951 resultados para Contreras, Battle of, 1847
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Since data-taking began in January 2004, the Pierre Auger Observatory has been recording the count rates of low energy secondary cosmic ray particles for the self-calibration of the ground detectors of its surface detector array. After correcting for atmospheric effects, modulations of galactic cosmic rays due to solar activity and transient events are observed. Temporal variations related with the activity of the heliosphere can be determined with high accuracy due to the high total count rates. In this study, the available data are presented together with an analysis focused on the observation of Forbush decreases, where a strong correlation with neutron monitor data is found.
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The Pierre Auger Observatory is a detector for ultra-high energy cosmic rays. It consists of a surface array to measure secondary particles at ground level and a fluorescence detector to measure the development of air showers in the atmosphere above the array. The ""hybrid"" detection mode combines the information from the two subsystems. We describe the determination of the hybrid exposure for events observed by the fluorescence telescopes in coincidence with at least one water-Cherenkov detector of the surface array. A detailed knowledge of the time dependence of the detection operations is crucial for an accurate evaluation of the exposure. We discuss the relevance of monitoring data collected during operations, such as the status of the fluorescence detector, background light and atmospheric conditions, that are used in both simulation and reconstruction. (C) 2010 Elsevier B.V. All rights reserved.
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Data collected by the Pierre Auger Observatory through 31 August 2007 showed evidence for anisotropy in the arrival directions of cosmic rays above the Greisen-Zatsepin-Kuz`min energy threshold, 6 x 10(19) eV. The anisotropy was measured by the fraction of arrival directions that are less than 3.1 degrees from the position of an active galactic nucleus within 75 Mpc (using the Veron-Cetty and Veron 12th catalog). An updated measurement of this fraction is reported here using the arrival directions of cosmic rays recorded above the same energy threshold through 31 December 2009. The number of arrival directions has increased from 27 to 69, allowing a more precise measurement. The correlating fraction is (38(-6)(+7))%, compared with 21% expected for isotropic cosmic rays. This is down from the early estimate of (69-(+11)(13))%. The enlarged set of arrival directions is examined also in relation to other populations of nearby extragalactic objects: galaxies in the 2 Microns All Sky Survey and active galactic nuclei detected in hard X-rays by the Swift Burst Alert Telescope. A celestial region around the position of the radiogalaxy Cen A has the largest excess of arrival directions relative to isotropic expectations. The 2-point autocorrelation function is shown for the enlarged set of arrival directions and compared to the isotropic expectation. (C) 2010 Elsevier B.V. All rights reserved.
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The Pierre Auger Observatory is a hybrid detector for ultra-high energy cosmic rays. It combines a surface array to measure secondary particles at ground level together with a fluorescence detector to measure the development of air showers in the atmosphere above the array. The fluorescence detector comprises 24 large telescopes specialized for measuring the nitrogen fluorescence caused by charged particles of cosmic ray air showers. In this paper we describe the components of the fluorescence detector including its optical system, the design of the camera, the electronics, and the systems for relative and absolute calibration. We also discuss the operation and the monitoring of the detector. Finally, we evaluate the detector performance and precision of shower reconstructions. (C) 2010 Elsevier B.V All rights reserved.
Measurement of the energy spectrum of cosmic rays above 10(18) eV using the Pierre Auger Observatory
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We report a measurement of the flux of cosmic rays with unprecedented precision and Statistics using the Pierre Auger Observatory Based on fluorescence observations in coincidence with at least one Surface detector we derive a spectrum for energies above 10(18) eV We also update the previously published energy spectrum obtained with the surface detector array The two spectra are combined addressing the systematic uncertainties and, in particular. the influence of the energy resolution on the spectral shape The spectrum can be described by a broken power law E(-gamma) with index gamma = 3 3 below the ankle which is measured at log(10)(E(ankle)/eV) = 18 6 Above the ankle the spectrum is described by a power law with index 2 6 followed by a flux suppression, above about log(10)(E/eV) = 19 5, detected with high statistical significance (C) 2010 Elsevier B V All rights reserved
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The air fluorescence detector of the Pierre Auger Observatory is designed to perforin calorimetric measurements of extensive air showers created by Cosmic rays of above 10(18) eV. To correct these measurements for the effects introduced by atmospheric fluctuations, the Observatory contains a group Of monitoring instruments to record atmospheric conditions across the detector site, ail area exceeding 3000 km(2). The atmospheric data are used extensively in the reconstruction of air showers, and are particularly important for the correct determination of shower energies and the depths of shower maxima. This paper contains a summary of the molecular and aerosol conditions measured at the Pierre Auger Observatory since the start of regular operations in 2004, and includes a discussion of the impact of these measurements oil air shower reconstructions. Between 10(18) and 10(20) eV, the systematic Uncertainties due to all atmospheric effects increase from 4% to 8% in measurements of shower energy, and 4 g cm(-2) to 8 g cm(-2) in measurements of the shower maximum. (C) 2010 Elsevier B.V. All rights reserved.
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A rationalization of the known difference between the (3,4)J(C4H1) and (3,4)J(C1H4) couplings transmitted mainly through the 7-bridge in norbornanone is presented in terms of the effects of hyperconjugative interactions involving the carbonyl group. Theoretical and experimental studies Of (3,4)J(CH) couplings were carried out in 3-endo- and 3-exo-X-2-norbornanone derivatives (X = Cl, Br) and in exo- and endo-2-noborneol compounds. Hyperconjugative interactions were studied with the natural bond orbital (NBO) method. Hyperconjugative interactions involving the carbonyl pi*c(2) =o and sigma*c(2) =o antibonding orbitals produce a decrease of three-bond contribution to both (3,4) J(C4H1) and (3,4)J(C1H4) couplings. However, the latter antibonding orbital also undergoes a strong sigma c(3)-c(4) ->sigma*c(2) =o interaction, which defines an additional coupling pathway for (3,4)J(C4H1) but not for (3,4)J(C1H4). This pathway is similar to that known for homoallylic couplings, the only difference being the nature of the intermediate antibonding orbital; i.e. for (3,4)J(C4H1) it is of sigma*-type, while in homoallylic couplings it is of pi*-type. Copyright (c) 2007 John Wiley & Sons, Ltd.
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The theme of family in literature and in popular discourse occurs at times when the family as an institution is under attack. Attacks against the family coupled with defence of the family are viewed as the barometer of people’s satisfaction with the society in which they live. This outpouring of emotion, whether it is in defence of or attacking the family, is the result of the family’s position on the bridge between nature and society – a fortunate (or a detrimental) link between an individual and the units that make up a society. Across the United States and much of the western world, the battle for gay marriage and inclusive civil unions has revealed the fissures in our collective moral view of the family. The conservative concern about the absence of ‘family values’ is magnified by our situation in a world of flux. Inflation, war, terrorist threats, and the depletion of natural resources are but a few examples. When so much is unknown, how do we position ourselves? What anchors us to the past, gives us comfort in the present, and supports us in the future if not the family? Alternatively, what coddles us more in the past, shackles us more to the present, and lulls us more into a fixed conception of the future than the family? My research is not a sociological survey into the family nor does it stake any claims to understanding the present state of the family in society. The study seeks, however, to shed light on the rhetorical uses of the family by analysing two novels that are inextricably concerned with the theory of the family in times of heightened social change. In particular, my research focuses upon the social role and political meaning of the family in Anna Karenina and Jia.
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Throughout the Christian story, Church doctrine and ecclesiology have been shrouded in controversy. From the Council of Nicea in 325, when are early Church fathers debated about the Trinity of Christ all the way to the modern day with Vatican II theological controversies have been important in the molding of Christian doctrine on the structure, role, and function of the Church. What makes those controversies different from the ones I treat in my thesis is that the previously mentioned controversies did not lead to schismatic divisions in the Church. The Donatist controversy and Luther's theological battle with Karlstadt were major movements that endangered the unity of the Church. These controversies propagated crucial writings and teachings in two major areas. The first area is the spiritual power and validity of the sacraments. Second is the role, function, and ecclesiology of the Church, with particular attention to the authority of the ministry. I want to demonstrate that these controversies refined the Church's thinking on sacramental issues such as baptism and Eucharist, as well as address the question of who has the power in the Church? And to what extent do they have the power to press reforms?
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Last week I sat down with a Brazilian acquaintance who was shaking his head over the state of national politics. A graduate of a military high school, he'd been getting e-mails from former classmates, many of them now retired army officers, who were irate over the recent presidential elections. "We need to kick these no-good Petistas out of office," one bristled, using the derogatory shorthand for members of the ruling Workers Party, or PT in Portuguese.
