Print ISSN: 1681-6900

Online ISSN: 2412-0758

Issue 10,

Issue 10


An Experimental Study for the Effect of Vertical Forced Vibration on Pool Boiling Heat Transfer Coefficient

Zena K. Kadhim; Ahmed A. Mohamed; Sarah Ali Abed

Engineering and Technology Journal, 2012, Volume 30, Issue 10, Pages 1662-1676

In this research, an experimental study for the effect of forced vibrations on
pool boiling heat transfer coefficient has been made in a glass of chamber
cylindrical shape (75 mm bore and 300 mm length) and an electrical heater inside it
(12 mm diameter and 80 mm length) to heat the distilled water at different values
of heat flux (27.521 kW/m2-53.08 kW/m2) utilized to perform this work. The
experimental study is carried out at a range of frequencies (2-40 Hz) and at a range
of amplitude (1.8-3.5 mm).
The result obtained showed that the pool boiling heat transfer coefficient is
increasing with increasing the vibration frequency within a range of (2-14 Hz),
compared with that heat transfer without frequency. And, the maximum
enhancement ratio is about 250% at 5 Hz and q"=27.521 kW/m2, 231% at 6 Hz and
q"=36.727 kW/m2, 181% at 6 Hz and q"=41.83 kW/m2 and 93% at 8 Hz and
q"=53.08 kW/m2. In general, it is found that the difference in the temperature has
been maintained at the highest value of vibration frequency range of (14-40 Hz),
and the value of heat transfer coefficient is significantly increasing with increasing
the vibration Reynolds number (Rev).
The effect of vibration frequency has improved not only the boiling heat
transfer coefficient, but also led to improve the amount of heat drawn by the
cooling water (condensation) by increasing the amount of falling drops.
The following empirical relations have been obtained between the experimental
heat transfer coefficient with vibration (hv) and some of important parameters, such
as excess temperature (ΔTexsses) in oC, input heat flux (q") in (W/m2), and vibration
frequency (f) in Hz:
hv = 0.246912 × f0.16534 × ΔT-0.92429 × q"1.0727 nd, the second correlation is (hv)
with Reynolds vibration effect (Rev) and input heat flux (q") in
(kW/m2)hv=499.747×Rev0.3576×q"-2.14

Assessing New Product Sustainability Index (NPSI) by Integrating Sustainability Aspects into the Early New Product Design Stages

Abdulamir Bektas Wali; Mahmoud Abbas Mahmoud; Jamal Nasir H. Al Khatib

Engineering and Technology Journal, 2012, Volume 30, Issue 10, Pages 1677-1695

Product design is one of the most important stages in the new product development
process influencing global sustainability. However, the early design strategy offers the
highest impact on sustainability, the need for using sustainable proactive approach in
early design decisions could be the effective tool to achieve sustainability of new
products. This paper presents a necessity of considering the sustainability aspects in
pre-specification stages of new product design process, and introduces a modified
methodology for establishing a single Index termed as New Product Sustainability
Index (NPSI) which enables the designers to carry out a quick analysis of the
alternatives of new product designs and make choices based on various criteria. The
index aggregates (TBL) and R & D aspects of different types of quantitative and
qualitative indicators and information objects from a product manufacturing point of
view, into one single index. The sustainability matrix, aspects and criteria used in
evaluating of (NPSI), is constructed in table form.

Study On the Flexural and Impact Properties of Short Okra Natural Fiber Reinforced Epoxy Matrix Composites

Aseel Mahmood Abdullah; Ahmed Mudhafar Hashim

Engineering and Technology Journal, 2012, Volume 30, Issue 10, Pages 1696-1706

The okra natural fiber reinforced epoxy matrix composites were prepared by
hand-lay-up. The weight fractions of okra fiber are (1, 3, 6, 9, and 12% by weight
wt). The flexural properties and impact resistance of composites were determined
by the flexural and impact tests. The maximum modulus of elasticity is (844.93
MPa) at the weight fraction of (12 % wt) of okra fiber, comparison with (91.25
MPa) for virgin epoxy material. The maximum impact energy is (0.75 J) at the
weight fraction of I(12 % wt) of okra fiber, comparison with (0.05 J) for virgin
epoxy material.

