INVESTIGATION

This study presented a comprehensive investigation into the failure mechanism and performance modelling of the combustion and emission characteristics of an industrial dualfired steam boiler operating on natural gas and diesel. The study was driven by the reoccurring failure on the third pass, operational inefficiencies and concerns over the environmental performance observed in the boiler system of a bottling company in Nigeria The failure investigation component of the study involved a systematic diagnostic assessment of the third-pass tubes including visual inspection, chemical composition analysis, micro- structural analysis and water chemistry analysis. For performance evaluation, the study employed experimental measurements and computational fluid dynamics (CFD) simulations using ANSYS Fluent to model combustion dynamics, temperature distribution, pollutant formation, and flue gas flow behaviour under various operating loads and fuel combinations. The models were validated against plant data, Furthermore, parametric studies were conducted to optimize key operational boiler control parameters such as air flow, load, variable frequency drive (VFD) and fuel flow rate using Taguchi methodology. Failure investigation results revealed key degradation phenomena due to due to thermal stresses, corrosive water chemistry, tube fouling, scaling, fouling-induced heat transfer impairment. Also, micro-structural examination showed thermal degradation, including decarburization, grain growth, and oxidation, alongside pitting corrosion, indicating high-temperature exposure and scale deposition weakened the metal. The water chemistry analysis revealed elevated levels of total dissolved solids, P-alkalinity, chloride, and silica in the boiler drum water, which contribute to scaling and localized overheating. Major failures was traced to inadequate water treatment and poor combustion control. CFD simulations revealed that scale layers significantly reduces heat transfer, leading to increased failure risk. An optimal water mass flow rate of 0.454kg/s was determined as the effective mass flow rate to attain the desired outlet steam temperature. The study revealed load as the most influential factor, leading to reduced emissions, improved combustion, operational stability and prolonged component life. The findings provide insights into enhancing boiler reliability, thermal efficiency, and environmental compliance.

This paper documents an investigation of the impact of climate change on global and regional water resources in Nigeria using Egor local government area as case study. The aim of this study is to comprehensively examine the impacts of climate change on water demand in Nigeria, and to understand specific challenges that climatic changes cause to our water as well as recommending adaptive strategies for sustainable water resource management. Primary climatic data (Rainfall and Temperature) for Nigeria were collected from the Nigeria Meteorological Station, Lagos between 1960 and 2002. Changes in Lake Chad waters were collected from the National Centre for Remote Sensing (NCRS), Jos. World temperature and water resources data were collected from different sources. The data were analysed using percentages and time series among others. The result shows that the atmospheric concentration of most greenhouse gases (GHGs) is increasing and this has resulted to changing global climate with increasing temperature. The rise in global average temperatures since 1860 now exceeds 0.6℃. The effect of the Green House Gas concentration on global warming as at 2100 is estimated by three scenarios to be 1.5℃ (Low), 2.5℃ (Middle) and 4.5℃ (High). In Nigeria, while rainfall has decreased by 92 mm, temperature increased by 0.8℃ since 1960. This has led to increasing evapotranspiration and water stress resulting in the drying up of rivers and lakes. For example, Lake Chad has reduced in size from 22902 km2 in 1963 to 16884 km2 in 1972 and 304 km2 in 2000. While climate change will make some countries to experience increase in water resources, majority will face serious water stress. Based on projection, by the 2080s, most countries in the Middle East, around the Mediterranean, part of Europe, North and South Africa will face acute water stress while Southern and Eastern Asia, U.S.A. and Alaska will experience reduction in water stress. Some recommendations were made to reverse this ugly situation.

