beneficial by improving production rates significantly. This study focuses on investigating the well performance of vertical well (Well V), horizontal well (Well H), and multilateral well (Well M) in the Hurricane field using PROSPER software. PVT matching, well modelling and well performance analysis was carried out. Sensitivity analysis was performed on key parameters such as tubing diameter, water cut, wellhead pressure and tubing roughness to determine their effects on well productivity. It was observed that increasing the water cut decreased the production rates of Well V, Well H and Well M by 41%, 36.1% and 33.5% respectively. An increase in the tubing diameter improved the production rates, wellhead pressure had high impacts on the well performance while tubing roughness had a minimal effect on oil production. The optimum production rates of 21,622.5 STB/day, 28,653.6 STB/day and 29,800.9 STB/day for Well V, Well H and Well M respectively were achieved at reservoir pressure of 3500 psig, wellhead pressure of 400 psig, water cut of 5% and a 5.5 inches tubing diameter.
A COMPREHENSIVE REVIEW OF HYDRAULIC FRACTURING TECHNIQUES IN SHALE GAS PRODUCTION
(NJEAS, 2023-01-01) Umar Adekola; Abdullahi Gimba; Ayuba Salihu; Khaleel Jakada; Ikechukwu Okafor ; Petrus Nzerem; Joseph Chior; Oghenerume Ogolo; Khadijah Ibrahim
Shale gas has emerged as a significant source of natural gas due to advancements in hydraulic fracturing and horizontal drilling technologies. This extraction method has facilitated drilling and production activities in regions previously untouched by oil and gas development. Hydraulic fracturing, a well-stimulation technique suitable for low and moderate-permeability reservoirs, relies on the successful drilling of horizontal wells and the creation of multiple hydraulic fractures to ensure economic viability. While shale gas presents significant energy production opportunities, concerns have been raised regarding its environmental impact. To mitigate these risks and determine the most effective approach for shale gas extraction, alternative fracturing technologies are being investigated. Notably, a considerable number of perforation clusters in shale gas horizontal wells do not contribute to production, highlighting the potential for refracturing. Therefore, a comprehensive analysis is required to evaluate the performance of hydraulic fracturing and alternative fracturing technologies in shale gas wells, considering factors such as cost-effectiveness, environmental impact, and gas extraction efficiency. This article aims to evaluate the hydraulic fracturing technology's capability to enhance gas recovery in shale gas formations as well as its environmental implications. The focus of this research is primarily on the hydraulic fracturing technique employed in shale gas development, its production capability, and associated environmental concerns. Through a systematic evaluation, this study provided valuable insights into the potential of hydraulic fracturing in maximizing gas recovery while addressing environmental challenges in shale gas formations.
A comprehensive review of hydrogen production and storage: A focus on the role of nanomaterials
(The University of Edinburgh, 2022-05-20) Emmanuel I. Epelle; Kwaghtaver S. Desongu; Winifred Obande; Adekunle Akanni Adeleke; Peter Pelumi Ikubanni; Jude A. Okolie; Burcu Gunes
Nanomaterials are beginning to play an essential role in addressing the challenges associated with hydrogen production and storage. The outstanding physicochemical properties of nanomaterials suggest their applications in almost all technological breakthroughs ranging from catalysis, metal-organic framework, complex hydrides, etc. This study outlines the applications of nanomaterials in hydrogen production (considering both thermochemical, biological, and water splitting methods) and storage. Recent advances in renewable hydrogen production methods are elucidated along with a comparison of different nanomaterials used to enhance renewable hydrogen production. Additionally, nanomaterials for solid-state hydrogen storage are reviewed. The characteristics of various nanomaterials for hydrogen storage are compared. Some nanomaterials discussed include carbon nanotubes, activated carbon, metal-doped carbon-based nanomaterials, metal-organic frameworks. Other materials such as complex hydrides and clathrates are outlined. Finally, future research perspectives related to the application of nanomaterials for hydrogen production and storage are discussed.
