Regional variation of columnar refractivity with meteorological variables from climate monitoring satellite application facility (CM SAF) data over Nigeria
May 2013
Data from satellite application facility on climate monitoring (CM SAF) have been used to estimate and study seasonal variation of columnar refractivity in relation with relative humidity and temperature for twenty six stations categorized into four climatic regions (coastal, Guinea savannah, midland and sub Sahel regions) over Nigeria. Mean, standard error, maximum, minimum values and ranges of these...
Lead contamination of traditional hand-dug wells in parts of Kwale County, Kenya
May 2013
People’s health, behavior and intellect to a certain extent are a function of their environment. One important component of this environment is water, a basic necessity that human beings cannot do without. The water available, however, is not always safe for human consumption due to contamination. Among the many water contaminants, lead (Pb) is one of the most dangerous due to its bio-accumulative nature and high...
Toxicity of arsenic (As) on seed germination of sunflower (Helianthus annuus L.)
May 2013
The effect of different levels (2, 4, 6, 8 and 10 mg/L) of arsenic (as sodium arsenate and sodium arsenite) on germination percentage, mean germination time, days to 50% germination, plumule and radicle length and seedling vigour index of four sunflower cultivars (FH-331, FH-385, FH-405 and FH-415) was determined under laboratory conditions. Germination percentage was gradually decreased with the increase in arsenic...
Culmination of the Quantum theory in Sri Aurobindo’s poetic consciousness
May 2013
The Quantum theory visualizes that uncertainty is the ultimate truth behind the dualism of wave and particle at the sub-atomic plane of Matter. It does not find any physical law capable of explaining the physical state in which the conversion of wave into particle and vice-versa takes place at the sub-atomic plane of Matter. In fact, the conversion evades all the physical laws on account of which Werner Heisenberg...
Magnetic Field Effects on Entropy Generation in Heat and Mass Transfer in Porous Cavity
May 2013
The entropy generation for natural convection heat and mass transfer in a two dimensional porous cavity subjected to a magnetic field is selected for numerical investigation. The Darcy model is used in the mathematical formulation of the fluid flow in porous media. The mathematical model is derived in dimensionless form and the governing equations are solved using the finite volume method. The governing parameters arise...
Applications of Schrödinger equation in general Besov spaces
May 2013
In this paper, we obtain solution of Schrödinger equation in general Besov spaces. Precise results on and general Besov estimates of the maximal function of the solutions to the Schrodinger equation are given. The obtained results improve some recent results. Further, we shall consider estimates of general -norm and the general Besov type norm of integrals of this kind by means of the...
Comparison study between differential transform method and Adomian decomposition method for some delay differential equations
May 2013
A numerical method based on the differential transform method (DTM) and the Adomian decomposition method (ADM) is introduced in this paper for the approximate solution of delay differential equation (DDE). The algorithm is illustrated by studying an initial value problem. The results obtained are presented and show that only few terms are required to obtain an approximate solution which is found to be accurate and...
On the Fekete-Szegö like inequality for meromorphic functions with fixed Residue
May 2013
In the present paper, we will consider the class of meromorphic starlike functions with fixed residue . Silverman et al. (2008) has obtained sharp upper bounds for Fekete-Szegö like functional for certain subclasses of meromorphic functions. In this paper, we will find sharp upper bounds for for the class meromorphic starlike functions with fixed residue . The aim of the...
On three-dimensional quasi-Sasakian manifolds admitting semi-symmetric metric connection
May 2013
The object of the present paper is to study three-dimensional quasi-Sasakian manifold equipped with semi-symmetric metric connection. The geometrical properties of conformal curvature tensor and the conservative quasi-conformal curvature tensor are discussed with such connection. Among other we have deal the conservative properties of quasi-conformal curvature with respect to semi-symmetric metric...
On enhanced control charting for process monitoring
May 2013
The information on auxiliary characteristics helps significantly in increasing the efficiency of control charts for detecting shifts in process parameters. In this study we proposed Shewhart type control charts, namely the chart, the chart and the chart, which utilizes information on two auxiliary characteristics (X and Z) for improved monitoring of process location parameter...
