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...
First principles study of the relative stability and electronic properties of the VN/GaN/VN interlayer
October 2016
Using first principles total-energy calculations within the framework of density functional theory, the relative stability and the structural and electronic properties of a VN/GaN/VN interlayer in sodium chloride (NaCl), cesium chloride (CsCl), nickel arsenide (NiAs), zinc-blende, and wurtzite structures were studied. The calculations were carried out using a method based on pseudopotential, employed exactly as...
Particle model of single bubble sonoluminescence
October 2016
The single bubble sonoluminescence is a phenomenon where the vapour or gas bubble trapped in a liquid collapse by emitting light. Sonoluminescence is most often characterized by the formation of an imploding shock and the plasma. However, studies show that in some cases neither an imploding shock nor a plasma has been observed. This study concerns a physical explanation of the Single Bubble Sonoluminescence (SBSL),...
Natural radioactivity level of clay, ceramic, and stone cooking dishes in Saudi Arabia
September 2016
Standards and guidelines are needed in the manufacture of household cooking dishes from clay, ceramic, and stone in Saudi Arabia. The radioactivity levels due to the presence of 40K, 232Th, and 226Ra in these materials were determined using gamma spectrometry equipped with high purity germanium (HPGe) detector. The activity concentrations of 226Ra ranged from 5.75 Bq kg−1 (Yemen stone sample) to 192.35 Bq...
Electrical resistivity and Seebeck coefficient of Pd81Ge19
September 2016
We report on the simultaneous measurement of resistivity and Seebeck coefficients in samples of Pd81Ge19 ribbons prepared by the melt spinning technique method and having a typical dimension of 40.0 mm × 1.75 mm × 0.028 mm. The investigation was performed using a new completely automated device in a large temperature range (from room to 700°C). Structural changes, crystallization times and heat...
Development of a real time blood pressure, temperature measurement and reporting system for inpatients
September 2016
In this work, a real time blood pressure, temperature measurement and reporting system for inpatients was developed. The function of this system is to constantly measure the blood pressure and temperature of a patient and send the measured values to the medical doctor or other relevant care givers through wireless link. The system is built around the STM32F103C8 Microcontroller programmed in C language which performs...
Characterisation of mortars from the Ottoman period in Algiers (Algeria) through their physical and chemical properties
September 2016
In traditional and historical Algerian architecture, one can find a series of mortars that were used for grouting and coating masonry. Although Algeria has a very rich heritage park, our interest mainly focuses on the mortars used in buildings from the Ottoman period, in Algiers and in particular, the mortars of the Citadel of Algiers, the Casbah and villa Mahieddine. This study allows us to determine the physical...
Mineral determination and radiological risk caused by geological formations from Iron Ore in Wadi Sawawin, Duba, Saudi Arabia
August 2016
Fifteen iron ore samples collected from Wadi Sawawin, Duba, Saudi Arabia were analysed using X-ray diffraction in order to determine mineral composition. Atomic absorption analysis was used to determine concentrations of Al, Ca, Fe, K, Mg, Bi, Pb, Th and U. Natural radioactivity concentrations were determined using gamma-ray spectrometry based on a hyper pure germanium (HPGe) detector; concentrations ranged from...
The third fundamental interaction of atoms
August 2016
It is shown that the existence of fundamental interactions cannot explain the chemical covalent bond. The existence of a new (hitherto unknown) fundamental interaction of atoms-internuclear attraction, which adequately interprets the chemical covalent bonding was proposed. Key words: Fundamental interaction, chemical covalent bonding, internuclear attraction.
The thermal behaviour of gases under the influence of infrared-radiation
August 2016
In contrast to the usual spectroscopic methods, the temperature of a gas embedded in a tube was measured here and not the intensity loss of the radiation. In order to minimize the interference by the tube, light-weight building materials were used, preferably Styrofoam, transparent plastic foils and aluminium foils. Sunlight as well as infrared (IR)-bulbs was employed as radiation sources, whereby near-IR is predominant...
Measurement of natural radioactivity in selected samples of medical plants in Iraq
July 2016
In present study, natural levels of radiation in some selected medical plants existing in the Iraqi stores were estimated to determine any activity concentration, radium equivalent and internal hazard index due to radionuclide, of 238U, 232Th as well as 40K, which occurs naturally. This activity concentration was identified by gamma-ray spectroscopy (NaI(Tl)). The findings indicate that, the rate of activity...
