7,637 research outputs found

    Simultaneous Amplitude and Phase Measurement for Periodic Optical Signals Using Time-Resolved Optical Filtering

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    Time-resolved optical filtering (TROF) measures the spectrogram or sonogram by a fast photodiode followed a tunable narrowband optical filter. For periodic signal and to match the sonogram, numerical TROF algorithm is used to find the original complex electric field or equivalently both the amplitude and phase. For phase-modulated optical signals, the TROF algorithm is initiated using the craters and ridges of the sonogram.Comment: 10 pages, 5 figure

    Investigation of polymer bonded magnetic materials for power conversion

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    Author name used in this publication: K. W. E. ChengAuthor name used in this publication: C. Y. TangAuthor name used in this publication: D. K. W. ChengAuthor name used in this publication: H. WuAuthor name used in this publication: Y. LuPower Electronics Research Centre, Department of Electrical EngineeringRefereed conference paper2001-2002 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe

    Clinical outcome of extended-spectrum beta-lactamase-producing Escherichia coli bacteremia in an area with high endemicity

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    Objectives: This study assessed the impact of discordant empirical antibiotic therapy on the outcome of bacteremia caused by extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli. Methods: The clinical features and outcomes of a cohort of patients hospitalized with ESBL E. coli bacteremia between 2007 and 2008 were retrospectively reviewed. The effect of different antimicrobial regimens on patient outcomes was analyzed. Results: ESBL E. coli accounted for 24.2% (207/857) of E. coli bacteremia cases. The urinary tract (43.6%) was the most common source of infection, followed by the hepatobiliary tract (23.0%). Discordant empirical antibiotic therapy was given to 52.0% patients. Admission to the intensive care unit was associated with the use of a carbapenem as empirical antibiotic therapy (p<. 0.001). Univariate analysis revealed no significant differences in 30-day mortality rates between patients receiving concordant and discordant empirical antibiotic therapy (23.5% vs. 19.8%, p=. 0.526), carbapenem and non-carbapenem empirical antibiotic therapy (29.8% vs. 19.1%, p=. 0.118), beta-lactam/beta-lactam inhibitor combinations (BLBLIs) and non-BLBLIs empirical antibiotic therapy (20.3% vs. 22.3%, p=. 0.734), cephalosporin and non-cephalosporin empirical antibiotic therapy (19.7% vs. 22.6%, p=. 0.639), and fluoroquinolone and non-fluoroquinolone empirical antibiotic therapy (8.3% vs. 22.4%, p=. 0.251). The findings were confirmed by multivariate analysis. Conclusions: Despite a high proportion of discordant empirical antibiotic therapy, ESBL production had little effect on 30-day mortality. Whether the observation can be applied to different ESBL types is unknown and warrants further study. © 2012 International Society for Infectious Diseases.postprin

    Theory of thermalization in an isolated Bose-Einstein condensate

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    Thermalization in an isolated oscillating Bose-Einstein condensate in a disordered trap is investigated. We show Shannon entropy in xx or pp representation is the eligible one to describe the thermalization. Besides, we show that multiple scattering with the disorder generates more and more incoherent thermal particles and condensed and thermal particles act as mutual heat bath that results in the thermalization of the whole system. We also demonstrate that Loschmidt's paradox can be resolved in the present system

    Determining the Transverse Dimensions of Fibers in Wood Using Confocal Microscopy

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    We describe a technique for determining the transverse dimensions of individual fibers in wood using confocal laser scanning microscopy and image analysis. Optical sectioning of confocal microscopy produces high-quality cross-sectional images of large wood samples, thus eliminating the need for traditional mechanical sectioning and its inherent limitations. The relationships between fiber transverse dimensions of wood and kraft pulp fibers, in terms of their means and distributions, are now established. Measuring fibers in wood also allows us now to evaluate properties of early- and latewood separately, and to better understand the origin of heterogeneity. Relative wood density obtained from a wood section correlates strongly to the ratio of fiber wall thickness to perimeter, which is an important parameter for fiber transverse collapse. This direct and accurate method has the potential for automation, thus allowing a rapid assessment of wood quality for papermaking
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