1,127 research outputs found

    Fluid-Structure Interaction Simulation of a Coriolis Mass Flowmeter using a Lattice Boltzmann Method

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    In this paper we use a fluid-structure interaction (FSI) approach to simulate a Coriolis mass flowmeter (CMF). The fluid dynamics are calculated by the open source framework OpenLB, based on the lattice Boltzmann method (LBM). For the structural dynamics we employ the open source software Elmer, an implementation of the finite element method (FEM). A staggered coupling approach between the two software packages is presented. The finite element mesh is created by the mesh generator Gmsh to ensure a complete open source workflow. The Eigenmodes of the CMF, which are calculated by modal analysis are compared with measurement data. Using the estimated excitation frequency, a fully coupled, partitioned, FSI simulation is applied to simulate the phase shift of the investigated CMF design. The calculated phaseshift values are in good agreement to the measurement data and verify the suitability of the model to numerically describe the working principle of a CMF

    Update on Babesiosis

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    Human babesiosis is an emerging tick-borne infectious disease caused by intraerythrocytic protozoan species of the genus Babesia with many clinical features similar to those of malaria. Over the last 50 years, the epidemiology of human babesiosis has changed from a few isolated cases to the establishment of endemic areas in the northeastern and midwestern United States. Episodic cases are reported in Europe, Asia, Africa, and South America. The severity of infection ranges from asymptomatic infection to fulminant disease resulting in death, although the majority of healthy adults experience a mild-to-moderate illness. People over the age of 50 years and immunocompromised individuals are at the highest risk of severe disease, including those with malignancy, HIV, lacking a spleen, or receiving immunosuppressive drugs. Asymptomatic carriers present a blood safety risk when they donate blood. Definitive diagnosis of babesial infection generally is made by microscopic identification of the organism on thin blood smear, amplification of Babesia DNA using PCR, and detection of Babesia antibody in acute and convalescent sera. Specific antimicrobial therapy consists of atovaquone and azithromycin or clindamycin and quinine. Exchange transfusion is used in severe cases. The use of multiple prevention strategies is recommended and consists of personal, residential, and community approaches

    Variations in the ovsynch protocol alter pregnancy rates in lactating dairy cows

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    Initiation of the Ovsynch protocol at random stages of the estrous cycle produces differences in synchronization and pregnancy rates. Use of two injections of PGF2αadministered 14 days apart, with the second injection given 12 days before initiating the Ovsynch protocol increased the percentage of cows that start the Ovsynch protocol at a more desirable stage of the estrous cycle (e.g., between days 5 and 13). In this experiment, after applying the Presynch-Ovsynch protocol, timing of the second injection of GnRH and insemination were altered to determine their effect on pregnancy rates. Cows that received the second GnRH injection at the same time as they were inseminated at 72 hours after PGF2αhad greater pregnancy rates than cows that received the second GnRH injection at 48 hours after PGF2αand were inseminated 0 or 24 hours later.; Dairy Day, 2003, Kansas State University, Manhattan, KS, 2003

    Pion photoproduction off the proton in a gauge-invariant chiral unitary framework

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    We investigate pion photoproduction off the proton in a manifestly gauge-invariant chiral unitary extension of chiral perturbation theory. In a first step, we consider meson-baryon scattering taking into account all next-to-leading order contact interactions. The resulting low-energy constants are determined by a fit to s-wave pion-nucleon scattering and the low-energy data for the reaction pi- p --> eta n. To assess the theoretical uncertainty, we perform two different fit strategies. Having determined the low-energy constants, we then analyse the data on the s-wave multipole amplitudes E0+ of pion and eta photoproduction. These are parameter-free predictions, as the two new low-energy constants are determined by the neutron and proton magnetic moments.Comment: 23 pages, 17 figure

    Fluid–structure interaction simulation of a coriolis mass flowmeter using a lattice boltzmann method

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    In this paper, we use a fluid–structure interaction (FSI) approach to simulate a Coriolis mass flowmeter (CMF). The fluid dynamics is calculated by the open-source framework OpenLB, based on the lattice Boltzmann method (LBM). For the structural dynamics we employ the open-source software Elmer, an implementation of the finite element method (FEM). A staggered coupling approach between the two software packages is presented. The finite element mesh is created by the mesh generator Gmsh to ensure a complete open source workflow. The Eigenmodes of the CMF, which are calculated by modal analysis, are compared with measurement data. Using the estimated excitation frequency, a fully coupled, partitioned, FSI simulation is applied to simulate the phase shift of the investigated CMF design. The calculated phase shift values are in good agreement to the measurement data and verify the suitability of the model to numerically describe the working principle of a CMF

