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The efficacy of polyether‐ether‐ketone wire as a retainer following orthodontic treatment
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Abstract<sec><title>Objectives

To investigate the efficacy of polyether‐ether‐ketone (PEEK) wire as a fixed orthodontic retainer, by comparing its performance to other retainer wires and optimizing its adhesion to composite bonding materials.

Materials and methods

Retainer wires of 15 mm segments were used, PEEK wires were prepared in cylindrical form with 0.8 mm diameter, and had two surface treatments namely air‐abrasion and conditioning with adhesive system. Three different metallic retainer wires were used for comparison and three tests were performed; two tests measured debonding force and associated wire deflection from acrylic blocks and bovine teeth and one test for pull‐out force. To test debonding force, a vertically directed compressive force was applied to the retainer wires bonded to the acrylic blocks and bovine teeth, while for pull‐out test; a vertically directed tensile force detached the retainer wire.

Results

In both debonding tests, PEEK wires (regardless the surface treatment) had non‐significant difference when compared to each other, or to the other metallic wires, except the dead‐soft coaxial wire group. The dead‐soft coaxial wire group had significant difference when compared to other groups regarding both the force magnitude and maximum deflection, the only exception was the debonding force of the flat braided retainer wires bonded to bovine teeth. In pull‐out test PEEK wires conditioned with adhesive system and the air‐abraded recorded the second and third highest readings respectively.

Conclusions

Within the limitations of this study, the 0.8 mm round PEEK wires have comparable performance—in terms of debonding and pull out forces—to conventional retainers when bonded with 4 mm composite bonding spots; using air‐abrasion for 10 s at 3.5 MPa provided sufficient adhesion of the composite to the wire, and conditioning with adhesive system may provide no further clinical benefit.

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Publication Date
Mon Sep 16 2019
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Peristaltic Flow of the Bingham Plastic Fluid in a Curved Channel
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    In this paper, we study the peristaltic transport of incompressible Bingham plastic fluid in a curved channel. The formulation of the problem is presented through, the regular perturbation technique for small values of  is used to find the final expression of stream function. The numerical solution of pressure rise per wave length is obtained through numerical integration because its analytical solution is impossible. Also the trapping phenomenon is analyzed. The effect of the variation of the physical parameters of the problem are discussed and illustrated graphically.

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Publication Date
Tue Aug 20 2024
Journal Name
مجلة جامعة ذي قار لعلوم التربية البدنية
A historical approach to the games of futsal and blind football
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Futsal and blind football are group games of a competitive nature due to their excitement, excitement, fun, and aesthetic goals with charming artistic touches. This explains the public's passion for these two games, whether healthy people or blind people play them, to expand their vision and knowledge. About these two games, a historical approach is presented about their origins, development, and how they became globally recognized competitive sports with unified rules and world championships at various levels. Studying the origin and global spread of both futsal and blind football and identifying the most prominent developments in the rules and tools for futsal and blind football. The most important findings were that both futsal and footb

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Publication Date
Mon Sep 25 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Quality Factor Effects on The Dynamical Behavior of A Ceramic Material
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Kaolin ceramic compacts sintered at various temperatures are investigated to correlate their microstructure with their acoustic parameters.  Pulse  velocity  ,  attenuation  coefficient,  and  quality factor values are ducts from ultrasonic attenuation measurements, moreover, the dynamical mechanics parameters( Young and shear modules) exhibited an explicit relationship with the acoustic quality factor.inturn  are  related  to  the  microstructure  which  is  heavily affected by the sintering mechanism.

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Publication Date
Fri Jul 01 2022
Journal Name
Journal Of Engineering
A Review of the Asphalt Mixtures Containing Recycled Solid Waste Materials
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Landfill and incineration are the most common and widely used methods to dispose of solid wastes; both of these techniques are considered the main sources of pollution in the world due to the harmful toxic emissions that are considered an environmental problem. Because of the large areas used by landfills, they are not always considered an economical method. With the increase in the production of solid materials, solid wastes increase the pressure on incinerators and landfills, making the environmental pollution hazard more serious. Instead, these waste materials can be used in some other applications. One of the most important of these applications is asphalt pavements, which are the most used types of pavements in the

