355 research outputs found

    Smart Institutions for Smart Cities

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    Smart cities employ creativity of the population for innovations supporting social and economic development. In this context, this paper explores the role of framework conditions on special supply effects of university hospitals, which can invite further research institutions for intense collaboration, thereby stimulating innovations. The case study, comparing a hospital in Russia with one in Germany, is based on the concept of the employment multiplier. The results show that exogenously given, but, more importantly, also modifiable framework conditions lead to large differences regarding the employment multiplier. Thus, it should be the concern of smart cities to make smart use of their institutions, such as university hospitals, by adjusting the conditions, under which they are operating. © 2018 Institute of Physics Publishing. All rights reserved

    Flexibles Lernen: Erfolgreiche online-gestützte Lernprozesse ermöglichen

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    Die Digitalisierung im Gesundheitswesen erfordert eine kontinuierliche Weiterqualifikation der betroffenen Berufsgruppen. Die Universität UMIT hat daher 2017 einen online-gestützten, postgraduellen Universitätslehrgang gestartet. Beim didaktischen Design lag ein Schwerpunkt auf der Flexibilität des Lernens, um so den Anforderungen der berufstätigen Teilnehmer/innen besonders zu entsprechen. Dabei wurde neben Flexibilität von Ort und Zeit des Lernens auch Flexibilität z. B. beim Setzen eigener Lernziele und bei Lerninhalten ermöglicht. Wir stellen das gewählte didaktische Design vor und beleuchten auf Basis einer Analyse von Log-Daten, studentischer Evaluationen sowie studentischer Reflexionen die Akzeptanz sowie die Herausforderungen des flexiblen Lernens aus Sicht der Lernenden

    Nernst effect of iron pnictide and cuprate superconductors: signatures of spin density wave and stripe order

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    The Nernst effect has recently proven a sensitive probe for detecting unusual normal state properties of unconventional superconductors. In particular, it may sensitively detect Fermi surface reconstructions which are connected to a charge or spin density wave (SDW) ordered state, and even fluctuating forms of such a state. Here we summarize recent results for the Nernst effect of the iron pnictide superconductor LaO1xFxFeAs\rm LaO_{1-x}F_xFeAs, whose ground state evolves upon doping from an itinerant SDW to a superconducting state, and the cuprate superconductor La1.8xEu0.2SrxCuO4\rm La_{1.8-x}Eu_{0.2}Sr_xCuO_4 which exhibits static stripe order as a ground state competing with the superconductivity. In LaO1xFxFeAs\rm LaO_{1-x}F_xFeAs, the SDW order leads to a huge Nernst response, which allows to detect even fluctuating SDW precursors at superconducting doping levels where long range SDW order is suppressed. This is in contrast to the impact of stripe order on the normal state Nernst effect in La1.8xEu0.2SrxCuO4\rm La_{1.8-x}Eu_{0.2}Sr_xCuO_4. Here, though signatures of the stripe order are detectable in the temperature dependence of the Nernst coefficient, its overall temperature dependence is very similar to that of La2xSrxCuO4\rm La_{2-x}Sr_xCuO_4, where stripe order is absent. The anomalies which are induced by the stripe order are very subtle and the enhancement of the Nernst response due to static stripe order in La1.8xEu0.2SrxCuO4\rm La_{1.8-x}Eu_{0.2}Sr_xCuO_4 as compared to that of the pseudogap phase in La2xSrxCuO4\rm La_{2-x}Sr_xCuO_4, if any, is very small.Comment: To appear in: 'Properties and applications of thermoelectric materials - II', V. Zlatic and A. Hewson, editors, Proceedings of NATO Advanced Research Workshop, Hvar, Croatia, September 19 -25, 2011, NATO Science for Peace and Security Series B: Physics and Biophysics, (Springer Science+Business Media B.V. 2012

    Indikatoren für kooperative, online-basierte Lernprozesse: Entwicklung und Erprobung

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    Lernen als konstruktiver und sozialer Prozess funktioniert am besten in Interaktion mit anderen Personen. Insbesondere in online-basierten Lernsettings sind Interaktion und Kooperation der Studierenden ein wichtiger Faktor für erfolgreiches Lernen. In dieser Arbeit schlagen wir zunächst Indikatoren für das Monitoring der Aktivität und Interaktivität von Studierenden sowie Lehrenden in kooperativen online-basierten Lernsettings vor. In einer Fallstudie werden die Indikatoren dann am Beispiel von drei Online-Kursen eingesetzt. Die Ergebnisse zeigen, dass die Indikatoren wichtige Aufschlüsse über die Aktivität und Interaktivität der Studierenden liefern können. Ergänzt um Daten zur Arbeitsbelastung, um Prüfungsergebnisse und um Lehrevaluierungen können auch Aussagen zur Qualität der Lernprozesse und zum Lernerfolg gemacht werden

