COVID-BEHAVE dataset: measuring human behaviour during the COVID-19 pandemic

Aiming to illuminate the effects of enforced confinements on people’s lives, this paper presents a novel dataset that measures human behaviour holistically and longitudinally during the COVID-19 outbreak. In particular, we conducted a study during the first wave of the lockdown, where 21 healthy subjects from the Netherlands and Greece participated, collecting multimodal raw and processed data from smartphone sensors, activity trackers, and users’ responses to digital questionnaires. The study lasted more than two months, although the duration of the data collection varies per participant. The data are publicly available and can be used to model human behaviour in a broad sense as the dataset explores physical, social, emotional, and cognitive domains. The dataset offers an exemplary perspective on a given group of people that could be considered to build new models for investigating behaviour changes as a consequence of the lockdown. Importantly, to our knowledge, this is the first dataset combining passive sensing, experience sampling, and virtual assistants to study human behaviour dynamics in a prolonged lockdown situation.European Commission 769553Dutch UT-CTI

A Novel Framework for the Holistic Monitoring and Analysis of Human Behaviour

Recent technological advances have enabled the continuous and unobtrusive monitoring of human behaviour. However, most of the existing studies focus on detecting human behaviour under the limitation of one behavioural aspect, such as physical behaviour and not addressing human behaviour in a broad sense. For this reason, we propose a novel framework that will serve as the principal generator of knowledge on the user’s behaviour. The proposed framework moves beyond the current trends in automatic behaviour analysis by detecting and inferring human behaviour automatically, based on multimodal sensor data. In particular, the framework analyses human behaviour in a holistic approach, focusing on different behavioural aspects at the same time; namely physical, social, emotional and cognitive behaviour. Furthermore, the suggested framework investigates user’s behaviour over different periods, introducing the concept of short-term and long-term behaviours and how these change over time

COVID-BEHAVE dataset:measuring human behaviour during the COVID-19 pandemic

Aiming to illuminate the effects of enforced confinements on people’s lives, this paper presents a novel dataset that measures human behaviour holistically and longitudinally during the COVID-19 outbreak. In particular, we conducted a study during the first wave of the lockdown, where 21 healthy subjects from the Netherlands and Greece participated, collecting multimodal raw and processed data from smartphone sensors, activity trackers, and users’ responses to digital questionnaires. The study lasted more than two months, although the duration of the data collection varies per participant. The data are publicly available and can be used to model human behaviour in a broad sense as the dataset explores physical, social, emotional, and cognitive domains. The dataset offers an exemplary perspective on a given group of people that could be considered to build new models for investigating behaviour changes as a consequence of the lockdown. Importantly, to our knowledge, this is the first dataset combining passive sensing, experience sampling, and virtual assistants to study human behaviour dynamics in a prolonged lockdown situation

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

Effect of fuel thermal pretreament on the electrochemical performance of a direct lignite coal fuel cell

Proceedings of the 20th International Conference on Solid State Ionics SSI-20The impact of fuel heat pretreatment on the performance of a direct carbon fuel cell (DCFC) is investigated by utilizing lignite (LG) coal as feedstock in a solid oxide fuel cell of the type: lignite | Co–CeO2/YSZ/Ag | air. Four LG samples are employed as feedstock: (i) pristine lignite (LG), and differently heat treated LG samples under inert (He) atmosphere at (ii) 200 °C overnight (LG200), (iii) 500 °C for 1 h (LG500) and (iv) 800 °C for 1 h (LG800). The impact of several process parameters, related to cell temperature (700–800 °C), carrier gas type (He or CO2), and molten carbonate infusion into the feedstock on the DCFC performance is additionally explored. The proximate and ultimate analysis of the original and pretreated lignite samples show that upon increasing the heat treatment temperature the carbon content is monotonically increased, whereas the volatile matter, moisture, sulfur and oxygen contents are decreased. In addition, although volatiles are eliminated upon increasing the treatment temperature and as a consequence more ordered carbonaceous structure remained, the heat treatment increases the reactivity of lignite with CO2 due mainly to the increased carbon content. These modifications are reflected on the achieved DCFC performance, which is clearly improved upon increasing the treatment temperature. An inferior cell performance is demonstrated by utilizing inert He instead of reactive CO2 atmosphere, as purging gas in the anode compartment, while carbonate infusion always results in ca. 70–100% increase in power output (15.1 mW cm− 2 at 800 °C). The obtained findings are discussed based also on AC impedance spectroscopy measurements, which revealed the impact of LG physicochemical characteristics and DCFC operating parameters on both ohmic and electrode resistances.The authors would like to acknowledge financial support from the European project “Efficient Conversion of Coal to Electricity — Direct Coal Fuel Cells”, which is funded by the Research Fund for Carbon & Steel (RFCR CT-2011-00004).Peer reviewe

