# gst: apropos of transitions, the transition from sticking to slipping.

<< From hydrogels and plastics to liquid crystals, soft solids cover a wide array of synthetic and biological materials that play key enabling roles in advanced technologies >>️

<< Attempts to study the interactions between soft solids and liquids have largely focused on the wetting of soft solids and its resulting deformation at equilibrium or in a quasi-static state. Here, (AA) consider the frequently encountered case of unsteady wetting of a liquid on a soft solid and show that transient deformation of the solid is necessary to understand unsteady wetting behaviours. >>️

AA << find that the initial spreading of the liquid occurs uninterrupted in the absence of solid deformation. This is followed by intermittent spreading, in which transient deformation of the solid at the three-phase contact line (CL) causes the CL motion to alternate alternation between CL sticking and slipping. (They) identify the spreading rate of liquids and the viscoelastic reacting rate of soft solids as the two competing factors in dictating intermittent spreading. (They)  formulate and validate experimentally the conditions required for the contact line to transition from sticking to slipping. By considering the growing deformation of soft solids as dynamic surface heterogeneities, (AA) proposed conditions for stick-slip transition in unsteady wetting on soft solids broaden the classical theory on wetting hysteresis on rigid solids. >>️

Surjyasish Mitra, Quoc Vo, Marcus Lin, Tuan Tran. Unsteady wetting of soft solids. arXiv:2211.07043v1 [cond-mat.soft]. Nov 13, 2022.

https://arxiv.org/abs/2211.07043

Also

keyword 'drop' | 'droplet' | 'droploids' in FonT

https://flashontrack.blogspot.com/search?q=drop

https://flashontrack.blogspot.com/search?q=droplet

https://flashontrack.blogspot.com/search?q=droploids

keyword 'goccia' in Notes 

(quasi-stochastic poetry) 

https://inkpi.blogspot.com/search?q=goccia

Keywords: gst, behav, behaviour, transition, soft solids, drop, droplet, sticking, slipping.

# gst: when a soliton juggles ('catches' and 'throws') droplets

<< Jugglers normally work with solid objects, but a research team has now demonstrated a system that juggles liquid drops. (AA)  have previously shown that liquid drops can bounce in place above the surface of the same liquid—or bounce while moving across the surface—if the container is continuously vibrated (..) In these past experiments, the surface was nearly flat, except for waves generated by the bouncing drop. In the new work by undergraduate student Camila Sandivari of the University of Chile and her colleagues, the vibrations cause the liquid surface to form a large standing wave that actively “catches” and “throws” the drop during each cycle of its oscillation. The trapping of the drop is similar in principle to other types of wave traps, such as laser-based optical tweezers, and the system could potentially lead to new types of traps for larger objects. >>

AA << placed water mixed with a dye and a surface-tension-reducing agent in a 20-cm-long, 2.6-cm-wide basin that supports an unusual type of surface wave when the basin is vibrated in a specific frequency range. In this wave, rather than a series of oscillating peaks and valleys, there is only a single standing wave peak, called a soliton. However, this peak doesn’t oscillate uniformly across the basin’s short dimension (the width). A peak appears at one of the long walls coincident with a valley at the opposite wall, and then the peak and the valley switch places moments later, keeping a relatively flat “node” line along the central long axis of the basin. >>

AA << used a pipette to place a few-millimeter-wide drop of the same fluid just above the oscillating soliton, close to one of the long walls, and found that drops could be juggled for up to 90 minutes. The team attributes this unusual stability in part to a property of the soliton: if the drop wanders off-center, the oscillating surface wave pulls it back toward its center, similar to the way the laser field in optical tweezers is able to stably hold a small particle at its center. >>

David Ehrenstein. Juggling Water Drops. Physics 16, 21. Feb 10, 2023. 

https://physics.aps.org/articles/v16/21

Also

keyword 'drop' | 'droplet' | 'droploids' in FonT

https://flashontrack.blogspot.com/search?q=drop

https://flashontrack.blogspot.com/search?q=droplet

https://flashontrack.blogspot.com/search?q=droploids

keyword 'goccia' in Notes 

(quasi-stochastic poetry)

https://inkpi.blogspot.com/search?q=goccia

keyword 'solitons' in FonT

https://flashontrack.blogspot.com/search?q=soliton

https://flashontrack.blogspot.com/search?q=solitons

Keywords: gst, solitons, drop, droplet, droploids, goccia

# gst: ️apropos of spontaneous active matter, the active droploids.

<< Active matter comprises self-driven units, such as bacteria and synthetic microswimmers, that can spontaneously form complex patterns and assemble into functional microdevices. These processes are possible thanks to the out-of-equilibrium nature of active-matter systems, fueled by a one-way free-energy flow from the environment into the system. Here, (AA) take the next step in the evolution of active matter by realizing a two-way coupling between active particles and their environment, where active particles act back on the environment giving rise to the formation of superstructures. >>️

