June 2010
Integrated photonics devices on SU8 organic materials
In this paper, a gave a preview of targeted current research on integrated photonics based on the SU8 material was given. Such an approach takes advantage from a significant know-how regarding optical simulations by various analytical and numerical mathematical methods for the development of optical circuits on polymers. Original organic integrated photonics devoted to optical telecommunications and sensors applications...
June 2010
Flexural strengthening of RC continuous T beam using CFRP laminate: A review
Although a great deal of research has been carried out on simply supported reinforced concrete (RC) beams strengthened with Fibre-Reinforced Polymer composites (FRP), a few works has been focused on continuous beams. Particularly, experiments on strengthening the negative moment regions of continuous T beams are rare to find. This paper reviews 40 articles on CFRP strengthened RC beams and 6 articles on CFRP...
June 2010
Reducing urban heat island effects: A systematic review to achieve energy consumption balance
Considering the current energy consumption worldwide, it has become increasingly important to study the effects of urban heat island on energy consumption in order to improve the environment. This paper investigates the impact of Urban Heat Island (UHI) on energy consumption and also determines which factors can directly affect energy use in the city. The UHI current knowledge and literature are reviewed, as well as how...
June 2010
Upper mantle electrical conductivity results from the dip equator latitudes of West African region
The very first study of the upper mantle electrical conductivity profile in the West African sub region using quiet day ionospheric currents has been carried out. The magnetometer data obtained from a chain of 10 geomagnetic stations installed in the African longitudes during the IEEY 1993 experiment were used. Spherical harmonic analysis (SHA) was used to separate the internal and external field contribution to...
June 2010
Application of linear schlumberger configuration in delineation of formation strata and groundwater distribution in Ifon Ondo State, Nigeria
Linear Schlumberger configuration was employed to delineate the formation strata and groundwater distribution in Ifon Edo State, Nigeria with a view to identifying suitable sites for sitting viable boreholes for long term supply of potable water in the town and nearby communities. Ten vertical electrical soundings (VES) were made using Schlumberger array. Six soundings were made along Orin-Oyih river road and four...
June 2010
Seismic quiescence patterns as possible precursors of great earthquakes in Mexico
A catalog of shallow Mexican earthquakes (depth ≤ 60 Km) is presented for a region bounded by QUOTE 14o-21o north latitude and QUOTE 94o-106o west longitude, covering the period from January, 1806 to December, 2010, which is incomplete in this period for a wide range of magnitudes, but is complete for different ranges of magnitude in short intervals of time. The catalog is probably...
June 2010
Enhancement of TC of the (Ga,Mn) As diluted magnetic semiconductor by photoinduced exchange coupling of the Mn2+ spins
Effect of photo-excitation on the ferromagnetic transition temperature TC of the diluted magnetic semiconductor (DMS) (Ga,Mn) As is theoretically studied. The model Hamiltonian used to describe the system consists of interaction of localized Mn2+ spins with radiation field as appropriate to ferromagnetic and/or spin wave resonance. Using second order perturbation theory, an expression for photoinduced...
June 2010
Optical absorption of the hydrogenated evaporated amorphous silicon
This study focuses on the study characteristic of the optical absorption of thin films of evaporated hydrogenated amorphous silicon (a-Si: H) prepared in a built Ultra-High Vacuum (UHV). Atomic hydrogen is produced using a plasma discharge tube directed towards the substrate holder. The optical absorption coefficient was obtained in the range of 0.5 to 2.5 eV using optical transmission measurements and Photothermal...
June 2010
Comparison of electron transport properties in submicrometer ZnS and ZnO n+nn+ diode using ensemble Monte Carlo simulation
An ensemble Monte Carlo simulation has been used for the simultaneous evaluation of the electronic steady-state transport in n+nn+ ZnS and ZnO diode. The anode voltage ranges from 0 to 4 V. Electronic states within the conduction band valleys are based on a three-valley model which are represented by nonparabolic ellipsoidal valleys centered on the important symmetry point of the first Brillouin zone. Our...
June 2010
Calculated electron steady-state drift velocity in lattice matched Ga0.5In0.5P and Al0.26Ga0.26In0.48P using a three-valley Monte Carlo simulation
We present calculations based on an ensemble Monte Carlo program of the steady-state electron drift velocity in bulk Ga0.5In0.5P and Al0.26Ga0.26In0.48P as well as present a list of material parameters for these substances which are of use in the modeling of semiconductor devices made from these material types. Calculations are made using a non-parabolic effective mass energy band model, Monte Carlo simulation that...
June 2010
Measurement of radon concentration inside houses in Tafila Province, Jordan
The scope of this paper is to present a brief study related to the investigations we have already made at three districts of Tafila province, which is located in the south part of Jordan and where the most important hot spa and phosphate mines are located. The main concern in these investigations is to measure the indoor radon concentration levels by means of CR-39 detectors installed in randomly selected houses during...
