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Evaluation of the effect of preheating on micro leakage of Class II composites Restoration (A comparative in vitro study)
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Background: The aim of this in vitro study was to evaluate and compare the effect of preheating microleakage among three different filler size composites which include Filtektm Z250 micro hybrid, Z250xt Nano hybrid and nanocomposite Z350xt.  in Class II cavity preparation .

Materials and methods: sixty maxillary first premolars were prepared with class II cavities. Samples were divided into three groups according to material used    group A (FiltekZ250 micro hybrid). Group B(Z250xt Nano hybrid). Group C (nanocomposite Z350xt)and each group divided into two subgroups of ten teeth according to temperature of  composite: Group A1 Teeth are restored by composite at  room temperature(24±1ËšC), A2 Teeth are restored by same composite at preheated temperature(54±1ËšC). After 24 hrs. immersion in 2% in methylene blue, samples were sectioned and micro leakage was estimated.

Results: The greater scores of micro leakage mentioned in Group A( Z250 micro hybrid) in cervical margin while in Group B( Z250xt Nano hybrid) and  Group C (Z350xt nanocomposite) have least score of micro leakage especially in occlusal margin.

Conclusions: The scores of micro leakage for all groups varied with different material, margin and temperature. Generally, preheating decreased micro leakage  in all groups of composites ,but Preheating decreased micro leakage effectively in Z250 micro hybrid more than Z250xt Nano hybrid and Z350xt nanocomposite micro leakage .

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Publication Date
Sun Dec 01 2024
Journal Name
Al-qadisiyah Journal For Agriculture Sciences
Effect of Holes Diameter and Speed of Die on the Performance of Machine and Feed Pellet Quality
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The aim of this study to evaluate the effects of die holes diameter and speed of die on the performance of machine and feed pellet quality. Machine productivity (Kg.h-1), consumed power (kW), pellet durability (%) and pellet bulk density (g.cm-3) was studied. The study factors consisted of three diameter of die holes (3, 4, and 5 mm), and three speeds die (280, 300, and 320 rpm). Results showed with increasing of die holes diameter from 3 to 4 and to 5 mm give a significant increase in machine productivity, while consumed power, pellet durability and pellet bulk density a significant decreased. By increasing the die speed, from 280 to 300 then to 320 rpm, the machine productivity increased significantly, while consumed power, pellet durabil

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Publication Date
Sat Jun 15 2013
Journal Name
Journal Of Baghdad College Of Dentistry
The effect of SOLO and sodium hypochlorite disinfectant on some properties of different types of dental stone
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Background: Dental casts come into direct contact with impression materials and other items that are contaminated by saliva and blood from a patient's mouth, leaving the casts susceptible to cross-contamination. The disinfectant solutions of the impression materials cause various adverse reactions. Therefore, disinfection of dental casts may be effective in preventing cross infection. This study was carried out to evaluate the surface hardness, dimensional accuracy, reproduction of details and surface porosity of type III, type IV and type IV extra hard dental stone after immersion in and spray by using SOLO and Sodium hypochlorite disinfectant solutions. Materials and methods: 240 Stone samples were prepared in rubber rings, A total of 60

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Publication Date
Fri Apr 12 2019
Journal Name
Journal Of Economics And Administrative Sciences
Core competencies and Their Role in Enhancing Organizational flexibility: An Analytical Study of the Views of a Sample of Employees in Presidency University of Mosul
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Abstract

The study aims to identify the levels of core competencies dimensions and types of organizational flexibility in the investigated organization, as well as to determine the nature of the relationship and the impact of core competencies dimensions with the process of organizational flexibility. Thus, a number of research questions were presented to express the research problem as follows:

  • What is the level of the investigated individuals' awareness to core competencies and organizational flexibility across their dimensions and types in the investigated organization?
  • To what extent are core competencies and organizational flexibility available in the Organiz

