I.A. Fuwape

Michael and Cecilia Ibru University | MCIU · Industrial Physics

Anthropogenic and natural aerosol emissions poses a threat to human and animal health. Particulate matter has a complex relationship with atmospheric parameters. In this study, the multifractal detrended fluctuation analysis was used to investigate complexity in particulate matter and atmospheric parameters at five small time steps (6, 8, 10, 12, a...

In recent times, the COVID-19 pandemic has been the subject of global concern. It has so far claimed over 5.4 million lives globally, with over 291 million cases recorded worldwide as of 5 January 2022. It is known to have different waves and variants, thus making it difficult to handle/manage. This study investigates the impact of the first and se...

The use of satellite and reanalysis weather product is gaining traction in the scientific community especially in developing worlds where in situ data are sparse. Tropical locations have dynamic and widely variable climate which needs to be continuously monitored. The efficiency of these products in capturing the climatic dynamics of these regions...

This study focuses on investigating the chaotic and multifractal behavior of atmospheric time series of solar radiation (solar), maximum temperature (Tmax), and minimum temperature (Tmin) over Lagos State for a period of 24 years. Chaotic quantifiers such as sample entropy, Lyapunov exponent, and correlation dimension were employed to unveil the ch...

The dynamical nature of COVID‐19 cases in different parts of the world requires robust mathematical approaches for prediction and forecasting. In this study, we aim to (a) forecast future COVID‐19 cases based on past infections, (b) predict current COVID‐19 cases using PM2.5, temperature, and humidity data, using four different machine learning cla...

The paper investigates a new hybrid synchronization called modified hybrid synchronization (MHS) via the active control technique. Using the active control technique, stable controllers which enable the realization of the coexistence of complete synchronization and anti-synchronization in four identical fractional order chaotic systems were derived...

Complex systems such as river flow do not obey the law of linearity but most often than not behave in a nonlinear manner. In this study, the dynamics of the River Niger discharge along two stations located in Nigeria were investigated using the methods of phase space reconstruction, correlation dimension and Lyapunov exponent. The analysis was carr...

The dynamical complexities of the Nigerian stock market have been largely uninvestigated. In this study, we analysed the return price of financial stocks on Nigerian Stock Exchange for chaotic behaviour. Our analysis was conducted for the period 2000–2015, as well as for three distinct periods covering the pre-crisis, crisis and post-crisis period...

The use of Moringa oleifera seeds for purifying water has been attempted locally in various forms without putting scientific potency of the material into consideration. The cellulose sample isolated from Moringa {oleifera} seed was characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectr...

In this research, nanocellulose is isolated from Moringa oleifera seed using acid hydrolysis and the structural properties were determined. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy were used for the characterization of the isolated nanocellulose. The most noticeable peak is observed at and the value of the crystall...

Satellite communication systems suffer from the systematic error of tropospheric delay. Accurate estimation of this delay is essential for communication budget and planning. This study investigates the tropospheric delay in three Nigeria cities: Abuja, Lagos, Port Harcourt using two different models (Saastominen and Hopfield). Three-year atmospheri...

The dynamical complexities of geospace has been examined by investigating the characteristic chaotic properties of hourly Dst values obtained from the World Data Center for Geomagnetism, Kyoto, over four solar cycles (1964–2008) using nonlinear methods: sample entropy, Lyapunov exponents, correlation dimension, recurrence quantification analysis, a...

Air and soil temperatures are important agrometeorological variables with several applications. Understanding the complex behavior of air and soil temperatures, as well as their interaction, will help in agricultural planning. Multifractal detrended fluctuation and multifractal cross-correlation analysis of air and soil temperatures were carried ou...

The COVID-19 global pandemic has necessitated some drastic measures to curb its spread. Several countries around the world instituted partial or total lockdown as part of the control measures for the pandemic. This presented a unique opportunity to study air pollution under reduced human activities. In this study, we investigated the impact of the...

Understanding the dynamics of rainfall is important for maximizing the agricultural potential, environmental planning, as well as policy development. In this study, a two-state second-order Markov chain model was developed for the annual and daily occurrence of different rainfall sequences in Ibadan, southwestern Nigeria. The annual variation was a...

There is the need to understand the trend and impact of extreme temperature on coastal cities because they are generally susceptible to extreme precipitation events. This study explores the trend in extreme temperature for Lagos State, Nigeria. The indices for daily minimum and maximum temperature data was calculated for the period 1991–2015 using...

Indoor radon (²²²Rn) measurements were carried out using solid state nuclear track detectors (SSNTD) in some dwellings from southwestern Nigeria. This was aimed at statistically assessing influence of building characteristics on the measured radon and estimating excess lifetime cancer risks (ELCR). The measured radon concentrations followed lognorm...

