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.
CdSe alloy has been prepared successfully from its high purity elements. Thin films of this alloy with different thicknesses (300,700)nm have been grown on glass substrates at room temperature under very low pressure (10-5)Torr with rate of deposition (1.7)nm/sec by thermal evaporation technique, after that these thin films have been heat treated under low pressure (10-2)Torr at (473,673)K for one hour. X-ray patterns showed that both CdSe alloy and thin films are polycrystalline and have the hexagonal structure with preferential orientation in the [100] and [002] direction respectively. The optical measurements indicated that CdSe thin films have allowed direct optical energy band gap, and it increases from (1.771.84) eV and from (1.6-1
... Show MoreMixedآ catechol- آ salicyladiminenate derivatives of antimony
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(III) and tin (IV) of the general formula M(cate)L"]X, [where:M= Sb, X= آ 0; آ M=Sn, آ X= آ Cl; آ cate=catechol; آ n=l, آ L=aniline, آ n=2, آ L=mآ bromo-aniline, n=3, L=p-bromoaniline] were prepared by the reaction of equimolar amount of [(cate)MCln], [where n=l آ or 2] with Nآ arylsalicylaldimines HOC6H4CH=NC6Hs (HL1آ , HOC6H4CH= NC6H4
This study was aimed to determine the impact of Conocarpus erectus L. compost fertilizer, and some micronutrients on growth and production of potato. This research was conducted at one of the fields of the College of Agricultural Engineering Sciences - University of Baghdad. The experiment was implemented using factorial arrangement (4X3X3) within randomized complete block design with three replicates. Conocarpus fertilizer was represented the first factor with three levels (7.5, 15, 30 ton.ha-1), which symbolized (C2, C3, C4). Chemical fertilizer as recommended dose as a control, which symbolized (C1). The second factor was foliar spraying with three levels of iron (0, 100, 200 mg.L-1), which symbolized (F0, F1, F2). The third fact
... Show MoreA plant mixture containing indigenous Australian plants was examined for synergistic antimicrobial activity using selected test microorganisms. This study aims to investigate antibacterial activities, antioxidant potential and the content of phenolic compounds in aqueous, ethanolic and peptide extracts of plant mixture
Well diffusion, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays were used to test antibacterial activity against four pathogenic bacteria namely
This work concerns the thermal and sound insulation as well as the mechanical properties of polymer matrix composite reinforced with glass fibers. These fibers may have dangerous effect during handling, for example the glass fibers might cause some damage to the eyes, lungs and even skin. For this reason the present work, investigates the behavior of polymer composite reinforced with natural fibers (Plant fibers) as replacement to glass fibers. Unsaturated Polyester resin was used as matrix material reinforced with two types of fibers, one of them is artificial (Glass fibers) and the other type is natural (Jute, Fronds Palm and Reed Fibers) by hand lay-up technique. All fibers are untreated with any chemical solvent. The Percentage of mi
... Show MoreNimodipine (NMD) is a dihydropyridine calcium channel blocker useful for the prevention and treatment of delayed ischemic effects. It belongs to class ? drugs, which is characterized by low solubility and high permeability. This research aimed to prepare Nimodipine nanoparticles (NMD NPs) for the enhancement of solubility and dissolution rate. The formulation of nanoparticles was done by the solvent anti-solvent technique using either magnetic stirrer or bath sonicator for maintaining the motion of the antisolvent phase. Five different stabilizers were used to prepare NMD NPs( TPGS, Soluplus®, HPMC E5, PVP K90, and poloxamer 407). The selected formula F2, in which Soluplus
has been utilized as a stabilizer, has a par
... Show MoreComplexes of Co(II),Ni(II),Cu(II)and Zn(II) with mixed ligand of 4 tributylphosphine (PBu3) were prepared in aqueous ethanol with (1:2:2) (M:L:PBu3)The prepared
RG Majeed, AS Ahmed, Jornal of Al-Muthanna for Agricultural Sciences, 2023
The study aims to follow modern methods in teaching rhythmic gymnastics skills by directing learners to develop their perceptions and absorb what the world deals with today and develop intelligence among learners, the researchers searched for the strengths of the learner by providing them with an opportunity to form their kinetic formation, hence the problem came by introducing a method of self-intelligence and social to guide the learner in the search for ways and solutions to overcome boredom and economy Time and effort in the educational process in learning and give them the freedom to express their ideas And their skills and here came the role of social and self-intelligence to teach the individual and collective kinetic formati
... Show MoreDelays and disruption are a common issue in both community and personal building programs The problem exists all throughout the world, but it is particularly prevalent in Iraq, where millions of dollars are squandered each time as a outcome. Delays and interruptions may have serious consequences not just for Iraq's construction plans, but also for the country's economic and social status. While numerous studies have been conducted to investigate the factors driving delays and disruption in Iraqi construction projects, slight consideration has been given to by what means project management implements and approaches have affected the occurrence of project delays and disruption. After analyzing the crucial reasons for delays and instability in
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