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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
Fri Apr 21 2023
Journal Name
Technologies And Materials For Renewable Energy, Environment And Sustainability: Tmrees22fr
Effect of Ag doping on optical constant and hall effect measurements of SnS thin films
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In this report Silver doped Tin Sulfide (SnS) thin films with ratio of (0.03) were prepared using thermal evaporation with a vacuum of 4*10-6 mbar on glass with (400) nm thickness and the sample annealing with ( 573K ). The optical constants for the wavelengths in the range (300-900) nm and Hall effect for (SnS and SnS:3% Ag) films are investigated and calculated before and after annealing at 573 K. Transition metal doped SnS thin films the regular absorption 70% in the visible region, the doping level intensification the optical band gap values from 1.5- 2 eV. Silver doped tin sulfide (SnS) its direct optical band gap. Hall Effect results of (SnS and SnS:3% Ag) films show all films were (p-type) electrical conductivity with resistivity of

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Publication Date
Sun Sep 01 2013
Journal Name
Baghdad Science Journal
Preparation, characterization and study of biological activity and laser effect on the new Cu(II) complexes containing mixed benziloxime and furfuraldehydeazine ligands
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Abstract: New copper(II) complexes with mixed ligand benziloxime (BOxH) and furfural-dehydeazine (FA) using classical (with and without solvent) and microwave heating methods have been prepared. The resulting complexes have been characterized using physico-chemical techniques. The study suggested that the ligands formed neutral complexes had general formulas [Cu(FA)(BOXH)(Ac)2] and [Cu(FA)(BOX)(OH)] in neutral (or acidic) and basic medium, respectively. Accordingly, hexa-coordinated mono-nuclear complexes have been investigated by this study and having distorted octahedral geometry. The effect of laser have been studied on solid ligands and solid complexes, no effect have been observed on most compounds through the results of melting poin

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Publication Date
Mon Jul 31 2017
Journal Name
Journal Of Engineering
Experimental and Numerical Investigation of Hyper Composite Plate Structure Under Thermal and Mechanical Loadings
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Publication Date
Tue Oct 02 2018
Journal Name
Iraqi Journal Of Physics
Preparation of unsaturated polyester/nano ceramic composite and study electric, thermal and mechanical properties
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The composites were manufactured and study the effect of addition of filler (nanoparticles SiO2 treated with silane) at different weight ratios (1, 2, 3, 4 and 5) %, on electrical, mechanical and thermal properties. Materials were mixed with each other using an ultrasound, and then pour the mixture into the molds to suit all measurements. The electrical characteristics were studied within a range of frequencies (50-1M) Hz at room temperature, where the best results were shown at the fill ratio (1%), and thermal properties at (X=3 %), the mechanical properties at the filler ratio (2%).

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Publication Date
Sun Jun 01 2014
Journal Name
Baghdad Science Journal
Study of Fatigue and Bending Properties For Epoxy / Kevlar - Glass Fibers and Hybrid Composite
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In this research a study of the effect of quality, sequential and directional layers for three types of fibers are:(Kevlar fibers-49 woven roving and E- glass fiber woven roving and random) on the fatigue property using epoxy as matrix. The test specimens were prepared by hand lay-up method the epoxy resin used as a matrix type (Quick mast 105) in prepared material composit . Sinusoidal wave which is formed of variable stress amplitudes at 15 Hz cycles was employed in the fatigue test ( 10 mm )and (15mm) value 0f deflection arrival to numbers of cycle failure limit, by rotary bending method by ( S-N) curves this curves has been determined ( life , limit and fa

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Publication Date
Wed Jan 10 2024
Journal Name
The American Journal Of Interdisciplinary Innovation And
SUBJECT REVIEW PHASES OF SUGAR METABOLISM AND THE EFFECT OF HORMONES
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Publication Date
Sun Sep 30 2001
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Study the Characteristic Performance of Trickling Filter for Pharmaceutical Waste Treatment
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Publication Date
Sun Aug 30 2020
Journal Name
Journal Of Economics And Administrative Sciences
The impact of transcendental leadership in enhancing university performance (Field research)
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Current research aims to analyze the relationship and impact of the explanatory variable transcendental leadership, which includes dimensions (values ​​and attitudes, behavior, spirituality, vision and hope/faith) in the responsive variable university performance dimensions (relationships and resources available, human capital development, scientific research, community service). Field research for the leaders of a number of colleges of the University of Baghdad of the deans of the colleges of research and assistants of deans and heads of departments, the main research problem was the important question (what is the role of transcendent leadership in promotin

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Publication Date
Sun Jul 17 2016
Journal Name
2016 Asabe International Meeting
THE PERFORMANCE OF FARM TRACTORS AS REPORTED BY CAN-BUS MESSAGES
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Publication Date
Wed Aug 11 2021
Journal Name
مجلة القانون الدستوري والعلوم الادارية
  The role of positive psychological capital in activating sustainable performance standards
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اعداد : أسرار عبد الزهراء علي - علاء الدين - ب. جواد  حسن عودة عبد الله  - جامعة بغداد جامعة بغداد كلية البصرة للعلوم والتكنولوجيا - كلية الإدارة والاقتصاد. كلية الإدارة والاقتصاد المركز الديمقراطي العربي –   مجلة القانون الدستوري والعلوم الإدارية : العدد التاسع شباط – فبراير 2021 المجلد 3 ،

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