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.
תקציר
הילדות נחשבה השלב חשוב בתולדות האדם, וגם המשפיע ביותר בהיווצרות של אישיותו, משום שבו תתהווה את הליבה של ציוני דרך אישיותו של האדם, ויתגבש בו את ציוני דרכו ותכונותו שלו, וגם תשרטט את הבסיס העיקרי של מה יהיה האדם בעתיד. היות והילדות נשארה היא והשלכותיה בקרבו של האדם, עם זכרונותיה היפות והעצובים כאחד, במחקר זה עסקנו בילדותו של הסופר עמוס עוז כסיסמה לפענוח לדמותו, ולספרותו, כמו כן לכאבים שהעברו
... Show MoreOne of the troublesome duties in chemical industrial units is determining the instantaneous drop size distribution, which is created between two immiscible liquids within such units. In this work a complete system for measuring instantaneous droplet size is constructed. It consists of laser detection system (1mW He-Ne laser), drop generation system (turbine mixer unit), and microphotography system. Two immiscible liquids, water and kerosene were mixed together with different low volume fractions (0.0025, 0.02) of kerosene (as a dispersed phase) in water (as a continuous phase). The experiments were carried out at different rotational speed (1180- 2090 r.p.m) of the turbine mixer. The Sauter mean diameter of the drops was determined by la
... Show MoreThe current study aims to examine the level of problems faced by university students in distance learning, in addition to identify the differences in these problems in terms of the availability of internet services, gender, college, GPA, interactions, academic cohort, and family economic status. The study sample consisted of (3172) students (57.3% females). The researchers developed a questionnaire with (32) items to measure distance learning problems in four areas: Psychological (9 items), academic (10 items), technological (7 items), and study environment (6 items). The responses are scored on a (5) point Likert Scale ranging from 1 (strongly disagree) to 5 (strongly agree). Means, standard deviations, and Multivariate Analysis of Vari
... Show Moreمجتمع مدني ام مجتمع اهلي ؟ دراسة لواقع المجتمع المدني في البلدان العربية
We must live in an era dominated by the call for equality between men and women, in which the voices of advocates of gender integration were heard. After women opened their doors to compete with their brother, Knowledge, and culture in the various forms of life, language as a science of the time and knowledge of the other had to match this reality and express the most accurate expression of this task
Is astronomy in the Abbasid era one of the sciences that Muslims developed at that time? The restriction of students at the hands of a large number of students, which increased the development and increase the value of monitoring mechanisms and their outstanding efforts in support and development of the Arab civilization of Islam
التسليات في البلدان الاسلامية مشاهد حياة الطرب والالات الموسيقية كما يعكسها الفن
Abstract
The relationship between population and development is one of the most interrelated relations in contemporary societies. Therefore it is important focus on the demographic aspects of the population and its integration with developmental aspects, because the population is the makers of development and responsible for its success. The population composition and their qualitative composition are important factors in development. This change in age rate is because of demographic operations which lasted for long time. The change we are talking about is happing currently in Arab cou
... Show More
Strangeness in design generally and in advertisement design specifically is manifested in various images and creative propositions and shapes that depart the traditional and conventional framework to elevate design to virtual intellectual worlds related to the inspirational and imaginative range of the creative designer, which makes the forms of strangeness a means for persuasion and astonishment which achieves the functional and aesthetic objectives of the advertisement. The two researchers identified the research question "what is the concept of strangeness in the commercial advertisements design? The research objective has been determined by identifying the concept of strangeness in the commercial advertisement design. Strangen
... Show More
