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1

Acetylation and glycation of fibrinogen in vitro occur at specific lysine residues in a concentration dependent manner: A mass spectrometric and isotope labeling study  

SciTech Connect (OSTI)

Highlights: Black-Right-Pointing-Pointer Fibrinogen was incubated in vitro with glucose or aspirin. Black-Right-Pointing-Pointer Acetylations and glycations were found at twelve lysine sites by mass spectrometry. Black-Right-Pointing-Pointer The labeling by aspirin and glucose occurred dose-dependently. Black-Right-Pointing-Pointer No competition between glucose and aspirin for binding to fibrinogen was found. -- Abstract: Aspirin may exert part of its antithrombotic effects through platelet-independent mechanisms. Diabetes is a condition in which the beneficial effects of aspirin are less prominent or absent - a phenomenon called 'aspirin resistance'. We investigated whether acetylation and glycation occur at specific sites in fibrinogen and if competition between glucose and aspirin in binding to fibrinogen occurs. Our hypothesis was that such competition might be one explanation to 'aspirin resistance' in diabetes. After incubation of fibrinogen in vitro with aspirin (0.8 mM, 24 h) or glucose (100 mM, 5-10 days), we found 12 modified sites with mass spectrometric techniques. Acetylations in the {alpha}-chain: {alpha}K191, {alpha}K208, {alpha}K224, {alpha}K429, {alpha}K457, {alpha}K539, {alpha}K562, in the {beta}-chain: {beta}K233, and in the {gamma}-chain: {gamma}K170 and {gamma}K273. Glycations were found at {beta}K133 and {gamma}K75, alternatively {gamma}K85. Notably, the lysine 539 is a site involved in FXIII-mediated cross-linking of fibrin. With isotope labeling in vitro, using [{sup 14}C-acetyl]salicylic acid and [{sup 14}C]glucose, a labeling of 0.013-0.084 and 0.12-0.5 mol of acetylated and glycated adduct/mol fibrinogen, respectively, was found for clinically (12.9-100 {mu}M aspirin) and physiologically (2-8 mM glucose) relevant plasma concentrations. No competition between acetylation and glycation could be demonstrated. Thus, fibrinogen is acetylated at several lysine residues, some of which are involved in the cross-linking of fibrinogen. This may mechanistically explain why aspirin facilitates fibrin degradation. We find no support for the idea that glycation of fibrin(ogen) interferes with acetylation of fibrinogen.

Svensson, Jan, E-mail: jan.svensson@ki.se [Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital (Solna), SE-171 76 Stockholm (Sweden) [Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital (Solna), SE-171 76 Stockholm (Sweden); Karolinska Institutet, Department of Clinical Sciences, Danderyd Hospital, SE-182 88 Stockholm (Sweden); Bergman, Ann-Charlotte [Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital (Solna), SE-171 76 Stockholm (Sweden)] [Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital (Solna), SE-171 76 Stockholm (Sweden); Adamson, Ulf [Karolinska Institutet, Department of Clinical Sciences, Danderyd Hospital, SE-182 88 Stockholm (Sweden)] [Karolinska Institutet, Department of Clinical Sciences, Danderyd Hospital, SE-182 88 Stockholm (Sweden); Blombaeck, Margareta [Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital (Solna), SE-171 76 Stockholm (Sweden)] [Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital (Solna), SE-171 76 Stockholm (Sweden); Wallen, Hakan; Joerneskog, Gun [Karolinska Institutet, Department of Clinical Sciences, Danderyd Hospital, SE-182 88 Stockholm (Sweden)] [Karolinska Institutet, Department of Clinical Sciences, Danderyd Hospital, SE-182 88 Stockholm (Sweden)

2012-05-04T23:59:59.000Z

2

Existence of long-lived isomeric states in naturally-occurring neutron-deficient Th isotopes  

SciTech Connect (OSTI)

Four long-lived neutron-deficient Th isotopes with atomic mass numbers 211 to 218 and abundances of (1-10)x10{sup -11} relative to {sup 232}Th have been found in a study of naturally-occurring Th using inductively coupled plasma-sector field mass spectrometry. It is deduced that long-lived isomeric states exist in these isotopes. The hypothesis that they might belong to a new class of long-lived high spin super- and hyperdeformed isomeric states is discussed.

Marinov, A.; Kashiv, Y. [Racah Institute of Physics, Hebrew University of Jerusalem, Jerusalem 91904 (Israel); Rodushkin, I. [Analytica AB, Aurorum 10, S-977 75 Luleaa (Sweden); Halicz, L.; Segal, I. [Geological Survey of Israel, 30 Malkhei Israel St., Jerusalem 95501 (Israel); Pape, A. [IPHC-UMR7178, IN2P3-CNRS/ULP, BP 28, F-67037 Strasbourg cedex 2 (France); Gentry, R. V. [Earth Science Associates, P.O. Box 12067, Knoxville, Tennessee 37912-0067 (United States); Miller, H. W. [P. O. Box 1092, Boulder, Colorado 80306-1092 (United States); Kolb, D. [Department of Physics, University GH Kassel, D-34109 Kassel (Germany); Brandt, R. [Kernchemie, Philipps University, D-35041 Marburg (Germany)

2007-08-15T23:59:59.000Z

3

Advanced Mass Spectrometers for Hydrogen Isotope Analyses  

SciTech Connect (OSTI)

This report is a summary of the results of a joint Savannah River Laboratory (SRL) - Savannah River Plant (SRP) ''Hydrogen Isotope Mass Spectrometer Evaluation Program''. The program was undertaken to evaluate two prototype hydrogen isotope mass spectrometers and obtain sufficient data to permit SRP personnel to specify the mass spectrometers to replace obsolete instruments.

Chastagner, P.

2001-08-01T23:59:59.000Z

4

Comment on 'Existence of long-lived isomeric states in naturally-occurring neutron-deficient Th isotopes'  

SciTech Connect (OSTI)

In their article ''Existence of Long-Lived Isomeric States in Naturally-Occuring Neutron-Deficient Th Isotopes''[Phys. Rev. C 76, 021303 (2007)], Marinov et al. fail to demonstrate that basic mass spectrometric protocols, such as abundance sensitivity, linearity, and freedom from possible interferences, have been met. In particular, the claim that four isomeric states of Th have been discovered, using an inductively coupled plasma-sector field mass spectrometer (ICP-SFMS), with abundances from (1-10)x10{sup -11} relative to {sup 232}Th, cannot be accepted, given the known abundance sensitivities of other sector field mass spectrometers. Accelerator mass spectrometry is the only mass spectrometric methodology capable of measuring relative abundances of the magnitude claimed by Marinov et al.

Barber, R. C.; De Laeter, J. R. [Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba R3T 2N2 (Canada); Department of Applied Physics, Curtin University, Perth, Western Australia (Australia)

2009-04-15T23:59:59.000Z

5

Compact hydrogen/helium isotope mass spectrometer  

DOE Patents [OSTI]

The compact hydrogen and helium isotope mass spectrometer of the present invention combines low mass-resolution ion mass spectrometry and beam-foil interaction technology to unambiguously detect and quantify deuterium (D), tritium (T), hydrogen molecule (H.sub.2, HD, D.sub.2, HT, DT, and T.sub.2), .sup.3 He, and .sup.4 He concentrations and concentration variations. The spectrometer provides real-time, high sensitivity, and high accuracy measurements. Currently, no fieldable D or molecular speciation detectors exist. Furthermore, the present spectrometer has a significant advantage over traditional T detectors: no confusion of the measurements by other beta-emitters, and complete separation of atomic and molecular species of equivalent atomic mass (e.g., HD and .sup.3 He).

Funsten, Herbert O. (Los Alamos, NM); McComas, David J. (Los Alamos, NM); Scime, Earl E. (Morgantown, WV)

1996-01-01T23:59:59.000Z

6

Isotopic mass-dependence of noble gas diffusion coefficients inwater  

SciTech Connect (OSTI)

Noble gas isotopes are used extensively as tracers inhydrologic and paleoclimatic studies. These applications requireknowledge of the isotopic mass (m) dependence of noble gas diffusioncoefficients in water (D), which has not been measured but is estimatedusing experimental D-values for the major isotopes along with an untestedrelationship from kinetic theory, D prop m-0.5. We applied moleculardynamics methods to determine the mass dependence of D for four noblegases at 298 K, finding that D prop m-beta with beta<0.2, whichrefutes the kinetic theory model underlying all currentapplications.

Bourg, I.C.; Sposito, G.

2007-06-25T23:59:59.000Z

7

Elemental and isotopic analysis of inorganic salts by laser desorption ionization mass spectrometry  

SciTech Connect (OSTI)

Laser desorption ionization mass spectrometry is applied for the analysis of elements as well as their isotopic composition in different inorganic salts. At very low laser energies the inorganic ions are desorbed and ionized from the thin layer of the sample surface. The naturally occurring isotopes of alkali and silver ions are resolved using time of flight mass spectrometer. Further increase in laser energy shows the appearance of Al, Cr, and Fe ions in the mass spectra. This indicates the penetration laser beam beyond the sample surface leading to the ablation of sample target at higher energies. The simultaneous appearance of atomic ions from the sample target at relatively higher laser energies hampers the unambiguous identification of amino acid residues from the biomolecular ions in MALDI-MS.

Jayasekharan, T.; Sahoo, N. K. [Applied Spectroscopy Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)

2013-02-05T23:59:59.000Z

8

Ra, a naturally occurring isotope of the 238 U-series with a  

E-Print Network [OSTI]

for counting, liquid scintillation, or mass spectrometry at comparable activities, the simple setup, low cost- fiber and is continuously transferred to a scintillation cham- 226 Ra determination via the rate of 222

Paris-Sud XI, Université de

9

Mass-dependent and -independent fractionation of isotopes in Ni and Pb chelate complex formation reactions  

SciTech Connect (OSTI)

Mass independent fractionation (MIF) has been a very interesting topic in the field of inorganic isotope chemistry, in particular, geo- and cosmo- chemistry. In the present work, we studied the isotope fractionation of Ni(II) and Pb(II) ions in complex formation with chelating reagent EDTA. To obtain clear results on the mass dependence of the isotope fractionation, we have conducted long-distance ion exchange chromatography of Ni(II) and Pb(II), using chelate complex reagent EDTA. The results apparently show that the isotope fractionation in Ni complex formation system is governed by the mass dependent rule. On the other hand the isotope fractionation in the Pb complex system is governed by the mass independent rule or the nuclear volume effect.

Nomura, Masao; Kudo, Takashi; Adachi, Atsuhiko; Aida, Masao; Fujii, Yasuhiko [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, O-okayama Meguroku, Tokyo, 152-8550 (Japan)] [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, O-okayama Meguroku, Tokyo, 152-8550 (Japan)

2013-11-13T23:59:59.000Z

10

Isotopically selective, Doppler-free, saturation spectroscopy of lutetium isotopes via resonance ionization mass spectrometry  

SciTech Connect (OSTI)

A new technique utilizing RIMS to obtain very high resolution atomic spectra with isotopic selectivity has been demonstrated. This technique allows the precise determination of HF splitting constants, limited only by the transition's natural linewidth. In addition, it is also feasible with this technique to accurately determine atomic isotope shifts. The exact determination of HF component line positions provides data for isotopically selective ionization which, in turn, will increase RIMS' dynamic range. Future work includes the incorporation of a /open quotes/vibrating/close quotes/ mirror and the study of rarer isotopes, i.e., /sup 174/Lu, /sup 173/Lu, /sup 172/Lu, /sup 171/Lu, and possibly, /sup 170/Lu. 13 refs., 3 figs.

Fearey, B.L.; Parent, D.C.; Keller, R.A.; Miller, C.M.

1988-01-01T23:59:59.000Z

11

Prospects for large dynamic range isotope analysis using photon burst mass spectrometry  

SciTech Connect (OSTI)

Photon Burst Mass Spectrometry is a relatively new and untried method which may complement and extend the impressive achievements of Resonance Ionization Mass Spectrometry and Accelerator Mass Spectrometry in the field of large dynamic range isotope analysis. Theoretical predictions indicate that measurements in the 10/sup /minus/11/ to 10/sup /minus/15/ range are possible in a reasonable period of time with zero background. Experimentally only the very first demonstrations of PBMS with stable isotopes have been completed. 8 refs., 1 fig., 1 tab.

Fairbank, W.M. Jr.; LaBelle, R.D.; Keller, R.A.; Miller, C.M.; Poths, J.; Fearey, B.L.

1988-01-01T23:59:59.000Z

12

E-Print Network 3.0 - argon isotopes Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

one of the earliest isotope... this is not always the case--see later). The naturally occurring isotopes of argon are measured by mass spectrometry... isotopes but also small...

13

E-Print Network 3.0 - argon isotopic chains Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

one of the earliest isotope... this is not always the case--see later). The naturally occurring isotopes of argon are measured by mass spectrometry... isotopes but also small...

14

O isotopic composition of CaCO3 measured by continuous ow isotope ratio mass spectrometry  

E-Print Network [OSTI]

for the stable isotopes of carbon-13 and oxygen-18 to determine the ratios of the rare (usually the heavy The reaction of acid with calcite produces solid calcium hydrogen phosphate, liquid water, and two gases, water then are exposed to a dry- ice slush, and the carbon dioxide sublimates while the water stays frozen. After two

15

Very high resolution saturation spectroscopy of lutetium isotopes via c-w single-frequency laser resonance ionization mass spectrometry  

SciTech Connect (OSTI)

In this paper, we discuss the use of Resonance Ionization Mass Spectrometry (RIMS) to perform isotopically selective saturation spectroscopy of lutetium isotopes. Utilizing this technique, it is shown that accurate measurements of the relative frequencies of hyperfine (HF) components for different isotopes easily can be made without the need for an isotopically enriched sample. The precision with which the HF splitting constants can be determined is estimated to be approx.5 times greater than in previous work.

Fearey, B.L.; Parent, D.C.; Keller, R.A.; Miller, C.M.

1987-01-01T23:59:59.000Z

16

The mid-Cretaceous water bearer: isotope mass balance quantication of the Albian hydrologic cycle  

E-Print Network [OSTI]

. Witzke a;b;c a Department of Geoscience, University of Iowa, Iowa City, IA 52242-1379, USA b Center of the equable `greenhouse' Albian Stage in the KWIB. The mass balance model tracks the evolving isotopic conditions. Ã? 2002 Elsevier Science B.V. All rights reserved. Keywords: sphaerosiderites; Cretaceous; oxygen

González, Luis A.

17

Separation Of Uranium And Plutonium Isotopes For Measurement By Multi Collector Inductively Coupled Plasma Mass Spectroscopy  

SciTech Connect (OSTI)

Uranium (U) and plutonium (Pu) isotopes in coral soils, contaminated by nuclear weapons testing in the northern Marshall Islands, were isolated by ion-exchange chromatography and analyzed by mass spectrometry. The soil samples were spiked with {sup 233}U and {sup 242}Pu tracers, dissolved in minerals acids, and U and Pu isotopes isolated and purified on commercially available ion-exchange columns. The ion-exchange technique employed a TEVA{reg_sign} column coupled to a UTEVA{reg_sign} column. U and Pu isotope fractions were then further isolated using separate elution schemes, and the purified fractions containing U and Pu isotopes analyzed sequentially using multi-collector inductively coupled plasma mass spectrometer (MCICP-MS). High precision measurements of {sup 234}U/{sup 235}U, {sup 238}U/{sup 235}U, {sup 236}U/{sup 235}U, and {sup 240}Pu/{sup 239}Pu in soil samples were attained using the described methodology and instrumentation, and provide a basis for conducting more detailed assessments of the behavior and transfer of uranium and plutonium in the environment.

Martinelli, R E; Hamilton, T F; Williams, R W; Kehl, S R

2009-03-29T23:59:59.000Z

18

Mass-related inversion symmetry breaking and phonon self-energy renormalization in isotopically labeled AB-stacked bilayer graphene  

E-Print Network [OSTI]

A mass-related symmetry breaking in isotopically labeled bilayer graphene (2LG) was investigated during in-situ electrochemical charging of AB stacked (AB-2LG) and turbostratic (t-2LG) layers. The overlap of the two ...

Araujo, Paulo Antonio Trinidade

19

THE GENESIS SOLAR WIND CONCENTRATOR TARGET: MASS FRACTIONATION CHARACTERISED BY NE ISOTOPES  

SciTech Connect (OSTI)

The concentrator on Genesis provides samples of increased fluences of solar wind ions for precise determination of the oxygen isotopic composition of the solar wind. The concentration process caused mass fractionation as function of the radial target position. They measured the fractionation using Ne released by UV laser ablation along two arms of the gold cross from the concentrator target to compare measured Ne with modeled Ne. The latter is based on simulations using actual conditions of the solar wind during Genesis operation. Measured Ne abundances and isotopic composition of both arms agree within uncertainties indicating a radial symmetric concentration process. Ne data reveal a maximum concentration factor of {approx} 30% at the target center and a target-wide fractionation of Ne isotopes of 3.8%/amu with monotonously decreasing {sup 20}Ne/{sup 22}Ne ratios towards the center. The experimentally determined data, in particular the isotopic fractionation, differ from the modeled data. They discuss potential reasons and propose future attempts to overcome these disagreements.

WIENS, ROGER C. [Los Alamos National Laboratory; OLINGER, C. [Los Alamos National Laboratory; HEBER, V.S. [Los Alamos National Laboratory; REISENFELD, D.B. [Los Alamos National Laboratory; BURNETT, D.S. [Los Alamos National Laboratory; ALLTON, J.H. [Los Alamos National Laboratory; BAUR, H. [Los Alamos National Laboratory; WIECHERT, U. [Los Alamos National Laboratory; WIELER, R. [Los Alamos National Laboratory

2007-01-02T23:59:59.000Z

20

Analytical Validation of Accelerator Mass Spectrometry for Pharmaceutical Development: the Measurement of Carbon-14 Isotope Ratio.  

SciTech Connect (OSTI)

Accelerator mass spectrometry (AMS) is an isotope based measurement technology that utilizes carbon-14 labeled compounds in the pharmaceutical development process to measure compounds at very low concentrations, empowers microdosing as an investigational tool, and extends the utility of {sup 14}C labeled compounds to dramatically lower levels. It is a form of isotope ratio mass spectrometry that can provide either measurements of total compound equivalents or, when coupled to separation technology such as chromatography, quantitation of specific compounds. The properties of AMS as a measurement technique are investigated here, and the parameters of method validation are shown. AMS, independent of any separation technique to which it may be coupled, is shown to be accurate, linear, precise, and robust. As the sensitivity and universality of AMS is constantly being explored and expanded, this work underpins many areas of pharmaceutical development including drug metabolism as well as absorption, distribution and excretion of pharmaceutical compounds as a fundamental step in drug development. The validation parameters for pharmaceutical analyses were examined for the accelerator mass spectrometry measurement of {sup 14}C/C ratio, independent of chemical separation procedures. The isotope ratio measurement was specific (owing to the {sup 14}C label), stable across samples storage conditions for at least one year, linear over 4 orders of magnitude with an analytical range from one tenth Modern to at least 2000 Modern (instrument specific). Further, accuracy was excellent between 1 and 3 percent while precision expressed as coefficient of variation is between 1 and 6% determined primarily by radiocarbon content and the time spent analyzing a sample. Sensitivity, expressed as LOD and LLOQ was 1 and 10 attomoles of carbon-14 (which can be expressed as compound equivalents) and for a typical small molecule labeled at 10% incorporated with {sup 14}C corresponds to 30 fg equivalents. AMS provides an sensitive, accurate and precise method of measuring drug compounds in biological matrices.

Keck, B D; Ognibene, T; Vogel, J S

2010-02-05T23:59:59.000Z

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

New FORTRAN computer programs to acquire and process isotopic mass spectrometric data: Operator`s manual  

SciTech Connect (OSTI)

This TM is one of a pair that describes ORNL-developed software for acquisition and processing of isotope ratio mass spectral data. This TM is directed at the laboratory analyst. No technical knowledge of the programs and programming is required. It describes how to create and edit files, how to acquire and process data, and how to set up files to obtain the desired results. The aim of this TM is to serve as a utilitarian instruction manual, a {open_quotes}how to{close_quotes} approach rather than a {open_quotes}why?{close_quotes}

Smith, D.H.; McKown, H.S.

1993-09-01T23:59:59.000Z

22

Examination of the rate of peptide biosynthesis in neuroendocrine cell lines using a stable isotopic label and mass spectrometry  

E-Print Network [OSTI]

isotopic label and mass spectrometry Fa-Yun Che,*,1 Quan Yuan,* ,1 Elena Kalinina* and Lloyd D. Fricker-Leu) and used mass spectrometry to measure the biosynthetic rate of c-lipotropin in the AtT-20 cell lines. Keywords: carboxypeptidase, gamma-lipotropin, insulin, prohormone convertase, proinsulin

Tian, Weidong

23

New precision mass measurements of neutron-rich calcium and potassium isotopes and three-nucleon forces  

E-Print Network [OSTI]

We present precision Penning-trap mass measurements of neutron-rich calcium and potassium isotopes in the vicinity of neutron number N=32. Using the TITAN system the mass of $^{51}$K was measured for the first time, and the precision of the $^{51,52}$Ca mass values were improved significantly. The new mass values show a dramatic increase of the binding energy compared to those reported in the atomic mass evaluation. In particular, $^{52}$Ca is more bound by 1.74 MeV, and the behavior with neutron number deviates substantially from the tabulated values. An increased binding was predicted recently based on calculations that include three-nucleon (3N) forces. We present a comparison to improved calculations, which agree remarkably with the evolution of masses with neutron number, making neutron-rich calcium isotopes an exciting region to probe 3N forces at neutron-rich extremes.

A. T. Gallant; J. C. Bale; T. Brunner; U. Chowdhury; S. Ettenauer; A. Lennarz; D. Robertson; V. V. Simon; A. Chaudhuri; J. D. Holt; A. A. Kwiatkowski; E. Mané; J. Menéndez; B. E. Schultz; M. C. Simon; C. Andreoiu; P. Delheij; M. R. Pearson; H. Savajols; A. Schwenk; J. Dilling

2012-04-09T23:59:59.000Z

24

Standard test method for isotopic abundance analysis of uranium hexa?uoride and uranyl nitrate solutions by multi-collector, inductively coupled plasma-mass spectrometry  

E-Print Network [OSTI]

Standard test method for isotopic abundance analysis of uranium hexa?uoride and uranyl nitrate solutions by multi-collector, inductively coupled plasma-mass spectrometry

American Society for Testing and Materials. Philadelphia

2008-01-01T23:59:59.000Z

25

Assessment of Non-traditional Isotopic Ratios by Mass Spectrometry for Analysis of Nuclear Activities: Annual Report Year 2  

SciTech Connect (OSTI)

The objective of this work is to identify isotopic ratios suitable for analysis via mass spectrometry that distinguish between commercial nuclear reactor fuel cycles, fuel cycles for weapons grade plutonium, and products from nuclear weapons explosions. Methods will also be determined to distinguish the above from medical and industrial radionuclide sources. Mass spectrometry systems will be identified that are suitable for field measurement of such isotopes in an expedient manner. Significant progress has been made with this project within the past year: (1) Isotope production from commercial nuclear fuel cycles and nuclear weapons fuel cycles have been modeled with the ORIGEN and MCNPX codes. (2) MCNPX has been utilized to calculate isotopic inventories produced in a short burst fast bare sphere reactor (to approximate the signature of a nuclear weapon). (3) Isotopic ratios have been identified that are good for distinguishing between commercial and military fuel cycles as well as between nuclear weapons and commercial nuclear fuel cycles. (4) Mass spectrometry systems have been assessed for analysis of the fission products of interest. (5) A short-list of forensic ratios have been identified that are well suited for use in portable mass spectrometry systems.

Biegalski, S; Buchholz, B

2009-08-26T23:59:59.000Z

26

Isotope mass shift for two-electron atoms Petersburg Nuclear Physics Institute, Gatchina, 188300, Russia  

E-Print Network [OSTI]

, 188300, Russia (Dated: 29 April 2004) Accurate calculations of the isotope shift for atomic transitions

Kozlov, Mikhail G

27

Isotope mass shift for two-electron atoms II Petersburg Nuclear Physics Institute, Gatchina, 188300, Russia  

E-Print Network [OSTI]

, Gatchina, 188300, Russia (Dated: 31 October 2006) Accurate calculations of the isotope shift for atomic

Kozlov, Mikhail G

28

Quantifying Uranium Isotope Ratios Using Resonance Ionization Mass Spectrometry: The Influence of Laser Parameters on Relative Ionization Probability  

SciTech Connect (OSTI)

Resonance Ionization Mass Spectrometry (RIMS) has been developed as a method to measure relative uranium isotope abundances. In this approach, RIMS is used as an element-selective ionization process to provide a distinction between uranium atoms and potential isobars without the aid of chemical purification and separation. We explore the laser parameters critical to the ionization process and their effects on the measured isotope ratio. Specifically, the use of broad bandwidth lasers with automated feedback control of wavelength was applied to the measurement of {sup 235}U/{sup 238}U ratios to decrease laser-induced isotopic fractionation. By broadening the bandwidth of the first laser in a 3-color, 3-photon ionization process from a bandwidth of 1.8 GHz to about 10 GHz, the variation in sequential relative isotope abundance measurements decreased from >10% to less than 0.5%. This procedure was demonstrated for the direct interrogation of uranium oxide targets with essentially no sample preparation. A rate equation model for predicting the relative ionization probability has been developed to study the effect of variation in laser parameters on the measured isotope ratio. This work demonstrates that RIMS can be used for the robust measurement of uranium isotope ratios.

Isselhardt, B H

2011-09-06T23:59:59.000Z

29

Analyzing Nuclear Fuel Cycles from Isotopic Ratios of Waste Products Applicable to Measurement by Accelerator Mass Spectrometry  

SciTech Connect (OSTI)

An extensive study was conducted to determine isotopic ratios of nuclides in spent fuel that may be utilized to reveal historical characteristics of a nuclear reactor cycle. This forensic information is important to determine the origin of unknown nuclear waste. The distribution of isotopes in waste products provides information about a nuclear fuel cycle, even when the isotopes of uranium and plutonium are removed through chemical processing. Several different reactor cycles of the PWR, BWR, CANDU, and LMFBR were simulated for this work with the ORIGEN-ARP and ORIGEN 2.2 codes. The spent fuel nuclide concentrations of these reactors were analyzed to find the most informative isotopic ratios indicative of irradiation cycle length and reactor design. Special focus was given to long-lived and stable fission products that would be present many years after their creation. For such nuclides, mass spectrometry analysis methods often have better detection limits than classic gamma-ray spectroscopy. The isotopic ratios {sup 151}Sm/{sup 146}Sm, {sup 149}Sm/{sup 146}Sm, and {sup 244}Cm/{sup 246}Cm were found to be good indicators of fuel cycle length and are well suited for analysis by accelerator mass spectroscopy.

Biegalski, S R; Whitney, S M; Buchholz, B

2005-08-24T23:59:59.000Z

30

Precise ruthenium fission product isotopic analysis using dynamic reaction cell inductively coupled plasma mass spectrometry (DRC-ICP-MS)  

SciTech Connect (OSTI)

99Tc is a subsurface contaminant of interest at numerous federal, industrial, and international facilities. However, as a mono-isotopic fission product, 99Tc lacks the ability to be used as a signature to differentiate between the different waste disposal pathways that could have contributed to subsurface contamination at these facilities. Ruthenium fission-product isotopes are attractive analogues for the characterization of 99Tc sources because of their direct similarity to technetium with regard to subsurface mobility, and their large fission yields and low natural background concentrations. We developed an inductively coupled plasma mass spectrometry (ICP-MS) method capable of measuring ruthenium isotopes in groundwater samples and extracts of vadose zone sediments. Samples were analyzed directly on a Perkin Elmer ELAN DRC II ICP-MS after a single pass through a 1-ml bed volume of Dowex AG 50W-X8 100-200 mesh cation exchange resin. Precise ruthenium isotopic ratio measurements were achieved using a low-flow Meinhard-type nebulizer and long sample acquisition times (150,000 ms). Relative standard deviations of triplicate replicates were maintained at less than 0.5% when the total ruthenium solution concentration was 0.1 ng/ml or higher. Further work was performed to minimize the impact caused by mass interferences using the dynamic reaction cell (DRC) with O2 as the reaction gas. The aqueous concentrations of 96Mo and 96Zr were reduced by more than 99.7% in the reaction cell prior to injection of the sample into the mass analyzer quadrupole. The DRC was used in combination with stable-mass correction to quantitatively analyze samples containing up to 2-orders of magnitude more zirconium and molybdenum than ruthenium. The analytical approach documented herein provides an efficient and cost-effective way to precisely measure ruthenium isotopes and quantitate total ruthenium (natural vs. fission-product) in aqueous matrixes.

Brown, Christopher F.; Dresel, P. Evan; Geiszler, Keith N.; Farmer, Orville T.

2006-05-09T23:59:59.000Z

31

Standard test method for isotopic analysis of uranium hexafluoride by double standard single-collector gas mass spectrometer method  

E-Print Network [OSTI]

1.1 This is a quantitative test method applicable to determining the mass percent of uranium isotopes in uranium hexafluoride (UF6) samples with 235U concentrations between 0.1 and 5.0 mass %. 1.2 This test method may be applicable for the entire range of 235U concentrations for which adequate standards are available. 1.3 This test method is for analysis by a gas magnetic sector mass spectrometer with a single collector using interpolation to determine the isotopic concentration of an unknown sample between two characterized UF6 standards. 1.4 This test method is to replace the existing test method currently published in Test Methods C761 and is used in the nuclear fuel cycle for UF6 isotopic analyses. 1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appro...

American Society for Testing and Materials. Philadelphia

2010-01-01T23:59:59.000Z

32

Standard test method for isotopic analysis of hydrolyzed uranium hexafluoride and uranyl nitrate solutions by thermal ionization mass spectrometry  

E-Print Network [OSTI]

1.1 This method applies to the determination of isotopic composition in hydrolyzed nuclear grade uranium hexafluoride. It covers isotopic abundance of 235U between 0.1 and 5.0 % mass fraction, abundance of 234U between 0.0055 and 0.05 % mass fraction, and abundance of 236U between 0.0003 and 0.5 % mass fraction. This test method may be applicable to other isotopic abundance providing that corresponding standards are available. 1.2 This test method can apply to uranyl nitrate solutions. This can be achieved either by transforming the uranyl nitrate solution to a uranyl fluoride solution prior to the deposition on the filaments or directly by depositing the uranyl nitrate solution on the filaments. In the latter case, a calibration with uranyl nitrate standards must be performed. 1.3 This test method can also apply to other nuclear grade matrices (for example, uranium oxides) by providing a chemical transformation to uranyl fluoride or uranyl nitrate solution. 1.4 This standard does not purport to address al...

American Society for Testing and Materials. Philadelphia

2005-01-01T23:59:59.000Z

33

A Hydrogen Isotope of Mass 2 Before the publication of this definitive paper on the  

E-Print Network [OSTI]

. They probably estimated the chemical differences among isotopes to be small, perhaps too small to be measured, spectrographic evidence for the lines of 2 H obtained from samples of commercial tank hydro- gen. These lines

34

DETERMINATION OF 237NP AND PU ISOTOPES IN LARGE SOIL SAMPLES BY INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY  

SciTech Connect (OSTI)

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, {sup 242}Pu and {sup 237}Np were measured by ICP-MS, while {sup 236}Pu and {sup 238}Pu were measured by alpha spectrometry.

Maxwell, S.

2010-07-26T23:59:59.000Z

35

Caution on the Use of Liquid Nitrogen Traps in Stable Hydrogen Isotope-Ratio Mass Spectrometry  

E-Print Network [OSTI]

-mail: tbcoplen@usgs.gov. (1) Kirshenbaum, I. In Physical Properties and Analysis of Heavy Water; Urey, H. C with the process of adding liquid nitrogen (LN2) to top off the dewar of a stainless-steel water trap on a gaseous hydrogen-water platinum equilibration system. Al- though the cause of this isotopic fractionation

36

Intramolecular Isotope Effects for the Study of Reactions with MassTransfer Limitations  

E-Print Network [OSTI]

Page Figure 1 The origin of the kinetic isotope effect.............................................. 15 Figure 2 The solvent cage complexes of substrate and radical in intermolecular case............................................................................... 16 Figure 3 The solvent cage complex of substrate and radical in the intramolecular case ............................................................................ 17 Figure 4 Hydrogens to be used to calculate intermolecular KIE...

Wagner, Joshua G.

2010-01-16T23:59:59.000Z

37

RAPID DETERMINATION OF 237 NP AND PU ISOTOPES IN WATER BY INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY AND ALPHA SPECTROMETRY  

SciTech Connect (OSTI)

A new method that allows rapid preconcentration and separation of plutonium and neptunium in water samples was developed for the measurement of {sup 237}Np and Pu isotopes by inductively-coupled plasma mass spectrometry (ICP-MS) and alpha spectrometry; a hybrid approach. {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 peak tailing. The method provide enhanced removal of uranium by separating Pu and Np initially on TEVA Resin, then moving Pu to DGA resin for additional removal of uranium. The decontamination factor for uranium from Pu is almost 100,000 and the decontamination factor for U from Np is greater than 10,000. This method uses stacked extraction chromatography cartridges and vacuum box technology to facilitate rapid separations. Preconcentration is performed using a streamlined calcium phosphate precipitation method. Purified solutions are split between ICP-MS and alpha spectrometry so that long and short-lived Pu isotopes can be measured successfully. The method allows for simultaneous extraction of 20 samples (including QC samples) in 4 to 6 hours, and can also be used for emergency response. {sup 239}Pu, {sup 242}Pu and {sup 237}Np were measured by ICP-MS, while {sup 236}Pu, {sup 238}Pu, and {sup 239}Pu were measured by alpha spectrometry.

Maxwell, S.; Jones, V.; Culligan, B.; Nichols, S.; Noyes, G.

2010-06-23T23:59:59.000Z

38

Isotopic ratios and effective power determined by gamma-ray spectroscopy vs mass spectroscopy for molten salt extraction residues  

SciTech Connect (OSTI)

Impure plutonium metal is routinely processed by molten salt extraction (MSE) to reduce the amount of americium in the metal product. Throughput at various facilities where similar processes are performed has made it essential to evaluate uncertainties and possible discrepancies in the analyses of these difficult MSE materials. In an effort to evaluate the plutonium isotopic ratios and americium concentrations obtained from gamma-ray spectral data analyzed by the computer code GRPAUT, measurements were made on ten MSE salts as received and after pulverization and blending. These results were then compared to the specific powers obtained from isotopic ratios determined by mass spectrometry on these same ten samples. Americium values ranged from a few thousand parts-per-million of total plutonium to greater than 50,000 ppM. Our results indicate a small discrepancy between specific powers as determined by GRPAUT on as received'' vs pulverized and blended MSE salts. The specific powers obtained via GRPAUT on the pulverized salts agree somewhat better with specific powers obtained from the mass spectroscopy data. This work may indicate that a small discrepancy exists in the specific powers by using GRPAUT on heterogeneous, high americium samples. 5 refs., 6 tabs.

Longmire, V.L.; Cremers, T.L.; Sedlacek, W.A.; Long, S.M.; Scarborough, A.M.; Hurd, J.R.

1990-01-01T23:59:59.000Z

39

Measurement of positional isotope exchange rates in enzyme catalyzed reactions by fast atom bombardment mass spectrometry  

E-Print Network [OSTI]

- tope peak would be expected to occur. (A): The enzyme was incu- 18 bated with citrulline and (8&- 0 )ATP. (B): The enzyme was incu- 6 bated with citrulline, succinate, and, PT- 0 )ATP. (C): The ( 18 enzyme was incubated wi+h ATP and (ureido- 0)ci...

Hilscher, Larry Wayne

1985-01-01T23:59:59.000Z

40

Development of a portable mass spectrometric system for determination of isotopic composition of solid uranium samples using fluorine volatilization. Final report  

SciTech Connect (OSTI)

Using hardware and materials supplied by LANL, a prototype quadrupole mass spectrometer system designed for portable field analysis of isotopic composition of solid uranium samples was assembled and tested. The system contained the capability for fluorine volatilization of solid uranium samples with gas introduction, which was successfully tested and demonstrated using 100 mg samples of U{sub 3}O{sub 8}. Determination of precision and accuracy for measuring isotopic composition was performed using isotopic standards. Use with soil samples containing uranium were also attempted. Silicates in the soil forming SiF{sub 4} were found to be a kinetic bottleneck to the formation of UF{sub 6}. This could be avoided by performing some sort of chemical separation as a pre-treatment step, which was demonstrated using nitric acid.

Loge, G.

1994-09-30T23:59:59.000Z

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Accurate determination of Curium and Californium isotopic ratios by inductively coupled plasma quadrupole mass spectrometry (ICP-QMS) in 248Cm samples for transmutation studies  

SciTech Connect (OSTI)

The French Atomic Energy Commission has carried out several experiments including the mini-INCA (INcineration of Actinides) project for the study of minor-actinide transmutation processes in high intensity thermal neutron fluxes, in view of proposing solutions to reduce the radiotoxicity of long-lived nuclear wastes. In this context, a Cm sample enriched in {sup 248}Cm ({approx}97 %) was irradiated in thermal neutron flux at the High Flux Reactor (HFR) of the Laue-Langevin Institute (ILL). This work describes a quadrupole ICP-MS (ICP-QMS) analytical procedure for precise and accurate isotopic composition determination of Cm before sample irradiation and of Cm and Cf after sample irradiation. The factors that affect the accuracy and reproducibility of isotopic ratio measurements by ICP-QMS, such as peak centre correction, detector dead time, mass bias, abundance sensitivity and hydrides formation, instrumental background, and memory blank were carefully evaluated and corrected. Uncertainties of the isotopic ratios, taking into account internal precision of isotope ratio measurements, peak tailing, and hydrides formations ranged from 0.3% to 1.3%. This uncertainties range is quite acceptable for the nuclear data to be used in transmutation studies.

Gourgiotis, A.; Isnard, H.; Aubert, M.; Dupont, E.; AlMahamid, I.; Cassette, P.; Panebianco, S.; Letourneau, A.; Chartier, F.; Tian, G.; Rao, L.; Lukens, W.

2011-02-01T23:59:59.000Z

42

A World without Sample Preparation: Developing Rapid Uranium Isotope Measurement Capabilities by Resonance Ionization Mass Spectrometry (RIMS)  

SciTech Connect (OSTI)

We are developing highly sensitive, highly discriminating laser-based techniques for rapid determination of isotopic compositions. Rapid command of such information is critical to assessment of the origin and history of nuclear materials, particularly in post-detonation scenarios.

Knight, K B; Hutcheon, I D; Isselhardt, B H; Savina, M R; Prussin, S G

2009-06-08T23:59:59.000Z

43

The Uncertainties in the 22Ne + alpha-capture Reaction Rates and the Production of the Heavy Magnesium Isotopes in Asymptotic Giant Branch Stars of Intermediate Mass  

E-Print Network [OSTI]

We present new rates for the 22Ne(alpha, n)25Mg and 22Ne(alpha,gamma)26Mg reactions, with uncertainties that have been considerably reduced compared to previous estimates, and we study how these new rates affect the production of the heavy magnesium isotopes in models of intermediate mass Asymptotic Giant Branch (AGB) stars of different initial compositions. All the models have deep third dredge-up, hot bottom burning and mass loss. Calculations have been performed using the two most commonly used estimates of the 22Ne + alpha rates as well as the new recommended rates, and with combinations of their upper and lower limits. The main result of the present study is that with the new rates, uncertainties on the production of isotopes from Mg to P coming from the 22Ne + alpha-capture rates have been considerably reduced. We have therefore removed one of the important sources of uncertainty to effect models of AGB stars. We have studied the effects of varying the mass-loss rate on nucleosynthesis and discuss other uncertainties related to the physics employed in the computation of stellar structure, such as the modeling of convection, the inclusion of a partial mixing zone and the definition of convective borders. These uncertainties are found to be much larger than those coming from 22Ne + alpha-capture rates, when using our new estimates. Much effort is needed to improve the situation for AGB models.

A. Karakas; M. Lugaro; M. Wiescher; J. Goerres; C. Ugalde

2006-01-27T23:59:59.000Z

44

Calculation of Transactinide Homolog Isotope Production Reactions Possible with the Center for Accelerator Mass Spectrometry (CAMS) at Lawrence Livermore National Laboratory  

SciTech Connect (OSTI)

The LLNL heavy element group has been investigating the chemical properties of the heaviest elements over the past several years. The properties of the transactinides (elements with Z > 103) are often unknown due to their low production rates and short half-lives, which require lengthy cyclotron irradiations in order to make enough atoms for statistically significant evaluations of their chemistry. In addition, automated chemical methods are often required to perform consistent and rapid chemical separations on the order of minutes for the duration of the experiment, which can last from weeks to months. Separation methods can include extraction chromatography, liquid-liquid extraction, or gas-phase chromatography. Before a lengthy transactinide experiment can be performed at an accelerator, a large amount of preparatory work must be done both to ensure the successful application of the chosen chemical system to the transactinide chemistry problem being addressed, and to evaluate the behavior of the lighter elemental homologs in the same chemical system. Since transactinide chemistry is literally performed on one single atom, its chemical properties cannot be determined from bulk chemical matrices, but instead must be inferred from the behavior of the lighter elements that occur in its chemical group and in those of its neighboring elements. By first studying the lighter group homologs in a particular chemical system, when the same system is applied to the transactinide element under investigation, its decay properties can be directly compared to those of the homologues, thereby allowing an inference of its own chemistry. The Center for Accelerator Mass Spectrometry (CAMS) at Lawrence Livermore National Laboratory (LLNL) includes a 1 MV Tandem accelerator, capable of accelerating light ions such as protons to energies of roughly 15 MeV. By using the CAMS beamline, tracers of transactinide homolog elements can be produced both for development of chemical systems and for evaluation of homolog chemical properties. CAMS also offers an environment for testing these systems 'online' by incorporating automated chemical systems into the beamline so that tracers can be created, transported, and chemically separated all on the shorter timescales required for transactinide experiments. Even though CAMS is limited in the types and energies of ions they can accelerate, there are still a wide variety of reactions that can be performed there with commercially available target materials. The half-lives of these isotopes vary over a range that could be used for both online chemistry (where shorter half-lives are required) and benchtop tracers studies (where longer lived isotopes are preferred). In this document, they present a summary of tracer production reactions that could be performed at CAMS, specifically for online, automated chemical studies. They are from chemical groups four through seven, 13, and 14, which would be appropriate for studies of elements 104-107, 113, and 114. Reactions were selected that had (a) commercially available target material, (b) half-lives long enough for transport from a target chamber to an automated chemistry system, and (c) cross-sections at CAMS available projectile energies that were large enough to produce enough atoms to result in a statistically relevant signal after losses for transport and chemistry were considered. In addition, the resulting product atoms had to decay with an observable gamma-ray using standard Ge gamma-ray detectors. The table includes calculations performed for both metal targets and their corresponding oxides.

Moody, K J; Shaughnessy, D A; Gostic, J M

2011-11-29T23:59:59.000Z

45

Mass-dependent fractionation of quadruple stable sulfur isotope system as a new tracer of sulfur biogeochemical cycles  

E-Print Network [OSTI]

- ing rare isotopes for Earth materials was the discovery of anomalous 17 O abundance in a wide variety, USA b Department of Geology and Earth System Science Interdisciplinary Center, University of Maryland and extraterrestrial materials. Ã? 2006 Elsevier Inc. All rights reserved. 1. Introduction Sulfur (32 S, 33 S, 34 S

Long, Bernard

46

Solid-state Marx based two-switch voltage modulator for the On-Line Isotope Mass Separator accelerator at the European Organization for Nuclear Research  

SciTech Connect (OSTI)

A new circuit topology is proposed to replace the actual pulse transformer and thyratron based resonant modulator that supplies the 60 kV target potential for the ion acceleration of the On-Line Isotope Mass Separator accelerator, the stability of which is critical for the mass resolution downstream separator, at the European Organization for Nuclear Research. The improved modulator uses two solid-state switches working together, each one based on the Marx generator concept, operating as series and parallel switches, reducing the stress on the series stacked semiconductors, and also as auxiliary pulse generator in order to fulfill the target requirements. Preliminary results of a 10 kV prototype, using 1200 V insulated gate bipolar transistors and capacitors in the solid-state Marx circuits, ten stages each, with an electrical equivalent circuit of the target, are presented, demonstrating both the improved voltage stability and pulse flexibility potential wanted for this new modulator.

Redondo, L. M.; Canacsinh, H.; Ferrao, N.; Mendes, C. [Instituto Superior de Engenharia de Lisboa (ISEL), R. Conselheiro Emidio Navarro 1, Lisbon 1959-007 (Portugal); Nuclear Physics Center-Lisbon University (CFNUL), Av. Prof. Gama Pinto 2, Lisbon 1649-003 (Portugal); Silva, J. Fernando [Instituto Superior Tecnico (IST), Universidade Tecnica de Lisboa, Av. Rovisco Pais 1, Lisbon 1049-001 (Portugal); Center for Innovation in Electrical and Energy Engineering-TU Lisbon, Av. Rovisco Pais 1, Lisbon 1049-001 (Portugal); Soares, R. [Nuclear Physics Center--Lisbon University (CFNUL), Av. Prof. Gama Pinto 2, Lisbon 1649-003 (Portugal); ABT Group, TE Department, Site de Prevessin, FR-01631 CERN (Switzerland); Schipper, J.; Fowler, A. [ABT Group, TE Department, Site de Prevessin, FR-01631 CERN (Switzerland)

2010-07-15T23:59:59.000Z

47

Standard test method for analysis of isotopic composition of uranium in nuclear-grade fuel material by quadrupole inductively coupled plasma-mass spectrometry  

E-Print Network [OSTI]

1.1 This test method is applicable to the determination of the isotopic composition of uranium (U) in nuclear-grade fuel material. The following isotopic weight percentages are determined using a quadrupole inductively coupled plasma-mass spectrometer (Q-ICP-MS): 233U, 234U, 235U, 236U, and 238U. The analysis can be performed on various material matrices after acid dissolution and sample dilution into water or dilute nitric (HNO3) acid. These materials include: fuel product, uranium oxide, uranium oxide alloys, uranyl nitrate (UNH) crystals, and solutions. The sample preparation discussed in this test method focuses on fuel product material but may be used for uranium oxide or a uranium oxide alloy. Other preparation techniques may be used and some references are given. Purification of the uranium by anion-exchange extraction is not required for this test method, as it is required by other test methods such as radiochemistry and thermal ionization mass spectroscopy (TIMS). This test method is also described i...

American Society for Testing and Materials. Philadelphia

2000-01-01T23:59:59.000Z

48

Standard Test Method for Isotopic Analysis of Uranium Hexafluoride by Single-Standard Gas Source Multiple Collector Mass Spectrometer Method  

E-Print Network [OSTI]

1.1 This test method is applicable to the isotopic analysis of uranium hexafluoride (UF6) with 235U concentrations less than or equal to 5 % and 234U, 236U concentrations of 0.0002 to 0.1 %. 1.2 This test method may be applicable to the analysis of the entire range of 235U isotopic compositions providing that adequate Certified Reference Materials (CRMs or traceable standards) are available. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety health practices and determine the applicability of regulatory limitations prior to use.

American Society for Testing and Materials. Philadelphia

2011-01-01T23:59:59.000Z

49

Isotope hydrology of catchment basins: lithogenic and cosmogenic isotopic systems  

SciTech Connect (OSTI)

A variety of physical processes affect solute concentrations within catchment waters. The isotopic compositions of the solutes can indicate which processes have determined the observed concentrations. These processes together constitute the physical history of the water. Many solutes in natural waters are derived from the interaction between the water and the rock and/or soil within the system - these are termed `lithogenic` solutes. The isotopic compositions of these solutes provide information regarding rock-water interactions. Many other solutes have their isotopic compositions determined both within and outside of the catchment - i.e., in addition to being derived from catchment rock and soil, they are solutes that are also transported into the catchment. Important members of this group include solutes that have isotopic compositions produced by atomic particle interactions with other nuclides. The source of the atomic particles can be cosmic radiation (producing `cosmogenic` nuclides in the atmosphere and land surface), anthropogenic nuclear reactions (producing `thermonuclear` nuclides), or radioactive and fission decay of naturally-occurring elements, principally {sup 238}U (producing `in-situ` lithogenic nuclides in the deep subsurface). Current language usage often combines all of the atomic particle-produced nuclides under the heading `cosmogenic nuclides`, and for simplicity we will often follow that usage here, although always indicating which variety is being discussed. This paper addresses the processes that affect the lithogenic and cosmogenic solute concentrations in catchment waters, and how the isotopic compositions of the solutes can be used in integrative ways to identify these processes, thereby revealing the physical history of the water within a catchment system. The concept of a `system` is important in catchment hydrology. A catchment is the smallest landscape unit that can both participate in all of the aspects of the hydrologic cycle and also be treated as a mostly closed system for mass balance considerations. It is the near closure of the system that permits well- constrained chemical mass balance calculations to be made. These calculations generally focus of lithogenic solutes, and therefore in our discussions of lithogenic nuclides in the paper, the concept of chemical mass balance in a nearly dosed system will play an important role. Examination of the isotopic compositions of solutes provides a better understanding of the variety of processes controlling mass balance. It is with this approach that we examined the variety of processes occurring within the catchment system, such as weathering and soil production, generation of stormflow and streamflow (hydrograph separation), movement of soil pore water, groundwater flow, and the overall processes involved with basinal water balance. In this paper, the term `nuclide` will be used when referring to a nuclear species that contains a particular number of protons and neutrons. The term is not specific to any element. The term `isotope` will be used to distinguish nuclear species of a given element (atoms with the same number of protons). That is to say, there are many nuclides in nature - for example, {sup 36}Cl, {sup 87}Sr, {sup 238}U; the element has four naturally-occurring isotopes - {sup 87}Sr, and {sup 88}Sr. This paper will first discuss the general principles that underlie the study of lithogenic and cosmogenic nuclides in hydrology, and provide references to some of the more important studies applying these principles and nuclides. We then turn in the second section to a discussion of their specific applications in catchment- scale systems. The final section of this paper discusses new directions in the application of lithogenic and cosmogenic nuclides to catchment hydrology, with some thoughts concerning possible applications that still remain unexplored.

