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The “age” of a sample of uranium is an important aspect of a nuclear forensic investigation and of the attribution of the material to a source. The 230Th- 234U chronometer can be used to determine the production date of even very recently-produced material ( 234U half life = 245250 ± 490 years; 230Th half life = 75690 ± 230 years [1]), provided that the 230Th/234U at the time of formation is known, and that there has been no Th-U fractionation in the sample since production. For most samples of uranium, ages determined with this chronometer are “model ages”, because they are based on the assumptions of a) some initial amount of 230Th in the sample, and b) closed-system behavior of the sample since production. The uranium standard reference materials originally prepared and distributed by the former US National Bureau of Standards and now distributed by New Brunswick Laboratory as certified reference materials (NBS SRM = NBL CRM) are good candidates for materials where these assumptions may be tested. The U isotopic standards have known purification and production dates and closed-system behavior in the solid form (U3O8) may be reliably assumed. In addition, these materials are widely available and can serve as informal round-robin inter-laboratory comparison samples. We determined 230Th-234U model ages for seven of these isotopic standards by isotope dilution mass spectrometry using a multi-collector ICP-MS. The standards dated for this study are U005-A, U010, U030-A, U100, U850, U900 and U970. Model ages obtained range from ∼ 30 to ∼ 52 years ago (reference date: 5-May-2009). The model age of U100 is the same as the purification date, within uncertainty. The other six standards analyzed all give model ages older than the purification dates of record. The magnitude of the discrepancy between model age and purification date does not correlate with the model age or the amount of 232Th in the samples. This indicates that excess 230Th in these six standards results from incomplete purification during production.

This is the standard operating procedure used by the Isotope Ratio Mass Spectrometry Group of the Chemical Sciences Division at LLNL for the preparation of a sample of uranium oxide or uranium metal for {sup 230}Th-{sup 234}U age-dating. The method described here includes the dissolution of a sample of uranium oxide or uranium metal, preparation of a secondary dilution, spiking of separate aliquots for uranium and thorium isotope dilution measurements, and purification of uranium and thorium aliquots for mass spectrometry. This SOP may be applied to uranium samples of unknown purity as in a nuclear forensic investigation, and also to well-characterized samples such as, for example, U{sub 3}O{sub 8} and U-metal certified reference materials. The sample of uranium is transferred to a quartz or PFA vial, concentrated nitric acid is added and the sample is heated on a hotplate at approximately 100 C for several hours until it dissolves. The sample solution is diluted with water to make the solution approximately 4 M HNO{sub 3} and hydrofluoric acid is added to make it 0.05 M HF. A secondary dilution of the primary uranium solution is prepared. Separate aliquots for uranium and thorium isotope dilution measurements are taken and spiked with {sup 233}U and {sup 229}Th, respectively. The spiked aliquot for uranium isotope dilution analysis is purified using EiChrom UTEVA resin. The spiked aliquot for thorium isotope dilution analysis is purified by, first, a 1.8 mL AG1x8 resin bed in 9 M HCl on which U adsorbs and Th passes through; second, adsorbing Th on a 1 mL AG1x8 resin bed in 8 M HNO{sub 3} and then eluting it with 9 M HCl followed by 0.1 M HCl + 0.005 M HF; and third, by passing the Th through a final 1.0 mL AG1x8 resin bed in 9 M HCl. The mass spectrometry is performed using the procedure 'Th and U Mass Spectrometry for {sup 230}Th-{sup 234}U Age Dating'.

