62 research outputs found
Rheology of supersaturated sucrose solutions
Sucrose solutions, with concentrations near or superior to saturation, present high potentialities for the candy and pastry industries.
Creep measurements under small stresses were done to obtain the rheological properties of highly concentrated sucrose solutions, since
such solutions could be in a metastable state and tend to crystallise. The viscosities of these solutions, from 70.0% to 85.2% (w/w), were
determined experimentally at different temperatures, from 0 to 90 C. The temperature dependence of viscosity was studied using experimental
and published data for, respectively, high and low concentrations (<70% (w/w)). Results showed that the Arrhenius model
describes better the temperature dependence of viscosity for concentrations under saturation and in the high concentration regime
the WLF model had a better predicting ability. The effect of concentration on viscosity was observed and included in the Arrhenius
and WLF models parameters. The proposed models were able to successfully describe the data in the corresponding concentration
range. These results can be used in predicting the viscosities of syrups for either process design or new products formulation
Faithful Squashed Entanglement
Squashed entanglement is a measure for the entanglement of bipartite quantum
states. In this paper we present a lower bound for squashed entanglement in
terms of a distance to the set of separable states. This implies that squashed
entanglement is faithful, that is, strictly positive if and only if the state
is entangled. We derive the bound on squashed entanglement from a bound on
quantum conditional mutual information, which is used to define squashed
entanglement and corresponds to the amount by which strong subadditivity of von
Neumann entropy fails to be saturated. Our result therefore sheds light on the
structure of states that almost satisfy strong subadditivity with equality. The
proof is based on two recent results from quantum information theory: the
operational interpretation of the quantum mutual information as the optimal
rate for state redistribution and the interpretation of the regularised
relative entropy of entanglement as an error exponent in hypothesis testing.
The distance to the set of separable states is measured by the one-way LOCC
norm, an operationally-motivated norm giving the optimal probability of
distinguishing two bipartite quantum states, each shared by two parties, using
any protocol formed by local quantum operations and one-directional classical
communication between the parties. A similar result for the Frobenius or
Euclidean norm follows immediately. The result has two applications in
complexity theory. The first is a quasipolynomial-time algorithm solving the
weak membership problem for the set of separable states in one-way LOCC or
Euclidean norm. The second concerns quantum Merlin-Arthur games. Here we show
that multiple provers are not more powerful than a single prover when the
verifier is restricted to one-way LOCC operations thereby providing a new
characterisation of the complexity class QMA.Comment: 24 pages, 1 figure, 1 table. Due to an error in the published
version, claims have been weakened from the LOCC norm to the one-way LOCC
nor
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