The effect of mercerization media on the physical properties of local plant bast fibres
November 2009
The effect of using different mercerization media on some mechanical properties of local plant bast fibres, Roselle (Hibiscus sabdariffa), kenaf (Hibiscus cannabinus), okra (Hibiscus esculentus), Baobab (Adansonia digitata) respectively, were generally investigated. The fibres from these sources were purified using the retting method which involved heating with 15% ammonium oxalate followed by scouring using 2% sodium...
Theoretical analysis of water distillation using solar still
November 2009
In developing countries, lack of safe and unreliable drinking water constitutes a major problem. To alleviate this problem, a solar still was designed and tested in Mubi, Adamawa State of Nigeria. The radiation from the sun evaporates water inside the solar still at a temperature higher than the ambient. The principle of operation is the greenhouse effect provided with the glass cover. Energy balances are made for each...
Electrical characteristics of (N2-H2) gas mixture DC glow discharge
November 2009
The electrical characteristics of DC Nitrogen-Hydrogen mixture glow discharge were investigated. The discharge current-voltage (I-V) characteristic curves of the discharge were measured at different gas pressures and gas mixture percentage. The axial distribution of both potential and electric field were studied at different H2percentage. The existence of the reversal electric field in the negative glow region was...
Determination of integrated absorption cross-section, oscillator strength and number density of caffeine in coffee beans by the integrated absorption coefficient technique
November 2009
The integrated absorption cross-section of caffeine in water and dichloromethane, in the wave number regions of 20,000 – 39,062 cm-1 at room temperature, were (4.44 ± 0.18) × 107 and (4.32 ± 0.11) × 107 L mol-1 cm-2, respectively. The corresponding calculated values for oscillator strength of caffeine in water and dichloromethane were 0.19...
Influence of hydrogen plasma on properties of transparent PEDT/PSS thin films
November 2009
Poly (3, 4-ethylene dioxy thiophene)/ poly (styrene sulfonic acid) conductive polymer was deposited on glass substrates through Dip-coating method. These films were subjected to hydrogen plasma in order to evaluate the probability of resistivity reduction. Their electro-optical behavior and structure were studied before and after this process. Hydrogenation at a substrate temperature of 80°C for 30 min reduced the...
On pre-service science teachers' preexisting knowledge levels about basic astronomy concepts
November 2009
A curriculum to train teacher candidates is a very important factor in developing teacher candidates’ conceptual understanding of scientific concepts. Teacher candidates have a dramatic impact on students’ ability to understand and construct new knowledge of the concepts. The purpose of this study was to determine the preconceptions and misconceptions of teacher candidates about basic astronomy concepts....
The polarization effects of the n-9Be neutron elastic scattering
November 2009
The differential cross section of the n-9Be neutron scattering and polarization effects is calculated in the framework of the eikonal approximation theory. In this paper by taking explicitly into account the composite quark structure of nucleons exchange effects we eliminate some discrepancies between the theory and the data that were recently pointed out. Key words: Neutron scattering,...
Enhancement of natural convection heat transfer from a fin by rectangular perforations with aspect ratio of two
October 2009
In this study, the enhancement of natural convection heat transfer from a horizontal rectangular fin embedded with rectangular perforations of aspect ratio of two has been examined using finite element technique. The results for perforated fin have been compared with its equivalent solid one. A parametric study for geometrical dimensions and thermal properties of the fin and the perforations was carried out. The study...
Intelligent fading memory for high maneuvering target tracking
October 2009
In this paper, a new fuzzy fading memory (FFM) is developed in order to aid a modified input estimation (MIE) technique and to enhance its performance in tracking high maneuvering targets. The MIE has been introduced recently and performs well in tracking low and medium maneuvering targets. However, this method does not represent desirable accuracy in tracking high maneuvering or jerking targets. In fact, this trouble...
Geotechnical and geophysical studies for wind energy systems in earthquake-prone areas: Bahce (Osmaniye, Turkey) case
October 2009
Wind energy structures are systems related to the conversion of wind energy into useful form by wind power. They are subjected to strong dynamic and static loads. For this reason, an integrated site/soil investigation is required for all phases of project. In this context, there are several geotechnical/geophysical criteria and requirements such as settlement criteria, stiffness requirements, ground water and dewatering...
