Engineering and Technology Journal

Although many researchers have done many studies on recycled aggregate
concrete, information is very little about the influence of utilizing recycled
aggregate in the production of reactive powder concrete. Experimental
work was executed to investigate the influence of utilizing recycled
concrete as fine aggregate in reactive powder concrete. Five different
mixes were prepared, the first mix, or control mix, was prepared with
natural sand, four additional mixes were prepared with different
percentage of substitution of fine aggregates(20%,40%,60%, and 80%).
The investigation was carried out using compressive strength test, direct
tensile strength test and flexural strength test, and two methods of curing
were used standard curing at 20 °C and steam curing at 90°C. the results
indicated that the strength decreases with increased the percentage of
recycled fine aggregate, and the best percentage was 40% replacement
where the percentages of decrease at this percentage at 28-day steam
curing were 2.46, 6.66, and 2.14 for compressive strength, flexural
strength, and direct tensile strength respectively

In this paper, Artificial Neural Network was adopted to predict the effect
of current, the concentration of aluminum oxide (Al2O3) and graphite
Nanopowders in dielectric fluid for the machining of Carbon steel 304
using Electrical Discharge Machining (EDM). The process variables were
utilized to find their effect on Material Removal Rate (MRR), Surface
Roughness (SR), and Tool Wear Rate (TWR). It was revealed from the
experimental work that the addition of aluminum oxide and graphite
Nanopowders into dielectric fluid maximizing MRR, minimized the SR and
TWR at various variables. Minitab software was used in the design of
experiments. Analysis of the process outputs of EDM indicates that
graphite powder concentration greatly influencing SR also the discharge
current whereas the current and Nanopowders concentration has more
percentage of influence on the TWR and MRR

The material utilized for manufacturing artificial dentures should have
high-grade mechanical properties in order to resist heavy forces inside the
mouth. This study includes investigation of some of the mechanical
properties (wear rate resistance, compression strength, and hardness) of
the specimens prepared by (hand lay-up) method. The wear behavior
experiments were performed on (a pin-on-disk tester) under various
factors 5%, 8%, 11%, 14%, 17% weight fraction of orange peel, (10, 15,
20 N) load applied and (5, 10, 15 minutes) sliding time, and analysis these
experimentally by using the Taguchi’s experimental design (L9) (MINITAB
16). Tests explicated that the specimens (polymethylmethacrylate - 17%
orange peel) composites have the best wear rate resistance, compression
strength and hardness shore D (0.040×10-5 cm3/N.mm, 142 MPa, 86 shore
D) respectively than other specimens (polymethylmethacrylate - 5%, 8%,
11%, 14% wt. orange peel) and these specimens better than the specimens
standard polymethylmethacrylate, which could be attributed to the
homogeneous dispersion of orange peel particles in the
polymethylmethacrylate resin matrix. The results (signal to noise ratio)
showed the factors (17% weight fraction) orange peels, (20 N) load
applied, and (5 min) sliding time gives the best wear rate resistance. The
results of the analysis of variance showed the sliding time (C) is the
essential factor effect on the wear rate resistance followed by (A) weight
fraction of orange peels and (B) load applied were less affected

Improving the essential factors of rotor bearing system are the aim of this study. In
addition to the presence of two ball bearings to support the rotor, two additional
fluid film journal bearings have been used as an external damping sources. The
ANSYS Mechanical APDL 18.0 was used to model rotor bearing system with
existence of two additional fluid film journal bearings. Matlab software has been
used to achieve the analytical solution. The results clearly showed that the maximum
response displacement strongly decreasing and the critical speed has been enhance
by using an external damping source as well as the stability of rotor bearing system
has been improved due to increasing damping of rotor system where the response
displacement decreasing by 99% and critical speed increasing by 0.6% when using
an external damping sources. The position of damping source has an important
effect on the maximum response displacement and the more decreasing value of
response displacement has been achieved when the damping source become as close
as possible to the disk position.