Frame structure for Mobile multi-hop relay (MMR) WiMAX networks
May 2013
Mobile Multi-hop Relay (MMR) WiMAX network uses Relay stations (RSs) to extend the cell coverage, and enhances the link quality and the throughput. In MMR WiMAX networks, the number of hops between the Subscriber stations (SSs) and the Base station (BS) is allowed to be more than two hops when Non transparent RS (NT-RS) is used. However, this requires modification to the frame structure of NT-RS to reduce the delay of...
Mobile agent based clustering and maintenance using secure routing protocol for mobile ad hoc network
May 2013
Routing in mobile ad hoc network is the challenging task due to the dynamic nature and resource limitations of network. Network clustering deals with partitioning network into clusters based on some rules. Clustering guarantees limited resource utilization and network scalability. In this paper, we mainly focused on using mobile agents for collecting information about cluster members and cluster maintenance. Ensuring...
Multi-band meta-material structures based on hexagonal shaped magnetic resonators
May 2013
In this paper, we propose a new multi band meta-material structure composed of a unit cell that has multiple hexagonal-shaped metal rings printed one inside the other. The introduced meta-material composition exhibits multi-resonant behavior due to distinct magnetic resonances caused by the self and mutual coupling of each inclusion. The number of distinct magnetic resonances is determined...
A method of dual-process sample selection for feature selection on gene expression data
May 2013
A method of dual-process sample selection based on support vector machine (SVM) is proposed to select informative features in this paper. Samples in a training set are used to train a SVM model, and the samples excluding support vector samples are chosen to select critical features in the procedure of recursive feature elimination (RFE). The effect of the dual-process sample selection method on feature selection is...
A preliminary investigation of the signal-to-noise ratio of Toro and Nsukka stations in Nigeria
April 2013
Preliminary investigation of Toro and Nsukka stations from the Nigerian National Network of Seismographic Stations (NNNSS) with respect to Signal-to-Noise-Ratios (SNR) has been performed from noise observation and numerically. The results showed that Toro has higher SNR compared to Nsukka. Six months data collected from the stations in 2012 were used for the study. Nsukka Station in the southern part of Nigeria...
Widely tunable micro electromechanical systems (MEMS)-vertical-cavity surface-emitting lasers with single transverse mode operation
April 2013
In this paper, a micro electromechanical systems vertical-cavity surface-emitting laser (MEMS-VCSEL) with asymmetric double oxide aperture and highly strained GaInNAsSb quantum wells for widely tunable, single mode and high temperature operation has been investigated. The MEMS-VCSEL is based on an integrated two-chip concept which allows us to extend the single wavelength performance to a continuously tunable,...
Multi-objective application of granular activated carbon in the production of carbonated beverage process water and bottled water
April 2013
There are number of issues in soft drink industries’ mode of GAC operation, however, this study focuses on three issues like control of regeneration breakthrough in line with Chlorine and THM breakthrough; its frequency of regeneration and finally the competitive adsorption of different THM on two different types of GAC and extrapolation of result to full scale plant. All the experiments were conducted using rapid...
Decomposition method for fractional partial differential equation (PDEs) using Laplace transformation
April 2013
In this Paper, we propose an efficient combination for the solution of partial differential equations (PDEs). In a similar context, decomposition coupled with Laplace transform is applied to solve partial differential equations of fractional order. It is observed that the proposed technique is highly suitable for such problems. The results of the proposed scheme are highly encouraging and efficient. It is also...
Environmental production of fashion colors from natural dyes
April 2013
Dyeing is one of the most delightful textile arts which are an important branch in fashion design. Natural dye is a fascinating phenomenon that enticed researchers to their chemistry and production of fantastic novel hues to explore the point that no other dyes provide a better opportunity teaching how to protect and respect the environment. In this research, silk fabric was dyed by a mixture of different percentages of...
Formation and identification of counter electrojet (CEJ)
April 2013
This study investigates the possible occurrence of counter equatorial electrojet (CEJ) and a quicker method for identification of CEJ. Data from a chain of magnetic observatories of World Data Center for Geomagnetism in Tokyo, Japan, was employed. It is strikingly interesting to observe that most CEJ occurred from morning through new dusk, with almost the same pattern of dHin depression. In Ascension Island (ASC),...
