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Hanssens, A.
CEA Centre d'Etudes de la Vallee du Rhone, 30 - Marcoule (France). Dept. des Procedes de Retraitement1991
CEA Centre d'Etudes de la Vallee du Rhone, 30 - Marcoule (France). Dept. des Procedes de Retraitement1991
AbstractAbstract
[en] Pulse columns have been used for more than 20 years, for uranium extraction in nitric solutions by TBP knowledge acquired at the CEA leads to the development of large diameter pulse columns for processing of large quantities outside The nuclear domains
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Source
1991; 34 p; Summer School of Liquid Extraction; Toulouse (France); 8-11 Jul 1991
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AbstractAbstract
[en] A new solvent extraction system and a column extraction technique based on a continuous flow analysis approach are described. First copper and uranium solutions are extracted using a system based on a solvent extraction flow injection analysis (SEFIA). Due to the limited preconcentration factors which did not provide the sensitivity needed to determine uranium in the region of 50 ppB, a new extraction system is developed, Closed Loop Solvent Extraction System, (CLSES). The method is based on the continuous extraction of the analyte in a small volume of organic phase circulating within a closed loop. In this way, the aqueous stream enters the extraction coil and exits to waste, while the organic phase is circulated following phase separation. Equations relating the preconcentration factors to the extraction parameters are derived and verified. Two unique advantage of the present system compared to other continuous flow extraction methods are obtained. The first is the high preconcentration factors that can be easily reached. The second is the ability to include a back extraction step within the same manifold to remove interferences. Using micro-columns packed with silica for on-line preconcentration in flame and graphite furnace atomic absorption spectrometry (FAAS, GFAAS), Cu2+ and Pb2+ were determined at the ppB concentration level. Microcolumns of silica gel are used to adsorb trace-free metal ions, and microcolumns of C18 bonded silica gel are used to adsorb neutral metal chelates. Negatively charged forms of copper do not retain on the columns. A method was developed to combine the advantages of on-line preconcentration systems and the high sensitivity of GFAAS
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1987; 165 p; University Microfilms Order No. 88-02,183; Thesis (Ph. D.).
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Report
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Thesis/Dissertation
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AbstractAbstract
[en] Published in summary form only
Source
13. Annual Meeting of the Brazilian Chemical Society; Caxambu, MG (Brazil); 23-26 May 1990
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Journal Article
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Sparks, R.E.; Edwards, R.V.; Dybbs, A.
Case Western Reserve Univ., Cleveland, Ohio (USA)
Case Western Reserve Univ., Cleveland, Ohio (USA)
AbstractAbstract
No abstract available
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nd; 60 p
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Weston, A.M.; Lee, E.L.
Lawrence Livermore National Lab., CA (USA)1983
Lawrence Livermore National Lab., CA (USA)1983
AbstractAbstract
[en] A structural compaction model is used to correlate NSWC quasi-static compaction data on porous beds of six (6) different materials, i.e., four (4) ball powders, melamine, and Teflon. Initial densities of the porous beds ranged from 44 percent solid theoretical maximum density (TMD) to 70 percent TMD. Maximum compacted densities were about 90 percent TMD except for Teflon which was compacted to approximately 98 percent TMD. Pressures calculated by the model, plotted as a function of percent TMD, agree well with the NSWC data
Source
6 Apr 1983; 20 p; Available from NTIS, PC A02/MF A01 as DE83012043
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Report
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Sampaio, E.A.L.; Domingues, M.L.F.; Alleluia, I.B. de
Proceedings of 2. International Environmental Chemistry Congress1987
Proceedings of 2. International Environmental Chemistry Congress1987
AbstractAbstract
[en] Published in summary form only
Original Title
Absorcao de iodo elementar em solucoes aquosas
Primary Subject
Source
Tabacof, G.; Rocha, N.V.P. da; Borges, S.B. (and others); Bahia Univ., Salvador, BA (Brazil); 144 p; 1987; p. 75; 2. International Environmental Chemistry Congress; Salvador, BA (Brazil); 16-18 Sep 1987; Available from the Library of the Comissao Nacional de Energia Nuclear, RJ, Brazil
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Miscellaneous
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Conference
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Malloy, J.; Potekhen, D.
Proceedings of the 24th intersociety energy conversion engineering conference. Volume 21989
Proceedings of the 24th intersociety energy conversion engineering conference. Volume 21989
AbstractAbstract
[en] This paper examines the use of a particle bed reactor nuclear engine for direct thrust in a spacecraft based on the NASA/TRW orbital maneuvering vehicle (OMV). It presents the conceptual design of a 500 lb thrust engine that matches critical design features of the existing OMV bi-propellant propulsion system. This application contrasts with the usual tendency to consider a nuclear heat source either for high thrust direct propulsion or as a power source for electric propulsion. A nuclear propulsion module adapted to the OMV could potentially accomplish several Department of Defense missions, such as multiple round trips from a space-based support platform at 280 NM to service a constellation of satellites orbiting at 1800 NM
Primary Subject
Source
Anon; Conversion technologies and space nuclear reactor systems; 2950 p; 1989; p. 1209-1214; IEEE Service Center; Piscataway, NJ (USA); 24. intersociety energy conversion engineering conference; Arlington, VA (USA); 6-11 Aug 1989; CONF-890815--; IEEE Service Center, 445 Hoes Ln., Piscataway, NJ 08854 (USA)
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Book
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Conference
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Smith, D. B.; Rawson, D. S.
