Print ISSN: 1681-6900

Online ISSN: 2412-0758

Volume 27, Issue 5

Volume 27, Issue 5, March 2009, Page 157-1025


(Preparation of Pyrolytic Graphite (PG) Shell Using CVD Technique)

Abdul- Qader Dawood Faisal

Engineering and Technology Journal, 2009, Volume 27, Issue 5, Pages 868-879

A Pyrolytic graphite (PG) shell was produced by Chemical Vapor
Deposition (CVD) using a new modified vacuum furnace. The deposition
experiments of (PG) were achieved on a substrate of solid rods and slabs of
commercial graphite. This was selected as a miniaturized mandrel for deposition
experiments. The substrate was heated at temperature range of (1500ºC-2300ºC)
and a hydrocarbon gas (liquid benzene) was used with a pressure range of
(1.5mbar- 2.5 mbar).A flow of hydrocarbon gas was admitted into the chamber
and the PG was deposited by decomposition of the gas at high temperature on
preheated graphite mandrel as previously mentioned. Methane gas was also used
for deposition experiments at high temperature range (1700ºC-2000ºC) and
pressure range of (100mbar-200mbar) .The thickness of the prepared material was
measured as a function of T, P and time. An x-ray diffraction analysis has been
done for the prepared PG shell and compared with standard grid electrode for high
power electronic tubes made of PG. The calculated density of the deposited layer
produced in this work at maximum temperature was about (2.1±0.1 g/cm3) .A high
temperature calibration was achieved using Stephan -Boltzmann's law for
different melting point metals (Cu, Ni, Ta, Mo).In addition an optical pyrometer
was also used for this calibration. Finally, the prepared PG shell of this work was
exposed to a high temperature oxyacetylene burner test at the atmosphere. The test
shows no visual deformation of the external material

The Effect of Thermal Annealing on the Diffusion Profile of Nickel in GaAs Substrates

Aseel A.K. Hadi

Engineering and Technology Journal, 2009, Volume 27, Issue 5, Pages 880-885

Diffusion of nickel in GaAs has been studied at 950ºC. The diffusion was
enhanced during limited interval and for different quantities of As. Nickel atoms
had diffused in the beginning due to the interstitial movement of atoms but large
number of nickel atoms occupies substantial locations in p-type GaAs lattice.
Measurements performed to the samples have showed good agreement between the
nickel atoms concentration and majority charge-carriers in p-type semiconductor
(holes). Measurements explained that electrical conductivity of p-type samples was
not due to system heating but to the diffusion of nickel atoms occupying sites of
gallium atoms.

Approximation Solution of Volterra Integral Equation Using Adomian Decomposition Method

Khawla A. AL-Zubaidy

Engineering and Technology Journal, 2009, Volume 27, Issue 5, Pages 886-890

In this paper, Adomian Decomposition method has been used to find the approximation
solution for the linear Volterra integral equation of the second kind. In this method the solution of
a functional equation is considered as the sum of an infinite series usually converging to the
solution, and the Adomian decomposition method is also used to solve linear integral equation.
Finally, numerical example are prepared to illustrate these considerations.

Synthesis of novel metal complexes of 5-(4-isopropoxyphenyl)-Nphenyl- 1,3,4-thiadiazol-2-amine

Ahmed AbdulAmier Hussain Al-Amiery; Muna A. Shakir; Maysoon Yousif

Engineering and Technology Journal, 2009, Volume 27, Issue 5, Pages 891-897

New5-(4-isopropoxyphenyl)-N-phenyl-1,3,4-thiadiazol-2-amine have been
synthesized in good yield by the reaction of N-phenylhydrazinecarbothioamide with a 4-
isopropoxybenzoic acid in phosphorusoxychloride. Cr(III), Co(II), Ni(II),Cu(II),Zn(II)
and Cd(II) complexes of 5-(4-isopropoxyphenyl)-N-phenyl-1,3,4-thiadiazol-2-amine
have been prepared, and characterized by elemental analysis, FT-IR, and UV/visible
spectra moreover determination of molar ratio M:L , determination of metal content M%
by flame atomic absorption spectroscopy, molar conductance in DMF. solution and
magnetic moments (μeff.).

