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.
Background: Understanding the morphological characteristics between the floor of the maxillary sinus and the tips of the maxillary posterior roots is crucial in orthodontics involving diagnosis and treatment planning. The aim of this study was to evaluate the distances from the maxillary posterior root apices to the inferior wall of the maxillary sinus, thickness and density of maxillary sinus floor using cone-beam computed tomography images and the relationships between roots and maxillary sinus according to gonial angle and skeletal pattern. Materials and methods: Three-dimensional images of each root were checked, and the distances were measured along the true vertical axis from the apex of the root to the sinus floor, and the thickne
... Show MoreThe parametric programming considered as type of sensitivity analysis. In this research concerning to study the effect of the variations on linear programming model (objective function coefficients and right hand side) on the optimal solution. To determine the parameter (θ) value (-5≤ θ ≤5).Whereas the result، the objective function equal zero and the decision variables are non basic، when the parameter (θ = -5).The objective function value increases when the parameter (θ= 5) and the decision variables are basic، with the except of X24, X34.Whenever the parameter value increase, the objectiv
... Show MoreQuantum dots of CdSe, CdS and ZnS QDs were prepared by chemical reaction and used to fabricate organic quantum dot hybrid junction device. QD-LEDs were fabricated using layers of ITO/TPD: PMMA/CdSe/Alq3, ITO/TPD: PMMA/CdS/Alq3 and ITO/TPD: PMMA/ZnS/Alq3 devices which prepared by phase segregation method. The hybrid white light emitting devices consists, of three-layers deposited successively on the ITO glass substrate; the first layer was of N, N’-bis (3-methylphenyl)-N, N’-bis (phenyl) benzidine (TPD) polymer mixed with polymethyl methacrylate (PMMA) polymers. The second layer was QDs while the third layer was tris (8-hydroxyquinoline) aluminium (Alq3
... Show MoreThe research aims to identify the impact of managing performance's employees in building intellectual capital, Because employing the practice of managing the performance of employees may acquire familiar skills to improve their performance and reflect on the construction of intellectual capital in the surveyed area, Especially that the independent dimension represented by the management of the performance of employees is one of the important topics that has received attention in the world of management in general and human resource management in particular. While the adopted dimension was represented by Intellectual capital in the important practice of human resource management in the increasing of their knowledge, to
... Show MoreThis study examines how Sahar Mustafah's book The Beauty of Your Face (2020) examines the intersectional aspects of Arab American identity. The novel traces the life of the Palestinian Arab American woman, Afaf Rahman who is a school principal. She negotiates the intricacies of gendered, religious, and cultural identities in America after 9/11. The analysis uses an intersectional lens to look at how Afaf's experiences as a woman, a Muslim, and an immigrant combine to influence how she sees herself and how she interacts with society at large. The book explores racial prejudice, misogyny, and Islamophobia, bringing to light the many difficulties Arab American women experience. Additionally, it shows the protagonist's autonomy and tenacity as
... Show MoreQuality of e-service is one of the critical factors that decide the success or failure of organizations. It may increase competitive advantages as well as enhance the relationships with the customers. Achieving high e-service quality and user satisfaction are challenging since they depend fundamentally on user perception and expectation which can be tricky at times. To date, there is no agreement as to what service quality is, and how it should be measured, whether it is a function of statistical measures of quality including physical defects or managerial judgment, or it is a function of customer perception about the services. This paper deep-dived the quality of e-services offered b
Earthquakes in the Holy Qur’an and the Hadith of the Noble Prophet, an intellectual approach
The research aimed to test the effect of independent variables career plateaus and workaholism on employees loyalty through the influence of the mediator variable organizational socialization. Descriptive approach with survey style on a sample of managers and executives in the Iraqi Drilling Company in Basra's (123) employees. The most important findings of the research are: the existence of a significant effect of the independent variables career plateaus and workaholism in employees loyalty by having a mediator variable organizational socialization and introduced numerical from recommendations. &nbs
... Show MoreCorruption, 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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