Department of Physics.

Permanent URI for this communityhttp://itsupport.cu.edu.ng:4000/handle/123456789/28754

Welcome to the Department of Physics.

Browse

Now showing 1 - 20 of 36

Path Loss Prediction on Earth-Space Link Using Statistical and Time Series Approach at Ka-Band in Abuja, North Central Nigeria
(ICSAEES-2024, Lagos, Nigeria, 2024) Arijaje, T. E.; Omotosho, T. V.; Aizebeokhai, A. P.
Predictive path loss modelling is essential in designing wireless communication systems. However, the empirical methods of path loss prediction are inaccurate as the empirical models cannot be implemented outside the area or region where they are developed. This study focuses on improving the prediction of path loss using statistical approaches such as multiple linear regression (MLR) and time series models using eight (2014 – 2021) data retrieved from the global precipitation measuring mission (GPM) at Ka-band. The step-wise selected method was adopted for the multiple linear regression (MLR). In the exponential smoothing method, weighting is carried out exponentially, decreasing in the direction of the older values. The MLR analysis revealed that the MLR model performs well, with an accuracy of 99.52%. The R2 value of 99.52% indicated a strong correlation between the estimated and predicted path loss in the model. PL = 18.706 0.98459 − Pr +1.60027Pt + 0.99808Gr The P-value of the regression model is 0.000, indicating that the model estimated by the MLR procedure is statistically significant at a level of 0.05. Also, the results showed that the transmitted antenna gain is the most contributed predictor in the path loss with a value of 1.60027 dB. Likewise, the results from the exponential smoothing models revealed that the single exponential smoothing (SES) model performs better than the double exponential smoothing model with a mean absolute percentage error (MAPE) of 14.47%, indicating that the model's performance is good because the MAPE value falls within 10 – 20%. The mean absolute deviation (MAD), mean square deviation (MSD), and smoothing constant are 0.3215, 0.2313, and 0.9685, respectively. Striking a balance, the application of MLR and the SES models will improve wireless communication systems in Abuja, the North Central region of Nigeria, at Ka-band. Therefore, engineers and policymakers in the Nigerian telecommunication industry should assess the impacts of path loss within the study locations towards sustainable telecommunications and infrastructure (SDG goal 9) for planning and setting radiowave propagation technologies in the study locations and Nigeria at large.
Seasonal Variation of Total Attenuation between Airborne Platform and Earth Station in South-West Region, Nigeria
(7th International Conference on Science and Sustainable Development and Workshop, 2024) Arijaje, T. E.; Omotosho, T. V.; Aizebeokhai, A. P.; Akinwumi S. A.
The seasonal variation of total attenuation in the southwest region of Nigeria has been computed using eight (8) years dataset at Ku- and Ka-band of the transmitted power of the radar, transmitted antenna gain and the received antenna gain of the satellite retrieved from the archived of the GPM. The results obtained fluctuates between the seasons at Ku- and Ka-band. From the results obtained at Ku-and Ka-band, the results from analysis showed that the peak total attenuation was recorded between the early (MAM) and late wet (JJA) season when the intensity of rainfall is maximum in the South-West region. As a result, the effect on the airborne-earth station link will be severe which may further lead to signal outage. However, the state where the highest total attenuation was consistent is Lagos state. These seasons and Lagos state must be taking into consideration by engineers and radiowave propagation group when planning and sitting radiowave propagation in the study area.
INVESTIGATION OF LEACHATE INFILTRATION ON GROUNDWATER USING GEO RESISTIVITY AND NATURAL ELECTRIC FIELD METHOD AROUND OJOOU-OLAYANJU’S DUMPSITE, ADA, SOUTHWESTERN NIGERIA
(Nigerian Journal of Technology (NIJOTECH) Vol. 43, No. 1,, 2024) Adeniji, A. A.; Ajani, O. O.; Adagunodo. T. A.; Kolawole, T.
