Critical adsorption near edges

Symmetry breaking surface fields give rise to nontrivial and long-ranged order parameter profiles for critical systems such as fluids, alloys or magnets confined to wedges. We discuss the properties of the corresponding universal scaling functions of the order parameter profile and the two-point correlation function and determine the critical exponents eta_parallel and eta_perpendicular for the so-called normal transition.Comment: 22 pages, 5 figures, accepted for publication in PR

Correlation functions near Modulated and Rough Surfaces

In a system with long-ranged correlations, the behavior of correlation functions is sensitive to the presence of a boundary. We show that surface deformations strongly modify this behavior as compared to a flat surface. The modified near surface correlations can be measured by scattering probes. To determine these correlations, we develop a perturbative calculation in the deformations in height from a flat surface. Detailed results are given for a regularly patterned surface, as well as for a self-affinely rough surface with roughness exponent $\zeta$. By combining this perturbative calculation in height deformations with the field-theoretic renormalization group approach, we also estimate the values of critical exponents governing the behavior of the decay of correlation functions near a self-affinely rough surface. We find that for the interacting theory, a large enough $\zeta$ can lead to novel surface critical behavior. We also provide scaling relations between roughness induced critical exponents for thermodynamic surface quantities.Comment: 31 pages, 2 figure

Wetting films on chemically heterogeneous substrates

Based on a microscopic density functional theory we investigate the morphology of thin liquidlike wetting films adsorbed on substrates endowed with well-defined chemical heterogeneities. As paradigmatic cases we focus on a single chemical step and on a single stripe. In view of applications in microfluidics the accuracy of guiding liquids by chemical microchannels is discussed. Finally we give a general prescription of how to investigate theoretically the wetting properties of substrates with arbitrary chemical structures.Comment: 56 pages, RevTeX, 20 Figure

‘‘The Soldiers Came to the House’’: Young Children’s Responses to The Colour of Home

This article begins by reflecting on the present refugee crisis and its relevance to children in the UK. It identifies the need for teaching about the refugee experience to young children and argues that literature can provide a conduit for this. Sincethemillenniumtherehasbeenarapidincreaseinthenumberofbookspublished forchildren whichtake thisastheir theme, aimed atever-youngerreaders.Takingasa case study The Colour of Home by Mary Hoffman, a picturebook commonly used in lower primary classrooms, the article considers how this text promotes understanding and validates the circumstances of refugees. It closely examines the motivations and aims of the writer, how the book was mediated by teachers in the primary classroom, and how refugee and non-refugee children read and responded to it. Findings are presented from an interview with Mary Hoffman herself, juxtaposed with data from threeclassroomssuggestingthatpupilsgainedvaluableinsightintoacomplicatedand controversial issue. However the research concludes that viewing children through a refugee/non-refugee binary was reductive in not recognising the multi-layered nuances of meaning which were constructed by young readers who brought to bear a wide variety of individual life and family experiences. Furthermore, teachers in the study played a powerful role in mediating the texts when sharing them in the classroom, and devised a selection of stimulating resources to provoke reader response in terms of empathy, ‘‘social action’’, and some critical literacy