2,676 research outputs found
An optimization tool to design the field of a Solar Power Tower plant allowing heliostats of different sizes
The design of a Solar Power Tower plant involves the optimization of the heliostat field layout. Fields are usually designed to have all heliostats of identical size. Although the use of a single heliostat size has been questioned in the literature, there are no tools to design fields with heliostats of several sizes at the same time.
In this paper, the problem of optimizing the heliostat field layout of a system with heliostats of different sizes is addressed. We present an optimization tool to design solar plants allowing two heliostat sizes. The methodology is illustrated with a particular example considering different heliostat costs.MTM2013-41286-P (Spain)
MTM2015-65915-R (Spain)
P11-FQM-7603 (Andalucía)
TD1207 (EU COST Action
Streptococcus parasanguinis: new pathogen associated with asymptomatic mastitis in sheep.
We describe two unusual cases in sheep of subclinical mastitis caused by Streptococcus parasanguinis. This bacterium has been associated with the development of experimental endocarditis; its presence at relatively high concentrations in apparently healthy sheep milk may pose a health risk in persons with predisposing heart lesions
Comparative analysis of the serve in volleyball between the spanish championships 2005-2010
El objetivo fue analizar los cambios que ha experimentado el saque desde el
Campeonato de España cadete masculino de 2005 al de 2010. Mediante la
observación sistemática se analizaron 1594 acciones, en las cuales se midieron
las siguientes variables: zona de origen, eficacia, tipo de saque, zona de
recepción, función del receptor, dirección y temporalidad. Los resultados
reflejaron que en los últimos años, el saque realizado por jugadores de categoría
de formación ha sufrido modificaciones relevantes, tales como, mejora de la
eficacia, incremento del empleo del saque en salto, y realización del saque con
un carácter más táctico. Pese a la mayor aproximación del saque a los perfiles
existentes en alto nivel, se recomienda que el saque de voleibol en categorías
de formación se entrene en función de las características y nivel de los
jugadores, evitando el mimetismo de lo que acontece en alto nivelThe aim of this research was to analyze the changes in the characteristics of
the serve between the male Under-16 Spanish Championships that took place
in 2005 and 2010. Through systematic observation 1594 actions were analyzed.
The measured variables were: serve zone, effectiveness, serve type, reception
zone, in-game role of the receptor, serve direction and timing. The results
showed that in recent years, the serve performed by players at training stages
has undergone significant changes, such as improved efficiency, increased use
of jump serve, and execution of the serve with a more tactical role. Despite of
the closest approach of the serve to the existing high level profiles, it is
recommended to train the serve in volleyball training stages according to the
characteristics and level of players, avoiding mimicry of what happens at a high
levelEste trabajo ha sido realizado gracias al apoyo del Programa de Formación de Personal
Investigador (FPI) de la Consejería de Empleo, Empresa e Innovación del Gobierno
de Extremadura (España), y gracias al Ministerio de Ciencia e Innovación en el Plan Nacional de I+D+I 2008-2011 (ref. DEP2011-27503
Composición, propiedades, estabilidad y comportamiento térmico del aceite de semilla de tamarindo (Tamarindus indica)
The composition, thermal stability and phase behavior of tamarind (Tamarindus indica) seed oil were analyzed to contribute to the exploration of their potential uses. The oil was extracted from the kernel of the tamarind seed with hexane, and its main physical, chemical and thermal properties were analyzed by infrared spectrometry, gas chromatography-mass spectrometry, DSC, and TGA. The results showed that the tamarind seed had a 3.76 ± 0.20% oil with a saponification index of 174.80 ± 9.87 mg KOH/g and the major fatty acids were lignoceric (20.15%), oleic (18.99%) and palmitic (11.99%). Stearic, behenic, linoleic, arachidic, and other fatty acids were also present. TGA and DSC showed that in an inert atmosphere, the triacylglycerols of tamarind seed oil (TSO) are decomposed in a single stage that starts at 224.1 °C and in an air atmosphere in three stages, initiating its decomposition at 218 °C. The TSO showed crystallization and fusion curves with a single maximum peak with Tonset and Toffset of 20.16 and ?38.8 °C and ?22.2 and 28.6 °C, respectively. The solid fat profile of the oil showed a semi-solid and liquid consistency in the ambient temperature range. The composition, thermal and phase behavior showed that TSO is potentially useful for alimentary, pharmacological, and cosmetological purposes.La composición, estabilidad y comportamiento térmico del aceite de semilla de tamarindo (Tamarindus indica) fueron analizadas con el fin de contribuir al conocimiento de sus potenciales usos. El aceite fue extraído del núcleo de la semilla con hexano y analizado mediante sus principales propiedades