Apresentação

Apresentaçã

All optical sub diffraction multilevel data encoding onto azo polymeric thin films

By exploiting photo-induced reorientation in azo-polymer thin films, we demonstrate all-optical polarization-encoded information storage with a scanning near-field optical microscope. In the writing routine, 5-level bits are created by associating different bit values to different birefringence directions, induced in the polymer after illumination with linearly polarized light. The reading routine is then performed by implementing polarization-modulation techniques on the same near-field microscope, in order to measure the encoded birefringence direction.Comment: 13 pages, 5 figure

Violencia de género expandida: vigilancia y privacidad en red

In this paper, we present a reflection that links gender violence in digital environments, mass surveillance, discussions about privacy and the right to privacy on the internet. We analyze how the Internet can be the scene of two types of violence: one, located at the level of interactions (doxing, harassment, extortion and threats, identity theft, alteration and publication of photos and videos without consent, among others). The other, more invisible, is implicit in the architecture of the network, because, by promoting a systematic and gigantic system of tracking and analysis of personal data to feed the Internet business model, it has established a potential monitoring system that can affect the rights of women, via digital traces. To support this, we will examine the various notions of surveillance and privacy (Bruno, 2013; Siri, 2015; Sparrow, 2014) and current legislation in order to understand how they affect the human rights of women in cyberspace.Keyword: gender violence, surveillance and privacy, Internet.En este trabajo exponemos una reflexión que enlaza la violencia de género en entornos digitales, la vigilancia masiva, las discusiones sobre la privacidad y el derecho a la intimidad en internet. Analizamos cómo internet puede ser escenario de dos tipos de violencias: una, localizada en el plano de las interacciones (doxing, acoso, extorsión y amenazas, robo de identidad, alteración y publicación de fotos y videos sin consentimiento, entre otras). La otra, más invisible, está implícitaen la arquitectura de la red, pues al propiciar un sistemático y gigantesco sistema de rastreo y análisis de datos personales para alimentar el modelo de negocios de internet, se ha instaurado un potencial sistema de vigilancia que puede afectar los derechos de las mujeres, vía rastros digitales. Para sostener esto examinaremos las diversas nociones de vigilancia y privacidad (Bruno, 2013; Siri, 2015; Sparrow, 2014) y la legislación vigente, en función de comprender cómo afectan los derechos humanos de las mujeres en el ciberespacio. Palabras clave: violencia de género, vigilancia y privacidad, internet

Cuando la nube no es simplemente una metáfora

En las páginas que siguen, proponemos analizar una iniciativa lanzada recientemente por el gobierno argentino, respecto a la creación de una Nube Pública en Gobierno.Facultad de Trabajo Socia

Cuando la nube no es simplemente una metáfora

En las páginas que siguen, proponemos analizar una iniciativa lanzada recientemente por el gobierno argentino, respecto a la creación de una Nube Pública en Gobierno.Facultad de Trabajo Socia

Photoplastic effects in chalcogenide glasses: A review

A synopsis of the various photoinduced changes of rheological, mechanical and elastic properties is presented in the first part of the article. After a critical appraisal of a large body of experimental data it suggested that the photoviscous effect, that is, the athermal decrease of viscosity of a non-crystalline chalcogenide upon illumination is the key for a plethora of photoinduced effects reported so far in the literature under different names. Morphic effects (shape or surface morphology) may ap-pear either in the presence or absence of external mechanical stimuli leading to the fabrication of a variety of technologically important photoprocessed structures. A few representative examples of photoplastic effects are described, in the second part of the paper, in some detail based on information provided by in situ Raman scattering and nanoindentation experiments.Comment: 12 pages, 10 figure

Maten al mensajero : Un análisis sobre los riesgos en la era de Big data

Este trabajo reúne una fusión de visiones teóricas relativas a la actualidad en clave comunicacional, un repaso de la informatización como proceso relevante de la configuración actual, el estudio de algunos casos particulares de espionaje, filtraciones y disputas en torno a la libertad de la red, en todos los casos con la intención de darle cohesión y coherencia a una multiplicidad de hechos y datos que tienden insistentemente a abrumarnos y sobrepasarnos.Facultad de Periodismo y Comunicación Socia

Photoinduced 3D orientational order in side chain liquid crystalline azopolymers

We apply experimental technique based on the combination of methods dealing with principal refractive indices and absorption coefficients to study the photoinduced 3D orientational order in the films of liquid crystalline (LC) azopolymers. The technique is used to identify 3D orientational configurations of trans azobenzene chromophores and to characterize the degree of ordering in terms of order parameters. We study two types of LC azopolymers which form structures with preferred in-plane and out-of-plane alignment of azochromophores, correspondingly. Using irradiation with the polarized light of two different wavelengths we find that the kinetics of photoinduced anisotropy can be dominated by either photo-reorientation or photoselection mechanisms depending on the wavelength. We formulate the phenomenological model describing the kinetics of photoinduced anisotropy in terms of the isomer concentrations and the order parameter tensor. We present the numerical results for absorption coefficients that are found to be in good agreement with the experimental data. The model is also used to interpret the effect of changing the mechanism with the wavelength of the pumping light.Comment: uses revtex4 28 pages, 10 figure

Objetos de aparecer e de desaparecer de Anastacia: diálogos sobre passabilidade trans* e o direito ao manejo dos próprios dados on-line a partir de um estudo de caso

A partir do relato de uma mulher trans* se articulam diálogos acerca da privacidade on-line e as questões trans*, a passabilidade e a autodeterminação nos espaços mediatizados, evidenciando as implicações das tecnologias digitais na produção subjetiva. Chega-se assim a ações de desindexação no entendimento da co-propriedade da informação e da co-gestão dos limites da privacidade

Linearly and circularly polarized laser photoinduced molecular order in azo dye doped polymer films

Photo-induced behavior of Azo Disperse one (AZD1) doped Poly(Methyl MethAcrylate) (PMMA) using both linear and circular polarized light is studied. The anisotropy is not erased by the circular polarization light. The circular polarization light combined with relatively long lifetime of the cis state in azo dye doped polymers activate all transverse directions of the angular hole burning through the spot in the film inducing anisotropy. Under circular polarized light, there is no orientation perpendicularly to the helex described by the rotating electric field vector, trans molecules reorients in the propagation direction of the pump beam. The polarization state of the probe beam after propagation through the pumped spot depends strongly on the angle of incidence of both pump and probe beams on the input face. In the case where circular polarized pump and probe beams are under the same angle of incidence, the probe beam “sees” anisotropic film as if it is isotropic. Results of this work shows the possibility to reorient azobenzene-type molecules in two orthogonal directions using alternately linearly and circularly polarized beams