Thermocatalytic CO2 Conversion over a Nickel-Loaded Ceria Nanostructured Catalyst: A NAP-XPS Study

Despite the increasing economic incentives and environmental advantages associated to their substitution, carbon-rich fossil fuels are expected to remain as the dominant worldwide source of energy through at least the next two decades and perhaps later. Therefore, both the control and reduction of CO2 emissions have become environmental issues of major concern and big challenges for the international scientific community. Among the proposed strategies to achieve these goals, conversion of CO2 by its reduction into high added value products, such as methane or syngas, has been widely agreed to be the most attractive from the environmental and economic points of view. In the present work, thermocatalytic reduction of CO2 with H-2 was studied over a nanostructured ceria-supported nickel catalyst. Ceria nanocubes were employed as support, while the nickel phase was supported by means a surfactant-free controlled chemical precipitation method. The resulting nanocatalyst was characterized in terms of its physicochemical properties, with special attention paid to both surface basicity and reducibility. The nanocatalyst was studied during CO2 reduction by means of Near Ambient Pressure X-ray Photoelectron Spectroscopy (NAP-XPS). Two different catalytic behaviors were observed depending on the reaction temperature. At low temperature, with both Ce and Ni in an oxidized state, CH4 formation was observed, whereas at high temperature above 500 degrees C, the reverse water gas shift reaction became dominant, with CO and H2O being the main products. NAP-XPS was revealed as a powerful tool to study the behavior of this nanostructured catalyst under reaction conditions

SIRGAS-CON una red geodésica utilizada en el monitoreo del vapor de agua troposférico sobre Latinoamérica

El sistema Tierra se encuentra en permanente estudio. Diversas ciencias analizan variables específicas que requieren su georreferenciación. La variación del nivel del mar, la tectónica, el monitoreo atmosférico, son ejemplos evidentes de esta necesidad. Se evidencia la demanda de un marco de referencia único, preciso y global. Este ha sido definido por la Unión Internacional de Geodestas y Geofísicos, es el ITRF. En América Latina se materializa, mediante una suma de esfuerzos colaborativos en la red SIRGAS_CON. Con el objeto de optimizar el aprovechamiento de esta red, se ha trabajado en definir, aplicar y validar una metodología que permita el cálculo indirecto del Vapor de Agua Troposférico. Se han presentado avances sobre el marco teórico, la metodología aplicada y la validación del método, sobre la base de la subred SIRGAS-CON-D_SUR procesada por el centro de procesamiento de Mendoza, CIMA. En este trabajo se presentan los avances logrados en los últimos dos años sobre la inclusión y ajuste de los retardos troposféricos estimados por distintos centros de procesamiento, abarcando la totalidad de las estaciones continuas SIRGAS operativas

Monitoreo a tiempo real del contenido de vapor de agua en la troposfera a partir de observaciones GNSS en Latinoamérica

Definir y aplicar una metodología que permita monitorear el Vapor de Agua Troposférico a tiempo real, en los distintos sitios donde se dispone de una estación GNSS continua online en la región, realizando un aporte significativo a las ciencias Atmosféricas

Monitoring of tropospheric water vapor content from GNSS observations of the SIRGAS-CON network

El conocimiento de las variables atmosféricas que inciden sobre la vida en la Tierra es un tema de interés prioritario en el campo de las investigaciones que se desarrollan a nivel mundial. Algunas de ellas resultan cruciales en el estudio del Cambio Global como son la variación del nivel del mar, la tectónica, el monitoreo atmosférico y las series temporales de los distintos factores que muestran cambios en el clima. La medición de estas variables requiere un marco de referencia único, preciso y global. Este ha sido definido por la Unión Internacional de Geodestas y Geofísicos, es el ITRF. En América Latina el marco de referencia global se materia-liza en la red GNSS SIRGAS_CON, la cual no solo permite monitorear la geodinámica sino que también realiza un aporte significativo en el seguimiento de algunas variables atmosféricas tanto de la Ionósfera como de la Troposfera. Este grupo ha realizado en los últimos años un aporte significativo en el cálculo del Vapor de agua troposférico (IWV) teniendo como base los correspondientes valores estimados de retardo cenital sobre las observaciones GNSS en las estaciones continuas operativas en América del Sur, Central y el Caribe

