Magnetization vector in the reversible region of a highly anisotropic cuprate superconductor: anisotropy factor and the role of 2D vortex fluctuations

By using a high quality Tl2Ba2Ca2Cu3O10 (Tl-2223) single crystal as an example, the magnetization vector was probed in the reversible region of highly anisotropic cuprate superconductors. For that, we have measured its components along and transverse to the applied magnetic field for different crystal orientations. The analysis shows that the angular dependence of the perpendicular component of the magnetization vector follows the one predicted by a London-like approach which includes a contribution associated with the thermal fluctuations of the 2D vortex positions. For the Tl-2223 crystal studied here, a lower bound for the anisotropy factor was estimated to be about 190.Comment: 6 pages, 3 figure

Warm inflationary model in loop quantum cosmology

A warm inflationary universe model in loop quantum cosmology is studied. In general we discuss the condition of inflation in this framework. By using a chaotic potential, $V(\phi)\propto \phi^2$, we develop a model where the dissipation coefficient $\Gamma=\Gamma_0=$ constant. We use recent astronomical observations for constraining the parameters appearing in our model.Comment: 15 pages, 1 figure, Accepted for publication in Phys. Rev.

Microdroplet fabrication of silver–agarose nanocomposite beads for SERS optical accumulation

Microdroplets have been used as reactors for the fabrication of agarose beads with high uniformity in shape and size, and densely loaded with silver ions, which were subsequently reduced into nanoparticles using hydrazine. The resulting nanocomposite beads not only display a high plasmonic activity, but can also trap/concentrate analytes, which can be identified by means of surface-enhanced Raman scattering (SERS) spectroscopy. The size of the beads is such that it allows the detection of a single bead under a conventional optical microscope, which is very useful to reduce the amount of material required for SERS detectio

On holographic dark-energy models

Different holographic dark-energy models are studied from a unifying point of view. We compare models for which the Hubble scale, the future event horizon or a quantity proportional to the Ricci scale are taken as the infrared cutoff length. We demonstrate that the mere definition of the holographic dark-energy density generally implies an interaction with the dark-matter component. We discuss the relation between the equation-of-state parameter and the energy density ratio of both components for each of the choices, as well as the possibility of non-interacting and scaling solutions. Parameter estimations for all three cutoff options are performed with the help of a Bayesian statistical analysis, using data from supernovae type Ia and the history of the Hubble parameter. The $\Lambda$CDM model is the clear winner of the analysis. According to the Bayesian Information Criterion ($BIC$), all holographic models should be considered as ruled out, since the difference $\Delta BIC$ to the corresponding $\Lambda$CDM value is $> 10$. According to the Akaike Information Criterion ($AIC$), however, we find $\Delta AIC$ $< 2$ for models with Hubble-scale and Ricci-scale cutoffs, indicating, that they may still be competitive. As we show for the example of the Ricci-scale case, also the use of certain priors, reducing the number of free parameters to that of the $\Lambda$CDM model, may result in a competitive holographic model.Comment: 37 pages, 11 figures, 3 tables, statistical analysis improved, accepted for publication in Phys.Rev.

Approaching steady cavitation: The time scale in hypervelocity cavity expansion in work hardening and transformation hardening solids

The extreme phenomena of dynamic cavitation is studied both theoretically and numerically for two families of strain hardening materials. Though analytical results are limited to the steady, self-similar expansion state, the numerical approach facilitates investigation of the transient response, including evaluation of the time required to approach the steady-state limit. While recent studies show that shock waves may appear in hypervelocity cavity expansion fields, the present study suggests a numerical model which can capture the appearance and evolution of these shock waves. That model is validated by comparison with theoretical results at the steady-state limit, thus facilitating future investigation of the dynamic response for materials with more complicated constitutive behavior, for which theoretical results are limited. The constitutive sensitivities are also examined, showing that the specific hardening response of the material has little effect on the cavitation response.The researchers of the University Carlos III of Madrid are indebted to the Ministerio de Ciencia e Innovación de España (Projects DPI/2011-24068 and DPI/2011-23191) for the financial support received which allowed conducting part of this work.Publicad

Seismic and tectonic interpretation of the ESCI-Béticas and ESCI-Alborán deep seismic reflection profiles: structure of the crust and geodynamic implications

The seismic and tectonic interpretation of the ESCI-Béticas and ESCI-Alborán deep seismic reflection profiles provides an overall image of the crust on the northern flank of the Betic-Rif orogenic system. In these interpretations, previous wide-angle refraction-reflection and MCS industrial profiles were used in order to identify the sequence of collisional-extensional events that built up the crust in this escape-type orogenic area. A model of convergence between the Iberian crust and the Alborán domain, including coeval extension due to lateral escape, is consistent with the data presented in this paper

