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Study of aerosol particle origin and dispersion by isotope ratio mass spectrometry / Atmosferos aerozolio dalelių kilmės ir sklaidos tyrimas stabilių izotopų masių spektrometrijos metoduGarbaras, Andrius 05 July 2011 (has links)
The development of industry, transport, agriculture and power engineering inevitably create problems related to the impact of generated waste on the environment as well as other undesirable processes. The atmosphere is the main component of the Earth’s climate system because changes occurring due to the human economic activity result in serious environmental impacts in all components of the ecosystem as well as the Earth’s climate self-regulation system is disturbed. The objective of this work was to investigate the origin, sources and formation of organic compounds and black carbon in atmospheric aerosol particles and to develop new research methods. To attain this objective the following tasks have been formulated: Development of the identification method for the aerosol origin and source by investigating the carbon isotope mass ratios, illustration of possibilities of the carbon isotope ratio method by identifying the aerosol particle origin during the air mass long-range transport at the Preila Environmental pollution research station, investigation of variation of the black carbon amount in aerosol particles in the diesel engine exhaust depending on the engine working parameters and fuel composition, investigation of the carbon isotope ratio variation in natural aerosol depending on the aerosol particle size distribution, determination of the partial contribution of natural and anthropogenic particles in aerosol by investigation of stable carbon and radiocarbon isotope... [to full text] / Žemės atmosfera yra svarbiausia klimato sferos dalis ir jautriausias antropogeninei taršai aplinkos sandas. Atmosferoje vykstantys procesai pakeičia ekosistemose per šimtmečius nusistovėjusius procesus – stebime įvairias globalinės klimato kaitos sukeltas pasekmes.
Mokslinė šio darbo idėja nukreipta į įvairiapusį atmosferos aerozolio dalelių savybių ir prigimties tyrimą bei tyrimo metodų plėtrą, pasiremiant naujausiomis aplinkotyros mokslo žiniomis, akcentuojant pastarojo dešimtmečio masių spektrometrijos pasiekimus. Šio darbo tikslas yra organinių medžiagų ir juodosios anglies atmosferos aerozolio dalelėse kilmės, aerozolio sudėties ir formavimosi tyrimai bei naujų tyrimo metodų plėtra. Darbe eksperimentiškai įrodyta, kad anglies izotopų santykis antropogeninės kilmės aerozolio dalelėse atitinka deginamo kuro izotopų santykį ir šis parametras tinka, identifikuojant aerozolio dalelių šaltinį. Šis izotopų santykis, kaip metodinė priemonė, buvo panaudotas tiriant įvairios prigimties aerozolio sudėtį, savybes ir kilmę. Tiriant aerozolio daleles tolimojoje oro pernašoje stebėjome elementinės anglies δ13C verčių kaitą akumuliacinėje modoje nuo -22,9 ‰ iki -26,3 ‰, organinės anglies δ13C = -28 ‰. Iš δ13C verčių nustatyta, jog elementinės anglies pirmtakai aerozolio dalelėse buvo degimo produktai, organinės anglies šaltinis – lakūs organiniai junginiai iš augalų. Vietinės kilmės dalelių, didesnių už 1 μm, stebėta karbonatinė komponentė. Apjungus masių ir izotopų santykių masių... [toliau žr. visą tekstą]
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Aerozolio dalelių kilmės ir sklaidos atmosferoje tyrimas stabilių izotopų masių spektrometrijos metodu / Study of aerosol particle origin and dispersion by isotope ratio mass spektrometryGarbaras, Andrius 05 July 2011 (has links)
Žemės atmosfera yra svarbiausia klimato sferos dalis ir jautriausias antropogeninei taršai aplinkos sandas. Atmosferoje vykstantys procesai pakeičia ekosistemose per šimtmečius nusistovėjusius procesus – stebime įvairias globalinės klimato kaitos sukeltas pasekmes.
