Energy Technology Data Exchange (ETDEWEB)

High-spin states in {sup 202}Pb and {sup 203}Pb have been investigated by in-beam {gamma}-ray spectroscopy following the reaction {sup 198}Pt({sup 9}Be,xn). A search for magnetic rotational bands in these isotopes confirmed one of the two bands previously assigned to {sup 202}Pb and revealed a new band in this isotope. No evidence for magnetic rotation has been found in {sup 203}Pb. (orig.)

Energy Technology Data Exchange (ETDEWEB)

A simple highly efficient procedure has been developed for recovery of thallium radioisotopes from lead and bismuth targets irradiated by 1-GeV protons. The procedure is based on the use of extraction chromatography. The cross-sections have been determined for formation of {sup 200}Pb, {sup 201}Pb, {sup 202m}Pb, and {sup 203}Pb radioisotopes in targets from lead with natural isotopic composition, irradiated by 1-GeV protons.

British Library Electronic Table of Contents (United Kingdom)

Abstract The Jebel Ressas Pb-Zn deposits in North-Eastern Tunisia occur mainly as open-space fillings (lodes, tectonic breccia cements) in bioclastic limestones of the Upper Jurassic Ressas Formation and along the contact of this formation with Triassic rocks. The galena-sphalerite association and their alteration products (cerussite, hemimorphite, hydrozincite) are set within a calcite gangue. The Triassic rocks exhibit enrichments in trace metals, namely Pb, Co and Cd enrichment in clays and Pb, Zn, Cd, Co and Cr enrichment in carbonates, suggesting that the Triassic rocks have interacted with the ore-bearing fluids associated with the Jebel Ressas Pb-Zn deposits. The 18O content of calcite associated with the Pb-Zn mineralization suggests that it is likely to have precipitated from a fl...

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

Presently available relativistic and nonrelativistic effective interactions do not predict the same behavior for the isotope shifts in the Pb region.We analyze this difference and find that it is related to the characteristics of the spin-orbit term used in the parametrizations. We show that a simple modification of the spin-orbit contribution to the nonrelativistic Skyrme functional solves this problem. ((orig.))

International Nuclear Information System (INIS)

Radioisotopes of Pb(II) have been of some interest in radioimmunotherapy and radioimmunoimaging (RII). However, the absence of a kinetically stable bifunctional chelating agent for Pb(II) has hampered its use for these applications. "2"0"3Pb (T_1_/_2=52.02 h) has application potential in RII, with a #gamma#-emission that is ideal for single photon emission computerized tomography, whereas "2"1"2Pb (T_1_/_2=10 h) is a source of highly cytotoxic #alpha#-particles via its decay to its "2"1"2Bi (T_1_/_2=60 min) daughter. The synthesis of the novel bifunctional chelating agent 2-(4-isothiocyanotobenzyl)-1,4,7,10-tetraaza-1,4,7,10-tetra-(2-carbamoyl methyl)-cyclododecane (4-NCS-Bz-TCMC) is reported herein. The Pb[TCMC]"2"+ complex was less labile to metal ion release than Pb[DOTA]"2"- at pH 3.5 and below in isotopic exchange experiments. In ...

Energy Technology Data Exchange (ETDEWEB)

A study was undertaken to examine the uptake, distribution, and interaction of five activation products (Co-57, Be-7, Cs-134, Rb-83, and Mn-54) within the biotic and abiotic components surrounding the waste treatment lagoons of the Los Alamos Meson Physics Facility (LAMPF). The study attempted to ascertain where, and what specific interactions were taking place among the isotopes and the biotic/abiotic components. A statistical approach, utilizing Multivariate Analysis of Variance (MANOVA), was conducted testing the radioisotopic concentrations by (1) the trophic levels (TROPLVL) in each position sampled on the grid, (2) where sampled on the grid (TRAN), (3) where sampled with-in each grid line (PLOT), and (4) the side with which sampled (SIDE). This provided both the dependent and independent variables that would be tested. The Null Hypothesis (Ho) tested the difference in the mean values of the isotopes within/between ...

International Nuclear Information System (INIS)

A review is presented of the literature through 1977 on the uses of radioactive lead isotopes in metabolic studies in man, animals, and plants. These studies have been done mainly with the naturally-occurring, long-lived (22-yr half life) "2"1"0Pb, but a few were with 53-hr "2"0"3Pb or 10.6-hr "2"1"2Pb. Such studies have made possible estimates of the metabolic parameters of lead in man and animals, such as intestinal absorption, the ratio of fecal-to-urinary excretion of endogenous lead, residence time of lead in the body and in various organs, and the distribution in the body (skeleton, liver, kidney, and blood). Subsequently, these parameters and data have been used to trace the sources of lead for man, such as those from the atmosphere, food, cigarette smoke, and automobile exhaust.

International Nuclear Information System (INIS)

This is one of an annual collection of reports presenting data from the Geochronology Section of the Continental Geoscience Division of the Geological Survey of Canada (GSC). The main purpose of this collection is to make geochronological and other radiogenic isotope data produced by the section available promptly to the geological community. Reports make full presentation of the data, relate these to field settings and make comparatively short interpretations. Other geochronological and isotope data produced in the laboratory but published in outside journals or separate GSC publications are summarized at the end of this report. Report 5 contains 24 papers from most regions of Canada, but particularly from British Columbia. The Geochronology Laboratory has, over the years, provided substantial U-Pb dating for the Cordilleran Division of the Geological Survey of Canada in Vancouver, and the results of a number of these ...

Energy Technology Data Exchange (ETDEWEB)

The generalized hybrid derivative coupling model has been applied to explore various ground state properties of different nuclei. In this work we have confined our calculation only to the model characterized by the hybridization parameter {alpha} = 1/4 which gives better results than the other models of the same class, as we have seen earlier, for nuclear matter calculations. The binding energy, single-particle energy spectra, density and charge radii of different doubly closed nuclei like {sup 16}O, {sup 40}Ca, {sup 48}Ca, {sup 90}Zr, {sup 132}Sn, {sup 208}Pb have been studied. The success of this model, in describing the doubly closed nuclei, motivates us to extend this calculation further in the case of open shell nuclei after incorporating the pairing interaction and using a BCS transformation. We have calculated the binding energy for such nuclei. We have also studied the isotopic shift for different Pb ...

International Nuclear Information System (INIS)

Remotely-operated SHRIMP dating of zircon is an interesting alternative for dating of zircon crystals. Although it does not represent any technical progress of the geochronological method using the U-Pb system in zircon it is a very useful and cheap facility. The procedure was first used for mass spectrometric analyses involving two international laboratories in Sao Paulo, Brazil and Beijing, China. It was applied to samples of three gneiss-migmatitic rocks from the Ita quarry in the Atuba Complex (located between the Luis Alves and the Apiai Domain) to test previous controversial hypotheses about its evolution. The presence of important archaean and paleo proterozoic components in the complex is confirmed by analyses of zircon found in probably neo proterozoic leucosomes. Diorite intrusion also occurred during the neo proterozoic, associated with the 0.6Ga continental collisions involved in the assembly of Gondwana. The determination of Hf ...

International Nuclear Information System (INIS)

Tumor-targeted monoclonal antibodies (mAb) might be useful as diagnostic or therapeutic agents when linked to cytotoxic or imaging reagents. Our group is working to test this hypothesis by linking cytocidal and image-producing isotopes to mAb and testing the utility of the radioimmunoconjugates formed in animal model systems. Radioiodines were first employed for these purposes,but unfavorable nuclear properties (half-lives, #gamma#-ray and #beta#-particle energies) and chemical reactivity (deiodination in vivo) limit their utility. Labeling immunoproteins with metallic radionuclides offers more versatility in that the selection of potentially useful radiometals spans the periodic table.Of the metallic radionuclides with physical properties most suited for use with mAb in nuclear medicine, few are more available or desirable than those of bismuth ("2"1"2Bi) and lead ("2"0"3Pb, "2"1"2Pb), as listed in Table 1. "2"1"2Bi or ...

Energy Technology Data Exchange (ETDEWEB)

Nuclear Hartree-Fock (HF) + BCS calculations have led to predictions of shape isomerism in isotopes of Pt, Hg and Os nuclei. These have been confirmed through the observation of superdeformed rotational bands in {sup 190,{hor ellipsis},194}Hg. Encouraged by these measurements and similar observations in {sup 194}Pb, we have extended these calculations to a wide range of contiguous nuclei. These HF results, for {sup 192,194}Pt, {sup 190,{hor ellipsis},198}Hg and {sup 194}Pb, have been employed in a Generator Coordinate Method (GCM) calculation utilizing the quadrupole deformation as the generating variable. The resulting spectra confirm the conclusions drawn from the HF results and agree with those experiments which have been performed. Adding a phenomenological assumption for the moments of inertia of our GCM states, we can construct the radiative transitions within and out of the superdeformed band. The results are in good ...

Energy Technology Data Exchange (ETDEWEB)

The high selectivity of 201 MeV inelastic proton scattering at forward angles for exciting ..delta..L=0 spin flip transitions is outlined by comparison with (e,e') and 65 MeV (p,p') measurements. A summary of the results obtained on the calcium isotopes, the N=28 isotones, /sup 88/Sr and /sup 90/Zr is presented. The differences in the relative M1 strength distributions between the (p,p') and the (e,e') results are discussed. Preliminary results on /sup 208/Pb are given; the ''isoscalar'' 1/sup +/ state at 5.846 MeV is excited.

Energy Technology Data Exchange (ETDEWEB)

Several reactions producing odd-Z transactinide compound nuclei were studiedwith the 88-Inch Cyclotron and the Berkeley Gas-Filled Separator at the LawrenceBerkeley National Laboratory. The goal was to produce the same compound nucleus ator near the same excitation energy with similar values of angular momentum via differentnuclear reactions. In doing so, it can be determined if there is a preference in entrancechannel, because under these experimental conditions the survival portion of Swiatecki, Siwek-Wilcznska, and Wilczynski's"Fusion By Diffusion" model is nearly identical forthe two reactions. Additionally, because the same compound nucleus is produced, theexit channel is the same. Four compound nuclei were examined in this study: 258Db, 262Bh, 266Mt, and 272Rg. These nuclei were produced by using very similar heavy-ion induced-fusion reactions which differ only by one proton in the projectile or target nucleus (e.g.: 50Ti + 209Bi vs. 51V + ...

British Library Electronic Table of Contents (United Kingdom)

Mediterranean mariculture uses imported strains of marine phytoplankton, raising questions of ecological risk and ability to adapt to local conditions for mass culture outdoors. In this context, we report here on the mass-culture potential and chemical composition of six strains of Prasinophyceae (five strains of Tetraselmis sp. and one Pyramimonas sp.) isolated from a Greek coastal lagoon. Proximate composition had a pattern of 10?20% ash, 35?65% protein, 6?10% lipids, and 25?45% other organics including carbohydrates. The amino acid profiles were typical for the marine representatives of the class. All strains had a high PUFA content with dominant the ?3 fraction in four of them. The fatty acid profiles indicated a Tetraselmis strain with high EPA (14%) and a Pyramimonas strain with high...

International Nuclear Information System (INIS)

As human activity in and around Puget Sound increased, so did the contaminant levels in the sediment. Sediment cores collected in 1 982 revealed inputs of chemicals to the Sound, including lead (Pb), mercury (Hg), silver (Ag), copper (Cu) and petroleum hydrocarbons, began to increase above background in the late 1800s and peaked between 1945 and 1965. Synthetic organic compounds, such as polychlorinated biphenyls (PCBs) and DDT, first appeared in sediments deposited in the 1930s and reached a maximum in the 1960s. The presence of the subsurface maximum concentrations suggests that pollution-control strategies have improved the sediment quality of central Puget Sound. Additional sediment coring was performed in 1991 and samples were collected at six locations in the main basin of Puget Sound. Sediment ages were determined using Pb"2"1"0 radio isotope dating. Sedimentation rates were approximately 1 to 2 cm/yr and deposition ...

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

Short note.

Energy Technology Data Exchange (ETDEWEB)

Brief item.

