89 research outputs found

    Collapse of Nonlinear Gravitational Waves in Moving-Puncture Coordinates

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    We study numerical evolutions of nonlinear gravitational waves in moving-puncture coordinates. We adopt two different types of initial data -- Brill and Teukolsky waves -- and evolve them with two independent codes producing consistent results. We find that Brill data fail to produce long-term evolutions for common choices of coordinates and parameters, unless the initial amplitude is small, while Teukolsky wave initial data lead to stable evolutions, at least for amplitudes sufficiently far from criticality. The critical amplitude separates initial data whose evolutions leave behind flat space from those that lead to a black hole. For the latter we follow the interaction of the wave, the formation of a horizon, and the settling down into a time-independent trumpet geometry. We explore the differences between Brill and Teukolsky data and show that for less common choices of the parameters -- in particular negative amplitudes -- Brill data can be evolved with moving-puncture coordinates, and behave similarly to Teukolsky waves

    Kleegras-Feldversuch im ökologischen Anbau in Luxemburg

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    Futterleguminosen stellen in der organischen Milchviehhaltung die Basis der Winterfutterversorgung dar. Deshalb war es das Ziel dieser Studie Kleegras-Mischungen im biologischen Anbau in Luxemburg auf ihre Futterqualität zu prüfen. Dabei wurden in einem zweijährigen Feldversuch 11 Kleegras Mischungen zu unterschiedlichen Schnittzeitpunkten auf ihre Energiegehalte (NEL), ihr darmverdauliches Eiweiß (DVE) und ihre unbeständige Eiweiß Bilanz (OEB) mit Hilfe der Nahinfrarot Spektroskopie (NIRS) untersucht. Bei den einzelnen Mischungen wurden signifikante Unterschiede bei NEL, DVE und OEB festgestellt, sowohl zwischen den Schnitten als auch über alle Schnitte hinweg. Allerdings spielte der Anteil des Rotklees nicht die entscheidende Rolle, sondern die richtige Rotklee- bzw. Gras Sortenwahl. Die Ergebnisse zeigen die Wichtigkeit der geeigneten Sortenwahl für die unterschiedlichen Standortbedingungen in Luxemburg

    Wire scanners and vibrations: models and measurements

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    The new fast wire scanner foreseen to measure small emittance beams throughout the LHC injector chain will have a wire travelling at a speed of up to 20 m.s-1, with a requested wire position measurement accuracy in the order of a few microns. The vibration of the thin carbon wires used has been identified as one of the major error sources on the wire position accuracy. One of the most challenging and innovative developments in this project has been the work to quantify the effect of wire vibrations and fork deformation. The measurement strategy for the former is based on the piezo resistive effect of the wire itself, while the deflection of the fork supporting the wire has been measured by semiconductor strain gauges. Dynamic models of the wire and fork have been created to predict the behaviour of the fork-wire assembly and will be used for its optimisation. This contribution will discuss the measurement setup and the model development as well as their comparison. In addition it will show that this technology can easily be implemented in current operating devices without major modifications.Postprint (published version

    Magnetic nanodoping: Atomic control of spin states in cobalt doped silver clusters

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    The interaction of magnetic dopants with delocalized electron states can result in interesting many-body physics. Here, the magnetic properties of neutral and charged finite silver metal host clusters with a magnetic cobalt atom impurity were investigated experimentally by exploiting the complementary methods of Stern- Gerlach molecular beam deflection and x-ray magnetic circular dichroism spectroscopy and are accompanied by density functional theory calculations and charge transfer multiplet simulations. The influence of the number of valence electrons and the consequences of impurity encapsulation were addressed in free size-selected, singly cobalt-doped silver clusters CoAg0,n+ (n = 2–15). Encapsulation of the dopant facilitates the formation of delocalized electronic shells with complete hybridization of the impurity 3d- and the host 5s-derived orbitals, which results in impurity valence electron delocalization, effective spin relaxation, and a low-spin ground state. In the exohedral size regime, spin pairing in the free electron gas formed by the silver 5s electrons is the dominating driving force determining the local 3d occupation of the impurity and therefore, adjusting the spin magnetic moment accordingly

    Základy půdní úrodnosti

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    Zvyšování půdní úrodnosti bylo pro průkopníky ekologického zemědělství základem veškerého jejich úsilí. Přesto zachování úrodné půdy mnohdy nebyla věnována dostatečná pozornost. Ekologické zemědělství je však na přirozené půdní úrodnosti závislé. Oslabená a poškozená půda nám nemůže poskytnout to, co od ní očekáváme. Udržet úrodnost půdy vyžaduje velkou péči. Předkládaná brožura ukazuje půdní úrodnost z různých úhlů pohledu. Naším záměrem však nebylo vytvořit obecně platný „návod k použití“. Informace mají být mnohem spíše podnětem k tomu, aby se o vztahu člověka k půdě smýšlelo jinak a aby se tento vztah utvářel ve prospěch budoucnosti

    Grundlagen zur Bodenfruchtbarkeit - Die Beziehung zum Boden gestalten

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    Die Broschüre beleuchtet die Bodenfruchtbarkeit aus verschiedenen wissenschaftlichen und bäuerlichen Blickwinkeln. Die Informationen wollen praktische Beobachtungen der Landwirte ergänzen und dazu anregen, die Beziehung zum Boden zu überdenken und eine wirklich nachhaltige Bodenkultur zu praktizieren

    Radiolucent lines in low-contact-stress mobile-bearing total knee arthroplasty: a blinded and matched case control study

