78 research outputs found
Dynamic surface completion : the joint formation of color, texture, and shape
Dynamic surface completion is a phenomenon of visual filling-in where a colored pattern perceptually spreads onto an area confined by virtual contours in a multi-aperture motion display. The spreading effect is qualitatively similar to static texture spreading but widely surpasses it in strength, making it particularly suited for quantitative studies of visual interpolation processes. I carried out six experiments to establish with objective tasks that homogeneous color, as well as non-uniform texture spreading is a genuine representation of surface qualities and thus goes beyond mere contour interpolation. The experiments also serve to relate the phenomena to ongoing discussions about potentially responsible mechanisms for spatiotemporal integration: With a phenomenological method, I examined to what extent simple sensory persistence might be causally involved in the effect under consideration. The findings are partially consistent with the idea of sensory persistence, and indicate that information fragments are integrated over a time window of about 100 to 150 ms to form a complete surface representation
Static Magnetic Proximity Effect in Pt Layers on Sputter-Deposited NiFe2O4 and on Fe of Various Thicknesses Investigated by XRMR
The longitudinal spin Seebeck effect is detected in sputter-deposited NiFe2O4
films using Pt as a spin detector and compared to previously investigated
NiFe2O4 films prepared by chemical vapor deposition. Anomalous Nernst effects
induced by the magnetic proximity effect in Pt can be excluded for the
sputter-deposited NiFe2O4 films down to a certain limit, since x-ray resonant
magnetic reflectivity measurements show no magnetic response down to a limit of
0.04 {\mu}B per Pt atom comparable to the case of the chemicallydeposited
NiFe2O4 films. These differently prepared films have various thicknesses.
Therefore, we further studied Pt/Fe reference samples with various Fe
thicknesses and could confirm that the magnetic proximity effect is only
induced by the interface properties of the magnetic material.Comment: 4 pages, 4 figure
Static magnetic proximity effect in Pt/NiFe2O4 and Pt/Fe bilayers investigated by x-ray resonant magnetic reflectivity
The spin polarization of Pt in Pt/NiFe2O4 and Pt/Fe bilayers is studied by
interface-sensitive x-ray resonant magnetic reflectivity to investigate static
magnetic proximity effects. The asymmetry ratio of the reflectivity was
measured at the Pt L3 absorption edge using circular polarized x-rays for
opposite directions of the magnetization at room temperature. The results of
the 2% asymmetry ratio for Pt/Fe bilayers are independent of the Pt thickness
between 1.8 and 20 nm. By comparison with ab initio calculations, the maximum
magnetic moment per spin polarized Pt atom at the interface is determined to be
for Pt/Fe. For Pt/NiFe2O4 the asymmetry ratio drops
below the sensitivity limit of per Pt atom. Therefore, we
conclude, that the longitudinal spin Seebeck effect recently observed in
Pt/NiFe2O4 is not influenced by a proximity induced anomalous Nernst effect.Comment: 5 pages, 5 figure
Sign change in the tunnel magnetoresistance of Fe3O4/MgO/Co-Fe-B magnetic tunnel junctions depending on the annealing temperature and the interface treatment
Magnetite (Fe3O4) is an eligible candidate for magnetic tunnel junctions
(MTJs) since it shows a high spin polarization at the Fermi level as well as a
high Curie temperature of 585{\deg}C. In this study, Fe3O4/MgO/Co-Fe-B MTJs
were manufactured. A sign change in the TMR is observed after annealing the
MTJs at temperatures between 200{\deg}C and 280{\deg}C. Our findings suggest an
Mg interdiffusion from the MgO barrier into the Fe3O4 as the reason for the
change of the TMR. Additionally, different treatments of the magnetite
interface (argon bombardment, annealing at 200{\deg}C in oxygen atmosphere)
during the preparation of the MTJs have been studied regarding their effect on
the performance of the MTJs. A maximum TMR of up to -12% could be observed
