Theoretical and Experimental Studies on the Ability of Intracrystalline Pores of β-La(SO) To Accommodate Various Gas Species with a Special Focus on Ammonia Insertion Behaviors.

β-La(SO) is a microporous inorganic crystal with one-dimensional perforated pores where HO molecules can be inserted. To evaluate the nature of the pores and extend the application range, we investigate the ability to accommodate various hydrogen compound molecules XH (CH, NH, HF, HS, HCl, and HI) by insertion. The stable structures of the XH molecules in the pores of β-La(SO) and the change in the Gibbs energy for XH insertion Δ () are estimated by first-principles calculations.

Experimental Study of Hydration/Dehydration Behaviors of Metal Sulfates M(SO) (M = Sc, Yb, Y, Dy, Al, Ga, Fe, In) in Search of New Low-Temperature Thermochemical Heat Storage Materials.

To identify potential low-temperature thermochemical heat storage (TCHS) materials, hydration/dehydration reactions of M(SO) (M = Sc, Yb, Y, Dy, Al, Ga, Fe, In) are investigated by thermogravimetry (TG). These materials have the same rhombohedral crystal structure, and one of them, rhombohedral Y(SO), has been recently proposed as a promising material. All M(SO)·HO hydrate/dehydrate reversibly between 30 and 200 °C at a relatively low (=0.

Multi-step hydration/dehydration mechanisms of rhombohedral Y(SO): a candidate material for low-temperature thermochemical heat storage.

To evaluate rhombohedral Y(SO) as a new potential material for low-temperature thermochemical energy storage, its thermal behavior, phase changes, and hydration/dehydration reaction mechanisms are investigated. Rhombohedral Y(SO) exhibits reversible hydration/dehydration below 130 °C with relatively small thermal hysteresis (less than 50 °C). The reactions proceed two reaction steps in approximately 0.

Discovery of Rapid and Reversible Water Insertion in Rare Earth Sulfates: A New Process for Thermochemical Heat Storage.

Thermal energy storage based on chemical reactions is a prospective technology for the reduction of fossil-fuel consumption by storing and using waste heat. For widespread application, a critical challenge is to identify appropriate reversible reactions that occur below 250 °C, where abundant low-grade waste heat and solar energy might be available. Here, it is shown that lanthanum sulfate monohydrate La (SO ) ⋅H O undergoes rapid and reversible dehydration/hydration reactions in the temperature range from 50 to 250 °C upon heating/cooling with remarkably small thermal hysteresis (<50 °C), and thus it emerges as a new candidate system for thermal energy storage.

Semiclassics of the chaotic quantum-classical transition.

We elucidate the basic physical mechanisms responsible for the quantum-classical transition in one-dimensional, bounded chaotic systems subject to unconditioned environmental interactions. We show that such a transition occurs due to the dual role of noise in regularizing the semiclassical Wigner function and averaging over fine structures in classical phase space. The results are interpreted in the context of applying recent advances in the theory of measurement and open systems to the semiclassical quantum regime.