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Experimental investigation on shear strength of elastic end-web panels strengthened with CFRP strips
S. S. Safar and Mohamed N. Abou-Zeid
An experimental program was conducted to investigate the shear strength of elastic end-web panels of steel plate girders strengthened with intermediate-modulus carbon fiber-reinforced polymers, CFRP, strips. Test parameters included; number of strips, aspect ratio of end-web panel and width-to-thickness ratio of web plate. Twelve plate girder specimens composed of mild-steel were loaded in a four-point bending test till failure. The girders were proportioned so that the load capacity was governed by elastic web buckling. Four specimens were not strengthened to serve as reference girders whereas the remaining specimens were strengthened by applying CFRP strips in the diagonal tension direction on one or both sides of the web. Test results indicated that the buckling strength of strengthened specimens was not improved, however, the ultimate shear strength increased by 6% to up to 120% due to significant increase in post-buckling strength. The increment in post-buckling strength due to pasting CFRP strips on web plate was several multiples of that of reference girders and was reduced when slender web plates or long end-web panels were utilized. In addition to higher ultimate shear capacity, it was observed that vertical deflections, out-of-plane displacements of the web and bending curvature of transverse stiffeners of strengthened girders were reduced at ultimate load. It was concluded that the ultimate shear strength of elastic end-web panels was successfully improved using intermediate-modulus CFRP strips. On the other hand, current design rules adopted by current AISC specifications need to be revised to account for post-buckling strength of elastic end-web panels.
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Hierarchical prior zero-forcing for cognitive relaying
Feeby Salib and Karim G. Seddik
In this paper, cognitive radio relaying in the physical layer is investigated where the cognitive base station (CBS) relays the PU's signal while transmitting its own signals to its secondary users (SUs). A new and simple linear method for beamforming, based on zero-forcing beamforming, adapted for the different levels of priority that users may possess in a cognitive radio network, is proposed and the special case of two SUs is analytically studied. © 2014 IEEE.
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On the stability of random multiple access with feedback exploitation and queue priority
Karim G. Seddik
In this paper, we study the stability of two interacting queues under random multiple access in which the queues leverage the feedback information. We derive the stability region under random multiple access where one of the two queues exploits the feedback information and backs off under negative acknowledgement (NACK) and the other, higher priority, queue will access the channel with probability one. We characterize the stability region of this feedback-based random access protocol and prove that this derived stability region encloses the stability region of the conventional random access (RA) scheme that does not exploit the feedback information. © 2014 IEEE.
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A POMDP framework for cognitive MAC based on primary feedback exploitation
Karim G. Seddik and Amr A. El-Sherif
[abstract not available]
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On the occurrence of ponzi schemes in presence of credit restrictions penalizing default
A. Seghir
[no abstract provided]
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Investigation of a novel discrete slot film cooling scheme
Karim M. Shalash, Lamyaa A. El-Gabry, and Mohamed M.Abo El-Azm
[abstract not available]
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Affordances of computer-supported collaborative learning platforms: A systematic review
Doaa Shawky, Ashraf Badawi, Tamer Said, and Russanne Hozayin
[abstract not available]
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Cairo diary: Space-wars, public visibility and the transformation of public space in post-revolutionary Egypt
Mona Abaza
[no abstract provided]
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Cyberspace and the changing face of protest and public culture in Egypt
Mona Abaza
[no abstract provided]
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Optimum solar-powered HDH desalination system for semi-isolated communities
Khalid M. Abd El-Aziz, Hamza Karim Hamza, Mohamed El Morsi, Ashraf O. Nassef, and Sayed M. Metwalli
[abstract not available]
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Unattended vehicle detection for automatic traffic light control
Aya Salama Abdel Hady and Mohamed Moustafa
[abstract not available]
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Efficient sensitivity analysis of waveguide structures using Finite Element Method (FEM)
Mohamed R. Abdelhafez, Mohamed H. Bakr, and Mohamed A. Swillam
[abstract not available]
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A fuzzy risk management framework for the egyptian real estate development projects
Ahmed M. Aboshady, Mohamed M.G. Elbarkouky, and Mohamed M. Marzouk
