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1
Moriizumi, Jun, Takehisa Ohkuraa, Shigekazu Hirao, Yuki Nono, Hiromi Yamazawa, Yoon-Shin Kim, Qiuju Guo, Hitoshi Mukai, Yasunori Tohjima, and Takao Iida. "Continuous Atmospheric Radon-222 Concentration Observation in East Asia." American Institite of Physics, 2008. http://hdl.handle.net/2237/12040.
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Je, Imshun. "Soil-gas radon-222 anomalies in south central Ontario, Canada." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq29252.pdf.
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Richon, Patrick. "Le radon-222 traceur de la dynamique des systèmes géologiques : Méthodologie et traitement du signal, interprétation du comportement du radon-222 en milieux géologiques actifs." Paris, Institut de physique du globe, 2011. http://www.theses.fr/2011GLOB0003.
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Petraki, Ermioni. "Electromagnetic radiation and Radon-222 gas emissions as precursors of seismic activity." Thesis, Brunel University, 2016. http://bura.brunel.ac.uk/handle/2438/12872.
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Earthquakes are amongst the most destructive of natural phenomena and have been the subject of significant research effort over many decades, to predict the onset of seismic events. Electromagnetic emissions detected prior to earthquakes provide a potential data source for seismic predictions and research suggests that specific pre-seismic electromagnetic activity can be directly related to specific earthquakes although it is still an open issue as to the precise links between these electromagnetic emissions and subsequent earthquakes. In this research, findings of the long memory or the self-organization of several pre-earthquake MHz electromagnetic time-series provide significant outcomes regarding the earthquake prediction. It is also recognised that enhanced radon gas emission has an equally long history as being associated with seismic activity. In general, several anomalous soil radon emissions have been observed prior to earthquakes and this has been recorded all over the world. The abnormal soil radon exhalation from the interior of the earth has been associated with earthquakes and is considered as an important field of research. The research reported in this thesis compared and contrasted the merits of combining electromagnetic emission data and radon exhalation data as precursors of earthquakes with the aim of enhancing earthquake prediction methodology. The findings from the long-memory analysis of radon disturbances in the soil indicated a very significant issue: the radon disturbances in the soil prior to earthquakes exhibit similar behaviour as the MHz RF disturbances of general failure. So, the radon precursors and the MHz electromagnetic correspond to the same pre-earthquake phase. Geological explanations were proposed in view of the asperity model. Persistent and anti-persistent MHz anomalies were due to the micro-cracking of the heterogeneous medium of the earth's crust which may have led the system's evolution towards the global failure. Fractal methods have been used on historical data, to investigate MHz electromagnetic time-series spectra on emissions preceding major earthquakes over the period 2007 to 2014 and the characteristics of enhanced radon emissions have been studied over the period 2008 to 2015 for seismic events occurring in the Aegean Region. It has been found that both the electromagnetic emissions and the radon exhalation data exhibit similar fractal behaviour and are associated with impending seismic activity. Hence both phenomena are relevant to earthquake predictions and should both be employed in any systematic approach to this problem as the varying geological and geographic conditions under which earthquakes can occur, might preclude one or other data from being measurable. According to the several techniques applied in this thesis, all should be employed in sequential steps, albeit the power-law spectral fractal analysis is the most significant to trace long-memory patterns of 1/f processes as those of the processes of earthquakes.
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David, Anne. "Influence des paramètres hydroclimatologiques sur les déplacements verticaux du radon-222 en zone non-saturée /." Orléans : Éd. BRGM, 1995. http://catalogue.bnf.fr/ark:/12148/cb35843816k.
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Puck, Brent D. "Transport mechanisms for radon-222 in soils : a case study for Delaware County." Virtual Press, 1993. http://liblink.bsu.edu/uhtbin/catkey/879853.
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Radon transport mechanisms in soils were studied to determine the dominant transport mechanism for Delaware county soils. In modeling the soil, it was assumed that is was homogenous and moisture-free. Two transport mechanisms were investigated, the transport of radon in the soil by molecular diffusion (assumed to be governed by Fick's law) and transport by pressure-induced flow or convection (assumed to be governed by Darcy's law). Following the previous work of W. E. Clements, a general transport equation was described which incorporated both diffusion and convection. In steady-state conditions, a closed-form solution was obtained for the concentration of radon in the soil interstices as a function of depth. Similarly, solutions were examined for transport by diffusion alone. Representative soil parameters were assigned and the diffusion fraction (the ratio of concentration due to diffusion to the concentration due to both diffusion and convection) was calculated. Referring to the work of A. B. Tanner, a radon availability number (RAN) was determined for the soils; the RAN value was a measure of the activity of radon per unit area. Analyses were also performed to determine the significance of pressure variations on calculated diffusion fractions and RAN values. For 99% of the acreage in Delaware county, the diffusion fraction was 0.95 or greater. Therefore, it was concluded that molecular diffusion is the dominant transport mechanism for the soils of Delaware county.Department of Physics and Astronomy
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Pereyra, Anaya Patrizia Edel. "Mediciones de la concentración de Radon 222 en ambientes interiores en Lima-Perú." Master's thesis, Pontificia Universidad Católica del Perú, 2015. http://tesis.pucp.edu.pe/repositorio/handle/123456789/6724.
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Se realizó la medición de los niveles de Radón 222 en las estaciones de otoño y primavera del 2014 en residencias correspondientes a 30 distritos de Lima Metropolitana, incluyendo a las zonas Norte, Centro y Sur de la ciudad. Las casas en donde se realizaron las mediciones fueron seleccionadas considerando diversas variables como antigüedad, materiales de construcción, revestimientos, tipo de suelo, uso de las habitaciones monitoreadas, etc. Para las mediciones de Radón 222 se utilizaron detectores pasivos (Detectores de Estado Sólido de Huellas Nucleares) de nitrato de celulosa (LR – 115). En el trabajo se muestra el procedimiento de toma de datos, lectura de los dosímetros y los resultados de la medición, que es la primera que se realiza en esta ciudad. Los resultados solo indican la presencia de Rn 222, los detectores empleados no permiten discriminar la presencia de los descendientes del Radón 222.Tesis
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SYAHRIR, SYAHRIR. "TRANSPORT OF RADON IN STILL WATER." University of Cincinnati / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1109117669.
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Gibbons, Deirdre. "Modelling radon-222 as a proxy for vapour phase transport in the unsaturated zone." Thesis, Queen's University Belfast, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.322734.
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Schmidt, Axel. "Radon as a natural geochemical tracer for study of groundwater discharge into lakes /." Leipzig : UFZ, 2008. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=016691265&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
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David, Anne. "Influence des paramètres hydroclimatologiques sur les déplacements verticaux du radon-222 en zone non-saturée." Paris 6, 1992. http://www.theses.fr/1992PA066109.
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La prospection des anomalies de radon-222 dans les gaz du sol a pour but de recherche les sites favorables a l'implantation de forage d'eau en milieu fissure. L'etude classique de la variabilite spatiale du gaz est maintenant consideree comme insuffisante, au regard des fluctuations temporelles non negligeables mises en evidence dans la litterature et au cours de nos investigations: il s'avere que certaines perturbations atmospheriques influencent sensiblement l'equilibre de la masse gazeuse du sol. Un suivi des concentrations rn dans les gaz du sol a ete entrepris pendant un mois sur une parcelle experimentale de 1818 m, en vingt points prospectes chacun a 15, 30, 55 et 115 cm de profondeur. Les resultats montrent l'existence notable de fluctuations diurnes (20-30%) et journalieres (40%) a la profondeur standard (55 cm) d'echantillonnage, correlees principalement au gradient de pression atmospherique. Un modele numerique monodimensionnel a ete developpe aux differences finies pour simuler en transitoire le role effectif de la pression barometrique sur les concentrations rn d'un milieu poreux materialisant la zone non-saturee. Des processus dynamiques simples, consistant a engendrer des vitesses de darcy a partir des variations de pression atmospherique, et a les integrer sous le terme advectif dans l'equation classique du transport du radon, ont ete appliques au milieu. En supposant que le radon se deplace avec l'air dans le milieu poreux, il convient de considerer deux porosites differentes pour que le callage des donnees experimentales soit concluant; en d'autres termes, le radon semble profiter, sur notre site, d'une porosite nettement plus faible que l'air lors de son deplacement. Le modele a ete utilise pour apporter les corrections temporelles aux concentrations rn mesurees lors d'une prospection
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Wiking, Viktoria. "A study of naturally occurring radon in Swedish water purification plants." Thesis, KTH, Mark- och vattenteknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-199216.
