I compare gas-dynamical and stellar-dynamical models of collisions. These two models have distinctly different physics; for example , shocks introduce irreversibility in gas systems, while stellar systems evolve in a completely reversible fashion. Nonetheless, both models yield broadly similar results, suggesting that analogies between gas and stellar dynamics have some heuristic validity even ...

We report the modeling results of an all-fiber gas detector that uses photonic crystal fiber (PCF). The relative sensitivity of the PCF as a function of the fiber parameters is calculated. Gas-diffusion dynamics that affect the sensor response time is investigated theoretically and experimentally. A practical PCF sensor aiming for high sensitivity gas detection is proposed.

Motivated by a recent experiment (CATANI J. et at., Phys. Rev. A, 85 (2012) 023623) we study breathing oscillations in the width of a harmonically trapped impurity interacting with a separately trapped Bose gas. We provide an intuitive physical picture of such dynamics at zero temperature, using a time-dependent variational approach. The amplitudes of breathing oscillations are suppressed by se...

We investigate in this paper the effect of gas drag on the dynamics of the dust particles in the edge-on β Pictoris disc in order to derive an upper limit on the mass of gas in this system. Our study is motivated by the large uncertainties on the amount of gas in the β Pictoris disc currently found in the literature. The dust particles are assumed to originate from a colliding annulus of planet...

The influence of gas-surface interactions of a dilute gas confined between two parallel walls on the heat flux predictions is investigated using a combined Monte Carlo (MC) and molecular dynamics (MD) approach. The accommodation coefficients are computed from the temperature of incident and reflected molecules in molecular dynamics and used as effective coefficients in Maxwell-like boundary con...