Suggested formulas for half-life time of unstable nuclei: Effect of the isospin asymmetry
April 2013
Using the available data of half-life time of unstable nuclei given that the number of protons is greater than the number of neutrons, an elaboration was made on the dependence of half-life time of these nuclei on the value of the difference between the two numbers, which is referred to as the isospin asymmetry effect. The available data of half-life time was analyzed and two formulas of half-life time were suggested....
Three-dimensional max-type cyclic system of difference equations
April 2013
We show that all solutions of the max-type cyclic system of difference equations , , where , is real positive number, and initial values and , are periodic with period three. Finally we generalized the results for more general system which is finite dimensional system. Key words: Max-type system, difference equations,...
Fuzzy programming and data envelopment analysis for improving redundancy-reliability allocation problems in series-parallel systems
April 2013
Redundancy-reliability allocation problems in multi-stage series-parallel systems under uncertain environments are addressed in this study. First, a multi-objective programming model is formulated for simultaneously maximizing system reliability and minimizing system total cost. Due to the nature of uncertainty in the problem, the fuzzy set theory and technique are used to convert the deterministic multi-objective...
Meditator’s non-contact effect on cucumbers
April 2013
We clearly show the existence of an example of non-contact effect in which the “presence” of a meditator affects bio-samples without physical contact. This is the first report in the world to show this type of effect by scientific measurements. We used edible cucumber slices as bio-sensors and measured the concentrations of gas emitted from the slices by a technique developed by our group. The...
Organic matter and trace metals levels in sediment of bonny river and creeks around Okrika in Rivers State, Nigeria
April 2013
Analysis was carried out on the sediment of Bonny River and creeks around Okrika in order to determine the concentrations of organic matter, lead, nickel, vanadium and cadmium as well as their probable sources and diagenesis. Samples for trace metal analysis were prepared by acid digestion and analysed by atomic absorption spectrophotometry. Organic matter content was determined by the method of Walkey and Black. Mean...
Integrated geophysical investigation for post-construction studies of buildings around School of Science area, Federal University of Technology, Akure, Southwestern, Nigeria
April 2013
An integrated geophysical investigation involving ground magnetic, very low frequency (VLF-EM), and electrical resistivity methods using dipole–dipole array and schlumberger vertical electrical sounding (VES) techniques were conducted around School of Science Area Obanla, Federal University of Technology, Akure, for post construction studies in assessing building foundation integrity. Two traverses were...
The theory of relativity of motion: A new approach
April 2013
For more than a century, people’s belief about special relativity and its formulas was, in fact, inaccurate, because Einstein fails by delaying in the wrong conception. However, one of these formulas is correct, by chance, but the others are incorrect. In the present approach, new expressions for time dilatation, composition of velocities, different masses (energy and inertial masses) and energy are demonstrated...
The strength of the atom localization coupling with the standing-wave field under the dephasing rate influence
April 2013
We investigate the localization of the four-level V-type atom inside a classical standing-wave field through the absorption spectrum of the weak probe field. The expression of the probe absorption spectrum is derived analytically via perturbation treatment of a weak probe field. Numerical results and discussion of the probe susceptibility spectrum behaviour via non-perturbation treatment of the density matrix elements...
Surface waves propagation in fibre-reinforced anisotropic elastic media subjected to gravity field
April 2013
The objective of this paper is to investigate the surface waves in fibre-reinforced anisotropic elastic medium subjected to gravity field. The theory of generalized surface waves has firstly developed and then it has been employed to investigate particular cases of waves, viz., Stoneley waves, Rayleigh waves and Love waves. The analytical expressions for waves velocity and attenuation coefficient are obtained in the...
Estimated electric power consumption by means of artificial neural networks and autoregressive models with exogenous input methods
April 2013
The growth electric energy demand in the industrial and commercial sectors and in public and private buildings represents a problem to estimate electrical consumption in these sectors in order to avoid fines imposed by the respective companies supplying electricity. This study presents artificial neural networks (ANN) and autoregressive models with exogenous input (ARX) models to calculate and to predict the electrical...
