Improvement of the homotopy perturbation method to nonlinear problems
February 2018
This paper proposes an effective improvement of the homotopy perturbation method (HPM) by using Jacobi and He's polynomials to solve some nonlinear ordinary differential equations. With this method, the source terms of ordinary differential equations can be expanded in series of shifted Jacobi polynomials. Numerical results are given in this paper to illustrate the reliability of this method with nonlinear ordinary...
Green synthesis of silver monometallic and copper-silver bimetallic nanoparticles using Kigelia africana fruit extract and evaluation of their antimicrobial activities
February 2018
Aqueous extract of Kigelia africana fruits have been utilized in the syntheses of silver nanoparticles (AgNPs) and copper-silver bimetallic nanoparticles (Ag-CuNPs). The synthesized nanoparticles have been characterized using UV-vis, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy/energy dispersive X-ray analysis (SEM/EDX), x-ray diffration (XRD) and transmission electron microscopy (TEM)....
High-latitude thermospheric zonal winds during low solar activity period
January 2018
Changes resulting from the cyclical nature of the sun’s energy output result to variations in thermosphere-ionosphere system parameters. The prolonged low solar activity period of solar cycle 23 provides an opportunity to study the thermosphere-ionosphere system parameters when the sun was at its ground state. The CHAMP satellite has provided wind data that can be used for investigation of neutral thermospheric...
Study of the performance of a system for dry cleaning dust deposited on the surface of solar photovoltaic panels
January 2018
This study was carried out at the International Center for Training and Research in Solar Energy (CIFRES) and its main purpose was to study the performance of a solar module cleaning system. To handle this work, a measuring platform consisting of two polycrystalline (pc-Si) PV modules was designed. The modules were connected to a waterless cleaning system on the surface of the solar panels. The platform also contained a...
A comparative study of maximum power point tracker approaches based on artificial neural network and fuzzy controllers
January 2018
The performances of a photovoltaic (PV) module connected to a load through a conversion stage (chopper, inverter) are linked to the average electricity output including the delivered power. Nevertheless, the efficiency depends on atmospheric parameters as temperature, irradiance, and wind speed. To make electrical power available, Maximum Power Point Trackers (MPPT) algorithms are developed to keep up the PV module at...
Spectroscopy and chemical analysis of natural dye from Sorghum bicolour
December 2017
Many plants produce very attractive flowers, leaves and fruits. Colour pigments that are derived from nature are believed to be environmentally friendly because of their non-toxic, non-carcinogenic and biodegradable nature. In this project, colour pigment from ethanol extract of Sorghum bicolour was investigated using three different spectroscopic techniques (UV-Vis, FT-IR and GC/MS). The effects of dyeing parameters;...
Microstructure and mechanical properties correlation for the steel: A comparative methodology of educational research for physics and mechanical engineering trainings
December 2017
An academic methodology based for experimental evaluation of materials treatment is presented. The study is centered in an educational research emphasis about microstructure evaluation and heat treatments in steels samples machined according to ASTM E8 specifications. The uses of metallographic techniques and hardness/tensile tests for analyzing experimental variations due to structural changes are included. Different...
Intersection of lineaments for groundwater prospect analysis using satellite remotely sensed and aeromagnetic dataset around Ibodi, Southwestern Nigeria
December 2017
This research investigates groundwater potential of Ibodi and its environs using satellite imagery remotely sensed and aeromagnetic dataset. This hydrogeological investigation involved the extraction of lineaments from Landsat Thematic Mapper (TM) satellite imagery and aeromagnetic lineament of the area. The processed image revealed lineaments trending in approximately NE-SW direction; also, Landsat and aeromagnetic...
Variability of quiet-time diurnal amplitude and phase of cosmic ray count rates in the mid- and high latitudes
November 2017
Studies have been done on the variability of cosmic rays flux during solar quiet days at mid and high latitudes. By using the 5 quietest days for each month, the monthly mean diurnal variation of cosmic ray anisotropy have been derived for the period 1981 to 2007, which covers part of cycles 21, 22 and 23. These quiet days are days during which the sun is relatively magnetically quiet, leading to less anisotropic...
Investigation on equinoctial asymmetry observed in Niamey Station Center for Orbit Determination in Europe Total Electron Content (CODG TEC) variation during ~ solar cycle 23
November 2017
This is an investigation of equinoctial asymmetry in Total electron content (TEC) variability at Niamey (Latitude: 13° 30' 49.18" N, Longitude: 2° 06' 35.28" E) using the Global Ionospheric Maps model constructed by the Center for Orbit Determination in Europe (CODG model) during solar cycle 23, that is, from year 1999 to year 2009. Niamey Center for Orbit Determination in Europe...