Stellar populations across galaxy bars in the MUSE TIMER project

Stellar populations in barred galaxies save an imprint of the influence of the bar on the host galaxy’s evolution. We present a detailed analysis of star formation histories (SFHs) and chemical enrichment of stellar populations in nine nearby barred galaxies from the TIMER project. We used integral field observations with the MUSE instrument to derive unprecedented spatially resolved maps of stellar ages, metallicities, [Mg/Fe] abundances, and SFHs, as well as Hα as a tracer of ongoing star formation. We find a characteristic V-shaped signature in the SFH that is perpendicular to the bar major axis, which supports the scenario where intermediate-age stars (∼2 − 6 Gyr) are trapped on more elongated orbits shaping a thinner part of the bar, while older stars (> 8 Gyr) are trapped on less elongated orbits shaping a rounder and thicker part of the bar. We compare our data to state-of-the-art cosmological magneto-hydrodynamical simulations of barred galaxies and show that such V-shaped SFHs arise naturally due to the dynamical influence of the bar on stellar populations with different ages and kinematic properties. Additionally, we find an excess of very young stars (< 2 Gyr) on the edges of the bars, predominantly on the leading side, thus confirming typical star formation patterns in bars. Furthermore, mass-weighted age and metallicity gradients are slightly shallower along the bar than in the disc, which is likely due to orbital mixing in the bar. Finally, we find that bars are mostly more metal-rich and less [Mg/Fe]-enhanced than the surrounding discs. We interpret this as a signature that the bar quenches star formation in the inner region of discs, usually referred to as star formation deserts. We discuss these results and their implications on two different scenarios of bar formation and evolution

“Epidemia de neurosis”: la cumbia y los nuevos relatos

El siguiente trabajo pretende repensar a la cumbia argentina como un género musical, que desde su aparición en la escena musical nacional ha sido representativa del sentir popular, transformando su estética mientras era atravesada por diferentes contextos sociales, políticos y económicos del país. De esta manera, los diferentes cambios en la sociedad argentina - podemos afirmar - que han tenido su sonoridad cumbiera y sus propios sujetes poéticos. En este sentido - y a partir de la denominada ―nueva ola feminista‖, reivindicadora de los derechos de las mujeres y de la comunidad LGTBQ+ - nos propusimos analizar la canción ―Epidemia de neurosis‖ junto a su videoclip, de la banda platense de cumbia ―Las Cocas‖, a fin de demostrar que existe en la cumbia la posibilidad de unir forma y contenido con un posicionamiento político, pasando de lo estético a lo político y de lo político a lo estético según las coyunturas que se presenten.Facultad de Arte

Does BCR-ABL transcript type influence the prognosis of patients in chronic myelogenous leukemia chronic phase?

Introduction and objective: In this study, we evaluated the influence of the transcript type on hematological and clinical parameters, as well as the event-free survival of 50 patients in the Chronic myeloid leukemia chronic phase. Methods: We reviewed the medical records of 55 patients with Chronic myeloid leukemia. The eligibility criteria were based on the availability of hematological and clinical baseline data in the medical records. Data on BCR-ABL transcripts were obtained from medical records. Results: Eighteen patients (36%) had the b2a2 transcript, 24 (48%) had b3a2 and 8 (16%) had b2a2/b3a2. The median platelet count for transcripts b2a2, b3a2 and b2a2/b3a2 was 320.65 × 103/L, 396 × 103/L, and 327.05 × 103/L, respectively (p = 0.896). We could not find any differences in relation to the other hematological parameters, when compared to the transcript type. Comparison between spleen and liver size and type of transcript did not differ inside the groups (p = 0.395 and p = 0.647, respectively) and the association between risk scores and transcript type did not show statistical significance (p > 0.05). The 21-month probability for event-free survival was 21%, 48% and 66% for the transcripts b2a2, b3a2 and b2a2/b3a2 respectively (p = 0.226) Conclusion: We conclude that the expression BCR-ABL transcripts have no influence on hematological, clinical and event-free survival parameters of patients in the Chronic myeloid leukemia chronic phase. Keywords: Chronic myeloid leukemia, BCR-ABL, Prognosi

Stellar populations across galaxy bars in the MUSE TIMER project

Stellar populations in barred galaxies save an imprint of the influence of the bar on the host galaxy’s evolution. We present a detailed analysis of star formation histories (SFHs) and chemical enrichment of stellar populations in nine nearby barred galaxies from the TIMER project. We used integral field observations with the MUSE instrument to derive unprecedented spatially resolved maps of stellar ages, metallicities, [Mg/Fe] abundances, and SFHs, as well as Hα as a tracer of ongoing star formation. We find a characteristic V-shaped signature in the SFH that is perpendicular to the bar major axis, which supports the scenario where intermediate-age stars (∼2 − 6 Gyr) are trapped on more elongated orbits shaping a thinner part of the bar, while older stars (> 8 Gyr) are trapped on less elongated orbits shaping a rounder and thicker part of the bar. We compare our data to state-of-the-art cosmological magneto-hydrodynamical simulations of barred galaxies and show that such V-shaped SFHs arise naturally due to the dynamical influence of the bar on stellar populations with different ages and kinematic properties. Additionally, we find an excess of very young stars (< 2 Gyr) on the edges of the bars, predominantly on the leading side, thus confirming typical star formation patterns in bars. Furthermore, mass-weighted age and metallicity gradients are slightly shallower along the bar than in the disc, which is likely due to orbital mixing in the bar. Finally, we find that bars are mostly more metal-rich and less [Mg/Fe]-enhanced than the surrounding discs. We interpret this as a signature that the bar quenches star formation in the inner region of discs, usually referred to as star formation deserts. We discuss these results and their implications on two different scenarios of bar formation and evolution