15,090 research outputs found

    Graphene-WS2_2 heterostructures for tunable spin injection and spin transport

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    We report the first measurements of spin injection in to graphene through a 20 nm thick tungsten disulphide (WS2_2) layer, along with a modified spin relaxation time ({\tau}s) in graphene in the WS2_2 environment, via spin-valve and Hanle spin-precession measurements, respectively. First, during the spin-injection into graphene through a WS2_2-graphene interface, we can tune the interface resistance at different current bias and modify the spin injection efficiency, in a correlation with the conductivity-mismatch theory. Temperature assisted tunneling is identified as a dominant mechanism for the charge transport across the interface. Second, we measure the spin transport in graphene, underneath the WS2_2 crystal and observe a significant reduction in the {\tau}s down to 17 ps in graphene in the WS2_2 covered region, compared to that in its pristine state. The reduced {\tau}s indicates the WS2_2-proximity induced additional dephasing of the spins in graphene.Comment: 7 Pages, 6 figure

    Support for farmers' cooperatives: EU synthesis and comparative analysis report: policy measures

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    In order to foster the competitiveness of the food supply chain, the European Commission is committed to promote and facilitate the restructuring and consolidation of the agricultural sector by encouraging the creation of voluntary agricultural producer organisations. To support the policy making process DG Agriculture and Rural Development has launched a large study, “Support for Farmers’ Cooperatives (SFC)”, that will provide insights on successful cooperatives and producer organisations as well as on effective support measures for these organisations. These insights can be used by farmers themselves, in setting up and strengthening their collective organisation, and by the European Commission in its effort to encourage the creation of agricultural producer organisations in the EU. Within the framework of the SFC project this EU synthesis and comparative analysis report - Policy Measures has been written. Data collection for this report has been done in the summer of 2011. In addition to this report, the SFC-project has delivered 27 country reports, a report on policies for cooperatives in non-EU OECD countries, 8 sector reports, 5 other EU synthesis and comparative analysis reports, 33 case studies, a report on cluster analysis, and a final report

    Traces of prior art. An analysis of non-patent references found in patent documents.

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    Research in the area of innovation has pointed out the relevance of conceiving innovation as processes in which a multitude of actors and a variety of interactions play a role. Integrative notions like (national) innovations systems, (techno-scientific) networks, or the triple helix metaphor, have been widely accepted as relevant to grasp the complexities entailed. This development highlights the need for indicators that mirror the dynamics involved. This contribution presents an in-depth examination of the role of 'Non-Patent references', found in patents. After examining the occurrence of these references in the USPTO and EPO patent systems, the precise nature of these references is delineated by means of a systematic content analysis of two samples of non-patent references (n=10.000). Our observations reveal the relevance of 'non-patent references' for developing indicators to depict the proximity of technological and scientific developments. Application areas, limitations and directions for future research are discussed.Academic investors; Field; Industry; Knowledge; Knowlegde interactions; Research; University-industry relations; Working; Area; Innovation; Processes; Innovations; Systems; Networks; Triple-helix; Complexity; Indicators; Dynamics; Patents;

    An inverse dynamics model for the analysis, reconstruction and prediction of bipedal walking

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    Walking is a constrained movement which may best be observed during the double stance phase when both feet contact the floor. When analyzing a measured movement with an inverse dynamics model, a violation of these constrains will always occur due to measuring errors and deviations of the segments model from reality, leading to inconsistent results. Consistency is obtained by implementing the constraints into the model. This makes it possible to combine the inverse dynamics model with optimization techniques in order to predict walking patterns or to reconstruct non-measured rotations when only a part of the three-dimensional joint rotations is measured. In this paper the outlines of the extended inverse dynamics method are presented, the constraints which define walking are defined and the optimization procedure is described. The model is applied to analyze a normal walking pattern of which only the hip, knee and ankle flexions/extensions are measured. This input movement is reconstructed to a kinematically and dynamically consistent three-dimensional movement, and the joint forces (including the ground reaction forces) and joint moments of force, needed to bring about this movement are estimated

    Mine and Thine: The Territorial Foundations of Human Property

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    Research shows that many animal species have morphological and cognitive adaptations for fighting with others to gain resources, but it remains unclear how humans make fighting decisions. Non-human animals often adaptively calibrate fighting behavior to ecological variables such as resource quantity and whether the resource is distributed uniformly or clustered in patches. Also, many species use strategies to reduce fighting costs such as resolving disputes based on power asymmetries or conventions. Here we show that humans apply an ownership convention in response to the problem of severe fighting. We designed a virtual environment where ten participants, acting as avatars, could forage and fight for electronic food items (convertible to cash). In the patchy condition, we observed an ownership convention—the avatar who arrives first is more likely to win—but in the uniform condition, where severe fighting is rare, the ownership convention is absent.
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