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See detailHigh-precision photometry by telescope defocusing - VII. The ultrashort period planet WASP-103
Southworth, J.; Mancini, L.; Ciceri, S. et al

in Monthly Notices of the Royal Astronomical Society (2014), 447(1), 711-721

We present 17 transit light curves of the ultrashort period planetary system WASP-103, a strong candidate for the detection of tidally-induced orbital decay. We use these to establish a high-precision ... [more ▼]

We present 17 transit light curves of the ultrashort period planetary system WASP-103, a strong candidate for the detection of tidally-induced orbital decay. We use these to establish a high-precision reference epoch for transit timing studies. The time of the reference transit mid-point is now measured to an accuracy of 4.8 s, versus 67.4 s in the discovery paper, aiding future searches for orbital decay. With the help of published spectroscopic measurements and theoretical stellar models, we determine the physical properties of the system to high precision and present a detailed error budget for these calculations. The planet has a Roche lobe filling factor of 0.58, leading to a significant asphericity; we correct its measured mass and mean density for this phenomenon. A high-resolution Lucky Imaging observation shows no evidence for faint stars close enough to contaminate the point spread function of WASP-103. Our data were obtained in the Bessell RI and the SDSS griz passbands and yield a larger planet radius at bluer optical wavelengths, to a confidence level of 7.3σ. Interpreting this as an effect of Rayleigh scattering in the planetary atmosphere leads to a measurement of the planetary mass which is too small by a factor of 5, implying that Rayleigh scattering is not the main cause of the variation of radius with wavelength. © 2014 The Authors. [less ▲]

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See detailHigh-precision photometry by telescope defocussing - II. The transiting planetary system WASP-4
Southworth, John; Hinse, T. C.; Burgdorf, M. J. et al

in Monthly Notices of the Royal Astronomical Society (2009)

We present and analyse light curves of four transits of the Southern hemisphere extrasolar planetary system WASP-4, obtained with a telescope defocused so the radius of each point spread function was 17 ... [more ▼]

We present and analyse light curves of four transits of the Southern hemisphere extrasolar planetary system WASP-4, obtained with a telescope defocused so the radius of each point spread function was 17 arcsec (44 pixels). This approach minimizes both random and systematic errors, allowing us to achieve scatters of between 0.60 and 0.88 mmag per observation over complete transit events. The light curves are augmented by published observations and analysed using the JKTEBOP code. The results of this process are combined with theoretical stellar model predictions to derive the physical properties of the WASP-4 system. We find that the mass and radius of the planet are M[SUB]b[/SUB] = 1.289[SUP]+0.090[/SUP][SUB]-0.090[/SUB][SUP]+0.039[/SUP][SUB]-0.000[/SUB]M[SUB]Jup[/SUB] and R[SUB]b[/SUB] = 1.371[SUP]+0.032[/SUP][SUB]-0.035[/SUB][SUP]+0.021[/SUP][SUB]-0.000[/SUB]R[SUB]Jup[/SUB], respectively (statistical and systematic uncertainties). These quantities give a surface gravity and density of g[SUB]b[/SUB] = 17.03[SUP]+0.97[/SUP][SUB]-0.54[/SUB]ms[SUP]-2[/SUP] and rho[SUB]b[/SUB] = 0.500[SUP]+0.032[/SUP][SUB]-0.021[/SUB][SUP]+0.000[/SUP][SUB]-0.008[/SUB] rho[SUB]Jup[/SUB], and fit the trends for short-period extrasolar planets to have relatively high masses and surface gravities. WASP-4 is now one of the best-quantified transiting extrasolar planetary systems, and significant further progress requires improvements to our understanding of the physical properties of low-mass stars. Based on data collected by MiNDSTEp with the Danish 1.54m telescope at the ESO La Silla Observatory. E-mail: jkt@astro.keele.ac.uk â ¡ Royal Society University Research Fellow. [less ▲]