A High Quality Output Voltage for HEPWM of Single Phase AC Motor Drive

Mohammed K. Edan; Ali H. Jabbar; Jamal A. Mohammed

Engineering and Technology Journal, 2009, Volume 27, Issue 5, Pages 898-912

provide the exact on-line solution to the optimal PWM problem. The proposed
algorithm optimization technique is applied to a 3-level unipolar single-phase inverter to
determine optimum switching angles for eliminating low order harmonics while maintaining
the required fundamental voltage to drive single-phase induction motor with high quality.
The proposed HE method contributes to the existing methods because it not only generates
the desired fundamental frequency voltage, but also completely eliminates any number of
harmonics. It provides high quality sine-wave output voltage on the induction motor
terminals with very low THD.
The high quality sinusoidal output voltage produced by the inverter at different number
of switching angles is presented. The complete solutions for 3-level unipolar switching
patterns to eliminate the 3rd and 5th harmonics are given. Finally, the unipolar case is again
considered where the first 14 harmonics are eliminated.

Experimental Tests on Orthotropically RC Rectangular Slabs Having Various Restrained Edges and Subjected to Uniform Load

Husain M. Husain; Hisham M.AL-Hassani; Sarmad S. Abdul-Qader AL-Badri

Engineering and Technology Journal, 2009, Volume 27, Issue 5, Pages 913-929

In this research, nine orthotropically reinforced concrete (RC) rectangular slabs
having various boundary restraints at the edges are tested under uniformly distributed
load. The main aim of these tests is to show that when some or all edges of a slab are
restrained against rotation and horizontal translation the ultimate load carrying capacity
of the slab will be enhanced greatly above that suggested by the simple Johansen ,s yield
line theory(1). For this purpose, a specially designed rig is constructed and used for
providing slabs with various boundary restraints along their edges.
The results of tests, which are presented in the form of load-deflection curves plotted
non-dimensionally, show that for restrained slabs the enhancement in load above
Johansen ,s load ranges between 50% and 100% depending on the number and positions
of the slab restrained edges. These results are also used to examine the accuracy of a
recently submitted elastic-plastic theoretical model(2).

An Investigation of the Inhibition of the Oxygen Reduction Reaction at a Rotating Cylinder Electrode under Isothermal and Controlled Conditions of Heat and Mass Transfer

Shatha. A. Sameh; Sadiq. H. Alwash

Engineering and Technology Journal, 2009, Volume 27, Issue 5, Pages 930-941

The inhibition of the oxygen reduction reaction on a carbon steel rotating
cylinder electrode in naturally aerated 600 ppm Cl- solution was studied using an
optimum inhibitor blend, i.e., Sodium Nitrite (SN): Sodium Hexametaphosphate
(SHMP) = 500:100 obtained via a weight loss technique. Potentiostatic technique, then,
was applied at different bulk temperatures and various flow rates using un-inhibited and
inhibited solutions under isothermal and controlled conditions of heat transfer.
In an un-inhibited solution and under isothermal conditions, with limiting conditions of
concentration polarization, the limiting current density of oxygen reduction reaction is
flow and temperature dependent. The charge transfer of the oxygen reduction reaction is
a 4 electron process in the range of bulk temperature employed from 303 to 323 K.
Under heat transfer conditions, the charge transfer is still 4 electron process up to 336 K
interfacial temperature, above which the contribution of the 2 electron process appeared.
Moreover, the limiting current density values of the oxygen reduction reaction in
inhibited solutions is much lower than those under identical conditions in un-inhibited
solutions. This confirms the inhibition of the cathodic reaction, i.e., the oxygen
reduction reaction under isothermal and heat transfer conditions, due to SHMP.

Analysis of Composite Bridge Superstructures Using Modified Grillage Method

Sabeeh Z. Al-Sarraf; Ammar A. Ali; Rana A. Al-Dujaili

Engineering and Technology Journal, 2009, Volume 27, Issue 5, Pages 942-953

The analysis principle was used to analyze anisotropic plates (having different
elastic properties and geometries in different directions), the model consists of four side
beams with flexural rigidity and torsional rigidity and two diagonal beams with only flexural
rigidity .
The substitute grid framework is analyzed to give the same deformations and
deflections of the orthotropic plate elements of the modeled bridge. Applicability of the
suggested procedure in the analysis of actual bridge decks is investigated using STAAD
Pro.2006 program. The results show that the suggested procedure is an acceptable procedure
which can be adopted to analyze this type of bridge deck. It is found that the modified
grillage method gives simpler method and adequate results when compared with the Finite
Element Method or orthotropic plate theory solved using Finite Difference Method for this
type of bridges.