A comprehensive review on the similarity and disparity of torrefied biomass and coal properties
(Elsevier, 2024-05-09) Adekunle Akanni Adeleke; Peter Pelumi Ikubanni; Stephen S. Emmanuel; Moses O. Fajobi; Praise Nwachukwu; Ademidun A. Adesibikan; Jamiu Kolawole Odusote; Emmanuel O. Adeyemi; Oluwaseyi M. Abioye; Jude A. Okolie
The use of coal for energy generation is facing serious scrutiny because of environmental concerns. As a result, there is a growing global interest in biomass, a renewable and readily available energy source. However, the utilization of biomass comes with significant drawbacks, including its heterogeneity, low bulk density, and calorific value. Biomass also has a low energy content, high moisture, poor grindability, and high volatile matter, which affect its handling, bulk transportation, and storage. Torrefaction technology has been employed in previous works to improve the properties of biomass for subsequent handling and transportation and for low-cost energy generation. Since coal is a promising precursor for energy generation, it is imperative to compare the physicochemical properties of coal with that of torrefied biomass. Therefore, this study aims to conduct a comprehensive comparison between various grades of coal and torrefied biomass. The review revealed that torrefied biomass could replace coal, as its properties are similar to those of coal, except for high-grade coals. The proximate and ultimate analyses of coals (lignite and bituminous) were found to be comparable to various torrefied biomass materials. The fuel ratio (0.5–2.0), and higher heating values (16,100–19,000 kJ/kg) of coal and torrefied biomass were within the range useful for coal-fired plants. Additionally, ash analyses, ash fusion temperature, hygroscopic tendency, functional group study, and microstructural comparison were reviewed in this study. The results from various studies have shown close similarities with only small disimilarities in the fuel properties between coal and torrefied biomass. Therefore, torrefied biomass is proposed as a complimentary feedstock to coal in various applications.
A COOLING POTENTIAL OF FORMULATED BIO-QUENCHANT OILS ON A CAST ALUMINIUM ALLOY MATERIAL
(Journal of Chemical Technology and Metallurgy,, 2020-02-02) Adebayo Surajudeen Adekunle; Adekunle Akanni Adeleke; Tajudeen Adelani Gbadamosi; Friday O. Nwosu; Jamiu Kolawole Odusote; Peter Olorunleke Omoniyi; Tajudeen O. Popoola; Kazeem Adekunle Adebiyi
The biodegradable vegetable oil based quenchants can serve as cooling media alternative to that of the toxic non-biodegradable petroleum based mineral oil in a heat treatment of aluminium and its alloy. 70 vol. % of edible vegetable oil are blended with 30 vol. % of Jatropha oil to form bio-quenchant oils for Aluminium (Al)-alloy probe treated at 500oC and soaked for 15 min in a muffle furnace. The cooling potential properties such as the cooling rate, the heat transfer coefficient, the Grossman quench severity and the biot number are investigated. The results obtained show that the blended bleached (BB) melon oil provides the highest cooling rate of 49.30oC s-1, while the blended raw (BR) palm oil ensures the lowest cooling rate of 18.45oCs-1. Heat transfer coefficients of 704.6 Wm-2K-1, 432.3 Wm-2K-1, and 394.4 Wm-2K-1 are exhibited by the blended bleached melon oil, the blended raw melon oil and the blended bleached groundnut oil, respectively. They are found higher than that of a petroleum based mineral oil, which amounts to 68.7 Wm-2K-1. The lowest heat transfer coefficient of 272.11 Wm-2K-1 is obtained in case of using a blended raw palm oil. The quench severity of the blended bleached melon oil, the blended raw melon oil and the blended raw groundnut oil refers to a Grossman H-factor of 1.01 m-1, 0.78 m-1, and 0.67 m-1, respectively. The latter values are higher than that obtained in case of a blended raw palm oil, which is equal to 0.37 m-1. However, the heat flow parameters obtained reveal that the blended bleached and the blended raw melon and groundnut oil can be characterized as fast quenching oils, while the blended bleached and the blended raw palm oil can be characterized as medium quenching oils of results comparable to and even better than those of the industrial petroleum based mineral oil.
A Model-Based Design of an Electric Kettle for Nigerian Households
(IEEE, 2024-08-15) Nwachukwu Praise; Ibikunle Rotimi; Adekunle Akanni Adeleke; Peter Pelumi Ikubanni; Seun Jesuloluwa; Onyemachukwu Chidindu
Electric kettles, essential in Nigerian households is the focus of this paper. It aims to develop and analyse discrete-time and continuous-time models using engineering software. First, a Computer-Aided Design (CAD) model is developed, followed by the comprehensive analysis of the steady-state thermal properties of the model using finite element analysis (FEA). Subsequently, a physical model, with three sub-systems, is developed and subjected to simulation. This study examines both models, scrutinizes the effect of alterations in thermal parameters, and conducts a comparative analysis with an actual kettle. The findings, offer valuable insights into the dynamics of the electric kettle and provide intuitive suggestions for enhancing its efficiency and usage.
