Browsing by Author "Adagunodo, Theophilus Aanuoluwa"

Now showing 1 - 6 of 6

Application of frequency selection and geoelectrical sounding methods for mapping of leachate’s pathways in an active dumpsite
(Springer Nature Switzerland, 2023) Adagunodo, Theophilus Aanuoluwa; Ojoawo, Ayobami Ismaila; Anie, Nicholas Oliseloke; Edukugho, Praise Oforitsenere
Contamination of surrounding environments is one of the threats to the proper maintenance of municipal waste sites in developing nations. This study integrates natural electromagnetic (EM) field and geoelectrical sounding methods to assess the leachate’s pathways in the near-surface layers and groundwater system in and around an active dumpsite. Five natural EM traverses were obtained in varying orientations using PQWT-TC 150 model. Fifteen vertical electrical sounding (VES) data points were randomly occupied using SAS 4000 ABEM resistivity meter. The two techniques revealed some intercalations of conductive and resistive media in the study area. The conductive media are composed of mixtures of leachates into clay and groundwater units, thereby creating zones of very low electrical potential differences from the surface to a depth beyond 30 m. A zone of leachate-aquifer’s interphase exists between the third layer and the fourth layer. The directions of the fluid flow are in the S–N and SE–NW trends, which could be linked to the fault towards the northwestern part of the study area. The fluid dynamics, however, justified the reason for the thick conductive materials being mapped at the northwestern and northern parts of the study area.
Causes and Possible Solutions to Road Failure in Nigeria
(Springer Nature Singapore Pte Ltd., 2025) Adagunodo, Theophilus Aanuoluwa; Adeniji, Adetunji Ayokunnu; Okeniyi, Elizabeth Toyin
Cracks, defects and potholes characterize Nigerian roads. It is difficult to travel a long kilometer without coming across defects on the road, which has resulted in severe challenges and fatal accidents in Nigeria. The individual road has its life expectancy. In most cases, some roads fail before the expected service life. Some failures are noticed immediately after construction, some are observed after flood ing, and some failures are revealed as a result of a poor drainage system, while a few others could serve their purpose and life expectancy as a result of adequate mainte nance. In Nigeria, transportation via road is an inexpensive and efficient means of transportation for the masses as other transport systems are too expensive or not mature for commercial services. In most cases, the presence of unrestrained axle loads on most of the road networks in Nigeria has resulted in a reduction in the life expectancy of these roads. This chapter briefly reviews the causes of road failure in Nigeria and possible solutions.
Fluoride Concentrations Within the Shallow Aquifers in Iree, Southwest Nigeria
(Springer Nature Switzerland, 2024) Adagunodo, Theophilus Aanuoluwa; Adeniji, Adetunji Ayokunnu; Ojoawo, Ayobami Ismaila; Ajao, Adekunle Mayowa
Assessing the toxic fluoride concentration in groundwater is critical and vital, since its occurrence in the water has been linked to the natural deposition of parent rocks during weathering. Consumption of fluoride in water can cause serious health problems, such as skeletal fluorosis, dental fluorosis, fertility reduction, urinary tract infection and disorder, nervous system damage and so on. The aim of this study is to determine the fluoride contamination level in the shallow aquifers of a crystalline basement system in Iree community, south-west Nigeria. Fifteen near-surface wells were tested for fluoride constituents and the determination of some physical parameters (such as pH and water temperature). Samples were analyzed by colorimetry in order to determine fluoride concentrations. The normality of the data was tested using the Kolmogorov–Smirnov test, while the fluoride constituents in the water samples were compared to the World Health Organization (WHO) threshold. The obtained fluoride contents varied from 0.75 to 1.5 mg.l−1 , the pH varied from 6.89 to 8.07, and the water temperature varied from 26.8 to 30.5 °C. It was revealed that some near-surface wells exceeded the WHO permissible standard of 1.0 mg. l −1 for fluoride constituents in potable water. Based on these results, it could be concluded that a crucial and periodic assessment of the near-surface wells is recommended to keep track of the fluctuations in the fluoride concentrations within the study area. The outcome of this study will serve as baseline guidance for policy-makers as well as the concerned authorities to know the degree of fluoride constituents in their shallow wells and to proffer possible solutions in mitigating these pollution risks as soon as possible.
