1,721,006 research outputs found
ALTEA: anomalous long term effects on astronauts on board the international space station
Get PDFIn questo lavoro di tesi sarà riportato il lavoro portato avanti sull’esperimento ALTEA durante i miei anni di dottorato.
ALTEA (Anomalouos Long Term Effects on Astronauts) è un progetto finanziato dall’ASI, Agenzia Spaziale Italiana; è un programma multidisciplinare rivolto allo studio degli effetti funzionali della radiazione durante la permanenza umana nello spazio e contemporaneamente rivolto ad ottenere una misura della radiazione ambientale all’interno della Stazione Spaziale Internazionale (ISS). ALTEA è costituito da diversi esperimenti sia a terra che nello spazio.
Il mio coinvolgimento ha riguardato principalmente l’esperimento ALTEA-space di cui ho seguito personalmente i test hardware, le calibrazioni su fascio e l’analisi dei dati di volo.
Dopo una introduzione sull’ambiente spaziale e una breve descrizione dei principali effetti dell’esposizione a radiazione, riportate nel capitolo 1, nel capitolo 2 è presentato il programma ALTEA, con i suoi obiettivi scientifici e i differenti esperimenti che lo compongono. La facility ALTEA-space è descritta invece nel capitolo 3.
Nel 4 capitolo è riportata una semplice simulazione utilizzata per il calcolo del flusso di particelle atteso all’interno della ISS.
Nei capitoli successivi è per primo descritto tutto lo studio da me effettuato per verificare le performances e le caratteristiche del rivelatore ed in seguito vengono descritte le due sessioni di test eseguite all’acceleratore di particelle del GSI per testare e calibrare il modello di test (TM) e il modello di volo (FM) dell’apparato. Questo lavoro preliminare è stato completato con l’analisi dei dati acquisiti a terra dal modello di volo di ALTEA con tutti i sottosistemi accesi.
Dopo la consegna dell’hardware di ALTEA-space a NASA, ho contribuito alla configurazione ed installazione dell’ALTEA User Home Base (UHB) dove vengono ricevuti tutti i dati di volo e da dove sono effettuate le comunicazioni verso NASA a supporto delle operazioni di volo. Prima dell’inizio della missione ho partecipato alle simulazioni NASA volte a familiarizzare con le operazioni di volo.
ALTEA è stata finalmente portata a bordo della Stazione Spaziale Internazionale all’interno della missione Shuttle STS-121 il 4 Luglio 2006; nell’ultimo capitolo di questa tesi è descritto lo stato attuale delle operazioni di volo e sono presentati i risultati dell’analisi condotta sui primi dati raccolti sulla ISS. In questa tesi sono stati analizzati circa tre mesi di dati e i primi risultati includono tra gli altri lo studio del flusso di particelle, I differenti flussi rivelati dai sei rivelatori di particelle e un primo calcolo delle abbondanze nucleari relative.
Ho infine contribuito a realizzare e a testare gli strumenti software di preprocessamento e di analisi dei dati usati sia per i dati di calibrazione che per i dati di volo. Questi strumenti sono stati sviluppati utilizzando diversi linguaggi di programmazione (C, VC++, VB, IDL).In this thesis I summarized the work carried out on ALTEA experiment during my PhD years.
ALTEA (Anomalouos Long Term Effects on Astronauts) is a project funded by ASI, the Italian Space Agency; it is a multidisciplinary program devoted to investigate the functional effects of radiation during man permanences in space and concurrently to get a measure of radiation environment inside the International Space Station. It is constitued by several experiments both gorund-based and in space.
I was mainly involved in the ALTEA-space experiment and I followed the hardware functioning tests, the calibration and the analysis of flight data.
After an overview of space environment and a brief description of the main effects of radiation exposure, reported in the first chapter, the Altea program is presented with its scientific goals and the different experiments that it includes. In particular the ALTEA-space facility is described in the third chapter.
In the fourth chapter a simple simulation to calculate the expected particle flux inside the ISS will be presented.
In the following chapters, first of all the study I performed to verify the detector performances and characteristics is described, then the two session tests carried out at the GSI accelerator in order to test and calibrate the Flight Model and the Test Model of the device. This preliminary work was completed with the analysis of the files acquired on ground with all ALTEA Flight Model subsystems active.
After ALTEA-space hardware was delivered to NASA, I contributed to asses the ALTEA User Home Base (UHB), where operation data are collected and the communications with NASA take place. Before the start of the mission operation I partecipated to the NASA simulations aimed at the reproduction of flight operations.
ALTEA was finally brought on board the International Space Station within the STS-121 Shuttle mission on the July the 4th 2006; in the last chapter of this thesis the actual flight operations are described and the results of analysis performed on the first scientific data gathered onboard ISS are showed. About three month data were analyzed in this thesis and the first results include, among others, the study of the particle rate, the different particle fluxes measured by the six particle detectors and the first calculation of relative nuclear abundances.
I contributed to realize and test pre-processing and analysis tools used both for calibration and for flight operations. These tools were developed using several programming languages (C, VC++, VB, IDL)
Simulation for the LET measurements performed by the ALTEA detector in the ISS-USLab: results, comparison with measurements and perspectives
No full textLandau-fit based real-time recognition of relativistic ions onboard ISS with ALTEA experiment
No full text
Performances of Kevlar and Polyethylene as radiation shielding on-board the International Space Station in high latitude radiation environment /639/166/984 /639/766/25 /128 article
Get PDFPassive radiation shielding is a mandatory element in the design of an integrated solution to mitigate the effects of radiation during long deep space voyages for human exploration. Understanding and exploiting the characteristics of materials suitable for radiation shielding in space flights is, therefore, of primary importance. We present here the results of the first space-test on Kevlar and Polyethylene radiation shielding capabilities including direct measurements of the background baseline (no shield). Measurements are performed on-board of the International Space Station (Columbus modulus) during the ALTEA-shield ESA sponsored program. For the first time the shielding capability of such materials has been tested in a radiation environment similar to the deep-space one, thanks to the feature of the ALTEA system, which allows to select only high latitude orbital tracts of the International Space Station. Polyethylene is widely used for radiation shielding in space and therefore it is an excellent benchmark material to be used in comparative investigations. In this work we show that Kevlar has radiation shielding performances comparable to the Polyethylene ones, reaching a dose rate reduction of 32 ± 2% and a dose equivalent rate reduction of 55 ± 4% (for a shield of 10 g/cm2)
The ALTEA experiment onboard the International Space Station
No full textThe knowledge of the composition of the radiation environment is an important information for all the radiation safety issues needed for the planning of future long manned space missions. The ALTEA detector is on board the International Space Station since July 2006 and during this period it has performed a detailed measurement of the radiation environment. In this paper we present a summary of past measures and results
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
- …
