Egbin power station generator availability and unit performance studies
February 2015
This paper presents investigation on availability carried out on six steam unit generators in Egbin Thermal-Power Station in Nigeria. The availability investigation covers from 2005 to 2011 and was done through an exhaustive collection of data from samples of operating facilities in the power station. Data was collected from plant user maintenance log, operation records and manufacturers’ data were also sources of...
Kinetics study of copolymerization of 2-anilinoethanol onto chitosan by ammonium peroxydisulfate as a initiator
February 2015
Graft copolymerization of 2-anilinoethanol (2AE) onto chitosan (Chit-g-P2AE) was carried out by using ammonium peroxydisulfate (APS) as a long initiator under nitrogen atmosphere. Evidence of grafting was confirmed by comparison of FTIR spectrum of chitosan and the grafted copolymer. The grafting kinetics in the different conditions was studied as well. The effects of concentration of APS, 2AE, reaction time and...
The modified simple equation method for solving nonlinear diffusive predator-prey system and Bogoyavlenskii equations
February 2015
The modified simple equation method (The modified SEM) is employed to find the exact traveling wave solutions involving parameters for two nonlinear evolution equations, namely, the diffusive predator-prey system and the Bogoyavlenskii equations. When these parameters are taken to be special values, the solitary wave solutions are derived from the exact traveling wave solutions. It is shown that the modified SEM...
Financial planning for the preventive maintenance of the power distribution systems’ critical components using the reliability-centered approach
February 2015
Among different maintenance strategies that exist for power distribution systems, the Reliability-Centered Maintenance (RCM) strategy attempts to introduce a structured framework for planning maintenance programs by relying on network reliability studies and cost/benefit considerations. For the implementation of the RCM strategy, the electricity distribution companies try to optimally utilize the existing financial...
Relation between classical mechanics and physics of condensed medium
February 2015
An equilibrium system of potentially interacting material points in a nonhomogeneous field is studied by numerical simulations, as well as criteria which are needed in order to switch from the quantified model to the thermodynamic one. This paper studies the system passing a potential barrier and factors which affect the change of the system’s internal energy. These factors include width of the barrier, number of...
Photoluminescence from GaAs nanostructures
February 2015
The confinement properties of semiconductor nanostructures have promising potential in technological application. The main objective of this study is to describe the dependence of Photoluminescence (PL) intensity on different parameters like temperature, excitation wavelength, time and photon energy of GaAs quantum dots (QDs). The model equations are numerically analyzed and simulated with matlab and FORTRAN...
Recent astronomical tests of general relativity
January 2015
This history of experimentation relevant to general relativity covers the time post-1928. Classes of investigation are the weak equivalence principle (equivalence of inertial and gravitational mass and gravitational redshift), orbital precession of a body in gravitational fields (the relativistic perihelion advance of the planets, the relativistic periastron advance of binary pulsars, geodetic precession and...
On the hydrogenation-dehydrogenation of graphene-layer-nanostructures: Relevance to the hydrogen on-board storage problem
January 2015
Herein, results of thermodynamic analysis of some theoretical and experimental [thermal desorption (TDS), scanning tunneling microscopy (STM), scanning tunneling spectroscopy (STS), high-resolution electron energy loss spectroscopy/low-energy electron diffraction (HREELS/LEED), photoelectron spectroscopy (PES), angle-resolved photoemission spectroscopy (ARPES), Raman spectroscopy and others] data on...
Correlation between milling time, particle size for stabilizing rheological parameters of clay suspensions in ceramic tiles manufacture
January 2015
Several parameters governed the rheological properties as well as the nature of the constituents, to the process of implementation. One of the major solution is to master the milling time which is responsible for the fineness of the grains, which in turn, conditioned the correct handling of the sintering mechanism, and allows highlight of the correlation between the size of the powders and the rheological properties....
Characterization of porcelain tableware formulation containing bentonite clay
January 2015
Aluminosilicate are often produced from kaolin with a kaolin bond in the formulation intended to increase the thermal strength of the product. Because kaolin formulations do not sinter well, investigation of methods for increasing the density of kaolin is highly relevant. The density can be increased by increasing the degree of dispersion. An additive which improves sinterability would be especially effective. Bentonite...