Light source estimation using feature points from specular highlights and cast shadows
July 2016
A method for light sources estimation is proposed in this paper. The method utilizes feature points in cast shadows to estimate near light source positions from estimated source directions using specular highlights. There are several methods that can be used to estimate light sources from scene images, using either cast shadows or specular highlights. However, most of them are limited to directional light sources. The...
Development of an identity management system for a web proxy server in a tertiary institution using anonymity technology
July 2016
The inability of a region to access a webpage, because of the ban being placed on users from that region as a result of its location policy, has led to this study. This problem is often solved by anonymizing web traffic by using The Onion Router (TOR). These tools, however, suffer from the problem of exposure of identity and also lack the ability to monitor web users. This study describes in detail a web proxy server...
Preliminary structural evaluation of an X-Field Onshore Niger Delta using 3D seismic data
June 2016
A structural evaluation of a post stack time migrated (PSTM) 3D seismic data over an X–Field in the eastern Niger Delta has been attempted. The objective of the study is to structurally evaluate the field with a view to identifying structural features such as faults, map geologic horizons and analyze reflection characteristics that might be a good lead to probable hydrocarbon accumulations. Results revealed that...
Geometric phases for two-mode squeezed vacuum state
June 2016
Although the geometric phase for one-mode squeezed state had been studied in detail, the counterpart for two-mode squeezed state is vacant. In this paper, we aim at the special case, namely, two-mode squeezed vacuum state. Furthermore, the total phase factor is to be written in an elegant form, which is just identical to one term of product of two squeezed operators. In addition, when this system undergoes cyclic...
Determination of the characteristic parameters for the modified Bessel-Gauss beams
June 2016
Some characteristic parameters of the Bessel- Gaussian beam were determined theoretically by direct analytical calculations. Variation of the final beam radius (ω) with the starting beam radius (ωo) was studied. The Rayleigh range of a Bessel-Gauss beam was calculated for each value of the minimum starting beam radius. The beam wavefront radius of curvature (R) was calculated as a function of starting...
Matter-antimatter models in cosmic and biologic systems
June 2016
The leading theories suggest that in the first fractions of the second following the Big Bang, equal amounts of matter and antimatter were formed, and annihilated. Therefore, the asymmetry of matter and antimatter, and formation of the visible universe is one of the major unsolved problems in physics. Surprisingly, when the major characteristics of the cosmic matter- antimatter interactions, were compared to...
Direct method for solving nonlinear strain wave equation in microstructure solids
May 2016
The modeling of wave propagation in microstructure materials should be able to account for the various scales of microstructure. In this paper, the extended trial equation method was modified to construct the traveling wave solutions of the strain wave equation in microstructure solid. Some new different kinds of traveling wave solutions was gotten as, hyperbolic functions, trigonometric functions, Jacobi ...
Solar flare effects (SFE) on geomagnetic fields across latitudes
May 2016
A comprehensive study of Solar Flare Effects (SFE) across latitudes has been carried out using an extensive data set of two geomagnetic elements H and Z selected from 1997 to 2005. The X (intense) and M (medium) solar flares were examined under quiet conditions. Nine stations extending from equatorial to high latitudes were used in the study. Data employed in this work include minute data of geomagnetic field, solar...
Slip flow of a second grade fluid past a lubricated rotating disc
April 2016
Slip flow of a second-grade fluid past a lubricated rotating disc is studied. The disc is lubricated with a power-law fluid. The interfacial conditions between fluid and lubricant are imposed on the surface of disc by assuming a thin lubrication layer. The numerical solutions are obtained using Keller-Box method. The effects of slip parameter and Weissenberg number on the three components of fluid velocity and pressure...
Purity-performance relationship of anthocyanidins as sensitizer in dye-sensitized solar cells
April 2016
A comparative analysis between crude and purified extracts obtained from withered leaves of Terminalia catappa (T. catappa) and pure compounds of anthocyanidins as organic sensitizers in solar cells. The chemical and electronic properties of the extracts and the pure anthocyanidins were examined using spectroscopic studies: ultraviolet (UV), Fourier transform infrared (FT-IR) and gas chromatography coupled with flame...
