Preferred Language
Articles
/
jbcd-136
The effect of curvature angle and rotational speed on the cyclic fatigue of three types of rotary instrument (In vitro): comparative study
...Show More Authors

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.

View Publication Preview PDF
Quick Preview PDF
Publication Date
Sat Mar 01 2008
Journal Name
Iraqi Journal Of Physics
The effect of Aluminum Oxide, Iron Oxide on the thermal conductivity of (Epoxy-Aluminum Oxide, Epoxy-Iron Oxide) Composites
...Show More Authors

Thermal conductivity for epoxy composites filled with Al2O3 and Fe2O3 are
calculated, it found that increasing the weight ratio of Al2O3 and Fe2O3 lead to
increase in the values of thermal conductivity, but the epoxy composite filled with
Fe2O3, have values of thermal conductivity less than for epoxy composite filled with
Al2O3, for the same weight ratio. Also thermal conductivity calculated for epoxy
composites by contact to every two specimens (like sandwich) content same weight
ratio of alumina-oxide and ferrite-oxide, its found that the value of thermal
conductivity lays between the values of epoxy filled Al2O3 and of epoxy filled Fe2O3

View Publication Preview PDF
Publication Date
Wed Dec 01 2010
Journal Name
Iraqi Journal Of Physics
The effect of anode temperature on the Optical characteristic of Se films prepared by direct current planar magnetron sputtering
...Show More Authors

This work describes, selenium (Se) films were deposited on clean glass substrates by dc planar magnetron sputtering technique.The dependence of sputtering deposition rate of Se film deposited on pressure and DC power has been studied. The optimum argon pressure has range (4x10-1 -8x10-2 )mbar. The optical properties such as absorption coefficient (α) was determined using the absorbance and transmission measurement from UnicoUV-2102 PC spectrophotometer, at normal incidence of light in the wavelength range of 200-850 nm. And also we calculated optical constants(refractive index (n), dielectric constant (εi,r), and Extinction coefficient (κ) for selenium films.

View Publication Preview PDF
Publication Date
Tue Aug 15 2017
Journal Name
Journal Of Immunology
The Effect of Inhibitory Signals on the Priming of Drug Hapten–Specific T Cells That Express Distinct Vβ Receptors
...Show More Authors
Abstract<p>Drug hypersensitivity involves the activation of T cells in an HLA allele–restricted manner. Because the majority of individuals who carry HLA risk alleles do not develop hypersensitivity, other parameters must control development of the drug-specific T cell response. Thus, we have used a T cell–priming assay and nitroso sulfamethoxazole (SMX-NO) as a model Ag to investigate the activation of specific TCR Vβ subtypes, the impact of programmed death -1 (PD-1), CTL-associated protein 4 (CTLA4), and T cell Ig and mucin domain protein-3 (TIM-3) coinhibitory signaling on activation of naive and memory T cells, and the ability of regulatory T cells (Tregs) to prevent responses. An expa</p> ... Show More
View Publication
Crossref (40)
Crossref
Publication Date
Tue Dec 01 2009
Journal Name
Al-khwarizmi Engineering Journal
Studying the Factors Effect on the Flowability of (ZnO – CuO/ Al2O3) Catalyst with Blending of Different Lubricants through Hopper
...Show More Authors

One of the most important problems in tablet process is to control the flow of the catalyst through the hopper; Controlling the flow can be done either by changing the size of particles or added the different lubricant (stearic acid, starch, graphite) or blending of different lubricants. The study showed that we can control (increase or decrease) on the flow of the catalyst through the hopper by blending different lubricants for the constant percentage. The flow increasing when particles size (0.6 mm) and then decrease with or without lubricants, no effect on flow when particles size lower than (0.2 mm) with use that lubricants, and good flow on (0.4 mm) when use stearic acid and starch.