<< These structures hinge on mutually coupled structure formation processes of the colloids, which form an engine, and the surrounding solvent, which phase separates in regions of high colloidal density and encapsulates the engine within a droplet shell.  >>

️

Jens Grauer, Falko Schmidt, et al. Active droploids. arXiv:2109.10677v1 [cond-mat.soft]. Sep 22, 2021.

https://arxiv.org/abs/2109.10677

Also

keyword 'drop' | 'droplet' in FonT

https://flashontrack.blogspot.com/search?q=drop

https://flashontrack.blogspot.com/search?q=droplet

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

https://inkpi.blogspot.com/search?q=goccia

keywords: gst, drops, droplets, colloids, active matter, active droploids, self-assembly, solitons.

# gst: self-assembly in complex patterns during the evaporation of a sessile droplet

<< When a sessile droplet containing a solute in a volatile solvent evaporates, flow in the droplet can transport and assemble solute particles into complex patterns. >>

Bryan A. Nerger, P.-T. Brun, Celeste M. Nelson. Marangoni flows drive the alignment of fibrillar cell-laden hydrogels. Science Advances. Vol. 6, no. 24, eaaz7748. doi: 10.1126/ sciadv.aaz7748. Jun 12, 2020.

https://advances.sciencemag.org/content/6/24/eaaz7748   

Thamarasee Jeewandara. Marangoni flows drive the alignment of fibrillar cell-laden hydrogels. Phys.org. Jun 25, 2020

https://phys.org/news/2020-06-marangoni-alignment-fibrillar-cell-laden-hydrogels.html

Also

keyword 'Marangoni effect'

https://en.m.wikipedia.org/wiki/Marangoni_effect

http://web.mit.edu/2.21/www/Lec-notes/Surfacetension/Lecture4.pdf

# gst: when droplets are capable of self-propulsion as if they were surfing on a self-generated wave.

<< active droplets can move autonomously or oscillate between confining walls (..). Those behaviors could provide a clue about how life emerged from inanimate material. >>️

<< in the past decades, it has become clear that weak physical interactions among biomolecules are a crucial part of the answer. Such interactions allow some molecules to stay together transiently while avoiding others, which can lead to the spontaneous formation of droplets whose composition differs from their surroundings. Although biochemist Alexander Oparin suggested such ideas a century ago (..), experimental corroboration arrived only recently >>️

<< The key contribution of Demarchi and his collaborators is to demonstrate that droplet drift can enhance the heterogeneity of substrate and product. The resulting positive feedback allows droplets to move continuously as if they were surfing on a self-generated wave. >>️

David Zwicker. Droplets Come to Life. Physics 16, 45. Mar 20, 2023. 

https://physics.aps.org/articles/v16/45

AA << find that condensates move toward the center of a confining domain when this feedback is weak. Above a feedback threshold, they exhibit self-propulsion, leading to oscillatory dynamics. Moreover, catalysis-driven enzyme fluxes can lead to interrupted coarsening, resulting in equidistant condensate positioning, and to condensate division. >>

️

Leonardo Demarchi, Andriy Goychuk, et al. Enzyme-Enriched Condensates Show Self-Propulsion, Positioning, and Coexistence. Phys. Rev. Lett. 130, 128401. Mar 20, 2023.

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.130.128401

Also

'drop', 'droplet', 'droploid', 'transition' in 

https://www.inkgmr.net/kwrds.html

Keywords: gst, drop, droplet, waves, transition, liquid-liquid phase transition, nonequilibrium systems

# 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.

https://arxiv.org/abs/2201.07689

Also

keyword 'drop' | 'droplet' in FonT

https://flashontrack.blogspot.com/search?q=drop

https://flashontrack.blogspot.com/search?q=droplet

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

https://inkpi.blogspot.com/search?q=goccia

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

# gst: apropos of 1or2achoos (e.g. from Wuhan), the dynamics of turbulence in a fluid puff

<< Turbulence is everywhere -- in the movement of the wind, the ocean waves and even magnetic fields in space. It can also be seen in more transient phenomena, like smoke billowing from a chimney, or a cough. (..) Understanding this latter type of turbulence -- called puff turbulence -- is important not only for the advancement of fundamental science, but also for practical health and environmental measures, >>️

<< The very nature of turbulence is chaotic, so it's hard to predict, (..) Puff turbulence, which occurs when the ejection of a gas or liquid into the environment is disrupted, rather than continuous, has more complicated characteristics, so it's even more challenging to study. But it's of vital importance -- especially right now for understanding airborne transmission of viruses like SARS-CoV-2. >>️ Marco Edoardo Rosti. 

