2,400 research outputs found

    Application of shock tubes to transonic airfoil testing at high Reynolds numbers

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    Performance analysis of a gas-driven shock tube shows that transonic airfoil flows with chord Reynolds numbers of the order of 100 million can be produced, with limitations being imposed by the structural integrity of the facility or the model. A study of flow development over a simple circular arc airfoil at zero angle of attack was carried out in a shock tube at low and intermediate Reynolds numbers to assess the testing technique. Results obtained from schlieren photography and airfoil pressure measurements show that steady transonic flows similar to those produced for the same airfoil in a wind tunnel can be generated within the available testing time in a shock tube with properly contoured test section walls

    Une offre de services adaptée aux chercheurs

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    Ayant l'un des groupes de lecteurs les plus exigeants dans le monde scientifique et des ressources comparables à celles d'une collection de moyenne bibliothèque universitaire, le Service de l'Information Scientifique du CERN utilise toute sa créativité pour ne pas disparaître entre l'offre et la demande. Le CERN a pour but d'être un centre d'excellence dans le domaine de la physique des hautes energies et des technologies connexes. Le Service d'Information Scientifique réalise cet objectif en préservant la mémoire des développements de la physique et en appliquant les technologies avancées des sciences de l'information et du commerce électronique

    Impact of Solar Control PVB Glass on Vehicle Interior Temperatures, Air-Conditioning Capacity, Fuel Consumption, and Vehicle Range

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    The objective of the study was to assess the impact of Saflex1 S-series Solar Control PVB (polyvinyl butyral) configurations on conventional vehicle fuel economy and electric vehicle (EV) range. The approach included outdoor vehicle thermal soak testing, RadTherm cool-down analysis, and vehicle simulations. Thermal soak tests were conducted at the National Renewable Energy Laboratory's Vehicle Testing and Integration Facility in Golden, Colorado. The test results quantified interior temperature reductions and were used to generate initial conditions for the RadTherm cool-down analysis. The RadTherm model determined the potential reduction in air-conditioning (A/C) capacity, which was used to calculate the A/C load for the vehicle simulations. The vehicle simulation tool identified the potential reduction in fuel consumption or improvement in EV range between a baseline and modified configurations for the city and highway drive cycles. The thermal analysis determined a potential 4.0% reduction in A/C power for the Saflex Solar PVB solar control configuration. The reduction in A/C power improved the vehicle range of EVs and fuel economy of conventional vehicles and plug-in hybrid electric vehicles

    Prevalence of Motorcycle Helmet Use in Kathmandu, Nepal: An Observational Study

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    This study investigated the rate of helmet use among motorcycle drivers and passengers in Kathmandu, Nepal during the Fall of 2016, and compared helmet use rates based on highways, main roads and secondary roads in the city. The study design involved cross-sectional observations along roadways in Kathmandu, Nepal. The following variables were studied: helmet use, gender, age category (youth, adult, elder), and type of road (highway, main road, secondary road). Statistical analysis included general behavioral prevalence, relationship comparison via Fisher’s Exact Test, and odds ratios. A total of 1878 observations were made at 14 locations in Kathmandu; n=1321 observations of motorcycle drivers and n=557 observations of motorcycle passengers. Nearly all drivers used helmets (0.994 [1313/1321]; 95% CI: [0.988, 0.997]), whereas the vast majority of passengers did not wear helmets (0.014 [8/557]; 95% CI: [0.004, 0.021]). Helmet use was significantly different between drivers and passengers

    The learning experiences of health and social care paraprofessionals on a foundation degree

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    Foundation degrees have been developed in the UK as a means of meeting the learning needs of paraprofessionals in health and social care and the services within which they work in a cost-effective fashion. Workplace learning is an intrinsic component to these degrees. Taking a socio-cultural perspective, this paper examines how the students' workplaces, life circumstances and sense of career trajectory shaped their learning experience and motivation. A small-scale evaluation study, using semi-structured interviews, focused on the learning experiences of a group of paraprofessionals enrolled in a foundation degree in health and social care. Data revealed fragmented employment patterns, underpinned by consistent vocational drives. While the study resonated with vocation, participants were ambivalent or lacked information about career progression. Workplace conditions, relationships and limited time shaped learning and coping strategies. A strategic and focused approach to student learning is required and includes attention to career pathways, workforce development strategy, the requirements of a range of stakeholders, workplace supervision and support for learning

