Engineering and Technology Journal

IC engines are a major source of noise pollution. Mufflers require specific
design and construction. Considering various noise parameters produced by the
engine, the conventional design does not include much of a parametric noise
analysis or other engine characteristics. In this study, a muffler for internal
combustion engine has been designed and manufactured. The performance
characteristic and the effect on transmission losses are investigated for different
types of orifice plates (circle and Square rectangle, triangle) with different bore
areas and frequency. A good agreement with other works is obtained where the
triangular bore shape orifice with minimum bore area is found to be the most
effective.

Mechanical properties were investigated in base and friction stir linear welds of
7075 aluminum alloy. Welding tools consist of a shoulder with a pin and with-out
pin. This work addresses the effects of tool geometry on tensile stress and shear
strength of butt and lap welds, and comparing with base material. Also, the effects
of process condition on the strength of friction stir processed material are
quantitatively characterized. Compared to the butt case, the friction stir lap linear
welds, with pin, leads to a 20% increase in optimized weld strength with 1000 rpm
of tool revolutions and 200 mm/min of tool speed. The optimizing of operating
conditions primarily leads to a 15% increase in optimized weld shear strength,
with 1000 rpm of tool revolutions and 200 mm/min of tool speed.

In the present research, the diffusion of prepared sample blends (PP/PC)
unfilled-filled with different amounts of carbon black (2 – 7) wt% and at different
temperatures (25oC, 40oC and 55cC) were studied. Absorption test was carried out
in (Gas-Oil and Diesel-Fuel) at different immersion times as: Two Conditions were
used to calculate the diffusion coefficient values. In the first Condition
 
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60
4
2
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KL
 , the diffusion coefficient values ranged from (0.252 to1.619)
cm2/sec for immersed in Gas-Oil and it ranged from (0.321 to 1.783) cm2/sec for
immersed in Diesel-Fuel. In the second Condition 



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
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60
4
2
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 the diffusion
coefficient values ranged (0.37 to 2.649) cm2/sec for immersed in Gas-Oil and it
ranged from (0.562 to 2.635) cm2/sec for immersed in Diesel-Fuel. It was found that
the results obtained by the two equations were approximately the same. Indeed the
blend (PP/PC) filled with (4 wt%) of carbon black has the lowest values of
diffusion coefficient (calculated by the above two equations) in Gas-Oil and Diesel-
Fuel which indicates this sample has better performance than other samples. The
diffusion test also was carried out at different temperatures in order to show the
effect of temperature on diffusion coefficient. It was found that the diffusion
coefficient values increase with increasing temperature. All these samples are
obeyed Fickian behavior and the activation energy (E) increases with increasing
amounts of carbon black (2 – 7) wt%.

The aim of this research is to carryout a design study on a variable geometry
rectangular supersonic air-intake at different flight conditions. The design of the
air-intake at supersonic Mach number according to “on-design” condition
(M  2.0,H 10000m  ), to get a maximum total-pressure recovery, and study the
performance of air-intake at supersonic Mach number according to “off-design”
conditions ( 1.6  2.5  M ). The air-intake consists of convergent-divergent nozzle.
The number of oblique shock waves is induced by the sharp cowl lips at the nozzle
entrance and their reflections may continue along the convergent passage
depending on the free-stream Mach number and nozzle wall turning angle. The
location of the normal shock wave is just downstream the throat, for an “offdesign”
condition, and at nozzle throat, at its “on-design” condition [21]. The flow
is assumed as one-dimensional compressible, and inviscid. The flow properties
were calculated using the analytical method based on the relation of the oblique
shock and normal shock waves. The divergent part was analyzed for different
divergent lengths, to maintain the divergent angle less than value that causes flow
separation and to get the maximum total pressure recovery. The convergent part
was analyzed for different convergent lengths, to maintain the oblique shock and
their reflected terminated before the throat position to get maximum total pressure
recovery, [21].

