Modeling the rate of biocorrosion and the effects of redox-reactions of metals in water environment
December 2011
Laboratory studies were conducted to assess the effectiveness of biocorrosion through oxygen diffusion in zinc metal in water environment. The present investigation was undertaken to determine the corrosion rate of zinc metal in water environment with respect to Plank-Nernst Equation modified to monitor and predict the biocorrosion rate through oxygen diffusion which resulted to biofilm formation. The...
A novel electrical model to an antenna array
November 2011
In this paper, an electrical model is developed to represent the input admittance of an antenna array with a finite number of elements. This model consists of an RLC bock component to represent the input admittance of each elementary antenna element and a capacity component to represent different degrees of antenna coupling effects. The equations based on cavity model are developed to represent physical...
Electromyographic (EMG) signal to joint torque processing and effect of various factors on EMG to torque model
November 2011
This study present electromyographic (EMG) signal to torque model and investigates the effects of various factors on EMG signal and EMG to torque model. Pre-processing techniques are applied on EMG signal in order to remove the DC offset, 60 Hz noise and to estimate the EMG amplitude. The estimated EMG amplitude is then mapped to joint torque using a new non-linear equation. This equation uses some...
Performance evaluation of bamboo with morter and concrete
November 2011
Bamboo has remarkable properties as a construction material, being both light weight and extremely strength and durable. Moreover it grows all over the Bangladesh; a South Asian lower-middle income country where rural people is the majority of the total population. Bamboo having considerable tensile and compressive strength as a construction material is used widely in Bangladesh. But the main problem that it...
Influence of finishing temperature on the mechanical properties of conventional hot rolled steel bar
October 2011
The conventional mill operators are faced with challenges of producing reinforcing steel bars of adequate strength characteristics. This stems from the inability to effectively control and monitor process variables such as temperature, strain-rate and cooling. These parameters collectively determine the microstructure and invariably the mechanical properties of the rolled bars. However, the finishing...
An investigation of the effect of hall current and rotational parameter on dissipative fluid flow past a vertical semi-infinite plate
October 2011
Magneto hydrodynamics (MHD) stokes problem for a vertical semi-infinite plate in a dissipative rotating fluid with hall current has been considered. The partial differential equations governing the problem are framed and then solved using numerical methods of implicit finite difference approximations. An analysis of effects of parameter on the velocity (both primary and secondary) profiles and...
Stochastic redundancy allocation problem using simulation
September 2011
Reliability is one of the main parameters of the products considered to be important to survive in the competitive market. Reliability in its simple form means the probability that a failure may not occur in a given period of time that is, the component performs adequately without failure. The subsystems or components in a system are arranged in series or parallel depending on the space constraint. However,...
Electrochemical properties of metals in cassava fluid
September 2011
This study was carried out to investigate and evaluate the electrochemical properties of mild steel (0.6, 1.0 and 1.46 mm), galvanized steel (0.36, 0.6 and 1.24 mm) and aluminium (0.9 and 1.3 mm) sheets exposed to cassava fluid. Corrosion rates of mild steel (10.595 mm/yr), galvanized steel (11.26 mm/yr) and aluminium (9.556 mm/yr) sheets exposed to cassava fluid were got using weight loss technique. The...
Ultra low loss of a thermal arrayed waveguide grating (AWG) module in passive optical networks
September 2011
In the present paper, high transmission bit rate of a thermal arrayed waveguide grating (AWG) which is composed of lithium niobate (LiNbO3)/polymethyl metha acrylate (PMMA) hybrid materials on a silicon substrate in passive optical networks (PONs) has parametrically analyzed and investigated over wide range of the affecting parameters. We have theoretically investigated the temperature dependent wavelength...
Effect of rapid quenching and aging on tensile behavior of commercially pure (CP) titanium implant material
September 2011
Pure titanium and titanium alloys are widely used as implant materials in the medical and dental fields because of their superior bio-compatibility, corrosion resistance and specific strength compared with other metallic implant materials. Study of mechanical properties of these implant materials is very important during the course of their machining, fabrication and surface treatment...
