1,015 results on '"Chrome"'
Search Results
1002. Étude critique des réactifs des cations. 12, Réactifs des cations et des anions du chrome
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Roger Duckert, Yvonne Rusconi, and Paul Eugène Etienne Wenger
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Inorganic Chemistry ,Analyse qualitative (chimie) ,Chemistry ,Organic Chemistry ,Drug Discovery ,ddc:540 ,Chrome ,Physical and Theoretical Chemistry ,Biochemistry ,Medicinal chemistry ,Réactifs chimiques ,Catalysis - Published
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1003. Étude de l'absorption des phosphates, azote, chrome et cadmium par trois algues vertes isolées à partir d'effluents urbains
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R. A. Zerhouni, C. Ronneau, J. Cara, and D. Bouya
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azote ,Social Sciences and Humanities ,Algae ,cadmium ,nitrogen ,Algues ,chrome ,Sciences Humaines et Sociales ,chromium ,ahosphates ,eaux usées ,absorption ,wastewater ,Water Science and Technology ,biosorption ,phosphate - Abstract
La capacité de déphosphatation et de dénitrification ainsi que la sensibilité et l'accumulation de deux métaux lourds (Cr et Cd) de Scenedesmus quadricauda, Chlorella pyrenoidosa et Chlamydomonas reinhardtii isolées des eaux usées de la ville de Fès, ont été étudiées dans les conditions de laboratoire. Les résultats ont montré que S. quadricauda présente les meilleurs taux de réduction des phosphates (83%), et d'ammonium (75%). L'étude de la sensibilité vis à vis du chrome et du cadmium des trois espèces, a montré qu'au delà d'une concentration de 1 ppm, la croissance se trouve réduite et que S. quadricauda présente une sensibilité plus faible que les deux autres espèces. Les résultats des expériences d'absorption conduites avec du chrome VI marqué au51 Cr et du cadmium marqué au109 Cd ont montré que les quantités de chrome et du cadmium prélevées par S. quadricauda dépassent celles des deux autres espèces. L'utilisation potentielle des trois espèces dans le traitement des effluents urbains est discutée à la lumière des résultats de ces expériences., Wastewater discharge is an environmental problem, especially in developing countries. Biological wastewater treatment seems to be an alternative for these countries due to its low cost. Algae are used in such wastewater treatment systems in many parts of the world. In addition to preventing environmental damage, the reuse of treated wastewater can be an alternative water supply in arid regions and during drought periods.In this paper, three algal (Chlamydomonas reinhardtii, Chlorella pyrenoïdosa and Scenedesmus quadricauda) species were isolated from an urban effluent collected from a Mediterranean city (Fez, Morocco, situated between 4° to 7° W and 33° to 35° N) and their ability to remove phosphate and nitrogen was tested under laboratory conditions. The toxicity and uptake of chromium and cadmium were also studied.Fez city wastewater was sampled monthly during one year (2000) at three main stations located along the Boukhrareb stream which crosses the city. The following parameters were measured according to methods described by RODIER J. (1996): Chemical oxygen demand, COD; Biological oxygen demand, BOD; NO3 -; NH4 +; PO43 -; electrical conductivity (EC) and organic matter. Heavy metals (Cr, Fe and Zn) were measured by INAA (Instrumental Thermal Neutron Activation Analysis) in wastewater samples dried on Teflon sheets at 70°C.The collected samples were incubated under controlled conditions and species of alga were identified, isolated, and then transferred to fresh culture medium. Chlamydomonas reinhardtii, Chlorella pyrenoïdosa and Scenedesmus quadricauda were chosen for these experiments because of their abundance in wastewater over the year and for their capacities for biomass production. The removal of nutrients from aqueous media was studied by using monospecific cultures. Algae were in the exponential growth phase when the experiments were started and BG11 culture medium was used under standard growth conditions. Initial concentrations of phosphate and nitrogen were 2.24 mg×L-1 (PO43 -), 12.84 mg×L-1 (NO3 -) and 0.26 mg×L-1 (N-NH4 +). The concentrations