Increase in visibility of light signals

This work describes a study of perception of light signals used in aeronautics. Devices known as “obstruction light” (L-810 type, according to the Organization of International Civil Aviation OACI and the Federal Aviation Administration FAA) with LED technology were fed with square pulses of voltage, attaining flashes with imperceptible rise times. The lights were presented to observers, simulating the habitual vision conditions for these devices. With this diagram, perceptive comparisons for different flash frequencies were carried out, exploring especially the transition zone between flickering and steady vision of light. The test showed that an important number of people experienced a perceptive increase in such transition zone. The phenomenon, which can be related with to Broca-Sulzer effect, could be used in order to improve the signal visibility

Globular Cluster Scale Sizes in Giant Galaxies: Orbital Anisotropy and Tidally Under-filling Clusters in M87, NGC 1399, and NGC 5128

We investigate the shallow increase in globular cluster half-light radii with projected galactocentric distance $R_{gc}$ observed in the giant galaxies M87, NGC 1399, and NGC 5128. To model the trend in each galaxy, we explore the effects of orbital anisotropy and tidally under-filling clusters. While a strong degeneracy exists between the two parameters, we use kinematic studies to help constrain the distance $R_\beta$ beyond which cluster orbits become anisotropic, as well as the distance $R_{f\alpha}$ beyond which clusters are tidally under-filling. For M87 we find $R_\beta > 27$ kpc and $20 < R_{f\alpha} 13$ kpc and $10 < R_{f\alpha} < 30$ kpc. The connection of $R_{f\alpha}$ with each galaxy's mass profile indicates the relationship between size and $R_{gc}$ may be imposed at formation, with only inner clusters being tidally affected. The best fitted models suggest the dynamical histories of brightest cluster galaxies yield similar present-day distributions of cluster properties. For NGC 5128, the central giant in a small galaxy group, we find $R_\beta > 5$ kpc and $R_{f\alpha} > 30$ kpc. While we cannot rule out a dependence on $R_{gc}$, NGC 5128 is well fitted by a tidally filling cluster population with an isotropic distribution of orbits, suggesting it may have formed via an initial fast accretion phase. Perturbations from the surrounding environment may also affect a galaxy's orbital anisotropy profile, as outer clusters in M87 and NGC 1399 have primarily radial orbits while outer NGC 5128 clusters remain isotropic.Comment: 16 pages, 7 figures, 4 tables, Accepted for publication in MNRA

On Nichols algebras over PGL(2,q) and PSL(2,q)

We compute necessary conditions on Yetter-Drinfeld modules over the groups \mathbf{PGL}(2,q)=\mathbf{PGL}(2,\FF_q) and \mathbf{PSL}(2,q)=\mathbf{PSL}(2,\FF_q) to generate finite dimensional Nichols algebras. This is a first step towards a classification of pointed Hopf algebras with group of group-likes isomorphic to one of these groups. As a by-product of the techniques developed in this work, we prove that there is no non-trivial finite-dimensional pointed Hopf algebra over the Mathieu groups $M_{20}$ and $M_{21}=\mathbf{PSL}(3,4)$.Comment: Minor change

Glare by Light Emitting Diode (LED) vehicle traffic signals

Background: In this paper we analyze devices for traffic signals (traffic lights) with light-emitting diode (LED) technology. Methods: The traditional measurements of luminous intensity were complemented with the luminance analysis of the devices, evaluated for diverse angular fields. Besides, a subjective glare evaluation is presented. In the experience, signals with LEDs directly visible and signals with refractors are compared. Both signals were introduced in the visual field of 30 observers within a perceptive scene that simulated night vision conditions for a driver. The observers were later inquired about the experienced perturbation or discomfort sensation. Results: The obtained results show a significant increase in the punctual luminance as well as an evident perturbation and discomfort for the observers. Conclusions: This effect together with the relatively high degree of coherence of the color lights could result in new kinds of glares not considered in the current standards

Glare by Light Emitting Diode (LED) vehicle traffic signals

Background: In this paper we analyze devices for traffic signals (traffic lights) with light-emitting diode (LED) technology. Methods: The traditional measurements of luminous intensity were complemented with the luminance analysis of the devices, evaluated for diverse angular fields. Besides, a subjective glare evaluation is presented. In the experience, signals with LEDs directly visible and signals with refractors are compared. Both signals were introduced in the visual field of 30 observers within a perceptive scene that simulated night vision conditions for a driver. The observers were later inquired about the experienced perturbation or discomfort sensation. Results: The obtained results show a significant increase in the punctual luminance as well as an evident perturbation and discomfort for the observers. Conclusions: This effect together with the relatively high degree of coherence of the color lights could result in new kinds of glares not considered in the current standards

Introducción del envase Bag in Box para la comercialización de vinos finos en el Mercado Argentino. Una perspectiva de renovación para la industria

