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1

Half-life and gamma abundance ratio measurements of Sm-153  

SciTech Connect (OSTI)

The measurement of the decay of 153Sm was observed by gamma spectrometry, liquid scintillation counting and gas proportional counting in an attempt to confirm the half life and gamma abundance ratios for this isotope. Recent changes in the published nuclear decay data indicate that historical literature values may be biased. The 153Sm was made by the neutron activation of ultrapure isotopically enriched 152Sm to create 153Sm. The decay measurements were made over a three week period and no other isotopes were detected during this time. The gamma abundance ratio for the 103 keV gamma was measured to be (27.9%) which is 4% lower than the published data. In addition, the half life was 1.9308 days, which is 0.34% lower than the published data.

Friese, Judah I.; Payne, Rosara F.; Greenwood, Lawrence R.; Soderquist, Chuck Z.; Garofoli, Stephanie J.

2009-11-02T23:59:59.000Z

2

nature biotechnology volume 27 number 12 december 2009 1 half-life for indications when an extended residence time in the cir-  

E-Print Network [OSTI]

and can complicate tight control over plasma Focus on synthetic biology This issue of Nature Biotechnology

Cai, Long

3

Half-Life of $^{14}$O  

E-Print Network [OSTI]

We have measured the half-life of $^{14}$O, a superallowed $(0^{+} \\to 0^{+})$ $\\beta$ decay isotope. The $^{14}$O was produced by the $^{12}$C($^{3}$He,n)$^{14}$O reaction using a carbon aerogel target. A low-energy ion beam of $^{14}$O was mass separated and implanted in a thin beryllium foil. The beta particles were counted with plastic scintillator detectors. We find $t_{1/2} = 70.696\\pm 0.052$ s. This result is $1.5\\sigma$ higher than an average value from six earlier experiments, but agrees more closely with the most recent previous measurement.

J. T. Burke; P. A. Vetter; S. J. Freedman; B. K. Fujikawa; W. T. Winter

2006-07-27T23:59:59.000Z

4

Half life for spontaneous fission of curium-245  

SciTech Connect (OSTI)

A sample of curium-245 of extremely high enrichment was obtained with an electromagnetic separator. The half-life for spontaneous fission was determined by measuring the rate of alpha decay. (AIP)

Druzhinin, A.A.; Polynov, V.N.; Vesnovskii, S.P.; Korochkin, A.M.; Lbov, A.A.; Nikitin, E.A.

1985-02-01T23:59:59.000Z

5

Determination of the half-life of /sup 243/ Cm  

SciTech Connect (OSTI)

The authors determine the half life of Cm 243 (T/sub alpha 243/) relative to the half-life of Cm 244 (whose value is known with high accuracy) from the molar ratios of the mixture of the nuclide studied with Cm 244 and the nuclides of plutonium, forming as a result of the alpha decay of curium nuclides. The results of the calculations of T/sub alpha 243/ based on the formula presented are shown. The random error for the average value of T/sub alpha 243/ is presented with a confidence probability of 0.95.

Timofeev, G.A.; Kalygin, V.V.; Privalova, P.A.

1986-10-01T23:59:59.000Z

6

Half-life for spontaneous fission of /sup 243/Cm  

SciTech Connect (OSTI)

A method is proposed for measuring the half-life for spontaneous fission of curium 243. Isotope separation and purification techniques are described and the isotope ratio of the purified target is given. The efficiency of fission fragment detection for solid state mica detectors was measured with a curium 244 standard. Results for the rate of spontaneous fission are tabulated.

Polynov, V.N.; Druzhinin, A.A.; Korochkin, A.M.; Nikitin, E.A.; Bochkarev, V.A.; Vyachin, V.N.; Lapin, V.G.; Maksimov, M.Yu.

1987-10-01T23:59:59.000Z

7

Half-life of {sup 151}Sm remeasured  

SciTech Connect (OSTI)

The half-life of {sup 151}Sm was redetermined and compared with literature values. A {sup 151}Sm{sub 2}O{sub 3} sample was produced by exposing {sup 150}Sm{sub 2}O{sub 3} to the high neutron flux of the heavy water research reactor at the China Institute of Atomic Energy (CIAE). The number of atoms and the activity of {sup 151}Sm in the sample were measured by thermal ionization mass spectrometry (TIMS) and liquid scintillation counting (LSC), respectively. The half-life of {sup 151}Sm determined in this work is 96.6 yr, with a standard uncertainty of 2.4 yr based on a quadratic summation of the uncertainty components from the measurements of the number of atoms and the activity of {sup 151}Sm.

He Ming; Shen Hongtao; Shi Guozhu; Yin Xinyi; Tian Weizhi; Jiang Shan [Department of Nuclear Physics, China Institute of Atomic Energy, Post Office Box 275-50, Beijing 102413 (China)

2009-12-15T23:59:59.000Z

8

Measurement of the Double Beta Decay Half-life of 130Te with the NEMO-3 Detector  

E-Print Network [OSTI]

This Letter reports results from the NEMO-3 experiment based on an exposure of 1275 days with 661g of 130Te in the form of enriched and natural tellurium foils. With this data set the double beta decay rate of 130Te is found to be non-zero with a significance of 7.7 standard deviations and the half-life is measured to be T1/2 = (7.0 +/- 0.9(stat) +/- 1.1(syst)) x 10^{20} yr. This represents the most precise measurement of this half-life yet published and the first real-time observation of this decay.

Arnold, R; Baker, J; Barabash, A S; Basharina-Freshville, A; Blondel, S; Bongrand, M; Broudin-Bay, G; Brudanin, V; Caffrey, A J; Chapon, A; Chauveau, E; Durand, D; Egorov, V; Flack, R; Garrido, X; Grozier, J; Guillon, B; Hubert, Ph; Jackson, C M; Jullian, S; Kauer, M; Klimenko, A; Kochetov, O; Konovalov, S I; Kovalenko, V; Lalanne, D; Lamhamdi, T; Lang, K; Liptak, Z; Lutter, G; Mamedov, F; Marquet, Ch; Martin-Albo, J; Mauger, F; Mott, J; Nachab, A; Nemchenok, I; Nguyen, C H; Nova, F; Novella, P; Ohsumi, H; Pahlka, R B; Perrot, F; Piquemal, F; Reyss, J L; Richards, B; Ricol, J S; Saakyan, R; Sarazin, X; Shitov, Yu; Simard, L; Šimkovic, F; Smolnikov, A; Söldner-Rembold, S; Štekl, I; Suhonen, J; Sutton, C S; Szklarz, G; Thomas, J; Timkin, V; Torre, S; Tretyak, V I; Umatov, V; Vála, L; Vanyushin, I; Vasiliev, V; Vorobel, V; Vylov, T; Zukauskas, A

2011-01-01T23:59:59.000Z

9

Can Environmental Factors Affect Half-Life in Beta-Decay? An Analysis  

E-Print Network [OSTI]

of the decaying radioactive nuclide, and even the distance between Earth and the Sun at the time of the half-life measurement. In this study we present evidence that the initial beliefs in the immutability of radioactive half-life (with the exception of a few...

Goodwin, John 1953-

2013-01-16T23:59:59.000Z

10

Measurement of the {sup 44}Ti half-life and its significance for supernova.  

SciTech Connect (OSTI)

In 1998, we reported the three-laboratory measurement of the {sup 44}Ti half-life which was determined relative to the well known value (5.2714 {+-} 0.0005 yr) of the {sup 60}Co half-life. We have continued the measurement at Argonne and Jerusalem and inclusion of data points for additional two years does not change our published value of 59.0 {+-} 0.6 yr.

Ahmad, I.; Greene, J. P.; Kutschera, W.; Paul, M.

1999-08-28T23:59:59.000Z

11

The 198Au beta-half-life in the metal Au revisited  

E-Print Network [OSTI]

The half-life of the beta-decay of 198Au has been measured for room temperature and 12 K. The resulting values of T(RT) = 2.684 +- 0.004 d and T(12 K) = 2.687 +- 0.005 d agree well within statistical uncertainties. An evidence for a temperature dependence of the half-life was not observed.

K. Fortak; R. Kunz; L. Gialanella; H. -W. Becker; J. Meijer; F. Strieder

2010-09-10T23:59:59.000Z

12

Precise half-life measurement of the superallowed beta(+) emitter (26)Si  

E-Print Network [OSTI]

We measured the half-life of the superallowed 0(+) -> 0(+) beta(+) emitter (26)Si to be 2245.3(7) ms. We used pure sources of (26)Si and employed a high-efficiency gas counter, whichwas sensitive to positrons from both this nuclide and its daughter...

Iacob, V. E.; Hardy, John C.; Banu, A.; Chen, L.; Golovko, V. V.; Goodwin, J.; Horvat, V.; Nica, N.; Park, H. I.; Trache, L.; Tribble, Robert E.

2010-01-01T23:59:59.000Z

13

Precise half-life measurement of the superallowed beta(+) emitter (10)C  

E-Print Network [OSTI]

The half-life of (10)C has been measured to be 19.310(4) s, a result with 0.02% precision, which is a factor of three improvement over the best previous result. Since (10)C is the lightest superallowed 0(+)-> 0(+) beta(+) emitter, its ft value has...

Iacob, V. E.; Hardy, John C.; Golovko, V.; Goodwin, J.; Nica, N.; Park, H. I.; Trache, L.; Tribble, Robert E.

2008-01-01T23:59:59.000Z

14

Precise half-life measurements for the superallowed beta(+) emitters Ar-34 and Cl-34  

E-Print Network [OSTI]

PHYSICAL REVIEW C 74, 055502 (2006) Precise half-life measurements for the superallowed ?+ emitters 34Ar and 34Cl V. E. Iacob,* J. C. Hardy, J. F. Brinkley, C. A. Gagliardi, V. E. Mayes, N. Nica, M. Sanchez-Vega, G. Tabacaru, L. Trache, and R. E... 15, 17 (2002). [5] J. C. Hardy et al., Nucl. Phys. A223, 157 (1974). 055502-7 V. E. IACOB et al. PHYSICAL REVIEW C 74, 055502 (2006) [6] V. E. Iacob, E. Mayes, J. C. Hardy, R. G. Neilson, M. Sanchez- Vega, A. Azhari, C. A. Gagliardi, L. Trache...

Iacob, V. E.; Hardy, John C.; Brinkley, J. F.; Gagliardi, Carl A.; Mayes, V. E.; Nica, N.; Sanchez-Vega, M.; Tabacaru, G.; Trache, L.; Tribble, Robert E.

2006-01-01T23:59:59.000Z

15

Lignin dynamics in arable soils as determined by 13C natural abundance.  

E-Print Network [OSTI]

??Lignin is the second most abundant polymer in nature after the polysaccharides cellulose and hemicellulose. It is a main component in plant cell walls, where… (more)

Hofmann, A

2009-01-01T23:59:59.000Z

16

Average and recommended half-life values for two neutrino double beta decay  

E-Print Network [OSTI]

All existing positive results on two neutrino double beta decay in different nuclei were analyzed. Using the procedure recommended by the Particle Data Group, weighted average values for half-lives of $^{48}$Ca, $^{76}$Ge, $^{82}$Se, $^{96}$Zr, $^{100}$Mo, $^{100}$Mo - $^{100}$Ru ($0^+_1$), $^{116}$Cd, $^{130}$Te, $^{136}$Xe, $^{150}$Nd, $^{150}$Nd - $^{150}$Sm ($0^+_1$) and $^{238}$U were obtained. Existing geochemical data were analyzed and recommended values for half-lives of $^{128}$Te, and $^{130}$Ba are proposed. Given the measured half-life values, nuclear matrix elements were calculated using latest (more reliable and precise) values for phase space factor. Finally, previous results (PRC 81 (2010) 035501) were up-dated and results for $^{136}$Xe were added.

A. S. Barabash

2015-01-21T23:59:59.000Z

17

Conversion of experimental half-life to effective electron neutrino mass in 0nubetabeta decay  

SciTech Connect (OSTI)

The Germanium Detector Array (GERDA) collaboration will be searching for neutrinoless double beta decay of {sup 76}Ge. As a result it will measure the half-life T{sub 1/2} of this rare process; or at least a new value for the lower limit for T{sub 1/2} will be derived. The sensitivity of the GERDA experiment on the effective electron neutrino mass depends on the theoretical value for the nuclear matrix element M and the kinematical phase space factor G.In this Brief Report we focus on existing difficulties in applying the dimensionless values of M calculated by various theoretical groups, which use different methods and parametrizations. The implicit radius dependencies in M and G are discussed. Resulting values of the neutrino mass are tabulated for various representative half-lives T{sub 1/2} representing the sensitivity of the various phases of the GERDA experiment.

Smolnikov, Anatoly; Grabmayr, Peter [Joint Institute for Nuclear Research, Dubna, Russia, and Institute for Nuclear Research of the Russian Academy of Sciences, Moscow (Russian Federation); Kepler Center for Astro and Particle Physics, Eberhard Karls Universitaet Tuebingen (Germany)

2010-02-15T23:59:59.000Z

18

Ecological half-life of 137Cs in fish from a stream contaminated by nuclear reactor effluents  

SciTech Connect (OSTI)

Radiocesium ({sup 137}Cs) concentrations were determined during 1974, 1981 and 1998 for seven species of fish inhabiting a stream (Steel Creek) contaminated by effluents from a nuclear reactor to examine the decline of this radionuclide in a natural ecosystem. Median {sup 137}Cs concentrations were highest in Micropterus salmoides (largemouth bass) during each year of the investigation (1974 = 6.67 Bq g{sup -1} dry wt. of whole body; 1981 = 3.72 Bq g{sup -1}; 1998 = 0.35 Bq g{sup -1}), but no patterns of differences were observed among Aphredoderus sayanus (pirate perch), Esox americanus (redfin pickerel), Lepomis auritus (redbreast sunfish), L. gulosus (warmouth), L. punctatus (spotted sunfish), and Notropis cummingsae (dusky shiner). Results demonstrated a rapid decline in {sup 137}Cs within fish from Steel Creek during the 24-year period. For example, {sup 137}Cs concentrations in all fish species declined significantly among years, even after accounting for radioactive decay. The observed percent declines in {sup 137}Cs concentrations of individual species were 3-4 times greater between 1974 and 1981 compared to that expected by physical decay alone, and 2-3 times greater during 1981-1998. Ecological half-lives (EHLs) of {sup 137}Cs in fish ranged from 4.43 years in A. sayanus to 6.53 years in L. gulosus. The EHL for {sup 137}Cs in all fish species combined was 5.54 years. Current levels of {sup 137}Cs in fish from Steel Creek (1.16 Bq g{sup -1} dry wt. of whole body to below detection limits) indicate that the consumption of fish from this ecosystem poses little risk to humans and sensitive wildlife species. These results demonstrate the importance of incorporating the concept of ecological half-life into determinations concerning the length and severity of potential risks associated with radiocontaminants.

Peles, J. [Pennsylvania State University, McKeesport; BryanJr, A. [Savannah River Ecology Lab; Garten Jr, Charles T [ORNL; Ribble, D. [Trinity University; Smith, M. [Savannah River Ecology Lab

2000-12-01T23:59:59.000Z

19

Precise measurement of the 222Rn half-life: a probe to monitor the stability of radioactivity  

E-Print Network [OSTI]

We give the results of a study on the 222Rn decay we performed in the Gran Sasso Laboratory (LNGS) by detecting the gamma rays from the radon progeny. The motivation was to monitor the stability of radioactivity measuring several times per year the half-life of a short lifetime (days) source instead of measuring over a long period the activity of a long lifetime (tens or hundreds of years) source. In particular, we give the reason of the large periodical fluctuations in the count rate of the gamma rays due to radon inside a closed canister which has been described in literature and which has been attributed to a possible influence of a component in the solar irradiation affecting the nuclear decay rates. We then provide the result of four half-life measurements we performed underground at LNGS in the period from May 2014 to January 2015 with radon diffused into olive oil. Briefly, we did not measure any change of the 222Rn half-life with a 8*10^-5 precision. Finally, we provide the most precise value for the 222Rn half-life: 3.82146(16){stat}(4){syst} days.

E. Bellotti; C. Broggini; G. Di Carlo; M. Laubenstein; R. Menegazzo

2015-01-30T23:59:59.000Z

20

EFFECTIVE HALF-LIFE OF CESIUM-137 IN VARIOUS ENVIRONMENTAL MEDIA AT THE SAVANNAH RIVER SITE  

SciTech Connect (OSTI)

During the operational history of the Savannah River Site (SRS), many different radionuclides have been released from site facilities into the SRS environment. However, only a relatively small number of pathways, most importantly {sup 137}Cs in fish and deer, have contributed significantly to doses and risks to the public. The “effective” half-lives (T{sub e}) of {sup 137}Cs (which include both physical decay and environmental dispersion) in Savannah River floodplain soil and vegetation and in fish and white-tailed deer from the SRS were estimated using long-term monitoring data. For 1974–2011, the T{sub e}s of {sup 137}Cs in Savannah River floodplain soil and vegetation were 17.0 years (95% CI = 14.2–19.9) and 13.4 years (95% CI = 10.8–16.0), respectively. These T{sub e}s were greater than in a previous study that used data collected only through 2005 as a likely result of changes in the flood regime of the Savannah River. Field analyses of {sup 137}Cs concentrations in deer collected during yearly controlled hunts at the SRS indicated an overall T{sub e} of 15.9 years (95% CI = 12.3–19.6) for 1965–2011; however, the T{sub e} for 1990–2011 was significantly shorter (11.8 years, 95% CI = 4.8–18.8) due to an increase in the rate of {sup 137}Cs removal. The shortest T{sub e}s were for fish in SRS streams and the Savannah River (3.5–9.0 years), where dilution and dispersal resulted in rapid {sup 137}Cs removal. Long-term data show that T{sub e}s are significantly shorter than the physical half-life of {sup 137}Cs in the SRS environment but that they can change over time. Therefore, it is desirable have a long period of record for calculating Tes and risky to extrapolate T{sub e}s beyond this period unless the processes governing {sup 137}Cs removal are clearly understood.

Jannik, T.; Paller, M.; Baker, R.

2013-12-12T23:59:59.000Z

Note: This page contains sample records for the topic "natural abundance half-life" 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

Near-optimum procedure for half-life measurement by high-resolution gamma-ray spectrometry  

SciTech Connect (OSTI)

A near-optimum procedure for using high-resolution /gamma/-ray spectrometry to measure the half-lives of appropriate /gamma/-ray- emitting-nuclides is presented. Among the important points of the procedure are the employment of the reference source method for implicit correction of pileup and deadtime losses; the use of full-energy peak-area ratios as the fundamental measured quantities; and continuous, high-rate data acquisition to obtain good results in a fraction of a half-life if desired. Equations are given for estimating the precision of the computed half-lives in terms of total measurement time, number of spectral acquisitions, and the precision of peak-area ratios. Results of /sup 169/Yb half-life measurements are given as an example of the procedure's application. 3 refs., 2 tabs.

Parker, J.L.

1989-01-01T23:59:59.000Z

22

Measurement of the Double-Beta Decay Half-life of {sup 136}Xe in KamLAND-Zen  

SciTech Connect (OSTI)

We present results from the KamLAND-Zen double-beta decay experiment based on an exposure of 77.6 days with 129 kg of {sup 136}Xe. The measured two-neutrino double-beta decay half-life of {sup 136}Xe is T{sup 2{nu}}{sub 1/2} = 2:38 {+-}#6; 0:02(stat)#6;{+-}0.14(syst)#2;x10{sup 21} yr, consistent with a recent measurement by EXO-200. We also obtain a lower limit for the neutrinoless double-beta decay half-life, T{sup 0{nu}}{sub 1/2} > 5.7 x#2; 10{sup 24} yr at 90% C.L.

KamLAND-Zen Collaboration; Gando, A.; Gando, Y.; Hanakago, H.; Ikeda, H.; Inoue, K.; Kato, R.; Koga, M.; Matsuda, S.; Mitsui, T.; Nakada, T.; Nakamura, K.; Obata, A.; Oki, A.; Ono, Y.; Shimizu, I.; Shirai, J.; Suzuki, A.; Takemoto, Y.; Tamae, K.; Ueshima, K.; Watanabe, H.; Xu, B. D.; Yamada, S.; Yoshida, H.; Kozlov, A.; Yoshida, S.; Banks, T. I.; Detwiler, J. A.; Freedman, S. J.; Fujikawa, B. K.; Han, K.; O'Donnell, T.; Berger, B. E.; Efremenko, Y.; Karwowski, H. J.; Markoff, D. M.; Tornow, W.; Enomoto, S.; Decowski, M. P.

2012-01-23T23:59:59.000Z

23

Measurement of the double beta decay half-life of Nd-150 and search for neutrinoless decay modes with the NEMO-3 detector  

E-Print Network [OSTI]

The half-life for two-neutrino double beta decay of Nd-150 has been measured with data taken by the NEMO 3 experiment at the Modane Underground Laboratory. The limits are also set on the half-life of different neutrinoless double beta decay of this isotope.

Nasim Fatemi-Ghomi

2009-05-11T23:59:59.000Z

24

Precise measurement of the 222Rn half-life: a probe to monitor the stability of radioactivity  

E-Print Network [OSTI]

We give the results of a study on the 222Rn decay we performed in the Gran Sasso Laboratory (LNGS) by detecting the gamma rays from the radon progeny. The motivation was to monitor the stability of radioactivity measuring several times per year the half-life of a short lifetime (days) source instead of measuring over a long period the activity of a long lifetime (tens or hundreds of years) source. In particular, we give the reason of the large periodical fluctuations in the count rate of the gamma rays due to radon inside a closed canister which has been described in literature and which has been attributed to a possible influence of a component in the solar irradiation affecting the nuclear decay rates. We then provide the result of four half-life measurements we performed underground at LNGS in the period from May 2014 to January 2015 with radon diffused into olive oil. Briefly, we did not measure any change of the 222Rn half-life with a 8*10^-5 precision. Finally, we provide the most precise value for the ...

Bellotti, E; Di Carlo, G; Laubenstein, M; Menegazzo, R

2015-01-01T23:59:59.000Z

25

The significance of using the Newcomb-Benford law as a test of nuclear half-life calculations  

E-Print Network [OSTI]

Half-life number sequences collected from nuclear data charts are found to obey the Newcomb-Benford law. Based on this fact, it has been suggested recently, that this law should be used to test the quality of nuclear decay models. In this paper we briefly recall how, when and why the Newcomb-Benford law can be observed in a set of numbers with a given probability distribution. We investigate the special case of nuclear half-lives, and show that the law provides no additional clue in understanding decay half-lives. Thus, it can play no significant role in testing nuclear decay theories.

Janos Farkas; Gyorgy Gyurky

2010-06-18T23:59:59.000Z

26

Seasonal abundance and nature of damage of insects attacking cultivated sunflowers  

E-Print Network [OSTI]

, the vacuum sampling and whole-plant sampling methods, respectively, were used to collect injurious insect species associated with cultivated sunflowers. Popula- tion data proved that the whole-plant sampling method was more effective for obtaining insects...SEASONAL ABUNDANCE AND NATURE OF DAMAGE OF INSECTS ATTACKING CULTIVATED SUNFLOWERS A Thesis by Ronnie Lee Phillips Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER...

