Polytelluride square planar chain-induced anharmonicity results in ultralow thermal conductivity and high thermoelectric efficiency in AlTe monolayers.

Two-dimensional (2D) metal chalcogenides provide rich ground for the development of nanoscale thermoelectrics, although achieving optimal thermoelectric efficiency is still a challenge. Here, we leverage the unique chemistry of tellurium (Te), renowned for its hypervalent bonding and catenation abilities, to tackle this challenge as manifested in AlTe and AlTe monolayers. While the former forms a straightforward covalent Al-Te network, the latter adopts a more intricate bonding mechanism, enabled by eccentric features of Te chemistry, to maintain charge balance.

The effects of physical morphologies and strain rate on piezoelectric potential of boron nitride nanotubes: a molecular dynamics simulation.

The growing demand for self-powered systems and the slow progress in energy storage devices have led to the emergence of piezoelectric materials as a promising solution for energy harvesting. This study aims to investigate the effects of chirality, length, and strain rate on the piezoelectric potential of boron nitride nanotubes (BNNTs) through molecular dynamics simulation. Accurate data and guidance are provided to explain the piezoelectricity of chiral nanotubes, as the piezoelectric potentials of these nanotubes have previously remained unclear.

Curvature and van der Waals interface effects on thermal transport in carbon nanotube bundles.

A van der Waals (vdW) heterostructure, can be used in efficient heat management, due to its promising anisotropic thermal transport feature, with high heat conductance in one direction and low conductance in the rest. A carbon nanotube (CNT) bundle, can be used as one of the most feasible vdW heterostructures in a wide range of nanoscale devices. However, detailed investigations of heat transport in CNT bundles are still lacking.

Diffusion and self-assembly of C60 molecules on monolayer graphyne sheets.

The motion of a fullerene (C60) on 5 different types of graphyne is studied by all-atom molecular dynamics simulations and compared with former studies on the motion of C60 on graphene. The motion shows a diffusive behavior which consists of either a continuous motion or discrete movements between trapping sites depending on the type of the graphyne sheet. For graphyne-4 and graphyne-5, fullerenes could detach from the surface of the graphyne sheet at room temperature which was not reported for similar cases on graphene sheets.

Structural and mechanical features of the order-disorder transition in experimental hard-sphere packings.

Here we present an experimental and numerical investigation on the grain-scale geometrical and mechanical properties of partially crystallized structures made of macroscopic frictional grains. Crystallization is inevitable in arrangements of monosized hard spheres with packing densities exceeding Bernal's limiting density ϕ(Bernal)≈0.64.

Semi-analytical solution for the in-vitro sedimentation, diffusion and dosimetry model: surveying the impact of the Peclet number.

Reducing size of the particles to the nanoscale range gives them new physicochemical properties. Several experiments have shown cytotoxic effects for different kinds of engineered nanoparticles (ENP). In-vitro cell culture assays are widely utilized by researchers to evaluate cytotoxic effects of the ENPs.

Geometrical exponents of contour loops on synthetic multifractal rough surfaces: multiplicative hierarchical cascade p model.

In this paper, we study many geometrical properties of contour loops to characterize the morphology of synthetic multifractal rough surfaces, which are generated by multiplicative hierarchical cascading processes. To this end, two different classes of multifractal rough surfaces are numerically simulated. As the first group, singular measure multifractal rough surfaces are generated by using the p model.

Nonuniversality of roughness exponent of quasistatic fracture surfaces.

Numerous experiments have indicated that the fracture front (in three dimensions) and crack lines (in two dimensions) in disordered solids and rocklike materials is rough. It has been argued that the roughness exponent ζ is universal. Using extensive simulations of a two-dimensional model, we provide strong evidence that if extended correlations and anisotropy-two features that are prevalent in many materials-are incorporated in the models that are used in the numerical simulation of crack propagation, then ζ will vary considerably with the extent of the correlations and anisotropy.

Shape of a wave front in a heterogenous medium.

Wave propagation in a heterogeneous medium, characterized by a distribution of local elastic moduli, is studied. Both acoustic and elastic waves are considered, as are spatially random and power-law correlated distributions of the elastic moduli with nondecaying correlations. Three models--a continuum scalar model, and two discrete models--are utilized.

Localization of elastic waves in heterogeneous media with off-diagonal disorder and long-range correlations.

Using the Martin-Siggia-Rose method, we study propagation of acoustic waves in strongly heterogeneous media which are characterized by a broad distribution of the elastic constants. Gaussian-white distributed elastic constants, as well as those with long-range correlations with nondecaying power-law correlation functions, are considered. The study is motivated in part by a recent discovery that the elastic moduli of rock at large length scales may be characterized by long-range power-law correlation functions.

Stochastic analysis and regeneration of rough surfaces.

We investigate the Markov property of rough surfaces. Using stochastic analysis, we characterize the complexity of the surface roughness by means of a Fokker-Planck or Langevin equation. The obtained Langevin equation enables us to regenerate surfaces with similar statistical properties compared with the observed morphology by atomic force microscopy.