Atomic structure calculations in lanthanide ions relevant to kilonovae

Tese de mestrado, Física (Física Nuclear e Partículas) Universidade de Lisboa, Faculdade de Ciências, 2021The present dissertation concerns atomic structure calculations for lanthanide and actinide ions that are significant to kilonovae modeling of the ejecta spectra. In particular, calculations for Nd III and U III, two representative rare-earth ions, were achieved. Therefore, in this work we try to bridge the gap created by the lack of atomic structure calculations f-block ions available in the literature, while also providing valuable insight for future calculations. We concentrated on level energies and oscillator strength calculations for electric dipole transitions (E1) since these are the most critical atomic parameters for simulating the flux of kilonovae in Local Thermodinamical Equilibrium (LTE). We mainly use the publicly accessible Flexible Atomic Code (FAC) for the computations, which employs a Relativistic Configuration Interaction (RCI) method. Not only that, but we compare our results to those obtained using a Multi-configuration Dirac-Fock (MCDF) method as well as to available computational and experimental data. We demonstrated that discrepancies in the opacity spectra of Nd III across various calculations are higher at the ultraviolet and visible wavelengths. At longer wavelengths the sensitivity of the opacity with the accuracy of the calculations seems to decrease. Additionally, we showed the opacity of U III to be about an order of magnitude higher than the opacity of Nd III due to a higher density of levels of the actinide. In general, we anticipate this feature of the spectrum to extend for more lanthanide-actinide pairs and, therefore, that the opacity of actinides to have a measurable impact in the luminosity of kilonovae

Financing exponential growth at H3

H3 is a fast-food chain that introduced the concept of gourmet hamburgers in the Portuguese market. This case-study illustrates its financing strategy that supported an exponential growth represented by opening 33 restaurants within approximately 3 years of its inception. H3 is now faced with the challenge of structuring its foreign ventures and change its financial approach. The main covered topics are the options an entrepreneur has for financing a new venture and how it evolves along the life cycle and different business approaches, namely franchising. It aims to be used as a learning tool in courses such as entrepreneurial finance

Nonlinearities and synchronization of business cycles : a novel approach

Mestrado em EconomiaEsta dissertação estuda os padrões de sincronização de ciclos económicos numa amostra composta por 18 países desenvolvidos e a Zona Euro ao longo do período 1970:1-2008:1. Para realizar este estudo, propomos um novo modelo de componentes não observáveis multivariado com markov-switching e interdependência de estados variável no tempo, no qual a sincronização é modelizada como uma componente comum variável no tempo entre os ciclos económicos. Para estimar o modelo, desenvolvemos um filtro de Kalman adequado, que permite a projecção das componentes não observáveis e a estimação dos hiperparâmetros por máxima verosimilhança. Propomos também um novo fullsample smoother para recalcular as componentes não observáveis do modelo com base em toda a informação amostral. Usamos este modelo para testar 3 hipóteses: se a criação da União Monetária Europeia promoveu um aumento na sincronização dos ciclos económicos entre os seus membros; se a integração promoveu uma mudança na filiação cíclica com o ciclo económico dos EUA; se existe o surgimento de um ciclo económico agregado da Zona Euro. Os resultados mostram que a sincronização cíclica dos países da Zona Euro com a Zona Euro agregada foi superior à dos restantes países. No entanto, para a maioria dos países da Zona Euro, a sincronização com a Zona agregada aumentou até ao início da década de 90, e diminuiu a partir desse período. Apesar de existir um ligeiro aumento na sincronização com a Zona Euro agregada para algumas economias participantes em torno do momento da introdução da moeda única, não somos capazes de detectar um “efeito Euro” claro. Por outro lado, para a maioria das economias, a introdução da moeda única é coincidente com uma redução na sincronização com o ciclo dos EUA. Finalmente, não encontramos evidência do surgimento de um ciclo económico agregado da Zona Euro. ABSTRACT: This dissertation studies the patterns of business cycle synchronization across a sample of 18 developed countries and the aggregate Euro Area over the period 1970:1-2008:1. To perform this study, we propose a novel multivariate unobservedcomponents model with markov-switching and time-varying state interdependence, in which synchronization is modelled as a time-varying common component between the business cycles. To estimate the model, we develop an adequate Kalman filter, which allows the projection of the unobserved components and the estimation of the hyperparameters by maximum likelihood. We also propose a new full-sample smoother to recompute the unobserved components of the model based on all in-sample information. We use this model to test 3 hypothesis: whether the creation of the European Monetary Union promoted an increase in business cycle synchronization among its members; whether the integration has promoted a change in the cyclical affiliation with the US business cycle; and whether there is an emergence of an aggregate Euro Area business cycle. The results show that synchronization between the Euro Area countries with the aggregate Euro Area has been higher than for the remaining countries. Nevertheless, for the majority of the Euro Area countries, synchronization with the aggregate Area increased until the beginning of the 1990s, and dropped from that period onwards. Moreover, despite the existence of a slight increase in synchronization with the aggregate Euro Area for some participant economies around the timing of the introduction of the common currency, we are not able to uncover a clear “Euro effect”. On the other hand, for most of the economies, the introduction of the common currency is shown to be coincident with a drop in synchronization with the US business cycle. Finally, we do not find evidence of the emergence of an aggregate Euro-Area business cycle

Dcmc as a promising alternative to bentonite in white wine stabilization. Impact on protein stability and wine aromatic fraction