Africa tends to be isolated and sometimes forgotten when it comes to scientific research and in particular physics. But the region has great potential, being home to the youngest population in the world, and despite a variety of issues, there has been steady, albeit uneven progress towards establishing a scientific infrastructure. Ten African resea...

Cadmium telluride (CdTe) doped nanocellulose thin films were successfully deposited on glass/fluorine-doped tin oxide substrates from an aqueous electrolyte bath containing hydrated cadmium sulfate (3CdSO4·8H2O) and tellurium dioxide using electrodeposition technique. Six samples of CdTe thin films were grown with nanocellulose concentrations of (0...

The complexity in atmospheric parameters not only place a limit on their predictability but also influence their mutual interaction. Our goal in this research is to investigate (i) the nonlinear characteristics, and (ii) nonlinear interaction patterns amongst twelve teleconnection indices including Atlantic Multidecadal Oscillation (AMO), North Atl...

The development of a solar concentrator dryer using locally made materials consisting of three main components: the drying chamber, the solar collector and the absorber. A constructed measuring device with logger which is the electronic system was used to monitor the temperature, moisture content and light intensity during the drying process. The d...

Understanding the dynamics of climate extremes is important in its prediction and modelling. In this study, linear trends in percentile, threshold, absolute, and duration-based temperature and precipitation extremes indicator were obtained from 1979 to 2012 using the ETCCDI data set. The pattern of trend was compared with nonlinear measures (Entrop...

Practical implementation of synchronization schemes is important for secure communication. With many systems available, simple systems with varying differences will prove pertinent in user identification and inter-operability of communicating units. The implementation of Chua's circuit with different memristors is a potential candidate for the real...

In this study, the dynamical complexities associated with the global sea surface temperature (SST) was investigated. Monthly time series of global SST on a grid of 2 • × 2 • from January 1854 to June 2019 was analyzed using Hurst exponent, sample entropy, Lyapunov exponent and correlation dimension. Global ocean temperature was found to have predom...

Noise play a creative role in the evolution of periodic and complex systems which are essential for continuous performance of the system. The interaction of noise generated within one component of a chaotic system with other component in a linear or nonlinear interaction is crucial for system performance and stability. These types of noise are inhe...

Gamma ray spectra of natural radioactivity from ²³⁸U, ²³²Th, and ⁴⁰K in sediments and water samples from rivers in eleven oil-producing and two non-oil producing communities in Delta state of Nigeria have been evaluated using gamma-ray spectrometer with the hyper-pure germanium detector. Measured activity concentrations in water samples ranged from...

This study investigates the linear and nonlinear dynamics of precipitation and temperature extremes. Monthly daily temperature range (DTR) and maximum 5-day precipitation (RX5) data for sixty three years were obtained from the archives of the Expert Team on Climate Change Detection and Indices (ETCCDI). Spatial maps were constructed for the descrip...

Temporal variations of soil volumetric water content (VWC) at three locations in tropical Nigeria were investigated using data from the Tropospheric Data Acquisition Network. Inland stations show maximum VWC values in the evening, whereas coastal areas show maximum values at noon. During the wet season, high and variable VWC values occur at each st...

Nigeria has seen an improvement in the number of girls and women choosing careers in physics. The mentoring efforts of the few role models are beginning to yield significant results. The IUPAP Working Group of Women in Physics in Nigeria (WGWIP) continues to hold bi-annual national conferences. In this report, we present the significant progress th...

Discrete fractional order chaotic systems extends the memory capability to capture the discrete nature of physical systems. In this research, the memristive discrete fractional order chaotic system is introduced. The dynamics of the system was studied using bifurcation diagrams and phase space construction. The system was found chaotic with fractio...

The impact of extreme climate such as drought and flooding on agriculture, tourism, migration and peace in Nigeria is immense. There is the need to study the trend and statistics for better planning, preparation and adaptation. In this study, the statistical and temporal variation of climatic indices Standardized Precipitation Index (SPI) and Stand...

The memory effect in fractional calculus has made it a more realistic approach for the practical modeling of real life phenomena ranging from population, electric circuits, etc. In this paper, a discrete fractional order model for the Larva–Pupa–Adult (LPA) beetle population dynamics is proposed. The bifurcation of the proposed model showed novel d...

Noise play a creative role in the evolution of periodic and complex systems which are essential for continuous performance of the system. The interaction of noise generated within one component of a chaotic system with other component in a linear or nonlinear interaction is crucial for system performance and stability. These types of noise are inhe...

Drought poses a significant threat to the delicate economies in subsaharan Africa. This study investigates the influence of large scale ocean oscillation on drought in West Africa. Standardized Precipitation Index for the region was computed using monthly precipitation data from the Climate Research Unit during the period 1961 -1990. The impact of...

