Estimació quantitativa de la irreversibilitat dels processos tècnics segons la termodinàmica dels medis continus

En el mart de la Termodinàmica Racional dels Medis Continus ha estat fet un càlcul general de l'eficiència d'un procés (no necessàriament cíclic) termodinàmic. Com una consegüència s'ha obtingut la formulació de la segona llei de la termodinàmica sota el punt de vista de la teoria de camps. Fem aplicació a un determinat tipus de materials, i trobem les restriccions que imposa la segona llei a les equacions constitutives que defineixen aquest tipus de material. Es comenta la importància del concepte de fredor en la teoria de la transmissió de la calor i les possibilitats de reduir les irreversibilitats inherents als processos. Es pot concloure que la formulació general que presentem permet d'analitzar i justificar més racionalment les irreversibilitats en qualsevol procés

Problematizing cultural appropriation

Cultural appropriation in games entails the taking of knowledge, artifacts or expression from a culture and recontextualizing it within game structures. While cultural appropriation is a pervasive practice in games, little attention has been given to the ethical issues that emerge from such practices with regards to how culture is portrayed. This paper problematizes cultural appropriation in the context of a serious game for children inspired by Día de los Muertos, a Mexican festival focused on remembrance of the dead. Taking a research through design approach, we demonstrate that recontextualised cultural elements can retain their basic, original meaning. However, we also find that cultural appropriation is inevitable and its ethical implications can be far reaching. In our context, ethical concerns arose as a result of children’s beliefs that death affects prominent others and their destructive ways of coping with death. We argue that revealing emergent ethical concerns is imperative before deciding how and in what way to encourage culturally authentic narratives

El 1er de Maig a Catalunya (1890-1918) : afirmació, lluita i festa /

Tal i com apunta el títol, la tesi El 1er de Maig a Catalunya (1890-1918). Afirmació, lluita i festa és un treball de recerca sobre l'evolució del 1er de Maig des de la primera celebració, l'any 1890, fins a finals de la Primera Guerra Mundial, l'any 1918. Uns anys que van servir per afirmar la jornada com el dia del treballador així com definir la forma de la celebració, un dia de lluita o un dia de festa. Una forma que es definirà a partir de les postures vers la jornada que mantindran les tres corrents ideològiques que van influir en el moviment obrer català durant el període que va del 1890 al 1918: el socialisme- marxista, l'anarquisme i el republicanisme. Cadascuna d'elles enfocava la jornada des de diferents perspectives a partir tant de l'origen atribuït com de l'objectiu a assolir amb el 1er de Maig. El resultat es una celebració caracteritzada per la lluita, cas anarquista, o una visió reivindicativa alhora que festiva, cas dels socialistes i a la qual donarien suport els republicans. En aquest sentit també les realitats locals van establir uns 1er de Maig diferents a partir de la força que tenia el moviment obrer local i les relacions amb els altres sectors socials de les poblacions. Així tenim Barcelona com el centre de poder econòmic i on es trobava el moviment obrer associat més fort; poblacions amb un important teixit industrial com Sabadell, Mataró o Manresa i per tant amb un important moviment obrer, a prop de la postura anarquista la primera i marxista i republicanes les dues darreres; viles importants durant la primera industrialització, però en una situació de crisi des dels vuitanta, cas de les poblacions del Baix Empordà com Sant Feliu o Palafrugell, de la Muntanya com Vic o Olot, o de l'interior com Igualada, situació que dona lloc a un moviment associatiu feble; i poblacions poc desenvolupades industrialment com Ripoll, Figueres o Tortosa. El resultat és un 1er de Maig amb programes diferents però amb un mateix protagonista, l'obrer. Per aquesta raó la jornada del 1er de Maig es va convertir en un símbol del moviment obrer, un referent del futur, un dia en el qual els obrers disposaven del seu temps i de l'espai central de les seves viles, del qual eren exclosos la resta de l'any. Al voltant d'aquest símbol es forma una simbologia pròpia de la jornada, nous símbols es fonen amb ja existents propis o compartits: la bandera, els lemes, les cançons, els actes que creen un ambient propi, tot això conforme un codi simbòlic que dona una significació pròpia al 1er de Maig, un dia en el que el protagonista és un sector de la societat el qual era al marge del sistema políticThe thesis entitled El 1er de Maig a Catalunya (1890-1918). Afirmació, lluita i festa is a research about the May Day from the first celebration, in 1890, to the end of the First World War, in 1918. This period was the time which May Day became the day of the working class and the kind of celebration was defined, a struggle day or a holiday day. The way to celebrate this day was defined by who played the main role this day, the working class. Working Class in Catalonia were influenced by three main ideologies: Socialist Marxists, Anarchism and Republicanism. Every one of them represented tree different ways to celebrated May Day, which are based by the vision of the day, one struggle day, Anarchism stance, or a demand day and holiday, Socialism and Republicanism stance. Also the local realities affected the May Day celebration because of the different situations which working local class had to affronter. Barcelona as centre of industrial and power decision is the reference from the working class movement; Sabadell, Manresa or Mataró have a significant industry, based on cotton the first and the textile the two last, with a valuable labour movement working for their permanence and near of Anarchism the first town and the Socialism and Republicanism the lasts; others towns were relevant during the first industrialisation but in the 1880s came into a very important crisis, which was a cause for the weakening of their local working class, in this situation was Sant Feliu or Palafrugell, situated in Baix Empordà, from the region named Muntanya towns like Vic o Olot or Igualada, from the inner of Catalonia; and towns as Ripoll, Figueres or Tortosa were hardly industrialized. The type of industry, new industry or crisis industry, the geographical situation, near or far away from Barcelona, and the relationship between the different sectors of local society determined the situation of the local working class and as result on the Mai Day, because the worker was who played a leading role this day. This is the reason that makes Mai Day a symbol of the working movement. The day became a referent of the past and of the future. During this day the workers have the time and the space of their towns at their disposal. They take up the central town, a space from which they are excluded the rest of the year. At the same time, around the day set up a system of symbols news or shared: banner, slogans, songs, acts, programs... All of them give a meaning to the Mai day