Modeling the distribution of primes in computable biomolecules
September 2011
Prime numbers are an important research area with application in computer security. The security of certain cryptographic schemes critical in information security lies in the difficulty of factoring large numbers into their prime factors. Determination of the distribution of prime numbers is an important unsolved problem in number theory. Biomolecules such as DNA have extended the domains of what is...
Electrical characterization of in-house fabricated polysilicon micro-gap for yeast concentration measurement
August 2011
Fabrication and electrical characterization of micro-gaps and their properties are discussed with their applications in electrochemical sensors and bimolecular detection. To understand the relationship between the biosensor and micro-structure we have carried out the fabrication and characterization of micro-gap structures for yeast concentration measurement. In this paper two photo mask designs are used. The first mask...
Effect of geopathic stress zone on human body voltage and skin resistance
August 2011
Geopathic stress zones are places on the surface of the Earth known to cause health problem. Empirical knowledge of the existence of geopathic stress is probably as old as mankind. The aim of this study is to evaluate the effect of geopathic stress on human body. It further tries to scientifically evaluate dowsing phenomenon by measuring body voltage, skin resistance, using V-20 bio voltmeter, GSR-2 biofeedback...
Atomic force microscopy (AFM) and X-ray diffraction (XRD) studies of BiFeO3 nanoparticles with sol–gel
August 2011
Recently, there has been considerable interest in studying nanostructural properties of Bismuth (Bi) as a good electrode of electro-analysis, shape–memory alloys and photo-typical multiferric devices. We have thus demonstrated a series of experiments to synthesis Bi and BiFeO3 (BFO) nanoparticles using sol–gel method at ambient pressure and study their nanostructural properties using tapping mode of...
Smart crack detection of a cracked cantilever beam using fuzzy logic technology with hybrid membership functions
August 2011
Damage detection methods have been considerably increased over the past few decades. A crack in a structural member introduces local flexibility that would affect vibration response of the structure. This property may be used to detect existence of a crack together with its location and depth in the structural member. The presence of damage leads to changes in some of the lower natural frequencies and mode...
Low temperature synthesis of La2O3 and CrO2 by Sol–gel process
July 2011
Some issues such as tunneling, leakage current and light atom penetration through the film are threatening the ultra thin SiO2 be as a good dielectric for future industrial and electronic devices and in ceramic technologies. A series of experiments to synthesis La2O3 as well as CrO2 has been done at low temperature with using sol-gel method. The nano structural properties of La2O3/CrO2 equipped with...
Two-dimensional particle modeling of submicrometer ZnO MESFET based on an ensemble Monte Carlo calculation including five-valley band structure model
July 2011
A Monte Carlo method has been developed for the study of electron transport properties in ZnO MESFET for high field, using a five-valley conduction band model. The effects of upper valleys on the characteristics of ZnO MESFETs have been investigated. The following scattering mechanisms, that is impurity, polar optical phonon, acoustic phonon, alloy and piezoelectric are included in the calculation. Ionized impurity...
Road and urban storm water drainage network integration in Addis Ababa: Addis Ketema Sub-city
July 2011
Urbanization along with its impermeable structures is the major causes of flooding in urban areas. Urban storm water influences the service life of urban infrastructures. The rainfall intensity and characteristics of catchment area are the major factors for designing urban storm water drainage facilities. These facilities have a paramount advantage to safely dispose the generated floods to ultimate receiving system....
Foundation of vortex gravitation, cosmology and cosmogony
July 2011
A hypothesis is proposed concerning the cause of the origin of universal gravitation. This cause consists of a system of the ether vortex rotations. Physical and mathematical grounds are described and the formula for the determination of the space gravitation forces is deduced. On the basis of the vortex gravitation, the principles of creation and existence of the celestial bodies are shown. Methods of the use of the...
Does a physically reasonable solution of the Navier Stokes equations exist?
June 2011
According to the literature, the conservation of momentum equation needs to be coupled with the mass conservation equation. However, they cannot create a coupled system of equations of motion because they ignored third Newton law. The conservation of momentum equation is Newton’s second law of motion, whereas conservation of mass belongs to kinematics that have no deal with forces at all. However, no one motion in...