decreased during the experimental period, and degrees of removal ranged from 83 to 75% for phosphate, from 85 to 77% for nitrogen and from 52 to 75% for ammonium.To evaluate the sensitivity of the algal cells to heavy metals, the algal strains were exposed for one week to chromium as K2Cr2O7 and cadmium as CdCl2 at concentrations of 0.1, 0.5, 1, 1.5 and 2 ppm (mg×L-1) of Cr or Cd. Culture growth was monitored by microscopic counting of algal cells to determine quantitative biomass changes. Results demonstrated that growth inhibition occurred at 1 ppm Cr and Cd, whereas levels of 1.5 and 2 ppm of both metals were lethal to the cultures, but no effect on growth was seen in algae exposed to 0.1 ppm of Cd or 0.1 ppm of Cr. Scenedesmus quadricauda was more resistant than Chlamydomonas reinhardtii and Chlorella pyrenoïdosa to chromium and cadmium.Radiotracers (51Cr and 109Cd) were used to trace the biosorption of chromium and cadmium by the three algal strains. Cr(VI) as K2 Cr2O7 and Cd as CdCl2 were added to the algal suspension culture to give concentrations of 1, 1.5 and 2 ppm Cd and Cr respectively. At various stages during growth of the unialgal cultures, samples were removed, a pulse of51 Cr or109 Cd was added, and the uptake rates of Cr(VI) and Cd were determined. To evaluate the amount of heavy metals removed by the algal cells, microscopic cell counting was carried out. All the experiments were conducted under the above-mentioned conditions for each concentration studied, the measurements were repeated three times and the mean values from the three replicates were calculated. The results showed that chromium and cadmium removal by algae was dependent on the metal concentration in the culture medium. The quantity of metal removed also varied with algal species, where 20 µg, 23 µg and 35 µg of Cd were accumulated by 106 cells of Chlorella, Chlamydomonas and Scenedesmus respectively at a metal concentration of 2 ppm. About 25 µg of Cr were accumulated by 106 cells of Chlorella and Chlamydomonas whereas, 106 cells of Scenedesmus accumulated 32 µg of Cr at a concentration of 2 ppm.The experimental data presented here demonstrated that there was not a great difference in the uptake capabilities between the three algal strains, and reaffirmed the potential of algae in the purification of metal-contaminated wastewater. This wastewater treatment system has many advantages and it is an efficient way to significantly reduce the release of nutrients (e.g., phosphorus, nitrogen, ammonia) and heavy metals (e.g., chromium and cadmium). more...
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1004. Nouvelle technique pour l'amélioration et la conservation des sols : rémédiation in situ de métaux trace dans les sols contaminés
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NEGIM, Osama, Le Coustumer, Philippe, Mench, Michel, Marigomez, Ionan, Gauthier, Arnaud, Huneau, Frédéric, Fouad, Amin, Fabre, Richard, Motelica-Heino, Mikael, and Lespes, Gaëtane
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Scories ,Cuivre ,Chrome ,Rémédiation ,CCA ,Re-végétalisation ,Arsenic
1005. Enlèvement du chrome par infiltration verticale sur lits de Phragmites australis (Cav.) Steudel
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Abderrahim Jaouad, Laila Mandi, and S. Tiglyene
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Social Sciences and Humanities ,Phragmites australis (Cav.) Steudel ,climat aride ,arid climate ,industrial wastewater ,chrome ,tannerie ,Sciences Humaines et Sociales ,reed beds ,chromium ,tannery ,rejet industriel ,Water Science and Technology ,lits à roseaux - Abstract
