Engineering and Technology Journal

This study presents an experimental and nonlinear finite element analysis of
creating square openings in existing RC beams and strengthening with CFRP
laminate. Flexural strengthening of reinforced concrete beams is now becoming
more and more important in the field of structural maintenance and retrofitting. In
the experimental programming, three RC beams were cast. Two beams were tested
in the un-strengthened condition the first act as the solid Control beam, and the
other have openings, the third one have opening and strengthening with CFRP
laminate. The beams were also modeled using a FEM packaged (ANSYS 11). The
results indicate that the strengthened beam recorded the highest failure load and its
mode of failure was ductile. The numerical results seemed to be able to predict the
behavior of the beams

This research introduces the study carried out on one of Baghdad East
132/33/11(6.6) kV distribution substations to mitigate 50Hz magnetic field of
indoor distribution substation under normal operation. Shielding was performed at
the power sources such as busbars rather than at the affected areas. Threedimensional
finite element method (FEM) is used to calculate the magnetic field
density in the space nearby the busbars so as to analyze the shielding effectiveness
of an eddy current shield applied to a 132/33/11(6.6)kV substation. It also deals
with the influence of shield distance from busbar, thickness and material of shield
on the eddy current losses and shielding efficiency applied to 3D finite element
model of a particular busbar configuration

Numerical method is used to solve the two-dimensional transient natural
convection heat transfer problem in an inclined shallow porous cavity. A constant
heat flux is applied for heating and cooling all opposing walls. Solutions for laminar
case are obtained within Rayleigh number varied from 20 to 500 and aspect ratio for
porous cavity varied from 2 to 4. A finite difference method is used to obtain
numerical solutions of full governing equations. Energy equation is solved using
alternating direct implicit (ADI) method and stream function equation by successive
over relaxation (SOR) method. The results are presented for the flow filed,
temperature distributions, and average Nusselt number in terms of the Rayleigh
number, aspect ratio, and the inclination angle of cavity. the convection becomes
more and more vigorous as the orientation angle of the cavity is increased and for
high Rayligh number no steady unicellular flow could be maintained inside the
cavity. The effect of inclination angle on Nasselt number is more pronounced as the
Rayleigh number is increased. When the inclination angle increased the Nusselt
number increased and sudden transition appears and flow becomes unicellular and
Nusselt number increased clearly. The value of mean Nusselt number strong function
with the value of Rayleigh number, aspect ratio and the orientation of porous cavity

Axi-symmetric, steady, incompressible, turbulent flow field developed by natural
convection inside power plant solar chimney is investigated numerically using finite
volume method. Navier-Stockes with energy equation is solved to achieve velocity
components and temperature distribution inside solar chimney. To complete the
thermal analysis, conduction through upper glass wall, chimney concrete wall and
floor ground were investigated to calculate temperature distribution through theses
walls. A standard k - e turbulence model associated with lawss of the wall along
solid boundaries was used. Special arrangement for mesh was used to deal with
complicated shape of the domain. The main studied parameters are solar collector
diameter, kinds of ground, periphery heights and solar intensity radiation. This study
was compared with previous available experimental study and there is acceptable
agreement. The performance of the solar chimney was examined through maximum
air velocity in the tower inlet and maximum temperature in the ground floor. The
final optimization parameters are defined within studied ranges

In this study the ability of removing direct yellow 4 dye (DY4) from aqueous
solutions using silica as adsorbent was examined. The silica was prepared from locally
available sodium silicate. The effect of various experimental parameters contact time,
amount of silica used, pH, ionic strength and temperature were investigated in a batch
adsorption technique. The obtained experimental data shows that, the adsorption of direct
yellow 4 dye was increased directly with increasing concentration, amount of silica,
added sodium chloride and temperature in optimum pH (7) and equilibrium time of 45
min. The kinetic data were analyzed through pseudo first-order, pseudo second-order and
intraparticle diffusion models. The pseudo second-order model best represented
adsorption kinetics. Additionally, this study used the Langmuir, Freundlich and Temkin
isotherms to describe equilibrium adsorption and calculating thermodynamic values. The
equilibrium adsorption of direct yellow 4 on silica is best fitted in the Langmuir isotherm
(R2 =0.981).

