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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
Wed May 01 2024
Journal Name
Diamond And Related Materials
A comparative study on the effects of multi-walled carbon nanotubes and graphene nanoplates incorporated for improved thermal conductivity and dielectric properties of polyvinyl chloride
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Publication Date
Thu Jun 01 2017
Journal Name
Journal Of Economics And Administrative Sciences
The Trends of Fiscal Policy in bearing the financial burden of the government and the Extent Leadership in Iraq during the period 2004- 2014
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Abstract

There has been a heated controversy over the role the financial policy plays and how sufficient   it   is   in affording   the   financial   burden. This   burden   is   known as the operational   current expenses   which   the   governments   of   various countries mainly afford,   despite the   discrepancy   in   the   government’s   economic   policy.   After   the deterioration and deficit in the state budget in all countries nowadays, it was necessary to find an appropri

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Publication Date
Mon Apr 28 2025
Journal Name
مجلة علوم الرياضة
Building and codifying the Icelandic scale for coaches from the perspective of the aspirations of the Iraqi Premier League volleyball clubs
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The research aims: to build a measure of the cognitive competence of coaches from the point of view of players of Iraqi Premier League volleyball clubs and extract scores and standard levels for it. In order to achieve the objectives of the research, the descriptive method was used using the survey method. As for the research sample, it was chosen intentionally, and was represented by volleyball players for the Premier League 2024-2025. The sample was divided into exploratory, constructive, and standardizing, and starting the construction procedures, which included finding the scientific foundations for the scale, in addition to extracting the modified standard score and levels for the sample of the main experiment for standardization. Amou

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Publication Date
Sun Jun 30 2019
Journal Name
International Journal Of Research In Social Sciences And Humanities
CHARACTERISTICS OF THE POWER CHAIN FUNCTION CURVE AND ITS RELATION TO THE ACCURACY OF THE HIGH-JUMP JUMP IN THE HANDBALL
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The skill high-jump scoring is based on mechanical and physical abilities. The most important of all is the strength used by the player from the moment of preparation to the moment of scoring, which led the researchers to study the characteristics of the series of power chain functions of this skill according to (Biosyn System) The players of the national team's back line have a handball to find out the relationship between the properties of the power chain curve and the accuracy of the high jump to the upper and lower target angles. The aim of the research was to identify the values of the Force Series variables for the skill of the high-jump curve of the handball as well as the relationship between the properties of the power chain functi

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Publication Date
Wed Jun 30 2021
Journal Name
College Of Islamic Sciences
the Employing Quranic studies in the social aspect: (The verses of Hudud, the limit of murder and theft as a model)
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Research Summary

Praise be to God, and may blessings and peace be upon the Messenger of God. As for:

The Noble Qur’an is the constitution of life, and a comprehensive educational approach that deals with individuals comprehensively, as it organizes worldly and eschatological life, and it is a curriculum concerned with organizing life starting with individuals and the family until the establishment of states, and from its comprehensiveness is reform, guidance and establishing boundaries. They have a disease in their hearts. They are exposed to this and are trying, by falsehood, to subjugate the Islamic world with man-made laws set by the West. Their aim is to distance people from

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Publication Date
Wed Oct 17 2018
Journal Name
Journal Of Economics And Administrative Sciences
The use of the Principal components and Partial least squares methods to estimate the parameters of the logistic regression model in the case of linear multiplication problem
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Abstract

  The logistic regression model is one of the nonlinear models that aims at obtaining highly efficient capabilities, It also the researcher an idea of the effect of the explanatory variable on the binary response variable.                                                                                  &nb

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Publication Date
Wed Aug 17 2022
Journal Name
Al–bahith Al–a'alami
Lawyers’ Use of the Website of the Supreme Judicial Council and the Gratifications Obtained from It Drawn Research Submitted for the Study of the Higher Professional Diploma
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The field study of this paper focused on the motives for lawyers to use the website
of the Supreme Judicial Council, and the gratifications achieved as a result of its use.
This study sought to achieve a number of goals, including:
1. Monitoring the patterns of lawyers’ use of the website of the Supreme Judicial Council.
2. Determining the forms that lawyers use to interact on the website of the Supreme
Judicial Council.
This study is a descriptive in kind as the researcher relied on the ‘survey method’ in
its study of the external audience (lawyers) using the questionnaire and scale toolThe questionnaire was distributed among a deliberately chosen sample, consisting of
(160) lawyers who used the website of

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Publication Date
Sun Feb 10 2019
Journal Name
Iraqi National Journal Of Nursing Specialties
Self-Esteem and its Relationship with the Age, Gender and academic Achievement among the students of the south Iraq Colleges of Nursing
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Abstract
Objectives: this study aims to: (1). Assess self-esteem level and academic achievement for students of nursing colleges in southern Iraq. (2). Determine the relationship between levels of self-esteem and academic achievement of the student in the first semester. (3). Identify differences of self-esteem with gender and different age groups.
Methodology: a sample of (426 students) was purposively selected then collected by using a questionnaire which consisted of: I- Sociodemographic characteristics for assessing some important aspects of students, II- Rosenberg's Self-Esteem Scale (RSES) III- Iraq Grading Scale for assessing student achievement. Finally statistical analysis (SPSS) for data processing.
Results: study resu

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Publication Date
Tue May 01 2018
Journal Name
Journal Of Engineering
Performance enhancement of Echo Cancellation Using a Combination of Partial Update ( PU) Methods and New Variable Length LMS (NVLLMS) Algorithm
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In this paper, several combination algorithms between Partial Update LMS (PU LMS) methods and previously proposed algorithm (New Variable Length LMS (NVLLMS)) have been developed. Then, the new sets of proposed algorithms were applied to an Acoustic Echo Cancellation system (AEC) in order to decrease the filter coefficients, decrease the convergence time, and enhance its performance in terms of Mean Square Error (MSE) and Echo Return Loss Enhancement (ERLE). These proposed algorithms will use the Echo Return Loss Enhancement (ERLE) to control the operation of filter's coefficient length variation. In addition, the time-varying step size is used.The total number of coefficients required was reduced by about 18% , 10% , 6%

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Publication Date
Wed Jan 01 2014
Journal Name
Journal Of The College Of Languages (jcl)
EL ANÁLISIS DE ERRORES DEL LEÍSMO Y LAÍSMO EN EL PAPEL DIDÁCTICO PARA LOS ALUMNOS DEL DEPARTAMENTO ESPAÑOLEN LA FACULTAD DE LENGUAS EN IRAK Search Summary: The analysis of the mistakes of the personal pronouns in effect replaces him in the
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During the educational practices in the Spanish department at the Faculty of Languages ​​, University of Baghdad , we noticed that the personal pronouns in effect replaced by the direct and indirect characterized hardly be expressed , and the difficulty of her education.

Rationale: I chose this topic because the personal pronouns differ between the Spanish language and the Arabic language. We believe that this study may be useful not only for language teachers, but also for students, because it can contribute to a greater awareness of and correct weaknesses.

Objectives: To apply the model from which to address the problems in the use of personal pronouns Spanish , and the difference between effect of direct and indire

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