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Search Results: 1 - 10 of 156808 matches for " El-Shafei B. Zeidan "
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Application of Solar Energy for Recovery of Water from Atmospheric Air in Climatic Zones of Saudi Arabia  [PDF]
Ahmed M. Hamed, Ayman A. Aly, El-Shafei B. Zeidan
Natural Resources (NR) , 2011, DOI: 10.4236/nr.2011.21002
Abstract: In the present work, an investigation on the application of solar energy to heat a sandy bed impregnated with calcium chloride for recovery of water from atmospheric air is presented. The study also aimed at evaluating the effects of different parameters on the productivity of the system during regeneration. These parameters include system design characteristics and the climatic conditions. An experimental unit has been designed and installed for this purpose in climatic conditions of Taif area, Saudi Arabia. The experimental unit which has a surface area of 0.5 m2, comprises a solar/desiccant collector unit containing sandy bed impregnated with calcium chloride. The sandy layer impregnated with desiccant is subjected to ambient atmosphere to absorb water vapor in the night. During the sunshine period, the layer is covered with glass layer where desiccant is regenerated and water vapor is condensed on the glass surface. Ambient temperature, bed temperature and temperature of glass surface are recorded. Also, the productivity of the system has been evaluated. Desiccant concentration at start of regeneration is selected on the basis of the climatic data of Al-Hada region, which is located at Taif area, Saudi Arabia. Experimental measurements show that about 1.0 liter per m2 of pure water can be regenerated from the desiccant bed at the climatic conditions of Taif. Liquid desiccant with initial concentration of 30% can be regenerated to a final concentration of about 44%. Desiccant concentration at start of regeneration is selected on the basis of the climatic data of Al-Hada region. The climate of Taif city is dry compared with that for Al-Hada region. This method for extracting water from atmospheric air is more suitable for Al-Hada region especially in the fall and winter.
Computing the Pressure Drop of Nanofluid Turbulent Flows in a Pipe Using an Artificial Neural Network Model  [PDF]
Mahmoud S. Youssef, Ayman A. Aly, El-Shafei B. Zeidan
Open Journal of Fluid Dynamics (OJFD) , 2012, DOI: 10.4236/ojfd.2012.24013
Abstract: In this study, an Artificial Neural Network (ANN) model to predict the pressure drop of turbulent flow of titanium dioxide-water (TiO2-water) is presented. Experimental measurements of TiO2-water under fully developed turbulent flow regime in pipe with different particle volumetric concentrations, nanoparticle diameters, nanofluid temperatures and Reynolds numbers have been used to construct the proposed ANN model. The ANN model was then tested by comparing the predicted results with the measured values at different experimental conditions. The predicted values of pressure drop agreed almost completely with the measured values.
Friction and Wear of Polymer Composites Filled by Nano-Particles: A Review  [PDF]
Ayman A. Aly, El-Shafei B. Zeidan, AbdAllah A. Alshennawy, Aly A. El-Masry, Wahid A. Wasel
World Journal of Nano Science and Engineering (WJNSE) , 2012, DOI: 10.4236/wjnse.2012.21006
Abstract: Composites formed by adding nano-scale particles to a polymer matrix results in improving electrical, mechanical, and thermal properties of the composite. Good tribological properties can be obtained for polymers filled with nano-scale fillers compared to that filled with micro-scale particles. The friction and wear resistance of these composites is found to increase with increasing filler concentration. It is also possible to use multi-functional fillers to develop high performance composites which cannot be achieved by using a single filler.
An Antilock-Braking Systems (ABS) Control: A Technical Review  [PDF]
Ayman A. Aly, El-Shafei Zeidan, Ahmed Hamed, Farhan Salem
Intelligent Control and Automation (ICA) , 2011, DOI: 10.4236/ica.2011.23023
Abstract: Many different control methods for ABS systems have been developed. These methods differ in their theoretical basis and performance under the changes of road conditions. The present review is a part of research project entitled “Intelligent Antilock Brake System Design for Road-Surfaces of Saudi Arabia” In the present paper we review the methods used in the design of ABS systems. We highlight the main difficulties and summarize the more recent developments in their control techniques. Intelligent control systems like fuzzy control can be used in ABS control to emulate the qualitative aspects of human knowledge with several advantages such as robustness, universal approximation theorem and rule-based algorithms.
