The zirconia ceramic restoration (ZCR) is used as substitutes for the metal-ceramic restoration. Clinical studies demonstrating of ZCRs showed a high fracture incidence of veneering layer than metal-ceramic restorations. This attributed to the low bond strength of zirconia to veneering ceramic as a result of lacking of glass content in its matrix. Surface treatment was proposed to improve the bonding strength between zirconia and veneering ceramic. Several studies revealed that some treatment such as airborne particle abrasion (APA) is responsible for generating chipping of veneering ceramic. The study aimed to develop a new zirconia coatings to increase bonding strength between zirconia substrate and veneering porcelain. Three groups of 150 zirconia specimens (discs, rods and crowns) were divided according to the type of surface treatments; Group M1 designated unsintered zirconia specimens coated with a mixture of glaze porcelain powder and partially-sintered zirconia powder prepared at 1100 °C with two particle sizes; A (26 ± 0.3 μm) and size B (47 ± 0.5 μm), group M2 was coated with mixture of ceramic liner paste and same selected particle sizes of partially-sintered zirconia powders. The coated groups (M1 and M2) subdivided according to powder sizes into M1A, M1B, M2A and M2B. APA group (as control) of sintered zirconia specimens abraded with 50 μm aluminium oxide powder. Surface area roughness (Sa) was measured by surface texture analyser. Surface morphology and elemental composition were analysed by scanning electron microscope (SEM). Crystallographic phases were identified by X-ray diffraction (XRD). The coefficient of thermal expansion (CTE) was assessed by a thermomechanical analyser. For shear bond strength (SBS) test was evaluated by a universal testing machine (UTM). The fracture strength (FS) test prepared and measured by Cercon CAD/CAM system and UTM. Fractographic analysis for SBS and FS were examined by a stereomicroscope and SEM. For each test and measurement, 10 specimens were used per group. Finite element analysis (FEA) was used to simulate and predict the iv stress distributions of the static oblique load in coated and non-coated zirconia crown models. The collected data were analysed by one-way ANOVA and Tukey HSD test at (P<0.05). Surface roughness results showed significant differences among all groups (P<0.000). The M1B group exhibited a higher Sa value (10.33 ± 0.59 μm) among the tested groups. XRD analysis showed tetragonal and monoclinic phases in the control group while only tetragonal was detected in the coated groups. The SBS values for coated groups were higher than the control group. The M1B group showed higher and significant differences in SBS value (37.54 ± 4.38 MPa) among other tested groups (P<0.05). The FS test indicated that coated M1B group (647.92 ± 97.33 N) higher than the other groups (P<0.00). FEA showed the coated crown models have lower stress level than the non-coated model. The new coating (M1B) by airbrush spray technique considered as an alternative way to APA treatment to improve the bond strength of zirconia substrate to veneering ceramic and indicating as an applicable surface treatment for improving the clinical performance of the coated ZCR.
The aim of this study was to determine the effect on using the McCarthy Model (4MAT) for developing creative writing skills and reflective thinking among undergraduate students. The quasi-experimental approach was adopted. And, in order to achieve the study objective, the educational content of Teaching Ethics (Approach 401), for the plan for the primary grades teacher preparation program was dealt with by using a teaching program based on the McCarthy Model (4MAT) was used.
The study which was done had been based on the academic achievement test for creative writing skills, and the reflective thinking test. The validity and reliability of the study tools were also confirmed. The study was applied to a sample consisting of
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Objectives: The study aims to know the effectiveness of the educational program in the patient’s adherence to medication and diet and to know the relationship between the effectiveness of the education program and their demographic data related to the patient’s age, gender, marital status, education level, occupation, monthly income and residence.