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See detailHigh-precision photometry by telescope defocussing - VI. WASP-24, WASP-25 andWASP-26*
Southworth, J.; Hinse, T. C.; Burgdorf, M. et al

in Monthly Notices of the Royal Astronomical Society (2014), 444(1), 776-789

We present time series photometric observations of 13 transits in the planetary systems WASP-24, WASP-25 and WASP-26. All three systems have orbital obliquity measurements, WASP-24 andWASP-26 have been ... [more ▼]

We present time series photometric observations of 13 transits in the planetary systems WASP-24, WASP-25 and WASP-26. All three systems have orbital obliquity measurements, WASP-24 andWASP-26 have been observed with Spitzer, andWASP-25 was previously comparatively neglected. Our light curves were obtained using the telescope-defocussing method and have scatters of 0.5-1.2 mmag relative to their best-fitting geometric models. We use these data to measure the physical properties and orbital ephemerides of the systems to high precision, finding that our improved measurements are in good agreement with previous studies. High-resolution Lucky Imaging observations of all three targets show no evidence for faint stars close enough to contaminate our photometry. We confirm the eclipsing nature of the star closest to WASP-24 and present the detection of a detached eclipsing binary within 4.25 arcmin of WASP-26. © 2014 The Authors. [less ▲]

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See detailHigh-Precision Spectroscopy of Pulsating Stars
Aerts, C.; Hekker, S.; Desmet, M. et al

in Precision Spectroscopy in Astrophysics, Proceedings of the ESO/Lisbon/Aveiro Conference held in Aveiro, Portugal, 11-15 September 2006. (2008)

We review methodologies currently available to interprete time series of high-resolution high-S/N spectroscopic data of pulsating stars in terms of the kind of (non-radial) modes that are excited. We ... [more ▼]

We review methodologies currently available to interprete time series of high-resolution high-S/N spectroscopic data of pulsating stars in terms of the kind of (non-radial) modes that are excited. We illustrate the drastic improvement of the detection treshold of line-profile variability thanks to the advancement of the instrumentation over the past two decades. This has led to the opportunity to interprete line-profile variations with amplitudes of order m/s, which is a factor 1000 lower than the earliest line-profile time series studies allowed for. [less ▲]

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See detailHigh-pressure study of the beta-to-alpha transition in Ga2O3
Machon, D.; McMillan, P. F.; Xu, Bin ULiege et al

in Physical Review. B, Condensed Matter and Materials Physics (2006), 73(9),

The high-pressure behavior of Ga2O3 is studied up to 40 GPa using synchrotron x-ray diffraction and Raman spectroscopy in diamond anvil cells. A phase transformation from the monoclinic beta-phase (C2/m ... [more ▼]

The high-pressure behavior of Ga2O3 is studied up to 40 GPa using synchrotron x-ray diffraction and Raman spectroscopy in diamond anvil cells. A phase transformation from the monoclinic beta-phase (C2/m) is observed at a pressure above 20-22 GPa. The high-pressure polymorph is identified as the alpha-phase that is isostructural with corundum (R (3) over barc symmetry) from the x-ray diffraction data. However, considerable anion disorder is indicated by the appearance of broad bands in the Raman spectra. The experimental results are complemented by ab initio theoretical calculations of the energetics of the two structures and the lattice dynamics. [less ▲]

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See detailHigh-quality remeshing using harmonic maps
Geuzaine, Christophe ULiege; Marchandise, E.; Remacle, J.-F.

in Proceedings of the 5th Advanced Computational Electromagnetics workshop (2010, July)

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See detailHigh-Quality Remeshing using Harmonic Maps
Geuzaine, Christophe ULiege

Scientific conference (2010, March 30)

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See detailHigh-Quality Surface Remeshing Using Harmonic Maps
Remacle, J.-F.; Geuzaine, Christophe ULiege; Compère, G. et al

in International Journal for Numerical Methods in Engineering (2010), 83(4), 403-425

Detailed reference viewed: 67 (3 ULiège)
See detailHigh-quality thin graphene films from fast electrochemical exfoliation
Aqil, Abdelhafid ULiege; Ouhib, Farid ULiege; Detrembleur, Christophe ULiege et al

