NASA TN D-6980 APPLICATION OF THERMODYNAMICS TO SILICATE CRYSTALLINE SOLUTIONS
i FOREWORD iii ACKNOWLEDGMENTS v SYMBOLS ix 1 THERMODYNAMIC RELATIONS IN CRYSTALLINE SOLUTIONS 1 2 THERMODYNAMIC STABILITY OF A SOLUTION 11 3 COMPOSITION OF COEXISTING PHASES 15 4 MEASUREMENT OF COMPONENT ACTIVITIES BY ANALYSIS OF PHASE DIAGRAMS 25 5 MEASUREMENT OF COMPONENT ACTIVITY USING COMPOSITION OF COEXISTING MINERALS 35 6 ORDER-DISORDER IN Fe-Mg SILICATES 39
Cation distributions in multisublattice ionic crystals and applications to solid solutions of ferrimagnetic garnets and spinels
Abstract An equilibrium expression of cation transfer among oxygen-coordination lattice sites is given which takes into account the solid solution concentration parameters and the stoichiometric restrictions in multisublattice crystals. Some energy considerations are made about cation site preferences in ionic crystals. Ionic distributions in sublattices are inferred. Comparison of derived distribution expressions for some magnetic garnet and spinel solid solutions is made with experimental magnetic moments from literature.
Struggles for Visibility
This article addresses the ways in which terrorists are rendered visible in the news media. By studying images used in coverage of terrorists, the article focuses on the visual construction of this figure, which symbolizes the public’s notion of the “enemy”, in terms of specific attacks and the general threat thereof as well as terrorist actors, networks, and ideologies. The article takes its point of departure in the assumption that two visual forms are prevalent for representing terrorists in the news media, “surveillance representations” and “self-representations”. Based on this assumption, the article is guided by a principal research question, namely: How are terrorists made visible in the news media through surveillance representations and self-representations and what are the prevalent genres for visually representing terrorist actors? The article draws on a theoretical framework concerning the news media’s propensity to personalize the terrorist and the mediated visibility of terrorists. Empirically, the article is based on a quantitative content analysis of coverage of terrorism by Danish public service broadcasters DR and TV2 in 2016 to provide an overview of the proportions between surveillance representations and self-representations and develop a typology of the most widespread genres: ID photography, surveillance footage, selfies and similar, and private snapshots.