Evaluation of the impact of partial shading and its transmittance on the performance of crystalline silicon photovoltaic modules
November 2017
This paper presents on the one hand, an evaluation of the impact of partial shading on the performance parameters of two photovoltaic modules respectively in poly and mono. The current-voltage characteristic (I-V), the short-circuit current (Icc), the open-circuit voltage (Vco) and the maximum power (Pmax) were studied. In this work, the measurements were carried out under the standard conditions (STC) in order to make...
Solar wind plasma associated with Dst < -50 nT during solar cycle 24
November 2017
This study analyzed the correlative study between the peak intensity of the geomagnetic storm, interplanetary magnetic field (IMF) and the peak value of various plasma parameters during the solar cycle 24. This study has been performed using hourly values of the geomagnetic storm time (Dst) < -50 nT for the period 2008 to 2016. 173 events of disturbance storm time with solar wind velocity ≥ 350 km/s were selected...
Estimation of sedimentary thickness using spectral analysis of aeromagnetic data over Abakaliki and Ugep areas of the Lower Benue Trough, Nigeria
November 2017
Aeromagnetic data over Abakaliki and Ugep areas of the lower Benue Trough were interpreted to determine the depth to magnetic source rocks of the area. The study area covered latitudes 5° 30' and 6° 30'N and longitudes 8° 00' and 8° 30'E with an estimated total area of about 6000 km2. Quantitative interpretation was carried out using spectral analysis method to compute for depth to...
Radioactivity in building materials in Saudi Arabia: An overview of experimental method and Monte Carlo N-Particle (MCNP) calculation
October 2017
The aims of this work were clearly to assess the norms of radiation protection for building residents against natural radioactivity. This was done through measurement of natural radioactivity in building materials using gamma ray spectrometer. The annual effective dose (HR) linked to natural radioactivity was computed to estimate the radiation hazard in building materials. Obtained concentrations of these natural...
A study of semi-annual variation of residual geomagnetic field and its association with solar and geomagnetic activity
October 2017
The semi-annual variation of the residual H and Z components of geomagnetic field was studied by analyzing magnetograms with sixty-one years data. Mean monthly residual H- and Z-component field (Hdiff and Zdiff) variations were computed using appropriate technique. Semi-annual variation exhibited Hdiff peaks in the equinoxes, which for low latitudes, was higher during March/April than in September/October. In the mid...
Models for calculating monthly average solar radiation from air temperature in Swaziland
October 2017
Solar radiation is an important energy source for mankind. Accurate data of solar radiation levels for a particular location is vital for optimum operation of solar energy transducers such as photovoltaic cells and solar thermal collectors. In this work, it is shown a linear relationship exist between monthly average temperatures and solar radiation in Swaziland. The correlation has been utilized to develop two...
Assessment of natural radionuclide levels in some Nigerian made poultry feedstuff
October 2017
This study investigated the radionuclide contents of naturally occurring radionuclides. Ten samples of some Nigerian made poultry feedstuff and supplements were collected and analysed using NaI(Tl) gamma(ð›¾)-ray spectroscopy for an accumulated time of about 29000 s. The results revealed that activity concentration of primordial radionuclides 40K, 226Ra, and 232Th for the samples ranged from 43.6 to 196.8 Bq/kg, 5.0 to...
Analysis of organochlorine and organophosphorus pesticide residues in blood samples of sheep and rabbits from villages of Jimeta-Yola, Adamawa State, Nigeria
October 2017
Blood samples of sheep and rabbits from five different villages of Jimeta-Yola, Adamawa State, Nigeria were collected for determination of organochlorine and organophosphorus pesticide residues. Preparation of blood samples was carried out using standard procedure of QuEChERS method of extraction. The concentrations of all the pesticides in blood samples of sheep and rabbits were determined using Gas...
Spectral depth analysis for determining the depth to basement of magnetic source rocks over Nkalagu and Igumale areas of the Lower Benue Trough, Nigeria
October 2017
Structural interpretation of aeromagnetic data over Nkalagu-Igumale area of the Lower Benue Trough of Nigeria was carried out to determine the depth to magnetic basement and delineate the basement morphology and the structural features associated with the basin and their trends. The aeromagnetic data were subjected to series of computer based image and data enhancement techniques before spectral analysis. Results of the...