Funding Information: Funding: This research was funded by Associate Laboratory for Green Chemistry—LAQV, which is financed by national funds from FCT/MCTES [UID/QUI/50006/2020] and the project [UIDB/05183/2020], CENSE (Center for Environmental and Sustainability Research), which is financed by national funds from FCT/MCTES (UID/AMB/04085/2020), and LEAF, which is financed by national funds from FCT/MCTES (LEAF UID/AGR/04129/2020). This research was also anchored by the RESOLUTION LAB, an infrastructure at NOVA School of Science and Technology. DG was financed by a PhD grant: DFA/BD/5529/2020.Protein haze in white wine is one of the most common non-microbial defects of commercial wines, with bentonite being the main solution utilized by the winemaking industry to tackle this problem. Bentonite presents some serious disadvantages, and several alternatives have been pro-posed. Here, an alternative based on a new cellulose derivative (dicarboxymethyl cellulose, DCMC) is proposed. To determine the efficiency of DCMC as a bentonite alternative, three monovarietal wines were characterized, and their protein instability and content determined by a heat stability test (HST) and the Bradford method, respectively. The wines were treated with DCMC to achieve stable wines, as shown by the HST, and the efficacy of the treatments was assessed by determining, before and after treatment, the wine content in protein, phenolic compounds, sodium, calcium, and volatile organic compounds (VOCs) as well as the wine pH. DCMC applied at dosages such as those commonly employed for bentonite was able to reduce the protein content in all tested wines and to stabilize all but the Moscatel de Setúbal varietal wine. In general, DCMC was shown to induce lower changes in the wine pH and phenolic content than bentonite, reducing the wine calcium content. Regarding which VOCs are concerned, DCMC produced a general impact similar to that of bentonite, with differences depending on wine variety. The results obtained suggest that DCMC can be a sustainable alternative to bentonite in protein white wine stabilization.publishersversionpublishe

Wearable textile elongation sensor

This work shows a developed wearable elongation sensor based on an optical fiber. The presented approach to sew a fiber optic into a lycra textile enables the modulation of light amplitude in respect to textile strain. This apparatus in combination with small-size instrumentation enables the development of a wearable textile garment capable of monitoring and acquiring strain data, and send it wirelessly to a base station. The light amplitude increases with the increment of textile strain. The output voltage remains stable over time for the resting and maximum textile strain position

GENETICALLY MODIFIED ORGANISMS AND THEIR IMPACT ON INTERNATIONAL AGRICULTURAL TRADE: A CASE STUDY ON SOY

This paper discusses the introduction of genetically modified (GM) seeds in agriculture and their impact on the modus operandiof international trade of agricultural commodities. The central argument in this paper is that the commercial rejection by some markets, especially in the European Union, resulted in broad market share restructuring of the three largest international soy exporters: the United States, Brazil, and Argentina. These findings came as a result of trade flow analysis, taking into account the source and destination of soy in the soy trade using the quantitative Constant Market Share method. Taking into account that at the time of the study there were no legal trade barriers put up by the European Union, which was resistant to the use of Monsanto’s herbicide-tolerant soy (GTS-40-3-2), it is assumed that the effects resulting from its commercial rejection were due to demand factors and not for any official trade ban. It is concluded that technology adoption caused changes in factors that led to export growths. However, despite changes in market share, the globalization effect prevented exporters from incurring greater trade losses since they always had the option of moving their products to markets with lower levels of “hatred”.

Processamento digital de sinal em sistemas de deteção coerente

Mestrado em Engenharia Electrónica e TelecomunicaçõesNas últimas décadas, as comunicações óticas têm estado diretamente ligadas à rápida evolução dos sistemas de comunicações e caso não existissem, hoje seria difícil responder à procura incessante por largura de banda. Contudo, a sua capacidade é limitada, devido a limitações e constrangimentos associados aos equipamentos físicos e, caso não se progrida, não será possível responder adequadamente às futuras necessidades das redes de telecomunicações. Nesse sentido, é conveniente continuar a inovação para novas soluções que permitam superar estas limitações. Nesta dissertação será apresentado um estudo sobre formatos de modulação avançados e multiplexagem da informação, capazes de superar em larga escala as larguras de banda oferecidas atualmente, bem como superar o alcance físico das atuais redes, com custos mais reduzidos. Em particular será analisado o desempenho da deteção coerente como solução para as futuras redes de acesso (NGPON), onde o processamento digital de sinal possui uma importância relevante na eficiência e custo do sistema. Nesse sentido, em simulação será discutido o sistema PDM-QPSK, que se trata de uma promissora técnica de modulação para as futuras redes NGPON, e em laboratório o sistema QPSK a 1.244 Gbps.In the last decades, optical communications introduced a different concept in communications systems. If they do not exist, today would be difficult to answer the demand for bandwidth. This higher bandwidth is related to its physical characteristics, which make them overcome other media. However, its capacity is limited due to the performance of physical equipment and if we do not make progress, it will be not possible to respond to the demands for the future telecommunications networks. Thus, it is appropriate to continue innovation for new solutions to overcome these limitations. In this dissertation, a study will be presented to advanced modulation formats and multiplexing of information, able to overcome in large scale the bandwidth currently offered, as well as overcome the physical reach of existing networks with lower costs. In particular will be analyzed the performance of coherent detection as a solution to the future access networks (NGPON), where the digital signal processing has a significant impact on the efficiency and cost of the system. In this sense, in simulation will be discussed the PDM-QPSK system, that it is a promising modulation technique for future networks, and in the laboratory the QPSK system at 1.244 Gbps