Neural Network identification of halo white dwarfs

The white dwarf luminosity function has proven to be an excellent tool to study some properties of the galactic disk such as its age and the past history of the local star formation rate. The existence of an observational luminosity function for halo white dwarfs could provide valuable information about its age, the time that the star formation rate lasted, and could also constrain the shape of the allowed Initial Mass Functions (IMF). However, the main problem is the scarce number of white dwarfs already identified as halo stars. In this Letter we show how an artificial intelligence algorithm can be succesfully used to classify the population of spectroscopically identified white dwarfs allowing us to identify several potential halo white dwarfs and to improve the significance of its luminosity function.Comment: 15 pages, 3 postscript figures. Accepted for publication in ApJ Letters, uses aasms4.st

Latino Definitions of Success: A Cultural Model of Intercultural Competence

The present study sought to examine Latino intercultural competence via two separate methodologies. Phase 1 entailed discovering and generating themes regarding the features of intercultural competence based on semistructured interviews of 15 Latino adults. Phase 2 included conducting a cultural consensus analysis from the quantitative responses of 46 Latino adults to determine the cultural model of intercultural competence. The major results indicated that the participants, despite variations in socioeconomic and generational statuses, shared a common knowledge base regarding the competencies needed for Latinos to successfully navigate different cultures. Overall, the cultural model of Latino intercultural competence includes a set of skills that integrates traditional cultural values along with attributes of self-efficacy. The findings are discussed within a competence-based conceptualization of cultural adaptation and potential advancements in acculturation research

Ultrafast electrooptic dual-comb interferometry

The femtosecond laser frequency comb has enabled the 21st century revolution in optical synthesis and metrology. A particularly compelling technique that relies on the broadband coherence of two laser frequency combs is dual-comb interferometry. This method is rapidly advancing the field of optical spectroscopy and empowering new applications, from nonlinear microscopy to laser ranging. Up to now, most dual-comb interferometers were based on modelocked lasers, whose repetition rates have restricted the measurement speed to ~ kHz. Here we demonstrate a novel dual-comb interferometer that is based on electrooptic frequency comb technology and measures consecutive complex spectra at a record-high refresh rate of 25 MHz. These results pave the way for novel scientific and metrology applications of frequency comb generators beyond the realm of molecular spectroscopy, where the measurement of ultrabroadband waveforms is of paramount relevance

Embedded Sensor System for Early Pathology Detection in Building Construction

Structure pathology detection is an important security task in building construction, which is performed by an operator by looking manually for damages on the materials. This activity could be dangerous if the structure is hidden or difficult to reach. On the other hand, embedded devices and wireless sensor networks (WSN) are becoming popular and cheap, enabling the design of an alternative pathology detection system to monitor structures based on these technologies. This article introduces a ZigBee WSN system, intending to be autonomous, easy to use and with low power consumption. Its functional parts are fully discussed with diagrams, as well as the protocol used to collect samples from sensor nodes. Finally, several tests focused on range and power consumption of our prototype are shown, analysing whether the results obtained were as expected or not

The effects of metallicity on the Galactic disk population of white dwarfs

It has been known for a long time that stellar metallicity plays a significant role in the determination of the ages of the different Galactic stellar populations, when main sequence evolutionary tracks are employed. Here we analyze the role that metallicity plays on the white dwarf luminosity function of the Galactic disk, which is often used to determine its age. We employ a Monte Carlo population synthesis code that accounts for the properties of the population of Galactic disk white dwarfs. Our code incorporates the most up-to-date evolutionary cooling sequences for white dwarfs with hydrogen-rich and hydrogen-deficient atmospheres for both carbon-oxygen and oxygen-neon cores. We use two different models to assess the evolution of the metallicity, one in which the adopted metallicity is constant with time, but with a moderate dispersion, and a second one in which the metallicity increases with time. We found that our theoretical results are in a very satisfactory agreement with the observational luminosity functions obtained from the Sloan Digital Sky Survey (SDSS) and from the SuperCOSMOS Sky Survey (SSS), independently of the adopted age-metallicity law. In particular, we found that the age-metallicity law has no noticeable impact in shaping the bright branch of the white dwarf luminosity function, and that the position of its cut-off is almost insensitive to the adopoted age-metallicity relationship. Because the shape of the bright branch of the white dwarf luminosity function is insensitive to the age-metallicity law, it can be safely employed to test the theoretical evolutionary sequences, while due to the limited sensitivity of the position of the drop-off to the distribution of metallicities, its location provides a robust indicator of the age of the Galactic disk.Comment: 7 pages, 5 figures, accepted for publication in A&