Optimization of electrical production of a hybrid system (solar, diesel and storage) pilot using HOMER in Biret, Southern Coast of Mauritania
September 2017
The purpose of this work is to study the optimization of an hybrid system of electricity production (solar-diesel with storage) of Biret (Mauritania) using the Hybrid Optimization Model for Electric Renewables (HOMER) software. Indeed, it shows that the context and behavior of the chosen system is optimal. HOMER is used to present simulations in the most economical way. It is important to note that the application of...
Studies on equalities and inequalities of heat, work and ratio of work to temperature
September 2017
This research investigates relationships between resistances with heat and work. It is completely proven that the ratio of work to temperature for the realistic process is no less than that for the reversible process. The equalities and inequalities on the heat, work and ratio of work to temperature could be applied to the gravitational field and chemical reactions. The relationships between path functions and state...
Application of Ojih-Okeke modified empirical coronal mass ejection arrival (ECA) model in predicting the arrival time of coronal mass ejections (CMEs)
August 2017
Predicting the arrival time of Coronal Mass Ejections (CMEs) with a lower value of average error of the difference between the predicted and the observed transit time is very crucial in space weather forecast. A modified Empirical Coronal Mass Ejection Arrival (ECA) model was proposed, namely, Ojih-Okeke modified ECA model to predict the transit time of twenty eight fast CMEs from the sun to the earth. This is the first...
Problems with p6Li plasma in a fusion reactor
August 2017
Problems of using proton-Lithium-6 (p6Li) fuel are energy losses that occur in a fusion reactor. Investigating the energy balance equation in this fuel is significant. The p6Li reaction is termed aneutronic, as it produces relatively few neutrons and requires none for breeding. The energy from the charged reaction products can be directly converted to electrical power at a much higher efficiency than Deuterium-tritium...
Influence of solar and geomagnetic activity on climate change in Nigeria
August 2017
This study investigates the possible effects of solar and geomagnetic activity on climatic parameters in Nigeria. Data of sunspot number and geomagnetic aa index from 1950 – 2012 and 1950 – 2010 were used as solar indices respectively. Monthly mean daily rainfall, minimum and maximum temperature data from 1950 – 2012 for 15 stations were used as climatic parameters. Descriptive and bivariate analyses...
Simulation of precipitation variations in Iran using Kriging interpolation methods
August 2017
This study estimated spatial variability of precipitation in the monthly and annual scales in Iran for the period of 1975 to 2014 in 140 stations using kriging interpolation methods. In precipitation variability analysis three procedures were used: Mann-Kendall test, Sen's slope estimator and spatial trend patterns. Results show that there are both increasing and decreasing trends in monthly precipitation in Iran....
Variability of maximum temperature and its decadal anomaly over Nigeria: Possible connection with Solar and geomagnetic activity
July 2017
This work investigates the variability of maximum temperature and its decadal anomaly in Nigeria and the possible role of Solar and geomagnetic activity. Descriptive, bivariate and spectral analyses, as well as Mann-Kendall trend test, were employed in analyzing the data used in this study. Temperature anomaly was computed using the base period, 1981 – 2010. Results revealed that seasonally, temperature varies...
Estimation of depth to magnetic source bodies of Nsukka and Udi areas using spectral analysis approach
July 2017
The study was aimed at estimating the depth to magnetic source bodies in Nsukka and Udi areas which falls within the Anambra basin. Aeromagnetic data were used and Spectral Analysis approach was employed in the quantitative interpretation. The total magnetic intensity (TMI) contour map which ranges from -53.1 to 133.7 nanoTesla (nT) was separated into regional and residual contour maps to produce a residual aeromagnetic...
Omnidirectional High Reflectors using 1-D Photonic Crystals
June 2017
Much interest has been paid to omnidirectional dielectric mirrors based on the 1-D dielectric multilayers because these are better than metal mirrors owing to their low optical loss, high reflectivity and high mechanical robustness. In these applications, the required position and width of the reflection band can be obtained by adjusting the layer thickness and refractive indices of the constituent materials. Here, the...
A derivation of the Kerr metric by ellipsoid coordinate transformation
June 2017
Einstein's general relativistic field equation is a nonlinear partial differential equation that lacks an easy way to obtain exact solutions. The most famous of which are Schwarzschild and Kerr's black hole solutions. Kerr metric has astrophysical meaning because most cosmic celestial bodies rotate. Kerr metric is even harder than Schwarzschild metric to be derived directly due to off-diagonal term of metric...
