Filters

Results

**1**-**10**of**118** Results

**1**-**10**of**118**. Search took:**0.018**secondsSort by: date | relevance |

AbstractAbstract

[en] By using the two-dimensional rigorous numerical solution of flow and convection-diffusion equations, the H

_{2}-HT separative performances of 77 K 'cryogenic-wall' thermal diffusion columns with 1,500 mm-fixed height and various radii of 1277 K hot and cold walls with feed rate being parametrically changed. Analyses revealed that the smaller radii columns are useful when feed flow rate is small while larger radii columns are useful when feed rate is large. 12 refs., 2 figs., 4 tabsPrimary Subject

Secondary Subject

Source

Annual meeting of the American Nuclear Society (ANS); Reno, NV (United States); 16-20 Jun 1996; CONF-9606116--

Record Type

Journal Article

Literature Type

Conference; Numerical Data

Journal

Country of publication

Publication YearPublication Year

Reference NumberReference Number

INIS VolumeINIS Volume

INIS IssueINIS Issue

AbstractAbstract

[en] Separative performances of 'cryogenic-wall' thermal diffusion column were analyzed concerning multi-component hydrogen isotope separation. Newly developed code could explain experimental data of 3-component hydrogen isotope separation in the case where the degree of separation is very large and that the third component is generated on the surface of the hot-wire. 23 refs., 7 figs

Primary Subject

Secondary Subject

Source

5. topical meeting on tritium technology in fission, fusion and isotopic applications; Ispra (Italy); 28 May - 3 Jun 1995; CONF-950506--

Record Type

Journal Article

Literature Type

Conference

Journal

Country of publication

Publication YearPublication Year

Reference NumberReference Number

INIS VolumeINIS Volume

INIS IssueINIS Issue

AbstractAbstract

[en] The supercritical fluid extraction (SFE) of heavy metals from acidic aqueous solution has attracted interest lately. In the present study, supercritical CO

_{2}was directly applied to lanthanide oxide as an extraction solvent. Lanthanide metals were extracted from lanthanide oxides (Nd_{2}O_{3}and Gd_{2}O_{3}) by using supercritical CO_{2}including tri-n-butylphosphate (TBP) and HNO_{3}complex. (author)Primary Subject

Record Type

Journal Article

Journal

Journal of Nuclear Science and Technology (Tokyo); ISSN 0022-3131; ; v. 35(7); p. 515-516

Country of publication

BUTYL PHOSPHATES, CARBON COMPOUNDS, CARBON OXIDES, CHALCOGENIDES, DISPERSIONS, ELEMENTS, ESTERS, EXTRACTION, GADOLINIUM COMPOUNDS, HOMOGENEOUS MIXTURES, HYDROGEN COMPOUNDS, INORGANIC ACIDS, INORGANIC COMPOUNDS, METALS, MIXTURES, NEODYMIUM COMPOUNDS, NITROGEN COMPOUNDS, ORGANIC COMPOUNDS, ORGANIC PHOSPHORUS COMPOUNDS, OXIDES, OXYGEN COMPOUNDS, PHOSPHORIC ACID ESTERS, RARE EARTH COMPOUNDS, RARE EARTHS, SEPARATION PROCESSES, SOLUTIONS, SOLVENT EXTRACTION, SPECTROSCOPY

Publication YearPublication Year

Reference NumberReference Number

INIS VolumeINIS Volume

INIS IssueINIS Issue

AbstractAbstract

[en] A series of experiments of Li isotope separation with displacement chromatography using a highly porous resin were performed under several flow rates from 0.1 to 20cm

^{3}/min. The flow rates were equivalent to a speed of a moving boundary of 0.0012 to 0.26cm/s. In evaluating Height Equivalent to a Theoretical Plate, HETP, as well as separation factor which indicate separative performance of chromatographic system, we developed a new relationship between HETP and a profile of^{6}Li mole fraction in the effluent with a mathematical model taking account of a mixing in a free space at the column outlet and in the fractionated samples. The values of separation factor and HETP of each experiment were simultaneously determined by the developed relation. The obtained values of the separation factor agreed with those evaluated by the frontal analysis method within the range of the experimental error. The obtained value of HETP increased with the flow rate in the range of the present experiments. It was suggested that diffusion of Li ion in particles as well as convective mixing of the solution played a significant role on determination of HETP. (author)Primary Subject

