cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
title: Testing in Aerospace Research: Introduction
Creators: name: Andrieux, Stephane
Publisher: name: ONERA
Year: 2016

description: The Onera's 70th anniversary is an opportunity to ask ourselves about the place
and evolution of research in the field of aerospace, especially in terms of needs and
means. A key topic of these reflections is obviously the contribution of testing activities.
Originally involved in all of the developments, they progressively had to face more
complex requirements, as well as the emergence of competing approaches, mainly based
on computation capacities and engineering methods. In this context, the 12th issue of
AerospaceLab Journal offers an overview of the evolution of testing in various scientific
domains concerned by aerospace developments: facilities, methods, instrumentation,
processing, performance, exploitation of data, new fields of research involved, etc. The
purpose is to assess the future use of testing, either as the best or as the only way to meet
a specific requirement, such as equipment certification for instance, or as a complementary
approach to other methods, including their validation or hardware in the loop analysis.
description: AerospaceLab Journal, Issue 12, December 2016; ISSN: 2107-6596
The cotriple resolution of differential graded algebras
Creators: name: Fresse, Benoit
Publisher: name: arXiv
Year: 2015
Subjects: subject: Algebraic Topology (math.AT)
subject: FOS: Mathematics
subject: 18D50 (Primary), 18G55, 18G30 (Secondary)

description: We consider the cotriple resolution of algebras over operads in differential graded modules. We focus, to be more precise, on the example of algebras over the differential graded Barratt-Eccles operad and on the example of commutative alegbras. We prove that the geometric realization of the cotriple resolution (in the sense of model categories) gives a cofibrant resolution functor on these categories of differential graded algebras.
description: 15 pages. Order of {\S}3 and {\S}4 switched. Minor amendments and a few remarks added. To appear in Proc. Amer. Math. Soc
THE IMPORTANCE OF PROFESSIONAL DEVELOPMENT FOR TEACHERS
Creators: name: Khadjaeva, Naima
Publisher: name: Zenodo
Year: 2024

description: Professional development is critical for the continuous growth and effectiveness of teachers in an ever-evolving educational landscape. This paper examines the significance of professional development for teachers, discussing the various forms it can take, the impact it has on teaching practices and student outcomes, and the barriers that educators often face in accessing professional development resources. By synthesizing existing research and providing recommendations for effective professional development practices, this study aims to underscore the essential role of continuous learning in promoting high-quality education.
Time Centrality in Dynamic Complex Networks
Creators: name: Costa, Eduardo Chinelate
name: Vieira, Alex Borges
name: Wehmuth, Klaus
name: Ziviani, Artur
name: da Silva, Ana Paula Couto
Publisher: name: arXiv
Year: 2015
Subjects: subject: Social and Information Networks (cs.SI)
subject: Physics and Society (physics.soc-ph)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: There is an ever-increasing interest in investigating dynamics in time-varying graphs (TVGs). Nevertheless, so far, the notion of centrality in TVG scenarios usually refers to metrics that assess the relative importance of nodes along the temporal evolution of the dynamic complex network. For some TVG scenarios, however, more important than identifying the central nodes under a given node centrality definition is identifying the key time instants for taking certain actions. In this paper, we thus introduce and investigate the notion of time centrality in TVGs. Analogously to node centrality, time centrality evaluates the relative importance of time instants in dynamic complex networks. In this context, we present two time centrality metrics related to diffusion processes. We evaluate the two defined metrics using both a real-world dataset representing an in-person contact dynamic network and a synthetically generated randomized TVG. We validate the concept of time centrality showing that diffusion starting at the best classified time instants (i.e. the most central ones), according to our metrics, can perform a faster and more efficient diffusion process.
A KPP road-field system with spatially periodic exchange terms
Creators: name: Giletti, Thomas
name: Monsaingeon, Léonard
name: Zhou, Maolin
Publisher: name: arXiv
Year: 2015
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: We take interest in a reaction-diffusion system which has been recently proposed [11] as a model for the effect of a road on propagation phenomena arising in epidemiology and ecology. This system consists in coupling a classical Fisher-KPP equation in a half-plane with a line with fast diffusion accounting for a straight road. The effect of the line on spreading properties of solutions (with compactly supported initial data) was investigated in a series of works starting from [11]. We recover these earlier results in a more general spatially periodic framework by exhibiting a threshold for road diffusion above which the propagation is driven by the road and the global speed is accelerated. We also discuss further applications of our approach, which will rely on the construction of a suitable generalized principal eigenvalue, and investigate in particular the spreading of solutions with exponentially decaying initial data.
description: Updated version, minor typos and details fixed
Ιός HPV : νεότερα δεδομένα
Creators: name: Μαλάμου, Βασιλική Κωνσταντίνου
Publisher: name: Aristotle University of Thessaloniki
Year: 2024
Subjects: HPV κύηση
HPV σε μη έγκυες γυναίκες
HPV άνδρες
HPV pregnancy
HPV non pregnant women
HPV in men trial

