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 progress of science in all its branches and levels made great civilized changes of
our societies in the present day, it's a result of the huge amount of knowledge, the increase of
number of students, and the increase of community awareness proportion of the importance of
education in schools and universities, it became necessary for us as educators to look at
science from another point of view based on the idea of scientific development of curricula
and teaching methods and means of education, and for the studying class environment as a
whole, by computer and internet use in education to the emergence of the term education
technology, which relies on the use of modern technology to provide educational content to<
Background: The use of the cone beam computed tomography for analysing the position of the greater palatine foramen in relation to various anatomical landmarks is crucial in dentistry. The aims of the current study, firstly is to determine the greater palatine foramen position in relation to various anatomical landmarks by using cone beam computed tomography and secondly is to make a comparison of the measurements according to side, gender, and age. Materials and methods: This prospective study included 60 Iraqi patients (28males and 32 females) who selected according to availability of Inclusion criteria, which include age range (21 - 60 years), with no dentofacial deformities or pathological lesion at the maxilla. All patients had inform
... Show MoreDifferent cooking conditions were examined for aluminum content in food cooked while wrapped with aluminum foil. The influence of each anticipated factor (the acidity of the cooking medium, type of acids normally used in cuisines namely acetic and tartaric acids, various cooking temperatures, influence of the presence of sodium chloride salt, the effect of cooking oil, and the length of time of cooking) was studied thoroughly as a function of aluminum degraded out of the aluminum foils to the medium. The experimental samples were digested with nitric acid upon fulfillment of examining each factor separately before quantifying aluminum with the sensitive technique of atomic absorption spectroscopy. The outcomes of the study have shown that t
... Show MoreThe usual methods of distance determination in Astronomy parallax and Spectroscopic with Expansion Methods are seldom applicable to Nebulae. In this work determination of the distances to individual Nebulae are calculated and discussed. The distances of Nebulae to the Earth are calculated. The accuracy of the distance is tested by using Aladin sky Atlas, and comparing Nebulae properties were derived from these distance made with statistical distance determination. The results showed that angular Expansions may occur in a part of the nebulae that is moving at a velocity different than the observed velocity. Also the results of the comparison of our spectroscopic distances with the trig
In this study, the Earth's surface was studied in Razzaza Lake for 25 years, using remote sensing methods. Images of the satellites Landsat 5 (TM) and 8 (OLI) were used to study and determine the components of the land cover. The study covered the years 1995-2021 with an interval of 5 years, as this region is uninhabited, so the change in the land cover is slow. The land cover was divided into three main classes and seven subclasses and classified using the maximum likelihood classifier with the help of training sets collected to represent the classes that made up the land cover. The changes detected in the land cover were studied by considering 1995 as a reference year. It was found that there was a significant reduction in the water mass
... Show MoreArt is a language in which the artist expresses himself, his society, and the events he lives in, so new artistic trends emerged, so the artist no longer practices his art as required by any previous artistic rules. And the thoughts wandering inside him, which led him to the abstract method in which the artist tries to employ the elements of the artwork in a plastic construction through which he achieves the relationships of the abstract form through the rhythms of lines, colors, spaces, shapes and textures without these plastic elements having any connection with the visual reality.
The research aims to find a new vision inspired by the school of geometric abstraction to enrich the field of Saudi plastic painting. And to take advan
E-learning applications according to the levels of enlightenment (STEM Literacy) for physics teachers in the secondary stage. The sample consists of (400) teachers, at a rate of (200) males (50%), and (200)females (50%), distributed over (6) directorates of education in Baghdad governorate on both sides of Rusafa and Karkh. To verify the research goals, the researcher built a scale of e-learning applications according to the levels of STEM Literacy, which consists of (50) items distributed over (5) levels. The face validity of the scale and its stability were verified by extracting the stability coefficient through the internal consistency method “Alf-Cronbach”. The following statistical means were used: Pearson correlation coefficient,
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