OBJECTIVES To evaluate in vitro the effect of cavity preparation with microburs and diamond-coated ultrasonic tips on the microleakage and marginal fit of six end-root filling materials. STUDY DESIGN. The following materials were assessed: amalgam (Amalcap), zinc oxide eugenol (IRM), glass ionomer (Vitrebond), compomer (Cavalite), mineral particle aggregate (MTA) and composite (Clearfil). Cavit...

introduction: root canal obturation seals the root canal system to prevent re-entry and/or growth of microorganisms. the provision of an appropriate restoration to coronally seal the access cavity affects the success of endodontic treatment. the purpose of this study was to evaluate the coronal microbial leakage in root canals that were either filled by lateral compaction, guttaflow or warm ver...

An ultrasonic testing method employing the pulse-echo inspection technique was developed to assess the integrity of annular seals surrounding casings (i.e.. instrument tubes or well casings). This nondestructive testing method permits testing aseal from inside acasing without disturbing the casing, seal. or formation. Seals constructed with cement-based and bentonite-based sealants surrounding ...

The carrying capacity of the French Frigate Shoals (FFS) region for the endangered Hawaiian monk seal was appraised using an updated version of the original FFS Ecopath model (Polovina 1984). Model parameters were updated using recent literature, and data from surveys of the seal population and its bottom-associated prey. Together they produced a static mass balance model for 1998 when the prey...

Security and reliability are the main focus of annular metal seal assembly. It is concluded that the factors influence sealing performance of annular metal seal assembly most in view of working conditions of annular metal seal assembly. Taking major influencing factors with response surface method (RSM) analysis, and determining coefficient of regression analysis with finite element method (ANS...

The use of CO2 for Enhanced Oil Recovery (EOR) has been around since the early 70’s and was developed to enable oil extraction from declining fields. The process involves injecting CO2 from either natural or man-made sources into the ground to free up trapped crude oil that would otherwise not be possible to obtain. This process significantly improves the lifetime production of oil from mature ...

Thermally induced failures have long since plagued mechanical seal users. Over the years these failures have led to the development of different flush plan and seal design features that are used to increase heat transfer from the seal interface. In this paper the first experimental results for a new mechanical seal design operating in a pump are presented. In this design a heat sink, consisting...