Efficient enhancement of polymer light emitting diode by inserting hole blocking layer
June 2011
The triplet layer for the PLED was fabricated with ITO / PVK (77 nm) / CdS (115 nm) / Alq3 (84 nm) / Al (300 nm). The PLED devices were inserted in the CdS layer between the 77 nm PVK and 84 nm Alq3 absorbing the ambient light to reduce the reflection of the device. The maximum wavelength and luminescence intensity increase with the thickness of CdS. This indicated that the maximum wavelength shifted to a higher...
Opto-mechanical design, analysis and economical manufacture of a large aperture LIDAR receiver telescope
June 2011
Aryabhatta Research Institute of Observational Sciences (ARIES) at Nainital (29° 22’ N, 79° 27’ E, 1950 m amsl) is located in the central Himalayan region. Taking benefit of its pristine geographical location away from major urban pollution a LIDAR system was planned at this location to study the dynamics of atmosphere. Optical design analysis of LIDAR receiver telescope with backend detection optics...
Polygon graphs of Girth 6
June 2011
This paper introduces a family of simple bipartite graphs denoted by , named and constructed as polygon graphs. These polygon graphs are bicubic simple graphs possessing Hamiltonian cycles. Some important results are proved for these graphs. The girth of these graphs is counted as 6(). Polygon graph is isomorphic to a famous Pappus graph. Since polygon graphs are bipartite, therefore they can be used as...
Analysis of smart crack detection methodologies in various structures
May 2011
This paper describes a comprehensive review of various technical papers in the domain of crack detection in Beam-Like Structure. Sensibility analysis of experimentally measured frequencies as a criterion for crack detection has been extensively used in the last decades due to its simplicity. However determination of crack parameters (like depth and location) is not straight forward. The various techniques discussed on...
Deoxyribonucleic acid (DNA) as a hypothetical information hiding medium: DNA mimics basic information security protocol
May 2011
While the computational capabilities of deoxyribonucleic acid (DNA) are now fairly known, with the building of DNA computers which utilize DNA and other sub-cellular molecules as input and output, little seems to have been investigated on the information security properties of DNA in computer science and information technology terms. The author investigated DNA as a hypothetical information hiding molecule, which...
Determination of oscillator strength of caffeine and caffeine in tea leaves by the integrated absorption coefficient technique at two different temperatures
May 2011
In this paper, oscillator strength of caffeine in dichloromethane, water, chloroform, and ethyl acetate were calculated in the wave number range of 32, 000 to 41,000cm-1. It was found that oscillator strength of caffeine in dichloromethane, water, chloroform, and ethyl acetate were 0.230 ± 0.001, 0.170 ± 0.0003, 0.114 ± 0.001, 0.150 ± 0.001 respectively. Caffeine content of real tea leaves...
Statistical digital image stabilization
May 2011
In this paper, an efficient algorithm for the statistical digital Image stabilization (SDIS) is proposed to reduce the computational cost of block matching algorithm, for local motion estimation. This method is based on calculation of statistical functions, mean and variance of pixels in each block; four blocks are used in each frame. By using the statistical functions, the best block is selected then the local motion...
Seismic isolation in buildings to be a practical reality: Behaviour of structure and installation technique
April 2011
Although a great deal of research has been carried out regarding seismic isolation, there is a lack of proper research on its behavior and implementing technique in low to medium seismic region. The basic intention of seismic protection systems is to decouple the building structure from the damaging components of the earthquake input motion, that is, to prevent the superstructure of the building from...
Analytical and experimental study of velocity shear instability in the presence of inhomogeneous perpendicular D.C electric field
April 2011
Analysis and experimental study of parallel flow velocity shear electrostatic ion cyclotron (EIC) instability has been done in plasma containing massive positive ions and electron by using the method of characteristics solution and kinetic theory in the presence of inhomogeneous direct current (DC) electric field perpendicular to ambient magnetic field. The effect of many parameters on growth rate and real...
Belief network-based acoustic emission analysis for real time monitoring in CIM environment
April 2011
Machining is the most important part of the manufacturing process. Machining deals with the process of removing material from a work piece in the form of chips. Machining is necessary where tight tolerances on dimensions and finishes are required. The common feature is the use of a cutting tool to form a chip that is removed from the work part, called Swarf. Every tool is subjected to wear in machining. The...
