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The effect of curvature angle and rotational speed on the cyclic fatigue of three types of rotary instrument (In vitro): comparative study
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Background: The fracture of instruments within root canal during endodontic treatment is a common incidence, fracture because of fatigue through flexure occurs due to metal fatigue, this study aimed to assess the effect of curvature angle and rotational speed on the cyclic fatigue of different type of Endodontic NiTi Rotary Instruments and compare among them. Materials and method: Three types of rotary instruments with tip size 0.25: ProTaPer F2 (Densply, Malifier) Revo-S SU( 0.06 taper, MicroMega) and RaCe system (0.06 taper, FKG, Dentaire), Forty file of each instrument were used within two canals with angle of curvature (40 &60 )at two speed (250&400)RPM, twelve group were formed for all instruments(total number=120),ten file for each group. The testing canals customized within stainless steel block covered with glass face, the time to fracture recorded and the mean of cycles to fracture (MCF) detected for each instrument. Data were analyzed statistically by ANOVA, LSD and Independent T-test at 5% significant level. Result: there was a highly significant difference of curvature angle and significant difference of rotational speed on the fracture resistance of instruments. RaCe revealed the best fracture resistance followed by ProTaper then Revo-S that showed the less resistance. Conclusion: The rotary instruments more prone to fracture when used at more curvature angle and higher rotational speed, as well as the rotary instruments differ from each other according to manufacturing process, taper, cross section and other factors.

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Publication Date
Fri Jun 20 1930
Journal Name
College Of Islamic Sciences
Evidence of the prophecy of Muhammad peace be upon him and established understanding In the letters of light: Study and analysis
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Provisions and controls on the disposal of public funds between Sharia and law
Research Summary
That money is the foundation of life and one of the most important reasons for the reconstruction of the land, and God is the owner
The real value of this money, God has borrowed some individuals on public money, and people
They are charged with preserving it, since it is beneficial to them all, without anyone taking it
To himself, and the guardian is charged by God to protect this money and aggression
Because of its power, authority, various organs and public servants of the province
Upon him; Because the assault on public money by employees and others in the organs of the state
And exploitation of their jobs and this

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Publication Date
Wed Jul 01 2020
Journal Name
Journal Of Engineering
An Analytical Solution for the Maximum Tensile Stress and Stress Concentration Factor Investigations for Standard, Asymmetric fillets, Asymmetric Pressure Angle and Profile Shifted Helical and Spur Gears
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This research introduces a developed analytical method to determine the nominal and maximum tensile stress and investigate the stress concentration factor. The required tooth fillets parametric equations and gears dimensions have been reformulated to take into account the asymmetric fillets radiuses, asymmetric pressure angle, and profile shifting non-standard modifications. An analytical technique has been developed for the determination of tooth weakest section location for standard, asymmetric fillet radiuses, asymmetric pressure angle and profile shifted involute helical and spur gears. Moreover, an analytical equation to evaluate gear tooth-loading angle at any radial distance on the involute profile of spur and hel

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Publication Date
Wed Jan 08 2025
Journal Name
Egyptian Journal Of Veterinary Sciences
Histological and Histochemical Study of the Esophagus Before and After Crop in the Guinea Fowl (Numida meleagris)
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Publication Date
Sat Mar 30 2024
Journal Name
مجلة نسق
Education Skills and Their Role in the Health and Psychological Development of the Child An Anthropological Study
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The study highlighted the transformation of value systems and educational patterns between past and present, especially with the introduction of modern variables and means, such as mobile phones, the internet, social media, and others. These factors have contributed both positively and negatively to the study. The study highlights the integral role of the school in collaboration with the family in guiding and educating children. It also emphasizes the active role of the school in developing students' abilities and skills, either attracting them to school or vice versa. This includes an examination of the essential skills required in education and their role in achieving a state of psychological well-being and systematically developing child

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Publication Date
Thu Sep 15 2022
Journal Name
Alustath Journal For Human And Social Sciences
The Impact of Mind and Informational Strategy on the ‎Achievement of the Second Intermediate Students in the Grammar ‎of Arabic Language
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The aim of the current research is to recognizing the impact of mind and informational strategy on the achievement with the second intermediate students in the grammar of arabic language, the researcher used a partial-set experimental design and intentionally selected a sample out of the second intermediate class from (AL- Markazya Intermediate school) in the district of Hilla, affiliated which belongs to General Directorate of Babylon Education in the year (2020-2021) for applying the experiment. The sample was composed of (50) students, (25) ones for each group, the experimental group and normal one. The researcher balanced between the two groups in various changes including: (the chronological age counted by months, the academic achie

