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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 Mar 18 2019
Journal Name
Al-khwarizmi Engineering Journal
Effect of optimal shot peening time on fatigue life for aluminum alloy 6061-T651
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The compressive residual stresses generated by shot peening, is increased in a direct proportional way with shot peening time (SPT). For each metal, there is an optimum shot peening time (O.S.T) which gives the optimum fatigue life. This paper experimentally studied to optimize shot peening time of aluminium alloy 6061-T651 as well as using of and analysis of variance (ANOVA).

Two types of fatigue test specimens’ configuration were used, one without notch (smooth) and the other with a notch radius (1,25mm), each type was shot peened at different time. The (O.S.T) was experimentally estimated  to be 8 minutes reaching the surface stresses at maximum peak of -184.94 MPa.

A response surface methodology (RSM) is presen

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Publication Date
Wed Jul 17 2019
Journal Name
Aip Conference Proceedings
Annealing effect on characterization of nano crystalline SnSe thin films prepared by thermal evaporation
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Tin Selenide (SnSe) Nano crystalline thin films of thickness 400±20 nm were deposited on glass substrate by thermal evaporation technique at R.T under a vacuum of ∼ 2 × 10− 5 mbar to study the effect of annealing temperatures (as-deposited, 100, 150 and 200) °C on its structural, surface morphology and optical properties. The films structure was characterized using X-ray diffraction (XRD) which showed that all the films have polycrystalline in nature and orthorhombic structure, with the preferred orientation along the (111) plane. These films was synthesized of very fine crystallites size of (14.8-24.5) nm, the effect of annealing temperatures on the cell parameters, crystallite size and dislocation density were observed.

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Publication Date
Wed Dec 14 2011
Journal Name
Journal Of Kerbala University
Effect of prey type on some reproductive aspects in crustacean zooplankton Macrocyclops albidus (Copepoda:cyclopoida)
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The experiment was conducted to investigate the effect of prey type (Artemia nauplii, mosquito larvae and paramecium) on some reproductive aspects in crustacean zooplankton M. albidus which included reproductive period, post reproductive period, period spend to egg appearance and the period from appearance of egg to nauplii releasing. Results revealed that females fed on mosquito larvae had the highest mean of postreproductive period and lowest mean of the period spend to egg appearance, which differed significantly (P < 0.05) compared with the means of females who fed on Artemia nauplii and paramecium on the other hand the differences were not significant in reproductive period and the period from appearance of egg to nauplii releasing.

Publication Date
Wed Jun 30 2010
Journal Name
Al-kindy College Medical Journal
Effect of Very Early Atorvastatin Initiation for Acute Myocardial Infarction on Creatine Kinase release
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Background : It has been suggested that pretreatment with a statin agent prior to
myocardial infarction limits myocardial
creatine kinase release, and thus may act to
limit myocardial infarct size in humans.
Objective : To examine the effect of very
early statin initiation for acute myocardial
infarction (AMI), to the extent of
myonecrosis as manifested by peak serum
creatine kinase levels.
Methods : Patients with AMI admitted to AlKindy teaching hospital cardiac care unit
from 1st February 2007 to 28th February
2008, who fulfilled the inclusion criteria
cited in the present study, were randomly
assigned into two study groups. The statin
group patients have received a single oral
dose of 40 mg

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Publication Date
Fri Dec 14 2018
Journal Name
Iraqi National Journal Of Nursing Specialties
Effect of Electronic Games on Children Behaviors who Attending Teaching Hospitals in Baghdad City
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Objective(s): current study aims to find the effect of electronic games on children's behavior, and find the
relationship between child demographic data and the effect of electronic games on the child's behavior.
Methodology: A descriptive-analytic study was conducted for assessing the Effect of electronic games on
children's behaviors that attending to teaching hospitals in Baghdad city during the period of (October/ 20th
/2017 to March/1st /2018). A (50) purposive (non- probabilistic) sample from: Child Protection teaching
Hospital, Child Central Hospital in AL-Iskan. The sample is selected according to the criteria: Children who
visited the consulting unit of children in the hospitals in the first visit, children in

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Publication Date
Sat Nov 10 2018
Journal Name
Iraqi National Journal Of Nursing Specialties
Effect of Long Term Exposure to Sodium Nitrite on Gene Responsible for DNA Repair
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Objective: The aim of this study is to detect the effect of continuous exposure to Sodium Nitrite on 8-oxoguanine
DNA glycosylase (OGG1) gene which responsible on DNA repairs. DNA repair play a major role in maintaining
genomic stability when DNA exposure to damage. Genomic stability is very important for keeping body cells
healthy and to prevent many types of tumor development. Many genes are responsible for this job; one of them is
OGG1 gene.
Methodology: In current study two groups of mice were chronically exposed to sodium nitrite for six months and
eighteen months while third group was used as a control. Then sizes of OGG1 were estimated.
Results: The results exhibited in the unexposed (control) mice had two dif

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Publication Date
Sat Dec 01 2012
Journal Name
Journal Of Engineering
Effect Of Technology Based Learning As A Supplement To Traditional Technology On Student's Achievement
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This paper describes a practical study on the impact of learning's partners, Bluetooth Broadcasting system, interactive board, Real – time response system, notepad, free internet access, computer based examination, and interaction classroom, etc, had on undergraduate student performance, achievement and involving with lectures. The goal of this study is to test the hypothesis that the use of such learning techniques, tools, and strategies to improve student learning especially among the poorest performing students. Also, it gives some kind of practical comparison between the traditional way and interactive way of learning in terms of lectures time, number of tests, types of tests, student's scores, and student's involving with lectures

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Publication Date
Mon Sep 30 2024
Journal Name
Journal Of Obstetrics, Gynecology And Cancer Research
Effect of a Nutritional Education Program on Mother Knowledge Regarding Their Children Nutritional Status
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Publication Date
Tue Mar 30 2021
Journal Name
Journal Of Economics And Administrative Sciences
The Effect of Organizational Creativity in Enhancing Knowledge Management Processes: survey study for a sample of academic staff members at the Technical College of management / Baghdad)
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In many organizations, employees who have high mental skills are the main source of organizational creativity. When a firm does not put creativity as a goal, cannot stand solid against the competition. Nowadays, knowledge is the path to discover the innovation and creativity aspects, This can assist the firm to stand face to face with competition in the market. The importance of this research comes from detecting and knowing the relation between creativity and knowledge to know and detect the influence of organizational creativity on backing the management of knowledge and determine the final results. The problem of research is to trace the role of organizational creativity on knowledge management processes in order to enable the

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Publication Date
Thu Dec 28 2023
Journal Name
Journal Of Physical Education
The reality of the administrative values of sports activities in the Faculties of the University of Baghdad from the point of view of leaders and those related to the divisions and units of student's activities
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The research aimed to identify the level of reality of administrative values of sports activities in the Faculties of the university of Baghdad from the point of view of the leaders and those related to the divisions and units of student's activities and the case study method was adopted from the descriptive approach.