June 2010
Similarity solution of hydromagnetic heat and mass transfer over a vertical plate with a convective surface boundary condition
This paper examined the hydromagnetic boundary layer flow with heat and mass transfer over a vertical plate in the presence of magnetic field and a convective heat exchange at the surface with the surrounding has been studied. The similarity solution is used to transform the system of partial differential equations, describing the problem under consideration, into a boundary value problem of coupled ordinary...
June 2010
The effects of problem-based learning on pre-service teachers’ achievement, approaches and attitudes towards learning physics
The purpose of this study was to evaluate the effects of the Problem Based Learning (PBL) method on students’ achievement in and approaches and attitudes towards an introductory physics course. With the control group, a quasi-experimental pretest–posttest design was used. A total of 25 freshman students majoring in mathematics teaching in a five-year pre-service teacher education program in Turkey...
June 2010
The effect of concept mapping on attitude and achievement in a physics course
The aim of this study was to investigate the effect of students’ concept mapping on their physics achievement and attitudes toward physics lesson. Participants were 58 ninth-grade students from the two classes enrolled to general physics course in a high school in Turkey. One of the classes was randomly chosen as experimental group (28), constructed electricity concept map, and and the other was control (30)...
June 2010
Thermal degradation of haloacetic acids in water
Haloacetic acids are commonly found in most natural waters. These are known as degradation products of some halogenated compounds such as C2- chlorocarbons and CFC replacement compounds: hydroflurocarbons (HFCs) and hydrochloroflurocarbons (HCFCs). While knowledge clarifying the particular sources of these compounds and precursor degradation mechanisms are progressing, there is less understanding of mechanisms for the...
June 2010
Proton conducting polymer electrolytes of methylcellulose doped ammonium fluoride: Conductivity and ionic transport studies
Methylcellulose (MC) was used as polymer host and Ammonium Fluoride (AF) salt was used as the proton donor. A proton-conducting solid polymer electrolytes (SPE) was prepared by the solution casting method. The highest ionic conductivity at room temperature is 6.4 x 10-7 Scm-1. The ionic mobility and diffusion coefficient that was calculated in this work is in good agreement with the increment of weight percent (wt...
June 2010
Preliminary phytochemical analysis and insecticidal activity of ethanolic extracts of four tropical plants (Vernonia amygdalina, Sida acuta, Ocimum gratissimum and Telfaria occidentalis) against beans weevil (Acanthscelides obtectus)
Ethanolic extracts of the leaves of Ocimum gratissimum, Sida acuta, Telfaria occidentalis and Vernonia amygdalina were screened for secondary metabolite constituents and insecticidal activity against beans weevil (Acanthscelides obtectus). Phytochemical screening of the extracts revealed the presence of alkaloids, flavonoids, saponins, steroids, tannins, phlobatannins and terpenoids in the plants...
June 2010
Multi-focus image fusion in high precision close-range photogrammetry
The close-range photogrammetry is a discipline of precise metric measurement of features with applications ranging from the deformation of architectural structures to the medical diagnosis. One of the limitations on the precision of the obtained images is the large differences in depth. On the other hand, obtaining pictures that focus on every direction with lenses used in close range photogrammetry is mechanically...
June 2010
Design information in managing refurbishment projects in Malaysia
Although design cost makes up a small percent of a total project cost, the performance of refurbishment projects are normally considerably affected by design processes. The lack of information in refurbished designs becomes an obstacle for designers to complete tasks successfully during the initial stage of the design process. The objective of this study is to discuss the sources of design information in refurbishment...
June 2010
Improvement of hydraulic stability for spillway using CFD model
Hydraulic model test was used to analyze the rapidly varied flow on the spillway. But, it has some shortcomings such as error of scale effect and expensive costs. Recently, through the development of three dimensional computational fluid dynamics (CFD), rapidly varied flow and turbulence can be simulated. In this study, the applicability of CFD model to simulate flow on the spillway was reviewed. The Karian dam in...
June 2010
Modeling of pre-cast concrete hybrid connections by considering the residual deformations
This paper presents an alternative section analysis and hysteretic modeling for the response of pre-cast concrete hybrid connections which have different level of mild steel contributions to the connection flexural capacity. Well-known classical reinforced concrete section analysis approaches cannot be directly applied to the pre-cast concrete hybrid connections due to the strain incompatibility between the...
June 2010
Damped free vibration analysis of a beam with a fatigue crack using energy balance method
In this paper, a new approach based on the energy balance method is proposed for free vibration analysis of a cracked cantilever beam by taking into account both the structural damping and the damping due to the crack. Also, by taking into account the effect of opening and closing the crack during the beam vibration, the stiffness changes at the crack location are considered to be a nonlinear amplitude-dependent...