Methodology: A quasi -experimental design study was performed on patient who attended to Gastroenterology and Hepatology Teaching Hospital, from March 2021 to September 2021. The non-probability sampling including 50 patients for case study and 30 patients for control group. The questionnaire consists of 3 parts, part one the socio
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Summary
The book (Fatah al-Rahman reveals what is ambiguous in the Qur’an), which is a book of verbal similarities that tries to touch the Qur’an expression, and the subtle differences between its expressions and expressions. It appeared when it appeared in many chapters, from which I chose to delete in monolithic letters such as Ba and Ta, and to heal and delete in non-monosymbols such as (that) and (may) and (no), so the search came to two chapters The first is for deleting the monolithic letters, and the second is for deleting non-monosyllabic letters, preceded by introductory discussions revolving around the linguistic and idiomatic definition of deletion, a brief translation of the
... Show MoreA free convective heat transfer from the inside surface of a uniformly heated vertical circular tube has been experimentally investigated under a constant wall heat flux boundary condition for laminar air flow in the ranges of RaL from 6.9108 to 5109. The effect of the different sections (restrictions) lengths placed at the exit of the heated tube on the surface temperature distribution, the local and average heat transfer coefficients were examined. The experimental apparatus consists of aluminum circular tube with 900 mm length and 30 mm inside diameter (L/D=30). The exit sections (restrictions) were included circular tubes having the same inside diameter as the heated tube but with different lengths of
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It highlights the importance of assessing the demand for money function in Iraq through the understanding of the relationship between him and affecting the variables by searching the stability of this function and the extent of their influence in the Iraqi dinar exchange rate in order to know the amount of their contribution to the monetary policies of the Iraqi economy fee, as well as through study behavior of the demand for money function in Iraq and analyze the determinants of the demand for money for the period 1991-2013 and the impact of these determinants in the demand for money in Iraq.
And that the problem that we face is how to estimate the total demand for money in
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This research investigates the meanings and significance of the verse and the concluded educational purports. The expression “And in the heaven is your provision” signifies the deism of Allah. This research introduces the what have been said by Quran Explainers about meaning of Heaven & Provision. It introduces also the meaning of the sentence “which you are promised” and its concluded educational purports. This research discuses the role of educational institutions as well as the family and mosques in connecting Muslims and their children with the promise given by Allah.
Provision is guaranteed for all people if moral and material causes have been considered.
Key Words:
Purports – Educational – Co
... Show MoreThe 8 - mixing ratios of 7 - transitions from levels of 26 Mg populated in 23 Na (a, py)26Mg reaction are calculated using a2 — ratio method for the first time in the case of two mixed y - transitions from the same initial level. The results obtained have been compared with 8 - values determined by other methods. The comparison shows that the agreement is excellent. This confirms the validity of this method in calculating the 6 - values of such 7 - transitions.
This research means a study (the impact of the Arab-Islamic environment on contemporary painting, the artist Abd al-Rahman al-Suleiman as a model). The research falls into two axes: the first: the theoretical axis, and the second: the applied axis. The first axis dealt with an introduction that contained: (the research problem, its importance, its goal, its limits, and the definition of terms). This research aims to uncover (the impact of the Arab-Islamic environment on contemporary painting, and the artist Suleiman was a model). And the research limits spatially: Saudi Arabia, and temporally: 2010-2014. This theme included two topics: The first: the characteristics of the Saudi environment and its impact on art. The second: the s
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The research aims to evaluate the direct deduction department’s procedures for the process of collecting income tax using the direct deduction method for state departments and the public sector in light of direct deduction tax instructions No. (1) of 2007 and Income Tax Law No. (113) of 1982 (amended) through Giving a clear idea of the reality of tax collection procedures because this type of tax is one of great importance because it contributes to the provision of financial revenues to the state to finance its expenses and direct the economy towards achieving its social, economic and political goals. The researcher makes comparisons between the procedures of the General Tax Authority in collecting the tax and what was approved b
... Show MoreIn this work lactone (1) was prepared from the reaction of p-nitro phenyl hydrazine with ethylacetoacetate, which upon treatment with benzoyl chloride afforded the lactame (2). The reaction of (2) with 2-amino phenol produced a new Schiff base (L) in good yield. Complexes of V(IV), Zr(IV), Rh(III), Pd(II), Cd(II) and Hg(II) with the new Schiff base (L) have been prepared. The compounds (1, 2) were characterized by FT-IR and UV spectroscopy, as well as characterizing ligand (L) by the same techniques with elemental analysis (C.H.N) and (1H-NMR). The prepared complexes were identified and their structural geometries were suggested by using elemental analysis (C.H.N), flame atomic absorption technique, FT-IR and UV-Vis spectroscopy, in additio
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