Nimz, G. J., LLNL

1998-06-01T23:59:59.000Z

50

Development of high through-put Sr isotope analysis for monitoring reservoir integrity for CO{sub 2} storage.  

SciTech Connect (OSTI)

Recent innovations in multi-collector ICP-mass spectrometry (MC-ICP-MS) have allowed for rapid and precise measurements of isotope ratios in geological samples. Naturally occurring Sr isotopes has the potential for use in Monitoring, Verification, and Accounting (MVA) associated with geologic CO2 storage. Sr isotopes can be useful for: Sensitive tracking of brine migration; Determining seal rock leakage; Studying fluid/rock reactions. We have optimized separation chemistry procedures that will allow operators to prepare samples for Sr isotope analysis off site using rapid, low cost methods.

Wall, Andy; Jain, Jinesh; Stewart, Brian; Capo, Rosemary; Hakala, Alexandra J.; Hammack, Richard; Guthrie, George

2012-01-01T23:59:59.000Z

51

Characterization of Diesel Fuel by Chemical Separation Combined with Capillary Gas Chromatography (GC) Isotope Ratio Mass Spectrometry (IRMS)  

SciTech Connect (OSTI)

The purpose of this study was to perform a preliminary investigation of compound-specific isotope analysis (CSIA) of diesel fuels to evaluate whether the technique could distinguish between the diesel samples from different sources/locations. The ability to differentiate or correlate diesel samples could be valuable for detecting fuel tax evasion schemes. Two fractionation techniques were used to isolate the n-alkanes from the fuel. Both ?13C and ?D values for the n-alkanes were then determined by CSIA in each sample. Plots of ?D versus ?13C with sample n-alkane points connected in order of increasing carbon number gave well separated clusters with characteristic shapes for each sample. Principal components analysis (PCA) with ?13C, ?D, or combined ?13C and ?D data on the yielded scores plots that could clearly differentiate the samples, thereby demonstrating the potential of this approach for fingerprinting fuel samples using the ?13C and ?D values.

Harvey, Scott D.; Jarman, Kristin H.; Moran, James J.; Sorensen, Christina M.; Wright, Bob W.

2011-09-15T23:59:59.000Z

52

Laser isotope separation  

DOE Patents [OSTI]

A process and apparatus for separating isotopes by selective excitation of isotopic species of a volatile compound by tuned laser light. A highly cooled gas of the volatile compound is produced in which the isotopic shift is sharpened and defined. Before substantial condensation occurs, the cooled gas is irradiated with laser light precisely tuned to a desired wavelength to selectively excite a particular isotopic species in the cooled gas. The laser light may impart sufficient energy to the excited species to cause it to undergo photolysis, photochemical reaction or even to photoionize. Alternatively, a two-photon irradiation may be applied to the cooled gas to induce photolysis, photochemical reaction or photoionization. The process is particularly applicable to the separation of isotopes of uranium.

Robinson, C. Paul (Los Alamos, NM); Jensen, Reed J. (Los Alamos, NM); Cotter, Theodore P. (Munich, DE); Boyer, Keith (Los Alamos, NM); Greiner, Norman R. (Los Alamos, NM)

1988-01-01T23:59:59.000Z

53

Photochemical isotope separation  

DOE Patents [OSTI]

A process for separating isotopes by selective excitation of isotopic species of a volatile compound by tuned laser light. A highly cooled gas of the volatile compound is produced in which the isotopic shift is sharpened and defined. Before substantial condensation occurs, the cooled gas is irradiated with laser light precisely tuned to a desired wavelength to selectively excite a particular isotopic species in the cooled gas. The laser light may impart sufficient energy to the excited species to cause it to undergo photochemical reaction or even to photoionize. Alternatively, a two-photon irradiation may be applied to the cooled gas to induce photochemical reaction or photoionization. The process is particularly applicable to the separation of isotopes of uranium and plutonium.

Robinson, C. Paul (Los Alamos, NM); Jensen, Reed J. (Los Alamos, NM); Cotter, Theodore P. (Los Alamos, NM); Greiner, Norman R. (Los Alamos, NM); Boyer, Keith (Los Alamos, NM)

1987-01-01T23:59:59.000Z

54

Photochemical isotope separation  

DOE Patents [OSTI]

A process is described for separating isotopes by selective excitation of isotopic species of a volatile compound by tuned laser light. A highly cooled gas of the volatile compound is produced in which the isotopic shift is sharpened and defined. Before substantial condensation occurs, the cooled gas is irradiated with laser light precisely tuned to a desired wavelength to selectively excite a particular isotopic species in the cooled gas. The laser light may impart sufficient energy to the excited species to cause it to undergo photochemical reaction or even to photoionize. Alternatively, a two-photon irradiation may be applied to the cooled gas to induce photochemical reaction or photoionization. The process is particularly applicable to the separation of isotopes of uranium and plutonium. 8 figs.

Robinson, C.P.; Jensen, R.J.; Cotter, T.P.; Greiner, N.R.; Boyer, K.

1987-04-28T23:59:59.000Z

55

Natural mercury isotope variation in coal deposits and organic soils  

SciTech Connect (OSTI)

There is a need to distinguish among sources of Hg to the atmosphere in order to more fully understand global Hg pollution. In this study we investigate whether coal deposits within the United States, China, and Russia-Kazakhstan, which are three of the five greatest coal-producing regions, have diagnostic Hg isotopic fingerprints that can be used to discriminate among Hg sources. We also investigate the Hg isotopic composition of modern organic soil horizons developed in areas distant from point sources of Hg in North America. Mercury stored in coal deposits displays a wide range of both mass dependent fractionation and mass independent fractionation. {delta}{sup 202}Hg varies in coals by 3{per_thousand} and {Delta}{sup 201}Hg varies by 0.9{per_thousand}. Combining these two Hg isotope signals results in what may be a unique isotopic 'fingerprint' for many coal deposits. Mass independent fractionation of mercury has been demonstrated to occur during photochemical reactions of mercury. This suggests that Hg found in most coal deposits was subjected to photochemical reduction near the Earth's surface prior to deposition. The similarity in MDF and MIF of modern organic soils and coals from North America suggests that Hg deposition from coal may have imprinted an isotopic signature on soils. This research offers a new tool for characterizing mercury inputs from natural and anthropogenic sources to the atmosphere and provides new insights into the geochemistry of mercury in coal and soils. 35 refs., 2 figs., 1 tab.

Abir, Biswas; Joel D. Blum; Bridget A. Bergquist; Gerald J. Keeler; Zhouqing Xie [University of Michigan, Ann Arbor, MI (United States). Department of Geological Sciences

2008-11-15T23:59:59.000Z

56

Isotope separation by laser means  

DOE Patents [OSTI]

A process for separating isotopes by selective excitation of isotopic species of a volatile compound by tuned laser light. A highly cooled gas of the volatile compound is produced in which the isotopic shift is sharpened and defined. Before substantial condensation occurs, the cooled gas is irradiated with laser light precisely tuned to a desired wavelength to selectively excite a particular isotopic species in the cooled gas. The laser light may impart sufficient energy to the excited species to cause it to undergo photochemical reaction or even to photoionize. Alternatively, a two-photon irradiation may be applied to the cooled gas to induce photochemical reaction or photoionization. The process is particularly applicable to the separation of isotopes of uranium and plutonium.

Robinson, C. Paul (Los Alamos, NM); Jensen, Reed J. (Los Alamos, NM); Cotter, Theodore P. (Los Alamos, NM); Greiner, Norman R. (Los Alamos, NM); Boyer, Keith (Los Alamos, NM)

1982-06-15T23:59:59.000Z

57

Search for long-lived isomeric states in neutron-deficient thorium isotopes  

SciTech Connect (OSTI)

The discovery of naturally occurring long-lived isomeric states (t{sub 1/2}>10{sup 8} yr) in the neutron-deficient isotopes {sup 211,213,217,218}Th[A. Marinov et al., Phys. Rev. C 76, 021303(R) (2007)] was reexamined using accelerator mass spectrometry (AMS). Because AMS does not suffer from molecular isobaric background in the detection system, it is an extremely sensitive technique. Despite our up to two orders of magnitude higher sensitivity we cannot confirm the discoveries of neutron-deficient thorium isotopes and provide upper limits for their abundances.

Lachner, J.; Dillmann, I.; Faestermann, T.; Korschinek, G.; Poutivtsev, M.; Rugel, G. [Physik Department E12 and E15, Technische Universitaet Muenchen, D-85748 Garching (Germany)

2008-12-15T23:59:59.000Z

58

Search for long-lived isomeric states in neutron-deficient thorium isotopes  

E-Print Network [OSTI]

The discovery of naturally occurring long-lived isomeric states (t_1/2 > 10^8 yr) in the neutron-deficient isotopes 211,213,217,218Th [A. Marinov et al., Phys. Rev. C 76, 021303(R) (2007)] was reexamined using accelerator mass spectrometry (AMS). Because AMS does not suffer from molecular isobaric background in the detection system, it is an extremely sensitive technique. Despite our up to two orders of magnitude higher sensitivity we cannot confirm the discoveries of neutron-deficient thorium isotopes and provide upper limits for their abundances.

J. Lachner; I. Dillmann; T. Faestermann; G. Korschinek; M. Poutivtsev; G. Rugel

2009-07-01T23:59:59.000Z

59

Z=50 shell gap near $^{100}$Sn from intermediate-energy Coulomb excitations in even-mass $^{106--112}$Sn isotopes  

E-Print Network [OSTI]

Rare isotope beams of neutron-deficient $^{106,108,110}$Sn nuclei from the fragmentation of $^{124}$Xe were employed in an intermediate-energy Coulomb excitation experiment yielding $B(E2, 0^+_1 \\to 2^+_1)$ transition strengths. The results indicate that these $B(E2,0^+_1 \\to 2^+_1)$ values are much larger than predicted by current state-of-the-art shell model calculations. This discrepancy can be explained if protons from within the Z = 50 shell are contributing to the structure of low-energy excited states in this region. Such contributions imply a breaking of the doubly-magic $^{100}$Sn core in the light Sn isotopes.

C. Vaman; C. Andreoiu; D. Bazin; A. Becerril; A. Brown; C. M. Campbell; A. Chester; J. M. Cook; D. C. Dinca; A. Gade; D. Galaviz; T. Glasmacher; M. Hjorth-Jensen; M. Horoi; D. Miller; V. Moeller; W. F. Mueller; A. Schiller; K. Starosta; A. Stolz; J. R. Terry; A. Volya; V. Zelevinsky; H. Zwahlen

2006-12-08T23:59:59.000Z

60

from Isotope Production Facility  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Cancer-fighting treatment gets boost from Isotope Production Facility April 13, 2012 Isotope Production Facility produces cancer-fighting actinium 2:32 Isotope cancer treatment...

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Positive and inverse isotope effect on superconductivity  

E-Print Network [OSTI]

This article improves the BCS theory to include the inverse isotope effect on superconductivity. An affective model can be deduced from the model including electron-phonon interactions, and the phonon-induced attraction is simply and clearly explained on the electron Green function. The focus of this work is on how the positive or inverse isotope effect occurs in superconductors.

Tian De Cao

2009-09-04T23:59:59.000Z

62

Physics with isotopically controlled semiconductors  

SciTech Connect (OSTI)

This paper is based on a tutorial presentation at the International Conference on Defects in Semiconductors (ICDS-25) held in Saint Petersburg, Russia in July 2009. The tutorial focused on a review of recent research involving isotopically controlled semiconductors. Studies with isotopically enriched semiconductor structures experienced a dramatic expansion at the end of the Cold War when significant quantities of enriched isotopes of elements forming semiconductors became available for worldwide collaborations. Isotopes of an element differ in nuclear mass, may have different nuclear spins and undergo different nuclear reactions. Among the latter, the capture of thermal neutrons which can lead to neutron transmutation doping, is the most prominent effect for semiconductors. Experimental and theoretical research exploiting the differences in all the properties has been conducted and will be illustrated with selected examples.

Haller, E. E., E-mail: eehaller@lbl.gov [University of California at Berkeley, Department of Materials Science and Engineering (United States)

2010-07-15T23:59:59.000Z

63

Isotopic Analysis-Fluid At Long Valley Caldera Geothermal Area...  

Open Energy Info (EERE)

1971) prior to analysis by mass spectrometry. Water samples were analyzed for their oxygen isotope ratios using the carbon dioxide-equilibration method. Waters analyzed from the...

64

Kinetics of the Reaction of the Heaviest Hydrogen Atom with H2, the 4He? + H2 -> 4He?? + H Reaction: Experiments, Accurate Quantal Calculations, and Variational Transition State Theory, including Kinetic Isotope Effects for a Factor of 36.1 in Isotopic Mass  

SciTech Connect (OSTI)

The neutral muonic helium atom {sup 4}He{mu}, in which one of the electrons of He is replaced by a negative muon, may be effectively regarded as the heaviest isotope of the hydrogen atom, with a mass of 4.115 amu. We report details of the first muon spin rotation ({mu}SR) measurements of the chemical reaction rate constant of {sup 4}He{mu} with molecular hydrogen, {sup 4}He{mu} + H{sub 2} {yields} {sup 4}He{mu}H + H, at temperatures of 295.5, 405, and 500 K, as well as a {mu}SR measurement of the hyperfine coupling constant of muonic He at high pressures. The experimental rate constants, k{sub He{mu}}, are compared with the predictions of accurate quantum mechanical (QM) dynamics calculations carried out on a well converged Born-Huang (BH) potential energy surface, based on complete configuration interaction calculations and including a Born-Oppenheimer diagonal correction. At the two highest measured temperatures the agreement between the quantum theory and experiment is good to excellent, well within experimental uncertainties that include an estimate of possible systematic error, but at 295.5 K the quantum calculations for k{sub He{mu}} are below the experimental value by 2.1 times the experimental uncertainty estimates. Possible reasons for this discrepancy are discussed. Variational transition state theory calculations with multidimensional tunneling have also been carried out for k{sub He{mu}} on the BH surface, and they agree with the accurate QM rate constants to within 30% over a wider temperature range of 200-1000 K. Comparisons between theory and experiment are also presented for the rate constants for both the D + H{sub 2} and Mu + H{sub 2} reactions in a novel study of kinetic isotope effects for the H + H{sub 2} reactions over a factor of 36.1 in isotopic mass of the atomic reactant.

Fleming, Donald G.; Arseneau, Donald J.; Sukhorukov, Oleksandr; Brewer, Jess H.; Mielke, Steven L.; Truhlar, Donald G.; Schatz, George C.; Garrett, Bruce C.; Peterson, Kirk A.

2011-11-14T23:59:59.000Z

65

{sup 99}Tc bioassay: A direct comparison of liquid scintillation radiation detection and ICP-MS mass detection of the {sup 99}Tc isotope  

SciTech Connect (OSTI)

A means of analyzing {sup 99}Tc in urine by inductively coupled plasma mass spectrometry (ICP-MS) has been developed. Historically, {sup 99}Tc analysis was based on the radiometric detection of the 293 keV E{sub Max.} beta decay product by liquid scintillation or gas flow proportional counting. A separation scheme for {sup 99}Tc detection by ICP-MS is given and is proven to be a sensitive and robust analytical alternative. A comparison of methods using radiometric and mass quantitation of {sup 99}Tc has been conducted in water, artificial urine, and real urine matrices at activity levels between 700 and 2,200 dpm/L. Liquid scintillation results based on an external standard manual quench correction and an automatic quench curve correction method are compared with results obtained by ICP-MS. Each method produced accurate results; however, the precision of the ICP-MS results is superior to that of liquid scintillation results.

Lewis, L.A. [Lockheed Martin Energy Systems, Inc., Oak Ridge, TN (United States). Analytical Services Organization; Schweitzer, G.K. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Chemistry

1998-12-31T23:59:59.000Z

66

isotopic ratio | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

isotopic ratio isotopic ratio Leads No leads are available at this time. Magnesium behavior and structural defects in Mg+ ion implanted silicon carbide. Abstract: As a candidate...

67

UV-frequency metrology on CO (a{sup 3}{Pi}): Isotope effects and sensitivity to a variation of the proton-to-electron mass ratio  

SciTech Connect (OSTI)

UV-frequency metrology has been performed on the a{sup 3}{Pi} - X{sup 1}{Sigma}{sup +} (0,0) band of various isotopologues of CO using a frequency-quadrupled injection-seeded narrow-band pulsed titanium:sapphire laser referenced to a frequency comb laser. The band origin is determined with an accuracy of 5 MHz ({delta}{nu}/{nu}=3x10{sup -9}), while the energy differences between rotational levels in the a{sup 3}{Pi} state are determined with an accuracy of 500 kHz. From these measurements, in combination with previously published radio-frequency and microwave data, a set of molecular constants is obtained that describes the level structure of the a{sup 3}{Pi} state of {sup 12}C{sup 16}O and {sup 13}C{sup 16}O with improved accuracy. Transitions in the different isotopologues are well reproduced by scaling the molecular constants of {sup 12}C{sup 16}O via the common mass-scaling rules. Only the value of the band origin could not be scaled, indicative of a breakdown of the Born-Oppenheimer approximation. Our analysis confirms the extreme sensitivity of two-photon microwave transitions between nearly degenerate rotational levels of different {Omega} manifolds for probing a possible variation of the proton-to-electron mass ratio, {mu}=m{sub p}/m{sub e}, on a laboratory time scale.

Nijs, Adrian J. de; Salumbides, Edcel J.; Eikema, Kjeld S. E.; Ubachs, Wim; Bethlem, Hendrick L. [Institute for Lasers, Life and Biophotonics Amsterdam, VU University, De Boelelaan 1081, NL-1081 HV Amsterdam (Netherlands)

2011-11-15T23:59:59.000Z

68

Standard test method for analysis of urine for uranium-235 and uranium-238 isotopes by inductively coupled plasma-mass spectrometry  

E-Print Network [OSTI]

1.1 This test method covers the determination of the concentration of uranium-235 and uranium-238 in urine using Inductively Coupled Plasma-Mass Spectrometry. This test method can be used to support uranium facility bioassay programs. 1.2 This method detection limits for 235U and 238U are 6 ng/L. To meet the requirements of ANSI N13.30, the minimum detectable activity (MDA) of each radionuclide measured must be at least 0.1 pCi/L (0.0037 Bq/L). The MDA translates to 47 ng/L for 235U and 300 ng/L for 238U. Uranium– 234 cannot be determined at the MDA with this test method because of its low mass concentration level equivalent to 0.1 pCi/L. 1.3 The digestion and anion separation of urine may not be necessary when uranium concentrations of more than 100 ng/L are present. 1.4 Units—The values stated in picoCurie per liter units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. 1....

American Society for Testing and Materials. Philadelphia

2010-01-01T23:59:59.000Z

69

Isotope-labeled immunoassays without radiation waste  

E-Print Network [OSTI]

of California, Davis, CA 95616; and Center for Accelerator Mass Spectrometry, Lawrence Livermore National, such as liquid scintillation counting (LSC) and autoradiography, use the radiation generated in the isotope in areas such as environmental monitoring and food analysis. Accelerator mass spectrometry (AMS) developed

Hammock, Bruce D.

70

Triple Oxygen Isotope Measurement of Nitrate to Analyze Impact of Aircraft Emissions  

E-Print Network [OSTI]

P. ; Craig, H. Atmospheric oxygen: isotopic composition andM.H. 1986. A non-mass-dependent oxygen isotope effect in theof ozone from molecular oxygen: the role of symmetry in

Chan, Sharleen

71

Stable isotope studies  

SciTech Connect (OSTI)

The research has been in four general areas: (1) correlation of isotope effects with molecular forces and molecular structures, (2) correlation of zero-point energy and its isotope effects with molecular structure and molecular forces, (3) vapor pressure isotope effects, and (4) fractionation of stable isotopes. 73 refs, 38 figs, 29 tabs.

Ishida, T.

1992-01-01T23:59:59.000Z

72

Isotope Science and Production  

E-Print Network [OSTI]

of Energy National Isotope Program http://www.nuclear.energy.gov/isotopes/nelsotopes2a.html Isotopes for Environmental Science Isotopes produced at Los Alamos National Laboratory are used as environmental tracers change and its effects. Los Alamos National Laboratory can produce Si-32 needed for oceanographic tracing

73

Method for enriching a middle isotope using vibration-vibration pumping  

DOE Patents [OSTI]

Method for producing isotopically enriched material by vibration-vibration excitation of gaseous molecules wherein a middle mass isotope of an isotopic mixture including lighter and heavier mass isotopes preferentially populates a higher vibrational mode and chemically reacts to provide a product in which it is enriched. The method can be used for vibration-vibration enrichment of .sup.17 O in a CO reactant mixture.

Rich, Joseph W. (East Aurora, NY); Homicz, Gregory F. (Getzville, NY); Bergman, Richard C. (Corfu, NY)

1989-01-01T23:59:59.000Z

74

Magnesium Isotopes in Halo Stars  

E-Print Network [OSTI]

We have determined Mg isotope ratios in halo field dwarfs and giants in the globular cluster M71 based on high S/N high spectral resolution (R = 10$^5$) Keck HIRES spectra. Unlike previous claims of an important contribution from intermediate-mass AGB stars to the Galactic halo, we find that our $^{26}$Mg/$^{24}$Mg ratios can be explained by massive stars.

Jorge Melendez; Judith G. Cohen

2007-08-29T23:59:59.000Z

75

Analysis of hydrogen isotope mixtures  

DOE Patents [OSTI]

An apparatus and method for determining the concentrations of hydrogen isotopes in a sample. Hydrogen in the sample is separated from other elements using a filter selectively permeable to hydrogen. Then the hydrogen is condensed onto a cold finger or cryopump. The cold finger is rotated as pulsed laser energy vaporizes a portion of the condensed hydrogen, forming a packet of molecular hydrogen. The desorbed hydrogen is ionized and admitted into a mass spectrometer for analysis.

Villa-Aleman, Eliel (Aiken, SC)

1994-01-01T23:59:59.000Z

76

Method and apparatus for storing hydrogen isotopes. [stored as uranium hydride in a block of copper  

DOE Patents [OSTI]

An improved method and apparatus for storing isotopes of hydrogen (especially tritium) are provided. The hydrogen gas is stored as hydrides of material (for example uranium) within boreholes in a block of copper. The mass of the block is critically important to the operation, as is the selection of copper, because no cooling pipes are used. Because no cooling pipes are used, there can be no failure due to cooling pipes. And because copper is used instead of stainless steel, a significantly higher temperature can be reached before the eutectic formation of uranium with copper occurs, (the eutectic of uranium with the iron in stainless steel forms at a significantly lower temperature).

McMullen, J.W.; Wheeler, M.G.; Cullingford, H.S.; Sherman, R.H.

1982-08-10T23:59:59.000Z

77

THE ISOTOPES OF AMERICIUM  

E-Print Network [OSTI]

spectrographic analysis of the americium samples. It is a48 J'---_I" THE ISOTOPES OF AMERICIUM K. Street, Jr. , A.Elements THE ISOTOPES OF AMERICIUM K. Street, Jr. , A.

Street, K.; Ghiroso, A.; Seaborg, G.T.

2008-01-01T23:59:59.000Z

78

Measuring the Isotopic Composition of Solar Wind Noble Gases  

E-Print Network [OSTI]

noble gases. #12;Exploring the Solar Wind94 Light solar wind noble gases were directly measured by mass of the light gases are known to vary with energy, so none of these provided solar isotopic and elemental5 Measuring the Isotopic Composition of Solar Wind Noble Gases Alex Meshik, Charles Hohenberg, Olga

79

Nitrogen isotope dynamics of the Cariaco Basin, Venezuela Robert C. Thunell,1  

E-Print Network [OSTI]

Nitrogen isotope dynamics of the Cariaco Basin, Venezuela Robert C. Thunell,1 Daniel M. Sigman,2 of Venezuela. Water column denitrification occurring in the basin has only a very small isotopic imprint-Karger, Y. Astor, and R. Varela (2004), Nitrogen isotope dynamics of the Cariaco Basin, Venezuela, Global

Sigman, Daniel M.

80

A direct and rapid leaf water extraction method for isotopic analysis  

E-Print Network [OSTI]

Department of Environmental Sciences and Energy Research, Weizmann Institute of Science, Rehovot, Israel for isotopic analysis via pyrolysis gas chromatography isotope ratio mass spectrometry (PYR/GC/IRMS). The new-scale studies that require high-throughput leaf water isotopic analysis. Copyright # 2008 John Wiley & Sons, Ltd

Yakir, Dan

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Using phylogenetic probes for quantification of stable isotope labeling and microbial community analysis  

DOE Patents [OSTI]

Herein is described methods for a high-sensitivity means to measure the incorporation of stable isotope labeled substrates into RNA following stable isotope probing experiments (SIP). RNA is hybridized to a set of probes such as phylogenetic microarrays and isotope incorporation is quantified such as by secondary ion mass spectrometer imaging (NanoSIMS).

Brodie, Eoin L; DeSantis, Todd Z; Karaoz, Ulas; Andersen, Gary L

2014-12-09T23:59:59.000Z

82

argon isotope analysis: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

1.1 This is a quantitative test method applicable to determining the mass percent of uranium isotopes in uranium hexafluoride (UF6) samples with 235U concentrations between 0.1...

83

Radiation Sources External Beam and Isotopes  

E-Print Network [OSTI]

Radiation Sources External Beam and Isotopes J. Daniel Bourland, PhD Professor Department of Radiation Oncology Departments of Physics and Biomedical Engineering Wake Forest School of Medicine Winston Radiation · Photons: electromagnetic radiation, no mass, E = h · X rays: origins are from atomic energy

84

Naturally Occurring Radioactive Materials in Cargo at US Borders  

SciTech Connect (OSTI)

In the U.S. and other countries, large numbers of vehicles pass through border crossings each day. The illicit movement of radioactive sources is a concern that has resulted in the installation of radiation detection and identification instruments at border crossing points. This activity is judged to be necessary because of the possibility of an act of terrorism involving a radioactive source that may include any number of dangerous radionuclides. The problem of detecting, identifying, and interdicting illicit radioactive sources is complicated by the fact that many materials present in cargo are somewhat radioactive. Some cargo contains naturally occurring radioactive material or technologically-enhanced naturally occurring radioactive material that may trigger radiation portal monitor alarms. Man-made radioactive sources, especially medical isotopes, are also frequently observed and produce alarms. Such nuisance alarms can be an operational limiting factor for screening of cargo at border crossings. Information about the nature of the radioactive materials in cargo that can interfere with the detection of radionuclides of concern is necessary. This paper provides such information for North American cargo, but the information may also be of use to border control officials in other countries. (PIET-43741-TM-361)

Kouzes, Richard T.; Ely, James H.; Evans, John C.; Hensley, Walter K.; Lepel, Elwood A.; McDonald, Joseph C.; Schweppe, John E.; Siciliano, Edward R.; Strom, Daniel J.; Woodring, Mitchell L.

2006-01-01T23:59:59.000Z

85

Hybrid isotope separation scheme  

DOE Patents [OSTI]

A method is described for yielding selectively a desired enrichment in a specific isotope including the steps of inputting into a spinning chamber a gas from which a scavenger, radiating the gas with a wave length or frequency characteristic of the absorption of a particular isotope of the atomic or molecular gas, thereby inducing a photochemical reaction between the scavenger, and collecting the specific isotope-containing chemical by using a recombination surface or by a scooping apparatus. 2 figures.

Maya, J.

1991-06-18T23:59:59.000Z

86

Hybrid isotope separation scheme  

DOE Patents [OSTI]

A method of yielding selectively a desired enrichment in a specific isotope including the steps of inputting into a spinning chamber a gas from which a scavenger, radiating the gas with a wave length or frequency characteristic of the absorption of a particular isotope of the atomic or molecular gas, thereby inducing a photochemical reaction between the scavenger, and collecting the specific isotope-containing chemical by using a recombination surface or by a scooping apparatus.

Maya, Jakob (Brookline, MA)

1991-01-01T23:59:59.000Z

87

Laser isotope separation by multiple photon absorption  

DOE Patents [OSTI]

Multiple photon absorption from an intense beam of infrared laser light may be used to induce selective chemical reactions in molecular species which result in isotope separation or enrichment. The molecular species must have a sufficient density of vibrational states in its vibrational manifold that, is the presence of sufficiently intense infrared laser light tuned to selectively excite only those molecules containing a particular isotope, multiple photon absorption can occur. By this technique, for example, intense CO[sub 2] laser light may be used to highly enrich [sup 34]S in natural SF[sub 6] and [sup 11]B in natural BCl[sub 3]. 8 figs.

Robinson, C.P.; Rockwood, S.D.; Jensen, R.J.; Lyman, J.L.; Aldridge, J.P. III.

1987-04-07T23:59:59.000Z

88

Laser isotope separation by multiple photon absorption  

DOE Patents [OSTI]

Multiple photon absorption from an intense beam of infrared laser light may be used to induce selective chemical reactions in molecular species which result in isotope separation or enrichment. The molecular species must have a sufficient density of vibrational states in its vibrational manifold that, is the presence of sufficiently intense infrared laser light tuned to selectively excite only those molecules containing a particular isotope, multiple photon absorption can occur. By this technique, for example, intense CO.sub.2 laser light may be used to highly enrich .sup.34 S in natural SF.sub.6 and .sup.11 B in natural BCl.sub.3.

Robinson, C. Paul (Los Alamos, NM); Rockwood, Stephen D. (Los Alamos, NM); Jensen, Reed J. (Los Alamos, NM); Lyman, John L. (Los Alamos, NM); Aldridge, III, Jack P. (Los Alamos, NM)

1987-01-01T23:59:59.000Z

89

Stable isotope enrichment  

SciTech Connect (OSTI)

Brian Egle is working to increase the nation's capacity to produce stable isotopes for use including medicine, industry and national security.

Egle, Brian

2014-07-14T23:59:59.000Z

90

EMSL - isotopic ratio  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

isotopic-ratio en Magnesium behavior and structural defects in Mg+ ion implanted silicon carbide. http:www.emsl.pnl.govemslwebpublicationsmagnesium-behavior-and-structural-def...

91

Stable isotope enrichment  

ScienceCinema (OSTI)

Brian Egle is working to increase the nation's capacity to produce stable isotopes for use including medicine, industry and national security.

Egle, Brian

2014-07-15T23:59:59.000Z

92

Discovery of the Tungsten Isotopes  

E-Print Network [OSTI]

Thirty-five tungsten isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

A. Fritsch; J. Q. Ginepro; M. Heim; A. Schuh; A. Shore; M. Thoennessen

2009-03-25T23:59:59.000Z

93

Discovery of the Tin Isotopes  

E-Print Network [OSTI]

Thirty-eight tin isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

S. Amos; M. Thoennessen

2010-09-08T23:59:59.000Z

94

Discovery of the tungsten isotopes  

SciTech Connect (OSTI)

Thirty-five tungsten isotopes have been observed so far and the discovery of these isotopes is discussed here. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

Fritsch, A.; Ginepro, J.Q.; Heim, M.; Schuh, A.; Shore, A. [National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Thoennessen, M. [National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States)], E-mail: thoennessen@nscl.msu.edu

2010-05-15T23:59:59.000Z

95

Discovery of the Tungsten Isotopes  

E-Print Network [OSTI]

Thirty-five tungsten isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

Fritsch, A; Heim, M; Schuh, A; Shore, A; Thoennessen, M

2009-01-01T23:59:59.000Z

96

CAN GALACTIC CHEMICAL EVOLUTION EXPLAIN THE OXYGEN ISOTOPIC VARIATIONS IN THE SOLAR SYSTEM?  

SciTech Connect (OSTI)

A number of objects in primitive meteorites have oxygen isotopic compositions that place them on a distinct, mass-independent fractionation line with a slope of one on a three-isotope plot. The most popular model for describing how this fractionation arose assumes that CO self-shielding produced {sup 16}O-rich CO and {sup 16}O-poor H{sub 2}O, where the H{sub 2}O subsequently combined with interstellar dust to form relatively {sup 16}O-poor solids within the solar nebula. Another model for creating the different reservoirs of {sup 16}O-rich gas and {sup 16}O-poor solids suggests that these reservoirs were produced by Galactic chemical evolution (GCE) if the solar system dust component was somewhat younger than the gas component and both components were lying on the line of slope one in the O three-isotope plot. We argue that GCE is not the cause of mass-independent fractionation of the oxygen isotopes in the solar system. The GCE scenario is in contradiction with observations of the {sup 18}O/{sup 17}O ratios in nearby molecular clouds and young stellar objects. It is very unlikely for GCE to produce a line of slope one when considering the effect of incomplete mixing of stellar ejecta in the interstellar medium. Furthermore, the assumption that the solar system dust was younger than the gas requires unusual timescales or the existence of an important stardust component that is not theoretically expected to occur nor has been identified to date.

Lugaro, Maria [Monash Centre for Astrophysics (MoCA), Building 28, Monash University, Clayton, VIC 3800 (Australia); Liffman, Kurt [CSIRO/MSE, P.O. Box 56, Highett, VIC 3190 (Australia); Ireland, Trevor R. [Planetary Science Institute and Research School of Earth Sciences, Australian National University, Canberra, ACT 0200 (Australia); Maddison, Sarah T., E-mail: maria.lugaro@monash.edu [Centre for Astrophysics and Supercomputing, Swinburne University, H39, P.O. Box 218, Hawthorn, VIC 3122 (Australia)

2012-11-01T23:59:59.000Z

97

Magnesium Isotopes in Metal-Poor Dwarfs, the Rise of AGB Stars and the Formation Timescale of the Galactic Halo  

E-Print Network [OSTI]

We have determined magnesium isotopic ratios (^{25,26}Mg/Mg) in metal-poor (-2.6 [Fe/H] -1.3) halo dwarfs employing high S/N (90-280) high spectral resolution (R = 10^5) Keck HIRES spectra. Unlike previous claims of an important contribution from intermediate-mass AGB stars at low metallicities, we find that the rise of the AGB contribution in the Galactic halo did not occur until intermediate metallicities ([Fe/H] ~> -1.5).

Jorge Melendez; Judith G. Cohen

2007-02-24T23:59:59.000Z

98

Hyperfiltration-induced fractionation of lithium isotopes in geologic systems. Progress report, April 1, 1991--December 1, 1991  

SciTech Connect (OSTI)

Effective modeling of hyperfiltration-induced fractionation of lithium isotopes is hindered by a lack of data on aqueous diffusion coefficients of {sup 6}Li{sup +} and {sup 7}Li{sup +}. Several experiments were conducted this past year on yielded a value for the ratio of diffusion coefficients between {sup D6}Li+Cl{minus}/{sup D7}Li+Cl{minus}. A 0.9450 M LiCl solution was placed within sealed dialysis tubing and osmoted against a kilogram of deionized water at 22C. Osmotic equilibrium occurred at 143 minutes, and the ratio of {omega}{sup 6}Li{sup +}Cl{minus}/{omega}{sup 7}Li+Cl{minus} was measured to be 1.011. Because this experimental value is close to the square root of the mass ratio between {sup 7}LiCl and {sup 6}LiCl (1.012), Graham`s Law may be a convenient way to calculate such ratios for aqueous diffusion coefficients of individual isotopic components. In evolution of this closed-system osmotic cell as a function of time, Li isotopic ratios of beaker and bag solutions exhibit a minimum and a maximum before the {sup 6}Li/{sup 7}Li ratios of both solutions assume the inevitable asymptotic approach toward isotopic equilibrium. Max difference in {sup 6}Li/{sup 7}Li ratio between beaker and bag solution was 0.00156 {plus_minus} 0.00015.

Fritz, S.J.

1992-01-01T23:59:59.000Z

99

Characterization of naturally occurring porous media  

E-Print Network [OSTI]

characteristics of natural occur- ring porous media, The gR /K dimensionless ratio is related to the minimum water saturation in the reverse manner as is permeability. REFERENCES Wyllie, M. R. J. and M. B. Spangler: Application of Electrical Resistivity...: Resistivity of Brine-Saturated Sands in Relation to Pore Seometry. Cornell, D. snd D. L. Kstz: Flow of Sases through Consolidated Porous Media. Industrial and En ineeri hemietr (October 1953) Vo . 5, p. 21 5. Leverett, N, C. : Capillary Behavior...

Riley, Robert Daniel

1965-01-01T23:59:59.000Z

100

Time-of-Flight Mass Measurements of Exotic Nuclei  

SciTech Connect (OSTI)

Atomic masses play an important role in nuclear physics and astrophysics. The need of experimental mass values for unstable nuclides has triggered the development of a wide range of mass measurement techniques, with devices installed at many laboratories around the world. We have implemented a time-of-flight magnetic-rigidity (TOF-B ) technique at the National Superconducting Cyclotron Laboratory (NSCL) that includes a position measurement for magnetic rigidity corrections and uses the A1900 separator and the S800 spectrograph. We performed a successful first experiment measuring masses of neutron-rich isotopes in the region of Z 20 30, important for calculations of processes occurring in the crust of accreting neutron stars. The masses of 16 nuclei were determined, for 61V, 63Cr, 66Mn, and 74Ni for the first time, with atomic mass excesses of 30.510(890) MeV, 35.280(650) MeV, 36.900(790) MeV, and 49.210(990) MeV, respectively. The mass resolution achieved was 1.8 10 4.

Matos, M. [Michigan State Univ./JINA/Louisiana State University; Estrade, A. [Michigan State Univ./JINA/LSU/Saint Mary's Univ./GSI Darmstadt, GE; Schatz, H. [Michigan State Univ./JINA; Bazin, D. [Michigan State University, East Lansing; Famiano, M. [Western Michigan University, Kalamazoo; Gade, A. [Michigan State University, East Lansing; George, S. [NSCL, Michigan State University, East Lansing; Lynch, W. G. [NSCL, Michigan State Univ./JINA; Meisel, Z. [NSCL, Michigan State Univ./JINA; Portillo, M. [NSCL, Michigan State University, East Lansing; Rogers, A. [NSCL, Michigan State Univ./JINA; Shapira, Dan [ORNL; Stolz, A. [Michigan State University, East Lansing; Wallace, M. [Los Alamos National Laboratory (LANL); Yurkon, J. [NSCL, Michigan State University, East Lansing

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Uncertainty analysis of densities and isotopics: Handling correlations  

SciTech Connect (OSTI)

This paper discusses two cases of correlated parameters in uncertainty analyses: (1) the case of measured mass, density, and volume or spatial dimension correlations; and (2) the case of measured material isotopics, where increasing one atom fraction must cause the others to decrease. In the first case, an equation is derived that has a term due to uncertain density, a term due to uncertain dimensions, and a term due to the correlation between density and dimensions. In a numerical test problem, this equation gives the same result as the standard equation that treats mass and dimensions independently. In the case of isotopics, an equation is derived relating the uncertainty due to uncertain isotopic fractions to the sensitivities to isotopic densities, which are easier to calculate. The equation is verified in a test problem. (authors)

Favorite, J. A.; Armstrong, J. C. [X-Computational Physics Division, Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States); Burr, T. [Computer, Computational, and Statistical Sciences Division, Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States)

2013-07-01T23:59:59.000Z

102

Nipah virus entry can occur by macropinocytosis  

SciTech Connect (OSTI)

Nipah virus (NiV) is a zoonotic biosafety level 4 paramyxovirus that emerged recently in Asia with high mortality in man. NiV is a member, with Hendra virus (HeV), of the Henipavirus genus in the Paramyxoviridae family. Although NiV entry, like that of other paramyxoviruses, is believed to occur via pH-independent fusion with the host cell's plasma membrane we present evidence that entry can occur by an endocytic pathway. The NiV receptor ephrinB2 has receptor kinase activity and we find that ephrinB2's cytoplasmic domain is required for entry but is dispensable for post-entry viral spread. The mutation of a single tyrosine residue (Y304F) in ephrinB2's cytoplasmic tail abrogates NiV entry. Moreover, our results show that NiV entry is inhibited by constructions and drugs specific for the endocytic pathway of macropinocytosis. Our findings could potentially permit the rapid development of novel low-cost antiviral treatments not only for NiV but also HeV.

Pernet, Olivier; Pohl, Christine; Ainouze, Michelle; Kweder, Hasan [Molecular Basis of Paramyxovirus Entry, INSERM U758 Virologie Humaine IFR 128 BioSciences Gerland-Lyon Sud, 21 Avenue Tony Garnier, 69365 Lyon Cedex 07 (France); Buckland, Robin, E-mail: robin.buckland@inserm.f [Molecular Basis of Paramyxovirus Entry, INSERM U758 Virologie Humaine IFR 128 BioSciences Gerland-Lyon Sud, 21 Avenue Tony Garnier, 69365 Lyon Cedex 07 (France)

2009-12-20T23:59:59.000Z

103

Isotopic Composition of Solar Wind Calcium: First in Situ Measurement by CELIAS/MTOF on Board SOHO  

E-Print Network [OSTI]

We present first results on the Ca isotopic abundances derived from the high resolution Mass Time-of-Flight (MTOF) spectrometer of the charge, element, and isotope analysis system (CELIAS) experiment on board the Solar and Heliospheric Observatory (SOHO). We obtain isotopic ratios 40Ca/42Ca = (128+-47) and 40Ca/44Ca = (50+-8), consistent with terrestrial values. This is the first in situ determination of the solar wind calcium isotopic composition and is important for studies of stellar modeling and solar system formation since the present-day solar Ca isotopic abundances are unchanged from their original isotopic composition in the solar nebula.

R. Kallenbach; F. M. Ipavich; P. Bochsler; S. Hefti; P. Wurz; M. R. Aellig; A. B. Galvin; J. Geiss; F. Gliem; G. Gloeckler; H. Grunwaldt; M. Hilchenbach; D. Hovestadt; B. Klecker

1998-02-07T23:59:59.000Z

104

Introduction to naturally occurring radioactive material  

SciTech Connect (OSTI)

Naturally occurring radioactive material (NORM) is everywhere; we are exposed to it every day. It is found in our bodies, the food we eat, the places where we live and work, and in products we use. We are also bathed in a sea of natural radiation coming from the sun and deep space. Living systems have adapted to these levels of radiation and radioactivity. But some industrial practices involving natural resources concentrate these radionuclides to a degree that they may pose risk to humans and the environment if they are not controlled. Other activities, such as flying at high altitudes, expose us to elevated levels of NORM. This session will concentrate on diffuse sources of technologically-enhanced (TE) NORM, which are generally large-volume, low-activity waste streams produced by industries such as mineral mining, ore benefication, production of phosphate Fertilizers, water treatment and purification, and oil and gas production. The majority of radionuclides in TENORM are found in the uranium and thorium decay chains. Radium and its subsequent decay products (radon) are the principal radionuclides used in characterizing the redistribution of TENORM in the environment by human activity. We will briefly review other radionuclides occurring in nature (potassium and rubidium) that contribute primarily to background doses. TENORM is found in many waste streams; for example, scrap metal, sludges, slags, fluids, and is being discovered in industries traditionally not thought of as affected by radionuclide contamination. Not only the forms and volumes, but the levels of radioactivity in TENORM vary. Current discussions about the validity of the linear no dose threshold theory are central to the TENORM issue. TENORM is not regulated by the Atomic Energy Act or other Federal regulations. Control and regulation of TENORM is not consistent from industry to industry nor from state to state. Proposed regulations are moving from concentration-based standards to dose-based standards. So when is TENORM a problem? Where is it a problem? That depends on when, where, and whom you talk to! We will start by reviewing background radioactivity, then we will proceed to the geology, mobility, and variability of these radionuclides. We will then review some of the industrial sectors affected by TENORM, followed by a brief discussion on regulatory aspects of the issue.

Egidi, P.

1997-08-01T23:59:59.000Z

105

The effects of post-condensation exchange on the isotopic composition of water in1 the atmosphere2  

E-Print Network [OSTI]

of the water vapor and the amount of previous2 rainfall from the air mass as the dominant controls on the isotopic composition of3 atmospheric moisture. These formed the basis of the Rayleigh distillation model4 16 O, causing the progressive8 isotopic depletion of the air mass at it loses moisture. In its most

Field, Robert

106

Transportation of medical isotopes  

SciTech Connect (OSTI)

A Draft Technical Information Document (HNF-1855) is being prepared to evaluate proposed interim tritium and medical isotope production at the Fast Flux Test Facility (FFTF). This assessment examines the potential health and safety impacts of transportation operations associated with the production of medical isotopes. Incident-free and accidental impacts are assessed using bounding source terms for the shipment of nonradiological target materials to the Hanford Site, the shipment of irradiated targets from the FFTF to the 325 Building, and the shipment of medical isotope products from the 325 Building to medical distributors. The health and safety consequences to workers and the public from the incident-free transportation of targets and isotope products would be within acceptable levels. For transportation accidents, risks to works and the public also would be within acceptable levels. This assessment is based on best information available at this time. As the medical isotope program matures, this analysis will be revised, if necessary, to support development of a final revision to the Technical Information Document.

Nielsen, D.L.

1997-11-19T23:59:59.000Z

107

GENERATION OF RADIOXENON ISOTOPES  

SciTech Connect (OSTI)

With the continued population of the International Monitoring System (IMS) network and the certification of radioxenon laboratory systems it has become necessary to calibrate and test these systems using as many of the radioxenon isotopes as possible. Several very promising techniques have been explored recently that allow for convenient production of Xe-133, Xe-131m, the short-lived isotope Xe-135, and even the difficult to obtain Xe-133m. IMS national and international laboratories have traditionally obtained Xe-133 from medical isotope suppliers. The activity of these medical dose samples is extremely high (~ 740 MBq) and requires very careful fume hood work to dilute down to appropriate levels (~ 10 Bq). By waiting for 10 or more half-lives it is possible to reduce the handling regimen considerably, while also obtaining a strong Xe-131m signature due to its longer half-life (11.9 days). The short-lived isotope Xe-135 (9.14 hrs) and the longer lived parent nuclide Xe-133m (2.2 day half-life) are never present in these samples. To obtain these isotopes another source or technique is required. This paper will discuss the two techniques developed and implemented at Pacific Northwest National Lab (PNNL) and show the results obtained from each technique. The first is an in-house method that allows for on demand production of two of these isotopes, Xe-133 and Xe-135, using HEU and a modest flux neutron source. The second method uses a research reactor at the Pullman campus of Washington State University to produce Xe-133, Xe-133m and Xe-135.

McIntyre, Justin I.; Pratt, Sharon L.; Bowyer, Ted W.; Cooper, Matthew W.; Hayes, James C.; Heimbigner, Tom R.; Hubbard, Charles W.; Miley, Harry S.; Ripplinger, Mike D.

2008-09-23T23:59:59.000Z

108

Isotopic studies of Yucca Mountain soil fluids and carbonate pedogenesis  

SciTech Connect (OSTI)

Secondary carbonates occurring within the soils, faults, and subsurface fractures of Yucca Mountain contain some of the best available records of paleoclimate and palehydrology for the potential radioactive waste repository site. This article discusses conceptual and analytical advances being made with regard to the interpretation of stable isotope data from pedogenic carbonates, specifically related to the {sup 13}C content of soil CO{sub 2}, CaCO{sub 3}, precipitation mechanisms, and isotopic fractionations between parent fluids and precipitating carbonates. The {sup 13}C content of soil carbon dioxide from Yucca Mountain and vicinity shows most of the usual patterns expected in such contexts: Decreasing {sup 13}C content with depth decreasing {sup 13}C with altitude and reduced {sup 13}C during spring. These patterns exist within the domain of a noisy data set; soil and vegetational heterogeneities, weather, and other factors apparently contribute to isotopic variability in the system. Several soil calcification mechanisms appear to be important, involving characteristic physical and chemical environments and isotopic fractionations. When CO{sub 2} loss from thin soil solutions is an important driving factor, carbonates may contain excess heavy isotopes, compared to equilibrium precipitation with soil fluids. When root calcification serves as a proton generator for plant absorption of soil nutrients, heavy isotope deficiencies are likely. Successive cycles of dissolution and reprecipitation mix and redistribute pedogenic carbonates, and tend to isotopically homogenize and equilibrate pedogenic carbonates with soil fluids.

McConnaughey, T.A.; Whelan, J.F.; Wickland, K.P.; Moscati, R.J.

1994-12-31T23:59:59.000Z

109

Method for detecting and correcting for isotope burn-in during long-term neutron dosimetry exposure  

DOE Patents [OSTI]

A method is described for detecting and correcting for isotope burn-in during-long term neutron dosimetry exposure. In one embodiment, duplicate pairs of solid state track recorder fissionable deposits are used, including a first, fissionable deposit of lower mass to quantify the number of fissions occuring during the exposure, and a second deposit of higher mass to quantify the number of atoms of for instance .sup.239 Pu by alpha counting. In a second embodiment, only one solid state track recorder fissionable deposit is used and the resulting higher track densities are counted with a scanning electron microscope. This method is also applicable to other burn-in interferences, e.g., .sup.233 U in .sup.232 Th or .sup.238 Pu in .sup.237 Np.

Ruddy, Francis H. (Monroeville, PA)

1988-01-01T23:59:59.000Z

110

andliquid chromatography-tandem mass: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

using isotope dilution high performance liquid chromatography-tandem mass spectrometry. Open Access Theses and Dissertations Summary: ??A method has been developed for...