Comparative Study of Temperature Control in a Heat Exchanger Process

Afraa H. Al-Tae; Safa A. Al-Naimi

Engineering and Technology Journal, 2012, Volume 30, Issue 10, Pages 1707-1731

In the present work the dynamic behavior of a plate heat exchanger (PHE)
(single pass counter current consists of 24 plates) studied experimentally and
theoretically to control the system. Different control strategies; conventional
feedback control, classical fuzzy logic control, artificial neural network (NARMAL2)
control and PID fuzzy logic control were implemented to control the outlet
cold water temperature. A step change was carried in the hot water flow rate which
was considered as a manipulated variable. The experimental heat transfer
measurements of the PHE showed that the overall heat transfer coefficient (U) is
related to the hot water flow rate (mh) by a correlation having the form:
U mh
0.7158 =11045
In this work the PHE model was found theoretically as a first order lead and
second order overdamped lag while the experimental PHE represented dynamically
(by PRC method) as a first order with negligible dead time value. A comparison
between the experimental and the theoretical model is carried out and good
agreement is obtained. The performance criteria used for different control modes
are the integral square error (ISE) and integral time-weighted absolute error (ITAE)
where the ITAE gave better performance. As well as the parameters of the step
performance of the system such as overshoot value, settling time and rise time are
used to evaluate the performance of different control strategies. The PID fuzzy
controller gave better control results of temperature rather than PI, PID and
artificial neural network controller since PID fuzzy controller combines the
advantages of a fuzzy logic controller and a PID controller. MATLAB program
version 7.10 was used as a tool of simulation for all the studies mentioned in this
work.

Mining Tutors’ Interesting Areas to Develop Researched Papers Using A Proposed Educational Data Mining System

Reem Jafar Ismail

Engineering and Technology Journal, 2012, Volume 30, Issue 10, Pages 1732-1748

Educational Data Mining (EDM) is the process of converting raw data from
educational systems to useful information that can be used by educational software
developers, students, teachers, parents, and other educational researchers. One of
the difficulties in the educational institutes that face the tutor is how to write a
paper. This work aims to help the tutor to write a researched paper on specific
subject by finding another tutor who is also inter
ested in the same subject. This is done by exploring the tutor database by using
the proposed educational data mining system, the tutor database is arranged in
multidimensional form will include: tutor’s teaching subjects, tutor’s interesting
areas, tutor’s published researches, tutor’s Msc. and Ph.D research subjects. The
proposed system implements SMC and Cosine similarity measures with new
proposed representation of tutor’s database. A clustering K-Means techniques and
associated rule generation is implemented by using WEKA data mining tool. The
results obtained from that work are very useful for tutor and they give a rich
analysis for developing researched papers for different tutors.

Diffusion of Salt Water and Alkaline Solutions in Polyester Reinforced by Glass Fibers

Wafaa Mahdi Salih; Rand Mohamad Ali

Engineering and Technology Journal, 2012, Volume 30, Issue 10, Pages 1749-1756

The solubility and kinetics of moisture transport mechanisms in type of resin and
fibers have been investigated the physical tests group comprised the determination of
diffusion coefficient (D) of (0.3 salt water), (0.5 NaOH), (0.5 KOH). The study has
been oriented to investigate a theme that has a crucial interest in most industrial
applications, also the effect of (Salt water, NaOH, KOH) on the composites. The
composite plate contains two type of fibers, the first type: polyester-woven fiber and
the second type: polyester–(random+woven) fibers. The result shows the solution
would be absorbed in the first type more than that in second type. Because of the
fiber/matrix interface plays the role of a channel for a solution to penetrate into the
composite; this penetration normally starts at cut edges. This type of channels found in
the composites, , while alkaline solutions has effect on the composites. Salt water and
NaOH, in composites are more than their identical in KOH, Since polyester has high
resistance to alkine as. The diffusivity coefficient of saltwater in UP s is larger than
that of NaOH and KOH

Finding the Optimal Solution of Fuzzy Transportation Problems

Aseel Hammed Abed Sadda

Engineering and Technology Journal, 2012, Volume 30, Issue 10, Pages 1757-1765

The paper investigates fuzzy transportations problem with the aid of
trapezoidal fuzzy numbers. For finding the initial solution of this problem we have
preferred the fuzzy least costs method and ranking method, also the optimal
solution by using fuzzy multipliers method has been carried out. A new relevant
numerical example was also included.

