36,437 research outputs found

    Vibrophonocardiograph Patent

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    Vibrophonocardiograph comprising low weight and small volume piezoelectric microphone with amplifier having high imput impedance for high sensitivity and low frequency respons

    Balloon borne humidity and aerosol sensors

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    Infrared detectors for balloon sensing of aerosols and atmospheric moistur

    Creating ultracold molecules by collisions with ultracold rare gas atoms in an optical trap

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    We study collisions of para-H2_2 with five rare gas atomic species (He, Ne, Ar, Kr and Xe) over the range from 1 K to 1 μ\mu K and evaluate the feasibility of sympathetic cooling H2_2 with ultracold ground state rare gas atoms co-trapped within a deep optical trap. Collision cross-sections over this large temperature range show that all of these species could be used to cool H2_2 to ultracold temperatures and that argon and helium are the most promising species for future experiments.Comment: 5 pages, 1 figure, 1 table, submitted for publicatio

    Super-resolution imaging of a low frequency levitated oscillator

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    We describe the measurement of the secular motion of a levitated nanoparticle in a Paul trap with a CMOS camera. This simple method enables us to reach signal-to-noise ratios as good as 106^{6} with a displacement sensitivity better than 1016m2^{-16}\,m^{2}/Hz. This method can be used to extract trap parameters as well as the properties of the levitated particles. We demonstrate continuous monitoring of the particle dynamics on timescales of the order of weeks. We show that by using the improvement given by super-resolution imaging, a significant reduction in the noise floor can be attained, with an increase in the bandwidth of the force sensitivity. This approach represents a competitive alternative to standard optical detection for a range of low frequency oscillators where low optical powers are require

    A database transaction scheduling tool in Prolog

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    In this paper, we describe an item of "intelligent" educational software that is intended to help students taking university computer science courses to understand the fundamentals of transaction scheduling. The software, implemented in PROLOG, empowers students to construct their own learning environment and is able to provide tailored forms of feedback to different types of learner. We describe the development and evaluation of the software, and we present details of the analysis of the results of our investigation into the effectiveness of the software as a teaching and learning tool. Our results suggest that our learning tool provides students with a different and valuable type of learning experience, which traditional methods do not provide

    An e-learning tool for understanding schedule properties

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    In this paper, we describe an e-learning tool that we have developed to assist University students studying various modules on database systems. We use the acronym DTST (viz. a learning tool for Database Transaction Schedule Testing) to refer to our learning tool. DTST enables students to actively construct their own learning environment, it can respond in an individualistic way to student input, and it has a built-in web interface that makes it widely accessible. Field tests conducted on DTST suggest that it provides students with a different and valuable type of learning experience that traditional methods do not provide

    LANDSAT-4 multispectral scanner (MSS) subsystem radiometric characterization

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    The multispectral band scanner (mass) and its spectral characteristics are described and methods are given for relating video digital levels on computer compatible tapes to radiance into the sensor. Topics covered include prelaunch calibration procedures and postlaunch radiometric processng. Examples of current data resident on the MSS image processing system are included. The MSS on LANDSAT 4 is compared with the scanners on earlier LANDSAT satellites
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