introduction: gutta-percha is the most commonly used material for root canal obturation; it has been recently manufactured with different tapers. the aim of this in vitro study was to compare microleakage of canals obturated with standard gutta-percha (0.02 taper) or the new 0.04 taper gutta-percha master cone using the cold lateral condensation technique. materials and methods: forty-four extr...

In this paper, a new analytical approach has been presented for solving strongly nonlinear oscillator problems. Iteration perturbation method leads us to high accurate solution. Two different high nonlinear examples are also presented to show the application and accuracy of the presented method. The results are compared with analytical methods and with the numerical solution using Runge-Kutta m...

Non-prismatic beams are widely employed in several engineering fields, e.g., wind turbines, rotor blades, aircraft wings, and arched bridges. While analytical solutions for variable cross-section desirable, a model describing all stress components with general variation of their under generalised loading remains an open important problem to solve. To partly address this issue, we propose soluti...

Since the first detection of the neutrino at reactors [1] and the discovery of the νμ at the Brookhaven AGS [2], accelerators and reactors have been used to provide intense beams of neutrinos. Over the last 30 years, experiments with neutrino beams have played a major role in shaping the Standard Model of particle physics as it is known today. At present, electroweak theory is more conveniently...

The aim of this in vitro study was to determine whether irrigation with apical negative pressure was more effective than traditional positive-pressure irrigation in eradicating Enterococcus faecalis from preshaped root canals. Fifty-four extracted mandibular molars were instrumented to produce either a non-tapered or tapered preparation, sterilized, inoculated with E. faecalis for 30 days, and ...

The article improves the methodological approach to finding best constructive solution for a beam made of welded steel I-beams with variable flange width. An idealized physicalmathematical model construction tapered depending on consumption and changes in geometric characteristics cross-section is described. bending strength conditions are taken as limitations. purpose research was develop an e...

In this paper, lateral stability analysis of fiber-metal laminated (FML) doubly-symmetric tapered I-beams with symmetrical lay-up for all section walls is perused by presenting a new finite element solution. Vlasov’s thin-walled beam theory utilized to consider the bending–twisting coupling effect. Based on classical lamination as well energy method, total potential derived flexural displacemen...

Introduction: As has been shown in several previous papers, biconically tapered single-mode fibres allow power transmission with a quasisinusoidal dependence on wavelength, elongation and surrounding medium refractive index. Tapered fibres have particular advantages for sensor and wavelength niters applications with a prescribed response. The biconic tapered structure is composed of a multimode...