AL-Rafidain Engineering Journal (AREJ)

In this research, a functionally graded polymeric matrix composites
(FGPMCs) were produced using centrifugal casting method. These composites were
fabricated from unsaturated polyester resin as a matrix and reinforced with silicon
carbide particles (SiCp) of (106μm) and (6%)bulk volume fraction, using different mold
rotational speeds(400,500,600 R.P.M) at room temperature (22Cº). Additional (3)
samples of pure polyester were manufactured at the same conditions for comparison
purpose . The aim of the present research was to study the effect of mold rotational
speed on local values of volume fraction, hardness and Young modulus at specific points
along the graded samples. Hardness was measured at these points then graded samples
were cut to eight portions . Density and volume fraction were evaluated, then standard
homogenous samples of constant but different volume fraction were manufactured.
Results shows that local values of volume fraction, hardness and Young Modulus
decreased in nearby positions of the center of rotation and increased in positions far
away from the center of rotation with increasing mold rotational speed.

A study was conducted for the purpose of determining the stresses generated on the
draw-bar as a result of different types of soil and depth produced during plowing
process in two different soils.
Laboratory analysis was conducted for studying the soil analysis in the department of
Civil Engineering University of Mosul.
Analysis revealed that there were two different types of soil (clay and mixed). At the
same time mechanical properties and basic measurements of draw-bar was carried out.
At the same time stress analysis of draw-bar was done using finite elements program
(Ansys releases 14.0 types), to determine the properties during application in different
stress analysis parameters where used (x, y, z) and Von
Mises in addition to principal stresses and percentage deviation of the direction of the
three axes (x, y, z).
During practical phrase, installation of strain gauges on draw-bar was done , for two
types of soil at different depth level factors using three level (40, 45, 50) cm.
The present results revealed that there was a difference in the stress values generated in
relation to depth and types of soil.

The main objective of this investigation is to obtain performance efficiency and
the coefficient of discharge for Piano Key weir with downstream overhang. One hundred
thirty five experiments were conducted on models of Piano key weirs. Three slope of the inlet
key (Si = 0.7, 0.6, 0.46), three different ratios for the inlet key width to the out let key width
(Wi/Wo= 1, 1.61, 1.81) and three heights (p = 30, 25, 20) cm for each weir were used. The results showed that the slope of the inlet key (0.7) gave a lower values of performance efficiency and a highest values of coefficient of discharge than (0.6, 0.46) keys while ratios of inlet key width to the out let key width (Wi/Wo = 1.81) gave a highest values of coefficient of discharge. An empirical relationship was found for estimate the coefficient of discharge and performance efficiency in relation to the non dimensionless variable

In this study, Hydrus-1D model was used to simulate the evaporation from
the soil surface for different wetting intervals for northern region(sandy loam and clay
loam) using input for climatic data , and data of class A pan evaporation. The results
showed that data of pan evaporation class A can be relied on in simulating and
calculation of evaporation from the soil surface, where the standards of statistics (IOA,
R2) calculated on the basis of evaporation pan class A data are better for the wetting
intervals (2, 4, 8, 16 ) days compared with the values of those standards based on full
climate data and both types of soil. The study also showed that the wetting intervals and
their impact on evaporation from the soil surface and evaporation stages reasonably
agree with the results of field experiments that have been made in this area.

A hardware architecture implementation of Advanced Encryption Standard (AES) is
globally adopted to encrypt data for variant communications systems, taking into
account that AES is reliable, secured and immunized against attacks. A single crypto
system is suggested to encrypt and/or decrypt different types of data .These types of
data are assumed to be as a text data .The image is considered as a case study for the
type of data that is to be encrypted in real time. Then the proposed architectures are
used to encrypt the video within the time ≤ 33 m sec . Two architectures are proposed .
The first one is a hybrid of both stream and block ciphering. This architecture is used to
increase the encryption security by reducing the correlation among image pixels. The
resulting encryption time for an image of (32x64) pixels is equal to 16.76 μ sec. The
second architecture is proposed for CTR mode of AES algorithm. The same time
achieved in the first architecture is also achieved in this implementation. However ,the
half of the hardware resources in comparison with the first architecture is achieved in
implementing the second, but if it is used for either encryption or decryption , not for
both simultaneity. The real time implementation is achieved due to using parallel
computation that is based on pipelining technique. The architecture are synthesized on
Spartan-6 LX(XC6SLX16) using ISE 14.2 .