A Review of Failure Analyses in Engineering: Causes, Effects and Possible Solutions
(IEEE, 2023-05-22) Temitayo Samson Ogedengbe; Ikumapayi Omolayo Michael; Adekunle Akanni Adeleke; Peter Pelumi Ikubanni; Adeiza Avidime Samuel
Failure analysis is centred on finding the reasons why machine parts lose functioning in an unintended way. In order to identify the damage's primary cause and ensure that it doesn't happen again, failure analysis investigation is necessary in determining the maximum amount of a specific type of load that may be applied to a structure without producing failure. It is frequently of interest throughout the design phase for engineering constructions. This provides the factor of safety against machine failure. This study is aimed at a review of failure analysis in recent times and as such 51 articles were reviewed, most of which were published no later than 2017. In this study, we critically examined and endorsed the idea of using failure as a methodological concept to foster creativity. Engineering-related operational methods, such as causes of failure, types of failure, possibility thinking, and reflexivity following failure, aided in reinforcing this educational study. We also made assumptions about potential design components for a technologically sophisticated failure assessment.
A Review of Rare Earth Ion-Doped Glasses: Physical, Optical, and Photoluminescence Properties
(Trends in Sciences, 2024-10-22) Serifat Olamide Adeleye; Adekunle Akanni Adeleke; Petrus Nzerem; Adebayo Isaac Olosho; Esther Nneka Anosike-Francis; Temitayo Samson Ogedengbe; Peter Pelumi Ikubanni; Rabiatu Adamu Saleh; Jude A. Okolie
Researchers worldwide have shown significant interest in doping glasses with rare-earth ions. This is particularly intriguing because rare-earth ions are extensively used to enhance the optical properties of host glasses, capitalizing on their unique spectroscopic characteristics due to optical transitions within the intra-4f shell. An in-depth review was conducted on various glass fabrication methods, such as sputtering, solgel, chemical vapor deposition, ion exchange, and direct melt quenching. The study emphasized the physical, optical, and photoluminescence properties of glasses made from glass formers co-doped with rare earth ions. Understanding the interrelationship between these properties is crucial for optimizing material performance across various technological applications. The research highlights the broad applicability of rare-earth-doped glasses in fields like white light emission, photonic devices, solid-state lasers, optical fiber communication, and biomedical applications
A Review of the Physical, Optical and Photoluminescence Properties of Rare Earth Ions Doped Glasses
(TRENDS IN SCIENCES, 2024-10-22) Serifat Olamide Adeleye; Adekunle Akanni Adeleke; Petrus Nzerem; Adebayo Isaac Olosho; Esther Nneka Anosike-Francis; Temitayo Samson Ogedengbe; Peter Pelumi Ikubanni; Rabiatu Adamu Saleh; Jude A. Okolie
Doping glasses with rare-earth ions have garnered significant attention among researchers worldwide. This interest stems from the widespread utilization of rare-earth ions to enhance the optical characteristics of host glasses and exploit the unique spectroscopic properties arising from their optical transitions in the intra-4f shell. Thus, this study reviewed the exceptional potential of rare-earth ion-doped glasses (REIs) in various applications such as solid-state lasers, photonic devices, communication optical fibers, and white light emission. Various methods for the fabrication of glass such as direct melt quenching, sol-gel, ion exchange, sputtering and co-doping techniques were reviewed extensively. The Specific focus was on the physical, optical and photoluminescence properties of glasses produced from glass formers co-doped with rare earth ions. The investigation centers on the comprehensive current applicability of REI-doped glasses. The review concludes based on the physical, optical and photoluminescence properties of rare earth ion-doped glasses that they are extremely useful in photonics, lasers, biomedical and optical communication applications.