The investigation of groundwater within the dumpsite environment is highly important in geophysical study. This is because the extent of interaction between the aquiferous medium and the contaminated zone could pose a serious threat to the end users especially humans when consumed. This research aimed at investigating leachate infiltration and its potential influence on groundwater at Ojoou Olayanju's Dumpsite using combining geo-resistivity and natural electric field (NEF) methods. In this study, five dipole-dipole and five NEF measurements were obtained using the Omega resistivity meters and PQWT-150 equipment respectively. The dipole-dipole method was deployed to obtain a 2D near-surface pseudo-section, and the NEF method was used to obtain the frequency curve and profile maps of electric potential difference. The dipole dipole results revealed the lateral variation in the resistivity along the traverses, suggesting that the materials within this near-surface are heterogeneous, and the closely spaced contours' varying gradients indicate fracture, which would facilitate potential leachate filtration. The NEF results revealed curves, and a subsurface image with respect to depth and profile distance. The points of convergence signals on the frequency model correspond to a medium with low resistivity on the profile map. The conductive medium is seen as being saturated with leachate, which suggests that very large portion of the study area around the dumpsite has been contaminated by leachate. Conclusively, it was revealed that leachate filtration is evidence especially at the topsoil and due to the presence of fractured zones, the groundwater quality is at risk of contamination by continuous filtration of leachate.
Hydrogeophysical Investigations for Groundwater Resources Sustainability in Parts of the Eastern Dahomey Basin, Nigeria
(ImprintCRC Press, 2024) Oyeyemi, Kehinde D.; Aizebeokhai, Ahzegbobor P.; Okon, Emmanuel E.; Oladunjoye, Michael A.
Geophysical surveys including geoelectrical resistivity and time-domain induced polarization (IP) techniques have been conducted in Ota in Eastern Dahomey Basin. Thirty vertical electrical sounding (VES) profilings were conducted using a Schlumberger array with an AB/2 range of 180–240 m. Two profiles of 2D electrical resistivity imaging and IP surveys were conducted with Wenner array configuration. The delineated geoelectric layers are topsoil (lateritic clay), clayey sand, sandy clay, sand, and shale or clay units. Two aquifers were delineated in the area with the upper aquifer being a fine-to-medium sand and the lower aquifer of a poorly medium-to-coarse sand unit. The aquifer resistivity ranges are 347.4–411.4 https://www.w3.org/1998/Math/MathML" display="inline"> Ω m https://www.w3.org/1999/xlink" xlink:href="https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west 1.amazonaws.com/9781003454908/c35032d3-f666-459f-b1ca a1b405d5a7b1/content/C025_equ_0001.tif"/> and 104.5–143.3 https://www.w3.org/1998/Math/MathML" display="inline"> Ω m https://www.w3.org/1999/xlink" xlink:href="https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west 1.amazonaws.com/9781003454908/c35032d3-f666-459f-b1ca a1b405d5a7b1/content/C025_equ_0001.tif"/> for the upper and lower aquifer, respectively. The hydraulic parameters of both aquifers were estimated using established mathematical relations. The upper aquifer has porosity, hydraulic conductivity, and transmissivity ranges of 19.1% 21.8%, 10.8 × 10−2 (m/s)–17.0 × 10−2 (m/s), and 1.49–2.4 (m2/s), while the lower aquifer unit has porosity, hydraulic conductivity, and transmissivity values of 43%–55%, 248 × 10−2–782 × 10−2 (m/s), and 34.72–101.66 (m2/s). High hydraulic parameters in the two aquifers are important for sustainable groundwater development, ensuring efficient use and protection of this vital resource. Their significance extends to promoting regional economic growth by supporting agriculture, industries, and tourism. Mapping faults in the area highlights the need for hydrogeological modeling to discern their impact on aquifer parameters, vital for precise resource management, and predicting potential effects on availability and quality.
NS23C-03 Geophysical Imaging for Assessing Restored Wetlands' Soil Properties, Infiltration Rates, and Potential Surface Groundwater Interaction
(AGU24, 2024) Aizebeokhai, Ahzegbobor P.; LaPoint, Hannah N.; Doro, Kennedy O.
