Interaction Strength of DIL Systems

Porous pavements infiltrated with stormwater are faced with clogging problems: runoff particles seep and clog the pervious surface layer of these structures. Clogging material samples (in the form of sludge) have been collected in cleaning operations on the pervious asphalt. This study aims at characterizing these materials, particle size distribution, heavy metal contents by particle size, and studying interactions between metals and particles. A sequential extraction procedure proposed by the experts of the Community Bureau of Reference (B.C.R.) was applied to provide information about heavy metal distribution on particles and to evaluate interaction strength, and consequently potential metal mobility when chemical variations occurred in the environment. Mainly made up of sand, the materials are polluted with lead, copper, zinc and cadmium. The concentrations appeared to be linked with road traffic intensity. The heavy metal contents by particle size showed that the finer are the particles, the higher are the heavy metal concentrations. Heavy metals were found potentially labile; metals contents in the residual fraction (mineral fraction) represented less than 20 % of the total concentration. Cadmium and zinc were apparently more labile than lead and copper.

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Dynamics of the Creation of a Rotating Bose–Einstein Condensation by Two Photon Raman Transition Using a Laguerre–Gaussian Laser Pulse

Atoms ◽

10.3390/atoms9010014 ◽

2021 ◽

Vol 9 (1) ◽

pp. 14

Author(s):

Koushik Mukherjee ◽

Soumik Bandyopadhyay ◽

Dilip Angom ◽

Andrew M. Martin ◽

Sonjoy Majumder

Keyword(s):

Interaction Strength ◽

Transition Process ◽

Laser Pulses ◽

Harmonic Trap ◽

Einstein Condensation ◽

Raman Transition ◽

Two Photon ◽

Final Population ◽

The Creation ◽

Bose Einstein

We present numerical simulations to unravel the dynamics associated with the creation of a vortex in a Bose–Einstein condensate (BEC), from another nonrotating BEC using two-photon Raman transition with Gaussian (G) and Laguerre–Gaussian (LG) laser pulses. In particular, we consider BEC of Rb atoms at their hyperfine ground states confined in a quasi two dimensional harmonic trap. Optical dipole potentials created by G and LG laser pulses modify the harmonic trap in such a way that density patterns of the condensates during the Raman transition process depend on the sign of the generated vortex. We investigate the role played by the Raman coupling parameter manifested through dimensionless peak Rabi frequency and intercomponent interaction on the dynamics during the population transfer process and on the final population of the rotating condensate. During the Raman transition process, the two BECs tend to have larger overlap with each other for stronger intercomponent interaction strength.

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Swarm shedding in networks of self-propelled agents

Scientific Reports ◽

10.1038/s41598-021-92748-1 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Jason Hindes ◽

Victoria Edwards ◽

Klimka Szwaykowska Kasraie ◽

George Stantchev ◽

Ira B. Schwartz

Keyword(s):

Network Topology ◽

Collective Motion ◽

Mean Field Theory ◽

Mean Field ◽

Interaction Strength ◽

Central Question ◽

Agent Interaction ◽

Sparse Networks ◽

Swarm Pattern ◽

Limited Sensing

AbstractUnderstanding swarm pattern formation is of great interest because it occurs naturally in many physical and biological systems, and has artificial applications in robotics. In both natural and engineered swarms, agent communication is typically local and sparse. This is because, over a limited sensing or communication range, the number of interactions an agent has is much smaller than the total possible number. A central question for self-organizing swarms interacting through sparse networks is whether or not collective motion states can emerge where all agents have coherent and stable dynamics. In this work we introduce the phenomenon of swarm shedding in which weakly-connected agents are ejected from stable milling patterns in self-propelled swarming networks with finite-range interactions. We show that swarm shedding can be localized around a few agents, or delocalized, and entail a simultaneous ejection of all agents in a network. Despite the complexity of milling motion in complex networks, we successfully build mean-field theory that accurately predicts both milling state dynamics and shedding transitions. The latter are described in terms of saddle-node bifurcations that depend on the range of communication, the inter-agent interaction strength, and the network topology.

