Papers by Sylvester Andrew Ekong
Advances in Materials Science
The literature is flooded with scientific information on most durability properties except water ... more The literature is flooded with scientific information on most durability properties except water absorption coefficient of masonry units like sandcrete blocks. Also, while waste papers disposal is a systemic problem due to ineffectiveness of waste management system in developing countries, the price of cement is on the increase. This situation, ultimately, causes a bane in achievement of low-cost housing development considering the fact that sandcrete blocks are predominantly used as walling elements for such undertakings. In this study, solid core sandcrete blocks were produced with waste paper ash (WPA) utilized as partial replacement of cement at 5 % and 10 % volumetric levels. Chemically, the WPA was found to show similarity with cement in terms of SiO2, Al2O3, and CaO contents. Density and water absorption coefficient of the block samples were determined. While density ranged from 1682 to 1872 kg/m3, water absorption coefficient varied from 27.04 to 23.49 kg/m2h0.5. Statistical...
Pure and Applied Physics, 2015
A quantum Monte Carlo (QMC) study of the electric dipole moment of hydrazine molecule using CASIN... more A quantum Monte Carlo (QMC) study of the electric dipole moment of hydrazine molecule using CASINO-code is presented. The variational quantum Monte Carlo (VQMC) technique used in this work employed the restricted Hartree-Fock (RHF) scheme. The components dependence of the electric dipole moment from the QMC technique is studied with a single determinant Slater-Jastrow trial wave-function obtained from the Hartree-Fock orbitals. The simulation requires that the configurations must evolve on the time scale of the electronic motion, and after equilibration, the estimated effective timestep be obtained. From our result, though the VQMC method showed much fluctuation, the technique calculated the electric dipole moment of hydrazine molecule as 2.0 D, which is in closer agreement with 1.85 D experimental value than others in literature. Thus, the result from this study is found to be precisely approaching the required order of chemical accuracy.
Advances in Materials Science
Coconut husk is generated yearly as waste in large quantities but majorly under-utilized. Also, a... more Coconut husk is generated yearly as waste in large quantities but majorly under-utilized. Also, as a result of high embodied carbon, cement production is one of the largest contributors to construction sector carbon footprint. Since accumulation of unmanaged agro-waste like coconut husk has an increased environmental concern due to its pollution effect, recycling it into sustainable construction materials is a viable solution for future generation. In this study, experiments were performed to investigate the influence of coconut husk ash nanomaterial (CHAN) inclusion on electrical characteristics of plain cement paste (BCP) and mortar (CSM) samples at curing ages of 7 and 28 days. The results showed increase in electrical resistivity, thermal constant, and activation energy with curing duration for heating and cooling cycles of BCP and CSM. With inclusion of CHAN, the developed cement paste (CAP) and mortar (CASM) possessed lower values in all cases compared to their counterparts. A...
Thermodynamic Evaluation of Coshine Yukawa Potential (Cyp) for Some Diatomic Molecule Systems
Within the framework of non-relativistic quantum mechanics, the bound state approximate solution ... more Within the framework of non-relativistic quantum mechanics, the bound state approximate solution of the SE is solved for the coshine Yukawa potential (CYP) using the Nikiforov–Uvarov (NU) method. By employing the Greene-Aldrich-type approximation scheme, we have obtained the explicit energy-eigenvalues and corresponding normalized eigen-functions in closed form for the newly proposed CYP for hydrogen-related diatomic molecules such as hydrogen dimer (H2), lithium hydride (LiH), scandium hydride (ScH) and hydrogen chloride (HCl). The thermodynamic properties are also evaluated including the vibrational partition function, vibrational mean energy, vibrational mean free energy, vibrational entropy and vibrational specific heat capacity. Presented also are some numerical results which show an indication of similar correlation of energies, owing to their ion-ion coupling with regards to similar atomic radii existing among the diatomic molecules.