Mokslinė šio darbo idėja nukreipta į įvairiapusį atmosferos aerozolio dalelių savybių ir prigimties tyrimą bei tyrimo metodų plėtrą, pasiremiant naujausiomis aplinkotyros mokslo žiniomis, akcentuojant pastarojo dešimtmečio masių spektrometrijos pasiekimus. Šio darbo tikslas yra organinių medžiagų ir juodosios anglies atmosferos aerozolio dalelėse kilmės, aerozolio sudėties ir formavimosi tyrimai bei naujų tyrimo metodų plėtra. Darbe eksperimentiškai įrodyta, kad anglies izotopų santykis antropogeninės kilmės aerozolio dalelėse atitinka deginamo kuro izotopų santykį ir šis parametras tinka, identifikuojant aerozolio dalelių šaltinį. Šis izotopų santykis, kaip metodinė priemonė, buvo panaudotas tiriant įvairios prigimties aerozolio sudėtį, savybes ir kilmę. Tiriant aerozolio daleles tolimojoje oro pernašoje stebėjome elementinės anglies δ13C verčių kaitą akumuliacinėje modoje nuo -22,9 ‰ iki -26,3 ‰, organinės anglies δ13C = -28 ‰. Iš δ13C verčių nustatyta, jog elementinės anglies pirmtakai aerozolio dalelėse buvo degimo produktai, organinės anglies šaltinis – lakūs organiniai junginiai iš augalų. Vietinės kilmės dalelių, didesnių už 1 μm, stebėta karbonatinė komponentė. Apjungus masių ir izotopų santykių masių... [toliau žr. visą tekstą] / The development of industry, transport, agriculture and power engineering inevitably create problems related to the impact of generated waste on the environment as well as other undesirable processes. The atmosphere is the main component of the Earth’s climate system because changes occurring due to the human economic activity result in serious environmental impacts in all components of the ecosystem as well as the Earth’s climate self-regulation system is disturbed. The objective of this work was to investigate the origin, sources and formation of organic compounds and black carbon in atmospheric aerosol particles and to develop new research methods. To attain this objective the following tasks have been formulated: Development of the identification method for the aerosol origin and source by investigating the carbon isotope mass ratios, illustration of possibilities of the carbon isotope ratio method by identifying the aerosol particle origin during the air mass long-range transport at the Preila Environmental pollution research station, investigation of variation of the black carbon amount in aerosol particles in the diesel engine exhaust depending on the engine working parameters and fuel composition, investigation of the carbon isotope ratio variation in natural aerosol depending on the aerosol particle size distribution, determination of the partial contribution of natural and anthropogenic particles in aerosol by investigation of stable carbon and radiocarbon isotope... [to full text]
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Effets de la carbonisation oxygénée sur le signal isotopique (δ13C) du bois : vers une dendroclimatologie isotopique sur charbons archéologiques / Oxygenated carbonization on wood isotopic sigal (δ13C) : aim to dendroclimatic reconstructions on archeological charcoalsBaton, Franck 08 November 2017 (has links)
Les charbons de bois trouvés en contexte archéologique permettent de reconstituer les couverts forestiers passés et les pratiques sylvicoles associées. Le δ13C de ces charbons a été utilisé pour des reconstructions paléoclimatiques, cependant ses variations peuvent aussi être dues à la carbonisation. Afin de mieux contraindre, à l’échelle du cerne, les variations du δ13C du bois dues à la carbonisation, des carbonisations ont été faites avec des échantillons de chêne cadicufoliés en conditions proches des foyers domestiques. Une diminution du δ13C après la carbonisation a été observée. Cet effet est très variable, notamment en fonction du compartiment du bois considéré (aubier, duramen, bois initial, bois final). Ces mesures de δ13C ont été complétées par celles du taux de carbone montrant qu’il ne varie pas parallèlement au δ13C. De ce fait l’utilisation, prônée par certains travaux, du taux de carbone pour évaluer les variations de d13C suite à la carbonisation n’est pas pertinente. Cependant, les variations cerne à cerne et intracerne du δ13C ne sont pas significativement affectées par la carbonisation, et des reconstructions climatiques à partir du δ13C de bois carbonisés paraissent donc envisageables. Afin de tester cette approche cerne à cerne, plusieurs charbons archéologiques issus du site Néolithique de Chalain, dont les paléoclimats étaient bien documentés, ont été échantillonnés. Cette approche a été