ORIGINAL_ARTICLE
Effect of Graphite Particles Addition on the Wear Resistance and Friction coefficient of Brass Alloy (α)
This research is devoted to study the effect of different percentage of Graphiteparticles addition (5,10,15) wt% to Brass alloy (α) produced by stir casting using vortextechnique , on the wear resistance and the coefficient of friction under dry slidingconditions using pin-on-disk technique . Three loads (5, 10, 15) N were used at differentsliding speeds effect (2.7,3.7,4.7) m/sec . The results showed that the wear rate isincreased in general with increasing the applied load , but the composite materialreinforced with graphite particles showed wear rate lower than that of the base alloy .Thewear resistance of the composite material reinforced with graphite particles with 15 wt%was higher than that of reinforced with 5 wt% . When different sliding speeds were used, the results showed that , the wear rate is decreased with increasing sliding speed .Whenthe coefficients of friction was measured at high loads , It is clear that the compositematerial has low coefficient of friction as compared with that at low loads , while it isdecreased with increasing sliding distance at all used loads , and the composite materialreinforced with graphite particles showed remarkable decreasing in temperature whensurface temperatures were measured as compared with base alloy.
https://etj.uotechnology.edu.iq/article_30173_04df2d995e44645a844024e06e35e760.pdf
2009-04-01
218
233
10.30684/etj.27.6.20
Esraa
Abdel-Qader
1
AUTHOR
Maryam
Baqer
2
AUTHOR
ORIGINAL_ARTICLE
Effect of Current on Average Surface Roughness of Borosilicate Glass at EDM Machining and Comparison with Numerical Programs
Machining of electrically non-conducting materials like glass is still a major problem. The principle of electric arc was used to generate high electrical discharge (spark) at high currents to machine non-conducting materials at any hardness, which is a new approach.EDM system was build for machining of non-conducting cutting materials such as glass with new technology including the use of powder (graphite) mixed for dielectric solution (tap water) by supplied AC current values (200, 250, 300, 350 and 400A). Voltage of (70V) was used to cut 3mm thickness of borosilicate glass (BSG) to obtain the average surface roughness (Ra) of about (0.003-0.012μm) but the Ra before the machining was (0.005-0.006μm).Numerical program called "Simulent" has been used to investigate the process control for EDM by using GN, BPN, PN and VQN that could predict the Ra with accuracies of 94.236, 94.034, 96.628 and 92.875% respectively from training data sets.The differences on the Ra at different network models for 3mm thickness of BSG never exceed (8%) from testing data sets while the comparison of numerical results with experimental results of Ra among the measured values and prediction various network models, shows a differences between (1-8%).The best predication accuracy is by the use of PN than other network models.
https://etj.uotechnology.edu.iq/article_29580_57096d5182a46997f01cd88011094093.pdf
2009-04-01
1026
1038
https://doi.org/10.30684/etj.27.6.1
Surface Roughness
EDM
MRR
REW
Wathik
I. Mahdi
1
AUTHOR
Maan
A. Tawfiq
2
AUTHOR
Shukry
H. Aghdeab
3
AUTHOR
ORIGINAL_ARTICLE
Laser sealing and thermal shock resistance of 6.5 wt% yttria Partially stabilized zirconia plasma sprayed layers
Laser sealing of zirconia-6.5 wt% yttria partially stabilized zirconia (YPSZ) plasmasprayed layers were examined for both plan views and transverse sections. Scanningelectron microscopy (SEM) has been used extensively to characterize the general featuresand microstructure of the layers under optimum laser processing conditions. The laser beamis shown to be effective in modified the plasma sprayed layers by sealing the porosity anddecrease the roughness. Thermal shock resistance test reveals that sealed layers have beenan excellent resistance to cracks formation parallel to the surface.
