Partial Confinement Utilization for Rectangular Concrete Columns Subjected to Biaxial Bending and Axial Compression

Ahmed M. Abd El-Fattah,Hayder A. Rasheed,Ahmed H. Al-Rahmani 한국콘크리트학회 2017 International Journal of Concrete Structures and M Vol.11 No.1

The prediction of the actual ultimate capacity of confined concrete columns requires partial confinement utilization under eccentric loading. This is attributed to the reduction in compression zone compared to columns under pure axial compression. Modern codes and standards are introducing the need to perform extreme event analysis under static loads. There has been a number of studies that focused on the analysis and testing of concentric columns. On the other hand, the augmentation of compressive strength due to partial confinement has not been treated before. The higher eccentricity causes smaller confined concrete region in compression yielding smaller increase in strength of concrete. Accordingly, the ultimate eccentric confined strength is gradually reduced from the fully confined value fcc (at zero eccentricity) to the unconfined value f 0 c (at infinite eccentricity) as a function of the ratio of compression area to total area of each eccentricity. This approach is used to implement an adaptive Mander model for analyzing eccentrically loaded columns. Generalization of the 3D moment of area approach is implemented based on proportional loading, fiber model and the secant stiffness approach, in an incremental-iterative numerical procedure to achieve the equilibrium path of P–e and M–u response up to failure. This numerical analysis is adapted to assess the confining effect in rectangular columns confined with conventional lateral steel. This analysis is validated against experimental data found in the literature showing good correlation to the partial confinement model while rendering the full confinement treatment unsafe.

Immune Defense of Rats Immunized with Fennel Honey, Propolis, and Bee Venom Against Induced Staphylococcal Infection

S.M. Sayed,Ghada A. Abou El-Ella,Nahed M. Wahba,Neveen A. El Nisr,Khaled Raddad,M.F. Abd El Rahman,M.M. Abd El Hafeez,Ahmed Abd El Fattah Aamer 한국식품영양과학회 2009 Journal of medicinal food Vol.12 No.3

The objective of this work was to evaluate the potency of bee product-immunized rats to overcome an induced Staphylococcus aureus infection. Forty rats were divided to eight groups: T1, T3, and T5 received, respectively, fennel honey, ethanol, and aqueous propolis extracts orally, and T2, T4, and T6 were administered the respective materials intraperitoneally; T7 received bee venom by the bee sting technique; and T8 was the control group. All groups were challenged by a bovine clinical mastitis isolate of S. aureus. Each rat received 2mL of broth inoculated with 1×105 colony-forming units/mL intraperitoneally. Two weeks post-induced infection all rats were sacrificed and eviscerated for postmortem inspection and histopathological study. Three rats from T8 and one rat from T7 died before sacrifice. Another two rats, one each in T4 and T5, had morbidity manifestations. The remaining experimental animals showed apparently healthy conditions until time of sacrifice. Postmortem inspection revealed that all T8 rats showed different degrees of skeletal muscle and internal organ paleness with scattered focal pus nodules mainly on lungs and livers. All rats of the treated groups showed normal postmortem features except three rats. A dead rat in group T7 showed focal pus nodules on the lung surface only, whereas the affected two rats in groups T4 and T5 appeared normal except with some pus nodules, but much smaller than in the control, scattered on the hepatic surface and mesentery. Histopathological studies revealed that T8 rats had typical suppurative bronchopneumonia and or severe degenerative and necrobiotic changes in hepatic tissues. Three affected rats of the treated groups showed slight bronchopneumonia or degenerative hepatic changes only. The other animals of the treated groups showed completely normal parenchymatous organs with stimulated lymphatic tissues. It was concluded that all tested previously bee product-immunized rats could significantly challenge the induced S. aureus infection (P<.01). The effects were more pronounced in rats that had received fennel honey solution.

Immune Defense of Rats Immunized with Fennel Honey, Propolis, and Bee Venom Against Induced Staphylococcal Infection

Sayed, S.M.,El-Ella, Ghada A. Abou,Wahba, Nahed M.,Nisr, Neveen A. El,Raddad, Khaled,Rahman, M.F. Abd El,Hafeez, M.M. Abd El,Aamer, Ahmed Abd El Fattah The Korean Society of Food Science and Nutrition 2009 Journal of medicinal food Vol.12 No.3

