Abstract: A concentrated solar energy system includes a photovoltaic cell, an optical concentrator, a heat removal system, and means for providing thermal contact between the photovoltaic cell and the heat removal system. The optical concentrator is configured to direct concentrated solar energy to the photovoltaic cell such that the photovoltaic cell generates electricity and heat. The heat removal system removes heat from the photovoltaic cell. The means for providing thermal contact provides an effective thermal conductivity per unit length between the photovoltaic cell and the heat removal system of greater than about 50 kilowatts per square meter per degree Celsius.

Abstract: A method for depositing a protective coating upon a substrate includes the steps of dipping a substrate into a slurry composed of an aqueous solution, at least one refractory metal oxide, and at least one transient fluid additive present in an amount of about 0.1 percent to 10 percent by weight of the slurry; heat treating the substrate; and cooling the substrate to form a protective coating thereon.

Abstract: A process of coating an article includes the steps of (1) applying upon at least one surface of an article at least one graded layer of at least one ceramic based compound comprising at least one metal selected from the group consisting of lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutelium, indium, scandium, yttrium, zirconium, hafnium, titanium, and mixtures thereof; (2) optionally drying the coated article; and (3) optionally repeating steps (1) and (2).

Abstract: An article comprising a substrate containing silicon and a barrier layer which functions as an environmental barrier coating and, more particularly, a barrier layer which comprises hafnium silicate and, optionally, zirconium silicate and a method for forming the hafnium silicate as a barrier coating.

Abstract: An article comprising a substrate containing silicon and a barrier layer which functions as an environmental barrier coating and, more particularly, a barrier layer which comprises hafnium silicate and, optionally, zirconium silicate and a method for forming the hafnium silicate as a barrier coating.