https://etj.uotechnology.edu.iq/article_29584_b3b26102c5cda0aaa913d197f01356c8.pdf
2009-04-01
1039
1048
10.30684/etj.27.6.2
Mohammed
Jasim Kadhim
1
AUTHOR
ORIGINAL_ARTICLE
Simulation of Active Magnetic Bearing Response based NNC
The present work is dealing with the modeling, investigations, and controlling, of a prototype radial magnetic bearing system. Considerations based on the 8 poles model with switched mode power supply. Investigations of radial forces in two axes model andperformance response are carried out through the intelligent controller system.Improving system response is achieved by using an efficient controller based Neural Network (NN) NARMA-L2 Controller together with the conventional PID controller. The response is presented for stand still and dynamic conditions using the implemented Simulink software. The results show that the NARMA-L2 is highly improved the dynamic response of the speeding up rotor in comparison with the conventional controller
https://etj.uotechnology.edu.iq/article_29586_775f17b0281bc06a1bbb762007a79f18.pdf
2009-04-01
1047
1063
10.30684/etj.27.6.3
Naseer
Qassim Hamoody
1
AUTHOR
Adil
Hameed Ahmad
2
AUTHOR
ORIGINAL_ARTICLE
HDNA : Heuristic DNA Computing Algorithm
The proposed system is based on embedded the heuristic search in DNA search algorithm so to make it more efficient and flexible. The HDNA system is constructed to improve the work of the DNA computing algorithm and enhance the measurement criteria of it by reducing the run time and the memory capacity as well as the number of generated random solutions (strands or states) that are needed to implement thecomputing algorithm. The experimental results appear that the HDNA using A* and Alpha-Beta is more efficient than using A* and Alpha-Beta each alone.
https://etj.uotechnology.edu.iq/article_29594_1ce12f9a3619fc9db3d9b27c5281b9c7.pdf
2009-04-01
1064
1073
10.30684/etj.27.6.4
DNA Computing
heuristic methods
algorithm
Alpha
Beta Algorithm
Ahmed
Tariq Sadiq
1
AUTHOR
Hasanen
Samir Abdullah
2
AUTHOR
ORIGINAL_ARTICLE
Adiabatic and Separated Flow of R-22 and R-407C in Capillary Tube
In this paper adiabatic flow in capillary tube is analyzed and modeled for R-22 andalternative R-407C. The equations of continuity, energy and pressure drop through acapillary tube are presented. A mathematical model of sub–cooled flow region andtwo–phase flow region is developed. The results of the calculation compared withexperimental data presented in the technical literature will be shown in the presentarticle in order to validate the model developed. This numerical model is capable ofproviding an effective means to analyze capillary tube performance to optimize andcontrol an R – 22 and R – 407C in an air – conditioning systems.
https://etj.uotechnology.edu.iq/article_29599_ee383c86ba2076571dd61648470c58a1.pdf
2009-04-01
1074
1082
10.30684/etj.27.6.5
Capillary tube
alternative refrigerant
adiabatic flow
Ahmed
Abdulnabi Imran
1
AUTHOR
ORIGINAL_ARTICLE
Study of The Optimization Condition Of Batch Sterilization Using Genetic Algorithm
The present work is designed to study the parameters interaction of sterilizationprocesses in batch bioreactors (fermentors of volume 120 liter with medium of 56784 kg).he parameters include the effects of sterilization temperatures (117-126oC), time ofheating, time of holding, and time of cooling on removal of all organisms, and degradationdegree of medium. Direct steam was used for heating at different temperatures rangedfrom 120oC to 180oC. The B.Stearothermophilus was selected as the present contaminants.Another bioreactor of volume (56828) liter was studied at 121oC for the same contaminantand compared with actual data.This study is achieved by designed procedure and simulation program useful forthe optimization of batch sterilization cycle in large-scale fermentors. The method ofoptimization used is Genetic Algorithm (GAs) which uses probability to find the optimumcondition for the sterilization cycle and to find Del factor; which is the reduction value ofinitial to final number of microorganisms, and then evaluate the cost which depend onamount of steam consumed in the sterilization processesGraphical relations was indicated that as fermentor size increase, the time ofheating also increase. For low temperature the time of holding was increased and for hightemperature the time of holding was decreased. Also these relations were investigated thebest conditions between holding time and Del factor for degradation at differenttemperatures.
https://etj.uotechnology.edu.iq/article_29640_69f2aadcac3a18eaea83e518f38ca55b.pdf
2009-04-01
1083
1092
10.30684/etj.27.6.6
Batch Sterilization Reactor
genetic algorithm
Thamer
J.Mohammed
1
Chemical Engineering Department, University of Technology /Baghdad
AUTHOR
Ittehad
F.Tobia
2
Chemical Engineering Department, University of Technology /Baghdad
AUTHOR
Salah
N.F.Al-Obaidi
3
Chemical Engineering Department, University of Technology/Baghdad
AUTHOR
ORIGINAL_ARTICLE
Syntheses, Characterization and Study of Use of Manganese (III) Schiff-Base Complex as Thermal Initiation in Radical Polymerization of Styrene
The new schiff base complex: Chloro- (bis (salicylaldehyde) ethylene diiminato)aqua manganese (III) is synthesized and characterized. It is used as thermal initiation inradical polymerization of styrene at 80 c◦ in dark without inhibition and retardationcomplication, and the rate of polymerization is directly proportional to the squre root ofinitiator concentration [I]1/2 . gravimetry technique is used for deteremination of the ratepolymerization, and viscometery is used for determination of average of polymerization.The uv- visble spectrophotometry is used to determine the rate constant of initiatordecomposition (ka). The value of the kinetic parameter ratio kp / kt1/2 (Where kp & ktare the rate constants, propagation and termination respectively).
https://etj.uotechnology.edu.iq/article_30092_1919ac8d3666d596e0ff894f8448b741.pdf
2009-04-01
1093
1107
10.30684/etj.27.6.7
Thermal Initiation
polystyrene
Ahlam
Said Maroof
1
AUTHOR
ORIGINAL_ARTICLE
Simulation Study 0f 802.11b DCF Using OPNET Simulator
A simulation study of an IEEE 802.11b which is the most important standard forwireless local area networks was presented in this paper. The simulation is conducted usingOPNET IT Guru Academic Edition 9.1. Wireless network performance depends mainly onthe end to end throughput and average delay. Different applications place differentrequirements on the network. Thus, it is necessary to evaluate and analysis the performanceof IEEE 802.11b WLAN system under the fundamental access mechanism for mediumaccess control (MAC) called distributed coordination function (DCF).This can achieve bystudying the impact of parameters such as Request to Send/ Clear to Send (RTS/CTS),Fragmentation Threshold (FTS) and discuss the best configurations and parameters value incorrespondence to network load and topology to get best performance which is the mainobjective of this paper.
https://etj.uotechnology.edu.iq/article_30094_4c5531babbc670ac03cfcb81bc32260c.pdf
2009-04-01
1108
1117
10.30684/etj.27.6.8
Wireless LAN
IEEE
Distributed Coordination Function DCF
Opnet Simulator
Mohammad
Hussian Ali
1
AUTHOR
Manal
Kadhim Odah
2
AUTHOR
ORIGINAL_ARTICLE
Numerical Simulation of a Two-Dimension Ramp Inlet Flow Field
The Two-dimension ramp inlet flow field was studied with typical mode operations.Euler equations were used for solution with no special treatment required. In this work asolution algorithm based on finite difference MacCormack’s technique was developed tosolve mixed subsonic-supersonic flow problem through the external shock diffusers(ramp inlet) and it is found to be converge for supercritical and critical inlet operation.
https://etj.uotechnology.edu.iq/article_30096_80982a2c1944a8d49a71155e7aa8eb00.pdf
2009-04-01
1118
1126
10.30684/etj.27.6.9
CFD
Supersonic
Ramp Inlet
Shock Capture
MacCormack
Jalal
M. Jalil
1
AUTHOR
Ahmed
F. Kridy
2
AUTHOR
ORIGINAL_ARTICLE
A Secure Mobile Banking Using Kerberos Protocol
Because the network is an open environment, a lot of care must be taken whentransferring sensitive information especially when related with financial data. This dependson the principals to be trusted which is a problematic and since the first step in networksecurity is the authentication, this paper presents a proposed modal for secure mobilebanking (m-banking) applications using Kerberos (the network authentication protocol).The aim of this paper is to establish a secure communication between the clients andmobile-bank application server in which they can use their mobile phone to securely accesstheir bank accounts, make and receive payments, and check their balances.The integration of smart card into classic Kerberos enhances the security for clientauthentication by storing the cryptographic keys and perform dual factor authentication.Other enhancement to Kerberos is the PKINIT in which the shared key is mapped withpublic- private key. To build a robust client authentication the client uses his/her mobilephone to author Kerberos's messages, process the replay and establish securecommunication with the application server.