físicas, químicas y térmicas mediante espectrometría infrarroja, cromatografía de gases, espectroscopia de masas, calorimetría (DSC) y termogravimetría (TGA). Los resultados mostraron que las semillas del tamarindo tuvieron un contenido de aceite de 3,76 ± 0,20%, con un índice de saponificación de 174,80 ± 9,87mg KOH/g y ácidos grasos mayoritarios: Lignocérico (20,15%), oleico (18,99%), palmítico (11,99%) y en cantidades menores los ácidos esteárico, behénico, linoleico y araquídico, entre otros. El análisis mediante TGA y DSC mostró que la temperatura inicial de descomposición del aceite fue de 224,1 °C en una sola etapa en atmósfera inerte y en atmósfera de aire fue a 218 °C en tres etapas. El aceite mostró curvas de cristalización y fusión con un solo máximo, iniciándose y finalizando estos cambios de fase a 20,16 y -38,8 °C, and -22,2 y 28,6 °C, respectivamente. Estas propiedades mostraron que el aceite de la semilla de tamarindo tiene potenciales aplicaciones en alimentos y productos farmacológicos y cosméticos
The intracluster magnetic field in the double relic galaxy cluster Abell 2345
Magnetic fields are ubiquitous in galaxy clusters, yet their radial profile, power spectrum, and connection to host cluster
properties are poorly known. Merging galaxy clusters hosting diffuse polarized emission in the form of radio relics offer a
unique possibility to study the magnetic fields in these complex systems. In this paper, we investigate the intracluster magnetic
field in Abell 2345. This cluster hosts two radio relics that we detected in polarization with 1–2 GHz Jansky Very Large Array
observations. X-ray XMM–Newton images show a very disturbed morphology. We derived the rotation measure (RM) of five
polarized sources within ∼1 Mpc from the cluster centre applying the RM synthesis. Both, the average RM and the RM dispersion
radial profiles probe the presence of intracluster magnetic fields. Using the thermal electron density profile derived from X-ray
analysis and simulating a 3D magnetic field with fluctuations following a power spectrum derived from magneto-hydrodynamical
cosmological simulations, we build mock RM images of the cluster. We constrained the magnetic field profile in the eastern
radio relic sector by comparing simulated and observed RM images. We find that, within the framework of our model, the data
require a magnetic field scaling with thermal electron density as B(r) ∝ n e (r). The best model has a central magnetic field (within
a 200 kpc radius) of 2.8±0.1 μG. The average magnetic field at the position of the eastern relic is ∼ 0.3 μG, a factor 2.7 lower
than the equipartition estimate
Direct mass measurements of 19B, 22C, 29F, 31Ne, 34Na and other light exotic nuclei
We report on direct time-of-flight based mass measurements of 16 light
neutron-rich nuclei. These include the first determination of the masses of the
Borromean drip-line nuclei B, C and F as well as that of
Na. In addition, the most precise determinations to date for N
and Ne are reported. Coupled with recent interaction cross-section
measurements, the present results support the occurrence of a two-neutron halo
in C, with a dominant configuration, and a
single-neutron halo in Ne with the valence neutron occupying
predominantly the 2 orbital. Despite a very low two-neutron separation
energy the development of a halo in B is hindered by the 1
character of the valence neutrons.Comment: 5 page
Evaporation residues produced in spallation of 208Pb by protons at 500A MeV
The production cross sections of fragmentation-evaporation residues in the
reaction Pb+p at 500A MeV have been measured using the inverse-kinematics
method and the FRS spectrometer (GSI). Fragments were identified in nuclear
charge using ionisation chambers. The mass identification was performed
event-by-event using the B-rho - TOF - Delta-E technique. Although
partially-unresolved ionic charge states induced an ambiguity on the mass of
some heavy fragments, production rates could be obtained with a high accuracy
by systematically accounting for the polluting ionic charge states. The
contribution of multiple reactions in the target was subtracted using a new,
partly self-consistent code. The isobaric distributions are found to have a
shape very close to the one observed in experiments at higher energy. Kinematic
properties of the fragments were also measured. The total and the isotopic
cross sections, including charge-pickup cross sections, are in good agreement
with previous measurements. The data are discussed in the light of previous
spallation measurements, especially on lead at 1 GeV
Lactococcus lactis subsp. lactis infection in waterfowl: first confirmation in animals.
We report the first description, confirmed by bacteriologic and molecular (polymerase chain reaction and pulsed-field gel electrophoresis) analysis, of an infection in animals caused by Lactococcus lactis subsp. lactis, affecting waterfowl
Evaluación de las necesidades hídricas de tres variedades de fresas y de su respuesta frente a un recorte hídrico moderado
Instituto Nacional de Investigaciones RTA2012-00001-00-00FEDER CC10-009-C02-0
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