Seismic pounding effects on adjacent buildings in series with different alignment configurations

Shehata E. Abdel Raheem,Mohamed Y.M. Fooly,Aly G.A. Abdel Shafy,Yousef A. Abbas,Mohamed Omar,Mohamed M.S. Abdel Latif,Sayed Mahmoud 국제구조공학회 2018 Steel and Composite Structures, An International J Vol.28 No.3

Numerous urban seismic vulnerability studies have recognized pounding as one of the main risks due to the restricted separation distance between neighboring structures. The pounding effects on the adjacent buildings could extend from slight non-structural to serious structural damage that could even head to a total collapse of buildings. Therefore, an assessment of the seismic pounding hazard to the adjacent buildings is superficial in future building code calibrations. Thus, this study targets are to draw useful recommendations and set up guidelines for potential pounding damage evaluation for code calibration through a numerical simulation approach for the evaluation of the pounding risks on adjacent buildings. A numerical simulation is formulated to estimate the seismic pounding effects on the seismic response demands of adjacent buildings for different design parameters that include: number of stories, separation distances; alignment configurations, and then compared with nominal model without pounding. Based on the obtained results, it has been concluded that the severity of the pounding effects depends on the dynamic characteristics of the adjacent buildings and the input excitation characteristics, and whether the building is exposed to one or two-sided impacts. Seismic pounding among adjacent buildings produces greater acceleration and shear force response demands at different story levels compared to the no pounding case response demands.

Tensile Properties and Fracture Characteristics of ECAP-Processed Al and Al-Cu Alloys

Mohamed Ibrahim Abd El Aal,Nahed El Mahallawy,Farouk A. Shehata,Mohamed Abd El Hameed,윤은유,이정환,김형섭 대한금속·재료학회 2010 METALS AND MATERIALS International Vol.16 No.5

In the present paper, billets of pure Al, and cast-homogenized Al-2 wt.%, 3 wt.%, and 5 wt.% Cu alloys were successfully processed by equal channel angular pressing (ECAP) up to 10 passes without fracture at room temperature using a die with a channel angle of 110o. Giant strains imposed on workpieces lead to extreme dislocation densities, microstructural refinement, and finally ultrafine grained materials. Tensile tests were employed to examine the fracture modes and fracture surface morphologies of the ECAP-processed Al and Al-Cu alloy samples. In particular, the effects of the number of ECAP passes and the Cu content were investigated.

The role of hesperidin in ameliorating retinal changes in rats with experimentally induced type 1 diabetes mellitus and the active role of vascular endothelial growth factor and glial fibrillary acidic protein

Azza Saad Shehata,Dalia Abduelmoein Mohamed,Sherein Mahmoud Hagras,Shimaa Mohsen El-Beah,Heba Mohamed Elnegris 대한해부학회 2021 Anatomy & Cell Biology Vol.54 No.4

Patients with type 1 diabetes mellitus (T1DM) are vulnerable to developing diabetic retinopathy even under insulin therapy. Thus, this study was designed to evaluate the efficacy of hesperidin and insulin in rats with T1DM compared with insulin alone in improving diabetic retinal changes. Eighty rats were divided into four equal groups: group I, control rats without diabetes; group II, untreated rats with diabetes; group III, rats with diabetes treated daily with subcutaneous (SC) doses of long-acting insulin; and group IV, a rat with diabetes in which hesperidin was orally administered with SC insulin. The animals were assessed histologically, morphometrically, and biochemically. In group II, the thickness of all retinal layers decreased histologically. Ultrastructurally, degenerated retinal neurons and congested blood vessels were observed. Immunostaining detected elevated gene expression of advanced glycation end products. Gene expression of vascular endothelial growth factor, and glial fibrillary acidic protein were elevated. In this study, hesperidin supplementation with insulin significantly improved the retinal histological changes, supported by morphometric findings, compared with insulin alone. Moreover, treatment with hesperidin significantly reduced malondialdehyde and elevated serum antioxidant markers, including superoxide dismutase and catalase; furthermore, glutathione peroxidase decreased. Hesperidin might be an effective supplement for improving diabetic retinal complications occurring even with insulin treatment.

