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...
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...
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...
Gamma-ray shielding of concretes including magnetite in different rate
February 2013
The effect of magnetite ore rate on the gamma radiation shielding properties of concrete samples have been measured by using the transmission method for 59.54 and 80.99 keV gamma rays with a NaI(Tl) detector. Linear attenuation coefficients of concrete samples including magnetite in different rates were obtained by Lambert law in which measured gamma ray intensities were used. They were compared with theoretical values...
Effects of growth rate on the physical and mechanical properties of Sn-3.7Ag-0.9Zn eutectic alloy
February 2013
Sn-3.7wt.%Ag-0.9wt.%Zn alloy was directionally solidified upward under different conditions, with different growth rates (V = 3.38 - 220.12 µm/s) at a constant temperature gradient (G = 4.33 K/mm) and with different temperature gradients (G = 4.33 -12.41 K/mm) at a constant growth rate (V = 11.52 µm/s) by using a Bridgman-type directional solidification furnace. The microstructure was observed to be a rod...
Improvement of electromagnetic wave (EMW) shielding through inclusion of electrolytic manganese dioxide in cement and tile-based composites with application for indoor wireless communication systems
February 2013
The electromagnetic wave absorption characteristics of composite cement-based building material have attracted much interest in recent times. Researchers have mainly focused on the 2 GHz to 12 GHz frequency range while the authors have investigated the mobile and WiFi frequency bands. The determination of characteristics such as reflection loss, absorption, attenuation and shielding effectiveness are crucial in the...
The impact of plasma interference profile (PIP) on argon discharge in plasma focus device
February 2013
Radiation emission in a low energy (2.2 kJ, 12 kV) UM plasma focus is studied. The system is operated in Argon filling gas. Enrichment of the radiation emission yield is obtained with an optimized pressure 1.7 mbar. Time resolved radiation emission measurements are made by using an array of PIN diode detectors covered with few Al foil thicknesses, to be found at top arrangement at distance 43.50 cm from the...
Aftershock sequence analysis of 19 May, 2009 earthquake of Lunayyir lava flow, northwest Saudi Arabia
February 2013
Aftershock sequence of 19th May, 2009 Lunayyir earthquake (Mw 5.7) has been recorded by deploying seismic stations immediately after the occurrence of the main shock. Analysis of this sequence clarified that; the major part of cumulative seismic moment released during the first hours after the occurrence of the main shock; their orientation is north west (NW) parallel to the Red Sea axial trend along Najd faulting...
Determination of the crust-mantle electrical conductivity-depth structure of Niger Delta using solar quiet day (Sq) current
February 2013
Innovative attempt has been made to study the crust-mantle electrical conductivity-depth structure of the Niger Delta region in Nigeria by applying solar quiet (Sq) day current. The study involved the use of geomagnetic data obtained from Lagos by magnetic data set (MAGDAS), Japan in 2010. Gauss spherical harmonic analysis (SHA) technique was employed which separated the internal and external field contributions to Sq...
Effect of geometric parameters on free vibration analysis of thick fiber reinforced plastic (FRP) skew cross-ply laminate with circular cutout
February 2013
The present investigation deals with the free vibration analysis of a thick four-layered symmetric cross-ply skew laminated composite plate with a circular cutout and clamped boundary conditions. Three dimensional finite element models (FEMs) which use the elasticity theory for the determination of stiffness matrices are modeled in ANSYS software to evaluate first five natural frequencies of the laminate. The variations...
Transient mass transfer flow past an impulsively started infinite vertical plate with ramped plate velocity and ramped temperature
February 2013
An exact solution to the problem of a transient free convective mass transfer flow of a Newtonian non-Grey optically thin fluid past a suddenly started infinite vertical plate embedded in a porous medium with ramped wall temperature as well as ramped plate velocity in presence of appreciable thermal radiation and first-order chemical reaction is presented. The resulting system of equations governing the flow is solved...
A novel technique for solving Cauchy problem for the third-order linear dispersive partial differential equation
February 2013
To solve Cauchy problem for the third-order linear dispersive partial differential equation, the reduced differential transform (RDT) method is used. Without using any discretization or perturbation the technique gives analytical approximation in the form of rapidly convergent sequence with well-structured terms that can usually be expressed in a compact form. The efficiency and reliability of the method is demonstrated...
