Print ISSN: 1681-6900

Online ISSN: 2412-0758

Issue 16,

Issue 16


Retarding of Precipitation Hardening of Al-Cu Alloy by Cadimium Addition

Sabreen Ali; Alaa A. Atiyah; Amin D. Thamir

Engineering and Technology Journal, 2013, Volume 31, Issue 16, Pages 2997-3006

The aim of the present work is to prepare a set of Al-Cu alloys with slow
precipitation hardening by aging. Present work results can be utilized during the
importing or exporting of such alloys at solution treatment conditions. In order to
establish this aim, a set of Al-4%Cu alloys have been prepared in the laboratory to
investigate the effect of Cd-addition with the percentage varied from (0.1, 0.3 and
0.5) weight percentage. The prepared alloys with different Cd additions were
subjected to a natural aging up to 60 days after solution treatment. As a result, the
alloys showed an obvious retarding in the aging kinetics as the percentage of Cdadditions
increasing. This retarding was found to be due to the trapping of the
vacancies that resulted during the quenching step that resulted in delays of Gunier-
Preston zones precipitation. SEM has been used in monitoring of microstructure as
well as optical microscopy

Modeling and Simulation of the Cogeneration Plant Equipped with Back-Pressure Turbine Operates at Various Control Programs of Exit Steam Temperature

Moayed Razoki Hasan; Mohammed Jasim Salih

Engineering and Technology Journal, 2013, Volume 31, Issue 16, Pages 3007-3034

Cogeneration represents one of the main ways for increasing the efficiency of
primary energy use. This paper deals with a theoretical analysis of cogeneration
plants equipped with various back-pressure turbines type R. These plants are studied
during their operation with conventional method (water injection) and the suggested
method (sliding live steam temperature) to regulate steam temperature supplied to the
industrial consumers. A computer program had been written to work under MathCad
software to simulate cogeneration plant with each back-pressure turbine under design
and off design conditions. The performance of the different schemes is analysed in
view of the first and second laws. In this analysis entropy method (second law) in
addition to more conventional energy analysis (first law), are employed to evaluate
overall and component efficiencies, fuel consumption and to identify the
thermodynamic losses. The results show that, using the suggested method leads to
increase the overall efficiency of the cogeneration plant for all types of back-pressure
turbine and can reduce the fuel consumption. Finally, the results show that increasing
back-pressure leads to improve the performance of cogeneration plant regardless of
the method used.

Characterization of Niti Super Elasticity Shape Memory Alloys

Rasha Ali Hussein; Emad S. Al-Hassani; Sahib M. Al-Saffar

Engineering and Technology Journal, 2013, Volume 31, Issue 16, Pages 3035-3051

Ni-Ti samples were prepared by powder metallurgy. The prepared samples
were master samples M1 (55% Ni- 45%Ti) and M2 (56% Ni- 44%Ti). The
additive percentage of Ta was 5%, 7% and 9% to master sample M1 and M2,
while Nb addition was 1%, 2% and 4% to M1 and M2. The pressure of
pressing was 800 Mpa. The samples were sintered at 950 °C for a time of 9 hr.
Samples were then examined by using SEM technique, XRD, DSC, Vickers
hardness. The porosity was measured according to Archimedes method.
Scanning electronic microscopy images showed that most prepared
samples have porosity, which in turn imparts decreasing microhardness values across the surface. Better increase of microhardness values is found in M2+5%Ta. Scanning electron microscopy indicated also the best martensitic structure in M1+4% Nb and M2+4%Nb. X-ray diffraction observations indicated that NiTi, Ni3Ti and NiTi2 phases exist in all samples. NiTi phase is playing a dramatic role in enhancing shape memory effect and superelasticity.
DSC results show that transformation temperatures range in (46-134°C). This indicates that all samples at room temperature have one phase which is martensite.

Deformation Characteristics of Base and Subbase Layers under Monotonic & Cyclic Loading

Omar Abbas AL-Azzawi; Namir. K.S. AL-Saoudi; Falah Hassan Rahil

Engineering and Technology Journal, 2013, Volume 31, Issue 16, Pages 3052-3060

Base and Subbase layers are considered as the platform for distributing the
different applied stresses in flexible pavements. The two layers must provide
sufficient strength to resist any excessive generated deformation to achieve this goal,
proper compaction machinery is essential to reach the required degree of compaction.
The present paper investigates the influence of degree of compaction of the base
and Subbase layers on the generated deformation under the action of both monotonic
and cyclic loadings. Model tests were performed by compacting beds of base and
Subbase layers to relative densities of 65%,77% and 88%, inside steel container of
dimensions 1000mm*750mm*750mm. The final thicknesses of the base and Subbase
layers were 150mm and 350mm respectively.
A circular model footing of diameter 175mm: equivalent to 24194 mm tire
contact area is placed on the base layer and subjected to a series of monotonic and
cyclic loadings. The results of monotonic tests revealed an increase of 71% and 107%
in the carrying capacity when the relative density increased from 65% to 77% and
from 65% to 88% respectively.
The cyclic tests revealed a substantial increase in the number of cycles at any
stress level as the relative density increases from 65% to 77% and from 65% to 88%.

