Al-Nahrain Journal for Engineering Sciences

Noise effects on the students include both
auditory and non-auditory effects and cause the
lack of concentration and disability of
learning and communication. The Faculty
of Engineering was chosen to conduct the
questionnaire because the students have
both theoretical and practical courses and
they spend one-third of their day in
the laboratories, so it is expected they exposure to
noise more than other faculties’ students A
questionnaire was conducted to understand the
effect of noise on student behavior and whether
they could classify the sounds that they heard as
noise and determine the noise sources (indoor,
outdoor) and the noisiest places (classroom,
laboratory, and campus). 438 students participated
in this questionnaire from all stages, and
they covered eight engineering departments in the
Faculty of Engineering, Mustansiriyah University.
A statistical analysis of the questionnaire found
that 39.5%, 46%, 32% and 49% of students
suffered from noise in classrooms, laboratories,
open spaces and closed spaces (campus),
respectively. In the actual situation, the effects
that students experience can be arranged in the
following descending order: feeling
discomfort, hearing difficulty, raising the voice
when speaking, lack of concentration,
headache, tinnitus and nausea. Using a sound and
vibration meter with the analyzer, the noise levels
in dBA were measured in the noisiest places that
the students mentioned. The noise levels exceed
the standard limitation that organizations and
agencies such as the WHO determined.

In this research the behavior of cylindrical
shells under axial load have been studied. The
experimental program is included two groups: the
first consists of nine cylinders; each has a
diameter of 150 mm, while the height varies from
100 to 500 mm and thickness of 1.5 mm, test
results show that the optimum height to achieve
the maximum strength is 300 mm with L/D equal
to 2. The second group consists of two cylinders
with diameter of 150 mm and height of 300 and
500 mm strengthened with stiffeners plate
welding from inside at four quarters with
thickness of 1.5 mm and width 20 mm fabricated
from the same metal of the cylinders. After testing
these two cylinders were gain an increase in the
strength reached to 42% for 300 mm cylinder and
26.4% for 500 mm cylinder. The failure modes
for these two groups are: the buckling at bottom
like “elephant’s foot” for cylinders height from
100 to 300 mm and “inelastic buckling” for
cylinders height from 350 to 500 mm for the first
group, and the ” inelastic buckling” for the second
group

Abstract
Due to their very good mechanical properties
of composite materials which led to a huge
increase in its application in a lot of fields.Epoxy/
PS(polysulfide) composite materials behavior in
fatigue was reported. different weight fraction of
PS (2%,4% and6%) were studied .Surface
roughness properties of the blended composites
were found for all weight fraction of PS and their
fatigue properties are studied .Fatigue test was
carried with rotating bending method. The loading
in the test was sinusoidal wave type. The loading
wave ratio is R = -1 and the frequency of loading
is applied to avoid temperature rise with a
frequency equal to 5Hz. Fatigue strength ,fatigue
life and fatigue limit of the tested composites
from standard curves are calculated. The addition
of PS resulted in an enhancement in the fatigue
values and cause the surface roughness to
decrease at a considerable rate, the blend hardness
is reduced considering shore A test

Hydraulic structures can be accepted as the
key components in improving aeration efficiency
because of the strong turbulent mixing associated
with substantial air bubble entrainment at these
structures. Different hydraulic structures have
been designed to enhance aeration such as stepped
cascades. A laboratory model of stepped cascade
weir with five different shapes of end sill
(normal, triangle, rectangle1, rectangle2 and
rectangle3) have been installed at AlMustansiriya University, College of Engineering
to evaluate treatment system and reduced
pollutants in marginal water for different flow
rates (35,60 and 80 L/min). Results indicate that
high removal efficiency of all pollutants
parameter (Cu, Cr, Mo, Br, Fe, Mn, Zn, PO4, Cl-
,
ClO2, Hardness as CaCO3, NH3, NO2, Toxic
matter) is for rectangle1 shape at Q=60L/min.
High aeration efficiency is 45.7% for rectangle1
shape at Q=80L/min. High removal efficiency for
BOD5 and COD are 48% and 47% respectively
for rectangle 1 at Q=80 L/min.

