Regular black holes in f(G)f(G) gravity

In this work, we study the possibility of generalizing solutions of regular black holes with an electric charge, constructed in general relativity, for the $f(G)$ theory, where $G$ is the Gauss-Bonnet invariant. This type of solution arises due to the coupling between gravitational theory and nonlinear electrodynamics. We construct the formalism in terms of a mass function and it results in different gravitational and electromagnetic theories for which mass function. The electric field of these solutions are always regular and the strong energy condition is violated in some region inside the event horizon. For some solutions, we get an analytical form for the $f(G)$ function. Imposing the limit of some constant going to zero in the $f(G)$ function we recovered the linear case, making the general relativity a particular case.Comment: 22 pages, 25 figures.Version published in EPJ

Variação acústica das vogais orais de crianças no português europeu

Mestrado em Ciências da Fala e da AudiçãoO presente trabalho centrou-se na determinação da influência do género, da idade e do tipo de vogal na variação dos parâmetros acústicos - frequência fundamental (F0), primeiro (F1) e segundo (F2) formantes e duração - das vogais orais produzidas por crianças falantes do português europeu. A amostra foi composta por 28 crianças, divididas em quatro grupos, de acordo com o género e a idade (7 e 10 anos). Os dados foram recolhidos através da gravação de um corpus composto por pseudo-palavras com as vogais-alvo em posição tónica, inseridas numa frase-veículo. Posteriormente, procedeu-se à anotação manual através do software Praat e à extracção semi-automática dos parâmetros acústicos referidos acima. A análise estatística desses dados permitiu concluir que os parâmetros acústicos variam significativamente em função da vogal, permitindo distingui-las entre si. O primeiro e o segundo formantes são os que melhor permitem essa diferenciação: o F1 varia inversamente com o movimento vertical da língua e o F2 varia positivamente com a anteriorização do dorso da língua, para além de permitir a distinção da maioria das vogais de acordo com a altura. Também a frequência fundamental é significativamente influenciada pela altura das vogais, ou seja, os dados do presente estudo suportam a existência de uma F0 intrínseca, transversal à idade e ao género. Verificou-se, ainda, que o género implicou variações significativas no F2 e na duração, sendo os valores de ambos os parâmetros superiores nos sujeitos do sexo feminino. A idade, por sua vez, reflectiu-se apenas na duração das vogais, sendo os seus valores superiores nos sujeitos de 7 anos. Este trabalho proporcionou um primeiro contributo para o conhecimento sobre a acústica das vogais produzidas por crianças falantes do português europeu.This study focused on determining the influence of gender, age and type of vowel in the variation of the acoustic parameters – fundamental frequency (F0), first (F1) and second (F2) formants and duration – of vowels produced by children who speak european portuguese. The sample comprised 28 children, divided into four groups according to gender and age (7 and 10 years). The data were collected by recording a corpus of nonce words with the target vowels in the stressed position within a carrier sentence. Subsequently, we proceeded to make manual annotations using the Praat software and semi-automatic extraction of the acoustic parameters mentioned above. The statistical analysis of these data indicated that the acoustic parameters vary significantly depending on the vowel, allowing distinction to be made between them. The first and second formants are those which best allow this differentiation: F1 varies inversely with the vertical movement of the tongue and F2 varies positively with the moving of the tongue forward, besides allowing the distinction between most vowels according to height. Moreover, the fundamental frequency is significantly influenced by the height of the vowels, i.e., the data from this study support the existence of an intrinsic F0, across age and gender. Gender was also found to cause significant variations in F2 and in duration. The values of both parameters were higher in females. Age, on the other hand, reflected only the duration of vowels, with higher values in 7-year-old subjects. This work has provided an initial contribution to knowledge about the acoustics of vowels produced by young speakers of European Portuguese

Da nova arquitectura europeia da supervisão bancária : considerações a propósito do mecanismo de resolução

Dissertação apresentada à Faculdade de Direito da Universidade de Coimbra no âmbito do 2º Ciclo de Estudos em Direito (conducente ao grau de Mestre), na área de especialização em Ciências Jurídico-Forense

On the Role of Dewetting Transitions in Host-Guest Binding Free Energy Calculations.

We use thermodynamic integration (TI) and explicit solvent molecular dynamics (MD) simulation to estimate the absolute free energy of host-guest binding. In the unbound state, water molecules visit all of the internally accessible volume of the host, which is fully hydrated on all sides. Upon binding of an apolar guest, the toroidal host cavity is fully dehydrated; thus, during the intermediate λ stages along the integration, the hydration of the host fluctuates between hydrated and dehydrated states. Estimating free energies by TI can be especially challenging when there is a considerable difference in hydration between the two states of interest. We investigate these aspects using the popular TIP3P and TIP4P water models. TI free energy estimates through MD largely depend on water-related interactions, and water dynamics significantly affect the convergence of binding free energy calculations. Our results indicate that wetting/dewetting transitions play a major role in slowing the convergence of free energy estimation. We employ two alternative approaches-one analytical and the other empirically based on actual MD sampling-to correct for the standard state free energy. This correction is sizable (up to 4 kcal/mol), and the two approaches provide corrections that differ by about 1 kcal/mol. For the system considered here, the TIP4P water model combined with an analytical correction for the standard state free energy provides higher overall accuracy. This observation might be transferable to other systems in which water-related contributions dominate the binding process