Effects of adhesive thicknesses on the stress distribution in prismatic plug-in joints
April 2013
The aim of this study is to research the effects of adhesive thickness, which is one of the factors that affect the stress distribution in the prismatic plug-in joints. The effect of adhesive thickness was theoretically researched in the study. Epoxy-based and acrylic-based adhesives, which are widely used in combining metal joints, were applied. After testing the mechanical characteristics of the adhesives,...
Comment on "Steady mixed convection stagnation-point flow of upper convected Maxwell fluids with magnetic field" [International Journal of non-linear mechanics, 44(2009):1048-1055]
April 2013
In the present comment, we point out a major flow found in the paper "Steady mixed convection stagnation-point flow of upper convected Maxwell fluids with magnetic field" [International Journal of non-linear mechanics, 44(2009):1048-1055]. Key words: Induced magnetic field, visco-elastic fluid, magnetic Reynold number.
Development of two-dimensional solver code for hybrid model of energy absorbing system
April 2013
This paper treats the dynamic and energy absorption responses of nonlinear spring-mass system using a developed two dimensional solver code. The influence of spring stiffness and various mass configurations on the impact response was investigated using validated models. Results are quantified in terms of important impact response and indicate that an assembly of spring-mass system can be employed to examine the impact...
Structural numerical analysis of a three fingers prosthetic hand prototype
April 2013
In spite of the importance of the finite element method analysis in the mechanical design, there are a few research works in the prosthetic hands design area that use this tool. This work uses the finite element method to perform a structural analysis of a prosthetic hand prototype during the cylindrical and tip grasp. Through geometric relations, a set of equations was developed in order to define the position of the...
Extended reach spectrum-sliced passive optical access network
April 2013
Geoelectrical investigation of aquifer problems in Gosa area of Abuja, North Central, Nigeria
April 2013
The study of aquifer problems in Gosa area of Abuja, North-central Nigeria, has been undertaken. Abuja, the capital city of Nigeria, is underlain by Precambrian basement rocks. Vertical electrical sounding (VES) was carried out at twelve locations within and around the Gosa area. The interpretation of the data obtained from the sounding revealed that six non-aquiferous geoelectrical layers overlie the unfractured...
Correction of topological errors in geospatial databases
March 2013
The problems related to geometrical correctness of maps gathered and stored by the geographic information system (GIS) computer systems are still present nowadays. Firstly, digitization of traditional paper maps is still in progress all over the world (the maps are being converted to a vector form and stored in relational databases). Secondly, the existing digital maps are being constantly updated with use of manual and...
Studies on energy absorption and exposure buildup factors in some solutions of alkali metal chlorides
March 2013
Buildup of photons has been investigated through the solutions LiCl, NaCl and KCl with different salt contents in the energy region 0.015-15 MeV up to a penetration depth of 40 mean free paths. Two types of buildup factors, the gamma ray energy absorption () and exposure buildup factors () have been calculated simultaneously using the five parameter geometric progression (G-P) fitting formula. The influence of photon...
Effective rigid perfectly plastic models to predict deflection and residual velocity of post local failure motion of impulsively loaded circular plates
March 2013
Two deformation models are proposed for clamped circular plates undergoing pulse loadings. By these models, behaviors of plate are studied effectively for the situations before and after local failure. In the first model, it is assumed that impulsive load is uniformly distributed and final deformation is of a spherical dome shape. In order to analyze this model, it assumed that under the shock wave, the mechanism of...
Methodological approach of selecting a vibration indicator in monitoring bearings
March 2013
A rolling bearing is an important element in a rotating machine. Whatever the operating conditions, it is subject to fatigue which causes spalling. In aiming to obtain the most possible real fatigue curve, the vibration level is shown according to different statistical indicators such as the RMS (Root Mean Square), the kurtosis, the crest value, the crest factor and the peak ratio, then to choose the best of them that...
Temperature dependence of wall-plug efficiency of high power laser diodes
March 2013
Temperature dependence of wall-plug efficiency of high power laser diodes is theoretically analyzed in terms of experimentally measured parameters of the device. This issue has an influence on the available power output and on the degradation mechanism. High power laser diodes have become increasingly important as the output power of such devices continues to rise. The present calculations revealed that the decrease of...
