Ionizing radiation exposure of LDEF

The Long Duration Exposure Facility (LDEF) was launched into orbit by the Space Shuttle 'Challenger' mission 41C on 6 April 1984 and was deployed on 8 April 1984. The original altitude of the circular orbit was 258.5 nautical miles (479 km) with the orbital inclination being 28.5 degrees. The 21,500 lb NASA Langley Research Center satellite, having dimensions of some 30x14 ft was one of the largest payloads ever deployed by the Space Shuttle. LDEF carried 57 major experiments and remained in orbit five years and nine months (completing 32,422 orbits). It was retrieved by the Shuttle 'Columbia' on January 11, 1990. By that time, the LDEF orbit had decayed to the altitude of 175 nm (324 km). The experiments were mounted around the periphery of the LDEF on 86 trays and involved the representation of more than 200 investigators, 33 private companies, 21 universities, seven NASA centers, nine Department of Defense laboratories and eight foreign countries. The experiments covered a wide range of disciplines including basic science, electronics, optics, materials, structures, power and propulsion. The data contained in the LDEF mission represents an invaluable asset and one which is not likely to be duplicated in the foreseeable future. The data and the subsequent knowledge which will evolve from the analysis of the LDEF experiments will have a very important bearing on the design and construction of the Space Station Freedom and indeed on other long-term, near-earth orbital space missions. A list of the LDEF experiments according to experiment category and sponsor is given, as well as a list of experiments containing radiation detectors on LDEF including the LDEF experiment number, the title of the experiment, the principal investigator, and the type of radiation detectors carried by the specific experiment

Optimal Summation and Integration by Deterministic, Randomized, and Quantum Algorithms

We survey old and new results about optimal algorithms for summation of finite sequences and for integration of functions from Hoelder or Sobolev spaces. First we discuss optimal deterministic and randomized algorithms. Then we add a new aspect, which has not been covered before on conferences about (quasi-) Monte Carlo methods: quantum computation. We give a short introduction into this setting and present recent results of the authors on optimal quantum algorithms for summation and integration. We discuss comparisons between the three settings. The most interesting case for Monte Carlo and quantum integration is that of moderate smoothness k and large dimension d which, in fact, occurs in a number of important applied problems. In that case the deterministic exponent is negligible, so the n^{-1/2} Monte Carlo and the n^{-1} quantum speedup essentially constitute the entire convergence rate. We observe that -- there is an exponential speed-up of quantum algorithms over deterministic (classical) algorithms, if k/d tends to zero; -- there is a (roughly) quadratic speed-up of quantum algorithms over randomized classical algorithms, if k/d is small.Comment: 13 pages, contribution to the 4th International Conference on Monte Carlo and Quasi-Monte Carlo Methods, Hong Kong 200

Re-assigning (1x2) reconstruction of rutile TiO_2(110) from DFT+U calculations

Physically reasonable electronic structures of reconstructed rutile TiO_2(110)-(1x2) surfaces were studied using density functional theory (DFT) supplemented with Hubbard U on-site Coulomb repulsion acting on the d electrons, so called as the DFT+U approach. Two leading reconstruction models proposed by Onishi--Iwasawa and Park et al. were compared in terms of their thermodynamic stabilities.Comment: 4 pages, 4 figures, 2 table

Rubus wittigianus spec. nov., eine sich ausbreitende Brombeerart in Westfalen und bei Osnabrück

Rubus wittigianus H. E.Weber spec. nov. wird als neue Art der Sektion Rubus serie Sylvatici (P. J. Müller) Focke beschrieben. Ihr bislang bekanntes Verbreitungsgebiet erstreckt sich von Wellendorf (Landkreis Osnabrück) durch Westfalen bis Bad Lippspringe.Die Art ist durch Fotos (auch des Holotypus) abgebildet, und eine Liste der bisherigen Fundorte ist beigefügt.Rubus wittigianus H. E. Weber spec. nov. is described as a new species of sect. Rubus ser. Sylvatici (P. J. Müller) Focke. Its known distribution reaches from a site southeastern of Osnabrück (Lower Saxony) to Bad Lippspringe in eastern Westfalia. The species is illustrated by photographs (including the holotype). A list of localities where it has been found so far is added

