Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Multi-walled carbon nanotube films for the measurement of the alcoholic
  concentration   We show that a multi-walled carbon nanotube film can be used as the sensing
element of a low-cost sensor for the alcoholic concentration in liquid
solutions. To this purpose, we investigate the electrical resistance of the
film as a function of the isopropanol concentration in a water solution. The
analysis reveals a growing resistance with increasing isopropanol concentration
and a fast response. The sensing element is re-usable as the initial resistance
value is restored once the solution has evaporated. The electrical resistance
increases linearly when the multi-walled carbon nanotube film is exposed to
common beverages with increasing alcoholic content. This work paves the way for
the development of low-cost, miniaturized MWCNT-based sensors for quality
monitoring and control of alcoholic beverages and general liquid solutions.

29
The categories of this paper are: funct-an
16
The categories of this paper are: stat
6
The categories of this paper are: astro-ph
36
The categories of this paper are: cmp-lg
25
The categories of this paper are: patt-sol
28
The categories of this paper are: alg-geom
1
The categories of this paper are: cs
11
The categories of this paper are: hep-lat
27
The categories of this paper are: comp-gas
33
The categories of this paper are: plasm-ph
31
The categories of this paper are: ao-sci
30
The categories of this paper are: q-alg
14
The categories of this paper are: math-ph
15
The categories of this paper are: nucl-ex
3
The categories of this paper are: physics
13
The categories of this paper are: quant-ph