Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Boundary Conditions in Diffusional Growth and Sedimentation   In many applications, transport of particles can be described by the
diffusion equation, or its convective-diffusion generalizations, in part of
three-dimensional space. In particular, in surface deposition or in growth of
aggregates or sediments, particles in the suspension outside the surface or
aggregate boundary can be considered as diffusing under the influence of
applied forces, such as the double-layer interactions or gravity. However, the
diffusion equation cannot be used at the substrate or inside the aggregate. One
convenient and widely used approach has been to impose boundary conditions at
the surface, to supplement and completely define the diffusion problem outside
it. This short survey describes some theoretical results on the use of such
boundary conditions and their physical interpretation.

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The categories of this paper are: alg-geom
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The categories of this paper are: astro-ph
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The categories of this paper are: plasm-ph
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The categories of this paper are: nucl-th
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The categories of this paper are: supr-con
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The categories of this paper are: bayes-an
3
The categories of this paper are: physics
5
The categories of this paper are: gr-qc
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The categories of this paper are: q-alg
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The categories of this paper are: mtrl-th
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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: atom-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: adap-org
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The categories of this paper are: patt-sol