369 research outputs found
Characterisation of toxic gaseous emissions from industrial solid waste landfills
International audienceIn France, Hazardous Industrial Waste, once stabilized, are buried in specific landfills. As for all polluting activities, these facilities must report to the EPER Register their toxic gaseous emissions, expressed in mass per year, as soon as they exceed threshold limit values. Campaigns were conducted on two different hazardous waste landfills in order to establish if these facilities needed to report to EPER register. Global fluxes of gaseous components were measured by means of an FID (hydrocarbons) and a PID (halocarbons, aromatics and some non-organic compounds). Specific concentrations of aromatic (BTEX) and chlorinated hydrocarbons were also measured. Gaseous emissions were generally very low. Emissions were only detected for young and medium-aged layers, between 1 day and 3 months old. Due to these low emissions, and to the small surfaces involved, the two landfills do not fall under the EPER emission Register
Des dalles ornĂ©es durant le Campaniforme et lâĂąge du Bronze ancien en Bretagne. Mythe ou rĂ©alitĂ© ?
Since the pioneering work of P. Du Chatellier (1901a et b), it has generally been recognised that
there is a form of art in the Early Bronze Age of Brittany, exemplified by a few stone slabs with
cup-marks and other simple motifs. After the Second World War, rescue archaeology provided
new data and enabled J. Briard in the 1990s to confirm the reality of these Early Bronze Age cupmarks (Le Roux, 1971 ; Briard, 1984 ; Briard et al., 1995). In a study undertaken on a larger scale,
C. Burgess (1990) deduced that the slabs with cup-marks in Early Bronze Age graves were all
cases of re-use from earlier periods. In order to obtain a clearer picture, we decided to take a fresh
look and reassess the question without any preconceived ideas, limiting our geographical scope to
Brittany. First of all, we listed all decorated slabs found in Bronze Age contexts, as well as
integrating possible and probable contexts. The corpus is quite small because only thirteen sites
have yielded decorated stones in secure Beaker or Early Bronze Age contexts, to which we can
add eleven more doubtful sites (fig. 1). Almost all come from graves but there is also one dwelling
(Beg ar Loued, MolĂšne Island, FinistĂšre). These decorated slabs include : large slabs with cupmarks only (fig. 4, no. 4 ; fig. 10, nos. 2 and 3 ; fig. 11 ; fig. 12 and fig. 13, no. 4), large slabs with
cup-marks and associated patterns (fig. 2 ; fig. 3 ; fig. 4, nos. 1 to 3 ; fig. 5 ; fig. 10, no. 1 ; fig. 13,
nos. 1 to 3), small stones with cup-marks (figs. 7 and 8) and more figurative images, i. e.
anthropomorphic stelae, hafted axes and nipple (fig. 6 ; fig. 7, no. 1 ; and fig. 9). Four slabs are
distinguished by perforations (fig. 4, nos. 2 to 4 ; fig. 12, no. 1). The decorated slabs show a
variety of re-employment contexts : slabs reused as capstones, walls or surrounds, rubble stones
reused in cairns, walls or paving. The decorated surfaces are generally turned to the outside but
can also be hidden in the inside of the tombs. Some are placed with burials under barrows and are
thus removed from the eyes of the living. The decorated stones can be used unmodified, broken or
reworked with grooves or perforations. Longitudinal and transversal grooves were certainly made
by the Early Bronze Age people in order to join the sides of the grave and make it airtight ; this
kind of cist is well known for this period in Brittany (Briard, 1984). The nature of the perforations is
still puzzling but one might suggest that it was a symbolic hole enabling the soul of the deceased
to come and go (Chatellier, 1904 ; Eliade, 1949). In order to assess the originality of decorated
slabs found in Early Bronze Age contexts, we have undertaken as comprehensive as possible an
inventory of stones with cup-marks in Neolithic megalithic graves in Brittany. This topic has not
previously received much attention from researchers (PĂ©quart et al., 1927, p. 74 ; Shee Twohig,
1981, p. 54). Our inventory includes forty megalithic graves, which have yielded a total of seventysix slabs with cup-marks (table 3 ; fig. 20). Some of these stones are clearly in a re-employment
position, as the cup-marks are located on the hidden sides of these megalithic structures. Thus,
