Arid Zone Journal of Engineering, Technology and Environment (AZOJETE)
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Towards Sustainable Economy: The Role of E-Procurement Implementation in the Delivery of Public Projects in Nigeria
Get PDFContracting firms spend significant resources in an attempt to participate in public project contracts in Nigeria. As such, their working capital and liquidity ratio have always been condensed. The aim of the study was to explore factors influencing the successful implementation of E-procurement for sustainable economy. To attain this goal, the quantitative approach design method was adopted. Forty-five (45) questionnaires were administered to the respondents using random sampling techniques in Lagos, South West Nigeria. Data were collected from the respondent and analyzed using a descriptive statistic in the form of mean item score (MIS), resulting in the various statistical outputs that were used to justify the research questions. The result from the analyses has shown factors such as lack of management support, I.T infrastructure, expertise and business benefit were among the first three that affect e-procurement implementation in the study area The study concludes that integrating technology approaches into the procurement policies relating to public procurement will enhance sustainable procurement and economy through legislative and government support in the area. The study therefore recommends that Construction industry professionals should be computer specialist on how the concern security of submitted tender bid and usually virus attack can be addressed. Lack of upper management support the major hindering should be considered in other to make proper implementation of e-procurement, most importantly, incorporation of educational programs for professionals (workshops, seminars, and conferences)
Implementation of Thyristor Based Control of Separately Excited DC Motor Driven by Single-Phase Semi-Converter
Get PDFThis paper presents the implementation of thyristor-based control for a separately excited DC motor using a single-phase semi-converter. The study focuses on the design, operation, and performance analysis of the system, highlighting its ability to efficiently control the motor's speed and torque. The semi-converter, consisting of thyristors, provides variable DC voltage to the motor by controlling the firing angle, enabling precise regulation of motor parameters. Key aspects, such as circuit design, firing angle control, and power quality considerations, are discussed in detail. Computer aided simulation results demonstrate the effectiveness of the proposed system in achieving smooth and reliable motor control with improved energy efficiency. The findings underline the applicability of thyristor-based control in industrial and automation applications, offering a cost-effective solution for DC motor drives. It is observed that the method of voltage control shows that a rated voltage of 200 V, the rated speed of 1500 RPM and torque of 10.5 N-m cannot be exceeded. The method of field flux control shows that a rated voltage, the rated speed can be exceeded to reach 208 V and 3000 RPM respectively while the rated torque cannot be reached
Development of a Clay Biodigester
Get PDFThe quest for sustainable waste management, reduction of greenhouse gas emission and the increasing demand of energy has led researchers to seek for alternative solution in meeting both demands. Anaerobic digestion technology is used for digesting wastes and producing biogas, which is a source of renewable energy in return. This research work examines the use of clay as an alternative construction material of the anaerobic biodigesters. The biodigesters were carefully designed to ensure airtightness and to attain an anaerobic environment inside the digesters. Clay in its nature tends to retain heat received, abundance in nature and is of low cost. The ability of clay material to retain heat makes it viable for biodigester, as temperature is one of the key parameters in the production of biogas. It employed the prototype and evaluated the rate at which clay biodigester produced biogas as compared to other construction materials. Five (5) different biodigesters containing different sample compositions were used for the experiment. The first biodigester is the control containing 8kg of cow dung mixed with 16kg of water. The second biodigester contains 4kg of cow dung, 4kg of beans chaff mixed with 16kg of water. The third biodigester contains 2kg of cow dung, 2kg of vegetables mixed with 16kg of water. The fourth biodigester contains 3kg of cow dung, 3kg of beans chaff, 3kg of vegetables mixed with 16kg of water. The fifth biodigester contains 4kg of cow dung, 4kg of goat excreta mixed with 16 kg of water. The biodigesters were evaluated under the same anaerobic