1,407 research outputs found

    UNTERSUCHUNG ÜBER DIE HERSTELLUNG VON LANGKETTIGEN PRIMÄREN ALKYLCHLORIDEN

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    Automated operation of a home made torque magnetometer using LabVIEW

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    In order to simplify and optimize the operation of our home made torque magnetometer we created a new software system. The architecture is based on parallel, independently running instrument handlers communicating with a main control program. All programs are designed as command driven state machines which greatly simplifies their maintenance and expansion. Moreover, as the main program may receive commands not only from the user interface, but also from other parallel running programs, an easy way of automation is achieved. A program working through a text file containing a sequence of commands and sending them to the main program suffices to automatically have the system conduct a complex set of measurements. In this paper we describe the system's architecture and its implementation in LabVIEW.Comment: 6 pages, 7 figures, submitted to Rev. Sci. Inst

    SYNTHESIS AND APPLICATION OF CROWN ETHERS

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    Mono- and bis-benzo-15-crown-5-ether derivatives have been synthesized and determined their potentiometric K+ selectivity factors. Of bis-crown ether urethanes highly selective Iigands were found some of which was used as active ingredient in potassium selective membrane electrode. Sugar based crown ethers, aza-crowns and cryptands were also prepared and applied as chiral catalyst in enantioselective reactions

    Alternative optical concept for electron cyclotron emission imaging

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    The implementation of advanced electron cyclotron emission imaging (ECEI) systems on tokamak experiments has revolutionized the diagnosis of magnetohydrodynamic (MHD) activities and improved our understanding of instabilities, which lead to disruptions. It is therefore desirable to have an ECEI system on the ITER tokamak. However, the large size of optical components in presently used ECEI systems have, up to now, precluded the implementation of an ECEI system on ITER. This paper describes a new optical ECEI concept that employs a single spherical mirror as the only optical component and exploits the astigmatism of such a mirror to produce an image with one-dimensional spatial resolution on the detector. Since this alternative approach would only require a thin slit as the viewing port to the plasma, it would make the implementation of an ECEI system on ITER feasible. The results obtained from proof-of-principle experiments with a 125 GHz microwave system are presented. (C) 2014 AIP Publishing LLC

    Nuclear Magnetic Resonance and Hyperfine Structure

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    Contains research objectives and reports on two research projects

    Magnet Laboratory Research

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    Contains reports on three research projects

    Graded supplementation of chestnut tannins to dairy cows fed protein-rich spring pasture: effects on indicators of protein utilization

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    An on-farm experiment was conducted in order to evaluate effects of graded supplementation with chestnut tannin extract to cows in situations of excessive dietary protein supply on a low-input organic dairy farm. Respectively 10 Swiss Fleckvieh cows received twice per day 1 kg of experimental pellets containing either 0, 50 or 100 g/kg of chestnut extract (targeted at approximately 0, 5 and 10 g extract/kg of total dietary dry matter). Experimental feeding lasted for 21 days. Measurements and collection of milk, faeces and urine spot samples were performed in weeks 0 (baseline), 1 and 3. All cows were kept in one herd on pasture; fresh grass and grass hay were provided in the barn during night. Milk yield was recorded and cows wore sensor halters for recording chewing activity. In urine, total nitrogen and purine derivatives were measured; faeces were analyzed for protein, fibre and particle fractions; in milk, solid concentrations were determined. The data was analyzed with a general linear model. Cows did not show differences in general eating and rumination behaviour, but needed time to accept the tannin-containing pellets. Milk yield and composition were not affected by treatment, except for lactose content. No relevant differences between treatments were found for urinary and faecal parameters. In conclusion, although technically easy to supplement, pellets containing chestnut tannin extract were not readily accepted by the cows and effects on protein digestion and metabolism were not found. Successful on-farm application of chestnut extract in order to improve nitrogen efficiency therefore seems questionable

    Coherent Ro-vibrational Revivals in a Thermal Molecular Ensemble

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    We report an experimental and theoretical study of the evolution of vibrational coherence in a thermal ensemble of nitrogen molecules. Rotational dephasing and rephasing of the vibrational coherence is detected by coherent anti-Stokes Raman scattering. The existence of ro-vibrational coupling and the discrete energy spectrum of the rotational bath lead to a whole new class of full and fractional ro-vibrational revivals. Following the rich ro-vibrational dynamics on a nanosecond time scale with sub-picosecond time resolution enables us to determine the second-order ro-vibrational constant gammaegamma_e and assess new possibilities of controlling decoherence.Comment: submitted at Physical Review

    Associations between Faculty Vitality and Burnout in the COVID-19 Era: the Experience of One Institution

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    Introduction: Faculty vitality is the ideal synergy between engaged faculty and mission-driven institutions that generates a fruitful environment for academic productivity, career satisfaction, and fulfillment of shared goals. The COVID-19 pandemic has introduced unprecedented disruptions to faculty vitality, with profound perturbations to individual and institutional support networks. However, the extent of this impact is unclear, as are strategies to mitigate loss of faculty vitality and prevent burnout. Methods: We developed a survey instrument to evaluate the impact of COVID-19 on faculty vitality and burnout at a mid-sized, Midwestern academic institution affiliated with a university hospital. Survey items focused on individual and institutional factors that are predictive of faculty vitality, organized around themes of work-life integration, professional engagement, and institutional support. The survey also evaluated the impact of interventions implemented in response to the pandemic on faculty burnout. Results: One hundred and thirty-eight clinical and basic science faculty participated in the survey. Female faculty are less satisfied with work-life integration since the onset of the pandemic. Almost all (98.2%) faculty respondents experienced detriments to their professional development, and 38% believed their research was affected. Faculty of color experienced more detrimental effects on their professional development. Self-reported burnout increased from 23.6% before to 44.8% after the pandemic. Burnout was associated with lack of career development opportunities, whereas career satisfaction and utilization of university support efforts were protective. Conclusion: Faculty vitality has decreased since the pandemic began, but institutional support can mitigate these detrimental effects. Additional research on the efficacy of interventions to support female faculty, early-career researchers, and under-represented minorities in medicine is needed

    Nuclear Magnetic Resonance and Hyperfine Structure

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    Contains research objectives and reports on one research project
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