Publications associées à National Aeronautics and Space Administration

Use of lidar aerosol extinction and backscatter coefficients to estimate cloud condensation nuclei (CCN) concentrations in the southeast Atlantic

Accurately capturing cloud condensation nuclei (CCN) concentrations is key to understanding the aerosol-cloud interactions that continue to feature the highest uncertainty amongst numerous climate forcings. In situ CCN observations are sparse, and most non ...

COPERNICUS GESELLSCHAFT MBH2023

H∞ and μ-Synthesis for Nanosatellites Rendezvous and Docking

Volker Gass, Camille Sébastien Pirat

In this brief, the nanosatellite rendezvous and docking problem is tackled. It was never attempted for small spacecraft, as critical technologies, such as six-degree-of-freedom (DoF) micropropulsion systems, have only recently become available due to advan ...

2019

Inferring Accurate Bus Trajectories from Noisy Estimated Arrival Time Records

Lakmal Buddika Meegahapola

Urban commuting data has long been a vital source of understanding population mobility behaviour and has been widely adopted for various applications such as transport infrastructure planning and urban anomaly detection. While individual-specific transacti ...

IEEE2019

3D Laser Shock Peening – A new method for the 3D control of residual stresses in Selective Laser Melting

Roland Logé, Jamasp Jhabvala, Christian Leinenbach, Eric Boillat, Nikola Kalentics

This paper describes a hybrid additive manufacturing process – 3D Laser Shock Peening (3D LSP), based on the integration of Laser Shock Peening (LSP) with selective laser melting (SLM). The well-known tensile residual stresses (TRS) in the as – built (AB) ...

Elsevier Sci Ltd2017

The effects of radiation on ablative heat shields during atmospheric entry

Nikhil Banerji

Spacecraft employ composite materials as Thermal Protection Systems (TPS) to survive entering a planetary atmosphere at hypersonic speeds. Under intense convective and radiative heating from the surrounding shock layer, these composites decompose and erode ...

EPFL2017

Deployment and Performance Analyses of High-Resolution Iowa XPOL Radar System during the NASA IFloodS Campaign

Jacopo Grazioli, Kumar Vijay Mishra

This article presents the data collected and analyzed using the University of Iowa's X-band polarimetric (XPOL) radars that were part of the spring 2013 hydrology-oriented Iowa Flood Studies (IFloodS) field campaign, sponsored by NASA's Global Precipitatio ...

American Meteorological Society2016

Rollable Multisegment Dielectric Elastomer Minimum Energy Structures for a Deployable Microsatellite Gripper

Herbert Shea, Volker Gass, Samuel Rosset, Jun Shintake, Muriel Richard, Irina Gavrilovich, Oluwaseun Adelowo Araromi

Debris in space presents an ever-increasing problem for spacecraft in Earth orbit. As a step in the mitigation of this issue, the CleanSpace One (CSO) microsatellite has been proposed. Its mission is to perform active debris removal of a decommissioned nan ...

Ieee-Inst Electrical Electronics Engineers Inc2015

Sequestration, Scholarship, Sentinel: The Post-Politics of Peace (and War)

Nikolas Kosmatopoulos

n Lebanon, diverse sociopolitical projects have sought to mend the wounds, repair the cracks, and overhaul the loss of the devastating civil war (1975–90). Experts and technopolitics have featured centrally in almost all of them. In my anthropological rese ...

Cambridge University Press2014

Probing the z> 6 universe with the first Hubble frontier fields cluster A2744

Jean-Paul Richard Kneib, Hakim Atek, Benjamin Yvan Alexandre Clement, Mathilde Jauzac, Johan Richard

The Hubble Frontier Fields program combines the capabilities of the Hubble Space Telescope (HST) with the gravitational lensing of massive galaxy clusters to probe the distant universe to an unprecedented depth. Here, we present the results of the first co ...

American Astronomical Society2014

Détection vibratoire de l'érosion de cavitation des turbines Francis

Cavitation erosion of Francis turbines continues to impose costly repairs and loss of revenues. This erosion is primarily caused by leading edge cavitation. A revue of the literature reveals the non-existence of an absolutely validated detection technique ...

EPFL2000