One of the most important phenomenon that occurs in sheet metal forming processes is the spring-back, which causes several geometrical alterations in the parts. The accurate prediction of springback after bending unloading is the key to the tool design, operation control, and precision estimate concerning the part geometry. This study investigated experimentally the effect of pretension in three rolling direction (0, 90, 45 degree) on the springback behavior of the yellow brass, sheet under V shape bending die. The pre-tension ranges from five different levels starting of 11% to 55% from the total strain in each rolling direction by regular increase of 11 %, then bent on a V-die 90 degree for the springback estimate. From experiment the results revealat that the springback increment with increase pretension ratio and the springback in 45° rolling direction is considerable than the sbringback in 90° rolling direction and the springback in 90° is greater than the sbringback in 0° rolling direction.
The nuclear structure of some cobalt (Co) isotopes with mass number A=56-60 has been studied depending on the effect of some physical properties such as the electromagnetic properties effects, such as, elastic longitudinal form factors, electric quadrupole moments, and magnetic dipole moments. The fp model space is used to present calculations using GXFP1 interaction by adopting the single particle wave functions of the harmonic oscillator. For all isotopes under consideration, the 40Ca nucleus is regarded as an inert core in fp model-space, while valence nucleons are moving through 1f7/2, 2p3/2, 1f5/2, and 2p1/2 orbits. The effects of core-polarization are obtained by the first orde
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Mechanism of Arbitration in the Stock Exchange Disputes
The world is moving towards greening business in general and production systems in particular. At the same time, economic units seek to enhance their productivity and find any variables that can contribute to improving their elements. Economic units should not ignore the green dimension of cost management techniques because of its role in containing the green dimension of the production system and the product. However the few researches dealt with the subject of the green kaizen showed its role in reducing costs and improving the environment. Those researches did not address its contribution to raising the level of productivity. Productivity is an important indicator of economic units that expresses their level of success and progre
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In this paper, the static analysis for finding the best location of boxes inside the composite wing-box structure has been performed. A software ANSYS (ver.11) was used to analyses the Aluminum wing to find the maximum stresses reached in. These results are used as a base for the composite wingbox to find the numbers of layers and location of the box beam and its dimensions so that the composite wingbox may carry the same loading conditions in the Aluminum wing. Analysis showed that a composite wingbox having two boxes is better than the single or triple boxes wing based on stress to weight ratio. Mass saving of (40%) had been achieved when composite wing-box is used instead of Aluminum wing.
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The aim of the research is to identify the attitudes of Iraqi youth
towards volunteering work by using the survey method and the scale
tool to identify what young volunteers can carry from the attitudes
towards volunteering work because the phenomenon of volunteer
work is of great importance in society. The scale was applied to
(525) volunteers among Iraqi youth. The research reached a set
of results, the most prominent of which is the existence of positive
trends among young people towards volunteering work, meaning
that Iraqi youth volunteers have awareness of the concept of
volunteering correctly. As for their goals of volunteering, they are
humanitarian and social goals for the advancement of society, an
In order to reduce the losses due to evaporation in the stored crude oil and minimizing the decrease in °API many affecting parameters were studied (i.e. Different storage system, namely batch system with different types of storage tanks under different temperatures and:or different pressures). Continuous circulation storage system was also studied. It was found that increasing pressure of the inert gas from 1 bar to 8 bar over the surface of the crude oil will decrease the percentage losses due to evaporation by (0.016%) and decrease the change of °API by (0.9) during 96 hours storage time. Similarly using covering by surfactant (potassium oleate) or using polymer (polyurethane foam) decreases the percentage evaporation losses compare
... Show MoreThis study aims to discuss how English Language Textbook (ELT), used in Iraqi schools, can be developed. All Iraqi teachers in Iraq spend much time using ELT textbooks in classrooms, and most of the Iraqi students depend on these textbooks to learn and improve the English language, so choosing an appropriate ELT textbook is so essential. A suitable book must include critical components that fit teachers' and students' needs. The quality of ELT textbooks has been improved dramatically in recent years, even though these textbooks still do not meet students' needs, especially in language communication skills. This study seeks to investigate the most critical components that may make the ELT textbooks are more influential and interactive for Ir
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