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Polyelectrolyte Gels: A Unique Class of Soft Materials

Gels ◽

10.3390/gels7030102 ◽

2021 ◽

Vol 7 (3) ◽

pp. 102

Author(s):

Ferenc Horkay

Keyword(s):

Exchange Process ◽

Interaction Strength ◽

Soft Materials ◽

Industrial Applications ◽

Future Research ◽

Swelling Kinetics ◽

Polyelectrolyte Gels ◽

Ion Exchange Process ◽

Counter Ions ◽

Kinetics Of

The objective of this article is to introduce the readers to the field of polyelectrolyte gels. These materials are common in living systems and have great importance in many biomedical and industrial applications. In the first part of this paper, we briefly review some characteristic properties of polymer gels with an emphasis on the unique features of this type of soft material. Unsolved problems and possible future research directions are highlighted. In the second part, we focus on the typical behavior of polyelectrolyte gels. Many biological materials (e.g., tissues) are charged (mainly anionic) polyelectrolyte gels. Examples are shown to illustrate the effect of counter-ions on the osmotic swelling behavior and the kinetics of the swelling of model polyelectrolyte gels. These systems exhibit a volume transition as the concentration of higher valence counter-ions is gradually increased in the equilibrium bath. A hierarchy is established in the interaction strength between the cations and charged polymer molecules according to the chemical group to which the ions belong. The swelling kinetics of sodium polyacrylate hydrogels is investigated in NaCl solutions and in solutions containing both NaCl and CaCl2. In the presence of higher valence counter-ions, the swelling/shrinking behavior of these gels is governed by the diffusion of free ions in the swollen network, the ion exchange process and the coexistence of swollen and collapsed states.

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Surface Chemistry, Crystal Structure, Size and Topography Role in the Albumin Adsorption Process on TiO2 Anatase Crystallographic Faces and Its 3D-Nanocrystal: A Molecular Dynamics Study

Coatings ◽

10.3390/coatings11040420 ◽

2021 ◽

Vol 11 (4) ◽

pp. 420

Author(s):

Giuseppina Raffaini

Keyword(s):

Crystal Structure ◽

Molecular Dynamics ◽

Surface Chemistry ◽

Protein Adsorption ◽

Adsorption Process ◽

Sol Gel ◽

Interaction Strength ◽

Theoretical Work ◽

Blood Protein ◽

Tio2 Anatase

TiO2 is widely used in biomaterial implants. The topography, chemical and structural properties of titania surfaces are an important aspect to study. The size of TiO2 nanoparticles synthetized by sol–gel method can influence the responses in the biological environment, and by using appropriate heat treatments different contents of different polymorphs can be formed. Protein adsorption is a crucial step for the biological responses, involving, in particular, albumin, the most abundant blood protein. In this theoretical work, using molecular mechanics and molecular dynamics methods, the adsorption process of an albumin subdomain is reported both onto specific different crystallographic faces of TiO2 anatase and also on its ideal three-dimensional nanosized crystal, using the simulation protocol proposed in my previous theoretical studies about the adsorption process on hydrophobic ordered graphene-like or hydrophilic amorphous polymeric surfaces. The different surface chemistry of anatase crystalline faces and the nanocrystal topography influence the adsorption process, in particular the interaction strength and protein fragment conformation, then its biological activity. This theoretical study can be a useful tool to better understand how the surface chemistry, crystal structure, size and topography play a key role in protein adsorption process onto anatase surface so widely used as biomaterial.

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Spin-ice physics in cadmium cyanide

Nature Communications ◽

10.1038/s41467-021-22515-3 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Chloe S. Coates ◽

Mia Baise ◽

Adrian Schmutzler ◽

Arkadiy Simonov ◽

Joshua W. Makepeace ◽

...

Keyword(s):

Dipole Moments ◽

Interaction Strength ◽

Magnetic Interaction ◽

Energy Scale ◽

Spin Ice ◽

Structural Behaviour ◽

Geometric Frustration ◽

Cadmium Cyanide ◽

The Difference ◽

Increased Strength

AbstractSpin-ices are frustrated magnets that support a particularly rich variety of emergent physics. Typically, it is the interplay of magnetic dipole interactions, spin anisotropy, and geometric frustration on the pyrochlore lattice that drives spin-ice formation. The relevant physics occurs at temperatures commensurate with the magnetic interaction strength, which for most systems is 1–5 K. Here, we show that non-magnetic cadmium cyanide, Cd(CN)2, exhibits analogous behaviour to magnetic spin-ices, but does so on a temperature scale that is nearly two orders of magnitude greater. The electric dipole moments of cyanide ions in Cd(CN)2 assume the role of magnetic pseudospins, with the difference in energy scale reflecting the increased strength of electric vs magnetic dipolar interactions. As a result, spin-ice physics influences the structural behaviour of Cd(CN)2 even at room temperature.

