scholarly journals Clustering and self-organization in small-scale natural and artificial systems

2020 ◽  
Vol 378 (2167) ◽  
pp. 20190443 ◽  
Author(s):  
Edward Bormashenko ◽  
Alexander A. Fedorets ◽  
Mark Frenkel ◽  
Leonid A. Dombrovsky ◽  
Michael Nosonovsky
Keyword(s):  
Self Assembly ◽  
Small Scale ◽  
Theme Issue ◽  
Coupled Clusters ◽  
Strongly Coupled ◽  
Multi Scale ◽  
Physical Mechanisms ◽  
Capillary Interactions ◽  
The Hierarchical Structure ◽  
Number Of Particles

Physical properties of clusters, i.e. systems composed of a ‘small’ number of particles, are qualitatively different from those of infinite systems. The general approach to the problem of clustering is suggested. Clusters, as they are seen in the graphs theory, are discussed. Various physical mechanisms of clustering are reviewed. Dimensional properties of clusters are addressed. The dimensionality of clusters governs to a great extent their properties. Weakly and strongly coupled clusters are discussed. Hydrodynamic and capillary interactions giving rise to clusters formation are surveyed. Levitating droplet clusters, turbulent clusters and droplet clusters responsible for the breath-figures self-assembly are considered. Entropy factors influencing clustering are considered. Clustering in biological systems results in non-equilibrium multi-scale assembly, where at each scale, self-driven components come together by consuming energy in order to form the hierarchical structure. This article is part of the theme issue ‘Bioinspired materials and surfaces for green science and technology (part 3)’.

Current understanding of mesospheric transport processes

1987 ◽  
Vol 323 (1575) ◽  
pp. 655-666 ◽  
Keyword(s):  
Gravity Waves ◽  
Chemical Constituents ◽  
Transport Processes ◽  
Small Scale ◽  
Dynamical Structure ◽  
Strongly Coupled ◽  
Physical Mechanisms ◽  
Waves And Tides ◽  
The Subject ◽  
And Diffusion

The chemistry and transport processes taking place in the mesosphere (approximately 50—85 km altitude) are strongly coupled. In recent years, the physical mechanisms influencing the transport processes of the mesosphere have become better understood, through both theoretical and observational studies. Perhaps most importantly, a theoretical framework for describing the momentum deposition and diffusion due to breaking small-scale gravity waves has been developed and shown to result in thermal, chemical and dynamical structure that closely resembles observations. The transport due to planetary waves and tides has also been the subject of study. In this paper, the transport processes influencing mesospheric distributions of chemical constituents are briefly reviewed.

scholarly journals Multi-Scale Ionospheric Anomalies Monitoring and Spatio-Temporal Analysis during Intense Storm

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 215
Author(s):  
Na Cheng ◽  
Shuli Song ◽  
Wei Li
Keyword(s):  
Magnetic Storm ◽  
Large Scale ◽  
Temporal Dynamics ◽  
Ionospheric Disturbance ◽  
Ionospheric Scintillation ◽  
Small Scale ◽  
Electron Content ◽  
Total Electron ◽  
Multi Scale ◽  
Intense Storm

