Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Surface Alignment, Anchoring Transitions, Optical Properties, and
  Topological Defects in the Thermotropic Nematic Phase of an Organo-Siloxane
  Tetrapodes   We perform optical, surface anchoring, and textural studies of an
organo-siloxane tetrapode material in the broad temperature range of the
nematic phase. The optical, structural, and topological features are compatible
with the uniaxial nematic order rather than with the biaxial nematic order, in
the entire nematic temperature range -25C < T < 46C studied. For homeotropic
alignment, the material experiences surface anchoring transition, but the
director can be realigned into an optically uniaxial texture by applying a
sufficiently strong electric field. The topological features of textures in
cylindrical capillaries, in spherical droplets and around colloidal inclusions
are consistent with the uniaxial character of the long-range nematic order. In
particular, we observe isolated surface point defect-boojums and bulk point
defects-hedgehog that can exist only in the uniaxial nematic.

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The categories of this paper are: nucl-th
35
The categories of this paper are: mtrl-th
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The categories of this paper are: q-bio
8
The categories of this paper are: hep-ex
0
The categories of this paper are: hep-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: bayes-an
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The categories of this paper are: adap-org
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The categories of this paper are: econ
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The categories of this paper are: hep-lat
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The categories of this paper are: eess
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The categories of this paper are: nlin
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The categories of this paper are: q-alg
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The categories of this paper are: q-fin
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The categories of this paper are: cs
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The categories of this paper are: atom-ph