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Testing Different Properties of A Light-Cured Denture Base Material After Addition of Silicon Oxide Nanofiller (An in Vitro Study)
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ABSTRACT Background: Improving the properties of heat- cured and self-cured acrylic resin have been studied by many researchers. However, little studies concerned with visible light cured resin (VLCR) improved through addition of nanofiller are available. The purpose of this study was to evaluate some properties of (VLCR) after addition of SiO2 nanofiller. Materials and Methods: SiO2 nanofiller were added to (VLCR) tray material after being dissolved in tetrahydrofuran (THF) solvent. According to the pilot study 2% SiO2 nanofiller addition exhibited better properties than the other percentages (1%, 3%). The main study conducted involved (100) specimens divided into 5 groups according to the test included. (20) Specimens were selected for each test (10 samples for the control group and 10 samples for the experimental 2% SiO2 nanofiller group). The properties investigated were transverse strength, impact strength, surface hardness, surface roughness, water sorption and solubility. Scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) were used to assess nanofiller distribution and identification of elements. The data were subjected to descriptive statistical analysis and independent sample t-test. Results: The mean value of transverse strength of experimental group increased significantly, while the impact strength of experimental group decreased significantly when compared to control group. A significant increase in surface hardness was noticed in the experimental group, while non-significant increase in surface roughness was observed. The water sorption values were decreased significantly, while a non-significant decrease in water solubility was observed in the experimental group. Conclusion: Addition of SiO2 nanofiller to (VLCR), slightly improve the transverse strength and surface hardness, while water sorption and solubility slightly decreased. The impact strength was significantly deteriorated, while the surface roughness shows non-significant increment.

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Publication Date
Fri Jun 12 2020
Journal Name
Test Engineering & Management
Studying the Optical Properties of CdSe Quantum Dots Prepared by Colloidal Method with Different pH Values
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Publication Date
Sun Jun 12 2011
Journal Name
Baghdad Science Journal
The optical properties of Poly methyl methacrylate (PMMA) polymers doped by Potassium Iodide with different thickness
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Films of pure Poly (methyl methacrylate) (PMMA) doped by potassium iodide (KI) salt with percentages (1%) at different thickness prepared by casting method at room temperature. In order to study the effect of increasing thickness on optical properties, transmission and absorption spectra have been record for five different thicknesses(80,140,210,250,320)µm. The study has been extended to include the changes in the band gap energies, refractive index, extinction coefficient and absorption coefficient with thickness.

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Publication Date
Thu Jun 15 2017
Journal Name
مجلة العلوم الاجتماعية
Self-compassion among university students in light of some variables
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The study aimed to identify the self- compassion of the students as well as to identify the differences in the self- compassion according to the variables: sex - the academic specialization - Study level, the sample of the study of (200) students distributed equally by sex (male - female) Specialization (Scientific - Human) compassion. The results showed that there were no differences in the self- compassion according to the variables: gender, academic specialization, and Study level. In light of these results, the researcher Number of the recommendations and proposals

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Publication Date
Sat Oct 15 2005
Journal Name
Journal Of Palestine Ahliya University For Research And Studies
Digital Stress Among University Students in Light of Certain Variables
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This study aimed to measure digital stress among students at the University of Baghdad and to identify differences in digital stress based on gender (male–female), academic level (first–fourth year), and field of study (scientific–humanities). The study sample consisted of 200 students from the University of Baghdad. The "Digital Stress" scale, developed by the researcher specifically for this study, was applied, and the descriptive-analytical method was adopted. After administering the scale and analyzing the results using appropriate statistical methods, the findings indicated that university students experience a high level of digital stress, while no statistically significant differences were found in digital stress accord

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Publication Date
Fri Apr 12 2019
Journal Name
Journal Of Economics And Administrative Sciences
Core competencies and Their Role in Enhancing Organizational flexibility: An Analytical Study of the Views of a Sample of Employees in Presidency University of Mosul
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Abstract

The study aims to identify the levels of core competencies dimensions and types of organizational flexibility in the investigated organization, as well as to determine the nature of the relationship and the impact of core competencies dimensions with the process of organizational flexibility. Thus, a number of research questions were presented to express the research problem as follows:

  • What is the level of the investigated individuals' awareness to core competencies and organizational flexibility across their dimensions and types in the investigated organization?
  • To what extent are core competencies and organizational flexibility available in the Organiz

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Publication Date
Tue Mar 01 2022
Journal Name
Iraqi Journal Of Physics
The Confinement Profile Effect on the Optical Properties in Different Inverse-shaped Single InGaN/GaN Quantum Wells
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In this work, the effects of size, and temperature on the linear and nonlinear optical properties in InGaN/GaN inverse parabolic and triangular quantum wells (IPQW and ITQW) for different concentrations at the well center were theoretically investigated. The indium concentrations at the barriers were fixed to be always xmax = 0.2. The energy levels and their associated wave functions are computed within the effective mass approximation. The expressions of optical properties are obtained analytically by using the compact density-matrix approach. The linear, nonlinear, and total absorption coefficients depending on the In concentrations at the well center are investigated as a function of the incident photon energy for different

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Publication Date
Thu Nov 13 2014
Journal Name
Asian Academic Research Associates
Thermodynamic Study of Poly (Vinyl Alcohol) in Aqueous Solution and in Tetrahydrofurfuryl alcohol at Different Temperatures
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Publication Date
Fri Sep 30 2022
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Laboratory Testing and Evaluating of Shale Interaction with Mud for Tanuma Shale formation in Southern Iraq
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   Rock failure during drilling is an important problem to be solved in petroleum technology. one of the most causes of rock failure is shale chemical interaction with drilling fluids. This interaction is changing the shale strength as well as its pore pressure relatively near the wellbore wall. In several oilfields in southern Iraq, drilling through the Tanuma formation is known as the most challenging operation due to its unstable behavior. Understanding the chemical reactions between shale and drilling fluid is determined by examining the features of shale and its behavior with drilling mud. Chemical interactions must be mitigated by the selection of suitable drilling mud with effective chemical additives. This study is describing t

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Publication Date
Tue Jan 01 2019
Journal Name
Aip Conference Proceedings
Studying the partial substitution of barium with cadmium oxide and its effect on the electrical and structural properties of HgBa2Ca2Cu3O8+δ superconducting compound
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Publication Date
Tue Jan 01 2019
Journal Name
Energy Procedia
Improvement the Superconducting properties of TlBa2 Ca2 Cu3xNix O 9-δ superconducting compound by partial substitution of copper with nickel oxide on the
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