Brans-Dicke wormholes in nonvacuum spacetime

Analytical wormhole solutions in Brans-Dicke theory in the presence of matter are presented. It is shown that the wormhole throat must not be necessarily threaded with exotic matter.Comment: Minor corrections, to be published in Phys. Rev.

Los fragmentos litúrgicos del Archivo Capitular de Huesca (siglos XI-XVI)

L'Arxiu Capitular d'Osca preserva un valuós conjunt de 15 fragments litúrgics (segles XI-XVI) fins avui pràcticament inèdit. En aquest article en presentem la catalogació i n'alitzem les principals peculiaritats en els aspectes paleogràfic, litúrgic i musical. Pretenem, igualment, determinar llur hipotètica vinculació amb la seu d'Osca, així com llur rellevància de cara a identificar les xarxes de transmissió litúrgica entre Aragó i els seus territoris contigus al llarg de l'Edat Mitjana.The Archivo Capitular de Huesca preserves a valuable ensemble of 15 liturgical fragments (11th-16th cent.), practically unpublished until now. This article presents their cataloguing and analyses their main peculiarities in the palaeographical, liturgical and musical aspects. At the same time we hope to determine their hypothetical relationship with the See of Huesca, as well as their relevance in the identification of the liturgical transmission networks between Aragon and the bordering territories along the Middle Ages.El Archivo Capitular de Huesca preserva un valioso conjunto de quince fragmentos litúrgicos (ss. XI-XVI) hasta la fecha prácticamente inédito. En este artículo presentamos su catalogación y analizamos sus principales peculiaridades en los niveles paleográfico, litúrgico y musical. Pretendemos, de igual modo, determinar su hipotética vinculación con la sede oscense, así como su relevancia de cara a identificar las redes de transmisión litúrgica entre Aragón y sus territorios colindantes a lo largo de la Edad Media

En busca de la energía sostenible

Nombrado Doctor Honoris Causa el dia 3 de febrero del 200

Los fragmentos litúrgicos del Archivo Capitular de Huesca (siglos XI-XVI)

L'Arxiu Capitular d'Osca preserva un valuós conjunt de 15 fragments litúrgics (segles XI-XVI) fins avui pràcticament inèdit. En aquest article en presentem la catalogació i n'alitzem les principals peculiaritats en els aspectes paleogràfic, litúrgic i musical. Pretenem, igualment, determinar llur hipotètica vinculació amb la seu d'Osca, així com llur rellevància de cara a identificar les xarxes de transmissió litúrgica entre Aragó i els seus territoris contigus al llarg de l'Edat Mitjana.The Archivo Capitular de Huesca preserves a valuable ensemble of 15 liturgical fragments (11th-16th cent.), practically unpublished until now. This article presents their cataloguing and analyses their main peculiarities in the palaeographical, liturgical and musical aspects. At the same time we hope to determine their hypothetical relationship with the See of Huesca, as well as their relevance in the identification of the liturgical transmission networks between Aragon and the bordering territories along the Middle Ages.El Archivo Capitular de Huesca preserva un valioso conjunto de quince fragmentos litúrgicos (ss. XI-XVI) hasta la fecha prácticamente inédito. En este artículo presentamos su catalogación y analizamos sus principales peculiaridades en los niveles paleográfico, litúrgico y musical. Pretendemos, de igual modo, determinar su hipotética vinculación con la sede oscense, así como su relevancia de cara a identificar las redes de transmisión litúrgica entre Aragón y sus territorios colindantes a lo largo de la Edad Media

Factors subjectius de la construcció sostenible.

