Sökning: "spacecraft potential"
Visar resultat 11 - 15 av 19 avhandlingar innehållade orden spacecraft potential.
11. Investigations of auroral electric fields and currents
Sammanfattning : The Cluster spacecraft have been used to investigate auroral electric fields and field-aligned currents (FACs) at geocentric distances between 4 and 7 Re. The electric fields have been measured by the EFW instrument, consisting of two pairs of spherical probes, and the FACs have been calculated from measurements of the magnetic field by the FGM fluxgate magnetometer. LÄS MER
12. Object-plasma interaction in the vicinity of Enceladus
Sammanfattning : The Cassini spacecraft orbits Saturn since 2004, carrying a multitude of instruments for studies of the plasma environment around the planet as well as the constituents of the ring system. Of particular interest to the present thesis is the large E ring, which consists mainly of water ice grains, smaller than a few micrometres, referred to as dust. LÄS MER
13. Plasma and dust interaction in the magnetosphere of Saturn
Sammanfattning : The Cassini spacecraft orbits Saturn since 2004, carrying a multitude of instruments for studies of the plasma environment around the planet as well as the constituents of the ring system. Of particular interest to the present thesis is the large E ring, which consists mainly of water ice grains, smaller than a few micrometres, referred to as dust. LÄS MER
14. Input Estimation in Structural Dynamics
Sammanfattning : Knowledge of time-varying excitation is of importance in the design of a wide range of engineering applications, from spacecraft and processing plants to electronic circuits. Regardless of the actual application or underlying physics, the expected input will play a key role in the determination of adequate system properties and parameters. LÄS MER
15. Extending Microsystems to Very High Temperatures and Chemically Harsh Environments
Sammanfattning : Aiming at applications in space exploration as well as for monitoring natural hazards, this thesis focuses on understanding and overcoming the challenges of extending the applicability of microsystems to temperatures above 600°C as well as chemically harsh environments. Alumina and zirconia high-temperature co-fired ceramics (HTCC) with platinum as the conductor material, have in this thesis, been used to manufacture a wide range of high-temperature tolerant miniaturized sensors and actuators, including pressure and flow sensors, valves, a combustor, and liquid monopropellant microthrusters. LÄS MER