Storage of seawater for nutrients analysis

The effects of different storage procedures on the analysis of nitrate, phosphate and silicate in seawater samples have been compared. The storage procedures included freezing and refrigeration of seawater samples, the latter with and without the addition of chloroform as a preservative. Refrigeration of the samples (1-3°C) up to 6 days, without preservative, was found to be the most reliable storage procedure. For periods longer than 6 days, addition of chloroform (0.5-1% v/v) will preserve the samples for months without significant losses in accuracy and precision

The Role of Diffusion in ISOL Targets for the Production of radioactive Ions Beams

On line isotope separation techniques (ISOL) for production of ion beams of short-lived radionuclides require fast separation of nuclear reaction products from irradiated target materials followed by a transfer into an ion source. As a first step in this transport chain the release of nuclear reaction products from refractory metals has been studied systematically and will be reviewed. High-energy protons (500-1000MeV) produce a large number of radionuclides in irradiated materials via the nuclear reactions spallation, fission and fragmentation. Foils and powder of Re, W, Ta, Hf, Mo, Nb, Zr, Y, Ti and C were irradiated with protons (600-1000MeV) at the Dubna synchrocyclotron and at the CERN PS-booster to produce different nuclear reaction products. The main topic of the paper is the determination of diffusion coefficients of the nuclear reaction products in the target matrix, data evaluation and a systematic interpretation of the data. The influence of the ionic radius of the diffusing species and the lattice type of the host material used as matrix or target on the diffusion will be evaluated from these systematics. Special attention was directed to the release of group I, II and III-elements. Arrhenius plots lead to activation energies of the diffusion process

Production yields of noble-gas isotopes from ISOLDE UCx_{x}/graphite targets

Yields of He, Ne, Ar, Kr and Xe isotopic chains were measured from UC$_{x}$/graphite and ThC$_{x}$/graphite targets at the PSB-ISOLDE facility at CERN using isobaric selectivity achieved by the combination of a plasma-discharge ion source with a water-cooled transfer line. %The measured half-lives allowed %to calculate the decay losses of neutron-rich isotopes in the %target and ion-source system, and thus to obtain information on the in-target %productions from the measured yields. The delay times measured for a UC$_x$/graphite target allow for an extrapolation to the expected yields of very neutron-rich noble gas isotopes, in particular for the ``NuPECC reference elements'' Ar and Kr, at the next-generation radioactive ion-beam facility EURISOL. \end{abstract} \begin{keyword} % keywords here, in the form: keyword \sep keyword radioactive ion beams \sep release \sep ion yields \sep ISOL (Isotope Separation On-Line) \sep uranium and thorium carbide targets. % PACS codes here, in the form: \PACS code \sep code \PACS 25.85.Ge \sep 28.60+S \sep 29.25.Rm

Quadrupole-deformed and octupole collective bands in 228^{228}Ra

Spins and parities for collective states in $^{228}$Ra have been determined from conversion electron measurements with a mini-orange $\beta$-spectrometer. The fast-timing $\beta\gamma\gamma(t)$ method has been used to measure lifetimes of T$_{1/2}$=550(20) ps and 181(3) ps for the $2^{+}_{1}$ and $4^{+}_{1}$ members of the K=0$^{+}$ band, and T$_{1/2} \leqslant$ 7 ps and $\leqslant$ 6 ps for the $1^{-}_{1}$ and $3^{-}_1$ members of the K = $0^{-}$ band, respectively The quadrupole moments, $Q_{0}$ deduced from the B (E2; 2$_{1}^{+} \rightarrow 0_{1}^{+}$) and B (E2; 4$_{1}^{+} \rightarrow 2_1^{+}$) rates are in good agreement with the previously measured value and the systematics of the region. However, the B(E1) rates of $\geqslant$ 4 × 10$^{−4}$ e$^{2}$fm$^{2}$, which represent the first B(E1) measurements for this nucleus, are at least 25 times larger than the value previously suggested for $^{228}$Ra. The new results are consistent with the B(E1) rates recently measured for the neighbouring $^{227}$Ra and reveal octupole correlations in $^{228}$Ra

Sammenlignende laboratorieprøvninger (SLP) – Analyse av ferskvann. SLP 11-20

Under en sammenlignende laboratorieprøvning gjennomført i mars – april 2011 bestemte 56 av 59 påmeldte laboratorier pH, konduktivitet, turbiditet, farge, UV-absorpsjon, natrium, kalium, kalsium, magnesium, hardhet, alkalitet, klorid, sulfat, fluorid, totalt organisk karbon, kjemisk oksygenforbruk (CODMn), fosfat, totalfosfor, nitrat, totalnitrogen, aluminium, bly, jern, kadmium, kobber, krom, mangan, nikkel, sink, antimon og arsen i vann. Prøvene ble laget ved å tilsette kjente stoffmengder til vann fra to innsjøer, og som på forhånd var filtrert gjennom membranfilter med porevidde 0,45 µm. Totalt ble 76 % av resultatene vurdert som akseptable, en andel som er noe høyere enn for fjorårets SLP, men omtrent på nivå med de foregående. Best resultater viser kjemisk oksygenforbruk med andel akseptable resultater på 96 %. De svakeste resultater ble observert for fluorid med 23 % akseptable resultater. Laboratoriene må ta hensyn til konsentrasjonsområde ved evalueringen av sine resultater. Det er stor variasjon i analysekvaliteten hos enkelte laboratorier, og de som har avvikende resultater må snarest igangsette tiltak for å forbedre kvaliteten på bestemmelsene. Antimon og arsen ble også denne gangen inkludert, og med overveiende gode resultat

Tvang som indikator for angst og stress hos mennesker med autisme

Children with Autism Spectrum Disorder (ASD) display a variety of repetitive behaviour. Such conduct is a core feature of ASD. We wanted to observe if there was an association between anxiety and repetitive behaviours among these people. Repetitive behaviour is also a characteristic feature in Obsessive Compulsive disorder (OCD). We wanted to consider similarities and differences between the restricted repetitive behaviour seen in ASD and the one seen in OCD. Terms like compulsions and obsessions have been used to describe the repetitive behaviour seen in people with Autism. For the diagnose OCD, it is a criteria that the compulsions and obsessions are intrusive and unwanted. Because people with Autism have problems expressing themselves, it is difficult to say whether they have a comorbid OCD or if the symptoms are an integrated part of their ASD. The repetitive behaviour seen in people with Autism is in general less complex and organised compared to the behaviour seen in people with OCD. We found that children with Autism reported a higher degree of anxiety than the control groups and that anxiety increases the restricted, repetitive behaviour patterns seen in Autism. Some researches suggest that the repetitive behaviour observed, is a coping strategy these individuals have towards anxiety and stress. For this reason, it is important keeping this in mind while working with individuals with ASD