<< The new model, (..) includes how minute fluctuations within the puff behave, and how both large-scale and small-scale dynamics are impacted by changes in temperature and humidity. (..) at cooler temperatures (15°C or lower), (AA) model deviated from the classical model for turbulence. >>️

<< In the classical model, turbulence reigns supreme -- determining how all the little swirls and eddies within the flow behave. But once temperatures dipped, buoyancy started to have a greater impact. >>

<< The effect of buoyancy was initially very unexpected. It's a completely new addition to the theory of turbulent puffs,>> Marco Edoardo Rosti. ️

Secrets of COVID-19 transmission revealed in turbulent puffs. Okinawa Institute of Science and Technology (OIST). Aug 26, 2021. 

https://www.sciencedaily.com/releases/2021/08/210826111729.htm

Andrea Mazzino, Marco Edoardo Rosti. Unraveling the Secrets of Turbulence in a Fluid Puff. Phys. Rev. Lett. 127, 094501. Aug 25, 2021. 

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.127.094501

Also

keyword 'drop' | 'droplet' in FonT:

https://flashontrack.blogspot.com/search?q=drop

https://flashontrack.blogspot.com/search?q=droplet

keyword 'turbulence' in FonT:

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keyword 'turbolento' | 'turbolenza' in Notes (quasi-stochastic poetry): 

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https://inkpi.blogspot.com/search?q=turbolenza

keyword 'virus' | 'sars-cov-2' | 'sars' in FonT: 

https://flashontrack.blogspot.com/search?q=virus

https://flashontrack.blogspot.com/search?q=sars-cov-2

https://flashontrack.blogspot.com/search?q=sars

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

https://inkpi.blogspot.com/search?q=virus

# gst: a striking analogy between solid–solid and solid–drop frictions

AA << report that the lateral adhesion force between a liquid drop and a solid can also be divided into a static and a kinetic regime. This striking analogy with solid–solid friction is a generic phenomenon that holds for liquids of different polarities and surface tensions on smooth, rough and structured surfaces >>

Nan Gao, Florian Geyer, et al. How drops start sliding over solid surfaces. Nature Physics doi: 10.1038/nphys4305 Nov 6, 2017

https://www.nature.com/articles/nphys4305

AA << acknowledges that their experiments are just the beginning in trying to fully understand the nature of friction between drops and solid objects >>

Bob Yirka. Droplet friction found to be similar to that of solid objects. Nov 8, 2017

https://m.phys.org/news/2017-11-droplet-friction-similar-solid.html

# gst: multi-component droplets may exhibit self-lubricating effects

<< Over the past decade, there has been a growing interest in the study of multicomponent drops. These drops exhibit unique phenomena, as the interplay between hydrodynamics and the evolving physicochemical properties of the mixture gives rise to distinct and often unregulated behaviors. >>

<< Of particular interest is the complex dynamic behavior of the drop contact line, which can display self-lubrication effect. The presence of a slipping contact line in self-lubricating multicomponent drops can suppress the coffee-stain effect, conferring valuable technological applications. >>

Huanshu Tan, Detlef Lohse, Xuehua Zhang. Self-Lubricating Drops. arXiv: 2403.01207v1 [physics.flu-dyn]. Mar 2, 2024

https://arxiv.org/abs/2403.01207

Also: drop droplet droploid, in https://www.inkgmr.net/kwrds.html

Keywords: drop, droplet, droploid, multicomponent drops, drop contact line, self-lubrication

# gst: exploring the lifespan of a liquid droplet

<< Current theories state that the droplet's diameter-squared decreases in proportion to time (classical law); however, this period only accounts for a small portion of the drop's evolution. As the diameter approaches the unobservable micro- and nano-scale, molecular dynamics have to be used as virtual experiments and these show a crossover to a new behaviour, with the diameter now reducing in proportion to time (nano-scale law). >>

<< It is fascinating that intuition based on everyday observations are a hindrance when attempting to understand nanoscale flows, so that, as in this research, one has to lean on theory to enlighten us. >>  James Sprittles.

