277 research outputs found
Geología en la costa: técnicas de análisis de sedimentos e interpretación de ambientes sedimentarios
Shape effects of ceria nanoparticles on the water-gas shift performance of cuox /ceo2 catalysts
T1EDK-00094 UIDB/EQU/50020/2020 UIDB/00511/2020 CEECINST/00102/2018 UIDB/50006/2020 UIDP/50006/2020 DL 57/2017The copper–ceria (CuOx /CeO2 ) system has been extensively investigated in several catalytic processes, given its distinctive properties and considerable low cost compared to noble metal-based catalysts. The fine-tuning of key parameters, e.g., the particle size and shape of individual counterparts, can significantly affect the physicochemical properties and subsequently the catalytic performance of the binary oxide. To this end, the present work focuses on the morphology effects of ceria nanoparticles, i.e., nanopolyhedra (P), nanocubes (C), and nanorods (R), on the water–gas shift (WGS) performance of CuOx /CeO2 catalysts. Various characterization techniques were employed to unveil the effect of shape on the structural, redox and surface properties. According to the acquired results, the support morphology affects to a different extent the reducibility and mobility of oxygen species, following the trend: R > P > C. This consequently influences copper–ceria interactions and the stabilization of partially reduced copper species (Cu+ ) through the Cu2+ /Cu+ and Ce4+ /Ce3+ redox cycles. Regarding the WGS performance, bare ceria supports exhibit no activity, while the addition of copper to the different ceria nanostructures alters significantly this behaviour. The CuOx /CeO2 sample of rod-like morphology demonstrates the best catalytic activity and stability, approaching the thermodynamic equilibrium conversion at 350◦ C. The greater abundance in loosely bound oxygen species, oxygen vacancies and highly dispersed Cu+ species can be mainly accounted for its superior catalytic performance.publishersversionpublishe
A qualitative methodology to reduce features in classification problems
In this paper, a preliminary methodology which
quantifies the dependence between features in a
data set by using the Ameva discretization algo rithm and the advantages of a qualitative model
is developed. Thus, different matrices of inter dependence are built providing a grade of depen dence between two features. This methodology is
applied to a well-known data set, obtaining promis ing results for the carried out system.Ministerio de Ciencia e Innovacion TIN2009-14378-C02-01 (ARTEMISA
Beyond urban structure and travel pattern. The "mobility environment" as an instrument for planning and evaluation
Resume
Looking at the field of “Urbanística y Ordenación del Territorio” by surveying its academic staff
El área de conocimiento “Urbanística y Ordenación del Territorio” (AUOT) está formada por
un conjunto de profesores y profesoras vinculados en su mayoría a titulaciones universitarias de carácter
tecnológico (ej. arquitectura e ingeniería de caminos). Transcurridos casi cuatro décadas desde
la creación de esta área de conocimiento, el presente artículo muestra un sondeo académico a su
profesorado a partir de una muestra de aproximadamente el 30% del colectivo. Los resultados obtenidos
permiten explorar tendencias del colectivo académico del área de conocimiento, analizando inquietudes
y visiones sobre aspectos docentes, de investigación y de promoción universitaria. Se
reflexiona también sobre elementos claves que pueden ayudar al AUOT a afrontar algunos de los retos
académicos del momento, incluyendo la necesidad de una mayor organización colectiva a nivel estatal.The Spanish knowledge field “Urbanística y Ordenación del Territorio” includes academics
with teaching and research tasks mainly linked to technical degrees (e.g. architecture and civil engineering).
Almost four decades after creating this official knowledge field, this paper presents a survey
to approximately 30% of its teaching staff. The obtained results show a diagnosis and strategic reflection
on the knowledge field, analyzing the academics´ concerns and visions on teaching, research, and
careers expectations. It also discusses some key issues to cope with present academic challenges,
including the need for a better collective coordination at the national level
Essential oils and their application on active packaging systems: a review
The food industry is continuously evolving through the application of innovative tools and ingredients towards more effective, safe, natural and ecofriendly solutions to satisfy the demands of the costumers. In this context, natural sources (i.e., leaves, seeds, peels or unused pulp) can entail a valuable source of compounds, such as essential oils (EOs), with recognized antioxidant and antimicrobial properties that can be used as natural additives in packaging applications. The current trend is the incorporation of EOs into diverse kinds of biodegradable materials, such as edible films, thus developing active packaging systems with improved preservation properties that can offer benefits to both the food and packaging industry by reducing food waste and improving the management of packaging waste. EOs may be added into the packaging material as free or encapsulated molecules, where, especially this last option, has been revealed as very promising. The addition of these lipophilic compounds provides to the end-product various bioactivities of interest, which can eventually extend the shelf-life of the product by preventing food spoilage. Pairing biodegradable packaging with EOs extracted from natural agro-industrial by-products can lead to a more sustainable food industry. Recent knowledge and advances on this issue will be reviewed in the present work.MICINN supporting the Ramón and Cajal grant for M.A. Prieto (RYC-2017-
22891); to EcoChestnut Project for supporting the grant of M. Carpena; to Xunta de Galicia and
University of Vigo for supporting the pre-doctoral grant of P. García-Oliveira (ED481A-2019/295).
