Tailoring the porosity of chemically activated hydrothermal carbons: Influence of the precursor and hydrothermal carbonization temperature

Advanced porous materials with tailored porosity (extremely high development of microporosity together with a narrow micropore size distribution (MPSD)) are required in energy and environmental related applications. Lignocellulosic biomass derived HTC carbons are good precursors for the synthesis of activated carbons (ACs) via KOH chemical activation. However, more research is needed in order to tailor the microporosity for those specific applications. In the present work, the influence of the precursor and HTC temperature on the porous properties of the resulting ACs is analyzed, remarking that, regardless of the precursor, highly microporous ACs could be generated. The HTC temperature was found to be an extremely influential parameter affecting the porosity development and the MPSD of the ACs. Tuning of the MPSD of the ACs was achieved by modification of the HTC temperature. Promising preliminary results in gas storage (i.e. CO2 capture and high pressure CH4 storage) were obtained with these materials, showing the effectiveness of this synthesis strategy in converting a low value lignocellulosic biomass into a functional carbon material with high performance in gas storage applications.

Hydrothermal Carbons from Hemicellulose-Derived Aqueous Hydrolysis Products as Electrode Materials for Supercapacitors

Acid pretreatment of lignocellulosic biomass, required for bioethanol production, generates large amounts of by-products, such as lignin and hydrolyzed hemicellulose fractions, which have found so far very limited applications. In this work, we demonstrate how the recovered hemicellulose hydrolysis products can be effectively utilized as a precursor for the synthesis of functional carbon materials through hydrothermal carbonization (HTC). The morphology and chemical structure of the synthesized HTC carbons are thoroughly characterized to highlight their similarities with glucose-derived HTC carbons. Furthermore, two routes for introducing porosity within the HTC carbon structure are presented: i) silica nanoparticle hard-templating, which is shown to be a viable method for the synthesis of carbonaceous hollow spheres; and ii) KOH chemical activation. The synthesized activated carbons (ACs) show an extremely high porosity (pore volume≈1.0 cm3 g−1) mostly composed of micropores (90 % of total pore volume). Because of their favorable textural properties, the ACs are further tested as electrodes for supercapacitors, yielding very promising results (300 F g−1 at 250 mA g−1) and confirming the high suitability of KOH-activated HTC carbons derived from spruce and corncob hydrolysis products as materials for electric double layer supercapacitors.

Efeitos da microgravidade no raciocínio lógicomatemático, proposta de experimentação

O trabalho a seguir apresentado tem por objetivo procurar perceber se o nosso raciocínio se processa da mesma maneira em presença de microgravidade ou se, pelo contrário, sofre alguma alteração. A nossa questão foca-se mais especificamente num teste de matemática e, a partir da análise das diferentes variantes intervenientes na resolução do mesmo e das condições em causa (ambiente de microgravidade), inferirmos a possibilidade de o resultado do teste poder ser melhor do que quando elaborado em condições de gravidade normal.

Inference of binding affinity from neuronal receptors in humans

Tese de mestrado, Bioinformática e Biologia Computacional (Bioinformática), Universidade de Lisboa, Faculdade de Ciências, 2016

Galectina-3 : indicador de prognóstico : alvo de intervenção terapêutica?

Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2014

A relevância das medidas individualizadas : ouvimos o paciente mas captamos a história?

Individualized measures are relevant for the assessment of therapeutic results and allow patients to identify the aspects that they value the most in assessing their clinical improvement. PSYCHLOPS, as an individualized measure, invite the patient to create their own items. The items created by the patients were compared with the contents of standardized measures. A sample composed by 107 patients admitted for psychological treatment in Hospital Espírito Santo (Évora), and three institutions for drug misuse fill in the PSYCHLOPS and two standardized measures presented in a random order: CORE-OM and PHQ-9. 279 items were created in PSYCHLOPS and later recoded, by thematic analysis, in 51 subthemes. Work-related problems was the most common subtheme identified by patients as relevant to the clinical improvement assessment. From the 51 subthemes, 17 (33.3%) were not represented in CORE-OM and 43 (84.3%) were not represented in PHQ-9. The majority of our sample indicated at least one subtheme that was not represented in CORE-OM and PHQ-9. These results show us the importance of individualized measures in identifying the patients’ most value concerns, which may have implications in the therapeutic process.

