Publications

Results 80451–80475 of 96,771

Search results

Jump to search filters

Macro- to nanoscale wear prevention via molecular adsorption

Proposed for publication in Science.

Dugger, Michael T.; Ohlhausen, J.A.

As the size of mechanical systems shrinks from macro- to nanoscales, surface phenomena such as adhesion, friction, and wear become increasingly significant. This paper demonstrates the use of alcohol adsorption as a means of continuously replenishing the lubricating layer on the working device surfaces and elucidates the tribochemical reaction products formed in the sliding contact region. Friction and wear of native silicon oxide were studied over a wide range of length scales from macro- to nanoscales using a ball-on-flat tribometer (millimeter scale), sidewall microelectromechanical system (MEMS) tribometer (micrometer scale), and atomic force microscopy (nanometer scale). In all cases, the alcohol vapor adsorption successfully lubricated and prevented wear. Imaging time-of-flight secondary ion mass spectrometry analysis of the sliding contact region revealed that high molecular weight oligomeric species were formed via tribochemical reactions of the adsorbed linear alcohol molecules. These tribochemical products seemed to enhance the lubrication and wear prevention. In the case of sidewall MEMS tests, the lifetime of the MEMS device was radically increased via vapor-phase lubrication with alcohol.

More Details
TYPE Journal Article YEAR 2007
OSTI

Estimating Z-Pinch computing resources

Brunner, Thomas A.

The Z facility at Sandia National Laboratories produces high energy density environments. Computer simulations of the experiments provide key insights and help make the most efficient use of the facility. This document estimates the computer resources needed in order to support the experimental program. The resource estimate is what we would like to have in about five years and assumes that we will have a robust, scalable simulation capability as well as enough physicists to run the simulations.

More Details
TYPE SAND Report YEAR 2007
DOIOSTI

Model for resonant plasma probe

Johnson, William Arthur.; Coats, Rebecca S.; Jorgenson, Roy E.; Hebner, Gregory A.

This report constructs simple circuit models for a hairpin shaped resonant plasma probe. Effects of the plasma sheath region surrounding the wires making up the probe are determined. Electromagnetic simulations of the probe are compared to the circuit model results. The perturbing effects of the disc cavity in which the probe operates are also found.

More Details
TYPE SAND Report YEAR 2007
DOIOSTI
Results 80451–80475 of 96,771
Results 80451–80475 of 96,771