Total replacement of recycled aggregate and treated wastewater: concrete recycling in extremis

Million tons of construction and demolition waste (CDW) are generated every year around the world, and most of them are not adequately disposed, generating significant pollution on water, soil and air. Additionally, the use of freshwater in industrial processes, such as the production of cement, concrete manufacturing and curing for newly-built structures; has damaged the health of our freshwater ecosystems, reducing their volume and hindering their natural cycle of renovation. Therefore, the incorporation of recycled aggregate (RA) and treated wastewater (TW) as substitutes for the usual aggregates (UA) and freshwater, could generate significant environmental benefits. In this research, a comparative analysis of the experimental results of the properties of fresh and hardened concrete with different replacement percentage of UA for RA, is presented; and as an innovation the use TW. The results show that, regardless of the replacement percentage and use of treated wastewater, a concrete with RA and TW (recycled concrete in extremis, CRiE) had a satisfactory and acceptable or equivalent performance, not differing significantly from the performance of conventional concrete (CC), confirming that the use of RA for concrete building is feasible.Peer ReviewedPostprint (published version

Long distance electron transfer through the aqueous solution between redox partner proteins

Despite the importance of electron transfer between redox proteins in photosynthesis and respiration, the inter-protein electron transfer rate between redox partner proteins has never been measured as a function of their separation in aqueous solution. Here, we use electrochemical tunneling spectroscopy to show that the current between two protein partners decays along more than 10 nm in the solution. Molecular dynamics simulations reveal a reduced ionic density and extended electric field in the volume confined between the proteins. The distance-decay factor and the calculated local barrier for electron transfer are regulated by the electrochemical potential applied to the proteins. Redox partners could use electrochemically gated, long distance electron transfer through the solution in order to conciliate high specificity with weak binding, thus keeping high turnover rates in the crowded environment of cells.España, MINECO BFU2015-71017-P/España, Gobierno de Andalucía (BIO198)Comisión de Universidades e Investigación del Departamento de Innovación, Universidades y Empresa de la Generalitat de Catalunya.(2017 SGR 1442, 2014 SGR 1442, and 2017 SGR 1189

2005-2017 Ozone trends and potential benefits of local measures as deduced from air quality measurements in the north of the Barcelona metropolitan area

We analyzed 2005–2017 data sets on ozone (O3) concentrations in an area (the Vic Plain) frequently affected by the atmospheric plume northward transport of the Barcelona metropolitan area (BMA), the atmospheric basin of Spain recording the highest number of exceedances of the hourly O3 information threshold (180¿µg¿m-3). We aimed at evaluating the potential benefits of implementing local-BMA short-term measures to abate emissions of precursors. To this end, we analyzed in detail spatial and time variations of concentration of O3 and nitrogen oxides (NO and NO2, including OMI remote sensing data for the latter). Subsequently, a sensitivity analysis is done with the air quality (AQ) data to evaluate potential O3 reductions in the north of the BMA on Sundays compared with weekdays as a consequence of the reduction in regional emissions of precursors. The results showed a generalized decreasing trend for regional background O3 as well as the well-known increase in urban O3 and higher urban NO decreasing slopes compared with those of NO2. The most intensive O3 episodes in the Vic Plain are caused by (i) a relatively high regional background O3 (due to a mix of continental, hemispheric–tropospheric and stratospheric contributions); by (ii) intensive surface fumigation from mid-troposphere high O3 upper layers arising from the concatenation of the vertical recirculation of air masses; but also by (iii) an important O3 contribution from the northward transport/channeling of the pollution plume from the BMA. The high relevance of the local-daily O3 contribution during the most intense pollution episodes is clearly supported by the O3 (surface concentration) and NO2 (OMI data) data analysis. A maximum decrease potential (by applying short-term measures to abate emissions of O3 precursors) of 49¿µg¿O3¿m-3 (32¿%) of the average diurnal concentrations was determined. Structurally implemented measures, instead of episodically, could result in important additional O3 decreases because not only the local O3 coming from the BMA plume would be reduced, but also the recirculated O3 and thus the intensity of O3 fumigation in the plain. Therefore, it is highly probable that both structural and episodic measures to abate NOx and volatile organic compound (VOC) emissions in the BMA would result in evident reductions of O3 in the Vic PlainPeer ReviewedPostprint (author's final draft

Discovering Rehabilitation trends in Spain: A bibliometric analysis

The main purpose of this study is to offer an overview of the rehabilitation research area in Spain from 1970 to 2018 through a bibliometric analysis. Analysis of performance and a co-word science mapping analysis were conducted to highlight the topics covered. The software tool SciMAT was used to analyse the themes concerning their performance and impact measures. A total of 3,564 documents from the Web of Science were retrieved. Univ Deusto, Univ Rey Juan Carlos and Basque Foundation for Science are the institutions with highest relative priority. The most important research themes are IntellectualDisability, Neck-Pain and Pain