description: Η παρούσα εργασία αποτελεί μια βιβλιογραφική ανασκόπηση σχετικά με τις νέες γνώσεις γύρω από τον HPV. Αρχικά, δίδονται κάποιες εισαγωγικές πληροφορίες για τον HPV: η δομή του, ο διαχωρισμός του σε υπότυπους υψηλού και χαμηλού κινδύνου και οι τρόποι μετάδοσής του (σεξουαλική επαφή, περιγεννητική μετάδοση, μετάδοση χωρίς επαφή). Στη συνέχεια, περιγράφονται οι κλινικές ενδείξεις της μόλυνσης από HPV: τα γεννητικά κονδυλώματα και η υποτροπιάζουσα θηλωμάτωση του αναπνευστικού. Ακολούθως, αναφέρονται οι τύποι καρκίνου που έχουν συνδεθεί με τον HPV, με έμφαση στον καρκίνο του τραχήλου της μήτρας. Στο ειδικό μέρος αναλύεται η μεθοδολογία που ακολουθήθηκε για την εύρεση των δεδομένων της βιβλιογραφικής ανασκόπησης. Πιο συγκεκριμένα χρησιμοποιήθηκαν αξιόπιστες βάσεις δεδομένων όπως η pubmed, ότι έγιναν τρεις αναζητήσεις, καθώς απαιτήθηκε εύρεση δεδομένων για τρεις ομάδες πληθυσμού (άνδρες, γυναίκες, έγκυες γυναίκες) και χρησιμοποιήθηκαν φίλτρα για να παρουσιαστούν αποτελέσματα μόνο για τα τελευταία 5 χρόνια. Έπειτα γίνεται παρουσίαση και ερμηνεία των αποτελεσμάτων της αναζήτησης και των συμπερασμάτων που εξάχθηκαν από αυτήν.
description: Τhis thesis is a review of the newest studies concerning HPV. Initially, a brief overview of HPV is given: its structure, its stratification to low and high risk and its modes of transmission (sexual, vertical and without contact). Furthermore, the clinical clinical indications of an HPV infection are described: genital warts and Recurrent Respiratory Papillomatosis. Also, there is a brief presentation of the types of cancer associated with HPV, with emphasis on cervical cancer. Focusing on the literature review, the search strategy for the literature is discussed. Specifically, the use of verified search engines like pubmed, how three separate searches were performed, one for each of the specified groups, pregnant women, women and men) and the use of filters in order to display results from the last 5 years. The results are presented as well as the conclusions derived from them.
description: Το Τμήμα Ιατρικής της Σχολής Επιστημών Υγείας, του Αριστοτελείου Πανεπιστημίου Θεσσαλονίκης (ΑΠΘ) σε συνεργασία με το Τμήμα Ιατρικής της Σχολής Επιστημών Υγείας του Δημοκρίτειου Πανεπιστημίου Θράκης (ΔΠΘ), το Τμήμα Πολιτικών Μηχανικών ΤΕ της Σχολής Τεχνολογικών Εφαρμογών του Αλεξάνδρειου ΤΕΙ Θεσσαλονίκης (ΑΤΕΙΘ) και το Τμήμα Γεωλογίας της Σχολής Θετικών Επιστημών του Αριστοτελείου Πανεπιστημίου Θεσσαλονίκης (ΑΠΘ) οργανώνουν και λειτουργούν από το χειμερινό εξάμηνο του ακαδημαϊκού έτους 2018-2019 Διϊδρυματικό Πρόγραμμα Μεταπτυχιακών Σπουδών (ΔΠΜΣ) με τίτλο «ΥΓΕΙΑ ΚΑΙ ΠΕΡΙΒΑΛΛΟΝΤΙΚΟΙ ΠΑΡΑΓΟΝΤΕΣ» («Health and Environmental Factors»). Τη διοικητική υποστήριξη του Προγράμματος αναλαμβάνει το Τμήμα Ιατρικής της Σχολής Επιστημών Υγείας ΑΠΘ (επισπεύδον Τμήμα).
title: Inverse Problems and Experiments: a Fruitful Symbiosis
Creators: name: Andrieux, Stephane
Publisher: name: ONERA
Year: 2016

description: This paper offers a partial overview of some techniques and results emanating
from inverse problems or signal processing with application to the development
or enhancement of the exploitation of data obtained by experiments on physical
systems pertaining to the aerospace domain. The first part deals with linear problems
encountered in various problems of signal processing, whereas the second one
addresses two specific image-based identification techniques. Finally, the conclusion
strives to identify some future trends.
description: AerospaceLab Journal, Issue 12, December 2016; ISSN: 2107-6596
Measurements of non-photonic electrons with the STAR experiment
Creators: name: Rusňáková, Olga
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: Non-photonic electrons (NPE), produced by semileptonic decays of D and B mesons, are good probes to study the properties of hot and dense medium created in relativistic heavy ion collisions at RHIC. Studies of heavy quark production in p+p collisions can test the validity of perturbative QCD. They also provide a baseline to study the effects of nuclear matter on the production of heavy quarks in heavy ion collisions. In this paper, we present recent results of NPE spectra measured in p+p collisions at $\sqrt{s}=200$ GeV in mid-rapidity. We also report NPE nuclear modification factor $R_{AA}$ and elliptic flow $v_2$ in Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV.
description: Proceedings of Hot Quarks 2014 conference
title: On Recent Advances in Microstructural Characterization and In-Situ Testing Techniques to Study Material Behavior
Creators: name: Busso, Esteban
name: Boivin, Denis
name: Leveque, David
Publisher: name: ONERA
Year: 2016
Subjects: IN-SITU SEM TESTING
DIGITAL IMAGE CORRELATION
FULL- FIELD MEASUREMENTS
MICROSTRUCTURAL DESCRIPTION

