# gst: quadrupolar stress drives collapse of nematic order on frictional substrates.

<< The field of active nematics has traditionally employed descriptions based on dipolar activity, with interactions that align along a single axis. However, it has been theoretically predicted that interactions with a substrate, prevalent in most biological systems, would require novel forms of activity, such as quadrupolar activity, that are governed by hydrodynamic screening. >>

<< Here, by combining experiments and numerical simulations, (AA) show that upon light-induced solidification of the underlying medium, microtubule-kinesin mixtures undergo a transformation that leads to a biphasic active suspension. Using an active lyotropic model, (They) prove that the transition is governed by screening effects that alter the dominant form of active stress. Specifically, the combined effect of friction and quadrupolar activity leads to a hierarchical folding that follows the intrinsic bend instability of the active nematic layer. >>

AA << results demonstrate the dynamics of the collapse of orientational order in active nematics and present a new route for controlling active matter by modifying the activity through changing the surrounding environment. >>️

Aleksandra Ardaseva, Ignasi Velez-Ceron, et al. Beyond Dipolar Activity: Quadrupolar Stress Drives Collapse of Nematic Order on Frictional Substrates. arXiv: 2407.03723v3 [cond-mat.soft]. Jan 14, 2025. 

https://arxiv.org/abs/2407.03723

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

Keywords: gst, transition, collapse, active nematics, stress 

# gst: apropos of bubbles, the case of bubbles collapsing near a wall.

AA << study examines the pressure exerted by a cavitation bubble collapsing near a rigid wall. A laser-generated bubble in a water basin undergoes growth, collapse, second growth, and final collapse. Shock waves and liquid jets from non-spherical collapses are influenced by the stand-off ratio γ, defined as the bubble centroid distance from the wall divided by the bubble radius. (AA) detail shock mechanisms, such as tip or torus collapse, for various γ values. High-speed and Schlieren imaging visualize the microjet and shock waves. The microjet's evolution is tracked for large γ, while shock waves are captured in composite images showing multiple shock positions. Quantitative analyses of the microjet interface, shock wave velocities, and impact times are reported. Wall-mounted sensors and a needle hydrophone measure pressure and compare with high-speed observations to assess the dominant contributions to pressure changes with γ, revealing implications for cavitation erosion mechanisms. >>️

Roshan Kumar Subramanian, Zhidian Yang, et al. Bubble collapse near a wall. Part 1: An experimental study on the impact of shock waves and microjet on the wall pressure. arXiv: 2408.03479v2 [physics.flu-dyn]. Aug 8, 2024. 

https://arxiv.org/abs/2408.03479

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

Keywords: gst, bubble, bubble collapse 

# gst: collapse of a toroidal bubble inducing shock waves

<< When bubbles collapse near a wall, they typically experience an asymmetric deformation. This collapse leads to the creation of a jet that strikes the bubble interface, causing the formation of a toroidal bubble and the subsequent release of a water-hammer shock. >>️

AA << findings demonstrate that shock waves emitted from the toroidal bubble consistently propagate toward the central axis of the torus, resulting in significant pressure shocks along the axis, similar to the water-hammer shock formed during the collapse of a spherical bubble. >>️

<< In contrast, weak pressure waves are generated in the transverse directions, leading to relatively weaker pressure peaks. Furthermore, the wall-pressure peak induced by the toroidal bubble is approximately three times higher than that induced by the spherical bubble. >>️

Cheng Liu, Xiaobin Yang, et al. Investigations on the shock wave induced by collapse of a toroidal bubble. Phys. Rev. E 110, 015103. Jul 16, 2024. 

https://journals.aps.org/pre/abstract/10.1103/PhysRevE.110.015103

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

Keywords: gst, bubble, drop, waves, collapse

# gst: to find a separation between plunging and spilling wave breakers

<< While understanding breaking waves is crucial for the development of parametrizations used in ocean wave modeling for both deep and shallow water, the complete process of wave breaking is not well understood. Here (AA) present direct numerical simulations of two-dimensional solitary waves that shoal and break on a uniform beach in shallow water, with the presence of storm surge represented by an inshore region. >>️

They << classify wave breaker types and find a separation between plunging and spilling breakers when scaled by breaking amplitude and depth. (AA) compare energy dissipation during the breaking process with results from the literature without storm surge.  >>️