Heavy metal removal by ambient-temperature argon plasma modified polyethylene terephthalate (PET) fibers with surface acrylic acid grafting
February 2013
This study utilized the capability of ambient-temperature plasma in modifying the surface properties of materials to activate the nonwoven polyethylene terephthalate (PET) fiber surfaces. The effects of different plasma treatment parameters (such as plasma power, treatment time) and grafting parameters (such as grafting temperature, acrylic acid monomer concentration, grafting time) on the activation and grafting of the...
Interface energy of solid cadmium (Cd) phase in the Cd-Pb (Cadmium-Lead) binary alloy
February 2013
The grain boundary groove shapes for the Cadmium (Cd) phase in equilibrium with the Lead (Pb)-Cd eutectic liquid were obtained with radial heat flow apparatus. From the obtained grain boundary groove shapes, the Gibbs-Thomson coefficient, solid-liquid and grain boundary energy for the Cd phase in equilibrium with the Pb-Cd eutectic liquid were determined to be (8.35 ± 0.41) x 10-8 Km, (128.00 ± 12.8)...
Optimal sensor placement for fault detection and isolation by the structural adjacency matrix
February 2013
In this paper, we consider the optimal sensors placement problem for faults detection and isolation. When the detection and isolation of faults of an existing system’s sensors is impossible or uncertain, a reconfiguration sensor placement of this system should be reconsidered. The propagation of faults (Observability/Detectability) was studied in a structured linear system on a directed graph (digraph). An...
Performance analysis of ultra wideband media access control protocol providing two class traffic
February 2013
Ultra wideband (UWB) technology based primarily on the impulse radio paradigm has a huge potential for revolutionizing the world of digital communications especially wireless communications. Multiple packets can be assembled into a single frame at the medium access control (MAC) layer, which can significantly improve the throughput performance. This paper presents a detailed performance analysis for UWB multi-band MAC...
A comment on “Robust linear optimization under new distance measureâ€
February 2013
Zhang et al. (2012) proposed a new robust counterpart for linear optimization, and shown the effectiveness of the new model by numerical results of AFIRO and ADLITTLE. In this comment, it is shown that the numerical results in their paper are not true, conversely, the model of Bertimas and Sim (2004) has better optimality than that of Zhang et al. (2012) if the same probability bounds that the -th constraint...
Derivation of the spatially flat Friedmann equation from Bohm-De Broglie interpretation in canonical quantum cosmology
February 2013
Friedmann equations play a central role in cosmology for describing the evolution of the universe. Initially, the Friedmann equations were derived by Alexander Friedmann in 1922. He derived the equations from Einstein’s field equations for a universe which is spatially homogeneous and isotropic. The equations were again derived from Newtonian mechanics by Milne. However in this paper, we derive the spatially flat...
Comparative study of four methods for estimating Weibull parameters for Halabja, Iraq
February 2013
The Weibull distribution is the standard function used by the wind energy community to model the wind speed frequency distribution. In this study, four methods are presented for estimating Weibull parameters (Shape and Scale), namely, Maximum likelihood method (MLM), Rank regression method (RRM), Mean-standard deviation method (MSD), and Power density method (PDM). To compare the methods, a period of 4 years (2001 -...
The effects of cow dung inoculum and palm head ash-solution treatment on biogas yield of bagasse
February 2013
Blends of ash solution and water-soaked bagasse with cow dung inoculum were studied for biogas production. Two sets of five biodigesters each of 50 kg capacity were used. The blends were respectively charged into the 50 kg metal prototype biodigesters in the ratio of 3:1 (water:waste). Proximate analyses as well as total solids, volatile solids, carbon content, and calorific value were conducted on the wastes while...
Econometric modeling and projection of production, import and export of particle board industry in Turkey
February 2013
Although wood is one of the oldest materials used by humans, the production of wood-based panel products has a very short history. The production of panel products constitutes one of the most important developments in forest products industry. In this study, models are established and projections are developed for production, import and export of Turkish Particle board industry by econometric method. As a result of...
Probing of dielectric properties of high density poly-ethylene/calcium carbonate (HDPE/CaCO3) nano-micro composite
January 2013
In this experimental investigation, high density poly-ethylene/calcium carbonate (HDPE-CaCO3) micro/nano composite sheets were prepared by melt blending the master batch using twin screw extruder followed by injection molding. The dispersion characteristics were determined by field emission scanning electron microscope (FESEM) and were found to be reasonably uniform. These sheets were then subjected to electrical...