Energy levels and reduced transition probabilities of 18-20F isotopes using USDA and W Hamiltonians
May 2017
Energy levels for (18F, 19F and 20F) isotopes have been studied within the framework of shell model using OXBASH code. In this work, the calculations are based on the Universal Sd-shell Hamiltonian (USDA) and W Hamiltonians for proton and neutron particle orbits in SDPN model space. The calculated energy levels and reduced electric quadrupole transition probabilities B(E2;↓) are in reasonably agreement with...
Investigation of possible cause of gravity anomalies in parts of the Niger Delta Basin, Nigeria
May 2017
Possible cause of gravity anomalies in parts of the Niger Delta Basin, Nigeria was investigated using three methods of gravity data interpretation; Euler-3D deconvolution, source parameter imaging (SPI) and forward and inverse modeling. The estimated depths from the interpretation techniques used show much similarity. Quantitatively, the results obtained from the SPI method showed a minimum to maximum depth of 1264.11...
Determinations of norfloxacin complexes with caffeine, and its optical transition probabilities using UV-Vis spectroscopy
April 2017
The optical transition probabilities and hetero-association of caffeine with norfloxacin were obtained using UV-Vis spectroscopy in aqueous solution at room temperature (295K). The heter-association constant of norfloxacin-caffeine complexes (6.67×103 M-1) was obtained using Benesi-Hildebrand approach by linear curve fitting to the experimental data. In order to characterize the binding system of the compounds,...
Doppler fading communication channel performance simulation
April 2017
Fading is commonly used to describe the properties of the communication channel. Large efforts have been made to describe characteristics of the channel in wireless communication system. The performance of wireless signal propagation in a conventional environment needs Doppler fading channel schemes by assuming a perfect knowledge about the channel frequency response at both the transmitter and the receiver sides. Two...
Application of data mining in telecommunication industry
March 2017
This paper applied a data mining model in sales and marketing department of Telecommunication Industry (TI) in Nigeria. The motivation behind the paper is as a result of competitive challenges facing most TI sales and marketing departments globally such as inability in gaining precise view of targeted data, inability to translate and formulate business question correctly and Problem of addressing data quality. The...
Hydrogeochemical investigation and characterization of shallow groundwater within Ankpa Town, North Central Nigeria
March 2017
Physico-chemical analysis of groundwater samples from Ankpa, north central Nigeria was carried out to investigate the quality of the water for drinking and irrigation purposes. The results revealed water of average low pH, indicating slightly acidic conditions of the water. The water is soft, and it is characterized as Na++K - HCO3 type. It is good for drinking and other domestic uses. Four indices were evaluated from...
Pressure and temperature effects on corona onset voltage in electrostatic precipitators
March 2017
Corona onset voltage is one of the most important factors that determine the charging toxic particle in an industrial application. Electrostatic precipitators (ESP) remove the suspended particle with a gas inlet. This paper developed Peek's formula to estimate the maximum electric field near the discharge wire in corona discharge models, the values of maximum electric field and corona onset voltage near the...
Performance evaluation of law enforcement agency on crime information management using queuing network model
February 2017
One of the greatest challenges facing every society today is crime control and management. It could be as little as pick–pocketing, or human trafficking, or even as deadly as terrorism. As criminal’s perfect ways of avoiding being detected, Law Enforcement Agencies (LEAs) must adopt innovative ways on crime prevention and control. This research applies Queuing Network (QN) model to evaluation the performance...
Effect of Co component in Co-Ag granular thin films on visible-light reflection applied by magnetic field
February 2017
The reflection of visible light (wavelength from 350 to 800 nm) on magnetic granular thin films Cox-Ag1-x with x from 0 to 35 at % was studied. Dependence of reflection (R) is strong on magnetic and percentage of Co in the thin films, R strongly increase in wavelengths 560 and 660 nm. In this paper, some arguments relating to the spin-plasmon phenomenon were used to explain the results. Key words: Granular magnetic...
Partial and total mass attenuation coefficients, effective atomic number and effective electron number of different Maraging steel compositions
January 2017
The total and partial mass attenuation coefficients for different Maraging steel compositions have been determined by using the WinXCom and MCNP5 programs. The effective atomic number, Zeff, and effective electron number, Neff, for the studied steels have been determined via the total mass attenuation coefficients μ/ρ, the total atomic and electronic cross sections (σa and σe) of the investigated...
Energy saving by applying the fuzzy cognitive map control in controlling the temperature and humidity of room
January 2017
This paper investigated the implementing of soft computing methodology of fuzzy cognitive map on controlling parameters of heating, ventilating and air-conditioning systems. In the past few years, many researches have been done on application of different controllers on heating, ventilating and air-conditioning system as a more energy consuming part of the building automation system. Unlike the conventional control...
