Características geomorfológicas y evolución del medio litoral de la zona de Empuries (Girona)

[Resumen] Se aborda la reconstrucción y evolución del entorno físico de la zona próxima al conjunto arqueológico greco-romano de Empuries. La combinación de los datos arqueológicos y geomorfológicos aporta nuevas perspectivas en los dos campos. Al inicio de la colonización la cota se situaba más al interior y presentaba una morfología irregular con acantilados e islotes. Posteriormente se produce una progradación y una regularización de la costa, con un predominio de sedimentos arenosos. Este cambio se interpreta como consecuencia de un descenso del nivel del mar y un cambio del uso del suelo. Esta progradación hacia el E conlleva una movilización de arenas hacia el S, que a su vez puede relacionarse con los desplazamientos de los distintos núcleos de población de Empuries[Abstract] This paper envisages the reconstruction and evolution of the physical environment of the Empurias archeological site and adjoining area. The combination of archeological and geomorphological data provides new insights in both fields. In the early ages of colonization the coast was situated more inland and showed an irregular morphology with cliffs and small islands.The lowereing of the sea and a change of land use caused later coast progradation and regularization with a predominance of sandy sediments. Eastwards progradation is linked to southwards sandy-dune transporte The moving off of different archeological sites in Empuries can be related to the above mentioned sandy-dune transport

Frustrated extended Bose-Hubbard model and deconfined quantum critical points with optical lattices at the anti-magic wavelength

The study of geometrically frustrated many-body quantum systems is of central importance to uncover novel quantum mechanical effects. We design a scheme where ultracold bosons trapped in a one-dimensional state-dependent optical lattice are modeled by a frustrated Bose-Hubbard Hamiltonian. A derivation of the Hamiltonian parameters based on Cesium atoms, further show large tunability of contact and nearest-neighbour interactions. For pure contact repulsion, we discover the presence of two phases peculiar to frustrated quantum magnets: the bond-order-wave insulator with broken inversion symmetry and a chiral superfluid. When the nearest-neighbour repulsion becomes sizeable, a further density-wave insulator with broken translational symmetry can appear. We show that the phase transition between the two spontaneously-symmetry-broken phases is continuous, thus representing a one-dimensional deconfined quantum critical point not captured by the Landau-Ginzburg-Wilson symmetry-breaking paradigm. Our results provide a solid ground to unveil the novel quantum physics induced by the interplay of non-local interactions, geometrical frustration, and quantum fluctuations.Comment: 7+3 pages, 3+3 figure

Nanoscale phase separation and pseudogap in the hole-doped cuprates from fluctuating Cu-O-Cu bonds

The pseudogap phenomenology is one of the enigmas of the physics of high-Tc superconductors. Many members of the cuprate family have now been experimentally characterized with high resolution in both real and momentum space, which revealed highly anisotropic Fermi arcs and local domains which break rotational symmetry in the CuO2 plane at the intraunit cell level. While most theoretical approaches to date have focused on the role of electronic correlations and dopinginduced disorder to explain these features, we show that many features of the pseudogap phase can be reproduced by considering the interplay between electronic and nonlinear electron-phonon interactions within a model of fluctuating Cu-O-Cu bonds. Remarkably, we find that electronic segregation arises naturally without the need to explicitly include disorder. Our approach points not only to the key role played by the oxygen bond in the pseudogap phase, but opens different directions to explore how nonequilibrium lattice excitations can be used to control the properties of the pseudogap phase.This work has been supported by the Spanish Ministry MINECO (National Plan 15 Grant: FISICATEAMO No. FIS2016-79508-P, SEVERO OCHOA No. SEV2015-0522, FPI), European Social Fund, Fundacio Cellex, Generalitat de Catalunya (AGAUR Grant No. 2017 SGR 1341 and CERCA/Program), EU FEDER, ERC AdG OSYRIS and NOQIA, ERC StG SEESUPER, EU FETPRO QUIC, and the National Science Centre, PolandSymfonia Grant No. 2016/20/W/ST4/00314. A.D. was financed by a Juan de la Cierva fellowship (IJCI-2017- 33180). R.W.C. acknowledges funding from the Polish National Center via Miniatura-2 Program Grant No. 2018/02/X/ST3/01718.Peer ReviewedPostprint (author's final draft

