Basic principles of hp Virtual Elements on quasiuniform meshes

In the present paper we initiate the study of $hp$ Virtual Elements. We focus on the case with uniform polynomial degree across the mesh and derive theoretical convergence estimates that are explicit both in the mesh size $h$ and in the polynomial degree $p$ in the case of finite Sobolev regularity. Exponential convergence is proved in the case of analytic solutions. The theoretical convergence results are validated in numerical experiments. Finally, an initial study on the possible choice of local basis functions is included

Nanoparticle Exsolution from Nanoporous Perovskites for Highly Active and Stable Catalysts

Nanoporosity is clearly beneficial for the performance of heterogeneous catalysts. Although exsolution is a modern method to design innovative catalysts, thus far it is predominantly studied for sintered matrices. A quantitative description of the exsolution of Ni nanoparticles from nanoporous perovskite oxides and their effective application in the biogas dry reforming is here presented. The exsolution process is studied between 500 and 900 °C in nanoporous and sintered La$_{0.52}$Sr$_{0.28}$Ti$_{0.94}$Ni$_{0.06}$O$_{3±δ}$. Using temperature-programmed reduction (TPR) and X-ray absorption spectroscopy (XAS), it is shown that the faster and larger oxygen release in the nanoporous material is responsible for twice as high Ni reduction than in the sintered system. For the nanoporous material, the nanoparticle formation mechanism, studied by in situ TEM and small-angle X-ray scattering (SAXS), follows the classical nucleation theory, while on sintered systems also small endogenous nanoparticles form despite the low Ni concentration. Biogas dry reforming tests demonstrate that nanoporous exsolved catalysts are up to 18 times more active than sintered ones with 90% of CO$_2$ conversion at 800 °C. Time-on-stream tests exhibit superior long-term stability (only 3% activity loss in 8 h) and full regenerability (over three cycles) of the nanoporous exsolved materials in comparison to a commercial Ni/Al$_2$O$_3$ catalyst

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

Biogas dry reforming over Ni/LnOx-type catalysts (Ln = La, Ce, Sm or Pr)

Ni/LnOx-type catalysts (Ln = La, Ce, Sm or Pr, denoted as LNO, CNO, SNO and PNO, respectively) were prepared via a citrate sol-gel method, characterized, and evaluated for the dry reforming of biogas. For the calcined catalysts, the formation of LaNiO3 perovskite crystallites with high purity was observed in the case of La, whereas NiO-LnOx mixed oxides were obtained for the other lanthanides. The reduction treatment led to the formation of medium-sized (∼15 nm) and highly dispersed Ni nanoparticles in LNO following the decomposition of the LaNiO3 perovskite, in contrast to the other catalysts, where bigger Ni crystallites were formed (∼30 nm). As a result, LNO was shown to possess a higher catalytic activity in comparison to the other materials. Regarding the catalytic stability, LNO displayed a considerable activity loss followed by a high pressure drop due to reactor blockage, meaning that the use of Sm (Ni/Sm2O3) can be considered as an alternative strategy to restrict catalyst deactivation. As evidenced by the characterization of the spent catalysts, the deactivation for the most part can be attributed to the extensive coke deposition over the catalysts. The coke deposited was found to be both in the form of more disordered/amorphous carbon, as well as in the form of highly crystalline and multi-walled carbon nanotubes.The authors gratefully acknowledge the Ministry of Science and Technology (MOST) of the People's Republic of China providing funds through the National Key Research and Development Program (project code:2017YFE013330). The authors also gratefully acknowledge that this research has been co-financed by the European Union and Greek national funds under the call “Greece – China Call for Proposals for Joint RT&D Projects” (Project code: T7DKI-00388). V.S. acknowledges the assistance of the Laboratorio de Microscopias Avanzadas-LMA-ICTS ELECMI, Universidad de Zaragoza, Spain. CIBER-BBN is an initiative funded by the VI National R&D&i Plan 2008–2011 financed by the Instituto de Salud Carlos III with the assistance of the European Regional Development Fund.Peer reviewe

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