Efforts to reduce nutrient loading into Lake Erie include restoring old farm fields within Northwestern Ohio to wetlands. With a history of intensive farming, these fields are characterized by legacy nutrients, altered soil structure and drainage tiles. Inadequate knowledge of soil properties distribution, drainage tile locations and potential surface groundwater interaction at the sites limits restoration projects' effectiveness. This study combined a rapid geophysical site characterization framework with in-situ soil cores and hydraulic tests to assess variations in soil properties and hydraulic processes. We used a 250MHz PulseEkko ground penetrating radar (GPR) system and an EM38-MK2 conductivity meter to acquire GPR and electromagnetic imaging (EMI) measurements at selected wetlands with the equipment towed behind a utility terrain vehicle to allow extensive spatial coverage. Electrical resistivity (ER) data were acquired along transects using a Supersting R8 resistivity meter with an 84-electrode switch box. The ER measurement was done using a dipole-dipole array with 1m electrode spacing. Co-located soil cores were collected along the transects for laboratory soil moisture content, organic matter and texture measurements. In contrast, in-situ measurement of soil-saturated hydraulic conductivity was done using a SATURO infiltrometer. The apparent electrical conductivity (ECa) and ER distribution show comparable subsurface structures and parameter zones, and ECa correlates strongly with soil moisture, organic matter and silt contents (R2 >0.7; p-value <0.002). The ECa also notably correlates with the soil saturated hydraulic conductivity (R2 = 0.85), indicating the possibility of using EMI to rapidly characterize potential water retention zones (low Ksat) in restored wetlands. The spatial distribution of geophysical parameters depends linearly on soil properties distribution. This geophysical-soil-property relation, developed through a rapid site characterization framework, allows for improved soil sampling and monitoring plans. This study shows the effective application of EMI, GPR, and ER for pre- and post restoration characterization of old farm fields with legacy nutrients and drainage tiles that contribute to nutrient loading into Lake Erie.
Application of VLF-EM response and geoelectrical sounding in groundwater investigation around an active dumpsite
(Application of VLF-EM response and geoelectrical sounding in groundwater investigation around an active dumpsite, 2024) Adeniji, A. A.; Ajani, O. O.; Adagunodo, T. A.
An integrated geophysical method combining very low frequency electromagnetic (VLF-EM) and vertical electrical sounding (VES) methods were carried out around Adaland, Southwestern Nigeria, located within latitude 70 54' 0" and longitude 40 43' 0", with a view to investigate the possible impact of dumpsite on groundwater.This is the major study in the environment to offer extensive evidence regarding the suitability of obtaining quality groundwater. In this research, eight VLF-EM and twelve VES data sets were generated, which were then used to estimate the linear structure, bedrock formation, subsurface geological characteristics, and identification of leachate pathways. The VLF-EM data were analyzed by employing Karous_Hjelt and Microsoft Excel, while the VES data were investigated using the WinRESIST software. TheVLF-EM results confirmed the presence of conductive zones, which might be due to fracture, fault and contact zones or weathered basements. The lithological units acquired from the electrical resistivity results revealed four geoelectrical layers such as topsoil, weathered-based, fractured basement and fresh basement. However, the identified weathered layers and fractured basements from the geoelectrical sections and the corresponding Karous and Hjelt (K-H) pseudo sectionresults around the dumpsite, constitute the main passages for the possible impact of the open dumpsite on groundwater quality, since leachates from the dumpsite could slowly percolate downwards from the topsoil to the water table. Therefore, the impact of the dumpsite on the groundwater is caused by the inadequate clay materials, near-surface features such as fractures/faults, and lateral in-homogeneity. Thus, integrating both methods has been recommended in site characterization for accessing quality groundwater around a dumpsite environment.
Geophysical Investigation of the Subsurface Structural Competency Around College of Computing and Communication Studies, Bowen University, Iwo, Osun State, South West Nigeria
(INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN APPLIED SCIENCE (IJRIAS), 2024) Kolawole, T.; Ajani. O. O.; Adeniji, A. A.; Aweda, F. O.; Adagunodo, T. A.
Mapping of the subsurface structures within the environment is highly essential in engineering site characterization. The subsurface structure around the college of computing and communication studies, Bowen University Nigeria was studied using the very low frequency electromagnetic (VLF-EM) and the geo-electrical resistivity method. This was aimed with a view to investigate the weak and competent geological zones. In this study, five traverses were generated for both the VLF-EM and geoelectrical resistivity method, using the VLF-EM 16 equipment and OHMMEGA-Terrameter respectively. The results of the VLF-EM revealed the presence of positive and negative anomalies responses. The positive anomalies indicate the weak zones, which may be caused by geological structures such as faults/fractures, and contacts between rocks and the negative anomalies indicate the competent zones, which may be due to hard rock/laterite. The geo-electrical resistivity results revealed the vertical and lateral inverted resistivity values of the subsurface structure. The result revealed four layers such as top soil, weathered layer, fractured and fresh basement. From both the interpreted results, the weak/fractured zones mapped in the basement are points of interest in this research. The results of the investigation revealed that the probable cause(s) of the structural failures within the study area are evidence of geological features mapped as fracture and clayey formation that is present in the study area. Therefore, in order to evade future structural problems and minimize capitals used in restoring distressed structures in the University, a geophysicist services should be engaged for pre-foundation studies, which will act as a guide before and during construction.
