Engineering and Technology Journal

Two-dimensional, supersonic flow field computation with by-pass holes has been
conducted using Euler equation. An algorithm based on finite difference
McCormack's technique is used to solve the subsonic-supersonic flow problem with
and without by-passing. Trials on by-pass locations were also made. Operation
without bypass shows the movement of the normal shock wave upstream which
refers to an off-design operating regime. At a distance of 1.271 m measured from the
cowl lip, the region of normal shock wave was localized near the throat which
approximately represents the on-design perform 0ance condition (cells 8-9). When
the flow is bypassed from the rear passages, the normal shock wave is sucked inside
the flow passage save poor performance. Results show that by-passing provides a
fast reaction to maintain a steady performance which meets the requirements of ondesign
operation. The Mach number variation corresponding to each case is
presented. Results show that the tendency to unity Mach number near the cowl lip
sector can be achieved using by-pass expelled. The influence of by-pass on the total
pressure recovery and relative pressure is also discussed.

Distillation columns are widely used in chemical processes as separation systems in
industries. In order to gain better product quality and lower the energy consumption of the
distillation column, an effective control system is needed to allow the process to be operated
over larger operating ranges. In this study Different control strategies were used to control the
distillate and bottom compositions of a packed distillation column to separate the mixture of
methanol (CH3OH) and water (H2O). The tuning of control parameters were determined for
PI and PID controllers using three different methods; Internal Model Control (IMC), Ziegler-
Nichols (Z.N), and Cohen-Coon (PRC) to find the best values of proportional gain (KC),
integral time (τI) and derivative time (τD). The Internal Model Control (IMC) method gave
better results than that of the other two methods thus it was recommended to be the tuning
method in this work. The low values of ITAE of 61.3 for distillate product composition and
54 for bottom composition were obtained which represent the adaptive neuro-fuzzy inference
system (ANFIS) method and assure the feasibility of this method as a control strategy among
other methods (conventional feedback controllers (PI, PID), artificial neural network (ANN) ,
adaptive fuzzy logic and PID fuzzy logic controllers).

This research is interested to investigate the optimum design procedure for a
finger driving mechanism to have a proper configuration of the finger for its
utilization in hand prosthesis. To get this goal, a Genetic Algorithm (G.A) was
used. Three criteria were selected to find the optimal solution. The most important
of them was the percentage of the grasping stability. This criterion was evaluated as
must type by using Kepner-tregos method. When the optimal solution was found,
this one was modified to facilitate the fabrication of a prototype. The modifications
consist of mostly rounding the parameters and uniforming the rollers dimensions.
Those changes did not affect too much the forces characteristics. The prosthetic
hand prototype was built of hard ABS (Acrylonitrile Butadiene Styrene) plastic
using rapid prototyping. Testing results indicate that the proposed Genetic
Algorithm gives reasonable -quality results in short computation time

Groundwater is considered as an important source of water supply in Iraq, so it is
need replenishing by any way of recharging. The most important way for recharging
the groundwater is by rainwater harvesting. The part of rainfall which losses as surface
runoff can be store during the monsoon in collecting reservoirs (such as ponds or
tanks) and use it when required. This study deals with the way of harvesting rainwater
that falls on the land for the replenishment the groundwater and use it in the dry
seasons.
According to availability of recommended potential for successful artificial
recharge projects, a site was selected in the Jolak basin north of Karkuk city, north of
Iraq. The area is about 400 km2. Since the occurrence of rainfall in the north of Iraq is
mostly limited to about five or six months in a year, so the recharge to ground water
reservoir is restricted to this period only. The surplus rainwater is assumed to be
collected in the several suggested collecting rectangular ponds to catch monsoon rains
(storing a fraction of runoff). This water can then be diverted to the aquifer through
recharge wells (which already exist in the study area) and replenish falling
groundwater table by pumping the stored water. Ponds need to be lined to stop water
from seeping out. Plastic lining has proved to be appropriate mainly because of low
cost and reliability of the material , so it is suggested to be use in the lining of the
ponds. Also the ponds are suggested to be cover during groundwater recharging in
order to stop water from being lost into the air by evaporation. A computer software
known as Groundwater Molding System (GMS) has been used in the present study to
simulate the water conveyance from the collecting ponds to the underground reservoirs
by wells. Results indicated that movement of surface water into the groundwater was
predominantly an effective process. It can be shown also, that collecting ponds were a
key driver of surface water into the subsurface along the study area

The knowledge of statistic characteristics in mechanical properties is important
for designer in order to asses the reliability of the structure. Scatter characteristics
of fracture strength (splitting strength) of porcelain toughened by zirconia and the
effect of sintering temperature were investigated in this study. Many specimens
were tested by Brazillian method to obtain the scatter data of fracture strength. The
probability distribution of fracture strength is evaluated by using Weibull
ddistribution function.
Fracture strength is increased with zirconia content having the highest value
(43MPa) at 10 wt.% and then decreased .The same behavior was for Weibull
modulus, having the highest value (39) for 10 wt.% Zirconia .
Fracture strength and Weibull modulus also affected by sintering temperature, they
increased with the increasing of sintering temperature.

