Evaluation of PV performance prediction model in tropical environment in Senegal
April 2021
Many authors in the literature have worked on models for producing PV module performance, but the question of a climate-specific model is problematic. Some studies have shown more appropriate models for any PV module technology, while others have highlighted models that are more appropriate for a given climate. The aim of this work is to evaluate our model which is based on the I-V characteristic and their accuracy was...
Evaluation of the anti-microbial efficiency of scrap metal-based coagulant and local salt modified-biomaterials for point-of-use water treatment
March 2021
The anti-microbial efficiency of a composite material formulated from a scrap metal-based (iron (III) sulphate) coagulant and indigenous salt (NaCl) activated biomaterials (coconut shell carbon and counter wood) were evaluated by using the composite materials as coagulant and disinfectant adsorbent by treating borehole water and river samples at point-of-use. The results of the microbial analysis of the untreated and...
Test of velocity-displacement estimation using variometric method under the condition of ionospheric scintillation during equinoctial months of solar maximum period 2012
February 2021
The Global Navigation Satellite System (GNSS) technologies have made significant contribution to seismology studies. Some processing strategies are well known, like real time PPP and DGPS techniques. These two methods have been widely used for GNSS based seismic activities monitoring. The first method requires accurate models of GNSS measurement errors to achieve accuracy in centimeter (cm) and need convergence time in...
Stability and elastic anisotropy of diamond related C8-yBy materials
February 2021
A number of potentially super-hard materials were examined using ab-initio methods. Low Gibbs free energy polymorphs of diamond-like materials for y = 0 to 7 in the stoichiometric type C8-y By, were identified at absolute zero of temperature. These were proposed as possible super-hard materials with useful applications. The materials with y = 0 to 3, that is, diamond (C), cubic C7B (c-C7B), rhombohedral C3B (r-C3B) and...
Evaluation of simulated rain-based attenuation techniques at k-v frequency bands for satellite services under different modulation techniques over Southwestern Nigeria
January 2021
Rain-based attenuation (RBA) is a major deteriorating factor affecting radio wave signals operating at microwave and millimetre wave bands for a typical Earth-Space Communication Link (ESCL). Although the international telecommunication union (ITU) recommended a standard model for predicting RBA along the terrestrial and ESCL, the technique underperforms in tropical environments. However, the model can be supported by...
Coherent perfect absorption in plasmonic planar metasurface
December 2020
The coherent perfect absorption (CPA) for a planar resonator of silver has been elaborated here in numerical and analytical approaches. It is investigated numerically in different geometrical shapes and spectral regimes. The CPA mode is observed to be spectrally sensitive to the geometry of the resonator. The scattering matrix method is employed in theoretical analysis. The CPA conditions and output irradiance...
Analysis and feasibility of 50 kWp self-consumption solar photovoltaic system for four Senegalese typical climatic zones using PVsyst software
December 2020
This study investigates analysis and feasibility of 50 kWp self-consumption photovoltaic system used for supplying the electrical load of military bases in Senegal. It refers to a simulation of performance photovoltaic system in four Senegalese typical climatic zones. In constructing the 50 kWp self-consumption photovoltaic simulation, the number of modules is 144, the power of each module is 280 Wp, 18 modules are in...
Fof2 prediction with IRI-2016 at Dakar Station during quiet activity over solar cycles 21 and 22
October 2020
This study deals with comparison between Dakar station ionospheric’s F2 layer critical frequency (foF2) data and the two subroutines (CCIR and URSI) of IRI-2016 model predictions. Comparisons are made for very quiet geomagnetic activity during the four phases of the solar cycles 21 and 22 (minimum, increasing, maximum and decreasing). Model's predictions are suitable with observed data by day than by night....
