1,547 research outputs found
Gender differences in working at home and time use patterns: evidence from Australia
Despite a wealth of research on working at home, few studies have examined the effects of working at home in relation to its regularity and fewer still have used time use studies to do so. Using data from the 2006 Australian Time Use Survey this article investigates the association between working at home, gender and time use, in relation to amount of time spent in paid work, unpaid work and recreational labour, as well as multi-tasking, fragmentation of time and scheduling flexibility. It examines time use patterns according to whether employees do no work at home or whether they work at home rarely, occasionally or regularly. Results show there is an association between working at home and time in paid and unpaid work and that this differs by the regularity of working at home and gender. Working at home does not create more time for recreational labour, although it may help women juggle work and family. © 2015, © The Author(s) 2015
Structural, elastic and thermal properties of cementite (FeC) calculated using Modified Embedded Atom Method
Structural, elastic and thermal properties of cementite (FeC) were
studied using a Modified Embedded Atom Method (MEAM) potential for iron-carbon
(Fe-C) alloys. Previously developed Fe and C single element potentials were
used to develop an Fe-C alloy MEAM potential, using a statistically-based
optimization scheme to reproduce structural and elastic properties of
cementite, the interstitial energies of C in bcc Fe as well as heat of
formation of Fe-C alloys in L and B structures. The stability of
cementite was investigated by molecular dynamics simulations at high
temperatures. The nine single crystal elastic constants for cementite were
obtained by computing total energies for strained cells. Polycrystalline
elastic moduli for cementite were calculated from the single crystal elastic
constants of cementite. The formation energies of (001), (010), and (100)
surfaces of cementite were also calculated. The melting temperature and the
variation of specific heat and volume with respect to temperature were
investigated by performing a two-phase (solid/liquid) molecular dynamics
simulation of cementite. The predictions of the potential are in good agreement
with first-principles calculations and experiments.Comment: 12 pages, 9 figure
Utilização de filmes termo-ativados como adesivos de nova geração para colagem de polímeros reforçados com fibras ao concreto
Ceramic Substrates for High-temperature Electronic Integration
One of the most attractive ways to increase power handling capacity in power modules is to increase the operating temperature using wide-band-gap semiconductors. Ceramics are ideal candidates for use as substrates in high-power high-temperature electronic devices. The present article aims to determine the most suitable ceramic material for this application
Optimal Packings of Superballs
Dense hard-particle packings are intimately related to the structure of
low-temperature phases of matter and are useful models of heterogeneous
materials and granular media. Most studies of the densest packings in three
dimensions have considered spherical shapes, and it is only more recently that
nonspherical shapes (e.g., ellipsoids) have been investigated. Superballs
(whose shapes are defined by |x1|^2p + |x2|^2p + |x3|^2p <= 1) provide a
versatile family of convex particles (p >= 0.5) with both cubic- and
octahedral-like shapes as well as concave particles (0 < p < 0.5) with
octahedral-like shapes. In this paper, we provide analytical constructions for
the densest known superball packings for all convex and concave cases. The
candidate maximally dense packings are certain families of Bravais lattice
packings. The maximal packing density as a function of p is nonanalytic at the
sphere-point (p = 1) and increases dramatically as p moves away from unity. The
packing characteristics determined by the broken rotational symmetry of
superballs are similar to but richer than their two-dimensional "superdisk"
counterparts, and are distinctly different from that of ellipsoid packings. Our
candidate optimal superball packings provide a starting point to quantify the
equilibrium phase behavior of superball systems, which should deepen our
understanding of the statistical thermodynamics of nonspherical-particle
systems.Comment: 28 pages, 16 figure
Deforming glassy polystyrene: Influence of pressure, thermal history, and deformation mode on yielding and hardening
The toughness of a polymer glass is determined by the interplay of yielding, strain softening, and strain hardening. Molecular-dynamics simulations of a typical polymer glass, atactic polystyrene, under the influence of active deformation have been carried out to enlighten these processes. It is observed that the dominant interaction for the yield peak is of interchain nature and for the strain
hardening of intrachain nature. A connection is made with the microscopic cage-to-cage motion. It is found that the deformation does not lead to complete erasure of the thermal history but that differences persist at large length scales. Also we find that the strain-hardening modulus increases with increasing external pressure. This new observation cannot be explained by current theories
such as the one based on the entanglement picture and the inclusion of this effect will lead to an improvement in constitutive modeling
Plastic Deformation of 2D Crumpled Wires
When a single long piece of elastic wire is injected trough channels into a
confining two-dimensional cavity, a complex structure of hierarchical loops is
formed. In the limit of maximum packing density, these structures are described
by several scaling laws. In this paper it is investigated this packing process
but using plastic wires which give origin to completely irreversible structures
of different morphology. In particular, it is studied experimentally the
plastic deformation from circular to oblate configurations of crumpled wires,
obtained by the application of an axial strain. Among other things, it is shown
that in spite of plasticity, irreversibility, and very large deformations,
scaling is still observed.Comment: 5 pages, 6 figure
- …