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.
A novel series of chitosan derivatives were synthesized via reaction of chitosan with carbonyl compounds and grafted it’s by with different amine compounds substituted hydrogen. The produced polymers were characterized by different analyses FTIR, 1HCNMR, XRD, DSC and TGA. Solubility in water as well as many solvent was investigated, antibacterial activity of chitosan and its derivatives against two types of bacteria E. coli and S. aureus was also investigated. The results showed that derivatives sort of have antibacterial activities against Esherichia coli (Gram negative) better than chitosan whilst compound IX has better antibacterial against Staphylococcus aureus (Gram positive). SEM analysis showed that increase of surface roughness wi
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The aims of research is to identify the role of strategic human resource management Practices in organizational performance improvement in the Baghdad soft drinks company, as well as the implications of the results for both managers and practitioners.
In order to achieve the objectives of the research, the researcher designed questionnaire included (40) items to collect the initial data from the research sample consisting of (53) Single. In light of that has been collecting and analyzing data and test hypotheses using the statistical package for Social Sciences (SPSS21), and use a number of statistical methods to achieve the goal of the research, including the means, standard deviations and simple correla
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Receipt date:2/17/2021 acceptance date:3/16/2021 Publishing date:12/31/2021
This work is licensed under a Creative Commons Attribution 4.0 International License.
Objective: This paper investigates the contradictions in the decision-making process of the United States, which historically proven to be successful policies in the short term, but in the long term proven to be wanting and failure. Methodology: The paper uses descriptive, historical, comparative method. A
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The revolution of technology in the 21st century has changed radically the
climate of opinion concerning second language education. In order to excel in
today’s world, teachers and learners need to adopt new roles and be equipped with
new skills and competencies that go beyond the basic ones of listening, speaking,
reading, and writing; skills that cannot be gained if teachers teach mere academic
subjects, and students are evaluated on how well they have learnt the minute sub
skills in those content areas.
This session will touch upon several skills which may be considered the
new basics of the 21st century. Among these skills are: autonomy, active learning,
critical thinking, cooperative learning, and digita
Since its establishment, cities have been looking for a special urban architectural language that distinguishes them from other cities and expresses their distinctive identity through continuous products through time and controls the totality of temporal and spatial changes through a bridging dialogue that manages the language of the city correctly, Which gives the stability of that language and its ability to adapt to the total changes that occur in the city over time, and thus the possibility of producing ideas integrated series and ideas are renewed overlapping with the legacy and bear multiple layers of meaning and signals and symbols create a total of two meanings The problem of research (not comprehensive studies to create a contem
... Show MoreThe title of the research (the occasion in Surat Maryam) highlights the importance of the subject because he is studying Surah from the wall of the Koran, and that the best times of preoccupation with this light shown, study and thoughtful, and the reason for choosing the topic that the occasion of science helps in understanding the Almighty God in his book, and not Falling in confusion or error, or exaggerated interpretations, and be the key to knowing the rule of the Koran and repeating it, but the results of the conclusion that the occasion has many benefits: including making parts of speech taking each other's necks, strengthens that link and the authorship becomes his case in the case of tight construction , And that the occasion of
... Show MorePraise be to God, Lord of the worlds, and peace and blessings be upon our master Muhammad and his family and companions as follows:
This research examines altruism in the Noble Qur’an objectively. The altruism is a word that permeates selection, preference, presentation, types of gifts, and all other material and moral virtues. It is the highest level of generosity and generosity, provided that the consent of God Almighty is enriched on the consent of others, and that greatness arises in it, and that creation affects On yourself in what does not deprive you of a religion, and it does not cut you off on a path, because the praiseworthy altruism is only in relation to souls, not the disgraced altruism tha
In this research a recent developed practical modeling technique is applied for the glucose regulation system identification. By using this technique a set of mathematical models is obtained instead of single one to compensate for the loss of information caused by the optimization technique in curve fitting algorithms, the diversity of members inside the single set is interpreted in term of restricted range of its parameters, also a diagnosis criteria is developed for detecting any disorder in the glucose regulation system by investigating the influence of variation of the parameters on the response of the system, this technique is applied in this research practically for 20 cases with association of National Center for
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Objective(s): To evaluate housekeeping services staff work environment and their health status, as well as to determine the impact of the work environment upon their health status.
Methodology: A descriptive design is employed throughout the present study to evaluate housekeeping services staff work environment and their health status, as well as to determine the impact of the work environment upon their health status from November 3rd 2017 to June 30th 2018. A purposive “nonprobability” sample of (101) housekeeping staff is selected for the present study. An instrument is constructed for the purpose of the study and it is consists of (2) parts: (I) Evaluation of work environment, and (II) Evaluation of housekeeping st