Science.gov (United States)

The experimental work completed thus far in the areas of rapid radiochemical separations and metastable isomeric states is summarized. Activation analyses were made in samples of ore materials and metals using rapid radiochemical separations to isolate short-lived radioactive isotopes such as 3.77-min V/sup 52/ and 14.6-min Mo/sup 101/. The analytical results obtained were compared to the results obtained from standard chemical and instrumental analytical methods and, where possible, to activation analysis results obtained from longer-lived isotopes of the same element. Further work is in progress to improve the procedures, to evaluate the reproducibility and accuracy of the methods, and to evaluate their usefulness on a wide variety of sample matrices. The research on short-lived metastable isomers showed that 1.7-min W/sup 185m/ is not produced in sufficiently high yield for the development of a supplementary ...

Energy Technology Data Exchange (ETDEWEB)

Reservoir geometry reconstruction within carbonate platforms has been carried out in the Upper Jurassic of the Paris Basin based on high-resolution sequence stratigraphy correlations (cores and well-logs). 18 cored wells over 25 kM{sup 2} have been correlated (Saint-Clair-sur-Epte field, Gaz de France). During lower and middle Oxfordian the Paris Basin is a carbonate platform prograding southward. This progradational trend can be subdivided into three upper order sequences (parasequences sets, mean duration: one m.y.). The lower parasequence-set is a stacking of shallowing-upward parasequences made up of tidal ooids bars surrounded laterally and backward by more protected environments (large variety of coated grains). The middle parasequence-set is recorded in lagoonal environments with numerous channels and lobes of storm washover-fans. Metric-thick sequences have been correlated over the field. They are ernersive upward (subtidal lagoonal ...

International Science & Technology Center (ISTC)

Development of a Plant for Neon Isotopes Separation by Low-Temperature Rectification Method

International Nuclear Information System (INIS)

Discordant U-Pb zircon isotopic data from amphibolite facies orthogneisses of the Charleston Metamorphic Group, western South Island, New Zealand, define a lower intercept age of 114#+-#18 m.y. that is interpreted as the crystallization age of the orthogneiss magmas. The upper intercept age of 1026#+-#97 m.y. reflects inherited components of Precambrian zircon derived from the source region of the magmas. The age, and whole rock chemical characteristics, indicate that the orthogneisses are part of the same phase of Early cretaceous magmatic activity that produced voluminous arc-related calc-alkaline plutonic rocks throughout western South Island. Previously published K-Ar and Rb-Sr mineral ages indicate uplift and cooling of the Charleston Metamorphic Group to less than 400deg C by 110-90 m.y. This uplift occurred as a consequence of low-angle normal faulting related to the Late Cretaceous breakup of Gondwana, and suggests that regional ...

International Nuclear Information System (INIS)

The Median Tectonic Zone (MTZ) of New Zealand is a generally north trending belt of Mesozoic subduction related I-type plutonic, volcanic, and sedimentary rocks in South Island and Stewart Island that separates Permian strata of the Eastern Province Brook Street Terrane from lower to mid Gondwana margin assemblages of the Western Province. High precision isotope dilution U/Pb ages of zircons from 30 rocks are reported. Pre-digestion leaching of zircon in hydrofluoric acid yielded significantly more concordant residues by removing common Pb and dissolving more soluble high-U domains that have been more affected by relatively recent Pb loss. The results show that MTZ magmatism ranges in age from at least Early Triassic to Early Cretaceous (247-131 Ma), with a pronounced gap in the Middle Jurassic. Triassic plutons tend to occur on the eastern side of the MTZ, and they intrude volcanic/sedimentary ...

Energy Technology Data Exchange (ETDEWEB)

The NA50 Collaboration has recently observed a strong suppression of {ital J}/{psi} production in Pb-Pb collisions at 158GeV/nucleon. We show that this recent observation finds a quantitative explanation in a model which relates the suppression mechanism to the local energy density, whose value is higher in Pb-Pb collisions than in any other system studied previously. The sensitivity of the phenomenon to small changes in the energy density could be suggestive of quark-gluon plasma formation. {copyright} {ital 1996 The American Physical Society.}

Energy Technology Data Exchange (ETDEWEB)

The majority of experimental and population studies of blood lead (PbB) and environmental lead, including the Omaha study, have utilized the Goldsmith-Hexter log-log or power function model. Comparison was made of the log-log model and a linear model of total exposure as they described the Omaha Study of 1074 PbBs from children ages 1-18 years as related to air (PbA), soil (PbS), and housedust (PbHD) lead. The data fit of the linear model was statistically equivalent to the power model and the predicted curves were biologically more plausible. The linear model avoids the mathematical limitations of the power model which predicts PbB zero at PbA zero. From the Omaha data, this model, ln PbB = ln (..beta../sub 0/ + B/sub 1/ PbA + B/sub 2/ PbS + ..beta../sub 3/ ...

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

International Science & Technology Center (ISTC)

Production of Radioactive Isotopes in Republic of Kasakhstan.

International Nuclear Information System (INIS)

... carrier-free isotopes chemical preparation gamma spectra isotope production

International Nuclear Information System (INIS)

Absorption of lead is known to be enhanced during infancy. In this study, the sites of intestinal accumulation of Pb by suckling rats have been determined under various conditions using "2"0"3Pb as a tracer. When "2"0"3Pb was administered intragastrically (IG) as a soluble salt, accumulation occurred primarily in the duodenum, regardless of dose and vehicle. In contrast, when rat pups suckled from a dam which had received "2"0"3Pb, the only region of the small intestine showing accumulation of radioactivity was the ileum. To confirm that these differences were not related to the route of administration, rat milk was labeled with "2"0"3Pb and was then used for IG administration. Once again, accumulation (4 hr post-administration) was confined to the ileum. When the dose was increased 10-fold, milk Pb displayed some accumulation in duodenal tissue, but very much ...

International Nuclear Information System (INIS)

... AND NUCLEAR MEDICINE biological localization cardiovascular diseases

Energy Technology Data Exchange (ETDEWEB)

With the ever increasing awareness of the toxicity of Pb, significant pressure has been put on the electronics industry to get the Pb out of solder. This work pertains to the development and characterization of an alloy which is Pb-free, yet retains the proven positive qualities of current Sn-Pb solders while enhancing the shortcomings of Sn-Pb solder. The solder studied is the Sn-4.7Ag-1.7Cu wt% alloy. By utilizing a variety of experimental techniques the alloy was characterized. The alloy has a melting temperature of 217{degrees}C and exhibits eutectic melting behavior. The solder was examined by subjecting to different annealing schedules and examining the microstructural stability. The effect of cooling rate on the microstructure of the solder was also examined. Overall, this solder alloy shows great promise as a viable alternative to Pb-bearing solders and, ...

International Nuclear Information System (INIS)

2,3-Dimercaptosuccinic acid (DMSA) is a new orally active heavy metal chelator for the treatment of childhood Pb intoxication on an outpatient basis. The influence of DMSA, as well as other chelating agents, on gastrointestinal 203Pb absorption and whole-body "2"0"3Pb retention was examined. Groups of Sprague-Dawley rats (230-260 g) were gavaged with a solution containing approximately 25 mg/kg Pb [as Pb(NO_3)2] plus 15 microCi "2"0"3Pb. Some groups were then immediately given 0.11 mmol/kg of either DMSA, CaNa2EDTA, D-penicillamine, or BAL by oral gavage, while other groups received the same drugs by ip injection. Control groups received solutions of the drug vehicles po or ip. Whole-body Pb retention and gastrointestinal Pb absorption (whole body retention + urinary Pb excretion) were significantly ...

International Nuclear Information System (INIS)

Fractionation of isotopes of the alkali metals and the alkaline earth metals in ion exchange chromatography of their chlorides was studied. The heavier isotopes of potassium and rubidium were found to be preferentially fractionated into the ion exchanger phase while the lighter isotopes of lithium, magnesium, calcium and strontium were enriched in the exchanger phase. This can be interpreted as a resultant of the relative significance of isotope effect upon dehydration and isotope effect accompanying the phase change of the hydrated metal ion. Found was no evidence of anomalous isotope effect attributable to the odd-even difference in mass number of isotopes. Based on the spectroscopic and solution chemical data (experimental and theoretical), the isotopic reduced partition function ratios of the hydrated alkaline metal ...

Energy Technology Data Exchange (ETDEWEB)

Adsorptive removal of Pb(II) ions from aqueous solution onto a non-activated charcoal (CC) of oak wood origin was studied in comparison with an activated carbon of coal origin. The adsorption capacity for Pb(II) of the non-activated charcoal increased significantly with deceasing particle diameter, whereas the activated carbon (AC) exhibited approximately constant capacity for Pb(II) adsorption as a function of particle size. Adsorption to the ashes prepared from the non-activated charcoal and the activated carbon was also investigated to examine the role of mineral ash. Although the ash from the activated carbon did not show any Pb(II) adsorption, the ash from the charcoal was very effective for Pb(II) adsorption. Furthermore, Pb(II) was hardly adsorbed when the ash was removed from the non-activated charcoal by acid treatment. Based on the results, the ...

International Nuclear Information System (INIS)

The concentrations of Cd, Co, Cr, Fe, Mo, Ni, Se, Ti, V and Zn in biological fluids, human blood serum and market milk were determined by neutron activation analysis, with enrichment by coprecipitation. The pre-concentration of these trace elements was accomplished by converting the dissolved trace metal ions into their pyrrolidinedithiocarbamate (1-pyrrolidinecarbodithioate) chelates, followed by coprecipitation with a metal carrier such as Ni, Pb or Bi. The coprecipitation was carried out prior to irradiation for the short-lived nuclides (V, Ti and Se) and after irradiation for the other elements. The validity of the method was checked using certified biological reference materials; the concentrations of trace elements found by the proposed method agreed well with the published certified data. The limits of detection for Cd, Co, Cr, Fe, Mo, Ni, Se (obtained through the long-lived isotope "7"5Se) and Zn under the present experimental ...

Energy Technology Data Exchange (ETDEWEB)

Bismuth radioisotopes, produced by 50-MeV proton bombardment of a lead target in a cyclotron, are separated from the lead target material by ion-exchange chromatography on a column containing 5.0 ml of Chelex 100. After a decay period of 24 hr, the /sup 203/Pb formed in situ is eluted from the column and then separated from /sup 200/Tl and /sup 201/Tl on a second ion-exchange column containing 0.5 ml of Chelex 100. Separations are sharp and carrier-free /sup 203/Pb is obtained.

International Nuclear Information System (INIS)

During the first and second quarters of 1994 air samples were collected and analyzed from 54 air particulate/halogen sampling stations, 10 noble gas sampling stations and 19 tritiated water vapor sampling stations. Surface water samples were collected and analyzed from 12 open water supply reservoirs, 8 natural springs, 2 wastewater containment ponds and 9 sewage lagoons. Groundwater samples were obtained brom 10 potable and 1 non-potable supply wells, and 8 drinking water consumption points. Ambient radiation levels were measured at 193 locations.

British Library Electronic Table of Contents (United Kingdom)

Purpose The mangroves of New Caledonia, in the south Pacific, act as a buffer between a lagoon of more than 20,000?km2 and the island, which is characterized by ultramafic rocks and lateritic soils that are exploited for their richness in heavy metals. We will provide a better understanding of the redox conditions, and of heavy metal distributions in mangroves receiving shrimp farm effluents. Materials and methods Samples were collected from four areas defined in terms of vegetation composition: a salt flat, an Avicennia marina forest, in which effluents are released; a Rhizophora stylosa forest, and a dead Rhizophora forest. They were collected during times of maximum effluent release. Some measurements on pore water were also done during a period without effluent. Cores (70?cm deep) were...

Energy Technology Data Exchange (ETDEWEB)

Separation of lithium isotopes was investigated by chemical ion exchange with a hydrous manganese(IV) oxide ion exchanger using an elution chromatography. The capacity of manganese(IV) oxide ion exchanger was 0.5 meq/g. The heavier lithium isotope was enriched in the solution phase, while the lighter isotope was enriched in the ion exchanger phase. The separation factor was determined according to the method of Glueckauf from the elution curve and isotopic assays. The separation factor of {sup 6}Li{sup +} -{sup 7}Li{sup +} isotope pair fractionation was 1.018.

International Nuclear Information System (INIS)

In this paper, an attempt is made to outline the priority areas for research in human nutrition in India that could be tackled by appropriate application of stable isotope technology. 10 refs.