Noise pollution is an increasingly recognized occupational hazard within healthcare environments, where the continuous operation of medical equipment, alarms, and human activity often generates sound levels exceeding recommended limits. This study investigated noise exposure levels and the prevalence of hearing impairment among hospital workers in Benin City, Edo State, Nigeria. A comparative cross-sectional approach was employed in two hospitals, the University of Benin Teaching Hospital (public) and Faith Mediplex Hospital (private). Noise measurements were conducted in selected wards via a calibrated AR824 sound level meter, while structured questionnaires and the Hearing Health Quick Test (HHQT®) were administered to 152 staff members to assess auditory and nonauditory effects. The findings revealed that average noise levels ranged between 63.1 dB and 77.7 dB, exceeding the permissible limit of the National Environmental Standards and Regulations Enforcement Agency (NESREA). The Pediatrics, Emergency, and COPD wards recorded the highest noise intensities. Statistical analysis revealed significant variation across hospital departments (p < 0.05) but no significant difference between public and private hospitals. Among the respondents, 86.2% exhibited signs of potential hearing problems, 21.7% reported hearing difficulty, and 20.4% reported tinnitus. Nonauditory symptoms such as tiredness (52.6%), poor sleep quality (31.6%), and lack of concentration (38.8%) were also prevalent. The study concluded that hospital workers in Benin city are consistently exposed to hazardous noise levels capable of inducing hearing impairment and related health effects. It recommends regular noise monitoring, staff education, and the enforcement of hearing conservation programs within healthcare facilities.

Heat exchangers are fundamental components in thermal engineering, enabling efficient transfer of heat between fluids across various phase states. Their performance largely depends on the thermal characteristics of the working fluid, and improving these characteristics remains a central research focus. Nanofluids—base fluids enhanced with suspended nanoparticles—have emerged as promising candidates due to their potential to significantly improve heat transfer rates. This study investigates the viability of nanofluids as enhanced working fluids for heat exchanger applications, addressing the persistent challenge of increasing heat transfer efficiency in thermal systems. The methodology involved selecting a shell-and-tube heat exchanger and performing detailed mathematical modelling, numerical simulations, and comparative analyses. Simulations were conducted using ANSYS Fluent, supported by theoretical models such as the Maxwell-Garnett relations, Pak and Cho density formulation, and Brinkman viscosity correlations. Mesh generation, boundary condition setup, and performance evaluation were carried out systematically between July and November 2025. Various nanofluid types and volume fractions were iteratively tested to identify the most thermally efficient fluid configuration for the system. The results demonstrate a clear improvement in heat transfer characteristics when nanofluids are employed compared to conventional fluids. Significant enhancements were observed in thermal conductivity, convective heat transfer coefficients, and reduction in hot-air exit temperatures from the heat exchanger. The comparative outcomes confirm the strong potential of nanofluids to boost thermal energy recovery and overall system performance, highlighting their suitability for advanced industrial heat exchanger applications.

This article presents a study which is aimed at identifying the problems and constraints of teaching history in secondary schools in Nigeria using secondary schools in Ukwuani local government area of Delta state . The problem of teaching history is often traced to the low production capacity of the history teacher. This article argues that the dullness of history lessons in class and lack of interest among the students can also be traced to the teacher who is accused of lack of resourcefulness, laziness, intellectual bankruptcy and lack of interest in the subject. This study therefore examines the challenges facing the teaching and learning of History as a subject in senior secondary schools in Ukwuani Local Government Area of Delta state, Simple random sampling technique was adopted to select some History teachers and 100 History students as samples. Questionnaire was designed to collect data while a descriptive statistic was used to answer the three research questions generated in this study. The findings reveal that inconsistent government policies towards History as a subject, the quality of History teachers and the teaching method used in teaching History has adversely affected the teaching and learning of the subject in Ukwuani Government Area secondary schools of Delta State. Based on the findings, it is therefore recommended that the government should make History a compulsory subject for all secondary school students as other core subjects such as Mathematics and English Language, so that they can have adequate knowledge of Nigerian History, learn from the past mistakes of our leaders in order to correct the future. Finally, it is argued that the introduction of non - professional historians as history teachers also constitutes a major problem in teaching history. It is against this background that this study has become necessary in order to make useful suggestions aimed at arresting the constraints. The article summits that the solution to these problems lies in the cooperation of the teachers, students and the government.

