Response of Earth's atmosphere to increases in solar flux and implications for loss of water from Venus

A one-dimensional radiative-convective model is used to compute temperature and water vapor profiles as functions of solar flux for an Earth-like atmosphere. The troposphere is assumed to be fully saturated, with a moist adiabatic lapse rate, and changes in cloudiness are neglected. Predicted surface temperatures increase monotonically from -1 to 111 degrees C as the solar flux is increased from 0.81 to 1.45 times its present value. Surface temperatures corresponding to high solar fluxes may be underestimated, however, owing to neglect of H2O continuum absorption outside of the 8- to 12-micrometers window region. These results imply that the surface temperature of a primitive water-rich Venus should have been at least 80-100 degrees C and may have been much higher. The existence of liquid water at the surface depends on poorly known aspects of H2O continuum absorption and on uncertainties concerning relative humidity and cloudiness. In any case, water vapor should have been a major atmospheric constituent at all altitudes, leading to the rapid hydrodynamic escape of hydrogen. The oxygen left behind by this process was presumably consumed by reactions with reduced minerals in the crust. Both the loss of oxygen and the presently observed enrichment of the deuterium-to-hydrogen ratio are most easily explained if oceans of liquid water were initially present.

Indicator Dispersal by Convection and Diffusion in Fluid Flow Through a Tube

A tube is filled with water containing indicator and then the indicator is washed out by laminar flow of indicator-free water. Given a measurement of mean volume concentration of indicator in the effluent as a function of time, a theoretical expression is derived for the pattern of indicator delivery in the case where diffusion is superimposed on convective transport. Satisfactory experimental verification of the theoretical expressions was obtained.

Protein Purification by Elution Convection Electrophoresis

Purified protein components can be recovered from high-resolution gel-electrophoresis patterns by elution-convection electrophoresis. The protein components are all simultaneously eluted from the gel pattern by horizontal electrophoresis and are then simultaneously concentrated by electro-convection to recover the proteins in nearly the original sample concentration. Thirty individual protein fractions can be recovered in 3 hours from a sample containing 200 milligrams of protein.