They << conclude that a previously developed shallow-water inertial dissipation model for wave breaking on a uniform slope can be extended to this storm surge environment with good data collapse, and further discuss possibilities for a general parametrization of wave breaking valid across different depth regimes. >>️

Hunter Boswell, Guirong Yan, Wouter Mostert. Characterizing energy dissipation of shallow-water wave breaking in a storm surge. Phys. Rev. Fluids 8, 054801. May 5, 2023. 

https://journals.aps.org/prfluids/abstract/10.1103/PhysRevFluids.8.054801

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

Keywords: gst, waves, soliton, drop 

# gst: analogy between streamers in sinking spheroids, gyrotactic plumes and chemotactic collapse (when a plume structure blows up when a parm is above a threshold)

<< In a dilute suspension where sinking spheroids or motile gyrotactic microorganisms are modelled as orientable and negatively buoyant particles, (AA) have found analytical solutions to their steady distributions for a given parallel flow profile. The coupling between their distribution and the vertical flow is nonlinear, enabling the uniform base state to bifurcate into a structure reminiscent of the streamers in settling spheroid suspension and gyrotactic plume. This bifurcation depends on a single parameter that is proportional to the average number of particles on a horizontal cross section. In a three-dimensional axisymmetric system, the plume structure blows up when the parameter is above a threshold. (AA) discuss how this singularity is analogous to the chemotactic collapse of a Keller-Segel model, and the significance this analogy entails. >>

Lloyd Fung. Analogy between streamers in sinking spheroids, gyrotactic plumes and chemotactic collapse. arXiv: 2301.07164v1 [physics.flu-dyn]. Jan 17, 2023.

https://arxiv.org/abs/2301.07164

Also

keyword 'collapse' in FonT

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

keyword 'spheroids' in FonT

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

Keywords: gst, analogy, spheroids, collapse, chemotactic collapse 

# gst: approaching the dynamics of nanobubble formation and collapse

<< While sequential optical imaging (i.e., recording movies) has contributed significantly to our understanding of cavitation and other complex bubble behavior at the larger (..) scale, the necessary length and temporal resolutions make such a traditional approach infeasible for nanobubbles, >> Garth Egan. ️

<< To take the images at the nanoscale, (AA) shot a 532-nanometer laser pulse (about 12 nanosec) to excite gold nanoparticles inside a 1.2 micron layer of water. The resulting bubbles were observed with a series of nine electron pulses (10 ns) separated by as little as 40 ns peak-to-peak. The researchers found that isolated nanobubbles were observed to collapse in less than 50 ns, while larger (∼2–3 micron) bubbles were observed to grow and collapse in less than 200 ns. >>

<< Isolated bubbles were observed to behave consistently with models derived from data from much larger bubbles. The formation and collapse were observed to be temporally asymmetric, which has implications for how results from alternate methods of experimental analysis are interpreted. More complex interactions between adjacent bubbles also were observed, which led to bubbles living longer than expected and rebounding upon collapse. >>️️

Anne M. Stark. Multiframe imaging of micron and nanoscale bubble dynamics.  Lawrence Livermore National Laboratory. Feb 09, 2022. 

https://phys.org/news/2022-02-multiframe-imaging-micron-nanoscale-dynamics.html

Garth C. Egan, Edmond Y. Lau, Eric Schwegler.  Multiframe Imaging of Micron and Nanoscale Bubble Dynamics. Nano Lett. 2022, 22, 3, 1053–1058. doi: 10.1021/ acs.nanolett.1c04101. Jan 19, 2022.

https://pubs.acs.org/doi/10.1021/acs.nanolett.1c04101

Also

keyword "bubble" in FonT

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

keyword "bolla" | "bolle" in Notes (quasistochastic-poetry): 

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

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

keywords: bubble, nano, nanobubble,  nanobubble dynamics, bubble formation, bubble collapse

# gst: apropos of turbulence, self-similarity of turbulent flows with internal and external intermittency

<< Scientists have long used supercomputers to better understand how turbulent flows behave under a variety of conditions. Researchers have now include the complex but essential concept of 'intermittency' in turbulent flows. >>️

<< Despite its seemingly random, chaotic characteristics, researchers have identified some important properties that are universal, or at least very common, for turbulence under specific conditions. (..) Much of that important turbulent motion may stem from what happens in a thin area near the edge of the flame, where its chaotic motions collide with the smoother-flowing fluids around it. This area, the turbulent-non-turbulent interface (TNTI), has big implications for understanding turbulent mixing. >>️

<< Scientists distinguish between internal intermittency, which occurs at the smallest scales and is a characteristic feature of any fully developed turbulent flow, and external intermittency, which manifests itself at the edge of the flame and depends on the structure of the TNTI. >>️

<< For Bode and Gauding (Mathis Bode, Michael Gauding), understanding the small-scale turbulence happening at the thin boundary of the flame is the point. >>

<< Our simulations are highly resolved and are interested in these thin layers, (..) For production runs, the simulation resolution is significantly higher compared to similar DNS (direct numerical simulations ) to accurately resolve the strong bursts that are connected to intermittency. >> Mathis Bode. 

