Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Fluorescent contacts measure the coordination number and entropy of a 3D
  jammed emulsion packing   Jammed matter is by definition impenetrable to light, rendering the
characterization of the 3D geometry difficult. Confocal microscopy of a dyed,
refractive index matched emulsion nevertheless allows one to image the jammed
system. Here we explain the origin of the mechanism of enhanced fluorescence at
the contacts of jammed emulsion droplets in terms of a blue-shifted
fluorescence emission band due to the change in the polarity of the interfacial
environment. We then use this information to determine the contact network in
the emulsion, which models a frictionless jammed system. This enables the
experimental determination of the average coordination number, $<Z >$ giving
the theoretically predicted value of $<Z > \approx 6$. Furthermore, the method
enables the experimental measurement of the entropy of the packing from the
network of contacts.

33
The categories of this paper are: plasm-ph
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The categories of this paper are: mtrl-th
20
The categories of this paper are: acc-phys
16
The categories of this paper are: stat
6
The categories of this paper are: astro-ph
12
The categories of this paper are: nucl-th
22
The categories of this paper are: chao-dyn
21
The categories of this paper are: adap-org
1
The categories of this paper are: cs
2
The categories of this paper are: math
34
The categories of this paper are: chem-ph
8
The categories of this paper are: hep-ex
11
The categories of this paper are: hep-lat
31
The categories of this paper are: ao-sci
30
The categories of this paper are: q-alg
32
The categories of this paper are: atom-ph