Abstract: Gold plating baths comprising a nickel or cobalt brightener/hardener, containing oxalic acid and additionally at least one dicarboxylic acid selected from the group consisting of succinic acid, malonic acid, glutaric acid and adipic acid, enable the use of low current densities with improved efficiencies in producing bright deposits; also enable bright deposits to be obtained at high temperatures of about 150.degree. F.

Abstract: An air inflated structure, the outer shell walls of which have a surface geometry consisting of one or more concave sections. Heat flow from or into the enclosed volume is drastically curtailed by thin plastic films, which are secured to the outer boundaries of the concave surface sections, and are joined to the shell wall at locations within the boundaries of its curved surface section by direct attachment or via flexible anchor tie strips.The surface area of each film is less than that of the surface geometry encompassed within the boundary to which it is secured, whereby in its inflated state, the outer shell wall extends the films in a taut fashion across its curved surface geometries to define a thin, uniform and dimensionally stable insulating air space between the shell wall and the plastic films. Additional sets of plastic films, spaced approximately parallel, may be utilized to further curtail the said heat flow.

Abstract: A method for improving the brightness and whiteness of kaolin clays or the like. An aqueous slurry of the clay is initially treated with a solution of sodium borohydride and sodium hydroxide at a pH of above 7.0 up to about 10.0. Sulphur dioxide is then bubbled through the slurry or otherwise brought into contact with same, the pH being permitted to attain a value of between 6.0 and 7.0. The pH may thereupon be adjusted to between 2.5 and 4.0 with an acid, at which pH the leach reaction may occur; or the application of gaseous sulphur dioxide may be continued to yield a pH of the indicated 2.5 to 4.0 range.