Engineering and Technology Journal

This research aims to study the effect of localized laser surface treatment on
mechanical behavior of low carbon steel. Laser Cw Nd : YAG was used in the
treatment hardening of the specimens for different laser energy (2.7,3.3,4.37100J ),
with time interval for the beam (10-2 sec) and the laser intensity(4500,5500,7100
Watt/mm2) . Different mechanical tests were achieved Static and Dynamic on the
specimens which were surface treated .Static tests included ( Tensile test,
Microhardness test) ,While the dynamic test included (Impact test ).
The results show that the mechanical properties for low carbon steel H[.hx
strength by(0.9,10,25.5%) , ultimate tensile strength by(6.4,16.24,24.59%),while the
increment fracture stress by (12,17.28,34.87%),also increment in microhardness by
(3.4, 5 , 23% )and toughness by (4.3,10.86,20.8 %). Some of mechanical properties
for low carbon steel reduce with increasing in laser energy which show in Young
modulus (26.06,40.89,50.8%), Rigidity modulus by (25,40.5,48.99 %) , Poisson s,
ratio (1.29,2.34,3.69%)

This study deals, with the problem of the widening expanse of time to download
is not limited to a certain mechanical property of clear-cut, but intertwined and
branched out and became one of its aspects scientific insomnia ... Because the total
value of creep does not give us a firm base to judge the causes, but under certain
circumstances can be separated total distortions for sample into two recoverable
deformation and irrecoverable deformation. Therefore, the sum that in order to
facilitate the perception of mechanical we need to know the creep resilience
modulus and may even add images to unforeseen come to know through the flexural
strain energy , which helps to understand this mechanism in order to avoid the
dangers arising from the phenomenon of creep.
Generally has this study measured the ability of novolak material side by side with
the composites prepared reinforcing the novolak material, by glass fiber once and
asbestos fibers once and hybrid fibers (30% fiber glass +30% fiber asbestos) again on
the absorption of elastic energy which disappear after the removal three – point
flexural stress and is know by creep resilience modulus, note that the ratio weighted
mount reinforced (60%) and that the samples of various kinds attended with two
different ratio from the material hardened (Hexamethylene - teraamine) (HMTA), a
percentage (10%) weight once and (14%) and weight again .
* The practical results showed that a small fraction absorbed elastic mechanical
energy after the first period of time from loading to be non-refundable after the
demise of the forces of bending acting on them, and this shows the extent of
accumulation of elastic strain energy stored in novolak material over time and raise
the value of creep resilience modulus and the consequent decrease of the potential to
restore the original situation after removing the stress and thus discouraged the return
of this energy absorbed .
As a reference this study also to the high elastic strain energy and creep resilience
modulus For an article novolak when compared composites as a result of the lack of
fiber foregoing in. This is a clear proof on the efficiency of reinforcement mechanism
to be strengthened to raise the efficiency of novolak to return the energy bending
absorbed, and study also showed that the increase the proportion of material hardened
(HMTA) to (14%) lead to the devaluation of resilience modulus which confirms the
sharply decreasing the accumulation of elastic strain energy to novolak material and

(n-p) PbS-Si HJ detector has been fabricated by pyrolytic spraying of PbS
heterolayer onto p-type silicon wafer. PbS-side of illumination in the wavelength
range (450-1150 nm) revealed that the quantum efficiency plateau fairly conforms
to that of Si homojunction. Significant specific detectivity of about 8.5 x 1011 cm
Hz1/2 W-1 has been obtained at 850 nm wavelength. Signal to noise ratio revealed
an optimum operation voltage at 2.5 V.

This research is aimed to develop the electrical conductivity of PEM fuel cell
through the using of a series of graphite plates. The effect of width, thickness of plates
in addition to the current and gas flow rate (hydrogen and oxygen) were studied.
Results showed that electrical conductivity can be reached to the optimum value
(850S\cm), when cell thickness, current and gas flow rate are 0.3cm, 8.13A and 0.6
L\min respectively.

The future of computer-aided design (CAD) and computer-aided manufacturing
(CAM) depends on the ability of their two processes to communicate with each
other and with intermediate manufacturing database. Therefore, the development of
a successful approach to the integration of CAD and CAM will require solution to
several fundamental problems in planning and geometric reasoning. The first
problem is the interface between CAD and CAM, that automatic feature
recognition is an indispensable technique to solve this problem. We address this
problem by developing an algorithm, which is considered an effective approach to
extraction and of hybrid manufacturing features of symmetrical parts. The
developed algorithm is based on the syntactic pattern primitive concept supported
by production rule technique. This approach is considered a powerful tool applied
to feature recognition field for symmetrical parts

