Iraqi journal of mechanical and material engineering

The objective of this research is to study the effect the change of reinforcement
percentage by fibers on the thermal conductivity for polymeric composite material
consist of conbextra epoxy (EP-10) resin reinforced by biaxial woven roving S–type
glass fibers (٠º-٤٥º) with density (550 g/cm2) where we used different percentage of
fibers reinforcement to the resin (20%,40%,60%,80%) and studied the influence that on
thermal conductivity for composite material due to this change, and we used Fourier equation to calculate the thermal conductivity coefficient (k),and we used
reinforcement percentages (20%,40%,60%) to reinforced the mechanical tests
specimens to calculated impact strength, tensile strength, flexural strength as illustrated
in diagrams which represent the relation between thermal conductivity coefficient (k)
with temperature and between mechanical properties and reinforcement percentages.

This paper investigates the analysis of residential water demand for the city of
Hilla which is the main town in Babylon government in Iraq( Population of about
258568 person , living in an area of 55 Km2 according to Central Committee of
Statistics – Babylon Census Directorate -1997) along with determining the factors that
affect such demand for the period from the 1st of January to the end of August -2004.
The cross-section data which was weekly observed was collected by a survey
made on a sample of randomly chosen dwellings from different districts of the city.
A questionnaire survey was also made to collect all necessary information
seemed useful in estimating the daily consumption of domestic water.
Demand relations are estimated for total residential, winter, summer, and
Sprinkling demands.
Stepwise multiple regression analysis was employed to find the structural
relationship between water demand per household per day and household
characteristics (factors) for each type of demand.
All demand models were fitted in log-linear form.
In this survey, the average daily water demand for the city of Hilla was
estimated to be 1721 L/h/d (273.2L/c/d) for total model, 586.13 L/h/d ( 93L/c/d) for
winter model , 2453 L/h/d( 389.4L/c/d) for summer model and 490 L/h/d(77.8L/c/d) for
sprinkling model.
The most significant factors affecting the demand appear in the fitted equation.
Of these factors, household size was found to be significant variable in all demand
models, while number of washbasins variable was found to be the significant variable
in the total, winter, and summer model. The total built –up area of the house and
number of showers was found to be the significant variables in the total and summer
models.

This paper illustrates the analysis and simulation of narrow band antenna arrays
with adapted radiation pattern using digital beamformation. The technique used for the
system is the Shifted Sideband Beamformer (SSB). This paper analyzes the stages of
the receiver and presents a model for simulation. The SSB was chosen because it
exhibits moderate complexity and storage requirement. Different spatial filters such as
Uniform weight, Blackman-Harris, Tylor, and Dolph-Chebyshev were used to control
the side lobe level of the arrays. This paper also shows how to implement null steering
procedure to circumvent the jamming and high interference angles. Only the linear and
two dimensional arrays were taken into consideration.

The architectural studies consider as part of cognitive studies in most of worldly
universities .The investigation includes six final projects from both countries. The
comparative study is made between these two samples which are artistic presentation
point of view and the scientific point of view. The former includes the efficiency of
presentation, colours and writings. While the latter includes the type of design whether
it is urban design or single buildings, way of thinking i:e input, output, diagrams,
analysis, human and visual scales, details about the used materials and drawings, type
of structure land scapins.) Which consider as determiners in architecture engineering on
the basisis that architecture is a mixture of since and art.
The researcher propose that there are many differences in the syllabuses ,
customs , circumstances and other technical materials of the two countries. The study
has got by using the analysis on the description of the samples results which denote that
there are differences in comparative elements. Then we have got different
conclusions with respect of two groups of samples.

An experimental study to investigate the effect of the particle size (dp) and
Reynolds number (Re) for different values of heat flux on the heat transfer coefficient
(h) in gas-solid fluidized bed was done.
In this work three different sizes of sand particles were employed (525,725 and
925μ m ). The fluidizing medium was air at different velocities in the range of (1.9-2.9
m/s). The rig provided with a horizontal heating tube with outer diameter of (3.175cm)
was heated eclectically with different power supplies (69,90,120 and 150 W) .
The fluidized bed temperature profiles were evaluated axially in the fluidized bed
for different positions. The recording and the monitoring of these measurements were
done by an interface system connected with PC computer.
The results show that the temperature distribution decreases with increase particle
size and the heat flux represents as the temperature increases as the air velocities
increase .
A new empirical correlation was suggested in this study .The correlation
predicts the value of (Nup) as a function of both (Rep) and (Frp). All the dimensionless
groups are determined based on particle diameter .

This paper presents the application of Simulated Annealing optimization
method (SA) for solving the problem of the optimum design of reinforced concrete
beams based on the recommendations of American Building Code Requirements for
structural concrete (ACI 318-05) and the ultimate strength design method. Cost of
concrete, cost of steel reinforcement and cost of formworks are considered. The
constraints of the problem included the concrete beam strength, width-height ratio,
minimum width, and deflection constraints. This optimization problem is implemented
by constructing a computer program using Matlab. A number of examples are solved
using the developed program and proved that the produced design is economical; also it
is proved that the developed program is efficient and versatile.

