Hydrogeophysical investigation of groundwater potential in Emu kingdom, Ndokwa land of Delta State, Nigeria
May 2009
A study of 10 vertical electrical soundings from different quarters of Emu kingdom using Schlumberger array were undertaken. This is an attempt to obtain useful information on the aquifer distribution within the area and hence delineate possible site boreholes could be drilled for potable and sustainable water supply. Based on the geoelectric section which is in agreement with the driller’s log, the best...
Transfer of natural radionuclides from soil to plants in tropical forest (Western Ghats – India)
May 2009
Soil and 2 wild plant species (Evodia roxburghiana and Eleaocarpus oblangus)have been collected from the western Ghats region and analysed for 210Po and238U. The radioactivity concentrations in plants and soil reflect the impact of the existence of igneous nature of rock in the area of study. Concentration ratios (CR) of these radionuclides, between plants and underlying soil, have been studied and...
Topography measurement of nano silicon oxide film
May 2009
The Si (111) – 7 x 7 is a semimetal which its surface morphology has been normally studied with using STM (scanning tunneling microscopy) technique, whilst the other kind of silicon, such as Si(100) – 2 x 1 is not a semimetal. For letter surface structure, the AFM (atomic force microscopy) technique can be used as well. There are two main issues which are threatening the use of STM technique as a good...
Regulation of the electric power provided by the panels of the photovoltaic systems
May 2009
In this paper we analyzed in Pspice the influences of the solar radiation and the temperature on the optimal operation of the photovoltaic (PV) panels and the PV systems provided with an MPPT command (CFV) which fixes a voltage (Vopt) at output of PV panel. We have shown that the Vopt voltage depends on the seasons and function of the temperature. Between winter and summer the variation can reach 1V. This variation...
Analytical study of electromagnetic wave scattering behaviour using Lippmann-Schwinger equation
May 2009
An analytical study of electromagnetic wave scattering using Lippmann-Schwinger equation is presented in this work. Lippomann-Schwinger equation was derived first from hamiltonian that involves non-interacting and interacting terms. The solution for non-interacting and out going scattered waves was obtained using a boundary conditions specified on the green’s function which specifically handles the...
Influence of temperature on charge transports and optical parameters for the Ge15Sb5Se80 and Ge15Sb5Te80 amorphous thin films
May 2009
The thin films of chemical composition Ge15Sb5Se80 and Ge15Sb5Te80 were prepared by a thermal evaporation technique. Both the absorbance and the transmittance spectra were measured over the incident photon energy ranges 1.14 to 2.7 and 1.22 to 2.87 eV for the Ge15Sb5Se80 and Ge15Sb5Te80 films respectively. These were used for estimating the reflectance spectra in the same range of the incident photon...
Use of finite element method as a simulation technique for bioremediation of naphthalene, anthracene and pyrene contaminated soil in a fixed bed reactor
May 2009
In this work, the finite element method was applied to solve one-dimensional advective-dispersive solute transport model with linear equilibrium sorption and first-order degradation. This mathematical approach was adopted to adequately predict the effluent concentrations and breakthrough profiles of naphthalene, anthracene and pyrene. Simulation results showed that the concentrations of naphthalene, anthracene and...
Evaluation of some physicochemical parameters of selected brands of vegetable oils sold in Ilorin metropolis
May 2009
Five samples of selected brands of vegetable oils sold in Ilorin metropolis were investigated for some physicochemical parameters. Relative density, flash point, smoke point, crackle test, cold test and viscosity were determined for each sample. Also, the saponification, acids, ester and iodine values, as well as the fatty acid profile for each sample were investigated. Viscosity of the different brands of oils at...
Foundry properties of sand cores bonded with composites of Nigerian grades 1 and 2 acacia species with bentonite clay
May 2009
The permeability, green compressive and tensile strength of foundry cores bonded with composite mixtures of bentonite clay with each of grades 1 and 2 Nigerian acacia exudates were determined. Silica sand grains were used as base for the specimens which in accordance with foundry standard were cylindrically shaped for green permeability and compressive strength but shaped like figure eight for tensile strength test. A...
Elastic-plastic transition stresses in an isotropic disc having variable thickness subjected to internal pressure
May 2009
Elastic-plastic transitional stresses in an isotropic disc having variable thickness under internal pressure have been derived by using Seth’s transition theory. The effect of stresses in fully-plastic state for different values of k presented graphically and discussed. Disc made of compressible material and having variable thickness yields at some radius R1 at a higher pressure as compare to disc made of...