In recent decades, Remote sensing data becomes one of the basic information
required for mapping and different applications in geomatics. In this research,
different mathematical models in 2D and 3D cases are investigated and comprised
in order to assess the accuracy of these models under different conditions of terrain
topography. Three high resolution satellite QuickBird images of three different
study areas, with respect to their topography have been used in this work. In this
research, the 2D mathematical models which were used, 1st, 2nd order polynomial,
and projective transformation model while, the 3D mathematical models used
were, 1st, 2nd order 3D polynomial, and direct linear transformation model. All
these methods are applied for each study area and evaluated through the Matlab
environment facilities

Multicarrier Code Division Multiple Access (MC-CDMA) is attractive
technique for high speed wireless data transmission; it's a combination of
Orthogonal Frequency Division Multiplexing (OFDM) and Code Division Multiple
Access (CDMA). OFDM employs a number of orthogonal subcarriers, this
increases the symbol duration while the CDMA technique provides high capacity
over other conventional multiple access schemes. In this paper discusses
implementation of base band MC-CDMA system using the FPGA technique, all
modules are designed using VHDL programming language. The electronic
functional performance of designed circuits is tested by simulations using VHDL
programming language on XILINX ISE 9.2i. The proposed model is designed
using (Fast Fourier Transform/ Inverse Fast Fourier Transform) and the spreading
code used is the gold code, the implementation of the proposed model using
Spartan-3A/3AN, XC3S700N-3FGG484 FPGA of Xilinx family

The aim of the research is to study water quality in Al-Mustansiriya university,
which is supplied by water through a4 inch diameter pipe, water collected in a very old
ground tank supplying water to the university departments which have their only tanks.
Samples of water from the main pipe and for each department in the university were
taken for seven months (Jan. 2011 -Jul. 2011) Physical, chemical and bacteriological
tests have been done.
Residual chlorine reduced as the temperature increased during the year .Samples
from Arabic language department show the less residual chlorine content. Turbidity
readings did not apply to the Iraqi and WHO standards because the ground tank
contains large amount of sediments and was not cleaned for a long time , maximum
turbidity reading was 6.8 NTU.
The samples were analyzed also to find the chemical properties such as heavy
metals (Fe, Cu, Pb, Zn) and other parameters of water (TDS, CL, Na, S.S, pH, Mn, Ca)
.Iron was the heavy metal which was found in large concentrations that exceeded the
Iraqi and WHO standards because of the corrosion inside the ground tank, maximum
iron reading was 8.4 mg/l. The percent of samples exceeding the standard limits for
sodium, sulphate, chloride, hardness 55, 9.04, 6.19, and 5.71 % respectively.
Bacteriological examinations of water (total coli form, E coli, and total plate count)
show good results although some bacteria were detected but still within the allowable
limits, this is attributed to the present of residual chlorine and the continuous feeding
of water supply due to high consumption of water.

In this paper, it is demonstrated, by means of simulations, the practical
feasibility of an interference filter, implemented from a stack of high and low index
birefringent thin films that can be used as transmission filter. Simulations were
carried out with a software toolbox package implemented as Matlab™ m-files. The
simulation is done by using the following linear material (AgB, ZnSe, KF2, GaAs,
BaF2, TiO2) as coating material with single FBR (fabry perot resonator) structure ,
and KB7 glass as substrate material. Result show that difference between the
values of refractive index of multi layer stack has great influence on the
transmittance value, the largest possible value is the best choice for obtaining
nearly 100% transmittance for the designed wavelength taken and this clearly
observed in the simulation figures. In addition, Number of antireflection layer (N)
effect clearly on the result, the design parameter that take GaAs as high refractive
index material and BaF2 as low index material with N=4 represent good approach
to the desired value for the simulated filter that’s used in (DWDM) .

This paper presents an application of highbrid controller of a Separately Exited
DC Motor (SEDM) using PSO-FL techniques. The controller is designed
depending on fuzzy logic rules are such that the systems are fundamentally robust.
These rules have capability learning, can learn and tune rapidly, even if the motor
parameters are varied. But, adapting fuzzy controller parameters is very complex
and depends on operator experience. Therefore a Particle Swarm Optimization
technique was adapted for obtaining the centers and the width of triangle inputs
membership functions. The FL method is represented too. The complete
mathematical model and simulation of a separately excited dc motor is represented
using MATLAB10a/SIMULINK. The simulation results demonstrate that the
proposed PSO-FL speed controller realizes a good dynamic behavior of the SEDM
with very good speed tracking

Mushroom is one of agricultural products that are in increasing demand several
folds in recent years so, mushroom cultivation represents important income source
for farmers and countries. This paper proposed a real time system used to monitor
and control environmental parameters for mushroom cultivation. Modern module
SH-1000-DTH used as sensing system to measuring environmental parameters
(Temperature, Relative Humidity, and CO2 concentration). Visual basic language
was used to design and implement a control program responsible for processing
data from sensing system and makes a decision to operate one of the mend
environment system devices according to the program stored database. The control
program was designed to make the system work either automatically or manually
to give the user more flexibility in his work and also designed in away makes
dealing with it easy and simple. Results obtained when this system tested show
increasing in production about 46% and increasing in product quality when
compared with the traditional production without using this system.

