Iraqi journal of mechanical and material engineering

The research was achieved in the center of prosthesis manufacturing ( Sadr
Al– Qanat Factory for Prosthesis and Orthoses), and Baghdad Factory/Ministry of
Health and Prosthesis and Orthoses workshop (Belong to Technical Medical
Institute). The research made a study on a sample of (60) handicapped in the kind of
partial foot amputation for the foot kind (Chopart).The material used in manufacturing
the socket was plastic or leather or the two materials together. It was found that the
maximum percentage of failure was (55%) for the socket made from plastic and the
cause of failure was fracture where as the minimum percentage was (15%) for the
socket that made from leather and the cause of failure was fracture. Either for the
height of the socket It was found that the maximum percentage was (50%) for the
socket of height with knee level and the cause of failure was fracture, where as the
minimum percentage was (15%) for the socket of 1/3 distance between the knee and
ankle joint and the cause of failure was fracture also. Either for the motion of ankle
joint it was found that the maximum percentage was (60%) for the socket of no
motion and the cause of failure was fracture where as the minimum value was (15%)
for the socket of no motion but the cause of failure was the shape change of the
socket.

In this study, it is acquainted with the kinetics of the chemical and
electrochemical reactions by modeling and understanding of the essential and
secondary (conjugate) chemical and electrochemical reactions during plating process .
In addition , the effects of various conditions on the speed and kinetic of those
reactions is also considered . In order to apply this manner , the mean-field kinetic
equations and Poisson equation for charged lattice model are adopted using two types
of one-dimensional cells for theoretical part of this study , namely (half and full cell)
of size (100) with an applied potential of ( e / 2 ) . Provided that the cell should
contain two identical electrodes of thickness (10) .A computer program in visual
basic is specially constructed to show the results of this study as it should be .
Through this program the concentrations are determined including (metallic atoms,
cations, anions, solvents, vacancies and electrons) , the charges distribution and
electrical potential across the sites. the results , during the three periods
( 5 10 ) 5 , 3 , 1 (   t ) , showed that under potential application across the cell , the
deposition continues for long time then it is suppressed when the anode reaches
failure limit , and it is observed that the deposition increases with the extension of
space charges at the cathode , from the other hand , the ionic evolution (cation) will
take a peak shape at the cathode , then it has a certain gradient between anode and
cathode. A reversed situation occurs for the anion's evolution. At the same time,
electric potential distribution across the sites becomes higher resulting in deposition
increasing.

The present study includes the effect of applied pressure on elimination the
porosities that formed during both squeeze casting process and pressure die casting.
For pressure die casting the pressure was applied on the full liquid molten alloy
(750oC) where the pressure was applied on molten alloy at (650oC) i.e. the molten was
fifty liquid fifty solid (mushy zone).
The tests and measurements of density, hardness, and microstructure show the
improvement in density and hardness for the samples of both techniques but the
increasing in hardness and density values in squeeze casting were higher than the
values of pressure die casting samples also the test of microstructure shows the
decreasing in (DAS) for the squeeze sample more than the (DAS) of pressure casting
samples.
The above improvement in microstructure, hardness, density belongs to the behavior
of applied pressure in both cases which means that the mushy zone of molten alloy
represents the optimum region to improve the mechanical properties by applied
pressure

In this paper, several specimens from unsaturated poly ester resin with different
filler materials such as (Fe2O3, CaCO3, CaO, Cement, Ca(OH)2( have been
prepared. Three weight percent have been used as (10%,20%, and 30% wt)from each
filler materials. Casting samples are grinded by 800 grit using SiC grinding paper and
then washed by distilled water. Dry sliding wear has been done using pin on desk
test in different period of wear time as (5,10,15,20,25,30 min). it has been shown that
addition of cement with percent (10 % wt) get lower wear rate for unsaturated
polyester resin.

This work applied Artificial Neural Network (ANN) for performance evaluation of
steam condensers which are widely used in power plants and refineries. Two
condensers were experimentally investigated. Experimental data was obtained by use
unit steam power from G.U.N.T Company and industrial condenser operates in Dura
refinery. The commonly used Back Propagation (BP) algorithm was used to train and
test network. Input of neural network include inlet water temperature, water flow rate,
steam temperature and enthalpy difference. The exit water temperature represented
output of the neural network. The maximum deviation between the predicted results
and experimental data was less than 1%. It is recommended the (ANN) can be used to
predicate the performance of thermal system in engineering applications, such as
modeling condenser for heat transfer analysis. Afterwards, ANN resulted used to find
thermal parameters (convection heat transfer coefficient of water side and steam
flow rate ) based on software program built by Matlab language. Comparing the
resulted from modeling with experimental data reveals a good agreement (-3% to
3%).

