Direct Observation of the Xenon Physisorption Process in Mesopores by Combining In Situ Anomalous Small Angle X ray Scattering and X ray Absorption Spectroscopy

The morphology and structural changes of confined matter are still far from being understood. This report deals with the development of a novel in situ method based on the combination of anomalous small angle X ray scattering ASAXS and X ray absorption near edge structure XANES spectroscopy to directly probe the evolution of the xenon adsorbate phase in mesoporous silicon during gas adsorption at 165 K. The interface area and size evolution of the confined xenon phase were determined via ASAXS demonstrating that filling and emptying the pores follow two distinct mechanisms. The mass density of the confined xenon was found to decrease prior to pore emptying. XANES analyses showed that Xe exists in two different states when confined in mesopores. This combination of methods provides a smart new tool for the study of nanoconfined matter for catalysis, gas, and energy storage application

Prediction of rehabilitation induced motor recovery after stroke using a multi-dimensional and multi-modal approach

Background: Stroke is a debilitating disease affecting millions of people worldwide. Despite the survival rate has significantly increased over the years, many stroke survivors are left with severe impairments impacting their quality of life. Rehabilitation programs have proved to be successful in improving the recovery process. However, a reliable model of sensorimotor recovery and a clear identification of predictive markers of rehabilitation-induced recovery are still needed. This article introduces the cross-modality protocols designed to investigate the rehabilitation treatment’s effect in a group of stroke survivors. Methods/design: A total of 75 stroke patients, admitted at the IRCCS San Camillo rehabilitation Hospital in Venice (Italy), will be included in this study. Here, we describe the rehabilitation programs, clinical, neuropsychological, and physiological/imaging [including electroencephalography (EEG), transcranial magnetic stimulation (TMS), and magnetic resonance imaging (MRI) techniques] protocols set up for this study. Blood collection for the characterization of predictive biological biomarkers will also be taken. Measures derived from data acquired will be used as candidate predictors of motor recovery. Discussion/summary: The integration of cutting-edge physiological and imaging techniques, with clinical and cognitive assessment, dose of rehabilitation and biological variables will provide a unique opportunity to define a predictive model of recovery in stroke patients. Taken together, the data acquired in this project will help to define a model of rehabilitation induced sensorimotor recovery, with the final aim of developing personalized treatments promoting the greatest chance of recovery of the compromised functions

Vinculaciones humanas e institucionales a través del uso de la energía solar: la Comisaría del Menor y las mini cocinas solares

Este trabajo trata acerca de una experiencia de transferencia de tecnología solar, especialmente apropiada para las actuales circunstancias que viven la región y el país. La misma se inició con la Comisaría del Menor, ubicada a cien metros de la Universidad Nacional de Salta (UNSa). Su finalidad es usar mini cocinas solares como alternativa del empleo de leña o gas para la cocción de alimentos y acercar un nivel científico sencillo a adolescentes con problemas socio-económicos para estimular una veta quizás postergada, pero también como vía de vinculación con menores detenidos en la Comisaría. Actualmente, después de casi tres décadas de existencia de la UNSa, vemos que la universidad está rodeada de asentamientos y barrios pobres, así como la mencionada cárcel de menores, pudiendo ejercer su influencia e impacto social, cultural, socioeconómico y académico más allá de la asistencia de los alumnos a sus aulas o el empleo de sus instalaciones deportivas, sino a través de la concurrencia de sus docentes a los lugares donde son necesitados, a fin de acercar propuestas concretas para la solución de problemas. En este trabajo se muestran estas acciones solidarias.This work describes an experience of solar technology transfer, especially appropriate for current circumstances experienced in the region and the country. It began with the Minority Commissary located a hundred meters in front of UNSa. It is aimed at the use of small solar cookers as an alternative to firewood or bottled gas to cook food; to take basic science to adolescents with socio-economical problems to stimulate a - maybe- hidden vein, but also as a training means for detained minors. After almost three decades of existence, UNSa is enclosed of "asentamientos" and poor districts, as well as the above-mentioned Minors jail. Its influence and social impact are felt not only by cultural, socio-economical and academic attendance of the students in their classrooms or the use of their sport installations, but through the concurrence of their teachers and trained personnel to the places where they are needed, in order to evolve concrete proposals for the solution of problems. In this paper, these solidarity actions are illustrated.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

Vinculaciones humanas e institucionales a través del uso de la energía solar: la Comisaría del Menor y las mini cocinas solares