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Radon dissolved in drinking-water can be transferred into the indoor air and is one of the main transfer pathways for radon. At water purification plants, large quantities of water are treated and there is a risk that radon degasses from the water and enters into the indoor air. Hence, there is a risk for elevated radon levels in the indoor air at these facilities. This study aims to investigate the general impact of water treatment processes on the radon concentration in water and its transfer into the indoor air. Moreover, the risk that radon exposure exceeds the regulatory limits at workplaces was investigated. In total, the results from 39 Swedish water purification plants are included in the study. The methodology includes long-term air measurements with alpha track detectors, and short-term air measurements with AlphaGUARDs. In addition, water samples were collected in order to analyze the radon concentration in the untreated and treated water. The results show that several plants experience elevated radon levels in the indoor air and in some cases the exposure could be problematic. Several connections were investigated without finding apparent connections for those cases. For example, the relation between radon concentration in the water and radon level in the indoor air was investigated and the connection between the volume of water treated and the radon level in the indoor air. Calculations with transfer coefficients indicate that the transfer of radon into the indoor air is relatively small. However, there can also be contribution from other radon transfer pathways, such as soil and buildings, which may have an impact on the radon levels in the indoor air.
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Labed, Véronique. "Etude de la perméation du radon 222 à travers les membranes plastiques : application à une méthode de mesure du radon dans l'eau et les sols saturés /." Saclay : Commissariat à l'énergie atomique, 1991. http://catalogue.bnf.fr/ark:/12148/cb354948552.
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Klein, Didier. "Réalisation et applications d'un compteur proportionnel pour des mesures de terrain en continu du Radon 222." Besançon, 1990. http://www.theses.fr/1990BESA2041.
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Botha, Ryno. "Variability and interannual trends in the climatology of radon-222 at two Southern Hemisphere coastal baseline sites." University of the Western Cape, 2021. http://hdl.handle.net/11394/8106.
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Philosophiae Doctor - PhDThis thesis characterises and discusses two continuous coastal Southern Hemispheric (SH) atmospheric radon (222Rn) signals. Large-scale atmospheric circulation patterns are important components of the climate system implicated in driving catastrophic events such as extreme droughts and mega-wildfires and radon measurements at coastal sites provide valuable information on interactions of terrestrial and oceanic air masses on regional to hemispheric scales. The main collaborating SH atmospheric observatories in this study are located at Cape Grim (CGO, Tasmania, 1992-2017) and Cape Point (CPO, South Africa, 1999-2017). The radon signal from a high-altitude remote island oceanic site in the Northern Hemisphere Mauna Loa Observatory (MLO, Hawaii, 2004-2015) is also incorporated for comparison purposes. The CGO radon signal is the longest and most sensitive in current existence. A variety of statistical, spectral, trend, back-trajectory and trajectory density methods are utilized in this study to illuminate features of the datasets on multiple scales. Strongly skewed radon distributions occur, with a large number of events falling into a compact range of low values (corresponding to marine air-masses) and a smaller number of events spread over a wide range of high-radon values (continental air-masses). Making use of Fast Fourier Transform power spectral analysis, prominent periodicities are identified on diurnal and annual scales. Inter-annual variations in seasonal and diurnal radon and meteorological characteristics, indicating changes in the continental/oceanic atmospheric mixing state, are evident especially during the period from 2012 to 2017, perhaps associated with the strong El-Niño southern oscillation centred on 2015. A slow but systematic decline in CGO and CPO radon levels is evident over the dataset, associated with fewer continental and more marine air-masses impacting the coastal stations. The long-term trends observed in the atmospheric radon signal may indicate changes in SH circulation patterns over time, perhaps associated with climate change effects.
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Labed, Véronique. "Etude de la perméation du radon 222 à travers les membranes plastiques : application à une méthode de mesure du radon dans l'eau et les sols saturés." Brest, 1991. http://www.theses.fr/1991BRES2018.
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Dans le but d'ameliorer la sonde barasol (balise de mesure du radon dans les sols), en la rendant operationnelle dans les terrains satures en eau et sous certaines contraintes de pression, nous avons etudie la permeation du radon 222 a travers les membranes plastiques. Le terme permeation gazeuse decrit un phenomene de transfert de gaz a travers certains polymeres. Originale par rapport aux etudes classiques ou la permeation s'effectue entre deux phases gazeuses, la presente etude concerne le transfert du radon 222 entre de l'eau et de l'air via la membrane. Un premier dispositif experimental a permis de tester les membranes, en suivant l'evolution temporelle du phenomene, par la mesure de l'activite volumique du radon 222 dans l'eau et dans l'air. Quelques membranes ont ete qualifiees par nos experiences vis-a-vis de la permeation du radon (coefficient de permeation, coefficient de partage apparent, energie d'activation), en fonction de la temperature de l'eau. Un deuxieme montage experimental adapte a la sonde barasol a finalement permis de caracteriser la reponse de celle-ci en presence des membranes precedemment selectionnees. Dans ces conditions, nous avons montre qu'il est possible de mesurer le radon dans des eaux naturelles d'une activite volumique de 10#3 bq. M##3
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Dabrowski, Jessica Stephanie. "Radium isotopes and radon-222 as tracers of sediment-water interaction in Arctic coastal and lacustrine environments." Thesis, Massachusetts Institute of Technology, 2020. https://hdl.handle.net/1721.1/128993.
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Thesis: S.M., Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), 2020Cataloged from student-submitted PDF of thesis.
Includes bibliographical references.
Arctic marine and lacustrine systems are experiencing rapid warming due to climate change. These changes are especially important at the interface between sediments and surface waters because they are hotspots for biogeochemical transformations such as redox reactions, nutrient consumption and regeneration, organic matter leaching and degradation, and mineral weathering. Radium isotopes (²²³Ra, ²²⁴Ra, ²²⁶Ra, ²²⁸Ra) and radon-222, naturally occurring radioactive isotopes produced in sediments, are well-suited as tracers of nutrients, trace metals, and organic matter cycling processes at the sediment-water interface. In this thesis, I have applied radon-222 and the quartet of radium isotopes to study fundamental processes in subarctic lakes and on the Arctic continental shelf. First, radon-222 is used to quantify groundwater discharge into a shallow, tundra lake on the Yukon-Kuskokwim Delta in Alaska in summer of 2017.
Radon-derived groundwater fluxes were then paired with methane (CH₄) measurements to determine delivery rates of methane into the lake via groundwater. Groundwater CH₄ fluxes significantly exceeded diffusive air-water fluxes from the lake to the atmosphere, suggesting that groundwater is an important source of CH₄ to Arctic lakes and may drive observed CH₄ emissions. Higher CH₄ emissions were observed compared to those reported previously in high latitude lakes, like due to higher CH₄ concentrations in groundwater. These findings indicate that deltaic lakes across warmer permafrost regions may act as important hotspots for methane release across Arctic landscapes. Then, the quartet of radium isotopes is used to study the impacts of storms and sea ice formation as drivers of sediment-water interaction on the Alaskan Beaufort shelf.
