Soy protein enzymatic hydrolysis and polysaccharides interactions: differential performance on kinetic adsorption at air-water interface

The objective of the work was to study the impact of soy protein hydrolysis on kinetic adsorption to the air-water interface and the effect of polysaccharides addition. Was used soy protein (SP) and theirs hydrolysates of 2% (H1) and 5.4% (H2) degree of hydrolysis. The polysaccharides (PS) used were a surface active one called E4M and a non-surface active one, lamda carrageenan (C). The dynamic surface pressure of interfacial films was evaluated with a drop tensiometer. In this contribution, we have determined the kinetic parameters of adsorption to the air-water interface which determined the penetration (Kp) and rearrangement (Kr) rates of SP, H1, H2 and PS, as well as their mixed systems. It was observed an increase of Kp and Kr when the protein were hydrolyzed (from SP to H1), however, when degree of hydrolysis progresses to H2 the parameters decreased again. In other hand, considerable differences were not found between these two PS studied concerning the Kp to air-water interface at these conditions. In spite of the different surface active nature of the PS, the proteins seem to control the behavior of the protein-PS interactions. However, when Kr of mixed systems was analyzed, the degree of hydrolysis and PS nature started to have a huge importance. Hence, it could be observed synergic or antagonic effects on Kr of biopolymers at liquid interface depending to the degree of hydrolysis of protein analyzed and the type of PS selected.CYTED through project 105PI0274CYCYT through grant AGL2007-60045Junta de Andalucía through grant PO6-AGR-01535Universidad de Buenos Aires, Agencia Nacional de Promoción Científica y Tecnológica (PICT 2008-1901) and Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentin

Introducing Type-2 Fuzzy Sets for Image Texture Modelling

In this paper, the texture property ”coarseness” is modeled by means of type-2 fuzzy sets, relating representative coarseness measures (our reference set) with the human perception of this texture property. The type-2 approach allows to face both the imprecision in the interpretation of the measure value and the uncertainty about the coarseness degree associated to a measure value. In our study, a wide variety of measures is analyzed, and assessments about coarseness perception are collected from pools. This information is used to obtain type-2 fuzzy sets where the secondary fuzzy sets are modelled by means of triangular membership functions fitted to the collected data

Estudio de la influencia de la calidad del agua de riego sobre las propiedades bioquímicas del suelo

Trabajo presentado en el VII Simposio Nacional sobre Control de la Degradación y Restauración de Suelos, celebrado en Bilbao, España, del 23 al 26 de junio de 2015Este estudio analiza la influencia de la calidad del agua de riego sobre los parámetros bioquímicos de los Fluvisoles calcáricos representativos en dos zonas del sur de Alicante. Mediante un análisis de componentes principales (ACP) se obtuvo el PC1 (40% variabilidad), referente a la salinidad, siendo útil para diferenciar ambas zonas de estudio, y el PC2 (31%), englobando los parámetros bioquímicos, que distingue las muestras en función de la profundidad. Sin embargo, no se ha observado un efecto negativo sobre las principales actividades enzimáticas en el área más afectada por la salinización.Peer Reviewe

Los exámenes de Física en la enseñanza por transmisión y en la enseñanza por investigación

In this paper we show the results of a comparative ancilysis between ordinary tests of Physics and Chemistry and the ones used from a constructivist view. The study is focused in two aspects: firstly, it aims to show that the constructivist conception of leaming imposes considerable modifications in the tests content; secondly it highlights the deficiencies found in the tests designed after constructivist teaching. These deficiencies will just be solved by an investigation mainly aimed to assessment transformation

