11. In convection, the energy transfer through the flow field is both by thermal diffusion and enthalpy flow. 12. The thermal diffusion effort continued, however. 13. In February 1945, slightly enriched 1.4 percent uranium-235 feed material began arriving from the S-50 liquid thermal diffusion plant. 14. "' Thermal transpiration "'or "'thermal diffusion "'refers to the thermal force on a gas due to a temperature difference. 15. In the Naval Laboratory Philip Abelson developed the liquid thermal diffusion technique for separating U-235 for the Manhattan Project. 16. Thermal diffusion was not initially regarded as very promising, but Gunn was impressed by Philip Abelson's efforts on it.17. Figure D shows three different regions : the tunneling region, the negative differential resistance region and the thermal diffusion region. 18. The thermal diffusion length ( the distance the heat spreads ) is inversely proportional to the root of the modulation frequency. 19. In February the Alpha racetracks began receiving slightly enriched ( 1.4 % ) feed from the new S-50 thermal diffusion plant. 20. At Liverpool they focused on the separation of isotopes through thermal diffusion as was suggested in the Frish / Peierls memorandum.