Potentiodynamic polarization measurements were used to study the effect of
Ellagic acid on biocorrosion of ( 316 L SS ) in Simulated body fluid (Ringer Solution)
was used as the electrolyte .The temperature of the polarization test cell was
maintained at 37±1OC by thermo stated water bath to simulate the human body .The
result from corrosion behavior investigated by electrochemical measurements appear
the corrosion current density of ( 316 L SS ) specimens in Ringer solution containing
Ellagic acid was much lower than the values obtained in Ringer solution without
Ellagic acid .

Experimental study of Heat transfer phenomena in welding process has been carried
out in the present work. The experimental study was carried out on six groups (each
consists of two plates) of low carbon steel material. Each plate is rectangular in shape
with dimensions of (150mm x 200mm) with different thickness, (11mm) for groups
(1) and (2) from A285 grade (B), ((16mm) for groups (3) and (4) from A 285 grade
(C), and (19mm) for sets (5) and (6) from A285 grade (A) using single V-Butt edge
design of joint welding for each group. Data Acquisition System (DAS) was
manufactured and used in order to measure the transient temperature distribution of
the models at the selected positions (channel (1) to channel (10)). The experimental
measurements showed that the maximum temperature occurs close to the fusion
region and starting to decrease a way from fusion region which is called unaffected
base metal passing through the region of heat affected zone. The agreement of the
results are good a comparison with present experimental work. Confirm results that
were carried out experimentally. The agreement of the results is good capability and
reliability the experimental steps of calculating heat transfer in Manual Metal Arc
welding (MMAW).

Electrocoagulation is an electrochemical technique used to treat a high polluted
effluent whereby sacrificial anodes corrode to release active coagulant precursors into
the solution. This research focuses on the performance of EC technique to treat a high
strength wastewater textile industry located in Al-Hilla-Iraq using a batchwise mode.
Several working parameters such as current density, total suspension solid removal
percent, chemical oxygen demand removal percent, turbidity removal percent and the
operating time were studied. It was found that the application of 12mA/cm2 provided
69.2%, 62.5% and 54.3% removal in turbidity, COD and TSS, respectively, while the
application of 20mA/cm2 current density provided 90.1%, 85.2% and 83.1% removal
in turbidity, COD and TSS, respectively, within 60 min. of EC treatment and with an
inter-electrode spacing of 5cm. Also, it was found that the contaminants of treated
textile wastewater such as BOD, COD, TDS, TSS, turbidity, nitrates, chloride, total
hardness, sulfate, total phosphates, electrical conductivity, oil and grease and the total
phenols were within allowable limits for wastewater reuse. The loss of particles due to
electrocoagulation after treatment as a function of operation time was expressed as a
first order kinetic model and the kinetic constant for each contaminant removal was
predicted for each current density.

Free vibration study represents one of the most important studies for complex
structure such as wing structure. In this search, a new model for wing structure was
created including changing in the airfoil shape. The wing of airfoil Naca 2414 of
aluminum 2024 alloy was used to construct the wing. Four case studies were
accomplished for different airfoil shape so that the location of the airfoil is change from
location to other at the chord. Free vibration analysis for five modes was performed to
obtain the vibration characteristics such as natural frequency and mode shapes. From
the results, it was found that, in general the change in the airfoil leads to (keeping
same weight so the thickness and wing length remain constant) increase the
vibration characteristics. A numerical program includes the analysis was achieved and
added to ANSYS milieu as a new motivation.

Connecting rods , are widely used in automotive internal combustion engines .In this paper,
the connecting rod model based on finite element analysis (FEA)is proposed. Critical
location of maximum stress and suitable materials for the connecting rod has been
identified and the contact stress analysis and dynamic behavior of it has been
investigated.The structural model of the connecting rod was utilizing the ( Solid
works) and Steel alloy (C-70) materials. The linear static stress distribution and dynamic
analysis are investigated using Finite Element software package (NASTRAN).For TET10
mesh the linear static stress analysis and the critical location was located at node (174743)
and the critical location for TET4 was at node (110703).Then it can find that TET10 is
able to capture the higher stresses than TET4 for the same global length and size.