The study aimed to apply the concept of Ballasted Flocculation (BF) at modified
jar test for different turbidities for Tigris rivers raw water in order to find out the
optimum values for each of :the additives chemicals, the ballasted agent doses and the
operating conditions which are each of the detention time and velocity gradient
A study of 366 samples for six levels of initial synthetic turbidity of the Tigris
River showed that it is possible to adopt BF technique successfully, and it reduces the
time of the treatment phase and increase the stability of the quality of water treatment,
but does not reduce the concentrations of the chemicals which are used. The study shows
that the use of alum concentration of 30-40 mg/L with polymer concentration of 0.2-0.4
mg/L and BA concentration of 0.5-2.5 g/L for the range of diameters between 75-212 μm
achieve a residual turbidity ~1 NTU for supernatant water.

The socially sustainable school is an emergent concept appeared within the context of
many significant changes in the world schools’ designs. Also, the functional performance
is considered as a principal constituent for the socially sustainable schools. On the other
hand, Iraqi schools are suffering, generally, from being of low functional performance; a
problem resulted, as this research believes, from certain forms of considering the spatial
adjacency and syntactic properties which are the most influencing factors for the
schools’ functional performance. This research tackles the problem that there are no
clear conceptions about the extent and how those properties are considered in the design
practices of the Iraqi elementary schools. It adopts the objective of defining these
conceptions using a method which includes defining the related influencing spatial
adjacency and syntactic properties firstly, then measuring to what extent and how the
defined properties are considered in the designs of Iraqi schools in comparision with the
world design practice framed by the general theory of the socially sustainable schools.
After discussing the results, the final conclusions which define the weaknesses and
defecits of the local schools’ design practices regarding the consideration of the
properties of interest are presented.

In the design stage or analysis of any dynamical system a detailed or
comprehensive model is essentially required. In this work, different parts and
components that are contained in the model of a turbo-generator unit (T.G) for torsional
vibration analysis are considered and the governing equations of which are presented
and developed to estimate their respective parameters. These parts and components are
mainly compressor seventeen stages and blades, turbine two stages and blades,
reduction gear system with the safety shaft, the rotor of the generator, the exciter and
the fluid film bearings on which the whole system is supported. The data upon which the
system model is built are referred to Mosul gas turbine station units. The estimated
parameters are those related to rotational inertia, damping and stiffness effects of the
different components in the system. A detailed model of the system should be useful for
the purpose of torsional vibrational during rotation with normal steady loading or
under severe loading conditions utilizing a block diagram via Matlab. The system eigen
values natural frequencies (critical speeds) and mode shapes are determined

In this investigation , natural convection heat transfer from a heater placed on
the bottom of a square enclosure with adjacent inclined wall was carried out . The
inclined wall has a constant low temperature , while the heater element has a constant
high temperature ,and the remaining walls are insulated . The working fluid used is air
with Prandtl number (Pr=0.72) . The governing equations of the problem are solved
numerically by using finite difference method . The numerical solution is presented for
various Rayligh numbers, Ra(103-105) , with different dimensionless parameters as
length of heater (Yh) (0.1,0.3,0.5), different locations of the heater (Xh) (0.25,0.5) and
inclination angle of inclined cold wall  (10o, 20o, 30o). The results are presented by
isotherms and streamlines to show the behavior of the flow and temperature distribution
. While the numerical results of heat transfer are presented by average Nusselt number
and local Nusselt numbers at right , left and top sides of heater. The results show the
effect of dimensionless parameters on heat transfer and Nusselt number. It is observed
that the Nusselt number increased by increasing Raylig number , heater length ,
inclination angle of cold wall and where the heater is near the cold wall (Xh=0.5).

