Iraqi journal of mechanical and material engineering

Honeycomb sandwich panel dies are manufactured with different core shapes (hexagonal,
circular and square), each shape have two types of facing, one of aluminum facing AA3003
with different thicknesses(0.5mm, 0.9mm &2mm) and the other of composite facing (Eglass+epoxy resin) with(2-layers and 3-layers). Three point bending test is used to investigate
the strength of these honeycombs. The results shown that the square honeycomb\'s core shape
have the highest load from the other core shapes and the hexagonal have the lowest value and
this value increased by increasing the facing thickness, and the aluminum skin facing have
higher load than the composite skin facing. The strength to weight ratio was calculated and
its conclusion observed that the square honeycomb core shape have the maximum ratio and
the circular honeycomb core shape have the minimum ratio. ANSYS software was used to
analyze the honeycomb structure by madea model in APDL-ANSYS program in static and
natural frequency tests using solid and shell elements and MPC algorithm. Results shown
that there are the variations in deflection by percentage of error 27%. The dynamic test
observed that the changing of skin facing thickness effect in the natural frequencies by (3%-
30%) and the changing of the core configurations by (19.7%-38.8%), and by changing the
facing material the natural frequencies effected by (10.6%-37.3%).

The daily time series (stochastic) of the inflow discharge of (Al-Hilla River) at
Babylon was analyzed as a time series. The data used for the analysis was the daily series
during (2004-2014). The series was tested for non-homogeneity and found to be
nonhomogeneous. A significant positive jump was observed at 2009. This non-homogeneity
was removed, the homogeneous series was then normalized transformation. The periodic
component of the series was fitted using harmonic analyses, and removed from the series to
obtain the dependent stochastic component. This component was then modeled using first
order autoregressive model (Markovian chain). The above analysis was conducted using the
data for the period (2004-2012), the remaining two-years (2013-2014) of the observed data
was left for the verification of the model. The observed model was used to generate future
series. Those series were compared with the observed series using t-test. The comparison
indicates the capability of the model to produce acceptable future data

An experimental study has been done on heat pipe 1000mm length and 25.4mm diameter.
Evaporator section is formed by adopting a coil heater over 240mm from one side of heat
pipe length. The condenser section is formed by adopting a water jacket over 300mm from
the other end of heat pipe length. The working fluids used is R-134a. The used wick
structure is of square meshes of (Bronze150*150, Bronze200*200 and Copper145*145).
The wick structure is formed by turning the square mesh layer six times to form an internal
circumference for heat pipe inner diameter. The supplied power over evaporator (20, 30, 40
and 60)W. Thermal conductivity of Copper is 401W/m.Co
and Bronze is 51.2 W/m.oC . It is
found that the thermal conductivity has no effect on the heat pipe performance. But mesh
screen size affected the performance the heat pipe and increases the temperature along the
heat pipe.

This paper present the design and sizing of a small-scale solar photovoltaic powered
reverse osmosis purification system that provides drinking water to domestic or small group
in a remote area in Babil Governorate in south Iraq. The aim of this study is to estimate
an optimum PV system to power the RO that produces 20 l/h (0.35 M3 /day ) at constant
daily load profile. The system designed based on brackish waters at a (Total dissolve solid
(TDS) value of 1500-2000 mg/L) from well in mention area, The PV and solar source
simulated by TRANSYS16 Software to evaluate various PV-RO system. The results
indicated requires energy of approximately 216.5 Wp with about 38 hours battery storage
that can operate the RO unit continually after the sunset . The RO systems powered by PV
panels have many advantages, such as lowest operation cost , simple operation ,
environmentally friendly , easy installation and maintenance, high reliability and
suitability for brackish water.

