1,821 research outputs found

    Quasi-free Standing Epitaxial Graphene on SiC by Hydrogen Intercalation

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    Quasi-free standing epitaxial graphene is obtained on SiC(0001) by hydrogen intercalation. The hydrogen moves between the 6root3 reconstructed initial carbon layer and the SiC substrate. The topmost Si atoms which for epitaxial graphene are covalently bound to this buffer layer, are now saturated by hydrogen bonds. The buffer layer is turned into a quasi-free standing graphene monolayer with its typical linear pi-bands. Similarly, epitaxial monolayer graphene turns into a decoupled bilayer. The intercalation is stable in air and can be reversed by annealing to around 900 degrees Celsius.Comment: Accepted for publication in Physical Review Letter

    A singularity free analytical solution of artificial satellite motion with drag

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    The connection between the existing Delaunay-Similar and Poincare-Similar satellite theories in the true anomaly version is outlined for the J(2) perturbation and the new drag approach. An overall description of the concept of the approach is given while the necessary expansions and the procedure to arrive at the computer program for the canonical forces is delineated. The procedure for the analytical integration of these developed equations is described. In addition, some numerical results are given. The computer program for the algebraic multiplication of the Fourier series which creates the FORTRAN coding in an automatic manner is described and documented

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    Auto Insurance Regulation

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    The method of averages applied to the KS differential equations

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    A new approach for the solution of artificial satellite trajectory problems is proposed. The basic idea is to apply an analytical solution method (the method of averages) to an appropriate formulation of the orbital mechanics equations of motion (the KS-element differential equations). The result is a set of transformed equations of motion that are more amenable to numerical solution

    Integrated watershed planning for freshwater sustainability on Salt Spring Island, BC, Canada

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    Island freshwater ecosystems in the Salish Sea have unique challenges. Fractured bedrock aquifers, limited surface water resources, and saltwater intrusion into groundwater systems require best management practices for freshwater sustainability. Salt Spring Island is the largest Canadian Gulf Island in the Salish Sea. With a population of 10,000 residents that triples in the summer, Salt Spring Island’s water resources are under great stress. However, through the creation of the multi-lateral Salt Spring Island Watershed Protection Authority (SSIWPA), the island is now positioned to create one of the first Water Sustainability Plans in British Columbia under the new Water Sustainability Act (2016). Islands Trust is the only local government in Canada with a legislated mandate to preserve and protect the environment. In 2013, Islands Trust created SSIWPA to coordinate with other government bodies in a collaborative framework - integrating watershed planning and policy development across jurisdictions. SSIWPA includes a dynamic group of member agencies from local, regional, and provincial governments, each with distinct authority over freshwater management. SSIWPA works with citizen and government scientists to create groundwater well inventories, aquifer budgets, surface water reservoir analyses, and educational programs promoting water literacy and conservation. SSIWPA practices collaborative watershed governance. Using structured terms of reference, data sharing agreements, and transparent public meetings, agencies are collaborating to achieve effective resource management. This coordinated and holistic approach helps avoid duplication of effort while filling data gaps and leveraging pooled resources to address challenges to the carrying capacity of water resources across the island. SSIPWA’s collaborative governance is an ongoing process of committed engagement based on respect, trust, and diplomacy across multiple levels of government and communities. Such cooperation is essential to comprehensive, sustainable freshwater management – especially in the context of water-scarce island ecosystems in the Salish Sea

    Prediction of huge X-ray Faraday rotation at the Gd N_4,5 threshold

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    X-ray absorption spectra in a wide energy range around the 4d-4f excitation threshold of Gd were recorded by total electron yield from in-plane magnetized Gd metal films. Matching the experimental spectra to tabulated absorption data reveals unprecedented short light absorption lengths down to 3 nm. The associated real parts of the refractive index for circularly polarized light propagating parallel or antiparallel to the Gd magnetization, determined through the Kramers-Kronig transformation, correspond to a magneto-optical Faraday rotation of 0.7 degrees per atomic layer. This finding shall allow the study of magnetic structure and magnetization dynamics of lanthanide elements in nanosize systems and dilute alloys.Comment: 4 pages, 2 figures, final version resubmitted to Phys. Rev. B, Brief Reports. Minor change

    Artificial intelligence ethics by design:Evaluating public perception on the importance of ethical design principles of artificial intelligence

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    Despite the immense societal importance of ethically designing artificial intelligence (AI), little research on the public perceptions of ethical AI principles exists. This becomes even more striking when considering that ethical AI development has the aim to be human-centric and of benefit for the whole society. In this study, we investigate how ethical principles (explainability, fairness, security, accountability, accuracy, privacy, machine autonomy) are weighted in comparison to each other. This is especially important, since simultaneously considering ethical principles is not only costly, but sometimes even impossible, as developers must make specific trade-off decisions. In this paper, we give first answers on the relative importance of ethical principles given a specific use case - the use of AI in tax fraud detection. The results of a large conjoint survey (n=1099) suggest that, by and large, German respondents found the ethical principles equally important. However, subsequent cluster analysis shows that different preference models for ethically designed systems exist among the German population. These clusters substantially differ not only in the preferred attributes, but also in the importance level of the attributes themselves. We further describe how these groups are constituted in terms of sociodemographics as well as opinions on AI. Societal implications as well as design challenges are discussed
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