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Iraqi Journal of Applied Physics

المجلة العراقية للفيزياء التطبيقية

ISSN: 18132065 23091673
Publisher: iraqi society for alternative and renewable energy sources and techniques
Faculty:
Language: English

This journal is Open Access

About

The Iraqi Journal of Applied Physics (IJAP) is a peer reviewed journal of high quality devoted to the publication of original research papers from applied physics and their broad range of applications. IJAP publishes quality original research papers, comprehensive review articles, survey articles, book reviews, dissertation abstracts in physics and its applications in the broadest sense. It is intended that the journal may act as an interdisciplinary forum for Physics and its applications. Innovative applications and material that brings together diverse areas of Physics are particularly welcome. Review articles in selected areas are published from time to time. It aims to disseminate knowledge; provide a learned reference in the field; and establish channels of communication between academic and research experts, policy makers and executives in industry, commerce and investment institutions. IJAP is a quarterly specialized periodical dedicated to publishing original papers, letters and reviews in: Applied & Nonlinear Optics, Applied Mechanics & Thermodynamics, Digital & Optical Communications, Electronic Materials & Devices, Laser Physics & Applications, Plasma Physics & Applications, Quantum Physics & Spectroscopy, Semiconductors & Optoelectronics, Solid State Physics & Applications, Alternative and Renewable Energy, Computers Networks and Applications.

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Contact info

P. O. Box 55259,
Baghdad 12001,
Iraq
Website: www.iraqiphysicsjournal.com
Email: admin@iraqiphysicsjournal.com
Email: editor_ijap@yahoo.co.uk

Table of content: 2009 volume:5 issue:1

Article
Key Principle of Electroluminescent Polymers (Review Article)

Authors: D.T. Chou
Pages: 3-5
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Abstract

Recent progress made in the field of electroluminescent (EL) polymers is reviewed in this paper. Polymer electroluminescence is an area of growing interest due to its appeal in a scientific sense and for its potential in applications for low-cost, easily constructible light emitting diodes (LEDs) and in large flat displays. A brief overview of device construction is presented followed by a review of new developments in methods for fabrication and synthesis of EL polymer devices. Characteristics of EL polymer devices are considered with the mechanisms used to generate them.


Article
A New Fractal Microstrip Bandpass Filter Design Based on Dual-Mode Square Ring Resonator for Wireless Communication Systems

Authors: J.K. Ali --- N.N. Husain
Pages: 9-14
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Abstract

A new fractal design scheme has been introduced to generate dual-mode microstrip bandpass filter designs with miniaturized sizes for wireless applications. The presented fractal scheme is based on the Koch pre-fractal geometry applied to the conventional dual-mode microstrip square ring resonator as an initiator in the fractal generation process. The space-filling property that the proposed structures possesses, was found to produce reduced size symmetrical structures corresponding to the successive iteration levels. In addition, self-similarity of the whole structure about its diagonal, at any iteration level, enables it to produce the two degenerate modes which can then be coupled using a proper perturbation technique. These filter designs are of sizes suitable for use in modern wireless communication systems. The performance of each of the generated bandpass filter structures up to the 2nd iteration has been analyzed using a method of moments (MoM) based software IE3D, which is widely adopted in microwave research and industry. Results show that these filters possess good transmission and return loss characteristics, besides the miniaturized sizes gained; meeting the design specifications of most of wireless communication systems.


Article
Torque and Magnetic Flux Analysis Using an Advanced Dynamic Dynamometer Test Bed for Electromechanical Motors

Authors: J.M. Al-Baiaty --- N.F. Daoud --- H.G. Khayat
Pages: 19-26
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Abstract

This paper describes the torque and magnetic flux analysis using an advanced dynamic dynamometer test bed for electromechanical motors. Test motor was tested under different levels of continuous loads and high bandwidth complex duty cycle loads in order to provide data to characterize the nonlinear properties of electric motors. The test bed to obtain torque saturation limit data is comprised of a servo motor which serves as a dynamic load emulator, a brake, a clutch, and full sensor array for comprehensive monitoring of test variables, (including magnetic flux density sensor). The magnetic flux test was conducted to discriminate magnetic saturation from torque saturation. Given the permanent magnet motor test system designed for a desired saturation limit, it is possible to predict saturation using a properly defined dynamic duty cycle norm as a function of the operating conditions and the actuator design parameters. In this paper, the temperature effects on the magnetic properties of the permanent magnet material were the principal objectives.


