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Search Results: 1 - 10 of 544202 matches for " M. N. Shawki "
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Continental Flood Basalts and Rifting: Geochemistry of Cenozoic Yemen Volcanic Province  [PDF]
M. A. Mattash, L. Pinarelli, O. Vaselli, A. Minissale, M. Al-Kadasi, M. N. Shawki, F. Tassi
International Journal of Geosciences (IJG) , 2013, DOI: 10.4236/ijg.2013.410143

Rift formation is a crucial topic in global tectonics. The Yemen rift-related area is one of the most important provinces, being connected to the rifting processes of the Gulf of Aden, the Red Sea and Afar Triangle. In this paper, a review of the Yemen volcanic province and its relations with the Red Sea rifting are presented. Tertiary continental extension in Yemen resulted in the extrusion of large volumes of effusive rocks. This magmatism is divided in the Oligo-Miocene Yemen Trap Series (YTS) separated by an unconformity from the Miocene-Recent Yemen Volcanic Series (YVS). Magmas of the YTS were erupted during the synrift phase and correlate with the first stage of sea-floor spreading of the Red Sea and the Gulf of Aden (30 - 15 Ma), whereas the magmas of the YVS were emplaced during the post rift phase (10 - 0 Ma). A continental within plate character is recognized for both the YTS and YVS basalts. The YTS volcanic rocks are contemporaneous with, and geochemically similar to, the Ethiopian rift volcanism, just as the volcanic fields of the YVS are geochemically alike to most of the Saudi Arabian volcanics. YTS and YVS have analogous SiO2 ranges, but YVS tend to have, on average, higher alkalis and MgO contents than YTS. Fractional crystallization processes dominate geochemical variations of both series. Primitive magmas (MgO

Effects of Aspirin on RheologicalProperties of Erythrocytes In Vitro
Mohamed A. Elblbesy,Abdel Rahman M. Hereba,Mamdouh M. Shawki
International Journal of Biomedical Science , 2012,
Abstract: Aspirin is of proven value as an antithrombotic drug. In unstable angina it reduces the risk of death and myocardial infarction by half. Most studies on the mechanism of action of aspirin have concentrated on the effect of aspirin on platelets.In the present study we have tried to prove that there is another biophysical mechanism of aspirin, and that is through the effect of aspirin on erythrocytes. In this study ten blood samples were incubated with aspirin at different concentrations. The fractal dimension of erythrocytes subjected to shear rates from 5 s-1 to 30 s-1, in a cone and plate device designed and constructed in our lab, was calculated by processing the images of the erythrocyte. At each shear rate, the fractal dimensions of the erythrocytes were found to be strongly correlated with aspirin concentration. It is suggested that further studies using different biophysical methods must be carried out to detect the other mechanisms underlying the effect of aspirin on different blood cells.
Potential role of cadmium in varicocele-associated infertility and its relation to smoking
F Badran, T Hussein, M Shawki, W Abdullah
Alexandria Journal of Medicine , 2010,
Abstract: Objectives: to study the possible role of cadmium in varicocele-associated infertility and its relation to smoking. Patients: the study was performed on twenty infertile men with clinically evident varicocele (grade II & III); half of them were smokers. In addition to another twenty fertile men without clinical varicocele and with normal semen parameters served as a control; half of them were smokers Methods: measuring Cadmium level in the seminal plasma using the atomic absorption spectrophotometer. Results: Statistically significant observed differences in seminal parameters between the studied cases and their control regarding decreased sperm concentration and motility, in addition to increased abnormal sperm morphology among cases (P=0.0001, 0.0001 and 0.02 respectively). A statistically significant high level of cadmium is demonstrated in seminal plasma of non smoking cases as compared with their non smoking control (p<0.0001), and in seminal plasma of smoking control in comparison to non smoking control (p<0.002). Moreover, the level of cadmium detected in seminal plasma of infertile smokers was higher than that of smoking control (P=0.001). Partial correlation between cadmium and seminal parameters of the studied cases and control, in the present study, revealed that cadmium is correlated with sperm concentration and motility even after adjustment for smoking, non smoker/ even smoker, (P=0.009 and 0.003 respectively). Conclusions: the current study supports that environmental exposure to cadmium leads to its accumulation in seminal plasma of patients with varicocele-associated infertility. High level of cadmium is associated with impairment of seminal parameters. In addition, cigarette smoking exacerbates the detrimental effect of varicocele on semen quality and the fertility potential by more accumulation of cadmium in seminal plasma. Key Words: cadmium; varicocele, infertility; smoking