description: The deformation fields within grains in polycrystalline materials are generally highly
heterogeneous and can be the precursors to the nucleation of micro-cracks or
cavities. Such behavior is conditioned by microstructural features, such as grain
structure, texture, morphology, and size. The understanding of the inter-relationship
between the materials microstructural characteristics and complex deformation and
damage phenomena is crucial to the formulation of structural integrity assessments
of engineering components, since they constitute the physical bases of the required
constitutive models of deformation and failure.
In this work, an overview is provided of recent experimental techniques developed at
ONERA and elsewhere to characterize the microstructure and to measure the deformation
of metallic materials. Some of the most promising characterization, measurement and
identification techniques and methods used to develop, calibrate and validate physicsinspired
constitutive models will be discussed, and illustrative examples will be given.
It will be shown that the individual use of traditional interferometric, characterization and
testing techniques is being replaced by the combined use of state-of-the-art techniques
based on image correlation (2D and 3D), in-situ and ex-situ scanning electronic
microscopy (SEM), EBSD, amongst others. Discussions about future trends, including
the great potential offered by the combination of in-situ techniques at various scales with
real time computations, are presented.
description: AerospaceLab Journal, Issue 12, December 2016; ISSN: 2107-6596
title: Combined Experimental and Modeling Approaches for Strength Analysis of 3D Woven Composites: From Elementary Coupons to Complex Aeronautical Structures
Creators: name: Hurmane, Antoine
name: Mavel, Anne
name: Paulmier, Pascal
name: Laurin, Frederic
Publisher: name: ONERA
Year: 2016
Subjects: DAMAGE
FAILURE
3D WOVEN COMPOSITE
COMPOSITE COMPONENT

description: New generations of 3D woven composite materials have been recently developed
to be used in aeronautics as an alternative to the classical laminated composite
materials, for structures exposed to impact. Therefore, it has been necessary to
determine precisely the damage and failure scenarios for such materials subjected to
different kinds of loadings through a large experimental testing campaign performed at
Onera on unnotched coupons. These tests have been multi-instrumented to understand
the different damage and failure mechanisms encountered in 3D woven composite
materials. Based on these observations, a model, named Onera Damage Model for
Polymer Matrix Composites (ODM-PMC), has been developed specifically for such
materials. This non-linear material approach takes into account the different observed
sources of non-linearity (viscoelasticity of the matrix, inplane matrix damage, interyarn
debondings and fiber yarn failures) and has been validated through comparisons
with available tests on unnotched specimens. Moreover, the predicted failure loads,
obtained with the ODM-PMC model, on plates containing different kinds of geometrical
singularities, such as a hole or a milled groove, have been compared successfully to
multi-instrumented test results also performed at Onera . Finally, the ODM-PMC model
has been applied to large 3D woven composite structures, quite representative of real
industrial components. The predicted damage and failure scenarios seem to be relevant
as compared to data available in the literature. Moreover, the obtained computational
times are compatible with usage in an industrial environment. Therefore, it has been
demonstrated that this approach, implemented in a commercial finite element code,
could be used in design offices in aeronautical industries.
description: AerospaceLab Journal, Issue 12, December 2016; ISSN: 2107-6596
Some problems with reproducing the Standard Model fields and interactions in five-dimensional warped brane world models
Creators: name: Smolyakov, Mikhail N.
name: Volobuev, Igor P.
Publisher: name: arXiv
Year: 2015
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In the present paper we examine, from the purely theoretical point of view and in a model-independent way, the case, when matter, gauge and Higgs fields are allowed to propagate in the bulk of five-dimensional brane world models with compact extra dimension, and the Standard Model fields and their interactions are supposed to be reproduced by the corresponding zero Kaluza-Klein modes. An unexpected result is that in order to avoid possible pathological behavior in the fermion sector, it is necessary to impose constraints on the fermion field Lagrangian. In the case when the fermion zero modes are supposed to be localized at one of the branes, these constraints imply an additional relation between the vacuum profile of the Higgs field and the form of the background metric. Moreover, this relation between the vacuum profile of the Higgs field and the form of the background metric results in the exact reproduction of the gauge boson and fermion sectors of the Standard Model by the corresponding zero mode four-dimensional effective theory in all the physically relevant cases, allowed by the absence of pathologies. Meanwhile, deviations from these conditions can lead either back to pathological behavior in the fermion sector or to a variance between the resulting zero mode four-dimensional effective theory and the Standard Model, which, depending on the model at hand, may, in principle, result in constraints putting the theory out of the reach of the present day experiments.
description: 18 pages, LaTeX. v3: signs corrected in eqs. (37), (38), (49) and in footnote 2; reference added; minor revision of the text
title: Complex Thermo-Mechanical Approaches to Study the Behavior of High-Temperature Alloys
Creators: name: Bonnand, Vincent
name: Pacou, Didier
Publisher: name: ONERA
Year: 2016
Subjects: NON-ISOTHERMAL
HIGH TEMPERATURE
THERMO-MECHANICAL FATIGUE
THERMAL GRADIENT MECHANICAL FATIGUE
SINGLE CRYSTAL SUPERALLOY
COOLED TURBINE BLADE
OVERHEATING

