Estado y Globalización

Fil: Martínez Caballero, Alfonso. Universidad Nacional de Cuyo. Facultad de Ciencias Políticas y Sociale

Preferential oxidation of CO on a La-Co-Ru perovskite-type oxide catalyst

A Ru-containing perovskite-type oxide La(Co,Ru)O3 of nominal composition LaCo0.8Ru0.2O3 was prepared by ultrasonic spray combustion and tested for the preferential oxidation of CO (PROX). EXAFS indicated that Ru adopted the coordination environment of Co in LaCoO3 while Co was present as LaCoO3 and Co3O4. PROX activity was replaced by CO hydrogenation activity above 250 °C. Short oxidation at 500 °C between temperature programmed reaction ramps did not restore the initial La(Co,Ru)O3 structure but generated a catalyst with improved PROX activity compared to the initial La(Co,Ru)O3. Under reductive PROX conditions the material experienced structural changes that improved its overall catalytic activity only if the catalyst was oxidized after each temperature programmed ramp.Spanish Ministry of Research (Project CTQ2014-60524-R)University of Seville for a scholarship for R.P. and the Swiss National Science Foundation (SNF)(Project nr. 200021_159568

Understanding the differences in catalytic performance for hydrogen production of Ni and Co supported on mesoporous SBA-15

Three mono and bimetallic Nix Co1−x /SBA-15 catalysts (x = 1, 0.5 and 0) with a total metallic content of 10 wt% have been prepared by a deposition–precipitation (DP) method. The catalytic performances on the dry reforming of methane reaction (DRM) have been determined and correlated with their physical and chemical state before and after the catalytic reaction. So, while the nickel monometallic system presents a high activity and stability in the DRM reaction, the Co/SBA-15 catalytic system turns out completely inactive. For its part, the Ni0.5Co0.5/SBA-15 has initially a catalytic performance similar to the Ni/SBA- 15 monometallic system, but rapidly evolving to an inactive system, therefore resembling the behavior of the cobalt-based catalyst. The characterization by TEM and in situ XPS techniques has allowed us to ascribe these differences to the initial state of metallic particles after reduction and their different evolution under reaction conditions. So, while after reduction both nickel containing Nix Co1−x /SBA-15 catalysts (x = 1 and 0.5) present a well dispersed metallic phase, the cobalt monometallic catalyst yields big metallic particles with a heterogeneous distribution of sizes. Additionally, unlike the Ni/SBA-15, the NiCo/SBA-15 system increases during reaction the metallic particle sizes. Besides indicating that the particle size is a major reason determining the catalytic performances, these results suggest that in the Ni–Co system both metals form after reduction a bimetallic phase mainly located inside the mesoporous channels of SBA-15 support. Under DRM reaction conditions, the cobalt is segregated to the surface of the bimetallic particles, which seems to determine the interaction with the support surface SBA-15. This feature gives rise to a much less stable metallic phase which suffers an important sintering process under DRM catalytic conditions. © 2017 Elsevier B.V. All rights reserved. 1. Introduction Supported nickel catalytic systems are currently one of the most important industrial heterogeneous catalysts because its remarkable performance in a number of economically strategic processes [1–5]. Among them, the steam reforming of methane (SRM, CH4 + H2O ↔ 3H2 + CO) can be outlined as the main industrial process for obtaining hydrogen and synthesis gas, used to syn- thesize various important chemicals and fuels [6–9]. Although it is not yet commercially exploited, the dry reforming of methane (DRM, CH4 + CO2 ↔ 2H2 + 2CO) is an especially interesting reac- tion that transforms two of the most harmful greenhouse gases, methane and carbon dioxide, into a mixture of hydrogen and car- bon monoxide [10–12]. Once again, Ni-based catalysts are the most ∗ Corresponding author. E-mail address: [email protected] (A. Caballero). widely tested in the literature for this reforming reaction, even though noble metal based catalysts such as Pt, Ru and Rh are much more performance toward methane conversion. The principal issue comes from the fact that Ni typically undergoes severe deactivation processes, mainly due to coke formation, but also due to sinter- ing of the metallic phase, generating big metallic particles which at the same time, favors the coke formation processes [13–17]. As an alternative to overcome these issues, a number of publications have shown as the use of bimetallic systems, as the combination of nickel and cobalt modified the catalytic performance in steam and dry reforming of methane [18–23]. But, depending on the support or the preparation methods both effects, improvements and wors- ening of the efficiency, have been reported. Main reasons explaining these contradictory findings are probably related with differences in the interaction of metals with support surface, which has been recognized as an essential factor affecting the stability of metal [24–26]. So, a strategy to avoid the growth of metallic particles is the use of special supports, and in particular mesoporous supports.Ministerio Economía y Competitividad de España (MINECO) y fondos FEDER de la Unión Europea-ENE2011-24412 y CTQ2014-60524-

Análisis de los factores determinantes del nivel de innovación en el sector hotelero español. Estudio según variable de segmentación

