1,127 research outputs found

    NASA SBIR abstracts of 1990 phase 1 projects

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    The research objectives of the 280 projects placed under contract in the National Aeronautics and Space Administration (NASA) 1990 Small Business Innovation Research (SBIR) Phase 1 program are described. The basic document consists of edited, non-proprietary abstracts of the winning proposals submitted by small businesses in response to NASA's 1990 SBIR Phase 1 Program Solicitation. The abstracts are presented under the 15 technical topics within which Phase 1 proposals were solicited. Each project was assigned a sequential identifying number from 001 to 280, in order of its appearance in the body of the report. The document also includes Appendixes to provide additional information about the SBIR program and permit cross-reference in the 1990 Phase 1 projects by company name, location by state, principal investigator, NASA field center responsible for management of each project, and NASA contract number

    On Macroscopic Energy Gap for qq-Quantum Mechanical Systems

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    The q-deformed harmonic oscillator within the framework of the recently introduced Schwenk-Wess qq-Heisenberg algebra is considered. It is shown, that for "physical" values q1q\sim1, the gap between the energy levels decreases with growing energy. Comparing with the other (real) qq-deformations of the harmonic oscillator, where the gap instead increases, indicates that the formation of the macroscopic energy gap in the Schwenk-Wess qq-Quantum Mechanics may be avoided.Comment: 6 pages, TeX, PRA-HEP-92/1

    NASA SBIR abstracts of 1992, phase 1 projects

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    The objectives of 346 projects placed under contract by the Small Business Innovation Research (SBIR) program of the National Aeronautics and Space Administration (NASA) are described. These projects were selected competitively from among proposals submitted to NASA in response to the 1992 SBIR Program Solicitation. The basic document consists of edited, non-proprietary abstracts of the winning proposals submitted by small businesses. The abstracts are presented under the 15 technical topics within which Phase 1 proposals were solicited. Each project was assigned a sequential identifying number from 001 to 346, in order of its appearance in the body of the report. Appendixes to provide additional information about the SBIR program and permit cross-reference of the 1992 Phase 1 projects by company name, location by state, principal investigator, NASA Field Center responsible for management of each project, and NASA contract number are included

    First direct mass-measurement of the two-neutron halo nucleus 6He and improved mass for the four-neutron halo 8He

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    The first direct mass-measurement of 6^{6}He has been performed with the TITAN Penning trap mass spectrometer at the ISAC facility. In addition, the mass of 8^{8}He was determined with improved precision over our previous measurement. The obtained masses are mm(6^{6}He) = 6.018 885 883(57) u and mm(8^{8}He) = 8.033 934 44(11) u. The 6^{6}He value shows a deviation from the literature of 4σ\sigma. With these new mass values and the previously measured atomic isotope shifts we obtain charge radii of 2.060(8) fm and 1.959(16) fm for 6^{6}He and 8^{8}He respectively. We present a detailed comparison to nuclear theory for 6^6He, including new hyperspherical harmonics results. A correlation plot of the point-proton radius with the two-neutron separation energy demonstrates clearly the importance of three-nucleon forces.Comment: 4 pages, 2 figure

    On the deformability of Heisenberg algebras

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    Based on the vanishing of the second Hochschild cohomology group of the enveloping algebra of the Heisenberg algebra it is shown that differential algebras coming from quantum groups do not provide a non-trivial deformation of quantum mechanics. For the case of a q-oscillator there exists a deforming map to the classical algebra. It is shown that the differential calculus on quantum planes with involution, i.e. if one works in position-momentum realization, can be mapped on a q-difference calculus on a commutative real space. Although this calculus leads to an interesting discretization it is proved that it can be realized by generators of the undeformed algebra and does not posess a proper group of global transformations.Comment: 16 pages, latex, no figure