A theory of the relativistic fermionic spinrevorbital
January 2015
The Little Rules and Effect describe the cause of phenomena of physical and chemical transformations on the basis of spin antisymmetry and the consequent magnetism of the most fundamental elements of leptons and quarks and in particular electrons, protons and neutrons causing orbital motions and mutual revolutionary motions (spinrevorbital) to determine the structure and the dynamics of nucleons, nuclei, atoms,...
UV Absorption and dynamic mechanical analysis of polyethylene films
December 2014
Photooxidative processes that lead to chain scission and chain linking in polymers play an important role in polymer degradation. These processes are induced by both ultraviolet (UV) and visible light absorption. The capability of these radiations to be absorbed depends on the existence of chromophores in the polymeric material. Assessment of photodegradation data obtained from a polymer material processed in a...
Computational calculation of the electronic and magnetic properties of 1x1-MN/GaN (M = V, Cr and Mn) multilayers
December 2014
We employed density functional theory (DFT) in order to study the electronic and magnetic properties of 1x1-MN/GaN (M = V, Cr, and Mn) multilayers, in the wurtzite-type hexagonal structure. The calculations were carried out using a method based on full-potential linearized augmented plane waves (FP-LAPW), employed exactly as implemented in Wien2k code. For the description of the electron-electron interaction,...
Application of soft computing techniques for multi source deregulated power system
December 2014
In this paper, an interconnected power system is proposed for Automatic Generation Control (AGC) in restructured power environment. The customized AGC scheme is projected in deregulated environment for multi-source combination of hydro, reheat thermal and gas generating units in entire area. Proportional integral derivative controller is offered for AGC scheme and the gains are optimised through soft computing...
Primordial radionuclides in potable water from former tin-mining areas with elevated activity
December 2014
The activity concentrations of the primordial radionuclides in potable water from 2 former mining areas (Bisichi and Bukuru) in Jos, Plateau state in Nigeria have been studied. The activities were determined by a non-destructive analysis using a computerized gamma ray spectrometry system with high purity germanium (HPGe). The results show the average activity concentrations for 226Ra, 232Th and 40K for Bukuru and...
Theoretical studies of CO converted to CH3OH by ZINDO/1-DFT methods
December 2014
The aim of this study is to simulate co-catalysts of titanium nitride nanotubes (TiN-NTs) with Cu nano-particles for converting carbon monoxide (CO) and water into methanol. This method may provide a new way to reduce carbon-monoxide levels in the atmosphere rising due to our planet's heavy use of fossil fuels as well as to produce alternative fuels. Using TiN-NTs has shown the efficiency to remove CO from the...
Construction of some new exact structures for the nonlinear lattice equation
December 2014
In the present work we examine a generalized coth and csch functions method to construct new exact travelling solutions to the nonlinear lattice equation. The technique of the homogeneous balance method is used to handle the appropriated solutions. Some exact solutions obtained are new. Key words: Nonlinear lattice, travelling wave solutions.
Flat gravity based on Hubble’s law which expanded Newtonian gravity
November 2014
Hubble’s law, formulated by Edwin Hubble and Milton Humason in 1929, tells us that space is expanding. However, over short distances, flat gravity caused by the expanding universe is described by the inverse square law of Newtonian gravity. This leads to heretofore unsolved gravity anomalies, such as the pioneer anomaly, which involves an abnormal slowdown relative to the Sun of the Pioneer spacecraft and the...
Measurement, prediction and modeling the impact of vibration as the possibility of protection cultural heritage objects
November 2014
This article describes the possibility of using prognostic equations and the theory of fuzzy logic to predict the intensity of vibrations resulting from the use of construction machinery and heavy traffic. Vibrations from construction machinery can be particularly dangerous if they affect heritage buildings. By analyzing the measured results of vibrations at various facilities, we found that using the theory of fuzzy...
Modifying the chaotic behavior in the quadrupole wiggler free-electron laser using ion-channel guiding
November 2014
The principles of free-electron laser (FEL) are explained. The motion of an individual electron in a FEL in a field configuration consisting of a quadrupole wiggler magnetic field is investigated. The general formulation of the dynamical problem is given. The Hamiltonian and Hamilton's equations of motion are derived. The problem of integrability and the Hamiltonian chaos is discussed. Upon plotting the...
Analytical investigation of convective heat transfer of a longitudinal fin with temperature-dependent thermal conductivity, heat transfer coefficient and heat generation
November 2014
In this article, the heat transfer through a longitudinal fin is studied. The heat transfer coefficient, thermal conductivity and heat generation are variables and supposed to be temperature-dependent. The temperature distribution in fin with longitudinal rectangular profile was carried out by using the differential transformation method (DTM) which is an analytical solution technique. For validation of the analytical...