Adjust of energy with compactly supported orthogonal wavelet for steganographic algorithms using the scaling function
January 2013
When RGB images are processed for the implementation of steganographic algorithms, it is important to study the quality of the cover and retrieved images, since it typically used digital filters, reaching visibly deformed images. The discrete wavelet transform is useful for adjusting the stego- image quality, because one of their principal qualities which are able to analyze different frequency levels (multi-resolution...
Studies on mass attenuation coefficient, effective atomic number and electron density of some amino acids
January 2013
Mass attenuation coefficient (), effective atomic number () and effective electron density () were determined experimentally and theoretically for some amino acids (Glycine, L-Alanine, D-Alanine, Proline, L-Leucine and D-Leucine) at 8.04, 8.91, 13.37, 14.97, 17.44, 19.63, 22.10, 24.90, 30.82, 32.06, 35.40, 36.39, 37.26, 43.74, 44.48, 50.38, 51.70, 53.16, 80.99, 276.40, 302.85, 356.01, 383.85 and 661.66 keV photon...
Comparison of the performance of analog and digital hadronic sampling calorimeters
January 2013
By using the tungsten as passive element and the Glass Resistive Plate Chambers (GRPCs) as active element, the gaseous hadronic calorimeter is studied as a possible detector for the future International Linear Collider (ILC). The results of the numerical study, using the GEANT4 simulation package, of the performance of this calorimeter when it is exposed to a negative pion beam in an energy range from 5 GeV to 100 GeV...
Heavy metals in street soil dusts of industrial market in Enugu, South East, Nigeria
January 2013
Analysis of some heavy metals present in soil dusts of Industrial Market in Enugu, South East Nigeria was carried out. Soil dust samples were collected from five different sections in the market and a control sample was collected 500 m away from the market. The samples were analyzed after aqua regia digestion with Flame Atomic Absorption Spectrophotometer for Lead, Iron, Nickel, Copper and Cadmium. The result showed a...
Experimental study of the elastic multiple scattering by a two-dimensional (2D) periodic array in the case of empty cavities
January 2013
In this work, we study the propagation of the plane waves in a solid medium (Aluminium) which contains a periodic two-dimensional (2D) array of cylindrical inclusions using a multiple scattering theory. The aim of this study is to validate the experience of certain theoretical predictions such as the frequential positions of the stop-bands and their widths like their evolution according to the geometrical...
The modified (G'/G)-expansion method for the (1+1) Hirota-Ramani and (2+1) breaking soliton equation
January 2013
In this article, we apply the modified (G'/G)-expansion method to construct hyperbolic, trigonometric and rational function solutions of nonlinear evolution equations. This method can be thought of as the generalization of the (G'/G)-expansion method given recently by Wang et al. (2008). To illustrate the validity and advantages of this method, the (1+1)-dimensional Hirota-Ramani equation and the...
Fourier transform infrared spectroscopic characterization of clay minerals from rocks of Lalibela churches, Ethiopia
January 2013
This study demonstrates the Fourier transform infrared (FTIR), Raman spectroscopy andscanning electron microscope - energy dispersive X-ray spectrometer (SEM-EDS) techniques which has been applied to characterize decay products and processes occurring at the surface of rock-hewn churches at the UNESCO’s World Heritage site of Lalibela, Northern Ethiopia. Spectroscopic analyses comparing the observed...
Measurement of Kβ/Kα x-ray intensity ratios and K to L shell total vacancy transfer probabilities for elements in the range 40 ≤ Z ≤ 50
January 2013
The K shell x-ray intensity ratios Kβ/Kα for 9 elements in the atomic range 40 ≤ Z ≤ 50 have been determined for an excitation energy of 59.537 keV. The K-L total vacancy transfer probabilities (ηKL) for these elements have been determined, also. K x-rays emitted by samples were detected using a high resolution Si(Li) semiconductor detector. The measured...
Simultaneous ultraviolet-visible (UV–VIS) spectrophotometric quantitative determination of Pb, Hg, Cd, As and Ni ions in aqueous solutions using cyanidin as a chromogenic reagent
January 2013
The use of cyanidin (3, 31 41 5, 7 – pentahydroxyflavylium chloride) extracted from a tropical plant Hibiscus sabradiffa L. as a chelating reagent for simultaneous spectrophotometric determinations of ions of Pb, Hg, Cd, As and Ni in mixed aqueous solution is reported. The purified extract of the dried calyces of the Roselle plant was characterized and the results compared with literature...
