Air gap influence on the vibro-acoustic response of Solar Arrays during launch

One of the primary elements on the space missions is the electrical power subsystem, for which the critical component is the solar array. The behaviour of these elements during the ascent phase of the launch is critical for avoiding damages on the solar panels, which are the primary source of energy for the satellite in its final configuration. The vibro-acoustic response to the sound pressure depends on the solar array size, mass, stiffness and gap thickness. The stowed configuration of the solar array consists of a multiple system composed of structural elements and the air layers between panels. The effect of the air between panels on the behaviour of the system affects the frequency response of the system not only modifying the natural frequencies of the wings but also as interaction path between the wings of the array. The usual methods to analyze the vibro-acoustic response of structures are the FE and BE methods for the low frequency range and the SEA formulation for the high frequency range. The main issue in the latter method is, on one hand, selecting the appropriate subsystems, and, on the other, identifying the parameters of the energetic system: the internal and coupling loss factors. From the experimental point of view, the subsystems parameters can be identified by exciting each subsystem and measuring the energy of all the subsystems composing the Solar Array. Although theoretically possible, in practice it is difficult to apply loads on the air gaps. To analyse this situation, two different approaches can be studied depending on whether the air gaps between the panels are included explicitly in the problem or not. For a particular case of a solar array of three wings in stowed configuration both modelling philosophies are compared. This stowed configuration of a three wing solar arrays in stowed configuration has been tested in an acoustic chamber. The measured data on the solar wings allows, in general, determining the loss factors of the configuration. The paper presents a test description and measurements on the structure, in terms of the acceleration power spectral density. Finally, the performance of each modelling technique has been evaluated by comparison between simulations with experimental results on a spacecraft solar array and the influence on the apparent properties of the system in terms of the SEA loss factors has been analyse

Tycho: Facilitation Support for Groupware User Tests

Running user tests for groupware requires tracking the progress of multiple users performing co-dependent tasks, while facilitating and observing their coordinated actions. This requirement negatively impacts the main objective of user testing, which is detecting usability flaws. User testing of groupware becomes more challenging when run remotely. Even if there are tools for remote user testing that can get the job done for a single user, they are not prepared for collaborative scenarios. In this paper we argue that tool support for the facilitation of user tests of groupware is missing. Consequently, we propose a method for user tests with tool assistance that makes it possible to automate task synchronization, especially for different workflows that must be run concurrently. We evaluated our proposal by comparing it to a manually facilitated approach during on-site coordinated user tests. The results indicate that, while the task of designing and running user tests with tool support takes more time, it allows the testers to better focus on detecting usability problems.Fil: Grigera, Julián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Informática. Laboratorio de Investigación y Formación en Informática Avanzada; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; ArgentinaFil: Gardey, Juan Cruz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Informática. Laboratorio de Investigación y Formación en Informática Avanzada; ArgentinaFil: Fernandez, Alejandro. Universidad Nacional de La Plata. Facultad de Informática. Laboratorio de Investigación y Formación en Informática Avanzada; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; ArgentinaFil: Garrido, Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Informática. Laboratorio de Investigación y Formación en Informática Avanzada; Argentin

Facial soft biometrics for recognition in the wild: recent works, annotation and COTS evaluation

The role of soft biometrics to enhance person recognition systems in unconstrained scenarios has not been extensively studied. Here, we explore the utility of the following modalities: gender, ethnicity, age, glasses, beard and moustache. We consider two assumptions: i) manual estimation of soft biometrics, and ii) automatic estimation from two Commercial Off-The-Shelf systems (COTS). All experiments are reported using the LFW database. First, we study the discrimination capabilities of soft biometrics standalone. Then, experiments are carried out fusing soft biometrics with two state-of-the-art face recognition systems based on deep learning. We observe that soft biometrics is a valuable complement to the face modality in unconstrained scenarios, with relative improvements up to 40%=15% in the verification performance when using manual/automatic soft biometrics estimation. Results are reproducible as we make public our manual annotations and COTS outputs of soft biometrics over LFW, as well as the face recognition scoresThis work was funded by Spanish Guardia Civil and project CogniMetrics (TEC2015-70627-R) from MINECO/FEDE

Knowledge pipeline in freight pipeline industry: competence- based model for open innovation

There is growing concern over the challenges for innovation in Freight Pipeline industry. Since the early works of Chesbrough a decade ago, we have learned a lot about the content, context and process of open innovation. However, much more research is needed in Freight Pipeline Industry. The reality is that few corporations have institutionalized open innovation practices in ways that have enabled substantial growth or industry leadership. Based on this, we pursue the following question: How does a firm’s integration into knowledge networks depend on its ability to manage knowledge? A competence-based model for freight pipeline organizations is analysed, this model should be understood by any organization in order to be successful in motivating professionals who carry out innovations and play a main role in collaborative knowledge creation processes. This paper aims to explain how can open innovation achieve its potential in most Freight Pipeline Industries