The timeseries presented in this study is among the first to document the combined physical and chemical signals of winter water formation in the Beaufort Sea, made possible by repeat occupations of the central Beaufort shelf. Radium measurements are combined with inorganic nitrogen and hydrographic measurements to elucidate the episodic behavior of winter water formation and its ability to drive exchange with bottom sediments during freeze-up.
by Jessica Stephanie Dabrowski.
S.M.
S.M. Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution)
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Guérin, Frédéric. "Production et mécanismes de migration du radon-222 dans les milieux fissurés : application à la recherche des discontinuités perméables du socle cristallin." Paris 6, 1991. http://www.theses.fr/1991PA066145.
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Dans le cadre de la prospection des ressources en eau en milieu fissure, une methodologie d'etude des emanations de radon-222 dans les gaz des sols est proposee. Cette methodologie repose sur l'utilisation croisee de methodes telles que la geostatistique, la modelisation numerique, le dosage complementaire du co#2 et la spectrometrie gamma de terrain. Trois parties sont essentiellement developpees: le developpement theorique des processus de production et de migration du radon-222; la recherche au plan experimental (etudes de sites) des facteurs de variation du signal radon. Plusieurs tendances sont mise en evidence, associant le radon a la fracturation, l'hydrogeologie des sites et le contexte petrographique; la recherche par simulation d'un equivalent theorique a ces tendances. Un interet particulier est porte a la differenciation des anomalies de radon liees aux radioelements de celles associees aux fractures permeables
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Fruchtnicht, Erich Harold. "Radon (Rn-222) and thoron (Rn-220) emanation fractions from three separate formations of oil field pipe scale." Thesis, Texas A&M University, 2004. http://hdl.handle.net/1969.1/1231.
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Over the course of normal oil well operations, pipes used downhole in the oil and petroleum industry tend to accumulate a mineral deposit on their interior, which restricts the flow of oil. This deposit, termed scale, will eventually occlude the interior diameter of the pipe making removal from service and descaling a cost effective option. The pipes are sent to cleaning yards where they remain until descaling can be performed. This storage period can potentially create a health concern not only because of the external radiation exposure but also because of the radon gas emissions, both of which are due to the radioactive minerals contained in the scale. It was believed that the structure of the scale is formed tightly enough to prevent much of the radon from becoming airborne. The goal of this research was to determine the emanation fractions for the rattled scale samples from three formations. A high purity germanium detector was used to measure the activities of the parents and progeny of radon, and electret ion chambers were used to measure the concentration of radon emanated from the scale. The emanation fractions of between 4.9x10-5 and 1.08x10-3 for radon were a factor of approximately 100 smaller than previous research results. For thoron, the fractions were and 5.72x10-8 and 4.92x10-7 for thoron with no previous research to compare. However, information that pertains to the temperature dependence of emanation was included in this research and was not available for previous, similar research. Therefore, differences in the environment (e.g., temperature, humidity, etc.) in which the previous experiments were conducted, as well as differences in the scale formation types used, could account for the discrepancy. In addition, measuring the emanation fractions of the rattled scale was a method of determining whether surface to volume ratio dependence existed. After acquiring the emanation fractions, insufficient evidence of any surface to volume ratio dependence could be found.
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Hirao, Shigekazu, Yuki Nono, Hiromi Yamazawa, Jun Moriizumi, Takao lida, and Katsuhiro Yoshioka. "Development and verification of long-range atmospheric transport model of radon-222 and lead-210 including scavenging process." American Institite of Physics, 2008. http://hdl.handle.net/2237/12039.
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El, Moussaoui Brahim. "Contribution à l'étude théorique et expérimentale des aérosols descendants du radon-222 et à l'étude des performances de certains disposiifs filtrants." Paris 12, 1989. http://www.theses.fr/1989PA120005.
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Ce travail concerne les mecanismes de formation et d'evolution de la distribution dimensionnelle des aerosols radioactifs issus du radon-222 dans differents types d'atmospheres controlees, ainsi que le comportement de certains dispositifs filtrants vis-a-vis de la composante submicronique des aerosols incidents. Une theorie d'evolution en temps reel des derivees a vie courte du radon sur la base de la diffusion du #2#1#8po libre sur les aerosols presents et la coagulation des particules radioactives formees sibt abirdees. L'importance du role de la distribution des particules naturelles en tant que support de l'aerosol radioactif est mis en evidence. Des experiences en enceinte controlee, destinees a valider l'approche theorique sont realisees. La filtration de media a structure fibreuse polydispersee et chargee, puis de masques respiratoires filtrants dans le domaine des fines particules est egalement etudiee
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Huet, Christelle. "Etude des caracteristiques physiques - distribution en taille, fraction libre, facteur d'équilibre - des dérives à vie courte du radon-222 en atmosphère domestique." Brest, 1999. http://www.theses.fr/1999BRES2027.
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Aujourd'hui, on se preoccupe d'avantage de l'exposition individuelle aux faibles doses de radiations. L'inhalation des derives a vie courte du radon ( 2 1 8po, 2 1 4pb, 2 1 4bi et 2 1 4po) represente en moyenne 50% de la dose de radiations totale recue par l'individu. L'evaluation du facteur de risque requiert de connaitre le comportement des derives et leurs caracteristiques physiques (taille, fraction libre, facteur d'equilibre) en atmosphere domestique. Dans un premier temps, nous avons developpe des dispositifs de collection et de detection appropries. Nous avons concu une batterie de diffusion a lits granulaires pour l'etude de la distribution en taille du 2 1 8po et du 2 1 4pb libres. La mise en uvre de la methode de comptage alpha global tels a permis d'augmenter la precision sur les activites volumiques. De plus, les methodes inverses eve et twomey, permettant de remonter a la distribution en taille des descendants, ont ete developpees. Enfin, pour mesurer en continu la fraction libre et le facteur d'equilibre, un dispositif original, consistant en un canal de diffusion annulaire et un filtre de reference en parallele, a ete concu. Les techniques developpees ont ensuite ete mises en uvre dans une habitation traditionnelle. Avec l'aerosol age, la fraction libre est importante (0,31 en moyenne) et le facteur d'equilibre faible. En presence de sources d'aerosols, la tendance s'inverse. La relation de correlation obtenue entre ces grandeurs peut ainsi servir de modele pour l'atmosphere domestique. Un diametre moyen vers 0,8 nm est trouve pour le 2 1 8po et le 2 1 4pb nanometriques. Pour la composante attachee, le mode d'accumulation se situe entre 160 et 270 nm selon la source. Parfois un mode de nucleation est observe. Enfin, les resultats experimentaux sont confrontes a ceux du modele praddo, permettant de le valider pour le comportement des descendants libres. De plus, un bon accord est obtenu entre les distributions en taille experimentales et celles trouvees par praddo.
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ANDRADE, LIMA RICARDO de. "Avaliacao da dose na populacao da regiao urano-fosfatica do Nordeste que utiliza os recursos hidricos da regiao." reponame:Repositório Institucional do IPEN, 1996. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10470.
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Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
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LOPES, PATRICIA da C. "Estudo da variação sazonal das concentrações de sup(222)Rn em amostras de água do mar nas enseadas de Ubatuba, para a estimativa da descarga de águas subterrâneas." reponame:Repositório Institucional do IPEN, 2005. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11353.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
FAPESP:02/08902-9
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FERRY, CECILE. "La migration du radon-222 dans un sol. Application aux stockages de residus issus du traitement des minerais d'uranium." Paris 11, 2000. http://www.theses.fr/2000PA112086.
