109 research outputs found
Serpente-ARRIVE Checklist E10
No full textARRIVE guidelines 2.0: author checklist: The ARRIVE Essential 10.<br
Orthorhombic undoped κ-Ga2O3 epitaxial thin films for sensitive, fast, and stable direct X-ray detectors
No full textPhotoelectronic properties of orthorhombic undoped κ-Ga2O3 epitaxial thin films, grown on sapphire substrates by metal-organic vapour phase epitaxy, were evaluated under X-ray irradiation (CuKα line, 8.05 keV) for the first time. Photoresponse linearity at low dose-rates (varying in the 10-200 μGy s−1 range), and excellent detection sensitivity (up to 342.3 μC Gy−1 cm−3), were demonstrated even at very low applied electric fields (down to 0.001 V μm−1). Photocurrent rise time was evaluated to be <0.5 s, and signal stability was assessed for exposure times up to 2 h, highlighting no degradation of the performance. These encouraging results, mostly due to the extremely low dark current measured (in the pA range), suggest that orthorhombic undoped κ-Ga2O3 is a promising material for the fabrication of sensitive and stable large-area X-ray detectors with minimum power consumption
A Highly Versatile X-ray and Electron Beam Diamond Dosimeter for Radiation Therapy and Protection
No full textRadiotherapy is now recognized as a pillar in the fight against cancer. Two different types are currently used in clinical practice: (1) external beam radiotherapy, using high-energy X-rays or electron beams, both in the MeV-range, and (2) intraoperative radiotherapy, using low-energy X-rays (up to 50 keV) and MeV-range electron beams. Versatile detectors able to measure the radiation dose independently from the radiation nature and energy are therefore extremely appealing to medical physicists. In this work, a dosimeter based on a high-quality single-crystal synthetic diamond sample was designed, fabricated and characterized under low-energy X-rays, as well as under high-energy pulsed X-rays and electron beams, demonstrating excellent linearity with radiation dose and dose-rate. Detector sensitivity was measured to be 0.299 ± 0.002 µC/Gy under 6 MeV X-ray photons, and 0.298 ± 0.004 µC/Gy under 6 MeV electrons, highlighting that the response of the diamond dosimeter is independent of the radiation nature. Moreover, in the case of low-energy X-rays, an extremely low limit of detection (23 nGy/s) was evaluated, pointing out the suitability of the device to radiation protection dosimetry
A ambivalência do simbolismo da serpente em Nm 21,4-9: uma análise na ótica dos conflitos
No full textA perícope das serpentes no deserto destaca-se do conjunto de escritos que recorrem ao simbolismo da serpente, ao utilizar esse elemento potencialmente enganoso para a fé de Israel, ambivalente. Diante disso, o objetivo deste trabalho foi compreender o simbolismo da serpente em Nm 21,4-9, a partir de uma análise do texto e da possível influência por parte dos egípcios e povos do Antigo Oriente Próximo. A análise narrativa destacou o texto como um enredo de conflito-solução no drama vivido pelo povo. Na ótica do conflito, foram levados em conta os aspectos antropológicos e culturais do simbolismo da serpente e seu alcance teológico. A interpretação favoreceu a compreensão da dimensão pedagógica de Deus diante da necessidade de conversão do povo que estava na etapa final da caminhada do deserto, prestes a entrar na terra de Canaã. Dentro da economia da revelação, o autor dá um novo significado à serpente levantada na haste. No início do relato, fora instrumento de castigo expresso na mordedura que causou muitas mortes; no fim, torna-se sinal de salvação. Assim, mediante o sinal, o mesmo Deus que castiga é o que está sempre pronto a oferecer uma nova chance àquele que volta seus olhos para Ele.Palavras-chave: Exegese. Números. Símbolo. Serpente. Conflitos.AbstractThe pericope of the wilderness’ snakes is highlighted in the set of writings using the symbol of the serpent, for this symbol is potentially doubtful to the faith of Israel, ambivalent. Therefore, this paper aims to comprehend the symbolism of the serpent in Numbers 21,4-9, through a text analysis and a study of the possible influence of Egyptians and the nations from Ancient Near Eastern. The narrative analysis highlighted the text as a plot of conflict-solution in the drama lived by the people. In that conflict approach, it was considered the anthropological and cultural features of the serpent symbolism and its theological range. The interpretation favored the comprehension of the pedagogic dimension of God before the necessity of people’s conversion, once they were in the final stage of the wilderness’ pilgrimage, being about to enter at the land of Canaan. In line with the economy of revelation, the author gives a new meaning to the serpent raised in the rod. In the beginning of the report, it was an instrument of punishment expressed in the bite that caused a lot of deaths; at the end, it becomes a sign of salvation. Thus, through this signal, the same God who punishes is the One who is always ready to offer a new chance to those whose eyes turn upon Him.Keywords: Exegesis. Numbers. Symbol. Serpent. Conflicts