Flamelet structures in spray ignition

In typical liquid-fueled burners the fuel is injected as a high-velocity liquid jet that breaks up to form the spray. The initial heating and vaporization of the liquid fuel rely on the relatively large temperatures of the sourrounding gas, which may include hot combustion products and preheated air. The heat exchange between the liquid and the gas phases is enhanced by droplet dispersion arising from the turbulent motion. Chemical reaction takes place once molecular mixing between the fuel vapor and the oxidizer has occurred in mixing layers separating the spray flow from the hot air stream. Since in most applications the injection velocities are much larger than the premixed-flame propagation velocity, combustion stabilization relies on autoignition of the fuel-oxygen mixture, with the combustion stand-off distance being controlled by the interaction of turbulent transport, droplet heating and vaporization, and gas-phase chemical reactions. In this study, conditions are identified under which analyses of laminar flamelets canshed light on aspects of turbulent spray ignition. This study extends earlier fundamental work by Liñan & Crespo (1976) on ignition in gaseous mixing layers to ignition of sprays. Studies of laminar mixing layers have been found to be instrumental in developing un-derstanding of turbulent combustion (Peters 2000), including the ignition of turbulent gaseous diffusion flames (Mastorakos 2009). For the spray problem at hand, the configuration selected, shown in Figure 1, involves a coflow mixing layer formed between a stream of hot air moving at velocity UA and a monodisperse spray moving at velocity USUA. The boundary-layer approximation will be used below to describe the resulting sl ender flow, which exhibits different igniting behaviors depending on the characteristics of t he fuel. In this approximation, consideration of the case U A = U S enables laminar ignition distances to be related to ignition times of unstrained spray flamelets, thereby pro viding quantitative information of direct applicability in regions of low scala r dissipation-rate in turbulent reactive flows (see the discussion in pp. 181–186 of Peters (2000)) . This report is organized as follows. Effects of droplet dispersion dynamics on ignition of sprays in turbulent mixing layers are discussed in Section 2. The formulation f or ignition in laminar mixing layers is outlined in Sections 3 and 4. The results are presented in Section 5. In Section 6, the mixture-fraction field and associated scalar dissipat ion rates for spray ignition are discussed. Finally, some brief conclusions are drawn in Section 7

Experimental determination of the absorption strength in absorbing chaotic cavities

Due to the experimental necessity we present a formula to determine the absorption strength by power losses inside a chaotic system (cavities, graphs, acoustic resonators, etc) when the antenna coupling, always present in experimental measurements, is taken into account. This is done by calculating the average of the absorption coefficient as a function of the absorption strength and the coupling of the antenna to the system, in the one channel case.Comment: 6 pages, 3 figures, Submitted to Phys. Rev.

Instagram as a participatory tool: A comparative analysis of six Spanish museums

Digital media is usually understood as a tool that helps the social and participatory ideal of museums and cultural institutions to materialize. This ideal has its roots in the reflections that, since the 1980s, new museology and critical museology movements have developed around the renewal of cultural organizations: a transformation that places the visitor at the center of the institution, revises their stories about its collections and invites institutions to be more participative with the public. Seeking to identify the characteristics that these theories adopt in practice, this article investigates the forms of participation implemented on Instagram by six Spanish cultural institutions: Museo Nacional del Prado Museum, Museo Nacional Thyssen-Bornemisza, Museo Nacional Reina Sofía, Museo Guggenheim Bilbao, Museo de Arte Contemporáneo de Barcelona (MACBA) and Centro de Cultura Contemporánea de Barcelona (CCCB). By way of a content analysis of their publications over the span of 6 months, patterns and trends have been identified within the communication strategies of these organizations. The results indicate a clear predominance of minimalist participatory forms (those oriented towards access to practical information and the discovery of collections) over maximalist modalities related to collaboration or co-creation. In general terms, there is also a considerable presence of audiovisual formats in the publications analyzed, showing the great capacity of these institutions to adapt to the latest changes in Instagram.Los medios digitales suelen entenderse como una herramienta que contribuye a materializar el ideal social y participativo de museos e instituciones culturales. Este ideal hunde sus raíces en las reflexiones que, desde los años ochenta, la nueva museología y la museología crítica han desarrollado sobre la renovación de las organizaciones culturales: una transformación que coloca al visitante en un lugar central de la institución, revisa los relatos sobre sus colecciones y se inclina a una mayor participación de los públicos. Buscando identificar las características de esta filosofía en la práctica, este artículo analiza las formas de participación implementadas en Instagram por seis instituciones culturales de referencia: el Museo del Prado, el Museo Thyssen-Bornemisza, el Museo Nacional Reina Sofía, el Museo Guggenheim Bilbao, el Museo de Arte Contemporáneo de Barcelona (MACBA) y el Centro de Cultura Contemporánea de Barcelona (CCCB). Mediante un análisis de contenido de sus publicaciones en Instagram durante 6 meses, se han identificado patrones y tendencias dentro de sus estrategias comunicativas. Los resultados indican un predominio de formas participativas minimalistas (orientadas al acceso a información práctica y el descubrimiento de las colecciones) frente a modalidades maximalistas de participación vinculadas a la colaboración o la cocreación. También se observa una considerable presencia de formatos audiovisuales en las publicaciones que pone de manifiesto la capacidad de adaptación de estas instituciones a los recientes cambios de Instagram y su creciente priorización de los vídeos de corta duración (Reels)