Analysis of self--averaging properties in the transport of particles through random media

We investigate self-averaging properties in the transport of particles through random media. We show rigorously that in the subdiffusive anomalous regime transport coefficients are not self--averaging quantities. These quantities are exactly calculated in the case of directed random walks. In the case of general symmetric random walks a perturbative analysis around the Effective Medium Approximation (EMA) is performed.Comment: 4 pages, RevTeX , No figures, submitted to Physical Review E (Rapid Communication

Modelos productivos de las denominaciones de origen protegidas de vino en España

El número de Denominaciones de Origen Protegidas de vino ha crecido mucho en España tras la incorporación a la Unión Europea. Nuestro objetivo es identificar modelos productivos diferentes, en función de cómo se combinan los factores de producción. A partir de las estadísticas del Ministerio de Agricultura, se ha construido una base de datos con las variables estructurales más significativas de cada denominación: superficie de viñedo, viticultores y bodegas inscritas; la serie temporal abarca las campañas agrícolas de este siglo. La combinación de factores de producción se expresa mediante dos indicadores obtenidos a partir de dichas variables: el cociente entre superficie y viticultores (tamaño medio de la explotación vitícola) y el cociente entre viticultores y bodegas (polaridad château-cooperativa). Sobre la base de ambos indicadores se ha realizado una clasificación de las denominaciones mediante un análisis clúster. Como resultado, en primer lugar se ha contrastado y evaluado la existencia de grandes diferencias de tamaño entre las denominaciones; en segundo lugar, se han identificado cinco modelos productivos diferentes. De la diversidad observada se concluye que Denominación de Origen Protegida es una figura legal que acoge realidades muy dispares, lo cual puede plantear problemas de gobernanza dentro del sector del vino. The number of wine Protected Designations of Origin has grown a lot in Spain after joining the European Union. Our objective is to identify different production models, depending on how production factors are combined. From the statistics of the Ministry of Agriculture, a database has been constructed with the most significant structural variables of each designation: area of vineyard, vine growers and registered wineries; the time series embraces the agricultural campaigns of 21st century. Combinations of production factors are expressed by two indicators obtained from these variables: the quotient between area and vine growers (average size of the vineyard) and the ratio of vine growers and wineries (château-cooperative polarity). On the basis of both indicators designations have been classified through a cluster analysis. Main findings are: first, the existence of large differences in size among denominations has been contrasted and evaluated; secondly, five different production models have been identified. From the observed diversity, it is concluded that Protected Designation of Origin is a legal entity that overcomes very different realities, which can raise problems of governance within the wine sector

Past, present, and future research on self-service merchandising: A co-word and text mining approach

Purpose This study aims to discern emerging trends and provide a longitudinal perspective on merchandising research by identifying relationships between merchandising-related subdomains/themes. Design/methodology/approach This study sourced 657 merchandising-related articles published since 1960, from the Scopus database and 425 from Web of Science. After processing and normalizing the data, this study performed co-word and thematic network analyses. Taking a text mining approach, this study used topic modeling to identify a set of coherent topics characterized by the keywords of the articles. Findings This study identified the following merchandising-related themes: branding, retail, consumer, behavior, modeling, textile and clothing industry and visual merchandising. Although visual merchandising was the first type of merchandising to be used in-store, only recently has it become an emerging topic in the academic literature. There has been a further trend over the past decade to understand the adoption of simulation technology, such as computer-aided design, particularly in supply chain management in the clothing industry. These and other findings contribute to the discussion of the merchandising concept, approached from an evolutionary perspective. Research limitations/implications The conclusions of this study hold implications at the intersection of merchandising, sectors, new technologies, research methodologies and merchandising-practitioner education. Research trends suggest that, in the future, virtual reality and augmented reality using neuroscientific methods will be applied to the e-merchandising context. Practical implications The different dimensions of merchandising can be used to leverage store managers’ decision-making process toward an integrated store-management strategy. In particular, by adopting loyalty merchandising tactics, the store can generate emotional attachment among consumers, who will perceive its value and services as unique, thanks to merchandising items designed specifically with that aim in mind. The stimulation of unplanned purchases, the strategic location of products and duration of each merchandising activity in the store, the digitalization of merchandising and the application of findings from neuroscience studies are some of the most relevant practical applications. Originality/value This study provides the first-ever longitudinal review of the state of the art in merchandising research, taking a holistic perspective of this field of knowledge spanning a 60-year period. The work makes a valuable contribution to the development of the marketing discipline.info:eu-repo/semantics/acceptedVersio