Laser shock peening is a widely common process for materials treatment
and typically used for fatigue strength enhancement especially for metals.
In this paper, its effect on polymeric composite materials studied
experimentally. Unsaturated polyester was used as a matrix in order to
composites preparation and Aluminum powder as fillers. A Hand lay-up
technique has been used for composites making. Composites with three
volume fractions of Aluminum powder were prepared (2.5%, 5%, and
7.5%). Fatigue specimens as a standard and with (1mm) semi-circular
notch are prepared for testing. The fatigue test was performed at room
temperature and stress ratio (R=-1). Laser shock peening with two levels
of energy have been applied (1Joule, and 2Joule). The results showed an
increase in the endurance strength of the notch for 7.5% volume fraction
especially at 1J laser energy by about 26.7056% compared with the untreatment
notched state, which in turn reduced the fatigue stress
concentration by about 21.0508% compared with standard fatigue stress
concentration. On the other hand, the presence of notch effect on
endurance strength was increased after laser treatment of composites with
2.5% volume fraction and the reduced was by about 39.698% at 2J laser
energy.

Manufacturing of building materials with unique properties is one of the
most important key-parameters in the development of construction
engineering and building materials. The development in the nanomaterials
and nanotechnology can be utilized in this field. In this paper, production
of eco-friendly, low water absorption and self-cleaning cement mortar
reinforced with carbon nanotubes and nano-silica with different weight
percentages (0.5%, 1.5%, and 2%) is performed. Results showed
prominent improvement of hardness, compression strength and a decrease
of water absorption and bending resistance in the reinforced cement
mortars. The results show the possibility to control the mechanical
properties of the cement mortars with minimal reinforcing agents provides
the possibility to design these building materials

In this paper, a unique combination among probabilistic roadmap, ant
colony optimization, and third order B-spline curve has been proposed to
solve path-planning problem in complex and very complex environments.
This proposed method can be divided into three stages. First stage is to
construct a random map depending on the environment complexity using
probabilistic roadmap algorithm. This could be done by sampling N nodes
randomly in complex and very complex static environments, then
connecting these nodes together according to some criteria or conditions.
The constructed roadmap contains huge number of possible random paths
that may connect the start and the goal points together. Second stage
includes finding path within the pre-constructed roadmap. Ant colony
optimization is selected to find or

Air temperature (T air) near the land surface is a fundamental descriptor
of physical environmental conditions and one of the most widely used
climatic variables in global change studies. In this study, the researcher
trying to suggest a model for estimating air temperature in summer season
for any region through integrating of Iraqi Agrometeorological network
daily (T air) with the moderate resolution imaging spectroradiometer
(MODIS) land surface temperature (LST), Duration Day Length (DDL)
and Digital Elevation Model (DEM). In this model, using satellite images
for the study area and data of air temperature for four weather stations
located in Babylon governorate from 1- June to 30- September on year
2017 for modeling and accuracy assessment air temperature estimation.
The standard error of this model is 1.72887° C, and the correlation

The inverted pendulum is a standard classical problem in the branch of
control and systems. If a cart is bushed by force then its position and angle
of the pendulum will be changed. Several controllers may employed,
keeping the pendulum arm upright by controlling at the cart location. In
this search paper, the fuzzy-like PID (FPID) controller has been used to
control the inverted pendulum, and the parameters of the controller are
tuned with several evolutionary optimization algorithms like a genetic
algorithm (GA), ant colony optimization (ACO), and social spider
optimization (SSO.) The result of tuned FPID with evolutionary
optimization is compared with conventional PID, and it shows that FPID
with SSO has been given the best result

