Engineering and Technology Journal

This paper proposes a new multimode wireless receiving system based on Blind
Source Separation (BSS) for Orthogonal Frequency Division Multiplexing (OFDM)
signal (based on Wireless Local Area Network (WLAN)) and the Wideband Code
Division Multiple Access (WCDMA) signal (based on 3G cellular system). The
proposed system applied the Independent Component Analysis (ICA) algorithms
(adopting Fast-ICA and JADE algorithms) for blind estimating of the received
signals. The processes of estimation, detection of the signals and equalization of the
channel effects are done as blind methods at the same time. A performance
comparison of the adopting algorithms had been done and the simulation results show
that the multimode receiving system based on Fast-ICA algorithm had a gain of (7
dB) over JADE algorithm for a (10-4 BER) of 30 users WCDMA blindly signal
detection.

In this work, the effects of the overheating temperature and tilt angle on the
microstructure and hardness of a hypereutectic Al-23%Si alloy were investigated.
Al-23%Si melt was overheated to (760, 790, 820 and 850) ºC and poured onto
slope plate continuously cooled with water circulation underneath, with various tilt
angles (40, 50, 60)º using a constant cooling length (300 mm(. After, the melt
became a semi-solid; the slurry was then filled the mould and completely
solidified. Slope plate samples were reheated to a semi-solid temperature (550)ºC
for (10 min) and then quenched in water.
Microstructural images analysis showed that the grain size and the shape factor
of (β-Si) phase were decreased with increasing of the overheating temperature and
tilt angles, on other hand, the volume fraction of (β-Si) phase was increased. The
results of the reheating route showed that the grain size of (β-Si) phase was slightly
increased after reheating at all overheating temperatures and tilting angles. On
other side, the shape factor was improved, and the volume fraction of (β-Si) phase
was decreased, as compared with slope plate results

There is a general interest in increasing the fatigue life of materials. Shot
peening is the process commonly used in order to increase the fatigue
strength and life of 7075-T651. The effect of a combination of processes,
fatigue-creep interaction and shot peening has not been thoroughly
investigated so far. The aim of the present investigation was whether further
improvements can be achieved by a comb/*ination of the two treatments.
Two level experiments (cumulative fatigue damage programe) were used in
order to determine the optimal set of process. It was found that the
combination of shot peening and fatigue-creep interaction could be applied
successfully in order to increase fatigue life for some specimens. Results of
variable loading test clearly indicate that Miner rule does not give accurate
and reliable predictions on fatigue lives

Differential Thermal Analysis (DTA) and high frequency )HF( coil
measurement were carried out in present work in order to measure the liquidus
temperature of some austenitic and duplex stainless steel samples made by
different steel companies in Sweden. A good agreement between the measured and
thermal calculated values using Thermo-Calc software (Appendix 1) was found.
The liquidus model used 1986 shows a lower value for most of these alloys. When
the nitrogen gas used as an inert gas, the nitrogen content increased in the alloys
because of the increasing of nitrogen solubility at high temperature. On the other
hand, the nitrogen content decreased in the alloys when the argon used as an inert
atmosphere because of the different partial pressure of nitrogen between the liquid
alloy and the atmosphere. This changing has an effect on the microstructure and
liquidus values especially in high nitrogen content alloys

The identification of the self coloring process in anodizing process is integral
color. In this research specimens of pure aluminum (1000) and AA 5056 anodized
by using Alternative Current (A.C) techniques were investigated under standard
conditions and electrolytically colored in sulfuric acid baths solutions at different
operating conditions [Alternative Current density (A.C) (2-3) Amp/dm2, electrolyte
concentration (2-6) Normality, electrolyte temperature (15-25) Co and anodizing
time (20-60) minutes]. The experimental work was designed according to (Box-
Wilson) method by using second order polynomial model between four variables
and thickness of anodic layer for the two types of materials and substituted the
experimental results for anodizing process in proposed model to calculate the
coefficients of the mathematical equations to find an expression for obtaining best
film thickness. The coloring deposition efficiency increases with the increase of
applied electrolytic coloring alternative current and the purity of aluminum.
Under standard electrolytic coloring conditions, the current efficiency for coloring
deposition is low for all examined materials. However, pure aluminum has much
higher coloring deposition efficiency than the alloy. The anodizing alternative
current density affects the electrolytic coloring process to a lesser degree for alloy
than for pure aluminum, indicating the role of the morphology of the oxide film.
The increases of anodizing temperature and porous layer thickness have marginal
effect on electrolytic coloring process. Understanding the effect of alloy types on
electrolytic coloring process will enable us to achieve color uniformity and to
expand color and shade selections