We used short lived {sup 239}Np as a yield tracer and state of the art magnetic sector ICP-MS to measure ultra low levels of {sup 237}Np in a number of 'hot wells' at the Nevada National Security Site (NNSS), formerly known as the Nevada Test Site (NTS). The results indicate that {sup 237}Np concentrations at the Almendro, Cambric, Dalhart, Cheshire and Chancellor sites, are in the range of 3 x 10{sup -5} to 7 x 10{sup -2} pCi/L and well below the MCL for alpha emitting radionuclides (15 pCi/L) (EPA, 2009). Thus, while Np transport is believed to occur at the NNSS, activities are expected to be well below the regulatory limits for alpha-emitting radionuclides. We also compared {sup 237}Np concentration data to other radionuclides, including tritium, {sup 14}C, {sup 36}Cl, {sup 99}Tc, {sup 129}I, and plutonium, to evaluate the relative {sup 237}Np transport behavior. Based on isotope ratios relative to published unclassified Radiologic Source Terms (Bowen et al., 1999) and taking into consideration radionuclide distribution between melt glass, rubble and groundwater (IAEA, 1998), {sup 237}Np appears to be substantially less mobile than tritium and other non-sorbing radionuclides, as expected. However, this analysis also suggests that {sup 237}Np mobility ismore » surprisingly similar to that of plutonium. The similar transport behavior of Np and Pu can be explained by one of two possibilities: (1) Np(IV) and Pu(IV) oxidation states dominate under mildly reducing NNSS groundwater conditions resulting in similar transport behavior or (2) apparent Np transport is the result of transport of its parent {sup 241}Pu and {sup 241}Am isotopes and subsequent decay to {sup 237}Np. Finally, measured {sup 237}Np concentrations were compared to recent Hydrologic Source Term (HST) models. The 237Np data collected from three wells in Frenchman Flat (RNM-1, RNM-2S, and UE-5n) are in good agreement with recent HST transport model predictions (Carle et al., 2005). The agreement provides confidence in the results of the predictive model. The comparison to Cheshire HST model predictions (Pawloski et al, 2001) is somewhat ambiguous due to the low concentration resolution of the particle transport model.« less

The effect of temperature on the intensity of X-ray reflexion by gold, copper and aluminium has been studied by making microphotometric measurements on lines in X-ray structure spectra obtained with powder specimens in a Debye-Scherrer camera. A special method was employed to make cylindrical powder specimens, 0.8 mm. in diameter, which held together without adhesive and were free from a core of foreign material. The primary beam was standardized by means of a flat-plate X-ray camera, furnished with a plate of powdered gold which provided a spectrum whose lines could be accurately measured. The powder specimen under investigation was maintained in vacuo at temperatures ranging up to about 900° K, and its temperature estimated from lattice parameter measurements. The observed fall in intensity of X-ray reflexion by gold and copper as the temperature is raised up to about 900° K can be accounted for if the characteristic temperature varies with temperature in accordance with the relation θ T = θ 1 [1 ─ αγ( T ─ T 1 )], where θ T and θ 1 are the characteristic temperatures at temperatures T and T 1 , α is the cubical coefficient of thermal expansion and γ is the Grȕneisen constant. This relation is found to hold also for aluminium up to about 600° K. Beyond 600° K the fall of intensity exceeds that to be expected from the above relation, and it is suggested that another factor becomes prominent in the case of aluminium at the higher temperatures. The characteristic temperatures of gold, copper and aluminium now found by X-ray measurement at different temperatures, agree with the values obtained at those temperatures by specific heat and electrical conductivity methods.