Analysis of elastic scattering data below, atop and above the delta resonance using inverse scattering theory
April 2016
The simple local optical potential adopted in analyzing successfully elastic scattering data in the delta resonance region has been emphasized here. This is based on obtaining the same nature for the potential by extracting potential points from available phase shifts at 114, 163, 240 and 340 MeV using inverse scattering theory within the framework of Klein-Gordon equation. Luckily, and as expected, the...
Dielectric study of calcium doped barium titanate Ba1-xCaxTiO3 ceramics
March 2016
Calcium doping effect on the ferroelectric properties of Ba1-xCaxTiO3: BCTx (x = 0.01, 0.05, 0.1) ceramic material prepared via the sol-gel process was studied. X-ray diffraction (XRD) showed that the powders of calcined BCTx at 900°C crystallize in a pure phase of perovskite type without secondary phases. Microstructural morphology was analyzed by Scanning Electronic Microscopy (SEM). Dielectric measurements were...
A new solitary wave solution of the perturbed nonlinear Schrodinger equation using a Riccati-Bernoulli Sub-ODE method
March 2016
The Riccati-Bernoulli Sub-ODE method is used for the first time to investigate exact wave solution of the perturbed nonlinear Schrodinger equation with Kerr law non linearity which describes the propagation of optical solitons in nonlinear optical fibers that exhibits a Kerr law non linearity. An infinite sequence of exact solutions can be obtained according to Backlund transformation. The proposed method also can be...
Space charge kinetic treatment in Langmuir probes with cylindrical geometry
March 2016
In this paper, an analysis of the space charge build up in the interelectrodic region of a velocity analyzer with cylindrical symmetry is performed using kinetic theory. Thus the present treatment includes temperature effects. Azimuth symmetry is also assumed. A detailed and comparative analysis, between planar and cylindrical electrodes, is carried out, showing the advantages of each kind of...
Investigating H and Z geomagnetic component disturbance field in the mid-latitude
March 2016
The relationship in the variations of geomagnetic horizontal component (H) and vertical component (Z) in Boulder station (40.1°N, 254.8°) has been investigated. In the analysis, series of significant changes in amplitude and period are observed in H as well as in Z during the day-time. The changes in H and Z for the average yearly diurnal variations and for the monthly variations do not exhibit consistent...
Biodegradation with heterogeneous catalyst in the production of biogas from wheat wastes, rice husk and spent grains
February 2016
Biodegradation with heterogeneous catalysts were successfully carried out in the production of biogas from wheat wastes, rice husk and spent grains. Five digesters were charged with spent grains/clay soil, spent grains/lime stone, rice husk/clay soil, rice husk/lime stone and wheat wastes/potash, respectively. Clay soil, limestone and potash were used as catalysts for optimizing and to speed up the chemical reactions in...
Empirical model for estimation of global radiation from sunshine duration of Ijebu-Ode
February 2016
Empirical models to estimate global solar radiation require the development of a set of equations that relate it to other meteorological parameters and from the monthly average daily value of clearness index and relative sunshine spanning of a period of 5 years, the Angstrom- Prescott model was developed for the estimation of global solar radiation of Ijebu-Ode (Lat. 6.81â°N. Long. 3.92â°E), a tropical region of...
Analytical model of heavy-particle pollutant transport in estuary
February 2016
The aspects of heavy-particle diffusion in the tropical estuary is investigated. The two dimensional advection-diffusion equations with tidal and settling velocity were solved with steady state approximation. An analytic solution was obtained in term of Cosines Integral function. The results showed that the profile of concentration follow a tidal cycle with the concentration decrease when the tidal speed is low and...
Extraction and characterization of biodiesel from Borassus aethiopum and Cassia sieberiana
January 2016
Biodiesel was successfully produced from Borassus aethiopum and Cassia sieberiana seeds using the trans-esterification method. The biodiesels produced were characterized by physico-chemical properties of acid value, iodine value, specific gravity, refractive index, viscosity, density, flash point, cloud point and pour point. Results showed that the biodiesels produced have values which compared well with the European...
Spectroscopic determination of the electrical parameters of a micro-wave discharge in helium plasma
January 2016
This paper is based on the study of the emitted radiation by electrical discharge plasma, caused in the helium a pressure of 4.8 Torr, a power MW of 108W. The study numerical model allows the identification of several spectral lines. With the Boltzmann method the study have calculated the electronic temperature (Te=3.23eV), it corresponds to the classification scale of plasmas. The application of the Saha law gives the...
