High-temperature radiography

Gallium, like mercury, is liquid at room temperature, but unlike mercury is much less hazardous. Its most interesting use is as a visualization tool of soft tissues and bone lesions in radiography. Industrial applications include use in high temperature thermometers, metal alloys, and as a substitute for mercury in arc lamps. 

The most imporant use of cobalt is in the manufacture of various wear-resistant and superalloys. Its alloys have shown high resistance to corrosion and oxidation at high temperatures. They are used in machine components. Also, certain alloys are used in desulfurization and hquefaction of coal and hydrocracking of crude oil shale. Cobalt catalysts are used in many industrial processes. Several cobalt salts have wide commercial apphcations (see individual salts). Cobalt oxide is used in glass to impart pink or blue color. Radioactive cobalt-60 is used in radiography and sterihzation of food. 

D. (2010) In-situ synchrotron X-ray radiography on high temperature polymer electrolyte fuel cells. Electrochem. 

J., Lehnert, W., Banhart, )., and Stolten, D. (2010) In-situ synchrotron X-ray radiography on high temperature polymer electrolyte fuel cells. Electrochem. Commun., 12, 1436. 

D.S. Hussey and D.L. Jacobson, Neutron radiography for high resolution studies in low temperature fuel cells , in Polymer electrolyte membrane and direct methanol fuel cell technology. Volume 2 In situ characterisation techniquesfor low temperature fuel cells. Ch. 7. (2012) WoodheadPubhshing, Oxford. 

Hickner et al. (2008) used high-resolution neutron radiography to image an operating PEMFC. The cross-sectional liquid water profile of the cell was quantified as a function of cell temperature, current density, and anode and cathode gas feed flow rates. At low current densities, liquid water tended to remain on the cathode side of the cell. Significant liquid water in the anode gas flow channel was observed when the heat and water production of the cell were moderate. At 60°C, the liquid water content in the center of the GDLs decreased compared to the electrolyte and catalyst layers. This profile is indicative of water condensation within the GDL and was explained by considering the microporous layers as a barrier to liquid water transport. 

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