Author, as appears in the article.: Jna. Gavaldà; Judit Ollé; Diana Dubert; Ana Laverón-Simavilla; X. Ruiz; Valentina Shevtsova
Department: Química Física i Inorgànica
URV's Author/s: GAVALDÀ MARTÍNEZ, JOSEFA; Judit Ollé; Diana Dubert; Ana Laverón-Simavilla; RUIZ MARTÍ, JOSÉ JAVIER; Valentina Shevtsova
Abstract: The SODI-DCMIX thermodiffusion series experiments are part of the fluid research program carried out by the
European Space Agency on board of the International Space Station (ISS). In particular, DCIMIX2/3 were conducted
in the past inside the Microgravity Science Glovebox in the US Laboratory. Due to the physical nature of the processes
implied, these kind of runs were very long and particularly delicate because the low vibratory limit requirements must
be maintained for hours. This restrictive condition not always is achieved, therefore, an accurate surveillance of the
acceleration levels along the different experiments is necessary, to ensure a correct interpretation of the experimental
results. This work analyzes onsite vibrational environment of DCMIX2/3 covering the periods in which the experiments
were going on. To do so, acceleration signals only coming from the es03 sensor, nearest to the experimental
equipment and located in the Glovebox, were downloaded from the PIMS NASA website. To be as precise as possible
the signals have always been treated minute by minute. To detect the transient disturbances along the experiments,
several warnings were considered. First, one minute RMS values, for the three acceleration components were
evaluated, in time and in frequency domain. Additional information was obtained by plotting the power spectral
densities of the signals, PSD, and their spectrogram with the aim of characterizing long periods of acceleration data.
Due to great influence of low frequencies in this type of experiments, the Frequency Factor Index, FFI, was evaluated
each minute. Complementary, the spectral entropy evolution was proposed as a fast new indicator of external
perturbations. It has been found a good correlation between the spectrogram, temporal RMS and spectral entropy.
Finally, a graphic representation of the points associated to the one-minute RMS values in one-third-octave frequency
intervals which exceed the ISS limit curve requirements, was considered as a new and easy strategy for depicting the
warnings that recognize the main disturbances along the experiment
Research group: Processat Digital de Senyals en Entorns Aeroespacials i Biomèdics
Thematic Areas: Física Física Physics
licence for use: https://creativecommons.org/licenses/by/3.0/es/
ISSN: 0094-5765
Author identifier: 0000-0001-7881-4192; ; 0000-0002-7308-5872; ; 0000-0003-4020-4457;
Record's date: 2018-03-06
Last page: 419
Journal volume: 140
Papper version: info:eu-repo/semantics/acceptedVersion
Link to the original source: https://www.sciencedirect.com/science/article/pii/S0094576517306549?via%3Dihub
Funding program: plan; MVI-DCMIX/ISS; ESP2014-53603-P
Licence document URL: https://repositori.urv.cat/ca/proteccio-de-dades/
Article's DOI: 10.1016/j.actaastro.2017.09.007
Entity: Universitat Rovira i Virgili
Journal publication year: 2017
First page: 409
Publication Type: Article Artículo Article
Repositori URV