Science.gov (United States)

The gamma spectra and lifetimes of the Ta and W isotopes havimg mass numbers 173, 175, 177, and 179 are determined. (T.F.H.)

Energy Technology Data Exchange (ETDEWEB)

Rats were exposed to lead (Pb) before or after weaning. For preweaning exposures, nursing dams received 0.2% Pb acetate(1090 ppm Pb) in drinking water. Offspring treated after weaning consumed the same concentration. Tapwater served as the control fluid. Pre-post treatments were distributed among four experimental groups of 10 rats each: tap water-tap water, Pb-tap water, tap water-Pb, Pb-Pb. Operant behavior training began on Postnatal Day 58. Animals performed on a multiple reinforcement schedule of food presentation consisting of fixed-interval, fixed-ratio, and time out components.Statistical analyses of experimental sessions 4 to 11 (Postnatal Days 72 to 79) revealed that postweaning exposure significantly lengthened the median interval (interresponse time) between consecutive responses on both the interval and ratio schedules. Preweaning exposure alone ...

International Nuclear Information System (INIS)

In this study, the excitation functions for the reactions "2"0"3Tl(p, n)"2"0"3Pb, "2"0"5Tl(p, 3n)"2"0"3Pb, "2"0"3Tl(p, 2n)"2"0"2Pb, "2"0"5Tl(p, 4n)"2"0"2Pb, "2"0"3Tl(p, 3n)"2"0"1Pb, "2"0"5Tl(p, 5n)"2"0"1Pb, "2"0"3Tl(p, 4n)"2"0"0Pb and "2"0"5Tl(p, 6n)"2"0"0Pb have been calculated using pre-equilibrium and equilibrium reactions mechanisms. Calculated results based on hybrid model, geometry-dependent hybrid model and cascade-exciton model have been compared with the experimental data. (author)

International Nuclear Information System (INIS)

... bismuth 203 chemical reactions cyclotrons decay helium 3 beams impurities

Energy Technology Data Exchange (ETDEWEB)

Possibilities of applying the Pb/sup 203/ isotonic solution without a carrier as a label of blood erythrocytes, are found. There is a number of advantages in the Pb/sup 203/ isotonic solution without a carrier, such as a high label efficiency (above 95%), a short half-life (52 hours), and a low radiation dose. These factors prove to be favourable as compared with Cr/sup 51/ widely used for these purposes. Besides, of all preparations used up to now to treat erythrocytes and to scan the spleen, it is only in the case of Pb/sup 203/ isotonic solution without a carrier that no weight amounts of chemical substances do not enter the organism.

International Nuclear Information System (INIS)

... data deuteron beams energy dependence errors gamma radiation lead 203

International Nuclear Information System (INIS)

A procedure for the determination of lead in soil samples by "2"0"3Pb radioisotope dilution substoichiometric method is described. Japan NIES No.2 river clay standard sample and 83-40 Tibet soil standard sample were determined. The obtained values were in good agreement with reference values. The standard deviation of the method was less then 5%. Detection limit was about 0.1 #mu#g Pb.

International Nuclear Information System (INIS)

... VDPEAZ (Bonn 2010 issue) NUCLEAR PHYSICS AND RADIATION PHYSICS

International Nuclear Information System (INIS)

... blood serum patients radioimmunoassay sampling tracer techniques isotope

Energy Technology Data Exchange (ETDEWEB)

The electrical resistivity at low temperatures (T = 10 to 90 K) of the lithium isotopes /sup 6/Li and /sup 7/Li and of an isotopic mixture /sup 7 +6/Li has been studied. The specimens contained a small amount of chemical impurities. An appreciable difference was observed in the temperature dependence of the resistivity produced both by deformation of the phonon spectrum, related to the change in isotopic composition, and by the presence of chemical impurities making the nonequilibrium part of the electron distribution function more isotropic.

Energy Technology Data Exchange (ETDEWEB)

The membrane transport of the two stable lithium isotopes, {sup 6}Li and {sup 7}Li, by erythrocytes has been studied using a dual channel atomic absorption spectroscopic technique. {sup 6}Li appears to be taken up preferentially to {sup 7}Li, in the ratio of 10 to 40%, depending on the concentration of total lithium and on the lithium isotopic ratio in the external medium.

International Nuclear Information System (INIS)

Short communication.

International Science & Technology Center (ISTC)

Development of Technologies for Boron-10 Isotope Modified Boron-containing Materials Production and their Properties Investigation.

Energy Technology Data Exchange (ETDEWEB)

[sup 203]Pb-chloride is a promising imaging agent for tumour scanning because of the large retention value for tumour tissue and the small value for normal organs, but the large value for the kidneys and bone is a shortcoming. The retention value of [sup 203]Pb in tumour tissue is larger than that of [sup 201]Tl and smaller than that of [sup 67]Ga. The tumour/inflammatory lesion retention ratio for [sup 203]Pb is very large in comparison with those for [sup 67]Ga and [sup 201]Tl. [sup 203]Pb accumulates to a large extent in viable tumour tissue, and less in necrotic tumour tissue and in inflammatory lesion. (author).

Energy Technology Data Exchange (ETDEWEB)

Identifying stable isotope variation and mineralogical changes in fractured rock may help establish the history of climatic and geomorphological processes that might affect the isolation properties of a waste repository site. This study examines the use of the stable isotope ratios of oxygen ({sup 18}O/{sup 16}O) and carbon ({sup 13}C/{sup 12}C) in authigenic minerals as hydrogeochemical tools tracing low-temperature rock-water interaction in variably-saturated fractured stuff. Isotopic compositions of fracture-filling and rock matrix minerals in the Apache Leap tuff, near Superior, Arizona were concordant with geothermal temperatures and in equilibrium with water isotopically similar to present-day meteoric water and groundwater. Oxygen and carbon isotope ratios of fracture-filling, in unsaturated fractured tuff, displayed an isotopic gradient believed to ...

Energy Technology Data Exchange (ETDEWEB)

The transfer of /sup 203/Pb and/or /sup 47/Ca across the intestinal epithelium of the chick was investigated, with emphasis given to the functional role of cholecalciferol (vitamin D-3). /sup 203/Pb, after introduction in the intestinal lumen, is rapidly accumulated by the intestinal tissue, and only a fraction of /sup 203/ Pb is translocated parenterally (absorbed). Cholecalciferol did not significantly affect the accumulation of /sup 203/Pb by intestinal tissue but did accelerate /sup 203/Pb movement across the basal-lateral membrane. In contrast, cholecalciferol both decreased /sup 47/Ca tissue levels and increased /sup 47/Ca absorption. In rachitic chicks, the rate of absorption of /sup 203/Pb was greater in the distal than in the proximal segments of the intestine; after cholecalciferol repletion, the degree of absorption in all segments was similar, ...

Energy Technology Data Exchange (ETDEWEB)

DOE/NNSA and IRSN collaborated on a study of gamma-ray instruments and analysis methods used to perform isotopic measurements of special nuclear materials. The two agencies agreed to collaborate on the project in response to inconsistencies that were found in the various versions of software and hardware used to determine the isotopic abundances of uranium and plutonium. IRSN used software developed internally to test the MGA and FRAM isotopic analysis codes for criteria used to stop data acquisition. The stop-criterion test revealed several unusual behaviors in both the MGA and FRAM software codes.

Energy Technology Data Exchange (ETDEWEB)

This study focuses the granitoids of center-southern portion of Guyana Shield, southeastern Roraima, Brazil. The region is characterized by two tectonic-stratigraphic domains, named as Central Guyana (GCD) and Uatuma-Anaua (UAD) and located probably in the limits of geochronological provinces (e.g. Ventuari-Tapajos or Tapajos-Parima, Central Amazonian and Maroni-Itacaiunas or Transamazon). The aim this doctoral thesis is to provide new petrological and lithostratigraphic constraints on the granitoid rocks and contribute to a better understanding of the origin and geo dynamic evolution of Guyana Shield. The GCD is only locally studied near to the UAD boundary, and new geological data and two single zircon Pb-evaporation ages in mylonitic biotite granodiorite (1.89 Ga) and foliated hastingsite-biotite granite (1.72 Ga) are presented. These ages of the protholiths contrast with the lithostratigraphic picture in the other areas of Cd (1.96-1.93 Ga). Regional mapping, ...

CERN Document Server

A Smarandache quasigroup(loop) is shown to be universal if all its f,g-principal isotopes are Smarandache f,g-principal isotopes. Also, weak Smarandache loops of Bol-Moufang type such as Smarandache: left(right) Bol, Moufang and extra loops are shown to be universal if all their f,g-principal isotopes are Smarandache f,g-principal isotopes. Conversely, it is shown that if these weak Smarandache loops of Bol-Moufang type are universal, then some autotopisms are true in the weak Smarandache sub-loops of the weak Smarandache loops of Bol-Moufang type relative to some Smarandache elements. Futhermore, a Smarandache left(right) inverse property loop in which all its f,g-principal isotopes are Smarandache f,g-principal isotopes is shown to be universal if and only if it is a Smarandache left(right) Bol loop in which all its f,g-principal isotopes ...

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We have measured production cross-sections of the new neutron-rich isotopes {sup 58}Ti, {sup 61}V, {sup 63}Cr, {sup 66}Mn, {sup 69}Fe, {sup 71}Co and neighbouring isotopes that have been identified as projectile fragments from reactions between a 500 MeV/u {sup 86}Kr beam and a beryllium target. The isotope identification was performed with the zero-degree magnetic spectrometer FRS at GSI, using in addition time-of-flight and energy-loss measurements. The experimental production cross-sections for the new nuclides and neighbouring isotopes are compared with an empirical parametrization. The resulting prospects for reaching even more neutronrich isotopes, such as the doubly-magic nuclide {sup 78}Ni, are discussed. (orig.).

International Nuclear Information System (INIS)

We have measured the isotope shifts of some dipole transitions between excited states of the even strontium isotopes 88 and 86 by applying the technique of Doppler-free intermodulated optogalvanic spectrocopy to a heat-pipe discharge. We were also able to investigate the isotope shift of the Sr II resonance line at 4216.6 A optogalvanically in the mentioned pair of isotopes. Because the 5 snf"1F_3 series appear to have zero level isotope shifts for n>=6, we can give residual level isotope shifts (RLIS) of several odd-parity states of sup(88,86) Sr I. The RLIS of the 5 snp "1P_1 series show pronounced configuration mixing around n=7. (orig.).

International Nuclear Information System (INIS)

A lysimeter approach (under natural climatologic conditions) was used to evaluate the effect of four metal immobilizing soil treatments [compost (C), compost + cyclonic ashes (C + CA), compost + cyclonic ashes + steel shots (C + CA + SS)) and cyclonic ashes + steel shots (CA + SS)] on metal leaching through an industrially contaminated soil. All treatments decreased Zn and Cd leaching. Strongest reductions occurred after CA + SS and C + CA + SS treatments (Zn: -99.0% and -99.2% respectively; Cd: -97.2% and -98.3% respectively). Copper and Pb leaching increased after C (17 and >30 times for Cu and Pb respectively) and C + CA treatment (4.4 and >3.7 times for Cu and Pb respectively). C + CA + SS or CA + SS addition did not increase Cu leaching; the effect on Pb leaching was not completely clear. Our results demonstrate that attention should be paid to Cu and Pb leaching when ...

International Nuclear Information System (INIS)

The cross sections of "2"0"4Pb(n,2n)"2"0"3Pb and "2"0"6Pb(n, #alpha#)"2"0"3Hg reactions have been measured by using the activation method in the neutron energy range of 13.50-14.81 MeV. Neutron fluence dose was calibrated with the cross sections of "2"7Al(n, #alpha#)"2"4Na reaction and neutron energies were determined by using the cross section ratios of "9"0Zr(n,2n)"8"9"m"+"gZr to "9"3Nb(n,2n)"9"2"mNb reactions. The results obtained are compared with the published data.

