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The impact of various staining substances and immersion time on the stainability of bonded sapphire brackets with three kinds of light cure orthodontic adhesives (An in-vitro study)
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Background: The need of the patient for a more reasonable esthetic orthodontic intervention has risen nowadays. Thus, orthodontists make use of esthetic orthodontic materials like brackets, ligature elastics, and arch wires. The esthetic brackets come as different forms of materials, such as ceramic brackets, which have their stainability remaining as the most important consideration for the patients and the orthodontists. This study aimed to compare the staining effects of various staining materials, including black tea, cigarette smoke and Pepsi, as well as the time effect on the color stability of sapphire ceramic brackets bonded with three kinds of light cure orthodontic adhesives: Transbond, Resilience and Enlight. Materials and Methods: Three hundred sixty sapphire brackets were utilized and divided into three different groups (120 brackets per group) based on the type of bonding material. Each group was further subdivided into four subgroups (30 brackets each) based on the media in which the brackets were fully immersed, including distilled water, black tea, cigarette smoke and Pepsi. Moreover, each of these subgroups were further subdivided, based on the time of immersion relative to each media, into 3 different smaller subgroups (10 brackets each): one day, 7 days and 14 days with incubation at 37°C. A UV-visible type of spectrophotometer was utilized in order to perform a light absorption test. ANOVA and post hoc LSD tests were used for comparison. Results: The smoke of cigarette appeared to be the highest potent staining type among the tested materials followed by Pepsi and tea. The staining effects of all kinds of staining materials in relation to the bonded brackets color with all adhesive types were raised with increased time of immersion. Conclusion: The patient’s cooperation and habits should be taken into consideration when using sapphire orthodontic brackets. In addition, the patients should be instructed to decrease the consumption of staining beverages. Keywords: Stainability, staining materials, sapphire brackets.

 

 

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Publication Date
Sat Jun 30 2007
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Corrosion Inhibition of Carbon Steel under Two Phase Flow (Water-Petroleum) Simulated by Turbulently Agitated System
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The corrosion of carbon steel in single phase (water with 0.1N NaCl ) and two immiscible phases (kerosene-water) using turbulently agitated system is investigated. The experiments are carried out for Reynolds number (Re) range of 38000 to 95000 corresponding  to rotational velocities from 600 to 1400 rpm using circular disk turbine agitator at 40 0C. In two-phase system test runs are carried out in aqueous phase (water) concentrations of 1 % vol., 5 % vol., 8% vol., and 16% vol. mixed with kerosene at various Re. The effect of Reynolds number (Re), percent of dispersed phase, dispersed drops diameter, and number of drops per unit volume on the corrosion rate is investigated and discussed. Test runs are carried out using two types of

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Publication Date
Thu Dec 01 2011
Journal Name
Journal Of Engineering
OPTIMAL DESIGN OF MODERATE THICK LAMINATED COMPOSITE PLATES UNDER STATIC CONSTRAINTS USING REAL CODING GENETIC ALGORITHM
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The objective of the current research is to find an optimum design of hybrid laminated moderate thick composite plates with static constraint. The stacking sequence and ply angle is required for optimization to achieve minimum deflection for hybrid laminated composite plates consist of glass and carbon long fibers reinforcements that impeded in epoxy matrix with known plates dimension and loading. The analysis of plate is by adopting the first-order shear deformation theory and using Navier's solution with Genetic Algorithm to approach the current objective. A program written with MATLAB to find best stacking sequence and ply angles that give minimum deflection, and the results comparing with ANSYS.

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Publication Date
Wed May 10 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Adsorption of Thymol From Aqueous Solution Using Granulated Surfactant Initiated Modified Bentonite via Packed Column Method
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    The adsorption study of thymol, was carried out at (25±0.1) °C, using granulated surfactant modified Iraqi Na – montmorillonite clay (initiated modified bentonite); in a down-flow packed column, the modified mineral was characterized by FT-IR spectroscopy.  A linear calibration graph for thymol was obtained, which obey Beer's law in the concentration range of 5-50 mg/L at 274 nm against reagent blank. Single-factor-at-a-time approach; showed that the equilibrium time required for complete adsorption was 45 minute with flow rate (4.0drop/ mint). The adsorption of thymol increased with rising pH of the adsorbate solution, increase of solute uptake when  the initial adsor

