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Search Results: 1 - 10 of 199255 matches for " Sarwat N. Hanna "
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Numerical Solution of the Rotating Shallow Water Flows with Topography Using the Fractional Steps Method  [PDF]
Hossam S. Hassan, Khaled T. Ramadan, Sarwat N. Hanna
Applied Mathematics (AM) , 2010, DOI: 10.4236/am.2010.12014
Abstract: The two-dimensional nonlinear shallow water equations in the presence of Coriolis force and bottom topography are solved numerically using the fractional steps method. The fractional steps method consists of splitting the multi-dimensional matrix inversion problem into an equivalent one dimensional problem which is successively integrated in every direction along the characteristics using the Riemann invariant associated with the cubic spline interpolation. The height and the velocity field of the shallow water equations over irregular bottom are discretized on a fixed Eulerian grid and time-stepped using the fractional steps method. Effects of the Coriolis force and the bottom topography for particular initial flows on the velocity components and the free surface elevation have been studied and the results are plotted.
Modeling of Tsunami Generation and Propagation by a Spreading Curvilinear Seismic Faulting in Linearized Shallow-Water Wave Theory  [PDF]
Hossam S. Hassan, Khaled T. Ramadan, Sarwat N. Hanna
Applied Mathematics (AM) , 2010, DOI: 10.4236/am.2010.11007
Abstract: The processes of tsunami evolution during its generation in search for possible amplification mechanisms resulting from unilateral spreading of the sea floor uplift is investigated. We study the nature of the tsunami build up and propagation during and after realistic curvilinear source models represented by a slowly uplift faulting and a spreading slip-fault model. The models are used to study the tsunami amplitude amplification as a function of the spreading velocity and rise time. Tsunami waveforms within the frame of the linearized shallow water theory for constant water depth are analyzed analytically by transform methods (Laplace in time and Fourier in space) for the movable source models. We analyzed the normalized peak amplitude as a function of the propagated uplift length, width and the average depth of the ocean along the propagation path.
Generation and Propagation of Tsunami by a Moving Realistic Curvilinear Slide Shape with Variable Velocities in Linearized Shallow-Water Wave Theory  [PDF]
Hossam Shawky Hassan, Khaled Tawfik Ramadan, Sarwat Nageeb Hanna
Engineering (ENG) , 2010, DOI: 10.4236/eng.2010.27070
Abstract: The process of tsunami evolution during its generation under the effect of the variable velocities of realistic submarine landslides based on a two-dimensional curvilinear slide model is investigated. Tsunami generation from submarine gravity mass flows is described in three stages. The first stage represented by a rapid curvilinear down and uplift faulting with rise time. The second stage represented by a unilaterally propagation in the positive x direction to a significant length to produce curvilinear two-dimensional models represented by a depression slump, and a displaced accumulation slide model. The last stage represented by the time variation in the velocity of the accumulation slide (block slide). By using transforms method, Laplace in time and Fourier in space, tsunami waveforms within the frame of the linearized shallow water theory for constant water depth are analyzed analytically for the movable source model. Effect of the water depths on the amplification factor of the tsunami generation by the submarine slump and slide for different propagation lengths and widths has been studied and the results are plotted. Comparison of tsunami peak amplitudes is discussed for different propagation lengths, widths and water depths. In addition, we demonstrated the tsunami propagation waveforms after the slide stops moving at different propagation times.
Central Retinal Vein Occlusion with Therapeutic Level of Anticoagulation
Sarwat Salim,Wai-Ching Lam,Wahid Hanna
Case Reports in Medicine , 2009, DOI: 10.1155/2009/827982
Abstract: Purpose. To describe a patient with two episodes of deep venous thrombosis and factor V Leiden mutation who presented with central retinal vein occlusion (CRVO) despite prophylactic use of warfarin sodium (Coumadin). Methods. A case report of a 44-year-old woman with a history of recurrent deep venous thrombosis and Factor V Leiden mutation was placed on lifelong prophylactic therapy with warfarin. The patient presented with CRVO in the left eye despite therapeutic levels of warfarin. Results. Extensive systemic evaluation disclosed high titers for antinuclear antibody (ANA). Conclusion. Systemic anticoagulation with warfarin may not preclude further thrombotic episodes. In younger patients presenting with retinal vein occlusion and pre-existing multiple thrombophilic risk factors, a multidisciplinary approach is recommended to explore other therapeutic options to avoid further thromboembolic complications.
