Engineering and Technology Journal

Corrosion is a term defined as oxidation of a metal, which is observed in many parts. A structure is subjected to fatigue loading when a certain load is applied repeatedly. If this structure which was subjected to prior corrosion, under fatigue load, it reaches destruction far faster than that subjected in an inert environment. The aim of this work is to study the effect of the prior corrosion on fatigue behavior of steel alloy CK35 under constant amplitude stress. The NaCl solution used in this investigation is a 3.5wt% mass mixture of sodium chloride (NaCl) salt and distilled water corresponding approximately to the composition of sea water. The samples are immersed in the solutions for 80 days on the solution that replaces every eight days to maintain the concentration of the solution. The results observe that the fatigue life decreases in different percentage at different constant stress amplitude loading. The highest decreasing life factor is in range (9-29.3%) at amplitude stress in range (77- 62% of????????) while the decreasing life factor is in range (68.7-40.2%) at amplitude stress in range (46-31% of????????). Also the experimental results show that prior corrosion for 80 days reduce the fatigue limit of steel alloy CK35 for 13.229%

This paper presents a study for optimal performance of a robot to be used in human surgery (Laparoscope device). He was done in Al-Sader educational hospital in maysan Governorate. The robot was manufactured by Karel Storez company. Connecting linkages were increased to get seven degrees of freedom.
The optimal performance was obtained by using genetic algorithm method to choose the optimal path planning in the working area, this was done by making an integrated computer program through MATLAB language (R2013a).The results of best path planning would shorten length without hitting any obstacle, assuming the surrounding environment will be variable, the position and obstacle shapes would be random. We found that the best path planning in every environment depends on objective function. The practical side was made in laboratory of the Research Unit of Automation and Robotics in the Control and Systems Engineering Department, University of Technology. The robot used was the Lab-Volt Servo Robot System Model 5250 (RoboCIM5250).

The current study focused on the manufacturing and development properties of upper prosthesis complete denture from composite materials with the basis cold cured resin of poly methyl methacrylate as new fluid resin and reinforced materials by two different types of particles (nano-hydroxyapatite (nHA), micro zirconia (ZrO2)), that added with different volume fractions of (1%, 2% and 3%), and the different types of woven fibers (Glass fiber, Kevlar fiber), it were added with a fixed volume fraction of (5%) to PMMA composites. Specimens’ consist of a six groups where prepared by using (Hand Lay-Up) method from the composites materials and hybrid laminated composites materials. This research includes theoretical and numerical studies by using finite element method to confirming the experimental results of the effect of selected volume fractions of these particles and fibers on the (total deformation distribution, equivalent elastic strain and equivalent Von Mises stress) of the composite prosthetic dentures.
The theoretical part included calculations the values of theoretical safety factor and Poisson's ratio. While the numerical part based on finite element method (F.E.M), which was performed by using program (ANSYS-15) to analyze the prepared of denture composite materials and evaluate its characteristics which represent total deformation distribution, equivalent stress and equivalent elastic strain. This was performed by obtaining twenty one models for the PMMA composite dental prostheses which were treated as three dimension structure. The numerical results of the F.E.A showed coincided with some of the experimental results

This research deals with the improvement of the mechanical properties of expansive clay soils by silica fume. The expansive soil was prepared in laboratory by mixing natural soil brought from (Nahrawan) city with different percentages of Bentonite (30, 50 and 70% by weight). The test program included the effect of Bentonite on natural soil then study the effect of silica fume on prepared soil by adding different percentages of silica fume (3,5, and 7% by weight) to the prepared soils and the influence of these admixtures were observed by comparing their results with those of untreated soils (prepared soils). The properties chosen for this comparison were specific gravity, the consistency limits, swelling percent and swell pressure. The results show that the plasticity index, the optimum moisture content, swelling percent and swell pressure increase with increasing the Bentonite percent, and the maximum dry density, specific gravity decrease with increasing the Bentonite percent. When the prepared soil treated with silica fume, the results show that plasticity index, specific gravity, maximum dry density swelling percent and swell pressure decrease with increasing the silica fume percent, while optimum moisture content and unconfined compressive strength increased with increasing silica fume percentages. And the perfect percentage of silica fume was obtained to be 7% which where decreased the swell and swell pressure in large percent