Tritium in the Physical and Biological Sciences. V. 1. Proceedings of a Symposium1962
Tritium in the Physical and Biological Sciences. V. 1. Proceedings of a Symposium1962
AbstractAbstract
[en] A method of tritium reconcentration by the total reflux distillation of water under reduced pressure using random-packed columns was investigated. For the maximum removal of tritium from a one liter reservoir, operating periods of several weeks were required. For this a fully automatic fractionating system incorporating an apparatus for taking samples automatically under reduced pressure was developed to enable the distillation to proceed with the minimum of manual adjustment. To reduce the possibility of flooding at the base of the column due to gravity settling of the packing over long periods of time, a novel design feature was incorporated at the junction of the column and the reflux meter. The performance of several commercially available column packings was investigated in an aqueous environment. Details of the packing pre-treatment to inhibit maldistribution in a liquid of high surface tension are given and enrichment factors calculated. A low H.E.T.P. (height equivalent to a theoretical plate) of about 0.8 in has been achieved with pre-treated phosphor-bronze gauze rings in an aqueous environment. With a reservoir-to-boiler volume ratio of the order of 7 : 1, a maximum of 98% of the tritium in the reservoir was removed in 28 d continuous distillation with a throughput of 100 ml/h. This indicated a tritium reconcentration factor of 6.3. By increasing the throughput to 140 ml/h, 92% of the tritium was extracted in 11 d. The reproducibility of the reconcentration factor with time was, however, shown to vary, and the reasons for this are discussed in the paper. (author)
[fr]
Les auteurs ont etudie une methode de reconcentration du tritium par distillation de l'eau sous reflux total et a pression reduite, avec utilisation de colonnes dont le garnissage etait dispose au hasard. Pour extraire un maximum de tritium dans un reservoir d'un litre, il a fallu operer pendant plusieurs semaines. A cet effet, les auteurs ont mis au point un appareil de fractionnement entierement automatique muni d'un dispositif automatique de prise d'echantillons a pression reduite, afin que la distillation puisse se poursuivre avec un minimum d'ajustement manuel. Pour reduire la possibilite d'obturation par le liquide a la base de la colonne par suite du tassement naturel du remplissage au cours de periodes prolongees, on a introduit un dispositif de conception nouvelle au point de jonction de la colonne et du compteur a reflux. Les auteurs ont etudie en milieu aqueux l'efficacite relative dans les colonnes de plusieurs garnissages que l'on trouve sur le marche. Ils donnent des details du traitement prealable auquel on soumet les garnissages pour empecher une distribution defavorable dans un liquide de forte tension superficielle, ainsi que les resultats du calcul des facteurs d'enrichissement. En utilisant en milieu aqueux des anneaux en toile de bronze phosphoreux ayant subi un traitement prealable, ils ont pu obtenir une faible H.E. P. T. (hauteur equivalante a un plateau theorique) d'environ 0,8 pouce. Le rapport entre le volume du reservoir et celui de la chaudiere etant de 7 a 1, ils ont extrait un maximum de 98% du tritium du reservoir par distillation continue pendant 28 jours avec un debit de 100 ml/h, ce qui correspond a un facteur de reconcentration du tritium de 6,3. En portant le debit a 140 ml/h, ils ont pu extraire 92% du tritium en 11 jours. Les auteurs ont cependant constate qu'en operant dans les memes conditions d'experimentation il n'est pas toujours possible d'obtenir le meme facteur de reconcentration; ils examinent dans le memoire les causes de ce phenomene. (author)[es]
Los autores estudian un metodo de reconcentracion del tritio por destilacion de agua a reflujo total y presion reducida, utilizando columnas de relleno no ordenado. Para extraer la maxima cantidad de tritio de un deposito de un litro, fueron precisas varias semanas de funcionamiento. Para ello se ha ideado un sistema de fraccionamiento totalmente automatico, provisto de un dispositivo para tomar muestras a presion reducida, con objeto de poder efectuar la destilacion con el minimo de ajustes manuales. A fin de evitar la posibilidad de obturacion por el liquido en la base de la columna, debido al asentamiento del relleno por gravedad cuando este se utiliza durante mucho tiempo, se ha introducido un dispositivo de nuevo tipo en