Vehicle gearbox fault diagnosis using noise measurements
Sameh M. Metwalley, Nabil Hammad, Shawki A. Abouel-Seoud
International Journal of Energy and Environment , 2011,
Abstract: Noise measurement is one of many technologies for health monitoring and diagnosis of rotating machines such as gearboxes. Although significant research has been undertaken in understanding the potential of noise measurement in monitoring gearboxes this has been solely applied on any types of gears (spur, helical, ..etc.). The condition monitoring of a lab-scale, single stage, gearbox, represents the vehicle real gearbox, using non-destructive inspection methodology and the processing of the acquired waveform with advanced signal processing techniques is the aim of the present work. Acoustic emission was utilized for this purpose. The experimental setup and the instrumentation are present in detail. Emphasis is given on the signal processing of the acquired noise measurement signal in order to extract conventional as well as novel parameters potential diagnostic value from the monitoring waveform. The evolution of selected parameters/features versus test time is provided, evaluated and the parameters with most interesting diagnostic behavior are highlighted. The present work also reports the results concluded by long term (~ 6.0 h) experiments to a defected gear system, with a transverse cuts ranged from 0.75 mm to 3.0 mm to simulate the tooth crack. Different parameters, related by the analysis of the recording signals coming from acoustic emission are presented and their diagnostic value is discussed for the development of a condition monitoring system.
Global Norms, Local Implementation — How Are Global Norms Translated Into Local Practice?
Noha Shawki
Globality Studies Journal : Global History, Society, Civilization , 2011,
Abstract: The literature on the emergence, diffusion, and implementation of human rights norms has highlighted the role of a variety of actors as norm entrepreneurs who introduce and promote new international norms and lobby governments to adopt them. Even though this literature recognizes a diversity of actors as norm transmitters, only national governments are considered as actors in the norm implementation process, and we know relatively little about how sub-national public actors and non-state actors can diffuse and implement norms locally. How can we understand, for example, how cities such as Eugene, Oregon, promote human rights standards locally and mainstream them into their operations? The article begins to develop a framework that can help us address this question and understand the role of sub-national and non-state actors in the process of norm diffusion and implementation and in translating global norms into local practices.
Noise evaluation of automotive A/C compressor
Sameh M. Metwally, Mohamed I. Khalil, Shawki A. Abouel-seoud
International Journal of Energy and Environment , 2011,
Abstract: Passenger compartment's interior noise and thermal performance are essential criteria for the driving comfort of vehicles. The air-conditioning system influences both field of comfort. It creates comfortable thermal conditions. On the other hand, the noise radiation of the air-condition system's components can be annoying. The blower, the air distribution ducts and the registers affect air rush noise. In some cases, the refrigerant flow creates hissing noise. Such noise has a great influence on vehicle acoustical comfort and on overall quality perception of a vehicle Therefore, the acoustic performance of air-condition compressors become more important for passenger comfort. At engine idling and at extreme temperatures the air-condition compressor can be audible as the significant sound source. However, the aim of this paper is to quantify air-borne noise characteristics of vehicle air-condition compressor. A simulated experimental model comprises a small wooden box with dimensions of 0.5 x 0.5 x 0.5 m represented the principle of hemi-anechoic room was designed and acoustic characteristics of the sound field inside the box were determined. The air-condition compressor characteristics parameters considered in this paper are fan position and electric motor speed. In addition, a single number of the air column natural frequency is calculated. The results indicate that significant information can be obtained in order to investigate the vehicle air-condition compressor and consequently improve the vehicle interior quietness.
