Uncertainty Evaluation of Computational Model Used to Support the Integrated Powerhead Demonstration Project

NASA and the U.S. Air Force are working on a joint project to develop a new hydrogen-fueled, full-flow, staged combustion rocket engine. The initial testing and modeling work for the Integrated Powerhead Demonstrator (IPD) project is being performed by NASA Marshall and Stennis Space Centers. A key factor in the testing of this engine is the ability to predict and measure the transient fluid flow during engine start and shutdown phases of operation. A model built by NASA Marshall in the ROCket Engine Transient Simulation (ROCETS) program is used to predict transient engine fluid flows. The model is initially calibrated to data from previous tests on the Stennis E1 test stand. The model is then used to predict the next run. Data from this run can then be used to recalibrate the model providing a tool to guide the test program in incremental steps to reduce the risk to the prototype engine. In this paper, they define this type of model as a calibrated model. This paper proposes a method to estimate the uncertainty of a model calibrated to a set of experimental test data. The method is similar to that used in the calibration of experiment instrumentation. For the IPD example used in this paper, the model uncertainty is determined for both LOX and LH flow rates using previous data. The successful use of this model is then demonstrated to predict another similar test run within the uncertainty bounds. The paper summarizes the uncertainty methodology when a model is continually recalibrated with new test data. The methodology is general and can be applied to other calibrated models

Greenhouse gas emissions in The Netherlands 1990-2012 : National Inventory Report 2014

In 2012 is de totale uitstoot van broeikasgassen van Nederland, zoals CO2, methaan en lachgas, met ongeveer 1,7 procent gedaald ten opzichte van 2011. Deze daling komt vooral door een lager brandstofgebruik in de energie- en transportsector. Dit lijkt een gevolg van de economische recessie, waardoor emissies door elektriciteitsproductie en het wegtransport in Nederland zijn afgenomen. Cijfers De totale broeikasgasemissie wordt uitgedrukt in CO2-equivalenten en bedraagt in 2012 191,7 teragram (megaton of miljard kilogram) . Ten opzichte van de uitstoot in het Kyoto-basisjaar (213,2 Tg CO2-equivalenten) is dit een afname van ongeveer 10 procent. Het basisjaar, dat afhankelijk van het broeikasgas 1990 of 1995 is, dient voor het Kyoto-protocol als referentie voor de uitstoot van broeikasgassen. De uitstoot van de overige broeikasgassen zoals lachgas en methaan is sinds het basisjaar met 51 procent afgenomen. De CO2-uitstoot daarentegen is in deze periode met 4 procent gestegen. Landen zijn voor het Kyoto-protocol verplicht om de totale uitstoot van broeikasgassen op twee manieren te rapporteren: met en zonder het soort landgebruik en de verandering daarin. Dit is namelijk van invloed op de uitstoot van broeikasgassen. Voorbeelden zijn natuurontwikkeling (dat CO2 bindt) of ontbossing (waardoor CO2 wordt uitgestoten). In bovengenoemde getallen zijn deze zogeheten LULUCF-emissies (Land Use, Land Use Change and Forestry) niet meegenomen. Overige onderdelen inventarisatie Het RIVM stelt jaarlijks op verzoek van het Ministerie van Infrastructuur en Milieu (IenM) de inventarisatie van broeikasgasemissies op. De inventarisatie bevat trendanalyses om ontwikkelingen in de uitstoot van broeikasgassen tussen 1990 en 2012 te verklaren, en een analyse van de onzekerheid in deze getallen. Ook is aangegeven welke bronnen het meest aan deze onzekerheid bijdragen. Daarnaast biedt de inventarisatie documentatie van de gebruikte berekeningsmethoden, databronnen en toegepaste emissiefactoren. Met deze inventarisatie voldoet Nederland aan de nationale rapportageverplichtingen voor 2012 van het Klimaatverdrag van de Verenigde Naties (UNFCCC), van het Kyoto-Protocol en van het Bewakingsmechanisme Broeikasgassen van de Europese Unie.Total greenhouse gas emissions from the Netherlands in 2012 decreased by approximately 1.7 per cent, compared with 2011 emissions. This decrease is mainly the result of decreased fuel combustion in the Energy sector (increased electricity import) and in road transport. In 2012, total direct greenhouse gas emissions (excluding emissions from LULUCF - land use, land use change and forestry) in the Netherlands amounted to 191.7 Tg CO2 eq. This is approximately 10 per cent below the emissions in the base year (213.2 Tg CO2 eq.). The 51% reduction in the non-CO2 emissions in this period is counterbalanced by 4 per cent increase in CO2 emissions since 1990. This report documents the Netherlands' 2014 annual submission of its greenhouse gas emissions inventory in accordance with the guidelines provided by the United Nations Framework Convention on Climate Change (UNFCCC), the Kyoto Protocol and the European Union's Greenhouse Gas Monitoring Mechanism. The report comprises explanations of observed trends in emissions; a description of an assessment of key sources and their uncertainty; documentation of methods, data sources and emission factors applied; and a description of the quality assurance system and the verification activities performed on the data.Ministerie van I&

Climate control of terrestrial carbon exchange across biomes and continents

Peer reviewe

Turning Experts Into Self-Reflexive Speakers. The Problematization of Technical-Scientific Expertise Relative to Alternative Forms of Expertise

