Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Two


Experimental Analysis of Several Variables Influencing Formed Thickness in Two-Point Incremental Forming Process

A.K. Ibrahim; W.K. Hamdan

Engineering and Technology Journal, 2017, Volume 35, Issue 7, Pages 749-755

In the current paper, an experimental analysis on Al-sheet (AA 1050) with thickness 0.9 mm to reveal the effect of relevant forming factors on the formed thickness in two-point incremental forming (TPIF) process has been conducted. The formed thickness of pyramid-like shapes was analyzed by studying seven variables: die geometry, tool diameter, tool path, stepover, tool shape, lubricant and slope angle. The proposed analysis utilizes Box-Behnken design of experiment (BBD), main effects plot (MEP) and analysis of variance (ANOVA) for sake of studying the influences of the seven forming factors on the resulted thickness. The results of these analyses have indicated that the most significant factor affecting the formed thickness is the die geometry followed by tool shape, lubricant and stepover respectively for both slope angles of the pyramid. In addition, it has been found that the other variables have also significant effects on the formed thickness at both slopes of the pyramids produced.

Two-Stage and Walsh Interleavers for Interleave Division Multiple Access Systems

Muayad Sadik Croock

Engineering and Technology Journal, 2014, Volume 32, Issue 1, Pages 273-285

Interleavers are essential system components for interleave division multiple access (IDMA). In this paper, two-stage interleavers are proposed based on two optimization criteria combines minimum spreading distance with regular permutation and randomization properties to have almost the same advantages of the random distribution, and yet guaranties an enlarged minimum spread distance. Simulation
results show sufficiently good performance with much less resource consumption compared to multiple random interleavers. The proposed method may also find other application areas such as multi-dimensional concatenated codes. In addition, an efficient and simple procedure is proposed to generate orthogonal interleavers by using the well-known Walsh-Hadamard transform.

Ear Recognition by Using Self Organizing Feature Map

Suad K. Mohammad

Engineering and Technology Journal, 2013, Volume 31, Issue 10, Pages 2000-2013

A wide variety of systems requires reliable personal recognition schemes to either confirm or determine the identity of an individual requesting their services. The purpose of such schemes is to ensure that the rendered services are accessed only by a legitimate user and no one else.
The aim of the work presented within this paper is to develop an optimum image compression system using haar wavelet transform and a neural network. In this paper we have developed and illustrated a recognition system for human ears using a Kohonen self-organizing map (SOM) or Self-Organizing Feature Map (SOFM) based retrieval system. SOM has good feature extracting property due to its topological ordering. The ear Analytics results for the 4 images of database reflect that the ear recognition using one of the neural network algorithms SOM for 4 persons. MATLAB programs were used to complete this work.

Unscented Kalman Estimator for Estimating the State of Two-phase Permanent Magnet Synchronous Motor

Ayad Qasim Hussein

Engineering and Technology Journal, 2010, Volume 28, Issue 15, Pages 5071-5078

This paper presents the unscented Kalman filters (UKF) for estimating the states (winding currents, rotor speed and rotor angular position) of two-phase Permanent Magnet Synchronous Motor (PMSM). The UKF is based on firstly specifying a minimal set of carefully chosen sample points. These sample points completely capture the true mean and covariance of the Gaussian Random Variable (GRV), and when propagated through the true nonlinear system (motor model), capture the posterior mean and covariance accurately to the second order (Taylor series expansion). The results showed that the UK estimator could successively estimate the states of PMSM without need any Jacobian matrix.

Logical Twofold Integral

Jabbar Abbas Ghafil

Engineering and Technology Journal, 2010, Volume 28, Issue 3, Pages 477-483

The aim of this paper is to present a new framework for studying capacities and
twofold integral from a point of view of two-valued logic. In this framework, we
propose equivalent definitions of capacities and twofold integral that may be more
easily interpretable. First, we define a logical capacity, then, we propose definition of
logical twofold integral with respect to logical capacities based on the two-valued
logic.