Poster (2013, November)

Many methods have been developed in the last few decades to obtain high-quality graphene thin sheets. They are based on very different physicochemical processes. Here we demonstrate a novel one step and ... [more ▼]

Many methods have been developed in the last few decades to obtain high-quality graphene thin sheets. They are based on very different physicochemical processes. Here we demonstrate a novel one step and simple electrografting acrylate monomer method to exfoliate highly oriented pyrolytic graphite (HOPG) into thin nanoplatelets and even down to the single graphene sheet level. Among the high research activity in the area of surface modification, electrografting is a very powerful method which has received comparatively little attention. This is surprising because this technique has many attractive features for modification of conducting or semi-conducting surfaces. The main interest of the electrografting process is to solve the recurrent problem of the organic/substrates interface weakness. The electrografting warranties a robust polymer/substrates interface and offers the possibility to tailor the functionality of the grafted polymer film opening the door to a wide range of demanding technological applications. The graphene sheets obtained through electrografting process give a stable suspension in dimethyl formamide (DMF), and they can self-precipitate on the surface of substrates after adding water as an antisolvent due to their strong surface hydrophobicity. Interestingly, the continuous films obtained exhibit ultratransparency (∼98% transmittance), and the lateral size of the exfoliated graphene sheets observed by AFM ~1nm. Raman and TEM characterizations corroborate that the graphene sheets exfoliated by our electrochemical method preserve the intrinsic structure of grapheme and give preferentially monolayered graphene sheets. The electrochemical behaviour of the acrylate monomer grafted graphene sheets was evaluated in lithium-half cells with no addition of conductive additive or binder. The PAN grafted graphene dispersed in DMF was coated on Cu foil and dried in a vacuum oven at 55°C for 12h. After 200 cycles, the reversible capacity was still kept at 300mAh/g at the current density of 50mA/g. These results indicate that the prepared high quality graphene sheets possess good electrochemical performances for lithium storage. This work provides an efficient approach to obtain high-quality, cost-effective, and scalable production of “graphene ink”, which may pave a way toward future applications in lithium- ion batteries. [less ▲]

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See detailHigh-rate of multiple genital HPV infections detected by DNA hybridization
Lauricella-Lefèbvre, M. A.; Piette, Jacques ULiege; Lifrange, Eric ULiege et al

in Journal of Medical Virology (1992), 36(4), 265-270

Cervical smears collected from 450 patients involved in a clinical follow-up of cervical human papillomaviruses (HPV) infections were screened for the presence of HPV 6b, 11, 16, and 18 DNA by both dot ... [more ▼]

Cervical smears collected from 450 patients involved in a clinical follow-up of cervical human papillomaviruses (HPV) infections were screened for the presence of HPV 6b, 11, 16, and 18 DNA by both dot blot and southern blot hybridization methods. Using very high stringency hybridization assays, the four HPV types could be easily distinguished by dot blotting. After a preliminary clinical sorting, 42.9% of the samples were found to be HPV-positive. Among the samples infected by a single HPV, type 16 was the most frequent (25.4% of the positive samples) followed by 6b (19.7%), 11 (8.3%), and 18 (7.2%). Double or even multiple infections by the different HPV types were detected at a very high rate (39.4% of the positive samples). [less ▲]

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See detailHigh-resolution climate and land surface interactions modeling over Belgium: current state and decennial scale projections
Jacquemin, Ingrid ULiege; Henrot, Alexandra-Jane ULiege; Beckers, Veronique et al

Poster (2016, April 21)

The interactions between land surface and climate are complex. Climate changes can affect ecosystem structure and functions, by altering photosynthesis and productivity or inducing thermal and hydric ... [more ▼]