Estimation of heavy metals contamination and silicate mineral distributions in suspended sediments of Subansiri River
November 2014
Suspended sediments samples were collected from ten different locations through the Subansiri River to assess heavy metals contamination such as Fe, Al, Ti, Pb, Zn, Cu, Ni, Co, Mn and Cr. The enrichment factor (EF), contamination factor (CF), geo-accumulation index (Igeo) and pollution load index (PLI) were investigated for evaluate metal contamination in the sediments. The relative distribution of major minerals such...
Chemical composition and antioxidant capacity of the leaf extract of Justicia insularis
October 2014
The leaves of Justicia insularis have been generating a lot of interest among the Yoruba people in the Southern Nigeria. They provide useful source of human nutrition and medicinal value. In this study, J. insularis leaves were harvested, processed and analysed to determine their chemical compositions and also to investigate their antioxidant properties. The proximate analysis showed that the sample contained 15.955%...
Detection of energetic particles from plasma focus using Faraday cup and SSNTD (LR-115A)
October 2014
A Mather-type plasma focus device is used in this work which is prefilled with helium at 0.8 Torr. The total ion current density of the plasma stream is measured to be 750 mA/cm2. From time-resolved measurements (Faraday cup), the ion beam energy was distributed with energy ranging from 0.3 to 540 keV. The ion flux density of ion beam is estimated to be 4.47 × 1011 ion/steradian using track etching technique...
Guiding of light with pinholes
October 2014
A new type of light waveguide using linearly aligned pinholes is presented. Results of basic experiments are compared with theoretical estimates calculated using continuous model. This model predicts that the loss per unit length of the light inside this waveguide is proportional to the square root of the spacing between the pinholes. Since this waveguide utilizes no transparent material, it can be used to guide...
On solving the nonlinear Schrödinger-Boussinesq equation and the hyperbolic Schrödinger equation by using the (G'⁄G,1⁄G) -expansion method
October 2014
The propagation of the optical solitons is usually governed by the nonlinear Schrödinger equations. In this article, the two variable(G'⁄G,1⁄G) -expansion method is employed to construct the exact traveling wave solutions with parameters of two nonlinear partial differential equations (PDEs) namely, the (1+1)-dimensional nonlinear Schrödinger-Boussinesq system and the (2+1)-dimensional...
A novel method to develop an automobile assembly line system
October 2014
The assembly line is an important component of the automobile production process. The function of the assembly line is to produce different models of vehicles with minimum work in the process. For better performance, activities on the assembly line should be performed to minimise the process steps and achieve other objectives. This study develops a new dynamic sequencing method to improve activities on the assembly line...
Wet chemical synthesis of Tin Sulfide nanoparticles and its characterization
September 2014
Nanostructured materials have attracted much attention in various fields of science and technology. Tin sulfide (SnS) nanoparticles were successfully synthesized by wet chemical method. The as-prepared tin sulfide nanoparticles were characterized by X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and dielectric studies. The SEM measurements show the aggregates of small...
Effects of land use on river water quality of Awat-Awat Lawas Mangrove Forest Limbang Sarawak Malaysia
September 2014
Water quality and trace elements of river water of Awat-Awat, Sundar and Trusan river from Awat-Awat Lawas Mangrove Forest Limbang (AALMFL) Sarawak, Malaysia were investigated in the current research. This study used the application of Water Quality Index (WQI) and National Water Quality Standards (NWQS) provided by Department of Environment (DOE) Malaysia in evaluating the quality of the river. Fifty two different...
Electrical study of plasticized carboxy methylcellulose based solid polymer electrolyte
September 2014
The electrical conductivity and thermal conductivity of carboxyl methylcellulose doped with oleic acid and plasticized with glycerol have been measured by the electrical impedance spectroscopy method in the temperature range of 303 – 393 K. The composition of glycerol was varied between 0 and 50 wt. % and the samples were prepared via solution casting technique. The highest ionic conductivity at room temperature,...