https://etj.uotechnology.edu.iq/article_30101_7bbad0a9313c3f6c155d04bd184bc770.pdf
2009-04-01
1127
1133
10.30684/etj.27.6.10
authentication
bank
mobile
Kerberos
PKINIT
smart card
ClientServer
shared key
public
private key
Cryptographic
applet
Mohammad
N. Abdullah
1
AUTHOR
May
T. Abdul-Hadi
2
AUTHOR
ORIGINAL_ARTICLE
The Effect of Surfactant Concentration on the Rate of CO2 Absorption by Carbonate Solution in Packed Tower
Absorption of carbon dioxide from gaseous mixture (carbon dioxide, air) wasstudied by using Carbonate Solution (Na2CO3) in a counter-current packed column (7.5 cmid, 1.70 m height), packed with glass rashing rings of 1.8 cm i.d to a depth of 1.1 m.The effect of Surfactant concentration (dodecyl benzene sulfuric acid sodium(DBS))(0.5, 1.5, 2.5gm/lit.), gas mass flux (0.05, 0.075, 0.1 kg/m2.sec) and liquid mass flux(kg/m2.sec) on the absorption rate of carbon dioxide and mass transfer coefficient wasstudied at constant carbonate concentration (0.3 kmol/m3), inlet carbon dioxideconcentration(0.08, Y2=0.086 mol CO2/mol air), ambient temperature and atmosphericpressure. The results show that the absorption rate tends to increase with increasing gas andliquid flow rate. Mass transfer coefficient (KG.a) increases with increasing liquid flow rateand slightly change with increasing gas flow rate. Increasing surfactant concentration(decreasing surface tension) leads to decrease the absorption rate and mass transfercoefficient.
https://etj.uotechnology.edu.iq/article_30104_376e6aec5e894d1737b7d73f84d010d3.pdf
2009-04-01
1134
1142
10.30684/etj.27.6.11
surfactant
Absorption with chemical reaction
carbon dioxide
Carbonate Solution
Mass transfer coefficient
Fadil
H. Faraj
1
AUTHOR
Alyaa
K. Mageed
2
AUTHOR
ORIGINAL_ARTICLE
Using of Taguchi Method to Optimize the Casting of Al–Si /Al2O3 Composites
Taguchi method is a problem – solving tool which can improve the performanceof the product, process design and system. This method combines the experimental andanalytical concepts to determine the most influential parameter on the result response forthe significant improvement in the overall performance. In this research Al–Si /Al2O3composites was prepared by vortex technique using three different parameters, stirringtime, stirring speed, and volume fraction of the reinforcement particles. A tensile andhardness tests were done for the resulted castings. The primary objective is to useTaguchi method for predicting the better parameters that give the highest tensile strengthand hardness to the castings, and then preparing composites at these parameters andcomparing them with the randomly used once. The experimental and analytical resultsshowed that the Taguchi method was successful in predicting the parameters that givethe highest properties and the volume fraction was the most influential parameter on thetensile strength and hardness results of castings
https://etj.uotechnology.edu.iq/article_30107_f56c137431a2841021389f79953711e3.pdf
2009-04-01
1143
1150
10.30684/etj.27.6.12
composites
Taguchi method
Tensile Strength
Hardness
Osama
S. Muhammed
1
AUTHOR
Haitham
R. Saleh
2
AUTHOR
Hussam
L. Alwan
3
AUTHOR
ORIGINAL_ARTICLE
Effect of Laser Surface Treatment on Wear Resistance of 100Cr6 Steel
The effect of laser surface heat treatment on wear resistance of 100Cr6 steel wasinvestigated. In this work, 100Cr6 steel which is widely used in many industrial of automobileshardened by using Nd: glass laser (l=1.060mm, t=300ms). Three different laser energies have beenused to perform hardening (0.3, 0.58 and 0.93 Joule). A pin-on-disc technique has been used toevaluate wear rate of the specimens as-received and specimens treated by Nd: glass laser atdifferent applied loads and different sliding speeds with 420 r.p.m and 45 HRC of rotatingdisc. The results show that the wear rate increases with increasing applied load and decreases withincreasing sliding speed, wear rate for laser energy 0.93 J less than another energies 0.3 and 0.5 J.Also the microhardness decreases with increasing in depth of hardening, and the microhardnessfor laser energy 0.93 J more than another energies for the same depth.