The project SYSTEMIC “an integrated approach to the challenge of sustainable food systems: adaptive
and mitigatory strategies to address climate change and malnutrition”, Knowledge hub on Nutrition
and Food Security has received funding from national research funding parties in Belgium (FWO),
France (INRA), Germany (BLE), Italy (MIPAAF), Latvia (IZM), Norway (RCN), Portugal (FCT), and
Spain (AEI) in a joint action of JPI HDHL, JPI-OCEANS and FACCE-JPI launched in 2019 under the
ERA-NET ERA-HDHL (nº 696295).info:eu-repo/semantics/publishedVersio
Synthesis of Pd-Ag alloy membranes and their application in membrane reactors for hydrogen production and purification
Pd-Ag based membranes, self-supported and supported on porous α-Al2O3, have been studied for hydrogen selective separation. In the case of the self-supported membranes the Pd-Ag permeator tube was prepared by cold-rolling and diffusion welding technique; magnetron sputtering technique was employed for the synthesis of the membrane supported on porous α-Al2O3. The results have shown that the self supported Pd-Ag membranes are infinitively H2-selective and the H2-permeation rate through this membrane is in accordance with Sieverts´ law for detect-free meal membranes; hence, an ultra-pure hydrogen stream can be obtained. The Pd-Ag membrane supported on porous α-Al2O3 is not completely selective towards H2, but requires much less metal since it is much thinner (ca. ~50 vs. 1 µm).
In this work, it was studied the water-gas shift on Pd-Ag membrane reactor, but it was also illustrated another application of palladium membranes, in the ethanol steam reforming. The use of the self-supported Pd-Ag membrane leads to enhance the H2 yield in both reactions, providing much better performances than conventional reactors.Patricia Pérez is grateful to Fundação para a Ciência e a Tecnologia (FCT) for the doctoral grant (reference: SFRH/BD/73673/2010). The authors also acknowledge financing from FCT through the project PTDC / EQU -ERQ/098730/2008
Using the new technologies in claudication patients: CReTe: Claudication patients and telematic register
Objetivo: Presentamos una aplicación informática para teléfonos móviles ideada para el control de sesiones
de ejercicio domiciliario en claudicantes. Exponemos también nuestros resultados preliminares.
Material y métodos: La aplicación está dise˜nada para teléfonos móviles con sistema operativo Android,
tecnología de geolocalización y conexión de datos. Está conectada a una base de datos codificada que
preserva el secreto médico. Los datos que se recogen de las sesiones de ejercicio son la fecha, la hora de
inicio y de fin, el tiempo dedicado, el número de las paradas realizadas y la velocidad máxima, la
velocidad media global y la velocidad entre paradas. Durante el mes de enero de 2014 se reclutó a
aquellos pacientes que aceptaran el estudio, poseyeran y entendieran un dispositivo móvil Android con
geolocalización y conexión de datos. Los criterios de exclusión del estudio una vez comenzado fueron
progresión hacia isquemia arterial crítica, enfermedad intercurrente grave, fallecimiento y ausencia de
comunicación con el paciente. Se recogieron las principales morbilidades y los resultados de los
cuestionarios de calidad de vida SF36 y EuroQol 5D. Se midió el tiempo de primera consulta y el tiempo
dedicado por semana y paciente durante un seguimiento de 28 días. Se calculó el cumplimiento de las
sesiones con respecto a las sesiones pactadas con cada paciente, con un mínimo de 2 semanales.
Resultados: Un total de 5 pacientes fueron incluidos, con edad media de 59,3 a˜nos (mediana 52; rango
40-80). De ellos 2 se excluyeron, uno por progresión a isquemia crítica y otro por ausencia de
comunicación. El tiempo medio dedicado por consulta nueva fue de 29,1 min (mediana 27,5; rango
45-20). El cumplimiento de las sesiones fue del 100% en 2 pacientes y del 63% en otro. El tiempo dedicado
en el seguimiento semanal por paciente fue de 1,68 min.
Conclusiones: CReTe es una herramienta aplicable a nuestro medio que precisa de estudios mayores para
demostrar su utilidad.Objective: The preliminary results are presented on the use of a new application for mobile phones designed to control home exercise sessions in claudication.Materials and methods: The application is designed for Android systems with geolocation tech-nology and Internet connection. It is connected to a database encoded to ensure medical confidentiality. The data collected from the exercise sessions were the date, start time and end time, the time spent, the number of stops made, and the maximum speed, average speed and overall speed between stops. During the month of January 2014 patients who accepted and understood the study, and possessed an Android mobile device with geolocation and data connection, were enrolled. The exclusion criteria, 11 the study started, were progression to arterial ischemia, severe intercurrent illness, non-communication with the patient, and death. Major morbidities and results of quality of life questionnaires SF36 and EuroQol 5 D were collec-ted. Time of first consultation and time spent per week per patient during a 28-day follow-up was recorded. Compliance as regards the agreed sessions was calculated for each patient, with a minimum of 2 weeks.Results: The study included 5 patients with a mean age 59.3 years (median 52; range 40-80). Of these, 2 were excluded, one for progression to critical ischemia and another for non-communication. The average time spent in a new consultation was 29.1 minutes (median 27.5, range 45-20). The compliance with the sessions was 100% in 2 patients, and 63% in another. Time spent in the weekly monitoring per patient was 1.68 minutes.Conclusions: CReTe is an applicable tool in our environment that requires further study to demonstrate its usefulness
Bathymetry time series using high spatial resolution satellite images
The use of the new generation of remote sensors, such as echo sounders and Global Navigation Satellite System (GNSS) receivers with di erential correction installed in a drone, allows the acquisition of high-precision data in areas of shallow water, as in the case of the channel of the Encañizadas in the Mar Menor lagoon. This high precision information is the first step to develop the methodology to monitor the bathymetry of the Mar Menor channels. The use of high spatial resolution satellite images is the solution for monitoring many hydrological changes and it is the basis of the three-dimensional (3D) numerical models used to study transport over time, environmental variability, and water ecosystem complexity
- …