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Les residus issus du traitement des minerais d'uranium contiennent du radium-226 en quantites relativement importantes. Ce radionucleide genere, par decroissance radioactive, un gaz lui-meme radioactif, le radon-222. L'inhalation du radon et de ses descendants constituant un risque sanitaire pour l'homme, les residus, stockes en surface, sont recouverts par une ou plusieurs couches de materiaux peu radioactifs. Afin d'estimer au mieux la voie aerienne de l'impact sur l'environnement des stockages de residus, en particulier pour le long terme, il est necessaire de determiner et de comprendre les mecanismes qui controlent l'emission du radon a la surface d'un milieu soumis aux contraintes meteorologiques. Un modele de migration du radon dans la zone insaturee des sols est developpe a cet effet. Il repose sur la modelisation des ecoulements d'air et d'eau dans le milieu poreux etudie, et sur la modelisation du transport de radon par diffusion dans les pores et advection dans la phase gazeuse de ce milieu. Le code traci (transport de radon dans la couche insaturee) calcule ainsi l'evolution dans le temps des teneurs en eau, des vitesses de darcy des fluides presents dans les pores, des concentrations de radon dans la phase gazeuse et des flux de radon a la surface du materiau, le tout en fonction des conditions meteorologiques. Ses resultats sont confrontes a des mesures realisees en continu dans un residu minier, ainsi que dans le materiau de couverture d'un site de stockage de residus. Les parametres d'entree des simulations sont choisis en fonction de la texture du materiau etudie. Au regard des incertitudes existant sur les mesures et sur les caracteristiques hydriques reeles des materiaux, les valeurs calculees par traci sont en bon accord avec les valeurs mesurees, au moins sur le long terme. L'analyse des resultats obtenus revele en outre une bonne comprehension de la plupart des phenomenes transitoires observes.
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CACCURI, LILIAN S. "Avaliação da exposição ocupacional ao sup(222)Rn no galpão da salvaguardas do IPEN." reponame:Repositório Institucional do IPEN, 2007. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11598.
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Dissertação (Mestrado)
IPEN/D
Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP
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Kerouanton, David. "Etude de la composante ultrafine issue du radon-222 à partir d'un canal de diffusion annulaire muni d'un détecteur de traces nucléaires." Brest, 1996. http://www.theses.fr/1996BRES2032.
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La fraction non-attachee des derives a vie courte du radon-222 dans l'air est constituee de particules dont le diametre varie de 0,5 nm a quelques nanometres. Cette composante, qui joue un role tres important sur le calcul des doses recues par les individus, est encore insuffisamment connue notamment en ce qui concerne sa distribution dimensionnelle. Parmi les techniques couramment utilisee pour la collection et l'etude de cette composante ultrafine, les grilles de tamis constituent le moyen le plus simple pour des prelevements ponctuels. De maniere a disposer d'une technique capable d'integrer les fluctuations de la concentration des derives fins du radon-222, nous avons experimente un canal de diffusion annulaire dont le cylindre interne est recouvert d'un film detecteur de traces alpha, du type lr115 de kodak, associe a une epaisseur de mylar de 13 m. L'efficacite theorique de collection des particules par le canal de diffusion annulaire a ete obtenue par le calcul analytique. La reponse du film lr115 aux particules alpha emises par le po-218, a differentes energies et sous des angles d'incidence differents, a ete etudiee et modelisee pour des conditions standards de developpement. Par la suite, le canal de diffusion annulaire a ete experimente dans une enceinte close contenant un melange d'air filtre et de radon. L'analyse du nombre de traces releve sur les films, a l'aide d'une technique a etincelage, permet effectivement une mesure integree dans le temps de la concentration en po-218 sous forme non-attachee. A partir de cette procedure, il est aussi possible d'obtenir des informations sur le spectre dimensionnel de cette composante en etudiant les variations de la densite de traces sur toute la longueur du film a l'aide de techniques numeriques d'inversion non lineaire des donnees. Les resultats obtenus sur ce dernier point sont tres encouragenats et la technique est appelee a des developpements futurs
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Butler, Anna Helena. "Radon-222, radium-226, uranium and major ionic concentrations in the groundwater of the Georgia Piedmont : their relationship with geology and each other." Thesis, Georgia Institute of Technology, 1990. http://hdl.handle.net/1853/30759.
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Guadagnolo, Davide. "Investigation of the groundwater-river interaction, using Radon-222 as a natural tracer, in a karst Mediterranean environment like in the case study of the Bussento river basin." Doctoral thesis, Universita degli studi di Salerno, 2010. http://hdl.handle.net/10556/115.
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2008-2009The naturally-occurring radionuclides have proven to be powerful tools for assessing the time dependency of GSI processes. The radionuclide 222Rn (referred to as radon) has the advantage of being a radioactive noble gas, i.e. a (short-lived) radionuclide that is chemically inert and can easily be detected on site. Since radon is produced in every mineral matrix and is soluble in water, it occurs ubiquitously in all natural waters. Radon concentrations that are usually found in groundwater are about three to four orders of magnitude higher than radon concentrations typical for surface waters. The aim of this thesis work is to use radon as a tracer to investigate the groundwater-river interaction, in particular to perform an useful methodology for the localization of the contributions of groundwater to the river bed, in a typical karst environment, the Bussento river basin. The Bussento river basin, located in the south-east of Campania region, shows interesting issues related to water assessment and management. Complex interactions and exchanges between surface and groundwater exist, influencing also on-shore and off-shore submarine springs. Therefore, gaining river segments from karst groundwater and losing river segments towards the aquifer are recognized. Groundwater protection for drinking domestic use, riverine wild-life conservation and coastal water quality require a progressively optimized knowledge of these interactions. This thesis work comes at the end of a two years and a half experimentation and investigation about the surface and groundwater bodies in the Bussento river basin. The implementation of the radon measurement techniques has confirmed the perspective of using these methodologies in a karst Mediterranean environment to investigate the complex interactions and exchanges between streamflow and groundwater. Experimental data about radon concentrations, in addition to physical-chemical data and streamflow rate, have been acquired during monthly measurement campaigns. Different measurement techniques have been tested and compared allowing to determine a precise protocol for sample collection and for laboratory measurements. From the data analysis, it has been established the possibility of localizing groundwater influx in riverbed. In fact, superficial waters have been shown to have a markedly different radon content from groundwater, the latter differing in radon concentrations if originating from different karst typologies. In order to provide a physical scheme of the complex recharge, storage and routing system of the river karst area, a preliminary, physicallybased, conceptual model has been built-up. The data have also enabled to individuate a spatial and temporal variability of the radon activity concentration along the river, and to identify, as mentioned above, three typologies of karst springs assumed in the conceptual model. It has been experimentally verified the possibility of making the hydrograph separation both on a seasonal scale and referring to a flood event. Moreover, a preliminary investigation and modeling of radon diffusion from water to the atmosphere have been made along two selected segments of the river. In fact, analyzing the radon concentration gradients determined during different sampling campaigns, radon exchange rates according to three different models have been estimated.
VIII n.s.
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Smith, Lauren A. "Using radon-222 as a tracer of mixing between surface and ground water in the santa fe river sink/rise system." [Gainesville, Fla.] : University of Florida, 2004. http://purl.fcla.edu/fcla/etd/UFE0003260.
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Smith, Bruce D. "The distribution of radon-222 in the ground water of the north-central Tucson basin and its relationship to the hydrogeology." Thesis, The University of Arizona, 1988. http://hdl.handle.net/10150/192005.
