Binary separation in very thin nematic films: thickness and phase coexistence

The behavior as a function of temperature of very thin films (10 to 200 nm) of pentylcyanobiphenyl (5CB) on silicon substrates is reported. In the vicinity of the nematic/isotropic transition we observe a coexistence of two regions of different thicknesses: thick regions are in the nematic state while thin ones are in the isotropic state. Moreover, the transition temperature is shifted downward following a 1/h^2 law (h is the film thickness). Microscope observations and small angle X-ray scattering allowed us to draw a phase diagram which is explained in terms of a binary first order phase transition where thickness plays the role of an order parameter.Comment: 5 pages, 3 figures, submitted to PRL on the 26th of Apri

Beyond crime statistics: the construction and application of a criminogenity monitor in Amsterdam

Criminologists have devoted a great deal of attention to risk factors - also called criminogenic factors - leading to criminal offending. This paper presents a criminogenity monitor which includes 19 risk factors that underlie crime. These factors do not themselves cause criminal behaviour; rather, they must be seen as signals that crimes may be committed. After discussing how the criminogenity monitor was constructed, we apply the risk factors we examined to the situation in Amsterdam, capital city of the Netherlands. The monitor is intended to function particularly as an instrument to rationalise policy-makers' work in targeting and preventing symptoms of crime at three geographical levels: the entire city, its boroughs and its neighbourhoods. © 2012 The Author(s)

Ethnic profiling in the Netherlands? A reflection on expanding preventive powers, ethnic profiling and a changing social and political context

Criminal Justice: Legitimacy, accountability, and effectivit

Order-Parameter Dynamics near the Lifshitz Point in a Ferroelectric Liquid-Crystal

Contains fulltext : 27865.pdf (publisher's version ) (Open Access

Thickness-dependent phase transition in thin nematic films

Contains fulltext : 28882.pdf (publisher's version ) (Open Access

Confinement effects on the collective excitations in thin nematic films

Contains fulltext : 92668.pdf (publisher's version ) (Open Access

Gapless Phason in an Antiferroelectric Liquid Crystal

The phason dispersion in the antiferroelectric Sm-CA* liquid crystalline phase of 4-(1-methylheptyloxycarbonyl)phenyl 4’-octyloxybiphenyl-4-carboxylate has been studied by quasielastic light-scattering experiments. The phason is found to be gapless as predicted for a Goldstone mode recovering the broken continuous symmetry. The dispersion has a minimum at q=2qc, where qc is the wave vector of the unperturbed Sm-CA* structure. These results are consistent with the alternating-tilt model of the antiferroelectric Sm-CA* phase