Print ISSN: 1681-6900

Online ISSN: 2412-0758

Issue 4,

Issue 4


Experimental Study of Simultaneous Heat and Mass Transfer in Falling Film and Bubble Mode (LiCl) Absorbers

Kamal M. Ahmad; Orooba .N. Abdullah; Mohammad F. Abid

Engineering and Technology Journal, 2012, Volume 30, Issue 4, Pages 529-545

The study involves lithium-Chloride absorption process for the falling film and
bubble columns absorbers, working at the same operating conditions. The results
obtained were used to analyze the transfer process during the absorption of water
vapor in the aqueous solution of LiCl.
The performance of both absorbers was investigated for various solution flow rates
(0.1-0.5)kg/min , various gas flow rates (1-9) lit/min and inlet solution concentration
(40-50) wt% . Results showed that bubble absorber is superior to the falling film
mode for mass and heat transfer and that the efficiency of bubble columns is more
than that of falling film absorbers. Increasing the solution flow rates rarely affected
the mass transfer, but improved the heat transfer. To evaluate the performance of
mass and heat transfer, experimental results obtained were plotted as Nusselt and
Sherwood number versus operating conditions respectively for falling film and
bubble modes. A power law correlations were obtained for the objective functions
(i.e., mass and heat transfer coefficients ) with correlation coefficient between (0.91
and 0.97) .

Preparation CuO and CuCO3Cu (OH) 2 Crystal Nano Particles by Using Microemulsion Method

Sabiha Jabbar Beden; Hassan Ismail Dumbous; Kassim Mohammed Sahan

Engineering and Technology Journal, 2012, Volume 30, Issue 4, Pages 546-555

A microemulsion method for preparing colloidal copper nanoparticles in
microemulsion is reported. The obtained copper carbonate CuCO3⋅Cu(OH)2 nanoparticle
and copper oxide CuO nanoparticle were characterized by powder X-ray diffraction
(XRD), atomic force microscopy(AFM),transmission electron microscopy (TEM) and Xray
fluorescent(XRF) analysis, the purity of material and average particle size about 10
nanometer.. A microemulsion is thermodynamically stable ,optically isotropic derision
of two immiscible liquids consisting of nano-size (CuSO4.5H2O) domains of one or
both liquids in the other (white oil),stabilized by an interfacial film of the surface-active
molecules. The materials mixed to have new immiscible solution , add chemical materials
to reduce surface tension and to reduced interfacial atomic bonds to very low level , the
very fine dispersed spherical micelles in microemulsion are thermodynamically stable
due to a combination of very low interfacial tension very small nanoparticles diameter of
(2-5) nm. Addition another of chemical material as react agent or reduced agent and
precipitate agent to product final material CuCO3⋅Cu(OH)2.Synthesis of monodispersed
CuCO3⋅Cu(OH)2 nanoparticles with refractive index similar to glass plates by using
ultrasonic spray pyrolysis technique by method .Yielding homogeneous ,low defect thin
films of high transparency ,that can be used as color filters for liquid crystal displays .

The Influence of Friction Stir Welding and Process Parameters on the Static and Dynamic Mechanical Properties of 2024-T3 Aluminum Alloy Weldments

Nameer A.Hamoody; Moneer H.Tolephih; Shaker S. Hassan

Engineering and Technology Journal, 2012, Volume 30, Issue 4, Pages 556-567

The present work is aimed to study the friction stir welding and process for the
aluminum alloy 2024-T3, a threaded pin with a diameter of 6 mm and a concaved
shoulder of 18 mm welding tool was used. The single pass friction stir welding
(FSW) process was performed with clockwise tool rotation at different speeds and
variable feeding speeds. The specimens were tested to determine the best ultimate
tensile strength ( ult) and compared with the as received metal. In addition to friction
stir welding (FSW), another phase of welding named friction stir process (FSP) was
used. The best condition out of the FSW variables was selected in order to examine
the double pass welding processes. It was found that the best result is in forward
welding travel and counterclockwise tool rotation. The maximum tensile strength
achieved at friction stir welding process was 72% of the base metal and didn’t
improve in the FSP process. On the other hand, the fatigue endurance limit was
improved for FS weld ment when followed by FSP, where the reduction in fatigue
endurance limit for FSW specimen was 36% while for FSP specimen was 15% of the
base metal.

