Éditeur(s) : HAL CCSD European Respiratory Society
Résumé : IF 8.332
International audience
The respiratory manifestations of eosinophilic granulomatosis with polyangiitis (EGPA) have not been studied in detail. In this retrospective multicentre study, EGPA was defined by asthma, eosinophilia and at least one new onset extra-bronchopulmonary organ manifestation of disease. The study population included 157 patients (mean±SD age 49.4±14.1 years), with a mean±SD blood eosinophil count of 7.4±6.4×109 L-1 at diagnosis. There was a mean±SD of 11.8±18.2 years from the onset of asthma to the diagnosis of EGPA, of 1.4±8.4 years from the first onset of peripheral eosinophilia to the diagnosis of EGPA, and of 7.4±6.4 years from EGPA diagnosis to the final visit. Despite inhaled and oral corticosteroid treatment, the severity of asthma increased 3-6 months before the onset of the systemic manifestations. Asthma was severe in 57%, 48%, and 56% of patients at diagnosis, at 3 years, and at the final visit, respectively. Persistent airflow obstruction was present in 38%, 30%, and 46% at diagnosis, at 3 years, and at the final visit, respectively. In EGPA, asthma is severe, antedates systemic manifestations by a mean of 12 years, and progresses to long-term persistent airflow obstruction despite corticosteroids in a large proportion of patients, which affects long-term management and morbidity. Copyright © 2016 ERS.
ISSN: 0903-1936

hal-01406073
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01406073
DOI : 10.1183/13993003.00097-2016
PUBMED : 27587545

Éditeur(s) : HAL CCSD American Diabetes Association
Résumé : International audience
OBJECTIVE: To compare incidences and risk factors for diabetes using seven definitions, with combinations of pharmacological treatment, fasting plasma glucose (FPG) ≥7.0 mmol/L, and HbA(1c) ≥6.5%. RESEARCH DESIGN AND METHODS: Participants aged 30-65 years from the Data from an Epidemiological Study on the Insulin Resistance Syndrome (DESIR) cohort were followed for 9 years. RESULTS: More men had incident diabetes as defined by FPG ≥7.0 mmol/L and/or treatment than by HbA(1c) ≥6.5% and/or treatment: 7.5% (140/1,867) and 5.3% (99/1,874), respectively (P < 0.009); for women incidences were similar: 3.2% (63/1,958) and 3.4% (66/1,954). Known risk factors predicted diabetes for almost all definitions. Among those with incident diabetes by FPG alone versus HbA(1c) alone, there were more men (78 vs. 35%), case patients were 8 years younger, and fewer were alcohol abstainers (12 vs. 35%) (all P < 0.005). A diabetes risk score discriminated well between those with and without incident diabetes for all definitions. CONCLUSIONS: In men, FPG definitions yielded more incident cases of diabetes than HbA(1c) definitions, in contrast with women. An FPG-derived risk score remained relevant for HbA(1c)-defined diabetes.
Diabetes Care

inserm-00739799
http://www.hal.inserm.fr/inserm-00739799
http://www.hal.inserm.fr/inserm-00739799/document
DOI : 10.2337/dc10-1581
PUBMED : 21346181

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The South Liaodong Peninsula massif is the easternmost Mesozoic Metamorphic Core Complex, recognized in Eastern China. It provides a good example of the combination of ductile shearing, synkinematic plutonism and polyphase exhumation. The Jurassic granodioritic plutons, located at the footwall of the detachment normal fault, and dated here at ca 160 Ma, recorded two different phases of cooling. A slow cooling regime of about 3-10°C/my prevailing before 122 Ma, was followed by a significant increase in cooling rate of about 40-55°C/my after that time. By contrast, a single fast cooling path was recorded by the Cretaceous monzogranite situated in the footwall of the detachment normal fault. This result indicates that the Jurassic and Cretaceous plutons recorded different exhumation processes: a Jurassic slow or negligible exhumation and a Cretaceous fast one assisted by normal faulting. These two cooling stages correspond to distinct geodynamic processes during the Jurassic and Cretaceous. Extensional tectonics seems not significant before Early Cretaceous. The second stage, dominated by an extensional regime which develops after ca 120 Ma, is tentatively correlated to the lithosphere removal of the North China Craton.
ISSN: 1367-9120