couplée à des mesures dendro-anthracologiques (largeurs des cernes, proportion du bois final, rayon de courbure et proportion de vaisseaux avec des thylles) afin de mieux comprendre les variations de δ13C mesurées, et de tenter de les coupler aux pratiques sylvicoles. Les valeurs de δ13C sont en accord avec les paléoclimats déjà inférés et les variations intra-cerne, ou saisonnières, de δ13C révèlent que la période froide était caractérisée par des saisons plus contrastées. Les mesures dendro-anthracologiques ont permis, entre autres, de préciser les variations de δ13C entre les différents compartiments du bois et de proposer une interprétation concernant les variations des pratiques sylvicoles en lien avec le climat. En conclusion, la carbonisation oxygénée provoque un abaissement des valeurs de δ13C du bois mais n’empêche pas les reconstructions paléo-climatiques à partir de leurs variations, notamment saisonnières, mesurées sur des charbons archéologiques. / Archeological charcoals are used for reconstructing past woodland vegetation and the related historical forest practices. Charcoals δ13C are used for paleoclimate reconstructions. To better constrain the use of δ13C, we investigated the effect of oxygenated carbonization on ring scale δ13C variations in oak wood. Results showed a significant decrease of δ13C values after carbonization. This effect, however, is highly variable according to the wood compartment considered: heartwood, sapwood, earlywood, or latewood. Carbon content measurements do not exhibit the same variations along oxygenated carbonization as observed with δ13C. Therefore, the use of carbon content for evaluating carbonization effects on δ13C, which is proposed by some authors, is not appropriate. Interannual and seasonal δ13C variations, however, are not significantly affected by oxygenated carbonization. Thus, paleoclimate reconstruction from charcoals δ13C appears possible. To test both ring scale variations, archeological charcoals were sampled from a climatically well documented Neolithic site of Chalain. Several dendro-anthracological parameters (latewood proportion, duraminization, charcoal-pith distance estimation) were characterized for a better understanding of δ13C variations, in order to integrate historical woodland practices and the climatic interpretations. Charcoal tree-rings exhibited width and δ13C significantly different between the two studied periods, in agreement with previously inferred climatic difference. Intra-ring δ13C suggested that the cool and moist climatic period also corresponded to higher seasonal contrast than the dryer climatic period. Dendro-anthracological parameters allow better understanding of δ13C variations between wood compartments and provide information on past woodland exploitations. To conclude, oxygenated carbonizations induce a decrease in wood δ13C values, but do not prevent the paleoclimate interpretations of δ13C variations in archeological charcoals.
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Seasonal Variation of Chemical Hydrography in the Southern Penghu ChannelLin, Hsin-chi 26 June 2003 (has links)
Abstract
The Penghu Channel (PHC), situated in the southeastern Taiwan Strait (TS), is the major conduit for the South China Sea water (SCSW) and Kuroshio subsurface water flowing into the TS. However, the previous studies in this area were largely focused on the aspects of physical oceanography, with scant attention to the chemical hydrography is poorly studied, and therefore little understood. In order to better understand the seasonal variations of chemical hydrography in the southern PHC, we conducted a systematic survey of chemical hydrography aboard R/V Ocean Research III during cruises in January, March, July and October 2001 as well as March 2002.
The water above 200m in the southern PHC is characteristic of salinity and temperature between those of SCSW and Kuroshio water (KW), suggesting it is mixing between these two waters. Nonetheless, the salinity and temperature below 200m are dominated by the SCSW. The relative amount of SCSW and KW flowing into the PHC has varied seasonally and annually. During the transition period of monsoon, KW was more than SCSW, but SCSW had a larger quantity during the northeast and southwest monsoon.
The slope of the regression line between the d13CDIC and PO4-3 (0-100m, -0.55; below 100m, -0.30) indicates that the distributions of d13CDIC and PO4-3 in the study area may be controlled by the effect of air-sea exchange or the mixing of different water masses or both.
