Print ISSN: 1681-6900

Online ISSN: 2412-0758

Volume 30, Issue 20

Volume 30, Issue 20, December 2012, Page 420-3652


Experimental and Theoretical Study of Heat Liberation of Reciprocating Air Compressor

Haqi Ismael Qatta

Engineering and Technology Journal, 2012, Volume 30, Issue 20, Pages 3474-3490

In this paper an approach is presented to estimate the temperature , heat
transfer rate and heat liberation of a reciprocating air compressor . The
experimental work was performed by using double cylinder compressor
working by three stages to reach the final pressure. In the experimental work,
recording the final pressure for three stages ,and recording the temperature
at suction valve, delivery valve and the cylinder wall . In the theoretical part
a computer program used to solve model of single zone and depending on
step by step , and calculating the amount of heat liberation by analysis
pressure diagram ,the program depend upon the first law of thermodynamic
and gases .
The result that shown the maximum temperature inside compression
space from TDC , also the rate of heat liberation increased with increase of
compressor speed.

Theoretical Prediction of Cavitation in Radial Inflow Turbines at Design and off-Design Conditions

Jafar M. Hassan; Mohammed I. Mohsin

Engineering and Technology Journal, 2012, Volume 30, Issue 20, Pages 3491-3505

A theoretical method for the prediction of cavitation in hydraulic radial turbines is
developed in this work. The method combines a steady, quasi-three dimensional
analyses which are based on the streamline curvature technique with an approach for
the prediction of cavitation based on the definition of "available" and "required"
cavitation coefficients. A radial inflow turbine is selected as a test case to investigate
the capability of the present method as a cavitation prediction tool at design and offdesign
conditions. The effects of various operating conditions on the cavitation
inception are examined at constant values of total head and turbine suction head. It has
been found that cavitation is formed near the outlet when the turbine operated at the
design speed. While at off-design speeds and flow rates, cavitation covers longer
distances along suction and pressure surfaces.

Numerical and Experimental Investigation of Plate Buckling under In-plane Loading

Naseer Hamed Farhood

Engineering and Technology Journal, 2012, Volume 30, Issue 20, Pages 3506-3523

The objective of this work is to predict the plate elastic buckling includes
critical buckling load and corresponding buckling mode for stiffened and unstiffened
plate under in-plane loading. The numerical study has been achieved by
employing the FEM (ANSYS package ver.11) using a shell element of eight nodes
with five DOF at each node as a discretization element such that the equation of
elastic stability with isotropic material properties has been taken into consideration
studies.
The study of aluminum alloy 6063-O plates subjected to in-plane loading showing
the effect of stiffened plates, stepped thickness, and changing of applied loading. It
has been found that buckling strength increases when plate width (b) increase for
stiffened and unstiffened plate, also critical buckling load has high values for
biaxial load than uniaxial for plates with the same specification. Also, an
experimental test has been performed on different cases which exhibit a good
verification of results.

The Use of Okra as a Coagulant and Coagulant Aids in the Removal of Heavy Metals of Solid Waste Leachates

Adnan A. Al-Samawi; Ako R. Hama

Engineering and Technology Journal, 2012, Volume 30, Issue 20, Pages 3524-3535

Coagulation-Flocculation processes play an important role in the treatment of water
and wastewater. Aluminum sulfate (alum) and polyelectrolyte (polymer) are the
common chemical coagulants which are used in this process. The produced leachate in
waste disposal places is considered to be one of the highly contaminated resources
from the physical, chemical, and biological point of view.
In Sulaimaniah, Tanjaro was found to be one of those solid waste landfill areas.
Okra is used for the treatment of raw leachate samples that obtained directly from
Sulaimaniah – Iraq solid waste sanitary landfill area. Fresh solid waste samples of the
leachates were taken and tested for their heavy metals concentrations contents. It was
found that the leachate contains a high amount of heavy metals of cadmium,
chromium, copper, nickel, and zinc. By using conventional coagulants of alum,
polymer and natural indigenous okra (as a primary coagulant or in combination with
the other two primary coagulants) and by the jar testing, the best concentrations and pH
values of the coagulants were determined. Analyzing the results, it was found that the
optimal pH values were 6.65, 9.00 and 7.00 for alum, polymer and okra, respectively.
In addition, the best dose of alum was1400 mg/L in which a removal of heavy metals
yielded 45-80 %, while the best dose of polymer was 500 mg/L in which a removal of
70-95% was achieved. For okra, the best dose was 500 mg/L in which a removal of
heavy metals yielded 20-100%. It was found that okra has an efficient coagulation
power with respect to alum and polymer in removing heavy metals elements in solid
waste leachates.