Application of Cyanex® extractant in Cobalt/Nickel separation process by solvent extraction
January 2013
This study presents a detailed review on the advanced hydrometallurgical treatment involving the extraction and separation of Cobalt (Co) and Nickel (Ni) by Cyanex® extractants. The structures, properties and applications of various Cyanex® extractants such as Cyanex®272, Cyanex®301, Cyanex®921, Cyanex®923 and Cyanex®421X were discussed and compared. Cyanex®272 thus proved to be the most...
Twenty-five years of wind data in south-eastern locations of Nigeria: Modeling and prediction of wind potential
January 2013
Weibull distribution is often invoked to interpret and predict wind characteristics needed for effective design of wind power systems for different locations. In this paper, daily average wind data for Enugu (6.4°N; 7.5°E), Onitsha (6.8°N; 6.1°E) and Owerri (5.5°N; 7.0°E) over a 25-year period is modeled in terms of the Weibull distribution in order to accurately predict wind potentials for the...
Mechanical properties of Rowan wood impregnated with various chemical materials
January 2013
The aim of this research was to determine some of the mechanical properties of Rowan wood impregnated with various impregnation materials. For this purpose, the test samples were prepared from Rowan (Sorbus aucuparia Lipsky) wood materials that are of common use in the forest products industry of Turkey according to TS 345. The test samples were treated with Tanalith-E, Vacsol Azure, Imersol-Aqua, and Boron...
Digital in-line holography for blood cell
January 2013
This paper investigates the application of Fresnel based numerical algorithms for the reconstruction of Gabor in-line holograms. A simple in-line digital holographic system was used to record blood cell. The Fresnel transformation (FS) method was used for reconstruction of the hologram. High contrast blood cell images were used to demonstrate numerical reconstruction process by Matlab. Sine, cosin, and amplitude...
Double soliton solutions for some nonlinear partial differential equations (PDEs) in mathematical physics
January 2013
In this article, the extended coupled sub-equations expansion method was used to construct a series of double soliton-like solutions, double triangular function solitons and complexiton solitons for some nonlinear partial differential equations (NLPDEs) via the (2+1)-dimensional breaking soliton equations and the (2+1)-dimensional Nizhnik-Novikov-Vesselov equations. With the help of symbolic computation as...
On the behavior of the solutions of the system of rational difference equations
January 2013
There has been a great interest in studying difference equations and systems. One of the reasons for this is a necessity for some techniques which can be used in investigating equations arising in mathematical models describing real life situations in population biology, geometry, economics, probability theory, genetics, physics etc. In this paper, we investigate the solutions of the system of rational difference...
Introducing mole fraction in the density calculations of liquid-liquid solutions
January 2013
The densities of an ideal and a non-ideal liquid-liquid solution were determined experimentally. The experimental results were then compared to calculated values using two mathematical expressions for density, employing partial densities in one and mole fraction in the other. Results were presented in form of tables and graphs, indicating the validity of applying mole fractions in the estimation of liquid-liquid...
Structural, mechanical, optical and second harmonic generation (SHG) studies of gamma glycine single crystal
January 2013
Single crystals of γ-glycine were grown by submerged seed solution method, hanging seed solution growth method and solvent evaporation method. Powder X-ray diffraction (XRD) studies were carried out to confirm the crystalline gamma phase and to find out the lattice parameters of the grown crystals. The presence of various functional groups was determined by Fourier transform infrared (FTIR) spectroscopic analysis....
Synthesis and crystal structure of (Nitrato-O, O')-bis(triphenylphosphine)-silver(I) toluene mono-solvate
January 2013
The reaction of Ag(I) nitrate with triphenylphosphine in methanol in 1:1 molar ratios and recrystallization in toluene resulted in complex of the formula [Ag(PPh3)2NO3]∙C7H8. The compound is a mononuclear neutral complex in which the Ag atom is in a tetrahedral environment consisting of two triphenylphosphine ligands and a nitrate ion acting as a bidentate ligand. The compound crystallizes in the triclinic P`1 space...
Dye-sensitized solar cells (DSSCs) based on poly(3-hexylthioacetate thiophene)
January 2013
This work details the synthesis of a functionalized all-donor polymer, poly(3-hexylthioacetate thiophene) (P3HTT). The spectrophotometry analysis of the polymer showed absorption bands at 450 and 536 nm in the liquid and solid states, respectively with optical band gap ( QUOTE ) of 1.9 eV. In addition, the polymer emits in the green region of the emission spectrum with photoluminescence (PL)...
