10,018 research outputs found
Mutual information between geomagnetic indices and the solar wind as seen by WIND : implications for propagation time estimates
The determination of delay times of solar wind conditions at the sunward libration point to effects on Earth is investigated using mutual information. This measures the amount of information shared between two timeseries. We consider the mutual information content of solar wind observations, from WIND, and the geomagnetic indices. The success of five commonly used schemes for estimating interplanetary propagation times is examined. Propagation assuming a fixed plane normal at 45 degrees to the GSE x-axis (i.e. the Parker Spiral estimate) is found to give optimal mutual information. The mutual information depends on the point in space chosen as the target for the propagation estimate, and we find that it is maximized by choosing a point in the nightside rather than dayside magnetosphere. In addition, we employ recurrence plot analysis to visualize contributions to the mutual information, this suggests that it appears on timescales of hours rather than minutes
Statistical Description of Hydrodynamic Processes in Ionic Melts with taking into account Polarization Effects
Statistical description of hydrodynamic processes for ionic melts is proposed
with taking into account polarization effects caused by the deformation of
external ionic shells. This description is carried out by means of the Zubarev
nonequilibrium statistical operator method, appropriate for investigations of
both strong and weak nonequilibrium processes. The nonequilibrium statistical
operator and the generalized hydrodynamic equations that take into account
polarization processes are received for ionic-polarization model of ionic
molten salts when the nonequilibrium averaged values of densities of ions
number, their momentum, dipole momentum and total energy are chosen for the
reduced description parameters. A spectrum of collective excitations is
investigated within the viscoelastic approximation for ion-polarization model
of ionic melts.Comment: 24 pages, RevTex4.1-format, no figure
Commissioning of the LHC Current Leads
The powering of the LHC superconducting magnets relies on more than 3000 current leads transporting the current to/from the cryogenic environment and rated at currents ranging from 60 A to 13000 A. The design of these leads, about 1000 of which are based on high temperature superconducting material, was entirely done at CERN, where prototype assemblies were also assembled and tested, while the series production and testing was done in external laboratories and companies on the basis of build-to-print specifications. This report summarizes the results of the tests performed during the commissioning of the LHC machine, when the leads underwent the thermal and electrical cycles necessary for the powering of the LHC superconducting circuit
A Three Dimensional Lattice of Ion Traps
We propose an ion trap configuration such that individual traps can be
stacked together in a three dimensional simple cubic arrangement. The isolated
trap as well as the extended array of ion traps are characterized for different
locations in the lattice, illustrating the robustness of the lattice of traps
concept. Ease in the addressing of ions at each lattice site, individually or
simultaneously, makes this system naturally suitable for a number of
experiments. Application of this trap to precision spectroscopy, quantum
information processing and the study of few particle interacting system are
discussed.Comment: 4 pages, 4 Figures. Fig 1 appears as a composite of 1a, 1b, 1c and
1d. Fig 2 appears as a composite of 2a, 2b and 2
Power, norms and institutional change in the European Union: the protection of the free movement of goods
How do institutions of the European Union change? Using an institutionalist approach, this article highlights the interplay between power, cognitive limits, and the normative order that underpins institutional settings and assesses their impact upon the process of institutional change. Empirical evidence from recent attempts to reinforce the protection of the free movement of goods in the EU suggests that, under conditions of uncertainty, actors with ambiguous preferences assess attempts at institutional change on the basis of the historically defined normative order which holds a given institutional structure together. Hence, path dependent and incremental change occurs even when more ambitious and functionally superior proposals are on offer
Dynamical Realization of Macroscopic Superposition States of Cold Bosons in a Tilted Double Well
We present exact expressions for the quantum sloshing of Bose-Einstein
condensates in a tilted two-well potential. Tunneling is suppressed by a small
potential difference between wells, or tilt. However, tunneling resonances
occur for critical values of the tilt when the barrier is high. At resonance,
tunneling times on the order of 10-100 ms are possible. Furthermore, such
tilted resonances lead to a dynamical scheme for creating few-body NOON-like
macroscopic superposition states which are protected by the many body
wavefunction against potential fluctuations.Comment: 6 pages, 5 figures, final version, only minor changes from previous
arXiv versio
Hyperglycemia Has a Greater Impact on Left Ventricle Function in South Asians Than in Europeans
OBJECTIVE Diabetes is associated with left ventricular (LV) diastolic and systolic dysfunction. South Asians may be at particular risk of developing LV dysfunction owing to a high prevalence of diabetes. We investigated the role of diabetes and hyperglycemia in LV dysfunction in a community-based cohort of older South Asians and white Europeans. RESEARCH DESIGN AND METHODS Conventional and Doppler echocardiography was performed in 999 participants (542 Europeans and 457 South Asians aged 58–86 years) in a population-based study. Anthropometry, fasting bloods, coronary artery calcification scoring, blood pressure, and renal function were measured. RESULTS Diabetes and hyperglycemia across the spectrum of HbA1c had a greater adverse effect on LV function in South Asians than Europeans (N-terminal-probrain natriuretic peptide β ± SE 0.09 ± 0.04, P = 0.01, vs. −0.04 ± 0.05, P = 0.4, P for HbA1c/ethnicity interaction 0.02), diastolic function (E/e′ 0.69 ± 0.12, P < 0.0001, vs. 0.09 ± 0.2, P = 0.6, P for interaction 0.005), and systolic function (s′ −0.11 ± 0.06, P = 0.04, vs. 0.14 ± 0.09, P = 0.1, P for interaction 0.2). Multivariable adjustment for hypertension, microvascular disease, LV mass, coronary disease, and dyslipidemia only partially accounted for the ethnic differences. Adverse LV function in diabetic South Asians could not be accounted for by poorer glycemic control or longer diabetes duration. CONCLUSIONS Diabetes and hyperglycemia have a greater adverse effect on LV function in South Asians than Europeans, incompletely explained by adverse risk factors. South Asians may require earlier and more aggressive treatment of their cardiometabolic risk factors to reduce risks of LV dysfunction
Towards the Design of Power Switches Utilizing HTS Material
Conventional superconducting switches for power applications, which operate at liquid helium temperature, generally utilize Nb-Ti superconductor in a cupro-nickel matrix. For superconducting circuits based on High Temperature Superconductors (HTS) that work at higher temperatures, the associated superconducting switches must also be based on HTS. This paper addresses the issues concerning the requirements and the appropriate design of HTS switches, including approaches to fast triggering
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