DIYALA JOURNAL OF ENGINEERING SCIENCES

The heat transfer process involved in the curing of fiber-reinforced
thermosetting composites is investigated numerically. This composite is made of woven fiber
and resin and placed in a cylindrical mould. The governing equation for one dimensional heat
transfer, and accounting for the heat generation due to the exothermic cure reaction in the
composites had been used. A finite element method is developed to solve the mathematical
model problems for composites manufacturing. The solution of the complete mathematical
system gives, both, the temperature and the degree of reaction as functions of time and
position. It was found that the temperature at the central of the sample increases up to the
external imposed temperature, because of the thermal conductivity of the resin and fiber. The
heat generated by the exothermic reaction of the resin is not adequately removed; the increase
in the temperature at the center increases the resins rate reaction, which in turn generates
more heat.

An analytical model with sufficiently non linear kinematics to capture the
development in engineering applications to resist bending stress for thin walled elasticplastic
steel tubes which used as structural members. The results indicate that collapse of
such tubes is imperfection sensitive for tubes with height to thickness ratio (h/t), but the
sensitivity decreases as the ratio decreases. Experimentally, the tubes collapse due a limit
moment instability which is followed by the formation of a kink on the compression flange of
the tubes. The present research removes the limitation in the pre- bifurcation analysis and
concentrates on the numerical prediction ANSYS -11 program of the response with stress and
strain distribution on thin walled tubes of square cross section. The numerical, analytical and
experimental results are converges to each other, by simulating the response of square tubes
subjected to static and dynamic axial bending loading .The finite element models used for
this work are featured by the geo-metric and material characteristics of square tubes and
comparison of the computed bending response to the results and findings of the experimental
works shows that the finite element models described here, approached the actual bending
response of the square tubes to a satisfactory degree both in terms of collapse modes and
main bending characteristics such as bending stress and strain and deformation displacement.

Removal of Methylene Blue (MB) from aqueous solutions using Yemen
bentonite as low-cost adsorbent have been studied as a function of temperature, particle size
and solution pH . The adsorption capacity increased with increasing temperature (15 to 45˚C
) and solution pH value (2 to 12) and decreasing particle size (500-710 to 80-125). The
maximum adsorption capacity was 500.0 (mg.g-1) at T = 25˚C, dp = 250-355 μm and pH = 12.
The experimental data were analyzed by Langmuir, Freundlich, Temkin and Redlich-Peterson
isotherms, and found that the Redlich-Peterson isotherm best fit the experimental data over
the whole concentration range with R2 values lie between 0.9986 and 0.9999. Thermodynamic
parameters such as standard Gibbs free energy (ΔG˚), standard enthalpy (ΔH˚), and standard
entropy (ΔS˚) were calculated. The thermodynamic parameters of MB/clay system indicated
spontaneous and endothermic nature of the adsorption process. The results demonstrate that
Yemen bentonite is effective in the removal of MB from aqueous solutions and can be used as
alternative of high cost commercial adsorbents.

The influence of apex angle on mixed convection in a horizontal porous
sector channel is investigated. The analysis is performed by considering fully- developed
hydrodynamically and thermally flow. The governing equations have been solved
numerically using finite difference method. The channel is heated from the right surface, and
cooled from the left one –both are held at constant temperature- while the top surface is
adiabatic. The numerical analysis has been conducted in the following range of parameters:
radius of the sector=4, (Pe=20), (Ra*=100 and 1000), the apex angle (Φ=30o, 60o, 75o and
90o). The results are presented to demonstrate the effect of increasing the apex angle on the
streamlines, the isotherms and local Nusselt number. The highest stream function appears in a
specified apex angle depending on Ra*. The local Nusselt number values are decreasing as
the apex angle is increasing at (Ra*=1000), while at (Ra*=100) its values are increasing as the
apex angle is increasing. A correlating equation is suggested to correlate (Nu ) against apex
angle (Φ) and (Ra*) for (Pe=20).