description: The work discusses the complex thermo-mechanical approaches developed at
ONERA within the context of gas turbine component fatigue tests. Emphasis is
placed on the general experimental methods to test nickel-based single crystal superalloys
used in gas turbine blades under severe thermal and mechanical conditions. First,
the successive steps required in combined thermal and mechanical fatigue testing
are briefly discussed. Particular focus is placed on the techniques developed to reliably
control and measure temperature fields generated by induction heating. The main
experimental techniques used for thermo-mechanical testing are then discussed.
Here, an axial-torsional thermo-mechanical fatigue (TMF) testing rig used to study the
coupling effects of combined thermal and mechanical loads is described. How a thermal
gradient is introduced in the TMF specimens to reproduce the internal air cooling
technology of modern gas turbine blades is shown. In order to increase the representativeness
of in-service conditions, the problem of thermo-mechanical fatigue coupled
with thermal gradients is investigated using smooth, multi-perforated, and thermal
barrier coated samples. It is shown that such testing capabilities can reproduce realistic
thermomechanical loading conditions typical of service and constitute a powerful
means to develop and validate fatigue life prediction methods. Furthermore, the effect
of an overheating event that can occur during a one-engine-inoperative event during
in-service operation is also investigated. This type of engine malfunction is known to
lead to a degradation of the microstructure, which can modify the material constitutive
behavior and affect the remaining lifetime. Finally, the additional complexities associated
with the creep-fatigue interaction, the required constitutive models and the computational
challenges are discussed.
description: AerospaceLab Journal, Issue 12, December 2016; ISSN: 2107-6596
Modelling of the dynamical and ozone interactions in the polar stratosphere with ICON-ART
Creators: name: Wang, Shaoyin
Publisher: name: Karlsruher Institut für Technologie (KIT)
Year: 2019
Subjects: ICON-ART
stratospheric ozone
QBO
modelling
atmospheric waves
planetary waves
stratosphere

description: Models with a well-represented stratosphere have been shown to increase the predictability on weather and climate scales through stratosphere-troposphere coupling. However, stratospheric phenomena, such as the Quasi-biennial Oscillation (QBO) or stratospheric ozone, are still poorly represented in current atmospheric models. This study characterizes and improves stratospheric simulations with the next generation weather/climate model ICON-ART, and gives insights into the dynamical and chemical (stratospheric ozone) interactions in the polar stratosphere. The climatology of a low resolution version of ICON-ART is examined and validated against ERA-Interim data. The sub-grid scale orographic (SSO) gravity wave drag is found unconstrained in the upper stratosphere, leading to warm biases in the Northern Hemisphere (NH) winter polar stratosphere. After reducing the SSO gravity wave drag, the modelled NH polar stratosphere has a more realistic mean state. At a low resolution, the model also fails to simulate the QBO-like oscillation that is observed in the equatorial zonal wind and is dominated by easterlies. In order to explore dynamical interactions between the stratospheric zonal winds in the tropics and the polar stratosphere, a QBO-like oscillation is imposed in ICON by relaxation using ERA-Interim winds (QBO-relaxation). Then, the Holton-Tan relationship, a phenomenon in which equatorial zonal winds synchronize with the NH winter polar stratosphere, is generally reproduced in the QBO-relaxation simulations. Based on idealized experiments, I found that the polar stratosphere is sensitive to the QBO phases and to relaxation height ranges. When the modelled equatorial zonal wind in the upper stratosphere is relaxed towards ERA-Interim, it results in (1) a colder NH polar stratosphere, for which the modulation of planetary wave meridional propagation is responsible, and (2) a Holton-Tan relationship where the timing depends on the relaxation depth. Furthermore, two stratospheric ozone representations in ICON-ART are compared: (1) interactive-ozone considers ozone-meteorology coupling and (2) non-interactive-ozone uses the climatological ozone of the interactive-ozone simulation. Climatological ozone is a default in many climate models. When ozone is calculated interactively, the model simulated a colder polar stratosphere with a delayed polar vortex breakup in the Southern Hemisphere. Depending on the background zonal wind, planetary waves are found to feedback onto the changes in the polar stratospheric temperature either negatively or positively.
title: Aircraft Ground Vibration Testing at ONERA
Creators: name: Giclais, Stephane
name: Lubrina, Pascal
name: Stephan, Cyrille
Publisher: name: ONERA
Year: 2016
Subjects: GROUND VIBRATION TEST
MODAL IDENTIFICATION
STRUCTURAL DYNAMICS
FLUTTER

description: During the development of a new aircraft, the Ground Vibration Test (GVT) is an
important milestone because flutter computation relies on its results to determine
the start of flight tests. Since the creation of ONERA after World War II, the GVT
has always been the subject of fundamental research and application on industrial
structures. On the occasion of the 70th anniversary of ONERA, an historical survey
of the main methods and significant tests is proposed in this paper. After a brief
introduction to the goals of a GVT, we highlight the continuous improvements made in
this discipline in parallel with the progress in electronics, computers and algorithms,
mainly focusing on internal studies at ONERA. Even though nowadays the GVT has
reached maturity, aircraft dynamics is so challenging that several paths of research
activities still remain. Keeping in mind the high quality standards expected by aircraft
manufacturers, a vision of promising aspects for the future of GVT is finally proposed.
description: AerospaceLab Journal, Issue 12, December 2016; ISSN: 2107-6596
Diffractive Bremsstrahlung in Hadronic Collisions
Creators: name: Pasechnik, Roman
name: Kopeliovich, Boris
name: Potashnikova, Irina
Publisher: name: arXiv
Year: 2015
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Production of heavy photons (Drell-Yan), gauge bosons, Higgs bosons, heavy flavors, which is treated within the QCD parton model as a result of hard parton-parton collision, can be considered as a bremsstrahlung process in the target rest frame. In this review, we discuss the basic features of the diffractive channels of these processes in the framework of color dipole approach. The main observation is a dramatic breakdown of diffractive QCD factorisation due to the interplay between soft and hard interactions, which dominates these processes. This observation is crucial for phenomenological studies of diffractive reactions in high-energy hadronic collisions.
description: 29 pages, 16 figures; typos corrected; references added; minor corrections
title: Testing in Aerodynamics Research at onera: the Example of the Transonic Buffet
Creators: name: Jacquin, Laurent
name: Brion, Vincent
name: Molton, Pascal
name: Sipp, Denis
name: Dandois, Julien
name: Deck, Sebastien
name: Sartor, Fulvio
name: Coustois, Eric
Publisher: name: ONERA
Year: 2016
Subjects: AERODYNAMICS
TRANSONIC FLOWS
FLOW DIAGNOSTICS
CFD
GLOBAL INSTABILITY
TURBULENCE

