The importance of particle-support interaction on particle size determination by gas chemisorption.

ABSTRACT: The interaction of the metal-support and particle shape has a key role on the determination of the particle size by gas chemisorption. This paper demonstrates mathematically that, assuming metal particles with hemispherical shapes (a common assumption in this type of characterisation) can provide misleading results of up to one order of magnitude. Thus, the metal particle sizes are underestimated when the metal strongly interacts with the support and overestimated when there is a weak metal-support interaction. Additionally, we also demonstrate that although the assumption of spherical shapes always underestimates the size of particles, this error is considerably lower with regular geometries than that associated to the effect of the metal-support interaction due to their effect on the particle shape. Herein, it is demonstrated the importance of introducing the particle-support interaction factor in the chemisorption particle size determination.The author would like to acknowledge the UK Engineering and Physical Science Research Council (Grant Number EP/L020432/2) for funding.This is the final version of the article. It first appeared from Springer via http://dx.doi.org/10.1007/s11051-016-3385-

Inglaterra en la Guerra de Sucesión española

Treballs Finals de Grau en Història, Facultat de Geografia i Història, Universitat de Barcelona, Curs: 2013-2014, Tutor: Eduardo Escartín SánchezEn mayo de 1702 la reina de Inglaterra, Ana Estuardo, declaró la guerra a Francia y a España y lo mismo hicieron los Estados Generales de las Provincias Unidas y Leopoldo I, emperador del Sacro Imperio Romano Germánico. La guerra era previsible después de que Luís XIV, rey de Francia, aceptara el testamento de Carlos II, rey de la Monarquía Hispánica que había fallecido sin descendencia y que otorgaba el trono español a su nieto, el duque de Anjou. Aunque los tres aliados eran unánimes en la declaración de la guerra, sus motivos eran distintos. El objetivo de este trabajo es estudiar y analizar, a partir de la bibliografía existente, la participación de Inglaterra en esta guerra, partiendo de los antecedentes y tratando de encontrar las causas y los motivos que impulsaron a la monarquía inglesa a intervenir en la contienda para después abandonarla

KamLAND Bounds on Solar Antineutrinos and neutrino transition magnetic moments

We investigate the possibility of detecting solar electron antineutrinos with the KamLAND experiment. These electron antineutrinos are predicted by spin-flavor oscillations at a significant rate even if this mechanism is not the leading solution to the SNP. KamLAND is sensitive to antineutrinos originated from solar ${}^8$B neutrinos. From KamLAND negative results after 145 days of data taking, we obtain model independent limits on the total flux of solar electron antineutrinos $\Phi({}^8 B)< 1.1-3.5\times 10^4 cm^{-2}\ s^{-1}$, more than one order of magnitude smaller than existing limits, and on their appearance probability$P<0.15%$(95antineutrino production by spin-flavor precession, this upper bound implies an upper limit on the product of the intrinsic neutrino magnetic moment and the value of the solar magnetic field$\mu B< 2.3\times 10^{-21}$MeV 95LMA$(\Delta m^2, \tan^2\theta)$values). Limits on neutrino transition moments are also obtained. For realistic values of other astrophysical solar parameters these upper limits would imply that the neutrino magnetic moment is constrained to be, in the most conservative case,$\mu\lsim 3.9\times 10^{-12} \mu_B$(95CL) for a relatively small field$B= 50$kG. For higher values of the magnetic field we obtain:$\mu\lsim 9.0\times 10^{-13} \mu_B$for field$B= 200$kG and$\mu\lsim 2.0\times 10^{-13} \mu_B$for field$B= 1000$ kG at the same statistical significance.Comment: 13 pages, 2 figure

Continuous synthesis of tuneable sized silver nanoparticles: Via a tandem seed-mediated method in coiled flow inverter reactors

Size control of metal nanoparticles is essential to achieve accurate adjustment of their unique chemical and physical properties.</p

H<inf>2</inf> Production via Ammonia Decomposition Using Non-Noble Metal Catalysts: A Review

