36,131 research outputs found
Planned Adaptation in Design and Testing of Critical Infrastructure: The Case of Flood Safety in The Netherlands
In the Netherlands, dykes and other primary water defence works are assets that are essential to keep the society and economy functioning, by protecting against flooding from sea and rivers due to extreme events. Given that 55% of the country is at risk of flooding, primary water defence works belong to its critical infrastructure. Many factors influence the risk and impact of flooding. Besides physical factors (e.g., landscape design, climate change) also socio-economic factors (e.g., population, assets) are important. Given that these factors change and feature complex and uncertain behaviour in past and future, the design and regulation of this critical infrastructure will have to be flexible enough to be able to deal with such changes. ‘Planned Adaptation’ refers to regulatory programmes that plan for future changes in knowledge by producing new knowledge and revising rules at regular intervals. This study describes the emergence of the next generation of Dutch primary water defence infrastructure, which through the stepwise implementation of Planned Adaptation for design and testing of primary water defence works in the mid-1990s has moved beyond the Delta Works approach of 1953 and subsequent unplanned adaptations. This has prepared the ground for the recent introduction of Adaptive Delta Management, which makes an integral part of the new Delta Plan for the Netherlands that was published on 16 September 2014 and which is also analysed in this study
Eccentricity fluctuations in an integrated hybrid approach: Influence on elliptic flow
The effects of initial state fluctuations on elliptic flow are investigated
within a (3+1)d Boltzmann + hydrodynamics transport approach. The spatial
eccentricity ( and ) is calculated for
initial conditions generated by a hadronic transport approach (UrQMD). Elliptic
flow results as a function of impact parameter, beam energy and transverse
momentum for two different equations of state and for averaged initial
conditions or a full event-by-event setup are presented. These investigations
allow the conclusion that in mid-central ( fm) heavy ion collisions the
final elliptic flow is independent of the initial state fluctuations and the
equation of state. Furthermore, it is demonstrated that most of the is
build up during the hydrodynamic stage of the evolution. Therefore, the use of
averaged initial profiles does not contribute to the uncertainties of the
extraction of transport properties of hot and dense QCD matter based on viscous
hydrodynamic calculations.Comment: 7 pages, 7 figures, minor revision of figures and conclusion, as
published in PR
Design challenges for space bioreactors
The design of bioreactors for operation under conditions of microgravity presents problems and challenges. Absence of a significant body force such as gravity can have profound consequences for interfacial phenomena. Marangoni convection can no longer be overlooked. Many speculations on the advantages and benefits of microgravity can be found in the literature. Initial bioreactor research considerations for space applications had little regard for the suitability of the designs for conditions of microgravity. Bioreactors can be classified in terms of their function and type of operation. The complex interaction of parameters leading to optimal design and operation of a bioreactor is illustrated by the JSC mammalian cell culture system. The design of a bioreactor is strongly dependent upon its intended use as a production unit for cell mass and/or biologicals or as a research reactor for the study of cell growth and function. Therefore a variety of bioreactor configurations are presented in rapid summary. Following this, a rationale is presented for not attempting to derive key design parameters such as the oxygen transfer coefficient from ground-based data. A set of themes/objectives for flight experiments to develop the expertise for design of space bioreactors is then proposed for discussion. These experiments, carried out systematically, will provide a database from which engineering tools for space bioreactor design will be derived
Cardiovascular MRI in clinical trials: expanded applications through novel surrogate endpoints
Recent advances in cardiovascular magnetic resonance (CMR) now allow the accurate and reproducible measurement of many aspects of cardiac and vascular structure and function, with prognostic data emerging for several key imaging biomarkers. These biomarkers are increasingly used in the evaluation of new drugs, devices and lifestyle modifications for the prevention and treatment of cardiovascular disease. This review outlines a conceptual framework for the application of imaging biomarkers to clinical trials, highlights several important CMR techniques which are in use in randomised studies, and reviews certain aspects of trial design, conduct and interpretation in relation to the use of CMR
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