Assessment of sustainable geothermal potential in Patigi region, North-Central Nigeria
(ICSAEES-2024, Lagos, Nigeria, 2024) Salaudeen, S. A.; Adagunodo, T. A.; Sunmonu , L. A.; Suleman, K. O.; Ayanbisi, O. W.; Oladapo, O. F.
Global Transmission Margins Determination and Cloud Attenuation Models at Satellite Bands
(Scientific Research, New Technologies and Applications Vol. 7, 2024) Adewusi, O. M.; Ometan, O. O.; Akinwumi, S. A.; Omotosho, T. V.; Akinyemi, M. I.
Considering the fact that various dimensions of disturbances occur in the atmospheric layers randomly, which often have consequential footprints on the troposphere where mankind naturally lives, there is an obvious need for periodic determination of effective transmission margins consistently for most geographic locations on Earth. The need for the achievement of an effective wireless transmission margin and larger bandwidth at a relatively lower cost precipitates the importance of hydrometeor models’ roles in satellite transmissions. Also, the almost perpetual existence of clouds in tropical climates makes cloud models all the more fundamental. Details of four years of station spectrum analyzer data, five years of climatological data and fifty – eight years of radiosonde data used in this research at tropical test station - Ota, southwest Nigeria - were earlier published. At the station, total cloud attenuation data were measured and logged every minute using the spectrum analyzer. The large data was used to deduce the station cloud attenuation cumulative distribution, which was used to derive the station's new cloud attenuation algorithm. This cumulative distribution was compared with the station cloud attenuation cumulative distribution of each of the other existing cloud models. The radiosonde data was used to derive each existing cloud model’s predicted cloud attenuation cumulative distribution respectively for the tropical station. These sets of distributions were used to deduce the station's new cloud attenuation algorithm’s parameters through a written and published simulation program, which defined the cloud attenuation model for the station. Thus, the generation of any new station cloud attenuation model only fundamentally requires the station’s radiosonde data. The integrity of the radiosonde data renders cloud cover data and all others for a station only for graphical comparisons and corroboration. Thus, the new cloud attenuation algorithm can be used to develop the cloud attenuation model for any geographic location by using the methodology reviewed above and whose details were earlier published. Subsequently, the collected spectrum analyzer data, climatological data and acquired radiosonde data were used to compute projected attenuation values for each cloud attenuation model at propagation signal frequencies between 12 GHz to 50 GHz. The predicted values were extracted and analysed statistically. Spectrally, the station's new cloud attenuation model’s cumulative distribution proportionally averaged the other model’s characteristic cumulative distributions as shown by the graphical figures. The results show that convergence of the range of predicted attenuation values by each of the cloud models increases directly with frequency. Hence, global hydrometeor transmission margins for any set of locations can be determined through the explained method, at an effective frequency.
Theoretical Study of Quantum Efficiency and Spectral Response of Solar Cells
(7th International Conference on Science and Sustainable Development and Workshop, 2024) James, U. E.; Dim, C. C.; Akinyemi, M. L.; Ogunrinola, I. E.
A theoretical study of Quantum Efficiency (QE) and Spectral Response (SR) of solar cells was done in order to suggest ways in which related parameters could be optimized for maximum conversion efficiency of solar cells. Secondary data for the base, emitter and total parameters of QE and SR were obtained. MATLAB was employed in plotting and analysing these data across different diffusion lengths. From the results obtained, it was observed that when the value of the Emitter Diffusion Length (EDL) was varied from 0.3µm to 0.5µm, the emitter and total values of QE increased by about 700% at wavelength 300nm – 400nm. In the case of SR, it was observed that when there was an increase in the Base Diffusion Length (BDL) from 20µm to 50µm, there was an increase of about 26% at wavelength 800nm – 900nm. A rise in the diffusion length was seen to increase both the QE and SR of the cell. Thus, it can be suggested that an increase in the emitter and base diffusion length of a solar cell leads to a decrease in the recombination charges in the cell, giving more time for the charge carriers to exit the cell.
