Microfriction studies of model self-lubricating surfaces (open access)

Microfriction studies of model self-lubricating surfaces

Self-lubricating composites consist of at least one structural (matrix) phase and at least one phase to provide lubrication. Modeling the behavior of such composites involves ascertaining the frictional contributions of each constituent phase under varying conditions of lubricating films coverage. The ORNL friction microprobe (FMP), a specialized microcontact tribometer, was used to investigate the frictional behavior of both matrix and lubricant phases to support the development of self-lubricating, surfaces. Polished CVD-silicon carbide deposits and silicon wafers were used as substrates. The wafers were intended to simulate the thin silica films present on SiC surfaces at elevated temperature. Molybdenum disulfide, in both sputtered and burnished forms, was used as the model lubricant. The effects of CVD-SiC substrate surface roughness and method of lubricant film deposition on the substrate were studied for single passes of a spherical silicon nitride slider (NBD 200 material). In contrast to the smooth sliding exhibit by burnished, films, sputtered MoS{sub 2} surfaces exhibited marked stick-slip behavior, indicating that the frictional behavior of solid lubricating coatings can be quite erratic on a microscale, especially when asperity contacts are elastically compliant.
Date: May 6, 1993
Creator: Blau, P. J. & Yust, C. S.
System: The UNT Digital Library
User`s manual for elegant Program Version 12.4, Manual Version 1 (open access)

User`s manual for elegant Program Version 12.4, Manual Version 1

Elegant stands for ``Electron Generation and Tracking,`` a somewhat out-of-date description of a fully 6D accelerator program that now does much more than generate particle distributions and track them elegant, written entirely in the C programming language, uses a variant of the MAD input format to describe accelerators, which may be either transport lines, circular machines, or a combination thereof. Program execution is driven by commands in a namelist format. This document describes the features available in elegant, listing the commands and their arguments. The differences between elegant and MAD formats for describing accelerators are listed. A series of examples of elegant input and output are given. Finally, appendices are included describing the post-processing programs.
Date: May 6, 1993
Creator: Borland, M.
System: The UNT Digital Library
Procedure for the permeabilization and cryobiological preservation of Drosophila embryos (open access)

Procedure for the permeabilization and cryobiological preservation of Drosophila embryos

The authors describe the detailed protocol developed in their laboratory at Oak Ridge for the permeabilization and cryobiological preservation of embryos of Drosophila melanogaster, Oregon R strain. The protocol is supplemented by notes containing two sorts of information. One category includes references to the appropriate portions of their published papers giving the scientific rationale and experimental basis for important steps. The other category is concerned with the criticality of certain steps and the precision with which they need to be performed. As an aid to investigators, the authors list even ordinary pieces of equipment. Brand names and model numbers are given where it is either important or convenient for readers to know precisely what is used.
Date: May 6, 1993
Creator: Cole, K. W.; Schreuders, P. D.; Mahowald, A. P. & Mazur, Peter
System: The UNT Digital Library
Evaluating airborne radionuclide concentrations in the tank farms (open access)

Evaluating airborne radionuclide concentrations in the tank farms

The objective of this study is to determine, through the collection of grab sampling data, that an in-depth resuspension study should or should not be performed. Currently there is not enough data available to determine if a potential health hazard exists due to resuspended contamination in the tank farms. A detailed resuspension study is currently not justified, because the limited quantity of air sample data collected does not indicate the existence of a potential health hazard.
Date: May 6, 1993
Creator: Gleckler, B. P.
System: The UNT Digital Library