A method for improving the thermal stability of polyurethane-modified polyisocyanurate foams is provided. Using a thread selection policy that switches between available threads every cycle to give priority to the least recently executed or scheduled threads, different threads are able to operate in a way that ensures no deadlocks or livelocks while maximizing aggregate performance and fairness between threads. Each chevron has a compound arcuate contour both axially and laterally, and the sinuous trailing edge of the chevrons further compounds the arcuate configuration of each chevron. A pillow covering can also be provided that is longer than the foam pad such that the excess portion of the covering can be tucked under the formed foam pad to hold the pillow in its formed configuration. The second transmission and reception circuit of the read and write device receives and amplifies the inverted data signal, leading to the non-contact data communication with lower energy consumption and the lower cost. The method also includes exposing the photo-resist layer to a light source through a mask including a feature, the photo-resist layer including a floating, diffusing acid that will diffuse into a region of the photo-resist layer affected by the feature while not diffusing into a feature formed by the mask.