664 research outputs found

    Continuous Centrifuge Decelerator for Polar Molecules

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    Producing large samples of slow molecules from thermal-velocity ensembles is a formidable challenge. Here we employ a centrifugal force to produce a continuous molecular beam with a high flux at near-zero velocities. We demonstrate deceleration of three electrically guided molecular species, CH3_3F, CF3_3H, and CF3_3CCH, with input velocities of up to 200ms1200\,\rm{m\,s^{-1}} to obtain beams with velocities below 15ms115\,\rm{m\,s^{-1}} and intensities of several 109mm2s110^9\,\rm{mm^{-2}\,s^{-1}}. The centrifuge decelerator is easy to operate and can, in principle, slow down any guidable particle. It has the potential to become a standard technique for continuous deceleration of molecules.Comment: 5 pages, 4 figures; version accepted for publication in PR

    INVESTIGATION OF THE RETROGRADATION OF AMYLOSE

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    THE MECHANISM OF THE RETROGRADATION OF AMYLOSE

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    DIE VERKLEISTERUNG DER STÄRKEKÖRNER

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    Step-by-step implementation of BIM-LCA: A case study analysis associating defined construction phases with their respective environmental impacts

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    Building Information Modelling (BIM) supports construction processes by dealing with the variety and complexity of design in a single virtual model. The model may also be complemented by the static and energy performance of buildings. Facing the growing demand of sustainability strategies in the construction sector, the consideration of environmental information within the planning process influences the decision making of planners and stakeholders. Nevertheless, the life cycle assessment of buildings has been so far excluded in BIM, due to the high variety of accurate information and time required. In this paper, a systematic framework is presented and applied to a case study. BIM-LCA assists actors along the planning and designing phase, from the building conception as a whole, up to the elements\u27 details and materials\u27 definition. BIM and LCA intertwine in an application scheme of seven phases for integral planning and four levels of structural composition of a building. With respect to these, involved actors examine potential solutions through a tool which exploits alternative specifications in order to assess the environmental impacts. The goal of this paper is to demonstrate the application of a BIM-LCA model regarding decision making for reliable values of environmental impact in a given structural level of the building. The main findings of this framework are due to the multitude of actors and information orchestrated, namely to uncertainties which characterize the whole planning process and data handling. Through BIMLCA, actors are assisted by ensuring flexibility of models and consistency of results throughout planning and designing

    Application of quasi-Monte Carlo methods to PDEs with random coefficients -- an overview and tutorial

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    This article provides a high-level overview of some recent works on the application of quasi-Monte Carlo (QMC) methods to PDEs with random coefficients. It is based on an in-depth survey of a similar title by the same authors, with an accompanying software package which is also briefly discussed here. Embedded in this article is a step-by-step tutorial of the required analysis for the setting known as the uniform case with first order QMC rules. The aim of this article is to provide an easy entry point for QMC experts wanting to start research in this direction and for PDE analysts and practitioners wanting to tap into contemporary QMC theory and methods.Comment: arXiv admin note: text overlap with arXiv:1606.0661

    Evaluation of an Active LF Tracking System and Data Processing Methods for Livestock Precision Farming in the Poultry Sector

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    Tracking technologies offer a way to monitor movement of many individuals over long time periods with minimal disturbances and could become a helpful tool for a variety of uses in animal agriculture, including health monitoring or selection of breeding traits that benefit welfare within intensive cage-free poultry farming. Herein, we present an active, low-frequency tracking system that distinguishes between five predefined zones within a commercial aviary. We aimed to evaluate both the processed and unprocessed datasets against a “ground truth” based on video observations. The two data processing methods aimed to filter false registrations, one with a simple deterministic approach and one with a tree-based classifier. We found the unprocessed data accurately determined birds’ presence/absence in each zone with an accuracy of 99% but overestimated the number of transitions taken by birds per zone, explaining only 23% of the actual variation. However, the two processed datasets were found to be suitable to monitor the number of transitions per individual, accounting for 91% and 99% of the actual variation, respectively. To further evaluate the tracking system, we estimated the error rate of registrations (by applying the classifier) in relation to three factors, which suggested a higher number of false registrations towards specific areas, periods with reduced humidity, and periods with reduced temperature. We concluded that the presented tracking system is well suited for commercial aviaries to measure individuals’ transitions and individuals’ presence/absence in predefined zones. Nonetheless, under these settings, data processing remains a necessary step in obtaining reliable data. For future work, we recommend the use of automatic calibration to improve the system’s performance and to envision finer movements
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