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Al Jīzah, Egypt

Kamel B.M.,National Research Center of Egypt | Mohamed A.,Akhbar El Yom Academy | El Sherbiny M.,Cairo University | Abed K.A.,National Research Center of Egypt
Fullerenes Nanotubes and Carbon Nanostructures | Year: 2016

Recently, nanofluids attract considerable interest for enhanced rheological behavior and thermal performance. The aim of this research is to study the influence of additives Multi-Walled Carbon Nanotubes (MWCNTs) on the rheological behavior and its structure, thermal conductivity, and the influence of shear thinning rate on oil separation at different temperatures for calcium grease. Various concentrations of MWCNTs (0.5, 1, 2, 3, and 4%) have been added to the grease to obtain the best percentages that improve the properties of nanofluid. The microstructure of MWCNTs and nanofluid were examined by X-ray diffraction (XRD), Transmission Electron Microscope (TEM), and Scanning Electron Microscope (SEM). These experimental investigations were evaluated with a Brookfield programmable Rheometer DV-III ULTRA. The results indicated that the optimum concentration of MWCNTs was 3%, and the dropping point increasing about 11%. The rheological behaviors of the nanofluids show that the grease with various concentrations of MWCNTs demonstrates non Newtonian behaviors and the results indicated that the shear stress, apparent viscosity and thermal conductivity increase with the increase of volume concentration of MWCNTs to 65%, 52%, and% 56, respectively. © 2016 Taylor & Francis Group, LLC. Source

Gharib T.F.,Ain Shams University | Fouad M.M.,Akhbar El Yom Academy | Aref M.M.,Ain Shams University
Advanced Techniques in Computing Sciences and Software Engineering | Year: 2010

Text mining refers generally to the process of extracting interesting information and knowledge from unstructured text. This area is growing rapidly mainly because of the strong need for analysing the huge and large amount of textual data that reside on internal file systems and the Web. Text document clustering provides an effective navigation mechanism to organize this large amount of data by grouping their documents into a small number of meaningful classes. In this paper we proposed a fuzzy text document clustering approach using WordNet lexical categories and Fuzzy c-Means algorithm. Some experiments are performed to compare efficiency of the proposed approach with the recently reported approaches. Experimental results show that Fuzzy clustering leads to great performance results. Fuzzy c-means algorithm overcomes other classical clustering algorithms like k-means and bisecting k-means in both clustering quality and running time efficiency. © Springer Science+Business Media B.V. 2010. Source

Seddeek M.A.,Qassim University | Seddeek M.A.,Akhbar El Yom Academy | Odda S.N.,Helwan University | Abdelmeguid M.S.,Ain Shams University
Journal of Aerospace Engineering | Year: 2016

An analytical study is presented for the effects of chemical reaction and mass transfer on the free convective flow of a viscous and incompressible fluid past a vertical isothermal cone surface. The derived fundamental equations on the assumption of small magnetic Reynolds number are solved. A comparison between the analytical and numerical solution has been included in the analysis. The effects of buoyancy parameter, chemical reaction parameter, and Schmidt number on the flow field are discussed through graphs. © 2015 American Society of Civil Engineers. Source

Mohamed A.,Akhbar El Yom Academy | Mohamed A.,Cairo University | Osman T.A.,Cairo University | Khattab A.,Cairo University | Zaki M.,Cairo University
Journal of Tribology | Year: 2015

Carbon nanotubes (CNTs) with 10 nm average diameter and 5 lm in length were synthesized by electric arc discharge. The morphology and structure of CNTs were characterized by high resolution transmission electron microscopy (HRTEM) and X-ray powder diffraction. The tribological properties of CNTs as an additive on lithium grease were evaluated with a four ball tester. The results show that the grease with CNTs exhibit good performance in antiwear (AW) and decrease the wear scare diameter (WSD) about 63%, decrease friction reduction about 81.5%, and increase the extreme pressure (EP) properties and load carrying capacity about 52% with only 1% wt. of CNTs added to lithium grease. The action mechanism was estimated through analysis of the worn surface with a scanning electron microscope (SEM) and energy dispersive X-ray (EDX). The results indicate that a boundary film mainly composed of CNTs, Cr, iron oxide, and other organic compounds was formed on the worn surface during the friction process. Copyright © 2015 by ASME. Source

Khalil W.,Akhbar El Yom Academy | Mohamed A.,Akhbar El Yom Academy | Bayoumi M.,Al - Azhar University of Egypt | Osman T.A.,Cairo University
Fullerenes Nanotubes and Carbon Nanostructures | Year: 2016

This study examined the tribological properties of two lubricating oils, mobil gear 627 and paraffinic mineral oils, with multi-walled carbon nanotubes (MWCNTs) nanoparticles used as additives with various concentrations (0.1, 0.5, 1, and 2 wt.%). The friction and wear experiments were performed using a four ball tribotester. The samples were tested for their anti-wear, load carrying capacity, and friction coefficients according to ASTM D-2783, ASTM D-2596, and ASTM D-5183 standards. The experimental results show that the addition of MWCNTs to base oils exhibit good friction reduction and anti-wear properties. The wear test results show a decreased wear by 68% and 39% in the case of MWCNTs-based mineral oil as compared with base mobil gear 627 and paraffinic mineral oils, respectively. Furthermore, the friction reduction results show a decrease of friction about 57% and 49% in the case of MWCNTs-based mineral oil as compared with base mobil gear 627 and paraffinic mineral oils, respectively. The weld load of the base oil containing 1% MWCNTs was found to be 400 kgf and 125 kgf as compared with base mobil gear 627 and paraffinic mineral oils, respectively, which got welded at 200 kgf and 100 kgf. The morphologies and typical element distribution of the worn surfaces were characterized by scanning electron microscope (SEM) and energy-dispersive X-ray (EDX). The SEM micrographs and EDX chemical analysis confirm the formation of a tribolayer composed of the elements from the nanoparticles. © 2016 Taylor & Francis Group, LLC. Source

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