Browsing by Author "Osman, T. A."

Now showing 1 - 9 of 9

An effective removal of organic dyes using surface functionalized cellulose acetate/graphene oxide composite nanofibers
(SPRINGER, VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS, 2018-07) Aboamera, Nada M.; Mohamed, Alaa; Salama, Ahmed; Osman, T. A.; Khattab, A.
An effective photocatalyst obtained from composite nanofibers CA/GO fabricated by electrospinning technique followed by chemical crosslinking surface modified TiO2 nanoparticles (NPs) was used for removing the organic dyes Indigo carmine (IC) and Methylene blue (MB) from an aqueous solution under UV irradiation light. The crystalline structure and morphologies of CA-GO/TiO2-NH2 composite nanofibers were characterized by SEM, TEM, XRD, and FTIR. The prepared CA-GO/TiO2-NH2 composite nanofibers displayed significantly enhanced photocatalytic activity for photodegradation the organic dyes IC and MB under UV irradiation after 150 and 250 min respectively. The pH value of the solution was studied from 2 to 8 and obtained results showed a clear improvement of photocatalytic activity at pH 2. The results indicated that the activated CA-GO/TiO2-NH2 composite nanofibers functioned as an adsorbent for the removal of IC and MB from aqueous solutions. In addition, the results showed a high adsorption capacity remain up to 65% after five consecutive capacity cycles.
Effects of Increasing Electrodes on CNTs Yield Synthesized by Using Arc-Discharge Technique
(Hindawi Publishing Corporation, 2013) Yousef, Samy; Khattab, A.; Osman, T. A.; Zaki, M.
A new design of fully automatic system was built up to produce multiwalled carbon nanotube (MWCNT) using arc discharge technique in deionized water and extra pure graphite multiple electrodes (99.9% pure). The goal of the experimental research is to determine the yield of CNT in two different cases: (a) single plasma electrodes and (b) multiplasma electrodes, particularly 10 electrodes. The experiments were performed at constant parameters (75 A, 238 V). The obtained CNT was examined by scanning electron microscope (SEM), transmission electron microscope (HRTEM), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The results showed that the produced CNT is of type MWCNT, with a diameter of 5 nm, when using multiplasma electrodes and 13 nm when using single plasma electrodes. The yield of MWCNT was found to be 320% higher in case of comparing multielectrodes to that of single plasma electrodes. Under the experimental test conditions, a yield of 0.6 g/hr soot containing 40% by mass nanotube was obtained in case of single plasma electrodes and above 60% in case of multiplasma electrodes.
Fully automatic system for producing carbon nanotubes (CNTs) by using arc-discharge technique multi electrodes
(IEEE, 2012) Yousef, Samy; Khattab, A.; Osman, T. A.; Zaki, M.
The production and industrial applications of carbon nanotubes (CNT) are recently the main concern of research in nanotechnology. CNT exhibit unique properties which have valuable commercial applications ranging from electronics to chemical processes. The main goal of the present paper is to develop the complete design of fully automatic system for producing carbon nanotubes (CNTs) by using deionized water and extra pure graphite multiple electrodes (99.9% pure). The advantage of the designed system is the increase yield of Carbon Nanotubes CNTs within the experimental limitations, through the increase of the number of cathodes and anodes and by using automatic feeding system for the electrodes, considering techniques at lower costs. The results of these experiments were examined by scanning electron microscope (HRSEM) and transmission electron microscope (HRTEM). The results show that the produced CNTs are multi-wall carbon nanotubes with average diameter of 25nm.