View Publication Preview PDF
Publication Date
Fri Oct 21 2022
Journal Name
International Journal Of Professional Business Review
The Impact of Dumping Policy on the Food Gap of Chicken Meat in Iraq For the Period (2004-2019) - Turkish Imports Of Chicken Meat a Case Study
...Show More Authors

Purpose: As a result of the sudden and ill-considered trade openness of Iraq after 2003 to the countries of the world in general and the neighboring countries in particular, and in the absence of the necessary support for the national productive forces and the lack of effective standardization and quality control devices, this led to the exposure of most local products, especially agricultural ones, to decline and inability On the competition and thus dumping the Iraqi market, especially the agricultural products, with imported products, this study came to find out the effect that dumping has on the local production of chicken meat and the impact of that impact on the size of the food gap, and whether the results of the practica

... Show More
View Publication
Scopus (2)
Crossref (1)
Scopus Crossref
Publication Date
Thu Jun 29 2023
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Comparative Study between Different Oil Production Enhancement Scenarios in an Iraqi Tight Oil Reservoir
...Show More Authors

This paper presents a comparative study between different oil production enhancement scenarios in the Saadi tight oil reservoir located in the Halfaya Iraqi oil field. The reservoir exhibits poor petrophysical characteristics, including medium pore size, low permeability (reaching zero in some areas), and high porosity of up to 25%. Previous stimulation techniques such as acid fracturing and matrix acidizing have yielded low oil production in this reservoir. Therefore, the feasibility of hydraulic fracturing stimulation and/or horizontal well drilling scenarios was assessed to increase the production rate. While horizontal drilling and hydraulic fracturing can improve well performance, they come with high costs, often accounting for up t

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Aug 03 2025
Journal Name
Al–bahith Al–a'alami
THE RESPONSIBILITY OF INDEPENDENT IRAQI NEWSPAPERS IN PROMOTING THE VALUES OF CITIZENSHIP AND NATIONAL BELONGING IN THE SOCIETY: (An Analytical Study in the Opinion Articles in the Newspapers of Al-Sabah Al-Jadeed and Al-Mada)
...Show More Authors

The research problem stems from a chief question: “What is the nature of the responsibility that «Al-Sabah Al-Jadeed» and «Al-Mada» Newspapers have undertaken in promoting the values of citizenship and national belonging in the society? The research aims to achieve a number of goals, including: Determining the most prominent themes that were emphasized in the opinion articles in these two newspapers within the framework of the responsibility of promoting the values ​​of citizenship and national belonging in society, and revealing the most prominent topics that were discussed in opinion articles in the two sample newspapers regarding the promotion of the mentioned values. This research is a desc

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Jun 01 2014
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The Role of Organizational Change in the Development of the Insurance Service: (applied study in The National Insurance Company)
...Show More Authors

تشهد بیئة الأعمال المعاصرة جملة من التغیرات والتطورات التكنولوجیة وتزایداً في حدةالمنافسة، وأتساع الفجوة بین العاملین والإدارة ، وقدرة الإدارة على التمییز بین الموظفین، والمشاركة فيإتخاذ القرارات، الامر الذي یلقي على عاتق شركة التأمین إجراء التغییر التنظیمي لتحقیق تطور فيالخدمات التأمینیة التي تقدمها للجمهور من تنوع التغطیات التأمینیة )الوثائق( والسرعة في تسویةالتعویضات وغیرها من الانشطة التي تمارسه

... Show More
View Publication Preview PDF
Publication Date
Sun Jan 03 2016
Journal Name
Journal Of Educational And Psychological Researches
The effect of the probing questions in the collection of literature for students of the Kurdish language department in the College of Education / Ibn Rushd for the Humanities
...Show More Authors

    The goal of this research to identify the effect of the probing questions in the collection of material literature with students of the Kurdish language department, to achieve the aim of the research, the researcher has chosen a sample from the students of third stage of the Kurdish language Department, Faculty of Education / Ibn Rushd as a field for the application of experiment.The number of sample  reached (71) students divided into two groups represented two divisions of the experimental groups under study to the style of questions sounding by (35) students, and represented the other division of the control group, which studied in the way normal and by (36) students, as rewarded r

... Show More
View Publication Preview PDF
Publication Date
Sat Sep 24 2022
Journal Name
International Journal Of Biomaterials
Histological Evaluation of the Effect of Local Application of Punica granatum Seed Oil on Bone Healing
...Show More Authors

Background. Bone healing is a complex and dynamic process that represents a well-orchestrated series of biological events of cellular recruitment, proliferation, and differentiation. The use of medicinal plants in bone healing has attracted increasing interest because of their lower side effects. Punica granatum seed oil (PSO) contains high levels of phenolic compounds, promotes osteoblast function, and plays an important role in bone remodeling. A gelatin sponge (Spongostan) is a hemostatic agent that is extensively applied as scaffolds in engineering and as drug carriers in the medical field. This study aimed to evaluate the effectiveness of PSO for bone healing enhancement. Twenty adult male New Zealand rabbits, weighing an avera

... Show More
View Publication
Crossref (10)
Crossref