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Visualizzazione post con etichetta self-assembly. Mostra tutti i post
Visualizzazione post con etichetta self-assembly. Mostra tutti i post

mercoledì 2 luglio 2025

# gst: turbulence spreading and anomalous diffusion on combs.

<< This (AA) paper presents a simple model for such processes as chaos spreading or turbulence spillover into stable regions. In this simple model the essential transport occurs via inelastic resonant interactions of waves on a lattice. The process is shown to result universally in a subdiffusive spreading of the wave field. The dispersion of this spreading process is found to depend exclusively on the type of the interaction process (three- or four-wave), but not on a particular underlying instability. The asymptotic transport equations for field spreading are derived with the aid of a specific geometric construction in the form of a comb. >>

<< The results can be summarized by stating that the asymptotic spreading proceeds as a continuous-time random walk (CTRW) and corresponds to a kinetic description in terms of fractional-derivative equations. The fractional indexes pertaining to these equations are obtained exactly using the comb model. >>

<< A special case of the above theory is a situation in which two waves with oppositely directed wave vectors couple together to form a bound state with zero momentum. This situation is considered separately and associated with the self-organization of wave-like turbulence into banded flows or staircases. >>

<< Overall, (AA) find that turbulence spreading and staircasing could be described based on the same mathematical formalism, using the Hamiltonian of inelastic wave-wave interactions and a mapping procedure into the comb space. Theoretically, the comb approach is regarded as a substitute for a more common description based on quasilinear theory. Some implications of the present theory for the fusion plasma studies are discussed and a comparison with the available observational and numerical evidence is given. >>

Alexander V. Milovanov, Alexander Iomin, Jens Juul Rasmussen. Turbulence spreading and anomalous diffusion on combs. Phys. Rev. E 111, 064217 – Published 24 June, 2025

Also: waves, turbulence, walk, self-assembly, instability, chaos, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, waves, turbulence, walk, self-assembly, instability, chaos, comb model, inelastic resonant interactions, inelastic wave-wave interactions, continuous-time random walk, self-organization of wave-like turbulence, Lévy flights, Lévy walks

lunedì 23 giugno 2025

# gst: active drive towards elastic spinodals


<< Active matter, exemplified by adaptive living materials such as the actomyosin cytoskeleton, can navigate material parameter space, leading to unconventional mechanical responses. In particular, it can self-drive toward elastic spinodal regimes, where inhomogeneous floppy modes induce elastic degeneracy and enable a controlled interplay between rigidity loss and recovery. Proximity to such marginal states leads to stress localization and the formation of force chains that can be actively assembled and disassembled. >> 

Here AA << extend the classical notion of spinodal states to active solids and demonstrate how these extreme mechanical regimes can be actively accessed. Moreover, (They) show that in a nonlinear setting, crossing elastic spinodals generates new energy wells and makes force channeling an intrinsic feature of the emerging microstructure. >>

Ayan Roychowdhury, Madan Rao, Lev Truskinovsky. Active drive towards elastic spinodals. Phys. Rev. E 111, 065416. Jun 20, 2025.

arXiv: 2403.17517v3 [cond-mat.soft]. May 20, 2025.

Also: elastic, transition, instability, disorder & fluctuations, self-assembly, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, transitions, instability, disorder & fluctuations, active matter, elasticity, elastic forces, elastic deformation, elastic spinodals, self-assembly.

venerdì 13 giugno 2025

# gst: self-organization to multicriticality; when a system can self-organize to a new type of phase transition while staying on the verge of another.

<< Self-organized criticality is a well-established phenomenon, where a system dynamically tunes its structure to operate on the verge of a phase transition. Here, (AA) show that the dynamics inside the self-organized critical state are fundamentally far more versatile than previously recognized, to the extent that a system can self-organize to a new type of phase transition while staying on the verge of another. >>

<< In this first demonstration of self-organization to multicriticality, (AA) investigate a model of coupled oscillators on a random network, where the network topology evolves in response to the oscillator dynamics. (They) 
 show that the system first self-organizes to the onset of oscillations, after which it drifts to the onset of pattern formation while still remaining at the onset of oscillations, thus becoming critical in two different ways at once. >>
 
<< The observed evolution to multicriticality is robust generic behavior that (AA) expect to be widespread in self-organizing systems. Overall, these results offer a unifying framework for studying systems, such as the brain, where multiple phase transitions may be relevant for proper functioning.>>

Silja Sormunen, Thilo Gross, Jari Saramäki. Self-organization to multicriticality. arXiv: 2506.04275v1 [nlin.AO]. Jun 4, 2025. 

