2,063 research outputs found
Design Space Investigation by RSMs Techniques in Aeronautical Metal Cutting Applications
none3A. DEL PRETE; A. DE VITIS; D. MAZZOTTADEL PRETE, Antonio; DE VITIS, ANTONIO ALBERTO; D., Mazzott
Poplar roundwood yield : according to diameter classes
El conocimiento de los rendimientos de la madera de álamo es importante para establecer alternativas de uso, lograr el máximo aprovechamiento y, a su vez, calcular los costos foresto-industriales. El objetivo de este trabajo fue determinar los rendimientos de aserrÃo de una muestra de Populus x deltoides cv. Harvard, según clases diamétricas. Los rendimientos de aserrÃo variaron de acuerdo con el diámetro, desde 65 % 45 a 65 %, para diámetros de rollizos de 10 a 40 cm.The knowledge of poplar wood yields is very important to constitute the diferent uses, to maximize his utility, and to calcúlate the forestal industrial costs. The objective of this paper is the determination of sawmill yields of a Populus x deltoides cv. Harvard sample according to diameter classes. Sawmill yields situates between 45 to reciprocate to diameters between 10 to 40 cm.Fil: Calderón, Alberto D..
Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Departamento de Producción AgropecuariaFil: Mastrantonio, Leandro.
Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Departamento de Producción Agropecuari
Interacting quantum walk on a graph
We introduce an elementary quantum system consisting of a set of spins on a
graph and a particle hopping between its nodes. The quantum state is build
sequentially, applying a unitary transformation that couples neighboring spins
and, at a node, the local spin with the particle. We observe the relaxation of
the system towards a stationary paramagnetic or ferromagnetic state, and
demonstrate that it is related to eigenvectors thermalization and random matrix
statistics. The relation between these macroscopic properties and interaction
generated entanglement is discussed.Comment: 15 pages, 11 figures (v2 extended version
Skyrmion collapse
We investigate the topological change of a Belavin-Polyakov skyrmion under
the action of a spin-polarized current. The dynamics is described by the
Schr\"odinger equation for the electrons carrying the current coupled to the
Landau-Lifshitz equation for the evolution of the magnetic texture in a square
lattice. We show that the addition of an exchange dissipation term, tends to
smooth the transition from the skyrmion state to the ferromagnetic state. We
demonstrate that this topological change, in the continuum dissipationless
limit, can be described as a self-similar finite-time singularity by which the
skyrmion core collapses.Comment: 9 pages, 6 figures; v2. discussion added (the title of the published
version is "Skyrmion to ferromagnetic state transition: A description of the
topological change as a finite-time singularity in the skyrmion dynamics"
Edge states in a two-dimensional quantum walk with disorder
We investigate the effect of spatial disorder on the edge states localized at
the interface between two topologically different regions. Rotation disorder
can localize the quantum walk if it is strong enough to change the topology,
otherwise the edge state is protected. Nonlinear spatial disorder, dependent on
the walker's state, attracts the walk to the interface even for very large
coupling, preserving the ballistic transport characteristic of the clean
regime.Comment: extended new version; 10 pages, 10 figure
Higher-order multipole amplitude measurement in ψ ′→γχ c2
Using 106×106 ψ ′ events collected with the BESIII detector at the BEPCII storage ring, the higher-order multipole amplitudes in the radiative transition ψ ′→γχ c2→γπ +π -/γK +K - are measured. A fit to the χ c2 production and decay angular distributions yields M2=0.046±0. 010±0.013 and E3=0.015±0.008±0.018, where the first errors are statistical and the second systematic. Here M2 denotes the normalized magnetic quadrupole amplitude and E3 the normalized electric octupole amplitude. This measurement shows evidence for the existence of the M2 signal with 4.4σ statistical significance and is consistent with the charm quark having no anomalous magnetic moment. © 2011 American Physical Society.published_or_final_versio
Topological changes of two-dimensional magnetic textures
We investigate the interaction of magnetic vortices and skyrmions with a
spin-polarized current. In a square lattice, fixed classical spins and quantum
itinerant electrons, evolve according to the coupled Landau-Lifshitz and
Schr\"odinger equations. Changes in the topology occur at microscopic time and
length scales, and are shown to be triggered by the nucleation of a nontrivial
electron-spin structure at the vortex core.Comment: See supplementary material (high resolution figures and movies)
https://drive.google.com/folderview?id=0By4j_RJ9SKLpQ2R5UklXLURvbEE&usp=sharing
--- v2: Extended versio
Anomalous quantum Hall effect induced by disorder in topological insulators
We investigate a transition between a two-dimensional topological insulator
conduction state, characterized by a conductance (in fundamental units
) and a Chern insulator with , induced by polarized magnetic
impurities. Two kinds of coupling, ferro and antiferromagnetic, are considered
with the electron and hole subbands. We demonstrate that for strong disorder, a
phase exists even for ferromagnetic order, in contrast with the
prediction of the mean field approximation. This result is supported by direct
numerical computations using Landauer transport formula, and by analytical
calculations of the chemical potential and mass renormalization as a function
of the disorder strength, in the self-consistent Born approximation. The
transition is related to the suppression of one of the spin conduction
channels, for strong enough disorder, by selective spin scattering and
localization.Comment: 9 pages, 4 figures (figs. 2 and 3 in low resolution
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