    Standardization of Marine Meteorological Data from FINO Offshore Platforms

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    KlimawandelDer Ausbau der Offshore-Windenergie gehört zu den erklärten Zielen der Bundesregierung. Um bessere Ken ntnisse der Bedingungen auf See zu erlangen, wurden drei Forschungsplattformen in der Nordsee (FINO 1 und 3) und Ostsee (FINO 2) errichtet. An diesen werden meteorologische und ozeanographische Größen in unterschiedlichen Höhen gemessen, um unter anderem Aussagen zu Vertikalprofilen der Windgeschwindigkeit treffen zu können. Da sich die Plattformen und Masten im Design unterscheiden und sich insbesondere bei den Windmessungen deutlich ein richtungsabhängiger Einfluss auf die Messungen zeigt, ist für die Vergleichbarkeit der Standorte eine standardisierte Auswertung der Messergebnisse erforderlich. Ziel des Projektes FINO-Wind ist es, die Vergleichbarkeit der Daten der drei Standorte zu verbessern und den Datennutzern nach standardisierten Methoden qualitätsgeprüfte Daten zur Verfügung zu stellen. Es sollen deshalb Standardisierungsverfahren zur Auswertung der Winddaten entwickelt werden. Insbesondere die verschiedenen Masteffekte werden eingehend untersucht und durch Windkanalmessungen, Vergleich mit LiDAR-Daten, CFD (Computational Fluid Dynamics)-Modellierungen und Anwendung der UAM (Uniform ambient flow mast correction)-Methode abgeschätzt. Daraus werden Korrekturfaktoren für Windmessungen abgeleitet, die später angewendet werden sollen. Die Messdaten, die als 10-Minuten-Werte vorliegen, werden des Weiteren einer umfassenden und automatisierten Qualitätsprüfung unterzogen. Dabei durchlaufen die Daten in aufeinanderfolgenden Schritten formale, klimatologische, zeitliche, Wiederholungs- und Konsistenzprüfungen und werden nach erfolgreichem Abschluss jeder Sequenz mit spezifischen Qualitätsflags gekennzeichnet. Aus der Analyse und dem Vergleich der Instrumentierung in unterschiedlichen Höhen, der Installation und Ausrichtung sowie die Mastkonstruktionen sollen Empfehlungen herausgearbeitet werden, wie zukünftige Anwendungen im Bereich der Offshore-Windmessungen verbessert werden können

    Multipair contributions to the spin response of nuclear matter

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    We analyse the effect of non-central forces on the magnetic susceptibility of degenerate Fermi systems. These include the presence of contributions from transitions to states containing more than one quasiparticle-quasihole pair, which cannot be calculated within the framework of Landau Fermi-liquid theory, and renormalization of the quasiparticle magnetic moment, as well as explicit non-central contributions to the quasiparticle interaction. Consequently, the relationship between the Landau parameters and the magnetic susceptibility for Fermi systems with non-central forces is considerably more complicated than for systems with central forces. We use sum-rule arguments to place a lower bound on the contribution to the static susceptibility coming from transitions to multipair states

    Ground State Electromagnetic Moments of <sup>37</sup>Ca

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    The hyperfine coupling constants of neutron deficient 37^{37}Ca were deduced from the atomic hyperfine spectrum of the 4s 2S1/24s~^2S_{1/2} \leftrightarrow 4p 2P3/24p~^2P_{3/2} transition in Ca II, measured using the collinear laser spectroscopy technique. The ground-state magnetic-dipole and spectroscopic electric-quadrupole moments were determined for the first time as μ=+0.7453(72)μN\mu = +0.7453(72) \mu_N and Q=15(11)Q = -15(11) e2e^2fm2^2, respectively. The experimental values agree well with nuclear shell model calculations using the universal sd model-space Hamiltonians versions A and B (USDA/B) in the sdsd-model space with a 95\% probability of the canonical nucleon configuration. It is shown that the magnetic moment of 39^{39}Ca requires a larger non-sdsd-shell component than that of 37^{37}Ca for good agreement with the shell-model calculation, indicating a more robust closed sub-shell structure of 36^{36}Ca at the neutron number NN = 16 than 40^{40}Ca. The results are also compared to valence-space in-medium similarity renormalization group calculations based on chiral two- and three-nucleon interactions

    Findings of the WMT'22 Shared Task on Large-Scale Machine Translation Evaluation for African Languages

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    We present the results of the WMT'22 Shared Task on Large-Scale Machine Translation Evaluation for African Languages. The shared task included both a data and a systems track, along with additional innovations, such as a focus on African languages and extensive human evaluation of submitted systems. We received 14 system submissions from 8 teams, as well as 6 data track contributions. We report a large progress in the quality of translation for African languages since the last iteration of this shared task: there is an increase of about 7.5 BLEU points across 72 language pairs, and the average BLEU scores went from 15.09 to 22.60
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