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A reconnaissance study of ²²²Rn concentrations in the ground water of the North-Central Tucson basin revealed a range of concentrations from 80 to 1400 pCi/L in wells, and 60 to 1260 pCi/L in domestic waters. Estimated degradation of Rn in water from wells to homes ranges from 8 to 50%. The interior well field of mid-Tucson, may represent background concentrations of Rn with a mean value of 250 pCi/L. The limited data define an anomalous trend (500 to 1400 pCVL) of ²²²Rn paralleling the Santa Cruz River area. 222Rn concentrations above 500 pCVL correlate positively with temperature, and no low temperature water contains high ²²²Rn levels. Weak inverse correlations of ²²²Rn with pumping bowl depth, pumping water level and average upper perforation intervals are evident. It is concluded that the source of ²²²Rn is close to the well bore. Considered are several possible hypothesis and mechanisms responsible for the anomalous Santa Cruz ²²²Rn trend, including mechanisms related to water circulation along the Santa Cruz fault, lithology, and aquifer compaction.
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CAZULA, CAMILA D. "Dosimetria de sup(222)Rn no ar em ambientes localizados acima e abaixo do nível do solo." reponame:Repositório Institucional do IPEN, 2015. http://repositorio.ipen.br:8080/xmlui/handle/123456789/23739.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Dissertação (Mestrado em Tecnologia Nuclear)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
FAPESP:13/01841-9
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Weiss, Matthew. "Evaluation of Geophysical and Thermal Methods for Detecting Submarine Groundwater Discharge (SGD) in the Suwannee River Estuary, Florida." Scholar Commons, 2006. http://scholarcommons.usf.edu/etd/3811.
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Submarine groundwater discharge (SGD) represents a significant portion of the total discharge from coastal aquifers through diffuse seepage and point source springs, but can be difficult to locate. SGD is important as it can be a source of nutrients to estuaries and other coastal ecosystems. In an effort to evaluate geophysical and thermal methods for detecting SGD on the Florida Gulf coast, a suite of water-borne surveys were run in conjunction with aerial thermal imagery over the lower Suwannee River and estuary in March and September 2005. Thermal imagery exploits temperature differences between discharging groundwater and surface water. Thermal images were collected in March (dry season), at the end of winter, and at night to maximize the differences between warm groundwater and colder surface water. Generally pore waters in zones of concentrated SGD should be fresher, and hence more resistive than "background" values. Marine streaming resistivity data can detect pore water resistivity variations and were collected alongside continuous 222Rn and CH4 sampling from surface waters. Naturally occurring tracers, 222Rn and CH4, are used as the "standard" against which resistivity and thermal images are compared.
Based on the expected properties of discharging groundwater, we hypothesize that in zones of elected tracer concentrations, increased thermal image temperatures and increased terrain resistivities will be observed. The data set as a whole supports this hypothesis. However, regional-scale correlations are clearly and significantly influenced by factors other than SGD including thermal-image noise, the presence of the fresh/salt water interface, and a large regional tracer gradient generated by a first-order spring. At local scales (tens to hundreds of meters) there are no significant correlations between thermal image temperature and tracer concentrations, due at least in part to flight-line edge effects that dominate the thermal imagery. After correcting for regional trends,significant correlations between tracer concentration and log resistivity exist only in a subset of the data that lies offshore. Because neither thermal imagery nor streaming resistivity data consistently support the hypotheses, this study suggests that neither method by itself is reliable for detecting SGD in this area
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Lamy, Sophie. "Contribution à l'étude du radium 226, du radon 222 et de leurs descendants dans des milieux liquides naturels : application à la Franche-Comté." Besançon, 2003. http://www.theses.fr/2003BESA2012.
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Cette thèse a permis de définir une méthodologie d'analyse des émetteurs alpha en milieux dispersés par scintillation liquide, afin de déterminer l'impact de l'emploi du 226Ra par l'horlogerie dans les eaux de Franche-Comté. L'analyse de rivières proches de sites horlogers (Doubs, Loue, Dessoubre) n'a pas montré de radium sous forme dissoute, mais du radon et ses descendants ont été décelés à des activités volumiques comprises entre 1 et 5,5 Bq. L-1. L'analyse comparative d'autres eaux de surface de la région a révélé des activités volumiques en radon de 91 Bq. L-1 au maximum. Des sédiments prélevés dans le lac de Chaillexon, en aval du principal pôle horloger de la région, ont montré l'accumulation de césium-137 qui a été utilisé comme chrono-indicateur. Ainsi, une légère augmentation de l'activité massique radium a été mise en évidence à des profondeurs datant des années 50-65, mais corréler cette hausse et une activité horlogère particulière à la même époque nous a été impossibleThis thesis work aimed at defining an analysis methodology of alpha emitters in liquid environments by liquid scintillation counting, so as to determine the impact of radium 226 use by watch-making industry in the waters of Franche-Comté. The analysis of rivers close to watch-making industry sites (Doubs, Loue, Dessoubre) did not show any radium in dissolved form, but radon and its daughters were detected from 1 to 5. 5 Bq. L-1. The comparative analysis of other surface waters from Franche-Comté have shown some radon activities up to 91 Bq. L-1. Some sediments taken from the bottom of lake Chaillexon, downstream of the main watch-making industry site of the region, show a caesium 137 accumulation which has been used as a chrono-indicator. Thus, a slight increase of the radium mass activity was pointed out at depths dated the 50-65, nevertheless, correlating this increase and an origin due to watch-making industry at the same period has been impossible
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FILIPPI, DOMINIQUE. "Etude et developpement d'un instrument aeroporte destine a la collecte des aerosols et a la mesure du radon 222 par son depot actif." Paris 6, 2000. http://www.theses.fr/2000PA066507.
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L'etude et le developpement d'un instrument aeroporte destine a la collecte des aerosols et a la mesure du radon 222 constitue le cadre de cette these. Apres avoir rappele quelques generalites sur le radon et introduit la methode de mesure du radon 222 par son depot actif naturel, l'auteur quantifie le rendement de la sonde dynamique sextant avionique / lsce utilisee pour la collecte isocinetique des aerosols. Ces estimations sont obtenues a partir de simulations axisymetriques de l'ecoulement autour de la sonde a differentes vitesses subsoniques, puis par le calcul de trajectoires de particules a l'entree de la sonde pour plusieurs coefficient de debit. L'effet de l'angle d'incidence y est aussi discute ainsi que le critere isocinetique en pression necessaire a la mise en uvre de cette sonde. Pour conclure cette etude theorique, l'auteur a estime les depots lors du transport des aerosols dans les conduits. L'instrument construit, nomme avirad, est alors presente de meme que les choix technologiques adoptes. L'auteur a pu valider son instrument lors de la campagne aeroportee staaarte 99. Les mesures obtenues sont presentes en conclusion de cette these.
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Pereira, Osvaldo Luiz dos Santos. "Estudo comparativo das respostas de monitores de Rn-222 que utilizam o CR-39 como detector de traços de partículas alfa." [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/278128.
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Orientador: Julio Cesar Hadler NetoDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin
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Resumo: Neste trabalho foi realizado estudo comparativo entre as respostas de três monitores, o NRPB, o monitor de acrílico (geometria filme fino) e o monitor de alumínio (geometria filme fino), em exposições controladas e mistas. As exposições consistiram em colocar os monitores em uma campânula com uma fonte de rádio-226 interna. Os detectores CR-39 analisados foram todos internos aos monitores. Foi concluido que os monitores em geometria de filme fino forneceram atividades da ordem de 15% inferior ao NRPB. Todos os monitores responderam da mesma forma, quando em ambiente controlado. E em relação ao tipo de material, plástico condutor ou plástico dielétrico, do NRPB, responderam da mesma maneira, em ambientes sem ventilação. O monitor confeccionado com material condutor responde da mesma forma que aquele confeccionado com material dielétrico
Abstract: This work was a comparative study between the responses of three monitors, the NRPB, an acrylic monitor (in thin film geometry) and the aluminum monitor (also thin film geometry) in controled and mixed environment. The experiments consisted on placing the monitors in a plastic tube, with a radio-226 source internal. Only internal CR-39 plastic detectors were analyzed in this work. It was found that the monitors in thin film geometry had activities response of approximately 15% less than the NRPB monitors. All monitors responded the same way when in controlled environment. Related to the type of material, conductive plastic or dielectric (insulator) plastic, the NRPB, in environments without ventilation, responded in the same way
Mestrado
Física Nuclear
Mestre em Física
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MANOCCHI, FABIO H. "Monitoração de Rn-222 nos galpões de armazenamento de rejeitos radioativos do IPEN." reponame:Repositório Institucional do IPEN, 2014. http://repositorio.ipen.br:8080/xmlui/handle/123456789/23275.
