Different desorption rates prompting an indirect isotopic effect on nanoscale friction

The paper introduces an alternative approach to predict boundary friction for rough surfaces at micros-scale through the empirical integration of asperity-like nanoscale friction measurements. The nanoscale friction is measured using an atomic force microscope (AFM) tip sliding on a steel plate, confining the test lubricant, i.e. base oil for the fully formulated SAE grade 10w40. The approach, based on the Greenwood and Tripp’s friction model, is combined with the modified Elrod’s cavitation algorithm in order to predict the friction generated by a slider-bearing test rig. The numerical simulation results, using an improved boundary friction model, showed good agreement with the measured friction data.

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Vibrations reduce nanoscale friction

Materials Today ◽

10.1016/s1369-7021(06)71615-7 ◽

2006 ◽

Vol 9 (9) ◽

pp. 15

Author(s):

Paula Gould

Keyword(s):

Nanoscale Friction

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Interface-dependent nanoscale friction of copper bicrystals: tilt versus twist

RSC Advances ◽

10.1039/c6ra10879b ◽

2016 ◽

Vol 6 (64) ◽

pp. 59206-59217 ◽

Cited By ~ 7

Author(s):

J. J. Zhang ◽

Z. F. Wang ◽

Y. D. Yan ◽

T. Sun

Keyword(s):

Structure Dependence ◽

Nanoscale Friction

Dislocation–GB interactions and GB evolution significantly vary with GB type, yielding a strong GB structure dependence of the frictional response.

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Untersuchung von Calciumisotopieeffekten bei heterogenen Austauschgleichgewichten / Investigation of Isotopic Effects of Calcium in Heterogeneous Exchange Equilibria

Zeitschrift für Naturforschung B ◽

10.1515/znb-1972-0204 ◽

1972 ◽

Vol 27 (2) ◽

pp. 126-133 ◽

Cited By ~ 33

Author(s):

Klaus Gustav Heumann ◽

Karl Heinrich Lieser

Keyword(s):

Separation Factor ◽

Calcium Concentration ◽

Isotopic Fractionation ◽

Ion Source ◽

Isotopic Effect ◽

Mass Unit ◽

Calcium Isotopes ◽

Heterogeneous Exchange ◽

Loaded Column ◽

Isotopic Effects

The following heterogeneous exchange equilibria have been examined for isotopic effects: CaCO3/Ca(aq.)2⊕. Ca-GBHA/Ca(aq.)2⊕ and Ca(Dowex 50)2⊕/Ca(aq.)2⊕ (GBHA = glyoxal-bis (2-hydroxyanil)). The isotopic ratios 44Ca/40Ca and 48Ca/40Ca were determined by means of a mass spectrometer with a thermal ion source. In the system CaCO3/Ca(aq.)2⊕, the elementary separation factor was found to be less than 1‰ or 0,5‰ per mass unit, respectively.For the exchange in the system Ca-GBHA/Ca(aq.)2⊕ in the concentration range from 0.011 to 0.84 M an elementary separation factor less than 1‰ per mass unit was found; from a three-stage experiment at a calcium concentration of 1.23 M it was concluded that the elementary isotopic effect is less than 0.4‰ per mass unit. Therefore no isotopic fractionation is to be expected for precipitation of inorganic or organic calcium salts.An enrichment of the heavier calcium isotopes in the solution was found in the case of the exchange in a Dowex 50-X12 loaded column. The isotopic effect depends on the concentration of the hydrochloric acid used as the eluent.

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