In addition, to evaluate the overall error in d13CDIC analysis, we have checked carefully whether the different storage bottles, the various duration of storage, and different amount of saturated HgCl2 solution added in the water samples would produce uncertainty on the d13CDIC analysis. Our results show no significant discrepancy among these the different treatments, suggesting that the water samples can be stored without measurable d13CDIC change at least for 3 months.
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Origin and Geochemistry of Modern Bahamian OoidsDuguid, SARAH 27 January 2009 (has links)
The Bahamian Archipelago is one of the few locations in the world where ooid formation is actively occurring. Ooid cortices from six locations in the region were incrementally dissolved and analyzed for 14C, δ18O, δ13C, Mg/Ca and Sr/Ca ratios. Ooids were examined under SEM after each step in the incremental analyses to characterize the nature of dissolution. Radiocarbon dating indicates that surface ooids began forming across the Archipelago between 1000 and 2800 yr BP and continue to form today.
The ooids have the same pattern of microboring alteration across the region. The surface and outer cortex of the ooids are punctuated with unfilled microborings, whereas the inner cortex contains two morphologies of aragonite cement filling the microborings. The two morphologies of cement form in association with two different species of cyanobacteria, one is Solentia sp. the other is interpreted to be Hyella sp..
The chemistry of ooids from across the region is remarkably similar. δ18O and δ13C values for all samples vary directly, having a slope of approximately 1. The outer cortex has low δ18O and δ13C values of -3.4‰ and 0.2‰ respectively, whereas the δ18O and δ13C values of the inner cortex are high with values of 1.9‰ and 6.8‰ respectively. The presence of aragonite cement in microborings in the inner cortex increases the overall isotopic composition of both oxygen and carbon in the ooid, causing it to appear close to equilibrium with seawater. The isotopic variation in δ18O and δ13C within the cortex can be characterized as a mixing line between the low values in the unaltered ooid laminae and the aragonite cement in the microborings.
The most exterior portion of the ooid has very high Mg/Ca values and is interpreted as an amorphous calcium carbonate (ACC) coating. There are two other phases in the cortex, both being aragonite. The outer cortex has a higher Mg/Ca ratio and lower Sr/Ca ratio than the inner cortex. This difference in chemistry is a result of the presence of aragonite cement in the inner cortex.
Stable isotopic and trace element results coupled with SEM investigations indicate that microbes do not play a role in ooid formation, but instead alter the texture and chemistry of ooids after they have formed. This alteration occurs throughout the entire shoal region. A new model of ooid formation is proposed whereby a veneer of ACC precipitates on an ooid while it is at the sediment-water interface (the active phase). This veneer of ACC later recrystallizes to aragonite needles, possibly nucleating on organic material and a new cortex layer is formed. Observations from this study lead to a deeper understanding of the chemical processes involved in ooid genesis, which allows for a better understanding of paleoenvironments hosting ooid formation. / Thesis (Master, Geological Sciences & Geological Engineering) -- Queen's University, 2009-01-27 13:29:42.765
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Contribution of Nitrogen Fixation to Planktonic Food Webs North of AustraliaDrexel, Jan Peter 16 November 2007 (has links)
Nitrogen fixation is no longer considered to be a minor factor of the nitrogen cycle in oceanic ecosystems. Recent geochemical and biological efforts have led to a significant increase in the estimated input of nitrogen to marine ecosystems by biological fixation, while molecular studies have increased our knowledge of the number and diversity of nitrogen fixers known to be active in the ocean. Although Trichodesmium spp. have long been viewed as the primary marine nitrogen fixers, recent efforts have shown that various members of the picoplankton community are also actively involved in nitrogen fixation. The relative abundance of different nitrogen fixers is an important ecosystem parameter since nitrogen fixers may differ significantly in their physiology, life history and ecology. Here we combine rate measurements and stable isotope natural abundance measurements to constrain the impact of N2 fixation in the waters north of Australia. Samples were collected in the Coral, Arafura, and East Timor Seas, thus spanning three distinct hydrographic regions. Our data show that Trichodesmium has a significant influence on the stable nitrogen isotope ratios of particulate and zooplankton biomass and suggest that Trichodesmium is a significant source of nitrogen for the pelagic ecosystem. Based on stable carbon isotope ratios, it is also likely that the pathways are indirect and nitrogen fixed by Trichodesmium enters the higher trophic levels via decomposition as dissolved organic and inorganic nitrogen. Picocyanobacteria showed high diazotrophic activity at some stations, but unlike Trichodesmium, their N2 fixation rate was not reflected in the stable N isotope ratios of particulate and zooplankton biomass. Our results suggest an important N contribution to biomass by diazotrophs in the Coral Sea, Arafura Sea and East Timor Sea.