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Dissertação (Mestrado em Tecnologia Nuclear)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
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Dillon, Marc Everett. "A study of radon-222 in groundwater in the Athens region of northeast Georgia : concentration as a function of the geologic and hydrogeologic conditions." Thesis, Georgia Institute of Technology, 1989. http://hdl.handle.net/1853/33443.
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FARIAS, LUCIANA A. "Calibracao de uma linha de emanacao para determinacao de sup(222) Rn em amostras de agua do mar." reponame:Repositório Institucional do IPEN, 2002. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11019.
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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
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Pritchard, Jodie Lee, and jodie_pritchard@hotmail com. "Dynamics of stream and groundwater exchange using environmental tracers." Flinders University. School of Chemistry, Physical & Earth Science, 2006. http://catalogue.flinders.edu.au./local/adt/public/adt-SFU20060407.122526.
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Regions of surface water and groundwater exchange are major sites for the transfer and transformation of solutes and nutrients between stream and subsurface environments. Conventional stream and groundwater exchange investigations are limited by methodologies that require intensive field investigations and/or the set-up of expensive infrastructure. These difficulties are exacerbated where hydraulic gradients are very low and stream discharge highly variable. This thesis uses a suite of environmental tracers (Cl-, Rn-222, H-2 & O-18, Sr-87/Sr-86) to characterise the extent of stream and groundwater exchange between a sand bed stream and adjacent alluvial aquifer in a subtropical catchment (the Wollombi Brook) of eastern Australia. The aims were to identify sources and relative contributions of different sources of groundwater to stream discharge and specifically to improve the methodology of using Rn-222 to obtain quantitative estimate of groundwater fluxes.
The sensitivity of the Rn-222 technique for identifying groundwater discharge based on the Rn-222 concentration in stream water was improved via an iterative numerical approach to account for Rn-222 loss from stream water via turbulent gas exchange and radioactive decay. Optimal distances between stream sampling points for defining the magnitude of groundwater discharge to stream flow based on Rn-222 concentrations in stream water is a function of average stream velocity and water depth. The maximum allowable distance between sampling points for determining the magnitude of groundwater discharge to the Wollombi Brook was 2 km. This work showed that groundwater discharged to all reaches of the Wollombi Brook during baseflow and flood recession conditions. Alluvial groundwater contributed less than 30% of water to stream flow in the mid Wollombi Brook catchment.
Dilution of steady-state Rn-222 concentrations measured in transects from the stream to the alluvial sediments showed that significant surface water and groundwater exchange occurs even when gradients between surface water and groundwater are low. Lateral stream water influx to the adjacent alluvial aquifer was more extensive in the lowland areas of the Wollombi Catchment during low flow than flood recession conditions. Extensive stream water influx to the adjacent alluvial aquifer occurs contrary to the net direction of surface water and groundwater flux (as indicated by hydraulic gradients toward the stream channel). The rate of stream and groundwater exchange within the adjacent alluvial aquifer appears to be greatest during baseflow conditions. Fresh alluvial groundwater appeared to provide a buffer against higher salinity regional groundwater discharge to the alluvial aquifer in some reaches of the Wollombi Brook catchment. Pumping of the alluvial aquifer and diversions of surface water may jeopardise the water quality and volume of the alluvial aquifer and induce water flow from the regional aquifer toward the stream, potentially salinising the fresh alluvial aquifer and subsequently the stream.
The change in the Cl- concentration and the variation in slope of the deuterium � oxygen-18 line between consecutive stream sampling points could be used to differentiate between regional and alluvial groundwater discharge to stream flow. Incorporating this information with three-component end-member mixing using [Sr2+] and Sr-87/Sr-86 showed that stream and alluvial groundwater exchange within the stream channel was highest in the lowland floodplains during low flow conditions. The least stream and alluvial groundwater exchange occurred in the low streambed gradient mid reaches of the Wollombi Brook regardless of stream stage. The greatest difference in the degree of stream and alluvial groundwater exchange between high and low stream stages occurred in the lowland floodplains of the Wollombi Brook.
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Le, Druillennec Thomas. "Apport de la caractérisation de la variabilité des concentrations en radon-222 dans l'eau à la compréhension du fonctionnement d'un aquifère en milieu fracturé de socle : exemple du site de Ploemeur." Brest, 2007. http://www.theses.fr/2007BRES2039.
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Les aquifères fracturés hétérogènes se développant dans les roches cristallines, telles que les schistes et les granites, assurent 20% de l’alimentation en eau potable de la Bretagne. Ces milieux fracturés présentent une large gamme de perméabilités. Dans ces aquifères, les circulations de fluides et le transport des éléments dissous dans l’eau sont fortement dépendants de la géométrie du réseau de fractures. Une meilleure compréhension du fonctionnement hydrogéologique de ces systèmes est essentielle pour la gestion et la protection de ces ressources en eaux souterraines. Le radon-222 est un gaz rare radioactif dissous dans l’eau et issu de la chaîne de désintégration de l’uranium-238 contenu dans la roche encaissante de l’aquifère. Les concentrations en radon dans les eaux souterraines sont donc susceptibles d’apporter des informations sur la surface de contact entre l’eau et la roche ainsi que d’être utilisés comme ml traceur des échanges hydrauliques entre les différentes zones de l’aquifère. Trois résultats principaux ont été obtenus dans cette étude: 1. Une caractérisation détaillée des activités volumiques du radon dans l’eau de l’aquifère de Ploemeur (Morbihan) a été réalisée. Une variabilité spatiale importante des concentrations en radon dans l’eau a été mise en évidence dans l’aquifère, la gamme de concentrations mesurées s’étendant de 0 à 1500 Bq. L-¹. 2. L’influence de l’épaisseur des fractures sur la quantité de radon dissous dans l’eau a été mise en évidence lors de la modélisation des activités volumiques du radon dans l’aquifère. En effet, les résultats satisfaisants obtenus lors de l’utilisation d’un modèle considérant le réseau de fractures sous la forme, d’une fracture unique semble souligner le rôle prépondérant joué par les propriétés géométriques des fractures. 3. La mesure de la concentration en radon dans l’eau de l’aquifère pendant des essais de pompages a mis en évidence une augmentation de l’activité volumique en radon lorsque les ressources en eau souterraines sont sollicitées. Cette évolution semble liée à l’existence de flux hydrauliques entre les zones très perméables du système, constituées des fractures principales d’épaisseur importante, et les zones beaucoup moins perméables, telles que la matrice rocheuse peu altérée et le réseau de fractures secondaires. La comparaison de la variabilité des activités volumiques du radon dans l’eau avec celle d’autres traceurs a permis de conforter cette hypothèse. En effet, des corrélations ont été établies entre la concentration en radon dans l’eau et le rapport NO3/SO4² ainsi que la teneur en SF6 des eaux souterraines. Les résultats obtenus à l’aide de ces traceurs semblent confirmer une contribution de l’eau contenue dans la matrice rocheuse au flux d’eau circulant dans le réseau de fracturesHeterogeneous fractured aquifers which developed in. Crystalline rocks, such as schist or granite, supply 20% of tap water production cf Brittany. These fractured media present a large range of permeability. In these aquifers, fluid flow and transport cf elements dissolved in water are strongly related on the geometry of the fractured network. Increasing the knowledge of the hydrogeological behaviour of the aquifer is fondamental for the management and the protection of the groundwater resources. Radon-222 is a radioactive noble gas produced from radium-226 further to the radioactive decay of uranium-238; it occurs naturally in ground waters and derives primarily from U-rich rocks and minerais that have been in contact with water. Radon-222 concentrations in waters are hable to provide significant and relevant information on both the geometry of a fracture network and the flow distribution. Furthermore, radon may also be used as a tracer in the aquifer of water exchanges between zones of variable permeability. Three main results were obtained in this study : 1. An accurate characterisation of the radon concentrations in water was carried out in the Ploemeur aquifer (Brittany, France). These results higjilight die variability in die spatial and vertical distributions of ²²²Rn activity in groundwater together with a wide range of concentrations extending from 0 to 1500 Bq. L-¹. 2. The influence of fracture aperture on radon content in -groundwater bas been demonstrated with the modelling of radon concentration. Indeed, the satisfactory results obtained with a simple crack model highlight that the geometry of the fracture network controls the radon activity in groundwater. 3. Thus, the results of pumping tests performed in the boreholes improved our understanding of the system. After the pumping test, an increase of the radon content in groundwater occurred and evidenced a contribution of a radon-rich water to supply tle flow rate that seems to come from the low-permeability rock matrix. Indeed, a water flow seems to occur between the most permeable zones of the aquifer, made up of the main flow pathways, and the zones with low permeability, consisted of the unfractured rock matrix and secondary fractures of lower permeability. Then, we compared the variability of radon volume activity with the evolution of the NO3/SO4² ratio and the SF6 content of groundwater. The results obtained with these tracers seem to allow the hypothesis of a water flux from the rock matrix te the fractured network
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Arnoux, Marie. "Interactions lacs-eaux souterraines et sensibilité aux changements climatiques et environnementaux." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS581/document.