️

Simulations of turbulence's smallest structures. Gauss Centre for Supercomputing. Jul 8, 2021. 

https://www.sciencedaily.com/releases/2021/07/210708103609.htm

<< In turbulent jet flows, the phenomenon of external intermittency originates from a sharp layer, known as the turbulent/ non-turbulent interface, that separates the turbulent core from the surrounding irrotational fluid. First, it is shown that low-order and higher-order structure functions in both the core and the shear layer of the jet satisfy complete self-preservation, which means that structure functions are invariant with time and collapse over the entire range of scales, regardless of the set of length and velocity scales used for normalization. Next, the impact of external intermittency on small-scale turbulence is studied along the cross-wise direction by the self-similarity of structure functions. It is shown that structure functions exhibit from the centre toward the edge of the flow a growing departure from self-similarity and the prediction of classical scaling theories. By analysing statistics conditioned on the turbulent portion of the jet, it is demonstrated that this departure is primarily due to external intermittency and the associated similarity-breaking effect. >>️

Michael Gauding, Mathis Bode, et al. Self-similarity of turbulent jet flows with internal and external intermittency. Journal of Fluid Mechanics.  919 , 25, A41. doi: 10.1017/ jfm.2021.399. Jun 1,  2021.

https://www.cambridge.org/core/journals/journal-of-fluid-mechanics/article/abs/selfsimilarity-of-turbulent-jet-flows-with-internal-and-external-intermittency/170B9415870F47A94D041FEE7E904840

Michael Gauding, Mathis Bode, et al. On the combined effect of internal and external intermittency in turbulent non-premixed jet flames. Proceedings of the Combustion Institute. 38, (2): 2767-2774. doi: 10.1016/ j.proci.2020.08.022. Dec 9, 2020.

https://www.sciencedirect.com/science/article/abs/pii/S1540748920306064

keyword 'Intermittency' in ScienceDirect

https://www.sciencedirect.com/topics/engineering/intermittency

Also

1939 - stocastici accessi (di traslitteranti ludi). Notes. Jan 11, 2006. 

(quasi-stochastic poetry )

https://inkpi.blogspot.com/2006/01/1939-stocastici-accessi-di.html

2064 - on responses to deviant stimuli.

Notes. Sep 26, 2006. (quasi-stochastic poetry )

https://inkpi.blogspot.com/2006/09/2064-on-responses-to-deviant-stimuli.html

# gst: apropos of (multitudes) of transitional droplets, when a liquid film collapses in a foam ...

<< Foams have unique properties that distinguish them from ordinary liquids and gases, and are ubiquitously observed in nature, both in biological systems and industrial products. >>

️

<< Once a crack appears near the border and a collapse front is formed, (AA) find that the curvature of the front reverses as it migrates, followed by the emergence and emission of droplets. (they) elucidate the origins of this behavior and discuss the stability of foams, establishing how the characteristic time scales of the process relate to each other. >>️

Naoya Yanagisawa, Marie Tani, Rei Kurita. Dynamics and mechanism of liquid film collapse in a foam. Soft Matter. 17, 1738-1745. Feb 17, 2021.

https://pubs.rsc.org/en/content/articlelanding/2021/SM/D0SM02153A#

Also

keyword 'foam' in FonT

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

keyword 'collapse' in FonT

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

keyword 'schiuma' in Notes

(quasi-stochastic poetry)

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

# gst: apropos of transitions, tsunami waves generated by granular collapses.

<< Tsunami waves induced by landslides are a threat to human activities and safety along coastal areas. In this paper, (AA) characterize experimentally the waves generated by the gravity-driven collapse of a dry granular column into water. Three nonlinear wave regimes are identified depending on the Froude number Fr_f based on the ratio of the velocity of the advancing granular front and the velocity of linear gravity waves in shallow water: transient bores for large Fr_f, solitary waves for intermediate values of Fr_f, and nonlinear transition waves at small Fr_f. >>️

Wladimir Sarlin, Cyprien Morize, et al. Nonlinear regimes of tsunami waves generated by a granular collapse.    

