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The effect of different curing distances on the microhardness of flowable bulk-fill composite materials
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Background: The microhardness of a composite resin is a vital parameter that is used to determine its clinical behavior. Measuring the microhardness of a composite resin has been used as an indirect method to assess its degree of conversion and extent of polymerization. The purpose of this in vitro study was to evaluate the effect of three curing distances (0, 2, and 4 mm) on the microhardness of the top and bottom surfaces of three types of flowable bulk-fill composite resins (smart dentin replacement, Opus bulk fill flow, and Tetric N). Material and method: Sixty-three specimens from the three types of composite resins (n=21) were fabricated using Teflon mold with a 4mm depth and a 5 mm internal diameter and cured for 20 seconds. For each material, three subgroups were fabricated according to the position of the light curing tip from the top surface; at 0, 2, and 4 mm distances. Microhardness was measured using the Vickers test with a 50-g load for 15 seconds for the top and bottom surfaces of all the samples. Results: The microhardness values were decreased in the following order; 0mm > 2mm > 4mm curing tip distance, for both sides and Tetric N had the highest microhardness values. Significant differences in microhardness were recorded between the top and bottom surfaces for all the specimens (p<0.05). Conclusion: Increasing the distances between the tip of the light cure and the surface of flowable bulk-fill resins can significantly decrease the microhardness of the bottom surfaces compared to the top surfaces.

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Publication Date
Tue Mar 31 2015
Journal Name
Al-khwarizmi Engineering Journal
Influence of Coating with Some Natural Based Materials on the Erosion Wear Behavior of Glass Fiber Reinforced Epoxy Resin
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Abstract 

In the present study, composites were prepared by Hand lay-up molding. The composites constituents were epoxy resin as a matrix, 6% volume fractions of glass fibers (G.F) as reinforcement and 3%, 6% volume fractions of preparation natural material (Rice Husk Ash, Carrot Powder, and Sawdust) as filler. Studied the erosion wear behavior and coating by natural wastes (Rice Husk Ash) with epoxy resin after erosion. The results showed the non – reinforced epoxy have lower resistance erosion than natural based material composites and the specimen (Epoxy+6%glass fiber+6%RHA) has higher resistance erosion than composites reinforced with carrot powder and sawdust  at 30cm , angle 60

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Publication Date
Fri Jul 01 2022
Journal Name
Journal Of Engineering
A Review of the Asphalt Mixtures Containing Recycled Solid Waste Materials
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Landfill and incineration are the most common and widely used methods to dispose of solid wastes; both of these techniques are considered the main sources of pollution in the world due to the harmful toxic emissions that are considered an environmental problem. Because of the large areas used by landfills, they are not always considered an economical method. With the increase in the production of solid materials, solid wastes increase the pressure on incinerators and landfills, making the environmental pollution hazard more serious. Instead, these waste materials can be used in some other applications. One of the most important of these applications is asphalt pavements, which are the most used types of pavements in the

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Publication Date
Sat Dec 01 2018
Journal Name
Al-khwarizmi Engineering Journal
Study the Characterizations of Cement Mortar by Nano Pozzolanic Materials Additions
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This study involves adding nano materials and interaction with cement mortar behavior for several mortar samples under variable curing time with constant water to cement ratio (W/C = 0.5). The effects of adding nano materials on the microstructure of cement mortar were studied by (Scanning Electronic Microscopy (SEM) and X-Ray (for samples at different curing time 28 and 91 days. Small ratio replacements of nano particles (SiO2 or Al2O3) were added to Ordinary Portland Cement (OPC) type (I). The percentage of nano materials additives replacement by weight of ordinary Portland cement includes (1, 2, 3, 4 and 5%) for both types of nano materials with constant (W/C) ratio, also the amount of the fin

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Publication Date
Tue Jun 14 2016
Journal Name
Al-academy
Employment educational and artistic style of fiction in the textbook materials
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Find goal to detect educational and technical staffing of style fiction in book reading school materials so determine the current research on the specific book reading in fourth grade of primary for the academic year 2014 issued by the Ministry of Education / Republic Iraq stories. Come in the importance of research to draw attention to the best of these stories and strengthened, and the negative deny it and claim his deportation in order to protect the thought of the learner, and the study may contribute to the development of some frameworks to write a story appropriate for elementary school. This McCann within the first chapter The second chapter included the theoretical framework has been contained on two main sections included the co

