766 research outputs found

    Seeing Is Believing: A Practitioner\u27s Guide to the Admissibility of Demonstrative Computer Evidence, 1998 John M. Manos Writing Competition on Evidence

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    As computer equipment itself becomes more financially accessible, more experts are using computer simulations as demonstrative evidence during their trial testimony. However, this use of computer simulations presents several novel, complex issues. Part II will explore the backgrounds of demonstrative evidence, computerization, and the use of computer simulation for demonstrative evidence. Part III will discuss and analyze several relevant issues, including attorney training, expert knowledge, judicial confusion, additional evidentiary issues, and the possible prejudicial influence of demonstrative computer simulations. This discussion concludes with some general thoughts regarding the use of demonstrative computer simulation to illustrate expert testimony

    Dissipation in Mesoscopic Superconductors with Ac Magnetic Fields

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    The response of mesoscopic superconductors to an ac magnetic field is investigated both experimentally and with numerical simulations. We study small square samples with dimensions of the order of the penetration depth. We obtain the ac susceptibitity χ=χ+iχ\chi=\chi'+i\chi'' at microwave frequencies as a function of the dc magnetic field HdcH_{dc}. We find that the dissipation, given by χ\chi'', has a non monotonous behavior in mesoscopic samples. In the numerical simulations we obtain that the dissipation increases before the penetration of vortices and then it decreases abruptly after vortices have entered the sample. This is verified experimentally, where we find that χ\chi'' has strong oscillations as a function of HdcH_{dc} in small squares of Pb.Comment: 4 pages, 2 figure

    Updated tests of scaling and universality for the spin-spin correlations in the 2D and 3D spin-S Ising models using high-temperature expansions

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    We have extended, from order 12 through order 25, the high-temperature series expansions (in zero magnetic field) for the spin-spin correlations of the spin-S Ising models on the square, simple-cubic and body-centered-cubic lattices. On the basis of this large set of data, we confirm accurately the validity of the scaling and universality hypotheses by resuming several tests which involve the correlation function, its moments and the exponential or the second-moment correlation-lengths.Comment: 21 pages, 8 figure

    Determination of Gd concentration profile in UO2-Gd2O3 fuel pellets

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    A transversal mapping of the Gd concentration was measured in UO2-Gd2O3 nuclear fuel pellets by electron paramagnetic resonance spectroscopy (EPR). The quantification was made from the comparison with a Gd2O3 reference sample. The nominal concentration in the pellets is UO2: 7.5 % Gd2O3. A concentration gradient was found, which indicates that the Gd2O3 amount diminishes towards the edges of the pellets. The concentration varies from (9.3 +/- 0.5)% in the center to (5.8 +/- 0.3)% in one of the edges. The method was found to be particularly suitable for the precise mapping of the distribution of Gd3+ ions in the UO2 matrix.Comment: 10 pages, 5 figures, 2 tables. Submitted to Journal of Nuclear Material

    Pure spin current manipulation in antiferromagnetically exchange coupled heterostructures

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    We present a model to describe the spin currents generated by ferromagnet/spacer/ferromagnet exchange coupled trilayer systems and heavy metal layers with strong spin-orbit coupling. By exploiting the magnitude of the exchange coupling (oscillatory RKKY-like coupling) and the spin-flop transition in the magnetization process, it has been possible to produce spin currents polarized in arbitrary directions. The spin-flop transition of the trilayer system originates pure spin currents whose polarization vector depends on the exchange field and the magnetization equilibrium angles. We also discuss a protocol to control the polarization sign of the pure spin current injected into the metallic layer by changing the initial conditions of magnetization of the ferromagnetic layers previously to the spin pumping and inverse spin Hall effect experiments. The small differences in the ferromagnetic layers lead to a change in the magnetization vector rotation that permits the control of the sign of the induced voltage components due to the inverse spin Hall effect. Our results can lead to important advances in hybrid spintronic devices with new functionalities, particularly, the ability to control microscopic parameters such as the polarization direction and the sign of the pure spin current through the variation of macroscopic parameters, such as the external magnetic field or the thickness of the spacer in antiferromagnetic exchange coupled systems.Fil: Avilés Félix, L.. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Butera, Alejandro Ricardo. Comision Nacional de Energía Atómica. Gerencia de Área Investigaciones y Aplicaciones no Nucleares. Gerencia de Física (Centro Atómico Bariloche). División Resonancias Magnéticas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: González Chávez, D. E.. Centro Brasileiro de Pesquisas Físicas; BrasilFil: Sommer, R. L.. Centro Brasileiro de Pesquisas Físicas; BrasilFil: Gomez, Javier Enrique. Comision Nacional de Energía Atómica. Gerencia de Área Investigaciones y Aplicaciones no Nucleares. Gerencia de Física (Centro Atómico Bariloche). División Resonancias Magnéticas; Argentin

    The effect of grades on the preference effect : Grading Reduces Consideration of Disconfirming Evidence

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    The tendency to look for evidence that supports, rather than questions, one's viewpoint (preference effect) is a pervasive phenomenon. Although one important goal of education is developing critical thinking, the widespread practice of grading might discourage students in appreciating disconfirming evidence. We hypothesized that individual grading increases the preference effect. In Experiment 1, participants who expected to be graded exhibited a higher preference effect compared to participants who expected their work to be merely visible. Experiment 2 replicated this effect and further showed that grading increased participants' perception of a competitive social comparison. Implications for educational policies are discussed.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

    High-Temperature series for the RPn1RP^{n-1} lattice spin model (generalized Maier-Saupe model of nematic liquid crystals) in two space dimensions and with general spin dimensionality n

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    High temperature series expansions of the spin-spin correlation functions of the RP^{n-1} spin model on the square lattice are computed through order beta^{8} for general spin dimensionality n. Tables are reported for the expansion coefficients of the energy per site, the susceptibility and the second correlation moment.Comment: 6 pages, revtex, IFUM 419/FT, 2 figures not include
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