Phillips, Ronnie Lee

1972-01-01T23:59:59.000Z

27

Measurement of the two neutrino double beta decay half-life of Zr-96 and search for associated neutrinoless processes with the NEMO-3 detector  

E-Print Network [OSTI]

Using 1221 days of data from the NEMO-3 detector, the measurement of Zr-96 2vbb decay half-life is [2.35 +/- 0.14(stat) +/- 0.19(syst)] x 10^19 yr. Different characteristics of the final state electrons have been studied, such as the energy sum, individual electron energy, and angular distribution. The 2v nuclear matrix element is extracted using the measured 2vbb half-life and is 0.049 +/- 0.003. A 90% CL limit is set on the 0vbb decay half-life of > 9.2 x 10^21 yr corresponding to a limit on the effective Majorana neutrino mass < 7.2 - 19.5 eV. Limits on other mechanisms of 0vbb decay have also been set.

Argyriades, J; Augier, C; Baker, J; Barabash, A S; Bongrand, M; Broudin-Bay, G; Brudanin, V B; Caffrey, A J; Chapon, A; Chauveau, E; Daraktchieva, Z; Durand, D; Egorov, V G; Fatemi-Ghomi, N; Flack, R; Freshville, A; Guillon, B; Hubert, Ph; Jullian, S; Kauer, M; King, S; Kochetov, O I; Konovalov, S I; Kovalenko, V E; Lalanne, D; Lang, K; Lemiere, Y; Lutter, G; Mamedov, F; Marquet, Ch; Martín-Albo, J; Mauger, F; Nachab, A; Nasteva, I; Nemchenok, I B; Nova, F; Novella, P; Ohsumi, H; Pahlka, R B; Perrot, F; Piquemal, F; Reyss, J L; Ricol, J S; Saakyan, R; Sarazin, X; Simard, L; Shitov, Yu A; Smolnikov, A A; Snow, S; Söldner-Rembold, S; Stekl, I; Sutton, C S; Szklarz, G; Thomas, J; Timkin, V V; Tretyak, V I; Tretyak, Vl I; Umatov, V I; Vàla, L; Vanyushin, I A; Vasiliev, V A; Vorobel, V; Vylov, Ts

2009-01-01T23:59:59.000Z

28

Time-dependent extinction rate and species abundance in a tangled-nature model of biological evolution  

E-Print Network [OSTI]

Time-dependent extinction rate and species abundance in a tangled-nature model of biological properties. The macrodynamics exhibit intermittent two-mode switching with a gradually decreasing extinction sense. The form of the species abundance curve compares well with observed func- tional forms. The model

Christensen, Kim

29

Determination of the half-life of the ground state of {sup 229}Th by using {sup 232}U and {sup 233}U decay series  

SciTech Connect (OSTI)

The half-life of the ground state of {sup 229}Th ({sup 229}Th{sup g}) has become an important factor in nuclear technology, for example, in the geological disposal of nuclear spent fuel. However, the values reported in two previous studies are not in agreement. This study reevaluates the half-life of {sup 229}Th{sup g} by using a simple and reliable method. The {sup 232}U/{sup 233}U activity ratio of a {sup 232,233}U sample was measured by high-resolution {alpha}-particle spectrometry. Next, the {sup 228}Th/{sup 229}Th{sup g} activity ratio of the Th sample, which was grown from the {sup 232,233}U sample, was also measured. The half-life of {sup 229}Th{sup g} was calculated from these activity ratios, the growth time, and the half-lives of {sup 232}U, {sup 233}U, and {sup 228}Th. From the results of these five measurements, the half-life of {sup 229}Th{sup g} is determined to be 7932 {+-} 55 yr at a confidence level of 2{sigma}.

Kikunaga, H. [Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0198 (Japan); Suzuki, T.; Nomura, M. [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8550 (Japan); Mitsugashira, T. [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Miyagi 980-8577 (Japan); Shinohara, A. [Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan)

2011-07-15T23:59:59.000Z

30

Measurement of the double-{beta} decay half-life of {sup 150}Nd and search for neutrinoless decay modes with the NEMO-3 detector  

SciTech Connect (OSTI)

The half-life for double-{beta} decay of {sup 150}Nd has been measured by the NEMO-3 experiment at the Modane Underground Laboratory. Using 924.7 days of data recorded with 36.55 g of {sup 150}Nd, we measured the half-life for 2{nu}{beta}{beta} decay to be T{sub 1/2}{sup 2{nu}}=(9.11{sub -0.22}{sup +0.25}(stat.){+-}0.63(syst.))x10{sup 18} yr. The observed limit on the half-life for neutrinoless double-{beta} decay is found to be T{sub 1/2}{sup 0{nu}}>1.8x10{sup 22} yr at 90% confidence level. This translates into a limit on the effective Majorana neutrino mass of <4.0-6.3 eV if the nuclear deformation is taken into account. We also set limits on models involving Majoron emission, right-handed currents, and transitions to excited states.

Argyriades, J.; Augier, C.; Bongrand, M.; Jullian, S.; Lalanne, D.; Sarazin, X.; Simard, L.; Szklarz, G. [LAL, Universite Paris-Sud 11, CNRS/IN2P3, Orsay (France); Arnold, R. [IPHC, Universite de Strasbourg, CNRS/IN2P3, F-67037 Strasbourg (France); Baker, J.; Caffrey, A. J. [INL, Idaho Falls, Idaho 83415 (United States); Barabash, A. S.; Konovalov, S. I.; Umatov, V.; Vanyushin, I. [Institute of Theoretical and Experimental Physics, RU-117259 Moscow (Russian Federation); Basharina-Freshville, A.; Daraktchieva, Z.; Flack, R.; Kauer, M.; King, S. [University College London, WC1E 6BT London (United Kingdom)] (and others)

2009-09-15T23:59:59.000Z

31

Measurement of the half-life of the T=$\\frac{1}{2}$ mirror decay of $^{19}$Ne and its implication on physics beyond the standard model  

E-Print Network [OSTI]

The $\\frac{1}{2}^+ \\rightarrow \\frac{1}{2}^+$ superallowed mixed mirror decay of $^{19}$Ne to $^{19}$F is excellently suited for high precision studies of the weak interaction. However, there is some disagreement on the value of the half-life. In a new measurement we have determined this quantity to be $T_{1/2}$ = $17.2832 \\pm 0.0051_{(stat)}$ $\\pm 0.0066_{(sys)}$ s, which differs from the previous world average by 3 standard deviations. The impact of this measurement on limits for physics beyond the standard model such as the presence of tensor currents is discussed.

L. J. Broussard; H. O. Back; M. S. Boswell; A. S. Crowell; P. Dendooven; G. S. Giri; C. R. Howell; M. F. Kidd; K. Jungmann; W. L. Kruithof; A. Mol; C. J. G. Onderwater; R. W. Pattie Jr.; P. D. Shidling; M. Sohani; D. J. van der Hoek; A. Rogachevskiy; E. Traykov; O. O. Versolato; L. Willmann; H. W. Wilschut; A. R. Young

2014-05-28T23:59:59.000Z

32

NATURE MATERIALS | VOL 13 | MARCH 2014 | www.nature.com/naturematerials 233 hotovoltaic devices --which convert abundant, free solar  

E-Print Network [OSTI]

- and downconversion11 , technologies that, like the multi-junction strategy, offer a roadmap beyond the Shockley dot photovoltaics Xinzheng Lan1,2 , Silvia Masala1,3 and Edward H. Sargent1 * The solar -- which convert abundant, free solar radiation into electric power -- are increasingly required to offer

33

Natural Gas: From Shortages to Abundance in the U.S.  

E-Print Network [OSTI]

The recent dramatic and largely unanticipated growth in the current and expected future production of shale gas, and the related developments in the production of shale oil, have dramatically changed the energy future of the U.S. and potentially of the world compared to what experts were forecasting only a few years ago. These changes would not have been realized as quickly and efficiently absent deregulation of the wellhead price of natural gas, unbundling of gas supplies from pipeline transportation services, the associated development of efficient liquid markets for natural gas, and reforms to the licensing and regulation of prices for gas pipelines charge to move gas from where it is produced to where it is consumed. This economic platform supported the integration of technological advances in vertical drilling, downhole telemetry, horizontal drilling, monitoring and control of deep drilling equipment, and hydraulic fracturing to exploit economically shale gas deposits that were identified long ago, but considered to be uneconomical until recently. I. Natural Gas Wellhead Price and Pipeline Regulation Federal regulation of the natural gas industry began with the Natural Gas Act of 1938 (NGA). The NGA gave the Federal Power Commission (FPC), later the Federal Energy Regulatory Commission (FERC), the authority to license the construction and expansion of new interstate natural gas pipelines, to ensure that they are operated safely, and to regulate the prices 1

Paul L. Joskow

2012-01-01T23:59:59.000Z

34

Natural Gas Development and Grassland Songbird Abundance in Southwestern Saskatchewan: The Impact of Gas Wells and Cumulative Disturbance .  

E-Print Network [OSTI]

??The quantity and quality of remaining grasslands in southwestern Saskatchewan, Canada, are threatened by expansion of natural gas development. The number of natural gas wells… (more)

Bogard, Holly Jayne Kalyn

2011-01-01T23:59:59.000Z

35

NATURE CHEMISTRY | VOL 3 | OCTOBER 2011 | www.nature.com/naturechemistry 763 unlight is the most abundant source of energy we have at our  

E-Print Network [OSTI]

will be used for solar fuel production, to direct and regulate excitation energy flow using molecular. Researchers must learn how to capture, transfer and store solar energy effectively because it is forecast abundant source of energy we have at our disposal. It plays the deciding role in net primary production

Fleming, Graham R.

36

Natural variations of /sup 13/C abundance in coal and bitumen as a tool to monitor co-processing  

SciTech Connect (OSTI)

The use of coal to facilitate the generation of transportation grade fuel bitumen, heavy oil for petroleum resids is a topic of continuing research. In order to optimize the upgrading process one needs to know in what proportion each feedstock contributes to each product fraction. Conventional analytical methods are neither able to distinguish the contribution from either feedstock in the synthetic products, nor measure the subtle changes in product character in response to differing process conditions. The inherent difference in the /sup 13/C//sup 12/C ratio between most coals and bitumens can be utilized as an isotopic tracer to assess the efficacy of co-processing. For example Vesta coal and Athabasca bitumen have sufficiently distinct /sup 13/C//sup 12/C ratios that the measured /sup 13/C//sup 12/C of any product will accurately reflect the proportion of feed incorporated into the product. From the elemental analysis and the /sup 13/C//sup 12/C ratio of the feedstock and products one can calculate the amount of carbon derived from coal (CDC) in each product fraction. Analogously the amount of bitumen derived carbon (BDC) can also be independently calculated. In this study the natural variation in /sup 13/C concentration was utilized as an isotopic tracer to evaluate co-processing efficiency of a one litre stirred autoclave under differing process conditions. Process variables examined were coal concentration, several iron based catalysts (Fe/sub 2/O/sub 3/; Fe/sub 2/O/sub 3/ impregnated with TiO/sub 2/, SnO/sub 2/, or ZnO and a sludge obtained from a nickel refinery) and temperature.

Muehlenbachs, K.; Steer, J.G. (Dept. of Geology, Univ. of Alberta, Edmonton Alberta, T6G 2E3 (CA)); Hogg, A. (Dept. of Chemistry, Univ. of Alberta, Edmonton Alberta T6G 2E3 (CA)); Ohuchi, T.; Beaulieu, G. (Coal Dept., Alberta Research Council, Devon, Alberta T0C 1E0 (CA))

1988-06-01T23:59:59.000Z

37

Natural variations of sup 13 C abundance in coal and bitumen as a tool to monitor coprocessing  

SciTech Connect (OSTI)

The use of coal to facilitate the generation of transportation grade fuel from bitumen, heavy oil or petroleum resids is a topic of continuing research. In order to optimize the upgrading process one needs to know in what proportion each feedstock contributes to each product fraction. Conventional analytical methods are neither able to distinguish the contribution from either feedstock in the synthetic products, nor measure the subtle changes in product character in response to differing process conditions. The inherent difference in the {sup 13}C/{sup 12}C ratio between most coals and bitumen can be utilized as an isotopic tracer to assess the efficacy of coprocessing. For example Vesta coal and Athabasca bitumen have sufficiently distinct {sup 13}C/{sup 12}C ratios that the measured {sup 13}C/{sup 12}C of any product will accurately reflect the proportion of feed incorporated into the product. From the elemental analysis and the {sup 13}C/{sup 12}C ratio of the feedstock and products one can calculate the amount of carbon derived from coal (CDC) in each product fraction. Analogously the amount of bitumen derived carbon (BDC) can also be independently calculated. In this study the natural variation in {sup 13}C concentration was utilized as an isotopic tracer to evaluate coprocessing efficiency of a one liter stirred autoclave under differing process conditions. Process variables examined were coal concentration, several iron based catalysts (Fe{sub 2}O{sub 3}; Fe{sub 2}O{sub 3} impregnated with TiO{sub 2}, SnO{sub 2}, or ZnO and a sludge obtained from a nickel refinery) and temperature.

Muehlenbachs, K.; Steer, J.G.; Hogg, A.; Ohuchi, T.; Beaulieu, G. (Univ. of Alberta, Edmonton (Canada))

1988-01-01T23:59:59.000Z

38

Metrological Determination of Natural Radioactive Isotopes {sup 226}Ra, {sup 228}Ra and {sup 210}Pb by Means of Ge Detector  

SciTech Connect (OSTI)

A metrological method to determine the activity per mass unity (activity concentration) of {sup 226}Ra and {sup 210}Pb ({sup 238}U decay series) and {sup 228}Ra ({sup 232}Th series) by gamma-ray spectrometers based on hyper-pure coaxial germanium detector was developed. In the soil the {sup 22}Ra (half-life = 1600 years) exhibits the same level of radioactivity as {sup 238}U (half-life 4.5x10{sup 9} years) because of a natural phenomenon called secular equilibrium. {sup 226}Ra decays into {sup 222}Rn (half-life = 3.8 days), a radioactive inert gas. After several days, the {sup 222}Rn naturally decays to {sup 218}Po (half-life = 3 minutes), where finally {sup 210}Pb (half-life = 22 years) is produced. The metrological capability of high-resolution gamma-ray spectrometry for naturally occurring radionuclides at environmental levels is showed, with emphasis on the use of 2 mL standard sources volume in a glass ampoule. Source preparation and calibration procedures are described. Radionuclide standards in an activity range of 10 to 250 Bq/g were produced which can be applied in a variety of environmental sample analysis (water, plant material, sediment, etc.). Uncertainties for {sup 226}Ra and {sup 210}Pb around 3% (k = 1) were obtained.

Almeida, Maria Candida M. de; Delgado, Jose U.; Poledna, Roberto; Oliveira, Estela Maria de; Silva, Ronaldo L. da [Laboratorio Nacional de Metrologia das Radiacoes Ionizantes, Instituto de Radioprotecao e Dosimetria, Comissao Nacional de Energia Nuclear(SEMRA/LNMRI/IRD/CNEN) Av. Salvador Allende s/n, Recreio, Rio de Janeiro, CEP 22780-160, RJ (Brazil)

2008-08-07T23:59:59.000Z

39

Production of 239 Pu from a natural Uranium disk and "hot" rock using a neutron howitzer  

E-Print Network [OSTI]

A neutron howitzer was used to produce 239Np from the targets of natural U and a hot rock. An intrinsic Germanium detector enabled the observations of the gamma rays in the decay of 239Np and a determination of its half life of 2.3 days. This shows that 239Pu had been produced in both targets

Joseph Steiner; Aaron Anderson; Michael De Marco

2008-05-23T23:59:59.000Z

40

Helioseismology and Solar Abundances  

E-Print Network [OSTI]

Helioseismology has allowed us to study the structure of the Sun in unprecedented detail. One of the triumphs of the theory of stellar evolution was that helioseismic studies had shown that the structure of solar models is very similar to that of the Sun. However, this agreement has been spoiled by recent revisions of the solar heavy-element abundances. Heavy element abundances determine the opacity of the stellar material and hence, are an important input to stellar model calculations. The models with the new, low abundances do not satisfy helioseismic constraints. We review here how heavy-element abundances affect solar models, how these models are tested with helioseismology, and the impact of the new abundances on standard solar models. We also discuss the attempts made to improve the agreement of the low-abundance models with the Sun and discuss how helioseismology is being used to determine the solar heavy-element abundance. A review of current literature shows that attempts to improve agreement between solar models with low heavy-element abundances and seismic inference have been unsuccessful so far. The low-metallicity models that have the least disagreement with seismic data require changing all input physics to stellar models beyond their acceptable ranges. Seismic determinations of the solar heavy-element abundance yield results that are consistent with the older, higher values of the solar abundance, and hence, no major changes to the inputs to solar models are required to make higher-metallicity solar models consistent with helioseismic data.

Sarbani Basu; H. M. Antia

2007-11-28T23:59:59.000Z

Note: This page contains sample records for the topic "natural abundance half-life" 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

The Solar Argon Abundance  

E-Print Network [OSTI]

The solar argon abundance cannot be directly derived by spectroscopic observations of the solar photosphere. The solar Ar abundance is evaluated from solar wind measurements, nucleosynthetic arguments, observations of B stars, HII regions, planetary nebulae, and noble gas abundances measured in Jupiter's atmosphere. These data lead to a recommended argon abundance of N(Ar) = 91,200(+/-)23,700 (on a scale where Si = 10^6 atoms). The recommended abundance for the solar photosphere (on a scale where log N(H) = 12) is A(Ar)photo = 6.50(+/-)0.10, and taking element settling into account, the solar system (protosolar) abundance is A(Ar)solsys = 6.57(+/-)0.10.

Katharina Lodders

2007-10-24T23:59:59.000Z

42

Element Abundances at High Redshifts  

E-Print Network [OSTI]

I review measurements of element abundances in different components of the high redshift universe, including the Lyman alpha forest, damped Lyman alpha systems, and Lyman break galaxies. Although progress is being made in all three areas, recent work has also produced some surprises and shown that established ideas about the nature of the damped Lyman alpha systems in particular may be too simplistic. Overall, our knowledge of metal abundances at high z is still very sketchy. Most significantly, there seems to be an order of magnitude shortfall in the comoving density of metals which have been measured up to now compared with those produced by the star formation activity seen in Lyman break galaxies. At least some of the missing metals are likely to be in hot gas in galactic halos and proto-clusters.

Max Pettini

1999-02-11T23:59:59.000Z

43

Earth-Abundant Materials  

Broader source: Energy.gov [DOE]

DOE funds research into Earth-abundant materials for thin-film solar applications in response to the issue of materials scarcity surrounding other photovoltaic (PV) technologies. Below are a list...

44

Measuring solar abundances  

SciTech Connect (OSTI)

This is the rapporteur paper of Working Group 2 on Measuring Solar Abundances. The working group presented and discussed the different observations and methods for obtaining the elemental and isotopic composition of the Sun, and critically reviewed their results and the accuracies thereof. Furthermore, a few important yet unanswered questions were identified, and the potential of future missions to provide answers was assessed.

Reisenfeld, D. B. (Daniel B.); Von Steiger, R. (Rudolf); Vial, J.-C. (Jean-Claude); Bochsler, P.; Chaussidon, M.; Cohen, C. M. S.; Fleck, B.; Heber, V. S.; Wiens, R. C. (Roger C.)

2001-01-01T23:59:59.000Z

45

Constraining solar abundances using helioseismology  

E-Print Network [OSTI]

Recent analyses of solar photospheric abundances suggest that the oxygen abundance in the solar atmosphere needs to be revised downwards. In this study we investigate the consequence of this revision on helioseismic analyses of the depth of the solar convection zone and the helium abundance in the solar envelope and find no significant effect. We also find that the revised abundances along with the current OPAL opacity tables are not consistent with seismic data. A significant upward revision of the opacity tables is required to make solar models with lower oxygen abundance consistent with seismic observations.

Sarbani Basu; H. M. Antia

2004-03-19T23:59:59.000Z

46

Determining solar abundances using helioseismology  

E-Print Network [OSTI]

The recent downward revision of solar photospheric abundances of Oxygen and other heavy elements has resulted in serious discrepancies between solar models and solar structure as determined through helioseismology. In this work we investigate the possibility of determining the solar heavy-element abundance without reference to spectroscopy by using helioseismic data. Using the dimensionless sound-speed derivative in the solar convection zone, we find that the heavy element abundance, Z, of 0.0172 +/- 0.002, which is closer to the older, higher value of the abundances.

H. M. Antia; Sarbani Basu

2006-02-28T23:59:59.000Z

47

Literature survey of isotopic abundance data for 1987-1989  

SciTech Connect (OSTI)

I have compiled all of the data on isotopic abundance measurements and their variation in nature for the time period since the last General Assembly. Most of the data deals with the variations in the abundances as given by per mil deviations from some standard. As such, they are not of major interest to the Atomic Weights Commission. However, there were some measurements which are of general interest in this list.

Holden, N.E. (Brookhaven National Lab., Upton, NY (USA))

1989-08-09T23:59:59.000Z

48

Chemical Evolution of CNO abundances  

E-Print Network [OSTI]

New low and intermediate star yields calculated by Buell (1997) are evaluated by using them in a Galactic Chemical Evolution model. We analyze their effects on CNO elemental abundances

M. Gavilan; M. Molla

2003-02-05T23:59:59.000Z

49

Kinetics simulation for natural gas conversion to unsaturated C? hydrocarbons.  

E-Print Network [OSTI]

??Natural gas resource is abundant and can be found throughout the world. But most natural gas reserves are at remote sites and considered stranded because… (more)

Yang, Li

2012-01-01T23:59:59.000Z

50

Iron abundance in HII regions  

E-Print Network [OSTI]

Optical CCD spectra are used to determine the Fe abundances at several positions inside seven bright Galactic HII regions. The observed [FeIII] line ratios are compared with the predictions of different sets of collision strengths and transition probabilities for this ion to select the atomic data providing the best fit to the observations. The values found for the Fe++ and Fe+ abundances, along with ionization correction factors for the contribution of Fe3+, obtained from available grids of photoionized models, imply that the Fe/O ratio in the ionized gas is between 2% and 30% of solar. The Fe abundances derived for each area are correlated both with the degree of ionization and the colour excess. A possible explanation is suggested, namely the presence of a population of small grains, probably originating from the fragmentation of larger grains. These small grains would release Fe atoms into the gas after the absorption of energetic photons; the small grains surviving this destruction process would be swept out of the ionized region by the action of radiation pressure or stellar winds. An indication of a further and more efficient destruction agent is given by the high Fe abundance derived for a position sampling the optical jet H399 in M20, where dust destruction due to shock waves has presumably taken place.

M. Rodriguez

2002-03-22T23:59:59.000Z

51

Primordial Lithium Abundance in Catalyzed Big Bang Nucleosynthesis  

E-Print Network [OSTI]

There exists a well known problem with the Li7+Be7 abundance predicted by standard big bang nucleosynthesis being larger than the value observed in population II stars. The catalysis of big bang nucleosynthesis by metastable, \\tau_X \\ge 10^3 sec, charged particles X^- is capable of suppressing the primordial Li7+Be7, abundance and making it consistent with the observations. We show that to produce the correct abundance, this mechanism of suppression places a requirement on the initial abundance of X^- at temperatures of 4\\times 10^8 K to be on the order of or larger than 0.02 per baryon, which is within the natural range of abundances in models with metastable electroweak-scale particles. The suppression of Li7+Be7, is triggered by the formation of (Be7X^-), compound nuclei, with fast depletion of their abundances by catalyzed proton reactions, and in some models by direct capture of X^- on Be7. The combination of Li7+Be7 and Li6 constraints favours the window of lifetimes, 1000s \\la tau_X \\leq 2000 s.