Effect of Crude Oil-Water Two-Phase Flow on Pump Performance

Banipal N. Yaqob; Ihsan F. Abbas

Engineering and Technology Journal, 2009, Volume 27, Issue 9, Pages 1766-1774

An experimental study of pump performance (i.e. head, discharge, power, etc.) was achieved by using a centrifugal pump with crude oil-water two-phase flow. The crude oil used was from Sherao oil field in Kirkuk (Iraq) with a density of 838 kg/m3, dynamic viscosity of 6.0 cP and surface tension of 0.027 N/m at a temperature of 25oC. A centrifugal pump was used with straight impeller and one suction line and one
discharge line. The results show that the pump head and the discharge of two-phase flow decrease as oil volume fraction increased, and the power of the pump increase as oil volume fraction increased

State Estimation of Two-Phase Permanent Magnet Synchronous Motor

Amjed J. Hamidi; Ahmed Alaa Ogla; Yaser Nabeel Ibrahem

Engineering and Technology Journal, 2009, Volume 27, Issue 7, Pages 1435-1443

The goal of this paper is to estimate the states of two-phase permanent magnet synchronous
motor (PMSM). The system is highly nonlinear and one therefore cannot directly use any linear
system tools for estimation. However, if one can linearize the system around a nominal
(possibly time-varying) operating point then linear system tools could be used for control and
estimation. Firstly, the error covariance matrices of measurement and process would be derived
when the system inputs and outputs are subjected to uncertain variations. Then, the corruptednoise
nonlinear model of the system will be discretized and extended to be suitable for applying
standard discrete Kalman filter (KF) for state estimation purpose. The entire state estimated
system has been modeled using MATLAB/SIMULINK blocks. The state estimation algorithm
and the motor discretized model are coded inside special S-functions of m-file type.

Numerical Study of Forced Convection in Wavy and Diverged-Converged Ducts

Anmar M. Basheer; Sattar J. Habeeb; Waheed S. Mohamad; Qutaiba G. Majeed; Mohammed Y. Fattah; Jawad K.Oleiwi; Mohammed S. Hamza; Mayyadah Sh. Abed; Amjed J. Hamidi; Ahmed Alaa Ogla; Yaser Nabeel Ibrahem

Engineering and Technology Journal, 2009, Volume 27, Issue 7, Pages 1385-1403

A three-dimensional study of developing fluid flow and heat transfer through
wavy and diverged-converged ducts were studied numerically for a Prandlt number 0.7
and 5.85 and compared with flow through corresponding straight duct. The Navier-
Stokes and energy equations are solved by using control finite volume method.
Development of the Nusselt number in wavy and diverged-converged ducts are
presented for different flow rates (50

Keywords

forced convection
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numerical study
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wavy duct
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diverged-converged duct

Hydrodynamics Of Two Phase Flow For Coalescing And Non Coalescing Systems

Thamer J. Mohammed; Mohammed F. Abid; Hiba M. Abdullah

Engineering and Technology Journal, 2009, Volume 27, Issue 3, Pages 481-495

This experimental study is aimed at investigating the effect of superficial gas
velocity, liquid phase properties and gas distribution on gas holdup, bubble
characteristics and drag coefficient in two-phase bubble column. Various liquids
covering a sufficiently broad range of viscosity and surface tension values were
employed, while the gas phase was atmospheric air. Aqueous glycerine solutions were
used to simulate the behavior of coalescing viscous liquids whereas aqueous alcohol
solutions were used to simulate the behavior of non-coalescing organic liquids. The
experimental results obtained with two different types of gas distributor in the
coalescence solutions and in non coalescence solutions were compared with data on
standard air–water system. A computerized conductivity probe system and high speed
digital camera were used for the systematic measurements of bubble size, velocity and
gas hold-up. Correlations based on dimensionless groups were proposed for the
prediction of gas holdup and drag coefficient in the homogeneous flow regime.