1,954 research outputs found
Predicción de la frescura del aceite de oliva virgen extra durante el almacenamiento mediante espectroscopía de fluorescencia
Virgin olive oil quality relates to flavor and unique health benefits. Some of these properties are
at the most desirable level when the oil is just extracted, since it is not a product that improves with age. On the
contrary, the concentrations of many compounds change during its shelf-life. These changes reveal the aging of
the oil but do not necessarily mean decay in sensory properties, so in some cases an aged oil from healthy olives
may be better qualified than a fresh one from olives affected by fermentation. The aim of this work is to analyze
different methodologies proposed for assessing the quality of virgin olive oil with implications in freshness and
aging of the oil, and to highlight the possibilities of rapid spectrofluorimetric techniques for assessing oil freshness by checking the evolution of pigments during storage. The observed change in the selected spectral features
and mathematical modelling over time was compared with the accepted model for predicting the amount of
pyropheophytin a, which is based on isokinetic studies. The best regression was obtained for 655 nm (adjustedR2
= 0.91) wavelength, which matches the distinctive band of pigments. The two mathematical models described
in this study highlight the usefulness of pigments in the prediction of the shelf-life of extra virgin olive oil.La calidad del aceite de oliva virgen está relacionada con su flavor y sus beneficios
únicos para la salud. Algunas de estas propiedades se encuentran en el nivel más deseable cuando el aceite está
recién extraído, ya que no es un producto que mejore con el tiempo. Por el contrario, las concentraciones de
muchos compuestos cambian a lo largo de la vida útil. Estos cambios revelan el envejecimiento del aceite, pero
no implican necesariamente la alteración de las propiedades sensoriales, por lo que en algunos casos un aceite
envejecido procedente de aceitunas sanas puede presentar mejor calidad que uno fresco procedente de aceitunas
afectadas por procesos de fermentación. El objetivo de este trabajo es estudiar diferentes metodologías propuestas para evaluar la calidad del aceite de oliva virgen con implicaciones en la frescura y el envejecimiento del
aceite, destacando las posibilidades de las rápidas técnicas espectrofluorométricas para evaluar la frescura del
aceite verificando la evolución de los pigmentos durante el almacenamiento. El cambio observado en las características espectrales seleccionadas y su modelado matemático a lo largo del tiempo se comparó con el modelo
aceptado para predecir la cantidad de pirofeofitina a, que se basa en estudios isocinéticos. Los dos modelos
matemáticos descritos en este estudio pusieron de manifiesto la utilidad de los pigmentos en la predicción de la
vida útil del aceite de oliva virgen extra. La mejor regresión se obtuvo para 655 nm (R2
-ajustado = 0,91), longitud de onda que coincide con la banda distintiva de pigmentos.Secretaría de Estado de Investigación, Desarrollo e Innovación de España-AGL2015-69320-
Predicción de la frescura del aceite de oliva virgen extra durante el almacenamiento mediante espectroscopía de fluorescencia
Virgin olive oil quality relates to flavor and unique health benefits. Some of these properties are
at the most desirable level when the oil is just extracted, since it is not a product that improves with age. On the
contrary, the concentrations of many compounds change during its shelf-life. These changes reveal the aging of
the oil but do not necessarily mean decay in sensory properties, so in some cases an aged oil from healthy olives
may be better qualified than a fresh one from olives affected by fermentation. The aim of this work is to analyze
different methodologies proposed for assessing the quality of virgin olive oil with implications in freshness and
aging of the oil, and to highlight the possibilities of rapid spectrofluorimetric techniques for assessing oil freshness by checking the evolution of pigments during storage. The observed change in the selected spectral features
and mathematical modelling over time was compared with the accepted model for predicting the amount of
pyropheophytin a, which is based on isokinetic studies. The best regression was obtained for 655 nm (adjustedR2
= 0.91) wavelength, which matches the distinctive band of pigments. The two mathematical models described
in this study highlight the usefulness of pigments in the prediction of the shelf-life of extra virgin olive oil.La calidad del aceite de oliva virgen está relacionada con su flavor y sus beneficios
