The Pre-History of the Commentary Tradition : Aristotelianism in the First Century bce. (Prolegomena to a Study of Xenarchus of Seleucia)

Au 1er siècle av. J.-C. Aristote fit l’objet d’une étude textuelle intense. Cette étude mena à terme à une appropriation des outils conceptuels élaborés dans ses écrits. Dans le cas de Xénarchus, les outils pertinents concernèrent la théorie aristotélicienne du mouvement, avec un accent mis sur les concepts de lieu naturel et de mouvement naturel. Xénarchus remania la théorie aristotélicienne du mouvement de manière à rendre superflu le corps céleste simple. Sans nier que certaines de ses opinions doivent être comprises à la lumière des débats de la philosophie hellénistique tardive, je prétends que sa façon de lire présuppose une distanciation par rapport à Aristote qui est caractéristique de la philosophie post-hellénistique.In the first century bce Aristotle was subject to an intense textual study. This study eventually led to the appropriation of the conceptual apparatus developed in his writings. In the case of Xenarchus, the relevant apparatus was Aristotle’s theory of motion, with an emphasis on the concepts of natural place and natural motion. Xenarchus reworked Aristotle’s theory of motion so as to make the celestial simple body expendable. While I do not deny that some of his views are best understood in light of the debates of late Hellenestic philosophy, I contend that his textual engagement presupposes the distance from Aristotle that is characteristic of Post-Hellenistic philosophy

A theory for undercompressive shocks in tears of wine

We revisit the tears of wine problem for thin films in water-ethanol mixtures and present a new model for the climbing dynamics. The new formulation includes a Marangoni stress balanced by both the normal and tangential components of gravity as well as surface tension which lead to distinctly different behavior. The prior literature did not address the wine tears but rather the behavior of the film at earlier stages and the behavior of the meniscus. In the lubrication limit we obtain an equation that is already well-known for rising films in the presence of thermal gradients. Such models can exhibit non-classical shocks that are undercompressive. We present basic theory that allows one to identify the signature of an undercompressive (UC) wave. We observe both compressive and undercompressive waves in new experiments and we argue that, in the case of a pre-coated glass, the famous "wine tears" emerge from a reverse undercompressive shock originating at the meniscus

Probing the catalytic activity of sulfate-derived Pristine and post-treated porous TiO2(101) anatase mesocrystals by the oxidative desulfurization of dibenzothiophenes

Mesocrystals (basically nanostructures showing alignment of nanocrystals well beyond crystal size) are attracting considerable attention for modeling and optimization of functionalities. However, for surface-driven applications (heterogeneous catalysis), only those mesocrystals with excellent textural properties are expected to fulfill their potential. This is especially true for oxidative desulfuration of dibenzothiophenes (hard to desulfurize organosulfur compounds found in fossil fuels). Here, we probe the catalytic activity of anatases for the oxidative desulfuration of dibenzothiophenes under atmospheric pressure and mild temperatures. Specifically, for this study, we have taken advantage of the high stability of the (101) anatase surface to obtain a variety of uniform colloidal mesocrystals (approximately 50 nm) with adequate orientational order and good textural properties (pores around 3-4 nm and surface areas around 200 m2/g). Ultimately, this stability has allowed us to compare the catalytic activity of anatases that expose a high number of aligned single crystal-like surfaces while differing in controllable surface characteristics. Thus, we have established that the type of tetrahedral coordination observed in these anatase mesocrystals is not essential for oxidative desulfuration and that both elimination of sulfates and good textural properties significantly improve the catalytic activity. Furthermore, the most active mesocrystals have been used to model the catalytic reaction in three-(oil-solvent-catalyst) and two-phase (solvent-catalyst) systems. Thus, we have been able to observe that the transfer of DBT from the oil to the solvent phase partially limits the oxidative process and to estimate an apparent activation energy for the oxidative desulfuration reaction of approximately 40 kJ/mol in the two-phase system to avoid mass transfer limitations. Our results clearly establish that (101) anatase mesocrystals with excellent textural properties show adequate stability to withstand several post-treatments without losing their initial mesocrystalline character and therefore could serve as models for catalytic processes different from the one studied here.Fil: Rivoira, Lorena Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigación y Tecnología Química. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación y Tecnología Química; ArgentinaFil: Martinez, Maria Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación en Nanociencia y Nanotecnología; ArgentinaFil: Falcon, Horacio. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación en Nanociencia y Nanotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Beltramone, Andrea Raquel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación en Nanociencia y Nanotecnología; ArgentinaFil: Campos-Martin, Jose M.. Consejo Superior de Investigaciones Científicas; EspañaFil: García Fierro, José Luis. Instituto de Catalisis y Petroleoquimica-csic; EspañaFil: Tartaj, Pedro. Consejo Superior de Investigaciones Científicas. Instituto de Catálisis y Petroleoquímica; Españ

Impacto de estrategias de adquisición de vocabulario en primer año de inglés.

