Background: This in vitro study measure and compare the effect of light curing tip distance on the depth of cure by measuring vickers microhardness value on two recently launched bulk fill resin based composites Tetric EvoCeram Bulk Fill and Surefil SDR Flow with 4 mm thickness in comparison to Filtek Z250 Universal Restorative with 2 mm thickness. In addition, measure and compare the bottom to top microhardness ratio with different light curing tip distances. Materials and Method: One hundred fifty composite specimens were obtained from two cylindrical plastic molds the first one for bulk fill composites (Tetric EvoCeram Bulk Fill and Surefil SDR Flow) with 4 mm diameter and 4 mm depth, the second one for Filtek Z250 Universal Restorative with 4 mm diameter and 2 mm depth. Each spcimen was light-cured using WOODPECKER LED CURING LIGHT for 20 sec. Polymerization was performed with the light tip positioned in direct contact, 2 mm, 4 mm, 6 mm and 8 mm distant from the top surface of the sample. After one day of storage in distilled water in a light proof container at 37ËšC, the hardness on the bottom and top surfaces of each specimen was tested using the Digital Micro Vickers Hardness Tester. Then the Data were analyzed statistically by ANOVA test, LSD test and t-test. Results: All experimental groups show top microhardness higher than bottom microhardness with high significant difference with all light tip distances. At 0 mm light tip distance all groups give the highest microhardness value. Filtek Z250 Universal Restorative shows accepted bottom to top microhardness ratio at all light tip distances. Surefil SDR Flow shows accepted bottom to top ratio only at 0, 2 and 4mm light tip distances while Tetric EvoCeram Bulk Fill shows the bottom to top microhardness ratio less than the accepted value with all light tip distances. Conclusion: From the results of this study we can conclude that the polymerization of bulk fill composite depends greatly on the distance from light curing tip, Tetric EvoCeram Bulk Fill composite not recommended to be used as bulk fill restoration in deep cavities and need further studies, while Surefil SDR Flow not recommended to be used in deep cavity when curing tip distance (6-8 mm), in addition we can conclude that the thickness of the increments is more important than light curing tip distance.
Of the new concepts introduced by the decree of the amendment of the French Civil Code No. 131-2016 issued on 10 February 2016, which raised a debate in jurisprudence both at the level of French jurisprudence or the Arab, the concept of (the content of the contract), which seems to have emerged from the appearance of new legal articles ( 1162-1171) is the cornerstone of the contract and the contract in the contract, the two pillars which, over the course of 200 years and a half, have been one of the main pillars of the codification of Napoleon. Is that the decree of amendment has already abandoned these two pillars, or most of what he did is a change in terminology while preserving the content of these two pillars implicitly, this is what w
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The research aims to identify how to audit potential liabilities and contingent liabilities in light of the pandemic and its reflection on the auditor's report. The research problem is represented by the complexity of the process of checking potential liabilities and contingent liabilities in insurance companies, which was negatively reflected in the auditor's neutral technical opinion. The researchers hypothesize that auditing potential liabilities and contingent liabilities in light of the Corona pandemic is positively reflected in the auditor's report. The research concludes that the process of checking potential liabilities and contingent liabilities is
... Show MoreAccounting disclosure is the main means and effective tool for communicating business results to users in support of their decisions, especially those with thought and specialization from academics and professionals in the field of accounting and auditing about the importance of accounting disclosure and transparency in financial reports.
Contingent liabilities represent commitments based on the occurrence of one or more events in the future to confirm the value due, the party entitled to it, the maturity date, or to confirm the existence of the obligation itself, and therefore they should not be recognized as a contingent liability i
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The research aims to identify the level of effectiveness of the teaching practices of science and mathematics teachers in light of the national framework for future skills in Omani schools. To achieve the objectives of the study, the researchers used the descriptive approach, as he designed a note card consisting of (30) phrases distributed on three axes: basic skills, practical skills, and technical skills. After verifying the validity and reliability of the tools, they were applied to a sample of (116) teachers. The results of the research revealed that the level of effectiveness of the teaching practices of mathematics teachers has recorded a medium degree with a mean (3.05). The results a
... Show MoreRutting in asphalt mixtures is a very common type of distress. It occurs due to the heavy load applied and slow movement of traffic. Rutting needs to be predicted to avoid major deformation to the pavement. A simple linear viscous method is used in this paper to predict the rutting in asphalt mixtures by using a multi-layer linear computer programme (BISAR). The material properties were derived from the Repeated Load Axial Test (RLAT) and represented by a strain-dependent axial viscosity. The axial viscosity was used in an incremental multi-layer linear viscous analysis to calculate the deformation rate during each increment, and therefore the overall development of rutting. The method has been applied for six mixtures and at different tem
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In this paper, an exact stiffness matrix and fixed-end load vector for nonprismatic beams having parabolic varying depth are derived. The principle of strain energy is used in the derivation of the stiffness matrix.
The effect of both shear deformation and the coupling between axial force and the bending moment are considered in the derivation of stiffness matrix. The fixed-end load vector for elements under uniformly distributed or concentrated loads is also derived. The correctness of the derived matrices is verified by numerical examples. It is found that the coupling effect between axial force and bending moment is significant for elements having axial end restraint. It was found that the decrease in bending moment was
in the
The research aims to identify ways of upgrading the quality level of university education at the Middle Technical University in light of its application for the National Ranking project for the quality of Iraqi universities in order to obtain advanced grades among the Iraqi universities , Which is qualified to enter the Ranking of universities worldwide, through displaying the mechanism of the Application of National Ranking project for the quality of Iraqi universities in the Middle Technical University and its formations consisting of (5) technical colleges and (11) technical institute.
The results of the application showed several observations: The most
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The research deals with the statement of the importance of unanimous in Islamic Sharia in terms of being the third source of Islamic legislation after the Holy Qur’an and the Sunnah of the Prophet, and the extent of interest of the scholars of interpretation in it, and those who took great interest in mentioning what was agreed upon in every site that necessitated mentioning its issues within, or mentioning an event that has encountered an unanimous, and in various sciences, to extract and extrapolate Sharia rules when these rules are lost in the texts, because it is based on them and derived from them. Among these distinguished scholars is Muhammad bin Jarir al-Tabari. Besides, the research discusses in
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Background: Several infectious lung diseases often develop in patients with Rheumatoid arthritis (RA), especially during immunosuppressive medication, including disease-modifying anti-rheumatic drugs (DMARDs). The present study aimed to determine the role of respiratory tract bacterial infection in RA activity. Methods: Blood and sputum samples were collected from 31 patients with RA and 12 healthy subjects as control. The bacterial isolates were isolated and identified in collected sputum by biochemical tests and Vitec 2 system. Results: In the present study, thirty-one patients with RA were compared with 12 healthy subjects. Eight patients with RA were not infected with pathogenic bacteria (RA-NIPB) (25.8%). Twenty-three RA patients wer
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