    Characterization of the JWST Pathfinder Mirror Dynamics Using the Center of Curvature Optical Assembly (CoCOA)

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    The JWST (James Webb Space Telescope) Optical Telescope Element (OTE) consists of a 6.6 meter clear aperture, 18-segment primary mirror, all-reflective, three-mirror anastigmat operating at cryogenic temperatures. To verify performance of the primary mirror, a full aperture center of curvature optical null test is performed under cryogenic conditions in Chamber A at NASA Johnson Space Center using an instantaneous phase measuring interferometer. After phasing the mirrors during the JWST Pathfinder testing, the interferometer is utilized to characterize the mirror relative piston and tilt dynamics under different facility configurations. The correlation between the motions seen on detectors at the focal plane and the interferometer validates the use of the interferometer for dynamic investigations. The success of planned test hardware improvements will be characterized by the multi-wavelength interferometer (MWIF) at the Center of Curvature Optical Assembly (CoCOA)

    Orchestration of renewable generation in low energy buildings and districts using energy storage and load shaping

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    There is increasing penetration of renewable generation in buildings and districts. There are challenges in making the effective use of this generation. The objective of the ORIGIN project (Orchestration of Renewable Integrated Generation In Neighborhoods) is to shape loads so that the fraction of energy consumed that is from local renewable generation is maximized, and energy imported from outside sources is minimized. This paper presents the overall approach taken in the ORIGIN project and explores building physics aspects of solar thermal storage system orchestration. The case study districts are briefly introduced and characteristics of their generation, buildings, districts and shiftable loads described. The orchestration approach taken in ORIGIN is then presented. At the core of the ORIGIN system is the orchestration algorithm which generates informational and control outputs to shape future loads to best meet the objectives. The model based approach used to quantify thermal and electrical load shifting opportunities for pre-charging, coasting or avoiding loads, while meeting thermal comfort and other demands, is described using a solar thermal storage system as an example. The future steps for the ORIGIN project; retrofit of the ORIGIN system into existing districts and potential for other future applications is briefly discussed

    The Otterbein Miscellany - December 1976

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    https://digitalcommons.otterbein.edu/miscellany/1020/thumbnail.jp

    Lowered sensitivity of bitter taste receptors to β-glucosides in bamboo lemurs: an instance of parallel and adaptive functional decline in TAS2R16?

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    竹食サル類の苦味感覚の進化を解明 --竹が先か苦味が先か--. 京都大学プレスリリース. 2021-04-16.Bitter taste facilitates the detection of potentially harmful substances and is perceived via bitter taste receptors (TAS2Rs) expressed on the tongue and oral cavity in vertebrates. In primates, TAS2R16 specifically recognizes β-glucosides, which are important in cyanogenic plants' use of cyanide as a feeding deterrent. In this study, we performed cell-based functional assays for investigating the sensitivity of TAS2R16 to β-glucosides in three species of bamboo lemurs (Prolemur simus, Hapalemur aureus and H. griseus), which primarily consume high-cyanide bamboo. TAS2R16 receptors from bamboo lemurs had lower sensitivity to β-glucosides, including cyanogenic glucosides, than that of the closely related ring-tailed lemur (Lemur catta). Ancestral reconstructions of TAS2R16 for the bamboo-lemur last common ancestor (LCA) and that of the Hapalemur LCA showed an intermediate sensitivity to β-glucosides between that of the ring-tailed lemurs and bamboo lemurs. Mutagenetic analyses revealed that P. simus and H. griseus had separate species-specific substitutions that led to reduced sensitivity. These results indicate that low sensitivity to β-glucosides at the cellular level-a potentially adaptive trait for feeding on cyanogenic bamboo-evolved independently after the Prolemur-Hapalemur split in each species
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