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

Keywords: gst, network, random, self-assembly, transition, phase transition, multiple phase transitions, self-organizing systems, self-organized criticality, multicriticality, brain.

giovedì 8 maggio 2025

# gst: apropos of adaptation of simple organisms to changing environments, self-organization and memory in a disordered entity to random driving.

AA << consider self-organization and memory formation in a mesoscopic model of an amorphous solid subject to a protocol of random shear confined to a strain range ±𝜖max. (They) develop proper readout protocols to show that the response of the driven system self-organizes to retain a memory of the strain range, which can be subsequently retrieved. >>

AA << findings generalize previous results obtained upon oscillatory driving and suggest that self-organization and memory formation of disordered materials can emerge under more general conditions, such as a disordered system interacting with its fluctuating environment. Self-organization results in a correlation between the dynamics of the system and its environment, providing thereby an elementary mechanism for sensing. >>

AA << conclude by discussing (Their)  results and their potential relevance for the adaptation of simple organisms lacking a brain to changing environments. >>

Muhittin Mungan, Dheeraj Kumar, et al. Self-Organization and Memory in a Disordered Solid Subject to Random Driving. Phys. Rev. Lett. 134, 178203. April 30, 2025.

arXiv: 2409.17096v2 [cond-mat.soft]. 

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

Keywords: gst, disorder, fluctuations, self-assembly, self-organization, transitions

venerdì 24 gennaio 2025

# gst: scattered waves fuel emergent activity.


<< Active matter taps into external energy sources to power its own processes. Systems of passive particles ordinarily lack this capacity, but can become active if the constituent particles interact with each other nonreciprocally. By reformulating the theory of classical wave-matter interactions, (AA) demonstrate that interactions mediated by scattered waves generally are not constrained by Newton's third law. The resulting center-of-mass forces propel clusters of scatterers, enabling them to extract energy from the wave and rendering them active. This form of activity is an emergent property of the scatterers' state of organization and can arise in any system where mobile objects scatter waves. Emergent activity flips the script on conventional active matter whose nonreciprocity emerges from its activity, and not the other way around. >>

AA << combine theory, experiment, and simulation to illustrate how emergent activity arises in wave-matter composite systems and to explore the phenomenology of emergent activity in experimentally accessible models. These preliminary studies suggest that heterogeneity is a singular perturbation to the dynamics of wave-matter composite systems, and induces emergent activity under all but the most limited circumstances. >>️

Ella M. King, Mia C. Morrell, et al. Scattered waves fuel emergent activity. Phys. Rev. Research 7, 013055. Jan 15, 2025

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

Keywords: gst, waves, particle, self-assembly


sabato 18 gennaio 2025

# gst: traveling strings of active dipolar colloids.

AA << study an intriguing new type of self-assembled active colloidal polymer system in 3D. It is obtained from a suspension of Janus particles in an electric field that induces parallel dipoles in the particles as well as self-propulsion in the plane perpendicular to the field. >>

<< At low volume fractions, in experiment, the particles self-assemble into 3D columns that are self-propelled in 2D. Explicit numerical simulations combining dipolar interactions and active self-propulsion find an activity dependent transition to a string phase by increasing dipole strength. >>

AA << classify the collective dynamics of strings as a function of rotational and translational diffusion. (..) (They) also discover long range correlations of the fluctuations along the string contour that grow with the active persistence time, a purely active effect that disappears in the thermal limit. >>

Xichen Chao, Katherine Skipper, et al. Traveling Strings of Active Dipolar Colloids. Phys. Rev. Lett. 134, 018302. Jan 6, 2025. 

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

Keywords: gst, particle, colloids, self-assembly, Janus, polymers, strings, transition


giovedì 2 gennaio 2025

# gst: self-organized critical dynamic on the Sierpinski carpet.

<< Self-organized criticality is a dynamical system property where, without external tuning, a system naturally evolves towards its critical state, characterized by scale-invariant patterns and power-law distributions.  >>️

In this paper, AA << explored a self-organized critical dynamic on the Sierpinski carpet lattice, a scale-invariant structure whose dimension is defined as a power law with a noninteger exponent, i.e., a fractal. To achieve this, (They) proposed an Ising–bond-correlated percolation model as the foundation for investigating critical dynamics.  >>️

<< Within this framework, (AA) outlined a feedback mechanism for critical self-organization and followed an algorithm for its numerical implementation. The results obtained from the algorithm demonstrated enhanced efficiency when driving the Sierpinski carpet towards critical self-organization compared to a two-dimensional lattice.  >>️

Viviana Gomez, Gabriel Tellez. Self-organized critical dynamic on the Sierpinski carpet. Phys. Rev. E 110, 064141. Dec 20, 2024.