Zur Verbreitung und Soziologie des Reinweißen Wasserhahnenfußes (Ranunculus ololeucos LLOYD) in Mitteleuropa : mit 1 Tabelle

Der früher in oligotrophen Heidegewässern verbreitete, heute vom Aussterben bedrohte Reinweiße Wasserhahnenfuß ist heute noch von vier Fundpunkten in Mitteleuropa bekannt. Die einstige und heutige, sich westlich der Linie Hamburg - Osnabrück - Krefeld erstreckende Verbreitung ist in einer Liste aller bekannten Fundorte mit Meßtischblatt-Rasterangaben wiedergegeben. Die Situation in Niedersachen und im benachbarten Westfalen ist zusätzlich in einer Karte dargestellt. Ranunculus ololeucos bildet in nährstoffarmen Klarwasserbereichen eine der Ufervegetation vorgelagerte eigene Schwimmblatt-Gesellschaft. Diese ist hier auf der Grundlage von Aufnahmen aus Niedersachsen und Westfalen als eine zum Verband Hydrocolylo- Baldellion (Klasse Littorelletea) gehörende Assoziation Ranunculetum ololeuci ass. nov. beschrieben

Weitere Ergänzungen zur Brombeerflora Westdeutschlands

Vier in Deutschland neu nachgewiesene Brombeerarten (Rubus L. Rosaceae), von denen zwei neu beschrieben sind, werden behandelt: (1) Rubus laetus Beek (Sect. Rubus subsect. Rubus), nachgewiesen im mittleren Westfalen; (2) R. discors Beek (Sect. Rubus ser. Sylvatici [P.J. Müller] Focke), im westlichen Niedersachsen und Westfalen; (3) R. hilsianus H. E. Weber spec. nov. (Sect. Rubus ser. Glandulosi Wimmer & Grab.), im südöstlichen Niedersachsen, in Hessen (Taunus) und im Saarland; (4) R. loosii H. E. Weber spec. nov. (Sect. Corylifolii Lindley ser. Subthyrsoidei Focke), stellenweise häufig im mittleren Westfalen. Die Arten sind detailliert beschrieben und durch Fotos von Herbarexemplaren abgebildet. Ihre Ökologie und Verbreitung sind behandelt.Four bramble species (Rubus L. Rosaceae), new to Germany, are treated (two of them are described as new species): (1) Rubus laetus Beek (R. nitidiformis auct. pro parte, Sect. Rubus subsect. Rubus), found in central Westfalia; (2) R. discors Beek (Sect. Rubus ser. Sylvatici [P. J. Müller] Focke), recorded from western Lower Saxony and Westfalia; (3) R. hilsianus H. E. Weber spec. nov. (Sect. Rubus ser. Glandulosi Wimmer & Grab.) occurring in southeastern Lower Saxony, Hesse (Taunus mountains) and in the Saar district; (4) R. ioosii H. E. Weber spec. nov. (Sect. Corylifolii Lindley ser. Subthyrsoidei Focke), locally frequent in central Westfalia. The species are described in detail, illustrated by photographs of herbarium specimens, their ecology and distribution is pointed out

Limodorum abortivum, eine mediterran-submediterrane Orchidee am Silberberg bei Osnabrück

Limodorum abortivum (L.) Sw. (Orchidaceae) wurde 1932 auf dem Silberberg bei Natrup-Hagen (Landkreis Osnabrück) gefunden. Das Belegstück ging leider verloren, aber die Angabe stammt von dem zuverlässigen Pflanzenkenner Wilhelm Meyer (Direktor des Botanischen Gartens in Oldenburg), und das Exemplar wurde nach einer Zeitungsnotiz von Hunderten von Besuchern, darunter von zahlreichen Botanikern besichtigt. Der Silberberg ist der weitaus nördlichste Fundort dieser thermophilen Orchidee.Limodorum abortivum (L.) Sw. (Orchidaceae) was found in the year 1932 at the "Silberberg" near Osnabrück (Lower Saxony). Unfortunately, the voucher specimen got lost, but it was determined by the outstanding expert Wilhelm Meyer (Director of the Botanical Garden at Oldenburg) and after a public notice shown to hundreds of visitors including many botanists. The Silberberg is by far the northernmost site for that thermophilous orchid