Fazendo arte na matemática

Esta palestra tem como objetivo explicitar relações entre Matemática e Arte que podem criar possibilidades de um olhar diferenciado de nossos jovens estudantes – se nos voltarmos para provocá-los a focalizar tais relações – a fim de não perderem sua capacidade de criação em razão diante da forma fragmentada da organização da escola. Nesta perspectiva, procuro movimentos de ordem do conhecimento matemático (escolar) que levem a trabalhá-lo de modo integrado, valorizando a matemática e a arte frente a formação humanística do ser humano. Elaborar o olhar atento do artista dentro da prática matemática se faz cada vez mais necessário para re-encantar os alunos para um melhor entendimento desta ciência tão presente na nossa vida, bem como do mundo e de seus objetos

Pattern and characteristics of advanced cancer patients admitted to hospices in Italy

Abstract The aim of this multicenter study was to assess the pattern and the characteristics of advanced cancer patients admitted to hospices. A consecutive sample of patients admitted in a period of 6 months was taken into consideration. Two hundred thirty-six patients admitted to hospices were consecutively assessed. Ninety-six percent of patients were admitted in acute hospital in the previous 3 months, with a mean time spent in hospital of 34.5 days, and 47 % of patients had received chemotherapy the month before hospice admission. Thirty-four percent of patients for whom data were available had significant persistent pain, and 44 % of them presented episodes of breakthrough pain. Sixty-one percent of patients were receiving opioid drugs at admission, and 70 % the day before death, with parenteral morphine and transdermal fentanyl being the opioids most frequently administered. The mean admission time in hospice was 18.4 days. Eighty-six percent died in hospice. Palliative sedation was performed in 25 % of patients who died in hospice. The short survival and the number of patients dying in hospice were the principal finding, as it appears that hospice admission is only one way for end of life treatments. Patients receive specialized palliative care only for 2-3 weeks before death, implying an inacceptable timing for patients with several problems presumed to be present early during the course of disease. Data from hospice activities in Italy strongly suggest to spread palliative care in other settings, other than home care and hospice, to intercept oncologic patients in their disease trajectory early

Ambiguities in the partial-wave analysis of pseudoscalar-meson photoproduction

Ambiguities in pseudoscalar-meson photoproduction, arising from incomplete experimental data, have analogs in pion-nucleon scattering. Amplitude ambiguities have important implications for the problems of amplitude extraction and resonance identification in partial-wave analysis. The effect of these ambiguities on observables is described. We compare our results with those found in earlier studies.Comment: 12 pages of text. No figure

The size of the proton - closing in on the radius puzzle

We analyze the recent electron-proton scattering data from Mainz using a dispersive framework that respects the constraints from analyticity and unitarity on the nucleon structure. We also perform a continued fraction analysis of these data. We find a small electric proton charge radius, r_E^p = 0.84_{-0.01}^{+0.01} fm, consistent with the recent determination from muonic hydrogen measurements and earlier dispersive analyses. We also extract the proton magnetic radius, r_M^p = 0.86_{-0.03}^{+0.02} fm, consistent with earlier determinations based on dispersion relations.Comment: 4 pages, 2 figures, fit improved, small modifications, section on continued fractions modified, conclusions on the proton charge radius unchanged, version accepted for publication in European Physical Journal

The Haunting National Memory of Vietnam A War Where the Losers Write the Story

Due to a stunning defeat in Vietnam, the years following the conflict were full of denial, shame, and silence. The silence in post Vietnam War America was followed by a resurgence of American nationalism in the 1980s at the hands of the United States government, which relied heavily on reshaping the war narrative as a way to designate meaning to American losses and regain the national image of superhero. While the rhetoric of presidents resonated with the American public it failed to mend the deep divides caused during the war period, which is most apparent through the creation of the Vietnam Veteran Memorial in Washington D.C. and the controversy that sparked around it. This paper provides a behind the scenes look at the making of the Vietnam Veteran Memorial, a process which put history on trial as perennial questions like how should a story be told, who should tell it, and what story should be told, were at the forefront of public discourse. Scholarship on public memory insists that one must understand the complex and invariably contested processes that society undergoes when forming devices of commemoration, noting that nation’s histories are rarely unfiltered. Memories are at the core of national identity, even if those memories have acquired unrecognizable mutations. On both an individual and national level, Americans carefully selected and embraced certain narratives from the Vietnam War period that they deemed relevant and worthy. The controversy that arose around the Vietnam Veteran Memorial, the fine attention on behalf of U.S. presidents through their rhetoric, and the scholarship explaining shifts in collective memory all yield significant truths in regards to the United States national identity and democratic processes around writing history for the pedagogy of future generations

Dispersion-Theoretical Analysis of the Nucleon Electromagnetic Formfactors

Dispersion relations allow for a coherent description of the nucleon electromagnetic form factors measured over a large range of momentum transfer, $Q^2 \simeq 0 \ldots 35$ GeV$^2$. Including constraints from unitarity and perturbative QCD, we present a novel parametrisation of the absorptive parts of the various isoscalar and isovector nucleon form factors. Using the current world data, we obtain results for the electromagnetic form factors, nucleon radii and meson couplings. We stress the importance of measurements at large momentum transfer to test the predictions of perturbative QCD.Comment: 33 pp, RevTEX or plain LaTeX, 7 figures (in ffig.uu