Self-compacting concrete (SCC) is an innovative concrete that does not require
vibration for placing and compaction. It is able to flow under its own weight,
completely filling formwork and achieving full compaction, even in the presence of
congested reinforcement. The effect of external sulfate attack was studied-Es (very
sever exposure SO4>10000ppm) according to ACI 318-11.
The mix design method of SCC used is according to EFNARC 2002, and then
must satisfy the criteria of filling ability, passing ability and segregation resistance.
The experimental program focuses to study two different chemical composition of
sulfate resistance Portland cement with different percentage of silica fume
replacement by weight of cement and W/cm (0.3 and 0.35). The SCC mixes with
cement type 1(C3S= 46.39 and C3S/C2S = 1.78) shows more resistance to Es than
mixes with cement type 2 (C3S= 61.22 and C3S/C2S =4.44). The SCC mixes
containing 10% SF as replacement of cement shows more resistance to external
sulfate attack. The percentage of increase is 17.95% for SCC mixes with type 1
cement and W/cm =0.3 and 17.88% for SCC mixes with type 2 cement and W/cm
=0.3 compared to reference concrete mixes

With the increase of the amount of data and users in the information systems,
the requirement of data integrity is needed to be improved as well, so the work has
become necessary independently. One important element in the information system
is a key of authentication schemes, which is used as a message authentication code
(MAC). One technique to produce a MAC is based on using a hash function and is
referred to as a HMAC.MD5 represents one efficient algorithms for hashing the
data, then, the purpose of implementation and used this algorithm is to give them
some privacy in the application. Where they become independent work accessories
as much as possible, but what is necessary, such as RAM and the pulse generator.
Therefore, we focus on the application of VHDL for implement and computing to
MD5 for data integrity checking method and to ensure that the data of an
information system is in a correct state. The implementation of MD5 algorithm by
using Xilinx-spartan-3A XCS1400AFPGA, with 50 MHz internal clock is helping
for satisfies the above requirements

In many road construction projects, if weak soils exist, stabilization and
improvement of their properties is necessary. The stabilization process aims at
increasing the soil strength and reducing its permeability and compressibility. An
experimental program was undertaken to study the effect of engineering properties
of kaolin clayey soils ((the kaolin was supplied by the General Company of
Geological Survey and Mining which originally obtains from Al-Dewiekhla near
Aukashat district in the west of Iraq)) when blended with lime (L) and Silica Fume
(SF). A series of laboratory experiments have been implemented for varieties of
samples: 2.5%, 5.0%, 7.5% and 10.0% for (Lime) and 2.0%, 4.0% and 6.0%
for(Silica Fume). These experiments are: consistency limits test, specific gravity
test, compaction test, unconfined compression test and California bearing ratio
test. For each test, the optimal quantity of Lime (L) and the optimal percentage of
Lime Silica Fume (LSF) combination were determined. The results revealed that:
the optimal percentage of LSF combination was attained at a (2.5%L+6.0%SF),
which served as control in this study. This optimal percentage: decrease the liquid
limit, plasticity index, specific gravity and maximum dry density; and raise the
optimum moisture content, unconfined compressive strength and California
bearing ratio. These results showed also, that the combination of LSF stabilization
at (2.5% L+6.0% SF) is better than the optimal one which achieved by Lime alone:
2.5%L for plasticity index, 10.0%L for specific gravity, maximum dry density and
optimum moisture content, 5.0%L for unconfined compression stress and
7.5%forCaliforniabearingratio. All of these results indicated that the engineering
properties of clayey soils can be enhanced, by blending Lime and Silica Fume
together.

Anew type of porous clay bricks is proposed , this research studies the
effect of adding industrial wastes admixtures with different percentages on the
thermal and acoustics insulation properties of clay bricks . Different types of
admixtures were used in this work ,including plastic cuttings ,wood saw dust
,palm fiber with ( 5% ,10% ,15% ,20 ) percent of weight of each one . Acoustics
insulation , thermal conductivity ,specific heat capacity ,porosity and variation
of density have been examined for each samples at all percent of admixtures
and comparing with the reference clay bricks samples . Form the obtained test
result show the admixtures effect on the properties of clay bricks , the best
material which can used from this paper is palm fiber to get the best properties
of acoustic insulation , thermal conductivity and density for 20% admixtures
percentage comparing with the standard bricks

