Abstract: This invention relates to a method for sealing porosity of at least a portion of an outer porous surface of an article, said method comprising (i) applying a sealant solution on the outer porous surface of said article, (ii) infiltrating at least a portion of the outer porous surface with said sealant solution, and (iii) allowing the infiltrated sealant solution to react, thereby forming an infiltrated solid precipitate, said infiltrated solid precipitate sealing the porosity of at least a portion of the outer porous surface of said article. The method is useful, for example, in the protection of integrated circuit manufacturing equipment, internal chamber components, and electrostatic chuck manufacture.

Abstract: According to the invention, an improved hinge is provided for use with a food service cart of the pass through design. Opposite sides of the cart defining the access openings are sealed by pivoting doors which open towards each other and against a common endwall. One of the doors is hinged in conventional manner as by the use of pairs of cooperating, vertically spaced brackets and hinge pins. A pin is pivoted in a portion of each bracket extending beyond the common endwall so that the one door can be swung through a 270.degree. range to seat flushly against the endwall. The invention contemplates the provision of a lengthened bracket associated with the door opposite the first door. The second door is pivoted about a point further from the plane of the endwall than the pivot on the first door. The second door can thus be folded in parallel, overlapping relationship with the first door whereas it would otherwise interfere with the corner at the free end of the first door.