Strength improvement of a High Performance Fiber Reinforced Concrete (HPFRC) containing local raw materials
September 2014
Improvement of mechanical strength of a High Performance Fiber Reinforced Concrete (HPFRC) containing local raw materials at a cheap rate was investigated in this present work. An experimental study was conducted on different concretes based on dune sand and reinforced by metallic fibers. The concretes studied are formulated based on a Portland Cement (PC), Dune Sand (DS), Dust of Electro-filter (DE), Metallic Fibers...
Comment on "Combined heat and mass transfer by mixed convection magnetohydrodynamic (MHD) flow along a porous plate with chemical reaction in presence of heat source" by Zueco, J. and Ahmed, S., 2010, [Appl. Math. Mech. -Engl. Ed. 31(10), pp. 1217-1230]
September 2014
In this paper, we demonstrate that the previously reported effect of the transverse magnetic field on a steady mixed convective heat and mass transfer flow of an incompressible viscous fluid past an infinite vertical isothermal porous plate considering the induced magnetic field with viscous and magnetic dissipations of energy by Zueco and Ahmed (2010) [Appl. Math. Mech. -Engl. Ed. 31(10), pp. 1217-1230] has some major...
Study of miscibility of liquid mixtures with a critical point: A new experiment for a physical chemistry course
August 2014
This paper describes a new experiment for undergraduate students in physical chemistry. This experiment describes a separation process of liquid-liquid extraction using mixtures with a critical point of miscibility. In this experiment, students will learn how to measure solute concentration, and a new liquid-liquid extraction technique that we called Phase Transition Extraction (PTE). In this experiment, a liquid...
Electrical properties and crystal structure of Y123, Y358 and Y257/Y211 composite bulk superconductors
August 2014
The Y123, Y358 and Y257 bulk superconductors mixed with various ratio of non-superconducting Y211 (Y2BaCuO5) were synthesized by solid state reaction. The physical properties of pellets were investigated by d.c. four-probes measurement. The crystal structure was determined using powder X-ray diffraction and the characteristic peaks were determined using the Rietveld full-profile analysis method. Results showed that the...
Effect of an axial magnetic field on the heat and mass transfer in rotating annulus
August 2014
This study is interested in the effect of an axial magnetic field imposed on incompressible flow of electrically conductive fluid between two horizontal coaxial cylinders. The imposed magnetic field is assumed uniform and constant. The effect of heat generation due to viscous dissipation is also taken into account. The inner and outer cylinders are maintained at different uniform temperatures and concentrations. The...
Some classifications on Kenmotsu manifolds
August 2014
In this paper, we investigate some curvature problems of Kenmotsu manifolds satisfying some certain conditions and we reach some classicifications. We consider -recurrent Kenmotsu manifolds and we show that -recurrent Kenmotsu manifolds are also -Einstein manifolds. Next, we study -Ricci symmetric Kenmotsu manifolds and we find this manifolds are Einstein manifolds too. In addition, we examine locally -symmetric...
Analysis and evaluation of differential inductive transducers for transforming physical parameters into usable output frequency signal
August 2014
This paper presents a novel hybrid oscillating inductive sensor circuit converting deflection oscillations into useful signal and thus being used to support an oscillatory circuit mechanism and management of their resulting oscillation in a real-time implementation. This circuit does not only detects and optimizes the deflections produced in an oscillation in instrumentation electronics, but also provide an improved...
Optimal transformer allocation in electrical distribution using genetic algorithm
July 2014
The optimization of transformers allocation is a major challenge to the operators of electrical energy distribution in several developing countries. In this research, a Generic Algorithm model for the optimization of transformer allocation in electrical distribution networks is developed. The algorithm employed the principles of selection, crossover and mutation to allocate transformers of different capacities to...
Magnetohydrodynamics (MHD) boundary layer stagnation point flow with radiation and chemical reaction towards a heated shrinking porous surface
July 2014
This paper is an investigation of the effects of chemical reaction on two dimensional steady stagnation point flow of an electrically conducting, incompressible, and viscous fluid with radiation towards a heated shrinking porous surface. A chemically reactive species is emitted from the vertical surface into the flow field. The governing partial differential equations are solved using the Newton-Raphson shooting method...
Internuclear forces: Physical and chemical reasons
July 2014
The arguments, obtained in favor of the hypothesis on internuclear interaction of atoms (offered by author in the preceding publication), are presented. It is proposed an interpretation of physical phenomenon Bragg peak, which is discovered 100 years ago but is not understood hitherto. An extremely simple and natural explanation of chemical covalent bond (which unlikely may be considered satisfactory at present) is...