Epidemiology of injuries in professional and amateur spanish paddle players

Se realizó un estudio epidemiológico descriptivo, observacional y retrospectivo, analizando la incidencia y las características de las lesiones sufridas por jugadores de pádel españoles profesionales y no profesionales. Se registraron las lesiones sufridas por 478 jugadores entre el 1 de enero y el 31 de diciembre de 2016. Se registraron datos sobre el número de lesiones, lesiones más frecuentes, distribución, tipo, ubicación, el momento en que ocurrieron y la causa de las lesiones que afectan el sistema locomotor. La tasa de lesiones en esta población fue de 2,75 lesiones por 1000 horas de exposición al riesgo. Las lesiones leves y aquellas con mecanismos de lesión intrínseca fueron las más frecuentes, y tuvieron lugar el final de la práctica deportiva. La extremidad inferior fue el área corporal más lesionada, y el tejido más lesionado fue el sistema musculo-tendinoso. A su vez, la epicondilitis fue la patología más comúnAn epidemiological study was conducted using retrospective, observational and descriptive methodologies. We sought to analyse the incidence and features of injuries sustained by professional and non-professional Spanish Padel players. In total, 478 injuries were registered in 2016 from January 1st to December 31st. We collected data on the number of injuries, the most frequent injuries, their distribution, type, location, the moment at which these occurred and the cause of the injuries affecting the locomotor system. We found that the injury rate in this population was 2.75 injuries per 1000 hours of risk exposure. The most frequent injuries were those which were mild or with mechanisms of intrinsic injury, and most occurred towards the end any given game or practice. The lower limb was the most frequently injured body area, and the most injured tissue was the muscle-tendinous system. In turn, epicondylitis was the most common patholog

A New Algebraization of the Lame Equation

We develop a new way of writing the Lame Hamiltonian in Lie-algebraic form. This yields, in a natural way, an explicit formula for both the Lame polynomials and the classical non-meromorphic Lame functions in terms of Chebyshev polynomials and of a certain family of weakly orthogonal polynomialsComment: Latex2e with AMS-LaTeX and cite packages; 32 page

On the families of orthogonal polynomials associated to the Razavy potential

We show that there are two different families of (weakly) orthogonal polynomials associated to the quasi-exactly solvable Razavy potential V(x)=(\z \cosh 2x-M)^2 (\z>0, $M\in\mathbf N$). One of these families encompasses the four sets of orthogonal polynomials recently found by Khare and Mandal, while the other one is new. These results are extended to the related periodic potential U(x)=-(\z \cos 2x -M)^2, for which we also construct two different families of weakly orthogonal polynomials. We prove that either of these two families yields the ground state (when $M$ is odd) and the lowest lying gaps in the energy spectrum of the latter periodic potential up to and including the $(M-1)^{\rm th}$ gap and having the same parity as $M-1$. Moreover, we show that the algebraic eigenfunctions obtained in this way are the well-known finite solutions of the Whittaker--Hill (or Hill's three-term) periodic differential equation. Thus, the foregoing results provide a Lie-algebraic justification of the fact that the Whittaker--Hill equation (unlike, for instance, Mathieu's equation) admits finite solutions.Comment: Typeset in LaTeX2e using amsmath, amssymb, epic, epsfig, float (24 pages, 1 figure