The present study deals with an investigation of dry sliding wear behaviour of
grain refined and or modified (Al–20Si) alloy by using a Pin-On-Disc. The refining
was by grain refinements (Ti and B), modification (Sr, Na and P) and combined action
of both (Ti, B + P +chilling). Results indicate that combined grain refined and modified
Al-20Si alloys have microstructures consisting of uniformly distributed α-Al grains,
eutectic Al–silicon and fine primary Si - particles in the interdendritic region. These
alloys (5,6) exhibited better wear resistance (13-15 times) than the same alloy subjected
to only grain refinement or modification (1, 2 and 3) . The improved wear resistances
are related to the refinement of the aluminum grain size, uniform distribution of fine
fibrous eutectic Al–silicon and fine primary Si- particles.

This work aims to study the effect of the heat treatment (precipitation
hardening) on microstructure and corrosion parameters of two alloys (Al- 4%Cu) and
(Al- 4.1%Cu- 0.9%Mg). They were prepared by melting and casting in a metallic mold.
Hot rolling at 450C° was carried out on ingots by 50% deformation of two alloys to get
sheets. Many tests were conducted on these prepared alloys of cast and wrought
conditions, including microstructure and hardness and corrosion test. Precipitation heat
treatment was carried out which included solution heat treatment at 515C° and aging.
Two types of aging, artificial aging at 190C° for 3hr and natural aging at 25C° for 7
days were carried out on prepared alloys in order to indicate the effect of these heat
treatments on the microstructure and hardness. Electrochemical corrosion test by Tafel
extrapolation method was carried out on all prepared samples of alloys in sodium
chloride solution of 3.5% NaCl (PH=8.2) to determine corrosion parameters. such as
corrosion potential ( Ecorr. ),corrosion current ( Icorr.) and corrosion rate (mpy). The
results show that the corrosion rate of cast samples and homogenized treated was lower
than that of wrought samples of two alloys (Al- 4%Cu) and (Al- 4.1%Cu- 0.9%Mg) in
salt solution at room temperature. Precipitation heat treatment and artificial aging at
190C° for both cast and wrought conditions lead to increase corrosion rate. The results
also show that the addition of Mg to (Al-4%Cu) alloys reduce corrosion current
density( Icorr.) and corrosion potential (Ecorr) shifts to more noble direction in 3.5%
NaCl solution for two alloys in cast and wrought conditions.

In this study flexural behavior and shear strength of reinforced concrete beams
made of normal strength concrete (NSC) and high performance concrete (HPC) with
compressive strength (30,78) MPa respectively at (28) days age, and assessing the
residual flexural and shear strengths after exposure to fire flame.
The concrete specimens were subjected to fire flame at temperature levels of
(400 ºC) and (700 ºC) at two periods of exposure (1, 1.5) hour then cooled either by air
and water. Firing and testing the beam specimens were conducted at age of (60) days.
Results indicate remarkable reduction in flexural and shear strengths after
exposure to fire flame. The residual flexural strength is (84- 88%), (70- 72%) for HPC,
and (86- 91%), (84- 88%) for NSC with (1.0) and (1.5) hour exposure periods
respectively at fire temperature (400 ºC), while the residual at fire temperature (700 ºC) is
(50-58%), (37-38%) for HPC, and (53-60%), (26-41%) for NSC with (1.0) and (1.5)
hour exposure periods 93%), (75- 77%) for NSC with (1.0) and (1.5) hour exposure
periods respectively at fire temperature (400 ºC), while the residual at fire temperature
(700 ºC) is (50-55%), (40-45%) for HPC, and (54-57%), (38-46%) for NSC with (1.0)
and (1.5) hour exposure periods respectively.

Abstract
Cinter of karbala damaged during the demolition of the events in 1991 especially
areas near the Imam Hussein ,peace be upon him and his brother Abbas .
Demolition has been left unused space and lack of visual and organic link with the rest
of the city near or far from it …
The removal of a link between Almrkadin surrounding them has led to the removal of
many services ,disturbing the movement of vehicles and pedestrians in the city .
The mayor of karbala ,the implementation of the directorates of concrete fence to cover
these areas ,dilapidated and led to distor the appearance of the city urban and the
negative visual impact and Almrkadin and their surrounding in .
Addition to isolate them from the city which the free space that have emerged between
Almrkadin and their axes ,some of the main streets led to the loss of the human
standered for urban design to address the realities,so there was aneed for the
preparation of city.

This research deals with the flexural behavior of partially end restrained slabs
subjected to burning by fire flame. The investigation is based on casting and testing 16
reduced scale (600×600×40mm) reinforced concrete slab specimens. Two concrete
mixes with design 28 days compressive strengths of (30 and 38 MPa) were adopted.
Two steel ratios of (0.005, 0.009) were used. The specimens were exposed to fire flame
temperature levels of (400,500 and 600°C) at the lower surface of the slab specimens
with exposure duration of one hour, then after 24 hours; they were tested in flexure to
failure under uniformly distributed load while they are partially edge restrained against
lateral and rotational movements.
It was found from the results that the values of ultimate load capacity, decreased
for all specimens after exposing to fire flame. The residual ultimate load capacity for
specimens burnt at temperatures of (400 and 500°C) was higher than that for specimens
burnt at 600°C. At temperature around 600°C and for steel ratios of (0.005 and 0.009),
the percentages of residual ultimate load ranged between (85 and 87%) respectively.
The residual compressive strength at 600°C was about (63 %). However the residual
modulus of rupture was in the range of (47 and 51 %) and the residual modulus of
elasticity ranged between (29 and 26%) at 600ºC.