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Publication Date
Wed Mar 10 2021
Journal Name
Baghdad Science Journal
THE EFFECT OF CHEMICAL AND BIOLOGICAL TREATMENTS ON IMPROVING THE NUTRITIVE VALUE OF CORN COBS AND WILD REED
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This study was conducted in Animal Resources Department , College of Agriculture to estimate the effect of chemical and biological treatments to improve the nutritive value of poor quality roughages ( corn cobs and wild reed ) . The feeds were treated chemically with 4% NaoH solution ,whereas Aspergillus niger was used to ferment corn cobs and wild reed samples . The chemical analysis showed that protein percentages of corn cobs and wild reed was increased significantly (P<0.05) from 6.05% to 10.51% and 17.70% and from 3.10 %to 6.50% and 9.96% for both chemical and biological treatments respectively. The crude fiber percentages decreased significantly (P<0.05) from 29.19% and 26.10% to 23.60% and 20.10% for chemical treatment and was 20

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Publication Date
Sat Dec 05 2020
Journal Name
Iop Conference Series: Materials Science And Engineering, Volume 1067
The effect of cyclic loading on the nonlinear response of structural concrete members with arbitrary cross-sectional shapes
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Publication Date
Sun Apr 22 2018
Journal Name
Al-nahrain Journal For Engineering Sciences
Numerical Analysis of the Effect of Scanning Speed on the Temperature Field Distribution for Laser Heat Treatment Applications
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One of the unique properties of laser heating applications is its powerful ability for precise pouring of energy on the needed regions in heat treatment applications. The rapid rise in temperature at the irradiated region produces a high temperature gradient, which contributes in phase metallurgical changes, inside the volume of the irradiated material. This article presents a comprehensive numerical work for a model based on experimentally laser heated AISI 1110 steel samples. The numerical investigation is based on the finite element method (FEM) taking in consideration the temperature dependent material properties to predict the temperature distribution within the irradiated material volume. The finite element analysis (FEA) was carried

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Publication Date
Mon May 28 2018
Journal Name
Biology
The Effect of Overexpressed DdRabS on Development, Cell Death, Vesicular Trafficking, and the Secretion of Lysosomal Glycosidase Enzymes
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Publication Date
Sat Jan 01 2022
Journal Name
Communications In Mathematical Biology And Neuroscience
The effect of fear on the dynamics of two competing prey-one predator system involving intra-specific competition
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Publication Date
Mon Feb 01 2016
Journal Name
Journal Of Engineering
The Effect of Cement and Admixture Types on the Resistance of High Performance Concrete to Internal Sulphate Attack
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This work is concerned with the study of the effect of cement types, particularly OPC and SRPC, which are the main cement types manufactured in Iraq. In addition, study the effect of mineral admixtures, which are HRM and SF on the resistance of high performance concrete (HPC) to internal sulphate attack. The HRM is used at (10%) and SF is used at (8 and 10)% as a partial replacement by weight of cement for both types. The percentages of sulphate investigated are (1,2 and 3)% by adding natural gypsum as a partial replacement by weight of fine aggregate. The tests carried out in this work are: compressive strength, flexural strength, ultrasonic pulse velocity, and density at the age of 7, 28, 90 and 120 days.

The r

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Publication Date
Wed Dec 27 2017
Journal Name
Al-khwarizmi Engineering Journal
The Effect of Oil and Filer Contents on the Porosity of Lead Acid Battery Separators Produced From Polyethylene
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                In this investigation a high density polyethylene (HDPE) was used as a substitute to polyvinylchloride in the production of lead acid battery separators. This has been achieved by preparing mixtures of different percentages of the feed materials which include a high density polyethylene (HDPE) locally produced, filler materials such as silica and oils such as dioctylphthalate (DOP) or paraffin which were added to the mixture to improve the final properties of the separator. The materials were compounded by two roll-mills under the same conditions. The following parameters are involved:           &nb

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