Experimental Studies On Shear Connection Between Steel and Steel Fibered Concrete Using Studs

Khudhayer Najim. Abd-Allah

Engineering and Technology Journal, 2012, Volume 30, Issue 20, Pages 3536-3552

This paper aims mainly to study the effects of using steel fiber in reinforced
concrete parts of composite structural elements, which consist of two main parts, the
steel and concrete sections. Then to explain the effects of using the hooked ended steel
fibers on the load-slip relationship between concrete and steel parts of composite
structural elements.
The standard push-out test is a convenient and the only available method to define
this load-slip relation. There are five series of tests made on push – out test specimens
prepared for this purpose. These tests are containing various percentages of steel
fibers ( 0.0%, 0.5%, 1.0%, 1.5% and 2.0% ) by volume of concrete. The hooked ended
steel fiber with aspect ratio 100 were used in reinforced concrete parts of composite
structural elements, which consist of two main parts (the steel section and the concrete
section).
From the obtained results, an empirical non-linear equation was developed, to
calculate the shear stiffness for connectors at any amount of slip. This will give
information on the ultimate shear capacity of the shear connector, which were used in
the composite structures and the corresponding load-slip relationship.

Text Hiding Using Artificial Neural Networks

Haider Tarish Haider; Faiq Sabar Baji; Ahmad Saeed Mohammad

Engineering and Technology Journal, 2012, Volume 30, Issue 20, Pages 3553-3564

The growth of information technology and data transfer led to increase the data
attacks, so that information security becomes an important issue to keep the data
saved during information exchanges in computer networks. Steganography
techniques used to protect the information from being detected. The art of
steganography will hide secret information into cover data, which will be sending
without any change so the attack does not recognize any change into cover image.
This paper use the Steganography and artificial neural networks to presents an
information hiding procedure for hiding text in cover image, the secret text will be
converted to binary code, also the cover image will be converted to the binary data
in form of vectors. The supervised learning of neural networks will use binary
patterns of hidden text as set of input values, and the corresponding cover image
data as target that used as teacher signal to neural network. The generated weights
from neural network and the coordinate of data block of cover image have been
saved and then used to extract hidden text data.

Optical Properties of Tin Oxide Nanostructure Thin Films Prepared by Simple and Classical Method

Rana Osamah Mahdi

Engineering and Technology Journal, 2012, Volume 30, Issue 20, Pages 3565-3572

In the present work, preparation of transparent conductive SnO2 thin films by
classical-oxidation technique of thermal evaporated tin metal films, on glass substrates
was carried out. The optical properties showed high transmission at visible and NIR
regions. The energy band gap was found to be (3.82eV). The structure properties
showed that the tin oxide peak appears at (2q =30.24) and (2ϴ=63.39°) . The atomic
force microscopy (AFM) results showed a nano-structured for the thin film with
particle size ranging (15-140)nm and its root mean square (RMS) value was found to
be (5.72 nm ).

Study the Effect of Volume Fraction of Mica With Different Particle Size on the Mechanical and Electrical Properties for Unsaturated Polyester Composites

Rafah A.Nasif

Engineering and Technology Journal, 2012, Volume 30, Issue 20, Pages 3573-3580

This study was carried out to investigate the effect of adding mica (5, 10, 15, 20, 25
% vf) with variable particle size (35, 57, 70μm) on the mechanical and electrical
properties of the unsaturated polyester composites. Some mechanical tests were carried
out like (impact strength, flexural strength) and dielectric strength. Flexural strength
and dielectric strength were found to increase with filler concentrations whereas impact
strength was found to decrease at higher concentrations for all particle size.

Influence of Shape Design of MEMS (Micro-Cantilever Based Sensor) on High-Sensitivity

Ibtissam Mahdi Shihab

Engineering and Technology Journal, 2012, Volume 30, Issue 20, Pages 3581-3595

In this paper, a novel analysis was carried out on the biosensor microcantilevers
in order to increase the sensitivity of a micro- cantilever based
biosensor piezoresistive. Holes were made and compared with the basic
rectangular (R), triangular (T), and step(S) profile cantilever. Effect of changing
the micro-cantilevers profile and its cross-section shape was investigated. A finite
element ANSYS was used to analyze these models. The micro-cantilevers are
made of silicon with elastic modulus 130Gpa and poisson’s ratio 0.28. Several
cases were studied by making one, two and three holes in each biosensor
piezoresistive micro-cantilevers (rectangular (R), triangular (T), and step(S) profile
cantilever). Results showed that triangular micro-cantilever with two holes (T22)
has the better sensitivity, also showed T12 respectively 61.7% and 65% higher
sensitivity than R12, S12.