In 2004, a borehole was drilled into the 1983 Chancellor underground nuclear test cavity to investigate the distribution of radionuclides within the cavity. Sidewall core samples were collected from a range of depths within the re-entry hole and two sidetrack holes. Upon completion of drilling, casing was installed and a submersible pump was used to collect groundwater samples. Test debris and groundwater samples were analyzed for a variety of radionuclides including the fission products {sup 99}Tc, {sup 125}Sb, {sup 129}I, {sup 137}Cs, and {sup 155}Eu, the activation products {sup 60}Co, {sup 152}Eu, and {sup 154}Eu, and the actinides U, Pu, and Am. In addition, the physical and bulk chemical properties of the test debris were characterized using Scanning Electron Microscopy (SEM) and Electron Microprobe measurements. Analytical results were used to evaluate the partitioning of radionuclides between the melt glass, rubble, and groundwater phases in the Chancellor test cavity. Three comparative approaches were used to calculate partitioning values, though each method could not be applied to every nuclide. These approaches are based on: (1) the average Area 19 inventory from Bowen et al. (2001); (2) melt glass, rubble, and groundwater mass estimates from Zhao et al. (2008); and (3) fission product mass yield data from England and Rider (1994). The U and Pu analyses of the test debris are classified and partitioning estimates for these elements were calculated directly from the classified Miller et al. (2002) inventory for the Chancellor test. The partitioning results from this study were compared to partitioning data that were previously published by the IAEA (1998). Predictions of radionuclide distributions from the two studies are in agreement for a majority of the nuclides under consideration. Substantial differences were noted in the partitioning values for {sup 99}Tc, {sup 125}Sb, {sup 129}I, and uranium. These differences are attributable to two factors: chemical volatility effects that occur during the initial plasma condensation, and groundwater remobilization that occurs over a much longer time frame. Fission product partitioning is very sensitive to the early cooling history of the test cavity because the decay of short-lived (t{sub 1/2} < 1 hour) fission-chain precursors occurs on the same time scale as melt glass condensation. Fission product chains that include both volatile and refractory elements, like the mass 99, 125, and 129 chains, can show large variations in partitioning behavior depending on the cooling history of the cavity. Uranium exhibits similar behavior, though the chemical processes are poorly understood. The water temperature within the Chancellor cavity remains elevated (75 C) more than two decades after the test. Under hydrothermal conditions, high solubility chemical species such as {sup 125}Sb and {sup 129}I are readily dissolved and transported in solution. SEM analyses of melt glass samples show clear evidence of glass dissolution and secondary hydrothermal mineral deposition. Remobilization of {sup 99}Tc is also expected during hydrothermal activity, but moderately reducing conditions within the Chancellor cavity appear to limit the transport of {sup 99}Tc. It is recommended that the results from this study should be used together with the IAEA data to update the range in partitioning values for contaminant transport models at the Nevada National Security Site (formerly known as the Nevada Test Site).

This procedure gives the methods used at LLNL for the purification of uranium and plutonium from bulk environmental samples provided by the IAEA through the DOE Network of Analytical Laboratories (NWAL).

This procedure is written as general guidance for the measurement of elemental isotopic composition by plasma-source inorganic mass spectrometry. Analytical methods for uranium and plutonium are given as examples.

Synthetic ion beams with instantaneous and temporal characteristics appropriate to thermal ionization mass spectrometry (TIMS) were mathematically generated and analyzed to determine the effects of using a mixed {sup 233}U-{sup 236}U spike (double-spike) in the analysis of uranium isotopes. The instantaneous beam characteristics are the intensities (e.g., counts per second) modeled with a Poisson distribution plus a component of random noise that simulates the detection processes. Several beam intensity and mass fractionation vs. time functions were modeled to simulate a range of sample sizes and the commonly employed methods of data collection. These beam profiles were also generated with different noise levels, and signal-to-noise vs. analytical precision diagrams are presented. Modeling focused on natural uranium, where {sup 238}U/{sup 235}U = 137.88, and on the ability of a given method to determine precisely and accurately small variations in this ratio. Practical limits on precision were determined to be 20-30 ppm, which is consistent with precision seen for other elements by state-of-the-art TIMS. The TIMS total evaporation method was compared directly with the double-spike method. While similar analytical precisions are obtained with either method, the double-spike method of correcting for analytical bias gives more accurate results. The results of a total evaporationmore » analysis will deviate from true by more than the analytical precision if as little as 0.05% of the signal is not integrated, whereas the accuracy and precision of the double-spiked analyses are always linked.« less

Natural inorganic colloids (< 1 micron particles) found in groundwater can sorb low-solubility actinides and may provide a pathway for transport in the subsurface. For example, Kerting et al found that Pu, associated with colloids fraction of the groundwater, was detected over 1 km away from the underground nuclear test at the Nevada Test Site (NTS) where it was originally deposited 28 years earlier. However, laboratory experiments have not identified the mechanisms by which Pu may sorb to colloids or exist as its own colloid and travel relatively unimpeded in the subsurface. Some data suggest that Pu sorption to colloids is a very fast process while desorption is very slow or simply does not occur. Slow desorption of Pu from colloids could allow Pu sorbed to a colloid to travel much farther than if sorption were an equilibrium process. However, PU sorption (and particularly desorption) data in the literature are scant and sometimes contradictory. In some cases, Pu desorption is rather fast, with rates dependent on colloid mineralogy. Moreover, the effect of sorption and desorption kinetics (as well as other mechanisms) on colloid-facilitated transport at the field scale has not been thoroughly evaluated. This is, in part, due to limitationsmore » in colloid transport as well as sorption/desorption models.« less

