113 research outputs found
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Status report on SHARP coupling framework.
This report presents the software engineering effort under way at ANL towards a comprehensive integrated computational framework (SHARP) for high fidelity simulations of sodium cooled fast reactors. The primary objective of this framework is to provide accurate and flexible analysis tools to nuclear reactor designers by simulating multiphysics phenomena happening in complex reactor geometries. Ideally, the coupling among different physics modules (such as neutronics, thermal-hydraulics, and structural mechanics) needs to be tight to preserve the accuracy achieved in each module. However, fast reactor cores in steady state mode represent a special case where weak coupling between neutronics and thermal-hydraulics is usually adequate. Our framework design allows for both options. Another requirement for SHARP framework has been to implement various coupling algorithms that are parallel and scalable to large scale since nuclear reactor core simulations are among the most memory and computationally intensive, requiring the use of leadership-class petascale platforms. This report details our progress toward achieving these goals. Specifically, we demonstrate coupling independently developed parallel codes in a manner that does not compromise performance or portability, while minimizing the impact on individual developers. This year, our focus has been on developing a lightweight and loosely coupled framework targeted at UNIC (our neutronics code) and Nek (our thermal hydraulics code). However, the framework design is not limited to just using these two codes
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Status report on high fidelity reactor simulation.
This report presents the effort under way at Argonne National Laboratory toward a comprehensive, integrated computational tool intended mainly for the high-fidelity simulation of sodium-cooled fast reactors. The main activities carried out involved neutronics, thermal hydraulics, coupling strategies, software architecture, and high-performance computing. A new neutronics code, UNIC, is being developed. The first phase involves the application of a spherical harmonics method to a general, unstructured three-dimensional mesh. The method also has been interfaced with a method of characteristics. The spherical harmonics equations were implemented in a stand-alone code that was then used to solve several benchmark problems. For thermal hydraulics, a computational fluid dynamics code called Nek5000, developed in the Mathematics and Computer Science Division for coupled hydrodynamics and heat transfer, has been applied to a single-pin, periodic cell in the wire-wrap geometry typical of advanced burner reactors. Numerical strategies for multiphysics coupling have been considered and higher-accuracy efficient methods proposed to finely simulate coupled neutronic/thermal-hydraulic reactor transients. Initial steps have been taken in order to couple UNIC and Nek5000, and simplified problems have been defined and solved for testing. Furthermore, we have begun developing a lightweight computational framework, based in part on carefully selected open source tools, to nonobtrusively and efficiently integrate the individual physics modules into a unified simulation tool
Fatigue strength of common tibial intramedullary nail distal locking screws
Premature failure of either the nail and/or locking screws with unstable fracture patterns may lead to angulation, shortening, malunion, and IM nail migration. Up to thirty percent of all unreamed nail locking screws can break after initial weight bearing is allowed at 8–10 weeks if union has not occurred. The primary problem this presents is hardware removal during revision surgery. The purposes of our study was to evaluate the relative fatigue resistance of distal locking screws and bolts from representative manufacturers of tibial IM nail systems, and develop a relative risk assessment of screws and materials used. Evaluations included quantitative and qualitative measures of the relative performance of these screws
Building an Aerial-Ground Robotics System for Precision Farming: An Adaptable Solution
[No abstract available
Perspectives of Portuguese People with Physical Disabilities Regarding Their Sexual Health: A Focus Group Study
The World Health Organization has considered sexual health as a major dimension of global health and a sexual right. However, the sexual health of people with physical disabilities is still poorly addressed by health and social care professionals, and it is very stigmatized by society. This study aimed to assess the perspectives of Portuguese people living with physical disabilities regarding issues affecting their sexual health. Nine women and 17 men with different physical disabilities participated in the study. Participants were recruited from a professional rehabilitation facility located in the North of Portugal and were assigned to four groups in one-hour sessions. Three main categories emerged from the content analysis: (1) meanings and beliefs regarding sexuality; (2) experiences of sexuality; (3) necessary changes. Despite the positive social changes towards sexuality, participants expressed that their sexual rights are still unfulfilled, as they live in a context that perpetuates their dependency. They pointed out low self-esteem, prejudice and social isolation, poor architectural accessibility and scarcity of financial support as some of the barriers to their lives and their sexual health. Finally, participants identified the main needs regarding their sexual health, such as: access to specialized information; training for health professionals. This study gives voice to people with physical disabilities and sheds light into both individual and contextual factors affecting their sexual health. Of utmost importance, this study draws attention to the need for reinforcing sexuality of people with disabilities in the social agenda and brings implications for future research and practice.This study was supported by a Grant attributed to the first author by the Portuguese Foundation for Science and Technology (SFRH/BD/112168/2015)info:eu-repo/semantics/publishedVersio
Mesozoic Alpine facies deposition as a result of past latitudinal plate motion
The fragmentation of Pangaea as a consequence of the opening of the Atlantic Ocean is documented in the Alpine-Mediterranean region by the onset of widespread pelagic sedimentation1. Shallow-water sediments were replaced by mainly pelagic limestones in the Early Jurassic period, radiolarian cherts in the Middle-Late Jurassic period, and again pelagic limestones in the Late Jurassic-Cretaceous period. During initial extension, basin subsidence below the carbonate compensation depth (CCD) is thought to have triggered the transition from Early Jurassic limestones to Middle-Late Jurassic radiolarites. It has been proposed that the transition from radiolarites to limestones in the Late Jurassic period was due to an increase in calcareous nannoplankton abundance when the CCD was depressed below the ocean floor. But in modern oceans, sediments below the CCD are not necessarily radiolaritic. Here we present palaeomagnetic samples from the Jurassic-Cretaceous pelagic succession exposed in the Lombardian basin, Italy. On the basis of an analysis of our palaeolatitudinal data in a broader palaeogeographic context, we propose an alternative explanation for the above facies tripartition. We suggest that the Lombardian basin drifted initially towards, and subsequently away from, a near-equatorial upwelling zone of high biosiliceous productivity. Our tectonic model for the genesis of radiolarites adds an essential horizontal plate motion component to explanations involving only vertical variations of CCD relative to the ocean floor. It may explain the deposition of radiolarites throughout the Mediterranean and Middle Eastern region during the Jurassic period
Gardens of happiness: Sir William Temple, temperance and China
This is the author accepted manuscript. The final version is available from Taylor & Francis via the DOI in this recordSir William Temple, an English statesman and humanist, wrote “Upon the
Gardens of Epicurus” in 1685, taking a neo-epicurean approach to happiness
and temperance. In accord with Pierre Gassendi’s epicureanism, “happiness” is
characterised as freedom from disturbance and pain in mind and body, whereas
“temperance” means following nature (Providence and one’s physiopsychological constitution). For Temple, cultivating fruit trees in his garden was
analogous to the threefold cultivation of temperance as a virtue in the humoral
body (as food), the mind (as freedom from the passions), and the bodyeconomic (as circulating goods) in order to attain happiness. A regimen that was
supposed to cure the malaise of Restoration amidst a crisis of unbridled
passions, this threefold cultivation of temperance underlines Temple’s reception
of China and Confucianism wherein happiness and temperance are highlighted.
Thus Temple’s “gardens of happiness” represent not only a reinterpretation of
classical ideas, but also his dialogue with China.European CommissionLeverhulme Trus
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