En el contexto de la problemática de la adquisición de vocabulario es pertinentepreguntarse si no existen rutas metodológicas factibles de ser aplicadas sistemáticamente en el aula para mejorar el léxico. Más específicamente, este proyecto, que se llevó a cabo en el año 2017, pretendió demostrar que los alumnos entrenados en el uso de estrategias de aprendizaje mejorarían su competencia léxica, la cual se reflejaría en la incorporación del vocabulario específico de las unidades temáticas enseñadas en clase. Partiendo de la hipótesis que los alumnos que reciban instrucción en el uso de estrategias de aprendizaje demostrarán una capacidad léxica más rica y específica en el empleo de nuevos vocablos, se planteó como objetivo general verificar si la instrucción sistemática en el uso de estrategias de aprendizaje facilitaba la adquisición de vocabulario. El estudio fue de corte cuasi experimental y las variables que se examinaron son la instrucción en las estrategias de aprendizaje de vocabulario (estrategias de memoria y cognitivas) seleccionadas para la ocasión (la variable independiente) y la mejora en la capacidad léxica de losestudiantes (la variable dependiente). La propuesta es repasar el trabajo realizado por el equipo y compartir los resultados y las conclusiones a las que se arribó

CO2‐Brine substitution effects on ultrasonic wave propagation through sandstone with oblique fractures

Seismic monitoring of injected CO2 plumes in fractured storage reservoirs relies on accurate knowledge of the physical mechanisms governing elastic wave propagation, as described by appropriate, validated rock physics models. We measured laboratory ultrasonic velocity and attenuation of P and S waves, and electrical resistivity, of a synthetic fractured sandstone with obliquely aligned (penny‐shaped) fractures, undergoing a brine‐CO2 flow‐through test at simulated reservoir pressure and temperature. Our results show systematic differences in the dependence of velocity and attenuation on fluid saturation between imbibition and drainage episodes, which we attribute to uniform and patchy fluid distributions, respectively, and the relative permeability of CO2 and brine in the rock. This behavior is consistent with predictions from a multifluid rock physics model, facilitating the identification of the dispersive mechanisms associated with wave‐induced fluid flow in fractured systems at seismic scales

Transport properties of saline CO2 storage reservoirs with unconnected fractures from brine-CO2 flow-through tests

CO2 storage in fractured reservoirs may lead to fast CO2 flow through interconnected fracture networks; but the role of isolated fractures on brine-CO2 multiphase flow systems remains unclear. We present the results of a brine-CO2 flow-through experiment in which we assess the change in transport properties of a synthetic sandstone plug (a surrogate of a saline siliciclastic CO2 reservoir) containing non-connected fractures aligned 45° from its axis. The test was performed at 40 MPa of constant hydrostatic confining pressure and ~11 MPa of pore pressure, at room temperature (~19.5 °C), using pure liquid-CO2 and 35 g L−1 NaCl salt solution. The injected CO2-brine volume fraction was increased from 0 to 1 in 0.2 units-steps (drainage). Upon achievement of the maximum CO2 saturation (SCO2 ~0.6), the plug was flushed-back with the original brine (imbibition). During the test, we monitored simultaneously pore pressure, temperature, axial and radial strains, and bulk electrical resistivity. The fractured sample showed lower values of cross- and end-points in the relative permeability curves to CO2 compared to non-fractured samples, from comparable experiments performed at similar pressure and brine salinity conditions, but different temperature. Our results suggest that a non-connected fracture network affects the mobility of the individual phases, favouring the trapping of CO2 in the porous medium and improving the storage efficiency of the reservoir. These evidences show the need of a better understanding of fracture connectivity prior to discard fractured reservoirs as unsuitable geological formations for CO2 storage

2020 NO DEFINE TUS LÍMITES Proyecto de Comunicación para el Desarrollo que responde a los cambios originados por la pandemia COVID-19 en adolescentes de un colegio público de Lima