The lifespan of an evaporating liquid drop. University of Warwick. Oct 10, 2019.     https://m.phys.org/news/2019-10-lifespan-evaporating-liquid.html

Rana A.S., Lockerby D.A., Sprittles J.E.  Lifetime of a Nanodroplet: Kinetic Effects and Regime Transitions. Phys. Rev. Lett. 123, 154501 Oct 9, 2019.     https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.123.154501   

# s-gst: surface waves as a Turing machine

<< A droplet bouncing and wandering across a liquid surface can produce waves that store the history of its chaotic motion >>

Philip  Ball. Focus:  Surface  Waves  Store  Bouncing Droplet’s  History. Physics  9,  101. August  26,  2016.

http://physics.aps.org/articles/v9/101

S. Perrard, E. Fort, Y. Couder. Wave-Based Turing Machine: Time Reversal and Information Erasing. Phys. Rev. Lett. 117, 094502 – DOI: 10.1103/PhysRevLett.117.094502 Published 26 August 2016

http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.117.094502

# chem: how to quickly wrap droplets with a splash to stabilize emulsions

<< Whether an object has a regular or irregular shape, wrapping it with a thin film can be challenging >>

Deepak Kumar, Joseph D. Paulsen, et al.  Wrapping with a splash: High-speed encapsulation with ultrathin sheets. Science. 2018; 359 (6377): 775 - 8. doi: 10.1126/science.aao1290. Feb 16, 2018.

http://science.sciencemag.org/content/359/6377/775

<< The quick and simple solution Kumar [Deepak Kumar] has found is a huge advance, and once he mastered it and identified the most important parameters, he found he could get adventurous and make different shapes. "We show that we have made cubes and a tetrahedron, for example" >>

<< If you want to add complexity, you could put a layer or a pattern on the inside of the wrapping, or you could add a window to make it slightly leaky. Once you know how to do the technique, it's not fussy. >>

University of Massachusetts Amherst. Physicists speed up droplet-wrapping process. Feb 15, 2018.

https://m.phys.org/news/2018-02-physicists-droplet-wrapping.html

# life: aprops of 1or2 achoo! from Wuhan (SARS-CoV-2), a mask build of 'nanofibers randomly land on a collector to create a sort of non-woven mesh'

<< Recently, students from BYU’s College of Engineering teamed up with Nanos Foundation to develop a nanofiber membrane that can be sandwiched between the cloth pieces in a homemade mask. While today’s typical cloth mask might block fewer than 50% of virus particles, the membrane — which can be made using simple, inexpensive materials — will be able to block 90 to 99% of particles, increasing effectiveness while preserving breathability. The membranes are made through a process called “electrospinning,” which involves dissolving a polymer plastic in a solution and then using an electrical current to move a droplet of the polymer downward through a needle. As the droplet accelerates, it stretches into a very small fiber that retains a static charge. >>

<< Those nanofibers randomly land on a collector to create a sort of non-woven mesh, >> Katie Varela.

Christie Allen. With innovative nanofiber membranes, cloth masks’  efficacy goes up to 99%. Oct 21, 2020.

https://news.byu.edu/intellect/with-new-byu-created-nanofiber-membranes-cloth-masks-efficacy-goes-up-to-99 

https://phys.org/news/2020-10-nanofiber-membranes-masks-efficacy.html   

Also

keyword 'virus' in FonT: 

https://flashontrack.blogspot.com/search?q=virus

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

https://inkpi.blogspot.com/search?q=virus

# gst: apropos of 'transitions', slow dynamics of complex connected networks can control the rate of demixing

<< A space- spanning network structure is a basic morphology in phase separation of soft and biomatter, alongside a droplet one. Despite its fundamental and industrial importance, the physical principle underlying such network- forming phase separation remains elusive. >>

AA << find that phase- separation dynamics is controlled by mechanical relaxation of the network- forming dense phase, whose limiting process is permeation flow of the solvent for colloidal suspensions and heat transport for pure fluids. This universal coarsening law would contribute to the fundamental physical understanding of network-forming phase separation. >>

Michio Tateno, Hajime Tanaka. Power-law coarsening in network-forming phase separation governed by mechanical relaxation. Nat Commun 12, 912. doi: 10.1038/  s41467-020-20734-8. Feb 10,  2021.

https://www.nature.com/articles/s41467-020-20734-8

️

Discovery of a new law of phase separation. University of Tokyo. Feb 10, 2021. 

