Modeling of 1.0 MW-h Combustible Waste Fuel Steam Thermal Station: A Panacea for Rural/Off-Grid Areas’ Electrification

The problem of energy crisis can be best handled by making a more prudent use of some of those materials viewed as wastes. This study seeks to show how conversion of this waste to fuels can help tackle some of these energy dependent problems. A model of 1.0 MW-h steam thermal station was developed that could utilize wood and palm residues, produced by saw and palm oil mills, as fuels. Ondo and Edo States in southern part of Nigeria were considered as catchalls and data obtained from Mills in these States were used for this evaluation. Estimates were made of the capacity of these residues to evaluate the viability of the study. The Model requires 3.404 tons of waste wood or 2.70 tons of palm kernel residues per hour to meet the turbine steam consumption of 3.37 kg/s. The results revealed that the project would thrive well in the two states when wood residue is considered but could only be effectively in Edo State when firing on palm residue. The viability of the research as a panacea to ameliorate problems of power outages were validated using two software, Boiler efficiency and steam turbine consumption. Keywords: Wastes, Steam,  Electricity, National Grid, Development and Wealt

Factors Affecting the Performance of Labour in Nigerian Construction Sites

The paper identified some factors perceived to be negatively affecting the performance of construction labour and also examined how these factors vary from site to site in the Nigerian construction industry. To achieve this, structured questionnaires were administered on contractors and labour (operatives) on forty construction sites in the study area to sample their opinions. A Likert statistical technique was employed for the analysis in this perspective. The result indicated that unfair wages (RI = 0.89), negative influencing factors (RI = 0.85) and lack of motivation (RI = 0.79) were ranked high by the labour while the contractors ranked lack of training (RI = 0.84), poor communication (RI = 0.79) and inclement weather (RI = 0.71) as being affecting the performance labour in this respect. It was recommended, among other things, that contractors must study the peculiarities of their workers and identify their main motivator

Prefabrication Method of Building Construction in Lagos State, Nigeria: Prospects and Challenges

Though the use of prefabricated elements in construction has been considered as one of the most effective methods, the industry has found difficulties implementing it. The paper provided an overview of the challenges and factors influencing the use of prefabrication in Lagos state. A survey technique was adopted in carrying out this research. This paper studied 100 prefabricated home owners and occupants, and 25 professionals with knowledge and skill in the construction of prefabricated buildings in Lagos state. Two different questionnaires were administered, one to prefab building occupants/clients and the other was administered to professionals in the prefab industry survey based on 5-likert scale. Statistical package for social sciences (SPSS) was used to process and analyze the data obtained from the questionnaires. The use of prefabricated elements in building construction is observed to be an effective and efficient approach to improving construction processes and productivity, ensuring construction quality and reducing time and cost in the construction industry. However, many problems occur with this approach in practice, including initial high cost of construction, unawareness of the prefabricated method of construction, unavailability of prefabrication companies locally, technically and challenges in installation. The study concluded that though there are lots of factors influencing the use of this method of construction, the benefits should be put into effective use. The use of prefabricated elements in building construction in Lagos state is profitable due to the benefit of faster construction time because of the nature of the city and the increasing population of the city. Recommendations were provided to further the use of the prefabricated method of construction more effectively

COMPARATIVE ANALYSIS OF CONCRETE STRENGTH UTILIZING QUARRY-CRUSHED AND LOCALLY SOURCED COARSE AGGREGATES

The use of two types of course aggregates for different works is examined in this study. Typical strength concrete is being made from various aggregates and their impact on various characteristics to the subsequent concrete. Compressive strength is the most vital property of a concrete. In this paper, two forms of coarse aggregates, crushed stone(granite) and unwashed gravel were utilized. Sharp sand is the fine aggregate. Initial laboratory examination was carried out to establish the appropriateness of utilizing the aggregates for construction purpose. Particle size distribution (sieve analysis) and slump test were investigated. Mix ratio (1:2:4) was used for this work and mix structures were analyzed by absolute weight technique. A total of 32 cubes (150×150×150mm) were cast to permit the compressive strength to be observed at 7, 14, 21 and 28 days. Test results revealed that concrete produced from unwashed gravel has a better workability than crushed granite. Higher compressive strength at all period was observed with concrete produced from granite aggregate. Compressive strength patterns were suggested as a result of age at curing

Critical success factors (CSFs) influencing the implementation of industrialized building Systems (IBS) in Nigeria

Conventional method of construction hinders the actualization of triple success project objectives of time, cost and quality delivery of construction projects while IBS method is used for closing these negative effects. Hence, this study aimed at examining critical success factors (CSFs) influencing the implementation of industrialized building systems (IBS) in Nigeria. Adopting a cross-sectional survey design, a close-ended questionnaire was purposively administered online to construction professionals who have distinct knowledge and experience on projects where IBS has been implemented. The data was subjected to descriptive and inferential statistics using IBM SPSS v. 21. The study findings showed that good working relationship, training of skilled workforce, effective communication route and financial capacity are the CSFs furthering the implementation of IBS in a developing country like Nigeria. The implication for practice is for construction stakeholders to develop these competencies to maximally improve the implementation of IBS projects. The study developed a framework that the project stakeholders can implement for an efficient industrialized building system on construction projects

Spark Plasma Sintered High-Entropy Alloys: An Advanced Material for Aerospace Applications

