Al-Nahrain Journal for Engineering Sciences

The research includes study the visual al pollution as a phenomenon spread in the large cities greatly, due to
many factors as the fast technology development and misuse the structural planning in addition to wrong
behaviors of environment's users, the matter which affect greatly in receiving the image at the recipient.
Then the visual pollution result from many factors such as signification marks especially trade marks of all
its types, colors, shapes and volumes as well misdistribution the street furniture and garbage containers and
random the buildings frontages in respect of finishing materials, disarrangement gaps and bulges between
blocks, and cheating the design and alteration it as to the residential buildings in form leads to non agreement
with design, regarding to the importance of residential buildings in our life, will concentrate the research on
studying the visual pollution which result from alteration of the residents to the image of residential
buildings randomly.
From review researches to be clear of existence a problem with regard to studying the visual pollution, and
then finished it studying out of the role of signification marks especially trade marks and some of the street's
furniture role; but it does not finish the study of visual pollution which result from change the residential
buildings images, based on that, the aim of research it will be ( The effect of visual pollution resulting from
the random change of the residential buildings images in receiving the image at recipient ).
The problem of research will be (non obviousness the role of visual pollution which result from change of the
residential buildings frontages in receiving the image at recipient).
To solve the research's problem this matter will require the following: -

The study was to investigate the behavior of
excavation in cohesive soils using the bounding
surface model. The model and the finite element
formulation are described and verified. Then the
ground movements were predicted around an
excavation in several types of cohesive soils. The
results of the analysis demonstrate the effects of the
consolidation process and permeability on the
stability of the excavation and that the
displacements at excavation boundaries increase
with increasing permeability and time but at a lower
rate as the permeability value decreased. Also the
study shows a significant influence of the critical
state parameters on the behavior of excavation in
normally consolidated clay comparing with the
surface configuration and hardening parameters of
the model. Thus the modified Cam-clay model
which employs a lower number of parameters can
be used for the problems of excavation in normally
consolidated clay.

Polymers are considered one of the admixture
kinds which they are used to improve the quality
and the performance of mortar and concrete. In
this study the Styrene Butadiene Rubber (SBR)
was used as a polymer to see its effects on the
mortar. The (SBR) is considered as a water
resistance polymer and bonding agent.
Four cement mortar mixes were made in this
study, the first one was considered as a reference
mix which is not include (SBR) while the other
mixes were included (SBR) in deferent
percentages. The (SBR) was added as a
percentage of cement weight. The amount of
mixing water was varied to achieve the same flow
which was accomplished in the reference mix
throughout carrying out flow table test. Flow
table test was adopted according to ASTM
C 1439-99 (1) recommendations.
For each mix, two prisms were prepared to carry
out the drying shrinkage test, nine cubes for the
compressive strength test and three cubes for the
total water absorption test.
It was found that when the quantity of (SBR)
increases, the physical properties of mortar under
study (drying shrinkage, compressive strength
and total water absorption) deteriorate which is
adverse to the proposal of advantages due to
adding (SBR). This result leads to that the
recommendation of ASTM C 1439-99 (1) that
adopt the flow table as criteria of adjusting the
amount of adding water accompanying with
deferent percentages of (SBR) is not adequate.

The damaging effect of military armoured vehicles
with rubber tires on flexible pavements was
studied. Two types of military armoured vehicles
with rubber tires were considered, namely CM32
four-axle and CM32 triple-axle. A measure of the
damaging effect of military armoured vehicles
with rubber tires loads was achieved by correlating
their equivalent loads with the AASHTO
equivalency factors. The equivalent load was
developed on the basis of mechanistic - empirical
approach. It was found that the damaging effect of
the studied loads of CM32 four-axle military
armoured vehicle with rubber tires is 0.262-2.853
times the damaging effect of the standard 18 kips
(80 kN) axle load depending on the thickness of
asphalt layer. It was found that the damaging effect
of the studied loads of CM32 triple-axle military
armoured vehicle with rubber tires is 0.933-4.880
times the damaging effect of the standard 18 kips
(80 kN) axle load depending on the thickness of
asphalt layer. It was found that the damaging effect
of the braking forces of CM32 four-axle military
armoured vehicle with rubber tires is 40 times the
damaging effect of the CM32 four-axle military
armoured vehicle weight only. It was found that
the damaging effect of the braking forces of CM32
triple-axle military armoured vehicle with rubber
tires is 5 times the damaging effect of the CM32
triple-axle military armoured vehicle weight only.

Speech recognition system has been widely used
by many researchers using different methods to
fulfill a fast and accurate system. Speech signal
recognition is a typical classification problem,
which generally includes two main parts: feature
extraction and classification. In this work, three
feature extraction methods, namely SLT, DWT
Db1 and DWT Db4, were compared. The dynamic
time warping (DTW) algorithm is used for
recognition. Twenty three Arabic words were
recorded fifteen different times in a studio by one
speaker to form a database. The proposed system
was evaluated using this database. The result
shows recognition accuracy of 93.04%, 92.17%
and 94.78% using DWT Db1, DWT Db4 and SLT
respectively.

