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Search Results: 1 - 10 of 462438 matches for " AbdAllah A. Alshennawy "
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Intelligent Vision Methodology for Detection of the Cutting Tool Breakage
Abdallah A. Alshennawy,Ayman A. Aly
International Journal of Information Technology and Computer Science , 2013, DOI: 10.5815/ijitcs.2013.06.06
Abstract: In this paper, a new Intelligent system based on neurofuzzy for detecting and diagnostics the wear and damage of the milling cutter is presented. The compatibility between the computer vision and neurofuzzy techniques is introduced. The proposed approaches consists of capturing the milling cutter image, Fuzzy edge detection, Chain code technique for feature extraction and finally, apply the neural network on the feature. The results of the study are three different diagnostics models, The first is diagnostic model for the original profile of the perfect cutter, the second is model for the wearied profile and the third is model for the damage profile. Experimental test results show that the proposed system is reliable, practical and can be used for the easy distinguish between the wear and damage automatically.
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.
Sexual Transmission of HCV in Heterologous Monogamous Spouses
Mona M. Rafik,Yehia El Shazly,Amal A. Abbas,Walid Abd Elhady,Dina Ragab,Dina AlShennawy
Journal of Sexually Transmitted Diseases , 2014, DOI: 10.1155/2014/140640
Abstract: We screened for evidence of HCV infection in healthy heterologous monogamous spouses of chronic HCV patients and studied the relation with various risk factors. A cross-sectional study of fifty healthy monogamous heterosexual spouses of HCV-positive index cases was carried out. All participants were HBV and HIV negative. The association with various risk factors was studied. Five spouses (10%) showed evidence of HCV infection. Two partners were positive for HCV antibody alone (4%) and 3 for antibody and HCV PCR (6%). No association was found between HCV infection and various sociodemographic parameters with the exception of older age categories. Intraspousal transmission of HCV may be an important source of spread of HCV infection. The reservoir of HCV-infected individuals in Egypt is sizable, and sexual transmission of HCV may contribute to the total burden of infection in Egypt. 1. Introduction The extent to which HCV infection is associated with sexual exposure has been debated extensively. The 2008 Egyptian Demographic and Health Survey [1] estimated that 15% of people aged 15–59 years in Egypt have anti-HCV antibodies and 10% have chronic HCV infection. However, this high figure is related to past transmission events and is not representative of the HCV transmission occurring in Egypt. Sexual transmission of HCV may contribute to the total burden of infection in Egypt. The objectives of this study were to detect the risk for sexual transmission of HCV infection from chronically infected subjects to their long-term monogamous heterosexual partners (50 spouses) and to identify various sexual practices associated with that risk. Spouses were carefully selected to exclude risk factors and participants were HBV (HBsAg, HBcAb, and HBsAb) and HIV antibody negative. All participants were tested for liver enzymes, HCV specific antibodies (Ortho Clinical Diagnostics, New Jersey, USA), and HCV RNA assay with real-time PCR using Qiagen extraction kit and Brilliant HCV QRT-PCR for Stratagene’s Mx3000P. Five spouses showed evidence of HCV infection, two were positive for HCV antibody alone (4%) and three were positive for HCV antibody and HCV PCR (6%). No association was found between the HCV infection status and various selected risk factors such as sex, age, duration of marriage, frequency of sexual intercourse, history of sexually transmitted diseases, and other risk factors for HCV. The only association detected was the age category where both positivity of HCV antibody and HCV PCR were associated with the older age category (>60?y). As regards the direction
Different Feeding Techniques of Microstrip Patch Antennas with Spiral Defected Ground Structure for Size Reduction and Ultra-Wide Band Operation  [PDF]
Dalia M. Elsheakh, Esmat A. Abdallah
Journal of Electromagnetic Analysis and Applications (JEMAA) , 2012, DOI: 10.4236/jemaa.2012.410056
Abstract: Different feeding techniques of microstrip patch antennas with different spiral defected ground structures are presented in this paper. The investigated structures illustrate some merits in designing multi-electromagnetic band-gap structures by adjusting the capacitance and changing the inductance through varying the width and length of spiral defected ground structure. Then by applying the three different spirals shapes (one, two and four arms) as the ground plane of microstrip patch antenna with different feeding techniques to create multi or ultra wide-band, improve the antenna gain and reduce the antenna size, it is found that the four arms spiral defected ground structure of microstrip patch antenna with offset feed gives good performance, electrical size reduction to about 75% as compared to the original patch size and ultra-wide bandwidth extends from 2 GHz up to 12 GHz with ?8 dB impedance bandwidth.