Journal of Fluid Mechanics, 919, R6. doi:10.1017/ jfm.2021.400. May 28, 2021. 

https://www.cambridge.org/core/journals/journal-of-fluid-mechanics/article/abs/nonlinear-regimes-of-tsunami-waves-generated-by-a-granular-collapse/3F38B26548B891FA9AE8A4018FF992A4#

James Badham. The Science of tsunamis. University of California. Santa Barbara. Jun 21, 2021. 

https://www.sciencedaily.com/releases/2021/06/210621160524.htm

Froude number (Fr_f)

https://en.m.wikipedia.org/wiki/Froude_number

Also

keyword 'grain' in FonT

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

keyword 'grani' in Notes (quasi-stochastic poetry)

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

keyword 'waves' in FonT

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

keyword 'onda' in Notes (quasi-stochastic poetry)

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

# gst: the dynamics of a collective bubble (in a foam) that collapse in a droplet

<< Foams have unique properties that distinguish them from ordinary liquids and gases, and are ubiquitously observed in nature, both in biological systems and industrial products. (..) understanding how bubbles in a foam collapse is an important aspect for product longevity and tailoring physical properties. >>

<< Once a crack appears near the border and a collapse front is formed, (AA) find that the curvature of the front reverses as it migrates, followed by the emergence and emission of droplets. >>

<<  It is particularly interesting to note how the shape of the front changes as it migrates. >>

Naoya Yanagisawa, Marie Tani, Rei Kurita. Dynamics and mechanism of liquid film collapse in a foam. Soft Matter 17, 1738-45. doi: 10.1039/ D0SM02153A. Feb 17, 2021.

https://pubs.rsc.org/en/content/articlelanding/2021/SM/D0SM02153A#!divAbstract   

<< An initial crack in a film creates a RVPB (released vertical plateau border). A second crack event in the film causes a "collapse front" to be formed which sweeps up the RVPB before its shape begins to flatten and invert, finally leaving a droplet. >>

When foams collapse (and when they don't). Tokyo Metropolitan University. Mar 01, 2021. 

https://phys.org/news/2021-03-foams-collapse-dont.html   

Also

keyword 'drop' or 'droplet' in FonT

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

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

# gst: the role of surface tension during the collapse of a viscous bubble

<< The rupture and collapse of viscous bubbles are widespread in nature and in industrial applications. The phenomenon is accompanied by elastic sheets that develop radial wrinkles. While the weight of the film appeared to play a dominant role during film collapse and wrinkling instability, in this work, gravity appeared to play a surprisingly negligible role. Based on fluid mechanics of the phenomena, Oratis et al. showed surface tension to be the driving factor during collapse to initiate dynamic buckling instability and wrinkling behavior, accompanied with the breakdown of curved viscous and viscoelastic films. >>

Thamarasee Jeewandara. Ripple effects after slow-motion bubble collapse. Aug 17, 2020.

https://phys.org/news/2020-08-ripple-effects-slow-motion-collapse.html   

Alexandros T. Oratis, John W. M. Bush, et al. A new wrinkle on liquid sheets: Turning the mechanism of viscous bubble collapse upside down. Science. Vol. 369, Issue 6504, pp. 685-688. doi: 10.1126/ science.aba0593. Aug 7, 2020

https://science.sciencemag.org/content/369/6504/685

# chem: bizarre phase transitions in tantalum disulfide, it should be a conducting metal, but in the real world, it acts like an insulator

<< It has long been known that  crystalline materials should be good conductors when they have an odd number of electrons in each repeating cell of the structure, but may be poor conductors when the number is even. However, sometimes this formula does not work, with one case being "Mottness," a property based on the work of Sir Nevill Mott. According to that theory, when there is strong repulsion between electrons in the structure, it leads the electrons to become "localized"-paralyzed, in other words-and unable to move around freely to create an electric current. >>

<< For the current study, (..) the research group decided to look at tantalum disulfide, a material with 13 electrons in each repeating structure, which should therefore make it a conductor. However, it is not, and there has been controversy over whether this property is caused by its "Mottness" or by a pairing structure. >>

<< The exact nature of the insulating state and of the phase transitions in tantalum disulfide have been long-standing mysteries, and it was very exciting to find that Mottness is a key player, aside from the pairing of the layers. This is because theorists suspect that a Mott state could set the stage for an interesting phase of matter known as a quantum spin liquid. >> Christopher Butler. 