Modification of plastic tank for bio-digestion of food wastes for biogas generation for cooking foods
October 2020
The anaerobic states of the modified bio-digester and potentials of the generated biogas in cooking foods were evaluated. The study adopted experimental design. Data generated were analyzed using one - way analysis of variance and independent t-test. Carbon, free fatty acid, chemical and biochemical oxygen demand decreased significantly (p<0.05) while moisture and protein contents of the wastes increased...
Optical and scanning kelvin probe microscopic characterization of sol-gel synthesized aluminum doped zinc cobalt ferrite nanoparticles
October 2020
In this work, Zn1-xCoFe2AlxO4 (x=0, 0.2, 0.4, 0.6, 0.8 and 1.0) ferrites were synthesized using the sol-gel method. XRD analysis was done and confirmed the formation of spinel structure, where the particle size and lattice parameter decrease with increase of aluminum concentration. This may be attributed to a shift of the bigger Al3+ ions, from the tetrahedral to the octahedral sites, interchanging with smaller Zn2+...
Preparation of MWCNT/Ba0.2Sr0.2La0.6MnO3/PANI nanocomposites and investigation of its electromagnetic properties in KU-band
October 2020
The aim of this study was enhanced the absorption of electromagnetic waves by nanocomposite containing polyaniline (PANI), functionalized multi wall carbon nanotubes (MWCNTs) in the presence of magnetic Ba0.2Sr0.2La0.6MnO3 nanoparticles (NPs). At First MWCNTs was functionalized by 3:1 ratio of sulfuric and nitric acid, then functionalized MWCNTs was coated by NPs with the traditional sol-gel method. In the final step,...
Effects of elevated humidity on stratospheric ozone content in the tropics
October 2020
This study examines the effects of elevated humidity on stratospheric ozone content in the tropics, a case study of Nigeria. The specific stations in Nigeria studied with their co-ordinate include Makurdi (7.7°N 8.5°E), Maiduguri (11.9°N 13.2°E), Kano (12.0°N 8.5°E), Port-Harcourt (4.9°N 7.0°E) and Lagos (6.5°N 3.4°E). Using monthly mean stratospheric ozone data from Earth Probe...
River water lever sensor as river flood warning system
October 2020
Senate Report recorded last 2013 show that tropical storms and floods are the principal disasters with 102 and 72 occurrences, respectively. Distinctly, flood is still one of the biggest problems of the country. Statistics shows that 31.9% of the natural disasters, which occur in the Philippines in the years 1990-2014, are attributed to flood related episodes with a mortality rate of 5.9%. The researchers seek to...
Application of integrated geophysical methods in environmental studies: A case study of oil spillage in Thange Area Makueni County, Kenya
August 2020
This research was conducted with the aim of mapping the extent of soil and ground water hydrocarbon contamination from an oil pipeline leak point within the area. An integrated geophysical survey approach involving horizontal electrical profiling (HEP), vertical electrical sounding (VES) and Gravity Survey was applied. Resistivity and gravity lows were identified as aquifer zones confined within basalts and potential...
Variations in equatorial electrojet current along the 210ºMM chain: A comparison of two approaches
August 2020
Variations of equatorial electrojet (EEJ) in six Magnetic Data Acquisition System (MAGDAS) stations (four stations within the magnetic equator region and two stations outside the region) on the 210ºMagnetic Meridian (MM) chain were examined. Data of hourly values of horizontal component of magnetic field, H in the year 2007 for Cooktown (CKT), Amami-oh-Shima (AMA), Davao (DAV), Langkawi (LKW), Yap- Island (YAP) and...
Application of the alternative variational iteration method to solve delay differential equations
July 2020
In this paper, alternative variational iteration method (AVIM) is presented to solve linear and nonlinear delay differential equations (DDEs). A general lagrange multiplier is used to construct a correction functional. The proposed series solutions are found to converge to exact solution rapidly. The computation of three test examples of DDEs was presented to confirm the efficacy and validity of AVIM. The results...