Molecular Relationships among Different Seryian Aegilops Species (Poaceae)  [PDF]
Abdallah M. Sliai, Sayed A. M. Amer
Natural Resources (NR) , 2013, DOI: 10.4236/nr.2013.41009
Abstract:

Aegilops has been considered a complex genus with as many as 22 species in Syria. The current study has used 585 nucleotides from 5.8S nuclear ribosomal DNA gene and internal transcribed spacer 2 for these different species. These data were aligned manually and subjected to bioinformatics manipulation in order to construct the genetic relationship among these species. Three statistical methods (maximum-parsimony-MP, maximum-likelihood-ML and neighborjoining-NJ) were used to execute the most likely relationship. The constructed genetic relationship showed homogeneinty in clustering of the species of the same plant type (A, B or C) with each other. A single NJ tree and a single ML tree were obtained with slight difference in topology within each plant type. Both trees disagreed with our previous finding in that A. searsii, speltoides and A. longissima clustered in one group and the first two species were sisters while A. caudata was out. Therefore, A. speltoides was not the oldest among them and these differences could be related to the difference in taxon sampling size. This study, however, supported our previous molecular finding and did not support the previous karyotypic study in that A.

Ultra-Wideband Log Periodic Dipole Antenna (LPDA) for Wireless Communication Applications  [PDF]
Dalia N. Elsheakh, Esmat A. Abdallah
Journal of Electromagnetic Analysis and Applications (JEMAA) , 2018, DOI: 10.4236/jemaa.2018.106009
Abstract: This paper proposes a printed log-periodic dipole antenna (LPDA) for ultra wide bandwidth (UWB) applications. The antenna comprises of cascading four U shaped elements of different line lengths with balun circuit to improve the antenna impedance matching. The proposed antenna dimensions are 50 × 50 mm2 with FR4 substrate thickness 0.8 mm. Full-wave EM solver HFSS (High Frequency Structure Simulator) is used for modeling the proposed antenna. The pulse distortion is verified by the measured the proposed antenna performance with virtually steady group delay. The simulation and experimental results show that the proposed antenna exhibits good impedance matching, stable radiation patterns throughout the whole operating frequency bands, acceptable gain and stable group delay over the entire operating band. An UWB extended from 1.85 GHz to 11 GHz is obtained, and the average antenna gain is about 5.5 dBi over the operating band with peak gain around 6.5 dBi and 70% average radiation efficiency.
Impact of Methyl Jasmonate on Antioxidant Activity and Some Biochemical Aspects of Maize Plant Grown under Water Stress Condition  [PDF]
Z. A. Abdelgawad, A. A. Khalafaallah, M. M. Abdallah
Agricultural Sciences (AS) , 2014, DOI: 10.4236/as.2014.512117
Abstract: A pot-culture study was undertaken to investigate the possible role of Methyl jasmonate (MeJA)-treatment on the earlier vegetative growth stage and different chemical constituents of maize cultivar (Giza-2) plants subjected to water stress. The grains were divided into two groups: first group was pre-soaked in water, and the second one was pre-soaked in 50 μM MeJA for 8 h. The plants were subjected to different levels of water field capacity (WFC) 65%, 55% and 45%. The results showed that pre-soaking maize grains with MeJA led to increases in plant growth criteria evident in terms of plant height, fresh and dry weight of plant. The pigment levels concomitantly with total carbohydrates, total soluble sugar, polysaccharides, as well as free amino acids, proline and total protein content were markedly increased. Moreover, the application of the investigated MeJA significantly improved growth hormone in terms of IAA. In contrast ABA level was markedly declined in maize plant. The activities of oxidative CAT, POX and SOD were also increased with MeJA. In addition, the N, P and K content was increased significantly in shoot. As a conclusion, soaking maize grains with MeJA could alleviate the harmful effects of water stress.