High performance of PAN/GO-ZnO composite nanofibers for photocatalytic degradation under visible irradiation
(ELSEVIER SCIENCE BV, 2019-08) Khattab, A; Osman, T. A.; Karim, Shrouk; Khalil, Alaa; Abdel-Mottaleb, M. M
In this work, Polyacrylonitrile nanofibers were enhanced by graphene oxide and zinc oxide, in terms of enhanced the photocatalytic activity and mechanical properties for the composite nanofibers. Photocatalytic degradation of two organic dyes methylene blue dye and indigo carmine dye from the simulated industrial wastewaters has been investigated under visible light irradiation. Composite nanofibers fabricated by using electrospinning technique followed by chemical cross-linking with zinc oxide. The surface sensitization and morphology changes of the fabricated composite nanofibers were studied using Fourier transform infrared spectroscopy analysis, Scanning Electron Microscopy and transmission electron microscope. Sensitized zinc oxide with graphene oxide showed higher efficiency in the degradation of MB with a 96% of degradation efficiency after 70 min and 98% for IC after merely 27 min. The optimum catalytic parameters such as initial organic dye concentration and pH were discussed. The efficacy of degradation of methylene blue dye and indigo carmine increased as initial concentration decreased. The optimal pH was around 5 where the reaction rate decreases above and under this pH value.
Improved mechanical and tribological properties of A356 reinforced by MWCNTs
(Taylor & Francis, 2018) El Shalakany, Abou Bakr; M. Kamel, Bahaa; Khattab, A.; Osman, T. A.; Azzam, B.; Zaki, M.
The objective of this paper is to investigate the effect of Multi-Walled Carbon Nanotubes (MWCNTs) content on microstructure and dry sliding wear behavior of hypo-eutectic A356Al–Si alloy Metal Matrix Nano-Composites (MMNCs). Composites containing 0.5, 1.5, and 2.5 wt.% MWCNTs were prepared by rheocasting technique followed by squeeze casting. Characterization of nanocomposites was done by scanning electron microscopy (SEM) equipped with energy dispersive X-ray analysis (EDX), dry sliding wear tests were performed in a pin-on-disk wear tester against a steel disk at various speeds and normal loads. Results revealed that a decrease in both wear rate and friction coefficient of the nanocomposites considerably with the increase of MWCNT’s content. The formation of the hard compact transfer layer on the pin surface nanocomposites assisted in increasing the wear resistance of these materials. It is that the transfer layer which was formed under an applied load of 20 N can act as a protective layer and help in reducing the wear rate. The results indicate the nano composites could be used in light-weight applications where moderate strength and wear properties are needed.
Investigation of gear performance of MLNGPs as an additive on polyamide 6 spur gear
(TAYLOR & FRANCIS INC, 2018) Zian, H; Kamel, Bahaa M; Osman, T. A.; Elshalakny, Abou Bakr; Afifi, Esraa M
Molded plastic gears have long provided an alternative to metal gears in lightly loaded drives. They transmit power quietly and often without lubrication in numerous applications, furthermore decrease the quantity of parts and oppose chemicals in numerous applications. Previously, plastic gears were restricted to to 0.25hp because of varieties in their properties and uncertainties about how they react to natural conditions such as moisture, temperature and chemical. Today, better molding controls combined with design practices that more accurately encompass environmental factors have boosted plastic gear drive capacity to 1.5hp. Using reinforcement this is standout amongst the most practices to enhance the gear performance.This study estimated the effects of multilayer graphene nanoplatelets (MLNGPs) as an additive on polyamide 6 (PA6) spur gear performance. These include strength, elastic modulus, thermal stability, dynamic mechanical analysis, moisture absorption, and wear characteristics.The nanocomposite gear was made by melt mixing method and injection moulded into thick flanges. The flanges were machined using CNC milling machine to produce spur gear. The wear experiments were performed at a running speed of 1400rpm and at torques of 13 and 16Nm with different concentration 0, 0.1, 0.3 and 0.5wt% MLNGPs using test rig. The result showed that 0.3% of MLGNPs is the optimum concentration. Young's modulus increased up to 40%, Vickers microhardness value increased up to 25%, storage modulus E' is increased up to 37% and glass transition temperature is increased up to 14%. On the other hand TGA result shows that the Tonest increased up to 7.5% and Td increased up to 2%, and wear decreased by 35% at 16Nm and 54% at 13Nm.