Simulating ionosphere parameters by thermosphere-ionosphere-electrodynamics general circulation model
July 2020
Ionosphere region is the part of atmosphere layer where radio waves reflect for telecommunication. This is due to its composition in particles. Solar radiation hit particles in ionosphere. This phenomenon causes an ionization of particles in the ionosphere. According to the particles density in this region, radio waves emitted in telecommunication can pass through this region or be reflected. The ionization of...
Thermo-mechanical properties of V-5Cr-5Ti alloy: 3D molecular dynamics simulation
July 2020
This paper presents the results of the study of 3D molecular dynamics simulation to investigate the thermomechanical properties of the V-5Cr-5Ti ternary alloy. The main purpose of this work is to evaluate the quality of the Finnis-Sinclair potential for V-rich V-Cr-Ti random alloys with a body-centered-cubic (bcc) structure. The results demonstrated that the elastic constants of the V-5Cr-5Ti alloy are close to the...
Interpretation of aeromagnetic data over some parts of Sokoto Basin, Nigeria, using source parameter imaging and 3D Euler deconvolution methods
June 2020
This investigation is aimed at determining depth to the bottom of magnetic source and to reveal some certain geological features across Sokoto basin using source parameter imaging and 3D Euler deconvolution techniques. The investigation employed fifteen number aeromagnetic sheets covering longitude 4°30'E - 6°00E and latitude 11°00'N - 13°30'N. The total magnetic intensity of the area was...
Determination and establishment of empirical relationship between magnetic susceptibility and mechanical properties of typical basement rocks in Southwestern Nigeria
June 2020
Magnetic susceptibility and mechanical properties of rocks in a typical basement complex Southwestern Nigeria were correlated with the aim of establishing empirical equations relating the two parameters and evaluate the parameters as related to its competency in hosting civil structures. A total of thirty rock samples were taken across the geology of the area and subjected to mechanical properties determinations....
Influence of natural additives and crushed bricks on the physical and mechanical properties of repair and restoration mortars
May 2020
This study aims to evaluate the influence of different additives, including natural additives such as olive oil and eggs, on repair and restoration mortars. This work enables us to verify the effects of these natural components and their impact on the physical and mechanical characteristics of various types of repair mortars. Four mortar formulations were developed and analysed: Two jointing mortars, including the...
Preparation of thermal neutron absorber based B4C/TiO2/polyaniline nanocomposite
April 2020
B4C nanoparticles (NPs) have been integrated at that point veiled by TiO2 NPs lastly composited by utilizing polyaniline (PANI), (B4C/TiO2/PANI). Shields of thermal neutrons by B4C/TiO2/PANI have been considered, B4C/TiO2/PANI nanocomposite was described by FTIR spectroscopy, and nanometer size, morphology, and structures of tests were estimated by SEM and XRD. The electric property was additionally performed by the...
Solar events and seasonal variation of foF2 at Korhogo station from 1992 to 2002
March 2020
In this paper we report the effect of solar events (CMEs and solar winds) on foF2 diurnal profiles at Korhogo Station (Long 8.427° W; Lat: 9.336° N; dip: -1.88°) from 1992 to 2002. We reviewed on seasons and all the four geomagnetic activity classes (Quiet activity, recurrent activity, Shock activity, and Fluctuating activity). The results show that (1) Coronal Mass Ejections (CMEs) and high-speed solar...
Performance assessment of cross polarization models at millimetre wavelengths along Earth–Space path in Nigeria
March 2020
Rain-induced depolarization impairments have been a constraint on the effective use of satellite communication systems at millimetre wave band especially in the tropical regions like Nigeria. This region often experiences high and varying degree of rainfall intensity accompanied with large raindrops due to distortion of raindrops when dual orthogonal polarization is employed to double the channel capacity without...
Estimation of swelling potential of Enugu Shale using cost effective methods
February 2020
The behavior of swelling soils is mainly governed by its mineralogical composition as well as its environmental factors and stress history. Enugu Shale is one of these shales that assessment of its soil swelling potential cannot only be based on its mineralogical composition alone. The identification of its clay mineral types is basic to understand the roles of other factors of swelling in the soils. The results of...