Record Type

Journal Article

Literature Type

Numerical Data

Journal

Journal of Nuclear Science and Technology (Tokyo); ISSN 0022-3131; ; v. 35(10); p. 692-696

Country of publication

Publication YearPublication Year

Reference NumberReference Number

INIS VolumeINIS Volume

INIS IssueINIS Issue

AbstractAbstract

[en] Interstage flows are analyzed for multicomponent separating cascades composed of elements with large separation factors. Based on the concept of cut relevant to each component, analysis is performed by extending the theory of binary component separation to multicomponent systems. Since the cut relevant to each component is expressed by heads and tails separation factors, interstage flows of each component are calculated through giving separation factors of all stages in the cascade. Interstage flows of isotope mixture are obtained by summing those of each component. A condition on separation factors to construct a ''matched abundance ratio cascade'' is also discussed in the case where the separation factor does not vary from stage to stage. (author)

Primary Subject

Record Type

Journal Article

Journal

Journal of Nuclear Science and Technology (Tokyo); v. 15(8); p. 580-584

Country of publication

Publication YearPublication Year

Reference NumberReference Number

INIS VolumeINIS Volume

INIS IssueINIS Issue

AbstractAbstract

[en] For a simplified model of separating elements where a total separation factor αβ is independent of values of cut θ (0<θ<1), an optimum cut θ

_{opt}in the sense that the cut makes a separative power δU maximum, was derived in terms of αβ, and a mole fraction x_{F}(0< x_{F}<1) of the component to be separated. When values of x_{F}is nearly equal to zero, the optimum cut θ_{opt}^{xF≅0}decreases and approaches to near 0, as the total separation factor becomes larger. On the contrary, when x_{F}is nearly equal to 1, the optimum cut θ_{opt}^{xF≅1}was found from calculation to be 1-θ_{opt}^{xF≅0}, and increases and approaches to near 1, as the total separation factor becomes larger. Moreover, in the case of x_{F}=0.5, the optimum cut is 0.5 regardless of αβ. Generally, the optimum cut θ_{opt}(x_{F}) was solved to be in the form of a linear interpolation of the boundary values, θ_{opt}^{xF≅0}and θ_{opt}^{xF≅1}. (author)Primary Subject

Record Type

Journal Article

Journal

Journal of Nuclear Science and Technology (Tokyo); ISSN 0022-3131; ; CODEN JNSTA; v. 28(9); p. 858-862

Country of publication

Publication YearPublication Year

Reference NumberReference Number

INIS VolumeINIS Volume

INIS IssueINIS Issue

AbstractAbstract

[en] Diffusion coefficients in 4-component mixture D

_{ij}^{(4)}were expressed explicitly in terms of binary diffusion coefficients and mole fractions by solving a ratio of determinants defined by Hirschfelder et al. The explicit expressions of D_{ij}^{(4)}were divided into two terms, a term due to the i-j pairs of attention and a term common to all the pairs out of the 4 components. The two terms of D_{ij}^{(4)}had extended structures similar to corresponding those of D_{ij}^{(3)}respectively. (author)Primary Subject

Record Type

Journal Article

Journal

Journal of Nuclear Science and Technology (Tokyo); ISSN 0022-3131; ; CODEN JNSTAX; v. 33(8); p. 650-653

Country of publication

Publication YearPublication Year

Reference NumberReference Number

INIS VolumeINIS Volume

INIS IssueINIS Issue

AbstractAbstract

[en] By making use of the isotope approximation; neglecting squares of relative mass differences among the isotopes, the authors derived analytically approximations to ordinary diffusion coefficients in a 3- and 4- component isotope mixture. Moreover, approximations to multi-component diffusion coefficients were given on the analogy of those to the 3- and 4-component coefficients, and these approximations were verified to satisfy constrains on the exact ordinary diffusion coefficients. For 4-component mixture of uranium hexafluoride isotopes,