Droits : http://creativecommons.org/licenses/by-nc-nd/
insu-00528171
https://hal-insu.archives-ouvertes.fr/insu-00528171
https://hal-insu.archives-ouvertes.fr/insu-00528171/document
https://hal-insu.archives-ouvertes.fr/insu-00528171/file/Lin-JAsianEarthSciences-2010.pdf
DOI : 10.1016/j.jseaes.2010.09.007

Éditeur(s) : HAL CCSD Nature Publishing Group
Résumé : International audience
Treacher Collins/Franceschetti syndrome (TCS; OMIM 154500) is a disorder of craniofacial development belonging to the heterogeneous group of mandibulofacial dysostoses. TCS is classically characterized by bilateral mandibular and malar hypoplasia, downward-slanting palpebral fissures, and microtia. To date, three genes have been identified in TCS:,TCOF1, POLR1D, and POLR1C. We report a clinical and extensive molecular study, including TCOF1, POLR1D, POLR1C, and EFTUD2 genes, in a series of 146 patients with TCS. Phenotype-genotype correlations were investigated for 19 clinical features, between TCOF1 and POLR1D, and the type of mutation or its localization in the TCOF1 gene. We identified 92/146 patients (63%) with a molecular anomaly within TCOF1, 9/146 (6%) within POLR1D, and none within POLR1C. Among the atypical negative patients (with intellectual disability and/or microcephaly), we identified four patients carrying a mutation in EFTUD2 and two patients with 5q32 deletion encompassing TCOF1 and CAMK2A in particular. Congenital cardiac defects occurred more frequently among patients with TCOF1 mutation (7/92, 8%) than reported in the literature. Even though TCOF1 and POLR1D were associated with extreme clinical variability, we found no phenotype-genotype correlation. In cases with a typical phenotype of TCS, 6/146 (4%) remained with an unidentified molecular defect.
ISSN: 1098-3600

hal-01134364
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01134364
DOI : 10.1038/gim.2015.29
PUBMED : 25790162

Éditeur(s) : HAL CCSD Geojournal of tourism and geosites
Résumé : International audience
https://hal.archives-ouvertes.fr/hal-01625499

hal-01625499
https://hal.archives-ouvertes.fr/hal-01625499

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
The ENE-WSW Autun Shear Zone in the northeastern part of the French Massif Central has been interpreted previously as a dextral wrench fault. New field observations and microstructural analyses document a NE-SW stretching lineation that indicates normal dextral motions along this shear zone. Further east, similar structures are observed along the La Serre Shear Zone. In both areas, a strain gradient from leucogranites with a weak preferred orientation to highly sheared mylonites supports a continuous Autun-La Serre fault system. Microstructural observations, and shape and lattice-preferred orientation document high-temperature deformation and magmatic fabrics in the Autun and La Serre granites, whereas low- to intermediate-temperature fabrics characterize the mylonitic granite. Electron microprobe monazite geochronology of the Autun and La Serre granites yields a ca. 320 Ma age for pluton emplacement, while mica 40Ar-39Ar datings of the Autun granite yield plateau ages from 305 to 300 Ma. The ca. 300 Ma 40Ar-39Ar ages, obtained on micas from Autun and La Serre mylonites, indicate the time of the mylonitization. The ca. 15-Ma time gap between pluton emplacement and deformation along the Autun-La Serre fault system argue against a synkinematic pluton emplacement during late orogenic to postorogenic extension of the Variscan Belt. A ductile to brittle continuum of deformation is observed along the shear zone, with Lower Permian brittle faults controlling the development of sedimentary basins. These results suggest a two-stage Late Carboniferous extension in the northeastern French Massif Central, with regional crustal melting and emplacement of the Autun and La Serre leucogranites around 320 Ma, followed, at 305-295 Ma, by ductile shearing, normal brittle faulting, and subsequent exhumation along the Autun-La Serre transtensional fault system.
ISSN: 1437-3254

insu-00596918
https://hal-insu.archives-ouvertes.fr/insu-00596918
https://hal-insu.archives-ouvertes.fr/insu-00596918/document
https://hal-insu.archives-ouvertes.fr/insu-00596918/file/Article_Morvan_v_INIST.pdf
DOI : 10.1007/s00531-011-0673-z