Harlequin Color Change in a Neonate Positive to Covid-19: Case Report

Background: Harlequin color change is a benign, idiopathic, self-limiting disorder characterized by an appearance of skin divided into two distinctly colored areas. Its etiology is unknown but thought to be caused by immaturity of hypothalamic regulation of peripheral vascular tone. COVID-19 infection in neonates is infrequent and rarely symptomatic, with only a few cases described in the literature. In isolation, both conditions have low incidence. This is the first case reported in the world literature of harlequin color change in a newborn who tested positive for COVID-19. There isn’t a single publication that links harlequin color change to COVID-19, yet. The Case: Newborn of a 34-year old mother. Who at 3 hours of life presented progressive respiratory distress with whimpering and cyanosis. At 20 hours presented a sudden color change in the right hemibody with unilateral hyperemia and contralateral pallor, simultaneous with a demarcated line separating the left and right sides of the body, involving the trunk, extremities and face, this remained for 10 minutes and then began to fade on its own until it disappeared completely. There were no changes in vital parameters associated with this phenomenon. Only one episode was reported. The transient character and the strict unilateral distribution of the manifestations did not confirm any etiology other than Harlequin phenomenon. Subsequently the patient evolved to respiratory deterioration, multiorgan failure (SOFA: 21), died at 22 days of life due to respiratory arrest. Conclusion: This is the first ever documented case in worldwide literature of harlequin color change in a neonate positive to COVID-19. Given the low incidence of both entities in isolation and the fact that they were discovered in the same patient, we suggest a strong possibility of SARS-CoV-2 to be the source of the harlequin phenomena in this case and should be considered as an indicator of severe COVID in newborns, but further studies that expand the selection of patients with this condition are needed. There is no literature linking the harlequin phenomenon with COVID-19

Power system of the Guanay II AUV

Guanay II is an autonomous underwater vehicle (AUV) designed to perform measurements in a water column. In this paper the aspects of the vehicle’s power system are presented with particular focus on the power elements and the state of charge of the batteries. The system performs both measurement and monitoring tasks and also controls the state of charge (SoC) of the batteries. It allows simultaneous charging of all batteries from outside the vehicle and has a wireless connection/disconnection mode. Guanay II uses a NiCd battery and for this reason the current integration as a SoC methodology has been selected. Moreover, it has been validated that it is possible to obtain instant consumption from the SoC circuit. Finally, laboratory and vehicle navigation tests have been performed to validate the correct operation of the systems and the reliability of the measured dataPostprint (published version

Sulfide-binding hemoglobins: Effects of mutations on active-site flexibility

The dynamics of Hemoglobin I (HbI) from the clam Lucina pectinata, from wild-type sperm whale (SW) myoglobin, and from the L29F/H64Q/V68F triple mutant of SW, both unligated and bound to hydrogen sulfide (H2S), have been studied in molecular dynamics simulations. Features that account for differences in H2S affinity among the three have been examined. Our results verify the existence of an unusual heme rocking motion in unligated HbI that can promote the entrance of large ligands such as H2S. The FQF-mutant partially reproduces the amplitude and relative orientation of the motion of HbI's heme group. Therefore, besides introducing favorable electrostatic interactions with H2S, the three mutations in the distal pocket change the dynamic properties of the heme group. The active-site residues Gln-64(E7), Phe-43(CD1), and His-93(F8) are also shown to be more flexible in unligated HbI than in FQF-mutant and SW. Further contributions to H2S affinity come from differences in hydrogen bonding between the heme propionate groups and nearby amino acid residues.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada

Sulfide-binding hemoglobins: Effects of mutations on active-site flexibility

The dynamics of Hemoglobin I (HbI) from the clam Lucina pectinata, from wild-type sperm whale (SW) myoglobin, and from the L29F/H64Q/V68F triple mutant of SW, both unligated and bound to hydrogen sulfide (H2S), have been studied in molecular dynamics simulations. Features that account for differences in H2S affinity among the three have been examined. Our results verify the existence of an unusual heme rocking motion in unligated HbI that can promote the entrance of large ligands such as H2S. The FQF-mutant partially reproduces the amplitude and relative orientation of the motion of HbI's heme group. Therefore, besides introducing favorable electrostatic interactions with H2S, the three mutations in the distal pocket change the dynamic properties of the heme group. The active-site residues Gln-64(E7), Phe-43(CD1), and His-93(F8) are also shown to be more flexible in unligated HbI than in FQF-mutant and SW. Further contributions to H2S affinity come from differences in hydrogen bonding between the heme propionate groups and nearby amino acid residues.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada