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Cairo, Egypt

Baraka A.,Egyptian Armed Forces
Desalination and Water Treatment | Year: 2012

This work presents in-pores degradation of a dye that was subjected to adsorption into a transparent adsorbent. The degradation was performed by UV-illumination of the dye-loaded adsorbent. This degradation by UV-illumination is considered as a regeneration technique for the adsorbent. For this specific aim, a new transparent adsorbent was prepared. It is a hybrid resin-gel composed of melamine formaldehyde tartaric acid/acrylamide tartaric acid (MFT/AT). methylene blue (MB) was selected as a typical contaminant dye due to its known degradability by UV rays. A sample of MFT/AT was used through 10-cycles of MB-adsorption/UV-illumination applying batch method. For each cycle, MB was apparently completely degraded. Rate of MB-adsorption by MFT/AT was investigated applying pseudo second order model for the 1st and 10th cycles. It was found that adsorption rate and capacity were not significantly changed (rate constants = 0.186, 0.199 g mg-1 min -1 and capacities = 0.264, 0.258 mg g-1 respectively). A fresh and the 10th-cycle-used samples of MFT/AT were characterized through Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis, Brunauer, Emmett and Teller method (BET) and scanning electron microscope to discover the side effect of UV-illumination on chemical, physical, morphological and aerial properties of adsorbent. It was found that MFT/AT was chemically and physically changed but its morphological and aerial properties did not change significantly. © 2012 Desalination Publications. All rights reserved.

In this study, a new resin Melamine-Formaldehyde-Tartaric acid (MF-T) was synthesized to investigate the removal of tartrazine (TZ) and methylene blue (MB) dyes. The resin was chemically, physically and morphologically characterized using IR, BET, SEM, TGA, and water content analyses. Kinetics and isotherms of TZ and MB adsorption by MF-T were studied applying batch method. Adsorption-rate data was modeled by pseudo first order (PFO) and pseudo second order (PSO) kinetic models. It was concluded that the rate of adsorption follows PSO model for both dyes. Isotherm study suggests Freundlich and Langmuir models to represent adsorption of TZ and MB respectively at equilibrium. Thermodynamic study revealed that adsorption of TZ and MB onto MF-T is spontaneous. Adsorption is exothermic for TZ in the range 15-30°C and endothermic in the range 30-45°C while it is exothermic for MB over the whole temperature studied range; 15-45°C. The regeneration experiment of MF-T by a physical treatment indicated the ease of desorbing MB from MF-T surface compared to TZ. From kinetic, isotherm, thermodynamic and regeneration studies, it is revealed that physical adsorption is the predominant removal mechanism for TZ at low temperature range and a chemical/physical adsorption process is postulated at higher temperature range. For MB, it is proposed that physical adsorption is the sole removal mechanism over all studied temperature range. It is concluded that MF-T is suitable to remove MB. The present work gives evidence that PSO model can fit both physical and chemical adsorption processes. © 2012 Desalination Publications. All rights reserved.

Sobh T.S.,Egyptian Armed Forces | Mostafa W.M.,Cairo University
Applied Soft Computing Journal | Year: 2011

Technology and biological systems have now bi-directional relation that each benefits from the other. Biological systems naturally enjoy many attractive features and inherent intelligence that fit in solving many research problems. The natural immune system as one of those biological systems is considered a good source of inspiration to artificial defense systems. It has its own intelligent mechanisms to detect the foreign bodies and fight them and without it, an individual cannot live, even just for several days. The new types of network attacks evolved and became more complex, severe and hard to detect. This resulted in increasing need for network defense systems, and especially those with unordinary approaches or with ability to face the dynamic nature of new and continuously changing network threats. In this work we investigate different AIS theories and show how to combine different ideas to solve problems of network security domain. An Intrusion Detection System (IDS) that apply those ideas was built and tested in a real-time environment to test the pros and cons of Artificial Immune System (AIS) and clarify its applicability. Also some investigation on the vaccination biological process is introduced. A special module was built to perform this process and check its usage and how it could be formulated in artificial life. © 2010 Elsevier B.V. All rights reserved.

Diffusion-binding kinetic model (DB-model) has been recently introduced to represent the rate of batch adsorption for aqueous-solution/porous-solid systems and the applicability of DB-model was examined and verified considering the effect of initial concentration. In the present work, the applicability of DB-model is further discussed considering the effect of temperature on the removal performance of two adsorption systems; copper(II)/MF-DTPA and tartrazine/MFT/AT. DB-model was applied according to two aspects; surface-interaction kinetic modeling and diffusion kinetic modeling. To asses the performance of DB-model, its outputs were compared with the outputs of pseudo second order model as a surface-interaction kinetic model and Webber-Morris model as a diffusion kinetic model. The results showed the success of DB-model to represent both adsorption systems considering the two aspects. For surface-interaction application, DB-model is competitive to PSO-model to represent the studied adsorption systems as it estimated the total adsorption amounts with relative error (RE%) lower than 3%, the determined rate constants (kDB) are in regular decrease with temperature increase indicating exothermic nature of adsorption, and in addition DB-model indicates diffusions contribution in adsorption process as diffusion index (n) is less than 1. For diffusion application, DB-model showed multi-linearity plots with break points which are similar to the plots and break points of Webber-Morris model. From DB-model plots, the diffusion steps that are contributing in controlling the overall rate of adsorption can be suggested. © 2014 Elsevier Ltd. All rights reserved.

El-Mahlawy M.H.,Egyptian Armed Forces
Proceedings of the IEEE International Conference on Electronics, Circuits, and Systems | Year: 2016

In this paper, the new signature multi-mode hardware-based self-test architecture (SM-HBST) for digital integrated circuits (ICs) is presented for fault diagnosis. It generates test patterns either pseudo-randomly, or deterministically to test the random logic. Also, it generates efficient test patterns to test the static random access memory (SRAM) based on March testing approach. The response of the circuit is evaluated by the test response compactor (TRC). The proper timing between the test pattern generator (TPG), the circuit under test (CUT), and the TRC is achieved to control the test cycle for stable signature generation. In addition, this architecture can test the single-shot (SS) circuit by measuring the time duration based on the edge detecting of the generated pulse. This time duration is considered the signature of its proper functionality. The SM-HBST is design and implemented based on the Field Programmable Gate Array (FPGA) technology. The experimental results illustrate the efficiency of the SM-HBST as the integrated test solution for fault diagnosis of the digital circuit boards. © 2015 IEEE.

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