The main aim of the present study is to design and test the dehumidify system
for air-conditioning unit and testing rig to find out the performance of using
polymer technique to control the inside conditions, that are represented by relative
humidity and temperature in testing room by using desiccant wheel (Cromer cycle),
and testing the effect of some parameters which can improve the performance of
this system. An air-conditioner unit of 2tons capacity was installed in this system
and used one type of desiccant material (silica gel) was used in this work. Two
thicknesses of desiccant material and two widths (channels depth) were studied
3.5mm with channel depth 5cm and 2.5 mm with channel depth 20 cm and wheels
diameter of 90cm.Four rotational speeds for desiccant wheel were studied (36, 45,
60, and 90) rph and the regeneration temperature was used to control the inlet
regeneration air temperature using a number of electrical heaters. The series of test
showed that, the best COP, efficiency and relative humidity control within the
conditioned space was for the silica gel at thickness 2.5mm and channel depth
20cm. The maximum adsorption and desorption rate was 0.5427g/kg and
1.322g/kg respectively at 36 rph and (36.5 oC) regeneration temperature and the
best COP of A/C was about (5.12) at 36 rph and (42 oC) regeneration temperature.
Experimentally the best sensible and total efficiency that can be achieved was
(18.1%) and (17.98%) at 45 rph and (30.6 oC) regeneration temperature and
(17.88%), (17.76%) at 36rph and (30.91oC) regeneration temperature. The best
latent efficiency was (6.2 %) at 45 rph and (43.26 oC) regeneration temperature

In this paper, a proposal for designing and implementation of general BIOS
program have been done. This program consider as a modified version derived
from previous versions with configure and adding a new activities differs from the
others BIOS programs such as learning students, help and adjusting components
using mouse only (never using the keyboard) in all windows of the implemented
program. Also, the program has a flexibility to add any necessary function or
activity.

Advanced Encryption Standard (AES) is a symmetric-key encryption each of
these ciphers has a 128-bit block size, with key sizes of 128, 192 and 256 bits. The
AES cipher is specified as a number of repetitions of transformation rounds that
convert the input plaintext into the final output of ciphertext. Each round consists
of several processing steps, including one that depends on the encryption key[1,2].
This research proposes a technique intended to make the Advanced Encryption
Standard (AES) more safe and secure. Through the generation of random key, and
permutation key sites in each round, instead of the process of expanding key
locations in addition to the proposed permutation the plaintext before entering the
encryption and inverse permutation for resulting ciphertext.

In this work a composite materials were prepared containing matrix of polymer
blend (polypropylene 80% + polycarbonate 20%) reinforced by (carbon black) with
different of weight fraction %. The specimen sheet, were obtained by hotcompression
from extruded material, using single extruder operated at a
temperature between (190-200)Co. The extrusion processes give homogeneous
mixer through a regular selection of machine screw revolution per minute and
temperature used in extrusion process. The weight fraction of the carbon blacks
ranged from 0.0 up to 20 wt % with the polypropylene and polycarbonate blend.
All samples related to, mechanical, thermal and electrical tests were prepared by
single –extruder.
By discharging a high voltage through the composite it was found that the
resistivity of the composite decreased from (1.00E+09)-(1.00E+028). Carbon
black–polypropylene and polycarbonate composites show significant differences
from the neat blends measured in the frequency range. The study of physical test
show that the thermal conductivity decreases with the increase of weight fraction
from (0.157-0.23).

A study of temperature effect with a significant impact on rheology fluid, mixing time,
and also volume fractions was carried out. In this study, the w/o emulsions were prepared
into three volume ratios (30-70%, 40-60% and 50-50% w/o) and at mixing time (5, 15 and
30 minutes) by using one type of crude oil (Kirkuk). The w/o emulsions were stabilized, then
characteristics were measured. The effective viscosity of water-in-oil emulsions depends
mainly on the volume fraction, mixing time and temperature, along with several minor
effects, such as shear rate, shear stress stream and viscosity of oil.

The spectral properties (absorption and fluorescence) of laser dyes (R6G& R B)
mixture have been studied; this type of laser dye belongs to the Xanthenes family,
and has been dissolved in chloroform to prepare (1*10-5, 2*10-5, 5*10-5, 7*10-5, 1*10-4
M) at room temperature.
The achieved results pointed out to an increase in the absorption and fluorescence
intensities with the increased concentration which are found in agreement with Beer –
Lambert law. These results have been also showed an expansion in the spectral range
of absorption and fluorescence with a noticed shift in the direction of longer
wavelength.
The quantum efficiency of the dissolved Rhodamine mixture in chloroform has
been calculated by using the same above concentration (96%, 91%, 80%, 71%, and
66%) respectively. The radiative life time ( 0.21 , 0.41,0.89,1.19 and 1.48 ) ns and
fluorescent life time (0.20 , 0.37,0.71,0.84, and 0.97 ) ns respectively .
It has been determined that the resulting overlap between the absorption spectrum and
fluorescence spectrum for(R 6G&RB) mixture is more than that shown for the every
dye alone solution, therefore stock shift will be more

