2,132 research outputs found
Optimización de tratamientos a baja temperatura para incrementar fenoles hidrofÃlicos en la fracción lÃquida de Alperujo
Hydrophilic phenols are the main bioactive compounds in alperujo. Among them, 3,4-Dihydroxyphenylglycol (DHPG), Hydroxytyrosol (HT) and Tyrosol (Ty), are the most relevant and deeply studied. These compounds exhibit high antioxidant capacity and a wide range of health benefits as well as technologically promising properties. Given that, their recovery represents an attractive opportunity to valorize this by-product. In this work low thermal treatments were applied to alperujo in order to obtain phenol-enriched liquid fractions. Optimization assays combining different levels of temperature (30 to 90 ºC), time (60 to 180 min) and water content (70 to 90%), followed by response surface methodologies were performed. The results indicated that by applying optimal conditions, is possible to obtain theoretical yields of Total phenols, DHPG, HT and Ty of 2.4, 957.8, 3.4 and 6.4 times greater, respectively, than raw dry alperujo. Interestingly, all the evaluated conditions can be reproduced with low investment in a standard olive oil industry.Los fenoles hidrofÃlicos representan los principales compuestos bioactivos del alperujo. Los más relevantes son 3,4-Dihidroxifenilglicol (DHFG), Hidroxitirosol (HT) y Tirosol (Ti). Estos compuestos presentan alta capacidad antioxidante, beneficios para la salud e importantes propiedades tecnológicas, por ello su recuperación representa una alternativa para la valorización de este subproducto. En este trabajo, se aplicaron al alperujo tratamientos térmicos para obtener fracciones lÃquidas enriquecidas con compuestos fenólicos. Se realizaron ensayos combinando niveles de temperatura (30 ºC a 90 ºC), tiempo (60 min a 180 min) y humedad del alperujo (70 % a 90 %), seguidos de metodologÃas de superficie de respuesta. Los resultados indicaron que, mediante la aplicación de las condiciones óptimas, es posible obtener rendimientos teóricos de fenoles totales, DHFG, HT y Ti, 2.4, 957.8, 3.4 y 6.4 veces superiores a los obtenidos a partir del alperujo inicial. Es destacable que las condiciones establecidas, se pueden reproducir con bajo costo en una industria olivÃcola estándar
Bounds on the dipole moments of the tau-neutrino via the process in a 331 model
We obtain limits on the anomalous magnetic and electric dipole moments of the
through the reaction
and in the framework of a 331 model. We consider initial-state radiation, and
neglect and photon exchange diagrams. The results are based on the data
reported by the L3 Collaboration at LEP, and compare favorably with the limits
obtained in other models, complementing previous studies on the dipole moments.Comment: 13 pages, 4 figures, to be published in The European Physical J C.
arXiv admin note: substantial text overlap with arXiv:hep-ph/060527
The Triple Higgs Boson Self-Coupling at Future Linear e+e- Colliders Energies: ILC and CLIC
We analyzed the triple Higgs boson self-coupling at future
colliders energies, with the reactions . We evaluate the total cross-sections for both and ,
and calculate the total number of events considering the complete set of
Feynman diagrams at tree-level. We vary the triple coupling
within the range and +2. The numerical
computation is done for the energies expected to be available at a possible
Future Linear Collider with a center-of-mass energy and a luminosity 1000 . Our analysis is also extended to a
center-of-mass energy 3 and luminosities of 1000 and 5000
. We found that for the process , the
complete calculation differs only by 3% from the approximate calculation
, while for the process , the expected number of events, considering the decay products of both
and , is not enough to obtain an accurate determination of the triple Higgs
boson self-coupling.Comment: 19 pages, 12 figure
Desarrollo de un sistema fotogramétrico tridimensional computerizado no invasivo para el análisis de la columna vertebral humana
El presente trabajo expone el desarrollo de un sistema fotogramétri-
co tridimensional (3D) no invasivo basado en la utilización de
imágenes radiológicas que permite el análisis de la columna vertebral
humana para su aplicación en el ámbito de la investigctción
básica acerca del comportamiento de la columna y su utilización
práctica para facilitar el diagnóstico clÃnico en los centros médi-
-cos.