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

Keywords: gst, self-assembly, criticality, self-organized critical dynamics, transitions.


sabato 14 dicembre 2024

# gst: self-organized chimera states in pulse-coupled oscillator systems.

<< Coupled oscillator systems can lead to states in which synchrony and chaos coexist. These states are called “chimera states.” >>
AA << study a variation of a pulse-coupled oscillator (PCO) model that has been shown to produce chimera states, demonstrate that it reproduces several of the expected chimera properties, like the formation of multiple heads and the ability to control the natural drift that Kuramoto's chimera states experience in a ring, and explain how chimera states emerge. >>️

<< Three notable aspects of chimeras in our PCO networks (with time-discrete coupling) are the absence of firing events from the tail (which still almost synchronize their phases), the reliable onset of the phenomenon from virtually any initial configuration, and the lack of a superimposed structure (e.g., artificially splitting the population into subgroups) and thus the self-organized nature of the phenomenon. >>️

Arke Vogell, Udo Schilcher, et al. Chimera states in pulse-coupled oscillator systems. Phys. Rev. E 110, 054214. Nov 26, 2024.

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

Keywords: gst, chimera, self-assembly, chaos, network 


giovedì 21 novembre 2024

# gst: self-organized target wave chimeras from asynchronous oscillators in reaction-diffusion media

<< An important development in nonlinear dynamics is the discovery of chimera states that represent the coexistence of synchronized and desynchronized activity in populations of identically coupled oscillators. >>

 Here, AA << unveil a novel chimera state called “self-organized target wave chimera” in reaction-diffusion media where synchronized target waves spontaneously emerge from a pacemaker composed of asynchronous oscillators. This regime contrasts with a widely accepted perspective that synchronized target waves can be generated only by the individuals, which comprise the pacemaker, behaving in a synchronized manner. >>

AA << characterize the features of self-organized target wave chimeras and present a phase diagram of existence of such a regime. >>

Bing-Wei Li, Jie Xiao, et al. Self-Organized Target Wave Chimeras in Reaction-Diffusion Media. Phys. Rev. Lett. 133, 207203. Nov 15, 2024. 

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

Keywords: gst, chimera, self-assembly, waves, self-organized target wave chimera, asynchronous oscillators


sabato 2 novembre 2024

# gst: apropos of noise-assisted phenomena, self-organized transport in noisy dynamic networks.

AA << present a numerical study of multicommodity transport in a noisy, nonlinear network. The nonlinearity determines the dynamics of the edge capacities, which can be amplified or suppressed depending on the local current flowing across an edge. (AA) consider network self-organization for three different nonlinear functions: For all three (They) identify parameter regimes where noise leads to self-organization into more robust topologies, that are not found by the sole noiseless dynamics. Moreover, the interplay between noise and specific functional behavior of the nonlinearity gives rise to different features, such as (i) continuous or discontinuous responses to the demand strength and (ii) either single or multistable solutions. (AA) study shows the crucial role of the activation function on noise-assisted phenomena. >>️

Frederic Folz, Kurt Mehlhorn, Giovanna Morigi. Self-organized transport in noisy dynamic networks. Phys. Rev. E 110, 044310. Oct 21, 2024. 

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

Keywords: gst, network, noise, behavior, self-assembly, stability 


lunedì 14 ottobre 2024

# gst: apropos of fluctuations, an unconventional approach to (fuzzy) morphogenesis

AA << propose an unconventional mechanism where stochastic fluctuations drive the emergence of morphological patterns. >>️

In this approach << the inherent fluctuations determine the nature of the dynamics and are not incidental noise in the background of the otherwise deterministic dynamics. Instead, they play an important role as a driving force that defines the attributes of the pattern formation dynamics and the nature of the transition itself.  >>️

Oded Agam and Erez Braun. Fluctuation-driven morphological patterning: An unconventional approach to morphogenesis. Phys. Rev. Research 6, 043027. Oct 10, 2024.

