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 ...

CERN Document Server

beta- and gamma-decay studies of neutron-rich chromium, manganese, cobalt and nickel isotopes including the new isotopes $^{60}$Cr and $^{60g}$Mn

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 ...

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.

International Nuclear Information System (INIS)

Reliable and consistent characterization of the stable isotope composition of atmospheric water vapour and its temporal variability are important prerequisites to the wider application of isotope mass balance methods in atmospheric and water balance studies. A new approach is proposed which utilizes standard class-A evaporation pans, which have sufficient volume to buffer short-term transient variations in atmospheric conditions, justifying the assumption of constant kinetic isotopic fractionation effects in concert with precisely measured temperature and relative humidity to derive vapour isotopic composition. The results of the studies suggest that isotopic sampling of existing, conventionally operated class-A evaporation pans could offer a straightforward and cost-effective solution to the problem of documenting the shifting ...

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 sequences of the MTZ in Nelson and eastern ...

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 ...

International Nuclear Information System (INIS)

... air pollution coprecipitation isotope production lead 203 proton beams

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.

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.)

Energy Technology Data Exchange (ETDEWEB)

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.

Science.gov (United States)

The gadolinium isotopes are interesting for reactor applications as well as for medicine and astrophysics. The gadolinium isotopes have some of the largest neutron capture cross sections. As a consequence they are used in the control rod in reactor fuel assembly. From the basic science point of view, there are seven stable isotopes of gadolinium with varying degrees of deformation. Therefore they provide a good testing ground for the study of deformation dependent structure such as the scissors mode. Decay gamma rays following neutron capture on Gd isotopes are detected by the DANCE array, which is located at flight path 14 at the Lujan Neutron Scattering Center at Los Alamos National Laboratory. The high segmentation and close packing of the detector array enable gamma-ray multiplicity measurements. The calorimetric properties of the DANCE array coupled with the neutron ...

International Nuclear Information System (INIS)

Lead is contained as trace element in uranium ores and propagates throughout the production process to intermediate products like yellow cake or uranium oxide. The lead isotopes in such material originate from two sources: natural lead and radiogenic lead. The variability of the isotopic composition of lead in ores and yellow cakes was studied and the applicability of this parameter for nuclear forensic investigations was investigated. Furthermore, the chemical impurities contained in these materials were measured in order to identify characteristic differences between materials from different mines. For the samples investigated, it could be shown, that the lead isotopic composition varies largely from mine to mine and it may be used as one of the parameters to distinguish between materials of different origins. Some of the chemical impurities show a similar pattern and support the conclusions drawn ...

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.

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 ...

International Nuclear Information System (INIS)

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.

Energy Technology Data Exchange (ETDEWEB)

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 ...

International Nuclear Information System (INIS)

Hydrology and hydrogeochemical are auxiliary techniques to valid conceptual hydrogeology an recharge models. Stable isotopes from water trace sources and path flow and Tritium indicates age. This paper is about the use of D 18, D2H y 3H to study the aquifer system on Bajo Cauca antioqueno.

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.

Energy Technology Data Exchange (ETDEWEB)

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.

Energy Technology Data Exchange (ETDEWEB)

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.

Energy Technology Data Exchange (ETDEWEB)

New isotopic age determinations carried out with the rubidium-strontium method on granodioritic basement rocks from the Mecsek Mountains in Southeastern Transdanubia give further support to assumptions on a polyphase development of the Mecsek crystalline. As shown by initial Sr isotopic ratios, the protolith of the granodioritic assemblage of polymetamorphic-anatectic origin must have been strongly basic in its composition. The scatter of individual model ages obtained on total rock samples reflects the polymetamorphic-polytectonized character of the basement, and suggests that following a primary granitization process secondary events might have led to the total or partial recrystallization of the rocks in question. The tectonic development of the basement crystalline as reflected in the isotopic age data closed at about 270+-20 million years ago, with processes causing retrograde changes in the crystalline as a whole but ...

Energy Technology Data Exchange (ETDEWEB)

The invention is associated with organic geochemistry and may be used in conducting geological exploration operations for oil and gas. The purpose of the invention is to increase the precision of the method for determining the genesis of bitumoids. This is achieved through determining the isotopic composition of nickel or vanadium and from the anomalously high values of the isotopic ratio of Ni-58 to Ni-62 or from the anomalously low values of the isotopic ratio of vanadium, a conclusion is drawn about the epigenetic nature of the bitumoids. The proposed method is characterized by greater resolution due to the fact that the values of the isotopic ratios for oil bearing and water bearing structures are essentially not superimposed. The proposed method exceeds the resolution of metal metering studies in conducting geological exploration for oil and gas by 2 to 3 times.

International Nuclear Information System (INIS)

... lutetium isotopes nuclei odd-even nuclei radioisotopes rhenium isotopes

Energy Technology Data Exchange (ETDEWEB)

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 ...

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.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

The distribution of carrier free lead-203 between plasma and cells of canine blood in vitro was measured. Activity in the plasma decreased to less than 5% of the initial blood activity during the first 15 min and then exponentially with a half time of 160 min. Incubation in cell free plasma before addition to whole blood transformed the isotope, decreasing the amount subsequently associated with cells. In animal studies, activity was measured in plasma, blood cells, urine, and feces after exposure to lead-203. In one group, the animals were exposed by intravenous injection of dilute citric acid solutions of isotope. In a second group, carrier free isotope which had been transformed by incubation in plasma was injected intravenously. The kinetics of the distribution of the isotope differed between the two experimental groups. After injection of the transformed lead, the lead-203 ...

International Nuclear Information System (INIS)

We describe a compact ultrafiltration system for the removal of pyrogens and bacteria from water labeled with the stable isotopes of deuterium and oxygen-18. The ultrafiltration system is constructed from readily available commercial components and can achieve complete removal of pyrogens and bacteria from 1L contaminated water within 30 min. By use of our procedure, loss of the isotopically labeled water by retention in the filtration system was minimal. The purified water is suitable for both oral and intravenous administration to healthy human subjects participating in nutrition studies.

International Nuclear Information System (INIS)

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_e_f_f). This effect cannot be neglected for thermal power reactors with UO_2-PuO_2 fuel (3.11% after 70 weeks of operation). The effect of the transuranium isotopes on the K_e_f_f for a thermal power reactor with UO_2 fuel is about 0.0018% and can be ignored. (author).

International Nuclear Information System (INIS)

The neutron-rich Mn isotopes from A=59 to 63 have been studied through multi-nucleon transfer reactions by bombarding a "2"3"8U target with a beam of "7"0Zn at an energy of E_l_a_b=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.

Energy Technology Data Exchange (ETDEWEB)

The known biological functions of RNA have expanded in recent years and now include gene regulation, maintenance of sub-cellular structure, and catalysis, in addition to propagation of genetic information. As for proteins, RNA function is tightly correlated with structure. Unlike proteins, structural information for larger, biologically functional RNAs is relatively limited. NMR signal degeneracy, relaxation problems, and a paucity of long-range {sup 1}H-{sup 1}H dipolar contacts have limited the utility of traditional NMR approaches. Selective isotope labeling, including nucleotide-specific and segmental labeling strategies, may provide the best opportunities for obtaining structural information by NMR. Here we review methods that have been developed for preparing and purifying isotopically labeled RNAs, as well as NMR strategies that have been employed for signal assignment and structure determination.

Energy Technology Data Exchange (ETDEWEB)

This work is based on the study of cesium ({sup 118,146}Cs) and francium ({sup 207-213}Fr,{sup 220-228}Fr) isotopes by hyperfine atomic spectroscopy and on the interpretation of these results from the nuclear physics point of view. The measured nuclear quantities are: the spin, the magnetic moment, the electric quadrupole moment and the mean square charge radius. The experimental method which is based on hyperfine optical pumping with a tunable laser, followed by magnetic analysis of the atoms is described in the first part. Results related to atomic physics are also presented. In the second part, these data are interpreted in the framework of nuclear models. The deformation of light cesium isomers are compared to values obtained from a theoretical self-consistent calculation. Heavy francium isotopes are situated in an area where the existence of static octupole deformations have been predicted. The odd-even staggering ...

Energy Technology Data Exchange (ETDEWEB)

The objective of this research was to determine improved thermal, epithermal, and fast fluxes and several responses at mechanical test surveillance location keys 2, 4, 5, and 7 of the pressure vessel of the Oak Ridge National Laboratory High Flux Isotope Reactor (HFIR) for the beginning of the fuel cycle. The purpose of the research was to provide essential flux data in support of radiation embrittlement studies of the pressure vessel shell and beam tubes at some of the important locations.

International Nuclear Information System (INIS)

Photoluminescence spectra for solutions containing Sm"3"+ isotope ions in heavy and normal water were studied in the wave length #lambda# = 500-700 nm and for absorption spectra and photoluminescence excitation spectra within the range of #lambda# = 260-600 nm. Differences in molar extinction coefficients for "1"4"4Sm"3"+ and "1"5"4Sm"3"+ were established both in the solutions with D_2O and by transition from the solutions with D_2O to the solutions with H_2O. New possible causes of the identified effects are discussed

International Nuclear Information System (INIS)

Beta-decay studies of the new neutron-rich isotopes sup(58,59)Cr, "6"3Mn, sup(66,67)Co and "6"9Ni, yielding distinctly shorter half-lives than the corresponding theoretical predictions, are presented. The influence of the short half-lives on the r-process calculations of nuclear abundances is discussed. It is concluded that a significantly higher neutron density than the one obtained from explosive helium burning in supernovae is needed to reproduce the observed abundances around A = 80. (orig.).

Energy Technology Data Exchange (ETDEWEB)

Laser spectroscopy measurements have been performed on neutron deficient iridium isotopes. The hyperfine structure and isotope shift of the optical Ir I transition 5d{sup 7}6s{sup 24}F{sub 9/2} {sup {yields}} 5d{sup 7}6s6p {sup 6}F{sub 11/2} at 351.5 nm have been studied for the {sup 182-189}Ir, {sup 186}Ir{sup 1}m and {sup 191,193}Ir isotopes. The nuclear magnetic and quadrupole moments were obtained from the HFS measurements and the changes of the mean square charge radii from the IS measurements. A large mean square charge radius change between {sup 187}Ir and {sup 186}Ir and between {sup 186}Ir{sup 1}m and {sup 186}Ir{sup 1}g has been observed.

