Abstract:
A polymeric material having a negative photoelastic constant. The polymeric material comprises: (a) a polymer comprising polymerized units of 2-vinylpyridine, 4-vinylpyridine, methyl methacrylate or a combination thereof; (b) a C9-C25 aliphatic polycyclic compound; and (c) an organic compound having a boiling point of at least 200° C.
Abstract:
A magnetocaloric cascade contains a sequence of magnetocaloric material layers having different Curie temperatures TC, wherein the magnetocaloric material layers include a cold-side outer layer, a hot-side outer layer and at least three inner layers between the cold-side outer layer and the hot-side outer layer, and each pair of next neighboring magnetocaloric layers of the magnetocaloric cascade has a respective Curie-temperature difference amount ΔTC between their respective Curie temperatures, wherein the hot-side outer layer or the cold-side outer layer or both the hot-side and cold-side outer layer exhibits a larger ratio mΔSmax/ΔTC in comparison with any of the inner layers, m denoting the mass of the respective magnetocaloric material layer and ΔSmax denoting a maximum amount of isothermal magnetic entropy change achievable in a magnetic phase transition of the respective magnetocaloric material layer.