A Review on Biomass Briquettes as Alternative and Renewable Fuels
(IEEE, 2023-02-28) Adekunle Akanni Adeleke; Petrus Nzerem; Ayuba Salihu; Esther Nneka Anosike-Francis; Adebayo Isaac Olosho; Etowa Emmanuel Obasesam; Sakeenah Sadiq Abubakar; Dakut John Yerima; Khaleel Jakada
The adverse effects of the combustion of fossil fuels on humanity and the environment have made it vital to discover eco-friendly, sustainable, and renewable energy alternatives. Globally, there exists loose biomass, which is agricultural and cultural waste that can be utilised to produce briquettes, a type of solid fuel. Briquettes have played a significant role in the energy generation economies of both developing and developed nations. The production of briquettes involves a series of activities, including collection, transportation, storage, processing, and densification of the feedstock to meet predetermined quality parameters. Rice husk, corn stalk, wheat straw, cassava stalk, groundnut shell, olive husk, palm kernel shell and coconut shell are among the feedstocks for briquettes. In order to increase the cohesive strength of the briquettes, binders are incorporated during the densification process. This study aims to investigate the current state of research regarding the utilisation of biomass-derived briquettes as a viable substitute for traditional fuels. To achieve this objective, a comprehensive analysis of recent literature published between 2017 and 2023 is conducted. This study encompasses essential subtopics, including the accessibility of biomass, the selection of binders, the parameters of the briquette process, and the equipment used for briquetting.
A Review on Extraction of Rare Earth Elements (REEs) From Coal Using Acid Leaching
(IEEE, 2023-11-01) Rabiatu Adamu Saleh; Abdullahi Gimba; Adekunle Akanni Adeleke; Adebayo Isaac Olosho; Taofeek Sunmonu; Petrus Nzerem; Ayuba Salihu; Chinomso Odimba
Coal has become a feasible source of rare earth elements (REEs; the 14 stable lanthanides, scandium, and yttrium). It is believed to contain significant amounts of rare earth elements, making it a primary source of REEs which serves as basic raw materials in the production of renewable energy. This review established the feasibility of recovering REEs from coal using acid leaching method. It discusses; the sourcing of REEs from coal, the applications of REEs and acid leaching as an effective hydrometallurgical method for extracting REEs from coal. It also examined the efficiency of methods used by other researchers in extracting REEs from coal. However, the potential of acid leaching as a solution to issues such as: difficult leaching conditions, low recovery and the use of expensive chemicals has not been fully investigated. For a better choice in the extraction of REEs from coal, more study and review are necessary.
A review on primary synthesis and secondary treatment of aluminium matrix composites
(Taylor and Francis, 2020-10-13) T. A. Orhadahwe; O. O. Ajide; Adekunle Akanni Adeleke; Peter Pelumi Ikubanni
In this paper, the primary synthesis and secondary treatment of Aluminium matrix composites (AMCs) has been reviewed. The renewed quest for component materials with high strength-to-weight ratio, unusual and superlative combination of properties for applications in automotive, aerospace, marine and warfare armoury manufacturing industries has increased the versatility potential of aluminium alloy-based composites. Several categories (synthetic and agro-based ceramics) of reinforcement materials for aluminium composite are discussed. The manufacturing/fabrication techniques which could be solid phase (powder metallurgy and rapid prototyping or 3 D printing method) or liquid phase (casting and pressure infiltration) methods are discussed in this review work. Secondary treatment such as heat treatment, forging and other thermomechanical treatments which improves the properties of as-synthesized composites are also discussed. A review synopsis of recent studies provides opportunity for concise but a more robust understanding of potential benefits and detrimental effects associated with the use of various primary synthesis routes and secondary treatment for manufacturing of ceramic reinforced AMCs. Despite the laudable research efforts that have been made towards development and enhancement of the properties of AMCs, this review work revealed that literature is very sparse on synergetic adoption of multi-synthesis route and multi-approach secondary treatment for producing AMCs. Sequel to the aforementioned unexplored research concept, some lacunae are identified and suggested for further elaborations and study.
A review on the use of carboxymethyl cellulose in oil and gas field operations
(Cellulose, 2023-09-17) Hauwa A. Rasheed; Adekunle Akanni Adeleke; Petrus Nzerem; Olusegun Ajayi; Peter Pelumi Ikubanni; Asmau M. Yahya
The purpose of this review is to highlight the applications of carboxymethyl cellulose (CMC) in oil and gas industries. CMC is one of the most promising cellulose derivatives and the most widely used in the drilling sector. Owing to its multifunctionality, facile, inexpensive, raw material abundance, availability, compatibility, distinctive surface property and many other disparate aspects, it is now widely used in many fields for a variety of applications, including the oil and gas industry, pharmaceuticals, food, textiles, wastewater treatment, and energy production/storage. Despite CMC’s wide applications in many fields, very few studies report its role in oil and gas operations such as drilling and completion, hydraulic fracturing, corrosion inhibition and cementing applications. As a result, this review points some of CMC’s relevance in the oil and gas industry now and in future.
