Journal of Engineering

The adsorption of copper ions onto produced activated carbon from banana peels (with particle
size 250 µm) in a single component system with applying magnetic field has been studied using
fixed bed adsorber. The fixed bed breakthrough curves for the copper ions were investigated.
The adsorption capacity for Cu (II) was investigated. It was found that 1) the exposure distance
(E.D) and strength of magnetic field (B), affected the degree of adsorption; and 2) experiments
showed that removal of Cu ions and accumulative adsorption capacity of adsorbent increase as
the exposure distance and strength of magnetic field increase.

Experimental and numerical studies have been conducted for the effect of injected air bubbles on
the heat transfer coefficient through the water flow in a vertical pipe under the influence of uniform
heat flux. The investigated parameters were water flow rate of (10, 14 and 18) lit/min, air flow rate
of (1.5, 3 and 4) lit/min for subjected heat fluxes of (27264, 36316 and 45398) W/m2. The energy,
momentum and continuity equations were solved numerically to describe the motion of flow.
Turbulence models k-ε was implemented. The mathematical model is using a CFD code Fluent
(Ansys15). The water was used as continuous phase while the air was represented as dispersed
phase. The experimental work includes design, build and instrument a test rig for that purpose. A
circular vertical copper pipe test section of (length=0.7m, diameter= 0.05m, thickness= 1.5mm) is
designed and constructed, heated by an electrical heater fixed on its outer surface. Water
temperature at inlet is kept constant at (32°C). Water inlet and outlet temperatures, as well as radial
temperature distribution within the pipe at seven sections along it between pipe surface and its
center are measured. The results revealed that the secondary flow created by air bubbles have
significant effects on heat transfer enhancement and temperature profile. It is observed, that
averaged Nusselt number enhancement for low heat flux of 27264 W/m2 and 4 lit/min air bubbles
was 33.3 % and 23% in numerical and experimental, respectively.

This paper presents a complete design and implementation of a monitoring system for the
operation of the three-phase induction motors. This system is built using a personal computer and
two types of sensors (current, vibration) to detect some of the mechanical faults that may occur in
the motor. The study and examination of several types of faults including (ball bearing and shaft
misalignment faults) have been done through the extraction of fault data by using fast Fourier
transform (FFT) technique. Results showed that the motor current signature analysis (MCSA)
technique, and measurement of vibration technique have high possibility in the detection and
diagnosis of most mechanical faults with high accuracy. Subsequently, diagnosis system is
developed to determine the status of the motor without the need for an expert. This system is based
on artificial neural network (ANN) and it is characterized by speed and accuracy and the ability to
detect more than one fault at the same time.

The present paper deals with experimental investigation of the performance of air cooled split air
conditioner, with evaporative water mist pre cooling to increase the cooling capacity and reduce the
consumption power under hot and dry climate. This investigation considers how the performance
can be enhanced by using water mist to pre-cool ambient air entering the condensers by adiabatic
cooling process which depends on the ambient air wet bulb temperature; as well the condensing
temperature and condensing pressure will be decreased accordingly. So the cooling capacity would
be increased and consumption power would be decreased, consequently the energy ratio, EER
would be improved. The performance of air cooled air conditioner with water mist pre cooling;
ECAC was compared to the performance of air cooled air conditioner, ACAC which tested under
the same ambient condition that is ranged from 25oC to 52oC. Test results show that ECAC
operating at EER of 10.5 BTV/W. The ECAC had an EER of 47 % higher than that of ACAC under
the same and most serve hot and dry condition of 52oC and 10% relative humidity.

