2,566 research outputs found

    Are Drivers\u27 Manuals Understandable?

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    In 1984, researchers determined that the readability of state drivers\u27 manuals exceeded the average literacy levels in the United States. Because text complexity threatened the ability of license applicants and practicing drivers to understand the information presented in the manuals, a potential safety risk was indicated. This study analyzes recent editions of the manuals using readability formulas and formal text presentation ratings. It was found that the average difficulty of the drivers\u27 manuals was reduced by more than one grade level and that the 1994 manuals are clearly superior to their earlier versions, but that, in the interest of highway safety, improvements should still be sought

    Fermi Surface of KFe2_2As2_2 from Quantum Oscillations in Magnetostriction

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    We present a study of the Fermi surface of KFe2_2As2_2 single crystals. Quantum oscillations were observed in magnetostriction measured down to 50 mK and in magnetic fields HH up to 14 T. For HcH \parallel c, the calculated effective masses are in agreement with recent de Haas-van Alphen and ARPES experiments, showing enhanced values with respect to the ones obtained from previous band calculations. For HaH \parallel a, we observed a small orbit at a cyclotron frequency of 64 T, characterized by an effective mass of 0.8me\sim 0.8 m_e, supporting the presence of a three-dimensional pocket at the Z-point.Comment: SCES Conference, Tokyo 201

    Leistungen und Entwicklung von Öko- Milchviehbetrieben mit geringem Kraftfuttereinsatz in Baden-Württemberg

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    The aim of this study was the analysis of dairy farms in Baden-Württemberg producing milk without or with only a little amount of concentrate. 12 biological managed farms have been visited and consulted by questionnaire in 2010. Also the results of milk yield testing have been examined. Economic calculations were run for a comparison to conventionally working dairy farms. In 2015 the results were for 10 of these farms updated. Since 2010 the structure of the farms remained almost unchanged (number of cows, milk yield, cultivated area). The proportion of pasture from grassland increased from 45 to 53%. The ecological-low input drived production system leads to better conditions for profitable milk production compared to conventional dairy farms

    Lack of coupling between superconductivity and orthorhombic distortion in stoichiometric single-crystalline FeSe

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    The coupling between superconductivity and othorhombic distortion is studied in vapor-grown FeSe single crystals using high-resolution thermal-expansion measurements. In contrast to the Ba122-based (Ba122) superconductors, we find that superconductivity does not reduce the orthorhombicity below Tc. Instead we find that superconductivity couples strongly to the in-plane area, which explains the large hydrostatic pressure effects. We discuss our results in light of the spinnematic scenario and argue that FeSe has many features quite different from the typical Fe-based superconductors

    Disordered Topological Insulators via CC^*-Algebras

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    The theory of almost commuting matrices can be used to quantify topological obstructions to the existence of localized Wannier functions with time-reversal symmetry in systems with time-reversal symmetry and strong spin-orbit coupling. We present a numerical procedure that calculates a Z_2 invariant using these techniques, and apply it to a model of HgTe. This numerical procedure allows us to access sizes significantly larger than procedures based on studying twisted boundary conditions. Our numerical results indicate the existence of a metallic phase in the presence of scattering between up and down spin components, while there is a sharp transition when the system decouples into two copies of the quantum Hall effect. In addition to the Z_2 invariant calculation in the case when up and down components are coupled, we also present a simple method of evaluating the integer invariant in the quantum Hall case where they are decoupled.Comment: Added detail regarding the mapping of almost commuting unitary matrices to almost commuting Hermitian matrices that form an approximate representation of the sphere. 6 pages, 6 figure

    Development and Short-Range Testing of a 100 kW Side-Illuminated Millimeter-Wave Thermal Rocket

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    The objective of the phase described here of the Millimeter-Wave Thermal Launch System (MTLS) Project was to launch a small thermal rocket into the air using millimeter waves. The preliminary results of the first MTLS flight vehicle launches are presented in this work. The design and construction of a small thermal rocket with a planar ceramic heat exchanger mounted along the axis of the rocket is described. The heat exchanger was illuminated from the side by a millimeter-wave beam and fed propellant from above via a small tank containing high pressure argon or nitrogen. Short-range tests where the rocket was launched, tracked, and heated with the beam are described. The rockets were approximately 1.5 meters in length and 65 millimeters in diameter, with a liftoff mass of 1.8 kilograms. The rocket airframes were coated in aluminum and had a parachute recovery system activated via a timer and Pyrodex. At the rocket heat exchanger, the beam distance was 40 meters with a peak power intensity of 77 watts per square centimeter. and a total power of 32 kilowatts in a 30 centimeter diameter circle. An altitude of approximately 10 meters was achieved. Recommendations for improvements are discussed

    Localized inhibition of protein phosphatase 1 by NUAK1 promotes spliceosome activity and reveals a MYC-sensitive feedback control of transcription.

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    Deregulated expression of MYC induces a dependence on the NUAK1 kinase, but the molecular mechanisms underlying this dependence have not been fully clarified. Here, we show that NUAK1 is a predominantly nuclear protein that associates with a network of nuclear protein phosphatase 1 (PP1) interactors and that PNUTS, a nuclear regulatory subunit of PP1, is phosphorylated by NUAK1. Both NUAK1 and PNUTS associate with the splicing machinery. Inhibition of NUAK1 abolishes chromatin association of PNUTS, reduces spliceosome activity, and suppresses nascent RNA synthesis. Activation of MYC does not bypass the requirement for NUAK1 for spliceosome activity but significantly attenuates transcription inhibition. Consequently, NUAK1 inhibition in MYC-transformed cells induces global accumulation of RNAPII both at the pause site and at the first exon-intron boundary but does not increase mRNA synthesis. We suggest that NUAK1 inhibition in the presence of deregulated MYC traps non-productive RNAPII because of the absence of correctly assembled spliceosomes

    The ordered K-theory of a full extension

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    Let A be a C*-algebra with real rank zero which has the stable weak cancellation property. Let I be an ideal of A such that I is stable and satisfies the corona factorization property. We prove that 0->I->A->A/I->0 is a full extension if and only if the extension is stenotic and K-lexicographic. As an immediate application, we extend the classification result for graph C*-algebras obtained by Tomforde and the first named author to the general non-unital case. In combination with recent results by Katsura, Tomforde, West and the first author, our result may also be used to give a purely K-theoretical description of when an essential extension of two simple and stable graph C*-algebras is again a graph C*-algebra.Comment: Version IV: No changes to the text. We only report that Theorem 4.9 is not correct as stated. See arXiv:1505.05951 for more details. Since Theorem 4.9 is an application to the main results of the paper, the main results of this paper are not affected by the error. Version III comments: Some typos and errors corrected. Some references adde
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