Diffusion dynamics on multiplex networks

We study the time scales associated to diffusion processes that take place on multiplex networks, i.e. on a set of networks linked through interconnected layers. To this end, we propose the construction of a supra-Laplacian matrix, which consists of a dimensional lifting of the Laplacian matrix of each layer of the multiplex network. We use perturbative analysis to reveal analytically the structure of eigenvectors and eigenvalues of the complete network in terms of the spectral properties of the individual layers. The spectrum of the supra-Laplacian allows us to understand the physics of diffusion-like processes on top of multiplex networks.Comment: 6 Pages including supplemental material. To appear in Physical Review Letter

Dielectric and electrochemical properties of sustainable concrete

It is planned to improve the durability of reinforced concrete structures and the total or partial replacement of their components by the use of recyclable materials; as strategies to contribute to the concrete industry sustainability. The electrical resistivity and its relationship with the microstructure and electrochemical corrosion resistance in reinforced concrete manufactured with sustainable characteristics, that is, with recycled aggregates and supplementary cementitious materials; was evaluated in this study. The electrical resistivity in reinforced concretes is closely related to the microstructure of the cementitious matrix, and with the pore structure and distribution. As a consequence of the their components nature, it is assumed that the proposed sustainable concretes present different microstructure and porosity than the conventional concretes; because of this, the electrical and electrochemical response of those systems was analyzed with the help of the electrochemical impedance spectroscopy technique.Postprint (published version

Hybrid Circuits with Nanofluidic Diodes and Load Capacitors

[EN] The chemical and physical input signals characteristic of micro- and nanofluidic devices operating in ionic solutions should eventually be translated into output electric currents and potentials that are monitored with solid-state components. This crucial step requires the design of hybrid circuits showing robust electrical coupling between ionic solutions and electronic elements. We study experimentally and theoretically the connectivity of the nanofluidic diodes in single-pore and multipore membranes with conventional capacitor systems for the cases of constant, periodic, and white-noise input potentials. The experiments demonstrate the reliable operation of these hybrid circuits over a wide range of membrane resistances, electrical capacitances, and solution pH values. The model simulations are based on empirical equations that have a solid physical basis and provide a convenient description of the electrical circuit operation. The results should contribute to advance signal transduction and processing using nanoporebased biosensors and bioelectronic interfaces.We acknowledge the support from the Ministry of Economic Affairs and Competitiveness and FEDER (Project No. MAT2015-65011-P). M. A., S. N., and W. E. acknowledge the funding from the Hessen State Ministry of Higher Education, Research and the Arts, Germany, under the LOEWE project iNAPO.Ramirez Hoyos, P.; García-Morales, V.; Gómez Lozano, V.; Ali, M.; Nasir, S.; Ensinger, W.; Mafe, S. (2017). Hybrid Circuits with Nanofluidic Diodes and Load Capacitors. Physical Review Applied. 7(6):064035-1-064035-8. https://doi.org/10.1103/PhysRevApplied.7.064035S064035-1064035-876Tagliazucchi, M., & Szleifer, I. (2015). Transport mechanisms in nanopores and nanochannels: can we mimic nature? Materials Today, 18(3), 131-142. doi:10.1016/j.mattod.2014.10.020Liu, Q., Wen, L., Xiao, K., Lu, H., Zhang, Z., Xie, G., … Jiang, L. (2016). A Biomimetic Voltage-Gated Chloride Nanochannel. Advanced Materials, 28(16), 3181-3186. doi:10.1002/adma.201505250Ramirez, P., Cervera, J., Ali, M., Ensinger, W., & Mafe, S. (2014). Logic Functions with Stimuli-Responsive Single Nanopores. ChemElectroChem, 1(4), 698-705. doi:10.1002/celc.201300255Pérez-Mitta, G., Albesa, A. G., Trautmann, C., Toimil-Molares, M. E., & Azzaroni, O. (2017). Bioinspired integrated nanosystems based on solid-state nanopores: «iontronic» transduction of biological, chemical and physical stimuli. Chemical Science, 8(2), 890-913. doi:10.1039/c6sc04255dMisra, N., Martinez, J. A., Huang, S.-C. J., Wang, Y., Stroeve, P., Grigoropoulos, C. P., & Noy, A. (2009). Bioelectronic silicon nanowire devices using functional membrane proteins. Proceedings of the National Academy of Sciences, 106(33), 13780-13784. doi:10.1073/pnas.0904850106Hou, Y., Vidu, R., & Stroeve, P. (2011). Solar Energy Storage Methods. Industrial & Engineering Chemistry Research, 50(15), 8954-8964. doi:10.1021/ie2003413Ramirez, P., Ali, M., Ensinger, W., & Mafe, S. (2012). Information processing with a single multifunctional nanofluidic diode. Applied Physics Letters, 101(13), 133108. doi:10.1063/1.4754845Gomez, V., Ramirez, P., Cervera, J., Nasir, S., Ali, M., Ensinger, W., & Mafe, S. (2015). Charging a Capacitor from an External Fluctuating Potential using a Single Conical Nanopore. Scientific Reports, 5(1). doi:10.1038/srep09501Verdia-Baguena, C., Gomez, V., Cervera, J., Ramirez, P., & Mafe, S. (2017). Energy transduction and signal averaging of fluctuating electric fields by a single protein ion channel. Physical Chemistry Chemical Physics, 19(1), 292-296. doi:10.1039/c6cp06035hYehezkeli, O., Tel-Vered, R., Wasserman, J., Trifonov, A., Michaeli, D., Nechushtai, R., & Willner, I. (2012). Integrated photosystem II-based photo-bioelectrochemical cells. Nature Communications, 3(1). doi:10.1038/ncomms1741Apel, P. (2001). Track etching technique in membrane technology. Radiation Measurements, 34(1-6), 559-566. doi:10.1016/s1350-4487(01)00228-1Ali, M., Ramirez, P., Mafé, S., Neumann, R., & Ensinger, W. (2009). A pH-Tunable Nanofluidic Diode with a Broad Range of Rectifying Properties. ACS Nano, 3(3), 603-608. doi:10.1021/nn900039fCervera, J., Ramirez, P., Gomez, V., Nasir, S., Ali, M., Ensinger, W., … Mafe, S. (2016). Multipore membranes with nanofluidic diodes allowing multifunctional rectification and logical responses. Applied Physics Letters, 108(25), 253701. doi:10.1063/1.4954764Gomez, V., Ramirez, P., Cervera, J., Nasir, S., Ali, M., Ensinger, W., & Mafe, S. (2015). Converting external potential fluctuations into nonzero time-average electric currents using a single nanopore. Applied Physics Letters, 106(7), 073701. doi:10.1063/1.4909532Kalman, E., Healy, K., & Siwy, Z. S. (2007). Tuning ion current rectification in asymmetric nanopores by signal mixing. Europhysics Letters (EPL), 78(2), 28002. doi:10.1209/0295-5075/78/28002Siwy, Z., Kosińska, I. D., Fuliński, A., & Martin, C. R. (2005). Asymmetric Diffusion through Synthetic Nanopores. Physical Review Letters, 94(4). doi:10.1103/physrevlett.94.048102Siwy, Z. S., & Howorka, S. (2010). Engineered voltage-responsive nanopores. Chem. Soc. Rev., 39(3), 1115-1132. doi:10.1039/b909105

