Pulsed electrically detected magnetic resonance (pEDMR) was employed to study spin-dependent processes that influence charge transport in microcrystalline silicon (µc-Si:H) pin solar cells. Special emphasis was put on the identification of the signals with respect to the individual layers of the cell structure. To do this, we systematically modulated the morphology of the highly doped n- and p-layers from amorphous to microcrystalline. By combining the information obtained from low-temperature (T = 10 K) pEDMR spectra and from the deconvoluted time evolution (...) of spectrally overlapping resonances, we found signals from conduction band tail states as well as phosphorus donor states in samples containing an amorphous n-type layer and a resonance associated with valence band tail states in samples with an amorphous p-layer. Moreover, several signals from the intrinsic microcrystalline absorber layers could be identified. An additional resonance at g = 1.9675(5), which has not been observed in EDMR before, was found. We assign this signal to shallow donors in the Al-doped ZnO layer, which is commonly used as transparent conducting oxide in thin-film solar cells. The experimental findings are discussed in the light of various spin-dependent transport mechanisms known to occur in the respective layers of the pin structure. (shrink)
En el presente artículo intentaremos aproximarnos a uno de los textos más emblemáticos del pensamiento de Schelling, Las Edades del Mundo (Die Weltalter), escrito entre 1813-1815, donde se encuentra todo el misterio de la filosofía medía de este autor que va desde el Ensayo de la libertad de 1809 hasta su reaparición en Munich y posteriormente en Berlín, donde sustituirá a Hegel a su muerte y formulará su famosa filosofía positiva, constituida por su Filosofía de la Mitología y de la (...) Revelación, como alternativa al pensamiento hegeliano. Intentaremos acercarnos a esa nueva noción de ciencia positiva a partir de un análisis del concepto de ¿crisis¿,... (Ver más) tematizado por Schelling en Las Edades del Mundo, en relación con una posible filosofía de la memoria. (shrink)
Le programme de publication des historiens ecclésiastiques, commencé dès les premiers volumes de la collection Sources Chrétiennes avec l’œuvre d’Eusèbe de Césarée, s’enrichit d’un nouveau titre (deux volumes prévus, pour les livres I-II, puis pour les livres III à V). Théodoret de Cyr, au 5e siècle, se présente d’emblée, comme Socrate de Constantinople, en continuateur de l’Histoire ecclésiastique d’Eusèbe de Césarée. Les 5 livres de son Histoire, dont la rédaction est achevée à la fin des a..
Resenha do livro de Juan Adolfo Bonaccini, Maria de Paz Nunes Medeiros, Markus Figueira de Silva e Oscar Frederico Bauchwitz (Org.). Metafísica: história e problemas: atas do I Colóquio Internacional da Metafísica . Natal: EDUFRN, 2006, 332 páginas. [Coleçáo Metafísica n. 5].
Short historical and cultural sketch of Frances decisive years during the Second World War, between occupation and resistance, re f racted by the prism of the Sartrean figure of the engagé intellectual, which was born out of this conjuncture of sharp political crisis. This sketch, however, is extracted out of my analysis of the int e r nal organization of what seems to be, at first sig ht, Sartres most d i s e ng a ged work, one that was (...) cons e c rated by tradition as a cons t e l l a t ion of ideas shining on the sky of pure philosophy Being and Nothingness. (shrink)
Both cognitive science and phenomenology accept the primacy of the organism-environment system and recognize that cognition should be understood in terms of an embodied agent situated in its environment. How embodiment is seen to shape our world, however, is fundamentally different in these two disciplines. Embodiment, as understood in cognitive science, reduces to a discussion of the consequences of having a body like ours interacting with our environment and the relationship is one of contingent causality. Embodiment, as understood phenomenologically, represents (...) the condition of intelligibility of certain terms in our experience and, as such, refers to one aspect of that background which presupposes our understanding of the world. The goals and approach to modeling an embodied agent in its environment are also fundamentally different dependent on which relationship is addressed. These differences are highlighted and are used to support our phenomenologically based approach to organism-environment interaction and its relationship to brain function. (shrink)
In this article, I critically analyze the anthropological foundation of the bioethics of philosopher Jean-François Malherbe, particularly as presented in his book, Pour une Éthique de la Médecine. Malherbe argues that such practices as organ donation and transplants, assisted reproduction, resuscitation, and other uses of biotechnologies in contemporary medicine are unethical because they go against essential human nature. Furthermore, he uses this position as a basis to prescribe public policy and institutional practice. In contrast, I argue not only that ‘human (...) nature’ is much more malleable and adaptive to changes in technology and society than Malherbe allows, but also that his criticisms of medicine and technoscientific development overstep the bounds of the social function of philosophical ethics, which is to inform and clarify public debate. Public policy and institutional practice is thus best left to the democratic political process under the parameters of the just rule of law. (shrink)
La historia del idealismo alemán se articula en torno a una serie de encuentros y desencuentros entre quienes pretenden completar una obra que habría quedado inacabada, y que conduciría a una suerte de constitución definitiva de la filosofía. La correspondencia intercambiada entre I. Kant, J. G. Fic..