In this research, experimental and numerical studies were carried out to investigate the performance of encased glass-fiber-reinforced polymer (GFRP) beams under fire. The test specimens were divided into two peer groups to be tested under the effect of ambient and elevated temperatures. The first group was statically tested to investigate the monotonic behavior of the specimens. The second group was exposed to fire loading first and then statically tested to explore the residual behavior of the burned specimens. Adding shear connectors and web stiffeners to the GFRP beam was the main parameter in this investigation. Moreover, service loads were applied to the tested beams during the fire. Utilizing shear connectors, web stiffeners, and both enhanced the load-carrying capacities of the encased beams by 100.6%, 97.3%, and 130.8%, respectively. Comparisons between the burned and unburned peer beams were presented with losses in the load-carrying capacity of the burned beams. These losses were the highest in the cases of shear connectors and web stiffeners due to the obtained severe damage, which led to more reductions in the residual behavior of the burned beams. Numerical analyses were performed using the general-purpose finite element (FE) ABAQUS package to conduct a parametric study. The investigated parameters included the effect of the exposure duration and the temperature level. The results of the FE analysis showed good agreement with the experimental results. Additional reductions in the residual capacities of the fire-damaged beams were observed due to exposure to longer fire durations. The improvements in the beam capacities due to using shear connectors and web stiffeners relative to the reference beams under the same exposure time decreased as the exposure duration increased. Furthermore, increasing the temperature to 700 °C, 800 °C, 900 °C, and 950 °C caused reductions in the residual capacities by about 25%, 45%, 70%, and 80%, respectively, for the encased beams in comparison to their peers at ambient temperature.
« The emergence of satellite channels has led to fundamental changes in the supposed role of television, making it a center of culture and an important tributary to social upbringing and influencing the attitudes and values of individuals and in making public opinion regarding various issues, some television programs target ordinary people at home by virtue of the nature of their subjects, where there is a large audience of viewers, who consume and absorb what is offered to them from the cultural production of those satellite channels that play with the aspirations of groups of society to find metaphysical or magic solutions to their social problems or psychological delusions. The media, through its various messages, contributes to brin
... Show MoreThe present study was undertaken to study the effect of apigenin and luteolin on physiological and histological changes in rats treated with cytarabine drugs. Thirty-five albino healthy male adult rats with equal age weighing 250 -300g were enrolled. Rats were randomly divided into seven groups according to the treatment. Group “1” was treated with normal saline and served as the control group. Groups “2,3 and 4” received cytarabine, apigenin, and luteolin respectively, while groups 5, 6, and 7 received a combination of “apigenin + cytarabine”, “luteolin + cytarabine”, and “apigenin + luteolin + cytarabine”, respectively. After one week of treatment, all seven groups of rats were
... Show MoreIt is proposed and studied a prey-predator system with a Holling type II functional response that merges predation fear with a predator-dependent prey's refuge. Understanding the impact of fear and refuge on the system's dynamic behavior is one of the objectives. All conceivable steady-states are investigated for their stability. The persistence condition of the system has been established. Local bifurcation analysis is performed in the Sotomayor sense. Extensive numerical simulation with varied parameters was used to explore the system's global dynamics. A limit cycle and a point attractor are the two types of attractors in the system. It's also interesting to note that the system exhibits bi-stability between these 2 types of attractors.
... Show MoreSchiff Base And Ligand Metal Complexes of Some Amino Acids and Drug
This study was performed at Nuclear Radiation Hospital in Baghdad for the period from
January 2011 to May 2011. 44 Blood samples were collected from patients suffered lung and
bladder cancer and 24 samples as healthy control individuals.
Routine liver functions tests were studied by measuring S.GPT, S.GOT and Kidney
function was evaluated by estimation of blood urea and creatinine in serum samples of
individuals studied.
It was observed that the incidence of lung and bladder cancer was higher in males than
females patients ( male 81.82 %, 72.73%, female18 .18%, 27.27% respectively).
Insignificant difference was noted among age of lung and bladder cancer patients
compared with control group. The results
مجلة العلوم الاقتصادية والإدارية المجلد 18 العدد 69 الصفحات 318- 332 |