Background: To evaluate the ISO depth of cure of bulkfill composites and depth of cure which determined by Vickers microhardness test. Materials and Methods: Bulkfill resin composite specimens (n=150) were prepared of three bulkfill composite materials (TetricEvo Ceram, Quixfil and SDR) and light cured by Flash max p3 for 3, 10, 20 seconds and by wood pecker for 10, 20 seconds respectively, a mold was filled with one of the three bulkfill composites and light cured. The specimens removed from the mold and scraped by plastic spatula and the remaining length (absolute length) was measured which represent the ISO depth of cure. After that the specimens were returned into the mold and a microhardness indentation device applied on the specimen and hardness measurements (Vickers hardness, VHN) were made at defined distance, beginning at the resin composite that had been closest to the light curing unit (i.e. at the top) and proceeding toward the uncured resin composite (i.e. toward the bottom) on the basis of the VHN measurement, Vickers hardness test generated for each group. Results and Conclusion: ISO depth of cure of bulkfill composite materials is time and type of light curing protocol dependent rather than type of material of bulkfill composite while the depth of cure determined by Vickers hardness number is material dependent in addition to the light curing protocol. Key words: Bulkfill composite light curing intensity, depth of cure.
The effect of air injection angle on the performance of airlift pump used for water pumping has been studied analytically and experimentally. An airlift pump of dimensions 42mm diameter and 2200 mm length with conventional and modified air injection device was considered. A modification on conventional injection device (normal air-jacket type) was carried out by changing injection angle from 90 (for conventional) to 45 and 22.5 (for modified). Continuity and one-dimensional momentum balance for the flow field with basic principle of two-phase flow and expressions of slip ratio and friction factor as function of flow rates were formulated. The analytical and experimental investigations were carried out f
... Show MoreBuried pipeline systems are commonly used to transport water, sewage, natural oil/gas and other materials. The beneficial of using geogrid reinforcement is to increase the bearing capacity of the soil and decrease the load transfer to the underground structures.
This paper deals with simulation of the buried pipe problem numerically by finite elements method using the newest version of PLAXIS-3D software. Rajkumar and Ilamaruthi's study, 2008 has been selected to be reanalyzed as 3D problem because it is containing all the properties needed by the program such as the modulus of elasticity, Poisson's ratio, angle of internal friction. It was found that the results
... Show MoreThis study aimed to reveal the extent to which the values of social peace are included in the content of social and national studies textbooks of the middle stage in kingdom of Saudi Arabia. To achieve this goal, the researcher used the descriptive analytical approach. The study sample consisted of all developed social and national studies textbooks of the middle stage in kingdom of Saudi Arabia in first and second semester of student books in edition of 1439-1440. The study tool was the analysis card. The study reached the following results: 1-The content of social and national studies textbooks of the middle stage in kingdom of Saudi Arabia as a whole included (38) social peace values of total (40) values, corresponding to the inclusio
... Show MoreImportance of accounting standards belong to be the instructor and the advisor for accountant in performing his work . For each invironment a group of political, social, economical and cultural factors which distinguish it about other environments . In order to perform its aim in produsing accouting information helps in making decisions on different levels, accounting standards should established in a form that harmonized with the environment that apply in it . Establishing international accounting standards comes with the same direction and then it has put influential with standards some states that have influence on international accounting standards committee. So because of the big changes that happened in the inte
... Show MoreIn this paper, the dynamics of scavenger species predation of both susceptible and infected prey at different rates with prey refuge is mathematically proposed and studied. It is supposed that the disease was spread by direct contact between susceptible prey with infected prey described by Holling type-II infection function. The existence, uniqueness, and boundedness of the solution are investigated. The stability constraints of all equilibrium points are determined. In addition to establishing some sufficient conditions for global stability of them by using suitable Lyapunov functions. Finally, these theoretical results are shown and verified with numerical simulations.
The semiconductor ZnO is one of II – VI compound group, it is prepare as thin films by using chemical spray pyrolysis technique; the films are deposited onto glass substrate at 450 °C by using aqueous zinc chloride as a spray solution of molar concentration 0.1 M/L. Sample of the prepared film is irradiating by Gamma ray using CS 137, other sample is annealed at 550°C. The structure of the irradiated and annealed films are analyzed with X-ray diffraction, the results show that the films are polycrystalline in nature with preferred (002) orientation. The general morphology of ZnO films are imaged by using the Atomic Force Microscope (AFM), it constructed from nanostructure with dimensions in order of 77 nm.
The optical properties o
Ceramic coating compose from a ceramic mixture (MgO, Al2O3) and metall (Al-Ni) were produced by Thermal Spray Technique. The mixed ratio of used materials Al:Ni (50%) and 40% of Al2O3 and 10% MgO. This mixture was spray on a stainless steel substrate of type (316 L) by using thermal spray with flame method and at spraying distances (8, 12, 16 and 20) cm, then the prepared films were treated by laser and thermal treatment. After that performing a hardness and adhesion tests were eximined. The present study shows that the best value of the thermal treatment is 1000 ℃ for 30 mint; the optimum spray distance is 12 cm and most suitable laser is 500 mJ where the microscopic and mechanical character
... Show MoreConsidering the science of speech in the light of its purposes is an accurate scientific study that looks at it from its reality in which it originated, and its topic that it dealt with and its goals that it sought, and it follows its main course in the directions of approving the belief and inferring it, and repelling the objections to it, and this study comes to show the realism of the science of speech in its emergence Its subject and method, since its launch was from the reality of the Islamic nation and based on its intellectual needs, so its presence was necessary in the life of the Islamic nation because of its role in facing the challenges faced by the Islamic faith, and the dangers it was exposed to as a result of the intellectu
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