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Face à l’augmentation actuelle des pressions anthropiques sur les réserves d’eaux douces, leur préservation, et notamment celle des eaux souterraines, est primordiale. Les interactions entre les lacs et les eaux souterraines sont étudiées ici afin d’identifier si certains lacs peuvent être utilisés comme indicateurs de changements qualitatifs et quantitatifs des eaux souterraines, spécialement au Québec où plus de 10% du territoire est recouvert d’eaux douces avec un million de lacs recensés. Une vingtaine de petits lacs de Kettle, situés dans des dépôts fluvioglaciaires, ont été spécifiquement choisis pour leur très probable interconnexion avec les aquifères libres peu profonds. Les flux d'eaux souterraines ont été quantifiés via les bilans hydrologiques des lacs couplés aux deux traceurs naturels des eaux souterraines que sont les isotopes stables de la molécule d’eau et le radon 222.A l’échelle régionale, ces lacs présentent un apport annuel et un temps de renouvellement relativement rapide par les eaux souterraines. A l’échelle locale, la modélisation journalière multicouches d’un lac témoin (le lac Lacasse) montre l’importance de la mesure des traceurs, et leur complémentarité, sur la colonne d’eau en fonction des saisons. Différents scénarii d’évolution climatique et environnementale ont ensuite été testés sur les bilans hydrologiques à long terme. Les résultats montrent que la sensibilité de la composition isotopique des lacs à l’horizon 2050 face à l’évolution de la recharge est principalement contrôlée par le pourcentage que représente l’apport des eaux souterraines dans le total de leurs apports en eau, avec une sensibilité optimale pour une fraction de 50 à 80% des apports totaux. Par l’amélioration des connaissances sur les interactions entre lacs et eaux souterraines et sur les outils qui les mettent en évidence, ce travail de recherche a montré que la signature géochimique des lacs peut être utilisée comme indicateur du devenir des ressources en eaux souterraines face aux changements climatiques et environnementaux, pour une meilleure gestion durable de ces hydro systèmesIn the face of modern anthropogenic pressures, the preservation of freshwater resources, particularly groundwater, is paramount. This study investigates interactions between small lakes and groundwater in Quebec, where more than 10% of the territory is covered by freshwater including one million inventoried lakes, to determine whether these lakes may be used as indicators of groundwater change. Twenty-one kettle lakes, set in fluvioglacial deposits, have been specifically targeted for this study due to the high likelihood of connection to shallow unconfined aquifers. Groundwater flows were quantified via lake water balances coupled with two natural tracers of groundwater: stable isotopes of water and Radon-222. On a regional scale the majority of these lakes are characterized by an important annual groundwater inflow and a short-to-medium groundwater flushing time. Daily multi-layer modeling of one of the study lakes, Lake Lacasse, highlights the importance of conducting measurements of these complementary tracers on the water column at the local scale. Different climate and environmental change scenarios were tested to determine the long-term evolution of lake geochemistry. The results indicate that the sensitivity of the isotopic composition of lake water to changes in recharge by year 2050 is mainly controlled by the amount of the total lake balance contributed by groundwater, with an optimum sensitivity for 50-80% of the total inflows contributed by groundwater. This research demonstrates that the geochemical signatures of lakes can be used to indicate future groundwater change in response to climate and environmental evolution, which may assist in improvements to the sustainable management of freshwater resources
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Schoonhoven, Martin. "Occupational exposure to radon in a South African platinum mine / M. Schoonhoven." Thesis, North-West University, 2012. http://hdl.handle.net/10394/9832.
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Background: The Platinum mining operations in South Africa mining platinum containing ore from areas where variable amounts of uranium are found, leading to the possibility of occupational exposure to the radioactive disintegration products of Uranium-238 and in particular the gas Radon-222. No scientific data is available for occupational exposure to Radon-222 in South African platinum mining operations. Objective: To determine the risk of occupational exposure to the radioactive disintegration products of naturally occurring Radon-222 gas in a South African platinum mine. Design: Quantitative sampling (personal and static) to establish baseline data on exposure to radioactive disintegration products of naturally occurring Radon-222 gas in a underground South African platinum mine. Setting: The Bafokeng Rasimone platinum mine located 30 km North West of Rustenburg in the Bushveld complex in the North West Province of South Africa. Study subjects: One hundred and seventy four potentially highest exposed underground employees and one hundred and twelve static underground samples were sampled. Method: Personal and area samples were taken on selected employees and in locations using RGM samplers using CR-39 plastic as a detection medium. Employees were selected to sample the highest exposed occupations and static samples were located to sample returning air from levels underneath the sampling point before it is exhausted to the above ground atmosphere. After analysis by an accredited laboratory, the results were converted to exposure following the National Council on Radiation Protection-78 methodology. Main outcome measures: Quantify the relative risks of potentially highest exposed employee`s exposure to the radioactive disintegration products of naturally occurring Radon-222 gas in underground working areas in milliSievert per year. Results: The mean reference background exposure averaged 0.6168 mSv/a with underground personal exposure averaging 0.6808 mSv/a, and underground static exposure averaging 0.8726 mSv/a. These values are substantially below the 50 mSv/a Occupational Exposure Limit, and only pose a slightly elevated risk for the development of lung cancer above the normal back-ground exposure. Mining Team leaders and rock drill operators were identified as the potentially highest exposed employees due to the close proximity to the working face, large amounts of time spent close to the working face and the lower ventilation volumes at the working face, with Team leaders having the highest exposure of the sampled occupations with a average of 1.16 mSv/a. Conclusions: Occupational exposure to radioactive disintegration products of naturally occurring Radon-222 gas in the underground air of a South African platinum mine does not pose a significant risk to the health of employees working in the platinum mine.Thesis (MSc (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2013.
