35 research outputs found
Influencia del tipo de derivado celulósico sobre la textura y la estabilidad oxidativa y térmica de oleogeles de aceite de soja
The use oleogels (defined as edible oils entrapped in a three-dimensional network employing a self-assembled structuring agent) has recently been proposed to replace saturated fat or trans-fats in foods. In this work the effects of different cellulose derivative mixtures (Avicel, ethyl cellulose and α-cellulose) on lipid stability, glass transition temperature and the texture of soybean oil oleogels were determined by employing a mixture design approach. Avicel affected lipid stability, increasing the oxidative rancidity and peroxide values of oleogels. Oleogels with higher proportions of Avicel also presented higher transition temperatures. A higher percent of ethyl cellulose and α-cellulose in the oleogel mixture resulted in a more stable system with lower oil rancidity and lower glass transition temperatures. In addition, Avicel resulted in a softer and less tacky texture, an important characteristic to consider for food applications.Recientemente, ha sido propuesto el uso de oleogeles (definido como aceites comestibles atrapados en una red tridimensional que ocupa un agente estructurante de auto-ensamblado) como substituto de grasa saturada o grasas trans en alimentos. En este trabajo el efecto de mezclas de diferentes derivados celulósicos (Avicel, etil celulosa y α-celulosa) sobre la estabilidad de lípidos, temperaturas de transición térmica y textura de oleogeles de aceite de soja fueron determinados utilizando un diseño de mezclas. Avicel afectó la estabilidad de lípidos, aumentando la rancidez oxidativa y valores de peróxido en los oleogeles. Oleogeles con mayores proporciones de Avicel también presentaron temperaturas de transición térmica más altas. Porcentajes más altos de etil celulosa y α-celulosa resultaron en un sistema más estable con menor rancidez oxidativa y menores temperaturas de transición térmica. Sin embargo, Avicel resultó en una textura más suave y menos pegajosa, una característica importante a considerar para su aplicación en alimentos
Influence of the type of cellulosic derivatives on the texture, and oxidative and thermal stability of soybean oil oleogel
The use oleogels (defined as edible oils entrapped in a three-dimensional network employing a self-assembled structuring agent) has recently been proposed to replace saturated fat or trans-fats in foods. In this work the effects of different cellulose derivative mixtures (Avicel, ethyl cellulose and α-cellulose) on lipid stability, glass transition temperature and the texture of soybean oil oleogels were determined by employing a mixture design approach. Avicel affected lipid stability, increasing the oxidative rancidity and peroxide values of oleogels. Oleogels with higher proportions of Avicel also presented higher transition temperatures. A higher percent of ethyl cellulose and α-cellulose in the oleogel mixture resulted in a more stable system with lower oil rancidity and lower glass transition temperatures. In addition, Avicel resulted in a softer and less tacky texture, an important characteristic to consider for food applications.<br><br>Recientemente, ha sido propuesto el uso de oleogeles (definido como aceites comestibles atrapados en una red tridimensional que ocupa un agente estructurante de auto-ensamblado) como substituto de grasa saturada o grasas trans en alimentos. En este trabajo el efecto de mezclas de diferentes derivados celulósicos (Avicel, etil celulosa y α-celulosa) sobre la estabilidad de lípidos, temperaturas de transición térmica y textura de oleogeles de aceite de soja fueron determinados utilizando un diseño de mezclas. Avicel afectó la estabilidad de lípidos, aumentando la rancidez oxidativa y valores de peróxido en los oleogeles. Oleogeles con mayores proporciones de Avicel también presentaron temperaturas de transición térmica más altas. Porcentajes más altos de etil celulosa y α-celulosa resultaron en un sistema más estable con menor rancidez oxidativa y menores temperaturas de transición térmica. Sin embargo, Avicel resultó en una textura más suave y menos pegajosa, una característica importante a considerar para su aplicación en alimentos
Extensions of Superscaling from Relativistic Mean Field Theory: the SuSAv2 Model
We present a systematic analysis of the quasielastic scaling functions
computed within the Relativistic Mean Field (RMF) Theory and we propose an
extension of the SuperScaling Approach (SuSA) model based on these results. The
main aim of this work is to develop a realistic and accurate phenomenological
model (SuSAv2), which incorporates the different RMF effects in the
longitudinal and transverse nuclear responses, as well as in the isovector and
isoscalar channels. This provides a complete set of reference scaling functions
to describe in a consistent way both processes and the
neutrino/antineutrino-nucleus reactions in the quasielastic region. A
comparison of the model predictions with electron and neutrino scattering data
is presented.Comment: 19 pages, 24 figure
Cultura organizacional e BSC: proposta para implementar numa PME
Objetivo: os bons resultados que a aplicação do Balanced Scorecard (BSC) tem produzido em grandes empresas em vários países levaram-nos a considerar útil e possível estendê-lo, com as necessárias adaptações, a uma pequena e média empresa (PME), de natureza familiar, que, considerando as suas características específicas, como o tamanho e a cultura organizativa, apresenta grande carência de um sistema de gestão baseado numa visão estratégica que lhe facilite a planificação e o controlo do negócio. Neste sentido, este estudo desenvolve-se com o propósito de apresentar uma proposta de aplicação do BSC capaz de demonstrar a sua utilidade numa PME.