description: The paper reviews research conducted at ONERA over the last thirty years on the
transonic buffet. We first present the transonic buffet phenomenon and we explain
its importance for aeronautical applications. Then, a distinction is made between the
2D buffet produced by an airfoil and the 3D buffet that characterizes swept wings of
finite span. The 2D buffet amounts to a pure oscillation of the shock phase-locked with
the detachment and reattachment of the boundary layer downstream, whereas the
3D buffet takes the form of a pocket of broadband perturbations located in a limited
portion of the wing. We recall that these mechanisms were first studied in the 1980s
through a series of tests conducted in the transonic wind tunnel ONERA T2 at Toulouse
and in the large transonic wind tunnel ONERA S2Ma at Modane. Since this pioneering
work, progress in the measurement techniques has led to the constitution of a comprehensive
database of the 2D buffet that we describe. This database, obtained in the wind
tunnel ONERA S3Ch at Meudon, has been extensively used to validate various CFD
tools, with the latter being used in turn to investigate the buffet physics. We illustrate
this collaboration between simulation and physics by recalling that a linear stability
analysis of accurate Reynolds-Averaged-Navier-Stokes (RANS) solutions made it possible
to prove that the buffet on a 2D airfoil stems from a global instability mechanism.
We also review more recent tests done in the case of a laminar airfoil, which reveal
very distinct behaviors of the buffet flow. This illustrates how sensitive the buffet is to
the nature of the boundary layer. The last section of the paper gives a short overview of
advanced simulations for these different test cases. In the conclusion, we list research
perspectives, which include some more general topics such as data assimilation.
description: AerospaceLab Journal, Issue 12, December 2016; ISSN: 2107-6596
MPEC 2024-R254 : 2024 RL12
Creators: name: Minor Planet Center Staff
Publisher: name: The Minor Planet Center
Year: 2024
Subjects: subject: Small Solar System bodies
valueUri: http://astrothesaurus.org/uat/1469
subject: 2024 RL12

description: The Minor Planet Electronic Circulars contain information on unusual minor planets, routine data on comets and natural satellites, and occasional editorial announcements.  They are published on behalf of Division F of the International Astronomical Union by the Minor Planet Center, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
Nonequilibrium Kinetic Modeling of Sintering of a Layer of Dispersed Nanocrystals
Creators: name: Gorshkov, Vyacheslav
name: Kuzmenko, Vasily
name: Privman, Vladimir
Publisher: name: arXiv
Year: 2014
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We report a kinetic Monte Carlo modeling study of nanocrystal layer sintering. Features that are of interest for the dynamics of the layer as a whole, especially the morphology of the evolving structure, are considered. It is found that the kinetics of sintering is not entirely a local process, with the layer morphology affected by the kinetics in a larger than few-particle neighborhood. Consideration of a single layer of particles makes the numerics manageable and allows visualization of the results, as well as numerical simulations of several realizations for statistical averaging of properties of interest. We identify optimal regimes for sintering, considering several particle size distributions and temperature control protocols.
title: Planar Particle Image Velocimetry for Aerospace Research at ONERA
Creators: name: Leclaire, Benjamin
name: Brossard, Christophe
name: Courtier, Romain
name: David, Frederic
name: Davoust, Samuel
name: Gilliot, Anne
name: Jacquin, Laurent
name: Jourdan, Jean-Marc
name: Leon, Oliver
name: Masseboeuf, Sylvain
name: Mouton, Sylvain
name: Monnier, Jean-Claude
name: Piot, Estelle
name: Ristori, Arnaud
name: Sebbane, Delphine
name: Simon, Frank
Publisher: name: ONERA
Year: 2016
Subjects: PIV
STEREO PIV
TIME-RESOLVED PIV
WIND-TUNNEL
EXPERIMENTATION
AEROSPACE RESEARCH

description: Planar Particle Image Velocimetry (PIV) is a measurement technique that yields the
instantaneous spatial structure in a planar cut of a flow. It exists in several forms
(two-component, three-component or Stereo, and time-resolved), all of which are now
considered to be mature, and as production tools for flow investigation in experimental
facilities. This contribution is aimed at showing, through various examples of research
activities, how it is currently being used at ONERA, with the idea of extending knowledge
on complex flows, and therefore on the performance of complex systems. After
a short reminder of the operating principle of planar PIV, applications are presented in
the contexts of jet mixing physics, helicopter fuselage drag reduction, reacting flows,
industrial wind-tunnels, and acoustics.
description: AerospaceLab Journal, Issue 12, December 2016; ISSN: 2107-6596
title: Doppler LIDAR Developments for Aeronautics
Creators: name: Besson, Claudine
name: Dolfi-Bouteyre, Agnes
name: Canat, Guillaume
name: Cezard, Nicolas
name: Augere, Beatrice
name: Durecu, Anne
name: Lombard, Laurent
name: Valla, Matthieu
name: Hallermeyer, Alexandre
Publisher: name: ONERA
Year: 2016
Subjects: LIDAR
DOPPLER LIDAR
COHERENT DETECTION
DIRECT DETECTION
FIBER LASER
STIMULATED BRILLOUIN SCATTERING
HIGH POWER FIBER AMPLIFIER
WAKE VORTEX
WIND MAPPING
EDDY DISSIPATION RATE
TURBULENCE SENSOR
GUST SENSOR
TRUE AIR SPEED
AIRBORNE SENSOR
FLIGHT SAFETY

