Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Macroscopic Dust in Protoplanetary Disks - From Growth to Destruction   The collision dynamics of dusty bodies are crucial for planetesimal
formation. Especially decimeter agglomerates are important in the different
formation models. Therefore, in continuation of our experiments on mutual
decimeter collisions, we investigate collisions of centimeter onto decimeter
dust agglomerates in a small drop tower under vacuum conditions (p<5*$10^{-1}$
mbar) at a mean collision velocity of 6.68 +- 0.67m/s. We use quartz dust with
irregularly shaped micrometer grains. Centimeter projectiles with different
diameters, masses and heights are used, their typical volume filling factor is
$\Phi_{p,m}$=0.466+-0.02. The decimeter agglomerates have a mass of about
1.5kg, a diameter and height of 12cm and a mean filling factor of
$\Phi_{t,m}$=0.44+-0.004. At lower collision energies only the projectile gets
destroyed and mass is transferred to the target. The accretion efficiency
decreases with increasing obliquity and increasing difference in filling
factor, if the projectile is more compact than the target. The accretion
efficiency increases with increasing collision energy for collision energies
under a certain threshold. Beyond this threshold at 298+-25 mJ catastrophic
disruption of the target can be observed. This corresponds to a critical
fragmentation strength Q*=190+-16 mJ/kg, which is a factor of four larger than
expected. Analyses of the projectile fragments show a power law size
distribution with average exponent of -3.8+-0.3. The mass distributions suggest
that the fraction of smallest fragments increases for higher collision
energies. This is interesting for impacts of small particle on large target
bodies within protoplanetary disks, as smaller fragments couple better to the
surrounding gas and re-accretion by gas drag is more likely.

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The categories of this paper are: nlin
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The categories of this paper are: q-bio
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The categories of this paper are: cond-mat
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The categories of this paper are: plasm-ph
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The categories of this paper are: math-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: q-fin
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The categories of this paper are: math
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The categories of this paper are: hep-ex
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The categories of this paper are: chao-dyn
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The categories of this paper are: adap-org
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The categories of this paper are: acc-phys
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The categories of this paper are: chem-ph
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The categories of this paper are: supr-con
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The categories of this paper are: bayes-an
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The categories of this paper are: cmp-lg