Salvage use of activated recombinant factor VII in the management of refractory bleeding following cardiac surgery
Barua A, Rao VP, Ramesh BC, Barua B, El-Shafei H
Journal of Blood Medicine , 2011, DOI: http://dx.doi.org/10.2147/JBM.S21609
Abstract: lvage use of activated recombinant factor VII in the management of refractory bleeding following cardiac surgery Case Series (2328) Total Article Views Authors: Barua A, Rao VP, Ramesh BC, Barua B, El-Shafei H Published Date September 2011 Volume 2011:2 Pages 131 - 134 DOI: http://dx.doi.org/10.2147/JBM.S21609 Anupama Barua1, Vinay P Rao1, BC Ramesh2, Biplab Barua3, Hussain El-Shafei2 1Cardiothoracic Department, Nottingham City Hospital, Nottingham, UK; 2Cardiothoracic Department, Aberdeen Royal Infirmary, Aberdeen, UK; 3General Surgery Department, Glenfield Hospital, Glenfield, Leicester, UK Background: Refractory post cardiopulmonary bypass (CPB) bleeding continues to cause concern for cardiac surgeons and intensivists. Massive postoperative hemorrhage following CPB is multifactorial and not fully understood, and it is also associated with increased mortality and morbidity. Activated recombinant factor VII (rFVIIa) has emerged as possible salvage medication in refractory post cardiac surgical bleeding. This observational study sought to identify the pattern of use of rFVIIa in cardiac surgery, its effectiveness, and risk. Methods: This study involved a retrospective case review of medical records of ten patients undergoing a variety of cardiac surgery procedures and who developed life-threatening bleeding during surgery or after surgery despite conventional medical therapy, including transfusion of blood and blood products, and received rFVIIa at a regional center between August 2007 and April 2009. Results: All ten patients received two consecutive doses of rFVIIa (average dose 65 μg/kg) at a 2-hour interval. Eight patients were re-explored due to massive postoperative bleeding or cardiac tamponade before receiving rFVIIa. Surgical sources of bleeding were not identified in any cases. A second re-exploration was carried out in two cases. Two patients (20%) died in ITU from problems not related to bleeding and thromboembolism. Blood loss was significantly reduced after administration of rFVIIa. Blood loss 6 hours prior to treatment was 1758.5 ± 163.9 mL and blood loss in the 6-hour period post treatment was 405.6 ± 50.5 mL (P < 0.05). Blood and blood products used in the 6-hour period before and after administration of rFVIIa were 19.6 ± 1.5U and 4.4 ± 0.6U, respectively (P < 0.05). No adverse reactions or thrombotic complications related to rFVIIa were noted. Conclusion: In our limited study, use of rFVIIa in refractory post surgical bleeding was significantly reduced blood loss and use of blood and blood products. We concluded that rFVIIa can be used satisfactorily and safely as a rescue therapy in the management of post cardiac surgical bleeding.
Synthesis and Photophysical Properties of Novel Highly Stable Zero/Bis-Zero Methine Cyanine Dyes Based on N-Bridgehead Heterocycles  [PDF]
Ahmed I. Koraiem, Islam M. Abdellah, Ahmed M. El-Shafei
International Journal of Organic Chemistry (IJOC) , 2018, DOI: 10.4236/ijoc.2018.83021
Abstract: Cyanine dyes of zero/bis-zero methine incorporating imid-azo(1,2-a)Pyridine (quinoline) or pyrazino(1,2-a)pyridine (quinoline) with stable C-N bond were synthesized using keto-oxime methylene C-link heterocyclic quaternary salts [1-phenyl-3-methyl-pyrazolino-4-keto-oxime-α-methylene-bis-pyridin-(quinoin)-1(4)-di-ium-iodide(ethiodide) salts and 1-phenyl-3-methyl-pyrazolino- 4-ketooxime-α-methylene-N-2-methyl-bis pyridin (quinoin)-1(4)-di-ium-iodide(ethiodide) salts]. Such heterocyclic precursors and related dyes were identified by elemental and spectral analyses. The absorption spectra properties of such dyes were investigated in 95% Ethanol to attempt and throw some light on the influence of such new heterocyclic nuclei and to compare or evaluate spectral behaviors. The absorption spectra of dyes in different pure solvents were examined in the visible region showing solvatochromism and the colour changes of dyes with solvents having different polarities. This permits a selection of the optimal solvent (fractional solvent) when such dyes are applied as photosensitizers. The spectral behavior of some selected newly synthesized cyanine dyes is observed in mixed solvents of different polarities and progressively increasing quantities of one solvent over the other were studied and showed an increase in the absorbance of CT band with increasing proportion of that solvent. Evidence for hydrogen bond formation between the solute molecules and solvent molecules allows measurement of certain energies such as hydrogen bonding, orientation, and free energies.
