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Finite element modeling assumptions impact on seismic response demands of MRF-buildings

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Earthquake Engineering and Engineering Vibration 2018年第4期17卷 821-834页

作者： Shehata E abdel raheem Ahmed K abdel Zaher Ahmed MA Taha Civil Engineering Department Engineering College Taibah University Civil Engineering Department Faculty of Engineering Assiut University

Recent seismic events have raised concerns over the safety and vulnerability of reinforced concrete moment resisting frame ＂RC-MRF＂ buildings. The seismic response of such buildings is greatly dependent on the computational tools used and the inherent assumptions in the modelling process. Thus, it is essential to investigate the sensitivity of the response demands to the corresponding modelling assumption. Many parameters and assumptions are justified to generate effective structural finite element（FE） models of buildings to simulate lateral behaviour and evaluate seismic design demands. As such, the present study focuses on the development of reliable FE models with various levels of refinement. The effects of the FE modelling assumptions on the seismic response demands on the design of buildings are investigated. the predictive ability of a FE model is tied to the accuracy of numerical analysis; a numerical analysis is performed for a series of symmetric buildings in active seismic zones. The results of the seismic response demands are presented in a comparative format to confirm drift and strength limits requirements. A proposed model is formulated based on a simplified modeling approach, where the most refined model is used to calibrate the simplified model.

关键词： RC-MRF buildings design codes provisions seismic design finite element modeling modeling assumptions response demands

Ground motion spatial variability effects on seismic response control of cable-stayed bridges

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Earthquake Engineering and Engineering Vibration 2011年第1期10卷 37-49页

作者： Shehata E. abdel raheem Toshiro Hayashikawa Uwe Dorka Civil Engineering Department Faculty of Engineering Assiut University Bridge and Structural Design Engineering Hokkaido University Steel & Composite Structures Kassel Universitt

The spatial variability of input ground motion at supporting foundations plays a key role in the structural response of cable-stayed bridges （CSBs）; therefore, spatial variation effects should be included in the analysis and design of effective vibration control systems. The control of CSBs represents a challenging and unique problem, with many complexities in modeling, control design and implementation, since the control system should be designed not only to mitigate the dynamic component of the structural response but also to counteract the effects of the pseudo-static component of the response. The spatial variability effects on the feasibility and efficiency of seismic control systems for the vibration control of CSBs are investigated in this paper. The assumption of uniform earthquake motion along the entire bridge may result in quantitative and qualitative differences in seismic response as compared with those produced by uniform motion at all supports. A systematic comparison of passive and active system performance in reducing the structural responses is performed, focusing on the effect of the spatially varying earthquake ground motion on the seismic response of a benchmark CSB model with different control strategies, and demonstrates the importance of accounting for the spatial variability of excitations.

关键词： cable-stayed bridge vibration control earthquake spatial variation seismic design semi-active control

Effect of Heat Input on the Microstructure and Properties of Dissimilar Weld Joint Between Incoloy 28 and Superaustenitic Stainless Steel

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Acta Metallurgica Sinica(English Letters) 2014年第2期27卷 259-266页

作者： M.S.abdel Rahman N.A.abdel raheem M.R.El Koussy Department of Metallurgy Faculty of EngineeringCairo University

Abstract This work focuses on studying the effect of welding heat input within the range from 1 to 5 kJ/mm on the microstructure and the corresponding mechanical and corrosion properties of dissimilar joint between superaustenitic stainless steel （UNS S31254） and Incoloy 28 （UNS N08028）. The two materials were butt-welded with ER NiCrMo3. The metallurgical changes associated with welding of SASS and Incoloy 28 were studied using optical microscope, SEM, and EDX. The mechanical and corrosion properties were investigated using tensile test, Vickers hardness test, and pitting and crevice corrosion tests. The weld metal microstructure showed precipitates with needle-like shape at 3 and 5 kJ/mm. Also, the microstructure showed unmixed zone （UMZ） at the fusion line of both SASS and Incoloy 28 sides at all the investigated heat inputs. The Mo microsegregation within UMZ at Incoloy 28 side increased as the heat input increased from 1 to 5 k J/ram but that in SASS increased with increasing heat input from 1 to 3 kJ/mm and then decreased with increasing from 3 to 5 kJ/mm. The ultimate tensile strengths for all specimens at all the investigated heat inputs are acceptable. The average hardness noticeably changed in weld metal as the heat input increased from 1 to 5 kJ/mm. Other zones such as HAZ or UMZ did not demonstrate marked changes in the average hardness. The pitting and crevice corrosion rates of the weld joint were found significant at l and 3 kJ/mm but insignificant at 5 kJ/mm according to ASTM G48.