when cup-marks are associated with classical figures of megalithic art, there is no certainty that all
these decorations are contemporaneous. In some other cases, cup-marks form an integral part of
certain recurrent depictions, such as the crest motif (fig. 19, no. 9 ; fig. 21, no. 2). More rarely, they
are associated with single circles or circles with rays (fig. 19, nos. 3 and 10). Through the Neolithic
period, there is little evidence for a specific style in cup-marking, except for a few anecdotal
patterns such as a square and circle depicted by cup-marks or a panel of narrowed cup-marks,
which most likely date from the Middle Neolithic 2. The most distinctive elements are associated
patterns, which are especially common in passage tombs in the Carnac area (Kercado, Le Lizo,
Mané-Lud, Petit Mont) but also at Renongar in south-western FinistÚre (fig. 19). On the contrary,
slabs with cup-marks dating from the Middle Neolithic 1 and the Late Neolithic show less originality
in cup-mark patterns. This also applies to Early Bronze Age decorated stones. Only the footshaped mark from the Saint-Ouarno slab (fig. 10, no. 1) and the pair of pointed cupmarks from the
Mezcouez slab (fig. 5, no. 2) appear to be specific to this period. There is however a foot-shaped
mark, albeit with a different type of execution (in bas-relief), in the passage tomb of Petit Mont IIIA,
Arzon, Morbihan (Shee Twohig, 1981). As regards the pair of pointed cup-marks, a similar pattern
is attested as a single element in Neolithic graves. Comparison with the Neolithic corpus of slabs
with cup-marks does not enable us to identify types or patterns of cupmarks specific to the Early
Bronze Age. It is thus difficult to defend the idea of a development of cup-mark art at this time in
Brittany. This is also confirmed by the large numbers of slabs with cup-marks from Neolithic
funerary contexts (102), compared with the rare discoveries from Early Bronze Age graves (11 to
17). Many of these decorated stones reused in Early Bronze Age burials could come from
outcrops with cup-marks (fig. 16) or from Neolithic monuments, as is also attested by the re-employment of
what are clearly Neolithic images (anthropomorphic figures, hafted axes ; fig. 6). Nevertheless, a group of
four slabs with cup-marks is distinguished by perforations, previously unknown for Neolithic rock art, and by
the interlinked representations of cup-marks and geometrical shapes, in contrast to Neolithic motifs that are
usually juxtaposed. We suggest that this small group can be attributed to the Early Bronze Age or even to
the Final Neolithic. Furthermore, the small slabs, such as the six found in the Beg ar Loued settlement or
the Cruguel barrow example (fig. 8), stand out by their small size and they could also be related to the Early
Bronze Age
Effects of Phenol Addition on Oil Extraction from Moroccan Oil Shale by Supercritical Toluene
In the present work, the effect of phenol on the supercritical extraction of the organic matter from Tarfaya's oil shale with toluene was evaluated. The experimental results showed clearly that phenol had a significant effect on the yield and the composition of the oils obtained. Moreover, it was shown that phenol was a very efficient modifier for oil shale, giving a good yield of recovery and a suitable maturation of the organic matter. The pitches prepared by mixing phenol and toluene contain more aromatics and have a high char yield at 950 °C compared to those obtained by extraction with supercritical toluene alone
Comparison of chemical and physical activation processes at obtaining adsorbents from moroccan oil shale
Within the Moroccan natural resources valorisation scheme, new
adsorbents have been prepared from oil shale by chemical and physical
activation processes. The activation process the authors have developed in
this study give effective adsorbent materials. In view of the physico-chemical
properties of these materials and application to the treatment of water loaded
with a metal (Cr6+ ion) or organic (methylene blue (MB)) pollutant, it is
concluded that the chemical activation process of oil shale at low temperature
(250 °C) affords the best material. The materialâs yield is good in comparison
with the physical activation at the same temperature and the process is energy
saving differently from that at 450 °C. Moreover, the chemical activation of
oil shale with phosphoric acid at 250 °C produces a material with a good