Jens Wilkinson. 'Tantalizing' clues about why a mysterious material switches from conductor to insulator. 

 RIKEN. May 18, 2020.

https://phys.org/news/2020-05-tantalizing-clues-mysterious-material-conductor.html   

AA << also observe the collapse of Mottness at an extrinsically re-stacked termination, demonstrating that the microscopic mechanism of insulator-metal transitions lies in degrees of freedom of inter-layer stacking. >>

C. J. Butler, M. Yoshida, et al. Mottness versus unit-cell doubling as the driver of the insulating state in 1T-TaS2. Nat Commun 11, 2477. doi: 10.1038/ s41467-020-16132-9. May 18, 2020

https://www.nature.com/articles/s41467-020-16132-9   

Also

Quantum spin liquid. 

https://en.m.wikipedia.org/wiki/Quantum_spin_liquid

# life: to save Western lifestyle from a catapulting collapse (caused by one or two Wuhan "achoo") use a techno mask (e.g. "cowboy" or "burqa" techno masks)

<< WHEN YOU LOOK at photos of Americans during the 1918 influenza pandemic, one feature stands out above all else: masks.  (..)  Newspapers published instructions for sewing masks at home. >>

<< After the 1918 pandemic, the prophylactic use of masks among the general public largely fell out of favor in America and much of the West. The US Centers for Disease Control and Prevention has almost never advised healthy people to wear masks in public to prevent influenza or other respiratory diseases. In the past few months, with medical supplies dangerously diminished, the CDC, US surgeon general Jerome Adams, and the World Health Organization have urged people not to buy masks, paradoxically claiming that masks are both essential for the safety of health care workers and incapable of protecting the public from Covid-19. >>

<< Recently, some experts have disputed this contradictory advice. They propose that widespread use of masks is one of the many reasons why China, Japan, South Korea, and Taiwan have controlled outbreaks of coronavirus much more effectively than the US and Europe. "Of course masks work," sociologist Zeynep Tufekci wrote in a New York Times editorial. "Their use has always been advised as part of the standard response to being around infected people." Public health expert Shan Soe-Lin and epidemiologist Robert Hecht made a similar argument in the Boston Globe (..) Last week, George Gao, director-general of the Chinese Center for Disease Control and Prevention, said that America and Europe are making a "big mistake" by not telling the public to wear masks during the ongoing pandemic. >>

<< N95s (N95 mask) are so-named because they filter out 95 percent of particles with a diameter of 0.3 microns, (..) Particles 0.3 microns wide are just the right size to ride a stream of air through a filter’s fibrous maze, but it is still possible to thwart them with enough twists and turns.>>

<< the bacterium that causes anthrax is 0.8 microns wide and 1.4 microns long, whereas influenza viruses and coronaviruses are usually between 0.08 and 0.12 microns. But microbes expelled from someone’s respiratory tract are rarely naked: the droplets they travel in range in size from 0.6 to more than 1,000 microns. >>

<< Although surgical masks are not tightly sealed like N95s, the filters they contain are still a major impediment to microbes. The CDC and other health agencies often say that surgical masks catch only spurts of bodily fluids and very large respiratory droplets, and that they cannot filter tiny infectious particles. But this is simply not true. >>

<< Because so many trials find only a marginal benefit or none at all, some health agencies have decided against recommending masks to the general public. But the inconsistency of randomized trials does not negate the robust physical evidence that masks block respiratory droplets and microbes.  >>

<< "To be honest, it’s common sense," says Tang (virologist Julian Tang). "If you put something in front of your face, it’s going to help more than not." If enough people wear masks at least somewhat correctly at least some of the time, the overall benefits could be dramatic. A 2011 review of high-quality studies found that among all physical interventions used against respiratory viruses-including handwashing, gloves, and social distancing-masks performed best, although a combination of strategies was still optimal. >>

It's Time to Face Facts, America: Masks Work. Official advice has been confusing, but the science isn't hard to grok. Everyone should cover up. Wired. Ideas. March 30, 2020.