SAT: Does Racial Bias Exist?  [PDF]
Sarwat Amin Rattani
Creative Education (CE) , 2016, DOI: 10.4236/ce.2016.715213
Abstract: SAT is one of the most widely used tests today. But much controversy surrounds it and many times the biases existing in the test have been questioned. The purpose of this paper is to explore whether these accusations against SAT hold any merit and racial bias actually exists in the test. If it does, are there any methods that can be employed to improve these tests. Analysis of different research papers and articles reveals that although the score gap in ethnic groups can be accounted to socioeconomic status and stereotype threat, considerable racial bias also exists in the test which cannot be dismissed. Improvements in SAT need to be made on immediate basis, because millions of applicants reside on this test in the future. Not dealing with this problem on immediate basis also compromises the ethical and moral standards of the society.
Growth Response of Buffel Grass (Cenchrus ciliaris) to Phosphorus and Mycorrhizal Inoculation
Irshad Ahmad Khan,Shahbaz Ahmad,Sarwat N. Mirza,Moazzam Nizami
Agriculturae Conspectus Scientificus (ACS) , 2007,
Abstract: Arbuscular-mycorrhizal symbiosis confers numerous benefits to host plants including improved tolerance to abiotic and biotic stresses. Although the majority of grasses form an arbuscular mycorrhizal symbiosis, little is known of the mycorrhization of Buffel grass (Cenchrus ciliaris). A pot study was conducted in sterilized soil to determine the effect of mycorrhizal inoculation and phosphorus amendment on the biomass production in C. ciliaris. Mycorrhizal fungi used were Gigaspora rosea, Glomus intraradices and Glomus etunicatum. Inoculation with Gigaspora rosea alone, and combined incoculation with Glomus intraradices + Gigaspora rosea and Glomus intraradices + Glomus etunicatum signifi cantly (P<0.05) increased dry biomass in unamended and 25 kg P2O5 ha-1 treatments. Combined inoculation with Glomus intraradices + Gigaspora rosea and Glomus intraradices + Glomus etunicatum showed pronounced (P<0.05) eff ect on dry biomass compared to inoculation with Gigaspora rosea alone in unamended and 25 kg P2O5 ha-1 treatments. Combined inoculation with Glomus intraradices + Glomus etunicatum resulted in signifi cantly (P<0.05) higher dry biomass campared to the combined inoculation with Glomus intraradices + Gigaspora rosea and inoculation with Gigaspora rosea alone in unamended and 25 kg P2O5 ha-1 treatments. Th e results clearly show that inoculation of C. ciliaris plants with mycorrhizal fungi Gigaspora rosea, Glomus intraradices and Glomus etunicatum is highly benefi cial for the growth and biomass production in the absence or presence of P2O5 under sterile soil conditions. Inoculation of C. ciliaris plants with these mycorrizal fungi may help in forage production in marginal and shallow soils of the rangelands of Pakistan.
Stability Conditions of Kirchhoff's law Circuit
Nagham N. Hanna
International Journal of Electronics and Computer Science Engineering , 2013,
Abstract: The conditions of stability have been studied by criteria depended on polynomial of degree four got from a system of Differential Equations of Kirchhoff's law, this exactly which the paper discussed and the Kirchhoff's system has form: Where { }q is the charge on the capacitor, [ ] L is the inductance and cS1= , where c is the capacitor.Which represent the voltage drop across the capacitor and inductance.
