A localized heating structure includes a spectrally-selective solar absorber, that absorbs incident solar radiation and reflects at wavelengths longer than 2 m, with an underlying heat-spreading layer having a thermal conductivity equal to or greater than 50 W/(mK), a thermally insulating layer, adjacent to the spectrally-selective solar absorber, having a thermal conductivity of less than 0.1 W/(mK), one or more evaporation openings through the spectrally-selective solar absorber and the thermally insulating layer, and an evaporation wick, disposed in one or more of the evaporation openings in the thermally insulating layer, that contacts liquid and allows the liquid to be transported from a location beneath the thermally insulating layer through to the spectrally-selective solar absorber in order to generate vapor from the liquid. The thermally insulating layer is configured to have a density less than the liquid so that the localized heating structure is able to float on the liquid.

A method of forming a graphitic carbon body employs compression and resistance heating of a stock blend of a carbon material and a binder material. During molding of the body, resistance heating is accompanied by application of mechanical pressure to increase the density and carbonization of the resulting preform body. The preform can then be subjected to a graphitization temperature to form a graphite article.

One variation of a method for fabricating a dermal heatsink includes: fabricating a substrate defining an interior surface, an exterior surface opposite the interior surface, and an open network of pores extending between the interior surface and the exterior surface; activating surfaces of the substrate and walls of the open network of pores; applying a coating over the substrate to form a heatsink, the coating comprising a porous, hydrophilic material and defining a void network; removing an excess of the coating from the substrate to clear blockages within the open network of pores by the coating; hydrating the heatsink during a curing period; heating the heatsink during the curing period to increase porosity of the coating applied over surfaces of the substrate; and rinsing the heatsink with an acid to decarbonate the coating along walls of the open network of pores in the substrate.

A ceramic article includes a ceramic matrix composite that has a porous reinforcement structure and a ceramic matrix within pores of the porous reinforcement structure. The ceramic matrix composite includes a surface zone comprised of an exterior surface of the ceramic matrix composite and pores that extend from the exterior surface into the ceramic matrix composite. A glaze material seals the surface zone within the pores of the surface zone and on the exterior surface of the surface zone as an exterior glaze layer on the ceramic matrix composite. The glaze material is a glass or glass-ceramic material. The ceramic matrix composite includes an interior zone under the surface zone, and the interior zone is free of any of the glaze material and has a greater porosity than the surface zone.

A material contains open pores in which the channels and pores that are internally coated with at least one layer of phosphorus-containing alumina. Such material is formed by infiltrating a porous material one or more times with a non-colloidal, low-viscosity liquid coating precursor, drying, and curing the coating precursor to form a phosphorus-containing alumina layer within pores of the material.