Optical Investigations of Film Formation and Removal on Gold Anodes in Acidic Oxalate Solutions
RECENT investigations of the oxidation of oxalate ions in acidic solutions using gold anodes have provided electrochemical evidence for the formation of a film on this anode during steady-state electrolysis at potentials well below that for Au2O3 formation, 1.36 V normal hydrogen electrode1. The determination of the nature of the film on gold at potentials below 1.36 V using electrochemical techniques has introduced uncertainties as to whether the film is a ‘three dimensional’ oxide film or a ‘two dimensional’ chemisorbed oxygen film. Some investigators2–5 using charging curves as their basis conclude that the formation of an oxide occurs only above 1.36 V, the formation of a chemisorbed oxygen film being the process occurring below this potential. The formation of this chemisorbed oxygen film begins at potentials as low as 1 15 V (ref. 6). Other work, however, also based on electrochemical evidence, indicates that the formation of an oxide film does occur below 1.36 V (ref. 7).
In Situ Measurement of Electrode Surface Change by Photoacoustic Spectroscopy
Photoacoustic spectroscopy (PAS) was used for the study of electrode-electrolyte interfaces in situ. The design of the PAS cell and the experimental procedure are given. The change in absorption at the interface during electrochemical reaction at Au electrodes, as measured by PAS technique, is described.
Calculation of Complex Radiant Heat Load From Surrounding Radiator Surface Temperatures
Abstract A method for calculating the radiant heat exchange between an absorber and individual radiating components in its surroundings is reported. Radiator surface temperatures, ambient and absorber temperatures, and configuration factors for radiating components in the surroundings are used in the customary radiant heat exchange formulae. Simplified methods for calculating or estimating configuration factors for radiators of various shapes solely from angles, subtended at the absorber by the radiators are presented. The method has been verified in the laboratory under controlled conditions and has been used to advantage in the field studies. The method has advantages over the globe therometer method in certain applications.