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Why nature thinks bigger is better

IOWA STATE (US) — In a new paper, a team of scientists sheds light on coarsening, the natural process during which “the big get bigger.”

Coarsening happens when a group of objects of different sizes transforms into fewer objects with larger average size. Examples include the geologic formation of gemstones, the degradation of pharmaceutical suspensions, and the manufacture of structural steels.

To illustrate the concept, Patricia Thiel of Iowa State University and the U.S. Department of Energy’s Ames Laboratory puts a box of tissues to the right, a stack of coasters in the middle, and a trinket box to the left.

“Nature,” she says, “doesn’t want lots of little things.” So Thiel grabs the smaller things and slides them into a single pile next to the bigger tissue box. “Nature wants one big thing all together, like this.”

Thiel and colleagues have been using scanning tunneling microscope technology—an instrument that allows them to see individual atoms—to study how coarsening happens on the surface of objects. Their work is reported in the Oct. 29 issue of the journal Science.

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They’ve studied nanoscale particles grown on the surface of silver and how adding sulfur can increase coarsening. They’re trying to learn the mechanism of that increase and understand the nature of the messengers that move atoms during the coarsening process.

What the researchers are looking for is a general principle that explains what they call additive-enhanced coarsening. To do that, Thiel says, they still need to collect and analyze data from more coarsening systems.

James Evans, an Iowa State professor of physics and astronomy and a faculty scientist for the Ames Laboratory, says a better understanding of the coarsening process can help researchers develop small structures—including nanoscale technologies, catalysts, or drug suspensions—that resist coarsening and are therefore more durable.

A better understanding could also help researchers manipulate coarsening to develop structures with a very narrow distribution of particle sizes, something important to some nanotechnologies.

“When we’re building something on a small scale, for it to be useful, it has to be robust, it has to survive,” Evans says. “And one thing we’re looking at is the stability of the very tiny structures that are crucial to nanoscale technologies.”

The work was supported by the National Science Foundation.

More news from Iowa State: www.news.iastate.edu/

chat3 Comments

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3 Comments

  1. Alfred Cassis

    Hello, nicely put, it fascinates a lot, but I’d like to add something I observed
    A- Everything combined &/or created or reached (at), resulting from an otherwise combination of elements, will take the size it needs to manifest itself in the surrounding it finds itself in, although it will do so to the extent that it does not meet an opposite resistance, or a resistance it can not overcome…
    B- When meeting resistance, automatically a counter-measure is created -in everything- a struggle takes place with the results we can observe; this result is always temporary as all components adjust & constantly re-claim their position, & that is the true constant.
    Regards.

  2. Alfred Cassis

    The resulting size will always be governed by the existent surrounding resistance as well as the reaction provoked by the intrusion – never limited in time, to wit: the earth-quakes & aftershocks – .
    An important point not to be forgotten (overlooked) dismissed or mis-understood.

  3. Alfred Cassis

    Consider the difference in sizes from the Dinosaurs to the humble mice & smaller; viruses etc.
    Extinction, Survival & Existence are also ruled by necessity availability & opportunity.
    That & all of the above must first come in the influences on the possibilities of size.

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