57 research outputs found

    Cold SO_2 molecules by Stark deceleration

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    We produce SO_2 molecules with a centre of mass velocity near zero using a Stark decelerator. Since the initial kinetic energy of the supersonic SO_2 molecular beam is high, and the removed kinetic energy per stage is small, 326 deceleration stages are necessary to bring SO_2 to a complete standstill, significantly more than in other experiments. We show that in such a decelerator possible loss due to coupling between the motional degrees of freedom must be considered. Experimental results are compared with 3D Monte-Carlo simulations and the quantum state selectivity of the Stark decelerator is demonstrated.Comment: 7 pages, 5 figure

    A continuous source of translationally cold dipolar molecules

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    The Stark interaction of polar molecules with an inhomogeneous electric field is exploited to select slow molecules from a room-temperature reservoir and guide them into an ultrahigh vacuum chamber. A linear electrostatic quadrupole with a curved section selects molecules with small transverse and longitudinal velocities. The source is tested with formaldehyde (H2CO) and deuterated ammonia (ND3). With H2CO a continuous flux is measured of approximately 10^9/s and a longitudinal temperature of a few K. The data are compared with the result of a Monte Carlo simulation.Comment: 4 pages, 4 figures v2: small changes in the abstract, text and references. Figures 1 & 2 regenerated to prevent errors in the pd

    A Storage Ring for Neutral Atoms

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    We have demonstrated a storage ring for ultra-cold neutral atoms. Atoms with mean velocities of 1 m/s corresponding to kinetic energies of ~100 neV are confined to a 2 cm diameter ring by magnetic forces produced by two current-carrying wires. Up to 10^6 atoms are loaded at a time in the ring, and 7 revolutions are clearly observed. Additionally, we have demonstrated multiple loading of the ring and deterministic manipulation of the longitudinal velocity distribution of the atoms using applied laser pulses. Applications of this ring include large area atom interferometers and cw monochromatic atomic beam generation.Comment: 4 pages, 5 figure

    Ensuring the quality and specificity of preregistrations

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    Researchers face many, often seemingly arbitrary, choices in formulating hypotheses, designing protocols, collecting data, analyzing data, and reporting results. Opportunistic use of “researcher degrees of freedom” aimed at obtaining statistical significance increases the likelihood of obtaining and publishing false-positive results and overestimated effect sizes. Preregistration is a mechanism for reducing such degrees of freedom by specifying designs and analysis plans before observing the research outcomes. The effectiveness of preregistration may depend, in part, on whether the process facilitates sufficiently specific articulation of such plans. In this preregistered study, we compared 2 formats of preregistration available on the OSF: Standard Pre-Data Collection Registration and Prereg Challenge Registration (now called “OSF Preregistration,” http://osf.io/prereg/). The Prereg Challenge format was a “structured” workflow with detailed instructions and an independent review to confirm completeness; the “Standard” format was “unstructured” with minimal direct guidance to give researchers flexibility for what to prespecify. Results of comparing random samples of 53 preregistrations from each format indicate that the “structured” format restricted the opportunistic use of researcher degrees of freedom better (Cliff’s Delta = 0.49) than the “unstructured” format, but neither eliminated all researcher degrees of freedom. We also observed very low concordance among coders about the number of hypotheses (14%), indicating that they are often not clearly stated. We conclude that effective preregistration is challenging, and registration formats that provide effective guidance may improve the quality of research

    Australia's servicewomen and female veterans: do we understand their health needs?

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    Susan J Neuhaus and Samantha L Crompvoet

    Development of Local Spatial Data Infrastructure in Croatia

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    This work provides insight into the Croatian Local Spatial Data Infrastructure (LSDI). Field data collected in 2012 by means of a questionnaire formed the basis of this work. The questionnaire respondents were Croatian cities. The results were analysed according to city population, city budget and city area. An analysis was also performed according to European Union Nomenclature of Territorial Units for Statistics 2 regions. Analysis showed significant LSDI differences between bigger and smaller cities. Some of the LSDI indicators are more suitable for Croatian relations than other. The indicators used and the analysis of their reliability could be adopted in other countries. © 2014 © 2014 Mapping Sciences Institute, Australia and Surveying and Spatial Sciences Institute.peerreview_statement: The publishing and review policy for this title is described in its Aims & Scope. aims_and_scope_url: http://www.tandfonline.com/action/journalInformation?show=aimsScope&journalCode=tjss20status: publishe

    3D geo-information innovation in Europe's public mapping agencies: A public value perspective

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    © 2018 by the authors. Intensifying and increasingly complex physical developments under, on, and above ground, as well as the speed and accessibility of digital innovation, is resulting in growing interest in public sector investment in 3D geo-information. In Europe, a consortium of 11 public mapping agencies (PMAs) recently undertook a cost-benefit analysis for pursuing adoption of 3D geo-information. However, broader public management literature has shown that while economic value is vital for justifying public investment, it is not the only driving factor and that the creation of public value is crucially and equally significant as it conveys social and political legitimacy. Using a public value perspective, this paper aims to re-examine the data collected by the consortium of PMAs. Content analysis of the qualitative data provides strong examples of how 3D geo-information may potentially manifest as different types of public value across a broad public of stakeholders as well as providing evidence that such innovation would likely be politically as well as operationally viable. Nonetheless, the lack of a clear obvious need for 3D geo-information that responds to a specific societal challenge may pose an impediment to successful innovation.status: publishe
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