Six proposed simply supported high strength-steel fiber reinforced concrete (HS-SFRC) beams reinforced with FRP (fiber reinforced polymer) rebars were numerically tested by finite element method using ABAQUS software to investigate their behavior under the flexural failure. The beams were divided into two groups depending on their cross sectional shape. Group A consisted of four trapezoidal beams with dimensions of (height 200 mm, top width 250 mm, and bottom width 125 mm), while group B consisted of two rectangular beams with dimensions of (125 ×200) mm. All specimens have same total length of 1500 mm, and they were also considered to be made of same high strength concrete designed material with 1% volume fraction of steel fiber. Different types and ratios of FRP rebar were used to reinforce these test beams. The study’s principle variables were the amount and type of flexural reinforcement (glass FRP and basalt FRP) and beam cross-sectional shape (rectangular and trapezoidal). The load-deflection behavior and ultimate load capacity of the beams were studied and compared with one another under flexural test with symmetrical two-point loading. The results show that increasing the reinforcement ratio resulted in higher post cracking flexural stiffness, and higher residual strength, as well as caused an increase in the first cracking load and ultimate load capacity ranged from 3 to 16.9%, and 4.6 to 7.3% respectively. When the GFRP rebars replaced by BFRP, the overall beams flexural performance showed outstanding improvements. Moreover the results indicate that increasing the top width of the beam cross section led to a significant enhancement in the first crack load ranged from 16 to 32.4%, also a remarkable increases in the ultimate load capacity in the range of 35.5 to 35.8% were indicated in the trapezoidal beams compared to rectangular beams. However the results show that the deflections were similar and were approximately 1.07–1.54 mm for all test beams. It is worth noting that the general flexural behavior of all the test beams indicated a ductile behavior with a gradual reduction in strength and high residual strength pre to failure due to proposing steel fiber presence.
Apical meristems, lateral buds, anthers of immature flowers and immature embryos of chickpea ( Cicer arietinum L.) were cultured on MS media with different growth regulators and incubated for 6 weeks at 25-27?C with 16 hrs photoperiod for callus initiation. Results indicated that 1 and 0.1 mg/l of 2,4-D and BA were suitable for callus initiation when apical meristems and lateral buds were used. While 2 and 0.5 mg/l of both growth regulators were essential for immature embryos. It was noticed that using chickpea anthers of the MS medium must contain 1mg/l 2ip and 0.5 mg/l IAA. However, MS medium supplemented with 1-3 mg/l of BA and 2,4-D respectively was good for callus initiation from lateral buds, anther and immature embryos.
... Show MoreEssentilas of Atmospheric Sciences - ISBNiraq.org
Background: The aim of this study was to evaluate and compare the static frictional forces produced by monocrystalline ceramic (sapphire) bracket and polycrystalline ceramic bracket. Materials and methods: one hindered twenty brackets/segment of archwire combinations were used, each bracket/segment of archwire combination was tested 10 times. The tests were performed in a universal testing Instron machine. The data was submitted to in depended t-test. Results: The independent sample t-tests showed a highly significant difference in the static frictional forces between monocrystalline ceramic (sapphire) bracket and polycrystalline ceramic bracket. Conclusion: According to the biomechanical result gained from the present study, the monocryst
... Show Morein this worl three types of complexed phenolic resins were prepared using various additives such as and improving the aim of this work higher mechanical properties this work is done
Cesarean section, which was introduced into clinical practice as a lifesaving procedure for both the mother and the baby, is one of the most common surgeries performed in modern obstetrics. Formerly it was performed in interest of the mother; currently it is frequently done for fetal indication. As other procedures of some complexity, its use follows the health care inequity pattern of the world; underuse in low income setting, and adequate or even unnecessary use in middle and high income setting (1).
The first modern cesarean section was performed by German gynecologist Ferdinand Adolf Kehrer in 1881. Cesarean section is often performed when a vaginal delivery would put the baby's or mother's life or health at risk. Many are also pe
In this paper it is required to enhance the performance of a mechanical system (here: a Hoisting System) where it is preferred to lift a different payloads with approximately the same speed of lifting and keeping at the same time the good performance, and this of course needs some intelligence of the system which will be responsible on measuring the present load and taking into account the speed and performance desired in order to achieve the requirements or the criteria. The process therefore is a Mechatronics System design which includes a measuring system, a control or automation technique, and an actuating system. The criteria built here in this research using a given Hoist system's characteristics and parameters and changing one of
... Show MoreThe pioneer contributions included a sign for Iraqi Bryoflora were those of (Juratzka &
Milde) and Schiffner published at the end of the 19th century i.e. (1870 & 1897) respectively.
However, throughout the whole next century, the 20th, only few papers, by different authors,
have been published separately. They are Schiffner (1913); Handel-Mazzetti (1914); Froelich
(1959); Vondracek (1962 & 1965); Agnew &Townsend (1970); Agnew ( 1973 ) ; Agnew&
Vondracek (1975); Long (1979); Al-Ni’ma (1994). The most comprehensive work among
them was the “Moss Flora of Iraq” by Agnew & Vondracek (1975). It included a description
of 54 genera and 145 species with an identification key in addition to notes
This research aims at identifying the level of Reflective Judgment for University students in term of gender and stage. To this end, the researcher used Khaleel's scale (2016) for the Reflective Judgment. The scale was administered to the sample of the study which is (200) male and female level first-fourth university students. The results have shown that university students are on the level five of the Reflective Judgment, and the first-stage students have reflective judgment more than fourth-stage students. In the light of these results, the researcher has come with a number of recommendations and suggestions.
The reclamation of makeup water is studied in terms of breakthrough time (i.e., the leakage of the cations). Makeup water was subjected to lab-scale ion exchangers of two types: strong acid cation and weak base anion exchanger. The experimental investigation was directed to study the ion exchanger performance in terms of four different parameters (i.e., copper concentration, total dissolved solids (TDS), feed rate and bed depth). Box-Wilson composite rotatable design was adopted in designing the experiments. Breakthrough times of the effluent stream are measured in terms of copper concentration of 2 to 25 ppm, TDS concentration of 250 to 1250 ppm, feed rate of 0.38 to 5.34 l/h and bed depth of 5 to 70 cm. Simulation the effect of the stu
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