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Lopez, Morgan. "Estimation des émissions de gaz à effet de serre à différentes échelles en France à l’aide d’observations de haute précision." Thesis, Paris 11, 2012. http://www.theses.fr/2012PA112284/document.
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L’objectif de ma thèse est de conduire et d’utiliser les observations de haute précision de gaz à effet de serre pour estimer les émissions de ces gaz à différentes échelles en France, du locale au régionale. Le réseau français de mesure de gaz à effet de serre, géré par l’équipe RAMCES, est constitué de trois observatoires équipés de systèmes de mesure par chromatographie en phase gazeuse. Ces chromatographes en phase gazeuse sont situés à Gif-sur-Yvette, Trainou (forêt d’Orléans) et au sommet du Puy-de-Dôme. Ils ont été optimisés pour la mesure continue et de haute précision des principaux gaz à effet de serre : CO2, CH4, N2O et SF6. Ayant installé le GC au Puy-de-Dôme au cours de l’année 2010, je présenterai et analyserai en détail la série temporelle obtenue depuis son installation. Les mesures de gaz à effet de serre et des traceurs associés m’ont permis d’utiliser une approche multigaz pour contraindre leurs émissions à différentes échelles. A une échelle départementale et régionale, j’ai utilisé le 222Rn comme traceur de masses d’air pour quantifier les flux surfaciques mensuels de N2O à Gif-sur-Yvette et Trainou. Les émissions annuelles de N2O estimées à Gif-sur-Yvette et Trainou sont respectivement de 0.34/0.51 et 0.52 g(N2O) m-2 a-1. Le cycle saisonnier des émissions de N2O a permis de mettre en évidence l’impact de l’agriculture sur les émissions lors de l’apport d’engrais azoté dans les sols. J’ai mis en évidence une corrélation entre les flux de N2O annuels et les précipitations annuelles à Gif-sur-Yvette. A une échelle locale, j’ai utilisé le CO2 et ses isotopes mesurés lors d’une campagne réalisée pendant l’hiver 2010 à Paris, pour estimer les flux de CO2 parisien. Les mesures de 14CO2 atmosphérique m’ont permis de montrer que les flux de CO2 parisien en hiver sont essentiellement anthropiques (77 %) avec une contribution significative des émissions biogéniques (23 %). L’analyse du 13CO2 à quant à lui mis en évidence que les 77 % d’émission de CO2 d’origine fossile sont dues à 70 % à l’utilisation de gaz naturel et 30 % à l’utilisation de pétroleThe aim of my PhD is to use high precision measurements to evaluate greenhouse gas emissions at different scales in France, from local to regional. These measurements are made in the framework of the French greenhouse gases network operated by the RAMCES team. Three stations in France are equipped with gas chromatography measurement systems located at Gif-sur-Yvette, Trainou (Orléans forest) and on the summit of Puy-de-Dôme. They were optimized to measure continuously with high precision the main greenhouse gases: CO2 , CH4 , N2O and SF6. In July 2010, I have installed the gas chromatograph at Puy-de-Dôme and I present here the analysis of the past two years. I used an approach with measurements of greenhouse gases and related trace gases to constrain the emissions of greenhouse gases at different scales. At a regional scale, I used the 222Rn as an air mass tracer to quantify the monthly N2O fluxes at Gif-sur-Yvette and Trainou. Annual N2O emissions, derived from the atmospheric approach at Gif-sur-Yvette and Trainou are 0.34/0.51 and 0.52 g(N2O) m−2 a−1 , respectively. I found a clear seasonal cycle of N2O emissions with larger values in spring and summer, demonstrating the large contribution of agricultural emissions from fertilized soils. A correlation between annual N2O fluxes and annual precipitations was observed at Gif-sur-Yvette. At a local scale, I used carbon isotopes to estimate the fossil fuel CO2 contribution. Measurements were performed during a campaign in winter 2010 in Paris. Atmospheric 14 CO2 measurements showed that 77 % of total CO2 emissions are anthropogenic with a significant contribution of biospheric fluxes (23 %). Additionally, 13CO2 analysis showed that natural gas and fuel combustion amounted to 70 % and 30 %, respectively, of fossil fuel emissions
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Hofmann, Michael [Verfasser], Wolfgang [Akademischer Betreuer] Rotard, Matthias [Akademischer Betreuer] Richter, Wolfgang [Gutachter] Rotard, and Bernd [Gutachter] Hoffmann. "Entwicklung und Validierung eines Prüfverfahrens zur Bestimmung der Radon-222-Exhalationsrate aus Bauprodukten in VOC-Emissionsprüfkammern / Michael Hofmann ; Gutachter: Wolfgang Rotard, Bernd Hoffmann ; Wolfgang Rotard, Matthias Richter." Berlin : Technische Universität Berlin, 2018. http://d-nb.info/1168323711/34.
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Martinez, Jorge L. "Revealing groundwater-surface water exchanges and recharge processes with multiple tracers and hydrochemistry." Thesis, Queensland University of Technology, 2017. https://eprints.qut.edu.au/110526/1/Jorge_Martinez_Thesis.pdf.
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For effective resource management and to establish groundwater and surface water interactions, an innovative range of hydrological tracers and hydrochemical techniques have been applied to a total catchment in southeast Queensland. Stable and radioisotopes, carbon-14, radon-222, noble gases and SF6 were analyzed to characterize and quantify recharge sources. Statistical methods were also combined with inverse geochemical and three-dimensional geological modelling techniques, to develop regional conceptual models of groundwater movement and interaction with rivers.
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ALBERIGI, SIMONE. "Avaliação da exposição ao sup(222)Rn nas cavernas do Parque Estadual Turístico do Alto Ribeira (PETAR)." reponame:Repositório Institucional do IPEN, 2006. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11446.
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Dissertação (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
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Chevillard, Anne. "Etude à haute résolution du CO2 atmosphérique en Europe et en Sibérie : impact pour les bilans de carbone." Paris 6, 2001. http://www.theses.fr/2001PA066503.
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Mestanza, Muñoz Segundo Nilo. "Influência da ventilação na distribuição espacial do Rn-222 e seus produtos de decaimento em ambientes de convívio humano." [s.n.], 1996. http://repositorio.unicamp.br/jspui/handle/REPOSIP/278104.
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Orientador: Julio Cesar Hadler NetoDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin
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Resumo: Para determinar a influência da ventilação (fluxo direcionado de ar produzido por um ventilador) sobre a distribuição espacial do Rn-222 e seus produtos de decaimento (filhos) presentes em ambientes de convívio humano, obteve-se um conjunto de resultados experimentais, por meio da técnica de traços nucleares deixados por partículas alfa sobre detectores plásticos adequados (CR-39). A exposição destes detectores foi realizada num ambiente fechado, considerando a influência da ventilação para diferentes ângulos, velocidades e distâncias do ventilador. Nesta presente pesquisa, os resultados mostram que uma quantidade relativa de filhos do Rn-222 são retirados do ambiente pelos efeitos de ventilação e plateout. Apresentamos também estudos preliminares dos efeitos de borda nos detectores (CR-39), assim como a dependência da densidade dos traços como função da seção transversal do detector. Apresenta-se resultados de calibração do tempo de ataque químico em função do diâmetro dos traços. Fez-se também um modelo analítico que explica este fenômeno e que nos ajuda a compreender nossos resultados experimentais
Abstract: Not informed.
Mestrado
Física
Mestre em Física
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OLIVEIRA, JOSELENE de. "Determinacao dos niveis de radioatividade natural em aguas utilizadas para abastecimento publico no Estado de Sao Paulo .Vol. 2." reponame:Repositório Institucional do IPEN, 1998. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10699.
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Tese (Doutoramento) - IPEN Apendices
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP