Abstract: Objectives: To investigate the effect of temperature elevation on the bonding strength of resin cement to the zirconia ceramic using fractional CO2 laser. Background: Fractional CO2 laser is an effective surface treatment of zirconia ceramic, as it increases the bonding strength of zirconia to resin cement. Methods: Thirty sintered zirconia discs (10 mm diameter, 2 mm thickness) were prepared and divided to three groups (N=10) and five diffident pulse durations were used in each group (0.1, 0.5, 1, 5 and 10 ms). Group A was treated with 10 W power setting, group B with 20 W and group C with 30 W. During laser irradiation, temperature elevation measurement was recorded for each specimen. Luting cement was bonded to the treated zirconia surfaces and cured for 30 seconds. Shear bond strength was evaluated by a testing machine (universal) with bond failure mode determination. Results: The lowest temperature elevation measurement of the irradiated specimen which gave maximum shear bond strength was about 1.6±0.3 Ċ higher than ambient room temperature (27±0.2 ºC). Apparent micromechanical irregularities were seen in the treated samples and cracks formation with increased pulse duration and power setting were also observed. Conclusions: The temperature elevation is a vital factor in the surface roughness of zirconia ceramic with fractional CO2 laser irradiation and the lowest temperature elevation at best shear bond strength of zirconia ceramic to the resin cement is satisfied with the shorter pulse duration of 0.1 millisecond.
In this paper, three approximate methods namely the Bernoulli, the Bernstein, and the shifted Legendre polynomials operational matrices are presented to solve two important nonlinear ordinary differential equations that appeared in engineering and applied science. The Riccati and the Darcy-Brinkman-Forchheimer moment equations are solved and the approximate solutions are obtained. The methods are summarized by converting the nonlinear differential equations into a nonlinear system of algebraic equations that is solved using Mathematica®12. The efficiency of these methods was investigated by calculating the root mean square error (RMS) and the maximum error remainder (𝑀𝐸𝑅n) and it was found that the accuracy increases with increasi
... Show MoreBackground: Type 2 diabetes mellitus (T2DM) is a chronic disorder that constitutes a major health problem worldwide. Toxoplasma gondii is an intracellular parasite that may infect any nucleated cell. Toxoplasmosis is becoming a worldwide health threat, infecting 30–50% of the world’s human population. The studies that have been undertaken to investigate the link between T. gondii infection and diabetes have shown contradictory fi ndings. This research aimed to look at the possible link between T2DM and T. gondii infection. Methods and Subjects: The enzyme-linked immunosorbent assay (ELISA) approach was used to screen for T. gondii IgM and IgG antibodies in 69 patients with T2DM and 92 seemingly healthy persons as controls. Resul
... Show MoreObjectives: ٨ descriptive study has been conducted in the premature baby unit in Al-Khansaa' and Al-Batool
hospitals for maternity and children in Mosul city to assess knowledge and practice of the nursing staff in the
caring of premature infants. A descriptive study has been conducted in the premature baby unit in Al-Khansaa'
and Al-Batool hospitals for maternity and children in Mosul city to assess knowledge and practice of the nursing
staff in the caring of premature infants.
Methodology: the data were collected by using knowledge assessment and practice measurement tool.
Results: the results of the study show that high percentages (about 40%) of the staff who work in the premature
baby units are of the young age
The oil exports play a vital role in supporting economic development and raise the economic growth. The oil exports can increase the economic growth via three main channels which are supporting the productive, distributive and service sectors; increasing the investment and capital formation; and increasing the employment rate.
However, the oil exports did not have an important role in increasing the economic growth in Iraq. Therefore, it also did not provide the required support to other economic sectors, neither participated in increase the employees’ skills nor increase the investment rate. It may slightly contribute in enhancement the infrastructure that can attract the public and private investments
... Show MoreThis investigation was conducted to recognize the structure for (RHETI version 2.5 1999) by using exploratory and confirmatory factor analysis. Sample of (620) student of Al-Mustansrya University were administered the (RHETI).
The data of their responses was analyzed by using (PAF) and oblique rotating .
The findings explored (9) factors as one factor for each type and (184) items were loaded by the factors: (60) item for feeling center, (61) items for instinctive center and (63) items for thinking center.
Results of confirmatory factorial analysis supported a model designed by the researcher depended upon a theoretical views of Riso and Hudson
... Show MoreThe PbSe alloy was prepared in evacuated quarts tubs by the method of melt quenching from element, the PbSe thin films prepared by thermal evaporation method and deposited at different substrate temperature (Ts) =R.T ,373 and 473K . The thin films that deposited at room temperature (R.T=303)K was annealed at temperature, Ta= R.T, 373 and 473K . By depended on D.C conductivity measurements calculated the density of state (DOS), The density of extended state N(Eext) increases with increasing the Ts and Ta, while the density of localized state N(Eloc) is decreased . We investigated the absorption coefficient (?) that measurement from reflection and transmission spectrum result, and the effect of Ts and Ta on it , also we calculated the tai
... Show Morestudy aimed to recognize The relationship between Intrinsic Motivation Academy and Time Management among University students and measure Intrinsic Motivation Academy And Time Management for sample and Balancing Degrees of Basic Research on the two scales According to the Variable genders and Specialization, The sample consisted (350) students by (230) female (120) male , and the sample responded scales of Intrinsic Motivation Academy for (Alwan & Attaat2009) and Time Management (Building tool), The Results of this study show that: There are statistically significant differences according to gender variable in Intrinsic Motivation Academy and Time Management in favor of the male, and there are statistica
... Show MorePDBNRSIA Asst, International Journal of Research in Social Sciences and Humanities, 2018
Abstract :
The aim of the study is to diagnose the level and nature of the relationship between cognitive interactions, cognitive ignorance and the achievement of strategic excellence). The aim of this is to explore theoretical philosophy and intellectual implications of these variables, and, then test the correlation and impact relationships and their feasibility in the application environment, which was formed from the seven directorates in the Ministry of Education. The sample of the study was determined by the directors, their assistants, and the department directors. The sample number is (130). The importance of the study is to come out with a philosophical basis for the nature of the variables, based on an app
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