Square patch antennas (SPA) are widely used
today's in wireless communication systems,
mainly with popular frequency of 1.575 GHz.
Wireless devices are the main source of
propagation and radiation for the Electromagnetic
(EM) rays. The waves penetrate tissues of the
human beings and cause health danger. A fractal
Sausage Minkowski square patch antenna is
proposed, designed and simulated. A Fractal
antenna is designed and simulated at 1.575 GHz
for GPS application using CST MW studio 2014.
Specific Absorption Rate (SAR) is the term which
measures the exposure of human to
electromagnetic waves radiation for
communication antenna. SAR values are
calculated over tissues mass with respect to the
IEEE and (ICNIRP) standards for head safety.
The SPA antenna presents the smallest SAR
levels in adult head tissues at 2nd iteration
Sausage Minkowski fractal antenna. The results
show that the SAR levels for the three different
fractal iteration are the highest in (ICNIRP)
standard as compared to (IEEE) standard.

One of the unique properties of laser heating
applications is its powerful ability for precise
pouring of energy on the needed regions in heat
treatment applications. The rapid rise in
temperature at the irradiated region produces a
high temperature gradient, which contributes in
phase metallurgical changes, inside the volume of
the irradiated material. This article presents a
comprehensive numerical work for a model based
on experimentally laser heated AISI 1110 steel
samples. The numerical investigation is based on
the finite element method (FEM) taking in
consideration the temperature dependent material
properties to predict the temperature distribution
within the irradiated material volume. The finite
element analysis (FEA) was carried out using the
APDL scripting language (ANSYS Parametric
Design Language) that is provided by the
commercial code ANSYS. Infrared (IR)
thermography technique was used to explore the
workpiece surface and to validate the obtained
results. The work takes into account the effect of
different speeds of the laser beam and pulses
overlap on the temperature pattern of the material
surface and depth.

The adsorption characteristics of Nickel (II)
onto Iraqi Bentonite clay from aqueous solution
have been investigated with respect to changes in
pH of solution, adsorbent dosage, contact time
and temperature of the solution. The maximum
removal efficiency of Nickel (II) ions is 96% at
pH=6.5 and exposure to 100 g/L adsorbent. For
the adsorption of Nickel (II) ions, the Freundlich
isotherm model fitted the equilibrium data better
than the Langmuir isotherm model. Experimental
data are also evaluated in terms of kinetic
characteristics of adsorption and it was found that
the adsorption process for Ni+2 ions follows well
pseudo-second-order kinetics. Thermodynamic
functions, the change of free energy (ΔG°),
enthalpy (ΔH°) and entropy (ΔS°) of adsorption
are also calculated for Nickel (II) ions. The results
show that the adsorption of the Nickel (II) ions on
Iraqi Bentonite is feasible and exothermic at (20-
50) °C

Friction Stir Welding is one of the most
practical welding process at the solid state.
Friction Stir Processing is used to enhance the
microstructure of FSW welded zone. The present
study investigates the effect of welding
parameters on the tensile properties of FSW and
FSP joining 3 mm AA 5083 - H111 aluminum
alloy by means of stress – strain curve with a
uniaxial tensile test and by comparing the
efficiency between FSW , FSP and base metal
.The experiments were conducted with 1000,1500
and 2000 rpm rotation speeds ,and 20,40 and 60
mm/min travel speed. The best result of the
welding joint was shown at the 20 mm/min feed
speed and 1500 rpm rotational speed for FSW,
and 40 mm/min feed speed and 1500 rpm rotation
speed for FSP. The efficiency of ultimate tensile
strength reaches to 92% for FSW and 94% for
FSP.