Improvement of Sabkha Soil by Using Geomesh and Addition of Polycoa

Hassan Obaid Abbas

Engineering and Technology Journal, 2012, Volume 30, Issue 4, Pages 568-576

Sabkha soil is a rich soil with salt deposited which result from evaporation of
water, it is one of the many types of collapsible soils and in turn is one of the many
types of problematic soils. This soil totally has good engineering properties when dry
,i.e ,moderately bearing capacity with low settlement. But once is wetted it loses its
entire structure (collapse) and undergoes very large instantaneous settlement. A
laboratory model test consists of a cylindrical steel container of 270mm diameter and
300mm height, the soil is brought from Al-Khalis discrete. The density of soil is
controlled by placing the required weight inside the container of known volume, to
the required height. A square footing 40mmx40mm makes from steel is used. The
stress is applied from a fixed loading system designed especially for model tests.
In this study two types of improvement are used , the first improvement consists
of fine geomesh under footing at different depth (0.5B,B,2B),the second
improvement is the addition of polycoat with different concentration to surface of soil
.The first method do not give good results of improvement but the second method
gives good improvement which reduces the collapsibility to 62% at stress level of
50kPa.

Impact of decreasing polynomial degree in time needed to factor a 100 digits integer by General Number field sieve algorithm

Jamal A. Othman

Engineering and Technology Journal, 2012, Volume 30, Issue 4, Pages 577-590

Factoring is very important in the field of cryptography, specifically in the Rivest,
Shamir, Adleman(RSA) public-key cryptosystem, one of the most prevalent
methods for transmitting and receiving secret data which its security relies on the
fact that factoring large composite numbers (may be 300 digits) is computationally
intensive task . The General Number Field Sieve (GNFS) algorithm is the fastest
known method for factoring large integers (100 digits and more), selecting a
polynomial is the first and the most important step of the general number field sieve.
Choosing a "good" polynomial as a first step in GNFS algorithm widely affect the
time needed to factor the integer which we intend to factor .In this paper we concern
about polynomial selection step in GNFS, we try to examine practically the affect of
choosing two different degrees polynomial on the time needed to factor a 100 digits
integer. Base – method is a reasonable first step for generating a suitable
polynomial for the GNFS, in this method we first choose the degree of the
polynomial ( =4 or 5 in our case) and looking for ≈
and a polynomial of
degree for which ( ) = 0 ,we begin with ( ) = Σ
where
the are the coefficients of the base- representation, Brian Murphy in his PhD
thesis considered being the first how deeply study the effect of choosing a good
polynomial on the time needed to factor a number , he came out with a parameter
( ) to measure without sieving the quality of the polynomial ,many programs
have been written using Murphy parameter ( ( )) and iterate on the leading
coefficient of the base- polynomial till reaching the required ( ( )) value which
we intend to reach, we get use from a program freely available on the net which
help us to choose a good polynomial after feeding the program with the required
parameter . We find a 4th degree polynomial need less time than a 5th degree
polynomial to factor an integer of a 100 digits, we present the result of factoring
showing the two factors and the coefficients of the two polynomials and other
information related to the factoring jobs using a python script written by Brian
Gladman's available for free use on the net called (factmsieve.py) in two appendices

Expermential Study of the Performance of Fluorescence Collector

Hussein A. Hadi; Saad T. Hamidi; Ali A. Abdulminaem

Engineering and Technology Journal, 2012, Volume 30, Issue 4, Pages 591-604

The luminescent concentrator which used consisting of organic fluorescence dyes
such as Rhodamine 6G doped in article Polyvinyl alcohol (PVA) to configure a
specific membrane thickness, and then put these films on the glass plate solar collector
model with energy halogen Lamp (1000 Watt) as a source of light to represent of
fluorescence collector.
Examining the effect of these pigments on the efficiency of the solar collector as a
function of the temperature difference between the water inside and outside of the solar
collector. Where the increasing in the amount of the difference between the
temperature refers to increasing the efficiency of the performance of solar collector.
Results showed that the efficient performance of the solar collector increases with the
increase in the intensity of incident light with existence the luminescent concentrator
,where the rising water temperature of (24 K) compared with (20 K) when there is not
existence the luminescent concentrator when the intensity of radiation falling (1500
W/m2) and increasing efficiency of solar collector to 20% .

