Elsevier Science Home
Computer Physics Communications Program Library
Full text online from Science Direct
Programs in Physics & Physical Chemistry
CPC Home

[Licence| Download | New Version Template] aafo_v1_0.gz(3 Kbytes)
Manuscript Title: DECOMP: computational package for nitrogen transport modelling in tissues.
Authors: B.R. Wienke
Program title: DECOMP
Catalogue identifier: AAFO_v1_0
Distribution format: gz
Journal reference: Comput. Phys. Commun. 40(1986)327
Programming language: Fortran.
Computer: CRAY 1S.
Operating system: CTSS.
RAM: 400K words
Word size: 64
Peripherals: graph plotter.
Keywords: Fluid dynamics, Nitrogen transport, Decompression criteria, Multi-tissue models.
Classification: 12.

Nature of problem:
DECOMP models multi-tissue nitrogen transport in divers breathing compressed air (80 per cent N2 and 20 per cent O2). Repetitive and multi-level (depth and time) activities are traced continuously in time. Computed nitrogen pressures are compared with critical values used to fabricate the U.S. Navy air tables. Extrapolation of critical nitrogen pressures to altitude is effected with an exponential barometer equation for air. Critical ratios (nitrogen pressure/ambient pressure) are also tabulated.

Solution method:
DECOMP employs analytic solutions to the bulk diffusion equations to predict nitrogen tensions in tissues of arbitrary half-life. In repetitive, multi-level applications, continuous tensions at the end of one stage form the initial values for the following stage. Ascent, or descent, rates can be used with an averaging technique to transport nitrogen between stages. The diffusion equation used to transport nitrogen treats tissues as uniform (bulk) media.

Running time:
Calculations for six tissues in a 10 level excursion require less than a second.