1,063 research outputs found
Quantum depletion of collapsing Bose-Einstein condensates
We perform the first numerical three-dimensional studies of quantum field
effects in the Bosenova experiment on collapsing condensates by E. Donley et
al. [Nature 415, 39 (2002)] using the exact experimental geometry. In a
stochastic truncated Wigner simulation of the collapse, the collapse times are
larger than the experimentally measured values. We find that a finite
temperature initial state leads to an increased creation rate of uncondensed
atoms, but not to a reduction of the collapse time. A comparison of the
time-dependent Hartree-Fock-Bogoliubov and Wigner methods for the more
tractable spherical trap shows excellent agreement between the uncondensed
populations. We conclude that the discrepancy between the experimental and
theoretical values of the collapse time cannot be explained by Gaussian quantum
fluctuations or finite temperature effects.Comment: 9 pages, 4 figures, replaced with published versio
A Novel Biomanufacturing System to Produce Multi-Material Scaffolds for Tissue Engineering: Concept and Preliminary Results
This research work aims to validate a new system that enables the fabrication of multimaterial 3D structures using poly(e-caprolactone) and sodium alginate for potential use in Tissue Engineering applications. To produce multi-material scaffolds for Tissue Engineering, accurate techniques are needed to obtain three-dimensional constructs with clinically appropriate size and structural integrity. This paper presents a novel biomanufacturing system which can fabricate 3D scaffolds with precise shape and porosity, through the control of all fabrication modules by an integrated computational platform. The incorporation of a clean flow unit and a camera makes it possible to produce scaffolds in a clean environment and provides a monitoring tool to analyse
constructs during the production, respectively.info:eu-repo/semantics/publishedVersio
New Shape Invariant Potentials in Supersymmetric Quantum Mechanics
Quantum mechanical potentials satisfying the property of shape invariance are
well known to be algebraically solvable. Using a scaling ansatz for the change
of parameters, we obtain a large class of new shape invariant potentials which
are reflectionless and possess an infinite number of bound states. They can be
viewed as q-deformations of the single soliton solution corresponding to the
Rosen-Morse potential. Explicit expressions for energy eigenvalues,
eigenfunctions and transmission coefficients are given. Included in our
potentials as a special case is the self-similar potential recently discussed
by Shabat and Spiridonov.Comment: 8pages, Te
Ballistic deposition patterns beneath a growing KPZ interface
We consider a (1+1)-dimensional ballistic deposition process with
next-nearest neighbor interaction, which belongs to the KPZ universality class,
and introduce for this discrete model a variational formulation similar to that
for the randomly forced continuous Burgers equation. This allows to identify
the characteristic structures in the bulk of a growing aggregate ("clusters"
and "crevices") with minimizers and shocks in the Burgers turbulence, and to
introduce a new kind of equipped Airy process for ballistic growth. We dub it
the "hairy Airy process" and investigate its statistics numerically. We also
identify scaling laws that characterize the ballistic deposition patterns in
the bulk: the law of "thinning" of the forest of clusters with increasing
height, the law of transversal fluctuations of cluster boundaries, and the size
distribution of clusters. The corresponding critical exponents are determined
exactly based on the analogy with the Burgers turbulence and simple scaling
considerations.Comment: 10 pages, 5 figures. Minor edits: typo corrected, added explanation
of two acronyms. The text is essentially equivalent to version
Satellite potentials for hypergeometric Natanzon potentials
As a result of the so(2,1) of the hypergeometric Natanzon potential a set of
potentials related to the given one is determined. The set arises as a result
of the action of the so(2,1) generators.Comment: 9 page
The Spectrum of Sl(2, R)/U(1) Black Hole Conformal Field Theory
We study string theory in the background of a two-dimensional black hole
which is described by an coset conformal field theory. We
determine the spectrum of this conformal field theory using supersymmetric
quantum mechanics and give an explicit form of the vertex operators in terms of
the Jacobi functions. We also discuss the applicability of SUSY quantum
mechanics techniques to non-linear -models.Comment: 21 page
The synthesis and properties of the phases obtained by solid-solid reactions
The presented work encompasses the subject of the studies and the results obtained over the last years by the research workers of the Department of Inorganic Chemistry. They include mainly the studies on the reactivity of metal oxides, searching for new phases in binary and ternary systems of metal oxides as well as describing phase relations establishing in such systems. They also encompass works on the extensive characteristics of physico-chemical properties of the newly obtained compounds
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