[abstract not available]
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Fuzzy consensus qualitative risk analysis framework for building construction projects
Ahmed M. Aboushady, Mohamed M. Marzouk, and Mohamed M.G. Elbarkouky
[abstract not available]
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Variability mitigation using correction function technique
Shady Agwa, Eslam Yahya, and Yehea Ismail
[abstract not available]
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Social pervasive systems: The integration of social networks and pervasive systems
Soumaia Al Ayyat, Sherif G. Aly, and Khaled A. Harras
[abstract not available]
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Interest aware PeopleRank: Towards effective social-based opportunistic advertising
Soumaia Al Ayyat, Khaled A. Harras, and Sherif G. Aly
[abstract not available]
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Network fabric fault-tolerance for Ethernet-based Networked Control Systems
Christine H. Alfi, Yara K. Hilal, Gina H. Aziz, Hassan H. Halawa, and Ramez M. Daoud
Networked Control Systems (NCS) are widely used in industrial applications. Ethernet has recently been used as the communication protocol in NCS. Since overcoming faults is crucial in control systems, fault-tolerance in NCS is being extensively investigated. This paper focuses on the fault-tolerance aspect of Ethernet-based NCS at the network fabric level. It proposes a novel architecture that achieves successful recovery from any single link or switch failure. The model was also tested and proved to be fault-tolerant for some multiple failures. © 2013 IEEE.
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Selection of precision machining cutting parameters via a modified Efficient Global Optimization approach
Mohamed Aly, Karim Hamza, Mohammed Shalaby, and Ashraf O. Nassef
[abstract not available]
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Counseling and psychotherapy in egypt: Ambiguous identity of a regional leader
Mona M. Amer
[no abstract provided]
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Migration, inflation and social mobility: A sociological interpretation of Egypt's current economic and political crisis
Galal Ahmad Amin
[no abstract provided]
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Gender, Poverty and Agro-Biodiversity Conservationin Rural Egypt and Tunisia
Habib Ayeb and Reem Saad
This paper investigates the links between poverty, gender, and biodiversity in rural Egypt and Tunisia. Its aim is to highlight the significant role of women in biodiversity conservation, as well as the complexities that characterize the relationship between poverty and biodiversity protection. Despite natural and social diversity, Egypt and Tunisia are comparable in terms of their present paths of economic transformation. Agriculture and rural society are comparable in both countries in terms of scarcity ofland and water, and threats to agricultural resources (urbanization, industrialization, tourism, agro-investment, etc.). In both countries, rural dwellers are increasingly resorting to non-agricultural activity, including internal and external labor migration. In both countries, the liberalization of agricultural land and water markets has been a core component of economic reform and structural adjustment policies. Those reforms have aggravated the problem of rural poverty, and have had adverse effects on the general welfare and status of food security of a significant number of rural households. In both countries, the over-exploitation of agricultural resources and the introduction of new modes of farming (including the increasing reliance on hybrid seeds) are posing significant threats to agricultural biodiversity and to the ecological balance in general. This problem has important implications for the welfare of rural dwellers, especially because of the implications for food security. This paper seeks to test a hypothesis supported by research evidence from other world regions: that women's increased access to secure land tenure and other agricultural resources is positively correlated with biodiversity conservation. The paper will also test the same correlation with respect to poor farmers. The paper is primarily based on fieldwork carried out in two comparable regions of rural Egypt and Tunisia, namely the region ofFayoum and the Oasis of Gabes respectively. In both areas there are serious challenges to agro-biodiversity and the ecological balance in general. These include the encroachment of urbanization and industrialization, emerging modes ofland exploitation that over-exploit natural resources, and the widespread use of hybrid seed varieties to the detriment oflocal varieties. In the area under study in rural Egypt, the main challenge to agro-biodiversity is the spread of hybrid seeds, while in the Tunisian case it is the encroaching urbanization and industrialization, and an expansion of investment agriculture. The paper is divided into three main sections. The first outlines the main conceptual issues, including comparative material from agrarian societies outside of the MENA region. The second details the Egypt case, and the third the Tunisian case.
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