Understanding the dynamics of climate extreme is important in its prediction and modeling. In this study, linear trends in percentile, threshold, absolute, and duration based temperature and precipitation extremes indicator were obtained for the period 1979 - 2012 using the ETCCDI data set. The pattern of trend was compared with nonlinear measures...

Satellite communication systems suffer from the systematic error of tropospheric delay. Accurate estimation of this delay is essential for communication budget and planning. This study investigates the tropospheric delay in three Nigeria cities: Abuja, Lagos, Port-Harcourt using two different models (Saastominen and Hopfield). Three year atmospheri...

This study investigates the trend in Rainfall Onset Dates (ROD), Rainfall Cessation Dates (RCD), Length of Growing Seasons (LGS) and Rainfall Amount at Onset of Rainfall (RAO) using linear regression, Mann-Kendall, Sen Slope and Hurst Exponent for four locations in tropical Nigeria and the development of a Fourier based model for ROD and RCD. Daily...

The ability of humans to generate numbers that are really random has always been a subject of debate. This paper investigated the possibility for a group of humans to serve as random number generators. A total of 2344 students, who were not pre-informed to avoid bias, from different faculties within the Federal University of Technology Akure were a...

The impact of extreme climate such as drought and flooding on agriculture, tourism, migration and peace in Nigeria is immense. There is the need to study the trend and statistics for better planning, preparation and adaptation. In this study, the statistical and temporal variation of climatic indices Standardized Precipitation Index (SPI ) and Stan...

The paper investigates a new hybrid synchronization called modified hybrid synchronization (MHS) via the active control technique. Using the active control technique, stable controllers which enable the realization of the coexistence of complete synchronization, anti-synchronization and project synchronization in four identical fractional order cha...

The practicability of wind speed in energy generation is predicated on its predictability. This study aims to investigate chaotic dynamics in wind speed over a tropical location in Nigeria using Tropospheric Data Acquisition Network. Daily, monthly and yearly wind speed data from May 2010-June 2011 were investigated using the 0-1 test and Renyi Ent...

Daily rainfall and temperature data from 47 locations across Nigeria for the 36-year period 1979–2014 were treated to time series analysis technique to investigate some nonlinear trends in rainfall and temperature data. Some quantifiers such as Lyapunov exponents, correlation dimension, and entropy were obtained for the various locations. Positive...

Extrapolation of radio refractivity values across different heights above sea level is necessary for effective communication planning. The difficulty and expenses associated with placing equipment at different heights above sea level has necessitated the use of mathematical tools for estimation of radio refractivity values. Using five different hei...

The importance of synchronization schemes in natural and physical systems including communication modes has made chaotic synchronization an important tool for scientist. Synchronization of chaotic systems are usually conducted without considering the efficiency and robustness of the scheme used. In this work, performance evaluation of three differe...

The use of memristor in the realization of chaotic circuits has gained popularity in recent times. This can be attributed to its simplicity over the traditional Chua’s diode. The memristor as a nanometer-scale passive circuit element which can be described as a resistor with memory and possesses nonlinear characteristics. In this chapter, the numer...

The natural radioactivity levels of soil samples collected from four local government areas in Kogi State, Nigeria were measured using a hyper-pure germanium detector, and the radiological hazard parameters associated with them were estimated. The measured concentration ranged from 7.82 ± 0.63 to 82.22 ± 1.99 Bq kg⁻¹ for ²³⁸U, 11.05 ± 1.10 to 114.8...

Radio refractivity index is used to quantify the effect of atmospheric parameters in communication systems. Scaling and dynamical complexities of radio refractivity across different climatic zones of Nigeria have been studied. Scaling property of the radio refractivity across Nigeria was estimated from the Hurst Exponent obtained using two differen...

This study investigated linear and nonlinear relationship between the amount of rainfall and radio refractivity in a tropical country, Nigeria using forty seven locations scattered across the country. Correlation and Phase synchronization measures were used for the linear and nonlinear relationship respectively. Weak correlation and phase synchroni...

Nigeria is one of the fastest growing economy in the world. This study aims to investigate the dynamics of two important economic indices in Nigeria – All Share Index (ASI) and Gross Domestic Product (GDP) using the Hurst and Entropy measures. Data used in this study were obtained from the Central Bank of Nigeria for the period 1981 – 2012. Results...

The severe limitations of linear tools in analysis of EEG signals have necessitated the development and evaluation of several nonlinear tools for EEG characterizations. This study aims to investigate the performance of the different nonlinear tools in identifying different neurological disorder from EEG signals. Surface recordings of subjects with...

