Respiratory Particle Deposition Probability due to Sedimentation with Variable Gravity and Electrostatic Forces

TL;DR

This study analyzes how variable gravity and electrostatic forces influence respiratory particle deposition probabilities on Earth, Mars, and spacecraft orbits, revealing spatial and orbital variations with implications for biology and space health.

Contribution

It introduces a novel framework considering sedimentation probability as a Shannon information variable, linking gravity effects to biological and cognitive processes.

Findings

Higher deposition probabilities at Earth's poles for 1 μm particles.

Orbit inclination affects deposition probabilities, with equatorial orbits showing higher rates.

Deposition probability increases with particle size and orbital eccentricity.

Abstract

In this paper, we study the effects of the acceleration gravity on the sedimentation deposition probability, as well as the aerosol deposition rate on the surface of the Earth and Mars, but also aboard a spacecraft in orbit around Earth and Mars as well for particles with density rho_p = 1300 kg/m^3, diameters d_p = 1, 3, 5 micrometers and residence times t = 0.0272, 0.2 s respectively. For particles of diameter 1 micrometer we find that, on the surface of Earth and Mars the deposition probabilities are higher at the poles when compared to the ones at the equator. Similarly, on the surface of the Earth we find that the deposition probabilities exhibit 0.5% and 0.4% higher percentage difference at the poles when compared to that of the equator, for the corresponding residence times. Moreover in orbit equatorial orbits result to higher deposition probabilities when compared to polar ones. For both residence times particles with the diameters considered above in circular and elliptical orbits around Mars, the deposition probabilities appear to be the same for all orbital inclinations. Sedimentation probability increases drastically with particle diameter and orbital eccentricity of the orbiting spacecraft. Finally, as an alternative framework for the study of interaction and the effect of gravity in biology, and in particular gravity and the respiratory system we introduce is the term information in a way Shannon has introduced it, considering the sedimentation probability as a random variable. This can be thought as a way in which gravity enters the cognitive processes of the system (processing of information) in the cybernetic sense.