Machine Learning Projection in Performance Evaluation of Cloud Attenuation Prediction Models for Satellite Transmission Quality Improvement
(2024) Adewusi, M. O.; Ometan, O. O.; Akinwumi, O. A.; Omotosho, V. T.; Akinyemi, M. L.
Artificial satellite applications to information transmission remain of great importance now and in the foreseeable future. While machine learning is breaking research achievement records for good, the increase of political influence on scientific potentials needs to be managed cohesively by all for sustainability. The reliability of social and business interactions on communication infrastructure determines the technological advancement of every nation – developed or still underdeveloped. In the disclaimer notices of most financial institutions' transaction forms and mandatory customer business agreements, they declared that they are not liable for communication channel malfunction that may lead to transaction interruption, transmission blackout, and subsequent delay in their services. These prescribe effective hydrometeors attenuation margins determination periodically, from more accurate models – such as machine trained ones, to guarantee an increase in reliability of signal transmissions for every geographic location globally. Earlier research works established that required increases in transmission frequency for better efficiency are directly proportional to consequent hydrometeor attenuation on the signal, and that satellite communication unavailability in most tropical regions is above the allowed 1% outage percentage, significantly due to cloud attenuation contribution at satellite bands - which have been increasing consistently. The existence of clouds in tropical climates is almost perpetual, making cloud models all the more fundamental in tropical regions – which include Africa and not less than half of the rest of the world. The published new tropical cloud attenuation algorithm and its resulting new tropical cloud attenuation model (NTM) - derived from it, are hereby further analysed with respect to a wider frequency range. In the primary research of this work, data were collected from a spectrum analyzer, weather-link, and radiosonde equipment. The data were used to calculate values of cloud attenuation by each major existing cloud model in the signal propagation range of 12 to 50 GHz. The predicted cloud attenuation values were spectrally processed and analysed, resulting in the observation that the NTM’s predictions generally average the characteristics prediction values of existing models as shown by presented graphical outputs, though its differences in values relative to each of the other models are substantial in most cases, as either an increase or a reduction. Also, the predicted attenuation values by each of the cloud models converge increasingly direction-wise with frequency. The stated periodicity requirement above in these regards needs a machine learning approach to at least increase the periodicity of the result’s integrity and reliability by several tens of years, for every geographic location globally.
Construction of a Biogas Digester Using Gas and Temperature Sensor
(International Journal of Environmental Engineering and Development Vol 2, 2024) AKINWUMI, Sayo A.; OSCAR, Blessing N.; MASTORAKIS, Nikos E.; AYANBISI, Oluwasegun W.; OLADAPO, Olutade F.; OGUNWALE, Emmanuel I.
The construction of a biogas digester is the ma in emphasis of this project. Biogas is a mixture of gases created during the anaerobic decomposition of organic material, including food waste, animal waste, sewage, and waste from farms and plants. One of the major causes is environmental degradation, which has emerged to be the greatest threat to the health of the environment and the economy of the underdeveloped areas. But with the discovery and application of biogas which is a gaseous fuel obtained from biomass by the process of anaerobic digestion, most problems are resolved. The project’s aim is to create a biogas digester that leverages animal manure to generate biogas for usage at Covenant University. The digester selected for construction is a barrel drum digester for the production of biogas using cow dung. The cow dung was tested for a total of 14 days, during which the days of gas production and digestion were observed, and the biogas was then tested with the gas and temperature sensor and was confirmed to detect gas and temperature.
Eco-friendly Weather Monitoring Device using Arduino Mega and Sensor Integration
(ICSAEES-2024, Lagos, Nigeria, 2024) AKINWUMI, Sayo A.; Okey-Amadi, O.; Ayara, W. A.; Akinwumi, O. A.
