SCOLPIRE GLI EROI

Catalogo della mostra che riproponeva i maggiori monumenti risorgimentali italiani attraverso i loro bozzett

Da poesia na ciencia : fundadores do Instituto Histórico e Geográfico do Paraná, uma história de suas idéias. Curitiba, 1900

Orientadora : Ana Maria de O. BurmesterAutor não autorizou a divulgação do arquivo digitalDissertaçao (mestrado) - Universidade Federal do Paraná, Setor de Ciencias Humanas, Letras e ArtesInclui referênciasResumo: Este trabalho procurou analisar, do ponto de vista de uma história das idéias, o percurso intelectual dos fundadores do Instituto Histórico e Geográfico do Paraná, na virada do século XIX para o XX em Curitiba, para recuperar, em um momento de celebração nacional, propostas de criação de uma identidade paranaense para um Estado com uma história oficial recente. Através do conceito de configuração, de Norbert Elias, procura recuperar as diferentes relações estabelecidas pelos fundadores no seio da sociedade curitibana, procurando apreender o surgimento de uma intelectualidade comprometida com os novos ideais republicanos. Através do conceito de língua, de Sérgio Paulo Rouanet, procura pensar a circulação de várias correntes de pensamento próprias da época, através do exame dos periódicos e diários da capital de cuja produção participaram os fundadores. Através do conceito de invenção das tradições, de Eric Hobsbawn, procura explicar a necessidade de se criar uma identidade para o povo paranaense. Por fim, procura mostrar como a interpenetração das várias configurações surgidas, em especial, na última década do século XIX, possibilitou o surgimento de um discurso que ganharia caráter oficial, com a fundação do Instituto Histórico sendo um dos primeiros passos na criação do Movimento Paranista, que viria a dominar o cenário paranaense da I República

Influence of chemically synthesized powder addition on K0.5Na0.5NbO3 ceramic's properties

A new strategy to produce lead-free K0.5Na0.5NbO3 (KNN) piezoceramics with reliable and improved piezoelectric performance is presented for the first time. KNN powders were synthesized using two distinct synthesis routes: a mechanochemical activation-assisted solid-state route (KNNSSR) and a sol-gel modified Pechini method (KNNchem). KNNchem powders were mixed with KNNSSR at different weight ratios (0, 3, 5, 10 and 20 wt%), and the mixtures were conventionally consolidated and sintered at 1130 degrees C for 2 h. It was found that KNNchem powders influence crystal phase, microstructure and piezoelectric properties of the sintered pellets. Gradually increasing KNNchem content promotes the conversion of the undesired phase present in KNNSSR into the stoichiometric one. It is also proved that the addition of KNNchem between 5 and 10 wt% improves piezoelectric properties, eventually leading to a d(33) piezoelectric charge constant value of 113-115 pC/N. These values are among the highest reported for undoped KNN ceramics obtained by conventional sintering

Perturbation Theory for Metastable States of the Dirac Equation with Quadratic Vector Interaction

The spectral problem of the Dirac equation in an external quadratic vector potential is considered using the methods of the perturbation theory. The problem is singular and the perturbation series is asymptotic, so that the methods for dealing with divergent series must be used. Among these, the Distributional Borel Sum appears to be the most well suited tool to give answers and to describe the spectral properties of the system. A detailed investigation is made in one and in three space dimensions with a central potential. We present numerical results for the Dirac equation in one space dimension: these are obtained by determining the perturbation expansion and using the Pad\'e approximants for calculating the distributional Borel transform. A complete agreement is found with previous non-perturbative results obtained by the numerical solution of the singular boundary value problem and the determination of the density of the states from the continuous spectrum.Comment: 10 pages, 1 figur

Active Mass Under Pressure

After a historical introduction to Poisson's equation for Newtonian gravity, its analog for static gravitational fields in Einstein's theory is reviewed. It appears that the pressure contribution to the active mass density in Einstein's theory might also be noticeable at the Newtonian level. A form of its surprising appearance, first noticed by Richard Chase Tolman, was discussed half a century ago in the Hamburg Relativity Seminar and is resolved here.Comment: 28 pages, 4 figure