1,272 research outputs found

    The New Space Network: the Tracking and Data Relay Satellite System

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    When the Tracking and Data Relay Satellite System (TDRSS)is completed, the system, together with its various NASA support elements will be known simply as the Space Networks. It will substantially increase information exchanges between low-orbiting spacecraft and the ground. The structural design, functions, earth-based links, and present and future use are discussed

    Apollo Soyuz

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    The mission, background, and spacecraft of the Apollo Soyuz Test Project are summarized. Scientific experiments onboard the spacecraft are reviewed, along with reentry procedures. A small biography of each of the five astronauts (U.S. and Russian) is also presented

    Replacement of the retractable roof at the Bad Hersfeld monastery

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    Laser structuring of NMC 811 high energy electrodes in battery production for enhancing the electrochemical performance for xEV energy storage systems

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    Layered oxide cathodes, especially thick-film electrodes like lithium nickel manganese cobalt oxide, NMC, are under continuously investigation to meet the ambitious requirements, e.g. 700 Wh/l, for future Li-ion batteries in electric drive applications. The objective of the most current studies is to reduce the Co content with a concurrent increasing Ni-content in the NMC cathodes such as NMC 811 [1]. It must not leave the fact out of consideration, that NMC cathodes suffer from low high rate capability and corresponding low capacity retention at high C-rates. In particular, the negative impact is even higher for thick-film high energy cathodes. To counteract the negative effect, high repetition ultrafast laser ablation is applied to create appropriate 3D electrode designs [2]. New Li+-diffusion pathways, applied by the laser structuring process, shell enhance electrolyte wettability and reduce overpotentials at high C-rates. It is attempted to integrate the laser structuring into a continuous roll-to-roll electrode production process. In this way, the positive properties achieved through 3D structuring can also be obtained for Li-ion batteries that are produced on a large scale. By using this novel production technology, future NMC batteries can be produced with improved performance characteristics for xEV applications. Furthermore, this technology can also be applied for other generation 3b battery cells. This work is performed under the frame of the RealLi! project, in which the following aspects are covered: a) Development of thick film NMC811 electrodes with high areal capacity b) Passivation approach to improve cycle stability and lifetime c) Cell Assembly and electrochemical characterization d) Holistic evaluation of the potential environmental impact of the NMC811 cells via life cycle assessment e) An experimentally validated electrochemical model to describe electrode structures and their optimization. f) Improved electrochemical performance of NMC811 electrodes on a laboratory scale by using 3D laser structuring. g) Scale up of the 3D laser structuring process and corresponding improved electrochemical performance of NMC811 electrodes in pouch cell format by using 3D laser ablation

    On the theory of resonances in non-relativistic QED and related models

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    We study the mathematical theory of quantum resonances in the standard model of non-relativistic QED and in Nelson's model. In particular, we estimate the survival probability of metastable states corresponding to quantum resonances and relate the resonances to poles of an analytic continuation of matrix elements of the resolvent of the quantum Hamiltonian.Comment: 28 page

    Pluto: A Monte Carlo Simulation Tool for Hadronic Physics

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    Pluto is a Monte-Carlo event generator designed for hadronic interactions from Pion production threshold to intermediate energies of a few GeV per nucleon, as well as for studies of heavy ion reactions. This report gives an overview of the design of the package, the included models and the user interface.Comment: XI International Workshop on Advanced Computing and Analysis Techniques in Physics Research, April 23-27 2007, Amsterdam, the Netherland

    Hidden potential in predicting wintertime temperature anomalies in the Northern Hemisphere

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    Variability of the North Atlantic Oscillation (NAO) drives wintertime temperature anomalies in the Northern Hemisphere. Dynamical seasonal prediction systems can skilfully predict the winter NAO. However, prediction of the NAO-dependent air temperature anomalies remains elusive, partially due to the low variability of predicted NAO. Here, we demonstrate a hidden potential of a multi-model ensemble of operational seasonal prediction systems for predicting wintertime temperature by increasing the variability of predicted NAO. We identify and subsample those ensemble members which are close to NAO index statistically estimated from initial autumn conditions. In our novel multi-model approach, the correlation prediction skill for wintertime Central Europe temperature is improved from 0.25 to 0.66, accompanied by an increased winter NAO prediction skill of 0.9. Thereby, temperature anomalies can be skilfully predicted for the upcoming winter over a large part of the Northern Hemisphere through increased variability and skill of predicted NAO

    Nonlocal Effects on the Magnetic Penetration Depth in d-wave Superconductors

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    We show that, under certain conditions, the low temperature behavior of the magnetic penetration depth λ(T)\lambda(T) of a pure d-wave superconductor is determined by nonlocal electrodynamics and, contrary to the general belief, the deviation Δλ(T)=λ(T)λ(0)\Delta\lambda(T) = \lambda(T)-\lambda(0) is proportional to T^2 and not T. We predict that the Δλ(T)T2\Delta\lambda(T)\propto T^2 dependence, due to nonlocality, should be observable experimentally in nominally clean high-T_c superconductors below a crossover temperature T=(ξo/λo)Δo1KT^* = (\xi_o/\lambda_o)\Delta_o \sim 1 K. Possible complications due to impurities, surface quality and crystal axes orientation are discussed.Comment: REVTeX3.0; 4 pages, 1 EPS figure (included); Submitted to Phys. Rev. Let
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