4 research outputs found
THE EFFECT OF THE INITIAL CONCENTRATION AND FLOW RATE OF STRONTIUM WASTE ON THE ADSORPTION ABILITY OF HKUST- 1 USING THE FLOW METHOD
No full textStrontium-90 is a nuclear fission product with a half-life of 28.79 years (<30 years). Strontium is highly dangerous if it enters the body because it emits beta rays and accumulates in the bones, particularly the spine. Therefore, it is necessary to separate strontium from the solution, and one way to do this is through adsorption. HKUST-1, a porous crystalline material, shows great potential as an efficient adsorbent for heavy metal uptake. This research investigated the adsorption capability of HKUST-1 for radioactive waste.
The adsorption process was carried out using a column system, which is commonly used in industrial applications with a top-to-bottom flow. The concentration of Sr(NO3)2 liquid waste was varied at 25, 30, and 40 mg/L, and there were also variations in the waste flow rate at 1, 3, and 5 mL/min. Atomic absorption spectroscopy (AAS) testing was performed to analyze the adsorption output.
The research results that increasing the initial concentration of the waste led to an increase in the adsorption capacity, as well as the greater the waste flow rate, the higher the adsorption capacity. The optimum value were obtained at an initial concentration of 40 mg/L and a flow rate of 5 mL/min
Fernando Henrique Cardoso e o pensamento político brasileiro
No full textTese (doutorado) - Universidade Federal de Santa Catarina, Centro de Filosofia e Ciências Humanas, Programa de Pós-Graduação em Sociologia Política, Florianópolis, 2015.A construção do legado de Fernando Henrique Cardoso tem transcorrido a partir do signo de rupturas e dicotomias estruturantes, características que se articulam em torno da ideia da transição da atividade intelectual para a atividade política, num processo que reforça traços marcantes da imaginação política brasileira. Partindo da crítica dessa visão, este trabalho investiga o que o processo de formação do legado do autor como levado a cabo até aqui tem a dizer sobre os modos pelos quais se produz e se reinventa o ?pensamento político brasileiro?, ou, em outras palavras, o que sua trajetória intelectual individual representa em relação à trajetória coletiva de pensamento designada por esta expressão. Duas teses interpretativas principais são desenvolvidas ao longo deste trabalho: a primeira, de que o fio de continuidade e de unidade entre os diversos momentos da trajetória intelectual de Cardoso, negado pelas abordagens que até o presente vão dando conta da sistematização de seu legado, pode ser reconstruído e recuperado se a ênfase da análise recair na especificidade política de seus escritos, reconstrução e recuperação que, obviamente, não se furtam a considerar possíveis inconsistências, incoerências e mudanças nas crenças ao longo de sua trajetória; e a segunda, de que tal pensamento político, sem desconsiderar outras fontes genericamente rotuladas como ?universais?, estrutura-se a partir de um diálogo seletivo, sistemático e contínuo com algumas das principais matrizes de interpretação do político no país, diálogo este que, de um lado, torna possível evidenciar a existência de uma cosmovisão a atuar como ?fio condutor? para o conjunto de seu pensamento (conferindo a ele um sentido de coerência) e, de outro, entender o impacto ressignificador desse pensamento sobre tais matrizes. O trabalho está organizado em três partes: na primeira, produz-se uma reflexão teórico-metodológica do campo do pensamento político brasileiro; na segunda, discute-se a especificidade da reflexão política do autor a partir de dois momentos distintos (o do estabelecimento e o da consolidação das suas crenças políticas); e na terceira, num exercício de tentar aproximar as duas primeiras, discute-se a especificidade da inscrição do pensamento político do autor no campo do pensamento político brasileiro a partir de duas variáveis: as filiações e as recepções.Abstract : The construction of Fernando Henrique Cardoso?s legacy has been developed based on the mark of structuring ruptures and dichotomies, characteristics that are both articulated around the idea of the transition from the intellectual to the political activity, in a process that reinforces strong features of the Brazilian political imagination. Anchored in a criticism of this view, this study investigates what the process of formation of the author?s legacy developed until the present moment reveal about the forms through which the ?Brazilian political thought? is produced and reinvented, or, in other words, what his personal intellectual trajectory represents in relation to the collective thought trajectory designated by this expression. Two main interpretative theses are tested throughout this work: the first one is that the continuity and the unity between the several moments of Cardoso?s intellectual trajectory (denied by the approaches that, until the present moment, have been systematizing his legacy) can be reconstructed and recuperated if the emphasis of the analysis lies in the political specificity of his writings - assuming that both the reconstructing and the recuperation, obviously, do not fail to