Preparation and Characterization of Porous Anodic Alumina membrane

Ahmed. A. Hashoosh; Kahtan. K. Al-Khazraji; Ahmed. A. Moosa

Engineering and Technology Journal, 2013, Volume 31, Issue 16, Pages 3061-3066

Porous Anodic Alumina (PAA) was prepared by two-step anodization on both sides
of an aluminium foil. The anodization carried out at anodizing temperature 17oC using
oxalic acid as an anodizing electrolyte. The (PAA) template was characterized with
optical microscope and SEM. The optical microscope image showed two (PAA) layers
after the dissolution of the residual aluminium. The average pore diameter was found to
be (75) nm. The average interpore distance of (PAA) prepared was found to be (99) nm.
The thickness of (PAA) was found to be (59.5) μm.

Optimal Sizing of Photovoltaic Irrigation Water Pumping System in Samara

Ali H. Al-Hamdani; Majed Hassan; Roshen Tariq Ahmad

Engineering and Technology Journal, 2013, Volume 31, Issue 16, Pages 3067-3077

Water pumping from wells and rivers for irrigation is a well established
procedure on many farms in Iraq and is practical on various levels around the world.
Typical irrigation systems consume a great amount of conventional energy through
the use of electric motors and generators powered by fuel.
The overall objective of this research was to determine the feasibility of using
photovoltaic (PV) modules to power a water pump for a small-scale irrigation system
in the North-West of Iraq (Samara). The study involved field observations,
simulations of global solar radiation and PV electrical output.
Field observations involved an installation of 24-monocrystaline silicon PV
modules as shown in figure (1). This system was installed to give maximum power
equal to (1960 watt) with maximum open circuit voltage (Voc = 175 volts) and
maximum short circuit ( Isc= 14 Amp ). This module was connected to the pump via a
charge controller and AC inverter. The parameters monitored were voltage, current,
back-of-panel temperature, pressure, and flow. These observed parameters were used
to determine PV electrical output and volume of water pumped. Site latitude,
elevation, and panel tilt were applied to the solar radiation and PV electrical output
models. PV electrical output and volume of water pumped were monitored between
January 2000 and December 2000. As expected, an increase in power causes an
increase in the volume of water pumped.

Carbon Nanotube Prepared by Pulse Laser Ablation of Graphite Target in Iso-Propanol Solution

Khawla S. khashan; Mayyadah H. Mohsin

Engineering and Technology Journal, 2013, Volume 31, Issue 16, Pages 3078-3089

In this work carbon nanotube was synthesis by pulse laser ablation of graphite
target in Iso-propanol solution. Fourier Transform Infrared Spectroscopy (FTIR),
UV-Visible Spectrophotometer and Transmission Electron Microscopy (TEM)
were used to study chemical bonding, optical absorption, particle size, structure
and morphology of the carbon nanotube. The FTIR absorption peak at 2335.6,
1647.1 cm-1& 1269.1 cm-1 stretching vibration bond, it is inferred that the C ≡ C ,
C = C and C-C, respectively. Bonds suggests the formation carbon nanoparticles
suspend in this solvent, UV absorption peaks coincide with the electronic
transitions corresponding to linear hydrogen – capped polyyne (Cn+1H2), polyynes
are important precursor molecular components in the formation of carbon
nanotubes. The TEM show the aggregation of the carbon nanoparticles with size
ranges from (1.66 to 41.6 nm), the structure and morphology of the CNT’s with
diameter at range 11.1 – 46.15 nm and length at range 261.1 - 592.3 nm.

Mechanical Properties of Reactive Powder Concrete (RPC) with Various Steel Fiber and Silica Fume Contents

Lubna S. Danha; Wasan Ismail Khalil; Hisham M. Al-Hassani

Engineering and Technology Journal, 2013, Volume 31, Issue 16, Pages 3090-3108

An experimental work was carried out to investigate some mechanical properties
of Reactive Powder Concrete (RPC) which are particularly required as input data for
structural design. These properties include compressive strength, tensile strength
(direct, splitting and flexural), flexural toughness, load-deflection capacity and static
modulus of elasticity. The effects of three variable parameters on these properties were
carefully studied which are, the silica fume content SF (0%, 10%, 15%, 20%, 25%, and
30%) as a partial replacement by weight of cement, hooked macro steel fibers volume
fraction Vf (0%, 1%, 2% and 3%) and superplasticizertype(Sikament®-163N and
PC200).The diameter of the steel fiber is 0.5mm and its length is 30mm with aspect
ratio 60.The experimental results showed that as the silica fume content (SF) increases
from 0% to 30% the compressive strength significantly increases, while the increase in
tensile strength is relatively lower. The inclusion of steel fibers leads to a considerable
increase intensile strength, while the addition of steel fibers causes a slight increase in
compressive strength of RPC as fiber volume fraction increases from 0% to 3%.The
increase in the steel fibers volume fraction and silica fume content improved the loaddeflection
behavior and consequently gave higher ductility and fracture toughness of
RPC.