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Reconstruction and Analysis of Native American land use during the late HoloceneWhite, David M. 29 September 2007 (has links)
No description available.
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Comparative reproductive strategies between long-tailed ducks and king eiders at Karrak Lake, Nunavut: use of energy resources during the nesting seasonLawson, Shona Louise 21 September 2006
Energy demands can be particularly high in arctic-nesting birds that face harsh, unpredictable conditions during the breeding season. Consequences of these demands, particularly energy-partitioning during egg laying and incubation, are fundamentally important for arctic nesters. This study investigated differences in breeding strategies between Long-tailed Duck (<i>Clangula hyemalis</i>) and King Eider (<i>Somateria spectabilis</i>) in the central Canadian arctic. The focus was on ecological variables and influences of variation in nutrient resources used during incubation and egg production. Research was done at Karrak Lake, Nunavut, where both species nest sympatrically at relatively high densities, permitting comparative research about breeding strategies.<p>This study used stable-carbon (d13C) and nitrogen (d15N) isotope analysis to investigate origins and allocation of endogenous (stored) and exogenous (external) nutrients used in egg production. Remote temperature sensors were placed in nests to estimate and compare incubation rhythms and gain insight into capital and income incubating strategies of both species. Results suggest that breeding Long-tailed Ducks and King Eiders used a mixed breeding strategy, that is they relied on both exogenous and endogenous resources for reproduction. Close correspondence between d13C and d15N values of egg components and potential diet items indicated that King Eiders allocated exogenous nutrients for egg production (albumen 98.1%, yolk protein 96.8%, whole yolk 98.4%, and yolk lipids 84%). Female King Eiders relied on endogenous nutrients for incubation, as evidenced by high incubation constancy (96%). Conversely, the range of d13C values in components of Long-tailed Duck eggs and d13C values of diet items suggested that although some females allocated endogenous reserves for egg production, most females allocated exogenous resources for egg production (albumen 98.5%, yolk protein 78.3%, whole yolk 84.9%, and yolk lipids 38.3%). Long-tailed Duck females had an 84% incubation constancy, suggesting less reliance on endogenous nutrients for incubation than was estimated for female King Eiders. Knowledge about the relative importance of endogenous reserves and exogenous nutrients for egg production and incubation may help direct management decisions to specific winter/staging and or breeding areas used by King Eiders and Long-tailed Ducks.
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Comparative reproductive strategies between long-tailed ducks and king eiders at Karrak Lake, Nunavut: use of energy resources during the nesting seasonLawson, Shona Louise 21 September 2006 (has links)
Energy demands can be particularly high in arctic-nesting birds that face harsh, unpredictable conditions during the breeding season. Consequences of these demands, particularly energy-partitioning during egg laying and incubation, are fundamentally important for arctic nesters. This study investigated differences in breeding strategies between Long-tailed Duck (<i>Clangula hyemalis</i>) and King Eider (<i>Somateria spectabilis</i>) in the central Canadian arctic. The focus was on ecological variables and influences of variation in nutrient resources used during incubation and egg production. Research was done at Karrak Lake, Nunavut, where both species nest sympatrically at relatively high densities, permitting comparative research about breeding strategies.<p>This study used stable-carbon (d13C) and nitrogen (d15N) isotope analysis to investigate origins and allocation of endogenous (stored) and exogenous (external) nutrients used in egg production. Remote temperature sensors were placed in nests to estimate and compare incubation rhythms and gain insight into capital and income incubating strategies of both species. Results suggest that breeding Long-tailed Ducks and King Eiders used a mixed breeding strategy, that is they relied on both exogenous and endogenous resources for reproduction. Close correspondence between d13C and d15N values of egg components and potential diet items indicated that King Eiders allocated exogenous nutrients for egg production (albumen 98.1%, yolk protein 96.8%, whole yolk 98.4%, and yolk lipids 84%). Female King Eiders relied on endogenous nutrients for incubation, as evidenced by high incubation constancy (96%). Conversely, the range of d13C values in components of Long-tailed Duck eggs and d13C values of diet items suggested that although some females allocated endogenous reserves for egg production, most females allocated exogenous resources for egg production (albumen 98.5%, yolk protein 78.3%, whole yolk 84.9%, and yolk lipids 38.3%). Long-tailed Duck females had an 84% incubation constancy, suggesting less reliance on endogenous nutrients for incubation than was estimated for female King Eiders. Knowledge about the relative importance of endogenous reserves and exogenous nutrients for egg production and incubation may help direct management decisions to specific winter/staging and or breeding areas used by King Eiders and Long-tailed Ducks.