The project involved the construction of a hardware setup, utilizing the Arduino Mega as the central control unit. The BME280 sensor was employed to monitor temperature, humidity, and atmospheric pressure, providing comprehensive weather data. The SGP30 sensor was utilized for analyzing air quality, detecting various pollutants such as volatile organic compounds (VOCs) and carbon dioxide (CO2) levels. The MQ135 gas sensor enabled the detection of harmful gases, including ammonia, nitrogen dioxide and benzene. The integration of a 16x4 LCD display allowed for real-time visualization of the collected weather data, providing users with immediate insights. Tactile switches, along with 10k ohm resistors, were used for user interaction, enabling menu navigation and system control. The DS1302 RTC module facilitated accurate timestamping of data readings, while the SD card module enabled data logging for long-term analysis and storage. The successful construction of the Weather Monitoring System demonstrated its capabilities in terms of accuracy, reliability, and real-time monitoring. The integration of Arduino Mega, along with the BME280, SGP30, MQ135, LCD display, push buttons, 10kohm resistors, DS1302 RTC module, and SD card module, provided a comprehensive solution for weather data collection, analysis, and visualization. This project contributes to the advancement of weather monitoring systems, emphasizing the importance of Arduino-based solutions and sensor integration. It highlights the potential for utilizing such technology to address weather challenges effectively, enabling datadriven decision-making and fostering weather awareness. Overall, the Weather Monitoring System presented in this project report offers a valuable tool for monitoring and analyzing atmospheric conditions, paving the way for future enhancements and applications in various weather monitoring domains.
Environmental Impact of Pre-occupational radon level measurements in medical imaging facilities of a tertiary hospital in south-west Nigeria
(ICSAEES-2024, Lagos, Nigeria, 2024) Aremu, A. A.; Oni, O. M.; Oladipo, A. E.; Oladapo, O. O.; Obafemi, Y. D.; Oniha, M. I.; Babarimisa, I. O.; James, U. E.
Radiation facilities are placed in an enclosed environment to prevent scattered radiation from getting out of the room, by so doing the rooms foil gas exchange from the outdoor environment, thereby increasing the radon concentration in the indoor air. This study aimed at estimating the occupational radon exposure level in medical facility room in order to estimate the radiological risk in such environment. RAD7 electronic device was used to measure theindoor radon concentration in the five proposed roomsin the newly built Radiology department of a University Teaching Hospital while a digital thermometer was used to measure the ambient temperature. The radon concentrations ranged between 12.09Bq/m3and 58.52 Bq/m3. The ultrasound room has the least average value of 12.09 Bqm-3 and the Fluoroscopy room has the maximum average value of 58.52 Bqm-3. The radon level translated into the effective dose, working level and excess life-time cancer risk for any worker staying for a period of nine hours per day, over a year. Fluoroscopy facility was estimated to present the highest annual absorbed dose and annual effective dose with 0.73 mSvy-1 and 0.8858 mSv y-1, respectively.The mean radon concentration for the five rooms was 41.96Bq/m3. The calculated annual effective dose rate and the mean annual absorbed dose rate to the lung within the radiation facilities rooms were 0.529 mSvy- 1and 0.6350 mSv y-1, respectively.The indoor radon concentrations measured and the effective dose value of 200 Bq/m3 and 1 mSvy-1 respectively is below the reference limitset by International Commission Radiation Protection (ICRP) Agency.This implies that the radiation facility rooms are in conformity with international best practices and this is in agreement with SDG 3 (Good Health and well –being)
Development and Evaluation of Efficient Smart Solar Lawn Mower
(7th International Conference on Science and Sustainable Development and Workshop, 2024) Onuabuchi, E. M.; Ekeopara, J. U.; Sule, Rasidi; Ayanbisi, O.; Akinwumi, S. A.; Olawole, O. C.; Ogunwale, E.
Solar powered lawn mower has offered a more convenient way of trimming the lawn due to the advancement in its technology. As the world gradually moves towards green technology, research has geared towards making solar powered mover readily available, efficient, and economical. However, few reports were available on the effect of grass types on battery voltage drop. In this paper, solar powered lawn mower was structured into phases which include, power supply phase, Arduino phase, motor phase and integration of the components. The 550-motor was sufficient to produce the required torque needed to drive the solar panel mower. The average efficiency of the solar panel was found to be 93 %. The battery voltage drop was investigated upon cutting different types of grasses to determine the rate at which power is dissipated in the solar powered lawn mower. The voltage drop of 0.34 V was recorded when cutting stubborn grass while that of soft grass was found to be 0.17 V. Rain sensor was incorporated to provide the user with a notification via Buzzer whenever raindrops are detected.