únicos para la salud. Algunas de estas propiedades se encuentran en el nivel más deseable cuando el aceite está
recién extraído, ya que no es un producto que mejore con el tiempo. Por el contrario, las concentraciones de
muchos compuestos cambian a lo largo de la vida útil. Estos cambios revelan el envejecimiento del aceite, pero
no implican necesariamente la alteración de las propiedades sensoriales, por lo que en algunos casos un aceite
envejecido procedente de aceitunas sanas puede presentar mejor calidad que uno fresco procedente de aceitunas
afectadas por procesos de fermentación. El objetivo de este trabajo es estudiar diferentes metodologías propuestas para evaluar la calidad del aceite de oliva virgen con implicaciones en la frescura y el envejecimiento del
aceite, destacando las posibilidades de las rápidas técnicas espectrofluorométricas para evaluar la frescura del
aceite verificando la evolución de los pigmentos durante el almacenamiento. El cambio observado en las características espectrales seleccionadas y su modelado matemático a lo largo del tiempo se comparó con el modelo
aceptado para predecir la cantidad de pirofeofitina a, que se basa en estudios isocinéticos. Los dos modelos
matemáticos descritos en este estudio pusieron de manifiesto la utilidad de los pigmentos en la predicción de la
vida útil del aceite de oliva virgen extra. La mejor regresión se obtuvo para 655 nm (R2
-ajustado = 0,91), longitud de onda que coincide con la banda distintiva de pigmentos.Secretaría de Estado de Investigación, Desarrollo e Innovación de España-AGL2015-69320-
Virtual Processes and Superradiance in Spin-Boson Models
We consider spin-boson models composed by a single bosonic mode and an
ensemble of identical two-level atoms. The situation where the coupling
between the bosonic mode and the atoms generates real and virtual processes is
studied, where the whole system is in thermal equilibrium with a reservoir at
temperature . Phase transitions from ordinary fluorescence to
superradiant phase in three different models is investigated. First a model
where the coupling between the bosonic mode and the atom is via the
pseudo-spin operator is studied. Second, we investigate the
generalized Dicke model, introducing different coupling constants between the
single mode bosonic field and the environment, and for rotating
and counter-rotating terms, respectively. Finally it is considered a modified
version of the generalized Dicke model with intensity-dependent coupling in the
rotating terms. In the first model the zero mode contributes to render the
canonical entropy a negative quantity for low temperatures. The last two models
presents phase transitions, even when only Hamiltonian terms which generates
virtual processes are considered
Predicción de la frescura del aceite de oliva virgen extra durante el almacenamiento mediante espectroscopía de fluorescencia
Virgin olive oil quality relates to flavor and unique health benefits. Some of these properties are at the most desirable level when the oil is just extracted, since it is not a product that improves with age. On the contrary, the concentrations of many compounds change during its shelf-life. These changes reveal the aging of the oil but do not necessarily mean decay in sensory properties, so in some cases an aged oil from healthy olives may be better qualified than a fresh one from olives affected by fermentation. The aim of this work is to analyze different methodologies proposed for assessing the quality of virgin olive oil with implications in freshness and aging of the oil, and to highlight the possibilities of rapid spectrofluorimetric techniques for assessing oil freshness by checking the evolution of pigments during storage. The observed change in the selected spectral features and mathematical modelling over time was compared with the accepted model for predicting the amount of pyropheophytin a, which is based on isokinetic studies. The best regression was obtained for 655 nm (adjusted-R2 = 0.91) wavelength, which matches the distinctive band of pigments. The two mathematical models described in this study highlight the usefulness of pigments in the prediction of the shelf-life of extra virgin olive oil.La calidad del aceite de oliva virgen está relacionada con su flavor y sus beneficios únicos para la salud. Algunas de estas propiedades se encuentran en el nivel más deseable cuando el aceite está recién extraído, ya que no es un producto que mejore con el tiempo. Por el contrario, las