518 research outputs found

    Treaty of Amity, Commerce, and Navigation Between Brazil and the U.S.

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    This Article deals with the analytical history of the Treaty of Amity, Commerce and Navigation between the U.S. and Brazil. In the first part of the Article, the author analyzed all the provisions of the Treaty entered into between the two countries on December 12, 1828. The second part examined the historical causes for the early termination of the Treaty, 13 years after its execution. It suggests and evidences that the historical cause lies in a political factor, that is, the conflicts between a Republican form of government and the Brazilian Imperial political system. The third and final part of the Article deals with the economic history of investments and business between the two countries. It finalizes to suggest the economic losses to both countries in the absence of a new Treaty in force. It also makes an exhortation to both countries to enter into a new Treaty of Amity, Commerce and Navigatio

    Treaty of Amity, Commerce, and Navigation Between Brazil and the U.S.

    Get PDF
    This Article deals with the analytical history of the Treaty of Amity, Commerce and Navigation between the U.S. and Brazil. In the first part of the Article, the author analyzed all the provisions of the Treaty entered into between the two countries on December 12, 1828. The second part examined the historical causes for the early termination of the Treaty, 13 years after its execution. It suggests and evidences that the historical cause lies in a political factor, that is, the conflicts between a Republican form of government and the Brazilian Imperial political system. The third and final part of the Article deals with the economic history of investments and business between the two countries. It finalizes to suggest the economic losses to both countries in the absence of a new Treaty in force. It also makes an exhortation to both countries to enter into a new Treaty of Amity, Commerce and Navigatio

    Excitation of the odd-parity quasi-normal modes of compact objects

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    The gravitational radiation generated by a particle in a close unbounded orbit around a neutron star is computed as a means to study the importance of the ww modes of the neutron star. For simplicity, attention is restricted to odd parity (``axial'') modes which do not couple to the neutron star's fluid modes. We find that for realistic neutron star models, particles in unbounded orbits only weakly excite the ww modes; we conjecture that this is also the case for astrophysically interesting sources of neutron star perturbations. We also find that for cases in which there is significant excitation of quadrupole ww modes, there is comparable excitation of higher multipole modes.Comment: 18 pages, 21 figures, submitted to Phys. Rev.

    A new measure of health motivation influencing food choices and its association with food intakes and nutritional biomarkers in European adolescents

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    Objective:To develop a scale to assess health motivation influencing food choices and to explore its performance in the associations with food intakes and nutritional biomarkers. Design:Psychometric study using cross-sectional self-report questionnaires and nutritional biomarkers. Setting:Multi-centre investigation conducted in ten European cities. Participants:2954 adolescents who were included in the HELENA study and completed the Food Choices and Preferences (FCP) questionnaire. Results:Nineteen out of 124 items of the FCP questionnaire were in the same dimension. Sixteen presented adequate parameters for the Scale of evaluatiOn of Food choIcEs (SOFIE). The scores were positively associated with the intakes of cereals, dairy products, meats and eggs, and fish, as well as with blood concentrations of vitamin C, ß-carotene, n-3 fatty acids, cobalamin, holo-transcobalamin and folate; scores were negatively associated with the intake of alcohol. Conclusions:SOFIE can improve the assessment of motivation influencing food choices based on items with the best performance and is proposed as a new measure to health-related studies

    On the critical behavior of disordered quantum magnets: The relevance of rare regions

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    The effects of quenched disorder on the critical properties of itinerant quantum antiferromagnets and ferromagnets are considered. Particular attention is paid to locally ordered spatial regions that are formed in the presence of quenched disorder even when the bulk system is still in the paramagnetic phase. These rare regions or local moments are reflected in the existence of spatially inhomogeneous saddle points of the Landau-Ginzburg-Wilson functional. We derive an effective theory that takes into account small fluctuations around all of these saddle points. The resulting free energy functional contains a new term in addition to those obtained within the conventional perturbative approach, and it comprises what would be considered non-perturbative effects within the latter. A renormalization group analysis shows that in the case of antiferromagnets, the previously found critical fixed point is unstable with respect to this new term, and that no stable critical fixed point exists at one-loop order. This is contrasted with the case of itinerant ferromagnets, where we find that the previously found critical behavior is unaffected by the rare regions due to an effective long-ranged interaction between the order parameter fluctuations.Comment: 16 pp., REVTeX, epsf, 2 figs, final version as publishe

    Quantum Griffiths effects and smeared phase transitions in metals: theory and experiment

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    In this paper, we review theoretical and experimental research on rare region effects at quantum phase transitions in disordered itinerant electron systems. After summarizing a few basic concepts about phase transitions in the presence of quenched randomness, we introduce the idea of rare regions and discuss their importance. We then analyze in detail the different phenomena that can arise at magnetic quantum phase transitions in disordered metals, including quantum Griffiths singularities, smeared phase transitions, and cluster-glass formation. For each scenario, we discuss the resulting phase diagram and summarize the behavior of various observables. We then review several recent experiments that provide examples of these rare region phenomena. We conclude by discussing limitations of current approaches and open questions.Comment: 31 pages, 7 eps figures included, v2: discussion of the dissipative Ising chain fixed, references added, v3: final version as publishe

    Electron Dynamics in Nd1.85_{1.85}Ce.15_{.15}CuO4+δ_{4+\delta}: Evidence for the Pseudogap State and Unconventional c-axis Response

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    Infrared reflectance measurements were made with light polarized along the a- and c-axis of both superconducting and antiferromagnetic phases of electron doped Nd1.85_{1.85}Ce.15_{.15}CuO4+δ_{4+\delta}. The results are compared to characteristic features of the electromagnetic response in hole doped cuprates. Within the CuO2_2 planes the frequency dependent scattering rate, 1/τ(ω)\tau(\omega), is depressed below \sim 650 cm1^{-1}; this behavior is a hallmark of the pseudogap state. While in several hole doped compounds the energy scales associated with the pseudogap and superconducting states are quite close, we are able to show that in Nd1.85_{1.85}Ce.15_{.15}CuO4+δ_{4+\delta} the two scales differ by more than one order of magnitude. Another feature of the in-plane charge response is a peak in the real part of the conductivity, σ1(ω)\sigma_1(\omega), at 50-110 cm1^{-1} which is in sharp contrast with the Drude-like response where σ1(ω)\sigma_1(\omega) is centered at ω=0\omega=0. This latter effect is similar to what is found in disordered hole doped cuprates and is discussed in the context of carrier localization. Examination of the c-axis conductivity gives evidence for an anomalously broad frequency range from which the interlayer superfluid is accumulated. Compelling evidence for the pseudogap state as well as other characteristics of the charge dynamics in Nd1.85_{1.85}Ce.15_{.15}CuO4+δ_{4+\delta} signal global similarities of the cuprate phase diagram with respect to electron and hole doping.Comment: Submitted to PR
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