Numerical Investigation of the influence of vortex generator on the enhancement of
heat transfer from a wall mounted cube which placed in the middle of a rectangular
channel have been conducted using finite – volume method . The momentum and
convective heat transfer equations were discretized and solve using large – eddy
simulation (LES). In order to study the influence of vortex generator on the flow
structures and heat transfer coefficient, the flow which considered a fully developed
turbulent flow and the convective heat transfer equations were solved around two
cube configurations: a smooth cube and a cube with vortex generator attached to its
surface . The vortex generator used in this paper is a simple rib attached to the top and
the side walls of the cube, in the steam wise middle of the cube . The flow Reynolds
number based on the bulk velocity and the height of the channel was 13000 . The LES
results were compared with the experimental data of [6],a good agreement was
obtained . Also the results showed that the flow in the boundary layer around the cube
with vortex generator is more turbulent and unsteady than the flow around the smooth
cube without the vortex generator. More turbulent structures are generated close to the
surface of the cube resulting in a good mixing of heat and hence high heat transfer
coefficient and this investigation is a efficient way to enhance the heat transfer from
the cube with vortex generator.

This research have been devoted to copper-graphite particulate composites
which have high thermal/electrical conductivities and excellent dry lubrication for
solid contacts and sliding that arise from a synergetic composite effect between
copper and graphite. They have been widely used in their engineering application for
sliding components, such as electrical brushes and bearing .This research is devoted to
study the effect of addition of SiC particles at different weight percentage(1%, 1.5% ,
2% and 2.5% ), to the copper graphite composite as matrix, which consist of (90 wt%
copper – 10 wt% graphite), on the resistance wear under dry sliding condition by
using pin-on-disk technique and hardness, the structure produced by powder
metallurgy methods (P/M).
The results showed that the composite material reinforced with SiC particles has wear
rate lower than that of the base composite where, the wear rate of the base composite
is (2.58 × 10-7), which is become (0.6×10-7) after addition of SiC at (2.5 wt% SiC),
and the results of hardness for the base composite are (25, 7.61) in Vickers test and
Brinell test which respectively become (60, 44) after addition of (2.5 wt% SiC).

To determine the possibility of using polymer powders as reinforcing materials in
the thermoset polymer matrix composite , epoxy as the matrix and carboxy methyl
cellulose (CMC) and polyethylene glycol (PEG 4000) as the reinforcing powders were
used to prepare a particle reinforced composite. In the sample preparation, seven weight
fractions of each powder (0.02, 0.04, 0.06, 0.08, 0.1, 0.12, 0.14) wt% were designed to
determine the mechanical properties of composites that represented by hardness and
compression strength. The results of this research were: for epoxy reinforced with CMC,
the hardness increases with increasing the weight fractions reaching to (78.2 ) at 0.1 wt %
and decreases in other weight fractions while maximum compressive load (7.324kN )
was obtained at 0.12wt %, for epoxy reinforced with PEG4000 the hardness increases
with increasing the weight fractions reaching to (71.1) at 0.06wt % and decreases in other
weight fractions while maximum compressive load (10.449 kN) was obtained at
0.08wt%.

This research concerns with studying the effect of sudden increment in
temperature or thermal shock effect on Stress Intensity Factor generated at crack
region. The Mechanical Stress Intensity Factor (MSIF) was computed using Finite
Element Method technique with the aid of ANSYS software as well as a theoretical
methods. The percent of error as a comparison between these results was about
(3.18%). Elements used for thermal analysis were plane77, then by using switch
element technique from thermal to structural so, elements would be plane82 for
structural analysis. A comparison between this value and the values of Thermal Stress
Intensity Factor (TSIF) which is generated due to thermal stresses in case of applying
a thermal load (thermal shock) had been adopted to know the importance of this
effect. So, a coupled field method with the same program, had been used to calculate
these values with estimation effect of heat transfer method. The results proved that for
an instant temperature difference the effect of steady-state heat transfer method was
more than the transient method. Also TSIF for low temperature difference, may
exceed the value of MSIF in case of (100 MPa) statical structural applied load without
considering the temperature effects.

to Ovality, it would most likely occur first at the riding rings where Ovality is the
greatest[Idem 1996]. Failure modes that can be associated with high Ovality
include[Idem
1-Prematuremechanicalrefractoryfailure.
2-
1996]:
Overheating and /or failure of carrying mechanism bearings.
3-Shell
4-
cracking.
Weld
cracking.
The kiln Ovality plays an important role in determining refractory life , no
correlation, however, has been developed between refractory wear rate and kiln
Ovality.Cement rotary kiln refractories are worn by the synergistic effect of thermal,
chemical and mechanical stresses. These stresses are complicated and it is quite
difficult to distinguish the wearing causes in actual conditions. In this research only
mechanical stresses caused by Ovalities have been considered.
The graphics data [Tuchiya 1996] (Figure 1) clearly illustrates an increased brick
wear rate with increased Ovality