# gst: compression and fracture of ordered and disordered droplet rafts

AA << simulate a two-dimensional array of droplets being compressed between two walls. The droplets are adhesive due to an attractive depletion force. As one wall moves toward the other, the droplet array is compressed and eventually induced to rearrange. The rearrangement occurs via a fracture, where depletion bonds are quickly broken between a subset of droplets. >>

<< For monodisperse, hexagonally ordered droplet arrays, this fracture is preceded by a maximum force exerted on the walls, which drops rapidly after the fracture occurs. >>

<< In small droplet arrays a fracture is a single well-defined event, but for larger droplet arrays, competing fractures can be observed. These are fractures nucleated nearly simultaneously in different locations. >>

AA << also study the compression of bidisperse droplet arrays. The addition of a second droplet size further disrupts fracture events, showing differences between ideal crystalline arrays, crystalline arrays with a small number of defects, and fully amorphous arrays. >>

️

Pablo Eduardo Illing, Jean-Christophe Ono-dit-Biot, et al. Compression and fracture of ordered and disordered droplet rafts. Phys. Rev. E 109, 014610. Jan 17, 2024.

https://journals.aps.org/pre/abstract/10.1103/PhysRevE.109.014610

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

Also:  raft   https://flashontrack.blogspot.com/search?q=raft  

zattera (quasi-stochastic poetry) https://inkpi.blogspot.com/2005/04/1864-onda-di-liberazione.html  

randa (quasi-stochastic poetry) https://inkpi.blogspot.com/search?q=randa

Keywords: gst, drop, droplet, raft, defect, fracture, crack

# behav: mechanics of fire ant rafts as an active self-healing membrane

<< The unique ability of fire ants to form a raft to survive flooding rain has enchanted biologists as well as researchers in other disciplines. (..) a three-dimensional aggregation of fire ants exhibits viscoelasticity with respect to external compression and shearing among numerous unusual mechanical properties. >>️

AA << study the ant raft in its natural form, i.e., composing no more than two layers. This allowed to focus on the cracks that are unique to membranes and see how their patterns are influenced by the fact that these ants are mobile and can self-repair the damage to keep their raft from disintegration. >>️

They << show that vertical and horizontal shaking can also prompt fire ants to aggregate.  (..)  the pull force expedites the alignment of fire ants, in analogy to the effect of an electric field on liquid crystal polymers. >>️

<< One major finding is that the raft can exhibit zero Poisson's ratio without resorting to specific geometry structures. This is enabled by the active recruitment of ants from the top layer to the bottom layer to keep the raft from disintegrating. >>️

️

Chung-Hao Chen, Ting-Heng Hsieh, et al. Formation and mechanics of fire ant rafts as an active self-healing membrane. Phys. Rev. E 109, 014607. Jan 9, 2024. 

https://journals.aps.org/pre/abstract/10.1103/PhysRevE.109.014607

David Ehrenstein. Material Properties of Fire-Ant Rafts. Physics 17, s5. Jan 9. 2024. 

https://physics.aps.org/articles/v17/s5

Also:  raft   https://flashontrack.blogspot.com/search?q=raft  

zattera (quasi-stochastic poetry) https://inkpi.blogspot.com/2005/04/1864-onda-di-liberazione.html  

randa (quasi-stochastic poetry) https://inkpi.blogspot.com/search?q=randa

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

Keywords behavior, behaviour, ant, raft, self-healing

# gst: self-repelling species could self-organize.

<< Catalytically active particles form clusters when they respond not only to their own chemical targets but to those of other catalysts, too. >>️

AA  << show that the phenomenon of self-organization depends strongly on the network topology. >>️

They << modeled a three-species system (..) systems where each species responds chemotactically only to its own substrate cannot self-organize unless one species is self-attracting. >>️

<< Next, they developed a model that allowed species to respond to both their substrates and their products. Pair interactions between different species in this more complex model drove an instability that spread throughout the three-species system, causing the catalysts to clump together. Surprisingly, this self-organization process occurred even among particles that were individually self-repelling. >>️

Rachel Berkowitz. Self-Repelling Species Still Self-Organize. Physics 16, s128. Sept 19, 2023. 

https://physics.aps.org/articles/v16/s128

Vincent Ouazan-Reboul, Ramin Golestanian, Jaime Agudo-Canalejo. Network effects lead to self-organization in metabolic cycles of self-repelling catalysts. Phys. Rev. Lett. 131, 128301. Sep 19, 2023. 

http://dx.doi.org/10.1103/PhysRevLett.131.128301

Also: self-assembly, network, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, self-assembly, network,  topology.