concentraciones de muchos compuestos cambian a lo largo de la vida útil. Estos cambios revelan el envejecimiento del aceite, pero no implican necesariamente la alteración de las propiedades sensoriales, por lo que en algunos casos un aceite envejecido procedente de aceitunas sanas puede presentar mejor calidad que uno fresco procedente de aceitunas afectadas por procesos de fermentación. El objetivo de este trabajo es estudiar diferentes metodologías propuestas para evaluar la calidad del aceite de oliva virgen con implicaciones en la frescura y el envejecimiento del aceite, destacando las posibilidades de las rápidas técnicas espectrofluorométricas para evaluar la frescura del aceite verificando la evolución de los pigmentos durante el almacenamiento. El cambio observado en las características espectrales seleccionadas y su modelado matemático a lo largo del tiempo se comparó con el modelo aceptado para predecir la cantidad de pirofeofitina a, que se basa en estudios isocinéticos. Los dos modelos matemáticos descritos en este estudio pusieron de manifiesto la utilidad de los pigmentos en la predicción de la vida útil del aceite de oliva virgen extra. La mejor regresión se obtuvo para 655 nm (R2-ajustado = 0,91), longitud de onda que coincide con la banda distintiva de pigmentos
The LHC Logging Service : Handling terabytes of on-line data
Based on previous experience with LEP, a long-term data logging service for the LHC was developed and put in place in 2003, several years before beam operation. The scope of the logging service covers the evolution over time of data acquisitions on accelerator equipment and beam related parameters. The intention is to keep all this time-series data on-line for the lifetime of LHC, allowing easy data comparisons with previous years. The LHC hardware commissioning has used this service extensively prior to the first beams in 2008 and even more so in 2009. Current data writing rates exceed 15TB/year and continue to increase. The high data volumes and throughput rates, in writing as well as in reading, require special arrangements on data organization and data access methods
The star formation history of the Local Group dwarf elliptical galaxy NGC 185: II. Gradients in the stellar population
The star formation history of the dE NGC 185, together with its spatial
variations, has been investigated using new ground-based and
photometry, and synthetic color--magnitude diagrams (CMDs). We find that the
bulk of the stars were formed in NGC 185 at an early epoch of its evolution.
After that, the star formation proceeded at a low rate until the recent past,
the age of the most recent traces of star formation activity detected in the
galaxy being some 100 Myr.
The star formation rate, for old and intermediate ages shows a
gradient in the sense of taking smaller values for higher galactocentric radii.
Moreover, recent star formation is detected in the central
pc only, where the youngest, 100 Myr old population is
found. The luminous blue {\it stars} discovered by Baade (1951) in the center
of NGC 185 are discussed using new CCD images in and Baade's original
photographic plates, reaching the conclusion that most of them are in fact star
clusters. A consistent picture arises in which the gas observed in the central
region of NGC 185 would have an internal origin. The rate at which evolved
stars return gas to the ISM is enough to seed the recent star formation
observed in the center of the galaxy and the SN rate is probably low enough to
allow the galaxy to retain the gas not used in the new stellar generations.Comment: 34 pages, 17 figures, 5 Tables, to be published in AJ October 9
Phase Diagram of Multilayer Magnetic Structures
Multilayer "ferromagnet-layered antiferromagnet" (Fe/Cr) structures
frustrated due to the roughness of layer interfaces are studied by numerical
modeling methods. The "thickness-roughness" phase diagrams for the case of thin
ferromagnetic film on the surface of bulk antiferromagnet and for two
ferromagnetic layers separated by an antiferromagnetic interlayer are obtained
and the order parameter distributions for all phases are found. The phase
transitions nature in such systems is considered. The range of applicability
for the "magnetic proximity model" proposed by Slonczewski is evaluated.Comment: 8 pages, 8 figure
Professional Expectations of Provider LGBTQ Competence: Where We Are and Where We Need to Go
Introduction: Mental and behavioral health professional organizations use their governing documents to set expectations of provider competence in working with LGBTQ+ clients.
