bluuebunny/crossref_metadata_2025_split huggingface dataset:
DETECTION OF VERY HARD γ-RAY SPECTRUM FROM THE TEV BLAZAR MRK 501
Authors: Shukla A. , Mannheim K. , Chitnis V. R. , Roy J. , Acharya B. S. , Dorner D. , Hughes G. , Biland A. 
Published: November 2016

ABSTRACT
The occasional hardening of the GeV-to-TeV spectrum observed from the blazar Mrk 501 has reopened the debate on the physical origin of radiation and particle acceleration processes in TeV blazars. We have used the ∼7 years of Fermi-LAT data to search for the time intervals with unusually hard spectra from the nearby TeV blazar Mrk 501. We detected hard spectral components above 10 GeV with photon index <1.5 at a significance level of more than 5 sigma on 17 occasions, each with 30 day integration time. The photon index of the hardest component reached a value of 0.89 ± 0.29. We interpret these hard spectra as signatures of intermittent injection of sharply peaked and localized particle distributions from the base of the jet.
INTERFERENCE AS AN ORIGIN OF THE PEAKED NOISE IN ACCRETING X-RAY BINARIES
Authors: Veledina Alexandra 
Published: November 2016

ABSTRACT
We propose a physical model for the peaked noise in the X-ray power density spectra of accreting X-ray binaries. We interpret its appearance as an interference of two Comptonization continua: one coming from the upscattering of seed photons from the cold thin disk and the other fed by the synchrotron emission of the hot flow. Variations of both X-ray components are caused by fluctuations in mass accretion rate, but there is a delay between them corresponding to the propagation timescale from the disk Comptonization radius to the region of synchrotron Comptonization. If the disk and synchrotron Comptonization are correlated, the humps in the power spectra are harmonically related and the dips between them appear at frequencies related as odd numbers 1:3:5. If they are anti-correlated, the humps are related as 1:3:5, but the dips are harmonically related. Similar structures are expected to be observed in accreting neutron star binaries and supermassive black holes. The delay can be easily recovered from the frequency of peaked noise and further used to constrain the combination of the viscosity parameter and disk height-to-radius ratio α(H/R)2 of the accretion flow. We model multi-peak power spectra of black hole X-ray binaries GX 339–4 and XTE J1748–288 to constrain these parameters.
PROTOSTELLAR OUTFLOWS IN L1340
Authors: Walawender Josh , Wolf-Chase Grace , Smutko Michael , OLinger-Luscusk JoAnn , Moriarty-Schieven Gerald 
Published: November 2016

ABSTRACT
We have searched the L1340 A, B, and C clouds for shocks from protostellar outflows using the H2 2.122 μm near-infrared line as a shock tracer. Substantial outflow activity has been found in each of the three regions of the cloud (L1340 A, L1340 B, and L1340 C). We find 42 distinct shock complexes (16 in L1340 A, 11 in L1340 B, and 15 in L1340 C). We were able to link 17 of those shock complexes into 12 distinct outflows and identify candidate source stars for each. We examine the properties (A
V, T
bol, and L
bol) of the source protostars and compare them to the properties of the general population of Class 0/I and flat spectral energy distribution protostars and find that there is an indication, albeit at low statistical significance, that the outflow-driving protostars are drawn from a population with lower A
V, higher L
bol, and lower T
bol than the general population of protostars.
TURNING AROUND ALONG THE COSMIC WEB
Authors: Lee Jounghun , Yepes Gustavo 
Published: November 2016