Environmental assessment of radionuclide exposure in packaged borehole water exploited from crystalline rocks in Ogbomoso
(ICSAEES-2024, Lagos, Nigeria, 2024) Oladipo, A. E.; Aremu, A. A.; Adeniji, A. A.; Ayinla, T. O.; Babarimisa, I. O.; Morakinyo, R. O.; Araka, I. O.; James, U. E.
The amounts of naturally occurring radionuclides (40K, 238U and 232Th) in packaged borehole water manufacture have been investigated in this work. Furthermore, the buildup of radioactive materials in drinking water presents a direct path for human population exposure to internal radiation. The amount of radioactivity in the processed and unprocessed water samples was measured using gamma spectrometry and a computer-resident quantum multichannel analyser (MCA 2100R) connected to a well-calibrated and shielded NaI (Tl) detector. From the results, it was revealed that the values of activity concentration of processed water ranges between 50.46 ± 3.14 Bq/L to 102.18 ± 14.07 Bq/L, 7.92 ± 4.46 to 16.71 Bq/L, and 10.00 ± 0.84 Bq/L to 14.87 ± 4.03 Bq/L for 40K, 238U and 232Th, respectively. Also, the results obtained for the activity concentration of unprocessed water ranges between 74.51 ± 3.51 Bq/L to 102.21 ± 7.23 Bq/L, 14.86 ± 1.91 Bq/L to 19.87 ± 3.10 Bq/L and 10.00 ± 3.36 Bq/L to 17.79 ± 4.43 Bq/L for 40K, 238U and 232Th, respectively. The results confirmed the presence of40K as a principal occurring radionuclide in the water samples. The annual effective dose for processed water ranges from 0.012 to 0.017 mSyr-1, while it ranges between 0.015 and 0.020 mSyr-1 for unprocessed water. Results in the present study fall below 0.1 mSyr-1, which is the acceptable limit recommended by International Commission on Radiological Protection standard value.
Parameter Estimation of Cellular Communication Systems Models in Computational MATLAB Environment: A Systematic Solver-based Numerical Optimization Approaches
(I. J. Computer Network and Information Security, 2024-06-08) Isabona, Joseph; Akinwumi, Sayo A.; Arijaje, Theophilus E.; Ituabhor, Odesanya; Imoize, Agbotiname Lucky
Model-based parameter estimation, identification, and optimisation play a dominant role in many aspects of physical and operational processes in applied sciences, engineering, and other related disciplines. The intricate task involves engaging and fitting the most appropriate parametric model with nonlinear or linear features to experimental field datasets priori to selecting the best optimisation algorithm with the best configuration. Thus, the task is usually geared towards solving a clear optimsation problem. In this paper, a systematic-stepwise approach has been employed to review and benchmark six numerical-based optimization algorithms in MATLAB computational Environment. The algorithms include the Gradient Descent (GRA), Levenberg-Marguardt (LEM), Quasi-Newton (QAN), Gauss-Newton (GUN), Nelda-Meald (NEM), and Trust-Region-Dogleg (TRD). This has been accomplished by engaging them to solve an intricate radio frequency propagation modelling and parametric estimation in connection with practical spatial signal data. The spatial signal data were obtained via real-time field drive test conducted around six eNodeBs transmitters, with case studies taken from different terrains where 4G LTE transmitters are operational. Accordingly, three criteria in connection with rate of convergence Results show that the approximate hessian-based QAN algorithm, followed by the LEM algorithm yielded the best results in optimizing and estimating the RF propagation models parameters. The resultant approach and output of this paper will be of countless assets in assisting the end-users to select the most preferable optimization algorithm to handle their respective intricate problems.
Synthesis of mesoporous TiO2 using aloe vera extract for solar cell applications
(Case Studies in Chemical and Environmental Engineering, 2024-11) Rasidi, Sule; Utibe, Etop James
Research has been geared towards the reduction of the cost of fabricating semiconductor materials for solar cells. Biosynthesis of Titanium dioxide (TiO 2 ) has gained scientific attention recently due to its environmentally friendly nature. However, achieving the goal of purely green and sustainable materials is still a challenge. In this study, anatase TiO 2 was synthesized from 100 ml aloe vera extract and 4 ml Titanium Tetra Isopropoxide (TTIP). The SEM images showed cluster spherical and irregular shaped particles. The electrochemical results revealed that the TiO 2 sustainability.