Chris Bird; Kristen Koopmans; Maxim Pospelov

2008-05-19T23:59:59.000Z

52

Natural Abundance 43Ca NMR Spectroscopy of Tobermorite and Jennite...  

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

which has limited our ability to understand the structure of, for example, Ca–silicate hydrate (C–S–H). 43Ca nuclear magnetic resonance (NMR) spectroscopy has...

53

Abundance measurements in stellar environments  

SciTech Connect (OSTI)

Most of what we know about stars, and systems of stars, is derived from the analysis of their electromagnetic radiation. This lesson is an attempt to describe to Physicists, without any Astrophysical background, the framework to understand the present status of abundance determination in stellar environments and its limit. These notes are dedicated to the recently passed, November 21, 2013, Prof. Dimitri Mihalas who spent his life confuting the 19th century positivist philosopher Auguste Comte who stated that we shall not at all be able to determine the chemical composition of stars.

Leone, F. [Università di Catania, Dipartimento di Fisica e Astronomia, Sezione Astrofisica, Via S. Sofia 78, 95123 Catania (Italy)

2014-05-09T23:59:59.000Z

54

Comparative analysis of spectra of the background of the proportional counter filled with Kr, enriched in Kr-78, and with Kr of natural content  

E-Print Network [OSTI]

The results of the experiment searching for 2K-capture with large low-background proportional counter are presented. The comparison of spectra of the background of the proportional counter filled with Kr enriched in $^{78}$Kr (8400 hr) and with natural Kr (3039 hr) is given. A new limit on the half-life of $^{78}$Kr with regard to 2K-capture, T$_{1/2}\\geq2.0\\cdot10^{21}$ yrs (95% C.L.) has been obtained.

Yu. M. Gavriljuk; V. N. Gavrin; A. M. Gangapshev; V. V. Kazalov; V. V. Kuzminov; S. I. Panasenko; S. S. Ratkevich

2007-11-16T23:59:59.000Z

55

Abundance Ratios in Early-Type Galaxies  

E-Print Network [OSTI]

Although evidence is accumulating that abundance ratios in galaxies are often non-solar, they are far from understood. I resume the current evidence for non-solar abundance ratios, supplementing the recent review by Worthey (1998) with some new results. It appears that the Mg/Fe abundance ratio only depends on the mass of the galaxy, not on the formation time-scale. For massive galaxies [Mg/Fe] > 0, while small galaxies show solar abundance ratios. Information about abundances of other element is scarce, but new evidence is given that [Ca/Fe] is solar, or slightly lower than solar, contrary to what is expected for an alpha-element.

Reynier Peletier

1999-04-21T23:59:59.000Z

56

The discrepancy between solar abundances and helioseismology  

E-Print Network [OSTI]

There have been recent downward revisions of the solar photospheric abundances of Oxygen and other heavy elements. These revised abundances along with OPAL opacities are not consistent with seismic constraints. In this work we show that the recently released OP opacity tables cannot resolve this discrepancy either. While the revision in opacities does not seem to resolve this conflict, an upward revision of Neon abundance in solar photosphere offers a possible solution to this problem.

H. M. Antia; Sarbani Basu

2005-01-07T23:59:59.000Z

57

RELATIVE CHIRAL ABUNDANCES OF CARBON NANOTUBES DETERMINED BYRELATIVE CHIRAL ABUNDANCES OF CARBON NANOTUBES DETERMINED BYRELATIVE CHIRAL ABUNDANCES OF CARBON NANOTUBES DETERMINED BYRELATIVE CHIRAL ABUNDANCES OF CARBON NANOTUBES DETERMINED BY RESONANT RAMAN  

E-Print Network [OSTI]

RELATIVE CHIRAL ABUNDANCES OF CARBON NANOTUBES DETERMINED BYRELATIVE CHIRAL ABUNDANCES OF CARBON NANOTUBES DETERMINED BYRELATIVE CHIRAL ABUNDANCES OF CARBON NANOTUBES DETERMINED BYRELATIVE CHIRAL ABUNDANCES OF CARBON NANOTUBES DETERMINED BY RESONANT RAMAN SPECTROSCOPY USING A TUNABLE DYE LASERRESONANT

Mellor-Crummey, John

58

Average and recommended half-life values for two neutrino double beta decay: Upgrade-2013  

SciTech Connect (OSTI)

All existing positive results on two neutrino double beta decay in different nuclei were analyzed. Using the procedure recommended by the Particle Data Group, weighted average values for half-lives of {sup 48}Ca, {sup 76}Ge, {sup 82}Se, {sup 96}Zr, {sup 100}Mo, {sup 100}Mo?{sup 100}Ru (0{sub 1}{sup +}), {sup 116}Cd, {sup 130}Te, {sup 136}Xe, {sup 150}Nd, {sup 150}Nd?{sup 150}Sm (0{sub 1}{sup +}) and {sup 238}U were obtained. Existing geochemical data were analyzed and recommended values for half-lives of {sup 128}Te and {sup 130}Ba are proposed. I recommend the use of these results as the most currently reliable values for half-lives.

Barabash, A. S. [Institute of Theoretical and Experimental Physics, B. Cheremushkinskaya 25, 117218 Moscow (Russian Federation)

2013-12-30T23:59:59.000Z

59

Method of separating short half-life radionuclides from a mixture of radionuclides  

DOE Patents [OSTI]

The present invention is a method of removing an impurity of plutonium, lead or a combination thereof from a mixture of radionuclides that contains the impurity and at least one parent radionuclide. The method has the steps of (a) insuring that the mixture is a hydrochloric acid mixture; (b) oxidizing the acidic mixture and specifically oxidizing the impurity to its highest oxidation state; and (c) passing the oxidized mixture through a chloride form anion exchange column whereupon the oxidized impurity absorbs to the chloride form anion exchange column and the {sup 229}Th or {sup 227}Ac ``cow`` radionuclide passes through the chloride form anion exchange column. The plutonium is removed for the purpose of obtaining other alpha emitting radionuclides in a highly purified form suitable for medical therapy. In addition to plutonium, lead, iron, cobalt, copper, uranium, and other metallic cations that form chloride anionic complexes that may be present in the mixture are removed from the mixture on the chloride form anion exchange column. 8 figs.

Bray, L.A.; Ryan, J.L.

1999-03-23T23:59:59.000Z

60

, 227 240 . Half-life Radioactive decay Reaction with 2200 m/s neutrons  

E-Print Network [OSTI]

. 700-800 U2N3 UN2 . 1.2.5. 1.5 . , . UF4 UF6 UO2 HF . UO3 + 4HF Boils at 1 atm UF6 Black ~1427 8.95 UF4 Green 1036 1457 6.70 U4F17 Black 430 Disp. 6.94 U2F9 390 Disp. 7.06 UF5 White 348 Disp. 6.45 UF6 Colorless 64.05 56.54 5.06 UCl3 Olive green 837 1657 5.51 UCl4 Dark

Hong, Deog Ki

Note: This page contains sample records for the topic "natural abundance half-life" 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

Prolonged lipoprotein half-life: effect on oxidative stability and physical features of lipoprotein particles  

E-Print Network [OSTI]

Atherosclerotic cardiovascular disease (ASCVD) is responsible for two out of the three leading causes of death in the United States. Oxidatively modified apolipoprotein B-containing lipoprotein (apoB-LPs) are known to contribute to atherosclerotic...

Simeral, Stephanie Bianco

2002-01-01T23:59:59.000Z

62

Half-life measurements of isomeric states populated in projectile fragmentation  

SciTech Connect (OSTI)

The half-lives of excited isomeric states observed in {sup 195}Au, {sup 201}Tl and {sup 215}Rn are reported for the first time. Delayed {gamma}-rays were correlated with nuclei produced in the projectile fragmentation of relativistic {sup 238}U ions, unambiguously identified in terms of their atomic number (Z) and mass-to-charge ratio (A/Q) after traversing an in-flight separator. The observation of a long-lived isomeric state in {sup 195}Au with t{sub 1/2} = 16{sub -4}{sup +8}{mu}s is presented. Two shorter-lived isomeric states were detected in {sup 201}Tl and {sup 215}Rn with t{sub 1/2} = 95{sub -21}{sup +39} and 57{sub -12}{sup +21} ns respectively. In total 24 isomeric states were identified in different nuclei from Pt to Rn (A {approx} 200) during the current study, the majority of which were previously reported. The wealth of spectroscopic data provides the opportunity to determine the isomeric ratios over a wide range of Z, A and angular momentum (I h) of the reaction products. In particular, high-spin states with I Greater-Than-Or-Equivalent-To 18 h provide a robust test of theoretical models of fragmentation.

Bowry, M.; Podolay, Zs. [Department of Physics, University of Surrey, Guildford, GU2 7XH (United Kingdom)

2012-10-20T23:59:59.000Z

63

SIMPLIFIED PROCEDURE FOR CERTAIN USERS OF SEALED SOURCES, SHORT HALF-LIFE MATERIALS,  

E-Print Network [OSTI]

authority with a minimum of: (1) a certification that no residual radioactive contamination attributable, AND SMALL QUANTITIES A large number of users of radioactive materials may use a simplified procedure that qualify for simplified decommissioning procedures are those where radioactive materials have been used

64

Methods of separating short half-life radionuclides from a mixture of radionuclides  

DOE Patents [OSTI]

The present invention is a method of obtaining a radionuclide product selected from the group consisting of .sup.223 Ra and .sup.225 Ac, from a radionuclide "cow" of .sup.227 Ac or .sup.229 Th respectively. The method comprises the steps of a) permitting ingrowth of at least one radionuclide daughter from said radionuclide "cow" forming an ingrown mixture; b) insuring that the ingrown mixture is a nitric acid ingrown mixture; c) passing the nitric acid ingrown mixture through a first nitrate form ion exchange column which permits separating the "cow" from at least one radionuclide daughter; d) insuring that the at least one radionuclide daughter contains the radionuclide product; e) passing the at least one radionuclide daughter through a second ion exchange column and separating the at least one radionuclide daughter from the radionuclide product and f) recycling the at least one radionuclide daughter by adding it to the "cow". In one embodiment the radionuclide "cow" is the .sup.227 Ac, the at least one daughter radionuclide is a .sup.227 Th and the product radionuclide is the .sup.223 Ra and the first nitrate form ion exchange column passes the .sup.227 Ac and retains the .sup.227 Th. In another embodiment the radionuclide "cow"is the .sup.229 Th, the at least one daughter radionuclide is a .sup.225 Ra and said product radionuclide is the .sup.225 Ac and the .sup.225 Ac and nitrate form ion exchange column retains the .sup.229 Th and passes the .sup.225 Ra/Ac.

Bray, Lane A. (Richland, WA); Ryan, Jack L. (West Richland, WA)

1998-01-01T23:59:59.000Z

65

Methods of separating short half-life radionuclides from a mixture of radionuclides  

DOE Patents [OSTI]

The present invention is a method of obtaining a radionuclide product selected from the group consisting of {sup 223}Ra and {sup 225}Ac, from a radionuclide ``cow`` of {sup 227}Ac or {sup 229}Th respectively. The method comprises the steps of (a) permitting ingrowth of at least one radionuclide daughter from said radionuclide ``cow`` forming an ingrown mixture; (b) insuring that the ingrown mixture is a nitric acid ingrown mixture; (c) passing the nitric acid ingrown mixture through a first nitrate form ion exchange column which permits separating the ``cow`` from at least one radionuclide daughter; (d) insuring that the at least one radionuclide daughter contains the radionuclide product; (e) passing the at least one radionuclide daughter through a second ion exchange column and separating the at least one radionuclide daughter from the radionuclide product and (f) recycling the at least one radionuclide daughter by adding it to the ``cow``. In one embodiment the radionuclide ``cow`` is the {sup 227}Ac, the at least one daughter radionuclide is a {sup 227}Th and the product radionuclide is the {sup 223}Ra and the first nitrate form ion exchange column passes the {sup 227}Ac and retains the {sup 227}Th. In another embodiment the radionuclide ``cow`` is the {sup 229}Th, the at least one daughter radionuclide is a {sup 225}Ra and said product radionuclide is the {sup 225}Ac and the {sup 225}Ac and nitrate form ion exchange column retains the {sup 229}Th and passes the {sup 225}Ra/Ac. 8 figs.

Bray, L.A.; Ryan, J.L.

1998-09-15T23:59:59.000Z

66

Analysis of environmental influences in nuclear half-life measurements exhibiting time-dependent decay rates  

E-Print Network [OSTI]

In a recent series of papers evidence has been presented for correlations between solar activity and nuclear decay rates. This includes an apparent correlation between Earth-Sun distance and data taken at Brookhaven National Laboratory (BNL), and at the Physikalisch-Technische Bundesanstalt (PTB). Although these correlations could arise from a direct interaction between the decaying nuclei and some particles or fields emanating from the Sun, they could also represent an "environmental" effect arising from a seasonal variation of the sensitivities of the BNL and PTB detectors due to changes in temperature, relative humidity, background radiation, etc. In this paper, we present a detailed analysis of the responses of the detectors actually used in the BNL and PTB experiments, and show that sensitivities to seasonal variations in the respective detectors are likely too small to produce the observed fluctuations.

Jenkins, Jere H; Fischbach, Ephraim

2009-01-01T23:59:59.000Z

67

Analysis of environmental influences in nuclear half-life measurements exhibiting time-dependent decay rates  

E-Print Network [OSTI]

In a recent series of papers evidence has been presented for correlations between solar activity and nuclear decay rates. This includes an apparent correlation between Earth-Sun distance and data taken at Brookhaven National Laboratory (BNL), and at the Physikalisch-Technische Bundesanstalt (PTB). Although these correlations could arise from a direct interaction between the decaying nuclei and some particles or fields emanating from the Sun, they could also represent an "environmental" effect arising from a seasonal variation of the sensitivities of the BNL and PTB detectors due to changes in temperature, relative humidity, background radiation, etc. In this paper, we present a detailed analysis of the responses of the detectors actually used in the BNL and PTB experiments, and show that sensitivities to seasonal variations in the respective detectors are likely too small to produce the observed fluctuations.

Jere H. Jenkins; Daniel W. Mundy; Ephraim Fischbach

2009-12-29T23:59:59.000Z

68

Precise half-life measurement of the superallowed beta(+) emitter (38)K(m)  

E-Print Network [OSTI]

of Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6 J. C. Hardy and V. E. Iacob Cyclotron Institute at Texas A&M University, College Station, Texas 77843, USA J. R. Leslie and H.-B. Mak Department of Physics, Queen?s University...

Ball, G. C.; Boisvert, G.; Bricault, P.; Churchman, R.; Dombsky, M.; Lindner, T.; Macdonald, J. A.; Vandervoort, E.; Bishop, S.; D'Auria, J. M.; Hardy, John C.; Iacob, V. E.; Leslie, J. R.; Mak, H. -B.

2010-01-01T23:59:59.000Z

69

Towards a precision measurement of the half life of neutrinoless double beta decay of 136Xe.  

E-Print Network [OSTI]

??Recent neutrino oscillation experiments provide proof that neutrinos are massive par- ticles, but the absolute neutrino mass scale remains unknown. Observation of neu- trinoless double… (more)

Stanford University, Dept. of Physics

2011-01-01T23:59:59.000Z

70

Helioseismological Implications of Recent Solar Abundance Determinations  

E-Print Network [OSTI]

We show that standard solar models are in good agreement with the helioseismologically determined sound speed and density as a function of solar radius, the depth of the convective zone, and the surface helium abundance, as long as those models do not incorporate the most recent heavy element abundance determinations. However, sophisticated new analyses of the solar atmosphere infer lower abundances of the lighter metals (like C, N, O, Ne, and Ar) than the previously widely used surface abundances. We show that solar models that include the lower heavy element abundances disagree with the solar profiles of sound speed and density as well as the depth of the convective zone and the helium abundance. The disagreements for models with the new abundances range from factors of several to many times the quoted uncertainties in the helioseismological measurements. The disagreements are at temperatures below what is required for solar interior fusion reactions and therefore do not significantly affect solar neutrino emission. If errors in thecalculated OPAL opacities are solely responsible for the disagreements, then the corrections in the opacity must extend from 2 times 10^6 K (R = 0.7R_Sun)to 5 times 10^6 K (R = 0.4 R_Sun), with opacity increases of order 10%.

John N. Bahcall; Sarbani Basu; Marc Pinsonneault; Aldo M. Serenelli

2004-09-26T23:59:59.000Z

71

Oxygen abundance of open cluster dwarfs  

E-Print Network [OSTI]

We present oxygen abundances of dwarfs in the young open cluster IC 4665 deduced from the OI $\\lambda$7774 triplet lines and of dwarfs in the open cluster Pleiades derived from the [OI] $\\lambda$6300 forbidden line. Stellar parameters and oxygen abundances were derived using the spectroscopic synthesis tool SME (Spectroscopy Made Easy). We find a dramatic increase in the upper boundary of the OI triplet abundances with decreasing temperature in the dwarfs of IC 4665, consistent with the trend found by Schuler et al. in the open clusters Pleiades and M 34, and to a less extent in the cool dwarfs of Hyades (Schuler et al. 2006a) and UMa (King & Schuler 2005). By contrast, oxygen abundances derived from the [OI] $\\lambda$6300 forbidden line for stars in Pleiades and Hyades (Schuler et al. 2006b) are constant within the errors. Possible mechanisms that may lead a varying oxygen triplet line abundance are examined, including systematic errors in the stellar parameter determinations, the NLTE effects, surface activities and granulation. The age-related effects stellar surface activities (especially the chromospheric activities) are suggested by our analysis to blame for the large spreads of oxygen triplet line abundances.

Z. -X. Shen; X. -W. Liu; H. -W. Zhang; B. Jones; D. N. C. Lin

2007-03-30T23:59:59.000Z

72

Element abundances in solar energetic particles: two physical processes, two abundance patterns  

E-Print Network [OSTI]

Abundances of elements comprising solar energetic particles (SEPs) come with two very different patterns. Historically called "impulsive" and "gradual" events, they have been studied for 40 years, 20 years by the Wind spacecraft. Gradual SEP events measure coronal abundances. They are produced when shock waves, driven by coronal mass ejections (CMEs), accelerate the ambient coronal plasma; we discuss the average abundances of 21 elements that differ from corresponding solar photospheric abundances by a well-known dependence on the first ionization potential (FIP) of the element. The smaller impulsive ("3He-rich") SEP events are associated with magnetic reconnection involving open field lines from solar flares or jets that also eject plasma to produce accompanying CMEs. These events produce striking heavy-element abundance enhancements, relative to coronal abundances, by an average factor of 3 at Ne, 9 at Fe, and 900 for elements with 76 0.1 are even more strongly associated with narrow, slow CMEs, cooler coro...

Reames, Donald V

2015-01-01T23:59:59.000Z

73

N-15 NMR spectra of naturally abundant nitrogen in soil and aquatic natural  

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: VegetationEquipment SurfacesResource ProgramModificationEnzyme-FunctionalizedCirculatoryo r t h Forganic

74

Dual spatial maps of transcript and protein abundance in the...  

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

Dual spatial maps of transcript and protein abundance in the mouse brain. Dual spatial maps of transcript and protein abundance in the mouse brain. Abstract: Integrating...

75

Topological Analysis of Protein Co-Abundance Networks Identifies...  

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

Topological Analysis of Protein Co-Abundance Networks Identifies Novel Host Targets Important for HCV Infection and Pathogenesis Topological Analysis of Protein Co-Abundance...

76

Engineering Density of States of Earth Abundant Semiconductors...  

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

of States of Earth Abundant Semiconductors for Enhanced Thermoelectric Power Factor Engineering Density of States of Earth Abundant Semiconductors for Enhanced Thermoelectric...

77

Mapping protein abundance patterns in the brain using voxelation...  

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

protein abundance patterns in the brain using voxelation combined with liquid chromatography and mass spectrometry. Mapping protein abundance patterns in the brain using voxelation...

78

Abundance of narwhals (Monodon monoceros) on the hunting grounds in Greenland  

E-Print Network [OSTI]

Abundance of narwhals (Monodon monoceros) on the hunting grounds in Greenland M. P. HEIDE Greenland Institute of Natural Resources, Bok 570, 3900 Nuuk, Greenland (MPH, KLL, RGH) RUWPA, University to subsistence hunting by Inuit in Greenland and Canada. Scientific advice on the sustainable levels of removals

Laidre, Kristin L.

79

NREL Explores Earth-Abundant Materials for Future Solar Cells (Fact Sheet)  

SciTech Connect (OSTI)

Researchers at the National Renewable Energy Laboratory (NREL) are using a theory-driven technique - sequential cation mutation - to understand the nature and limitations of promising solar cell materials that can replace today's technologies. Finding new materials that use Earth-abundant elements and are easily manufactured is important for large-scale solar electricity deployment.

Not Available

2012-10-01T23:59:59.000Z

80

Abundances of massive stars: some recent developments  

E-Print Network [OSTI]

Thanks to their usefulness in various fields of astrophysics (e.g. mixing processes in stars, chemical evolution of galaxies), the last few years have witnessed a large increase in the amount of abundance data for early-type stars. Two intriguing results emerging since the last reviews on this topic will be discussed: (a) nearby OB stars exhibit metal abundances generally lower than the solar/meteoritic estimates; (b) evolutionary models of single objects including rotation are largely unsuccessful in explaining the CNO properties of stars in the Galaxy and in the Magellanic clouds.

T. Morel

2008-11-25T23:59:59.000Z

Note: This page contains sample records for the topic "natural abundance half-life" 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

Relative Abundance Measurements in Plumes and Interplumes  

E-Print Network [OSTI]

We present measurements of relative elemental abundances in plumes and interplumes. Plumes are bright, narrow structures in coronal holes that extend along open magnetic field lines far out into the corona. Previous work has found that in some coronal structures the abundances of elements with a low first ionization potential (FIP) 10 eV). We have used EIS spectroscopic observations made on 2007 March 13 and 14 over an ~24 hour period to characterize abundance variations in plumes and interplumes. To assess their elemental composition, we have used a differential emission measure (DEM) analysis, which accounts for the thermal structure of the observed plasma. We have used lines from ions of iron, silicon, and sulfur. From these we have estimated the ratio of the iron and silicon FIP bias relative to that for sulfur. From the results, we have created FIP-bias-ratio maps. We find that the FIP-bias ratio is sometimes higher in plumes than in interplumes and that this enhancement can be time dependent. These res...

Guennou, Chloé; Savin, Daniel Wolf

2015-01-01T23:59:59.000Z

82

Lithium abundances in globular cluster giants: NGC 1904, NGC 2808, and NGC 362  

E-Print Network [OSTI]

The presence of multiple populations in globular clusters has been well established thanks to high-resolution spectroscopy. It is widely accepted that distinct populations are a consequence of different stellar generations: intra-cluster pollution episodes are required to produce the peculiar chemistry observed in almost all clusters. Unfortunately, the progenitors responsible have left an ambiguous signature and their nature remains unresolved. To constrain the candidate polluters, we have measured lithium and aluminium abundances in more than 180 giants across three systems: NGC~1904, NGC~2808, and NGC~362. The present investigation along with our previous analysis of M12 and M5 affords us the largest database of simultaneous determinations of Li and Al abundances. Our results indicate that Li production has occurred in each of the three clusters. In NGC~362 we detected an M12-like behaviour, with first and second-generation stars sharing very similar Li abundances favouring a progenitor that is able to pro...

