Interdisciplinaridade e contextualização da física através do esporte

Nosso objetivo é desenvolver metodologias de ensino de física sobre temas que abordem aspectos físicos dos esportes ou da prática do exercício físico. Nesse trabalho apresentamos uma aula sobre velocidade instantânea e velocidade média, destinada a alunos que iniciam o estudo da cinemática. Desenvolvemos o conteúdo da aula através dos resultados obtidos nas provas de corrida e natação da Olimpíada de Pequim. Escolhemos em trabalhar com a Interdisciplinaridade Física dos Esportes por entendermos que no Brasil e no mundo os esportes passaram a estar presente no cotidiano das pessoas, seja por motivos de saúde, lazer ou profissional, dessa forma, a contextualização se torna imediata, trazendo o tema para o cotidiano dos estudantes e despertando maior interesse por assuntos de ciências

Coherent Vector Meson Production in Ultra-Peripheral Heavy-Ion Collisions at STAR

We report the first observation of coherent rho0 production (AuAu->AuAu rho0) and rho0 production accompanied by mutual nuclear Coulomb excitation (AuAu->Au*Au*rho0),and the observation of coherent e+e- pair production (AuAu->Au*Au*e+e-) in ultra-peripheral relativistic heavy-ion collisions (UPCs). We give transverse momentum, mass, and rapidity distributions. The cross sections for coherent rho0 production at sqrt{s_NN}=130 and 200 GeV are in agreement with theoretical predictions, which treat rho^0 production and nuclear excitation as independent processes.Comment: 4 pages, 4 figures, Talk presented at Quark Matter 2002, Nantes, France, July 200

Anclaje de las expectativas de inflación ante choques de oferta adversos

In order to create an environment of low and stable inflation in Mexico it has been necessary to generate a framework for the conduction of monetary policy focused on price stability along with fiscal discipline. This paper describes some structural achievements to control inflation that have been attained in Mexico. In addition, it shows empirical evidence in favor of the anchoring of inflation expectations, particularly those for the medium and long term, being recently strengthened. Considering three episodes, within the period 2004-2012, in which inflation was subject to different supply shocks, it finds that during the episode in 2012 inflation expectations showed greater stability. Results show that the response from inflation expectations to supply shocks has diminished over time, up to values that are not significantly different from zero. This suggests a strengthening of the credibility of the Bank of Mexico's commitment to price stability

Chiral Dynamics and the S11(1535)S_{11}(1535) Nucleon Resonance

The $SU(3)$ chiral effective lagrangian at next-to-leading order is applied to the S-wave meson-baryon interaction in the energy range around the $\eta N$ threshold. Potentials are derived from this lagrangian and used in a coupled channel calculation of the $\pi N$, $\eta N$, $K \Lambda$, $K \Sigma$ system in the isospin-$1/2$, $l=0$ partial wave. Using the same parameters as obtained from a fit to the low energy $\overline{K} N$ data it is found that a quasi-bound $K \Sigma$-state is formed, with properties remarkably similar to the $S_{11}(1535)$ nucleon resonance. In particular, we find a large partial decay width into $\eta N$ consistent with the empirical data.Comment: 9 pages, 6 postscript figures, e-mail: [email protected] ; [email protected] [email protected]

Coherent Electromagnetic Processes in Ultra-Peripheral Heavy-Ion Collisions

We report measurements for coherent rho^0 production, AuAu->AuAu rho^0, and coherent rho^0 and e^+e^- pair production accompanied by mutual nuclear Coulomb excitation, AuAu->Au*Au* rho^0 and AuAuee, in ultra-peripheral relativistic gold-gold collisions (UPC). We discuss transverse momentum, mass, and rapidity distributions. The two photon-process of e^+e^- pair production is an important probe of strong field QED because of the large coupling Z*alpha=0.6. At sqrt{s}=200GeV, the e^+e^- production cross section agrees with lowest order QED calculations. The cross sections for coherent rho^0 production at sqrt{s}=130 and 200GeV are in agreement with theoretical predictions. The calculations for both, coherent e^+e^- and rho^0 production treat nuclear excitation as independent process.Comment: Presentation at the 'International Conference on the Structure and Interactions of the Photon-Photon 2003, Frascati, Italy'; 6 pages, 8 figures Corrected reference

