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Lehrum, Hans Vigeland; Andersen, Niels Højmark; Eriksen, Dag Øistein; Hansen, Eddy Walther & Omtvedt, Jon Petter
(2020).
NMR Studies of Aliquat 336 in toluene after contact with saline solutions - Determination of ionic content.
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Lerum, Hans V.; Sand, Svetlana; Eriksen, Dag Øistein; Hansen, Eddy Walther; Wibetoe, Grethe & Omtvedt, Jon Petter
(2018).
Determination of Distribution Ratios in Liquid-liquid
Extraction of Hydrometallurgical Process Solutions using ICP-MS and
Radiotracer Techniques.
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John, Jan; Retegan, Teodora; Lehto, Jukka; Omtvedt, Jon Petter & Skipperud, Lindis
(2016).
CINCH–II Project – A Milestone in the Coordination of Education and Training in Nuclear- and Radiochemistry in Europe.
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Lerum, Hans Vigeland; Bouzga, Aud Mjærum; Jørgensen, Sissel; Petersen, Dirk; Eriksen, Dag Øistein & Hansen, Eddy Walther
[Show all 8 contributors for this article]
(2016).
Study of cadmium extraction from aqueous solutions with high chloride concentration using radiotracer and NMR
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Lerum, Hans Vigeland; Bouzga, Aud Mjærum; Jørgensen, Sissel; Petersen, Dirk; Eriksen, Dag Øistein & Hansen, Eddy Walther
[Show all 8 contributors for this article]
(2016).
LIQUID-LIQUID EXTRACTION OF CADMIUM CHLORIDE COMPLEXES STUDIED BY NMR.
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Retegan, Teodora; Ekeberg, Christian; John, Jan; Cuba, Vaclav; Nemec, Mojmir & Lehto, Jukka
[Show all 14 contributors for this article]
(2015).
Cooperation in Education and Training in Nuclear and Radiochemistry in Europe – A Continuous Process.
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John, Jan; Cuba, Vaclav; Nemec, Mojmir; Retegan, Teodora; Ekeberg, Christian & Lehto, Jukka
[Show all 16 contributors for this article]
(2014).
Cooperation in Education and Training in Nuclear- and Radiochemistry in Europe.
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John, Jan; Retegan, Teodora; Lehto, Jukka; Omtvedt, Jon Petter & Skipperud, Lindis
(2013).
CINCH-II: Next step in the coordination of education in nuclear and radiochemistry in Europe.
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John, Jan; Retegan, Teodora; Lehto, Jukka; Koivula, Teija; Scully, Paul J. & Walther, Clemens
[Show all 13 contributors for this article]
(2013).
Next step in the coordination of education in nuclear and radiochemistry in Europe.
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Bjørnstad, Tor; Eriksen, Dag Øystein & Omtvedt, Jon Petter
(2013).
Radiochemistry and hydrometallurgy - two synergetic fields.
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Wærsted, Frøydis Meen; Omtvedt, Jon Petter; Wibetoe, Grethe & Vogt, Rolf David
(2013).
The role of particles and phosphorus bound to particles in eutrophication.
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Omtvedt, Jon Petter
(2008).
Hvordan får vi energi fra thorium?
Naturfag.
ISSN 1504-4564.
1,
p. 28–32.
Show summary
Denne artikkelen er skrevet med tanke på å gi grunnleggende informasjon om kjerneenergiverk som benytter thorium som brennstoff. Målet er at læreren skal forstå de viktigste mulighetene og begrensningene på en slik måte at hun/han kan formidle dette videre. Artikkelen vil ikke diskutere for eller imot kjerneenergiverk, den diskusjonen overlates til andre fora. Det er forfatterens håp at artikkelen vil bidra til at både tilhengere og motstandere av kjerneenergi kan diskutere med utgangspunkt i et tryggere faglig grunnlag og dermed heve debattens kvalitet og verdi.
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Stølen, Svein; Gorbitz, Carl Henrik; Omtvedt, Jon Petter & Ødegaard, Knut Jørgen Røed
(2008).
Verdt å vite spesial: Grunnstoffene og periodesystemet.
[Radio].
NRK P2.
