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The Gravity field and steady-state Ocean Circulation Explorer (GOCE) satellite, currently planned to be launched in the course of 2006, will require a precise drag compensation and a fine attitude control along the Local Orbiting Reference Frame (LORF) of a polar Sun-synchronous low orbit, allowing the Earth gravity field to be recovered with unprecedented accuracy by post-processing the scientific telemetry. To this aim, the spectral density of the spacecraft linear and angular accelerations must be limited below 0.025 µm / s²√Hz and 0.015 µrad / s²√Hz respectively, in the frequency range from 5 mHz to 0.1 Hz, the gradiometer measurement bandwidth. In the same range, the orientation errors of the spacecraft in the LORF and of the LORF in the inertial frame must be kept below 10 μrad / √Hz. The Drag-Free Mode, encharged of drag-free and attitude control (DFAC) during measurement phases, determines the spacecraft state vector using a very precise gradiometer, one large Field-of-View Star Tracker and a Satellite-to-Satellite Tracking Instrument. Force and torque commands are actuated by two assemblies of thrusters: a single ion-thruster acting along the orbital direction, a set of eight micro-thrusters acting along the other five degrees of freedom. To cover every mission scenario, other control modes have been studied and designed: the Coarse Pointing Mode dedicated to rate damping and Sun acquisition, the Fine Pointing Mode handling the transition to Drag-Free Mode and the Ultimate Safe Mode, a survival operative mode to improve mission reliability. Results presented in this paper give a positive perspective on the solidity of the current DFAC design. [ABSTRACT FROM AUTHOR]

Y2, ns, ***- Not significant, significant 0.1%, respectively, by the test F. received nitrogen fertilization, emphasizing that, in this case, the bacteria supplied nitrogen to plants in equivalence to nitrogen fertilizer. Considering that the maximum height of the Marandu grass plants observed corresponds to the treatment with nitrogen fertilization (100%), the other treatments presented height between 62 and 65% of the maximum production (13.9 cm) in the third cut, for C1 (P<0,001), when compared to nitrogen treatment (Table I). Marandu with the associative diazotrophic bacteria MTH2 and MTB1 provides part of the nitrogen necessary for the development of the grass, contributing positively to its production. A significant difference was observed in C1 (P<0.000) with higher root dry mass in plants that received nitrogen fertilization, followed by MTB1 treatment that produced the equivalent of (47.34%) of the maximum yield. [Extracted from the article]

The use of the integrated receiver in condensers for common automotive air conditioning – A/C – systems is widespread, because of its thermodynamic and operational advantages. Many studies have been already conducted on estimating the effect of the subcooling value. However, this study aims at determining the most important factors affecting the length of the refrigerant stable operating plateau and how the receiver filling is affected by geometrical and thermodynamic boundary conditions, by means of an experimental campaign built using design of experiments – DOE – techniques. Results demonstrate how the receiver diameter and the axial spacing between its inlet and outlet holes have the highest influence on the receiver operation. Finally, these results have been used to set up a numerical model able to accurately estimate the filling efficiency of the integrated receiver, in terms of volume of the operating plateau compared to the net available receiver volume. [ABSTRACT FROM AUTHOR]