Search results for "MECHANICS"
showing 10 items of 9361 documents
Pullout Force and Inlet Oscillation in Telescopic Carbon Nanotubes: A Quantum Study
2021
The noncovalent interaction energy as a function of the core extension in double-walled carbon nanotubes (DWCNT) was accurately calculated in the frame of density functional theory, considering dis...
Deterministic folding in stiff elastic membranes.
2008
Crumpled membranes have been found to be characterized by complex patterns of spatially seemingly random facets separated by narrow ridges of high elastic energy. We demonstrate by numerical simulations that compression of stiff elastic membranes with small randomness in their initial configurations leads to either random ridge configurations (high entropy) or nearly deterministic folds (low elastic energy). For folding with symmetric ridge configurations to appear in part of the crumpling processes, the crumpling rate must be slow enough. Folding stops when the thickness of the folded structure becomes important, and crumpling continues thereafter as a random process.
The viscous-brittle transition of crystal-bearing slilic melt: direct observation of magma rupture and healing
2012
Magmas may fl ow or break depending on their deformation rate. The transition between such viscous and brittle behavior controls the style of volcanic eruptions. While the brittle failure of silicate melts is reasonably well characterized, the effect of crystals on the viscous-brittle transition has not yet been constrained. Here we examine the effect of suspended crystals on the mechanical failure of magmas using torsion experiments performed at temperatures (600‐ 900 °C), strain rates (10 ‐4 ‐10 ‐1 s ‐1 ), and confi ning pressures (200‐300 MPa) relevant for volcanic systems. We present a relationship that predicts the critical stress and associated strain rate at which magmas fail as a fu…
Sketching Sound with Voice and Gesture
2015
Voice and gestures are natural sketching tools that can be exploited to communicate sonic interactions. In product and interaction design, sounds should be included in the early stages of the design process. Scientists of human motion have shown that auditory stimuli are important in the performance of difficult tasks and can elicit anticipatory postural adjustments in athletes. These findings justify the attention given to sound in interaction design for gaming, especially in action and sports games that afford the development of levels of virtuosity. The sonic manifestations of objects can be designed by acting on their mechanical qualities and by augmenting the objects with synthetic and…
A boundary condition for arbitrary shaped inlets in lattice-Boltzmann simulations
2009
We introduce a mass-flux-based inlet boundary condition for the lattice-Boltzmann method. The proposed boundary condition requires minimal amount of boundary data, it produces a steady-state velocity field which is accurate close to the inlet even for arbitrary inlet geometries, and yet it is simple to implement. We demonstrate its capability for both simple and complex inlet geometries by numerical experiments. For simple inlet geometries, we show that the boundary condition provides very accurate inlet velocities when Re less than or similar to 1. Even with moderate Reynolds number, the inlet velocities are accurate for practical purposes. Furthermore, the potential of our boundary condit…
Geomechanical Behavior of Shales
2016
The paper presents the recent advances and their relevance in the study of the geomechanical behavior of shales considering both experimental and modelling aspects. Shales are involved in several energy-related engineering applications where complex multiphysical conditions are encountered. Partial saturation, non-isothermal conditions, plasticity and damage mechanisms may have a fundamental impact on their geomechanical behavior. The relevance of these aspects for shales is presented in the paper both from advance experimental and modeling point of view.
Many-body Green's function theory for electron-phonon interactions: ground state properties of the Holstein dimer
2015
We study ground-state properties of a two-site, two-electron Holstein model describing two molecules coupled indirectly via electron-phonon interaction by using both exact diagonalization and self-consistent diagrammatic many-body perturbation theory. The Hartree and self-consistent Born approximations used in the present work are studied at different levels of self-consistency. The governing equations are shown to exhibit multiple solutions when the electron-phonon interaction is sufficiently strong whereas at smaller interactions only a single solution is found. The additional solutions at larger electron-phonon couplings correspond to symmetry-broken states with inhomogeneous electron de…
A possible quantum motivation of the structure of quantum group
2011
We propose a (first) simple natural model of a non-finitely generated braided non-commutative Hopf Algebra, suggested by the elementary quantum mechanics.
Biceps Femoris Long Head Muscle Fascicles Actively Lengthen During the Nordic Hamstring Exercise
2021
Current debate exists around whether a presumed eccentric exercise, the Nordic hamstring exercise (NHE), actually causes active hamstring muscle lengthening. This is because of the decoupling that can occur between the muscle fascicle and muscle-tendon unit (MTU) length changes in relatively compliant human lower-limb MTUs, which results in MTU lengthening not necessarily causing muscle fascicle lengthening. This missing knowledge complicates the interpretation of why the NHE is effective at reducing running-related hamstring muscle injury risk in athletes previously unfamiliar with performing this exercise. The purpose of the study was therefore to investigate if the most-commonly injured …
Flow dominance and factorization of transverse momentum correlations in Pb-Pb collisions at the LHC
2017
Physical review letters 118(16), 162302 (2017). doi:10.1103/PhysRevLett.118.162302