La fontaine bouillonnante et la tombe de Lancelot l'Ancien: modalités textuelles et iconographiques de la construction cyclique dans le Lancelot-Graal

La tête du roi Lancelot l'Ancien, l'aïeul du chevalier Lancelot, assassiné par le duc de Belle Garde, est plongée dans une fontaine merveilleuse bouillonnante, tandis que son corps, gardé par deux lions, est conservé dans un tombeau extraordinaire dont suintent des gouttes de sang aux propriétés curatives. Sur le plan textuel, les références aux merveilles qui suivent la mort de Lancelot l'Ancien dans l'Estoire del saint Graal, le Lancelot et la Queste del Saint Graal témoignent de la construction du cycle du Lancelot-Graal par l'intégration d'une dimension à la fois historique et généalogique. Or l'iconographie des manuscrits enluminés du cycle du Graal privilégie davantage la mise en série d'épisodes apparentés que la construction d'une logique véritablement cyclique. Le remploi de compositions ou de motifs iconographiques renforce la cohérence de l'univers chevaleresque et merveilleux ainsi créé sans pour autant impliquer d'effet de circularité.

Entre histoire et fiction: la représentation du règne d'Arthur dans le manuscrit enluminé du Brut en prose, Londres, Lambeth Palace 6 (c. 1480)

The manuscript London, Lambeth Palace 6, contains the Middle English prose Brut, a text which benefited from a great popularity throughout the fifteenth century. It was copied by an English scribe and richly illuminated by the Master of Edward IV and his assistants at Bruges around 1480. This article studies the representation and integration of the reign of Arthur in the historical framework of the Brut or Chronicles of England, including its fictional aspects: Arthur emerges as a historical character but also as a chivalric and mythical figure. The analysis covers the miniatures ranging from the plot leading to the conception of Arthur to the end of his reign (fols. 36-66). The textual and iconographic choices of the prose Bruts are highlighted by comparisons with Geoffrey of Monmouth’s Historia Regum Britanniae, Wace’s Brut, and later prose rewritings in the Lancelot-Grail romance cycle, especially Merlin and its Vulgate Sequel. They show the continuous interest raised by Arthur in the aristocratic and royal circles of late fifteenth century England and the relationship be¬tween continental and insular historiographical, literary and artistic traditions.

Arthur et ses barons rebelles: la fin remaniée et abrégée de la Suite Vulgate dans le manuscrit du cycle du Graal, Paris, BNF fr. 344

The ms. Paris, BnF, fr. 344 was produced in Lorraine at the end of the thirteenth century and contains the whole Lancelot-Grail cycle. It presents an abridged version of the end of the Vulgate Sequel to Merlin. The rewriting of the end of the sequel glosses over the romantic episodes of the common version and focuses on the figure of Arthur, a legitimate sovereign and skilful war leader confronted by his barons’ dissidence. From the end of f° 182 to f° 184v°, BnF, fr. 344, narrates the departure of Kings Ban and Bohort for the Continent, the embassy of King Loth and his sons, and the fight against the Saxons of the Christian coalition gathered at Logres for the feast of the Holy Cross. This article shows the ideological implications of the abridgement and the illustration used at the end of the Vulgate Sequel in ms. fr. 344, as it exalts Arthur’s kingship and insists on the rallying, penance and submission of his rebelled vassals.

L’illustration marginale d’un ouvrage profane : étude du manuscrit Paris, Bibliothèque nationale de France, français 95, xiiie siècle (1290)

BnF fr. 95 is a late 13th century manuscript containing Arthurian romances and other fictional and didactic texts. The Estoire del saint Graal and Merlin section is the most highly illuminated, with a rich marginal iconography, an unusual feature in the illustration of lay works and in these texts’ manuscript tradition. This article shows how in Merlin and its Vulgate Sequel marginal scenes overlap with widespread subjects in courtly and chivalric vernacular romances, in contrast with Latin and religious works. The reuse of similar patterns in principal and marginal miniatures, examined in the episode of the Battle of Danablaise, where King Arthur fights the Saxon King Rion, highlights the need for a comprehensive reading of text and images, taking into account the mise en page and the different levels of illustration in the manuscript.

GHASP: an H alpha kinematic survey of spiral and irregular galaxies - IX. The near-infrared, stellar and baryonic Tully-Fisher relations

We studied, for the first time, the near-infrared, stellar and baryonic Tully-Fisher relations for a sample of field galaxies taken from a homogeneous Fabry-Perot sample of galaxies [the Gassendi HAlpha survey of SPirals (GHASP) survey]. The main advantage of GHASP over other samples is that the maximum rotational velocities were estimated from 2D velocity fields, avoiding assumptions about the inclination and position angle of the galaxies. By combining these data with 2MASS photometry, optical colours, HI masses and different mass-to-light ratio estimators, we found a slope of 4.48 +/- 0.38 and 3.64 +/- 0.28 for the stellar and baryonic Tully-Fisher relation, respectively. We found that these values do not change significantly when different mass-to-light ratio recipes were used. We also point out, for the first time, that the rising rotation curves as well as asymmetric rotation curves show a larger dispersion in the Tully-Fisher relation than the flat ones or the symmetric ones. Using the baryonic mass and the optical radius of galaxies, we found that the surface baryonic mass density is almost constant for all the galaxies of this sample. In this study we also emphasize the presence of a break in the NIR Tully-Fisher relation at M(H,K) similar to -20 and we confirm that late-type galaxies present higher total-to-baryonic mass ratios than early-type spirals, suggesting that supernova feedback is actually an important issue in late-type spirals. Due to the well-defined sample selection criteria and the homogeneity of the data analysis, the Tully-Fisher relation for GHASP galaxies can be used as a reference for the study of this relation in other environments and at higher redshifts.