Ileo-uterine fistula in a degenerated posterior wall fibroid after Caesarean section

Shehata, Ayman,Hussein, Naglaa,El Halwagy, Ahmed,El Gergawy, Adel,Khairallah, Mohamed The Korean Society for Reproductive Medicine 2016 Clinical and Experimental Reproductive Medicine Vol.43 No.1

Uterine fibroids are benign tumors of the myometrium with a diverse range of manifestations. Fibroids can dramatically increase in size during pregnancy due to the increase in estrogen levels. After delivery, the fibroids usually shrink back to their pre-pregnancy size. Uterine myomas may have many complications, including abnormal uterine bleeding, infertility, pressure on nearby organs, degeneration, and malignant transformation. No previous reports have indicated that a fistula may develop between a uterine fibroid and the bowel loops, although previous studies have documented the occurrence of fistulas from the uterus to the bowel following myomectomy or uterine artery embolization performed to treat a myoma. In our case report, we document the rare complication of a fistula occurring between a degenerated myoma in the posterior wall and the ileum 1 week postoperatively in a patient who underwent a Caesarean section but did not have a history of uterine artery embolization.

Sustainable super fast adsorptive removal of Congo red dye from water by a novel technique based on microwave-enforced sorption process

Mohamed E. Mahmoud,Azza E.H. Abdou,Aziza K. Shehata,Heba M.A. Header,Ezzat A. Hamed 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.57 No.-

Removal of Congo red was completed in 5–20 s using microwave-enforced sorption (MES) as a sustainable technique. Nano-γ-Al2O3 was covalently bonded with 3-chloropropyltrimethoxysilane to produce γ-Al2O3-SiCl nanosorbent via microwave-assisted approach. Congo red extraction by γ-Al2O3 and γ-Al2O3-SiCl were found 58.42% and 69.41% and increased to 66.13% and 81.47%, respectively using 5 and 20 s of microwave heating. The percentage extraction of Congo red (30 mg L−1) by γ-Al2O3-SiCl was increased from 46.21% to 83.61% upon increasing the pH from 1.0 to 10.0. Other controlling conditions were investigated and optimized. Excellent recovery of Congo red from wastewater was established in 20 s.

A case report of congenitally abnormal rabbitheaded stillbirth Najdi lamb

Mohamed M.M. Elsokary,Seham, F. Shehata,Islam M. Saadedin 한국동물생명공학회(구 한국동물번식학회) 2020 Journal of Animal Reproduction and Biotechnology Vol.35 No.3

The congenital head anomalies are most often used to describe defects in the eyes, mouth, nose, skull, and or brain. The faulty embryogenesis most likely found to be associated with abnormal genetic or epigenetic causes during pregnancy. Eventually it leads to congenital anomalies. Rabbit-headed Lamb (RH) is a disorder in sheep breeding that is characterized by some deformities in the head and the face. A dead –day old- crossbred white Najdi lamb with a deformed face and head was reported to be born in the current case. The external and physical examination revealed a deformed skull and facial region with a unilateral eye, fused mouth, piglike nose, and patent skull with the brain coming out from left eye orbit. Additionally, the lamb was very skinny with unusual long extremities. This is the first report of this syndrome that describes such deformities in a stillbirth Najdi breed lamb.

Seismic response evaluation of fixed jacket-type offshore structures by random vibration analysis

Shehata E. Abdel Raheem,Elsayed M. Abdel Aal,Aly G.A. AbdelShafy,Mohamed F.M. Fahmy 국제구조공학회 2022 Steel and Composite Structures, An International J Vol.42 No.2

Offshore platforms in seismically active areas must be designed to survive in the face of intense earthquakes without a global structural collapse. This paper scrutinizes the seismic performance of a newly designed and established jacket type offshore platform situated in the entrance of the Gulf of Suez region based on the API-RP2A normalized response spectra during seismic events. A nonlinear finite element model of a typical jacket type offshore platform is constructed taking into consideration the effect of structure-soil-interaction. Soil properties at the site were manipulated to generate the pile lateral soil properties in the form of load deflection curves, based on API-RP2A recommendations. Dynamic characteristics of the offshore platform, the response function, output power spectral density and transfer functions for different elements of the platform are discussed. The joints deflection and acceleration responses demands are presented. It is generally concluded that consideration of the interaction between structure, piles and soil leads to higher deflections and less stresses in platform elements due to soil elasticity, nonlinearity, and damping and leads to a more realistic platform design. The earthquake-based analysis for offshore platform structure is essential for the safe design and operation of offshore platforms.

