Thermodynamic anomalies in ultracold quantum gases

Although well-researched as a prototype Hamiltonian for strongly interacting quantum systems, the Bose-Hubbard model has not so far been explored as a fluid system with waterlike anomalies. Water, the substance of life, is known for its myriad of anomalous properties, whose origins are still subject of intense debates. In order to provide a different insight into this problem, we show how its density anomaly can be reproduced using a quantum simulator. In particular, we demonstrate that the Bose-Hubbard model, such paradigm system in quantum mechanics, exhibits an increase in density with temperature at fixed pressure in the regular fluid regime and in the superfluid phase. We propose that the mechanism underlying the anomalies is related to zero point entropies and ground state phase transitions. A connection with the typical experimental scales and setups including confinement effects is also addressed. In this scenario, such finding opens a new pathway for theoretical and experimental studies of waterlike anomalies in the area of ultracold quantum gases. We also discuss in detail the occurrence of anomalous double peaks in their specific heat dependence on temperature. This feature, usually associated with a high geometrical frustration, can also be a consequence of a purely energetic competition. By employing self-energy functional calculations combined to finite-temperature perturbation theory, we propose a mechanism based on ground-state degeneracies expressed as residual entropies. A general decomposition of the specific heat in terms of all possible transitions between the system’s eingenvalues provides an insight on the nature of each maximum. Furthermore, we address how the model parameters modify the structure of these peaks based on its spectral properties and atom-atom correlation function. Regarding the theoretical foundations of the methods employed, we address a deep analysis of the Legendre transformation, and how it can be conceived as extremum principle. We discuss the geometrical implications in a general framework, which includes the techniques explored throughout this thesi

Growth, Poverty and Employment in Brazil, Chile and Mexico

Insufficient labour income and limited access to employment are critical problems that policy makers must address when designing development strategies in Latin American countries. The persistence of the high incidence of poverty and inequality can be explained largely by the poor performance of labour markets. This Working Paper uses household survey data for Chile, Brazil and Mexico, from the early 1990s to the early 2000s, to examine the link between the growth of labour income, employment creation and the distributional impact of these factors. Through a simple decomposition of the sources of household labour income into earnings per worker and employment per population, the paper evaluates the role of economic, social and demographic factors in contributing to income changes. This decomposition shows that earnings per worker were the single most important determinant of the change in household labour income per capita. The change in earnings had the largest impact on household labour income in five of the eight country periods considered. Changes in the employment to population rate did play a role in determining labour income, but was much less important. Further decompositions show that despite favourable declines in dependency rates, the unfavourable trends of an almost ubiquitous rise of unemployment rates and, at times, the decline of participation rates dampened the contribution of employment to household labour income. The paper also decomposes labour income per capita into 20 equally sized partitions in order to evaluate its distributional pattern. A simple evaluation rule is used to validate whether changes can be considered pro-poor. Of the eight country periods analysed, only three exhibited income changes favouring the poor: Brazil in 1996-2004, Mexico in 1994-1996 and Mexico in 2000-2004. But in two of these, the pro-poor change occurred during economic contractions. In the remaining five country cases, the increase of labour income was associated with a distributional pattern that did not favour the poor. Thus, there was only one period in which labour income not only increased but was also pro-poor. But even in this case, the distribution did not favour the extremely poor. The alternating pattern of change in favour of and against the poor is explained mostly by the change in their earnings. The pattern of change in employment rarely favoured them. But when it did, usually during economic downturns, the rising participation rate of poor workers was the main reason.Earnings, Employment, Labour Markets, Pro-Poor Growth

Conditional Cash Transfers in Brazil, Chile and Mexico: Impacts upon Inequality

This Working Paper decomposes changes in the Gini coefficient in order to investigate whether Conditional Cash Transfers (CCT) have had an inequality reducing effect in three Latin American countries: Brazil, Mexico and Chile. Its technique is the decomposition of the Gini coefficient by factor components. Its main finding is that CCT programmes helped reduce inequality between the mid-1990s and roughly the mid-2000s. The share of total income represented by the CCTs has been very small: about 0.5 per cent in Mexico and Brazil and a very small 0.01 per cent in Chile. But since their targeting has been outstanding, their equalizing impact was responsible for about 21 per cent of the fall in both the Brazilian and the Mexican Gini index, each of which fell by approximately 2.7 points during the period that this paper reviewed. In Chile the effect was responsible for a 15 per cent reduction in inequality, although the total reduction in inequality was very modest: a mere 0.1 Gini point. The difference was due to the small size of the Chilean programme relative to the larger Mexican and Brazilian programmes.Distribution, Conditional Cash Transfers, Brazil, Chile, Mexico

Coexistência de fases, criticalidade e solubilidade em mistura binárias

Fundando-se em argumentos de equilíbrio e estabilidade termodinâmica, a solubilidade de soluto em um solvente é definida pelo limiar de existência da mistura como sistema homogêneo. De fato, entende-se tal grandeza sobre a coexistência de fases. A noção de solubilidade apresentada é desenvolvida através de modelos simples, que incluem resultados na rede bem como a extensão do modelo de van der Waals ao caso de duas componentes. Desta extrai-se uma condição genérica à observação de mínimos na solubilidade incidente sobre a topologia de seu diagrama de fases e de evidente correspondência física.Concerning the equilibrium and stability in thermodynamics, the solubility of solute in a solvent is defined as the threshold of the mixture existing as a homogeneous system. Indeed, such quantity meets its meaning when understood on the coexistence surface. The idea of solubility presented is developed following the discussion of simple models, including results on the lattice as well as the van der Waals model extended to include two components. From these results we extract a general condition which connects the occurence of a minimum in solubility to the topological structure of the phase diagram