This study has been conducted to investigate the effect of welding process
parameter on the mechanical properties and microstructure of aluminum alloy 6061,
using friction stir welding (FSW) and Tungsten inert gas welding (TIG). Different
friction stir welded specimens were produced by employing variable welding speed
from 10 to 40 mm/min, and constant rotation speed at 900 rpm. Different mechanical
tests and microstructure examination were performing to evaluate the joints. The
experimental results indicate that the welding process parameters have significant
effect on mechanical properties of the joints, the best result of the (FSW) weld achieve
at 30 mm/min welding speed which give tensile strength 189 MPa, and 55% joint
efficiency of the ultimate tensile strength of parent metal. Tungsten inert gas welded
(TIG) give tensile strength 124 MPa with 37% efficiency of the ultimate tensile
strength of parent metal. The profile of micro hardness tests is shown variation in the
hardness through the welding zones the lowest value at heat affected zone which is 60
HB and the highest value at the nugget zone which is 80HB, but in the case of
Tungsten inert gas welded (TIG) the micro hardness profile is constant though the
welded zones and the value of the hardness is very low about 43. The microstructure
examinations of the friction stir – welded (FSW) are shown three welded zones, first
fine equated crystalline in the nugget zone, second highly elongated grain with very
small cells in thermo mechanical affected zone and third slightly elongated coarse
grain in heat affected zone. For Tungsten inert gas welding (TIG) the microstructure
contain dendrite structure with black eutectic regions and significant amount of
aluminum and silicon.

In this paper, a study on tuning of fuzzy logic controller (FLC) using genetic
algorithm (GA) for controlling an armature controlled DC motor as an example of
linear plant and for controlling nonlinear plant as another example is performed.
There are different ways in which a FLC can be tuned, like: tuning the scaling
gains, Rule Base (RB), and Data Base (DB) represented by type of membership
functions or parameters of membership functions used. The tuning process in this
paper includes a multi-stage tuning represented by searching the good scaling
gains, RB, and DB then a combination of multi-stage (CMS) tuning methods using
Genetic Algorithm (GA) based on a fitness function that is defined in terms of
performance criterion (Integral of Squared Error ISE). The performances of these
tuning stages are evaluated and a comparison between them has been introduced
using linear and nonlinear plants.

The corrosion in petroleum pipelines was investigated by the studying the corrosion
of carbon steel in crude oil and refined petroleum products which include gasoline,
kerosene, and gas oil. Weight loss method was used in which test specimens of carbon
steel, with a known weights, were immersed in the test media for a total exposure time
of 60 days. The weight loss was measured at an interval of 10 days and the corrosion
rate was determined. The results showed that corrosion rate are highest for gasoline
followed by kerosene, gas oil and crude oil, in a decreasing order. The observed
pattern in the corrosion behavior is consistent with the density and weight percent of
hydrogen in the hydrocarbon products. The corrosion rate increases with decreasing
density and increasing weight percent of hydrogen. Experiments were carried out at
different temperatures (30, 60, 90 and 120
o
C) at a constant partial pressure of CO2
(50psi) in 3.5% NaCl solution. The results indicated that as partial pressure of CO2 and
temperature increase, corrosion rate increases due to due to continuous dissolution of
iron ion and formation of weak carbonic acid. The weak carbonic acid dissociates into
carbonate and hydrogen ion, which increases the cathodic reaction on the metal
surface.The presence of small amount of H2S (0.4 ppm) increases the corrosion rate
significantly.

Minimum fluidization velocity is one of the most important parameters when
characterizing the hydrodynamics of a fluidized bed. Experiment studies on the effects
of bed height and material density on the minimum fluidization velocity for inverse
fluidization beds. Were carried out using a 10 cm diameter cylinder fluidized bed. Two
types of particles were tested polyethylene (PE) and polypropylene (PP) bead, each
with a density of 966.6, 877.3, 896.4, or 846.2 kg/m3, respectively, Results show that
minimum fluidization velocity for tow tested materials was insensitive to bed height
and increased with increasing the material density. The minimum fluidization velocity
was correlated with dimensionless groups and independent parameters with correlation
coefficient is 0.9389.

In this paper an electronic interface circuit for controlling the speed of a small
permanent magnet DC motor with the aid of a personal computer (PC) has been
designed and implemented. The basic operation of the proposed circuit is based on
the pulse width modulation (PWM) using a pulse generator with variable pulse
width to drive the motor circuit. The ON and OFF time periods of the PWM signal
are changed by means of mechanical relays connected to the pulse generator
circuit. These relays are connected at the same time to the parallel port of the PC
via a buffer and a driver. A computer program written in C++ programming
language was used to generate the proper digital sequence needed to drive the
control circuit in three different speed levels. This circuit was thereafter
implemented and tested successfully.

In this paper, the energy dispersion relation has been calculated for certain
configuration of single wall carbon nanotubes (SWNT) with respect to the wave vector
(k). The three types of SWNT are armchair, zigzag, and chiral, so the energy dispersion
relation for them are calculated for different chiral vectors. Taking two chiral vectors for
each type of CNT, so (7, 7), (10, 0) for armchair, for zigzag (7, 0), (10, 0), and (10,5),
(20,5) for chiral