1,715 research outputs found
Mineralizaciones estannovolframíferas en Noia y Lousame, estudio previo.
[Resumen] La región estudiada es rica en mineralizaciones de Sn-W, que son agrupadas por su paragénesis y otras características. Se indica el granito sincinemático como posible causante de mineralizaciones (especialmente, San Finx), y al granito tardicinemático (mina Esperanza). La zona per manece en un bajo nivel de investigación[Abstract] The studied region is rich in Sn-W mineralizations, which are grouped by its mineral paragenesis and other caracteristics. Sincinematic granite is suggested as possible causer of the local mineralization (specially San Finx) anf tardicinematic granite ("Esperanza" mine). This region is in_a low research level actuall
Pairs-Production of Higgs in Association with Bottom Quarks Pairs at Colliders
In a previous paper, we studied the Higgs pair production in the standard
model with the reaction . Based on this, we study
the Higgs pair production via . We evaluate the
total cross section of and calculate the number total of events
considering the complete set of Feynman diagrams at tree-level, and compare
this process with the process . The numerical
computation is done for the energy which is expected to be available at a
possible Next Linear Collider with a center-of-mass energy and luminosity 1000 .Comment: 12 pages, 6 figure
The ALMA Early Science View of FUor/EXor objects. III. The Slow and Wide Outflow of V883 Ori
We present Atacama Large Millimeter/ sub-millimeter Array (ALMA) observations
of V883 Ori, an FU Ori object. We describe the molecular outflow and envelope
of the system based on the CO and CO emissions, which together
trace a bipolar molecular outflow. The CO emission traces the rotational
motion of the circumstellar disk. From the CO blue-shifted emission, we
estimate a wide opening angle of 150 for the outflow
cavities. Also, we find that the outflow is very slow (characteristic velocity
of only 0.65 km~s), which is unique for an FU Ori object. We calculate
the kinematic properties of the outflow in the standard manner using the
CO and CO emissions. In addition, we present a P Cygni profile
observed in the high-resolution optical spectrum, evidence of a wind driven by
the accretion and being the cause for the particular morphology of the
outflows. We discuss the implications of our findings and the rise of these
slow outflows during and/or after the formation of a rotationally supported
disk.Comment: 12 pages, 7 figures, 2 tables. Accepte
Las rocas encajantes de la mineralización aurífera en el yacimiento de La Zarza (Huelva)
La mina La Zarza (Strauss et a1.1981) está situada en la zona central del Cinturón Pirítico Ibérico, cerca del pueblo de Silos de Calañas, unos 30 Km al Nordeste de Tharsis y 20 Km al Oeste de Riotint
Antiguas explotaciones de estaño-wolframio en Arteixo y Laracha (resumen)
[Resumen] En los términos municipales de Arteixo y Laracha se conocen
una serie de pequeñas explotaciones sobre yacimientos de
wolframita-casiterita, de escaso interés tomándolos por separados,
pero con importancia potencial en su conjunto. Todos estos
yacimientos fueron trabajados de forma muy rudimentaria entre los años 1940 a 1968, fecha en que cerró la última mina de la zona. El único estudio conocido sobre alguno de estos yacimientos corresponde a uno realizado por el Instituto Geológico y Minero, que investigó por medio de prospección geoquímica para Sn-W en la zona de Monteagudo-Lendo, clasificando la zona de Laracha como de interés medio a escaso para estas sustancias
Alimentación de modelos cuantitativos con información subjetiva: aplicación Delphi en la elaboración de un modelo de imputación del gasto turístico individual en Catalunya
Recursos en Internet para la enseñanza sobre el cuerpo humano
Internet se ha convertido en la mayor y más accesible biblioteca para las personas
que disponen de un ordenador con conexión a la misma. Nosotras la hemos
utilizado para obtener información útil para la enseñanza sobre el cuerpo
humano, utilizando como criterios de búsqueda: «cuerpo humano, human
body, ideas previas, unidades didácticas cuerpo humano, human body anatomy
y human body unit study». Se presentan los resultados obtenidos organizados
en las siguientes temáticas: concepciones de los alumnos, materiales interactivos
para la enseñanza, diseño y desarrollo de unidades didácticas, oros contenidos
de interés para la enseñanza sobre el cuerpo humano, stios web para
seguir buscando y otras referenciasThe Internet has become the biggest and most accessible library for all those
with a computer and Internet access. We used the Internet to find useful information
for teaching about the human body, using the following terms in
search engines: human body, prior ideas, teaching units, human body anatomy,
and human body unit study. We present the findings obtained grouped
under the following headings: students’ conceptions, interactive teaching
materials, design and development of teaching units, other content of interest
for teaching about the human body, websites for further searches, and
other reference
Process development for bio-ethanol production using wheat straw biomass
Wheat straw is nowadays being
considered a potential lignocellulosic
raw material (LCM) for fuel-ethanol
production as an alternative to starch
or sugar-containing feedstock. In this
work, the evaluation of process
variables (temperature, residence time
and particle size) autohydrolysis
pretreatment of wheat straw for ethanol
production was addressed by means of
design of experiments. The recovery of
hemicellulose derived sugars (HDS) in
the liquid fraction and the ethanol
production of the solid residue
obtained after filtration of pretreated
material were considered as response
variables to different processes
conditions.
Results show that the optimal
conditions were 200 ºC and 30 min,
leading to HDS recovery yield of
31.88% of HDS content in raw
material and ethanol production yield
of 80.1% of theoretical
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