https://phys.org/news/2021-02-discovery-law-phase.html

Also

keyword 'transition' in FonT

https://flashontrack.blogspot.com/search?q=transition

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

https://inkpi.blogspot.com/search?q=transition

https://inkpi.blogspot.com/search?q=transizione

https://inkpi.blogspot.com/search?q=transizioni

# gst: apropos of transitions, two aspects of intermittency

<< intermittency produces significant probability of rare events that may locally accelerate the collision rates by a large factor in comparison with estimates using typical events. >>

<< Increasing intermittency of turbulence destroys the theory not via stronger bursts, but rather via increase of characteristic sizes of regions of calm and quiescent flow. ([AA️] remind that these two aspects of intermittency go together: increase of regions of calm flow and at the same time increased probability of strong bursts ([8] U. Frisch, Turbulence: The Legacy of A. N. Kolmogorov, (Cambridge University Press, New York, 1995).). >>

Itzhak Fouxon, Seulgi Lee, Changhoon Lee. Intermittency and collisions of fast sedimenting droplets in turbulence.  arXiv:2205.06972v1 [physics.flu-dyn]. May 14, 2022. 

https://arxiv.org/abs/2205.06972

Also

keyword 'intermittency' in FonT

https://flashontrack.blogspot.com/search?q=intermittency

keyword 'intermittenza|e' | 'intermittente|i' in Notes (quasi-stochastic poetry)

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https://inkpi.blogspot.com/search?q=intermittenze

https://inkpi.blogspot.com/search?q=intermittente

https://inkpi.blogspot.com/search?q=intermittenti

Keywords: gst, intermittency, collision, drop, droplet, turbulence

# gst: contactless manipulation of droplets levitating in an acoustic wave

<< A unique, versatile, and material-independent approach to manipulate contactlessly and merge two chemically distinct droplets suspended in an acoustic levitator is reported. Large-amplitude axial oscillations are induced in the top droplet by low-frequency amplitude modulation of the ultrasonic carrier wave, which causes the top sample to merge with the sample in the pressure minimum below. The levitator is enclosed within a pressure-compatible process chamber to enable control of the environmental conditions. The merging technique permits precise control of the substances affecting the chemical reactions, the sample temperature, the volumes of the liquid reactants down to the picoliter range, and the mixing locations in space and time. >>

Stephen J. Brotton, Ralf I. Kaiser. 

Controlled Chemistry via Contactless Manipulation and Merging of Droplets in an Acoustic Levitator. Anal. Chem. 2020, 92, 12, 8371–8377. doi: 10.1021/ acs.analchem.0c00929. Jun 1, 2020. 

https://pubs.acs.org/doi/10.1021/acs.analchem.0c00929#

Levitating droplets allow scientists to perform 'touchless' chemical reactions.  American Chemical Society. Jun 24, 2020.

https://phys.org/news/2020-06-levitating-droplets-scientists-touchless-chemical.html  

# gst: apropos of transitions, perspectives on viscoelastic flow instabilities; the 'porous individualism'

<< given the observation that disorder can suppress the transition to elastic turbulence in 2D porous media (..), it has been unclear whether and how this transition manifests in disordered 3D media — though elastic turbulence has been speculated to underlie the long-standing observation that the macroscopic flow resistance of an injected polymer solution can abruptly increase above a threshold flow rate in a porous medium, but not in bulk solution >>️

AA << found that the transition to unstable flow in each pore is continuous, arising due to the increased persistence of discrete bursts of instability above a critical value of the characteristic (Weissenberg no.) Wi; however, the onset value varies from pore to pore. This observation that single pores exposed to the same macroscopic flow rate become unstable in different ways provides a fascinating pore-scale analog of “molecular individualism” [P.  De Gennes, Molecular individualism. Science 276, 1999–2000 (1997)], in which single polymers exposed to the same extensional flow elongate in different ways; the authors therefore termed it “porous individualism”, although it is important to note that here, this effect is still at the continuum (not molecular) scale. Thus, unstable flow is spatially heterogeneous across the different pores of the medium, with unstable and laminar regions coexisting >>

AA << quantitatively established that the energy dissipated by unstable pore-scale fluctuations generates an anomalous increase in flow resistance through the entire medium that agrees well with macroscopic pressure drop measurements. >>

Sujit S. Datta, Arezoo M. Ardekani, et al. Perspectives on viscoelastic flow instabilities and elastic turbulence. arXiv: 2108.09841v1 [physics.flu-dyn]. Aug 22, 2021. 