# gst: the hypothesis of a new type of rogue waves.

<< Much attention of researchers has been paid in the recent decades to the study of rogue waves. Various mechanisms of formation of these waves were suggested. The occurrence of rogue waves is most often investigated on the basis of the mechanisms of modulation instability and superposition of waves. In both cases, an evolution of rogue waves takes place against the background of a wave field, which is reflected in the definitions of such waves. In this report, the localized waves developed in the absence of the background wave fields are considered. At the same time, their dynamics corresponds to the dynamics of rogue waves that ”appear from nowhere and disappear without a trace”. >>️

<< The waves of this type are distinguished by the fact that their dynamics occur on the zero background. This implies that rogue waves presented here are formed solely due to the nonlinear focusing. >>️

N.V. Ustinov. New type of rogue waves. arXiv:2310.17254v1 [nlin.SI]. Oct 26, 2023.  

https://arxiv.org/abs/2310.17254

Chaos, Solitons & Fractals V. 179, Feb 2024, 114467. https://www.sciencedirect.com/science/article/abs/pii/S0960077924000183

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

Keywords: gst, waves, rogue waves 

# gst: the fascinating possibility of two black holes masquerading as one.

<< a pair of black holes whose mutual attraction is balanced by the cosmic expansion would look the same to a distant observer as a single isolated black hole. >>

Oscar J.C. Dias and coll. << point out that when the black holes are allowed to rotate, it is possible that their spin interaction may stabilize the solutions. This raises the fascinating possibility of having an isolated pair of solar-mass black holes in our Universe, balancing happily a few hundred light years apart and impossible to distinguish from a single black hole from far away. >>

<< If these black holes are set up in precisely the correct way, they sit in an unstable equilibrium, akin to a pen balanced on its pointed end. Any disturbance will ruin this perfect balance. >>

Toby Wiseman. Two Black Holes Masquerading as One. Physics 16, 164. Sep 25, 2023. 

https://physics.aps.org/articles/v16/164

Oscar J. C. Dias, Gary W. Gibbons, et al. Static Black Binaries in de Sitter Space. Phys. Rev. Lett. 131, 131401. Sep 25, 2023.

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.131.131401

Also: black hole, astrophysics, in: https://www.inkgmr.net/kwrds.html 

Keywords: gst, black hole, astrophysics

# life: simnotrelvir, a Chinese pill anti covid-19

<< A drug called simnotrelvir speeds up recovery from mild to moderate COVID-19 by about 1.5 days, relieving symptoms such as fever, cough and runny nose.  >>

<< Whether it can help people who are at high risk of hospitalization and death from COVID-19 is still unclear. >>️️

Saima Sidik. Potent new pill provides COVID relief for the masses. Nature. doi: 10.1038/d41586-024-00117-5. Jan 17,  2024. 

https://www.nature.com/articles/d41586-024-00117-5

Bin Cao, Yeming Wang, et al. Oral Simnotrelvir for Adult Patients with Mild-to-Moderate Covid-19. N Engl J Med 2024; 390:230-241. doi: 10.1056/NEJMoa2301425. Jan 18, 2024.

https://www.nejm.org/doi/10.1056/NEJMoa2301425

FonT: if it is (another) 'pastroky', you can redirect yourself towards an alcohol plus peroxide solution... just to put the classic patch on it. 

Also:  a proposito di '1or2achoos' (da Wuhan (?)), qui la cronologia. FonT. Oct 4, 2023. 

https://flashontrack.blogspot.com/2023/10/life-proposito-di-1or2achoos-da-wuhan.html

Also: 1or2achoos, sars, covid, virus, pastroky, in:   https://www.inkgmr.net/kwrds.html

Keywords: life, virus, flu, coronavirus,  sarscov2, covid19, 1or2achoos, mask

# gst: pseudo epileptic seizures in self-organized bistability

<< Self-organized bistability (SOB) stands as a critical behavior for the systems delicately adjusting themselves to the brink of bistability, characterized by a first-order transition. >>️

(AA) << embark on a theoretical exploration that extends the boundaries of the SOB concept on a higher-order network (implicitly embedded microscopically within a simplicial complex) while considering the limitations imposed by coupling constraints. >>️

AA << use continuous synchronization diagrams and statistical data from spontaneous synchronized events to demonstrate the crucial role SOB plays in initiating and terminating temporary synchronized events. (They) show that under weak coupling consumption, these spontaneous occurrences closely resemble the statistical traits of the epileptic brain functioning. >>

️

Md Sayeed Anwar, Nikita Frolov, Alexander E. Hramov, Dibakar Ghosh. Self-organized bistability on globally coupled higher-order networks. arXiv: 2401.02825v1 [nlin.AO]. Jan 5, 2024.

https://arxiv.org/abs/2401.02825

Also: transition, self-assembly, brain, in: https://www.inkgmr.net/kwrds.html

Keywords: gst, transition, self-assembly, bistability, self-organized bistability, brain, epileptic seizure