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Farag M.M.,Alexandria University | Azab M.,City of Scientific Research and Technological Applications | Mokhtar B.,Alexandria University
IEEE PES Innovative Smart Grid Technologies Conference Europe | Year: 2015

Security is a major challenge preventing wide deployment of the smart grid technology. Typically, the classical power grid is protected with a set of isolated security tools applied to individual grid components and layers ignoring their cross-layer interaction. Such an approach does not address the smart grid security requirements because usually intricate attacks are cross-layer exploiting multiple vulnerabilities at various grid layers and domains. We advance a conceptual layering model of the smart grid and a high-level overview of a security framework, termed CyNetPhy, towards enabling cross-layer security of the smart grid. CyNetPhy tightly integrates and coordinates between three interrelated, and highly cooperative real-time security systems crossing section various layers of the grid cyber and physical domains to simultaneously address the grid's operational and security requirements. In this article, we present in detail the physical security layer (PSL) in CyNetPhy. We describe an attack scenario raising the emerging hardware Trojan threat in process control systems (PCSes) and its novel PSL resolution leveraging the model predictive control principles. Initial simulation results illustrate the feasibility and effectiveness of the PSL. © 2014 IEEE. Source

Abd-El-Naby B.A.,Alexandria University | Abdullatef O.A.,Pharos University in Alexandria | El-Kshlan H.M.,Alexandria University | Khamis E.,City of Scientific Research and Technological Applications | Abd-El-Fatah M.A.,Alexandria University
Portugaliae Electrochimica Acta | Year: 2015

The inhibitive effect of Lupine extract on the corrosion of etched and non-etched aluminum in aqueous solution of 0.1 M HCl was investigated at 30 ºC by potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and optical microscopic techniques. Potentiodynamic polarization curves indicated that Lupine extract acts as anodic type inhibitor. EIS measurements showed that the charge transfer resistance and consequently the inhibition efficiency increase with increasing concentration of Lupine. The experimental data indicated that Lupine is more efficient as inhibitor for the acid corrosion of non-etched aluminum. The inhibitive effect of the extract was assumed to occur via adsorption of active ingredients of the extract on the metal surface. Theoretical fitting of the data to the Kinetic-thermodynamic model were tested to clarify the nature of adsorption. The optical micrographs obtained after surface pre-treatment show that alkaline etching reveals the surface to be porous-like in structure and both the acid and extract have limited effect on the size of pores. © 2015, Sociedade Portuguesa de Electroquimica. All rights reserevd. Source

Abdalla K.F.,Tanta University | Kamoun E.A.,City of Scientific Research and Technological Applications | El Maghraby G.M.,Tanta University
Journal of Applied Pharmaceutical Science | Year: 2015

The objective of the current study was to optimize the composition of alginate beads to produce ambroxol hydrochloride alginate beads with optimum specifications. The study employed beads based on sodium alginate solution (2% w/v) as the main component with calcium chloride solution as crosslinking agent as the prototype beads. The beads were prepared by syringe method. The effect of viscosity modifiers on the morphology, entrapment efficiency and drug release was studied. The prototype beads were spherical semitransparent with entrapment efficiency (EE) of 23%. Incorporation of polyvinylpyrrolidone (PVP) as a viscosity modifier produced spherical semitransparent beads with higher EE values compared with the prototype. Addition of carboxymethyl cellulose (CMC) produced oval opaque beads which have larger size and higher EE values compared with the prototype beads or those containing PVP only. Replacement of CMC with hydroxypropyl methyl cellulose (HPMC) produced semitransparent spherical beads with significant increase in the EE. Monitoring the drug release rate from different beads, the all the tested beads were able to retain the drug in the stomach condition. In the intestinal conditions the release rate depended on the composition of the beads with prototype beads librating most of its contents in the first 15 minutes. Formulations containing either CMC or HPMC were able to retard the drug release in the intestinal phase. In conclusion the study developed beads with optimum entrapment and release of ambroxol hydrochloride. © 2015 Karam F. Abdalla et al. Source

Mokhtar B.,Alexandria University | Azab M.,City of Scientific Research and Technological Applications
Alexandria Engineering Journal | Year: 2015

Vehicular Ad hoc NETworks are special case of ad hoc networks that, besides lacking infrastructure, communicating entities move with various accelerations. Accordingly, this impedes establishing reliable end-to-end communication paths and having efficient data transfer. Thus, VANETs have different network concerns and security challenges to get the availability of ubiquitous connectivity, secure communications, and reputation management systems which affect the trust in cooperation and negotiation between mobile networking entities. In this survey, we discuss the security features, challenges, and attacks of VANETs, and we classify the security attacks of VANETs due to the different network layers. © 2015 Faculty of Engineering, Alexandria University. Production and hosting by Elsevier B.V. Source

Abd-El-Nabey B.A.,Alexandria University | Abdel-Gaber A.M.,Alexandria University | Abdel-Gaber A.M.,Beirut Arab University | Khamis E.,Alexandria University | And 3 more authors.
International Journal of Electrochemical Science | Year: 2013

The inhibitive efficiency of 6-methyl-2-thioxopyrimidinone (MTP), 6-phenyl-2- thioxopyrimidin-4-one (PhTP) and 5-cyano-6-phenyl-2-thioxopyrimidin-4-one (CPhTP) for brass corrosion in 0.1 M H2SO4 at 300?°C were investigated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. These compounds inhibit the corrosion of brass even at very low concentrations and the order of increasing the inhibition efficiency was correlated with the modification of the molecular structure of the inhibitors. The anodic polarization curves of brass in 0.1 M H2SO4 in presence of higher concentrations of PhTP showed a passivity and limiting current behavior indicating the formation of [Cu(PhTP)]+ sparingly soluble complex. Theoretical fitting of the kinetic-thermodynamic model of the adsorption of inhibitors at the metal surface are tested to clarify the nature of adsorption. Calculation of the activation parameters of the corrosion reaction of copper in absence and presence of the inhibitors indicated that the presence of the cyano group in CPhTP compound favors chemical adsorption of the inhibitor at the metal suface. © 2013 by ESG. Source

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