Cold forming processes are the common processes in sheet metal forming, especially in the final stages of production processes. In this work, cold rolling process was selected to study the effect of different reduction ratios on the residual stresses state in aluminum alloy (2024). Sheets of aluminum alloy (2024-T3) were prepared with dimensions (400 X 80 X 3.15 mm). The annealing process was conducted for these sheets to get the temper condition (2024-O). The cold rolling process was performed with different reduction ratios (10%, 20%, 30%, 40%, 50%, 60%) by a rolling machine composed of two rolls having (50 mm) diameter each. The residual stresses were measured using X-ray diffraction technique (XRD) in two directions (rolling direction RD, and transverse direction TD). The results of X-ray diffraction showed the presence of residual stresses at the surface of rolled specimens, and these were compressive stresses in the two tested directions (RD, and TD) at 10% reduction ratio. When the reduction ratio exceeded 10%, these stresses transformed to tensile stresses for specimens tested in rolling direction, while these stresses remained compressive type for all reduction ratios in

In this work, the stresses and dynamic crack growth were studied and analyzed in thin flat plate with a surface crack at the center, subjected to cycling low velocity impact loading for two types of aluminum plates (2024, 6061). Analytical solution using
classical plate theory by using Levy solution employed to determine stresses induced in
plate due to the impact load. The impact load applied at the center of surface plate, was
calculated by Hertzian contact law. Stresses with respect to time at the crack tip and the
velocity of crack growth were calculated through elastic plastic fracture mechanics
equations. The size of plastic zone around the crack tip which caused by impact loading
was found by Dugdal’s model theory. Numerical analysis using program (ANSYS11-
APDL) based on finite element method used to analysis the stresses with respect to time
at crack tip and then find the velocity of the crack growth under cycling impact loading.
The results show that the stresses increase with increasing in the crack length
(i.e:160Mpa at 7mm and 175Mpa at 10mm for Al-6061 also 140Mpa at 7mm and
165Mpa at 10mm for Al-2024).. It was found that the cumulative number of cycles leads
to increase in the stress values with increasing in crack growth velocity.

Styrene butadiene rubber (SBR) and natural rubber (NR) composites reinforced with alumina (Al2O3) and precipitated silica (SiO2) particles had been prepared separately by calendaring process. It had been studied the adding effect of the alumina and silica particles separately at different ratio (5, 10, 15, 20, and 25 pphr٭)
on the tensile characteristics of natural rubber NR and styrene butadiene rubber SBR.
The results show that the tensile characteristics increase with the increase loading
level of the both reinforcing particles. The maximum values of the tensile
characteristics were for natural rubber as compared with styrene butadiene rubber,
and the reinforcing effect of silica particles higher than of alumina. The results
indicate that the maximum tensile strength at break, modulus of elasticity, and
elongation percentage at break were (70MPa, 18, 350%) respectively for natural
rubber reinforced with (25 pphr) of SiOR2

In this study viscosity )η ( of diglycidyl ether of bisphenol A / triethylenetetramine
(DGEBA/TETA) system were measured through curing using a Brookfield viscometer at
four different temperatures (30, 45, 60 and 80) °C. The measurements were carried out
for two hardener/resin ratios (13 and 20) phr. The gel time was calculated for each
hardener/resin ratio formulation; from the viscosity experimental data. The results
showed that the gel time decrease with increasing curing temperature for each
hardener/resin ratio formulation. Viscosity profiles were described by a model based on
the Boltzmann function. The fitted results agreed well with the experimental values

A new generation of Ultra High Performance Concrete (UHPC) named Reactive Powder Concrete (RPC) was developed in the last decades, which offers, superior strength, durability and ductility. One of the main differences between other concretes and RPC is that the latter requires mechanical models capable of taking tensile behavior into account for structural application to enable the material to be fully exploited. The complete stress-strain relationship under direct tensile test and uniaxial compression of different RPC mixes was experimentally investigated. Nonlinear equations are suggested to model the complete tensile and compressive stress-strain relationship for all the RPC mixes studied. In this research an analytical study is devoted to establish a simple equation for predicting the nominal bending moment capacity Mn of plain and singly reinforced rectangular RPC beam sections. The equation derived showed good agreement with all the flexural test results performed in previous researches and some other investigations on reactive powder concrete beams