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Omtvedt, Jon Petter & Helgesen, Ole K.
(2008).
Spenning om thorium.
[Newspaper].
Teknisk ukeblad.
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Omtvedt, Jon Petter
(2008).
Recent developments in automated liquid-liquid extraction studies of transactinide elements.
Show summary
Liquid-liquid extraction (LLE) studies of Rf (Z=104), after physical preseparation with the Berkeley Gas-filled Separator, were performed. Based on the experience gained in these successful experiments, the computer controlled SISAK LLE system has been improved and developed further in order to be able to study transactinide elements heavier than Rf. In particular, the transfer from the recoil transfer chamber (RTC) (which transfer the recoils from the separator to a aerosol seeded gas-jet) to the chemistry apparatus and the acquisition system for the liquid scintillation detectors have been improved. The results from the RTC developments will be presented together with other improvements made to the SISAK centrifuge system and liquid-scintillation detectors.
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Samadani, Fereshteh & Omtvedt, Jon Petter
(2007).
Developing a SISAK extraction system for chemical study of element 108, hassium.
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Omtvedt, Jon Petter
(2007).
Fast and continuous liquid-liquid extraction with the computer controlled SISAK system.
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Opel, Karsten & Omtvedt, Jon Petter
(2007).
New Control System for SISAK.
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Omtvedt, Jon Petter & Hammerfjeld, Jon R.
(2006).
Lagde verdens tyngste grunnstoff.
[Newspaper].
Dagbladet.no.
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Omtvedt, Jon Petter; Alstad, Jorolf; Bjørnstad, Tor; Dullmann, C.E.; Folden III, C.M. & Gregorich, K.E.
[Show all 15 contributors for this article]
(2006).
“Chemical Properties of the Transactinide Elements Studied in Liquid Phase with SISAK”,
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Zheng, Li; Alstad, Jorolf; Bjørnstad, Tor; Polakova, Darina; Stavsetra, Liv & Omtvedt, Jon Petter
(2006).
”Influence of KCl on the extraction of rutherfordium homologues hafnium and zirconium from sulphuric acid with tri-octylamine in toluene”,
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Vogt, Rolf David; Solomonova, Polina; Gjessing, Egil & Omtvedt, Jon Petter
(2006).
Preparative gel fractionation of NOM for ecological studies - The fate of mercury in aquatic ecosystems.
Show summary
Forty years ago it was shown that dissolved humic substances (HS) in water could be separated into a number of different size fractions using the gel-matrix Sephadex (1). Since then a number of different techniques and methods have been introduced for the purpose to define and describe the physical properties and chemical composition of HS. During the last few decades the awareness of the ecological importance of this complicated organic matter has increased and it is realized that more knowledge on biological properties and biological functions of HS are needed.
We have re-introduced preparative gel-filtration, in order to be able to learn more about the fate of micro pollutants in fresh-water ecosystems. Mercury (Hg) is an element of considerable health concern, mostly due to its global distribution and its bio-magnification potentials in water. The important role of HS both as carrier and as mediator of Hg transport from soil to the surface water is demonstrated by elevated Hg concentrations in humic-rich waters.
The purpose of the work to be presented is to fractionate “Hg-spiked” dissolved natural organic matter (NOM), and to investigate the Hg distribution on the NOM in detail. The biological properties of the resulting fractions will later be studied in co-operation with ecologists.
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Omtvedt, Jon Petter
(2005).
OCL@SAFE: Transactinide homologues available at the Oslo Cyclotron Laboratory for model studies.
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Dirdal, Ragnhild Elise & Omtvedt, Jon Petter
(2023).
Selective Recovery of Copper from Municipal Solid Waste Incineration Bottom Ash.
Kjemisk Institutt, Universitetet i Oslo.