Energy Technology Data Exchange (ETDEWEB)

The Baird and McGuire site is a former chemical manufacturing facility in northwest Holbrook, Massachusetts, approximately 14 miles south of Boston. From 1912 to 1983 the company operated a chemical manufacturing and batching facility on the property. Manufactured products included herbicides, pesticides, disinfectants, soaps, floor waxes and solvents. Waste disposal methods at the site included direct discharge into the soil, nearby brook and wetlands, and a former gravel pit (now covered) in the eastern portion of the site. EPA conducted a removal action at the site in 1983 after a waste lagoon overflowed spreading contaminants into the Cochato River. The company ceased operating shortly thereafter. A second removal action was conducted in 1985, following the discovery of dioxin in site soils. EPA also conducted an Initial Remedial Measure at the site from 1985 through 1987 which involved constructing a new water main to direct water away from the site, removing ...

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The carbon isotope profiles of shallow-marine carbonates from the Barremian-Aptian Kharaib and Shuaiba formations of the Arabian Gulf region range between 0.5 and 7{per_thousand} {delta}{sup 13}C PDB (Peedee belemnite). Systematic variations can be correlated with isotope profiles reported from Tethyan pelagic limestone sequences. The detailed correspondence between the isotopic signature of the relatively well-dated pelagic limestones and the poorly dated shallow-water limestones from the Arabian Gulf region suggests that global marine carbon isotope changes apparently affected deep-sea and shallow-water carbonate sediments similarly and at a similar time resolution. Although oxygen isotopes have been reset during diagenesis, carbon isotopes appear to have maintained their primary marine signature through time. No evidence has been found to connect carbon ...

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The chemical separation of carrier-free /sup 203/Pb following deuterium bombardment of a /sup 203/Tl target is described. Coprecipitation from strontium sulphate was used to separate the /sup 203/Pb from a solution of the thallium target in sulphuric acid. The SrSO/sub 4/ precipitate was filtered, washed and dissolved in hydrochloric acid, from which /sup 203/Pb was again separated by precipitation on sodium chloride from a strongly acid solution. Advantages of the system are discussed and optimum conditions given.

International Nuclear Information System (INIS)

Instrumental neutron activation analysis is used for simultaneously determination of macrocomponents in ferroelectric materials LLZT. Pb, Zr, Ti have been determined by "2"0"3Pb, "8"9Zr and "4"8Sc nuclides created by fast neutron (14.5 MeV) activation. Application of paraffine as neutron moderator and reflector allows to simultaneously determine lanthanum by "1"4"0La nuclide. It has been shown that zirconium, titanium and lanthanum can be determined with the accuracy of #+-#0.1 mas. % and lead - #+-#0.7 mas. %.

International Nuclear Information System (INIS)

... compton spectrometers cross sections energy resolution energy-level transitions

Energy Technology Data Exchange (ETDEWEB)

Strong-interaction effects have been observed in the x-ray spectra of atoms formed with [Sigma][sup [minus

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The USAF Surgeon General approved pyridostigmine bromide (PB) pretreatment for flying personnel as of 21 March 1986. However, specific side effects resulting from taking PB during high sustained + G/sub z/ stress, altitude stress, and periods of potential spatial disorientation had not yet been fully investigated. The USAF school of Aerospace Medicine (UASFSAM), Crew Technology Division, was therefore tasked with this clinical research effort. For effective investigation of these potential problem areas, rapid and accurate methods have had to be established for determining the blood plasma PB levels and the resultant inhibition of acetylcholinesterase activity. The basic purpose of this report is to describe in detail the analytical techniques used at USAFSAM to support the clinical research programs involving the physiological and performance aspects of USAF aircrews taking PB.

Science.gov (United States)

... Abstract : Single crystals of Pb(x)Sn(1-x)Te alloy have been grown with o = or thin film evaporator. ...

UK PubMed Central (United Kingdom)

The carbon-isotope ratio recently obtained for the carbon found in the Murchison meteorite, which has been shown (by the racemic nature of twelve component amino acids) to be free of terrestrial contamination,...Full Text Available

International Nuclear Information System (INIS)

The angular #gamma##gamma#-correlations for nuclei of Sr even-even isotopes with a=8 82, 84, 86, 88 were measured. Multipole structurs of #gamma#-transtion series and th coefficients multipole mixing were determined.

Science.gov (United States)

... M. Taylor, T. Kurt Kyser. (2009) Feather isotope analysis discriminates age-classes of Western, Least, and Semipalmated sandpipers when plumage ... ...

International Nuclear Information System (INIS)

Based on a generalized theory of perturbations and on non-linear programming an approach to the quantitative determination of necessary accuracies for nuclear data is described. It is used to calculate transactinide isotope build-up in reactors.

Science.gov (United States)

... M. Taylor, T. Kurt Kyser. (2009) Feather isotope analysis discriminates age-classes of Western, Least, and Semipalmated sandpipers when plumage ... ...

UK PubMed Central (United Kingdom)

¹³C metabolic flux analysis (MFA) is the most comprehensive means of characterizing cellular metabolic states. Uniquely labeled isotopic tracers enable more focused analyses to probe...Full Text Available

International Nuclear Information System (INIS)

... fermions interacting boson model molybdenum 101 neutron-rich isotopes

International Nuclear Information System (INIS)

Separation of lithium isotope by NTOE compound was carried out with 0.01M HCl solution. The ion exchange capacity of NTOE was 0.8 meq/g. The separation factor, #alpha#=("7Li/"6Li)_s_o_l_i_d/("7Li/"6Li)_l_i_q_u_i_d was 1.0242 by the elution chromatography. The lighter isotope, "6Li was concentrated in the liquid phase, while the heavior isotope, "7Li was enriched in the solid phase. (author).

International Nuclear Information System (INIS)

... nuclear electric moments nuclear magnetic moments nuclear radii quadrupole

International Nuclear Information System (INIS)

... carrier-free isotopes hafnium compounds irradiation protons solvent extraction

Energy Technology Data Exchange (ETDEWEB)

The effects of temperature and the use of macroreticular resins were studied in lithium isotope separation by an ion-exchange method. The isotope separation factors obtained decreased by increasing the temperature, and the factors for macroreticular resins were identical with those for the usual gel-type resins. However, the performance of isotope separation per unit band length in displacement chromatography was found to be improved by increasing the temperature and using macroreticular resins, because accelerating the interphase mass transfer caused the reduction of HETP (Height Equivalent to a Theoretical Plate).

International Nuclear Information System (INIS)

... intermediate mass nuclei isotopes leptonic decay nuclei odd-even nuclei

International Nuclear Information System (INIS)

Page 1. RADIOCHEMISTRY, STABLE ISOTOPES, NUCLEAR ANALYTICAL

International Nuclear Information System (INIS)

Short note. 2 refs.; 1 tab.

Energy Technology Data Exchange (ETDEWEB)

The nuclear shapes of transitional Mo isotopes are calculated by means of a model based on the cranking approximation and the Strutinksy method. The recent experimental results of the high-spin spectroscopy and lifetime measurement of [sup 87]Mo are studied in detail and explained by the evolution of the [gamma]-deformation with the quasiparticle configurations. The shape calculations with the modified-harmonic-oscillator potential give a critical neutron number N [>=] 47 for the spherical shape of the Mo isotopes. (orig.)

International Nuclear Information System (INIS)

The method of inversion of the eigenvalue problem previously developped for nuclei with axial symmetry is extended to asymmetric equilibrium shapes. This new approach to the asymmetric rotator model is applied to the odd-mass Iridium isotopes. A satisfactory and coherent description of the observed energy spectra is obtained, especially for the lighter isotopes. (orig.).

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This report was prepared in response to a request from the Nuclear Energy Research Advisory Committee (NERAC) subcommittee on ''Long-Term Isotope Research and Production Plans.'' The NERAC subcommittee has asked for a reply to a number of questions regarding (1) ''How well does the Department of Energy (DOE) infrastructure sme the need for commercial and medical isotopes?'' and (2) ''What should be the long-term role of the federal government in providing commercial and medical isotopes?' Our report addresses the questions raised by the NERAC subcommittee, and especially the 10 issues that were raised under the first of the above questions (see Appendix). These issues are related to the isotope products offered by the DOE Isotope Production Sites, the capabilities and condition of the ...

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In this report, the quantitative relation between the height equivalent to a theoretical plate (HETP) and the size of ion exchange resin is studied by enriching lithium isotopes with high pressure ion exchange displacement chromatography. The dependence of HETP on the size of the resin can be expressed as H = C x (anti r)sup( ) in which = 2.4 and it is found that Snyder's equation is suitable for such a system of isotope separation as may be explained by the simple displacement mechanism.

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Transverse form factors have been extracted for the low-lying neutron hole (particle) states of /sup 207/Pb from inelastic-electron-scattering data. A systematic, multipolarity-and momentum-transfer-independent quenching of approx.55% in the transverse amplitude is observed when compared with single particle predictions for both electric and magnetic transitions. The magnitude of the observed effect is not readily explained by our present theoretical understanding of this nucleus.

International Nuclear Information System (INIS)

Radiometric X-ray fluorescence analysis was used for the determination of Mn, Fe, Cu, Zn and Pb in wastewater and sludges from three wastewater treatment plants in Bratislava (SR). Metals were determined in wastewaters after preconcentration by 8-hydroxyquinoline and in sludges by drying and pressing to pellets. "2"3"8Pu and "1"0"9Cd was used for excitation of fluorescence radiation. (author).

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The use of Chelex resin for the synthesis of radioactive lead complexes has been explored. The process involved immobilization of {sup 203}Pb on the resin and subsequent elution of complexed lead by chelating agents. {sup 203}Pb complexes derived from meso- and racemic dimercaptosuccinic acid (meso-DMSA, rac-DMSA) were prepared and assessed for stability in vitro.

International Nuclear Information System (INIS)

Airborne lead particulates collected on a membrane filter were determined by the nondestructive X-ray fluorescence method. The gamma/X radionuclide source "2"4"1Am/Ag and a scintillation detector with a NaI/Tl crystal were used for the excitation and detection, respectively, of L X-rays of Pb. One can say, with reference to the obtained results, that the sensitivity and accuracy of the measurement is more than adequate for monitoring the Pb level in air. (author).

Energy Technology Data Exchange (ETDEWEB)

The PbII binding characteristics of the previously reported PbII binding proteins of rat kidney cytosol were investigated further. Saturation and Scatchard analysis of /sup 203/Pb binding in whole cytosol and in 40% saturated ammonium sulfate precipitated fractions disclosed a class of relatively high-affinity sites with an apparent Kd of approximately 50 nM and binding capacities of approximately 41 and 9 pmol/mg of protein, respectively. Two /sup 203/Pb binding proteins with approximate molecular masses of 63K and 11.5K daltons and a high molecular weight component (greater than 200K) were isolated by Sepharose-6B column chromatography. The time course of association of /sup 203/Pb with cytosol and the 63K protein showed maximum binding at 18 hr which was stable up to 25 hr at 4 degrees C. The approximate half-time dissociation rate (T 1/2) of specifically bound /sup ...

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The gastrointestinal absorption of lead was markedly increased in human subjects who had fasted before ingesting lead. Food in the gut was found to reduce lead absorption, and the effect of dietary constituents on /sup 203/Pb absorption was investigated. The greatest reduction in absorption was caused by minerals. This dependence of lead absorption on dietary constituents complicates the establishment of safe levels of lead in food and water.

International Nuclear Information System (INIS)

Effects of PbO on the repassivation kinetics of alloy 690TT were examined using the rapid scratching electrode technique under a potentiostatic condition to elucidate the influence of PbO on SCC resistance of the alloy. The repassivation kinetics of the alloy was analyzed in terms of the current density flowing from the scratch, i(t), as a function of the charge density that has flowed from the scratch, q(t). Repassivation on the scratched surface of the alloy occurred in two kinetically different processes; passive film initially nucleated and grew according to the place exchange model in which log i(t) is linearly proportional to q(t) with a slope of 1/K, and then grew according to the high field ion conduction model in which log i(t) is linearly proportional to 1/q(t) with a slope of cBV. 1/K and cBV are parameters representing the SCC susceptibility as well as repassivation rate of the alloy at an initial and an intermediated stages of ...

International Nuclear Information System (INIS)

Radionuclide X-ray fluorescence method with Si/Li semiconductor detector and "2"3"8Pu exciting source was used for the determination of Cu, Ni, Zn and Pb in plant samples (Taraxacum officinale) from various localities near the highway D-61 Bratislava-Trnava (SR). (author) 2 refs.; 1 fig.; 1 tab.