Éditeur(s) : HAL CCSD
Résumé : International audience
o abstract
Revue Des Maladies Respiratoires

hal-01647076
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01647076
DOI : 10.1016/j.rmr.2017.07.022
PUBMED : 28935495

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Regional-scale deformation taking place in a strongly anisotropic, yet homogeneous metapelitic protolith during an apparently single tectonic event was systematically investigated as a function of the distance to the main tectonic contact (i.e., the Filabres shear zone, a major detachment in the Betic Cordilleras, Spain). The density of C3' shear bands (or extensional crenulation cleavage) reworking the earlier S2 schistosity increases exponentially towards the contact, in parallel with the decrease in the size of the shear domains. Systematic variations in angles and shape ratios are also reported. Deformation and age patterns, however, suggest that this spectacular trend at least partly results from a progressive localization of the deformation through time. This fossilized shear strain gradient was thus produced somewhat diachronously. Such shear strain patterns nevertheless provide a mean to constrain the rheological properties for such weak lithologies and a mean to better understand crustal deformation.
ISSN: 0191-8141

insu-00545043
https://hal-insu.archives-ouvertes.fr/insu-00545043
https://hal-insu.archives-ouvertes.fr/insu-00545043/document
https://hal-insu.archives-ouvertes.fr/insu-00545043/file/JSGagardetal2.pdf
DOI : 10.1016/j.jsg.2010.11.011

Éditeur(s) : HAL CCSD
Résumé : National audience
se sont accrétés au cours du Mésozoïque. Ainsi, la collisionentre les blocs Indochine et Chine du Sud a engendré l’orogénèseIndosinienne. Durant la première moitié du XXè siècle, cet orogènea été défini et documenté à partir d’une discordance, dite Indosinienne,mise en évidence dans le Nord du Vietnam. Les études alorsréalisées ont permis d’estimer un âge antérieur au Jurassique inférieurpour cette discordance, qui n’a depuis pas fait l’objet deréévaluation. Outre la discordance Indosinienne, de nombreux débatsportent sur l’âge de la collision, la vergence de la subductionocéanique qui l’a précédée ou encore l’existence d’un véritable domaineocéanique ayant séparé l’Indochine de la Chine du Sud.Les bassins permo-triasiques du Nord du Vietnam (bassins deSam Nua et de Song Da), situés de part et d’autre de la sutureophiolitique de Song Ma, constituent, via le flux sédimentaireprovenant de l’érosion et du volcanisme des zones adjacentes, desarchives essentielles pour documenter l’évolution tectonique ducouple Indochine-Chine du Sud. A partir de données sédimentologiques,géochronologiques (datation U-Pb sur zircons) et biostratigraphiques(foraminifères), nous proposons une réévaluationdu cadre stratigraphique du Nord du Vietnam. Ces données nouspermettent d’envisager un âge postérieur au Trias moyen pour ladiscordance Indosinienne. A l’aide de données géochimiques et del’analyse du remplissage sédimentaire et volcanique des bassins,il est possible de documenter un volcanisme d’arc, actif au Triasinférieur. La position de cet arc par rapport aux limites des blocsIndochine et Chine du Sud, marquée par la suture ophiolitique deSong Ma, implique (i) une zone de subduction qui plongeait vers leSud (coordonnées actuelles), sous le bloc Indochine, en marge (ii)d’un véritable domaine océanique, et non pas d’une croûte continentaleamincie, séparant les deux blocs jusqu’au Trias moyen.Nos interprétations, issues de l’analyse des bassins sédimentairespermo-triasiques du Nord Vietnam, permettent également de reconstituerl’évolution de l’orogénèse Indosinienne. Celle-ci faitsuite à la subduction de la croûte océanique rattachée à une plaqueChine du Sud sous une plaque Indochine au Trias inférieur (etprobablement au moins depuis le Permien inférieur). A partir dela fin du Trias moyen, les blocs Indochine et Chine du Sud entrenten collision et forment l’orogène Indosinienne.
RST 2016, livre des résumés
Caen, France

