A method for measuring radium activity using electrodeposition onto stainless steel from solutions to which platinum ions have been added was developed. This gave high recovery with reduced electroplating times, and yielded deposits giving alpha-spectra of high resolution. Retention of the decay products in the deposit allows inference of some Ra isotopes from measurement of the activities of the high energy Po daughters. Application of the method to determination of226Ra in a marine manganese deposit is described.
The aggregation pheromone of the western flower thrips,
(Thysanoptera: Thripidae), has previously been identified as the monoterpenoid ester neryl (
)-2-methylbutanoate. It attracts both male and female adults to traps in commercial glasshouses. In this paper, we investigate the rates of production of this compound at two male densities and in the presence or absence of an adult female. Solid-phase microextraction (SPME) was used to entrain live-male headspace odour and this was compared with external standards to obtain an estimate of pheromone production, which was about 100–300 pg male
. Significantly more pheromone was apparently produced per male at the higher density, but no firm conclusions could be drawn because the rates were close to the limits of resolution. The rate of production was not affected by the presence of a female thrips. Another male-headspace component, (
)-lavandulyl acetate, was only detectable at the higher male density.
Authors:D. Assinder, J. Hamilton-Taylor, M. Kelly, S. Mudge, and K. Bradshaw
The Esk estuary, U.K. receives inputs of dissolved and particulate plutoniun from discharges of waste into the Irish Sea from the Sellafield nuclear fuel reprocessing plant. Field and laboratory methods have been developed to examine the phenomenon of rapid plutonium remobilization from contaminated Esk sediments during estuarine mixing which was first identified in 1981.Both types of studies have shown comparable, non-conservative behavior for the two oxidation state categories of238Pu and239,240Pu (i.e. Pu (III/IV) and Pu (V/VI)) with enrichment in low salinity waters due to desorption of plutonium from resuspended sediments.
Authors:M. Fassbender, D. J. Jamriska, V. T. Hamilton, F. M. Nortier, and D. R. Phillips
Germanium-68 (270.8 d, EC 100%) is the parent nuclide of 68Ga, a β+ emitter important to positron emission tomography (PET). 68Ge is obtained by a (p,x) induced nuclear reaction on natural Ga. A typical Ga target assembly consists of liquid Ga contained in a Nb capsule, since Nb is one of the few metals resistant to liquid Ga. Zirconium-88 (83.4 d, via 93Nb(p, α2n)) is one longer-lived radioisotope generated by the proton irradiation of naturally mono-isotopic 93Nb. It decays into 88Y, which, in turn, has been considered a useful radiolabel surrogate for 90Y in the investigation of radiolabeled compounds for cancer radioimmunotherapy. This paper introduces a wet chemical procedure for the processing of Nb/Ga target capsules and the simultaneous recovery of 68Ge and 88Zr.
Authors:W. Taylor, J. Garcia, V. Hamilton, R. Heaton, D. Jamriska, M. Ott, D. Phillips, and S. Radzinski
The178m2Hf nucleus, with its long half-life (31 y) and high-spin isomeric state (16+) is desired for new and exotic nuclear physics studies. The Los Alamos Radioisotope Program irradiated a kilogram of natural
tantalum at the Los Alamos Meson Physics Facility in early 1981. After fifteen years of decay, this target was ideal for the
recovery of178m2Hf. There was more than a millicurie of178m2Hf produced during this irradiation and there has been a sufficient period of time for most of the other hafnium radioisotopes
to decayed away. Traditionally, separation techniques for recovering hafnium isotopes from tantalum targets employ solvent
extractions with reagents that are considered hazardous. These techniques are no longer condoned because they generate a mixed-waste
(radioactive and hazardous components) that can not be treated for disposal. In this paper we describe a new and unique procedure
for the recovery of hafnium radioisotopes from a highly radioactive, proton irradiated, tantalum target using reagents that
do not contribute a hazardous waste component.
Authors:W. Taylor, D. Jamriska, V. Hamilton, R. Heaton, D. Phillips, R. Staroski, J. Garcia, J. Garcia, and M. Ott
Since the mid-1970s the Los Alamos Medical Radioisotope Program has been irradiating target materials to produce and recover radioisotopes for applications in medicine, environmental science, biology, physics, materials research, and other disciplines where radiotracers find utility. By necessity, the chemical processing of targets and the isolation of radioisotopes generates radioactive waste materials. In recent years there have been federal mandates requiring us to discontinue the use of hazardous materials and to minimize radioactive waste volumes. As a result, substantial waste reduction measures have been introduced at the irradiation facility, in processing approaches, and even in the ways the product isotopes are supplied to users.
Authors:P. Povinec, M. Pham, J. Sanchez-Cabeza, G. Barci-Funel, R. Bojanowski, T. Boshkova, W. Burnett, F. Carvalho, B. Chapeyron, I. Cunha, H. Dahlgaard, N. Galabov, L. Fifield, J. Gastaud, J. Geering, I. Gomez, N. Green, T. Hamilton, F. Ibanez, M. Ibn Majah, M. John, G. Kanisch, T. Kenna, M. Kloster, M. Korun, L. Liong Wee Kwong, J. La Rosa, S. Lee, I. Levy-Palomo, M. Malatova, Y. Maruo, P. Mitchell, I. Murciano, R. Nelson, A. Nouredine, J. Oh, B. Oregioni, G. Le Petit, H. Pettersson, A. Reineking, P. Smedley, A. Suckow, T. van der Struijs, P. Voors, K. Yoshimizu, and E. Wyse
A reference material designed for the determination of anthropogenic and natural radionuclides in sediment, IAEA-384 (Fangataufa
Lagoon sediment), is described and the results of certification are presented. The material has been certified for 8 radionuclides
(40K, 60Co, 155Eu, 230Th, 238U, 238Pu, 239+240Pu and 241Am). Information values are given for 12 radionuclides (90Sr, 137Cs, 210Pb (210Po), 226Ra, 228Ra, 232Th, 234U, 235U, 239Pu, 240Pu and 241Pu). Less reported radionuclides include 228Th, 236U, 239Np and 242Pu. The reference material may be used for quality management of radioanalytical laboratories engaged in the analysis of radionuclides
in the environment, as well as for the development and validation of analytical methods and for training purposes. The material
is available from IAEA in 100 g units.