This research studied the properties of orange and pomegranate reinforced
unsaturated polyester with different powder weight fraction Wf. The orange and
pomegranate powders were added to unsaturated polyester at weight fraction (0,4 ,8 & 11
wt%) with grain size (53µm). The composite specimens were prepared by hand lay-up
technique and cutting according to (ASTM) for wear test, hardness test to obtain of the
composite specimens. The results show that the wear rate for all tested specimens increases
with increase of time of applied load and the wear rate decreases with increasing weight
fraction of particles. Also the best value of properties was obtained for composite materials
reinforced with pomegranate peel at (=11wt%) than composite materials reinforced with
orange peel at this value

This paper presents a numerical study of the effect nanofluids on the erosion corrosion
in the pipes by using coolant fluids. One type of nanoparticles used in this paper cupper
(Cu) and the base fluid (distilled water) as well as the nanoparticles size used are ranging
from (20 – 50 nm). The concentrations of nanofluid used are ranging from (1 – 3 vol %).
The results indicated that property of nanoparticles and their effects on the behavior of the
erosion and corrosion due to the cavitation phenomenon, which causes pipe wall erosion.
This study reveal the effect of the nanoparticles concentration on the flow phenomenon.
Furthermore, the type and size nanoparticles play an important role in the nanofluid flow,
thermall properties and erosion – corrosion behavior. The obtained results indicated that the
contribution of the temperature enhancement and the velocity of nanofluids on the radiator
shape, design and materials. Results showed the critical pressure distribution along the flow
field and predictions on effect of temperature during the erosion – corrosion process.
Moreover the results indicated the effect of velocity, temperature and thermo physical
properties on on the erosion corrosion in the pipe. Two the flow condition used in this study
laminar and turbulent

Electrical contact material are used in variety of application such as electrical switches
,contactors, circuit breakers, voltage regulators .In this paper copper with different weight
percentage of α-alumina composite are prepared by using powder metallurgy technique.
Disk samples of 14mm and 10mm in diameter and 5mm thickness. 5, 10, 15, 20, 30 weight
percentage of α-alumina have been prepared. Tests including microstructure analyses by
scanning electron microscope and optical microscope, electrical resistance, hardness, and
dry sliding wear had been carried out. It’s clear that the hardness and electrical resistance
increase with increasing additive percentage while wear rate decrease with increasing
additive percentage until 15% α-alumina where the wear rate increases .

In this paper NiTi shape memory alloy has prepared from elemental Nickel and Titanium
powders by powder metallurgy Technique, the is 620 MPa compacting pressure , 850 ˚C
temperature and10-3 torr vacuum atmosphere. The Porosity and density before and after
sintering have been calculated. X-ray diffraction analysis showed that Nickel and Titanium
are completely transformed into NiTi and Ni3Ti phase. Poly Methyl Methane Acrylate and
Poly Methyl Methane Acrylate / Hydroxy apatite coating are applied to the surface of the
alloy. Optical microscopy technique is used to characterize the surface of each sample. The
corrosion rate has been studied in vitro by using electrochemical technique by a
potentiostate in Hank’s Solution, Artificial saliva and 0.9% NaCl solution at 37 ºC. Atomic
Absorption Spectroscopy technique is used to detect the Ni ion release from the alloy in
0.9% NaCl solution. The corrosion test results shows that the corrosion rate after Poly
Methyl Methane Acrylate / Hydroxyapatite coating decreased from 12.14 mpy for bare
sample into 0.132 mpy in 0.9% NaCl solution , from 4.94 mpy into 0.39 mpy Artificial
saliva and from 12.66 mpy into 0.217 mpy in Hank Solution. The Ni release test shows that
the amount of releasing Ni ion decreased into undetectable amount after coating with Poly
Methyl Methane Acrylate and Poly Methyl Methane Acrylate / Hydroxyapatite.

