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The effect of composite bonding spot size and location on the performance of poly-ether-ether-ketone (PEEK) retainer wires
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Background: Poly-ether-ether-ketone(PEEK) has been introduced to many dental fields. Recently it was tested as a retainer wire‎ following orthodontic treatment. This study aimed to investigate the effect of changing the bonding spot size and location on the performance of PEEK retainer wires. Methods: A biomechanical study involving four three-dimensional finite element models was performed. The basic model was with a 0.8 mm cylindrical cross-section PEEK wire, bonded at the center of the lingual surface of the mandibular incisors with 4 mm in diameter composite spots. Two other models were designed with 3 mm and 5 mm composite sizes. The last model was created with the composite bonding spot of the canine away from the center of the crown, closer to the lateral incisor. The linear displacement of the teeth, strains of the periodontal ligament, and stresses in PEEK wire and composite were evaluated. The data was numerically produced with color coded display by the software. Selected values were tabulated and compared among models. Results: The amount of linear displacement and strain was very low. Stresses in the wire and composite were affected by the size and position of the composite bonding spot. The safe limits were identified at 235 MPa for PEEK and 100 MPa for composite. The basic model had a von Mises stress in the PEEK wire of 122.09 MPa, and a maximum principal stress in the composite of 99.779 MPa. Both stresses were within the safe limits, which means a lower risk of failure in PEEK and composite. All other models had stresses that exceeded the safe limit of the composite. The 3 mm composite model was the only one that developed stresses in the wire more than the safe limits of PEEK. Conclusions: Within the limitations of this study, bonding PEEK wires with 4 mm bonding spots to the clinical crown center provided the best mechanical performance of the wires and spots; otherwise, the mechanical properties of the wire and composite would be affected and, therefore, might affect the retention process. Keywords: Retention, PEEK, Finite element analysis

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Publication Date
Tue May 17 2016
Journal Name
J. Of College Of Education For Women
The Sufferings Of Afro-American Maids in Kathryn Stockett's The Help
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Publication Date
Wed Dec 30 2015
Journal Name
College Of Islamic Sciences
Approvals of the Imam nuclear for Iraqis Through the student platform
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The research was titled: Approval of the Imam of the Nuclear of Iraqis through the curriculum of the students.
The research revolves around the study of the weight of the imam nuclear jurisprudence in which the views of the Iraqi jurists of the Imam Shafi'i agreed through the book of students' approach to the nuclear imam, the research included a brief translation of the nuclear imam, and the definition of his place in the Shafi'i school, and then the definition of Iraqi jurists and then study the jurisprudence The course of research is only three issues, and compared with the views of imams, and the statement of the most correct opinion, and God and the conciliator.
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Publication Date
Thu Jan 10 2013
Journal Name
Asian Journal Of English Studies
The Use of Restrictive Relative Clauses in Letters to the Editors
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A restrictive relative clause (RRC hereafter), which is also known as a defining relative clause, gives essential information about a noun that comes before it: without this clause the sentence wouldn’t make much sense. A RRC can be introduced by that, which, whose, who, or whom. Givon (1993, 1995), Fox (1987), Fox and Thompson (1990) state that a RCC is used for two main functions: grounding and description. When a RRC serves the function of linking the current referent to the preceding utterance in the discourse, it does a grounding function; and when the information coded in a RRC is associated with the prior proposition frame, the RRC does a proposition-linking grounding function. Furthermore, when a RRC is not used to ground a new di

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Publication Date
Sun Sep 30 2001
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
New Development in the Process for the Production of Polybutadiene Rubber
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Publication Date
Thu Jun 01 2006
Journal Name
Modern Sport
Evaluating the level of controlling The Ball in Basketball for Youth
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The aim of this research was to evaluate the level of ball control in basketball. There was a great weakness in ball control that affected the mastery of many skills that affect the success of the team. The researcher also found a lack in training programs concerning ball control. The researchers used (9) special tests for ball control out of (41) test applied on young basketball players were (86). The researchers concluded that: 1. Criteria were set for test results of ball control. 2. A level of criteria was set for test results of ball control.

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Publication Date
Sat Apr 10 2021
Journal Name
Journal Of Legal Sciences
The role of the court in invoking danger in criminal proceedings
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The study of criminal danger is a part of a common phenomenon in criminal studies, namely, the conflict between traditional legal concepts and the new requirements of modern criminal policy, and the primacy of development and response to the requirements of modern human life. Criminal law scholars have recognized the importance of danger, especially after they have determined that the danger of crime is not limited to material damage, but rather to aggression against fundamental interests of the group, which is the possibility of damage. In particular, development and progress have led to the emergence of new areas in which the danger is the basis of the criminalization of related acts such as security, economy, trade, modern industries,

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Publication Date
Wed Feb 20 2019
Journal Name
Political Sciences Journal
Transitional justice in light of the change in the Arab region
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Many changes took place in a number of Arab countries, most of which ended with the change of the ruling leadership and a new coming. The same change brought about the hopes of the people to turn the page of the past into a democracy through which to overcome the grievances of previous years and achieve justice in all its aspects. The same new grievances have been added to that precedent and justice has not yet been achieved. Here we try to address the justice that is applied in the stages of change or transitional stages, which have been called, ie transitional justice, which has mechanisms and conditions of different application between countries, each of which the conditions applied in them and through a review of these mechanisms bet

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Publication Date
Sun Mar 01 2009
Journal Name
Journal Of Economics And Administrative Sciences
Use the method of parsing anomalous valueIn estimating the character parameter
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In this paper the method of singular value decomposition  is used to estimate the ridge parameter of ridge regression estimator which is an alternative to ordinary least squares estimator when the general linear regression model suffer from near multicollinearity.

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Publication Date
Wed Jun 29 2022
Journal Name
College Of Islamic Sciences
From the flags of The Koofic Grammar: Abdullah Al-Tuaal (243A.H)
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    This research has tackled a scientific figure belongs to Koofi grammatical school. He is Abdullah Al-Tuaal who has occupied the fourth layer among the Koofi grammarians. There was a confusion between him and another Koofi grammarian from the same layer (Mohammed Bin Qaadim) in some old references. This research has clarified this confusion to affirm that they are two different grammarians.This research also tackles the scientific status of Al-Tuaal and the grammatical views that have been ascribed to him in addition to the analysis and discussion of these views. All this in the light of what has been mentioned in grammar books about the issues in which these views were stated.

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Publication Date
Sun Jun 01 2014
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The impact of tax reform to increase the federal budget revenues
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The percentage contribution of tax revenue in the federal budget is verysmall compared with the revenue earned from oil revenues, as the dependenceon oil revenues mainly to finance the state budget, have a negative impact onthe national economy as it makes it a one-sided and prisoner of on revenue, thatis the revenue derived from oil which is unstable revenue for continuouschanging in the price of oil The oil revenues reached to (85.4%) in 2009 withpercentage (93.11%) in 2013, The research objective is to study the possibilityof increasing tax revenues in order to raise the proportion of its contribution infinancing the federal budget through effective tax reforms, The mainconclusion of the research is
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