Photoelectro-Fenton as post-treatment for electrocoagulated benzophenone-3-loaded synthetic and urban wastewater

The removal of benzophenone-3 (BP-3), a ubiquitous pollutant in municipal wastewater treatment fa-cilities, was optimal by means of a sequential electrocoagulation (EC)/UVA photoelectro-Fenton (PEF)treatment. Overall mineralization was attained upon combination of EC (Fe/Fe cell, 15 mA cm 2, 20 min)with PEF (boron-doped diamond/air-diffusion cell, 33.3 mA cm 2, 720 min), being superior to EC/electro-Fenton (EF) and requiring shorter time than single PEF. In EC, an Al/Al cell yielded the largest removal ofBP-3 in a simulated matrix at pH 11.0 due to precipitation of its neutral form caused by a substantial pHdrop, with optimum current density of 15 mA cm 2. EC of BP-3-loaded urban wastewater at natural pHwas quite effective also with a Fe/Fe cell, being preferred since it provided the required metal catalyst forsubsequent treatment. Among the electrochemical advanced oxidation processes tested, PEF was su-perior to electrochemical oxidation with electrogenerated H2O2(EO-H2O2) and EF, especially when usingthe boron-doped diamond instead of a RuO2-based anode, due to the oxidation of generated activechlorine and hydroxyl radicals, along with the photolytic action of UVA irradiation. GC-MS revealed theformation of 14 cyclic products in PEF treatment, two of them being also formed during EC

Modulation of the electroluminescence emission from ZnO/Si NCs/p-Si light-emitting devices via pulsed excitation

In this work, the electroluminescence (EL) emission of zinc oxide (ZnO)/Si nanocrystals (NCs)-based light-emitting devices was studied under pulsed electrical excitation. Both Si NCs and deep-level ZnO defects were found to contribute to the observed EL. Symmetric square voltage pulses (50-μs period) were found to notably enhance EL emission by about one order of magnitude. In addition, the control of the pulse parameters (accumulation and inversion times) was found to modify the emission lineshape, long inversion times (i.e., short accumulation times) suppressing ZnO defects contribution. The EL results were discussed in terms of the recombination dynamics taking place within the ZnO/Si NCs heterostructure, suggesting the excitation mechanism of the luminescent centers via a combination of electron impact, bipolar injection, and sequential carrier injection within their respective conduction regimes

Classification of brain tumours from MR spectra: the INTERPRET collaboration and its outcomes.

The INTERPRET project was a multicentre European collaboration, carried out from 2000 to 2002, which developed a decision-support system (DSS) for helping neuroradiologists with no experience of MRS to utilize spectroscopic data for the diagnosis and grading of human brain tumours. INTERPRET gathered a large collection of MR spectra of brain tumours and pseudo-tumoural lesions from seven centres. Consensus acquisition protocols, a standard processing pipeline and strict methods for quality control of the aquired data were put in place. Particular emphasis was placed on ensuring the diagnostic certainty of each case, for which all cases were evaluated by a clinical data validation committee. One outcome of the project is a database of 304 fully validated spectra from brain tumours, pseudotumoural lesions and normal brains, along with their associated images and clinical data, which remains available to the scientific and medical community. The second is the INTERPRET DSS, which has continued to be developed and clinically evaluated since the project ended. We also review here the results of the post-INTERPRET period. We evaluate the results of the studies with the INTERPRET database by other consortia or research groups. A summary of the clinical evaluations that have been performed on the post-INTERPRET DSS versions is also presented. Several have shown that diagnostic certainty can be improved for certain tumour types when the INTERPRET DSS is used in conjunction with conventional radiological image interpretation. About 30 papers concerned with the INTERPRET single-voxel dataset have so far been published. We discuss stengths and weaknesses of the DSS and the lessons learned. Finally we speculate on how the INTERPRET concept might be carried into the future.Funding from project MARESCAN (SAF2011-23870) from Ministerio de Economia y Competitividad in Spain. This work was also partially funded by CIBER-BBN, which is an initiative of the VI National R&D&i Plan 2008-2011, CIBER Actions and financed by the Instituto de Salud Carlos III with assistance from the European Regional Development Fund. JRG acknowledges support from Cancer Research UK, the University of Cambridge and Hutchison Whampoa Ltd.This is the author accepted manuscript. The final version is available from Wiley via http://dx.doi.org/10.1002/nbm.343