Structural behaviour of contemporary vaulted spaces with complex ashlars: the Abeille’s sail vault

The aim of the research is to investigate the static and dynamic behaviour of contemporary vaulted spaces, generated by the Flat Vault of Abeille patented in 1699. In fact, its reinterpre-tation and its use in architecture can both enhance the existing architectural heritage and char-acterize the new construction of building through the use of traditional construction materials and techniques. It follows that the identification of this “new type” of vault is essential to de-sign it correctly and to optimize the geometry for structural purposes. The Abeille-Type ashlar is a polyhedron that has two axial sections, in the shape of an isosceles trapezoid, oriented in opposite directions. The arrangement of the ashlar takes place in the two orthogonal directions creating a bidirectional flat plate, with a single type of optimized ashlar, whose geometry guarantees the mutual support of the individual blocks of the vaulted system, once assembly is complete. Starting from this ashlar and applying its deformation on curved surfaces, it is therefore possible to design “contemporary” types of vaults, characterized by complex ashlars in order to optimized both an aesthetic-formal and a structural function. The research proposes to apply already consolidated structural analysis methodologies – on traditional vaults – on this structure and describes the results of an experimental with quasi-static tests on a 1:8 small-scale vault model made of 3D printed blocks assembled with dry joints. In particular, shear in-plane and tilting tests were carried out by means of manual ac-tuators and controlled with incremental displacements. Different configurations are investi-gated both for the shear failure (simple or pure shear) and the tilting collapse (different in-plane angle). The results experimentally obtained were analysed in terms of damage/collapse mechanisms, strengths capacity and ultimate displacements. The Distinct Element Method (DEM) will be used for the numerical analyzes, being until now the most accurate and realistic for masonry structures, since it can take into consideration their discontinuous nature and the interlocking/toothing of the individual elements. In fact, it allows to investigate the vault ashlars as rigid and separate entities, witch interact with each other through the block planar interfaces; so the stability and the deformation of the whole vault is managed by the join contacts. Both experimental and numerical results furnish important data to formulate the behaviour of this vault. After the validation the results are extended to a full-scale vault by means of the similarity criteria, whose efficacy in the generalization of the results from the model to the prototype is demonstrated. In this way, the model can be finally adopted to simulate the be-haviour of a contemporary vault with the Abeille-Type ashlars

The First 1 1/2 Years of TOTEM Roman Pot Operation at LHC

Since the LHC running season 2010, the TOTEM Roman Pots (RPs) are fully operational and serve for collecting elastic and diffractive proton-proton scattering data. Like for other moveable devices approaching the high intensity LHC beams, a reliable and precise control of the RP position is critical to machine protection. After a review of the RP movement control and position interlock system, the crucial task of alignment will be discussed.Comment: 3 pages, 6 figures; 2nd International Particle Accelerator Conference (IPAC 2011), San Sebastian, Spain; contribution MOPO01

Nucleon Form Factors in Dispersion Theory

Dispersion relations provide a powerful tool to analyse the electromagnetic form factors of the nucleon both in the space-like and time-like regions with constraints from other experiments, unitarity, and perturbative QCD. We give a brief introduction into dispersion theory for nucleon form factors and present first results from our ongoing form factor analysis. We also calculate the two-pion continuum contribution to the isovector spectral functions drawing upon the new high statistics measurements of the pion form factor by the CMD-2, KLOE, and SND collaborations.Comment: 9 pages, 9 figures, invited talk at the Symposium "20 Years of Physics at the Mainz Microtron MAMI", October 20-22, 2005, Mainz, German

Growth of the [110] oriented TiO2 nanorods on ITO substrates by sputtering technique for dye-sensitized solar cells

TiO2 films have been deposited on ITO substrates by dc reactive magnetron sputtering technique. It has been found that the sputtering pressure is a very important parameter for the structure of the deposited TiO2 films. When the pressure is lower than 1 Pa, the deposited has a dense structure and shows a preferred orientation along the [101] direction. However, the nanorod structure has been obtained as the sputtering pressure is higher than 1 Pa. These nanorods structure TiO2 film shows a preferred orientation along the [110] direction. The x-ray diffraction and the Raman scattering measurements show both the dense and the nanostructure TiO2 films have only an anatase phase, no other phase has been obtained. The results of the SEM show that these TiO2 nanorods are perpendicular to the ITO substrate. The TEM measurement shows that the nanorods have a very rough surface. The dye-sensitized solar cells (DSSCs) have been assembled using these TiO2 nanorod films prepared at different sputtering pressures as photoelectrode. And the effect of the sputtering pressure on the properties of the photoelectric conversion of the DSSCs has been studied.This work is supported by the project PEst-OE/FIS/UI0068/2014-CEFITEC