111

Selection of Isotopes and Elements for Fuel Cycle Analysis  

SciTech Connect (OSTI)

Fuel cycle system analysis simulations examine how the selection among fuel cycle options for reactors, fuel, separation, and waste management impact uranium ore utilization, waste masses and volumes, radiotoxicity, heat to geologic repositories, isotope-dependent proliferation resistance measures, and so forth. Previously, such simulations have tended to track only a few actinide and fission product isotopes, those that have been identified as important to a few criteria from the standpoint of recycled material or waste, taken as a whole. After accounting for such isotopes, the residual mass is often characterized as “fission product other” or “actinide other”. However, detailed assessment of separation and waste management options now require identification of key isotopes and residual mass for Group 1A/2A elements (Rb, Cs, Sr, Ba), inert gases (Kr, Xe), halogens (Br, I), lanthanides, transition metals, transuranic (TRU), uranium, actinide decay products. The paper explains the rationale for a list of 81 isotopes and chemical elements to better support separation and waste management assessment in dynamic system analysis models such as Verifiable Fuel Cycle Simulation (VISION)

Steven J. Piet

2009-04-01T23:59:59.000Z

112

Modeling atmospheric stable water isotopes and the potential for constraining cloud processes and  

E-Print Network [OSTI]

a significant part of the observed offset from pure Rayleigh distillation. Isotope fields are shown cycle. These ratios are primarily affected by the fractionation occurring at changes of phase

113

The Sun is a plasma diffuser that sorts atoms by mass  

E-Print Network [OSTI]

The Sun is a magnetic plasma diffuser that selectively moves light elements like H and He and the lighter isotopes of each element to its surface. The Sun formed on the collapsed core of a supernova. It consists mostly of iron, oxygen, nickel, silicon and sulfur made near the SN core, like the rocky planets and ordinary meteorites. H ions, generated by emission and decay of neutrons at the core, are accelerated upward by deep magnetic fields, thus acting as a carrier gas that maintains mass separation in the Sun. Neutron emission from the central neutron star triggers a series of reactions that generate solar luminosity, solar neutrinos, solar mass-fractionation, and an outpouring of the neutron decay product, H, in the solar wind. Mass fractionation appears to have operated in the parent star as well, and likely occurs in other stars.

O. Manuel; S. A. Kamat; M. Mozina

2007-02-05T23:59:59.000Z

114

Isotope shift in the sulfur electron affinity: Observation and theory  

SciTech Connect (OSTI)

The sulfur electron affinities {sup e}A(S) are measured by photodetachment microscopy for the two isotopes {sup 32}S and {sup 34}S (16 752.975 3(41) and 16 752.977 6(85) cm{sup -1}, respectively). The isotope shift in the electron affinity is found to be more probably positive, {sup e}A({sup 34}S)- {sup e}A({sup 32}S) =+0.0023(70) cm{sup -1}, but the uncertainty allows for the possibility that it may be either ''normal''[{sup e}A({sup 34}S) > {sup e}A({sup 32}S)] or ''anomalous''[{sup e}A({sup 34}S) < {sup e}A({sup 32}S)]. The isotope shift is estimated theoretically using elaborate correlation models, monitoring the electron affinity and the mass polarization term expectation value. The theoretical analysis predicts a very large specific mass shift (SMS) that counterbalances the normal mass shift (NMS) and produces an anomalous isotope shift {sup e}A({sup 34}S)- {sup e}A({sup 32}S) =-0.0053(24) cm{sup -1}, field shift corrections included. The total isotope shift can always be written as the sum of the NMS (here +0.0169 cm{sup -1}) and a residual isotope shift (RIS). Since the NMS has nearly no uncertainty, the comparison between experimental and theoretical RIS is more fair. With respective values of -0.0146(70) cm{sup -1} and -0.0222(24) cm{sup -1}, these residual isotope shifts are found to agree within the estimated uncertainties.

Carette, Thomas; Scharf, Oliver; Godefroid, Michel [Chimie Quantique et Photophysique, Universite Libre de Bruxelles - CP160/09, B-1050 Brussels (Belgium); Drag, Cyril; Blondel, Christophe; Delsart, Christian [Laboratoire Aime-Cotton, CNRS, Universite Paris-sud, F-91405 Orsay cedex (France); Froese Fischer, Charlotte [National Institute of Standards and Technology Gaithersburg, Maryland 20899-8420 (United States)

2010-04-15T23:59:59.000Z

115

Determination of isotopic thorium in biological samples by combined alpha spectrometry and neutron activation analysis.  

SciTech Connect (OSTI)

Thorium is a naturally occurring element for whom all isotopes are radioactive . Many of these isotopes are alpha emitting radionuclides, some of which have limits for inhalation lower than plutonium in current regulations . Neutron activation analysis can provide for the low-level determination of 232Th but can not determine other isotopes of dosimetric importance . Biological and environmental samples often have large quantities of materials which activate strongly, limiting the capabilities of instrumental neutron activiation analysis . This paper will discuss the application of a combined technique using alpha spectrometry and radiochemical neutron activiation analysis for the determination of isotopic thorium .

Glover, S. E. (Samuel E.)

2003-01-01T23:59:59.000Z

116

An algorithm for U-Pb isotope dilution data reduction and uncertainty propagation  

E-Print Network [OSTI]

High-precision U-Pb geochronology by isotope dilution-thermal ionization mass spectrometry is integral to a variety of Earth science disciplines, but its ultimate resolving power is quantified by the uncertainties of ...

McLean, Noah Morgan

117

Non-eyring temperature dependence of dynamic isotope effects  

E-Print Network [OSTI]

Our group has recently described a new form of kinetic isotope effect that arises from dynamic selectivity in the bifurcation of a reaction pathway on the slope of an energy surface. Since the selection between products does not occur at a potential...

Ruiz, N. Rebecca

2009-05-15T23:59:59.000Z

118

Absolute neutrino mass measurements  

SciTech Connect (OSTI)

The neutrino mass plays an important role in particle physics, astrophysics and cosmology. In recent years the detection of neutrino flavour oscillations proved that neutrinos carry mass. However, oscillation experiments are only sensitive to the mass-squared difference of the mass eigenvalues. In contrast to cosmological observations and neutrino-less double beta decay (0v2{beta}) searches, single {beta}-decay experiments provide a direct, model-independent way to determine the absolute neutrino mass by measuring the energy spectrum of decay electrons at the endpoint region with high accuracy.Currently the best kinematic upper limits on the neutrino mass of 2.2eV have been set by two experiments in Mainz and Troitsk, using tritium as beta emitter. The next generation tritium {beta}-experiment KATRIN is currently under construction in Karlsruhe/Germany by an international collaboration. KATRIN intends to improve the sensitivity by one order of magnitude to 0.2eV. The investigation of a second isotope ({sup 137}Rh) is being pursued by the international MARE collaboration using micro-calorimeters to measure the beta spectrum. The technology needed to reach 0.2eV sensitivity is still in the R and D phase. This paper reviews the present status of neutrino-mass measurements with cosmological data, 0v2{beta} decay and single {beta}-decay.

Wolf, Joachim [Karlsruhe Institute of Technology (KIT), IEKP, Postfach 3640, 76021 Karlsruhe (Germany)

2011-10-06T23:59:59.000Z

119

Exploration of the neutron-rich mass surface from sup 11 Li to sup 66 Fe  

SciTech Connect (OSTI)

A small revolution in our ability to perform mass measurements of light-mass, neutron-rich nuclei has occurred during the last five years with the extension of the direct, total mass measurement method to fast recoiling nuclei. To date the work of two groups, one using the SPEG spectrometer at GANIL and the other using the TOFI spectrometer at LAMPF, has yielded over 85 mass measurements of which 62 had not been reported previously. Extending from the neutron-halo nucleus {sup 11}Li up to {sup 66}Fe, a region relevant to the astrophysical r-process, these measurements have provided a valuable first glimpse into the interesting nuclear structure present in many of these exotic nuclei. Herein we highlight the nuclear structure insight which as been gained from these measurements, especially that learned from a comparison to recent shell model calculations. Attention is given to: (1) the binding of loosely-bound neutron halo nuclei; (2) the N=14--16 region in the neutron-rich isotopes of O, F, and Ne where the strong two-body interaction plays an important role; (3) the deformed intruder state region around {sup 31}Na of long standing interest; (4) the neutron-rich isotopes of sulfur and chlorine; and (5) the question of the isospin dependence (or independence) of neutron and proton pairing energies in the fp shell. Only the briefest account of this work can be given here; emphasis is placed on the most recent results. 24 refs., 3 figs.

Vieira, D.J.; Wouters, J.M.; Butler, G.W. (Los Alamos National Lab., NM (United States)); Seifert, H.L. (Los Alamos National Lab., NM (United States) Giessen Univ. (Germany). 2. Physikalisches Inst.); Zhou, Z.Y. (Los Alamos National Lab., NM (United States) Nanjing Univ., JS (China). Dept. of Physics and Astronomy); Zhou, X.G.; Tu, X.L.; Lind, V.G. (Utah State Univ., Logan, UT (United States). Dept.

1991-01-01T23:59:59.000Z

120

Exploration of the neutron-rich mass surface from {sup 11}Li to {sup 66}Fe  

SciTech Connect (OSTI)

A small revolution in our ability to perform mass measurements of light-mass, neutron-rich nuclei has occurred during the last five years with the extension of the direct, total mass measurement method to fast recoiling nuclei. To date the work of two groups, one using the SPEG spectrometer at GANIL and the other using the TOFI spectrometer at LAMPF, has yielded over 85 mass measurements of which 62 had not been reported previously. Extending from the neutron-halo nucleus {sup 11}Li up to {sup 66}Fe, a region relevant to the astrophysical r-process, these measurements have provided a valuable first glimpse into the interesting nuclear structure present in many of these exotic nuclei. Herein we highlight the nuclear structure insight which as been gained from these measurements, especially that learned from a comparison to recent shell model calculations. Attention is given to: (1) the binding of loosely-bound neutron halo nuclei; (2) the N=14--16 region in the neutron-rich isotopes of O, F, and Ne where the strong two-body interaction plays an important role; (3) the deformed intruder state region around {sup 31}Na of long standing interest; (4) the neutron-rich isotopes of sulfur and chlorine; and (5) the question of the isospin dependence (or independence) of neutron and proton pairing energies in the fp shell. Only the briefest account of this work can be given here; emphasis is placed on the most recent results. 24 refs., 3 figs.

Vieira, D.J.; Wouters, J.M.; Butler, G.W. [Los Alamos National Lab., NM (United States); Seifert, H.L. [Los Alamos National Lab., NM (United States)]|[Giessen Univ. (Germany). 2. Physikalisches Inst.; Zhou, Z.Y. [Los Alamos National Lab., NM (United States)]|[Nanjing Univ., JS (China). Dept. of Physics and Astronomy; Zhou, X.G.; Tu, X.L.; Lind, V.G. [Utah State Univ., Logan, UT (United States). Dept. of Physics; Loebner, K.E.G. [Muenchen Univ. (Germany). Sektion Physik

1991-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Candidate processes for diluting the {sup 235}U isotope in weapons-capable highly enriched uranium  

SciTech Connect (OSTI)

The United States Department of Energy (DOE) is evaluating options for rendering its surplus inventories of highly enriched uranium (HEU) incapable of being used to produce nuclear weapons. Weapons-capable HEU was earlier produced by enriching uranium in the fissile {sup 235}U isotope from its natural occurring 0.71 percent isotopic concentration to at least 20 percent isotopic concentration. Now, by diluting its concentration of the fissile {sup 235}U isotope in a uranium blending process, the weapons capability of HEU can be eliminated in a manner that is reversible only through isotope enrichment, and therefore, highly resistant to proliferation. To the extent that can be economically and technically justified, the down-blended uranium product will be made suitable for use as commercial reactor fuel. Such down-blended uranium product can also be disposed of as waste if chemical or isotopic impurities preclude its use as reactor fuel.

Snider, J.D.

1996-02-01T23:59:59.000Z

122

ISOTOPE METHODS IN HOMOGENEOUS CATALYSIS.  

SciTech Connect (OSTI)

The use of isotope labels has had a fundamentally important role in the determination of mechanisms of homogeneously catalyzed reactions. Mechanistic data is valuable since it can assist in the design and rational improvement of homogeneous catalysts. There are several ways to use isotopes in mechanistic chemistry. Isotopes can be introduced into controlled experiments and followed where they go or don't go; in this way, Libby, Calvin, Taube and others used isotopes to elucidate mechanistic pathways for very different, yet important chemistries. Another important isotope method is the study of kinetic isotope effects (KIEs) and equilibrium isotope effect (EIEs). Here the mere observation of where a label winds up is no longer enough - what matters is how much slower (or faster) a labeled molecule reacts than the unlabeled material. The most careti studies essentially involve the measurement of isotope fractionation between a reference ground state and the transition state. Thus kinetic isotope effects provide unique data unavailable from other methods, since information about the transition state of a reaction is obtained. Because getting an experimental glimpse of transition states is really tantamount to understanding catalysis, kinetic isotope effects are very powerful.

BULLOCK,R.M.; BENDER,B.R.

2000-12-01T23:59:59.000Z

123

Oak Ridge Isotope Products and Services - Current and Expected Supply and Demand  

SciTech Connect (OSTI)

Oak Ridge National Laboratory (ORNL) has been a major center of isotope production research, development, and distribution for over 50 years. Currently, the major isotope production activities include (1) the production of transuranium element radioisotopes, including 252 Cf; (2) the production of medical and industrial radioisotopes; (3) maintenance and expansion of the capabilities for production of enriched stable isotopes; and, (4) preparation of a wide range of custom-order chemical and physical forms of isotope products, particularly in accelerator physics research. The recent supply of and demand for isotope products and services in these areas, research and development (R&D), and the capabilities for future supply are described in more detail below. The keys to continuing the supply of these important products and services are the maintenance, improvement, and potential expansion of specialized facilities, including (1) the High Flux Isotope Reactor (HFIR), (2) the Radiochemical Engineering Development Center (REDC) and Radiochemical Development Laboratory (RDL) hot cell facilities, (3) the electromagnetic calutron mass separators and the plasma separation process equipment for isotope enrichment, and (4) the Isotope Research Materials Laboratory (IRML) equipment for preparation of specialized chemical and physical forms of isotope products. The status and plans for these ORNL isotope production facilities are also described below.

Aaron, W.S.; Alexander, C.W.; Cline, R.L.; Collins, E.D.; Klein, J.A.; Knauer, J.B., Jr.; Mirzadeh, S.

1999-08-29T23:59:59.000Z

124

ARM - Measurement - Isotope ratio  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc Documentation RUC : XDCResearch Related InformationAciddropletgovMeasurementsIsotope ratio ARM

125

Laser isotope separation of erbium and other isotopes  

DOE Patents [OSTI]

Laser isotope separation is accomplished using at least two photoionization pathways of an isotope simultaneously, where each pathway comprises two or more transition steps. This separation method has been applied to the selective photoionization of erbium isotopes, particularly for the enrichment of .sup.167 Er. The hyperfine structure of .sup.167 Er was used to find two three-step photoionization pathways having a common upper energy level.

Haynam, Christopher A. (3035 Ferdale Ct., Pleasanton, CA 94566); Worden, Earl F. (117 Vereda del Ciervo, Diablo, CA 94528)

1995-01-01T23:59:59.000Z

126

Water isotopes and the general circulation  

E-Print Network [OSTI]

is depleted. #12;Distillation: vapor and condensate Isotopic fractionation -35 -30 -25 -20 -15 -10 -5 0 5 0 0 of idealized isotopic fractionation Expression of isotopic fractionation in nature Attributing signals" 18 = (R/Rstandard-1)x1000 R = moles of H2 18O/moles of H2 16O #12;Isotopic fractionation Isotopic

Noone, David

127

Accelerator mass spectrometry: from nuclear physics to dating  

SciTech Connect (OSTI)

The discussion reviews the use of accelerators originally intended for nuclear physics to do high resolution mass spectrometry for the purpose of isotope dating and age estimation of materials. (GHT)

Kutschera, W.

1982-01-01T23:59:59.000Z

128

Development of Halide and Oxy-Halides for Isotopic Separations  

SciTech Connect (OSTI)

The goal of this project was to synthesize a volatile form of Np for introduction into mass spectrometers at INL. Volatile solids of the 5f elements are typically those of the halides (e.g. UF6), however fluorine is highly corrosive to the sensitive internal components of the mass separator, and the other volatile halides exist as several different stable isotopes in nature. However, iodide is both mono-isotopic and volatile, and as such presents an avenue for creation of a form of Np suitable for introduction into the mass separator. To accomplish this goal, the technical work in the project sought to establish a novel synthetic route for the conversion NpO2+ (dissolved in nitric acid) to NpI3 and NpI4.

Leigh R. Martin; Aaron T. Johnson; Jana Pfeiffer; Martha R. Finck

2014-10-01T23:59:59.000Z

129

RADIOCHEMICAL STUDIES OF NEUTRON DEFICIENT ACTINIDE ISOTOPES  

E-Print Network [OSTI]

Isotope Targets and Foils, AERE-R 5097, Paper 10 (1965). V.Isotope Targets and Foils, AERE-R 5097 Paper 12 (1965). K.M.Isotope Targets and Foils, AERE-R-5097 Paper 11 (1965). M.

Williams, Kimberly Eve

2011-01-01T23:59:59.000Z

130

Chromatographic hydrogen isotope separation  

DOE Patents [OSTI]

Intermetallic compounds with the CaCu.sub.5 type of crystal structure, particularly LaNiCo.sub.4 and CaNi.sub.5, exhibit high separation factors and fast equilibrium times and therefore are useful for packing a chromatographic hydrogen isotope separation colum. The addition of an inert metal to dilute the hydride improves performance of the column. A large scale mutli-stage chromatographic separation process run as a secondary process off a hydrogen feedstream from an industrial plant which uses large volumes of hydrogen can produce large quantities of heavy water at an effective cost for use in heavy water reactors.

Aldridge, Frederick T. (Livermore, CA)

1981-01-01T23:59:59.000Z

131

Appendix II. Calculation of Slope Factors for Naturally Occurring Radionuclides  

E-Print Network [OSTI]

Appendix II. Calculation of Slope Factors for Naturally Occurring Radionuclides In developing calculates the slope factors for the naturally occurring radionuclides under consideration. The Radionuclide products with half-lives of less than 6 months). As explained below, naturally occurring radionuclides

132

Upper limits for the existence of long-lived isotopes of roentgenium in natural gold  

SciTech Connect (OSTI)

A sensitive search for isotopes of a superheavy element (SHE) in natural gold materials has been performed with accelerator mass spectrometry at the Vienna Environmental Research Accelerator, which is based on a 3-MV tandem accelerator. Because the most likely SHE in gold is roentgenium (Rg, Z = 111), the search concentrated on Rg isotopes. Two different mass regions were explored: (i) For the neutron-deficient isotopes {sup 261}Rg and {sup 265}Rg, abundance limits in gold of 3x10{sup -16} were reached (no events observed). This is in stark contrast to the findings of Marinov et al.[Int. J. Mod. Phys. E 18, 621 (2009)], who reported positive identification of these isotopes with inductively coupled plasma sector field mass spectrometry in the (1-10)x10{sup -10} abundance range. (ii) Theoretical models of SHEs predict a region of increased stability around the proton and neutron shell closures of Z = 114 and N = 184. We therefore investigated eight heavy Rg isotopes, {sup A}Rg, A = 289, 290, 291, 292, 293, 294, 295, and 296. For six isotopes no events were observed, setting limits also in the 10{sup -16} abundance range. For {sup 291}Rg and {sup 294}Rg we observed two and nine events, respectively, which results in an abundance in the 10{sup -15} range. However, pileup of a particularly strong background in these cases makes a positive identification as Rg isotopes--even after pileup correction--unlikely.

Dellinger, F.; Kutschera, W.; Forstner, O.; Golser, R.; Priller, A.; Steier, P.; Wallner, A.; Winkler, G. [University of Vienna, Faculty of Physics, Vienna Environmental Research Accelerator (VERA) Laboratory, Waehringer Strasse 17, A-1090 Wien (Austria)

2011-01-15T23:59:59.000Z

133

Isotopic Trends in Production of Superheavies  

SciTech Connect (OSTI)

The isotopic trends are discussed for cold and hot fusion reactions leading to superheavies. The possibilities of production of new isotopes in incomplete fusion reactions are treated.

Antonenko, N.V. [Institut fuer Theoretische Physik der Justus-Liebig-Universitaet, D-35392 Giessen (Germany); Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Adamian, G.G.; Zubov, A.S. [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Scheid, W. [Institut fuer Theoretische Physik der Justus-Liebig-Universitaet, D-35392 Giessen (Germany)

2005-11-21T23:59:59.000Z

134

The marine biogeochemistry of zinc isotopes  

E-Print Network [OSTI]

Zinc (Zn) stable isotopes can record information about important oceanographic processes. This thesis presents data on Zn isotopes in anthropogenic materials, hydrothermal fluids and minerals, cultured marine phytoplankton, ...

John, Seth G

2007-01-01T23:59:59.000Z

135

Formation of Light Isotopes by Protons and Deuterons of 3.65 GeV/nucleon on Separated Tin Isotopes  

E-Print Network [OSTI]

We measure cross sections for residual nuclide formation in the mass range 6 tin isotopes (112-Sn, 118-Sn, 120-Sn, 124-Sn). The experimental data are compared with calculations by the codes FLUKA, LAHET, CEM03, and LAQGSM03. Scaling behavior is observed for the whole mass region of residual nuclei, showing a possible multifragmentation mechanism for the formation of light products (6 < A < 31). Our analysis of the isoscaling dependence also shows a possible contribution of multifragmentation to the production of heavier nuclides, in the mass region 39 < A < 81.

A. R. Balabekyan; A. S. Danagulyan; J. R. Drnoyan; G. H. Hovhannisyan; J. Adam; V. G. Kalinnikov; M. I. Krivopustov; V. S. Pronskikh; V. I. Stegailov; A. A. Solnyshkin; P. Chaloun; V. M. Tsoupko-Sitnikov; S. G. Mashnik; K. K. Gudima

2005-06-22T23:59:59.000Z

136

The use of carbon stable isotope ratios in drugs characterization  

SciTech Connect (OSTI)

Isotopic Ratio Mass Spectrometry (IRMS) is an effective toll to be used for drug product authentication. The isotopic composition could be used to assist in the differentiation between batches of drugs and assist in the identification of counterfeit materials on the market. Only two factors affect the isotopic ratios in pharmaceutical components: the isotopic composition of the raw materials and the synthetic processes performed upon them. Counterfeiting of pharmaceutical drugs threatens consumer confidence in drug products companies' economical well-being. In this preliminary study, the analyzed samples consist in two types of commercially available analgesics, which were purchases from Romanian pharmacies. Differences in ?{sup 13}C between batches from ?29.7 to ?31.6% were observed, demonstrating that this method can be used to differentiate among individual drug batches and subsequently identify counterfeits on the market. On the other hand, carbon isotopic ratios differences among producers were recorded, the variations being between ?31.3 to ?34.9% for the same type of analgesic, but from different manufactures.

Magdas, D. A., E-mail: gabriela.cristea@itim-cj.ro; Cristea, G., E-mail: gabriela.cristea@itim-cj.ro; Bot, A., E-mail: gabriela.cristea@itim-cj.ro; Mirel, V., E-mail: gabriela.cristea@itim-cj.ro [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath Str., 400293 Cluj-Napoca (Romania)

2013-11-13T23:59:59.000Z

137

System size effects in the N/Z dependence of balance energy for isotopic series  

E-Print Network [OSTI]

We study the system size effects in the N/Z dependence of balance energy for the isotopic series. We find drastic effect of symmetry energy on the N/Z dependence of E$_{bal}$ throughout the mass range. We also find that the N/Z dependence of E$_{bal}$ for isotopic series of lighter system is slightly more sensitive to symmetry energy as compared to that of heavier systems. We also study the mass dependence of E$_{bal}$ for the N/Z range from 1.0-2.0. We find that the mass dependence of E$_{bal}$ varies with the N/Z ratio.

Sakshi Gautam; Aman Deep Sood

2011-07-25T23:59:59.000Z

138

Ab Initio Nuclear Structure and Reaction Calculations for Rare Isotopes  

SciTech Connect (OSTI)

We have developed a novel ab initio symmetry-adapted no-core shell model (SA-NCSM), which has opened the intermediate-mass region for ab initio investigations, thereby providing an opportunity for first-principle symmetry-guided applications to nuclear structure and reactions for nuclear isotopes from the lightest p-shell systems to intermediate-mass nuclei. This includes short-lived proton-rich nuclei on the path of X-ray burst nucleosynthesis and rare neutron-rich isotopes to be produced by the Facility for Rare Isotope Beams (FRIB). We have provided ab initio descriptions of high accuracy for low-lying (including collectivity-driven) states of isotopes of Li, He, Be, C, O, Ne, Mg, Al, and Si, and studied related strong- and weak-interaction driven reactions that are important, in astrophysics, for further understanding stellar evolution, X-ray bursts and triggering of s, p, and rp processes, and in applied physics, for electron and neutrino-nucleus scattering experiments as well as for fusion ignition at the National Ignition Facility (NIF).

Draayer, Jerry P [Louisiana State University

2014-09-28T23:59:59.000Z

139

Determining Planes Along Which Earthquakes Occur- Method of Applicatio...  

Open Energy Info (EERE)

Along Which Earthquakes Occur- Method of Application to Earthquakes Accompanying Hydraulic Fracturing Jump to: navigation, search OpenEI Reference LibraryAdd to library...

140

NEUTRON-POOR NICKEL ISOTOPE ANOMALIES IN METEORITES  

SciTech Connect (OSTI)

We present new, mass-independent, Ni isotope data for a range of bulk chondritic meteorites. The data are reported as {epsilon}{sup 60}Ni{sub 58/61}, {epsilon}{sup 62}Ni{sub 58/61}, and {epsilon}{sup 64}Ni{sub 58/61}, or the parts per ten thousand deviations from a terrestrial reference, the NIST SRM 986 standard, of the {sup 58}Ni/{sup 61}Ni internally normalized {sup 60}Ni/{sup 61}Ni, {sup 62}Ni/{sup 61}Ni, and {sup 64}Ni/{sup 61}Ni ratios. The chondrites show a range of 0.15, 0.29, and 0.84 in {epsilon}{sup 60}Ni{sub 58/61}, {epsilon}{sup 62}Ni{sub 58/61}, and {epsilon}{sup 64}Ni{sub 58/61} relative to a typical sample precision of 0.03, 0.05, and 0.08 (2 s.e.), respectively. The carbonaceous chondrites show the largest positive anomalies, enstatite chondrites have approximately terrestrial ratios, though only EH match Earth's composition within uncertainty, and ordinary chondrites show negative anomalies. The meteorite data show a strong positive correlation between {epsilon}{sup 62}Ni{sub 58/61} and {epsilon}{sup 64}Ni{sub 58/61}, an extrapolation of which is within the error of the average of previous measurements of calcium-, aluminium-rich inclusions. Moreover, the slope of this bulk meteorite array is 3.003 {+-} 0.166 which is within the error of that expected for an anomaly solely on {sup 58}Ni. We also determined to high precision ({approx}10 ppm per AMU) the mass-dependent fractionation of two meteorite samples which span the range of {epsilon}{sup 62}Ni{sub 58/61} and {epsilon}{sup 64}Ni{sub 58/61}. These analyses show that 'absolute' ratios of {sup 58}Ni/{sup 61}Ni vary between these two samples whereas those of {sup 62}Ni/{sup 61}Ni and {sup 64}Ni/{sup 61}Ni do not. Thus, Ni isotopic differences seem most likely explained by variability in the neutron-poor {sup 58}Ni, and not correlated anomalies in the neutron-rich isotopes, {sup 62}Ni and {sup 64}Ni. This contrasts with previous inferences from mass-independent measurements of Ni and other transition elements which invoked variable contributions of a neutron-rich component. We have examined different nucleosynthetic environments to determine the possible source of the anomalous material responsible for the isotopic variations observed in Ni and other transition elements within bulk samples. We find that the Ni isotopic variability of the solar system cannot be explained by mixing with a component of bulk stellar ejecta from either SN II, Wolf-Rayet or, an asymptotic giant branch source and is unlikely to result from bulk mixing of material from an SN Ia. However, variable admixture of material from the Si/S zone of an SN II can create all the characteristics of Ni isotope variations in solar system materials. Moreover, these characteristics can also be provided by an SN II with a range of masses from 15 to 40 M{sub Sun }, showing that input from SN II is a robust source for Ni isotope variations in the solar system. Correlations of Ni isotope anomalies with O, Cr, and Ti isotope ratios and Pb/Yb in bulk meteorites suggest that the heterogeneous distribution of isotopic anomalies in the early solar system likely resulted from nebular sorting of chemically or physically different materials bearing different amounts of isotopes synthesized proximally to the collapse of the protosolar nebula.

Steele, Robert C. J.; Coath, Christopher D.; Regelous, Marcel; Elliott, Tim [Bristol Isotope Group, School of Earth Sciences, University of Bristol, Wills Memorial Building, Queen's Road, Bristol BS8 1RJ (United Kingdom); Russell, Sara, E-mail: r.steele@uclmail.net [Meteoritics and Cosmic mineralogy, Natural History Museum, Cromwell Road, London SW7 5BD (United Kingdom)

2012-10-10T23:59:59.000Z

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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141

Method for laser induced isotope enrichment  

DOE Patents [OSTI]

Methods for separating isotopes or chemical species of an element and causing enrichment of a desired isotope or chemical species of an element utilizing laser ablation plasmas to modify or fabricate a material containing such isotopes or chemical species are provided. This invention may be used for a wide variety of materials which contain elements having different isotopes or chemical species.

Pronko, Peter P.; Vanrompay, Paul A.; Zhang, Zhiyu

2004-09-07T23:59:59.000Z

142

Apparatus and process for separating hydrogen isotopes  

DOE Patents [OSTI]

The apparatus and process for separating hydrogen isotopes is provided using dual columns, each column having an opposite hydrogen isotopic effect such that when a hydrogen isotope mixture feedstock is cycled between the two respective columns, two different hydrogen isotopes are separated from the feedstock.

Heung, Leung K; Sessions, Henry T; Xiao, Xin

2013-06-25T23:59:59.000Z

143

Electrochemical Isotope Effect and Lithium Isotope Separation Jay R. Black,  

E-Print Network [OSTI]

results showing a large lithium isotope separation due to electrodeposition. The fractionation is tunable lithium were plated from solutions of 1 M LiClO4 in propylene carbonate (PC) on planar nickel electrodes

Mcdonough, William F.

144

Compelling Research Opportunities using Isotopes  

SciTech Connect (OSTI)

Isotopes are vital to the science and technology base of the US economy. Isotopes, both stable and radioactive, are essential tools in the growing science, technology, engineering, and health enterprises of the 21st century. The scientific discoveries and associated advances made as a result of the availability of isotopes today span widely from medicine to biology, physics, chemistry, and a broad range of applications in environmental and material sciences. Isotope issues have become crucial aspects of homeland security. Isotopes are utilized in new resource development, in energy from bio-fuels, petrochemical and nuclear fuels, in drug discovery, health care therapies and diagnostics, in nutrition, in agriculture, and in many other areas. The development and production of isotope products unavailable or difficult to get commercially have been most recently the responsibility of the Department of Energy's Nuclear Energy program. The President's FY09 Budget request proposed the transfer of the Isotope Production program to the Department of Energy's Office of Science in Nuclear Physics and to rename it the National Isotope Production and Application program (NIPA). The transfer has now taken place with the signing of the 2009 appropriations bill. In preparation for this, the Nuclear Science Advisory Committee (NSAC) was requested to establish a standing subcommittee, the NSAC Isotope Subcommittee (NSACI), to advise the DOE Office of Nuclear Physics. The request came in the form of two charges: one, on setting research priorities in the short term for the most compelling opportunities from the vast array of disciplines that develop and use isotopes and two, on making a long term strategic plan for the NIPA program. This is the final report to address charge 1. NSACI membership is comprised of experts from the diverse research communities, industry, production, and homeland security. NSACI discussed research opportunities divided into three areas: (1) medicine, pharmaceuticals, and biology, (2) physical sciences and engineering, and (3) national security and other applications. In each area, compelling research opportunities were considered and the subcommittee as a whole determined the final priorities for research opportunities as the foundations for the recommendations. While it was challenging to prioritize across disciplines, our order of recommendations reflect the compelling research prioritization along with consideration of time urgency for action as well as various geopolitical market issues. Common observations to all areas of research include the needs for domestic availability of crucial stable and radioactive isotopes and the education of the skilled workforce that will develop new advances using isotopes in the future. The six recommendations of NSACI reflect these concerns and the compelling research opportunities for potential new discoveries. The science case for each of the recommendations is elaborated in the respective chapters.

None

2009-04-23T23:59:59.000Z

145

Modeling of temporal behavior of isotopic exchange between gaseous hydrogen and palladium hydride power  

SciTech Connect (OSTI)

A parametric rate-equation model is described which depicts the time dependent behavior of the isotopic exchange process occurring between the solid and gas phases in gaseous hydrogen (deuterium) flows through packed-powder palladium deuteride (hydride) beds. The exchange mechanism is assumed to be rate-limited by processes taking place on the surface of the powder. The fundamental kinetic parameter of the model is the isotopic exchange probability, p, which is the probability that an isotopic exchange event occurs during a collision of a gas phase atom with the surface. Isotope effects between the gas and solid phases are explicitly included in terms of the isotope separation factor, ..cap alpha... Results of the model are compared with recent experimental measurements of isotope exchange in the ..beta..-phase hydrogen/palladium system and, using a literature value of ..cap alpha.. = 2.4, a good description of the experimental data is obtained for p approx. 10/sup -7/. In view of the importance of the isotope effects in the hydrogen/palladium system and the range of ..cap alpha.. values reported for the ..beta..-phase in the literature, the sensitivity of the model results to a variation in the value of ..cap alpha.. is examined.

Melius, C F; Foltz, G W

1987-01-01T23:59:59.000Z

146

Original article Hydraulic conductance of two co-occuring neotropical  

E-Print Network [OSTI]

Original article Hydraulic conductance of two co-occuring neotropical understory shrubs December 1999) Abstract ­ Whole plant hydraulic conductance was measured for two co-occuring neotropical hydraulic con- ductance and leaf specific conducance in the drought-avoiding species, P. trigonum, than

Paris-Sud XI, Université de

147

Metallic beam development for the Facility for Rare Isotope Beam  

SciTech Connect (OSTI)

The Facility for Rare Isotope Beams (FRIB) at Michigan State University (MSU) will accelerate a primary ion beam to energies beyond 200 MeV/u using a superconducting RF linac and will reach a maximum beam power of 400 kW on the fragmentation target. The beam intensity needed from the ECR ion source is expected to be between 0.4 and 0.5 emA for most medium mass to heavy mass elements. Adding to the challenge of reaching the required intensity, an expanded list of primary beams of interest has been established based on the production rate and the number of isotope beams that could be produced with FRIB. We report here on the development done for some of the beam in the list including mercury (natural), molybdenum ({sup 98}Mo), and selenium ({sup 82}Ser)

Machicoane, Guillaume, E-mail: machicoa@nscl.msu.edu; Cole, Dallas; Leitner, Daniela; Neben, Derek; Tobos, Larry [Facility for Rare Isotope Beam, Michigan State University, East Lansing, Michigan 48824 (United States)] [Facility for Rare Isotope Beam, Michigan State University, East Lansing, Michigan 48824 (United States)

2014-02-15T23:59:59.000Z

148

Novel hybrid isotope separation scheme and apparatus  

DOE Patents [OSTI]

A method is described for yielding selectively a desired enrichment in a specific isotope including the steps of inputting into a spinning chamber a gas from which the specific isotope is to be isolated, radiating the gas with frequencies characteristic of the absorption of a particular isotope of the atomic or molecular gas, thereby inducing a photoionization reaction of the desired isotope, and collecting the specific isotope ion by suitable ion collection means. 3 figures.

Maya, J.

1991-06-18T23:59:59.000Z

149

Novel hybrid isotope separation scheme and apparatus  

DOE Patents [OSTI]

A method of yielding selectively a desired enrichment in a specific isotope including the steps of inputting into a spinning chamber a gas from which the specific isotope is to be isolated, radiating the gas with frequencies characteristic of the absorption of a particular isotope of the atomic or molecular gas, thereby inducing a photoionization reaction of the desired isotope, and collecting the specific isotope ion by suitable ion collection means.

Maya, Jakob (Brookline, MA)

1991-01-01T23:59:59.000Z

150

Chromium isotopes as indicators of hexavalent chromium reduction  

SciTech Connect (OSTI)

This is the final report for a university research project which advanced development of a new technology for identifying chemical reduction of hexavalent chromium contamination in groundwater systems. Reduction renders mobile and toxic hexavalent chromium immobile and less toxic. The new method uses stable isotope ratio measurements, which are made using multicollector ICP-mass spectrometry. The main objectives of this project were completed during the project period and two peer-reviewed articles were published to disseminate the information gained.

Johnson, Thomas M.

2012-03-20T23:59:59.000Z

151

Higher-Order Mass Defect Analysis for Mass Spectra of Complex Organic Mixtures  

SciTech Connect (OSTI)

Higher-order mass defect analysis is introduced as a unique formula assignment and visualization method for the analysis of complex mass spectra. This approach is an extension of the concepts of Kendrick mass transformation widely used for identification of homologous compounds differing only by a number of base units (e.g., CH2, H2, O, CH2O, etc.) in complex mixtures. We present an iterative renormalization routine for defining higher order homologous series and multidimensional clustering of mass spectral features. This approach greatly simplifies visualization of complex mass spectra and increases the number of chemical formulae that can be confidently assigned for given mass accuracy. The potential for using higher-order mass defects for data reduction and visualization is shown. Higher-order mass defect analysis is described and demonstrated through third-order analysis of a de-isotoped high-resolution mass spectrum of crude oil containing nearly 13,000 peaks.

Roach, Patrick J.; Laskin, Julia; Laskin, Alexander

2011-06-15T23:59:59.000Z

152

ZIRCONIUM—HAFNIUM ISOTOPE EVIDENCE FROM METEORITES FOR THE DECOUPLED SYNTHESIS OF LIGHT AND HEAVY NEUTRON-RICH NUCLEI  

SciTech Connect (OSTI)

Recent work based on analyses of meteorite and terrestrial whole-rock samples showed that the r- and s- process isotopes of Hf were homogeneously distributed throughout the inner solar system. We report new Hf isotope data for Calcium-Aluminum-rich inclusions (CAIs) of the CV3 carbonaceous chondrite Allende, and novel high-precision Zr isotope data for these CAIs and three carbonaceous chondrites (CM, CO, CK). Our Zr data reveal enrichments in the neutron-rich isotope {sup 96}Zr (?1? in {sup 96}Zr/{sup 90}Zr) for bulk chondrites and CAIs (?2?). Potential isotope effects due to incomplete sample dissolution, galactic and cosmic ray spallation, and the nuclear field shift are assessed and excluded, leading to the conclusion that the {sup 96}Zr isotope variations are of nucleosynthetic origin. The {sup 96}Zr enrichments are coupled with {sup 50}Ti excesses suggesting that both nuclides were produced in the same astrophysical environment. The same CAIs also exhibit deficits in r-process Hf isotopes, which provides strong evidence for a decoupling between the nucleosynthetic processes that produce the light (A ? 130) and heavy (A > 130) neutron-rich isotopes. We propose that the light neutron-capture isotopes largely formed in Type II supernovae (SNeII) with higher mass progenitors than the supernovae that produced the heavy r-process isotopes. In the context of our model, the light isotopes (e.g. {sup 96}Zr) are predominantly synthesized via charged-particle reactions in a high entropy wind environment, in which Hf isotopes are not produced. Collectively, our data indicates that CAIs sampled an excess of materials produced in a normal mass (12-25 M{sub ?}) SNII.

Akram, W.; Schönbächler, M. [School of Earth, Atmospheric and Environmental Sciences, The University of Manchester, Oxford Road, Manchester, M13 9PL (United Kingdom); Sprung, P. [Institut für Planetologie, Universität Münster, Wilhelm-Klemm-Strasse 10, D-48149 Münster (Germany); Vogel, N. [Institute for Geochemistry and Petrology, ETH, Clausiusstrasse 25, 8092 Zürich (Switzerland)

2013-11-10T23:59:59.000Z

153

Isotope production facility produces cancer-fighting actinium  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Cancer therapy gets a boost from new isotope Isotope production facility produces cancer-fighting actinium A new medical isotope project shows promise for rapidly producing major...

154

Consistency test of neutrinoless double beta decay with one isotope  

E-Print Network [OSTI]

We discuss a consistency test which makes it possible to discriminate unknown nuclear background lines from neutrinoless double beta decay with only one isotope. By considering both the transition to the ground state and to the first excited $0^+$ state, a sufficiently large detector can reveal if neutrinoless double beta decay or some other nuclear physics process is at work. Such a detector could therefore simultaneously provide a consistency test for a certain range of Majorana masses and be sensitive to lower values of the effective Majorana mass.

Michael Duerr; Manfred Lindner; Kai Zuber

2011-11-17T23:59:59.000Z

155

Consistency test of neutrinoless double beta decay with one isotope  

SciTech Connect (OSTI)

We discuss a consistency test which makes it possible to discriminate unknown nuclear background lines from neutrinoless double beta decay with only one isotope. By considering both the transition to the ground state and to the first excited 0{sup +} state, a sufficiently large detector can reveal if neutrinoless double beta decay or some other nuclear physics process is at work. Such a detector could therefore simultaneously provide a consistency test for a certain range of Majorana masses and be sensitive to lower values of the effective Majorana mass .

Duerr, Michael; Lindner, Manfred [Max-Planck-Institut fuer Kernphysik, Postfach 10 39 80, 69029 Heidelberg (Germany); Zuber, Kai [Technical University Dresden, Institut fuer Kern- und Teilchenphysik, 01069 Dresden (Germany)

2011-11-01T23:59:59.000Z

156

99.996 %{sup 12}C films isotopically enriched and deposited in situ  

SciTech Connect (OSTI)

Ionizing natural abundance carbon dioxide gas, we extract and mass select the ions, depositing thin films isotopically enriched to 99.9961(4) %{sup 12}C as measured by secondary ion mass spectrometry (SIMS). In solid state quantum information, coherence times of nitrogen-vacancy (NV) centers in {sup 12}C enriched diamond exceeding milliseconds demonstrate the viability of NV centers as qubits, motivating improved isotopic enrichment. NV centers in diamond are particularly attractive qubit candidates due to the optical accessibility of the spin states. We present SIMS analysis and cross-sectional scanning electron microscopy of {sup 12}C enriched thin film samples grown with this method.

Dwyer, K. J. [Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20740 (United States) [Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20740 (United States); National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8423 (United States); Pomeroy, J. M.; Simons, D. S. [National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8423 (United States)] [National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8423 (United States)

2013-06-24T23:59:59.000Z

157

PLANETARY-SCALE STRONTIUM ISOTOPIC HETEROGENEITY AND THE AGE OF VOLATILE DEPLETION OF EARLY SOLAR SYSTEM MATERIALS  

SciTech Connect (OSTI)

Isotopic anomalies in planetary materials reflect both early solar nebular heterogeneity inherited from presolar stellar sources and processes that generated non-mass-dependent isotopic fractionations. The characterization of isotopic variations in heavy elements among early solar system materials yields important insight into the stellar environment and formation of the solar system, and about initial isotopic ratios relevant to long-term chronological applications. One such heavy element, strontium, is a central element in the geosciences due to wide application of the long-lived {sup 87}Rb-{sup 87}Sr radioactive as a chronometer. We show that the stable isotopes of Sr were heterogeneously distributed at both the mineral scale and the planetary scale in the early solar system, and also that the Sr isotopic heterogeneities correlate with mass-independent oxygen isotope variations, with only CI chondrites plotting outside of this correlation. The correlation implies that most solar system material formed by mixing of at least two isotopically distinct components: a CV-chondrite-like component and an O-chondrite-like component, and possibly a distinct CI-chondrite-like component. The heterogeneous distribution of Sr isotopes may indicate that variations in initial {sup 87}Sr/{sup 86}Sr of early solar system materials reflect isotopic heterogeneity instead of having chronological significance, as interpreted previously. For example, given the differences in {sup 84}Sr/{sup 86}Sr between calcium aluminum inclusions and eucrites ({epsilon}{sup 84}Sr > 2), the difference in age between these materials would be {approx}6 Ma shorter than previously interpreted, placing the Sr chronology in agreement with other long- and short-lived isotope systems, such as U-Pb and Mn-Cr.

Moynier, Frederic; Podosek, Frank A. [Department of Earth and Planetary Science and McDonnell Center for Space Sciences, Washington University, St. Louis, MO 63130 (United States); Day, James M. D. [Geosciences Research Division, Scripps Institution of Oceanography, La Jolla, CA 92093-0244 (United States); Okui, Wataru; Yokoyama, Tetsuya [Department of Earth and Planetary Sciences, Tokyo Institute of Technology, Tokyo 152-8551 (Japan); Bouvier, Audrey [Department of Earth Sciences, University of Minnesota, Minneapolis, MN 55455-0231 (United States); Walker, Richard J., E-mail: moynier@levee.wustl.edu, E-mail: fap@levee.wustl.edu, E-mail: jmdday@ucsd.edu, E-mail: rjwalker@umd.edu, E-mail: okui.w.aa@m.titech.ac.jp, E-mail: tetsuya.yoko@geo.titech.ac.jp, E-mail: abouvier@umn.edu [Department of Geology, University of Maryland, College Park, MD 20742 (United States)

2012-10-10T23:59:59.000Z

158

Fluctuations in Species-Level Protein Expression Occur during Element and Nutrient Cycling in the Subsurface  

SciTech Connect (OSTI)

While microbial activities in environmental systems play a key role in the utilization and cycling of essential elements and compounds, microbial activity and growth frequently fluctuates in response to environmental stimuli and perturbations. To investigate these fluctuations within a saturated aquifer system, we monitored a carbon-stimulated in situ Geobacter population while iron reduction was occurring, using 16S rRNA abundances and high-resolution tandem mass spectrometry proteome measurements. Following carbon amendment, 16S rRNA analysis of temporally separated samples revealed the rapid enrichment of Geobacter-like environmental strains with strong similarity to G. bemidjiensis. Tandem mass spectrometry proteomics measurements suggest high carbon flux through Geobacter respiratory pathways, and the synthesis of anapleurotic four carbon compounds from acetyl-CoA via pyruvate ferredoxin oxidoreductase activity. Across a 40-day period where Fe(III) reduction was occurring, fluctuations in protein expression reflected changes in anabolic versus catabolic reactions, with increased levels of biosynthesis occurring soon after acetate arrival in the aquifer. In addition, localized shifts in nutrient limitation were inferred based on expression of nitrogenase enzymes and phosphate uptake proteins. These temporal data offer the first example of differing microbial protein expression associated with changing geochemical conditions in a subsurface environment.

Wilkins, Michael J.; Wrighton, Kelly C.; Nicora, Carrie D.; Williams, Kenneth H.; McCue, Lee Ann; Handley, Kim M.; Miller, C. S.; Giloteaux, L.; Montgomery, A. P.; Lovley, Derek R.; Banfield, Jillian F.; Long, Philip E.; Lipton, Mary S.

2013-03-05T23:59:59.000Z

159

Identification of isotopically primitive interplanetary dust particles: A NanoSIMS isotopic imaging study  

E-Print Network [OSTI]

Identification of isotopically primitive interplanetary dust particles: A NanoSIMS isotopic imaging contain larger regions with more modest enrichments in 15 N, leading to average bulk N isotopic of those IDPs that have anomalous bulk N isotopic compositions. These particles typically also contain

160

Spinelolivine magnesium isotope thermometry in the mantle and implications for the Mg isotopic composition of Earth  

E-Print Network [OSTI]

Spinel­olivine magnesium isotope thermometry in the mantle and implications for the Mg isotopic: magnesium isotopes mantle geochemistry meteorites MC-ICPMS The magnesium isotopic composition of Earth., 2004; Poitrasson et al., 2005; Georg et al., 2007; Poitrasson, 2007; Weyer et al., 2007). Magnesium

Manning, Craig

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Online Catalog of Isotope Products from DOE's National Isotope Development Center  

DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

The National Isotope Development Center (NIDC) interfaces with the User Community and manages the coordination of isotope production across the facilities and business operations involved in the production, sale, and distribution of isotopes. A virtual center, the NIDC is funded by the Isotope Development and Production for Research and Applications (IDPRA) subprogram of the Office of Nuclear Physics in the U.S. Department of Energy Office of Science. The Isotope subprogram supports the production, and the development of production techniques of radioactive and stable isotopes that are in short supply for research and applications. Isotopes are high-priority commodities of strategic importance for the Nation and are essential for energy, medical, and national security applications and for basic research; a goal of the program is to make critical isotopes more readily available to meet domestic U.S. needs. This subprogram is steward of the Isotope Production Facility (IPF) at Los Alamos National Laboratory (LANL), the Brookhaven Linear Isotope Producer (BLIP) facility at BNL, and hot cell facilities for processing isotopes at ORNL, BNL and LANL. The subprogram also coordinates and supports isotope production at a suite of university, national laboratory, and commercial accelerator and reactor facilities throughout the Nation to promote a reliable supply of domestic isotopes. The National Isotope Development Center (NIDC) at ORNL coordinates isotope production across the many facilities and manages the business operations of the sale and distribution of isotopes.

162

Improving Home Automation by Discovering Regularly Occurring Device Usage Patterns  

E-Print Network [OSTI]

Improving Home Automation by Discovering Regularly Occurring Device Usage Patterns Edwin O in an environment can be mined to discover significant patterns, which an intelligent agent could use to automate of two prediction algorithms, thus demonstrating multiple uses for a home automation system. Finally, we

Cook, Diane J.

163

PURDUE EXTENSION Stormwater is the runoff that occurs during  

E-Print Network [OSTI]

PURDUE EXTENSION FNR-256 Stormwater is the runoff that occurs during rainstorms. In natural systems, rainwater is absorbed by the soil or plants on the ground. In a human dominated landscape, impervious surfaces, such as rooftops, driveways, streets, and parking lots, simply divert this rainwater down

164

Isotope Cancer Treatment Research at LANL  

ScienceCinema (OSTI)

Los Alamos National Laboratory has produced medical isotopes for diagnostic and imaging purposes for more than 30 years. Now LANL researchers have branched out into isotope cancer treatment studies. New results show that an accelerator-based approach can produce clinical trial quantities of actinium-225, an isotope that has promise as a way to kill tumors without damaging surrounding healthy cells.