Assessment of groundwater quality condition at Tarauni dumpsite area, Kano Northwestern Nigeria
January 2020
2-D resistivity imaging and physicochemical analysis were used to investigate the intrusion of leachates on groundwater quality around a dumpsite in Tarauni Local Government Area of Kano State, Nigeria. Four (4) imaging traverse lines were established and Wenner configuration was adopted using an electrode spacing from 5.0, 10.0, 15.0 to 60.0 m. Data collected from the imaging were inverted using AGI EarthImager 2D...
On the slow-time geomagnetic field modulation of cosmic rays
November 2019
In this work, monthly means of cosmic ray count rates from two mid latitude (Hermanus and Rome), and two higher latitude (Inuvik and Oulu) neutron monitors (NM) were employed and their variability was compared with geomagnetic stations that are in close proximity to the NMs. The data spans 1966 to 2008 and covers four solar cycles. The difference (CRdiff) between the mean count rate of all days and the mean of the five...
Assessment of heavy metal pollution in marine sediments receiving produced water, Delta State, Nigeria
October 2019
Every aspect of oil and gas operations poses significant negative impacts on the environment in varying levels, these environmental impacts have economic and public health consequences on the indigenes of the operation locality. Produced water discharge is one of such aspects of the upstream oil and gas operation whose potential for environmental degradation has necessitated both local and international regulations for...
Comparative study of caffeine content in beans and leaves of Coffea arabica using UV/Vis spectrophotometer
October 2019
Caffeine is one of the compounds found in coffee beans and other parts of coffee plant. However, the relative caffeine content in different coffee plant parts is least researched. Therefore, this study was designed to determine the content of caffeine in green coffee leaves and beans. In this work, we report content of caffeine in green coffee beans and leaves of Coffea arabica using UV/Vis spectrophotometer with...
The magnetic moment of elementary particles is studied by space vector and space curvature
September 2019
This paper reaffirms the basic agreement of the material space theory: (1) Space is a physical existence; (2) "Force" is the action to space, and "force" is equal to the reciprocal value of "time"; in the absence of special description, "force" is the reciprocal of time; (3) There is a steady velocity field in three-dimensional space, whose intensity is the speed of light C; (4)...
Seasonal analyses of solar radiation on flat ground for different stat of sky: Case of Nouakchott, Mauritania
August 2019
This paper proposes a method to evaluate solar energy on flat ground for different state of sky (clear sky, moderately covered sky and covered sky). Four semi-empirical models (Link Cloudiness Factor (LCF), Perrin-Brichambaut (PB), Ghouard (GD), Bird Hulstrom (BH)) have been considered to predict solar radiation. An influence analysis of the seasonal variation on the quality of solar energy potential was carried out. In...
Integrated geophysical approach for imaging sedimentary outcrop at Northwestern Peninsular Malaysia
August 2019
An outcrop is a visible exposure of bedrock or ancient superficial deposits on the surface of the Earth. In recent years, outcrop studies have become very important to understand the geology of the earth. The lack of studies on outcrops depends on the interpretations and observations at the surface of the earth only. Besides that, lack of specific physical value for the type of materials can cause misinterpretation of...
Gravitational waves as a test of general relativity
August 2019
General relativity has been very successful as a model for space and gravity. It is supported from a range of experimental results. With the advent of the detection of gravitational waves, another platform exists to trumpet its triumph. The merger of black holes has provided evidence in support of the theory of Einstein. Furthermore, the one neutron star merger so far detected provides much more information because of...
Mineralogical and major oxide characterization of Panyam clays, North - Central Nigeria
July 2019
Clay minerals are form over long periods of time, through weathering as a result of gradual chemical breakdown of rocks rich in feldspar. The extent of weathering is determined by many factors. Most common constituent mineral of clays is often one of the members of the mica mineral group. They include illite, sericite, muscovite, and biotite. Others are kaolinite, smectite, mixed-layer clays and chlorite. This paper...