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    <p>Abstract</p> <p>Background</p> <p>Low-contact-stress (LCS) mobile-bearing total knee arthroplasty (TKA) (Johnson & Johnson, New Brunswick, NJ; previously: DePuy, Warsawa, USA) provides excellent functional results and wear rates in long-term follow-up analyses. Radiological analysis shows radiolucent lines (RLL) appearing immediately or two years after primary implantation, indicative of poor seat. Investigations proved RLL to be more frequent in uncemented TKA, resulting in a consensus to cement the tibial plateau, but their association with clinical findings and patients discomfort and knee pain is still unknown.</p> <p>Methods</p> <p>553 patients with 566 low-contact-stress (LCS) total knee prostheses were screened for continuous moderate knee pain. We compared tibial stress shielding classified by Ewald in patients suffering from pain with a matched, pain-free control group on blinded X-rays. We hypothesized a positive correlation between pain and radiolucency and higher frequency of such radiolucent lines in the most medial and most lateral zones of the tibial plateau.</p> <p>Results</p> <p>Twenty-eight patients suffered from knee pain in total. Radiolucencies were detected in 27 of these cases and in six out of 28 matched controls without knee pain. We could demonstrate a significant correlation of knee pain and radiolucencies, which appeared significantly more frequently in the outermost zones of the tibial plateau.</p> <p>Conclusion</p> <p>Our findings suggest that radiolucent lines, representing poor implant seat, about the tibial plateau are associated with knee pain in LCS patients. Radiolucencies are observed more often in noncemented LCS, and cementing the tibial plateau might improve implant seat and reduce both radiolucent lines and associated knee pain.</p

    The global naturalized Alien Flora (GloNAF) database

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    This dataset provides the Global Naturalized Alien Flora (GloNAF) database, ver-sion 1.2. Glo NAF represents a data compendium on th e occurrence and identit y of naturalizedalien vascular plant taxa across geographic regions (e.g. countries, states, provinces, districts,islands) around the globe. The dataset includes 13,939 taxa and covers 1,029 regions (including381 islands). The dataset is based on 210 data sources. For each ta x on-b y-region combination, wepr ovide information on whether the tax on is consider ed to be naturalized in the specific region(i.e. has established self-sustaining popula tions in the wild). Non-native taxa are marked as“alien”, when it is not clear whether they are naturalized. To facilitate alignment with other plantdatabases, we pro v ide f or each taxon the name as given in the original data source and the stan-dardized taxon and family names used by The Plant List Version 1.1 (http://www.theplantlist.org/). We pro vide an ESRI shapefile including polygons f or each region and informa tion on whetherit is an island or a mainland region, the country and the Taxonomic Databases Working Group(TDWG) regions it is part of (TDWG levels 1–4). We also provide several variables that can beused to filter the data according to quality and completeness of alien taxon lists, which varyamong the combinations of regions and da ta sources. A pre vious version of the GloNAF dataset(version 1.1) has already been used in several studies on, for example, historical spatial flows oftaxa between continents and geographical patterns and determinants of naturalization across dif-ferent taxonomic groups. We intend the updated and expanded GloNAF version presented hereto be a global resource useful for studying plant inv asions and changes in biodiversity from regio-nal to global scales. We release these data into the public domain under a Crea ti ve CommonsZer o license waiver (https://creati v ecommons.org/share-y our -work/public-domain/cc0/). Wheny ou use the da ta in your publication, we request that y ou cite this da ta paper. If GloN AF is amajor part of the data analyzed in your study, you should consider inviting the GloNAF coreteam (see Metadata S1: Originators in the Overall project description) as collaborators. If youplan to use the GloNAF dataset, we encourage y ou to contact the GloNAF core team to checkwhether there have been recent updates of the dataset, and whether similar analyses are already ongoing

    Herausforderung Inklusion: Schule - Unterricht - Profession

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    Das Übereinkommen der Vereinten Nationen über die Rechte von Menschen mit Behinderungen sowie das dazu gehörende Fakultativprotokoll zum Übereinkommen der Vereinten Nationen über die Rechte von Menschen mit Behinderungen trat am 26.03.2009 ohne Einschränkung als innerstaatliches deutsches Recht in Kraft. Sich mit diesen vielschichtigen Themenkomplexen auseinanderzusetzen war das Ziel der Tagung „Herausforderung Inklusion: Schule – Unterricht – Profession“, die am 27. und 28. März 2014 an der Otto-Friedrich-Universität in Bamberg stattfand und sowohl betroffene Eltern, als auch Praktikerinnen und Praktiker und Wissenschaftlerinnen und Wissenschaftler zur Diskussion einlud. Der vorliegende Band geht auf diese Tagung zurück und möchte die vielfältigen Facetten der theoretischen, konzeptuellen und didaktisch-methodischen Zugänge im Kontext der derzeit geführten Debatten und Argumentationsmuster um ein inklusives Bildungswesen abbilden und neue Perspektiven für Forschung, Disziplin und Profession anregen. Demzufolge liegt der Fokus der Beiträge zum einen auf der Auseinandersetzung mit theoretischen Zugängen zur Inklusion sowie der Diskussion von nationalen und internationalen empirischen Erkenntnissen aus Studien der Inklusionsforschung, zum anderen auf der Präsentation von inklusiven Konzepten einer Schulentwicklung, (fach)didaktisch-methodischen Überlegungen und Modellprojekten aus der Praxis

    Biological Earth observation with animal sensors

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    Space-based tracking technology using low-cost miniature tags is now delivering data on fine-scale animal movement at near-global scale. Linked with remotely sensed environmental data, this offers a biological lens on habitat integrity and connectivity for conservation and human health; a global network of animal sentinels of environmen-tal change
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