Development of Ti–In alloys by powder metallurgy for application as dental biomaterial

Substantial progress has been made in Ti alloys’ properties and chemical composition. However, the effect of porosity and indium content on biocompatibility and corrosion behavior has not been sufficiently studied. Indium (In) is a promising nontoxic element that can replace other toxic elements, while porosity is associated with a good biological response. The purpose of this paper is to evaluate the achievability of three Ti–In alloys with 2.5, 5, and 10 wt.% Indium by powder metallurgy methods as dental prostheses. The findings of the present work showed that In acted as a grain refiner, and allowed us to obtain an 11.2-fold reduction for the Ti–10In sample than for the Ti–2.5In alloy. The total porosity of the Ti–In alloys decreased according to In content, however, grain size and In content showed a greater effect on the mechanical behavior in comparison with the effect of porosity, probably because of the low porosity percentage. All the mechanical values fell within the ranges accepted in the literature for dental implant applications. The Ti3+ and In3+ ion releases were below the toxic concentrations for the human body, with a maximum of 0.43 and 0.016 μg cm−2 h−1, respectively. Corrosion sensitivity decreased with In addition due to its surface protective effect on the Ti-matrix. These results proved that utilizing powder metallurgy methods, Ti–In alloys are feasible candidates for dental prosthesis. Of the three prepared Ti–In alloys, the Ti–10In alloy properties made it the most appropriate Ti–In alloy to be used as a dental implant

Carbonation rate and reinforcing steel corrosion of concretes with recycled concrete aggregates and supplementary cementing materials

Because of the significant environmental impact that the concrete production causes, and as sustainability contribution for this industry; presently some improvements are being implemented in its durability and its components are been replaced for alternative recyclable materials. Concrete carbonation is one of the main causes of reinforcement electrochemical corrosion. Coarse Recycled Concrete Aggregates (RCA) and Supplementary Cementing Materials (SCM) such as fly ash and silica fume were used to produce durable and environmentally friendly concrete and for the evaluation of its carbonation depth and carbonation-induced reinforcement corrosion when it is exposed to accelerated conditions. The depth of carbonation was observed by spraying a phenolphthalein solution on the fresh broken concrete surface. The corrosion rates of steel embedded in these concretes have been measured by the lineal polarization resistance technique. The results indicate that to use RCA and SCM increase the carbonation depth and corrosion current density.Postprint (published version