Potentiality of Waste Water Reuse in Iraq

Karim Khalaf. EL- Jumaily; Mustafa Wajdi Jalal

Engineering and Technology Journal, 2012, Volume 30, Issue 10, Pages 1766-1782

Reusing of treated wastewater effluent, which is normally discharged to the
environment from municipal waste water treatment plants, is receiving an
increasing attention as a reliable water resource. The volume of this resource may
be worthily taken into consideration in the planning and implementations of water
resources projects.
Currently most of the Middle East countries have developed their own
experience in this field, however, among these countries Iraq has nothing to do in
this field, a case which make one feels sorrowful. Therefore, in this work, such
techniques have been analytically discussed, and handy systems of drip irrigation
methods for using treated waste water in Iraq have been proposed. Moreover, in
this paper, a pioneer research study has been carried out as a leading effort on this
promising field of recycling wastewater usage in Iraq.
For the time being, it has been detected that about 1 million cubic meters in
the city of Baghdad only is disposed every day to Tigris river after getting
secondary treatment, It has been shown that in 2020 the amount of wastewater in
the city of Baghdad may increased to as much as (4388264) m3/day, which (if
treated) may irrigate as much as (43882)hectare of industrial crops, or to be used
for planting a green belt of trees surrounding the whole city of Baghdad, this
could help in damping the dust storms which became a predominant phenomena
in the last few years.
It is also shown that the concept of decentralization sewage treatment plants
and separation of gray water in source may be the most dare steps to be taken by
the authorities to comply with the new era of water reuse management in Iraq.

Influence of Currents Density and Gap Size on Metal Removal Rate and Surface Roughness in Electrochemical Machining (ECM)

Hiba Husien Alwan; Saad kariem Shather

Engineering and Technology Journal, 2012, Volume 30, Issue 10, Pages 1783-1796

Electrochemical machining one of non traditional method which is used to
machine a complex shape such as that uses the chemical reaction associated with
electric current to remove metals. In this study the ECM was used to remove the
metals from the internal hole of the workpiece (medium carbon steel) by immersing it
in electrolyte (250g of NaCl for every litter of H2O) with tool is made of brass.
The,m research focuses on the effect of the change in gap dimensions and the
currents density on the metal removal rate (MRR) and surface roughness of the
workpiece the results obtained show that increasing of gap size between the tool and
the workpiece from (1 to 3mm) leads to increase the surface roughness (46%) and
while the material removal rate (MRR) decreases (16%) at a current density (2.856
Amp/cm2). Also increasing of the current density from (2.4485 to 3.6728 Amp/cm2),
the surface roughness of the workpiece decreases (31%) while the Material Removal
Rate (MRR) increases (93.9%) at a gap size of (1mm).

Optimization of liquid-liquid Extraction Column Using Genetic Algorithms

Ali D. Ali

Engineering and Technology Journal, 2012, Volume 30, Issue 10, Pages 1797-1810

In the present study, liquid-liquid extraction column was optimized using Genetic
Algorithms as a non-conventional optimization technique, which scores over
conventional techniques. Genetic Algorithm (GA) is a stochastic search technique
mimics the principle of natural genetics and natural selection to constitute search and
optimization. Genetic Algorithm is applied to the optimal design of liquid-liquid
extraction column to maximize the extraction rate using the superficial velocities of
raffinate and extract phases, (υx, υy) respectively as design variables using Matlab GA
toolbox. Different Genetic Algorithm strategies were used for optimization and the
design parameters such as Population size, crossover rate and Mutation were studied. It
was found that for constant distribution coefficient, m the convergence is obtained in a
very few generations (51 generations). The effect of distribution coefficient, m was
also studied on the optimization process and found that when increasing the
distribution coefficient the optimum extraction rate increased. The best values for υx
and υy were 0.142 and 0.059 respectively, and the objective function (maximum) was
0.2844187.