Theoretical calculation of half-metallic ferromagnetism in Al1-xVxN compound
January 2016
Using the first-principles in the framework of density functional theory, the structural properties, electronic structure, and magnetism of V-doped aluminum nitride (AlN) were investigated. The calculations were carried out using the method based on pseudopotential, employed exactly as implemented in Quantum ESPRESSO code. For (x = 6.25%) Al0.9375V0.0625N and (x = 12.5%) Al0.875V0.125N concentrations, a half-metallic...
Similarities between basic mechanisms of cosmic and biologic systems
January 2016
Similarities in the birth and development of cosmic and biologic systems provide unexpected proof for the major theories of formation of the universe - the Big Bang and the String theories. They include similarities in the theory of their formation, one unit origin, preexisting states, conception, fertilization, gestation, information, basic units, flatness, fluctuations, smoothness, lumpiness, reproductive and...
Gravitational effect on surface waves in a homogeneous fibre-reinforced anisotropic general viscoelastic media of higher and fractional order with voids
December 2015
In this paper, gravitational effects on propagation of surface waves in a homogeneous fibre-reinforced anisotropic general viscoelastic media of higher order with voids is investigated. The general surface wave speed is derived to study the effects of gravity on surface waves. Particular cases for Stoneley and Rayleigh waves are discussed. The results obtained in this investigation are more general in the sense that...
Analytical and numerical study of a pulsatile flow in presence of a magnetic field
December 2015
This paper deals with the effects of magnetic field on heat transfer in a pulsatile flow. A mathematical model is developed to investigate the impact of magnetic field on the velocity and the temperature distributions between two concentric ducts. Finite differences method is used in order to solve the dimensionless governing equations, and implicit schemes for velocity and temperature are obtained. The effects of...
Influence of etching on the optical properties of a-plane-oriented ZnO epilayers grown by plasma-assisted molecular beam epitaxy
December 2015
A-plane-oriented ZnO epilayers grown by plasma-assisted molecular beam epitaxy were studied with respect to their optical properties. 10K-photoluminescence (PL) and reflectivity were used to analyze various 2 µm-thick ZnO films etched at different etching profile. The PL spectra show the band emission of the structures become narrower when the etching profile increase. At 0.75 µm etching profile, two...
Dark energy and gravity: Reconsidering Newton’s law of universal gravitation
November 2015
In many theories of gravity, the cause of gravity is neither mentioned nor clarified yet. Dark energy, which makes the universe accelerate and push all matters in the universe apart, has repulsive power. Every matter in space is equally pressured by this repulsive force from all directions. It is assumed that this force comes from infinity in space. However, if matters exist nearby, the matters shield each other from...
On solar wind speed distribution and geomagnetic activity during solar cycle 23 and the early ascending phase of solar cycle 24
November 2015
This paper investigates solar wind repartition through four classes of solar events: (1) one class of quiet days (QD) caused by slow solar wind (V< 450 km/s), and three disturbed activities, where V ≥ 450 km/s, (2) recurrent wind (RW), (3) shock wind (SW), (4) fluctuating wind (FW). RW class is characterized by recurrent high solar wind extended on several solar rotations. SW class is caused by CMEs events. FW...
Polylactic acid (PLA) viscoelastic properties and their degradation compared with those of polyethylene
November 2015
Polyethylene (PE) films are widely used in packaging. PE is a thermoplastic manufactured from nonrenewable petroleum resources. Due to its non–biodegradability, its films have posed serious pollution problems e.g. visual pollution, blockage of gutters and drains, choking of animals etc. Suitable replacements for PE films especially for single use only, are the starch based thermoplastics such as Polylactic acid...
A statistical analysis of Lorentz invariance in entropy
October 2015
After relativity was introduced by Einstein in 1905, several attempts were made to reformulate the other fields of physics to make them consistent with the postulates of Relativity. However, relativistic reformulation remains a bone of contention even today after over a hundred years since Einstein's epoch making papers. This is mainly due to seemingly conflicting yet consistent ways of defining the macroscopic...