L'objectif de la présente étude est de mettre en évidence les potentialités d'un hélophyte : Phragmites australis (Cav.) Steudel à épurer l'effluent du tannage riche en chrome sous un régime d'écoulement vertical et les comparer à celles d'un sol non planté sous climat aride.Le pilote expérimental est constitué de pots de capacité 120 litres, remplis sur une épaisseur de 15 cm de graviers et de 60 cm de sol (texture : limono - argilo- sableuse). Trois pots sont plantés de jeunes tiges de Phragmites australis (36 tiges /m2). Trois autres pots non plantés sont pris comme témoin. L'alimentation du système se fait par l'eau du tannage au chrome diluée à 50%. L’alimentation des systèmes se fait par bâchées de 10 litres/jour pendant 3 jours successifs suivie d’une période de repos de 4 jours. L'écoulement se fait par translation verticale à travers le substrat.L'étude du fonctionnement hydrologique des pilotes testés a montré que le débit moyen à la sortie du système planté est trois fois plus élevé que celui du lit non planté, ce qui permet de traiter un volume d’eau usée plus important ou bien de réduire la superficie nécessaire par équivalent habitant. Aucun signe de colmatage n’a été détecté aussi bien dans les pots plantés de Phragmites australis que dans les pots non plantés.Le suivi des performances épuratoires du système à Phragmites australis montre que le pH à la sortie des deux systèmes pilotes augmente de deux à trois unités par rapport à celui des rejets du tannage. La conductivité électrique des effluents traités augmente respectivement pour les deux systèmes.L’élimination moyenne de la DCO totale est de 74% pour le système planté et de 60,5% pour le système non planté. La différence entre les performances épuratoires des deux systèmes pour l’abattement de la DCO totale est statistiquement significative (p, The aim of this study was to investigate the potential of a helophytic plant, Phragmites australis (Cav.) Steudel, to remove chromium from concentrated tannery effluent in comparison to unplanted soil, under arid climate conditions. The experiment was conducted from August 2002 to August 2003. Six plots (capacity: 120 L, diameter: 50 cm) were filled to depths of 15 cm and 60 cm with gravel and soil respectively (texture: 3.5% clay, 8.5% silt, and 88% sand). Three plots were planted with Phragmites australis (Cav.) Steudel. Young shoots of plants (36 stems/m2) were taken from local and natural reed stands. Three unplanted plots were used as controls. The soil for the study was from the Tensift River (Marrakech). The experimental plots were supplied exclusively with diluted tannery wastewater, 3 times a week (approximately 10 L each time). The water flowed vertically through the substratum.To investigate the capacity of the systems to increase pH, to decrease conductivity chemical oxygen demand (COD), and to remove total chromium, concentrations in the inflow and outflow of each plot were determined during the experiment. System hydrology indicated that for planted systems, the mean flow varied from 18 mL/min (in winter) to 49 mL/min (in summer), with an average value of 35 mL/min. For the unplanted system, the mean flow varied from 5 mL/min (in winter) to 15 mL/min (in summer) with an average value of 12 mL/min. Water recovery at the outflow of the planted system (PP) and unplanted system (NPP) was 40% and 60% respectively. This may be related to the phenomenon of evapotranspiration from the PP system, which was more significant than simple evaporation from the NPP system. No sign of clogging was observed in the planted systems due to the plant rhizomes that ensure a better aeration of the soil. The study of the hydrological operation showed that mean flow in the planted system was three times higher than that in the unplanted soil, which makes it possible to treat a larger volume of wastewater and to reduce the required per capita surface for treatment. The presence of Phragmites australis ensured a sufficient porosity for the percolation of water for treatment.The pH of the effluent at the outlets of the planted and unplanted systems increased by two to three units in comparison with the raw wastewater at the inlet. The average inflow pH was 5.5; at the outflow of the two systems, the pH was 7.30 and 8.20 respectively for the planted and unplanted soil. The electrical conductivity (EC) of the treated wastewater increased for the two systems. The average inflow conductivity was 54±5.5ms/cm. At the outflow of the two systems, the EC was about 75±14 ms/cm and 68±11 ms/cm respectively for the planted and unplanted systems. The EC removal for all systems varied significantly from season to another (p< 0.05).The planted system was more efficient in removing total COD (74%) than the unplanted one (61%). There were significant differences (ANOVA) between the PP and NPP systems (p more...