Weidner, John; Nortier, Meiring

2014-06-02T23:59:59.000Z

165

Testing atomic mass models with radioactive beams  

SciTech Connect (OSTI)

Significantly increased yields of new or poorly characterized exotic isotopes that lie far from beta-decay stability can be expected when radioactive beams are used to produce these nuclides. Measurements of the masses of these new species are very important. Such measurements are motivated by the general tendency of mass models to diverge from one another upon excursions from the line of beta-stability. Therefore in these regions (where atomic mass data are presently nonexistent or sparse) the models can be tested rigorously to highlight the features that affect the quality of their short-range and long-range extrapolation properties. Selection of systems to study can be guided, in part, by a desire to probe those mass regions where distinctions among mass models are most apparent and where yields of exotic isotopes, produced via radioactive beams, can be optimized. Identification of models in such regions that have good predictive properties will aid materially in guiding the selection of additional experiments which ultimately will provide expansion of the atomic mass database for further refinement of the mass models. 6 refs., 5 figs.

Haustein, P.E.

1989-01-01T23:59:59.000Z

166

Proton Radioactivity Measurements at HRIBF: Ho, Lu, and Tm Isotopes  

SciTech Connect (OSTI)

Two new isotopes, {sup 145}Tm and {sup 140}Ho and three isomers in previously known isotopes, {sup 141m}Ho, {sup 150m}Lu and {sup 151m}Lu have been discovered and studied via their decay by proton emission. These proton emitters were produced at the Holifield Radioactive Ion Beam Facility (HRIBF) by heavy-ion fusion-evaporation reactions, separated in A/Q with a recoil mass spectrometer (RMS), and detected in a double-sided silicon strip detector (DSSD). The decay energy and half-life was measured for each new emitter. An analysis in terms of a spherical shell model is applied to the Tm and Lu nuclei, but Ho is considerably deformed and requires a collective model interpretation.

Akovali, Y.; Batchelder, J.C.; Bingham, C.R.; Davinson, T.; Ginter, T.N.; Gross, C.J.; Grzywacz, R.; Hamilton, J.H.; Janas, Z.; Karny, M.; Kim, S.H.; MacDonald, B.D.; Mas, J.F.; McConnell, J.W.; Piechaczek, A.; Ressler, J.J.; Rykaczewski, K.; Slinger, R.C.; Szerypo, J.; Toth, K.S.; Weintraub, W.; Woods, P.J.; Yu, C.-H.; Zganjar, E.F.

1998-11-13T23:59:59.000Z

167

Isotope separation with the RICH detector of the AMS Experiment  

E-Print Network [OSTI]

The Alpha Magnetic Spectrometer (AMS), to be installed on the International Space Station (ISS) in 2008, is a cosmic ray detector with several subsystems, one of which is a proximity focusing Ring Imaging Cherenkov (RICH) detector. This detector will be equipped with a dual radiator (aerogel+NaF), a lateral conical mirror and a detection plane made of 680 photomultipliers and light guides, enabling precise measurements of particle electric charge and velocity. Combining velocity measurements with data on particle rigidity from the AMS Tracker it is possible to obtain a measurement for particle mass, allowing the separation of isotopes. A Monte Carlo simulation of the RICH detector, based on realistic properties measured at ion beam tests, was performed to evaluate isotope separation capabilities. Results for three elements -- H (Z=1), He (Z=2) and Be (Z=4) -- are presented.

Arruda, Luísa; Borges, João; Carmo, Fernando; Gonçalves, Patrícia; Pereira, Rui; Pimenta, Mário

2007-01-01T23:59:59.000Z

168

Ultra-low Q values for neutrino mass measurements  

SciTech Connect (OSTI)

We investigate weak nuclear decays with extremely small kinetic energy release (Q value) and thus extremely good sensitivity to the absolute neutrino mass scale. In particular, we consider decays into excited daughter states, and we show that partial ionization of the parent atom can help to tune Q values to << 1 keV. We discuss several candidate isotopes undergoing {beta}{sup {+-}}, bound state {beta}, or electron capture decay, and come to the conclusion that a neutrino mass measurement using low-Q decays might only be feasible if no ionization is required, and if future improvements in isotope production technology, nuclear mass spectroscopy, and atomic structure calculations are possible. Experiments using ions, however, are extremely challenging due to the large number of ions that must be stored. New precision data on nuclear excitation levels could help to identify further isotopes with low-Q decay modes and possibly less challenging requirements.

Kopp, Joachim; /Heidelberg, Max Planck Inst. /Fermilab; Merle, Alexander; /Heidelberg, Max Planck Inst.

2009-11-01T23:59:59.000Z

169

Feasibility study of plutonium isotopic analysis of resin beads by nondestructive gamma-ray spectroscopy  

SciTech Connect (OSTI)

We have initiated a feasibility study on the use of nondestructive low-energy gamma-ray spectroscopy for plutonium isotopic analysis on resin beads. Seven resin bead samples were measured, with each sample containing an average of 9 ..mu..g of plutonium; the isotopic compositions of the samples varied over a wide range. The gamma-ray spectroscopy results, obtained from 4-h counting-time measurements, were compared with mass spectrometry results. The average ratios of gamma-ray spectroscopy to mass spectrometry were 1.014 +- 0.025 for /sup 238/Pu//sup 239/Pu, 0.996 +- 0.018 for /sup 240/Pu//sup 239/Pu, and 0.980 +- 0.038 for /sup 241/Pu//sup 239/Pu. The rapid, automated, and accurate nondestructive isotopic analysis of resin beads may be very useful to process technicians and International Atomic Energy Agency inspectors. 3 refs., 1 fig., 3 tabs.

Li, T.K.

1985-01-01T23:59:59.000Z

170

Hydrogen Cylinder Storage Array Explosion Evaluations at the High Flux Isotope Reactor  

SciTech Connect (OSTI)

The safety analysis for a recently-installed cold neutron source at the High Flux Isotope Reactor (HFIR) involved evaluation of potential explosion consequences from accidental hydrogen jet releases that could occur from an array of hydrogen cylinders. The scope of the safety analysis involved determination of the release rate of hydrogen, the total quantity of hydrogen assumed to be involved in the explosion, the location of an ignition point or center of the explosion from receptors of interest, and the peak overpressure at the receptors. To evaluate the total quantity of hydrogen involved in the explosion, a 2D model was constructed of the jet concentration and a radial-axial integral over the jet cloud from the centerline to the flammability limit of 4% was used to determine the hydrogen mass to be used as a source term. The location of the point source was chosen as the peak of the jet centerline concentration profile. Consequences were assessed using a combination of three methods for estimating local overpressure as a function of explosion source strength and distance: the Baker-Strehlow method, the TNT-equivalence method, and the TNO method. Results from the explosions were assessed using damage estimates in screening tables for buildings and industrial equipment.

Cook, David Howard [ORNL] [ORNL; Griffin, Frederick P [ORNL] [ORNL; Hyman III, Clifton R [ORNL] [ORNL

2010-01-01T23:59:59.000Z

171

Naturally occurring crystalline phases: analogues for radioactive waste forms  

SciTech Connect (OSTI)

Naturally occurring mineral analogues to crystalline phases that are constituents of crystalline radioactive waste forms provide a basis for comparison by which the long-term stability of these phases may be estimated. The crystal structures and the crystal chemistry of the following natural analogues are presented: baddeleyite, hematite, nepheline; pollucite, scheelite;sodalite, spinel, apatite, monazite, uraninite, hollandite-priderite, perovskite, and zirconolite. For each phase in geochemistry, occurrence, alteration and radiation effects are described. A selected bibliography for each phase is included.

Haaker, R.F.; Ewing, R.C.

1981-01-01T23:59:59.000Z

172

High-precision optical measurements of 13 isotope ratios in organic compounds at  

E-Print Network [OSTI]

range with an average precision of 0.95 and 0.67 for ethane and propane, respec- tively. The calibrated accuracy for methane, ethane, and propane is within 3 of the values determined using isotope ratio mass place in chemistry, especially in geochemistry, for determining reaction mechanisms and pro- viding

Zare, Richard N.

173

Current Direct Neutrino Mass Experiments  

E-Print Network [OSTI]

In this contribution we review the status and perspectives of direct neutrino mass experiments. These experiments investigate the kinematics of $\\beta$-decays of specific isotopes ($^3$H, $^{187}$Re, $^{163}$Ho) to derive model-independent information on the averaged electron (anti-) neutrino mass, which is formed by the incoherent sum of the neutrino mass eigenstates contributing to the electron neutrino. We first review the kinematics of $\\beta$-decay and the determination of the neutrino mass, before giving a brief overview of past neutrino mass measurements (SN1987a-ToF studies, Mainz and Troitsk experiments for $^3$H, cryo-bolometers for $^{187}$Re). We then describe the Karlsruhe Tritium Neutrino (KATRIN) experiment which is currently under construction at Karlsruhe Institute of Technology. The large-scale setup will use the MAC-E-Filter principle pioneered earlier to push the sensitivity down to a value of 200 meV(90% C.L.). KATRIN faces many technological challenges that have to be resolved with regar...

Drexlin, G; Mertens, S; Weinheimer, C

2013-01-01T23:59:59.000Z

174

Measurement of Ultra-Low Potassium Contaminations with Accelerator Mass Spectrometry  

E-Print Network [OSTI]

Levels of trace radiopurity in active detector materials is a subject of major concern in low-background experiments. Among the radio-isotopes, $\\k40$ is one of the most abundant and yet whose signatures are difficult to reject. Procedures were devised to measure trace potassium concentrations in the inorganic salt CsI as well as in organic liquid scintillator (LS) with Accelerator Mass Spectrometry (AMS), giving, respectively, the $\\k40$-contamination levels of $\\sim 10^{-10}$ and $\\sim 10^{-13}$ g/g. Measurement flexibilities and sensitivities are improved over conventional methods. The projected limiting sensitivities if no excess of potassium signals had been observed over background are $8 \\times 10^{-13}$ g/g and $3 \\times 10^{-17}$ g/g for the CsI and LS, respectively. Studies of the LS samples indicate that the radioactive contaminations come mainly in the dye solutes, while the base solvents are orders of magnitude cleaner. The work demonstrate the possibilities of measuring naturally-occurring isotopes with the AMS techniques.

K. J. Dong

2007-05-01T23:59:59.000Z

175

Management of Naturally Occurring Radioactive Materials (NORM) in Canada  

SciTech Connect (OSTI)

In Canada, nuclear and radiological regulatory responsibilities are shared between the provinces/territories and the federal government. The Canadian Nuclear Safety Commission (CNSC) regulates nuclear fuel cycle materials and man-made radionuclides under the Nuclear Safety and Control Act (2000). The provinces and territories regulate NORM arising from industrial activities, not involving the nuclear fuel cycle materials. Present guideline--Canadian Guidelines for the Management of Naturally Occurring Radioactive Materials (NORM)--was published in 2000 in order to bring uniformity to the management of NORM-related procedures to provide adequate radiation protection for workers and the general public. The basic premise of these guidelines is that the NORM-related activities should not be posing any greater hazard than those activities regulated under the Nuclear Safety and Control Act; these concepts are described in this paper.

Baweja, Anar S.; Tracy, Bliss L. [Radiation Protection Bureau, Health Canada, Ottawa, Ontario (Canada)

2008-08-07T23:59:59.000Z

176

Heat and mass exchanger  

DOE Patents [OSTI]

A mass and heat exchanger includes at least one first substrate with a surface for supporting a continuous flow of a liquid thereon that either absorbs, desorbs, evaporates or condenses one or more gaseous species from or to a surrounding gas; and at least one second substrate operatively associated with the first substrate. The second substrate includes a surface for supporting the continuous flow of the liquid thereon and is adapted to carry a heat exchange fluid therethrough, wherein heat transfer occurs between the liquid and the heat exchange fluid.

Lowenstein, Andrew (Princeton, NJ); Sibilia, Marc J. (Princeton, NJ); Miller, Jeffrey A. (Hopewell, NJ); Tonon, Thomas (Princeton, NJ)

2007-09-18T23:59:59.000Z

177

Heat and mass exchanger  

DOE Patents [OSTI]

A mass and heat exchanger includes at least one first substrate with a surface for supporting a continuous flow of a liquid thereon that either absorbs, desorbs, evaporates or condenses one or more gaseous species from or to a surrounding gas; and at least one second substrate operatively associated with the first substrate. The second substrate includes a surface for supporting the continuous flow of the liquid thereon and is adapted to carry a heat exchange fluid therethrough, wherein heat transfer occurs between the liquid and the heat exchange fluid.

Lowenstein, Andrew (Princeton, NJ); Sibilia, Marc J. (Princeton, NJ); Miller, Jeffrey A. (Hopewell, NJ); Tonon, Thomas (Princeton, NJ)

2011-06-28T23:59:59.000Z

178

Carbon dioxide emissions from fossil fuel consumption and cement manufacture, 1751-1991; and an estimate of their isotopic composition and latitudinal distribution  

SciTech Connect (OSTI)

This work briefly discusses four of the current research emphases at Oak Ridge National Laboratory regarding the emission of carbon dioxide (CO{sub 2}) from fossil fuel consumption, natural gas flaring and cement manufacture. These emphases include: (1) updating the 1950 to present time series of CO{sub 2} emissions from fossil fuel consumption and cement manufacture, (2) extending this time series back to 1751, (3) gridding the data at 1{sup 0} by 1{sup 0} resolution, and (4) estimating the isotopic signature of these emissions. In 1991, global emissions of CO{sub 2} from fossil fuel and cement increased 1.5% over 1990 levels to 6188 {times} 10{sup 6} metric tonnes C. The Kuwaiti oil fires can account for all of the increase. Recently published energy data (Etemad et al., 1991) allow extension of the CO emissions time series back to 1751. Preliminary examination shows good agreement with two other, but shorter, energy time series. A latitudinal distribution of carbon emissions is being completed. A southward shift in the major mass of CO{sub 2} emissions is occurring from European-North American latitudes towards central-southeast Asian latitudes, reflecting the growth of population and industrialization at these lower latitudes. The carbon isotopic signature of these emissions has been re-examined. The emissions of the last two decades are approximately 1{per_thousand} lighter than previously reported (Tans, 1981). This lightening of the emissions signature is due to fossil fuel gases and liquids, including a revision of their {delta}{sup 13}C isotopic signature and an increased production rate.

Andres, R.J.; Marland, G.; Boden, T.; Bischof, S.

1994-10-01T23:59:59.000Z

179

Neutrinoless Double Beta Decay and Neutrino Masses  

E-Print Network [OSTI]

Neutrinoless double beta decay is a promising test for lepton number violating physics beyond the standard model of particle physics. There is a deep connection between this decay and the phenomenon of neutrino masses. In particular, we will discuss the relation between neutrinoless double beta decay and Majorana neutrino masses provided by the so-called Schechter--Valle theorem in a quantitative way. Furthermore, we will present an experimental cross check to discriminate neutrinoless double beta decay from unknown nuclear background using only one isotope, i.e., within one experiment.

Michael Duerr

2012-06-04T23:59:59.000Z

180

Neutrinoless double beta decay and neutrino masses  

SciTech Connect (OSTI)

Neutrinoless double beta decay (0{nu}{beta}{beta}) is a promising test for lepton number violating physics beyond the standard model (SM) of particle physics. There is a deep connection between this decay and the phenomenon of neutrino masses. In particular, we will discuss the relation between 0{nu}{beta}{beta} and Majorana neutrino masses provided by the so-called Schechter-Valle theorem in a quantitative way. Furthermore, we will present an experimental cross check to discriminate 0{nu}{beta}{beta} from unknown nuclear background using only one isotope, i.e., within one experiment.

Duerr, Michael [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany)

2012-07-27T23:59:59.000Z

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Atom trap trace analysis of krypton isotopes  

SciTech Connect (OSTI)

A new method of ultrasensitive isotope trace analysis has been developed. This method, based on the technique of laser manipulation of neutral atoms, has been used to count individual {sup 85}Kr and {sup 81}Kr atoms present in a natural krypton gas sample with isotopic abundances in the range of 10{sup {minus}11} and 10{sup {minus}13}, respectively. This method is free of contamination from other isotopes and elements and can be applied to several different isotope tracers for a wide range of applications. The demonstrated detection efficiency is 1 x 10{sup {minus}7}. System improvements could increase the efficiency by many orders of magnitude.

Bailey, K.; Chen, C. Y.; Du, X.; Li, Y. M.; Lu, Z.-T.; O'Connor, T. P.; Young, L.

1999-11-17T23:59:59.000Z

182

Integration of Nontraditional Isotopic Systems Into Reaction...  

Broader source: Energy.gov (indexed) [DOE]

minerals in geothermal systems (feldspars, epidote, and calcite) often control fracture permeability changes. Measurements of Ca and Sr isotopic fractionation at high...

183

Stable Isotope Protocols: Sampling and Sample Processing  

E-Print Network [OSTI]

plants, benthic microalgae [BMI], benthic macroalgae) andin a dessicator, prior to analysis. A.2 Benthic microalgaeBenthic microalgae (BMI) can be collected for isotope

Levin, Lisa A; Currin, Carolyn

2012-01-01T23:59:59.000Z

184

Integration of Nontraditional Isotopic Systems Into Reaction...  

Broader source: Energy.gov (indexed) [DOE]

of EGS For Exploration, Evaluation of Water-Rock Interaction, and Impacts of Water Chemistry on Reservoir Sustainability Integration of Nontraditional Isotopic Systems Into...

185

Gamma Spectrum from Neutron Capture on Tungsten Isotopes  

E-Print Network [OSTI]

FROM NEUTRON CAPTURE ON TUNGSTEN ISOTOPES A. M. HURST ?1,2 ,capture on the stable tungsten isotopes is presented, withknown decay schemes of the tungsten isotopes from neutron

Hurst, Aaron

2011-01-01T23:59:59.000Z

186

Isotopes Tell Origin and Operation of the Sun  

E-Print Network [OSTI]

The Iron Sun formed on the collapsed core of a supernova and now acts as a magnetic plasma diffuser, as did the precursor star, separating ions by mass. This process covers the solar surface with lightweight elements and with lighter isotopes of each element. Running difference images expose rigid, iron-rich structures below the fluid photosphere made of lightweight elements. The energy source for the Sun and ordinary stars seems to be neutron-emission and neutron-decay, with partial fusion of the decay product, rather than simple fusion of hydrogen into helium or heavier elements. Neutron-emission from the solar core and neutron-decay generate about sixty five percent of solar luminosity and H-fusion generates about thirty-five percent. The upward flow of H ions maintains mass-separation in the Sun. Only about one percent of this neutron decay product survives its upward journey to depart as solar-wind hydrogen.

O. Manuel; Sumeet A. Kamat; Michael Mozina

2005-09-28T23:59:59.000Z

187

Spatial periphery of lithium isotopes  

SciTech Connect (OSTI)

The spatial structure of lithium isotopes is studied with the aid of the charge-exchange and (t, p) reactions on lithium nuclei. It is shown that an excited isobaric-analog state of {sup 6}Li (0{sup +}, 3.56MeV) has a halo structure formed by a proton and a neutron, that, in the {sup 9}Li nucleus, there is virtually no neutron halo, and that {sup 11}Li is a Borromean nucleus formed by a {sup 9}Li core and a two-neutron halo manifesting itself in cigar-like and dineutron configurations.

Galanina, L. I., E-mail: galan_lidiya@mail.ru; Zelenskaja, N. S. [Moscow State University, Skobeltsyn Institute of Nuclear Physics (Russian Federation)

2013-12-15T23:59:59.000Z

188

Electroplating method for producing ultralow-mass fissionable deposits  

DOE Patents [OSTI]

A method for producing ultralow-mass fissionable deposits for nuclear reactor dosimetry is described, including the steps of holding a radioactive parent until the radioactive parent reaches secular equilibrium with a daughter isotope, chemically separating the daughter from the parent, electroplating the daughter on a suitable substrate, and holding the electroplated daughter until the daughter decays to the fissionable deposit.

Ruddy, Francis H. (Monroeville, PA)

1989-01-01T23:59:59.000Z

189

Introduction The Sun is a mass of incandescent gas  

E-Print Network [OSTI]

Chapter 1 Introduction The Sun is a mass of incandescent gas A gigantic nuclear furnace Building that our bodies contain atoms that, like most elements and their isotopes in the Solar System, were part of the molecular cloud from which the Solar System condensed, and were trapped in primitive

Nittler, Larry R.

190

Manufactured Home Testing in Simulated and Naturally Occurring High Winds  

SciTech Connect (OSTI)

A typical double-wide manufactured home was tested in simulated and naturally occurring high winds to understand structural behavior and improve performance during severe windstorms. Seven (7) lateral load tests were conducted on a double-wide manufactured home at a remote field test site in Wyoming. An extensive instrumentation package monitored the overall behavior of the home and collected data vital to validating computational software for the manufactured housing industry. The tests were designed to approach the design load of the home without causing structural damage, thus allowing the behavior of the home to be accessed when the home was later exposed to high winds (to 80-mph). The data generally show near-linear initial system response with significant non-linear behavior as the applied loads increase. Load transfer across the marriage line is primarily compression. Racking, while present, is very small. Interface slip and shear displacement along the marriage line are nearly insignificant. Horizontal global displacements reached 0.6 inch. These tests were designed primarily to collect data necessary to calibrate a desktop analysis and design software tool, MHTool, under development at the Idaho National Laboratory specifically for manufactured housing. Currently available analysis tools are, for the most part, based on methods developed for “stick built” structures and are inappropriate for manufactured homes. The special materials utilized in manufactured homes, such as rigid adhesives used in the connection of the sheathing materials to the studs, significantly alter the behavior of manufactured homes under lateral loads. Previous full scale tests of laterally loaded manufactured homes confirm the contention that conventional analysis methods are not applicable. System behavior dominates the structural action of manufactured homes and its prediction requires a three dimensional analysis of the complete unit, including tiedowns. This project was sponsored by the US Department of Energy, US Department of Housing and Urban Development, and the Manufactured Housing Institute. The results of this research can lead to savings in annual losses of life and property by providing validated information to enable the advancement of code requirements and by developing engineering software that can predict and optimize wind resistance.

W. D. Richins; T. K. Larson

2006-08-01T23:59:59.000Z

191

Isotopic Analysis- Fluid At Dixie Valley Geothermal Area (Kennedy...  

Open Energy Info (EERE)

permeable fluid flow pathways and the helium Isotopic composition of the surface fluids. The authors suggest that helium isotopes are the best and possibly the only...

192

CRAD, Engineering - Oak Ridge National Laboratory High Flux Isotope...  

Broader source: Energy.gov (indexed) [DOE]

Oak Ridge National Laboratory High Flux Isotope Reactor CRAD, Engineering - Oak Ridge National Laboratory High Flux Isotope Reactor February 2007 A section of Appendix C to DOE G...

193

CRAD, Maintenance - Oak Ridge National Laboratory High Flux Isotope...  

Broader source: Energy.gov (indexed) [DOE]

Maintenance - Oak Ridge National Laboratory High Flux Isotope Reactor CRAD, Maintenance - Oak Ridge National Laboratory High Flux Isotope Reactor February 2007 A section of...

194

CRAD, Engineering - Oak Ridge National Laboratory High Flux Isotope...  

Broader source: Energy.gov (indexed) [DOE]

Engineering - Oak Ridge National Laboratory High Flux Isotope Reactor Contractor ORR CRAD, Engineering - Oak Ridge National Laboratory High Flux Isotope Reactor Contractor ORR...

195

CRAD, Maintenance - Oak Ridge National Laboratory High Flux Isotope...  

Broader source: Energy.gov (indexed) [DOE]

Maintenance - Oak Ridge National Laboratory High Flux Isotope Reactor Contractor ORR CRAD, Maintenance - Oak Ridge National Laboratory High Flux Isotope Reactor Contractor ORR...

196

CRAD, Management- Oak Ridge National Laboratory High Flux Isotope...  

Broader source: Energy.gov (indexed) [DOE]

Management- Oak Ridge National Laboratory High Flux Isotope Reactor CRAD, Management- Oak Ridge National Laboratory High Flux Isotope Reactor February 2007 A section of Appendix C...

197

Enriched Stable Isotope Materials and Chemistry | ornl.gov  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Enriched Stable Isotope Materials and Chemistry SHARE Enriched Stable Isotope Materials and Chemistry Reductiondistillation of calcium-48 metal valued at over 900,000. An...

198

Fractionation of Oxygen Isotopes in Phosphate during its Interactions...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Fractionation of Oxygen Isotopes in Phosphate during its Interactions with Iron Oxides. Fractionation of Oxygen Isotopes in Phosphate during its Interactions with Iron Oxides....

199

applied isotope techniques: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

M. 22 Applied Radiation and Isotopes 55 (2001) 707713 Bronchial dosimeter for radon progeny Biology and Medicine Websites Summary: Applied Radiation and Isotopes 55 (2001)...

200

Investigation of high temperature gaseous species by Knudsen cell mass spectrometry above the condensed systems Cu-Y-Ru-C, Ag-Y-Ru-C, and Au-Y- Ru-C  

E-Print Network [OSTI]

of the total ion intensities listed in Tables 2 through 5, + + except those for RuC and YC2, were calculated by dividing the individual isotopic species by the isotopic abundance of that species according to Equation 1, where I is the total intensity of all... not be used because their mass to charge ratios overlap. For these iona, an + algebraic equation was used which compared the ratios of YC (Mass 113), YC2 (Mass 114), RuC (Mass 113), and RuC (Mass 114). The + + + calculated isotopic abundances...

Wilhite, Dale Wayne

1988-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

The Quest for the Heaviest Uranium Isotope  

E-Print Network [OSTI]

We study Uranium isotopes and surrounding elements at very large neutron number excess. Relativistic mean field and Skyrme-type approaches with different parametrizations are used in the study. Most models show clear indications for isotopes that are stable with respect to neutron emission far beyond N=184 up to the range of around N=258.

S. Schramm; D. Gridnev; D. V. Tarasov; V. N. Tarasov; W. Greiner

2012-01-17T23:59:59.000Z

202

Isotope separation by selective photodissociation of glyoxal  

DOE Patents [OSTI]

Dissociation products, mainly formaldehyde and carbon monoxide, enriched in a desired isotope of carbon, oxygen, or hydrogen are obtained by the selective photodissociation of glyoxal wherein glyoxal is subjected to electromagnetic radiation of a predetermined wavelength such that photon absorption excites and induces dissociation of only those molecules of glyoxal containing the desired isotope.

Marling, John B. (Pleasanton, CA)

1976-01-01T23:59:59.000Z

203

Geochemical and carbon isotopic studies of crude oil destruction, bitumen precipitation, and sulfate reduction in the deep Smackover Formation  

SciTech Connect (OSTI)

Crude oil generated by the Lower Smackover source facies migrated to Upper Smackover reservoirs where slow thermal cracking of crude oil resulted in the formation of gas-condensate and late solid bitumen. Ultimately, only pyrobitumen, methane, and nonhydrocarbon gases including hydrogen sulfide persist in the deepest Smackover reservoirs. The carbon isotopic compositions of crude oils became heavier during crude oil destruction. The carbon isotopic compositions of asphaltenes, NSO-compounds, and saturated hydrocarbons in late solid bitumen and the Lower Smackover source facies became isotopically lighter during crude oil destruction. It is suggested that some isotopically-light components from crude oils were incorporated in late solid bitumen by reactions involving thermochemical sulfate reduction. Thermochemical sulfate reduction and crude oil destruction occurred over a long span of geologic time at temperatures in the 120-150C range.

Sassen, R. (Louisiana State Univ., Baton Rouge (USA))

1988-01-01T23:59:59.000Z

204

Isotopes  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

are saving lives, advancing cutting-edge research and keeping the U.S. safe. Strontium-82 produced at Los Alamos is used in hospitals nation- and world-wide for critical...

205

ISOTOPES  

E-Print Network [OSTI]

1955). Production of Heavy water, 37. G.M. Keyser, D.B.Economy of Production of Heavy Water, Turin, Italy (1970),world production of heavy water to ~1ay, 1977. From data

Lederer, C. Michael

2013-01-01T23:59:59.000Z

206

ISOTOPES  

E-Print Network [OSTI]

constructed to enrich liquid UF6 slightly as feed for thej) b. Optimum a. s: .X. UF6 feed, (kg per year) XBL 7912 -

Lederer, C. Michael

2013-01-01T23:59:59.000Z

207

Isotopes  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFunInfrared LandResponsesIon/SurfacePump-Testing Sign

208

ISOTOPES  

E-Print Network [OSTI]

5-7. 1975, British Nuclear Engineering Society (1975). 87.London, March British Nuclear Engineering Society (1975).T.H. Pigford, Nuclear Chemical Engineering (1St edition),

Lederer, C. Michael

2013-01-01T23:59:59.000Z

209

Atomic vapor laser isotope separation of lead-210 isotope  

DOE Patents [OSTI]

An isotopically selective laser process and apparatus for removal of Pb-210 from natural lead that involves a one-photon near-resonant, two-photon resonant excitation of one or more Rydberg levels, followed by field ionization and then electrostatic extraction. The wavelength to the near-resonant intermediate state is counter propagated with respect to the second wavelength required to populate the final Rydberg state. This scheme takes advantage of the large first excited state cross section, and only modest laser fluences are required. The non-resonant process helps to avoid two problems: first, stimulated Raman Gain due to the nearby F=3/2 hyperfine component of Pb-207 and, second, direct absorption of the first transition process light by Pb-207.

Scheibner, Karl F. (Tracy, CA); Haynam, Christopher A. (Pleasanton, CA); Johnson, Michael A. (Pleasanton, CA); Worden, Earl F. (Diablo, CA)

1999-01-01T23:59:59.000Z

210

Atomic vapor laser isotope separation of lead-210 isotope  

DOE Patents [OSTI]

An isotopically selective laser process and apparatus for removal of Pb-210 from natural lead that involves a one-photon near-resonant, two-photon resonant excitation of one or more Rydberg levels, followed by field ionization and then electrostatic extraction. The wavelength to the near-resonant intermediate state is counter propagated with respect to the second wavelength required to populate the final Rydberg state. This scheme takes advantage of the large first excited state cross section, and only modest laser fluences are required. The non-resonant process helps to avoid two problems: first, stimulated Raman Gain due to the nearby F=3/2 hyperfine component of Pb-207 and, second, direct absorption of the first transition process light by Pb-207. 5 figs.

Scheibner, K.F.; Haynam, C.A.; Johnson, M.A.; Worden, E.F.

1999-08-31T23:59:59.000Z

211

RAPID FUSION METHOD FOR DETERMINATION OF PLUTONIUM ISOTOPES IN LARGE RICE SAMPLES  

SciTech Connect (OSTI)

A new rapid fusion method for the determination of plutonium in large rice samples has been developed at the Savannah River National Laboratory (Aiken, SC, USA) that can be used to determine very low levels of plutonium isotopes in rice. The recent accident at Fukushima Nuclear Power Plant in March, 2011 reinforces the need to have rapid, reliable radiochemical analyses for radionuclides in environmental and food samples. Public concern regarding foods, particularly foods such as rice in Japan, highlights the need for analytical techniques that will allow very large sample aliquots of rice to be used for analysis so that very low levels of plutonium isotopes may be detected. The new method to determine plutonium isotopes in large rice samples utilizes a furnace ashing step, a rapid sodium hydroxide fusion method, a lanthanum fluoride matrix removal step, and a column separation process with TEVA Resin? cartridges. The method can be applied to rice sample aliquots as large as 5 kg. Plutonium isotopes can be determined using alpha spectrometry or inductively-coupled plasma mass spectrometry (ICP-MS). The method showed high chemical recoveries and effective removal of interferences. The rapid fusion technique is a rugged sample digestion method that ensures that any refractory plutonium particles are effectively digested. The MDA for a 5 kg rice sample using alpha spectrometry is 7E-5 mBq g{sup -1}. The method can easily be adapted for use by ICP-MS to allow detection of plutonium isotopic ratios.

Maxwell, S.

2013-03-01T23:59:59.000Z

212

Light stable isotope study of the Roosevelt Hot Springs thermal area, Southwestern Utah  

SciTech Connect (OSTI)

The isotopic composition of hydrogen, oxygen, and carbon has been determined for regional cold springs, thermal fluids, and rocks and minerals from the Roosevelt Hot Springs thermal area. The geothermal system has developed within plutonic granitic rocks and amphibolite facies gneiss, relying upon fracture-controlled permeability for the migration of the thermal fluids. Probably originating as meteoric waters in the upper elevations of the Mineral Mountains, the thermal waters sampled in the production wells display an oxygen isotopic shift of at least +1.2. Depletions of delta /sup 18/O in wole rock, K-feldspar, and biotite have a positive correlation with alteration intensity. W/R mass ratios, calculated from the isotopic shifts of rock and water, range up to 3.0 in a producing horizon of one well, although the K-feldspar has experienced only 30% exchange with the thermal waters. While veinlet quartz has equilibrated with the thermal waters, the /sup 18/O values of K-mica clay, an alteration product of plagioclase, mimic the isotopic composition of K-feldspar and whole rock. This suggests that locally small W/R ratios enable plagioclase to influence its alteration products by isotopic exchange.

Rohrs D.T.; Bowman, J.R.

1980-05-01T23:59:59.000Z

213

Prediction of equilibrium Li isotope fractionation between minerals and aqueous solutions at high P and T: an efficient ab initio approach  

E-Print Network [OSTI]

The mass-dependent equilibrium stable isotope fractionation between different materials is an important geochemical process. Here we present an efficient method to compute the isotope fractionation between complex minerals and fluids at high pressure, P, and temperature, T, representative for the Earth's crust and mantle. The method is tested by computation of the equilibrium fractionation of lithium isotopes between aqueous fluids and various Li bearing minerals such as staurolite, spodumene and mica. We are able to correctly predict the direction of the isotope fractionation as observed in the experiments. On the quantitative level the computed fractionation factors agree within 1.0 permil with the experimental values indicating predictive power of ab initio methods. We show that with ab initio methods we are able to investigate the underlying mechanisms driving the equilibrium isotope fractionation process, such as coordination of the fractionating elements, their bond strengths to the neighboring atoms, c...

Kowalski, Piotr M

2011-01-01T23:59:59.000Z

214

Theory of the helium isotope shift  

E-Print Network [OSTI]

Theory of the isotope shift of the centroid energies of light few-electron atoms is reviewed. Numerical results are presented for the isotope shift of the $2^3P$-$2^3S$ and $2^1S$-$2^3S$ transition energies of $^3$He and $^4$He. By comparing theoretical predictions for the isotope shift with the experimental results, the difference of the squares of the nuclear charge radii of $^3$He and $^4$He, $\\delta R^2$, is determined with high accuracy.

Yerokhin, Vladimir A

2015-01-01T23:59:59.000Z

215

Influence of longitudinal isotope substitution on the thermal conductivity of carbon nanotubes: Results of nonequilibrium molecular dynamics and local density functional calculations  

SciTech Connect (OSTI)

We report reverse nonequilibrium molecular dynamics calculations of the thermal conductivity of isotope substituted (10,10) carbon nanotubes (CNTs) at 300 K. {sup 12}C and {sup 14}C isotopes both at 50% content were arranged either randomly, in bands running parallel to the main axis of the CNTs or in bands perpendicular to this axis. It is found that the systems with randomly distributed isotopes yield significantly reduced thermal conductivity. In contrast, the systems where the isotopes are organized in patterns parallel to the CNTs axis feature no reduction in thermal conductivity when compared with the pure {sup 14}C system. Moreover, a reduction of approximately 30% is observed in the system with the bands of isotopes running perpendicular to the CNT axis. The computation of phonon dispersion curves in the local density approximation and classical densities of vibrational states reveal that the phonon structure of carbon nanotubes is conserved in the isotope substituted systems with the ordered patterns, yielding high thermal conductivities in spite of the mass heterogeneity. In order to complement our conclusions on the {sup 12}C-{sup 14}C mixtures, we computed the thermal conductivity of systems where the {sup 14}C isotope was turned into pseudo-atoms of 20 and 40 atomic mass units.

Leroy, Frédéric, E-mail: f.leroy@theo.chemie.tu-darmstadt.de; Böhm, Michael C., E-mail: boehm@theo.chemie.tu-darmstadt.de [Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Technische Universität Darmstadt, D-64287 Darmstadt (Germany); Schulte, Joachim [Bruker Biospin GmbH, Silberstreifen, D-76287 Rheinstetten (Germany)] [Bruker Biospin GmbH, Silberstreifen, D-76287 Rheinstetten (Germany); Balasubramanian, Ganesh [Department of Mechanical Engineering, Iowa State University, Ames, Iowa 50011 (United States)] [Department of Mechanical Engineering, Iowa State University, Ames, Iowa 50011 (United States)

2014-04-14T23:59:59.000Z

216

Measurement of the (3s3p){sup 1}P-(3s3d){sup 1}D isotope shift in Mg i  

SciTech Connect (OSTI)

We present measurements of the isotope shift for the (3s3p){sup 1}P-(3s3d){sup 1}D transitions at 881 nm in Mg i. The three stable magnesium isotopes yielded a shift {sup 24}Mg-{sup 25}Mg of (1342{+-}20) MHz and {sup 25}Mg-{sup 26}Mg of (1175{+-}23) MHz. Measured shifts are consistent with recent relativistic many-body calculations of the mass effect.

Steenstrup, M. P.; Brusch, A.; Jensen, B. B.; Thomsen, J. W. [Niels Bohr Institute, Universitetsparken 5, DK-2100 Copenhagen (Denmark); Hald, J. [Danish Fundamental Metrology, Matematiktorvet 307, DK-2008 Kgs. Lyngby (Denmark)

2010-11-15T23:59:59.000Z

217

Mass-spectrometric determination of americium and curium in spent nuclear fuel  

SciTech Connect (OSTI)

It was shown that it is possible to carry out isotopic analysis of americium and curium isolated in one fraction from a sample of nuclear fuel without chemical separation of the elements. This became possible as a result of the use in the mass-spectrometric measurements of a highly efficient ion source with surface ionization in a partially closed cavity. With this ion source, the content of americium and curium in nuclear fuel was determined by isotope dilution.

Kalygin, V.V.; Gabeskiriya, V.Ya.

1987-01-01T23:59:59.000Z

218

COMMENTS ON ANOMALOUS EFFECTS IN CHARGING OF PD POWDERS WITH HIGH DENSITY HYDROGEN ISOTOPES  

SciTech Connect (OSTI)

In Kitamura, et al, Pd-containing materials are exposed to isotopes of hydrogen and anomalous results obtained. These are claimed to be a replication of another experiment conducted by Arata and Zhang. Erroneous basic assumptions are pointed out herein that alter the derived conclusions significantly. The final conclusion is that the reported results are likely normal chemistry combined with noise. Thus the claim to have proven that cold fusion is occurring in these systems is both premature and unlikely.

Shanahan, K.

2009-10-01T23:59:59.000Z

219

EVIDENCE FOR MAGNESIUM ISOTOPE HETEROGENEITY IN THE SOLAR PROTOPLANETARY DISK  

SciTech Connect (OSTI)

With a half-life of 0.73 Myr, the {sup 26}Al-to-{sup 26}Mg decay system is the most widely used short-lived chronometer for understanding the formation and earliest evolution of the solar protoplanetary disk. However, the validity of {sup 26}Al-{sup 26}Mg ages of meteorites and their components relies on the critical assumption that the canonical {sup 26}Al/{sup 27}Al ratio of {approx}5 x 10{sup -5} recorded by the oldest dated solids, calcium-aluminium-rich inclusions (CAIs), represents the initial abundance of {sup 26}Al for the solar system as a whole. Here, we report high-precision Mg-isotope measurements of inner solar system solids, asteroids, and planets demonstrating the existence of widespread heterogeneity in the mass-independent {sup 26}Mg composition ({mu}{sup 26}Mg*) of bulk solar system reservoirs with solar or near-solar Al/Mg ratios. This variability may represent heterogeneity in the initial abundance of {sup 26}Al across the solar protoplanetary disk at the time of CAI formation and/or Mg-isotope heterogeneity. By comparing the U-Pb and {sup 26}Al-{sup 26}Mg ages of pristine solar system materials, we infer that the bulk of the {mu}{sup 26}Mg* variability reflects heterogeneity in the initial abundance of {sup 26}Al across the solar protoplanetary disk. We conclude that the canonical value of {approx}5 x 10{sup -5} represents the average initial abundance of {sup 26}Al only in the CAI-forming region, and that large-scale heterogeneity-perhaps up to 80% of the canonical value-may have existed throughout the inner solar system. If correct, our interpretation of the Mg-isotope composition of inner solar system objects precludes the use of the {sup 26}Al-{sup 26}Mg system as an accurate early solar system chronometer.

Larsen, Kirsten K.; Trinquier, Anne; Paton, Chad; Schiller, Martin; Wielandt, Daniel; Connelly, James N.; Nordlund, Ake; Krot, Alexander N.; Bizzarro, Martin [Centre for Star and Planet Formation, Natural History Museum of Denmark, University of Copenhagen, Copenhagen DK-1350 (Denmark); Ivanova, Marina A. [Vernadsky Institute of Geochemistry and Analytical Chemistry, Moscow 119991 (Russian Federation)

2011-07-10T23:59:59.000Z

220

Nonequilibrium clumped isotope signals in microbial methane  

E-Print Network [OSTI]

Methane is a key component in the global carbon cycle with a wide range of anthropogenic and natural sources. Although isotopic compositions of methane have traditionally aided source identification, the abundance of its ...

Wang, David T.

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

A SUPERCONDUCTING-SOLENOID ISOTOPE SPECTROMETER  

E-Print Network [OSTI]

A SUPERCONDUCTING-SOLENOID ISOTOPE SPECTROMETER FOR PRODUCTION OF NEUTRON-RICH NUCLEI ( 136 Xe Superconducting Cyclotron Laboratory's weekly \\Green Sheet," 30 July 1999 #12; c Thomas W. O'Donnell 2000 All

O'Donnell, Tom

222

Direct mass measurements beyond the proton drip-line  

E-Print Network [OSTI]

First on-line mass measurements were performed at the SHIPTRAP Penning trap mass spectrometer. The masses of 18 neutron-deficient isotopes in the terbium-to-thulium region produced in fusion-evaporation reactions were determined with relative uncertainties of about $7\\cdot 10^{-8}$, nine of them for the first time. Four nuclides ($^{144, 145}$Ho and $^{147, 148}$Tm) were found to be proton-unbound. The implication of the results on the location of the proton drip-line is discussed by analyzing the one-proton separation energies.

C. Rauth; D. Ackermann; K. Blaum; M. Block; A. Chaudhuri; S. Eliseev; R. Ferrer; D. Habs; F. Herfurth; F. P. Hessberger; S. Hofmann; H. -J. Kluge; G. Maero; A. Martin; G. Marx; M. Mukherjee; J. B. Neumayr; W. R. Plass; W. Quint; S. Rahaman; D. Rodriguez; C. Scheidenberger; L. Schweikhard; P. G. Thirolf; G. Vorobjev; C. Weber; Z. Di

2007-01-22T23:59:59.000Z

223

Symmetry Energy and the Isoscaling in Reactions on Enriched Tin Isotopes  

E-Print Network [OSTI]

The coefficients of symmetry energy term for fragments with Z=4,11,12 measured in multifragmentation reactions initiated by proton and deuteron with energy of 3.65A GeV on enriched tin isotopes 112,118,120,124Sn are determined. The dependence of isoscaling parameter on the excitation energy, the temperature of fragmenting systems and the density ratio for heavy mass products are analised.

A. S. Danagulyan; A. R. Balabekyan; G. H. Hovhannisyan

2009-02-17T23:59:59.000Z

224

System size effects and N/Z dependence of balance energy for different isotopic series  

E-Print Network [OSTI]

We study the N/Z dependence of energy of vanishing flow or balance energy for different isotopic series of various system masses like Ca+Ca, Ni+Ni, Zr+Zr, Sn+Sn and Xe+Xe. We find that balance energy decreases with N/Z of the system and follows a linear behaviour. The slope of N/Z dependence is steeper for lighter systems like Ca+Ca and less for heavier ones like Xe+Xe.

Aman D. Sood; Sakshi Gautam

2011-12-13T23:59:59.000Z

225

The Oxygen core inside the Magnesium isotopes  

E-Print Network [OSTI]

We have studied the ground state bulk properties of magnesium isotopes using axially symmetric relativistic mean field formalism. The BCS pairing approach is employed to take care of the pairing correlation for the open shell nuclei. The contour plot of the nucleons distribution are analyzed at various parts of the nucleus, where clusters are located. The presence of an $^{16}$O core along bubble like $\\alpha$-particle(s) and few {\\it nucleons} are found in the Mg isotopes.

Bhuyan, M

2013-01-01T23:59:59.000Z

226

Mechanistic studies using kinetic isotope effects  

E-Print Network [OSTI]

MECHANISTIC STUDIES USING KINETIC ISOTOPE EFFECTS A Thesis by BRIAN E. SCHULMFIER Submitted to the Office of Graduate Studies of Texas ARM University in partial fulfillment of the requtrements for the degree of MASTER OF SCIENCE December... 1999 Major Subject: Chemistry MECHANISTIC STUDIES USING KINETIC ISOTOPE EFFECTS A Thesis by BRIAN E. SCHULMEIER Submitted to Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Approved...

Schulmeier, Brian E.

2012-06-07T23:59:59.000Z

227

Natural thorium isotopes in marine sediment core off Labuan port  

SciTech Connect (OSTI)

Sediment core was collected from Labuan port and analyzed to determine the radioactivity of thorium (Th) isotopes. The objectives of this study are to determine the possible sources of Th isotopes at Labuan port and estimates the sedimentation rate based on {sup 228}Th/{sup 232}Th model. The results suggest the {sup 230}Th and {sup 232}Th might be originated from terrestrial sedimentary rock while {sup 228}Th originated by authigenic origin. High ratio value of {sup 230}Th/{sup 232}Th detected at the top surface sediment indicates the increasing of {sup 230}Th at the recent years which might be contributed from the anthropogenic sources. The sedimentation rate of core sediment from Labuan Port was successfully estimated by using {sup 228}Th/{sup 232}Th model. The result show high sedimentation rate with 4.67 cm/year indicates rapid deposition occurred at this study area due to the high physical activity at the Labuan port. By assume the constant sedimentation rate at this area; we estimated the age of 142 cm core sediment obtained from Labuan port is 32 years started from 1981 to 2012. This chronology will be used in forthcoming research to investigate the historical profile of anthropogenic activities affecting the Labuan port.

Hafidz, B. Y.; Asnor, A. S.; Terence, R. C.; Mohamed, C. A. R. [School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia 43600, Bangi, Selangor (Malaysia)

2014-02-12T23:59:59.000Z

228

Couplings between dipole and quadrupole vibrations in tin isotopes  

E-Print Network [OSTI]

We study the couplings between collective vibrations such as the isovector giant dipole and isoscalar giant quadrupole resonances in tin isotopes in the framework of the time-dependent Hartree-Fock theory with a Skyrme energy density functional. These couplings are a source of anharmonicity in the multiphonon spectrum. In particular, the residual interaction is known to couple the isovector giant dipole resonance with the isoscalar giant quadrupole resonance built on top of it, inducing a nonlinear evolution of the quadrupole moment after a dipole boost. This coupling also affects the dipole motion in a nucleus with a static or dynamical deformation induced by a quadrupole constraint or boost respectively. Three methods associated with these different manifestations of the coupling are proposed to extract the corresponding matrix elements of the residual interaction. Numerical applications of the different methods to 132Sn are in good agreement with each other. Finally, several tin isotopes are considered to investigate the role of isospin and mass number on this coupling. A simple 1/A dependence of the residual matrix elements is found with no noticeable contribution from the isospin. This result is interpreted within the Goldhaber-Teller model.

Cédric Simenel; Philippe Chomaz

2009-12-11T23:59:59.000Z

229

Strontium and carbon isotope stratigraphy of the Llandovery (Early Silurian): Implications for tectonics and weathering  

E-Print Network [OSTI]

Strontium and carbon isotope stratigraphy of the Llandovery (Early Silurian): Implications online 2 June 2010 Keywords: Silurian Strontium isotopes Carbon isotopes Weathering K-bentonites A high

Saltzman, Matthew R.

230

Oxygen isotope fractionation in the vacuum ultraviolet photodissociation of carbon monoxide: Wavelength, pressure and temperature dependency.  

E-Print Network [OSTI]

Oxygen isotope fractionation in the vacuum ultravioletmeasurement of the associated oxygen isotopic composition ofwavelength dependency of the oxygen isotopic composition in

Chakraborty, Subrata

2013-01-01T23:59:59.000Z

231

Method for correcting for isotope burn-in effects in fission neutron dosimeters  

DOE Patents [OSTI]

A method is described for correcting for effect of isotope burn-in in fission neutron dosimeters. Two quantities are measured in order to quantify the "burn-in" contribution, namely P.sub.Z',A', the amount of (Z', A') isotope that is burned-in, and F.sub.Z', A', the fissions per unit volume produced in the (Z', A') isotope. To measure P.sub.Z', A', two solid state track recorder fission deposits are prepared from the very same material that comprises the fission neutron dosimeter, and the mass and mass density are measured. One of these deposits is exposed along with the fission neutron dosimeter, whereas the second deposit is subsequently used for observation of background. P.sub.Z', A' is then determined by conducting a second irradiation, wherein both the irradiated and unirradiated fission deposits are used in solid state track recorder dosimeters for observation of the absolute number of fissions per unit volume. The difference between the latter determines P.sub.Z', A' since the thermal neutron cross section is known. F.sub.Z', A' is obtained by using a fission neutron dosimeter for this specific isotope, which is exposed along with the original threshold fission neutron dosimeter to experience the same neutron flux-time history at the same location. In order to determine the fissions per unit volume produced in the isotope (Z', A') as it ingrows during the irradiation, B.sub.Z', A', from these observations, the neutron field must generally be either time independent or a separable function of time t and neutron energy E.