The present research studies five spot welding electrodes (RSW) of different
geometries. The design of each electrode considerers contacts shape and area of the
welding spot. The considered welding electrodes are (Flat, Round, Project,
Punch\Flat, Cross Flat). A simplified mathematical 2D-axisymmetric model is used to
study the behavior of each electrode. It is solved numerically using Finite Element
Method (FEM). The model describes the nature of welding contact in terms of
contact locations, contact pressure and stress distribution. The model is validated by
performing tensile shear tests on the welded specimens resulted from each electrode.
Results show good agreement between the estimated behavior and the performed
tests. The strength of welding appeared to be proportional to welding time for all five
electrodes considered. The type (Project) gives the highest shear strength and the type
(Punch\Flat) gives the lowest shear strength. The tests show that the electrode of the
type (Punch\Flat) produces a hole in the welding area. This is caused by the electric
spark in the gap between the upper electrode and the plate. The same defect is noticed
in the type (Round). In both types, this phenomenon is attributed to the stress
concentration in a narrow area which eventually causes the punch.

The research presents an experimental study of the interaction between cavity
and adjacent pile in sandy soil. Experimental studies were performed to investigate
the effects of the different factors (such as cavity locations, batter angle of pile,
pulling height and vertical dead loads) on the lateral movements, rotations, and
ultimate lateral resistance of the pile for three states of soil (dry, water at rest and
water flowing laterally).
The analysis of the experimental results of the dry models indicate that the
model tests for very deep or shallow cavity with negative distance ratio( the
horizontal distance from the centerline of the pile to the centerline of the cavity,
S/B=-8) carries more load than the cavity case with positive distance ratio.
Different failure modes can be observed for each model tests depending upon the
geometry of the problem. The resistance of the batter pile are generally smaller
than that of the vertical pile case for cavity with ( depth of the cavity to length of
the pile, D/L=1 and S/B=0). Also for the same cavity location, the effects of lateral
load position on batter pile are very low. The pile with vertical dead load of (228.6
N) carries more lateral load than pile with no vertical load for the same cavity
condition. This behavior is reversed for soil without cavity. In spite of that the
constant lateral load is greater than the ultimate lateral resistance of the case
(F.S=0.8) during the observations of the lateral displacement with time, failure
does not occur for cavity condition with (D/L=0.5 and S/B=-8).
The results of the model tests with the presence of the water show the
methodology of the water flowing in the lateral load direction is more dangerous
on the pile stability than water at rest state for no cavity condition, but the water at
rest becomes very dangerous state for any cavity condition

Absorption of carbon dioxide in a bubble column by 0.5M Sodium Hydroxide
aqueous solution with and without various organic compound concentrations of
glucose, fructose and saccharose”0.05 , 0.2 , 0.4M” and various superficial gas
velocities “0.008 , 0.012 , 0.016 m/s” were studied in the present work.
The experiments were conducted under conditions in which the reaction of carbon
dioxide was of Pseudo-first order. The results show that the absorption rate enhances
with organic solute additive and increasing solute concentration

Ground-penetrating radar (GPR) technique was used at University of
Technology-Baghdad, as a non destructive, quick, low cost and powerful technique
in detecting any change in the constituents of subsurface as materials which can be
consequently applied in urban and constructed areas. The main objectives of this
study are: to simulate GPR data obtained by 250 and 500 MHz antennas for
shallow engineering investigation by detecting different subsurface bodies. A
simulation is made for GPR data with different geometric buried bodies and
located at different depth. Before processing, most of the raw data of radargram do
not reflect the presence of the buried bodies. But after processing by using suitable
filters and other interpretation tool parameters, many of the investigated subsurface
bodies and structures appeared clearly. It is found from this study that the degree of
clarity of the buried bodies do not depend on the higher value of dielectric constant
of the body, but it depends on the contrast between the body and the host medium.
Thus the body with low dielectric constant appears more clear than that with higher
dielectric constant, when they are at the same depth. Most of the buried bodies
appeared on GPR radargrams using the medium frequencies. The best detecting
depth are 1.5 m to 1 m for 250 and 500 MHz antennas respectively.

