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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 Apr 04 2022
Journal Name
Journal Of Educational And Psychological Researches
The Vocational Self of Educational Counselors
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The current research aims to identify the Vocational Self of the educational counselors as well as to identify the significant difference in the professional self according to the gender variable (male-female). The researcher adopted the scale of al-hasani (2015), which consisted of (34) items. It was applied to a sample of (300) school counselors (male-female) who were randomly selected from the six directorates in the Baghdad governorate for the academic year 2020/2021. The results showed that the research sample of educational counselors has a vocational self-concept. There are no statistically significant differences in the vocational self-concept between males and females among the educational counselors.

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Publication Date
Mon May 08 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
The Commutator of Two Fuzzy Subsets
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In this paper we introduce the idea of the commutator of two fuzzy subsets of a group and study the concept of the commutator of two fuzzy subsets of a group .We introduce and study some of its properties .

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Publication Date
Sat Jun 15 2019
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
The Evaluation of EDI Software Application
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The primary objective of this research is to determine the best EDI
software application that meets the users' requirements, and to show
the functionality potentially presented in any software of electronic
data interchange (EDI) system. Also, in this paper, will be addressed
issues relating to integration EDI system into business process, and
the issues regarding the performance of EDI application will also be
discussed

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Publication Date
Wed May 17 2023
Journal Name
College Of Islamic Sciences
Dignity in the books of faith
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The issue of dignity is one of the topics that do not pass as long as the earths and the heavens remain; Because the earth is not devoid of the righteous, the believers, the saints, and the pious, and these do not cease from them aid, dignity, insight, or good vision, and from here the authorship in this section was continuous; Because the people’s need for it is confirmed as time progresses, and in that, Ibn Taymiyyah says in the sum of his fatwas, “And from what it should be known is that dignities may be according to the man’s need, so if the weak needs them Faith or the needy, he is given from it what strengthens his faith and fulfills his needs, and he who is more complete is the guardianship of God than him. He is independent

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Publication Date
Fri Sep 22 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
The product of para - compact spaces
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The product  of   rn-paracompact and   rn-strongly  paracompact are briefly disc. ussed.

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Publication Date
Tue Jan 03 2023
Journal Name
College Of Islamic Sciences
The mechanism of managing religious difference
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The mechanism of managing religious difference

God is the Lord of the worlds, forget them and their jinn, Arabs and non-Muslims, He is the Lord of Muslims and Lord of non-Muslims, as He created them male and female despite their differences in tongues and colors, so He created them according to their diversity and distinction in beliefs and religions.

 To prevent flare-ups due to differences, the Lord of the worlds set limits that he has forbidden to cross, and draw clear maps as mechanisms for managing religious differences and lifting psychological barriers between the different, so that they can coexist in peace and freedom, each adhering to his faith, and practicing the rituals of his religion.

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Publication Date
Wed Dec 27 2017
Journal Name
Al-khwarizmi Engineering Journal
Stress Analysis of the Hip Bone
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The bony pelvis has a major role in weight transmission to the lower limbs. The complexities of its geometric form, material properties, and loading conditions render it an open subject to biomechanical analysis.

 The present study deals with area measurement, and three-dimensional finite element analysis of the hip bone to investigate magnitudes, load direction, and stress distribution under physiological loading conditions.

 The surface areas of the auricular surface, lunate surface, and symphysis pubis were measured in (35) adult hip bones. A solid model was translated into ANSYS parametric design language to be analyzed by finite element analysis method under different loading conditions.

The surface

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Publication Date
Sun Jun 01 2008
Journal Name
Journal Of The College Of Languages (jcl)
The Characteristics of English Linking Adverbials
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Linking adverbials are used to organize and bridge together extended stretches of discourse to make the text coherent. They are explicit indicators of the communicative function of the sentence and writers use them to let their readers follow what has already been said and to help them anticipate what is about to follow.
Linking adverbials include those relations of addition, enumeration, summation, apposition and so on. Through the use of these adverbials, the writer is able to organize and develop his ideas and help the reader follow him from one sentence to another. Thus, a linking adverbial is a semantic relation used to show the way in which what is to follow is systematically connected to what has gone before. So, they have anap

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Publication Date
Sun Sep 07 2014
Journal Name
Baghdad Science Journal
Organic Content in the Sediments of Tigris and Diyala Rivers, south of Baghdad, and its Relationship with some Environmental factors, Benthic Invertebrates Groups and Values of Diversity Indices
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This study was conducted to detect the relationship between organic content in the sediment of Rivers Tigris and Diyala, at two locations south of Baghdad, with some environmental factors and the benthic invertebrates and values of diversity indices. Monthly samples collected from the area for the period November 2007 to October 2008. Results showed differences in the physical and chemical characteristics of the two sites, Where the annual average in Tigris and Diyala were respectively for: water temperature (19, 20) C°, pH (8, 8), dissolved oxygen (4, 8) mg / l , Biochemical oxygen Demand BOD5 (3,44 ) mg/l, TDS (632,1585) mg / l, TSS (42, 44) mg / l, turbidity (28,74) NTU, and total hardness as CaCO3 (485,823) mg / l ,Sulfat

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Publication Date
Mon Dec 21 2020
Journal Name
Bulletin Of The Iraq Natural History Museum (p-issn: 1017-8678 , E-issn: 2311-9799)
COMPARATIVE STUDY OF SEVERAL MORPHOLOGICAL AND REPRODUCTIONAL ASPECTS FOR SOME SPECIES OF THE BELLEVALIA LAPEYROUSE, 1808 AND ORNITHOGALUM LINNAEUS, 1753 (ASPARAGALES, ASPARAGACEAE) IN CENTRAL AND NORTH OF IRAQ
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This study aims to study some morphological and reproductional characteristics in eleven species of two genera belonging to the family of Asparagaceae, which are Bellevalia Lapeyrouse, 1808 and Ornithogalum Linnaeus, 1753 and the species are: Bellevalia chrisii Yildirim and Sahin, 2014; Bellevalia flexuosa Boissier, 1854; Bellevalia kurdistanica Feinbrun, 1940; Bellevalia longipes Post, 1895; Bellevalia macrobotrys Boissier, 1853; Bellevalia paradoxa Boissier, 1882; Bellevalia parva Wendelbo, 1973; Bellevalia saviczii Woronow, 1927; Ornithogalum brachystachys C. Koch, 1849; Ornithogalum neurostegium Boissier, 1882 and Ornithogalum pyrenaicum Linnaeus, 1753. These species were identified and compared with each other; the results showed th

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