All-optical switching device for infrared based on PbTe quantum dots

Multilayers of PbTe quantum dots embedded in SiO2 were fabricated by alternate use of Pulsed Laser Deposition (PLD) and Plasma Enhanced Chemical Vapor Deposition (PECVD) techniques. The morphological properties of the nanostructured material were studied by means of High Resolution Transmission Electron Microscopy (HRTEM), Grazing-Incidence Small-Angle X-ray scattering (GISAXS) and X-ray Reflectometry (XRR) techniques. A preliminary analysis of the GISAXS spectra provided information about the multilayer periodicity and its relationship to the size of the deposited PbTe nanoparticles. Finally multilayers were fabricated inside a Fabry-Perot cavity. The device was characterized by means of Scanning Electron Microscopy (SEM). Transmittance measurements show the device functionality in the infrared region. (C) 2007 Elsevier Ltd. All rights reserved.

Sensores em fibra óptica para monitorização ambiental

Fruto da crescente preocupação face à bioacumulação e bioconcentração de poluentes e conscientização dos efeitos do aquecimento global, nos últimos anos têm sido adoptadas inúmeras acções e medidas que visam o controlo de parâmetros indicadores da qualidade do meio, a detecção de substâncias potencialmente perigosas e a promoção/utilização de energias alternativas não poluentes. Neste âmbito, a monitorização em tempo real revela-se fundamental para a análise contínua do equilíbrio dos ecossistemas. Neste contexto, os sensores de fibra óptica, mais concretamente os sensores químicos em fibra óptica possuem um conjunto de características, como por exemplo a miniaturização, baixo custo, versatilidade, biocompatibilidade, capacidade de monitorização remota, que representam uma alternativa tecnológica e economicamente viável. Por outro lado, a utilização de redes de difracção em sensores de fibra óptica, é em adição uma mais-valia para este tipo de sistemas, as redes de período longo pela sua sensibilidade intrínseca ao índice de refracção, e as redes de Bragg pela sua facilidade de interrogação e facilidade de multiplexagem. A presente dissertação tem por objectivo o estudo, desenvolvimento e análise de sensores em fibra óptica para monitorização de espaços ambientais. O presente documento encontra-se organizado em cinco capítulos. O capítulo 1 faz um enquadramento dos sensores de fibra óptica para monitorização ambiental dando relevo aos sensores químicos em fibra óptica. No capítulo 2 expõe-se o conjunto de conceitos necessários para a compreensão do trabalho. A começar pelas redes de difracção em fibra óptica e a suas potencialidades como elementos sensores. Algumas configurações foram detalhadas assim como alguns princípios para interrogação das mesmas. A medição multi-parâmetro e o fabrico de membranas de sensibilidade selectiva são também abordados. O Capitulo 3 refere a primeira configuração desenvolvida, trata-se de um sensor interferométrico baseado numa cavidade Fabry-Pérot, constituído por uma rede de Bragg e a reflectividade da ponta da fibra. O objectivo do sensor é a monitorização do ácido acético e outras espécies carboxílicas em bioreactores. Para tornar a configuração sensível ao ácido foi aplicado um revestimento de Silane-PVP à extremidade da fibra. A configuração sensora demonstrada aufere de características favoráveis, como excelente resolução, resposta linear, não utilização de indicadores, leitura em reflexão e o facto de operar na janela espectral das telecomunicações. O Capítulo 4 apresenta a segunda configuração desenvolvida que tem por objectivo a medição simultânea de salinidade e temperatura. A medição de salinidade é baseada no índice de refracção. Trata-se de um sensor de intensidade auto-referenciado, baseado em três redes de difracção. Uma rede de período longo sensível ao índice de refracção e temperatura e duas redes de Bragg, para interrogação da da rede de período longo e compensação de temperatura. Para discriminação dos parâmetros de interesse foi utilizado o método matricial. A configuração exposta exibe características favoráveis, como excelente resolução, resposta linear, discriminação de índice de refracção e temperatura, leitura em reflexão e o facto de operar na janela espectral das telecomunicações. O Capitulo 5 contém as conclusões e comentários finais ao trabalho. No final da tese seguem-se os anexos, onde se encontram as publicações e comunicações resultantes do trabalho realizado.

