NASA Scientific and Technical Aerospace Reports

A critical analysis of the CCSD(T) (’coupled cluster single and doubles with perturbative triples’) method is presented.
This method is widely regarded as possibly the best balance between efficiency and accuracy. It includes an a posteriori
pertubative correction to the CCSD method for terms associated with triply excited intermediate states which can support
‘chemical accuracy.’ However, the CCSD method and the augmented theory CCSD(T) fails in the presence of
quasidegeneracy. Recent work has shown that multireference methods give more accurate results in studies of systems in
which some degree of quasidegeneracy is present. Nevertheless there is continued interest in extending the range of
applicability of single reference augmented coupled cluster methods such as CCDSD(T). Renormalized CCSD(T) theory,
which is based on the method such as CCSD(T). Renormalized CCSD(T) theory, which is based on the method of moments
coupled cluster theory, is claimed to be a promising approach which removes the pervasive failing of the standard CCSD(T)
method but destroys its ‘extensivity’ property.
NTIS
Clusters; Computation; Method of Moments
20040070728 NASA Lewis Research Center, Cleveland, OH, USA
The Nickel(111)/Alkaline Electrolyte Interface
Wang, Kuilong; Chottiner, G. S.; Scherson, D. A.; Reid, Margaret A.; Space Electrochemical Research and Technology:
Abstracts; [1991], pp. 11; In English; See also 20040070726; No Copyright; Available from CASI only as part of the entire
parent document
The electrochemical properties of Ni (111) prepared and characterized in ultra high vacuum, UHV, by surface analytical
techniques have been examined in alkaline media by cyclic voltammetry using an UHV-electrochemical cell transfer system
designed and built in this laboratory. Prior to the transfer, the Ni(111) surfaces were exposed to saturation coverages of CO
in UHV in an attempt to protect the surface from possible contamination with other gases during the transfer.
Author
Nickel; Surface Properties; Electrochemical Cells
20040070729 NASA Lewis Research Center, Cleveland, OH, USA
Impedances of Nickel Electrodes Cycled in Various KOH Concentrations
Reid, Margaret A.; Loyselle, Patricia L.; Space Electrochemical Research and Technology: Abstracts; [1991], pp. 19; In
English; See also 20040070726; No Copyright; Available from CASI only as part of the entire parent document
Impedances were measured of electrodes from boiler-plate cells cycled i n KOH concentrations from 21% to 36 %. These
cells under accelerated conditions at 80% DOD to failure, defined discharge voltage. Cell life ranged from about 1,000 t o 40
impedances were measured at five voltages corresponding to charge. The results were analyzed using a standard circuit model
including a Warburg impedance term.
Author
Nickel; Electric Potential
20040070731 Hamilton Standard, Windsor Locks, CT, USA
SPE Water Electrolyzers in Support of Mission from Planet Earth
McElroy, J. F.; Space Electrochemical Research and Technology: Abstracts; [1991], pp. 5-6; In English; See also
20040070726; No Copyright; Available from CASI only as part of the entire parent document
During the 1970’s the SPE Water Electrolyzer, which uses ion exchange membranes as its sole electrolyte, was developed
for nuclear submarine metabolic oxygen production. These developments included SPE water electrolyzer operation at up to
3000 psia and at current densities in excess of 1000 amps per square foot. SPE water electrolyzer systems are now fully
qualified for both U.S. and U.K. Navies with tens of thousands of system hours accumulated at sea. During the 1980’s the
basic SPE water electrolyzer cell structure developed for the Navies was incorporated into several demonstrators for NASA’s
Space Station Program. Among these were SPE regenerative fuel cell for electrical energy storage; and SPE water electrolyzer
for metabolic oxygen production. An overview of these programs will be provided. High Pressure SPE water electrolyzer for
reboost propulsion reactant production Details of construction and performance of these demonstrators will be provided.
Author
Electrolysis; Regenerative Fuel Cells; Oxygen Production
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