using both argon bombardment and annealing in oxygen atmosphere, despite
exposing the magnetite surface to atmospheric conditions before the deposition
of the MgO barrier.Comment: 5 pages, 5 figures, 2 table
Sign change in the tunnel magnetoresistance of Fe3O4/MgO/Co-Fe-B magnetic tunnel junctions depending on the annealing temperature and the interface treatment
Marnitz L, Rott K, Niehörster S, et al. Sign change in the tunnel magnetoresistance of Fe3O4/MgO/Co-Fe-B magnetic tunnel junctions depending on the annealing temperature and the interface treatment. AIP Advances. 2015;5(4): 047103.Magnetite (Fe3O4) is an eligible candidate for magnetic tunnel junctions (MTJs) since it shows a high spin polarization at the Fermi level as well as a high Curie temperature of 585°C. In this study, Fe3O4/MgO/Co-Fe-B MTJs were manufactured. A sign change in the TMR is observed after annealing the MTJs at temperatures between 200°C and 280°C. Our findings suggest an Mg interdiffusion from the MgO barrier into the Fe3O4 as the reason for the change of the TMR. Additionally, different treatments of the magnetite interface (argon bombardment, annealing at 200°C in oxygen atmosphere) during the preparation of the MTJs have been studied regarding their effect on the performance of the MTJs. A maximum TMR of up to -12% could be observed using both argon bombardment and annealing in oxygen atmosphere, despite exposing the magnetite surface to atmospheric conditions before the deposition of the MgO barrier
The Coastal Observing System for Northern and Arctic Seas (COSYNA)
The Coastal Observing System for Northern and Arctic Seas (COSYNA) was established in order to better understand the complex interdisciplinary processes of northern seas and the Arctic coasts in a changing environment. Particular focus is given to the German Bight in the North Sea as a prime example of a heavily used coastal area, and Svalbard as an example of an Arctic coast that is under strong pressure
due to global change. The COSYNA automated observing and modelling system is designed to monitor real-time conditions and provide short-term forecasts, data, and data products to help assess the impact of anthropogenically induced change. Observations are carried out by combining satellite and radar remote sensing with various in situ platforms. Novel sensors, instruments, and algorithms are developed to further improve the understanding of the interdisciplinary interactions between physics, biogeochemistry, and the ecology of coastal seas. New modelling and data assimilation techniques are used to integrate observations and models in a quasi-operational system providing descriptions and forecasts of key hydrographic variables. Data and data products are publicly available free of charge and in real time. They are used by multiple interest
groups in science, agencies, politics, industry, and the public
Berufliche Stabilitäts- und Flexibilitätsorientierungen in Ostdeutschland: Ergebnisse eines Forschungspraktikums
Das im folgenden vorgestellte Projekt Stabilitäts- und Flexibilitätsorientierungen in ostdeutschen Lebensverläufen wurde am Institut für Soziologie der Universität Leipzig im Rahmen eines Lehrpraktikums durchgeführt. In dem Projekt wurden berufliche Stabilitäts- und Flexibilitätsorientierungen ostdeutscher Beschäftigter vor dem Hintergrund individueller Ressourcen und Gelegenheitsstrukturen untersucht. Anhand von 68 biographischen Interviews älterer und jüngerer Kohorten sollte gezeigt werden, in welchem Maße individuelle Merkmale sowie familiäre, arbeitsmarktliche, sozialpolitische und betriebliche Gelegenheitsstrukturen die individuellen Handlungsorientierungen beeinflussen. Vor dem Hintergrund der \"Entstandardisierung\" von Lebenslaufmustern und der \"Flexibilisierung\" von Erwerbsverläufen wurde dabei nach den Ursachen und Veränderungen kohortenspezifischer Unterscheidungen berufsbiographischer Entwürfe gefragt.:Vorbemerkung; Stabilität und Flexibilität im Lebensverlauf; Analytisches Modell und methodisches Vorgehen; Ergebnisse; Bewältigungsstrategien – Eine Zusammenfassung; Literatur, Anhan
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