This study investigated the persistent challenges associated withlearning Literature in English in Senior Secondary Schools, with a focus on identifying the key factors that hinder students’ interest, comprehension, and overall performance in the subject. Despite the central role of Literature in fostering critical thinking, cultural awareness, and language proficiency, many students continue to demonstrate poor engagement and low achievement. This research therefore examined a range of contributory issues, including students’ attitudes, students’ interest and instructional methods, the availability and suitability of learning materials, and broader environmental and administrative constraints. A descriptive survey research design was adopted, and data were collected from students across selected Senior Secondary Schools. A structured questionnaire was used to obtain reliable insights into the experiences and perceptions of the participants. Data gathered were analyzed using qualitative method to identify dominant themes and patterns. Findings revealed that major obstacles to effective learning of Literature in English include insufficient exposure to literary texts, students’ perception of the subject as difficult or irrelevant, inadequate teacher expertise, and limited use of engaging or interactive teaching strategies. Other notable challenges include overcrowded classrooms, limited time allocated to the subject, and poor access to recommended textbooks. The study also found that socio-cultural factors and a lack of reading culture negatively affect students’ motivation and ability to appreciate literary works. Based on these findings, the study recommended the provision of instructional materials, encourage positive student attitude towards Literature in English, schools should create opportunity such as reading clubs, literary competitions and drama activities to foster motivation and engagement with the subject, enhance the school learning environment and classes should be well structured and conducive for learning. The study concluded that addressing these challenges holistically will significantly enhance the teaching and learning of Literature in English in Senior Secondary Schools.

To understand the popularity of electric vehicles circa 1900, it is also important to understand the development of the personal vehicle and the other options available. At the turn of the 20th century, the horse was still the primary mode of transportation. Steam emerged as a reliable energy source with a proven track record, notably powering factories and locomotives. In the late 1700s, steam also played a role in some of the earliest self-propelled vehicles. However, despite its early adoption in various applications, it wasn't until the 1870s that steam technology began to gain traction in the automotive industry. One significant reason for the delayed adoption of steam technology in cars was its impracticality for personal vehicles. Steam-powered vehicles faced several challenges that hindered their widespread use. For instance, they required considerable startup times, often up to 45 minutes, particularly in cold conditions. Additionally, steam vehicles needed frequent refilling with water, which imposed limitations on their range and practicality for everyday use. These drawbacks underscored the challenges associated with steam-powered cars and contributed to their eventual decline in favor of alternative propulsion methods, such as internal combustion engines and electric motors, which offered greater convenience and efficiency for personal transportation. As electric vehicles came onto the market, so did a new type of vehicle, the gasoline-powered car thanks to improvements to the internal combustion engine in the 1800s. Although gasolinepowered vehicles had potential, they were not without problems. They took a lot of human labor to operate because shifting gears was a difficult operation, and starting them required turning a hand crank, which some drivers found challenging. Gasoline-powered vehicles were also notorious for their noisy engines and nasty exhaust. (TOTAL ENERGIES, 2020) In contrast, electric cars did not suffer from the issues associated with steam or gasoline vehicles. They were quiet, easy to drive, and did not emit the noxious pollutants characteristic of other cars of the time. Consequently, electric cars rapidly gained popularity among urban residents, particularly women. They proved ideal for short journeys within the city, especially considering the poor road conditions outside urban areas, which limited the travel range of all types of vehicles. (Nilesh Wani, 2020)

