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,...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
Modeling and simulation of watershed erosion: Case study of Latian dam watershed
May 2014
The Latian Dam is one of the important drinking water resources of Tehran, and it also has a role in preventing the flood. It is very important to keep the quality of water and preventing the dam from filling. Considering the special aspects of RUSLE model, it was used for estimating the amount of erosion in the watershed of dam including the sub-basins: Jajrood River, Kond River and Afjeh River, and then compared with...
Angular symmetry of space-time and the spinor representation of Poincaré group
May 2014
In the paper, a relativistic theory is suggested; we add three independent angles to the four coordinates of the Minkowski space that define the (x, t) - position of a moving local observer. These angular coordinates define the orientation of an observer under free rotations and they allow us to introduce the generators of the Poincaré group in the angular representation. Instead of a multi-component wave...
Properties of Bertrand curves in dual space
May 2014
Starting from ideas and results given by Özkaldi, Ä°larslan and Yaylı in (2009), in this paper we investigate Bertrand curves in three dimensional dual space D3. We obtain the necessary characterizations of these curves in dual space D3. As a result, we find that the distance between two Bertrand curves and the dual angle between their tangent vectors are constant. Also, well known characteristic property of...
An electrostatic lens system for the deceleration of high intensity heavy ion beams
April 2014
This work focuses on the design and implementation of an electrostatic lens system to produce high-intensity, low-energy ion beams, by means of numerical simulation of the beam trajectories (SIMION 7). The lens design was optimized using the simulation data obtained with a performance characteristics of the electrostatic lens system. This lens system maintains good beam focal quality for the deceleration of heavy...
The first integral method and its application for finding the exact solutions of nonlinear fractional partial differential equations (PDES) in the mathematical physics
April 2014
In this article we apply the first integral method to construct the exact solutions of some nonlinear fractional partial differential equations (PDES) in the sense of modified Riemann–Liouville derivatives, namely the nonlinear fractional Zoomeron equation and the nonlinear fractional Klein- Gordon- Zakharov system of equations. Based on a nonlinear fractional complex transformation, these two nonlinear fractional...
Physicochemical characterization and inhibitive performance evaluation of Commiphora kestingii gum exudate in acidic medium
April 2014
Gas chromatographic-mass spectrometry (GCMS), fourier transformed infra-red spectroscopy (FTIR) and physicochemical analysis of Commiphora kestingii gum have been carried out. The corrosion inhibition characteristics of C. kestingii (CK) gum on aluminium in sulphuric acid media were also investigated at 303 and 333K using gravimetric and scanning electron microscopic studies (SEM) method. The study revealed that the gum...
Theoretical spin assignment and study of the A~100 – 140 superdeformed mass region by using ab formula
April 2014
Using an empirical formula of rotational spectra which consists of two parameters a and b (known as ab formula) and derived from the Bohr-Hamiltonian, we extract the spins of fifteen superdeformed bands observed in the A~ 100-140 mass region. The two parameters "a" and "b" were determined by using a search program to fit the proposed transition energies with their observed values. The calculated...
Influence of pressure from compression textile bands: Their uses in the treatment of venous human leg ulcers
April 2014
The aim of study was to evaluate pressure distribution characteristics of the elastic textile bandages using two instrumental techniques: a prototype instrument and a load transference. The prototype instrument which simulates shape of real leg has pressure sensors which measure bandage pressure. Using this instrument, the results show that elastic textile bandages presents different pressure distribution...
On the Bishop curvatures of involute-evolute curve couple in E3
April 2014
In this study, the relations between of the Bishop curvatures of involute-evolute curve couple were examined in . Also, the relation between of the Bishop frames of these curves was given. Moreover, the relations between of curvature radii of these curves were investigated. Lastly, in the case of these curves were planar curves, some corollaries were obtained. Key words. Bishop frame, Bishop curvatures,...
Analysis of land development conformity obtained using photogrammetric and remote sensing methods with Geographic Information System (GIS) technology
April 2014
Information regarding spatial management can be obtained using various methods, including satellite and photogrammetric technology. However, different methods give different results in terms of spatial resolution. Nowadays, photogrammetric data used for determining the spatial management usually employs pixels representing 0.25 m; still, the majority of the data are orthophotomaps with pixels representing 0.5 m; whereas...
Geophysical investigation of the effects of sewage in the soil at university of Nigeria, Nsukka, Enugu State, Nigeria
March 2014
Geophysical investigation was carried out to detect the spread of sewage effluent and to locate the sources and delineate migration paths and the extent of leachate plume. The study was to find out the geological formations that are the most conductive layers in the sewage site for the free flow of the contaminants. Soil tests showed that hydraulic conductivity, bulk density and water retention were variable in sewage...
Health risk assessment in relation to heavy metals in water sources in rural regions of South East Nigeria
March 2014
Geophysical investigation was carried out to detect the spread of sewage effluent and to locate the sources and delineate migration paths and the extent of leachate plume. The study was to find out the geological formations that are the most conductive layers in the sewage site for the free flow of the contaminants. Soil tests showed that hydraulic conductivity, bulk density and water retention were variable in sewage...
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