Volume 2, Issue 4, July 2011
Electrodeposition and Characterization of Nickel-Titania Nanocomposite Coatings from Gluconate Baths
M. S. Ali Eltoum, A. M. Baraka, M. Saber M. and ELfatih A. Hassan
Scientific Laboratories Department, Faculty of Science, Sudan University of Science & Technology, Khartoum, Sudan
Chemistry Department, Faculty of Science, Cairo University, Cairo, Egypt
Ni–TiO2 Nanocomposites with varying Titania content were electrodeposited on copper substrate employing gluconate electrolyte. The changes in microstructure and corrosion behavior of electrodeposited nickel with respect to Titania addition were studied. The Titania content in the coatings increased with increasing Titania content in the bath and decreased at high current density, the effect of pH shows en increase in Titania up to pH 8. Enhancement in hardness and corrosion resistance were observed due to titania Incorporation in Ni-matrix and also the addition of TiO2 nanoparticles to the bath, affect the microstructure and the morphology of the nickel matrix as indicated from the X-ray diffraction (XRD) and scanning electron microscope (SEM) results.
—Ni-TiO2 Nanocomposite, Electrodeposition, Corrosion Resistance and Polarization Curves
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Wavelet Domain Quantization Based Video Watermarking
Afshin Shaabany and Fatemeh Jamshidi
Science and Research Branch, Islamic Azad University, Fars, Iran
In this Article we initiate a digital watermarking technique for working in the Discrete Wavelet Transform domain. The plan practice binary images as watermarks. The maximum capacity is not essential in most implementation; thereby we have diminished it to increase the robustness of the plan. Every bit of the watermark is extending over a number of wavelet coefficients with the use of a secret key. We use error correction codes to increase in quality the resilience of the algorithm. we choose f the quantization step q is a tradeoff between the intuitive qualities of the watermarked video Inverse Discrete Wavelet Transform is computed to obtain the watermarked video the q should be small so we try the plan with q=8.The results have very good intuitive quality with mean PSNR values of the watermarked videos and great resistance to a large spectrum of assault.
— Digital Watermarking, Domain Quantization and Resilience to Assault
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Recent Progress of LiNbO3 Based Electrooptic Modulators with Non Return to Zero (NRZ) Coding in High Speed Photonic Networks
Abd El–Naser A. Mohamed, Mohamed A. Metawe'e, Ahmed Nabih Zaki Rashed and Amira I. M. Bendary
Electronics and Electrical Communications Engineering Department, Faculty of Electronic Engineering, Menouf 32951, Menoufia University, EGYPT
High frequency, and broad bandwidth technology development in photonic network applications is being driven by the need to quickly process and distribute large amounts of information. Due to the high cost, complexity, and performance limitations of electronic high frequency systems, hybrid electrical-optical or all-optical systems are necessary. Current off-theshelf optical components function well at frequencies below 20 GHz, but their performance begins to degrade quickly above 40 GHz. This performance degradation results primarily from limitations in the crystalline electrooptic materials currently used to fabricate optical components. Optical components and integrated optical devices that operate at high frequency and with high bandwidth are necessary for next generation applications such as high capacity optical networks, high speed microprocessors, and high frequency wireless communications. Therefore, this paper has proposed the recent progress of LiNbO3 based Electrooptic modulator devices in high speed photonic access communication networks. We have investigated the cut-off frequency, 3-dB bandwidth, modulation bandwidth, transmission bit rates and products within NRZ coding over wide range of the affecting parameters.
—Integrated Optoelectronics, Optoelectronic Devices, Optical Modulation, Optical Planar Waveguide and NRZ Coding
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A hybrid Power series – Cuckoo Search Optimization Algorithm to Electrostatic Deflection of Micro Fixed-Fixed Actuators
Aminreza Noghrehabadi, Mohammad Ghalambaz, Mehdi Ghalambaz and Amir Vosoogh
Department of Mechanical Engineering, Shahid chamran university of Ahvaz, Ahvaz, Iran
Department of Mechanical Engineering, Dezful Branch, Islamic Azad University, Dezful, Iran
Department of Mechanics, Mahshahr Branch, Islamic Azad University, Mahshahr, Iran
A hybrid Power series and Cuckoo Search via L´evy Flights optimization algorithm (PS-CS) method is applied to solve a system of nonlinear differential equations arising from the distributed parameter model of a micro fixed-fixed switch subject to electrostatic force and fringing filed effect. To aim this purpose, a trial solution of the differential equation is defined as sum of two polynomial parts. The first part satisfies the boundary conditions and does not contain any adjustable parameter and the second part which is constructed so as not to affect the boundary conditions and involves adjustable parameters. The cuckoo search via l´evy flights optimization algorithm is applied to find adjustable parameters of trial solution. The obtained results are compared with numerical results and found in good agreement. Further more the present method can be easily extended to solve a wide range of boundary value problems.