Estudo do Comportamento Estrutural da Ponte Militar Mabey&Johnson : Soluções para Aumentar a Capacidade de Carga e Comprimento de Montagem

As pontes logísticas militares são, desde a década 30 do século XX, indispensáveis em vários teatros de operações possibilitando transpor obstáculos com elevada rapidez, tais como cursos de água. Procurando aumentar o comprimento de vão bem como a capacidade de carga da mais recente ponte logística militar em Portugal, Ponte Mabey, elaboraram-se vários modelos numéricos de elementos finitos, aferidos com outros estudos, os quais pretenderam avaliar a capacidade de carga da ponte para uma configuração de montagem de um tabuleiro contínuo com dois vãos longos de 57.91 m. Tendo em consideração as limitações de capacidade de carga encontradas para a configuração estudada, tanto para tráfego de natureza militar como civil, avaliaram-se várias possíveis soluções de reforço, desde a alteração geométrica da ponte a alterações de secção e adição de novos elementos. Uma vez definida uma solução possível de ser utilizada, realizou-se o estudo da montagem da ponte por lançamento incremental, a partir da solução proposta pelo fornecedor e um lançamento que foi possível acompanhar e estudar, na Companhia de Pontes do Regimento de Engenharia n.º 1, que serviu como referência no estudo do lançamento da ponte.Exército Português; Academia Militar; CINAMI

Ensaio preliminar da qualidade da água da lagoa de Ibiraquera (SC)

The Ibiraquera Lagoon is an important lagoon system on the coast of Santa Catarina, between the cities of Imbituba and Garopaba and is used for various purposes by residents and tourists. Due to the inadequate occupation process at its edges, the lagoon has been suffering a series of environmental impacts. Thus, a study aimed to carry out a preliminary sampling of the water quality of Ibiraquera in July 2019, considering physical-chemical and bacteriological parameters, their correlations and whether they are in accordance with the legislation. Collections were made at 14 points in the lagoon perimeter where the parameters pH, Temperature, Turbidity, Electrical Conductivity, Salinity, Dissolved Oxygen, Ammonical Nitrogen, Nitrite, Nitrate, Total Phosphorus, Phosphate, Sulfide, Silica, Detergents, Total Coliforms were analyzed and E. coli in the laboratory. Values ​​above the maximum allowed by CONAMA Resolutions 357/2005 and CONAMA 274/2000 for pH, Fecal Coliforms, E. coli, Nitrate, Sulfide, Detergent, Phosphate were found. Significant correlations were found between Temperature and pH, salinity and conductivity, O. D. and Silica, Nitrite and Detergent, Nitrite and Silica, Total Coliforms and E. coli. Further studies are suggested, encompassing climatic variables and verifying the behavior of the parameters seasonally.A Lagoa de Ibiraquera situada se constitui de um importante sistema lagunar no litoral de Santa Catarina, entre as cidades de Imbituba e Garopaba e é utilizada para vários fins por moradores e turistas. Devido ao processo de ocupação inadequado em suas bordas, a laguna vem sofrendo uma série de impactos ambientais. Assim, estudo visou realizar uma amostragem preliminar da qualidade de água de Ibiraquera no mês de julho de 2019, considerando parâmetros físico-químicos e bacteriológicos, suas correlações e se estão de acordo com a legislação. Realizaram-se coletas em 14 pontos no perímetro lagunar onde analisaram-se os parâmetros pH, Temperatura, Turbidez, Condutividade Elétrica, Salinidade, Oxigênio Dissolvido, Nitrogênio Amonical, Nitrito, Nitrato, Fósforo Total, Fosfato, Sulfeto, Sílica, Detergentes, Coliformes Totais e E. coli em laboratório. Constataram-se valores acimas do máximo permitido pelas Resoluções CONAMA 357/2005 e CONAMA 274/2000 para pH, Coliformes Fecais, E. coli, Nitrato, Sulfeto, Detergente, Fosfato. Encontraram-se correlações significativas entre Temperatura e pH, salinidade e condutividade, O. D. e Sílica, Nitrito e Detergente, Nitrito e Sílica, Coliformes Totais e E. coli.. Para Coliformes Totais, apenas um ponto se apresenteu abaixo do VMP pela legislação. Sugerem-se novos estudos englobando variáveis climáticas e verificando o corportamento dos parâmetros sazonalmente

Brand equity no agronegócio: Percepção do consumidor brasileiro de carne suína

Even sectors that usually offer similar products, such as agribusiness, can develop brand strategies that are potentially capable of promoting a greater perceived value in the eyes of consumers. This paper discusses how the origin of the product, perceptions, and attitudes of Brazilian high-income consumers concerning food production processes, and brand equity assigned by consumers to certification processes affect the formation of brand equity in agricultural commodities

Conditional cash transfers in Brazil, Chile and Mexico: impacts upon inequality

We decompose changes in the Gini coefficient to investigate whether the Conditional Cash Tranfers (CCT) have had an inequality reducing effect in three Latin American countries: Brazil, Mexico and Chile. We conclude that CCT programs helped reducing inequality between the mid-1990s and the mid-2000s. The share of total income represented by the CCTs is very small, less than 1%. But as their targeting is outstanding, the equalising impact of CCTs was responsible for about 21% of the fall in Brazilian and Mexican inequality figures In Chile the effect was responsible for around 15% of the reduction.Conditional Cash Transfers, CCT, inequality, Gini decomposition