Dissipation in Mesoscopic Superconductors with Ac Magnetic Fields

The response of mesoscopic superconductors to an ac magnetic field is investigated both experimentally and with numerical simulations. We study small square samples with dimensions of the order of the penetration depth. We obtain the ac susceptibitity $\chi=\chi'+i\chi''$ at microwave frequencies as a function of the dc magnetic field $H_{dc}$. We find that the dissipation, given by $\chi''$, has a non monotonous behavior in mesoscopic samples. In the numerical simulations we obtain that the dissipation increases before the penetration of vortices and then it decreases abruptly after vortices have entered the sample. This is verified experimentally, where we find that $\chi''$ has strong oscillations as a function of $H_{dc}$ in small squares of Pb.Comment: 4 pages, 2 figure

Fracturas epifisiolisis graves de la extremidad proximal del radio: resultado tras tratamiento quirúrgico

La fractura-epifisiolisis del cuello radial es una lesión grave que puede originar alteracione s en e l crecimiento epifisario. Presentamo s una seri e de 22 casos revisados con una antigüedad mínima de dos años. Fueron intervenidos 14 pacientes, de los que 10 estaban incluidos en el grupo III o en lesione s de Jeffery. Once enfermos fueron tratado s con cirugí a abierta. Cuando l a intervenció n consisti ó en reducció n abierta y osteosíntesis, los resultados clínicos fueron buenos en el 50%, pero cuando só- lo se practicó reducción cruenta sin asociar sistema estabilizador metálico, éstos llegaron al 100%. En cinco de los ocho paciente s del primer grupo se presentaron calcificacione s articulares y en dos, epifisiodesis. En el segundo grupo no aparecieron ninguna de éstas alteraciones. Creemos que en los casos de fracturas epifisiolisis del cuello radial en niños con gran desplazamiento, el tratamiento ideal es la cuidadosa reducción cruenta evitando fijación con aguja.The fracture epiphysiolysis of radial neck is a grave lesion which may induc e epiphysea l grown disturbances. A review of 22 case s suffering such fracture s was carried out with a mean follow-up of 2 years. Of the total, 14 cases wer e treated by surgery, 10 of thes e showing either type III or Jeffery's fractures. Eleven patients reequired open reduction. In 50% of the cases treated by open reduction and internal fixation, the clinical results wer e satisfactory. When internal fixation was not used, the satisfactory results reached 100%. Five of the 8 cases of the firt groups developed periarticular ossifications and 2 othe r showed epiphyseal closening. Thes e type of complications wer e not seen in the second group. For epiphysiolysis of the radial neck with sever e displacement. The ideal treatment seems to be a careful open reduction avoiding internal fixation

Seasonality effect analysis and recognition of charging behaviors of electric vehicles: A data science approach

Electric vehicles (EVs) presence in the power grid can bring about pivotal concerns regarding their energy requirements. EVs charging behaviors can be affected by several aspects including socio-economics, psychological, seasonal among others. This work proposes a case study to analyze seasonal effects on charging patterns, using a public real-world based dataset that contains information from the aggregated load of the total charging stations of Boulder, Colorado. Our approach targets to forecast and recognize EVs demand considering seasonal factors. Principal component analysis (PCA) was used to provide a visual representation of the variables and their contribution and the correlation among them. Then, twelve classification models were trained and tested to discriminate among seasons the charging load of electric vehicles. Later, a benchmark stage is presented for regression as well as for classification results. For regression models, examined through Mean Absolute Percentage Error (MAPE) and Root Mean Square Error (RMSE), the random Forest provides better prediction than quasi-Poisson model widely. However, it was observed that for large variations in electric vehicles’ charging load, quasi-Poisson fits better than random forest. For the classification models, evaluated through Accuracy and the Area under the Curve, the Lasso and elastic-net regularized generalized linear (GLMNET) model provided the best global performance with accuracy up to 100% when evaluated on the test dataset. The results of this work offer great insights for enhancing demand response strategies that involve PEV charging regarding charging habits across seasons

Nonlinear field theories during homogeneous spatial dilation

The effect of a uniform dilation of space on stochastically driven nonlinear field theories is examined. This theoretical question serves as a model problem for examining the properties of nonlinear field theories embedded in expanding Euclidean Friedmann-Lema\^{\i}tre-Robertson-Walker metrics in the context of cosmology, as well as different systems in the disciplines of statistical mechanics and condensed matter physics. Field theories are characterized by the speed at which they propagate correlations within themselves. We show that for linear field theories correlations stop propagating if and only if the speed at which the space dilates is higher than the speed at which correlations propagate. The situation is in general different for nonlinear field theories. In this case correlations might stop propagating even if the velocity at which space dilates is lower than the velocity at which correlations propagate. In particular, these results imply that it is not possible to characterize the dynamics of a nonlinear field theory during homogeneous spatial dilation {\it a priori}. We illustrate our findings with the nonlinear Kardar-Parisi-Zhang equation

Advances in the study on sexual maturity of Atlantic chub mackerel (Scomber colias) in Cantabrian Sea.