Direct utilization of lignite coal in a Co–CeO2/YSZ/Ag solid oxide fuel cell

The feasibility of employing lignite coal as a fuel in a Direct Carbon Fuel Cell (DCFC) of the type: lignite|Co–CeO2/YSZ/Ag|air is investigated. The impact of several parameters, related to anodic electrode composition (20, 40 and 60 wt.% Co/CeO2), cell temperature (700–800 °C), carrier gas composition (CO2/He mixtures), and total feed flow rate (10–70 cm3/min), was systematically examined. The effect of molten carbonates on DCFC performance was also investigated by employing a eutectic mixture of lithium and potassium carbonates as carbon additives. In the absence of carbonates, the optimum performance (∼10 mW cm−2 at 800 °C), was achieved by employing 20 wt.% Co/CeO2 as anodic electrode and pure CO2 as purging gas. An inferior behavior was demonstrated by utilizing He instead of CO2 atmosphere in anode compartment and by increasing purging gas flow rate. Carbonates infusion into lignite feedstock resulted in a further increase of maximum power density up to 32%. The obtained findings are discussed based also on AC impedance spectroscopy measurements, which revealed the impact of DCFC operating parameters on both ohmic and electrode resistances.The authors would like to acknowledge financial support from the European project “Efficient Conversion of Coal to Electricity – Direct Coal Fuel Cells”, which is funded by the Research Fund for Carbon & Steel (RFCR-CT-2011-00004). In addition the authors are grateful to Prof. V. Stathopoulos and Mr. P. Pandis for conducting the Direct Current Four Point (DC4P) measurements.Peer reviewe

Stabilization of catalyst particles against sintering on oxide supports with high oxygen ion lability exemplified by Ir-catalyzed decomposition of N2O

Iridium nanoparticles deposited on a variety of surfaces exhibited thermal sintering characteristics that were very strongly correlated with the lability of lattice oxygen in the supporting oxide materials. Specifically, the higher the lability of oxygen ions in the support, the greater the resistance of the nanoparticles to sintering in an oxidative environment. Thus with γ-Al2O3 as the support, rapid and extensive sintering occurred. In striking contrast, when supported on gadolinia-ceria and alumina-ceria-zirconia composite, the Ir nanoparticles underwent negligible sintering. In keeping with this trend, the behavior found with yttria-stabilized zirconia was an intermediate between the two extremes. This resistance, or lack of resistance, to sintering is considered in terms of oxygen spillover from support to nanoparticles and discussed with respect to the alternative mechanisms of Ostwald ripening versus nanoparticle diffusion. Activity towards the decomposition of N2O, a reaction that displays pronounced sensitivity to catalyst particle size (large particles more active than small particles), was used to confirm that catalytic behavior was consistent with the independently measured sintering characteristics. It was found that the nanoparticle active phase was Ir oxide, which is metallic, possibly present as a capping layer. Moreover, observed turnover frequencies indicated that catalyst-support interactions were important in the cases of the sinter-resistant systems, an effect that may itself be linked to the phenomena that gave rise to materials with a strong resistance to nanoparticle sintering

A demonstration of multi-party dialogue using virtual coaches:The first council of coaches demonstrator

We demonstrate here the first Technical Demonstrator for Council of Coaches a project that is aiming to deploy a platform for virtual health coaching, and will incorporate computational models of argument and dialogu