This paper presents three techniques for configuring, interfacing, and networking of a wireless I... more This paper presents three techniques for configuring, interfacing, and networking of a wireless IP-based camera for real-time security surveillance systems design. The three different real-time implementation techniques proposed for configuring, interfacing, and networking the IP camera are: 1). accessing the IP camera using the Wanscam vendor software, 2). accessing the IP camera via Firefox® web browser, and 3). accessing the IP camera via MATLAB/Simulink
Mapping depths of groundwater-level architecture: implications on modest groundwater-level declines and failures of boreholes in sedimentary environs
Acta Geophysica, 2021
Due to financial wherewithal, only shallow wells, which are extremely prone to seasonal groundwat... more Due to financial wherewithal, only shallow wells, which are extremely prone to seasonal groundwater decline, are constructed in the study area. Generally, new groundwater wells are designed to follow the criteria of the old wells, which may be vulnerable to substantial groundwater depletion through water-level decline. Going by this, newer groundwater wells constructed near older ones are 100% susceptible to the uninvestigated depletion associated with the older ones. The method used integrates vertical electrical sounding (VES) technique employing the Schlumberger electrode configuration, which measured the resistivity of geologic layers, depths and thickness with hydrogeological information, which constrained the VES interpretation. The aim was to check the spread of groundwater depth–water table ratios for the shallow aquifers. The 1-D resistivity analysis shows that the topsoil/motley topsoil has resistivity ranging from 71.8 to 1964.1 Ωm\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\Omega m$$\end{document} and mean 586.9 Ωm\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\Omega m$$\end{document}, while its depth ranges between 0.5 and 11.3 m with mean value of 2.8 m. In layer 2, while the resistivity spans between 71.3 and 1488.6 Ωm\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\Omega m$$\end{document} with mean value 444.6 Ωm\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\Omega m$$\end{document}, the depth and thickness, respectively, have a range and mean value of 2.0–170.4 m and 41.9 m and 3.4–112.2 m and 41.0 m. The third layer resistivity ranges from 7.5 to 2332.5 Ωm\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\Omega m$$\end{document} with mean value of 797.2 m. The depth of burial and the thickness of the third layer, respectively, have mean of 63.0 m and 74.6 m and range of 40.3–106.3 m and 50.1–115.6 m. The fourth layer penetrated by current at 150 m half of current electrode separation has undefined thickness and depth with respective resistivity range and mean of 25.3–2385.3 Ωm\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\Omega m$$\end{document} and 508.4 Ωm\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\Omega m$$\end{document}. Based on the resistivity results and nearby borehole data, sizeable numbers of borehole in the area have depths (between 40 and 80 m) that are remarkably greater than the water table depths (1.4–37.6 m). A few boreholes have depths that are sparingly greater than water levels and by the present climate change; they are not likely to be depleted by virtue of water-level declines as the well depth–water table depth ratios are still sustainable to ward off the depletion associated with water-level decline. The results indicate the spatial spread of shallow hydrogeological units as well as the water-level architecture, which is believed to provide useful information that will complement lithological logs while planning for newer groundwater well development in the area.
Mass spectrum of heavy quarkonium for screened Kratzer potential (SKP) using series expansion method
The European Physical Journal Plus, 2021
In this study, the radial Schrödinger equation is solved with the screened Kratzer potential usin... more In this study, the radial Schrödinger equation is solved with the screened Kratzer potential using the series expansion method. The bound state energy spectra are obtained. To check the correctness of the result obtained from this method, we carry out suitable adjustments to the screened Kratzer potential parameters resulting in potential models, such as the Kratzer and Coulomb potentials are deduced as special cases. The numerical values of the energy spectra of the special cases (Kratzer potential) for hydrogen chloride and lithium hydride diatomic molecules are computed for different quantum numbers; n and l and the results are in consonance with the theoretical works of similar investigation. The expression for the energy spectra is applied to obtain the mass spectra of heavy quarkonium systems (charmonium and bottomonium). The numerical results agree with the experimental values and theoretical studies in previous works. Our results will have possible applications in high energy physics, molecular physics, etc.
