Investigation of Production Possibilities of Radiobromines for Diagnostic and Therapeutic Applications

I. Spahn,M. M. Shehata,S. Spellerberg,B. Scholten,H. H. Coenen,S. M. Qaim,G. F. Steyn,C. Vermeulen,Z. Kovacs,F. Szelecsenyi 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.59 No.23

The lighter, positron emitting isotopes ^(75)Br and ^(76)Br have already been in use for some time in molecular imaging with PET. The two Auger electron emitters ^(77)Br and ^(80m)Br are of potential interest for internal radiotherapy. In this work new cross section measurements were done on nine (p,xn) reactions on enriched Se targets up to 80 MeV. Thin samples were irradiated in a stacked-foil arrangement. The produced radioactivity was measured non-destructively using HPGe detector γ-ray spectrometry. Concerning ^(80m)Br, a special low-energy HPGe detector was used. From the cross section data on the formation of ^(75)Br, ^(76)Br, ^(77)Br and ^(80m)Br their possible production yields have been deduced and the issue of radionuclidic purity is discussed. Whereas an efficient production of ^(75)Br is only achievable via intermediate energy reactions above 30 MeV, ^(76)Br and ^(77)Br can be produced both with proton energies below 25 MeV as well as with intermediate energy protons up to 70 MeV. The production of ^(80m)Br appears to be a good application of small accelerators.

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.

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.

Electrochemical behavior of Al2O3/Al composite coated Al electrodes through surface mechanical alloying in alkaline media

M.R. Ebrahim,O.S. Shehata,Amr H. Abdel Fatah 한국물리학회 2019 Current Applied Physics Vol.19 No.4

The behavior of Al2O3/Al composite coated Al electrodes fabricated by surface mechanical alloying ‘SMA’ was studied. The work was accomplished using Cyclic voltammetry and electrochemical impedance spectroscopy (EIS) techniques in alkaline media 2M KOH were done at room temperature. Results show hydroxyl ions accumulate on the surface due to Al deformation micro cavities filling with Al2O3 until full charge blockage reached. A barrier cover layer development causing an increase of both resistance and capacitance as it becomes more stable and thinner with exposure time increase. Migrating hydroxyl ion inside micro cavity changed its composition from Al2O3 to stable tetrahedral − Al (OH)4 aluminate ions. Therefore future benefits could be reached by developing such surfaces having charge accumulation that enables environmental interaction.

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.

STABILITY OF DELAY-DISTRIBUTED HIV INFECTION MODELS WITH MULTIPLE VIRAL PRODUCER CELLS

A. M. ELAIW,E. KH. ELNAHARY,A. M. SHEHATA,M. ABUL-EZ 한국산업응용수학회 2018 Journal of the Korean Society for Industrial and A Vol.22 No.1

We investigate a class of HIV infection models with two kinds of target cells: CD4+ T cells and macrophages. We incorporate three distributed time delays into the models. Moreover, we consider the effect of humoral immunity on the dynamical behavior of the HIV. The viruses are produced from four types of infected cells: short-lived infected CD4+T cells, long-lived chronically infected CD4+T cells, short-lived infected macrophages and long-lived chronically infected macrophages. The drug efficacy is assumed to be different for the two types of target cells. The HIV-target incidence rate is given by bilinear and saturation functional response while, for the third model, both HIV-target incidence rate and neutralization rate of viruses are given by nonlinear general functions. We show that the solutions of the proposed models are nonnegative and ultimately bounded. We derive two threshold parameters which fully determine the positivity and stability of the three steady states of the models. Using Lyapunov functionals, we established the global stability of the steady states of the models. The theoretical results are confirmed by numerical simulations.

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.

Wear properties of ECAP-processed ultrafine grained Al-Cu alloys

Abd El Aal, M.I.,El Mahallawy, N.,Shehata, F.A.,Abd El Hameed, M.,Yoon, E.Y.,Kim, H.S. Elsevier Sequoia 2010 Materials science & engineering. properties, micro Vol.527 No.16

The wear properties of equal channel angular pressing (ECAP) Al-2, 3 and 5%Cu alloys under dry sliding conditions using different sliding distances and loads were investigated by pin-on-disc dry sliding wear tests. The wear mass loss decreased remarkably as the number of ECAP passes and Cu content increased, being affected more by the sliding distance than by the applied load under the experimental conditions. The wear mechanism was observed to be adhesive and delamination initially, and an abrasive mechanism also appeared as the sliding distance increased. The analysis of the wear surface indicates a transfer of Fe from the rotating disc to the Al-Cu alloy pin with increases in the sliding distance, the applied load, the number of passes and the copper content.

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.

Structural performance assessment of fixed offshore platform based on in-place analysis

Raheem, Shehata E. Abdel,Aal, Elsayed M. Abdel,AbdelShafy, Aly G.A.,Mansour, Mahmoud H.,Omar, Mohamed Techno-Press 2020 Coupled systems mechanics Vol.9 No.5

In-place analysis for offshore platforms is essentially required to make proper design for new structures and true assessment for existing structures. The structural integrity of platform components under the maximum and minimum operating loads of environmental conditions is required for risk assessment and inspection plan development. In-place analyses have been executed to check that the structural member with all appurtenances robustness and capability to support the applied loads in either storm condition or operating condition. A nonlinear finite element analysis is adopted for the platform structure above the seabed and the pile-soil interaction to estimate the in-place behavior of a typical fixed offshore platform. The analysis includes interpretation of dynamic design parameters based on the available site-specific data, together with foundation design recommendations for in-place loading conditions. The SACS software is utilized to calculate the natural frequencies of the model and to obtain the response of platform joints according to in-place analysis then the stresses at selected members, as well as their nodal displacements. The directions of environmental loads and water depth variations have important effects on the results of the in-place analysis behavior. The result shows that the in-place analysis is quite crucial for safe design and operation of offshore platform and assessment for existing offshore structures.