Tailored particle current in an optical lattice by a weak time-symmetric harmonic potential

Quantum ratchets exhibit asymptotic currents when driven by a time-periodic potential of zero mean if the proper spatio-temporal symmetries are broken. There has been recent debate on whether directed currents may arise for potentials which do not break these symmetries. We show here that, in the presence of degeneracies in the quasienergy spectrum, long-lasting directed currents can be induced, even if the time reversal symmetry is not broken. Our model can be realized with ultracold atoms in optical lattices in the tight-binding regime, and we show that the time scale of the average current can be controlled by extremely weak fields.Comment: 4 pages, 4 figure

Design of a robust and efficient power electronic interface for the grid integration of solar photovoltaic generation systems

Nowadays, the penetration of photovoltaic (PV) solar power generation in distributed generation (DG) systems is growing rapidly. This condition imposes new requirements to the operation and management of the distribution grid, especially when high integration levels are achieved. Under this scenario, the power electronics technology plays a vital role in ensuring an effective grid integration of the PV system, since it is subject to requirements related not only to the variable source itself but also to its effects on the stability and operation of the electric grid. This paper proposes an enhanced interface for the grid connection of solar PV generation systems. The topology employed consists of a three-level cascaded Z-source inverter that allows the flexible, efficient and reliable generation of high quality electric power from the PV plant. A full detailed model is described and its control scheme is designed. The dynamic performance of the designed architecture is verified by computer simulations.Fil: Pacas, J. M.. Inst. Of Pow. Electro. And Electri. Driv., Univ. Siegen; AlemaniaFil: Molina, Marcelo Gustavo. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Energía Eléctrica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; ArgentinaFil: Dos Santos, E. C.. Universidade Federal de Campina Grande; Brasi

Intra-breed genetic diversity characterization of the Iberian pig

Ponencia publicada en ITEA, vol.104El desenvolvimiento en el tiempo de subpoblaciones aisladas adscritas a un mismo tipo racial es el origen de la diversidad natural que surge en toda raza animal enriqueciéndola. El Cerdo Ibérico no ha sido ajeno a este proceso, acumulando a lo largo de los siglos una gran heterogeneidad intrarracial, reflejada en un valor alto (0,19) para el FST de Wright entre las subpoblaciones analizadas. En el presente trabajo abordaremos el estudio de esta diversidad genética interna del Cerdo Ibérico con especial atención a las cuatro estirpes principales (Negro Lampiño, Entrepelado, Retinto y Torbiscal), sin descuidar, no obstante, otras estirpes y líneas que la integran. Para ello partiremos de diferentes estudios de caracterización de las estirpes y líneas del Cerdo Ibérico. Resaltaremos no sólo sus diferencias genéticas sino también las habidas entre sus productos para consumo en fresco (solomillos), en los que la estirpe Negro Lampiño muestra los porcentajes de proteína, capacidad de retención de agua (CRA) e infiltración grasa intramuscular más elevados (23.74, 17.06 y 5.28, respectivamente), definiendo una calidad diferenciada. Finalmente aportaremos una clasificación que explique la estructura interna del Cerdo Ibérico.The evolution in time of isolated subpopulations assigned to a same breed is the origin of the natural diversity that arises in any breed animal enriching it. The Iberian Pig breed has not been unaware of this process, accumulating throughout the centuries a great intra-breed heterogeneity that is reflected by a high FST value (0.19) among the subpopulations analyzed. In the present study we will undertake the assessment of the internal genetic diversity of the Iberian Pig breed with special attention to the four main strains (Negro Lampiño, Entrepelado, Retinto and Torbiscal), without forgetting others strains and lines that integrate Iberian Pig Breed. To that purpose, we based on different characterization studies of the strains and lines of the Iberian Pig breed. We emphasize not only their genetic differences but also the differences among their meat products for fresh consumption (tenderloin) by strain, in which Negro Lampiño shows the higher percentages of protein, water-holding capacity (ARC) and intramuscular fat infiltration (23.74, 17.06 and 5.28, respectively), defining a differentiated quality. Finally, we expose a classification to explain the population structure of the Iberian Pig Breed

Singular open book structures from real mappings

We prove extensions of Milnor's theorem for germs with nonisolated singularity and use them to find new classes of genuine real analytic mappings $\psi$ with positive dimensional singular locus \Sing \psi \subset \psi^{-1}(0), for which the Milnor fibration exists and yields an open book structure with singular binding.Comment: more remark

