# gst: local elastic properties of strongly disordered matter

<< The local elastic properties of strongly disordered material are investigated using the theory of correlated random matrices. A significant increase in stiffness is shown in the interfacial region, the thickness of which depends on the strength of disorder. It is shown that this effect plays a crucial role in nanocomposites, in which interfacial regions are formed around each nanoparticle. >>️

D. A. Conyuh, A. A. Semenov, Y. M. Beltukov. Effective elastic moduli of composites with a strongly disordered host material. Phys. Rev. E 108, 045004. Oct 20, 2023. 

https://journals.aps.org/pre/abstract/10.1103/PhysRevE.108.045004

Also: elastic, noise, particle, nano, in https://www.inkgmr.net/kwrds.html

Keywords: gst, elastic, noise, particle, nano

# gst: quantum jamming on the macroscopic scale

 << In the presence of kinetic constraints, quasiparticles describing the behavior of an ordered arrangement of quantum spins can get “stuck” as their density increases. Because of its similarity to the formation of amorphous solids, this situation can be interpreted as the quantum analog of jamming. Jammed states are intrinsically unstable and small perturbations produce unusual nonequilibrium dynamics. >> 

 AA << show that quantum jamming is a mechanism to make microscopic phenomena visible at a macroscopic scale: A single impurity produces a permanent change in the state, and a few impurities leave an imprint of their scattering properties and bound states. >> 

Maurizio Fagotti. Quantum Jamming Brings Quantum Mechanics to Macroscopic Scales. Phys. Rev. X 14, 021015. Apr 23, 2024.

https://journals.aps.org/prx/abstract/10.1103/PhysRevX.14.021015

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

Keywords: gst, particle, jamming

# gst: transitions in disordered medium.

AA << study computationally the dynamics of forced, Brownian particles through a disordered system. As the concentration of mobile particles and/or fixed obstacles increase, (AA) characterize the different regimes of flow and address how clogging develops. >>️

AA << show that clogging is preceded by a wide region of anomalous transport, characterized by a power law decay of intermittent bursts. (..) this abnormal flow region is characterized by a coexistence between mobile and arrested particles, and their relative populations change smoothly as clogging is approached. >>

️

Sergi G. Leyva, Ignacio Pagonabarraga. Clogging transition and anomalous transport in driven suspensions in a disordered medium. Phys. Rev. E 109, 014618. Jan 31, 2024.

https://journals.aps.org/pre/abstract/10.1103/PhysRevE.109.014618

img:  https://twitter.com/PhysRevE/status/1753068208586711072   

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

Keywords: gst, transition, particle, disorder

# gst: stochastic resonance mediated by optimal noise level values; transport of colloidal particles induced by substrate concentration oscillations.

AA << show the existence of a  stochastic resonant regime in the transport of active colloidal particles under confinement. The periodic addition of substrate to the system causes the spectral amplification to exhibit a maximum for an optimal noise level value. The consequence of this is that particles can travel longer distances with lower fuel consumption. The stochastic resonance phenomenon found allows the identification of optimal scenarios for the transport of active particles, enabling them to reach regions that are otherwise difficult to access, and may therefore find applications in transport. >>️

J. D. Torrenegra-Rico, A. Arango-Restrepo, J. M. Rubi. Optimal transport of active particles induced by substrate concentration oscillations. Phys. Rev. E 108, 014134. July 28, 2023.

https://journals.aps.org/pre/abstract/10.1103/PhysRevE.108.014134

Img: https://twitter.com/PhysRevE/status/1687119409096089602

Also: particle, colloids, noise, in:  https://www.inkgmr.net/kwrds.html

Keywords: gst, particle, colloids, noise, stochastic resonance, substrate oscillation

# gst: the strong impact on nanosheets by the weak van der Waals force

<< Van der Waals is a weak force that allows neutral molecules to attract one another through randomly fluctuating dipoles, depending on distance. Though small, its effects can be seen in the macro world, like when geckos walk up walls. >> 

<< Van der Waals forces are everywhere and, essentially, at the nanoscale everything is sticky, (..) When you put a large, flat particle on a large, flat surface, there's a lot of contact, and it's enough to permanently deform a particle that's really thin and flexible. >> 

Matt Jones. 

