10,749 research outputs found

    Surface-induced magnetism in C-doped SnO2_{2}

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    The magnetism of C-doped SnO2_{2} (001) surfaces is studied using first-principles calculations. It is found that carbon does not induce magnetism in bulk SnO2_{2} when located at the oxygen site, but shows a large magnetic moment at the SnO2_{2} (001) surface. The magnetic moment is mainly contributed by the carbon atoms due to empty minority spins of pp orbitals and is localized at the surface and subsurface atoms. No magnetism is observed when the carbon atom is located at the subsurface oxygen sites. The origin of magnetism is discussed in the context of surface bonding.Comment: 3 pages, 3 figure

    Non-equilibrium transport response from equilibrium transport theory

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    We propose a simple scheme that describes accurately essential non-equilibrium effects in nanoscale electronics devices using equilibrium transport theory. The scheme, which is based on the alignment and dealignment of the junction molecular orbitals with the shifted Fermi levels of the electrodes, simplifies drastically the calculation of current-voltage characteristics compared to typical non-equilibrium algorithms. We probe that the scheme captures a number of non-trivial transport phenomena such as the negative differential resistance and rectification effects. It applies to those atomic-scale junctions whose relevant states for transport are spatially placed on the contact atoms or near the electrodes.Comment: 5 pages, 4 figures. Accepted in Physical Review

    Motivations and decisive factors in women's entrepreneurship: a gender perspective in education and professional guidance

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    Ponencia de 7th International Conference on Intercultural Education “Education, Health and ICT for a Transcultural World”, EDUHEM 2016, AlmeriaPartial results of the Project R&D, Career Design and entrepreneurial talent management, of national dimension, funded by the Ministry of Economy and Competitiveness in the call for Excellence 2013 State Plan 2013 - 2016 with reference: EDU2013 - 45704 - P. Specifically we focus on (subject) describe and analyze the situation of Andalusian women confronting the entrepreneurship, their motivations and the factors that influence these processes and, all including a gender perspective. The objectives refer to: 1) Describing the situation of Andalusian women in entrepreneurship ; 2) Understanding and explain the motivations and decisions that drive them to take; 3) Identifying and describing the ( positive and negative) conditions that perceive women against undertaking; 4) Understanding from a gender analysis the positions of women on entrepreneurship related to their life projects. A descriptive and qualitative methodology is combined, collecting info rmation through various techniques such as social indicators, observational documentary sources and procedures, as well as interviews and life stories. Results and Conclusions. The findings so far point to an unequal situation regarding entrepreneurship. Relevant results are also obtained as to the incentives and decisions that drive to undertake, either obligation, because of the limited supply and possibilities of market access to paid employment , or vocation, leading us to question what barriers - internal - external and more or less subtle ones operating in these processes. On this issue we find factors that result in inequalities, such as maternity (number of children) and family and dependency (care) all for the economic and employment model that still prevails responsibilitie

    Female labour supply and income taxation in Spain: The importance of behavioural assumptions and unobserved heterogeneity specification

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    We estimate four models of female labour supply using a Spanish sample of married women from 1994, taking into account the complete form of the individual’s budget set. The models differ in the hypotheses relating to the presence of optimisation errors and/or the way non-workers contribute to the likelihood function. According to the results, the effects of wages and non-labour income on the labour supply of Spanish married women depend on the specification used. The model which has both preference and optimisation errors and allows for both voluntarily and involuntarily unemployed females desiring to participate seems to better fit the evidence for Spanish married women. Classification-JEL : J22labour supply, optimization errors, budget set.

    Structure and electronic properties of molybdenum monoatomic wires encapsulated in carbon nanotubes

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    Monoatomic chains of molybdenum encapsulated in single walled carbon nanotubes of different chiralities are investigated using density functional theory. We determine the optimal size of the carbon nanotube for encapsulating a single atomic wire, as well as the most stable atomic arrangement adopted by the wire. We also study the transport properties in the ballistic regime by computing the transmission coefficients and tracing them back to electronic conduction channels of the wire and the host. We predict that carbon nanotubes of appropriate radii encapsulating a Mo wire have metallic behavior, even if both the nanotube and the wire are insulators. Therefore, encapsulating Mo wires in CNT is a way to create conductive quasi one-dimensional hybrid nanostructures.Comment: 8 pages, 10 figure

    Impact of dimerization and stretching on the transport properties of molybdenum atomic wires

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    We study the electrical and transport properties of monoatomic Mo wires with different structural characteristics. We consider first periodic wires with inter-atomic distances ranging between the dimerized wire to that formed by equidistant atoms. We find that the dimerized case has a gap in the electronic structure which makes it insulating, as opposed to the equidistant or near-equidistant cases which are metallic. We also simulate two conducting one-dimensional Mo electrodes separated by a scattering region which contains a number of dimers between 1 and 6. The IVI-V characteristics strongly depend on the number of dimers and vary from ohmic to tunneling, with the presence of different gaps. We also find that stretched chains are ferromagnetic.Comment: 8 pages, 7 figure

    Effective and neutral stresses in soils using boundary element methods

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    The evaluation of neutral pressures in soil mechanics problems is a fundamental step to evaluate deformations in soils. In this paper, we present some results obtained by using the boundary element method for plane problems, describing the undrained situation as well as the consolidation problem

    Planning hand-arm grasping motions with human-like appearance

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    © 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting /republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other worksFinalista de l’IROS Best Application Paper Award a la 2018 IEEE/RSJ International Conference on Intelligent Robots and Systems, ICROS.This paper addresses the problem of obtaining human-like motions on hand-arm robotic systems performing pick-and-place actions. The focus is set on the coordinated movements of the robotic arm and the anthropomorphic mechanical hand, with which the arm is equipped. For this, human movements performing different grasps are captured and mapped to the robot in order to compute the human hand synergies. These synergies are used to reduce the complexity of the planning phase by reducing the dimension of the search space. In addition, the paper proposes a sampling-based planner, which guides the motion planning ollowing the synergies. The introduced approach is tested in an application example and thoroughly compared with other state-of-the-art planning algorithms, obtaining better results.Peer ReviewedAward-winningPostprint (author's final draft
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