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Search Results: 1 - 10 of 9023 matches for " Mohamed Bahaa "
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Boundary Control Problem of Infinite Order Distributed Hyperbolic Systems Involving Time Lags  [PDF]
Bahaa Gaber Mohamed
Intelligent Control and Automation (ICA) , 2012, DOI: 10.4236/ica.2012.33024
Abstract: Various optimal boundary control problems for linear infinite order distributed hyperbolic systems involving constant time lags are considered. Constraints on controls are imposed. Necessary and sufficient optimality conditions for the Neumann problem with the quadratic performance functional are derived.
The Propagation of Circularly Polarized Waves in Quantum Plasma  [PDF]
Bahaa F. Mohamed, Rehab Albrulosy
Journal of Modern Physics (JMP) , 2013, DOI: 10.4236/jmp.2013.42033
Abstract:

The quantum effects on the propagation circularly polarized waves have been investigated in electron magnetized quantum plasmas. We obtain the dispersion equations of the propagation of circularly polarized laser beam through cold plasma. The results show that the laser can be propagated due to the quantum effects which enhance the propagation phase velocity. For this purpose, the quantum hydrodynamic (QHD) equations with magnetic field and Maxwell’s equations system is used to derive these dispersion relations. The perturbed electron density and current due to the interaction of laser beam with quantum plasma have been investigated. It is shown that the external magnetic field which is parallel to the propagation waves has strong effect on the dispersion relation for the laser propagation in quantum model than the classical regime.

High-Frequency Electrostatic SW at the Boundary between Quantum Plasma and Metal  [PDF]
Bahaa F. Mohamed, Rehab Albrulosy
Journal of Modern Physics (JMP) , 2013, DOI: 10.4236/jmp.2013.43044
Abstract:

It is shown that high-frequency electrostatic surface waves (SW) could be propagated at right angles to an external magnetic field on the boundary between metal and gaseous plasma due to a finite pressure electron gas in quantum plasma by using the quantum hydrodynamic QHD equations. The dispersion relation for those surface waves in uniform electron plasma is derived under strong external magnetic field. We have shown that the electrostatic surface waves exist also in the frequency for the ranges where electromagnetic SW is impossible. The surface plasma modes are numerically evaluated for the specific case of gold metallic plasma at room temperature. It has been found that dispersion relation of surface modes depends significantly on these quantum effects (Bohm potential and statistical) and should be into account in the case of magnetized or unmagnetized plasma.