condition. It was observed that the biodigester with the cow dung and beans chaff combination produced the highest biogas with an average daily production of 0.41litre/day. The biodigester with cow dung, and vegetables gave an average daily production of 0.35litre/day. The biodigester with cow dung and beans chaff gave an average daily production of 0.384litres/day. The biodigester with cow dung and goat excreta gave an average daily production of 0.352litre/day. The biodigester with cow dung only gave an average daily production of 03.6litres/day. All the experiments were carried out on an average daily temperature of 29℃. Each one of the biodigesters have an uptrend line i.e. the higher the retention period, the more the biogas produced. It was also observed that biogas production depends greatly on the temperature of the environment. This is to make biodigesters and green energy easily accessible to the local communities
Evaluation of Municipal Solid Wastes Characteristics Towards Electricity Generation in Maiduguri Metropolis
Get PDFThis paper evaluates the characteristics of municipal solid waste (MSW) in Maiduguri metropolis for its potential use in electricity generation. Three key areas within Maiduguri were selected for the study: Area A (Northern Nigeria Flour Mills), Area B (Monday Market/Gwange area), and Area C (University of Maiduguri dumpsite). Additionally, three seasonal periods were considered - (1) rainy season, (2) cold/harmattan season, and (3) hot season. Refuse dumps in these areas were visited during each season to collect and analyze the MSW. The characteristics of the MSW were evaluated through physical analysis, which involved sifting through the waste and separating it into its major components. Further analysis included proximate and ultimate analyses conducted according to ASTM standards to determine the properties of the waste. The study revealed that the composition of refuse produced by communities in Maiduguri varies due to seasonal and behavioural changes. Wood, plastics, and grass were identified as the major physical constituents of the waste, with their proportions influenced by seasonal variations. The calorific values of MSW samples varied across the study areas, reflecting differences in population density and commercial activities. The highest calorific values were recorded in Area B during the rainy and cold seasons, with values of 19.81 MJ/kg and 15.055 MJ/kg, respectively. At the University of Maiduguri dumpsite (Area C), the calorific values of MSW samples were 7500 MJ/kg, 8420 MJ/kg, and 4500 MJ/kg for the rainy, cold, and hot seasons, respectively, resulting in an average of 6800 MJ/kg. This average is below the minimum calorific value of 7000 MJ/kg required for setting up an incineration plant with energy recovery. To enhance the energy potential of the MSW from the University of Maiduguri, supplementary fuels such as bagasse would need to be added to boost its calorific value and make it suitable for electricity generation. This study highlights the potential for MSW utilization in Maiduguri and identifies areas for improvement to optimize its energy recovery capabilities
Production of Bio-Gel from Waste of Cassava and Maize
Get PDFBio-ethanol was produced using starch extracted from cassava peel and cellulose from Corn cobs using acid hydrolysis and yeast for fermentation while Bio-gel fuel was produced using a composition of bioethanol and gel from water and Carboxymethyl Cellulose (CMC) in ratio 80%, 20% by volume respectively. The average yield of bioethanol is 757.33ml for cassava peel and 595.56 for corn cobs from 3.55L and 3.35L of filtrates respectively. The properties of bio-ethanol produced from the two samples compared favorably with the commercial ethanol. The bio-gel fuel which is an alternative source for cooking can also support outdoor burning. The formulation is made from 100% recycle of agricultural wastes making it very economical. The research work will have considerable impacts on the vision of bio-economy launched by many African countries, which is to be achieved through the creation and growth of novel industries that generate and develop bio-based services and products. It will also support the local content initiative of Nigeria government. The success of the study has a great impact on the environment being a waste conversion study
Barriers to Adoption of Construction 4.0 for Circular Economy: A Qualitative Approach
