8,931 research outputs found
Copper chloride cathode for a secondary battery
Higher energy and power densities are achieved in a secondary battery based on molten sodium and a solid, ceramic separator such as a beta alumina and a molten catholyte such as sodium tetrachloroaluminate and a copper chloride cathode. The higher cell voltage of copper chloride provides higher energy densities and the higher power density results from increased conductivity resulting from formation of copper as discharge proceeds
Organic cathode for a secondary battery
A liquid catholyte for a battery based on liquid metal such as sodium anode and a solid, ceramic separator such as beta alumina (BASE) comprises a mixture of a Group I-III metal salt such as sodium tetrachloroaluminate and a minor amount of an organic carbonitrile depolarizer having at least one adjacent ethylenic band such as 1 to 40 percent by weight of tetracyanoethylene. The tetracyanoethylene forms an adduct with the molten metal salt
The atomic orbitals of the topological atom
The effective atomic orbitals have been realized in the framework of Bader’s atoms in molecules theory for a general wavefunction. This formalism can be used to retrieve from any type of calculation a
proper set of orthonormalized numerical atomic orbitals, with occupation numbers that sum up to the
respective Quantum Theory of Atoms in Molecules (QTAIM) atomic populations. Experience shows
that only a limited number of effective atomic orbitals exhibit significant occupation numbers. These
correspond to atomic hybrids that closely resemble the core and valence shells of the atom. The
occupation numbers of the remaining effective orbitals are almost negligible, except for atoms with
hypervalent character. In addition, the molecular orbitals of a calculation can be exactly expressed
as a linear combination of this orthonormalized set of numerical atomic orbitals, and the Mulliken
population analysis carried out on this basis set exactly reproduces the original QTAIM atomic populations of the atoms. Approximate expansion of the molecular orbitals over a much reduced set of
orthogonal atomic basis functions can also be accomplished to a very good accuracy with a singular
value decomposition procedure
High-throughput synthesis of thermoelectric CaCoO films
Properties of complex oxide thin films can be tuned over a range of values as
a function of mismatch, composition, orientation, and structure. Here, we
report a strategy for growing structured epitaxial thermoelectric thin films
leading to improved Seebeck coefficient. Instead of using single-crystal
sapphire substrates to support epitaxial growth, CaCoO films are
deposited, using the Pulsed Laser Deposition technique, onto AlO
polycrystalline substrates textured by Spark Plasma Sintering. The structural
quality of the 2000 \AA thin film was investigated by Transmission Electron
Microscopy, while the crystallographic orientation of the grains and the
epitaxial relationships were determined by Electron Back Scatter Diffraction.
The use of a polycrystalline ceramic template leads to structured films that
are in good local epitaxial registry. The Seebeck coefficient is about 170
V/K at 300 K, a typical value of misfit material with low carrier density.
This high-throughput process, called combinatorial substrate epitaxy, appears
to facilitate the rational tuning of functional oxide films, opening a route to
the epitaxial synthesis of high quality complex oxides.Comment: Submitted to Applied Physics Letters (2013
Total variation denoising in anisotropy
We aim at constructing solutions to the minimizing problem for the variant of
Rudin-Osher-Fatemi denoising model with rectilinear anisotropy and to the
gradient flow of its underlying anisotropic total variation functional. We
consider a naturally defined class of functions piecewise constant on
rectangles (PCR). This class forms a strictly dense subset of the space of
functions of bounded variation with an anisotropic norm. The main result shows
that if the given noisy image is a PCR function, then solutions to both
considered problems also have this property. For PCR data the problem of
finding the solution is reduced to a finite algorithm. We discuss some
implications of this result, for instance we use it to prove that continuity is
preserved by both considered problems.Comment: 34 pages, 9 figure
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