218 research outputs found

    El furtivismo arqueológico. Consideraciones legales y científicas sobre los hallazgos arqueológicos

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    El problema de las actuaciones arqueológicas incontroladas realizadas por no profesionales es un fenómeno social que viene desde antiguo. La proliferación de estos ‘’aficionados’’ a la Arqueología que buscan, recogen, se guardan y a menudo venden objetos arqueológicos es uno de los principales obstáculos con el que nos encontramos los arqueólogos a la hora de reconstruir los modos de vida de nuestros antepasado

    Low molecular weight ϵ-caprolactone-pcoumaric acid copolymers as potential biomaterials for skin regeneration applications

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    ϵ-caprolactone-p-coumaric acid copolymers at different mole ratios (ϵ-caprolactone:p-coumaric acid 1:0, 10:1, 8:1, 6:1, 4:1, and 2:1) were synthesized by melt-polycondensation and using 4-dodecylbenzene sulfonic acid as catalyst. Chemical analysis by NMR and GPC showed that copolyesters were formed with decreasing molecular weight as p-coumaric acid content was increased. Physical characteristics, such as thermal and mechanical properties, as well as water uptake and water permeability, depended on the mole fraction of pcoumaric acid. The p-coumarate repetitive units increased the antioxidant capacity of the copolymers, showing antibacterial activity against the common pathogen Escherichia coli. In addition, all the synthesized copolyesters, except the one with the highest concentration of the phenolic acid, were cytocompatible and hemocompatible, thus becoming potentially useful for skin regeneration applications

    Nuevas citas de Pilularia minuta Durieu (Marsileaceae) en Sevilla, Andalucía Occidental

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    New records of Pilularia minuta Durieui (Marsileaceae) in Sevilla, western AndalusiaPalabras clave. Pilularia, Marsileaceae, Península Ibérica, Andalucía.Key words. Pilularia, Marsilea, Iberian Peninsula, Andalusia

    Photometric type Ia supernova surveys in narrow band filters

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    We study the characteristics of a narrow band type Ia supernova survey through simulations based on the upcoming Javalambre Physics of the accelerating universe Astrophysical Survey (J-PAS). This unique survey has the capabilities of obtaining distances, redshifts, and the SN type from a single experiment thereby circumventing the challenges faced by the resource-intensive spectroscopic follow-up observations. We analyse the flux measurements signal-to-noise ratio and bias, the supernova typing performance, the ability to recover light curve parameters given by the SALT2 model, the photometric redshift precision from type Ia supernova light curves and the effects of systematic errors on the data. We show that such a survey is not only feasible but may yield large type Ia supernova samples (up to 250 supernovae at z<0.5z<0.5 per month of search) with low core collapse contamination (1.5\sim 1.5 per cent), good precision on the SALT2 parameters (average σmB=0.063\sigma_{m_B}=0.063, σx1=0.47\sigma_{x_1}=0.47 and σc=0.040\sigma_c=0.040) and on the distance modulus (average σμ=0.16\sigma_{\mu}=0.16, assuming an intrinsic scatter σint=0.14\sigma_{\mathrm{int}}=0.14), with identified systematic uncertainties σsys0.10σstat\sigma_{\mathrm{sys}}\lesssim 0.10 \sigma_{\mathrm{stat}}. Moreover, the filters are narrow enough to detect most spectral features and obtain excellent photometric redshift precision of σz=0.005\sigma_z=0.005, apart from \sim 2 per cent of outliers. We also present a few strategies for optimising the survey's outcome. Together with the detailed host galaxy information, narrow band surveys can be very valuable for the study of supernova rates, spectral feature relations, intrinsic colour variations and correlations between supernova and host galaxy properties, all of which are important information for supernova cosmological applications.Comment: 20 pages, 12 tables and 26 figures. Version accepted by MNRAS, with results slightly different from previous on

    Investigating the spin-orbit interaction in van der Waals heterostructures by means of the spin relaxation anisotropy

