2,901 research outputs found
Modelo de cuantificación del consumo energético en edificación
The research conducted in this paper focuses on the generation
of a model for the quantification of energy consumption
in building. This is to be done through one of
the most relevant environmental impact indicators associated
with weight per m2 of construction, as well as the
energy consumption resulting from the manufacturing
process of materials used in building construction.
The practical application of the proposed model on different
buildings typologies in Seville, will provide information
regarding the building materials, the subsystems
and the most relevant construction elements. Hence, we
will be able to observe the impact the built surface has
on the environment.
The results obtained aim to reference the scientific community,
providing quantitative data comparable to other
types of buildings and geographical areas. Furthermore,
it may also allow the analysis and the characterization of
feasible solutions to reduce the environmental impact
generated by the different materials, subsystems and
construction elements commonly used in the different
building types defined in this study.La investigación realizada en el presente trabajo plantea
la generación de un modelo de cuantificación del consumo
energético en edificación, a través de uno de los indicadores
de impacto ambiental más relevantes asociados
al peso por m2 de construcción, el consumo energético
derivado del proceso de fabricación de los materiales de
construcción empleados en edificación.
La aplicación práctica del modelo propuesto sobre diferentes
tipologías edificatorias en Sevilla aportará información
respecto a los materiales de construcción, subsistemas
y elementos constructivos más impactantes,
permitiendo visualizar la influencia que presenta la superficie
construida en cuanto al impacto ambiental generado.
Los resultados obtenidos pretenden servir de referencia
a la comunidad científica, aportando datos numéricos
que podrán ser comparados en otras tipologías y ámbitos
geográficos, a la vez que permitirán analizar y precisar
mejoras en cuanto al impacto ambiental generado
por los diferentes materiales, subsistemas y elementos
constructivos habitualmente utilizados en las tipologías
edificatorias definidas
Antagonistic effect of Trichoderma harzianum VSL291 on phytopathogenic fungi isolated from cocoa (Theobroma cacao L.) fruits
In this study we evaluated the antagonism in vitro of Trichoderma harzianum strain VSL291 against 18 pathogens of cocoa fruits in dual culture. T. harzianum VSL291 inhibited the growth of the phytopathogenic fungi tested between 10.54 and 85.43%. The mycoparasitism of Moniliophthora roreri by T. harzianum VSL291 was studied by light and scanning electron microscopy. T. harzianum VSL291 hyphae grew in parallel with the hyphae of M. roreri and in some places these were united with the hyphae of the cocoa pathogen through small structures like apresorious that tangled in the pathogenic fungus preventing its growth. T. harzianum VSL291 produced lytic enzymes: β-1,3-glucanases, chitinases, proteases, xylanases and lipases, when grown in minimal medium, with fungal cell walls as the sole carbon source. The highest proteolytic activities detected in T. harzianum VSL291 broth with M. roreri, Penicillium expansum and Byssochlamys spectabilis cell walls appear to be associated with increased activities of β-1,3 glucanases, chitinases, lipases, proteases and xylanases and biocontrol index derived from the experiments of confrontation. These results suggest that proteolytic enzymes according to their degree of induction could participate in the antagonistic effect of T. harzianum VSL291 against the fungi tested.Key words: Antagonism, Trichoderma harzianum, mycoparasitism, phytopathogenic fung
Fluencia en compresión de compuestos de AI2O3-SIC con distintas geometrías de reforzante
Se ha analizado la fluencia en compresión de un compuesto cerámico con matriz de alúmina reforzada con un 30% en volumen de
plaquetas de SiC. Los ensayos se realizaron a 1400 °C, con velocidades de deformación entre 10'^ y x 10'^ s"\ y tensiones sobre muestra
de hasta 400 MPa, alcanzándose estados cuasi estacionarios de deformación. Los resultados se comparan con los de varios compuestos
de alúmina reforzada con distintos contenidos de whiskers de carburo de silicio, obtenidos previamente en idénticas condiciones
experimentales. A la luz de consideraciones ampliamente aceptadas sobre los mecanismos de fluencia que actúan en estos
compuestos, se discute la idoneidad de las distintas representaciones para una mejor comprensión del efecto de los reforzantes, en
particular su acción como inhibidores de la fluencia por deslizamiento con acomodación de las fronteras de grano por debajo de una
determinada tensión umbral.Results of compressive creep of an alumina matrix composite reinforced with different contents of silicon carbide platelets or whiskers,
at temperature of 1400 C, with creep rates ranging from 10"^ to 10"^ s"-^, and true stresses up to 400 MPa has been analized.
