Suppression of coffee ring: (Particle) size matters

2018 ◽  
Vol 112 (21) ◽  
pp. 211605 ◽  
Author(s):  
Lalit Bansal ◽  
Pranjal Seth ◽  
Bhubesh Murugappan ◽  
Saptarshi Basu
Keyword(s):  
Particle Size ◽  
Coffee Ring ◽  
Ring Particle

The E-ring: interactions with plasma and implications for its evolution

1984 ◽  
Vol 75 ◽  
pp. 599-602
Author(s):  
T.V. Johnson ◽  
G.E. Morfill ◽  
E. Grun
Keyword(s):  
Time Scale ◽  
Particle Density ◽  
High Energy ◽  
Particle Removal ◽  
Density Region ◽  
Drag Forces ◽  
Orbit Evolution ◽  
History Of ◽  
Ring Particle ◽  
Ring Material

A number of lines of evidence suggest that the particles making up the E-ring are small, on the order of a few microns or less in size (Terrile and Tokunaga, 1980, BAAS; Pang et al., 1982 Saturn meeting; Tucson, AZ). This suggests that a variety of electromagnetic and plasma affects may be important in considering the history of such particles. We have shown (Morfill et al., 1982, J. Geophys. Res., in press) that plasma drags forces from the corotating plasma will rapidly evolve E-ring particle orbits to increasing distance from Saturn until a point is reached where radiation drag forces acting to decrease orbital radius balance this outward acceleration. This occurs at approximately Rhea's orbit, although the exact value is subject to many uncertainties. The time scale for plasma drag to move particles from Enceladus' orbit to the outer E-ring is ~104yr. A variety of effects also act to remove particles, primarily sputtering by both high energy charged particles (Cheng et al., 1982, J. Geophys. Res., in press) and corotating plasma (Morfill et al., 1982). The time scale for sputtering away one micron particles is also short, 102 - 10 yrs. Thus the detailed particle density profile in the E-ring is set by a competition between orbit evolution and particle removal. The high density region near Enceladus' orbit may result from the sputtering yeild of corotating ions being less than unity at this radius (e.g. Eviatar et al., 1982, Saturn meeting). In any case, an active source of E-ring material is required if the feature is not very ephemeral - Enceladus itself, with its geologically recent surface, appears still to be the best candidate for the ultimate source of E-ring material.

How a sheperd guides a sheep herd?

1984 ◽  
Vol 75 ◽  
pp. 331-337
Author(s):  
Richard Greenberg
Keyword(s):  
Point Of View ◽  
Single Ring ◽  
Damping Effects ◽  
Ring Particle

ABSTRACTThe mechanism by which a shepherd satellite exerts a confining torque on a ring is considered from the point of view of a single ring particle. It is still not clear how one might most meaningfully include damping effects and other collisional processes into this type of approach to the problem.

Microstructural characterization of laser-melted/roller-quenched dicalcium silicate

1988 ◽  
Vol 46 ◽  
pp. 582-583
Author(s):  
C. J. Chan ◽  
K. R. Venkatachari ◽  
W. M. Kriven ◽  
J. F. Young
Keyword(s):  
Particle Size ◽  
Raw Materials ◽  
Shape Change ◽  
Microstructural Characterization ◽  
Particle Size Effect ◽  
Dicalcium Silicate ◽  
Laser Melting ◽  
Uniform Size ◽  
Cell Shape Change ◽  
Wide Range

Dicalcium silicate (Ca2SiO4) is a major component of Portland cement. It has also been investigated as a potential transformation toughener alternative to zirconia. It has five polymorphs: α, α'H, α'L, β and γ. Of interest is the β-to-γ transformation on cooling at about 490°C. This transformation, accompanied by a 12% volume increase and a 4.6° unit cell shape change, is analogous to the tetragonal-to-monoclinic transformation in zirconia. Due to the processing methods used, previous studies into the particle size effect were limited by a wide range of particle size distribution. In an attempt to obtain a more uniform size, a fast quench rate involving a laser-melting/roller-quenching technique was investigated.The laser-melting/roller-quenching experiment used precompacted bars of stoichiometric γ-Ca2SiO4 powder, which were synthesized from AR grade CaCO3 and SiO2xH2O. The raw materials were mixed by conventional ceramic processing techniques, and sintered at 1450°C. The dusted γ-Ca2SiO4 powder was uniaxially pressed into 0.4 cm x 0.4 cm x 4 cm bars under 34 MPa and cold isostatically pressed under 172 MPa. The γ-Ca2SiO4 bars were melted by a 10 KW-CO2 laser.

Analytical Electron Microscopy study of two vehicle-aged automotive exhaust catalysts having dissimilar activities

1989 ◽  
Vol 47 ◽  
pp. 272-273
Author(s):  
Sooho Kim ◽  
M. J. D’Aniello
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Noble Metal ◽  
Catalyst Deactivation ◽  
Analytical Electron Microscopy ◽  
Microscopy Study ◽  
Metal Particles ◽  
Automotive Exhaust ◽  
Exhaust Catalysts ◽  
Analytical Electron

Automotive catalysts generally lose-agtivity during vehicle operation due to several well-known deactivation mechanisms. To gain a more fundamental understanding of catalyst deactivation, the microscopic details of fresh and vehicle-aged commercial pelleted automotive exhaust catalysts containing Pt, Pd and Rh were studied by employing Analytical Electron Microscopy (AEM). Two different vehicle-aged samples containing similar poison levels but having different catalytic activities (denoted better and poorer) were selected for this study.The general microstructure of the supports and the noble metal particles of the two catalysts looks similar; the noble metal particles were generally found to be spherical and often faceted. However, the average noble metal particle size on the poorer catalyst (21 nm) was larger than that on the better catalyst (16 nm). These sizes represent a significant increase over that found on the fresh catalyst (8 nm). The activity of these catalysts decreases as the observed particle size increases.

Effect of particle size on erosion measurements and predictions in annular flow for an elbow

Wear ◽  
2020 ◽  
pp. 203579
Author(s):  
G. Haider ◽  
M. Othayq ◽  
J. Zhang ◽  
R.E. Vieira ◽  
S.A. Shirazi
Keyword(s):  
Particle Size ◽  
Annular Flow ◽  
Effect Of Particle Size
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