Zobrazeno 1 - 10
of 52
pro vyhledávání: '"Stephen V. Pepper"'
Autor:
Jonathan I. Brauer, Phillip B. Abel, Stephen V. Pepper, Christopher Dellacorte, Glenn Glennon, Eric J. Bylaska, David A. Dixon, Ronald D. Noebe, Amanda C. Stott, Anita Garg
Publikováno v:
The Journal of Physical Chemistry C. 114:19704-19713
Spiral orbit tribometry friction tests performed on Ni-rich Ni55Ti45 titanium ball bearings indicate that this alloy is a promising candidate for future aerospace bearing applications. Microstructural characterization of the bearing specimens was per
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::7cc2ea072cd493683843f3cd56b59a2c
https://doi.org/10.1021/jp103552s
https://doi.org/10.1021/jp103552s
Autor:
Stephen V. Pepper
Publikováno v:
Tribology Transactions. 51:723-729
Spiral orbit tribometry has been used to study the coefficient of friction and electrical contact resistance of two vacuum lubricants in both the flooded system and the regime in which only a few nanoliters (μ g) of the lubricant are present, and th
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::cd74b24e022b136825f4e154e69e4502
https://doi.org/10.1080/10402000801888929
https://doi.org/10.1080/10402000801888929
Publikováno v:
Tribology Letters. 14:61-67
Many moving mechanical assemblies (MMAs) for space applications rely on a small, initial charge of lubricant for the entire mission lifetime, often in excess of five years. In many cases, the premature failure of a lubricated component can result in
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::7a7c497cfb9b7d720fa3cecd8b3ebf11
https://doi.org/10.1023/a:1021791817718
https://doi.org/10.1023/a:1021791817718
Autor:
Edward P. Kingsbury, Stephen V. Pepper
Publikováno v:
Tribology Transactions. 46:65-69
The coefficients of friction and relative degradation rates of three lubricants run in the boundary regime in vacuum are evaluated in a Spiral Orbit Tribometer. This tribometer subjected the lubricants to rolling contact conditions similar to those f
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::cd9ccebfe1025c60692f61b80f590bf1
https://doi.org/10.1080/10402000308982601
https://doi.org/10.1080/10402000308982601
Autor:
Edward P. Kingsbury, Stephen V. Pepper
Publikováno v:
Tribology Transactions. 46:57-64
A new rolling contact tribometer based on a planar thrust bearing geometry is described. The bearing 'races' are flat plates that drive a ball into a near-circular, spiral path. The spiraling ball is returned to its initial radius each revolution aro
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::bae3822ddcac70262b98b08d8437416c
https://doi.org/10.1080/10402000308982600
https://doi.org/10.1080/10402000308982600
Publikováno v:
Tribology Transactions. 46:452-459
Many of today's spacecraft have long mission lifetimes. Whatever the lubrication method selected, the initial lubricant charge is required to last the entire mission. Fluid lubricant losses are mainly due to evaporation, tribo-degradation, and oil cr
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::6b7e88fbe68a91f3146c9da649ee2f87
https://doi.org/10.1080/10402000308982650
https://doi.org/10.1080/10402000308982650
Autor:
Stephen V. Pepper, Donald R. Wheeler
Publikováno v:
Review of Scientific Instruments. 71:1509-1515
The x-ray spectrum from a dual anode x-ray source in an x-ray photoelectron spectroscopy system was calculated by the NIST Desk Top Spectrum Analyzer used for synthesizing spectra in energy dispersive x-ray analyzers commonly found in scanning electr
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::dca3b9d7a2b60cc2e18005d772237ce4
https://doi.org/10.1063/1.1150498
https://doi.org/10.1063/1.1150498
Autor:
Mark J. Jansen, Achim Schröer, William R. Jones, QuynhGiao N. Nguyen, Donald R. Wheeler, Stephen V. Pepper
Publikováno v:
Tribology Transactions. 43:685-688
A vacuum spiral orbit tribometer (SOT) was used to determine the relative lifetimes of a branched perfluoropolyalkylether (PFPAE) on 440 C stainless steel. The effect of varying the mean Hertzian stress (0.75, 1.0, 1.5 and 2.0 GPa) and the use of TiC
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::1153a2d1c5bf709ec7a11d948f57623c
https://doi.org/10.1080/10402000008982397
https://doi.org/10.1080/10402000008982397
Publikováno v:
Thin Solid Films. :718-721
The mid-IR bulk optical constants for the lubricants Fomblin, Demnum S200, 2001A and Krytox 16256N, as well as water, are determined by infrared ellipsometric analysis using an Attenuated Total Reflection (ATR) cell. The water optical constants close
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::680ebf1687d8d5d5e6309c27177e213f
https://doi.org/10.1016/s0040-6090(97)00984-x
https://doi.org/10.1016/s0040-6090(97)00984-x
Publikováno v:
Journal of Tribology. 119:525-530
The NASA Ball on Plate Tribometer was built for the investigation of boundary lubricated rolling. Its contact conditions are easily calculated, and can be adjusted to match a range of real hearing applications for stress, surface velocity, pivot, and
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::7b1fbbc991f8f965befd977d50b64bd7
https://doi.org/10.1115/1.2833532
https://doi.org/10.1115/1.2833532