The ionosphere is a significant component of the geospace environment. Storm-induced ionospheric anomalies severely affect the performance of Global Navigation Satellite System (GNSS) Positioning, Navigation, and Timing (PNT) and human space activities, e.g., the Earth observation, deep space exploration, and space weather monitoring and prediction. In this study, we present and discuss the multi-scale ionospheric anomalies monitoring over China using the GNSS observations from the Crustal Movement Observation Network of China (CMONOC) during the 2015 St. Patrick’s Day storm. Total Electron Content (TEC), Ionospheric Electron Density (IED), and the ionospheric disturbance index are used to monitor the storm-induced ionospheric anomalies. This study finally reveals the occurrence of the large-scale ionospheric storms and small-scale ionospheric scintillation during the storm. The results show that this magnetic storm was accompanied by a positive phase and a negative phase ionospheric storm. At the beginning of the main phase of the magnetic storm, both TEC and IED were significantly enhanced. There was long-duration depletion in the topside ionospheric TEC during the recovery phase of the storm. This study also reveals the response and variations in regional ionosphere scintillation. The Rate of the TEC Index (ROTI) was exploited to investigate the ionospheric scintillation and compared with the temporal dynamics of vertical TEC. The analysis of the ROTI proved these storm-induced TEC depletions, which suppressed the occurrence of the ionospheric scintillation. To improve the spatial resolution for ionospheric anomalies monitoring, the regional Three-Dimensional (3D) ionospheric model is reconstructed by the Computerized Ionospheric Tomography (CIT) technique. The spatial-temporal dynamics of ionospheric anomalies during the severe geomagnetic storm was reflected in detail. The IED varied with latitude and altitude dramatically; the maximum IED decreased, and the area where IEDs were maximum moved southward.

scholarly journals Self-Assembly of Microscale Parts through Magnetic and Capillary Interactions

Micromachines ◽  
2011 ◽  
Vol 2 (1) ◽  
pp. 69-81 ◽  
Author(s):  
Christopher J. Morris ◽  
Brian Isaacson ◽  
Michael D. Grapes ◽  
Madan Dubey
Keyword(s):  
Self Assembly ◽  
Capillary Interactions

scholarly journals Dynamic simulations of many-body electrostatic self-assembly

2018 ◽  
Vol 376 (2115) ◽  
pp. 20170143 ◽  
Author(s):  
Eric B. Lindgren ◽  
Benjamin Stamm ◽  
Yvon Maday ◽  
Elena Besley ◽  
A. J. Stace
Keyword(s):  
Self Assembly ◽  
Experimental Studies ◽  
Charged Particles ◽  
Theoretical Chemistry ◽  
Many Body ◽  
Single Particles ◽  
Theme Issue ◽  
Dynamic Simulations ◽  
The Subject ◽  
Small Clusters

Two experimental studies relating to electrostatic self-assembly have been the subject of dynamic computer simulations, where the consequences of changing the charge and the dielectric constant of the materials concerned have been explored. One series of calculations relates to experiments on the assembly of polymer particles that have been subjected to tribocharging and the simulations successfully reproduce many of the observed patterns of behaviour. A second study explores events observed following collisions between single particles and small clusters composed of charged particles derived from a metal oxide composite. As before, observations recorded during the course of the experiments are reproduced by the calculations. One study in particular reveals how particle polarizability can influence the assembly process. This article is part of the theme issue ‘Modern theoretical chemistry’.

scholarly journals Extensive deep neural networks for transferring small scale learning to large scale systems

2019 ◽  
Vol 10 (15) ◽  
pp. 4129-4140 ◽  
Author(s):  
Kyle Mills ◽  
Kevin Ryczko ◽  
Iryna Luchak ◽  
Adam Domurad ◽  
Chris Beeler ◽  
...  
Keyword(s):  
Neural Network ◽  
Neural Networks ◽  
Large Scale ◽  
Deep Neural Network ◽  
Deep Neural Networks ◽  
Small Scale ◽  
Large Scale Systems ◽  
Energy Entropy ◽  
Large Systems ◽  
Number Of Particles

We present a physically-motivated topology of a deep neural network that can efficiently infer extensive parameters (such as energy, entropy, or number of particles) of arbitrarily large systems, doing so with scaling.

scholarly journals Rules of collective migration: from the wildebeest to the neural crest

2020 ◽  
Vol 375 (1807) ◽  
pp. 20190387 ◽  
Author(s):  
Adam Shellard ◽  
Roberto Mayor
Keyword(s):  
Neural Crest ◽  
Individual Cell ◽  
Embryonic Stem ◽  
Stem Cell Population ◽  
Scale Analysis ◽  
Collective Migration ◽  
Theme Issue ◽  
Cell Behaviour ◽  
Multi Scale ◽  
Universal Principles

