Engineering and Technology Journal

This research is concerned with behavior of composite steel-concrete arches
under static load. For this purpose, eight models of composite steel-concrete arches
are fabricated as test specimens.According to their supporting systems, the eight
fabricated specimens are equally divided into Hinge-Roller and Hinge-Hinge
supported arches in which varied numbers of shear connectors are used to investigate
the effects of support conditions and degree of shear connection on the behavior of
the composite arches. The specimens are tested under monotonically increasing point
load applied on their crowns (on the top of concrete slabs).
The mechanical properties of the used materials are determined by laboratory
tests. Push-out tests on three specimens, fabricated for this purpose, are also carried
out to determine the properties of the stud shear connectors.
It is concluded that increasing the number of connectors tends to increase the
ultimate load capacity and decrease both displacement and slip in the composite
arches. This trend is considerably satisfied when the horizontal movements of
supports are constrained (Hinge-Hinge supported arches).

Stone columns technique is most commonly used in increasing bearing capacity,
reduces and controls the compressibility and accelerates the rate of consolidation of soft
saturated clay. During the last four decades, the technique has been utilized worldwide
and proved successful results. Several modifications have been proposed to increase the
efficiency of this technique such as addition of additives, use of special patterns of
reinforcements, encasing the stone columns with geonet or geogrid to provide extra
confinement that enhances the bearing capacity and reduces the settlement drastically
without compromising its effect as a drain.
The present paper focuses on the behavior of soft saturated clay reinforced with
ordinary and geogrid encased stone columns. The investigation was performed both
experimentally through small scale models and through numerical techniques. The
influence of relative density of the back fill material and the presence of the encasement
are the main parameters investigated.
Ordinary stone columns revealed an increase of 20% in the carrying capacity when
the relative density of the backfill stone aggregates increased from 23% to 71%,
furthermore the efficiency of the encasement was more pronounced at lower relative
density.

This studying deals with the study of the effect of fiber volume fraction of the
carbon, glass and Kevlar fibers and their orientation on the properties of Hybrid
composite material. Different percentages of carbon, glass and Kevlar fibers were
used to reinforce the matrix material (unsaturated Polyester). The fibers arranged in
two methods according to the direction of the thermal flow. In the first method the
fibers were parallel to the direction of the thermal flow, while the second method was
perpendicular. The thermal conductivity measured by using Leeś disk. The
experimental and theoretical results proved that the value of the of thermal
conductivity increased with increasing the fiber volume fraction of the carbon
,Kevlar-49and glass and then reduced for Hybrid (H7and H8) for both arrangement
parallel and perpendicular because do not hah carbon fiber. The thermal conductivity
of parallel orientation had the highest value, while the carbon factor was the best. The
experimental results of thermal conductivity for parallel arrangement indicated that
the hybrid (H6) had maximum value 3.40 W/m.k and for perpendicular was 0.245
W/m.k for hybrid (H3).

This research is interest in increasing the strength of spot welding joint for thin
commercial Aluminum by adding casting component to the welding zone in the form of
powder. Those components are copper, manganese and magnesium which are added in a
different percentages it appear that the strength of the spot welding has been improved
by (14.5%) when adding(0.4 grams of magnesium),(0.1 grams of manganese ) and (0.4
gram of copper).
The powder is added in the welding zone boundary after made a single hole with a
depth of (0.375mm) and a diameter of (1mm) in the center of spot welding point.
To increase the welding strength, five holes have been made with the same above
dimensions through the welding zone boundary. The percentages of additive used after
reparation the reduction of Aluminum powder.
The value of shearing strength increase with a percentage of (27.3%) as comparing
with those without additive.
Also, heat treatment has been done, which gave a redaction in the strength of spot
welding. It has been observed that the increase in the temperature of heat treatment
result in decreasing in the spot strength. Welding and cooling environment have an
effect on the strength of welded specimen. Hence, air welding environment gives a good
welding strength.

This work confirms results indicated by previous research that uniformly
distributed loading leads to higher reinforced concrete (RC) beam shear capacitycompared
to 1 or 2 point loading. Different design methods are compared in this
investigation, including those by ACI (1) and other Codes.
Twelve beams, without stirrups, are tested in this work to farther investigate the
influence of distributed loading. Two design equations are proposed in this work, one
includes the size effect and the other without it. The former has proved to be the more
accurate.
Of 200 test results obtained from the literature, the proposed design equations
lead to a COV value of Vtest /VDES of 16.8% and 17.1%. These compare favourably
with other design methods.

