Critical velocity in kink solutions of the sine-Gordon equation

The goal of this work is to present a way to deduce the value of the critical velocity observed in soliton-like solutions of a perturbed version of the sine-Gordon equation. To do so, an ODE system is obtained from the perturbed sine-Gordon equation using a variational approach; the resulting Hamiltonian system is then studied. From that, a Melnikov integral formula for the critical velocity is deduced via an energy balance reasoning. Finally, the problem is approached from a geometrical point of view that allows for an interpretation of the previous results in terms of intersections of invariant manifolds of periodic orbits

Safety-informed design of lead-cooled reactors on mobile platforms

Nuclear power has a prominent role to play in the energy landscape of the 21st century. To- gether with large reactor designs that make the most out of economies of scale, small, modular reactors (SMR) may also play a role thanks to their potential modular, factory-based and fast deployment, which have the potential to minimize the capital cost of nuclear, which is one of its main drawbacks. Among such designs, lead-cooled fast reactors (LFR) present some unique strengths, among others their lack of pressurization of the primary system and their potential to passively remove decay heat by means of natural convection. The SUNRISE project, in Sweden, is an effort by, among others, KTH to prove the feasability of this technology. In that context, the analytical design tool ADELE, which draws from the BELLA code produced at KTH, is developed. Its goal is to provide a fast-to-iterate algorithm that uses basic physics constraints to obtain the core design without relying on more computationally costly methods, like Monte Carlo simulations, which are regularly used for that purpose. Specifically, a system that is capable of removing all the residual heat via convective cooling is obtained from a short list of basic input values. This algorithm is implemented into a mobile application, with the goal of being available to Nuclear Engineering students. The resulting code is capable of replicating reference core designs with a reasonable degree of accuracy, given the simplicity of the assumptions used in the process

Jardins per a la salut

Facultat de Farmàcia, Universitat de Barcelona. Ensenyament: Grau de Farmàcia. Assignatura: Botànica farmacèutica. Curs: 2014-2015. Coordinadors: Joan Simon, Cèsar Blanché i Maria Bosch.Els materials que aquí es presenten són el recull de les fitxes botàniques de 128 espècies presents en el Jardí Ferran Soldevila de l’Edifici Històric de la UB. Els treballs han estat realitzats manera individual per part dels estudiants dels grups M-3 i T-1 de l’assignatura Botànica Farmacèutica durant els mesos de febrer a maig del curs 2014-15 com a resultat final del Projecte d’Innovació Docent «Jardins per a la salut: aprenentatge servei a Botànica farmacèutica» (codi 2014PID-UB/054). Tots els treballs s’han dut a terme a través de la plataforma de GoogleDocs i han estat tutoritzats pels professors de l’assignatura. L’objectiu principal de l’activitat ha estat fomentar l’aprenentatge autònom i col·laboratiu en Botànica farmacèutica. També s’ha pretès motivar els estudiants a través del retorn de part del seu esforç a la societat a través d’una experiència d’Aprenentatge-Servei, deixant disponible finalment el treball dels estudiants per a poder ser consultable a través d’una Web pública amb la possibilitat de poder-ho fer in-situ en el propi jardí mitjançant codis QR amb un smartphone

Critical velocity in kink solutions of the sine-Gordon equation

The goal of this work is to present a way to deduce the value of the critical velocity observed in soliton-like solutions of a perturbed version of the sine-Gordon equation. To do so, an ODE system is obtained from the perturbed sine-Gordon equation using a variational approach; the resulting Hamiltonian system is then studied. From that, a Melnikov integral formula for the critical velocity is deduced via an energy balance reasoning. Finally, the problem is approached from a geometrical point of view that allows for an interpretation of the previous results in terms of intersections of invariant manifolds of periodic orbits