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giovedì 17 febbraio 2022

# 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. 


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.


Also

keyword "bubble" in FonT


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



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




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martedì 15 febbraio 2022

# gst: transitional dynamics among gyrotactic (prolate spheroid) swimmers in turbulence


<< In this study, (AA) consider small, elongated, gyrotactic, swimming particles in homogenous isotropic turbulence (..). Many motile phytoplankton species are gyrotactic, i.e., their swimming direction results from the competition between shear-induced viscous torque and the stabilizing torque due to bottom-heaviness. (..)  Moreover, both single phytoplankton cells and multicellular phytoplankton chains can have elongated shapes, which makes the study of gyrotactic active particles with prolate shapes necessary. >>

AA addressed the following problems:
<< (i) How the clustering is affected by the swimming number Φ and the stability number Ψ? In particular, how to characterize the extent of clustering based on the three-dimensional Voronoi analysis?
(ii) How the clustering is related to the flow structures? This question has two perspectives.  From the space perspective, what are the regions that particles accumulate in? From the time perspective, how long do particles exist in an aggregated state? >>

Zehua Liu, Linfeng Jiang, Chao Sun. Accumulation and alignment of elongated gyrotactic swimmers in turbulence. arXiv:2202.04351v1 [physics.flu-dyn]. Feb 9, 2022.


Also

The effect of noise on the dynamics of microswimmers in externally-driven fluid flows.  


keywords 'turbulence' in FonT   


keywords 'turbolento' in Notes (quasi-stochastic poetry)


keywords: transition, swimmers,  gyrotactic swimmers, spheroids,  prolate spheroids, stability, turbulence


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giovedì 10 febbraio 2022

# gst: liquid–liquid phase transition, the two forms of liquid water (mixed with the natural antifreeze trehalose)


<< Liquids are structurally disordered, so it’s not immediately obvious how they can support two distinct structures with different densities. But that does seem to be possible for liquids in which some degree of directional bonding, such as hydrogen bonds between adjacent water molecules, makes distinct local structures possible. Liquid–liquid transitions have been reported, for example, in silicon, gallium, phosphorus and silicates. But finding one in supercooled water has proved very challenging. There have been previous claimed observations of a liquid–liquid transition in aqueous solutions at ambient pressure, (..) where the solute, such as the sugar glycerol, sometimes used as a cryoprotectant, lowers the freezing point. But such claims have been disputed.(..) Other researchers have reported liquid-like behaviour as the two well-established high- and low-density forms of amorphous (glass-like) ice interconvert. (..) >>

<< In 2014 Yoshiharu Suzuki (..) working with veteran water researcher Osamu Mishima, reported possible signs of a liquid–liquid transition, ending in a critical point where the two liquid states become indistinguishable, in emulsified, supercooled solutions of glycerol. (..) They saw signs of two distinct disordered states with different densities at a temperature of 150K. But there was no direct evidence that both were liquids, rather than amorphous ice. >>

<< Suzuki has now explored the same approach using trehalose as the solute – a sugar produced as a natural cryoprotectant by some organisms, such as insects, that experience extreme cold, to prevent their blood from freezing. He pressurised dilute emulsified solutions to about 0.6GPa at a range of temperatures below 159K, and then decompressed them again.  >>

<< Such hysteresis – whereby the density jumps at different pressures on compression and decompression – is normal for a first-order transition where a parameter such as density changes discontinuously. It reflects the fact that the transition has to start with the chance formation of a ‘nucleus’ of the new phase, which then grows. >>

<< Suzuki is not yet sure why trehalose stabilises water so well against crystallisation, compared with glycerol – but this might help explain why life uses it as an antifreeze. >>

Philip Ball. Direct evidence emerges for the existence of two forms of liquid water. Feb 1, 2022.


Also

keyword 'water' in FonT


keyword 'transition' | 'transitional' in FonT



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




keywords: gst, transition, liquid-liquid transition, water



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lunedì 7 febbraio 2022

# life; Hollywood (movies) revisited, you must be aware of the fact that Alien Entities will share our planet with us and, marginally, ...


Hollywood (movies) revisited, you must be aware of the fact that Alien Entities will share our planet with us and, marginally, will modify our neurobiology with physiological 'magic strings' virus-injected (*) to 'gently' subdue us.  Are you ready for all this, anzicheforse?

(*) virus-injected approach, motivated by the fact that Terrestrials use NOT to attack retroviruses with 'pastroky' vaccines ...

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<< David (Leonard David) said that extraterrestrials, however, could be aware of us and be deliberately ignoring our planet, which would represent an equally devastating blow to the human sense of self-importance. >>
️
<< We could be the dolts of the universe. >> Leonard David. 
️
 UFOs ‘Something’s coming’: is America finally ready to take UFOs seriously? Adam Gabbatt in New York
@adamgabbatt Sat 5 Feb 2022 08.00 GMT 


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keyword 'oops' in FonT


keyword 'magic string' in FonT


Also

Dr. J. Allen Hynek (Astronomer, the scientific consultant of the U.S. Air Force Project Sign (1948), Project Grudge (1949), Blue Book (1952–1969).


