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- Andersson, Sofie, 1976, et al.
(författare)
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Study of nitrate complex formation with Pm, Eu, Am and Cm using a solvent extraction technique
- 2004
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Ingår i: Radiochimica Acta. - : Walter de Gruyter GmbH. - 0033-8230 .- 2193-3405. ; 92:12, s. 863-867
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Tidskriftsartikel (refereegranskat)abstract
- The separation of actinides and lanthanides is an important question in the treatment of spent nuclear fuel in the transmutation concept. To find an efficient and well functioning separation process it is necessary to study the chemistry of the elements in the two groups in different aqueous media. The stability constants of the nitrate complex formation with Pm, Eu, Am and Cm were determined using solvent extraction. The extraction was studied using the synergistic system of 2,6-bis-(benzoxazolyl)-4-dodecyloxylpyridine and 2-bromodecanoic acid in tert-butyl benzene. As the nitrate ion concentration in the aqueous phase was increased, a decrease in separation between actinides and lanthanides was seen owing to complex formation between the different elements and the nitrate ions.
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- Andersson, Sofie, 1976, et al.
(författare)
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Berkelium nitrate complex formation using a solvent extraction technique
- 2006
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Ingår i: Radiochimica Acta. - : Walter de Gruyter GmbH. - 0033-8230 .- 2193-3405. ; 94:1, s. 59-61
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Tidskriftsartikel (refereegranskat)abstract
- The extraction of Bk(III) into an organic phase consisting of 2,6-bis-(benzoxazolyl)-4-dodecyloxylpyridine, 2-bromodecanoic acid and tert-butyl benzene as a function of nitrate ion concentration in the aqueous phase was studied in order to determine the stability constants of the formation of Bk nitrate complexes. Increasing the nitrate ion concentration in the aqueous phase will increase the nitrate complex formation and thus the extraction of metal ions will decrease. Measuring this decrease in distribution ratio and fitting the data points with an appropriate model gives the stability constants of the Bk nitrate complex formation. © by Oldenbourg Wissenschaftsverlag.
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- Andersson, Sofie, 1976
(författare)
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Extraction Properties of some Nitrogen-Containing Extractants and Determination of Nitrate Complex Formation for Lanthanides and Selected Actinides Using Solvent Extraction
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Partitioning and transmutation of spent nuclear fuel will reduce the amount of waste and its radiotoxicity in a long-term perspective. At the same time the energy content of the spent nuclear fuel can be used more efficiently by recycling of uranium and plutonium and by using energy from the transmutation reactor. To be able to efficiently transform the long-lived radiotoxic elements and avoid the production of more long-lived waste, it is necessary to separate some of the different elements. Solvent extraction is a useful technique for meeting the strict demands on purity and separation efficiency that must be fulfilled before the actual transmutation can occur. Methodologies for investigating basic properties of some synergic systems were tested. The protonation constants of 2,2':6',2''-terpyridine were investigated using solvent extraction and spectrophotometry. The influence of pH, ionic strength and ionic media was studied using the synergic system of 2,6-bis-(benzoxazolyl)-4-dodecyloxylpyridine and 2-bromodecanoic acid. The nitrate complex formation of some actinides and the lanthanides was also investigated using the same system. In the case of berkelium, these constants have not been determined before. Finally, extraction properties within the lanthanide series and between lanthanides and actinides were studied. A clear tetrad effect was found within the lanthanide group. A basic design was also made on a possible flow sheet for the solvent extraction system with 2,6-bis-(benzoxazolyl)-4-dodecyloxylpyridine and 2-bromodecanoic acid and a mixture of studied lanthanides and actinides. This demonstrates that in theory it is possible to reach the desired separation factors. The influence of uncertainties in distribution ratios and stability constant determinations was investigated. The stability constants are usually assumed to be non-correlated, which is often not the case. Given a certain value of the first stability constant, it is necessary to reduce the uncertainty interval of the second one because of their correlation. This will affect the calculated speciation in many chemical systems.
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- Ekberg, Christian, 1967, et al.
(författare)
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Uses of pH Electrodes in Nuclear Chemistry
- 2002
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Ingår i: Analytical and Bioanalytical Chemistry. - 1618-2642 .- 1618-2650. ; 374:5, s. 824-830
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Tidskriftsartikel (refereegranskat)abstract
- The determination and definition of pH is a controversial subject in many areas in chemistry. For these reasons the International Union of Pure and Applied Chemistry (IUPAC) has developed recommendations for pH measurement. These recommendations are currently (winter 2001) under revision - there will be increased emphasis on traceability of uncertainties in pH measurement. Here we describe how glass electrodes designed for measurement of pH are used in nuclear chemistry. The use of pH electrodes is then related to the IUPAC recommendations. In applied chemistry, e.g. nuclear chemistry, a pH is not sought as often as a hydrogen ion concentration or a simple equilibrium point during a titration. Ionic strengths are, moreover, often above the range in which the IUPAC recommendations apply. In these instances uncertainties must be assessed individually.
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- Hussain, Ahmed, 1985, et al.
(författare)
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A maternal diet of fatty fish reduces body fat of offspring compared with a maternal diet of beef and a post-weaning diet of fish improves insulin sensitivity and lipid profile in adult C57BL/6 male mice.
- 2013
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Ingår i: Acta Physiologica. - : Wiley. - 1748-1708 .- 1748-1716. ; 209:3, s. 220-234
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Tidskriftsartikel (refereegranskat)abstract
- Aim The maternal diet during pregnancy and lactation may affect the long-term health of the offspring. Our aim was to study how a fish or meat diet perinatal and after weaning affects body composition, insulin sensitivity and the profile of n-3 and n-6 polyunsaturated fatty acids (PUFAs) in breast milk, fat depots, skeletal muscle and liver in male adult mice offspring. Methods During gestation and lactation, C57BL/6 dams were fed a herring- or beef-based diet. Half of the pups in each group changed diets after weaning. In offspring, body composition measured by DEXA, plasma lipid profile and insulin sensitivity measured by euglycemic clamp or QUICKI were monitored to adulthood. Analysis of total FAs by GC-MS were performed in the diet, breast milk and in different tissues. Results At 9 week of age, offspring of herring-fed dams had less body fat than offspring of beef-fed dams. Mice fed herring after weaning had increased insulin sensitivity at 15 week of age, reduced total plasma cholesterol and triglyceride levels, and compared with beef-fed mice, larger interscapular brown adipose tissue depots. The FA composition of the maternal diet was mirrored in breast milk, and the herring diet significantly affected the FA profile of different tissues, leading to an increased content of n-3 PUFAs. Conclusion A herring-based maternal diet reduces body fat in the offspring, but the insulin sensitivity, plasma lipids and amount of brown adipose tissue are affected by the offspring's own diet; the herring diet is more beneficial than the beef diet.
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