The Arab Federation of Libraries and Information (AFLI), and the professional Library Associations on The Internet : An Evaluative Study
Noha Mohamed Bahaa
Cybrarians Journal , 2005,
Abstract: An Evaluative Study for the Arabic web sites of library associations and the Arab Federation of Libraries and Information (AFLI), it begins with general introduction for the associations, then evaluates their web cites according to 7 criterias; objective, Authority, Language, Documentation, Content, Interactive Services, Search Facilities. The study includes the following web sites: Arab Federation of Libraries and Information, Egyptian Library Association, Saudi Library Association, Yemenian Association for Library and Information, Jordanian Library Association, and Bahrainian Library Association.
Surface Waves Excitation in Magnetized Spin Quantum Plasmas  [PDF]
Bahaa F. Mohamed, Salah Y. Elbakry, Abrar A. Salah
Journal of Modern Physics (JMP) , 2016, DOI: 10.4236/jmp.2016.73034
Abstract: The influence of the intrinsic spin of electrons on the excitation of transverse electromagnetic surface waves in magnetized plasma is considered. We use a fluid formalism to include quantum corrections due to the Bohm potential and magnetization energy of electrons due to its spin. The effects of both quantum corrections are shown in the dispersion relation for the propagation of surface waves. Also, it is found that the phase and group velocities are increased due to the quantum effects. In the nonrelativistic motion of electrons, the spin effects become noticeable even when the external magnetic field is relatively low.
Application of Artificial Neural Networks for the Prediction of Water Quality Variables in the Nile Delta  [PDF]
Bahaa Mohamed Khalil, Ayman Georges Awadallah, Hussein Karaman, Ashraf El-Sayed
Journal of Water Resource and Protection (JWARP) , 2012, DOI: 10.4236/jwarp.2012.46044
Abstract: The quality of a water body is usually characterized by sets of physical, chemical, and biological parameters, which are mutually interrelated. Since August 1997, monthly records of 33 parameters, monitored at 102 locations on the Nile Delta drainage system, are stored in a National Database operated by the Drainage Research Institute (DRI). Correlation patterns may be found between water quantity and water quality parameters at the same location, or among water quality parameters within a monitoring location or among locations. Serial correlation is also detected in water quality variables. Through the investigation of the level of information redundancy, assessment and redesign of water quality monitoring network aim to improve the overall network efficiency and cost effectiveness. In this study, the potential of the Artificial Neural Network (ANN) on simulating interrelation between water quality parameters is examined. Several ANN inputs, structures and training possibilities are assessed and the best ANN model and modeling procedure is selected. The prediction capabilities of the ANN are compared with the linear regression models with autocorrelated residuals, usually used for this purpose. It is concluded that the ANN models are more accurate than the linear regression models having the same inputs and output.
Biplanar Open-Wedge High Tibial Osteotomy with Locking Plate for Treatment of Osteoarthritic Varus Knee  [PDF]
Bahaa Kornah, Said K. Abdel-Hameed, Mohamed Abdel-AAl
Open Journal of Orthopedics (OJO) , 2019, DOI: 10.4236/ojo.2019.91001
Abstract: Aim: To introduce and characterize the modified biplanar opening high tibial osteotomy with rigid fixation to treat unicompartmental knee arthritis with varus deformity in active lifestyle patients. Patients and Method: 48 patients (19 females) with monocompartmental gonarthrosis of the knee combined with varus malalignment, 41 with bilateral affection and 7 cases with unilateral gonarthritis (total 89 knees). Mean age: 53 years (range from 42 to 61 years). They were treated and followed from June 2010 to May 2014 (35 months). Biplanar opening high tibial osteotomy technique was used and fixed by low profile locked T-plate (21 cases) and low profile anatomical proximal tibial plate (27cases). Pre-operative mean varus deformity was 16.5° (9° - 19°). We utilized Lysholm score and Knee Society Score for evaluation of preoperative and follow-up data. Results: The average correction angle was 11.50 ± 2.50° (7° - 19°). Preoperative posterior tibial slope was 8.04° ± 1.30° and at last follow-up 9.15° ± 1.60°, respectively (p = 0.437). The joint space distance increased from 4.05 ± 1.30 mm to 4.83 ± 1.33 mm (p < 0.001). The average time to complete bone union was 14.69 ± 1.5 weeks. There were no cases of delayed union or non-union. No major complications like broken plate, nerve injury, or blood vessel injury occurred. No progression of degenerations developed in the three compartments of the knee at final follow-up. The mean score on the Lysholm-Gillquist knee functional scoring scale was 45.5 ± 21.7 preoperatively, and it improved to 77.0 ± 23.9 (p < 0.001). There was no obvious difference in the range of motion before and after operation. The average knee score improved from 51.19 ± 11.82 to 93.49 ± 5.10. Conclusion: Biplanar opening high tibial osteotomy fixed with locking compression plate gives good results for symptomatic unicompartmental gonarthrosis with genu varum. Also this technique can be applied for medial compartment degeneration of the knee without deformity with good functional outcomes.
Comparison between Preoperative and Postoperative Sublingual Misoprostol for Prevention of Postpartum Hemorrhage during Cesarean Section: A Randomized Clinical Trial  [PDF]
Alaa Eldin A. Youssef, Mansour A. Khalifa, Mohamed Bahaa, Ahmed M. Abbas
Open Journal of Obstetrics and Gynecology (OJOG) , 2019, DOI: 10.4236/ojog.2019.94052
Abstract: Background: Blood loss is one of the important complications during cesarean section (CS). Previous reports have shown that misoprostol is effective in reducing blood loss during and after CS. However, the optimum time for its administration to decrease the amount of PPH is still under discussion. Objective: To compare the effect of preoperative and postoperative administration of sublingual misoprostol (400 μg) in reducing the amount of blood loss during and 24 hours after CS. Setting: Obstetrics and Gynecology Department, Faculty of Medicine, Assiut University, Assiut, Egypt, between January 2017 and July 2018. Study Design: A prospective, randomized clinical trial. Methods: Four-hundred thirty women fulfilling the inclusions criteria: elective lower segment CS at term (≥37 weeks) with normal fetal heart tracing who accepted to participate in the study. Patients were divided into two groups; Patients assigned to group 1 received 400 μg sublingual misoprostol immediately after urinary catheterization and before skin incision, while patients assigned to group 2 received sublingual misoprostol immediately after skin closure. The primary outcome was the estimation of intraoperative and postoperative blood loss for 24 hours. Results: There was a significant reduction in the intraoperative blood loss in group 1 compared with group 2 (403.51 ± 72.99 vs. 460.99 ± 74.66 ml, respectively). Also, there was a significant reduction in postoperative blood loss in group 1 compared with group 2 with a statistical significance (169.45 ± 12.03 vs. 195.77 ± 13.34 ml, respectively). Postoperative hemoglobin and
A Security Analysis Framework Powered by an Expert System
Maher Mohamed Gamal, Dr. Bahaa Hasan & Dr. Abdel Fatah Hegazy
International Journal of Computer Science and Security , 2011,
Abstract: Today's IT systems are facing a major challenge in confronting the fast rate ofemerging security threats. Although many security tools are being employedwithin organizations in order to standup to these threats, the information revealedis very inferior in providing a rich understanding to the consequences of thediscovered vulnerabilities. We believe expert systems can play an important rolein capturing any security expertise from various sources in order to provide theinformative deductions we are looking for from the supplied inputs. Throughoutthis research effort, we have built the Open Security Knowledge Engineered(OpenSKE) framework 1, which is a security analysis framework built around anexpert system in order to reason over the security information collected fromexternal sources. Our implementation has been published online in order tofacilitate and encourage online collaboration to increase the practical researchwithin the field of security analysis.
Differences in some constituents, enzymes activity and electrophoretic characterization of different rapeseed (Brassica napus L.) cultivars
Hossam Saad EL-BELTAGI,Amal Amin MOHAMED,Bahaa El-Din Bastawy MEKKI
Analele Universitatii din Oradea, Fascicula Biologie , 2011,
Abstract: Rapeseed is one of the most important oilseed crops cultivated in many parts of the world and used as a source of edible oil for human consumption. The present work reports some phytochemical and nutritional potentials of different rapeseed cultivars with a view to exploit their benefits for human nutrition. Five rapeseed cultivars namely; pactol, silvo, topas, serw 4 and serw 6 were analyzed for their phytochemical constituents (such as glutathione, ascorbate, phenolic, flavonoid contents) and some antioxidant enzymes activity (i.e. GPX; guaiacol peroxidase, APX; ascorbate peroxidase, CAT; catalase, SOD; superoxide dismutase) together with their protein profile. Among all cultivars significant variations in glutathione, ascorbate, phenolic and flavonoid contents were observed. The highest DPPH radical scavenging activity of the extract was observed in topas cultivar. Minor variations were noticed in SDS-PAGE protein profile. The results of the study suggest the phytochemical and nutritional potentials of B. napus seeds for human and other animal uses due to their extensive consumption in the world.
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