697 research outputs found

    Improvement of magnetic hardness at finite temperatures: ab initio disordered local moment approach for YCo5_5

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    Temperature dependence of the magnetocrystalline anisotropy energy and magnetization of the prototypical rare-earth magnet YCo5_5 is calculated from first principles, utilizing the relativistic disordered local moment approach. We discuss a strategy to enhance the finite-temperature anisotropy field by hole doping, paving the way for an improvement of the coercivity near room temperature or higher.Comment: 12 pages, 13 figures, some corrections made and a reference update

    Design and fabrication of a data logger for atmospheric pressure, temperature and relative humidity for gas-filled detector development

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    A novel instrument has been developed to monitor and record the ambient pa- rameters such as temperature, atmospheric pressure and relative humidity. These parameters are very essential for understanding the characteristics such as gain of gas filled detectors like Gas Electron Multiplier (GEM) and Multi Wire Propor- tional Counter (MWPC). In this article the details of the design, fabrication and operation processes of the device has been presented.Comment: 11 pages, 12 figure

    Phylogenomic and comparative genomic studies robustly demarcate two distinct clades of Pseudomonas aeruginosa strains: proposal to transfer the strains from an outlier clade to a novel species Pseudomonas paraeruginosa sp. nov

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    The strains of Pseudomonas aeruginosa exhibit considerable differences in their genotypic and pathogenic properties. To clarify their evolutionary/taxonomic relationships, comprehensive phylogenomic and comparative genomic studies were conducted on the genome sequences of 212 P. aeruginosa strains covering their genetic diversity. In a phylogenomic tree based on 118 conserved proteins, the analysed strains formed two distinct clades. One of these clades, Clade- 1, encompassing >70 % of the strains including the type strain DSM 50071T, represents the species P. aeruginosa sensu stricto. Clade- 2, referred to in earlier work as the outlier group, with NCTC 13628T as its type strain, constitutes a novel species level lineage. The average nucleotide identity, average amino acid identity and digital DNA–DNA hybridization values between the strains from Clade- 1 and Clade- 2 are in the range of 93.4–93.7, 95.1–95.3 and 52–53 %, respectively. The 16S rRNA gene of P. aeruginosa DSM 50071T also shows 98.3 % similarity to that of NCTC13628T. These values are lower than the suggested cut- off values for species distinction, indicating that the Clade- 2 strains (NCTC 13628T) constitute a new species. We also report the identification of 12 conserved signature indels in different proteins and 24 conserved signature proteins that are exclusively found in either Clade- 1 or Clade- 2, providing a reliable means for distinguishing these clades. Additionally, in contrast to swimming motility, twitching motility is only present in Clade- 1 strains. Based on earlier work, the strains from these two clades also differ in their pathogenic mechanisms (presence/absence of Type III secretion system), production of biosurfactants, phenazines and siderophores, and several other genomic characteristics. Based on the evidence from different studies, we propose that the Clade- 2 strains constitute a novel species for which the name Pseudomonas paraeruginosa is proposed. The type strain is NCTC 13628T (=PA7T=ATCC 9027T). The description of Pseudomonas aeruginosa is also emended to include information for different molecular markers specific for this species

    Luttinger liquid behavior in weakly disordered quantum wires

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    We have measured the temperature dependence of the conductance in long V-groove quantum wires (QWRs) fabricated in GaAs/AlGaAs heterostructures. Our data is consistent with recent theories developed within the framework of the Luttinger liquid model, in the limit of weakly disordered wires. We show that for the relatively small amount of disorder in our QWRs, the value of the interaction parameter g is g=0.66, which is the expected value for GaAs. However, samples with a higher level of disorder show conductance with stronger temperature dependence, which does not allow their treatment in the framework of perturbation theory. Trying to fit such data with perturbation-theory models leads inevitably to wrong (lower) values of g.Comment: 4 pages, 4 figure

    Virtual Team Role Play Using Second Life for Teaching Business Process Concepts

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    This paper describes the use of a virtual world environment to facilitate a role play assignment for buying and selling Enterprise Resource Planning (ERP) software solutions in a distributed environment. The exercise involved the use of Second Life to facilitate the virtual presentation and meeting among the vendors and the purchaser of the software. Students playing vendors and purchase roles were organized into teams who meet, collaborate, and negotiate business transactions in the virtual environment. The aim of the experiment was to introduce students to properties of ERP-systems which are the most common software systems used by businesses, and at the same time introduce tools for virtual team collaboration in an international setting between students in Norway and Australia. This paper reports the experiences from the students' and teachers' perspectives and we give recommendations regarding the use of Second Life in role-playing exercises

    Teaching business process concepts using enterprise systems in a globalized context

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    There is significant growth in global business operations and ERP systems are deemed as important applications in order to unify and improve fragmented and globalised markets. These systems are complex and students struggle to grasp not only the underlying business concepts but also the technology involved. The paper describes the design and implementation of teaching materials for a multinational cross-company collaboration assignment using a commercial ERP system. It includes elements of 1) integrated business processes, 2) globalization and 3) experiential learning in masters courses at two universities - one in Australia and the other in Norway. We discuss the lessons learned from the pilot study including the development of an evaluation tool, inter-university student communication, evaluation of the learning outcome, and the benefits of the cross-country business role play exercise

    Flexible Coloring

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    Motivated by reliability considerations in data deduplication for storage systems, we introduce the problem of flexible coloring. Given a hypergraph H and the number of allowable colors k, a flexible coloring of H is an assignment of one or more colors to each vertex such that, for each hyperedge, it is possible to choose a color from each vertex’s color list so that this hyperedge is strongly colored (i.e., each vertex has a different color). Different colors for the same vertex can be chosen for different incident hyperedges (hence the term flexible). The goal is to minimize color consumption, namely, the total number of colors assigned, counting multiplicities. Flexible coloring is NP-hard and trivially s − (s−1)k n approximable, where s is the size of the largest hyperedge, and n is the number of vertices. Using a recent result by Bansal and Khot, we show that if k is constant, then it is UGC-hard to approximate to within a factor of s − ε, for arbitrarily small constant ε> 0. s − (s−1)k k ′ Lastly, we present an algorithm with an approximation ratio, where k ′ is number of colors used by a strong coloring algorithm for H. Keywords: graph coloring, hardness of approximatio
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