For the test fluids of this article, the particles and up to 1% sodium dodecyl sulfate (a surfactant) were dispersed into the base fluid using a sonicator (a UP200 from Hielscher Ultrasonics GmbH, Teltow, Germany) for 15 to 30 min. From our experience, probe-type sonicators break particle agglomerates faster and much more thoroughly than bath-type sonicators.
At the highest stress in the Berea system (20 kpsi or 138 MPa), individual proppant particles failed and the broken particles caused significant loss of permeability.
In addition to beads or broken particles, MICs can also be prepared in other very different forms, such as monoliths, microcapsules, membranes or surfaces [10].
These results suggested that some particle disruption was generated by the higher-dose UV exposure and that these broken particles then could aggregate.
Lower doses of UV previously reported to inactivate CPMV infectivity inhibited symptoms on inoculated leaves but did not prohibit systemic virus spread in plants, whereas higher doses caused aggregation of the particles and an increase in chemical reactivity further indicating broken particles.
Dareta and Yargalma sweep and soil samples contained broken particles of the same complex suite of primary and secondary lead minerals as unprocessed and ground vein ores [see Supplemental Material, Table S2 (http://dx.doi.org/10.1289/ehp.1206051)].
Sepabeads EC-EP were fully stable with all particles present in perfect spherical shape; also the Strep-Tactin MacroPrep material, which is not originally designed for use in a reactor, exhibited good mechanical stability with only a minor fraction of broken particles.
This symmetry-breaking particle will be avidly sought when a powerful new particle accelerator, the Large Hadron Collider, comes on line several years from now in Geneva.
The third dispersion method is tantamount to breaking particle agglomerations by physical means, for instance mechanical agitation, ultrasonic waves, and stirred bead milling.
The objective of the comminution process is to break complex particles consisting of numerous minerals into smaller simpler particles where individual particles consist primarily of only one mineral.
Landslides will break up particles, as will chemical alteration of rocks exposed at the surface.