The interactions between land surface and climate are complex. Climate changes can affect ecosystem structure and functions, by altering photosynthesis and productivity or inducing thermal and hydric stresses on plant species. These changes then impact socio-economic systems, through e.g., lower farming or forestry incomes. Ultimately, it can lead to permanent changes in land use structure, especially when associated with other non-climatic factors, such as urbanization pressure. These interactions and changes have feedbacks on the climate systems, in terms of changing: (1) surface properties (albedo, roughness, evapotranspiration, etc.) and (2) greenhouse gas emissions (mainly CO2, CH4, N2O). In the framework of the MASC project (« Modelling and Assessing Surface Change impacts on Belgian and Western European climate »), we aim at improving regional climate model projections at the decennial scale over Belgium and Western Europe by combining high-resolution models of climate, land surface dynamics and socio-economic processes. The land surface dynamics (LSD) module is composed of a dynamic vegetation model (CARAIB) calculating the productivity and growth of natural and managed vegetation, and an agent-based model (CRAFTY), determining the shifts in land use and land cover. This up-scaled LSD module is made consistent with the surface scheme of the regional climate model (RCM: ALARO) to allow simulations of the RCM with a fully dynamic land surface for the recent past and the period 2000-2030. In this contribution, we analyze the results of the first simulations performed with the CARAIB dynamic vegetation model over Belgium at a resolution of 1km. This analysis is performed at the species level, using a set of 17 species for natural vegetation (trees and grasses) and 10 crops, especially designed to represent the Belgian vegetation. The CARAIB model is forced with surface atmospheric variables derived from the monthly global CRU climatology or ALARO outputs (from a 4 km resolution simulation) for the recent past and the decennial projections. Evidently, these simulations lead to a first analysis of the impact of climate change on carbon stocks (e.g., biomass, soil carbon) and fluxes (e.g., gross and net primary productivities (GPP and NPP) and net ecosystem production (NEP)). The surface scheme is based on two land use/land cover databases, ECOPLAN for the Flemish region and, for the Walloon region, the COS-Wallonia database and the Belgian agricultural statistics for agricultural land. Land use and land cover are fixed through time (reference year: 2007) in these simulations, but a first attempt of coupling between CARAIB and CRAFTY will be made to establish dynamic land use change scenarios for the next decades. A simulation with variable land use would allow an analysis of land use change impacts not only on crop yields and the land carbon budget, but also on climate relevant parameters, such as surface albedo, roughness length and evapotranspiration towards a coupling with the RCM. [less ▲]

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See detailHigh-resolution Climatology of the North-East Atlantic using Data-Interpolating Variational Analysis
Troupin, Charles ULiege; Machín, Francisco; Ouberdous, Mohamed ULiege et al

Conference (2009, April 21)

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See detailHigh-resolution Climatology of the northeast Atlantic using Data-Interpolating Variational Analysis (DIVA)
Troupin, Charles ULiege; Machin, Francis; Ouberdous, Mohamed ULiege et al

in Journal of Geophysical Research (2010), 115(C08005), 20

Numerous climatologies are available at different resolutions and cover various parts of the global ocean. Most of them have a resolution too low to represent suitably regional processes and the methods ... [more ▼]

Numerous climatologies are available at different resolutions and cover various parts of the global ocean. Most of them have a resolution too low to represent suitably regional processes and the methods for their construction are not able to take into account the influence of physical effects (topographic constraints, boundary conditions, advection, etc.). A high-resolution atlas for temperature and salinity is developed for the northeast Atlantic Ocean on 33 depth levels. The originality of this climatology is twofold: (1) For the data set, data are collected on all major databases and aggregated to lead to an original data collection without duplicates, richer than the World Ocean Database 2005, for the same region of interest. (2) For the method, climatological fields are constructed using the variational method Data-Interpolating Variational Analysis. The formulation of the latter allows the consideration of coastlines and bottom topography, and has a numerical cost almost independent on the number of observations. Moreover, only a few parameters, determined in an objective way, are necessary to perform an analysis. The results show overall good agreement with the widely used World Ocean Atlas, but also reveal significant improvements in coastal areas. Error maps are generated according to different theories and emphasize the importance of data coverage for the creation of such climatological fields. Automatic outlier detection is performed, and its effects on the analysis are examined. The method presented here is very general and not dependent on the region, hence it may be applied for creating other regional atlas in different zones of the global ocean. [less ▲]