ABSTRACT
A bound violation designates a case in which the turnaround radius of a bound object exceeds the upper limit imposed by the spherical collapse model based on the standard ΛCDM paradigm. Given that the turnaround radius of a bound object is a stochastic quantity and that the spherical model overly simplifies the true gravitational collapse, which actually proceeds anisotropically along the cosmic web, the rarity of the occurrence of a bound violation may depend on the web environment. Assuming a Planck cosmology, we numerically construct the bound-zone peculiar velocity profiles along the cosmic web (filaments and sheets) around the isolated groups with virial mass

identified in the Small MultiDark Planck simulations and determine the radial distances at which their peculiar velocities equal the Hubble expansion speed as the turnaround radii of the groups. It is found that although the average turnaround radii of the isolated groups are well below the spherical bound limit on all mass scales, the bound violations are not forbidden for individual groups, and the cosmic web has an effect of reducing the rarity of the occurrence of a bound violation. Explaining that the spherical bound limit on the turnaround radius in fact represents the threshold distance up to which the intervention of the external gravitational field in the bound-zone peculiar velocity profiles around the nonisolated groups stays negligible, we discuss the possibility of using the threshold distance scale to constrain locally the equation of state of dark energy.
MAGNETICALLY DOMINATED PARALLEL INTERSTELLAR FILAMENTS IN THE INFRARED DARK CLOUD G14.225-0.506*
Authors: Santos Fábio P. , Busquet Gemma , Franco Gabriel A. P. , Girart Josep Miquel , Zhang Qizhou 
Published: November 2016

ABSTRACT
The infrared dark cloud G14.225-0.506 (IRDC G14.2) displays a remarkable complex of parallel dense molecular filaments projected on the plane of the sky. Previous studies of dust emission and molecular lines have speculated whether magnetic fields could have played an important role in the formation of such elongated structures, which are hosts to numerous young stellar sources. In this work we have conducted a vast polarimetric survey at optical and near-infrared wavelengths in order to study the morphology of magnetic field lines in IRDC G14.2 through the observation of background stars. The orientation of interstellar polarization, which traces magnetic field lines, is perpendicular to most of the filamentary features within the cloud. Additionally, the larger-scale molecular cloud as a whole exhibits an elongated shape also perpendicular to magnetic fields. Estimates of magnetic field strengths indicate values in the range 320–550 μG, which allow sub-alfvénic conditions, but do not prevent the gravitational collapse of hub–filament structures, which in general are close to the critical state. These characteristics suggest that magnetic fields played the main role in regulating the collapse from large to small scales, leading to the formation of series of parallel elongated structures. The morphology is also consistent with numerical simulations that show how gravitational instabilities develop when subjected to strong magnetic fields. Finally, the results corroborate the hypothesis that strong support from internal magnetic fields might explain why the cloud seems to be contracting on a timescale 2–3 times longer than what is expected from a free-fall collapse.
A HOT GASEOUS GALAXY HALO CANDIDATE WITH Mg X ABSORPTION
Authors: Qu Zhijie , Bregman Joel N. 
Published: November 2016

ABSTRACT
The hot gas in galaxy halos may account for a significant fraction of missing baryons in galaxies, and some of these gases can be traced by high ionization absorption systems in QSO UV spectra. Using high S/N Hubble Space Telescope/Cosmic Origins Spectrograph spectra, we discovered a high ionization state system at z = 1.1912 in the sightline toward LBQS 1435-0134, and two-component absorption lines are matched for Mg x, Ne viii, Ne vi, O vi, Ne v, O v, Ne iv, O iv, N iv, O iii, and H i. Mg x, detected for the first time (5.8σ), is a particularly direct tracer of hot galactic halos, as its peak ion fraction occurs near 106.1 K, about the temperature of a virialized hot galaxy halo of mass

. With Mg x and Ne viii, a photoionization model cannot reproduce the observed column densities with path lengths of galaxy halos. For collisional ionization models, one or two-temperature models do not produce acceptable fits, but a three-temperature model or a power-law model can produce the observed results. In the power-law model,

with temperatures in the range of

, the total hydrogen column density is

and the positive power-law index indicates most of the mass is at the high temperature end. We suggest that this absorption system is a hot volume-filled galaxy halo rather than interaction layers between the hot halo and cool clouds. The temperature dependence of the column density is likely due to the local mixture of multiple phase gases.
Comment représenter les relations de confiance interpersonnelles au sein des équipes ? L’exemple des pompiers en véhicule de secours et d’assistance aux victimes
Authors: Charron Camilo , Jouanne Élise , Morel Gaël , Chauvin Christine 
Published: November 2016