The Role of Anterior Segment Optical Coherence Tomography in Glaucoma
Sarwat Salim
Journal of Ophthalmology , 2012, DOI: 10.1155/2012/476801
Abstract: The anterior segment optical coherence tomography provides an objective method to assess the anterior segment of the eye, including the anatomy of the anterior chamber angle. This technology allows both qualitative and quantitative analyses of the angle and has shown potential in detecting and managing angle-closure glaucoma. In addition, it has a role in identifying pathology in some forms of secondary open-angle glaucoma and postsurgical management of glaucoma. Limitations of this technology include its cost and inability to visualize well structures posterior to the iris, such as the ciliary body. This paper focuses on potential benefits and limitations of anterior segment optical coherence tomography when compared with conventional gonioscopy and ultrasound biomicroscopy. Various clinical entities will be described to discuss its potential role in glaucoma practice.
Factors Influencing Successful Brand Extension into Related and Unrelated Product Categories
Sarwat Afzal
Asian Economic and Financial Review , 2013,
Abstract: This study describes the study that analyzes the factors influencing successful brand extension. Specifically the study analyze the impact of similarity, brand reputation, perceived risk and consumer innovativeness on the success of brand extension into related or unrelated categories of FMCG products. A set of hypotheses were developed and tested by regression analysis. It investigated the effect of factors such as brand reputation, perceived risk, perceived similarity and consumer innovativeness on successful brand extension in FMCG. This study provides support for two out of the four hypotheses of Hem & Charnatony's model. Parent brand reputations, and consumer innovativeness, have powerful positive effect on consumers' mind-set towards the brand extension in related and unrelated product category. The third hypothesis i.e. interaction of perceived similarity is positive and significant in related FMCG product category and hence hypothesis 1 is partially supported. However the fourth hypothesis i.e. perceived risk in preparing the extension with customers' attitude regarding brand extension could not be supported. The result of this study suggests a number of implications for product extensions in our country. Implications have been discussed for the organization of consumer information and effect across related and unrelated product class and for understanding earlier research results on brand extension.
The Role of Anterior Segment Optical Coherence Tomography in Glaucoma
Sarwat Salim
Journal of Ophthalmology , 2012, DOI: 10.1155/2012/476801
Abstract: The anterior segment optical coherence tomography provides an objective method to assess the anterior segment of the eye, including the anatomy of the anterior chamber angle. This technology allows both qualitative and quantitative analyses of the angle and has shown potential in detecting and managing angle-closure glaucoma. In addition, it has a role in identifying pathology in some forms of secondary open-angle glaucoma and postsurgical management of glaucoma. Limitations of this technology include its cost and inability to visualize well structures posterior to the iris, such as the ciliary body. This paper focuses on potential benefits and limitations of anterior segment optical coherence tomography when compared with conventional gonioscopy and ultrasound biomicroscopy. Various clinical entities will be described to discuss its potential role in glaucoma practice. 1. Introduction Glaucoma is a progressive optic neuropathy characterized by structural changes in the optic nerve head with corresponding changes in the visual field. While the final pathway involving structural and functional loss is similar for various types of glaucoma, a comprehensive evaluation of the drainage angle is critical for accurate diagnosis and appropriate therapeutic intervention. In the United States, the most common type of glaucoma is primary open-angle glaucoma, whereas primary angle-closure glaucoma is the major form in other parts of the world [1–4]. There is a wide spectrum of anatomical variation in the drainage angle in normal and affected eyes. Many patients may present with narrow or occludable angles without any other abnormality; some may have primary angle closure with peripheral anterior synechiae and/or elevated intraocular pressure; yet others may have primary angle-closure glaucoma with optic nerve damage. Furthermore, forces at different anatomic levels in the eye may be responsible for the pathogenesis of angle closure: the iris (pupillary block), the ciliary body (plateau iris), the lens (phacomorphic glaucoma), and posterior to the lens (malignant glaucoma) [5]. Therefore, assessing anterior chamber angle anatomy and surrounding structures with anterior segment imaging is of tremendous importance for identifying individuals in the early stages of the disease and guiding therapeutic decisions. 2. Discussion 2.1. Gonioscopy Gonioscopy remains the reference standard for assessing anterior chamber angle in the eye. It is inexpensive, rapidly performed at the slit-lamp, permits dynamic visualization of the entire angle quadrant, and allows indentation
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