Efficient and reliable nonlocal damage models

We present an efficient and reliable approach for the numerical modelling of failure with nonlocal damage models. The two major numerical challenges––the strongly nonlinear, highly localized and parameter-dependent structural response of quasi-brittle materials, and the interaction between nonadjacent finite elements associated to nonlocality––are addressed in detail. Reliability of the numerical results is ensured by an h-adaptive strategy based on error estimation. We use a residual-type error estimator for nonlinear FE analysis based on local computations, which, at the same time, accounts for the nonlocality of the damage model. Efficiency is achieved by a proper combination of load-stepping control technique and iterative solver for the nonlinear equilibrium equations. A major issue is the computation of the consistent tangent matrix, which is nontrivial due to nonlocal interaction between Gauss points. With computational efficiency in mind, we also present a new nonlocal damage model based on the nonlocal average of displacements. For this new model, the consistent tangent matrix is considerably simpler to compute than for current models. The various ideas discussed in the paper are illustrated by means of three application examples: the uniaxial tension test, the three-point bending test and the single-edge notched beam test

A new damage model based on non-local displacements

A new non-local damage model is presented. Non-locality (of integral or gradient type) is incorporated into the model by means of non-local displacements. This contrasts with existing damage models, where a non-local strain or strain-related state variable is used. The new model is very attractive from a computational viewpoint, especially regarding the computation of the consistent tangent matrix needed to achieve quadratic convergence in Newton iterations. At the same time, its physical response is very similar to that of the standard models, including its regularization capabilities. All these aspects are discussed in detail and illustrated by means of numerical examples

Use of UHPH to Obtain Juices With Better Nutritional Quality and Healthier Wines With Low Levels of SO

Ultra-high pressure homogenization (UHPH) is a high pressure technique in which a fluid is pressurized by pumping at higher than 200 MPa and instantaneously depressurized at atmospheric pressure across a special valve. The full process takes <0.2 s and the in-valve time is <0.02 s. In the valve, extremely intense impacts and shear forces produce the nanofragmentation of biological tissue at a range of 100-300 nm. The antimicrobial effect is highly effective, reaching easily inactivation levels higher than 6-log cycles even at low in-valve temperatures. At in-valve temperatures of 140-150°C (0.02 s) the destruction of thermoresistant spores is possible. Even when the temperature in-valve can be elevated (70-150°C), it can be considered a gentle technology because of the tremendously short processing time. It is easy to get outlet temperatures after valve of 20-25°C by the expansion and assisted by heat exchangers. Thermal markers as hydroxymethylfurfural (HMF) are not formed, nor are deleterious effects observed in sensitive compounds as terpenes or anthocyanins, probably because of the low effect in covalent bonds of small molecules of the high-pressure techniques compared with thermal technologies. Additionally, intense inactivation of oxidative enzymes is observed, therefore protecting the sensory and nutritional quality of fruit juices and avoiding or reducing the use of antioxidants as sulphites. UHPH can be consider a powerful and highly effective continuous and sterilizing technology without thermal repercussions, able to keep fresh juices with most of their initial sensory and nutritional quality and allowing high-quality and natural fermented derivatives as wine

Influence of Yeasts in Wine Colour

Colour is the first impression that the consumer receives from wine and it influences the taste. Colour gives an idea about wine quality, age, oxidation and structure, so it has an important repercussion on the consumer perception of wine. Yeasts promote the formation of stable pigments by the production and release of fermentative metabolites affecting the formation of vitisin A and B type pyranoanthocyanins. The hydrox- and ycinnamate decarboxylase activity showed by some yeast strains produces highly reactive vinylphenols stimulating the formation of vinylphenolic pyranoanthocyanins from grape anthocyanin precursors during fermentation. Some yeasts also influence the formation of polymeric pigments by unclear mechanisms that can include the production of linking molecules such as acetaldehyde. Grape anthocyanins adsorbed in yeast cell walls during fermentation are removed from wine after racking processes affecting final pigment content. Moreover, the intensive use of non‐Saccharomyces yeasts in current oenology makes it interesting to assess the effect of new species in the improvement of wine colour

Conectado: concienciando contra el cyberbullying mediante un videojuego educativo

Conectado es un juego educativo diseñado y desarrollado para concienciar sobre el cyberbullying en las escuelas a jóvenes de secundaria. Este juego trabaja las emociones y coloca al jugador en el papel de víctima durante 40 minutos que dura el juego para que pueda empatizar con las víctimas y ponerse en la piel de estas. Se ha comprobado que el videojuego cumple su objetivo y es efectivo al incrementar la percepción que logran los alumnos sobre el ciberacoso como se ha demostrado a través de varios experimentos realizados con 257 jóvenes de 11 a 17 años de tres centros educativos distintos.Conectado es un juego educativo diseñado y desarrollado para concienciar sobre el cyberbullying en las escuelas a jóvenes de secundaria. Este juego trabaja las emociones y coloca al jugador en el papel de víctima durante 40 minutos que dura el juego para que pueda empatizar con las víctimas y ponerse en la piel de estas. Se ha comprobado que el videojuego cumple su objetivo y es efectivo al incrementar la percepción que logran los alumnos sobre el ciberacoso como se ha demostrado a través de varios experimentos realizados con 257 jóvenes de 11 a 17 años de tres centros educativos distintos