In Nigeria the number of women taking up a career in physics is increasing. The progress made by Nigerian women in physics is presented. The Nigerian Women in Physics working group continues to organize activities to encourage more girls and women into physics. One of such activity is the biannual conference of women in physics in Nigeria. Through...

Chaos has been investigated in the surface radio refractivity data over Akure, Southwestern Nigeria using the Brock-Dechert-Scheinkmen (BDS) test. The data were obtained from the ERA-Interim reanalysis data for a space of eleven years (January 2004 to December 2014). The computed radio refractivity calculated was then examined for chaos using the B...

The quest to find an index for proper characterization and description of the dynamical response of the ionosphere to external influences and its various internal irregularities has led to the study of the day-to-day variations of the chaoticity and dynamical complexity of the ionosphere. This study was conducted using Global Positioning System (GP...

Activity concentrations of twenty-six (26) samples of sediment collected from rivers from eleven (11) oil-producing communities and two (2) non-oil producing communities in Delta state of Nigeria were studied. Hyper Purity Germanium (HPGe) Detector was used for counting and detection of radionuclide content of all samples. Results of the samples an...

The quest to find an index for proper characterization and description of the dynamical response of the ionosphere to external influences and its various internal irregularities has led to the study of the day to day variations of the chaoticity and dynamical complexity of the ionosphere. This study was conducted using Global Positioning System (GP...

This paper presents increased-order generalized synchronization (GS) of chaotic and hyperchaotic systems with different order based on active control technique. By this technique, we design suitable control functions to achieve GS between (i) a new three-dimensional (3D) chaotic system and four-dimensional (4D) hyperchaotic Lorenz system and (ii) f...

The deterministic chaotic behavior and dynamical complexity of the space plasma dynamical system over Nigeria are analyzed in this study and characterized. The study was carried out using GPS (Global Positioning System) TEC (Total Electron Content) time series, measured in the year 2011 at three GPS receiver stations within Nigeria, which lies with...

Although the number of women in physics in Nigeria is increasing, there is still poor enrollment in physics compared with all other science and engineering fields. At the last annual meeting of the Nigerian Institute of Physics, the Association of Women Physicists was formed. It is hoped that the activities of this new group will encourage more wom...

In this study, the Bloch NMR flow equations are modelled into diffusion equation with constant transport coefficient in terms of the NMR transverse magnetization. Mathematical conditions are established for the diffusion coefficients to be constant or spatially varied with direction. When these conditions are met, the diffusion coefficients can the...

Spiking and bursting patterns of neurons are characterized by a high degree of variability. A single neuron can demonstrate endogenously various bursting patterns, changing in response to external disturbances due to synapses, or to intrinsic factors such as channel noise. We argue that in a model of the leech heart interneuron existing variations...

One of the vital ingredients for development of any nation is knowledge of basic science, of which physics is the root source. There is poor enrollment of women in physics at both secondary and tertiary levels of education in Nigeria. Recently, the number of women enrolling in physics in Nigeria has increased slightly, but women are yet to distingu...

We study noise influence on spike-adding transitions in the bursting activity of a Hodgkin-Huxley-type model of the leech heart interneuron. In the noise-free system spike adding occurs via homoclinic bifurcation of a saddle periodic orbit. As a control parameter of the model changes a sequence of spike-adding transitions is observed, accumulating...

In many NMR experiments it is noticed that liquids confined in porous materials exhibit properties that are dif-ferent from those of the bulk fluid. Determining the relationship between macroscopic properties and the microscopic structure of porous materials and their components has been difficult. Despite decades of study, researchers' understand-...

We study information processing in a peripheral sensory receptor system which possesses spontaneous dynamics with two distinct rhythms. Such organization was found in the electrosensory system of paddlefish and is represented by two distinct and unidirectionally coupled oscillators, resulting in biperiodic spontaneous firing patterns of sensory neu...

We study the influence of noise on a spike adding transitions within the bursting activity in a Hodgkin-Huxley-type model of the leech heart interneuron. Spike adding in this model occur via homoclinic bifurcation of a saddle periodic orbit. Although narrow chaotic regions are observed near bifurcation transition, overall bursting dynamics is regul...

The transition route to chaos in low-dimensional nonlinear dynamical systems have been well understood. One of them, the intermittency route, was classified into three types by Pomeau and Manneville. The essential feature of intermittency is that a simple periodic orbit is replaced by a chaotic attractor, where the chaotic behavior resembles that b...

In situ gamma spectroscopy has been employed to characterise natural radiation in the soil at 32 locations in the Delta region of Nigeria. The outdoor gamma dose rates in the air due to 40K, 238U and 232Th in the soil were 1.5 +/- 0.9 nGy h(-1), 6.9 +/- 1.6 nGy h(-1) and 16.3 +/- 3.1 nGy h(-1) respectively. The estimated total annual outdoor effect...