Collective migration, the movement of groups in which individuals affect the behaviour of one another, occurs at practically every scale, from bacteria up to whole species' populations. Universal principles of collective movement can be applied at all levels. In this review, we will describe the rules governing collective motility, with a specific focus on the neural crest, an embryonic stem cell population that undergoes extensive collective migration during development. We will discuss how the underlying principles of individual cell behaviour, and those that emerge from a supracellular scale, can explain collective migration. This article is part of the theme issue ‘Multi-scale analysis and modelling of collective migration in biological systems’.

scholarly journals Preparation and properties of plasmonic-excitonic nanoparticle assemblies

Nanophotonics ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 517-547 ◽  
Author(s):  
Brian Szychowski ◽  
Matthew Pelton ◽  
Marie-Christine Daniel
Keyword(s):  
Good Control ◽  
Inorganic Nanoparticles ◽  
Rabi Splitting ◽  
Strongly Coupled ◽  
Nanoparticle Assemblies ◽  
Wide Range ◽  
Fano Interference ◽  
Potential Applications ◽  
The Individual ◽  
Number Of Particles

AbstractThe assembly of inorganic nanoparticles often leads to collective properties that are different from the combined properties of the individual components. In particular, coupling plasmonic and excitonic nanoparticles has been shown to modify their optical properties, including absorption, emission, and scattering. Because of this, these coupled assemblies have potential applications in a wide range of areas, including sensing, light harvesting, and photocatalysis. More recently, unique properties, including Fano interference and Rabi splitting, have been observed by increasing the coupling strength. However, the behavior of coupled nanoparticles is highly dependent on the exact organization of the components, including the number of particles coupled, the distance separating them, and their spatial orientation. This is especially true in the case of strongly coupled particles. Because of this, it is important to achieve synthetic techniques that not only can link particles together but also offer good control over how the particles are connected. In this review, assemblies of plasmonic and excitonic nanoparticles are reviewed, including the various methods that have been used for their construction, the properties that these systems have been predicted to possess as well as the ones that have been observed, and their current applications along with current challenges in the field and potential future applications.

scholarly journals Kinetic Control of Parallel versus Antiparallel Amyloid Aggregation via Shape of the Growing Aggregate

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ali Asghar Hakami Zanjani ◽  
Nicholas P. Reynolds ◽  
Afang Zhang ◽  
Tanja Schilling ◽  
Raffaele Mezzenga ◽  
...  
Keyword(s):  
Self Assembly ◽  
Small Scale ◽  
Kinetic Control ◽  
Amyloid Aggregation ◽  
X Ray Diffraction ◽  
Human Lysozyme ◽  
X Ray ◽  
Contact Topology ◽  
Future Design ◽  
Assembly Pathways

Abstract By combining atomistic and higher-level modelling with solution X-ray diffraction we analyse self-assembly pathways for the IFQINS hexapeptide, a bio-relevant amyloid former derived from human lysozyme. We verify that (at least) two metastable polymorphic structures exist for this system which are substantially different at the atomistic scale, and compare the conditions under which they are kinetically accessible. We further examine the higher-level polymorphism for these systems at the nanometre to micrometre scales, which is manifested in kinetic differences and in shape differences between structures instead of or as well as differences in the small-scale contact topology. Any future design of structure based inhibitors of the IFQINS steric zipper, or of close homologues such as TFQINS which are likely to have similar structures, should take account of this polymorphic assembly.

scholarly journals Flow-Induced Self-Assembly of Spider Silk from Multi-Scale Simulations

2020 ◽  
Vol 118 (3) ◽  
pp. 479a
Author(s):  
Ana M. Herrera ◽  
Anil Kumar Dasanna ◽  
Ulrich S. Schwarz ◽  
Frauke Gräter
Keyword(s):  
Self Assembly ◽  
Spider Silk ◽  
Multi Scale
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