100 research outputs found

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

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    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

    Design of Three-Dimensional Hypersonic Inlets with Rectangular to Elliptical Shape Transition

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    A methodology has been devised for the design of three-dimensional hypersonic inlets which include a rectangular to elliptical shape transition. This methodology makes extensive use of inviscid streamtracing techniques to generate a smooth shape transition from a rectangular-like capture to an elliptical throat. Highly swept leading edges and a significantly notched cowl enable use of these inlets in fixed geometry configurations. The design procedure includes a three dimensional displacement thickness calculation and uses established correlations to check for boundary layer separation due to shock wave interactions. Complete details of the design procedure are presented and the characteristics of a modular inlet with rectangular to elliptical shape transition and a design point of Mach 7.1 are examined. Comparison with a classical two-dimensional inlet optimized for maximum total pressure recovery indicates that this three-dimensional inlet demonstrates good performance even well below its design point

    Strafvorderlijke gegevensverwerking

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    As a result of society’s increasing digitisation, the police have ever more opportunities to collect, investigate and combine huge amounts of personal data using advanced technology. Examples are provided from recent cases where police have gained access to millions of encrypted messages from various servers, including Ennetcom, EncroChat and Sky Global. However, the current legal framework is, as yet, ill-equipped to deal with this new reality. Partly for this reason, legislators are facing new questions about how the (further) processing of data in detection should be regulated by law. Commissioned by the WODC, this study examines the legal safeguards in criminal justice data collection in relation to the legal safeguards governing the processing of these data. The Code of Criminal Procedure mainly focuses on the collection of data and to a much lesser extent on its further use, but this may involve a (fresh) invasion of citizens’ privacy. The Police Data Act contains some provisions to data processing, but the relationship with the Dutch Code of Criminal Procedure is not entirely clear. This study identifies the requirements and safeguards under European law for the processing of data for criminal justice purposes. Further inspiration is drawn from experience with the Intelligence and Security Services Act 2017 in which powers of collection and (further) processing are regulated in a single law. Finally, it explores how, in several countries (Germany, Belgium and Norway), the requirements arising from European law have been translated into legal regulations and how these regulations are designed. This study provides tools that legislators can use to reconsider the methods of standardisation and legal regulation design to better protect citizens' privacy. The recommendations thus focus on strengthening the legal framework on data processing and its supervision by creating an explicit legal framework in the Code of Criminal Procedure and establishing an independent supervisor focused on the processing of personal data by investigative authorities

    Strafvorderlijke gegevensverwerking

    Get PDF
    As a result of society’s increasing digitisation, the police have ever more opportunities to collect, investigate and combine huge amounts of personal data using advanced technology. Examples are provided from recent cases where police have gained access to millions of encrypted messages from various servers, including Ennetcom, EncroChat and Sky Global. However, the current legal framework is, as yet, ill-equipped to deal with this new reality. Partly for this reason, legislators are facing new questions about how the (further) processing of data in detection should be regulated by law. Commissioned by the WODC, this study examines the legal safeguards in criminal justice data collection in relation to the legal safeguards governing the processing of these data. The Code of Criminal Procedure mainly focuses on the collection of data and to a much lesser extent on its further use, but this may involve a (fresh) invasion of citizens’ privacy. The Police Data Act contains some provisions to data processing, but the relationship with the Dutch Code of Criminal Procedure is not entirely clear. This study identifies the requirements and safeguards under European law for the processing of data for criminal justice purposes. Further inspiration is drawn from experience with the Intelligence and Security Services Act 2017 in which powers of collection and (further) processing are regulated in a single law. Finally, it explores how, in several countries (Germany, Belgium and Norway), the requirements arising from European law have been translated into legal regulations and how these regulations are designed. This study provides tools that legislators can use to reconsider the methods of standardisation and legal regulation design to better protect citizens' privacy. The recommendations thus focus on strengthening the legal framework on data processing and its supervision by creating an explicit legal framework in the Code of Criminal Procedure and establishing an independent supervisor focused on the processing of personal data by investigative authorities

    Climate control of terrestrial carbon exchange across biomes and continents

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    Peer reviewe

    Natural Food: Organizing ‘responsiveness’ in responsible innovation of food technology

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    Responsible innovation requires mutual responsiveness between various stakeholders around technological innovation. But in public engagement exercises, concerns about ethical, cultural and political impacts are too easily set aside, so that no one is actually encouraged to discuss responsibilities for these impacts. A typical example in the field of food innovation is the consumer’s recurring concern for natural food. In discussions, both consumers and engineers tend to consider the meaning of naturalness as subjective and private. In this chapter, we present an interdisciplinary design tool for public engagement that is more hospitable to such concerns, based on the Discursive Action Method and Techno- Ethical Imagination. We describe the advancements we made and the obstacles we faced when applying this tool in two dialogue workshops on novel foods and naturalness

    Hemidesmosomes modulate force generation via focal adhesions

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    Biological and Soft Matter Physic
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