The global radius of curvature of a space curve is introduced. This function is related to, but distinct from, the standard local radius of curvature and is connected to various physically appealing properties of a curve. In particular, the global radius of curvature function provides a concise characterization of the thickness of a curve, and of certain ideal shapes of knots as have been inves...

The axial length of the eye, the radius of the anterior corneal surface, and the diameter of the cornea were measured on 40 eyes of 20 New Zealand White rabbits. The ultrasonographic measurements of the axial length of the eye showed a mean value of 15.12 +/- 0.51 mm (15.33 +/- 0.50 mm in males, 14.96 +/- 0.46 mm in females). The mean corneal radius was 7.26 +/- 0.26 mm (7.18 +/- 0.9 mm in male...

This article describes and discusses a method to determine root curvature radius by using cone-beam computed tomography (CBCT). The severity of root canal curvature is essential to select instrument and instrumentation technique. The diagnosis and planning of root canal treatment have traditionally been made based on periapical radiography. However, the higher accuracy of CBCT images to identif...

This paper deals with the threshold radius that warrants the use of single restraining rail for transit and railroads. Different railways use different threshold radius from 91m to 365m to provide restraining rail. These threshold figures are probably experience driven choices. The need for restraining rail may be related to a so-called derailment alarm coefficient of 1.2 sustained over 2m leng...

Introduction: The purpose of this in-vitro study was to compare shaping ability of NiTi rotary Mtwo and FlexMaster with stainless steel hand K-Flexofile in curved root canals of extracted teeth. Materials and Methods: Mesiobuccal canals of 45 mandibular molar teeth were balanced into three groups of 15 each, with respect to the Schneider angle, canal access angle, height, dis-tance and radiu...

In order to achieve high-accuracy measurement of radius of curvature of optical sphere, ultra-high accuracy radius of curvature testing device is developed by dual-frequency laser interferometer and Fizeau interferometer based on cat’s eye and confocal method. Through analyzing the error source models of radius of curvature testing, optical configuration of the testing device has been optimized...

INTRODUCTION The purpose of this in vitro study was to introduce a new method to describe root canal curvatures and to assess the degree of curvature of human permanent mandibular teeth with curved root canals. MATERIALS AND METHODS One hundred and thirty five mesial root canals of mandibular first and second molar teeth were selected. Access cavities were prepared. After inserting a K-file s...

Atomic-scale finite element procedure for modeling of self-positioning nanostructures is developed. Our variant of the atomic-scale finite element method is based on a meshless approach and on the Tersoff interatomic potential function. The developed algorithm is used for determination of equilibrium configuration of atoms after nanostructure self-positioning. Dependency of the curvature radius...