On the numerical treatment of the contact problem
Abdallah A. Badr
International Journal of Mathematics and Mathematical Sciences , 2000, DOI: 10.1155/s0161171200003215
Abstract: The problem of the contact of two elastic bodies of arbitrary shape with a kernel in the form of a logarithmic function—which is investigated from Hertz problem—is reduced to an integral equation. A numerical method is adapted to determine the pressure between the two surfaces under certain conditions.
Block-by-Block Method for Solving Nonlinear Volterra-Fredholm Integral Equation
Abdallah A. Badr
Mathematical Problems in Engineering , 2010, DOI: 10.1155/2010/537909
Abstract: We consider a nonlinear Volterra-Fredholm integral equation (NVFIE) of the second kind. The Volterra kernel is time dependent, and the Fredholm kernel is position dependent. Existence and uniqueness of the solution to this equation, under certain conditions, are discussed. The block-by-block method is introduced to solve such equations numerically. Some numerical examples are given to illustrate our results. 1. Introduction Different methods are used to solve integral equations which are investigated from many physical applications such as the mixed problems in the theory of elasticity. Popov [1] applied the orthogonal polynomials method to solve the mixed problem in the mechanics of continuous media. Badr [2] applied Toeplitz matrix method to solve a NVFIE. Abdou et al. [3] discussed the solution of Harmmerstein-Volterra integral equation of the second kind. In [4], Haci obtained, numerically, the solution of a system of Harmmerstein integral equations in the space . The equivalence between Volterra integral equation with degenerate kernel and a linear system of differential equations is mentioned by Cochran [5]. Although there are some works on Hermite-type collocation method for the second-kind VIEs with smooth kernels, not too many studies have dealt with weakly singular kernel. For example, Papatheodorou and Jesanis [6] used the collocation method and obtained the solution of Volterra integrodifferential equation with weakly singular kernels. More information about different analytical and numerical solutions of Volterra equations can be found in Davis [7], Linz [8], Volterra [9], and Wolkenfelt [10]. In this paper, we consider the following NVFIE: The existence of a unique solution for the above equation, under certain conditions, is granted using fixed point theorem, where is the Fredholm kernel and is the Volterra kernel. is called the free term, and the unknown function, , is called the potential function in the applied mathematics, and it will be determined. Both two functions and are assumed in the same space. The parameter has many physical meanings. A numerical method is applied to this equation, and it is reduced it to a system of Volterra integral equations of the second kind. Finally, the block-by-block method is used to obtain the numerical solution of this system. Some examples are stated to illustrate the results. 2. Existence and Uniqueness of Solution To guarantee the existence and uniqueness of solution to (1.1), we write (1.1) in the integral operator form where Also, we assume the following conditions: (i) and satisfies, in
Finite Element Method for Linear Multiterm Fractional Differential Equations
Abdallah A. Badr
Journal of Applied Mathematics , 2012, DOI: 10.1155/2012/482890
Abstract: We consider the linear multiterm fractional differential equation (fDE). Existence and uniqueness of the solution of such equation are discussed. We apply the finite element method (FEM) to obtain the numerical solution of this equation using Galerkin approach. A comparison, through examples, between our techniques and other previous numerical methods is established.
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