Also: disorder & fluctuations, self-assembly, metamorphosis, transition, noise, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, disorder, fluctuations,  self-assembly, metamorphosis, transition, noise


martedì 23 gennaio 2024

# 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. 

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. 

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

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


giovedì 18 gennaio 2024

# 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.

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

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

martedì 12 settembre 2023

# gst: tuning of Janus particles under flows

<< Active colloidal systems with nonequilibrium self-organization constitute a long-standing, challenging area in material sciences and biology. To understand how hydrodynamic flow may be used to actively control self-assembly of Janus particles (JPs), (AA)  developed a model for the many-body hydrodynamics of amphiphilic JPs suspended in a viscous fluid with imposed far-field background flows. >>

They << alter the hydrophobic distribution on the JP-solvent interface to investigate the hydrodynamics that underlies the various morphologies and rheological properties of the JP assembly in the suspension. (They) find that JPs assemble into unilamellar, multilamellar, and striated structures. >>

AA << characterize the effective material properties of the JP structures and find that the unilamellar structure increases orientation order under shear flow, the multilamellar structure behaves as a shear thinning fluid, and the striated structure possesses a yield stress. >> ️

Szu-Pei Fu, Rolf Ryham, Bryan Quaife, and Y.-N. Young. Effects of tunable hydrophobicity on the collective hydrodynamics of Janus particles under flows. Phys. Rev. Fluids 8, 050501. May 11, 2023.


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

Keywords: particles, Janus, Janus particles, self-organization, self-assembly


venerdì 18 agosto 2023

# gst: emergence of self-organizing zigzag patterns among (magnetic) particles suspended in a liquid


<< When molecules or bacteria organize into a long-range pattern, researchers want to understand how the microscopic interactions lead to the macroscopic order. (AA) observed such self-organization in magnetic particles suspended in a liquid and subjected to an oscillating magnetic field. Through experiments and simulations, the team showed that the resulting zigzag pattern is explained by the fluid flow generated around the oscillating particles, not by any details of the particles or the applied field. Similar zigzag patterns have also been seen in charged colloids subjected to oscillating electric fields, so the explanation may cover a range of particle systems. The researchers also believe that understanding and controlling the effect could lead to useful applications in microfluidics devices. >>️

David Ehrenstein. Self-Organized Zigzags from Fluid Flow. Physics 16, 138. Aug 11, 2023.

Gaspard Junot, Marco De Corato, Pietro Tierno. Large Scale Zigzag Pattern Emerging from Circulating Active Shakers. Phys. Rev. Lett. 131, 068301. Aug 11, 2023. 

Also: particle, self-assembly, chiral, behav, in: https://www.inkgmr.net/kwrds.html  

Keywords: gst, behavior, particle, self-assembly, self-organization, chiral, active shakers, squirmers, alternating chirality


mercoledì 24 maggio 2023

# gst: intricate transitions in elastoactive structures.

<< The interplay between activity and elasticity often found in active and living systems triggers a plethora of autonomous behaviors ranging from self-assembly and collective motion to actuation. Among these, spontaneous self-oscillations of mechanical structures is perhaps the simplest and most widespread type of nonequilibrium phenomenon. >>️

<< Here, (AA) introduce a centimeter-sized model system for one-dimensional elastoactive structures. >>️

<< such structures exhibit flagellar motion when pinned at one end, self-snapping when pinned at two ends, and synchronization when coupled together with a sufficiently stiff link. (..) these transitions can be described quantitatively by simple models of coupled pendula with follower forces. >>️

Ellen Zheng, Martin Brandenbourger, et al. Self-Oscillation and Synchronization Transitions in Elastoactive Structures. Phys. Rev. Lett. 130, 178202. April 25, 2023. 

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

Keywords: gst, transition, particle, self-assembly, elastic, pendulum


lunedì 24 aprile 2023

# gst: emergent organization and polarization due to active fluctuations.


AA << introduce and study a model of active Brownian motion with multiplicative noise describing fluctuations in the self-propulsion or activity. (They) find that the standard picture of density accumulation in slow regions is qualitatively modified by active fluctuations, as stationary density profiles are generally not determined only by the mean self-propulsion speed landscape. As a result, activity gradients generically correlate the particle self-propulsion speed and orientation, leading to emergent polarization at interfaces pointing either towards dense or dilute regions depending on the amount of noise in the system.  >>
Benoit Mahault, Prakhar Godara, Ramin Golestanian. Emergent organization and polarization due to active fluctuations. Phys. Rev. Research 5, L022012. April 12, 2023. 

