Testing the Zurek-Kibble Causality Bounds with Annular Josephson Tunnel Junctions

Zurek has provided simple causal bounds for the onset of phase transitions in condensed matter, that mirror those proposed by Kibble for relativistic quantum field theory. In this paper we show how earlier experiments with annular Josephson tunnel junctions are consistent with this scenario, and suggest how further experiments might confirm it.     

An MILP formulation for the synthesis of protein purification processes

This paper presents a mixed integer linear programming (MILP) model for the optimal synthesis of chromatographic protein purification processes including the time line in which our target protein product is collected. The model is linearised using piecewise linear approximation strategies and tested on three example protein mixtures, containing up to 13 contaminants and selecting from a set of up to 21 candidate steps. The results are also compared with previous literature models attempting to solve the same problem and show that the proposed approach offers significant gains in computational efficiency without compromising the quality of the solution.     

Developing a one-dimensional heat and mass transfer algorithm for describing the effect of green roofs on the built environment: Comparison with experimental results

This paper investigates the mathematical modelling of the effect of green roofs on mitigating raised urban temperatures. A dynamic, one-dimensional model is developed, describing heat and mass transfer in building materials, considered as capillary-porous bodies, the vegetated canopy, modelled as a combined plant–air canopy layer, the soil and the air. The model is validated with an experiment, conducted in the Welsh School of Architecture, in Cardiff, in summer 2004. The right choice of parameters that affect the accuracy of the model (such as the expression of the convective heat transfer coefficient and stomatal resistance) is discussed. Special attention is given to the comparison between the experimental results and the outputs of only heat transfer algorithms and heat and mass transfer expressions. Taking these comparisons into consideration, conclusions are drawn about developing an accurate algorithm describing the thermal effect of green roofs on the built microclimate.     

Monte Carlo calculations applied to the parametrical studies in a whole body counter

The use of a Monte Carlo code for the analysis and interpretation of whole body counting measurements is described. The sources of error are analysed and commented to show how a counting geometry can be improved by improving accuracy and precision in a measurement. The effects of body size, contamination distribution and counting geometry are also parameters which can be easily used to improve the quality of a body burden assessment. The optimisation of the detector (position, shielding, shape and size) is also commented on the basis of calculations in the photon energy range usually encountered in routine measurements. The results obtained from these simulations are confirmed by experimental results.