For a better understanding of the performance of earth structures, it is essential
to define and evaluate the variables that determine the erosion and dispersion of
soils. A laboratory study has been carried out to characterize the soil internal
erosion due to the water flow and the effect of fine materials percents on the
erosion and dispersion of sandy soil.
A double hydrometer test, crumb test, slacking test and pinhole erosion test
were conducted to investigate the soil dispersibility characteristics. Sandy soil
samples were collected from a region in Mosul city – North of Iraq, and treated
with different percents of fine materials of clayey soil, these percents were ranged
from (0 – 80 %) of the dry weight of sandy soil.
The results showed that, the addition of fine materials enhanced both the
compaction and dispersibility characteristics of sandy soil. As the fine materials
increases, the soil resistance to internal erosion increased. So, the pinhole erosion
test was the more reliability test to classify the soil according to the dispersibility.

This research was carried out to study the mechanical properties and thermal and
acoustic insulation properties of prepared polymer composite. Petiole date palm fibers
with the length (2-3mm) and with different volume fraction ratio (10, 20, 30 and
40%) were used as filler in preparation of polymer composite.
The research imply study effect of pre- deformation for petiole date palm fiber by
chosen compression loads (0, 2, 4 and 6 MPa) on the mechanical properties as well as
on the thermal and acoustic insulation properties of prepared composites. It was
concluded that the pre-deformation to the fibers improves the thermal and acoustic
insulation properties of prepared composite, as well as an increase in the tensile
strength and hardness values with increasing compression load on the fibers. The
highest values of the tensile strength and hardness reach to (133MPa) and (106)
respectively for the polymer composite filled with 40% volume fraction of petiole
date palm fibers which pre-deformed under compression load equal to 6 MPa.

This paper present a direct kinematics modeling of 5 DOF stationary articulated
robot arm which is used for educational tasks, and presents an adopted modeling
method to represent and simulate the simultaneous positional coordinates for each
joint of the robot while it moving from one target to another, where a Lab Volt R5150
robot arm has been taken as a case study. the Denavite – Hartenberg (D-H) model of
representation is used to model robot links and joints in this paper. It utilizes Matlab
2010a software as the tools for manipulation and testing. The adopted modeling
solution was found to be identical with the physical behaviors

High order step wise functionally graded materials Al2O3-Ti are fabricated. These
materials combine the high fracture toughness of Ti phase and the relatively low density
of Al2O3 and stand for candidate materials for harsh mechanical and thermal
environments. The techniques of powder technology are utilized to fabricate these
materials that composed of five graded layers of Al2O3-Ti phases. Al2O3 increasing
linearly across these layers (0, 25, 50, 75 and 100wt% respectively).
The green specimens are composed of Al2O3-TiH2 layers and the sintered specimens
are composed of graded Al2O3-Ti. Spark Plasma Sintering technique is utilized for
sintering of the graded green specimens. The best sintering conditions is found at 1500°C
for 30 minute of sintering that gives apparent density of 4.25 g/cm3, porosity of 1.28%
and diametric expansion of 1.58%. Optical microscopy shows gradual transition of
phases at the interface of the graded layers.

The goal of the present paper is to design and build electronic protection unit for
detection of failures in alternator of diesel generator because of the many technical
problems and failures or abnormal operating conditions that accompany the work
of the generators when it used as a substitute for electrical energy, especially
in long working hours.
Some of these problems and failures: increasing the temperature of the stator
coils, loss of excitation, over/under frequency, over/under voltage and phase
failure.
When any problem occur the proposal protection unit will be displayed the type
of error or problem on liquid crystal display (LCD) as well as gives us an audio
alarm and also shuts down the generator in critical situations.
The design was adopted mainly on microcontroller PIC16F877A, this design is
characterized by low cost, uncomplicated, very high response and flexible to
change software in case you need to add another failures without changing
hardware if compared with the current protection unit in the original generators.