A study of structural, optical and dielectric properties of Eu2O3 doped borate glass
October 2015
Recent technological applications have generated more interest in the studies of different types of glasses. The wide applications of glasses take place due to their interesting properties such as low thermal expansion, high softening temperature, high resistance to chemical attack, high refractive index with low dispersion and mechanical strength. Eu2O3 doped borate glasses were successfully synthesized by melt...
Hydrothermal synthesis and structural characterization of an organically-templated open-framework trimolybdates
October 2015
A new one-dimensional coordination polymer formulated as [C2H10N2] [Mo3O10], 1, has been synthesized under hydrothermal conditions in the presence of ethylenediamine. The surface morphology of the as-synthesized product reveals colorless rod-like single crystals of 1. The compound crystallizes in monoclinic space group P21/n with a = 8.08 Å, b =14.39 Å, c = 8.89 Å; β = 97.76°, V = 1033.65(12)...
Crystal size effect on the photoluminescence of calcium aluminate doped Mn2+ nanocrystals
October 2015
Research into finding environmentally friendly, efficient and economic viable nanophosphors is still ongoing as the incorporation of radioactive substances into phosphors to improve their short time luminescence poses serious environmental concern. The present paper investigates the effect of particle size on the, morphology and photoluminescence of environmentally friendly CaAl2O4: Mn2+ nanocrystals. The phosphor was...
Design of an explosive detection system to investigate the luggage of aircraft passenger based on neutron-gamma technique
September 2015
In this study an explosive detection system to investigate luggage of air travelers by the Monte Carlo N-Particle Transport code (MCNP5) has been designed. Concrete as a commonly shielding material was the main part in the designed system. Pulsed neutron generator with 14.1 MeV neutrons was used as a neutron source. Two time gates were used in gamma detection process. The lead was used as a secondary gamma rays...
Ab-initio calculations of magnetic behavior in wurtzite AlxV1-xN compound
September 2015
The density functional theory was employed in order to study the structural, electronic, and magnetic properties of the AlxV1-xN (x=0.25, 0.50, and 0.75) compound in the wurtzite-type structure. The calculations were executed using the method based on pseudopotential, employed exactly as implemented in Quantum ESPRESSO code. For the description of the electron-electron interaction, generalized gradient approximation...
A case study of aeromagnetic data interpretation of Nsukka area, Enugu State, Nigeria, for hydrocarbon exploration
September 2015
The aeromagnetic data of Nsukka area was interpreted qualitatively and quantitatively. Standard Euler deconvolution, Source Parameter Imaging (SPI), Forward and Inverse modeling techniques were employed in quantitative interpretation with the aim of determining depth/thickness of the sedimentary Basin, magnetic susceptibilities and type of mineralization prevalent in the area. Oasis montaj 6.4.2 software and potent...
Effect of tempering on the microstructure and mechanical properties of austenitic dual phase steel
August 2015
This research is focused on the effect of tempering on the microstructure and mechanical properties of 0.23%C austenitic dual phase steel locally manufactured in Nigeria. The as-received steel was normalized in order to annul the thermo-mechanical history of the steel. Thereafter, some of the normalized samples were austenetized at 850°C for 30 min and then slowly cooled in the furnace to the (α+ϒ)...
Performance enhancement of incoherent spectral amplitude encoding-optical code division multiple access (SAE-OCDMA) by using dispersion compensation fiber Bragg grating (FBG)
August 2015
Incoherent spectral amplitude encoding optical code division multiple access (SAE-OCDMA) based on fiber Bragg grating (FBG) is one promising technique aim to improve local area networks to have longer span telecommunication network type. In this study, the performance enhancement incoherent SAE-OCDMA is achieved when a dispersion compensation fiber Bragg grating (DCFBG) and erbium doped fiber amplifier (EDFA) are used...
Geophysical assessment of potential hydrological units in hydrologically challenged geomaterials of Makurdi, Benue State, Nigeria
August 2015
A geo-electric survey employing the Vertical Electrical Sounding (VES) was carried out in order to access the distributions of electrical and hydraulic parameters of hydro-geologic units in some locations of Makurdi where groundwater resources are difficult to tap. A total of fifteen geo-electric soundings were acquired. The contour maps were generated using the results. From the bulk aquifer resistivity and water...
Existence of solution for a third order three point boundary value problem at resonance
August 2015
Using coincidence degree arguments we prove some existence results, for a third order three point boundary value problem at resonance. Key words: Resonance, coincidence degree, third order, three point boundary value problem.
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