La investigación que se presenta en este trabajo estudia las relaciones que se producen entre ciertos factores determinantes del Proceso de Dirección Estratégica y la innovación en las organizaciones hoteleras con actividad en nuestro país, así como analiza la influencia del nivel de innovación sobre la ventaja competitiva y los resultados organizativos. El trabajo pretende aportar una serie de contribuciones tanto en el ámbito teórico como en el práctico. En el ámbito teórico, la novedad estriba en presentar las conexiones entre los factores que determinan el Proceso de Dirección Estratégica y su impacto en el nivel de innovación, que aunque presentan puntos de contacto evidentes, hasta el momento no han sido sometidos a un tratamiento integrador por parte de la literatura especializada. Para ello, el enfoque teórico basado en los Recursos y Capacidades constituye un marco teórico influyente y adecuado para entender esta conexión. Empíricamente, el análisis de las interrelaciones estratégicas entre ciertos factores del Modelo de Dirección Estratégica y el grado de innovación, así como su impacto en los resultados empresariales, ayudará a destacar la importancia de tratar la gestión de la innovación como una estrategia en sí misma, y a introducirlas en el modelo de pensamiento estratégico de las cadenas hoteleras con actividad en nuestro país.The research presented in this work in this work bases on the study of the relations which the determining factors of the Process of Strategic Management and Innovation in the hotel organizations in our country, as well as to analyze the influence of the innovation level on the competitive advantage and on the organizational results. Overall, this study aims to provide a range of contributions in both theoretical and practical. In the theoretical, the novelty lies in presenting the connections among the factors that determine the strategic direction process and its impact on the level of innovation, but have obvious points of contact, so far have not been subjected to integrative by the literature. For this, the theoretical approach based on the Resources and Capabilities is an influential and adequate theoretical framework for understanding this connection. Empirically, the analysis of the strategic interrelations between certain factors of the Model of Strategic Management and the degree of innovation, as well as its impact in the enterprise results, will help to emphasize the importance of dealing with the management the innovation like a strategy in itself, and to introduce them in the model of strategic thought of the hotel chains with activity in our country

Influence of Al2O3 reinforcement on precipitation kinetic of Cu-Cr nanocomposite

In this paper, the kinetic of precipitation process in mechanically alloyed Cu-1 wt.% Cr and Cu-1 wt.% Cr/3 wt.% Al2O3 solid solution was compared using differential scanning calorimetry (DSC), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The ageing kinetics in Cu¿Cr and Cu¿Cr/Al2O3 can be described using Johnson¿Mehl¿Avrami (JMA) and Sestak¿Berggren (SB) models, respectively. These different behaviors have been discussed in details. It was found that in presence of Al2O3 reinforcement, the ageing activation energy is decreased and the overall ageing process is accelerated. This behavior is probably due to higher dislocation density previously obtained during ball milling and Al2O3¿Cu interface. TEM observations confirm that Al2O3¿Cu interface and structural defects act as a primary and secondary nucleation sites, respectively.Gobierno de España ENE 2007-67926-C02-0

A reconstructed database of historic bluefin tuna captures in the Gibraltar Strait and Western Mediterranean

This data paper presents a reconstruction of a compilation of a small but consistent database of historical capture records of bluefin tuna (Thunnus thynnus; BFT hereafter) from the Gibraltar Strait and Western Mediterranean (Portugal, Spain and Italy). The compilation come from diverse historical and documentary sources and span the time interval from 1525 to 1936 covering a period of 412 years. There is a total of 3074 datum, which reach up to 67.83% of the total implying a 32.17% of missing data. However, we have only reconstructed the captures for the time interval 1700 1936 and we provide these reconstructions only for this time interval and for 9 out of 11 series due to the scarcity and inhomogeneity of the two oldest capture time series. This reconstructed database provides an invaluable opportunity for fisheries and marine research as well as for multidisciplinary research in climate change. © 2017 The AuthorsJ.M.P.M. was funded by a Basque Government post-doctoral fellowship. A. M. Caballero-Alfonso was funded by the Spanish Ministry of Education, Culture and Sports

Preparation of nanostructured nickel aluminate spinel powder from spent NiO/Al2O3 catalyst by mechano-chemical synthesis

In this paper, the possibility of mechano-chemical synthesis, as a single step process for preparation of nanostructured nickel aluminate spinel powder from NiO/Al2O3 spent catalyst was investigated. Powder samples were characterized in terms of composition, morphology, structure, particle size and surface area using complementary techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), differential thermal analysis (DTA) and volumetric adsorption of nitrogen. It was found that formation of spinel was possible after 60 h of milling with no heat treatment. Additionally, influence of mechanical activation on the heat treatment temperature was discussed. It was observed that heat treatment of 15 h milled sample at 1100 °C is enough to produce nickel aluminate spinel. A product of direct mechanical milling showed higher value of surface area (42.3 m2/g) and smaller crystallite size (12 nm) as compared to the heat treated product.Gobierno de España ENE 2007-67926-C02-0