insu-01388676
https://hal-insu.archives-ouvertes.fr/insu-01388676

Éditeur(s) : HAL CCSD Springer Verlag (Germany)
Résumé : International audience
Tight control of basal cytosolic Ca2+ concentration is essential for cell survival and to fine-tune Ca2+-dependent cell functions. A way to control this basal cytosolic Ca2+ concentration is to regulate membrane Ca2+ channels including store-operated Ca2+ channels and secondary messenger-operated channels linked to G-protein-coupled or tyrosine kinase receptor activation. Orai, with or without its reticular STIM partner and Transient Receptor Potential (TRP) proteins, were considered to be the main Ca2+ channels involved. It is well accepted that, in response to cell stimulation, opening of these Ca2+ channels contributes to Ca2+ entry and the transient increase in cytosolic Ca2+ concentration involved in intracellular signaling. However, in various experimental conditions, Ca2+ entry and/or Ca2+ currents can be recorded at rest, without application of any experimental stimulation. This led to the proposition that some plasma membrane Ca2+ channels are already open/activated in basal condition, contributing therefore to constitutive Ca2+ entry. This article focuses on direct and indirect observations supporting constitutive activity of channels belonging to the Orai and TRP families and on the mechanisms underlying their basal/constitutive activities.
ISSN: 0175-7571

inserm-01526286
http://www.hal.inserm.fr/inserm-01526286
http://www.hal.inserm.fr/inserm-01526286/document
http://www.hal.inserm.fr/inserm-01526286/file/EBJO-D-16-00056_R1-2%20%282%29.pdf
PUBMED : 28516266

Éditeur(s) : HAL CCSD
Résumé : High Pressure - Low Temperature (HP-LT) rocks testify for burying and exhumation of crustal material in subduction zones. Their complete exhumation is the result of processes acting during (syn-orogenic) and after (post-orogenic) subduction is active, the latter partly obliterating the first. In the Aegean domain, the Attic-Cycladic Blueschist unit (ACBU) is a HP-LT unit exhumed in metamorphic core complexes (MCCs) in the back-arc domain of the Hellenic subduction zone. This study is an attempt to distinguish features related to syn-orogenic exhumation processes responsible for the first stages of exhumation This syn-orogenic "message" has to be read through the post-convergence structural and thermal overprint that accompanied the formation of the MCCs. Particularly, the geometry, the timing and the amount of the syn-orogenic exhumation has to be determined. We investigate these features with coupled field, metamorphic petrology and radiochronology studies First, based on observations on Ios (southern Cyclades), it has recently been proposed that syn-orogenic exhumation of the ACBU was accommodated by a basal thrust over the Cycladic Basement (CB) [Huet, et al., 2009]. The peak conditions, deduced from pseudosections calculation for the Ios main lithologies, are 500 °C-19 kbar for the ACBU and 550 °C-16 kbar for the CB. Exhumation until 400 °C-8 kbar is considered as syn-orogenic. Second, phengites populations, single grains and in situ 40Ar-39Ar geochronology has been carried out on samples from Tinos and Andros (northern Cyclades), Syros (central Cyclades) and Ios. The results gather in several clusters: 50-55 Ma, 40-45 Ma, 30-35 Ma, and 22-26 Ma. Based on these new P-T-t data and a synthesis of published data, we are able to refine the geometry and the timing of the exhumation of the ACBU. Data from the whole Cyclades exhibit little differences in ages and P-T conditions for the successive stages of exhumation. The peak of pressure (500±50 °C-18±1 kbar) has been reached at 50-55 Ma from Tinos to Ios. The onset of the exhumation occurred at 40-45 Ma in blueschist facies conditions, between a thrust at their bottom and a detachment at their top. The following decompression was accompanied by cooling until 30-35 Ma (400±50 °C-8±1 kbar). At that time, the boundary conditions switched to extension. Finally, we propose a model for the exhumation of HP-LT units accounting for these data. We also consider the rheological implications of the syn-orogenic structuration of the Aegean wedge on the post-orogenic evolution. B. Huet, L. Labrousse, and L. Jolivet [2009] Thrust or detachment? Exhumation processes in the Aegean: Insight from a field study on Ios (Cyclades, Greece), Tectonics, 28, 3, doi:10.1029/2008TC002397.
EGU General Assembly
Vienne, Austria