The wide-spread implementation of the so-called hydrogen economy is currently partially limited by an economically feasible way of storing hydrogen. In this context, ammonia has been commonly presented as a viable option for chemical storage due its high hydrogen content (17.6 wt%). However, its use as an energy carrier requires the development of catalytic systems capable of releasing hydrogen at adequate rates and conditions. At the moment, the most active catalytic systems for the decomposition of ammonia are based on ruthenium, however its cost and scarcity inhibit the wide scale use of these catalysts. This issue has triggered research on the development of alternative catalysts based on more sustainable systems using more readily available, non-noble metals mainly iron, cobalt and nickel as well as a series of transition metal carbides and nitrides and bimetallic systems, which are reviewed herein. There have been some promising cobalt- and nickel-based catalysts reported for the decomposition of ammonia but metal dispersion needs to be increased in order to become more attractive candidates. Conversely, there seems to be less scope for improvement of iron-based catalysts and metal carbides and nitrides. The area with the most potential for improvement is with bimetallic catalysts, particularly those consisting of cobalt and molybdenum.Engineering and Physical Science Research Council (Grant Number EP/L020432/2), SASOL UK Ltd.This is the final version of the article. It first appeared from Springer via http://dx.doi.org/10.1007/s11244-016-0653-

Ammonia decomposition over cobalt/carbon catalysts—Effect of carbon support and electron donating promoter on activity

This paper sets the new design parameters for the development of low temperature ammonia decomposition catalysts based on readily available cobalt as an alternative to scarce but highly active ruthenium-based catalysts. By using a variety of carbon materials as catalytic supports, we systematically demonstrate that microporous supports capable of stabilising small cobalt crystallites (~2 nm) lead to high catalytic activities compared to bigger nanoparticles. Additionally, the degree of graphitisation of the carbon support has a detrimental effect on the activity of the cobalt (0) active sites, likely due to their potential as an electron donator. Consequently, the addition of electron donating promoters such as cesium substantially decreases the activity of the cobalt catalysts. This relationship deviates from the trends observed for ruthenium-based catalysts with an optimum 3–5 nm size where an increase of the graphitisation degree of the support and the addition of electron donating promoters increases the ammonia decomposition activity.The authors would like to acknowledge the UK Engineering and Physical Science Research Council (grant number EP/L020432/2) and the Doctoral Training Centre in the Centre for Sustainable Chemical Technologies at the University of Bath (grant number EP/K016334/1) for funding, and SASOL UK Ltd for supporting TEB’s studentship. We would also like to thank the Research Catalysis Group at Harwell(RCaH)for access to the TEM microscopy facilities.This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.cattod.2016.05.04

Las colecciones de anortositas canadienses del Museu de Geologia de Barcelona y de la Facultat de Geologia de la Universitat de Barcelona

Este trabajo aporta algunas precisiones sobre el origen y características petrográficas de las colecciones gemelas de rocas anortosíticas canadienses del Museu de Geologia de Barcelona y la Facultat de Geologia de la Universitat de Barcelona, así como sobre su idoneidad a efectos museísticos y didácticos. Palabras clave: Canadá, Québec, Anortosita de Langelier, Anortosita de Lac de Saint-Jean, cantera de Alma, petrografia, meta-anortosita, didáctica, colecciones de anortositas, Museu de Geologia, Universitat, Barcelona.This work provides new insights on the origin and petrographic features of the twin collections of canadian anorthositic rocks from Museu de Geologia of Barcelona and Faculty of Geology of University of Barcelona, as well as some considerations on its interest as exhibition and didactic samples. Key words: Canada, Québec, Langelier anorthosite, Lac de Saint-Jean anorthosite, Alma quarry petrography, meta-anorthosite, didactics, anorthosite collections, Museu de Geologia, Universitat, Barcelona.Este trabajo aporta algunas precisiones sobre el origen y características petrográficas de las colecciones gemelas de rocas anortosíticas canadienses del Museu de Geologia de Barcelona y la Facultat de Geologia de la Universitat de Barcelona, así como sobre su idoneidad a efectos museísticos y didácticos. Palabras clave: Canadá, Québec, Anortosita de Langelier, Anortosita de Lac de Saint-Jean, cantera de Alma, petrografia, meta-anortosita, didáctica, colecciones de anortositas, Museu de Geologia, Universitat, Barcelona