The Effect of Operating Factors on the Pollutants Emission from a Constant Pressure Burner

Abdul Al-Kadhim M. Hasan; Abdul Sattar Jawad M.Hasan; Riyadh Salman Radhi

Engineering and Technology Journal, 2013, Volume 31, Issue 16, Pages 3109-3124

This paper presents the effect of varying operating conditions on pollutants
emission (carbon monoxide [CO], unburned hydrocarbon [UHC], and Soot) from
constant pressure burner. In this research a liquid fuel used are gas oil and
kerosene .The operating conditions which taken in account are atomization
pressure, inlet air temperature, equivalence ratio, as well as type of fuel.
It is found that the Carbon monoxide and Unburned hydrocarbon are inversely
proportional to inlet air temperature with maximum decrease of (95%, 43%)
respectively. In contrast, soot is directly proportional to inlet air temperature as the
maximum increase in soot emission is 170%. Carbon monoxide , Unburned
hydrocarbon , and Soot are inversely proportional to Atomization pressure as the
maximum decrease in Carbon monoxide , Unburned hydrocarbon, and soot
emissions are (56.5%, 37.4%, 76%) respectively. The relation between Carbon
monoxide, Unburned hydrocarbon, and soot with equivalence ratio is directly
proportional as maximum increase in Carbon monoxide, and Unburned
hydrocarbon emissions are (130%, 81 %,) respectively, while soot emissions is 190
%. Emissions from a constant pressure burner depend on the physical and chemical
properties of fuel used, such as (viscosity, surface tension, volatility, the ratio of
hydrogen atoms number to carbon atoms number (H/C), and lower heating value).
it is found that the maximum increase in Carbon monoxide, Unburned
hydrocarbon, soot emissions from gas oil are generally higher than those from
kerosene fuel by (72%,17.5%,38%) respectively`.

Soil Site Investigations Using 2D Resistivity Imaging Technique

Hussein H. Karim; Mohammed A. Al-Neami; Wisam M. Y. Mohammad

Engineering and Technology Journal, 2013, Volume 31, Issue 16, Pages 3125-3146

The use of 2D Electrical Resistivity Imaging (ERI) technique in combination with
geotechnical and geological data allow the determination of the lithological
composition and detailed internal architecture of the subsurface and understanding the
characterisation and description of the geology of the site. This study is aimed to
evaluate the use of 2D ERI for the detection and characterisation of heterogeneities in
subsurface soil. The survey was conducted using a Wenner-Schlumberger and Wenner
configurations along thirteen ERI parallel profiles which have been investigated in the
project of Al-Obaidi Electrical Transformation Station site to find the resistivity and
depth of soil horizons with their lithological description. Analysis of imaging sections
shows that Wenner-Schlumberger sections are with higher resolving power than
Wenner sections in both horizontal and vertical variations in resistivity reflecting more
pronounced soil horizons with depth, where Wenner sections are limited to the upper
soil layers. Resisitvity values in the imaging sections indicate that the stratigraphy of
the study area is mostly of clayey soil. 4 to 7 distinct geoelectric layers generally
identify the subsurface down to depth of about 20 m. High resistivity values in the top
soil, medium-high resistivity values representing the upper soil layers, while lower
reistivity values are indicated for the lowerest layers. The resistivity values are
inversely proportional to many soil properties such as fine content (clay and silt), salt
content (sulphate and gypsum content) for saturated conditions, water content,
plasticity index (P.I) and void ratio particularly for saturated condition. The resistivity
values are directly proportional to sand content, void ratio, salt contents for dry
condition. The integrated use of ERI technique and conventional site investigation has
led to a far better understanding of the site than could have been achieved using site
investigation methods alone.