Este trabajo trata acerca de una experiencia de transferencia de tecnología solar, especialmente apropiada para las actuales circunstancias que viven la región y el país. La misma se inició con la Comisaría del Menor, ubicada a cien metros de la Universidad Nacional de Salta (UNSa). Su finalidad es usar mini cocinas solares como alternativa del empleo de leña o gas para la cocción de alimentos y acercar un nivel científico sencillo a adolescentes con problemas socio-económicos para estimular una veta quizás postergada, pero también como vía de vinculación con menores detenidos en la Comisaría. Actualmente, después de casi tres décadas de existencia de la UNSa, vemos que la universidad está rodeada de asentamientos y barrios pobres, así como la mencionada cárcel de menores, pudiendo ejercer su influencia e impacto social, cultural, socioeconómico y académico más allá de la asistencia de los alumnos a sus aulas o el empleo de sus instalaciones deportivas, sino a través de la concurrencia de sus docentes a los lugares donde son necesitados, a fin de acercar propuestas concretas para la solución de problemas. En este trabajo se muestran estas acciones solidarias.This work describes an experience of solar technology transfer, especially appropriate for current circumstances experienced in the region and the country. It began with the Minority Commissary located a hundred meters in front of UNSa. It is aimed at the use of small solar cookers as an alternative to firewood or bottled gas to cook food; to take basic science to adolescents with socio-economical problems to stimulate a - maybe- hidden vein, but also as a training means for detained minors. After almost three decades of existence, UNSa is enclosed of "asentamientos" and poor districts, as well as the above-mentioned Minors jail. Its influence and social impact are felt not only by cultural, socio-economical and academic attendance of the students in their classrooms or the use of their sport installations, but through the concurrence of their teachers and trained personnel to the places where they are needed, in order to evolve concrete proposals for the solution of problems. In this paper, these solidarity actions are illustrated.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

Vinculaciones humanas e institucionales a través del uso de la energía solar: la Comisaría del Menor y las mini cocinas solares

Este trabajo trata acerca de una experiencia de transferencia de tecnología solar, especialmente apropiada para las actuales circunstancias que viven la región y el país. La misma se inició con la Comisaría del Menor, ubicada a cien metros de la Universidad Nacional de Salta (UNSa). Su finalidad es usar mini cocinas solares como alternativa del empleo de leña o gas para la cocción de alimentos y acercar un nivel científico sencillo a adolescentes con problemas socio-económicos para estimular una veta quizás postergada, pero también como vía de vinculación con menores detenidos en la Comisaría. Actualmente, después de casi tres décadas de existencia de la UNSa, vemos que la universidad está rodeada de asentamientos y barrios pobres, así como la mencionada cárcel de menores, pudiendo ejercer su influencia e impacto social, cultural, socioeconómico y académico más allá de la asistencia de los alumnos a sus aulas o el empleo de sus instalaciones deportivas, sino a través de la concurrencia de sus docentes a los lugares donde son necesitados, a fin de acercar propuestas concretas para la solución de problemas. En este trabajo se muestran estas acciones solidarias.This work describes an experience of solar technology transfer, especially appropriate for current circumstances experienced in the region and the country. It began with the Minority Commissary located a hundred meters in front of UNSa. It is aimed at the use of small solar cookers as an alternative to firewood or bottled gas to cook food; to take basic science to adolescents with socio-economical problems to stimulate a - maybe- hidden vein, but also as a training means for detained minors. After almost three decades of existence, UNSa is enclosed of "asentamientos" and poor districts, as well as the above-mentioned Minors jail. Its influence and social impact are felt not only by cultural, socio-economical and academic attendance of the students in their classrooms or the use of their sport installations, but through the concurrence of their teachers and trained personnel to the places where they are needed, in order to evolve concrete proposals for the solution of problems. In this paper, these solidarity actions are illustrated.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

Synthesis of mesoporous metal oxides and their characterization combining small-angle scattering and gas physisorption methods

Diese Arbeit beschäftigte sich mit der Synthese von mesoporösen Metalloxid-Materialien und deren Charakterisierung durch Kombination von Kleinwinkelstreuung und Physisorption. Der erste Teil beschäftigt sich mit der Herstellung von mesoporösen Silizium- und Titandioxiden durch Templatierung von neuartigen Blockcopolymeren. Da diese Makromoleküle besonders große Mizellen bilden, die als porogenes Agens agieren, ist ihre Nutzung sehr interessant für die potentiellen Anwendungen dieser Materialien in Katalyse, Photovoltaik oder als Sensoren. Das Templatierungverfahren wurde im Detail durch die Änderung des Polymeranteils und die Erzeugung von unterschiedlichen Systemen (dünne Schichte, Pulver, hierarchische Netzwerke) untersucht. Darüber hinaus wurden dünne, mesoporöse TiO2-Schichten als Halbleitern in farbstoffsensibilisierten Solarzellen getestet, und sie zeigten interessante und aussichtsvolle Ergebnisse in Vergleich mit den nanopartikulären TiO2– Schichten. Komplizierte Strukturen wie die hierarchischen, porösen Materialien können nicht im Detail mit Standard-Charakterisierungsmethoden (TEM, SAXS, N2 physisorption) erforscht werden, da wichtige Informationen wie die Zugänglichkeit des porösen Netzwerks und die Verbindung zwischen die Poren unbekannt sind. Solche Fragen konnten durch die Kombination von Kleinwinkelstreuung (SAXS und SANS) und Physisorptions-methoden, nämlich in situ SAXS/SANS-Physisorption, beantwortet werden. Die Verlässlichkeit dieser Methode wurde mit der Charakterisierung der Mikropören als alternativem Weg bezüglich der N2-Physisorption überprüft. Die in-situ SAXS/SANS-Physisorption zeigt mehrfache Anwendungsperspektiven, da man verschiedene Gase bei unterschiedlichen thermodynamischen Konditionen adsorbieren kann. Die Struktur des Netzwerks von zwei ähnlichen mesopörosen Silicas, nämlich PIB-IL und KLE-IL, konnte im Detail geklärt werden durch Verwendung zweier organischer Moleküle, Perfluoropentan und Dibromomethan, die verschiedenen Größen haben. Außerdem wurden die Porosität und die Struktur von periodischen mesoporösen Organosilica-(PMO)-Materialien mit Hilfe von in situ SAXS/SANS-Physisorption untersucht. Solche Materialien haben eine post-synthetische Funktionalisierung mit chiralischen Aminosäure und finden potentielle Anwendungen in der Chromatographie. Die Charakterisierung mit dieser kombinierten Methode erlaubte es, die Zugänglichkeit dieser PMOs und die homogene Verteilung der organischen Teile zu überprüfen