    Inner Molecular Rings in Barred Galaxies: BIMA SONG CO Observations

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    Although inner star-forming rings are common in optical images of barred spiral galaxies, observational evidence for the accompanying molecular gas has been scarce. In this paper we present images of molecular inner rings, traced using the CO (1-0) emission line, from the Berkeley-Illinois-Maryland-Association Survey of Nearby Galaxies (BIMA SONG). We detect inner ring CO emission from all five SONG barred galaxies classified as inner ring (type (r)). We also examine the seven SONG barred galaxies classified as inner spiral (type (s)); in one of these, NGC 3627, we find morphological and kinematic evidence for a molecular inner ring. Inner ring galaxies have been classified as such based on optical images, which emphasize recent star formation. We consider the possibility that there may exist inner rings in which star formation efficiency is not enhanced. However, we find that in NGC 3627 the inner ring star formation efficiency is enhanced relative to most other regions in that galaxy. We note that the SONG (r) galaxies have a paucity of CO and H alpha emission interior to the inner ring (except near the nucleus), while NGC 3627 has relatively bright bar CO and H alpha emission; we suggest that galaxies with inner rings such as NGC 3627 may be misclassified if there are significant amounts of gas and star formation in the bar.Comment: To be published in the Astrophysical Journal, July 2002 A version of the paper with full resolution figures is available at: http://www.astro.umd.edu/~mregan/ms.ps.g

    Interpersonal responses to facial expressions of disgust, anger, and happiness in individuals with varying levels of social anxiety

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    BACKGROUND AND OBJECTIVES: Facial expression recognition has been studied extensively, including in relation to social anxiety. Nonetheless, a limited number of studies examined recognition of disgust expressions. Results suggest that disgust is perceived as more threatening than anger, and thus may invite more extreme responses. However, few studies have examined responses to facial expressions. These studies have focused on approach-avoidance responses. Our primary aim was to examine to what extent anger and disgust expressions might invite interpersonal responses in terms of quarrelsomeness-agreeableness and dominance-submissiveness. As social anxiety has been previously associated with a heightened sensitivity to anger and disgust expressions, as well as with alterations in quarrelsomeness-agreeableness and dominance-submissiveness, our secondary aim was to examine whether social anxiety would moderate these responses. METHODS: Participants were 55 women and 43 men who completed social anxiety measures, including the Brief Fear of Negative Evaluation scale, and two tasks that involved “targets” expressing anger, disgust, or happiness at 0%, 50%, or 100%. Participants first indicated how quarrelsome or agreeable and how dominant or submissive they would be towards each target, and then how much they would avoid or approach each target. RESULTS: While 100% disgust and anger expressions invited similar levels of quarrelsomeness and avoidance, 50% disgust invited more quarrelsomeness and stronger avoidance than 50% anger. While these patterns were not meaningfully moderated by social anxiety, individuals with higher BFNE scores showed a relatively strong approach of happy faces. LIMITATIONS: Actual interpersonal behaviour in response to facial expressions was not assessed. CONCLUSIONS: Findings support the relevance of disgust as an interpersonal signal and suggest that, especially at mild intensity, disgust may have a stronger impact than anger on people’s quarrelsomeness and avoidance responses. Findings provided no support for the view that people with social anxiety would be particularly responsive to disgust (or anger) expressions

    Entomologic and Serologic Evidence of Zoonotic Transmission of Babesia microti, Eastern Switzerland

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    We evaluated human risk for infection with Babesia microti at a site in eastern Switzerland where several B. microti–infected nymphal Ixodes ricinus ticks had been found. DNA from pooled nymphal ticks amplified by polymerase chain reaction was highly homologous to published B. microti sequences. More ticks carried babesial infection in the lower portion of the rectangular 0.7-ha grid than in the upper (11% vs. 0.8%). In addition, we measured seroprevalence of immunoglobulin (Ig) G antibodies against B. microti antigen in nearby residents. Serum from 1.5% of the 396 human residents of the region reacted to B. microti antigen (>1:64), as determined by indirect immunofluorescence assay (IgG). These observations constitute the first report demonstrating B. microti in a human-biting vector, associated with evidence of human exposure to this agent in a European site
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