https://www.wired.com/story/its-time-to-face-facts-america-masks-work/

Also 

a funky, immediate approach of the sneezing from Wuhan (a relative safe barrier - this device is NOT a filter) FonT.  Mar 20, 2020

https://flashontrack.blogspot.com/2020/03/life-funky-immediate-approach-of.html

Also

climate change plus Zika, then a behavioral transition, hat burqa- like everywhere ... FonT.  Mar13, 2016.

https://flashontrack.blogspot.com/2016/03/s-epidemiol-climate-change-plus-zika.html

Also

keyword 'virus' in FonT

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

keyword 'virus' in Notes (quasi- stochastic poetry)

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

keyword 'snake' in FonT

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

keyword 'bat' in FonT

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

# life: a funky, immediate approach of the sneezing from Wuhan (a relative safe barrier - this device is NOT a filter)

if (of course, if and only if) the problem is to save Western civilization from autocatalytic noise (and subsequent psychic, behavioral, political, economical, cultural catapulting collapse) caused by 1,2 sneezing of Wuhan, here a funky, immediate approach;

you have to get it: 

(1) thiny film (e.g. one piece of a thin film roll, made by polyethylene, used to wrap food);

(2) pocket cotton handkerchief  (like the ones used by cowboys, like those popping out of the pocket of the jackets that italian Prime Minister wears, perhaps wider);

(3) scotch tape (transparent adhesive tape);

below the assembly (1-3 minutes to compose it, two or 'n' times a day); 

This device is relatively safe even if your interlocutor spits in your mouth (in that  case, to protect the eyes you remember that you also need protective glasses and any earplugs, disposable gloves ...);

you can get more security by spraying - on the outside of the handkerchief - a mixture of alcohol, hydrogen peroxide (H2O2) and distilled water (the composition indicated by the WHO,  without glycerol);  cfr Guide to Local Production:  WHO-recommended Handrub Formulations  (reagents for formulation 1) Revised April 2010  

https://www.who.int/infection-prevention/tools/hand-hygiene/handrub-formulations/en

doc.pdf

https://www.who.int/gpsc/5may/Guide_to_Local_Production.pdf

With this device you can travel around the city, on buses, on trains, ... in relative safety, yours and your neighbors; 

instead of film roll for food you could use a waterproofing spray but the cost is high and the chemical one is probably toxic for human

Also

keyword 'virus' in FonT

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

keyword 'virus' in Notes (quasi- stochastic poetry)

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

keyword 'snake' in FonT

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

keyword 'bat' in FonT

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

# life: the fate of humans and insects intertwine

<< The fate of humans and insects intertwine, especially through the medium of plants. >>

Michael J.Samways, Philip S.Barton, et al. Solutions for humanity on how to conserve insects. Biological Conservation. Volume 242, 108427,  Review. Feb 9, 2020.

https://www.sciencedirect.com/science/article/pii/S0006320719317793

Damian Carrington. Fates of humans and insects intertwined, warn scientists. Experts call for solutions to be enforced immediately to halt global population collapses. Feb 20, 2020.

https://www.theguardian.com/environment/2020/feb/20/fates-humans-insects-intertwined-scientists-population-collapse

Also

the beetle Carabaeus lamarcki, dancer and sky analyzer.  May 14, 2016.

https://flashontrack.blogspot.com/2016/05/s-behav-beetle-carabaeus-lamarcki.html

# gst: a cylindrical solitonlike that collapses into a spherical shape, and, along the filaments, central cores of matter exhibit fuzzies

In AA simulation, << the dark matter filaments show coherent interference patterns on the boson de Broglie scale and develop cylindrical solitonlike cores, which are unstable under gravity and collapse into kiloparsec-scale spherical solitons. Features of the dark matter distribution are largely unaffected by the baryonic feedback. On the contrary, the distributions of gas and stars, which do form along the entire filament, exhibit central cores imprinted by dark matter-a smoking gun signature of FDM ("fuzzy" dark matter). >>

Philip Mocz, Anastasia Fialkov, et al. First Star-Forming Structures in Fuzzy Cosmic Filaments. Phys. Rev. Lett. 123, 141301. Oct 2, 2019.     https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.123.141301  

Jennifer Chu. This is how a 'fuzzy' universe may have looked. Massachusetts Institute of Technology. Oct 3, 2019       https://m.phys.org/news/2019-10-fuzzy-dark-disrupts-conventional.html   

FonT

intrigante qui come una simulazione di evoluzione cosmologica - filamenti strutturati a cilindro mutanti (collassanti) in strutture sferoidali (ma non a generica fluttuante frittella) formanti, nei filamenti di gas,  serie (sciami?) di kernel a dinamiche fuzzy - possa far immaginare generici contesti altri ...