Absorption, Diffraction and Free Space Path Losses Modeling for the Terahertz Band
(MECS, 2020-08-18) Petrus Nzerem; Oyeleke D. Oluseun; Idris Muhammad; Sadiq Thomas; Olabode Idowu-Bismark
With the explosive increase in the data traffic of wireless communication systems and the scarcity of spectrum, terahertz (THz) frequency band is predicted as a hopeful contender to shore up ultra- broadband for the forthcoming beyond fifth generation (5G) communication system. THz frequency band is a bridge between millimeter wave (mmWave) and optical frequency bands. The contribution of this paper is to carry out an in-depth study of the THz channel impairments using mathematical models to evaluate the requirements for designing indoor THz communication systems at 300GHz. Atmospheric absorption loss, diffraction loss and free space path loss were investigated and modeled. Finally, we discuss several potential application scenarios of THz and the essential technical challenges that will be encountered in the future THz communications. Finally, the article finds that propagating in the THz spectrum is strongly dependent on antenna gain.
Adsorption of Cd(II) and Pb(II) ions from aqueous solutions using mesoporous activated carbon adsorbent: Equilibrium, kinetics and characterisation studies
(Lancaster E-Prints, 2017-02-23) Asuquo, Edidiong D.; Martin, Alastair Douglas; Petrus Nzerem; Siperstein, Flor; Fan, Xiaolei
In this study, cadmium and lead ions removal from aqueous solutions using a commercial activated carbon adsorbent (CGAC) were investigated under batch conditions. The adsorbent was observed to have a coarse surface with crevices, high resistance to attrition, high surface area and pore volume with bimodal pore size distribution which indicates that the material was mesoporous. Sorption kinetics for Cd(II) and Pb(II) ions proceeded through a two-stage kinetic profile-initial quick uptake occurring within 30 min followed by a gradual removal of the two metal ions until 180 min with optimum uptake (qe,exp) of 17.23 mg g1 and 16.84 mg g1 for Cd(II) and Pb(II) ions respectively. Modelling of sorption kinetics indicates that the pseudo first order (PFO) model described the sorption of Pb(II) ion better than Cd(II), while the reverse was observed with respect to the pseudo second order (PSO) model. Intraparticle diffusion modelling showed that intraparticle diffusion may not be the only mechanism that influenced the rate of ions uptake. Isotherm modelling was carried out and the results indicated that the Langmuir and Freundlich models described the uptake of Pb(II) ion better than Cd(II) ion. A comparison of the two models indicated that the Langmuir isotherm is the better isotherm for the description of Cd(II) and Pb(II) ions sorption by the adsorbent. The maximum loading capacity (qmax) obtained from the Langmuir isotherm was 27.3 mg g1 and 20.3 mg g1 for Cd(II) and Pb(II) ions respectively.
Advancement in Magnesium Metal Matrix Composites: A Mini-Review of Production Techniques, Properties, and Applications
(IEEE, 2024-08-15) Peter Pelumi Ikubanni; Adekunle Akanni Adeleke; Samuel O. Oladimeji; Olayinka O. Agboola; Bamidele T. Ogunsemi; Olatunji P. Abolusoro; Peter Onu; Remilekun R. Elewa
The advancement of research in new engineering materials has led to the development of magnesium metal matrix composites (Mg MMCs). This study critically examined the production techniques, properties, and applications of Mg MCs. Powder metallurgy and casting routes were the two classifications of the techniques for producing Mg MMCs. The mechanical, tribological, corrosion, and bio-compatibility properties of the composites and the application of the Mg MMCs were reviewed. Orowan strengthening mechanism, Hall Petch strengthening mechanism, and Taylor strengthening mechanism were the mechanisms responsible for the improvement of the strength of the composite. The study further highlighted the areas for future studies.
Advent of Artificial Intelligence in Automotive Engineering
(IEEE, 2024-02-29) Adeiza Avidime Samuel; Adekunle Akanni Adeleke; Esther Nneka Anosike-Francis; Temitayo Samson Ogedengbe; Peter Pelumi Ikubanni; Favour Oluwasayo Adeyemi; Jamiu Kolawole Odusote; Matthew Onuoha; Usman Shuaib
Artificial intelligence (AI) has long been a topic of interest and with its constant development and growing popularity and functions, it is no surprise that it has made its way into the automotive industry. For ages, people have done research regarding AI in the automotive industry, and with the increasing popularity of this subject, the research only goes deeper. This paper gives an analysis of previous research under different areas which involve AI in automotives, somewhat singling out autonomous vehicles. We also go into the basis of artificial intelligence, as well as highlight a few challenges which face the integration of AI into the automotive industry.