Gold, Raymond (Richland, WA); McElroy, William N. (Richland, WA)

1988-01-01T23:59:59.000Z

232

- and -delayed neutron- decay of neutron-rich copper isotopes  

SciTech Connect (OSTI)

The {beta}-decay properties of neutron-rich Cu isotopes produced in proton-induced fission of {sup 238}U were studied at the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory. The data were collected using high-resolution online mass separation, reacceleration, and digital {beta}-{gamma} spectroscopy methods. An improved decay scheme of N = 49 {sup 78}Cu and the first observation of N = 50 {sup 79}Cu {beta}-delayed neutron decay followed by a gamma transition are reported. Spin and parity (5{sup -}) are deduced for {sup 78gs}Cu. The {beta}-delayed neutron branching ratios (P{sub {beta}n}) for the {sup 77}Cu and {sup 79}Cu precursors are analyzed with the help of nuclear structure models.

Korgul, A. [University of Warsaw; Rykaczewski, Krzysztof Piotr [ORNL; Winger, J. A. [Oak Ridge Associated Universities (ORAU); Ilyushkin, S. [Mississippi State University (MSU); Gross, Carl J [ORNL; Batchelder, J. C. [Oak Ridge Associated Universities (ORAU); Bingham, C. R. [University of Tennessee, Knoxville (UTK); Borzov, Ivan N [ORNL; Goodin, C. [Vanderbilt University; Grzywacz, Robert Kazimierz [ORNL; Hamilton, Joseph H [ORNL; Krolas, W. [Joint Institute for Heavy Ion Research, Oak Ridge; Liddick, S. N. [Oak Ridge Associated Universities (ORAU); Mazzocchi, C. [University of Warsaw; Nelson, C. [Vanderbilt University; Nowacki, F. [Institut Pluridisciplinaire Hubert Curien, Strasbourg, France; Padgett, Stephen [University of Tennessee, Knoxville (UTK); Piechaczek, A. [Louisiana State University; Rajabali, M. M. [University of Tennessee, Knoxville (UTK); Shapira, Dan [ORNL; Sieja, K. [Technische Universitat Darmstadt, Germany; Zganjar, E. F. [Louisiana State University

2012-01-01T23:59:59.000Z

233

Exotic fission properties of highly neutron-rich Uranium isotopes  

E-Print Network [OSTI]

The series of Uranium isotopes with $N=154 \\sim 172$ around the magic number N=162/164 are identified to be thermally fissile. The thermal neutron fission of a typical representative $^{249}$U of this region amenable to synthesis in the radioactive ion beam facilities is considered here. Semiempirical study of fission barrier height and width shows this nucleus to be infinitely stable against spontaneous fission due to increase in barrier width arising out of excess neutrons. Calculation of probability of fragment mass yields and microscopic study in relativistic mean field theory, show this nucleus to undergo a new mode of thermal fission decay termed {\\it multifragmentation fission} where a number of prompt scission neutrons are simultaneously released along with the two heavy fission fragments.

L. Satpathy; S. K. Patra; R. K. Choudhury

2007-03-05T23:59:59.000Z

234

UW Cosmogenic Isotopes Al-Be 1 EXTRACTION OF Al & Be FROM QUARTZ FOR ISOTOPIC ANALYSIS  

E-Print Network [OSTI]

UW Cosmogenic Isotopes Al-Be 1 EXTRACTION OF Al & Be FROM QUARTZ FOR ISOTOPIC ANALYSIS Summary This method is used to separate Al and Be for AMS analysis from pure quartz samples. After adding Be carrier, quartz is dissolved in HF. The solution is sub-sampled for determination of total Al content, then dried

Stone, John

235

Influence of liquid structure on diffusive isotope separation in molten silicates and aqueous solutions  

SciTech Connect (OSTI)

Molecular diffusion in natural volcanic liquids discriminates between isotopes of major ions (e.g., Fe, Mg, Ca, and Li). Although isotope separation by diffusion is expected on theoretical grounds, the dependence on mass is highly variable for different elements and in different media. Silicate liquid diffusion experiments using simple liquid compositions were carried out to further probe the compositional dependence of diffusive isotopic discrimination and its relationship to liquid structure. Two diffusion couples consisting of the mineral constituents anorthite (CaAl{sub 2}Si{sub 2}O{sub 8}; denoted AN), albite (NaAlSi{sub 3}O{sub 8}; denoted AB), and diopside (CaMgSi{sub 2}O{sub 6}; denoted DI) were held at 1450°C for 2 h and then quenched to ambient pressure and temperature. Major-element as well as Ca and Mg isotope profiles were measured on the recovered quenched glasses. In both experiments, Ca diffuses rapidly with respect to Si. In the AB–AN experiment, D{sub Ca}/D{sub Si} ~ 20 and the efficiency of isotope separation for Ca is much greater than in natural liquid experiments where D{sub Ca}/D{sub Si} ~ 1. In the AB–DI experiment, D{sub Ca}/D{sub Si} ~ 6 and the efficiency of isotope separation is between that of the natural liquid experiments and the AB–AN experiment. In the AB–DI experiment, D{sub Mg}/D{sub Si} ~ 1 and the efficiency of isotope separation for Mg is smaller than it is for Ca yet similar to that observed for Mg in natural liquids. The results from the experiments reported here, in combination with results from natural volcanic liquids, show clearly that the efficiency of diffusive separation of Ca isotopes is systematically related to the solvent-normalized diffusivity—the ratio of the diffusivity of the cation (D{sub Ca}) to the diffusivity of silicon (D{sub Si}). The results on Ca isotopes are consistent with available data on Fe, Li, and Mg isotopes in silicate liquids, when considered in terms of the parameter D{sub cation}/D{sub Si}. Cations diffusing in aqueous solutions display a similar relationship between isotopic separation efficiency and D{sub cation} =D{sub H 2 O} , although the efficiencies are smaller than in silicate liquids. Our empirical relationship provides a tool for predicting the magnitude of diffusive isotopic effects in many geologic environments and a basis for a more comprehensive theory of isotope separation in liquid solutions. We present a conceptual model for the relationship between diffusivity and liquid structure that is consistent with available data.

Watkins, J.M.; DePaolo, D.J.; Ryerson, F.J.; Peterson, B.

2011-03-01T23:59:59.000Z

236

Clarification of C-S relationships of marine black shales using stable isotopic composition of reduced sulfur  

SciTech Connect (OSTI)

Carbon-sulfur relationships are compared for the Miocene Monterey Formation (Santa Maria Basin, California) and the Upper Devonian New Albany Shale (Illinois Basin, Indiana). In both formations, C-S concentrations covary for samples with the lower to more intermediate organic carbon concentrations and become invariant at higher organic carbon concentrations. While the similarity of these relationships in Monterey and New Albany suggest sulfur diagenesis occurred in similar depositional environments, sulfur isotopic data clearly indicate differences in the depositional environments. In the Monterey, the most organic-rich laminated shales are characterized by isotopic enrichment of reduced S and low S ratios and indicate that sulfate reduction occurred under sulfate-limited conditions within the sediments. In the New Albany, organic-rich laminated shales exhibit isotopic depletion of reduced S coupled with low S[sub reduced]/C[sub org] and suggest sulfur diagenesis occurred under euxinic conditions. These data show that in the absence of sulfur isotopic data, misleading conclusions concerning depositional environments can be made when using C-S plots and the traditional interpretations that are associated with these types of plots.

Zaback, D.A.; Pratt, L.M. (Indiana Univ., Bloomington, IN (United States). Dept. of Geological Sciences)

1992-01-01T23:59:59.000Z

237

Proton elastic scattering from tin isotopes at 295 MeV and systematic change of neutron density distributions  

E-Print Network [OSTI]

Cross sections and analyzing powers for proton elastic scattering from $^{116,118,120,122,124}$Sn at 295 MeV have been measured for a momentum transfer of up to about 3.5 fm$^{-1}$ to deduce systematic changes of the neutron density distribution. We tuned the relativistic Love-Franey interaction to explain the proton elastic scattering of a nucleus whose density distribution is well known. Then, we applied this interaction to deduce the neutron density distributions of tin isotopes. The result of our analysis shows the clear systematic behavior of a gradual increase in the neutron skin thickness of tin isotopes with mass number.

S. Terashima; H. Sakaguchi; H. Takeda; T. Ishikawa; M. Itoh; T. Kawabata; T. Murakami; M. Uchida; Y. Yasuda; M. Yosoi; J. Zenihiro; H. P. Yoshida; T. Noro; T. Ishida; S. Asaji; T. Yonemura

2008-02-02T23:59:59.000Z

238

Nuclear Moments and Differences in Mean Square Charge Radii of Short-Lived Neon Isotopes by Collinear Laser Spectroscopy  

E-Print Network [OSTI]

The nuclear moments and charge radii of short-lived neon isotopes were measured by the use of collinear laser spectroscopy at the on-line mass separator ISOLDE at CERN. After a general introduction the semiclassical theory of atomic spectra is given and the relevant properties are calculated for neon. The atomic physics section is followed by a description of the experimental setup of the collinear laser spectroscopy experiment at ISOLDE. From the mass separator an isotopically clean ion beam with a kinetic energy of 60 keV is delivered to the experiments. In collinear laser spectroscopy the incoming ion beam from the mass separator is superimposed to a single frequency cw laser beam. The frequency of the atomic transition $\

Geithner, R W

2002-01-01T23:59:59.000Z

239

Laser Isotope Separation Employing Condensation Repression  

SciTech Connect (OSTI)

Molecular laser isotope separation (MLIS) techniques using condensation repression (CR) harvesting are reviewed and compared with atomic vapor laser isotope separation (AVLIS), gaseous diffusion (DIF), ultracentrifuges (UCF), and electromagnetic separations (EMS). Two different CR-MLIS or CRISLA (Condensation Repression Isotope Separation by Laser Activation) approaches have been under investigation at the University of Missouri (MU), one involving supersonic super-cooled free jets and dimer formation, and the other subsonic cold-wall condensation. Both employ mixtures of an isotopomer (e.g. {sup i}QF{sub 6}) and a carrier gas, operated at low temperatures and pressures. Present theories of VT relaxation, dimerization, and condensation are found to be unsatisfactory to explain/predict experimental CRISLA results. They were replaced by fundamentally new models that allow ab-initio calculation of isotope enrichments and predictions of condensation parameters for laser-excited and non-excited vapors which are in good agreement with experiment. Because of supersonic speeds, throughputs for free-jet CRISLA are a thousand times higher than cold-wall CRISLA schemes, and thus preferred for large-quantity Uranium enrichments. For small-quantity separations of (radioactive) medical isotopes, the simpler coldwall CRISLA method may be adequate.

Eerkens, Jeff W.; Miller, William H.

2004-09-15T23:59:59.000Z

240

Searching for isovector signatures in the neutron-rich oxygen and calcium isotopes  

E-Print Network [OSTI]

We search for potential isovector signatures in the neutron-rich oxygen and calcium isotopes within the framework of a relativistic mean-field theory with an exact treatment of pairing correlations. To probe the isovector sector we calibrate a few relativistic density functionals using the same isoscalar constraints but with one differing isovector assumption. It is found that under certain conditions, the isotopic chain in oxygen can be made to terminate at the experimentally observed ${}^{24}$O isotope and in the case of the calcium isotopes at ${}^{60}$Ca. To produce such behavior, the resulting symmetry energy must be soft, with predicted values for the symmetry energy and its slope at saturation density being $J\\!=\\!(30.92\\pm0.47)$ MeV and $L\\!=\\!(51.0\\pm1.5)$ MeV, respectively. As a consequence, the neutron-skin thickness of ${}^{208}$Pb is rather small: $R_{\\rm skin}^{208}\\!=\\!(0.161\\pm0.011)$ fm. This same model - labelled "FSUGarnet" - predicts $R_{1.4}\\!=\\!(13.1\\pm0.1)$ km for the radius of a "canonical" 1.4$M_{\\odot}$ neutron star, yet is also able to support a two-solar-mass neutron star.

Wei-Chia Chen; J. Piekarewicz

2015-03-10T23:59:59.000Z

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Searching for isovector signatures in the neutron-rich oxygen and calcium isotopes  

E-Print Network [OSTI]

We search for potential isovector signatures in the neutron-rich oxygen and calcium isotopes within the framework of a relativistic mean-field theory with an exact treatment of pairing correlations. To probe the isovector sector we calibrate a few relativistic density functionals using the same isoscalar constraints but with one differing isovector assumption. It is found that under certain conditions, the isotopic chain in oxygen can be made to terminate at the experimentally observed ${}^{24}$O isotope. In the case of the calcium isotopes, the drip line is predicted to be reached beyond ${}^{60}$Ca. To produce such behavior, the resulting symmetry energy must be soft, with predicted values for the symmetry energy and its slope at saturation density being $J\\!=\\!(30.92\\pm0.47)$ MeV and $L\\!=\\!(51.0\\pm1.5)$ MeV, respectively. As a consequence, the neutron-skin thickness of ${}^{208}$Pb is rather small: $R_{\\rm skin}^{208}\\!=\\!(0.161\\pm0.011)$ fm. This same model - labelled "FSUGarnet" - predicts $R_{1.4}\\!=\\!(13.1\\pm0.1)$ km for the radius of a "canonical" 1.4$M_{\\odot}$ neutron star, yet is also able to support a two-solar-mass neutron star.

Wei-Chia Chen; J. Piekarewicz

2014-12-25T23:59:59.000Z

242

O Isotopic Composition of CaCO3 Measured by Continuous Flow Isotope Ratio Mass Spectrometry: Statistical Evaluation and  

E-Print Network [OSTI]

of carbon-13 and oxygen-18 to determine the ratios of the rare (usually the heavy) to the more common water, and two gases, water vapor, and carbon dioxide. First, both gases are frozen in liquid nitrogen. The frozen gases then are exposed to a dry ice slush, and the carbon dioxide sublimates while the water stays

243

First Results from the CARIBU Facility: Mass Measurements on the r-Process Path  

E-Print Network [OSTI]

The Canadian Penning Trap mass spectrometer has made mass measurements of 33 neutron-rich nuclides provided by the new Californium Rare Isotope Breeder Upgrade (CARIBU) facility at Argonne National Laboratory. The studied region includes the 132Sn double shell closure and ranges in Z from In to Cs, with Sn isotopes measured out to A = 135, and the typical measurement precision is at the 100 ppb level or better. The region encompasses a possible major waiting point of the astrophysical r process, and the impact of the masses on the r process is shown through a series of simulations. These first-ever simulations with direct mass information on this waiting point show significant increases in waiting time at Sn and Sb in comparison with commonly used mass models, demonstrating the inadequacy of existing models for accurate r-process calculations.

J. Van Schelt; D. Lascar; G. Savard; J. A. Clark; P. F. Bertone; S. Caldwell; A. Chaudhuri; 1 A. F. Levand; G. Li; G. E. Morgan; R. Orford; R. E. Segel; K. S. Sharma; M. G. Sternberg

2013-07-01T23:59:59.000Z

244

Ultra High Mass Range Mass Spectrometer System  

DOE Patents [OSTI]

Applicant's present invention comprises mass spectrometer systems that operate in a mass range from 1 to 10.sup.16 DA. The mass spectrometer system comprising an inlet system comprising an aerodynamic lens system, a reverse jet being a gas flux generated in an annulus moving in a reverse direction and a multipole ion guide; a digital ion trap; and a thermal vaporization/ionization detector system. Applicant's present invention further comprises a quadrupole mass spectrometer system comprising an inlet system having a quadrupole mass filter and a thermal vaporization/ionization detector system. Applicant's present invention further comprises an inlet system for use with a mass spectrometer system, a method for slowing energetic particles using an inlet system. Applicant's present invention also comprises a detector device and a method for detecting high mass charged particles.

Reilly, Peter T. A. [Knoxville, TN

2005-12-06T23:59:59.000Z

245

Opportunistic Mass Measurements at the Holifield Radioactive Ion Beam Facility  

SciTech Connect (OSTI)

A technique for measuring mass differences has been developed at the Holifield Radioactive Ion Beam Facility (HRIBF) that requires no specialized equipment. Mass differences are measured as position differences between known and unknown-mass isobars, dispersed at the image of the energy-analyzing magnet following the 25MV tandem post-accelerator, and identified by an energy-loss measurement. The technique has been demonstrated on neutron-rich 77 79Cu and 83 86Ge isotopes produced using the isotope separator online (ISOL) method with the 238U(p,fission) reaction, where a mass accuracy of 500 keV was achieved. These nuclides are well suited to the measurement technique, as they readily migrate out of the production target and to the ion source and comprise the most neutron-rich elements of the isobarically mixed beam. Because modest precision mass values can be obtained with only a few tens of counts of the nuclide of interest among orders of magnitude more of the isobaric neighbors closer to stability, the sensitivity of this technique makes it appropriate for initial mass measurements far from stability.

Hausladen, Paul [ORNL; Beene, James R [ORNL; Galindo-Uribarri, Alfredo {nmn} [ORNL; Larochelle, Y [University of Tennessee, Knoxville (UTK); Liang, J Felix [ORNL; Mueller, Paul Edward [ORNL; Shapira, Dan [ORNL; Stracener, Daniel W [ORNL; Thomas, J. S. [Rutgers University; Varner Jr, Robert L [ORNL; Wollnik, Hermann [ORNL

2006-01-01T23:59:59.000Z

246

Atomic line emission analyzer for hydrogen isotopes  

DOE Patents [OSTI]

Apparatus for isotopic analysis of hydrogen comprises a low pressure chamber into which a sample of hydrogen is introduced and then exposed to an electrical discharge to excite the electrons of the hydrogen atoms to higher energy states and thereby cause the emission of light on the return to lower energy states, a Fresnel prism made at least in part of a material anomalously dispersive to the wavelengths of interest for dispersing the emitted light, and a photodiode array for receiving the dispersed light. The light emitted by the sample is filtered to pass only the desired wavelengths, such as one of the lines of the Balmer series for hydrogen, the wavelengths of which differ slightly from one isotope to another. The output of the photodiode array is processed to determine the relative amounts of each isotope present in the sample. Additionally, the sample itself may be recovered using a metal hydride.

Kronberg, James W. (108 Independent Blvd., Aiken, SC 29801)

1993-01-01T23:59:59.000Z

247

Atomic line emission analyzer for hydrogen isotopes  

DOE Patents [OSTI]

Apparatus for isotopic analysis of hydrogen comprises a low pressure chamber into which a sample of hydrogen is introduced and then exposed to an electrical discharge to excite the electrons of the hydrogen atoms to higher energy states and thereby cause the emission of light on the return to lower energy states, a Fresnel prism made at least in part of a material anomalously dispersive to the wavelengths of interest for dispersing the emitted light, and a photodiode array for receiving the dispersed light. The light emitted by the sample is filtered to pass only the desired wavelengths, such as one of the lines of the Balmer series for hydrogen, the wavelengths of which differ slightly from one isotope to another. The output of the photodiode array is processed to determine the relative amounts of each isotope present in the sample. Additionally, the sample itself may be recovered using, a metal hydride.

Kronberg, J.W.

1991-05-08T23:59:59.000Z

248

Apparatus for separating and recovering hydrogen isotopes  

DOE Patents [OSTI]

An apparatus for recovering hydrogen and separating its isotopes. The apparatus includes a housing bearing at least a fluid inlet and a fluid outlet. A baffle is disposed within the housing, attached thereto by a bracket. A hollow conduit is coiled about the baffle, in spaced relation to the baffle and the housing. The coiled conduit is at least partially filled with a hydride. The hydride can be heated to a high temperature and cooled to a low temperature quickly by circulating a heat transfer fluid in the housing. The spacing between the baffle and the housing maximizes the heat exchange rate between the fluid in the housing and the hydride in the conduit. The apparatus can be used to recover hydrogen isotopes (protium, deuterium and tritium) from gaseous mixtures, or to separate hydrogen isotopes from each other.

Heung, Leung K. (Aiken, SC)

1994-01-01T23:59:59.000Z

249

Atomic line emission analyzer for hydrogen isotopes  

DOE Patents [OSTI]

Apparatus for isotopic analysis of hydrogen comprises a low pressure chamber into which a sample of hydrogen is introduced and then exposed to an electrical discharge to excite the electrons of the hydrogen atoms to higher energy states and thereby cause the emission of light on the return to lower energy states, a Fresnel prism made at least in part of a material anomalously dispersive to the wavelengths of interest for dispersing the emitted light, and a photodiode array for receiving the dispersed light. The light emitted by the sample is filtered to pass only the desired wavelengths, such as one of the lines of the Balmer series for hydrogen, the wavelengths of which differ slightly from one isotope to another. The output of the photodiode array is processed to determine the relative amounts of each isotope present in the sample. Additionally, the sample itself may be recovered using a metal hydride.

Kronberg, J.W.

1993-03-30T23:59:59.000Z

250

Laboratory and numerical investigation of transport processes occurring above and within a saltwater wedge  

E-Print Network [OSTI]

Laboratory and numerical investigation of transport processes occurring above and within recent studies have investigated saltwater transport in coastal aquifers and the associated flow wedge itself or on studying contaminant transport processes occurring above the wedge. As per our

Clement, Prabhakar

251

Method for production of an isotopically enriched compound  

DOE Patents [OSTI]

A method is presented for producing and isolating an isotopically enriched compound of a desired isotope from a parent radionuclide. The method includes forming, or placing, a precipitate containing a parent radionuclide of the desired daughter isotope in a first reaction zone and allowing sufficient time for the parent to decay into the desired gaseous daughter radioisotope. The method further contemplates collecting the desired daughter isotope as a solid in a second reaction zone through the application of temperatures below the freezing point of the desired isotope to a second reaction zone that is connected to the first reaction zone. Specifically, a method is presented for producing isotopically enriched compounds of xenon, including the radioactive isotope Xe-131m and the stable isotope Xe-131.

Watrous, Matthew G.

2012-12-11T23:59:59.000Z

252

Hydrogen isotope fractionation during lipid biosynthesis by Haloarcula marismortui  

E-Print Network [OSTI]

Hydrogen isotope fractionation during lipid biosynthesis by Haloarcula marismortui Sitindra S studied the controls on the fractionation of hydrogen isotopes during lipid biosynthesis by Haloarcula marismortui, a halophilic archaea, in pure culture experiments by varying organic substrate, the hydrogen

253

Isotopic abundance in atom trap trace analysis  

DOE Patents [OSTI]

A method and system for detecting ratios and amounts of isotopes of noble gases. The method and system is constructed to be able to measure noble gas isotopes in water and ice, which helps reveal the geological age of the samples and understand their movements. The method and system uses a combination of a cooled discharge source, a beam collimator, a beam slower and magneto-optic trap with a laser to apply resonance frequency energy to the noble gas to be quenched and detected.

Lu, Zheng-Tian; Hu, Shiu-Ming; Jiang, Wei; Mueller, Peter

2014-03-18T23:59:59.000Z

254

Isotope Research Materials Laboratory | ornl.gov  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFunInfrared LandResponsesIon/SurfacePump-Testing Sign InIsotope ProgramIsotope

255

Isotopic Analysis- Rock At Valles Caldera - Sulphur Springs Geothermal...  

Open Energy Info (EERE)

navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis- Rock At Valles Caldera - Sulphur Springs Geothermal Area (Phillips, 2004)...

256

Isotopic Analysis At Lassen Volcanic National Park Area (Janik...  

Open Energy Info (EERE)

navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis At Lassen Volcanic National Park Area (Janik & Mclaren, 2010) Exploration Activity...

257

Isotopic Analysis- Rock At Valles Caldera - Sulphur Springs Geothermal...  

Open Energy Info (EERE)

navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis- Rock At Valles Caldera - Sulphur Springs Geothermal Area (Ito & Tanaka, 1995)...

258

Isotopic Analysis- Rock At Valles Caldera - Sulphur Springs Area...  

Open Energy Info (EERE)

navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis- Rock At Valles Caldera - Sulphur Springs Area (Ito & Tanaka, 1995) Exploration...

259

Isotopic Analysis At Valles Caldera - Redondo Geothermal Area...  

Open Energy Info (EERE)

navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis At Valles Caldera - Redondo Geothermal Area (Phillips, 2004) Exploration Activity...

260

Isotopic Analysis- Gas At Dixie Valley Geothermal Area (Kennedy...  

Open Energy Info (EERE)

search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis- Gas At Dixie Valley Geothermal Area (Kennedy & Soest, 2006) Exploration Activity Details...

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Discovery of dysprosium, holmium, erbium, thulium, and ytterbium isotopes  

SciTech Connect (OSTI)

Currently, thirty-one dysprosium, thirty-two holmium, thirty-two erbium, thirty-three thulium, and thirty-one ytterbium isotopes have been observed and the discovery of these isotopes is described here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

Fry, C.; Thoennessen, M., E-mail: thoennessen@nscl.msu.edu

2013-09-15T23:59:59.000Z

262

Discovery of palladium, antimony, tellurium, iodine, and xenon isotopes  

SciTech Connect (OSTI)

Currently, thirty-eight palladium, thirty-eight antimony, thirty-nine tellurium, thirty-eight iodine, and forty xenon isotopes have been observed and the discovery of these isotopes is described here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

Kathawa, J.; Fry, C.; Thoennessen, M., E-mail: thoennessen@nscl.msu.edu

2013-01-15T23:59:59.000Z

263

Discovery of the astatine, radon, francium, and radium isotopes  

SciTech Connect (OSTI)

Thirty-nine astatine, thirty-nine radon, thirty-five francium, and thirty-four radium isotopes have so far been observed; the discovery of these isotopes is described. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

Fry, C.; Thoennessen, M., E-mail: thoennessen@nscl.msu.edu

2013-09-15T23:59:59.000Z

264

Discovery of samarium, europium, gadolinium, and terbium isotopes  

SciTech Connect (OSTI)

Currently, thirty-four samarium, thirty-four europium, thirty-one gadolinium, and thirty-one terbium isotopes have been observed and the discovery of these isotopes is described here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

May, E.; Thoennessen, M., E-mail: thoennessen@nscl.msu.edu

2013-01-15T23:59:59.000Z

265

Discovery of Rubidium, Strontium, Molybdenum, and Rhodium Isotopes  

E-Print Network [OSTI]

Currently, thirty-one rubidium, thirty-five strontium, thirty-five molybdenum and thirty-eight rhodium isotopes have been observed and the discovery of these isotopes is discussed here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

Parker, A M

2011-01-01T23:59:59.000Z

266

Discovery of rubidium, strontium, molybdenum, and rhodium isotopes  

SciTech Connect (OSTI)

Currently, 31 rubidium, 35 strontium, 35 molybdenum, and 38 rhodium isotopes have been observed and the discovery of these isotopes is described here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

Parker, A.M.; Thoennessen, M., E-mail: thoennessen@nscl.msu.edu

2012-07-15T23:59:59.000Z

267

Discovery of Rubidium, Strontium, Molybdenum, and Rhodium Isotopes  

E-Print Network [OSTI]

Currently, thirty-one rubidium, thirty-five strontium, thirty-five molybdenum and thirty-eight rhodium isotopes have been observed and the discovery of these isotopes is discussed here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

A. M. Parker; M. Thoennessen

2011-02-11T23:59:59.000Z

268

Discovery of the actinium, thorium, protactinium, and uranium isotopes  

E-Print Network [OSTI]

Currently, 31 actinium, 31 thorium, 28 protactinium, and 23 uranium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

C. Fry; M. Thoennessen

2012-03-06T23:59:59.000Z

269

Discovery of Chromium, Manganese, Nickel, and Copper Isotopes  

E-Print Network [OSTI]

Twenty-seven chromium, twenty-five manganese, thirty-one nickel and twenty-six copper isotopes have so far been observed and the discovery of these isotopes is discussed. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

K. Garofali; R. Robinson; M. Thoennessen

2010-12-07T23:59:59.000Z

270

Discovery of Cesium, Lanthanum, Praseodymium and Promethium Isotopes  

E-Print Network [OSTI]

Currently, forty-one cesium, thirty-five lanthanum, thirty-two praseodymium, and thirty-one promethium, isotopes have been observed and the discovery of these isotopes is discussed here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

May, E

2011-01-01T23:59:59.000Z

271

Discovery of Cesium, Lanthanum, Praseodymium and Promethium Isotopes  

E-Print Network [OSTI]

Currently, forty-one cesium, thirty-five lanthanum, thirty-two praseodymium, and thirty-one promethium, isotopes have been observed and the discovery of these isotopes is discussed here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

E. May; M. Thoennessen

2011-09-08T23:59:59.000Z

272

Hydrogen isotope fractionation during lipid biosynthesis by Tetrahymena thermophila  

E-Print Network [OSTI]

Hydrogen isotope fractionation during lipid biosynthesis by Tetrahymena thermophila Sitindra S Accepted 7 September 2013 Available online 16 September 2013 a b s t r a c t Hydrogen isotope ratio values from recording the hydrogen isotope composition of ambient water, dD values of lipids also depend

273

Augmenting real data with synthetic data: an application in assessing radio-isotope identification algorithms  

SciTech Connect (OSTI)

The performance of Radio-Isotope Identification (RIID) algorithms using gamma spectroscopy is increasingly important. For example, sensors at locations that screen for illicit nuclear material rely on isotope identification to resolve innocent nuisance alarms arising from naturally occurring radioactive material. Recent data collections for RIID testing consist of repeat measurements for each of several scenarios to test RIID algorithms. Efficient allocation of measurement resources requires an appropriate number of repeats for each scenario. To help allocate measurement resources in such data collections for RIID algorithm testing, we consider using only a few real repeats per scenario. In order to reduce uncertainty in the estimated RIID algorithm performance for each scenario, the potential merit of augmenting these real repeats with realistic synthetic repeats is also considered. Our results suggest that for the scenarios and algorithms considered, approximately 10 real repeats augmented with simulated repeats will result in an estimate having comparable uncertainty to the estimate based on using 60 real repeats.

Burr, Tom L [Los Alamos National Laboratory; Hamada, Michael [Los Alamos National Laboratory; Graves, Todd [Los Alamos National Laboratory; Myers, Steve [Los Alamos National Laboratory

2008-01-01T23:59:59.000Z

274

Mass spectrometric immunoassay  

DOE Patents [OSTI]

Rapid mass spectrometric immunoassay methods for detecting and/or quantifying antibody and antigen analytes utilizing affinity capture to isolate the analytes and internal reference species (for quantification) followed by mass spectrometric analysis of the isolated analyte/internal reference species. Quantification is obtained by normalizing and calibrating obtained mass spectrum against the mass spectrum obtained for an antibody/antigen of known concentration.

Nelson, Randall W; Williams, Peter; Krone, Jennifer Reeve

2013-07-16T23:59:59.000Z

275

Mass spectrometric immunoassay  

DOE Patents [OSTI]

Rapid mass spectrometric immunoassay methods for detecting and/or quantifying antibody and antigen analytes utilizing affinity capture to isolate the analytes and internal reference species (for quantification) followed by mass spectrometric analysis of the isolated analyte/internal reference species. Quantification is obtained by normalizing and calibrating obtained mass spectrum against the mass spectrum obtained for an antibody/antigen of known concentration.

Nelson, Randall W (Phoenix, AZ); Williams, Peter (Phoenix, AZ); Krone, Jennifer Reeve (Granbury, TX)

2007-12-04T23:59:59.000Z

276

A review of stable water isotopeA review of stable water isotope modellingmodelling  

E-Print Network [OSTI]

fractionation · Kinetic fractionation 2. Modelling the stable water isotope cycle · Rayleigh distillation model Institution of Oceanography) Harald SODEMANN (Norwegian Institute for Air Research) Kristof 18Ovapour=-40 18Oocean=0 18Osnow=-3018Orain=-2 Equilibrium fractionationEquilibrium fractionation

Sturm, Christophe "Kristof"

277

The graphene phonon dispersion with C{sup 12} and C{sup 13} isotopes  

SciTech Connect (OSTI)

Using very uniform large scale chemical vapor deposition grown graphene transferred onto silicon, we were able to identify 15 distinct Raman lines associated with graphene monolayers. This was possible thanks to a combination of different carbon isotopes and different Raman laser energies and extensive averaging without increasing the laser power. This allowed us to obtain a detailed experimental phonon dispersion relation for many points in the Brillouin zone. We further identified a D+D' peak corresponding to a double phonon process involving both an inter- and intra-valley phonon. In order to both eliminate substrate effects and to probe large areas, we undertook to study Raman scattering for large scale chemical vapor deposition (CVD) grown graphene using two different isotopes (C12 and C13) so that we can effectively exclude and subtract the substrate contributions, since a heavier mass downshifts only the vibrational properties, while keeping all other properties the same.

Whiteway, Eric; Bernard, Simon; Yu, Victor; Hilke, Michael [Department of Physics, McGill University, Montréal H3A 2T8 (Canada); Austing, D. Guy [National Research Council of Canada, Ottawa, Ontario K1A 0R6 (Canada)

2013-12-04T23:59:59.000Z

278

Review of hydrogen isotope permeability through materials  

SciTech Connect (OSTI)

This report is the first part of a comprehensive summary of the literature on hydrogen isotope permeability through materials that do not readily form hydrides. While we mainly focus on pure metals with low permeabilities because of their importance to tritium containment, we also give data on higher-permeability materials such as iron, nickel, steels, and glasses.

Steward, S.A.

1983-08-15T23:59:59.000Z

279

Trace Element and Isotopic Fluxes/ Subducted Slab  

E-Print Network [OSTI]

3.20.7.2.1 Devolatilization 34 3.20.7.2.2 Boron and lithium isotopes 35 3.20.7.3 Carbon and Nitrogen forearcs. In addi- tion, subduction erosion from the forearc hanging walls can impact geochemical evolut

Bebout, Gray E.

280

5, 547577, 2008 Isotope hydrology of  

E-Print Network [OSTI]

HESSD 5, 547­577, 2008 Isotope hydrology of cave dripwaters L. Fuller et al. Title Page Abstract.hydrol-earth-syst-sci-discuss.net/5/547/2008/ © Author(s) 2008. This work is licensed under a Creative Commons License. Hydrology and Earth System Sciences Discussions Papers published in Hydrology and Earth System Sciences Discussions

Boyer, Edmond

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Radioactive isotopes in Danish drinking water  

E-Print Network [OSTI]

Radioactive isotopes in Danish drinking water Sven P. Nielsen Risø National Laboratory Working OF INVESTIGATION 11 3 DESCRIPTION OF INVESTIGATION 12 4 RADIOACTIVITY IN DRINKING WATER 13 5 SAMPLING 15 6 27 #12;4 #12;5 Preface This project for investigation of radioactivity in drinking water shall

282

Validation of Electrochemically Modulated Separations Performed On-Line with MC-ICP-MS for Uranium and Plutonium Isotopic Analyses  

SciTech Connect (OSTI)

The most time consuming process in uranium or plutonium isotopic analyses is performing the requisite chromatographic separation of the actinides. Filament preparation for thermal ionization (TIMS) adds further delays, but is generally accepted due to the unmatched performance in trace isotopic analyses. Advances in Multi-Collector Inductively Coupled Plasma Mass Spectrometry (MC-ICP-MS) are beginning to rival the performance of TIMS. Methods, such as Electrochemically Modulated Separations (EMS) can efficiently pre-concentrate U or Pu quite selectively from small solution volumes in a matrix of 0.5 M nitric acid. When performed in-line with ICP-MS, the rapid analyte release from the electrode is fast, and large transient analyte signal enhancements of >100 fold can be achieved as compared to more conventional continuous nebulization of the original starting solution. This makes the approach ideal for very low level isotope ratio measurements. In this paper, some aspects of EMS performance are described. These include low level Pu isotope ratio behavior versus concentration by MC-ICP-MS and uranium rejection characteristics that are also important for reliable low level Pu isotope ratio determinations.

Liezers, Martin; Olsen, Khris B.; Mitroshkov, Alexandre V.; Duckworth, Douglas C.

2010-08-11T23:59:59.000Z

283

Carbon IsotopesCarbon Isotopes A Short Course VU March, 2009  

E-Print Network [OSTI]

. Historical CO2 record from the Vostok ice core. In Trends: A Compendium of Data on Global Change. Carbon · Bitumen · Coal Range of Carbon Isotopes PDB Hoefs 1982 #12;2/25/2009 3 Range of Carbon Isotopes PDB Hoefs 1982 12CO2 Photosynthesis 12CO2 Respiration 13CO2 CO2+ RUBP = PGA (=27) RUBISCO #12;2/25/2009 4

Miami, University of

284

MAGNESIUM ISOTOPE EVIDENCE FOR SINGLE STAGE FORMATION OF CB CHONDRULES BY COLLIDING PLANETESIMALS  

SciTech Connect (OSTI)

Chondrules are igneous spherical objects preserved in chondritic meteorites and believed to have formed during transient heating events in the solar protoplanetary disk. Chondrules present in the metal-rich CB chondrites show unusual chemical and petrologic features not observed in other chondrite groups, implying a markedly distinct formation mechanism. Here, we report high-precision Mg-isotope data for 10 skeletal olivine chondrules from the Hammadah al Hamra 237 (HH237) chondrite to probe the formation history of CB chondrules. The {sup 27}Al/{sup 24}Mg ratios of individual chondrules are positively correlated to their stable Mg-isotope composition (?{sup 25}Mg), indicating that the correlated variability was imparted by a volatility-controlled process (evaporation/condensation). The mass-independent {sup 26}Mg composition (?{sup 26}Mg*) of chondrules is consistent with single stage formation from an initially homogeneous magnesium reservoir if the observed ?{sup 25}Mg variability was generated by non-ideal Rayleigh-type evaporative fractionation characterized by a ? value of 0.5142, in agreement with experimental work. The magnitude of the mass-dependent fractionation (?300 ppm) is significantly lower than that suggested by the increase in {sup 27}Al/{sup 24}Mg values, indicating substantial suppression of isotopic fractionation during evaporative loss of Mg, possibly due to evaporation at high Mg partial pressure. Thus, the Mg-isotope data of skeletal chondrules from HH237 are consistent with their origin as melts produced in the impact-generated plume of colliding planetesimals. The inferred ?{sup 26}Mg* value of –3.87 ± 0.93 ppm for the CB parent body is significantly lower than the bulk solar system value of 4.5 ± 1.1 ppm inferred from CI chondrites, suggesting that CB chondrites accreted material comprising an early formed {sup 26}Al-free component.

Olsen, Mia B.; Schiller, Martin; Krot, Alexander N.; Bizzarro, Martin [Centre for Star and Planet Formation, Natural History Museum of Denmark, University of Copenhagen, Copenhagen DK-1350 (Denmark)] [Centre for Star and Planet Formation, Natural History Museum of Denmark, University of Copenhagen, Copenhagen DK-1350 (Denmark)

2013-10-10T23:59:59.000Z

285

Method of enhancing selective isotope desorption from metals  

DOE Patents [OSTI]

A method of enhancing the thermal desorption of a first isotope of a diatomic gas from a metal comprises the steps of (a) establishing a partial pressure of a second isotope of the diatomic gas in vicinity of the metal; heating the metal to a temperature such that the first isotope is desorbed from the metal; and reducing the partial pressure of the desorbed first isotope while maintaining the partial pressure of the second isotope substantially constant. The method is especially useful for enhancing the desorption of tritium from the Zr-Al getter in a plasma confinement device.

Knize, Randall J. (Plainsboro, NJ); Cecchi, Joseph L. (Lawrenceville, NJ)

1984-01-01T23:59:59.000Z

286

Benchmark of SCALE (SAS2H) isotopic predictions of depletion analyses for San Onofre PWR MOX fuel  

SciTech Connect (OSTI)

The isotopic composition of mixed-oxide (MOX) fuel, fabricated with both uranium and plutonium, after discharge from reactors is of significant interest to the Fissile Materials Disposition Program. The validation of the SCALE (SAS2H) depletion code for use in the prediction of isotopic compositions of MOX fuel, similar to previous validation studies on uranium-only fueled reactors, has corresponding significance. The EEI-Westinghouse Plutonium Recycle Demonstration Program examined the use of MOX fuel in the San Onofre PWR, Unit 1, during cycles 2 and 3. Isotopic analyses of the MOX spent fuel were conducted on 13 actinides and {sup 148}Nd by either mass or alpha spectrometry. Six fuel pellet samples were taken from four different fuel pins of an irradiated MOX assembly. The measured actinide inventories from those samples has been used to benchmark SAS2H for MOX fuel applications. The average percentage differences in the code results compared with the measurement were {minus}0.9% for {sup 235}U and 5.2% for {sup 239}Pu. The differences for most of the isotopes were significantly larger than in the cases for uranium-only fueled reactors. In general, comparisons of code results with alpha spectrometer data had extreme differences, although the differences in the calculations compared with mass spectrometer analyses were not extremely larger than that of uranium-only fueled reactors. This benchmark study should be useful in estimating uncertainties of inventory, criticality and dose calculations of MOX spent fuel.

Hermann, O.W.

2000-02-01T23:59:59.000Z

287

Method of preparing mercury with an arbitrary isotopic distribution  

DOE Patents [OSTI]

This invention provides for a process for preparing mercury with a predetermined, arbitrary, isotopic distribution. In one embodiment, different isotopic types of Hg[sub 2]Cl[sub 2], corresponding to the predetermined isotopic distribution of Hg desired, are placed in an electrolyte solution of HCl and H[sub 2]O. The resulting mercurous ions are then electrolytically plated onto a cathode wire producing mercury containing the predetermined isotopic distribution. In a similar fashion, Hg with a predetermined isotopic distribution is obtained from different isotopic types of HgO. In this embodiment, the HgO is dissolved in an electrolytic solution of glacial acetic acid and H[sub 2]O. The isotopic specific Hg is then electrolytically plated onto a cathode and then recovered. 1 fig.

Grossman, M.W.; George, W.A.

1986-12-16T23:59:59.000Z

288

Method of preparing mercury with an arbitrary isotopic distribution  

DOE Patents [OSTI]

This invention provides for a process for preparing mercury with a predetermined, arbitrary, isotopic distribution. In one embodiment, different isotopic types of Hg.sub.2 Cl.sub.2, corresponding to the predetermined isotopic distribution of Hg desired, are placed in an electrolyte solution of HCl and H.sub.2 O. The resulting mercurous ions are then electrolytically plated onto a cathode wire producing mercury containing the predetermined isotopic distribution. In a similar fashion, Hg with a predetermined isotopic distribution is obtained from different isotopic types of HgO. In this embodiment, the HgO is dissolved in an electrolytic solution of glacial acetic acid and H.sub.2 O. The isotopic specific Hg is then electrolytically plated onto a cathode and then recovered.

Grossman, Mark W. (Belmont, MA); George, William A. (Rockport, MA)

1986-01-01T23:59:59.000Z

289

Physics with Rare Isotope Beams  

SciTech Connect (OSTI)

Using stable and radioactive beams provided by ATLAS nuclear reactions of special interest in astrophysics have been studied with emphasis on breakout from the hot CNO cycle to the rp-process. The masses of nuclear fragments provided by a strong fission source have been measured in order to help trace the path of the r process. 8Li ions produced by the d(7Li,8Li)n reaction have been trapped and the electrons and alphas emitted in the ensuing beta-decay measured. The neutrino directions were therefore determined, which leads to a measurement of the electron-neutrino correlation. The energies and kinematics are such that a sensitive search for any tensor admixture could be performed and an upper limit of 0.6% was placed on any such admixture. Earlier work on the electromagnetic form factors of the proton was extended. Graduate students were active participants in all of these eperiments, which formed the basis for six PhD theses.

Segel, Ralph E. [Northwestern University] [Northwestern University

2013-11-08T23:59:59.000Z

290

Measurement of Ultra-Low Potassium Contaminations with Accelerator Mass Spectrometry  

E-Print Network [OSTI]

Levels of trace radiopurity in active detector materials is a subject of major concern in low-background experiments. Among the radio-isotopes, $\\k40$ is one of the most abundant and yet whose signatures are difficult to reject. Procedures were devised to measure trace potassium concentrations in the inorganic salt CsI as well as in organic liquid scintillator (LS) with Accelerator Mass Spectrometry (AMS), giving, respectively, the $\\k40$-contamination levels of $\\sim 10^{-10}$ and $\\sim 10^{-13}$ g/g. Measurement flexibilities and sensitivities are improved over conventional methods. The projected limiting sensitivities if no excess of potassium signals had been observed over background are $8 \\times 10^{-13}$ g/g and $3 \\times 10^{-17}$ g/g for the CsI and LS, respectively. Studies of the LS samples indicate that the radioactive contaminations come mainly in the dye solutes, while the base solvents are orders of magnitude cleaner. The work demonstrate the possibilities of measuring naturally-occurring isoto...

Dong, K J

2007-01-01T23:59:59.000Z

291

Use of plutonium isotope activity ratios in dating recent sediments. [/sup 238/Pu//sup 239/Pu + /sup 240/Pu  

SciTech Connect (OSTI)

The majority of plutonium presently in the biosphere has come from the testing of nuclear devices. In the early 1950s, the Pu-238/239+240 activity ratio of fallout debris was > 0.04; in the more extensive test series of 1961 to 1962, the Pu-238/239+240 activity ratios were quite consistent at 0.02 to 0.03 and maximum fallout delivery occurred in mid-1963. A significant perturbation in Pu isotope activity ratios occurred in mid-1966 with the deposition of Pu-238 from the SNAP-9A reentry and burn-up. Recently deposited sediments have recorded these events and where accumulation rates are rapid (> 1 cm/y), changes in Pu isotope activity ratios can be used as a geochronological tool.

Beasley, T. M.

1982-01-01T23:59:59.000Z

292

Stable carbon isotope ratio of polycyclic aromatic hydrocarbons (PAHs) in the environment: validation of isolation and stable carbon isotope analysis methods  

E-Print Network [OSTI]

, purification and compound specific isotope analysis methods were developed to accurately measure the stable carbon isotope ratio of individual PAHs. Development of the method included improving accuracy and precision of the isotopic measurement by producing...

Kim, Moon Koo

2004-11-15T23:59:59.000Z

293

Radiation port dermatophytosis: Tinea corporis occurring at the site of irradiated skin  

E-Print Network [OSTI]

M, Huang J, Arous E: Radiation therapy toxicity to the skin.Radiation port dermatophytosis: Tinea corporis occurring atHouston, Texas Abstract Radiation port dermatophytosis is

Casamiquela, Kathleen M; Cohen, Philip R

2012-01-01T23:59:59.000Z

294

E-Print Network 3.0 - accident excursion occurring Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

University Collection: Geosciences 4 U of L Campus AccidentIncident Report Automobile AccidentIncident Page 1 of 2 University of Lethbridge Summary: accidents that occur...

295

E-Print Network 3.0 - annually occurring aerosol Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

in Radiative Transfer Encyclopedia of Atmospheric Science Summary: system. Naturally occurring aerosols reflect some of the incident solar radiation back to space before... in...

296

Radiation port dermatophytosis: Tinea corporis occurring at the site of irradiated skin  

E-Print Network [OSTI]

Radiation port dermatophytosis: Tinea corporis occurring atTexas Abstract Radiation port dermatophytosis is thethe area of the radiotherapy port. Including this patient, 4

Casamiquela, Kathleen M; Cohen, Philip R

2012-01-01T23:59:59.000Z

297

The atoms may be charged or neutral (how?) mass range: 1.67 10-27  

E-Print Network [OSTI]

: where does our food come from? different plants have a different isotope content What other uses (2008) *mention UCSB project "Children of the corn" #12; Can we get energy from atoms? ... fusion and fission "The sun is a mass of incandescent gas A gigantic nuclear furnace Where hydrogen is built

298

Importance of the Equlibrium Node in Preventing the Voltage Collapse Occurs in the Wind Power System  

E-Print Network [OSTI]

Importance of the Equlibrium Node in Preventing the Voltage Collapse Occurs in the Wind Power collapse will occurs in a wind power system is discussed next. The method of power flow calculation is the specific analysis of a given simplified wind power system. Keywords--voltage collapse; Newton

Lavaei, Javad

299

Conditioning-specific reflex modification occurs when an unconditionedresponse(UR)ismodifiedinthe absence  

E-Print Network [OSTI]

not generalize from air puff to electro- dermal stimulation even though conditioning occurs to comparable levels can be obtained only at high air puff intensi- ties even though conditioning is supported by lower airConditioning-specific reflex modification occurs when an unconditionedresponse

300

Diffusional exchange of isotopes in a metal hydride sphere.  

SciTech Connect (OSTI)

This report describes the Spherical Particle Exchange Model (SPEM), which simulates exchange of one hydrogen isotope by another hydrogen isotope in a spherical metal hydride particle. This is one of the fundamental physical processes during isotope exchange in a bed of spherical metal particles and is thus one of the key components in any comprehensive physics-based model of exchange. There are two important physical processes in the model. One is the entropy of mixing between the two isotopes; the entropy of mixing is increased by having both isotopes randomly placed at interstitial sites on the lattice and thus impedes the exchange process. The other physical process is the elastic interaction between isotope atoms on the lattice. The elastic interaction is the cause for {beta}-phase formation and is independent of the isotope species. In this report the coupled diffusion equations for two isotopes in the {beta}-phase hydride are solved. A key concept is that the diffusion of one isotope depends not only on its concentration gradient, but also on the concentration gradient of the other isotope. Diffusion rate constants and the chemical potentials for deuterium and hydrogen in the {beta}-phase hydride are reviewed because these quantities are essential for an accurate model of the diffusion process. Finally, a summary of some of the predictions from the SPEM model are provided.

Wolfer, Wilhelm G.; Hamilton, John C.; James, Scott Carlton

2011-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Isotopic noble gas signatures released from medical isotope production facilities - Simulations and measurements  

SciTech Connect (OSTI)

Journal article on the role that radioxenon isotopes play in confirming whether or not an underground explosion was nuclear in nature. Radioxenon isotopes play a major role in confirming whether or not an underground explosion was nuclear in nature. It is then of key importance to understand the sources of environmental radioxenon to be able to distinguish civil sources from those of a nuclear explosion. Based on several years of measurements, combined with advanced atmospheric transport model results, it was recently shown that the main source of radioxenon observations are strong and regular batch releases from a very limited number of medical isotope production facilities. This paper reviews production processes in different medical isotope facilities during which radioxenon is produced. Radioxenon activity concentrations and isotopic compositions are calculated for six large facilities. The results are compared with calculated signals from nuclear explosions. Further, the outcome is compared and found to be consistent with radioxenon measurements recently performed in and around three of these facilities. Some anomalies in measurements in which {sup 131m}Xe was detected were found and a possible explanation is proposed. It was also calculated that the dose rate of the releases is well below regulatory values. Based on these results, it should be possible to better understand, interpret and verify signals measured in the noble gas measurement systems in the International Monitoring of the Comprehensive Nuclear-Test-Ban Treaty.