Microstructure and Mechanical Properties of MWCNTs Reinforced A356 Aluminum Alloys Cast Nanocomposites Fabricated by Using a Combination of Rheocasting and Squeeze Casting Techniques
(Hindawi Publishing Corporation, 2014) Elshalakany, Abou Bakr; Osman, T. A.; Khattab, A.; Azzam, B.; Zaki, M.
A356 hypoeutectic aluminum-silicon alloys matrix composites reinforced by different contents of multiwalled carbon nanotubes (MWCNTs) were fabricated using a combination of rheocasting and squeeze casting techniques. A novel approach by adding MWCNTs into A356 aluminum alloy matrix with CNTs has been performed. This method is significant in debundling and preventing flotation of the CNTs within the molten alloy. The microstructures of nanocomposites and the interface between the aluminum alloy matrix and the MWCNTs were examined by using an optical microscopy (OM) and scanning electron microscopy (SEM) equipped with an energy dispersive X-ray analysis (EDX). This method remarkably facilitated a uniform dispersion of nanotubes within A356 aluminum alloy matrix as well as a refinement of grain size. In addition, the effects of weight fraction (0.5, 1.0, 1.5, 2.0, and 2.5 wt%) of the CNT-blended matrix on mechanical properties were evaluated. The results have indicated that a significant improvement in ultimate tensile strength and elongation percentage of nanocomposite occurred at the optimal amount of 1.5 wt% MWCNTs which represents an increase in their values by a ratio of about 50% and 280%, respectively, compared to their corresponding values of monolithic alloy. Hardness of the samples was also significantly increased by the addition of CNTs.
Noise assessment and mitigation schemes for Hurghada airport
(ELSEVIER, 2007) Arafa, Mustafa H.; Osman, T. A.; Abdel-Latif, Ibrahim A.
In recent years, concern over airport noise and its impact on surrounding communities has been spurred by a continual growth in air traffic together with urban development in close proximity to many airports around the world. This paper aims at studying the case of Hurghada airport, Egypt, with a focus on evaluating, both theoretically and practically, the airport noise and its impact on the city of Hurghada. Extensive field measurements of aircraft noise were undertaken at key locations in the city, including points lying within the premises of the Hurghada airport. The aircraft noise was also modeled using the integrated noise model (INM) in order to simulate the current and future noise levels based upon the anticipated steady increase in flight operations. Such forecasts are of particular importance for Hurghada as the number of flights is expected to grow steadily over the next decade, accompanied with an increase in urban growth for coastal resorts. Based on the actual measurements and computer simulation, noise mitigation schemes are suggested to alleviate current and future impacts. (c) 2006 Elsevier Ltd. All rights reserved.
Wear Characterization of Carbon Nanotubes Reinforced Polymer Gears
(IEEE, 2013) Yousef, Samy; Khattab, Ahmed; Zaki, M.; Osman, T. A.
In last decade, polymeric gears have found wide applications in industrial fields. This is due to their advantages like noise reduction, self-lubricating features, weight reduction, cost savings as well as lower tribological characteristics in term of friction and wear. The main objective of this paper is to study the wear behavior of spur gears that makes polymer blended by carbon nanotubes (CNTs) (acetal). This was made by using appropriate adhesive oil (Paraffin) during injection moulding practice to produce thick flanges with diameter 134 mm and thickness 29 mm. The CNTs were produced by a fully automatic system using arc-discharge technique multi-electrodes. The synthesizing CNT/acetal flanges contain 1% CNTs by weight. The flanges were machined using CNC milling machine to produce spur gears. The dispersion of CNTs in polymer were examined by scanning electron microscope. The experiments were performed at a running speed of 1420 r/min and at torques of 13 and 16 N·m. In addition, the mechanical properties of CNT/acetal have been tested. The results showed that the wear resistances of the CNTs/acetal spur gears increased with the addition of CNT. The strength, Young's modulus and stiffness also increased while the hardness was not affected by the addition of CNT.