La presente investigación desarrolla el planteamiento del diagnóstico, el diseño y la aplicación del Trabajo de investigación de Comunicación para el Desarrollo “2020 No Define Tus Límites”. Este trabajo de investigación está enmarcado en el contexto de la crisis sanitaria por el COVID-19, que ha supuesto la toma de medidas preventivas relacionadas al distanciamiento social, causando cambios en las diversas dinámicas sociales y afectando a distintos sectores de la población. En este contexto, la problemática comunicacional que aborda el trabajo de investigación surge del debilitamiento del vínculo de los estudiantes de 5to de secundaria del I.E José Santos Chocano con su entorno cercano, compuesto por sus compañeros, docentes y padres/madres. Los estudiantes constituyen el público objetivo principal del trabajo de investigación. Son adolescentes que se encuentran en una etapa de vida en la que transitan por diferentes cambios y, a esto, se añaden los cambios generados por la pandemia: su estilo de vida, el aislamiento social, la ruptura del contacto físico con sus compañeros del colegio y profesores, el desempleo familiar y la falta de acompañamiento para cumplir sus planes personales y profesionales, que se han visto directamente afectados. De esta manera nace “2020 No Define Tus Límites”, que tiene como principal objetivo comunicacional fortalecer el vínculo comunicativo de los estudiantes con sus compañeros, profesores, padres y madres. Para ello, se potenciarán las habilidades personales en estos actores, tales como la empatía, adaptabilidad, apertura al diálogo y la toma de decisiones, que les permitan, a los adolescentes, adaptarse saludablemente a los cambios en sus planes personales y profesionales producidos por la crisis sanitaria del COVID-19 y, a los padres, madres y profesores, ser el principal apoyo emocional de los estudiantes. Para lograrlo, el trabajo de investigación trabaja con una metodología virtual y audiovisual utilizando herramientas y plataformas digitales con la finalidad de adaptarse al lenguaje utilizado por los adolescentes, así como generar una participación didáctica. Siguiendo el enfoque de la comunicación como relación, el trabajo de investigación busca que el entorno cercano de los estudiantes de 5to de secundaria, compuesto por sus compañeros, profesores y padres, comprendan que se tienen el uno para el otro, reconozcan que transitan por una situación similar de cambios e incertidumbre y, a partir de ese reconocimiento, se conviertan en su principal apoyo emocional, afianzando el vínculo comunicativo entre ellos.This research develops the approach of the diagnosis, design and application of the Communication for Development Project "2020 Don't Define Your Limits". This project is developed in the context of the health emergency of COVID-19, which has involved taking preventive measures related to social distancing, causing changes in the various social dynamics and affecting different sectors of the population. In this context, the communicational problem addressed by the project arises from the weakening of the bond of the fifth senior students of the “I.E José Santos Chocano” with their close environment, made up of their classmates, teachers and parents. Students constitute the main target audience for the project. They are adolescents who are in a stage of life in which they go through different changes. To this, are added the changes generated by the pandemic: their lifestyle, social isolation, the breakdown of physical contact with their schoolmates and teachers, family unemployment and the lack of accompaniment to fulfil their personal and professional plans, which have been directly affected. Furthermore, “2020 Doesn't Define Your Limits”, has as its main communicational objective to strengthen the communicational link between students and their peers, teachers, parents. To do this, personal skills will be promoted in these actors, such as empathy, adaptability, openness to dialogue and decision-making, which will allow adolescents to adapt healthily to changes in their personal and professional plans produced by the health crisis of the COVID-19 and, will allow parents and teachers to be the main emotional support of the students. To achieve this, the project works with a virtual and audiovisual methodology using digital tools and platforms in order to adapt to the language used by adolescents, as well as to generate didactic participation. Following the approach of communication as a relationship, the project seeks that the close environment of the 5th senior students, made up of their classmates, teachers and parents, understand that they have each other, recognize that they are going through a similar situation of changes and uncertainty and, from that recognition, become their main emotional support, strengthening the communication link between them.Trabajo de investigació

Evolución del comportamiento físico químico de los pozos en Termas de Rio Hondo como aporte al diagnóstico de situación actual

En la Provincia de Santiago del Estero, la Ciudad de Termas de Rio Hondo constituye un importante ce ntro urbano turístico invernal. Posee en el subsuelo, aguas termales usadas en balneoterapia con propiedades termomedicinales. La extracción excesiva en época de temporada invernal asociadas al turismo, genera un desfasaje entre las demandas potenciales y la disponibilidad del recurso, alterando el sistema. La geoquímica, provee información sobre la distribución de los elementos químicos y su evolución espacial y temporal en el sistema hídrico, caracterizando el agua de los acuíferos y definiendo problemas ambientales. La metodología, se basó en la selección de resultados de análisis físico-químicos existentes y actuales comparados, respecto a TSD. Las anomalías observadas en la concentración de los iones, respecto a las profundidades de explotación están asociadas a la presión antrópica del sistema.In the province of Santiago del Estero, the City of Termas de Rio Hondo is a major urban center winter resort. It has in the subsurface thermal properties used in balneotherapy termomedicinales. Excessive extraction in times of winter season associated with tourism, generates a potential mismatch between the demands and resource availability, altering the system. The geochemistry, provides information on the distribution of chemical elements and their spatial and temporal evolution in the water system, characterizing water aquifers and defining environmental problems. The methodology was based on the selection of results of physicochemical analysis of existing and current compared with respect to TSD. The anomalies observed in the concentration of ions, with respect to depths of operation are associated with human pressure system.Universidad Nacional de La Plat