Energy Technology Data Exchange (ETDEWEB)

A method for quick, high-accuracy measurement of lithium isotopes has become necessary in carrying out research on the separation and concentration of lithium isotopes by ion exchange. The present report focuses on the application of a hollow cathode, as excitation source, to emission spectral analysis for lithium isotope measurement. The grating monochromator used incorporates a pressure scanned etalon. With decreased Doppler broadening and pressure broadening, the hollow cathode, used as excitation source, can give narrow spectral lines, permitting good separation among them. To achieve a high accuracy, the emission intensity of the hollow cathode should be maintained as stable as possible relative to time. In particular, the stability of a light source can be affected significantly by the chemical form of the sample. A study is also made here to identify a condition where lithium acetate effluent ...

Energy Technology Data Exchange (ETDEWEB)

A combination of /sup 18/O-labeling experiments and kinetic studies to clarify the nonenzymatic hydrolytic pathways of adenosine 5'-triphosphate (ATP) at pH values ranging from 0 to 8.3 has been used in this experiment. In 1 N and 0.1 N HCl, the data are consistent with the hypothesis that hydrolysis occurs by addition-elimination, with initial attack 93% ..gamma.. and 7% ..beta..; both lead only to ADP + P/sub i/. In the subsequent hydrolysis of the ADP to AMP + P/sub i/, attack is 83% ..beta.. and 17% ..cap alpha... At pH 8.3, the data are consistent with the hypothesis that hydrolsysis occurs by elimination-addition. Over the entire pH range studied, no oxygen exchange between water and ATP, ADP, or P/sub i/ was detected. Nonenzymatic hydrolysis and isotopic analysis of the resultant P/sub i/ comprise a preferred means of assaying the isotopic enrichment of (..gamma..-/sup 18/O)ATP to be ...

International Nuclear Information System (INIS)

Synthesis of the azido substituted non-steroidal anti-inflammatory drug 2-(2,6-dichloroanilino)phenylacetic acid and isotope labeling of this compound have been performed and are described. Initial evaluation of the binding ability and photoreactivity indicates that this compound has potential for photoaffinity labeling as well as enzyme selectivity studies. (author).

UK PubMed Central (United Kingdom)

Interactions of myristic acid with bovine serum albumin were studied by 13C NMR spectroscopy at 50.3 MHz using 90% isotopically substituted [1-13C]-, [3-13C]-, and [14-13C]myristic acids, either individually...Full Text Available

International Nuclear Information System (INIS)

All stable even-A molybdenum isotopes and sup(90,92)Zr have been investigated with the (d, "6Li) reaction at Esub(d) = 45 MeV to study proton- and neutron-pair correlations. Differential cross sections were measured for states up to Esub(x) = 3 MeV in "8"6Sr, sup(88,92,94,96)Zr and up to 6 MeV in "8"8Sr and "9"0Zr. Particular attention was paid to the comparison of #alpha#-pickup data with two-nucleon pickup data. The population of low-lying 0"+ and 5"- states for two-neutron and four-nucleon pickup reactions was calculated using simple phenomenological wave functions for the initial and final states. The results of these calculations are in satisfactory agreement with the data. (orig.).

International Nuclear Information System (INIS)

The Co-ordinated Research Programme (CRP) on ''Isotope-Aided Studies on the Bioavailability of Iron and Zinc from Human Diets'' was initiated by the IAEA in 1990, and presently encompasses participating institutes in 11 countries. A summary of the discussions that took place during thr second Research Co-ordination Meeting held in Hyderabad, India, between 16-20 November 1992, is given in this report together with 12 working papers (progress reports) presented by individual participants. A separate abstract was prepared for each of these papers. Refs, figs and tabs.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

International Nuclear Information System (INIS)

Abstract only.

International Nuclear Information System (INIS)

The measurements of the nuclear decay of actinide isotopes and the evaluation of the radioactive properties of nuclide with the mass 242 is discussed in this paper.

International Nuclear Information System (INIS)

Penning trap mass spectrometry is presented as a complementary tool to nuclear spectroscopy experiments for the study of nuclear structure in the vicinity of N=40, Z=28. High-precision mass measurements of the "6"3"-"6"6Fe and "6"4"-"6"7Co isotopes have been carried out with the Low Energy Beam and Ion Trap (LEBIT) Penning trap mass spectrometer. The newly obtained mass values for "6"6Fe and "6"7Co are presented, together with the previously reported LEBIT mass measurements in this region. In the case of "6"5Fe the existence of a new isomer is reported, and an isomer recently discovered by decay spectroscopy in "6"7Co is confirmed. Relative mass uncertainties as low as 4x10"-"8 are obtained. All mass values are found to be in good agreement with previous experimental results with the exception of "6"4Co, where a 5#sigma# deviation is observed. Using these data the two neutron separation energies S_2_n are calculated. However, the large error ...

British Library Electronic Table of Contents (United Kingdom)

The Alpine Foreland Basin is a minor oil and moderate gas province in central Europe. In the Austrian part of the Alpine Foreland Basin, oil and minor thermal gas are thought to be predominantly sourced from Lower Oligocene horizons (Schoneck and Eggerding formations). The source rocks are immature where the oil fields are located and enter the oil window at ca. 4 km depth beneath the Alpine nappes indicating long-distance lateral migration. Most important reservoirs are Upper Cretaceous and Eocene basal sandstones.Stable carbon isotope and biomarker ratios of oils from different reservoirs indicate compositional trends in W-E direction which reflect differences in source, depositional environment (facies), and maturity of potential source rocks. Thermal maturity parameters from oils of di...

Energy Technology Data Exchange (ETDEWEB)

Possible accident scenarios for a fusion reactor include breaches in the vacuum or cooling system. Intruding air or steam could react with structural or plasma facing materials, possibly mobilizing radioactive isotopes. Safety assessments must consider the early dose at the site boundary from the release of these activated materials. Previous calculations have indicated that cobalt isotopes dominate dose calculations for designs using stainless steel. Values used in these calculations, however, had been largely determined by the measurement limits of the chemical analysis methodology instead of measured releases. The purpose of the current study was to refine the analytical method to reduce the limit for detecting cobalt, and then test PCA steel in air and steam between 973 and 1473 K. Goals were to obtain more accurate measurements of cobalt mobilization in terms of g/m{sup 2}{center_dot}h and insight into the mobilization ...

International Nuclear Information System (INIS)

Lanthanum halide (LaBr_3:Ce) scintillators offer significantly better resolution (< 3% at 662 keV) relative to NaI(Tl) and have recently become commercially available in sizes large enough for the handheld, Radio-Isotope Identification Device (RIID) market. Drawbacks to lanthanum halide detectors, however, include internal radioactivity contributing to spectral counts, and a low-energy response which can cause detector resolution to be worse than that of NaI(Tl) below 100 keV. To study the potential of this new material for RIIDs we performed a series of measurements comparing a 1.5 x 1.5-inch LaBr_3:Ce detector with an Exploranium GR-135 RIID, which contains a 1.5 x 2.2-inch NaI(Tl) detector. Measurements were taken for short timeframes, as typifies RIID usage. Measurements included examples of naturally occurring radioactive material (NORM), typically found in cargo, and special nuclear materials. Some measurements were non-contact, ...

International Nuclear Information System (INIS)

The CLARA-PRISMA setup, composed of an array of 25 Clover detectors placed at the target position of the magnetic spectrometer PRISMA, has recently concluded its campaign to study the structure of moderately neutron-rich nuclei. In this contribution, results obtained in the vicinity of the doubly-magic nucleus "4"8Ca are presented, together with results obtained for the heavy iron isotopes. The perspectives offered by the forthcoming operation of the AGATA Demonstrator Array coupled to PRISMA are also discussed. (author)

Energy Technology Data Exchange (ETDEWEB)

The neutron deficient Sr and Zr nuclei are studied in the relativistic mean-field approach. Large deformations and shape coexistence are predicted for these nuclei in the vicinity of the proton drip line. The charge radii are found to increase with the removal of neutrons from the semimagic {sup 88}Sr and {sup 90}Zr, in close agreement with the recent isotopic-shift measurements.

International Nuclear Information System (INIS)

Isotopically selective IR multiphoton dissociation of molecules (SF_6, CF_3I) in a pulsed gas-dynamic flow interacting with a solid surface was studied for the first time. A noticeable (severalfold) increase in the yield of products (compared to excitation of molecules in an unperturbed flow) without a substantial decrease in the selectivity of the process was observed. Possible reasons for the effect are discussed. (laser applications and other topics in quantum electronics)

Energy Technology Data Exchange (ETDEWEB)

The authors attemps to confirm a modification of the phase-absprotion method applicable to the study of the decay rate of energy stored in the upper level in the active medium of a CO/sub 2/-laser. The essence of the method is described. Relationships are determined which allow one to obtain the unknown parameters of the experimentally measured phase shift. The work exeprimentally shows the possibility of studying vibratioanl relaxation in the active medium of a CO/sub 2/-laser by the phase-absorption method using both ordinary and isotope-substitued molecules.

International Nuclear Information System (INIS)

Neutron-rich He-, Li-, and Be-isotopes in the vicinity of the drip-line have been studied by "1"2C- and "1"4C-induced multi-nucleon transfer reactions on "1"0Be and "1"3","1"4C-targets. This study revealed unknown excited states in "8","1"0He, "1"0","1"1Li and in "1"3","1"4Be. Both excitation energies and widths have been measured. In some cases most probable spins and parities could be assigned to the particle-unstable states observed. (orig.).

International Nuclear Information System (INIS)

To support the Space Exploration Initiative (SEI), a study was performed to investigate power system alternatives for the rover vehicles and servicers that were subsequently generated for each of these rovers and servicers, candidate power sources incorporating various power generation and energy storage technologies were identified. The technologies were those believed most appropriate to the SEI missions, and included solar, electrochemical, and isotope systems. The candidates were characterized with respect to system mass, deployed area, and volume. For each of the missions a preliminary selection was made. Results of this study depict the available power sources in light of mission requirements as they are currently defined.

Energy Technology Data Exchange (ETDEWEB)

The genetic type, source and charging history of natural gas in the Yulin gas field in the Ordos Basin have been studied by combining the carbon isotopic composition of natural gas and geochemical characteristics of light hydrocarbons with carbon isotope fractionation model results and fluid inclusion analysis. The carbon isotopic composition of methane and ethane in the Yulin gas field is relatively enriched in {sup 13}C with {delta}{sup 13}C{sub 1} values ranging from - 35.3 permille to - 29.8 permille (average value = - 32.4 permille) and {delta}{sup 13}C{sub 2} ranging from - 26.3 permille to - 23.5 permille (average value = - 24.8 permille). The C{sub 7} light hydrocarbons are predominated by methylcyclohexane, accounting for 65.8% to 80.9% (average value = 71.6%), which is characteristic of coal-derived gas. Furthermore, the gas geochemistry indicates that, although marine limestone source rocks ...

