# gst: floating droplets excited with Faraday waves

<< The Faraday instability has been extensively studied in bounded containers but only recently has research on this phenomenon in flexible domains been conducted. (AA) study floating liquid droplets with Faraday waves excited on their surface, which undergo a slow time evolution toward a stable noncircular shape. (AA) develop a theoretical model for the evolution of the boundary of the droplet, thus allowing to simulate its full transient motion toward steady state. >>

<< By changing the forcing frequency and amplitude of (the) system, (They) observe a variety of stable droplet shapes. (..) Interesting transient behavior such as hysteresis is also discussed, where the final droplet shape depends on its previous shape. Finally, (They) touch upon droplets that do not reach a steady state shape, instead oscillating periodically in time or rotating at a constant angular velocity. >>️

L. Mazereeuw. Theoretical and experimental investigation of the shapes formed by floating droplets excited with Faraday waves. Phys. Rev. Fluids 9, 124404. Dec 19, 2024.

https://journals.aps.org/prfluids/abstract/10.1103/PhysRevFluids.9.124404

Also: drop, waves, instability, transition, in https://www.inkgmr.net/kwrds.html 

Keywords: drops, droplets, droploids, waves, instability, Faraday instability, transitions   

# gst: rearrangements of a jammed 2-D emulsion (during slow compression).

<< As amorphous materials get jammed, both geometric and dynamic heterogeneity are observed. (AA)  investigate the correlation between the local geometric heterogeneity and local rearrangements in a slowly compressed bidisperse quasi-two-dimensional emulsion system. The compression is driven by evaporation of the continuous phase. >>

<< droplets in heterogeneous local regions are more likely to have local rearrangements. These rearrangements are generally T1 events where two droplets converge toward a void, and two droplets move away from the void to make room for the converging droplets. Thus, the presence of the voids tends to orient the T1 events. >>️

<< The presence of a correlation between the structural quantities and the rearrangement dynamics remains qualitatively unchanged over the entire range of packing fractions observed. >>️

Xin Du, Eric R. Weeks. Rearrangements during slow compression of a jammed  two-dimensional emulsion. Phys. Rev. E 109, 034605. Mar 20,  2024.

https://journals.aps.org/pre/abstract/10.1103/PhysRevE.109.034605

Also: drop, in https://www.inkgmr.net/kwrds.html 

Keywords: drops, droplets, droploids 

# gst: when a soliton juggles ('catches' and 'throws') droplets

<< Jugglers normally work with solid objects, but a research team has now demonstrated a system that juggles liquid drops. (AA)  have previously shown that liquid drops can bounce in place above the surface of the same liquid—or bounce while moving across the surface—if the container is continuously vibrated (..) In these past experiments, the surface was nearly flat, except for waves generated by the bouncing drop. In the new work by undergraduate student Camila Sandivari of the University of Chile and her colleagues, the vibrations cause the liquid surface to form a large standing wave that actively “catches” and “throws” the drop during each cycle of its oscillation. The trapping of the drop is similar in principle to other types of wave traps, such as laser-based optical tweezers, and the system could potentially lead to new types of traps for larger objects. >>

AA << placed water mixed with a dye and a surface-tension-reducing agent in a 20-cm-long, 2.6-cm-wide basin that supports an unusual type of surface wave when the basin is vibrated in a specific frequency range. In this wave, rather than a series of oscillating peaks and valleys, there is only a single standing wave peak, called a soliton. However, this peak doesn’t oscillate uniformly across the basin’s short dimension (the width). A peak appears at one of the long walls coincident with a valley at the opposite wall, and then the peak and the valley switch places moments later, keeping a relatively flat “node” line along the central long axis of the basin. >>

AA << used a pipette to place a few-millimeter-wide drop of the same fluid just above the oscillating soliton, close to one of the long walls, and found that drops could be juggled for up to 90 minutes. The team attributes this unusual stability in part to a property of the soliton: if the drop wanders off-center, the oscillating surface wave pulls it back toward its center, similar to the way the laser field in optical tweezers is able to stably hold a small particle at its center. >>

David Ehrenstein. Juggling Water Drops. Physics 16, 21. Feb 10, 2023. 

https://physics.aps.org/articles/v16/21

Also

keyword 'drop' | 'droplet' | 'droploids' in FonT

https://flashontrack.blogspot.com/search?q=drop

https://flashontrack.blogspot.com/search?q=droplet

https://flashontrack.blogspot.com/search?q=droploids

keyword 'goccia' in Notes 

(quasi-stochastic poetry)

https://inkpi.blogspot.com/search?q=goccia

keyword 'solitons' in FonT

https://flashontrack.blogspot.com/search?q=soliton

https://flashontrack.blogspot.com/search?q=solitons

Keywords: gst, solitons, drop, droplet, droploids, goccia

# life: a proposito di transizioni ...

a proposito di transizioni ... 

<< se si considera la limitatezza del numero degli standards da essi tante volte 'rigenerati'. >> 

<< Il problema qui - in una prospettiva sperimentale - non sembra la generazione (quasistocastica?) delle forme inattese, bensi' inerente la struttura logico- funzionale dei "filtri", dei setacci cioe', capaci di trattenere (e conservare) le soluzioni funzionali al codice, "metastabili" in senso evolutivo, con l'eliminazione di tutto cio' che puo' contribuire alla rigidita' strutturale dell' insieme.  >>

2134 - bizzarrie bop sugli standard. Notes. Apr 29, 2007. 

https://inkpi.blogspot.com/2007/04/2134-bizzarrie-bop-sugli-standard.html

https://twitter.com/flashontrack/status/1547867345502158853

Also

keyword 'transition' | 'transitional' in FonT

https://flashontrack.blogspot.com/search?q=transition

https://flashontrack.blogspot.com/search?q=transitional

keyword 'transition' | 'transizion*' in Notes (quasi-stochastic poetry)

https://inkpi.blogspot.com/search?q=transition

https://inkpi.blogspot.com/search?q=transizione

https://inkpi.blogspot.com/search?q=transizioni

Keywords: life, transition, evolution, quasi-stochastic,  poetry, quasi-stochastic poetry,  fuzzypoe, droploids.