D'Orazi, V; Angelou, G C; Bragaglia, A; Carretta, E; Lattanzio, J C; Lucatello, S; Momany, Y; Sollima, A; Beccari, G

2015-01-01T23:59:59.000Z

83

Fermilab | Science | Inquiring Minds | Questions About Physics  

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

is comparable to the apparent age of the earth. The 3 natural series are headed by Thorium 232 (half-life 1.4 E10 years) called the thorium series, Uranium 238 (half-life ...

84

Oxygen abundances in planet-harbouring stars. Comparison of different abundance indicators  

E-Print Network [OSTI]

We present a detailed and uniform study of oxygen abundances in 155 solar type stars, 96 of which are planet hosts and 59 of which form part of a volume-limited comparison sample with no known planets. EW measurements were carried out for the [O I] 6300 \\AA line and the O I triplet, and spectral synthesis was performed for several OH lines. NLTE corrections were calculated and applied to the LTE abundance results derived from the O I 7771-5 \\AA\\ triplet. Abundances from [O I], the O I triplet and near-UV OH were obtained in 103, 87 and 77 dwarfs, respectively. We present the first detailed and uniform comparison of these three oxygen indicators in a large sample of solar-type stars. There is good agreement between the [O/H] ratios from forbidden and OH lines, while the NLTE triplet shows a systematically lower abundance. We found that discrepancies between OH, [O I] and the O I triplet do not exceed 0.2 dex in most cases. We have studied abundance trends in planet host and comparison sample stars, and no obvious anomalies related to the presence of planets have been detected. All three indicators show that, on average, [O/Fe] decreases with [Fe/H] in the metallicity range -0.8oxygen overabundance of 0.1-0.2dex with respect to the comparison sample.

A. Ecuvillon; G. Israelian; N. C. Santos; N. G. Shchukina; M. Mayor; R. Rebolo

2005-09-13T23:59:59.000Z

85

CORONAL ABUNDANCES IN ORION NEBULA CLUSTER STARS A. Maggio,1  

E-Print Network [OSTI]

pattern of abundances for all stars, although a weak dependence on flare loop size may be present. The abundance of calcium is the only one which appears to vary substantially between stars, but this quantity

Micela, Giusi

86

abundance depth distribution: Topics by E-print Network  

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

12: 488-501 I N T R O DU C T I O N The species abundance distribution (SAD Enquist, Brian Joseph 4 Fauna, Distribution, Habitat Preference and Abundance CiteSeer Summary:...

87

abundance distribution composition: Topics by E-print Network  

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

12: 488-501 I N T R O DU C T I O N The species abundance distribution (SAD Enquist, Brian Joseph 6 Fauna, Distribution, Habitat Preference and Abundance CiteSeer Summary:...

88

abundance distribution results: Topics by E-print Network  

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

12: 488-501 I N T R O DU C T I O N The species abundance distribution (SAD Enquist, Brian Joseph 4 Fauna, Distribution, Habitat Preference and Abundance CiteSeer Summary:...

89

Lithium abundances in exoplanet-hosts stars  

E-Print Network [OSTI]

Exoplanet-host stars (EHS) are known to present surface chemical abundances different from those of stars without any detected planet (NEHS). EHS are, on the average, overmetallic compared to the Sun. The observations also show that, for cool stars, lithium is more depleted in EHS than in NEHS. The overmetallicity of EHS may be studied in the framework of two different scenarii. We have computed main sequence stellar models with various masses, metallicities and accretion rates. The results show different profiles for the lithium destruction according to the scenario. We compare these results to the spectroscopic observations of lithium.

M. Castro; S. Vauclair; O. Richard; N. C. Santos

2008-03-20T23:59:59.000Z

90

Primordial Li abundance and massive particles  

SciTech Connect (OSTI)

The problem of the observed lithium abundance coming from the Big Bang Nucleosynthesis is as of yet unsolved. One of the proposed solutions is including relic massive particles into the Big Bang Nucleosynthesis. We investigated the effects of such particles on {sup 4}HeX{sup -}+{sup 2}H{yields}{sup 6}Li+X{sup -}, where the X{sup -} is the negatively charged massive particle. We demonstrate the dominance of long-range part of the potential on the cross-section.

Latin-Capital-Letter-Eth apo, H. [Department of Physics, Akdeniz University, TR-07058, Antalya (Turkey)

2012-10-20T23:59:59.000Z

91

SAFS-UW-1001 Abundance of Adult Hatchery and Wild  

E-Print Network [OSTI]

SAFS-UW-1001 July 2010 Abundance of Adult Hatchery and Wild Salmon by Region of the North Pacific Moore Foundation #12;Hatchery and Wild Salmon Abundance Page ii TABLE OF CONTENTS Page Introduction .............................................................................................................................. 1 Approaches to estimating wild salmon spawner abundances......................................... 1

Washington at Seattle, University of

92

Oxygen Abundance Measurements of SHIELD Galaxies  

E-Print Network [OSTI]

We have derived oxygen abundances for 8 galaxies from the Survey of HI in Extremely Low-mass Dwarfs (SHIELD). The SHIELD survey is an ongoing study of very low-mass galaxies, with M$_{\\rm HI}$ between 10$^{6.5}$ and 10$^{7.5}$ M$_{\\odot}$, that were detected by the Arecibo Legacy Fast ALFA (ALFALFA) survey. H$\\alpha$ images from the WIYN 3.5m telescope show that these 8 SHIELD galaxies each possess one or two active star-forming regions which were targeted with long-slit spectral observations using the Mayall 4m telescope at KPNO. We obtained a direct measurement of the electron temperature by detection of the weak [O III] $\\lambda$4363 line in 2 of the HII regions. Oxygen abundances for the other HII regions were estimated using a strong-line method. When the SHIELD galaxies are plotted on a B-band luminosity-metallicity diagram they appear to suggest a slightly shallower slope to the relationship than normally seen. However, that offset is systematically reduced when the near-infrared luminosity is used ins...

Haurberg, Nathalie C; Cannon, John M; Marshall, Melissa V

2015-01-01T23:59:59.000Z

93

Element Abundances through the Cosmic Ages  

E-Print Network [OSTI]

The horizon for studies of element abundances has expanded dramatically in the last ten years. Once the domain of astronomers concerned chiefly with stars and nearby galaxies, this field has now become a key component of observational cosmology, as technological advances have made it possible to measure the abundances of several chemical elements in a variety of environments at redshifts up to z = 4, when the universe was in its infancy. In this series of lectures I summarise current knowledge on the chemical make-up of distant galaxies observed directly in their starlight, and of interstellar and intergalactic gas seen in absorption against the spectra of bright background sources. The picture which is emerging is one where the universe at z = 3 already included many of the constituents of today's galaxies-even at these early times we see evidence for Population I and II stars, while the `smoking gun' for Population III objects may be hidden in the chemical composition of the lowest density regions of the intergalactic medium, yet to be deciphered.

Max Pettini

2003-03-12T23:59:59.000Z

94

Relationship of Course Woody Debris to Red-Cockaded Woodpecker Prey Diversity and Abundance  

SciTech Connect (OSTI)

The abundance of diversity of prey commonly used by the red-cockaded woodpecker were monitored in experimental plots in which course woody debris was manipulated. In one treatment, all the woody debris over four inches was removed. In the second treatment, the natural amount of mortality remained intact. The overall diversity of prey was unaffected; however, wood roaches were significantly reduced by removal of woody debris. The latter suggests that intensive utilizations or harvesting practices may reduce foraging.

Horn, G.S.

1999-09-03T23:59:59.000Z

95

The Solar Heavy Element Abundances: I. Constraints from Stellar Interiors  

E-Print Network [OSTI]

The latest solar atmosphere models include non-LTE corrections and 3D hydrodynamic convection simulations. These models predict a significant reduction in the solar metal abundance, which leads to a serious conflict between helioseismic data and the predictions of solar interiors models. We demonstrate that the helioseismic constraints on the surface convection zone depth and helium abundance combined with stellar interiors models can be used to define the goodness of fit for a given chemical composition. After a detailed examination of the errors in the theoretical models we conclude that models constructed with the older solar abundances are consistent (seismic data. Models constructed with the proposed new low abundance scale are strongly disfavored, disagreeing at the 15 \\sigma level. We then use the sensitivity of the seismic properties to abundance changes to invert the problem and infer a seismic solar heavy element abundance mix with two components: meteoritic abundances, and th...

Delahaye, F; Delahaye, Franck; Pinsonneault, Marc

2005-01-01T23:59:59.000Z

96

Abundance ratios in hierarchical galaxy formation  

E-Print Network [OSTI]

The chemical enrichment and stellar abundance ratios of galaxies which form in a hierarchical clustering scheme are calculated. For this purpose I adopt the star formation histories (SFH) as they are delivered by semi-analytic models in Kauffmann (1996}. It turns out that the average SFH of cluster ellipticals does not yield globally alpha-enhanced stellar populations. The star burst that occurs when the elliptical forms in the major merger plays therefore a crucial role in producing alpha-enhancement. Only under the assumption that the IMF is significantly flattened with respect to the Salpeter value during the burst, a Mg/Fe overabundant population can be obtained. In particular for the interpretation of radial gradients in metallicity and alpha-enhancement, the mixing of global and burst populations are of great importance. The model predicts bright field galaxies to be less alpha-enhanced than their counterparts in clusters.

D. Thomas

1999-01-18T23:59:59.000Z

97

The Solar Heavy Element Abundances: I. Constraints from Stellar Interiors  

E-Print Network [OSTI]

The latest solar atmosphere models include non-LTE corrections and 3D hydrodynamic convection simulations. These models predict a significant reduction in the solar metal abundance, which leads to a serious conflict between helioseismic data and the predictions of solar interiors models. We demonstrate that the helioseismic constraints on the surface convection zone depth and helium abundance combined with stellar interiors models can be used to define the goodness of fit for a given chemical composition. After a detailed examination of the errors in the theoretical models we conclude that models constructed with the older solar abundances are consistent (seismic data. Models constructed with the proposed new low abundance scale are strongly disfavored, disagreeing at the 15 \\sigma level. We then use the sensitivity of the seismic properties to abundance changes to invert the problem and infer a seismic solar heavy element abundance mix with two components: meteoritic abundances, and the light metals CNONe. Seismic degeneracies between the best solutions for the elements arise for changes in the relative CNONe abundances and their effects are quantified. We obtain Fe/H=7.50+/-0.045+/-0.003(CNNe) and O/H=8.86+/-0.041+/-0.025(CNNe) for the relative CNNe in the GS98 mixture. The inferred solar oxygen abundance disagree with the abundance inferred from the 3D hydro models. Changes in the Ne abundance can mimic changes in O for the purposes of scalar constraints.Models constructed with low oxygen and high neon are inconsistent with the solar sound speed profile. The implications for the solar abundance scale are discussed.

Franck Delahaye; Marc Pinsonneault

2005-11-29T23:59:59.000Z

98

CHEMICAL ABUNDANCES IN CLUSTERS OF GALAXIES  

E-Print Network [OSTI]

We study the origin of iron and alpha-elements (O, Mg, Si) in clusters of galaxies. In particular, we discuss the [O/Fe] ratio and the iron mass-to-luminosity ratio in the intracluster medium (ICM) and their link to the chemical and dynamical evolution of elliptical and lenticular galaxies. We adopt a detailed model of galactic evolution incorporating the development of supernovae- driven galactic winds which pollute the ICM with enriched ejecta. We demonstrate \\it quantitatively \\rm the crucial dependence upon the assumed stellar initial mass function in determining the evolution of the mass and abundances ratios of heavy elements in typical model ICMs. We show that completely opposite behaviours of [alpha/Fe] ratios (\\ie positive versus negative ratios) can be obtained by varying the initial mass function without altering the classic assumptions regarding type Ia supernovae progenitors or their nucleosynthesis. Our results indicate that models incorporating somewhat flatter-than-Salpeter initial mass functions (ie x approx 1, as opposed to x=1.35) are preferred, provided the intracluster medium iron mass-to-luminosity ratio, preliminary [alpha/Fe]>0 ASCA results, and present-day type Ia supernovae rates, are to be matched. A simple Virgo cluster simulation which adheres to these constraints shows that approx 70% of the measured ICM iron mass has its origin in type II supernovae, with the remainder being synthesized in type Ia systems.

Francesca Matteucci; Brad K. Gibson

1995-03-14T23:59:59.000Z

99

Comparing halo bias from abundance and clustering  

E-Print Network [OSTI]

We model the abundance of haloes in the $\\sim(3 \\ \\text{Gpc}/h)^3$ volume of the MICE Grand Challenge simulation by fitting the universal mass function with an improved Jack-Knife error covariance estimator that matches theory predictions. We present unifying relations between different fitting models and new predictions for linear ($b_1$) and non-linear ($c_2$ and $c_3$) halo clustering bias. Different mass function fits show strong variations in their overall poor performance when including the low mass range ($M_h \\lesssim 3 \\ 10^{12} \\ M_{\\odot}/h$) in the analysis, which indicates noisy friends-of-friends halo detection given the MICE resolution ($m_p \\simeq 3 \\ 10^{10} \\ M_{\\odot}$/h). Together with fits from the literature we find an overall variance in the amplitudes of around $10%$ in the low mass and up to $50%$ in the high mass (galaxy cluster) range ($M_h > 10^{14} \\ M_{\\odot}/h$). These variations propagate into a $10%$ change in $b_1$ predictions and a $50%$ change in $c_2$ or $c_3$. Despite the...

Hoffmann, Kai; Gaztanaga, Enrique

2015-01-01T23:59:59.000Z

100

Oxygen abundances in the most oxygen-rich spiral galaxies  

E-Print Network [OSTI]

Oxygen abundances in the spiral galaxies expected to be richest in oxygen are estimated. The new abundance determinations are based on the recently discovered ff-relation between auroral and nebular oxygen line fluxes in HII regions. We find that the maximum gas-phase oxygen abundance in the central regions of spiral galaxies is 12+log(O/H)~8.75. This value is significantly lower than the previously accepted value. The central oxygen abundance in the Milky Way is similar to that in other large spirals.

L. S. Pilyugin; T. X. Thuan; J. M. Vilchez

2006-01-06T23:59:59.000Z

Note: This page contains sample records for the topic "natural abundance half-life" 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

Planning Amid Abundance: Alaska’s FY 2013 Budget Process  

E-Print Network [OSTI]

state’s incentives for oil investment are excessive” (FDNM,increased oil industry investment. Planning Amid Abundance:oil corporations said that additional investment was

McBeath, Jerry

2013-01-01T23:59:59.000Z

102

High-Performance Thermoelectric Devices Based on Abundant Silicide...  

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

vehicle waste heat recovery will include fundamental research to use abundant promising low-cost thermoelectric materials, thermal management and interfaces design, and metrology...

103

On the Alpha Activity of Natural Tungsten Isotopes  

E-Print Network [OSTI]

The indication for the ? decay of 180W with a half-life T ? 1/2 =1.1+0.8 ?0.4(stat)±0.3(syst)×1018 yr has been observed for the first time with the help of the super-low background 116CdWO4 crystal scintillators. In conservative approach the lower limit on half-life of 180W has been established as T ? 1/2 (180W) ? 0.7×1018 yr at 90 % C.L. Besides, new T ? 1/2 bounds were set for ? decay of

F. A. Danevich A; A. Sh. Georgadze A; V. V. Kobychev A; S. S. Nagorny A; A. S. Nikolaiko A; W

104

Half-life of the electron-capture decay of (97)Ru: Precision measurement shows no temperature dependence  

E-Print Network [OSTI]

.8382(14) d at 19K, are consistent with, but much more precise than, previous room-temperature measurements. In addition, we have also measured the half-lives of the beta(-)-emitters (103)Ru and (105)Rh at both temperatures, and found them also to be unchanged....

Goodwin, J. R.; Golovko, V. V.; Iacob, V. E.; Hardy, John C.

2009-01-01T23:59:59.000Z

105

Measurement of the Double-Beta Decay Half-life of 136Xe in KamLAND-Zen  

E-Print Network [OSTI]

by fallout from the Fukushima-I reactor accident in Marchof detector materials by Fukushima fallout, which includeCo are not detected near Fukushima or our soil samples, we

Gando, A.

2013-01-01T23:59:59.000Z

106

Quantification of Global MicroRNA Abundance by Selective Isotachophoresis  

E-Print Network [OSTI]

) for the quantification of global microRNA (miRNA) abundance in total RNA. We leverage the selectivity of ITP-throughput methods to quantify the global abundance of miRNAs in total RNA samples derived from diverse sources which allows fast, accurate, and absolute measurement of global miRNA levels from small amounts of total

Santiago, Juan G.

107

The Ne/O abundance ratio in the quiet Sun  

E-Print Network [OSTI]

Aims: To determine the neon-to-oxygen abundance in the quiet Sun, a proxy for the photospheric abundance ratio. Method: An emission measure method applied to extreme ultraviolet emission lines of Ne IV-VI and O III-V ions observed by the Coronal Diagnostic Spectrometer on the SOHO satellite. Results: The average Ne/O abundance ratio in supergranule cell centre regions is 0.18 +/- 0.05, while in supergranule network regions is 0.16 +/- 0.04. A photospheric Ne/O ratio of 0.17 +/- 0.05 is suggested, in good agreement with the most recent compilation of solar photospheric abundances, but discrepant with a recent Ne/O ratio derived from stellar X-ray spectra and revised neon abundances suggested from solar interior models.

P. R. Young

2005-10-10T23:59:59.000Z

108

Radiation Doses to Hanford Workers from Natural Potassium-40  

SciTech Connect (OSTI)

The chemical element potassium is an essential mineral in people and is subject to homeostatic regulation. Natural potassium comprises three isotopes, 39K, 40K, and 41K. Potassium-40 is radioactive, with a half life of 1.248 billion years. In most transitions, it emits a ?? particle with a maximum energy of 0.560 MeV, and sometimes a gamma photon of 1.461 MeV. Because it is ubiquitous, 40K produces radiation dose to all human beings. This report contains the results of new measurements of 40K in 248 adult females and 2,037 adult males performed at the Department of Energy Hanford Site in 2006 and 2007. Potassium concentrations diminish with age, are generally lower in women than in men, and decrease with body mass index (BMI). The average annual effective dose from 40K in the body is 0.149 mSv y?1 for men and 0.123 mSv y?1 women respectively. Averaged over both men and women, the average effective dose per year is 0.136 mSv y?1. Calculated effective doses range from 0.069 to 0.243 mSv y?1 for adult males, and 0.067 to 0.203 mSv y?1 for adult females, a roughly three-fold variation for each gender. The need for dosimetric phantoms with a greater variety of BMI values should be investigated. From our data, it cannot be determined whether the potassium concentration in muscle in people with large BMI values differs from that in people with small BMI values. Similarly, it would be important to know the potassium concentration in other soft tissues, since much of the radiation dose is due to beta radiation, in which the source and target tissues are the same. These uncertainties should be evaluated to determine their consequences for dosimetry.

Strom, Daniel J.; Lynch, Timothy P.; Weier, Dennis R.

2009-02-13T23:59:59.000Z

109

Macroinvertebrate Abundance and Biomass: 2007 Data, BPA-51; Preliminary Report, February 10, 2009..  

SciTech Connect (OSTI)

Four Excel files containing information on the 2007 macroinvertebrate data were initially provided to Statistical Consulting Services (SCS) by EcoAnalysts on 1/27/2009. These data files contained information on abundance and biomass data at the level of taxonomic groups. The data were subsequently reformatted and compiled, and aggregated for analysis by SCS. All descriptions and analyses below relate to this compiled data. Computations were carried out separately for each site over all sample periods. Basic summary information for both the abundance and biomass data is presented in Print Out No.2. The 14 sites varied widely in their minimum, mean, maximum and variance values. The number of observations ranged from 10 to 18. Some large abundance values (abundance > 40,000) were noted for sites KR6 and KR13. A more detailed summary of each site is given in Print Out No.3. Site KR3, for example, had a mean abundance of 6914 with a sample size of 17. The variance was 4591991 and the standard error of the mean was 1643. The skewness value, a measure of symmetry for the frequency distribution, was moderately large at 1.29 indicating an asymmetric distribution. Biomass for KR3 had a mean value of 0.87 g/m{sup 2} with 17 observations. The variance was 0.8872 and the standard error was 0.228 g/m{sup 2}. Skewness for biomass was also high at 1.29. Further examination of the quantiles and frequency plots for abundance and biomass also indicate considerable skewness. The stem and leaf diagram (frequency plot) for abundance in KR3 shows most of the data centered on smaller values with a few very large counts. The distribution for biomass has a similar pattern. Statistical tests for normality are significant for both response variables in KR3, thus, the hypothesis that the data originates from a symmetric normal distribution is rejected. Because sample size estimation and statistical inference assume normally distributed data, a transformation of the data is required prior to further analysis. As was the case for previous years, the natural logarithm was chosen as a transformation to mitigate distributional skewness. Abundance and biomass for the remaining sites were also notably skewed, therefore, these data were also log transformed prior to analysis. Summary information for the transformed data (referred to as L-abun and L-bio for abundance and biomass, respectively) are given in Print Out No.4. For site KR3, the logarithmic transformation reduced skewness value for biomass to -0.66. The distributions of abundance and biomass in the other sites also generally showed improvement as well. Hence, all subsequent statistical analyses reported here will be based on the log transformed data.

Holderman, Charles

2009-02-10T23:59:59.000Z

110

animal prey abundance: Topics by E-print Network  

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

overall abundance was higher overall during the August 1997 cruise than during the October 1996 cruise... Cady, Robert B 2012-06-07 42 The camp will expose students to local...

111

Fundamental constraints on the abundances of chemotaxis proteins  

E-Print Network [OSTI]

Flagellated bacteria, such as Escherichia coli, perform directed motion in gradients of concentration of attractants and repellents in a process called chemotaxis. The E. coli chemotaxis signaling pathway is a model for signal transduction, but it has unique features. We demonstrate that the need for fast signaling necessitates high abundances of the proteins involved in this pathway. We show that further constraints on the abundances of chemotaxis proteins arise from the requirements of self-assembly, both of flagellar motors and of chemoreceptor arrays. All these constraints are specific to chemotaxis, and published data confirm that chemotaxis proteins tend to be more highly expressed than their homologs in other pathways. Employing a chemotaxis pathway model, we show that the gain of the pathway at the level of the response regulator CheY increases with overall chemotaxis protein abundances. This may explain why, at least in one E. coli strain, the abundance of all chemotaxis proteins is higher in media w...

Bitbol, Anne-Florence

2015-01-01T23:59:59.000Z

112

Relative abundance of desert tortoises on the Nevada Test Site  

SciTech Connect (OSTI)

Seven hundred fifty-nine transects having a total length of 1,191 km were walked during 1981--1986 to determine the distribution and relative abundance of desert tortoises (Gopherus agassizii) on the Nevada Test Site (NTS). The abundance of tortoises on NTS was low to very low relative to other populations in the Mojave Desert. Sign of tortoises was found from 880 to 1,570 m elevation and was more abundant above 1,200 m than has been reported previously for Nevada. Tortoises were more abundant on NTS on the upper alluvial fans and slopes of mountains than in valley bottoms. They also were more common on or near limestone and dolomite mountains than on mountains of volcanic origin.

Rautenstrauch, K.R.; O`Farrell, T.P.

1993-12-31T23:59:59.000Z

113

Relationships between body size and abundance in ecology  

E-Print Network [OSTI]

, but interrelated, relation- ships between size and abundance that are often con- fused in the literature. Here, we and the structure and dynamics of eco- logical communities [3­5]. In addition, because body size is one

Enquist, Brian Joseph

114

Planning Amid Abundance: Alaska’s FY 2013 Budget Process  

E-Print Network [OSTI]

2011) “The Outlier State: Alaska’s FY 2012 Budget,” AnnualWestern States Budget Review. New York Times, selectedAbundance: Alaska’s FY 2013 Budget Process Abstract: This

McBeath, Jerry

2013-01-01T23:59:59.000Z

115

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...