International Nuclear Information System (INIS)

The liquid-liquid extraction behavior of short-lived molybdenum and tungsten isotopes from HCl and HNO_3 as well as HF/HNO_3 acid media was studied using the #alpha#-benzoinoxime/chloroform system. The goal of the present experiments was to find an extraction system with a high selectivity for the group 6 elements in the periodic table which is suitable for the study the solution chemistry of seaborgium (Z = 106). It was found that Mo and W are both effectively extracted using #alpha#-benzoinoxime as an extractant and the maximum extraction yield is 100% and 94% for Mo and W, respectively. Ions of MO_2"2"+ (M = Mo, W) exist in HCl between the concentration range of 0.1-3 M and can be extracted quantitatively into the organic phase. The decrease of extraction yields at lower or higher acid concentration is due to the formation of anionic species MO_4"2"- or MO_2Cl_3"-. The extraction behavior of Mo and W in HNO_3 solution is ...

International Nuclear Information System (INIS)

Beach rocks are observed frequently on the tropical and subtropical sandy beaches where they express thin beds dipping seaward at less than 15 degrees. They consist of beach sediments including fossil shells, fragments of corals, diatoms and other biocarbonates, and are well cemented within the inter-tidal zone with calcium carbonate originated in sea water. Therefore, they are not only good indicators which show the past sea level, but also provide good sample material for radiocarbon dating. The locations of beach rocks give us an optimum condition studying a carbon cycle between land and marine environment by analyzing their isotope fractionations. In order to estimate the origin of calcium carbonate which worked as an adhesive when beach rocks were formed and to estimate the formative ages of beach rocks, a total of 330 fossil corals, fossil shells and calcarenite or calcirdite samples were collected from 128 sites of 16 islands consisting ...

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.)

International Nuclear Information System (INIS)

Measurements of gamma-ray spectra, following the thermal neutron fission of "2"3"5U have been made using a high purity germanium detector at the University of Massachusetts Lowell (UML) Van de Graaff facility. The gamma spectra were measured at delay times ranging from 0.2 s to nearly 10000 s following the rapid transfer of the fission fragments with a helium-jet system. On the basis of the known gamma transitions, forty isotopes have been identified and studied. By measuring the relative intensities of these transitions, the relative yields of the various precursor nuclides have been calculated. The results are compared with the recommended values listed in the ENDF/B-VI fission product data base (for the lifetimes and the relative yields) and those published in the Nuclear Data Sheets (for the beta branching ratios). This information is particularly useful for the cases of short-lived fission products with lifetimes of the order of fractions ...

International Nuclear Information System (INIS)

We studied the magnetic dipole moments #mu# of even-odd C isotopes, ranging from proton-rich to neutron-rich nuclei, with antisymmetrized molecular dynamics (AMD). The results are in good agreement with the experimental data. In the "9C ground state the total intrinsic spin of the protons is found to be nonzero (S_p#not =#0), which is unusual in even-odd nuclei. The interesting point is that the spin-orbit force breaks slightly the coupling off of intrinsic spins of the even nucleon group in isospin T=3/2 nuclei. This result is consistent with the newly measured #mu# data that, when combined with "9Li data, indicate an unusual left-angle #sigma# right-angle value larger than unity. A #mu# moment -1.05#mu#_N of "1"7C is theoretically predicted. We also show a good reproduction of E2 transition data. copyright 1996 The American Physical Society.

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)

The improved facilities of the ISOLDE isotopic separator on-line with the 600 MeV synchrocyclotron at CERN opened the possibility to reach nuclei very far from stability (as far as 22 neutrons deficient in the Cs region and 27 neutrons deficient in the Hg region). Simultaneously the development of on-line spectrometry allowed the study of nuclei with very short half-lives and low counting rates. Results recently obtained in the odd-A iridium region are presented after a short summary of recent on-line devices developments and results. (Auth.).

Energy Technology Data Exchange (ETDEWEB)

Evaluated spectroscopic data for all nuclei with mass number A = 177 and corresponding level schemes from radioactive decay and reaction studies are presented. Most of the new information since the previous evaluation of this mass chain consists of the decay of the recently discovered isotope [sup 177]Tm, and the level structure of [sup 177]Ir, [sup 177]Os, and [sup 177]Pt. The present evaluation supersedes the earlier one by Y. A. Ellis and B. Harmatz (75E107) published in Nuclear Data Sheets 16, 135 (1975).

British Library Electronic Table of Contents (United Kingdom)

LUCIFER (Low-background Underground Cryogenic Installation For Elusive Rates) is a new project for the study of neutrinoless Double Beta Decay, based on the technology of scintillating bolometers. These devices promise a very efficient rejection of the alpha background, opening the way to a virtual background-free experiment if candidates with a transition energy higher than 2615 keV are investigated. The baseline candidate for LUCIFER is 82Se. This isotope will be embedded in ZnSe crystals grown with enriched selenium and operated as scintillating bolometers in a low-radioactivity underground dilution refrigerator. In this paper, the LUCIFER concept will be introduced. The sensitivity and the very promising prospects related to this project will be discussed.

Energy Technology Data Exchange (ETDEWEB)

Neutron deficient nuclei with mass numbers A {approx} 90 and 40 {<=} Z {<=} 44 have been studied making use of the Osiris and Nordball spectrometers. The high spin states of these nuclei and their electromagnetic decay properties are compared to shell model calculations based on the core {sup 88}Sr and using different parametrizations of the residual interaction. The dependence of the mean square deviations of experimental and theoretical level energies, branching ratios, and transition probabilities on the neutron numbers N = 46-50 and the validity of seniority as a good quantum number are discussed. (orig.).

Energy Technology Data Exchange (ETDEWEB)

The proposed short wavelength coherent light source driven by the SLAC 3 km linac might be used to induce transitions between nuclear isomeric states. If an isotope were found with energetically adjacent isomeric states, one short-lived and one long-lived, and it were possible to separate and concentrate the long-lived species, and other nuclear and solid-state parameters were favorable, it might be possible to convert sufficient population to the short-lived state to realize {gamma}-ray lasing. Even if the x-ray intensity were insufficient, study of such driven transitions would be quite valuable.

Energy Technology Data Exchange (ETDEWEB)

This study was undertaken during 1991 - 1998 to identify the origin of plutonium uranium in northern New Mexico Rio Grande and tributary stream sediments. Isotopic fingerprinting techniques help distinguish radioactivity from Los Alamos National Laboratory (LANL) and from global fallout or natural sources. The geographic area covered by the study extended from the headwaters of the Rio Grande in southern Colorado to Elephant Butte Reservoir in southern New Mexico. Over 100 samples of stream channel and reservoir bottom sediments were analyzed for the atom ratios of plutonium and uranium isotopes using thermal ionization mass spectrometry (TIMS). Comparison of these ratios against those for fallout or natural sources allowed for quantification of the Laboratory impact. Of the seven major drainages crossing LANL, movement of LANL plutonium into the Rio Grande can only be traced via Los Alamos Canyon. The ...

Energy Technology Data Exchange (ETDEWEB)

The large girth and immense size of the baobab has caused many to speculate about its age. Unfortunately reliable age estimates cannot be determined from growth rates as the girth varies in response to different moisture regimes. In a similar way, ages cannot be determined from ring-width measurements or X-ray densitometry as the absorbent nature of the soft fibrous wood and distortion upon drying prevent the application of these techniques. The Southern Hemisphere bomb radiocarbon curve was used to demonstrate that the rings of a recently-fallen baobab (Adansonia digitata L.) from Kruger National Park appear to be annual. The detrended C isotope values of finely-ground wholewood from another baobab specimen were found to be highly associated with January precipitation (r = 0.72; p < 0.01). This study demonstrates that high resolution information about past climates may be obtained by analysing the C isotope values ...

Energy Technology Data Exchange (ETDEWEB)

Cryogenic distillation is the main industrial method for separating hydrogen's isotopes, because it presents the advantage of high separating factors and also the possibility of processing great quantities of gases. In the case of multicomponent mixtures the determination of transport for molecular species between the two phases is very difficult owing to the particularities of physical characteristics of each component from the mixture. The transport of molecular species is also strongly influenced by the hydrodynamics of two phases, in strong connection with the dimension of the interface between the vapor and liquid phase. The characteristics of the interface depend on the type and geometry of the separation area: plates or package. The traditional methods of analysis for exchange processes use the concept 'theoretic plate', a physical entity for which the values of concentrations for vapors and liquid that leaves the plate are in ...

Energy Technology Data Exchange (ETDEWEB)

SiC has been considered as a primary candidate material for a first wall component in future fusion reactor because it has been claimed that SiC has excellent high-temperature properties, good chemical stability and low activation. However, the behavior of tritium on SiC has not been discussed yet. In this study, tritium trapping capacity on the surface of SiC was experimentally obtained at the temperature range of 25-800 deg. C in consideration of tritium trapping to the experimental system. The capacity, which was independent of the water vapor pressure in the gas phase and the temperature, was determined as about 10{sup 6} Bq/cm{sup 2}. The isotope exchange reaction rate between tritiated water in a gas phase and hydrogen on the surface was quantified at the temperature of 25, 500 and 700 deg. C in consideration of the behavior of tritium trapping at change of experimental condition by the numerical curve fitting method applying the serial ...

Science.gov (United States)

Least-squares analyses were performed on a set of atomic masses using standard and generalized senaiempirical mass laws. Presumably because of errors in the assured form of the standand mass law, its least-squares coefficients can be determined at best to an accuracy of about 10%, and masses are predicted with an uncertainty of several Mev/c/sup 2/. The standard mass law was generalized by addition of shell effect and deformation terms. While the least-squares fitting of the generalized mass law is better than for the standard mass law, it is still not possible to predict atomic masses to an accuracy better than a few Mev/c/sup 2/. The nuclear deformations and the well depth . of the nuclear interaction obtained from the additional mass-law terms are in reasonable agreement with more accurate determinations by other methods. A similar statement applies to the nuclear radius constant as obtained from the least-squares coefficient of the Coulomb energy ...

International Nuclear Information System (INIS)

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 ...