Modelling and Prediction of Satellite Signal Path Loss using the ARIMA models at Ku-band in Lagos State, South Western Nigeria
(ICSSD 2024 (IOP Conf. Series: Earth and Environmental Science), 2025) Arijaje, T. E.; Omotosho, T. V; Aizebeokhai, A. P.; Akinwumi S. A.; Oyeyemi, K. D.
Satellite signal path loss is the reduction of signal strength between the transmitting satellite and the receiving antennas on the earth surface. It is cause by effects such as reflection, free space loss, diffraction, refraction and absorption. It is also cause as a results of the environment, terrain contours, medium of propagation, height of antennas location and transmitting distance between the transmitter and receiver. Several methods such as the traditional methods and machine learning techniques have been explored. However, statistical method of path loss prediction has been completely utilized. In this work, prediction of path loss using the autoregressive integrated moving average (ARIMA) technique was considered. Four different ARIMA models at Ku-band were explored using eight years in Lagos State. The method consists of some steps in the run time analysis: the first stage involved identifying the ARIMA model by creating an Autocorrelation Function (ACF) and Partial Autocorrelation Function (PACF) plots and checking if the data are stationary. The second stage involved estimating the ARIMA model, which consists in testing the parameters' significance after obtaining the model's parameters. The ARIMA model is adopted if the parameters are significant. The third stage involved diagnostic checking, in which a test was carried out to see if the adopted model was statistically significant. The fourth stage involves predicting the path loss after the diagnostic process using the adopted or selected ARIMA model. From the analysis, it can be concluded that the best ARIMA model for path loss prediction in Lagos at Ku-band is ARIMA (1,0,0). The ARIMA (1,0,0) model is a better path loss prediction model than the other ARIMA models, indicating that the model parameters are significant at 0.05 with the slightest MSE error, thereby meeting the test of independence. Therefore, for sitting and planning of radio signal propagation technologies in the study location, policy-makers and engineers in telecommunication industry in Nigeria can take advantage of the results within the area of study towards sustainable tele-communication and infrastructure (SDG goal 9).
Assessing subsurface heterogenenity and infiltration capacity at a restored wetland using geophysical imaging and infiltration tests
(2025) Otchere, Nana-Aboagye; Aizebeokhai, Ahzegbobor P.; Martin-Hayden, James; Doro, Kennedy O.
Wetland soil properties and stratigraphic heterogeneity influence their water-holding capacity, 15 infiltration, and subsurface flow. Infiltration, however, depends on the soil’s saturated hydraulic 16 conductivity (Ksat) whose spatial variability at field scale is difficult to quantify. In this study, we 17 combined electromagnetic imaging (EMI) and electrical resistivity (ER) with infiltration tests to 18 assess the spatial variation in the shallow subsurface stratigraphy and Ksat at a restored wetland in 19 northwest Ohio. We used a Geonics EM38-MK2, with a transmitter and two receivers spaced 0.5 20 and 1.0 m to map the spatial distribution of the soil’s apparent electrical conductivity (ECa). The 21 ER measurements were acquired along nine transects using a SuperSting R8 resistivity meter 22 with 84-electrode and a dipole-dipole electrode array. The ER results, constrained with 23 lithostratigraphic logs, showed 0.7 m thick topsoil (silty loam) underlain by 0.5 m thick clayey 24 loam interspersed with coarser materials and alternating units of diamictons. The observed ECa 25 were relatively higher (10 – 40 mS/m) for the 0.5 m T-R spacing compared to the 1.0 m spacing 26 (8 – 36 mS/m). The spatial distribution of Ksat ranged from 0.01 – 0.9 mm/min with higher 27 values at areas with high silt and sand content. A least-squared linear regression between Ksat 28 and ECa yielded coefficient of determination (R2) values >0.62 indicating the effectiveness of 29 EMI for predicting the spatial variation of Ksat. Thus, combining geophysical imaging with field 30 infiltration tests provided valuable insights into infiltration through the soil and potential 31 subsurface flow at the restored wetland with limited details on subsurface flow.