This study expands the state of the art in studies that assess torsional retrofit of reinforced concrete (RC) multi-cell box girders with carbon fiber reinforced polymer (CFRP) strips. The torsional behavior of non-damaged and pre-damaged RC multi-cell box girder specimens externally retrofitted by CFRP strips was investigated through a series of laboratory experiments. It was found that retrofitting the pre-damaged specimens with CFRP strips increased the ultimate torsional capacity by more than 50% as compared to the un-damaged specimens subjected to equivalent retrofitting. This indicated that the retrofit has been less effective for the girder specimen that did not develop distortion beforehand as a result of pre-loading. From experimental observations, when the girder specimen was cracked and the transverse steel reinforcement bars started straining, the CFRP strips started to work more effectively and contributed together with the transverse steel reinforcement to resist torsion load. Additionally, Finite Element (FE) simulations were developed using Abaqus to model the torsional behavior of the retrofitted girders, the results of which were validated with the experimental data. With the numerical model, the effect of concrete compressive strength, transverse reinforcement spacing, and CFRP strip spacing were examined. The effectiveness of the CFRP strips in enhancing the torsional strength of the girder was found to increase with increasing the spacing between the transverse reinforcement.
he paper presents the results of exposure of normal concrete to high temperatures (400 and 700°C). In addition to the exposure of steel reinforcement bar Ø 12 mm, where two types of steel reinforcement burning situations were performed. Directly exposed to high temperatures (400 and 700°C) and others were covered by concrete layer (15 mm). From the experimental results of fire exposure for 1 hour of 400 and 700°C and gradually cooled, it was found that the residual average percentage of compressive strength of concrete was 85.3 and 41.4%, while the residual average percentage of modulus of elasticity of concrete was 75 and 48%, respectively. The residual average percentage of yielding tensile stress (Ø 12 mm) after burning and cooling
... Show More4, 4s (pyridine 2, 6 diylbis (1, 3, 4 oxadiazole 5, 2 diyl)) bisphenol monomer (3) was synthesized from cyclization of Ns2, Ns6 bis (4 hydroxybenzylidene) pyridine 2, 6 dicarbohydrazide (2) in the presence of bromine in glacialacetic acid. Newly five polymers (P1P5) were synthesized from reaction bis 1, 3, 4 oxadiazole bisphenolmonomer with five different di acid chloride. The antibacterial activity of the synthesized polymers was screened against gram positive and gram negative bacteria. Polymers P4 and P5 exhibited significant antibacterial against all microorganisms, as well these polymers showed highest antifungal activity.
In situ gel can be defined as a polymer solution administered as a liquid and when exposed to some physiologic condition such as thepH, ionic, temperature modulation or solvent and UV induced gelation undergo to phase transition to a semisolid gel. Ketotifenfumarate belongs to the histamine H1 receptor antagonists, and Ketotifen fumarate is used in the treatment of allergic conditions likeconjunctivitis and rhinitis. This work aims to study the natural polymer effects (xanthan gum,gellan gum) on the properties of pH-trigger in situ ocular gel, then compared the drug-releasing rate of optimized formula with the market ketotifen eye drop. Eightformulations (F1-F8) were prepared using different concentrations of xanthan gum, gellan gum with ca
... Show MoreIn this study, high-performance solid polymer electrolytes (SPEs) with different compositions were investigated for next-generation lithium-based energy storage and flexible electronics technology applications. The SPE films were prepared by the solution casting method using hydroxypropyl methylcellulose (HPMC), polyethylene glycol (PEG), and lithium sulfate (Li2SO4 ). The obtained films were flexible and transparent, hence suitable for structural, optical, electrical, and thermal characterizations. The XRD pattern of HPMC indicated a broad peak at 2 theta approximate to 20 degrees, while the films HPMC/PEG- Li2SO4 showed sharp peaks assigned to the crystalline nature of Li2SO4 . Fourier-transform infrared (FTIR) spectra confirmed O-H vibra
... Show MoreSeeds of five cultivars of oats (Avena sativa) were introduced from Italy in 2009. Seeds were propagated on the farm of the Dept. of Field Crops Sci. / Coll. of Agric. / Univ. of Baghdad in the season 2009 – 2010. The cultivars Anatolia, Alguda, Hamel, Pimula and Genzania were planted under 3 irrigation intervals; 3, 4 and 5 weeks to give water depth of 480, 400 and 320 mm, respectively . The depth of water was 80 mm each irrigation. A factorial experiment with RCBD of 4 replicates was conducted in 2 consecutive seasons in 2010 – 2011 and 2011 – 2012. The cultivar Alguda gave highest grain yield (8.07 t/ ha) under 480 mm, and 7.02 t / ha average of 3 water depths. This cultivar was characterized by high growth rate (13.2 g/m2/ d) that
... Show MoreEthanol as a solvent, a precursor of titanium isopropoxide and a stabilizer of either hydrochloric acid or ammonium hydroxide was used to prepare a titanium dioxide aqueous solution. The aqueous solutions with different values of pH and the morphology of the resultant reaction of the nanoparticles of titanium dioxide were investigated. The X-ray diffraction showed that at low temperatures and with acidic solutions, rutile structures are more favorable to grow on titanium dioxide synthesized, while at low and average temperatures and with base solutions, anatase phase is more pronounced. The crystalline form and the re-confirmation of the crystallite size growth were observed by the scanning electron microscopy. The atomi
... Show MoreStatic and dynamic circumstances confirm that seepage is water movement through the earth dam’s embankment’s voids from upstream to downstream. Seepage is a quantity of fluid that has seeped through the permeable material or as the infiltration downward and lateral movement of water into soil or substrata from a source of supply such as a reservoir of a dam. In case of an earthquake strikes saturated soils, the water-filled pore spaces collapse, reducing the soil’s overall volume. The water pressure between individual soil grains is increased as a result of this action, and the grains can then move freely in the watery matrix. This reduces the soil’s resistance to shear str
Ethanol as a solvent, a precursor of titanium isopropoxide and a stabilizer of either hydrochloric acid or ammonium hydroxide was used to prepare a titanium dioxide aqueous solution. The aqueous solutions with different values of pH and the morphology of the resultant reaction of the nanoparticles of titanium dioxide were investigated. The X-ray diffraction showed that at low temperatures and with acidic solutions, rutile structures are more favorable to grow on titanium dioxide synthesized, while at low and average temperatures and with base solutions, anatase phase is more pronounced. The crystalline form and the re-confirmation of the crystallite size growth were observed by the scanning electron microscopy. The atomic force micr
... Show MoreThe study aims to review the literature on the fundamental changes in Managerial Accounting (MA) in light of accelerating Digital Transformations (DT) and increasing Sustainability Requirements (SR) from 2020 to August 2025, with the purpose of informing researchers and professionals about recent developments. The study relied on a qualitative analysis of the content of a group of studies indexed in the Scopus database. The study included a literature review of topics such as artificial intelligence tools and techniques, cloud computing, linear programming, sustainability reporting, and strategic managerial accounting practices. The study results revealed that accelerated DT improves the efficiency of managerial accounting practices
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