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See detailHigh-resolution clutter-power estimation for range-dependence compensation in conformal-array STAP
Ries, Philippe; Lapierre, Fabian D.; Lesturgie, Marc et al

Conference (2008)

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See detailHigh-resolution diatom/clay record in Lake Baikal from grey scale, and magnetic susceptibility over Holocene and Termination I
Boes, Xavier; Piotrowska, Natalia; Fagel, Nathalie ULiege

in Global and Planetary Change (2005), 46(1-4), 299-313

Tracing past climate signals from Lake Baikal sediments with a "multi-annual' resolution by conventional techniques is a difficult challenge since the sedimentation rates from Termination I up to the ... [more ▼]

Tracing past climate signals from Lake Baikal sediments with a "multi-annual' resolution by conventional techniques is a difficult challenge since the sedimentation rates from Termination I up to the present range from 0.004 to 0.17 mm/year. In this paper, climate signals are reconstructed from three continuous sediment records from Vydrino Shoulder and Posolsky Bank in the Southern Basin, and Continent Ridge in the Northern Basin. For each coring site, a calendar age model was constructed using calibrated radiocarbon ages. The magnetic susceptibility is used to better constrain the age models over OIS4 to OIS1 The cores have been hardened using polymerized technique in order to allow the easy cut of thin sections that contain evidence for narrow biogenic/clayey laminations. The grey scale taken from the thin sections is used here as a high-resolution proxy record of diatom/clay ratio. The grey density values are qualitatively interpreted against the sediment components by optical microscopy from the thin sections. In the Northern Basin, the Continent station provides the best age model and sediment resolution over the Termination I period. In particular, four optima (i.e. Bolling, Allerod, Atlantic, and Subboreal) are indicated by substantial increases of the grey scale, whereas cold periods like the Younger Dryas correspond to lower grey scale values. We emphasize that the short-term variations in the grey scale at 20 mu m resolution could correspond to short climate responses in Lake Baikal sediments. (C) 2004 Elsevier B.V. All rights reserved. [less ▲]

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See detailHigh-resolution epiluminescence colorimetry of striae distensae.
Hermanns, J.-F.; Pierard, Gérald ULiege

in Journal of the European Academy of Dermatology & Venereology (2006), 20(3), 282-7

BACKGROUND: Colours of striae distensae are often different from that of the surrounding skin. A close look using dermoscopy discloses distinct patterns of melanized networks at these sites. The aim of ... [more ▼]

BACKGROUND: Colours of striae distensae are often different from that of the surrounding skin. A close look using dermoscopy discloses distinct patterns of melanized networks at these sites. The aim of the study was to design a method of high-\resolution analytical analysis of the skin colours using the combination of photographic dermoscopy and small field reflectance colorimetry. METHODS: Clinical photographs were taken from striae distensae and their surrounding skin using a Dermaphot (Heine Optotechnik, Hersching, Germany). A final magnification of 125x was obtained on paper photographs. The reflectance colorimeter Visi-Chroma VC-100 (Biophotonics, Lessines, Belgium) was used to measure colours of the pigmentary networks in the L*a*b* system. Differential colour parameters (deltaE*ab, deltaL*, deltaa*, deltab*) were calculated for each case between the lesional and the surrounding normal skin, and between the melanized reticulated pattern and the enclosed lighter areas. RESULTS: Objective colorimetric assessments distinguished four distinct types, namely striae albae, striae rubrae, striae caeruleae and striae nigrae. The latter peculiar hyperpigmented type of striae distensae was specifically identified by epiluminescence examination in dark-skinned subjects. The fine-melanized honeycomb network present on the adjacent intact skin was reshaped inside striae in a streaky pattern perpendicular to the striae axis. Strong linear correlations were found between all combinations of deltaL* and deltab* evaluating colours of the reticulated and the honeycomb alveolar patterns both inside and outside the striae distensae. By contrast, no correlations were found between deltaa* and the other colorimetric parameters. CONCLUSION: The direct and/or indirect influences of melanocyte mechanobiology appear to have a prominent effect on the various colours of striae distensae. [less ▲]