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Publication Date
Sun Jan 06 2013
Journal Name
Journal Of Educational And Psychological Researches
The reality of teaching performance materials for teachers of social primary stage
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    The teacher is the most able to achieve the goals of education in education because he has the ability to affect the behavior of the disciples testified and its actions and appearance and other actions that convey pupils with it sometimes in a manner unconscious or unconscious , and the importance of the role of the teacher in the educational process , it is necessary to compromise the care and attention to the extent that commensurate with the important role that the rise in the preparation of youth and composition , and as a result is needed to continue efforts to improve the quality of teacher preparation so that it can be more effective and positive in the educational process .
First - Research Goals -<

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Publication Date
Sun Sep 01 2019
Journal Name
Research Journal Of Pharmacy And Technology
Effect different concetration and pH on complexes formation of New Tetradentate Schiff base Ligand
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New N2O2 donor kind Schiff basehas been destined and structured by reaction Ampyrone with O-hydroxyacetophenone and Anthranilic acid. The metal complexes of the Schiff base with Mn(II), Hg(II), Ni(II), Cu(II), and Co(II) metal ions were designed and characterized by magnetic susceptibility, elemental analyses, molar conduction, IR, and 1H NMR,UV-Vis spectral metrics.The UV-Vis. and magnetic susceptibility data of the complexes suggest a square-planar, tetrahedraland octahedral geometries around the central metal ions. All elaborations were accomplished after determination the optimum molar concentration and pH which followed law of Lambert-Beer's in the researches pH scopes. The composition of these complexes were conclude dapprobating to t

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Scopus
Publication Date
Sun Jan 01 2023
Journal Name
The Egyptian Journal Of Hospital Medicine
Training of Skilled Force with The Different Medical Ball and Their Effect on Developing Some Special Physical Abilities and the Accuracy of Long Shooting Performance in Handball
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Publication Date
Fri Jan 01 2021
Journal Name
Journal Of Economics And Administrative Sciences
The effect of strategic alignment on the reputation of the organization
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The current study aims to determine the extent of SOMO's interest in strategic alignment operations and whether this interest is sufficient to be reflected in enhancing its organizational reputation. The field of research was in the oil marketing company SOMO. The managers in the top management within this company were targeted and the questionnaire was used as a data collection tool. The study population (109), (105) questionnaires were distributed, (94) questionnaires and (11) questionnaires were not retrieved, and the valid questionnaires had reached (91) and the analytical and descriptive approach was used for the study, the current research found to find A direct relationship and a positive effect of strategic

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Publication Date
Sat Feb 02 2019
Journal Name
Journal Of The College Of Education For Women
The Effect of Arab Environment on the Artist's Works August Renoir: The Effect of Arab Environment on the Artist's Works August Renoir
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Abstract:
This study is considerated one of many Studies above the standing of
the Islamic Arab nation which was chosen by God from other nations all over
the world . Some of these nations used to come to the Arab nation to take
whatever useful for them from the beginning of history till now . The
researcher deals in this study with a French artist who is well-know as
August Renoir . He traveled to Algeria and lived there . He was
influenced by the Islamic culture.
The study include. from chapter . chapter one deals with the framework of
programming (out line ) . Chapter two deals with the theoretical framework .
It includes five sections. Deals with the Islamic drawings(Arabesque) . section
three deals w

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Publication Date
Thu Mar 20 2025
Journal Name
Tikrit Journal Of Engineering Sciences
Effect of Different Compressor Speeds on the Energy and Exergy of an Automobile Air-Conditioner Using R134a in the Absence and Presence of a Liquid-Suction Heat Exchanger
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Refrigerant R134a has been widely utilized in automotive air conditioning systems (AACSs); R134a has a high global warming potential (GWP) of 1430 despite having zero ozone depletion potential (ODP). Coming refrigeration systems must include refrigerants with low GWP and zero ODP. The aim of this experimental study is to evaluate the thermal performance of an (AAC) with different values of compressor speeds, i.e., (1000, 1700, and 2400 rpm) and two thermal loads, i.e., (500 and 1000 Watt) with the absence and presence of liquid suction heat exchanger (LSHX) using R134a. The results showed that adding LSHX enhanced the COP cycle by 7.18%, 10.7%, and 3.09% for the first, second, and third speed, respectively, at 500 Watt, while the en

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