L’étude porte sur onze équipes de sapeurs-pompiers intervenant en véhicule de secours et d’assistance aux victimes (VSAV). L’objectif est méthodologique. Il s’agit de trouver une représentation graphique pour comparer les relations de confiance que les pompiers ressentent les uns envers les autres, au sein des différentes équipes. Trois dimensions de la confiance ont été évaluées par questionnaire : bienveillance, intégrité et compétence. Après avoir exposé les principaux écueils de l’analyse de telles données, deux indices ont été proposés, relatifs à la confiance totale et à la symétrie des relations. Les réponses ont pu être traitées ainsi par STATIS, une méthode d’analyse factorielle multiple peu connue en psychologie. Les résultats révèlent une structuration inattendue des relations de confiance, autour des fonctions exercées par chaque sapeur-pompier. La démarche exposée présente un intérêt pour tout psychologue souhaitant aisément accéder, au sein des équipes de travail, à la structure des relations de confiance interpersonnelle.
La relation entre timing de formation des répertoires du conflit et variation du degré de violence. Une analyse comparée du Liban et de la Belgique
Authors: Farhat Nadim 
Published: November 2016

La question du timing est traitée ici dans sa relation à la violence dans le contexte de deux histoires conflictuelles relativement longues, celles du Liban et de la Belgique. L’analyse s’appuie sur la notion de répertoire du conflit qui désigne l’ensemble des moyens historiquement expérimentés, accessibles au présent à un couple d’acteurs et au sein desquels ces derniers vont puiser la forme dominante de leur confrontation. En comparant sur plus d’un siècle l’évolution des moyens d’action privilégiés dans les deux cas étudiés, il apparaît que les mobilisations des acteurs communautaires libanais et belges contemporains épousent les contours de répertoires différents hérités du XIX e siècle. Les campagnes de revendication en Belgique opèrent à partir d’un répertoire de mouvements sociaux qui donne au conflit entre francophones et Flamands son caractère essentiellement non violent. Les combats armés au Liban se déclinent à partir d’un répertoire de guerres civiles et d’insurrections qui confère au conflit entre les communautés religieuses sa dimension souvent violente. Ce contraste est dû à une intersection, à un moment différent dans chaque cas, entre les premiers conflits et l’évolution du cadre étatique. Le timing d’apparition des premiers conflits, formant un répertoire spécifique d’action, déterminerait donc non pas la réapparition ultérieure d’un conflit, mais l’occurrence ou la non-occurrence de la violence en son sein ; en d’autres termes le caractère violent ou pacifique d’un conflit dépendrait de l’ordre dans lequel sont survenus historiquement le premier phénomène conflictuel et la réalité étatique moderne.
La diffusion transnationale de la catégorie de « Juste parmi les Nations ». (Re)penser l’articulation entre diffusion des droits de l’homme et globalisation de la mémoire
Authors: Gensburger Sarah 
Published: November 2016

Depuis le début des années 2000, la « mémoire » est devenue un outil des politiques de développement des Droits de l’homme, dans des pays en sortie conflit comme dans des démocraties anciennes, à l’échelle transnationale comme au sein de cadres nationaux. Cette évolution est régulièrement interprétée comme le signe d’une mémoire globalisée, cette « cosmopolitan memory » – portée d’abord et avant tout par le souvenir de l’Holocauste – et vecteur de diffusion des droits de l’homme. La globalisation de la mémoire des « Justes parmi les Nations » et de leur constitution en figures humanitaires exemplaires fournit l’occasion de questionner, empiriquement, ce lien apparent entre mémoire et droits de l’homme pour cerner, en amont comme en aval, ce qui est susceptible de se jouer d’autres que le «global» et «l’humanitaire» dans ces politiques dites de «la mémoire». Ce faisant, cet article croise approche néo-institutionnaliste et approche discursive des politiques publiques pour revisiter l’articulation entre dimensions stratégique, cognitive et institutionnelle au cœur des processus mémoriels.
S/N enhancement by means of array simulation for near surface seismic investigations
Authors: Tognarelli Andrea , Stucchi Eusebio 
Published: November 2016