—Micro, Pull-in, Fix-Fix, Electromechanical Switches, Power Series, Cuckoo Search via L´evy Flights and Optimization
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Harmful Proton Radiation Damage and Induced Bit Error Effects on the Performance of Avalanche Photodiode Devices
Abd El-Naser A. Mohamed, Mohamed M. E. El-Halawany, Ahmed Nabih Zaki Rashed and Hazem M. El-Hageen
Electronics and Electrical Communication Engineering Department,
Faculty Electronic Engineering, Menouf, 32951, Egypt
Atomic Energy Authority, P.O. Box 29, Naser City, Cairo, Egypt
This paper has been tested the radiation dependent characteristics of the avalanche photodiodes. Raising the current density however, is not really indicative of lifetime since it is more likely a situation to be avoided than one that simulates normal lifetime degradation. The reliability of semiconductor detectors is very dependent on the degradation modes. This paper has presented the main irradiation effects, i.e., the multiplication gain, minority carrier life time, impact ionization, illumination and radiation damage coefficient. By comparing neutrons, protons and gamma radiation effects, we will apply the model on the two different Silicon avalanche photodiode structures. The results demonstrate that the model can accurately calculate the internal parameters of the APDs and produce data that can be directly compared with measurements. The fluence effects of 51 MeV proton irradiation on the photosensitivity and signal to noise ratio (SNR) are also investigated. The objective was to analyze the effect depletion region volume, carrier concentration of the i-region of APDs on radiation hardness. Moreover we have investigated deeply some of the degradation performance and capabilities of typical APDs currently used in many communication and sensing systems over wide range of the affecting parameters. APDs are used in systems that require coherent and often single mode light such as high data rate communications and sensing applications. APDs are an attractive receiver choice for low signal applications, because their internal gain mechanism can improve signal to noise ratio. An optical receiver must also be appropriate for the laser wavelength being used. As well as we have taken into account the effects of excess noise on the device performance, and upgrading signal to noise ratio and then to decrease the bit error rated that has a bad effect on the device performance and operating efficiency.
—Optoelectronic Devices, Radiation Damage, Signal to Noise Ratio, Bit Error Rate and Excess Noise
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The Approach for Migrating Data Intensive Web Application into Semantic Web Application
Munteha Riaz and Amjad Farooq
Computer Science and Engineering Department, University Of Engineering and Technology Lahore-Pakistan
Upcoming revolution in history of web is semantic web. Apparently solution of many drawbacks of current web is Semantic web. Our goal is to transform Data Intensive Web to Semantic web by applying set of rules. After study and evaluation of different approaches, a rules set is been presented, in consolidated and more generalized form, which is integrated and also semi automatic. Also some relationship rules are proposed to map relationship entities onto Ontology classes, which eventually assist in transforming to Semantic web.
—Web Applications, Web-Semantic and Data Intensive
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Flicker Mitigation Approach Based on Three-Level STATCOM
Mohammad Sadegh Javadi
Department of Electrical Engineering, Science and Research Branch, Islamic Azad University, Fars, Iran
This paper presents an effective flicker mitigation approach using three-level STATCOM. In this model, fluctuations and other power quality problems caused by large time-varying loads, like arc furnaces, have been mitigated. Three-level inverter based STATCOM is applied to reduce this kind of disturbances. With the availability of recent forced-commutated components, such as IGBT and GTO, a STATCOM becomes possible to be implemented as an efficient means to reduce voltage fluctuations causing flicker. Based on the three-level digital modeling of STATCOM which is equipped with a phase locked loop, both large time-varying and short time-varying power quality phenomenon would be mitigated. The simulation results show that the presented method is both satisfactory and consistent with expectation.
—Light flicker, STATCOM, Three-level Inverter and Power Quality
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Exergy Concept and its Characteristic
Amir vosough, Aminreza Noghrehabadi, Mohammad Ghalambaz and Sadegh Vosough
Department of Mechanics, Mahshahr Branch, Islamic Azad University, Mahshahr, Iran
Departments of Mechanics, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran
Departments of Mechanics, Dezful Branch, Islamic Azad University, Dezful, Iran
In this paper about the concept of exergy, application of exergy in various fields and its characteristic has been discussed and different forms of exergy have been derived. Also a brief comparison between energy and exergy analysis has been done.
—Exergy, Application, Analysis and Characteristic
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