Background: evaluate the effects of three different intracoronal bleaching agents on the shear bond strengths (SBS) and failure site of stainless steel and monocrystalline (sapphire) orthodontic brackets bonded to endodontically treated teeth using light cured orthodontic adhesive in vitro. Materials and methods: Eighty extracted sound human upper first premolars were selected, endondontically treated and randomly divided equally (according to the type of the brackets used) into two main groups (n = 40 per group). Each main group were subdivided (according to the bleaching agent used) into four subgroups 10 teeth each; as following : control (un bleached) group, hydrogen peroxide group (Hp) 35%, carbamide peroxide group (CP) 37% group and sodium perborate (SP) group . The bleaching process was applied three times (4 days intervals) sequentially and the bleached teeth were stored in artificial saliva four weeks before bonding. Orthodontic brackets were bonded with a light cure composite resin and cured with LED light. After passing 24 hours of bonding procedure, the brackets were debonded by a Tinius-Olsen universal testing machine, to measure the shear bond strength. After debonding, each bracket base and the corresponding tooth surface were examined using a stereomicroscope and their Adhesive Remnant Index (ARI) was recorded. Results: The ANOVA test showed that the SBS of stainless brackets was significantly reduced by intracorornal bleaching agents. Furthermore, LSD showed no significant difference in SBS between the three types of bleaching agents used in stainless steel group. Whilst for sapphire group, the results The ANOVA test showed no significant difference in SBS between the bleached groups and the control group. Chi-square comparison no significant difference in failure site between bleached and control groups in both brackets types used. Conclusion: The effect of intracoronal bleaching on SBS was reduced SBS of stainless steel and not for sapphire. However, the intracoronal bleaching had no effect on the failure site of orthodontic brackets used.
Objective(s): The present study describes the quality of life (QOL) among adolescents with age of (12-22) year old and identifies factors that may be associated with it. Methodology: A cross-sectional design is carried throughout to evaluate adolescents' quality of life in Hilla City for the period of September 2nd 2016 to November 6th 2016. The present study is conducted in different settings that include schools and colleges in Hilla City. A non-probability "purposive" sample of (144) participant is selected and comprised of (50%) males and (50%) females. An instrument is constructed for the intent of the st
The present work describes the development of code for trim and longitudinal stability analysis of a helicopter in forward flight. In general, particular use of these codes can be made for parametric investigation of the effects of the external and internal systems integrated to UH-60 helicopters. A forward flight longitudinal dynamic stability code is also developed in the work to solve the longitudinal part of the whole coupled matrix of equations of motion of a helicopter in forward flight. The coupling is eliminated by linearization. The trim analysis results are used as inputs to the dynamic stability code. The forward flight stability code is applied to UH-60 helicopter.
Objective: To determine the prevalence of bullying among primary schools’ children with some associated factors, and resultant effects. Methodology: This cross-sectional study with analytic elements was carried out from February through April 2022. It included a sample of 410 students from six governmental primary schools from both sides of Baghdad city. A self-constructed questionnaire was used. It comprised the following parts: Part (1): socio-demographic data, Part (2): questions that review the students’ exposure to bullying, and Part (3) entails the effects of bullying on those children. Results: The total sample was composed of 410 students; their mean age was 9.51±1.94 years. The prevalence of bullying was 56.34%. Studen
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God has honored the man with life and decent living and warned against attacking anything that violates his sanctity without a legitimate right. Our Islamic Shari'ah has the rights to preserve the right of a Muslim in the event of any harm.
Abstract: The research covered five chapters: So, the first chapter definition of the research is from the introduction to the research and its importance, as the importance of the research lies in an expression of the reality of e-learning as it is one of the new patterns of the educational process and its role in enhancing communication and interconnectedness between the learners from the students ’point of view Physical Education and Sports Sciences for Girls, University of Baghdad, as for the problem The research was, and through the researcher’s acquaintance with many previous studies, references and sources, and being a student at the College of Physical Education and Sports Sciences - University of
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In this work, wide band range photo detector operating in UV, Visible and IR was fabricated using carbon nanotubes (MWCNTs, SWCNTs) decorated with silver nanoparticles (Ag NPs). Silicon was used as a substrate to deposited CNTs/Ag NPs by the drop casting technique. Polyamide nylon polymer was used to coat CNTs/Ag NPs to enhance the photo-response of the detector. The electro-exploding wire technology was used to synthesize Ag NPs. Good dispersion of silver NPs achieved by a simple chemistry process on the surface of CNTs. The optical, structure and electrical characteristic of CNTs decorated with Ag NPs were characterized by X-Ray diffraction and Field Emission Scanning Electron Microscopy. X-ray diffra
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Has been studied both processes Almetzaz and extortion of a substance Alklanda Maysan different amounts of Alcaúlan Guy 70% alcohol solution using the method when the wavelength
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