description: Detecting atmospheric hazards such as wake vortices, turbulences, wind shear or
wind gusts would improve flight and airport traffic safety. Moreover, to face the
current and future challenges of air traffic growth in terms of environment, safety and
costs, one of the major challenges is to increase runway throughput by optimizing the
distance separation between aircraft. These are some of the issues, among others,
addressed by Doppler LIDARs. This powerful technique can provide remote air speed
data and is being deployed on the ground or in flight.
The paper presents some of the recent Doppler LIDAR developments at ONERA. Some
insight into state-of-the-art technology is provided, as well as perspectives for future
applications in aeronautics.
description: AerospaceLab Journal, Issue 12, December 2016; ISSN: 2107-6596
WESTWORLD: LA DISOLUCIÓN DE LA HYBRIS PROMETEICA EN LA CREACIÓN DEL ANDROIDE
Creators: name: Contreras Espuny, José María
Publisher: name: Tonos Digital
Year: 2020

description: El objetivo del siguiente trabajo es analizar la actualización del mito de Prometeo en la serie televisiva Westworld. Partiendo de un enfoque mitocrítico y comparativo de las ficciones tanto literarias como audiovisuales, pretendemos comprobar la materialización del mitema de la creación de vida artificial. Adoptaremos una perspectiva diacrónica (desde la Antigüedad hasta nuestros días) para comprobar cómo Westworld cristaliza una evolución del tema que, como se verá, ya estaba latente en el Frankenstein de Mary Shelley y con creciente protagonismo en la ciencia ficción de los siglos XX y XXI. Más concretamente, nos centraremos en la hybris, entendida como soberbia, y el consiguiente desafío a las leyes divinas. Veremos cómo ésta se debilita hasta desaparecer por completo en el caso de Westworld, al menos en su vertiente trascendental. Declinando definitivamente una balanza que oscilaba desde la aparición del moderno Prometeo, Westworld descarga de toda culpabilidad al hombre convertido en demiurgo y la transfiere al hombre en tanto que opresor. El pecado no corresponde a la soberbia técnica y científica, sino a la instrumentalización y desatención de la criatura, en este caso, del androide. Así pues, Westworld, en un mundo sin rastro de Dios, da por zanjada la discusión sobre la legitimidad de la creación de la vida para centrarse en la lucha dialéctica entre los hombres (opresores) y los androides (oprimidos).
title: Experimental Fluid Mechanics goes 3D: New Numerical Methods for Quantitative Instantaneous 3D Imagery of Fluids
Creators: name: Le Besnerais, Guy
name: Champagnat, Frederic
name: Cornic, Philippe
name: Plyer, Aurelien
name: Leclaire, Benjamin
name: Cheminet, Adam
name: Illoul, Cedric
name: Losfeld, Gilles
name: Le Sant, Yves
name: Donjat, David
name: Nicolas, Francois
name: Micheli, Francis
Publisher: name: ONERA
Year: 2016

description: We review recent developments made between three departments at ONERA
(DTIM, DAFE, DMAE) with regard to 3D imagery used in fluid mechanics
experiments. We first discuss 3D PIV (Particle Image Velocimetry) and present original
contributions on the modeling of the imaging process, the reconstruction of the
3D volume of particles and the estimation of the 3D motion field between two time
instants. These three contributions emphasize the pointwise character of particles in PIV,
in contrast with classical Tomo-PIV approaches, and have been shown to outperform
state-of-the-art methods, yielding more accurate 3D velocity estimations. Then, we
consider 3DBOS (Background Oriented Schlieren), which is aimed at estimating the
instantaneous 3D density field of a moving fluid. We have recently proposed an original
one-step numerical approach for 3DBOS. This method has been successfully used in
several experiments conducted in various ONERA facilities, in particular in the F2 and
S1MA wind tunnels. Finally, we draw some important perspectives, especially for the
study of compressible flows by combining both techniques.
description: AerospaceLab Journal, Issue 12, December 2016; ISSN: 2107-6596
title: Ro-Vibrational Spectroscopy in Hybrid fs/ps-CARS for N2 Thermometry
Creators: name: Nafa, Malik
name: Scherman, Michael
name: Bresson, Alexandre
name: Godard, Antoine
name: Attal-Tretout, Brigitte
name: Joubert, Pierre
Publisher: name: ONERA
Year: 2016
Subjects: COHERENT ANTI-STOKES RAMAN SCATTERING
THERMOMETRY
FEMTOSECOND LASERS
RAMAN SPECTROSCOPY
COMBUSTION DIAGNOSTICS

description: Ro-vibrational CARS spectroscopy is performed on the Q-branch of N2 in the
hybrid fs/ps regime. A new optical setup has been mounted using a single laser
source and a spectral filtering stage based on a volume Bragg grating and a Fabry-
Perot etalon, in order to achieve a good enough resolution. CARS spectra are recorded
in ambient air at a 1 kHz repetition rate. However, a CH4 /air flame is probed at 2 Hz,
in order to obtain a strong enough signal to enable thermometry. The theoretical
treatment is also detailed and provides the calculated spectrum, properly compared to
experimental profiles in order to retrieve the temperature. The accuracy of the hybrid
fs/ps-CARS thermometry is satisfactory as regards the state of the art, but further
experiments are in progress to increase the repetition rate of the measurement in hot
gases.
description: AerospaceLab Journal, Issue 12, December 2016; ISSN: 2107-6596
Chord-arc curves and the Beurling transform
Creators: name: Astala, K.
name: González, M. J.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Classical Analysis and ODEs (math.CA)
subject: Complex Variables (math.CV)
subject: FOS: Mathematics

