9,146 research outputs found
Nongassing NiCd battery cell
Method of constructing nickel cadmium batteries prevents excessive gas buildup and allows hermetic sealing of battery for increased service life and reduced maintenance cost
Several new catalysts for reduction of oxygen in fuel cells
Test results prove nickel carbide or nitride, nickel-cobalt carbide, titanium carbide or nitride, and intermetallic compounds of the transition or noble metals to be efficient electrocatalysts for oxygen reduction in alkaline electrolytes in low temperature fuel cells
Scalable Text and Link Analysis with Mixed-Topic Link Models
Many data sets contain rich information about objects, as well as pairwise
relations between them. For instance, in networks of websites, scientific
papers, and other documents, each node has content consisting of a collection
of words, as well as hyperlinks or citations to other nodes. In order to
perform inference on such data sets, and make predictions and recommendations,
it is useful to have models that are able to capture the processes which
generate the text at each node and the links between them. In this paper, we
combine classic ideas in topic modeling with a variant of the mixed-membership
block model recently developed in the statistical physics community. The
resulting model has the advantage that its parameters, including the mixture of
topics of each document and the resulting overlapping communities, can be
inferred with a simple and scalable expectation-maximization algorithm. We test
our model on three data sets, performing unsupervised topic classification and
link prediction. For both tasks, our model outperforms several existing
state-of-the-art methods, achieving higher accuracy with significantly less
computation, analyzing a data set with 1.3 million words and 44 thousand links
in a few minutes.Comment: 11 pages, 4 figure
Extreme thermopower anisotropy and interchain transport in the quasi-one-dimensional metal Li(0.9)Mo(6)O(17)
Thermopower and electrical resistivity measurements transverse to the
conducting chains of the quasi-one-dimensional metal Li(0.9)Mo(6)O(17) are
reported in the temperature range 5 K = 400 K the
interchain transport is determined by thermal excitation of charge carriers
from a valence band ~ 0.14 eV below the Fermi level, giving rise to a large,
p-type thermopower that coincides with a small, n-type thermopower along the
chains. This dichotomy -- semiconductor-like in one direction and metallic in a
mutually perpendicular direction -- gives rise to substantial transverse
thermoelectric (TE) effects and a transverse TE figure of merit among the
largest known for a single compound.Comment: PRL in press, manuscript (5pp, 4 Fig.'s) and Supplementary Material
(3pp, 3 Fig.'s
Ballistic magnon heat conduction and possible Poiseuille flow in the helimagnetic insulator CuOSeO
We report on the observation of magnon thermal conductivity 70
W/mK near 5 K in the helimagnetic insulator CuOSeO, exceeding that
measured in any other ferromagnet by almost two orders of magnitude. Ballistic,
boundary-limited transport for both magnons and phonons is established below 1
K, and Poiseuille flow of magnons is proposed to explain a magnon mean-free
path substantially exceeding the specimen width for the least defective
specimens in the range 2 K 10 K. These observations establish
CuOSeO as a model system for studying long-wavelength magnon dynamics.Comment: 10pp, 9 figures, accepted PRB (Editor's Suggestion
Big brother is watching - using digital disease surveillance tools for near real-time forecasting
Abstract for the International Journal of Infectious Diseases 79 (S1) (2019).https://www.ijidonline.com/article/S1201-9712(18)34659-9/abstractPublished versio
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