Varta ag seizes opportunity in segment set to dominate the battery market

This paper accesses VARTA AG as a potential PE House target. VARTAAG is a company present in some of the highest growing segments of the battery market–and has the technological and production capacity that allowing it to keep track with market growth. More over, VARTA has the technological capacity to tapinanun explored segment, by the company, of the battery market–the hight growth segment of the Electric Vehicle(EV) Batteries. This Investment Co capable of pursuing of interesting value creation strategies, EV Battery Facility and Materials Recycling facility, that make VARTA an interesting target fo ra Leveraged Buy Out(LBO)

Interclássico case study : the emotional factor of a luxury product and its implication on sales

This written dissertation focuses on several topics related to marketing such as consumer behavior, sales strategy and consumer-product involvement through the analysis of a case study about Interclássico - A Classic Cars seller, founded in 2004. The company is situated in Alcácer-do-Sal and is the main national player in the market. Additionally, the firm expands part of its sales internationally. The case study describes the company, its history and its growth in the past 3 years in terms of sales, the firm’s dimension and market share comparing to its main competitors. Ultimately, this dissertation evolves around the consumer for this type of product, his motivations and purchasing process for a Classic Car. The focus of this study is to understand the relevant factors in the decision making process and the importance of these attributes for buyers. Results of this research are presented and interpreted in order to formulate useful recommendations to improve the firm’s marketing and sales strategy. At the end of this dissertation, a chapter dedicated as a Teaching Note is available alongside a set of guidelines in order to discuss this case study in a classroom setting.Esta dissertação escrita incide sobre vários tópicos relacionados com marketing, como comportamento de consumidor, estratégia de vendas e o envolvimento do consumidor-produto através da análise de um caso de estudo sobre a Interclássico - Um vendedor de Carros Clássicos, fundada em 2004. A empresa está situada em Alcácer-do- Sal e é a principal firma no mercado nacional de Clássicos. Adicionalmente, a empresa expande parte de suas vendas a nível internacional. O caso de estudo descreve a empresa, o seu historial e crescimento nos últimos 3 anos em termos de vendas, da sua dimensão e de quota de mercado da firma em comparação com os seus principais concorrentes. Em última análise, esta dissertação gira em torno do consumidor para este tipo de produto, as suas motivações e o seu processo de compra de um Carro Clássico. O foco deste estudo é compreender os factores relevantes no processo de tomada de decisão e a importância desses atributos para os compradores. Os resultados desta pesquisa são apresentados e interpretados a fim de formular recomendações úteis para melhorar a estratégia de marketing e de vendas da empresa. No final desta dissertação, um capítulo dedicado a uma Nota de Ensino se encontra disponível a par de um conjunto de orientações, a fim de abordar este caso de estudo em sala de aula

A monolithic conservative level set method with built-in redistancing

We introduce a new level set method for representing evolving interfaces. In the case of divergence-free velocity fields, the new method satisfies a conservation principle. Conservation is important for many applications such as modeling two-phase incompressible flow. In the present implementation, the conserved quantity is defined as the integral of a smoothed characteristic function. The new approach embeds level sets into a volume of fluid formulation. The evolution of an approximate signed distance function is governed by a conservation law for its (smoothed) sign. The non-linear level set transport equation is regularized by adding a flux correction term that assures a non-singular Jacobian and penalizes deviations from a distance function. The result is a locally conservative level set method with built-in elliptic redistancing. The continuous model is monolithic in the sense that the level set transport model, the volume of fluid law of mass conservation, and the minimization problem that preserves the approximate distance function property are incorporated into a single equation. There is no need for any extra stabilization, artificial compression, flux limiting, redistancing, mass correction, and other numerical fixes which are commonly used in level set or volume of fluid methods. In addition, there is just one free parameter that controls the strength of regularization and penalization in the model. The accuracy and conservation properties of the monolithic finite element / level set method are illustrated by the results of numerical studies for passive advection of free interfaces

Gibbs-Donnan and specific ion interaction theory descriptions of the effect of ionic strength on proton dissociation of alginic acid

The apparent proton dissociation constants of a commercial alginic acid have been obtained in KNO3 and NaCl at concentrations ranging between 0.01 and 2 mol·L-1. An analysis of the dependence on the ionic strength at a constant value of the dissociation degree was done by means of empirical functions derived from the Gibbs-Donnan formalism for polyelectrolytes and a specific ion interaction theory (SIT). Both functions were able to fit the experimental data, although SIT yielded rather high errors in the fitted parameters due to a problem of multicollinearity, in contrast to the function derived from the Gibbs-Donnan approach.This work was funded by the projects BQU2002-02133 (from the Ministerio de Ciencia y Tecnología of Spain) and PGDIT02TAM10302PR (from the Xunta de Galicia). C.R.C. benefited from a FPU grant of the Ministerio de Educación, Cultura y Deporte of Spain