Golay sequences have some properties make it distinctive in the applications
and results. However, for this distinction must select the code sequences carefully
and accurately. Therefore, to satisfy these requirements, a creation algorithm must
be easy, accurate and powerful. In this paper, an FPGA based, design and
implementation of Golay complementary code sequence(GCCS) creation and then
made autocorrelation between their pair codes to verify properties. The process
time for proposed algorithm is less than that for all possible algorithm by (1/4 to
1/1024 for 4-bit to 16 bits respectively). Thus, the Search can be regarded as
pioneers of the research application of this technique to the subject and got good
results. The Implementation was based on 8-bit pair code and made by Xilinxspartan-
3A XC3S700AFPGA, with 50 MHz internal clock.

The fatigue life of ductile metals is controlled mainly by the propagation life
of a short surface crack; to clarify the growth behavior of short cracks is crucial factor
to the safe design of smooth surface members. However, little has been reported on
the growth behavior of short surface cracks in thermal-chemical treated duralumin. In
the present study, stress-controlled fatigue tests (under rotating bending load) for 70
hours artificial aged duralumin 7075-T6 without chemical treatment case (1) and with
chemical treatment case (2). The growth behavior of short cracks was monitored by a
plastic replication technique and the surface damage (short crack propagation) during
cyclic stressing was observed by optical microscopy. The physical background of
fatigue damage for case (1) and case (2) was discussed from the viewpoints of the
initiation and growth behavior of short cracks

The present paper describes fuzzy logic simulation of an experimental study on the
behavior of hot corrosion in molten salt (Na2SO4) of steel-T21 coated by simultaneous
yttrium-doped aluminizing-siliconizingprocess . Diffusion coating was carried out at
1050oC for 6 hr under Aratmosphere . The weight change measurements made on the
coated steel during the cyclic tests are used to determine kinetics of hot corrosion at
temperature range (800-1000oC) for 100 hr at 5 hrcycle .X-ray diffraction and optical
microscope are used to characterize the oxide phases where the oxide phases that formed
on coated system are SiO2 and Al2O3 .The parabolic rate constants (Kp) calculated show
that the corrosion rate is minimum at 800oC compared to other temperatures. The
experimental results, the fuzzy logic model, and the statistical results showed good
correlations.The fuzzy logicmodels are developed using Matlab toolbox functions.

In this paper, a stainless steel 316 was selected for this study and tested to obtain
its chemical composition, mechanical properties and stress relieving. Then, two
plates (55*55*1) mm were first joined by spot welding and later tested by X-Ray
diffraction (XRD) machine to measure the tensile residual stresses formed due to
thermal effect. In order to remove the tensile residual stresses, a shot peening
process for these spot welded plates was made to create the compressive residual
stresses which will improve the life of spot welded part during the service. The
results of the x-ray diffraction tests exhibited that only compressive residual
stresses formed in the shot peened spot welded plates

Today, an electric consumption on the cooling are increased and the sources of
classical energy in words and in our country are decreased, in additional, the heat
emission phenomena and desert climate, making us to research about solar energy
which available in our country. Single effect cooling system is chosen in this work
to applied the solar energy since, the temperature required to working it is not high,
and there is a possibility to use solar energy under the conditions OF Erbil city. The
temperature ranges re for heating water of generation system are determined and
COP variation with condensation temperature are studied by using the diagrams.
Solar receiver area calculated by using (F-chart ) method .The working are
simulated for summer months by using TRNSYS program's which is dependent on
weather data . Average heating load for each month are calculated , also the
average radiation daily and cooling load for summer months are calculated .The
results indicated that, the optimum area was equal to (160 m2) which satisfied the
maximum value of P*F to produce cooling power 50 kW and COP = 80% . The
simulation was by TRNSYS program which predicted the performance of flat plate
solar recovers through the Summer months