Imaging with Hexagonal Segmented Mirror

Fouad N. Hassan; A.T. Mohammed; A. J. Tawfiq

Engineering and Technology Journal, 2012, Volume 30, Issue 10, Pages 1811-1815

Different hexagons configuration aperture models of the optical telescope
mirror is carefully considered in this study. The point spread function and the
modulation transfer function of a reference star using different hexagons
configuration are computed and the quantitative assessment for the results are
described. It has been shown that the height of the point spread function decreases
rapidly when the area of the circular aperture of the optical telescope is 18 times
the area of the individual hexagon to be arrange to fill this aperture. No significant
change has been noticed as the area of the this aperture exceeds 121 times the area
of the individual hexagon.

STATCOM Application on the Iraqi (400kv) Super Grid Network with Power Oscillation Damping(POD) & Proportional Integral (PI) Controller

Raaed Faleh Hassan; Ahmed Wahab Abdul Razzaq

Engineering and Technology Journal, 2012, Volume 30, Issue 10, Pages 1816-1842

Flexible ac transmission system (FACTS) can provide control more than
conventional control and achieve fast control response time, STATCOM is a shunt
FACTS device it is used to voltage control and increase the performance of the system.
In this paper STATCOM is used to improve the voltage magnitude and stability for the
Iraqi (400KV) super grid network byusing MATLAB/SIMULINK. STATCOM is
connected to Iraqi (400kv) super gridnetworkwhich is consisting of twenty four buses,
eleven generators, eleven step up transformers fromeach generator side, twenty step
down transformers from each load side and twenty loads.The loads variation through
the seasons of the year causesdrop voltage on the buses of the network.To return the
voltage to the rated value (400kv) STATCOM is used for this purpose. STATCOM
provides suitable reactive power to the network to compensate the drop voltage on the
buses, in the same time when the STATCOM improves the voltage there are large
oscillations. These oscillations are handled by using power oscillation damping (POD)
and proportional integral (PI) controller with the STATCOM.Each of thepower
oscillation damping (POD) and Proportional integral (PI) controller is connected inside
current regulator of the STATCOM device.The performance of the (POD) and (PI) in
cancelation the oscillations is compared.

Study of Some Optical, Electrical Properties of ZnO Thin Films Deposited by Chemical Spray Pyrolysis Method

Ban Kalid Mohumed

Engineering and Technology Journal, 2012, Volume 30, Issue 10, Pages 228-238

In this research we prepared ZnO thin films by Spray pyrolysis method with
thickness (300nm) on a glass substrates and study its optical and electric properties.
The results of (X-Ray ) diffraction showed that the films have a polycrystalline
structure , The Absorption and The transmission as a function of photon energy for
ZnO films had been studied , The investigated of energy gap of the direct allowed
transitions of ZnO film showed a value of (3.14 eV). The optical Absorption
coefficients have been study as a function of Photon Energy.
See beck measurements revealed that ZnO thin films are n-type.

Influence of Microstructure on Abrasive Wear Resistance of Al-12 wt% Si Alloy

Eman Adnan Anon

Engineering and Technology Journal, 2012, Volume 30, Issue 10, Pages 239-247

Abrasive wear of as-cast Al-12 wt% Si alloy has been slid against SiC emery papers
(grits 120 and 220). The wear rate and wear mechanism as a function of bearing
pressure have been studied. The wear rate increased considerably with increasing the
size of abrasive material. Detailed analysis of worn surface showed the formation of
scratches and removal of debris particles by mechanism depended highly on bearing
pressure and to less extent on emery paper. Increasing the bearing pressure resulted in
the formation of debris without plastic deformation of the subsurface.

Residual Stresses Sreated by Heat Treatment for Carbon Steel and their Effect on Mechanical Properties

Khamaal Muhssan; Mohamad Seed Wheed

Engineering and Technology Journal, 2012, Volume 30, Issue 10, Pages 248-259

This work aims to study the effect of residual stresses created by quenching
processes on the fatigue behavior of low carbon steel .The quenching was achieved
from a temperature of (900 °C) using water or oil as quenching medium.
Quenching from a temperature of (850 °C) in oil was also used to produce dual
phase steel. The specimens were divided into two groups, the first was subjected to
tempering for (1 hr) at (200 °C) after quenching, and the second was without
tempering. The results showed that the specimen which was quenched in water and
tempered has the highest value of fatigue limit (356 MPa), and the specimen which
was quenched in oil from (850 °C) and tempered showed a lower fatigue limit.