2,126 research outputs found

    Hadron Spectroscopy with COMPASS at CERN

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    The aim of the COMPASS hadron programme is to study the light-quark hadron spectrum, and in particular, to search for evidence of hybrids and glueballs. COMPASS is a fixed-target experiment at the CERN SPS and features a two-stage spectrometer with high momentum resolution, large acceptance, particle identification and calorimetry. A short pilot run in 2004 resulted in the observation of a spin-exotic state with JPC=1−+J^{PC} = 1^{-+} consistent with the debated π1(1600)\pi1(1600). In addition, Coulomb production at low momentum transfer data provide a test of Chiral Perturbation Theory. During 2008 and 2009, a world leading data set was collected with hadron beam which is currently being analysed. The large statistics allows for a thorough decomposition of the data into partial waves. The COMPASS hadron data span over a broad range of channels and shed light on several different aspects of QCD.Comment: 4 pages, 5 figure

    Electrical conductivity and phase diagram of binary alloys. 21: The system palladium-chromium

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    Pd-Cr alloys were investigated by thermal analysis, hardness measurements, X-ray analysis, microscopic examination of etched pieces, and temperature-resistance curves of the solid alloys. Only one compound, Pd2Cr3, m, 1389 deg, is formed. It possesses a cubic face centered lattice and forms with excess Pd a series of solid solutions with a minimum m.p. at 45 atoms% Pd. Hardness maximum appears at the Pd2Cr3 point. Pd2Cr3 forms no solid solutions with Cr but eutectic point appears at 25 atoms% Pd, m. 1320 deg. The sp. resistance of pure Cr in an atom of H, indicates no allotropic forms. Cr2O3 is solid in molten Cr. Pure Cr melts at 1890 plus or minus 10 deg but Cr contg. Cr2O3 starts to melt at 1770 to 1790 deg

    Magnetic properties of single-crystalline CeCuGa3

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    The magnetic behavior of single-crystalline CeCuGa3 has been investigated. The compound forms in a tetragonal BaAl4-type structure consisting of rare-earth planes separated by Cu-Ga layers. If the Cu-Ga site disorder is reduced, CeCuGa3 adopts the related, likewise tetragonal BaNiSn3-type structure, in which the Ce ion are surrounded by different Cu and Ga layers and the inversion symmetry is lost. In the literature conflicting reports about the magnetic order of CeCuGa3 have been published. Single crystals with the centrosymmetric structure variant exhibit ferromagnetic order below approx. 4 K with a strong planar anisotropy. The magnetic behavior above the transition temperature can be well understood by the crystal-field splitting of the 4f Hund's rule ground-state multiplet of the Ce ions

    Photobiont selectivity leads to ecological tolerance and evolutionary divergence in a polymorphic complex of lichenized fungi

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    Background and Aims The integrity and evolution of lichen symbioses depend on a fine-tuned combination of algal and fungal genotypes. Geographically widespread species complexes of lichenized fungi can occur in habitats with slightly varying ecological conditions, and it remains unclear howthis variation correlates with symbiont selectivity patterns in lichens. In an attempt to address this question, .300 samples were taken of the globally distributed and ecologically variable lichen-forming species complex Tephromela atra, together with closely allied species, in order to study genetic diversity and the selectivity patterns of their photobionts. \u2020 Methods Lichen thalli of T. atra and of closely related species T. grumosa, T. nashii and T. atrocaesia were collected from six continents, across 24 countries and 62 localities representing a wide range of habitats. Analyses of genetic diversity and phylogenetic relationships were carried out both for photobionts amplified directly from the lichen thalli and from those isolated in axenic cultures. Morphological and anatomical traits were studied with light and transmission electron microscopy in the isolated algal strains. \u2020 Key Results Tephromela fungal species were found to associate with 12 lineages of Trebouxia. Five new clades demonstrate the still-unrecognized genetic diversity of lichen algae. Culturable, undescribed lineageswere also characterized by phenotypic traits. Strong selectivity of the mycobionts for the photobionts was observed in six monophyletic Tephromela clades. Seven Trebouxia lineages were detected in the poorly resolved lineage T. atra sensu lato, where co-occurrence of multiple photobiont lineages in single thalli was repeatedly observed. \u2020Conclusions Lowselectivity apparently allows widespread lichen-forming fungi to establish successful symbioses with locally adapted photobionts in a broader range of habitats. This flexibility might correlate with both lower phylogenetic resolution and evolutionary divergence in species complexes of crustose lichen-forming fungi