Gender norms in war: Masculine and Feminine identities in Elizabeth Gaskell's Sylvia's Lovers

The Napoleonic wars had a devastating effect on Britain on a political and social level. In Sylvia's Lovers, Elizabeth Gaskell portrays how the private sphere was affected by the public political decisions and how common people were concerned with the new situation which directly impacted their lives. Political decisions affect the population's private lives, both women and men, but in different ways. By taking a closer look at the power dynamics between genders, the public and domestic spheres, this dissertation explores the different levels of patriarchal oppression women and men suffered publicly and at a domestic level.Les guerres Napoleòniques van tenir un efecte devastant en el Regne Unit a un nivell polític i social. A Els amors de Sylvia, Elizabeth Gaskell representa com la esfera privada era afectada per les decisions polítiques públiques i com la gent estava preocupada amb la nova situació que impactava les seves vides directament. Les decisions polítiques afecten les vides privades de la població, tant per dones com per homes, però de formes diferents. En analitzar detingudament les dinàmiques de poder entre els gèneres, les esferes domèstiques i públiques, aquest treball explora els diferents nivells de opressió patriarcal que les dones i els homes sofrien públicament i a nivell domèstic.Las guerras Napoleónicas tuvieron un efecto devastante en el Reino Unido a un nivel político y social. En Los amores de Sylvia, Elizabeth Gaskell representa como la esfera privada era afectada por las decisiones políticas públicas y cómo la gente estaba preocupada con la nueva situación que impactaba sus vidas directamente. Las decisiones políticas afectan las vidas privadas de la población, tanto para mujeres como para hombres, pero de formas diferentes. En analizar con detenimiento las dinámicas de poder entre los géneros, las esferas domésticas y públicas, este trabajo explora los diferentes niveles de opresión patriarcal que las mujeres y los hombres sufrían públicamente y a nivel doméstico

Multiresolution mapping and informative path planning for UAV-based terrain monitoring

© 2017 IEEE. Unmanned aerial vehicles (UAVs) can offer timely and cost-effective delivery of high-quality sensing data. However, deciding when and where to take measurements in complex environments remains an open challenge. To address this issue, we introduce a new multiresolution mapping approach for informative path planning in terrain monitoring using UAVs. Our strategy exploits the spatial correlation encoded in a Gaussian Process model as a prior for Bayesian data fusion with probabilistic sensors. This allows us to incorporate altitude-dependent sensor models for aerial imaging and perform constant-time measurement updates. The resulting maps are used to plan information-rich trajectories in continuous 3-D space through a combination of grid search and evolutionary optimization. We evaluate our framework on the application of agricultural biomass monitoring. Extensive simulations show that our planner performs better than existing methods, with mean error reductions of up to 45% compared to traditional 'lawnmower' coverage. We demonstrate proof of concept using a multirotor to map color in different environments

Fermi Edge Singularities and Backscattering in a Weakly Interacting 1D Electron Gas

The photon-absorption edge in a weakly interacting one-dimensional electron gas is studied, treating backscattering of conduction electrons from the core hole exactly. Close to threshold, there is a power-law singularity in the absorption, $I(\epsilon) \propto \epsilon^{-\alpha}$, with $\alpha = 3/8 + \delta_+/\pi - \delta_+^2/2\pi^2$ where $\delta_+$ is the forward scattering phase shift of the core hole. In contrast to previous theories, $\alpha$ is finite (and universal) in the limit of weak core hole potential. In the case of weak backscattering $U(2k_F)$, the exponent in the power-law dependence of absorption on energy crosses over to a value $\alpha = \delta_+/\pi - \delta_+^2/2\pi^2$ above an energy scale $\epsilon^* \sim [U(2k_F)]^{1/\gamma}$, where $\gamma$ is a dimensionless measure of the electron-electron interactions.Comment: 8 pages + 1 postscript figure, preprint TPI-MINN-93/40-

Breakdown of anomalous channeling with ion energy for accurate strain determination in gan-based heterostructures

The influence of the beam energy on the determination of strain state with ion channeling in GaN-based heterostructures (HSs) is addressed. Experimental results show that anomalous channeling may hinder an accurate analysis due to the steering effects at the HS interface, which are more intense at lower ion energies. The experimental angular scans have been well reproduced by Monte Carlo simulations, correlating the steering effects with the close encounter probability at the interface. Consequently, limitations in the determination of the strain state by ion channeling can be overcome by selecting the adequate beam energy