1,474 research outputs found

    Design and Lessons Learned on the Development of a Cryogenic Pupil Select Mechanism Used in the Testing and Calibration of the Integrated Science Instrument Module (ISIM) on the James Webb Space Telescope (JWST)

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    Calibration and testing of the instruments on the Integrated Science Instrument Module (ISIM) of the James Webb Space Telescope (JWST) is being performed by the use of a cryogenic, full-field, optical simulator that was constructed for this purpose. The Pupil Select Mechanism (PSM) assembly is one of several mechanisms and optical elements that compose the Optical Telescope Element SIMulator, or OSIM. The PSM allows for several optical elements to be inserted into the optical plane of OSIM, introducing a variety of aberrations, distortions, obscurations, and other calibration states into the pupil plane. The following discussion focuses on the details of the design evolution, analysis, build, and test of this mechanism along with the challenges associated with creating a sub arc-minute positioning mechanism operating in an extreme cryogenic environment. In addition, difficult challenges in the control system design will be discussed including the incorporation of closed-loop feedback control into a system that was designed to operate in an open-loop fashion

    Implementing a Theory of a Legal Domain

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    We describe a system for constructing, evaluating and visualising arguments based on a theory of a legal domain, developed using the Angelic methodology and the Carneades argumentation system. The visualisation can be used to explain particular cases and to refine and maintain the theory. A full implementation of the well known US Trade Secrets Domain is used to illustrate the process.</jats:p

    Built Environment Interventions for Human and Planetary Health:Integrating Health in Climate Change Adaption and Mitigation

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    Objectives: Human-generated climate change is causing adverse health effects through multiple direct pathways (e.g. heatwaves, sea-level rise, storm frequency and intensity) and indirect pathways (e.g. food and water insecurity, social instability). Although the health system has a key role to play in addressing these health effects, so too do those professions tasked with the development of the built environment (urban and regional planners, urban designers, landscapers and architects), through improvements to buildings, streets, neighbourhoods, suburbs and cities. This article reports on the ways in which urban planning and design, and architectural interventions, can address the health effects of climate change; and the scope of climate change adaptation and mitigation approaches being implemented by the built environment professions. Type of program or service: Built environment adaptations and mitigations and their connections to the ways in which urban planning, urban design and architectural practices are addressing the health effects of climate change. Methods: Our reflections draw on the findings of a recent review of existing health and planning literature. First, we explore the ways in which ‘adaptation’ and ‘mitigation’ relate to the notion of human and planetary health. We then outline the broad scope of adaptation and mitigation interventions being envisioned, and in some instances actioned, by built environment professionals. Results: Analysis of the review’s findings reveals that adaptations developed by built environment professions predominantly focus on protecting human health and wellbeing from the effects of climate change. In contrast, built environment mitigations address climate change by embracing a deeper understanding of the co-benefits inherent in the interconnectedness of human health and wellbeing and the health of the ecosystem on which it depends. In the final section, we highlight the ethical transition that these approaches demand of built environment professions. Lessons learnt: Built environment interventions must move beyond simple ecological sustainability to encouraging ways of life that are healthy for both humans and the planet. There are key challenges facing this new approach

    Comptes rendus

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    Comptes rendus : Camille Lapointe, Allison Bain et Réginald Auger, Le site archéologique du palais de l’intendant à Québec : Plus de 35 années de découvertes / Chloe Lee-Hone ; Leila Inksetter, Initiatives et adaptations algonquines au xixe siècle / Arnaud Simard-Émond ; Anny Morissette, La lutte se poursuivit en cachette : Le pouvoir des chefs et des leaders de la bande algonquine de Kitigan Zibi / Arnaud Simard-Émond ; Daniel Clément, Les récits de notre terre — Les Algonquins / Thomas Lecomte ; Charmain Levy et Andrea Martinez, Genre, féminismes et développement. Une trilogie en construction / Ninon Capon ; Audrey Laurin-Lamothe, Financiarisation et élite économique au Québec / Yannick Sanschagrin ; Lise Gremion, Serge Ramel, Valérie Angelucci et Jean-Claude Kalubi (éd.), Vers une école inclusive : Regards croisés sur les défis actuels / Marianne Lezea

    Cool Communities—Urban Density, Trees, and Health

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    A move towards more compact and climate-resilient cities is being encouraged around the world. As part of these plans, there is a need to manage the potential conflict between increasing urban densities and the extent of tree canopy in cities. Reductions in tree canopy are a major contributor to the urban heat island (UHI) effect, which will act to reduce rather than increase climate resilience in many cities. A systems thinking approach called Collaborative Conceptual Modelling was used to study the interaction between urban infill, tree canopy, and human health in Perth, Australia. The results indicated that under current planning policies and development practices, the behaviour of the system is dominated by the drive towards higher housing densities. While this may result in the attainment of urban infill targets, it is likely to lead to a reduction in tree canopy, higher temperatures, and a decrease in a range of other benefits provided by trees. Recommended actions to overcome this behaviour were determined by the identification of leverage points in the system. These included a shift to a sustainable development paradigm that places greater value on the environmental and social benefits provided by trees and a greater emphasis on a climate-resilient future. Market and legislative mechanisms should be integrated into the city’s greening strategy and development plans to ensure the protection of existing trees and the inclusion of new trees on public and private land.This research was funded by CSIRO Urbanism, Climate Adaptation and Health Research Cluster. H.B. was supported by an Australian Postgraduate Award and a Curtin University Postgraduate Scholarship

    Design and Lessons Learned on the Development of a Cryogenic Pupil Select Mechanism (PSM)

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    Calibration and testing of the instruments on the Integrated Science Instrument Module (ISIM) of the James Webb Space Telescope (JWST) is being performed by the use of a cryogenic, full-field, optical simulator that was constructed for this purpose. The Pupil Select Mechanism (PSM) assembly is one of several mechanisms and optical elements that compose the Optical Telescope Element SIMulator, or OSIM. The PSM allows for several optical elements to be inserted into the optical plane of OSIM, introducing a variety of aberrations, distortions, obscurations, and other calibration states into the pupil plane. The following discussion focuses on the details of the design evolution, analysis, build, and test of this mechanism along with the challenges associated with creating a sub arc-minute positioning mechanism operating in an extreme cryogenic environment. In addition, difficult challenges in the control system design will be discussed including the incorporation of closed-loop feedback control into a system that was designed to operate in an open-loop fashion

    A global fit to determine the pseudoscalar mixing angle and the gluonium content of the eta' meson

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    We update the values of the eta-eta' mixing angle and of the eta' gluonium content by fitting our measurement R_phi = BR(phi to eta' gamma)/ BR(phi to eta gamma) together with several vector meson radiative decays to pseudoscalars (V to P gamma), pseudoscalar mesons radiative decays to vectors (P to V gamma) and the eta' to gamma gamma, pi^0 to gamma gamma widths. From the fit we extract a gluonium fraction of Z^2_G = 0.12 +- 0.04, the pseudoscalar mixing angle psi_P = (40.4 +- 0.6) degree and the phi-omega mixing angle psi_V = (3.32 +- 0.09) degree. Z^2_G and psi_P are fairly consistent with those previously published. We also evaluate the impact on the eta' gluonium content determination of future experimental improvements of the eta' branching ratios and decay width.Comment: 13 pages, 7 figures to submit to JHE
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