Death of two slender-billed parakeet (King) (Enicognathus leptorhynchus) (Aves, Psittacidae) by Ascaridia hermaphrodita (Froelich, 1789, Railliet & Henry, 1914) at the National Zoo of Santiago, Chile

No Zoológico Nacional do Parque Metropolitano de Santiago, Chile, foram encontrados dois psitacídeos Enicognathus leptorhynchus, mortos pelo nematódeo Ascaridia hermaphrodita (Froelich, 1789). Este é o primeiro registro desse nematódeo em E. leptorhynchus e também o primeiro registro deste parasito no Chile.

Metamaterial inspired improved antennas and circuits

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

DCOOD optically pumped by a (CO2)-C-13 laser: new terahertz laser lines

In this work we report on new optically pumped THz laser lines from deuterated formic acid (DCOOD). An isotopic (CO2)-C-13 laser was used for the first time as a pump source for this molecule, and a Fabry-Perot cavity was used as a THz laser resonator. Optoacoustic absorption spectra were used as a guide to search for new THz laser lines. We could observe six new laser lines in the range from 303.8 mu m (0.987 THz) to 725.1 mu m (0.413 THz). The lines were characterized according to wavelength, relative polarization, relative intensity, and optimum working pressure. The transferred lamb-dip technique was used to measure the frequency absorption transition for both of these laser lines. Furthermore, we also present a catalogue of all THz laser lines generated from DCOOD.

Enhanced multiwavelength holographic profilometry by laser mode selection

A method for improving the accuracy of surface shape measurement by multiwavelength holography is presented. In our holographic setup, a Bi12TiO20 photorefractive crystal was the holographic recording medium, and a multimode diode laser emitting in the red region was the light source in a two-wave mixing scheme. on employing such lasers the resulting holographic image appears covered with interference fringes corresponding to the object relief, and the interferogram spatial frequency is proportional to the diode laser's free spectral range (FSR). Our method consists in increasing the effective free spectral range of the laser by positioning a Fabry-Perot etalon at the laser output for mode selection. As larger effective values of the laser FSR were achieved, higher-spatial-frequency interferograms were obtained and therefore more sensitive and accurate measurements were performed. The quantitative evaluation of the interferograms was made through the phase-stepping technique, and the phase map unwrapping was carried out through the cellular-automata method. For a given surface, shape measurements with different interferogram spatial frequencies were performed and compared with respect to measurement noise and visual inspection. (c) 2007 Society of Photo-Optical Instrumentation Engineers.

Photopatternable di-ureasil-zirconium oxocluster organic-inorganic hybrids as cost effective integrated optical substrates

Organic-inorganic hybrids containing methacrylic acid (McOH, CH(2)= C(CH(3))COOH)) modified zirconium tetrapropoxide, Zr(OPr(n))(4), classed as di-ureasil-zirconium oxo-cluster hybrids, have been prepared and structurally characterized by X-ray diffraction (XRD), small-angle X-ray scattering (SAXS), Fourier transform infrared (FT-IR) and Raman (FT-Raman) spectroscopies, Si and C nuclear magnetic resonance (NMR), and atomic force microscopy (AFM). XRD and SAXS results have pointed out the presence of Si- and Zr-based nanobuilding blocks (NBBs) dispersed into the organic phase. Inter-NBBs correlation distances have been estimated for the pure di-ureasil and a model compound obtained. by hydrolysis/condensation of Zr(OPr(n))(4):McOH (molar ratio 1: 1): d(Si) approximate to 26 +/- 1 angstrom and d(Zr) approximate to 16 +/- 1 angstrom, respectively. In the case of the di-ureasil-zirconium oxo-cluster hybrids, these distances depend on the Zr relative molar percentage (rel. mol. Zr %) (d(Si) ranges from 18 to 25 angstrom and d(Zr) from 14 to 23 angstrom, as the rel. mol. Zr % increases from 5 to 75), suggesting that the Si- and Zr-based clusters are interconstrained. Complementary data from FT-IR, FT-Raman, (29)Si and (13)C NMR, and AFM support to a structural model where McOH-modified Zr-based NBBs (Zr-OMc) are present over the whole range of composition. At low Zr-OMc contents (rel. mol. Zr % <30) the clusters are well-dispersed within the di-ureasil host, whereas segregation occurs at the 0.1 mu m scale at high Zr-OMc concentration (rel. mol. Zr % = 50). No Zr-O-Si heterocondensation has been discerned. Monomode waveguides, diffractions gratings, and Fabry-Perot cavities have been written through the exposure of the hybrid monoliths to UV light. FT-Raman has shown that the chemical process that takes place under illumination is the polymerization of the methacrylate groups of the Zr-OMc NBBs. The guidance region in patterned channels is a Gaussian section located below the exposed surface with typical dimensions of 320 mu m wide and 88 mu m deep. The effective refractive index is 1.5162 (maximum index contrast on the order of 1 x 10(-4)) and the reflection coeficient of the Fabry-Perot cavity (formed by a grating patterned into a 0.278 cm channel) is 0.042 with a free spectral range value of 35.6 GHz.