description: We study the relation between the geometric properties of a quasicircle~$Γ$ and the complex dilatation~$μ$ of a quasiconformal mapping that maps the real line onto~$Γ$. Denoting by~$S$ the Beurling transform, we characterize Bishop-Jones quasicircles in terms of the boundedness of the operator~$(I-μS)$ on a particular weighted $L^2$~space, and chord-arc curves in terms of its invertibility. As an application we recover the~$L^2$ boundedness of the Cauchy integral on chord-arc curves.
description: 27 pages
title: Gravitation and Geodesy with Inertial Sensors, from Ground to Space
Creators: name: Touboul, Pierre
name: Metris, Selig
name: Le Traon, Olivier
name: Bresson, Alexandre
name: Zahzam, Nassim
name: Christophe, Bruno
name: Rodrigues, Manuel
Publisher: name: ONERA
Year: 2016
Subjects: GRAVITATION
EQUIVALENCE PRINCIPLE
SPACE GEODESY
EARTH GRAVITY FIELD
ACCELEROMETER
INERTIAL SENSOR

description: Since the years 2000, three space missions, CHAMP, GRACE, and GOCE, have led
us to consider the Earth\'s gravitational field and its measurement in a new light,
using dedicated sensors and adequate data processing, revealing the changes in the
Earth\'s field as the true signal rather than the disturbing terms in addition to the geostatic
reference field. Besides the possibilities offered by new technologies for the
development of inertial sensors, a space environment of course involves special constraints,
but also allows the possibility of a specific optimization of the concepts and
techniques well suited for microgravity conditions. We will analyze and compare with
others the interest in the electrostatic configuration of the instruments used in the main
payload of these missions, and we will consider the recent MICROSCOPE mission,
which takes advantage of the same mission configuration as a gradiometry mission
to test the universality of free fall whatever the mass composition. A few days after
launching the satellite in April 2016, we will show how we intend to validate the future
result, the existence or not of a violation signal of the equivalence principle, taking into
account the laboratory tests, where available, and the in-flight demonstrated performance
during the calibration phases and the scientific measurements. With regard to
ground measurements, either fixed or mobile, or under marine or aircraft conditions,
we will demonstrate the complementary interest of the atomic interferometer. Finally,
we will briefly discuss the future envisaged for these technologies, like that already
implemented in the Lisa-Pathfinder mission without a gold wire for the electrical control
of the charges of the mass, and these types of mission.
description: AerospaceLab Journal, Issue 12, December 2016; ISSN: 2107-6596
The strategic use of visuals on Facebook_Visual_Comm_Quarterly.pdf
Creators: name: Famulari, Umberto
Publisher: name: figshare
Year: 2020
Subjects: subject: 200102 Communication Technology and Digital Media Studies
subject: FOS: Media and communications

description: The article studies the images that the British political parties posted on Facebook during the 2019 UK elections. Verbal and non-verbal resources in the visuals were examined to look at the following strategies: Broadcasting policy, Mobilization, Attacking opponents and Image management. Overall, Attacking opponents was the most common strategy for verbal and non-verbal resources. Attacks against opponents were also associated with a higher number of likes and shares. A substantial portion of text in the images was used to talk about policies, in particular by the two largest parties, the Conservative Party and Labour Party. Visuals posted on Facebook by the Labour Party generated the highest number of audience reactions. Specific differences among political parties were also analyzed and discussed.
Analysis of constrained simulations of the Coma cluster and of its surrounding cosmic web
Creators: name: MALAVASI, Nicola
name: Sorce, Jenny G.
name: Dolag, Klaus
name: Aghanim, Nabila
Publisher: name: Zenodo
Year: 2023

description: The advent of wide-area spectroscopic galaxy surveys has allowed us to start investigating the properties of the filaments of the cosmic web. How filaments connect to clusters and how these connections impact cluster and galaxy evolution is a hot topic in astrophysics, of interest for ongoing experiments and future facilities (from both the gas phase perspective, e.g. eROSITA, and the galaxy distribution, e.g. Euclid). The average connectivity (number of connected filaments) of a few observed and simulated clusters has been measured and it has been found that it scales with cluster mass. We applied a cosmic web detection algorithm (DisPerSE) to the Sloan Digital Sky Survey (SDSS) to detect the filaments from the galaxy distribution. We then detected three secure filaments connecting to the Coma cluster. This discovery lead to the developing of a further investigation based on constrained numerical simulations, which allow us to reproduce in detail a portion of the nearby Universe, recreating observed clusters including Coma. We analyzed these simulations, with the aim of studying the evolution of the filaments around Coma throughout cosmic history and determining the impact of matter accretion channeled through these structures on the evolution of the Coma cluster. In this talk I will review our previous results and introduce the findings we obtained with the study of our constrained numerical simulations.
Chases and Escapes, and Optimization Problems
Creators: name: Ohira, Toru
Publisher: name: arXiv
Year: 2014
Subjects: subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: We propose a new approach for solving combinatorial optimization problem by utilizing the mechanism of chases and escapes, which has a long history in mathematics. In addition to the well-used steepest descent and neighboring search, we perform a chase and escape game on the "landscape" of the cost function. We have created a concrete algorithm for the Traveling Salesman Problem. Our preliminary test indicates a possibility that this new fusion of chases and escapes problem into combinatorial optimization search is fruitful.
description: 3 pages, 4 figures. To appear in the Proceedings of the International Symposium on Artificial Life and Robotics (AROB20th), Beppu, Oita Japan, January 21-23, 2015
title: Radiation Testing of Electronics Systems: How Can Simulation Tools Help in the Definition and Optimization of Test Plans in Labs?
Creators: name: Duzellier, Sophie
name: David, Jean-Pierre
name: Inguimbert, Christophe
name: Nuns, Thierry
name: Hubert, Guillaume
name: Artola, Laurent
Publisher: name: ONERA
Year: 2016
Subjects: RADIATIONS
SPACE ELECTRONICS
SPACE ENVIRONMENT
ELECTRONICS RELIABILITY
RADIATION ANOMALY

