1,721,104 research outputs found
Decleva Caizzi (F.) - Funghi (M. S.) - Gigante (M.) - Lasserre (F.) - Santoni (Α.). Varia papyrologica
No full textCanevaile Robert. Decleva Caizzi (F.) - Funghi (M. S.) - Gigante (M.) - Lasserre (F.) - Santoni (Α.). Varia papyrologica. In: Revue belge de philologie et d'histoire, tome 71, fasc. 1, 1993. Antiquité — Oudheid. pp. 161-162
Decleva Caizzi (F.) - Funghi (M. S.) - Gigante (M.) - Lasserre (F.) - Santoni (Α.). Varia papyrologica
No full textCanevaile Robert. Decleva Caizzi (F.) - Funghi (M. S.) - Gigante (M.) - Lasserre (F.) - Santoni (Α.). Varia papyrologica. In: Revue belge de philologie et d'histoire, tome 71, fasc. 1, 1993. Antiquité — Oudheid. pp. 161-162
Design and test of a maximum power point tracking system for Unisat-3 microsatellite
No full textThe limited available surface for solar arrays, which are often body mounted on microsatellites, imposes a critical constraint on the photovoltaic system. For this reason it is mandatory to extract the maximum possible power by the solar arrays on-board microsatellites.
A system capable to extract the maximum power from solar arrays in any operative condition, seems a very attractive way to design the power subsystem of a microsatellite. In this paper the analysis of a MPPT (maximum peak power tracking) system designed for UNISAT-3 microsatellite photovoltaic arrays is discussed. The microsatellite is entirely designed and developed from students researchers and professors of the Gruppo di Astrodinamica dell’Università degli Studi di Roma “La Sapienza” (G.A.U.S.S.). MPPT can also improve the system reliability, as shown by experiments performed using a damaged solar panel. A MPPT flying unit has been realized and it is currently being tested in orbit, on board UNISAT-3
Unisat-3 Attitude Determination
No full textUNISAT program was established at the Scuola di Ingegneria Aerospaziale of University of Rome “La Sapienza” in late nineties. In the framework of this project Professors, researcher and students of GAUSS (Gruppo di Astrodinamica dell’Università degli Studi “La Sapienza”), coordinated from Professor Filippo Graziani, have already designed, manufactured and launched in orbit three microsatellites.
UNISAT-3 was launched in July 2005 from Baykonour Cosmodrome. Telemetry data are regularly received from SPIV (San Pietro In Vincoli) ground station.
UNISAT-3 attitude is passively stabilized exploiting permanent magnets and magnetic hysteresis rods.
The paper deals with UNISAT-3 attitude determination, using real time telemetry data received when the satellite is in the ground station visibility.
Data collected during this portion of the orbit include three solar panel currents and voltage and three axes magnetoresistive magnetometer readings. The solar arrays are used as coarse sun sensor. Many disturbances such as Earth albedo and temperature affect the measurements whereas the magnetometer readings are affected by unknown biases due to the on-board magnetic stabilization system and residual magnetic dipole.
Practical considerations and mathematical techniques to smooth rough data taking into account perturbing effects, noise and bias affecting measurements are discussed. After data reduction the q-method has been exploited to evaluate attitude.
Achieved accuracy for attitude estimation has been evaluated on the order of 10 degrees
Omosessualità e omofobia oggi
No full textFondamenti concettuali. Gli omosessuali in Italia. Relazioni e stili di vita. L'atteggiamento sociale verso l'omosessualità. Stereotipi pregiudizi e discriminazioni. Salute mentale e omosessualità. I diritti degli omosessuali
Le dinamiche del pregiudizio e della discriminazione nei contesti scolastici
No full textSignificati e caratteristiche del bullismo. Specificità del bullismo omofobiche. Effetti psicosociali. Modelli teorici per la riduzione del bullismo omofobico
A space standards proposal for university-class Microsatellites
No full textHands-on education is recognized to be an invlauable tool to improve students skills, to stimulate their enthusiasm and to educate them to team work. University class satellites programs should be developed keeping in mind that education is the main goal and that university satellites are an unique opportunity to make involved students familiar with all the space mission phases. Moreover university budgets for education programs are much lower than industrial satellite. Therefore two main constraints must be fulfilled: a time schedule fitting with the student course duration and low economic budget. These have an impact on the standard which can be followed in university class satellites programs.
In this paper university-class satellite standardization is discussed on the basis of UNISAT program experience , reporting successful projects achievements and lessons learned through unsuccessful experiences. UNISAT program was established at Scuola di Ingegneria Aerospaziale by the Group of Astrodynamics of University of Rome “La Sapienza” (GAUSS) as an research and education program in which PhD and graduate students have the opportunity to gain hands-on experience on small space missions.
Four university satellites (UNISAT, UNISAT-2, UNISAT-3, UNISAT-4), weighting about 10 kg, have been designed, manufactured, tested and launched every two years since 2000 in the framework of this program
In the paper, after a brief overview of GAUSS new programs, an analysis of UNISAT satellites ground test campaign is carried out, identifying the most critical procedures and requirements to be fulfilled. Moreover a device for Low Earth Orbit low-cost satellite end-of-life disposal is presented, this system (SIRDARIA) pemits to fulfil with the international guidelines on space debris
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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