University of Technology-Iraq
Engineering and Technology Journal
1681-6900
2412-0758
25
1
2007
01
25
Effect of Possivity on The Mechanical Machined Surfaces
1
8
EN
10.30684/etj.25.1.1
The object of this research is to study the passivity of parts surfaces produced from steel and its alloy. The study steps include, preparing specimens of low carbon steel ,with (dimension (20*30 cm) and its thickness (2 mm)). The specimens were immersed in a solution containing the following: <br /><br /> Caustic soda.<br />2. Sodium nitrate (1%)<br />3. Sodium cyanide (1.5%)<br />4. Sodium chromate (1.5%)<br />The influence of caustic soda concentrations, temperature of solution and<br />time of immersing on corrosion of specimens were studied, from which it has been shown that it was possible to obtain the best passive surfaces of the parts with caustic soda concentration (5%), time of immersing specimens (20 min) and temperature of solution (45oC). <br />The results and conclusions obtained from this study were applied to treating surfaces of some machining parts in Nasser State Company/central tool room plan. The results show noticeable improvement in the corrosion resistance of the metal used for more than 70 days.
https://etj.uotechnology.edu.iq/article_181441.html
https://etj.uotechnology.edu.iq/article_181441_de6de54313817396d2fc22c69a39be77.pdf
University of Technology-Iraq
Engineering and Technology Journal
1681-6900
2412-0758
25
1
2007
01
25
Study of 2-D Laminar Flow In A pipe With A sudden Contraction of Cross Sectional Area
1
8
EN
Khudheyer
S.
Mushate
10.30684/etj.25.1.2
The paper presents a detailed numerical study of laminar flow in a pipe with sudden contraction in its cross sectional area. A computer program has been developed to analyze the laminar flow field in the pipe-sudden contraction configuration. The Navier-Stockes and energy equations are solved using primitive variables with a finite -volume (FV) solution method. The study was carried out for a Reynolds numbers range up to 750 and for different contraction ratios (d/D). The results demonstrate that the separation regions increase with the increase of Reynolds numbers. And the contraction ratio (d/D) has significant effect on these regions.
https://etj.uotechnology.edu.iq/article_181442.html
https://etj.uotechnology.edu.iq/article_181442_175cbc5f267cd7dac6b2ef1290474d06.pdf
University of Technology-Iraq
Engineering and Technology Journal
1681-6900
2412-0758
25
1
2007
01
25
Design Effect of The Welded Joints On Fatigue Strength For Low Carbon Steel Metal (ST- 52- 3)
9
22
EN
10.30684/etj.25.1.3
The aim of the present research is to evaluate the best welded joints of types (V, VV, U,UU) and comparing them with the base metal type (ST-52-3) which is used in awide range at industry and then to show the effect of these types on the fatigue limit under the reverse bending loads effect. The results of the experimental tests for these four types of the welded joints show that the fatigue strength of the welded specimens is very nearly to the fatigue strength of the base metal and more precisely and that the difference between these welded joints and the base metal is (3.7 %, 4.2 %,4.5 %, and 5 % ) and by quality(better) arrangement will be (U,V,VV, and UU) respectively.
https://etj.uotechnology.edu.iq/article_181443.html
https://etj.uotechnology.edu.iq/article_181443_afe6b6d7e795c175f6191bf6b4b93c73.pdf
University of Technology-Iraq
Engineering and Technology Journal
1681-6900
2412-0758
25
1
2007
01
25
Parametric Study On The Effect Of The Fiber Reinforced Polymer(FRP) Pad On The Stress Intensity Factor of A Cracked Pipe
9
24
EN
Wail e
N.
Al-Rifai
Waleed
Khalil
Ahmed
10.30684/etj.25.1.4
In this paper the effect of using FRP bonded pad to reinforce damaged pipes subjected to internal pressure is investigated. Outer Longitudinal edge crack was simulated by using standard finite element method as a powerful tool for the numerical solution of a wide range of engineering problems. Cracks in the present study are investigated by using linear elastic fracture mechanics in order to calculate the stress intensity factor SIF. Mode I SIF was calculated by means of using standard FE program ANSYS5.4 and the element used was 8-node quadrilateral isoparametric element .A parametric study was done to investigate the effect of the pad width W, thickness H and the volume fraction Vf of the composite pad on the SIF of the cracked pipe .It was found that by using FRP pad to reinforce the cracked pipes , the SIF reduces in the vicinity of the crack tip, and the fiber volume fraction of the pad has a great influence on the SIF.
https://etj.uotechnology.edu.iq/article_181444.html
https://etj.uotechnology.edu.iq/article_181444_b4d7b0908b0e4563069bfe80c4f61d50.pdf
University of Technology-Iraq
Engineering and Technology Journal
1681-6900
2412-0758
25
1
2007
01
25
Thermal Initiation of Methylmethacrylate by Methoxy–oxobis [N-(4-bromophenyl) Salicylideneiminato] Vanadium (V)
26
36
EN
Najat
J.
Saleh
10.30684/etj.25.1.5
Methoxy – oxo - bis [N - (4-bromophenyl ) Salicylidene – iminato ] Vanadium (V) : [VO (Br C6 H4 N : C H O C6 H4 )2 OCH3 can initiate methylmethacrylate thermally at 80°C . Under the experimental conditions employed, no retardation or inhibition is observed. The order with respect to the initiator concentration is (0.5), while the order with respect to monomer concentration is (1.8) which gives an indication that the rate of initiation is dependent on monomer concentration.<br />Spectroscopic studies suggest that during the thermal polymerization a reduction in the oxidation state of vanadium occurs with heterolytic scission of the V- OCH3 bond and this might be induced by MMA molecule which forms intermediate complex between VOL2 OCH3 and methyl methacrylate monomer before the formation of the primary radical responsible for the initiation process.<br />Activation energies of polymerization as well as initiation processes in the present system were also determined . The tacticity of polymer produced is examined.<br />According to the experimental results obtained a mechanism of thermal initiation reaction is proposed.
https://etj.uotechnology.edu.iq/article_181445.html
https://etj.uotechnology.edu.iq/article_181445_adc95a0588e7eb31bd167bd2ab5dcb96.pdf
University of Technology-Iraq
Engineering and Technology Journal
1681-6900
2412-0758
25
1
2007
01
25
Finite Element Analysis of the Rake Angle Effects on Residual Stresses in a Machined Layer
36
48
EN
Maan
Aabid
Tawfiq
70057@uotechnology.edu.iq.
10.30684/etj.25.1.6
In this paper, a plane strain Finite Element Method is developed and applied to model and simulate the orthogonal metal cutting of (AISI 1045 St) with continuous chip formation. Seven sets of simulation results for cutting with rake angles (-15o, -10o, -5o, 0o, 5o, 10 o and 15o), are summarized and compared to analyze their effects in the cutting process in steady state condition. Simulation results of the residual stresses below the machined layer are presented and compared with other papers in the literature and showed good agreement. <br />Simulation results offer an insight into residual stresses through different values of rake angles. Based on simulation results, characteristics of residual stress distribution can be controlled by optimizing the rake angle. The simulated results show that for positive rake angles and position, the zero of maximum effective stress is found to be at (0.04) mm beneath the work piece surface, while for negative rake angles, the position of maximum effective stress is changed to be directly on the workpiece surface.
https://etj.uotechnology.edu.iq/article_181446.html
https://etj.uotechnology.edu.iq/article_181446_3c61619a5d7f79aeb6b58d3a6cdd0934.pdf
University of Technology-Iraq
Engineering and Technology Journal
1681-6900
2412-0758
25
1
2007
01
25
Electrical and Photovoltaic Properties of In-pSi Contact
49
55
EN
Khalid
Z.
Yahya
10.30684/etj.25.1.7
In the present work, the electrical and photovoltaic properties of In-pSi contact were investigated for the first time. Two creditable methods were used to determine the value of barrier height for this contact. Experimental results shows a reasonable agreement with the simple Schottcky-Mott theory. The contact shows good response to white light when it works under bias condition. Peak response of 0.22 A/W at 850 nm wavelength was registered.
In/Si contact,photovoltaic,BARRIER HEIGHT,responsivity
https://etj.uotechnology.edu.iq/article_181447.html
https://etj.uotechnology.edu.iq/article_181447_e922e90c296e5664b1415d62c354ba99.pdf
University of Technology-Iraq
Engineering and Technology Journal
1681-6900
2412-0758
25
1
2007
01
25
NC Roughing Maching of Cavities Defined by Surface of Revolution Approach
56
77
EN
Wissam
K.
Hamdan
10.30684/etj.25.1.8
In the NC roughing phase of cavities, process planar needs to find the machining layers as well as the feasible cutters for these layers. This Paper deals with the issues of Cavity Construction based on Surface of revolution technique using cubic Bezier curve as a generator curve. First the generator curve is constructed in x-z plane then allowing it to revolve through 360o about z-axis in order to generate the required surface cavity. A strategy of Maximum (critical cutter size) and Machining layers determination is also introduced in this paper. Numerical iteration is used for this purpose using MATLAB programming system to reduce the computational time. A comparison is made between different machining cavities critical cutter size and using cutters smaller than the critical size showing a wide reduction in the length of circular tool path(s) (CL) and the volume of removed metal (VRM).Numerical examples are presented to illustrate the proposed system.