Enhancing road monitoring and safety through the use of geospatial technology
May 2009
The geographic information system (GIS) and the global positioning system (GPS) are the 2 geospatial technologies that are being used in monitoring of transportation generally. Transportation is a requirement for every nation regardless of its industrial capacity, political stability, population, size or technological development. Moving goods and people from one place to another is crucial to maintaining strong...
Spermatotoxic impact of bonny light crude oil (BLCO) ingestion on adult male Swiss albino mice
May 2009
Five samples of selected brands of vegetable oils sold in Ilorin metropolis were investigated for some physicochemical parameters. Relative density, flash point, smoke point, crackle test, cold test and viscosity were determined for each sample. Also, the saponification, acids, ester and iodine values, as well as the fatty acid profile for each sample were investigated. Viscosity of the different brands of oils at...
Numerical experiment on hygro-thermal deformation of concrete with different material or structural parameters
May 2009
Temperature and moisture are responsible for the deterioration processes of concrete structures, and the extensive failures in concrete elements often result from both thermal and moisture simultaneously. The influences of hygro-thermal physical parameters and structural parameters on the deformation of concrete were investigated numerically using a specially developed software, which is named Coupling...
Estimated optimization parameters of arrayed waveguide grating (AWG) for C-band applications
April 2009
In the present paper, we will investigate theoretically the basic design parameters of silica-based arrayed waveguide grating (AWG) in the C-band’s spectral range (from 1.528 to 1.56 μm). We have demonstrated theoretically that the minimum the diffraction order m, the maximum the number of the input/output wavelength channels, and the maximum the number of the arrayed waveguides. Also, we have investigated the...
Comparative study of microwave assisted and conventional synthesis of novel 2-quinoxalinone-3-hydrazone derivatives and its spectroscopic properties
April 2009
A series of novel quinoxalin-2(1H)-one-3-hydrazone derivatives, 2a - 8d were synthesized via condensation of 3-hydrazinoquinoxalin-2(1H)-one, 1, with the corresponding ketones under microwave irradiation. The microwave assisted reaction was remarkably successful and gave hydrazones in higher yield at less reaction time compared to conventional heating method. The chemical structures of the compounds prepared were...
Inhibitive and adsorption properties of ethanol extract of Colocasia esculenta leaves for the corrosion of mild steel in H2SO4
April 2009
Inhibitive and adsorption properties of ethanol extract of Colocasia esculenta for the corrosion of mild steel in H2SO4 were investigated using weight loss, hydrogen evolution and IR methods of monitoring corrosion. The results obtained indicates that ethanol extract of C. esculenta is a good inhibitor for the corrosion of mild steel in H2SO4 and its inhibitive action is attributed to its...
Equilibrium, kinetic and thermodynamic studies on the adsorption of phenol onto activated phosphate rock
April 2009
Phosphate rock being locally abundant and cheap material in Jordan can be easily activated to become a promising adsorbent for phenol removal from aqueous solution. The phosphate rock before and after activation was characterized using XRD and IR techniques. The effects of various experimental parameters, such as initial phenol concentration, temperature, pH, contact time and adsorbent dose on the adsorption extent were...
Relationship between global solar radiation and sunshine hours for Calabar, Port Harcourt and Enugu, Nigeria
April 2009
Elemental analysis of rice husk ash using X – ray fluorescence technique
April 2009
Rice husk ash is one of the most silica rich raw materials containing about 90 – 98% silica after complete combustion among the family of other agro wastes. Ash samples from rice husks of five different origins were prepared at two different temperatures, 500 and 1000oC, respectively and the ash content was evaluated at each temperature. The interestingly high percentage of silica (taking up from the soil during...
Adaptive lifting based image compression scheme for narrow band transmission system
April 2009
To enable wireless internet and other data services using mobile appliances, there is a critical need to support content rich cellular data communication, including voice, text, image and video. However mobile communication of multimedia content has several bottlenecks including limited bandwidth of cellular networks, channel noise and battery constraints of the appliances. In this paper an efficient adaptive data codec...
Matrices of the thermal and spectral variations for the fabrication materials based arrayed waveguide grating (awg) devices
April 2009
In the present paper, we have investigated the basic forms of the matrices of the thermal and spectral variations of the refractive-index (RI) for three different fabrication materials such as lithium niobate, polymethyl metha acrylate (PMMA) and silica-doped that are based arrayed waveguide grating (AWG) device depends on curve fitting program. Then, we are able to study the transmission spectrum characteristics of...