In this study, a lab scale different activated sludge configurations methods were used to treat a municipal wastewater from effluent of ;primary sedimentation tank of Al-
Rustamiya wastewater treatment plant located near Baghdad city to remove organic load,
nitrogen and phosphorus from the period of 15 July 2012 to 22 May 2013. Biological
treatment systems were conventional activated sludge (CAS) , extended aeration ,
anaerobic-anoxic-aerobic( A2O) , anoxic-aerobic (MLE) and anaerobic –oxic(A/O).
During the operation periods, the average removal efficiency of BODR5R, COD and TSS is
81.9, 77.7 and 85.8 respectively regardless of the fluctuation in influent quality. In
addition the results show removal efficiency of ammonia, nitrate, nitrite and phosphorus
with ranges (61-85.8), (34-81.7) , (35-81.4) (32.3-85.54) % respectively. The biological
treatment systems produced high quality effluent which can achieve the Iraqi limitations
of rivers maintenance for all measured parameters

In the course of expansion in turbines steam nucleates to become a two phase mixture, the liquid consisting of a very large number of extremely small droplets carried by the vapor. Formation and subsequent behavior of the liquid lowers the performance of turbine wet stages. The calculations were carried out assuming that the flow is two dimensional, compressible, turbulent and viscous. A classical homogenous nucleation model applied for the mass transfer in the transonic conditions. The aim of the present study is investigation of outlet pressure effect on second phase generation in a steam turbine. The conditions at inlet to the test section were varied from a wet equilibrium to a superheated state by changing the cascade exit pressure. Experimentally it was found that the most important influence of rapid condensation on the pressure distribution is occurred on the suction surface and it grows by decreasing the downstream pressure. Pressure profiles around the blades are compared with the experimental data and good agreement is observed. The maximum and minimum of droplet numbers have been achieved and nucleation zone has been specified in blade passage.

Knowing of flow resistance in channels is necessary for many purposes such as the estimation of stage-discharge relationship, and the evaluation of sediment transport from the hydraulic characteristics of the channel by means of transport formulas. All relationships between Froude number (Fr)and Mainning’s roughness coefficient(n) lead to obtain useful information in design, implementation, minimization the construction cost, and design the economical section.
The goal of the present work is to investigate experimentally the effect of Manning roughness on Froude number in open channel in subcritical flow, as well as, to establish some relations between different parameters, like Froude number with Manning’s Roughness coefficient, velocity and head, in order to find useful relations.
Two different cases have been adopted in this study. The first one is to predict relationships from the concrete lining irrigation canal, and the second is to procedure conducted in a selected reach of a natural stream Main Outfall Drain Project (M.O.D.) with two sectors of Mahmudiya, and J ׳bala as a case study.
In this invistgation on lined irrigation canal, the relationship between Fr and n appears as a polynomial relation of the fourth degree and a moderate relationship between of
them.

In an experimental analysis study, a mix of burnishing parameters was varied to obtain the optimum roller conditions that produce superlative surface smoothness and hardness. The analysis was undertaken on roller burnished mild steel and aluminium using a purpose designed and manufactured tool. The effects of burnishing parameters on both the surface roughness and hardness of mild steel and aluminium work pieces materials were observed and analysed. The parameters included; burnishing speed, feed, force and the number of the tool passes. The results indicated that, depending on the work piece material, surface finish and hardness improvements of around (75%) and (50%) respectively were obtainable at optimum values of the mentioned parameters

Spatial Multiplexing (SM) can be achieved higher transmission rate without allocating higher bandwidth or increasing transmit power, so it is wildly used recently to serve the extremely demand of mobile communications. But multipath fading is major bottleneck in increasing the data rate and reliability of transfer of information over wireless channel. SM suffers from significant degradation in term of Bit Error Rate (BER) in such environments. In this research it has been tested a SM system with three types of detection. The first results show the Maximum Likelihood (ML) is the better one, but the complexity is increased dramatically with increasing of data rate or the level modulation order in addition of delay time. On the other hand, Zero Forcing (ZF) is very simple related to ML and it suitable for real time communications, but the problem is the Bit Error Rate (BER) is very high related to the performance of ML. So that this research proposed to adopt ZF decoder, and to support its performance, Convolutional Codes (CC) is added to this system to overcome this problem. The results show the proposed scheme gives a gain of about 10 dB of Signal to Noise Ratio (SNR) at BER of 10-4 for code rate of ½ of CC. To reduce the redundancy informations of CC, 2/3 code rate is proposed instead of ½. The results illustrates such system gives significant gain at high SNR, but the problem is the BER in increased up to system with code at low SNR. Also the results confirm that this problem decreases with high number of antennas. So that MIMO system is suitable for high data rate

