OALib Journal期刊

ISSN: 2333-9721




2018 ( 371 )

2017 ( 666 )

2016 ( 953 )

2015 ( 13707 )


匹配条件: “ Hamdy M. Husein” ,找到相关结果约400415条。
A Modified Limberg Flap versus Z Plasty Flap Technique in Management of Recurrent Pilonidal Disease: A Comparative Prospective Study  [PDF]
Asmaa Gaber R., Mohamed Yousef A., Mohamed Abdel Shafy Mohamed, Abd-El-Aal A. Saleem, Hassan A. Abdallah, Hamdy M. Husein
Open Access Library Journal (OALib Journal) , 2018, DOI: 10.4236/oalib.1104715
Background: There are controversies about the etiology and management of recurrent pilonidal sinus. The numbers of techniques are testament in treating pilonidal sinus (PNS) and no single procedure is superior in all aspects. Aim of the study: The aim of this study was to compare two operative procedures (modified Limberg flap versus Z plasty flap) in management of recurrent pilonidal sinus, regarding their complications including recurrences of the disease, morbidity, hospital stay, day off work and postoperative complications. Patients and methods: This is comparative prospective study between modified Limberg flap and Z plasty flap in treatment of recurrent pilonidal sinus. 30 patients were divided into 2 groups: Group (1) treated with modified Limberg flap and group (2) treated with Z plasty, and we followed up the patients in both groups for postoperative complications, hospital stay, day off work, recurrences, patients satisfactions. Results: Operative time, hospital stay duration, complete wound healing was longer in group (2) Z plasty group. Mobilization was early in MLF group than Z plasty group (1 day versus 2 days). Time to return to work, it was 14 (12 - 16) days in MLF groups and 18 (15 - 22) in Z plasty group (p < 0.001). Infection occurred only in one in MLF group (1) and 2 patients in Z plasty group (2). The mean time for complete healing of the wound after Modified Limberg flap group (1) was 16 ± 4.2 days while in Z plasty group (2) it was 22 ± 6.8 days. Satisfaction score was better in MLF group (1). Recurrence hadn’t occurred in any of the patients included in this study during the follow-up period. Conclusion: Both of modified Limberg flap and Z-plasty technique are used to cause flattening of the natal cleft, thus reducing local recurrence rates. So, we recommend use of flap technique for recurrent pilonidal sinus patients; modified Limberg transposition flap is better than Z plasty flap, because of the less hospital stay time, early return to work, and cosmetically more accepted as it has less postoperative complications. Also Z plasty flap has a major limitation as it is difficult to apply if there is a wide defect in the horizontal axis.
Vibration of Nano Beam Induced by Ramp Type Heating  [PDF]
Hamdy M. Youssef, Khaled A. Elsibai
World Journal of Nano Science and Engineering (WJNSE) , 2011, DOI: 10.4236/wjnse.2011.12006
Abstract: The non-Fourier effect in heat conduction and the coupling effect between temperature and strain rate, became the most significant effects in the nano-scale beam. In the present study, a generalized solution for the generalized thermoelastic vibration of a bounded nano-beam resonator induced by ramp type of heating is developed and the solutions take into account the above two effects. The Laplace transforms and direct method are used to determine the lateral vibration, the temperature, the displacement, the stress and the energy of the beam. The effects of the relaxation time and the ramping time parameters have been studied with some comparisons.
On Some Fractional Stochastic Integrodifferential Equations in Hilbert Space
Hamdy M. Ahmed
International Journal of Mathematics and Mathematical Sciences , 2009, DOI: 10.1155/2009/568078
Abstract: We study a class of fractional stochastic integrodifferential equations considered in a real Hilbert space. The existence and uniqueness of the Mild solutions of the considered problem is also studied. We also give an application for stochastic integropartial differential equations of fractional order.
Boundary Controllability of Nonlinear Fractional Integrodifferential Systems
Hamdy M. Ahmed
Advances in Difference Equations , 2010, DOI: 10.1155/2010/279493
Abstract: Sufficient conditions for boundary controllability of nonlinear fractional integrodifferential systems in Banach space are established. The results are obtained by using fixed point theorems. We also give an application for integropartial differential equations of fractional order.
Euler-Maruyama Numerical solution of some stochastic functional differential equations
Hamdy M. Ahmed
International Journal of Applied Mathematics and Computation , 2009,
Abstract: In this paper we study the numerical solutions of the stochastic functional differential equations of the following form $du(x,t) = f(x,t,u_t)dt + g(x,t,u_t)dB(t),~ t>0$ with initial data $u(x,0)= u_0(x)=xi in L^p_{F_0}([- au,0];R^n)$ Here $x in R^n$ ($R^n$ is the $ u$-dimenional Euclidean space), $f: C([- au,0]; R^n ) imes R^{ u + 1} ightarrow R^n$ $g: C([- au,0];R^n) imes R^{ u + 1} ightarrow R^{n imes m } u(x,t)in R^n$ for each $t$, $u_t = {u(x,t+ heta ):- auleq hetaleq 0}in C([- au,0];R^n)$ and $B(t)$ is an m-dimensional Brownian motion.
Fractional Order Generalized Thermoelastic Infinite Medium with Cylindrical Cavity Subjected to Harmonically Varying Heat  [PDF]