Soft clays are generally sediments deposited by rivers, seas, or lakes. These soils are fine
grained plastic soils with appreciable clay content and are characterized by high compressibility
and low shear strength. To deal with soft soil problems there is more than one method that can
be used such as soil replacement, preloading, stone column, sand drains, lime stabilization and
Prefabricated Vertical Drains, PVDs. A numerical modeling of PVD with vacuum pressure was
analyzed to investigate the effect of this technique on the consolidation behavior of fully and
different depths of partially saturated soft soils. Laboratory experiments were also conducted by
using a specially-designed large consolidmeter cell. Five tests were conducted with a vacuum
pressure of about 40 kPa applied for a period of 30 days where the degree of consolidation
reached 75% based on pore-water pressure distribution. The results showed that using vacuum
pressure with vertical drains reduces the consolidation time by about 68%. Existence of an
unsaturated soil layer decreases settlement of soil by about 22%, 32%, 425, 54% as the
unsaturated depth increases by 1/8, 1/4, 3/8, and 1/2L respectively and causes a rapid increase in
soil pore-water pressure.

This paper addresses the use of adaptive sliding mode control for the servo actuator system with
friction. The adaptive sliding mode control has several advantages over traditional sliding mode
control method. Firstly, the magnitude of control effort is reduced to the minimal admissible level
defined by the conditions for the sliding mode to exist. Secondly, the upper bounds of
uncertainties are not required to be known in advance. Therefore, adaptive sliding mode control
method can be effectively implemented. The numerical simulation via MATLAB 2014a for servo
actuator system with friction is investigated to confirm the effectiveness of the proposed robust
adaptive sliding mode control scheme. The results clarify, after comparing it with the results
obtained by using classical sliding mode control, that the control efforts are reduced and the
chattering amplitude is attenuated with preserving main features of the classical sliding mode
control.

The role of drain in agricultural lands is to remove excess surface and subsurface water to
create a good environment for root growth and to increase crops yield. The main objective of this
research was to evaluate the performance of closed drains when using textile filter instead of
crushed gravel filter. The research has been executed in the laboratory using a sand tank model and
by using two types of the soil. One of soils was light soil (sandy soil) and the other heavy soil
(loamy soil). The tests were classified into four cases; each case was supplied discharge during 10
days. The results showed that the amount of out flow when using graded crushed gravel filter is
greater than the amount of out flow in case of using textile filter for the same soil; and the amount
of sediment in applying graded crushed gravel filter for the two types of soils was greater than using
textile filter. The entrance resistance for textile filter was greater than graded crushed gravel filter
and the entrance resistance increase for the two types of filters with time. From the results it can be
concluded that the graded crushed gravel is more efficient than the textile filter in sandy soil, while
when using the two types of filters with loamy soil the results showed that the two types of filter
exhibited low work efficiency.