https://etj.uotechnology.edu.iq/article_30112_22567166e3a51bb810f161973dd4fcf8.pdf
2009-04-01
1151
1161
https://doi.org/10.30684/etj.27.6.13
Wear Resistance
glass laser
Microhardness
Khansaa
Dawood Salman
1
AUTHOR
ORIGINAL_ARTICLE
Video Image for Security System by Using Chaotic Oscillator for Segmentation
There are wide variety of mechanisms available for performing the authenticationfunction. One of them is by using video film to monitor important places. In such systemsthe important task is recognizing human faces which need good segmentation and highfeature extraction. In traditional technique the segmentation can be performed by regiongrowing and shrinking, clustering method, and boundary detection which all take imagepixel by pixel and compare each with neighbors to get the similarity. Chaotic oscillatordepends on synchronization concept between points to determine the active points whichconstruct similar region determining the object. Then RGB color space is used to determineskin color pixel. Skin color model aids the process of separating the face from the scene dueto its skin color. After isolating the human face image which contains many features (eye,eyebrow, nose, etc...) they identify the person. Chaotic oscillator is used to extract theimportant features by removing any point that is not synchronized with its neighbors andgives new image which contains only the main face features and then compare this imagewith stored image in Database of authorized person and make decision on if (he/she) is anauthenticated image or not.
https://etj.uotechnology.edu.iq/article_30116_c029c413d8cdfb2ced833485556db578.pdf
2009-04-01
1162
1173
10.30684/etj.27.6.14
Chaotic Oscillator Segmentation
Face detection
Skin color segmentation
Emad
Kadum Jabbar Alfatly
1
AUTHOR
Nuha
Jameel Ibrahim
2
AUTHOR
ORIGINAL_ARTICLE
Correlation between Thickness, Grain Size and Optical Band Gap of CdI2 Film
Structural and optical property was studied as a function of film thickness forthermally evaporated CdI2 films. Stoichiometric films (up to 250 nm thickness) showinghexagonal structure, and good c-axis alignment normal to glass substrate plane. Theoptical absorption data indicate an allowed direct inter – band transition near theabsorption edge with optical energy gap varies continuously from 2.9 eV to 3.6 eV.Partof the optical data was fitted to an indirect type transition to determine the indirect opticalenergy gap which also varies continuously from 2.2 eV to 3.1 eV . Both energy gapsshow thickness dependences, which can be explained qualitatively by a thicknessdependence of the grain size through the decreasing of the grain boundary barrier heightwith grain size.
https://etj.uotechnology.edu.iq/article_30118_6c68ecbd01427b2ffc56b683573fd09f.pdf
2009-04-01
1174
1183
10.30684/etj.27.6.15
CdI
Optical Band
gap
Modaffer
A. Mohammed
1
AUTHOR
ORIGINAL_ARTICLE
Data Hiding in Sound Using Time Modulation of Unvoiced Blocks
This paper is concerned with hiding secret data in audio media file (.WAV). Whenperforming data hiding in audio, one must exploit the weaknesses of Human Auditory System(HAS), while at the same time being a ware of the extreme sensitivity of this system. Thishiding method is oriented to embed the secret data such that it is capable of surviving againstmodifications produced by MP3 compression standard. Statistical and analyticalinvestigations are performed to assess the variations which may occur in the WAVE audiowhen it is subjected to MP3 compression. Features of speech signal are exploited (Voiced-Unvoiced segments) for embedding the secret data. Hiding is attempt by shortening orelongating the unvoiced blocks of audio file (cover) data. To support the immunity of theproposed hiding system, an encryption method is added to the proposed hiding system.
