6,555 research outputs found

    Novel sputtering-technology for grain-size control

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    In this paper, we present a description of a novel high-rate plasma sputtering system that allows the control of grain size in sputtered films. Additionally, the system has the advantage of a better utilization of the target material (around 80% to 90%) by eliminating the race track at the target as in conventional plasma magnetron sputtering systems. The potential and capabilities of this novel plasma sputtering device are demonstrated in this paper by the deposition of a number of different Cr thin films suitable for underlayers in thin-film media and for which we have performed a systematic X-ray and TEM analysis to determine the grain-size histograms, mean grain diameters, and their relationship to the sputtering processes

    Growth rate effects in soft CoFe films

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    We report on growth rate effects in sputter-deposited CoFe films prepared using high target utilization sputtering technology (HiTUS). We find that the grain structure of these polycrystalline films is closely related to the growth rate. By changing the growth rate, samples were prepared with different grain structure, which in turn had the effect of changing the magnetic properties of the films. We demonstrate control of the coercivity, which varied by a factor of more than ten. This was achieved via grain size control in CoFe films of thickness 20 nm. Furthermore, by employing a two-step sputtering process, in which two extreme growth rates are used sequentially, we were able to tune the saturation magnetization

    Dividend-Protected Convertible Bonds and the Disappearance

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    The Spectrum of Pluto, 0.40 - 0.93 μ\mum I. Secular and longitudinal distribution of ices and complex organics

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    Context. During the last 30 years the surface of Pluto has been characterized, and its variability has been monitored, through continuous near-infrared spectroscopic observations. But in the visible range only few data are available. Aims. The aim of this work is to define the Pluto's relative reflectance in the visible range to characterize the different components of its surface, and to provide ground based observations in support of the New Horizons mission. Methods. We observed Pluto on six nights between May and July 2014, with the imager/spectrograph ACAM at the William Herschel Telescope (La Palma, Spain). The six spectra obtained cover a whole rotation of Pluto (Prot = 6.4 days). For all the spectra we computed the spectral slope and the depth of the absorption bands of methane ice between 0.62 and 0.90 μ\mum. To search for shifts of the center of the methane bands, associated with dilution of CH4 in N2, we compared the bands with reflectances of pure methane ice. Results. All the new spectra show the methane ice absorption bands between 0.62 and 0.90 μ\mum. The computation of the depth of the band at 0.62 μ\mum in the new spectra of Pluto, and in the spectra of Makemake and Eris from the literature, allowed us to estimate the Lambert coefficient at this wavelength, at a temperature of 30 K and 40 K, never measured before. All the detected bands are blue shifted, with minimum shifts in correspondence with the regions where the abundance of methane is higher. This could be indicative of a dilution of CH4:N2 more saturated in CH4. The longitudinal and secular variations of the parameters measured in the spectra are in accordance with results previously reported in the literature and with the distribution of the dark and bright material that show the Pluto's albedo maps from New Horizons.Comment: This manuscript may change and improve during the reviewing process. The data reduction and calibration is reliable and has been checked independently using different reduction approaches. The data will be made publicily available when the paper is accepted. If you need them before, please, contact the autho

    Transition state theory and the dynamics of hard disks

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    The dynamics of two and five disk systems confined in a square has been studied using molecular dynamics simulations and compared with the predictions of transition state theory. We determine the partition functions Z and Z^\ddagger of transition state theory using a procedure first used by Salsburg and Wood for the pressure. Our simulations show this procedure and transition state theory are in excellent agreement with the simulations. A generalization of the transition state theory to the case of a large number of disks N is made and shown to be in full agreement with simulations of disks moving in a narrow channel. The same procedure for hard spheres in three dimensions leads to the Vogel-Fulcher-Tammann formula for their alpha relaxation time.Comment: 1 new author, new simulations and figures, less speculation. Now 6 pages, 6 figures, 1 animation. Animation may be viewed at http://www.theory.physics.manchester.ac.uk/~godfrey/supplement/activated_dynamics2.htm

    Demand for wool by grade

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    The aims of the project were to examine the relationships between auction prices of different types of wool, to identify categories of wool and to investigate substitution effects amongst wools. A modelling framework was developed which enabled these relationships to be analysed. While there are some clear avenues for further research, this study makes some useful first steps towards a conceptualisation of wool markets

    The structure of human CD23 and its interactions with IgE and CD21

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    The low-affinity immunoglobulin E (IgE) receptor, CD23 (FcɛRII), binds both IgE and CD21 and, through these interactions, regulates the synthesis of IgE, the antibody isotype that mediates the allergic response. We have determined the three-dimensional structure of the C-type lectin domain of CD23 in solution by nuclear magnetic resonance spectroscopy. An analysis of concentration-dependent chemical shift perturbations have allowed us to identify the residues engaged in self-association to the trimeric state, whereas ligand-induced changes have defined the binding sites for IgE and CD21. The results further reveal that CD23 can bind both ligands simultaneously. Despite the C-type lectin domain structure, none of the interactions require calcium. We also find that IgE and CD23 can interact to form high molecular mass multimeric complexes. The interactions that we have described provide a solution to the paradox that CD23 is involved in both up- and down-regulation of IgE and provide a structural basis for the development of inhibitors of allergic disease

    Influence of trust in institutions on public acceptance of nuclear power from a historical context across nuclear countries

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    Several studies have tried to determine what is behind peoples’ attitudes to different energy sources and their overall rather negative opinion on nuclear power. The issue of public perception of nuclear power has been going on for decades. Recently it gained even greater interest thanks to the support of the UK governmental nuclear industrial strategy to promote and support nuclear growth. Nuclear power is negatively influenced by events from the past such as nuclear accidents and connection of nuclear power with cold war and the use of nuclear bombs. As one of many other factors, the level of trust in authorities is perceived to influence the opposition or support for nuclear power. This study aims at analyzing data on trust in four main institutions (government, businesses, media and non-governmental organizations) from a historical perspective in several nuclear countries and finding evidence for relationship between trust in authorities and support for nuclear power. Structural Equation Modelling and Multiple Regression Analysis have been used to analyze data Structural Equation modelling requires a large sample set to provide meaningful results, therefore performance can deteriorate when sample size reduces. Hence, Multiple Regression analysis has been carried out. Results from Multiple Regression analysis did not prove that the trust in institutions is significant predictor of support for nuclear power. Although around 55% of variance in support for nuclear was explained by trust institutions in UK as well as in USA case. Large sample size is required to authenticate model and obtain more robust results. It is likely that Multiple Regression analysis will be used for future data analyses when more data will be available
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