Article
Effect of Bath Temperature on the Optoelectronic Characteristics of Chemically Deposited CdS Thin Films

Authors: S.M.H. Aljawad
Pages: 29-32
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Abstract

Highly photosensitive CdS thin films with photocurrent to dark current ratio (Iph/Id) of ~105 under 300W.m-2 illumination were reported. The films are prepared by an electroless chemical deposition technique. The temperature of the chemical bath used in the electroless deposition of cadmium sulfide thin films has been found to affect the deposition rate, optical transmission, photoconductivity, photoconductivity to dark conductivity ratio σph/σd and photocurrent decay time.


Article
High-Quality Plasma- Induced Crystallization of Amorphous Silicon Structures

Authors: A.M. Aldhafiri
Pages: 35-39
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Abstract

The investigation of polycrystalline silicon made on glass and carbon coated nickel substrates by aluminum-induced crystallization of amorphous silicon (a-Si) is reported. Aluminum was sputtered onto a- Si films deposited in an ultra-high-vacuum plasma-enhanced chemical vapor deposition (PECVD) system to form Al/a-Si substrate structures. These samples were then vacuum annealed for 30min. at temperatures in the range 150-350°C. X-ray diffractometry (XRD) was utilized to determine the crystallization temperature. Annealing at 275°C resulted in the formation of crystalline Si as observed by XRD. The presence of these hillocks or bumps after annealing at 275°C and above confirms that the a-Si has been crystallized.

Keywords

PECVD --- polycrystalline Si --- Amorphous Si --- XRD


Article
Characteristics of a-Si:H Solar Cell Under Extended Illumination Condition Using NIR Laser

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Abstract

In this work, characteristics of a-Si:H solar cell under extended illumination condition, using an NIR laser diode, were studied. These characteristics were introduced by calculations of recombination rate, open-circuit voltage and defect growth rate as functions of illumination time. Stabilized open-circuit voltage of 0.04V and photogeneration rate of ~2x1021cm-3 were observed. We present measurements on the decline of the open-circuit voltage VOC in a-Si:H solar cells during extended illumination (light-soaking). We used a near-infrared laser that was nearly uniformly absorbed in the intrinsic layer of the cell. At the highest photogeneration rate (about 2x1021cm-3), a noticeable decline (0.01V) occurred within about 10 minutes; VOC stabilized at 0.04V below its initial value after about 200 hours. We found that both the kinetics and the magnitudes of VOC are reasonably consistent with the predictions of a calculation combining a bandtail+defect picture for recombination and a hydrogen-collision model for defect generation.


Article
Interfacial Adhesion of PZT Ferroelectric Thin Films Determined by Nano-Indentation Method

Authors: X.J. Zheng --- Y.C. Zhou
Pages: 46-48
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Abstract

We propose an elastic groundsill beam model with piezoelectric effect considered to assess the interfacial adhesion of ferroelectrics thin films, complemented and validated by nano-indentation fracture test on Pb(Zr0.52Ti0.48)O3 (PZT) thin films. It was observed from the loadindentation depth curves and atomic force microscopy (AFM) images that the fracture failure of PZT thin films induced by nano-indentations can be divided into three typical stages: no damage, bulging and spallation. The delamination of thin film systems was modeled as an interfacial crack propagation problem, with the energy release rate determined from the elastic groundsill beam model. For PZT thin films deposited on single Si substrate with thickness of 350nm and 450nm, the energy release rates per unit new crack area are in the range of 3.399~52.432J/m2 and the phase angles are constant of 13.3570.

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