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Universal relations for ultracold reactive molecules

Science Advances ◽

10.1126/sciadv.abd4699 ◽

2020 ◽

Vol 6 (51) ◽

pp. eabd4699

Author(s):

Mingyuan He ◽

Chenwei Lv ◽

Hai-Qing Lin ◽

Qi Zhou

Keyword(s):

Critical Role ◽

Interaction Strength ◽

Quantum Correlations ◽

Polar Molecules ◽

Many Body ◽

Density Correlation ◽

Ultracold Polar Molecules ◽

Unexplored Area ◽

Many Body Systems

The realization of ultracold polar molecules in laboratories has pushed physics and chemistry to new realms. In particular, these polar molecules offer scientists unprecedented opportunities to explore chemical reactions in the ultracold regime where quantum effects become profound. However, a key question about how two-body losses depend on quantum correlations in interacting many-body systems remains open so far. Here, we present a number of universal relations that directly connect two-body losses to other physical observables, including the momentum distribution and density correlation functions. These relations, which are valid for arbitrary microscopic parameters, such as the particle number, the temperature, and the interaction strength, unfold the critical role of contacts, a fundamental quantity of dilute quantum systems, in determining the reaction rate of quantum reactive molecules in a many-body environment. Our work opens the door to an unexplored area intertwining quantum chemistry; atomic, molecular, and optical physics; and condensed matter physics.

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Single-File Water Flux Through Two-Dimensional Nanoporous Membranes

Nanoscale Research Letters ◽

10.1186/s11671-020-03436-4 ◽

2020 ◽

Vol 15 (1) ◽

Author(s):

Myung Eun Suk

Keyword(s):

Water Flux ◽

Interaction Strength ◽

High Water ◽

Potential Of Mean Force ◽

Proximal Region ◽

Dominant Factor ◽

Chemical Characteristics ◽

Nanoporous Membranes ◽

Two Dimensional ◽

Single File

Abstract Recent advances in the development of two-dimensional (2D) materials have facilitated a wide variety of surface chemical characteristics obtained by composing atomic species, pore functionalization, etc. The present study focused on how chemical characteristics such as hydrophilicity affects the water transport rate in hexagonal 2D membranes. The membrane–water interaction strength was tuned to change the hydrophilicity, and the sub-nanometer pore was used to investigate single-file flux, which is known to retain excellent salt rejection. Due to the dewetting behavior of the hydrophobic pore, the water flux was zero or nominal below the threshold interaction strength. Above the threshold interaction strength, water flux decreased with an increase in interaction strength. From the potential of mean force analysis and diffusion coefficient calculations, the proximal region of the pore entrance was found to be the dominant factor degrading water flux at the highly hydrophilic pore. Furthermore, the superiority of 2D membranes over 3D membranes appeared to depend on the interaction strength. The present findings will have implications in the design of 2D membranes to retain a high water filtration rate.

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Two-term expansion of the ground state one-body density matrix of a mean-field Bose gas

Calculus of Variations and Partial Differential Equations ◽

10.1007/s00526-021-01954-2 ◽

2021 ◽

Vol 60 (3) ◽

Author(s):

Phan Thành Nam ◽

Marcin Napiórkowski

Keyword(s):

Density Matrix ◽

Ground State ◽

Mean Field ◽

Interaction Strength ◽

Bose Gas ◽

Body Density ◽

The Mean ◽

The One ◽

Mean Field Regime ◽

Number Of Particles

AbstractWe consider the homogeneous Bose gas on a unit torus in the mean-field regime when the interaction strength is proportional to the inverse of the particle number. In the limit when the number of particles becomes large, we derive a two-term expansion of the one-body density matrix of the ground state. The proof is based on a cubic correction to Bogoliubov’s approximation of the ground state energy and the ground state.

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