An Assessment of Vehicular Traffic Congestion along Abuja-Nasarawa Road with Emphasis on Karu bridge to A.Y.A. Interchange
(Department of Civil Engineering, Nile University of Nigeria Abuja Nigeria., 2024-04-23) Aluya, L.E; Abubakar Dayyabu; Muoka Anthony
Transportation is integral to societal connectivity and economic growth, with road transportation being a predominant mode globally. Traffic congestion poses a substantial challenge to efficient road transportation, impacting travel times, fuel consumption, and overall productivity. The Abuja-Nasarawa Road, a critical transportation corridor in the Federal Capital Territory, faces persistent congestion issues attributed to factors such as increased vehicle numbers, inadequate infrastructure, and poor traffic management. The escalating traffic congestion along Abuja-Nasarawa Road adversely affects the region's productivity and economic development. This study aims to analyze the traffic congestion along the Abuja Nasarawa Road to improve decision-making regarding road use and transportation system planning. The research design combines qualitative and quantitative methods, utilizing a questionnaire and traffic data collection. The study focused on the A.Y.A Interchange – Karu bridge section of the road, a critical stretch facing congestion issues. The methodology involved traffic data collection, including vehicle counts, traffic volumes, and average speeds. Statistical analysis was conducted using SPSS software. Results indicate varying traffic flow rates during morning and evening peak hours. Karu bridge experienced the highest traffic congestion, with a flow rate of 5433 vehicles per hour in the morning. The qualitative analysis revealed the distribution of road users. The findings also revealed a prevalence of traffic congestion attributed to the concentration of economic activities in the Federal Capital City (FCC), leading to increased commuter influx. This study provides a valuable resource for future urban planning initiatives and highlights the need for comprehensive solutions to solve the region’s complex traffic congestion problems and recommends measures such as maintaining and expanding the road network, introducing alternative transportation like a railway service, and completing alternative routes such as the Apo-Karshi Road.
Analysis of an Experimental Digital Read-outs Slider Crank Mechanism
(IEEE, 2024-08-15) Jamiu Kolawole Odusote; Adekunle Akanni Adeleke; Peter Pelumi Ikubanni; Qudus A. Siyanbola; Oluwasogo L. Ogundipe; Olayinka O. Agboola
Slider-crank mechanism (SCM) was developed with digital read-outs in this study to make the reading of experimental results more accurate. They are connected by joints and force elements for the conversion of reciprocating motion into rotary motion or vice-versa. A digital protractor (accuracy = ±𝟎. 𝟐) and a digital vernier caliper (accuracy = +0.02 mm) were incorporated as the crank and the slider respectively, while a stainless-steel plate was made the connecting link. The deviation of the slider (displacement) values from the corresponding theoretical values at various angles was determined. The simple harmonic ratio of the analogue mechanism is higher than that of the digital mechanism but the deviations of the slider (displacement) values of the digital mechanism from the theoretical values are quite negligible. The deviations of the analogue system from its corresponding theoretical values are far higher. Based on the result obtained, the digital system is more precise and accurate for experimental studies than the analogue system.
ANALYSIS OF PROPERTIES OF REINFORCING STEEL BARS: CASE STUDY OFCOLLAPSED BUILDING IN LAGOS, NIGERIA
(Trans Tech Publications, 2012-02-02) Jamiu Kolawole Odusote; Adekunle Akanni Adeleke
The chemical compositions and the microstructures of reinforcing steel bars obtained from three different collapsed building sites were studied. Optical emission spectrometer was used to carry out the chemical analysis, while the microstructure was examined using an optical microscopy. The carbon contents of the steel bars were found to be higher than BS4449 and ASTM706 standards, but they are in close range with the Nst-65-Mn standard. The manganese contents of the steel bars are lower, while the sulphur and phosphorus contents are quite higher than the BS4449, ASTM706 and Nst-65-Mn standards. The hardness values of the investigated bars are higher than recommended BS4449 standard but lower than Nst-65-Mn standard. Brittle globules of Fe3P and FeS were observed within the structure possibly due to higher contents of deleterious sulphur and phosphorus. The results suggest that the investigated reinforcing bars are brittle and thus contributing significantly to the collapse of the building structures.