CuIn (Se,S)2 based photovoltaic cells from one-step electrodeposition
October 2009
The formation of CuIn (Se,S)2 films for application in photovoltaic devices by post-deposition treatments of electrodeposited pre-cursors is described. The polycrystalline CuInSe2 (CIS) pre-cursor layers were prepared by the one-step electrodeposition (ED) method on molybdenum-coated soda lime (SL) glass substrates. Growth was performed from low concentration buffered baths containing CuSO4, In2(SO4)3 and...
Verified bounds for nonlinear systems via Hansen-Sengupta method
October 2009
Efficient numerical validation of solution to nonlinear systems of equations using the Hansen-Sengupta method is the main focus of our studies. An extremely fast method due to (Uwamusi, 2007) is used to accelerate basic characteristic convergence of the method. This is not surprising because the midpoints and radii of the convergent interval vectors obtained are coupled sequence via the inclusion isotonicity of interval...
The evolution of the molecules of deoxy-hemoglobin S in sickle cell anaemia: A mathematical prospective
October 2009
In this paper, the Langevin equation is used to solve hemoglobin aggregation in patients of sickle cell anaemia. The resulting second order nonlinear differential equation is solved to obtain a sigmoid deformation behavior. The deformation and the absorbance satisfy the Verhulst Model of the first order which is well-known in population dynamics. A time-dependent general expression is obtained for the coefficient of...
Dynamic analysis for acceleration of crab shell after explosion
October 2009
In this research, the study of dynamical aspect of the crab shell, using assumption such as energy conservation in the nebula system, exiting of hydrogen gas all around the nebula and time dependant acceleration of expansion is assessed. We could found a relation for the velocity of expansion by drawing the graph of velocity, the initial velocity of expansion is calculated to be v (0) = 196059...
Investigation of photon attenuation coefficient for pumice
October 2009
With the rapid development in technology, the radiation protection has become one of the most important part of building construction. As shielding is the basic method for radiation protection, besides the physical and mechanical properties of materials used in building construction, the radiation shielding properties should also be known. In this study, the linear attenuation coefficients of two different types of...
Geophysical evaluation and chemical analysis of kaolin clay deposit of Lakiri village, southwestern Nigeria
October 2009
A geophysical survey using the vertical electrical sounding (VES) technique was carried out to evaluate kaolin clay mineral deposit of Lakiri village, Obafemi-Owode local government area of Ogun State, Southwestern, Nigeria. Thirty three (33) Schlumberger vertical electrical soundings (VES) were acquired at three different sites. The data obtained was interpreted using WingGLink software to determine the apparent...
Investigation of groundwater resources in part of Ukwuani local government area of Delta State, Nigeria
October 2009
Vertical electrical sounding data were acquired from 12 locations evenly distributed around Obiaruku town and her environs. This is an attempt to obtain useful information on the aquifer distribution within the area and hence delineate possible depths boreholes could be drilled for portable and sustainable water supply. Based on the geoelectric section which is in agreement with the driller’s log, two near surface...
Roughing filter for water pre-treatment technology in developing countries: A review
September 2009
Roughing filtration can be considered as a major pre-treatment process for wastewater, since they efficiently separate fine solids particles over prolonged periods without addition of chemicals. This review article summarizes and evaluates modifications to roughing filtration technology, which may address these limitations without compromising the simplicity of the treatment process. Successful modifications includes...
Physical characterisation of some honey samples from North-Central Nigeria
September 2009
Some physicochemical properties (water content, sugar content, viscosity, pH and conductivity) were determined for honey samples from North-Central Nigeria to evaluate their global behaviour and comparison with other honey samples. The water content and sugar content varied within the range of (18.22 - 36.82%) and (63.82 - 80.25%) respectively. The pH increased with increase in water content and the...
Kinetics and mechanism of oxidation of sugar and sugar alcohols by KMnO4
September 2009
The kinetics of carbonate sugars and sugar alcohols by potassium permanganate in oxidation hydrogen / NaOH buffer have been investigated spectrophotometrically under pseudo-first order conditions and over a wide range of experimental conditions. Each reaction is first order with respect to the substrate and oxidant. The kinetic data for the oxidation by alkaline KMnO4 solution reveal that pseudo-first order rate...
Hydrogeological deductions from geoelectric survey in Uvwiamuge and Ekakpamre communities, Delta State, Nigeria
September 2009
The vertical electrical resistivity survey (VES) utilising the surface Schlumberger electrode array with a maximum current electrode spacing varying from 50 - 500 m has been used to provide valuable information on the hydrogeologic system of the aquifers and the subsurface lithology in Ekakpamre and Uvwiamuge communities. A total of twenty three (23) VES stations were sounded. Four to five...