A Restriction Enzyme from Escherichia coli Purification and General Properties

Mukaram Shikara; Nadia Tariq Barakat; Maysem Modaffer Al-Obaidy

Engineering and Technology Journal, 2009, Volume 27, Issue 5, Pages 954-961

An endonuclease restriction enzyme has been purified from E. coli about 40-fold with
DNAse and RNAse recoveries of about 3%. The purification steps included precipitation
of the enzyme with ammonium sulphate, and reclaimed it through Sephadex G-100 and
DEAE-cellulose chromatography. The purified endonuclease was able to break lambda
DNA into three bands. The enzyme has 5% of carbohydrate moiety which means it is a
glycoprotein. Lastly, the comparison with other commercial restriction endonucleases
proves that this enzyme is a restriction enzyme with enzymic activity dependent on
Mg2+

Three-Dimensional, Unsteady, Inviscid Flow in an Axial Turbine Stage

Abdulhassan A. Karamallah; Talib Z. Farge; Sudad I. Younis

Engineering and Technology Journal, 2009, Volume 27, Issue 5, Pages 962-972

This paper presents an advanced approach to compute the three-dimensional,
rotational, adiabatic, inviscid flow of a perfect gas in a highly twisted transonic axial turbine
stage. The time-dependent Euler equations, expressed in a Cartesian coordinate system, are
solved using a time marching method and a finite volume approach. The absolute flow is
computed in the nozzle vanes passage, whereas the relative flow is computed in the rotor
blades passage. The phase relation of nozzle and rotor flows and the related blade row
interaction are accounted for in the time-space domain. The results show that the present
method of calculation makes a practical contribution to predict actual turbine flows through
a turbine stage that have an arbitrary number of vanes and blades for each nozzle and rotor.
It is clear that this flow has a three dimensional aspects, in spite of the high hub/tip ratio
which has theoretically a two-dimensional flow aspects.

Neuro-Snake Pattern Recognition And Classification Using Gradiant Vector Flow (Gvf And Hnn)

Wissam Hassan Ali

Engineering and Technology Journal, 2009, Volume 27, Issue 5, Pages 973-982

The most popular applications of Hopfield neural network algorithm (HNN) are
pattern recognition and classification. But the HNN has some limitation like the local
minima (oscillation) problem. In this paper a novel method of combining an active
contour (snake) and an artificial neural network to behave together as pattern recognition
and classification is presented. The approach used the technique of the gradient vector
flow (GVF) that locate the boundary of target pattern (image) then pass it to a classifier
built by Hopfield algorithm to classify it according to one of the storage pattern. The
snakes can find the boundaries of objects so it is very accurate to take the shape of the
object wanted, that will eliminate the noise from the original image and reduce the bit
error rate of the Hopfield network to 0.215 and overcome the oscillation state in
recognition of the entered pattern. MATLAB 7 program have been used for the
simulation of the active contour and the pattern classification.

Sliding Mode Control For Gust Responses In Tall Building

Taghreed M. Mohammad Ridha; Farazdaq Rafeeq Yasien; Usama Yasien Mahmoud

Engineering and Technology Journal, 2009, Volume 27, Issue 5, Pages 983-992

The race toward new heights has led to the construction of tall flexible buildings
with low inherent structural damping. As buildings get taller their sensitivity to wind
excitations increases which threaten their integrity and serviceability. Therefore the control
of gust responses of tall buildings has gained worldwide attention. In this work an adaptive
Sliding Mode Control (SMC) driven Magneto Rheological (MR) fluid damper is proposed
for the vibration control problem of a wind excited tall building. The equivalent control part
proposed in this work is based on filtering the overall discontinuous control signal for a
better satisfaction of the reachability condition on one hand, and to heal the chattering
phenomenon on the other which is further reduced by replacing the hard switching sign
function by the sigmoid-like function. The adaptive tactic is based on using 3 second time
average variations of the gust speed to estimate the wind loading on the structure by
utilizing the theory of quasi-steady aerodynamics.