https://arxiv.org/abs/2108.09841

Also

keyword 'transition' | 'transitional' in FonT

https://flashontrack.blogspot.com/search?q=transition

https://flashontrack.blogspot.com/search?q=transitional

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

https://inkpi.blogspot.com/search?q=transition

https://inkpi.blogspot.com/search?q=transizione

https://inkpi.blogspot.com/search?q=transizioni

keywords: gst, droplet, fluctuations, disorder, instability, viscoelastic flow instability, turbulence, elastic turbulence, individualism, porous individualism, transition

# gst: apropos of evaporation, puncturing of active drops

<< By virtue of self-propulsion, active particles impart intricate stresses to the background fluids. (..) this active stress can be utilized to greatly control evaporation dynamics of active drops. >>

AA << discover a new phenomenon of puncturing of the active drops, where the air-liquid interface of the drop undergoes spontaneous tearing and there occurs a formation of a new three-phase contact line due to the liquid-air interface hitting the liquid-solid interface through evaporation-driven mass loss. Post puncturing, (AA) see an inside-out evaporation of the drop, where the new contact line sweeps towards the pinned outer contact line of the drops, contrasting regular drops that straightaway shrink to zero volume with self-similar shape. >>

<< Furthermore, (..) the activity inside the drops can manipulate the three-phase contact-line dynamics, which for contractile drops can result in an up to 50% enhanced lifetime of the drop and 33% quicker evaporation for extensile drops. By analyzing the flux distribution inside the drop, (AA) gain insights on nonintuitive deposition patterns (e.g., ring galaxy type deposits that demonstrate controllable spatial gradients in the concentrations of the deposited particles) of active particles, which are oftentimes biological substances or bimetallic nanoparticles of interest. >>

Ghansham Rajendrasingh Chandel, Vishal Sankar Sivasankar, Siddhartha Das. Evaporation of active drops: Puncturing drops and particle deposits of ring galaxy patterns. Phys. Rev. Fluids 9, 033603. Mar 27, 2024. 

https://journals.aps.org/prfluids/abstract/10.1103/PhysRevFluids.9.033603

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

Keywords: gst, drop, particle, evaporation, transition, drop interactions, droplet, droploid

# gst: the auto assembly of a drop (from thermal capillary waves)

<< after single or multiple bridges form due to the presence of thermal capillary waves, the bridge growth commences in a thermal regime. Here, the bridges expand linearly in time much faster than the viscous-capillary speed due to collective molecular jumps near the bridge fronts. Transition to the classical hydrodynamic regime only occurs once the bridge radius exceeds a thermal length scale l_(T) ~ sqrt(Radius). >>

Sreehari Perumanath, Matthew K. Borg, et al. Droplet Coalescence is Initiated by Thermal Motion. Phys. Rev. Lett. 122, 104501 Mar 13, 2019.

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.122.104501

Supercomputer sheds light on how droplets merge. University of Edinburgh. Mar 20, 2019.

https://m.phys.org/news/2019-03-supercomputer-droplets-merge.html

# GST: how to harvest energy from impacting droplets

AA << designed an electrical generator that can harvest energy from impacting droplets and other sources of mechanical energy. (..) The electrical generator can be explained as being a permanently charged capacitor, also known as an electret. >>

They << managed to convert 11.8% of the mechanical energy of an impacting droplet into electrical energy, which is a significant improvement compared to the efficiency of similar devices. Furthermore, they demonstrated that the energy harvesting efficiency does not degrade after 100 days, requiring only a single 15 minute charging cycle before long-term application. >>

K.W. Wesselink. Generator developed for harvesting energy from droplets. 

University of Twente. Jul 8, 2020.

https://phys.org/news/2020-07-harvesting-energy-droplets.html

Hao Wu, Niels Mendel, et al. Charge Trapping‐Based Electricity Generator (CTEG): An Ultrarobust and High Efficiency Nanogenerator for Energy Harvesting from Water Droplets. Advanced Materials. doi: 10.1002/ adma.202001699. July 6, 2020.

https://onlinelibrary.wiley.com/doi/full/10.1002/adma.202001699  

Hao Wu, Niels Mendel, et al. Energy harvesting from drops impacting onto charged surfaces. Phys. Rev. Lett. Jun 25, 2020.

https://journals.aps.org/prl/accepted/ec07bYb0D261277cc08a6414c57b4ce4ab3e8da4f

Also

keyword 'drops' in Font:

https://flashontrack.blogspot.com/search?q=drops