International Nuclear Information System (INIS)

A study was made on extraction of a series of lithium and calcium salts by monopodands L with common formula R-C_6H_4-O-(CH_2CH_2O)_n-C_6H_4-R, where R - CH_2P(O)Ph_2, n 1-3. Extraction-chromatographic separation of lithium and calcium isotopes in systems of metal aquacomplex-solvatocomplex with L in organic phase was conducted. It was established that separation coefficients of "6Li/"7Li isotopes ranged between 1.003 #+-#0.001 and 1.017 #+-#0.002 at the maximal separation degree equal to 1.60. Separation of "4"0Ca/"4"4Ca isotopes was not fixed. 12 refs., 4 figs., 1 tab.

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Standard Leadframes used in surface mount technology are finished with a layer of eutectic SnPb for passivation and for enhancing solder wetting during reflow. When eutectic SnPb is replaced by Pb-free solder, especially the eutectic SnCu, a large number of Sn whiskers are found on the Pb-free finish. Some of the whiskers are long enough to become shorts between the neighboring legs of the leadframe. How to suppress their growth and how to perform accelerated test of Sn whisker growth are crucial reliability issues in the electronic packaging industry. In this paper, we report the study of spontaneous Sn whisker growth at room temperature on eutectic SnCu and pure Sn finishes. Both compressive stress and surface oxide on Sn are necessary conditions for whisker growth. Structure and stress analyses by using the micro-diffraction in synchrotron radiation are reported. Cross-sectional electron microscopy, ...

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Traditionally wafer bumps are made from Pb containing solders. Over 20 years ago IBM recognized that {sup 210}Pb has a decay chain resulting in a 5.4 MeV alpha particle that induces soft errors. A variety of efforts to produce and characterize low alpha Pb ensued. Work at Honeywell over the past several years has shown that low alpha lead activity does not follow the decay signature predicted from {sup 210}Pb secular equilibrium. Data are presented indicating that smelting has a minimal effect on {sup 210}Pb/{sup 210}Po secular equilibrium and that other trace radionuclides are the alpha source. The implications of these data to possible alpha emitter sources in lead free solders are discussed, along with a method developed by Honeywell to remove alpha emitters from lead free solder components.

International Nuclear Information System (INIS)

Lithium isotopes are used as the raw material of tritium which is the fuel for fusion power generation and the material for fusion reactors, accordingly those are indispensable for future nuclear fusion power generation. As for boron isotopes, the neutron absorption corss section is very large, therefore, they are used for shielding neutrons and controlling fast neutron reactors. In order to further develop the utilization of nuclear power, it is important to develop the technology for separating and refining light element isotopes in large amount. In fiscal year 1995, the relation of the ion sieve characteristics of inorganic ion exchanger and the behavior of lithium isotope separation was examined. The behavior of forming boron complex of polyol amine was examined by B-11 NMR. These experiments and the results are reported. It was shown to be feasible that lithium is adsorbed from seawater, and ...

International Nuclear Information System (INIS)

Study of the ground-state properties of Kr, Sr and Zr isotopes has been performed in the framework of the relativistic mean-field (RMF) theory using the recently proposed relativistic parameter set NL-SH. It is shown that the RMF theory provides an unified and excellent description of the binding energies, isotope shifts and deformation properties of nuclei over a large range of isospin in the Z=40 region. It is observed that the RMF theory with the force NL-SH is able to describe the anomalous kinks in isotope shifts in Kr and Sr nuclei, the problem which has hitherto remained unresolved. This is in contrast with the density-dependent Skyrme-Hartree-Fock approach which does not reproduce the behaviour of the isotope shifts about shell closure. On the Zr chain we predict that the isotope shifts exhibit a trend similar to that of the Kr and Sr nuclei. The RMF theory also predicts ...

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Biosorption is presented as an alternative choice to traditional physicochemical means for removing toxic metals from groundwater and wastewaters. Removal of lead (Pb) from solutions was studied using Escherichia coli (parental) and Vitreoscilla hemoglobin (VHb)-expressing E. coli (transformed) cells. Pb biosorption was increased in bacterial hemoglobin-expressing E. coli cells grown in Luria broth B containing different concentrations of Pb{sup 2+}. The maximum Pb{sup 2+} biosorption of transformed and parental cells was determined to be 612 and 370 {mu}g Pb/g biomass, respectively. The inhibitory effect of Pb{sup 2+} on the parental strain was determined at 10 ppm. However, in transformed cells, Pb{sup 2+} was lethal at 100 ppm. The optimum aeration required for the transformed cells was lower than that for the parental strain on a growth ...

International Nuclear Information System (INIS)

A standard of "2"1"0Pb in solution was produced at the National Physical Laboratory by a novel technique combining Cerenkov counting with the established liquid scintillation efficiency tracing technique known as the CIEMAT/NIST method. Coincidence counting was applied in order to validate the measurements and the activity concentrations of the solution determined with each technique are shown to be in agreement. Radiochemical separation of the "2"1"0Pb from its daughters was also necessary and the scheme for the separation is described. After performing this two-stage standardisation, the uncertainty was successfully lowered to 0.66% (k=1). This uncertainty is approximately a factor of four lower than previously achieved at NPL by the classical method of standardisation of radionuclides, i.e. coincidence counting.

International Nuclear Information System (INIS)

The electronic structure and optical properties in tetragonal ceramics PbTiO_3, are studied by using full-potential linearized augmented plane wave method in density functional theory with the generalized gradient approximation by WIEN2K package. The theoretical calculated optical properties and energy loss spectrum yield a static refractive index of 2.59 and a plasmon energy of 22.7eV for the tetragonal phase. The effective electron number at low energy saturates near 22-23eV with the value of 50 for the effective electron number. The results show a indirect band gap of 2.2eV at the I' point in the Brillouin zone. The :calculated band structure and density of states of PbTiO_3 agree with previous experimental and theoretical results.

International Nuclear Information System (INIS)

One measured fission and fusion cross sections of "4","6He+"2"0"9Bi and "7Li+"2"0"8Pb reactions within the range from the Coulomb barrier up to 200 MeV. The measured functions of fission and fusion for the mentioned reactions are shown to have close values within the excitation energy wide range. One analyzed the excitation functions of fusion and fission for "4He+"2"0"9Bi, "6He+"2"0"9Bi and "7Li+"2"0"8Pb reactions resulting in formation of "2"1"3","2"1"5At compound systems

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For analysis of a small quantity of americium, it is necessary to separate from curium which has similar chemical property. As a chemical separation method for americium and curium, the oxidation of americium with pentavalent bismuth and subsequent co-precipitation of trivalent curium with BIP O{sub 4} were applied to analyze americium in irradiated MOX fuels which contained about 30wt% plutonium and 0.9wt% {sup 241}Am before irradiation and were irradiated up to 26.2GWd/t in the experimental fast reactor Joyo. The purpose of this study is to measure isotopic ratio of americium and to evaluate the change of isotopic ratio with irradiation. Following results are obtained in this study. (1) The isotopic ratio of americium ({sup 241}Am, {sup 242m}Am and {sup 243}Am) can be analyzed in the MOX fuels by isolating americium. The isotopic ratio of {sup 242m}Am and {sup 243}Am increases up to 0.62at% and ...

International Nuclear Information System (INIS)

Liquid-liquid extractive separation of lithium isotopes was carried out in order to investigate the fluctuation of separation factors (a) as a function of salt concentrations in an aqueous phase. Two equations for separation factor (a_o_b_s) as a function of the concentration were introduced; one for the diluted region, and another for the concentrated region. In the former solution where hydrated lithium ions are predominant, 1n a_o_b_s = Ac + B, and in the latter where ion-pairs with anions are predominant, 1n a_o_b_s = Dc + E(c - F)"1"/"3 + G. Some guidelines are derived from the salt-specific constants A, B, D, E, F and G. The heavier isotopes are inclined to be in the more hydrated state in the diluted solution, while the lighter isotopes tend to be in a less hydrated state. In the concentrated solution, heavier isotopes are more likely to be in ion-pair form. Ionic association occurs from the ...

Energy Technology Data Exchange (ETDEWEB)

We propose a novel method for ultrasensitive isotope analysis that combines magnetic mass selection, resonant charge-exchange neutralization, and resonant laser ionizaion. Our method attains high isotopic abundance selectivity by means of continuous multistage separation of ions stored in a small ring. For the environmentally interesting case of /sup 90/Sr versus /sup 88/Sr we estimate that sensitivity better than 10/sup -15/ for a throughput of 10/sup 13/ atoms/sec and an efficiency (after the ion source) greater than 10% are readily achievable.

International Nuclear Information System (INIS)

The neutron-rich Fe isotopes from A=61 to 66 were studied through multinucleon transfer reactions by bombarding a "2"3"8U target with a 400 MeV "6"4Ni beam. Unambiguous identification of prompt #gamma# rays belonging to each nucleus was achieved using coincidence relationships with the ions detected in a high-acceptance magnetic spectrometer. The new data extend our knowledge of the level structure of Fe isotopes, which is discussed in terms of the systematics of the region and compared with large-scale shell-model calculations.

International Nuclear Information System (INIS)

Special beam extraction channel is used at INR linac for isotope production. It starts from 160 MeV measuring and matching area of accelerator. This choice of beam extraction enables to direct to the target of isotope complex a proton beam of wide energy range up to 160 MeV. It is important for production of different types of nuclides. The measuring results of proton beam behavior in this region are presented. Required beam forming in 160 MeV measuring and matching area of accelerator and in beam extraction channel is discussed.

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The performance of a high temperature ion source coupled to a helium gas-jet transport system for an efficient mass separation of neutron-rich alkaline earth and lanthanide isotopes is reported and the results of overall efficiency measurements using different cluster materials in the gas-jet are given. A fast, microprocessor controlled tape transport system for ..gamma..-spectroscopic studies on short-lived isotopes is described. Some results on the decay of 3.8sub(-s) /sup 152/Pr are presented.

International Nuclear Information System (INIS)

COMPLIS is an experimental facility designed to carry out spectroscopic studies on radioisotopes produced by disintegration of elements available at CERN's Booster-ISOLDE on-line isotope separator. During recent series of experimental runs, hyperfine structure measurements have yielded information on nuclear moments and deformations of platinum and iridium isotopes. For the first time, population by #alpha#-decay from Hg was exploited to investigate "1"7"8"-"1"8"1Pt--the most neutron-deficient Pt isotopes yet studied. Successful measurements have recently been carried out on "1"8"2"-"1"8"9Ir.

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A laser-induced plasma of alkali atoms was studied with a view to efficient recovery of isotope ions, with small charge exchange losses. The electron temperature was measured by the double-probe method for several kinds of excitation schemes, which gave the relationship between temperature and the energy given to ions by laser photons. A charge exchange process between lithium isotopes was also studied in an electromagnetic field. It was shown that optimum electrostatic and magnetic field strength exist which maximise the 'separative power'.

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The carbon cycle is an important part of major biogeochemical cycles. Many techniques may be used to characterize carbon amounts and sources in the environment. Here we first review the most popular techniques for the determination of organic and inorganic carbon concentrations. Decarbonatation techniques are also reviewed in details since it is often an important part of organic carbon analysis. The second part of this paper addresses the use of carbon stable isotopes to characterize organic carbon sources and processes in the environment. An overview of general stable isotopes background and terminology is given as well as the most popular analytical techniques.

International Nuclear Information System (INIS)

In this paper, steady-state isotopic transient kinetic analysis (SSITKA) is used to study two model reactions, CO oxidation and CO-NO reactions, on a typical formulation of a three-way auto-catalyst. Under steady-state conditions, abrupt switches in the isotopic composition of CO ("1"2C"1"6O/"1"3C"1"8O) were carried out to produce isotopic transients in both labeled reactants and products. Along with the determination of the average surface lifetimes and concentrations of reaction intermediates, an analysis of the transient responses along the carbon reaction pathway indicated that the distribution of active sites for the formation of CO_2 was bimodal for both reactions. Furthermore, relatively few surface sites contributed to the overall reaction rate.

