29,280 research outputs found

    Effect of facility variation on the acoustic characteristics of three single stream nozzles

    Get PDF
    The characteristics of the jet noise produced by three single stream nozzles were investigated statistically at the NASA-Lewis Research Center outdoor jet acoustic facility. The nozzles consisted of a 7.6 cm diameter convergent conical, a 10.2 cm diameter convergent conical and an 8-lobe daisy nozzle with 7.6 cm equivalent diameter flow area. The same nozzles were tested previously at cold flow conditions in other facilities such as the Royal Aircraft Establishment (RAE) 7.3 m acoustic wind tunnel. The acoustic experiments at NASA covered pressure ratios from 1.4 to 2.5 at total temperatures of 811 K and ambient. The data obtained with four different microphone arrays are compared. The results are also compared with data taken at the RAE facility and with a NASA prediction procedure

    On CrC^r-closing for flows on 2-manifolds

    Full text link
    For some full measure subset B of the set of iet's (i.e. interval exchange transformations) the following is satisfied: Let X be a CrC^r, 1r1\le r\le \infty, vector field, with finitely many singularities, on a compact orientable surface M. Given a nontrivial recurrent point pMp\in M of X, the holonomy map around p is semi-conjugate to an iet E:[0,1)[0,1).E :[0,1) \to [0,1). If EBE\in B then there exists a CrC^r vector field Y, arbitrarily close to X, in the CrC^r-topology, such that Y has a closed trajectory passing through p.Comment: 7 pages, 1 figur

    Hydrogen bonds and asymmetrical heat diffusion in a-Helices. A Computational Analysis

    Full text link
    In this work, we report the heat rectifying capability of a-helices. Using molecular dynamics simulations we show an increased thermal diffusivity in the C-Terminal to N-Terminal direction of propagation. The origin of this effect seems to be a function of the particular orientation of the hydrogen bonds stabilizing these a-helices. Our results may be relevant for the design of thermal rectification devices for materials science and lend support to the role of normal length hydrogen bonds in the asymmetrical energy flow in proteins

    EU Law, International Law, and Economic Sanctions Against Terrorism: The Judiciary in Distress?

    Get PDF
    This Article seeks to examine the relationship between European Union (“EU”) law, international law, and the protection of fundamental rights in light of recent case law of the European Court of Justice (“ECJ”) and the Court of First Instance (“CFI”) relating to economic sanctions against individuals. It first looks at the judgment in Kadi. After a short presentation of the factual and legal background, it explores the question of whether the EU has competence to adopt smart sanctions. It then examines whether the EU is bound by resolutions of the UNSC, whether the ECJ has jurisdiction to review Community measures implementing such resolutions, and looks at the applicable standard of judicial scrutiny. It analyzes the contrasting views of the CFI, the Advocate General, and the ECJ, taking account also of the case law of the European Court of Human Rights (“ECtHR” or “Strasbourg Court”). Further, the Article explores the consequences of annulling the contested regulation. It then turns to discussing CFI case law in relation to sanctions lists drawn up not by the UNSC but by the Community. The Article concludes by welcoming the judgment of the ECJ. While its reasoning on the issue of Community competence is questionable, once such competence is established, it is difficult to support the abrogation of Community standards for the protection of fundamental rights. Such standards should ensure procedural due process while recognizing the importance of public security