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    Graphene offers long spin propagation and, at the same time, a versatile platform to engineer its physical properties. Proximity-induced phenomena, taking advantage of materials with large spin-orbit coupling or that are magnetic, can be used to imprint graphene with large spin-orbit coupling and magnetic correlations. However, full understanding of the proximitized graphene and the consequences on the spin transport dynamics requires the development of unconventional experimental approaches. The investigation of the spin relaxation anisotropy, defined as the ratio of lifetimes for spins pointing out of and in the graphene plane, is an important step in this direction. This review discusses various methods for extracting the spin relaxation anisotropy in graphene-based devices. Within the experimental framework, current understanding on spin transport dynamics in single-layer and bilayer graphene is presented. Due to increasing interest, experimental results in graphene in proximity with high spin-orbit layered materials are also reviewed

    Extremity tourniquet training at high seas

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    Background Future navy officers require unique training for emergency medical response in the isolated maritime environment. The authors issued a workshop on extremity bleeding control, using four different commercial extremity tourniquets onboard a training sail ship. The purposes were to assess participants' perceptions of this educational experience and evaluate self-application simplicity while navigating on high seas. Methods A descriptive observational study was conducted as part of a workshop issued to volunteer training officers. A post-workshop survey collected their perceptions about the workshops' content usefulness and adequacy, tourniquet safety, self-application simplicity, and device preference. Tourniquet preference was measured by frequency count while the rest of the studied variables on a one-to-ten Likert scale. Frequencies and percentages were calculated for the studied variables, and application simplicity means compared using the ANOVA test (p < 0.05). Results Fifty-one Spanish training naval officers, aged 20 or 21, perceived high sea workshop content’s usefulness, adequacy, and safety level at 8.6/10, 8.7/10, and 7.5/10, respectively. As for application simplicity, CAT and SAM-XT were rated equally with a mean of 8.5, followed by SWAT (7.9) and RATS (6.9), this one statistically different from the rest (p < 0.01). Windlass types were preferred by 94%. Conclusions The training sail ship’s extremity bleeding control workshop was perceived as useful and its content adequate by the participating midshipmen. Windlass types were regarded as easier to apply than elastic counterparts. They were also preferred by nine out of every ten participants

    Interaction of 8 He with 208Pb at near-barrier energies: 4 He and 6 He production

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    Spanish Ministry of Economy and Competitiveness-FPA-2010-22131-CO2-01 (FINURA) y FPA2013-47327-C2-1-RMinistry of Science and Higher Education of Poland-N202 033637National Science Centre of Poland-2013/08/M/ST2/00257 (LEA-COPIGAL) y 2014/14/M/ST2/00738 (COPIN-INFN Collaboration)European Science Foundation-EUI2009-04163432 (EUROGENESIS

    Charge-to-Spin Interconversion in Low-Symmetry Topological Materials

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    The spin polarization induced by the spin Hall effect (SHE) in thin films typically points out of the plane. This is rooted not in a fundamental constraint but on the specific symmetries of traditionally studied systems. We theoretically show that the reduced symmetry of strong spin-orbit coupling materials such as MoTe2{\rm MoTe}_2 or WTe2{\rm WTe}_2 enables new forms of intrinsic SHE that produce large and robust in-plane spin polarizations. Through quantum transport calculations on realistic device geometries with disorder, we show that the charge-to-spin interconversion efficiency can reach θxy80\theta_{xy} \approx 80\% and is gate tunable. The numerically extracted spin diffusion lengths (λs\lambda_s) are long and yield large values of the figure of merit λsθxy810\lambda_s\theta_{xy}\sim 8\text{--}10 nm, largely superior to conventional SHE materials. These findings vividly emphasize how crystal symmetry governs the intrinsic SHE, and how it can be exploited to broaden the range and efficiency of spintronic functionalities.Comment: Any comments are appreciated. 6 pages + 4 figures. Supplemental material available upon reques

    Magnetism, spin dynamics, and quantum transport in two-dimensional systems

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    Two-dimensional (2D) quantum materials offer a unique platform to explore mesoscopic phenomena driven by interfacial and topological effects. Their tunable electric properties and bidimensional nature enable their integration into sophisticated heterostructures with engineered properties, resulting in the emergence of new exotic phenomena not accessible in other platforms. This has fostered many studies on 2D ferromagnetism, proximity-induced effects, and quantum transport, demonstrating their relevance for fundamental research and future device applications. Here, we review ongoing progress in this lively research field with special emphasis on spin-related phenomena
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