Atomistic molecular dynamics simulations of a composite consisting an ungrafted or grafted spherical silica nanoparticle embedded in melt 20-monomer atactic polystyrene chains have been performed. The structural properties the polymer vicinity studied. modifies structure its neighborhood. These changes increase for higher grafting densities and larger particle diameters. Mass number density profiles show layering around nanoparticle, which extends to ∼2 nm. In contrast, polymer's radius...

Silica nanoparticles (NPs) embedded in atactic polystyrene (PS) are simulated using coarse-grained (CG) potentials obtained via iterative Boltzmann inversion (IBI). The parametrized and validated on of 2 kDa (i.e., chains containing 20 monomers). It is shown that the CG transferable between different systems. structure polymer strongly influenced by NP. Layering, chain expansion, preferential orientation segments as well entire found. extent structural perturbation depends details system:...

The thermal conductivity of single-walled and multi-walled carbon nanotubes has been investigated as a function the tube length L, temperature chiral index using non-equilibrium molecular dynamics simulations. In ballistic–diffusive regime follows Lα law. exponent α is insensitive to diameter nanotube; α≈0.77 derived for short at room temperature. dependence shows peak before falling higher temperatures (>500 K). phenomenon rectification in by gradually changing atomic mass tube-axial...

The chain and segmental dynamics of free grafted 20-monomer atactic polystyrene chains surrounding a silica nanoparticle have been investigated employing atomistic molecular simulations. effect the curvature grafting density on mean square displacement also relaxation time various intramolecular vectors was as function separation from surface. Confinement, reduced surface curvature, densification resulted in reduction an increase Cα–H bond vector end-to-end vicinity Depending property...

A model reference adaptive control law is defined for nonlinear distributed parameter systems. The assumed to be governed by a strongly coercive linear operator with respect Gelfand triple of reflexive Banach and Hilbert spaces. resulting closed-loop system shown well posed. tracking error converge zero, regularity results the input output are established. With an additional richness, or persistence excitation assumption, zero as well. finite-dimensional approximation theory developed....

Temporal optical soliton molecules were recently demonstrated; they potentially allow a further increase of data rates in telecommunication. We present theoretical study aimed at an explanation the mechanism responsible for binding force. To this end we use perturbation treatment several variants. find that well-known interaction as mediated by Kerr effect, when suitably modified chirped pulses, captures essential features like existence stable equilibrium separation and small-scale...

Abstract A clear tabulation of sets special points in numerical integrations over Brillouin zones ( BZ ) is given for the five two‐dimensional Bravais lattices. The derived on basis plain geometrical criteria coincide with a case large unit cell LUC method. This similarity also found other generation procedures k‐grids reported literature; that is, corresponding techniques have their common origin approach. underlying integration procedure described scheme based discrete summation, which...

Abstract Reactive molecular dynamics (RMD) implementations equipped with force field approaches to simulate both the time evolution as well chemical reactions of a broad class materials are reviewed herein. We subdivide RMD developed during last decade older ones already in 1995 by Srivastava and Garrison 2000 Brenner into two classes. The methods first rely on use reaction cutoff distance employ sudden transition from educts products. Due their simplicity these suited generate equilibrated...

We report a multi-chain approach for dissipative particle dynamics where the uncrossability constraints of polymer chains are mimicked by temporary cross-links, so-called slip-springs. The conformational statistics not affected introduction Dynamical properties such as mean square displacements, diffusion coefficient, and longest relaxation time in good agreement with results reptation theory. According to our analysis, present formalism is 500 times faster requires 7 fewer beads than...

The mechanical behavior of polystyrene and a silica-polystyrene nanocomposite under uniaxial elongation has been studied using coarse-grained molecular dynamics technique. Young's modulus, the Poisson ratio stress-strain curve have computed for range temperatures, below above glass transition temperature. predicted temperature dependence modulus is compared to experimental data predictions from atomistic simulations. observed related local structure polymer matrix around nanoparticles. Local...

Dispersion engineering in silicon nitride (SiXNY) waveguides is investigated through the optimization of waveguide transversal dimensions and refractive indices a multicladding arrangement. Ultraflat dispersion −84.0±0.5  ps/nm/km between 1700 2440 nm 1.5±3  ps/nm/km 1670 2500 nm numerically demonstrated. It shown that typical index fluctuations as well dimension during fabrication SiXNY are limitation for obtaining ultraflat profiles....