116

Cyclotron production of {sup 61}Cu using natural Zn and enriched {sup 64}Zn targets  

SciTech Connect (OSTI)

Copper-61 ({sup 61}Cu) shares with {sup 64}Cu certain advantages for PET diagnostic imaging, but has a shorter half-life (3.4hr vs. 12.7hr) and a greater probability of positron production per disintegration (61% vs. 17.9%). One important application is for in vivo imaging of hypoxic tissue. In this study {sup 61}Cu was produced using the {sup 64}Zn(p,{alpha}){sup 61}Cu reaction on natural Zn or enriched {sup 64}Zn targets. The enriched {sup 64}Zn (99.82%) was electroplated onto high purity gold or silver foils or onto thin Al discs. A typical target bombardment used 30{mu}A; at 11.7, 14.5 or 17.6MeV over 30-60min. The {sup 61}Cu (radiochemical purity of >95%) was separated using a combination of cation and anion exchange columns. The {sup 64}Zn target material was recovered after each run, for re-use. In a direct comparison with enriched {sup 64}Zn-target results, {sup 61}Cu production using the cheaper {sup nat}Zn target proved to be an effective alternative.

Asad, A. H.; Smith, S. V.; Chan, S.; Jeffery, C. M.; Morandeau, L.; Price, R. I. [RAPID PET Labs, Medical Technology and Physics, Sir Charles Gairdner Hospital, Perth, Australia, Imaging and Applied Physics, Curtin University, Perth, Australia, and Center of Excellence in Anti-matter Matter Studies, Australian National University, Can (Australia); Brookhaven National Laboratory, Upton, NY (United States) and Center of Excellence in Anti-matter Matter Studies, Australian National University, Canberra (Australia); RAPID PET Labs, Medical Technology and Physics, Sir Charles Gairdner Hospital, Perth (Australia); RAPID PET Labs, Medical Technology and Physics, Sir Charles Gairdner Hospital, Perth (Australia); Center of Excellence in Anti-matter Matter Studies, Australian National University, Canberra, Australia, and Chemistry, University of Western Australia, Pe (Australia); RAPID PET Labs, Medical Technology and Physics, Sir Charles Gairdner Hospital, Perth (Australia); RAPID PET Labs, Medical Technology and Physics, Sir Charles Gairdner Hospital, Perth, Australia and Physics, University of Western Australia, Perth (Australia)

2012-12-19T23:59:59.000Z

117

Natural Abundance Radiocarbon Studies of Dissolved Organic Carbon (DOC) in the Marine Environment  

E-Print Network [OSTI]

Press, San Diego. Bruland, K.W. , (1989) Complexation of6624), 480-482. Rue, E.L. , Bruland, K.W. , (1997) The rolemetal binding ligands (Bruland, 1989; Rue and Bruland, 1997;

de Jesus, Roman P

2008-01-01T23:59:59.000Z

118

Natural abundance radiocarbon studies of dissolved organic carbon (DOC) in the marine environment  

E-Print Network [OSTI]

Press, San Diego. Bruland, K.W. , (1989) Complexation of6624), 480-482. Rue, E.L. , Bruland, K.W. , (1997) The rolemetal binding ligands (Bruland, 1989; Rue and Bruland, 1997;

De Jesus, Roman Paul

2008-01-01T23:59:59.000Z

119

-Amino acids, although less abundant than their -analogues, are also present in peptides and other natural  

E-Print Network [OSTI]

. A number of methods for synthesis and transformations leading to -amino acids in diastereomerically as key structural components has recently attracted attention in synthetic organic chemistry because Polyhydroxyalkanoates (PHAs) are a family of carbon, energy and/or reducing power storage polymers, which

120

N-15 NMR spectra of naturally abundant nitrogen in soil and aquatic...  

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

Soil samples include humic and fulvic acids from the Elliot soil, Minnesota Waskish peat and Florida Pahokee peat, as well as the Summit Hill soil humic acid and the Leonardite...

Note: This page contains sample records for the topic "natural abundance half-life" 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

Source apportionment of atmospheric PAHs in the Western Balkans by natural abundance radiocarbon analysis  

SciTech Connect (OSTI)

Progress in source apportionment of priority combustion-derived atmospheric pollutants can be made by an inverse approach to inventory emissions, namely, receptor-based compound class-specific radiocarbon analysis (CCSRA) of target pollutants. In the present study, CCSRA of the combustion-derived polycyclic aromatic hydrocarbons (PAHs) present in the atmosphere of the countries of the former republic of Yugoslavia was performed. The carbon stable isotope composition ({delta}{sup 13}C) of PAHs varied between -27.68 and -27.19{per_thousand}, whereas {Delta}{sup 14}C values ranged from -568{per_thousand} for PAHs sampled in Kosovo to -288{per_thousand} for PAHs sampled in the Sarajevo area. The application of an isotopic mass balance model to these {Delta}{sup 14}C data revealed a significant contribution (35-65%) from the combustion of non-fossil material to the atmospheric PAH pollution, even in urban and industrialized areas. Furthermore, consistency was observed between the isotopic composition of PAHs obtained by high-volume sampling and those collected by passive sampling. This encourages the use of passive samplers for CCSRA applications. This marks the first time that a CCSRA investigation could be executed on a geographically wide scale, providing a quantitative field-based source apportionment, which points out that also non-fossil combustion processes should be targeted for remedial action. 36 refs., 1 fig., 3 tabs.

Zdenek Zencak; Jana Klanova; Ivan Holoubek; Oerjan Gustafsson [Stockholm University, Stockholm (Sweden). Department of Applied Environmental Science

2007-06-01T23:59:59.000Z

122

Sugar in Two Steps Hexose sugars are naturally abundant, but it is often useful to  

E-Print Network [OSTI]

on the decay of U isotopes to Pb can be problematic if damaged parts of zircons, the primary uranium that was quickly depleted. Observations of molecular clouds indicate that ultraviolet radiation selectively depleted in 16O. Yurimoto and Kuramoto (p. 1763; see the Perspective by Yin) have developed a model

Meyer, Karsten

123

Natural Abundance 43Ca NMR Spectroscopy of Tobermorite and Jennite: Model  

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 MayAtmosphericNuclear Security Administration the Contributions andDataNational Library of Energy2015 | JeffersonNationsCompounds for

124

Natural Abundance 43Ca NMR Spectroscopy of Tobermorite and Jennite: Model  

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 MayAtmosphericNuclear Security Administration the Contributions andDataNational Library of Energy2015 | JeffersonNationsCompounds

125

Natural Gas Supply in Denmark -A Model of Natural Gas Transmission and the  

E-Print Network [OSTI]

, which describes the markets for electricity and district heat. Specifically on the demand side Foundation for Gas Market Liberalization . . . . . . . . . . . 14 2.5 District Heating of the markets of natural gas and electricity and the existence of an abundance of de-centralized combined heat

126

Carbon and Strontium Abundances of Metal-Poor Stars  

E-Print Network [OSTI]

We present carbon and strontium abundances for 100 metal-poor stars measured from R$\\sim $7000 spectra obtained with the Echellette Spectrograph and Imager at the Keck Observatory. Using spectral synthesis of the G-band region, we have derived carbon abundances for stars ranging from [Fe/H]$=-1.3$ to [Fe/H]$=-3.8$. The formal errors are $\\sim 0.2$ dex in [C/Fe]. The strontium abundance in these stars was measured using spectral synthesis of the resonance line at 4215 {\\AA}. Using these two abundance measurments along with the barium abundances from our previous study of these stars, we show it is possible to identify neutron-capture-rich stars with our spectra. We find, as in other studies, a large scatter in [C/Fe] below [Fe/H]$ = -2$. Of the stars with [Fe/H]$<-2$, 9$\\pm$4% can be classified as carbon-rich metal-poor stars. The Sr and Ba abundances show that three of the carbon-rich stars are neutron-capture-rich, while two have normal Ba and Sr. This fraction of carbon enhanced stars is consistent with other studies that include this metallicity range.

David K. Lai; Jennifer A. Johnson; Michael Bolte; Sara Lucatello

2007-06-20T23:59:59.000Z

127

DIRECT EVALUATION OF THE HELIUM ABUNDANCES IN OMEGA CENTAURI  

SciTech Connect (OSTI)

A direct measure of the helium abundances from the near-infrared transition of He I at 1.08 {mu}m is obtained for two nearly identical red giant stars in the globular cluster Omega Centauri. One star exhibits the He I line; the line is weak or absent in the other star. Detailed non-local thermal equilibrium semi-empirical models including expansion in spherical geometry are developed to match the chromospheric H{alpha}, H{beta}, and Ca II K lines, in order to predict the helium profile and derive a helium abundance. The red giant spectra suggest a helium abundance of Y {<=} 0.22 (LEID 54064) and Y = 0.39-0.44 (LEID 54084) corresponding to a difference in the abundance {Delta}Y {>=} 0.17. Helium is enhanced in the giant star (LEID 54084) that also contains enhanced aluminum and magnesium. This direct evaluation of the helium abundances gives observational support to the theoretical conjecture that multiple populations harbor enhanced helium in addition to light elements that are products of high-temperature hydrogen burning. We demonstrate that the 1.08 {mu}m He I line can yield a helium abundance in cool stars when constraints on the semi-empirical chromospheric model are provided by other spectroscopic features.

Dupree, A. K.; Avrett, E. H., E-mail: dupree@cfa.harvard.edu, E-mail: eavrett@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)

2013-08-20T23:59:59.000Z

128

Rate Analysis or a Possible Interpretation of Abundances  

E-Print Network [OSTI]

Heavy elements are formed in nucleosynthesis processes. Abundances of these elements can be classified as elemental abundance, isotopic abundance, and abundance of nuclei. In this work we propose to change nucleon identification from the usual (Z,A) to (Z,N), which allows reading out new information from the measured abundances. We are interested in the neutron density required to reproduce the measured abundance of nuclei assuming equilibrium processes. This is only possible when two stable nuclei are separated by an unstable nucleus. At these places we investigated the neutron density required for equilibrium nucleosynthesis both isotopically and isotonically at temperatures of AGB interpulse and thermal pulse phases. We obtained an estimate for equilibrium nucleosynthesis neutron density in most of the cases. Next we investigated the possibility of partial formation of nuclei. We analyzed the meaning of the branching factor. We found a mathematical definition for the unified interpretation of a branching point closed at isotonic case and open at isotopic case. We introduce a more expressive variant of branching ratio called partial formation rate. With these we are capable of determining the characteristic neutron density values.

Miklos Kiss

2015-02-24T23:59:59.000Z

129

ISO/GUM UNCERTAINTIES AND CIAAW (UNCERTAINTY TREATMENT FOR RECOMMENDED ATOMIC WEIGHTS AND ISOTOPIC ABUNDANCES)  

SciTech Connect (OSTI)

The International Organization for Standardization (ISO) has published a Guide to the expression of Uncertainty in Measurement (GUM). The IUPAC Commission on Isotopic Abundance and Atomic Weight (CIAAW) began attaching uncertainty limits to their recommended values about forty years ago. CIAAW's method for determining and assigning uncertainties has evolved over time. We trace this evolution to their present method and their effort to incorporate the basic ISO/GUM procedures into evaluations of these uncertainties. We discuss some dilemma the CIAAW faces in their present method and whether it is consistent with the application of the ISO/GUM rules. We discuss the attempt to incorporate variations in measured isotope ratios, due to natural fractionation, into the ISO/GUM system. We make some observations about the inconsistent treatment in the incorporation of natural variations into recommended data and uncertainties. A recommendation for expressing atomic weight values using a tabulated range of values for various chemical elements is discussed.

HOLDEN,N.E.

2007-07-23T23:59:59.000Z

130

Cosmological Deuterium Abundance and the Baryon Density of the Universe  

E-Print Network [OSTI]

Standard big bang nucleosynthesis (BBNS) promises accurate predictions of the primordial abundances of deuterium, helium-3, helium-4 and lithium-7 as a function of a single parameter. Previous measurements have nearly always been interpreted as confirmation of the model (Copi, Schramm & Turner 1995). Here we present a measurement of the deuterium to hydrogen ratio (D/H) in a newly discovered high redshift metal-poor gas cloud at redshift $z=2.504$. This confirms our earlier measurement of D/H (Tytler, Fan & Burles 1996), and together they give the first accurate measurement of the primordial D abundance, and a ten fold improvement in the accuracy of the cosmological density of ordinary matter.This is a high density, with most ordinary matter unaccounted or dark, which is too high to agree with measurements of the primordial abundances of helium-4 and lithium-7. Since the D/H measurement is apparently simple, direct, accurate and highly sensitive, we propose that helium requires a systematic correction, and that population II stars have less than the primordial abundance of $^7$Li. Alternatively, there is no concordance between the light element abundances, and the simple model of the big bang must be incomplete and lacking physics, or wrong.

Scott Burles; David Tytler

1996-03-19T23:59:59.000Z

131

New solar opacities, abundances, helioseismology, and neutrino fluxes  

E-Print Network [OSTI]

We construct solar models with the newly calculated radiative opacities from the Opacity Project (OP) and recently determined (lower) heavy element abundances. We compare results from the new models with predictions of a series of models that use OPAL radiative opacities, older determinations of the surface heavy element abundances, and refinements of nuclear reaction rates. For all the variations we consider, solar models that are constructed with the newer and lower heavy element abundances advocated by Asplund et al. (2005) disagree by much more than the estimated measuring errors with helioseismological determinations of the depth of the solar convective zone, the surface helium composition, the internal sound speeds, and the density profile. Using the new OP radiative opacities, the ratio of the 8B neutrino flux calculated with the older and larger heavy element abundances (or with the newer and lower heavy element abundances) to the total neutrino flux measured by the Sudbury Neutrino Observatory is 1.09 (0.87) with a 9% experimental uncertainty and a 16% theoretical uncertainty, 1 sigma errors.

John N. Bahcall; Aldo M. Serenelli; Sarbani Basu

2005-01-19T23:59:59.000Z

132

Oxygen abundance in the Sloan Digital Sky Survey  

E-Print Network [OSTI]

We present two samples of $\\hii$ galaxies from the Sloan Digital Sky Survey (SDSS) spectroscopic observations data release 3. The electron temperatures($T_e$) of 225 galaxies are calculated with the photoionized $\\hii$ model and $T_e$ of 3997 galaxies are calculated with an empirical method. The oxygen abundances from the $T_e$ methods of the two samples are determined reliably. The oxygen abundances from a strong line metallicity indicator, such as $R_{23}$, $P$, $N2$, and $O3N2$, are also calculated. We compared oxygen abundances of $\\hii$ galaxies obtained with the $T_e$ method, $R_{23}$ method, $P$ method, $N2$ method, and $O3N2$method. The oxygen abundances derived with the $T_e$ method are systematically lower by $\\sim$0.2 dex than those derived with the $R_{23}$ method, consistent with previous studies based on $\\hii$ region samples. No clear offset for oxygen abundance was found between $T_e$ metallicity and $P$, $N2$ and $O3N2$ metallicity. When we studied the relation between N/O and O/H, we found that in the metallicity regime of $\\zoh > 7.95$, the large scatter of the relation can be explained by the contribution of small mass stars to the production of nitrogen. In the high metallicity regime, $\\zoh > 8.2$, nitrogen is primarily a secondary element produced by stars of all masses.

F. Shi; X. Kong; F. Z. Cheng

2006-03-10T23:59:59.000Z

133

E-Print Network 3.0 - affects species abundances Sample Search...  

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

Density Dependence Shapes Species Abundances in a Tropical Tree Community Liza S. Comita,1... a species' relative abundance, but empirical tests are ... Source: Reich, Peter...

134

E-Print Network 3.0 - abundance element Sample Search Results  

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

160, 291- Summary: may have low abundances of high field strength elements, rare earth elements and Y. Variable vein... in subduction zones. However, abundance variations of...

135

Spatial Mapping of Protein Abundances in the Mouse Brain by Voxelation...  

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

Mapping of Protein Abundances in the Mouse Brain by Voxelation Integrated with High-Throughput Liquid Chromatography Spatial Mapping of Protein Abundances in the Mouse Brain by...

136

E-Print Network 3.0 - abundant culturable bacteria Sample Search...  

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

Sample search results for: abundant culturable bacteria Page: << < 1 2 3 4 5 > >> 1 ria and Virus Like Particles (VLPs) abundance were monitored in enriched seawater batch...

137

The effects of He I 10830 on helium abundance determinations  

E-Print Network [OSTI]

Observations of helium and hydrogen emission lines from metal-poor extragalactic H II regions provide an independent method for determining the primordial helium abundance, Y_p. Traditionally, the emission lines employed are in the visible wavelength range, and the number of suitable lines is limited. Furthermore, when using these lines, large systematic uncertainties in helium abundance determinations arise due to the degeneracy of physical parameters, such as temperature and density. Recently, Izotov, Thuan, & Guseva (2014) have pioneered adding the He 10830 infrared emission line in helium abundance determinations. The strong electron density dependence of He 10830 makes it ideal for better constraining density, potentially breaking the degeneracy with temperature. We revisit our analysis of the dataset published by Izotov, Thuan, & Stasinska (2007) and incorporate the newly available observations of He 10830 by scaling them using the observed-to-theoretical Paschen-gamma ratio. The solutions are b...

Aver, Erik; Skillman, Evan D

2015-01-01T23:59:59.000Z

138

What Is The Neon Abundance Of The Sun?  

E-Print Network [OSTI]

We have evolved a series of thirteen complete solar models that utilize different assumed heavy element compositions. Models that are based upon the heavy element abundances recently determined by Asplund, Grevesse, and Sauval (2005) are inconsistent with helioseismological measurements. However, models in which the neon abundance is increased by 0.4-0.5 dex to log N(Ne) = 8.29 +- 0.05 (on the scale in which log N(H) = 12) are consistent with the helioseismological measurements even though the other heavy element abundances are in agreement with the determinations of Asplund et al. (2005). These results sharpen and strengthen an earlier study by Antia and Basu (2005). The predicted solar neutrino fluxes are affected by the uncertainties in the composition by less than their 1sigma theoretical uncertainties.

John N. Bahcall; Sarbani Basu; Aldo M. Serenelli

2005-05-16T23:59:59.000Z

139

The chemical abundances of the Ap star HD94660  

SciTech Connect (OSTI)

In this work I present the determination of chemical abundances of the Ap star HD94660, a possible rapid oscillating star. As all the magnetic chemically peculiar objects, it presents CNO underabundance and overabundance of iron peak elements of ?100 times and of rare earths up to 4 dex with respect to the Sun. The determination was based on the conversion of the observed equivalent widths into abundances simultaneously to the determination of effective temperature and gravity. Since the Balmer lines of early type stars are very sensitive to the surface gravity while the flux distribution is sensitive to the effective temperature, I have adopted an iterative procedure to match the H{sub ?} line profile and the observed UV-Vis-NIR magnitudes of HD94660 looking for a consistency between the metallicity of the atmosphere model and the derived abundances. From my spectroscopic analysis, this star belongs to the no-rapid oscillating class.

Giarrusso, M. [Università di Catania, Dipartimento di Fisica e Astronomia, Sezione Astrofisica, Via S. Sofia 78, 95123 Catania (Italy); INAF - Osservatorio Astrofisico di Catania, via S. Sofia 78, 95123 Catania (Italy); INFN - Laboratori Nazionali del Sud (Italy)

2014-05-09T23:59:59.000Z

140

DETERMINING THE INITIAL HELIUM ABUNDANCE OF THE SUN  

SciTech Connect (OSTI)

We determine the dependence of the initial helium abundance and the present-day helium abundance in the convective envelope of solar models (Y {sub ini} and Y {sub surf}, respectively) on the parameters that are used to construct the models. We do so by using reference standard solar models (SSMs) to compute the power-law coefficients of the dependence of Y {sub ini} and Y {sub surf} on the input parameters. We use these dependencies to determine the correlation between Y {sub ini} and Y {sub surf} and use this correlation to eliminate uncertainties in Y {sub ini} from all solar model input parameters except the microscopic diffusion rate. We find an expression for Y {sub ini} that depends only on Y {sub surf} and the diffusion rate. By adopting the helioseismic determination of solar surface helium abundance, Y {sup surf} {sub sun} = 0.2485 {+-} 0.0035, and an uncertainty of 20% for the diffusion rate, we find that the initial solar helium abundance, Y {sup ini} {sub sun}, is 0.278 {+-} 0.006 independently of the reference SSMs (and particularly on the adopted solar abundances) used in the derivation of the correlation between Y {sub ini} and Y {sub surf}. When non-SSMs with extra mixing are used, then we derive Y {sup ini} {sub sun} = 0.273 {+-} 0.006. In both cases, the derived Y {sup ini} {sub sun} value is higher than that directly derived from solar model calibrations when the low-metallicity solar abundances (e.g., by Asplund et al.) are adopted in the models.

Serenelli, Aldo M. [Max Planck Institute for Astrophysics, Karl Schwarzschild Str. 1, Garching D-85471 (Germany); Basu, Sarbani, E-mail: aldos@mpa-garching.mpg.d [Department of Astronomy, Yale University, P.O. Box 208101, New Haven, CT 06520-8101 (United States)

2010-08-10T23:59:59.000Z

Note: This page contains sample records for the topic "natural abundance half-life" 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.


141

Quantum statistical calculation of cluster abundances in hot dense matter  

E-Print Network [OSTI]

The cluster abundances are calculated from a quantum statistical approach taking into account in-medium corrections. For arbitrary cluster size the self-energy and Pauli blocking shifts are considered. Exploratory calculations are performed for symmetric matter at temperature $T=5$ MeV and baryon density $\\varrho=0.0156$ fm$^{-3}$ to be compared with the solar element distribution. It is shown that the abundances of weakly bound nuclei with mass number $4

Gerd Ropke

2014-07-01T23:59:59.000Z

142

The Formation of the First Low-Mass Stars From Gas With Low Carbon and Oxygen Abundances  

E-Print Network [OSTI]

The first stars in the Universe are predicted to have been much more massive than the Sun. Gravitational condensation accompanied by cooling of the primordial gas due to molecular hydrogen, yields a minimum fragmentation scale of a few hundred solar masses. Numerical simulations indicate that once a gas clump acquires this mass, it undergoes a slow, quasi-hydrostatic contraction without further fragmentation. Here we show that as soon as the primordial gas - left over from the Big Bang - is enriched by supernovae to a carbon or oxygen abundance as small as ~0.01-0.1% of that found in the Sun, cooling by singly-ionized carbon or neutral oxygen can lead to the formation of low-mass stars. This mechanism naturally accommodates the discovery of solar mass stars with unusually low (10^{-5.3} of the solar value) iron abundance but with a high (10^{-1.3} solar) carbon abundance. The minimum stellar mass at early epochs is partially regulated by the temperature of the cosmic microwave background. The derived critical abundances can be used to identify those metal-poor stars in our Milky Way galaxy with elemental patterns imprinted by the first supernovae.

Volker Bromm; Abraham Loeb

2003-10-21T23:59:59.000Z

143

INTRODUCTION Information on the abundance of large whales in Greenland  

E-Print Network [OSTI]

INTRODUCTION Information on the abundance of large whales in Greenland waters, including fin whales surveys were conducted in West Greenland by the Greenland Fisheries Research Institute (m/v Regina Maris when survey conditions are optimal in Greenlandic waters. Between 1983 and 1993, visual aerial surveys

Laidre, Kristin L.