Perception of the importance of IT security in the Spanish hotel industry

Ante un mundo empresarial cada vez más dependiente de las Tecnologías de la Información y las Comunicaciones (TIC), es conveniente que la seguridad informática tenga un hueco importante en estas empresas para el buen funcionamiento de las mismas. Por este motivo, este artículo analiza esta área pero en el sector hotelero, un sector que hoy día no se puede concebir sin el uso de las TIC. Este estudio analiza la percepción (por parte de las empresas) de la seguridad informática en el sector hotelero español a través de encuesta en 2 periodos, con un horizonte temporal de 10 años, y utilizando como marco comparativo el sector empresarial español en general. Obteniendo como resultados, la mayor concienciación por esta seguridad informática en el sector hotelero a lo largo del tiempo, ya que, en el primer periodo temporal, la diferencia entre este sector y las empresas españolas en general era bastante amplia.In a business world increasingly dependent on Information Technology and Communications (ICT), it is desirable that IT security has an important place in these companies for their operation. For this reason, this paper analyzes this area but in the hotel sector, a sector that today can not be conceived without the use of ICT. This study analyzes the perception (by the companies) of IT security in the Spanish hotel industry through surveys in 2 periods (with a time horizon of 10 years) and using as comparative framework the Spanish business sector in general. Obtaining as a result, the increased awareness for this IT security in the hotel industry across the time, as the difference between this sector and the Spanish business sector in general was quite spacious in the first time period

Structural and chemical reactivity modifications of a cobalt perovskite induced by Sr-substitution. An in situ XAS study

LaCoO3 and La0.5Sr0.5CoO3-δ perovskites have been studied by in situ Co K-edge XAS. Although the partial substitution of La(III) by Sr(II) species induces an important increase in the catalytic oxidation activity and modifies the electronic state of the perovskite, no changes could be detected in the oxidation state of cobalt atoms. So, maintaining the electroneutrality of the perovskite requires the generation of oxygen vacancies in the network. The presence of these vacancies explains that the substituted perovskite is now much more reducible than the original LaCoO3 perovskite. As detected by in situ XAS, after a consecutive reduction and oxidation treatment, the original crystalline structure of the LaCoO3 perovskite is maintained, although in a more disordered state, which is not the case for the Sr doped perovskite. So, the La0.5Sr0.5CoO3-δ perovskite submitted to the same hydrogen reduction treatment produces metallic cobalt, while as determined by in situ XAS spectroscopy the subsequent oxidation treatment yields a Co(III) oxide phase with spinel structure. Surprisingly, no Co(II) species are detected in this new spinel phase.Ministerio de Ciencia y Educación ENE2011-2441

Evolución térmica de la Cuenca de Sabinas NE de México, a partir del estudio de inclusiones fluidas en cuerpos estratoligados

En la cuenca de Sabinas la Orogenia Larámide detonó el flujo de fluidos asociado a las zonas más profundas de la cuenca, iniciándose así la acumulación de yacimientos estratoligados en el Noreste de México, los cuales se acumularon preferencialmente en los bordes de las plataformas que limitan dicha cuenca. Las condiciones de temperatura, composición y presión de los fluidos tran sportadores y mineralizantes han quedado registradas en minerales neoformados como la celestina, barita, fluorita, esfalerita, barita, dolomita y calcita. Por medio de la microtermometría de inclusiones fluidas las temperaturas de fusión final (Tff) en los distintos yacimientos estratoligados de la cuenca de Sabinas indican salinidades bajas a medias y temperaturas de homogeneización (Th) bajas a moderadas. Así las inclusiones fluidas relacionadas con yacimientos estratiformes de cobre se caracterizan por contener un fluido cálcico, presentando una Th = 149° a 152°C y una salinidad promedio de 22 wt.% CaCl 2 . Los mantos de plomo+zinc presentan salinidades entre 7 y 22 wt.% NaCl equiv y Th de 75°C a 225°C; los mantos de barita presentan una salmuera clorurado sódica y cálcica con predominio de esta última en un rango de 1 a 2 wt.% NaCl equiv y de 8 a 24 wt.% CaCl 2 , en un rango de Th entre 50° y 155°C; los cuerpos de celestina presentan salinidades de 1 a 12 wt.% NaCl equiv y Th de 70° a 165°C; los mantos y brechas de fluorita presentan salinidades de 6 a 14 wt.% NaCl equiv y Th de 50° a 159°C, y presentan inclusiones fluidas con hidrocarburos. La relación Cl/Br de las salmueras atrapadas en las inclusiones fluidas muestra una tendencia compatible con la evaporación del agua de mar y un proceso de dilución , muy probablemente debido a la interacción con aguas meteóricas. Por otro lado, las relaciones Cl/Br vs. Na/Cl y Cl/Br vs. K/Cl muestran una fuerte interacción agua/roca. Se concluye que los fluidos con alta salinidad y temperat uras superiores a los 210°C y presurizados (> 400 bars) registran una caída de presión y temperatura, iniciándose la precipitación de cuerpos estratiformes de cobre, barita ± zinc/plomo, celestina y, finalmente, de fluorita. Se determina un enfriamiento desde posiciones depocéntricas en la cuenca hacia los bordes de las plataformas de al menos 100°C, y una caída de presión al menos de 300 bar, con una evidente dilución de la salmuera cálcica inicial debido posiblemente a su interacción con aguas meteóricas.Peer ReviewedPostprint (published version