Corrosion of Copper in Deaerated and Oxygenated 0.1M H2SO4 Solutions under Controlled Conditions of Mass Transfer

Shatha A.Sameh; Issam K.Salih; Sadiq H.Alwash; AsawerAL-Waisty

Engineering and Technology Journal, 2009, Volume 27, Issue 5, Pages 993-1007

The corrosion behavior of copper in deaerated and oxygenated 0.1 H2SO4
solutions has been investigated using the rotating cylinder electrode under turbulent
flow conditions. Potentiostatic polarization measurements were carried out at different
bulk temperatures of 283, 288, 293 and 298 K and various speeds of rotation viz 100,
200, 300 and 400 r.p.m. The anodic dissolution of copper and the hydrogen evolution
reaction, in deaerated and oxygenated solutions, are activation controlled processes
dependent on the temperature of the solution. The anodic dissolution of copper is not
mass transfer controlled. The results are consistent with a mechanism which suggests
that oxidation of copper takes place in two steps of one electron each. The second step,
i.e., cuprous ion (Cu+) oxidation, is the rate controlling. Moreover, the mechanism of
hydrogen evolution reaction is a proton discharge upon the metal surface. The charge
transfer of the oxygen reduction reaction is a 2e process in the range of bulk
temperatures employed, i.e., the oxygen reduction is controlled by 2e process.
Furthermore, the limiting current density value of the oxygen reduction reaction
increases as the velocity of the fluid increases. The results, at a constant bulk
temperature are consistent with Eisenberg et al theory for mass transfer to a rotating
cylinder electrode surface

Recovery of PVA Using Polyethersulfone (PES) Hollow Fiber Ultrafiltration Membranes: Part II: Effect of Carboxymethyl Cellulose (CMC) Concentration

Najat J. Saleh; Amel Alhelaly; Jamal M. Ali; Qusay Alsalhy

Engineering and Technology Journal, 2009, Volume 27, Issue 5, Pages 1008-1016

Polyethersulfone (PES) hollow fiber ultrafiltration (UF) membrane with the molecular
weight cut-off (MWCO) 20,000 was used for the recovery of polyvinyl alcohol (PVA) from
the simulated wastewater. An attempt to study the effect of carboxymethyl cellulose as
synthetic warp sizing agents on the PVA recovery was investigated in this case.
Experimental results shown that PVA concentration in the retentate of PES hollow fiber
membrane were lower with addition of carboxymethyl cellulose (CMC) in PVA solution.
Besides, higher trans-membrane pressure from 1.0 to 2.1 bars, solution temperature 50-75℃,
and feed velocity 0.16-0.32 m/s, improved the PVA recovery in two different PVA solutions.
PES hollow fiber ultrafiltration process was efficient for PVA recovery from the simulated
wastewater using PVA solution with low carboxymethyl cellulose (CMC) concentration as
synthetic warp sizing agents.

Integrating Assembly Planning and Line Balancing Using Precedence Diagram

Bushra Basheer Abdulhasan

Engineering and Technology Journal, 2009, Volume 27, Issue 5, Pages 1017-1025

Traditionally, assembly planning and assembly line balancing are considered as
two independent tasks. Assembly planning represents a fundamental step in the operation
of a manufacturing system that involves product assembly while line balancing
represents one of the biggest technical problems in designing and operating a manual
assembly line. Although there have been several reported researches on assembly
planning for mechanical products, there is no available research on integration of
assembly planning and assembly line balancing.
In this paper, a methodology called COMSOAL-PLB (Computer Method of
Sequencing Operations for Assembly Lines of Assembly Planning and Line Balancing)
was developed to incorporate making decisions on process planning and production
planning for assembly product. Using ASIA-PLB, a planner or manufacturing engineer
can determine optimum or near optimum assembly sequence(s), optimum allocation the
task sets that will maximize the efficiency. The system has been tested on product(x) in
Seven Nissan Company. It resulted in reduction of idle time about 32%.

An experimental study of diverging angle effect on separation location in two - dimensional diffuser

Engineering and Technology Journal, 2009, Volume 27, Issue 5, Pages 157-170

The present study deals with flow of air in a two dimensional diffuser. A number
of test models of diffusers with different angles raging between (0◦ - 30◦) were
manufactured. The air was implemented as working fluid in the test with different
Reynolds number (6.85 × 104 – 1.64 × 105 ) at the duct inlet.
The study includes a number of experiments for air velocity and static pressure
measurement. The results showed the following:
1- Separation Phenomenon is obtained at divergent angles ( θ > 8◦) .
2- The location of separation delays by decreasing the divergent angle and by
increasing of Reynolds number.
3- The static pressure recovery coefficient decreases with the increasing diffuser area
ratio (AR).

