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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
Thu Sep 04 2014
Journal Name
Journal Of Al-nahrain University
Effect of Some Insecticides on the Egg Parasitoid, Trichogramma evanescens Westwood(Hymenoptera: Trichogrammatidae)
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Publication Date
Thu May 31 2012
Journal Name
Al-khwarizmi Engineering Journal
Restrained Edges Effect on the Dynamics of Thermoelastic Plates under Different End Conditions
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Frequency equations for rectangular plate model with and without the thermoelastic effect for the cases are: all edges are simply supported, all edges are clamped and two opposite edges are clamped others are simply supported.   These were obtained through direct method for simply supported ends using Hamilton’s principle with minimizing Ritz method to total energy (strain and kinetic) for the rest of the boundary conditions. The effect of restraining edges on the frequency and mode shape has been considered. Distributions temperatures have been considered as a uniform temperature the effect of developed thermal stresses due to restrictions of ends conditions on vibration characteristics   of a plate with different

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Publication Date
Mon Mar 07 2022
Journal Name
Journal Of Educational And Psychological Researches
The Effect of KUD Strategy on Acquiring Grammatical Concepts among First Intermediate Students
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The research aims to examine the effect of KUD strategy on acquiring the grammatical concepts among intermediate school students. To achieve the research objective, the researcher adopted the null hypothesis in which there is no statistically significant difference at the level (0.05) between the average scores of students of the experimental group who study grammar base on the KUD strategy and the average scores of the control group who study the grammar through the traditional way of acquiring grammatical concepts. In a random manner, the researcher selected the research sample from one of Baghdad’s education schools in al Rusafa / 2, as the total number of students of the two groups reached (67) students. They were divided into (33)

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Publication Date
Fri Jun 16 2023
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
The Possible Protective Effect of Cinnamic Acid on Ovalbumin-Induced Asthma in Mice
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Asthma is a chronic respiratory disorder in which immunological and structural cells play a role. The limits of conventional medicines necessitate the development of innovative therapeutic techniques for asthma. In the present study, we investigated the possible protective effect of cinnamic acid (CA) on ovalbumin-induced asthma in a mouse model. Sixty albino male mice BALB/c type weighing (20-30) grams were chosen at random and divided into five groups each one contains 12 animal: Group I: PBS/liquid paraffin control. Group II: asthma model group. Group III: cinnamic acid control group; mice received cinnamic acid (50 mg/kg) in liquid paraffin orally by gavage. Group IV: asthma model / group of (25 mg / kg) cinnamic acid; mice received

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Publication Date
Tue Feb 19 2019
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The Federal Board of Supreme Audit and Role in the Assessment of Tax Performance: An Applied Research in The General Commission of Taxes
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The success of any institution must be based on means to protect its resources and assets from the waste, loss, misuse and the availability of accurate and reliable data by accounting reports to increase its operational efficiency, namely, that the internal control system is considered as a safety valve for top management in any economic unit. The problem is represented by the need for an efficient system, so to ensure its success, there must exist external parties which monitor and evaluate the performance because of its importance by following clear criteria. So, the research problem came to address performance evaluation indicators which are set by the Federal Board of Supreme Audit (FBSA) and identify the extent of its contribution t

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Publication Date
Fri Jan 19 2024
Journal Name
Eximia
Job pressures affecting the quality of teachers’ performance at the College of Physical Education and Sports Sciences/University of Baghdad
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The research aimed to prepare a measure of job stressors affecting the quality of teaching performance in the College of Physical Education and Sports Sciences at the University of Baghdad, to identify their levels, if any, and the most influential dimensions on the quality of teaching performance within the college’s work environment, as well as the deanship’s ability to help prevent and Alleviating its severity through logical administrative methods, on a scale that includes four dimensions that include (the administrative and financial environment, the organizational environment, the social and humanitarian environment, and the scientific and research environment). The descriptive approach was adopted using the case study met

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Publication Date
Sun Oct 30 2022
Journal Name
Revista Iberoamericana De Psicologia Del Ejercicio Y El Deporte
THE EFFECT OF (HIT) TRAINING ON IMMUNE GLOBULINS AND WHITE BLOOD CELLS FOR AMATEUR WEIGHTLIFTERS AFTER THE RETURN OF ACTIVITY FROM THE MANDATORY QUARANTINE FOR THE COVID-19 EPIDEMIC
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The aim of the research is to identify an appropriate training method that raises the levels of immune globulins (IgA, IgM, IgG) and white blood cells and the effect of training by (HIT) method using resistance (weights) as a training curriculum that increases immunity and ensures the continuation of the pills after the return of activity from the stone The response to the Covid-19 epidemic among amateur weightlifters, the researchers relied on the method of trace analysis in an experimental way by conducting a pre-, medial and post-test with the same experimental one agroup on a sample of amateur weightlifters in the Fury private hall for weightlifting and body building in Adhamiya, the number of sample members reached (15 players) who int

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Scopus
Publication Date
Wed Feb 25 2026
Journal Name
Wasit Journal Of Sports Sciences
The motivational characteristic and its relationship to the performance of the court defense skill among Baghdad University volleyball team players
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Publication Date
Wed Jun 14 2023
Journal Name
Al-academy
The mechanisms of the actor's work between performance and directing style in the contemporary theater show (Western) as a model
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The actor has mechanisms that were applied in the performance، as it formed a style in the theatrical form (weird)، and the researcher deliberately studied these mechanisms and divided them into four chapters.

The researcher divided it into two sections، the first is the actor's performance requirements، and the second is the boring performance methods in the directors' theater، and then the researcher concluded the second chapter with the most important indicators.

As for the third chapter، the researcher determined the society of his research and the method of selecting the sample (strange) and analyzing the sample and concluded with the most important results of the sample analysis.

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Publication Date
Wed Jan 02 2019
Journal Name
Journal Of Educational And Psychological Researches
Evaluation Tasks of Performance Quality of the University Students According to the Developmental Environment
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 Education is a process of learning and education at the same time. As the conditions of modern life necessitate every person to keep learning, education has become a necessity to meet life needs. The society today is concerned with the educational process and aims to live up the expectations. Since education is an integral part of education and its means, it has become as a mean to achieve its purposes. The educational environment was a traditional environment limited to specific inputs, possibilities and stimulus of both teacher and student. Due to the latest advancement, the educational environment has been expanded to become a rich, with strong connections. It has expanded to encompass the entire global environment. The current

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