OALib Journal期刊

ISSN: 2333-9721



匹配条件: “Elsayed” ,找到相关结果约264条。
Transit-Time Flow Measurement: Letter to The Editor  [PDF]
Elsayed Elmistekawy
Open Journal of Thoracic Surgery (OJTS) , 2012, DOI: 10.4236/ojts.2012.22007
Abstract: Transit-time flow technology is considered as a quality of care in bypass surgery especially in off pump revascularization. Transit time flow measurement is a real time, direct, easy and handy tool for assessment quality of anastomosis and graft blood flow.
Sequential Observation and Control of Robotic Systems Subjected to Measurement Delay and Disturbance  [PDF]
ElSayed ElBeheiry
Intelligent Control and Automation (ICA) , 2012, DOI: 10.4236/ica.2012.34034
Abstract: An approach for motion control and observation of robotic manipulators is presented in this article. It links the design of a joint acceleration controller to the design of a variable structure observer including Luenberger-like observation term. Both the joint acceleration controller and the observer that are introduced in this paper are very likely to use either large or moderate or small gains. Thus the time delay issue of the output measurements is highly taken into consideration in the design of the intended observers. The observer design is therefore based on two different generalized forms of nonlinear systems with/without undelayed outputs. A study to investigate the effects of the gains of the joint acceleration controller on the performance capabilities of the observer is introduced. Also, the effects of the time delay factor on the operation of both the controller and the observer and their own interaction are studied. Then a chain observer design is presented for circumventing the time delay effects. The time delay constant is found to be of vital importance to the robot performance capabilities. Moreover, the results show that the gains of the joint acceleration controller are of significant influence on the operation of the proposed observers.
Generalized Thermo Elasticity in an Infinite Nonhomogeneous Solid Having a Spherical Cavity Using DPL Model  [PDF]
Ahmed Elsayed Abouelrega
Applied Mathematics (AM) , 2011, DOI: 10.4236/am.2011.25083
Abstract: The induced temperature, displacement, and stress fields in an infinite nonhomogeneous elastic medium having a spherical cavity are obtained in the context dual-phase-lag model. The surface of the cavity is stress free and is subjected to a thermal shock. The material is elastic and has an in¬homogeneity in the radial direction. The type of non homogeneity is such that the elastic constants, thermal conductivity and density are propor¬tional to the nth power of the radial distance. The solutions are obtained analytically employing the Laplace transform technique. The numerical inversion of the transforms is carried out using Fourier series expansions. The stresses, temperature and displacement are computed and presented graphically. A comparison of the results for different theories is presented.
On the Quantum Statistical Distributions Describing Finite Fermions and Bosons Systems  [PDF]
Elsayed K. Elmaghraby
Journal of Modern Physics (JMP) , 2011, DOI: 10.4236/jmp.2011.211154
Abstract: A century old methodology for deriving statistical distribution using approximate Stirling’s formulation of the factorial becomes questionable. By avoiding the use of exaggerated approximations, a new picture of the energy distribution of fermions and bosons are presented. Energy distribution among fermions (or bosons) in systems with finite degeneracy are found to be degeneracy dependent. The presented point of view explains, successfully, presence of degeneracy pressure in ultra-cooled Fermi gas and predicts the minimum accessible temperature for finite degeneracy fermions system.
Fixation of subtrochanteric fractures
Elsayed Ibraheem Elsayed Massoud
Strategies in Trauma and Limb Reconstruction , 2009, DOI: 10.1007/s11751-009-0058-z
Abstract: The subtrochanteric region has certain anatomical and biomechanical features that can make fractures in this region difficult for the treating surgeon. The preferred type of device is a matter of debate. Increased understanding of mechanical characteristics of the dynamic hip screw (DHS) has reduced the incidence of complications. Our hypothesis is based on the technical optimization of the DHS application. We prospectively studied 37 patients with subtrochanteric fractures with a mean age of 42.9 years. We utilized a two-stage protocol: initially, conversion of the comminuted fractures into two part fractures; then application of the implant with a technique that allowed dynamization of the DHS. Clinical and radiographic data were used to assess the outcome at 12 months. Fracture healing was obtained for all cases in a mean time of 11.64 weeks. One patient had 1.5 cm shortening of the injured limb. No implant failure was reported. All patients resumed pre-injury activities of daily living. It was concluded that the patients who were treated with the technical optimization of the DHS application achieved a close-to-normal anatomy following surgery and maintained this state throughout the follow-up period.
