Experimental studies from shake flasks to 3 L stirred tank bioreactor of nutrients and oxygen supply conditions to improve the growth of the avian cell line DuckCelt®-T17.

Background: To produce viral vaccines, avian cell lines are interesting alternatives to replace the egg-derived processes for viruses that do not grow well on mammalian cells. The avian suspension cell line DuckCelt-T17 was previously studied and investigated to produce a live attenuated metapneumovirus (hMPV)/respiratory syncytial virus (RSV) and influenza virus vaccines. However, a better understanding of its culture process is necessary for an efficient production of viral particles in bioreactors.

Theoretical model of ice nucleation induced by inertial acoustic cavitation. Part 2: Number of ice nuclei generated by a single bubble.

In the preceding paper (part 1), the pressure and temperature fields close to a bubble undergoing inertial acoustic cavitation were presented. It was shown that extremely high liquid water pressures but quite moderate temperatures were attained near the bubble wall just after the collapse providing the necessary conditions for ice nucleation. In this paper (part 2), the nucleation rate and the nuclei number generated by a single collapsing bubble were determined.

Theoretical model of ice nucleation induced by acoustic cavitation. Part 1: Pressure and temperature profiles around a single bubble.

This paper deals with the inertial cavitation of a single gas bubble in a liquid submitted to an ultrasonic wave. The aim was to calculate accurately the pressure and temperature at the bubble wall and in the liquid adjacent to the wall just before and just after the collapse. Two different approaches were proposed for modeling the heat transfer between the ambient liquid and the gas: the simplified approach (A) with liquid acting as perfect heat sink, the rigorous approach (B) with liquid acting as a normal heat conducting medium.

Prediction of the acoustic and bubble fields in insonified freeze-drying vials.

The acoustic field and the location of cavitation bubble are computed in vials used for freeze-drying, insonified from the bottom by a vibrating plate. The calculations rely on a nonlinear model of sound propagation in a cavitating liquid [Louisnard, Ultrason. Sonochem.