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Effect of sodium fluoride on the properties of acrylic resin denture base material subjected to long-term water immersion
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Background: Fluoridated acrylic resin material can present more stable properties when compared with conventional one.The most widely used fluoride –containing substance added to dental resin materials is sodium fluoride (Naf). This study evaluated the effect of Naf in different concentration to the acrylic resin denture base material and its effect on tensile strength ,modules of elasticity with long –term water immersion (after 4 months immersion in de-ionized water) Materials and methods: Eighty specimens from dumbbells shaped metal pattern for tensile strength test were preparedaccording to ISO 527: 1993 plastic –Determination tensile properties ,in dimensions(60mm, 12mm, 3 ± 0.2mm) length, width and depth respectively were allocated to two groups according to water immersion there were 40 specimens before immersion and 40 specimens after water immersion for 4 months in de-ionized water(the de-ionized water was changed every day),these two groups were sub divided in to four groups according to the concentration of Naf,Naf powder were added to monomer of acrylic in concentrations of 1%,2%and 5% Naf .0% Naf(control group) ,then mixing were done with polymer according to manufacture instructions ,the conventional flasking ,packing procedure were used following that (fast cycle). For tensile strength test the measuring was done by Instron machine,the values of modulus of elasticity were obtained from tensile test . Results: Results showed that the addition of sodium fluoride to acrylic resin material werelower the tensile strength and modules of elasticity with highly significant differences p<0.01 when compared to control group regardless the concentration of Naf,But after immersion (for 4 month ) the tensile strength and modules of elasticity increased in comparison to groups before immersion (with highly significance differences p <0.01 ), highly significance differences (p <0.0)were found between groups after and before immersion in all concentrations except for tensile strength between 1%Naf and 2%Naf after immersion there was no significant differences(p>0.05), and for modules of elasticity between control and 1%Naf, 1% Naf and 2%Naf( after immersion ),there was only significant differences between them(p<0.05). Conclusions: Addition of fluoride to acrylic resin material lower the tensile strength and modules of elasticity when compared to control group regardless the concentration of Naf, But after immersion (for 4 months ) the tensile strength and modules of elasticity increased in comparison to groups before immersion (with highly significance differences p <0.01).

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Publication Date
Mon Dec 01 2014
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The Impact of Applying the Percentage of Complete Method or the Complete Contract One on the Taxation of the Long – Term Construction Contracts: بحث تطبيقي في الهيئة العامة للضرائب – قسم الشركات
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The research aims to shed light on the amount of proceeds annual tax for each of the way the contract total and percentage of completion method - see which is better - as well as the current problems arising from the application method of the contract in full in settling accounts tax - to identify problems - related to postpone settling accounts tax in accordance with the way the contract fully and determine the advantages and disadvantages of each of the methods through practical application , and then use the results as inputs to help in the decision to confirm the continuation of the GCT using a full decade in settling accounts tax for long-term construction contracts or forgo them.

Were the result of research the existence of

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Publication Date
Wed Dec 17 2025
Journal Name
Journal Of Baghdad College Of Dentistry
The surface roughness of new fluoride releasing material after using three polishing protocols and storage in artificial saliva
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Background: Prophylaxis methods are used to mechanically remove plaque and stain from tooth surfaces; such methods give rise to loss of superficial structure and roughen the surface of composites as a result of their abrasive action. This study was done to assess the effect of three polishing systems on surface texture of new anterior composites after storage in artificial saliva. Materials and methods: A total of 40 Giomer and Tetric®N-Ceram composite discs of 12 mm internal diameter and 3mm height were prepared using a specially designed cylindrical mold and were stored in artificial saliva for one month and then samples were divided into four groups according to surface treatment: Group A (control group):10 specimens received no surfa

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Publication Date
Tue Jun 01 2021
Journal Name
Iop Conference Series: Materials Science And Engineering
Effect of sodium silicate on the unconfined compressive strength of sand dune
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Abstract<p>Sand dunes are spread in multiple places in the world especially in a desert area as a result of economic development and construction processes, there was a need to study the behavior of sand dunes and make it suitable for construction. This paper aims to study the effect of adding sodium silicate on the cohesion strength of sand dune and its behavior. The results show that the cohesion strength increase as a percentage of sodium silicate increase (addition 8% Sodium silicate show the higher cohesion) and the cohesion between sand dune particles increase excepted when using 10% sodium silicate the cohesion began to decrease. However, the effect of curing time is significant and shows</p> ... Show More
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Publication Date
Wed Sep 15 2021
Journal Name
Journal Of Baghdad College Of Dentistry
The effect of contact time between alginate impression material and type III dental stone on the surface properties of stone casts
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Background: Alginate impression material is the irreversible hydrocolloid material that is widely used in dentistry. The contact time between alginate and gypsum cast could have a detrimental effect on the properties of the gypsum cast. The objective of this study is to evaluate the impact of various contact time intervals of Alginate impressions & type III dental stone on surface properties of stone cast. Materials and Methods: Time intervals tested were 1hour, 6 hours and 9 hours. Surface properties of stone cast evaluated were surface detail reproduction, hardness and roughness. Surface detail reproduction was determined using cylindrical brass test block in accordance with ISO 1563. Surface roughness was measured by profilometer

