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
Sun Feb 10 2019
Journal Name
Journal Of The College Of Education For Women
The beginning of culturally renaissance in Arab Gulf region in the first half from 20th century
...Show More Authors

The present paper deal with the issue of the beginning of the culturally
renaissance in emirates of Arab Gulf from 1914-1945 between tow world war
has been attracting the attention of academic about the developments in many
fields in the Arab Gulf at this time.
The paper is divided into five sections. First section, deals with the
geographic importance for the Arab Gulf region. Second section, the economic
situations in the region before and after oil. The third section, talk for social
situations, like population, tribe and tribes in society, and immigration. The
fourth section, deals with the factors of rise the culture and political in the Arab
Gulf before discovery of oil period. The five section, the cultu

... Show More
View Publication Preview PDF
Publication Date
Mon Feb 04 2019
Journal Name
Iraqi Journal Of Physics
Risks assessment for the retrieval of radioactive waste from the old Russian cemetery Al -Tuwaitha site
...Show More Authors

In this work the radioactive wastes in the Old Russian
Cemetery Al -Tuwaitha site were classified according to risks for
workers who are involved in the retrieval process. The exposure
assessment results expressed as estimates of radionuclide intakes by
inhalation and ingestion, exposure rates and duration for external
exposure pathways, and committed effective dose equivalents to
individuals from all relevant radionuclides and pathways. Results
showed the presence of natural radionuclides Ra-226, Th-234 and K-
40, as well as the produced radionuclide Cs-137 and Eu-152 in the
cemetery wells. The absorbed doses from the waste were classified to
two categories; exempt waste and low level waste according to

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Feb 04 2019
Journal Name
Journal Of The College Of Education For Women
The Unque Necklace ; ( Al – Iqd Al – Farid) ; A Reading in the Light of Speech Acts Theory
...Show More Authors

Summed up the idea of this research in an attempt to find the establishment of the knowledge convergence to show the features of verbal acts that occurred a prime location in the lesson deliberative theory book unique contract ( IbnAbdRabbaAndalusian ) to prove that Arabic was the old literary studies included many of the features of this theory in both theoretical and practical

View Publication Preview PDF
Publication Date
Fri Mar 01 2019
Journal Name
Iraqi Journal Of Physics
The dispersion in spherical statistical optical potential (SOM) from the interaction of fast neutrons with197Au nucle
...Show More Authors

A statistical optical potential has been used to analyze and
evaluate the neutron interaction with heavy nuclei 197Au at the
neutron energy range (1-20 MeV). Empirical formulae of the optical
potentials parameters are predicted by using ABAREX Code with
minimize accuracy compared with experimental bench work data.
The total elastic, absorption, shape elastic and total compound crosssections are calculated for different target nuclei and different
incident neutron energies to predict the appropriate optical
parameters that suit the present interaction. Also the dispersion
relation linking between real and imaginary potential is analyzed
with more accuracy. The results indicate the behavior of the
dispersion c

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Mar 01 2020
Journal Name
Astrophysics And Space Science
The compound stream event of March 20-25, 2011 as measured by the STEREO B spacecraft
...Show More Authors
Abstract<p>The interaction of interplanetary coronal mass ejections (ICME) with each other and with co-rotating interaction regions (CIR) changes their configuration, dynamics, magnetic field and plasma characteristics and can make space weather forecasting difficult. During the period of March 20–25, 2011, the Solar Terrestrial Relation Observatory (<italic>STEREO</italic> B) encountered a compound stream containing several interacting structures. Our analysis suggests that the stream consists of two ICMEs followed by an embedded ICME/CIR. The sudden appearance of the third ICME within the fast wind side of the CIR causes the proton temperature(<inline-formula><alternatives><tex-math></tex-math></alternatives></inline-formula></p> ... Show More
View Publication
Scopus Clarivate Crossref
Publication Date
Thu Jan 01 2015
Journal Name
Finite Difference Methods,theory And Applications
Determination of the Time-Dependent Thermal Conductivity in the Heat Equation with Spacewise Dependent Heat Capacity
...Show More Authors

View Publication
Scopus (3)
Crossref (1)
Scopus Clarivate Crossref
Publication Date
Fri Dec 30 2022
Journal Name
Journal Of The College Of Education For Women
The Existential Psychological Crisis Among Battered Women to Non-Battered Women in the Republic of Yemen
...Show More Authors

The research deals with a very important issue that affects women, an important segment of the society. This is because women are the basis of the family and the pillar of the society. Thus, the aim of the research is to examine the level and dimensions of the emotional and existential psychological crisis at the sample of the study. It further aims to investigate the statistical significant difference at the level of (0.05) regarding the feeling of the existential psychological crisis among battered and non-battered women. To reveal the objectives of the study, the researcher applied the existential psychological crisis scale to a sample of (72) women, divided into two groups: (35) battered women, who have been chosen purposefully. Thos

... Show More
View Publication Preview PDF
Crossref
Publication Date
Fri Jun 30 2023
Journal Name
Journal Of The College Of Education For Women
The Request Construction in the Diwan of (Al-Shamakh bin Dirar Al-Dhubyani) A Rhetorical Study
...Show More Authors

This study examined the imperative construction: the command, the interrogative, the prohibition, the call, and the wish. In the Diwan of Al-Shamakh bin Dirar; where the poetic verses were monitored in each of the topics of the student's creation, and the rhetorical meanings that he came out with. What is new in this study is that it is the first to study the demanded composition in the poetry of a glorious poet, Al-Shammakh bin Dirar Al-Dhubyani. As his poetry did not receive such a study, it sought to employ what was written by rhetoric scholars, in an attempt to explore the demanded composition in the poetry of Al-Shamakh. The study adopted the descriptive analytical approach, which is based on counting the number of times the poet us

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Aug 01 2017
Journal Name
Journal Of Economics And Administrative Sciences
Effective administrative leadership in the implementation of public policies: Analytical look at the Baghdad Provincial Council
...Show More Authors

Abstract

      The current research aims to find out the role of administrative leadership in the implementation of public policies and their effectiveness and their ability to do so, As well as analysis and testing of influence and correlations between research variables, The researcher has the descriptive and analytical approach, And several tools used to gather information consisted of personal interviews and field visits, While distributed questionnaire tool that consists of (35) items on a sample consisting of (147) individuals formed of staff of the Baghdad Provincial Council.

The research was based on a set of assum

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Tue Jun 30 2015
Journal Name
College Of Islamic Sciences
Imam al - Karji replies to some Islamic groups In his book the jokes of the Koran
...Show More Authors

Imam al - Karji replies to some Islamic groups
In his book the jokes of the Koran

View Publication Preview PDF