This study investigated the influence of implant abutment and screw access channel modification on the retention of copings. Titanium abutment access openings were either left open or modified by placing two vent holes 3 mm from the occlusal edge and 180 degrees apart. Access openings sealed with a resin material were used as controls. Metal copings were cemented and subjected to tensile testin...

We present a brief historical overview of the classical theory of a radiating point charge, described by the Lorentz-Dirac equation. A recent development is the discovery of tunnelling of a charge through a potential barrier, in a completely classical context. Also, a concrete example is discussed of the existence of several physically acceptable solutions for a range of initial data. We end by...

A theory of field induced electron emission from electrolytic conductors is proposed in which an electron associated with an immobile anion at the surface is destabilised as a cation moves into the bulk. This electron may be thermally emitted over a field-lowered barrier. Equations are developed for the potential barrier that must be surmounted by the electron and the form of the current versus...

We show that the sphaleron energy which identifies with the (instanton) potential barrier for B-violation is reduced in the presence (background) of an electroweak Z-string. We also show that for large enough Higgs coupling, λ, the sphaleron energy can go negative. For such λ, electroweak Z-strings can reduce their energy by accumulating sphaleron bound states. This further endows them with bar...

What infants decide to do does not necessarily reflect the extent of what they know. In the current study, 17-month-olds were encouraged to walk through openings of varying width under risk of entrapment. Infants erred by squeezing into openings that were too small and became stuck, suggesting that they did not accurately perceive whether they could fit. However, a second penalty condition reve...

In this paper, we use vertically invariant morphological filters for time-varying or adaptive signal processing. The morphological filters adopted in this paper are vertically invariant openings and closings. Vertically invariant openings and closings have intuitive geometric interpretations and can provide different filtering scales with respect to different spacial positions. Hence, they are ...

The Bureau of Labor Statistics (BLS) has begun a new survey to collect and publish job openings and labor turnover data. This new survey, the Job Openings and Labor Turnover Survey, or JOLTS, began collecting data in March 2000 and will soon publish estimates for the first time. Published estimates will include rates and levels for job openings, hires, and separations. These data will add to th...