    Nernst Effect of stripe ordering La1.8x_{1.8-x}Eu0.2_{0.2}Srx_xCuO4_4

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    We investigate the transport properties of La1.8x_{1.8-x}Eu0.2_{0.2}Srx_xCuO4_4 (x=0.04x=0.04, 0.08, 0.125, 0.15, 0.2) with a special focus on the Nernst effect in the normal state. Various anomalous features are present in the data. For x=0.125x=0.125 and 0.15 a kink-like anomaly is present in the vicinity of the onset of charge stripe order in the LTT phase, suggestive of enhanced positive quasiparticle Nernst response in the stripe ordered phase. At higher temperature, all doping levels except x=0.2x=0.2 exhibit a further kink anomaly in the LTO phase which cannot unambiguously be related to stripe order. Moreover, a direct comparison between the Nernst coefficients of stripe ordering La1.8x_{1.8-x}Eu0.2_{0.2}Srx_xCuO4_4 and superconducting La2x_{2-x}Srx_xCuO4_4 at the doping levels x=0.125x=0.125 and x=0.15x=0.15 reveals only weak differences. Our findings make high demands on any scenario interpreting the Nernst response in hole-doped cuprates

    Weak and strong electronic correlations in Fe superconductors

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    In this chapter the strength of electronic correlations in the normal phase of Fe-superconductors is discussed. It will be shown that the agreement between a wealth of experiments and DFT+DMFT or similar approaches supports a scenario in which strongly-correlated and weakly-correlated electrons coexist in the conduction bands of these materials. I will then reverse-engineer the realistic calculations and justify this scenario in terms of simpler behaviors easily interpreted through model results. All pieces come together to show that Hund's coupling, besides being responsible for the electronic correlations even in absence of a strong Coulomb repulsion is also the origin of a subtle emergent behavior: orbital decoupling. Indeed Hund's exchange decouples the charge excitations in the different Iron orbitals involved in the conduction bands thus causing an independent tuning of the degree of electronic correlation in each one of them. The latter becomes sensitive almost only to the offset of the orbital population from half-filling, where a Mott insulating state is invariably realized at these interaction strengths. Depending on the difference in orbital population a different 'Mottness' affects each orbital, and thus reflects in the conduction bands and in the Fermi surfaces depending on the orbital content.Comment: Book Chapte

    Electronic Raman scattering in YBCO and other superconducting cuprates

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    Superconductivity induced structures in the electronic Raman spectra of high-Tc superconductors are computed using the results of ab initio LDA-LMTO three-dimensional band structure calculations via numerical integrations of the mass fluctuations, either in the whole 3D Brillouin zone or limiting the integrations to the Fermi surface. The results of both calculations are rather similar, the Brillouin zone integration yielding additional weak structures related to the extended van Hove singularities. Similar calculations have been performed for the normal state of these high-Tc cuprates. Polarization configurations have been investigated and the results have been compared to experimental spectra. The assumption of a simple d_(x^2-y^2)-like gap function allows us to explain a number of experimental features but is hard to reconcile with the relative positions of the A1g and B1g peaks.Comment: 14 pages, LaTeX (RevTeX), 5 PostScript figures, uses multicol.sty, submitted to PR

    Evidence for Magnetic Pseudoscaling in Overdoped La(2-x)Sr(x)CuO(4)

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    We report the results of electronic Raman scattering experiments on an overdoped La(1.78)Sr(0.22)CuO(4) single crystal as a function of temperature. The scattering rate Gamma(w->0,T) has been determined from the normal state B(1g) spectra in the range 50 K < T < 300 K. Gamma(T) decreases linearly from 300 K to about 175 K and then undergoes a reduction with respect to the expected mean-field behavior. This trend suggests a crossover to pseudoscaling regime at about T(cr)=160 K. The results are in good agreement with the prediction of the nearly antiferromagnetic Fermi liquid model. There is no evidence of a pseudogap in the spectra obtained from this overdoped sample.Comment: RevTex, 4 pages with 3 PS figures included, replaced with minor changes in the text and reference
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