Optimizing planting areas using differential evolution (DE) and linear programming (LP)
April 2009
The application of differential evolution (DE) algorithm to a constrained optimization problem of irrigation water use is presented in this study. Irrigation water, amounting to 10 Mm3 is optimized to irrigate 2500 ha of land where 16 different crops are planted on different areas of land. The crops are assumed not rain-fed but depend only on irrigation water. The DE which is an evolutionary based optimization...
Speed-sensorless, adjustable-speed induction motor drive based on dc link measurement
April 2009
This paper presents a new control strategy for three-phase induction motor which includes speed and torque control loops and the current regulation thereby overcoming the limitation of volts per hertz control drives. For close-loop control, the feedback signals including the rotor speed, flux and torque are not measured directly but are estimated by means of an algorithm. The inputs to this algorithm are the...
The effect of Hibiscus anthocyanins on 2, 4-dinitrophenylhydrazine-induced hepatotoxicity in rabbits
April 2009
This study examines the effects of anthocyanin extract of the dried calyces ofHibiscus sabdariffa Linn on the 2, 4-dinitrophenylhydrazine (2, 4-DNPH)-induced toxic side effects in rabbits liver. The side effects of DNPH which include tissue lipid peroxidation and depletion of antioxidant defenses were induced in rabbits with a single intraperitoneal administration of the toxicant (28 mg kg-1 body weight) at...
Assessment of foundry properties of steel casting sand moulds bonded with the grade 4 Nigerian acacia species (gum arabic)
April 2009
Gum Arabic is a plant gum exuded from bark of some species of trees called acacia species. Nigeria produces four different grades of material. Nigeria, the second largest producer in the world has no registered commercial uses for it. This research investigated the viability of casting steel in sand moulds bonded with grade 4 Nigerian gum Arabic. Sand specimens bonded with the material were subjected to...
Vertical profiles of winds and electric fields triggered by tropical storms - under the hydrodynamic concept of air particle
April 2009
Contrary to popular understanding, tropical storms are not just weather events that can easily be described by ground - or space - based observations. Instead the phenomena are a combination of complex physical processes that occur under the accuracy of temperature and humidity conditions. The water vapour originally produced by high temperatures, serves as a source of energy that maintains tropical storms, since this...
An analytical expression for arbitrary derivatives of Gaussian functions exp(ax2)
April 2009
In this study, an analytical expression for the arbitrary derivatives of Gaussian function is developed. Using this analytical expression developed within Rodrigues representation, an alternative expression is presented for the Hermite functions. With the help of the expression presented here the Hermite functions can easily be estimated. Key words: Arbitrary derivatives, Gaussian...
FDTD studies of EM field enhancement in silver nano cylinders arranged in triangular geometry
April 2009
Metallic nano structures exhibit interesting optical properties due to the coupling of surface plasmon resonances with the electromagnetic fields. Metal nano particles exhibit dramatic field enhancement in the vicinity of the nano particle which can be further increased by near field coupling between closely spaced particles. In this paper, we study a system made of 3 nano cylinders placed at the vertices of an...
Structural elucidation of a new furoclerodane from stem barks of Croton mayumbensis J. Leonard extracts
March 2009
The stem barks of Croton mayumbensis are used by the healers of Centrafrican Republic against many diseases as microbial infections and amoebiasis. The analysis of different extracts by column chromatography, HPLC coupled with mass spectrometry lead to the identification of a new diterpenoïd with a furoclerodane squeleton. Its structure has been elucidated from spectral data: mass spectrometry, 1H...
Ethanol heterogeneous azeotropic distillation design and construction
March 2009
This study examines the design and installation of a continuous ethanol distillation unit based on the heterogeneous azeotropic approach using n-heptane as the entrainer. This technique entails the dehydration of ethanol, by which, technically, bioethanol can be produced. An ethanol distillation unit was designed, using mainly stainless steel. Bubble caps were constructed for a column which consisted of 11 stages...
Comparison of results of drift measurement of E and F region irregularities at Ibadan
March 2009
Results of measurements of drift and pattern parameters of E and F region irregularities are found to show that while these parameters for F region increase with sunspot number those of E region show no such trend. Values of drift and pattern parameters of both regions do not differ much during minimum solar activity. During maximum and moderate solar activity, on the other hand, values of drift and pattern parameter...