International Nuclear Information System (INIS)

A high-precision Li isotope analysis was developed for determining the Li"+ ion emitted from lithium phosphate as an ion source material by a Re double-filament ionization method in the thermal ionization mass spectrometry. In this method, Li isotopic fractionation is distinctly less sensitive to the filament temperature than those in the previous methods, and stable and high ion beam intensity of more than 8 x 10"-"1"1 A for "7Li is obtained. These advantages in determining the "7Li/"6Li ratio result in the analytical reproducibility of 0.26 per mille (1#sigma#). Furthermore, the sample preparation is simple and the low temperature (850degC) required by this method ensures the analysis of the isotopic composition of small amounts of Li with less influence of Li contamination to the sample, compared with the previous methods. (author).

Energy Technology Data Exchange (ETDEWEB)

We have determined the nuclear charge radius of 11Li by high-precision laser spectroscopy. The experiment was performed at the TRIUMF-ISAC facility where the 7Li-11Li isotope shift was measured in the 2s to 3s electronic transition using Doppler-free two-photon spectroscopy with a relative accuracy better than 10 5. The accuracy reached in previous experiments on the other lithium isotopes was improved. Most of the isotope shifts measured in the experiment are due to difference in the mass of the nuclei but small contributions are produced by the change in proton distribution, QED and relativistic effects have to be taken into account as well. By comparing the experimental results with sophisticated atomic calculations of the mass dependent effect the nuclear charge radii of the lithium isotopes are found to decrease monotonically from 6Li to 9Li while the nuclear charge radius of 11Li is about 11% ...

International Nuclear Information System (INIS)

Neutron yield from the "6","7Li + d reaction has been investigated. The results obtained are compared with the published data with some theoretical models.

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There is considerable interest in the use of silicon devices as qubits for quantum computing. The existence of nuclear spin in a silicon isotope and the complex band structure of silicon are unfavourable for this application of silicon devices. (viewpoint)

Science.gov (United States)

The location of defective LMFBR fuel pins by the determination of gas tag isotopic ratios is discussed. The application of this method to the FFTF Reactor briefly described.

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A tunable diode laser is used to obtain infrared spectra of carbon dioxide in biological materials. The spectral resolution is sufficient to readily distinguish differing isotopic species. The technique may prove useful in clinical tests.

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A brief review of standard big bang nucleosynthesis theory and the related observations of the light element isotopes is presented. Implications of BBN on chemical evolution and constraints on particle properties will also be discussed.

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Recently, the precise isotope ratios of some refractory elements in meteorites have been reported using inductively coupled plasma mass spectrometry. The in situ decay of {sup 182}Hf (T{sub 1/2}=9 Myr), which was produced at the latest nucleosynthesis, is recognized in many meteorites as isotopic anomalies of its daughter isotope, {sup 182}W. The degrees of relative {sup 182}W isotopic deviation in extra-terrestrial and terrestrial silicate samples vary from +0.3% to {+-}0% related to the size of their parent bodies. One ready interpretation of its correlation is the difference in timing of metal-silicate separation in the parent bodies. Between the earth and meteorite parent bodies, the difference is calculated to be about four times of the half-life of {sup 182}Hf, equivalent to 36 Myr. (author)

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... Inst. of Modern Physics 7-5022-0983-2 180 p. beta decay ft value ground states

UK PubMed Central (United Kingdom)

The intracellular bioavailability of lead (Pb) at low dosage levels in major target organs such as the kidney and brain appears to be largely determined by complexation with a group of low molecular...Full Text Available

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This study deals with the adsorption and desorption of lead (c <= 10/sup -8/ - 10/sup -3/ M), labelled with /sup 212/Pb or /sup 210/Pb, on glass in relation to pH and composition of the solution, concentration of lead and time. The prevailing mechanism of the adsorption in the pH range from 3 to 8 is the ion exchange of Pb/sup 2 +/ and PbOH/sup +/ ions in electric double layer on the surface of glass. At the higher pH values lead (c <= 10/sup -8/ - 10/sup -6/ M) is adsorbed mainly by physical adsorption or chemisorption of its hydrolyzed forms. A rather high adsorption capacity of glass, exceeding 3.10/sup -9/ M/cm/sup 2/, has been found in neutral solutions for the cationic forms of lead. The adsorbed lead can be easily desorbed with the solution of 1 M nitric acid.

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Effects associated with the temperature dependence of the level density parameter, a(T), are investigated in connection with neutron evaporation processes. Different approximations, for this temperature dependence, are compared for the case of neutron emission from the compound nucleus /sup 209/Pb.

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Experimental results of nuclear reaction and radiative decay for A = 203 nuclides are evaluated. Adopted properties for all the nine isobars, Au, Hg, Tl, Pb, Bi, Po, At, Rn, Fr of mass 203 are presented. Nothing is yet known for [sup 203]Os. 96 refs.

International Nuclear Information System (INIS)

Nov 1983. p. 32-33. Germany Corcalciuc, V. Institutul Central de Fizica,

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The temperature effect on corrosion behaviors of PbCaSnCe alloy in 4.5 M H{sub 2}SO{sub 4} solution was investigated by using potentiodynamic curve, electrochemical impedance spectra (EIS), Mott-Schottky plot and photocurrent response methods. It was found that PbCaSnCe alloy was in passive state in sulfuric acid solution, a passive film can be formed on alloy surface. The compositions of passive films formed at 0.9 V for 2 h under different temperatures were detected by X-ray photoelectron spectroscopy (XPS). The results showed that the film resistance and the transfer resistance decreased with the increment of the solution temperature. Mott-Schottky analysis and the photocurrent response revealed that the passive film exhibited n-type semi-conductive character, the donor density of the passive film decreased with increasing the solution temperature. Photocurrent response revealed that the photocurrent increased with increasing temperature. ...

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... v. 36(2) NUCLEAR PHYSICS AND RADIATION PHYSICS beta-minus decay

UK PubMed Central (United Kingdom)

In-vitro experiments using 203Pb were performed to identify the lead binding components in human peripheral blood. The distribution of lead in plasma, in the red cell membrane, and within the red cell...Full Text Available

International Nuclear Information System (INIS)

Two experiments are currently underway to measure the single-particle weak mixing matrix element for the 1064 KeV transition in "2"0"7Pb. One experiment measures the circular polarization of the 1064 KeV gamma ray emitted from an unpolarized source, while the other experiment measures the forward-backward asymmetry of gamma rays emitted from a polarized source. Analysis of the first set of polarized source data yields an upper limit of 46 eV for the single-particle weak mixing matrix element. copyright 1995 American Institute of Physics.

International Nuclear Information System (INIS)

Experimental differential cross sections for 104 MeV #alpha#-particle scattering have been analysed using a method recently proposed for model-independent analyses. Reliable values of isoscalar (0"+ -3"1"-) octupole transition rates in _5_0Ti, _5_2Cr and _2_0_8Pb are presented and compared with electromagnetic rates. (author).

International Nuclear Information System (INIS)

The results of dielectric measurements in a wide frequency range have been used to find that solid solution samples on the basis of PbSc_1_/_2Sb_1_/_2O_3 have blurred phase transitions. The Curie-Weiss law is performed for different compositions in the temperature range 10-150 K above Curie point. The change of value and sign of the difference between Curie and Curie-Weiss temperatures is connected with the change of phase transition blurring degree.

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Worker exposures to arsenic (7440382) (As), cadmium (7440439) (Cd), copper (7440508) (Cu), lead (7439921) (Pb) and sulfur-dioxide (7446095) (SO2) were surveyed at ASARCO, Incorporated (SIC-3331) in Hayden, Arizona on April 23 and 24, 1980. The evaluation was requested by an authorized representative of the United Steel Workers, Local 886, on behalf of an unspecified number of workers. Personal and area air samples were collected in the pug mill department, and workers were tested for blood Pb and urinary As concentrations. All four personal samples for As exceeded the OSHA standard of 10 micrograms per cubic meter, one sample exceeded the Cu dust standard of 1 milligram per cubic meter (mg/cu m), and one sample exceeded the Pb standard of 50 micrograms per cubic meter. Exposures to Cd fume, Cd dust, and SO2 were below the respective OSHA standard of 0.2mg/cu m, 1.0mg/cu m, and 5 parts per million. One worker had a urinary ...

International Nuclear Information System (INIS)

In-vitro experiments using "2"0"3Pb were performed to identify the lead binding components in human peripheral blood. The distribution of lead in plasma, in the red cell membrane, and within the red cell was also investigated. Studies of the distribution of "2"0"3Pb in the whole blood showed that at a lead concentration of 2.45 #mu#mol/l (50 #mu#g/100 ml) about 94% of lead had been incorporated by the erythrocytes and 6% remained in the plasma. After extraction of lipid by a methanol/chloroform mixture, about 75% of the lead was found to be associated with the protein fraction. The lipid contained about 21% of the "2"0"3Pb, the remainder being in the aqueous plasma. SDS polyacrylamide gel electrophoresis of blood plasma showed that almost 90% of the "2"0"3Pb was present in the albumin fraction; the remainder was likely to be associated with high molecular weight globulins. Several binding sites were ...

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The Lower Cretaceous Falher Member (Spirit River Formation) in the Deep Basin of Alberta is composed of 5 units (A-E) comprising the reservoir of the giant Elmworth gas field. Using high resolution sequence stratigraphy, 333 well logs and 65 cores were integrated to understand the evolution of Falher C and D in the study area. Five major faces associations were defined in each unit. The basal surface of Falher D overlies nonmarine deposits (Falher E) and is defined by a marine flooding surface (transgressive surface of erosion) partially modified by a subsequent regressive surface of erosion. Southward, all the facies become more continental and the marine flooding surface passes into a lagoon-on-nonmarine contact. Falher D contains a series of shingled marine sandstone lenses separated by erosional surfaces interpreted as seaward-dipping ravinement surfaces indicating different phases of marine transgression-regression. The Falher C basal surface is a marine ...

Science.gov (United States)

The Cretaceous rudist-bearing carbonates of the Arabian Gulf region are proven exploration targets for hydrocarbons and form the reservoirs of a number of giant fields, including Bu Hasa, Fateh, Fahud, Idd El Shargi, Rumaila, Shaybah, and Shah. Rudist buildups occur in three principal formations: (1) Aptian Shuaiba, (2) Cenomanian Mishrif, and (3) Maastrichtian Simsima. A regional subaerial unconformity marks the upper boundary of each of these formations. Associated with the rudists that dominate the Shuaiba Formation are calcareous algal crusts, foraminifera, and echinoid plates, which accumulated in mudstone, packstone, and carbonate sands. The Mishrif Formation contains mollusk fragments, bioclasitc packstones to grainstones, miliolid and nonrudist bivalves in muddy limestones, and rudist (mainly radiolitids and caprinids) conglomeratic floatstones, with fragmented rudists mixed with wackestone lithoclasts. The Mishrif sediments accumulated as a progradational, low-energy leeward ...

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The individual contributions in these proceedings are indexed separately. Main topics covered include the measurement of biological nitrogen fixation, studies of soil organic matter, investigations of nutrient uptake and use by plants, studies of plant metabolism and new methodologies in the analysis of stable isotopes. Refs, figs and tabs.

International Nuclear Information System (INIS)

Most diffusion phenomena in solids can be understood (or sometimes misunderstood) on a purely classical model. For light interstitials (hydrogen isotopes, the positive muon, and potentially He) there may be anomalous temperature dependences, and isotope effects, and anomalous response to electric fields and temperature gradients. Some of these anomalies are quantal in origin, and will be discussed. (author).

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The thesis explains the development of a mass spectrometerical isotope dilution analysis (MS/DA) for determining trace amounts of Tc. The Tc-97 isotope has been prepared by in-core irradiation of Ru of natural isotopic composition, and used as the indicator isotope. For separation of Tc-97 from the Ru matrix, a method has been developed to quantitatively separate Tc-97 from a high Ru surplus. For determining the isotope ratio for the MS/DA, a mass spectrometrical measuring technique has been found which allows reproducible measurement of the Tc-99/Tc-97 isotope ratio. Positive and, for the first time, also negative thermoionisation has been used as a method of selective ionisation of Tc. The applicability of the MS/DA for Tc trace analysis has been verified using two Al foils doped with Tc-99 or Mo-98, respectively. These have been irradiated in a nuclear ...

International Nuclear Information System (INIS)

Projectilelike fragments following the 80 MeV "1"6O+"2"7Al reaction have been detected using a Bragg-curve spectroscopy ionization chamber (BCS-IC). The atomic number is deduced from the Bragg-peak amplitude. Nitrogen isotopes are clearly resolved using either range or energy loss data. This is the first application of the BCS method for complete ion identification in a heavy-ion-induced reaction.