Energy Technology Data Exchange (ETDEWEB)

The Rb-Sr isotope systematics of bedrock, soil digests, and the cation exchange fraction of soils from a granitic glacial soil chronosequence in the Wind River Mountains, Wyoming, USA, were investigated. Six soil profiles ranging in age from 0.4 to {approximately}300 kyr were studied and revealed that the {sup 87}Sr/{sup 86}Sr ratio of exchangeable strontium in the B-horizons decreased from 0.7947 to 0.7114 with increasing soil age. Soil digests of the same samples showed much smaller variation in {sup 87}Sr/{sup 86}Sr from 0.7272 to 0.7103 and also generally decreased with increasing soil age. Elevation of the {sup 87}Sr/{sup 86}Sr ratios of Sr released by weathering over the soil digest and bedrock values results from the rapid weathering of biotite to form hydrobiotite and vermiculite in the younger soils. Biotite is estimated to weather at approximately eight times the rate of plagioclase (per gram of mineral) in the youngest soil profile ...

International Nuclear Information System (INIS)

... energy levels intermediate mass nuclei isotopes nuclei odd-even nuclei

Energy Technology Data Exchange (ETDEWEB)

Aimed at post-graduate and post-doctoral researchers in geochemistry, this book reflects the rapid changes in the applications of radioactive and stable isotope analysis to a range of geological and geochemical problems. Isotropic chemistry and methods used in mass spectroscopy are discussed initially. The second section deals with radiometric dating methods. The role of isotopes in climate and environmental research is also explored. The book closes with a section on extra-terrestrial matter, geothermometry and the isotopic geochemistry of the Earth`s lithosphere. (UK).

International Nuclear Information System (INIS)

... lifetime lutetium isotopes lutetium 171 lutetium 173 lutetium 175 lutetium 177

International Nuclear Information System (INIS)

The results of calculated and experimental investigation of interphase isotopic exchange efficiency in countercurrent columns are given when separation processes of isotope mixtures are taken place with use of liquid-solid systems. Effect of liquid phase flow on transfer unit height in ion exchange separation of boron, lithium, nitrogen isotopes is considered. 40 refs.; 5 figs.

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)

The radionuclide characteristics of light-water-reactor (LWR) spent fuel play key roles in the design and licensing activities for radioactive waste transportation systems, interim storage facilities, and the final repository site. Several areas of analysis require detailed information concerning the time-dependent behavior of radioactive nuclides including (1) neutron/gamma-ray sources for shielding studies, (2) fissile/absorber concentrations for criticality safety determinations, (3) residual decay heat predictions for thermal considerations, and (4) curie and/or radiological toxicity levels for materials assumed to be released into the ground/environment after long periods of time. The crucial nature of the radionuclide predictions over both short and long periods of time has resulted in an increased emphasis on thorough validation for radionuclide generation/depletion codes. Current radionuclide generation/depletion codes have the capability to follow the ...

Energy Technology Data Exchange (ETDEWEB)

Ordos Basin, the second largest sedimentary basin in China, contains enormous natural gas resources. Each of the four giant gas fields discovered so far in this basin (i.e., Sulige, Yulin, Wushenqi and Jingbian) has over 100 billion cubic meters (bcm) or 3.53 trillion cubic feet (tcf) of proven gas reserves. This study examines the stable carbon isotope data of 125 gas samples collected from the four giant gas fields in the Ordos Basin. Source rocks in the Upper Paleozoic coal measures are suggested by the generally high {delta}{sup 13}C values of C{sub 2}-C{sub 4} gaseous hydrocarbons in the gases from the Sulige, Yulin and Wushenqi gas fields. The {delta}{sup 13}C values of methane, benzene and toluene in gases from the Lower Paleozoic reservoirs of the Jingbian field indicate a significant contribution from humic source rocks, as they are similar to those in the Upper Paleozoic reservoirs of the Sulige, Yulin and Wushenqi gas fields. ...

International Nuclear Information System (INIS)

Nuclear material is either a product of technological processing of natural source material or it is entirely of anthropogenic origin. Consequently, nuclear material carries 'tool-marks' or 'fingerprints' of the process it was subjected to. Uranium fuels are examples of the first category, while plutonium belongs to the second category. The nature of these production processes is reflected in the elemental and isotopic composition of the material as well as in its microscopic and macroscopic appearance. All of these parameters can be determined using appropriate analytical techniques and they may result in important conclusions on the history and on the origin of the material. Therefore, they provide the most essential contribution to the prevention of future diversions of nuclear material from the same source. So far, essentially metallic impurities or light elements have been investigated for their potential in providing clues either on the type of process they ...

Energy Technology Data Exchange (ETDEWEB)

In a systematic survey of ternary fission induced by thermal neutrons at the Lohengrin spectrometer of the ILL/Grenoble, the target nucleus {sup 249}Cf has recently been added to the list of actinides under study. Special emphasis was put on the search for the heaviest ternary particles. At the limit of detection (some 10{sup -9} per fission), the heaviest isotopes observed for {sup 249}Cf(n{sub th},f) are {sup 37}Si and {sup 37}S. Another rare process in low energy fission is quaternary fission. Here two light charged particles accompany the main fragments. The reaction {sup 233} U(n,f) has been studied at a cold neutron beam of the ILL. Two processess have to be disentangled: simultaneous and sequential quaternary fission. In the simultaneous decay the most probable combination of particles is ({alpha} + {alpha}) with a yield of {approx}10{sup -7}/fission.

Energy Technology Data Exchange (ETDEWEB)

{sup 90}Sr, with a long half-life of 28.5 years, is the most dangerous strontium isotope. The adsorption behavior of radionuclides in the environment are closely related to the safe disposal of radioactive wastes. Since various types of minerals may exist in and around the repositories used for ultimate disposal of nuclear waste, the adsorption behavior of certain radionuclides onto and from these minerals and similar adsorbents should be studied in order to estimate the rates of transport of the nuclides in the event of water penetration into and through the repository. Information on the adsorption properties of the purified individual clay minerals may not be sufficient to predict the adsorption properties of a corresponding mixture, because these clay minerals may interact with each other and lead to modification of the adsorption properties of the mixture as compared to the pure minerals. The adsorption behavior of strontium on kaolinite ...

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 ...

Energy Technology Data Exchange (ETDEWEB)

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 mesurements. The experimental production cross-sections for the new nuclides and neighbouring isotopes are compared with an empirical parameterization. The resulting prospects for reaching even more neutron-rich isotopes, such as the doubly-magic nuclide {sup 78}Ni, are discussed. (orig.).

International Nuclear Information System (INIS)

We have measured production cross-sections of the new neutron-rich isotopes "5"8Ti, "6"1V, "6"3Cr, "6"6Mn, "6"9Fe, "7"1Co and neighbouring isotopes that have been identified as projectile fragments from reactions between a 500 MeV/u "8"6Kr 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 "7"8Ni, are discussed. (orig.).

Energy Technology Data Exchange (ETDEWEB)

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 ...

British Library Electronic Table of Contents (United Kingdom)

Selectivity control is a key issue in the zeolite facilitated conversion of methanol to hydrocarbons. This work addresses: (a) How the zeolite topology (MFI versus BEA) determines the type of intermediate participating in the catalytic cycle thereby controlling the ethene/propene product selectivity in the methanol to alkenes reaction, and (b) to what extent light alkene formation occurs via aromatic and alkene reaction intermediates for H-ZSM-5. Three catalyst samples have been studied in experiments relying on isotopic labeling. For H-beta, penta- and hexamethylbenzene are involved in an aromatics based hydrocarbon pool type mechanism leading predominantly to propene and the higher alkenes (a very low yield of ethene is observed), whereas for H-ZSM-5, the lower methylbenzenes are the aro...

International Nuclear Information System (INIS)

The properties of individual radioactive particles present in a sample, such as a swipe, are more interesting than bulk properties of the sample. The present work focuses on instrumentation that provides position-sensitive spectral information non-destructively from the sample. The experimental part of the work was realized using a device called PANDA (Particles And Non-Destructive Analysis). The detector setup used in the study contains a broad-energy HPGe gamma-ray detector and a position-sensitive alpha detector. Both detectors are connected to a time-stamping event-mode data acquisition system. The method is shown to locate particles with sub-millimetre accuracy and distinguish the interesting particles from non-interesting ones. (author)

CERN Document Server

We study a generalization of the Skyrme model with the inclusion of a sixth-order term and a generalized mass term. We first analyze the model in a regime where the nonlinear sigma and Skyrme terms are switched to zero which leads to well-behaved analytical BPS-type solutions. Adding contributions from the rotational energy, we reproduce the mass of the most abundant isotopes to rather good accuracy. These BPS-type solutions are then used to compute the contributions from the nonlinear sigma and Skyrme terms when these are switched on. We then adjust the four parameters of the model using two different procedures and find that the additional terms only represent small perturbations to the system. We finally calculate the binding energy per nucleon and compare our results with the experimental values.

Science.gov (United States)

The systematic behavior of excited nuclear levels was studied with Lu (Z = 71), Ta (Z = 73), and Re (Z = 75) activities produced in the ORNL proton cyclotron. Conversion-electron data are presented for electron-capture decay of Lu/sup 170.174m/, Ta/sup 173-178/, and Re/sup 179.181/. Level schemes are proposed based on these and on previously published up 173.175-179/, tulated. The proper ties of odd-A nuclei in the strongly deformed region of odd-N numbers 95-107 are discussed in connection with predictions of Mottelson and Nilsson. Two activities, Lu/sup 174m/ and Re/sup 179/ ( es sufficiert t 20 min), are previously unreported. (auth)

CERN Document Server

Particle accelerators are constructed and operated for a wide variety of applications. In particle physics - the branch of physics that studies the elementary constituents of matter and forces between them - high energy accelerators are used to look deep into the structure of matter. Medical particle accelerators are used for example in medicine to treat tumours [31], in imaging techniques such as Positron Emission Tomography (PET) [24], or for the radio-isotopes production. They also serve in many other industrial branches, e.g. geology, radiocarbon dating [39], molecular complex spectroscopy, lithography, food preservation etc. The eld of accelerator technology draws knowledge and expertise from a wide range of scientic disciplines and uses the latest technical knowledge. The incomplete list of covered disciplines includes mathematics, physics, electronics, computing, electromagnetic eld technology, microwave technology, cryogenics, vacuum ...

Energy Technology Data Exchange (ETDEWEB)

The distribution of /sup 35/S-sulfate and /sup 3/H-glucosamine in the angular region of the hamster was studied by light and electron microscopic autoradiography following intraperitoneal injection of these compounds to hamsters. Exposed silver grains of /sup 35/S-sulfate were concentrated in the trabecular meshwork, sclera, and cornea, and grains of /sup 3/H-glucosamine were localized in the trabecular region. The radioactivity of both isotopes was observed in the Golgi apparatuses of the endothelial cells of the angular aqueous plexus and the trabecular meshwork. The grains were noted over the entire cytoplasm, except for the nucleus, and then were incorporated into the amorphous substance and collagen fibers in the region adjacent to the angular aqueous sinus. These results suggest that endothelial cells in the angular region synthesize and secrete the sulfated glycosaminoglycans and hyaluronic acid.