Gypseous soil is one of problematic soils facing civil engineer. The
problem appears when constructing heavy buildings or hydraulic structures on these soils
after wetted by water from rainfall or from the raising of water table level from any source.
On the other hand gypseous soil is considerably strong and has good properties when it
is dry. The dissolution of gypsum depends on many factors: gypsum content, temperature,
atmospheric pressure and others. Number of Remedies for these soils was carried out by
many investigators, some of these methods are not workable, and the others are expansive.
A new method of improving the collapsibility of such soil was presented by
Prewetting Gypseous soil with water many cycles using laboratory and field models with
different footing stress, which reduces the collapsibility of this soil primary. A laboratory
model of 320 mm diameter and 472 mm height made from thick plastic was used. Two soils
with different gypsum content 50% and 70%, brought from Aldor and Balad, in Salah Al
Deen government in Iraq, was used. A footing of circular base (50 mm diameter), applies 45
kN/m2 and 100kN/m2 stresses with the aid of fix weights placed on it. The results of
laboratory tests on the model samples shows a considerable reduction percent in the
deformation ratio (Settlement/width of footing (S/B)) of 63% achieved from the 3rd wetting
cycle by water for sample contain 50% gypsum. The reduction percent was 91% at the 3rd
cycle of prewetting for sample containing 70% gypsum tested at stress level up to 45kN/m2,
while it is 86% for the laboratory model with 100kN/m2 applied stress, with the same gypsum
content. The results of field test for the soil containing70% gypsum tested at 100kN/m2 stress
shows a pronounce improvement in the S/B value which gives a reduction percent reaches 90
%, which shows a considerable improvement in the collapsibility of this problematic soil.

In variable speed drive (VSD), it is desirable to reduce the harmonic
effects, which causes current distortion and torque pulsation, besides, the harmonic power
losses is an additional power losses that is introduced in the motor due to the presence of
harmonic voltages.
However, the problem of the high total harmonic current distortion (THD) still exists
specially at low and medium speeds by using sub-optimal pulse width modulation (PWM)
strategy. In the past to generate optimized PWM, is done by defining a general PWM in terms
of a set of switching angles. Which result in a set of nonlinear equations in terms of the
unknown switching angles. These equations are nonlinear as well as transcendental in nature.
There is no efficient method that can be applied to solve such equations. The practical
method of solving these equations is a trial and error process. Taking all the factors into
account, a numerical technique can be applied to solve these set of nonlinear equations, but
with some limitations.
To overcome these limitations, Genetic algorithms (GAs) serves to search for optimal
switching angles setting. In addition, the (THD) will be reduced, this lead to obtain the
optimal PWM waveform and to simplify the practical implementation, and then improving
the performance of the system output.
GAs were employed as a search and optimization engine. Normally the tuning of the
switching angles is a trail and error problem.
In this paper, GAs provides a much simpler approach to off-line tuning of PWM
switching angles than the rather complicated non-genetic optimization algorithms.

This study is conducted to investigate experimentally the punching shear
and flexural strengths of reinforced concrete flat plate slabs made with Non-Rectangular
(triangular and trapezoidal) shaped. Four test self-compacting concrete slab groups were
manufactured, each of which consisted of three slab specimens identical in size and shape but
different in constituent’s properties. All slabs are simply supported along the all edges and
subjected to single point load applied at the center of gravity of each slab.
Experimental results shows that the use of self compacting concrete improves the
punching shear resistance and allows higher forces to be transferred through the slab-column
connection. For slabs which were designed to fail in punching shear, the ultimate capacity of
the tested specimens increased by (7%) to (20%) when the shape of slab specimens changed
from triangular to trapezoidal. In contrast of slabs which were designed to fail in flexure, the
ultimate capacity of the tested specimens increased from (16%) to (58%) when the shape of
slab specimens changed from triangular to trapezoidal.
The cracking load depends essentially on concrete strength and not on slab
configuration, but, the ultimate capacity depends on both, concrete strength and shape of slab

In this work, a suggested algorithm is designed that operates at ATM
Adaptation Layer (AAL) layer, this algorithm is named Adding Identification number and
Matching (AIDM) algorithm. The resulting transport protocol from using AIDM algorithm is
named as Improved TCP/IP Reno. AIDM is an efficient recovering technique that attempts to
make TCP\IP Reno performance less sensitive to cell losses. Improve TCP/IP Reno is
presented and a result is compared with other TCP\IP Reno .This result explain the network
performance is enhanced about 20.53 % as average of the enhancement rates of the given
samples and the period of time required to recover the damaged cell is reduce .