Objective:\ud To investigate the efficacy and safety of ulipristal acetate (UPA) for long-term treatment of symptomatic uterine fibroids.\ud \ud Design:\ud Repeated intermittent open-label UPA courses, each followed by randomized double-blind norethisterone acetate (NETA) or placebo.\ud \ud Setting:\ud European clinical gynecology centers.\ud \ud Patient(s):\ud Two hundred and nine women with symptomatic fibroids including heavy menstrual bleeding.\ud \ud Intervention(s):\ud Patients received up to four 3-month courses of UPA 10 mg daily, immediately followed by 10-day double-blind treatment with NETA (10 mg daily) or placebo.\ud \ud Main Outcome Measure(s):\ud Amenorrhea, fibroid volume, endometrial histology.\ud \ud Result(s):\ud After the first UPA course, amenorrhea occurred in 79% of women, with median onset (from treatment start) of 4 days (interquartile range, 2–6 days). Median fibroid volume change was −45% (interquartile range, −66%; −25%). Amenorrhea rates were 89%, 88%, and 90% for the 131, 119, and 107 women who received treatment courses 2, 3, and 4, respectively. Median times to amenorrhea were 2, 3, and 3 days for treatment courses 2, 3, and 4, respectively. Median fibroid volume changes from baseline were −63%, −67%, and −72% after treatment courses 2, 3, and 4, respectively. All endometrial biopsies showed benign histology without hyperplasia; NETA did not affect fibroid volume or endometrial histology.\ud \ud Conclusion(s):\ud Repeated 3-month UPA courses effectively control bleeding and shrink fibroids in patients with symptomatic fibroids.

Sir, We describe a case of progressive visual loss following ingestion of excessive amounts of Indian tonic water in a patient unduly sensitive to quinine. Although acute quinine amblyopia is well recognised, there are no reports of chronic toxicity, and we discuss current ideas on the pathophysiology of quinine on the retina. Case Report A 46-year-old man noticed increasing visual deterioration and difficulty with night driving over 3 months. His visual acuity measured OD 6/24 OS 6/12 with no refractive error. Pupillary responses and tonometry were normal, but tritanomaly was apparent with the City University colour vision test. Retinal vessels were of normal calibre but each macula exhibited fine stippling shown by fluorescein angiography to be at the level of the pigment epithelium (Fig. 1). The previous medical history included a period of alcohol abuse successfully treated with disulfiram for 3 years. The patient was non-smoker and his diet appeared satisfactory. For 12 months prior to presentation he was drinking 4 litres of tonic water each day. Physical examination was normal as was the body mass index. Normal investigations included the following: routine haematology, ESR, autoantibody screen, vitamin B12 and folate studies, and routine biochemistry. A random blood alcohol level was negative and CT scanning of the orbits and anterior visual pathways was normal. ELISA testing for HIV was also conducted, and this too was negative. Plasma quinine was detected at 0.5 mg/1 (therapeutic range 0.5-8.0 mg/1) 2 days after presentation. An electrodiagnostic investigation could not be undertaken until some weeks after presentation. The electro-oculogram (EOG) and full field electroreti-nogram (ERG) were normal, making a generalised retinal disorder unlikely. Pattern ERG showed a normal P50 in each eye but possible diminution of N95 bilaterally. Transient visual evoked responses were abnormally delayed (Fig. 2) and no steady-state response could be obtained. A diagnosis of quinine toxicity was made on the history and electrodiagnostic evidence for a bilateral retinal disorder. The patient was advised to stop drinking tonic water and there was a steady visual improvement. One month after presentation acuities were OD 6/18 OS 6/6 and within 6 months all visual parameters were normal. A 4 year follow-up has revealed no further episodes of blindness and good intercurrent health. Discussion Blindness following quinine ingestion is usually an acute event after deliberate self-poisoning1 or treatment for chloroquine-resistant Falciparum malaria.2 Visual loss from chronic ingestion of quinine at recommended doses has not previously been described, although a regular daily intake of 120 mg provoked electronystagmograpMc abnormalities in healthy volunteers, whilst 160 mg produced red/green dyschromatopsia.3 Tonic water contains 80 mg/1 quinine sulphate and a daily consumption of 4 litres is equivalent to the advised daily dose of quinine for leg cramps (300 mg). Justification for quinine as a toxin relates to its regular intake at therapeutic levels and visual recovery following its withdrawal. There were abnormal electrodiagnostic features possibly indicating outer retinal disease, but no evidence for alcoholic or nutritional amblyopia. The macular abnormalities, possibly at the level of the retinal pigment epithelium (RPE), may represent deposition of quinine. Like chloroquine, quinine binds to uveal tissue in vitro4 and Dekking5 describes pigmentary abnormalities in a case of acute quinine poisoning. A carefully documented case1 of acute quinine toxicity found evidence for an acute direct effect upon the photoreceptor cell layer and outer retina. The decreased light EOG rise in acute poisoning has suggested involvement at the RPE/photoreceptor level, while the initially normal flash ERG implied damage to the ganglion cell layer. Recent case reports6'7 which review the literature have suggested electrophysiological evidence for damage in all retinal layers. Quinine appears to have deleterious effects at both the RPE/photoreceptor interface (low EOG) and inner retina, possibly at the level of bipolar cells (decreased or absent ERG b wave). In chronic toxicity there appears to be a similar although reversible sequence of effects. We are presuming the macula to be the most sensitive to chronic toxicity as indicated by the abnormal pattern ERG N95 wave and presence of pigmentary macular features. Peripheral retina appears unaffected as shown by the normal flash ERG and EOG (whole retinal responses). Other causes for visual loss were considered. Tobacco-alcohol amblyopia was unlikely in the absence of measurable plasma alcohol and with normal liver function. Demyelination is unusual in this age group and bilateral optic neuritis extremely rare. Additionally, we felt the time course of blindness was unusually protracted for demyelination and to date there have been no further episodes of neurological deficit. We conclude that an investigation of blindness must include a careful dietary history and that idiosyncratic sensitivity may occur to commonly well-tolerated substances including quinine. The authors acknowledge the expert advice provided by Mr John Kelsey, FRCS, Electrodiagnostic Department, Moorfields Eye Hospital.