At this temperature cuasi steady-sates of deformation were achieved. New data is presented, for the material reinforced with platelets,
and are compared with those obtained in the same experimental conditions for other composites reinforced with whiskers. From
widely accepted considerations about the mechanisms responsible for the high temperature diffusional creep in these composites,
different types of data analysis and representation of the results are showed in order to understand the effect of the reinforcements,
particularly the effect on the stress tresshold needed to activate the sliding of grains during diffusional controlled creep
Synthesis of IAN-type N,N-Ligands via Dynamic Kinetic Asymmetric Buchwald-Hartwig Amination
The Pd-catalyzed coupling of racemic heterobiaryl bromides, triflates, or nonaflates with aryl/alkyl primary amines using QUINAP as the ligand provides the corresponding axially chiral heterobiaryl amines with excellent yields and enantioselectivities. Reactivity and structural studies of neutral and cationic oxidative addition intermediates support a dynamic kinetic asymmetric amination mechanism based on the labilization of the stereogenic axis in the latter and suggest that coordination of the amine to the Pd center is the stereodetermining step.Ministerio de Ciencia e Innovación CTQ2013-48164-C2-1-P, CTQ2013-48164-C2-2-P, RYC-2013-12585 for A.R.European FEDER FundsJunta de Andalucía 2012/FQM 1078
Noncommutative 6D Gauge Higgs Unification Models
The influence of higher dimensions in noncommutative field theories is
considered. For this purpose, we analyze the bosonic sector of a recently
proposed 6 dimensional SU(3) orbifold model for the electroweak interactions.
The corresponding noncommutative theory is constructed by means of the
Seiberg-Witten map in 6D. We find in the reduced bosonic interactions in 4D
theory, couplings which are new with respect to other known 4D noncommutative
formulations of the Standard Model using the Seiberg-Witten map.
Phenomenological implications due to the noncommutativity of extra dimensions
are explored. In particular, assuming that the commutative model leads to the
standard model values, a bound -5.63 10^{-8} GeV^{-2}< theta <1.06
10^{-7}GeV^{-2} on the corresponding noncommutativity scale is derived from
current experimental constraints on the S and T oblique parameters. This bound
is used to predict a possibly significant impact of noncommutativity effects of
extra dimensions on the rare Higgs boson decay H-> gamma gamma.Comment: Latex file, 11 pages, 1 figur
Nuevos territorios y sensibilidades culturales: aproximación a investigaciones sobre identidad juvenil y violencia en América Latina
This article brings as a starting point discussions that have been
developed in countries such as Colombia, Mexico, Argentina,
Brazil and Spain on the socio-cultural site of the youth from the
second half of Decade of the eighties. The studies presented cons-
titute an important academic in search of concepts and interpretation related to youth identities, future, violence, city, urban,
citizenship, marginalization violent, movements and paradoxes of
globalization.Este artículo trae como punto de partida las discusiones que se
han desarrollado en países como Colombia, México, Argentina,
Brasil y España sobre el lugar sociocultural de la juventud a partir
de la segunda mitad de la década de los ochenta. Los estudios
presentados en él constituyen entonces una importante base aca-
démica en la búsqueda de conceptos e interpretación relacionados
con las identidades juveniles, en lo relativo al futuro, la violencia,
la ciudad, lo urbano, la ciudadanía, la marginalidad violenta, los
desplazamientos y las paradojas de la globalización
Nuevos territorios y sensibilidades culturales: aproximación a investigaciones sobre identidad juvenil y violencia en América Latina
Este artículo trae como punto de partida las discusiones que se han desarrollado en países como Colombia, México, Argentina, Brasil y España sobre el lugar sociocultural de la juventud a partir de la segunda mitad de la década de los ochenta. Los estudios presentados en él constituyen entonces una importante base aca- démica en la búsqueda de conceptos e interpretación relacionados con las identidades juveniles, en lo relativo al futuro, la violencia, la ciudad, lo urbano, la ciudadanía, la marginalidad violenta, los desplazamientos y las paradojas de la globalización
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