Method: The codes of ethics and training program accreditation guidelines of nine mental and behavioral health disciplines (n=16) were analyzed using template analysis.
Results: Coding resulted in fives themes: mission and values, direct practice, clinician education, culturally competent professional development, and advocacy. Expectations for provider competency vary greatly across disciplines.
Conclusion: Having a mental and behavioral health workforce that is uniformly competent in meeting the unique needs of LGBTQ populations is key for supporting the mental and behavioral health of LGBTQ persons.This work was supported by the University of Maryland Prevention Research Center cooperative agreement from the Centers for Disease Control and Prevention (grant U48DP006382). N.D.W. also acknowledges support from the Southern Regional Education Board and the Robert Wood Johnson Foundation Health Policy Research Scholars Program. J.N.F. also acknowledges support from the Maryland Population Research Center, by the Eunice Kennedy Shriver National Institute of Child Health and Human Development (grant P2CHD041041). This work does not expressly represent the views of the Centers for Disease Control and Prevention, National Institutes of Health, or the Robert Wood Johnson Foundation
Predicting extra virgin olive oil freshness during storage by fluorescence spectroscopy
Virgin olive oil quality relates to flavor and unique health benefits. Some of these properties are at the most desirable level when the oil is just extracted, since it is not a product that improves with age. On the contrary, the concentrations of many compounds change during its shelf-life. These changes reveal the aging of the oil but do not necessarily mean decay in sensory properties, so in some cases an aged oil from healthy olives may be better qualified than a fresh one from olives affected by fermentation. The aim of this work is to analyze different methodologies proposed for assessing the quality of virgin olive oil with implications in freshness and aging of the oil, and to highlight the possibilities of rapid spectrofluorimetric techniques for assessing oil freshness by checking the evolution of pigments during storage. The observed change in the selected spectral features and mathematical modelling over time was compared with the accepted model for predicting the amount of pyropheophytin a, which is based on isokinetic studies. The best regression was obtained for 655 nm (adjusted-R2 = 0.91) wavelength, which matches the distinctive band of pigments. The two mathematical models described in this study highlight the usefulness of pigments in the prediction of the shelf-life of extra virgin olive oil
An Instanton Toolbox for F-Theory Model Building
Several dimensionful parameters needed for model building can be engineered
in a certain class of SU(5) F-theory GUTs by adding extra singlet fields which
are localized along pairwise intersections of D7-branes. The values of these
parameters, however, depend on dynamics external to the GUT which causes the
singlets to acquire suitable masses or expectation values. In this note, we
demonstrate that D3-instantons which wrap the same 4-cycle as one of the
intersecting D7's can provide precisely the needed dynamics to generate several
important scales, including the supersymmetry-breaking scale and the
right-handed neutrino mass. Furthermore, these instantons seem unable to
directly generate the \mu term suggesting that, at least in this class of
models, it should perhaps be tied to one of the other scales in the problem.
More specifically, we study the simple system consisting of a pair of D7-branes
wrapping del Pezzo surfaces which intersect along a curve of genus 0
or 1 and classify all instanton configurations which can potentially contribute
to the superpotential. This allows one to formulate topological conditions
which must be imposed on \Sigma for various model-building applications. Along
the way, we also observe that the construction of arXiv:0808.1286 which
engineers a linear superpotential in fact realizes an O'Raifeartaigh model at
the KK scale whose 1-loop Coleman-Weinberg potential generically leads to a
metastable, long-lived SUSY-breaking vacuum.Comment: 18 pages, 2 figures; v2: updated to reflect corrections in v2 of
0808.128
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