Hamdy M. Youssef, Eman A. Al-Lehaibi
Engineering (ENG) , 2011, DOI: 10.4236/eng.2011.31004
Abstract: In this work, a mathematical model of an elastic material with cylindrical cavity will be constructed. The governing equations will be taken into the context of the fractional order generalized thermoelasticity theory (Youssef 2010). Laplace transform and direct approach will be used to obtain the solution when the boundary of the cavity is exposed to harmonically heat with constant angular frequency of thermal vibration. The inverse of Laplace transforms will be computed numerically using a method based on Fourier expansion techniques. Some comparisons have been shown in figures to present the effect of the fractional order parameter and the angular frequency of thermal vibration on all the studied felids.
Generalized Thermoelasticity Problem of Material Subjected to Thermal Loading Due to Laser Pulse  [PDF]
Hamdy M. Youssef, Ahmed S. Al-Felali
Applied Mathematics (AM) , 2012, DOI: 10.4236/am.2012.32022
Abstract: This work is devoted to a study of the induced temperature and stress fields in an elastic half space in context of clas-sical coupled thermoelasticity and generalized thermoelasticity in a unified system of equations. The half space is con-sidered to be made of an isotropic homogeneous thermoelastic material. The bounding plane surface is heated by a non-Gaussian laser beam with pulse duration of 2 ps. An exact solution of the problem is first obtained in Laplace transform space. Since the response is of more interest in the transient state, the inversion of Laplace transforms have been carried numerically. The derived expressions are computed numerically for copper and the results are presented in graphical form.
Environmental and Mineralogical Studies of the Sabkhas Soil at Ismailia—Suez Roadbed, Southern of Suez Canal District, Egypt  [PDF]
Mohamed M. El-Omla, Hamdy A. Aboulela
Open Journal of Geology (OJG) , 2012, DOI: 10.4236/ojg.2012.23017
Abstract: Eight surface sabkha soils samples were collected from Ismailia—Suez roadbed, southwestern of Suez Canal district. Sedimentological and mineralogical analyses were conducted using grain size; X-ray diffraction and Scanning Electron Microscopy (SEM). Grain size analysis indicates high contents of fine sand and mud as well as presence of salts. X-ray diffraction; Scanning Electron Microscopy (SEM) and EDAX tool clarified that the sabkha soils are enriched by quartz, sulfate minerals (gypsum, anhydrite), carbonate minerals (calcite-dolomite-aragonite), chlorides (halite and bischofite), and clay minerals. The results elucidate that the appearance of sabkha deposits and their distribution in the study area are controlled mainly by the content of water soluble salts through parent materials; ground water table; subsurface structural; and physiographic features for instance surface relief or topography; and human activity.
Pathogenic Bacteria Associated with Different Public Environmental Sites in Mecca City  [PDF]
Samy S. Ashgar, Hamdy M. El-Said
Open Journal of Medical Microbiology (OJMM) , 2012, DOI: 10.4236/ojmm.2012.24020
Abstract: Background: The hygiene of environmental surfaces from shopping, ATM machines, telephones and computers and miscellaneous sites play role in spreading fecal and total coliform bacteria as well as pathogenic bacteria. Objectives: This study addresses the contaminated common sites by pathogenic or potentially pathogenic bacteria in Mecca, SA. Materials and Methods: A total 648 swab samples were collected and analyzed for presence or absence of pathogenic bacteria. Results: Of the total samples 422 were negative bacterial count (71%) and 226 (29%) were positive. All collected samples (100%) of glass windows in the fish markets were bacterial counted; most dominated was Bacillus spp. (n = 97) and the highest population of species was Enterococcus faecalis (n = 40) and E. coli (n = 16). Conclusion: Some public sites were very contaminated with different types of fecal coliform group of bacteria such as shopping cart handles, inner surfaces and child seats in supermarkets, and the glass windows in the fish market. Acinetobacter haemolyticus and other hemolytic bacteria were isolated from more than site.
Vibration of Gold Nano-Beam with Variable Young’s Modulus Due to Thermal Shock  [PDF]
Eman A. N. Al-Lehaibi, Hamdy M. Youssef
World Journal of Nano Science and Engineering (WJNSE) , 2015, DOI: 10.4236/wjnse.2015.54020
Abstract: In this paper, we will study the most important effects in the nano-scale resonator: the coupling effect of temperature and strain rate, and the non-Fourier effect in heat conduction. A solution for the generalized thermoelastic vibration of nano-resonator induced by thermal loading has been developed. The Young’s modulus is taken as a linear function of the reference temperature. The effects of the thermal loading and the reference temperature in all the studied fields have been studied and represented in graphs with some comparisons. The Young’s modulus makes significant effects on all the studied fields where the values of the temperature, the vibration of the deflection, stress, displacement, strain, stress-strain energy increase when the Young’s modulus has taken to be variable.

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