Elsayed Hussein Elsayed Ali
Journal on Efficiency and Responsibility in Education and Science , 2010,
Abstract: Information and Communication Technology (ICT) has made life much different than it was before especially in Education. E learning is becoming increasingly prominent in higher education, with universities increasing provision and more students signing up. E learning in the university context is influenced by a number of factors. However, the researcher particular interest in this paper in the e readiness of the staff memberfor e learning at the Egyptian faculties of tourism and hotels in Fayoum, Menia, Helwan and Alex. This is to the increasing and flexible market that is difficult to research by only traditional education.This research measures the staff members’ e readiness for e learning at the faculties of tourism and hotels in Egypt which influenced by a number of factors and dimensions. These are technical and pedagogical competences, experience scale and attitude Scale but the research will concentrate on the first dimension. This may help Tourism faculties to promote the use of IT in teaching and learning and also apply e learning effectively in these faculties to make qualified students for market work. Data was collected through a questionnaire of 92 staff member (professor, assistant professor and lecturers) of tourism studies, hotel management and Tourism Guidance departments. Also this research is based on a basic hypothesis that there is a shortage and insufficient of staff members e readiness for e learning. The paper contains also typical e learning quality framework , SPSS program was used to analyses the data and reach to the finding of this study as frequencies, standard deviation, means, t test per pair between the two dimension pedagogical and technical competencies, also average mean to measure this dimension, also cronbach alpha was made to ensure the reliability, beside the validity was been achieved. The findings have been indicated that the staff member at faculties of tourism and hotels have a good level in pedagogical factor and have a bad or shortage in technical factor, so the paper has recommended them to improve their technical competencies.
Fixation of intracapsular femoral neck fractures: Effect of trans-osseous capsular decompression
Elsayed Ibraheem Elsayed Massoud
Dicle Medical Journal , 2010,
Abstract: Objectives: Intracapsular femoral neck fractures have been found as associated with hemarthrosis. The fluid in the intact capsule elevates the intracapsular pressure to a level could tamponades the vascular supply of the femoralhead. Therefore, capsular decompression seems necessaryto salvage the femoral head circulation. Negative impact of the capsular incision also has been reported. Therefore, we hypothesize that creation of a trans-osseousportal can decompress the capsule as well as not threaten the capsular related blood vessels.Materials and methods: In present study, 27 patients with intracapsular femoral neck fractures were included. Coinciding with closed reduction and internal fixation we made a trans-osseous portal for capsular decompression. Patients were followed-up prospectively for a mean periodof 43.1 months.Results: All fractures united. However, one patient 17 years-old who was nursed preoperatively in skin traction developed osteonecrosis of the femoral head.Conclusion: Our results supported that the trans-osseous capsular decompression has evacuated the intracapsular haematoma and has not threatened the capsular integrity. Preoperative traction of the injured limb particularly in the young patient may play a role in development of osteonecrosisof the femoral head.
Fractured patella in children: Preservation of the patellar dimensions
Elsayed Ibraheem Elsayed Massoud
Dicle Medical Journal , 2012,
Abstract: Objectives: The progressive understanding of the mechanicalfunction of the patella makes preservation of itsgeometry is mandatory, particularly during its reconstruction.Objectives of this study were to compare the patellardimensions after surgical and conservative treatment forpatellar fractures in children and to present influence ofthe changes in the patellar dimensions on the knee motions.Materials and methods: Two groups of children with patellarfractures their ages at time of injury averaged 12years. One group included five children, was treated surgicallyusing of the inter-fragmentary wiring technique andthe other group that includes seven children was treatedconservatively. Patients were prospectively followed for aperiod-averaged 65.5 months, the knee function and thepatellar dimensions were assessed clinically and radiographically.Results: The group was treated surgically reported insignificantincrease in the patellar longitudinal length andreported no extension lag; however, reported average 9°flexion deficit, which is possibly correlated to radiographicincrease of the patellar thickness. The group was treatedconservatively reported significant increase in the patellarlongitudinal length and reported extension lag averaged4.3° and flexion deficit averaged 7.14°.Conclusions: Surgical treatment preserved to great extentthe longitudinal patellar length but it failed to preservethe patellar thickness particularly in the comminuted patellarfractures. The patellar elongation caused extensionlag and flexion deficit while the mere increase of the patellarthickness produced flexion deficit without extensionlag.Key words: Patella, dimensions, fracture, knee motion,children
The Holy Month of Ramadan: the Lantern, the Cannon and the Drummer :
Elsayed Saad
Historical Kan Periodical , 2008,
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A Historical Eye on the Anniversary of Prophet Muhammad's Birth
Elsayed Saad
Historical Kan Periodical , 2009,
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