Effect of support nature on the cobalt-catalyzed CO2 hydrogenation

CO2 hydrogenation to value added chemicals/fuels has gained considerable interest, in terms of sustainable energy and environmental mitigation. In this regard, the present work aims to investigate the CO2 methanation performance of cobalt-based catalysts supported on different metal oxides (MxOy: CeO2, ZrO2, Gd2O3, ZnO) at low temperatures (200–300 °C) and under atmospheric pressure. Various characterization methods, such as N2 adsorption-desorption at −196 °C, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and temperature-programmed reduction (TPR), were employed to correlate the structural and surface properties of the materials with their catalytic activity. The results revealed a significant impact of support nature on the CO2 hydrogenation performance. The following order, in terms of CH4 yield (YCH4), was recorded at 300 °C: Co/CeO2 (∼96%) > Co/ZnO (∼54%) > Co/G2O3 (∼53%) ∼ Co/ZrO2 (∼53%). On the basis of the characterization results, the superiority of Co/CeO2 catalyst can be mainly ascribed to its enhanced reducibility linked to Co-Ceria interactions. Moreover, Co/CeO2 demonstrated a stable conversion/selectivity performance under subsequent reaction cycles, in contrast to Co/ZnO, which progressively activated under reaction conditions. The latter is related with the modifications induced in elemental chemical states and surface composition of Co/ZnO upon pretreatment in reaction conditions, in contrast to Co/CeO2 sample where a stable surface performance was observedLa hidrogenación de CO 2 a productos químicos/combustibles de valor agregado ha ganado un interés considerable, en términos de energía sostenible y mitigación ambiental. En este sentido, el presente trabajo tiene como objetivo investigar el comportamiento de metanización de CO 2 de catalizadores a base de cobalto soportados sobre diferentes óxidos metálicos (M x O y : CeO 2 , ZrO 2 , Gd 2 O 3 , ZnO) a bajas temperaturas (200– 300 °C) y bajo presión atmosférica. Varios métodos de caracterización, como la adsorción-desorción de N 2 a −196 °C, difracción de rayos X (XRD), espectroscopía de fotoelectrones de rayos X (XPS) y reducción de temperatura programada (TPR), se emplearon para correlacionar las propiedades estructurales y superficiales de los materiales con su actividad catalítica. Los resultados revelaron un impacto significativo de la naturaleza del soporte en el rendimiento de hidrogenación de CO2. El siguiente orden, en términos de producción de CH 4 (Y CH4 ), se registró a 300 °C: Co/CeO 2 (∼96 %) > Co/ZnO (∼54 %) > Co/G 2 O 3 (∼53 %) ∼ Co/ZrO 2 (∼53%). Sobre la base de los resultados de la caracterización, la superioridad de Co/CeO 2El catalizador se puede atribuir principalmente a su mayor capacidad de reducción vinculada a las interacciones de Co-Ceria. Además, Co/CeO 2 demostró un rendimiento de conversión/selectividad estable en los ciclos de reacción posteriores, en contraste con Co/ZnO, que se activó progresivamente en las condiciones de reacción. Esto último está relacionado con las modificaciones inducidas en los estados químicos elementales y la composición superficial de Co/ZnO tras el pretratamiento en condiciones de reacción, en contraste con la muestra de Co/CeO 2 donde se observó un comportamiento superficial establ

Tuning of catalytic activity by thermoelectric materials for carbon dioxide hydrogenation

An innovative use of a thermoelectric material (BiCuSeO) as a support and promoter of catalysis for CO2 hydrogenation is reported here. It is proposed that the capability of thermoelectric materials to shift the Fermi level and work function of a catalyst lead to an exponential increase of catalytic activity for catalyst particles deposited on its surface. Experimental results show that the CO2 conversion and CO selectivity are increased significantly by a thermoelectric Seebeck voltage. This suggests that the thermoelectric effect can not only increase the reaction rate but also change chemical equilibrium, which leads to the change of thermodynamic equilibrium for the conversion of CO2 in its hydrogenation reactions. It is also shown that this thermoelectric promotion of catalysis enables BiCuSeO oxide itself to have a high catalytic activity for CO2 hydrogenation. The generic nature of the mechanism suggests the possibility that many catalytic chemical reactions can be tuned in situ to achieve much higher reaction rates, or at lower temperatures, or have better desired selectivity through changing the backside temperature of the thermoelectric support