A thin-film technique has been developed for the quantitative analysis of grindable solids such as combustion chamber and spark-plug deposits, coal and fuel-oil ashes, sediments and catalysts. Only 20 mg of sample are required and results are virtually independent of the matrix for all elements of atomic number 11 (Na) and heavier. Detection limits for the 25 elements so far calibrated range betweenf 0.05 and 1.0% by weight. The technique was proved using 22 certified materials, the precision being within 10% relative over much of the calibration ranges.

Raman spectra have been measured of the following samples: active calcium pump protein in light sarcoplasmic reticulum (SR) membranes, lipids extracted from light SR membranes, active calcium pump protein reconstituted in dielaidoylphosphatidylcholine (DEPC), and pure DEPC. The spectra of native SR lipids and of pure DEPC are different, and yet when these spectra are subtracted from the spectra of the respective protein-lipid complexes, the resulting amide I spectra of the calcium pump protein are the same, indicating that appropriate criteria have been chosen for subtraction of the spectrum of a lipid. This spectrum has been analyzed for secondary structure with the following results. The SR calcium pump protein contains 51 +/- 5% helix, in agreement with a prediction of secondary structure obtained from an analysis of the sequence, and 21 +/- 4% beta-strand. In addition, the presence of protein broadens and lowers the main melting transition of DEPC.

Donnees theoriques et cas des micelles de lauryl sulfate de Na contenant de l'alcool benzylique, dans un grand domaine de concentrations

Raman spectra were taken of human alpha (leukocyte) interferon subtype A (HuIFN-alpha A) purified from extracts of transformed Escherichia coli. Quantitative analysis of the conformationally sensitive amide I band indicates that IFN (interferon)-alpha A is 75 +/- 5% helical and 7 +/- 4% beta-strand. An independent analysis of the amide III spectrum indicates 71 +/- 5% helix and 10 +/- 6% beta-strand. These results differ with a recently proposed three-dimensional model based on secondary structure predictions derived from sequence and with circular dichroism measurements. The Raman spectrum of IFN-alpha A is compared with the spectra of several other helical proteins: hemerythrin, intestinal calcium-binding protein, melittin, and insulin.

