Multifloquet to single electronic channel transition in the transport properties of a resistive 1D driven disordered ring

We investigate the dc response of a 1D disordered ring coupled to a reservoir and driven by a magnetic flux with a linear dependence on time. We identify two regimes: (i) A localized or large length L regime, characterized by a dc conductance, g_{dc}, whose probability distribution P(g_{dc}) is identical to the one exhibited by a 1D wire of the same length L and disorder strength placed in a Landauer setup. (ii) A "multifloquet" regime for small L and weak coupling to the reservoir, which exhibits large currents and conductances that can be g_{dc} > 1, in spite of the fact that the ring contains a single electronic transmission channel. The crossover length between the multifloquet to the single channel transport regime, L_c, is controlled by the coupling to the reservoir.Comment: 5 pages, 4 figure

DC four point resistance of a double barrier quantum pump

We investigate the behavior of the dc voltage drop in a periodically driven double barrier structure (DBS) sensed by voltages probes that are weakly coupled to the system. We find that the four terminal resistance $R_{4t}$ measured with the probes located outside the DBS results identical to the resistance measured in the same structure under a stationary bias voltage difference between left and right reservoirs. This result, valid beyond the adiabatic pumping regime, can be taken as an indication of the universal character of $R_{4t}$ as a measure of the resistive properties of a sample, irrespectively of the mechanism used to induce the transport.Comment: 4 pages, 3 figure

Visual and refractive outcomes of 100 small incision lenticule extractions (SMILE) in moderate and high myopia: a 24-month follow-up study

Purpose: We aimed to present the visual results obtained in 100 small incision lenticule extraction (SMILE) refractive surgeries, demonstrate whether the technique is effective in the treatment of moderate and high myopia, and observe the follow-up of these patients over 24-month period. Methods: One hundred eyes of 50 consecutive patients were treated with SMILE. The preoperative spherical equivalent refraction was − 5.64 ± 1.23 D. During the postoperative period, patients were examined at 3, 6, 12, and 24 months. We analysed the efficacy, safety, predictability, and stability of the technique. Results: The Snellen visual acuity of 99% of the patients was 20/20 or better after 24 months of follow-up. Two eyes had a loss of two lines of visual acuity; 1% of the patients had a loss of one line of visual acuity. The postoperative spherical refraction was − 0.04 ± 0.35 D (− 1.00 to 0.50 D). The postoperative spherical equivalent refraction was − 0.19 ± 0.38 D (− 1.25 to 0.50 D). Eighty-three percent of the eyes were within ± 0.50 D, and 87% obtained a residual astigmatism of 0.50 D or less. Conclusion: The SMILE technique was demonstrated to be an effective, predictable, safe, and stable technique in the treatment of moderate-to-severe myopia during the 24-month follow-up. Long-term follow-up should be undertaken to observe possible refractive regressions

Influencia de los tratamientos tecnológicos sobre la estabilidad térmica de los hilados de poliéster-lana.

Para estudiar el comportamiento de los hilados de poliéster-lana ante un aumento de temperatura, se les ha sometido al Dinamómetro INSTRON equipado con una cámara de aire caliente capaz de alcanzar los 200°C, determinándose las curvas que caracterizan las tensiones del hilo debido a la contracción. Se estudian hilados que han sido sometidos a operaciones de vaporizado y tintura.Pour l'étude du comportement des filés polyester/laine face à une augmentation de température, ceux-ci ont été soumis au Dynamometre INSTRON lequel est muni d'une chambre à l'air chaud capable d'atteindre 200°C; on a déterminé les courbes caractérisant les tensions du fil, a cause du retrait. On étudie des filés qui ont subi des opérations de vaporisage et de teinture.Polyester/wool yarns were subjected to thermal treatment in an air heated chamber, maximum temperature attainable 200°C, attached to an Instron, Tensile Tester. The yarn behaviour was studied by analysing the curves of tensions generated due to contraction. The steamed and dyed yarns are studied.Peer Reviewe

Neutrino mass and nature through its mediation in atomic clock interference

The absolute mass of neutrinos and their nature are presently unknown. Aggregate matter has a coherent weak charge leading to a repulsive interaction mediated by a neutrino pair. Near its range at micron distances the virtual neutrinos are non-relativistic, giving a distinct behavior for Dirac versus Majorana mass terms. The magnitude and the distance dependence of the effective potential disentangle these fundamental properties of neutrinos. We propose an experiment to search for this potential based on the concept that the density dependent interaction of an atomic probe with a material source in one arm of an atomic clock interferometer generates a differential phase. The appropriate geometry of the device is selected using the saturation of the weak potential as a guide. The proposed experiment has the added benefit of being sensitive to gravity at micron distances. A strategy to suppress the competing Casimir-Polder interaction, depending on the electronic structure of the material source, as well as a way to compensate the gravitational interaction in the two arms of the interferometer is discussed.Comment: 13 pages, 5 figures, 2 table

