Effect of dispersion correction on the Au(1 1 1)-H2O interface: A first-principles study

A theoretical study of the H2O-Au(1 1 1) interface based on first principles density functional theory (DFT) calculations with and without inclusion of dispersion correction is reported. Three different computational approaches are considered. First, the standard generalized gradient approximation (GGA) functional PBE is employed. Second, an additional energy term is further included that adds a semi-empirically derived dispersion correction (PBE-D2), and, finally, a recently proposed functional that includes van der Waals (vdW) interactions directly in its functional form (optB86b-vdW) was used to represent the state-of-the art of DFT functionals. The monomeric water adsorption was first considered in order to explore the dependency of geometry on the details of the model slab used to represent it (size, thickness, coverage). When the dispersion corrections are included the Au-H2O interaction is stronger, as manifested by the smaller dAu-O and stronger adsorption energies. Additionally, the interfacial region between Au(1 1 1) slab surfaces and a liquid water layer was investigated with Born-Oppenheimer molecular dynamics (BOMD) using the same functionals. Two or three interfacial orientations can be determined, depending on the theoretical methodology applied. Closest to the surface, H2O is adsorbed O-down, whereas further away it is oriented with one OH bond pointing to the surface and the molecular plane parallel to the normal direction. For the optB86b-vdW functional a third orientation is found where one H atom points into the bulk water layer and the second OH bond is oriented parallel to the metal surface. As for the water density in the first adsorption layer we find a very small increase of roughly 8%. From the analysis of vibrational spectra a weakening of the H-bond network is observed upon the inclusion of the Au(1 1 1) slab, however, no disruption of H-bonds is observed. While the PBE and PBE-D2 spectra are very similar, the optB86b-vdW spectrum shows that the H-bonds are even more weakened.Ministerio de Ciencia e Innovación de España-MAT2012-31526 y CSD2008-002

Have No Fear! White Ladies are Here!: Interrogating the Image and Institutionalization of White Womanhood in the Classroom

Using an interdisciplinary approach, this project examines how the American conception of white womanhood has informed and molded perceptions of what makes a “good” teacher. By examining historical and contemporary film-based discourses around white womanhood, it is clear that teaching has been transformed into another form of mothering, tying the teaching field to the white woman. This discursive connection is made seemingly permanent through the institutionalization of the white woman in the classroom. This paper will then begin to explore how this process has affected the larger educational system. Ultimately, this project hopes to encourage white women in education to reflect and understand how their choices fit into a larger discourse

Review of 13th: A Beautiful and Powerful Wake Up Call

This film review of 13th is featured in the journal Tapestries: Interwoven voices of local and global identities, volume 6