329 research outputs found
Numerische Mathematik / An analysis of the TDNNS method using natural norms
No full textThe tangential-displacement normal-normal-stress (TDNNS) method is a finite element method for mixed elasticity. As the name suggests, the tangential component of the displacement vector as well as the normal-normal component of the stress are the degrees of freedom of the finite elements. The TDNNS method was shown to converge of optimal order, and to be robust with respect to shear and volume locking. However, the method is slightly nonconforming, and an analysis with respect to the natural norms of the arising spaces was still missing. We present a sound mathematical theory of the infinite dimensional problem using the space H(curl) for the displacement. We define the space H––(divdiv) for the stresses and provide trace operators for the normal-normal stress. Moreover, the finite element problem is shown to be stable with respect to the H(curl) and a discrete H––(divdiv) norm. A-priori error estimates of optimal order with respect to these norms are obtained. Beside providing a new analysis for the elasticity equation, the numerical techniques developed in this paper are a foundation for more complex models from structural mechanics such as Reissner Mindlin plate equations, see Pechstein and Schöberl (Numerische Mathematik 137(3):713–740, 2017).Refereed/Peer-reviewedVersion of recor
ASTRID© – Advanced Solar Tubular ReceIver Design: A Powerful Tool for Receiver Design and Optimization
No full textIn solar tower power plants the receiver is one of the critical components. It converts the solar radiation into heat and must withstand high heat flux densities and high daily or even hourly gradients (due to passage of clouds). For this reason, the challenge during receiver design is to find a reasonable compromise between receiver efficiency, reliability, lifetime and cost. There is a strong interaction between the heliostat field, the receiver and the heat transfer fluid. Therefore, a proper receiver design needs to consider these components within the receiver optimization. There are several design and optimization tools for receivers, but most of them focus only on the receiver, ignoring the heliostat field and other parts of the plant. During the last years DLR developed the ASTRID© code for tubular receiver concept simulation. The code comprises both a high and a low-detail model. The low-detail model utilizes a number of simplifications which allow the user to screen a high number of receiver concepts for optimization purposes. The high-detail model uses a FE model and is able to compute local absorber and salt temperatures with high accuracy. One key strength of the ASTRID© code is its interface to a ray tracing software which simulates a realistic heat flux distributions on the receiver surface. The results generated by the ASTRID© code have been validated by CFD simulations and measurement data
Three-field mixed finite element methods for nonlinear elasticity
No full textIn this paper, we extend the tangential-displacement normal-normal-stress continuous (TDNNS) method from Pechstein and Schöberl (2011) to nonlinear elasticity. By means of the Hu-Washizu principle, the distributional derivatives of the displacement vector are lifted to a regular strain tensor. We introduce three different methods, where either the deformation gradient, the Cauchy-Green strain tensor, or both of them are used as independent variables. Within the linear sub-problems, all stress and strain variables can be locally eliminated leading to an equation system in displacement variables, only. The good performance and accuracy of the presented methods are demonstrated by means of several numerical examples
Genreekvilibristen Astrid Lindgren
No full textThe paper examines genre strategies in a number of children’s books by the well-known Swedish author, Astrid Lindgren. Drawing on the reception theories of Hans Robert Jauss, Aidan Chambers and Reinbert Tabbert, the paper demonstrates that the stormy reception of Pippi Longstocking (1945), prompted by a review by Professor John Landquist, had principally genre-related grounds. The book made readers feel a sense of provocation because it challenged their archetextual horizon of expectations by evoking certain traditional genres and simultaneously twisting them in almost anarchic ways. In later books Astrid Lindgren makes a more elaborate use of classic genre structures. She generally chooses one well-known archetext as the generic dominant and allows it to interact with a set of other genres, thus calling forth the main aesthetic effect of the book from the archetextual dialogue between the dominant and the accompanying genres. The paper specifically investigates this polyphonic method in three of Lindgren’s most popular books. In All about the Bullerby children (1947–52) the generic dominant is idyll and the subordinated archetexts satire, parody, burlesque, farce, fairy tale and ballad. Mio, my son (1954) can be considered as an artistic fairy tale (Kunstmärchen), this dominant genre correlating with some other interwoven archetexts: apocryphal gospel, myth, legend, heroic tale and idyll. Finally, the generic dominant of Ronia, the robber’s daughter (1981) – a novel about the adventures of a band of robbers (Räuberroman) – finds its archetextual counterparts in folktale, popular legend, myth, burlesque, fantasy and Bildungsroman, among others
Väckelse, opposition, identitet. Omvändelser hos författaren Astrid Forsberg