<< the ubiquitous, "weak" van der Waals force was sufficient to indent a rigid silver nanosheet. The phenomenon suggests possible applications in nanoscale optics or catalytic systems. >>

<< In further experiments, (..) nanospheres could be used to control the shape of the deformation, from single ridges when two spheres are close, to saddle shapes or isolated bumps when the spheres are farther apart. >> 

Mike Williams. Weak force has strong impact on nanosheets. Rice University. Dec 15, 2020. 

https://phys.org/news/2020-12-weak-strong-impact-nanosheets.html

Sarah M. Rehn, Theodor M. Gerrard-Anderson, et al. Mechanical Reshaping of Inorganic Nanostructures with Weak Nanoscale Forces. Nano Lett. doi: 10.1021/ acs.nanolett.0c03383. Dec 10, 2020. 

https://pubs.acs.org/doi/10.1021/acs.nanolett.0c03383  

Also

keyword 'van der Waals' in FonT

https://flashontrack.blogspot.com/search?q=van+der+Waals

# gst astro: when a superbubble can generate trains of shock waves

<< Sixty-seven million light-years away, a galaxy is blowing enormous bubbles. We know what they are. Known as nuclear superbubbles, the structures are likely created by the supermassive black hole in the galaxy's centre. Now, thanks to new data, we know something incredible is occurring inside them. >>

<< Observations from NASA's Chandra X-ray Observatory of spiral galaxy NGC 3079 have revealed that the bubbles are actually a huge cosmic particle accelerator, producing energetic high-speed particles around their edges.  >>

<< As the bubbles expand into the surrounding gas of the interstellar medium, they generate shock waves, which in turn produce tangled magnetic fields. (..)  particles ricochet around these shock magnetic fields; when they pass through the shock front, they get an acceleration boost.  >>

Michelle Starr. Astronomers Have Found 'Superbubbles' Producing Shock Waves in Another Galaxy.  Mar 4, 2019.

https://www.sciencealert.com/colossal-bubbles-blown-by-a-supermassive-black-hole-are-a-cosmic-particle-accelerator

Jiang-Tao Li, Edmund Hodges-Kluck, et al. Detection of non-thermal hard X-ray emission from the "Fermi bubble" in an external galaxy.  ApJ in press. arXiv:1901.10536v1 [astro-ph.HE] Jan 31, 2019.

https://arxiv.org/abs/1901.10536

# gst: when a turbulence can be confined

<< Turbulence is hard to control. Its ephemeral nature prevents us from treating it as an ordinary state of matter. Here (AA) create a stationary and isolated blob of turbulence using only elemental building blocks: vortex rings.  The turbulence is confined in a spherical region, surrounded by a quiescent environment, initiated and sustained by vortex rings. Crucially, vortex rings can be endowed with conserved quantities such as energy and helicity, which can be transferred to the turbulent state. Using 2D particle image velocimetry and 3D particle tracking velocimetry, (AA) demonstrate how confinement of turbulence occurs when vortex rings repeatedly collide, in contrast to coherent vortex reconnections. The pathlines depict the difference between these states of flow. >>️

Takumi Matsuzawa, Noah P. Mitchell, Stéphane Perrard, William T. M. Irvine. Turbulence through sustained vortex ring collisions. Phys. Rev. Fluids 8, 110507. Nov 16, 2023.

https://journals.aps.org/prfluids/abstract/10.1103/PhysRevFluids.8.110507

75TH ANNUAL MEETING OF THE APS DIVISION OF FLUID DYNAMICS (NOVEMBER 20, 2022 — NOV 22, 2022). V0008: Turbulence through sustained vortex ring collisions. 

https://doi.org/10.1103/APS.DFD.2022.GFM.V0008

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

Keywords: gst, turbulence, vortex, vortex ring collisions

# gst: tracking tiny particles

<< Kymographs are graphical representations of spatial position over time, which are often used in biology to visualise the motion of fluorescent particles, molecules, vesicles, or organelles moving along a predictable path. >>

AA << developed KymoButler, a Deep Learning-based software to automatically track dynamic processes in kymographs. (They) demonstrate that KymoButler performs as well as expert manual data analysis on kymographs with complex particle trajectories from a variety of different biological systems. >>

Maximilian AH Jakobs, Andrea Dimitracopoulos, Kristian Franze.  KymoButler, a deep learning software for automated kymograph analysis.
eLife. doi: 10.7554/eLife.42288.  Aug 13, 2019.  https://elifesciences.org/articles/42288

<< We hope our tool will prove useful for others involved in analysing small particle movements, whichever field they may work in, >> Kristian Franze