In this investigation, Zn-Al alloy metal-matrix nano composites that
reinforced via various weight percentages (2%, 4%, 6%, and 8%) of
nanosilica (SiO2) particles were fabricated applying the technique of stir
casting. Behaviors of the corrosion of the unreinforced alloy and
reinforced composites were measured utilizing a potentiostat test in a (3.5
wt.% NaCl) salt solution. The optical microscopy was employed to
investigate the surface microstructure of the composite. Microstructure
analysis manifested that the uniform distributions of the reinforcing
particles in the composites are alike, consisting of a dendritic structure of
the zinc alloy matrix with an excellent reinforcing particles steady
dispersion. The improved results of the corrosion resistance for the metal
matrix composites showed an excellent resistance to corrosion than the
matrix in the (3.5 wt.% NaCl) solution. Raising

In this paper, a numerical investigation has been performed to study the
effect of varying the thermal properties of the paraffin wax on the
performance of a double glazed window doped with it during the summer
climate of Baghdad (33.3 °N, 44.4 °E). Using FORTRAN (f 90)
constructed computer program, finite difference combined with the
enthalpy method was utilized to deal with the conduction with phase
change problems within the wax. Results obtained show that increasing
the density, latent heat, and thickness of the paraffin wax PCM) would
increase the temperature-time lag and reduce the temperature decrement
factor of the double glazed window, and as a result, improve
comparatively the performance of the unit. In contrast, changing the
specific heat capacity of the paraffin wax is not a productive (inefficient)
technique to develop the performance of the unit. Besides, the
recommended thickness of the window (thickness of the PCM) under the
ambient condition of Baghdad should be 20 mm

RS have an important role in the performance of components and
machined structures. The objective of this paper is to study the influence of
cutting speed on RS in workpieces that are formed in orthogonal cutting.
AISI 316L stainless steel since it has been used in many important
industries such as chemical, petrochemical industries, power generation,
electrical engineering, and food and beverage industry. Four cutting
speeds are selected: (44, 56, 71 and 88) m/min. The alloy was machined

Double skin ventilated roof is one of the important passive cooling
techniques to reduce solar heat gain through roofs. In this research, an
experimental study was performed to investigate the thermal behaviour of
a double skin roof model. The model was made of two parallel galvanized
steel plates. Galvanized steel has been used in the roof construction of
industrial buildings and storehouses in Iraq. The effect of inclination angle
(ϴ) from the horizontal and the spacing (S) between the plates was
investigated at different radiation intensities. It is found that using a
double skin roof arrangement with a sufficient air gap (S) can reduce the
heat gain significantly. The higher the inclination angle (ϴ) the higher the
ventilation rate, the lower the heat gain through the roof. In this study,
increasing the air gap from 2 cm to 4 cm reduced the heat gain
significantly but when the gap was further increased to 6 cm, the reduction

This paper presents the forward, inverse, and velocity kinematics analysis
of a 5 DOF robotic arm. The Denavit-Hartenberg (DH) parameters are
used to determination of the forward kinematics while an algebraic
solution is used in the inverse kinematics solution to determine the position
and orientation of the end effector. Jacobian matrix is used to calculate
the velocity kinematics of the robotic arm. The movement of the robotic
arm is accomplished using the microcontroller (Arduino Mega2560),
which controlling on five servomotors of the robotic arm joints and one
servo of the gripper. The position and orientation of the end effector are
calculated using MATLAB software depending on the DH parameters. The
results indicated the shoulder joint is more effect on the velocity of the
robotic arm from the other joints, and the maximum error in the position
of the

The investigation on the efficiency of three organic derivatives was done
as inhibitors for carbon steel using electrochemical methods at four
temperatures (303, 313, 323, and 333 K) and 100 ppm. The results showed
that these prepared compounds gave good efficiencies at experimental
conditions by adsorption process and they act as mixed-type inhibitor, the
data of corrosion were measured and debated. Using SEM, the inhibited
surface of specimens was characterized. In addition, for display the
interaction between these compounds and the metallic surface, the Fourier
transform infrared spectra was used. In addition, the activity of
antibacterial of the inhibitors against some types of bacteria

