QCD under extreme conditions: an informal discussion

We present an informal discussion of some aspects of strong interactions under extreme conditions of temperature and density at an elementary level. This summarizes lectures delivered at the 2013 CERN -- Latin-American School of High-Energy Physics and is aimed at students working in experimental high-energy physics.Comment: 11 pages, 6 figures, based on lectures at the 2013 CERN -- Latin-American School of High-Energy Physics, Arequipa, Peru, submitted for publication in a CERN Yellow Repor

The role of quark mass in cold and dense pQCD and quark stars

For almost twenty years the effects of a nonzero strange quark mass on the equation of state of cold and dense QCD were considered to be negligible, thereby yielding only minor corrections to the mass-radius diagram of compact stars. By computing the thermodynamic potential to first order in \alpha_s, and including the effects of the renormalization group running of the coupling and strange quark mass, we show that corrections can be of the order of 25%, and dramatically affect the structure of compact stars.Comment: 4 pages, 2 figures, contribution to QM2005 proceeding

Finite-Size Effects on Nucleation in a First-Order Phase Transition

We discuss finite-size effects on homogeneous nucleation in first-order phase transitions. We study their implications for cosmological phase transitions and to the hadronization of a quark-gluon plasma generated in high-energy heavy ion collisions. Very general arguments allow us to show that the finite size of the early universe has virtually no relevance in the process of nucleation and in the growth of cosmological bubbles during the primordial quark-hadron and the electroweak phase transitions. In the case of high-energy heavy ion collisions, finite-size effects play an important role in the late-stage growth of hadronic bubbles.Comment: 6 pages, no figures, 1 reference adde

A multi-objective genetic algorithm for the design of pressure swing adsorption

Pressure Swing Adsorption (PSA) is a cyclic separation process, more advantageous over other separation options for middle scale processes. Automated tools for the design of PSA processes would be beneficial for the development of the technology, but their development is a difficult task due to the complexity of the simulation of PSA cycles and the computational effort needed to detect the performance at cyclic steady state. We present a preliminary investigation of the performance of a custom multi-objective genetic algorithm (MOGA) for the optimisation of a fast cycle PSA operation, the separation of air for N2 production. The simulation requires a detailed diffusion model, which involves coupled nonlinear partial differential and algebraic equations (PDAEs). The efficiency of MOGA to handle this complex problem has been assessed by comparison with direct search methods. An analysis of the effect of MOGA parameters on the performance is also presented