Simulation of impulse response for indoor visible light communications using 3D CAD models

n this article, a tool for simulating the channel impulse response for indoor visible light communications using 3D computer-aided design (CAD) models is presented. The simulation tool is based on a previous Monte Carlo ray-tracing algorithm for indoor infrared channel estimation, but including wavelength response evaluation. The 3D scene, or the simulation environment, can be defined using any CAD software in which the user specifies, in addition to the setting geometry, the reflection characteristics of the surface materials as well as the structures of the emitters and receivers involved in the simulation. Also, in an effort to improve the computational efficiency, two optimizations are proposed. The first one consists of dividing the setting into cubic regions of equal size, which offers a calculation improvement of approximately 50% compared to not dividing the 3D scene into sub-regions. The second one involves the parallelization of the simulation algorithm, which provides a computational speed-up proportional to the number of processors used

Multiwavelength Photometric and Spectropolarimetric Analysis of the FSRQ 3C 279

In this paper, we present light curves for 3C 279 over a time period of six years; from 2008 to 2014. Our multiwavelength data comprise 1 mm to gamma-rays, with additional optical polarimetry. Based on the behaviour of the gamma-ray light curve with respect to other bands, we identified three different activity periods. One of the activity periods shows anomalous behaviour with no gamma-ray counterpart associated with optical and NIR flares. Another anomalous activity period shows a flare in gamma-rays, 1 mm and polarization degree, however, it does not have counterparts in the UV continuum, optical and NIR bands. We find a significant overall correlation of the UV continuum emission, the optical and NIR bands. This correlation suggests that the NIR to UV continuum is co-spatial. We also find a correlation between the UV continuum and the 1 mm data, which implies that the dominant process in producing the UV continuum is synchrotron emission. The gamma-ray spectral index shows statistically significant variability and an anti-correlation with the gamma-ray luminosity. We demonstrate that the dominant gamma-ray emission mechanism in 3C 279 changes over time. Alternatively, the location of the gamma-ray emission zone itself may change depending on the activity state of the central engine.Comment: 32 pages, 19 figures, Accepted for publication in MNRA

The importance of back contact modification in Cu2ZnSnSe4 solar cells: The role of a thin MoO2 layer

Cu2ZnSn(SxSe1-x)4 (CZTSSe) photovoltaic absorbers could be the earth-abundant and low toxicity replacement for the already commercialized CuIn1-xGaxSe2 (CIGS) thin film technology. In order to make this possible, specific research efforts applied to the bulk, front and back interfaces must be performed with the aim of improving CZTSSe performance. In this paper the importance of back contact modification to obtain high efficiency Cu2ZnSnSe4 (CZTSe) solar cells and to increase a paramount and limiting parameter such as VOC is highlighted. Several Mo configurations (monolayer, bi-layer and tri-layer) with different electrical and morphological properties are investigated in CZTSe solar cells. An optimum tri-layer configuration in order to minimize overselenization of the back contact during thermal annealing while keeping reasonable electrical features is defined. Additionally, a thin intermediate MoO2 layer that results in a very effective barrier against selenization and innovative way to efficiently assist in the CZTSe absorber sintering is introduced. The use of this layer enhances grain growth and subsequently the efficiency of solar cells increases via major VOC and FF improvement. An efficiency increase from 7.2% to 9.5% is obtained using a Mo tri-layer with a 20 nm intermediate MoO2 layerThis research was supported by the Framework 7 program under the project KESTCELLS (FP7-PEOPLE-2012-ITN-316488), by MINECO (Ministerio de Economía y Competitividad de España) under the SUNBEAM project (ENE2013-49136-C4-1-R), and by European Regional Development Founds (ERDF, FEDER Programa Competitivitat de Catalunya 2007–2013). Authors from IREC and the University of Barcelona belong to the M-2E (Electronic Materials for Energy) Consolidated Research Group and the XaRMAE Network of Excellence on Materials for Energy of the “Generalitat de Catalunya”. M.E-R. thanks the MINECO for the FPI-MINECO (BES-2011-045774), Y.S. for the PTA fellowship (PTA2012-7852-A), SG for the FPI fellowship (BES-2014-068533), M.P. for the MINECO postdoctoral fellow (FPDI-2013-18968), E.S. and R.C. for the “Ramon y Cajal” fellowship (RYC-2011-09212) and (RYC-2011-08521) respectively, and H.X. thanks the “China Scholarship Council” fellowship (CSC Nº 201206340113