169 research outputs found
Delta invariant of curves on rational surfaces I. An analytic approach
We prove that if (C, 0) is a reduced curve germ on a rational surface singularity (X, 0) then its delta invariant can be recovered by a concrete expression associated with the embedded topological type of the pair C X. Furthermore, we also identify it with another (a priori) embedded analytic invariant, which is motivated by the theory of adjoint ideals. Finally, we connect our formulae with the local correction term at singular points of the global Riemann-Roch formula, valid for projective normal surfaces, introduced by Blache
Delta invariant of curves on rational surfaces I. An analytic approach
We prove that if (C, 0) is a reduced curve germ on a rational surface singularity (X, 0) then its delta invariant can be recovered by a concrete expression associated with the embedded topological type of the pair C X. Furthermore, we also identify it with another (a priori) embedded analytic invariant, which is motivated by the theory of adjoint ideals. Finally, we connect our formulae with the local correction term at singular points of the global Riemann-Roch formula, valid for projective normal surfaces, introduced by Blache
Rendimientos productivos y calidad de la canal de hembras, machos castrados quirurgicamente y machos inmunocastrados procedentes de líneas paternas duroc y pietrain
Tradicionalmente la castración quirúrgica ha sido la práctica más habitual en la producción de cerdo blanco destinado a la industria de productos cárnicos curados. La castración quirúrgica conlleva un empeoramiento de los rendimientos productivos y penaliza el bienestar animal. Como alternativa ha surgido la inmunización de los cerdos contra el factor de liberación de la gonadotropina (GnRH) (Fàbrega et al., 2010). La inmunocastración suprime la función testicular (Zamaratskaia et al., 2008) y reduce la producción de androsterona (Dunshea et al., 2001) y escatol (Matthews et al., 2000) así como la agresividad (Jaros et al., 2005). Por tanto, la inmunocastración puede ser una alternativa a la castración física en situaciones comerciales. Por otro lado, para la obtención de productos curados se precisan canales con más grasa y mayor proporción de partes nobles que para productos frescos, por lo que se utilizan estrategias como aumentar el peso al sacrificio o el cruce con líneas paternas específicas. El objetivo de este estudio fue evaluar el rendimiento productivo y la calidad de la canal de hembras enteras (HE), machos castrados (MC) y machos inmunocastrados (MI) procedentes de genéticas paternas Duroc (DU) y Pietrain (PI) con un peso al sacrificio de 134 kg
Efecto de la densidad en cebo sobre el rendimiento productivo, la composición de la carne y el perfil de ácidos grasos de cerdos sacrificados con 110 kg de peso
El número de cerdos por cuadra y la densidad influyen sobre el rendimiento productivo
(Edmons et al., 1998). Además, la densidad de cría puede afectar a la calidad de la canal y
de la carne (Estevez et al., 2003), ya que una reducción del espacio disponible da lugar a
peleas y mordeduras de colas. Sin embargo, la producción de carne por m
2
aumenta con la
densidad con un mejor aprovechamiento de la superficie disponible. Por otro lado, la
densidad podría afectar de distinto modo a hembras (HE) y a machos castrados (MC)
debido posiblemente al menor consumo voluntario de pienso de las HE. A este particular,
Hamilton et al. (2003) observaron que a altas densidades de cría las HE fueron
relativamente más magras mientras que los MC eran relativamente más grasos. Cambios en
la densidad de cría, pueden afectar a la composición en ácidos grasos de la canal debido a
cambios en el consumo y a la utilización del alimento (Nürnberg et al., 1998). El objetivo de
este estudio fue comparar el efecto de la densidad de cebo de HE y MC con alto potencial
de crecimiento, sobre el rendimiento productivo y la composición de la carne y el perfil de
ácidos grasos en cerdos de 19 a 109 kg PV
Search for an annual modulation of dark-matter signals with a germanium spectrometer at the Sierra Grande Laboratory
Data collected during three years with a germanium spectrometer at the Sierra
Grande underground laboratory have been analyzed for distinctive features of
annual modulation of the signal induced by WIMP dark matter candidates. The
main motivation for this analysis was the recent suggestion by the DAMA/NaI
Collaboration that a yearly modulation signal could not be rejected at the 90%
confidence level when analyzing data obtained with a high-mass low-background
scintillator detector. We performed two different analyses of the data: First,
the statistical distribution of modulation-significance variables (expected
from an experiment running under the conditions of Sierra Grande) was compared
with the same variables obtained from the data. Second, the data were analyzed
in energy bins as an independent check of the first result and to allow for the
possibility of a crossover in the expected signal. In both cases no
statistically significant deviation from the null result was found, which could
support the hypothesis that the data contain a modulated component. A plot is
also presented to enable the comparison of these results to those of the DAMA
collaboration.Comment: New version accepted by Astroparticle Physics. Changes suggested by
the referee about the theoretical prediction of rates are included.
