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.
The objective of this study is to highlight the skills of office managers and it's impact on the effectiveness of time management in the institutes and faculties of middle technical university and a group of cognitive and practical aims. The managers skills forms mthe modern trend and the main source to provide organizations with highly skilled managers with distinctive performance and because of the sharp changes in the environment which today's organizations works in it , business organizations generally and managers especially realise the importance of time management and it's role in achieving competitive advantage . The problem of this study raised from this point which reflect the extent of departments managers realisation
... Show MoreSummary of the discussion of the jurisprudential aspects of Imam Abu Al-Fayyad Al-Basri, and their impact on the Shafi’i school, on the provisions of transactions, personal status, janaabah, limits, and others
Praise be to God, Lord of the Worlds, and prayers and peace be upon the Master of the Messengers, our master Muhammad, and upon his pure family, and his ignorant and ignorant companions, and those who followed them in goodness until the Day of Judgment.
Then:
The many jurisprudential aspects that the Shafi’i imams said are of great importance, because these aspects are nothing but the opinions of venerable jurists who have reached a high degree of knowledge unti
... Show MoreThis research was based on two pillars. The first is a comparison between of research done and the result of a particular variable of research indebendently in the united state, and second, knowledge and determine the effect of managers practices on the contributions of personnel. The manager and staff are considered to be the most important elements in the organization and all of them have a duty towards the others which governed by the relationship rules of procedure of the ministry researched, on the one hand and the interests of the organization and hence employees , whether executives or employees within management formations that the availability of an acceptable level of good pract
... Show MoreThe objective of the study is to study how to employ performance evaluation in achieving organizational integrity and the impact of performance evaluation on achieving organizational integrity. In light of this, the following questions were raised:
Are the dimensions of organizational integrity available in the field in question?
In order to answer the research questions, a questionnaire questionnaire was distributed to the sample of 30 members of the teaching staff at the Technical Institute in Mosul. The three-dimensional Lycert scale was used. The statistical methods were used, ie, the frequency distribution, the computational circles, the standard deviations, Pearson), simple
... Show MoreA high-performance liquid chromatography method was employed for the quantitative determination of ascorbic acid (AA) which called vitamin C in three types of Iraqi citrus (orange mandarin and aurantium ) and to establish this goal , evaluation of ascorbic acid degradation is so important due to its significant criticality when exposure to ordinary atmospheric conditions. The chromatographic analysis of AA was carried out after their sequential elution with KH2PO4 ( as mobile phase) by reverse-phase HPLC technique with C8 column and UV detection at 214 nm. .Bad resolutions was appeared clearly for C8 column , so another alternative condition were carried out to improve the resolution by replacement of C8 by C18 column .Statistical treat
... Show MoreThis research aims to identify the nutritional status of the individual's relationship to malnutrition using anthropometric measurements such as weight, height and impact on the values ??of the blood study sample included 200 male and 200 female of the inhabitants of the cities of Baghdad and Baquba reviewers Central Mahtbrat
The purpose of this study is to examine the dimensions of strategic intent (SI; see Appendix 1) according to the Hamel and Prahalad model as a building for the future, relying on today’s knowledge-based and proactive strategic directions of management as long-term and deep-perspective creative directions, objective vision and rational analysis, integrative in work, survival structure and comprehensiveness in perception.
The quantitative approach was used based on research, detection and proof, as data were collected from leader
The nuclear structure of 38Ar, 59Co, 124Sn, 146Nd, 153Eu and 203Tl target nuclei used in technology for nuclear batteries have been investigation, in order that, these nuclei are very interesting for radioisotope thermo-electric generator (RTG) space studies and for betavoltaic battery microelectronic systems. The single particle radial density distribution, the corresponding root mean square radii (rms), neutron skin thicknesses and binding energies have been investigated within the framework of Hartree-Fock Approximation with Skyrme interaction. The bremsstrahlung spectrums produced by absorption of beta particles in betavoltaic process and backscattered p
... Show MoreThe present study discusses the names of the Day of Resurrection in Uri Rubin’s translations of the Holy Qur’an. To identify the translation difficulties and complications and to find out the Hebrew equivalence, the study, through the application of a comparative analytical approach, aims at analyzing the linguistic structures of Day of Resurrection names cited in the Holy Qur’an. Heavenly religions are rich with distinct and unique terms that distinguish and reflect their specificity of other religions; something requires a great accuracy in the translation of such terminology. By investigating selected examples of the names of the Day of Resurrection in Arabic and Hebrew, the present study sheds light on the morphological and semant
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