Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Lifetime of respiratory saliva droplets   Respiratory transmission by airborne droplets is the leading mechanism by
which SARS-CoV-2 spreads. Motivated by the pressing need to understand this
spread, we formulate a model of the dynamics of respiratory saliva droplets,
quantifying the relative contribution of key factors to the airborne lifetime
of virus-carrying droplets. We consider a simple momentum balance to calculate
the spread of respiratory droplets, accounting for their size evolution as they
undergo vaporisation via mass and energy balances. The model shows how an
increase in relative humidity leads to larger descent rates, which shorten the
lifetime of droplets and therefore reduce the risk of transmission. Emulating
indoor air turbulence using a stochastic process, we numerically calculate
probability distributions for the lifetime of droplets, showing how an increase
in the air turbulent velocity significantly enhances the range of lifetimes.
The distributions reveal non-negligible probabilities for very long lifetimes,
which potentially escalate the risk of transmission. The droplet model may be
coupled with more detailed models for the air flow to study the lifetime and
spread of saliva droplets in specific spaces.

26
The categories of this paper are: bayes-an
5
The categories of this paper are: gr-qc
12
The categories of this paper are: nucl-th
29
The categories of this paper are: funct-an
30
The categories of this paper are: q-alg
35
The categories of this paper are: mtrl-th
20
The categories of this paper are: acc-phys
11
The categories of this paper are: hep-lat
25
The categories of this paper are: patt-sol
6
The categories of this paper are: astro-ph
1
The categories of this paper are: cs
33
The categories of this paper are: plasm-ph
34
The categories of this paper are: chem-ph
15
The categories of this paper are: nucl-ex
32
The categories of this paper are: atom-ph
14
The categories of this paper are: math-ph