High-entropy alloys (HEAs) are materials of high property profiles with enhanced strength-to-weight ratios and high temperature-stress-fatigue capability as well as strong oxidation resistance strength. HEAs are multi-powder-based materials whose microstructural and mechanical properties rely strongly on stoichiometry combination of powders as well as the consolidation techniques. Spark plasma sintering (SPS) has a notable processing edge in processing HEAs due to its fast heating schedule at relatively lower temperature and short sintering time. Therefore, major challenges such as grain growth, porosity, and cracking normally encountered in conventional consolidation like casting are bypassed to produce HEAs with good densification. SPS parameters such as heating rate, temperature, pressure, and holding time can be utilized as design criteria in software like Minitab during design of experiment (DOE) to select a wide range of values at which the HEAs may be produced as well as to model the output data collected from mechanical characterization. In addition to this, the temperature-stress-fatigue response of developed HEAs can be analyzed using finite element analysis (FEA) to have an in-depth understanding of the detail of inter-atomic interactions that inform the inherent material properties

Appraisal of the drivers of smart city development in South Africa

Abstract: The quest for smart cities and development has been on the increase among infrastructural development stakeholders, including clients, government agencies responsible for the management of infrastructures, construction professionals, sponsors, and financiers of these projects. However, studies around the world have shown that less attention is being paid by these stakeholders to various indices and measures of smart cities. These measures and indices, known as drivers, are smart environment, smart economy, smart people, smart governance, smart mobility, and smart living. Using these drivers and their indicators, a multiple-choice questionnaire was designed in line with existing and relevant literature materials in the subject area. These questionnaires were administered on construction professionals with relevant and adequate knowledge of smart construction. Smart environment was found to be a major driver of a smart city while smart people, smart governance and smart living are also key to the achievement of the goals and objectives of the concept. The developed key smart city drivers are a workable, adaptable and efficient city design mechanism and it will be useful for city planners, statutory agencies as well other stakeholders in the development of smart cities

Assessment of Concrete Durability in Buildings: the Effects of the Quality of Cements Available in Lagos, Nigeria

This paper presents an investigative research that aims to find the effects of the cements available in Lagos, Nigeria on the durability of concrete within the study area. This is in an attempt to stem the rate of building failures in Lagos, Nigeria. The physical, the mechanical and the microstructural properties of the cements have been determined and compared with the standard properties as specified in relevant standards. 150mm cubes have been cast with these cements and all the sources of aggregates within the study area. Laboratory findings have discovered that all the cements investigated have fallen short of the expected strengths specified in standards but the labelled brands had values close to the strength standards but the unlabeled ones have fallen far short of the standard strength. The chemical analysis has complied with standard requirements except for their loss on ignition (LOI) values and the chemical properties have been complemented by the microstructural morphology as determined with the Scanning Electron Microscope (SEM) though the unlabeled brands have tendencies for alkali silica reactivity due to higher levels of alkali present in them. In assessing their performance in concrete, the concrete cube strength has met the expected 20MPa except for the unlabeled brands that have fallen a little short of it. The effects of these cements have been discovered to be very significant on the concrete durability within the study area. It is thereby recommended that the Nigerian regulatory agencies on cements make more efforts in order to ensure that cement manufacturers in Nigeria improve the quality of their cement brands in order to standard strength specification. All cements should be temporarily used as a 32.5 strength class, despising the labelled 42.5, pending when the manufacturers would fully comply their products to standard. Copyright © 2019 Praise Worthy Prize S.r.l. - All rights reserved

Assessment of Effectiveness of Planning Techniques and Tools on Construction Projects in Lagos State, Nigeria

Construction project planning is an essential element in the management and execution of construction projects which involves the definition of work tasks and their interactions, as well as the assessment of required resources and expected activity durations. The study, therefore, examined the awareness of professionals in construction industry of the various types of planning techniques and tools used on construction sites, assessed the effectiveness of planning techniques and tools used on selected construction sites in Lagos State, Nigeria, and identified the factors affecting the choice of planning techniques and tools towards effective and efficient delivery of projects. Questionnaires were administered on selected building professionals (Project Managers, Engineers, Architects), and Contractors and Sub-contractors directly involved in construction work on sites in Lagos State with emphasis placed on planning and the use of planning tools and techniques as major tools for successful project execution. The data obtained were analyzed using the Statistical Package for Social Scientist for Windows (SPSS), and the results were presented by the use of statistical tools such as frequency tables and pie charts. The study shows that there is low awareness on the functional use of construction planning tools and techniques, and recommended that the use of the construction planning tools and techniques should be applied in all building projects and there should be regular adequate training of professionals on the effectiveness and improvement in Information Technology in the construction industry especially in project planning and execution

Histopathological profile of childhood thyroid carcinoma in Ibadan, Southwestern Nigeria

BackgroundThyroid carcinoma is a common endocrine malignancy. It is however rare in childhood and often occurs as a result of radiation exposure or inherited genetic mutations. Most childhood thyroid carcinomas are well differentiated. There are very few epidemiological studies of this disease in Nigeria and our study aimed to determine the frequency in a subset of our population. The study aimed to determine the prevalence and histopathological characteristics of childhood thyroid carcinoma in our environment.MethodsThis was a retrospective review of histopathologically diagnosed thyroid carcinoma in children less than 18 years of age in the Department of Pathology, University College Hospital, Ibadan over a 40-year period. Histopathological diagnosis, age, sex and other relevant clinical information were extracted from the hospital records and surgical pathology records of the department. All cases of patients under18 years old had their slides re-examined and reclassified by two pathologists according to the World Health Organization histopathological classification of thyroid tumours. ResultsThere were 25 cases of thyroid carcinomas seen in children within the study period. Papillary thyroid carcinoma was the most common, accounting for 80% of the cases. Follicular carcinoma accounted for 12%, and medullary and anaplastic carcinoma accounted for 4% each. The mean age at presentation was 13 years. There was a female preponderance with females accounting for 60% of cases. Tumours with distant metastasis made up 20% of the cases.ConclusionChildhood thyroid carcinomas are rare in our environment, with a minority of cases presenting with metastases