Caracterización del daño en elementos estructurales tipo barra de material compuesto. Determinación de carga última

El objetivo principal del trabajo es realizar un análisis del comportamiento de barras de material compuesto hasta la carga última. Para ello, ha sido necesario establecer a partir de criterios de fallo láminas, modelos de progresión de daño. Para comprobar la validez de los modelos propuestos se han realizado una serie de ensayos simples utilizandlo probetas con secuencias de apilatlo [0]8, [(0/90)2]s, y [45/0/-45/0]s

The “borders of development” in the capitalist production of space in Chile

El presente artículo expone una investigación referida a la producción capitalista del espacio en Chile en el contexto del actual proceso de globalización. El planteamiento central es que el Estado chileno y su territorialidad han actuado, con notoriedad a partir de la década de los setenta, bajo una lógica de articulación y soporte en relación a una geografía del capital que se moviliza a nivel mundial. Este proceder ha llevado al surgimiento de lo que hemos denominado las "fronteras del desarrollo", cuya característica principal es la reconfiguración de la clásica territorialidad del Estado-nación al configurar espacios tanto nacionales como globales. Estas fronteras del desarrollo representan, como plantea el texto, un ícono clave en la producción capitalista del espacio en Chile al ser territorios que marcan zonas de contacto y apertura global más que clausura nacional.This article presents research related to the capitalist production of space in Chile in the context of the current globalization process. The central argument is that since the 1970s the Chilean State and its territoriality have acted under a clear logic of articulation and support in relation to a geography of capital that is mobilized worldwide. This has led to the emergence of what we have called "borders of development" whose main characteristic is the reconfiguration of the classic territoriality of the nation-state because it configures both national and global spaces. These borders of development represent, as the text proposes, a key icon in the capitalist production of space in Chile as territories that mark contact zones and global opening rather than national closure.Fil: Núñez, Andrés. Pontificia Universidad Católica de Chile; ChileFil: Arenas, Federico. Pontificia Universidad Católica de Chile; ChileFil: Sánchez, Rafael. Pontificia Universidad Católica de Chile; ChileFil: Urrutia Reveco, Santiago José. Universidad de Buenos Aires. Facultad de Filosofía y Letras. Instituto de Geografía "Romualdo Ardissone"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Evolution and study of a copycat effect in intimate partner homicides: A lesson from Spanish femicides

Objectives This paper focuses on the issue of intimate partner violence and, specifically, on the distribution of femicides over time and the existence of copycat effects. This is the subject of an ongoing debate often triggered by the social alarm following multiple intimate partner homicides (IPHs) occurring in a short span of time. The aim of this research is to study the evolution of IPHs and provide a far-reaching answer by rigorously analyzing and searching for patterns in data on femicides. Methods The study analyzes an official dataset, provided by the system VioGén of the Secretaría de Estado de Seguridad (Spanish State Secretariat for Security), including all the femicides occurred in Spain in 2007-2017. A statistical methodology to identify temporal interdepen-dencies in count time series is proposed and applied to the dataset. The same methodology can be applied to other contexts. Results There has been a decreasing trend in the number of femicides per year. No interdependen-cies among the temporal distribution of femicides are observed. Therefore, according to data, the existence of copycat effect in femicides cannot be claimed. Conclusions Around 2011 there was a clear change in the average number of femicides which has not picked up. Results allow for an informed answer to the debate on copycat effect in Spanish femicides. The planning of femicides prevention activities should not be a reaction to a perceived increase in their occurrence. As a copycat effect is not detected in the studied time period, there is no evidence supporting the need to censor media reports on femicides.The work by Torrecilla has been partially supported by Spanish Grant MTM2016-78751-P. The research of Liberatore has been supported by the Government of Spain, grant MTM2015-65803-R, and by the Government of Madrid, grant S2013/ICE-284

Conductance distributions of 1D-disordered wires at finite temperature and bias voltage

We calculate the distribution of the conductance G in a one-dimensional disordered wire at finite temperature T and bias voltage V in a independent-electron picture and assuming full coherent transport. At high enough temperature and bias voltage, where several resonances of the system contribute to the conductance, the distribution P(G(T,V)) can be represented with good accuracy by autoconvolutions of the distribution of the conductance at zero temperature and zero bias voltage. The number of convolutions depends on T and V. In the regime of very low T and V, where only one resonance is relevant to G(T,V), the conductance distribution is analyzed by a resonant tunneling conductance model. Strong effects of finite T and V on the conductance distribution are observed and well described by our theoretical analysis, as we verify by performing a number of numerical simulations of a one-dimensional disordered wire at different temperatures, voltages, and lengths of the wire. Analytical estimates for the first moments of P(G(T,V)) at high temperature and bias voltage are also provided.Comment: 9 pages, 7 figures, Submitted to PR