PS:  io non sono mai stato testimone di alieni o di manifestazioni di entità aliene. Tuttavia, forse (qui sottolineo forse), potrei averne frequentata una per decenni. Mia madre era per me una incognita; beveva l'essenziale, non fumava, non dormiva, mangiava poco, non si ammalava, era sempre in energico movimento. Passati i novanta anni di età - grondante di sudore, dopo avere trascorso, giusto per passare il tempo, un paio di ore a stirare nel mezzogiorno della calura agostana riminese - qualche volta l'ho sentita pronunciare la frase: "andrò a coricarmi perchè mi sento un po' stanca". Quando lei entrava in una stanza io immaginavo che virus e batteri sarebbero fuggiti terrorizzati per cercare di evitare quello che di lì a poco sarebbe potuto succedere. Lei era impermeabile a qualsivoglia ideologia o argomentazione che non si traducesse in immediata modalità operativa. Quale (apparente) paradosso, per lei era anche normale individuare e ribaltare immediatamente i punti chiave in merito a qualsiasi argomento. Anche se non lo dava a vedere, era una persona sostanzialmente avversa a qualsivoglia autorità imposta. Ricordo bene che le uniche tesi che non aggrediva erano quelle che trattavano la musica blues, il jazz, il rock - forse perchè intuiva che tali approcci fossero per sè stessi fondamentalmente auto-ribaltanti - e la chimica che, anche quando poteva contenere aspetti meramente speculativi, fantasmatici, lei avrebbe potuto comunque scorgere qualche indispensabile componente operativa osservazionale- sperimentale. 

Per questa sua unicità, dall'età di dieci anni fino ai quindici, ho avuto il sospetto che lei potesse essere il prodotto di qualche ignoto esperimento alieno. 

A distanza di decenni penso che mia madre, sebbene da bambina le avessero imposto di conseguire la sola istruzione elementare - come peraltro molte della sua generazione, sarebbe stata (terrestre o aliena) un valido 'naturale' co-addestratore nel team di una scuola Shaolin.

keywords: UFO, UFOs, UAP, EBE ,
AATIP, UAPTF ,OVNI , virus,  magic string, aliens, esobio, exobiology



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sabato 5 febbraio 2022

# astro: aprops of horrific encounters, how to survive inside a (virtual) black hole


<< As (eight stars skirt a black hole 1m times the mass of the Sun) approach, all are stretched and deformed by the black hole's gravity. Some are completely pulled apart into a long stream of gas, a cataclysmic phenomenon called a tidal disruption event. Others are only partially disrupted, retaining some of their mass and returning to their normal shapes after their horrific encounters. >>

<< These simulations, (..) are the first to combine the physical effects of Einstein's general theory of relativity with realistic stellar density models. The virtual stars range from about one-tenth to 10 times the Sun's mass. >>

<< The division between stars that fully disrupt and those that endure isn't simply related to mass. Instead, survival depends more on the star's density. >>

Jeanette Kazmierczak. Scientists fling model stars at a virtual black hole to see who survives. NASA's Goddard Space Flight Center. Nov 26, 2021.


<< This paper introduces a series of papers presenting a quantitative theory for the tidal disruption of main-sequence stars by supermassive black holes (the pericenter-dependence of tidal disruption properties for eight stellar masses (..) and six black hole masses (..). >>

Taeho Ryu, Julian Krolik, et al. Tidal Disruptions of Main-sequence Stars. I. Observable Quantities and Their Dependence on Stellar and Black Hole Mass. ApJ 904 98. Nov 25, 2020.


Also

keyword 'black hole' | 'astro' in FonT



keywords: astro, blackhole, tidal disruption, survival, surviving



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venerdì 4 febbraio 2022

# gst: apropos of apparent erratic dynamics, the self-organization of drops bouncing on a vertically-vibrated surface

<< A drop bouncing on a vertically-vibrated surface may self-propel forward by Faraday waves and travels along a fluid interface. >>

<< A fine anal­ysis of the pairwise density function shows that while being dynamic, time-evolving and presenting many in­dications of a good mixing in the phase space, the sys­tem adopts in average preferred distances which origin has been rationalized by analysing the internal symme­try of the waves. Thus (AA) have shed light numerically on a statistical many-body wave self-organisation in an apparent erratic dynamics. >>

Adrien Hélias, Matthieu Labousse. Statistical self-organization of walking drops. arXiv:2201.07689v1 [cond-mat.soft]. Jan 19, 2022.


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keywords: gst, drops, self-organization, erratic dynamics, erraticity



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lunedì 31 gennaio 2022

# evol: the hypothesis of quasi-stochastic 'jazzy' metamechanics of biological evolution (in Arabidopsis thaliana)


<< Mutations occur when DNA is damaged and left unrepaired, creating a new variation. The scientists wanted to know if mutation was purely random or something deeper. What they found was unexpected. >>️

<< We always thought of mutation as basically random across the genome, (..) It turns out that mutation is very non-random and it's non-random in a way that benefits the plant. It's a totally new way of thinking about mutation. >> Grey Monroe. ️

Study challenges evolutionary theory that DNA mutations are random. UC Davis. Jan 12, 2022.


Monroe JG, Srikant T, et al. Mutation bias reflects natural selection in Arabidopsis thaliana. Nature. doi: 10.1038/ s41586-021-04269-6. Jan 12, 2022.


FonT 

for a long time I have developed the suspicion that the small plant cared for by grandmother on the windowsill could be a not trivial image of (r)evolution ... 

The three ways of the plastoquinone inside the photosystem II complex. May 23, 2017.


Also

keyword 'evolution'  in FonT


keyword 'evolution' | 'evoluzione'  in Notes (quasi-stochastic poetry)



keyword 'jazz' in FonT


keyword 'jazz' in Notes (quasi-stochastic poetry):


keywords: evol, dna, mutations, randomness, quasi-stochasticity, jazz



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