Isolation of <i>Serpulina hyodysenteriae</i> and <i>S. innocens</i> from pigs with swine disentery signs

A partir de muestras de materia fecal recolectada en bolsas de polietileno o hisopados rectales de cerdos con cuadro clínico-patológico de Disentería Porcina se aisló Serpulina hyodysenteriae y Serpulina innocens, esta última apatógena. De los tres medios de cultivos sólidos selectivos utilizados, el medio de Jenkinson et al. fue el que permitió el mayor número de aislamientos e inhibió la flora fecal normal. La identificación del género y especie se realizó sobre la base de las características morfológicas y culturales (producción de beta-hemólisis franca). El crecimiento en los medios de cultivo fue escaso. Se concluye que el aislamiento de Serpulina spp. es sencillo con la metodología indicada y útil para ulteriores estudios de sensibilidad a antimicrobianos.From faecal samples taken in polyethylene bags or rectal swabs of pigs with clinical signs of swine dysentery, Serpulina hyodysenteriae and Serpulina innocens were isolated. The latter nonpathogenic of the three selective solid culture medium in use methods being used, Jenkinson’s proved to be most effective to isolate the organisms and to inhibit the growth of normal faecal bacteria. The identification by genera and species were made on the basis of cultural and morphological differences (product of a clear beta-hemolysis). The growth in liquid culture medium was unsatisfactory. In conclusion, Serpulina spp. isolated by means of the described methodology is sample and useful for further sensitivity research for in vitro testingFacultad de Ciencias Veterinaria

Isolation of <i>Serpulina hyodysenteriae</i> and <i>S. innocens</i> from pigs with swine disentery signs

A partir de muestras de materia fecal recolectada en bolsas de polietileno o hisopados rectales de cerdos con cuadro clínico-patológico de Disentería Porcina se aisló Serpulina hyodysenteriae y Serpulina innocens, esta última apatógena. De los tres medios de cultivos sólidos selectivos utilizados, el medio de Jenkinson et al. fue el que permitió el mayor número de aislamientos e inhibió la flora fecal normal. La identificación del género y especie se realizó sobre la base de las características morfológicas y culturales (producción de beta-hemólisis franca). El crecimiento en los medios de cultivo fue escaso. Se concluye que el aislamiento de Serpulina spp. es sencillo con la metodología indicada y útil para ulteriores estudios de sensibilidad a antimicrobianos.From faecal samples taken in polyethylene bags or rectal swabs of pigs with clinical signs of swine dysentery, Serpulina hyodysenteriae and Serpulina innocens were isolated. The latter nonpathogenic of the three selective solid culture medium in use methods being used, Jenkinson’s proved to be most effective to isolate the organisms and to inhibit the growth of normal faecal bacteria. The identification by genera and species were made on the basis of cultural and morphological differences (product of a clear beta-hemolysis). The growth in liquid culture medium was unsatisfactory. In conclusion, Serpulina spp. isolated by means of the described methodology is sample and useful for further sensitivity research for in vitro testingFacultad de Ciencias Veterinaria

Laser ablation of ceramic Al2O3 at 193 nm and 248 nm: The importance of single-photon ionization processes

9 págs.; 8 figs.The aim of this work is to demonstrate that single-photon photoionization processes make a significant difference in the expansion and temperature of the plasma produced by laser ablation of ceramic Al2O3 in vacuum as well as to show their consequences in the kinetic energy distribution of the species that eventually will impact on the film properties produced by pulsed laser deposition. This work compares results obtained by mass spectrometry and optical spectroscopy on the composition and features of the plasma produced by laser ablation at 193 nm and 248 nm, i.e., photon energies that are, respectively, above and below the ionization potential of Al, and for fluences between threshold for visible plasma and up to ≈2 times higher. The results show that the ionic composition and excitation of the plasma as well as the ion kinetic energies are much higher at 193 nm than at 248 nm and, in the latter case, the population of excited ions is even negligible. The comparison of Maxwell-Boltzmann temperature, electron temperatures, and densities of the plasmas produced with the two laser wavelengths suggests that the expansion of the plasma produced at 248 nm is dominated by a single population. Instead, the one produced at 193 nm is consistent with the existence of two populations of cold and hot species, the latter associated to Al+ ions that travel at the forefront and produced by single photon ionization as well as Al neutrals and double ionized ions produced by electron-ion impact. The results also show that the most energetic Al neutrals in the plasma produced at the two studied wavelengths are in the ground state. © 2013 AIP Publishing LLC.This work has been partially supported by project IZK0Z2 of the Swiss National Science Foundation. R.P. acknowledges a grant from the JAE-doc program, co-funded by European Social Fund.Peer Reviewe