No full textDespite global advances in Construction 4.0 technologies for supporting circular economy (CE) goals, adoption remains limited in developing countries particularly Nigeria where contextual barriers remain poorly understood. Digital tools such as Building Information Modelling (BIM) and Internet of Things (IoT), drive sustainability through resource efficiency, waste minimization, and a closed-loop material flow. However, the extent to which these technologies are adopted in developing countries like Nigeria remains under-researched. This study investigates the specific challenges impeding the adoption of Construction 4.0 technologies in advancing CE practices within the Nigerian construction industry. While global literature highlights barriers such as cost, regulatory gaps, and resistance to change, this research uncovers localized obstacles including infrastructural deficiencies, poor internet reliability, dominance of the informal construction sector, and limited technical training opportunities. Using a qualitative research design, semi-structured interviews were conducted with industry professionals in Lagos State, Nigeria who were selected through purposive and snowball sampling to ensure relevance insights. Thematic analysis revealed that while most of the barriers identified mirror those already established in global literature such as high implementation costs, general lack of awareness, regulatory inadequacies, lack of standardization, skill shortages and implementation capacity, the study also uncovers additional, context-specific challenges that deepen understanding of these barriers in Nigeria’s setting. These include chronic infrastructural deficiencies such as unreliable internet and power supply, the dominance of an informal construction sector that resists standardization and technological uptake, and deep-seated cultural resistance to digital transformation. Furthermore, the study finds that even where awareness of technologies like BIM exists, practical adoption remains minimal due to the absence of policy support, technical training frameworks, and adequate incentives. For instance, several participants noted that Construction 4.0 tools are seen as “premium” and often incompatible with the cost and workflow structures of small- and medium-sized firms, especially those operating informally. This paper contributes to the literature by situating global adoption challenges within a localized Nigerian context, highlighting how familiar barriers are amplified by the institutional dynamics specific to developing countries, particularly Nigeria. The findings offer insights for policymakers, construction firms, and educators seeking to promote CE through construction 4.0. The findings also have practical implications for improving policy, workforce training, and infrastructure investment strategies tailored to Nigeria’s construction sector. By revealing how global challenges manifest in context-specific ways, the study supports the development of targeted interventions that bridge the gap between innovation and local feasibility
Transesterification of Waste Frying Oil Using Alkaline Activated Waste Marble Catalyst: Effects of Process Parameters, Modeling, and Optimization
Get PDFThrough calcination at 600oC for four hours, a novel alkaline activated waste marble heterogeneous catalyst was produced and successfully used for biodiesel synthesis from waste frying oil. To determine the catalyst's appropriateness for the process, Scanning Electron Micrograph (SEM), X-ray Diffraction (XRD), Brunauer-Emmett-Teller (BET) and Fourier Transform Infrared Spectroscopy (FT-IR) were used. Similarly, to determine the waste frying oil's suitability for the transesterification process, FT-IR and GC-MS (Gas Chromatography Mass Spectrometer) were applied in its characterization. The variables (time, temperature, catalyst dosage, methanol/mol ratio and agitation speed) were considered during the transesterification process, and an increase in the process parameters significantly affected the yield. In addition, Response surface methodology (RSM) was applied to optimize the best conditions; the second-order polynomial model is displayed in the Analysis of Variance (ANOVA) with an R2 value of 0.9564, Adj R2 (0.9216), and Pred R2 (0.8257), indicating the acceptability of the model. The optimal yield of biodiesel (86.25%) was obtained at a catalyst concentration of 2.52wt. %, methanol/molar ratio of 6.14mol/mol, time of 1.10 hours, temperature of 59.8oC and agitation speed of 325.2rpm. Interestingly, the WFO biodiesel produced complied with ASTM D6751 requirements
Using Cloud-Based Application for Assessment of Extreme Threat of Climate Impact on Water Resources: A Case of Vaal River Catchment, South Africa
