59 research outputs found

    The first frost in the Pipe Nebula

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    Spectroscopic studies of ices in nearby star-forming regions indicate that ice mantles form on dust grains in two distinct steps, starting with polar ice formation (H2O rich) and switching to apolar ice (CO rich). We test how well the picture applies to more diffuse and quiescent clouds where the formation of the first layers of ice mantles can be witnessed. Medium-resolution near-infrared spectra are obtained toward background field stars behind the Pipe Nebula. The water ice absorption is positively detected at 3.0 micron in seven lines of sight out of 21 sources for which observed spectra are successfully reduced. The peak optical depth of the water ice is significantly lower than those in Taurus with the same visual extinction. The source with the highest water-ice optical depth shows CO ice absorption at 4.7 micron as well. The fractional abundance of CO ice with respect to water ice is 16+7-6 %, and about half as much as the values typically seen in low-mass star-forming regions. A small fractional abundance of CO ice is consistent with some of the existing simulations. Observations of CO2 ice in the early diffuse phase of a cloud play a decisive role in understanding the switching mechanism between polar and apolar ice formation.Comment: 17 pages, 8 figures, accepted by A&

    ST-DPGAN: A Privacy-preserving Framework for Spatiotemporal Data Generation

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    Spatiotemporal data is prevalent in a wide range of edge devices, such as those used in personal communication and financial transactions. Recent advancements have sparked a growing interest in integrating spatiotemporal analysis with large-scale language models. However, spatiotemporal data often contains sensitive information, making it unsuitable for open third-party access. To address this challenge, we propose a Graph-GAN-based model for generating privacy-protected spatiotemporal data. Our approach incorporates spatial and temporal attention blocks in the discriminator and a spatiotemporal deconvolution structure in the generator. These enhancements enable efficient training under Gaussian noise to achieve differential privacy. Extensive experiments conducted on three real-world spatiotemporal datasets validate the efficacy of our model. Our method provides a privacy guarantee while maintaining the data utility. The prediction model trained on our generated data maintains a competitive performance compared to the model trained on the original data

    Globalization and the public sphere: exploring the space of community media in Sydney

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    Recent accounts of Habermas's conception of the public sphere concern the interlocking of multiple networks and spaces. In a global context new interfaces between existing (counter-) public spheres can lead to multiple counter-publics. This article explores this phenomenon through the examination of the communicative spaces that offer alternatives to Australia's mainstream public sphere from three different strands of Sydney's community media: diasporic media (Assyrian Radio SBS), Indigenous media (Koori Radio) and discursive sites that operate in between ethnic and mainstream media (Forum for Australia's Islamic Relations)

    CONFOCAL MICROSCOPY APPLIED TO PALEONTOLOGICAL SPECIMENS

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    AbstractConfocal laser scanning microscopy is a well-established optical technique allowing for three-dimensional (3-D) visualization of fluorescent specimens with a resolution close to the diffraction limit of light. Thanks to the availability of a wide range of fluorescent dyes and selective staining using antibodies, the technique is commonly used in life sciences as a powerful tool for studying different biological processes, often at the level of single molecules. However, this type of approach is often not applicable for specimens that are preserved in historical slide collections, embedded in amber, or are fossilized, and cannot be exposed to any form of selective staining or other form of destructive treatment. This usually narrows the number of microscopic techniques that can be used to study such specimens to traditional light microscopy or scanning electron microscopy. However, these techniques have their own limitations and cannot fully reveal 3-D structures within such barely accessible samples. Can confocal microscopy be of any help? The answer is positive, and it is due to the fact that many paleontological specimens exhibit a strong inherent autofluorescence that can serve as an excellent source of emitted photons for confocal microscopy visualizations either through reconstruction of the induced autoflourescent signal from the sample, or through reconstruction of the reflected signal from the sample surface. Here, we describe the workflow and methodology involved in acquiring confocal data from a sample and reprocessing the resulting image stack using the image-processing program imageJ before reconstructing the data using the open-source 3-D rendering program, Drishti. This approach opens new possibilities for using confocal microscopy in a nondestructive manner for visualizing complex paleontological material that has never previously been considered as suitable for this type of microscopic technique.</jats:p

    A new multi-parallel condition assessment scale for estimating tunnel-induced damage

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    Development of Urban Areas and Geotechnical Engineering. June 16-19, 2008, St. Petersburg, RussiaTraditional means to predict tunnel-induced damage for large groups of potentially affected above ground structures has generally focused on creating a settlement trough and estimating subsequent building response limited by rudimentary aspects of each building’s geometry, structural system, foundation type, and soil bearing capacity. Historically, the procedure is done without consideration for a building’s condition. In this paper, a supplementary step is proposed – one focused on the building’s current state of repair. The presented system employs at its core a widely adopted crack evaluation scale. The main focus is application to unreinforced masonry buildings as they are simultaneously, disproportionately present in urban areas and vulnerable to tunnel movements. The proposed system is herein outlined and applied to a future tunnelling project in Ireland.Science Foundation Irelan

    A new multi-parallel condition assessment scale for estimating tunnel-induced damage

    No full text
    Development of Urban Areas and Geotechnical Engineering. June 16-19, 2008, St. Petersburg, RussiaTraditional means to predict tunnel-induced damage for large groups of potentially affected above ground structures has generally focused on creating a settlement trough and estimating subsequent building response limited by rudimentary aspects of each building’s geometry, structural system, foundation type, and soil bearing capacity. Historically, the procedure is done without consideration for a building’s condition. In this paper, a supplementary step is proposed – one focused on the building’s current state of repair. The presented system employs at its core a widely adopted crack evaluation scale. The main focus is application to unreinforced masonry buildings as they are simultaneously, disproportionately present in urban areas and vulnerable to tunnel movements. The proposed system is herein outlined and applied to a future tunnelling project in Ireland.Science Foundation Irelan

    Intrinsically Switchable Ferroelectric Contour Mode Resonators

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