ABSTRACTWe present a procedure for enhancing the signal‐to‐noise ratio (S/N) of shallow seismic reflection data based on two different steps: 1) an acquisition step that requires the recording of closely spaced common source records with standard source and receiver equipment and 2) a processing step where weighted or un‐weighted source and receiver arrays are simulated on the basis of required needs for source related noise attenuation and depth penetration. The data acquisition can be carried out employing single source‐single geophone recordings, with a standard 24 or 48‐channel equipment. Simple energy sources such as weight drop or sledgehammer are considered. The design and application of the spatial filters in the processing phase is very flexible and can be tailored to the specific needs. In fact, the simulated source and/or receiver arrays can be time and/or space variant and can be weighted to provide the desired responses. Optimal weights can be determined by means of Chebyshev polynomials. Real data examples show the increase in the data quality in terms of better coherent noise attenuation and of enhanced depth penetration.
The downward continuation of the tilt angle
Authors: Cooper Gordon 
Published: November 2016

ABSTRACTThe tilt angle filter can be used both to enhance images of aeromagnetic data and as the basis of semi‐automatic interpretation methods. For vertically magnetised and vertically dipping contacts, rescaling by factor is equivalent to computing from sources with all depths decreased by a factor . This downward continuation is much less sensitive to noise than Fourier transform‐based downward continuation techniques, and because it reduces interference, it allows more accurate source depth determination from methods such as the tilt‐depth method. The method can be applied irrespective of the source and magnetisation type if the tilt angle of the analytic signal amplitude is used.
Application of 2D elastic Rayleigh waveform inversion to ultrasonic laboratory and field data
Authors: Köhn D. , Meier T. , Fehr M. , De Nil D. , Auras M. 
Published: November 2016

ABSTRACTIn addition to geophysical applications from the near surface to a global scale, seismic full‐waveform inversion can be applied to ultrasonic data on the centimetre and decimetre scales for nondestructive testing of pavements, facades, plaster, sculptures, and load‐bearing structures such as pillars or core samples from boreholes, which can consist of geo‐materials and non‐geomaterials. Classical non‐destructive testing approaches are based on the inversion of body‐wave travel times to deduce P‐wave velocity models. In contrast, surface waves (especially Rayleigh waves) are well suited to quantify surficial alterations of material properties, e.g., due to weathering. Furthermore, ultrasonic measurements of test samples with known material parameters close the gap between synthetic tests or analytical solutions and field data applications to estimate the accuracy of seismic modelling and inversion codes. Due to the scale invariance of the problem, the full‐waveform‐inversion approaches developed on the ultrasonic scale are also applicable to larger scale geophysical problems. In this paper, we demonstrate the potential of two‐dimensional Rayleigh waveform inversion on the ultrasonic scale using two data examples acquired with a single‐fold, low‐coverage acquisition geometry. For a simple homogeneous Plexiglas block in a controlled laboratory environment, we discuss the accuracy of visco‐elastic Rayleigh wave modelling, as well as the sensitivity of two‐dimensional elastic full‐waveform inversion with respect to small data residuals. While the inversion is restricted to the recovery of the S‐wave velocity model, a passive visco‐elastic modelling approach with a homogeneous average ‐model is required in order to describe amplitude loss and dispersion of the Rayleigh wave. The applicability of this approach under field conditions is illustrated for an ultrasonic data example from the weathered sandstone facade of the Porta Nigra in Trier (Germany). In addition to a random medium resolution analysis of the full‐waveform‐inversion result, we particularly emphasise the importance of lateral model smoothing to mitigate small‐scale inversion artefacts and to avoid erroneous interpretations. The estimated two‐dimensional S‐wave velocity anomalies correlate well with prominent surficial weathering effects in the upper about 3 cm.
Physical Ice Management Operations - Field Trials and Numerical Modeling
Authors: Neville M. A. , Scibilia F. , Martin E. H. 
Published: November 2016

