46 research outputs found

    Simultaneous PIXE and RBS data analysis using Bayesian Inference with the DataFurnace code

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    The Rutherford Backscattering Spectroscopy (RBS) and Particle Induced X-ray Emission (PIXE) techniques can be used to obtain complementary information about the characteristics of a sample but, traditionally, a gap has separated the available computer codes for analyzing data from each technique, being hard to simultaneously analyze data from the same sample. The recent development of a free and open source library, LibCPIXE, for PIXE simulation and analysis of arbitrary multilayered samples, has permitted to integrate this technique into the DataFurnace code which already handles many other IBA techniques such as Rutherford and non-Rutherford backscattering, elastic recoil detection, and non-resonant nuclear reaction analysis. The fitting capabilities of DataFurnace can therefore now be applied to PIXE spectra as well, including the Bayesian Inference analysis and the simultaneous and coherent fitting of multiple spectra from different techniques. Various examples are presented in which the simultaneous RBS and PIXE analysis allows us to obtain consistent results that cannot be obtained by independent analysis of the data from each technique.Comment: 10 pages, 5 figures. Paper initially presented to IBA2005. Please cite the published version (DOI:10.1016/j.nimb.2006.03.190

    LibCPIXE: a PIXE simulation open-source library for multilayered samples

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    Most particle induced X-ray emission (PIXE) data analysis codes are not focused on handling multilayered samples. We have developed an open-source library called "LibCPIXE", for PIXE data analysis. It is written in standard C and implements functions for simulating X-ray yields of PIXE spectra taken from arbitrary samples, including multilayered targets. The library is designed to be fast, portable, modular and scalable, as well as to facilitate its incorporation into any existing program. In order to demonstrate the capabilities of the library, a program called CPIXE was developed and used to analyze various real samples involving both bulk and layered samples. Just as the library, the CPIXE source code is freely available under the General Public License. We demonstrate that it runs both under GNU/Linux systems as well as under MS Windows. There is in principle no limitation to port it to other platforms

    Smoking and plasma fibrinogen, lipoprotein (a) and serotinin are markers for postoperative infrainguinal graft stenosis

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    Objectives:A number of systemic variables are associated with infrainguinal graft failure and also with experimental smooth muscle hyperplasia. Stenosis is the most common cause of infrainguinal graft thrombosis but it is not known if systemic variables are associated with stenosis.Design, materials and methods:In this study, clinical and serological factors were measured and correlated with stenosis development in 81 infrainguinal bypass grafts (52 vein, 29 PTFE; 28 with stenosis) in prospective (n = 46) and retrospective (n = 35) groups. Pre-existing stenosis was ecluded by perioperative graft assessment.Results:There was a significantly greater proportion of smokers in the patients who developed stenosis (11/18; 61%) compared with those who did not (6/28; 21%, p = 0.006; x2). Patients who developed stenosis also had significantly (Mann Whitney U-tests), higher circulating levels of [median (interquartile range)] fibrinogen (412.5 (356–484.5) vs. 339 (300–397.7) mg/100ml, p = 0.003), Lipoprotein (a) (0.20 (0.05–0.45) vs. 0.085 (0.05–0.23), g/l, p = 0.03) and 5-hydroxytryptamine (14.1 (6.6–45) vs. 4.41 (3–8.39) nmol/l, p = 0.005), than those without stenosis.By logistic regression, these associations were independent of graft material and whether grafts were studied prospectively or retrospectively.Conclusions:Smoking and plasma fibrinogen, Lp(a) and 5-hydroxytryptamine are markers for postoperative infrainguinal graft stenosis

    Composition measurement of epitaxial Sc<inf>x</inf>Ga<inf>1-x</inf>N films

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    Four different methods for measuring the compositions of epitaxial ScxGa1-xN films were assessed and compared to determine which was the most reliable and accurate. The compositions of epitaxial ScxGa1-xN films with 0 ≤ x ≤ 0.26 were measured directly using Rutherford backscattering (RBS) and x-ray photoelectron spectroscopy (XPS), and indirectly using c lattice parameter measurements from x-ray diffraction and c/a ratio measurements from electron diffraction patterns. RBS measurements were taken as a standard reference. XPS was found to underestimate the Sc content, whereas c lattice parameter and c/a ratio were not reliable for composition determination due to the unknown degree of strain relaxation in the film. However, the Sc flux used during growth was found to relate linearly with x and could be used to estimate the Sc content

    H^+ -> W^+ l_i^- l_j^+$ decay in the two Higgs doublet model

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    We study the lepton flavor violating H^+ -> W^+ l_i^- l_j^+ and the lepton flavor conserving $H^+ -> W^+ l_i^- l_i^+ (l_i=\tau, l_j=\mu) decays in the general 2HDM, so called model III. We estimate the decay width \Gamma for LFV (LFC) at the order of the magnitude of (10^{-11}-10^{-5}) GeV ((10^{-9}-10^{-4}) GeV), for 200 GeV\leq m_{H^\pm}\leq 400 GeV, and the intermediate values of the coupling \bar{\xi}^{E}_{N,\tau \mu}\sim 5 GeV (\bar{\xi}^{E}_{N,\tau \tau}\sim 30 GeV). We observe that the experimental result of the process under consideration can give comprehensive information about the physics beyond the standard model and the existing free parameters.Comment: 8 pages, 7 Figure

    Effects of Intermittent IL-2 Alone or with Peri-Cycle Antiretroviral Therapy in Early HIV Infection: The STALWART Study

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    The Study of Aldesleukin with and without antiretroviral therapy (STALWART) evaluated whether intermittent interleukin-2 (IL-2) alone or with antiretroviral therapy (ART) around IL-2 cycles increased CD4+ counts compared to no therapy

    Use of SMS texts for facilitating access to online alcohol interventions: a feasibility study

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    A41 Use of SMS texts for facilitating access to online alcohol interventions: a feasibility study In: Addiction Science & Clinical Practice 2017, 12(Suppl 1): A4
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