This paper presents three techniques for configuring, interfacing and networking of a wireless IP... more This paper presents three techniques for configuring, interfacing and networking of a wireless IP-based camera for real-time security surveillance systems design. The three different real-time implementation techniques proposed for configuring, interfacing and networking the IP camera are: 1). accessing the IP-based camera using the Wanscam vendor software, 2). accessing the IP-based camera via Firefox ® web browser and 3). accessing the IP-based camera via MATLAB/Simulink®. The paper also demonstrates the interfacing and networking of the IP-based camera with multiple computers using an Ethernet switch. The live streaming video based on the proposed techniques can be adapted for image detection, recognition and tracking for real-time intelligent security surveillance systems design. Keywords—Closed-circuit television (CCTV), Internet protocol (IP), security surveillance, wireless networking
ABSTRACT. Quantum Monte Carlo (QMC) calculations of the electric dipole moment and ground-state t... more ABSTRACT. Quantum Monte Carlo (QMC) calculations of the electric dipole moment and ground-state total energy of hydrazine (N 2 H 4 ) molecule using CASINO-code have been carried-out by employing the VMC and DMC techniques. The optimization of the Slater-Jastrow trial wavefunction was done using variance-minimization scheme. The simulations require that the configurations must evolve on the time scale of the electronic motion, and after equilibration, the estimated effective time-step be obtained. In this study, the electric dipole moment of N 2 H 4 molecule was calculated using only the DMC technique; and a value of 2.0D which is in good agreement with the experimental value of 1.85D was obtained. On the other hand, the ground-state total energy of N 2 H 4 molecule was calculated using both VMC and DMC methods. It was observed that the result obtained from the VMC technique agrees very-well with the best theoretical value
Pure and Applied Physics, 2015
Three mathematical model structures, namely: ARMAX, OE and a SSIF are first formulated followed b... more Three mathematical model structures, namely: ARMAX, OE and a SSIF are first formulated followed by the formulation of their respective model predictors for the model identification and prediction of power transmission and distribution within Akure and its environs. A total of 51,350 data samples from the Power Holding Company of Nigeria were collected for thirteen different parameters that influences the evaluation and analysis in the case study area. The performances of these three model predictors are validated by one-step and five-step ahead prediction methods as well as the Akaike’s final prediction error (AFPE) estimates. The results obtained from the application of these three model structures and their predictors for the modeling and prediction of power transmission and distribution as well as the validation results show that the OE model predictor outperforms the ARMAX and SSIF model predictors with much smaller prediction errors, good prediction and tracking capabilities an...
Valorisation of Waste Carton Paper, Melon Seed Husks, and Groundnut Shells to Thermal Insulation Panels for Structural Applications
Polytechnica
A quantum Monte Carlo (QMC) study of the electric dipole moment of hydrazine molecule using CASIN... more A quantum Monte Carlo (QMC) study of the electric dipole moment of hydrazine molecule using CASINO-code is presented. The variational quantum Monte Carlo (VQMC) technique used in this work employed the restricted Hartree-Fock (RHF) scheme. The components dependence of the electric dipole moment from the QMC technique is studied with a single determinant Slater-Jastrow trial wave-function obtained from the Hartree-Fock orbitals. The simulation requires that the configurations must evolve on the time scale of the electronic motion, and after equilibration, the estimated effective timestep be obtained. From our result, though the VQMC method showed much fluctuation, the technique calculated the electric dipole moment of hydrazine molecule as 2.0 D, which is in closer agreement with 1.85 D experimental value than others in literature. Thus, the result from this study is found to be precisely approaching the required order of chemical accuracy. Keywords : CASINO code, Electric dipole mom...