Geospatial mapping of radon concentrations and uncertainties in radiological risk assessments using probabilistic modelling: the case of Ibadan
(Springer, 2026) Adagunodo, Theophilus Aanuoluwa; Aremu, Abraham Adewale; Adewoye, Abosede Olufunmi; Oladapo, Olukunle Olaonipekun; Orosun, Muyiwa Michael; Ajibade, Oluwadamilola Ayoola; Muzammil, Khursheed; Zahrani, Yousef
Radon is a primary source of internal radiation exposure, occurring via inhalation and ingestion. This study investigates the distributions and radiological hazards of soil radon and groundwater radon in Ibadan, a major city in Nigeria. Radon concentrations were measured at 41 sites using a RAD7 detection system. The geospatial distribution was mapped using Surfer 10 software, and health risks were assessed via Monte Carlo simulations (MCS). Soil radon concentrations ranged from 1.75 to 47.24 kBq/m3 (mean: 22.30±14.48 kBq/m3 ), while water radon concentrations ranged from 1.12 to 30.48 Bq/L (mean: 14.17±8.80 Bq/L). The average soil radon level falls below the ICRP limit (40 kBq/ m3), but the average water radon exceeded the EPA limit of 11.1 Bq/L. A strong Spearman rank corre lation of 0.96 was observed between the two media. Geospatial analysis identified Class III hotspots (e.g., Pegba and Oranyan) as priority areas for local miti gation. The MCS quantified the probabilistic health burden, revealing a grand excess lifetime cancer risk ranging from 0.007×10⁻(found in the worst-case scenario at Oranyan) with an average mean of 0.605×10⁻3 . Notably, the maximum probable risk in high-exposure hotspots remains below the ICRP reference level of 3.75×10⁻3, suggesting that while the risk is significant, it does not exceed the international threshold for emergency intervention. These findings underscore the necessity of targeted intervention to manage long-term radio logical health implications for the population.
Practice and theoretical analysis of ground penetrating radar in voids detection of urban underground pipe-jacking
(Elsevier Inc., 2025) Adagunodo, Theophilus Aanuoluwa; Hu, Fengming; Yang, Tianchun; Zhu, Debing; Huang, Rui
Pipe-jacking construction technology has become more prevalent with the development of urbanization. At the same time, non-destructive detection of the compactness around the pipe-jacking is a necessary step in the pipe jacking engineering. Therefore, the present study intends to explore the non-destructive detection of pipe-jacking quality by using ground penetrating radar. Ground penetrating radar can also be called GPR for short, and it plays an irreplaceable role in our life through its efficient and nondestructive detection function. In the study, void models for plastic jacking pipes, reinforced concrete jacking pipes, and steel jacking pipes were constructed, and forward simulations of ground penetrating radar were conducted using the two-dimensional finite element method to investigate the parameter influences brought about by seasonal changes and the shape of the voids; furthermore, combined with the sewage jacking pipe project in Xiangtan City, Hunan Province, practical detection and experimental research on reinforced concrete jacking pipes and steel jacking pipes are carried out using ground penetrating radar. The research results indicate that ground penetrating radar is feasible for detecting the density conditions around cement jacking pipes, plastic jacking pipes, and reinforced concrete jacking pipes. However, when detecting the void conditions around steel jacking pipes, strong multiple re flections occur between the radar antenna and the pipe wall, making it impossible to achieve the goal of detecting the density behind the jacking pipe. Therefore, future research is needed to develop new methods and technologies for assessing the construction quality of steel jacking pipes.
Simulation of the Telluric Electrical Field Frequency Selection Method and Its Application in Mineral Water Exploration
(MDPI, Basel, Switzerland, 2025) Adagunodo, Theophilus Aanuoluwa; Yang, Tianchun; Yang, Zhu; Qin, Qin; Zhu, Maoyue
In practical engineering geophysics, anomalous bodies are typically three-dimensional (3-D) structures, making it inaccurate to represent the subsurface geoelectric model using a two-dimensional (2-D) assumption. Furthermore, the underlying mechanism of the telluric electrical field frequency selection method (TEFSM) remains insufficiently understood. To address these limitations, this study presents a 3-D forward modeling algorithm based on the edge-based finite element method to solve the TEFSM forward problem. This paper also investigates the application of TEFSM in mineral water exploration, striving to minimize the influence of strong electromagnetic interference sources such as high voltage power lines. Specifically, the paper presents the forward theory of TEFSM and analyzes the causes of galvanic distortion, particularly static shift. Numerical simulations examine the response characteristics of anomalous bodies and the influence of galvanic distortion. The results indicate that galvanic distortion enhances shallow local anomalies in the modulus of the electric field while masking deeper targets. In contrast, the phase of the electric field effectively reflects deeper anomalous bodies and is minimally affected by galvanic distortion. Future improvements in frequency selectors may enable reliable phase measurements, thereby enhancing data interpretability. Subsequently, the TEFSM was applied to field data collected during mineral water exploration. The field test results confirm the effectiveness of TEFSM and demonstrate that it is a portable, simple, low-cost, and highly efficient method for groundwater detection.