Conclusions remain unaffected. 14 pages, LaTeX, 7 figures. Uses epsfig macr
Evidence of a new geothermal prospect in the Northern-Central trans-Mexican volcanic belt: Rancho Nuevo, Guanajuato, Mexico
Peer ReviewedPostprint (author's final draft
La congestión residual y la intuición clínica en la insuficiencia cardiaca descompensada
Congestive symptoms are the key to recognising decompensated heart failure, whose treatment is based on reducing the congestion until a clinical situation has been reached that allows the patient to be discharged to continue outpatient treatment. The important aspect is not the degree of congestion at admission but rather the congestion that persists after energetic diuretic therapy. The persistence of congestive signs following an apparently correct and effective therapy has been called residual congestion and is associated with a poor prognosis. The tools for determining this condition are still rudimentary. Methods therefore need to be developed that enable a more accurate assessment
Experimental Search for Solar Axions
A new technique has been used to search for solar axions using a single crystal germanium detector. It exploits the coherent conversion of axions into photons when their angle of incidence satisfies a Bragg condition with a crystalline plane. The analysis of approximately 1.94 kg.yr of data from the 1-kg DEMOS detector in Sierra Grande, Argentina, yields a new laboratory bound on axion-photon coupling of g_{a,\gamma\gamma}<2.7\times 10^{-9} GeV^{-1} independent of axion mass up to \sim 1 keV
Novel utility-scale photovoltaic plant electroluminescence maintenance technique by means of bidirectional power inverter controller
Nowadays, photovoltaic (PV) silicon plants dominate the growth in renewable energies generation. Utility-scale photovoltaic plants (USPVPs) have increased exponentially in size and power in the last decade and, therefore, it is crucial to develop optimum maintenance techniques. One of the most promising maintenance techniques is the study of electroluminescence (EL) images as a complement of infrared thermography (IRT) analysis. However, its high cost has prevented its use regularly up to date. This paper proposes a maintenance methodology to perform on-site EL inspections as efficiently as possible. First, current USPVP characteristics and the requirements to apply EL on them are studied. Next, an increase over the automation level by means of adding automatic elements in the current PV plant design is studied. The new elements and their configuration are explained, and a control strategy for applying this technique on large photovoltaic plants is developed. With the aim of getting on-site EL images on a real plant, a PV inverter has been developed to validate the proposed methodology on a small-scale solar plant. Both the electrical parameters measured during the tests and the images taken have been analysed. Finally, the implementation cost of the solution has been calculated and optimised. The results conclude the technical viability to perform on-site EL inspections on PV plants without the need to measure and analyse the panel defects out of the PV installation
Morphosedimentary characterization of sublittoral beds of San Andres beach (Malaga Bay) using side scan sonar
The present work contributes to the characterization and mapping of sublittoral seabed located in the
nearshore of the San Andrés Beach in Malaga. This zone extends between the outer dock of the Malaga
harbor and the Guadalhorce river mouth. The study was done using the description of the acoustic reflection
patterns obtained with Side Scan Sonar thechniques. These patterns have been identified with lithological
changes, morphological features, dimension and orientation of bedforms, underwater patrimony and
evidences of the human activity on the seabe
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