Prediction and Investigation Particulate Fillers (Aluminum &Alumina) Effect on the Thermal Conductivity of Polymeric Matrix Composite (Polyester)

Hasan A .Alasady; IbtihalAl-Namie; Ahmed A.M

Engineering and Technology Journal, 2013, Volume 31, Issue 16, Pages 3147-3158

The main objective of this paper is to study the thermal conductivity of composite
materials and the parameters affecting it, then to determining the validity of the best
theoretical model matching with experimental results and to predict thermal
conductivity of any composite materials with different particle size.
Alumina& aluminum filled thermoset polyester composites are investigated in this
study, and their thermal conductivity will be the central focus. Aluminum particle,
alumina particle and aluminum fiber (5wt % to 45wt %) were added to polyester
matrixes. It was found that both fillers and fiber positively effect on the thermal
conductivity of the composite. By using visual basic program, the results show there
are three different theoretical models (Maxwell Equation, Lord Rayleigh Equation
&Lewis and Nielsen Equation) valid to predict the effective thermal conductivity for
reinforced the polyester by Al and Al2O3 powder until 35wt% and 45wt% respectively.
In addition, the rule of mixture model is good to predict the effective thermal
conductivity (for aluminum fiber parallel with polyester matrix).

Corrosion Behaviour of Aluminium Alloy 7020-T6 welded Joint in Sea Water at Different Variables

Huda Mohammed Abdulaziz

Engineering and Technology Journal, 2013, Volume 31, Issue 16, Pages 3158-3185

were welded by using inert gas metal arc welding method (MIG)to obtain butt joint
with geometry of single V at 45⁰with two pass.
The joints were tested by X-ray radiography and faulty pieces were excluded.and
the indefectible joints were subjected to stress relief heat treatment including heating
the joint to evaluating temperature 100 C⁰for one hour and air cooling.Optical
microscopy with camera was used to observe the welded joint microstructure.Micro
hardness test were carried out using Vickers instrument to measure the hardness of the
welded joint.
Corrosion behavior of welded jointspecimens in 3.5% NaCl solution at different
media velocity (1, 2, 3) m/min and temperature of (25, 50, 75) ⁰ C for each velocitywas
examined using Tafelpolarization measurements. It is determined byopen circuit
potential (OCP) after that the cell’s current is changed due to the increasing in
potentialby ±100mV to calculate corrosion current then corrosion rate.
The results show that the corrosion rate is increased with increasing solution
temperature. This is because of the prevention of oxygen from dissolving in water,
while the corrosion rate decreases with increasing velocity of sea water since the
movement of the liquid prevents the formation of deposits and ions gathering on
cathode pole where corrosion can easily develop.
when comparing corrosion rate between the welded and unwelded samples, the
welded samples gives more corrosion rate value since the cycle of heating and cooling
that occurs during the welding process affects the microstructure of welds.

Insertion of Rotational Effects to the Calculation of J-Integrals Using Finite and Boundary Element Methods

Ameen Ahmed Nassar

Engineering and Technology Journal, 2013, Volume 31, Issue 16, Pages 3186-3193

The calculation of J-integrals for cases with rotational effects using the finite or
boundary elements needs special treatment. In this work, an attempt is made to
derive the J-integral expressions for cases with rotational loading conditions. New
useful ideas for reducing domain integrals to boundary integrals and improving the
accuracy of J-integrals are developed. The new ideas are implemented in finite and
boundary element programs which were developed and validated in this work by
taking a case study of central-cracked rotating disc with known analytical solution.
The results of the developed programs show good agreements with the analytical
solution.

Fabrication of Tio2 and V2o5 Thin Films by Powder Coating Technique

Mohammed S. Hamza; Alaa Aladdin; Shatha Kazem

Engineering and Technology Journal, 2013, Volume 31, Issue 16, Pages 3194-3202

Titanium dioxide (TiO2) and vanadium oxide (V2O5) in different mixing percentage
(100, 50, 0)% from them powders as thin film on substrate of glass .the coating
thickness was ( 0.37 ±0.03 μm ).
Thin films were inspection by microphotographs with scanning electron microscopy
(SEM) and x-ray diffraction (XRD).
The results showed that thin films was prepared crystalline and also the compound
(tio2, v2o5), and the structure was regular and smooth.

Flutter Estimation for Low Speed Aircraft Wing Using Fully Coupled Fluid – Structure Interaction

Mauwafak Ali Tewfik; Mohammed Idris Abu-Tabikh; Hayder Sabah Abd Al-Amir

Engineering and Technology Journal, 2013, Volume 31, Issue 16, Pages 3203-3215

The aero elastic responses and the flutter condition of 3-D flexible aircraft wing
were estimated by developed fully coupled fluid-structure interaction approach. The
actual wing in this approach was represented by an equivalent plate .Equivalent
plate model (structure model) based on assumed mode method was then combined
with unsteady panel-discrete vortex method (aerodynamic model) to build relatively
simple aeroelastic model. This model could be used for estimation of flutter
condition of moderate to high aspect ratio and low sweep wings of aircraft flight at
low subsonic speeds. The obtained results from the present model are able to
prediction the flutter condition of the actual wing at different angles of attack. The
increasing in the angle of attack leads to reduce flutter speed and flutter frequency.