关键词： Superaustenitic Incoloy 28 Welding Heat input Unmixed zone Microsegregation Corrosion

An update on penile reconstruction

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Asian Journal of Andrology 2011年第3期13卷 391-394,511页

作者： Giulio Garaffa Amr abdel raheem David John Ralph St Peter＇s Andrology and the Institute Of Urology wig 6BJ London UK

Penile reconstruction still represents a formidable challenge for the urologist. In this review, the most recent advances in penile reconstruction after trauma, excision of benign and malignant disease and in patients... 详细信息

关键词： aphallia female-to-male sex reassignment surgery genital lymphoedema lichen sclerosus micropenis penile cancer penile trauma

Pharmacological effects of ethanol extract of Egyptian Artemisia herba-alba in rats and mice

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Asian Pacific Journal of Tropical Biomedicine 2016年第1期6卷 44-49页

作者： Gehad abdel raheem abdel Jaleel Heba Mohammed Ibrahim Abdallah Nawal E.L.Sayed Gomaa Pharmacology Department National Research Centre

Objective:To investigate some pharmacological effects including gastroprotective,antiinflammatory,analgesic,antipyretic and in vitro antioxidant effects of Artemisia herbaalba extract in different experimental ***:Inflammation was induced in rat paw by subcutaneous injection of 1%(v/v)carrageenan *** was induced in mice by intraperitoneal injection of 0.6%(v/v) acetic acid *** was induced using Brewer's yeast *** lesion was induced in rats by oral administration of 99% *** anti-inflammatory,analgesic,antipyretic and gastroprotective activities of Artemisia herba-alba extract were investigated *** vitro antioxidant effect was investigated using DPPH free ***:The plant extract showed anti-inflammatory effect in carrageenan-induced paw edema in rats,analgesic effect against acetic acid-induced writhing,and antipyretic activity in Brewer's yeast model of ***,it was shown to be a gastroprotective agent against ethanol-induced gastric *** plant also exhibited a free radical scavenging potential in an in vitro antioxidant study using ***:The results validate the use of the investigated plant in traditional medicine for different ailments.

关键词： Artemisia herba-alba Gastric ulcer Inflammation Antioxidant Rats Mice

The Role of CK20, p53 and p63 in Differentiation of Some Urothelial Lesions of Urinary Bladder, Immunohistochemical Study

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Open Journal of Pathology 2014年第4期4卷 181-193页

作者： Sayed abdel raheem abdel Naby Saied Rabee Al Shaer Osama Mustafa ali Hassan ali Departments of Pathology and Anatomy Faculty of Medicine Al Azhar University Cairo Egypt