The current study deals with obtaining the high performance mortars to use in the
applications of ferrocement. The main problem that has greatly affected the
performance of mortar is the workability. A low water-cement ratio mostly resulted in
increases in the compressive strength and led to the enhancement of durability
characteristics, but decreases in the workability.
Workability becomes an important factors, as the mortar has to easily penetrate
between the layers of the mesh wires. A reasonably workable with high strength
cement mortar can be obtained by using a high cement content coupled with the use
of silica fume and superplasticizers. In this investigation a series of compression tests
were conducted on 50 mm cube and 150 ×300 mm, cylindrical specimens to obtain
the compressive strength and the stress-strain behavior of mortar with silica fume and
superplasticizers and flexural tests were conducted on 50 ×5 0 × 200 mm prism to
obtain the modulus of rupture. The results of this study indicated that the variation in
mortar strength depend on the water-to-binder ratio of the mix and percentages of
cement replacing. The effects of these parameters on the stress-strain curves are
presented. The best replacement percentage of silica is 3% was concluded in this
study. From the experimental results a mathematical model has been developed to
predict the 28-day compressive strength of silica fume mortar with different water-tocementitious
ratios and superplasticizers percentage

Finding the amount of plastic deformation into metallic plates,metallicstructures,
ships frame, bodies of different types of cylinders and reservoirsbodies as a result of
exposure tostaticor dynamic forceis so necessary todetermine the extent
ofdistortionand destructionhappening intheseobjects and this is one of the main
factors in design calculations to determine the dimensions and thicknesses of these
bodies. Derivation anew theoreticalmodelto calculate theamount of work and
forcerequired to bulge the sheet metalisa very important targetbecause of the lack of a
theoretical relations to calculate the work of plastic deformation with good
approximationoridenticalto exact required work and force; or vice-versa to find the
amount of plastic deformation as a result of a specific work or specific force.This was
donein this research where a theoretical model has been derivedthrough the expense
of work and force necessary to generatebulging in sheet metal. This theoretical model
has been adopted on the mildsteel plates which are of wide application in practical
life. Results obtained from the theoretical model were compared with those obtained
from tests conducted onsimply supported circular steel plates made from low carbon
steel ,milled steel , of a (280) mm diameter and (1,2, 3, 4,5, 6, 8,10) mm thickness
andexposed to central force applied by a flat ended punch of 10 mm diameter. The
applying force was increased gradually till it caused plastic deformation in the sheet,
and then reached the state of shear of the disk, which is locatedunder the punch.
Results comparison appear matchorsubstantial convergence between the practical
resultsand those obtained from the theoretical model to find the work and for ceit
takes to plastic deformation in the tested plates.

This study aims to analyze the Diyala weir problems and compares it with the
safe limit and proposes the treatment for these problems. One of the most influencing
problems in the site of weir was the formation of the hydraulic jump, it was found
that the scour occurs due to the position of the hydraulic jump and the sequence depth
of the jump is higher than the tail water depth. Some treatment procedures are
suggested, these treatments cover this problem by presenting a suitable stilling basin
as well as recommended to use a low weir at end of basin to produce a back water
curve that should be increase the stage of tail water and ensuring the stability of a
hydraulic jump

This paper introduce an approach to study the effects of different levels of
environment noise on the recognition rate of speech recognition systems, which are
not used any type of filters to deal with this issue. This is achieved by implementing
an embedded SoPC (System on a Programmable Chip) technique with Altera Nios II
processor for real-time speech recognition system. Mel Frequency Cepstral
Coefficients (MFCCs) technique was used for speech signal feature extraction
(observation vector). Model the observation vector of voice information by using
Gaussian Mixture Model (GMM), this model passed to the Hidden Markov Model
(HMM) as probabilistic model to process the GMM statistically to make decision on
utterance words recognition, whether a single or composite, one or more syllable
words. The framework was implemented on Altera Cyclone II EP2C70F896C6N
FPGA chip sitting on ALTERA DE2-70 Development Board. Each word model
(template) stored as Transition Matrix, Diagonal Covariance Matrices, and Mean
Vectors in the system memory. Each word model utilizes only 4.45Kbytes regardless
of the spoken word length. Recognition words rate (digit/0 to digit/10) given 100%
for the individual speaker. The test was conducted at different sound levels of the
surrounding environment (53dB to 73dB) as measured by Sound Level Meter (SLM)
instrument.

