The Onsager heat of transport for p-tert-butyltoluene was measured, as part of a series of preliminary experiments towards the determination of the importance of temperature gradients on the air-sea flux of carbon dioxide. The results presented in this thesis imply that the temperature gradient is a major contributor to the magnitude of the air-sea flux. The heat of transport has been measured for the p-tert-butyltoluene system by measuring stationary-state pressure changes for known temperature differences on the vapour side of the interface. At the pressure ranges used the number of mean free paths was always outside the Knudsen zone, but the values of Q* were approximately 100 % of the latent heat of vaporisation. Departures from linearity of plots of P against ΔT are attributed to temperature jumps at the surface of the dry upper plate. Both the results taken for p-tert-butyltoluene and the earlier results for water from this laboratory fit to a Type III BET isotherm, where the c parameter is not constant. They also reveal the importance of the temperature gradient in determining the value of the thermal accommodation coefficient, and provide a new method of measuring thermal accommodation coefficients for a variety of surfaces and vapours

The Onsager heat of transport for p-tert-butyltoluene was measured, as part of a series of preliminary experiments towards the determination of the importance of temperature gradients on the air-sea flux of carbon dioxide. The results presented in this thesis imply that the temperature gradient is a major contributor to the magnitude of the air-sea flux. The heat of transport has been measured for the p-tert-butyltoluene system by measuring stationary-state pressure changes for known temperature differences on the vapour side of the interface. At the pressure ranges used the number of mean free paths was always outside the Knudsen zone, but the values of Q* were approximately 100 % of the latent heat of vaporisation. Departures from linearity of plots of P against ΔT are attributed to temperature jumps at the surface of the dry upper plate. Both the results taken for p-tert-butyltoluene and the earlier results for water from this laboratory fit to a Type III BET isotherm, where the c parameter is not constant. They also reveal the importance of the temperature gradient in determining the value of the thermal accommodation coefficient, and provide a new method of measuring thermal accommodation coefficients for a variety of surfaces and vapours