consider possible inconsistencies, incoherences and changes in the beliefs of the author throughout his trajectory; and second , that such political thought , without disregarding other sources generally labeled as ?universal? , is structured from a selective, systematic and continuous dialogue with some of the main forms of interpretation of the policy in the country, this dialogue , on the one hand , makes it possible to show the existence of a worldview to act as ?common thread? for all of his thought (giving him a sense of coherence), and on the other, to understand the impact of this ressignificador thinking about such matrices. The work is organized in three parts: in the first, the field of the Brazilian political thought is theoretical and methodologically questioned; in the second part, the specificity of the author?s political reflection is discussed based on two different moments (the establishment and the consolidation of his political beliefs); and, in the third part, in an attempt of approximating the two previous parts, the specificity of the insertion of the author?s political thought in the Brazilian political thought field is discussed, which is based on two variables: the filiations and the receptions
From deterministic methods to a Bayesian approximation: towards reliable segmentation of multiple sclerosis Lesions in magnetic resonance imaging
No full textEn este trabajo, se presenta una metodología para la segmentación de lesiones de esclerosis múltiple (EM) en imágenes de resonancia magnética (IRM) que aborda las limitaciones de los modelos deterministas mediante la incorporación de la estimación de incertidumbre. Se compara una arquitectura U-Net 3D determinista con una versión modificada que emplea una aproximación bayesiana con Monte Carlo Dropout (MCD) para cuantificar la incertidumbre epistémica. Los resultados demuestran que, si bien ambos modelos alcanzan un rendimiento competitivo en términos de las métricas estándar de segmentación de imágenes médicas, la estimación de incertidumbre proporciona información valiosa sobre la fiabilidad de las predicciones, especialmente en regiones desafiantes como los bordes de las lesiones. Esto tiene el potencial de mejorar la aplicabilidad clínica de la segmentación automática al permitir a los usuarios médicos evaluar la confianza en los resultados y enfocar su revisión en áreas de mayor incertidumbre.In this work, we present a methodology for the segmentation of multiple sclerosis (MS) lesions in magnetic resonance imaging (MRI) that addresses the limitations of deterministic models by incorporating uncertainty estimation. We compare a deterministic 3D U-Net architecture with a modified version that employs a Bayesian approximation with Monte Carlo Dropout (MCD) to quantify epistemic uncertainty. The results demonstrate that while both models achieve competitive performance in terms of standard medical image segmentation metrics, the uncertainty estimation provides valuable information on the reliability of the predictions, especially in challenging regions such as lesion borders. This has the potential to improve the clinical applicability of automatic segmentation by allowing medical users to assess confidence in the results and focus their review on areas of higher uncertainty
Origins of ion energy distribution function (IEDF) in high power impulse magnetron sputtering (HIPIMS) plasma discharge
No full textThe ion energy distribution function (IEDF) in high power impulse magnetron sputtering (HIPIMS) discharges was studied by plasma sampling energy-resolved mass spectroscopy. HIPIMS of chromium (Cr), titanium (Ti) and carbon ( C) targets in argon (Ar) atmosphere was analysed. Singly and doubly charged ions of both the target and the gas were detected. Time-averaged IEDFs were measured for all detected ions at the substrate position at a distance of 150mm from the target. The effects of target current and discharge pressure on the IEDF were investigated. Measurements were done at two pressures and for three peak discharge currents. The IEDF of both the target and the gas ions was found to comprise two Maxwellian distributions. Quantitative analysis of target IEDFs at a low pressure showed that the main peak had a lower average energy with an approximate value of E-AV = 1 eV which is attributed to collisions with thermalized gas atoms and ions. The higher energy distribution has a tail extending up to 70 eV, which is assumed to originate from a Thompson distribution of sputtered metal atoms which, due to collisions, are thermalized and appear as a Maxwell distribution. The proportion of high energy IEDFs for metal ions increases monotonically as a function of Id. The effective ion temperature k(B)T, extracted from the main low energy peak, showed a weak dependence on peak current. The effective ion temperature extracted from the high energy tail showed a strong correlation with the change in Id. The IEDF at high pressure shows that a proportion of high energy IEDFs was very low and dominated by a low energy main peak. The gas IEDF at high pressure was completely thermalized. The metal-ion-to-gas-ion ratio was found to increase with Id and with the sputtering yield of the target material
