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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 559 records · Page 31
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Synthesis and magnetic performance of gadolinium powder produced with rotating disk atomization

Spherical powder is key for achieving good heat transfer and maintaining low pressure drop for heat transfer fluid in magnetocaloric regenerator. Obtaining relatively large spherical powder of rare earth metals that are extremely sensitive to oxygen is challenging. Comparing to gas atomization and plasma rotating electrode methods, rotating disk atomization (RDA) method is more robust for obtaining a small amount of powder with a short turn-around time, thereby, more suitable for research and development of new magnetocaloric materials. In this work, commercially bulk gadolinium was successfully atomized to produce spherical powder in the targeted 150–250 μm range. The obtained powder exhibited the expected magnetocaloric performance with a maximum change of magnetic entropy of 12.1 J/kg K and a maximum adiabatic temperature change of 12.8 K with an applied magnetic field of 7 T.

36 MATERIALS SCIENCE↗
DOE OSTI2016

Synthesis and structural characterization of a flexible metal organic framework {[Ni(dpbz)][Ni(CN 4 ]} n , dpbz = 1,4-bis(4-pyridyl)benzene) with an unusual Ni-N bond

The chartreuse monoclinic Ni-dpbz (Ni(L)[Ni(CN) 4 ], (L = 1,4-Bis(4-pyridyl)benzene, or dpbz) crystal assumes a pillared structure with layers defined by 2-D Ni[Ni(CN) 4 ] n nets and dpbz ligands as pillars, linking between coordinated Ni sites. In addition to the hysteretic adsorption/desorption feature of Ni-dpbz, in half of the parallelepiped-shape space enclosed by the pillars and nets, an additional dpbz ligand was found to link between the open ends of two four-fold Ni sites. This arrangement results in an unusual 5-fold pseudo square-pyramid environment for Ni and a significantly long Ni–N distance of 2.369(4) Å. The presence of disordered dimethyl sulfoxide (DMSO) solvent molecules give rise to the formula of Ni(dpbz)[Ni(CN) 4 ]·½dpbz·0.44DMSO. Sorption isotherms showed flexible behavior during the adsorption and desorption of CO 2 .

Wong-Ng, Winnie↗