Optical observation of streamer propagation and breakdown in seed based insulating oil under impulse voltages
July 2014
Increasing demand of electricity and high consumption of natural fuel resources has raised countless challenges for the electricity industry. For years, transformers were equipped with mineral oil for better and lasting performance but the recent uncertainty about the future of oil availability is motivating the researchers to find out the “Green Insulating Oils” for transformers. Thus, green insulating oils...
An efficient technique for morphing zero-genus 3D objects
July 2014
In this paper, we present an algorithm to morph a zero-genus mesh model to a topologically equivalent one based on spherical parameterization, as it is the natural parameterization method for this kind of objects. Our algorithm starts by normalizing the two objects to the cube of unity, as a preprocessing step. Then, the two normalized models are parameterized onto a common spherical domain. We reposition the points of...
Measurement and modeling of the effect of gamma irradiation on radiofrequency dielectric properties of bovine kidney tissue
June 2014
The effect of gamma irradiation on the radiofrequency dielectric properties of bovine kidney tissue has been investigated using gamma irradiator (Gs 1000), booton (7200) capacitance meter, signal generator (Lodstars SG-416013) and Dielectric cells Mathematic models of the following dielectric structural parameter, Dielectric spread parameter (), dielectric decrement () and Dielectric relaxation time (), were also...
Research in physical properties of AlxGa1-xAs III-V Arsenide ternary semiconductor alloys
June 2014
General description of III-Arsenide semiconductors is presented and significance of the present work is stressed. The electrical and optical properties of III-Arsenide from binary semiconductors are evaluated using the principle of additivity involving quadratic expressions. The electrical and optical properties studied in this group include refractive index, optical polarizability, absorption coefficient and energy...
Markov chain model for the dynamics of cooking fuel usage: Transition matrix estimation and forecasting
June 2014
Markov chain models are valuable tools for modeling data that vary over time. They are suitable models to use when modeling the transitions of variables between discrete states over time. In this paper, Markov chain model was applied to the data obtained from 300 households living in the headquarters of three Local Governments (Argungu, Arewa, and Augie) of Kebbi State, Nigeria. The data was information concerning the...
Studies on zinc oxide thin films by chemical spray pyrolysis technique
June 2014
Zinc oxide (ZnO) thin films were deposited by chemical spray pyrolysis (CSP) technique using zinc acetate dihydrate solutions on microscopic glass substrates by varying the precursor concentration. The prepared films were characterized structurally and optically, using the powder X-ray diffraction (XRD) and UV analysis and Photoluminescence analysis. Crystallographic properties were analyzed through powder XRD. The XRD...
Kinematics of the human hand applied to the design of prosthesis
June 2014
This work shows the application of a mechanism of four bars synthetized function used in the development of a prosthetic device with an underacted movement, for its application in people with a mutilation level close to the distal dislocation of the wrist. A methodology is exposed for this, from which the procedure for obtaining the trajectory of the four bars mechanism through the function synthesis, which was...
Analysis and supervision of the water extraction of a thermal power plant
May 2014
The aim of this paper is to analysis the water treatment process in a thermal power plant (TPP). In fact, we present an application of a supervisory control and data acquisition (SCADA) system. Thus, an example of a SCADA system of the center of RADES in Tunisia was presented. Our contribution in this work consists in the analysis of the water loss in the TPP on the one hand and the supervision of the water extraction...
Study of vibrations by Raman spectroscopy low frequencies of the phase transition in pyridinium picrate (C6H2N3O7)-.(C5H6N)+
May 2014
The spectra of the crystals of pyridine picrate crude formula, C11H8N4O7, in the mid infrared (IR) and Raman are studied as a function of temperature. They show some changes, which allowed us to first track and describe the structural changes (in both directions under the effect of heat treatment) accompanying the phase transition between 358 and 383K observed by DSC, Rx. After gradual cooling, the reversibility of the...
Simulation analysis of the effect graded Zn(O,S) on the performance of the ultra thin copper indium gallium diselenide (CIGS) solar cells
May 2014
This paper indicated a numerical modeling of ultra thin copper indium gallium diselenide (CIGS) solar cells. An optimum value of the thickness of the structure has been calculated and it is shown that by optimizing the thickness of the cell, efficiency has been increased and cost of production can been reduced. Numerical optimizations have been done by adjusting parameters such as thickness of the layers and the gap. It...
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