The use of green sand is eliminated by replacing green sand molds with all core sand assemblies that provide, during casting, both the internal and external surfaces of a casting, such as a cylinder head or engine block. As consistent with one or more embodiments, an apparatus includes first and second sets of nanowires, in which the second set overlaps the first set. The channel detector also includes a noise prediction module coupled to the causal and anti-causal channel output module and adapted to predict noise samples based on a difference between the channel output and the causal and anti-causal channel outputs.