Traditional high-frequency pulse width modulation (PWM) inverters for motor drives
have several problems associated with their high switching frequency which produces
high voltage change (dv/dt) rates. Multilevel inverters solve these problems because their
devices switch at the fundamental frequency. The concept of multilevel voltage source
inverter is explained. In this paper the cascade inverter is a natural fit for induction motor
drives because of the high VA ratings possible and it uses several levels of separate equal
dc voltage sources which would be available from batteries or fuel cells. The switching
angles of switch devices are determined by optimized harmonic stepped waveform
(OHSW) technique to reduce the output harmonics of cascade multilevel inverter (CMLI)
for induction motor is proposed, as a result the efficiency of system has improved.
Simulation results show the superiority of this inverter over 2-level inverter and were
carried out using ORCAD package.

Neural network technology plays an important role in the development of new
medical diagnostic assistance or what is known as “computer aided” that based on
image recognition.Thispaper study the method used integration of back propagation
neural network and Particle Swarm Optimizing (PSO) in parts of recognition the XRay
of lungs for two disease cases (cancer and TB) along with the normal case. The
experiments show that the improvement of algorithms for recognition side has
achieved a good result reached to 88.398% for input image size 1024 pixel and 500
population size. The efficiency and recognition testes for training method was
performed and reported in this paper

In this work an Aluminum matrix composite reinforced with alumina prepared by insitu
(liquid-gas) method were investigated. Gas was represented by an oxygen with flow
rate 50, 100, and 150 Sml/min (Standard mile Liter/minute) at different temperature
(720, 740, 760 and 780 °C). The effects of reaction temperature on alumina particle size
and alumina volume fraction were studied extensively. Resulted alumina was identified
by using XRD and SEM techniques. The resulted composites were characterized using
density and hardness tests. It is found generally, that the alumina particle size was (3 ± 1
μm), the density and hardness are decreases as the alumina particles weight percent
increases. The reason behind such behavior was the increment in porosity around alumina
particles and also to the weakness in wettability between alumina and metal matrix.
Furthermore, it is noted that, there are many problems need to be resolved like
segregation, agglomeration and weak of wettability are occurred between the particles
surface and matrix.

Electrical discharge machining (EDM) is a process where the material removal of the
workpiece is achieved through high frequency sparks between the tool (electrode) and the
workpiece immersed into the dielectric solution. It is commonly used to produce moulds
and dies, to drill small, burr free holes and to make prototypes for the aerospace and
electronics markets. In this work, micro-holeswere fabricated on copper alloys by using
EDM. The output responses investigated was electrode wear weight (EWW). Full
factorial of Design of Experiment (DOE) module in Minitab was used as a principal
methodology to examine the effects of current and machining time over output responses.
Experimental results indicate that the EWW was mainly affected by current, and can be
reduced by increasing the current parameter. Minimum EWW (0.12gm) obtained at 10A

Deep drawing process is an important industrial processes where it has been
extensively used. It is a process for converting the blank metal to make cylindricalshape
in most of the cases. A research program for performing basic calculations
related to the product shape was utilized. Eighteen geometric shapes have been
selected for the production in this process. The program is include the general
equations for this controlling process for each form. When choosing one of the shapes
in the program, the dimensions of the desired product are selected. In other words, the
inputs to the program are the required dimensions of the product before reaching the
required deportation. In addition, diameter, height and other related dimension are
computed which were chosen for each stage throughout the operation. Visual Basic
language was used to implement this program because of its ability to deal with
graphical interface. The program also accounts for a large number of mathematical
equations. Computer program is aimed to help designers templates deep drawing
quickly through the implementation of the process, and this exceeds the designer
experience that is required to perform the require calculations.

Thermal insulation is one of the main problems facing the engineers working in
building and housing sector spatially for the high summer temperature in the most
Arab Gulf and spatially in Iraq, so the study of lightweight aggregate thermal
insulation (No fine concrete) is important. The experimental work consist of concrete
mixes (cement: porcelinite aggregate) ratios (1:4), (1:5) and (1:6) and for each mixes
cement content changes (200, 300 and 400) Kg/m3. Dependence on mixing (1:5) and
cement content (300Kg/m3) change the water to cement ratio (0.4, 0.45 and 0.5) by
weight. The research presents the tests of density, absorption, porosity, ultrasonic
pulse velocity, accelerated compressive strength according to British standard (BS
1881: Part 112: 1983), normal compressive strength at 7, 28 and 90-day. Light weight
concrete was obtained of density ranging from (721-770) kg/m3 and thermal
conductivity ranging from (0.17- 0.24) W/ (m.K). The good correlation between
accelerated compressive strength at one day with normal compressive strength at 28-
day is approximately (0.245 ±0.005) for water bath at 55°C and (0.335±0.05) for
water bath at 82°C