Hiding Encrypted Color Image within MPEG-2 Video

Firas A. Abdul Latef; Alaa A. Abdul Latef

Engineering and Technology Journal, 2012, Volume 30, Issue 4, Pages 605-614

In any communication, security is the most important issue in today’s world.
Lots of data security and data hiding algorithms have been developed in the last
decade. Hiding data in digital videos makes possible to hide a great quantity of
information when compared to techniques used in images. This work presents
the encryption process of an image with combination of bit and pixel
permutation technique depending on random key, and then steganography
technique that hiding each bit of encrypted image in selected block 8*8
pixels(selected block process depending on high blue color ratio), of the frame
and can extracted that bit after compressed with mpeg-2. Experimental results
show the success of hidden extracted data from the sequence of frames, and also
indicate the effectiveness of the implementation steganography compressed
video with high security features

Color Texture Classification Using Adaptive Discrete Multiwavelets Transform

Matheel Emad El-Deen Abdulmunim

Engineering and Technology Journal, 2012, Volume 30, Issue 4, Pages 615-627

The classification of textures images has attracted the attention of many
researchers. The multiscale techniques for gray level texture analysis have been
intensively studied. In this paper, we aim on extending texture classification of color
images by using the multiwavelets transform, a new notion addition to wavelet. The
recognition of textures deals with both feature extraction and classification phases. In
the classification phase the evolutionary computation techniques (genetic
programming) was used for more speed recognition result evaluation. In our
experiment results the proposed method has achieved 99.6% test accuracy on an
average. In addition, the experimental results also show that classification rules
generated by this approach are robust to some noises on textures

Etching Rate Enhancement of Porous Silicon Produced by Lasers

Mohammed A. Ibrahem

Engineering and Technology Journal, 2012, Volume 30, Issue 4, Pages 628-633

Two laser systems work with different operational modes have been used to
produce silicon nanostructure surfaces. Pulsed Nd:YAG laser has been employed to
produce silicon textured surface which containing nano/microstructures. Effects of
laser energies (80 – 200) mj were examined to produce surface of different structures.
While Diode laser (532 nm) of fixed power (50 mW) was used in the second stage to
modify the porous structure over the textured surface. The effect of different surface
morphology on the laser induced etching process was studied using atomic force
microscope (AFM) and an image processing program to sketch the surface plot to the
samples depending on the optical microscope photos. The photoluminescence spectra
have been utilized to study the nanocrystallite size distribution in porous silicon, it
shows high peak position lies in (2 - 2.1) eV.

Numerical Solution of Linear Delay Fredholm Integral Equations by using Homotopy Perturbation Method

Shymaa Hussain Salih; a Hadi Hassan; Isra; Fuad A. Al Heety

Engineering and Technology Journal, 2012, Volume 30, Issue 4, Pages 634-643

The main purpose of this work is to propose the Homotopy perturbation method
for solving first type Linear Delay Fredholm Integral Equations (LDFIE).A
Comparison between the numerical solution and exact solution has been made
depending on least squares errors. Results are presented in tables and figures.
efficient and accuracy are appeared in applying of this the proposed method.

A Novel Initial Rotor-Position Estimation Method for Switched Reluctance Motors Based on Frequency Measurement

Hosham Salim; Abduljabbar Owaid Hanfesh

Engineering and Technology Journal, 2012, Volume 30, Issue 4, Pages 644-658

This paper presents a novel method which is designed to detect the rotor position
at standstill and also low speeds in switched reluctance motor (SRM). In this paper
the inductance of phase winding is added as a part in Colpitts oscillator and will cause
a change in oscillation frequency according to the rotor position. The phase
inductance regularly varies with the rotor position. Experiments were carried out on
three phases SRM 6/4, where the measured frequency of colpitts oscillator was
converted into a voltage value by the frequency to voltage converter and were then
converted into a digital value to be matched with the proposed digital processing. The
Experimental results showed high accuracy in determining the values of phase
inductance, which produced an estimated rotor position accurately and quickly.

Determinants of E-Learning Implementation Success In The Iraqi MoHE

Jalal B. Raouf; Inam Seger Naser; Bushraa Khireibut Jassim

Engineering and Technology Journal, 2012, Volume 30, Issue 4, Pages 659-671

The aim of this paper is to investigate the determinants of implementation success of
the E-Learning in the Iraqi Ministry of Higher Education (IMoHE) and put a work plan to
make the E-Learning widely implemented in the IMoHE. The Technology-Organization-
Environment (TOE) framework and the E-Learning literature were used to analyze the
factors which may influence this implementation and adoption. A questionnaire which
consists of twenty nine questions divided into three parts: Technological factors
(Information Systems (IS) infrastructure and IS expertise), Organizational factors
(organizational compatibility and organizational benefits), and Environmental factors
(competitive pressure and educational partner readiness) were written. The
implementation success is characterized by two dimensions Internal Integration and
External Diffusion. This questionnaire data gathered from 120 faculty members in the
IMoHE were employed to test the relationships between the research models constructs
using a structural equation modeling (SEM) approach. The results reveal that IS
expertise, and Expected Benefits are key determinants of E-Learning implementation
success in terms of Internal Integration and External Diffusion.