Science.gov (United States)

A {sup 92}Mo beam with an energy of {ital E}/{ital A}=70 MeV has been used to produce new isotopes near the proton drip line. The Michigan State University National Superconducting Cyclotron Laboratory A1200 fragment separator was used to detect the new isotopes {sup 78}Y, {sup 82}Nb, {sup 85}Mo, {sup 86}Tc, and {sup 89,90}Ru.

Science.gov (United States)

Evaluation procedures used to produce sets of evaluated data for the 33 heavy isotopes that fall in the range Z = 90 to Z = 98 are described. At the beginning of the discussion for each individual isotope, a computer-generated listing is given which summarizes the main properties of the data sets that are contained in the evaluation. (RWR)

International Nuclear Information System (INIS)

We have performed precision measurements in a magneto-optical trap of the 7P1/2 hyperfine structure of the isotopes 209-210Fr. The ratio of these hyperfine constants to the previously measured 7S1/2 ground state values reveals a significant hyperfine anomaly. This anomaly results from the different radial dependence of the electron density in the two atomic levels. The measurements are sensitive to changes in the radial distribution of the neutron magnetism.

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Prompt neutron spectra for Am isotopes ({sup 241}Am, {sup 242m}Am, {sup 243}Am) were calculated on the basis of a modified version of the Madland-Nix model combined with multimodal fission model. The predicted spectra were found to be in fair agreement with recent data. (author)

International Nuclear Information System (INIS)

Americium 242m and americium 242 were prepared by reactor irradiation of americium 241 as its diphthalocyanine complex. The product atoms were extracted from the parent isotope at an enrichment factor of 10. A Dowex 50 chromatographic column raised the factor to 24.6.

International Nuclear Information System (INIS)

In a cold fusion method by electrolysis, a hydrogen occluding material mainly comprising vanadium is used as a material for a negative electrode, and lithium isotopes are incorporated in the material by more than 93%. That is, the ratio of lithium 7 ("7Li) isotope is increased to higher than the natural existent ratio, so that tritium ("3H) concentration in the hydrogen occluding material can be increased, to attain energy at high efficiency. (T.M.).

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Anorthosites are rocks consisting almost completely of calcic plagioclase, usually from andesine to labradorite. They are not widespread, and until recently were of no economic interest. However, with the advance of the new global tectonics, which has excited considerable interest in the structure and composition of upper-mantle rocks, interest in the anorthosites has grown. This has particularly been the case since the discovery of anorthosites on the moon, where they appear to be more widespread than on the earth. Data have recently been obtained on the strontium isotope compositions of anorthosite intrusions in the Dzhugdzhur-Stanovoy zone and in the rocks surrounding them, which have revealed some unexpected features. The paper describes the geological features of anorthosites, initial concepts on strontium isotope geochemistry, strontium isotope compositions of this region, and discusses some genetic consequences from ...

International Nuclear Information System (INIS)

Laser spectroscopy measurements have been performed on neutron-deficient iridium isotopes. The hyperfine structure and isotope shift of the optical Ir I transition 5d"76s"2 "4F_9_/_2#->#5d"76s6p "6F_1_1_/_2 have been studied for the "1"8"2"-"1"8"9Ir, "1"8"0Ir"m and "1"9"1","1"9"3Ir isotopes. The nuclear magnetic and quadrupole moments were obtained from the hyperfine splitting measurements and the changes of the mean square charge radii from the isotope shift measurements. A large deformation change between "1"8"7Ir and "1"8"6Ir and between "1"8"6Ir"m and "1"8"6Ir"g has been observed.

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Burnable poisons are used in nuclear reactors to produce a more level distribution of power in the reactor core and to reduce to necessity for a large control system. An ideal burnable poison would burn at the same rate as the fuel. In this study, separation of neutron-absorbing isotopes was investigated in order to eliminate isotopes that remain as absorbers at the end of fuel life, thus reducing useful fuel life. The isotopes Gd-157, Dy-164, and Er-167 were found to have desirable properties. These isotopes were separated from naturally occurring elements by means of plasma separation to evaluate feasibility and cost. It was found that pure Gd-157 could save approximately $6 million at the end of four years. However, the cost of separation, using the existing facility, made separation cost- ineffective. Using a magnet with three times the field strength is expected to reduce the cost by a factor of ...

International Nuclear Information System (INIS)

Daily intakes of certain trace elements (Pb, Cd, Ni, Hg, and Cr) were assessed using dietary history and weighed record methods and concurrent chemical analysis (CA) of duplicate portions, along with blood levels, in a group (21 M, 23 F) of inhabitants of the Gubbio area (Belvedere, Biscina Scritto). The evaluation of only intake of trace elements was accomplished in 40 subjects (20 M, 20 F) 1 year later. In both surveys, trace element intakes were generally lower than the potential tolerable weekly intake. However, daily intakes of Pb, Cd, Ni, Hg, and Cr were higher in men compared to women in both surveys (P<0.05). In fact, intakes at the 50th percentile were greater in men by approximately 75% for Pb, 91% for Cd, 20% for Ni, 45% fo Hg, and 29% for Cr in the first survey. In the second survey, percentage differences for Pb, Cd, Ni, and Cr were about 12%, 28%, 26%, and 26%, respectively. Blood trace ...

International Nuclear Information System (INIS)

Lead 203 has been used as a tracer for lead in the field of nuclear medicine for several years. It is produced in a cyclotron usually by proton or deuteron bombardment of a thallium target principally by the p,n or d,2n reaction on "2"0"3Tl or the p,3n or d,4n reaction on "2"0"5Tl. Several different methods have been reported for the separation of "2"0"3Pb from the thallium target. These generally involve a combination of precipitation and solvent extraction techniques. A new method has been developed for the separation of Pb from Tl using ion exchange chromatography over hydrous zirconium oxide (HZO). Lead is taken up by this inorganic ion exchanger at pH > 3 whereas Tl(I) is not. Lead can subsequently be eluted with acid of pH 1-1.5. The recovery of "2"0"3Pb has been approximately 75% and the Tl impurity level has not been in excess of 10 ppm. Reference is made to the application of this separation method to the ...

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This paper discusses the mineralogy and geochemistry of the No. 6 Coal (Pennsylvanian) in the Junger Coalfield, Ordos Basin, China. The results show that the vitrinite reflectance (0.58%) is lowest and the proportions of inertinite and liptinite (37.4% and 7.1%, respectively) in the No. 6 Coal of the Junger Coalfield are highest among all of the Late Paleozoic coals in the Ordos Basin. The No. 6 Coal may be divided vertically into four sections based on their mineral compositions and elemental concentrations. A high boehmite content (mean 6.1%) was identified in the No. 6 Coal. The minerals associated with the boehmite in the coal include goyazite, rutile, zircon, and Pb-bearing minerals (galena, clausthalite, and selenio-galena). The boehmite is derived from weathered and oxidized bauxite in the weathered crust of the underlying Benxi Formation (Pennsylvanian). A high Pb-bearing mineral content of samples ZG6-2 and ZG6-3 is likely of ...

International Nuclear Information System (INIS)

The role of dietary calcium and phosphorus in modifying the intestinal absorption of lead and also the effect of lead ingestion on the metabolism of cholecalciferol were studied in chicks. The efficiency of absorption of "2"0"3Pb and "4"7Ca was increased when the animals were fed a low calcium diet and treated with cholecalciferol. The synthesis of the vitamin D-induced calcium-binding protein (CaBP) was correspondingly increased. When the chicks were depleted of vitamin D and repleted with 1,25-dihydroxycholecalciferol [1,25(OH)_2D_3] as their only source of the vitamin, the absorption of both "4"7Ca and "2"0"3Pb was unaffected by dietary calcium levels, and no change in CaBP levels occurred. Low dietary intake of phosphorus resulted in an increase in "4"7Ca and "2"0"3Pb absorption and in CaBP synthesis when the animals were treated with cholecalciferol. However, when the birds were repleted with 1,25(OH)_2D_3, the ...

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The biosorption characteristics of Pb(II) and Cd(II) ions from aqueous solution using the green alga (Ulva lactuca) biomass were investigated as a function of pH, biomass dosage, contact time, and temperature. Langmuir, Freundlich and Dubinin-Radushkevich (D-R) models were applied to describe the biosorption isotherm of the metal ions by U. lactuca biomass. Langmuir model fitted the equilibrium data better than the Freundlich isotherm. The monolayer biosorption capacity of U. lactuca biomass for Pb(II) and Cd(II) ions was found to be 34.7 mg/g and 29.2 mg/g, respectively. From the D-R isotherm model, the mean free energy was calculated as 10.4 kJ/mol for Pb(II) biosorption and 9.6 kJ/mol for Cd(II) biosorption, indicating that the biosorption of both metal ions was taken place by chemisorption. The calculated thermodynamic parameters ({delta}G{sup o}, {delta}H{sup o} and {delta}S{sup o}) showed that the biosorption of ...

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The Archean core of the Laramide Wind River uplift records evidence of at least three major granitoid-forming episodes. The oldest, the Dry Creek gneiss (DCG), was emplaced by 2.8 Ga and occupies the northeastern part of the range. Mafic, pelitic and ultramafic inclusions occur in the DCG. Elsewhere in the Wind River Mountains there is evidence for crustal components as old as 3.8 Ga. The Bridger batholith (BB), intruded at 2.67 Ga, is found in the west-central Wind River Mountains. The Wind River batholith (WRB) refers to the youngest Late Archean granodiorites and granites which are found throughout the range and includes granitoids previously name the Louis Lake, Bears Ears, Popo Agie, and Middle Mountain intrusions. Although granitoids of the Wind River batholith have been dated at 2.63 and 2.55 Ga, they are considered together here because there is a complete gradation in rock type and because definite intrusive contacts are scarce. The DCG, BB, and WRB each span the ...

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The operation of a nuclear power reactor necessarily implies the consumption or burnup of reactor fuel by fission and capture, which gives rise to a decrease in the reactivity of the reactor. The effect of americium formation on the criticality of a thermal power reactor using two types of fuel is studied. The three-dimensional core calculation is used to calculate the production of the transuranium isotopes and their effect on the effective multiplication factor (K[sub eff]). This effect cannot be neglected for thermal power reactors with UO[sub 2]-PuO[sub 2] fuel (3.11% after 70 weeks of operation). The effect of the transuranium isotopes on the K[sub eff] for a thermal power reactor with UO[sub 2] fuel is about 0.0018% and can be ignored. (author).

Science.gov (United States)

The neutron-rich Mn isotopes from A=59 to 63 have been studied through multi-nucleon transfer reactions by bombarding a {sup 238}U target with a beam of {sup 70}Zn at an energy of E{sub lab}=460 MeV. Prompt {gamma} rays measured by the CLARA array have been identified unambiguously for each nucleus, using coincidence relationships with ions detected in the high-acceptance magnetic spectrometer PRISMA. The new data extends the knowledge of the low-lying level structure of Mn isotopes, which is discussed in terms of the systematics of the region. Results are compared with large-scale shell-model calculations using different effective interactions and valence spaces.

International Nuclear Information System (INIS)

Target materials for inertial fusion energy (IFE) power plant designs might be selected for a wide variety of reasons including wall absorption of driver energy, material opacity, cost and ease of fabrication. While each of these issues are of great importance, target materials should also be selected based upon their safety and environmental (S and E) characteristics. The present work focuses on the recycling, waste management and accident dose characteristics of potential target materials. If target materials are recycled so that the quantity is small, isotopic separation may be economically viable. Therefore, calculations have been completed for all stable isotopes for all elements from lithium to polonium. The results of these calculations are used to identify specific isotopes and elements that are most likely to be offensive as well as those most likely to be acceptable in terms of their S and E characteristics.

International Nuclear Information System (INIS)

This study concerns the Souss upstream basin. The objective is to investigate the characteristics of surface water and groundwater, to assess the impact of artificial recharge as reinforcement of the natural replenishment and assess the renewal of groundwater under semi-arid area. Two major water types are observed: (i) surface waters and upstream springs (least mineralized) and (ii) all groundwater samples (prevailing calcium and magnesium bicarbonate water type). Water isotopes show a low evaporation of precipitations during infiltration. Impoverishment in heavy isotopes is the characteristic of mountain rainfalls, or of a climate colder and wetter than present. Carbon-14 activities (34-94 pmc) indicate a long residence time. The artificial recharge is low compared to the reservoir volume, due to which the renewal rate is also low.

