Structural buildings consist of concrete and steel, and these buildings have confronted many challenges from various aggressive environments against the materials manufactured from them. It contains high water levels and buildings whose concrete cover may be damaged and thus lead to the deterioration and corrosion of steel. It was important to have an alternative to steel, such as the glass fiber reinforced polymer (GFRP), which is distinguished by its great effectiveness in resisting corrosion, as well as its strong tensile resistance. Still, one of its drawbacks is that it has a low modulus of elasticity. This research article aims to conduct a numerical study using the nonlinear finite element ABAQUS program on eight beam models with various parameters such as stirrup spacing, compressive strength, reinforcement layer, and type of bar reinforcement under four-point bending. The result shows that the ultimate load capacity of the GFRP beam is higher than that of a beam reinforced with steel and the number and width of cracks are greater in the GFRP-reinforced beam than in the steel-reinforced beam. In general, the serviceability reflected by cracks and deflection is lower in GFRP-reinforced beams than in steel-reinforced beams with higher serviceability. The results, on either hand, showed the expected behavior of GFRP, which is linear elastic to the failure stage. These beams are divided into four groups of beams with different variables studied to understand GFRP bars’ behavior under static loading. The variables taken in this study are the spacing between the stirrups, the compressive strength of concrete, the effect of the number of layers of reinforcement, and the type of reinforcement bar.
Background: Numerous methods have been described for achievement of Intermaxillary fixation in the treatment of fractures of facial skeleton. Conventional methods like Erich arch bars and eyelet wires are currently the most common methods for achieving intermaxillary fixation (IMF), however, they have their own disadvantages. Since 1989, IMF using intraoral self-tapping IMF screws has been introduced for treatment of mandibular fractures. The aim of this study was to evaluate the efficacy, advantages, disadvantages and potential complications associated with using of self-tapping IMF screws in the treatment of mandibular fractures. Material and Methods: Twenty patients with favorable mandibular fractures, attended to Oral and Maxillofacial
... Show MoreThe city of Samawah is one of the most important cities which emerged in the poverty area within the poverty map produced by the Ministry of Planning, despite being an important provincial centre. Although it has great development potentials, it was neglected for more than 50 years,. This dereliction has caused a series of negative accumulations at the urban levels (environmental, social and economic). Therefore, the basic idea of this research is to detect part of these challenges that are preventing growth and development of the city. The methodology of the research is to extrapolate the reality with the analysis of the results, data and environmental impact assessment of the projec
Four rapid, accurate and very simple derivative spectrophotometric techniques were developed for the quantitative determination of binary mixtures of estradiol (E2) and progesterone (PRG) formulated as a capsule. Method I is the first derivative zero-crossing technique, derivative amplitudes were detected at the zero-crossing wavelength of 239.27 and 292.51 nm for the quantification of estradiol and 249.19 nm for Progesterone. Method II is ratio subtraction, progesterone was determined at λmax 240 nm after subtraction of interference exerted by estradiol. Method III is modified amplitude subtraction, which was established using derivative spectroscopy and mathematical manipulations. Method IIII is the absorbance ratio technique, absorba
... Show MoreThe study of homomorphisms in cubic sets is considered one of the important concepts that transfer algebraic properties between different structures, so we study a homomorphism of a cubic set of a semigroup in a KU-algebra and defined the product of two cubic sets in this structure. Firstly, we define the image and the inverse image of a cubic set in a KU-semigroup and achieve some results in this notion. Secondly, the Cartesian product of cubic subsets in a KU-semigroup is discussed and some important characteristics are proved.
In this paper we generalize Jacobsons results by proving that any integer in is a square-free integer), belong to . All units of are generated by the fundamental unit having the forms
our generalization build on using the conditions
This leads us to classify the real quadratic fields into the sets Jacobsons results shows that and Sliwa confirm that and are the only real quadratic fields in .
It is known that the oral administration of ibuprofen caused an irritation of stomach as a side effect due to its carboxylic moiety. Ibuprofen ester was synthesized by linking the carboxylic moiety of ibuprofen and the hydroxylic group of paracetamol to reduce its side effect. Study the kinetic hydrolysis of prepared ester was examined at different values of physiological pH (1.0, 5.8, 6.4 and 7.4) at 37 ± 0.1 of 1 hour period. Measurements of absorbance were carried out by UV-Visible spectrophotometer to follow the stability of ester, it showed Pseudo first order hydrolysis. The pH- apparent rate profiles of ester was exhibited a good stability at pH 1.0 and pH 5.8. Pharmacological activity in vivo of prepared ester was evaluated in re
... Show MoreBackground: The aim of the study was to investigate the effect of surface treatments of zirconia (grinding and sandblast with 50μm, 100 μm) on shear bond strength between zirconia core and veneering ceramic. Material and methods: Twenty-eight presintered Y-TZP ceramic specimens (IPS e.max ZirCAD, Ivoclar vivadent) were fabricated and sintered according to manufacturer’s instructions. The core specimens were divided randomly in to 4 groups, group 1: no surface treatment, group2: zirconia specimens were ground with silicon carbide paper up to1200 grit under water cooling, group3: zirconia specimens were ground and sandblast with 100 μm alumina, group 4: zirconia specimens were ground and sandblast with 50 μm alumina. Surfa
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