The parameters affecting on bead geometry of the dissimilar welding between stainless
steel (AISI-304) and Low carbon steel (ASTM A516 Grade 70) using (Gas Metal Arc
Welding-GMAW) technique were studied in this paper. A multi-response optimization
approach to determine the optimal process parameters in (GMAW) was used. Three process
parameters were used in the experiments: welding current, welding speed and wire diameter,
in three levels for obtaining the responses on bead width, reinforcement and penetration of
the weldments. Taguchi (L9) orthogonal array was used to gather information regarding the
welding process with less number of the experimental runs. A multi criteria decision making
method (TOPSIS) passive was applied in the present study to approve a significant Taguchi
approach in solving multi response optimization problem. In order to consider experimental
uncertainty, the responses are expressed in linguistic terms rather than crisp values. In
additional the (ANOVA) test was passive also applied to identify most the significant
factors. The results of (ANOVA) showed that optimum bead geometry can be reached by a
control on the parameters mentioned above. Also it was found that the welding current
factor contributed the highest percentage (88.14%) to the factor effects, followed by (wire
diameter) which equal (8.92%) and (welding speed) which equal (2.94%). Confirmation
experiments showed that developed models are accurate

In this research, nano powder of zinc oxide was added to a mixture of soil ,urea
powder and water at different weight percentages in order to study the effect of nano
additives. X-ray diffraction and particle size analysis has been studied. An addition
examination of measuring the pH of the soil and temperature to mixture with nanoscale
powder. The results shows that the powder of zinc oxide nanoparticles was granular size (80
nm) and his installation of hexagonal crystal, and adding the powder nanoscale reduced
acidity and maintained a constant temperature of soil and reduce the amount of urea
required temperature therefore added reduce the harmful effect of urea on the constructions

This article presents an experimental study on improvement of heat transfer in car
radiator by using copper oxide, titanium oxide, Ethylene glycol and distilled water
nanofluids. The concentrations of nanofluid used are ranging from (0.5 –5 vol %). Two
types of nanoparticles used in this paper copper oxide (CuO (30nm)) and titanium oxide
(TiO2 (50nm)) as well as the base fluid (Ethylene glycol and distilled water). The effects of
different parameters such as Reynolds number, nanofluid inlet temperature, concentration
and type of nanoparticle on heat transfer coefficient of the flow are studied. The obtained
results indicated that the improvement in heat transfer for the nanofluid (CuO(30nm) + EG
+ Dw) was greater than nanofluid (TiO2 (50nm) + EG + Dw) due to nanoparticles size and
thermal conductivity of the copper oxide. The results indicated that there is an increase in
heat transfer when the volume concentration of nanoparticles are increased with range (0.5
vol % to 5 vol %). About 55% heat transfer improvement was achieved with addition of 5
vol % nanoparticles. Moreover overall heat transfer based on air side increased up 45 %
with addition of 5vol % volume fraction nano particles of copper oxide and titanium oxide
than the base fluid (EG +Dw). In addition the results indicated that using nanofluid as
working fluid leads to higher heat transfer performance which is promoted the car engine
performance and would reduce fuel consumption. Moreover, thermal conductivity for the
nanofluids (CuO + EG +Dw) was greater than nanofluids (TiO2+ EG + Dw) due to
nanoparticles size and thermal conductivity for the copper oxide. The type and size
nanoparticles play an important role in improvement of heat transfer rate. Results show that
heat transfer coefficient increased with increasing of nanofluid inlet temperature,
concentration of nanoparticles and Reynolds number. The results indicated that the
improvement in heat transfer for the nanofluid (CuO (30nm) + Dw+EG) and (TiO2 (50nm)
+ Dw+EG) of 12.4%, 9.52% at Ф = 5vol% and T=70 o
C respectively compared with base
fluid..

In an experimental analysis study, a blend of burnishing parameters was varied to obtain
their optimum values to produce the finest surface integrity in plane surface burnishing
process. The physical depth of the micro hardened surface layer was also evaluated at the
obtained optimum values of the parameters. The analysis was undertaken on ball burnished
plane surface, mild carbon steel M1044, using a milling machine and a purpose designed
and manufactured burnishing tool. The effects of burnishing feed and force on both surface
smoothness and hardness together and on the depth of the hardened surface layer of the
work pieces material were observed and investigated. The results indicated that plane
burnished surface finish and hardness improvements of around (89 %) and (70 %)
respectively were obtainable at the optimum values of the mentioned parameters. Around 35
µm physical depth of the hardened surface layer was the result at the obtained optimum
burnishing force and feed values of about 7.8Kgf and 107 mm/min respectively