2,063 research outputs found

    Design Space Investigation by RSMs Techniques in Aeronautical Metal Cutting Applications

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    none3A. DEL PRETE; A. DE VITIS; D. MAZZOTTADEL PRETE, Antonio; DE VITIS, ANTONIO ALBERTO; D., Mazzott

    Poplar roundwood yield : according to diameter classes

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    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 aserrío de una muestra de Populus x deltoides cv. Harvard, según clases diamétricas. Los rendimientos de aserrío 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

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    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

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    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

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    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

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    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

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    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

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    We investigate a transition between a two-dimensional topological insulator conduction state, characterized by a conductance G=2G=2 (in fundamental units e2/he^2/h) and a Chern insulator with G=1G=1, 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 G=1G=1 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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