International Nuclear Information System (INIS)

The talk will focus on spin-dependent competition between oblate and prolate shape minima in the potential energy landscape of "1"8"0Hf (the most neutron-rich stable isotope), mediated via the alignment of valence nucleons. Results of a prompt spectroscopic study, using deep inelastic reactions with Gammasphere and CHICO, bombarding a thin "2"3"2Th target with a "1"8"0Hf beam #approx#25% above the Coulomb barrier, will be presented. Nucleon alignments in both prolate and oblate minima will be discussed, as well as the favoring of oblate collective rotation at high spins, observed through a mixing with gamma vibrations built on the prolate shape.

British Library Electronic Table of Contents (United Kingdom)

The earthworm gut provides ideal in situ conditions for ingested heterotrophic soil bacteria capable of anaerobiosis. High amounts of mucus- and plant-derived saccharides such as glucose are abundant in the earthworm alimentary canal, and high concentrations of molecular hydrogen (H2) and organic acids in the alimentary canal are indicative of ongoing fermentations. Thus, the central objective of this study was to resolve potential links between fermentations and active fermenters in gut content of the anecic earthworm Lumbricus terrestris by 16S ribosomal RNA (rRNA)-based stable isotope probing, with [13C]glucose as a model substrate. Glucose consumption in anoxic gut content microcosms was rapid and yielded soluble organic compounds (acetate, butyrate, formate, lactate, propionate, succi...

Energy Technology Data Exchange (ETDEWEB)

The study of the {alpha}-particle energy distributions associated with ND and SD states in {sup 151,152}Dy has been carried out. The Dy isotopes were produced in the reaction {sup 37}Cl+{sup 123}Sb at 191 MeV via the ({alpha}5n) and ({alpha}4n) channels, respectively. In {sup 151}Dy the {alpha}-particle energy distributions associated to ND and SD are very different from each other, both at the low and high energy sides inducing a difference of 3 MeV in the {alpha}-particle mean energy. In {sup 152}Dy the situation is different; the {alpha}-particle spectral shapes are similar and a difference in the {alpha}-particle mean energy of only 0.7 MeV is deduced. A description in terms of energy localization of entry states is given. (orig.)

UK PubMed Central (United Kingdom)

Fatty acid biomarker analysis coupled with gas chromatography-isotope ratio mass spectrometry was used to confirm the presence of methanotrophic and thiotrophic bacterial endosymbionts in the tissues...Full Text Available

Science.gov (United States)

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

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

Energy Technology Data Exchange (ETDEWEB)

Element 97 was first produced in December 1949, by the bombardment of americium-241 with accelerated alpha particles. This new element was named berkelium (Bk) after Berkeley, California, the city of its discovery (Thompson, Ghiorso, and Seaborg, Phys. Rev. 77, 838 (1950); 80, 781 (1950)). In the 36 years since the discovery of Bk, a substantial amount of knowledge concerning the physicochemical properties of this relatively scarce transplutonium element has been acquired. All of the Bk isotopes of mass numbers 240 and 242 through 251 are presently known, but only berkelium-249 (..beta../sup -/ decay, 0.125 MeV, t/sub 1/2/ = 325 days) is available in sufficient quantities for bulk chemical studies. About 0.7 gram of this isotope has been isolated at the HFIR/TRU Complex in Oak Ridge, Tennessee in the last 18 years. Over the same time period, the scale of experimental work using berkelium-249 has increased from the tracer ...

International Nuclear Information System (INIS)

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

Energy Technology Data Exchange (ETDEWEB)

The isotopic enrichment of copper ions in a positive column Cu-Nu discharge using optogalvanic excitation is analyzed with a rate equation model With excitation at 510.6 nm, the fraction of the ions belonging to the 63-amu isotope of copper is enriched relative to the neutral abundance. Enrichment as large as 10% is calculated when the initial abundance of the neutral isotope is small (< or =0.1) and the discharge current density is large (> or =75 mA/cm/sup 2/). The degree of enrichment is examined as a function of the initial abundance, discharge current, the rate of charge exchange, and the diameter of the discharge tube.

International Nuclear Information System (INIS)

... radiations isotopes magnetic moments nuclear cascades nuclear properties

International Nuclear Information System (INIS)

Published in summary form only.

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.

International Nuclear Information System (INIS)

This work assesses the performance of a modified two-dimensional gamma scan system in spent fuel pin studies. The techniques for a two-dimensional gamma scan studied have been developed at the Hot Cell of Institute of Nuclear Energy Research (INER). Samples are acquired from the spent fuel pin, TPC-SP-C1, which was irradiated in a commercial reactor core (the first of its kind in Taiwan) for 2 years and then deposited in a cooling pool for 10 years. The spent fuel pin was then transferred into INER for further examination. The gamma scanning system was driven by a step motor which had an accuracy within 0.1 mm in both X-Y directions. Data obtained from this system are presented in both an isotopic distribution and contour plot. Results in this study closely correspond to those in other investigations, thereby confirming the effectiveness of this modified system. (author)

International Nuclear Information System (INIS)

The aim of this study was to assess the influence of the normal menstrual cycle and of menopause on the gastric emptying rate of solids. Gastric emptying was studied in 15 premenopausal and ten postmenopausal women with an isotopic technique after the ingestion of a radiolabelled test meal. Premenopausal women were studied twice: Within 1 week prior to menses and again 1 week after onset of menses. Postmenopausal women were studied only once. The emptying curves of the solid component of the meal fitted a linear model. The half-emptying time was 78#+-#5 min during the follicular phase, 75#+-#7 min during the luteal phase and 76#+-#6 min in postmenopausal women (differences not statistically significant). The mean percentages of the meal retained in the stomach at different time intervals were also similar in the three groups. These results suggest that the menstrual cycle does not ...

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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.).

Energy Technology Data Exchange (ETDEWEB)

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 ...

International Nuclear Information System (INIS)

An experimental study was performed in order to study the nuclear structure in odd--odd In isotopes. Low lying nuclear energy levels in "1"1"0In and "1"1"2In were determined from de-excitation #gamma#-rays produced with "1"0"7AG(#alpha#,n#gamma#)"1"1"0In, "1"0"8Pd("6Li,4n#gamma#)"1"1"0In, "1"0"9Ag(#alpha#,n#gamma#)"1"1"2In and "1"1"0Pd("6Li,4n#gamma#)"1"1"2In reactions. In addition, the "1"1"4In energy level structure was investigated with the "1"1"0Pd("7Li,3n#gamma#)"1"1"4In reaction. Properties of de-excitation #gamma#-rays were determined from #gamma#--#gamma# coincidence excitation and angular distribution measurements conducted with Ge(Li) and Ge(intr.) #gamma#-ray detectors. A sequence of intraconnected levels in each of "1"1"0 "1"1"2 "1"1"4In were assigned to the (#pi#"-"1/sub 9/2/, #nu#h/sub 11/2) configuration. For the "1"1"0 "1"1"2"1"1"4In energy level schemes a model calculation was performed using the ...

International Nuclear Information System (INIS)

Lithium Ceramics offer tremendous potential as a source for the production of tritium ("3H) for fusion power reactors. Their successful application will depend to a great extent upon the diffusion properties of the "6Li within the matrix. Consequently knowledge of "6Li concentration gradients in the ceramic matrices is an important requirement in the continued development of the technology. In this investigation, the neutron depth profile (NDP) technique has been applied to the study of concentration profiles of "6Li in lithium aluminate ceramics, doped with 1.8%, 50% and 95% "6Li isotopic concentrations. Specimen for analysis were prepared at Battelle (PNL) as pellet discs. Samples for diffusion studies were arranged as diffusion couples in the following manner: 1.8% "6Li discs/85% "6Li powder. Experiments were performed at the Texas A and M Nuclear Science Center Reactor Building, utilizing 1 MW equivalent thermal neutron ...

Energy Technology Data Exchange (ETDEWEB)

Understanding the link between the Sun and climate is vital in the current incidence of global climate change, and 10Be in natural archives constitutes an excellent tracer for this purpose. As cosmic rays enter the atmosphere, cosmogenic isotopes like 10Be and 14C are formed. Variations in solar activity modulate the amount of incoming cosmic rays, and thereby cosmogenic isotope production. Atmospherically produced 10Be enters natural archives such as sediments and glaciers by wet and dry deposition within about a year of production. 10Be from natural archives therefore provides information on past solar activity, and because these archives also contain climate information, solar activity and climate can be linked. One remaining question is to what degree 10Be in natural archives reflects production, and to what extent the local and regional environment overprints the production signal. To explore this, 10Be was measured at annual resolution ...

International Nuclear Information System (INIS)

The main objectives of this study was to determine the bone density for the purposes of i) determining the age of peak bone mass in each study group and ii) quantifying the differences in bone density as functions of age and sex. The results of estimating the age dependence of mineral density for the femoral neck, spine and total body of healthy women and men using DEXA are given. The age changes in concentrations of major minerals and electrolytes found for compact and trabecular bones of healthy male femoral neck with regard for the wet and dry tissue calculations are represented. Information about femoral neck water content depending on the age of healthy men is tabulated. The number of performed observations and analyses is evidently insufficient to make any final decision, however some preliminary conclusions can be drawn. In accordance with DEXA results, BMD maximum for the femoral neck, spine and total body of healthy women is found for ...

International Nuclear Information System (INIS)

Paper describes a new procedure to synthesize a pharmaceutical containing "2"1"1At. "2"1"1At"- anion was found to bind strongly with Rh"3"+ cation complexing with a thio-ether ligand - 1,5,9,13-tetratiacyclohexadecane-3,11-diol (16-S4-diol). One made use of "1"3"1I isotope to seek for the optimal conditions of the reaction. The derived complexes were studied by means of the paper electrophoresis, the ion exchange, the surface chromatography. One studied the kinetics of "1"3"1I"- anion binding with Rh(16-S4-diol), the dependence of the yield of "1"3"1I-Rh(16-S4-diol) forming complex on the temperature. the acidity of the reaction mixture and the concentration of the reagents. On the basis of the determined conditions of the synthesis one prepared "2"1"1At-Rh(16-S4-diol) complex by more astatide ("2"1"1At"-) to the equivalent amounts of RhCl_3 and tetra-thio-ether (16-S4-diol). One studied its behaviour

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The present review focuses on the isotropic composition in extra-terrestrial materials. There are many different factors in the variation in isotopic abundance between terrestrial and extra-terrestrial materials. Major factors in unusual isotopic composition are roughly grouped into three categories: factors associated with fractionation of isotopes, nuclear reaction or radioactive disintegration. Fractionation takes place due to differences in mass among various isotopes. There are physical and chemical factors. Physical ones include vaporization and condensation which meteorites may experience during their formation while the chemical ones include chemical reactions and chemical equilibration. There phenomena are mentioned as factors in the variation in isotopic ratio which is associated with nuclear reactions. An important nuclear reaction is the formation of elements that has ...