144

Carbon Abundances in the Galactic Thin and Thick Disks  

E-Print Network [OSTI]

Although carbon is, together with oxygen and nitrogen, one of the most important elements in the study of galactic chemical evolution its production sites are still poorly known and have been much debated (see e.g. Gustafsson et al. 1999; Chiappini et al. 2003). To trace the origin and evolution of carbon we have determined carbon abundances from the forbidden [C I] line at 8727 A and made comparisons to oxygen abundances from the forbidden [O I] line at 6300 A in a sample of 51 nearby F and G dwarf stars. These data and the fact that the forbidden [C I] and [O I] lines are very robust abundance indicators (they are essentially insensitive to deviations from LTE and uncertainties in the stellar parameters, see, e.g., Gustafsson et al. 1999; Asplund et al. 2005) enable us to very accurately measure the C/O ratio as well as individual C and O abundances. Our first results indicate that the time-scale for the main source that contribute to the carbon enrichment of the interstellar medium operate on the same time-scale as those that contribute to the iron enrichment (and can possibly be AGB stars...)

T. Bensby; S. Feltzing

2005-06-07T23:59:59.000Z

145

abundant nuclear copies: Topics by E-print Network  

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

abundant nuclear copies First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Author's personal copy Nuclear...

146

Asteroseismic determination of helium abundance in stellar envelopes  

E-Print Network [OSTI]

Intermediate degree modes of the solar oscillations have previously been used to determine the solar helium abundance to a high degree of precision. However, we cannot expect to observe such modes in other stars. In this work we investigate whether low degree modes that should be available from space-based asteroseismology missions can be used to determine the helium abundance, Y, in stellar envelopes with sufficient precision. We find that the oscillatory signal in the frequencies caused by the depression in \\Gamma_1 in the second helium ionisation zone can be used to determine the envelope helium abundance of low mass main sequence stars. For frequency errors of 1 part in 10^4, we expect errors \\sigma_Y in the estimated helium abundance to range from 0.03 for 0.8M_sun stars to 0.01 for 1.2M_sun stars. The task is more complicated in evolved stars, such as subgiants, but is still feasible if the relative errors in the frequencies are less than 10^{-4}.

Sarbani Basu; Anwesh Mazumdar; H. M Antia; Pierre Demarque

2004-02-15T23:59:59.000Z

147

Coronae of Stars with Super Solar Elemental Abundances  

E-Print Network [OSTI]

Coronal elemental abundances are known to deviate from the photospheric values of their parent star, with the degree of deviation depending on the First Ionization Potential (FIP). This study focuses on the coronal composition of stars with super-solar photospheric abundances. We present the coronal abundances of six such stars: 11 LMi, $\\iota$ Hor, HR 7291, $\\tau$ Boo, and $\\alpha$ Cen A and B. These stars all have high-statistics X-ray spectra, three of which are presented for the first time. The abundances measured in this paper are obtained using the line-resolved spectra of the Reflection Grating Spectrometer (RGS) in conjunction with the higher throughput EPIC-pn camera spectra on board the XMM-Newton observatory. A collisionally ionized plasma model with two or three temperature components is found to represent the spectra well. All elements are found to be consistently depleted in the coronae compared to their respective photospheres. For 11 LMi and $\\tau$ Boo no FIP effect is present, while $\\iota$ H...

Peretz, Uria; Drake, Stephen A

2015-01-01T23:59:59.000Z

148

Constraining dark energy from the abundance of weak gravitational lenses  

E-Print Network [OSTI]

We examine the prospect of using the observed abundance of weak gravitational lenses to constrain the equation-of-state parameter w of the dark energy. Here we solve the spherical-collapse model with dark energy, clarifying some ambiguities found in the literature, and provide fitting formulas for the overdensity at virialization and the linear-theory overdensity at collapse. We then compute the variation in the predicted weak-lens abundance with w. We find that the predicted redshift distribution and number count of weak lenses are highly degenerate in w and \\Omega_0. If we fix \\Omega_0 the number count for w=-2/3 is a factor of 2 smaller than for the \\LambdaCDM model. However, if we allow \\Omega_0 to vary with w such that the amplitude of the matter power spectrum as measured by COBE matches that obtained from the X-ray cluster abundance, the decrease in the predicted lens abundance is less than 25% for -1 40 degree^2 in order for the number count to differentiate a \\LambdaCDM cosmology from a w=-0.9 model...

Weinberg, N N; Weinberg, Nevin N.; Kamionkowski, Marc

2003-01-01T23:59:59.000Z

149

Harvard Medical School AbundanceFound Global Health  

E-Print Network [OSTI]

of post residency work primarily centered in global health delivery will receive 40% of the total awardHarvard Medical School AbundanceFound Global Health Loan Forgiveness Program for Graduating who have an intention of pursuing careers in global health delivery. This program is designed

Lahav, Galit

150

Implications of Elemental Abundances in Dwarf Spheroidal Galaxies  

E-Print Network [OSTI]

Unusual elemental abundance patterns observed for stars belonging to nearby dwarf spheroidal (dSph) galaxies are discussed. Analysis of the [alpha/H] vs. [Fe/H] diagrams where alpha represents Mg or average of alpha-elements reveals that Fe from Type Ia supernovae (SNe Ia) does not contribute to the stellar abundances in the dSph galaxies where the member stars exhibit low alpha/Fe ratios except for the most massive dSph galaxy, the Sagitarrius. The more massive dwarf (irregular) galaxy, the Large Magellanic Cloud, also have an SNe Ia signature in the stellar abundances. These findings suggest that the condition of whether SNe Ia contribute to chemical evolution in dwarf galaxies is likely to depend on the mass scale of galaxies. Unusual Mg abundances in some dSph stars are also found to be the origin of the large scatter in the [Mg/Fe] ratios and responsible for a seemingly decreasing [Mg/Fe] feature with increasing [Fe/H]. In addition, the lack of massive stars in the dSph galaxies does not satisfactorily account for the low-alpha signature. Considering the assemblage of deficient elements (O, Mg, Si, Ca, Ti, and Zn), all of which are synthesized in pre-SN massive stars and in SN explosions, the low-alpha signature appears to reflect the heavy-element yields of massive stars with smaller rotation compared to solar neighborhood stars.

Takuji Tsujimoto

2005-09-29T23:59:59.000Z

151

Implications of Elemental Abundances in Dwarf Spheroidal Galaxies  

E-Print Network [OSTI]

Unusual elemental abundance patterns observed for stars belonging to nearby dwarf spheroidal (dSph) galaxies are discussed. Analysis of the [alpha/H] vs. [Fe/H] diagrams where alpha represents Mg or average of alpha-elements reveals that Fe from Type Ia supernovae (SNe Ia) does not contribute to the stellar abundances in the dSph galaxies where the member stars exhibit low alpha/Fe ratios except for the most massive dSph galaxy, the Sagitarrius. The more massive dwarf (irregular) galaxy, the Large Magellanic Cloud, also have an SNe Ia signature in the stellar abundances. These findings suggest that the condition of whether SNe Ia contribute to chemical evolution in dwarf galaxies is likely to depend on the mass scale of galaxies. Unusual Mg abundances in some dSph stars are also found to be the origin of the large scatter in the [Mg/Fe] ratios and responsible for a seemingly decreasing [Mg/Fe] feature with increasing [Fe/H]. In addition, the lack of massive stars in the dSph galaxies does not satisfactorily a...

Tsujimoto, T

2005-01-01T23:59:59.000Z

152

abundant energy source: Topics by E-print Network  

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

abundant energy source First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 The SolarWiki Solar energy is...

153

Planning Amid Abundance: Alaska’s FY 2013 Budget Process  

E-Print Network [OSTI]

heavy oil, natural gas and shale oil. Fiscal stability wasshale formations could contain two billion barrels of oil and

McBeath, Jerry

2013-01-01T23:59:59.000Z

154

NATURAL GAS MARKET ASSESSMENT  

E-Print Network [OSTI]

CALIFORNIA ENERGY COMMISSION NATURAL GAS MARKET ASSESSMENT PRELIMINARY RESULTS In Support.................................................................................... 6 Chapter 2: Natural Gas Demand.................................................................................................. 10 Chapter 3: Natural Gas Supply

155

Distribution and Abundance Patterns of Spiders Inhabiting Cotton in Texas.  

E-Print Network [OSTI]

. L. Sterling Department of Entomology Texas A&M University Abstract Patterns of the distribution and abundance of spiders were determined in the major cotton growing areas of Texas during 1982-83. M isumenops spp., Oxyopes saiticus Hentz... to predict this neutrality is important since spiders could then be eliminated as an important factor in predicting the dynamics of other arthropods. The cotton fleahopper (Pseudatomoscelis seriatus [Reuter]) model (Hartstack and Sterling 1986) uses...

Dean, D.A.; Sterling, W.L.

1987-01-01T23:59:59.000Z

156

CHEMICAL ABUNDANCE PATTERNS AND THE EARLY ENVIRONMENT OF DWARF GALAXIES  

SciTech Connect (OSTI)

Recent observations suggest that abundance pattern differences exist between low metallicity stars in the Milky Way stellar halo and those in the dwarf satellite galaxies. This paper takes a first look at what role the early environment for pre-galactic star formation might have played in shaping these stellar populations. In particular, we consider whether differences in cross-pollution between the progenitors of the stellar halo and the satellites could help to explain the differences in abundance patterns. Using an N-body simulation, we find that the progenitor halos of the main halo are primarily clustered together at z = 10 while the progenitors of the satellite galaxies remain on the outskirts of this cluster. Next, analytically modeled supernova-driven winds show that main halo progenitors cross-pollute each other more effectively while satellite galaxy progenitors remain more isolated. Thus, inhomogeneous cross-pollution as a result of different high-z spatial locations of each system's progenitors can help to explain observed differences in abundance patterns today. Conversely, these differences are a signature of the inhomogeneity of metal enrichment at early times.

Corlies, Lauren; Johnston, Kathryn V.; Bryan, Greg [Department of Astronomy, Columbia University, New York, NY 10027 (United States); Tumlinson, Jason [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD (United States)

2013-08-20T23:59:59.000Z

157

THE RAVE CATALOG OF STELLAR ELEMENTAL ABUNDANCES: FIRST DATA RELEASE  

SciTech Connect (OSTI)

We present chemical elemental abundances for 36,561 stars observed by the RAdial Velocity Experiment (RAVE), an ambitious spectroscopic survey of our Galaxy at Galactic latitudes |b| > 25 Degree-Sign and with magnitudes in the range 9 abundances for the elements Mg, Al, Si, Ca, Ti, Fe, and Ni, with a mean error of {approx}0.2 dex, as judged from accuracy tests performed on synthetic and real spectra. Abundances are estimated through a dedicated processing pipeline in which the curve of growth of individual lines is obtained from a library of absorption line equivalent widths to construct a model spectrum that is then matched to the observed spectrum via a {chi}{sup 2} minimization technique. We plan to extend this pipeline to include estimates for other elements, such as oxygen and sulfur, in future data releases.

Boeche, C.; Williams, M.; De Jong, R. S.; Steinmetz, M. [Leibniz-Institut fuer Astrophysik Potsdam (AIP), D-14482 Potsdam (Germany); Siebert, A.; Bienayme, O. [Observatoire Astronomique de Strasbourg, Universite de Strasbourg, CNRS, UMR 7550, F-67000 Strasbourg (France); Fulbright, J. P.; Ruchti, G. R. [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States); Bland-Hawthorn, J. [Sydney Institute for Astronomy, School of Physics A28, University of Sydney, NSW 2006 (Australia); Campbell, R. [Department of Physics and Astronomy, Western Kentucky University, Bowling Green, KY (United States); Freeman, K. C. [Research School of Astronomy and Astrophysics, Australia National University, Weston Creek, Canberra ACT 2611 (Australia); Gibson, B. K. [Jeremiah Horrocks Institute, University of Central Lancashire, Preston PR1 2HE (United Kingdom); Gilmore, G. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Grebel, E. K. [Astronomisches Rechen-Institut, Zentrum fuer Astronomie der Universitaet Heidelberg, D-69120 Heidelberg (Germany); Helmi, A. [Kapteyn Astronomical Institute, University of Groningen, 9700 AV Groningen (Netherlands); Munari, U. [INAF Osservatorio Astronomico di Padova, Asiago I-36012 (Italy); Navarro, J. F. [Department of Physics and Astronomy, University of Victoria, Victoria BC V8W 3P6 (Canada); Parker, Q. A.; Reid, W. [Department of Physics and Astronomy, Faculty of Sciences, Macquarie University, Sydney, NSW 2109 (Australia); Seabroke, G. M. [Mullard Space Science Laboratory, University College London, Holmbury, St. Mary RH5 6NT (United Kingdom); and others

2011-12-15T23:59:59.000Z

158

Oxygen abundance methods in the SDSS: view from modern statistics  

E-Print Network [OSTI]

Our purpose is to find which is the most reliable one among various oxygen abundance determination methods. We will test the validity of several different oxygen abundance determination methods using methods of modern statistics. These methods include Bayesian analysis and information scoring. We will analyze a sample of $\\sim$6000 $\\hii$ galaxies from the Sloan Digital Sky Survey (SDSS) spectroscopic observations data release four. All methods that we used drew the same conclusion that the $T_e$ method is a more reliable oxygen abundance determination methods than the Bayesian metallcity method under the existing telescope ability. The ratios of the likelihoods between the different kinds of methods tell us that the $T_e$, $P$, and $O3N2$ methods are consistent with each other because the $P$ and $O3N2$ method are calibrated by $T_e$-method. The Bayesian and $R_{23}$ method are consistent with each other because both are calibrated by a galaxy model. In either case, the $N2$ method is an {\\it unreliable} method.

F. Shi; G. Zhao; James Wicker

2007-10-24T23:59:59.000Z

159

Record of Cycling Operation of the Natural Nuclear Reactor in the Oklo/Okelobondo Area in Gabon  

E-Print Network [OSTI]

Record of Cycling Operation of the Natural Nuclear Reactor in the Oklo/Okelobondo Area in Gabon A billion yr old Oklo natural nuclear reactor. In addition to elevated abundances of fission-produced Zr, Ce nuclear chain reaction was predicted by Kuroda [1] 20 years before the remnants of the natural reactor

160

The Formation of the First Low-Mass Stars From Gas With Low Carbon and Oxygen Abundances  

E-Print Network [OSTI]

The first stars in the Universe are predicted to have been much more massive than the Sun. Gravitational condensation accompanied by cooling of the primordial gas due to molecular hydrogen, yields a minimum fragmentation scale of a few hundred solar masses. Numerical simulations indicate that once a gas clump acquires this mass, it undergoes a slow, quasi-hydrostatic contraction without further fragmentation. Here we show that as soon as the primordial gas - left over from the Big Bang - is enriched by supernovae to a carbon or oxygen abundance as small as ~0.01-0.1% of that found in the Sun, cooling by singly-ionized carbon or neutral oxygen can lead to the formation of low-mass stars. This mechanism naturally accommodates the discovery of solar mass stars with unusually low (10^{-5.3} of the solar value) iron abundance but with a high (10^{-1.3} solar) carbon abundance. The minimum stellar mass at early epochs is partially regulated by the temperature of the cosmic microwave background. The derived critical...

Bromm, V; Bromm, Volker; Loeb, Abraham

2003-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "natural abundance half-life" 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

Re-examining High Abundance SDSS Mass-Metallicity Outliers: High N/O, Evolved Wolf-Rayet Galaxies?  

E-Print Network [OSTI]

We present new MMT spectroscopic observations of four dwarf galaxies representative of a larger sample observed by the Sloan Digital Sky Survey (SDSS) and identified by Peeples et al. (2008) as low-mass, high oxygen abundance outliers from the mass-metallicity relation. Peeples et al. (2008) showed that these four objects (with metallicity estimates of 8.5 =~ 0.10), each of which tend to bias estimates based on strong emission lines toward high oxygen abundances. These spectra all fall in a regime where the "standard" strong line methods for metallicity determinations are not well calibrated either empirically or by photoionization modeling. By comparing our spectra directly to photoionization models, we estimate oxygen abundances in the range of 7.9 =< 12 + log(O/H) =< 8.4, consistent with the scatter of the mass-metallicity relation. We discuss the physical nature of these galaxies that leads to their unusual spectra (and previous classification as outliers), finding their low excitation, elevated N/O...

Berg, Danielle A; Marble, Andrew R

2011-01-01T23:59:59.000Z

162

Global climatology of abundance and solar absorption of oxygen collision complexes  

E-Print Network [OSTI]

the atmosphere by ZENDER: CLIMATOLOGY OF O2-X ABUNDANCE ANDOCTOBER 27, 1999 Global climatology of abundance and solarWe create a global climatology of well—mixed collision

Zender, Charles S.

1999-01-01T23:59:59.000Z

163

Region-Specific Protein Abundance Changes in the Brain of MPTP...  

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

Region-Specific Protein Abundance Changes in the Brain of MPTP-induced Parkinson’s Disease Mouse Model . Region-Specific Protein Abundance Changes in the Brain of...

164

Abundances of metal-weak thick-disc candidates  

E-Print Network [OSTI]

High resolution spectra of 5 candidate metal-weak thick-disc stars suggested by Beers & Sommer-Larsen (1995) are analyzed to determine their chemical abundances. The low abundance of all the objects has been confirmed with metallicity reaching [Fe/H]=-2.9. However, for three objects, the astrometric data from the Hipparcos catalogue suggests they are true halo members. The remaining two, for which proper-motion data are not available, may have disc-like kinematics. It is therefore clear that it is useful to address properties of putative metal-weak thick-disc stars only if they possess full kinematic data. For CS 22894-19 the abundance pattern similar to those of typical halo stars is found, suggesting that chemical composition is not a useful discriminant between thick-disc and halo stars. CS 29529-12 is found to be C enhanced with [C/Fe]=+1.0; other chemical peculiarities involve the s process elements: [Sr/Fe]=-0.65 and [Ba/Fe]=+0.62, leading to a high [Ba/Sr] considerably larger than what is found in more metal-rich carbon-rich stars, but similar to LP 706-7 and LP 625-44 discussed by Norris et al (1997a). Hipparcos data have been used to calculate the space velocities of 25 candidate metal-weak thick-disc stars, thus allowing us to identify 3 bona fide members, which support the existence of a metal-poor tail of the thick-disc, at variance with a claim to the contrary by Ryan & Lambert (1995).

P. Bonifacio; M. Centurion; P. Molaro

1999-06-03T23:59:59.000Z

165

DIVERSITY OF TYPE Ia SUPERNOVAE IMPRINTED IN CHEMICAL ABUNDANCES  

SciTech Connect (OSTI)

A time delay of Type Ia supernova (SN Ia) explosions hinders the imprint of their nucleosynthesis on stellar abundances. However, some occasional cases give birth to stars that avoid enrichment of their chemical compositions by massive stars and thereby exhibit an SN-Ia-like elemental feature including a very low [Mg/Fe] ( Almost-Equal-To - 1). We highlight the elemental feature of Fe-group elements for two low-Mg/Fe objects detected in nearby galaxies, and propose the presence of a class of SNe Ia that yield the low abundance ratios of [Cr, Mn, Ni/Fe]. Our novel models of chemical evolution reveal that our proposed class of SNe Ia (slow SNe Ia) is associated with ones exploding on a long timescale after their stellar birth and give a significant impact on the chemical enrichment in the Large Magellanic Cloud (LMC). In the Galaxy, on the other hand, this effect is unseen due to the overwhelming enrichment by the major class of SNe Ia that explode promptly (prompt SNe Ia) and eject a large amount of Fe-group elements. This nicely explains the different [Cr, Mn, Ni/Fe] features between the two galaxies as well as the puzzling feature seen in the LMC stars exhibiting very low Ca but normal Mg abundances. Furthermore, the corresponding channel of slow SN Ia is exemplified by performing detailed nucleosynthesis calculations in the scheme of SNe Ia resulting from a 0.8 + 0.6 M{sub Sun} white dwarf merger.

Tsujimoto, Takuji [National Astronomical Observatory of Japan, Mitaka-shi, Tokyo 181-8588 (Japan); Shigeyama, Toshikazu, E-mail: taku.tsujimoto@nao.ac.jp [Research Center for the Early Universe, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)

2012-12-01T23:59:59.000Z

166

Abundance profile and stellar content of IZw18  

E-Print Network [OSTI]

New spectroscopic observations of the metal poor galaxy IZw 18 are discussed. Wolf-Rayet stars of WC type have been detected in the NW-HII region contrary to evolutionary synthesis model predictions. Implications on the mass loss rate and on the formation processes of WR stars are discussed. A very homogeneous metal abundance is observed within the HII region. This emphasizes the problem of the dispersal and mixing of new synthesized element in a starburst. Different scenarios are discussed, showing that metals remain most likely hidden in a hot phase and that the observed present metallicity is the result of a previous star formation event.

F. Legrand

1997-12-08T23:59:59.000Z

167

Remarkable Amphibian Biomass and Abundance in an Isolated Wetland: Implications for Wetland  

E-Print Network [OSTI]

-1739.2006.00443.x #12;1458 Amphibian Biomass and Abundance Gibbons et al. Biomasa y Abundancia de Anfibios

Georgia, University of

168

Non-LTE Abundances of Magnesium, Aluminum and Sulfur in OB Stars Near the Solar Circle  

E-Print Network [OSTI]

Non-LTE abundances of magnesium, aluminum and sulfur are derived for a sample of 23 low-v \\sin i stars belonging to six northern OB associations of the Galactic disk within 1 kpc of the Sun. The abundances are obtained from the fitting of synthetic line profiles to high resolution spectra. A comparison of our results with HII region abundances indicates good agreement for sulfur while the cepheid abundances are higher. The derived abundances of Mg show good overlap with the cepheid results. The aluminum abundances for OB stars are significantly below the cepheid values. But, the OB star results show a dependence with effective temperature and need further investigation. The high Al abundances in the cepheids could be the result of mixing. A discussion of the oxygen abundance in objects near the solar circle suggests that the current mean galactic oxygen abundance in this region is 8.6-8.7 and in agreement with the recently revised oxygen abundance in the solar photosphere. Meaningful comparisons of the absolute S, Al and Mg abundances in OB stars with the Sun must await a reinvestigation of these elements, as well as the meteoritic reference element Si, with 3D hydrodynamical model atmospheres for the Sun. No abundance gradients are found within the limited range in galactocentric distances in the present study. Such variations would be expected only if there were large metallicity gradients in the disk.

S. Daflon; K. Cunha; V. V. Smith; K. Butler

2002-12-09T23:59:59.000Z

169

OXYGEN GAS-PHASE ABUNDANCE REVISITED M. K. Andre,1,2  

E-Print Network [OSTI]

OXYGEN GAS-PHASE ABUNDANCE REVISITED M. K. Andre´,1,2 C. M. Oliveira,2 J. C. Howk,2 R. Ferlet,1 J gas-phase oxygen abundance along the sight lines toward 19 early-type Galactic stars at an average mag�1 with a standard deviation of 15% is consistent with previous surveys. The mean oxygen abundance

Howk, Jay Christopher

170

Lithium abundances in exoplanet-host stars : modelling  

E-Print Network [OSTI]

Aims. Exoplanet-host stars (EHS) are known to present superficial chemical abundances different from those of stars without any detected planet (NEHS). EHS are, on the average, overmetallic compared to the Sun. The observations also show that, for cool stars, lithium is more depleted in EHS than in NEHS. The aim of this paper is to obtain constraints on possible models able to explain this difference, in the framework of overmetallic models compared to models with solar abundances. Methods. We have computed main sequence stellar models with various masses and metallicities. The results show different behaviour for the lithium destruction according to those parameters. We compare these results to the spectroscopic observations of lithium. Results. Our models show that the observed lithium differences between EHS and NEHS are not directly due to the overmetallicity of the EHS: some extra mixing is needed below the convective zones. We discuss possible explanations for the needed extra mixing, in particular an increase of the mixing efficiency associated with the development of shear instabilities below the convective zone, triggered by angular momentum transfer due to the planetary migration.

