Dopage Selectif De La Glace Monocristalline Avec De L'Helium Et Du Neon

Kahane, Ahuvia; Klinger, J.; Philippe, Marc

doi:10.1016/0038-1098(69)90469-4

Cited by 34 publications

(27 citation statements)

References 2 publications

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“…While Ar and N, concentrations would simply increase due to freezing with no bubble formation, Ne would still be removed from the system owing to its solubility in the ice. By using the above scenario and calculating the volume of ice formed from the additional freezing with no bubble formation, we estimate that the Ne concentration in the residual water should be -33 + 2% of solubility equilibrium (using the solubility values of Kahane et al 1969), which is in excellent agreement with our observations (Table 3, Fig. 2A).…”

Section: Nitrogensupporting

confidence: 83%

“…2A,B). We suggest that the latter is the result of the large partitioning of the sparingly soluble gases He and Ne between bubbles at the ice-water interface, coupled with the solubility of these gases within the ice itself (Kahane et al 1969;Namoit and Bukhgalter 1965). Ifi a relatively closed, three-phase system consisting of ice, air bubbles in the ice, and water, the water will become undersaturated in He and Ne with respect to solubility equilibrium with the atmosphere if it is not adequately ventilated.…”

Section: Resultsmentioning

confidence: 96%

“…While the values of the solubility of He in ice that are reported in these two references are in good agreement, the values for the solubility of Ne in ice disagree. Kahane et al (1969) reported that, like He, the ratio of the solubility of Ne in ice to that in water Table 1. Equilibrium partition coefficients for He, Ne, and Ar in a three-phase system.…”

Section: Resultsmentioning

confidence: 97%

“…Equilibrium partition coefficients for He, Ne, and Ar in a three-phase system. Partition coefficients were calculated using the Bunsen solubility coefficients of Weiss (1970Weiss ( , 1971 Kahane et al (1969). t Calculated using the solubility values of Ne in ice from Namoit and Bukhgalter (1965).…”

Section: Resultsmentioning

confidence: 99%

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Dissolved gas dynamics in perennially ice‐covered Lake Fryxell, Antarctica

Hood

Howes

Jenkins

1998

Limnology & Oceanography

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We use the concentrations of noble gases (He, Ne, and Ar), helium isotopes, and tritium to characterize the mechanisms and rates of ventilation for Lake Fryxell, Antarctica, as well as the physical processes controlling dissolved gases. The upper oxic zone is ventilated on timescales of several decades. The anoxic bottom waters are weakly ventilated, with a turnover time of -3,800 years. In the upper euphotic zone, helium and neon are greatly undersaturated with respect to solubility equilibrium with the atmosphere, whereas argon is greatly supersaturated owing to equilibrium partitioning of the gases between ice, water, and air inclusions in the ice. In the bottom waters, the inert dissolved gas concentrations'may be remnants of a near-desiccation event that occurred -2,000 years I~.P., consistent with current paleoclimatic the&es.

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Section: Nitrogensupporting

confidence: 83%

Section: Resultsmentioning

confidence: 96%

Section: Resultsmentioning

confidence: 97%

Section: Resultsmentioning

confidence: 99%

See 2 more Smart Citations

Dissolved gas dynamics in perennially ice‐covered Lake Fryxell, Antarctica

Hood

Howes

Jenkins

1998

Limnology & Oceanography

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“…It has been recognized for some time that the noble gases, He and Ne, and possibly H2, should be soluble in the ice matrix, whereas gases with larger atomic radii are rejected from the matrix as ice freezes (Namoit and Bukhgalter, 1965;Kahane et al, 1969). The solubility of gases in liquids can be described by statistical mechanics (Pollack, 1991) and scaled particle theory (Pierotti, 1976), although several of the processes of solubility are not yet fully understood (Benson and Krause, 1980).…”

Section: The Noble Gases As Tracers Of the Interactions Between Ice Amentioning

confidence: 99%

Characterization of air-sea gas exchange processes and dissolved gas/ice interactions using noble gasses

