Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Micron-scale droplet deposition on a hydrophobic surface using a
  retreating syringe   Droplet deposition onto a hydrophobic surface is studied experimentally and
numerically. A wide range of droplet sizes can result from the same syringe,
depending strongly on the needle retraction speed. Three regimes are identified
according to the motion of the contact line. In Region I, at slow retraction
speeds, the contact line expands and large droplets can be achieved. In Region
II, at moderate needle speeds, a quasi-cylindrical liquid bridge forms
resulting in drops approximately the size of the needle. Finally, at high
speeds (Region III), the contact line retracts and droplets much smaller than
the syringe diameter are observed. Scaling arguments are presented identifying
the dominant mechanisms in each regime. Results from nonlinear numerical
simulations agree well with the experiments, although the accuracy of the
predictions is limited by inadequate models for the behavior of the dynamic
contact angle.

4
The categories of this paper are: cond-mat
16
The categories of this paper are: stat
26
The categories of this paper are: bayes-an
27
The categories of this paper are: comp-gas
29
The categories of this paper are: funct-an
9
The categories of this paper are: nlin
13
The categories of this paper are: quant-ph
12
The categories of this paper are: nucl-th
20
The categories of this paper are: acc-phys
19
The categories of this paper are: eess
28
The categories of this paper are: alg-geom
30
The categories of this paper are: q-alg
33
The categories of this paper are: plasm-ph
7
The categories of this paper are: hep-th
32
The categories of this paper are: atom-ph
37
The categories of this paper are: supr-con