Saey, Paul R.; Bowyer, Ted W.; Ringbom, Anders

2010-09-09T23:59:59.000Z

302

Neutrinoless Double Beta Decay with Negligible Neutrino Mass  

E-Print Network [OSTI]

If the electron neutrino has an effective nonzero Majorana mass, then neutrinoless double beta decay will occur. However, the latter is possible also with a negligible neutrino mass. We show how this may happen in a simple model of scalar diquarks and dileptons. This possibility allows neutrino masses to be small and hierarchical, without conflicting with the possible experimental evidence of neutrinoless double beta decay.

Biswajoy Brahmachari; Ernest Ma

2002-02-27T23:59:59.000Z

303

Elbow mass flow meter  

DOE Patents [OSTI]

Elbow mass flow meter. The present invention includes a combination of an elbow pressure drop generator and a shunt-type mass flow sensor for providing an output which gives the mass flow rate of a gas that is nearly independent of the density of the gas. For air, the output is also approximately independent of humidity.

McFarland, Andrew R. (College Station, TX); Rodgers, John C. (Santa Fe, NM); Ortiz, Carlos A. (Bryan, TX); Nelson, David C. (Santa Fe, NM)

1994-01-01T23:59:59.000Z

304

High Flux Isotope Reactor power upgrade status  

SciTech Connect (OSTI)

A return to 100-MW operation is being planned for the High Flux Isotope Reactor (HFIR). Recent improvements in fuel element manufacturing procedures and inspection equipment will be exploited to reduce hot spot and hot streak factors sufficiently to permit the power upgrade without an increase in primary coolant pressure. Fresh fuel elements already fabricated for future use are being evaluated individually for power upgrade potential based on their measured coolant channel dimensions.

Rothrock, R.B.; Hale, R.E. [Oak Ridge National Lab., TN (United States); Cheverton, R.D. [Delta-21 Resources Inc., Oak Ridge, TN (United States)

1997-03-01T23:59:59.000Z

305

Concerning the Facility for Rare Isotope Beams  

ScienceCinema (OSTI)

James Symons, Nuclear Science Division Director at Lawrence Berkeley Lab, and Daniela Leitner, head of operations at Berkeley Lab's 88-Inch Cyclotron, discuss major contributions to the new Facility for Rare Isotope Beams (FRIB) at Michigan State University, including ion source, which will based on the VENUS source built for the 88-Inch Cyclotron, and the GRETA gamma-ray detector now under construction there.

Symons, James

2013-05-29T23:59:59.000Z

306

Optically pumped isotopic ammonia laser system  

DOE Patents [OSTI]

An optically pumped isotopic ammonia laser system which is capable of producing a plurality of frequencies in the middle infrared spectral region. Two optical pumping mechanisms are disclosed, i.e., pumping on R(J) and lasing on P(J) in response to enhancement of rotational cascade lasing including stimulated Raman effects, and, pumping on R(J) and lasing on P(J+2). The disclosed apparatus for optical pumping include a hole coupled cavity and a grating coupled cavity.

Buchwald, Melvin I. (Santa Fe, NM); Jones, Claude R. (Los Alamos, NM); Nelson, Leonard Y. (Seattle, WA)

1982-01-01T23:59:59.000Z

307

Small system for tritium accelerator mass spectrometry  

DOE Patents [OSTI]

Apparatus for ionizing and accelerating a sample containing isotopes of hydrogen and detecting the ratios of hydrogen isotopes contained in the sample is disclosed. An ion source generates a substantially linear ion beam including ions of tritium from the sample. A radio-frequency quadrupole accelerator is directly coupled to and axially aligned with the source at an angle of substantially zero degrees. The accelerator accelerates species of the sample having different mass to different energy levels along the same axis as the ion beam. A spectrometer is used to detect the concentration of tritium ions in the sample. In one form of the invention, an energy loss spectrometer is used which includes a foil to block the passage of hydrogen, deuterium and .sup.3 He ions, and a surface barrier or scintillation detector to detect the concentration of tritium ions. In another form of the invention, a combined momentum/energy loss spectrometer is used which includes a magnet to separate the ion beams, with Faraday cups to measure the hydrogen and deuterium and a surface barrier or scintillation detector for the tritium ions.

Roberts, Mark L. (Livermore, CA); Davis, Jay C. (Livermore, CA)

1993-01-01T23:59:59.000Z

308

Small system for tritium accelerator mass spectrometry  

DOE Patents [OSTI]

Apparatus for ionizing and accelerating a sample containing isotopes of hydrogen and detecting the ratios of hydrogen isotopes contained in the sample is disclosed. An ion source generates a substantially linear ion beam including ions of tritium from the sample. A radio-frequency quadrupole accelerator is directly coupled to and axially aligned with the source at an angle of substantially zero degrees. The accelerator accelerates species of the sample having different mass to different energy levels along the same axis as the ion beam. A spectrometer is used to detect the concentration of tritium ions in the sample. In one form of the invention, an energy loss spectrometer is used which includes a foil to block the passage of hydrogen, deuterium and [sup 3]He ions, and a surface barrier or scintillation detector to detect the concentration of tritium ions. In another form of the invention, a combined momentum/energy loss spectrometer is used which includes a magnet to separate the ion beams, with Faraday cups to measure the hydrogen and deuterium and a surface barrier or scintillation detector for the tritium ions.

Roberts, M.L.; Davis, J.C.

1993-02-23T23:59:59.000Z

309

Hydrogen isotope separation utilizing bulk getters  

DOE Patents [OSTI]

Tritium and deuterium are separated from a gaseous mixture thereof, derived from a nuclear fusion reactor or some other source, by providing a casing with a bulk getter therein for absorbing the gaseous mixture to produce an initial loading of the getter, partially desorbing the getter to produce a desorbed mixture which is tritium-enriched, pumping the desorbed mixture into a separate container, the remaining gaseous loading in the getter being deuterium-enriched, desorbing the getter to a substantially greater extent to produce a deuterium-enriched gaseous mixture, and removing the deuterium-enriched mixture into another container. The bulk getter may comprise a zirconium-aluminum alloy, or a zirconium-vanadium-iron alloy. The partial desorption may reduce the loading by approximately fifty percent. The basic procedure may be extended to produce a multistage isotope separator, including at least one additional bulk getter into which the tritium-enriched mixture is absorbed. The second getter is then partially desorbed to produce a desorbed mixture which is further tritium-enriched. The last-mentioned mixture is then removed from the container for the second getter, which is then desorbed to a substantially greater extent to produce a desorbed mixture which is deuterium-enriched. The last-mentioned mixture is then removed so that the cycle can be continued and repeated. The method of isotope separation is also applicable to other hydrogen isotopes, in that the method can be employed for separating either deuterium or tritium from normal hydrogen.

Knize, Randall J. (Los Angeles, CA); Cecchi, Joseph L. (Lawrenceville, NJ)

1991-01-01T23:59:59.000Z

310

Hydrogen isotope separation utilizing bulk getters  

DOE Patents [OSTI]

Tritium and deuterium are separated from a gaseous mixture thereof, derived from a nuclear fusion reactor or some other source, by providing a casing with a bulk getter therein for absorbing the gaseous mixture to produce an initial loading of the getter, partially desorbing the getter to produce a desorbed mixture which is tritium-enriched, pumping the desorbed mixture into a separate container, the remaining gaseous loading in the getter being deuterium-enriched, desorbing the getter to a substantially greater extent to produce a deuterium-enriched gaseous mixture, and removing the deuterium-enriched mixture into another container. The bulk getter may comprise a zirconium-aluminum alloy, or a zirconium-vanadium-iron alloy. The partial desorption may reduce the loading by approximately fifty percent. The basic procedure may be extended to produce a multistage isotope separator, including at least one additional bulk getter into which the tritium-enriched mixture is absorbed. The second getter is then partially desorbed to produce a desorbed mixture which is further tritium-enriched. The last-mentioned mixture is then removed from the container for the second getter, which is then desorbed to a substantially greater extent to produce a desorbed mixture which is deuterium-enriched. The last-mentioned mixture is then removed so that the cycle can be continued and repeated. The method of isotope separation is also applicable to other hydrogen isotopes, in that the method can be employed for separating either deuterium or tritium from normal hydrogen.

Knize, Randall J. (Los Angeles, CA); Cecchi, Joseph L. (Lawrenceville, NJ)

1990-01-01T23:59:59.000Z

311

Hydrogen isotope separation utilizing bulk getters  

DOE Patents [OSTI]

Tritium and deuterium are separated from a gaseous mixture thereof, derived from a nuclear fusion reactor or some other source, by providing a casing with a bulk getter therein for absorbing the gaseous mixture to produce an initial loading of the getter, partially desorbing the getter to produce a desorbed mixture which is tritium-enriched, pumping the desorbed mixture into a separate container, the remaining gaseous loading in the getter being deuterium-enriched, desorbing the getter to a substantially greater extent to produce a deuterium-enriched gaseous mixture, and removing the deuterium-enriched mixture into another container. The bulk getter may comprise a zirconium-aluminum alloy, or a zirconium-vanadium-iron alloy. The partial desorption may reduce the loading by approximately fifty percent. The basic procedure may be extended to produce a multistage isotope separator, including at least one additional bulk getter into which the tritium-enriched mixture is absorbed. The second getter is then partially desorbed to produce a desorbed mixture which is further tritium-enriched. The last-mentioned mixture is then removed from the container for the second getter, which is then desorbed to a substantially greater extent to produce a desorbed mixture which is deuterium-enriched. The last-mentioned mixture is then removed so that the cycle can be continued and repeated. The method of isotope separation is also applicable to other hydrogen isotopes, in that the method can be employed for separating either deuterium or tritium from normal hydrogen. 4 figures.

Knize, R.J.; Cecchi, J.L.

1991-08-20T23:59:59.000Z

312

Excitation energy and strength of the pygmy dipole resonance in stable tin isotopes  

E-Print Network [OSTI]

The $^{112,120}$Sn$(\\gamma,\\gamma')$ reactions have been studied at the S-DALINAC. Electric dipole (E1) strength distributions have been determined including contributions from unresolved strength extracted by a fluctuation analysis. Together with available data on $^{116,124}$Sn, an experimental systematics of the pygmy dipole resonance (PDR) in stable even-mass tin isotopes is established. The PDR centroid excitation energies and summed strengths are in reasonable agreement with quasiparticle-phonon model calculations based on a nonrelativistic description of the mean field but disagree with relativistic quasiparticle random-phase approximation predictions.

B. Özel; J. Enders; H. Lenske; P. von Neumann-Cosel; I. Poltoratska; V. Yu. Ponomarev; A. Richter; D. Savran; N. Tsoneva

2009-01-16T23:59:59.000Z

313

Nonadiabatic calculations of ultraviolet absorption cross section of sulfur monoxide: Isotopic effects on the photodissociation reaction  

SciTech Connect (OSTI)

Ultraviolet absorption cross sections of the main and substituted sulfur monoxide (SO) isotopologues were calculated using R-Matrix expansion technique. Energies, transition dipole moments, and nonadiabatic coupling matrix elements were calculated at MRCI/AV6Z level. The calculated absorption cross section of {sup 32}S{sup 16}O was compared with experimental spectrum; the spectral feature and the absolute value of photoabsorption cross sections are in good agreement. Our calculation predicts a long lived photoexcited SO* species which causes large non-mass dependent isotopic effects depending on the excitation energy in the ultraviolet region.

Danielache, Sebastian O.; Tomoya, Suzuki; Nanbu, Shinkoh [Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, Chiyoda Ku, Tokyo 102-8554 (Japan)] [Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, Chiyoda Ku, Tokyo 102-8554 (Japan); Kondorsky, Alexey [P. N. Lebedev Physical Institute of Russian Academy of Science, Leninsky pr., 53, Moscow, 119991 (Russian Federation) [P. N. Lebedev Physical Institute of Russian Academy of Science, Leninsky pr., 53, Moscow, 119991 (Russian Federation); Moscow Institute of Physics and Technology (State University), Institutsky per., 9, Dolgoprudny Moscow region, 141700 (Russian Federation); Tokue, Ikuo [Department of Chemistry, Faculty of Science, Niigata University, Ikarashi, Niigata 950-2181 (Japan)] [Department of Chemistry, Faculty of Science, Niigata University, Ikarashi, Niigata 950-2181 (Japan)

2014-01-28T23:59:59.000Z

314

Beta-decay properties of Zr and Mo neutron-rich isotopes  

E-Print Network [OSTI]

Gamow-Teller strength distributions, beta-decay half-lives, and beta-delayed neutron emission are investigated in neutron-rich Zr and Mo isotopes within a deformed quasiparticle random-phase approximation. The approach is based on a self-consistent Skyrme Hartree-Fock mean field with pairing correlations and residual separable particle-hole and particle-particle forces. Comparison with recent measurements of half-lives stresses the important role that nuclear deformation plays in the description of beta-decay properties in this mass region.

P. Sarriguren; J. Pereira

2010-06-08T23:59:59.000Z

315

Coal fly ash interaction with environmental fluids: Geochemical and strontium isotope results from combined column and batch leaching experiments  

SciTech Connect (OSTI)

The major element and Sr isotope systematics and geochemistry of coal fly ash and its interactions with environmental waters were investigated using laboratory flow-through column leaching experiments (sodium carbonate, acetic acid, nitric acid) and sequential batch leaching experiments (water, acetic acid, hydrochloric acid). Column leaching of Class F fly ash samples shows rapid release of most major elements early in the leaching procedure, suggesting an association of these elements with soluble and surface bound phases. Delayed release of certain elements (e.g., Al, Fe, Si) signals gradual dissolution of more resistant silicate or glass phases as leaching continues. Strontium isotope results from both column and batch leaching experiments show a marked increase in {sup 87}Sr/{sup 86}Sr ratio with continued leaching, yielding a total range of values from 0.7107 to 0.7138. For comparison, the isotopic composition of fluid output from a fly ash impoundment in West Virginia falls in a narrow range around 0.7124. The experimental data suggest the presence of a more resistant, highly radiogenic silicate phase that survives the combustion process and is leached after the more soluble minerals are removed. Strontium isotopic homogenization of minerals in coal does not always occur during the combustion process, despite the high temperatures encountered in the boiler. Early-released Sr tends to be isotopically uniform; thus the Sr isotopic composition of fly ash could be distinguishable from other sources and is a useful tool for quantifying the possible contribution of fly ash leaching to the total dissolved load in natural surface and ground waters.

Brubaker, Tonya M.; Stewart, Brian W.; Capo, Rosemary C.; Schroeder, Karl T.; Chapman, Elizabeth C.; Spivak-Birndorf, Lev J.; Vesper, Dorothy J.; Cardone, Carol R.; Rohar, Paul C.

2013-05-01T23:59:59.000Z

316

Magnesium isotopic systematics of chondrules and CAIs from Allende, Murchison, Murray and Bjurbole. F.-, M. Wadhwa1,  

E-Print Network [OSTI]

Magnesium isotopic systematics of chondrules and CAIs from Allende, Murchison, Murray and Bjurbole: Magnesium isotopic analyses were performed at the Isotope Geochemistry Labora- tory of the Field Museum

Grossman, Lawrence

317

Quark masses, the Dashen phase, and gauge field topology  

SciTech Connect (OSTI)

The CP violating Dashen phase in QCD is predicted by chiral perturbation theory to occur when the up–down quark mass difference becomes sufficiently large at fixed down-quark mass. Before reaching this phase, all physical hadronic masses and scattering amplitudes are expected to behave smoothly with the up-quark mass, even as this mass passes through zero. In Euclidean space, the topological susceptibility of the gauge fields is positive at positive quark masses but diverges to negative infinity as the Dashen phase is approached. A zero in this susceptibility provides a tentative signal for the point where the mass of the up quark vanishes. I discuss potential ambiguities with this determination. -- Highlights: •The CP violating Dashen phase in QCD occurs when the up quark mass becomes sufficiently negative. •Before reaching this phase, all physical hadronic masses and scattering amplitudes behave smoothly with the up-quark mass. •The topological susceptibility of the gauge fields diverges to negative infinity as the Dashen phase is approached. •A zero in the topological susceptibility provides a tentative signal for the point where the mass of the up quark vanishes. •The universality of this definition remains unproven. Potential ambiguities are discussed.

Creutz, Michael, E-mail: creutz@bnl.gov

2013-12-15T23:59:59.000Z

318

RFNC-VNIIEF Capabilities to Production High Pure Isotopes for Scientific and Medical Applications  

SciTech Connect (OSTI)

In the technical paper there is presented the information on the basic equipment and more than thirty-year experience of RFNC-VNIIEF activities in the sphere of producing highly enriched isotopes of actinide elements--thorium, uranium, neptunium, plutonium, americium and curium--for scientific researches and practical applications. Electromagnetic separator and radiochemical methods provide obtaining of superpure isotope samples for nuclear-physical radiometric and mass-spectrometric equipment, and also as tracers when analyzing environmental contamination. There are presented the structure of the laboratory occupied with these isotopes electromagnetic separation as well as the nomenclature and characteristics of the specimens supplied. There are stated science and engineering elaborations of technologies aimed at producing alpha-ray radiating radionuclides--thorium-229, thorium-228, actinium-225, radium-224--for the purpose of anti-cancer therapy using bismuth-212 and bismuth-213 produced by the specially developed generators. There are presented the basic directions of cooperation with other Russian Institutes in developing this promising line of conversion.

Vesnovskii, S. P.

2002-02-26T23:59:59.000Z

319

SIEMENS ADVANCED QUANTRA FTICR MASS SPECTROMETER FOR ULTRA HIGH RESOLUTION AT LOW MASS  

SciTech Connect (OSTI)

The Siemens Advanced Quantra Fourier Transform Ion Cyclotron Resonance (FTICR) mass spectrometer was evaluated as an alternative instrument to large double focusing mass spectrometers for gas analysis. High resolution mass spectrometers capable of resolving the common mass isomers of the hydrogen isotopes are used to provide data for accurate loading of reservoirs and to monitor separation of tritium, deuterium, and helium. Conventional double focusing magnetic sector instruments have a resolution that is limited to about 5000. The Siemens FTICR instrument achieves resolution beyond 400,000 and could possibly resolve the tritium ion from the helium-3 ion, which differ by the weight of an electron, 0.00549 amu. Working with Y-12 and LANL, SRNL requested Siemens to modify their commercial Quantra system for low mass analysis. To achieve the required performance, Siemens had to increase the available waveform operating frequency from 5 MHz to 40 MHz and completely redesign the control electronics and software. However, they were able to use the previous ion trap, magnet, passive pump, and piezo-electric pulsed inlet valve design. NNSA invested $1M in this project and acquired four systems, two for Y-12 and one each for SRNL and LANL. Siemens claimed a $10M investment in the Quantra systems. The new Siemens Advanced Quantra demonstrated phenomenal resolution in the low mass range. Resolution greater than 400,000 was achieved for mass 2. The new spectrometer had a useful working mass range to 500 Daltons. However, experiments found that a continuous single scan from low mass to high was not possible. Two useful working ranges were established covering masses 1 to 6 and masses 12 to 500 for our studies. A compromise performance condition enabled masses 1 to 45 to be surveyed. The instrument was found to have a dynamic range of about three orders of magnitude and quantitative analysis is expected to be limited to around 5 percent without using complex fitting algorithms. Analysis of low concentration ions, at the ppm level, required a separate analysis using ion ejection techniques. Chemical ionization due to the formation of the MH{sup +} ion or MD{sup +} increased the complexity of the spectra compared to magnetic sector mass spectra and formation of the protonated or deuterated complex was a dynamic function of the trap ion concentration. This made quantitative measurement more of a challenge. However, the resolution of the instrument was far superior to any other mass spectrometry technique that has been applied to the analysis of the hydrogen isotopes. The piezo-electric picoliter injection device offers a new way of submitting small quantities of atmospheric pressure sample gas for analysis. The new software had many improvements over the previous version but significant flaws in the beta codes remain that make the prototype units less than ideal. The instrument is a promising new technology that experience will likely improve. Unfortunately, Siemens has concluded that the technology will not be a commercial success and has decided to stop producing this product.

Spencer, W; Laura Tovo, L

2008-07-08T23:59:59.000Z

320

Conditions under which cracks occur in modified 13% chromium steel in wet hydrogen sulfide environments  

SciTech Connect (OSTI)

Occurrence of cracks in an API 13% Cr steel, modified 13% Cr steel, and duplex stainless steel were compared in various wet, mild hydrogen sulfide (H{sub 2}S) environments. The conditions under which cracks occurred in the modified 13% Cr steel in oil and gas production environments were made clear. No cracks occurred if pH > depassivation pH (pH{sub d}) and redox potential of sulfur (E{sub S(red/ax)}) < pitting potential (V{sub c}). Hydrogen embrittlement-type cracks occurred in pH > Ph{sub d} and E{sub S(red/ax)} > V{sub c}. The pH inside the pit decreased drastically and hydrogen embrittlement occurred. Cracks of the hydrogen embrittlement type occurred if pH < pH{sub d} and threshold hydrogen concentration under which cracks occur (H{sub th}) < hydrogen concentration in steel (H{sub 0}). No cracks occurred if pH < pH{sub d} and H{sub th} > H{sub 0}.

Hara, T.; Asahi, H.

2000-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Climate change deduced from isotopes in tree rings  

SciTech Connect (OSTI)

This paper describes the theory of carbon, hydrogen, and oxygen isotopic signatures in cellulose for the purpose of paleoclimatic reconstruction. Mechanisms governing tree ring cellulose isotopic variability are investigated, and applications to the southwestern United States are delineated. A monitoring program of pinyon trees and comparison to climatic parameters is briefly described. Variables measured included deviations in hydrogen and oxygen-18 isotopic composition in precipitation, soil water, stem and leaf water, and atmospheric vapor. Water from phloem tissue was found to be isotopically identical to the xylem sap, suggesting that cellulose precursors can exchange isotopically with source water before cellulose is made in the trunk, thus removing most of the isotopic signal from the leaves. Overall results suggest that, on arid sites in the southwestern US receiving adequate summer rain, a precipitation seasonality signal may be recorded. 21 refs., 2 figs.

Pendall, E.G.; Leavitt, S.W.

1997-11-01T23:59:59.000Z

322

System and method for high precision isotope ratio destructive analysis  

DOE Patents [OSTI]

A system and process are disclosed that provide high accuracy and high precision destructive analysis measurements for isotope ratio determination of relative isotope abundance distributions in liquids, solids, and particulate samples. The invention utilizes a collinear probe beam to interrogate a laser ablated plume. This invention provides enhanced single-shot detection sensitivity approaching the femtogram range, and isotope ratios that can be determined at approximately 1% or better precision and accuracy (relative standard deviation).

Bushaw, Bruce A; Anheier, Norman C; Phillips, Jon R

2013-07-02T23:59:59.000Z

323

Neutrino Masses in Flipped SU(5)  

E-Print Network [OSTI]

We analyse the fermion masses and mixings in the flipped SU(5) model. The fermion mass matrices are evolved from the GUT scale down to $m_W$ by solving the renormalization group equations for the Yukawa couplings. The constraints imposed by the charged fermion data are then utilised to make predictions about the neutrino properties . It is found that the {\\it generalized } see-saw mechanism which occurs naturally in this model can provide {\\it i})a solution to the solar neutrino problem via the MSW mechanism and {\\it ii})a sufficiently large $\

Leontaris, George K

1993-01-01T23:59:59.000Z

324

A Strontium Isotopic Study Of Newberry Volcano, Central Oregon...  

Open Energy Info (EERE)

Strontium Isotopic Study Of Newberry Volcano, Central Oregon- Structural And Thermal Implications Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal...

325

Isotopic Analysis- Fluid At Long Valley Caldera Geothermal Area...  

Open Energy Info (EERE)

Farrar, Et Al., 2003) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis- Fluid At Long Valley Caldera Geothermal Area (Farrar, Et...

326

Isotope and Temperature Effects in Liquid Water Probed by Soft...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

of temperature and isotope substitution (replacing the hydrogen with deuterium to make "heavy" water). Their findings shed new light on the unique microscopic and macroscopic...

327

Chemical And Isotopic Investigation Of Warm Springs Associated...  

Open Energy Info (EERE)

water (high TDS, > 5000 mgl). Deviations from the meteoric water line are the result of rock-water isotopic exchange, mixing or evaporation. Fluid source regions and residence...

328

Lead and strontium isotopic evidence for crustal interaction...  

Open Energy Info (EERE)

and strontium isotopic evidence for crustal interaction and compositional zonation in the source regions of Pleistocene basaltic and rhyolitic magmas of the Coso volcanic field,...

329

Geochemistry and Isotopes of Fluids from Sulphur Springs, Valles...  

Open Energy Info (EERE)

and Isotopes of Fluids from Sulphur Springs, Valles Caldera, New Mexico Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Geochemistry and...

330

Isotopic Analysis- Fluid At Valles Caldera - Sulphur Springs...  

Open Energy Info (EERE)

Jamie N. Gardner, Rosemary Vidale, Robert Charles (1985) Geochemistry and Isotopes of Fluids from Sulphur Springs, Valles Caldera, New Mexico Additional References Retrieved from...

331

Isotopic Analysis- Fluid At Roosevelt Hot Springs Geothermal...  

Open Energy Info (EERE)

of the Roosevelt Hot Springs Geothermal Area. Notes Stable isotope analysis of thermal fluids determined meteoric origin primarily from the Mineral Mountains with a small...

332

Regional And Local Trends In Helium Isotopes, Basin And Range...  

Open Energy Info (EERE)

Range Province, Western North America- Evidence For Deep Permeable Pathways Abstract Fluids from the western margin of the Basin and Range have helium isotope ratios as high as...

333

A Helium Isotope Perspective On The Dixie Valley, Nevada, Hydrothermal...  

Open Energy Info (EERE)

A Helium Isotope Perspective On The Dixie Valley, Nevada, Hydrothermal System Abstract Fluids from springs, fumaroles, and wells throughout Dixie Valley, NV were analyzed for noble...

334

Isotopic Analysis- Rock At Kilauea East Rift Geothermal Area...  

Open Energy Info (EERE)

Technique Isotopic Analysis- Rock Activity Date 1989 - 2000 Usefulness not indicated DOE-funding Unknown Exploration Basis The purpose of this study was to analyze deep core...

335

Isotopic Analysis- Fluid At Kilauea East Rift Geothermal Area...  

Open Energy Info (EERE)

navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis- Fluid At Kilauea East Rift Geothermal Area (Scholl, Et Al., 1993) Exploration...

336

Isotopic Analysis- Fluid At Indian Valley Hot Springs Geothermal...  

Open Energy Info (EERE)

Activity: Isotopic Analysis- Fluid At Indian Valley Hot Springs Geothermal Area (1990) Exploration Activity Details Location Indian Valley Hot Springs Geothermal Area...

337

Isotopic Analysis At Walker-Lane Transitional Zone Region (Kennedy...  

Open Energy Info (EERE)

Zone Region (Kennedy & Van Soest, 2007) Exploration Activity Details Location Walker-Lane Transition Zone Geothermal Region Exploration Technique Isotopic Analysis- Fluid Activity...

338

Isotopic Analysis At Valles Caldera - Redondo Geothermal Area...  

Open Energy Info (EERE)

White, Et Al., 1992) Exploration Activity Details Location Valles Caldera - Redondo Geothermal Area Exploration Technique Isotopic Analysis- Fluid Activity Date - 1992 Usefulness...

339

Isotopic Analysis- Fluid At Valles Caldera - Sulphur Springs...  

Open Energy Info (EERE)

Activity: Isotopic Analysis- Fluid At Valles Caldera - Sulphur Springs Geothermal Area (White, Et Al., 1992) Exploration Activity Details Location Valles Caldera - Sulphur Springs...

340

Isotopic Analysis At Valles Caldera - Redondo Geothermal Area...  

Open Energy Info (EERE)

White, 1986) Exploration Activity Details Location Valles Caldera - Redondo Geothermal Area Exploration Technique Isotopic Analysis- Fluid Activity Date - 1986 Usefulness not...

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Integrated Approach to Use Natural Chemical and Isotopic Tracers...  

Broader source: Energy.gov (indexed) [DOE]

Integrated Approach to Use Natural Chemical and Isotopic Tracers to Estimate Fracture Spacing and Surface Area in EGS Systems Integrated Approach to Use Natural Chemical and...

342

Integrated Approach to Use Natural Chemical and Isotopic Tracers...  

Broader source: Energy.gov (indexed) [DOE]

Approach to Use Natural Chemical and Isotopic Tracers to Estimate Fracture Spacing and Surface Area in EGS Systems B. Mack Kennedy (Presenter) and H. H. Liu Lawrence Berkeley...

343

Hydrogeological And Isotopic Survey Of Geothermal Fields In The...  

Open Energy Info (EERE)

Hydrogeological And Isotopic Survey Of Geothermal Fields In The Buyuk Menderes Graben, Turkey Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article:...

344

Workshop on The Nation's Needs for Isotopes: Present and Future...  

Office of Science (SC) Website

Workshop on The Nation's Needs for Isotopes: Present and Future Nuclear Physics (NP) NP Home About Research Facilities Science Highlights Benefits of NP Funding Opportunities...

345

Oxygen And Carbon Isotope Ratios Of Hydrothermal Minerals From...  

Open Energy Info (EERE)

boiling or by isotopic exchange at low waterrock ratios in new fractures. The mineralogy and apparent 18O enrichments of hydrothermal fracture-filling minerals are...

346

Descriptions of selected accidents that have occurred at nuclear reactor facilities  

SciTech Connect (OSTI)

This report was prepared at the request of the President's Commission on the Accident at Three Mile Island to provide the members of the Commission with some insight into the nature and significance of accidents that have occurred at nuclear reactor facilities in the past. Toward that end, this report presents a brief description of 44 accidents which have occurred throughout the world and which meet at least one of the severity criteria that were established.

Bertini, H.W.

1980-04-01T23:59:59.000Z

347

Naturally-Occurring Radionuclides In Drinking Water From Surface And Groundwater Reservoirs  

SciTech Connect (OSTI)

Radioactivity in water for human consumption is under closer scrutiny than ever before and many countries adopted guideline values based on total alpha and total beta activity measurements. Although most waters from surface circulation meet these guidelines, it is frequently found that groundwater exceed guideline values. Results of water analyses by alpha spectrometry clarified that the main radionuclides present are from the uranium decay series, such as uranium isotopes, radium ({sup 226}Ra), radon ({sup 222}Rn), and also {sup 210}Pb and {sup 210}Po. Occasionally, groundwater displayed {sup 226}Ra concentrations higher than 1 Bq L{sup -1} and {sup 222}Rn concentrations above 1000 Bq L{sup -1}. Nevertheless, lack of conformity of these waters with guidelines adopted, generally, is not due to anthropogenic inputs.

Carvalho, F. P.; Madruga, M. J.; Oliveira, J. M.; Lopes, I.; Ferrador, G.; Sequeira, M. M. [Nuclear and Technological Institute (ITN) Department of Radiological Protection and Nuclear Safety E.N. 10, 2686-953 Sacavem (Portugal)

2008-08-07T23:59:59.000Z

348

Validation of a Monte Carlo based depletion methodology via High Flux Isotope Reactor HEU post-irradiation examination measurements  

SciTech Connect (OSTI)

The purpose of this study is to validate a Monte Carlo based depletion methodology by comparing calculated post-irradiation uranium isotopic compositions in the fuel elements of the High Flux Isotope Reactor (HFIR) core to values measured using uranium mass-spectrographic analysis. Three fuel plates were analyzed: two from the outer fuel element (OFE) and one from the inner fuel element (IFE). Fuel plates O-111-8, O-350-1, and I-417-24 from outer fuel elements 5-O and 21-O and inner fuel element 49-I, respectively, were selected for examination. Fuel elements 5-O, 21-O, and 49-1 were loaded into HFIR during cycles 4, 16, and 35, respectively (mid to late 1960s). Approximately one year after each of these elements were irradiated, they were transferred to the High Radiation Level Examination Laboratory (HRLEL) where samples from these fuel plates were sectioned and examined via uranium mass-spectrographic analysis. The isotopic composition of each of the samples was used to determine the atomic percent of the uranium isotopes. A Monte Carlo based depletion computer program, ALEPH, which couples the MCNP and ORIGEN codes, was utilized to calculate the nuclide inventory at the end-of-cycle (EOC). A current ALEPH/MCNP input for HFIR fuel cycle 400 was modified to replicate cycles 4, 16, and 35. The control element withdrawal curves and flux trap loadings were revised, as well as the radial zone boundaries and nuclide concentrations in the MCNP model. The calculated EOC uranium isotopic compositions for the analyzed plates were found to be in good agreement with measurements, which reveals that ALEPH/MCNP can accurately calculate burn-up dependent uranium isotopic concentrations for the HFIR core. The spatial power distribution in HFIR changes significantly as irradiation time increases due to control element movement. Accurate calculation of the end-of-life uranium isotopic inventory is a good indicator that the power distribution variation as a function of space and time is accurately calculated, i.e. an integral check. Hence, the time dependent heat generation source terms needed for reactor core thermal hydraulic analysis, if derived from this methodology, have been shown to be accurate for highly enriched uranium (HEU) fuel.

Chandler, David [ORNL; Maldonado, G Ivan [ORNL; Primm, Trent [ORNL

2010-01-01T23:59:59.000Z

349

Top quark mass measurements  

SciTech Connect (OSTI)

The top quark, with its extraordinarily large mass (nearly that of a gold atom), plays a significant role in the phenomenology of EWSB in the Standard Model. In particular, the top quark mass when combined with the W mass constrains the mass of the as yet unobserved Higgs boson. Thus, a precise determination of the mass of the top quark is a principal goal of the CDF and D0 experiments. With the data collected thus far in Runs 1 and 2 of the Tevatron, CDF and D0 have measured the top quark mass in both the lepton+jets and dilepton decay channels using a variety of complementary experimental techniques. The author presents an overview of the most recent of the measurements.

Hill, Christopher S.; /UC, Santa Barbara

2004-12-01T23:59:59.000Z

350

Comparison of atmospheric hydrology over convective continental regions using water vapor isotope measurements from space  

E-Print Network [OSTI]

. Correlation analysis shows that mixing with boundary layer air, enhanced isotopic fractionation during precipitation, and subsiding air parcels contribute to intraseasonal isotopic variability. These local controls distillation in a Lagrangrian framework underestimates the observed isotopic depletion during the monsoons

351

GEOCHEMISTRY AND ISOTOPE HYDROLOGY OF GROUNDWATERS IN THE STRIPA GRANITE RESULTS AND PRELIMINARY INTERPRETATION  

E-Print Network [OSTI]

S. Italy). In Isotope Hydrology, IAEA Symposium. Sm-129/53,isotopic variations in hydrology. At. Energy Rev. 14: 621-70 GEOCHEMISTRY AND ISOTOPE HYDROLOGY OF GROUNDWATERS IN THE

Fritz, P.

2011-01-01T23:59:59.000Z

352

Isotope Specific Remediation Media and Systems - 13614  

SciTech Connect (OSTI)

On March 11, 2011, now two years ago, the magnitude 9.0 Great East Japan earthquake, Tohoku, hit off the Fukushima coast of Japan. While, of course, most of the outcome of this unprecedented natural and manmade disaster was a negative, both in Japan and worldwide, there have been some extremely invaluable lessons learned and new emergency recovery technologies and systems developed. As always, the mother of invention is necessity. Among these developments has been the development and full-scale implementation of proven isotope specific media (ISMs) with the intent of surgically removing specific hazardous isotopes for the purpose of minimizing dose to workers and the environment. The first such ISMs to be deployed at the Fukushima site were those removing cesium (Cs-137) and iodine (I-129). Since deployment on June 17, 2011, along with treated cooling water recycle, some 70% of the curies in the building liquid wastes have been removed by the Kurion system alone. The current levels of cesium are now only 2% of the original levels. Such an unprecedented, 'external cooling system' not only allowed the eventual cold shut down of the reactors in mid-December, 2011, but has allowed workers to concentrate on the cleanup of other areas of the site. Water treatment will continue for quite some time due to continued leakage into the buildings and the eventual goal of cleaning up the reactors and fuel pools themselves. With the cesium removal now in routine operation, other isotopes of concern are likely to become priorities. One such isotope is that of strontium, and yttrium (Sr-90 and Y-90), which is still at original levels causing further dose issues as well as impediments to discharge of the treated waste waters. For over a year now, a new synthetic strontium specific media has been under development and testing both in our licensed facility in Oak Ridge, Tennessee, but also in confirmatory tests by the Japan Atomic Energy Agency (JAEA) in Japan for Tokyo Electric Power Company (TEPCO). The tests have proven quite successful, even in high salt conditions, and, with loading and dose calculations being completed, will be proposed to add to the existing cesium system. There is no doubt, as high gamma isotopes are removed, other recalcitrant isotopes such as this will require innovative removal media, systems and techniques. Also coming out of this international effort are other ISM media and systems that can be applied more broadly to both Commercial Nuclear Power Plants (NPPs) as well as in Department of Energy (DOE) applications. This cesium and strontium specific media has further been successfully tested in 2012 at a Magnox station in the UK. The resulting proposed mitigation systems for pond and vault cleanup look quite promising. An extremely unusual ISM for carbon 14 (C-14), nickel (Ni-63) and cesium (Cs-137) has been developed for Diablo Canyon NPP for dose reduction testing in their fuel pool. These media will be deployed in Submersible Media Filter (SMF) and Submersible Columns (SC) systems adapted to standard Tri-Nuclear{sup R} housings common in the U.S. and UK. External Vessel Systems (mini-Fukushima) have also been developed as a second mitigation system for D and D and outages. Finally, technetium (Tc- 99) specific media developed for the Waste Treatment Plant (WTP) recycle or condensate (secondary) waste streams (WM 2011) are being further perfected and tested for At-Tank Tc-99 removal, as well as At Tank Cs media. In addition to the on-going media development, systems for deploying such media have developed over the last year and are in laboratory- and full-scale testing. These systems include the fore mentioned Submersible Media Filters (SMF), Submersible Columns (SC) and external pilot- and full-scale, lead-lag, canister systems. This paper will include the media development and testing, as well as that of the deployment systems themselves. (authors)

Denton, Mark S.; Mertz, Joshua L. [Kurion, Inc. Oak Ridge, Tennessee 37831 (United States)] [Kurion, Inc. Oak Ridge, Tennessee 37831 (United States); Morita, Keisuke [Japan Atomic Energy Agency, Tokai Research and Development Center, Fukushima Project Team, Tokai-mura, Ibaraki-ken, 319-1195 (Japan)] [Japan Atomic Energy Agency, Tokai Research and Development Center, Fukushima Project Team, Tokai-mura, Ibaraki-ken, 319-1195 (Japan)

2013-07-01T23:59:59.000Z

353

Ammonium transport and reaction in contaminated groundwater: Application of isotope tracers and isotope fractionation studies  

E-Print Network [OSTI]

Ammonium transport and reaction in contaminated groundwater: Application of isotope tracers the groundwater velocity. Retardation factors and groundwater ages indicate that much of the NH4 + in the plume was recharged early in the history of the wastewater disposal. NO3 Ã? and excess N2 gas, which were related

354

Nuclear Masses in Astrophysics  

E-Print Network [OSTI]

Among all nuclear ground-state properties, atomic masses are highly specific for each particular combination of N and Z and the data obtained apply to a variety of physics topics. One of the most crucial questions to be addressed in mass spectrometry of unstable radionuclides is the one of understanding the processes of element formation in the Universe. To this end, accurate atomic mass values of a large number of exotic nuclei participating in nucleosynthesis are among the key input data in large-scale reaction network calculations. In this paper, a review on the latest achievements in mass spectrometry for nuclear astrophysics is given.

Christine Weber; Klaus Blaum; Hendrik Schatz

2008-12-09T23:59:59.000Z

355

EMSL - Mass Spectrometer  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

MS) with high mass resolution (m&61636;m100,000). Solvent mixtures of acetonitrilewater and acetonitriletoluene were used to extract and ionize polar and non-polar...

356

Isomer residual ratio of odd-odd isotope {sup 180}Ta in supernova nucleosynthsis  

SciTech Connect (OSTI)

The nucleosynthesis of {sup 180}Ta has remained an unsolved problem and as its origin many nucleosynthesis mechanisms have been proposed. This isotope has the unique feature that the naturally occurring abundance of {sup 180}Ta is actually a meta-stable isomer (half-life of >=10{sup 15} yr), while the ground state is a 1{sup +} unstable state which beta-decays with a half-life of only 8.15 hr. We have made a new time-dependent calculation of {sup 180}Ta meta-stable isomer residual ratio after supernova neutrino-induced reactions. This residual isomer ratio is crucial for understanding the production and survival of this naturally occurring rare isotope. We have constructed a new model under temperature evolution after type II supernova explosion. We include the explicit linking between the isomer and all known excited states and found that the residual ratio is insensitive to astrophysical parameters such as neutrino energy spectrum, explosion energy, decay time constant. We find that the explicit time evolution of the synthesis of {sup 180}Ta avoids the overproduction relative to {sup 138}La for a neutrino process neutrino temperature of 4 MeV.

Hayakawa, Takehito [Japan Atomic Energy Agency, Kizugawa, Kyoto 619-0215 (Japan); Kajino, Toshitaka [National Astronomical Observatory, Osawa, Mitaka, Tokyo 181-8588 (Japan); Chiba, Satoshi [Japan Atomic Energy Agency, Tokai, Naka, Ibaraki 319-11 (Japan); Mathews, Grant [Enter for Astrophysics, Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States)

2010-06-01T23:59:59.000Z

357

Stable Isotopes (O, H, and S) in the Muteh Gold Deposit, Golpaygan Area, Iran  

SciTech Connect (OSTI)

The Muteh gold district with nine gold deposits is located in the Sanandaj-Sirjan metamorphic zone. Gold mineralization occurs in a pre-Permian complex which mainly consists of green schists, meta-volcanics, and gneiss rocks. Shear zones are the host of gold mineralization. Gold paragenesis minerals include pyrite, chalcopyrite, pyrrhotite, and secondary minerals. Pyrites occur as pre-, syn-, and post-metamorphism minerals. To determine the source of the ore-bearing fluids, fifty samples were selected for petrographical and stable isotope studies. The mean values of 12.4 per mille , and -42 per mille for {delta}{sup 18}O and {delta}D isotopes, respectively, and a mean value of 7.75 per mille of calculated fractionation factors for {delta}{sup 18}O H{sub 2}O, from quartz veins indicate that metamorphic host rocks are the most important source for the fluids and gold mineralization. Three generations of pyrite can be distinguished showing a wide range of {delta}{sup 34}S. Gold mineralization is closely associated with intense hydrothermal alteration along the ductile shear zones. The characteristics of the gold mineralization in the study area are similar to those of orogenic gold deposits elsewhere.

Abdollahi, M. J. [Shahid Bahonar University, Department of Geology (Iran, Islamic Republic of)], E-mail: kmgbkh@gmail.com; Karimpour, M. H. [Ferdousi University, Department of Geology (Iran, Islamic Republic of); Kheradmand, A. [Shahid Bahonar University, Department of Geology (Iran, Islamic Republic of); Zarasvandi, A. R. [Shahid Chamran University, Department of Geology (Iran, Islamic Republic of)

2009-06-15T23:59:59.000Z

358

Laser-assisted isotope separation of tritium  

DOE Patents [OSTI]

Methods for laser-assisted isotope separation of tritium, using infrared multiple photon dissociation of tritium-bearing products in the gas phase. One such process involves the steps of (1) catalytic exchange of a deuterium-bearing molecule XYD with tritiated water DTO from sources such as a heavy water fission reactor, to produce the tritium-bearing working molecules XYT and (2) photoselective dissociation of XYT to form a tritium-rich product. By an analogous procedure, tritium is separated from tritium-bearing materials that contain predominately hydrogen such as a light water coolant from fission or fusion reactors.

Herman, Irving P. (Castro Valley, CA); Marling, Jack B. (Livermore, CA)

1983-01-01T23:59:59.000Z

359

Comparison of isotopic transmutation modelling codes  

E-Print Network [OSTI]

. STAMATELATOS, "Fission Product Data for Thermal Reactors Part 2: Users Manual for EPRI-CINDER Code and Data, " LA-6746-MS, Los Alamos National Laboratory (Dec. 1976). 5. H. BATEMAN, ~RGE~di gH gf ~t gym~id 6. M. J. BEIL, "ORIGEN ? The ORNL Isotope... Generation and Depletion Code, " ORNL-4628, Oak Ridge National Laboratory (May, 1973). 7. O. W. HERMANN and R. M. WESTFALL, "ORIGEN-S Scale System Module to Calculate Fuel Depletion, Actinide Transmutation, Fission Product. Buildup and Decay...

Beard, Carl Allen

1990-01-01T23:59:59.000Z

360

Nuclear Data Evaluations for Americium Isotopes  

SciTech Connect (OSTI)

Recent upgrades of 241Am, 242mAm, and 240Am nuclear data in the keV - 30-MeV range are described. The new evaluation takes advantage of recent measurements and advances in calculational modeling methods. The model calculations are especially important for the nuclear data of americium isotopes, because few measurements are available. The nuclear-model code GNASH is extensively used for our evaluations. The new evaluations are given for total, fission, capture (n, 2n), and (n, 3n) reaction cross sections, and vp for 241Am and 242mAm. A new evaluation for 240Am is also given by expanding our modeling feasibility.

Kawano, T.; Talou, P.; Chadwick, M.B.; MacFarlane, R.E.; Young, P.G. [T-16 Nuclear Physics, Los Alamos National Laboratory (United States)

2005-05-24T23:59:59.000Z

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Apparatus for isotopic alteration of mercury vapor  

DOE Patents [OSTI]

An apparatus for enriching the isotopic Hg content of mercury is provided. The apparatus includes a reactor, a low pressure electric discharge lamp containing a fill including mercury and an inert gas. A filter is arranged concentrically around the lamp. In a preferred embodiment, constant mercury pressure is maintained in the filter by means of a water-cooled tube that depends from it, the tube having a drop of mercury disposed in it. The reactor is arranged around the filter, whereby radiation from said lamp passes through the filter and into said reactor. The lamp, the filter and the reactor are formed of a material which is transparent to ultraviolet light.

Grossman, Mark W. (Belmont, MA); George, William A. (Gloucester, MA); Marcucci, Rudolph V. (Danvers, MA)

1988-01-01T23:59:59.000Z

362

A nuclear physics program at the Rare Isotope Beams Accelerator Facility in Korea  

SciTech Connect (OSTI)

This paper outlines the new physics possibilities that fall within the field of nuclear structure and astrophysics based on experiments with radioactive ion beams at the future Rare Isotope Beams Accelerator facility in Korea. This ambitious multi-beam facility has both an Isotope Separation On Line (ISOL) and fragmentation capability to produce rare isotopes beams (RIBs) and will be capable of producing and accelerating beams of wide range mass of nuclides with energies of a few to hundreds MeV per nucleon. The large dynamic range of reaccelerated RIBs will allow the optimization in each nuclear reaction case with respect to cross section and channel opening. The low energy RIBs around Coulomb barrier offer nuclear reactions such as elastic resonance scatterings, one or two particle transfers, Coulomb multiple-excitations, fusion-evaporations, and direct capture reactions for the study of the very neutron-rich and proton-rich nuclides. In contrast, the high energy RIBs produced by in-flight fragmentation with reaccelerated ions from the ISOL enable to explore the study of neutron drip lines in intermediate mass regions. The proposed studies aim at investigating the exotic nuclei near and beyond the nucleon drip lines, and to explore how nuclear many-body systems change in such extreme regions by addressing the following topics: the evolution of shell structure in areas of extreme proton to neutron imbalance; the study of the weak interaction in exotic decay schemes such as beta-delayed two-neutron or two-proton emission; the change of isospin symmetry in isobaric mirror nuclei at the drip lines; two protons or two neutrons radioactivity beyond the drip lines; the role of the continuum states including resonant states above the particle-decay threshold in exotic nuclei; and the effects of nuclear reaction rates triggered by the unbound proton-rich nuclei on nuclear astrophysical processes.

Moon, Chang-Bum, E-mail: cbmoon@hoseo.edu [Hoseo University, Asan, Chung-Nam 336-795 (Korea, Republic of)] [Hoseo University, Asan, Chung-Nam 336-795 (Korea, Republic of)

2014-04-15T23:59:59.000Z

363

Design of small Stirling Dynamic Isotope Power System for robotic space missions  

SciTech Connect (OSTI)

Design of a multihundred-watt Dynamic Isotope Power System (DIPS) based on the U.S. Department of Energy (DOE) General Purpose Heat Source (GPHS) and small (multihundred-watt) free-piston Stirling engine (FPSE) technology is being pursued as a potential lower cost alternative to radioisotope thermoelectric generator (RTG's). The design is targeted at the power needs of future unmanned deep space and planetary surface exploration missions ranging from scientific probes to Space Exploration Initiative precursor missions. Power level for these missions is less than a kilowatt. Unlike previous DIPS designs which were based on turbomachinery conversion (e.g. Brayton), this small Stirling DIPS can be advantageously scaled down to multihundred-watt unit size while preserving size and mass competitiveness with RTGs. Preliminary characterization of units in the output power ranges 200--600 We indicate that on an electrical watt basis the GPHS/small Stirling DIPS will be roughly equivalent to an advanced RTG in size and mass but require less than a third of the isotope inventory.