Non-linear analysis of continuous composite concrete–steel beams under
cyclic loadings has been investigated in this paper. A three-dimensional finite element
analysis (FE) ANSYS computer program(ANSYS version 9.0) was conducted to investigate
the nonlinear behaviour of this beam up to failure through the prediction of the values of slip,
deflection along the spans of the composite beam for different number of loading cycles up to
one million cycles of the load of range (52%of the ultimate load of the beam). The results
obtained from analyzing a continuous composite concrete-steel beam under cyclic loadings
show good agreement with available experimental results and other available analytical
results. A parametric study is also conducted in this paper to study the influence of some
parameters such as the number of loading cycles, and the amount of load ratio on the values
of slip and deflection. This parametric study shows that as the number of loading cycles
increased, slip and deflection values along the composite beam will increased due to
reduction in strength of all components of the composite beam, and the absolute values of
maximum slip and maximum deflection will reduce as the load ratio changes from negative
to positive signs .

Theoretical and experimental study of heat transfer steady natural
convection from the cylinder embedded in a saturated porous media was cared out. the
theoretical part of the work includes the derivation of the governing momentum and energy
equation by using Darcy flow model. The two equations are solved by finite difference
method with constant cylinder surface temperature, with a Peclet number under steady
condition and Rayleigh number ranged between (10 work included the construction of an experimental model composed of iron cylinder with a
(12mm) in diameter heated internally by an electrical source. The cylinder was embedded in
a packing of glass with diameter (12mm) placed in a test section. Both the theoretical and
the experimental results revealed that the average heat transfer increased when the Rayleigh
increased. The relationship between Na&Ra for both experimental and theoretical are give us
Nu=4.311lnRa-11.1 and Nu=2.155 lnRa-3.98 respectively

This research aims to develop some mechanical properties for carbon steel
(CK38) ductility ,yield stress ,shear stress ,ultimate stress ,fracture stress and impact strength
) at quenching (15) samples testing for every tensile and intact tests in dissociated engine oil
medium with circulating and tempering at 260 oC , 460 oC and 650 oC temperature) , ( 3)
samples testing for every tempering temperature) , (5) for hardness and one for chemicals
composition . then compare mechanical properties before and after heat treatment to show if
we can use it in much and important The results after heat treatment show increase in
ductility ,yield stress ,shear stress ,ultimate stress ,fracture stress ,impact strength , static and
dynamic energy

The research handles the measuring of functional efficiency in the modern
Iraqi city taking Mosul city as a good example of this study, the problem of (lacking
resources involved in the field of evaluating the functional efficiency of the modern houses
spaces locally) was put on the table of discussion.
The theory depended by the research is represented by (the functional efficiency of
any building is affected by the space arranging of the involved building) , tow main aims
were achieved by the research, the first is represented by (evaluating the functional efficiency
of the modern houses spaces locally) the second is concerned with (the possibility of
reaching a sample of a space system concerned with the modern spaces houses in such a way
that keep it functionally efficient as long as possible).
Doing so, it was possible to deal with one of the mathematical analysis methods using
a computing program which is (syntax.exe), it provides us with a digital results so precise in
analysis, in order to obtain the data, selected samples of modern houses were selected and
analyzing them by space syntax theory indicators.
Once the theory was selected and the results were obtained, the research made several
results by which many questions found their answers, these questions which were mentioned
at the beginning of the research are:-
1. How can we collect the functional efficiency with the house space systematizing?
2. Is it possible to reach a sample of house in which the space systematizing can be
effective in such way with the functional efficiency?
3. Is it possible to apply the dependant method in the analyzing on a different other
space system of houses that are of different times or even of buildings that are of nonresidential
functions?
Answering these questions, the research realized that the house, as a functional
system, containing all of the actions, is still lacking to the succeeding qualifications unless
having these functions with certain indicators of the Space arranging that are contributing in
some way in evaluating the functional efficiency of that house.