Encuesta nacional de tendencias de fitness en España para 2017

Every year for the past 10 years, the American College of Sports Medicine (ACSM) has administered a global survey on fitness trends. This study has reproduced the methodology used by the ACSM surveys with the goal of identifying trends in the fitness sector in Spain. The opinion of 672 professionals in the fitness sector about 40 potential trends in the sector for 2017 were gathered via an online questionnaire. The results are compared and discussed with the results of the international surveys administered by the ACSM from 2007 to 2016. The results show that the trends in the fitness sector in Spain for 2017 largely dovetail with those found in the ACSM’s last international survey for 2016. Thus, 14 of the trends within the Top 20 are identical in both studies, with the top positions being “body weight training”, “high-intensity interval training” and “certified, experienced trained staff”. On the other hand, 4 trends in Spain’s Top 20 were specific to our country. Likewise, 12 of the identified trends match the Top 20 ranked trends in the past decade (2007-2016) devised based on the results of the ACSM’s international surveysDurante los últimos 10 años el Colegio Americano de Medicina del Deporte (American College of Sports Medicine, ACSM) realiza anualmente una encuesta global sobre tendencias de fitness. El presente estudio ha reproducido la metodología empleada en las encuestas de la ACSM y ha tenido como objetivo identificar tendencias en el sector del fitness en el ámbito español. La opinión de 672 profesionales del sector del fitness sobre 40 potenciales tendencias en el sector para el año 2017 se recogió mediante un cuestionario en línea. Los resultados obtenidos se comparan y discuten con los resultados de las encuestas internacionales realizadas por ACSM desde 2007 a 2016. Los resultados muestran que las tendencias en el sector del fitness en España para el año 2017 coinciden, en términos generales, con las encontradas en la última encuesta internacional de la ACSM para el año 2016. Así, 14 de ellas coinciden dentro del Top 20 en ambos estudios, destacando en los primeros lugares “el entrenamiento con peso corporal”, “el entrenamiento interválico de alta intensidad”, y “el personal formado cualificado y experimentado”. Por otro lado, 4 tendencias del Top 20 fueron tendencias específicas de nuestro país. Del mismo modo, 12 tendencias identificadas coinciden con el Top 20 del ranking de las tendencias de la última década (2007-2016) elaborado a partir de los resultados de las encuestas internacionales de la ACS

Enquesta nacional de tendències de fitnes a Espanya per al 2017

Durant els últims 10 anys el Col·legi Americà de Medicina de l’Esport (American College of Sports Medicine, ACSM) realitza anualment una enquesta global sobre tendències de fitnes. El present estudi ha reproduït la metodologia emprada en les enquestes de l’ACSM i ha tingut com a objectiu identificar tendències en el sector del fitnes en l’àmbit espanyol. L’opinió de 672 professionals del sector del fitnes sobre 40 potencials tendències en el sector per a l’any 2017 es va recollir mitjançant un qüestionari en línia. Els resultats obtinguts es comparen i discuteixen amb els resultats de les enquestes internacionals realitzades per ACSM des del 2007 al 2016. Els resultats mostren que les tendències en el sector del fitnes a Espanya per a l’any 2017 coincideixen, en termes generals, amb les oposades en l’última enquesta internacio­nal de l’ACSM per a l’any 2016. Així, 14 d’elles coincideixen dins del Top 20 en tots dos estudis, destacant en els primers llocs “l’entrenament amb pes corporal”, “l’entrenament intervàlic d’alta intensitat”, i “el personal format qualificat i experimentat”. D’altra banda, 4 tendències del Top 20 van ser tendències específiques del nostre país. De la mateixa manera, 12 tendències identificades coincideixen amb el Top 20 del rànquing de les tendències de l’última dècada (2007-2016) elaborat a partir dels resultats de les enquestes internacio­nals de l’ACSM