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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
Sat Jul 01 2017
Journal Name
Journal Of Construction Engineering And Management
Identification, Quantification, and Classification of Potential Safety Risk for Sustainable Construction in the United States
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Publication Date
Thu Nov 01 2018
Journal Name
Al-kindy College Medical Journal
The Efficacy and Safety Of Using Hydrochlorothiazide As Adjuvant Therapy In Pediatric Urinary Tract Infections
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Background: Acute urinary tract infection is a common bacterial infection causing illness in infants and children. At age of seven, 8% of girls and 2% of boys will have at least one episode. Although drinking water and using home remedies are known to help to flush away bacteria and keeps them from sticking to the bladder wall, researches to test the efficacy and safety of hydrochlorothiazide's diuretic effect as adjuvant to the antibiotics in pediatric age groups are lacking, and so this research was to address this subject.

Objectives: To assess the effectiveness   and  the safety of hydrochlorothiazide as adjuvant therapy to the antibiotics in treating acute urinary tract infect

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Publication Date
Sun Apr 30 2023
Journal Name
Iraqi Journal Of Science
PETROLOGY OF THE INJANA FORMATION (UPPER MIOCENE)AT ZAWITA, AMADIYA AND ZAKHO AREA, NORTHERN IRAQ
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This study deals with the petrology of Injana Formation (Upper Miocene) at
Zawita, Amadia and Zakho areas. The sandstone of Injana Formation is of two
typesnamely, litharenite and feldspathiclitharenite. The rock fragments of Injana
Formation are mostly sedimentary and hence the sandstones are classified as
sedarenite and more specifically chertarenite owing to the predominance of chert
rock fragments. The sandstone is mineralogicallysubmature rangingfrom
mechanically and chemically stable tounstable. The petrographic studies reveal
nearness of source area with arid to semi-arid climate. The source rocks are
sedimentary, low- to medium-grade metamorphic and basic volcanic rocks. They are
mostly supplied from th

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Publication Date
Tue Jan 08 2019
Journal Name
Iraqi Journal Of Physics
The structure and optical properties of organic semiconductor bulk hetrojunction blend (NiPcTs/Alq3) thin films
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The effect of heat treatment on the optical properties of the bulk heterojunction blend nickel (II) phthalocyanine tetrasulfonic acid tetrasodium salt and Tris (8-hydroxyquinolinato) Aluminum (NiPcTs/Alq3) thin films which prepared by spin coating was described in this study. The films coated on a glass substrate with speed of 1500 rpm for 1.5 min and treated with different annealing temperature (373, 423 and 473) K. The samples characterized using UV-Vis, X ray diffraction and Fourier transform Infrared (FTIR) spectra, XRD patterns indicated the presence of amorphous and polycrystalline blend (NiPcTs/Alq3). The results of UV visible shows that the band gap increase with increasing the annealing temperature up to 373 K and decreases with

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Crossref
Publication Date
Wed Feb 01 2023
Journal Name
Journal Of Engineering
Checking the Accuracy of Selected Formulae for both Clear Water and Live Bed Bridge Scour
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Due to severe scouring, many bridges failed worldwide. Therefore, the safety of the existing bridge (after contrition) mainly depends on the continuous monitoring of local scour at the substructure. However, the bridge's safety before construction mainly depends on the consideration of local scour estimation at the bridge substructure. Estimating the local scour at the bridge piers is usually done using the available formulae. Almost all the formulae used in estimating local scour at the bridge piers were derived from laboratory data. It is essential to test the performance of proposed local scour formulae using field data. In this study, the performance of selected bridge scours estimation formulae was validated and sta

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Publication Date
Wed Feb 22 2023
Journal Name
Iraqi Journal Of Science
Facies, Depositional Environment and Cyclicity of the Fatha Formation in East Baghdad Oil Field, Iraq.
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This study deals with establishing the depositional environment of the Fatha Formation through facies analysis. It also deals with dividing the formation into units based on the rhythmic nature. Data from selected shallow wells near Hit area and deep wells at East Baghdad Oil field are used. Five major lithofacies are recognized in this study, namely, greenish grey marl, limestone, gypsum (and/or anhydrite), halite and reddish brown mudstone (with occasional sandstone).The limestone lithofacies is divided into three microfacies: Gastropods bioclastic wackestone microfacies, Gastropods peloidal bioclastic packstone, and Foraminiferal packstone microfacies.The lithofacies of the Fatha are nested in a rhythmic pattern or what is known as sh

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Publication Date
Thu Sep 01 2011
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The Role of higher Education Institutes in restricting Administrative and Financial Corruption: An Analytic Reading
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Corruption, in all its categories and forms, is regarded as the nowadays virus which has greatly spread in most institutes and society, a matter that cause a great waste of resources.

      According to the reports of international transparency Institute, Iraq is regarded as one of the greatest countries in corruption.

      Regardless of the reasons and forms of corruption, the retreat in work – values and ethics are the main reasons behind that.

      Being the main source of providing qualified staff "educators" for the working market, the high education institutes face great challenges in standing against corruption inside and outside

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Publication Date
Thu May 13 2004
Journal Name
The College Of Arts/ Al-mustansiriyya University
The Linguistic Aspect of Euphemism in Jane Austen's Novel Emma: Motivation and Formation
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APDBN Rashid, The College of Arts/ Al-Mustansiriyya University, 2004

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Publication Date
Wed Feb 08 2023
Journal Name
Iraqi Journal Of Science
Ecology and Geographical Distribution for Six Species of the Genus Echinops L.(compositae) in Iraq
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This study includes six species related to the genus Echinops L. (composite) grown in Iraq which are listed below: E.armatus Boiss. & Hausskn., E. bicolor Nabelek, E. cephalotes DC., E.haussknechtii Boiss., E. moulensis Rech., E. nitens Bornm., the geographical distribution and ecological preferences' were documented.
It has been also observed that this genus was distributed near waterfalls, vallies, road side, dry limestone, clay soil and hard rocky soil in Different heights. The most separated species was E.armatus and the least separated one was E.haussknechtii, the species was listed in diagram and distributed on a map.

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Publication Date
Sun Apr 30 2023
Journal Name
Iraqi Journal Of Science
Sequence Stratigraphy and Reservoir Characterization of the Upper Campanian-Maastrichtian Succession, Buzurgan Field, Southeastern Iraqi
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The Upper Campanian-Maastrichtian succession in Buzurgan oil field of Southeastern Iraq consists of Hartha and Shiranish formations. Three facies associations were distinguished in the studied succession. These include shallow open marine environment within the inner ramp, deep outer ramp and basinal environments. The Hartha Formation in the study area was deposited on a shallow carbonate platform with distally steepened ramp setting. The studied succession represents two 3rd order cycles. These cycles are asymmetrical and start with cycle A which is incomplete where the lower part of the Hartha Formation represents the deep outer ramp facies of the transgressive system tract.and the upper part of the Hartha Formation reflects deposition

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