2,298 research outputs found
MarĂa Zambrano: recuerdo y vigencia (1904-2004)
El 18 de noviembre de 2004 se realizĂł en la Universidad AutĂłnoma un seminario sobre MarĂa Zambrano, organizado por el Departamento de FilosofĂa con la coordinaciĂłn de JosĂ© Luis Mora quien hizo la introducciĂłn a la vida de Zambrano. Bajo el tĂtulo Notas para una biografĂa. Los años de aprendizaje nos hablĂł de los tres aspectos más importantes que se deben tener en cuenta: su propia tradiciĂłn familiar, desde sus abuelos ya maestros de escuela, hasta sus padres, igualmente maestros en el mundo rural andaluz; los años que pasĂł en Segovia donde coincidiĂł con relevantes intelectuales entre los que destacĂł Antonio Machado y donde tuvo oportunidad de escuchar a los intelectuales más notables y de la Ă©poca; y su compromiso polĂtico propiciado por su propio padre y desarrollado al ďż˝calorďż˝ de los acontecimientos que tuvo ocasiĂłn de vivir en la universidad de los años 20
Dynamics of Scalar Field Dark Matter With a Cosh-like Potential
The dynamics of a cosmological model fueled by scalar field dark matter with
a cosh-like potential plus a cosmological constant is investigated in detail.
It is revealed that the late-time attractor is always the de Sitter solution,
and that, depending on the values of the free parameters, the oscillating
solution of the scalar field -- modeling cold dark matter -- mediates between
some early stage (say, the radiation-dominated solution) and the accelerating
de Sitter attractor.Comment: 9 pages, 17 figures, uses RevTe
Effect of preparation conditions on the polymorphism and transport properties of lanthanum molybdates
In this work, La6MoO12-based compounds were investigated as part of a new family of materials very competitive as hydrogen separation membranes [1,2].
La5.4MoO11.1 was synthesized by the freeze-drying precursor method and the calcination conditions were optimized in order to obtain single phases. Several cooling rates were applied and different polymorphs were obtained: a simple cubic fluorite symmetry (Fm-3m) for the sample cooled by quenching, and two different rhombohedral (R-3) space groups for the samples cooled at 50 ºC•min-1 and 0.5 ºC•min-1 (see Figure below). For the quenched sample, the Rietveld refinement was satisfactory in a Fm-3m space group. For the other two compositions no structural model was available and were indexed in a R-3 space group, however some small reflections were not given any intensity by the model used. Transmission electron microscopy confirmed the presence of superstructures for those samples. All ceramic materials were obtained with relative densities close to 100% after sintering at 1500 ºC. Stability studies demonstrated that all three polymorphs were stable in oxidizing and reducing conditions at 800 ºC for 48 hours.
The three samples present a significant proton contribution to the conductivity at temperatures lower than 800 ÂşC. These results were confirmed by thermogravimetric analysis. The highest conductivity values were observed for the samples prepared by quenching. The three polymorphs display a small p-type electronic contribution to the overall conductivity in oxidizing conditions and n-type electronic one in very reducing conditions, much more significant for the samples cooled by quenching and at 50 ÂşC•min-1.Universidad de Málaga. Campus de Excelencia Internacional AndalucĂa Tech
Migration, nostalgia and the building of a food imaginary: Mexican migrants at "La Pulga" market in San Joaquin Valley, California
In the context of transnational migration, ethnic markets function as segmented spaces where migrants as a group may be observed on many levels. Provisioning in the market (as much by immigrants as by natives or long-term residents) as well as the consumption of prepared food in situ compel a multiplicity of social interactions that facilitate knowledge and social relations, including recipes, memories, nostalgia, circulation of products and culinary techniques. In addition, a market can acquire a role as a meaningful transnational space of confluence for a system of relations and representations that help to decipher the complex social reality of subjects involved in a transnational migration phenomenon. With this paper we aim to highlight how a migratory context as well as the collectivization of a sensory experience as seen in an itinerant Mexican food market in California lead to the construction of a food imaginary related to Mexican food when it is disassociated from the original context in which it is produced. Thus, by means of an ethnographic approach, this paper aims to demonstrate how the collectivization of a sensory experience, framed under culinary nostalgia and triggered by the performativity and reflexivity of the subjects that take part in market activity, enables the construction of a food imaginary for the Mexican migrants that are regular clients of an itinerant market in California. (author's abstract
Cheese whey: a cost-effective alternative for hyaluronic acid production by Streptococcus zooepidemicus
This study focuses on the optimization of cheese whey formulated media for the production of hyaluronic acid HA by Streptococcus zooepidemicus. Culture media containing whey (W; 2.1 g/L) or whey hydrolysate (WH; 2.4 g/L) gave the highest HA productions. Both W and WH produced high yields on protein consumed, suggesting cheese whey is a good nitrogen source for S. zooepidemicus production of HA. Polysaccharide concentrations of 4.0 g/L and 3.2 g/L were produced in W and WH in a further scale-up to 5 L bioreactors, confirming the suitability of the low-cost nitrogen source. Cheese whey culture media provided high molecular weight (> 3000 kDa) HA products. This study revealed replacing the commercial peptone by the low-cost alternative could reduce HA production costs by up to a 70%compared to synthetic media.Isabel Rodriguez was funded by a postdoctoral contract from the Xunta de Galicia, Spain (Plan I2C, 2012). This research was financially supported by projects: MAT 2010-21509-C03-01 (Ministerio de Economia y Competitividad, Spain) and FP7 Project BiValBi. Biotechnologies to Valorise the regional food Biodiversity in Latin America (PIRSES-GA-2013-611493). The authors want to thank Benigno Pereira, the manager of Queizuar S.L. (A Coruna, Spain) for providing the cheese whey utilised to conduct this research. We also wish to thank Ana Duran and Margarita Nogueira (IIM-CSIC) for their excellent technical assistance
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