Characteristic Length Scales and Radial Monomer Density Profiles of Molecular Bottle-Brushes: Simulation and Experiment

2010 ◽  
Vol 43 (3) ◽  
pp. 1592-1601 ◽  
Author(s):  
Hsiao-Ping Hsu ◽  
Wolfgang Paul ◽  
Silke Rathgeber ◽  
Kurt Binder
Keyword(s):  
Characteristic Length ◽  
Density Profiles ◽  
Length Scales ◽  
Simulation And Experiment ◽  
Monomer Density ◽  
Bottle Brushes

scholarly journals Investigation of Ring and Star Polymers in Confined Geometries: Theory and Simulations

Entropy ◽  
2021 ◽  
Vol 23 (2) ◽  
pp. 242
Author(s):  
Joanna Halun ◽  
Pawel Karbowniczek ◽  
Piotr Kuterba ◽  
Zoriana Danel
Keyword(s):  
Star Polymers ◽  
Polymer Chains ◽  
The Other ◽  
Nano Particles ◽  
Dilute Solution ◽  
Confined Geometries ◽  
Density Profiles ◽  
Ideal Ring ◽  
Ring Polymer ◽  
Monomer Density

The calculations of the dimensionless layer monomer density profiles for a dilute solution of phantom ideal ring polymer chains and star polymers with f=4 arms in a Θ-solvent confined in a slit geometry of two parallel walls with repulsive surfaces and for the mixed case of one repulsive and the other inert surface were performed. Furthermore, taking into account the Derjaguin approximation, the dimensionless layer monomer density profiles for phantom ideal ring polymer chains and star polymers immersed in a solution of big colloidal particles with different adsorbing or repelling properties with respect to polymers were calculated. The density-force relation for the above-mentioned cases was analyzed, and the universal amplitude ratio B was obtained. Taking into account the small sphere expansion allowed obtaining the monomer density profiles for a dilute solution of phantom ideal ring polymers immersed in a solution of small spherical particles, or nano-particles of finite size, which are much smaller than the polymer size and the other characteristic mesoscopic length of the system. We performed molecular dynamics simulations of a dilute solution of linear, ring, and star-shaped polymers with N=300, 300 (360), and 1201 (4 × 300 + 1-star polymer with four arms) beads accordingly. The obtained analytical and numerical results for phantom ring and star polymers are compared with the results for linear polymer chains in confined geometries.

Flow transitions and length scales of a channel-confined active nematic

Soft Matter ◽  
2021 ◽  
Author(s):  
Abhik Samui ◽  
Julia M. Yeomans ◽  
Sumesh P. Thampi
Keyword(s):  
Characteristic Length ◽  
Flow Regimes ◽  
Channel Width ◽  
Flow Structures ◽  
Length Scale ◽  
Length Scales ◽  
Turbulence Regime ◽  
Active Turbulence ◽  
Intrinsic Length ◽  
Flow Transitions

Different flow regimes realised by a channel-confined active nematic have a characteristic length same as channel width. Flow structures exhibit the intrinsic length scale of the fluid only in the fully developed active turbulence regime.

Characteristic length scales of nanosize zinc ferrite

2005 ◽  
Vol 17 (1) ◽  
pp. 232-237 ◽  
Author(s):  
M K Roy ◽  
Bidyut Haldar ◽  
H C Verma
Keyword(s):  
Zinc Ferrite ◽  
Characteristic Length ◽  
Length Scales

High-Frequency Seismic Wave Propagation in Northeastern North America

1990 ◽  
Vol 61 (3-4) ◽  
pp. 193-208 ◽  
Author(s):  
S. E. Hough ◽  
K. H. Jacob ◽  
L. Seeber
Keyword(s):  
North America ◽  
High Frequency ◽  
Characteristic Length ◽  
Body Waves ◽  
Eastern North America ◽  
Western North America ◽  
Energy Propagation ◽  
Length Scales ◽  
Near Surface ◽  
High Frequencies

