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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
Mon Jun 19 2023
Journal Name
Journal Of Engineering
Study the Impact Behavior of the Prosthetic Lower Limb Lamination Materials Due to Low Velocity Impactor
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This work involves three parts ,  first part  is manufacturing different types of laminated below knee prosthetic socket materials with different classical laminated materials used in Baghdad center for prosthetic and orthotic (4perlon layers+2carbon fiber layer+4 perlon layers) , two suggested laminated materials(3perlon layers+2carbon fiber layer+3 perlon layers) and (3perlon layers+1carbon fiber layer+3 perlon layers) ) in order to choose perfect laminated socket . The second part tests (Impact test) the laminated materials specimens used in socket manufacturing in order to get the impact properties for each socket materials groups using an experimental rig designed especially for this purpose. The interface pressure between

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Publication Date
Fri Dec 30 2022
Journal Name
Journal Of The College Of Education For Women
The Existential Psychological Crisis Among Battered Women to Non-Battered Women in the Republic of Yemen
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The research deals with a very important issue that affects women, an important segment of the society. This is because women are the basis of the family and the pillar of the society. Thus, the aim of the research is to examine the level and dimensions of the emotional and existential psychological crisis at the sample of the study. It further aims to investigate the statistical significant difference at the level of (0.05) regarding the feeling of the existential psychological crisis among battered and non-battered women. To reveal the objectives of the study, the researcher applied the existential psychological crisis scale to a sample of (72) women, divided into two groups: (35) battered women, who have been chosen purposefully. Thos

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Publication Date
Thu Dec 30 2021
Journal Name
College Of Islamic Sciences
Title of Thesis The creedal purposes deduced from the Almighty’s saying: {It is easy for me}
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 Summary

    I wanted to address this topic because of creedal purposes importance,and its r le in regulating lives of individuals and society, and to talk about purposes of Almighty's saying:{It is easy for me},to simplify its meanings for general educated person to obtain the believe of the Creator’s power and his oneness.

Therefore,this research came,whichincludes:an introduction and topics, first :concept of creedal objectives and their divisions,second: creedal purposes in Almighty’s saying:{It is easy for me},and conclusion:in where most important results were included:

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Publication Date
Wed Dec 11 2019
Journal Name
Journal Of The College Of Education For Women
Investigating Difficulties Faced by Iraqi EFL Learners in Identifying the Illocutionary Force of the Reduplicative Words
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A reduplicative word is an important phenomenon in all language studies because it reflects many functions in language communication such as plurality, emphasis, contrast, imitation.  The various instances of reduplicative words in a particular language reflect the richness and uniqueness of that language. Moreover, such variation gives insights into both culture and thought. A reduplicative word is a linguistic phenomenon found in the syntactic, morphological, phonological and semantic levels. The current study aims at investigating the illocutionary force of English reduplicative words in some selected English colloquial utterances. To achieve this aim, an analytical -pragmatic approach has been used by adopting Searle’s (1979)

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Publication Date
Thu Dec 26 2019
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Health insurance services in the sustainability of human resources: )Analytical study in the Iraqi insurance company)
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Health insurance and its benefits are of great importance and impact on the employees who represent the human capital of each organization because they are related to the health reality. The study took into account the most important and the last of his writing of the concepts and literary reviews and enriched the theoretical part of the practical side has addressed the financial data and analysis for the period from 2013 to 2017 to know the impact and the relationship between the variables that They were reviewed on the theoretical side. The study came out with a number of results, on the basis of which practical conclusions were drawn and reflected what was observed on the basis of which the recommendations were formulated

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Publication Date
Thu Apr 03 2025
Journal Name
Engineering, Technology & Applied Science Research
Application of the One-Step Second-Derivative Method for Solving the Transient Distribution in Markov Chain
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Markov chains are an application of stochastic models in operation research, helping the analysis and optimization of processes with random events and transitions. The method that will be deployed to obtain the transient solution to a Markov chain problem is an important part of this process. The present paper introduces a novel Ordinary Differential Equation (ODE) approach to solve the Markov chain problem. The probability distribution of a continuous-time Markov chain with an infinitesimal generator at a given time is considered, which is a resulting solution of the Chapman-Kolmogorov differential equation. This study presents a one-step second-derivative method with better accuracy in solving the first-order Initial Value Problem

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Publication Date
Mon Apr 04 2022
Journal Name
Journal Of Educational And Psychological Researches
Shaqra University's Role in Building the Mental Image of the Kingdom's Vision 2030 among Its Students
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The study problem is about the role of Shaqra University in building the mental image of the Kingdom’s 2030 vision among its female students. The study aims to examine the university’s role in providing information about the Kingdom’s 2030 vision, its role in shaping the vision’s image, the university’s role in the behavioral aspect of the vision, along with studying the extent of differences in answers of the sample individuals towards the study themes attributed to the personal variables. The researcher adopted the descriptive survey method. A sample of (1399) female students was used to achieve the study objectives. The results showed that university’s role in building the mental image of the Kingdom’s 2030 vision, among

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Publication Date
Wed Jul 17 2019
Journal Name
Aip Conference Proceedings
The correction of the line profiles for x-ray diffraction peaks by using three analysis methods
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In this study used three methods such as Williamson-hall, size-strain Plot, and Halder-Wagner to analysis x-ray diffraction lines to determine the crystallite size and the lattice strain of the nickel oxide nanoparticles and then compare the results of these methods with two other methods. The results were calculated for each of these methods to the crystallite size are (0.42554) nm, (1.04462) nm, and (3.60880) nm, and lattice strain are (0.56603), (1.11978), and (0.64606) respectively were compared with the result of Scherrer method (0.29598) nm,(0.34245),and the Modified Scherrer (0.97497). The difference in calculated results Observed for each of these methods in this study.

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Publication Date
Mon Nov 30 2020
Journal Name
Journal Of Economics And Administrative Sciences
Impact the Organizational downsizing in organizational health: Analytical research in the Directorate of Education in Nineveh
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This research aims to determine the extent of the contribution of organizational downsizing strategies to enhance the health of the researched organization represented by the Directorate of Education in Nineveh, and to achieve this goal, the study provided a simplified intellectual framework for the most important topics covered by writers and researchers for search variables, reinforced by an applied analytical framework for the opinions of (79) individuals responsible for the researched organization. The research adopted organizational downsizing as an independent variable that includes three dimensions represented by (reduction of human resources, job redesign, systemic strategy), while the organizational health represented th

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Publication Date
Sun Mar 01 2020
Journal Name
Baghdad Science Journal
The Efficacy of Poppy, Papaver nudicaule extract as an Anesthetic for the Common Carp, Cyprinus carpio
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Aqueous extract of poppy plant) Papaver nudicaule) with five concentrations (50, 100, 150, 200 and 250) mg/l were used to anesthetize fingerlings of the common carp Cyprinus carpio (Mean total length 8.91 ± 0.31 cm and mean total weight 7.72 ± 1.19 gm) instead of the traditional use of MS-222. Results showed that extracted solution of poppy have partial and overall anesthesia effect on these fishes with inverse relationship between the concentrations used and the time needed to reach partial and overall anesthesia, and also direct relationship between concentrations used and time needed for fish recovery. Best results were obtained by using a concentration of 250 mg/l, where time for partial anesthesia was 8 ± 1.52 m

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