Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spinning and tumbling of micron-sized triangles in a micro-channel shear
  flow   We report on measurements of the angular dynamics of micron-sized
equilaterally triangular platelets suspended in a micro-channel shear flow. Our
measurements confirm that such particles spin and tumble like a spheroid in a
simple shear. Since the triangle has corners we can observe the spinning
directly. In general the spinning frequency is different from the tumbling
frequency, and the spinning is affected by tumbling. This gives rise to
doubly-periodic angular dynamics.

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The categories of this paper are: cond-mat
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The categories of this paper are: atom-ph
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The categories of this paper are: astro-ph
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The categories of this paper are: gr-qc
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The categories of this paper are: q-fin
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The categories of this paper are: nucl-ex
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The categories of this paper are: eess
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The categories of this paper are: plasm-ph
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The categories of this paper are: stat
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The categories of this paper are: chao-dyn
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The categories of this paper are: alg-geom
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The categories of this paper are: ao-sci
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The categories of this paper are: chem-ph
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The categories of this paper are: hep-lat
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The categories of this paper are: hep-ex
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The categories of this paper are: q-bio