Kinetics and Mechanism of Metal Nanoparticle Growth via Optical Extinction Spectroscopy and Computational Modeling: The Curious Case of Colloidal Gold

An overarching computational framework unifying several optical theories to describe the temporal evolution of gold nanoparticles (GNPs) during a seeded growth process is presented. To achieve this, we used the inexpensive and widely available optical extinction spectroscopy, to obtain quantitative kinetic data. In situ spectra collected over a wide set of experimental conditions were regressed using the physical model, calculating light extinction by ensembles of GNPs during the growth process. This model provides temporal information on the size, shape, and concentration of the particles and any electromagnetic interactions between them. Consequently, we were able to describe the mechanism of GNP growth and divide the process into distinct genesis periods. We provide explanations for several longstanding mysteries, for example, the phenomena responsible for the purple-greyish hue during the early stages of GNP growth, the complex interactions between nucleation, growth, and aggregation events, and a clear distinction between agglomeration and electromagnetic interactions. The presented theoretical formalism has been developed in a generic fashion so that it can readily be adapted to other nanoparticulate formation scenarios such as the genesis of various metal nanoparticles.Comment: Main text and supplementary information (accompanying MATLAB codes available on the journal webpage

Liver transplantation and severe acute alcoholic hepatitis: an ethical consideration.

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Análise sísmica e modelação de edifícios de betão armado de acordo com a regulamentação portuguesa e italiana

Dissertação de natureza científica para obtenção do grau de Mestre em Engenharia Civil na Área de Especialização de EstruturasCom a entrada em vigor dos Eurocódigos Estruturais, a análise e dimensionamento de estruturas, nos diversos Estados-Membros, seguem os mesmos princípios normativos, divergindo apenas de acordo com as especificidades de cada anexo nacional. No âmbito deste trabalho apresenta-se uma abordagem que envolve a análise sísmica e modelação de edifícios de betão armado em Portugal e Itália, procurando evidenciar-se as especificidades dos anexos nacionais destes dois Estados-Membros. Neste contexto, numa primeira fase do trabalho são introduzidos os principais conceitos associados ao fenómeno sísmico, nomeadamente a tipologia de ondas sísmicas, as placas tectónicas e a caracterização da sismicidade; são também abordados os impactos dos sismos em meio urbano, subdividindo-os em danos diretos e indiretos e os seus efeitos globais e locais em estruturas de betão armado. Numa fase subsequente são então descritos os aspetos mais relevantes sobre a aplicação da regulamentação sísmica utilizada para a conceção de edifícios de betão armado em Portugal e em Itália, tendo por referência os Eurocódigos e o seu enquadramento no que se refere à utilização dos respetivos anexos nacionais. Para demonstrar os principais aspetos expostos anteriormente, é desenvolvido o modelo da estrutura de um edifício, utilizando o software de cálculo SAP 2000, no qual são introduzidas todas as características estruturais e geométricas do edifício, incluindo as ações a que este se encontra sujeito. Com base no modelo criado apresenta-se uma análise estrutural utilizando os métodos de análise apropriados e comparando os resultados obtidos entre a ação sísmica portuguesa e a ação sísmica italiana.With the entry into force of the Structural Eurocodes, the analysis and design of structures, in several Member States, follows the same normative principles, differing only according to the specificities of each national annex. In the scope of this work, an approach involving the seismic analysis and modelling of reinforced concrete buildings in Portugal and Italy is presented, trying to highlight the specificities of the national annexes of these two Member States. In this context, the first phase of the work introduces the main concepts associated to seismic phenomena, namely the typology of seismic waves, tectonic plates, and seismicity characterization; the impacts of earthquakes in urban environments are also addressed, subdividing them into direct and indirect damages and their global and local effects on reinforced concrete structures. In a subsequent stage, the most relevant aspects about the application of the seismic regulations used in the design of reinforced concrete buildings in Portugal and in Italy are then described, with reference to the Eurocodes and their framework regarding the use of the respective national annexes. In order to demonstrate the main aspects exposed above, a building structural model is developed, using the calculation software SAP 2000, in which all structural and geometric characteristics of the building are introduced, including the actions to which it is subjected. Based on the model created, a structural analysis is presented using the appropriate analysis methods and by comparing the results obtained respectively with the Italian seismic action and the Portuguese seismic action.info:eu-repo/semantics/publishedVersio

Querellas políticas en torno al Conde de Oropesa en las postrimerías del reinado de Carlos II

Durant les dernières années du règne de Charles II, les problèmes du gouvernement de la monarchie hispanique – qui perdait peu à peu de sa puissance et de sa force politique – ont connu une notable aggravation essentiellement due à la crise de succession au trône marquant la fin de la dynastie des Habsbourg. Dans ce contexte, l’éminente figure du Comte d’Oropesa se trouve particulièrement impliquée du fait de ses hautes charges ministérielles. Mais, au-delà du Comte lui-même, au-delà des querelles, des invectives, des conflits, au-delà des coups bas et des accusations de toute sorte, c’est tout un système qui se trouve alors condamné à travers une rhétorique cinglante où les grands, leurs ambitions et leurs spéculations semblent s’effondrer parallèlement à la monarchie.En las postrimerías del Reinado de Carlos II, los problemas del gobierno de la monarquía hispánica, que perdía poco a poco su poder y su fuerza política, se vieron acrecentados por la crisis de la sucesión al trono y el final de la dinastía de los Habsburgo. En este contexto la figura del Conde de Oropesa se encuentra particularmente afectada a causa de sus altos cargos ministeriales. Pero más allá de Oropesa, de las querellas, las invectivas, las críticas, los conflictos, los golpes bajos y las acusaciones, es todo un sistema que se condena a través una retórica mordaz y punzante, en donde los grandes, sus ambiciones y sus especulaciones parecen desmoronarse a la par de la monarquía.During the last few years of the reign of Charles II, the troubles of the government of the Spanish monarchy, which was gradually losing power and political influence, became notably more serious as a result, essentially, of the succession crisis over the throne that marked the end of the Habsburg dynasty. In this context, the distinguished figure of the Count of Oropesa was particularly involved because of the high level of his ministry responsibilities. Yet, beyond the Count himself, beyond the quarrels, the abuses, the conflicts, beyond the low blows, and the accusations of all sorts, an entire system was then doomed through the scathing rhetoric in which leading figures, their ambitions, and their speculations seemed to collapse alongside the monarchy