Abstract: A carbon article having a first zone and a second zone wherein in the first zone formed from a first mix design and the second zone formed from a second mix design and the first and second mix designs have at least one difference selected from the group of differences of a presence of a certain material, a concentration of a certain material, the size of the a certain material and combinations thereof.

Abstract: A graphite-based heat exchanger, especially for use as a solar energy receptor as part of the thermal process in a solar power system, including an energy collection panel, a heat spreader, and a thermal element, wherein the heat spreader is formed of flexible graphite having a density of at least about 0.6 g/cc and a thickness of less than about 10 mm, and the heat spreader further has a first side and a second side, wherein the heat spreader is in a thermal transfer relationship with the thermal element, and wherein the energy collection panel includes at least one sheet or block of graphite.