Structural and Photoelectronic Properties of κ-Ga2O3 Thin Films Grown on Polycrystalline Diamond Substrates
No full text: Orthorhombic κ-Ga2O3 thin films were grown for the first time on polycrystalline diamond free-standing substrates by metal-organic vapor phase epitaxy at a temperature of 650 °C. Structural, morphological, electrical, and photoelectronic properties of the obtained heterostructures were evaluated by optical microscopy, X-ray diffraction, current-voltage measurements, and spectral photoconductivity, respectively. Results show that a very slow cooling, performed at low pressure (100 mbar) under a controlled He flow soon after the growth process, is mandatory to improve the quality of the κ-Ga2O3 epitaxial thin film, ensuring a good adhesion to the diamond substrate, an optimal morphology, and a lower density of electrically active defects. This paves the way for the future development of novel hybrid architectures for UV and ionizing radiation detection, exploiting the unique features of gallium oxide and diamond as wide-bandgap semiconductors
A ambivalência do simbolismo da serpente em Nm 21,4-9: uma análise na ótica dos conflitos
No full textThe pericope of the wilderness´ snakes is highlighted in the set of writings using the symbol of the
serpent, for this symbol is potentially doubtful to the faith of Israel, ambivalent. Therefore, this paper
aims to comprehend the symbolism of the serpent in Numbers 21,4-9, through a text analysis and a study
of the possible influence of Egyptians and the nations from Ancient Near Eastern. The narrative analysis
highlighted the text as a plot of conflict-solution in the drama lived by the people. In that conflict
approach, it was considered the anthropological and cultural features of the serpent symbolism and its
theological range. The interpretation favored the comprehension of the pedagogic dimension of God
before the necessity of people´s conversion, once they were in the final stage of the wilderness´
pilgrimage, being about to enter at the land of Canaan. In line with the economy of revelation, the author
gives a new meaning to the serpent raised in the rod. In the beginning of the report, it was an instrument
of punishment expressed in the bite that caused a lot of deaths; at the end, it becomes a sign of salvation.
Thus, through this signal, the same God who punishes is the One who is always ready to offer a new
chance to those whose eyes turn upon Him.A perícope das serpentes no deserto destaca-se do conjunto de escritos que recorrem ao simbolismo da
serpente, ao utilizar esse elemento potencialmente enganoso para a fé de Israel, ambivalente. Diante
disso, o objetivo deste trabalho foi compreender o simbolismo da serpente em Nm 21,4-9, a partir de uma
análise do texto e da possível influência por parte dos egípcios e povos do Antigo Oriente Próximo. A
análise narrativa destacou o texto como um enredo de conflito-solução no drama vivido pelo povo. Na
ótica do conflito, foram levados em conta os aspectos antropológicos e culturais do simbolismo da
serpente e seu alcance teológico. A interpretação favoreceu a compreensão da dimensão pedagógica de
Deus diante da necessidade de conversão do povo que estava na etapa final da caminhada do deserto,
prestes a entrar na terra de Canaã. Dentro da economia da revelação, o autor dá um novo significado à
serpente levantada na haste. No início do relato, fora instrumento de castigo expresso na mordedura que
causou muitas mortes; no fim, torna-se sinal de salvação. Assim, mediante o sinal, o mesmo Deus que
castiga é o que está sempre pronto a oferecer uma nova chance àquele que volta seus olhos para Ele
Improving the performance of printable carbon electrodes by femtosecond laser treatment
No full textLow-cost carbon-conductive films were screen-printed on a Plexiglas® substrate, and then, after a standard annealing procedure, subjected to femtosecond (fs) laser treatments at different values of total accumulated laser fluence ΦA. Four-point probe measurements showed that, if ΦA > 0.3 kJ/cm2, the sheet resistance of laser-treated films can be reduced down to about 15 Ω/sq, which is a value more than 20% lower than that measured on as-annealed untreated films. Furthermore, as pointed out by a comprehensive Raman spectroscopy analysis, it was found that sheet resistance decreases linearly with ΦA, due to a progressively higher degree of crystallinity and stacking order of the graphitic phase. Results therefore highlight that fs-laser treatment can be profitably used as an additional process for improving the performance of printable carbon electrodes, which have been recently proposed as a valid alternative to metal electrodes for stable and up-scalable perovskite solar cells