M. Castro; S. Vauclair; O. Richard; N. C. Santos

2008-11-18T23:59:59.000Z

171

Elemental Abundances from Intrinsic QSO Emission and Absorption Lines  

E-Print Network [OSTI]

Several studies have shown that the column densities inferred from broad absorption lines (BALs) require extremely high metallicities and phosphorus overabundances -- apparently in conflict with other abundance diagnostics. Here I use HST spectroscopy of the BALQSO PG 1254+047 to argue that the BALs abundance estimates are incorrect, because partial line-of-sight coverage of the continuum source(s) has led to gross underestimates of the line optical depths and column densities. I claim that the significant presence of PV 1118,1128 absorption in this and other BALQSOs identifies the saturated absorption-line spectrum. This interpretation implies that the total column densities are at least ten times larger than previous estimates, namely log N_H(cm-2) > 22. The outflowing BAL gas, at velocities from -15,000 to -27,000 km/s in PG 1254+047, is therefore a strong candidate for the X-ray absorber in BALQSOs. If this high-column density outflow is radiately accelerated, it must originate <0.1 pc from the QSO.

F. Hamann

1998-06-06T23:59:59.000Z

172

Diversity of Type Ia Supernovae Imprinted in Chemical Abundances  

E-Print Network [OSTI]

A time delay of Type Ia supernova (SN Ia) explosions hinders the imprint of their nucleosynthesis on stellar abundances. However, some occasional cases give birth to stars that avoid enrichment of their chemical compositions by massive stars and thereby exhibit a SN Ia-like elemental feature including a very low [Mg/Fe] (~-1). We highlight the elemental feature of Fe-group elements for two low-Mg/Fe objects detected in nearby galaxies, and propose the presence of a class of SNe Ia that yield the low abundance ratios of [Cr,Mn,Ni/Fe]. Our novel models of chemical evolution reveal that our proposed class of SNe Ia (slow SNe Ia) is associated with ones exploding on a long timescale after their stellar birth, and gives a significant impact on the chemical enrichment in the Large Magellanic Cloud (LMC). In the Galaxy, on the other hand, this effect is unseen due to the overwhelming enrichment by the major class of SNe Ia that explode promptly (prompt SNe Ia) and eject a large amount of Fe-group elements. This nice...

Tsujimoto, Takuji

2012-01-01T23:59:59.000Z

173

The element abundance FIP effect in the quiet Sun  

E-Print Network [OSTI]

The Mg/Ne abundance ratio in the quiet Sun is measured in both network and supergranule cell centre regions through EUV spectra from the Coronal Diagnostic Spectrometer on SOHO. Twenty four sets of data over the period 1996 March to 1998 June (corresponding to solar minimum) are studied. Emission lines of the sequences Ne IV-VII and Mg V-VIII are simultaneously analysed by comparing with theoretical emissivities from the CHIANTI database to yield the Mg/Ne abundance and emission measure over the temperature region 5.0 Sun connects into the solar wind. The quiet Sun spectra are also utilised to determine the coronal density and temperature, leading to average values of 2.6^+0.5_-0.4 x 10^8 cm^-3 and log (T/K)=5.95 +/- 0.02. No significant trend with the rise in solar activity during 1996--98 is found for any of the derived quantities, implying that quiet Sun regions show little dependence on the solar cycle.

P. R. Young

2005-03-02T23:59:59.000Z

174

Planning Amid Abundance: Alaska’s FY 2013 Budget Process  

E-Print Network [OSTI]

on liquefied natural gas (LNG). He met with the Alaska CEOsof the companies’ position on LNG exports with the state’s (unclear whether a large LNG project would be feasible and

McBeath, Jerry

2013-01-01T23:59:59.000Z

175

An MCMC determination of the primordial helium abundance  

SciTech Connect (OSTI)

Spectroscopic observations of the chemical abundances in metal-poor H II regions provide an independent method for estimating the primordial helium abundance. H II regions are described by several physical parameters such as electron density, electron temperature, and reddening, in addition to y, the ratio of helium to hydrogen. It had been customary to estimate or determine self-consistently these parameters to calculate y. Frequentist analyses of the parameter space have been shown to be successful in these parameter determinations, and Markov Chain Monte Carlo (MCMC) techniques have proven to be very efficient in sampling this parameter space. Nevertheless, accurate determination of the primordial helium abundance from observations of H II regions is constrained by both systematic and statistical uncertainties. In an attempt to better reduce the latter, and continue to better characterize the former, we apply MCMC methods to the large dataset recently compiled by Izotov, Thuan, and Stasi?ska (2007). To improve the reliability of the determination, a high quality dataset is needed. In pursuit of this, a variety of cuts are explored. The efficacy of the He I ?4026 emission line as a constraint on the solutions is first examined, revealing the introduction of systematic bias through its absence. As a clear measure of the quality of the physical solution, a ?{sup 2} analysis proves instrumental in the selection of data compatible with the theoretical model. Nearly two-thirds of the observations fall outside a standard 95% confidence level cut, which highlights the care necessary in selecting systems and warrants further investigation into potential deficiencies of the model or data. In addition, the method also allows us to exclude systems for which parameter estimations are statistical outliers. As a result, the final selected dataset gains in reliability and exhibits improved consistency. Regression to zero metallicity yields Y{sub p} = 0.2534 ± 0.0083, in broad agreement with the WMAP result. The inclusion of more observations shows promise for further reducing the uncertainty, but more high quality spectra are required.

Aver, Erik; Olive, Keith A.; Skillman, Evan D., E-mail: aver@physics.umn.edu, E-mail: olive@umn.edu, E-mail: skillman@astro.umn.edu [School of Physics and Astronomy, University of Minnesota, 116 Church St. SE, Minneapolis, MN 55455 (United States)

2012-04-01T23:59:59.000Z

176

Carbon stars in local group dwarf galaxies: C and O abundances  

E-Print Network [OSTI]

We present abundances of carbon and oxygen as well as abundance ratios 12C/13C for a sample of carbon stars in the LMC, SMC, Carina, Sculptor and Fornax dwarf galaxies. The overall metallicities in these dwarf galaxies are lower than in the galactic disc. The observations cover most of the AGB and we discuss the abundance patterns in different regions along the AGB. The abundances are determined from infrared spectra obtained with the ISAAC spectrometer on VLT (R=1500) and the Phoenix Spectrometer on Gemini South (R=50000). The synthetic spectra used in the analysis were computed with MARCS model atmospheres. We find that the oxygen abundance is decreasing with decreasing overall metallicity of the system while the C/O ratio at a given evolutionary phase is increasing with decreasing oxygen abundance. keywords Stars: abundances -- Stars: carbon -- Stars: AGB and post-AGB -- Galaxies: dwarf -- Local Group -- Infrared: stars

R. Wahlin; K. Eriksson; B. Gustafsson; K. H. Hinkle; D. L. Lambert; N. Ryde; B. Westerlund

2006-05-10T23:59:59.000Z

177

The helium abundances in HgMn and normal stars  

E-Print Network [OSTI]

The parameter-free model of diffusion in the atmospheres of HgMn stars (Michaud 1986; Michaud et al 1979) predicts that helium should sink below the He II ionization zone in order that diffusion of other elements may take place, and that all HgMn stars should have deficits of helium in their photospheres, with a minimum deficit of 0.3 dex. In this study, the Smith & Dworetsky (1993) sample of HgMn stars and normal comparison stars is examined, and the helium abundances determined by spectrum synthesis using echelle spectra taken at Lick Observatory and the AAT. The prediction is confirmed; all HgMn stars are deficient in He by as much as 1.5 dex. Also, two HgMn stars, HR7361 and HR7664, show clear evidence of helium stratification.

M. M. Dworetsky

2004-07-26T23:59:59.000Z

178

Regulation of natural monopolies  

E-Print Network [OSTI]

This chapter provides a comprehensive overview of the theoretical and empirical literature on the regulation of natural monopolies. It covers alternative definitions of natural monopoly, regulatory goals, alternative ...

Joskow, Paul L.

2005-01-01T23:59:59.000Z

179

Historical Natural Gas Annual  

U.S. Energy Information Administration (EIA) Indexed Site

8 The Historical Natural Gas Annual contains historical information on supply and disposition of natural gas at the national, regional, and State level as well as prices at...

180

Historical Natural Gas Annual  

U.S. Energy Information Administration (EIA) Indexed Site

6 The Historical Natural Gas Annual contains historical information on supply and disposition of natural gas at the national, regional, and State level as well as prices at...

Note: This page contains sample records for the topic "natural abundance half-life" 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

Historical Natural Gas Annual  

U.S. Energy Information Administration (EIA) Indexed Site

7 The Historical Natural Gas Annual contains historical information on supply and disposition of natural gas at the national, regional, and State level as well as prices at...

182

Natural Gas Rules (Louisiana)  

Broader source: Energy.gov [DOE]

The Louisiana Department of Natural Resources administers the rules that govern natural gas exploration and extraction in the state. DNR works with the Louisiana Department of Environmental...

183

Natural Resources Districts (Nebraska)  

Broader source: Energy.gov [DOE]

This statute establishes Natural Resources District, encompassing all of the area of the state, to conserve, protect, develop, and manage Nebraska's natural resources. These districts replace and...

184

Commissioning of a magnetic suspension densitometer for high-accuracy density measurements of natural gas mixtures  

E-Print Network [OSTI]

of developing clean coal technology and its abundant, economical domestic sources made coal the focus of attention once again (Ferguson, 2002). The US DOE in conjunction with the industry initiated a research, development and demonstration (RD&D) program...). Until clean coal technologies mature to compete viably with natural gas, production of natural gas must be maintained or increased to avoid dependence upon imported petroleum oil. Although natural gas and coal may appear to rival each other in the mid...

Patil, Prashant Vithal

2009-05-15T23:59:59.000Z

185

Crystal Structure of an HSA/FcRn Complex Reveals Recycling by Competitive Mimicry of HSA Ligands at a pH-Dependent Hydrophobic Interface  

E-Print Network [OSTI]

The long circulating half-life of serum albumin, the most abundant protein in mammalian plasma, derives from pH-dependent endosomal salvage from degradation, mediated by the neonatal Fc receptor (FcRn). Using yeast display, ...

Schmidt, Michael M.

186

Pennsylvania's Natural Gas Future  

E-Print Network [OSTI]

1 Pennsylvania's Natural Gas Future Penn State Natural Gas Utilization Workshop Bradley Hall sales to commercial and industrial customers ­ Natural gas, power, oil · Power generation ­ FossilMMBtuEquivalent Wellhead Gas Price, $/MMBtu Monthly US Spot Oil Price, $/MMBtu* U.S. Crude Oil vs. Natural Gas Prices, 2005

Lee, Dongwon

187

Research Highlights Nature Nanotechnology  

E-Print Network [OSTI]

© 2009 APS Research Highlights Nature Nanotechnology Published online: 17 July 2009 | doi:10 perfect fluid. Phys. Rev. Lett. 103, 025301 (2009). | Article |1. Nature Nanotechnology ISSN 1748 : Nature Nanotechnology http://www.nature.com/nnano/reshigh/2009/0709/full/nnano.2009.222.html 1 of 1 18

Müller, Markus

188

Light-Element Abundances of Giant Stars in the Globular Cluster M71 (NGC 6838)  

E-Print Network [OSTI]

Aluminum is the heaviest light element displaying large star--to--star variations in Galactic globular clusters (GCs). This element may provide additional insight into the origin of the multiple populations now known to be a common place in GCs, and also the nature of the first-generation stars responsible for a cluster's chemical inhomogeneities. In a previous analysis we found that, unlike more metal-poor GCs, 47 Tuc did not exhibit a strong Na-Al correlation, which motivates a careful study of the similar metallicity but less massive GC M71. We present chemical abundances of O, Na, Al, and Fe for 33 giants in M71 using spectra obtained with the WIYN-Hydra spectrograph. Our spectroscopic analysis finds that, similar to 47 Tuc and in contrast with more metal-poor GCs, M71 stars do not exhibit a strong Na-Al correlation and span a relatively narrow range in [Al/Fe], which are characteristics that GC formation models must reproduce.

Cordero, Maria J; Johnson, Christian I; Vesperini, Enrico

2015-01-01T23:59:59.000Z

189

Measurement of the half-life of (198)Au in a nonmetal: High-precision measurement shows no host-material dependence  

E-Print Network [OSTI]

://www.ortec-online.com/Solutions/multichannel-analyzers. aspx]. [8] R. Jenkins, R. W. Gould, and D. Gedcke, Quantitative X-ray Spectrometry (Dekker, New York, 1981), p. 266. [9] D. Radford (private communication) [http://radware.phy. ornl.gov/main.html]. [10] R. Brun and F. Rademakers, Nucl. Instrum...

Goodwin, J. R.; Nica, N.; Iacob, V. E.; Dibidad, A.; Hardy, John C.

2010-01-01T23:59:59.000Z

190

THE FIRST ISOLATION OF AMERICIUM IN THE FORM OF PURE COMPOUNDS - THE SPECIFIC ALPHA-ACTIVITY AND HALF-LIFE OF Am241  

E-Print Network [OSTI]

eng-48 THE FIRST ISOLATION QF AMERICIUM IN THE FORM OF PURECalifornia July 20, 1950 l Americium was discovered inof the chemistry of americium were carried out by its

Cunningham, B.B.

2011-01-01T23:59:59.000Z

191

Natural gas monthly  

SciTech Connect (OSTI)

The Natural Gas Monthly highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the Natural Gas Monthly features articles designed to assist readers in using and interpreting natural gas information.

NONE

1998-01-01T23:59:59.000Z

192

The circulating hemocytes of the white shrimp, Penaeus setiferus: origin, abundance, morphology, and function  

E-Print Network [OSTI]

Approved as to style and content by: (Chairman of Committee) A. ~ (Head of Department) (Member) 4. ~6-&- (Member) May 1978 442840 ABSTBACT The Circulating Hemocytes of the Hhite Shrimp, Penacus setiferus: Origin, Abundance, Morphology.... EDGFuVENTS? LIST OF TABLES vii LIST OF FIGURES viii INTRODUCTION- RL'VIEN OF LITERATURE NATL'RIALS AND METHODS 01 igil'l Abundance Morphology? Function 13 13 14 15 18 RESULTS AND DISCUSSION 21 Origin 21 Abundance? 23 Morphology...

Fontaine, Clark Timothy

2012-06-07T23:59:59.000Z

193

Molecular hydrogen abundances of galaxies in the EAGLE simulations  

E-Print Network [OSTI]

We investigate the abundance of galactic molecular hydrogen (H$_2$) in the "Evolution and Assembly of GaLaxies and their Environments" (EAGLE) cosmological hydrodynamic simulations. We assign H$_2$ masses to gas particles in the simulations in post-processing using two different prescriptions that depend on the local dust-to-gas ratio and the interstellar radiation field. Both result in H$_2$ galaxy mass functions that agree well with observations in the local and high-redshift Universe. The simulations reproduce the observed scaling relations between the mass of H$_2$ and the stellar mass, star formation rate and stellar surface density. Towards high edshifts, galaxies in the simulations display larger H$_2$ mass fractions, and correspondingly lower H$_2$ depletion timescales, also in good agreement with observations. The comoving mass density of H$_2$ in units of the critical density, $\\Omega_{\\rm H_2}$, peaks at $z\\approx 1.2-1.5$, later than the predicted peak of the cosmic star formation rate activity, a...

Lagos, Claudia del P; Schaye, Joop; Furlong, Michelle; Frenk, Carlos S; Bower, Richard G; Schaller, Matthieu; Theuns, Tom; Trayford, James W; Bahe, Yannick M; Vecchia, Claudio Dalla

2015-01-01T23:59:59.000Z

194

Low 60Fe abundance in Semarkona and Sahara 99555  

E-Print Network [OSTI]

Iron-60 (t1/2=2.62 Myr) is a short-lived nuclide that can help constrain the astrophysical context of solar system formation and date early solar system events. A high abundance of 60Fe (60Fe/56Fe= 4x10-7) was reported by in situ techniques in some chondrules from the LL3.00 Semarkona meteorite, which was taken as evidence that a supernova exploded in the vicinity of the birthplace of the Sun. However, our previous MC-ICPMS measurements of a wide range of meteoritic materials, including chondrules, showed that 60Fe was present in the early solar system at a much lower level (60Fe/56Fe=10-8). The reason for the discrepancy is unknown but only two Semarkona chondrules were measured by MC-ICPMS and these had Fe/Ni ratios below ~2x chondritic. Here, we show that the initial 60Fe/56Fe ratio in Semarkona chondrules with Fe/Ni ratios up to ~24x chondritic is 5.4x10-9. We also establish the initial 60Fe/56Fe ratio at the time of crystallization of the Sahara 99555 angrite, a chronological anchor, to be 1.97x10-9. The...

Tang, Haolan

2015-01-01T23:59:59.000Z

195

The Water Vapor Abundance in Orion KL Outflows  

E-Print Network [OSTI]

We present the detection and modeling of more than 70 far-IR pure rotational lines of water vapor, including the 18O and 17O isotopologues, towards Orion KL. Observations were performed with the Long Wavelength Spectrometer Fabry-Perot (LWS/FP; R~6800-9700) on board the Infrared Space Observatory (ISO) between ~43 and ~197 um. The water line profiles evolve from P-Cygni type profiles (even for the H2O18 lines) to pure emission at wavelengths above ~100 um. We find that most of the water emission/absorption arises from an extended flow of gas expanding at 25+-5 kms^-1. Non-local radiative transfer models show that much of the water excitation and line profile formation is driven by the dust continuum emission. The derived beam averaged water abundance is 2-3x10^-5. The inferred gas temperature Tk=80-100 K suggests that: (i) water could have been formed in the "plateau" by gas phase neutral-neutral reactions with activation barriers if the gas was previously heated (e.g. by shocks) to >500 K and/or (ii) H2O formation in the outflow is dominated by in-situ evaporation of grain water-ice mantles and/or (iii) H2O was formed in the innermost and warmer regions (e.g. the hot core) and was swept up in ~1000 yr, the dynamical timescale of the outflow.

J. Cernicharo; J. R. Goicoechea; F. Daniel; M. R. Lerate; M. J. Barlow; B. M. Swinyard; E. van Dishoeck; T. L. Lim; S. Viti; J. Yates

2006-08-16T23:59:59.000Z

196

The Coronal Abundances of Mid-F Dwarfs  

E-Print Network [OSTI]

A Chandra spectrum of the moderately active nearby F6 V star Pi3 Ori is used to study the coronal properties of mid-F dwarfs. We find that Pi3 Ori's coronal emission measure distribution is very similar to those of moderately active G and K dwarfs, with an emission measure peak near $\\log T=6.6$ seeming to be ubiquitous for such stars. In contrast to coronal temperature, coronal abundances are known to depend on spectral type for main sequence stars. Based on this previously known relation, we expected Pi3 Ori's corona to exhibit an extremely strong "FIP effect," a phenomenon first identified on the Sun where elements with low "First Ionization Potential" (FIP) are enhanced in the corona. We instead find that Pi3 Ori's corona exhibits a FIP effect essentially identical to that of the Sun and other early G dwarfs, perhaps indicating that the increase in FIP bias towards earlier spectral types stops or at least slows for F stars. We find that Pi3 Ori's coronal characteristics are significantly different from tw...

Wood, Brian E

2013-01-01T23:59:59.000Z

197

E-Print Network 3.0 - abundance age size Sample Search Results  

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

highly correlated with spawning stock size (Fig. 1A... herring abundance index for the North Sea, the larval production estimate, utilizes all size and age... attain a maximum...

198

Parent Stars of Extrasolar Planets. VIII. Chemical Abundances for 18 Elements in 31 Stars  

E-Print Network [OSTI]

We present the results of detailed spectroscopic abundance analyses for 18 elements in 31 nearby stars with planets. The resulting abundances are combined with other similar studies of nearby stars with planets and compared to a sample of nearby stars without detected planets. We find some evidence for abundance differences between these two samples for Al, Si and Ti. Some of our results are in conflict with a recent study of stars with planets in the SPOCS database. We encourage continued study of the abundance patterns of stars with planets to resolve these discrepancies.

Guillermo Gonzalez; Chris Laws

2007-04-17T23:59:59.000Z

199

Remarkable Amphibian Biomass and Abundance in an Isolated Wetland: Implications for Wetland  

E-Print Network [OSTI]

DOI: 10.1111/j.1523-1739.2006.00443.x #12;2 Amphibian Biomass and Abundance Gibbons et al. Biomasa y

Todd, Brian

200

E-Print Network 3.0 - abundance monitoring hydroacoustic Sample...  

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

for: abundance monitoring hydroacoustic Page: << < 1 2 3 4 5 > >> 1 Introduction Reef fish spawning aggregations have Summary: aggregation at Little Cayman Island, Cayman...

Note: This page contains sample records for the topic "natural abundance half-life" 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 Relative Abundance of Desert Tortoises on the Nevada Test Site within Ecological Landform Units  

SciTech Connect (OSTI)

Sign-survey transects were sampled in 1996 to better determine the relative abundance of desert tortoises on the Nevada Test Site (NTS). These transects were sampled within ecological land-form units (ELUs), which are small, ecologically homogeneous units of land. Two-hundred and six ELUs were sampled by walking 332 transects totaling 889 kilometers (km) (552 miles [mi]). These ELUs covered 528 km{sup 2} (204 mi{sup 2}). Two-hundred and eighty-one sign were counted. An average of 0.32 sign was found per km walked. Seventy percent of the area sampled had a very low abundance of tortoises, 29 percent had a low abundance, and 1 percent had a moderate abundance. A revised map of the relative abundance of desert tortoise on the NTS is presented. Within the 1,330 km{sup 2} (514 mi{sup 2}) of desert tortoise habitat on the NTS, 49 percent is classified as having no tortoises or a very low abundance, 18 percent has a low or moderate abundance, 12 percent is unclassified land being used by the Yucca Mountain Site Characterization Project, and the remaining 21 percent still has an unknown abundance of desert tortoises. Based on the results of this work, the amount of tortoise habitat previously classified as having an unknown or low-moderate abundance, and on which clearance surveys and on-site monitoring was required, has been reduced by 20 percent.

Roy Woodward, Kurt R. Rautenstrauch, Derek B. Hall, and W. Kent Ostler

1998-09-01T23:59:59.000Z

202

The relative abundance of desert tortoises on the Nevada Test Site within ecological landform units  

SciTech Connect (OSTI)

Sign-survey transects were sampled in 1996 to better determine the relative abundance of desert tortoises on the Nevada Test Site (NTS). These transects were sampled within ecological land-form units (ELUs), which are small, ecologically homogeneous units of land. Two-hundred and six ELUs were sampled by walking 332 transects totaling 889 kilometers (km). These ELUs covered 528 km{sup 2}. Two-hundred and eight-one sign were counted. An average of 0.32 sign was found per km walked. Seventy percent of the area sampled had a very low abundance of tortoises, 29% had a low abundance, and 1% had a moderate abundance. A revised map of the relative abundance of desert tortoise on the NTS is presented. Within the 1,330 km{sup 2} of desert tortoise habitat on the NTS, 49% is classified as having no tortoises or a very low abundance, 18% has a low or moderate abundance, 12% is unclassified land being used by the Yucca Mountain Site Characterization Project, and the remaining 21% still has an unknown abundance of desert tortoises. Based on the results of this work, the amount of tortoise habitat previously classified as having an unknown or low-moderate abundance, and on which clearance surveys and on-site monitoring was required, has been reduced by 20%.