An interdisciplinary research team of the University Stuttgart has been working extensively since 2017 on development and integration adaptive systems technologies in order to provide solutions for a more sustainable built environment. experimental 36.5 m tall high-rise building, called D1244, was designed completed 2021 show potential structures facades as well verify real scale developed related numerical predictions. The building offer flexible platform: each component is dismountable so...

Abstract A systematic collection of spatial domains for reciprocal space integrations is derived all possible crystal symmetries. This set can be used as a simpler alternative to the conventional Brillouin zones. The analysis restricted where function in integrand satisfies inversion symmetry k space. In this case only 24 different have defined order allow 230 graphic representation asymmetric unit each integration given. Special positions and associated weighting factors required numerical...

The thermal conductivity in a set of mass-graded nanosized model systems has been studied by nonequilibrium molecular dynamics (MD) simulations order to understand the phenomenon rectification that detected externally mass-loaded nanotubes. We have found preferred direction heat transport nanotubes occurs from light heavy atoms while opposite transfer is observed anharmonic single-file chains. Mass-graded polyacetylenelike chains behave like as long mass gradient held backbone atoms. with...

Abstract Adaptive structures in civil engineering are mechanical with the ability to modify their response external loads. Actuators strongly affect a structure’s adaptivity and have be placed thoughtfully design process effectively compensate For constant loads, this property is introduced as steady-state disturbance compensability. This can linked concepts from structural such redundancy or statical indeterminacy, thus representing an interdisciplinary approach. Based on compensability...

Abstract Adaptive structures are equipped with sensors and actuators to actively counteract external loads such as wind. This can significantly reduce resource consumption emissions during the life cycle compared conventional structures. A common approach for active damping is derive a port-Hamiltonian model employ linear-quadratic control. However, quadratic control penalization lacks physical interpretation merely serves regularization term. Rather, we propose controller, which achieves...

Temporal optical soliton molecules were recently demonstrated; they potentially allow further increase of data rates in telecommunication. Their binding mechanism relies on the internal phases, but these have not been experimentally accessible so far. Conventional frequency-resolved gating techniques are suited for measurement their phase profile: algorithms fail to converge due zeros both temporal and spectral profile. We show that VAMPIRE (very advanced method intensity retrieval...

Abstract The He (I) photoelectron (PE.) spectra of bis (π‐allyl)palladium (2a) , (π‐allyl)platinum (3a) (π‐methallyl)palladium (2b) and (π‐methallyl)‐platinum (3b) have been recorded compared with the PE. (π‐allyl)nickel (1a) (π‐methallyl)nickel (1b) . By use (II) 2a, 2b 3b correlations between 1–3 it is possible to assign first seven eight transitions in In contrast previous assignments shown that band spectrum 1a corresponds ejection an electron from 7a u a pure ligand orbital. assignment...

The present molecular dynamics study is an investigation of the temperature (T) dependence liquid hexane coarse-grained potentials optimized with Iterative Boltzmann Inversion method. An approach for derivation at temperatures T different from optimization T(0) has recently been proposed ethylbenzene. This method based on use a T-dependent scaling factor f(T) to generate ethylbenzene T≠T(0). here extended hexane, considering reference and functional forms f(T). From our simulations, it...

We introduce an analytical model to rapidly determine the thermal conductivity reduction due mass disorder in nanomaterials. Although this simplified classical depends only on masses of different atoms, it adequately describes changes transport as concentrations these atoms vary. Its predictions compare satisfactorily with nonequilibrium molecular dynamics simulations (14)C-(12)C carbon nanotubes well previous other materials. present a simple tool quantitatively estimate decrease that is...

This article introduces a simple and fast method to reinsert atomistic details into mesoscale models of polymers with rigid side groups. We describe our backmapping scheme from coarse-grained (CG) resolution an picture in the framework molecular dynamics (MD) simulations silica–atactic polystyrene (PS) composite. The CG model Qian et al. [Macromolecules 2008, 41, 9919] has been used coarse-graining; it combines atoms one repeat unit PS bead. In reverse mapping only centers mass these units...