NC Roughing,VRM,CL,Cutter Selection,Inverse Point Interpolation
https://etj.uotechnology.edu.iq/article_181448.html
https://etj.uotechnology.edu.iq/article_181448_f0a38b48ae1e5a4d715b8c50915fd81e.pdf
University of Technology-Iraq
Engineering and Technology Journal
1681-6900
2412-0758
25
1
2007
01
25
Mixed Convection in The Entry Region of a Vertical Annulus with a Constant Temperature Rotating Inner Cylinder
78
96
EN
Akeel
A.
Mohammed
akeel.a.mohammed@nahrainuniv.edu.iq
10.30684/etj.25.1.9
Laminar air flow combined convection in a vertical annulus with a constant temperature rotating inner cylinder is treated on the basis of a developing flow model, and the basic differential equations are rewritten in finite difference form and solved by a computer program in Fortran. Investigation covers the ranges of 0.2≤N≤0.9 , –300≤Gr/Re≤800 and 0.2≤Re2/Ta≤1000. In addition to the usual heat transfer calculations, this enables the developing velocity and temperature fields to be studied. On the other hand , the effect of a superimposed aiding or opposing natural convection on the developing tangential velocity profile is also investigated.
https://etj.uotechnology.edu.iq/article_181450.html
https://etj.uotechnology.edu.iq/article_181450_c55b54b398f98e0fd30a246b836e26da.pdf
University of Technology-Iraq
Engineering and Technology Journal
1681-6900
2412-0758
25
1
2007
01
25
Effect Of Solid Catalyst On Bubble Rise Velocity And Gas- Drift Flux In Three-Phase-Columns
97
102
EN
Kamal
Mohammad
Ahmad
10.30684/etj.25.1.10
The bubble rise velocity and drift flux were measured in 0.051 m i.d glass column with ethanol as the liquid phase, cobalt catalyst as the solid phase in concentration varying from (1.0 to 0.4) vol % in three phase column. <br />Gas superficial velocity (Ug) was varied from (0.02 to 0.1) m/s. <br />Experimental results show that the gas-holdup and gas flux decreases with the increasing of catalyst concentration but increasing bubble rise velocity.
slurries,Gas holdup,Bubble column,Mass transfer coefficient
https://etj.uotechnology.edu.iq/article_181451.html
https://etj.uotechnology.edu.iq/article_181451_222e8e6f0683bc74741a61de9c56a61c.pdf
University of Technology-Iraq
Engineering and Technology Journal
1681-6900
2412-0758
25
1
2007
01
25
Early Manufacturing Cost Estimate For Mechanical Parts
103
116
EN
Khalid
Karam
Abd
10.30684/etj.25.1.11
In manufacturing environment cost estimates process is made in all stages of product development from research to final product. Good estimating techniques and procedures are necessary for each manufacturing stage. When properly implemented, these techniques produce acceptable operational estimates that are useful to management for decision-making. <br />In this research, an algorithm is developed to build system is called FBMCE (Feature-Based Manufacturing Cost Estimate) to incorporate making decisions integrating design, process planning and manufacturing for cost estimate purposes. The FBMCE system has been tested on product (Shaft 8E - 200) in State Company for Electrical Industries and showed promising results
Cost Estimation,feature-based,Process Planning
https://etj.uotechnology.edu.iq/article_181452.html
https://etj.uotechnology.edu.iq/article_181452_ea63091cec90e6da4e4baaa64b99d0be.pdf
University of Technology-Iraq
Engineering and Technology Journal
1681-6900
2412-0758
25
1
2007
01
25
Grillage Analysis of Plates for Vibration and Stability
117
131
EN
Sabih
Z.
Al-Sarraf
Ammar
A.
Ali
10.30684/etj.25.1.12
This study deals with the problem of approximating the dynamic and static analysis of plates by using equivalent grid-framework model. The emphasis, for plate analysis, is on the stability and vibration analysis. Numerical results are presented for many example problems, and they indicate that the adopted method is reasonably accurate. For vibration analysis of plates using beam-column analogy the percentage of error is depends on mesh size.
grillage analogy,plate analysis,vibration and stability
https://etj.uotechnology.edu.iq/article_181453.html
https://etj.uotechnology.edu.iq/article_181453_41affffeb225b4d90b6f457c5e8e9328.pdf