Conductive polymer films were prepared of polyvinyl alcohol (PVA) with
(0, 2, 4, 6, 8, and 10) wt. % multiwalled carbon nanotubes (MWCNTs) by
electrospinning technique. The morphologies of the synthesized films were
tested by scanning electron microscopy (SEM). Average fiber diameters
gauged statically was (115nm) for (PVA/10 wt. % MWCNT film) while
(170nm) for pure PVA electro spun film. Electrical conductivity (EC) of
Polymeric nanofiber films improve by increasing MWCNT addition
concentration from (3.69 × 10-7 S/ cm) for the pure (PVA) film to (1.24
×10-2 S/cm) for the film with 10 wt. % MWCNT. The maximum stress of
PVA film were increased by adding MWCNTs concentration, the modulus
of elasticity was enhanced from 12.87 MPa for pure PVA to 49.89 MPa for
PVA/8wt% MWCNT

In this research, the diffraction ring patterns scan and single-beam Z-scan
techniques were used to measure the nonlinear refractive index (n2) and
nonlinear absorption coefficient (β). Nano-composite sample, which
consists of zinc oxide nanoparticles (ZnO-NPs), and epoxy resin polymer.
The sample was prepared by the casting method. A second harmonic
generation Nd: YAG laser, which operates at 532 nm and intensity 3183
W/cm2 was used for the two techniques. Z-scan results showed that values
for nonlinear refractive index n2 and nonlinear absorption coefficient β
were obtained of 6.59*10-9 cm2/W and 1.75*10-3 cm/W respectively. While
results for the D-scan technique showed that the number of rings increases
with the increasing of laser power.

Step down DC-DC converters are power electronic circuits, which mainly
used to convert voltage from a level to a lower level. In this paper, a
discontinuous controller is proposed as a control method in order to
control Step-Down DC-DC converters. A Lyapunov stability criterion is
used to mathematically prove the ability of the proposed controller to give
the desired voltage. Simulationsl1 are performedl1 in MATLABl1
software. The simulationl1 resultsl1 are presentedl1 for changesl1 in
referencel1 voltagel1 and inputl1 voltagel1 as well as stepl1 loadl1
variations. The resultsl1 showl1 the goodl1 performancel1 of the
proposedl1 discontinuousl1 controller

Environmentally friend biodiesel fuel from corn oil was tested in singlecylinder
4-stroke diesel engine operated. Three blends of fuels were
prepared from corn oil and diesel fuel viz. 7, 15, and 20 % (designated as
B7, B15, and B20, respectively). Tests were conducted on this engine using
these blends at a constant speed (1500 rpm) and varying loads (0 % to 100
%). The emissions of carbon monoxide, carbon dioxide, unburned
hydrocarbons, nitrogen oxides (NOX) and smoke opacity were measured. In
all engine loads, results showed that the emission of CO, HC, and smoke
emissions were reduced, while that of NOX and CO2 were increased.
Biodiesel blend (B20) showed the highest decrease of the CO and HC and
smoke emissions by 22.13 %, 18.5 %, and 25.8 % respectively. While that
of NOX and CO2 emissions were increased by 22.3 % and 22%,
respectively. It can be recommended as a sound environment friend and
renewable for use in diesel engines

An experimental investigation is carried out to investigate the impact of
the footing shape, when rested on clayey soil under cyclic loading
condition. The model footings used in this study are circular, square and
the area of footings is fixed. Cyclic load test is carried out on the cohesive
soil with three undrained shear strengths (20 kPa, 40 kPa and 70 kPa).
Two depths of foundation embedment (at surface and 5 cm) to know the
effect of the depths of the foundations on the change of settlement and total
vertical stress and two rates of loading (3 mm/sec and 6 mm/sec) are used.
It has been observed that the bearing capacity varies in increasing order
as Solid, Circular and Square. It is found that the cyclic settlement in the
square foundation is less than the circular foundation. The results reveal
that the shape of the footing has a significant effect on its bearing capacity
and the settlement characteristics. The vertical stress reaches a constant