Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Capacitive Deionization -- defining a class of desalination technologies   Over the past decade, capacitive deionization (CDI) has realized a surge in
attention in the field of water desalination and can now be considered as an
important technology class, along with reverse osmosis and electrodialysis.
While many of the recently developed technologies no longer use a mechanism
that follows the strict definition of the term "capacitive", these methods
nevertheless share many common elements that encourage treating them with
similar metrics and analyses. Specifically, they all involve electrically
driven removal of ions from a feed stream, storage in an electrode (i.e., ion
electrosorption) and release, in charge/discharge cycles. Grouping all these
methods in the technology class of CDI makes it possible to treat evolving new
technologies in standardized terms and compare them to other technologies in
the same class.

35
The categories of this paper are: mtrl-th
5
The categories of this paper are: gr-qc
26
The categories of this paper are: bayes-an
24
The categories of this paper are: dg-ga
20
The categories of this paper are: acc-phys
16
The categories of this paper are: stat
11
The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph
15
The categories of this paper are: nucl-ex
28
The categories of this paper are: alg-geom
1
The categories of this paper are: cs
2
The categories of this paper are: math
10
The categories of this paper are: q-bio
18
The categories of this paper are: econ
36
The categories of this paper are: cmp-lg
7
The categories of this paper are: hep-th