insu-00839054
https://hal-insu.archives-ouvertes.fr/insu-00839054
BIBCODE : 2010EGUGA..1214098H

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
Phthalates are common atmospheric contaminantsused in the plastic industry. Ants have been shown to constitutegood bioindicators of phthalate pollution. Hence,phthalates remain trapped on ant cuticles which are mostlycoated with long-chain hydrocarbons. In this study, we artificiallycontaminated Lasius niger ants with four phthalates:dibutyl phthalate (DBP), diisobutyl phthalate (DiBP), di(2-ethylhexyl) phthalate (DEHP), and benzyl butyl phthalate(BBP). The first three have previously been found on ants innature in Touraine (France), while the fourth has not. The fourphthalates disappeared rapidly (less than 5 days) from thecuticles of live ants. In contrast, on the cuticles of dead ants,DEHP quantities remained unchanged over time. These resultsindicate that phthalates are actively absorbed by thecuticles of live ants. Cuticular absorption of phthalates isnonspecific because eicosane, a nonnatural hydrocarbon onL. niger cuticle, was similarly absorbed. Ants are importantecological engineers and may serve as bioindicators of ecosystemhealth. We also suggest that ants and more generallyterrestrial arthropods may contribute to the removal ofphthalates from the local environment
ISSN: 0944-1344

hal-01081622
https://hal.archives-ouvertes.fr/hal-01081622
https://hal.archives-ouvertes.fr/hal-01081622/document
https://hal.archives-ouvertes.fr/hal-01081622/file/Lenoir-et-al-ESPR2014-10.1007_s11356-014-3272-2.pdf
DOI : 10.1007/s11356-014-3272-2

Éditeur(s) : HAL CCSD Taylor & Francis edition
Résumé : International audience
ISSN: 2044-5911

hal-01633116
https://hal.archives-ouvertes.fr/hal-01633116
https://hal.archives-ouvertes.fr/hal-01633116/document
https://hal.archives-ouvertes.fr/hal-01633116/file/Manuscript%20robin%20et%20al.%20with%20author%20R3%20clean.pdf
DOI : 10.1080/20445911.2017.1384382

Éditeur(s) : HAL CCSD Cambridge University Press (CUP)
Résumé : International audience
This paper presents a synthetic view of the geodynamic evolution of the Zagros orogen within the frame of the Arabia-Eurasia collision. The Zagros orogen and the Iranian plateau preserve a record of the long-standing convergence history between Eurasia and Arabia across the Neo-Tethys, from subduction/obduction processes to present-day collision (from ~ 150 to 0 Ma). We herein combine the results obtained on several geodynamic issues, namely the location of the oceanic suture zone, the age of oceanic closure and collision, the magmatic and geochemical evolution of the Eurasian upper plate during convergence (as testified by the successive Sanandaj-Sirjan, Kermanshah and Urumieh-Dokhtar magmatic arcs), the P-T-t history of the few Zagros blueschists, the convergence characteristics across the Neo-Tethys (kinematic velocities, tomographic constraints, subduction zones and obduction processes), together with a survey of recent results gathered by others. We provide lithospheric-scale reconstructions of the Zagros orogen from ~ 150 to 0 Ma across two SW-NE transects. The evolution of the Zagros orogen is also compared to those of the nearby Turkish and Himalayan orogens. In our geotectonic scenario for the Zagros convergence, we outline three main periods/regimes: (1) the Mid to Late Cretaceous (115-85 Ma) corresponds to a distinctive period of perturbation of subduction processes and interplate mechanical coupling marked by blueschist exhumation and upper-plate fragmentation, (2) the Paleocene-Eocene (60-40 Ma) witnesses slab break-off, major shifts in arc magmatism and distributed extension within the upper plate, and (3) from the Oligocene onwards (~ 30-0 Ma), collision develops with a progressive SW migration of deformation and topographic build-up (Sanandaj-Sirjan Zone: 20-15 Ma, High Zagros: ~12-8 Ma; Simply Folded Belt: 5-0 Ma) and with partial slab tear at depths (~10 Ma to present). Our reconstructions underline the key role played by subduction throughout the whole convergence history. We finally stress that such a long-lasting subduction system with changing boundary conditions also makes the Zagros orogen an ideal natural laboratory for subduction processes.
ISSN: 0016-7568

