INTRODUCTION Irrigation dynamics and antibacterial activity determine the efficacy of root canal disinfection. Sonic or ultrasonic agitation of irrigants is expected to improve irrigation dynamics. This study examined the effects of microbubble emulsion (ME) combined with sonic or ultrasonic agitation on irrigation dynamics and reduction of biofilm bacteria within root canal models. METHODS T...

Hedgehog genes have been implicated in inductive signaling during development in a variety of organisms. A key element of the hedgehog signaling system is encoded by the gene patched. In Drosophila hedgehog regulates gene expression by antagonizing the action of patched. In addition, patched is itself a transcriptional target of hedgehog signaling. We have isolated a chicken patched homolog and...

Sample return and in-situ sampling and analysis is one of the major objectives of future NASA exploration missions. Existing drilling techniques are limited by the need for large axial forces, holding torques, and high power consumption. Lightweight robots and rovers have difficulties accommodating these requirements. To address these key challenges to the NASA objective of planetary in-situ ro...

Rayleigh-Taylor instability of an ablation front is one of the main issues that determine the performance of an inertial fusion target. In the last few years we have improved our understanding of this instability thanks to several analytical and semianalytical models developed mainly for the regime of relatively short perturbation wavelength λ (kL0 << 1 and k=2π/λ is the perturbation wave numbe...

The aim of this paper is to construct semi-implicit numerical schemes for a two-phase (two-fluid) flow model, allowing for violation of the CFL criterion for sonic waves while maintaining a high level of accuracy and stability on volume fraction waves. By using an appropriate hybridization of a robust implicit flux and an upwind explicit flux, we obtain a class of first-order schemes, which we ...

Astrophysical multi-phase media display rich spatial structures, as for example the cold cirrus clouds found in the neutral atomic interstellar medium. Condensation of cold structures in locally compressed regions of turbulent thermally bistable flows is a plausible, not exclusive, origin for the structuration of the medium. Simulations in plane-parallel geometry show that trans-sonic convergen...

Environmental data collected along 92.5 o E between 2.7 o N and 12.77 o N during late winter show a permanent sound velocity maximum around 75 m and an intermediate minimum between 1350 m and 1750 m. The axis of the deep sound channel is noticed around 1700 m. The shallower axial depth (~1350 m) between 7.5 o N and 10.5 o N coincides with the cyclonic eddy. Within the sonic layer (SLD), Eastern...

The purpose of this study was to monitor the setting behaviour and elastic modulus of luting cements using an ultrasonic device. The ultrasonic equipment comprised a pulser-receiver, transducers and an oscilloscope. The transit time through the cement disk was multiplied by the thickness of the specimen, and the sonic velocity within the material was then calculated. The sonic velocities of the...