Show summary
A hydrometallurgical process was investigated as a method to selectively recover copper from municipal solid waste incineration (MSWI) bottom ash. In Norway, bottom ash is mainly disposed of instead of being utilized. When landfilled, hazardous components, such as copper and zinc, can potentially be released to the environment and cause groundwater pollution. Therefore, extraction of copper and zinc would be a favorable solution for both disposal and utilization of bottom ash, as well as a potential source for secondary materials. In order to be economically feasible to recover metals from bottom ash, other metals and components probably need to be recovered as well. Acidic leaching solutions are most commonly used, however, alkaline solutions are generally more selective, less corrosive and have a lower reagent consumption according to previous studies. Ammonia-ammonium carbonate (AAC) is stated to be a suitable choice of leach solution for selective recovery of copper and zinc. The different substances of the AAC solution can be recovered, recombined and used in subsequent processing. In the present study, AAC leaching of bottom ash followed by a cementation procedure in order to selectively precipitate copper was investigated. Co-dissolution of zinc was also monitored during the study due to possible subsequent recovery based on procedures established in previous studies. MSWI bottom ash originating from different incineration plants in Norway was characterized and used in the study. The bottom ash was leached with an aqueous solution of ammonia (NH3) and ammonium carbonate ((NH4)2CO3). In order to efficiently extract copper from bottom ash, the AAC leaching procedure was optimized in terms of particle size, total ammonia concentration, leaching temperature, pulp density (solid/liquid ratio), and leaching time. The optimal leaching conditions were found to be 4.7 M, 60 C, 100 g bottom ash per liter leach solution and 180 minutes of leaching time, before the liquid and solid phases were separated. The pregnant leach solution (PLS) was quantitatively analyzed with inductively coupled plasma optical emission spectroscopy (ICP-OES). Extraction of more than 98 % of the copper from bottom ash was achieved. The copper was subsequently precipitated from the PLS by a cementation procedure with metallic zinc dust. After cementation, the PLS was quantitatively analyzed with ICP-OES and the solid residue was qualitatively analyzed using X-ray diffraction. More than 90% of copper was recovered from the PLS by cementation.
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Rafique, Waqas; Riss, Patrick & Omtvedt, Jon Petter
(2018).
Synthesis of Fluorine-18 Labelled Radiotraces and Their Pre-Clinical and Clinical Characterization.
Kjemisk institutt, Universitetet i Oslo.
ISSN 1501-7710.
2018(2013).
Show summary
Positron emission tomography (PET) is one of the most sensitive in vivo imaging techniques available to clinicians and researchers. It helps in understanding the biological interactions and mechanism of various diseases through use of radiolabelled compounds called radiotracers.
Herein is described the development of facile radiolabelling approaches for straightforward access to 18F-labelled trifluoromethyl radiotracers. Direct nucleophilic radiofluorination of difluorovinyl precursors was achieved for 18F-trifluoromethylation of aliphatic compounds, and applied to the radiosynthesis of [18F]lansoprazole and N-methyl[18F]lansoprazole. The compounds were used to analyze the blood-brain barrier penetration in healthy persons and for the detection of tau-neurofibrillary tangles in Alzheimer’s patients.
For 18F-trifluoromethylation of aromatic compounds, in situ synthesis of Cu[18F]CF3 was achieved and used in 18F-trifluoromethylation of iodo-arenes using a single vial one-step method. The procedure was applied for radiosynthesis of a derivative of AH7921, which is a sub-type selective mu-opioid receptor agonist. The developed procedures are applicable to available radiosynthesis hardware, and provide access to desired compounds within 40 minutes in high radiochemical yields.
In addition, a series of new compounds were synthesized with aim to discover the new radioligands based on modifications to the lead compounds i.e. lansoprazole and AH7921. Several interesting candidates with good combination of affinity and selectivity were identified from each series, and radiolabelled with fluorine-18. The newly developed 18F-labelled compounds have good potential to provide the in vivo characterization of tau-neurofibrillary tangles and quantification of the opioid receptors using the PET imaging.
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Kristiansen, Håvard; Omtvedt, Jon Petter & Eriksen, Dag Øistein
(2015).
Radiochemical analysis of cadmium in nitric and phosphoric acid.
Universitetet i Oslo.