International Nuclear Information System (INIS)

The isotopic composition of Pd, Ag, Cd and Te has been measured by solid source mass spectrometry for four samples from reactor zones 2, 3-4, 5-6 and 7, and from four host rock samples external to the reactor zones from the Oklo mine site. The concentrations of these elements have also been determined in the eight samples using the stable isotope dilution technique. Cumulative fission yields have been derived from the reactor zone samples after correcting where necessary for the terrestrial component of the element concerned. It has been shown that fission-produced Pd and Te are retained almost in their entirety in the uraninite reactor zone samples, whereas a significant fraction of fission-produced Ag and Cd have migrated from the reactor zones. Fission product Cd is observed in the host rock samples, whereas no strong evidence of fission-produced Ag could be found. This the fission-produced Ag which has migrated from the reactor zones has ...

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Neutron reflectometry (NR) was used to measure the concentration profile of a symmetric PEP/dPEP polymer blend with nanometer-scale resolution in the one-phase region. The shape of the profile near the surface was found to differ significantly from mean-field theory predictions for all bulk concentrations and temperatures surveyed. The profile shape is flattened at the surface over a distance about half the bulk correlation length, a length scale far greater than that of the dispersive forces that are the dominant microscopic interaction in such blends. We introduce a new method for extracting the surface energy difference that drives segregation based on the Gibbs adsorption equation (GAE) and compare it to a previous method based on mean-field theory. While both methods produce qualitatively similar results (the surface energy of pure dPEP is {approx}0.21 mJ/m{sup 2} smaller than pure PEP), the GAE method is much less model dependent, requiring knowledge of only the free energy of ...

International Nuclear Information System (INIS)

Immobilization of long-lived fission products (LLFP) such as radioactive Tc, Cs and Sr into #alpha#-SiAlON ceramics was evaluated using stable isotopes instead of radioactive isotopes, and the applicability of #alpha#-SiAlON ceramics as the inert matrix for transmutation of LLFP was investigated. In the case of single addition of SrO, SrCO_3, Cs_2CO_3 or ReO_2 to the starting materials, #alpha#-SiAlON, single phase was not formed after hot-pressing. When Y_2O_3 was added with SrO, SrCO_3 or Cs_2CO_3 to the starting materials (#alpha#-Si_3N_4, AlN and #alpha#-Al_2O_3) in optimum compositions, #alpha#-SiAlON single phase was obtained after hot-pressing at 1700degC or 1800degC. From the EDS analysis, Sr and Y were detected from grains. It is suggested that Y would assist the expansion of interstices of #alpha#-SiAlON lattice, resulting in the incorporation of Sr"2"+ into #alpha#-SiAlON lattice. In the case of Cs addition with Y, Cs was not ...

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The feasibility was evaluated using MCNP-DSP, an analog Monte Carlo transport cod to simulate source-driven measurements. Models of an isolated Westinghouse 17x17 PWR fuel assembly in a 1500-ppM borated water storage pool were used. In the models, the fuel burnup profile was represented using seven axial burnup zones, each with isotopics estimated by the PDQ code. Four different fuel assemblies with average burnups from fresh to 32 GWd/MTU were modeled and analyzed. Analysis of the fuel assemblies was simulated by inducing fission in the fuel using a {sup 252}Cf source adjacent to the assembly and correlating source fissions with the response of a bank of {sup 3}He detectors adjacent to the assembly opposite the source. This analysis was performed at 7 different axial positions on each of the 4 assemblies, and the source-detector cross-spectrum signature was calculated for each of these 28 simulated measurements. The magnitude of the cross-spectrum signature ...

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Dawsonite, NaAlCO{sub 3}(OH){sub 2}, is widespread as a cement, replacement, and cavity filling in Permo-Triassic sedimentary rocks of the Bowen-Gunnedah-Sydney basin system eastern Australia. The origin of dawsonite in these rocks was studied by petrographic and stable isotope analysis. Dawsonite {delta}{sup 13}C (PDB) values range from {minus}4.0 to +4.1{per_thousand} and are remarkably consistent throughout the Bowen-Gunnedah-Sydney basin system. These values indicate either a marine carbonate or magmatic source for carbon in the dawsonite. A magmatic carbon source is considered more likely on the basis that (1) evidence of and the cause for widespread marine carbonate dissolution in the sedimentary successions are not apparent, (2) dawsonite is widespread in both marine and nonmarine facies, (3) the region has been the site of major igneous activity, (4) other dawsonite deposits of similar carbon isotopic composition ...

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The low excitation energy spectroscopy of /sup 86/Sr, /sup 88/Sr, /sup 89/Sr, /sup 86/Rb, and /sup 87/Rb nuclear systems was studied via one-nucleon transfer reactions. The strontium isotopes, /sup 87/Sr and /sup 88/Sr, were used as targets in this study. Spectroscopic strengths were extracted from the measured transfer reaction cross sections and the distorted wave Born approximation (DWBA) analysis. Efforts have been made to accomplish a complete detection of spectroscopic strengths through the excitation energy region where levels can be resolved and identified. A shell model sum rule analysis is then made. Diagonal matrix elements for the effective two-nucleon interaction were deduced from empirical energy centroid. Matrix elements normalized by their empirical monopole energy was plotted against the semiclassical angle between two spins. They were compared with various analytical function forms of the effective ...

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This work concerns the study of the nuclear superdeformation phenomenon in the rare earth region (A {approx} 150). The superdeformed (SD) states in Gadolinium and Dysprosium isotopes were produced via heavy-ion induced reactions and studied with the (EUROGAM EUROpean GAmma-ray Microscope) gamma multidetector array. Precise level attenuation method (DSAM). From the derived quadrupole moments, we find large differences in deformation between the yrast bands in neighbour nuclei explained in terms of the case of nuclei corresponding to an axis ratio of 2:1, the shell gaps are not fixed at a specific particle number and deformation. Furthermore the present results indicate that the deformations associated with identical bands are different supporting the picture that mass and deformation changes tend to compensate in SB bands with the same moments of inertia. (author). 114 refs.

International Nuclear Information System (INIS)

The main aims of the study were: 1) the evaluation of iron and zinc status in women of Lodz aged 18-45 years, 2) adaptation of the whole body counter to in vivo measurements absorption of iron given to the gastro-intestinal tract of volunteers and 3) in rat model estimation iron bioavailability from fortified wheat flour combined with products usually consumed in Poland. During five months investigations thirty seven women were examined each one twice in two months interval. Following variables were measured: iron and zinc in blood serum, in public and scalp hair and in food, taste acuity score, serum ferritin, hemoglobin, total iron binding capacity, red blood cells, mean corpuscular concentration and corpuscular volume. Prevalence of iron deficiency and iron deficient anemia were assessed by two models in terms of the depression of serum ferritin and hemoglobin concentrations. 64 refs, 6 figs, 23 tabs.

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)

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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... coriolis force de-excitation excited states half-life iridium 187 multipolarity

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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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... 171 lutetium 173 magnetic dipole moments nilsson-mottelson model nuclear

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Russian 1974. USSR Alekseev, VV Nemets, OF Stryuk, Yu.S. Tokarevskij,

Science.gov (United States)

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

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... organic compounds other organic compounds separation processes

International Nuclear Information System (INIS)

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

Energy Technology Data Exchange (ETDEWEB)

The large uranium fission cross section leading to iodine and the behaviour of this element in the cladding tube during energy production and afterwards during waste storage is a crucial problem, especially for {sup 129}I which is a very long half-life isotope (T=1.59 x 10{sup 7} yr). Since a combined external and internal oxidation of the zircaloy cladding tube occurs during the reactor processing, iodine diffusion parameters in zirconia are needed. In order to obtain these data, stable iodine atoms were first introduced by ion implantation into zirconia with an energy of 200 keV and a dose equal to 8 x 10{sup 15} at cm{sup -2}. Diffusion profiles were measured using 3 MeV alpha-particle Rutherford backscattering spectrometry at each step of the annealing procedure between 700 C and 900 C. In such experiments a reduced iodine concentration was observed, which correlated to a diffusion-like process. Similar analysis has been performed using radioactive {sup 131}I ...

International Nuclear Information System (INIS)

Iron is an essential micronutrient. As an integral part of hemoglobin, it is essential for the transport of oxygen in blood to the tissues. It is an important component of cytochromes and other tissue enzymes that are critical for cellular respiration and of myoglobin that helps maintain oxygen reserve in the muscle. It is also involved in the normal functioning of the immune function, and in the synthesis of steroid hormones and bile acids. There are serious functional consequences to iron deficiency and iron deficiency anemia (IDA) in the human body. The deleterious effects include increased morbidity, preterm delivery, low birth weight, delayed cognitive development, lowered cellular immunity and reduced physical work capacity. However, iron deficiency and IDA remain the world's most common deficiency disease in the 21st century. Recent estimates of people affected with iron deficiency and IDA are 3.5 billion. Iron deficiency anemia is most prevalent and severe in women and children ...

International Nuclear Information System (INIS)

The radioiodine-labeled amines currently available as brain-imaging agents, based on our previous work and that of others, are prepared either by exchange labeling or by direct iodination of a protected intermediate. The intrinsic slowness of these processes limits their potential for use with the positron-emitting 122I, as it has a half-life of only 3.6 min. This isotope has advantages of a low dose to the patient and availability from a generator containing the parent 20-h 122Xe. To develop a radiopharmaceutical in which 122I could be utilized, we prepared a number of secondary and tertiary amines (maintaining the 2,5-dimethoxy substitution pattern which allows direct iodination at the 4-position) with 131I. The organ distributions of these compounds were studied, and the best properties were found in the N,N-dimethyl homologue (2,5-dimethoxy-N,N-dimethyl-4-iodoamphetamine). This compound was successfully synthesized in a matter of seconds, ...

