Drilling-induced delamination often occurs both at the entrance and the exit of the workpiece during drilling of composite material. Investigators have studied analytically and experimentally that delamination in drilling can be correlated to the thrust force of the drill. With a pre-drilled pilot hole, the delamination can be reduced significantly. Early reference reported models of drilling-i...

Objectives: This study aimed to investigate dentinal crack rate following parapulpal pin insertion in anterior primary teeth. Methods: Thirteen sound freshly extracted primary canine teeth were horizontally sectioned 1 mm above the cementoenamel junction (CEJ). All samples were thoroughly inspected to ensure that the teeth had no cracks. The teeth were then mounted in acrylic blocks...

Magnetic connections to the plunging region can exert stresses on the inner edge of an accretion disk around a black hole. We recompute the relativistic corrections to the thin-disk dynamics equations when these stresses take the form of a time-steady torque on the inner edge of the disk. The additional dissipation associated with these stresses is concentrated relatively close outside the marg...

An advanced, waveform based acoustic emission (AE) system was used to study the initiation of transverse matrix cracking in cross-ply graphite/epoxy (gr/ep) composites. The AE signals were detected with broad band, high fidelity sensors, and digitized for analysis. Plate wave propagation analysis was used to discriminate noise signals from those generated by cracks. The noise signals were confi...

Novel method for a determination of residual stresses in orthotropic composite plates based on local displacement measurements by electronic speckle-pattern interferometry is developed and verified. The values of hole diameter increments in principal residual stress directions serves as initial experimental deformation. The technique is based on analytical solution of S.G. Lekhnitsky, which des...

We report a case of spontaneous closure of stage-II macular hole. A 66 years old lady presented with decreased vision in her left eye for the last 3 months. Her vision was 6/18 in right eye and finger counting at 3 feet in left eye. Optical coherence tomography showed stage-II macular hole in left eye. There was attachment of vitreous at the edge of the hole. Minimal hole diameter was 119 μ. Ma...

Attached ultrasonic sensors can detect changes caused by crack initiation and growth if the wave path is directed through the area of critical crack formation. Dynamics of cracks opening and closing under load cause nonlinear modulation of received ultrasonic signals, enabling small cracks to be detected by stationary sensors. A methodology is presented based upon the behavior of ultrasonic sig...

We investigate the retraction of a circular thin film coated with insoluble surfactants, which is punctured at its centre. assume that surface pressure liquid–gas interface related to number density surfactants through linear equation state, characterized by single parameter: Gibbs dilation modulus. To solve governing equations and track deformation domain, we use finite element method an arbit...

This article proposes an open-source implementation of a phase-field model for brittle fracture using recently developed finite-element toolbox, Gridap in Julia. work exploits the advantages both and toolbox simulating materials. On one hand, use model, which is continuum approach uses diffuse representation sharp cracks, enables proposed to overcome such well-known drawbacks discrete predictin...