Cascade coherence transfer and magneto-optical resonances at 455 nm excitation of Cesium

We present and experimental and theoretical study of nonlinear magneto-optical resonances observed in the fluorescence to the ground state from the 7P_{3/2} state of cesium, which was populated directly by laser radiation at 455 nm, and from the 6P_{1/2} and 6P_{3/2} states, which were populated via cascade transitions that started from the 7P_{3/2} state and passed through various intermediate states. The laser-induced fluorescence (LIF) was observed as the magnetic field was scanned through zero. Signals were recorded for the two orthogonal, linearly polarized components of the LIF. We compared the measured signals with the results of calculations from a model that was based on the optical Bloch equations and averaged over the Doppler profile. This model was adapted from a model that had been developed for D_1 and D_2 excitation of alkali metal atoms. The calculations agree quite well with the measurements, especially when taking into account the fact that some experimental parameters were only estimated in the model.Comment: small changes to text of previous version; 12 pages, 8 figure

Level-crossing spectroscopy of the 7, 9, and 10D_5/2 states of 133Cs and validation of relativistic many-body calculations of the polarizabilities and hyperfine constants

We present an experimental and theoretical investigation of the polarizabilities and hyperfine constants of D_J states in 133Cs for J=3/2 and J=5/2. New experimental values for the hyperfine constant A are obtained from level-crossing signals of the (7,9,10)D_5/2 states of 133Cs and precise calculations of the tensor polarizabilities alpha_2. The results of relativistic many-body calculations for scalar and tensor polarizabilities of the (5-10)D_3/2 and (5-10)D_5/2 states are presented and compared with measured values from the literature. Calculated values of the hyperfine constants A for these states are also presented and checked for consistency with experimental values.Comment: 12 pages, revtex4, 11 figure file

Affinity chromatography in dynamic combinatorial libraries: one-pot amplification and isolation of a strongly binding receptor

We report the one-pot amplification and isolation of a nanomolar receptor in a multibuilding block aqueous dynamic combinatorial library using a polymer-bound template. By appropriate choice of a poly(N,N-dimethylacrylamide)-based support, unselective ion-exchange type behaviour between the oppositely charged cationic guest and polyanionic hosts was overcome, such that the selective molecular recognition arising in aqueous solution reactions is manifest also in the analogous templated solid phase DCL syntheses. The ability of a polymer bound template to identify and isolate a synthetic receptor via dynamic combinatorial chemistry was not compromised by the large size of the library, consisting of well over 140 theoretical members, demonstrating the practical advantages of a polymer-supported DCL methodology

Transforming Women\u27s Water Burdens into Opportunities

In rural Uganda, dawn approaches as and a mother and daughter gather their empty jericans (3- to 5- gallon water containers), dirty pots and soiled clothing and begin their daily chores. A local ven­dor sells clean water, but at 25 cents per jerican it\u27s too costly to buy the amount they need: the family makes less than $1 a day. So they go in search of another source, a task which can sometimes take all day. The water weighs nearly 8 pounds per gallon, and they are unable to carry enough water home to accomplish their chores so they carry out their activities at the single water source. The women spend hours washing and drying the clothes, pots and dishes, and bathing themselves, the children and sometimes even the animals, and then they begin the long journey home on foot. This time, in addition to the clean laundry and pots, they are carrying 5 gallons of water -- nearly 44 pounds and often contaminated (WHO 2008). Five gallons of water may be enough to cook and provide drinking water for their family for maybe a few days. With jericans atop their heads, shoulders and backs, they strain to keep the delicate balance, careful not to lose a single drop on the rough road home