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.
In this work, the plasma parameters (electron temperature and
electron density) were determined by optical emission spectroscopy
(OES) produced by the RF magnetron Zn plasma produced by
oxygen and argon at different working pressure. The spectrum was
recorded by spectrometer supplied with CCD camera, computer and
NIST standard of neutral and ionic lines of Zn, argon and oxygen.
The effects of pressure on plasma parameters were studied and a
comparison between the two gasses was made.
In this research, rabbit femurs were implanted with CP Ti screws coated with a combination of CaCO3 and nanohydroxyapatite, and the effect on osseointegration was assessed using histological and histomorphometric examination at 2 and 6 weeks. CaCO3 and nanohydroxyapatite were combined with the EPD to coat the surfaces of the CP Ti screws. The femurs of five male rabbits were implanted with coated and uncoated implant screws. Healing time was divided into two groups (2 and 6 weeks). After 2 and 6 weeks of implantation, the histological examination revealed an increase in the growth of bone cells for coated screws, and the histomorphometric analysis revealed an increase in the percentage of ne
... Show MoreThis paper describes a new finishing process using magnetic abrasives were newly made to finish effectively brass plate that is very difficult to be polished by the conventional machining processes. Taguchi experimental design method was adopted for evaluating the effect of the process parameters on the improvement of the surface roughness and hardness by the magnetic abrasive polishing. The process parameters are: the applied current to the inductor, the working gap between the workpiece and the inductor, the rotational speed and the volume of powder. The analysis of variance(ANOVA) was analyzed using statistical software to identify the optimal conditions for better surface roughness and hardness. Regressions models based on statistical m
... Show MoreThis research aimd to analyze the role of strategic entreprenenial on according to the external performance of a sample of Iraqi private banks, namely, (National Islamic Bank, Iraqi Ahli Bank, Baghdad Bank , Middle East Iraqi Investment Bank) has launched research in fundamental problem stems from the question seeking his response to the characterization of the problem which is improve banking performance through strategic entreprenenial and to achieve the goal of the research was to prepare a questionnaire included a number of questions about the independent research and approved variables accounting for the independent variable strategic entreprenenial and included four dimensions (entreprenenial culture), entreprenenial leader
... Show MoreThis research after financial ratios in the detection of fraud to the financial statements published which enables specialists from the work of their studies and their conclusions to obtain the information they seek on the activities of the entity. Has provided researchers what these relics They then field study to test the validity and sincerity of the findings of the suggestions that have been upheld the need to study all financial ratios extracted in general, organized and used in decision-making processes necessary administrative.And that the financial management attention more financial analysis and extraction of financial ratios and compare them with industry standards taken from historical norms
There are many techniques that can be used to estimate the spray quality traits such as the spray coverage, droplet density, droplet count, and droplet diameter. One of the most common techniques is to use water sensitive papers (WSP) as a spray collector on field conditions and analyzing them using several software. However, possible merger of some droplets could occur after they deposit on WSP, and this could affect the accuracy of the results. In this research, image processing technique was used for better estimation of the spray traits, and to overcome the problem of droplet merger. The droplets were classified as non-merged and merged droplets based on their roundness, then the merged droplets were separated based on the average non-m
... Show MoreThe present research tackles a number of historical facts and incidents with a purely legal dimension in an important stage in the contemporary history of Iraq, especially the era of the British occupation. This resulted in innumerable social, political and legal problems, particularily the judicial legislation problems in Iraq. These legislations included a set of civil laws and in force governmental procedures that will be discussed historically by examining documents issued by the Ministries of Justice and Interior Affairs in the governments of monarchy for the period from 1921-to-1958. The data of the present paper relied on the Iraqi Library and Archives, (hence DKW). The study adopted the narrative historical methodology when inves
... Show MoreBackground: The beliefs of pharmacy students in their curriculum may be critical to the success of medical education and the development of global health competences. Objective: To assess the beliefs, attitudes, and obstacles of PharmD students at the College of Pharmacy, University of Baghdad, during their first year in the newly adopted PharmD program. Method: In-depth qualitative interviews were conducted using flexible probing approaches. A sample of fourth-year PharmD students from the University of Baghdad's College of Pharmacy was selected using a purposive sampling method. The gathered data was analyzed using a thematic content analysis approach. Results: 40% of participants applied for the program because they believed it w
... Show MoreAbstract
The purpose of the present paper is to light on the relationship between jobs design, analysis and its reflections on reinforcing workers' vocational adjustment. The present paper aims to accomplish cognitive and applied goals, top of which, test of functional analysis ability to have effect upon workers' vocational adjustment via job design directly and indirectly owning to the virtual factor practiced by these practices on the sought organization. The problem of the present paper comes with many, the most important is the of how to bolster and back up worker's technical adjustment through good and accurate design for the job.
Based on this problem and goals as to expla
... Show MoreThis study aims to investigate the relationship between corporate governance (CG) and audit quality (AQ) in the adequacy of the value relevance of accounting information (VRAI). The study sample included Iraqi firms listed on the Iraqi Stock Exchange (ISE) from 2010 to 2022. Nineteen firms were a research sample selected from 44 firms listed on the ISE. They chose to use the model (Ohlson, 1995) in measuring VRAI, which is based on measuring the absolute value of the level of value relevance to earnings per share (EPS) the absolute value of the book value suitability level VRAI. CG was measured through five factors: board size, gender of board members, independence of the board from the chief executive officer (CEO), ownership perce
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