Periodicity of solar cycle from diurnal variations of f0F2 at Ibadan
March 2009
Some features of diurnal variations of foF2 are found to show a better response of solar activity impact than the hourly means of diurnal variation over a sunspot cycle. The ionization build-up-rate and the difference in pre- and post-noon peak are found to give 11- year periodicity for Ibadan (7.4ËšN, 3.9ËšE, 6ËšS dip) station while the hourly means are observed to give different periodicities. There is however, a...
Evaluating the global solar energy potential at Uturu, Nigeria
March 2009
Evaluation of the global solar energy potential at Uturu, latitude 0.5.33°N and 06.03°N was carried out in this work. The temperature data were obtained from 1st- 30th November, 2007 using the maximum and minimum thermometers placed in the Stevenson screen at 1.5 m above ground level. The Hargreaves equation was used to evaluate the solar energy potential at Uturu. The mean solar power potential obtained...
Groundwater potential and aquifer protective capacity of overburden units in Ado-Ekiti, southwestern Nigeria
March 2009
The study of the groundwater potential and aquifer protective capacity of over-burden units in Ado-Ekiti, Ekiti State, southwestern Nigeria have been undertaken. The area is underlain by the precambrian basement complex of southwestern Nigeria with local geology predominantly granite-gneiss and migmatite. 51 schlum-berger vertical electrical soundings (VES) were covered. The interpretation revealed three distinct...
Ecological pure ionized gaseous medium in the technology of machining
March 2009
Investigations have been carried out to using unconventional cutting fluids to prevent both health and environmental hazard caused by liquid cutting fluids. The use of liquid cutting fluids (emulsion, minerals oil, etc) during cutting process may be effective at reducing component cutting forces, improve the machined surface quality, and the tool life, but it pollutes the environment and poses health hazard to machine...
Scheduling of AGVs and machines in FMS with makespan criteria using sheep flock heredity algorithm
March 2009
This paper addresses the problem of simultaneous scheduling of machines and two identical automated guided vehicles (AGVs) in a flexible manufacturing system (FMS) so as to minimize makespan and mean tardiness. For solving this problem, a sheep flock heredity algorithm is proposed. An increase in the performance of the FMS under consideration would be expected as a result of making the scheduling of AGVs an integral...
Modified-accelerated Krawczyk’s algorithm
February 2009
An algorithm that is twice as fast as the original Krawczyk method for finding zeros of nonlinear systems of equations is obtained via the procedures of Wolfe’s modification of Krawckzyk method using the ideas derived in Uwamusi (2004). The method was implemented using Moore’s interval arithmetic. It is shown that whenever the interval arithmetic evaluation exists the Hausdorff distance R(f,[X]) and...
Soil erosion prediction using MMF model on highly dissected hilly terrain of Ekiti environs in southwestern Nigeria
February 2009
Assessment of soil erosion risk is important to formulate effective soil conservation plans for sustainable development. Information from remote sensing techniques can help decision makers prepare resource map accurately in less time and cost. GIS assists in linking those maps with other information related to geographic location and helps modeling, analyzing and solving complex problems. The objective of this study was...
Potentials of 3, 31, 41, 5, 7-pentahydroxyflavylium of Hibiscus rosa-sinensis L. (Malvaceae) flowers as ligand in the quantitative determination of Pb, Cd and Cr
February 2009
3, 31,41,5,7-Pentahydroxyflavylium chloride (cyanidin chloride) was extracted from the flowers of Hibiscus rosa-sinensis L. and blackberry fruits and the purity confirmed by co-chromatography with authentic marker on thin layer chromatography (TLC) and paper chromatography (PC). UV-Visible spectrophotometric determinations of the sample and its Pb (II), Cr (III) and Cd (II) complexes at various pH were carried...
Effect of high power ultrasound on aqueous solution of DNA
February 2009
The effect of (20 kHz continuous wave) ultrasound (power from 17 to 77 W) on the damage of nitrogen bases, the loss of double-helical structure, strand breaks and fragmentation of Calf spleen DNA were studied in vitro. The relative ultrasound sensitivity of the hydrogen bonded base pairs A-T and G-C were also studied. The techniques used in this investigation were ultraviolet absorption spectroscopy and...