Calibration and estimation of efficiency of Geiger Muller counter using a standard radioactive source
January 2017
The beta counting system uses a Geiger-Muller (GM) tube to detect the presence of beta contamination present in filter paper samples or in planchet samples. The counting system is enabled with a provision to count the samples at various distances from the detector to the sample position. The efficiency of the counting system is provided by the manufacturer at the time of procurement which is calibrated and...
Multiples in Onshore Niger Delta from 3D prestack seismic data
January 2017
The presence of multiples has been investigated in Onshore Niger Delta using 3D seismic data. The aim of the study was to investigate the characteristics of reflection events beyond 3s two way time on seismic data behind the boundary faults associated with the shadow zone. This involves detailed velocity analysis on semblance plot panel and accounting for moveouts due to reflections away and within the shadow...
Numerical modeling and determination of parameters characteristic of a photovoltaic module LRAER (FST Nouakchott)
December 2016
The main objective of this work is to study, develop and establish an approach through the mathematical model of performance CENERG under the term (MC). This model is used to characterize the parameters of photovoltaic systems in the literature. For this, we have considered the required performance is normally measured in standard test conditions (STC), where an average solar spectrum AM 1.5 is used, sunshine is...
Sandwich panels from cork and polyester in presence of epoxy resin as interfacial adhesive
December 2016
This work presents an experimental study to determine the mechanical properties in bending, tension, compression and shear of a new sandwich material based on natural materials (jute and cork). The sandwich material is made basically of natural materials whose soul is agglomerated cork white (located in Jijel, East of Algeria) and the skins are woven jute with ortho phthalic polyester resin. Agglomerated white cork...
Phasors from the linear algebra perspective applied to RLC circuits
December 2016
Phasors provide a simple way to analyze sinusoidally excited linear circuits. Solutions of those circuits would be undoable otherwise. Besides, measurement units in phasors are a technological resource that powers with precision the observation of the electric power system dynamic state. In the last technological research in electronics, through this units tension phasors and current phasors are obtained in a...
Troubled roads: Application of surface geophysics to highway failures of the sedimentary terrain (Iruekpen-Ifon Road) of Edo State, Nigeria
November 2016
As part of effort to examine the factors responsible for highway failure in the sedimentary terrain, geophysical survey involving Very Low Frequency Electromagnetic (VLF-EM), Schlumberger Vertical Electrical Sounding (VES), and dipole-dipole electrical resistivity techniques were carried out along Iruekpen-Ifon highway. This was aimed at using surface geophysics to characterize and identify the factors responsible the...
Thermo-economic study of hybrid cooling tower systems
November 2016
In this paper, the effects of ambient temperature and relative humidity on performance of wet, dry, and two combined cooling systems are studied for a typical 250 MW power plant in Hamedan, Iran. Although there have been many works in background of effects of different parameters on performance of cooling towers, there is no detail analysis about different alternatives of hybrid cooling systems due to the water...
Some fish species in offshore Fukushima, Japan have the ability to accumulate a specific nuclide (radioisotope)
November 2016
The Tokyo Electric Power Company's, Fukushima Dai-ichi nuclear power plant in Fukushima-Ken (Fukushima Prefecture), Japan, was destroyed in March 2011 by a massive magnitude 9 earthquake (centred offshore to the northeast of Honshu Island) and by the subsequent historic Tsunami of March 11, 2011. Because of the nuclear meltdown, hydrogen-explosion damage to the buildings that housed the reactors, and the...
Investigation of self-association, optical transition probability and hetero-association with chlorogenic acid of nicotinamide using UV-Vis spectroscopy
November 2016
The self-association, optical transition probabilities, and hetero-association with chlorogenic acid of nicotinamide were obtained from UV-Vis spectroscopy in aqueous solution at room temperature (293K). The dimerization constant of nicotinamide ( ) was obtained using dimer model by nonlinear curve fitting technique. The hetero-association constant in the system of molecules of nicotinamide with chlorogenic acid...
Baryte mineral exploration in parts of the lower Benue Trough, Nigeria
November 2016
The use of DC electrical method in baryte mineral exploration has been investigated in Buruku northeast of Markurdi, Nigeria. The objective of the study was to investigate the suitability and potential of electrical resistivity tomography (ERT) combined with vertical electrical sounding (VES) surveys in baryte mineral exploration over known deposits. Results show that the interpreted layer resistivities correlate with...
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