Traffic flow analysis is a key aspect of transportation and highway engineering that focuses on understanding the interaction between road users (pedestrians, cyclist, and drivers) and infrastructure, with the goal of achieving efficient traffic movement and minimizing congestion. This study was conducted along Airport Road in Benin City, Edo State, Using the moving observer method developed by Wardrop and Charlesworth (1954). This method is a cost-effective approach for analyzing traffic characteristics such as speed, density, space headway, and time headway.The methodology involved on observer traveling along a selected highway section at a suitable speed while recording important parameters. These included the number of vehicles overtaking the observer, the number of vehicles overtaken by the observer, travel time in the direction of the traffic, and travel time against traffic. Data collection was lane-specific, covering both the speed lane and the service lane, and also accounted for vehicle composition. To capture variations in traffic conditions, data was collected under two scenarios: during a period when schools were in session and when they were not.The collected data was analyzed using the Greenshield model, which assumes a linear relationship between speed and density. Results indicated that traffic flow on Airport Road falls under medium traffic volume range. The average time headway ranged from 3.07 to 3.89 seconds, while the average space headway varied between 0.035km and 0.042km. Maximum traffic capacity was found to range between 1064 veh/hr and 1505 veh/hr, with free-flow speeds between 53.01km/hr and 119.27km/hr. Jam density values from 43veh/hr to 102 veh/km. The coefficient of determination (𝑅2) values ranged from 0.365 to 0.844, confirming a strong positive linear relationship between speed and density, consistent with Greenshields model. This study also highlighted the significant impact of vehicular heterogeneity on traffic flow, particularly in the service lane where speeds were lower and density higher. In conclusion, the finding emphasizes that variations in vehicle types and driver’s behaviour significantly influence traffic flow characteristics and highway capacity. A proper understanding of these parameters is essential for effective traffic management, and informed policy-making to enhance mobility and safety on multi-lane highways in Benin City and similar urban environments.

The rapid growth of Artificial Intelligence (AI) has reshaped academic practices in higher education, creating both opportunities and ethical concerns. This study investigated the ethical issues associated with AI use among undergraduate students in Nigerian universities, with a focus on the University of Benin. The research examined how AI tools encourage plagiarism, affect academic integrity, contribute to dependence, promote academic laziness, and influence examination malpractice. A descriptive survey design was employed, and data were collected from seventy (70) undergraduate students across different faculties using a structured questionnaire. The results, analyzed through frequency counts, percentages, means, and standard deviations, revealed that AI tools significantly encourage plagiarism and undermine academic integrity. While students did not show strong overall dependence on AI, findings indicated that selective use promotes moderate laziness and creates new opportunities for exam malpractice. The study concludes that although AI can enhance learning efficiency, its misuse poses serious ethical challenges. It recommends that universities develop policies, awareness programs, and training initiatives to guide students toward responsible AI use, ensuring that technological benefits align with academic integrity and genuine learning

This study examines gully erosion in Uniben, Ovia North East Local Government Area in Benin City, Edo State, Nigeria, using a combination of remote sensing and electrical resistivity approaches. Using the Wenner-Schlumberger array, fourteen profiles were used for 2D Electrical Resistivity Imaging (ERI), and RES2DINV was used to analyze the results. The Inverted 2D Resistivity structure from the study region is used to portray the data in this model in a color-coded manner.The section's vertical scale represents the depths, measured in meters, and its horizontal scale represents the lateral distance. A maximum spread of 200 meters was modelled, and all profiles were examined down to a comparable depth of 39.6 meters. The 2-D resistivity structure
analysis indicates that alluvium, laterite, and clay are present in the first four layers near the surface (12.6 – 31.9 m), and that this presence increases significantly as one descends (31.9 –39.6 m) to suggest that sand (alluvium and Laterite) may be the primary cause of the gully in the area. By integrating geoelectric sections derived from the 2D data, the study delineates the lithostratigraphy of the study area, predominantly identifying sand formations down to a depth of approximately 27 meters.
Moreover, the research includes the application of remote sensing techniques to monitor gully development over time and estimate the extent of gully erosion in the area. It encompasses Digital Elevation Models, as illustrated by heat maps, that employ the Normalized Difference Vegetation Index (NDVI) to evaluate the vulnerability of gully erosion in the studied region. The five zones on the NDVI maps are red, yellow, and green, respectively, denoting places that are very vulnerable to gully erosion, areas that are moderately prone, and areas that are less susceptible. NDVI data were calculated for each season during a four-year period, giving a multi-dimensional picture of the environmental changes in the area.