Abstract A key element in the assessment of seismic hazard is the estimation of how energy propagation from a given earthquake is affected by crustal structure near the receiver and along the more distant propagation path. In this paper, we present data from a variety of sources in eastern North America recorded at epicentral distances of a few to 800 km, and characterize and interpret systematic features. Site effects have been classically considered in terms of amplification either within a sediment-filled valley or from a single topographic feature (Geli et al., 1988). We present evidence of high frequency (5–30 Hz) resonances observed in hard-rock recordings of both body waves and Lg waves, and suggest that site effect should be expanded regionally to include structural and topographic information over sufficiently large areas to include several wavelengths of any features that may interact with seismic waves in the frequency range of interest. A growing body of evidence suggests that ground motions at high frequencies recorded at large epicentral distances in eastern North America are controlled by resonance effects. We hypothesize that a fundamental difference between eastern and western North America spectra stems from a combination of differences in the character of topography and near-surface structure. Active tectonics of western North America gives rise to a complex crust that scatters seismic energy in a random manner and results in very effective attenuation of high frequencies. The older eastern North American crust contains scatterers that are more ordered, with characteristic length scales that give rise to resonance phenomena in the frequency band critical for earthquake hazard. We present preliminary analysis of topographic data from the Adirondack Mountains in New York that demonstrates the existence of characteristic length scales on the order of up to 1–3 kilometers. Features with these length scales will effectively scatter energy at frequencies in the 1 to 10 Hz range.

THREE-DIMENSIONAL PHONON TRANSPORT SIMULATION FOR NANO/MICROSTRUCTURED MATERIALS

2008 ◽  
Vol 07 (02n03) ◽  
pp. 103-112 ◽  
Author(s):  
A. SAKURAI ◽  
S. MARUYAMA ◽  
A. KOMIYA ◽  
K. MIYAZAKI
Keyword(s):  
Radiative Transfer ◽  
Heat Transport ◽  
Characteristic Length ◽  
Transport Phenomena ◽  
Three Dimensional ◽  
Phonon Transport ◽  
Discrete Ordinates ◽  
Complex Geometries ◽  
Transport Mechanisms ◽  
Length Scales

The Discrete Ordinates Radiation Element Method (DOREM), which is radiative transfer code, is applied for solving phonon transport of nano/microscale materials. The DOREM allows phonon simulation with multi-dimensional complex geometries. The objective of this study is to apply the DOREM to the nano/microstructured materials. It is confirmed that significant changes of the heat transport phenomena with different characteristic length scales and geometries are observed. This study also discusses further variations for understanding of heat transport mechanisms.

scholarly journals Wetting of Nematic Liquid Crystals on Crenellated Substrates: A Frank–Oseen Approach

Crystals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 430 ◽  
Author(s):  
Óscar A. Rojas-Gómez ◽  
Margarida M. Telo da Gama ◽  
José M. Romero-Enrique
Keyword(s):  
Liquid Crystals ◽  
Characteristic Length ◽  
Nematic Liquid Crystals ◽  
Energy Contribution ◽  
Macroscopic Scale ◽  
Length Scales ◽  
Correlation Lengths ◽  
Anchoring Transitions ◽  
Interfacial States ◽  
Free Energy Contribution

We revisit the wetting of nematic liquid crystals in contact with crenellated substrates, studied previously using the Landau–de Gennes formalism. However, due to computational limitations, the characteristic length scales of the substrate relief considered in that study limited to less than 100 nematic correlation lengths. The current work uses an extended Frank–Oseen formalism, which includes not only the free-energy contribution due to the elastic deformations but also the surface tension contributions and, if disclinations or other orientational field singularities are present, their core contributions. Within this framework, which was successfully applied to the anchoring transitions of a nematic liquid crystal in contact with structured substrates, we extended the study to much larger length scales including the macroscopic scale. In particular, we analyzed the interfacial states and the transitions between them at the nematic–isotropic coexistence.

Sign in / Sign up

Export Citation Format

Share Document