CERN Document Server

We consider the role of quantum effects in the transfer of hyrogen-like species in enzyme-catalysed reactions. This study is stimulated by claims that the observed magnitude and temperature dependence of kinetic isotope effects imply that quantum tunneling below the energy barrier associated with the transition state significantly enhances the reaction rate in many enzymes. We use a path integral approach which provides a general framework to understand tunneling in a quantum system which interacts with an environment at non-zero temperature. Here the quantum system is the active site of the enzyme and the environment is the surrounding protein and water. Tunneling well below the barrier only occurs for temperatures less than a temperature $T_0$ which is determined by the curvature of potential energy surface near the top of the barrier. We argue that for most enzymes this temperature is less than room temperature. For physically reasonable ...

International Nuclear Information System (INIS)

Calculations have been made to determine the production of "1"8"8W from "1"8"6W in several US fission reactor systems, e.g., Fast Flux Test Facility (FFTF), the High Flux Isotope Reactor (HFIR), and the Advanced Test Reactor (ATR). Important input to these calculations are the cross-section parameters for "1"8"6W, "1"8"7W, and "1"8"8W. Only two values have been measured for "1"8"7W and none for "1"8"8W. Consequently, results from integral measurements play a crucial role in determining the "1"8"7W and "1"8"8W values. This has been studied for irradiations in the FFTF and the Oregon State Univ. (OSU) research reactor. Short irradiation of enriched "1"8"6W in both the FFTF and the OSU reactors have produced #mu#Ci/g quantities of "1"8"8W/"1"8"8Re. Measurements were made of the "1"8"8W gamma ray emission. These results were incorporated with other available data to provide more accurate "1"8"8W calculations in fission reactor systems.

British Library Electronic Table of Contents (United Kingdom)

A tertiary structure of recombinant A22^G-B31^K-B32^R-human insulin monomer (insulin GKR) has been characterized by ^1H, ^1^3C NMR at natural isotopic abundance using NOESY, TOCSY, ^1H/^1^3C-GHSQC, and ^1H/^1^3C-GHSQC-TOCSY spectra. Translational diffusion studies indicate the monomer structure in water/acetonitrile (65/35vol.%). CSI analysis confirms existence of secondary structure motifs present in human insulin standard (HIS). Both techniques allow to establish that in this solvent recombinant insulin GKR exists as a monomer. Starting from structures calculated by the program CYANA, two different refinement protocols used molecular dynamics simulated annealing with the program AMBER; in vacuum (AMBER_VC), and including a generalized Born solvent model (AMBER_GB). From these calculation...

Energy Technology Data Exchange (ETDEWEB)

Iofetamine HCI {sup 123}I is the generic name for the hydrochloride salt of N-isopropyl-p-iodoamphetamine labeled with {sup 123}I, commonly called IMP. Iofetamine HCI {sup 123}I is prepared by isotopic exchange with [{sup 123}I]Nal and is formulated in isotonic aqueous NaCl solution containing 1 mCi/ml iofetamine HCI I 123, 0.15 mg/ml iofetamine HCI carrier, and phosphate buffer for pH control. The radiochemical purity is >97%, and the product is stable for more than 24 hours; the commercial product distributed today is prepared with high purity {sup 123}I with >98% radionuclidic purity. Two radioiodinated agents have seen significant clinical application for functional brain imaging: iofetamine HCI (IMP) (1) and N,N,N{prime}-trimethyl-N{prime}-(2-hydroxy-3-methyl-5-iodobenzyl)-1,3-propanediamine HIPDM (2). lofetamine HCI {sup 123}I is commercially available in the United States, Europe, and Japan. Although their primary use is for functional brain imaging, ...

International Nuclear Information System (INIS)

The PERMCAT process chosen for the final clean-up stage of the Tokamak Exhaust Processing system of the ITER tritium plant combines in a single component a catalytic reactor and a permeator using Pd/Ag membranes. This study covers the mechanical behaviour of a Pd/Ag membrane under different operating conditions. The consequences of hydrogen uptake by the membrane during nominal operation but also during off-normal events are presented. Depending on the operating conditions, expansions around 2% and significant deformations are observed. Different mechanical designs of PERMCAT reactors are then discussed. The first generation comprises finger-type membranes and two new mechanical designs use either additional edge welded bellows or a special corrugated Pd/Ag membrane. These upgraded designs improve the robustness and simplify the geometry of the component. The experimental validation of these new units has been carried out based on the measurements of the processing ...

International Nuclear Information System (INIS)

High-spin states of "1"8"7Ir have been populated in the "1"7"6Yb("1"5N,4n) reaction and measured with the YRAST Ball spectrometer. The #pi#h _9_/_2 rotational band has been extended beyond the first alignment crossing, which was found at rotational frequency (#Planck constant#/2#pi#)#omega# _c #approx =#0.39 MeV . Two different scenarios for describing this crossing are considered: the alignment of an h _9_/_2 proton or i _1_3_/_2 neutron pair and it is concluded that a proton band crossing is more likely. A systematic study of the rotational alignment crossings in the #pi#h _9_/_2 bands in the N=104,106,108 isotopes of _7_3Ta,_7_5Re,_7_7Ir, and _7_9Au is presented.

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The characterization data obtained to date are described for Approved Testing Material 104 (ATM-104), which is spent fuel from Assembly DO47 of the Calvert Cliffs Nuclear Power Plant (Unit 1), a pressurized-water reactor. This report is one in a series being prepared by the Materials Characterization Center at Pacific Northwest Laboratory (PNL) on spent fuel ATMs. The ATMs are receiving extensive examinations to provide a source of well-characterized spent fuel for testing in the US Department of Energy Office of Civilian Radioactive Waste Management (OCRWM) Program. ATM-104 consists of 128 full-length irradiated fuel rods with rod-average burnups of about 42 MWd/kgM and expected fission gas release of about 1%. A variety of analyses were performed to investigate cladding characteristics, radionuclide inventory, and redistribution of fission products. Characterization data include (1) fabricated fuel design, irradiation history, and subsequent storage and handling history; (2) ...

Science.gov (United States)

Metabolic carbon labelling experiments enable a large amount of extracellular fluxes and intracellular carbon isotope enrichments to be measured. Since the relation between the measured quantities and the unknown intracellular metabolic fluxes is given by bilinear balance equations, flux determination from this data set requires the numerical solution of a nonlinear inverse problem. To this end, a general algorithm for flux estimation from metabolic carbon labelling experiments based on the least squares approach is developed in this contribution and complemented by appropriate tools for statistical analysis. The linearization technique usually applied for the computation of nonlinear confidence regions is shown to be inappropriate in the case of large exchange fluxes. For this reason a sophisticated compactification transformation technique for nonlinear statistical analysis is developed. Statistical analysis is then performed by computing appropriate statistical ...

Energy Technology Data Exchange (ETDEWEB)

This thesis consists of an introduction and five included papers. Of these, four papers are published in international journals and the fifth was submitted for review in April 2000. Emphasis has been placed on both naturally and artificially generated light hydrocarbons in petroleum fluids and their proposed source rocks as well as direct application of light hydrocarbons to oil/source rock correlations. Collectively, these papers describe a strategy for interpreting the source of the light hydrocarbons in original oils and condensates as well as the source of the asphaltene fractions from the reservoir fluids. The influence of maturity on light hydrocarbon composition has also been evaluated. The papers include (1) compositional data on the light hydrocarbons from thermal extracts and kerogen pyrolysates of sediment samples, (2) light hydrocarbon data of oils and condensates as well as the pyrolysis products of the asphaltenes from these fluids, (3) assessment of compositional ...

Science.gov (United States)

The C isotopic composition of CH4 emissions are strongly influenced by the pathway of CH4 formation. Contrary to data from other freshwater systems, soil gas and surface flux measurements made in the tropical rain forests of Puerto Rico strongly suggest that CH4 produced in these environments was derived from CO2 reduction, rather than from acetate consumption. This study explored the effects of bacterial competition for acetate, pH, and soil structure on the pathways of CH4 formation in tropical rain forest soils. Our goal was to test two principal hypotheses: (1) ferric iron-reducing bacteria out-competed methanogens for acetate, resulting in greater CO2 reduction rather than aceticlastic methanogenesis, and (2) the low pH of tropical rain forest soils favors CO2 reduction rather than aceticlastic methanogenesis. In addition, this study also investigated the effect of destroying soil aggregate structure on the pathways ...

International Nuclear Information System (INIS)

The intensity of luminescence from the "2E state of Cr(bpy)_3"3"+ (bpy = 2, 2'-bipyridine) is lower in D_2O, although the "2E lifetime is unchanged, indicating that the "4T_2 (precursor to "2E) is sensitive to the isotopic nature of the solvent. A photophysical mechanism is proposed for Cr(NN)_3"3"+ complexes.

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).

Energy Technology Data Exchange (ETDEWEB)

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 ...

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Projectilelike fragments following the 80 MeV /sup 16/O+/sup 27/Al 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.

International Nuclear Information System (INIS)

A "9"2Mo beam with an energy of E/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 "7"8Y, "8"2Nb, "8"5Mo, "8"6Tc, and "8"9","9"0Ru.

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It is shown that observations of the lithium isotope ratio in high surface temperature Population II stars may be critical to cosmological nucleosynthesis models. In particular, decaying particle scenarios as derived in some supersymmetric models may stand or fall with such observations. 18 references.

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.

Energy Technology Data Exchange (ETDEWEB)

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.).

International Nuclear Information System (INIS)

The diagnostic accuracy is compared of the dual-isotope protocol and the conventional "2"0"1Tl protocol, for detection of the coronary artery disease (CAD) using data on a total of 69 patients after myocardial infarction (MI). The "2"0"1Tl protocol was used to examine 44 patients, the dual-isotope protocol was used with 25 patients. All patients were examined by coronarography; a narrowing of the artery by more than 50 % was considered significant for CAD. The sensitivity, specificity and diagnostic accuracy was 97.7 %, 100 % and 97.7 % resp. for the "2"0"1Tl protocol, and 95.2 %, 75 % and 92 % resp. for the dual-isotope protocol. A higher diagnostic accuracy of the dual-isotope protocol has not been proven, and the "2"0"1Tl protocol continues to be used for examinations of patients after MI

International Nuclear Information System (INIS)

Natural radioactive materials under certain conditions can reach hazardous radiological levels. The natural radionuclide ("2"3"8U, "2"3"2Th, "4"0K) contents of rock samples at various locations in the North Tushki area were investigated using gamma-spectrometric analysis. Estimates of the measured radionuclide content have been made for the absorbed dose rate of gamma radiation. The equivalent radium (R_e_q) and the external hazard index (H_e_x) which resulted from the natural radionuclides in soil are also calculated and tabulated. The studied samples have been collected from various rock exposures in the North Tushki area. The distribution of major oxides, U and Th were studied. It is found that the enrichment and depletion of the major oxides are mainly due to the effect of hydrothermal alteration, which caused mobility of some major oxides, which increases some elements and decreases others. It is important to mention that the ...

