120 research outputs found
Engine component instrumentation development facility at NASA Lewis Research Center
The Engine Components Instrumentation Development Facility at NASA Lewis is a unique aeronautics facility dedicated to the development of innovative instrumentation for turbine engine component testing. Containing two separate wind tunnels, the facility is capable of simulating many flow conditions found in most turbine engine components. This facility's broad range of capabilities as well as its versatility provide an excellent location for the development of novel testing techniques. These capabilities thus allow a more efficient use of larger and more complex engine component test facilities
A Supersonic Tunnel for Laser and Flow-Seeding Techniques
A supersonic wind tunnel with flow conditions of 3 lbm/s (1.5 kg/s) at a free-stream Mach number of 2.5 was designed and tested to provide an arena for future development work on laser measurement and flow-seeding techniques. The hybrid supersonic nozzle design that was used incorporated the rapid expansion method of propulsive nozzles while it maintained the uniform, disturbance-free flow required in supersonic wind tunnels. A viscous analysis was performed on the tunnel to determine the boundary layer growth characteristics along the flowpath. Appropriate corrections were then made to the contour of the nozzle. Axial pressure distributions were measured and Mach number distributions were calculated based on three independent data reduction methods. A complete uncertainty analysis was performed on the precision error of each method. Complex shock-wave patterns were generated in the flow field by wedges mounted near the roof and floor of the tunnel. The most stable shock structure was determined experimentally by the use of a focusing schlieren system and a novel, laser based dynamic shock position sensor. Three potential measurement regions for future laser and flow-seeding studies were created in the shock structure: deceleration through an oblique shock wave of 50 degrees, strong deceleration through a normal shock wave, and acceleration through a supersonic expansion fan containing 25 degrees of flow turning
Scale-Space Splatting: Reforming Spacetime for the Cross-Scale Exploration of Integral Measures in Molecular Dynamics
Understanding large amounts of spatiotemporal data from particle-based
simulations, such as molecular dynamics, often relies on the computation and
analysis of aggregate measures. These, however, by virtue of aggregation, hide
structural information about the space/time localization of the studied
phenomena. This leads to degenerate cases where the measures fail to capture
distinct behaviour. In order to drill into these aggregate values, we propose a
multi-scale visual exploration technique. Our novel representation, based on
partial domain aggregation, enables the construction of a continuous
scale-space for discrete datasets and the simultaneous exploration of scales in
both space and time. We link these two scale-spaces in a scale-space space-time
cube and model linked views as orthogonal slices through this cube, thus
enabling the rapid identification of spatio-temporal patterns at multiple
scales. To demonstrate the effectiveness of our approach, we showcase an
advanced exploration of a protein-ligand simulation.Comment: 11 pages, 9 figures, IEEE SciVis 201
Digitization or digitalization? – Toward an understanding of definitions, use and application in IS research
The global cropland footprint of the non-food bioeconomy. ZEF - Discussion Papers on Development Policy No. 253
A rapidly growing share of global agricultural areas is devoted to the production of biomass
for non
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food purposes. The derived products include, for example, biofuels, textiles,
detergents or c
osmetics. Given the far
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reaching global implications of an expanding non
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food bioeconomy, an assessment of the bioeconomy's resource use from a footprint
perspective is urgently needed. We determine the global cropland footprint of non
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food
products with a
hybrid land flow accounting model combining data from the Food and
Agriculture Organization and the multi
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regional input
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output model EXIOBASE. The globally
interlinked model covers all cropland areas used for the production of crop
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and animal
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based non
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food commodities for the years from 1995 to 2010. We analyse global patterns of
raw material producers, processers and consumers of bio-based non-food products, with a
particular focus on the European Union. Results illustrate that the EU is a major processer and the number one consumer region of non-food cropland, despite being only the fifth
largest producing region. Two thirds of the cropland required to satisfy EU non-food consumption are located in other world regions, giving rise to a significant depe
ndency on
imported products and to potential impacts on distant ecosystems. With almost 29% in
2010, oilseed production, used to produce, for example, biofuels, detergents and polymers,
represents the dominant share in the EU's non-food cropland footprint.
There is also a significant contribution of more traditional non-food biomass uses such as fibre crops (for textiles) and animal hides and skins (for leather products). Our study emphasises the
importance of comprehensively assessing the implications of the non-food bioeconomy
expansion as envisaged in various policy strategies, such as the Bioeconomy Strategy of the European Commission
FABIO - The Construction of the Food and Agriculture Biomass Input-Output Model
Primary crops are linked to final consumption by networks of processes and actors that convert and distribute food and non-food goods. Achieving a sustainable metabolism of this bio-economy is an overarching challenge which manifests itself in a number of the UN Sustainable Development Goals. Modelling the physical dimensions of biomass conversion and distribution networks is essential to understanding the characteristics, drivers and dynamics of our societies' biomass metabolism. In this paper, we present the Food and Agriculture Biomass Input-Output model (FABIO), a set of multi-regional supply, use and input-output tables in physical units, that document the complex flows of agricultural and food products in the global economy. The model assembles FAOSTAT statistics reporting crop production, trade, and utilisation in physical units, supplemented by data on technical and metabolic conversion efficiencies, into a consistent, balanced, input-output framework. FABIO covers 191 countries and 130 agriculture, food and forestry products from 1986 to 2013. The physical supply-use tables offered by FABIO provide a comprehensive, transparent and flexible structure for organising data representing flows of materials within metabolic networks.
They allow tracing biomass flows and embodied environmental pressures along global supply chains at an unprecedented level of product and country detail and can help to answer a range of questions regarding environment, agriculture, and trade.Series: Ecological Economic Paper
Chemical characterization of 21 species of marine macroalgae common in Norwegian waters: benefits of and limitations to their potential use in food and feed
BACKGROUND: In the past few years, much effort has been invested into developing a new blue economy based on harvesting, cultivating and processing marine macroalgae in Norway. Macroalgae have high potential for a wide range of applications, e.g. as source of pharmaceuticals, production of biofuels or as food and feed. However, data on the chemical composition of macroalgae from Norwegian waters are scant. This study was designed to characterize the chemical composition of 21 algal species. Both macro- and micronutrients were analysed. Concentrations of heavy metals and the metalloid arsenic in the algae were also quantified. RESULTS: The results confirm that marine macroalgae contain nutrients which are relevant for both human and animal nutrition, the concentrations whereof are highly dependent on species. Although heavy metals and arsenic were detected in the algae studied, concentrations were mostly below maximum allowed levels set by food and feed legislation in the EU. CONCLUSION: This study provides chemical data on a wide range of algal species covering the three taxonomic groups (brown, red and green algae) and discusses both benefits of and potential limitations to their use for food and feed purposes.Chemical characterization of 21 species of marine macroalgae common in Norwegian waters: benefits of and limitations to their potential use in food and feedpublishedVersio
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