    Immunological characterization of chromogranins A and B and secretogranin II in the bovine pancreatic islet

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    Antisera against chromogranin A and B and secretogranin II were used for analysing the bovine pancreas by immunoblotting and immunohistochemistry. All three antigens were found in extracts of fetal pancreas by one dimensional immunoblotting. A comparison with the soluble proteins of chromaffin granules revealed that in adrenal medulla and in pancreas antigens which migrated identically in electrophoresis were present. In immunohistochemistry, chromogranin A was found in all pancreatic endocrine cell types with the exception of most pancreatic polypeptide-(PP-) producing cells. For chromogranin B, only a faint immunostaining was obtained. For secretorgranin II, A-and B-cells were faintly positive, whereas the majority of PP-cells exhibited a strong immunostaining for this antigen. These results establish that chromogranins A and B and secretogranin II are present in the endocrine pancreas, but that they exhibit a distinct cellular localization

    The Impact of SAP on the Utilisation of Business Process Management (BPM) Maturity Models in ERP projects

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    The SAP Enterprise Resource Planning (ERP) system is a leading software solution for corporate business functions and processes. Business Process Management (BPM) is a management approach designed to create and manage organizations’ business processes. Both promise an improvement of business processes in companies and can be used together in organizations. In conjunction with the SAP ERP system and BPM approach, BPM maturity models can be used as diagnostic tools that allow an organization to assess and monitor the maturity of its business processes. This research analyses the complex relationships between SAP, BPM and BPM maturity models. The aim is to investigate and analyse the interaction between the use of the SAP ERP software package and the deployment of BPM maturity models. The research adopts a multiple case study approach, based on semi-structured expert interviews, and provides an in-depth insight into how a small number of organizations use SAP, BPM and BPM maturity models

    Managing Process Change and Standardisation in ERP Projects: An Assessment of the SAP Template Approach

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    The use of templates for process alignment in ERP projects is an established practice and many companies have used this approach when implementing the SAP ERP software system. This research paper deals with the question of how companies use a template in a business process management environment and, more specifically, what happens when there are requests for changes to the template. Based on a literature review and personal interviews, this article assesses the commitments that manufacturing companies make regarding template implementation within SAP business process management. It suggests that "Defend the template!" may be an appropriate overarching goal

    Management Guidelines for Better Application of Business Process Management in SAP ERP projects

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    The SAP Enterprise Resource Planning (ERP) system is a leading software solution for corporate business functions and processes. Business Process Management (BPM) is a management approach designed to create and manage organizations’ business processes. Both promise an improvement of business processes in companies and can be used together in organizations. In conjunction with the SAP ERP system and BPM approach, BPM maturity models can be used as diagnostic tools that allow an organization to assess and monitor the maturity of its business processes. The aim is to investigate and analyse the interaction between the use of the SAP ERP software package and the utilization of BPM. Findings derive from an analysis of eleven semi-structured expert interviews and a validation of the guidelines via an online survey with 151 participants that use SAP, BPM and/or BPM maturity models. This research analyses the complex relationships between SAP, BPM and BPM maturity models and develops management guidelines for improved use of BPM in SAP ERP projects

    Theory of Umklapp-assisted recombination of bound excitons in Si:P

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    We present the calculations for the oscillator strength of the recombination of excitons bound to phosphorous donors in silicon. We show that the direct recombination of the bound exciton cannot account for the experimentally measured oscillator strength of the no-phonon line. Instead, the recombination process is assisted by an umklapp process of the donor electron state. We make use of the empirical pseudopotential method to evaluate the Umklapp-assisted recombination matrix element in second-order perturbation theory. Our result is in excellent agreement with the experiment. We also present two methods to improve the optical resolution of the optical detection of the spin state of a single nucleus in silicon.Comment: 9 pages, 6 EPS figures, Revtex
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