la union de la columna y del contador de reflujo. Los autores estudian el rendimiento en medio acuoso de algunos productos de relleno, de venta en el comercio. Asimismo, describen detalladamente el tratamiento previo del relleno para evitar la distribucion desfavorable en un liquido de tension superficial elevada, y calculan los factores de enriquecimiento. Utilizando en un medio acuoso anillos de malla de bronce fosforado, previamente tratados, se ha logrado reducir la altura equivalente a la de un plato teorico, a unas 0,8 pulgadas. Con una razon del orden de 7:1 entre el volumen del deposito y el volumen de la caldera se ha extraido, como maximo, un 98 por ciento del tritio contenido en el deposito, en 28 dias de destilacion continua, trabajando con un caudal de 100 ml/h. Es decir, el factor de reconcentracion del tritio es de 6,3. Aumentando el caudal a 140 ml/h, se ha extraido el 92 por ciento del tritio en 11 dias. Se ha comprobado que aun cuando las condiciones experimentales permanecen iguales, no siempre es posible obtener el mismo factor de reconcentracion. En la memoria se examinan las causas de esta variacion. (author)[ru]
Byl issledovan metod rekontsentratsii tritiya putem obshchej oroshaemoj distillyatsii vody pod ponizhennym davleniem s primeneniem sluchajno nasadochnykh kolonn. Dlya maksimal'nogo udaleniya tritiya iz rezervuara emkost'yu v 1 litr byl neobkhodim rabochij period v neskol'ko nedel'. S ehtoj tsel'yu byla razrabotana polnost'yu avtomaticheskaya fraktsionnaya sistema, vklyuchavshaya v sebya pribor dlya avtomaticheskogo vzyatiya obraztsov pod ponizhennym davleniem, s tem chtoby distillyatsiya prokhodila pri minimume ruchnoj raboty. Dlya sokrashcheniya vozmozhnostej zakhlebyvaniya osnovy kolonny, kotoroe proiskhodit vsledstvie davleniya osadka nasadki v techenie dlitel'nogo vremeni v meste soprikosnoveniya kolonny i oroshayushchej vody, bylo sdelano eshche odno novoe prisposoblenie. Svojstva nekotorykh imeyushchikhsya v prodazhe nasadok kolonn byli issledovany v vodnykh usloviyakh. Dayutsya podrobnosti predvaritel'noj obrabotki nasadki dlya ustraneniya narusheniya raspredeleniya potoka v zhidkosti s vysokim poverkhnostnym natyazheniem i uchityvayutsya faktory obogashcheniya. Pri ispol'zovanii v vode predvaritel'no obrabotannykh metallicheskikh kolets iz fosfora i bronzy nizkaya vysota kolonny, ehkvivalentnaya odnoj teoreticheskoj tarelke, sostavila okolo 0,8 dyujma. Pri sootnoshenii mezhdu rezervuarom i bojlerom poryadka 7:1 maksimum 98% tritiya, nakhodyashchegosya v rezervuare, ustranyaetsya posredstvom nepreryvnoj distillyatsii v techenie 28 dnej pri propusknoj sposobnosti 100 millilitrov v chas. EHto opredelyaet koehffitsient rekontsentratsii tritiya, ravnyj 6,3. Pri uvelichenii propusknoj sposobnosti do 140 millilitrov v chas bylo udaleno 92% tritiya v techenie 11 dnej. Odnako ukazyvaetsya, chto so vremenem vosproizvodimost ' koehffitsienta rekontsentratsii var'iruetsya, i v doklade obsuzhdayutsya prichiny ehtogo. (author)Original Title
La reconcentration du tritium par distillation; Rekontsentratsiya tritiya distillyatsiej; Reconcentracion del tritio por destilacion
Primary Subject
Source
International Atomic Energy Agency, Vienna (Austria); 380 p; Jan 1962; p. 105-120; Symposium on Tritium in the Physical and Biological Sciences; Vienna (Austria); 3-10 May 1961; ISSN 0074-1884;
; 6 figs., 2 tabs., 8 refs.

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AbstractAbstract
No abstract available
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ANS winter meeting; San Francisco, CA, USA; 27 Nov 1977; See CONF-771109--. Published in summary form only.
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Journal Article
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Transactions of the American Nuclear Society; v. 27 p. 408
Country of publication
ACTINIDE COMPOUNDS, ACTINIDE NUCLEI, ALPHA DECAY RADIOISOTOPES, CHALCOGENIDES, EVEN-ODD NUCLEI, HEAVY NUCLEI, ISOMERIC TRANSITION ISOTOPES, ISOTOPES, MINUTES LIVING RADIOISOTOPES, NUCLEI, OXIDES, OXYGEN COMPOUNDS, RADIOISOTOPES, URANIUM COMPOUNDS, URANIUM ISOTOPES, URANIUM OXIDES, YEARS LIVING RADIOISOTOPES
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AbstractAbstract
[en] The column packer described is a simple, inexpensive device that allows packing the column in the gas chromatographic oven
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Journal Article
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Anal. Chem; v. 50(3); p. 543-544
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