Metodologia: qualitativa, por se considerar a mais enquadrada com o estudo de fenómenos subjetivos e a que mais privilegia uma posição crítica do investigador, com recurso ao estudo de caso descritivo e explicativo e aos questionários, com base no método Delphi, para a recolha de dados.
Resultados: o trabalho realizado permitiu concluir que a evolução de uma organização é lenta e contínua, mas que o simples exercício de se equacionar a possibilidade de se proceder à implementação de uma ferramenta com as características do BSC desencadeia, por si só, um processo de mudança, ao ajudar a equipa de trabalho a entender que as causas dos problemas têm conexão com questões estratégicas e que as suas ações devem ser conduzidas no médio e longo prazo.info:eu-repo/semantics/publishedVersio
MOVIMIENTO DE DISPERSIÓN DE Cochliomyia hominivorax (Coquerel) DIPTERA: CALLIPHORIDAE) EN EL PARQUE NATURAL METROPOLITANO ENTRE 1996-1997
Un estudio fue llevado a cabo en el Parque Natural Metropolitano con el propósito de determinar el movimiento de dispersión de la mosca del gusano barrenador, Cochliomyia hominivorax, dentro el bosque. Asimismo, se determinó entre septiembre de 1996 a abril
de 1997 la distribución poblacional, la actividad diaria y el efecto de los parámetros físicos sobre estas moscas. Para esto se colocaron tres sitios de colecta, dos dentro y uno en el borde del bosque, empleando hígado de res como atrayente. La temperatura y la velocidad
del viento fueron medidas en el momento de la captura de cada mosca. Un total de 305 moscas fueron capturadas en 74 días de colecta con un promedio de 3.1 5.33 moscas por día. Durante la estación seca se colectó significativamente mayor cantidad de moscas que en la temporada lluviosa. La temperatura media y velocidad del viento promedio en la cual se capturaron estas moscas fueron de 29.7 2.2ºC y 0.47 1.51 Km/h, respectivamente. La temperatura media de captura se correlacionó positivamente y la precipitación
negativamente con el número de moscas capturadas. El puesto 2 fue donde se capturó significativamente mayor cantidad de moscas. Estas moscas presentaron mayor actividad durante las horas de la mañana entre las 10:00 y 11:00 a.m., con otro pico más pequeño entre las 3:00 y 4:00 p.m. De las 305 moscas colectadas, 27 fueron recapturadas, siendo el puesto 2 el que presentó un número significativamente mayor de moscas. Además, este fue el sitio que contribuyó con mayor número de moscas hacia los demás puestos. Nuestros resultados indican una baja población de esta especie en el Parque Natural Metropolitano (PNM), con una baja tasa de recaptura. Esto probablemente, está relacionado con el movimiento de los mamíferos silvestres en el área y las características peculiares de este hábitat
Robust modeling of human contact networks across different scales and proximity-sensing techniques
The problem of mapping human close-range proximity networks has been tackled
using a variety of technical approaches. Wearable electronic devices, in
particular, have proven to be particularly successful in a variety of settings
relevant for research in social science, complex networks and infectious
diseases dynamics. Each device and technology used for proximity sensing (e.g.,
RFIDs, Bluetooth, low-power radio or infrared communication, etc.) comes with
specific biases on the close-range relations it records. Hence it is important
to assess which statistical features of the empirical proximity networks are
robust across different measurement techniques, and which modeling frameworks
generalize well across empirical data. Here we compare time-resolved proximity
networks recorded in different experimental settings and show that some
important statistical features are robust across all settings considered. The
observed universality calls for a simplified modeling approach. We show that
one such simple model is indeed able to reproduce the main statistical
distributions characterizing the empirical temporal networks
Carnegie Supernova Project: The First Homogeneous Sample of Super-Chandrasekhar-mass/2003fg-like Type Ia Supernovae
We present a multiwavelength photometric and spectroscopic analysis of 13 super-Chandrasekhar-mass/2003fg-like Type Ia supernovae (SNe Ia). Nine of these objects were observed by the Carnegie Supernova Project. The 2003fg-like SNe have slowly declining light curves (Δm 15(B) < 1.3 mag), and peak absolute B-band magnitudes of -19 < M B < -21 mag. Many of the 2003fg-like SNe are located in the same part of the luminosity-width relation as normal SNe Ia. In the optical B and V bands, the 2003fg-like SNe look like normal SNe Ia, but at redder wavelengths they diverge. Unlike other luminous SNe Ia, the 2003fg-like SNe generally have only one i-band maximum, which peaks after the epoch of the B-band maximum, while their near-IR (NIR) light-curve rise times can be ⪆40 days longer than those of normal SNe Ia. They are also at least 1 mag brighter in the NIR bands than normal SNe Ia, peaking above M H = -19 mag, and generally have negative Hubble