Also: 'particle', 'fluctuations', 'noise', 'self-assembly' in https://www.inkgmr.net/kwrds.html

Keywords: gst, particle, organization, polarization, fluctuations, noise, self-propulsion, self-assembly 



venerdì 7 aprile 2023

# gst: packing in slender structures, the geometry of squeezed elastic beams


<< The behavior of a collection of squeezed elastic beams is determined by geometry, not by complex forces. >>️

Dan Garisto. How Order Emerges in Bendy Beam Bunches. Physics 16, 54. Apr 3, 2023.

<< A collection of thin structures buckle, bend, and bump into each other when confined. This contact can lead to the formation of patterns: hair will self-organize in curls; DNA strands will layer into cell nuclei; paper, when crumpled, will fold in on itself, forming a maze of interleaved sheets. This pattern formation changes how densely the structures can pack, as well as the mechanical properties of the system. >>️

<< Here (AA) study the emergence of order in a canonical example of packing in slender structures, i.e., a system of parallel confined elastic beams. >>️

They << find that the compressive stiffness and stored bending energy of this metamaterial are directly proportional to the number of beams that are geometrically frustrated at any given point.  >>
Arman Guerra, Anja C. Slim, et al. Self-Ordering of Buckling, Bending, and Bumping Beams. Phys. Rev. Lett. 130, 148201. Apr 3, 2023.

Also

keyword 'self-assembly' in FonT

keyword 'elastic' in FonT

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

Keywords: gst, self-assembly, beams, buckling, bending, bumping, elasticity





sabato 21 gennaio 2023

# chem: spontaneous reconfiguration of deformable nanoparticles (in response to environmental cues)


<< Deformable nanoparticles (NPs) offer unprecedented opportunities as dynamic building blocks that can spontaneously reconfigure during assembly in response to environmental cues. >>

<< deformable spherical NPs of radius 50 nm whose surface is tailored with octahedrally distributed charged patches and double-cap charged patches adapt their shape differently in response to changes in surface charge coverage and ionic strength. >>

AA << find shape transitions to rounded octahedra, faceted octahedra, faceted bowls, oblate spheroids, spherocylinders, dented beans, and dimpled rounded bowls. >>

AA << demonstrate that similar shape transitions can be achieved in deformable NPs of different sizes. >>️

Fanbo Sun, Nicholas E. Brunk, Vikram Jadhao. Shape control of deformable charge-patterned nanoparticles. Phys. Rev. E 107, 014502. Jan 10, 2023.


Also

keyword 'self-assembly' in FonT


keyword 'nano' in FonT


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


Keywords: chem, nano, nanoparticles,  NPs, self-assembly, colloids, polymers, vesicle structures.


sabato 13 agosto 2022

# gst: how a synchronization could emerge from chaotic activities

<< Can we find order in chaos? Physicists have shown, for the first time that chaotic systems can synchronize due to stable structures that emerge from chaotic activity. These structures are known as fractals, shapes with patterns which repeat over and over again in different scales of the shape. As chaotic systems are being coupled, the fractal structures of the different systems will start to assimilate with each other, taking the same form, causing the systems to synchronize. >>️

<< If the systems are strongly coupled, the fractal structures of the two systems will eventually become identical, causing complete synchronization between the systems. These findings help us understand how synchronization and self-organization can emerge from systems that didn't have these properties to begin with, like chaotic systems and biological systems. >>️

Topological synchronization of chaotic systems. Bar-Ilan University. Apr 22, 2022. 

<< chaotic synchronization has a specific trait in various systems, from continuous systems and discrete maps to high dimensional systems: synchronization initiates from the sparse areas of the attractor, and it creates what (AA) termed as the ‘zipper effect’, a distinctive pattern in the multifractal structure of the system that reveals the microscopic buildup of the synchronization process. >>️

Lahav, N., Sendina-Nadal, I., et al. Topological synchronization of chaotic systems. Sci Rep 12, 2508. doi: 10.1038/ s41598-022-06262-z. Feb 15, 2022. 

Also

keyword 'self-assembly' in FonT


Keywords: gst, self-assembly, self-organization, fractals, topological synchronization, zipper effect, chaos, chaotic systems