Infertility is one of the major public health problems in the Arab world, as it
affects about 15% of couples seeking children. in 50% of these cases, the male
partner is responsible for infertility . Y microdeletions in the azoospermia
factor (AZF) region are known to be associated with spermatogenetic failure.
In the current study, the aim was to determine the molecular background of
male infertility using tag sequence tagged site (STS) associated with
Azoospermia cases . We evaluated the incidence of Y chromosome
microdeletions in (100) Iraqi infertile male patients with primary idiopathic
male infertility and 50 fertile males (controls) by polymerase chain reaction
using 11 STSs in the azoospermia factor (AZF) region.
Of the 100 infertile men, Y-chromosome Microdeletion in the AZFa ,
AZFb and AZFc regions were detected in (64%)cases. The pathological
significance of these deletions is not clear yet or most probably belongs to
environmental pollution by depleted uranium used by collision forces in
Al-Anbar governorate

One of the major drawbacks of OFDM is high Peak-to-Average Power Ratio
(PAPR) which can result in poor power efficiency and serious distortion in the
transmitter amplifier. In this paper, the advantages of two different approaches to
PAPR reduction are exploited in order to reduce the PAPR more significantly. The
first approach is based on clipping and filtering which provides a high PAPR
reduction at the cost of signal distortion. The second approach (Partial Transmit
Sequence PTS or Selected Mapping SLM methods) results in no distortion. The
performance of the three proposed combined methods(Clipping And Filtering with
PTS scheme, SLM with Clipping And Filtering scheme, and PTS with Clipping And
Filtering scheme)are evaluated on the PAPR distribution function and on the Bit
Error Rate as a function of Signal to Noise Ratio in Additive White Gaussian Noise
Channel. The simulation results show that the proposed PTS with Clipping And
Filtering scheme provides more PAPR reduction without degradation in the BER
performance as compared to the other two proposed scheme (Clipping And Filtering
with PTS scheme and SLM with Clipping And Filtering scheme). The simulation
results of PAPR reduction and BER performances are simulated using MATLAB
R2009a computer simulation software.

In this paper n-CdSe/p-Si heteroj unction photodetector was fabricated by
thermal-evaporation technique of CdSe thin film grown onto single crystalline Si
substrate . The energy gap of CdSe film was estimated from transmittance spectra
and found to be (1.89 eV) . The temperature dependence of Seebeck coefficient
was studied . The conductivity of CdSe thin film is n-type and the value of
activation energy is (0.59 eV). Heterojunction properties included dark and
illuminated current-voltage (I-V) and capacitance-voltage (C-V) characteristics.
From I-V plot, junction ideality factor for heterojunction was calculated to be
1.43, and providing information about the current transport mechanism. The linear
variation of the experimental curve C-2 vs. V is indicative of the presence of
abrupt heterojunction and it used to determine the experimental value of built-injunction
potential Vbi . From illuminated I-V plot at different intensity levels
(90,180,240) mW/cm2 , the linearity behavior of CdSe/Si heterojunction was
investigated

The problem of founding important information in complex medical images which are
needed in diagnosing of diseases with the complex data considered as one of the
predication problem these days, so it is necessary to find aided means for diagnosing
process. Artificial neural network (ANN) is one of them. This paper deals with the
designing and implementation a classification ANN module for Lever Hepatitis(class-C)
or type-C which doesn’t have any vaccine these days. The different in diagnosing
between hepatitis and other liver diseases is often difficult on purely clinical grounds in
addition the damage to the liver causes changes in the pattern of the serum enzymes and
in recent years this has led to develop disease testing and its vaccine. Elman neural
networks (NN) have been applied for automated detection of various medical diseases.
Like its application on blood sample tests extracted from on line microscope (like it used
in this research).That feature selection is an important issue by removing features that do
not encode important data information from the images used.This helps physicians to
extract features which aided them in diagnosing process. Kernal principle component
analysis (PCA) is used to represent blood images as eigen-features of training images in
addition to extract mathematical module for classification of it. Finally a neural network
(NN) is trained to perform the typical images and classify them (diagnosing process). The
produced NN system produces used a matlab package in order to design and diagnose the
proposed module. The object of this system used in our work is to diagnosing lever
Hepatitis type-C in samples of blood images wherever difficulties in practical
experiments by finding an optimal feature from specialists whom work in laboratories