Prisons as total institution semiospheres

The main objective of this article is to combine Juri Lotman’s theory of the semiosphere – including its concepts of boundary, core, and periphery – with Erving Goffman’s theory of the total institution. The purpose is to develop a framework conducive to examining the prison as an object of study, equally emphasizing both its internal as well as external relations. This work positions itself within the contexts of the relative decline of the field of prison ethnography, few or no studies done applying semiotic metalanguage to the prison or the total institution, and none applying the theory of the semiosphere to either. This work is oriented according to an analytical or neutral mode; its point is not to offer a normative programme, but to offer a new description of the research object and a new language of description in which to speak of this object. The secondary objectives of this article include demonstrating that Lotman’s theory of the semiosphere and Goffman’s theory of the total institution are compatible, that Lotman’s theory actually refines Goffman’s original, that Lotman’s theory taken independently and Goffman’s theory as refined by Lotman’s are both compatible with the direction of contemporary prison ethnography, and that the framework presented in this work has the potential to reinvigorate the field of prison ethnography.

Electrochemical drag effect on grain boundary motion in ionic ceramics

The effects of drag imposed by extrinsic ionic species and point defects on the grain boundary motion of ionic polycrystalline ceramics were quantified for the generality of electrical, chemical, or structural driving forces. In the absence of, or for small driving forces, the extended electrochemical grain boundary remains pinned and symmetrically distributed about the structural interface. As the grain boundary begins to move, charged defects accumulate unsymmetrically about the structural grain boundary core. Above the critical driving force for motion, grain boundaries progressively shed individual ionic species, from heavier to lighter, until they display no interfacial electrostatic charge and zero Schottky potential. Ionic p–n junction moving grain boundaries that induce a finite electrostatic potential difference across entire grains are identified for high velocity grains. The developed theory is demonstrated for Fe-doped SrTiO3. The increase in average Fe concentration and grain boundary crystallographic misorientation enhances grain boundary core segregation and results in thick space charge layers, which leads to a stronger drag force that reduces the velocity of the interface. The developed theory sets the stage to assess the effects of externally applied fields such as temperature, electromagnetic fields, and chemical stimuli to control the grain growth for developing textured, oriented microstructures desirable for a wide range of applications.

Influence of Ce3+ polarons on grain boundary space-charge in proton conducting Y-doped BaCeO3

Ce3+ polarons associated with oxygen vacancies in the grain boundary core lowers the space-charge potential and may enhance n-type conduction.

Origin of fast oxide ion diffusion along grain boundaries in Sr-doped LaMnO3

Enhanced oxide ion diffusion by 3 to 5 orders of magnitude along grain boundary core in Sr-doped LaMnO3.

Open Questions in Nanosegregation

Despite nanosegregation of solutes at grain boundaries has been intensively studied in the past decades and numerous theoretical data as well as experimental values on characteristic energies and/or enthalpies and entropies exist some questions remain still unanswered. In this paper some of these questions – Which energetic quantities obtained in different ways, experimentally and theoretically, can be mutually compared? What is the segregation site of a solute in the grain boundary core? – are discussed in more detail. It will be shown that the entropy of grain boundary segregation plays an important and indisputable role in responding some issues and that understanding of its role will help us to elucidate fundamentals of the grain boundary segregation.

Direct observation of Σ7 domain boundary core structure in magnetic skyrmion lattice

Skyrmions are topologically protected nanoscale magnetic spin entities in helical magnets. They behave like particles and tend to form hexagonal close-packed lattices, like atoms, as their stable structure. Domain boundaries in skyrmion lattices are considered to be important as they affect the dynamic properties of magnetic skyrmions. However, little is known about the fine structure of such skyrmion domain boundaries. We use differential phase contrast scanning transmission electron microscopy to directly visualize skyrmion domain boundaries in FeGe1−xSix induced by the influence of an “edge” of a crystal grain. Similar to hexagonal close-packed atomic lattices, we find the formation of skyrmion “Σ7” domain boundary, whose orientation relationship is predicted by the coincidence site lattice theory to be geometrically stable. On the contrary, the skyrmion domain boundary core structure shows a very different structure relaxation mode. Individual skyrmions can flexibly change their size and shape to accommodate local coordination changes and free volumes formed at the domain boundary cores. Although atomic rearrangement is a common structural relaxation mode in crystalline grain boundaries, skyrmions show very unique and thus different responses to such local lattice disorders.

Proton Conduction in Solids: Bulk and Interfaces

Truly proton-conducting materials would have an immense impact on sustainable energy technologies for the 21st century, through efficient fuel cells, electrolyzers, and gas-separation membranes. However, proton conduction combined with materials stability seems difficult to achieve, and some hurdles and pathways are outlined in this article. Problems, possibilities, and artifacts of transport across and along interfaces are discussed, linked mainly to space-charge layer properties and engineering of the grain-boundary core and to water in nanovoids. The importance of protons in many semiconducting functional oxides is also explained. At lower temperatures and in humid environments, the presence of protonated cation vacancies (Ruetschi defects) is predicted and is expected to play an important role in photoelectrochemistry, catalysis, and surface transport.

Atomic-Scale Processes of Grain-Boundary Faceting in a Zirconia Bicrystal

In this paper, we characterized atomic structure of a Σ = 3, [110]/{112} grain boundary in a yttria-stabilized cubic zirconia bicrystal. High-resolution transmission electron microscopy (HRTEM) clearly revealed that the grain boundary migrated to form {111}/{115} periodical facets, although the bicrystal was initially joined so as to have the symmetric straight boundary plane of {112}. Atomic-scale process for the facet growth could be modeled by the continuous flippings of atoms at the boundary core.