Stability Analysis of Polytopic Discontinuous Galerkin Approximations of the Stokes Problem with Applications to Fluid–Structure Interaction Problems

We present a stability analysis of the Discontinuous Galerkin method on polygonal and polyhedral meshes (PolyDG) for the Stokes problem. In particular, we analyze the discrete inf-sup condition for different choices of the polynomial approximation order of the velocity and pressure approximation spaces. To this aim, we employ a generalized inf-sup condition with a pressure stabilization term. We also prove a priori hp-version error estimates in suitable norms. We numerically check the behaviour of the inf-sup constant and the order of convergence with respect to the mesh configuration, the mesh-size, and the polynomial degree. Finally, as a relevant application of our analysis, we consider the PolyDG approximation for a 2D fluid–structure interaction problem and we numerically explore the stability properties of the method

Alkyl chain grafting on silica-zirconia mixed oxides: preparation and characterization

Silica\u2013zirconia mixed oxide substrates were prepared and grafted with C18 alkyl chains using noctadecyltrichlorosilane. Si : Zr molar ratios in the mixed oxide samples before and after alkyl chain modification were determined by X-ray photoelectron spectroscopy (XPS). Nitrogen sorption measurements provided the porous features of these materials. By means of solid-state 29Si nuclear magnetic resonance (NMR) the amounts of the silanol groups present in the as-prepared, humidified and grafted mixed oxide systems as well as the degree of cross-linking of the silanes were obtained. 13C NMR spectroscopy was used to examine the conformational order of the n-octadecyl chains grafted on the silica\u2013zirconia mixed oxide substrates. Similar information was available from variable temperature Fourier transform infrared (FTIR) investigations. Scanning electron microscopy (SEM) measurements and energy dispersive X-ray (EDX) analyses yielded the morphological features of the solid substrates and information about the distribution of the alkyl chains on the oxide surfaces. The annealing temperature for the preparation of the mixed oxides and the elemental composition of the samples, i.e. relative amount of the oxide components, were found to determine the surface properties and in turn the alkyl chain assembly on the mixed oxide surfaces. FTIR and solid-state 13C NMR data gave evidence for an unusual high conformational order of the grafted C18 alkyl chains in all samples, irrespective of the low surface coverage, which exceeds comparable C18 and C30 grafted silica and metal oxide systems. This finding was attributed to the formation of island structures with aggregated octadecyl chains of high conformational order due to strong intermolecular interactions. Differences in the conformational order of the various samples most likely arise from vertical polymerization which varies with the actual sample

Silica-zirconia mixed oxide samples from silica-based hybrid materials: influence of preparation procedure and composition on the active sites

In this work, the interaction of amorphous silica\u2013zirconia mixed oxide samples obtained from inorganic\u2013 organic silica-based hybrid materials with pyridine and CO2 was studied to investigate their acid/base character. Several silica\u2013zirconia mixed oxide powders characterized by different [Zr/Si] atomic ratios were prepared and treated at increasing temperatures both in a conventional muffle and with microwave technology. The powder samples were characterized with Diffuse Reflectance Infrared Fourier Transform (DRIFT) and X-ray Photoelectron (XP) spectroscopies. The surface acidic and basic active sites were investigated (with DRIFT spectroscopy) by chemisorbing probe molecules (pyridine, carbon dioxide). The obtained results revealed the presence of both Lewis and Br\uf8nsted acidic sites on the amorphous silica\u2013 zirconia mixed oxide powder surfaces. Several acidic sites characterized by different strength were observed; the acidic sites distribution is markedly influenced by the sample composition and by the heat treatment: more numerous acidic sites form on the surface of the samples treated with microwaves with respect to the muffle treated ones; the increment of the temperature and the decrease of the zirconium content cause a significant decrement of the acidic sites. No basic sites were revealed