A framework of 5G networks as the foundation for IoTs technology for improved future network
June 2019
The quest for improved communications among objects interconnected in a network has long been awaited. The current fourth generation network (4G) does not enable the range of services the future require, as the fifth-generation network (5G) will be faster and more flexible. The 5G networks and Internet of Things technology seem to be the reality that best describes the basic principles of the future generation mobile...
Designing off-grid hybrid energy supply with photovoltaics in Senegal
June 2019
In Africa, electrification of rural areas are low and off-grid power supply is needed. Often diesel generators are used to provide local electricity supply. However, the tremendous decrease in the costs of photovoltaics provides an attractive option to substitute existing diesel generation or to build up a new electricity supply in those locations, lowering power costs and environmental impact. Photovoltaics (PV) hybrid...
Application of density matrix renormalization group to one-dimensional Hubbard model to study strongly correlated electrons system
June 2019
In this work, we applied density matrix renormalization group to one-dimensional Hubbard model at five numbers of sweep to solve strongly correlated interacting electrons system, starting from two electrons on two sites up to ten electrons on ten sites at half filling. The results that emerged from the present study is in agreement with that of exact diagonalization, variational and Lanczos solution at the varying...
Multivariate statistical assessment and spatial distribution of groundwater contamination in Neke and its environs, South-Eastern Nigeria
May 2019
Groundwater quality in Neke area of southeastern Nigeria was investigated applying multivariate statistical analyses using Statgraphics centurion XVII, ArcGIS 10.2.2 and Surfer 10 software on hydrochemical and bacteriological data from 25 groundwater samples over land cover of about 1283 km2 , in order to unravel the factors influencing ground water quality. From the correlation analysis, Ca2+, Mg2+, K+, and SO42-...
Magneto-Stark effect on exciton in parabolic bandGaAs/〖Ga〗_(0.7) 〖Al〗_(0.3) As quantum well heterostructure
May 2019
The effect of applied crossed electric and magnetic fields on the heterostructure semiconductor is used in the scientific investigation on electronic and optical exciton properties. The aim of this work is to study the magneto-Stark effect for confined excitons in single GaAs-〖Ga〗_(0.7) 〖Al〗_(0.3) As QWs. The magnetic field B is taken as perpendicular to the z-growth direction of the heterostructure, whereas the...
Estimation of sedimentary thickness using spectral analysis of aeromagnetic data over Otukpo and Ejekwe areas of the lower Benue Trough, Nigeria
April 2019
The aeromagnetic data of Otukpo (sheet 270) and Ejekwe (sheet 289) areas of the lower Benue Trough of Nigeria were interpreted quantitatively. The quantitative interpretation employed spectral analysis technique with the aim of locating specific basement depths to buried magnetic source rocks in the study area. First order polynomial fitting was adopted for regional-residual separation of the total magnetic intensity...
A study on the effects of solar wind and interplanetary magnetic field on geomagnetic H-component during geomagnetic storms
April 2019
During geomagnetic storms, the geomagnetic H component is depressed which is preceded by a sudden storm commencement (SSC) or not and this is categorized as sudden or gradual storms. Using the method of cross correlation analysis, we have studied the associations of geomagnetic H components at four low latitude stations at longitudinal separations of 145° - 215° with solar wind density and interplanetary...
Magnetic source basement depth determination of Ikogosi Warm Water Spring South Western Nigeria and the environ using aeromagnetic data
March 2019
Structural features of Ikogosi Warm Spring and its environs have been delineated using qualitative and quantitative interpretation methods. Euler-Deconvolution and local wave number methods were adopted for quantitative and qualitative interpretation of aeromagnetic data sheet 243 by Geological Survey Agency of Nigeria (GSN) in 2008, respectively. Euler solution revealed depth range of -2.98 to -290 m to the magnetic...