Low Electron Affinity Silicon/Nanocrystalline Diamond Heterostructures for Photon-Enhanced Thermionic Emission
No full textPhoton-enhanced thermionic emission (PETE) is a physical mechanism based on the electron’s emission from photon absorption and thermalization, which can be highly efficient to convert concentrated sunlight. Here, we demonstrate that nanocrystalline diamond thin films deposited on heavily doped p-type silicon absorbers can be potentially efficient PETE cathodes, showing a low χ value of ∼0.4 eV. A detailed analysis has been carried out as a function of the film thickness by correlating the PETE performance under concentrated sunlight with several chemical–physical measurements. The results highlight that grain boundaries are decisive to achieve the highest emission current density obtained with an 80 nm-thick emitter
Kant e a ideia de uma história universal nos limites da razão
No full textTese (doutorado) - Universidade Federal de Santa Catarina, Centro de Filosofia e Ciências Humanas. Programa de Pós-Graduação em FilosofiaA presente tese procura oferecer uma interpretação abrangente e sistemática da filosofia da história de Immanuel Kant. Nessa perspectiva defende-se três posições: primeira, que Kant sustenta nos textos histórico-políticos a possibilidade do progresso de uma virtude moral; segunda, que o projeto de uma história universal se assenta essencialmente sobre a perspectiva prática da faculdade de julgar reflexionante; e terceira, que a história universal constitui uma parte indispensável de uma imagem moral do mundo e da arquitetônica da razão pura.The present PhD dissertation attempts to provide a comprehensive and systematic interpretation of Immanuel Kant's philosophy of history and will defend three main positions: first, that Kant sustains in his historical-political works the possibility of the progress of a moral virtue; second, that the project of a universal history is grounded essentially in a practical perspective of reflective judgment; third, that a universal history constitutes an indispensable part of a moral image of the world as well as of the architectonic of pure reason
Agora a serpente sorrateira anda: o diabólico como uma força criadora em O Casamento do Céu e do Inferno, de William Blake
No full text: In The Marriage of Heaven and Hell (1790-1793), William Blake offers a trail to fly through the Universe. His muse, the “sneaking serpent”, elucidates the concept that diabolic does not contain in itself the idea of evil – nevertheless it is an active springing from Energy, for every existence is holy. This study understands the prophetic trip narration to mystery as a way that the poetic voice erects against Reason (Good), to empower himself in the Energy of Devil (or of Hell). Hereby, it was adopted the idea of devilish as a vital force, avoiding dogmatic and religious definitions of the term, a thematic often struggled by the author, mainly concerning his rupture with the thoughts of Emanuel Swedenborg. Another point that was researched was in relation to distinct visual representations of the serpent myth in Blake’s illustrations, as in “The Serpent Attacking Buoso Donatin” (1826–7, reprinted in 1892), and in “The spiritual of Nelson guiding Leviathan” (1805-1809). Both in written and pictorial artworks, the author asserts that the serpent symbolizes the sacred that lives in all profane things.Em O Casamento do Céu e do Inferno (1790-1793), William Blake oferece uma trilha para voar pelo Universo. A sua musa, a “serpente sorrateira”, elucida o conceito de que o diabólico não contém em si a ideia do mal - no entanto, é uma nascente ativa da Energia, pois toda existência é sagrada. Este estudo entende a viagem profética da narração em direção ao mistério como uma forma que a voz poética ergue contra a Razão (Bem), para se empoderar na Energia do Diabo (ou do Inferno). Adotou-se, assim, a ideia do diabólico como força vital, evitando-se definições dogmáticas e religiosas do termo, temática com a qual o autor muitas vezes se debatiava , principalmente no que diz respeito a sua ruptura com o pensamento de Emanuel Swedenborg. Outro ponto pesquisado foi em relação às distintas representações visuais do mito da serpente nas ilustrações de Blake, como em "A Serpente Atacando Buoso Donatin" (1826-7, reimpresso em 1892) e em "O espiritual de Nelson guiando o Leviatã" ( 1805-1809). Tanto em obras escritas quanto pictóricas, o autor afirma que a serpente simboliza o sagrado que vive em todas as coisas profanas
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