Journal of Engineering

This paper presents numerical and experimental stress analyses to evaluate the contact and
bending stresses on the teeth of spiral bevel gear drive. Finite Element Method has been adopted as
a numerical technique which accomplished basically by using ANSYS software package. The
experimental stress analysis has been achieved by using a gear tooth model made of Castolite
material which has photoelastic properties. The main goal of this research is detecting the maximum
tooth stresses to avoid the severe areas that caused tooth failure and to increase the working life for
this type of gear drives.

In the 1980s, the French Administration Roads LCPC developed high modulus mixtures (EME) by
using hard binder. This type of mixture presented good resistance to moisture damage and improved
mechanical properties for asphalt mixtures including high modulus, good fatigue behaviour and
excellent resistance to rutting. In Iraq, this type of mixture has not been used yet. The main
objective of this research is to evaluate the performance of high modulus mixtures and comparing
them with the conventional mixture, to achieve this objective, asphalt concrete mixes were prepared
and then tested to evaluate their engineering properties which include moisture damage, resilient
modulus, permanent deformation and fatigue characteristics. These properties have been evaluated
using indirect tensile strength, uniaxial repeated loading and repeated flexural beam tests. EME
mixes were found to have improved fatigue and permanent deformation characteristics, also showed
more resistance to moisture damage than conventional mix by 9.3 percent and the resilient modulus
at temperature 60 oC increased by 63 percent. The general theme viewed from the results of this
study has added to local knowledge the ability to produce more durable asphalt concrete mixtures
with better serviceability using EME mixes.

The planning, designing, construction of excavations and foundations in soft to very soft clay
soils are always difficult. They are problematic soil that caused trouble for the structures built
on them because of the low shear strength, high water content, and high compressibility. This
work investigates the geotechnical behavior of soft clay by using tyre ash material burnt in air.
The investigation contains the following tests: physical tests, chemical tests, consolidation test,
Compaction tests, shear test, California Bearing Ratio test CBR, and model tests. These tests
were done on soil samples prepared from soft clay soil; tyre ash was used in four percentages
(2, 4, 6, and 8%). The results of the tests were; The soil samples which gave the value of plas
ticity test were 2% (25), 4% (25.18), 6% (25.3), and 8% (26.7).The soil samples which gave the
value of specific gravity were 2% (2.65), 4% (2.61), 6% (2.5), and 8% (2.36).The value of
maximum dry density in a compaction test observed with 2% percentage gave the value 15.8
kN/m3, the 4% gave the value 15.4 kN/m3, 6% gave 15.3 kN/m3 and 8%with 15.2
kN/m3.Samples that gave the values of undrained shear strength test were 2% (55 kN/m2), 4%
(76 kN/m2), 6% (109 kN/m2), and 8% (122 kN/m2). The best of them is 8%.
The sample that gave the best value for swelling test was 8%.The best value for compression
index Cc was in 8%.The results of CBR test, were improved in all soil samples. The soil sam
ples which gave the value for CBR were 2% (3.507%), 4% (4.308%), 6% (5.586%), and 8%
(9.569%). The best value was obtained from 8%.

In this work, the nano particles of Na-A zeolite were synthesized by sol –gel method.
The samples were characterized by X-ray diffraction (XRD), X-ray Fluorescence (XRF), Surface
area and pore volume, Atomic Force Microscope (AFM) and Fourier Transform Infrared
Spectroscopy (FTIR). Results show that the nano A zeolite is with average crystal size is 74.77
nm., Si/Al ratio 1.03, BET surface area was 581.211m2/g and the pore volume for NaA was
found equal to 0.355cm3/g.

The aim of this study was to investigate the effect of operating variables on,
the percentage of removed sludge (PSR) obtained during re-refining of 15W-40 Al
Durra spent lubricant by solvent extraction-flocculation treatment method. Binary
solvents were used such as, Heavy Naphtha (H.N.): MEK (N:MEK), H.N. : n-Butanol
(N:n-But), and H.N. : Iso-Butanol (N:Iso:But). The studied variables were mixing
speed (300-900, rpm), mixing time (15-60, min), and operating temperature (25
40,oC). This study showed that the studied operating variables have effects where,
increasing the mixing time up to 45 min for H.N.: MEK, H.N.: n-Butanol and 30 min
for H.N.: Iso-Butanol increased the PSR, after that percentage was decreased;
increasing the mixing speed for all the studied solvents up to 700 rpm increased the
PSR, after that the percentage was decreased, while increasing the operating
temperature decreased the PSR for all the solvents. This study has resulted in
reasonably accurate multivariate process correlation that relates the removed sludge
percentage to the process variables. The determination coefficients (????2) were
significantly high and equal to 0.957, 0.974, and 0.944 for N:MEK, N:n-But, and
N:Iso-Butl respectively. The best operating conditions resulted the maximum PSR
were (30 min, 900 rpm, 30 oC ), (45 min, 700 rpm, 35 oC), and (30 min, 700 rpm, 35
oC ) for N:MEK, N:n-But, and N:Iso-Butanol respectively.

Ball and Plate (B&P) system is a benchmark system in the control engineering field that
has been used to verify many control methods. In this paper the design of a sliding mode
controller has been investigated and verified in real-time via implementation on a real ball and
plate system hardware. The mathematical model has been derived and the necessary parameters
have been measured. The sliding mode controller has been designed based on the obtained
mathematical model. The resulting controller has been implemented using the Arduino Mega
2560 and a ball and plate system built completely from scratch. The Arduino has been
programmed by the Arduino support target for Simulink. Three test signals has been used for
verification purposes, namely: single point stabilizing, circular trajectory tracking, and square
trajectory tracking. The results obtained have shown that sliding mode controller is able to
follow the desired test signals with low error.

In the present research a new test rig has been proposed to be suitable for different cyclic loads
such as cyclic bending, cyclic torsion, proportional and non proportional loads. In this work the
efforts were concentrated on the cyclic bending loads concerning cracked pipes with or without
internal pulsing pressure to study crack propagation in small bore pipes (up to 1'') for transverse
or inclined cracks. The rig simulates the real service conditions under different stresses by means
the least dangerous case will be suggested, so the experiments were considered for copper pipe,
and the results have been tabulated and drawn to demonstrate the crack growth behavior as well
as to justify the outcomes practically, consequently the durability of this new rig has been
confirmed with new concluded facts.

University Campuses, as any lively physical entity, is subject to continuous variation due to
growth, development and change. This reality covers the existing or futuristic additives or addi
tions, consecutively these changes may have a strong sensation of disorientation as a result of for
matic changes in buildings, or in movement paths.
And it epitomized the research problem to "the need for knowledge to clarify the impact of intellec
tual and executive policy in achieving coherence, functional and space organization of the elements of the university urban environment and in the stages of future growth and change," the search tar
geted "to highlight the study of constraction politics on campus Bmqomadtha intellectual and exec
utive , as well as clarify the role of the executive policy in the application of thought, "and formulat
ed the hypothesis search " urban policy affect Bmqomadtha (intellectual and executive) on the pro
cess of organizing and homogeneity of the university urban environment to make them adapted to
future changes, "the University of Kufa it was chosen as the campus to represent the experimental
field of research.