Structural, magnetic and transport properties of samarium (Sm) doped Cu-Zn ferrites
March 2019
The present work is focused on investigating the effect of rare earth ion on structural, magnetic and transport properties of (Cu0.5Zn0.5Fe2-x)SmxO4[x = 0.00, 0.05 and 0.10] ferrites which were prepared by solid state reaction technique at 1100°C for 3 h. The X-ray diffraction analysis revealed that rare earth free sample shows formulation of single phase cubic spinel structure with no extra peak whereas Sm...
Thermospheric neutral winds over Abuja, Nigeria
January 2019
We present nighttime variation of thermospheric winds estimated from the Fabry-Perot interferometer (FPI) which was recently deployed at Abuja in Nigeria. These results apply to the thermosphere region around 250 km and were obtained during the period of weak solar activity with solar flux values generally below 70 s.f.u. The results presented cover three months, from October 2017 to December 2017. The high geomagnetic...
Spectral analysis and source parameter imaging of aeromagnetic data of Lafia and Akiri Areas, Middle Benue Trough, Nigeria
January 2019
This study aimed to estimate the depth of magnetic source bodies in Lafia and Akiri areas which fall within the middle Benue trough, Nigeria. Aeromagnetic data were used and spectral analysis and source parameter imaging were used for the quantitative interpretation of the data. The total magnetic intensity (TMI) contour map obtained from gridding of the data ranging from -39.5 to 100.0 nT was separated into regional...
Assessment of outdoor radiation levels and radiological health hazards in Emene Industrial Layout of Enugu State, Nigeria
December 2018
A study to assess the outdoor Background Ionizing Radiation (BIR) levels in Emene Industrial Layout of Enugu State, Nigeria has been conducted. An in-situ measurement of BIR exposure rate in mRh-1 for 30 locations was done using a well calibrated portable GQ GMC-320 PLUS nuclear radiation detector at an elevation of 1.0 m above ground level with a geographical positioning system (GPS) for geographical location. The...
Magnetosphere convection electric field (MCEF) time variation from 1964 to 2009: Investigation on the signatures of the geoeffectiveness coronal mass ejections
December 2018
The signatures of the geoeffectiveness solar disturbed events on the Magnetosphere Convection Electric Field (MCEF) universal time variation from 1964 to 2009 are investigated. Here, attention is focused our on the periods concerned by the whole shock activity and by the different types of the geoeffectiveness Coronal Mass Ejections (CMEs) which are one-day-shock, two-days-shock and three-days-shock. The investigation...
Noise exposure levels and health implications on daily road side petty traders at some major roundabouts in Ibadan, Nigeria
December 2018
The level of noise exposure to daily road side traders at five major roundabouts in Ibadan metropolis was assessed. Noise measurements were made using a precision multi-function sound level meter. Measurements were made at three different periods of the day; morning (7:30 to 11:30 a.m.), afternoon (12:00 to 3:00 p.m.) and evening (4:00 to 5.00 p.m.) for a consecutive period of ten days. The highest mean maximum noise...
Mathematical modeling and numerical simulation for the formation process of nanofilms
November 2018
This study applied a generalized model to describe and optimize the formation process of nanofilms from their polymeric solutions. Through this model, one can optimize the concentration of the solvent in the polymeric solution, the appropriate geometric dimensions as well as the nanofilm formation speed. A comparison of this model with experimental data has revealed some similarities and differences in the...
Deriving an expression for electron-reflection-coefficient at metal-semiconductor-interface of dye-sensitized solar cells
October 2018
This work aims to derive an expression to describe the reflection coefficient of an escape electron from metal-semiconductor interface of DSSC. The derivation was obtained by analytically solving electron diffusion equation with assumptions of steady state DSSC and negligible current flow at the outer most part of the film. The derived corrected Richardson-Dushman equation including a reflection of electron wave...
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