# geo gst: even small flank failures can cause large tsunamis

<< Volcanogenic tsunamis are one of the deadliest volcanic phenomena. >>

<< Small flank failures causing large tsunamis represent a vastly underappreciated geohazards-current tsunami monitoring systems do not monitor for this kind of volcanic activity, instead focusing on large earthquakes or proxies related to unusual increases in magma intrusion.  >>

<< This collapse was captured in unprecedented detail by satellite remote sensing, providing an opportunity to understand the collapse of the volcano (Anak Krakatau volcano,  Indonesia) in a way that has not previously been possible at any volcanic island in the world. >>

Reconstructing the Anak Krakatau flank collapse that caused the December 2018 Indonesian tsunami. Geological Society of America. Aug 30, 2019.   https://m.phys.org/news/2019-08-reconstructing-anak-krakatau-flank-collapse.html   

<< the volume of material initially lost from the volcano flank failure (..) was relatively small (~0.1 km3) compared to the overall changes observed during the entire eruption, but it was nonetheless able to generate rapid tsunami waves with devastating impacts. The flank failure also changed the eruption style and the upper volcanic plumbing system, with the subsequent explosive eruptions destroying the summit and then partially rebuilding the lost flank.  >>

Rebecca Williams, Pete Rowley, Matthew C. Garthwaite. Reconstructing the Anak Krakatau flank collapse that caused the December 2018 Indonesian tsunami. Geology. doi.org/10.1130/G46517.1. Aug 30, 2019.    https://pubs.geoscienceworld.org/gsa/geology/article-abstract/573356/reconstructing-the-anak-krakatau-flank-collapse

# gst: apropos of bubbles, how simple foams collapse

<< When a bubble breaks, (AA) found that a collapse event propagates via impact with the receding film and tiny scattered droplets breaking other bubbles. >>

<< A key finding was that changing the viscosity of the fluid did not lead to a significant change in the number of bubbles broken. Methods to stabilize foams commonly rely on changing the viscosity, yet the team's findings clearly show how both the number of bubbles collapsed and the velocity of the receding film are unaffected. >>

Two distinct physical mechanisms identified for how simple foams collapse. Tokyo Metropolitan University. June 10, 2019.

https://m.phys.org/news/2019-06-distinct-physical-mechanisms-simple-foams.html

Naoya Yanagisawa, Rei Kurita. In-situ observation of collective bubble collapse dynamics in a quasi-two-dimensional foam. Scientific Reports 9, Article number: 5152. March 26, 2019

https://www.nature.com/articles/s41598-019-41486-6

# gst: how a bubble pops

<< After a bubble bursts at a liquid surface, the collapse of the cavity generates capillary waves, which focus on the axis of symmetry to produce a jet. >>

AA << show that the time-dependent profiles of cavity collapse (..) and jet formation (..) both obey a  inviscid scaling, which results from a balance between surface tension and inertia forces. >>

Ching-Yao Lai, Jens Eggers, and Luc Deike. Bubble Bursting: Universal Cavity and Jet Profiles. Phys. Rev. Lett. 121, 144501. Oct 2, 2018

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.121.144501  

John Sullivan. Math describes how bubbles pop. Princeton University. Oct 31, 2018.

https://m.phys.org/news/2018-10-math.html

# gst: when a 'ricequake' repeat perpetually and propagate

<< puffed rice and milk can serve as a stand-in to simulate collapsing ice shelves and rockfill dams. >>

<< Intrigued by their findings, the researchers created what they call a "crushing wave model," which they believe could prove useful for describing the behavior of much larger collapse events. >>

Bob Yirka. Using puffed rice to simulate collapsing ice shelves and rockfill dams. Oct 15, 2018.

https://m.phys.org/news/2018-10-puffed-rice-simulate-collapsing-ice.html

<< These "ricequakes" repeat perpetually during the experiments and propagate upward through the material. >>

Itai Einav, Francois Guillard. Tracking time with ricequakes in partially soaked brittle porous media. Science Advances  Oct 12, 2018. Vol. 4, no. 10, eaat6961. doi: 10.1126/sciadv.aat6961.

http://advances.sciencemag.org/content/4/10/eaat6961