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Publication Date
Mon Aug 01 2011
Journal Name
Journal Of Engineering
EFFECT OF THE SAND MOULD ADDITIVES ON SOME MECHANICAL PROPERTIES OF CARBON STEEL CK45 CASTS
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The research targets study of influence of additives on sand mold’s properties and, consequently, on
that of carbon steel CK45 casts produced by three molds. Three materials were selected for addition
to sand mix at weight percentages. These are sodium carbonates, glycerin and oat flour. Sand molds
of studied properties were produced to get casts from such molds. The required tests were made to
find the best additives with respect to properties of cast. ANSYS software is used to demonstrate
the stresses distribution of each produced materials. It is shown that the mechanical properties of
casts produced is improved highly with sodium carbonates and is less with oat flour and it is seem a
few with glycerin additives

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Publication Date
Fri Jun 01 2012
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Effect of risk selection policy for life insurance on the prodectivity of iraqi insurance company
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The life insurance companies need a sound system to use it in selecting Insurable risks so they can avoid or reduce possible losses that may be insured to a minimum levels , But the application within IRAQI INSURANCE  COMPANY reflects that it still depends on a traditional ways in the procedures used to select that risks .

                 This  research represents an attempt to put acceptable suggestions about developing a system for selecting insurable risks which used now by iraqi insurance company by recognizing the risks of life insurance , determining kinds of risks which can difined as normal and upnormal risks , rectification of the

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Publication Date
Wed Dec 14 2016
Journal Name
Journal Of Baghdad College Of Dentistry
The Effect of Silver-Zinc Zeolite Incorporation on Some Properties of Condensation Silicone Impression Material
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Background: elastomeric impression materials are indicated when a high degree of accuracy is required, due to their excellent properties like details reproduction, dimensional stability and tear strength but with main two disadvantages those are their hydrophilicity as well as the absence of antibacterial activity. This study aimed to evaluate the effect of incorporation of 0.5% wt Ag-Zn zeolite into condensation silicone through the following tests; setting time, dimensional stability, reproduction of details, wettability, and hardness . Materials and methods: one hundred specimens were constructed of condensation silicone, divided into two groups for the first 50 specimens one0.5% by wt Ag -Zn zeolite was added, keeping the other fifty sp

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Publication Date
Mon Sep 20 2021
Journal Name
Key Engineering Materials
The Effect of Quantum Confinement on Optical Properties of CdSe Quantum Dots at Room Temperature
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CdSe quantum dots possess a tuning energy gap which can control gap values according to the size of the quantum dots, this is made the material able to absorb the wavelengths within visible light. A simple model is provided for the absorption coefficient, optical properties, and optical constants for CdSe quantum dots from the size 10nm to 1nm with the range of visible region between (300-730) nm at room temperature. It turns out that there is an absorption threshold for each wavelength, CdSe quantum dots begin to absorb the visible spectrum of 1.4 nm at room temperature for a wavelength of 300 nm. It has been noted that; when the wavelength is increased, the absorption threshold also increases. This applies to the optical propertie

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Publication Date
Mon Aug 01 2011
Journal Name
Journal Of Engineering
EFFECT OF STEEL FIBERS ADDITION ON THE BEHAVIOR OF HIGH STRENGTH CONCRETE CIRCULAR SHORT COLUMNS
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loaded reinforced concrete circular short columns. An experimental investigation into the behavior
of 24 short reinforced concrete columns with and without steel fibers was carried out. The columns
had a circular section (200 mm diameter and 900 mm long). Test variables include concrete
strength, spacing of spiral reinforcement, and inclusion of steel fibers. The axial stress and axial
strains were obtained and used to evaluate the effects of the presence of steel fibers. It was found
that the addition of steel fibers slightly improves the load carrying capacity of the tested columns
whereas it significantly enhances the ductility of these specimens. Test results also indicated that for
the same confinement parameter

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