La caída en el consumo de vino, es tendencia mundial. En particular, en Argentina, se consumían 54 litros por persona por año en 1990, mientras que hoy, sólo un poco más de 20. Esta situación repercute sobre todas las bebidas alcohólicas, pero afecta en mayor medida al vino, que también ha perdido terreno a favor de sustitutos como la cerveza, los aperitivos y cócteles, que cautivaron al consumidor a fuerza de novedad, menos grados de alcohol y refrescancia. En la actualidad, la industria vitivinícola argentina se enfrenta al desafío de interpretar e internalizar las tendencias del mercado, para evitar que se profundice la pérdida de participación en el consumo interno de bebidas. La demanda pide mejorar el producto desde el sabor, a la vez que está esperando propuestas innovadoras del lado de la presentación: empaques individuales para ciertas ocasiones y de mayor capacidad o familiares para compartir. También pide envases que conserven adecuadamente el producto. En este trabajo, se analiza la posibilidad de introducir definitivamente el vino en caja (bag in box, en inglés, como se conoce al envase en el ámbito industrial) en sus presentaciones de 3 y 5 litros, para el consumo doméstico y de hasta 10 litros para el consumo en hotelería, restauración y catering. Incluye la caracterización del envase -que no es nuevo en el mundo, pero si innovador a nivel local-, la normativa aplicable, y los cálculos de estimación de costos y volúmenes que llevan a concluir la pertinencia y conveniencia de las acciones tendientes a su implementación en el mercado argentino

Estudio de factibilidad de la utilización de cenizas de filtro como adición en hormigones

Práctica Supervisada (IC)--FCEFN-UNC, 2015Realiza un estudio de unas cenizas de filtro originadas en la producción de aluminio secundario. De acuerdo a lo exigido por el Reglamento Argentino de Estructuras de Hormigón CIRSOC 201, se analizaron las características de las mismas y las propiedades que le confieren a morteros y a hormigones al ser incluidas en ellos

"...cuando estás en la acción ya no hay caso...": literatura y revolución en dos cuentos de Germán Rozenmacher

Enmarcada por los estudios de historia intelectual y de las ideas escritos en los últimos años sobre intelectuales y cultura en la década del 60 en la Argentina (Terán 1991); (Sigal 1991), (Rivera 1998) y América Latina (Gilman 2003), nuestra ponencia se propone rescatar la obra del escritor argentino Germán Rozenmacher (1936-1971) para pensar una representación diferente (apartada de las ya canonizadas en las obras de Rodolfo Walsh, Julio Cortázar y, recientemente, Osvaldo Lamborghini) de la revolución en la literatura. Realizaremos un recorrido crítico por dos de los cuentos de Los ojos del tigre (1968) que ponen en primer plano la violencia política y los ideales revolucionarios, "Cochecito" y "Los ojos del tigre", para relevar recursos, motivos y planteos éticomorales. Los temas a tratar en este recorrido son, entre otros: la puesta en escena de la tensión entre los ideales revolucionarios y las relaciones amorosas; la construcción de personajes con un perfil psicólogico denso; el coloquialismo, el monólogo interior y la polifonía como recursos narrativos principales; etc. El análisis intentará detectar cómo Rozenmacher problematizó los movimientos revolucionarios que comenzaban a surgir en los sesenta en la Argentina.Centro de Estudios de Teoría y Crítica Literari

Topological phase transition in a RNA model in the de Gennes regime

We study a simplified model of the RNA molecule proposed by G. Vernizzi, H. Orland and A. Zee in the regime of strong concentration of positive ions in solution. The model considers a flexible chain of equal bases that can pairwise interact with any other one along the chain, while preserving the property of saturation of the interactions. In the regime considered, we observe the emergence of a critical temperature T_c separating two phases that can be characterized by the topology of the predominant configurations: in the large temperature regime, the dominant configurations of the molecule have very large genera (of the order of the size of the molecule), corresponding to a complex topology, whereas in the opposite regime of low temperatures, the dominant configurations are simple and have the topology of a sphere. We determine that this topological phase transition is of first order and provide an analytic expression for T_c. The regime studied for this model exhibits analogies with that for the dense polymer systems studied by de GennesComment: 15 pages, 4 figure

Rare Events and Scale--Invariant Dynamics of Perturbations in Delayed Dynamical Systems

We study the dynamics of perturbations in time delayed dynamical systems. Using a suitable space-time coordinate transformation, we find that the time evolution of the linearized perturbations (Lyapunov vector) can be mapped to the linear Zhang surface growth model [Y.-C. Zhang, J. Phys. France {\bf 51}, 2129 (1990)], which is known to describe surface roughening driven by power-law distributed noise. As a consequence, Lyapunov vector dynamics is dominated by rare random events that lead to non-Gaussian fluctuations and multiscaling properties.Comment: Final version to appear in Phys. Rev. Lett., 4 pages, 3 eps fig