yield (about 70%), a high specific surface area (approximately 600 m2
/g) and a highly porous structure, which gives it a high retention of methylene blue
and the Cr6+ ion
Solid confirmation of the broad DIB around 864.8 nm using stacked GaiaâRVS spectra
Context. Studies of the correlation between different diffuse interstellar bands (DIBs) are important for exploring their origins. However, the GaiaâRVS spectral window between 846 and 870 nm contains few DIBs, the strong DIB at 862 nm being the only convincingly confirmed one. /
Aims. Here we attempt to confirm the existence of a broad DIB around 864.8 nm and estimate its characteristics using the stacked GaiaâRVS spectra of a large number of stars. We study the correlations between the two DIBs at 862 nm (λ862) and 864.8 nm (λ864.8), as well as the interstellar extinction. /
Methods. We obtained spectra of the interstellar medium (ISM) absorption by subtracting the stellar components using templates constructed from real spectra at high Galactic latitudes with low extinctions. We then stacked the ISM spectra in Galactic coordinates (â,ââb) â pixelized by the HEALPix scheme â to measure the DIBs. The stacked spectrum is modeled by the profiles of the two DIBs, Gaussian for λ862 and Lorentzian for λ864.8, and a linear continuum. We report the fitted central depth (CD), central wavelength, equivalent width (EW), and their uncertainties for the two DIBs. /
Results. We obtain 8458 stacked spectra in total, of which 1103 (13%) have reliable fitting results after applying numerous conservative filters. This work is the first of its kind to fit and measure λ862 and λ864.8 simultaneously in cool-star spectra. Based on these measurements, we find that the EWs and CDs of λ862 and λ864.8 are well correlated with each other, with Pearson coefficients (rp) of 0.78 and 0.87, respectively. The full width at half maximum (FWHM) of λ864.8 is estimated as 1.62â
屉
0.33 nm which compares to 0.55â
屉
0.06 nm for λ862. We also measure the vacuum rest-frame wavelength of λ864.8 to be λ0â=â864.53â
屉
0.14 nm, smaller than previous estimates. /
Conclusions. We find solid confirmation of the existence of the DIB around 864.8 nm based on an exploration of its correlation with λ862 and estimation of its FWHM. The DIB λ864.8 is very broad and shallow. That at λ862 correlates better with E(BPâ
ââ
RP) than λ864.8. The profiles of the two DIBs could strongly overlap with each other, which contributes to the skew of the λ862 profile
<i>Gaia</i> Data Release 1. Summary of the astrometric, photometric, and survey properties
Context. At about 1000 days after the launch of Gaia we present the first Gaia data release, Gaia DR1, consisting of astrometry and photometry for over 1 billion sources brighter than magnitude 20.7.
Aims. A summary of Gaia DR1 is presented along with illustrations of the scientific quality of the data, followed by a discussion of the limitations due to the preliminary nature of this release.
Methods. The raw data collected by Gaia during the first 14 months of the mission have been processed by the Gaia Data Processing and Analysis Consortium (DPAC) and turned into an astrometric and photometric catalogue.
Results. Gaia DR1 consists of three components: a primary astrometric data set which contains the positions, parallaxes, and mean proper motions for about 2 million of the brightest stars in common with the HIPPARCOS and Tycho-2 catalogues â a realisation of the Tycho-Gaia Astrometric Solution (TGAS) â and a secondary astrometric data set containing the positions for an additional 1.1 billion sources. The second component is the photometric data set, consisting of mean G-band magnitudes for all sources. The G-band light curves and the characteristics of âŒ3000 Cepheid and RR-Lyrae stars, observed at high cadence around the south ecliptic pole, form the third component. For the primary astrometric data set the typical uncertainty is about 0.3 mas for the positions and parallaxes, and about 1 mas yrâ1 for the proper motions. A systematic component of âŒ0.3 mas should be added to the parallax uncertainties. For the subset of âŒ94 000 HIPPARCOS stars in the primary data set, the proper motions are much more precise at about 0.06 mas yrâ1. For the secondary astrometric data set, the typical uncertainty of the positions is âŒ10 mas. The median uncertainties on the mean G-band magnitudes range from the mmag level to âŒ0.03 mag over the magnitude range 5 to 20.7.
