233 research outputs found

    Atomic resolution force microscopy imaging on a strongly ionic surface with differently functionalized tips

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    金沢大学理工研究域数物科学系Three types of tips for noncontact atomic force microscopy imaging, namely, a silicon nanopillar tip, a carbon nanopillar tip, and a fluoride cluster tip, are prepared for atomic resolution imaging on the CaF2 (111) surface. The most enhanced atomic corrugation is obtained with the fluoride cluster tip prepared by gently touching the fluorite surface. Atom resolved images are much harder to obtain with the other tips. This demonstrates the importance of having a polar tip for atomic resolution imaging of an ionic surface and supports the general notion that a surface is best imaged with a tip of the same material. © 2010 American Vacuum Society

    Technology experience café - enabling technology - driven social innovation for an ageing society

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    Effective technology innovation process management in the context of active healthy ageing has the potential to improve older adults’ quality of life, allowing them to maintain their independence and age in their own homes for longer. But as older adults significantly differ from the general population in technology use and its impact on their quality of life, tools are needed that (1) involve this target group into the innovation process, as well as (2) capture the diverse needs of technology for various stakeholders involved in this process. This paper presents the framework called Technology Experience Café (TEC), developed within the European project SIforAGE, answering exactly this need. Detailed information on the methodology and its implementation in five sites, in four different countries across Europe, focusing on participating stakeholders, general design of the TEC, and used evaluation tools, is provided. Preliminary results show, that (1) the target group’s perception of the TEC as a framework was thoroughly positive and TECs had a positive impact on older adults’ technology related attitudes and (2) that stakeholders’ benefits affiliated with their involvement in the TECs are manifold. Implications and limitations are discussed

    The unusual electronic structure of the "pseudo-ladder" compound CaCu2O3

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    Experimental and theoretical studies of the unoccupied electronic structure of CaCu2O3 single crystals have been performed using polarization-dependent x-ray absorption spectroscopy and band structure calculations. The measured hole distribution shows an unusual large number of holes in orbitals parallel to the interlayer direction which is in agreement with the theoretical analysis. CaCu2O3 deviates significantly from the standard pd-sigma cuprate picture. The corresponding strong interlayer exchange is responsible for the missing spin gap generic for other two-leg ladder cuprates.Comment: 4 pages, 3 figures include

    Racemic 1,2,3,4,7,8,9,10-octa­fluoro-6H,12H-5,11-methano­dibenzo[b,f][1,5]diazo­cine: an octa­fluorinated analogue of Tröger’s base

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    The title compound, C15H6F8N2, possesses a non-crystal­lographic twofold axis. The dihedral angle between the two benzene rings is 98.4 (2)°. The crystal structure involves intermolecular C—H⋯F hydrogen bonds

    Evidence for short range orbital order in paramagnetic insulating (Al,V)_2O_3

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    The local structure of (Al_0.06V_0.94)_2O_3 in the paramagnetic insulating (PI) and antiferromagnetically ordered insulating (AFI) phase has been investigated using hard and soft x-ray absorption techniques. It is shown that: 1) on a local scale, the symmetry of the vanadium sites in both the PI and the AFI phase is the same; and 2) the vanadium 3d - oxygen 2p hybridization, as gauged by the oxygen 1s absorption edge, is the same for both phases, but distinctly different from the paramagnetic metallic phase of pure V_2O_3. These findings can be understood in the context of a recently proposed model which relates the long range monoclinic distortion of the antiferromagnetically ordered state to orbital ordering, if orbital short range order in the PI phase is assumed. The measured anisotropy of the x-ray absorption spectra is discussed in relation to spin-polarized density functional calculations.Comment: 8 pages, 5 figure

    Validity of the Polar V800 heart rate monitor to measure RR intervals at rest

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    Purpose To assess the validity of RR intervals and short-term heart rate variability (HRV) data obtained from the Polar V800 heart rate monitor, in comparison to an electrocardiograph (ECG). Method Twenty participants completed an active orthostatic test using the V800 and ECG. An improved method for the identification and correction of RR intervals was employed prior to HRV analysis. Agreement of the data was assessed using intra-class correlation coefficients (ICC), Bland–Altman limits of agreement (LoA), and effect size (ES). Results A small number of errors were detected between ECG and Polar RR signal, with a combined error rate of 0.086 %. The RR intervals from ECG to V800 were significantly different, but with small ES for both supine corrected and standing corrected data (ES 0.999 for both supine and standing corrected intervals. When analysed with the same HRV software no significant differences were observed in any HRV parameters, for either supine or standing; the data displayed small bias and tight LoA, strong ICC (>0.99) and small ES (≤0.029). Conclusions The V800 improves over previous Polar models, with narrower LoA, stronger ICC and smaller ES for both the RR intervals and HRV parameters. The findings support the validity of the Polar V800 and its ability to produce RR interval recordings consistent with an ECG. In addition, HRV parameters derived from these recordings are also highly comparable

    The surface science of quasicrystals

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    The surfaces of quasicrystals have been extensively studied since about 1990. In this paper we review work on the structure and morphology of clean surfaces, and their electronic and phonon structure. We also describe progress in adsorption and epitaxy studies. The paper is illustrated throughout with examples from the literature. We offer some reflections on the wider impact of this body of work and anticipate areas for future development. (Some figures in this article are in colour only in the electronic version

    Structure of metal site in azurin, met 121 mutants of azurin, and stellacyanin investigated by 111m Cd Perturbed Angular Correlation (PAC)

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    The geometries of the metal sites in cadmium-substituted azurins have been investigated by Cd-111m perturbed angular correlation (PAC), The study includes wild type azurin as well as Met(121) mutants of azurin, where methionine has been substituted by Ala, Asn, Asp, Gin, Glu, and Leu.The nuclear quadrupole interaction of wild type azurin analyzed in the angular overlap model is well described as coordination of His(46), His(117), and Cys(112) and cannot be described by coordination of Met(121) and/or Gly(45).For most of the mutants, there exist two coordination geometries of the cadmium ion, With the exception of the Gau and Asp mutants, one of the conformations is similar to the wild type conformation. The other coordination geometries are either best described by a coordinating water molecule close to the original methionine position or by coordination by the substituting amino acid, These experiments show that even though the methionine does not coordinate it plays an important role for the geometry of the metal site.The nuclear quadrupole interaction of stellacyanin was also measured, The value resembles the most prominent nuclear quadrupole interaction of the Met(121) --> Gin mutant of Alcaligenes denitrificans azurin, indicating that the structures of the two metal sites are similar.Macromolecular Biochemistr
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