Background: Differentiation of urothelial hyperplasia, dysplasia and carcinoma in situ (CIS) may pose diagnostic difficulties. We aim to evaluate the role of CK20, p53 and p63 in differentiation of such lesions. Methods: we evaluate these markers in 213 cases of bladder lesions (14 hyperplasia, 7 dysplasia, 5 CIS, 25 noninvasive and 162 invasive urothelial carcinoma) in a retrospective study on sections from formalin-fixed, paraffin-embedded blocks. Cytoplasmic staining considered for CK20 and nuclear staining for p53 and p63. Results: CK20 was expressed in 14 out of 14 hyperplasia (4 strong, 7 moderate, 3 weak), in 7 out of 7 dysplasia (4 strong , 3 moderate), in 5 out of 5 CIS, in 19 out of 25 noninvasive carcinoma;strong in 11 (7 low grade, 4 high grade), moderate in 7 (5 low grade, 2 high grade), and weak in 1 case of low grade, in 136 out of 162 invasive carcinoma;strong in 46 (22 grade II, 24 grade III), moderate in 71 (2 grade I, 58 grade II, 11 grade III), and weak in 19 (2 grade I, 15 grade II, 2 grade III), no expression in 2 cases of grade IV. p53 was expressed in 7 out of 14 hyperplasia (weak in all cases), in 7 out of 7 dysplasia (5 strong, 2 moderate), in 5 out of 5 CIS (strong in all cases), in 20 out of 25 noninvasive carcinoma (8 strong, 9 moderate, 3 weak), in 135 out of 162 invasive carcinoma (34 strong, 73 moderate, 28 weak). p63 was expressed in 14 out of 14 hyperplasia, in 7 out of 7 dysplasia, in 4 out of 5 CIS, in 25 out of 25 noninvasive carcinoma, and in 134 out of 162 invasive carcinoma (28 strong, 63 moderate, 43 weak). CK20 was insignificant in noninvasive and significant in invasive carcinoma, while p53 and p63 were significant in noninvasive and invasive carcinoma. Conclusion: CK20, p53 and p63 are useful in differentiation of different bladder lesions.

关键词： Urothelial Lesions CK20 p53 p63

Impact of COVID-19 on endourology surgical practice in Saudi Arabia:A national multicenter study

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Asian Journal of Urology 2021年第4期8卷 416-423页

作者： abdel raheem ali Yahya Ghazwani Ibrahim Alowidah Raed A.Azhar Mohammed Alomar Ahmed Alzahrani Ossamah Alsowayan Wissam Kamal Abdulrahman Alalayet Ahmad Bugis Abdulaziz MAlthunayan MAlzahrani Tarek Kamel Fadaak Aiman Al-Solumany Saeed Bin Hamri Urology Department King Saud Medical CityRiyadhSaudi Arabia Urology Department Faculty of MedicineTanta UniversityTantaEgypt Devision of Urology King Abdullah International Medical Research CenterCollege of MedicineKing Abdulaziz Medical CityKing Saud Bin Abdulaziz University for Health ScienceDivision of UrologyKing Abdulaziz Medical CityRiyadhSaudi Arabia Urology Department Faculty of MedicineKing Abdulaziz UniversityJeddahSaudi Arabia Department of Surgery College of MedicineKing Saud University and King Saud University Medical CityRiyadhSaudi Arabia Urology Department Price Sultan Military Medical CityRiyadhSaudi Arabia Urology Department King Fahd HospitalImam Abdulrahman Bin Faisal UniversityDammamSaudi Arabia Urology Department King Fahd HospitalJeddahSaudi Arabia

Objective:To identify the impact of COVID-19 on endourology surgical practice in Saudi ***:A retrospective study of seven tertiary hospitals from January 2019 to April 2019,and from January 2020 to April 2020 was *** of urology outpatient department(OPD)visits and endourology procedures in the first third of 2020 were analyzed and compared with those in the first third of 2019,as well as,during the full curfew time,*** 2020 versus April ***:Number of OPD visits in the first third of 2020 and 2019 were 19499 and 26594,respectively(p75%,including OPD visits and elective endourology *** hospitals have changed their strategic preventive measures by increasing the rate of teleclinics and day surgeries.