This research deals with the optimum design of the heat pipe components using
Matlab program, version 7, at the determined operating conditions. The heat pipe is
used to transfer maximum available thermal energy to heat the feed water entering
steam boiler .
The affecting parameters on heat pipe performance were detailed as well as the
transport limitations and the thermal resistances of the heat pipe parts. Satisfactory
results were obtained for the heat pipe dimensions, components and design influentials.
Also, the parameters affecting the heat transfer rate and the working fluid mass-flow
rate were discussed. From the important results, the heat pipe heat transfer capability is
directly proportional with each of the heat pipe bore, the wick c/s area and the heat pipe
effective length, and inversely with each of the capillary radius and the working fluid
viscosity.

Copper is one of the few metals with significant commercial uses. Although frequently used as a pure metal or with small amounts of metal additives, copper can form 82 binary alloys. Two of the most common are brass (copper-zinc) and bronze (copper-tin). This research work tries to study the ultrasonic behaviour in one of the important brass alloys represented by (α + β`) brass alloy.
Specimens of (α + β`) brass were machined to cylindrical shape with different thicknesses in order to study the effect of the sound scanning distance on the acoustic attenuation of the ultrasonic waves.
The results indicate that it is plausible to inspect (α + β`) brass using both 2MHz and 4MHz frequencies, and that the acoustic attenuation of ultrasonic waves has increased when 4MHz probe was used. In addition, the results illustrate that the acoustic attenuation increases as the sound path distance increases.

In this paper, a neuro-fuzzy classification method is used for identifications of ECG
signals. A feature extraction method with a QRS like filter (first order Gaussian
derivative filter) is used. Five standard parameters (energy, mean value, standard
deviation, maximum and minimum) are extracted from these disease features and then
used as inputs for the neuro-fuzzy classification system. The ECG signals are imported
from the standard MIT-BIH database. Five types of ECG signals are used for
classification; they are normal sinus rhythm (NSR), left bundle branch block (LBBB),
right bundle branch block (RBBB), premature ventricular contraction (PVC) and
pacemaker (PM). The proposed system combines the neural network adaptive
capabilities and fuzzy inference system with the suitable filter design to give a promising
classification accuracy of 99%.

Artificial neural networks (ANNs) are widely used in different areas of nowadays
applications. Many challenges are imposed on the practical implementation of ANNs.
Some of them are: the number of samples required to train the network; the number of
adders, multipliers, nonlinear transfer functions, storage elements; and the speed of
calculations in either training phase or recall phase. In this paper, the RAM-based
neural network is investigated. No weights, adders, multipliers, transfer functions are
required to implement it neither in hardware nor in software, but at a cost of large
RAM utilization. In addition, a small number of samples are required for training.
However, in hardware implementation, a large size of memory is required to train it.
The network is implemented on the FPGA platform. The Stratix IV GX FPGA
development board, which is provided on large on board RAM, is used. A considerable
speedup of 237 is achieved in either training or recalling phases. A comparable error
rate of 7.6 is achieved when MNIST (Mixed National Institute of Standards and
Technology) database are used to train the network on handwritten digit recognition

The use of wood shavings, as a recycled waste product from the wood furniture
industries is an interesting technique to produce lightweight cement composites. This
study aims at examining the mechanical properties of wood shavings-cement lightweight
composites. First, the wood shavings were pre-treated with water or superplasticizer or
Cement Based Bitumen Emulsion (CBBE). Then, the compressive strength and tensile
strength of the wood-cement matrix were experimentally evaluated. Finally, it is shown
that the addition of wood shavings to cement paste gives a composite with satisfactory
mechanical strengths with respect to its weight and higher toughness in addition to
environmental and economic benefits.

This study was conducted to investigate the properties of lightweight concrete produced
by the inclusions of polystyrene beads and perlite that can be used for production of
Canoe. Different percentages of polystyrene (20, 35, 50 and 65%) were used. Besides, the
50% of polystyrene beds with different percentages of perlite (10, 20, 30, 40, 50 and 60%)
as partial replacement of sand were used. The fresh density, compressive strength,
flexural strength and absorption capacity of the mixes were tested. The results show that
the uses of 50% of polystyrene with 50% of perlite as partial replacement of sand exhibit
suitable ranges of density, compressive and flexural strengths of lightweight concrete
used for canoe production. Thus, the Canoe produced from these inclusions of
polystyrene and perlite show a clear success in terms of floating.