Conclusions. Gaia DR1 is an important milestone ahead of the next Gaia data release, which will feature five-parameter astrometry for all sources. Extensive validation shows that Gaia DR1 represents a major advance in the mapping of the heavens and the availability of basic stellar data that underpin observational astrophysics. Nevertheless, the very preliminary nature of this first Gaia data release does lead to a number of important limitations to the data quality which should be carefully considered before drawing conclusions from the data
Liquid Biopsy in Non-Small Cell Lung Cancer (NSCLC)
Lung cancer is the leading cause of cancer deaths worldwide. To date, the gold standard for the molecular analysis of a patient affected by NSCLC is the tissue biopsy. The discovery of activating mutations and rearrangements in specific genes has revolutionized the therapeutic approaches of lung cancer over the last years. For this reason, a strict \u201cmolecular follow-up\u201d is mandatory to evaluate patient\u2019s disease evolution. Indeed, liquid biopsy has raised as the \u201cnew ambrosia of researchers\u201d as it could help clinicians to identify both prognostic and predictive biomarkers in a more accessible way. Liquid biopsy analysis can be used in different moments starting from diagnosis to relapse, earning multiple clinical meanings, offering thus a noninvasive but valid method to detect actionable mutations. Although the implementation of both exosomes and CTCs in clinical practice is several steps back, new advances and discoveries make them, together with the ctDNA, a very promising tool. In the following chapter we will discuss the recent advances of liquid biopsy in NSCLC highlighting the possible clinical utility of CTCs, ctDNA and exosomes
Ultracool dwarfs in Gaia DR3
Aims. In this work we use the Gaia DR3 set of ultracool dwarf candidates and
complement the Gaia spectrophotometry with additional photometry in order to
characterise its global properties. This includes the inference of the
distances, their locus in the Gaia colour-absolute magnitude diagram and the
(biased through selection) luminosity function in the faint end of the Main
Sequence. We study the overall changes in the Gaia RP spectra as a function of
spectral type. We study the UCDs in binary systems, attempt to identify
low-mass members of nearby young associations, star forming regions and
clusters, and analyse their variability properties. Results. We detect 57
young, kinematically homogeneous groups some of which are identified as well
known star forming regions, associations and clusters of different ages. We
find that the primary members of 880 binary systems with a UCD belong mainly to
the thin and thick disk components of the Milky Way. We identify 1109 variable
UCDs using the variability tables in the Gaia archive, 728 of which belong to
the star forming regions defined by HMAC. We define two groups of variable UCDs
with extreme bright or faint outliers. Conclusions. The set of sources
identified as UCDs in the Gaia archive contains a wealth of information that
will require focused follow-up studies and observations. It will help to
advance our understanding of the nature of the faint end of the Main Sequence
and the stellar/substellar transition.Comment: Accepted by Astronomy and Astrophysics. 29 pages, 20 figures plus 3
appendice
Ăvolution de la contribution française Ă l'upgrade de LHCb
Ce document décrit l'évolution de la contribution française à l'upgrade de LHCb. Il s'inscrit dans le prolongement de la Lettre d'Intention [1], du Framework TDR [2], du document soumis au Conseil scientifique de l'IN2P3 le 21 juin 2012 [3], et des Technical Design Reports soumis au LHCC en novembre 2013 [4, 5]. Ces derniers concernent le détecteur de vertex et les détecteurs utilisés dans l'identification des particules. La contribution française s'est cristallisée autour de quatre grands projets : l'électronique front-end des calorimÚtres et du trajectographe à fibres scintillantes, le systÚme de déclenchement de premier niveau et la carte de lecture à 40MHz commune à l'ensemble des sous-systÚmes. Dans ce document nous décrivons les contributions envisagées et les ressources nécessaires pour mener à bien ces projets
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