Atomic-scale computer simulation has been used to study the thermally activated atomic transport of self-interstitial atoms in the form of planar clusters in pure Cu and f -Fe. There is strong evidence that such clusters are commonly formed in metals during irradiation with high-energy particles and play an important role in accumulation and spatial distribution of surviving defects. An extensive study of the mobility of SIA clusters containing two to 331 interstitials has been carried out using the molecular dynamics simulation (...) technique for the temperature range from 180 to 1200 K. The results obtained show that clusters larger than three to four SIAs are one-dimensionally mobile in both Cu and Fe. Large clusters of more than 100 SIAs in Cu and 300 SIAs in Fe have significantly reduced mobility. The problem of describing one-dimensional motion in three-dimensional space is discussed. An attempt is made to describe the mobility of SIA clusters within the approximation of 1D diffusion. For clusters in both metals the effective migration energy of 1D diffusion as estimated via the jump frequency of the cluster centre of mass is found to be independent of the number of SIAs in the clusters, although the cluster jump frequency decreases with increasing cluster size. Mechanisms of 1D mobility of interstitial clusters are discussed. (shrink)

Born in Granada, April 30, 1901, Antonio De Luna was educated in the universities of Granada and of Madrid, continued his studies at Freiburg in Bresgovia, Paris, and Oxford and received the doctorate in law from Bologna. At the age of 27 he was appointed to the chair of natural law at the University of La Laguna in the Canary Isles, and from there went on to Salamanca and Granada. In 1932 he obtained the chair of international public law of (...) the Faculty of Law of the University of Madrid. At this time he began a period of intense professional activity: He was Secretary of the Federation of Spanish Associations of International Studies (1932–1936), founder and director of the Institute of International and Economic Studies (1932–1936), and Secretary of the Juridical Assessory Commission of the Spanish Republic (1931–1934). After the interruption of the Civil War, Luna, with a sense of continuity, resumed his essential tasks. (shrink)

Este artigo enfoca o modo como a teoria husserliana da lembrança se insere, por um lado, na estrutura significativa formulada primeiramente nas Investigações lógicas e, por outro, nos moldes da percepção como unidade temporal. Para tanto, apresenta-se, respectivamente na primeira e na segunda seções, o arcabouço das teorias husserlianas da significação e da percepção como retenção. Na terceira seção, é analisada a segunda forma de lembrança — a rememoração —, segundo o fio condutor em que Husserl a investiga nos contextos (...) da atenção, retenção, afecção e inconsciente. Finalmente, será considerado se o núcleo teórico da primazia do significado e do fluxo da consciência é, de fato, uma base propícia para a compreensão da lembrança em seu caráter de signo. --------------------------------------------------------------------------- This paper focuses on how Husserl's theory of memory is introduced, both in his significant structure, that was first formulated in the Logical Investigations and in the patterns of perception as a temporal unit. The first and second sections show, respectively, the framework of Husserl's theories of meaning and perception as retention. In the third section, the second mode of memory — recollection — is analyzed according to the thread that Husserl investigates in the contexts of attention, retention, affection and unconscious. Finally, we will consider whether the theoretical core of the primacy of meaning and the flow of consciousness is, in fact, an adequate basis for the comprehension of memory as a sign. (shrink)

RESUMO: Este texto aborda alguns trabalhos contemporâneos em artes visuais que apresentam diferentes relações e disposições de um material dito natural: pedras. Ao retomar as distinções explicitadas por Heidegger, entre meras coisas, utensílio e obra de arte, bem como entre a pedra, o animal e o homem em relação ao mundo, serão discutidos deslocamentos acerca dessas distinções, com base em apontamentos da desconstrução. Pretende-se indicar alguns dos sentidos em que os enfoques desconstrutivos são frutíferos, para se pensar movimentos contemporâneos no (...) âmbito do que Derrida denomina artes do espaço. ABSTRACT: This text approaches some contemporary works in the visual arts which present different relations and dispositions of a material taken to be natural: stone. I intend to revisit the distinctions presented by Heidegger between mere things, utensils and works of art, as well as between stone, animal and man in connection with the world. Furthermore, I will discuss dislocations regarding such issues, based on indications from deconstruction. I aim to indicate some of the meanings under which deconstructive approaches are fruitful for thinking about contemporary movements within the scope of what Derrida calls "spatial arts". (shrink)

RESUMO Este texto discute alguns problemas metodológicos e históricos concernentes à fenomenologia da consciência de imagem elaborada por Edmund Husserl e algumas de suas repercussões teóricas. Primeiramente será tematizado o escopo mais amplo em que a abordagem filosófica das imagens auferiu relevância no século XX, a saber, a assim chamada “virada icônica” ou “pictórica”, conforme as respectivas formulações de Gottfried Boehm e William Mitchell. Será situada nesse contexto a fenomenologia da imagem e, mais especificamente, a fenomenologia da consciência de imagem (...) elaborada por Husserl, considerando-se, em especial, os eixos norteadores dos três direcionamentos que sobressaem nas teorias contemporâneas da imagem, a saber: as abordagens antropológica, semiótica e perceptiva. A partir da retomada de nuances semióticas remanescentes na fenomenologia da consciência de imagem, serão apresentados alguns pontos críticos acerca da classificação das análises de Husserl no escopo do direcionamento perceptivo e, finalmente, apontadas implicações do copertencimento à apresentação intuitiva da imagem daquilo que se denominará “circunstancialidade indicativa”. ABSTRACT This text addresses some methodological and historical problems concerning the phenomenology of image consciousness elaborated by Edmund Husserl as well as some of its theoretical repercussions. At first, I examine the broader scope in which the philosophical approach to images became relevant in the 20th century, the so-called “iconic turn” or “pictorial turn”, according to the respective terms proposed by Gottfried Boehm and William Mitchell. In this context I situate the phenomenology of image and, more specifically, the phenomenology of image consciousness elaborated by Husserl, considering, in particular, the guiding axes of three directions that stand out in contemporary theories of image, namely: the anthropological, the semiotic and the perceptual approach. By the resumption of semiotic nuances remaining in the phenomenology of image consciousness I present some critical points about the classification of Husserl’s analyses in the scope of perceptual approach. Finally, I point out some implications of the co-belonging to the intuitive image presentation of what can be called “indicative circumstantiality”. (shrink)

O presente trabalho utiliza a chamada “concepção semântica” das teorias físicas para examinar o estudo realizado por Descartes sobre o fenômeno do arco-íris. Essa concepção parece ser a mais adequada para esse caso, tendo em vista o privilégio dos modelos na abordagem cartesiana. Nesse sentido, não parece ser possível concluir que esse estudo se configure como uma teoria física, como estimam alguns autores, embora Descartes tenha obtido valores corretos para o raio do arco-íris,ao fazer uso da lei de refração.