A distinct magnetic property of the inner penumbral boundary

A sunspot emanates from a growing pore or protospot. In order to trigger the formation of a penumbra, large inclinations at the outskirts of the protospot are necessary. The penumbra develops and establishes by colonising both umbral areas and granulation. Evidence for a unique stable boundary value for the vertical component of the magnetic field strength, $B^{\rm stable}_{\rm ver}$, was found along the umbra-penumbra boundary of developed sunspots. We use broadband G-band images and spectropolarimetric GFPI/VTT data to study the evolution of and the vertical component of the magnetic field on a forming umbra-penumbra boundary. For comparison with stable sunspots, we also analyse the two maps observed by Hinode/SP on the same spot after the penumbra formed. The vertical component of the magnetic field, $B_{\rm ver}$, at the umbra-penumbra boundary increases during penumbra formation owing to the incursion of the penumbra into umbral areas. After 2.5 hours, the penumbra reaches a stable state as shown by the GFPI data. At this stable stage, the simultaneous Hinode/SP observations show a $B_{\rm ver}$ value comparable to that of umbra-penumbra boundaries of fully fledged sunspots. We confirm that the umbra-penumbra boundary, traditionally defined by an intensity threshold, is also characterised by a distinct canonical magnetic property, namely by $B^{\rm stable}_{\rm ver}$. During the penumbra formation process, the inner penumbra extends into regions where the umbra previously prevailed. Hence, in areas where $B_{\rm ver} < B^{\rm stable}_{\rm ver}$, the magneto-convection mode operating in the umbra turns into a penumbral mode. Eventually, the inner penumbra boundary settles at $B^{\rm stable}_{\rm ver}$, which hints toward the role of $B_{\rm ver}^{\rm stable}$ as inhibitor of the penumbral mode of magneto-convection.Comment: Accepted as a Letter to A&A. Reproduced with permission from Astronomy & Astrophysics, \copyright ES

Las Finanzas: Administracion de la cartera Comercial de la Empresa el Buen Vino S,A en el año 2014

Actualmente en la empresa EL BUEN VINO, S.A. los niveles de venta aumentaron en el último semestre del año 2013 por lo que se requiere analizar la administración de la cartera comercial para determinar la efectividad de las operaciones realizadas a través de herramientas financieras que permitan evaluar los procesos y procedimientos utilizados en el departamento de cartera considerando el aumento en los saldos en la integración de las cuentas. Al efectuar el análisis financiero se aplicaron herramientas de análisis financieros tales como métodos de análisis horizontal y vertical para determinar los aumentos y las disminuciones de importancia relativa en las cuentas que integran los estados financieros. Se implementaron razones financieras que permitió evaluar cada proceso vinculado con la administración de cartera comercial. Al momento de realizar el análisis de antigüedad de saldo se determino el riesgo de cobro que surge de las variaciones en los saldos de las carteras mayores a 30 días. Estos análisis determinaron saldos elevados en la cartera comercial, considerando la incorrecta implementación de estándares de selección de clientes para otorgamiento de créditos y políticas de apoyo a la gestión de cobro. Influyendo la cartera de clientes que poseen condiciones de créditos especiales y conforman las carteras vencidas en la integración de las cuentas por cobrar

Reducing the dimensionality effect in importance sampling simulations

The dimensionality effect is avoided by the use of sufficient statistics in event probability estimators realised by importance sampling. If the system function is not a sufficient statistic, an approach is proposed to reduce the dimensionality effect in the estimators. Simulation results of false-alarm probability estimations, applied to radar detection, confirm a clear concordance with the theoretical result

Mejorar el interés hacia la clase de filosofía, utilizando la tecnología como base didáctica

Apéndice, drive de las evidencias, enlace video sustentaciónEste trabajo de investigación se hace atendiendo una de las problemáticas que se están presentando en el Instituto Técnico Santo Tomas de Aquino de la ciudad de Duitama, que es la falta de interés de los estudiantes hacia las clases de filosofía, buscando con esta investigación contribuir, no solo con mejorar el interés de los estudiantes, sino entablar una relación armoniza entre el mundo que vive el estudiante actualmente y su contexto educativo. Con base en lo anterior, se busca utilizar los dispositivos tecnológicos que hacen parte de la realidad del estudiante, como herramientas en una implementación didáctica en la filosofía, haciendo que los profesores innoven su quehacer docente y los estudiantes se sientas más atraídos a las clases de filosofía. Con esta investigación se busca por medio de una secuencia didáctica, mejorar, innovar, y revolucionar el concepto de clase de filosofía, queriendo fomentar la utilización de estos dispositivos, de una manera en donde el estudiante se sienta a gusto con la clase y el docente tenga las herramientas pedagógicas y didácticas para utilizar.This research work is done in response to one of the problems that are occurring in the Technical Institute Santo Tomas de Aquino in the city of Duitama, which is the lack of interest of students to philosophy classes, seeking with this research to contribute, not only to improve the interest of students, but to establish a harmonious relationship between the world that the student lives today and their educational context. Based on the above, we seek to use technological devices that are part of the student's reality, as tools in a didactic implementation in philosophy, making teachers innovate their teaching and students feel more attracted to philosophy classes. This research seeks to improve, innovate, and revolutionize the concept of philosophy class through a didactic sequence, wanting to encourage the use of these devices, in a way where the student feels comfortable with the class and the teacher has the pedagogical and didactic tools to use

A new invasive weed-feeding species of Polypedilum (Pentapedilum) Kieffer from South Africa (Diptera: Chironomidae, Chironominae)

Polypedilum (Pentapedilum) tuburcinatum Andersen et Bello González sp. n. is described and figured as male, female, pupa and larva based on material collected in the Eastern Cape Province in South Africa, imported into quarantine in Ireland and reared in the laboratory. The species feeds on the aquatic weed Lagarosiphon major (Ridl.) Moss ex Wager and is regarded as a promising candidate agent for biological control of this invasive weedpublishedVersio

A distinct magnetic property of the inner penumbral boundary III. Analysis of simulated sunspots

The analyses of sunspot observations revealed a fundamental magnetic property of the umbral boundary, the invariance of the vertical component of the magnetic field. We aim to analyse the magnetic properties of the umbra-penumbra boundary in simulated sunspots and thus assess their similarity to observed sunspots. Also, we aim to investigate the role of plasma $\beta$ and the ratio of kinetic to magnetic energy in simulated sunspots on the convective motions. We use a set of non-grey simulation runs of sunspots with the MURaM code. These data are used to synthesise the Stokes profiles that are then degraded to the Hinode spectropolarimeter-like observations. Then, the data are treated like real Hinode observations of a sunspot and magnetic properties at the umbral boundaries are determined. Simulations with potential field extrapolation produce a realistic magnetic field configuration on their umbral boundaries. Two simulations with potential field upper boundary, but different subsurface magnetic field structures, differ significantly in the extent of their penumbrae. Increasing the penumbra width by forcing more horizontal magnetic fields at the upper boundary results in magnetic properties that are not consistent with observations. This implies that the size of the penumbra is given by the subsurface structure of the magnetic field. None of the sunspot simulations is consistent with observed properties of the magnetic field and direction of the Evershed flow at the same time. Strong outward directed Evershed flows are only found in setups with artificially enhanced horizontal component of the magnetic field at the top boundary that are not consistent with the observed magnetic field properties at the UP boundary. We want to stress out that the `photospheric' boundary of simulated sunspots is defined by a magnetic field strength of equipartition field value