The objective of this work was to evaluate the potency of bee product-immunized rats to overcome an induced Staphylococcus aureus infection. Forty rats were divided to eight groups: T1, T3, and T5 received, respectively, fennel honey, ethanol, and aqueous propolis extracts orally, and T2, T4, and T6 were administered the respective materials intraperitoneally; T7 received bee venom by the bee sting technique; and T8 was the control group. All groups were challenged by a bovine clinical mastitis isolate of S. aureus. Each rat received 2mL of broth inoculated with $1{\times}10^5$ colony-forming units/mL intraperitoneally. Two weeks post-induced infection all rats were sacrificed and eviscerated for postmortem inspection and histopathological study. Three rats from T8 and one rat from T7 died before sacrifice. Another two rats, one each in T4 and T5, had morbidity manifestations. The remaining experimental animals showed apparently healthy conditions until time of sacrifice. Postmortem inspection revealed that all T8 rats showed different degrees of skeletal muscle and internal organ paleness with scattered focal pus nodules mainly on lungs and livers. All rats of the treated groups showed normal postmortem features except three rats. A dead rat in group T7 showed focal pus nodules on the lung surface only, whereas the affected two rats in groups T4 and T5 appeared normal except with some pus nodules, but much smaller than in the control, scattered on the hepatic surface and mesentery. Histopathological studies revealed that T8 rats had typical suppurative bronchopneumonia and or severe degenerative and necrobiotic changes in hepatic tissues. Three affected rats of the treated groups showed slight bronchopneumonia or degenerative hepatic changes only. The other animals of the treated groups showed completely normal parenchymatous organs with stimulated lymphatic tissues. It was concluded that all tested previously bee product-immunized rats could significantly challenge the induced S. aureus infection (P < .01). The effects were more pronounced in rats that had received fennel honey solution.

Partial Confinement Utilization for Rectangular Concrete Columns Subjected to Biaxial Bending and Axial Compression

Abd El Fattah, Ahmed M.,Rasheed, Hayder A.,Al-Rahmani, Ahmed H. Korea Concrete Institute 2017 International Journal of Concrete Structures and M Vol.11 No.1

The prediction of the actual ultimate capacity of confined concrete columns requires partial confinement utilization under eccentric loading. This is attributed to the reduction in compression zone compared to columns under pure axial compression. Modern codes and standards are introducing the need to perform extreme event analysis under static loads. There has been a number of studies that focused on the analysis and testing of concentric columns. On the other hand, the augmentation of compressive strength due to partial confinement has not been treated before. The higher eccentricity causes smaller confined concrete region in compression yielding smaller increase in strength of concrete. Accordingly, the ultimate eccentric confined strength is gradually reduced from the fully confined value $f_{cc}$ (at zero eccentricity) to the unconfined value $f^{\prime}_c$ (at infinite eccentricity) as a function of the ratio of compression area to total area of each eccentricity. This approach is used to implement an adaptive Mander model for analyzing eccentrically loaded columns. Generalization of the 3D moment of area approach is implemented based on proportional loading, fiber model and the secant stiffness approach, in an incremental-iterative numerical procedure to achieve the equilibrium path of $P-{\varepsilon}$ and $M-{\varphi}$ response up to failure. This numerical analysis is adapted to assess the confining effect in rectangular columns confined with conventional lateral steel. This analysis is validated against experimental data found in the literature showing good correlation to the partial confinement model while rendering the full confinement treatment unsafe.

Software for adaptable eccentric analysis of confined concrete circular columns

Hayder A. Rasheed,Ahmed M. Abd El-Fattah,Asad Esmaeily,John P. Jones,Kenneth F. Hurst 사단법인 한국계산역학회 2012 Computers and Concrete, An International Journal Vol.10 No.4

This paper describes the varying material model, the analysis method and the software development for reinforced concrete circular columns confined by spiral or hoop transverse steel reinforcement and subjected to eccentric loading. The widely used Mander model of concentric loading is adapted here to eccentric loading by developing an auto-adjustable stress-strain curve based on the eccentricity of the axial load or the size of the compression zone to generate more accurate interaction diagrams. The prediction of the ultimate unconfined capacity is straight forward. On the other hand, the prediction of the actual ultimate capacity of confined concrete columns requires specialized nonlinear analysis. This nonlinear procedure is programmed using C-Sharp to build efficient software that can be used for design, analysis, extreme event evaluation and forensic engineering. The software is equipped with an elegant graphics interface that assimilates input data, detail drawings, capacity diagrams and demand point mapping in a single sheet. Options for preliminary design, section and reinforcement selection are seamlessly integrated as well. Improvements to KDOT Bridge Design Manual using this software with reference to AASHTO LRFD are made.