Fullerene molecule C60 was studied optimize structure, harmonic vibration
frequencies, infrared active vibration modes and some physical values in the
gaseous state theoretically by using Density function Theory (DFT), from view
animations of the mode displacement patterns, the infrared active vibration modes
can be classified theoretically to; Twisting vibration for (=C-C=C-) group at 510.0
cm-1, Wagging vibration for (=C-C=C-) group at 579.8 cm-1, Stretching vibration
for (C-C) bond in 1165.6 cm-1 and Stretching vibration for (C=C) bond at 1464.7
cm-1. These results were compared with other calculation data and experimental
measurements. Two from these modes are in good agreement with experimental
measurement while the two are nearly approach

Experimental research was conducted to investigate the structural behavior of
concrete-encased composite beams. Specimens were tested under lateral loading.
The test results indicate that the behavior and failure mode of the beam are greatly
affected by the steel beam core. The beams showed highly ductile behavior. The
design flexural strength of concrete-encased beams is calculated from both the
elastic and plastic stress distribution on the composite section. The deflection at the
mid-span of the beam cannot be well predicted using linear elastic theory.

The conversion of glycerol into value added chemicals have emerged in recent
years as a result of glycerol unique structure, properties, bioavailability, and
renewability. Glycerol is produced in large amounts during trans-esterification of
fatty acids into biodiesel, and as such represents a useful by-product.
In this paper, the liquid phase oxidation of glycerol has been studied over gold
nanoparticles supported on TiO2, and synthesized by using deposition-precipitation
method. The catalysts are characterized by XRD, TEM, XPS, and activity towards
CO oxidation. Active catalysts comprise particle size distributions (2-5 nm diameters)
for gold nanoparticles. The results indicate that the Au/TiO2 catalyst showed the best
performances both for activity and selectivity toward glyceric acid. We have also
studied the effect of reaction conditions such as, amount of catalyst and concentration
of base in the catalytic activity

Field oriented control (FOC) method of an induction motor (IM), allows high
performance speed and torque response to be achieved from an induction motor.
The present work selects the direct field orientation control induction motor
(DFOCIM) as an effective method for eliminating the coupling effect between
torque and flux. In the present work, two schemes of estimators have been used,
standard kalman filter (SKF) and Extended kalman filter (EKF) for estimating
stator current, rotor flux and rotor speed. The performance comparison is based on
evaluation of estimation error of both estimators. The performances of suggested
estimators are assessed in terms of tracking performance and noise rejection
capability.

The current study concerns with studying some mechanical and physical properties
of different samples taken from Unplasticized Polyvinyl Chloride (UPVC) pipes used
in sewage purpose. Impact strength, compressive strength, shore-D hardness, and
diffusion coefficient also were calculated for the samples immersed in different
solutions (Wastewater, HCl-0.5N, and Tape water) for four months. Results showed
that the mechanical properties of samples were affected by solutions and reduced by (3
– 5)% for impact strength and (10%) for compressive strength. Values for diffusion
coefficient (D) were calculated, it
was found that (HCl-0.5N) had a higher value, followed by wastewater then tape
water. No cracks were observed, and there were no changes in sample’s dimensions
after immersion in solutions.

Bills of Quantities (B.Q) considered as one of the important project documents in
addition to the contract form and the exchanged official letters between the two main
contract parties before signing a contract. Quantities estimation performed through two
stages, the first is to determine measurements from design drawings to find length,
number, area, and volume, for each group of works, its related units in an organized
manner prior to the preparation of the required (B.Q). The responsible party of preparing
(B.Q) should be aware in all estimating methods and have wide and detailed information
about building materials, construction methods, site conditions, and prices changing with
time.
Due to the lack of accuracy, organizing, and standard specification of the existing
(B.Q) which prepared by different public and privet contracting companies and that
observed through this research, therefore there is clear importance to establish reform
system for the prepared (B.Q).Through theoretical, field investigation and studies,
several factors affecting the accuracy of (B.Q) are concluded by this research.
Deficiencies in (B.Q) are the result of the responsible party lack of awareness' regarding
the concluded factors.
The researcher established computer program to simulate the effecting factors on
accuracy of (B.Q) and recommend the required reformation to each examined case. The
research recommended that (B.Q) preparing parties to consider all concluded affecting
factors or at least the very effecting ones and to adopt the proposed system for reforming
their prepared (B.Q).