Comparative Study of Cellular Immune Response in Cutaneous Blastomycosis

Haider Faisal; Hiba T. Hussain; Azhar A. F. Al-attrraqhchi

Engineering and Technology Journal, 2012, Volume 30, Issue 20, Pages 3596-3602

Background: The immune response against Blastomyces dermatiditis is less
clear than that of Histoplasma spp. or Coccidioides spp. This study was done to
evaluate the cellular immune host response in patients with ulcerative and
verrucous skin lesions.
Methods: This study was conducted on 50 patient attended Al-Kadhymiah
Teaching Hospital/Dermatology Dep. in Baghdad (2009-2010). After processing of
skin samples, all cases were studied for various lymphocyte subtypes by using
direct dual immunofluorescence staining method. Independent sample t-test was
used to make a comparison between groups and p-value <0.05 was considered
significant.
Results: Histopathological examination showed 4 biopsies of skin lesions were
Blastomyces dermatitidis positive and 46 biopsies were negative, two cases were
ulcerative and two were verrocous . According to this classification, the total cell
counts, CD3+ cells was found statistically different (p=0.034). Plasma cell (CD19),
T-helper (CD4) and T-cytotoxic (CD8) also were significant when p values were
(p=0.046), (p=0.020) and (p=0.018) respectively. According to the type of lesion
whether it is ulcerative or verrocous, CD3+, CD4+, CD8+ and CD19+ counts for
each type were significant when, P value were (p≤0.001, p=0.003, p=0.026 and
0.050) respectively. However, there were no significant difference was seen for
these cells (p>0.05) among negative lesions.

Extractions of Tin Metal from Electronic Circuit Scrap by Wet Techniques

Mohammed A. Abbas

Engineering and Technology Journal, 2012, Volume 30, Issue 20, Pages 3603-3615

According to the larger accumulation of electronic equipment, then new
environmental techniques (wet extraction process) are studied to treat these
scrap and produced a utilized metal such as tin metals that used in different
industrial processes.
Different experimental are carried out in this studied in order to optimize the
production of Tin metal from scrap circuits (stannous chloride) such as
temperature of reaction (30, 35, 45, 55, 60 c°) concentration of scrap
introduced (5.0, 7.0, 10.0, 13.0, 15% wt.) and residence time through smelting
step as (2.0, 2.5, 3.5, 4.5, 5.0 hrs) respectively.
A characterization and monitoring for production metals occurred by the use of
x-ray scanning electron microscope to scan the internal structure of Tin metal,
also an atomic absorption to determine the concentrations of Tin agglomerates.
The results show that; optimum conditions that produced high percent of
Tin metal from stannous chloride are (53°c temperature of residence, 8.5 wt%
concentration of and 4.7 hrs residence time for reduction step at 2°c/min
rating ratio). Afterward for smelting stage are (388°c curing temperature and 5
hrs residence time).
Also the characteristic results proved that; agglomerate of Tin metal
products appeared at these optimum conditions at x-ray and atomic absorption
as 0.25 wt. % for standard blank metal as Cu and clear agglomerate of Tin
metal in the electron microscope.

Mathematical Modeling of Hybrid Cooling Tower for Steam Power Plant

Hashim A.Hussain

Engineering and Technology Journal, 2012, Volume 30, Issue 20, Pages 3616-3636

An economical and environmental requirements of hybrid cooling tower in
steam power plant are represented by decreasing of outlet water temperature,
reducing of water and energy consumption, and working without mist formation.
The present work is devoted to study and determine the best contact method of dry
and wet tower to build hybrid cooling tower.A three suggested models differs in
contacting method of air and water are studied. Analysis of these models are
dependent on the basic principles of thermodynamics ,mass and heat transfer with
considering of initial and boundary conditions. The best model must be giving
accepted values in economical and environmental requirements. A Computer
program by Matlab is used for solving the governing equations and determining the
suitable mathematical model. The results are indicated that the third model (air in
series and water in parallel) is the best in contacting method which satisfied the
economic and environment requirements .The results are recorded and represented
by graphs.