No full textMalin Gunnarsson, MA at the Department of Humanities, Comparative Literature, Mid Sweden University Revival, Opposition, Identity: Conversions in Astrid Forsberg’s Novels (Väckelse, opposition, identitet. Omvändelser hos författaren Astrid Forsberg) This essay explores the work of the Swedish author Astrid Forsberg. It focuses on the theme of conversion, which recurs in all ten of her novels. The books were written between 1925 and 1965. Forsberg was born in Bergsjö in 1898. She grew up in a Baptist home and later converted to Catholicism. Before her debut as a fiction writer she was a teacher and a journalist. She also wrote drama and poetry. Forsberg died in Stockholm in 1966. This essay identifies three separate aspects of the conversion theme: Christian, social and individual. The Christian revival conversion functions as a standard model. It is expressed both as a love for Christ and as a life lived in conscientiousness. The social conversion is expressed through opposition, love and Bildung. Finally, the individual conversion is the character’s struggle for a genuine self-image. This essay identifies a shift in Forsberg’s work, from identity creation in a Christian context, to a corresponding identity creation that is secular and individualistic. Subsequently there is a move back, where the characters turn to God again, but from a more individualistic vantage point. These shifts between different ways of identitying creation in Forsberg’s novels have a parallel in the differences between a philosophical and a rhetorical ideal of education, as reflected in the German word Bildung
Wizerunek Astrid Lindgren w polskiej prasie
No full textAstrid Lindgren’s books are present in the Polish publishing market since late 50’s and enjoy unflagging popularity. Numerous press reports intertwined with successive stages of this literary output. Growing interest in the person of the writer was associated with subsequent jubilees, popular books editions, awards, visits to Poland, and finally with sad news of her death on January 28, 2002. The image of Astrid Lindgren in the Polish media, though not always free of some stereotypes, rush typical of today’s media and pursuit for spectacular news, was authentic in many ways. In those interesting vicissitudes, in many statements by the author herself and in observations made by her close friends could be seen her unique character, self-mockery, optimism, natural vitality and love for children
The image of Astrid Lindgren in the Polish press
No full textAstrid Lindgren’s books are present in the Polish publishing market since late 50’s
and enjoy unflagging popularity. Numerous press reports intertwined with successive
stages of this literary output. Growing interest in the person of the writer was associated
with subsequent jubilees, popular books editions, awards, visits to Poland, and finally
with sad news of her death on January 28, 2002. The image of Astrid Lindgren in the
Polish media, though not always free of some stereotypes, rush typical of today’s media
and pursuit for spectacular news, was authentic in many ways. In those interesting vicissitudes,
in many statements by the author herself and in observations made by her close
friends could be seen her unique character, self-mockery, optimism, natural vitality and
love for children
The image of Astrid Lindgren in the Polish press
No full textAstrid Lindgren’s books are present in the Polish publishing market since late 50’s and enjoy unflagging popularity. Numerous press reports intertwined with successive stages of this literary output. Growing interest in the person of the writer was associated with subsequent jubilees, popular books editions, awards, visits to Poland, and finally with sad news of her death on January 28, 2002. The image of Astrid Lindgren in the Polish media, though not always free of some stereotypes, rush typical of today’s media and pursuit for spectacular news, was authentic in many ways. In those interesting vicissitudes, in many statements by the author herself and in observations made by her close friends could be seen her unique character, self-mockery, optimism, natural vitality and love for children
The medium of film in the adaptation of the novel Astrid Lindgren Ronja, the Robber's Daughter
No full textU ovom radu bit će riječi o utjecaju književnog djela na medij filma. Rad upoznaje s glavnim značajkama umjetnosti književnosti, osobito dječje književnosti i filma .
Rad upoznaje s autoricom Astrid Lindgren i njezinim djelovanjem.
Nadalje, analizira radnju dječjeg romana Ronja razbojnička kći i igranog filma jednakog naslova i tematike. Donosi usporedbe i razmišljanja o istovjetnostima i razlikama, odnosima među likovima i utjecajima na čitatelja, odnosno gledatelja.paper will discuss the impact of a literary work on the medium of film. The paper introduces the main features of the art of literature, especially children's literature and film.
The paper introduces the author Astrid Lindgren and her work.
Furthermore, he analyzes the plot of the children's novel Ronja robber's daughter and a feature film of the same title and theme. It brings comparisons and reflections on identities and differences, relationships between characters and influences on the reader or viewer
The TDNNS method for Reissner–Mindlin plates
Get PDFA new family of locking-free finite elements for shear deformable Reissner–Mindlin plates is presented. The elements are based on the “tangential-displacement normal-normal-stress” formulation of elasticity. In this formulation, the bending moments are treated as separate unknowns. The degrees of freedom for the plate element are the nodal values of the deflection, tangential components of the rotations and normal–normal components of the bending strain. Contrary to other plate bending elements, no special treatment for the shear term such as reduced integration is necessary. The elements attain an optimal order of convergence.Refereed/Peer-reviewedVersion of recor
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