1006. Impact écotoxicologique du traitement chimique des eaux usées de tanneries: Analyse technico-économique
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A. Nejmeddine and A. Yatribi
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Social Sciences and Humanities ,chemical treatment ,toxicity ,test Daphnie ,analyse financière ,test daphnia ,reuse ,financial analysis ,Tannery ,réutilisation ,chrome ,toxicité ,Sciences Humaines et Sociales ,chromium ,Tannerie ,traitement chimique ,Water Science and Technology - Abstract
La toxicité des eaux usées du tannage au chrome et d'épilage-pelanage, avant et après traitement, a été évaluée par test Daphnia pulex. Cette évaluation a été déterminée à partir des équations de corrélation linéaires. Les résultats obtenus montrent que le tannage au chrome et l'épilage-pelanage présentent une toxicité élevée avec des valeurs des CI50 24h respectives de 0,15 et 3,36. Cette toxicité élevée pourrait être expliquée par la charge de ces effluents en chrome, en sulfures et en matière organique.Après traitement par précipitation chimique, la CI50 24h a connu une importante augmentation. Elle est passée de 0,15 à 26,58 et de 3,36 à 11,1 respectivement pour le tannage au chrome et l'épilage-pelanage. Par conséquent, ces effluents traités peuvent être classés comme rejets peu toxiques. Cette diminution de la toxicité est liée surtout à l'abattement des MES (95 %), de la DCO (55 %), de Cr (90 %) et des sulfures (50 %). Ce traitement a donc, un double intérêt; le premier est environnemental, le second est économique du fait de la possibilité de recyclage du chrome récupéré dans le tannage du cuir. En effet, l'application expérimentale du chrome dans le tannage a montré un résultat similaire à celui obtenu par le produit commercial. Ainsi, suite à une analyse technico-économique, le bénéfice réalisé par cette opération est estimé à 3112,50 $ par 1000 tonnes par an., The purpose of our investigation was to evaluate the acute toxicity of chromium tanning and liming-deliming waste waters before and after chemical treatment. The invertebrate Daphnia pulex was used for toxicity test. The toxicity due to these industrial waste waters was revealed by the equations of the regression lines. The results of the toxicity test showed that the waste waters from chromium tanning and from dehairing presented higher toxicity, with respective 24-h IC50 values of 0.15 and 3.36. This toxicity could be explained by higher levels of chromium, sulphides and organic matter in these waste waters.After processing by chemical precipitation, 24-h IC50 values increased from 0.15 to 26.6 and from 3.4 to 11.1 respectively for the chromium tanning and the de-hairing waste waters. Consequently, these processed effluents can be classified as low toxic wastes. This diminution of the toxicity is linked to a reduction of suspended matter (95 %), COD (55 %), Cr (90 %) and sulphides (50 %). Hence, this treatment presents at least two advantages. The first is environmental, as just mentioned; the second is economic, since chromium can be recycled for reuse in leather tanning. The results suggest that the recovered chromium is similar to commercial tanning chromium. In fact, a techno-economical analysis showed that proposed treatment project can be economically beneficial (3112,50 $ per 1000 tons per year). more...
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1007. Diseño de plataformas de estado sólido para la determinación simultánea de cromo III y VI [Design of solid-state platforms for the simultaneous determination of Cr III and VI]
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Miscoria, Silvia Alejandra, Jacq, Caroline, Blengini, Andrea, Maeder, Thomas, and Negri, R. Martín
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ionophore ,couches épaisses ,graphite ,carbon ,electrochemical sensors ,SPEs ,cuprizone ,screen-printed electrodes ,chrome ,capteurs électrochimiques ,PVB ,carbone ,chromium ,thick-film technology ,électrodes sérigraphiées - Abstract
Speciation analyses of an element allow obtaining information on the concentrations of its chemical forms present in specific environments. Chromium is largely distributed in industrial effluents often at acid pH, with the relevant oxidation states Cr (III) and Cr (VI) having contrasting impacts on the environment and health. While trivalent chromium is relatively harmelss and is an essential trace element, the hexavalent form is highly toxic. Therefore, it is important to know which species is stable, and pollution monitoring requires robust sensors that tolerate very acid pH levels. We investigate carbon-based screen-printed electrodes (SPEs), which are practical, disposable and low-cost devices and are easy to tailor to specific uses. Here, we add a specific ionophore, cuprizone, i.e. (cyclohexanone)oxaldihydrazone by electrodeposition to an electrode consisting of graphite bound with polyvinylbutyral (PVB). This matrix exhibits sufficient resistance to the acid working conditions. The combination of the analytical yield and the enormous possibilities of SPEs open the door to new sensor designs meeting the current needs of environmental and pharmacological chemical analysis. more...
