Atomistic simulations are performed to study the nonlinear mechanical behavior of graphene nanoribbons under quasistatic uniaxial tension, emphasizing the effects of edge structures (armchair and zigzag, without and with hydrogen passivation) on elastic modulus and fracture strength. The numerical results are analyzed within a theoretical model of thermodynamics, which enables determination of ...

For many years, the local public has had the notion that university engineering graduates are strong in theory because that is what we teach here. Polytechnic engineering students, however, are practice oriented because they are given more opportunities to use their hands in the classroom. When the NTU engineering schools were set up in 1984 the press emphasised that their graduates are better ...

Change in the bonding environment at the free edges of graphene monolayer leads to excess edge energy and edge force, depending on the edge morphology zigzag or armchair . By using a reactive empirical bond-order potential and atomistic simulations, we show that the excess edge energy in free-standing graphene nanoribbons can be partially relaxed by both in-plane and out-of-plane deformation. T...

In classical electrodynamics, nanostructured graphene is commonly modeled by the computationally demanding problem of a three-dimensional conducting film of atomic-scale thickness. Here, we propose an efficient alternative two-dimensional electrostatic approach where all calculation procedures are restricted to the graphene sheet. Furthermore, to explore possible quantum effects, we perform tig...

We studied the effect of age on the act of rising from a standard armchair in a younger (means = 24 years) and an older (means = 75 years) group of healthy adult women. Rising from a standard armchair and an armchair specially designed for comfort in sitting of the elderly was studied in the older group to determine the influence of the special chair. We used electrogoniometry, EMG, and videota...

The effects of graphene stacking are investigated by comparing the results of methane adsorption energy, electronic performance, and the doping feasibility of five dopants (i.e., B, N, Al, Si, and P) via first-principles theory. Both zigzag and armchair graphenes are considered. It is found that the zigzag graphene with Bernal stacking has the largest adsorption energy on methane, while the arm...

Figure 1: Example of a nanographite plan with rectangular shape. The boundaries have two different kinds of edges: the armchair and the zigzag edges. The wave functions of the edge states are preferentially localized on the zigzag edges

We theoretically study the magnetoresistance of single wall carbon nanotubes (SWCNTs) in the ballistic transport regime, using a standard tight-binding approach. The main attention is directed to spin-polarized electrical transport in the presence of either axial or perpendicular magnetic field. The method takes into account both Zeeman splitting as well as size and chirality effects. These fac...

We consider the effects of Coulomb interactions on single-wall carbon nanotubes using an on-site Hubbard interaction, u . For the ~N ,N! armchair tubes the low-energy theory is shown to be identical to a two-chain Hubbard model at half-filling, with an effective interaction uN5u/N . Umklapp scattering leads to gaps in the spectrum of charge and spin excitations which are exponentially small for...

I review literature on four different approaches to the study of traditions in animals: observation of free-living animals, laboratory experiment, armchair analysis, and field experiment. Because, by definition, a tradition entails social learning of some kind, it is difficult, perhaps impossible, to establish that a behavior is in fact traditional without knowledge of how it develops. Observat...