14,616 research outputs found

    Atomic level micromagnetic model of recording media switching at elevated temperatures

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    An atomic level micromagnetic model of granular recording media is developed and applied to examine external field-induced grain switching at elevated temperatures which captures non-uniform reversal modes. The results are compared with traditional methods which employ the Landau-Lifshitz-Gilbert equations based on uniformly magnetized grains with assigned intrinsic temperature profiles for M(T)M(T) and K(T)K(T). Using nominal parameters corresponding to high-anisotropy FePt-type media envisioned for Energy Assisted Magnetic Recording, our results demonstrate that atomic-level reversal slightly reduces the field required to switch grains at elevated temperatures, but results in larger fluctuations, when compared to a uniformly magnetized grain model.Comment: 4 pages, 5 figure

    Iterative maximum-likelihood reconstruction in quantum homodyne tomography

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    I propose an iterative expectation maximization algorithm for reconstructing a quantum optical ensemble from a set of balanced homodyne measurements performed on an optical state. The algorithm applies directly to the acquired data, bypassing the intermediate step of calculating marginal distributions. The advantages of the new method are made manifest by comparing it with the traditional inverse Radon transformation technique

    A comparison of the use of coaptation U-splintage and a Polypropylene brace for humeral shaft fractures

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    Eighty-eight patients with humeral shaft fractures seen at Mulago hospital, Kampala, were randomly distributed into two groups. In Group A, 58 patients were treated conservatively using a coaptation U-splint of plaster of Paris while 30 patients in Group B were treated with a humeral brace. There were more males than females (M:F;1.75:1). Most patients (680) were aged 18 years or over. Road traffic accidents accounted for 64% of the fractures. Four patients had associated radial nerve damage.There was a statistically significant difference in fracture healing times between closed and open fractures but no statistically significant difference in healing was noted in those patients treated with coaptation U-splints and those with a humeral brace. Full recovery of flexion and extension of the elbow was shorter in patients treated with the humeral brace (Group R) than in U-splints (Group A) and the difference was statistically significant (p value < 0.001). The functional humeral brace was found to be superior to the coaptation U-splint as regards functional results and is therefore recommended for those patients who can afford its use.Keywords: Humeral fractures, treatment, U-Splint, brac

    Field Independence Associates with Mathematics and Science Performance in 5-to 10-Year-Olds after Accounting for Domain-General Factors

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    Field independence describes the extent to which individuals are influenced by context when trying to identify embedded targets. It associates with cognitive functioning and is a predictor of academic achievement. However, little is known about the neural and cognitive underpinnings of field independence that lead to these associations. Here, we investigated behavioral associations between two measures of field independence (Children's Embedded Figures Test [CEFT] and Design Organization Test [DOT]) and performance on tests of mathematics (reasoning and written arithmetic) and science (reasoning and scientific inquiry) in 135 children aged 5–10 years. There were strong associations between field independence and mathematics and science, which were largely explained by individual differences in age, intelligence, and verbal working memory. However, regression analyses indicated that after controlling for these variables, the CEFT explained additional variance on the mathematical reasoning and science tests, whereas the DOT predicted unique variance on the written arithmetic test

    Resistivity due to low-symmetrical defects in metals

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    The impurity resistivity, also known as the residual resistivity, is calculated ab initio using multiple-scattering theory. The mean-free path is calculated by solving the Boltzmann equation iteratively. The resistivity due to low-symmetrical defects, such as an impurity-vacancy pair, is calculated for the FCC host metals Al and Ag and the BCC transition metal V. Commonly, 1/f noise is attributed to the motion of such defects in a diffusion process.Comment: 24 pages in REVTEX-preprint format, 10 Postscript figures. Phys. Rev. B, vol. 57 (1998), accepted for publicatio

    An overview of multi-criteria decision-making methods in dealing with sustainable energy development issues

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    © 2018 by the authors. The measurement of sustainability is actively used today as one of the main preventative instruments in order to reduce the decline of the environment. Sustainable decision-making in solving energy issues can be supported and contradictory effects can be evaluated by scientific achievements of multi-criteria decision-making (MCDM) techniques. The main goal of this paper is to overview the application of decision-making methods in dealing with sustainable energy development issues. In this study, 105 published papers from the Web of Science Core Collection (WSCC) database are selected and reviewed, from 2004 to 2017, related to energy sustainability issues and MCDM methods. All the selected papers were categorized into 9 fields by the application area and into 10 fields by the used method. After the categorization of the scientific articles and detailed analysis, SWOT analysis of MCDM approaches in dealing with sustainable energy development issues is provided. The widespread application and use of MCDM methods confirm that MCDM methods can help decision-makers in solving energy sustainability problems and are highly popular and used in practice

    Insights into pneumococcal pneumonia using lung aspirates and nasopharyngeal swabs collected from pneumonia patients in The Gambia.

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    We investigated the pathogenesis of pneumococcal pneumonia using clinical specimens collected for pneumonia surveillance in The Gambia. Lung aspirates and nasopharyngeal swabs from 31 patients were examined by culture, qPCR, whole genome sequencing, serotyping, and reverse transcription qPCR. Five lung aspirates cultured pneumococci, with a matching strain identified in the nasopharynx. Three virulence genes including ply (pneumolysin) were upregulated >20-fold in the lung compared with the nasopharynx. Nasopharyngeal pneumococcal density was higher in pediatric pneumonia patients compared with controls (p <0.0001). Findings suggest that changes in pneumococcal gene expression occurring in the lung environment may be important in pathogenesis

    Entanglement generation in continuously coupled parametric generators

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    We investigate a compact source of entanglement. This device is composed of a pair of linearly coupled nonlinear waveguides operating by means of degenerate parametric downconversion. For the vacuum state at the input the generalized squeeze variance and logarithmic negativity are used to quantify the amount of nonclassicality and entanglement of output beams. Squeezing and entanglement generation for various dynamical regimes of the device are discussed.Comment: 6 pages, 7 figure
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