Clostridium difficile: principais fatores de risco, controlo e prevenção

Dissertação para obtenção do grau de Mestre no Instituto Superior de Ciências da Saúde Egas Moniz

Consciência fonológica e métodos de ensino da leitura: que relação?

A consciência fonológica é uma identificação das particularidades fonológicas e das unidades que compõem a fala, ou seja, diz respeito à consciência dos sons que constituem as palavras que ouvimos e falamos. É a capacidade que permite a identificação de rimas, palavras que começam e terminam com o mesmo som e fonemas que são manipulados para criação de novas palavras. Os métodos de ensino da leitura são as diferentes maneiras que existem para ensinar os alunos a ler e a escrever, cada um deles tem as suas caraterísticas e especificações. O presente estudo visa compreender qual a relação existente entre as competências fonológicas e os métodos de ensino da leitura, sendo necessário entender primeiro, em que consiste a aprendizagem da leitura, quais são as competências essenciais para adquirir esta aprendizagem e como se desenvolve a consciência fonológica. Para compreender esta relação, foi construído um instrumento com base nas Metas Curriculares para o 1º ciclo e aplicada em alunos do 1º ano de escolaridade. Participaram nesta prova 9 alunos de 3 escolas, que por sua vez, ensinam a ler através de métodos diferentes. Relativamente ao desempenho dos alunos na prova, podemos verificar que os alunos do método sintético, boquinhas, demonstraram ser mais eficazes nas tarefas de consciência fonológica. Em seguida os alunos do método misto, pois este tem semelhanças com o método anterior e por último os alunos do método Ave Maria .

(Table A1) Annual biomass of plants and animals recorded on Bylot Island between 1993-2009

Determining the manner in which food webs will respond to environmental changes is difficult because the relative importance of top-down vs. bottom-up forces in controlling ecosystems is still debated. This is especially true in the Arctic tundra where, despite relatively simple food webs, it is still unclear which forces dominate in this ecosystem. Our primary goal was to assess the extent to which a tundra food web was dominated by plant-herbivore or predator--rey interactions. Based on a 17-year (1993-2009) study of terrestrial wildlife on Bylot Island, Nunavut, Canada, we developed trophic mass balance models to address this question. Snow Geese were the dominant herbivores in this ecosystem, followed by two sympatric lemming species (brown and collared lemmings). Arctic foxes, weasels, and several species of birds of prey were the dominant predators. Results of our trophic models encompassing 19 functional groups showed that <10% of the annual primary production was consumed by herbivores in most years despite the presence of a large Snow Goose colony, but that 20-100% of the annual herbivore production was consumed by predators. The impact of herbivores on vegetation has also weakened over time, probably due to an increase in primary production. The impact of predators was highest on lemmings, intermediate on passerines, and lowest on geese and shorebirds, but it varied with lemming abundance. Predation of collared lemmings exceeded production in most years and may explain why this species remained at low density. In contrast, the predation rate on brown lemmings varied with prey density and may have contributed to the high-amplitude, periodic fluctuations in the abundance of this species. Our analysis provided little evidence that herbivores are limited by primary production on Bylot Island. In contrast, we measured strong predator-prey interactions, which supports the hypothesis that this food web is primarily controlled by top-down forces. The presence of allochthonous resources subsidizing top predators and the absence of large herbivores may partly explain the predominant role of predation in this low-productivity ecosystem.

Vida que canta.

Poems.

Ensayos literarios : narraciones /

Cover title : Horas de descanso.

Breviario galante /

Mode of access: Internet.

Migration and development : the case of Puerto Rico /

Cover title.