residuals, which may be the cause of some systematics in dark-energy experiments. Spectroscopically, the 2003fg-like SNe exhibit peculiarities such as unburnt carbon well past maximum light, a large spread (8000-12,000 km s-1) in Si ii λ6355 velocities at maximum light with no rapid early velocity decline, and no clear H-band break at +10 days. We find that SNe with a larger pseudo-equivalent width of C ii at maximum light have lower Si ii λ6355 velocities and more slowly declining light curves. There are also multiple factors that contribute to the peak luminosity of 2003fg-like SNe. The explosion of a C-O degenerate core inside a carbon-rich envelope is consistent with these observations. Such a configuration may come from the core-degenerate scenario.Fil: Ashall, C.. University Hawaii Institute For Astronomy; Estados UnidosFil: Lu, J.. Florida State University; Estados UnidosFil: Hsiao, E. Y.. Florida State University; Estados UnidosFil: Hoeflich, P.. Florida State University; Estados UnidosFil: Phillips, M. M.. Las Campanas Observatory; ChileFil: Galbany, Lluís. Instituto de Ciencias del Espacio; EspañaFil: Burns, C. R.. Las Campanas Observatory; ChileFil: Contreras, C.. Las Campanas Observatory; ChileFil: Krisciunas, K.. Texas A&M University; Estados UnidosFil: Morrell, Nidia Irene. Las Campanas Observatory; ChileFil: Stritzinger, M. D.. University Aarhus; DinamarcaFil: Suntzeff, Nicholas B.. Texas A&M University; Estados UnidosFil: Taddia, F.. University Aarhus; DinamarcaFil: Anais, J.. Las Campanas Observatory; ChileFil: Baron, E.. Oklahoma State University; Estados Unidos. Universitat Hamburg; AlemaniaFil: Brown, P. J.. Texas A&M University; Estados UnidosFil: Busta, L.. Las Campanas Observatory; ChileFil: Campillay, A.. Universidad de La Serena; ChileFil: Castellón, S.. Las Campanas Observatory; ChileFil: Corco, C.. Las Campanas Observatory; Chile. Soar Telescope; ChileFil: Davis, S.. University of California at Davis; Estados UnidosFil: Folatelli, Gaston. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Förster, F.. Universidad de Chile; Chile. Instituto Milenio de Astrofísica; ChileFil: Freedman, W. L.. University of Chicago; Estados UnidosFil: Gonzaléz, C.. Las Campanas Observatory; ChileFil: Hamuy, M.. Universidad de Chile; ChileFil: Holmbo, S.. University Aarhus; DinamarcaFil: Kirshner, R. P.. Harvard-Smithsonian Center for Astrophysics; Estados UnidosFil: Kumar, S.. Florida State University; Estados UnidosFil: Marion, G. H.. University of Texas at Austin; Estados UnidosFil: Mazzali, P.. Liverpool John Moores University; Reino UnidoFil: Morokuma, T.. The University Of Tokyo; JapónFil: Nugent, P. E.. Lawrence Berkeley National Laboratory; Estados Unidos. University of California at Berkeley; Estados UnidosFil: Persson, S. E.. Las Campanas Observatory; ChileFil: Piro, A. L.. Las Campanas Observatory; ChileFil: Roth, M.. Las Campanas Observatory; ChileFil: Salgado, F.. Las Campanas Observatory; ChileFil: Sand, D.J.. University of Arizona; Estados UnidosFil: Seron, J.. Las Campanas Observatory; ChileFil: Shahbandeh, M.. Florida State University; Estados UnidosFil: Shappee, B. J.. University Hawaii Institute For Astronomy; Estados Unido
Estudo fitoquímico de folhas de Solanum lycocarpum A. St.-Hil (Solanaceae) e sua aplicação na alelopatia
(Phytochemistry of Solanum lycocarpum A.St.–Hil (Solanaceae) leaves and their application in allelopathy). Solanum
lycocarpum A.St.-Hil (Solanaceae) is a typical shrub in the Cerrado of central Brazil. The allelopathic activity of aqueous extracts of the leaves and fruits of this species has already been proven in previous studies. The goal of this work was to verify the allelopathic activity of different leaf extracts of S. lycocarpum on the germination and growth of four target species. The leaves were collected, dried, triturated and submitted to two distinct methods of extraction: 1- liquid--liquid (ethyl acetate and dichloromethane) from the aqueous extract and 2- with solvents of increasing polarities (hexane, dichloromethane, ethyl acetate, acetone, methanol and water) directly from the leaves. Each extraction was made with ultrasound equipment for one hour, filtered and evaporated. From these extracts, solutions of 800, 400 and 200 ppm were prepared, and water and Logran® were used as positive and negative controls, respectively. Each solution, as well as the controls, was dissolved in DMSO for the bioassays. The target species used were lettuce, watercress, tomato and onion. To each plate, 20 seeds were added and 1 mL of the tested solutions (with 4 repetitions). The plates were incubated at 25 oC without light, and the shoots and roots of the seedlings were then measured and the percentage of germination and the inhibition of each extract were calculated. Tomato was the most sensitive to the extracts, followed by watercress, onion and lettuce. The extracts with stronger activity were AcOEt, acetone and the liquid-liquid extraction, indicating the fractions that may contain the active principles of the leaves in this species