Correction for adiabatic effects in the calculated instantaneous gas consumption of scuba dives.

Introduction: In scuba-diving practice, instantaneous gas consumption is generally calculated from the fall in cylinder pressure without considering the effects of water temperature (heat transfer) and adiabatic processes. We aimed to develop a simple but precise method for calculating the instantaneous gas consumption during a dive.

Methods: With gas thermodynamics and water/gas heat transfer, the instantaneous released gas mass was modelled.

[From 1878 to 2006 - working in hyperbaric conditions during tunnelling].

To review the impact of Paul Bert's researches on hyperbaric work in tunnelling, the status of the industry in 1878 is described. Mostly based on the application of Triger's machine it was used to mine coal below the water table or to dig foundations for bridges in rivers or close to rivers. The results and conclusions obtained by Paul Bert which are applicable in that particular field are listed.