Calsequestrin has been precipitated with calcium into five different crystal forms: cruciform twins, flat rectangles, thin needles, bipyramids, rectangular prisms, and a sixth precrystalline form, spheres. Raman spectra of the spheres and the cruciform twins are the same. The Raman spectrum of a physiological concentration (10%) of calsequestrin in calcium-free solution is the same as the spectrum of calcium precipitated calsequestrin in the amide I region, and in the C-C stretching region, but these spectra are different in the amide III region. The Raman spectrum of unfolded calsequestrin in 5 M guanidine hydrochloride is quite different from the other spectra, but it is not similar to the spectra of other unfolded proteins. Estimates of secondary structure from the amide I region indicate that calsequestrin in calcium-free solution and calcium-precipitated forms has 40 +/- 5% helix, 30 +/- 4% beta-strand, and 18 +/- 2% reverse turn. Secondary structure estimates calculated from the amide III region are not significantly different. They indicate 41 +/- 5% helix and 36 +/- 6% beta-strand for the precipitated forms, and 32 +/- 5% helix and 39 +/- 6% beta-strand for solutions. Calsequestrin unfolded in 5 M guanidine hydrochloride at 100 mg/ml gives 24 +/- 5% helix and 48 +/- 6% beta-strand.

Electronic densities of states functions are calculated for the random substitutional alloy system Ag-Pd for a number of compositions across the complete range of concentrations. The calculations are based on the coherent potential approximation. It was found necessary to extend the simple model Hamiltonian method previously used to describe Cu-Ni alloys because of the stronger dependence of the lattice constant on composition in the Ag-Pd system. It is shown that the results are consistent with published photoemission and optical absorption data, and low temperature specific heat and Pauli spin susceptibility experiments. The possibility of s-d charge transfer in this alloy system is discussed.

The distance of a radio source can be determined from its absorption spectrum produced by interstellar neutral hydrogen. Three methods have been used to obtain a distance from these data. It can be decided where any source lies within the Galaxy or whether it is extragalactic. A method is also described for obtaining the kinetic temperature of interstellar neutral hydrogen from absorption and emission spectra. The Cygnus source was found to be extragalactic, the Cassiopeia source appears to lie at a distance of between 2.5 and 5.5 kiloparsecs; while the Sagittarius source is about 3 kiloparsecs from the sun in the direction of the galactic centre.

The mass spectrum of dimuons produced by 400 GeV/c protons in Tungsten has been measured for masses greater than 7 GeV. A clear resonant signal of 2700 upsilons has been seen. The dependence of dimuon production on xF and pT has been determined for dimuon masses in the range 7.0 to 8.25 GeV as well as for masses in the upsilon region 8.25 to 9.75 GeV.

The NA34 (HELIOS) calorimeter has measured e/{pi} {congruent} 1.1 in a uranium/liquid argon calorimeter with a shaping time of 135 nsec. Lead may be a viable alternative, but e/{pi} must first be measured at fast shaping times in lead. We re preparing to measure e/{pi} at momenta ranging from 0.5 to 20 GeV/c and with shaping times of 50, 100 and 150 nsec.

A search has been made for the 1(10)-- 1(11) transition of thioformaldehyde in interstellar clouds where formaldehyde is known to exist. Failure to detect this transition indicates that the ratio of thioformaldehyde abundance to that of formaldehyde is probably less than the abundance ratio of sulfur to oxygen.

High-resolution ground-based measurements have been made of the J = 0 → 1 and the J = 1 → 2 rotational transitions of carbon monoxide in the earth’s atmosphere. These transitions, which occur at frequencies near 115 and 230 GHz, were observed in absorption against the solar continuum. The two absorption profiles have been used to derive the CO mixing ratio as a function of altitude between 50 and 80 km in the atmosphere.

Observations of the J=2-1 and J=1-0 rotational transitions of /sup 12/CO, /sup 13/CO, and C/sup 18/O are reported for 10 molecular clouds. An analysis of the data based on a large-velocity-gradient cloud model suggests that in most of these sources the average molecular hydrogen densities lie between 2000 and 8000 cm/sup -3/, while /sup 13/CO fractional abundances are approximately 3 x 10/sup -6/. These hydrogen densities are typically a factor of 10 lower than those inferred from observations of other molecules such as HCN, CS, or H/sub 2/CO; possible explanations for this discrepancy are discussed.