[en] Phoenix tree (Firmiana simplex) seed oil is a novel oil which is rich in sterculic acid. Sterculic acid, a cyclopropene fatty acid, can be used as the inhibitor of the stearoyl-CoA desaturase system and mammary carcinomas growth. In this work, Lipozyme TLIM-catalyzed hydrolysis of the novel Phoenix tree seed oil was used to prepare sterculic acid. High temperature GC-FID and the degree of hydrolysis (DH) were used to monitor the reaction progress. Effects of reaction variables on the hydrolysis were evaluated and optimized using response surface methodology. Results showed that sterculic acid can be successfully prepared from the novel seed oil, and the effect of reaction variables on the hydrolysis decreased in the order of reaction time > enzyme load > temperature. A high yield of fatty acids (DH, 98.2±0.8%) can be obtained under optimized conditions (45 ºC, mass ratio of water to oil 10:1, enzyme load 10%, and 18 h). The Arrhenius equation for the hydrolysis was LnV0 = 9.12 − 4721/T. The activation energy was 39.25KJ/mol. The kinetic values for Vmax, K/m were 0.232mol/(L∙min) and 0.084 mol/L, respectively.

No abstract available

[en] A simple analytical method for simultaneous determination of ⁴¹Ca and ⁹⁰Sr in nuclear reactor concrete was developed. Different methods such as acid leaching and alkali fusion were investigated for the decomposition of the samples and for the separation of Ca and Sr from the matrix. Hydroxide and carbonate precipitation was used to separate Ca and Sr from the matrix elements as well as from each other. The chemical yields of the separation procedures for ⁴¹Ca and ⁹⁰Sr and 80%-90% and the decontamination factors for all interfering radionuclides are more than 10⁴. The detection limits of the analytical method for ⁴¹Ca and ⁹⁰Sr are 0.020 and 0.015 Bq, respectively. The methods developed here were used in the determination of ⁴¹Ca in heavy concrete from two concrete cores in the Danish research reactor DR-2. (orig.)

[en] The Danish straits the transit area between the North Atlantic and the Baltic Sea has been monitored for ⁹⁹Tc and ¹³⁷ Cs twice per year in the project period. Furthermore, several samples of seawater and seaweed have been analysed for ¹²⁹ I by neutron activation analysis. The Sellafield discharge rate of ⁹⁹Tc showed a distinct peak in 1995. The peak was present in the in-flowing bottom water in the Danish straits in June 1999, i.e. 4 years after the discharge. Since then, concentrations have decreased in accordance with the discharge rate. This confirms an earlier estimate of the transit time based on the large ¹³⁷ Cs discharges before the Chernobyl accident. The ¹³⁷Cs concentration in the Danish straits is now dominated by the outflow of low-saline water from the Baltic and is thus inversely related to the salinity, whereas ⁹⁹Tc concentrations are positively correlated with salinity as the concentration is dominated by the Sellafield discharges. ¹²⁹ I discharges to the sea have increased sharply during the 1990s especially from La Hague in France. Results from time-series seaweed (Fucus vesiculosus) samples show, that the ¹²⁹ I signal is penetrating not only to the Kattegat (Klint) but even to Bornholm in the Baltic (au)

[en] Analysis of Beta Radionuclides is performed at the following stages in the decommissioning of nuclear facility: Preparation (investigating the background radioactivity around NPP). Plant Cleanout: Removal of most radioactive component such as spent fuel elements, reactor internals, reactor vessel, etc. which is transferred for storage and disposal of high level waste. (Evaluation of radioactivity before transferring) Decontamination: Removal of contamination from surfaces of facilities or equipment by chemical or mechanical methods, which can reduce the waste volume and active level in the waste. (Measurement of radioactivity to evaluation the decontamination, and estimation of radioactivity in the waste). Dismantling: Equipment within the facility are dismantled and classified by estimation of the Radioactivity; Demolition and site clearance; Buildings demolished and radioactive wastes removed to storage or disposal facilities after estimation of the radioactivity in the waste. Release of the site to alternative use (measure the radioactivity level in the released area). (This contribution is made up of pictures from a PowerPoint-presentation)