Show summary
The goal of this research project was to find a way to produce fertilizer with low concentrations of cadmium from phosphate rock with relatively high cadmium concentrations. A method for the production of a radioactive cadmium tracer was developed and implemented. The tracer was used to investigate how cadmium behaves in a critical step of a process for fertilizer production. A method for measuring the radioactivity from 109Cd was developed, tested and implemented. The 109Cd radiotracer and the detection method were used to investigate solvent extraction from nitric and phosphoric acid, as well as from an industrial fertilizer-production solution. After a screening of a selection of possible commercial extractants, di-(2-ethylhexyl)phosphoric acid (HDEHP) and di-(2,4,4-trimethyl pentyl)dithiophosphinic acid (Cyanex 301) where studied closely. The results were interpreted in order to propose chemical equations for how HDEHP and Cyanex 301 react with cadmium and the acid matrix.
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Lehto, Jukka; Omtvedt, Jon Petter; Popic, Jelena Mrdakovic; Nemec, Mojmir & Koivula, Teija
(2015).
Workshop on Nuclear Chemistry Education and Training in Europe, CINCH-II Deliverable D4.5.
NMBU/CERAD.
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Lerum, Hans Vigeland & Omtvedt, Jon Petter
(2014).
Preparations for a Reduction and Liquid-Liquid Separation Experiment for Element 106, Seaborgium.
Universitetet i Oslo.
Show summary
The purpose of this thesis was to check if it was possible to prepare a mechanical and chemical system that can reduce Seaborgium, element 106, and separate between the reduced and the oxidized state. To do this the liquid-liquid extraction system SISAK has been coupled to a flow electrolytic column, which is able to reduce single atoms. To overcome the high difference in flow rate between these two systems a membrane degasser has been utilized which managed to severely reduce the amount of fluid needed. Several extraction schemes have been tested. These had the goal that they should manage to strongly extract only one of the oxidation states. As a model for Sg experiments Mo and W have been used. During the work of this thesis it has been shown that it is possible to reduce and separate between two oxidation states of Mo. Furthermore, slight separation has been achieved for W in some systems. This have been done to model Sg in such a way that it is realistic to believe that Sg will behave in the same way. In addition a proof of concept has been achieved were the newly developed membrane degasser, the flow electrolytic column and the SISAK centrifuge have been coupled together. This managed to reduce enough Mo and separate between the reduced and oxidized Mo species at a flow rate of 0.2 mL/s and with the aquatic solution 0.1 M HCl + 0.9 M LiCl and an organic solution of 0.01 M hinokitiol in Toluene. Some kinetic studies have been performed at 0.2 mL/s flow rate with HDEHP as an extractant in toluene and an aquatic solution of 0.1 m H2SO4. Additionally retention on the carbon electrode is discussed. The work presented in this thesis have been performed as a part of a large collaboration between the nuclear chemistry group at the university of Oslo, Norway and between the superheavy element group in Tokai, Japan. An importan part of this work has therefore been to set up a working SISAK set-up in Tokai and a working flow electrolytic column in Oslo.
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Samadani, Fereshteh; Omtvedt, Jon Petter & Bjørnstad, Tor
(2006).
Developing a SISAK extraction system for studies of element 108, hassium.
7Letras.
Show summary
The SISAK (i.e. Short-lived Isotope Studied by the AKufve -technique) system was used for investigation of the reaction between osmium tetroxide and NaOH as a model for chemical study of hassium. The result was a two- stage extraction procedure. In the first extraction stage, OsO4 was extracted from NaOH solutions of different concentrations into toluene and the following equilibrium constants for the reaction of OsO4 and NaOH were obtained: K´= (2.35 ± 0.04) • 104 for formation of Na[OsO4(OH)] and K″= 6 ±4 for formation of Na2[OsO4(OH)2] out of Na[OsO4(OH)]. The purpose of the second extraction stage was to transfer the activity from the aqueous phase into the organic phase in an efficient way. In order to fulfill this purpose the basic aqueous phase from the first extraction stage was acidified with HCl, HClO4 or H2SO4 and the activity was extracted into toluene either with or without tri-n-octylamine (TOA) as an extracting agent. The extraction efficiency in this stage was around 90% in both cases although there were indications that extraction with TOA had a somewhat higher distribution ratio. An attempt was also made to use Aliquat 336 as an extracting agent to transfer activity into the organic phase. This experiment showed that Aliquat 336 can extract the activity very efficiently. There was, however, a problem with the purity of the liquid phases.
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