Quasi-normal modes of the scalar hairy black hole

We calculate QNMs of the scalar hairy black hole in the AdS background using Horowitz-Hubeny method for the potential that is not known in analytical form. For some black hole parameters we found pure imaginary frequencies. Increasing of the scalar field mass does not cause the imaginary part to vanish, it reaches some minimum and then increases, thus in the case under consideration the infinitely long living modes (quasi-resonances) do not appear.Comment: 17 pages, 17 figures, LaTe

Personality traits in patients with cluster headache: a comparison with migraine patients

Background: Cluster headache (CH) has been associated with certain personality traits and lifestyle features, but there are few studies assessing personality profiles in CH. We aimed to analyze personality traits in patients with CH, and to compare them with those found in migraine. Methods: We included all consecutive patients with CH attending 5 outpatient offices between January and December 2013. Personality traits were evaluated using the Salamanca screening test, a validated inventory assessing 11 personality traits grouped in 3 clusters. We analyzed the test results in this population, and compared them with those of a migraine population previously assessed with the same test. Results: Eighty patients with CH (75 men, 5 women; mean age, 43.2 ± 9.9 years) were recruited. The reference population consisted of 164 migraine patients (30 men, 134 women; mean age 36.4 ± 12.7 years). In CH patients, the most frequent personality traits were anancastic (52.5 %), anxious (47.5 %), histrionic (45 %), schizoid (42.5 %), impulsive (32.5 %) and paranoid (30 %). When compared to migraine patients, paranoid (p < 0.001; x2 test), and schizoid traits (p = 0.007; x2 test) were significantly more prevalent in CH patients. In logistic regression analysis the paranoid trait was significantly associated with CH (p = 0.001; OR: 3.27, 95 % CI 1.66–6.43]). Conclusion: According to the Salamanca screening test, personality traits included in cluster A (odd or eccentric disorders) are more prevalent in CH patients than in a population of migraineurs. Larger studies are needed to determine whether certain personality traits are related to CH

Arquitectura centrada en la web para el control y monitoreo de funcionalidad domótica

En el presente paper se ilustra una arquitectura para el desarrollo de sistemas en ambientes distribuidos homogéneos centrados en la Web, que a efectos de ser llevado a la práctica, se discute el diseño e implementación de una aplicación para el control y monitoreo con funcionalidad domótica. La arquitectura empleada se basa en el patrón arquitectural denominado Web Delivery. Se presentan consideraciones finales y futuros avances en el empleo de arquitecturas de software con potencial repercusión para el campo de la DomóticaÁrea: Ingeniería de Software - Bases de DatosRed de Universidades con Carreras en Informática (RedUNCI

Folksonomies and clustering in the collaborative system CiteULike

We analyze CiteULike, an online collaborative tagging system where users bookmark and annotate scientific papers. Such a system can be naturally represented as a tripartite graph whose nodes represent papers, users and tags connected by individual tag assignments. The semantics of tags is studied here, in order to uncover the hidden relationships between tags. We find that the clustering coefficient reflects the semantical patterns among tags, providing useful ideas for the designing of more efficient methods of data classification and spam detection.Comment: 9 pages, 5 figures, iop style; corrected typo

Cosmological parameter estimation using Very Small Array data out to ℓ= 1500

We estimate cosmological parameters using data obtained by the Very Small Array (VSA) in its extended configuration, in conjunction with a variety of other cosmic microwave background (CMB) data and external priors. Within the flat Λ cold dark matter (ΛCDM) model, we find that the inclusion of high-resolution data from the VSA modifies the limits on the cosmological parameters as compared to those suggested by the Wilkinson Microwave Anisotropy Probe (WMAP) alone, while still remaining compatible with their estimates. We find that Ωbh2= 0.0234+0.0012−0.0014, Ωdmh2= 0.111+0.014−0.016, h= 0.73+0.09−0.05, nS= 0.97+0.06−0.03, 1010AS= 23+7−3 and τ= 0.14+0.14−0.07 for WMAP and VSA when no external prior is included. On extending the model to include a running spectral index of density fluctuations, we find that the inclusion of VSA data leads to a negative running at a level of more than 95 per cent confidence ( nrun=−0.069 ± 0.032 ), something that is not significantly changed by the inclusion of a stringent prior on the Hubble constant. Inclusion of prior information from the 2dF galaxy redshift survey reduces the significance of the result by constraining the value of Ωm. We discuss the veracity of this result in the context of various systematic effects and also a broken spectral index model. We also constrain the fraction of neutrinos and find that fν < 0.087 at 95 per cent confidence, which corresponds to mν < 0.32 eV when all neutrino masses are equal. Finally, we consider the global best fit within a general cosmological model with 12 parameters and find consistency with other analyses available in the literature. The evidence for nrun < 0 is only marginal within this model