Removal of 2-Nitrophenol by Linde Type A (LTA) zeolites
January 2013
The adsorption of 2-nitrophenol on zeolites 3A (KA) and 5A (CaA), the general name of which is Linde Type A (LTA), have been investigated by using fourier transform infrared (FT-IR) spectroscopy and scanning electron microscope (SEM) analysis. Nitrophenols can be regarded as both occupational and environmental pollutants. In this work, LTA zeolites which are commercially suitable media for environmental pollutants are...
Timelike tubes with Darboux frame in Minkowski 3-space
January 2013
In this study, we define a timelike tube around a spacelike curve with timelike binormal by taking Darboux frame instead of Frenet frame in Minkowski 3-space QUOTE . Subsequently, we compute the Gaussian curvature, the mean curvature, and the second Gaussian curvature of timelike tube with Darboux frame and obtained some characterizations for special curves on this timelike tube around a spacelike...
Evaluation of groundwater potential and aquifer protective capacity assessment at Tutugbua-Olugboyega area, off Ondo road, Akure Southwestern Nigeria
January 2013
A total of thirty-two (32) vertical electrical sounding (VES) data were acquired using R 50 d.c. Resistivity meter within the Precambrian basement geology of part of Akure metropolis southwestern Nigeria. The VES data were interpreted; eight type curves were identified, from the geoelectric section the subsurface was characterized into four lithologies namely topsoil, weathered layer (clay /lateritic clay),...
Experimental approach to mechanical properties of natural rubber mixing with Calcium carbonate powder
December 2012
Mechanical properties of natural rubber (NR) and calcium carbonate as additive filler with amounts of 5, 10, 15, 20, and 25 parts per hundred (pphr) were studied. The influence of calcium carbonate content on hardness and tensile strength of NR were investigated. The results were obtained from the tests shown. NR hardness and tensile strength was enhanced after adding calcium carbonate powder and...
Study of performance of CeO2/ZnO nanocatalysts for the oxidative coupling of methane using carbon dioxide as oxidant
December 2012
This study shows how CeO2/ZnO nanocatalysts were prepared by combining homogeneous precipitation with micro emulsion using a conventional heating technique. The catalysts were then used in a conventional fixed bed reactor for the oxidative coupling of methane using carbon dioxide as an oxidant. Catalyst performance tests were carried out at atmospheric pressure, feed gas of 33 and 45 ml/min, and reaction temperatures...
Landslide investigation study using seismic refraction and 2D electrical resistivity imaging (ERI) technique in Ooty, Nilgiri District, Tamilnadu
December 2012
The aim of this paper is to investigate landslide prone areas in Nilgiri hills which have caused damage to people and properties and to devise preventive steps to be taken in the events of future landslides. Our study area was situated at Ooty region, Nilgiri District, Tamilnadu. In this study we use the seismic refraction survey carried out across landslides located near the villages in Allanchi, Kundha, The...
Estimation of aquifer characteristics using vertical electrical soundings (VES) data from Enugu State University of Science and Technology, Agbani, Nigeria
December 2012
Vertical electrical soundings (VES) were carried out in order to determine the groundwater potential of the Enugu State University of Science and Technology, Agbani, Nigeria. The instrument used was the ABEM Terrameter SAS 300B, employing the Schlumberger electrode configuration. Interpretation of the VES data by partial curve matching technique aided by computer modeling showed that the sampled earth subsurface can be...
Suicide incidents in India in relation with solar activity parameters and cosmic ray intensity (1989 to 2011)
December 2012
We studied the relation between the death due to suicide in India and of various solar activity (SA) parameters, for example, sunspot numbers (SSN), solar flare index (SFI), coronal index (CI) and cosmic ray intensity (CRI), observed during the period of 1989 to 2011. It is seen that the number of suicide incidents of male, female, and average is well correlated with yearly average of SSN, SFI, and CI and positively...
Effect of gate electrode work function in conventional and junctionless FinFETs
December 2012
This paper investigates the effect of gate electrode work function in 30 nm gate length conventional and junctionless FinFETs using technology computer-aided design (TCAD)simulations. DC parameters, threshold voltage (vt), drive current (Ion) and output resistance (Ro), and RF parameters, unity gain cut-off frequency (ft), non-quasi static (NQS) delay and input impedance (Z11) are investigated. Junctionless...
Page 12 of 52, showing 50 records out of 2577 total, starting on record 551, ending on 600
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