Use of Non-Saccharomyces Yeasts in Bottle Fermentation of Aged Beers

Bottle fermented and brewed beers are reaching more recognition in present days due to their high sensory complexity. These beers normally are produced by an initial tank fermentation to metabolize the sugars obtaining the typical alcoholic degree, and later the foam and CO2 pressure is produced by subsequent bottle fermentation. The sensory profile is improved by the formation of some fermentative volatiles, but also by the ageing on lees, because beers are brewed during several months with the yeast cells that performed the fermentation. The use of non-Saccharomyces yeast is a trending topic in many fermentative food industries (wines, beer, bread, etc.). They open new possibilities to modulate flavor and other sensory properties during fermentation and biological ageing. This chapter review the effect of some non-Saccharomyces yeasts such as Schizosaccharomyces pombe, Torulaspora delbrueckii, Lachancea thermotolerans, Saccharomycodes ludwigii, and Brettanomyces bruxellensis in the bottle fermentation and brewing of beers analyzing their metabolic specificities and sensory contribution on beer taste

Videojuegos como herramienta educativa en la escuela: concienciando sobre el ciberbullying

Históricamente el acoso se ha visto como una experiencia normal y aceptada parte del periodo de vida de los niños y adolescentes, experiencia con la que tenían que lidiar ellos mismos. No ha sido hasta hace dos décadas cuando se ha empezado a ver como un riesgo para la salud mental y física de estos. Se han documentado problemas asociados a la atención, el comportamiento y a la regulación emocional, así como importantes trastornos psicológicos e incluso suicidios en casos extremos. El acoso es un problema que afecta a todos los países y culturas en mayor o menor medida. Además, con la aparición de las nuevas tecnologías, junto a la temprana edad a la que los jóvenes empiezan a usar estas, ha hecho surgir otra forma de acoso denominado ciberacoso o ciberbullying, fenómeno que hace que los niños sean también vulnerables en sus casas. A pesar de la existencia de programas educativos y de concienciación en colegios e institutos, el acoso sigue estando presente en estos. Este proyecto trata sobre el desarrollo de una herramienta educativa para abordar este problema, mediante la concienciación sobre el acoso y el ciberacoso a través de un videojuego, una forma atractiva, eficiente y efectiva de introducir el tema a niños y jóvenes. Además el videojuego es complementario a soluciones más tradicionales como son folletos, presentaciones de profesionales, talleres, etc. Este videojuego pone al jugador en una situación de acoso y ciberacoso para que, de manera segura, aprenda cómo se ven afectadas las víctimas. Además, su eficacia ha sido probada mediante los experimentos realizados a 257 jóvenes de entre 12 y 17 años en tres centros educativos distintos, habiéndose identificado un cambio en la actitud de los jugadores hacia el acoso tras haberlo jugado

Sensorial repercussions of the formation of vinylphenolic pyranoanthocyanins

Using selected yeast, of the Saccharomyces cerevisiae specie, with hydroxycinnamate decarboxylase activity (HCDC+) we can transform anthocyanidin-3-O-glucosides from grapes into vinylphenolic pyranoanthocyanins. Saccaromyces cerevisiae don’t posses vinylphenol reductase activity (VPhR), however some yeast strains belonging to this specie are HCDC+. The selection of Saccharomyces cerevisiae strains HCDC+ with suitable fermentative and metabolic properties to red wine making allow us to stabilize the wine anthocyanins forming resistant pyranoanthocyanins. A relevant repercussion is that removing of hydroxycinnamic acids from musts we can avoid the formation of ethylphenols in red wine contaminated with the spoiling yeast Dekkera/Brettanomyces during barrel ageing. During in-vitro experiments we reduce notably the initial concentrations of 12 mg l-1 of p-coumaric acid, allowing can be below the detection limit in many vinifications

Wine Spoilage Yeasts: Control Strategy

Traditionally in winemaking, sulphur dioxide (SO2) is chemically the most widely used for microflora control as antimicrobial preservative. Other tested compounds for selective yeast control are sorbic and benzoic acids. Herein, we discuss the effectiveness and the application of traditional and novel treatments and biotechnologies for chemical and biological control of wine spoilage yeasts. The versatility of the killer toxins and the antimicrobial properties of natural compounds such as carvacrol, essential oils and bioactive peptides will be considered. Some of the wine spoilage yeasts that are intended to control belong to the genera Zygosaccharomyces, Saccharomycodes and Dekkera/Brettanomyces, but also the non-Saccharomyces yeasts species dominating the first phase of fermentation (Hanseniaspora uvarum, Hansenula anomala, Metschnikowia pulcherrima, Wickerhamomyces anomalus) and some others, such as Schizosaccharomyces pombe, depending on the kind of wine to be produced

Craft Beers: Current Situation and Future Trends

During the twentieth century, the consolidation of large multi-national beer companies and the homogenization of the specified beer types have led to a considerable growth in the beer industry. However, the growing demand by consumers of a single and distinctive product, with a higher quality and better sensory complexity, is allowing for a new resurgence of craft beer segment in recent years. This chapter reviews some different alternatives of innovation in the craft brewing process: from the bottle fermented beers with non-Saccharomyces yeast species, to the use of special malts or specific adjuncts, hop varieties, water quality, etc. All of them open a lot of new possibilities to modulate flavor and other sensory properties of beer, reaching also new consumers looking for a specific story in one of the oldest fermented beverages