Get PDFClimate change impact on water resources is becoming a global challenge with persistent escalation of threating weather and changes in precipitation patterns. The study evaluates the extreme impacts of climate change in Vaal River in South Africa. The channel of Vaal River is an area with a critical water resource which supports agricultural, industrial and domestic activities. A three-decade dataset (1993-2023) of precipitation, temperature, streamflow, combined with surface water changes was engaged to examine climate impact on Vaal River water resources. Modified Normalized Difference Water Index (MNDWI) derived from Landsat-5 (1994–2012) and Landsat-8 (2013-2023) imagery on the Google Earth Platform (GEE) was also used to examine the seasonal water stress and availability. The results revealed increasing temperatures and irregular precipitation which are indications of climate altering condition resulting to decreased surface water coverage especially during dry seasons. MNDWI result records a fluctuating value indicating variations in both seasons. Further result revealed weak correlation between precipitation and streamflow, driven by anthropogenic regulations and land use, The MNDWI wet season's linear trendline showed a positive slope of 0.0046 and R² value of 0.26 suggesting water availability over time. Similarly, polynomial trendline for the MNDWI dry season equally shows a moderate coefficient R² value 0.38 Adaptive strategies, including Integrated Water Resource Management (IWRM) and advanced monitoring systems that will include stakeholders, planners and policy makers at all levels are recommended to mitigate these impacts. More effort should be channeled towards sustainable solutions such as tree planting, tree box filter and afforestation practices to reduce the effect of climate change on water resources
Biodiesel Production from the Blend of Sunflower, Avocado Seeds and Waste Soybeans
Get PDFThe climatic, environmental, and health concerns of fossil fuels have spurred the development of biodiesel as an alternative fuel. Biodiesel production has transitioned from single lipid-based feedstock to hybrid lipid-based feedstock owing to the challenges related to the former. Unlike previous studies that focused on singular and binary feedstock, this study uniquely employed ternary oil blends to synthesize biodiesel via alkaline transesterification and measured selected oil and biodiesel fuel properties using standard test methods. The studied hybrid oils were extracted (using the Soxhlet method) from ternary feedstock (72%, 20%, and 8% by weight of soybeans, avocado seeds, and sunflower seeds) and characterized for the physicochemical properties: viscosity, moisture content, volatile content, ash content, higher heating value, free fatty acids, and density. The measured biodiesel fuel properties were kinematic viscosity, density, flash point, pour point, and lower heating value. Results revealed that the hybrid oil properties were observed to be within the range of values for individual feedstock that made up the oil. The biodiesel produced has a yield of 81% and exhibited a kinematic viscosity of 3.75 mm2/s, density of 893 kg/m3, flash point of 122 °C, pour point of -11°C, and lower heating value of 34.96 MJ/kg. These fuel properties were observed to conform to biodiesel standards. Relatively low kinematic viscosity and pour point, and high lower heating value and flash point of the studied biodiesel were recorded due to the synergetic effect of oil hybridization. Therefore, selective mixing of different oils from existing feedstock for biodiesel production is recommended as this would further improve biodiesel fuel properties and consequently, enhance the performance, combustion, and emissions of biodiesel-fueled engines. Hybrid oil deployment will assist in addressing existing problems related to the use of single-feedstock based oil, with the ultimate view of promoting carbon neutrality in agreement with the Sustainable Development Goals
Review of Smart Grid Technology and the Nigerian Electricity Act: Addressing Power Sector Challenges Through Policy and Innovation
Get PDFEnergy policy plays a crucial role in shaping the energy landscape of any region. The reform of the Nigerian Electricity Act in 2023 marked a significant milestone for the Nigerian electricity market. It established a legal foundation aimed at addressing the nation’s perennial energy crisis by enabling the adoption of modern sustainable technologies and initiatives into the Nigerian power industry. Poor policy implementation, inadequate generation, and unplanned downtime due to faults on the defunct transmission and distribution networks have stifled the growth of power delivery in Nigeria, emphasizing the need for more intelligent and sustainable power infrastructure. This paper presents a comprehensive review of the challenges in Nigeria’s power sector and explores how emerging technologies can provide effective solution at every node of the power chain. It draws insights from global case studies and outlines a strategic roadmap and timeline for planning and implementing smart grid and sustainable initiatives in Nigeria. Additionally, it highlights critical considerations necessary to promoting long-term sustainability within Nigeria’s power industry