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Your search keyword '"Stassinopoulos, A"' showing total 3 results
Start Over Author "Stassinopoulos, A" Publisher american institute of physics
3 results on '"Stassinopoulos, A"'

1. Laser-Like Emission From Highly Scattering ZnO Nanoparticle Films.

Author

Stassinopoulos, A., Tsagarakis, E. D., Das, R. N., Giannelis, E. P., Anastasiadis, S. H., and Anglos, D.

Subjects
*NANOPARTICLES, *ZINC oxide, *POLYETHYLENE terephthalate, *ANNEALING of metals, *PHOTOLUMINESCENCE
Abstract

A convenient and straightforward way to fabricate random lasing films based on ZnO is proposed. Highly scattering films consisting of ZnO nanoparticles are fabricated following a two-stage process that involves a) spin-coating of aqueous ZnO nanoparticle dispersions on rigid (glass) or flexible (polyethylene terephthalate) substrates and b) subsequent surface modification by means of a controlled UV laser annealing processing. Upon excitation with 150 picosecond pulses at 355 nm, the films exhibit intense photoluminescence emission, which upon crossing a threshold pump energy density, develops laser-like characteristics, namely, gain amplification, spectral narrowing and, under optimum pump conditions and sample structure, distinct lasing modes. [ABSTRACT FROM AUTHOR]

Published
2009
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2. Stochastic transition intermittency in pipe flows: Experiment and model.

Author

Zhang, Jun, Stassinopoulos, Dimitris, Alstro\m, Preben, and Levinsen, Mogens T.

Subjects
*FLUID dynamics, *TURBULENCE, *FRICTION
Abstract

New experimental results at the onset of turbulence in a gravity-driven pipe flow are presented, and a simple phenomenological model is introduced to describe the intermittent behavior observed. In this model slugs are stochastically produced at the pipe inlet, and the decrease in velocity due to turbulent friction is taken into account. The present approach shows that stochastic arguments account well for several experimental observations at low intermittency factors. In particular, it is shown that special intermittency routes to chaos are not needed to explain the exponentially decaying inverse cumulative distribution of laminar times. [ABSTRACT FROM AUTHOR]

Published
1994
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3. Space-time renormalization at the onset of spatio-temporal chaos in coupled maps.

Author

Alstrom, Preben and Stassinopoulos, Dmitris

Subjects
*COUPLED map lattices, *CHAOS theory, *SCALING laws (Statistical physics)
Abstract

Attempts to derive the universal scaling exponents characterizing the onset of spatiotemporal chaos in coupled-map lattices. Transition regime to spatiotemporal chaos via the quasiperiodic route; Utilization of space-time renormalization-group analysis; Identification of universality classes for the different types of coupling at various routes to chaos.

Published
1992
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