关键词： COVID-19 Endourology Saudi Arabia

The Role of Bcl-2, CD10 and CD34 Expression in Differentiation between Basal Cell Carcinoma and Trichoepithelioma

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Open Journal of Pathology 2014年第3期4卷 116-124页

作者： Sayed abdel raheem Rabee Alsahaer Alsayed Tealeb Emad Rushdy Pathology Department Faculty of Medicine Al-Azhar University Cairo Egypt

Background: Basal cell carcinoma (BCC) and trichoepithelioma (TE) have some similarities clinically and histologically. The aim of this work is to evaluate the role of Bcl-2, CD10 and CD34 in differentiation between BCC and TE. Methods: The immunohistochemical expression of Bcl-2, CD10 and CD34 was evaluated in 20 BCCs and 12 TEs in a retrospective study. The localization of these markers in tumor and stromal cells was determined and comparison between BCC and TE was done. Immunohistochemistry for Bcl-2, CD10 and CD34 was performed on sections obtained from formalin-fixed, paraffin-embedded blocks. Bcl-2, CD10 and CD34 immunoreactivity in the stromal and/or tumor cells was determined as follows: negative (0);1+ (10% - 50% positive cells);and 2+ (>50% positive cells). Results: In BCC (20 cases), the expression of Bcl-2 in stromal cells showed (0) immunoreactivity in 8 cases (40%), (1+) immunoreactivity in 7 cases (35%), and (2+) immunoreactivity in 5 cases (25%). Tumoral cells showed diffuse positivity in 20 out of 20 cases (100%), (1+) immunoreactivity in 5 cases (25%) and (2+) immunoreactivity in 15 cases (75%). On the other hand, the expression of Bcl2 in TE, 4 cases showed positive stromal cells out of 12 (33.33%), (1+) immunoreactivity in 2 cases (16.6%) and (2+) immunoreactivity in 2 cases (16.6%), and 8 cases showed no immunoreactivity. Tumoral cells showed positivity in 12 out of 12 cases (100%), (1+) immunoreactivity in 5 cases (41.6%), (2+) immunoreactivity in 7 cases (58.3%). In BCC cases, the expression of CD10 was noted in stromal cells in 8 out of 20 cases (40%), 5 cases showed positivity in stromal and basaloid cells and 3 cases showed positivity in stromal cells only, and 12 cases showed no immunoreactivity (60%). Tumor cells showed positivity in 11 cases out of 20 (55%), (1+) immunoreactivity in 6 cases (30%), (2+) in 5 cases (25%), and 9 cases showed no immunoreactivity (45%). On the other hand, the expression of CD10 in TE 7 cases showed positive s

关键词： Basal Cell Carcinoma Trichoepithelioma Bcl-2 CD10 CD34

Assessing the Impact of the Lead/Lag Times on the Project Duration Estimates in Highway Construction

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Journal of Architectural Environment & Structural Engineering Research 2021年第3期4卷 47-62页

作者： Mohamed abdel-raheem Jennifer Reyes Xiaohui Wang Grecia Silva Sanchez Alyssa Marie Garza Department of Civil Engineering University of Texas Rio Grande ValleyEdinburgTX78539the U.S. School of Mathematical&Statistical Sciences University of Texas Rio Grande ValleyEdinburgTX78539the U.S.

The literature mentions multiple factors that can affect the accuracy of estimating the project duration in highway construction,such as weather,location,and soil ***,there are other factors that have not been explored,yet they can have significant impact on the accuracy of the project time ***,TxDOT raised a concern regarding the importance of the proper estimating of the lead/lag times in project *** lead/lag times are often determined based on the engineer’s ***,inaccurate estimates of the lead/lag time can result in unrealistic project *** order to investigate this claim,the study utilizes four time sensitivity measures(TSM),namely the Criticality Index(CI),Significance Index(SI),Cruciality Index(CRI),and the Schedule Sensitivity Index(SSI)to statistically analyze and draw conclusions regarding the impact of the lead/lag time estimates on the total duration in highway *** Excel-based scheduling software was developed with Monte Carlo simulation capabilities to calculate these *** results from this paper show that the variability of some lead/lag times can significantly impact the accuracy of the estimated total project *** was concluded that the current practices used for estimating the lead/lag times are *** such,it is recommended to utilize more robust methods,such as the time sensitivity measures,to accurately estimate the lead/lad times in the projects scheduled.

关键词： Scheduling Highway projects Lead Lag Time sensitivity measures