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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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Pt(NCl)2(HgCl2)3 crystallizes in the monoclinic C2/c space group. The structure is zero-dimensional and consists of four cis-diaminedichloroplatinum molecules and twelve mercuric chloride molecules.
ZnCl2(NCl)2 crystallizes in the orthorhombic Pnma space group. The structure is zero-dimensional and consists of eight chloramine molecules and four zinc chloride molecules.
(N2)3(NCl)2 crystallizes in the orthorhombic P2_12_12_1 space group. The structure is zero-dimensional and consists of four chloramine molecules and four triazane molecules.
RhOCl2(NCl)2NCl2 crystallizes in the orthorhombic Pnma space group. The structure is zero-dimensional and consists of eight chloramine molecules, four dichloramine molecules, and four RhOCl2 clusters. In each RhOCl2 cluster, Rh3+ is bonded in a trigonal planar geometry to one O2- and two equivalent Cl1- atoms. The Rh–O bond length is 1.69 Å. Both Rh–Cl bond lengths are 2.19 Å. O2- is bonded in a single-bond geometry to one Rh3+ atom. Cl1- is bonded in a single-bond geometry to one Rh3+ atom.
(PtCl3)2N2(NO)2(NCl)4 crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of four ammonia molecules, eight chloramine molecules, four nitroxyl molecules, and four trichloroplatinum molecules.
Multipacting in accelerating structures is a complex phenomenon about which there is much to be understood. While multipacting research efforts have primarily been focused on superconducting radio frequency (SRF) systems, normal conducting accelerating structures which have a higher thermal capacity, and a greater vacuum pressure tolerance could benefit from additional investigation. This research details multipacting simulation methods and the results of 3-D electromagnetic simulations of RF vacuum windows used on normal conducting linac (NCL) cavities. Benchmarking of the peak electric fields in these structures, benefits of material processing and possible techniques for reducing or eliminating multipacting activities are discussed.
Multipacting in accelerating structures is a complex phenomenon with which there is much to be understood. While multipacting research efforts have primarily been focused on superconducting radio frequency (SRF) systems, normal conducting accelerating structures that have a higher thermal capacity and a greater vacuum pressure tolerance could benefit from additional investigation. This research details multipacting simulation methods and the results of 3-D electromagnetic simulations of RF vacuum windows used on normal conducting linac (NCL) cavities. Possible techniques for reducing and eliminating multipacting activities in these structures are discussed.
Electrocatalytic hydrogen generation requires a multifunctional electrocatalyst with abundant active sites to drive multielectron transfer reactions. High entropy alloys (HEA) are five or more-elements with high configurational entropy are considered unique materials for next-generation electrocatalysts. Here, in this work, based on new screening guidelines for catalyst selections that combine density-functional theory calculated Gibbs formation-enthalpy with bond length and electronegativity variance, a novel HEA electrocatalyst consisting of five elements, namely, Pt, Pd, Ni, Co, and Mn has been designed. By simple room temperature electrodeposition, the designed catalyst is prepared and its hydrogen evolution reaction (HER) is explored and validated through experimental and theoretical approaches. The HEA demonstrated a superior HER activity with an overpotential of 22.6 mV at -10 mA cm -2 which outperforms Pt/C commercial catalyst. No evident degradation of the material is detected even after 100 hours of continuous operation under high current density. Moreover, the HEA has shown exceptional performance in harsh electrolyte conditions such as in simulated seawater and actual seawater. Remarkably, the density-functional theory calculated Gibbs formation-enthalpy is small (≈0 eV) compared to Pt/C placing the new HEA near the apex of Trasatti's model of Volcano plot, which is also suggestive of superior HER activity.