insu-00616582
https://hal-insu.archives-ouvertes.fr/insu-00616582
https://hal-insu.archives-ouvertes.fr/insu-00616582/document
https://hal-insu.archives-ouvertes.fr/insu-00616582/file/692.full.pdf
DOI : 10.1017/S001675681100046X

Éditeur(s) : HAL CCSD
Résumé : International audience
The giant Imiter silver mine located at the northern edge of the West African craton in Morocco is assumed to be a late Neoproterozoic epithermal deposit mainly characterized by a hypogene paragenesis of Agrich sulphides and sulfosalts, and Ag-Hg alloys occuring preferentially in quartz-rich veins. The secondary enrichment zone at Imiter reaches a thickness of 50 to 150 m below ground surface. The upper levels, famous because of giant native silver crystals, grade up to 300 kg/t. Metallographic observations, SEM-EDS and XRD analyses reveal the presence of a quite complex secondary paragenesis made of acanthite, cinnabar, imiterite, perroudite, cerussite, mimetite, iron oxyhydroxides, synchisite and coronadite. Supergene alteration processes of the giant Imiter silver mine deposit consist of the remobilisation of the primary hypogene paragenesis by (i) deep and old basinal brines and (ii) downward infiltrations of surficial waters becoming progressively more reduced and F-enriched in response to fluid-rock interactions. Development of such a supergene mineralization strongly suggests prevalence of arid to semiarid conditions.
Let's talk ore deposits, proceeding of the eleventh biennial sga meeting
Antofagasta, Chile

hal-00601984
https://hal-brgm.archives-ouvertes.fr/hal-00601984
https://hal-brgm.archives-ouvertes.fr/hal-00601984/document
https://hal-brgm.archives-ouvertes.fr/hal-00601984/file/SGA2011_0234.pdf

Éditeur(s) : HAL CCSD European Respiratory Society
Résumé : International audience
Telomerase reverse transcriptase (TERT) or telomerase RNA (TERC) gene mutation is a major monogenic cause of pulmonary fibrosis. Sequencing of TERT/TERC genes is proposed to patients with familial pulmonary fibrosis. Little is known about the possible predictors of this mutation and its impact on prognosis. We retrospectively analysed all the genetic diagnoses made between 2007-2014 in patients with pulmonary fibrosis. We evaluated the prevalence of TERT/TERC disease-Associated variant (DAV), factors associated with a DAV, and the impact of the DAV on survival. 237 patients with pulmonary fibrosis (153 with familial pulmonary fibrosis, 84 with telomere syndrome features without familial pulmonary fibrosis) were tested for TERT/TERC DAV. DAV was diagnosed in 40 patients (16.8%), including five with non-idiopathic interstitial pneumonia. Prevalence of TERT/TERC DAV did not significantly differ between patients with familial pulmonary fibrosis or with only telomere syndrome features (18.2% versus 16.4%). Young age, red blood cell macrocytosis, and low platelet count were associated with the presence of DAV; the probability of DAV was increased for patients 40-60 years. Transplant-free survival was lower with than without TERT/TERC DAV (4.2 versus 7.2 years; p=0.046). TERT/TERC DAV were associated with specific clinical and biological features and reduced transplantfree survival. ©ERS 2016.
ISSN: 0903-1936

hal-01467555
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01467555
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01467555/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01467555/file/Prevalence%20and%20characteristics%20of%20TERT.pdf
DOI : 10.1183/13993003.02115-2015