Sawdust concrete has some shortcomings due to the harmful effects of some
organic soluble components existing in the sawdust which affects setting and
strength of sawdust concrete. Also, volume changes of sawdust as an aggregate due
to variation of moisture content, cause large volume changes in the sawdust
concrete. In this work, sawdust was treated before using as an aggregate for
making sawdust concrete. The treatment included boiling the sawdust in water
containing hydrated lime in order to dissolve all soluble organic components. To
reduce water absorption of sawdust, it was dried and treated with waterproofing
material. Two types of waterproofing materials were used (cutback asphalt and
classic varnish). The properties of sawdust concrete were highly improved using
pretreated sawdust. The increase of compressive strength was up to 50% for
moderate sawdust ratios. Flexural strength is also increased, water absorption and
thermal conductivity were highly reduced, while the basic advantages of sawdust
concrete such as lightness of weight, sawability and nailability were not affected

In this paper, a design and implementation of a digital down converter (DDC)
filter for GSM, CDMA, WCDMA is presented. A powerful system design tool,
Xilinx System Generator is adopted to simplify the design cycle and increase the
productivity. The proposed DDC is composed of three stages of cascaded filters.
The maximum operation speed of the Proposed DDC filter is 100MHz. The
remaining sub-modules of the DDC, such as the FIR filter, is co-designed using
MATLAB FDATool and ModelSim with a tradeoff between the receiving path of
requirements, algorithm and hardware implementation complexity. The system has
been successfully verified using the MATLAB module and ModelSim. The most
important stage in the design is the HDL code generation for implementation phase
and results verification.

This work studies the numerical and experimental bending deflection of 3-point
test of the composite beam made of epoxy reinforced by glass fibers and carbon
fibers at different volume fractions .The results show that the deflection decrease in
nonlinear relationship with increase volume fraction for both glass fibers and carbon
fibers .The maximum difference between the experimental results and the finite
element results difference was (11 %) at load (=20 N) and fibers volume fraction
(Vf= 10 %) for glass fibers reinforcement. Also the results indicated that the
maximum deflection was (1.65mm) when reinforced by glass fibers at (Vf =10 %)
and at load (= 20 N) experimentally, while the maximum value of deflection was
(0.55mm) when reinforced at the same load and fibers volume fraction

Active Queue Management (AQM) applies a suitable control policy upon detecting
congestion in networks. In this paper, a Proportional-Integral (PI) controller based on the
optimization algorithm of MATLAB/Nonlinear Control Design Blockset (NCD) which is
adapted as On-line tuning for controller parameters is applied to AQM for the objective
of congestion avoidance and control in middle nodes. To present the methodology, a
Proportional Integral (PI) controller is verified with the TCP/AQM model as an Active
Queue Management (AQM) in internet routers The analytical results for linearized
TCP/AQM model are presented in MATLAB/Simulink. From the obtained results, a
faster response time as well as the regulation of the output to a constant value by the PI
controller is clearly observed and it is noted that the PI controller based NCD provides
good tracking performance for congestion avoidance in computer networks

The conversion of methane gas to synthesis gas (CO and H2) and then into clean
liquid fuels via Fischer–Tropsch synthesis is investigated in the present work. The
effects of the catalyst type, pretreatment conditions, and process temperature on the
catalysts activity and selectivity are investigated.
The syngas production and Fischer–Tropsch synthesis were carried out in two
catalytic units connected in series. The first one contains a fixed bed reactor of 128
cm3, while the second fixed bed reactor is of 68 cm3. The results of syngas
production over the prepared (Pt/HY) catalyst showed excellent resistance to carbon
deposition and stable performance during 20 h-on-stream at 700oC.
The Fischer–Tropsch synthesis was carried out under different temperatures of 220,
230, 240, 250, 260, and 270oC and constant atmospheric pressure. The results showed
that the catalytic synthesis leads to a wide variety of products such as gasoline, diesel
and waxes. It was concluded that the best operating temperature for all Fischer-
Tropsch synthesis is 240oC, where, this temperature gives the highest hydrocarbons
production for diesel and gasoline.
The results indicate that the Cu-Co/Al2O3 was the most active and selective catalyst
in the Fischer-Tropsch process which gives the excellent production of the desired
products.
In addition, this process shows a great potential for economical production of GTL
fuels in Iraq at low costs