Tube extrusion design for some selected inner profiles
February 2009
In this study, tube extrusion process of non-circular inner sections is optimized to satisfy micro structural criteria at maximum production speed and minimum left out material in the die cavity. The die profile design is for-mulated as a constrained non-linear programming problem, which is solved using genetic algorithms (GA). Three extrusion processes are successfully optimized based on this approach. Computer...
Hierarchical cluster analysis of hydrochemical data as a tool for assessing the evolution and dynamics of groundwater across the Ethiopian rift
February 2009
The hydrochemical evolution and flow pattern of groundwater is analyzed in a complex closed rift basin on the basis of multivariate hierarchical statistical cluster analysis. The analysis was made on the basis of water samples collected from over 120 wells and limited surface waters. The result revealed dissimilar hydrochemical phases in the rift and highlands representing different groundwater flow...
Biogas production from blends of field grass (Panicum maximum) with some animal wastes
February 2009
An investigation was carried out on the production of biogas, a low natural gas, from equal blending of field grass (F-G) with some animal wastes which include cow dung (G-C), poultry dung (G-P), swine dung (G-S) and rabbit dung (G-R). The wastes were fed into prototype metallic biodigesters of 50 L working volume on a batch basis for 30 days. They were operated at ambient temperature range of 26 to 32.8oC and...
Landslide risk analysis using artificial neural network model focussing on different training sites
January 2009
This paper presents landslide hazard and risk analysis using remote sensing data, GIS tools and artificial neural network model. Landslide locations were identified in the study area from interpretation of aerial photographs and from field surveys. Topographical and geological data and satellite images were collected, processed, and constructed into a spatial database using GIS and image processing. These factors were...
Application of discriminant analysis to predict the class of degree for graduating students in a university system
January 2009
In this Paper, discriminant analysis was used to predict the class of degree obtainable in a University system. The conditions for predictive discriminant analysis were obtained, and the analysis yielded a linear discriminant function which successfully classified or predicted 87.5 percent of the graduating students’ class of degrees. The function had a hit ratio of 88.2 percent when generalized, as a valid tool...
Effects of household wastes on surface and underground waters
January 2009
The impact of indiscriminate dumping of waste, particularly household wastes within certain locality in Ondo State, in the western part of Nigeria on the quality of surface water and underground water (that is, wells with rings and without rings) were investigated. The water was analyzed for some physico-chemical parameters and some heavy metals using the standard methods. The results show that wells without rings are...
Study of the electrochemical redox characteristics of some triazolopyrimidines
January 2009
An electrochemical study related to the redox characteristics of Ethyl-3-acetyl-6-methyl-1,4-diphenyl-4,3a-dihydro-1,3,4-triazolino[3,4-a] pyrimidine-5-carboxylate ester and its derivatives (1a-f) and (2a-e) in nonaqueous solvents such as 1,2-dichloroethane (DCE), dichloromethane (DCM), acetonitrile (AN), dimethylsulphoxide(DMSO) and tetrahydrofurane (THF) using 0.1 mol dm-3 tetrabutylammonium perchlorate (TBAP) as a...
The possible role of dynamic pressure from the interplanetary magnetic field on global warming
January 2009
Quantitative analyses suggest that the increase in global warming by about 1°C over the last century is related to the increase in geomagnetic activity. Maintained small increases in dynamic pressure in the order of a nanoPascal from the solar wind due to the expansion of the solar magnetic corona may be sufficient to produce the energy that has resulted in the increase of surface temperatures on the Earth and Mars....
Prospect assessment and risk analysis: Example from Niger Delta, Nigeria Basin
December 2008
Exploring for oil and gas is a risky business. Risk is the chance of failure, and there are many more dry wildcats than there are wells that make discoveries. The quantification of risk in relation to reward is one of the main benefits of formal assessments of undiscovered oil and gas potentials, but in this paper we consider only the geologic existence risks, and environmental risks. Key...
Photodestruction and COD removal of toxic dye erioglaucine by TiO2-UV process: Influence of operational parameters
December 2008
Aqueous solutions of Erioglaucine, a hazardous dye, are photodegraded under ultraviolet light using TiO2 as catalyst. The process has been carried out at different pHs, amounts of catalyst, concentrations of the dye, and effects of the electron acceptor H2O2. It is found that under the influence of TiO2 as catalyst the coloured solution of the dye Erioglaucine becomes colourless and the process follows...
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