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Publication Date
Sat Feb 01 2014
Journal Name
Journal Of Economics And Administrative Sciences
A comparison of the Semiparametric Estimators model smoothing methods different using
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In this paper, we made comparison among different parametric ,nonparametric and semiparametric estimators for partial linear regression model users parametric represented by ols and nonparametric methods represented by cubic smoothing spline estimator and Nadaraya-Watson estimator, we study three nonparametric regression models and samples sizes  n=40,60,100,variances used σ2=0.5,1,1.5 the results  for the first model show that N.W estimator for partial linear regression model(PLM) is the best followed the cubic smoothing spline estimator for (PLM),and the results of the second and the third model show that the best estimator is C.S.S.followed by N.W estimator for (PLM) ,the

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Publication Date
Fri Feb 10 2023
Journal Name
Journal Of Applied Mathematics
The Dynamics of a Delayed Ecoepidemiological Model with Nonlinear Incidence Rate
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In this paper, the general framework for calculating the stability of equilibria, Hopf bifurcation of a delayed prey-predator system with an SI type of disease in the prey population, is investigated. The impact of the incubation period delay on disease transmission utilizing a nonlinear incidence rate was taken into account. For the purpose of explaining the predation process, a modified Holling type II functional response was used. First, the existence, uniform boundedness, and positivity of the solutions of the considered model system, along with the behavior of equilibria and the existence of Hopf bifurcation, are studied. The critical values of the delay parameter for which stability switches and the nature of the Hopf bifurcat

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Publication Date
Thu Apr 04 2024
Journal Name
Chemchemtech
ANALYTICAL TECHNIQUES IN PHARMACEUTICAL POLLUTION OF THE WORLD’S RIVERS; A REVIEW
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Recent reports of new pollution issues brought on by the presence of medications in the aquatic environment have sparked a great deal of interest in studies aiming at analyzing and mitigating the associated environmental risks, as well as the extent of this contamination. The main sources of pharmaceutical contaminants in natural lakes and rivers include clinic sewage, pharmaceutical production wastewater, and sewage from residences that have been contaminated by drug users' excretions. In evaluating the health of rivers, pharmaceutical pollutants have been identified as one of the emerging pollutants. The previous studies showed that the contaminants in pharmaceuticals that are widely used are non-steroidal anti-inflammatory drugs, ant

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Scopus
Publication Date
Mon Jun 17 2019
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
A Study on the Algicidal effects of Iraqi Indigenous plant extracts.
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The Ethanolic extracts of different Iraqi indigenous plants which belong to different families showed algicidal activity against Anabaena, Nostoc and Myxosarcina species. Peganum harmala extract was the most potent in controlling the growth of tested Cyanobacterial species

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Publication Date
Sat Feb 27 2021
Journal Name
Iraqi Journal Of Science
Statistical Fluctuations of Energy Spectra in the Isobar A = 68 Nuclei
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Statistical fluctuations of nuclear energy spectra for the isobar A = 68 were examined by means of the random matrix theory together with the nuclear shell model. The isobar A = 68 nuclei are suggested to consist of an inert core of 56Ni with 12 nucleons in f5p-space (2p3/2, 1f5/2 and 2p1/2 orbitals). The nuclear excitation energies, required by this work, were obtained through performing f5p-shell model calculations using the isospin formalism f5pvh interaction with realistic single particle energies. All calculations of the present study were conducted using the OXBASH code. The calculated level densities were found to have a Gaussian shape. The distributions of level spacing P(s) an

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Publication Date
Tue Jun 30 2015
Journal Name
College Of Islamic Sciences
The formula is effective in Surat Nisa: (A study of gramophone)
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The formula is effective in Surat Nisa
(A study of gramophone)

in the name of o Allah the Merciful
Praise be to Allah, Lord of the Worlds, and prayers and peace be upon the Seal of the Prophets and Messengers. The envoy is a mercy to the worlds Muhammad Sadiq Al - Amin and to the pure and good companions of the Tayyibites.
The formula of the morphological formulas, which have diverged from other meanings, whether lexicon or contextual and what this formula contains many meanings (effective source) and (effective in the sense of effective) and (effective sense reactor) and (effective sense) and ( (F) in the sense of a similar character) and ((the name of the) (collect). This was dealt with in the formula in Surat al-Nisaa

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