Investigation of the effect of outlet pollutants of cement production industries around Tehran and approaches to control and eliminate pollutants
September 2009
Air pollution is one of the most serious environmental problems in Tehran. Each day, a tremendous amount of toxic and fatal gases, different kinds of pollutants, perilous floating particles produced by cars, factories, industrial workshops, power plants and residential buildings are added to the air. Largely due to the increasing demand for cement, cement production industries around Tehran have increased their daily...
A remark on the classifications of rhotrices as abstract structures
September 2009
This paper presents additional classifications of rhotrices as abstract structures of Ring, Field, Integral Domain, Principal Ideal Domain and Unique Factorization Domain, as a sort of an additional work to our earlier classifications of rhotrices as algebraic structures of Groups, Semi groups, Monoids and Boolean Algebra. Rhotrix is a new paradigm of matrix theory, concerned with representing arrays of real numbers in...
Application of molecular modeling with mass-spring systems for computer simulation and animation
September 2009
This paper demonstrates the use of potential functions of molecular modeling in mass-spring systems. In mass-spring systems, force acting on each mass point is determined by the spring length between linked mass-points. In molecular modeling, forces are calculated using bond length (spring length), bond angle and stretch-bond interactions. Molecular modeling therefore provides more accurate force function. Molecular...
Numerical simulation of nonlinear pulses propagation in a nonlinear optical directional coupler
September 2009
The concept of non-linear pulse is a symptom of such physical phenomenon inherently non linear, and its history is intimately linked to the development of theories of equations of nonlinear waves. As such, we now know that the non-linear pulses occur naturally in most nonlinear systems. This paper is devoted to modeling the evolution of nonlinear pulse during its propagation in a nonlinear directional coupler (NLDC) in...
Effect of cooling rate on hardness and microstructure of AISI 1020, AISI 1040 and AISI 1060 Steels
September 2009
The object of the present work is to investigate the effect of cooling rate on microstructure and mechanical properties of AISI 1020, AISI 1040 and AISI 1060 steels. The samples were heated and treated at 1250°K for 4 h and subsequently were cooled by three different methods. For this purpose, the microhardness and microstructure of these steels after heat treatment were examined by optical microscopy and hardness...
Time-lagged recurrent network for forecasting episodic event suspended sediment load in typhoon prone area
September 2009
Forecasting suspended sediment load is crucial for river water quality continuous management. This paper investigates the accuracy of a time-lagged recurrent network (TLRN) for forecasting suspended sediment load (SSL) occurring episodically during the storm events in Kaoping River basin located in Southern Taiwan. For this study, two major stations of Kaoping River basin; Liukwei and Lao-Nung are taken into account...
Antimalarial mixed ligand metal complexes: Synthesis, physicochemical and biological activities
September 2009
Complexation behaviour of mixed complexes of mefloquine hydrochloride and chloroquine phosphate (first-line antimalarial drugs) with Cobalt(II), Nickel(II) and Iron(III) were studied; the complexes were prepared using template methods, and chelates of 1:1:1 stoichiometries were formed. The nature of the bonding of the mixed ligands (mefloquine and chloroquine) and structure of the isolated metal complexes were proposed...
Comparative study of the effect of different pretreatment methods on biogas yield from water Hyacinth (Eichhornia Crassipes)
September 2009
A comparative study of the effect of different pre-treatment methods on the biogas yield from Water Hyacinth (WH) was carried out. The WH charged into metallic prototype digesters of 121 L capacity were pre-treated as: dried and chopped alone (WH-A), dried and treated with KOH (WH-T), dried and combined with cow dung (WH-C), while the fresh water Hyacinth (WH-F) served as control. They were all subjected to...
Chromium (III) sorption from aqueous solutions using activated carbon prepared from cashew nut shells
August 2009
Activated carbon prepared from cashew nut shells using potassium hydroxide activation at 850°C in N2 and CO2 atmosphere was used as an adsorbent for the removal of chromium ions from aqueous solutions. The adsorption of Cr(III) ions on activated carbon was studied. The effect of experimental parameters such as, pH of initial concentration of Cr(III) solutions, contact time, dosage of adsorbent and initial...
