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 fo

Natural bitumen (NB) is a highly precious material and has drawn increasing attention due to its unique properties, especially since it is available in large quantities and has been used in limited fields. In this research, the exploitation of NB from sulfur springs as an alternative energy resource in the production of asphalt pavement is evaluated. It can be concluded from the experimental results that the chemical composition and surface morphology of NB samples are different from those of base asphalt. Besides, the rheological properties of virgin NB are not sufficient for paving work. To overcome this obstacle, NB from five different springs is modified with limestone filler (LSF) to enhance its properties. LSF is a natural material an

The Sunnah of the Prophet has a great impact in building human behavior, and the formation of Islamic thought, has worked to spread science in all of Egypt, as it carried to the people of the eternal prophecy of the love of science, it was a source of knowledge and civilization. It is a generous source, a rich source of the Islamic nation, always tender, and renewed benefit, which is not only a source of legislation and language but is a source of guidance for thought and guidance of behavior, and the Hadith The importance is obvious In the integration of Islam, and show aspects of human integration in the personality of Mustafa , and the Muslims are interested in talking - collected and codification -, and made the effort of the cent

Iraqi calcium bentonite was activated via acidification to study its structural and electrical properties. The elemental analysis of treated bentonite was determined by using X-ray fluorescence while the unit crystal structure was studied through X-ray diffraction showing disappearance of some fundamental reflections due to the treatment processes. The surface morphology, on the other hand, was studied thoroughly by Scanning Electron microscopy SEM and Atomic Force Microscope AFM showing some fragments of montmorillonite sheets. Furthermore, the electrical properties of bentonite were studied including: The dielectric permittivity, conductivity, tangent loss factor, and impedance with range of frequency (0.1-1000 KHz) at different temperatu

Lithium–Manganese ferrites having the chemical formula (Li0.5-0.5x Mnx Fe2.5-0.5x O4), (0 ≤ x ≤ 1) were prepared by double sintering powder processing. The density of the ferrite increased with Mn content while the porosity was noticed to decrease. The dielectric constant was found to increase at high frequencies more rapidly than the low ones. The dielectric constant found to decrease with Mn content. The decrease in loss factor with frequency agreed with Deby’s type relaxation process. A maximum of dielectric loss factor was observed when the hopping frequency is equal to the external electric field frequency. Manganese substitution reduced the dielectric loss in ferrite. The variation of tanδ with frequency shows a similar na