Machine learning tool improves tracking of tiny moving particles. eLife. Aug 13, 2019.   https://m.techxplore.com/news/2019-08-machine-tool-tracking-tiny-particles.html 

# gst: intertwining order, disorder, and hierarchy

<< Nature hosts a wealth of materials showcasing intricate structures intertwining order, disorder, and hierarchy, delivering resilient multifunctionality surpassing perfect crystals or simplistic disordered materials. The engineering of such materials through nanoparticle assembly represents a burgeoning field, poised with potential to yield sustainable material systems rivaling or exceeding biological functionalities. >>

AA << review delineates the fundamental concept of complexity in the context of nanoscale materials. >>

Xiaoming Mao, Nicholas Kotov. Complexity, Disorder, and Functionality of Nanoscale Materials. arXiv: 2401.09567v1 [cond-mat.soft]. Jan 17, 2024. 

https://arxiv.org/abs/2401.09567

Also: nano, particle, order, disorder, in  https://www.inkgmr.net/kwrds.html

Keywords: nano, particle, order, disorder 

# gst: pulsating active matter.

<< the mechanical pulsation of locally synchronized particles is a generic route to propagate deformation waves. >>

️

AA << consider a model of dense repulsive particles whose activity drives periodic change in size of each individual. >>️

They << show that the competition between repulsion and synchronization triggers an instability which promotes a wealth of dynamical patterns, ranging from spiral waves to defect turbulence. >>️

Yiwei Zhang, Etienne Fodor. Pulsating Active Matter. Phys. Rev. Lett. 131, 238302. Dec 8, 2023. 

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.131.238302

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

Keywords: gst, waves, particle, transition, instability, turbulence

# phys: three forms of ambiguity in the definition of entanglement

<< A more general definition (of entanglement) was published by Thaller, (B. Thaller, Advanced Visual Quantum Mechanics, (Springer 2005) p218) "A state of a compound system is called entangled if it cannot be written as a single tensor product of subsystem states. A state in the product form is called unentangled or separable."  >>

The paper << discusses experiments with single-particle systems, some of whose states appear to be entangled. (..) Three forms of ambiguity are discussed. The choice of state-space and its dimensions is a matter of taste. There is not an a-priori natural partitioning of the state-space. The observables are not necessarily experimentally accessible and only determined by theory-laden extrapolation from experimental results. >>

Robert Shaw. Single-particle entanglement and three forms of ambiguity. arXiv:1912.11349v1 [physics.hist-ph]. Dec 22, 2019

https://arxiv.org/abs/1912.11349

# gst: inertial particles within co-rotating dusty vortices

 << dispersed particles with moderate inertia cause the vortex pair to push apart to a separation nearly twice as large as the initial separation. >>

 

 << antisymmetric vorticity generated by particles flung out of the rotational cores causes the vortex pair repulsion. Eventually, the two dusty vortices merge into a single vortex with most particles accumulating outside the core similar to the dusty Lamb-Oseen vortex described in Shuai & Kasbaoui (2022) >>

 

 << For weakly inertial particles, (AA) find that the merger dynamics follow the same mechanics as those of a single-phase flow, albeit with a density that must be adjusted to match the mixture density. >>

 

<< Lastly, highly inertial particles tend to fragment the vortex cores leading to murky merger dynamics. >>

Shuai Shuai, Anubhab Roy, M. Houssem Kasbaoui. The merger of co-rotating vortices in dusty flows. arXiv: 2307.05413v1 [physics.flu-dyn]. Jul 11, 2023. 

https://arxiv.org/abs/2307.05413

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

Keywords: gst, particle, vortex 

# e-web-sec: IoT comes to (hack to) the Masses; the begin

<< Internet of Things, aka “IoT” is all the rage. You know, all these new connected things like Nest thermostats, Hue lights, digital door locks and other devices that have lights, sensors, motors or switches, along with a small computer and are connected to the Internet.>>

<< On Monday (Feb. 8), building IoT-based devices is going to get a lot easier and cheaper thanks to Particle.io >>

Robert Scoble. Internet of Things Comes to the Masses. February 12, 2016

http://www.kurzweilai.net/robert-scoble-internet-of-things-comes-to-the-masses

# gst: apropos of 'disordered interactions', localization and dissociation of bound states and mapping to chaotic billiards concerning two particles on a chain