Ultrasound-assisted extraction flavonoids from Lotus (Nelumbo nuficera Gaertn) leaf and evaluation of its anti-fatigue activity
August 2009
In this study, flavonoids were obtained from Lotus (Nelumbo nuficera Gaertn) leaf using ultrasound-assisted extraction method (UAE). Optimum extraction conditions of flavonoids from Lotus leaf (FLL) were investigated through single factor test and orthogonal test. Its anti-fatigue activity was evaluated by swimming test. The results showed that the optimal extraction parameters were as followings: concentration of...
Equilibrium sorption isotherm for lead (Pb) ions on hydrogen peroxide modified rice hulls
August 2009
Modified rice hulls system for removing Pb (II) from aqueous solutions has been investigated. Rice hulls are agricultural waste product. The experimental condition was the modification of the rice hulls (sorbent) with different concentrations of hydrogen peroxide solution. The experimental results were fitted to the Langmuir and Freundlich isotherms to obtain the characteristic parameters of each model. The Langmuir...
Family of surface with a common null geodesic
August 2009
We analyzed the problem of finding a surfaces family through a null curve with Cartan frame. We constructed a differential equation system such that a given null curve is an isogeodesic curve on a surface. In addition, developablity along the common null geodesic of the members of surface family are discussed. The extension to ruled surfaces is also outlined. Finally, we demonstrated some interesting surfaces about...
A new priority sequence rule for the theoretical determination of products of explosion reactions
August 2009
A new priority sequence rule for the theoretical prediction of products of explosion reactions is derived from the standard enthalpies of formation of the products using the gaseous states of the relevant elements. The standard enthalpies were calculated and arranged in increasing order to form a priority sequence rule of products in the order H2O, CO, CO2, based on the fact that a compound with lower enthalpy is more...
Theoretical studies of the effect of Ti, Zr and Hf substitutions on the electronic properties of alpha-alumina
August 2009
We have investigated the electronic properties of pure Alpha-Alumina (sapphire phase) and the aluminates α-Al2-xTxO3 where T is a transition metal and stands for Ti, Zr and Hf with x = 0.5. In this study we have employed the full potential linear augmented plane wave (FPLAPW) with Generalized Gradient Approximations (GGA) based on the Density Functional Theory (DFT) as implemented in WIEN2K code. The result shows...
Application of geophysical and geotechnical investigations in engineering site evaluation
August 2009
Geophysical and geotechnical studies were conducted at a proposed Switch station facility for Telecommunication at a site in the south-eastern part of Nigeria. The aim of the study is to evaluate the sub-soil conditions and electrical properties of the soil which may have effect on the proposed mast and switch facilities system. The geophysical investigation involved the Vertical Electrical Sounding (VES) technique...
Simulation of spatial and energy resolution in signal for gas proportional detector
July 2009
Computer simulations of charge transport and signal generation mechanism have been performed for the Aleph Inner Tracking Detector geometry. A number of factors influence the signal arising from the charge carriers generated within detector volume. In the present simulation, signal fluctuations due to changing of incident charged particle energy and position of the primary generated electron-ion pairs in the gas volume...
Properties of the U>>t 2-electrons in two dimensions using the hubbard model
July 2009
We examine the behaviour of 2 electrons on a 2 x 2 square lattice sites. The Hubbard model was used to model the system and was diagonalized using the configuration interaction method which is a variational method. The variations of the ground state energy ground state double occupied sites D, and the ground state kinetic energy with the interaction strength (u < 0 and u > 0) were examined....
Biogas production from blends of cassava (Manihot utilissima) peels with some animal wastes
July 2009
Cassava peels (CP) obtained after peeling cassava roots were anaerobically digested using 50L capacity fermentor and in blends with some animal wastes. The peels were blended with cow dung (CD), poultry droppings (PD) and swine dung (SD), in the ratio of 1:1. The mean flammable biogas yield of the cassava peels alone was 2.29 ± 0.97L /total mass of slurry. When blended with CD, PD and SD, mean flammable biogas...
Natural radioactivity of coals and its risk assessment
July 2009
Burning of the coal that occur around coal-fired power plants and also in many of the habitance during the winter season may affect human health as it contains natural radionuclides. In this study, the radioactivity of the different types of coal samples used in Turkey has been determined using a ï§-ray spectrometer which consists of a NaI (Tl) detector connected MCA, and possible health effect were estimated. The...