https://etj.uotechnology.edu.iq/article_30121_7c7d03a3ef5c049dd8c4eb1e492b94f0.pdf
2009-04-01
1184
1196
10.30684/etj.27.6.16
Audio Hiding
Speech Analysis methods
Audio compression
Hilal
H. Saleh
1
AUTHOR
Loay
A. Jorj
2
AUTHOR
Nidaa
F.Hassan
3
AUTHOR
ORIGINAL_ARTICLE
Studing The Mechanical Properties And Morphology of Ternary Blends Of Polyethylene
The mechanical properties and the morphology of the ternary blend ofLDPE/LLDPE/HDPE were studied.In the present work LDPE was mixed with equal amount of LLDPE and differentwt% of HDPE (0, 10, 20 and 30 %) using the two roll mills. The mechanical propertiesand the morphology were specified by measuring the (tensile, hardness, impactproperties) for the former, and photomicrograph for the later. From the tensile testresults it was found that the tensile strength at break of the ternary blend increased withincreasing the HDPE contain also the increases of wt% HDPE leads to decrease theelongation at break. For the hardness test it was found that the shore hardness of theternary blends increased with the increasing the HDPE contain .On the other hand theimpact test carried out also and it was found that the addition of HDPE leads todecrease the impact strength . Nevertheless, optical micrograph results that the HDPEserves as a compatabilizing agent for immiscible LDPE/LLDPE
https://etj.uotechnology.edu.iq/article_30126_a90125c0674c1b709ea71ce108cc7c26.pdf
2009-04-01
1197
1205
10.30684/etj.27.6.17
ternary blends LDPE
Mechanical properties
Nabeela
A. Mohammed
1
AUTHOR
ORIGINAL_ARTICLE
A Data Base for Self-Compacting Concrete in Iraq
Self-Compacting Concrete is considered one of most remarkable developments inconcrete technology. It is a new type of high performance concrete with the ability offlowing under its own weight and without the need of vibrations. Recently, a great nativeinterest had been derived towards self-compacting concrete.This work aims to present a summary study about properties of fresh selfcompactingconcrete depending on the results obtained by some native researches, thusfocusing on the main common features between their results. It had been focused on theeffect of type and proportions of constituent materials incorporated in producing selfcompactingconcrete. This considered the most influential factors in controlling itsproperties.
https://etj.uotechnology.edu.iq/article_30135_d033784e8c95a7821ce93902d73c2d2d.pdf
2009-04-01
1206
1218
10.30684/etj.27.6.18
Iraqi self
Compacting Concrete
properties of fresh self
materials of self
Shakir
A. Al-Mishhadani
1
AUTHOR
Mays
F. Al-Rubaie
2
AUTHOR
ORIGINAL_ARTICLE
Behavior of Short Reinforced Porcelinite Concrete Columns Under Concentric Loads
This study presents on experimental method to investigate the behavior ofreinforced porcelinite concrete columns subjected to concentric load. The experimentalwork includes investigation of ten lightweight concrete columns with square crosssection 190×190mm and 1000mm in length subjected to concentric load to assess theeffect of the amount of longitudinal steel reinforcement, lateral tie reinforcement andgrade of concrete. From the experimental observation it was found that the porceliniteaggregate is a good structural material to produce lightweight concrete columns. It isnoted from tested columns that keeping the amount of the longitudinal steel ratioconstant, the increase in the amount of transverse steel to about four times (bydecreasing the spacing to about a quarter according to the ACI-Code (318M-05)) gave asignificant influence on column post-cracking behavior. The improvements in thecolumn due to higher value of confinement include: (i) less brittle behavior; (ii)significantly less damage to the concrete core; (iii) 12% increase in column loadcarrying capacity. Also, A modified formula for column capacity is proposed to takeinto account the influence of spacing of ties (effect of confinement).
https://etj.uotechnology.edu.iq/article_30161_7621283557de2e0372bc18594ada6375.pdf
2009-04-01
1219
1233
10.30684/etj.27.6.19
Porcelinite
columns
Kaiss
F. Sarsam
1
AUTHOR
Ihsan
A. S. Al-Shaarbaf
2
AUTHOR
Mustafa
S. Shuber
3
AUTHOR