description: On-board space systems are exposed to harsh environmental conditions including
radiations, extreme temperatures and high-vacuum Each component of this
space environment, either separately or in synergy, induces short or long term
degradation of electronics or materials, thereby impacting reliability. The wide diversity
of observed disruptions, potential anomalies (and therefore of their underlying
physical-chemical mechanisms) and the large set of technologies involved require
the development of modeling tools to support experimentation, in order to achieve a
representative simulation of device response and a reliable prediction of the life, as well
as to limit ground testing.
description: AerospaceLab Journal, Issue 12, December 2016; ISSN: 2107-6596
title: Dealing with Complexity through Advanced Control Techniques
Creators: name: Bidaud, Philippe
name: Burlion, Laurent
name: De Plinval, Henry
name: Loquen, Thomas
name: Marzat, Julien
name:           Pralet Cedric
Publisher: name: ONERA
Year: 2016
Subjects: ROBUST CONTROL
CONSTRAINED SYSTEMS
PREDICTIVE CONTROL
HYBRID SYSTEMS
SENSOR-BASED CONTROL
MULTI-TASK CONTROL
DISTRIBUTED CONTROL
ADAPTIVE PLANNING

description: The control of complex dynamic systems, both in their behavior and in their mission,
goes through the implementation of multi-loop control architectures based on
information about the system internal state and from the environment, as well as on the
mission plan state. This results in systems that are becoming increasingly autonomous,
for which requirements in terms of safety and reliability, as well as expected performance,
are increasingly high. Research works developed at ONERA in the field of control for
autonomous systems cover all levels of the control architectures, which are basically
structured with respect to temporal aspects, as well as the level of abstraction that they
entail for the system dynamic. We will consider them in this paper by increasing level.
We will discuss the advances achieved recently in the robust control techniques of
uncertain dynamic systems generally implemented at the lower control level and we will
discuss their extensions to consider input and output constraints, as well as the hybrid
nature of most of the systems considered. To design \"task\" level control primitives that take
place just above the previous control loops, we will introduce sensor-based robust and
non-linear control techniques. These are based on information on the environment extracted
from exteroceptive sensors, to adapt system behavior to uncertainties and perturbations.
Multi-sensor and/or multi-objective controls will be discussed in this particular context.
We will also present several recent results in the field of trajectory tracking based on
visual navigation techniques in complex environments, which combine objectives and
constraints within the same control architecture. We will discuss how model predictive
control (MPC) techniques and advanced optimization techniques can be used for solving
the resulting control problems. In addition, we will discuss several ongoing developments
of these methods by exploiting distributed model predictive control techniques (DMPC) and
predictive control of hybrid systems. Finally, integration with the control architectures at the
upper level of reactive, predictive and distributed planning capabilities will be proposed to
accommodate time constraints and uncertainties in decision.
description: AerospaceLab Journal, Issue 12, December 2016; ISSN: 2107-6596
The Main Sequence of star forming galaxies across cosmic time
Creators: name: Paola, Popesso
Publisher: name: Zenodo
Year: 2023
Subjects: Main Sequence of star forming galaxies
galaxy evolution
galaxy environments

description: By compiling a comprehensive census of literature studies, we investigate the evolution of the main sequence (MS) of star-forming galaxies (SFGs) in the widest range of redshift (0 < z < 6) and stellar mass (10^8.5-10^11.5 M⊙) ever probed. We convert all observations to a common calibration and find a remarkable consensus on the variation of the MS shape and normalization across cosmic time. The relation exhibits a curvature towards the high stellar masses at all redshifts. The best functional form is governed by two parameters: the evolution of the normalization and the turnover mass (M0(t)), which both evolve as a power law of the Universe age. The turn-over mass determines the MS shape. It marginally evolves with time, making the MS slightly steeper towards z ~ 4-6. At stellar masses below M0(t), SFGs have a constant specific SFR (sSFR), while above M0(t) the sSFR is suppressed. We find that the MS is dominated by central galaxies. This allows us to turn M0(t) into the corresponding host halo mass. This evolves as the halo mass threshold between cold and hot accretion regimes, as predicted by the theory of accretion, where the central galaxy is fed or starved of cold gas supply, respectively. We, thus, argue that the progressive MS bending as a function of the Universe age is caused by the lower availability of cold gas in haloes entering the hot accretion phase, in addition to black hole feedback. We also find qualitatively the same trend in the largest sample of star-forming galaxies provided by the IllustrisTNG simulation. Nevertheless, we still note large quantitative discrepancies with respect to observations, in particular at the high-mass end. These can not be easily ascribed to biases or systematics in the observed SFRs and the derived MS.