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Thallium-201 myocardial imaging was performed in 80 children with coronary arterial lesions due to Kawasaki disease in order to assess the value of serial and exercise myocardial imagings. In eight of these children, abnormalities of the image were noted. Twenty children had serial thallium studies with an interval of three to 18 months, and five of these showed changes in the image including appearance of a new perfusion defect in one patient and improvement of perfusion defects in four. These changes of the myocardial image were correlated well with coronary angiographic findings obtained within a few days of the isotope studies. It was noted that the changes of the myocardial image were more frequently observed at relatively recent period recovered from Kawasaki disease. Exercise myocardial imaging using a bicycle ergometer was performed in eight children with coronary arterial lesions. In three an evidence of ...

Energy Technology Data Exchange (ETDEWEB)

A geological study was conducted to better understand the nature of cleat development and degree of mineralization in coal seams of the Scollard and Coalspur Formations in western Alberta. The results can be applied to equivalent formations. The source and reservoir rocks of a coalbed methane (CBM) system were described. Coal seams are basically fractured reservoirs with 7 types of cleats. The field work involved cleat minerals sampling and determining cleat attributes such as type, strike and spacing from open-cut mines and outcrops. The laboratory work involved X-Ray diffraction, scanning electron microscopy, energy dispersive microscopy, stable isotope analysis, and fluid inclusions analysis. The study showed that coal seams of the Scollard and Coalspur Formations are widespread and cleated to various degrees. The face and butt cleats strike northeast-southwest and northwest southeast respectively along the structural ...

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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 ...

Energy Technology Data Exchange (ETDEWEB)

Elastic and inelastic proton scattering has been measured in inverse kinematics on the unstable nucleus {sup 40}S. A phenomenological DWBA analysis yields a quadrupole deformation parameter {beta}{sub 2} = 0.35 {+-} 0.05 for the 2{sup +}{sub 1} state. Consistent phenomenological and microscopic proton scattering analyses have been applied to all even-even Sulfur isotopes from A = 32 to A = 40. The microscopic analysis used microscopic collective model densities and a modified Jeukenne-Lejeune-Mahaux effective interaction. This analysis suggests the presence of a neutron skin in the heavy sulfur isotopes. The analysis is consistent with normalization values for {lambda}{sub {upsilon}} and {lambda}{sub {omega}} of 0.95 for both the real and imaginary parts of the JLM potential. (author)

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. ...

International Nuclear Information System (INIS)

It has been reported by the present authors that behavior of tritium release from solid breeder grain is consisted of diffusion in grain, tritium transfer at surface layer and surface reactions on grain surface such as adsorption or isotope exchange reactions. Tritium release curves estimated using the tritium release model gave good agreement with observed tritium release curves from Li_4SiO_4, Li_2ZrO_3 or LiAlO_2. Tritium release behavior from Li_2TiO_3 under humid purge gas, dry purge gas and dry purge gas with hydrogen conditions is discussed in this study, tritium release curves using the release model that we proposed previously give a good agreements with experimental tritium release curves. Tritium effective diffusivity in the crystal grain of Li_2TiO_3 is also estimated in this study using a curve-fitting method applied to the release curves obtained under the humid purge gas condition. It is discussed that change ...

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This report describes progress made during the extended final year (April 1, 1992 to December 31, 1993) and summarizes the accomplishments of the entire three-year period (April 1, 1990 through December 31, 1993) of the current US Department of Energy grant DE-FG06-87ER40345. This work is carried out primarily at the UNISOR (University Isotope Separator at Oak Ridge) facility of the Holifield Heavy-Ion Research Facility of the Oak Ridge National Laboratory. The primary mission of this work is the study of the structure and properties of nuclei far from stability through on-line nuclear orientation using the UNISOR Nuclear Orientation Facility, a helium dilution refrigerator coupled on-line to the UNISOR mass separator. The author`s group was one of the original proposers of this facility and played a central role in its design, construction, and development. The structure of nuclei far from stability is in general poorly known. Knowledge from ...

Science.gov (United States)

Thesis. Five-particle shell-model calculations, using a spin-dependent potential, were performed for the nucleus /sup 101/Tc. The effects of varying the single-particle energy differences and the strengths of the spin-dependent and pairing terms are discussed. The isobars /sup 101/Mo and /sup 101/Tc were chemically separated to enable the detailed study of their decay schemes. As a result, 184 gamma rays were observed in the decay of /sup 101/Mo, and 169 of them were assigned to 45 levels in /sup 101/Tc. In the decay of /sup 101/Tc, 27 gamma rays were observed, and 26 of them were assigned to 11 levels in /sup 101/Ru. In a study of the decays of /sup 142/Xe and /sup 142/Cs the TRI STAN on-line isotope separator was used to separate the 142 mass chain produced in /sup 235/U fission with /sup 142/2Xe as the emanating and accelerated nuclide. Isobaric separation of /sup 142/Xe and /sup 142/Cs ...

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)

Using nitrogen-13 initial measurements have been made of rumen ammonia-nitrogen pool size and turnover, and rate of incorporation of ammonia into microbial protein. It is also feasible to measure the rate of incorporation of absorbed ammonia into urea and the appearance of label in saliva.

UK PubMed Central (United Kingdom)

A fast and sensitive LC-ESI-MS method is described for the comparative quantification of 16 estrogen metabolites based on the derivatization of estrogens with a novel derivatizing reagent, N-methyl-nicotinic...Full Text Available

UK PubMed Central (United Kingdom)

In vivo short-term effects of recombinant human TNF-alpha on lipolysis, FFA flux, fat oxidation, triglyceride-fatty acid cycling, and glucose kinetics were evaluated with stable isotopic tracers and...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Optical Isotope shift measurements have been performed for the {sup 240f,242f}Am fission isomers to test the stability of nuclear deformation as function of the neutron number. The method is based on resonance ionization spectroscopy (RIS) in a buffer gas cell with fission detection of the ionization process. The {sup 240f,242f}Am fission isomers have been produced by {sup 242}Pu(p, 3n), {sup 242}Pu(d, 2n) reactions, respectively. Relative isotope shift ratios X{sub exp}{sup 242f}(500 nm)=IS{sup 242f,241}/IS{sup 243,241}=41.4(8) and X{sub exp}{sup 240f}(500 nm)=IS{sup 240f,241}/IS{sup 243,241}=39.2(8) were measured. From these ratios a small difference {delta}{beta}{sub 2}{sup 242f,240f}=0.0076(14) of the deformation parameter {beta}{sub 2} can be deduced assuming that the isotope shift between the reference isotopes {sup 241,243}Am is caused by a pure volume change. (orig.)

Energy Technology Data Exchange (ETDEWEB)

Uranium enrichment by gas centrifugation relies on the pressure diffusion of the isotopes when their gaseous mixture is submitted to the pressure diffusion in the strong radial pressure gradient due to the centrifugal force in a very rapidly rotating cylinder. To compute the isotope separation in a gas centrifuge, the viscous compressible Navier-Stokes equations are solved for the mixture, then the diffusion equations are solved for the isotopes. As far as the separation performance is concerned, the models deal with the steady state of the axi-symmetric gas motion in the rotating cylinder. The numerical tools are briefly presented: first, the MOLINA code which numerically solves the axi-symmetric gas motion in the specific conditions of rapid rotation by use of a change of variables suited to the high density gradient and by use of a Marker And Cell method; then, the diffusion equations solver which uses a Finite Volume ...

International Nuclear Information System (INIS)

In the presence of hydroxyl anion, both formaldehyde and glyoxal are known to undergo rearrangements involving intermolecular and intramolecular hydride transfer (the Cannizzaro and Benzilic acid rearrangements respectively). The authors report ab initio SCF-MO calculations of the transition state geometries, the activation barriers, and the hydrogen isotope effects for these two reactions. The structure of the transition state for the rection involving formaldehyde is usually basis set dependent, becoming more linear and symmetrical as the basis set size increases. In contrast, the analogous transition state for the glyoxal reaction involves a highly non-linear hydride transfer. They find the isotope effects to be quite low for the Cannizzaro reaction, and significantly larger for the non-linear benzilic acid rection, in apparent contradiction to Westheimer's suggestion the isotope effects reach a maximum for linear ...

UK PubMed Central (United Kingdom)

We describe a non-isotopic, semi-automated method for large-scale multiplex analysis of nucleic acid sequences, using the cystic fibrosis transmembrane regulator (CFTR) gene as an example. Products...Full Text Available

Science.gov (United States)

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

Energy Technology Data Exchange (ETDEWEB)

A new method for the determination of {sup 237}Np and Pu isotopes in large soil samples has been developed that provides enhanced uranium removal to facilitate assay by inductively coupled plasma mass spectrometry (ICP-MS). This method allows rapid preconcentration and separation of plutonium and neptunium in large soil samples for the measurement of {sup 237}Np and Pu isotopes by ICP-MS. {sup 238}U can interfere with {sup 239}Pu measurement by ICP-MS as {sup 238}UH{sup +} mass overlap and {sup 237}Np via {sup 238}U peak tailing. The method provides enhanced removal of uranium by separating Pu and Np initially on TEVA Resin, then transferring Pu to DGA resin for additional purification. The decontamination factor for removal of uranium from plutonium for this method is greater than 1 x 10{sup 6}. Alpha spectrometry can also be applied so that the shorter-lived {sup 238}Pu isotope can be measured successfully. {sup 239}Pu, ...

Energy Technology Data Exchange (ETDEWEB)

A stable isotope mass-balance of dissolved inorganic carbon during a blue-green algae bloom in a softwater lake demonstrates that at low partial pressure of carbon dioxide there must be a large net negative carbon isotope fractionation between atmospheric CO/sub 2/ and the CO/sub 2/ absorbed by lake water at pH = 9.5. Chemical enhancement of CO/sub 2/ invasion at high pH by the reaction CO/sub 2/ + OH/sup -/ ..-->.. HCO/sub 3//sup -/ at large apparent film thicknesses may result in carbon isotope fractionation approaching that for a hydroxide solution. This phenomenon, coupled with a decrease in the photosynthetic fractionation, forced the surface water of a softwater lake to achieve increasingly negative delta /sup 13/C values during an algal bloom, which is in the opposite sense to the trend that results from photosynthesis under less extreme conditions. This and other similar systems must operate under non-equilibrium ...