The high and low water levels in Tigris River threaten the banks of the river.
The study area is located on the main stream of Tigris River at Nu’maniyah City and the
length of the considered reach is 5.4 km, especially the region from 400 m upstream
Nu’maniyah Bridge and downstream of the bridge up to 1250 m which increased the
risk of the problem that it heading towards the street and causing danger to nearby areas.
The aim of this research is to identify the reason of slope collapse and find
proper treatments for erosion problem in the river banks with the least cost. The
modeling approach consisted of several steps, the first of which is by using “mini” JET
(Jet Erosion Test) device provides a simple method of measuring scour depth with the
time for the riverbank and finding values of critical shear stress and erodibility factor for
ten soil samples taken from right bank and bottom of Tigris River; the second of which
involved setting up a static BSTEM software for two models (with and without
treatment), then calculating the erosion amounts and factor of safety for the ten soil
samples; the third approach involved implementing a two dimensional RMA2 to
simulate four scenarios to find the velocity, water depth, and water surface elevation
distributions for two models (with and without treatment). Therefore, observed erosion
in other discharges in natural case near the right bank [especially at cross section that
are located in Tigris River at Nu’maniyah City from 500 m upstream Nu’maniyah
Bridge and cross section that are located from 1800 m downstream Nu’maniyah Bridge]
is high because of high erodibility coefficient in those cross sections that causes high
erosion. Also, failure occurs in natural case of Tigris River at Nu’maniyah City because
of erosion near the right bank and does not occur because of slope stability failure for
right bank where the range of the velocities near the right bank for the study area for
most discharges is between 0.67 and 0.91 m/s. In addition to experimental work using
"mini" JET device shows high erodibility coefficient in those cross sections and
(2+900) which confirms that this device is very good indicator for the possibility of
bank scour. The velocities upstream of the island and near the right bank in the study
area are between 0.64 and 1.47 m/s, while downstream of the island is between 0.64 and
1.04 m/s. In addition to soil of Tigris River right bank at Nu’maniyah is silty soil, the
scour velocity is higher than 0.5 m/s, therefore the right bank is safe against scour only
when the discharges of Tigris River are less than 500 m3/s. Thus, vegetation is unsafe
treatment on right bank of Tigris River at Nu’maniyah City. The velocity causes
removal of plants since treatment for river bank is 0.61 m/s where velocities near bank
at most discharges are higher than this limit. Thus, treatment by riprap is the proper
choice on the right bank of Tigris River at Nu’maniyah City because its cost with
maintenance is 2 billion IQD less than gabion treatment in addition to velocity reduction ratio along the right bank by riprap ranges from 15% to 85%, while velocity reduction
ratio along the right bank by gabion ranges from 8% to 25%, respectively.
Key words: erosion, cost, SMS, riprap, gabion, vegetation.

Flexible pipes, such as GRP pipes, serve as effective underground infrastructure especially as
sewer pipeline. This study is an attempt for understanding the effects of bedding types on the
behavior of large diameter GRP flexible sewer pipes using three dimensional finite element
approaches. Theoretical and numerical analyses were performed using both BS EN 1295-1
approach and finite element method (ABAQUS software). The effects of different parameters are
studied such as, depth of backfill, bedding compaction, and backfill compaction. Due to
compaction, an increase in the bedding compaction modulus (E’1) results in a reduction of both
stresses and displacements of the pipe, especially, for well compacted backfill. An increase of
(E’1) from 14MPa to 30MPa results in a reduction in stresses 40% and about 25% in
displacements. Maximum reductions in stresses were found to be about 25% only while the
reduction in displacement was found to be less than 10%. As backfill material compaction
modulus (E’2) is increased from 14MPa to 40MPa, a maximum reduction in stresses within the
pipe was found to be not less than 60% while the displacement reduces up to 65%.

Recycling process presents a sustainable pavement by using the old materials that could
be milled, mixed with virgin materials and recycling agents to produce recycled mixtures.
The objective of this study is to evaluate the impact of water on recycled asphalt concrete
mixtures, and the effect of the inclusion of old materials into recycled mixtures on the
resistance of water damage. A total of 54 Marshall Specimens and 54 compressive strength
specimens of (virgin, recycled, and aged asphalt concrete mixtures) had been prepared, and
subjected to Tensile Strength Ratio test, and Index of Retained Strength test. Four types of
recycling agents (used oil, oil + crumb rubber, soft grade asphalt cement, and asphalt
cement + Sulphur powder), were adopted to prepare recycled mixtures, and the recycling
agent of (soft grade asphalt) was used to prepare mixtures with further old materials
contents. It was found that the Tensile Strength Ratio exceeds 75% for all recycled
mixtures, and the recycled mixture with (oil + rubber) and 50% old materials content, had
the highest Tensile Strength Ratio value comparing to other recycled mixtures. Results of
Index of Retained Strength showed that mixtures with (Soft Ac) and (Ac + Sulphur) and
50% old materials, exceeded the Index of Retained Strength value for virgin mixture.
Index of Retained Strength values decreased as the old materials content increased, Index
of Retained Strength was (80.5%, 74.5%, 71.6%, and 67.62%) for recycled mixtures with
(50%, 60%, 70%, and 80%) old materials content respectively.