Experimental study of Inclination angle and Surface Area Effects For Longitudinally Finned Cylinder on Free Convection Heat Transfer in an open Enclosure

Engineering and Technology Journal, 2009, Volume 27, Issue 5, Pages 171-180

This study deals with heat transfer by free convection from the outer surface of two
cylinders (Triangular & Rectangular shape fined cylinder 12-fins). The experimental
work was conducted with air as a heat transport medium. The cylinders were fixed at
different slope angles (0o, 30o, 60o, 90o) .The heat fluxes was (1310, 837, 470, 212, 53)
W/m2. Where heat transferred by convection and radiation. The results show that heat
transfer from the triangular finned cylinder is maximum at a slope angle (90o) and
minimum at the slope angle (0o) with the range from [Ra = (1.54*107 – 1.57*108)].

Effect of partial heat treatment on the mechanical properties of high carbon tool steel used in manufacturing active parts in cold work tool steel dies

Engineering and Technology Journal, 2009, Volume 27, Issue 5, Pages 181-189

Effect of partial heat treatment on the mechanical properties of high carbon tool steel used in manufacturing active parts in cold work tool steel dies was investigated in this work. High carbon alloy steel (X210Cr12) classified as
(QN1.2080) according to (DIN) was used for machining specimens with
dimensions (5×44×20mm).
(18) specimens were insulated from the middle to the end by graphite with (5mm)
thickness and (18) specimens were insulated by ceramic (Al2O3 + Kaolin) with
(5mm) thickness. The distance between the middle to the sharp edge was not
insulated. All these specimen were subjected to heat treatment, They show that can
obtain hardness (65HRC) for the sharp edge at (980oC) after the specimens were
quenched in oil. Stress relive was subjected to all specimens , it has been shown
during heating between (100-200oC) There is no big effect on the hardness and the
strength was increased, also when heating temperature increase up to (600 C ) the
hardness decrease at (30 HRC) .
Rockwell hardness test was employed to all specimens, at four locations
for each specimen. The first location is at distance (10mm) from the sharp edge and
the second at (20mm) from the sharp edge within un insulated part. The third
location is at (30mm) and the forth at (40mm) from the sharp edge within
insulated part.
The best values of hardness for the insulated specimen with graphite are
(65,64HRC) within the un insulated part and (47,48 HRC) within the insulated
part. For the specimen with ceramic insulation the hardness values are (65,64
HRC) within the un insulated part and (51,52 HRC) within the insulated part.
The results of this work was applied on the active parts of some press
working sheet metal dies, produced in central tool room plant/Nasser state
company, it has been shown that the life and fracture strength of these parts (punch,
die and stripper) were increased and improved.

Blended Learning in medicine collage

Engineering and Technology Journal, 2009, Volume 27, Issue 5, Pages 190-199

The university education Almtmazj model combines the traditional way of
education and the use of modern technology. And has many benefits, is to shorten the time, effort and cost, in addition to the possibility of improving the overall level of collection of curriculum, teaching and student assistance in providing attractive learning environment. Despite the importance of this type of education and the preliminary results that have proved successful, but the use is still in the offing
because of various difficulties and challenges. And must therefore define a vision for future employment in the educational process, and that education is Almtmazj one of the elements of this vision. The social awareness among community members the importance of this approach to education does not exist at various levels. There is a
need to review the educational environment in all stages of education, to conform to the requirements of university education. That knowledge is not the transfer of information from the student teaching, but how the student of this information and the environment in which they conduct the learning process, hence the importance of social awareness of the importance of information technology, the benefits of its
applications. Since many forms of e-learning and a variety of different circumstances and different parties involved in the learning process, such as distance learning, and learning in the classroom, will study the form of only one, a university medical schools Almtmazj using medical programs in addition to learning traditional education . The results showed a marked improvement in the utilization of information technology.

Effect Of Temperature On Gas Misaligned Journal Bearing Under Dynamic Loads

Engineering and Technology Journal, 2009, Volume 27, Issue 5, Pages 200-217

This study investigates the effect of a temperature on the
hydrodynamic lubrication of misaligned gas ( air ) journal bearing
under dynamic loads and study this effect on the distribution of the
pressure in the film of the air , components of misalignment moment ,
maximum value of pressure and minimum value of film thickness at
different value and distribution of temperature , degree of
misalignment and angle of misalignment .
The results show that the form of the pressure distribution is
a similar at different value of temperature and the components of
misalignment moment decrease with the rise of the temperature .
Also the maximum value of the pressure decrease and the minimum
value of film thickness increase with the rise of the temperature .