Éditeur(s) : HAL CCSD
Résumé : Diffusion du document : INRA Antilles-Guyane, UMR ECOFOG, 97387 Kourou, Guyane (France)Diplôme : DESS
il s'agit d'un type de produit dont les métadonnées ne correspondent pas aux métadonnées attendues dans les autres types de produit : DISSERTATION
absent
https://hal.archives-ouvertes.fr/hal-01189286

hal-01189286
https://hal.archives-ouvertes.fr/hal-01189286
PRODINRA : 23332

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Crystal growth driven by a flowing solution is modeled for a flow with low Reynolds number using a computational dynamic software. Considering equivalent crystallographic faces, the chemical flux is calculated along upstream and downstream faces. Upstream flux is higher compared to downstream and leads to a symmetry breakdown of the crystal shape and develops mirror symmetry parallel to the flow velocity. Moreover the ratio of these two fluxes (upstream / downstream) gives a quantitative relation between the relative crystal growth rate and the flow velocity. Thus, using an inverse method, the flow direction and velocity can be deduced by the study of the variation of the growth band thicknesses of equivalent crystallographic faces. This new method was applied to the formation of metasomatic tourmalinite associated with a leucogranite sill. The approach is complemented by a study of the chemistry of the tourmaline. In the studied case, the application of the new method gives the high fluid velocities in pores (10-3 - 10-4 m/s) during metasomatism. Equivalent Darcy velocities are estimated and discussed accounting for the major role played by the regional deformation. Finally, a two-stage tectono-hydrodynamic model is proposed for the metsomatism. The first stage is genetically linked to the sill injection, and the second is characterized by a wider event with hydrothermal flow passing along the leucogranite sills.
ISSN: 0012-821X

Droits : info:eu-repo/semantics/OpenAccess
insu-00352307
https://hal-insu.archives-ouvertes.fr/insu-00352307
https://hal-insu.archives-ouvertes.fr/insu-00352307/document
https://hal-insu.archives-ouvertes.fr/insu-00352307/file/Sizaret_et_al_final.pdf
DOI : 10.1016/j.epsl.2009.01.013

Éditeur(s) : HAL CCSD ACS American Chemical Society - Publications
Résumé : International audience
ABSTRACT: In this paper, the structural, optical and thermal properties of n-type (100),p-type (100) and (111) mesoporous silicon (MePSi) are reported. The mesoporous silicon wasprepared by an electrochemical process from bulk silicon wafer. Depending on the etchingdepth, analyses show that the porosity of p-type (111) increased by 32 to 40% compared to p(100) which, in turn, increased by 22 to 48% compared to n-type (100). The structuremorphology and the abundance of Si-Ox and Si-Hy also depended heavily on the type andcrystal orientation of MePSi. The thermal properties of the MePSi layers such as thermalconductivity (κ), volumetric heat capacity (ρCp) and thermal contact resistance (Rth) weredetermined using the pulsed photothermal method. The thermal conductivity of bulk silicondropped sharply after etching, decreasing by more than twenty-fold in the case of n-type (100)and by over forty-five fold for p-type (100) and (111). According to the percolation modeldepending on both porosity and phonon confinement, the drop in thermal conductivity wasmainly due to the nanostructure formation after etching. Thermal investigations showed thatthe volumetric heat capacity (ρCp) followed the barycentric model which depends mainly onthe porosity. The thermal contact resistances of MePSi layers were estimated to be in therange of 1x10-8 to 1x10-7 K⋅m2⋅W-1.
The Journal of Physical Chemistry C

hal-01495490
https://hal.archives-ouvertes.fr/hal-01495490
DOI : 10.1021/acs.jpcc.6b13101

Éditeur(s) : HAL CCSD
Résumé : International audience
11ème Congrès international de l'ACAPS
Paris, France

hal-01633112
https://hal.archives-ouvertes.fr/hal-01633112
https://hal.archives-ouvertes.fr/hal-01633112/document
https://hal.archives-ouvertes.fr/hal-01633112/file/acaps%202005%20com%20orale.pdf