^{234}UF_{6}-^{235}UF_{6}-^{236}UF_{6}-^{238}UF_{6}, composition dependences of the approximation were equal to those of the exact diffusion coefficients. In addition, relative errors between the exact and the approximations were less than 0.2% for 5-component mixture of krypton 80-82-83-84-86 isotopes. (author)Primary Subject

Record Type

Journal Article

Journal

Journal of Nuclear Science and Technology (Tokyo); ISSN 0022-3131; ; CODEN JNSTAX; v. 34(3); p. 318-324

Country of publication

ACTINIDE COMPOUNDS, ACTINIDE NUCLEI, ACTINIDES, ALPHA DECAY RADIOISOTOPES, CENTRIFUGES, CONCENTRATORS, ELEMENTS, EVEN-EVEN NUCLEI, EVEN-ODD NUCLEI, FLUORIDES, FLUORINE COMPOUNDS, HALIDES, HALOGEN COMPOUNDS, HEAVY ION DECAY RADIOISOTOPES, HEAVY NUCLEI, INTERNAL CONVERSION RADIOISOTOPES, ISOMERIC TRANSITION ISOTOPES, ISOTOPES, MAGNESIUM 28 DECAY RADIOISOTOPES, METALS, MINUTES LIVING RADIOISOTOPES, NEON 24 DECAY RADIOISOTOPES, NONMETALS, NUCLEI, RADIOISOTOPES, RARE GASES, SEPARATION PROCESSES, SPONTANEOUS FISSION RADIOISOTOPES, URANIUM COMPOUNDS, URANIUM ISOTOPES, YEARS LIVING RADIOISOTOPES

Publication YearPublication Year

Reference NumberReference Number

INIS VolumeINIS Volume

INIS IssueINIS Issue

AbstractAbstract

[en] Developing a computer code which solves concentration profiles simultaneously for vapor and liquid phases, we analyzed an effect of inner radius of wetted-wall column on separative performances of water distillation for H

_{2}O-HTO isotope separation. Results through the code were compared with experiments for H_{2}O-HTO wetted-wall water distillation under the total reflux condition with columns of 3 and 8 mm of inner radius R. Total separation factors of R = 3 mm were larger than those of R = 8 mm, and the fact was well predicted by a numerical analysis. The total separation factors for theoretically maximum vaporization rate constant k_{v,A}= 1.57 x 10^{4}cm/s gave a virtual its upper limit in the range of relatively large Reynolds number. (author)Primary Subject

Record Type

Journal Article

Journal

Journal of Nuclear Science and Technology (Tokyo); ISSN 0022-3131; ; v. 35(10); p. 723-727

Country of publication

Publication YearPublication Year

Reference NumberReference Number

INIS VolumeINIS Volume

INIS IssueINIS Issue

AbstractAbstract

[en] Heads and tails separation factors α, β are multiplicative measures of separation concerning the desired material's enriched and depleted streams. The function transforming multiplicative quantities to additive ones is a logarithm, and additive measures of separation concerning the desired material become ln α and ln (1/β) for the enriched and depleted streams, respectively. The additive measure of separating element is the weighted sum of them and the weights are selected to be portions of the desired material moving towards the enriched and depleted streams eta and average eta: eta ln α + average eta ln 1/β = α(β - 1)ln α - (α - 1)ln β/αβ - 1 = phi sub(b)(α, β), which equals to the separative power relevant to the desired material per unit flow rate. Similarly, the additive measure relevant to the undesired material becomes phi sub(a)(α, β) = β(α - 1)ln β - (β - 1)ln α/αβ - 1. Thus, the functions representing separative power phi sub(b) and phi sub(a) are additive measures of separating element relevant to the desired and undesired materials, respectively. Moreover, phi sub(b) and phi sub(a) are equivalent and distinguished only by the selection of the desired material in the two components in a binary mixture. (author)

Primary Subject

Record Type

Journal Article

Journal

Journal of Nuclear Science and Technology (Tokyo); ISSN 0022-3131; ; v. 16(11); p. 818-822

Country of publication

Publication YearPublication Year

Reference NumberReference Number

INIS VolumeINIS Volume

INIS IssueINIS Issue

1 | 2 | 3 | Next |