This paper presents and compares the
performance of two Kalman filter schemes, the
discrete extended Kalman filter (EKF) and
unscented Kalman filter (UKF) for estimating the
states (winding currents, rotor speed and rotor
angular position) of two-phase Permanent
Magnet Synchronous Motor (PMSM).
Estimating the states of the system is performed
by propagating the mean and covariance of the
state distribution. For linear systems, the general
recursive Kalman filter algorithm based on
MMSE (minimum mean squared error) is the
straightforward estimation technique to be
implemented. For nonlinear systems, extended
Kalman filter (EKF) is considered to be the best
nonlinear estimator. The EKF is based on
linearizing the state and output equations at
every sampling instant. Therefore, this estimator
requires continuously computation of the
Jacobian matrix. The unscented Kalman filter
(UKF) is based on implementation of the
unscented transformation (UT) to the nonlinear
state distribution (motor model). The UT uses the
intuition that it is easier to approximate a
probability distribution than it is to approximate
an arbitrary nonlinear function or transformation.
Apply this intuition to motor model, a set or
cloud of points are generated around each state
of motor model with specified sample mean and
sample covariance. The nonlinear function
(PMSM model) is applied to each of these points
in turn to yield a transformed sample, and the
predicted mean and covariance are calculated
from the transformed sample. Based on predicted
mean and covariance the UKF recursive
algorithm can be developed. The performance
comparisons are based on standard deviation
estimation errors of both

Surfaces quality is one of the most specified
customer requirements for machine parts. The
major indication of surfaces quality on machined
parts is surface roughness. The research aim is to
study the cutting conditions and their effects on
the surface roughness. This paper utilizes
regression models to predict surface roughness
over the machining time for variety of cutting
conditions in turning. In the experimental part for
turning, different types of materials (Aluminum
alloy, Copper alloy, and Gray cast iron) were
considered with different cutting speed ( ) and
feed rate ( ).
A mathematical Model depending on
statistical-mathematical method between surface
roughness (Rz ) and cutting condition ( , ) were
derived, for the three materials.
The matrix of test conditions included
cutting speeds of the 16, 30, 45 and 60 m/min,
feed rates of 0.17, 0.35 and 0.7 mm/rev while the
depth of cut has been kept constant. The effect of
cutting parameters on surface roughness is
evaluated and the optimum cutting condition for
minimizing the surface roughness is determined.
Mathematical model has been established
between the cutting conditions and surface
roughness using regression. The predicted values
and measured values are fairly close, which
indicates that the developed model can be
effectively used to predict the surface roughness
in the turning machining. As the results of this
work, the mathematical models were used in
predicting surface roughness, can be used in
CAD-CAM manufacturing systems, this
mathematical model helps engineer to reduce the
efforts.

The performance of coherent optical
communication systems is degraded significantly
by the phase noise of the semiconductor lasers.
The phase noise is induced by spontaneous
emission in the laser cavity and yields
broadening in the laser linewidth. This paper
addresses the application of the Low-Density
Parity-Check (LDPC) codes as Forward Error
Correcting (FEC) codes to relax the laser
linewidth requirement. These codes are applied to
three types of heterodyne optical receivers
(BPSK, DPSK and QPSK) operating with finite
laser linewidths.

Strained-layer quantum wells are interesting
for applications in semiconductor lasers , because
they allow both, a wider range of material
combinations, and a certain amount of band
structure and gain engineering. This layer is
effected on frequency shift of the gain spectrum
,but gain increase also possible. The major
advantages of strained quantum wells in the
modulated quantum well lasers diodes are a very
high modulation speed, a low frequency chirp ( -
parameter) , a narrow line-width, and a low
threshold carriers concentration. Strained quantum
well lasers are better than the semiconductor lasers ,
which have a modulation band-width in upper teens
and low twenties of gigahertz.

One of independent laser-based technique is
presented to measure liquid refractive index, which
is important in medical and other applications.
Semiconductor laser diode of 630nm wavelength
serves as alight source for measurement. Results are
presented for different types of liquids in two
methods, one of these methods is done by matlab
language as the theoretical result, the other method
is the opti-cad program which represented the
simulation results.
Good matching found between the two the
theoretical and simulation results. The experimental
setup is high precision, non-contact between the
tools and the liquid which is under test.

In this work, the effects of coherent
radiation (Laser) with different wavelength and
photon energy during the electrochemical etching
process on the structural characteristics PS samples
were investigated. The porosity values were
measured by depending on the microstructure
analyses and gravimetric measurements. Surface
morphology, layer thickness, pore diameter, pore
shape, wall thickness and etching rate were studied
by depending on Scanning electron-microscopic
(SEM) images.

In this research, an analytical study of water using
laser source transport through some samples of
water tubes was presented. He Ne laser with
measured maximum output power 2.83 mW was
used to determine the purity of water by measuring
its output power when it was passing through tube
of water. This tube was initially filled by water and
then by distill water contain different ratio of salts
and clay. For each case, the output power would be
measured and calculated its attenuation which was
occurred when laser was passing through the water.
The attenuation happened in the laser beam when
transport through the water sample that contain
NaCl due to the absorption process. The attenuation
happened in the laser beam when transport through
the water sample that contain clay due to the
scattering process. Water tap mostly contain
different ratio of salts and clay so the attenuation
accurse in laser beam is due to absorption and
scattering process, and it can be compared these
results with that produce when mixing NaCl
solution sample with the clay sample.