Hydrogenation impairs the hypolipidemic and antioxidant effects of palm oil in rats
July 2009
The effect of hydrogenated palm oil on lipid profiles and on activities of selected glutathione-dependent enzymes in rats was investigated. Male albino wistar rats were randomly divided into 2 groups, fed on fresh palm oil (control) and hydrogenated palm oil (HPO) supplemented (5% by weight) diets respectively for 10 weeks. Serum cholesterol, liver lipid peroxidation and daily excretion of triacyl glycerol (TAG) and...
Correlation between electrical resistivity and soil-water content: Istanbul and Golcuk
June 2009
Soil is a heterogeneous medium which consist of liquid, solid, and gaseous phases. The solid and liquid phases play an essential role in soil spontaneous electrical phenomena and in behavior of electrical fields, artificially created in soil. Soil air can be considered as a dielectric. Soil electrical properties are the parameters of natural and artificially created electrical fields in soils and influenced by...
Air pollution tolerance indices (APTI) of some plants around Erhoike-Kokori oil exploration site of Delta State, Nigeria
June 2009
The study examined air pollution tolerance indices (APTI) of ten plant species around the Erhoike-Kokori oil exploration station of Delta state. Four physiological and biochemical parameters; leaf relative water content (RWC) ascorbic acid content (AA), total leaf chlorophyll (TCh) and leaf extract pH were used to compute the APTI values. The result showed that combining variety of these parameters gave a more reliable...
Derivation of statistical models to predict roughness parameters during machining process of PEEK composites using PCD and K10 tools
June 2009
In many scientific fields, non-linear regression based models are of great utility to perform curve adjustment of experimental data. This concept is used in the present study in order to construct adequate adjusted models enabling to make predictions for the different roughness parameters characterizing machining of PEEK composites when using PCD and K10 tools. The adjusted data were obtained by using design of...
Solar assisted photo-catalytic degradation of amido black 10B over cobalt, nickel and zinc metalloporphyrins
June 2009
The tetraphenyl porphyrins (TPP) and metalloporphyrins such as CoTPP, NiTPP and ZnTPP were synthesized, purified and characterized by UV-Visible spectroscopy, IR spectroscopy, 1H NMR spectroscopy and elemental analysis. The results have been discussed in the light of magnetic susceptibility; diffuse reflectance spectroscopy (DRS), electron spin resonance (ESR), X-ray diffraction data and solar assisted...
The analytical and numerical investigation of thermo-optic effects in double-end-pumped solid state lasers
June 2009
In this paper, thermal effects in double-end pumped Nd:YVO4 laser crystal have been investigated. The analytical expression for temperature distribution and thermo-optic effects such as temperature-dependent change of refractive index (dn/dT effect) and end effect have been calculated and the results then applied to Nd:YVO4 crystal., Our analytical model compared with exact numerical calculations and good...
The dynamical effect of stark-shifts produced from a four-level atomic system
May 2009
We consider a two-mode quantized field described in a coherent state interacting with a four-level atom. An effective Hamiltonian is obtained by adiabatically eliminating the intermediate two levels in a cascade process. The influence of the Stark shifts on the atomic inversion is examined, as well as on the second order auto-correlation function and on the cross-correlation between the field modes. The results of the...
On Mannheim partner curves in E3
May 2009
The aim of this paper is to study the Mannheim partner curves in Euclidean space E3. We obtain the relationships between the curvatures and the torsions of the Mannheim partner curves with respect to each other. Key words: Mannheim partner curves, curvature, torsion.
Blind signal separation using an adaptive weibull distribution
May 2009
We propose an independent component analysis (ICA) algorithm which can separate mixtures of sub- and super- Gaussian source signals with self-adaptive nonlinearities. The ICA algorithem in the framework of natural Riemannian gradient is derived using the parameterized Weibull density model. The nonlinear function in ICA algorithem is self-adaptive and is controlled by the shape parameter of Weibull density model....
The seasonal variation of ph and dissolved oxygen (dO2) concentration in Asa lake Ilorin, Nigeria
May 2009
The vertical and surface water variations of pH and dissolve oxygen (DO2) concentration were studied for 12 months (March 2005 to February 2006) in Asa lake Ilorin, Nigeria. The mean surface pH values ranged between 7.30 and 8.10, with lower values (7.30 - 7.70) obtained October to December while higher values (8.0/8.10) were obtained in January to July. Vertical distribution of mean pH also ranged from 8.1 (Surface) to...
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