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Publication Date
Sat Jan 05 2019
Journal Name
Iraqi Journal Of Physics
Study the effect of sodium hydroxide solution on the thermal conductivity of nanocomposites
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In this research, hand lay- up technique is used to prepare samples from epoxy resin reinforced with multi- walled carbon nanotubes in different weight fractions (0, 2, 3, 4, 5) wt%. The immersion effect by sodium hydroxide solution (NaOH) at normality (0.3N) for a period of (15 days) on the thermal conductivity of nanocomposites was studied, and compared to natural condition (before immersion). The thermal conductivity of epoxy nanocomposites specimens were carried out using Lee’s disk method. The experimental results showed that thermal conductivity increased with increase weight fraction before and after immersion for all specimens, while the immersion effect leads to decrease thermal conductive values compared to thermal conductivi

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Publication Date
Mon Oct 01 2018
Journal Name
Iraqi Journal Of Physics
Effect of Sb2O3 and/or CdO nanoparticle substitution on the properties of high-TC superconducting Bi1.6-x SbxPb0.4Sr2Ca2-yCdyCu3OZ material
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High temperature superconductors materials with composition Bi1.6-xSbxPb0.4Sr2Ca2-yCdyCu3OZ (x = 0, 0.1, 0.2 and 0.3) and (y = 0.01 and 0.02), were prepared by using the chemical reaction in solid-state ways, and test influence of partial replacement of Bi and Ca with Sb and Cd respectively on the superconducting properties, all samples were sintered at the same temperature (850 oC) and for the same time (195 h). The structural analysis of the prepared samples was carried out using X-ray diffraction (XRD) measurements performed at room temperature, scanning electron microscope (SEM) and dc electrical resistivity was measured as a function of temperature. It was found that the sample prepared by partial substitution of Sb at ratio (x= 0.2

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Publication Date
Tue Aug 16 2022
Journal Name
World Journal Of Biology Pharmacy& Health Science
Long-term results of balloon pulmonary valvuloplasty in pediatric age group in surgical specialty teaching hospital/cardiac center/Hawler
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Congenital valvular pulmonary stenosis accounts for 5-10% of all congenital heart disease. Balloon pulmonary valvuloplasty is a safe and effective method in reduction of moderate to severe valvular pulmonary stenosis. This retrospective study done in Hawler surgical specialty cardiac center on pediatric patients who had pulmonary valve stenosis (with echocardiographic peak gradient 2:50mmHg) and treated by balloon pulmonary valvuloplasty. A total of 178 cases were involved, 93(52.25%) patient was male and 85 (47.75%) patients was female. 160 patient (89.89%) were treated with single balloon method 18 patient (10.11%) were managed by double balloon method technique. Follow up period of these patients range from 1 year to 10 years (mean of 5.

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Publication Date
Wed Dec 17 2025
Journal Name
Journal Of Baghdad College Of Dentistry
Teeth Displacement and Palatal Adaptation of Autoclave Cured acrylic resin with Various Palates and Investments.
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Background: The denture base inaccuracies during processing negatively influence the retention and stability of finished complete denture. The aims of this study were to evaluate teeth movement and palatal adaptation of autoclave cured denture bases and their relationship with palatal depths and investments. Materials and methods: A nightly maxillary complete dentures prepared, processed and organized to be tested as follows: 1. Processing methods: water bath and autoclave with both fast and slow cycles. 2. Palatal depth: shallow, medium and deep. 3. Investing medium: stone and silicone. For every finished denture, two measurements were done: first: teeth movement by attaching metallic reference screws on the right and left centrals, first

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Publication Date
Sat Feb 01 2014
Journal Name
Journal Of Economics And Administrative Sciences
Analysis of the Causal Relationship Long-and Short-term Between the Price of Crude Oil, the Global Price of Gold and the US. Dollar Exchange Rate
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This research aims to test the causal relationship long-and short-run between the price of gold the global crude oil price and the exchange rate of the dollar and how you can take advantage of the nature of this relationship, particularly in the Arab oil states that achieve huge surpluses, including Iraq and how to keep on the purchasing power of these surpluses or reduce the levels of risk.

The problem is that the Arab oil countries, adversely affected, as a result of that relationship, due to the fact that its role confined to the sale of crude oil only. They do not have control in the dollar, then they are not able to take advantage of its impact on the price of gold the fact that gold is effective pr

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Publication Date
Fri Mar 31 2017
Journal Name
Al-khwarizmi Engineering Journal
Experimental Study to the Effect of Natural Particles Added to Unsaturated Polyester Resin of a Polymer Matrix Composite
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Experimental investigations had been done in this study to demonstrate the effect of natural particles used as a reinforcement material to unsaturated polyester resin. The tensile test and water absorption were investigated according to (ASTM D638) and (ASTM D570), respectively. The influence of sunflower husk and pomegranate husk particles, used as a reinforcement material, on the tensile strength, Young's modulus and water absorption with different weight fraction (3%, 7% and 10%) and particle grain size (50µm, 100 µm and 150 µm), has been investigated. The water absorption of polymer composites was studied by measuring the specimen weight before and after immersion in water for one hundred days. In the experiments of tensile test,

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