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Publication Date
Fri May 01 2015
Journal Name
Journal Of Engineering
Use of non-Conventional Material to Remove Cu+2 ions from Aqueous Solutions using Chemical Coagulation
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Coagulation - flocculation are basic chemical engineering method in the treatment of metal-bearing industrial wastewater because it removes colloidal particles, some soluble compounds and very fine solid suspensions initially present in the wastewater by destabilization and formation of flocs. This research was conducted to study the feasibility of using natural coagulant such as okra and mallow and chemical coagulant such as alum for removing Cu and increase the removal efficiency and reduce the turbidity of treated water. Fourier transform Infrared (FTIR) was carried out for okra and mallow before and after coagulant to determine their type of functional groups. Carbonyl and hydroxyl functional groups on the surface of

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Publication Date
Wed Mar 18 2020
Journal Name
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Differentiation of Adipose-Derived Mesenchymal Stem Cells into Neuron-Like Cells induced by using β-mercaptoethanol
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Background: Adipose derived-mesenchymal stem cells have been used as an alternative to bone marrow cells in this study. Objective: We investigated the in vitro isolation, identification, and differentiation of stem cells into neuron cells, in order to produce neuron cells via cell culture, which would be useful in nerve injury treatment. Method: Mouse adipose mesenchymal stem cells were dissected from the abdominal subcutaneous region. Neural differentiation was induced using β-mercaptoethanol. This study included two different neural stage markers, i.e. nestin and neurofilament light-chain, to detect immature and mature neurons, respectively. Results: The immunocytochemistry results showed that the use of β-mercaptoethanol resulted in

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Publication Date
Wed Jun 19 2019
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Disclosure of deferred taxes according to IAS-12: بحث تطبيقي في الهيئة العامة للضرائب قسم الشركات
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The research aims to clarify the importance of adoption of International Accounting  Standard No. (12) "Income Taxes" as a tool for the measurement and disclosure of income taxes in the financial statements، and how to deal with the differences that arise as a result of difference in net profit accounting for net tax profit ،The problem of the research focused on the disparity between the income tax estimate in Iraq in accordance with the accounting standards and financial reporting and assessment of income tax in accordance with the tax laws and legislation, this discrepancy has led to the emergence of differences between accounting profit and tax profit (temporary differences and permanent differences) and these differences of w

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Publication Date
Fri Jan 31 2020
Journal Name
Iraqi Geological Journal
ESTIMATION OF SHEAR WAVE VELOCITY FROM WIRELINE LOGS DATA FOR AMARA OILFIELD, MISHRIF FORMATION, SOUTHERN IRAQ
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Shear wave velocity is an important feature in the seismic exploration that could be utilized in reservoir development strategy and characterization. Its vital applications in petrophysics, seismic, and geomechanics to predict rock elastic and inelastic properties are essential elements of good stability and fracturing orientation, identification of matrix mineral and gas-bearing formations. However, the shear wave velocity that is usually obtained from core analysis which is an expensive and time-consuming process and dipole sonic imager tool is not commonly available in all wells. In this study, a statistical method is presented to predict shear wave velocity from wireline log data. The model concentrated to predict shear wave velocity fr

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Publication Date
Thu Nov 02 2023
Journal Name
Journal Of Engineering
Constructing a Sustainable Roller Compacted Concrete Using Waste Demolished Material as Replacement of Cement: A Review
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Roller Compacted Concrete is a type of concrete that is environmentally friendly and more economical than traditional concrete. Roller Compacted Concrete is typically used for heavy-duty and specialist constructions, such as hydraulic structures and pavements, because of its coarse surface. The main difference between RCC and conventional concrete mixtures is that RCC has a more significant proportion of fine aggregates that allow compaction and tight packing. In recent years, it has been estimated that several million tons of waste demolished material (WDM) produced each year are directed to landfills worldwide without being recycled for disposal. This review aimed to study the literature about creating a Roller-Comp

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Publication Date
Wed Dec 29 2021
Journal Name
Journal Of The College Of Education For Women
A Speech Acts Analysis of English COVID-19 News Headlines: مثنى نجيب المرسومي, جمعة قادر حسين
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News headlines are key elements in spreading news. They are unique texts written in a special language which enables readers understand the overall nature and importance of the topic. However, this special language causes difficulty for readers in understanding the headline. To illuminate this difficulty, it is argued that a pragmatic analysis from a speech act theory perspective is a plausible tool for a headline analysis. The main objective of the study is to pragmatically analyze the most frequently employed types of speech acts in the news headlines covering COVID-19 in Aljazeera English website. To this end, Bach and Harnish's (1979) Taxonomy of Speech Acts has been adopted to analyze the data. Thirty headlines have been collected f

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Publication Date
Tue Dec 22 2020
Journal Name
Lecture Notes In Civil Engineering
Geometric Nonlinear Synthetic Earthquake Analysis of Base Isolated Tall Steel Buildings Under Site-Specific Seismic Loading
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