Effect of milling conditions on the formation of ZnFe2O4 nanocrystalline
March 2013
The effects of milling parameters on the formation of ZnFe2O4 nanocrystalline are studied. Powder mixtures of ZnO and Fe2O3 were milled in high energy vibrant ball milling for different balls to powders mass ratio and milling times. X-ray diffraction and scanning electron microscopy are used to characterize the powders. A crystalline size and lattice parameter are obtained from Scherrer formula and the...
Traffic accident in India in relation with solar and geomagnetic activity parameters and cosmic ray intensity (1989 to 2010)
March 2013
We studied the relation between deaths due to traffic accident in India and geomagnetic activity indices: Kp, Ap, Dst and solar activity (SA) parameters, sun spot number, solar flare index (FI), coronal index (CI) and yearly average of cosmic ray intensity, observed during the period of 1989-2011. It is seen that rate of death by traffic accident are well correlated with these parameters. We have found large negative...
A modified surface wave particle motion discrimination process
March 2013
The difference between polarization properties of surface waves and noise provides us with a simple way of discriminating the fundamental mode surface waves on three-component seismograms. In this process, vertical, radial and transverse component amplitudes at each frequency are weighted according to a theoretical three-dimensional particle motion pattern for a selected window length (WL) and moving interval (MI). For...
Temperature dependent current-voltage characteristics of electrodeposited p-ZnO/n-Si heterojunction
March 2013
p-ZnO thin films were grown by electrochemical deposition (ECD) technique on n-Si substrate in order to form the p-ZnO/n-Si heterojunction. Hall measurement and hot probe techniques were used to determine the conductivity type of the ECD grown ZnO thin film. X-ray diffraction measurements revealed the peaks corresponding to the ZnO crystal directions of (002), (101) and (200) confirmed by the Joint...
Hydromagnetic flows of a mixture of two Newtonian fluids between two parallel plates
March 2013
The paper aims to study the flow of a binary mixture of electrically conducting, incompressible and viscous fluids between two parallel plates in the presence of a transverse uniform magnetic field. The solution of such a flow model has many applications in magnetohydrodynamic (MHD) power generators, MHD pumps, MHD accelerators, and MHD flowmeters. Exact solutions have been obtained for the following four problems: (1)...
Performance evaluation of multi objective differential evolution algorithm (MDEA) strategies
March 2013
This study presents the results of comparison of the four strategies of multiobjective differential evolution algorithm (MDEA) namely, MDEA1, MDEA2, MDEA3 and MDEA4 in solving five test problems and an engineering design problem. The test problems are ZDT1, ZDT2, ZDT3, ZDT4 and ZDT6. MDEA is a multiobjective algorithm developed from differential evolution, which is an evolutionary algorithm, to solve multiobjective...
Mechanical characterization of nickel plated copper heat spreaders with different catalytic activation surface treatment techniques
March 2013
This paper studied the effects of different catalytic activation processes towards intermetallic diffusion and mechanical properties on nickel plated heat spreader after high temperature storage (HTS). Heat spreader performs as medium to dissipate heat from silicon die towards heat-sink and is normally made by copper that is plated with nickel to improve wear resistance and prevent oxidation of copper. Two types of heat...
Utilization of paper sludge in clay bricks industry to obtain lightweight material: Evidence from partial replacement of feldspar by paper sludge
March 2013
In recent years, scientific issues related to environmental preservation have acquired great importance and the major challenge to be met is the recycling of materials discarded, causing various damages to the environment by technological development through a disposal of waste. This paper offers a possibility of recovery of waste and byproducts of paper manufacturing (paper sludge) and their use as an addition for...
Modification of some Albanian wood properties through chemical treatment
March 2013
A study was carried out to evaluate the influence of acetylation on physical properties and gluing ability of some Albanian woods. Three woods were studied: beech (Fagus sylvatica L.), poplar (Populus alba L.) and fir (Abies alba Mill.). For acetylation, pyridine and acetic anhydride were used. After treatment, all the samples were conditioned to 100% relative humidity of air and were measured...
Page 11 of 52, showing 50 records out of 2574 total, starting on record 501, ending on 550
Advertisement
Advertisement
