18,754 research outputs found
La recerca en enginyeria química a Europa
Una de les ponències de la reunió de Prada-82 sobre recerca experimental en física i químic
The Katětov construction modified for a T0-quasi-metric space
AbstractWe discuss the existence and uniqueness of a T0-quasi-metric space qU defined by the following three conditions: (i) qU is bicomplete and supseparable, (ii) every isometry between two finite subspaces of qU extends to an isometry of qU onto itself, and (iii) qU contains an isometric copy of every supseparable T0-quasi-metric space
Remarks on -monotone operators
In this paper, we deal with three aspects of -monotone operators. First we
study -monotone operators with a unique maximal extension (called
pre-maximal), and with convex graph. We then deal with linear operators, and
provide characterizations of -monotonicity and maximal -monotonicity.
Finally we show that the Brezis-Browder theorem preserves -monotonicity in
reflexive Banach spaces.Comment: 15 page
On a Dynamical-Like Replica-Symmetry-Breaking Scheme for the Spin Glass
Considering the unphysical result obtained in the calculation of the
free-energy cost for twisting the boundary conditions in a spin glass, we trace
it to the negative multiplicities associated with the Parisi replica-symmetry
breaking (RSB). We point out that a distinct RSB, that keeps positive
multiplicities, was proposed long ago, in the spirit of an ultra-long time
dynamical approach due to Sompolinsky. For an homogeneous bulk system, both RSB
schemes are known to yield identical free energies and observables. However,
using the dynamical RSB, we have recalculated the twist free energy at the
mean-field level. The free-energy cost of this twist is, as expected, positive
in that scheme, as it should be
Cylindrical Wiener processes
In this work cylindrical Wiener processes on Banach spaces are defined by
means of cylindrical stochastic processes, which are a well considered
mathematical object. This approach allows a definition which is a simple
straightforward extension of the real-valued situation. We apply this
definition to introduce a stochastic integral with respect to cylindrical
Wiener processes. Again, this definition is a straightforward extension of the
real-valued situation which results now in simple conditions on the integrand.
In particular, we do not have to put any geometric constraints on the Banach
space under consideration. Finally, we relate this integral to well-known
stochastic integrals in literature
Effects of liquid and vapor cesium on structural materials
Literature survey on corrosive effects of liquid and vapor cesium on structural materials, and compatibility of cesium as working fluid for Rankine cycle space power plan
Simulating spin-charge separation with light
In this work we show that stationary light-matter excitations generated
inside a hollow one-dimensional waveguide filled with atoms, can be made to
generate a photonic two-component Lieb Liniger model. We explain how to prepare
and drive the atomic system to a strongly interacting regime where spin-charge
separation could be possible. We then proceed by explaining how to measure the
corresponding effective spin and charge densities and velocities through
standard optical methods based in measuring dynamically the emitted photon
intensities or by analyzing the photon spectrum. The relevant interactions
exhibit the necessary tunability both to generate and efficiently observe spin
charge separation with current technology.Comment: 4 pages. Comments welcom
Liquid drop technique for generation of organic glass and metal shells
It was found that liquid drop techniques are very useful in several diverse areas. For producing very uniform metallic, organic, inorganic and, on particular, glassy shells, the liquid jet method is the most reproducible and exceptionally useful of all the techniques studied. The technique of capillary wave synchronization of the break-up of single and multiple component jets was utilized to produce uniform sized liquid drops and solid particles, and hollow liquid and solid shells. The technique was also used to encapsulate a number of liquids in impermeable spherical shells. Highly uniform glass shells were made by generating uniform drops of glass forming materials in an aqueous solution, subsequently evaporating the water, and then fusing and blowing the remaining solids in a high temperature vertical tube furnace. Experimental results are presented and the critical problems in further research in this field are discussed
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