Wadi Fatima Thin-Skinned Foreland FAT Belt: A Post Amalgamation Marine Basin in the Arabian Shield  [PDF]
Zakaria Hamimi, Mohamed Matsah, Mohamed El-Shafei, Abdelhamid El-Fakharani, Abdulrahman Shujoon, Majid Al-Gabali
Open Journal of Geology (OJG) , 2012, DOI: 10.4236/ojg.2012.24027
Abstract: Wadi Fatima fold-thrust (FAT) belt is a distinctive foreland FAT belt in the Arabian-Nubian Shield (ANS) involving unmetamorphosed to slightly metamorphosed sedimentary sequence of Fatima Group, deposited over a metamorphic/igneous basement, comprising ortho-amphibolites, orthoand para-schists (with chaotic unmappable blocks of marbles, pyroxenites and metagabbros), older granite (773 ± 16 Ma) and younger granite. The basement exhibits structural fabrics, such as attenuated tight isoclinal folds, sheared-out hinges, NE-SW penetrative foliation and subhorizontal stretched and mineral lineations, related to an oldest prominent dextral shearing phase affected the main Wadi Fatima during the Neoproterozoic. In Wadi Fatima FAT belt, the style of deformation encompasses flexural-slip folding forming mesoscopicand map-scales NE to ENE plunging overturned antiforms and synforms, and a thrust duplex system bounded by floor thrust and sole thrust (basal detachment) dipping gently towards the hinterland (SE to SSE direction) and rises stratigraphically upwards towards the foreland. Such style is affiliated to thin-skinned deformation. Several lines of evidence, such as geometry of interacting outcropand map-scale folds and thrusts, patterns of thrust displacement variations and indications for hinge migration during fold growth, strongly suggest that folding and thrusting in Wadi Fatima FAT belt are geometrically and kinematically linked and that thrusting initiated as a consequence of folding (fold-first kinematics). Thrusts frequently show flat-ramp-flat geometry, and every so often give an impression that they are formed during two main sub-stages; an older sub-stage during which bedding sub-parallel thrusts were formed, and a younger sub-stage which generated younger ramps oblique to bedding. Thrust ramps with SE to SSE dipping regularly show sequential decrease in dip or inclination (due to piggy-back imbrication) into their transport direction which is proposed to be towards NW to NNW. Evidence indicating this transport direction of Wadi Fatima FAT belt embrace NW to NNW oriented stretching lineations recorded along thrust planes, NW to NNW folding vergence, and diminishing of the intensity of deformation and thrust stacking and imbrication from SE to NW; i.e. from hinterland to foreland. The tectonic transport vector is congruent with the mean orientation of slickenline striae formed by layer-parallel slipping along folded bedding planes. The mean orientation of slickenline lineations, after their host beds were rotated to horizontal about their
-Closed and -Closed in -Topological Spaces
M. E. El-Shafei,A. H. Zakari
International Journal of Mathematics and Mathematical Sciences , 2011, DOI: 10.1155/2011/853870
Abstract: We investigate various classes of generalized closed fuzzy sets in [0,1]-topological spaces, namely, -closed fuzzy sets and -closed fuzzy sets. Also, we introduce a new separation axiom ?3/4 of the [0,1]-topological spaces, and we prove that every ?3/4-space is a 3/4-space. Furthermore, we using the new generalized closed fuzzy sets to construct new types of fuzzy mappings.
Crossplasty: An Alternative Technique for Closing Double Defects
Ibrahim K. Al Aradi and Wael M. El-Shafei
Clinical Medicine Insights: Dermatology , 2012,
Abstract: Crossplasty is a modified O-T advancement flap. It is an alternative technique to close double surgical defects, which are arranged in a vertical line. It is useful to camouflage the scar in forehead parallel lines. Geometrically, it is an inverted T joined to a vertical linear defect. There are three important pre-requisites to this technique: an extensive undermining to all flap limbs, excision of the middle zone normal skin and the purse string stitch of the central zone of the flap.
$ S$-Cluster Sets in Fuzzy Topological Spaces
A. A. Nouh,M. E. El-Shafei
Tamkang Journal of Mathematics , 2002, DOI: 10.5556/j.tkjm.33.2002.233-240
Abstract: In this paper the concept of $ S$-cluster fuzzy sets, of fuzzy functions and fuzzy multifunctions between fuzzy topological spaces is introduced. As an application, characterizations of fuzzy Hausdorff and $ SQ_alpha$-closed fuzzy topological spaces are achieved via such cluster fuzzy sets.
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