Preferred Language
Articles
/
nRcsno0BVTCNdQwCxBbn
The effect of composite bonding spot size and location on the performance of poly-ether-ether-ketone (PEEK) retainer wires
...Show More Authors

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

Scopus Crossref
Publication Date
Thu Mar 30 2023
Journal Name
College Of Islamic Sciences
Title: Arabic Manuscript, Concepts and Terms and Their Impact on Determining Its Historical beginnings and extension of its existence.
...Show More Authors

Title: Arabic Manuscript, Concepts and Terms and Their Impact on Determining Its Historical beginnings and extension of its existence.

Researcher: Dr. Atallah Madb Hammadi Zubaie.

Bn the name of Allah Most Merciful

The interest in manuscripts and rules  of their investigation and dissemination appeared soon, and the speech in editing terms and concepts appeared in sooner time.  When looking at the classified books  in the Arab manuscripts , we find the books of the first generation  did not allude definition for this term  , but rather  focused on  the importance of manuscripts and their  existence locations, indexing, care, and verification rules. The  reason for this is that the science of Arabic manuscrip

... Show More
View Publication Preview PDF
Publication Date
Fri Jun 01 2012
Journal Name
Journal Of Economics And Administrative Sciences
Effect Of Comprehensive Income In Market Value Of Company Importance Of Comprehensive Income In Market Value Of
...Show More Authors

The study aims (objective ) to clarify the concept of comprehensive income and its usefulness for users, as the study aims to clarify the relationship between the concept of comprehensive income and market value of the company where the measurement of comprehensive income after accounting for net income and by measuring the unrealized gains or losses in the value of securities available for sale, and measurement the unrealized gains or losses on futures contracts, which are financial derivatives, and measurement the unrealized gains or losses from the settlement of foreign currency translation (conversions), and measurement the impact on the market value of companies and of the present study to rise or fall of return on the stock

... Show More
View Publication Preview PDF
Crossref
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
...Show More Authors

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

... Show More
View Publication Preview PDF
Crossref
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
...Show More Authors

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

... Show More
View Publication Preview PDF
Scopus Crossref
Publication Date
Tue Jan 01 2019
Journal Name
Indian Journal Of Public Health Research & Development
A 4-Day Plaque-Regrowth Anti-Plaque Effect of a Combination of Green Tea and Salvadora Persica L.: A Randomized Controlled Crossover Clinical Trial
...Show More Authors

View Publication
Scopus Crossref
Publication Date
Thu Aug 01 2024
Journal Name
Misan Journal For Physical Education Sciences
A comparative study of the reasons for the reluctance of female physical education teachers in “Baqubah” to participate in refereeing sports competitions according to the variable of years of service
...Show More Authors

When searching for an answer to the following question: What are the reasons for the reluctance of female physical education teachers in secondary schools to referee sports competitions according to the variable of years of service? It was found that the research aimed to reveal the differences between the opinions of the research sample of physical education teachers in secondary schools (girls) about refereeing sports competitions according to the variable of years of service. To achieve the research goal, it is assumed that there are significant differences between the average opinions of the research sample of female teachers and their reluctance and the reasons for the differences in the practice of refereeing sports competitions accor

... Show More
View Publication Preview PDF
Publication Date
Mon Nov 01 2021
Journal Name
Iop Conference Series: Earth And Environmental Science
Study of Seed Soaking and Foliar Application of Ascorbic Acid, Citric Acid and Humic Acid on Growth, Yield and Active Components In Maize
...Show More Authors

Foliar application and seed soaking has been used as a means of supplying supplemental doses of nutrients, plant hormones, stimulants, and organic components. the effects of these applications have included yield increases, and improved drought tolerance, and enhanced crop quality, so A field experiment was carried out during spring seasons in 2019 and 2020 for styding Seed soaking and Foliar Application of Ascorbic acid, Citric acid and Humic acid on Growth, Yield and Active Components IN Maize. Randomized complete block design in split plots arrangement was used with three replicates. Main-plots were for seeds soaking with ascorbic, citric (100 mg l-1) frequently and humic at (1 ml l-1). Sub-plots were for vegetative parts nutrition with

... Show More
View Publication Preview PDF
Scopus (6)
Crossref (3)
Scopus Crossref
Publication Date
Mon Oct 04 2923
Journal Name
Journal Of Sustainable Studies
Enantiosemy in a Comparative Aspect: On the Material of Modern Russian and Arabic Languages Энантиосемия в сравнительном аспекте: На материале современного русского и арабского языков التضاد - دراسة مقارنة : اللغات الروسية والعربية الحذيثة أنمورجا
...Show More Authors

This work is devoted to a comparative study of the phenomenon of enantiosemy in Russian and Arabic.Everyone knows the term antonyms - words of the same part of speech, opposite in meaning, such as: Day and night, white and black, truth and lies. But in Russian, Arabic and other languages there is an interesting phenomenon, which consists in the fact that one word has two opposite meanings. Such a phenomenon in linguistics is called enantiosemy (from the Greek words enantios - "opposite" and sema - "sign")

Publication Date
Tue Feb 19 2019
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Role of the Opportunity Cost in the Overall Economic Development: Applied Study in The General Company for Leather Industries
...Show More Authors

This research set to indicate the role of the opportunity cost in the overall economic development (human and social development) by selecting the most appropriate alternative for the growth of the country in exchange for sacrificing profit limits to achieve this growth and development of the country, especially in the present circumstances of the country and after studying the reality of the economic case for him, as the problem lies with don't selecting the best alternative that enhances the gross domestic product, which extends to promote overall economic development and revive the industrial and agricultural sectors, productivity is more like Impotent, versus sacrifice alternative consumption may bring more financially lucrative than

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Mar 07 2010
Journal Name
Baghdad Science Journal
Improvement the bearing capacity of the soil which is supporting the shallow foundation by using bored short micro-piles
...Show More Authors

In this paper , concrete micro-piles were used to improve the bearing capacity of the soil which is supporting the shallow foundation by using groups of (4; 6 and 9)bored short micro-piles which have, (D=0.125m and D=0.1m), and length to diameter ratio (L/D) equal to (6; 10 and 12) respectively. To calculate the bearing capacity of the micro-piles,(Tomlinson) and (Lamda) methods were used; also the soil properties were taken from Al-Muthana airport,(Al-Qyssi,2001) [1]. The results show that; increasing the number of piles and/ or the diameters and lengths; and the interaction between the bearing capacity of the shallow foundation with the bearing capacity of the pile group which leads to increasing the strength against the external loads

... Show More
View Publication Preview PDF
Crossref