Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Slow dynamics in a single glass bead   Slow dynamic nonlinearity is ubiquitous amongst brittle materials, such as
rocks and concrete, with cracked microstructures. A defining feature of the
behavior is the logarithmic-in-time recovery of stiffness after a mechanical
conditioning. Materials observed to exhibit slow dynamics are sufficiently
different in microstructure, chemical composition, and scale (ranging from the
laboratory to the seismological) to suggest some kind of universality. There
lacks a consensus theoretical understanding of the universality in general and
the log(time) recovery in particular. Seminal studies were focused on
sandstones and other natural rocks, but in recent years other experimental
venues have been introduced with which to inform theory. One such system is
unconsolidated glass bead packs. However, bead packs still contain many contact
points. The force distribution amongst the contacts is unknown. Here, we
present slow dynamics measurements on a yet simpler system - a single glass
bead confined between two large glass plates. The system is designed with a
view towards rapid control of the contact zone environment. Ultrasonic waves
are used as a probe of the system, and changes are assessed with coda wave
interferometry. Three different methods of low-frequency conditioning are
applied; all lead to slow dynamic recoveries. Results imply that force chains
do not play an essential role in granular media slow dynamics, as they are
absent in our system.

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The categories of this paper are: math
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The categories of this paper are: hep-th
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The categories of this paper are: cs
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The categories of this paper are: hep-ph
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The categories of this paper are: gr-qc
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The categories of this paper are: plasm-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: hep-lat
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The categories of this paper are: quant-ph
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The categories of this paper are: ao-sci
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The categories of this paper are: eess
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The categories of this paper are: econ
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The categories of this paper are: chem-ph
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The categories of this paper are: funct-an
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The categories of this paper are: adap-org
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The categories of this paper are: alg-geom