In this study ,spatial video camera was used to capture field data required to establish a geospatial data base that was used with ArcGIS Network analyst for the development of a methodology for the optimization of MSW collection in limited area that have barriers enclosing some roads as a precaution procedure. The method uses various geographical data (road network, location of waste bins, and location of barriers), to measure the difference in time traveled by collecting vehicles. The Results indicate that the presence of barriers increasing the distance traveled by collecting vehicles (23%) in comparison with no barrier scenario each time .With the collecting interval twice a week, this means that a saving of two trips each month if the barriers removed. The study demonstrated the value of spatial videos and GIS as decision making tools

The main aim of this research is to study the effect of using hooked end steel fiber on the fresh and hardened properties of self-consolidating concrete. The experimental work includes two stages. First stage involved conducting several trial mixes and then choosing the one that conform to the international standards in terms of fresh properties. Second stage concerned on the compressive, flexural tensile and splitting tensile strengths evaluation of the selected mixes, at 28 and 90 days. Four concrete mixes were obtained and evaluated. They were similar in mix proportions and differ only in volume fractions of steel fibers incorporated: 0%, 0.5%, 1%, and 1.5%.
Results showed that adding hooked steel fibers adversely affect SCC workability and thus more dosage of SP should be added to stay within the standard limits. Similar to conventional HPC, the presence of steel fibers with SCC provide slight increase in compressive strength at 28 days, (up to 11%), while significant enhancement

Abstract
In recent years, there is a dramatic progress in the development of theories for dynamic analysis of piles. The finite element method is a numerical approximation procedure to analyze physical problems by transforming them into mathematical models. This needs to be done numerically because it is either too complicated or impossible to solve problems by classical analytical methods.
In this study, a three- dimensional analysis by using finite element method will be adopted to predict the displacement response of pile foundation due to dynamic loads. A case study is carried out to investigate the effect of particles size of soil, length of pile, spacing between piles and pile cap size on the dynamic response of pile foundations.
The results indicate that, the maximum amplitude of displacement of pile foundation under dynamic loads can be occurred in loose sand in comparison with the other types of sand. In addition, the increase in pile length will lead to decrease in the amplitude of displacement due to increases in the mass of the foundation

In this work, we study a diagnostic of a copper-plasma in air using a fundamental wavelength of a Nd: YAG laser system. The optical emission spectra of copper-plasma that have been detected using a spectrum analyzer (Thorlabs GmbH) have been used to extract the excited plasma temperature via the Saha-Boltzmann method, and measure the electron number density by McWhirter criterion. Measured values of Ne and (Te) is in the range of (14890.827 K°) and (Ne) is (2.7*1015 cm-3) at the fundamental wavelength

Fingerprint authentication and recognition is an important subject that has been widely used in various applications because of its reliability and accuracy in the process of authenticating and recognizing the person's identity. In this paper, an Intelligent Fingerprint Authentication Model (IFAM) based upon the neural network has been proposed. The proposed work consists of two main phases which are the features extraction and the authentication. The features extraction phase has been regarded via proposing a statistical and geometrical approach for determining and isolating the features of the fingerprint images. The proposed approach is called the Features Ring Approach which is abbreviated by FRA. The approach creates a circular ring centered at the core point of the fingerprint to bind the valuable features that are invariant under rotation and translation. The radius of the outer circle of the ring is suggested to be variable to give a variable area for the established circular ring.
The authentication phase of IFAM suggests the neural network to hold the job of verification of the extracted feature patterns resulted by FRA for a fingerprint image of certain person. This is done using a neural network trained with a collection of features patterns extracted from fingerprint images. Backpropagation (BP) is suggested as a training algorithm for the structured neural network

The paper deals with behavior of machine foundation on elastic foundation. The finite elements approach through ANSYS (version 11) computer software is used for simulation of the dynamic response of the foundation under harmonic loading. As a case study previous analytical analysis problem for machine foundation was reanalyzed. In this problem, the element (solid65) was used for modeling the reinforced concrete foundation whereas the element (solid45) was used for modeling the soil beneath the foundation. The interface is modeled by using three-dimensional surface-to-surface (Target170 and Contact174) contact elements connected with concrete and soil.
It can be noted that the finite element analysis agrees with the analytical results, and the difference in the ultimate displacement is about (7.14, 4.6, 27.6, and 12.5)% when the dynamic force is subjected (along X direction (in-phase), along X direction (out of phase), along Y direction (in phase) and along Y direction (out of phase)) respectively