Study of the Wind-Induced Dynamic Response for a Parabolic- Trough Solar Collector

Mauwafak Ali.Tawfik; Bahaa.Ibrahim.Kazem; Haider.Hussein.Hamad

Engineering and Technology Journal, 2012, Volume 30, Issue 20, Pages 3637-3652

In this paper, the dynamic response of parabolic-trough due to wind loading was
conducted in different flow field environment and configurations experimentally
and numerically. First, Experimental modal analysis (EMA) was performed to
evaluate the vibrational characteristics for prototype of parabolic trough that
manufactured for this purpose. Direct pressure sensors array were used to measure
the pressure values over the parabolic trough model surface due to wind load at
different operational attitudes. Then, the dynamic response (displacement) of the
parabolic-trough due to measured wind loads (pressure) was measured
experimentally and numerically. The numerical solution for dynamic response was
performed using the finite element approach. The response of the parabolic-trough
to wind loads was evaluated for different wind velocities and different angles of
attack. A comparison between these results was made to verify the effect of the
angles of attack and wind velocity on the dynamic response. The results showed
that the suggested approach gave good indication for evaluating the wind load
effect on the dynamic response of parabolic trough the solar collector.

Finding the Weight Loss Rate of Metallic Surfaces Exposed To Corrosion Presence of Vibration (Corrosion - Vibration)

Mouhmad Abdultef Ahmed

Engineering and Technology Journal, 2012, Volume 30, Issue 20, Pages 448-462

In this research the structural steel type (A36) samples were prepared by
traditional preparation operations , chemical composition of samples was analyzed
, hardness tested, then testing corrosion was achieved for two major cases, a
general corrosion case when the corrosive medium (sea water) is static for five
days period ,and the second case is the corrosion with presence of mechanical
vibration, which included two branch cases , first case; corrosion of vibrated
samples with the vibrated corrosive medium, and the second case when the
samples are fixed and corrosive medium is vibratory , a total test period is five
hours for each case ,then found weight loss and the corrosion rate of all cases of
corrosion mentioned by a traditional weight loss method , as well as study the
microstructures before and after the corrosion cases and to find an experimental
mathematical formula that illustrate the relationships between corrosion and
corrosion with presence of vibration, note that the used device to study the
mechanical vibration effect was locally designed and manufactured, according to
the modified American Standard (ASTM G32).Observed that the weight loss and
corrosion rate reached the highest value in the second case of corrosion with
presence of mechanical vibration (fixed samples and corrosive medium is
vibratory), followed by the first case of corrosion with presence of mechanical
vibration (vibrated samples with the vibrated corrosive medium), and less the value
of the corrosion rate and weight loss is the state of general corrosion (corrosion in
the static medium). It was noted that the microstructure of the structural steel
became uniformly corroded after general corrosion case (in static corrosive
medium) and corrosion regions were spread or scattered over all parts of the
sample surface on a regular basis, while the microstructure in the two cases of
corrosion with presence of mechanical vibration containing irregular corrosion
cavitations and scattered randomly on the surface, and more deeply especially the
second case (fixed samples and corrosive medium is vibratory). Illustrated from the
results and carves there was relationship between mentioned corrosion cases, it was
an experimental mathematical formula:
Acc.C.R.= Vib-C.R2 – ( Vib-C.R1 +Static C.R.)

Laboratory Study of Protecting Downstream Slope of Rockfill Weirs Using Stepped Gabions

Ghania Aed Al-Majeed Hayawi; Bahzad Mohammad Ali Noori

Engineering and Technology Journal, 2012, Volume 30, Issue 20, Pages 420-447

In the present investigation, the stability of rockfill weirs protected by gabions and subjected to overtopping flow rates under the effect of high flow rates have been studied experimentally. Five weir models with different downstream slopes [1V:2.5H,1V:3H,1V:4H,1V:5H,1V:7.5H]were constructed and tested. Fifty eight experiments were conducted for five cases of stepped gabions laying on the downstream slope[ laying gabions with one layer and no connections (M-1),laying gabions with lateral connections (M-H),laying gabions with longitudinal connections (M-V), laying gabions with two layers(M-2),and laying gabions with three layers(M-3)] using three gravel diameters (11.11,15.9 and 22.25)mm.From
the data analysis, a set of equations were obtained for the estimation of failure unit discharge in terms of equivalent gravel diameter, relative submerged intensity of gabions, gabions layer solidity, and tangent of internal friction angle of gabions, for each case of gabions laying. A simple method was presented for the design of rockfill weirs protected by stepped gabions in terms of maximum failure discharge
with the help of design charts obtained from the present study.
A mathematical model depending on the characteristics of the physical
model was derived for each slope giving failure unit discharge values that agree quite well with the experimental values. Comparing results of the present study with those of other investigations shows that rockfill weirs protected by gabions stand much higher failure unit
discharge than earth weirs protected by gabions.