Ground-State Energy Calculation of Helium Atom Using Quantum Monte Carlo CASINO-Code
We report an improved variational Monte Carlo (VMC) calculation of the ground-state energy of the... more We report an improved variational Monte Carlo (VMC) calculation of the ground-state energy of the helium atom, using quantum Monte Carlo (QMC) CASINO – code. The VMC ground-state energy is studied with a single determinant Slater-Jastrow trial wave-function formed from Hartree-Fock orbitals. The optimization of orbitals improved the agreement between the variational Monte Carlo and recent experiment. The calculated ground-state energy result is –2.903692762 ± 0.000023 a.u., which is in good agreement with the most recent experimental value –2.903693775 a.u. obtained by Bergeson et al. A more accurate trial function for importance sampling and the use of Jastrow–function combine to yield a ground-state energy which is 5 significant figures more accurate than that of previous quantum Monte Carlo calculations. Keywords: CASINO code, QMC, VMC, Helium atom, Reblocked-standard-error
The Design and Devlopment of an Automatic Hardware-Oriented Hot-Coffee Dispensing Machine
ABSTRACT
Investigation of Thermal and Strength Properties of Composite Panels Fabricated with Plaster of Paris for Insulation in Buildings
International Journal of Thermophysics
Investigation of Thermal and Strength Properties of Composite Panels Fabricated with Plaster of Paris for Insulation in Buildings
International Journal of Thermophysics
International Letters of Chemistry, Physics and Astronomy, 2016
We have employed a quantum confinement (QC) model to the study of different shapes of nanocrystal... more We have employed a quantum confinement (QC) model to the study of different shapes of nanocrystalline silicon (nc-Si) quantum dot. Each dots (shapes), although within the limits of an effective diameter of 3nm, exhibits divergence leading to different electronic energy based on the transitions from the quantum selection rule. Also, the graphical representation of the energies from each shape as a function of the effective diameter gives a qualitatively similar spectrum of discrete energies. The results obtained in this work using QC model are in good agreement with experiment and other models in literature.
International Letters of Chemistry, Physics and Astronomy, 2016
This paper aims at determining the total energy and bond lengths of some polyatomic organic molec... more This paper aims at determining the total energy and bond lengths of some polyatomic organic molecules, using quantum Monte Carlo (QMC) CASINO-code. The QMC code employed the VMC and DMC methods in the computations with emphasis on DMC, and using Slater-Jastrow trial wave-function formed from Hartree-Fock orbitals. The calculated results show that our reported values are in good agreement with the experimental values of both Hehre et al., and Linus Pauling. The total energies obtained in this study are 6 significant figures more accurate than those of previous studies.
International Letters of Chemistry, Physics and Astronomy, 2015
Quantum Monte Carlo (QMC) calculations of the electric dipole moment and ground-state total energ... more Quantum Monte Carlo (QMC) calculations of the electric dipole moment and ground-state total energy of hydrazine (N 2 H 4) molecule using CASINO-code have been carried-out by employing the VMC and DMC techniques. The optimization of the Slater-Jastrow trial wavefunction was done using variance-minimization scheme. The simulations require that the configurations must evolve on the time scale of the electronic motion, and after equilibration, the estimated effective time-step be obtained. In this study, the electric dipole moment of N 2 H 4 molecule was calculated using only the DMC technique; and a value of 2.0D which is in good agreement with the experimental value of 1.85D was obtained. On the other hand, the ground-state total energy of N 2 H 4 molecule was calculated using both VMC and DMC methods. It was observed that the result obtained from the VMC technique agrees very-well with the best theoretical value [17], but the DMC technique gave a ground-state total energy lower than all other theoretical values in literature, suggesting that the DMC result of-111.842774 ± 0.00394 a.u. may be the exact ground-state total energy of hydrazine molecule. The calculated values of electric dipole moment and ground-state total energy in this work are compared with the available experimental values and the values reported by different workers. Reasonably good agreement has been obtained between them in the required order of chemical accuracy.
The Design and Devlopment of an Automatic Hardware-Oriented Hot-Coffee Dispensing Machine
ABSTRACT
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Papers by Sylvester Andrew Ekong