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See detailHigh-Resolution GC Coupled to High-Resolution MS in the Analysis of Dioxins and Related Substances, Principles and Applications
Eppe, Gauthier ULiege; De Pauw, Edwin ULiege; Focant, Jean-François ULiege

in Niessen, W. M. A. (Ed.) The Encyclopedia of Mass Spectrometry, Volume 8, Hyphenated Methods (2006)

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See detailHigh-resolution gene maps of horse chromosomes 14 and 21: Additional insights into evolution and rearrangements of HSA5 homologs in mammals.
Goh, Glenda; Raudsepp, T; Durkin, Keith ULiege et al

in Genomics (2007), 89

High-resolution physically ordered gene maps for equine homologs of human chromosome 5 (HSA5), viz., horse chromosomes 14 and 21 (ECA14 and ECA21), were generated by adding 179 new loci (131 gene-specific ... [more ▼]

High-resolution physically ordered gene maps for equine homologs of human chromosome 5 (HSA5), viz., horse chromosomes 14 and 21 (ECA14 and ECA21), were generated by adding 179 new loci (131 gene-specific and 48 microsatellites) to the existing maps of the two chromosomes. The loci were mapped primarily by genotyping on a 5000-rad horse × hamster radiation hybrid panel, of which 28 were mapped by fluorescence in situ hybridization. The approximately fivefold increase in the number of mapped markers on the two chromosomes improves the average resolution of the map to 1 marker/0.9 Mb. The improved resolution is vital for rapid chromosomal localization of traits of interest on these chromosomes and for facilitating candidate gene searches. The comparative gene mapping data on ECA14 and ECA21 finely align the chromosomes to sequence/gene maps of a range of evolutionarily distantly related species. It also demonstrates that compared to ECA14, the ECA21 segment corresponding to HSA5 is a more conserved region because of preserved gene order in a larger number of and more diverse species. Further, comparison of ECA14 and the distal three-quarters region of ECA21 with corresponding chromosomal segments in 50 species belonging to 11 mammalian orders provides a broad overview of the evolution of these segments in individual orders from the putative ancestral chromosomal configuration. Of particular interest is the identification and precise demarcation of equid/Perissodactyl-specific features that for the first time clearly distinguish the origins of ECA14 and ECA21 from similar-looking status in the Cetartiodactyls. [less ▲]

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See detailHigh-Resolution Limb Observations of Proton Aurora
Chua, D. H.; Dymond, K. F.; Budzien, S. A. et al

Conference (2003, December 01)

The interaction of precipitating protons in the upper atmosphere involves charge exchange, ionization, elastic and inelastic collisions, and the deposition of energy from the bottom of the F-region to the ... [more ▼]

The interaction of precipitating protons in the upper atmosphere involves charge exchange, ionization, elastic and inelastic collisions, and the deposition of energy from the bottom of the F-region to the D-region of the ionosphere. These processes and the transport of incident protons through this range of altitudes has been described through a variety of modeling techniques but there has been a dearth of altitude-resolved observations of proton precipitation with which to validate such models. We present new limb observations of Doppler-shifted Lyman-α proton aurora emissions obtained by the High-resolution Ionospheric and Thermospheric Spectrograph (HITS) aboard the Advanced Research and Global Observation Satellite (ARGOS) that fill this niche. HITS performs limb scans that include tangent altitudes between 90 km and 400 km with approximately 5 km vertical resolution. The Doppler shifts of the proton aurora Lyman-α emissions are measured with 1.5 Angstrom resolution and are used to infer mean energies of the incident protons as a function of altitude. Observed energy-range (dE/dz) relations are compared to those predicted by a Monte Carlo simulation of proton transport in the upper atmosphere. [less ▲]

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See detailHigh-resolution measurements and modelling of the Cape Ghir upwelling filament during the CAIBEX cruise
Troupin, Charles ULiege; Beckers, Jean-Marie ULiege; Sangrà, Pablo et al

Conference (2010, April 26)

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