Bents, D.J.; Schreiber, J.G.; Withrow, C.A.; McKissock, B.I. (National Aeronautics and Space Administration, Lewis Research Center, Cleveland, Ohio 44135 (United States)); Schmitz, P.C. (Sverdrup Technology, Inc., Lewis Research Center Group, Brook Park, Ohio 44142 (United States))

1993-01-10T23:59:59.000Z

364

E-Print Network 3.0 - actinide isotope content Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

by Linda Campbell) Summary: for describing a process that changes the content of the heavy isotope of some element in the substance being... Common Mistakes in Stable isotope...

365

E-Print Network 3.0 - africa sulfur isotope Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

By combining the isotopic com- position of the major... Isotopic Composition in Rainwater Chris ... Source: Niyogi, Dev - Department of Agronomy, Purdue University...

366

Magnesium isotopic fractionation in chondrules from the Murchison and Murray CM2 carbonaceous chondrites  

E-Print Network [OSTI]

Magnesium isotopic fractionation in chondrules from the Murchison and Murray CM2 carbonaceous. Investigation of the magnesium isotopic compositions of chondrules can place stringent constraints on the timing

Grossman, Lawrence

367

Facility for Rare Isotope Beams: The Journey Has Begun on DOE...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Facility for Rare Isotope Beams: The Journey Has Begun on DOE's latest Scientific User Facility Facility for Rare Isotope Beams: The Journey Has Begun on DOE's latest Scientific...

368

Radioisotopic Impurities in Promethium-147 Produced at the ORNL High Flux Isotope Reactor.  

E-Print Network [OSTI]

??There is an intense interest in the availability of radioactive isotopes that could be developed into nuclear batteries. Promethium-147 is one of the isotopes of… (more)

Hinderer, James Howard

2010-01-01T23:59:59.000Z

369

E-Print Network 3.0 - analysing pb isotopes Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Mobile Pb-isotopes in Proterozoic sedimentary basins as guides for exploration of uranium deposits... isotope ratios and associated trace element concentrations (U, Th and...

370

Calibration and application of the `clumped isotope' thermometer to foraminifera for high-resolution climate  

E-Print Network [OSTI]

Calibration and application of the `clumped isotope' thermometer to foraminifera for high proxies. Here, we present a new calibration of the `clumped isotope' thermometer to foraminifera based

Gilli, Adrian

371

MASS MEASUREMENT UNCERTAINTY FOR PLUTONIUM ALIQUOTS ASSAYED BY CONTROLLED-POTENTIAL COULOMETRY  

SciTech Connect (OSTI)

Minimizing plutonium measurement uncertainty is essential to nuclear material control and international safeguards. In 2005, the International Organization for Standardization (ISO) published ISO 12183 'Controlled-potential coulometric assay of plutonium', 2nd edition. ISO 12183:2005 recommends a target of {+-}0.01% for the mass of original sample in the aliquot because it is a critical assay variable. Mass measurements in radiological containment were evaluated and uncertainties estimated. The uncertainty estimate for the mass measurement also includes uncertainty in correcting for buoyancy effects from air acting as a fluid and from decreased pressure of heated air from the specific heat of the plutonium isotopes.

Holland, M.; Cordaro, J.

2009-03-18T23:59:59.000Z

372

RADIOGENIC ISOTOPES: TRACERS OF PAST OCEAN CIRCULATION AND EROSIONAL INPUT  

E-Print Network [OSTI]

in the ocean has varied as a function of changes in paleocircu- lation, source provenances, style and intensity-established paleoceano- graphic tracers such as carbon isotopes. INDEX TERMS: 1040 Geochemistry: Isotopic composition Atlantic Deep Water (NADW) according to latest estimates based on results of the World Ocean Circulation

Jellinek, Mark

373

Isotopic composition of stratospheric water vapor: Measurements and photochemistry  

E-Print Network [OSTI]

of magnitude between the surface and the tropopause, and isotopically heavy water is pref- erentially removedIsotopic composition of stratospheric water vapor: Measurements and photochemistry David G. Johnson composition of stratospheric water vapor that result from methane oxidation and reactions with O( ¢¡ ). We

374

Lithium Isotope History of Cenozoic Seawater: Changes in Silicate Weathering  

E-Print Network [OSTI]

Lithium Isotope History of Cenozoic Seawater: Changes in Silicate Weathering and Reverse Weathering 70 Ma · Overview of the Marine Lithium Cycle · Analytical Challenges · 68 Million Year Seawater Lithium Isotope Record (Forams) · Interpretation Standard: NIST L-SVEC Li (SRM 8545) #12;100 Ma Climate

Paytan, Adina

375

Constraining magnesium cycling in marine sediments using magnesium isotopes  

E-Print Network [OSTI]

Constraining magnesium cycling in marine sediments using magnesium isotopes J.A. Higgins *, D Abstract Magnesium concentrations in deep-sea sediment pore-fluids typically decrease down core due to net and differentiate these processes, we have measured magnesium isotopes in pore-fluids and sediment samples from

Paytan, Adina

376

Hydrochemical and isotopic effects associated with petroleum fuel biodegradation pathways  

E-Print Network [OSTI]

hydrocarbons and residual electron acceptors have been used to deduce BTEX and MTBE degradation pathways. Benzene and MTBE persist into the denitrification zone, with carbon isotope enrichment of benzene-enrichment of residual benzene gives an apparent e value of Ã?0.66x. MTBE shows no significant isotopic enrichment (d13 C

Sheffield, University of

377

mass communication advertising &  

E-Print Network [OSTI]

mass communication advertising & public relations introduction. Graduate programs in the Department of Mass Communication, Advertising, and Public Relations provide an entry to a wide spectrum of careers in the communication industry. Classes, internships, site visits, and presentations by top professionals offer students

Finzi, Adrien

378

Elbow mass flow meter  

DOE Patents [OSTI]

The present invention includes a combination of an elbow pressure drop generator and a shunt-type mass flow sensor for providing an output which gives the mass flow rate of a gas that is nearly independent of the density of the gas. For air, the output is also approximately independent of humidity. 3 figs.

McFarland, A.R.; Rodgers, J.C.; Ortiz, C.A.; Nelson, D.C.

1994-08-16T23:59:59.000Z

379

The Origins of Mass  

SciTech Connect (OSTI)

The Higgs boson was discovered in July of 2012 and is generally understood to be the origin of mass. While those statements are true, they are incomplete. It turns out that the Higgs boson is responsible for only about 2% of the mass of ordinary matter. In this dramatic new video, Dr. Don Lincoln of Fermilab tells us the rest of the story.

Lincoln, Don

2014-07-30T23:59:59.000Z

380

Gas Chromatography -Mass Spectrometry  

E-Print Network [OSTI]

GCMS - 1 Gas Chromatography - Mass Spectrometry GC-MS ANALYSIS OF ETHANOL AND BENZENE IN GASOLINE Last updated: June 17, 2014 #12;GCMS - 2 Gas Chromatography - Mass Spectrometry GC-MS ANALYSIS). The goal of this experiment is to separate the components in a sample of gasoline using Gas Chromatography

Nizkorodov, Sergey

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

The Origins of Mass  

ScienceCinema (OSTI)

The Higgs boson was discovered in July of 2012 and is generally understood to be the origin of mass. While those statements are true, they are incomplete. It turns out that the Higgs boson is responsible for only about 2% of the mass of ordinary matter. In this dramatic new video, Dr. Don Lincoln of Fermilab tells us the rest of the story.

Lincoln, Don

2014-08-07T23:59:59.000Z

382

Special Application Thermoelectric Micro Isotope Power Sources  

SciTech Connect (OSTI)

Promising design concepts for milliwatt (mW) size micro isotope power sources (MIPS) are being sought for use in various space and terrestrial applications, including a multitude of future NASA scientific missions and a range of military applications. To date, the radioisotope power sources (RPS) used on various space and terrestrial programs have provided power levels ranging from one-half to several hundred watts. In recent years, the increased use of smaller spacecraft and planned new scientific space missions by NASA, special terrestrial and military applications suggest the need for lower power, including mW level, radioisotope power sources. These power sources have the potential to enable such applications as long-lived meteorological or seismological stations distributed across planetary surfaces, surface probes, deep space micro-spacecraft and sub-satellites, terrestrial sensors, transmitters, and micro-electromechanical systems. The power requirements are in the range of 1 mW to several hundred mW. The primary technical requirements for space applications are long life, high reliability, high specific power, and high power density, and those for some special military uses are very high power density, specific power, reliability, low radiological induced degradation, and very low radiation leakage. Thermoelectric conversion is of particular interest because of its technological maturity and proven reliability. This paper summarizes the thermoelectric, thermal, and radioisotope heat source designs and presents the corresponding performance for a number of mW size thermoelectric micro isotope power sources.

Heshmatpour, Ben; Lieberman, Al; Khayat, Mo; Leanna, Andrew; Dobry, Ted [Teledyne Energy Systems, Incorporated, 10707 Gilroy Road, Hunt Valley, MD 21031 (United States)

2008-01-21T23:59:59.000Z

383

Global Security, Medical Isotopes, and Nuclear Science  

SciTech Connect (OSTI)

Over the past century basic nuclear science research has led to the use of radioactive isotopes into a wide variety of applications that touch our lives everyday. Some are obvious, such as isotopes for medical diagnostics and treatment. Others are less so, such as National/Global security issues. And some we take for granted, like the small amount of 241Am that is in every smoke detector. At the beginning of this century, we are in a position where the prevalence and importance of some applications of nuclear science are pushing the basic nuclear science community for improved models and nuclear data. Yet, at the same time, the push by the basic nuclear science community to study nuclei that are farther and farther away from stability also offer new opportunities for many applications. This talk will look at several global security applications of nuclear science, summarizing current R&D and need for improved nuclear data It will also look at how applications of nuclear science, such as to medicine, will benefit from the push for more and more powerful radioactive ion beam facilities.

Ahle, L E

2007-09-17T23:59:59.000Z

384

Electron generation of leptons and hadrons with reciprocal -quantized lifetimes and masses  

E-Print Network [OSTI]

1 Electron generation of leptons and hadrons with reciprocal -quantized lifetimes and masses generation occurs via an initial "-leap" from an electron pair to a "platform state" M, and then subsequent in the generation of hadron masses. In fact, the role of the electron in generating lepton masses has never been

385

Isotopic mass-dependence of noble gas diffusion coefficients in water  

E-Print Network [OSTI]

extended simple point charge (SPC/E) model of Berendsen ete and q H = 0.4238 e)] the SPC/E model predicts the self-Hura et al. , 2003). On the SPC/E model, short-range non-

Bourg, I.C.; Sposito, G.

2008-01-01T23:59:59.000Z

386

A Mass Spectrometry Study of Isotope Separation in the Laser Plume  

E-Print Network [OSTI]

1.4.2 Atomic Absorption5.3.2 Atomic Absorption Spectrometry . . . . . . . . . . .ablation and diode laser-atomic absorption spectrometry”,

Suen, Timothy Wu

2012-01-01T23:59:59.000Z

387

A Mass Spectrometry Study of Isotope Separation in the Laser Plume  

E-Print Network [OSTI]

Gamma Ray Spectrometry . . . . . . . . . . . . . . . . . . .29, 30] Gamma Ray Spectrometry Gamma ray spectrometry willare measured by gamma spectrometry and compared to model

Suen, Timothy Wu

2012-01-01T23:59:59.000Z

388

Lead Isotopic Variations of the Pacific and Implications for Paleogene Water Mass Composition  

E-Print Network [OSTI]

sincerest thanks to my advisor and committee chair, Dr. Debbie Thomas, who has never failed to provide expert guidance and valuable advice. I would also thank my committee members, Drs. Franco Marcantonio and Robert Korty, as well as Dr. Brent Miller...;#19;Ý #28;#19;Ý #28;#19;Ý CJ01 CLD01 CB12 Marshalls Nova Tasman MP3D07 MDD53 CXD55 192 323 463 464 596 883 192 883 64 463 596 323 18.7-19.5 15.53-15.68 38.2- 39.2 17.9-19.4 15.52-15.68 38.3-39.1 17.9-18.7 15.4-15.7 37.7-38.9 19.5-21 15.6-15.75 38...

Subt, Cristina

2013-11-13T23:59:59.000Z

389

A Mass Spectrometry Study of Isotope Separation in the Laser Plume  

E-Print Network [OSTI]

Enriched Uranium Particles”, Analytical Chemistry 71, 2616 (Uranium Oxide Microparticles: A Nuclear Forensic Diagnostic”, Analytical Chemistry

Suen, Timothy Wu

2012-01-01T23:59:59.000Z

390

A Mass Spectrometry Study of Isotope Separation in the Laser Plume  

E-Print Network [OSTI]

quantities of natural or depleted uranium [8]. Plutonium, on235 U abundance in depleted uranium. The sample was ablatedsuch as 235 U in depleted uranium [64] or short-lived

Suen, Timothy Wu

2012-01-01T23:59:59.000Z

391

Fission Yield Measurements by Inductively Coupled Plasma Mass-Spectrometry  

SciTech Connect (OSTI)

Correct prediction of the fission products inventory in irradiated nuclear fuels is essential for accurate estimation of fuel burnup, establishing proper requirements for spent fuel transportation and storage, materials accountability and nuclear forensics. Such prediction is impossible without accurate knowledge of neutron induced fission yields. Unfortunately, the accuracy of the fission yields reported in the ENDF/B-VII.0 library is not uniform across all of the data and much of the improvement is desired for certain isotopes and fission products. We discuss our measurements of cumulative fission yields in nuclear fuels irradiated in thermal and fast reactor spectra using Inductively Coupled Plasma Mass Spectrometry.

Irina Glagolenko; Bruce Hilton; Jeffrey Giglio; Daniel Cummings; Karl Grimm; Richard McKnight

2009-11-01T23:59:59.000Z

392

Isospin effects on the mass dependence of balance energy  

E-Print Network [OSTI]

We study the effect of isospin degree of freedom on balance energy throughout the mass range between 50 and 350 for two sets of isotopic systems with N/Z = 1.16 and 1.33 as well as isobaric systems with N/Z = 1.0 and 1.4. Our findings indicate that different values of balance energy for two isobaric systems may be mainly due to the Coulomb repulsion. We also demonstrate clearly the dominance of Coulomb repulsion over symmetry energy.

Sakshi Gautam; Aman D. Sood

2010-07-09T23:59:59.000Z

393

Isospin effects on the mass dependence of the balance energy  

SciTech Connect (OSTI)

We study the effect of isospin degree of freedom on balance energy throughout the mass range between 50 and 350 for two sets of isotopic systems with N/A= 0.54 and 0.57 as well as isobaric systems with N/A= 0.5 and 0.58. Our findings indicate that different values of balance energy for two isobaric systems may be mainly due to the Coulomb repulsion. We also demonstrate clearly the dominance of Coulomb repulsion over symmetry energy.

Gautam, Sakshi [Department of Physics, Panjab University, Chandigarh 160 014 (India); Sood, Aman D. [SUBATECH, Laboratoire de Physique Subatomique et des Technologies Associees, Universite de Nantes, IN2P3/CNRS, EMN 4 rue Alfred Kastler, F-44072 Nantes (France)

2010-07-15T23:59:59.000Z

394

A METHODOLOGY FOR DETERMINING THE DOSE RATE FOR BOUNDING MASS LIMITS IN A 9977 PACKAGING  

SciTech Connect (OSTI)

The Small Gram Quantity (SGQ) concept is based on the understanding that the hazards associated with the shipment of a radioactive material are directly proportional to its mass. This study describes a methodology that estimates the acceptable masses for several neutron and gamma emitting isotopes that can be shipped in a 9977 Package compliant with the Title 10 of the Code of Federal Regulations, Part 71 (10CFR71) external radiation level limits. 10CFR71.33 states that a shipping application identifies the radioactive and fissile materials at their maximum quantity and provides an evaluation demonstrating compliance with the external radiation standards. Since rather small amounts of some isotopes emit sufficiently strong radiation to produce a large external dose rate, quantifying of the dose rate for a proposed content is a challenging issue for the SGQ approach. It is essential to quantify external radiation levels from several common gamma and neutron sources that can be safely placed in a specific packaging, to ensure compliance with federal regulations. A methodology was established for determining the dose rate for bounding mass limits for a set of isotopes in the Model 9977 Shipping Package. Calculations were performed to estimate external radiation levels using the MCNP radiation transport code to develop a set of response multipliers (Green's functions) for 'dose per source particle' for each neutron and photon spectral group. The source spectrum from one gram of each isotope was folded with the response multipliers to generate the dose rate per gram of each isotope in the 9977 shipping package and its associated shielded containers. The maximum amount of a single isotope that could be shipped within the regulatory limits for dose rate at the surface was determined. For a package containing a mixture of isotopes, the acceptability for shipment can be determined by a sum of fractions approach. Furthermore, the results of this analysis can be easily extended to additional radioisotopes by simply evaluating the neutron and/or photon spectra of those isotopes and folding the spectral data with the Green's functions provided.

Abramczyk, G.; Bellamy, S.; Nathan, S.; Loftin, B.

2012-05-24T23:59:59.000Z

395

Tuesday, 31 July, 2012 Rapid radiation belt losses occurring during high speed solar wind stream1  

E-Print Network [OSTI]

Tuesday, 31 July, 2012 1 Rapid radiation belt losses occurring during high speed solar wind stream1 Raita11 Sodankylä Geophysical Observatory, University of Oulu, Sodankylä, Finland12 Abstract. Recent geomagnetic disturbances triggered by the arrival of a Solar14 Wind Stream Interface (SWSI). In the current

Otago, University of

396

2 Bainitic Ferrite The growth of pearlite occurs at a common transformation front with the  

E-Print Network [OSTI]

2 Bainitic Ferrite The growth of pearlite occurs at a common transformation front with the austenite. The growth of the ferrite and cementite phases is coupled and their compositions are complementary since the carbon which cannot be accommodated by the ferrite is incorporated into the cementite

Cambridge, University of

397

Endophytic and canker-associated Botryosphaeriaceae occurring on non-native Eucalyptus and native Myrtaceae  

E-Print Network [OSTI]

Endophytic and canker-associated Botryosphaeriaceae occurring on non-native Eucalyptus and native to identify the Botryosphaeriaceae species present as endophytes or associated with cankers in both introduced is a very diverse group of fungi that includes endophytes and plant pathogens of trees and plants (Alves et

398

Jet-like circulations occur in the `simple' geometries of gas planets and Earth's  

E-Print Network [OSTI]

#12;Jet-like circulations occur in the `simple' geometries of gas planets and Earth's liquid stratification and boundary topography are both essential elements in structuring energy-containing eddies-slope waveguide) in a model basin, here driven by a compact cooling region at high latitude (Hallberg & Rhines JPO

399

C6H5Br+ f C6H5 + + Br Occurs via Orbiting Transition State  

E-Print Network [OSTI]

-analyzed ion kinetic energy spectrometry. The rate constant and kinetic energy release distribution have been at high internal energy. The completely loose transition state model, namely the reaction occurring via compared with theoretical calculations. The rate-energy data available over 6 orders of magnitude in time

Kim, Myung Soo

400

The red porgy, Pagrus pagrus, occurs in the eastern Atlantic from the Brit-  

E-Print Network [OSTI]

723 The red porgy, Pagrus pagrus, occurs in the eastern Atlantic from the Brit- ish Isles south and Vergara, 1978). In the Gulf of Mexico (GOM), red porgy are usu- ally found near hard-bottom areas off that red porgies are most common over inshore live-bottom habitats and over shelf-edge, rocky-rub- ble

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

"Climate change is sure to occur in some form." The study of climate impacts notes  

E-Print Network [OSTI]

"Climate change is sure to occur in some form." 1 #12;The study of climate impacts notes how scientists generally agree that humans are changing the climate, and that if we continue pumping carbon we learn from past climate variations? How can we best adapt to climate change? This report attempts

402

Fuel-related accidents occur across the country at the rate of more than one per  

E-Print Network [OSTI]

Fuel-related accidents occur across the country at the rate of more than one per week. Fuel exhaustion, fuel starvation, or the failure to switch tanks at the correct time caused 120 accidents in 2002, these and other problems can be avoided with proper fueling procedures. RESPONSIBILITY STARTS WITH THE AIRPORT

Minnesota, University of

403

Figure 1. Bipartite network showing how candidate SNPs co-occur across Colombian  

E-Print Network [OSTI]

Figure 1. Bipartite network showing how candidate SNPs co-occur across Colombian patients with one Study of Chronic Metabolic Diseases in Colombians Maria A. Caro MSc1,2 , Bryant Dang BS1 , Gabriel, are associated with key demographic and clinical variables in Colombians with metabolic disease. The results

Bhavnani, Suresh K.

404

New species of Mycosphaerella occurring on Eucalyptus leaves in Indonesia and Africa  

E-Print Network [OSTI]

781 New species of Mycosphaerella occurring on Eucalyptus leaves in Indonesia and Africa P.W. Crous and M.J. Wingfield Ahstract:Although Africa and Indonesia have not been particularly well surveyed Eucalyptus leaves from Indonesia. The former species is of particular interest, because its anamorph

405

Spike-timing dependent plasticity Spike order determines if potentiation or depression occurs [Poo98].  

E-Print Network [OSTI]

in dendritic spines of pyramidal cells (L2/3, somatosensory cortex) does not predict the occurence of LTP or LTD. In this imaging experiment, the change relative to baseline of a Ca-sensitive green flourescent dye (DG) was normalized by a Ca-insensitive red flourescent dye (R) to account for differences

Boahen, Kwabena

406

Movement of oxygen from the atmosphere to the mitochondria occurs via several convective and diffusive steps  

E-Print Network [OSTI]

4111 Movement of oxygen from the atmosphere to the mitochondria occurs via several convective and diffusive steps (Weibel et al., 1981). In mammals, maximal rate of oxygen consumption (VOmax) is not limited by any one step of the oxygen cascade; rather limitations to VOmax are distributed across all steps

Bennett, Albert F.

407

Xylem cavitation caused by drought and freezing stress in four co-occurring Juniperus species  

E-Print Network [OSTI]

Xylem cavitation caused by drought and freezing stress in four co-occurring Juniperus species: 10.1111/j.1399-3054.2006.00644.x Previous studies indicate that conifers are vulnerable to cavitation cavitation, along with wood density, conduit reinforcement, trac- heid diameter, and hydraulic conductivity

Jackson, Robert B.

408

Cooker's sloshing experiment with baffles: a naturally occurring multifold 1: :1 resonance  

E-Print Network [OSTI]

Cooker's sloshing experiment with baffles: a naturally occurring multifold 1: · · · :1 resonance interest. The starting point is Cooker's experiment (COOKER 1994). It is an experiment in the spirit. In this case the question is the effect of vehicle coupling on fluid sloshing. In Cooker's experiment

Bridges, Tom

409

Disk Accretion Onto High-Mass Planets  

E-Print Network [OSTI]

We analyze the nonlinear, two-dimensional response of a gaseous, viscous protoplanetary disk to the presence of a planet of one Jupiter mass (1 M_J) and greater that orbits a 1 solar mass star by using the ZEUS hydrodynamics code with high resolution near the planet's Roche lobe. The planet is assumed to be in a circular orbit about the central star and is not allowed to migrate. A gap is formed about the orbit of the planet, but there is a nonaxisymmetric flow through the gap and onto the planet. The gap partitions the disk into an inner (outer) disk that extends inside (outside) the planet's orbit. For a 1 M_J planet and typical disk parameters, the accretion through the gap onto the planet is highly efficient. For typical disk parameters, the mass doubling time scale is less than 10^5 years, considerably shorter than the disk lifetime. Following shocks near the L1 and L2 Lagrange points, disk material enters the Roche lobe in the form of two gas streams. Shocks occur within the Roche lobe as the gas streams collide, and shocks lead to rapid inflow towards the planet within much of planet's Roche lobe. Shocks also propagate in the inner and outer disks that orbit the star. For higher mass planets (of order 6 M_J), the flow rate onto the planet is considerably reduced, which suggests an upper mass limit to planets in the range of 10 M_J. This rate reduction is related to the fact that the gap width increases relative to the Roche (Hill sphere) radius with increasing planetary mass. The flow in the gap affects planetary migration. For the 1 M_J planet case, mass can penetrate from the outer disk to the inner disk, so that the inner disk is not depleted. The results suggest that most of the mass in gas giant planets is acquired by flows through gaps.

S. H. Lubow; M. Seibert; P. Artymowicz

1999-10-21T23:59:59.000Z

410

Recent activities for ?-decay half-lives and ?-delayed neutron emission of very neutron-rich isotopes  

SciTech Connect (OSTI)

Beta-delayed neutron (?n) emitters play an important, two-fold role in the stellar nucleosynthesis of heavy elements in the 'rapid neutron-capture process' (r process). On one hand they lead to a detour of the material ?-decaying back to stability. On the other hand, the released neutrons increase the neutron-to-seed ratio, and are re-captured during the freeze-out phase and thus influence the final solar r-abundance curve. A large fraction of the isotopes inside the r-process reaction path are not yet experimentally accessible and are located in the (experimental) 'Terra Incognita'. With the next generation of fragmentation and ISOL facilities presently being built or already in operation, one of the main motivation of all projects is the investigation of these very neutron-rich isotopes. A short overview of one of the planned programs to measure ?n-emitters at the limits of the presently know isotopes, the BRIKEN campaign (Beta delayed neutron emission measurements at RIKEN) will be given. Presently, about 600 ?-delayed one-neutron emitters are accessible, but only for a third of them experimental data are available. Reaching more neutron-rich isotopes means also that multiple neutron-emission becomes the dominant decay mechanism. About 460 ?-delayed two-, three-or four-neutron emitters are identified up to now but for only 30 of them experimental data about the neutron branching ratios are available, most of them in the light mass region below A=30. The International Atomic and Energy Agency (IAEA) has identified the urgency and picked up this topic recently in a 'Coordinated Research Project' on a 'Reference Database for Beta-Delayed Neutron Emission Data'. This project will review, compile, and evaluate the existing data for neutron-branching ratios and half-lives of ?-delayed neutron emitters and help to ensure a reliable database for the future discoveries of new isotopes and help to constrain astrophysical and theoretical models.

Dillmann, Iris [TRIUMF, Vancouver BC, V6T 2A3, Canada and GSI Helmholtzzentrum für Schwerionenforschung GmbH, D-64291 Darmstadt (Germany); Abriola, Daniel [Laboratorio Tandar, Comisión Nacional de Energía Atómica, B1650KINA, San Martín, Buenos Aires (Argentina); Singh, Balraj [Department of Physics and Astronomy, McMaster University, Hamilton ON, L8S 4M1 (Canada)

2014-05-02T23:59:59.000Z

411

Isotope exchange kinetics in metal hydrides I : TPLUG model.  

SciTech Connect (OSTI)

A one-dimensional isobaric reactor model is used to simulate hydrogen isotope exchange processes taking place during flow through a powdered palladium bed. This simple model is designed to serve primarily as a platform for the initial development of detailed chemical mechanisms that can then be refined with the aid of more complex reactor descriptions. The one-dimensional model is based on the Sandia in-house code TPLUG, which solves a transient set of governing equations including an overall mass balance for the gas phase, material balances for all of the gas-phase and surface species, and an ideal gas equation of state. An energy equation can also be solved if thermodynamic properties for all of the species involved are known. The code is coupled with the Chemkin package to facilitate the incorporation of arbitrary multistep reaction mechanisms into the simulations. This capability is used here to test and optimize a basic mechanism describing the surface chemistry at or near the interface between the gas phase and a palladium particle. The mechanism includes reversible dissociative adsorptions of the three gas-phase species on the particle surface as well as atomic migrations between the surface and the bulk. The migration steps are more general than those used previously in that they do not require simultaneous movement of two atoms in opposite directions; this makes possible the creation and destruction of bulk vacancies and thus allows the model to account for variations in the bulk stoichiometry with isotopic composition. The optimization code APPSPACK is used to adjust the mass-action rate constants so as to achieve the best possible fit to a given set of experimental data, subject to a set of rigorous thermodynamic constraints. When data for nearly isothermal and isobaric deuterium-to-hydrogen (D {yields} H) and hydrogen-to-deuterium (H {yields} D) exchanges are fitted simultaneously, results for the former are excellent, while those for the latter show pronounced deviations at long times. These discrepancies can be overcome by postulating the presence of a surface poison such as carbon monoxide, but this explanation is highly speculative. When the method is applied to D {yields} H exchanges intentionally poisoned by known amounts of CO, the fitting results are noticeably degraded from those for the nominally CO-free system but are still tolerable. When TPLUG is used to simulate a blowdown-type experiment, which is characterized by large and rapid changes in both pressure and temperature, discrepancies are even more apparent. Thus, it can be concluded that the best use of TPLUG is not in simulating realistic exchange scenarios, but in extracting preliminary estimates for the kinetic parameters from experiments in which variations in temperature and pressure are intentionally minimized.

Larson, Rich; James, Scott Carlton; Nilson, Robert H.

2011-05-01T23:59:59.000Z

412

MASS POLITICAL MOBILIZATION  

E-Print Network [OSTI]

................................................................................................................................................... MASS POLITICAL MOBILIZATION ................................................................................................................................................... Boix & Stokes: The Oxford Handbook of Comparative Politics Boixandstokes-chap21 Revise Proof page 497 20.4.2007 12:41pm #12;Boix & Stokes: The Oxford Handbook of Comparative Politics Boixandstokes-chap21

413

Masses of Fundamental Particles  

E-Print Network [OSTI]

In the original paper entitled, "Masses of Fundamental Particles"(arXiv:1109.3705v5, 10 Feb 2012), not only the masses of fundamental particles including the weak bosons, Higgs boson, quarks, and leptons, but also the mixing angles of quarks and those of neutrinos are all explained and/or predicted in the unified composite models of quarks and leptons successfully. In this addendum entitled, "Higgs Boson Mass in the Minimal Unified Subquark Model", it is emphasized that the Higgs boson mass is predicted to be about 130Gev in the minimal unified subquark model, which agrees well with the experimental values of 125-126GeV recently found by the ATLAS and CMS Collaborations at the LHC.

Hidezumi Terazawa

2014-06-11T23:59:59.000Z

414

Heavy Hybrid mesons Masses  

E-Print Network [OSTI]

We estimate the ground state masses of the heavy hybrid mesons using a phenomenological QCD-type potential. 0^{- -},1^{- -},0^{- +},1^{- +} and 0^{+ -} J^{PC} states are considered.

F. Iddir; L. Semlala

2006-11-13T23:59:59.000Z

415

Direct analysis of samples by mass spectrometry: From elements to bio-molecules using laser ablation inductively couple plasma mass spectrometry and laser desorption/ionization mass spectrometry  

SciTech Connect (OSTI)

Mass spectrometric methods that are able to analyze solid samples or biological materials with little or no sample preparation are invaluable to science as well as society. Fundamental research that has discovered experimental and instrumental parameters that inhibit fractionation effects that occur during the quantification of elemental species in solid samples by laser ablation inductively coupled plasma mass spectrometry is described. Research that determines the effectiveness of novel laser desorption/ionization mass spectrometric methods for the molecular analysis of biological tissues at atmospheric pressure and at high spatial resolution is also described. A spatial resolution is achieved that is able to analyze samples at the single cell level.

Perdian, David C.

2009-08-19T23:59:59.000Z

416

HIGEE Mass Transfer  

E-Print Network [OSTI]

HIGEE MASS TRANSFER R.J. Mohr and R. Fowler GLITSCH, INC. Dallas, Texas ABSTRACT Distillation, absorption, and gas stripping have traditionally been performed in tall columns utilizing trays or packing. Columns perform satisfactorily... transfer system which utilizes a rotating bed of packing to achieve high efficiency separations, and consequent reduction in size and weight. INTRODUCTION HIGEE is probably one of the most interesting developments in mass transfer equipment made...

Mohr, R. J.; Fowler, R.

417

Photonuclear Reaction Cross Sections for Gallium Isotopes  

E-Print Network [OSTI]

The photon induced reactions which are named as photonuclear reactions have a great importance in many field of nuclear, radiation physics and related fields. Since we have planned to perform photonuclear reaction on gallium target with bremmstrahlung photons from clinical linear accelerator in the future, the cross-sections of neutron (photo-neutron ({\\gamma},xn)) and proton (photo-proton ({\\gamma},xn)) productions after photon activation have been calculated by using TALYS 1.2 computer code in this study. The target nucleus has been considered gallium which has two stable isotopes, 69Ga and 71Ga. According to the results, we have seen that the calculations are in harmony in the limited literature values. Furthermore, the pre-equilibrium and compound process contributions to the total cross-section have been investigated.

Serkan Akkoyun; Tuncay Bayram

2014-09-08T23:59:59.000Z

418

Microscopic description of fission in Uranium isotopes with the Gogny energy density functional  

E-Print Network [OSTI]

The most recent parametrizations D1S, D1N and D1M of the Gogny energy density functional are used to describe fission in the isotopes $^{232-280}$ U. Fission paths, collective masses and zero point quantum corrections, obtained within the constrained Hartree-Fock-Bogoliubov approximation, are used to compute the systematics of the spontaneous fission half-lives $t_\\mathrm{SF}$, the masses and charges of the fission fragments as well as their intrinsic shapes. The Gogny-D1M parametrization has been benchmarked against available experimental data on inner and second barrier heights, excitation energies of the fission isomers and half-lives in a selected set of Pu, Cm, Cf, Fm, No, Rf, Sg, Hs and Fl nuclei. It is concluded that D1M represents a reasonable starting point to describe fission in heavy and superheavy nuclei. Special attention is also paid to understand the uncertainties in the predicted $t_\\mathrm{SF}$ values arising from the different building blocks entering the standard semi-classical Wentzel-Kramers-Brillouin formula. Although the uncertainties are large, the trend with mass or neutron numbers are well reproduced and therefore the theory still has predictive power. In this respect, it is also shown that modifications of a few per cent in the pairing strength can have a significant impact on the collective masses leading to uncertainties in the $t_\\mathrm{SF}$ values of several orders of magnitude.

R. Rodriguez-Guzman; L. M. Robledo

2014-05-25T23:59:59.000Z

419

Chiral three-nucleon forces and the evolution of correlations along the oxygen isotopic chain  

E-Print Network [OSTI]

The impact of three-nucleon forces (3NFs) along the oxygen chain is investigated for the spectral distribution for attachment and removal of a nucleon, spectroscopic factors and matter radii. We employ self-consistent Green's function (SCGF) theory which allows a comprehensive calculation of the single particle spectral function. For the closed subshell isotopes, $^{14}$O, $^{16}$O, $^{22}$O, $^{24}$O and $^{28}$O, we perform calculations with the Dyson-ADC(3) method. The remaining open shell isotopes are studied using the newly developed Gorkov-SCGF formalism up to second order. We produce plots for the full-fledged spectral distributions. The spectroscopic factors for the dominant quasiparticle peaks are found to depend very little on the leading order (NNLO) chiral 3NFs. The latters have small impact on the calculated matter radii, which, however are consistently obtained smaller than experiment. Similarly, single particle spectra tend to be diluted with respect to experiment. This effect might hinder, to some extent, the onset of correlations and screen the quenching of calculated spectroscopic factors. The most important effects of 3NFs is thus the fine tuning of the energies for the dominant quasiparticle states, which govern the shell evolution and the position of driplines. Although present chiral NNLO 3NFs interactions do reproduce the binding energies correctly in this mass region, the details of the nuclear wave function remain at odd with the experiment showing too small radii and a too dilute single particle spectrum, similar to what already pointed out for larger masses. This suggests a lack of repulsion in the present model of NN+3N interactions which is mildly apparent already for masses in the A=14--28 range.

A. Cipollone; C. Barbieri; P. Navrátil

2014-12-01T23:59:59.000Z

420

In-situ remediation of naturally occurring radioactive materials with high-permeability hydraulic fracturing  

E-Print Network [OSTI]

IN-SITU REMEDIATION OF NATURALLY OCCURRING RADIOACTIVE MATERIALS WITH HIGH-PERMEABILITY HYDRAULIC FRACTURING A Thesis by ANDRONIKOS STAVROS DEMARCHOS Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment... Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Approved as to style and content by: Michael J. Economides (Chair of Committee) ulat D. Mamora (Member...

Demarchos, Andronikos Stavros

1998-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Breeding and wintering bird occurence in Texas rangelands with special reference to woody plant encroachment  

E-Print Network [OSTI]

mosaic of shrub densities across the landscape. Moderate to heavy livestock grazing, primarily cattle with some sheep and goats, occurs throughout the study area. Reagan County Tom Green CountY ~ nil ~ Winter Survey Site ~ Breert tag Survey Site... owned. Although many ranchers would like to reduce woody cover in order to improve grazing condition, others manage stands of woody vegetation for deer hunting leases. The landscape may always be a diverse mosaic due to landowner preference...

Magness, Dawn Robin

2003-01-01T23:59:59.000Z

422

The JET Hydrogen-Oxygen Recombination Sensor – A Safety Device for Hydrogen Isotope Processing Systems  

E-Print Network [OSTI]

The JET Hydrogen-Oxygen Recombination Sensor – A Safety Device for Hydrogen Isotope Processing Systems

423

Stable isotope studies. Final report, March 1, 1972--February 29, 1992  

SciTech Connect (OSTI)

The research has been in four general areas: (1) correlation of isotope effects with molecular forces and molecular structures, (2) correlation of zero-point energy and its isotope effects with molecular structure and molecular forces, (3) vapor pressure isotope effects, and (4) fractionation of stable isotopes. 73 refs, 38 figs, 29 tabs.

Ishida, T.

1992-10-01T23:59:59.000Z

424

Evolution of the geothermal fluids at Los Azufres, Mexico, as traced by noble gas isotopes, 18  

E-Print Network [OSTI]

Evolution of the geothermal fluids at Los Azufres, Mexico, as traced by noble gas isotopes, 18 O, D: Noble gases Strontium isotopes Helium isotopes Geothermal energy Los Azufres Araró Mexico Isotopes of noble gases, CO2, H2O and Sr were measured in 10 geothermal wells and 8 hot springs, fumaroles and mud

Long, Bernard

425

Glaciation, aridification, and carbon sequestration in the Permo-Carboniferous: The isotopic record from low latitudes  

E-Print Network [OSTI]

Glaciation, aridification, and carbon sequestration in the Permo-Carboniferous: The isotopic record and carbon sequestration in the Late Paleozoic, we have compiled new and published oxygen and carbon isotopic Carboniferous Stable isotopes Carbon cycling Brachiopods To evaluate the isotopic record of climate change

Grossman, Ethan L.

426

Preservation of seawater Sr and Nd isotopes in fossil sh teeth: bad news and good news  

E-Print Network [OSTI]

system, our Nd concentration data, combined with published isotopic and rare earth element data, suggest on the global seawater Sr isotope curve. For Sites 1090, 757, and 807 Sr isotopic values of the pore fluids Nd isotopic compositions from the time of deposition. Ã? 2004 Elsevier B.V. All rights reserved

Martin, Ellen

427

Isotope and Nuclear Chemistry Division annual report, FY 1983  

SciTech Connect (OSTI)

This report describes progress in the major research and development programs carried out in FY 1983 by the Isotope and Nuclear Chemistry Division. It covers radiochemical diagnostics of weapons tests; weapons radiochemical diagnostics research and development; other unclassified weapons research; stable and radioactive isotope production, separation, and applications (including biomedical applications); element and isotope transport and fixation; actinide and transition metal chemistry; structural chemistry, spectroscopy, and applications; nuclear structure and reactions; irradiation facilities; advanced analytical techniques; development and applications; atmospheric chemistry and transport; and earth and planetary processes.

Heiken, J.H.; Lindberg, H.A. (eds.)

1984-05-01T23:59:59.000Z

428

Arbitrary mass Majorana neutrinos in neutrinoless double beta decay  

E-Print Network [OSTI]

We revisit the mechanism of neutrinoless double beta (NLDBD) decay mediated by the exchange with the heavy Majorana neutrino N of arbitrary mass mN, slightly mixed with the electron neutrino. By assuming the dominance of this mechanism, we update the well-known NLDBD-decay exclusion plot in the mass-mixing angle plane taking into account recent progress in the calculation of nuclear matrix elements within quasiparticle random phase approximation and improved experimental bounds on the NLDBD-decay half-life of Ge-76 and Xe-136. We also consider the known formula approximating the mN dependence of the NLDBD-decay nuclear matrix element in a simple explicit form. We analyze its accuracy and specify the corresponding parameters, allowing one to easily calculate the NLDBD-decay half-life for arbitrary mN for all the experimentally interesting isotopes without resorting to real nuclear structure calculations.

Amand Faessler; Marcela Gonzalez; Sergey Kovalenko; Fedor Simkovic

2014-08-26T23:59:59.000Z

429

Standard test methods for chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of uranium hexafluoride  

E-Print Network [OSTI]

1.1 These test methods cover procedures for subsampling and for chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of uranium hexafluoride UF6. Most of these test methods are in routine use to determine conformance to UF6 specifications in the Enrichment and Conversion Facilities. 1.2 The analytical procedures in this document appear in the following order: Note 1—Subcommittee C26.05 will confer with C26.02 concerning the renumbered section in Test Methods C761 to determine how concerns with renumbering these sections, as analytical methods are replaced with stand-alone analytical methods, are best addressed in subsequent publications. Sections Subsampling of Uranium Hexafluoride 7 - 10 Gravimetric Determination of Uranium 11 - 19 Titrimetric Determination of Uranium 20 Preparation of High-Purity U3O 8 21 Isotopic Analysis 22 Isotopic Analysis by Double-Standard Mass-Spectrometer Method 23 - 29 Determination of Hydrocarbons, Chlorocarbons, and Partially Substitut...

American Society for Testing and Materials. Philadelphia

2011-01-01T23:59:59.000Z

430

Atomic mass compilation 2012  

SciTech Connect (OSTI)

Atomic mass reflects the total binding energy of all nucleons in an atomic nucleus. Compilations and evaluations of atomic masses and derived quantities, such as neutron or proton separation energies, are indispensable tools for research and applications. In the last decade, the field has evolved rapidly after the advent of new production and measuring techniques for stable and unstable nuclei resulting in substantial ameliorations concerning the body of data and their precision. Here, we present a compilation of atomic masses comprising the data from the evaluation of 2003 as well as the results of new measurements performed. The relevant literature in refereed journals and reports as far as available, was scanned for the period beginning 2003 up to and including April 2012. Overall, 5750 new data points have been collected. Recommended values for the relative atomic masses have been derived and a comparison with the 2003 Atomic Mass Evaluation has been performed. This work has been carried out in collaboration with and as a contribution to the European Nuclear Structure and Decay Data Network of Evaluations.

Pfeiffer, B., E-mail: bpfeiffe@uni-mainz.de [II. Physikalisches Institut, Justus-Liebig-Universität Gießen, Gießen (Germany); GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt (Germany); Venkataramaniah, K. [Sri Sathya Sai Institute of Higher Learning, Prasanthinilayam (India)] [Sri Sathya Sai Institute of Higher Learning, Prasanthinilayam (India); Czok, U. [II. Physikalisches Institut, Justus-Liebig-Universität Gießen, Gießen (Germany)] [II. Physikalisches Institut, Justus-Liebig-Universität Gießen, Gießen (Germany); Scheidenberger, C. [GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt (Germany) [GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt (Germany); II. Physikalisches Institut, Justus-Liebig-Universität Gießen, Gießen (Germany)

2014-03-15T23:59:59.000Z

431

High Flux Isotope Reactor named Nuclear Historic Landmark | ornl...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

late 1950s as a production reactor to meet anticipated demand for transuranic isotopes ("heavy" elements such as plutonium and curium). HFIR today is a DOE Office of Science User...

432

Isotope Geochemistry of Thermal and Nonthermal Waters in the...  

Open Energy Info (EERE)

geothermal fluids display a positive oxygen 18 shift of not less than 2 because of rock-water isotopic exchange at 220-300C. The Valles geothermal system is capped by a...

433

Isotopic Effect on Ion Mobility and Separation of Isotopomers...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Effect on Ion Mobility and Separation of Isotopomers by High-Field Ion Mobility Spectrometry . Isotopic Effect on Ion Mobility and Separation of Isotopomers by High-Field Ion...

434

Surface-cycling of rhenium and its isotopes  

E-Print Network [OSTI]

The application of elemental and isotopic metal palaeoredox tracers to the geologic past rests on an understanding of modern metal cycles. This study reevaluates the surface-cycling of Mo and Re in near-surface reservoirs. ...

Miller, Christian Alexander

2009-01-01T23:59:59.000Z

435

CONSERVATION ECOLOGY -ORIGINAL RESEARCH Conservation through connectivity: can isotopic gradients  

E-Print Network [OSTI]

CONSERVATION ECOLOGY - ORIGINAL RESEARCH Conservation through connectivity: can isotopic gradients Abstract Conservation of migratory wildlife requires knowledge of migratory connectivity between breeding conservation efforts for endangered migratory species (Webster et al. 2002; Rubenstein and Hobson 2004; Webster

Richner, Heinz

436

Preliminary study: isotopic safeguards techniques (IST) LMFBR fuel cycles  

SciTech Connect (OSTI)

This memorandum presents the preliminary results of the effort to investigate the applicability of isotope correlation techniques (ICT), formulated for the LWR system, to the LMFBR fuel cycle. The detailed isotopic compositional changes with burnup developed for the CRBR was utilized as the reference case. This differs from the usual LMFBR design studies in that the core uranium is natural uranium rather than depleted. Nevertheless, the general isotopic behavior should not differ significantly and does allow an initial insight into the expected behavior of isotopic correlations for the LMFBR power systems such as: the U.K. PFR and reprocessing plant; the French Phenix and Superphenix; and the US reference conceptual design studies (CDS) of homogeneous and heterogeneous LMFBR systems as they are developed.

Persiani, P.J.; Kroc, T.K.

1980-06-01T23:59:59.000Z

437

FY09 PROGRESS: MULTI-ISOTOPE PROCESS (MIP) MONITOR  

SciTech Connect (OSTI)

Model and experimental estimates of the Multi-Isotope Process Monitor performance for determining burnup after dissolution and acid concentration during solvent extraction steps during reprocessing of spent nuclear fuel are presented.

Schwantes, Jon M.; Orton, Christopher R.; Fraga, Carlos G.; Christensen, Richard; Laspe, Amy R.; Ward, Rebecca M.

2009-10-18T23:59:59.000Z

438

Process for exchanging hydrogen isotopes between gaseous hydrogen and water  

DOE Patents [OSTI]

A process for exchanging isotopes of hydrogen, particularly tritium, between gaseous hydrogen and water is provided whereby gaseous hydrogen depeleted in tritium and liquid or gaseous water containing tritium are reacted in the presence of a metallic catalyst.

Hindin, Saul G. (Mendham, NJ); Roberts, George W. (Westfield, NJ)

1980-08-12T23:59:59.000Z

439

Delayed neutron energy spectrum measurements of actinide waste isotopes  

E-Print Network [OSTI]

was irradiated using the Texas A&M Nuclear Science Center Reactor (NSCR). Three proton recoil detectors, operating individually, in conjunction with MCNP calculated response functions, were used to measure the delayed neutron energy spectra of each isotope...

Comfort, Christopher M.

2012-06-07T23:59:59.000Z

440

COLLOQUIUM: Facility for Rare Isotope Beams - Scientific Opportunities...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

2015, 4:00pm to 5:30pm Colloquia MBG Auditorium COLLOQUIUM: Facility for Rare Isotope Beams - Scientific Opportunities and Technical Challenges Dr. Georg Bollen Michigan State...

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

acid selective isotope: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Bchner; Grard Trnec; Jacques Vigu 2006-11-17 20 LACK OF CORRELATION BETWEEN GOUT AND THE INCORPORATION OF ISOTOPIC FORMATE INTO URIC ACID CiteSeer Summary: Certain...

442

Mantle Helium And Carbon Isotopes In Separation Creek Geothermal...  

Open Energy Info (EERE)

we present the helium and carbon isotope results from the initial study of a fluid chemistry-monitoring program started in the summer of 2001 near the South Sister volcano in...

443

AN INVESTIGATION OF THE ISOTOPES OF AMERICIUM AND CURIUM  

E-Print Network [OSTI]

OF THE ISOTOPES OF AMERICIUM AND CURIUM Gary Hoyt Higgins (of alpha particles of americium produced by bombarding puMU3507 Fig. 2. Decay of americium produced by bombardment of

Higgins, Gary Hoyt.

2011-01-01T23:59:59.000Z

444

Intraseasonal variability in South America recorded in stable water isotopes  

E-Print Network [OSTI]

Intraseasonal variability in South America recorded in stable water isotopes Christophe Sturm,1 cores (South America) has illustrated the key role such archives can play in past climate South America, highlighting the internal atmospheric variability, as opposed to external forcing

Sturm, Christophe "Kristof"

445

The Nonactinide Isotope and Sealed Sources Management Group  

SciTech Connect (OSTI)

The Nonactinide Isotope and Sealed Sources Management Group (NISSMG) is sponsored by the Department of Energy (DOE) Office of Environmental Management and managed by Albuquerque Operations Office (DOE/AL) to serve as a complex-wide resource for the management of DOE-owned Nonactinide Isotope and Sealed Source (NISS) materials. NISS materials are defined as including: any isotope in sealed sources or standards; and isotopes, regardless of form, with atomic number less than 90. The NISSMG assists DOE sites with the storage, reuse, disposition, transportation, and processing of these materials. The NISSMG has focused its efforts to date at DOE closure sites due to the immediacy of their problems. Recently, these efforts were broadened to include closure facilities at non-closure sites. Eventually, the NISSMG plans to make its resources available to all DOE sites. This paper documents the lessons learned in managing NISS materials at DOE sites to date.

Low, J. L.; Polansky, G. F.; Parks, D. L.

2002-02-27T23:59:59.000Z

446

The marine geochemistry of iron and iron isotopes  

E-Print Network [OSTI]

This thesis addressed questions about the Fe cycle by measuring detailed profiles and transects of Fe species in the ocean and also by exploring the use of a new tracer of Fe, Fe isotopic fractionation. In the subtropical ...

Bergquist, Bridget A., 1973-

2004-01-01T23:59:59.000Z

447

abundance isotopic: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

24 Abundances and Isotope Ratios in the Magellanic Clouds: The Star Forming Environment of N113 Astrophysics (arXiv) Summary: With the goal of deriving the physical and...