1008. Screen-printed electrochemical chromium (VI) sensing electrodes for effluent bioremediation monitoring
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Miscoria, Silvia Alejandra, Jacq, Caroline, Maeder, Thomas, and Negri, R. Martín
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ionophore ,couches épaisses ,analysis ,analyse ,chemical sensors ,screen-printed electroes ,capteurs chimiques ,chrome ,DTPA ,électrodes spécifiques ,specific electrodes ,chromium ,SPE ,thick-film technology ,électrodes sérigraphiées - Abstract
Simple, low-cost and acid-resistant carbon-based screen-printed electrodes (SPEs) addressed to detection of hexavalent chromium species, Cr(VI), in sulfuric acid at pH about 1, were prepared and characterized. Working and counter electrodes were prepared jointly on the same substrate in a single strip (working-counter electrodes pair). The batch printing process allowed obtaining many working-counter electrode pairs in a unique step. The developed working electrodes are comprised of several layers deposited on an alumina substrate: (1) bottom silver conductor, (2) dense organic-graphite composite conductor, (3) active layer consisting of a porous organic-graphite composite which contains a Cr(III) ionophore for testing Cr(III) obtained after reducing Cr(VI), and (4) an insulating and protective dielectric. All materials except the bottom Ag conductor were made on an organic matrix based on a thermoplastic polymer, polyvinylbutyral (PVB). The amperometric determination of Cr(VI) species at pH 1 was performed over a wide concentration range (dynamic range 3 µM - 40 mM). The range for linear amperometric response is 3 µM – 10 mM, with sensitivity about 0.08 mA/mM. The sensitivity is improved in comparison with previously developed sensors, while keeping a low limit of detection (LOD about 1µM). The response of the sensors are not interfered by the presence of Cr(III) in the solution, although the sensor can detect local formation of Cr(III) at the electrode surface after the reduction of Cr(VI) when diethylenetriamine-pentaacetic acid (DTPA), a complexing agent for Cr(III) is incorporated into the pastes. more...
1009. Dispersion et exposition humaine aux métaux en Nouvelle-Calédonie : synthèse des résultats
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Magalie Baudrimont, Yannick Dominique, Agnès Feurtet-Mazel, Patrice Gonzalez, Pierre-Yves Gourvès, Peggy Gunkel-Grillon, Laporte-Magoni Christine, Estelle Lefrançois, Yves Letourneur, Julien Marquié, Régine Maury-Brachet, Fabrice Monna, Camille Pasquet, Emmanuel Rivière, Estelle Roth, Jean-Paul Ambrosi, Tom Biscéré, Aurélie Boula, Cécile Dupouy, Jean-Michel Fernandez, Fanny Houlbrèque, Maya Ikogou, Farid Juillot, Pauline Merrot, Cyrille Métayer, Mickaël Meyer, Benjamin Moreton, Guillaume Morin, Georges Ona-Nguéma, Olivier Radakovitch, Nazha Selmaoui-Folcher, Éric Viollier, Guillaume Wattelez, Sylvaine Cordier, Yann Barguil, Audray St-Jean, Stéphane Mengant, Barbara Le Bot, Pierre Ayotte, Environnements et Paléoenvironnements OCéaniques (EPOC), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Bioeko [Nouméa, Nouvelle-Calédonie], UMR 5805 Environnements et Paléoenvironnements Océaniques et Continentaux (EPOC), Centre National de la Recherche Scientifique (CNRS), Institut de sciences exactes et appliquées (ISEA), Université de la Nouvelle-Calédonie (UNC), Asconit Consultants, Archéologie, Terre, Histoire, Sociétés [Dijon] (ARTeHiS), Ministère de la Culture et de la Communication (MCC)-Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences Exactes et Appliquées, Université Polytechnique Nazi Boni Bobo-Dioulasso (UNB), Groupe de spectrométrie moléculaire et atmosphérique (GSMA), Université de Reims Champagne-Ardenne (URCA)-Centre National de la Recherche Scientifique (CNRS), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Sorbonne Université (SU), Ecologie marine tropicale des océans Pacifique et Indien (ENTROPIE [Nouvelle-Calédonie]), Ifremer - Nouvelle-Calédonie, Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut de Recherche pour le Développement (IRD [Nouvelle-Calédonie])-Université de la Nouvelle-Calédonie (UNC), Institut méditerranéen d'océanologie (MIO), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD [Nouvelle-Calédonie]), AEL/LEA, Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD), Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Institut National de la Santé et de la Recherche Médicale (INSERM), Centre hospitalier territorial Gaston-Bourret [Nouméa], Centre de recherche du CHU de Québec-Université Laval (CRCHUQ), CHU de Québec–Université Laval, Université Laval [Québec] (ULaval)-Université Laval [Québec] (ULaval), CNRT Nickel et son environnement, Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École Pratique des Hautes Études (EPHE), Aix Marseille Université (AMU), Institut de Recherche pour le Développement (IRD [Nouvelle-Calédonie])-Ifremer - Nouvelle-Calédonie, Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de la Nouvelle-Calédonie (UNC), Institut de Physique du Globe de Paris (IPGP (UMR_7154)), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE), and LAURENCE, BARILLER more...