A case report of congenitally abnormal rabbit-headed stillbirth Najdi lamb

Elsokary, Mohamed M.M.,Shehata, Seham F.,Saadedin, Islam M. The Korean Society of Animal Reproduction and Biot 2020 한국동물생명공학회지 Vol.35 No.3

The congenital head anomalies are most often used to describe defects in the eyes, mouth, nose, skull, and or brain. The faulty embryogenesis most likely found to be associated with abnormal genetic or epigenetic causes during pregnancy. Eventually it leads to congenital anomalies. Rabbit-headed Lamb (RH) is a disorder in sheep breeding that is characterized by some deformities in the head and the face. A dead -day old- crossbred white Najdi lamb with a deformed face and head was reported to be born in the current case. The external and physical examination revealed a deformed skull and facial region with a unilateral eye, fused mouth, pig-like nose, and patent skull with the brain coming out from left eye orbit. Additionally, the lamb was very skinny with unusual long extremities. This is the first report of this syndrome that describes such deformities in a stillbirth Najdi breed lamb.

Effects of numerical modeling simplification on seismic design of buildings

Raheem, Shehata E Abdel,Omar, Mohamed,Zaher, Ahmed K Abdel,Taha, Ahmed M Techno-Press 2018 Coupled systems mechanics Vol.7 No.6

The recent seismic events have led to concerns on safety and vulnerability of Reinforced Concrete Moment Resisting Frame "RC-MRF" buildings. The seismic design demands are greatly dependent on the computational tools, the inherent assumptions and approximations introduced in the modeling process. Thus, it is essential to assess the relative importance of implementing different modeling approaches and investigate the computed response sensitivity to the corresponding modeling assumptions. Many parameters and assumptions are to be justified for generation effective and accurate structural models of RC-MRF buildings to simulate the lateral response and evaluate seismic design demands. So, the present study aims to develop reliable finite element model through many refinements in modeling the various structural components. The effect of finite element modeling assumptions, analysis methods and code provisions on seismic response demands for the structural design of RC-MRF buildings are investigated. where, a series of three-dimensional finite element models were created to study various approaches to quantitatively improve the accuracy of FE models of symmetric buildings located in active seismic zones. It is shown from results of the comparative analyses that the use of a calibrated frame model which was made up of line elements featuring rigid offsets manages to provide estimates that match best with estimates obtained from a much more rigorous modeling approach involving the use of shell elements.

Validity and Reliability of the Arabic Version of the Copenhagen Neck Functional Disability Scale in Neck Pain Patients

Ahmed Mohammed Elbeltagy,Wadida Hassan El Sayed,Soheir Shehata Rezk Allah 대한척추외과학회 2018 Asian Spine Journal Vol.12 No.5

Study Design: Prospective observational study. Purpose: To test the face validity, content validity, feasibility, internal consistency, reliability, and test–retest reliability of the Arabic version of the Copenhagen Neck Functional Disability Scale (CNFDS). Overview of Literature: CNFDS is a clinical evaluation tool that accurately reflects the patient’s perception regarding his/her functionality with existing cervical pain. This study aimed to investigate the validity and reliability of the Arabic version of the CNFDS in measuring the disability level in chronic neck pain patients. Method: Seventy-four patients with neck pain were recruited, and 135 sheets (test and retest sheets) were completed by patients; two expert panels (each comprising ten experts) participated in this study. Arabic translation (forward translation), development of the preliminary translated version, English translation (backward translation), development of the prefinal version, and testing of the prefinal version was performed by experts; thereafter, the final version was tested on patients. Index of clarity, expert proportion of clearance, index of content validity (CVI), expert proportion of relevance, descriptive statistics, missed item index, Cronbach’s alpha, and Spearman’s rank correlation coefficient were used for statistical analyses. Results: The study revealed that the scale index of clarity was 86.84%, scale CVI was 99.33%, scale-level content validity index (universal agreement method) was 99.33%, 99.15% of the scale items were filled in all sheets, the scale was answered in less than 3 minutes in about 75% cases, Cronbach’s alpha was 0.856 (0.796, 0.905), and all Spearman’s correlations between the test and retest results were statistically significant. Conclusions: The Arabic version of the CNFDS has adequate validity and reliability for the measurement of the disability level in chronic neck pain patients.