International Nuclear Information System (INIS)

The proton and neutron densities, root-mean-square (rms) radii of proton density and neutron density, and neutron skin thickness of "4"-"1"0He, "6"-"1"1Li, and "7"-"1"2Be isotopes are calculated using Skyrme-Hartree-Fock method with SLy4, SLy5, SLy6, and SLy7 force parameters. The evaluated results are compared with experimental data. Also, the results of halo nuclei ("6","8He, "1"1Li, and "1"1Be) are compared with the results of other isotopes for selected nuclei having the same neutron configuration.

International Nuclear Information System (INIS)

The dependence was determined of the decontamination factor ratio found in the presence of a carrier and in a carrier-free system on carrier concentration at different concentrations of a complexing agent in a solution. Bearing balls were used as contamination materials while a mixture of "1"5"2Eu and "1"5"4Eu isotopes was used as a contaminant, citric acid in a concentration of 5x10"-"3 to 1x10"-"1 mol/dm"3 as a complexing agent, and Eu, lanthanum and aluminium at a concentration range of 1x10"-"5 to 1x10"-"2 mol/dm"3 as carriers. While no increase in the decontamination factor was found for aluminium, a considerable increase was observed in the isotopic and homologic carriers and the concentration dependence of the carrier reached the maximum. An equation was derived explaining the effect by the isotope exchange between the contaminant and the carrier and by the reaction between the carrier and the complexing agent. ...

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Our goal was a process to convert methane to higher hydrocarbons oxidatively, since this circumvents thermodynamic yield limits of a strictly degydrogenative process. Keller and Bhasin converted thermodynamic yield limits of a strictly dehydrogenative process. Keller and Bhasin converted methane to higher hydrocarbons by using metal oxides as oxidants, without co-fed oxygen. They stated that selectivity is necessarily poor if gaseous oxygen is present. Jones and Sofranko have also used reducible metal oxides as oxidants in a group of their parents, but later used some of those materials with continuous O{sub 2} feed without much loss of selectivity. Baerns, Lunsford and Otsuka have shown that high selectivity could be possible with co-fed O{sub 2} at least for low O{sub 2} partial pressures, over PbO-A1{sub 2}O{sub 3}, Li-MgO and rare earths. The performance of a group of multicomponent oxide catalysts, containing lead and magnesium oxides, for oxidative conversion ...

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The distribution of lead in lactating mice and suckling offspring was studied with whole body autoradiography at 4 and 24 h after a single intravenous injection of {sup 203}Pb (50 mmol Pb/kg) to the dams. In the lactating mice on day 14 of lactation, the highest uptake of radioactivity at 4 h after administration was recorded in renal cortex, skeleton and liver. A high uptake was also evident in the mannary gland. At 24 h after administration, the radioactivity had decreased in most organs except in the skeleton. In the suckling pups, exposed to lead only via dams` milk for 24 h, the highest level of radioactivity was present in the intestinal mucosa and a much lower level of radioactivity was present in the skeleton. The mammary glands from mice given three daily intravenous injections of 240 {mu}mol Pb/kg were examined with X-ray microanalysis. At 4 h after the last injection, lead was found associated with casein ...

International Nuclear Information System (INIS)

In a Pb-Bi cooled direct contact steam generation fast reactor water is injected directly above the core, the produced steam is separated at the top and is send to the turbine. Neither the direct contact phenomenon nor the two-phase flow simulations in CFD have been thoroughly described yet. A first attempt in simulating such two-phase flow in 2D using the CFD code Fluent is presented in this paper. The volume of fluid explicit model was used. Other important simulation parameters were: pressure velocity relation PISO, discretization scheme body force weighted for pressure, second order upwind for momentum and CISCAM for void fraction. Boundary conditions were mass flow inlet (Pb-Bi 0 kg/s and steam 0.07 kg/s) and pressure outlet. The effect of mesh size (0.5 mm and 0.2 mm cells) was investigated as well as the effect of the turbulent model. It was found that using a fine mesh is very important in order to achieve larger bubbles and the ...

International Nuclear Information System (INIS)

The plans for the CERN LHC heavy ion program in 2010 are for collisions of lead ions during the month of November at an energy about half of the final 5.5 TeV/nucleon. The advanced preparations are mostly for extrapolations of the measurements at the maximum energy previously available, Au + Au at 0.2 TeV/nucleon. Because of the large increase in energy, surprises can be expected. One new feature made possible by the increased energy and the excellent muon energy resolution of CMS will be the study of the yields of the excited states of the upsilon meson as a function of angle and centrality. Although the main emphasis will be on the QGP formed by the overlapping parts of the Pb ions, the spectator parts and the electromagnetic field outside of the ions, #gamma#-Pb and #gamma##gamma#, are also important.

British Library Electronic Table of Contents (United Kingdom)

The aim of this study was to evaluate the differences in accuracy of dose calculation between 3 commonly used algorithms, the Pencil Beam algorithm (PB), the Anisotropic Analytical Algorithm (AAA), and the Collapsed Cone Convolution Superposition (CCCS) for intensity-modulated radiation therapy (IMRT). The 2D dose distributions obtained with the 3 algorithms were compared on each CT slice pixel by pixel, using the MATLAB code (The MathWorks, Natick, MA) and the agreement was assessed with the gamma function. The effect of the differences on dose-volume histograms (DVHs), tumor control, and normal tissue complication probability (TCP and NTCP) were also evaluated, and its significance was quantified by using a nonparametric test. In general PB generates regions of over-dosage both in the l...

International Nuclear Information System (INIS)

The results of real-time neutron diffraction measurements during the superconducting phase formation process in the Bi(Pb)-Sr-Ca-Cu-O system are reported. A Sr-Ca-Cu-O type precursor, with the same stoichiometry as the 2223 phase, was used as starting material, and the temperature range favorable to the formation of the 2223 phase was investigated. The diffraction patterns were processed by a multiphase Rietveld refinement. The formation and decomposition of the 2201 and 2212 phases were directly observed. Experimental evidence on the existence of a partially melted phase in the range 855-860 degrees C, involved in the formation of the 2223 phase, is discussed. 14 refs., 9 figs., 1 tab.

International Nuclear Information System (INIS)

An overview on neutron scattering studies of ferromagnetic and antiferromagnetic all-semiconductor superlattices is presented. Diffraction experiments on MnTe/CdTe, MnTe/ZnTe and EuTe/PbTe superlattices show pronounced correlations between the MnTe and EuTe layers across the non-magnetic spaces, even though these layers are antiferromagnetic and the systems are nearly-insulating. Current theory status of these systems is discussed. Diffractometry and reflectometry data from EuS/PbS superlattices reveal pronounced antiferromagnetic coupling between the ferromagnetic EuS block. First polarized neutron reflectometry data from superlattices prepared of a novel ferromagnetic 'spintronics' material, Ga(Mn)As are also presented. (author)

British Library Electronic Table of Contents (United Kingdom)

Human exposure to environmental chemicals is most correctly characterized as exposure to mixtures of these agents. The metals/metalloids, lead (Pb), cadmium (Cd), and arsenic (As), are among the leading toxic agents detected in the environment. Exposure to these elements, particularly at chronic low dose levels, is still a major public health concern. Concurrent exposure to Pb, Cd, or As may produce additive or synergistic interactions or even new effects that are not seen in single component exposures. Evaluating these interactions on a mechanistic basis is essential for risk assessment and management of metal/metalloid mixtures. This paper will review a number of individual studies that addressed interactions of these metals/metalloids in both experimental and human exposure studies with...

International Nuclear Information System (INIS)

In the Carpathian Basin, significant percentage of watershed area and floodplains of rivers are utilised agriculturally. Several potential sources of poisonous metal pollution have been identified in these areas. Because of spills from some of them a few severe accidents have happened especially in the watershed area of Tisza River during the last decades. The motivation of our present work was to produce "6"2","6"5Zn and "2"0"3Pb radioisotopes because they can be used especially as tracers for studying the kinetics of uptake, transport and accumulation of zinc and lead by plants under different circumstances. (orig.)

Energy Technology Data Exchange (ETDEWEB)

The biosorption of lead, copper and zinc ions on Rhizopus arrhizus has been studied for three single-component and two binary systems. The equilibrium data have been analysed using the Freundlich adsorption model. The characteristic parameters for the Freundlich adsorption model have been determined and the competition coefficients for the competitive biosorption of Pb(II)-Cu(II) at pH 4.0 and 5.0, and Pb(II)-Zn(II) at pH 5.0 have been calcualted. For the individual single-component isotherms, lead has the highest biosorption capacity followed by copper, then zinc. The capacity of lead in the two binary systems is always significantly greater than those of the other metal ions, in agreement with the single-component data. Only a partial selectivity for copper ions has been obtained at pH 4.0. (orig.)

International Nuclear Information System (INIS)

The effect of both dopant and neutron radiation on the optical and thermal properties of polyvinyl chloride (PVC) has been studied. The doped samples with Pb and Cd were irradiated with a 14 MeV-neutron fluence in the range 7-28.8 x 10"9 n/cm"2. The optical energy gap E_o_p exhibits a significant dependence on the type of additive and the neutron irradiation fluence. The specific heat at constant pressure C_p showed a nonmonotonical change with radiation fluence. The results of this study show that PVC:Pb behaves as a crystalline structure which is only slightly affected by neutron irradiation, while PVC:Cd is highly affected. (author).

International Nuclear Information System (INIS)

The electronic structures of BaSnO_3, BaSbO_3, and BaPbO_3, calculated using an extended general-potential linearized augmented-plane-wave method, are reported. The electronic structures of BaSnO_3 and its 6s analog BaPbO_3 are found to be very different, explaining the absence of superconductivity in the Ba(Sn,Sb)O_3 system. These differences are explained by a combination of the relativistic lowering of the 6s states and ion-size effects. Muffin-tin-approximation augmented-plane-wave calculations for BaSnO_3 are also reported and the utility of the muffin-tin approximation for this and similar materials is discussed in terms of the differences between the two sets of calculations.

British Library Electronic Table of Contents (United Kingdom)

In [W. Ye, F. Wu, H.W. Yang, Phys. Lett. B 647 (2007) 118] prescission protons and ? particles of high-isospin 206Pb were shown to be almost independent of the dissipation strength Formula Not Shown . Subsequently, in [P.N. Nadtochy, et al., Phys. Lett. B 685 (2010) 258] prescission light charged particles (LCPs) were shown to have approximately the same sensitivity as neutrons to Formula Not Shown for 206Pb and 204Hg nuclei. In this Letter we point out that the reason for the apparent contradictory conclusions is that the authors in the latter did not compute the changes in the absolute yields of prescission LCPs multiplicities with increasing Formula Not Shown and compare them with typical experimental uncertainties. It is shown that the expected changes are very small in the case of ne...

British Library Electronic Table of Contents (United Kingdom)

To reconstruct the profiles of heavy metal levels in the South Ocean ecosystem of Antarctica, the concentrations of lead (Pb), copper (Cu), arsenic (As), cadmium (Cd), and zinc (Zn) in seal hairs and lake sediments spanning the past 1500?years from Fildes Peninsula of King George Island and in weathering lake sediments from Nelson Island of West Antarctica were determined. The lead contents in the seal hairs and the weathering sediments show a sharp increase since the late 1800s, very likely due to anthropogenic contamination from modern industries. After the 1980s, the Pb content in seal hairs dropped by one-third, apparently due to the reduced usage of leaded gasoline in the Southern Hemisphere. Copper arises mainly from the weathering process, and its level may be substantially affected...

UK PubMed Central (United Kingdom)

ObjectivesTo assess the distribution and risk factors of depleted uranium uptake in military personnel who had taken part in the invasion of Iraq in 2003.MethodsSector...Full Text Available

UK PubMed Central (United Kingdom)

Although deep-sea cephalopods are key marine organims, their feeding ecology remains essentially unknown. Here, we report for the first time the trophic structure of an assemblage of these animals (19...Full Text Available