Al-Qadisiyah Journal for Engineering Sciences

This research studied the mechanical properties of particulates composite
materials made from natural fillers (eggshell and sawdust) reinforced epoxy resin. The
composite specimens were prepared by hand lay-up technique with one volume fraction
Vf, and different particle size of fillers.
Modulus of elasticity, tensile strength, percentage of elongation and hardness were
measured for each type of composite. The tensile tests results had shown an incremental
increase with size of particles decreasing also hardness results had shown an incremental
increase with smaller particle size.
This work institutes a good substitution for synthetics fillers avoiding their highly cost and
their toxicity, at the same time reducing of the environmental pollution

The stress of the helical spring changes with several parameter are studied
using (solidworks2014) program. The stress effect is by coil diameter (D) and the shape of
section of the helical spring wire (circular ,rectangular and square) for the same diameter,
where the stress on the helical spring wire increases by increasing the coil diameter (D),
also the stress on the helical spring wire affect by changing the shape of the spring wire
section .

The stress of the helical spring changes with several parameter are studied
using (solidworks2014) program. The stress effect is by coil diameter (D) and the shape of
section of the helical spring wire (circular ,rectangular and square) for the same diameter,
where the stress on the helical spring wire increases by increasing the coil diameter (D),
also the stress on the helical spring wire affect by changing the shape of the spring wire
section .

The swarm techniques are used widly to enhance the response of the control
system, but there are many drawbacks appear when these techniques are used to select
the initial solution for the problem and then will referect on the overall convergence. This
paper try to solve this problem by modify the initial solution of particale swarm techniques
based on fast genetic algorithm, the modified PSO make good free searching in
candidate solutions to get optimum suggesions, which leads the algorithm towards the
global optimum searching over wid range. The proposed controller named PSO-FGA-PID
controller and two experiments are tested by this controller to check the proposed work,
first one the linear time invariant system is taken and the second one is to control on the
speed of the DC motor.

This study deals with experimental studying of the influence of an adjacent
surcharge loads on pile\'s behavior in both horizontal and sloping ground surface. A
number of laboratory tests were performed on instrumented aluminum pipe piles of 25 mm
outer diameter embedded in sandy soil subjected to surcharge load. The study took into
consideration the effect of surcharge intensity, sloping ground and soil\'s relative density on
lateral deformation of piles in terms of displacement and bending moment. The study was
performed on different sloping ground [vertical to horizontal (V:H)] such as, \"1V:3H\",
\"1V:2.5H\", \"1V:2H\" and \"1V:1.5H\", in addition to horizontal ground. Three different relative
densities of sand (29% , 50% and 75%) were adopted in this study. The results showed
that the increasing in the surcharge loads increases lateral displacement and bending
moments of piles in horizontal and sloping ground surface. It was also calculated that the
bending moments and displacement of piles increase with increasing sloping ground and
decreasing relative density of soil.

The ultrasonic peening technique (UP) is one of the innovative and hopeful
methods for fatigue life enhancement and upgrading of welded structures and
components. The fatigue testing of sheet specimens for 6061-T6 aluminum alloy,
demonstrated that the UP is an effective change treatment to mechanical properties as
judged against unpeened specimens. S-N curve and the fatigue fracture mechanism were
scrutinized in detail. The most important results revealed the fatigue life of specimens
improved due to the surface hardening. Residual compressive stresses were created by
UP and increased the fatigue life and strength. This paper scrutinized the potential use of
ultrasonic waves on the surface of 6061-T6 aluminum alloy. This can be exhibited as a
factor of safety due to ultrasonic, reach to 1.42 when estimate the number of cycles
fatigue based on amount of applied stress at 0.3 u

The Bending process is the critical operation in the sheet forming, there are
large parameters influence on operation. Spring back is considering large influential
indication to specify the quality of product parts. The basic parameters which are takes to
study in this paper are: speed of punch, time of hold and thickness of plate. Experiment
use L16 array with four levels for every parameters using V-bending die with 900
, with
different thickness of (0.5,1,1.5,2) mm ,hold time (0,5,10,15) min and punch
speed(10,20,50,100)mm/min, for (1050) Al –alloy having employed as the work pieces.
Spring back value prediction use Artificial Neural Network with conventional configuration.
The results show that the thickness of plate is the large influential parameter effect in
spring back by 77.29%, then punch speed by 10.51% and hold time by 3.36%. The predict
result using Artificial Neural Network shown a best accuracy with (99.35%) in spring back
compared to the measured valu