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Réservoirs fluides et transferts en contexte d'exhumation orogénique : implications sur la position structurale des minéralisations Cu-Pb-Zn-Fe-Ag dans la région Lavrion-Eubée (Grèce) / Stuctural position and geochemistry of fluids associated with Cu-Pb-Zn-Fe-Ag deposits in the Lavrion-Evia area (Greece)Scheffer, Christophe 07 December 2016 (has links)
Cette thèse est centrée sur la ceinture orogénique Attico-Cycladique formée durant l'orogénèse Alpine. Par une approche multi-méthodes et multi-échelles combinant géologie structurale, pétrographie, thermobarométrie des assemblages minéraux, géochimie élémentaire et isotopique, et données PVTX des inclusions fluides associées, ce travail vise à caractériser et comprendre les relations entre circulations fluides, interactions fluides/roches, déformation, et mobilisation-transport-dépôt des métaux. Les marbres et schistes de la péninsule du Lavrion et de l'île d'Eubée témoignent d'une évolution orogénique complexe marquée par une phase d'enfouissement à l'Eocène suivie par deux phases d'exhumation successives syn-et post-orogéniques. Les minéralisations de type Cu-Pb-Zn-Fe-Ag de la région du Lavrion sont synchrones de l’activation du détachement post-orogénique et de la mise en place de plutons de granodiorite. Leurs positions structurales témoignent d’un piégeage depuis un régime de déformation ductile jusqu'à fragile. Les minéralisations mises en place durant le régime de déformation ductile à ductile-fragile (skarn et remplacement de carbonate) sont associées à la décarbonatation des niveaux de marbres et à la circulation des fluides magmatiques. L'exhumation progressive de la racine orogénique se traduit par la transition des roches depuis une déformation ductile vers un régime fragile associé à l’ouverture du système aux fluides de surface et notamment aux fluides météoriques. Cette circulation est responsable d’une remobilisation des métaux des minéralisations primaires permettant alors une seconde phase de précipitation dans un régime cassant (veines épithermales) / This thesis is focused on the Attico-Cycladic orogenic wedge formed during the Alpine orogeny. From a multi-method and multi-scale approach using structural geology, petrography, mineral thermobarometry, element and isotope geochemistry, and PVTX data of associated fluid inclusions, this study deciphers the relationships between fluid circulation, fluid-rock interactions and mobilisation-transport-deposits of metals. Marbles and schists from the Evia Island and the Lavrion peninsula testify to a complex orogenic history marked by an Eocene burial phase followed by syn- and post-orogenic exhumation. Cu-Pb-Zn-Fe-Ag mineralisations from the Lavrion area are synchronous with the formation of the low-angle post-orogenic detachment and the emplacement of granodioritic magmas. The structural position of the deposits attests of an emplacement during ductile to brittle deformation conditions. Deposits associated with ductile to ductile-brittle deformation (skarn, carbonate replacement) are related to a marble decarbonation and magmatic fluid circulation. The progressive exhumation of the orogenic wedge allows the transition toward brittle conditions and opens the system to surficial meteoritic fluids. This meteoritic fluid circulation is responsible to remobilisation of metals from primary deposits allowing thus a second phase of deposition in a pure brittle deformation (epithermal veins)
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