Bulk strain estimation on gneisses in Central Nigeria: A preliminary assessment
April 2011
The challenges of regional metamorphism and the need to investigate the petro-structural strain and tectonic evolution of the Nigerian basement using central Nigeria contact zone is useful in mineral exploration. Meso-structural data were plotted using GEOrient to obtain general trend as well as the axial folds of the Pre-Pan African deformation. Strain estimation was done on photomicrographs of the gneisses...
Location-aware information services platform for mobile users in Nigeria
March 2011
Ongoing advances in technology and proceeding miniaturization have led to growing popularity and widespread use of mobile devices. A modern research direction is location-aware computing, which aims at providing services to users taking into consideration the location of the user in space. Apart from communication features and basic functionality like address books or organizers, users expect today’s...
Low temperature characteristics of dielectric properties for Tl4S3 layered single crystals
March 2011
The current investigation was fulfilled for insight into the dielectric properties of Tl4S3layered single crystals. The real part of dielectric constant ε׳, imaginary part of dielectric constant ε×´, the dissipation factor tan δ and the alternating current conductivity σac were measured in an applied ac electric field of frequencies extending from 2.5 to 50 kHz. These...
The effect of magnetic water on strength parameters of concrete
March 2011
A machine for magnetic water treatment is designed and its application on the ions contained in water has been investigated to examine the effect of magnetic water on concrete parameters. Strength parameters of concrete have been studied for more than 104 concrete samples, including the non-magnetic samples (made by ordinary water) and magnetic samples (made by magnetic water), with slump and...
Computational approach for comparative phylogenetic analysis of isolated chromium resistant strain Brevibacterium casei
March 2011
The isolated (Cr [VI]) resistant bacterial strain was identified as Brevibacterium caseiby 16S rRNA sequencing (Genbank Accession Number: EU781952). The generated sequenced data was used for construction of Phylogenetic tree (MEGA 3.1and clustalw2) and predict the two dimensional alignment of the highly conserved regions. Computational comparative 16S rRNA sequence analysis of the isolated strain with...
A study on the engineering properties of sandcrete blocks produced with rice husk ash blended cement
March 2011
Sandcrete blocks have been in used in many nations of the world including Nigeria, playing a major role in the building industry. The material constituents, their mix, presence of admixtures and the manufacturing process are important factors that determine the properties of sandcrete blocks. This paper investigates the effects of a partial replacement of cement with rice husk ash (RHA) on some engineering...
The influence of transient strain rate deformation on the microstructure of AA2024 aluminum alloy in the low temperature range
February 2011
Constant and varying strain rate deformation conditions have been applied to AA2024 aluminum alloy using hot compression testing in the temperature range of 200-300°C. The initial strain rate of 0.1 s-1 and the second pass strain rate of 0.0001, 0.001 and 0.01 s-1 have been applied and tested. This research shows that in low temperature range with decreasing strain rate in the second pass, the straining...
Appraising the structural geology of Kakuri Sheet 144: Implications for the tectonic evolution of the basement complex
February 2011
The appraisal of the structural geology of Kakuri Sheet 144 using integrated analyses of remotely sensed lineaments, aeromagnetic anomaly, micro and macro structures show a tectonic framework expressed by a mainly NW – SE ductile vertically dipping foliation of transpressed tectono-metamorphic possibly pre-Pan African (S1) trend which has been overprinted by a set of NE – SW (L2) fracture system...
Precision and repeatability analysis of Optotrak Certus as a tool for gait analysis utilizing a 3D robot
February 2011
In both scientific and clinical investigations, the precision and repeatability of instruments are demanded; however, precision of motion analysis systems has been reported in the literature rarely and studies are generally not comparable. This study introduces a new method of determining precision and repeatability of Optotrak Certus, a motion analysis tool for gait analysis using a three dimensional (3D)...
Microstructure of different NaOH molarity of fly ash-based green polymeric cement
February 2011
Every 1 ton of concrete leads to CO2 emissions which vary between 0.05 to 0.13 tons. About 95% of all CO2 emissions from a cubic yard of concrete are from cement manufacturing. It is important to reduce CO2 emissions through the greater use of substitute to ordinary Portland cement (OPC) such as fly ash, clay and others geo-based material. This paper, report on the study of the processing...
Stability and accuracy of the finite difference time domain (FDTD) method to determine transmission line traveling wave voltages and currents: The lightning pulse
February 2011
The numerical solution of the transmission line wave equation is examined using the transmission line model of a lightning return stroke (LRS) taken as a case study. The LRS is represented by a transverse electromagnetic wave travelling at a velocity close to the velocity of light along a highly ionized lightning leader channel. The leader channel is modeled as a lossy transmission line. Attempts to model the...
Review on fly ash-based geopolymer concrete without Portland Cement
January 2011
The consumption of Ordinary Portland Cement (OPC) caused pollution to the environment due to the emission of CO2. As such, alternative material had been introduced to replace OPC in the concrete. Fly ash is a by-product from the coal industry, which is widely available in the world. Moreover, the use of fly ash is more environmental friendly and save cost compared to OPC. Fly ash is rich in silicate and...
Spiking neural network-based control chart pattern recognition
January 2011
Due to an increasing competition in products, consumers have become more critical in choosing products. The quality of products has become more important. Statistical process control (SPC) is usually used to improve the quality of products. Control charting plays the most important role in SPC. Control charts help to monitor the behavior of the process, to determine whether it is stable or not. Unnatural...
Low-cost treatment for attenuation of nitrate from groundwater
January 2011
Elevated nitrate levels in drinking water by nitrate are an evolving public health concern, since nitrate can undergo endogenous reduction to nitrite, and nitrosation of nitrites can form N-nitroso compounds, which are potent carcinogens. Nitrates are also responsible for a number of health disorders, both in human beings and animals. Thus, nitrate reduction from water has become critical and the need of the...
Modified cumulative sum quality control scheme
December 2010
A modified two-sided cumulative sum (MOCUSUM) quality control scheme is proposed that improves CUSUM (cumulative-sum) in average run length (ARL) properties. The MOCUSUM scheme is based on single cumulative sum that may be positive or negative and hence can be generalized to multivariate MOCUSUM scheme easily. In this scheme, the ‘large’ CUSUM values are shrunk towards zero, but the...
Multi-criteria decision making using fuzzy logic approach for evaluating the manufacturing flexibility
December 2010
Manufacturing flexibility is the ability of a manufacturing system to cope with environmental changes effectively and efficiently. Most operation managers cannot provide exact numerical values to express opinions based on human perception due to ill defined and ambiguity of flexibility assessment. However, fuzzy logic provides a useful tool to deal with problems in which the phenomena are imprecise and vague....
Genetic algorithm based diamagnetic shift investigations of the GaAs0.7Sb0.3/GaAs and Al0.3Ga0.7As quantum wells
December 2010
In this work we have presented some other aspects of the recently introduced GMV method (Genetic Monte Carlo Variational method). The CPU time of the method is computed and then we have applied the method to As0.7Sb0.3/GaAs quantum well to investigate the effect of the well width and Sb fraction on the diamagnetic shift. The effect of the Al doping instead of the Sb is also investigated. Key...
Some new aspect of the application of Genetic algorithm to investigate nanostructures
December 2010
Some new aspect of the application of Genetic algorithm to nanostructures is presented. We followed a method that is produced by using the Genetic Algorithm, Variation method and Monte Carlo integration Scheme (GMV method). Computational algorithm, deficiencies and advantages of the method is described and it is applied to a GaAs0.7Sb0.3/GaAs quantum well. Key words: Genetic algorithm,...
Reliability assessment of 3-phase three winding converter transformer of HVDC transmission system
November 2010
High voltage direct current (HVDC) is today recognized as an effective and efficient means of transmitting bulk power over long distances through over head lines or cables. The reliability of HVDC links have always been of primary concern in planning and operating of power systems. The existence of spares and maintenance practices do affect the availability of HVDC stations. The HVDC converter transformer...
Determination of weathered and fractured zones in part of the basement complex of North-Eastern Nigeria
November 2010
Two electromagnetic (EM) traverses and seven schlumberger vertical electrical soundings (VES) were carried out using “APEX MAXMIN” EM machine equipped with a transmitter and a receiver and a “GEOPULSE” resistivity meter to study formation strata that could host groundwater within the overburden and fracture/fault zones of the basement complex along Gwoza-Damboa road in Borno...
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