Subaqueous barchans and plane beds from deposition of quartz silt

The suspension flow of quartz silt (geometric mean grain size of 4.15 µm), in unfavorable conditions for deposition, is the motivation for the development of different bed morphologies. Particles deposit over a plane nonerodible surface and develop well-defined barchan ripples, barchanoids, and plane beds in flume experiments. Bedload transport of quartz silt by bedform migration is several orders of magnitude smaller than the suspended transport. The final bed morphology is controlled by the suspended sediment concentration and running time of the experiment. The average dimensions of the bedforms after 1-day experiments are 4.93 cm wide, 10.33 cm long, and 0.45 cm high. Cohesive plane beds appear after 2-day and 3-day experiments with very high sediment concentrations (= 22.5 kg=m3). Viscous effects are deemed relevant for the formation of the beds.Peer ReviewedPostprint (author's final draft

Influence of Zn excess on compositional, structural and vibrational properties of Cu2ZnSn0.5Ge0.5Se4 thin films and their effect on solar cell efficiency

This Accepted Manuscript will be available for reuse under a CC BY-NC-ND licence after 24 months of embargo periodThe effect of Zn content on compositional, structural and vibrational properties of Cu2ZnSn1-xGexSe4 (CZTGSe, x ~ 0.5) thin films is studied. Kesterite layer is deposited by co-evaporation onto 5 × 5 cm2 Mo/SLG substrate followed by a thermal treatment at maximum temperature of 480 °C, obtaining areas with different composition and morphology which are due to the sample position in the co-evaporation system and to the non-uniform temperature distribution across the substrate. Kesterite layers with higher Zn amounts are characterized by lower Cu and Ge contents; however, a uniform Ge distribution through the absorber layer is detected in all cases. The excess Zn concentration leads to the formation of ZnSe secondary phase on the surface and in the bulk of the absorber as determined by Raman spectroscopy. When higher Ge content and no ZnSe are present in the absorber layer, a compact structure is formed with larger grain size of kesterite. This effect could explain the higher Voc of the solar cell. The Zn content does not affect the bandgap energy significantly (Eg near 1.3 eV), although the observed effect of Zn excess in CZTGSe results in a decreased device performance from 6.4 to 4.2%. This investigation reveals the importance of the control of the off-stoichiometric CZTGSe composition during the deposition process to enhance solar cells propertiesThis work was supported by Spanish Ministry of Science, Innovation and Universities Project WINCOST (ENE2016-80788-C5-2-R) and European Project INFINITE CELL (H2020-MSCA-RISE-2017-777968). ARP also acknowledges financial support from Community of Madrid within Youth Employment Program (PEJD-2017-PRE/IND-4062). MG acknowledges the financial support from ACCIÓ-Generalitat de Catalunya within the TECNIOspring Plus fellowship (TECSPR18-1-0048

Carbon-paste nanocomposites as unconventional gate electrodes for electrolyte-gated organic field-effect transistors: electrical modulation and bio-sensing

Nanocomposite carbon-paste electrodes (NC-CPEs) have been investigated for the first time in electrolytegated organic field-e¿ect transistors (EGOFETs) as a replacement of conventional metal gate electrodes, using carbon nanotubes (CNTs) as a model carbon filler. Interestingly, the electrical properties of the resulting devices have been modulated by changing the loading percentage of CNTs within the insulating polymeric matrix. The potential of using such non-conventional gate electrodes for sensing purposes has also been evaluated by investigating, as a proof of concept, the formation of a supramolecular complex between a functionalized CNT-based NC-CPE containing ß-cyclodextrin (ß-CD) as a bio-recognition element and tryptophan (TRP). This approach, in synergism with the amplification function of an EGOFET, a¿ords a shift in the threshold voltage (VTH) of the transistor, giving promising analytical results with detection limits at picomolar levels (1.0 ± 0.1 pM) as well as a linear response from 10-12 to 10-9 M. Accordingly, NC-CPEs have been demonstrated to be a potential alternative to metal gate electrodes for the development of a new generation of highly sensitive carbon-based EGOFET bio-sensorsPostprint (published version

Assessing spatiotemporal correlations from data for short-term traffic prediction using multi-task learning

Traffic flow prediction is a fundamental problem for efficient transportation control and management. However, most current data-driven traffic prediction work found in the literature have focused on predicting traffic from an individual task perspective, and have not fully leveraged the implicit knowledge present in a road-network through space and time correlations. Such correlations are now far easier to isolate due to the recent profusion of traffic data sources and more specifically their wide geographic spread. In this paper, we take a multi-task learning (MTL) approach whose fundamental aim is to improve the generalization performance by leveraging the domain-specific information contained in related tasks that are jointly learned. In addition, another common factor found in the literature is that a historical dataset is used for the calibration and the assessment of the proposed approach, without dealing in any explicit or implicit way with the frequent challenges found in real-time prediction. In contrast, we adopt a different approach which faces this problem from a point of view of streams of data, and thus the learning procedure is undertaken online, giving greater importance to the most recent data, making data-driven decisions online, and undoing decisions which are no longer optimal. In the experiments presented we achieve a more compact and consistent knowledge in the form of rules automatically extracted from data, while maintaining or even improving, in some cases, the performance over single-task learning (STL).Peer ReviewedPostprint (published version