Atlantic chub mackerel (Scomber colias) is a middle size pelagic species distributed on both sides of the Atlantic Ocean. Landings of this species have increased recently in the Iberian Peninsula, likely associated to the increase of its abundance and expansion northwards, probably related to an increment of the sea temperature. The aim of this study is to improve the knowledge of the reproductive biology of the Atlantic chub mackerel and to present updated information on spawning period and maturity ogives that can be used for analytical stock assessment in ICES and its management

Valorization of Tomato Processing by-Products: Fatty Acid Extraction and Production of Bio-Based Materials

A method consisting of the alkaline hydrolysis of tomato pomace by-products has been optimized to obtain a mixture of unsaturated and polyhydroxylated fatty acids as well as a non-hydrolysable secondary residue. Reaction rates and the activation energy of the hydrolysis were calculated to reduce costs associated with chemicals and energy consumption. Lipid and non-hydrolysable fractions were chemically (infrared (IR) spectroscopy, gas chromatography/mass spectrometry (GC-MS)) and thermally (differential scanning calorimetry (DSC), thermogravimetric analysis (TGA)) characterized. In addition, the fatty acid mixture was used to produce cutin-based polyesters. Freestanding films were prepared by non-catalyzed melt-polycondensation and characterized by Attenuated Total Reflected-Fourier Transform Infrared (ATR-FTIR) spectroscopy, solid-state nuclear magnetic resonance (NMR), DSC, TGA, Water Contact Angles (WCA), and tensile tests. These bio-based polymers were hydrophobic, insoluble, infusible, and thermally stable, their physical properties being tunable by controlling the presence of unsaturated fatty acids and oxygen in the reaction. The participation of an oxidative crosslinking side reaction is proposed to be responsible for such modifications.Andalusian Regional Government P11-TEP-7418Spanish Ministerio de Economía y Competitividad AGL2015-65246-R and AGL2017-83036-RFondo Europeo de Desarrollo Regional (FEDER) AGL2015-65246-R and AGL2017-83036-

Uma abordagem para produção de jogos construcionistas baseada no reuso de software

Este artigo tem como objetivo apresentar a Linha de Produto de SoftwareJIndie, uma Linha de Produto que busca facilitar o processo de construção de jogos construcionistas que envolvam o desenvolvimento de um artefato concreto. No construcionismo, o processo de aprendizagem ocorre através da construção de um material concreto pelo estudante. O uso do computador nesse processo de construção de um material concreto é de grande importância, por permitir a construção de objetos de forma mais fácil e virtual através de jogos. Diante dessas informações, para facilitar o processo de construção de jogos voltados ao construcionismo, os desenvolvedores podem optar por uso de Linhas de Produtos de Software, que é uma técnica de produção de software de um determinado domínio. Para avaliar a Linha de Produto de Software proposta neste trabalho, foram desenvolvidos três jogos construcionistas já conhecidos no mercado e os resultados obtidos demonstraram a viabilidade de construção de jogos através do JIndie e um ganho na qualidade e esforço durante a produção, assim como também foi verificado o papel dos jogos construcionistas na escola

Preliminary observation on sexual maturity of chub mackerel (Scomber colias) in the Northern Iberian Atlantic waters (ICES Divisions 27.8.c and 27.9.a.N)

A study of the reproductive biology of the Atlantic chub mackerel (Scomber colias) has been performed in Northern Iberian Atlantic waters (ICES Divisions 27.8.c and 27.9.a.N) based on samples of 14538 specimens (11-50 cm total length) from commercial landings and scientific surveys from 2011-2019. The spawning period was defined based on the monthly prevalence of active females (maturity stages 3, 4 and 5 according to Walsh maturity scale) and temporal variability of females gonado- and hepatosomatic indices (GSI/HSI). Length and age maturity ogives were also estimated for males and females pooling all sampled years together. The spawning period occurred from March to July, with a peak in June. In the 27.8.c area, the GSI, HSI and prevalence of active females increased from March to June and then GSI and prevalence decreased abruptly. In the 27.9.a.N, the peak of spawning was observed earlier (April-May) and with lower intensity than in 27.8.c, but sampling in 27.9.a area was limited to the northern zone (Spanish waters) and are not conclusive. L50 and A50 values estimated with annual data were 22.9 cm and 1.6 years old respectively for both sexes combined, similar to the values estimated with data only from the spawning period: 22.7 cm and 1.5 years old respectively for both sexes combined. Our results were compared with those from previous studies in the NE Atlantic

BVRI Surface Photometry of Isolated Spiral Galaxies

A release of multicolor broad band (BVRI) photometry for a subsample of 44 isolated spirals drawn from the Catalogue of Isolated Galaxies (CIG) is presented. Total magnitudes and colors at various circular apertures, as well as some global structural/morphological parameters are estimated. Morphology is reevaluated through optical and sharp/filtered R band images, (B-I) color index maps, and archive near-IR JHK images from the Two-Micron Survey. The CAS structural parameters (Concentration, Asymmetry, and Clumpiness) were calculated from the images in each one of the bands. The fraction of galaxies with well identified optical/near-IR bars (SB) is 63%, while a 17% more shows evidence of weak or suspected bars (SAB). The sample average value of the maximum bar ellipticity is 0.4. Half of the galaxies in the sample shows rings. We identify two candidates for isolated galaxies with disturbed morphology. The structural CAS parameters change with the observed band, and the tendencies they follow with the morphological type and global color are more evident in the redder bands. In any band, the major difference between our isolated spirals and a sample of interacting spirals is revealed in the A-S plane. A deep and uniformly observed sample of isolated galaxies is intended for various purposes including (i) comparative studies of environmental effects, (ii) confronting model predictions of galaxy evolution and (iii) evaluating the change of galaxy properties with redshift.Comment: 44 pages, 9 figures and 7 tables included. To appear in The Astronomical Journal. For the 43 appendix figures 4.1-4.43 see http://www.astroscu.unam.mx/~avila/Figs4.1_4.43.tar.gz (7.2 Mb tar.gz file