Abstract
Physical ice management is a critical element of station keeping operations in waters characterized by drifting sea ice: it minimizes ice related downtime. Ice management represents also an important cost driver for Arctic offshore developments. The ice management fleet needs to be assembled considering the particular site, season of interest and corresponding expected environmental conditions, the particular facility capabilities to operate in ice covered waters, and the desired operability of the entire system.
The paper describes the physical ice management trials performed during the Offshore Newfoundland Research Expedition in April 2015. These trials were planned and executed with the purpose to generate data to support the development of numerical models for simulating key aspects of the ice management operation.
The results of this paper are applicable to ice management fleet design. Particular focus is on Arctic and sub-Arctic areas characterized predominantly by open water, but still containing the risk of sea ice invasions, and vessels expected to operate in such areas.
Results from the field trials are presented and discussed. The paper elaborates on the schemes for numerical modeling of ice management, the challenges, and how field trial data can support the development of effective simulation tools.
Investigation and 3D Discrete Element Modeling of Fracture of Sea Ice Beams
Authors: Mohammadafzali S. , Sarracino R. , Taylor R. , Stanbridge C. W. , Marchenko A. 
Published: November 2016

Abstract
Flexural failure of sea ice is of interest in many different applications, ranging from understanding rubble formation processes to modeling bending failure of ice sheets against sloped structures and ship hulls. In this paper we present a brief summary of recent in-situ experiments carried out on side-loaded sea ice beam specimens on the ice fields near Storfjorden, Svalbard. Results from these tests have been used to parameterize a discrete element model of ice fracture under flexural loading. Simulations of these experiments in 3D have been carried out using a new material model within the open-source Discrete Element Method (DEM) code WooDEM which features cohesive bonds in tension, shear, flexure and torsion based on a contact model with normal, shear, torsional and flexural springs. A comparison of simulated and field test results, along with recommendations for future work is provided.
A Shipborne Measurement System to Acquire Sea Ice Thickness and Concentration at Engineering Scale
Authors: Lu Wenjun , Zhang Qin , Lubbad Raed , Løset Sveinung , Skjetne Roger 
Published: November 2016

Abstract
Sea ice concentration and thickness are important parameters for the calculations of ice actions and their effects on Arctic offshore structures and for the evaluation of icebreaker performance. Various methods exist nowadays to monitor these parameters, ranging from geophysical scale to local scale. During the Oden Arctic Technology Research Cruise 2015 (OATRC’ 15), we installed both Ice Concentration and Ice Thickness cameras and developed corresponding algorithms to achieve real time quantification of ice concentration and visual estimation of ice thickness information. For the ice concentration analysis, we utilized both the global Otsu method to categorize an image into two regions (black water and white ice); and the K-means method to identify more regions based on the gray scale from the image. With the methods, we conducted a case study by analyzing the ice concentration in a selected time window. In the case study, we include both dry ice (in white color) and wet ice (in gray color, generally composed of ice rubbles, young ice, and melt ponds) as ice region for the K-means method. The K-means method yields higher ice concentration values in comparison to the global Otsu method, in which, melt ponds/young ice was frequently mistaken as open water. It turns out that the K-means method enables more flexibility to cope with the complicated ice environment by separating the image into more regions that can be included as ice in an ice concentration analysis. For the ice thickness camera, the intention was to capture the events while a broken ice piece is tilted, next to the ship side, and expose its thickness region to the camera. In this paper, we developed an automatic tracking algorithm to sift these events out from all the images taken by the Ice Thickness acquisition system. After projecting a grid with physical length onto the image, the ice thickness information can be visually quantified. We compared the ice thickness obtained from the Ice Thickness camera and that obtained by an Electro-Magnetic inductive device in a selected time window. The results agree well with each other. Considering the advantages and disadvantages of each method, this demonstrates the benefits of combining redundant approaches for obtaining the ice thickness information with a higher degree of confidence.