The masks for Loop’s triangle subdivision surface algorithm are modified resulting in surfaces with bounded curvature and the convex hull property. New edge masks are generated by a cubic polynomial mask equation whose Chebyshev coefficients are closely related to the eigenvalues of the corresponding subdivision matrix. The mask equation is found to satisfy a set of smoothness constraints on th...

introduction: this study was carried out to evaluate the technical quality of root canal treatment (rct) performed by undergraduate dental students at the islamic azad university in tehran, iran. materials and methods: four-hundred records of patients who had received rct at faculty of dentistry, between the years 2004-2006 were evaluated. for each treated tooth at least three periapical x-rays...

introduction: the purpose of the present study was to quantify and compare the amount of extruded debris from apical foramen after instrumentation of the root canal system with hand and rotary instruments. materials and methods: root canals of forty five fresh extracted single rooted human teeth with mature apexes and less than 15 degree of root curvature were instrumented in group a with stain...

In this paper, we investigate the entropy of free gravitational field for a given epoch some well-known isotropic and anisotropic cosmologies. We use definition proposed by Clifton, Ellis Tavakol, where 2-index square root 4-index Bel–Robinson tensor is taken to be energy– momentum gravity. examine whether in vicinity initial singularity, ratio energy density gravity that matter goes zero, vali...

introduction: vertical root fracture inevitably leads to tooth extraction. thus, root filling with obturating materials and sealers that can reinforce the tooth would be an ideal way to reduce fracture in root treated teeth. this study aimed to assess the fracture resistance of roots following the application of different sealers including epiphany, iroot sealer and ah-plus. methods and materia...

We introduce a family of conditions on a simplicial complex that we call local klargeness (k ≥ 6 is an integer). They are simply stated, combinatorial and easily checkable. One of our themes is that local 6-largeness is a good analogue of the nonpositive curvature: locally 6-large spaces have many properties similar to nonpositively curved ones. However, local 6-largeness neither implies nor is...

This paper shows that the continuous shearlet transform, a novel directional multiscale transform recently introduced by the authors and their collaborators, provides a precise geometrical characterization for the boundary curves of very general planar regions. This study is motivated by imaging applications, where such boundary curves represent edges of images. The shearlet approach is able to...

Given the Finsler structure (M, F) on a manifold M, a Riemannian structure (M, h) and a linear connection on M are defined. They are obtained as the " average " of the Finsler structure and the Chern connection. This linear connection is the Levi-Civita connection of the Riemannian metric h. The relation between parallel transport of the Chern connection and the Levi-Civita connection of h are ...

INTRODUCTION The introduction of nickel-titanium (NiTi) files into clinical practice has improved the quality of canal shaping, but increasing the curvature of the root canal (or the diameter of the master instrument that prepares the full working length) could result in more transportation, straightening, and aberration of the canal. Nickel-titanium instruments are significantly safer and have...