Transfer function characteristics of a DC
machine are used in this paper to estimate speed
and torque in four quadrant operation modes.
Estimation speed and torque control based on a
DC machine transfer function is implemented by
measuring the DC chopper instantaneous average
output voltage and current.
MATLAB\SIMULINK is used to implement the
DC drive circuit in the forward and reverse
motoring and regenerative modes, respectively.
The DC drive system is simulated at different
speed and load torque values in steady state and
dynamic operating conditions. Simulation results
demonstrate success of the sensorless and PI
controller systems, which gives satisfactory
agreements between the estimated, actual and
reference speed and torque values.

In this work, model fuel (Thiophene in
hexane) was treated for sulfur removal by
adsorptive desulfurization method using modified
bentonite with sodium (Na-B) adsorbent. Batch
and continuous mode were used in this study.
Several operating parameters such as initial
thiophene concentration of 250 to 2000 mg/L ,
adsorbent dose 0.1 to 0.8g/ml were studied for
sulfur removal %. Also a comparison between
raw and modified bentonite was performed in this
study. In continuous mode, a packed bed of Na-B
adsorbent column was used at constant initial
thiophene concentration and liquid hourly space
velocity (LHSV) to study the breakthrough curve
of thiophene. The results showed that Na-B
adsorbent was better than raw bentonite in
removal of sulfur components. The removal
percentages was 67,75,87,and 91% for 500 mg/L
initial thiophene concentration using adsorbent
dose o.1, 0.2, 0.4 and 0.8g/ml respectively , and
87, 75, 57, and 53% for adsorbent dose of 0.2
g/ml using initial thiophene concentration of 250,
500, 1000, and 2000 mg/L respectively. It was
concluded that when increase the dose of
adsorbent, the removal of sulfur increase , and
when increase the initial concentration the
removal decrease

In this work, nine types of laminated
composite materials used for experimental study
to investigate the tensile and fatigue properties of
partial foot prosthetic socket which fabricated by
using vacuum pressure system . The composite
material matrix were Lamination 80:20and
reinforced with nine types of laminations (perlon,
n-glass, fiber glass and carbon) by variation of
thickness according to lamination. Results show
that the mechanical properties were improved by
increasing the two layers of carbon fiber, fiber
glass and n-glass layers instead of zero layer with
six layers of perlon lead to the increased in(yield
strength σy, ultimate tensile strength σult and
modules of elasticity E with (71% ,76% and
58%) respectively for carbon fiber, (20% , 19%
and 40%) for fiber glass and ( 22% , 5.5% and
29% ) for n-glass. Results show that
(3perlon+2carbon fiber+3perlon) gives the best
value of mechanical properties and has higher
Endurance limit stresses (σe) which increase
lifetime for the patient . It is recommend to use
this type of lamination for the layup partial foot
prosthetic socket because it meets the demand
lamination layers for acceptable mechanical
properties and its minimizing the cost of socket
lamination to suitable costing value.

Particles filled polymer composites started to be
essential because of their wide applications in
addition to reducing the cost of polymer, which is
a main problem. The aim of this work is studying
the insulation of particulate composites resulting
from the addition of filler (glass or porcelain)
waste powder to reinforced epoxy matrix. Samples
with and without filler were exposed to some tests
to decide the influence of the filler contents on the
characteristics of epoxy. Epoxy is synthesized with
filler particles having (90 micron) particle sizes as
reinforcement. Composites of epoxy with varying
percentage (0 to 40 weights %) of filler were
prepared by using hand lay-up method. The
nondestructive tests consist of thermal
conductivity; ultrasonic test and water absorption
test have been investigated. The composite showed
an improvement in physical properties with the
addition of filler according to their percentages.
The result show the addition of the filler in all
proportions to the epoxy increased the density of
the composite, leading to the ultrasonic pulses
velocity ranges between 2100 m/s and 2800 m/s.
Increase glass and porcelain percentage cause
increase in density which increases the acoustic
impedance. While the thermal conductivity
decrease with glass powder percentages in the
composite increase, unlike the increase in
porcelain percentage which causes an increase in
thermal conductivity. The 40% percentage of glass
in the epoxy had higher effect on reduce the
thermal conductivity. As well as from the results
the epoxy reinforced by porcelain powder would
have lower water absorption than epoxy reinforced
by glass powder

