Americanization now and then: the 'nation of immigrants' in the early twentieth and twenty-first centuries

In an analysis of contemporary attempts at US immigration reform in the context of its legal history (especially John F. Kennedy's 1964 Immigration and Nationality Act) this article explores a fundamental paradox in American political thought and practice as regards immigration. It examines the tension between the US's insistence, on one hand, upon immigrants' swift and wholesale integration into American life (as exemplified in the early 20th C Americanization programme, echoed in a 2007 call for a renewed Americanization initiative under President George W. Bush) and its self- definition as a proud 'nation of immigrants' on the other. In so doing, the essay critiques the 'nation of immigrants' shibboleth for its implicit racist bias and introduces the concept of 'ethnic shame,' prevalent for most of the 20th C, to complement today's much more familiar (but also much more recent) notion of Americans' ethnic pride in their immigrant roots. The article concludes that the ostensible paradox of a 'nation of immigrants' insisting on Americanization is best understood within the framework of what is theorised here for the first time as the 'gratitude paradigm,' which governs the granting and the possession of American citizenship to immigrants not just of the first, but of many generations thereafter

Discretization of sea ice dynamics in the tangent plane to the sphere by a CD-grid-type finite element

We present a new discretization of sea ice dynamics on the sphere. The approach describes sea ice motion in tangent planes to the sphere. On each triangle of the mesh, the ice dynamics are discretized in a local coordinate system using a CD-grid-like non-conforming finite element method. The development allows a straightforward coupling to the C-grid like ocean model in Icosahedral Non-hydrostatic-Ocean model, which uses the same infrastructure as the sea ice module. Using a series of test examples, we demonstrate that the non-conforming finite element discretization provides a stable realization of large-scale sea ice dynamics on the sphere. A comparison with observation shows that we can simulate typical drift patterns with the new numerical realization of the sea ice dynamics. © 2022 The Authors. Journal of Advances in Modeling Earth Systems published by Wiley Periodicals LLC on behalf of American Geophysical Union

A goal oriented error estimator and mesh adaptivity for sea ice simulations

For the first time we introduce an error estimator for the numerical approximation of the equations describing the dynamics of sea ice. The idea of the estimator is to identify different error contributions coming from spatial and temporal discretization as well as from the splitting in time of the ice momentum equations from further parts of the coupled system. The novelty of the error estimator lies in the consideration of the splitting error, which turns out to be dominant with increasing mesh resolution. Errors are measured in user specified functional outputs like the total sea ice extent. The error estimator is based on the dual weighted residual method that asks for the solution of an additional dual problem for obtaining sensitivity information. Estimated errors can be used to validate the accuracy of the solution and, more relevant, to reduce the discretization error by guiding an adaptive algorithm that optimally balances the mesh size and the time step size to increase the efficiency of the simulation

The effect of the tracer staggering on sea ice deformation fields

Sea ice models can simulate linear deformation characteristics (linear kinematic features) that are observed from satellite imagery. A recent study based on the viscous-plastic sea ice model highlights the role of the velocity placement on the simulation of linear kinematic features (LKFs) and concluded that the tracer staggering has a minor influence on the amount simulated LKFs. In this work we consider the same finite element discretization and show that on triangular meshes the placement of the sea ice tracers and the associated degrees of freedom (DoFs) have a strong influence on the amount of simulated LKFs. This behaivor can be explained by the change of the total number of DoFs associated with the tracer field. We analyze the effect on a benchmark problem and compare P1-P1, P0-P1, CR-P0 and CR-P1 finite element discretizations for the velocity and the tracers, respectively. The influence of the tracer placement is less strong on quadrilateral meshes as a change of the tracer staggering does not modify the total number of DoFs. Among the low order finite element approximations compared in this study, the CR-P0 finite element discretization resolves the deformation structure in the best way. The CR finite element for velocity in combination with the P0 discretization for tracer produces more LKFs than the P1-P1 finite element pair even on grids with fewer DoFs. This can not be achieved with the CR-P1 setup and therefore highlights the importance of the tracer discretization for the simulation of LKFs on triangular meshes

História da Palestina nos tempos do Novo Testamento (IV)

 A posição jurídica de Herodes. Extensão e limites de seu poder.

História da Palestina nos tempos do Novo Testamento (III)

História da Palestina nos tempos do Novo Testamento (III