[en] This report compiled all abstracts presented in the NKS Workshop on Radioanalytical Chemistry at Risoe, Roskilde, Denmark in 2-6^th Sept. 2013. Total 35 participants registered to the workshop, among them 18 from Sweden, 5 from Denmark, 3 from Finland, and 3 from Norway, there are also 6 participants from Germany, France, Slovenia, Korea, Turkey, and China. The workshop consists two part, 3 days lab practices and 2 days lectures/presentation. 3 lab practices were organized, i.e. (1) Radiochemical separation of Pu and ICP-MS measurement of Pu isotopes; (2) Radiochemical separation of ²¹⁰Po and ²²⁶Ra and their alpha spectrometry measurement; and (3) Radiochemical separation of ⁵⁵Fe, ⁶³Ni, ⁹⁰Sr and their LSC measurement. Among them, each participant can participate in 2 lab practices. 15 invited lectures are given by the experts in their specific fields, 8 oral and 6 poster presentations are given by the participants. The abstracts of all presentations are included in this report. (Author)

[en] This report summarized the progress in the development and improvement of radioanalytical methods for decommissioning and waste management completed in the NKS-B RadWaste 2011 project. Based on the overview information of the analytical methods in Nordic laboratories and requirement from the nuclear industry provided in the first phase of the RadWaste project (2010), some methods were improved and developed. A method for efficiently separation of Nb from nuclear waste especially metals for measurement of long-lived 94Nb by gamma spectrometry was developed. By systematic investigation of behaviours of technetium in sample treatment and chromatographic separation process, an effective method was developed for the determination of low level 99Tc in waste samples. An AMS approachment was investigated to measure ultra low level 237Np using 242Pu for AMS normalization, the preliminary results show a high potential of this method. Some progress on characterization of waste for decommissioning of Danish DR3 is also presented. (Author)

[en] Context. Here, GeV gamma-ray pulsations from over 140 pulsars have been characterized using the Fermi Large Area Telescope, enabling improved understanding of the emission regions within the neutron star magnetospheres, and the contributions of pulsars to high energy electrons and diffuse gamma rays in the Milky Way. The first gamma-ray pulsars to be detected were the most intense and/or those with narrow pulses. Aims. As the Fermi mission progresses, progressively fainter objects can be studied. In addition to more distant pulsars (thus probing a larger volume of the Galaxy), or ones in high background regions (thus improving the sampling uniformity across the Galactic plane), we detect pulsars with broader pulses or lower luminosity. Adding pulsars to our catalog with inclination angles that are rare in the observed sample, and/or with lower spindown power, will reduce the bias in the currently known gamma-ray pulsar population. Methods. We use rotation ephemerides derived from radio observations to phase-fold gamma rays recorded by the Fermi Large Area Telescope, to then determine the pulse profile properties. Spectral analysis provides the luminosities and, when the signal-to-noise ratio allows, the cutoff energies. We constrain the pulsar distances by different means in order to minimize the luminosity uncertainties. Results. We present six new gamma-ray pulsars with an eclectic mix of properties. Three are young, and three are recycled. They include the farthest, the lowest power, two of the highest duty-cycle pulsars seen, and only the fourth young gamma-ray pulsar with a radio interpulse. Finally, we discuss the biases existing in the current gamma-ray pulsar catalog, and steps to be taken to mitigate the bias.

[en] Evolution details of the planar and vertical Lyapunov families around the three collinear libration points in the restricted three-body problem were studied. Researches before were generally restricted to be within the colliding orbits with the primaries and for fixed mass parameters μ. In this paper, members after colliding orbits were computed. With increasing μ, how these families evolve was studied.

[en] A NKS-B workshop on radioanalytical chemistry for radioecology and waste management was held at Risoe, Roskilde, Denmark in 16-20th November 2009. The workshop was organized as 3 days lectures and presentations and two days laboratory practice. 48 peoples participated the workshop, including 32 young participants from Denmark, Finland, Norway, Sweden, Lithuania and Ireland. This report gives a brief description of the workshop and an evaluation of the workshop by statistic analysis of questionnaires feed back from the participants. The book of abstracts and proceedings presented in the workshop is enclosed. (author)