In this paper, an Adaptive Sliding Mode
Controller (ASMC) is designed and applied for a
magnetic levitation system (Maglev) where a steel
ball is desired to be stabilized at a desired position
with existence of uncertainty in system model.
Additionally, a sliding mode differentiator (SMD)
is used for estimating the ball velocity since it’s
needed for the controller to work properly. The
designed controller and differentiator are applied
practically to an experimental laboratory size
magnetic levitation system and the results were
plotted to show the behavior of the system under
the effect of the designed controller. The
experimental results reveal clearly the
effectiveness and ability of the suggested
controller in forcing the steel ball to follow
various desired position.

This study implements the soft computing
techniques such as Artificial Neural Network
(ANN) and an adaptive Neuro-Fuzzy (ANFIS)
approach. Thus to model the rutting prediction
with the aid of experimental uniaxial creep test
results for asphalt mixtures. Marshall samples,
having Maximum Nominal Size of 12.5 mm, have
been selected from previous studies. These
samples have been prepared and tested under
different conditions. They were also subjected to
different loading stress (0.034, 0.069, 0.103)
MPa, and tested at various temperature (10, 20,
40, and 55) °C. The modeling analysis revealed
that both approaches are powerful tools for
modeling creep behavior of pavement mixture in
terms of Root Mean Square Error and Correlation
Coefficient. The best results are obtained with the
ANFIS model.

The daily peak load forecasting for the next
day is the basic operation of generation
scheduling. The approach of using ANN
methodology alone is limited which has
generated interest to explore hybrid system. In
this paper a search of genetic programming to a
short term load forecasting is presented. A
genetic architecture with the fitness
normalization has been used to find as optimum
data peak load of Baghdad city. The optimize
data applied to the ANN to be trained and tested
to estimate the daily peak load of Baghdad city.
Different cases for load forecasting are
considered with the aid of MATLAB 7 package
to get the estimation of the next day. So an
improvement method of genetic optimization is
proposed to get a better solution for the load
estimation rather than artificial neural network.

This paper provides a theoretical framework
for analysis of consensus algorithm for multiagent networked systems considering the role of
directed information flow. Improvement of the
performance of the implemented consensus
algorithm has been achieved by using Particle
Swarm Optimization (PSO). Concepts of
information consensus in networks and methods
of convergence are applied as well. Our analysis
framework is based on tools algebraic Graph
Theory (GT). Simulation of multi-agent system
and the performance of a consensus algorithm
have been discussed. Acceleration the network
while approaching the required goal has been
accomplished and elimination of undesired swing
that appears during the acceleration was proved.

Lightweight foamed concrete (LWFC) is
characterized as a light in self-weight, selfcompacting, self-levelling, and thermal and sound
isolation. But it has low strength and low ductility
which leads that the application of (LWFC) in the
building construction is limited. The flowability of
the fresh mix of (LWFC) was evaluated by flow
test. While the hardened properties of (LWFC)
include, compressive6 strength, tensile6 splitting6
strength, flexural6 strength, and 6modulus of
6elasticity. This6 study6 focuses6 on the effect of the
adding of silica fume and steel fibre on the
mechanical properties of (LWFC). Silica fume was
added as (5%) and (10%) by the weight of cement
and steel fiber (0.2%) and (0.4%) of the total
volume of the mix. The density of lightweight
foamed concrete was 1800±50kg/????????3, and cement
to sand ratio was (1:1) with water cement ratio
(0.28). The results indicated that adding of silica
fume6 and steel6 fiber6 have great effect on the
mechanical properties and improve them. The
addition (10%) of silica fume and (0.4%) by
volume of steel fiber was the best ratio that
improves the mechanical properties of the
lightweight foamed concrete (LWFC). The
pozzolanic index of the (5%) and (10%) silica fume
was (21.9%) and (74.76%), respectively