AA << consider two particles hopping on a chain with a contact interaction between them. At strong interaction, there is a molecular bound state separated by a direct gap from a continuous band of atomic states. Introducing weak disorder in the interaction, the molecular state becomes Anderson localized (exponential localization of all energy eigenstates,). At stronger disorder, part of the molecular band delocalizes and dissociates due to its hybridization to the atomic band. (AA) characterize these different regimes by computing the density of states, the inverse participation ratio, the level-spacing statistics and the survival probability of an initially localized state.  >>️

<< The atomic band is best described as that of a rough billiard for a single particle on a square lattice that shows signatures of quantum chaos. In addition to typical ``chaotic states'', (AA) find states that are localized along only one direction. These ``separatrix states'' are more localized than chaotic states, and similar in this respect to scarred states, but their existence is due to the separatrix iso-energy line in the interaction-free dispersion relation, rather than to unstable periodic orbits. >> 

Hugo Perrin, Janos K. Asboth, et al.  Two particles on a chain with disordered interaction: Localization and dissociation of bound states and mapping to chaotic billiards. arXiv: 2106.09603v1. Jun 17, 2021. 

https://arxiv.org/abs/2106.09603

# gst: another way for the evaporation of a black hole

<< The quantum fluctuations that pervade empty space spontaneously give birth to pairs of particles and antiparticles. Ordinarily, these pairs annihilate so promptly that their existence is virtual. But a powerful field can pull a pair’s members apart for long enough that their existence becomes real. Now (AA) have proposed that particle pairs can be brought into existence by the immense gravitational tidal forces around a black hole (..).>>

<< If the vacuum is stable, all pairs that are created are also destroyed. But a strong field destabilizes the vacuum, makes some paths more likely than others, and leads to a deficit of pairs that recombine. The deficit is balanced by a net outflow of real particles, which, in the case of a black hole’s gravitational field, leads to the black hole’s eventual evaporation. >>️

Charles Day. Another Way for Black Holes to Evaporate. Physics 16, s77. Jun 2, 2023. 

https://physics.aps.org/articles/v16/s77

Michael F. Wondrak, Walter D. van Suijlekom, Heino Falcke. Gravitational Pair Production and Black Hole Evaporation. Phys. Rev. Lett. 130, 221502. Jun 2, 2023. 

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.130.221502

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

Keywords: gst, black hole, astrophysics

# phys: here an immersive tour of the biggest Collider (LHC) ... now shutted down - e.g. Disneyland at rest, by Dennis - for two years of upgrades

<< The largest machine ever built is shutting down for two years of upgrades. Take an immersive tour of the collider and study the remnants of a Higgs particle in augmented reality. >>

It's Intermission for the Large Hadron Collider. NYT. Dec 21, 2018

https://www.nytimes.com/interactive/2018/12/21/science/cern-large-hadron-collider-ar-ul.html

<< If you're a physicist this is better than Disneyland >>

Dennis Overbye (@overbye). Dec 21, 2018.

https://twitter.com/overbye/status/1076194249782251520

Also

<<  N. sulla reticella zenana dall' Efodi ritmici  / ...  ritmici a s-tecche velaccine nell' eprom sonde / montate monatte in perifrastiche coll' adatti snodi dove s' addensano a metastrati l'epistrofi (..)  >>

2153 - cracker tendenziali (around a matter-sucking maelstrom). Apr 04, 2008.

https://inkpi.blogspot.com/2008/04/cracker-tendenziali-around-matter.html

# gst: anisotropic active depletion around a self-propelled non-interactive colloids; three characteristic states could be identified.

<< Active colloids in a bath of inert particles of smaller size cause anisotropic depletion. >>️

Here AA << combine mesoscale hydrodynamic simulation as well as theoretical analysis to examine the physical origin for the active depletion around a self-propelled noninteractive colloid. >>️

Their << results elucidate that the variable hydrodynamic effect critically governs the microstructure of the depletion zone. Three characteristic states of anisotropic depletion are identified, depending on the strength and stress of activity. >>️

<< Furthermore, (AA) demonstrate that such depletion in nonequilibrium results in various clusters with ordered organization of squirmers, which follows a distinct principle contrary to that of the entropy scenario of depletion in equilibrium. >>

️

Lijun Dai, Haixiao Wan, et al. Hydrodynamic Anisotropy of Depletion in Nonequilibrium. Phys. Rev. Lett. 131, 134002. Sep 27, 2023. 

