998 resultados para (900 1170) °C
Resumo:
Este trabalho apresenta um mtodo para reconhecimento do padro na biodisponibilidade do ferro, atravs da interao com substncias que auxiliam a absoro como vitamina C e vitamina A e nutrientes inibidores como clcio, fitato, oxalato, tanino e cafena. Os dados foram obtidos atravs de inqurito alimentar, almoo e jantar, em crianas de 2 a 5 anos da nica Creche Municipal de Paraty-RJ entre 2007 e 2008. A Anlise de Componentes Principais (ACP) foi aplicada na seleo dos nutrientes e utilizou-se o Algoritmo Fuzzy C-Means (FCM) para criar os agrupamentos classificados de acordo com a biodisponibilidade do ferro. Uma anlise de sensibilidade foi desenvolvida na tentativa de buscar quantidades limtrofes de clcio a serem consumidas nas refeies. A ACP mostrou que no almoo os nutrientes que explicavam melhor a variabilidade do modelo foram ferro, vitamina C, fitato e oxalato, enquanto no jantar o clcio se mostrou eficaz na determinao da variabilidade do modelo devido ao elevado consumo de leite e derivados. Para o almoo, a aplicao do FCM na interao dos nutrientes, notou-se que a ingesto de vitamina C foi determinante na classificao dos grupos. No jantar, a classificao de grupos foi determinada pela quantidade de ferro heme na interao com o clcio. Na anlise de sensibilidade realizada no almoo e no jantar, duas iteraes do algoritmo determinaram a interferncia total do clcio na biodisponibilidade do ferro.
Resumo:
O psiquiatra suo Carl Gustav Jung (1875-1961) um dos principais nomes da psicologia e da psicoterapia do sculo XX. Algumas de suas maiores contribuies terico-metodolgicas so as idias de realidade psquica, complexo, arqutipo (inconsciente coletivo), processo de individuao, mtodo dialtico, mtodo construtivo e imaginao ativa. A psicologia analtica de Jung, ao longo de sua formao, foi influenciada por diversas disciplinas, dentre elas a etnologia (cincias sociais). Este trabalho buscou dar continuidade a este processo de construo epistmica, mediante exame das concepes de Jung por intermdio da teoria do ator-rede (TAR), uma importante corrente da sociologia contempornea. Pretendeu-se tambm saber se a psicologia analtica se mantm atual ou se j uma teoria e prtica clnica anacrnicas. O principal autor relacionado TAR a quem se recorreu neste trabalho foi o socilogo francs Bruno Latour. De sua perspectiva, o acordo moderno, disjuntor de Natureza e Cultura, insuficiente para explicar a complicao inerente s entidades que compem a realidade. Para escapar das armadilhas conceptuais da modernidade, Latour opera com constructos tais como coletivo (social), ator-rede, proposio, vnculo e plasma. Alm do pensamento de Latour, este trabalho valeu-se das idias sociolgicas de Gabriel Tarde e da influenciologia etnopsicanaltica de Tobie Nathan, aproveitando-se da afinidade terica que compartilham com Latour. Nathan, por desenvolver uma prtica em psicoterapia, permitiu propor psicologia clnica de Jung determinadas questes que o enfoque mais estritamente sociolgico de Latour no possibilitava. Uma vez expostas as concepes de Latour, Tarde e Nathan, apresentaram-se os elementos da psicologia analtica com os quais se esperava que elas fossem compatveis. Concluiu-se que, apesar das diferenas, muitas aproximaes so plausveis entre psicologia analtica e TAR. Constatou-se que a concepo de Jung de um psiquismo multifacetado, em devir, cujos componentes se relacionam de diferentes maneiras, comparvel noo de ator-rede trabalhada por Latour e monadologia de Tarde. Verificou-se tambm que a abordagem pragmtica e construtiva identificada na psicoterapia junguiana em muitos aspectos anloga prtica da etnopsicanlise. Assim, foi possvel afirmar que a TAR e a psicologia analtica podem formar aliana.
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(VTE)(0001)-LiAlO2X(10501100)-LiAlO2[100]VTEGaN-LiAlO2(100)Al2O3(0001)
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ZnO0001ZnOSEMXRDZnOc0004FWHM18ZnO
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ZnO thin films were grown on single-crystal gamma-LiAlO2 (LAO) and sapphire (0001) substrate by pulsed laser deposition (PLD). The structural, optical and electrical properties of ZnO films were investigated. The results show that LAO is more suitable for fabricating ZnO films than sapphire substrate and the highest-quality ZnO film was attained on LAO at the substrate temperature of 550 degrees C. However, when the substrate temperature rises to 700 degrees C, lithium would diffuse from the substrate (LAO) into ZnO film which makes ZnO film on LAO becomes polycrystalline without preferred orientation, the stress in ZnO film increases dominantly and the resistivity of the film decreases exponentially. (c) 2005 Elsevier B.V. All rights reserved.