448

Proton magnetic resonance studies of the chemical shifts occurring in propionic acid-dioxane solutions  

E-Print Network [OSTI]

, Nxperimentaliy Gutowsky 1'ound S to be a linear function of Pl, Howevers Bhar end Lindstrom(I~ found deviations from the linear de- pendence g1ven in Gutowsky's report, These deviat1ons occur in the range of 5Q of acid by volume. The shift does not decrease... lines are displayed as the f10IlL is swept through 'the resonant value Since it was desire4 to find if the cheaical shift is tesperature de pendent~ 1t vas decided to neasure the shift at two tenperatures, One of those vas to be roc' tenperatuze...

Oldham, William J. Bryan

1958-01-01T23:59:59.000Z

449

Determination of thorium in seawater by neutron activation analysis and mass spectrometry  

SciTech Connect (OSTI)

The recent development of neutron activation analysis and mass spectrometric methods for the determination of /sup 232/Th in seawater has made possible rapid sampling and analysis of this long-lived, non-radiogenic thorium isotope on small-volume samples. The marine geochemical utility of /sup 232/Th, whose concentration in seawater is extremely low, warrants the development of these sensitive techniques. The analytical methods and some results are presented and discussed in this article. 24 refs., 3 figs.

Huh, Chih-An

1987-01-01T23:59:59.000Z

450

High efficiency resonance ionization mass spectrometric analysis by external laser cavity enhancement techniques  

SciTech Connect (OSTI)

The demand to measure high dynamic range isotope ratios on small samples with resonance ionization mass spectrometry (RIMS) continues to increase. This paper discusses high ionization efficiency methods which can be applied to continuous wave (cw) RIMS to potentially achieve several tens of percent ionization efficiencies for certain elements. The primary technique under development to achieve this is an external laser cavity which can generate very high circulating laser powers. 12 refs., 3 figs.

Johnson, S.G.; Rios, E.L.; Miller, C.M.; Fearey, B.L.

1991-01-01T23:59:59.000Z

451

Electron impact and chemical ionization mass spectral analysis of a volatile uranyl derivative  

SciTech Connect (OSTI)

Quadrupole mass spectral analysis of the volatile uranium ligand complex bis (1,1,1,5,5,5-hexafluoro-2,4-pentanedionato) dioxouranium-di-n-butyl sulfoxide is described utilizing electron impact (EI) and methane chemical ionization (CI) ion sources. All major ions are tentatively identified and the potential usefulness of this complex for determining uranium isotope /sup 235/U//sup 238/U abundance is demonstrated.

Reutter, D.J.; Hardy, D.R.

1981-01-01T23:59:59.000Z

452

Galaxy Cosmological Mass Function  

E-Print Network [OSTI]

We study the galaxy cosmological mass function (GCMF) in a semi-empirical relativistic approach using observational data provided by galaxy redshift surveys. Starting from the theory of Ribeiro & Stoeger (2003, arXiv:astro-ph/0304094) between the mass-to-light ratio, the selection function obtained from the luminosity function (LF) data and the luminosity density, the average luminosity $L$ and the average galactic mass $\\mathcal{M}_g$ are computed in terms of the redshift. $\\mathcal{M}_g$ is also alternatively estimated by a method that uses the galaxy stellar mass function (GSMF). Comparison of these two forms of deriving the average galactic mass allows us to infer a possible bias introduced by the selection criteria of the survey. We used the FORS Deep Field galaxy survey sample of 5558 galaxies in the redshift range $0.5 light ratio and its GSMF data. Assuming ${\\mathcal{M}_{g_0}} \\approx 10^{11} \\mathcal{M}_\\odot$ as the local value of the average galactic mass, the LF approach results in $L_{B} \\propto (1+z)^{(2.40 \\pm 0.03)}$ and $\\mathcal{M}_g \\propto (1+z)^{(1.1\\pm0.2)}$. However, using the GSMF results produces $\\mathcal{M}_g \\propto (1+z)^{(-0.58 \\pm 0.22)}$. We chose the latter result as it is less biased. We then obtained the theoretical quantities of interest, such as the differential number counts, to calculate the GCMF, which can be fitted by a Schechter function. The derived GCMF follows theoretical predictions in which the less massive objects form first, being followed later by more massive ones. In the range $0.5 < z < 2.0$ the GCMF has a strong variation that can be interpreted as a higher rate of galaxy mergers or as a strong evolution in the star formation history of these galaxies.

Amanda R. Lopes; Alvaro Iribarrem; Marcelo B. Ribeiro; William R. Stoeger

2014-12-03T23:59:59.000Z

453

Stable isotopes composition of precipitation fallen over Cluj-Napoca, Romania, between 2009-2012  

SciTech Connect (OSTI)

The paper presents the deuterium and oxygen 18 content from All precipitations events, which have occured over Cluj-Napoca, Romania from 2009 until 2012. Time series for ?{sup 2}H and ?{sup 18}O values point out both the seasonal variation that has increased amplitude reflecting the continental character of the local climate as well as dramatic variations of isotopic content of successive precipitation events, emphasizing the anomalous values. These fluctuations are the footprint of the variations and trends in climate events. Local Meteoric Water Line (LMWL), reflecting the ?{sup 2}H - ?{sup 18}O correlation, has the slop and the intercept slightly deviated from the GMWL, indicating that the dominant process affecting local precipitations are close to the equilibrium condition. LMWL has a slope smaller then that of the GMWL in the warm season due to lower humidity and a slope closest to the slop of GMWL in cold season with high humidity. The ?{sup 2}H and ?{sup 18}O values both for the precipitation events and monthly mean values are positively correlated with the temperature values with a very good correlation factor. The values of ?{sup 2}H and ?{sup 18}O are not correlated with amount of precipitation, the 'amount effect' of isotopic composition of precipitation is not observed for this site.

Puscas, R.; Feurdean, V. [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath Str., 400293 Cluj-Napoca (Romania)] [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath Str., 400293 Cluj-Napoca (Romania); Simon, V. [Babes-Bolyai University Faculty of Physics (Romania)] [Babes-Bolyai University Faculty of Physics (Romania)

2013-11-13T23:59:59.000Z

454

D/H isotope ratios of kerogen, bitumen, oil, and water in hydrous pyrolysis of source rocks containing kerogen types I, II, IIS, and III  

SciTech Connect (OSTI)

Immature source rock chips containing different types of kerogen (I,II,IIS,III) were artificially matured in isotopically distinct waters by hydrous pyrolysis and by pyrolysis in supercritical water. Converging isotopic trends of inorganic (water) and organic (kerogen, bitumen, oil) hydrogen with increasing time and temperature document that water-derived hydrogen is added to or exchanged with organic hydrogen, or both, during chemical reactions that take place during thermal maturation. Isotopic mass-balance calculations show that, depending on temperature (310--381 C), time (12--144h), and source rock type, between ca. 45 and 79% of carbon-bound hydrogen in kerogen is derived from water. Estimates for bitumen and oil range slightly lower, with oil-hydrogen being least affected by water-derived hydrogen. Comparative hydrous pyrolyses of immature source rocks at 330 C for 72h show that hydrogen in kerogen, bitumen, and expelled oil/wax ranks from most to least isotopically influenced by water-derived hydrogen in the order IIS {gt} II {approximately} III {gt} I. Pyrolysis of source rock containing type II kerogen in supercritical water at 381 C for 12 h yields isotopic results that are similar to those from hydrous pyrolysis at 250 C for 72 h or 330 C for 133 h. Bulk hydrogen in kerogen contains several percent of isotopically labile hydrogen that exchanges fast and reversibly with hydrogen in water vapor at 115 C. The isotopic equilibration of labile hydrogen in kerogen with isotopic standard water vapors significantly reduces the analytical uncertainty of D/H ratios when compared with simple D/H determination of bulk hydrogen in kerogen. If extrapolation of their results from hydrous pyrolysis is permitted to natural thermal maturation at lower temperatures, the authors suggest that organic D/H ratios of fossil fuels in contact with formation water are typically altered during chemical reactions, but that D/H ratios of generated hydrocarbons are subsequently little or not affected by exchange with water hydrogen at typical reservoir conditions over geologic time. It will be difficult to utilize D/H ratios of thermally mature bulk or fractions or organic matter to quantitatively reconstruct isotopic aspects of paleoclimate and paleoenvironment. Hope resides in compound-specific D/H ratio of thermally stable, extractable biomarkers (molecular fossils) that are less susceptible to hydrogen exchange with water-derived hydrogen.

Schimmelmann, A.; Lewan, M.D.; Wintsch, R.P.

1999-11-01T23:59:59.000Z

455

Mass of Ne-16  

E-Print Network [OSTI]

1983 The American Physical Society 28 C. J. WOODWARD, R. E. TRIBBLE, AND D. M. TANNER 27 tron rf. A 0.3 mm Kapton absorber foil was insert- ed after the proportional counter in order to ensure that the He particles stopped in the Si detector...PHYSICAL REVIEWER C VOLUME 27, NUMBER 1 Mass of ' Ne JANUARY 1983 C. J. Woodward, * R. E. Tribble, and D. M. Tanner Cyclotron Institute, Texas A&M University, College Station, Texas 77843 (Received 23 August 1982) The mass of ' Ne has been...

Woodward, C. J.; Tribble, Robert E.; Tanner, D. M.

1983-01-01T23:59:59.000Z

456

Ca isotopic anomaly in the atmospheres of Ap stars  

E-Print Network [OSTI]

We present results of the Ca stratification analysis in the atmospheres of 21 magnetic chemically peculiar (Ap) stars. This analysis was based on the spectral observations carried out with the UVES spectrograph attached to the 8-m VLT telescope. Ca was found to be strongly stratified in all stars with different effective temperatures and magnetic field strengths. This element is overabundant by 1-1.5 dex below logtau_5000~-1 and strongly depleted above logtau_5000=-1.5. Based on the overall Ca abundance distributions, we modelled a profile of the IR-triplet Ca II 8498 line. It shows a significant contribution of the heavy isotopes 46Ca and 48Ca, which represent less than 1% of the solar Ca isotopic mixture. In Ap stars with the relatively small surface magnetic fields (Ca isotope is concentrated close to the photosphere, while the heavy isotopes are pushed towards the outer layers. Isotopic separation disappears in the atmospheres of stars with magnetic fields above 6-7 kG. The observed overall Ca stratification and isotopic anomalies may be explained by a combined action of the radiatively-driven diffusion and the light-induced drift.

T. Ryabchikova; O. Kochukhov; S. Bagnulo

2007-03-13T23:59:59.000Z

457

Shell-model study of quadrupole collectivity in light tin isotopes  

E-Print Network [OSTI]

A realistic shell-model study is performed for neutron-deficient tin isotopes up to mass A=108. All shell-model ingredients, namely two-body matrix elements, single-particle energies, and effective charges for electric quadrupole transition operators, have been calculated by way of the many-body perturbation theory, starting from a low-momentum interaction derived from the high-precision CD-Bonn free nucleon-nucleon potential. The focus has been put on the enhanced quadrupole collectivity of these nuclei, which is testified by the observed large B(E2;0+ -> 2+)s. Our results evidence the crucial role played by the Z=50 cross-shell excitations that need to be taken into account explicitly to obtain a satisfactory theoretical description of light tin isotopes. We find also that a relevant contribution comes from the calculated neutron effective charges, whose magnitudes exceed the standard empirical values. An original double-step procedure has been introduced to reduce effectively the model space in order to ov...

Coraggio, L; Gargano, A; Itaco, N; Kuo, T T S

2015-01-01T23:59:59.000Z

458

Shell-model study of quadrupole collectivity in light tin isotopes  

E-Print Network [OSTI]

A realistic shell-model study is performed for neutron-deficient tin isotopes up to mass A=108. All shell-model ingredients, namely two-body matrix elements, single-particle energies, and effective charges for electric quadrupole transition operators, have been calculated by way of the many-body perturbation theory, starting from a low-momentum interaction derived from the high-precision CD-Bonn free nucleon-nucleon potential. The focus has been put on the enhanced quadrupole collectivity of these nuclei, which is testified by the observed large B(E2;0+ -> 2+)s. Our results evidence the crucial role played by the Z=50 cross-shell excitations that need to be taken into account explicitly to obtain a satisfactory theoretical description of light tin isotopes. We find also that a relevant contribution comes from the calculated neutron effective charges, whose magnitudes exceed the standard empirical values. An original double-step procedure has been introduced to reduce effectively the model space in order to overcome the computational problem.

L. Coraggio; A. Covello; A. Gargano; N. Itaco; T. T. S. Kuo

2015-04-13T23:59:59.000Z

459

Investigations of the g{sub K}-factors in the {sup 175,177,179}Hf Isotopes  

SciTech Connect (OSTI)

In this paper the intrinsic g{sub K} and effective spin g{sub s} factors of the odd-mass {sup 175-179}Hf isotopes have been investigated within the Tamm-Dancoff approximation by using the realistic Saxon-Woods potential. The theoretically calculated g{sub K} and g{sub s}{sup eff} values are compared with experimental data. The comparison of the measured and calculated values of the effective g{sub s} factor shows that the spin polarization explains quite well the observed reduction of g{sub s} from its free-nucleon value.

Yakut, Hakan; Kuliev, Ali [Sakarya University, Department of physics, Sakarya (Turkey); Guliyev, Ekber [National Academy of Sciences, Institute of Physics, Baku (Azerbaijan)

2008-11-11T23:59:59.000Z

460

Lithium isotopic systematics of A-type granites and their mafic enclaves: Further constraints on the Li isotopic composition of the continental crust  

E-Print Network [OSTI]

Lithium isotopic systematics of A-type granites and their mafic enclaves: Further constraints form 6 February 2009 Accepted 15 February 2009 Editor: D.B. Dingwell Keywords: Lithium isotopes A-type granite Mafic enclave Continental crust Lithium concentrations and isotopic compositions of 39 A

Mcdonough, William F.

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Mass Extinctions Geology 331  

E-Print Network [OSTI]

into shallow water and released to atmosphere. · Oxidation of coal and hydrocarbons by extensive erosion of sedimentary rocks, and/or massive volcanic eruptions in Siberia? CH2O + O2 CO2 +H2O · Release of methane by rapid influx of C12 caused by methane release and mass dying at the end of the Permian. Organisms

Kammer, Thomas

462

Residential Thermal Mass Construction  

E-Print Network [OSTI]

The southwest has long known the value of building homes with high mass materials. The ancient Pueblo Indians found that by using "adobe" they could capture the energy necessary to survive the harsh desert climate. Our ancestors knew that a heavy...

Thieken, J. S.

1988-01-01T23:59:59.000Z

463

Large break loss-of-coolant accident analyses for the high flux isotope reactor  

SciTech Connect (OSTI)

The US Department of Energy's High Flux Isotope Reactor (HFIR) was analyzed to evaluate it's response to a spectrum of loss-of-coolant accidents (LOCAs) with potential for leading to core damage. The MELCOR severe accident analysis code (version 1.7.1) was used to evaluate the overall dynamic response of HFIR. Before conducting LOCA analyses, the steady-state thermal-hydraulic parameters evaluated by MELCOR for various loop sections were verified against steady-state operating data. Thereafter, HFIR depressurization tests were simulated to evaluate the system pressure change for a given depletion in coolant inventory. Interesting and important safety-related phenomena were observed. The current analyses (which should be considered preliminary) that occur over a period from 1 to 3 seconds do not lead to core wide fuel melting. Core fluid flashing during the initial rapid depressurization does cause fuel temperature excursions due to adiabatic-like heatup. 3 refs., 4 figs.

Taleyarkhan, R.P. (Oak Ridge National Lab., TN (USA))

1989-01-01T23:59:59.000Z

464

New Mexico Center for Isotopes in Medicine  

SciTech Connect (OSTI)

The purpose of the New Mexico Center for Isotopes in Medicine (NMCIM) is to support research, education and service missions of the UNM College of Pharmacy Radiopharmaceutical Sciences Program (COP RSP) and the Cancer Research and Treatment Center (CRTC). NMCIM developed and coordinated unique translational research in cancer radioimaging and radiotherapy agents based on novel molecules developed at UNM and elsewhere. NMCIM was the primary interface for novel radioisotopes and radiochemistries developed at the Los Alamos National Laboratory (LANL) for SPECT/PET imaging and therapy. NMCIM coordinated the use of the small animal imaging facility with the CRTC provided support services to assist investigators in their studies. NMCIM developed education and training programs that benefited professional, graduate, and postdoctoral students that utilized its unique facilities and technologies. UNM COP RSP has been active in writing research and training grants, as well as supporting contract research with industrial partners. The ultimate goal of NMCIM is to bring new radiopharmaceutical imaging and therapeutic agents into clinical trials that will benefit the health and well being of cancer and other patients in New Mexico and the U.S.

Burchiel, Scott W.

2012-12-13T23:59:59.000Z

465

Primary Isotope Yields and Characteristic Properties of the Fragmenting Source in Heavy-ion Reactions near the Fermi Energies  

E-Print Network [OSTI]

For central collisions of $^{40}$Ca $+ ^{40}$Ca at 35 MeV/nucleon, the density and temperature of a fragmenting source have been evaluated in a self-consistent manner using the ratio of the symmetry energy coefficient relative to the temperature, $a_{sym}/T$, extracted from the yields of primary isotopes produced in antisymmetrized molecular dynamics (AMD) simulations. The $a_{sym}/T$ values are extracted from all isotope yields using an improved method based on the Modified Fisher Model (MFM). The values of $a_{sym}/T$ obtained, using different interactions with different density dependencies of the symmetry energy term, are correlated with the values of the symmetry energies at the density of fragment formation. Using this correlation, the fragment formation density is found to be $\\rho/\\rho_0 = 0.67 \\pm 0.02$. Using the input symmetry energy value for each interaction temperature values are extracted as a function of isotope mass $A$. The extracted temperature values are compared with those evaluated from the fluctuation thermometer with a radial flow correction.

X. Liu; W. Lin; R. Wada; M. Huang; Z. Chen; G. Q. Xiao; S. Zhang; X. Jin; J. Liu; F. Shi; P. Ren; H. Zheng; J. B. Natowitz; A. Bonasera

2014-06-13T23:59:59.000Z

466

Parity violating radiative emission of neutrino pair in heavy alkaline earth atoms of even isotopes  

E-Print Network [OSTI]

Metastable excited states ${}^3P_2, {}^3P_0$ of heavy alkaline earth atoms of even isotopes are studied for parity violating (PV) effects in radiative emission of neutrino pair (RENP). PV terms arise from interference between two diagrams containing neutrino pair emission of valence spin current and nuclear electroweak charge density proportional to the number of neutrons in nucleus. This mechanism gives large PV effects, since it does not suffer from the suppression of 1/(electron mass) usually present for non-relativistic atomic electrons. A controllable magnetic field is crucial to identify RENP process by measuring PV observables. Results of PV asymmetries under the magnetic field reversal and the photon circular polarization reversal are presented for an example of Yb atom.

M. Yoshimura; N. Sasao; S. Uetake

2014-03-26T23:59:59.000Z

467

New Superheavy Element Isotopes: 242Pu(48Ca,5n)285114  

SciTech Connect (OSTI)

The new, neutron-deficient, superheavy element isotope {sup 285}114 was produced in {sup 48}Ca irradiations of {sup 242}Pu targets at a center-of-target beam energy of 256 MeV (E* = 50 MeV). The {alpha} decay of {sup 285}114 was followed by the sequential {alpha} decay of four daughter nuclides, {sup 281}Cn, {sup 277}Ds, {sup 273}Hs, and {sup 269}Sg. {sup 265}Rf was observed to decay by spontaneous fission. The measured {alpha}-decay Q values were compared with those from a macroscopic-microscopic nuclear mass model to give insight into superheavy element shell effects. The {sup 242}Pu({sup 48}Ca,5n){sup 285}114 cross section was 0.6{sub -0.5}{sup +0.9} pb.

Ellison, Paul A; Gregorich, Kenneth E.; Berryman, Jill S.; Bleuel, Darren L.; Clark, Roderick M.; Dragojevic, Irena; Dvorak, Jan; Fallon, Paul; Fineman-Sotomayor, Carolina; Gates, Jacklyn M.; Gothe, Oliver R.; Lee, I-Yang; Loveland, Walter D.; McLaughlin, Joseph P.; Paschalis, Stefanos; Petri, Marina-Kalliopi; Qian, Jing; Stavsetra, Liv; Wiedeking, Mathis; Nitsche, Heino

2010-10-22T23:59:59.000Z

468

Correlated Strontium and Barium Isotopic Compositions of Acid-Cleaned Single Silicon Carbides from Murchison  

E-Print Network [OSTI]

We present strontium, barium, carbon, and silicon isotopic compositions of 61 acid-cleaned presolar SiC grains from Murchison. Comparison with previous data shows that acid washing is highly effective in removing both strontium and barium contamination. For the first time, by using correlated $^{88}Sr$/$^{86}Sr$ and $^{138}Ba$/$^{136}Ba$ ratios in mainstream SiC grains, we are able to resolve the effect of $^{13}C$ concentration from that of $^{13}C$-pocket mass on s-process nucleosynthesis, which points towards the existence of large $^{13}C$-pockets with low $^{13}C$ concentration in AGB stars. The presence of such large $^{13}$R-pockets with a variety of relatively low $^{13}C$ concentrations seems to require multiple mixing processes in parent AGB stars of mainstream SiC grains.

Liu, Nan; Gallino, Roberto; Davis, Andrew M; Bisterzo, Sara; Gyngard, Frank; Kaeppeler, Franz; Cristallo, Sergio; Dauphas, Nicolas; Pellin, Michael J; Dillmann, Iris

2015-01-01T23:59:59.000Z

469

Riddle of the Neutrino Mass  

E-Print Network [OSTI]

We discuss some known approaches and results as well as few new ideas concerning origins and nature of neutrino mass. The key issues include (i) connections of neutrino and charged fermions masses, relation between masses and mixing, energy scale of new physics behind neutrino mass where possibilities spread from the Planck and GUT masses down to a sub-eV scale. The data hint two different new physics involved in generation of neutrino mass. Determination of the CP phase as well as mass hierarchy can play important role in identification of new physics. It may happen that sterile neutrinos provide the key to resolve the riddle.

Smirnov, A Yu

2015-01-01T23:59:59.000Z

470

Systems and methods for facilitating hydrogen storage using naturally occurring nanostructure assemblies  

DOE Patents [OSTI]

Some or all of the needs above can be addressed by embodiments of the invention. According to embodiments of the invention, systems and methods for facilitating hydrogen storage using naturally occurring nanostructure assemblies can be implemented. In one embodiment, a method for storing hydrogen can be provided. The method can include providing diatoms comprising diatomaceous earth or diatoms from a predefined culture. In addition, the method can include heating the diatoms in a sealed environment in the presence of at least one of titanium, a transition metal, or a noble metal to provide a porous hydrogen storage medium. Furthermore, the method can include exposing the porous hydrogen storage medium to hydrogen. In addition, the method can include storing at least a portion of the hydrogen in the porous hydrogen storage medium.

Fliermans; , Carl B. (Augusta, GA)

2012-08-07T23:59:59.000Z

471

On the initial phenomena occurring in lead/lead collisions at relativistic energies  

E-Print Network [OSTI]

A new study of the initial phenomena occurring in the fireball should confirm the predicted creation of a new state of nuclear matter having a lifetime of 0.17 yoctosecond and releasing an energy of 3.87 GeV. The energy-time uncertainty relation might be connected with an up to now unsuspected momentum-position uncertainty relation holding in a three-dimensional time. This new point of view leads to the interpretation of the charge of a particle as being a rotational motion in time, to a new interpretation of inertia, and to a new interpretation of the color of a particle. The transverse momentum observed in the study of the fireball might be the signature of this motion in time of the charge.

C. Ythier; G. Mouze

2012-12-18T23:59:59.000Z

472

Structure and composition of phases occurring in austenitic stainless steels in thermal and irradiation environments  

SciTech Connect (OSTI)

Transmission electron diffraction techniques coupled with quantitative x-ray energy dispersive spectroscopy have been used to characterize the phases which develop in austenitic stainless steels during exposure to thermal and to irradiation environments. In AISI 316 and Ti-modified stainless steels some thirteen phases have been identified and characterized in terms of their crystal structure and chemical composition. Irradiation does not produce any completely new phases. However, as a result of radiation-induced segregation principally of Ni and Si, and of enhanced diffusion rates, several major changes in phase relationships occur during irradiation. Firstly, phases characteristic of remote regions of the phase diagram appear unexpectedly and dissolve during postirradiation annealing (radiation-induced phases). Secondly, some phases develop with their compositions significantly altered by the incorporation of Ni or Si (radiation-modified phases).

Lee, E.H.; Maziasz, P.J.; Rowcliffe, A.F.

1980-01-01T23:59:59.000Z

473

Model independent determination of the spin of the {sup 180}Ta naturally occurring isomer  

SciTech Connect (OSTI)

The hyperfine structures of the 33715.27 cm{sup -1} and 33706.47 cm{sup -1} transitions from the ground state of singly ionized Ta have been measured by collinear laser spectroscopy. The structures were found to contain a large second order contribution. From fitting the observed hyperfine components for both {sup 181}Ta and the {sup 180}Ta naturally occurring isomer it was possible to determine the first and second order hyperfine structure coefficients. As no model independent determination of the nuclear spin of the {sup 180}Ta isomer has been performed, fitting was attempted for a range of spins. A clear chi-squared minimum is obtained for a nuclear spin of 9, in agreement with model dependent measurements.

Bissell, M. L.; Baczynska, K.; Forest, D. H.; Gardner, M. D.; Tungate, G. [School of Physics and Astronomy, The University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Billowes, J.; Campbell, P.; Cheal, B.; Tordoff, B. [Schuster Laboratory, The University of Manchester, Manchester M13 9PL (United Kingdom); Eronen, T.; Moore, I. D.; Aeystoe, J. [Department of Physics, University of Jyvaeskylae, PB 35 (YFL), FIN-40014 Jyvaeskylae (Finland)

2006-10-15T23:59:59.000Z

474

IUPAC Periodic Table of Isotopes for the Educational Community  

SciTech Connect (OSTI)

John Dalton first proposed the concept of atomic weights of the elements in the first decade of the nineteenth century. These atomic weights of the chemical elements were thought of as constants of nature, similar to the speed of light. Dmitri Mendeleev arranged the atomic weights of the elements in ascending order of value and used the systematic variation of their chemical properties to produce his Periodic Table of the Elements in 1869. Measurement of atomic weight values became an important chemical activity for a century and a half. Theodore Richards received a Noble Prize for his work in this area. In 1913, Fredrick Soddy found a species of radium, which had an atomic weight value of 228, compared to the familiar radium gas value of 226. Soddy coined the term 'isotope' (Greek for 'in the same place') to account for this second atomic weight value in the radium position of the Periodic Table. Both of these isotopes of radium are radioactive. Radioactive isotopes are energetically unstable and will decay (disintegrate) over time. The time it takes for one half of a sample of a given radioactive isotope to decay is the half-life of that isotope. In addition to having different atomic weight values, radium-226 and radium-228 also have different half-life values. Around the same time as Soddy's work, J.J. Thomson (discoverer of the electron) identified two stable (non-radioactive) isotopes of the same element, neon. Over the next 40 years, the majority of the known chemical elements were found to have two or more stable (or long-lived radioactive isotopes that contribute significantly to the determination of the atomic weights of the elements).

Holden N. E.; Holden,N.E.; Coplen,T.B.

2012-07-15T23:59:59.000Z

475

Nanoscale mass conveyors  

DOE Patents [OSTI]

A mass transport method and device for individually delivering chargeable atoms or molecules from source particles is disclosed. It comprises a channel; at least one source particle of chargeable material fixed to the surface of the channel at a position along its length; a means of heating the channel; and a means for applying an controllable electric field along the channel, whereby the device transports the atoms or molecules along the channel in response to applied electric field. In a preferred embodiment, the mass transport device will comprise a multiwalled carbon nanotube (MWNT), although other one dimensional structures may also be used. The MWNT or other structure acts as a channel for individual or small collections of atoms due to the atomic smoothness of the material. Also preferred is a source particle of a metal such as indium. The particles move by dissociation into small units, in some cases, individual atoms. The particles are preferably less than 100 nm in size.

Regan, Brian C. (Oakland, CA); Aloni, Shaul (Albany, CA); Zettl, Alexander K. (Kensington, CA)

2008-03-11T23:59:59.000Z

476

THE HEIGHT EVOLUTION OF THE ''TRUE'' CORONAL MASS EJECTION MASS DERIVED FROM STEREO COR1 AND COR2 OBSERVATIONS  

SciTech Connect (OSTI)

Using combined STEREO-A and STEREO-B EUVI, COR1, and COR2 data, we derive deprojected coronal mass ejection (CME) kinematics and CME ''true'' mass evolutions for a sample of 25 events that occurred during 2007 December to 2011 April. We develop a fitting function to describe the CME mass evolution with height. The function considers both the effect of the coronagraph occulter, at the beginning of the CME evolution, and an actual mass increase. The latter becomes important at about 10-15 R{sub Sun} and is assumed to mostly contribute up to 20 R{sub Sun }. The mass increase ranges from 2% to 6% per R{sub Sun} and is positively correlated to the total CME mass. Due to the combination of COR1 and COR2 mass measurements, we are able to estimate the ''true'' mass value for very low coronal heights (<3 R{sub Sun }). Based on the deprojected CME kinematics and initial ejected masses, we derive the kinetic energies and propelling forces acting on the CME in the low corona (<3 R{sub Sun }). The derived CME kinetic energies range between 1.0-66 Multiplication-Sign 10{sup 23} J, and the forces range between 2.2-510 Multiplication-Sign 10{sup 14} N.

Bein, B. M.; Temmer, M.; Veronig, A. M.; Utz, D. [Kanzelhoehe Observatory-IGAM, Institute of Physics, University of Graz, Universitaetsplatz 5, A-8010 Graz (Austria); Vourlidas, A. [Space Science Division, Naval Research Laboratory, Washington, DC (United States)

2013-05-01T23:59:59.000Z

477

Determination of iodine to compliment mass spectrometric measurements  

SciTech Connect (OSTI)

The dose of iodine-129 to facility personnel and the general public as a result of past, present, and future activities at DOE sites is of continuing interest, WINCO received about 160 samples annually in a variety of natural matrices, including snow, milk, thyroid tissue, and sagebrush, in which iodine-129 is determined in order to evaluate this dose, Currently, total iodine and the isotopic ratio of iodine-127 to iodine-129 are determined by mass spectrometry. These two measurements determine the concentration of iodine-129 in each sample, These measurements require at least 16 h of mass spectrometer operator time for each sample. A variety of methods are available which concentrate and determine small quantities of iodine. Although useful, these approaches would increase both time and cost. The objective of this effort was to determine total iodine by an alternative method in order to decrease the load on mass spectrometry by 25 to 50%. The preparation of each sample for mass spectrometric analysis involves a common step--collection of iodide on an ion exchange bed. This was the focal point of the effort since the results would be applicable to all samples.

Hohorst, F.A.

1994-11-01T23:59:59.000Z

478

Electrospray Ionization Mass Spectrometry  

SciTech Connect (OSTI)

Electrospray Ionization (ESI) is a process whereby gas phase ions are created from molecules in solution. As a solution exits a narrow tube in the presence of a strong electric field, an aerosol of charged droplets are is formed that produces gas phase ions as they it desolvates. ESI-MS comprises the creation of ions by ESI and the determination of their mass to charge ratio (m/z) by MS.

Kelly, Ryan T.; Marginean, Ioan; Tang, Keqi

2014-06-13T23:59:59.000Z

479

Effects of naturally occurring coumarins on hepatic drug-metabolizing enzymes inmice  

SciTech Connect (OSTI)

Cytochromes P450 (P450s) and glutathione S-transferases (GSTs) constitute two important enzyme families involved in carcinogen metabolism. Generally, P450s play activation or detoxifying roles while GSTs act primarily as detoxifying enzymes. We previously demonstrated that oral administration of the linear furanocoumarins, isopimpinellin and imperatorin, modulated P450 and GST activities in various tissues of mice. The purpose of the present study was to compare a broader range of naturally occurring coumarins (simple coumarins, and furanocoumarins of the linear and angular type) for their abilities to modulate hepatic drug-metabolizing enzymes when administered orally to mice. We now report that all of the different coumarins tested (coumarin, limettin, auraptene, angelicin, bergamottin, imperatorin and isopimpinellin) induced hepatic GST activities, whereas the linear furanocoumarins possessed the greatest abilities to induce hepatic P450 activities, in particular P450 2B and 3A. In both cases, this corresponded to an increase in protein expression of the enzymes. Induction of P4502B10, 3A11, and 2C9 by xenobiotics often is a result of activation of the pregnane X receptor (PXR) and/or constitutive androstane receptor (CAR). Using a pregnane X receptor reporter system, our results demonstrated that isopimpinellin activated both PXR and its human ortholog SXR by recruiting coactivator SRC-1 in transfected cells. In CAR transfection assays, isopimpinellin counteracted the inhibitory effect of androstanol on full-length mCAR, a Gal4-mCAR ligand-binding domain fusion, and restored coactivator binding. Orally administered isopimpinellin induced hepatic mRNA expression of Cyp2b10, Cyp3a11, and GSTa in CAR(+/+) wild-type mice. In contrast, the induction of Cyp2b10 mRNA by isopimpinellin was attenuated in the CAR(-/-) mice, suggesting that isopimpinellin induces Cyp2b10 via the CAR receptor. Overall, the current data indicate that naturally occurring coumarins have diverse activities in terms of inducing various xenobiotic metabolizing enzymes based on their chemical structure.

Kleiner, Heather E. [Department of Carcinogenesis, University of Texas M.D. Anderson Cancer Center, Science Park-Research Division, Park Road 1-C, Smithville, TX 78957 (United States)], E-mail: hklein@lsuhsc.edu; Xia, Xiaojun; Sonoda, Junichiro [Howard Hughes Medical Institute, Gene Expression Laboratory, Salk Institute for Biological Sciences, La Jolla, CA 92037 (United States); Zhang, Jun [Department of Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 (United States); Pontius, Elizabeth; Abey, Jane [Department of Carcinogenesis, University of Texas M.D. Anderson Cancer Center, Science Park-Research Division, Park Road 1-C, Smithville, TX 78957 (United States); Evans, Ronald M. [Howard Hughes Medical Institute, Gene Expression Laboratory, Salk Institute for Biological Sciences, La Jolla, CA 92037 (United States); Moore, David D. [Department of Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 (United States); DiGiovanni, John [Department of Carcinogenesis, University of Texas M.D. Anderson Cancer Center, Science Park-Research Division, Park Road 1-C, Smithville, TX 78957 (United States)

2008-10-15T23:59:59.000Z

480

Detecting infiltration and impacts of introduced water using strontium isotopes  

SciTech Connect (OSTI)

Water introduced to surface drainages, such as agricultural and roadway runoff, mine drainage, or coalbed natural gas (CBNG)-produced water, potentially can be of environmental concern. In order to mitigate potential environmental effects, it may be important to be able to trace water discharged to the surface as it infiltrates and interacts with near-surface aquifers. We have chosen to study water withdrawn during CBNG production for isotope tracing in the hyporheic zone because it poses a variety of economic, environmental, and policy issues in the Rocky Mountain states. Ground water quality must be protected as CBNG water is added to semiarid ecosystems. Strontium (Sr) isotopes are effective fingerprints of the aquifer from which water originates. In this study, CBNG water was found to have a higher Sr-87/Sr-86 ratio than the local alluvial aquifer water. This measurable difference allows the strontium isotope ratio and concentration to be used as tracers of CBNG water following its discharge to the surface. The dissolution and mobilization of salts from soil are an important contributor to ground water quality degradation. In the Powder River basin of Wyoming, the soils are calcium carbonate-buffered systems. The chemical similarity of strontium to calcium allows it to substitute into calcium minerals and enabled us to use strontium isotopes to identify calcium salts mobilized from the soil. Strontium isotopes are an effective monitor of the source of ions and the volume and direction of introduced water flow in the hyporheic zone.

Brinck, E.L.; Frost, C.D. [University of Wyoming, Laramie, WY (United States). Dept. of Geology & Geophysics

2007-09-15T23:59:59.000Z

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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481

System for recovery of daughter isotopes from a source material  

DOE Patents [OSTI]

A method of separating isotopes from a mixture containing at least two isotopes in a solution is disclosed. A first isotope is precipitated and is collected from the solution. A daughter isotope is generated and collected from the first isotope. The invention includes a method of producing an actinium-225/bismuth-213 product from a material containing thorium-229 and thorium-232. A solution is formed containing nitric acid and the material containing thorium-229 and thorium-232, and iodate is added to form a thorium iodate precipitate. A supernatant is separated from the thorium iodate precipitate and a second volume of nitric acid is added to the thorium iodate precipitate. The thorium iodate precipitate is stored and a decay product comprising actinium-225 and bismuth-213 is generated in the second volume of nitric acid, which is then separated from the thorium iodate precipitate, filtered, and treated using at least one chromatographic procedure. A system for producing an actinium-225/bismuth-213 product is also disclosed.

Tranter, Troy J. (Idaho Falls, ID) [Idaho Falls, ID; Todd, Terry A. (Aberdeen, ID) [Aberdeen, ID; Lewis, Leroy C. (Idaho Falls, ID) [Idaho Falls, ID; Henscheid, Joseph P. (Idaho Falls, ID) [Idaho Falls, ID

2009-08-04T23:59:59.000Z

482

The use of otolith strontium isotopes (87Sr/86Sr) to identify nursery habitat for a threatened estuarine fish  

E-Print Network [OSTI]

9672-3 The use of otolith strontium isotopes ( 87 Sr/ 86 Sr)relationship between strontium isotope ratios ( 87 Sr/ 86indicate that otolith strontium isotopes ( 87 Sr/ 86 Sr) are

Hobbs, James A.; Lewis, Levi S.; Ikemiyagi, Naoaki; Sommer, Ted; Baxter, Randall D.

2010-01-01T23:59:59.000Z

483

Identification of chemical sedimentary protoliths using iron isotopes in the N3750 Ma Nuvvuagittuq supracrustal belt, Canada  

E-Print Network [OSTI]

Identification of chemical sedimentary protoliths using iron isotopes in the N3750 Ma Nuvvuagittuq partly homogenized Fe isotopes. Variable Fe isotope compositions of bulk quartz­magnetite rocks

Mojzsis, Stephen J.

484

Regulatory Initiatives for Control and Release of Technologically Enhanced Naturally-Occurring Radioactive Materials  

SciTech Connect (OSTI)

Current drafts of proposed standards and suggested State regulations for control and release of technologically-enhanced naturally-occurring radioactive material (TENORM), and standards for release of volumetrically-contaminated material in the US are reviewed. These are compared to the recommendations of the International Atomic Energy Association (IAEA) Safety Series and the European Commission (EC) proposals. Past regulatory efforts with respect to TENORM in the US dealt primarily with oil-field related wastes. Currently, nine states (AK, GA, LA, MS, NM, OH, OR SC, TX) have specific regulations pertaining to TENORM, mostly based on uranium mill tailings cleanup criteria. The new US proposals are dose- or risk-based, as are the IAEA and EC recommendations, and are grounded in the linear no threshold hypothesis (LNT). TENORM wastes involve extremely large volumes, particularly scrap metal and mine wastes. Costs to control and dispose of these wastes can be considerable. The current debate over the validity of LNT at low doses and low dose rates is particularly germane to this discussion. Most standards setting organizations and regulatory agencies base their recommendations on the LNT. The US Environmental Protection Agency has released a draft Federal Guidance Report that recommends calculating health risks from low-level exposure to radionuclides based on the LNT. However, some scientific and professional organizations are openly questioning the validity of LNT and its basis for regulations, practices, and costs to society in general. It is not clear at this time how a non-linear regulatory scheme would be implemented.

Egidi, P.V.

1999-03-02T23:59:59.000Z

485

An overview of naturally occurring radioactive materials (NORM) in the petroleum industry  

SciTech Connect (OSTI)

Oil and gas extraction and processing operations sometimes accumulate naturally occurring radioactive materials (NORM) at concentrations above normal in by-product waste streams. Results from NORM surveys indicate that radionuclide concentrations can be quite variable, ranging from undetectable to extremely high levels. To date, efforts to characterize the geographic distribution of NORM have been limited by poor statistical representation. In addition, the fate of NORM in the environment has not been fully defined, and few human health risk assessment have been conducted. Both the petroleum industry and regulators are becoming increasingly concerned about the presence of NORM. At present, most existing federal environmental regulations do not address oil and gas NORM, and only a few states have developed regulatory programs. Available data suggest that the occurrence of NORM (and associated health risks) is significant enough to warrant increased regulatory control. However, before these regulations can be developed, additional research is needed to (1) better characterize the occurrence and distribution of NORM throughout the industry, (2) quantify hazards posed by NORM to industry workers and the general public, and (3) develop effective waste treatment and minimization technologies that will lower the risk associated with NORM and reduce disposal costs.

Smith, K.P.

1992-12-01T23:59:59.000Z

486

Mass spectrometry of proteins of known mass Andrew D. Miranker*  

E-Print Network [OSTI]

deter- mination has two significant advantages. First, the mass accuracy under these conditions to the orifice of the mass analyzer. As a result, there is a local separation of charges at the tip

Miranker, Andrew

487

Isotope Production and Distribution Program`s Fiscal Year 1997 financial statement audit  

SciTech Connect (OSTI)

The Department of Energy Isotope Production and Distribution Program mission is to serve the national need for a reliable supply of isotope products and services for medicine, industry and research. The program produces and sells hundreds of stable and radioactive isotopes that are widely utilized by domestic and international customers. Isotopes are produced only where there is no U.S. private sector capability or other production capacity is insufficient to meet U.S. needs. The Department encourages private sector investment in new isotope production ventures and will sell or lease its existing facilities and inventories for commercial purposes. The Isotope Program reports to the Director of the Office of Nuclear Energy, Science and Technology. The Isotope Program operates under a revolving fund established by the Fiscal Year (FY) 1990 Energy and Water Appropriations Act and maintains financial viability by earning revenues from the sale of isotopes and services and through annual appropriations. The FY 1995 Energy and Water Appropriations Act modified predecessor acts to allow prices charged for Isotope Program products and services to be based on production costs, market value, the needs of the research community, and other factors. Although the Isotope Program functions as a business, prices set for small-volume, high-cost isotopes that are needed for research purposes may not achieve full-cost recovery. As a result, isotopes produced by the Isotope Program for research and development are priced to provide a reasonable return to the U.S. Government without discouraging their use. Commercial isotopes are sold on a cost-recovery basis. Because of its pricing structure, when selecting isotopes for production, the Isotope Program must constantly balance current isotope demand, market conditions, and societal benefits with its determination to operate at the lowest possible cost to U.S. taxpayers. Thus, this report provides a financial analysis of this situation.

NONE

1998-03-27T23:59:59.000Z

488

Macro-microscopic mass formulae and nuclear mass predictions  

E-Print Network [OSTI]

and alpha [5] processes in taking into account the shell effects, the proximity energy and the nuclear de aiming at reproducing the nuclear binding energy and then the nuclear mass contain the usual vol- umeMacro-microscopic mass formulae and nuclear mass predictions G. Royer, M. Guilbaud, A. Onillon

Boyer, Edmond

489

Isotopic Scaling and the Symmetry Energy in Spectator Fragmentation  

E-Print Network [OSTI]

Isotopic effects in the fragmentation of excited target residues following collisions of $^{12}$C on $^{112,124}$Sn at incident energies of 300 and 600 MeV per nucleon were studied with the INDRA 4$\\pi$ detector. The measured yield ratios for light particles and fragments with atomic number $Z \\leq$ 5 obey the exponential law of isotopic scaling. The deduced scaling parameters decrease with increasing centrality to values as low as $\\alpha = 0.25 \\pm 0.02$ for the central event group at 600 MeV per nucleon. Symmetry term coefficients, deduced from these data within the statistical description of isotopic scaling, are near $\\gamma =$ 25 MeV for peripheral and $\\gamma <$ 10 MeV for central collisions.

Auger, G; Begemann-Blaich, M L; Bellaize, N; Bittiger, R; Bocage, F; Borderie, B; Bougault, R; Bouriquet, B; Charvet, J L; Chbihi, A; Dayras, R; Durand, D; Frankland, J D; Galíchet, E; Gourio, D; Guinet, D; Hudan, S; Imme, G; Lautesse, P; Lavaud, F; Legrain, R; López, O; Lynen, U; Müller, W F J; Nalpas, L; Orth, H; Plagnol, E; Raciti, G; Rosato, E; Saija, A; Schwarz, C; Seidel, W; Sfienti, C; Tamain, B; Trautmann, W; Trzcinski, A; Turzó, K; Vient, E; Vigilante, M; Volant, C; Zwieglinski, B; Botvina, A S; The INDRA Collaboration

2004-01-01T23:59:59.000Z

490

Rare Isotopes in Cosmic Explosions and Accelerators on Earth  

ScienceCinema (OSTI)

Rare isotopes are nature?s stepping stones to produce the heavy elements, and they are produced in large quantities in stellar explosions. Despite their fleeting existence, they shape the composition of the universe and the observable features of stellar explosions. The challenge for nuclear science is to produce and study the very same rare isotopes so as to understand the origin of the elements and a range of astronomical observations. I will review the progress that has been made to date in astronomy and nuclear physics, and the prospects of finally addressing many of the outstanding issues with the future Facility for Rare Isotope Beams (FRIB), which DOE will build at Michigan State University.

Hendrik Schatz

2010-01-08T23:59:59.000Z

491

High-Resolution Triple Resonance Autoionization of Uranium Isotopes  

SciTech Connect (OSTI)

The near-threshold autoionization (AI) spectrum of uranium has been investigated by triple-resonance excitation with single-mode continuous lasers. Spectra were recorded over the first {approx}30 cm-1 above the first ionization limit at a resolution of 3x10-4 cm 1 using intermediate states with different J values (6, 7, 8) to assign AI level total angular momentum JAI = 5 to 9. Resonances with widths ranging from 8 MHz to 30 GHz were observed; the strongest ones have JAI = 9 and widths of {approx} 60 MHz. Hyperfine structures for 235U and isotope shifts for 234,235U have been measured in the two intermediate levels and in the final AI level for the most favorable excitation path. These measurements were performed using aqueous samples containing sub-milligram quantities of uranium at natural isotopic abundances, indicating the potential of this approach for trace isotope ratio determinations.

Schumann, Philipp G.; Wendt, K; Bushaw, Bruce A.

2005-11-01T23:59:59.000Z

492

Simple, rapid method for the preparation of isotopically labeled formaldehyde  

DOE Patents [OSTI]

Isotopically labeled formaldehyde (*C.sup..sctn.H.sub.2O) is prepared from labeled methyl iodide (*C.sup..sctn.H.sub.3I) by reaction with an oxygen nucleophile having a pendant leaving group. The mild and efficient reaction conditions result in good yields of *C.sup..sctn.H.sub.2O with little or no *C isotopic dilution. The simple, efficient production of .sup.11CH.sub.2O is described. The use of the .sup.11CH.sub.2O for the formation of positron emission tomography tracer compounds is described. The reaction can be incorporated into automated equipment available to radiochemistry laboratories. The isotopically labeled formaldehyde can be used in a variety of reactions to provide radiotracer compounds for imaging studies as well as for scintillation counting and autoradiography.

Hooker, Jacob Matthew (Port Jefferson, NY); Schonberger, Matthias (Mains, DE); Schieferstein, Hanno (Aabergen, DE); Fowler, Joanna S. (Bellport, NY)

2011-10-04T23:59:59.000Z

493

Effects of mass loss for highly-irradiated giant planets  

E-Print Network [OSTI]

We present calculations for the evolution and surviving mass of highly-irradiated extrasolar giant planets (EGPs) at orbital semimajor axes ranging from 0.023 to 0.057 AU using a generalized scaled theory for mass loss, together with new surface-condition grids for hot EGPs and a consistent treatment of tidal truncation. Theoretical estimates for the rate of energy-limited hydrogen escape from giant-planet atmospheres differ by two orders of magnitude, when one holds planetary mass, composition, and irradiation constant. Baraffe et al. (2004, A&A 419, L13-L16) predict the highest rate, based on the theory of Lammer et al. (2003, Astrophys. J. 598, L121-L124). Scaling the theory of Watson et al. (1981, Icarus 48, 150-166) to parameters for a highly-irradiated exoplanet, we find an escape rate ~102 lower than Baraffe's. With the scaled Watson theory we find modest mass loss, occurring early in the history of a hot EGP. In this theory, mass loss including the effect of Roche-lobe overflow becomes significant primarily for masses below a Saturn mass, for semimajor axes = 0.023 AU. This contrasts with the Baraffe model, where hot EGPs are claimed to be remnants of much more massive bodies, originally several times Jupiter and still losing substantial mass fractions at present.

W. B. Hubbard; M. F. Hattori; A. Burrows; I. Hubeny; D. Sudarsky

2006-10-27T23:59:59.000Z

494

In-Situ Sampling and Characterization of Naturally Occurring Marine Methane Hydrate Using the D/V JOIDES Resolution  

SciTech Connect (OSTI)

Cooperative Agreement DE-FC26-01NT41329 between Joint Oceanographic Institutions and DOE-NETL was divided into two phases based on successive proposals and negotiated statements of work pertaining to activities to sample and characterize methane hydrates on ODP Leg 204 (Phase 1) and on IODP Expedition 311 (Phase 2). The Phase 1 Final Report was submitted to DOE-NETL in April 2004. This report is the Phase 2 Final Report to DOE-NETL. The primary objectives of Phase 2 were to sample and characterize methane hydrates using the systems and capabilities of the D/V JOIDES Resolution during IODP Expedition 311, to enable scientists the opportunity to establish the mass and distribution of naturally occurring gas and gas hydrate at all relevant spatial and temporal scales, and to contribute to the DOE methane hydrate research and development effort. The goal of the work was to provide expand