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mercoledì 27 gennaio 2021
# gst: apropos of 'strange' transitions to self-assemble into an egg; the coordinated elastic behavior to swirl in a vortex (D. melanogaster)
giovedì 23 novembre 2023
# gst: kirigami exposed to external flows.
sabato 29 aprile 2023
# gst: pattern generation through turbulent cascades
mercoledì 5 luglio 2023
# brain: spiral waves at the edge of neural tissue during cognitive processing.
sabato 5 agosto 2023
# gst: tipping in a low-dimensional model of a (tropical) cyclone.
sabato 30 luglio 2016
# s-gst: vortex knots in wave systems
<< Waves surround us all the time: sound waves in the noise around us, light waves enabling us to see, and according to quantum mechanics, all matter has a wave nature. Most of these waves, however, do not resemble the regular train of waves at the shore of the ocean—the pattern is much more chaotic. Most significantly, the whirls and eddies form lines in space called vortices. Along these lines, the wave intensity is zero, and natural wave fields - light, sound and quantum matter - are filled with a dense tangle of these null filaments >>
Knots in chaotic waves. July 29, 2016.
http://m.phys.org/news/2016-07-chaotic.html
Alexander J. Taylor & Mark R. Dennis. Vortex knots in tangled quantum eigenfunctions. Nature Communications. Published 29 Jul 2016 DOI: 10.1038/ncomms12346 OPEN
http://www.nature.com/ncomms/2016/160729/ncomms12346/full/ncomms12346.html
lunedì 8 luglio 2019
# phys: optical vortex to probe magnetism in matter
<< A light "corkscrew" is sensitive to the local magnetic field direction, so it can be used to probe magnetism in a material. >>
<< Circularly polarized light can act as a powerful probe of magnetism in matter. By measuring differences in the transmission of light beams polarized in different directions as they pass through a material, physicists can unravel atomic-level details of the material’s magnetic properties. >>
Synopsis: Optical Vortices Can Probe Magnetism. Jun 12, 2019.
https://physics.aps.org/synopsis-for/10.1103/PhysRevLett.122.237401
A. A. Sirenko, P. Marsik, et al. Terahertz Vortex Beam as a Spectroscopic Probe of Magnetic Excitations. Phys. Rev. Lett. 122, 237401. Jun 12, 2019.
https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.122.237401
giovedì 22 settembre 2022
# life: apropos of quasi-stochastic (bizarre) landscapes in high-dimension, a case of double RAG-time inside a black hole with vortices
venerdì 19 novembre 2021
# gst: apropos of oscillations, viscous streaming around an immersed microfeature (e.g. a bubble)
martedì 3 maggio 2016
# s-gst: measuring energy levels inside transitional dis-order(s)
<< Vortex filaments in classical and quantum fluids and DNA macromolecules, magnetic flux tubes, phase defects, polymers may interact and recombine through reconnection of neighboring strands. Details of the process depend on specific local mechanisms that may differ from case to case, but certain qualitative features — such as the preservation of the original strand orientation after recombination — are generic and common to all systems. >>
<< The study of these processes is clearly of great importance, because the change of topology is often accompanied by a change in energy, entropy and function. >>
<< (..) HOMFLYPT polynomial recently introduced for fluid knots (..) provides a powerful tool to measure topological complexity of various physical systems. >>
Liu, X., Ricca, R. L. Knots cascade detected by a monotonically decreasing sequence of values. Sci. Rep.6, 24118; doi: 10.1038/srep24118 (2016).
http://www.nature.com/articles/srep24118
Quanta energia è nascosta nel caos? Bicocca, Milano, 2 maggio 2016
http://www.unimib.it/open/news/Quanta-energia-e-nascosta-nel-caos-Ce-lo-dice-il-polinomio-targato-Bicocca-Beijing-UTech/4936093294137195314
sabato 13 luglio 2019
# gst: a floating vortex of fluff, the flight of the dandelion
<< A fluff-topped dandelion seed can float through the air for more than a kilometer before it drifts to the ground. In experiments last year, researchers revealed that the white filaments in the fluff-known collectively as a pappus-create a ring-shaped wake behind the seed that is associated with low pressure and acts to keep it aloft. >>
AA << have theoretically modeled the airflow around the pappus, reproducing the experimentally measured wake and showing that it provides the seed with steady flight capabilities. >>
Katherine Wright. Dandelion Fluff Perfected for Flight. July 2, 2019
https://physics.aps.org/synopsis-for/10.1103/PhysRevFluids.4.071901
Ledda PG, Siconolfi L, et al. Flow dynamics of a dandelion pappus: A linear stability approach. Phys. Rev. Fluids 4, 071901(R) July 2, 2019.
https://journals.aps.org/prfluids/abstract/10.1103/PhysRevFluids.4.071901