Bio-experts’ portrayals of laypeople are considered problematic. Two discursive action method workshops with 17 participants were organized to discover whether plant experts can engage in reflexive problematization of their own talk about and in front of laypeople and whether plant experts’ analyses may offer insights with regard to the hegemony of technical-scientific expertise. Participants discussed the interactional effects of real-life expert talk. Plant experts’ discussions indicate that they can problematize how their talk-in-interaction helps reproduce the supremacy of technical-scientific expertise. Results also suggest that plant experts may offer complementary insights to social scientists’ analyses of plant experts’ talk

Experimental testing of a hypersonic inlet with rectangular-to-elliptical shape transition

Wind-tunnel testing of a hypersonic inlet with rectangular-to-elliptical shape transition has been conducted at Mach 6.2. These tests were performed to validate the use of a recently developed design methodology for fixed-geometry hypersonic inlets suitable for airframe integrated scramjets. Results indicated that flow features within the inlet were similar to design and that the inlet typically captured 96% of the available airflow. Typical mass-flow-weighted total pressure recoveries of 55% were obtained for compression ratios of 14.8 throughout the test program. Assessment of the inlet starting characteristics indicated that the inlet self-started at Mach 6.2 despite the fact that it had an internal contraction ratio well above the Kantrowitz limit (Kantrowitz, A,, and Donaldson, C., "Preliminary Investigation of Supersonic Diffusers," NACA WR L-713, 1945). These results demonstrate that high-performance, fixed-geometry inlets can be designed to combine a nearly rectangular capture with a smooth transition to an elliptical throat

We say: ‘. . .’, they say: ‘. . .’: How plant science experts draw on reported dialogue to shelve user concerns

This study aims to increase insight into the uses of experts’ references to physically absent technology users in government-funded plant science. A discursive psychological analysis of expert board meetings shows that experts invoke various forms of reported dialogue/thoughts and dispositional statements when problems with technology and with program funding are discussed. Forms of reported dialogue serve to demonstrate that experts engage in dialogue with users, understand and are reasonable about users’ concerns, and that the content of user concerns does not agree with expert views. Dispositional statements allow users’ feelings rather than users’ knowledge to be acknowledged as relevant. By establishing that user concerns contrast with expert concerns in type and content and by not discussing how users’ feelings may be incorporated into technology, experts shelve user concerns. This practice may hinder the development of user-friendly technologies

Healthy eating strategies for socioeconomically disadvantaged populations: a meta-ethnography

© 2021 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.Purpose: In developed countries, diet-related health inequalities between people with different levels of socioeconomic advantage persist. However, there is limited qualitative evidence to inform the design of effective healthy eating (HE) strategies in socioeconomically disadvantaged populations (SDPs). The purpose of this review was to explore the characteristics influencing HE strategies for SDPs and develop a new understanding of how and why they influence their success. Methods: A qualitative evidence synthesis using a systematic meta-ethnographic approach. The twelve studies included were conducted in the USA, Canada, Australia, and UK. Results: The studies described a range of HE strategies, including nutrition education programs, food vouchers, and community gardens. Personal values and sense of pride and autonomy were found to have an influence on participants’ attitudes towards HE strategies. Similarly, social characteristics such as level of social support and opportunities for shared benefits influenced participants’ engagement. Structural characteristics such as the affordability and accessibility of healthy foods determined strategy acceptability and success. Finally, organizational characteristics such as flexibility influenced how well strategies supported the circumstances of participants. Conclusions: These overlapping characteristics may be used to inform the development, implementation, and evaluation of strategies to improve healthy eating in SDPs

Kryogene Infrastruktur bei BESSY II Bestand und Ausblick

Das Helmholtz Zentrum Berlin betreibt am Standort Adlershof u.a. den Elektronenspeicherring BESSY II. Für die Versorgung der im Speicherring installierten supraleitenden Wellenlängenschieber mit Flüssighelium ist ein He liumverflüssiger installiert. Ein weiterer Verflüssiger, inklusive umfassender kryogener Infrastruktur, versorgt mehrere Teststände, vor allem für supraleitende Hohlraumresonatoren, mit Helium bei 1,8 K. Neben dem Betrieb der existierenden Anlagen wird derzeit ein neuartiger Beschleunigertyp im Rahmen des Pro jektes bERLinPro aufgebaut. Um die benötigte Versorgung mit Flüssighelium zu gewährleisten, wird einer der bestehenden Heliumverflüssiger umgezogen sowie die Anlage um u.a. einen 10.000 l Dewar, drei Ventilboxen, eine Kaltkompressorbox, einen warmen Pumpstand und ein 80 K Helium System erweitert. Au erdem ist für das Zukunftsprojekt BESSY VSR, einer Weiterentwicklung des Speicherrings BESSY II, die Be schaffung einer dritten Kälteanlage geplant. Eine Herausforderung hierbei wird der ganzjährig durchgängige Be trieb sein. In diesem Papier wird der Aufbau der oben beschriebenen Anlagen detaillierter erläutert und ein Einblick in die Herausforderungen bei der Anlagenplanung gegeben. Abschlie end werden die geplanten zukünftigen Erweite rungen skizzier