June 2010
The effects of vortex finder on the pressure drop in cyclone separators
In this study, three cylinder-shaped vortex finders with diameters of 80, 120 and 160 mm were designed and manufactured to find out the pressure drop of the cyclones by experimentally investigating the effects of gas inlet velocity, the vortex finder diameter and length on the cyclone performance at different gas concentration. As a result of this experimental analysis, a critical diameter of vortex finder is...
June 2010
Impacts of quality and processing time uncertainties in multistage production system
The primary objectives of this research are to develop simulation models for multistage production system under processing time and quality variation, to identify areas of potential bottleneck in production system and to determine the optimum production lot size for each station in a multistage production system under the uncertainties to minimize the WIP level and lead time and thereby the total system cost....
June 2010
Considerations of the extraction process and potential technical applications of Nigerian rubber seed oil
Rubber seeds from the rubber tree (Hevea brasiliensis) are in abundance in Nigeria from which non-edible oil could be obtained. However, the seeds are wasted in the rubber plantations annually even though the extractable oil has potential technical applications. If the full potentials of the oil are to be realized, there is need to have a data base information on the oil extraction process and its properties....
June 2010
Deacidification of high acidic rubber seed oil by reesterification with glycerol
Some studies have shown that rubber seed oil (RSO) from the seed of rubber tree (hevea brasiliensis) has potential technical applications. However, the high free fatty acid (FFA) associated with the oil may be a limiting factor in its applications. In this study, crude rubber seed oil (RSO) containing 37.69% FFA was deacidified using 4.3-5.6% of glycerol. The reactions were carried out at a pressure of 20mmHg in the...
June 2010
QoS improvement for multimedia traffic in WLANs with TTN approach
This study proposes a Time Division Multiple Access (TDMA) based token passing MAC (Media Access Control) protocol, TTN (TDMA based Token Network). In the proposed scheme, the Access Point (AP) assigns time slot to the stations and passes on a token. The stations are allowed to transmit only when they get hold of the token. Through simulation study, it is shown that TTN can perform better in case of throughput, delay...
June 2010
Interworking between WiMAX and UMTS to provide seamless services
This article represents an interworking architecture between Universal Mobile Telecommunications System (UMTS) and WiMAX where Third Generation Partnership Project (3GPP) IP Multimedia Subsystem (IMS) and Mobile IPv4 are applied together to maintain the continuity of an on-going session and for that to keep the Internet Protocol (IP) address to be static while the consumer having...
June 2010
Information flow analysis of UCON
The UCON model extends traditional access control models through continuity of access decision and mutability of subject and object attributes. Due to these two features, the flow of information in UCON becomes considerably different from traditional access control models. A thorough analysis of this information flow is beneficial in any scenario where UCON is used. In this paper, we analyze information flow in UCON. In...
June 2010
Magnetic and electrical resistivity image survey in a buried Adramytteion ancient city in Western Anatolia, Turkey
This paper examines a buried Adramytteion ancient city in the Balıkesir-Burhaniye-Ören district located in the Western Anatolian region of Turkey. In this research, the some ruins in Adramytteion with the different properties such as magnetic and resistivity is investigated using plausible techniques, which are not experienced before. The attached ruins with the magnetic and resistivity attributes are diagnosed...
June 2010
The development of enhancing mechanisms for improving the performance of IEEE 802.15.4
There has been increasing interest in wireless network system in recent years, yet there are many issues to be resolved, mainly on topics related to its application design, such as the field of robot, artificial intelligence, and healthcare system etc. IEEE 802.15.4 is a standard protocol needed to achieve the low cost, low power consumption and low data rate Low-Rate Wireless Personal Area Network (LR-WPAN) widely used...
June 2010
Bishop spherical images of a spacelike curve in Minkowski 3-space
In this work, we introduce Bishop spherical images of a spacelike curve in terms of Bishop trihedra in Minkowski 3-space. With this aim, we translate Bishop frame vectors to the center of Lorentzian sphere and give some characterizations. Additionally, we illustrate an example of our main results. Key words: Classical differential geometry, spacelike curve, spherical image, Minkowski space.
June 2010
Solving a system of nonlinear fractional partial differential equations using three dimensional differential transform method
In this article, three dimensional fractional partial differential transform method (FPDTM) has been employed to obtain solutions of a System of nonlinear fractional partial differential equations. This indicates the validity and great potential of the homotopy analysis method for solving system of fractional partial differential equations. Fractional differential transform method can easily be applied to nonlinear...
June 2010
Examination of cutoff grade parameters in magnesite mineral deposit
One important critical value in mineral deposits is cutoff grade. The cutoff grade is defined as the value which discriminates between ore and waste with a given mineral deposit. In this study, the cutoff grade parameters such as SiO2 and CaO% are examined by statistical distribution model. This paper shows a procedure for using the bivariate lognormal statistical distribution model with two uncorrelated samples to...
Advertisement
Advertisement