Comparative Study on the Efficiency of Using Pulsed and Direct Current Electrochemotherapy in Treating Ehrlich Tumor
Mamdouh M. Shawki,Mohammed A. Elblbesy,Thanaa E. Shalaby,Metwali A. Qotb
International Journal of Biomedical Science , 2012,
Abstract: The Electrochemotherapy (ECT) is an effective treatment of cutaneous and subcutaneous solid tumors. Electric field is applied to tumor nodules to enhance the delivery/distribution of a non-permeable or poorly permeable chemotherapeutic agent into the tumor cells thereby increasing local concentration of anticancer drugs. The aim of this study was to evaluate the effectiveness of using two types of electric fields in ECT, pulsed sine waves and direct current (DC) application in addition to intra-tumoral injection of bleomycin (BLM), a cytotoxic drug for treating Ehrlich tumor. The electric fields were delivered through six stainless steel needle electrodes inserted into the tumor. Tumor volume, tumor mass, percentage of fragmented DNA in the tumor tissue, relative spleen mass/total body mass, mortality rate, histological and ultrastructural examinations were investigated in each group. There were 40% complete response (CR) and 60% partial response (PR) in the group treated with DC as the electric field source of ECT, while 0% (CR) and only 25% (PR) were found in the group treated with pulsed sine wave ECT. We concluded that the utilization of low dose DC for ECT gives better results than the low voltage pulsed sine waves in treating Ehrlich tumor which may be due to the dual effects of electrochemical reactions evoked by DC application and the anti-cancer activity ofBLM.
Carrier Frequency Offsets Problem in DCT-SC-FDMA System: Investigation and Compensation
Faisal S. Al-kamali,Moawad I. Dessouky,Bassiouny M. Sallam,Farid Shawki
ISRN Communications and Networking , 2011, DOI: 10.5402/2011/842093
Tabu Search: A Meta Heuristic for Netlist Partitioning
Shawki Areibi,Anthony Vannelli
VLSI Design , 2000, DOI: 10.1155/2000/62159
Abstract: The main goal of the paper is to explore the effectiveness of a new method called Tabu Search [1] on partitioning and compare it with two techniques widely used in CAD tools for circuit partitioning i.e., Sanchis Interchange method and Simulated Annealing, in terms of the running time and quality of solution. The proposed method integrates the well known iterative multi-way interchange method with Tabu Search and leads to a very powerful network partitioning heuristic. It is characterized by an ability to escape local optima which usually cause simple descent algorithms to terminate by using a short term memory of recent solutions. Moreover, Tabu Search permits backtracking to previous solutions, which explore different directions and generates better partitions.
Architecture Exploration Based on GA-PSO Optimization, ANN Modeling, and Static Scheduling
Ahmed Elhossini,Shawki Areibi,Robert Dony
VLSI Design , 2013, DOI: 10.1155/2013/624369
Abstract: Embedded systems are widely used today in different digital signal processing (DSP) applications that usually require high computation power and tight constraints. The design space to be explored depends on the application domain and the target platform. A tool that helps explore different architectures is required to design such an efficient system. This paper proposes an architecture exploration framework for DSP applications based on Particle Swarm Optimization (PSO) and genetic algorithms (GA) techniques that can handle multiobjective optimization problems with several hybrid forms. A novel approach for performance evaluation of embedded systems is also presented. Several cycle-accurate simulations are performed for commercial embedded processors. These simulation results are used to build an artificial neural network (ANN) model that can predict performance/power of newly generated architectures with an accuracy of 90% compared to cycle-accurate simulations with a very significant time saving. These models are combined with an analytical model and static scheduler to further increase the accuracy of the estimation process. The functionality of the framework is verified based on benchmarks provided by our industrial partner ON Semiconductor to illustrate the ability of the framework to investigate the design space. 1. Introduction Over the past few decades, the demand for embedded digital signal processing (DSP) systems has been increasing constantly. These systems are used in numerous applications such as portable audio players, wireless communication sets, and intelligent hearing aid devices, just to name a few. Due to the nature of these devices, they are usually implemented using System on Chip (SoC) technology. DSP applications are complex, parallel in nature, and time consuming to develop. Designers are usually faced with different conflicting design objectives, such as low power, low cost, flexibility, and high performance. SoC embedded systems are usually equipped with a heterogeneous multiprocessor architecture in which different components are integrated on a single chip. These components range from fully programmable processors to dedicated hardware blocks. The designer has to select the proper components to optimize the different design objectives. Fully programmable processors could be selected for flexibility in supporting multiple applications and system extension while dedicated hardware accelerators are used to optimize hard constraints such as time and power dissipation. Several architectures are available to implement a given DSP
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