El concepte de sostenibilitat requereix del concepte de societat sostenible. Quan ens referim a la sostenibilitat d'un sistema, ens referim a la d'un sistema humà, amb els seus aspectes materials i culturals, i que ha sofert (o ha arribat a) un desplaçament respecte de l'estat natural. La conservació d’aquest desplaçament és el que ens preocupa. Quan considerem la sostenibilitat en l'ambient construït, aquestes dues categories material i cultural prenen la forma d'un debat que s'ha vingut donant al llarg de tota la modernitat, en el qual els rols d'arquitecte i enginyer s'oposen i completen. Al primer li correspondrien les qüestions de disseny, estil, història, aspectes culturals en general; al segon, les qüestions de càlcul, construcció, manteniment, aspectes materials en general. Durant aquest debat, la postura predominant ha anat alternant d’un costat a l’altre i, la majoria de vegades, s'ha produït una escissió on les solucions arquitectòniques i d’enginyeria més que complementar-se s’han superposat. Com explica McCleary respecte de l'enginyer estructuralista: “L'origen del cisma és clar: Per a l'arquitecte, el disseny comença per considerar la humanització de l'espai – la preocupació principal és habitar; per a l'enginyer, el disseny comença per respondre a les propietats dels materials i a la lògica de la mecànica estructural – el focus és a l'estructuració” . En segon lloc, és necessari considerar l'arquitectura com un fenomen social en les seves causes i efectes. El fet que els edificis conformin l'espai continent on es desenvolupen la majoria de les activitats humanes, els atorga la seva importància com factor de conformació i, alhora, expressió d'una societat. L'ambient construït no és únicament un suport físic, sinó que a més involucra la interacció entre aquest i els seus ocupants. Aquestes consideracions preliminars serveixen per a emmarcar les dimensions del problema i alhora per a ordenar l'anàlisi subsegüent.El concepto de sostenibilidad requiere del concepto de sociedad sostenible. Cuando nos referimos a la sostenibilidad de un sistema, nos referimos a la de un sistema humano, con sus aspectos materiales y culturales, y que ha sufrido (o alcanzado) un desplazamiento respecto del estado natural. Es la conservación de este desplazamiento lo que nos preocupa. Al considerar la sostenibilidad en el ambiente construido, estas dos categorías de lo material y lo cultural toman la forma de un debate que se ha venido dando a lo largo de toda la modernidad, en el que los roles de arquitecto e ingeniero se oponen y complementan. Al primero le corresponderían las cuestiones de diseño, estilo, historia, aspectos culturales en general; al segundo, las cuestiones de cálculo, construcción, mantenimiento, aspectos materiales en general. Durante este debate, la postura predominante ha ido alternando de lado, y la mayor parte de las veces se ha producido una escisión donde las soluciones arquitectónicas e ingenieriles se superponen más de lo que se complementan. Como explica McCleary respecto del ingeniero estructuralista: “El origen del cisma es claro: para el arquitecto, el diseño comienza por considerar la humanización del espacio – la preocupación principal es el habitar; para el ingeniero, el diseño comienza por responder a las propiedades de los materiales y a la lógica de la mecánica estructural – el foco es en la estructuración”. En segundo lugar es necesario considerar a la arquitectura como fenómeno social en sus causas y efectos. El hecho de que los edificios conformen el espacio continente donde se desarrolla la mayoría de las actividades humanas les otorga su importancia como factor de conformación, y a la vez expresión de una sociedad. El ambiente construido no es solamente un soporte físico, sino que además involucra la interacción entre éste y sus ocupantes. Estas consideraciones preliminares sirven para enmarcar las dimensiones del problema y a la vez para ordenar el análisis subsiguiente