The operation analysis of isolated signalized intersection provides valuable and
important information about the performance of transportation system in the city. The
signalized intersections are major elements and critical points within the city transportation
network; therefore accurate detailed information and data about the capacity and
operation performance of the signalized intersections is very important and more
significant to evaluate and improve the capacity of the transportation system and network
of the city. Highway Capacity Manual (HCM) Model is widely used for operation analysis of
the isolated signalized intersections in Iraq through number of traffic analysis software
tools which uses the HCM delay model. The most popular and widely used among traffic
analysis software tools are; HCS 2010, SIDRA 5.1 and TRANSYT-7F Release 11. The
objective of this study is a comparison between these three traffic analysis software tools
based on evaluation of the quality of their operation analysis and optimization capabilities
of isolated signalized intersections in order to be a good guide for the traffic engineers to
decide which of these tools provide better results in evaluating the quality of isolated
signalized intersections operation performance and optimizing intersection parameters. To
achieve this objective, Bukhari signalized intersection in Kalar City was selected and the
required data for the study purposes were collected. Based on results of this study SIDRA
5.1 is the most effective and the richest operation analysis and optimization software
among the three selected computer traffic analysis software tools; HCS2010, SIDRA 5.1
and TRANSYT-7F Release 11

In this work, the porous Magnesium alloy (AZ91 ) was prepared by Space
holder technique to deposit carbon nanotubes, Novalac powder was used as space
holding and fugitive materials with different particle size (≥20 µm, ≥500 µm) and amount
(50, 52, 54, 56, 58, 60%wt.). Impact of Novalac powder (particle size and additive percent)
on density and porosity of porous AZ91 alloy was studied. Fine Novalac powder (≥20 µm)
not recommended in the porous AZ91 alloy preparation, concurrently coarse Novalac
powder (≥500 µm) was suitable for that purpose. It was found that the density of AZ91
alloy decreased with increasing Novalac concentration. Carbon nanotubes were deposited
on the porous AZ91 alloy by catalytic chemical vapor deposition whereas NiSO4.6H2O
used as catalyst, acetylene gas as a carbon source and argon gas as a carrier gas with
flow rate percent 1:1, at 575°C process temperature for 30 min. Multiwall carbon
nanotubes were obtained and characterized by X-ray diffraction and scanning electron
microscopy techniques. The average diameter of the multi wall carbon nanotubes was (46
nm). Although the porosity percent of AZ91 alloy was not majorly effect proportionally by
the increasing of an additive Novalac percent, the yield (quantity) of Multiwall carbon
nanotubes was enhancing due to increase the porous AZ91 alloy surface area

This paper presents an experimental study to investigate the effect of hybrid
strength concrete (two types of concrete, 25 MPa and 70 MPa) on the behavior of oneway hollow core concrete slab ordinary reinforced with steel rebars. The hybrid HCSs
showed an enhancement in shear strength capacity, cracking load and ductility as
compared with to HCS with normal strength concrete (25 MPa). The increase in shear
strength capacity and cracking load were about (16%) and (29%) respectively higher than
normal strength hollow core slab. Also, from experimental results, the crack width of hybrid
HCS was narrower than that for normal strength slab at all stages of loading. At service
load stage, the width of crack was narrower than normal strength slab by about (10-31%).
The failure mode still brittle diagonal shear failure.

This paper represents a numerical study of a triple-stage series flow absorption cycle
operating with LiBr-H2O pair. A computational model is implemented using Engineering Equation
Solver (EES) software. This model includes equations of mass, species and energy conservation. The
analysis is used to simulate a triple stage absorption chiller utilization for an air conditioning
applications with a nominal capacity of 300kW manufactured by Thermax company. This chiller is
indirect fired type which uses steam from boiler of the HPG as heat source. The variations of
performance parameters with different ranges of operation conditions have been calculated. The
operating parameters are selected as follows: the HPG, MPG and LPG temperatures: THPG= 150-
230°C, TMPG= 100-130°C and TLPG= 60-95°C, respectively, LPC temperature TLPC= 28-37°C,
evaporator temperature Tevap = 5-14°C; flow rate of refrigerant mr= 1 kg/s; four values of heat
exchangers effectiveness 0.4, 0.5, 0.6 and 0.65. In addition, the comparison between the present
study and other study obtained in literature review has been done. The analysis revealed that
maximum COP is found as a function of both MPG and LPG temperatures. The results outline that the
COP increases with an increase in the evaporator and generators temperature but decreases with
condenser temperature.