Quasiperiodic Patterns in Boundary-Modulated Excitable Waves

We investigate the impact of the domain shape on wave propagation in excitable media. Channelled domains with sinusoidal boundaries are considered. Trains of fronts generated periodically at an extreme of the channel are found to adopt a quasiperiodic spatial configuration stroboscopically frozen in time. The phenomenon is studied in a model for the photo-sensitive Belousov-Zabotinsky reaction, but we give a theoretical derivation of the spatial return maps prescribing the height and position of the successive fronts that is valid for arbitrary excitable reaction-diffusion systems.Comment: 4 pages (figures included

High exposure of West Nile virus in equid and wild bird populations in Spain following the epidemic outbreak in 2020

A cross-sectional study was conducted to assess the circulation and risk factors associated with West Nile virus (WNV) exposure in equine and wild bird populations following the largest epidemic outbreak ever reported in Spain. A total of 305 equids and 171 wild birds were sampled between November 2020 and June 2021. IgG antibodies against flaviviruses were detected by blocking enzyme-linked immunosorbent assay (bELISA) in 44.9% (109/243) and 87.1% (54/62) of unvaccinated and vaccinated equids, respectively. The individual seroprevalence in unvaccinated individuals (calculated on animals seropositive by both bELISA and virus microneutralization test [VNT]) was 38.3% (95%CI: 33.1–43.4). No IgM antibodies were detected in animals tested (0/243; 0.0%; 95%CI: 0.0–1.5) by capture-ELISA. The main risk factors associated with WNV exposure in equids were age (adult and geriatric), breed (crossbred) and the absence of a disinsection programme on the facilities. In wild birds, IgG antibodies against flaviviruses were found in 32.7% (56/171; 95%CI: 26.8–38.6) using bELISA, giving an individual WNV seroprevalence of 19.3% (95%CI: 14.3–24.3) after VNT. Seropositivity was found in 37.8% of the 37 species analysed. Species group (raptors), age (>1-year old) and size (large) were the main risk factors related to WNV seropositivity in wild birds. Our results indicate high exposure and widespread distribution of WNV in equid and wild bird populations in Spain after the epidemic outbreak in 2020. The present study highlights the need to continue and improve active surveillance programmes for the detection of WNV in Spain, particularly in those areas at greatest risk of virus circulation

Chiral unitary approach to S-wave meson baryon scattering in the strangeness S=0 sector

We study the S-wave interaction of mesons with baryons in the strangeness S=0 sector in a coupled channel unitary approach. The basic dynamics is drawn from the lowest order meson baryon chiral Lagrangians. Small modifications inspired by models with explicit vector meson exchange in the t-channel are also considered. In addition the pi pi N channel is included and shown to have an important repercussion in the results, particularly in the isospin 3/2 sector.Comment: 23 pages, LaTeX, 21 figure

Propiedades dieléctricas y electroquímicas de concretos sustentables

Como estrategias para contribuir en la sustentabilidad de la industria del concreto se está proyectando mejorar la durabilidad de las estructuras de concreto reforzado y el reemplazo parcial o total de sus ingredientes por materiales reciclables. En este estudio se evaluó la resistividad eléctrica y su relación con la microestructura y resistencia a la corrosión electroquímica de concretos reforzados fabricados con características de sustentabilidad, es decir, con agregados reciclados y materiales cementantes suplementarios. La resistividad eléctrica del concreto está íntimamente relacionada con la microestructura de la matriz cementante y con la estructura y distribución de poros. Por la naturaleza de sus ingredientes, es de suponerse que los concretos sustentables propuestos presentan diferente microestructura y porosidad que el concreto convencional, motivo por el cual se analizó la respuesta eléctrica y electroquímica de dichos sistemas mediante la técnica de espectroscopía de impedancia electroquímica.Peer ReviewedPostprint (published version

The two pion decay of the Roper resonance

We evaluate the two pion decay of the Roper resonance in a model where explicit re-scattering of the two final pions is accounted for by the use of unitarized chiral perturbation theory. Our model does not include an explicit $\epsilon$ or $\sigma$ scalar-isoscalar meson decay mode, instead it generates it dynamically by means of the pion re-scattering. The two ways, explicit or dynamically generated, of introducing this decay channel have very different amplitudes. Nevertheless, through interference with the other terms of the model we are able to reproduce the same phenomenology as models with explicit consideration of the $\epsilon$ meson.Comment: 17 latex pages, 11 eps figures. A few misprints corrected. A few new references. Version accepted for publication in Phys. Rev.