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.131.134002

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

Keywords: gst, particles, colloids, depletion, squirmers, self-propulsion systems

# phys: the strange world of quantum mechanics

<< In the normal world, an object such as a baseball can only be in one place at one time. But in the quantum world, a particle such as an electron can occupy an infinite number of places at the same time, existing in what physicists call a superposition of multiple states. >>

<< in the quantum world, two individual particles, such as photons can be entangled, such that the mere act of sensing one photon with a detector instantaneously forces the other photon, no matter how far away, to assume a particular state. >>

<< evidence is mounting from the world of plant physiology that some biological processes that rely on quantum superposition occur at normal temperatures, raising the possibility that unimaginably strange world of quantum mechanics may indeed intrude into the every day workings of other biological systems, such as our nervous systems. >>

<< Evolution, in its relentless quest to engineer the most energy-efficient life forms, appears to have ignored physicists’ belief that useful quantum effects can’t happen in the warm, wet environments of biology. >>

Eric Haseltine. Why You Should Care About Quantum Neuroscience.
Hints of an incredibly exciting future. Dec 31, 2018

https://www.psychologytoday.com/us/blog/long-fuse-big-bang/201812/why-you-should-care-about-quantum-neuroscience

FonT

davanti a una immagine di "enzima allosterico" qualsiasi bravo scientist sa immediatamente con cosa avra' a che fare: avra' a che fare con il caos, vale a dire con oggetti che possono generare dinamiche senz'altro confinate purtuttavia bizzarre, jazz, funky, fuzzy; invece davanti a concetti quali i due citati sopra (superposition, entanglement), e gli ipotetici effetti immaginabili all'interno di strutture biologiche, neurobiologiche, informatiche, ho idea che chiunque potrebbe sentirsi vagamente disorientato (qui si sottolinea "vagamente") ...

# s-esobio: self-assembled azotosomes by convective activity, a kind of proto-life on Titan.

<< vinyl cyanide (C2H3CN; also known as acrylonitrile or propenenitrile) would be the best candidate species for the formation of (..) cell-like membranes, known as “azotosomes” >>

AA << report the first spectroscopic detection of vinyl cyanide in Titan’s atmosphere, obtained using archival data from the Atacama Large Millimeter/submillimeter Array (ALMA), collected from February to May 2014 >>

AA << detect the three strongest rotational lines of C2H3CN in the frequency range of 230 to 232 GHz, each with >4σ confidence >>

the << production rate of vinyl cyanide and its saturation mole fraction imply the availability of sufficient dissolved material to form ~107 cell membranes/cm3 in Titan’s sea Ligeia Mare (Titan's second largest liquid body) >>

<< Reactions of hydrocarbons with hydrogen, both readily available on Titan, release energy, which could provide support for methanogenic life. The sedimentation time of atmospheric organics depends on the particle size and convective activity in the troposphere. This coupling of Titan’s atmosphere and surface completes the picture regarding the astrobiological importance of (..) detection of vinyl cyanide in Titan’s middle/upper atmosphere >>

Maureen Y. Palmer, Martin A. Cordiner, et al. ALMA detection and astrobiological potential of vinyl cyanide on Titan. Science Advances  28 Jul 2017: Vol. 3, no. 7, e1700022
doi: 10.1126/sciadv.1700022

http://advances.sciencemag.org/content/3/7/e1700022.full

# gst: a new type of vortex in the flight of a dandelion

<< Wind-dispersed plants have evolved ingenious ways to lift their seeds >>

AA << visualized the flow around dandelion seeds, uncovering an extraordinary type of vortex. This vortex is a ring of recirculating fluid, which is detached owing to the flow passing through the pappus. >>

<< The discovery of the separated vortex ring provides evidence of the existence of a new class of fluid behaviour around fluid-immersed bodies that may underlie locomotion, weight reduction and particle retention in biological and manmade structures. >>

Cathal Cummins, Madeleine Seale, et al. A separated vortex ring underlies the flight of the dandelion. Nature 2018; 562: 414–8. doi: 10.1038/s41586-018-0604-2.

https://www.nature.com/articles/s41586-018-0604-2

<< When dandelion seeds fly, a ring-shaped air bubble forms as air moves through the bristles, enhancing the drag that slows their descent. >>

Dandelion seeds reveal newly discovered form of natural flight. University of Edinburgh. Oct 17, 2018.

https://m.phys.org/news/2018-10-dandelion-seeds-reveal-newly-natural.html