Gauge transformations of Spin-Orbit interactions in graphene

Inclusion of spin-dependent interactions in graphene in the vicinity of the Dirac points can be posed in terms of non-Abelian gauge potentials. Such gauge potentials being surrogates of physical electric fields and material parameters, only enjoy a limited gauge freedom. A general gauge transformation thus in general changes the physical model. We argue that this property can be useful in connecting reference physical situations, such as free particle or Rashba interactions to non-trivial physical Hamiltonians with a new set of spin-orbit interactions, albeit constrained to being isoenergetic. We analyse different combinations of spin-orbit interactions in the case of monolayer graphene and show how they are related by means of selected non-Abelian gauge transformations

Derechos de propiedad informales y gestión comunal de las pesquerías en el País Vasco. Un enfoque ecológico-institucional

Editada en la Fundación SEPIEste trabajo tiene como objetivo estudiar el papel desempeñado por las cofradías de mareantes en el desarrollo y la gestión de la pesca en el País Vasco hasta principios del siglo XX. Gracias a un marco institucional particular, los gremios vascos construyeron un modelo de gestión específico que permitió la explotación exclusiva de los recursos pesqueros en la costa vasca. Una parte importante del carácter de este régimen de explotación se deriva de las particularidades de los recursos pesqueros y de los mercados de la pesca, pero también está relacionado con un modelo histórico de organización y de relación de la sociedad con la naturaleza. Finalmente, se presentan las consecuencias sociales y económicas de la transformación de la base legal que indirectamente sustentaba el aprovechamiento exclusivo en el último cuarto del siglo XIX.This paper deals with the role played by the Maritime Guilds in the development and management of the fisheries conducted firom the Basque shore until the first half of the 20th century. It contends that thanks to a particular institutional framework Guilds were able to build up a management model based on the exclusive use of the fishing resources. The character of this regime of use stems from the behaviour of the fishing resources and from the characteristics of the fish markets in Spain before the 20th century, but it is also related to an historical model of organisation and relationship between society and nature. Finally, the social and economic consequences of the process of institutional change that eliminated the legal basis of the exclusiveness are analysed.Publicad

Una aproximación al sector pesquero tradicional vasco (c.1800-c.1880)

This paper deals with the Basque traditional fisheries during the 19th century. It contends that its performance depended to a great extent on the conditions of the natural environment. Nevertheless, social conditionings arose among the natural restrictions. Most of the research on fishing history has been focused on a supply-side analysis. However, apart from some few exceptions, none of the existing research has shown special interest in the role played by demand in the evolution of the fishing sector. What this paper seeks to explain is that although the productive structure of the Basque traditional fishing communities was directly shaped by the ecological behaviour of the exploited resources, market and demand conditions were crucial to understand how it devolved

Bond-slip in reinforced concrete elements

A model for fiber reinforced composites that takes into account the fiber slipping is presented in this paper and applied to the analysis of reinforced concrete elements. The model is formulated within the framework of the plasticity theory and the mixtures theory, considering two phases corresponding to the matrix (concrete) and the fibers (reinforcing bars) and modifying the behavior of the last to take into account the relative displacement between the two phases. An elasto-plastic interface model developed by other writers is used to describe the bond-slip mechanism. The resulting model is attractive for the analysis of reinforced concrete problems at the macro-structural level since the explicit discretization of reinforcing bars and interface is not required, with the consequent computational cost reduction. The paper concludes with application examples and comparisons with experimental results of reinforced concrete elements that show the capacity of the model developed. © ASCE.Fil: Luccioni, Bibiana Maria. Universidad Nacional de Tucuman. Facultad de Cs.exactas y Tecnología. Laboratorio de Estructuras; ArgentinaFil: López, Daniel Ernesto. Universidad Nacional de Cuyo; ArgentinaFil: Danesi, Rodolfo Francisco. Universidad Nacional de Tucuman. Facultad de Cs.exactas y Tecnología. Laboratorio de Estructuras; Argentin

Border Brutalism

Concepts like freedom and liberty motivate Americans on the global stage. This has racial implications past and present. Exploring these arguments, this Essay: (1) reviews Greg Grandin’s The End of the Myth: From the Frontier to the Border Wall in the Mind of America and (2) proposes a framework to identify law’s place in these motivations. The End of the Myth argues that frontier myths inspired expansion west and then overseas. While this was seen as innately positive, it also downplayed racism. Now, the idea of the border drives Americans and motivates their leaders. With border brutalism policies, a new myth responds to domestic pessimism. This border myth treats racism as an inevitable reality. This Essay proposes a “Brutal Framework” to examine law’s role in this racialization. It identifies how law informs geopolitics, racial consequences, public limits, and policies. In particular, this Essay analyzes judicial rulings regarding borders and admission (Trump v. Hawaii), court powers (DHS v. Thuraissigiam), and violence (Hernández v. Mesa) as examples that provide rationales and normative footing for the border myth. This Essay describes the utility of the Framework beyond these examples. A Framework that moves away from studying security, immigration, economics, and policymaking as separate silos and sees race as a domestic and international issue

Institutional constraints to the development of the Spanish fishing sector (18th and 19th centuries)

Before the steam era, technological limitations restricted the capacity to catch and market fish. Furthermore, a restrictive institutional framework hindered the performance of the Spanish fishing industry. High manufacturing costs attributed to the salt monopoly, restrictions on labour supply caused by the Matrícula de Mar (Maritime Registry), and contradictory legislation contributed to reduced labour participation and investment. The fishing industry was only free from institutional constraints after a long process of dismantling the maritime-fishing regulations of the Ancien Régime at the end of the nineteenth century.Financial support from the Ministerio de Economía, Industria y Compe-titividad AEI/10.13039/501100011033/ and FEDER Un manera de hacer Europa (Project PID2021-124378NB-100) and the Basque Government (Con-solidated Research Group GIC21/38) is gratefully acknowledged