Hood¹

1997

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In order to constrain the processes controlling the cycles of biogeochemically important gases such as 02 and CO 2 , and thereby infer rates of biological activity in the upper ocean or the uptake of radiatively important "greenhouse" gases, the noble gases are used to characterize and quantify the physical processes affecting the dissolved gases in aquatic environments. The processes of vertical mixing, gas exchange, air injection, and radiative heating are investigated using a 2 year time-series of the noble gases, temperature, and meteorological data from Station S near Bermuda, coupled with a 1-dimensional upper ocean mixing model to simulate the physical processes in the upper ocean. The rate of vertical mixing that best simulates the thermal cycle is 1.1 ±0.1 x10 4 m s1. The gas exchange rate required to simulate the data is consistent with the formulation of Wanninkhof (1992) to ± 40%, while the formulation of Liss and Merlivat (1986) must be increased by a factor of 1.7± 0.6. The air injection rate is consistent with the formulation of Monahan and Torgersen (1991) using an air entrainment velocity of 3±1 cm s1. Gas flux from bubbles is dominated on yearly time-scales by larger bubbles that do not dissolve completely, while the bubble flux is dominated by complete dissolution of bubbles in the winter at Bermuda. In order to obtain a high-frequency time-series of the noble gases to better parameterize the gas flux from bubbles, a moorable, sequential noble gas sampler was developed. Preliminary results indicate that the sampler is capable of obtaining the necessary data. Dissolved gas concentrations can be significantly modified by ice formation and melting, and due to the solubility of He and Ne in ice, the noble gases are shown to be unique tracers of these interactions. A three-phase equilibrium partitioning model was constructed to quantify these interactions in perennially ice-covered Lake Fryxell, and this work was extended to oceanic environments. Preliminary surveys indicate that the noble gases may provide useful and unique information about interactions between water and ice.

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Gas Hydrate Formation by Methane‐Helium Mixtures

et al. 2011

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Equilibrium conditions for gas hydrates formed by methane-helium mixtures with helium concentrations of 31.9, 63.9, and 74.6 mol.-% have been studied at pressures up to 160 bar. The data obtained indicate that in the studied range of helium concentrations and pressures helium hardly contributes to the stability of the gas hydrate formed. The shift of equilibrium conditions to lower temperatures and higher pressures is caused by dilution of methane in the gas phase and, consequently, the decrease in the chemical potential of methane in the gas phase. IntroductionGas hydrates are inclusion compounds in which the host framework is composed of hydrogen-bonded water molecules. Guest molecules occupy cavities of this framework. Under normal conditions the guest species are gases or volatile liquids [1]. At comparatively low pressures three structural types of gas hydrates are most abundant, namely, the cubic structures I and II, and structure H (or hexagonal structure III) [1][2][3][4]. Gas hydrate studies are highly topical due to the following reasons: (i) substantial deposits of natural gas hydrates in the earth's crust; (ii) necessity of prevention of hydrate formation in the course of gas and oil production; (iii) possibility of storage and transportation of natural gas in the form of gas hydrates, and (iv) separation of gas mixtures through hydrate formation [1,[3][4][5][6][7][8][9].The gas hydrate method of gas mixture separation is based on the differences in the stability of gas hydrates formed by different hydrate formers. The hydrate phase is enriched with the component forming a more stable hydrate [10][11][12][13][14][15]. It is known that helium, hydrogen, and neon do not form gas hydrates at relatively low pressure (several hundreds of bar). Due to this reason, the usage of gas hydrates appears to be promising for separating the above light gases from gas mixtures, in particular for concentrating helium when obtaining it from natural gas. The development of gas hydrate methods for separation of gas mixtures requires data of the phase diagrams of the systems gas mixture/water. For the hydrate-forming systems involving hydrogen, a relatively large amount of information has been accumulated, e.g., in [10,[16][17][18][19][20][21][22][23][24]. At the same time, only few papers have been published concerning the systems with helium [25][26][27][28][29]. In [26,27], helium hydrates were studied at very high pressures, and [29] deals with calculations. Insufficient experimental information concerning the role of helium in gas hydrate formation in the practically interesting range of pressures stimulated our interest for this subject. In the present communication, the results on the equilibrium conditions for gas hydrates formed by a mixture of methane and helium as well as informations concerning helium concentration in the hydrates formed are described. Materials and MethodsThe curves of hydrate decomposition were studied with the apparatus and experimental procedure described in [30]. The maximum possible err...

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Dopage Selectif De La Glace Monocristalline Avec De L'Helium Et Du Neon

Cited by 34 publications

References 2 publications

Dissolved gas dynamics in perennially ice‐covered Lake Fryxell, Antarctica

Dissolved gas dynamics in perennially ice‐covered Lake Fryxell, Antarctica

Characterization of air-sea gas exchange processes and dissolved gas/ice interactions using noble gasses

Gas Hydrate Formation by Methane‐Helium Mixtures

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