A pártir de Ia información obtenida mediante imágenes radio-
tógicai son aplicadas técnicas fotogramétricas 3D computerizadas
que permiten con una adecuada metodologÃa no invasiva la obtención
de diversos parámetros biomectÃnicos que permiten detetminar
el comportamiento estático y dinámico de la columna. Asimismo
se desarrollan ciertos algoritmos de representación gráfica tri-
dimensional de la columna vertebral humana que la simulan de
forma realista; esto puede suponer un avance importante para su
utilización en el perfeccionamiento del diagnóstico clÃnico. El sistema
desarrollado ha sido aplicado de forma práctica sobre una
muestra de pacientes afectados por diversos grados de escoliosis.Peer Reviewe
Energy and Exergy Analysis of Water-LiBr Absorption Systems with Adiabatic Absorbers for Heating and Cooling
AbstractSolar energy can be used to produce cold through absorption systems. In this study, the energy and exergy analysis on a single effect water-LiBr absorption facility is presented. The work is carried out for heating and cooling applications. Performance parameters are the coefficient of performance and exergy efficiency. The influence of operating temperatures on such parameters is included. An analysis of individual components is also presented. The most noticeable effect is observed for the case of exergy efficiency for absorber and generator. This parameter increases with an increase of absorption temperature. The opposite effect is observed when the generation temperature increases. Results obtained allow the identification of parameters that may influence the exergy efficiency of the adiabatic absorption system. The first candidate to optimize is the absorber, due to the lowest value of exergy efficiency obtained among all components of the system. For adiabatic absorbers, the recirculation ratio emerges as a new parameter. The solution heat exchanger is also susceptible to optimization
The impact of corporate social responsibility on consumer brand engagement and purchase intention at fashion retailers
Consumers have demonstrated new ways of engaging with fashion retailers and experiencing their brand values. This research aims to understand better how fashion consumers form their purchase intentions, by exploring how their expectations about corporate social responsibility influence consumer brand engagement and purchase intention. The research comprises two studies, using different methodologies. The first study is quantitative; it involved 1296 individuals and the results were analyzed using structural equation modeling. The second study is qualitative and utilizes expert opinions from the fashion industry; it seeks to derive managerial and practical implications from the findings of the first study. The results show that corporate social responsibility influences the purchase intention of fashion consumers, but mainly through brand engagement. Consequently, fashion companies should focus on building consumer trust in the sustainability initiatives of brands, including by utilizing local suppliers.Cátedra Extraordinaria de Comercio Universidad de Alcalá - Ayuntamiento de Madri
Restitución de Pterolepis grallata (Pantel, 1886) como especie válida y estatus taxonómico de las especies ibéricas del género (Orthoptera, Tettigoniidae)
The taxonomic status of the Iberian species of the genera Pterolepis Rambur, 1838 and Rhacocleis Fieber, 1853 is revised through the study of 126 specimens from different private and institutional collections. Pterolepis grallata (Pantel, 1886) is reinstated as a valid species as a result of morphological studies and phylogenetic analysis. The criterion of Willemse & Willemse (2005) not accepting the use of number of apical spurs of hind tibiae as a character for genera separation is followed, so that all Iberian species included up to now in these genera belong to genus Pterolepis.Se revisa la situación taxonómica de las especies ibéricas encuadradas en los géneros Pterolepis Rambur, 1838 y Rhacocleis Fieber, 1853 mediante el estudio de 126 ejemplares procedentes de diversas instituciones y colecciones. Se restituye Pterolepis grallata (Pantel, 1886) como especie válida en función del estudio morfológico y filogenético. Se acepta el criterio de Willemse & Willemse (2005), descartando la utilización de la espinación apical de las tibias posteriores como carácter para discriminar los géneros, por el que todas las especies ibéricas citadas hasta el momento en esos géneros, pertenecen al género Pterolepis
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