Resumo:
VTE0001-LiAlO2-LiAlO2-LiAlO2-LiAlO2-LiAlO2
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111CZnOZnOXC900ZnO600
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Colorectal cancer is one of the most frequent neoplasms and an important cause of mortality in the developed world. Mendelian syndromes account for about 5% of the total burden of CRC, being Lynch syndrome and familial adenomatous polyposis the most common forms. Lynch syndrome tumors develop mainly as a consequence of defective DNA mismatch repair associated with germline mutations in MLH1, MSH2, MSH6 and PMS2. A significant proportion of variants identified by screening these genes correspond to missense or noncoding changes without a clear pathogenic consequence, and they are designated as "variants of uncertain significance'', being the c.1852_1853delinsGC (p.K618A) variant in the MLH1 gene a clear example. The implication of this variant as a low-penetrance risk variant for CRC was assessed in the present study by performing a case-control study within a large cohort from the COGENT consortium-COST Action BM1206 including 18,723 individuals (8,055 colorectal cancer cases and 10,668 controls) and a case-only genotype-phenotype correlation with several clinical and pathological characteristics restricted to the Epicolon cohort. Our results showed no involvement of this variant as a low-penetrance variant for colorectal cancer genetic susceptibility and no association with any clinical and pathological characteristics including family history for this neoplasm or Lynch syndrome.
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In this work, alpha-Al2O3:C, a highly sensitive thermoluminescence dosimetry crystal, was grown by the EFG method in which a graphite heating unit and shield acted as the carbon source during the growth process. The optical, luminescent properties and dosimetric characteristics of the crystal were investigated. The as-grown crystal shows a single glow peak at 536 K, which is associated with Cr3+ ions. After annealing in H-2 at 1673 K for 80 h, the crystal shows a single glow peak at 460 K and a blue emission band at 415 nm. The thermoluminescent response of the annealed crystal shows linear-sublinear-saturation characteristics in the dose range from 5 x 10(-6) to 100 Gy.
Resumo:
In this work, an alpha-Al2O3:C crystal with highly sensitive thermoluminescence was directly grown by the temperature gradient technique (TGT) using Al2O3 and graphite powders as raw materials. The optical and luminescent properties and the dosimetric characteristics of the crystal were investigated. An as-grown alpha-Al2O3:C crystal shows a single glow peak at 462 K and a blue emission peak at 415 nm. The thermoluminescence (TL) response of the crystal shows a linear-sublinear-saturation characteristic. In the dose range from 5 x 10(-6) to 10Gy, the alpha-Al2O3:C crystal shows excellent linearity, and saturation was observed at about 30Gy. The sensitivity of the crystal decreases as the heating rate increases. (c) 2008 Elsevier B.V. All rights reserved.
Resumo:
alpha-Al2O3:C crystal shows excellent thermoluminescence (TL) and optically stimulated luminescence (OSL) properties but the real role carbon plays in this crystal is still not clearly understood so far. In this work, alpha-Al2O3:C crystal doping with different amounts of carbon were grown by the temperature gradient technique, and TL and OSL properties of as-grown crystals were investigated. Additionally, a mechanism was proposed to explain the role of carbon in forming the TL and OSL properties of alpha-Al2O3:C. TL and OSL intensities of as-grown crystals increase with the increasing amount of carbon doping in the crystal, but no shift is found in the glow peak location at 465 K. As the amount of carbon doping in the crystals decreases, OSL decay rate becomes faster. With the increase in heating rate, the integral TL response of as-grown crystals decreases and glow peak shifts to higher temperatures. TL response decrease rate increases with the increasing amount of carbon doping in the crystals. All the TL and OSL response curves of as-grown crystals show linear-sublinear-saturation characteristic, and OSL dose response exhibits higher sensitivity and wider linear dose range than that of TL. The crystal doping with 5000 ppm carbon shows the best dosimetric properties. Carbon plays the role of a dopant in alpha-Al2O3:C crystal and four-valent carbon anions replace the two-valent anions of oxygen during the crystal growth process, and large amounts of oxygen vacancies were formed, which corresponds to the high absorption coefficient of F and F+ centers in the crystals.
Resumo:
-Al2O3,-Al2O3:C,RisTL/OSL-DA-15.-Al2O3:C462K,410nm.,,462K.-Al2O3:C,,,.510-610Gy,-Al2O3:C,30Gy;510-660Gy,100Gy.,.
Resumo:
We report on a diode-pumped, cryogenic and room temperature operation of a Tm,Ho:YAlO3 (c-cut) laser. In a temperature of 77 K, an optical-optical conversion efficiency of 27% and a slope efficiency of 29% were achieved with the maximum continuous-wave (CW) output power of 5.0 W at 2.13 mu m. Acousto-optic switched operation was performed at pulse repetition frequency (PRF) from 1 kHz to 10 kHz, the highest pulse energy of 3.3 mJ in a pulse duration of 40 ns was obtained. In room temperature (RT), the maximum CW power of Tm,Ho:YAlO3 laser was 160 mW with a slope efficiency of 11% corresponding to the absorbed pump power. (C) 2008 Optical Society of America.