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Manganèse ,Eléments traces métalliques ,[SDV.EE.SANT]Life Sciences [q-bio]/Ecology, environment/Health ,Dynamique des métaux ,Lagon ,Rivière ,Cobalt ,Nouvelle-Calédonie ,[SDE.BE] Environmental Sciences/Biodiversity and Ecology ,Contamination métallique ,Métaux ,Nickel ,Bassin versant ,[SDV.EE.SANT] Life Sciences [q-bio]/Ecology, environment/Health ,Chrome ,[SDE.BE]Environmental Sciences/Biodiversity and Ecology ,Activité minière - Abstract
Cette synthèse constitue le volume 4 (sur 4) du programme intégré « Dispersion et exposition humaine aux métaux en Nouvelle-Calédonie » composé de 3 programmes complémentaires étudiant les métaux et leur toxicité : DMML « Dispersion des métaux de la mine au lagon », Dynamine « Dynamique des métaux de la mine au lagon », Métexpo « Niveaux d’imprégnation et déterminants de l’exposition humaine aux métaux ».- Elle regroupe les synthèses de chacun des trois programmes et propose une conclusion commune ouvrant sur les perspectives en termes de recherche. more...
1010. MOX dopé chrome : optimisation du dopage et de l’atmosphère de frittage
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THOMAS, Régis, Jean-Marc Heintz, Mario Maglione [Président], Michèle Pijolat [Rapporteur], Alexandre Maître [Rapporteur], Jacques Léchelle, Laurence Brunel, Philippe Martin, Jean-François Silvain, Régis Castelli, Jean-Jérome Vermoyal, Heintz, Jean-Marc, Lechelle, Jacques, Brunel, Laurence, Martin, Philippe, Silvain, Jean-François, Castelli, Régis, Vermoyal, Jean-Jérome, Maglione, Mario, Pijolat, Michèle, and Maître, Alexandre more...
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Dopage ,Homogénéisation ,Solubilité ,Oxyde mixte ,Taille de grains ,Chrome ,Mox ,Spéciation ,Thermodynamique ,Atmosphère de frittage ,Plutonium
1011. KINETICS OF CHROMIUM EVAPORATION FROM HEAT-RESISTING STEEL UNDER REDUCED PRESSURE
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Cezary Kolmasiak
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lcsh:TN1-997 ,pressure ,chrome ,steel ,lcsh:Mining engineering. Metallurgy ,evaporation - Abstract
This paper describes a kinetic analysis of the process of chromium evaporation from ferrous alloys smelted under reduced pressure. The study discussed comprised determination of the liquid phase mass transfer coefficient as well as the value of the constant evaporation rate. By applying these values as well as the values of the overall mass transfer coefficient estimated based on the relevant experimental data, the fractions of resistance of the individual process stages were established. more...
1012. Ahead of the game: minerals in sports.
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Hughes, Emma
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INDUSTRIAL minerals ,INDUSTRIAL minerals industry ,MINERALOGY ,MINES & mineral resources ,FIFA World Cup ,COMMONWEALTH Games - Abstract
The most recent sport events, including FIFA World's Cup 2014 and the Commonwealth Games, show once again the importance of sport as a growing market for industrial minerals, which can offer new opportunities to industrial minerals suppliers worldwide. [ABSTRACT FROM AUTHOR] more...
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- 2014
1013. Chromium behavior in aquatic environments : a review
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Gorny, Josselin, Billon, Gabriel, Noiriel, Catherine, Dumoulin, David, Lesven, Ludovic, and Madé, Benoît
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- 2016
1014. Chemistry of chromium in lakes
- Published
- 1993
1015. Land application of sewage sludge: scientific perspectives of heavy metal loading limits in Europe and the United States
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- 1994
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