Mechanical and Tribological Behavior of Glass- Polyester Composite System under Graphite Filler Content

Farag M. Mohammed; Drai A. Smait

Engineering and Technology Journal, 2012, Volume 30, Issue 4, Pages 672-683

Experimental investigations had been done in this work to demonstrate the effect of
graphite filler contents on the mechanical and tribological behavior of (30% volume
fraction) glass-polyester composite system. The stress-strain relations, modulus of
elasticity, yield stress, ultimate tensile strength and ultimate compression strength were
studied according to ASTM-D 638-87and ASTM-D 695 to present the composite
mechanical behavior. The wear rate and wear resistance were investigated according to
ASTM-D 5963 using pin on disc machine to present the composite tribological behavior.
The results showed that the mechanical and tribological properties behavior was
improved when the graphite filler content was increased up to 7.5% and then decreased
after that. At 7.5% filler content the modulus of elasticity, yield stress, ultimate tensile
strength, ultimate compression strength and wear resistance increased by (41%, 64%,
24%, 60% and 38%) greater than unfilled composite, while the wear rate was decreased
by 27% less than the unfilled one.

Corrosion Inhibition of Aluminum Alloy 7613 by Dimethylethanolamin in (0.6 M) NaCl Solution

Khalid T. Rashid

Engineering and Technology Journal, 2012, Volume 30, Issue 4, Pages 684-696

The inhibition behavior of Dimethylethanolamin (DMEA) on corrosion 7613
Aluminum alloy in 0.6 M NaCl solution have been investigated using weight loss,
polarization techniques .Five different concentrations (2*10-3, 4*10-3, 6*10-3 ,
8*10-3 and 10*10-3) M of (DMEA) were studded at 250 C. Also examine of
temperature effect (25, 35, 45)0 C on the inhibitor efficiency .The results indicated
that the inhibition occurs by absorption of inhibitor molecules on the metal surface.
The inhibition efficiency (I %) was found to increase with increasing inhibitor
concentration and decreasing with increasing temperature. For inhibitor
concentration close to (8*10-3 M) maximum inhibition efficiency obtained was 92
%. Above this inhibitor concentration value in the solution the inhibitor efficiency
decreases.
Polarization measurements showed that the DMEA act as a mixed type inhibitor.
The corrosion potential (Ecorr.) values shifted to less negative values by increasing
the concentration of DMEA in the solution up to (8*10-3 M). Adsorption of DMEA
on the surface of Aluminum is found to obey the Langmuir isotherm

On Use of Linear and Nonlinear Models to Measure Compressive Strength of Concrete Bearing

Azhar Hadi Mahdi

Engineering and Technology Journal, 2012, Volume 30, Issue 4, Pages 99-116

Statistical and analysis researches are considered important in solving many
problems, and taking suitable decisions, and sometimes predict incoming problems
and solving them in near or far future for specific sphere or to improve the
productivity of any kind of product and other application. Response surfaces method
roots goes back to 1930’s and is considered very important, its applications had a
highly successful results in chemical engineering, agricultural, medical applications,
biological, apart from, simulation in computers. The previous attempts to carry out
these experiments according to linear and nonlinear models to estimate the
parameters. This research has adopted the least square method in cases of
linear regression and (Marquardt method) in case of nonlinear models which
are distinguished with accurate parameters, also to solve multiple linear relationships
problem between independent variables if it was exist. This method has been applied
to study compressive strength for concrete in ages 3, 7, 28 days and the results were
concluded from practical experiment according to complete random design (3*3) in
bearing concrete (with standard specifications) compressive strength. In order to get
minimum estimation for relationship between bearing concrete to compressive
strength and independent variables represents by percentages (sand and gravel) and to
fix water cement ratio. Experiments were varied each time percentage of sand and
gravel and measure compressive strength for any age mentioned. Results have been
analyzed statistically to find the best suitable model with high efficiency in
application from the statistical models used in this research along with random
design.