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Neoliberalism and developmentalism are the two alternative forms of economic and political organization of capitalism. Since the 2008 global financial crisis we see the demise of neoliberalism in rich countries, as state intervention and regulation increased, opening room for a third historical developmentalism (the first was mercantilism, the second, Fordism). Not only because of major market failures, not only because the market is definitely unable to assure financial stability and full employment, an active macroeconomic policy is being required. Modern economies are divided into a competitive and a non-competitive sector; for the coordination of the competitive sector the market is irreplaceable and regulation as well as strategic industrial policy will be pragmatically adopted following the subsidiarity principle, whereas for the non-competitive sector, state coordination and some state ownership are usually more efficient. Besides, the fact that capitalist economies are increasingly diversified and complex is an argument against the two extremes – against statism as well as neoliberalism – in so far that they require market coordination combined with increased regulation. But the third developmentalism probably will not be progressive as was the second, because the social-democratic political parties are disoriented. They won the battle for the welfare state, which neoliberalism was unable to dismantle, but the competition of low wage developing countries and immigration continue to offer arguments to conservative political parties that defend the reduction of the cost of labor contracts or the or precarization of labor.
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This report tells a story which started as an idea that came to us to fight the battle-cry feeling commonly known as stress and anxiety. Before creating the solution of the idea, we first need to understand the feelings underneath and its effects on our well-being. Throughout the course of our lives, we experience states of weakness and fear. These feelings can arise, for instance, while we are in an emergency room. Needless to say, how much it would have imaginable effects on children, who are unfamiliar to such environments. We ran through a serious of scenarios to find the most suitable solution, among them the study of interaction with positive expressions by Dr. Baldwin, proved to be a valued resource. It was reduced due to its length and to be suitable to our public audience. The game was then created in order to reduce or even eliminate the stress and anxiety of children. Since the game was initially released, some modifications had been made but the original idea - interaction with positive expressions – remained. When the time came, we asked children to play one of the two versions of the game while waiting in the emergency room. This not only created a diversion for them but also a learning experience as it displayed some hospital equipment. The difference between the two versions is that one provides expressions, while the other does not. After all our hard work, we felt rewarded because the project proved its worth and we would see that in the expressions on children’s faces while they played. Most importantly, their anxiety level numbers were significantly reduced during that short period of time.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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In the present work, tellurite 20Li(2)O-80TeO(2) glasses were prepared with identical nominal composition under different glass-forming histories to produce a stressed and stress-free samples. X-ray Diffraction (XRD) and Differential Scanning Calorimetry (DSC) techniques were used to study the effects of the glass-forming histories on the thermal and structural properties of these glasses. The gamma-TeO2 (metastable), alpha-TeO2 and alpha-Li2Te2O5 phases were identified during the controlled devitrification in these glasses. The mestastable character of the gamma-TeO2 phase was clearly observed in the glass under stress but this effect is not so clear in the stress-free glass. The gamma-TeO2 and alpha-TeO2 phases crystallizes during the initial stages of crystallization in both studied glasses while the alpha-Li2Te2O5 phase crystallize in the final stages of the crystallization. The activation energies and Avrami exponent were calculated for both studied glasses with different particle size leading to E-3 > E-2 > E-1 for stressed glass and E-3 > E-2 approximate to E-1 for stress-free glass, where E-1, E-2 and E-3 were associated to the gamma-TeO2, alpha-TeO2 and alpha-Li2Te2O5 phases, respectively. The observed distinct (n) over bar (1) < <(n)over bar>(2) < <(n)over bar>(3) in both glasses is an indicative that nucleation and growth takes place by more than one mechanism in the early stages of the crystallization. (C) 2011 Elsevier B.V. All rights reserved.
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We discuss in this paper equations describing processes involving non-linear and higher-order diffusion. We focus on a particular case (u(t) = 2 lambda (2)(uu(x))(x) + lambda (2)u(xxxx)), which is put into analogy with the KdV equation. A balance of nonlinearity and higher-order diffusion enables the existence of self-similar solutions, describing diffusive shocks. These shocks are continuous solutions with a discontinuous higher-order derivative at the shock front. We argue that they play a role analogous to the soliton solutions in the dispersive case. We also discuss several physical instances where such equations are relevant.