Woodward, R. [Bechtel National (United States); Rautenstrauch, K.R. [Science Applications International Corp. (United States); Hall, D.B.; Ostler, W.K. [Bechtel Nevada (United States)

1998-09-01T23:59:59.000Z

203

E-Print Network 3.0 - abundance chemical Sample Search Results  

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

of Nd, Sm, Zr... may have low abundances of high field strength elements, rare earth elements and Y. ... Source: Becker, Harry - Department of Geology, University of...

204

E-Print Network 3.0 - abundance cancer related Sample Search...  

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

cancer related Search Powered by Explorit Topic List Advanced Search Sample search results for: abundance cancer related Page: << < 1 2 3 4 5 > >> 1 The Therapeutic Implications of...

205

E-Print Network 3.0 - abundance ratio measurements Sample Search...  

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

O) coronal and transition region measurements of NeO ratio significantly higher... temperature independent emission line ratios - direct measurement of relative abundances use...

206

A MASS-DEPENDENT YIELD ORIGIN OF NEUTRON-CAPTURE ELEMENT ABUNDANCE DISTRIBUTIONS IN ULTRA-FAINT DWARFS  

SciTech Connect (OSTI)

One way to constrain the nature of the high-redshift progenitors of the Milky Way (MW) is to look at the low-metallicity stellar populations of the different Galactic components today. For example, high-resolution spectroscopy of very metal poor (VMP) stars demonstrates remarkable agreement between the distribution of [Ti/Fe] in the stellar populations of the MW halo and ultra-faint dwarf (UFD) galaxies. In contrast, for the neutron-capture (nc) abundance ratio distributions [(Sr, Ba)/Fe], the peak of the small UFD sample (6 stars) exhibits a significant under-abundance relative to the VMP stars in the larger MW halo sample ({approx}300 stars). We present a simple scenario that can simultaneously explain these similarities and differences by assuming: (1) that the MW VMP stars were predominately enriched by a prior generation of stars which possessed a higher total mass than the prior generation of stars that enriched the UFD VMP stars; and (2) a much stronger mass-dependent yield (MDY) for nc-elements than for the (known) MDY for Ti. Simple statistical tests demonstrate that conditions (1) and (2) are consistent with the observed abundance distributions, albeit without strong constraints on model parameters. A comparison of the broad constraints for these nc-MDY with those derived in the literature seems to rule out Ba production from low-mass supernovae (SNe) and affirms models that primarily generate yields from high-mass SNe. Our scenario can be confirmed by a relatively modest (factor of {approx}3-4) increase in the number of high-resolution spectra of VMP stars in UFDs.

Lee, Duane M.; Johnston, Kathryn V. [Department of Astronomy, Columbia University, New York City, NY 10027 (United States); Tumlinson, Jason [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Sen, Bodhisattva [Department of Statistics, Columbia University, New York City, NY 10027 (United States); Simon, Joshua D. [The Observatories of the Carnegie Institution of Washington, Pasadena, CA 91101 (United States)

2013-09-10T23:59:59.000Z

207

Dynamics in the Isotropic Phase of Nematogens Using 2D IR Vibrational Echo Measurements on Natural-Abundance 13  

E-Print Network [OSTI]

-4-pentylbiphenyl (5CB), with the CN stretch initially used as the vibrational probe. Although the CN-thiocyanobiphenyl (5SCB) was synthesized and studied as a dilute solute in 5CB. The CN stretch of 5SCB has of fast structural dynamics in the isotropic phase of 5CB. It is shown that the 5SCB probe reports

Fayer, Michael D.

208

THE CORONAL ABUNDANCES OF MID-F DWARFS  

SciTech Connect (OSTI)

A Chandra spectrum of the moderately active nearby F6 V star {pi}{sup 3} Ori is used to study the coronal properties of mid-F dwarfs. We find that {pi}{sup 3} Ori's coronal emission measure distribution is very similar to those of moderately active G and K dwarfs, with an emission measure peak near log T = 6.6 seeming to be ubiquitous for such stars. In contrast to coronal temperature, coronal abundances are known to depend on spectral type for main sequence stars. Based on this previously known relation, we expected {pi}{sup 3} Ori's corona to exhibit an extremely strong ''first ionization potential (FIP) effect'', a phenomenon first identified on the Sun where elements with low FIP are enhanced in the corona. We instead find that {pi}{sup 3} Ori's corona exhibits a FIP effect essentially identical to that of the Sun and other early G dwarfs, perhaps indicating that the increase in FIP bias toward earlier spectral types stops or at least slows for F stars. We find that {pi}{sup 3} Ori's coronal characteristics are significantly different from two previously studied mid-F stars, Procyon (F5 IV-V) and {tau} Boo (F7 V). We believe {pi}{sup 3} Ori is more representative of the coronal characteristics of mid-F dwarfs, with Procyon being different because of luminosity class, and {tau} Boo being different because of the effects of one of two close companions, one stellar ({tau} Boo B: M2 V) and one planetary.

Wood, Brian E.; Laming, J. Martin [Naval Research Laboratory, Space Science Division, Washington, DC 20375 (United States)

2013-05-10T23:59:59.000Z

209

Nature/Culture/Seawater  

E-Print Network [OSTI]

This essay considers seawater as a substance and symbol in anthropological and social theory. Seawater has occupied an ambiguous place with respect to anthropological categories of nature and culture. Seawater as nature ...

Helmreich, Stefan

210

Natural gas annual 1996  

SciTech Connect (OSTI)

This document provides information on the supply and disposition of natural gas to a wide audience. The 1996 data are presented in a sequence that follows natural gas from it`s production to it`s end use.

NONE

1997-09-01T23:59:59.000Z

211

Natural Resources Research Institute  

E-Print Network [OSTI]

/Loll ThermoWood Hybrid Poplars Peat A boost for the peat industry Value in Minnesota peat deposits Natural che

Netoff, Theoden

212

Natural gas annual 1994  

SciTech Connect (OSTI)

The Natural Gas Annual provides information on the supply and disposition of natural gas to a wide audience including industry, consumers, Federal and State agencies, and educational institutions. The 1994 data are presented in a sequence that follows natural gas (including supplemental supplies) from its production to its end use. This is followed by tables summarizing natural gas supply and disposition from 1990 to 1994 for each Census Division and each State. Annual historical data are shown at the national level.

NONE

1995-11-17T23:59:59.000Z

213

Natural gas annual 1995  

SciTech Connect (OSTI)

The Natural Gas Annual provides information on the supply and disposition of natural gas to a wide audience including industry, consumers, Federal and State agencies, and educational institutions. The 1995 data are presented in a sequence that follows natural gas (including supplemental supplies) from its production to its end use. This is followed by tables summarizing natural gas supply and disposition from 1991 to 1995 for each Census Division and each State. Annual historical data are shown at the national level.

NONE

1996-11-01T23:59:59.000Z

214

The Solar Wind Helium Abundance: Variation with Wind Speed and the Solar Cycle  

E-Print Network [OSTI]

The Solar Wind Helium Abundance: Variation with Wind Speed and the Solar Cycle Matthias R. Aellig Alamos National Lab., Los Alamos, NM 87545 Abstract We investigate the helium abundance in the solar wind of 1994 and early 2000 are analyzed. In agreement with similar work for previous solar cycles, we find

Richardson, John

215

Grey seal distribution and abundance in North Wales, 2002-2003  

E-Print Network [OSTI]

i Grey seal distribution and abundance in North Wales, 2002-2003 Westcott, S.M. & Stringell, T.B. Stringell Title: "Grey seal distribution and abundance in North Wales, 2002-2003" Authors: Westcott, S Library x1 C. Duck, SMRU x1 Joe Breen EHS x1 PML, Library, Plymouth x1 S. Westcott x5 M. Baines x1 S

Bearhop, Stuart

216

Fully corrected estimates of common minke whale abundance in West Greenland in 2007  

E-Print Network [OSTI]

Fully corrected estimates of common minke whale abundance in West Greenland in 2007 M.P. HEIDE West Greenland in August and September 2007. A total of 8,670km of survey effort covered 11 strata SURVEY; SATELLITE TAGGING; WEST GREENLAND minke whales to fully corrected total estimates of abundance

Laidre, Kristin L.

217

Identification in Pea Seed Mitochondria of a Late-Embryogenesis Abundant Protein Able to  

E-Print Network [OSTI]

lack of well-ordered tertiary structure of LEA proteins preventing their use as catalysts, severalIdentification in Pea Seed Mitochondria of a Late-Embryogenesis Abundant Protein Able to Protect, 38054 Grenoble cedex 9, France (D.G.) Late-embryogenesis abundant (LEA) proteins are hydrophilic

Paris-Sud XI, Université de

218

EARTH ABUNDANT MATERIALS FOR HIGH EFFICIENCY HETEROJUNCTION THIN FILM SOLAR CELLS  

E-Print Network [OSTI]

EARTH ABUNDANT MATERIALS FOR HIGH EFFICIENCY HETEROJUNCTION THIN FILM SOLAR CELLS Yun Seog Lee 1; * Corresponding author: buonassisi@mit.edu; ABSTRACT We investigate earth abundant materials for thin- film solar cuprous oxide (Cu2O) as a prototype candidate for investigation as an absorber layer in thin film solar

Ceder, Gerbrand

219

Accepted Manuscript Abundances of presolar silicon carbide grains in primitive meteorites deter-  

E-Print Network [OSTI]

Accepted Manuscript Abundances of presolar silicon carbide grains in primitive meteorites deter.R., Alexander, C.M., Orthous-Daunay, o-R., Franchi, I.A., Hoppe, P., Abundances of presolar silicon carbide of presolar silicon carbide grains in primitive meteorites determined by NanoSIMS Jemma Davidsona,1,* , Henner

Nittler, Larry R.

220

A unified model of species immigration, extinction and abundance on islands  

E-Print Network [OSTI]

ORIGINAL ARTICLE A unified model of species immigration, extinction and abundance on islands James and extinction rates as functions of species richness at dynamic equilibrium. In contrast, the approach results highlight the importance of species abundances as indi- cators of immigration and extinction rates

Harmon, Luke

Note: This page contains sample records for the topic "natural abundance half-life" 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

Seasonal measurements of acetone and methanol: Abundances and implications for atmospheric budgets  

E-Print Network [OSTI]

, 2002] and photochemical produc- tion from hydrocarbon precursors. Methanol is often the most abundantSeasonal measurements of acetone and methanol: Abundances and implications for atmospheric budgets December 2005; published 21 February 2006. [1] Acetone and methanol have been measured hourly at a rural

Cohen, Ronald C.

222

Techniques and Technology Article Aerial Surveys for Estimating Wild Turkey Abundance in  

E-Print Network [OSTI]

Techniques and Technology Article Aerial Surveys for Estimating Wild Turkey Abundance in the Texas Aerial surveys have been used to estimate abundance of several wild bird species including wild turkeys (Meleagris gallopavo). We used inflatable turkey decoys at 3 study sites in the Texas Rolling Plains

Butler, Matthew J.

223

OCCUPANCY DISTRIBUTIONS ARISING IN SAMPLING FROM GIBBS-POISSON ABUNDANCE MODELS  

E-Print Network [OSTI]

together with a sampling model. We start with a discrete model of iid stochastic species abundances, each, which is a measure of richness or diversity of species. We rederive the sam- pling formulae1 , SERVET MART´INEZ2 (iid) stochastic species abundances d = 1, ..., n , based on Gibbs

224

The Oxygen Abundance of Nearby Galaxies from Sloan Digital Sky Survey Spectra  

E-Print Network [OSTI]

We have derived the oxygen abundance for a sample of nearby galaxies in the Data Release 5 of the Sloan Digital Sky Survey (SDSS) which possess at least two independent spectra of one or several HII regions with a detected [OIII]4363 auroral line. Since, for nearby galaxies, the [OII]3727 nebular line is out of the observed wavelength range, we propose a method to derive (O/H)_ff abundances using the classic Te method coupled with the ff relation. (O/H)_7325 abundances have also been determined, based on the [OII]7320,7330 line intensities, and using a small modification of the standard Te method. The (O/H)_ff and (O/H)_7325 abundances have been derived with both the one- and two-dimensional t_2 - t_3 relations. It was found that the (O/H)_ff abundances derived with the parametric two-dimensional t_2 - t_3 relation are most reliable. Oxygen abundances have been determined in 29 nearby galaxies, based on 84 individual abundance determinations in HII regions. Because of our selection methods, the metallicity of our galaxies lies in the narrow range 8.2 oxygen abundances in the disk of the spiral galaxy NGC 4490 is determined for the first time.

L. S. Pilyugin; T. X. Thuan

2007-07-19T23:59:59.000Z

225

EIA - Natural Gas Pipeline Network - Largest Natural Gas Pipeline...  

U.S. Energy Information Administration (EIA) Indexed Site

Interstate Pipelines Table About U.S. Natural Gas Pipelines - Transporting Natural Gas based on data through 20072008 with selected updates Thirty Largest U.S. Interstate Natural...

226

On the maximum value of the cosmic abundance of oxygen and the oxygen yield  

E-Print Network [OSTI]

We search for the maximum oxygen abundance in spiral galaxies. Because this maximum value is expected to occur in the centers of the most luminous galaxies, we have constructed the luminosity - central metallicity diagram for spiral galaxies, based on a large compilation of existing data on oxygen abundances of HII regions in spiral galaxies. We found that this diagram shows a plateau at high luminosities (-22.3 oxygen abundance 12+log(O/H) ~ 8.87. This provides strong evidence that the oxygen abundance in the centers of the most luminous metal-rich galaxies reaches the maximum attainable value of oxygen abundance. Since some fraction of the oxygen (about 0.08 dex) is expected to be locked into dust grains, the maximum value of the true gas+dust oxygen abundance in spiral galaxies is 12+log(O/H) ~ 8.95. This value is a factor of ~ 2 higher than the recently estimated solar value. Based on the derived maximum oxygen abundance in galaxies, we found the oxygen yield to be about 0.0035, depending on the fraction of oxygen incorporated into dust grains.

L. S. Pilyugin; T. X. Thuan; J. M. Vilchez

2007-01-11T23:59:59.000Z

227

The Role of Concrete Marine Structures in the Recovery of Energy and Natural Resources from the  

E-Print Network [OSTI]

The Role of Concrete Marine Structures in the Recovery of Energy and Natural Resources from Concrete materials are derived from some of the most abundant and economically available sources on this planet. Recent advancements in the development of concrete technology related to the durability, strength

Frandsen, Jannette B.

228

Non-LTE metal abundances in V652 Her and HD144941  

E-Print Network [OSTI]

Two evolutionary scenarios are proposed for the formation of extreme helium stars: a post-AGB star suffering from a late thermal pulse, or the merger of two white dwarfs. An identification of the evolutionary channel for individual objects has to rely on surface abundances. We present preliminary results from a non-LTE analysis of CNO, Mg and S for two unique objects, V652 Her and HD144941. Non-LTE abundance corrections for these elements range from negligible values to ~0.7 dex. Non-LTE effects typically lead to systematic shifts in the abundances relative to LTE and reduce the uncertainties.

N. Przybilla; M. F. Nieva; U. Heber; C. S. Jeffery

2005-12-06T23:59:59.000Z

229

Liquefied Natural Gas (Iowa)  

Broader source: Energy.gov [DOE]

This document adopts the standards promulgated by the National Fire Protection Association as rules for the transportation, storage, handling, and use of liquefied natural gas. The NFPA standards...

230

Natural gas dehydration apparatus  

DOE Patents [OSTI]

A process and corresponding apparatus for dehydrating gas, especially natural gas. The process includes an absorption step and a membrane pervaporation step to regenerate the liquid sorbent.

Wijmans, Johannes G; Ng, Alvin; Mairal, Anurag P

2006-11-07T23:59:59.000Z

231

Natural Resources Specialist  

Broader source: Energy.gov [DOE]

(See Frequently Asked Questions for more information). Where would I be working ? Western Area Power Administration, Corporate Services Office, Office of the Chief Operating Officer, Natural...

232

Natural Heritage Program (Missouri)  

Broader source: Energy.gov [DOE]

Natural Heritage Reviews are conducted by the Missouri Department of Conservation on request in order to assess proposed project sites and adjacent lands. Reviews determine whether potential...

233

Natural Cooling Retrofit  

E-Print Network [OSTI]

of the most important design considerations for any method of Natural Cool ing is the chil led water temperature range selected for use during Natural Cool ing. Figure VI shows that for a hypo thetical Chicago plant, the hours of operation for a Natural..." system on the Natural Cool ing cycle. As the pressures and flow rates of the condenser and chil led water systems are seldom the same, the designer must pay careful attention to the cross over system design to ensure harmonious operations on both...

Fenster, L. C.; Grantier, A. J.

1981-01-01T23:59:59.000Z

234

,"Colorado Natural Gas Prices"  

U.S. Energy Information Administration (EIA) Indexed Site

Name","Description"," Of Series","Frequency","Latest Data for" ,"Data 1","Colorado Natural Gas Prices",8,"Monthly","112014","1151989" ,"Release Date:","1302015"...

235

Natural gas annual 1997  

SciTech Connect (OSTI)

The Natural Gas Annual provides information on the supply and disposition of natural gas to a wide audience including industry, consumers, Federal and State agencies, and educational institutions. The 1997 data are presented in a sequence that follows natural gas (including supplemental supplies) from its production to its end use. This is followed by tables summarizing natural gas supply and disposition from 1993 to 1997 for each Census Division and each State. Annual historical data are shown at the national level. 27 figs., 109 tabs.

NONE

1998-10-01T23:59:59.000Z

236

Warner College of Natural Resources Warner College of Natural  

E-Print Network [OSTI]

, and scientific investigation of renewable and nonrenewable natural resources. Programs include the study of everyWarner College of Natural Resources Warner College of Natural Resources Office in Natural Resources, and Conservation Biology Forestry Geology Natural Resource Recreation and Tourism Natural Resources Management

Collett Jr., Jeffrey L.

237

The melting and abundance of open charm hadrons  

E-Print Network [OSTI]

Ratios of cumulants of conserved net charge fluctuations are sensitive to the degrees of freedom that are carriers of the corresponding quantum numbers in different phases of strong interaction matter. Using lattice QCD with 2+1 dynamical flavors and quenched charm quarks we calculate second and fourth order cumulants of net charm fluctuations and their correlations with other conserved charges such as net baryon number, electric charge and strangeness. Analyzing appropriate ratios of these cumulants we probe the nature of charmed degrees of freedom in the vicinity of the QCD chiral crossover region. We show that for temperatures above the chiral crossover transition temperature, charmed degrees of freedom can no longer be described by an uncorrelated gas of hadrons. This suggests that the dissociation of open charm hadrons and the emergence of deconfined charm states sets in just near the chiral crossover transition. Till the crossover region we compare these lattice QCD results with two hadron resonance gas models --including only the experimentally established charmed resonances and also including additional states predicted by quark model and lattice QCD calculations. This comparison provides evidence for so far unobserved charmed hadrons that contribute to the thermodynamics in the crossover region.

A. Bazavov; H. -T. Ding; P. Hegde; O. Kaczmarek; F. Karsch; E. Laermann; Y. Maezawa; Swagato Mukherjee; H. Ohno; P. Petreczky; C. Schmidt; S. Sharma; W. Soeldner; M. Wagner

2014-09-01T23:59:59.000Z

238

Influence of hydrological seasonality on sandbank benthos: algal biomass and shrimp abundance in a large neotropical river  

E-Print Network [OSTI]

with seven species inhabiting the sandbanks of the Cinaruco. I also observed clear patterns of temporal and spatial variation in shrimp abundance on the Cinaruco sandbanks. Abundance of shrimp on the sandbanks presented remarkable diel variation, showing...

Montoya Ceballos, Jose Vicente

2009-05-15T23:59:59.000Z

239

Environmental factors affecting planktonic foraminifera abundance and distribution in the Northeast Gulf of Mexico  

E-Print Network [OSTI]

shift in the species abundances and depths occurred between eddies. Species occurred where physical factors were compatible with conditions and feeding opportunities they were adapted to. Three species pink and white Globigerinoides ruber...

Ravula, Sharath Reddy

2005-08-29T23:59:59.000Z

240

E-Print Network 3.0 - abundance solid-state 33s Sample Search...  

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

by Explorit Topic List Advanced Search Sample search results for: abundance solid-state 33s Page: << < 1 2 3 4 5 > >> 1 Methodological developments of solid-state NMR and...

Note: This page contains sample records for the topic "natural abundance half-life" 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

Earth abundant materials for high efficiency heterojunction thin film solar cells  

E-Print Network [OSTI]

We investigate earth abundant materials for thin-film solar cells that can meet tens of terawatts level deployment potential. Candidate materials are identified by combinatorial search, large-scale electronic structure ...

Buonassisi, Tonio

242

E-Print Network 3.0 - astrophysically abundant atoms Sample Search...  

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

D.E., Ibbetson, P... the Determination of the Solar Iron Abundance Using Fe I Lines" Astronomy and Astrophysics 296, pg 217-232 (1995... and a Redetermination of the Solar Cobalt...

243

Abundances of presolar silicon carbide grains in primitive meteorites determined by NanoSIMS  

E-Print Network [OSTI]

Abundances of presolar silicon carbide grains in primitive meteorites determined by NanoSIMS Jemma carbide (SiC) grains estimated from their noble gas components show significant variations in even

Nittler, Larry R.

244

Reef Habitats in the Middle Atlantic Bight: Abundance, Distribution, Associated Biological  

E-Print Network [OSTI]

abundance of fishery resources are in- and Biggs, 1988; Poppe et al., 1994). fluenced by physical and other can Stumf and Biggs, 1988; Poppe et al., lead to a better understanding of how 1994; NOAA National

245

Abundance analysis of SB2 binary stars with HgMn primaries  

E-Print Network [OSTI]

We present a short review of the abundances in the atmospheres of SB2 systems with Mercury-Manganese (HgMn) primaries. Up to now a careful study has been made for both components of 8 out of 17 known SB2 binaries with orbital periods shorter than 100 days and mass ratio ranging from 1.08 to 2.2. For all eight systems we observe a lower Mn abundance in the secondary's atmospheres than in the primary's. Significant difference in the abundances is also found for some peculiar elements such as Ga, Xe, Pt. All secondary stars with effective temperatures less than 10000 K show abundance characteristics typical of the metallic-line stars.

T. Ryabchikova

1998-05-06T23:59:59.000Z

246

E-Print Network 3.0 - abundant biopolymers cellulose Sample Search...  

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

Topic List Advanced Search Sample search results for: abundant biopolymers cellulose Page: << < 1 2 3 4 5 > >> 1 Cellulose 8: 91-97,200. (i) 2001 Kluwer AcademIc Publishers....

247

E-Print Network 3.0 - abundance discrepancy problem Sample Search...  

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

and mercurymanganese type lateB stars from Summary: Abundance analysis of normal and mercury-manganese type late-B stars from optical spectra Caroline... 1997 1 12; Dedication...

248

Line formation in solar granulation: III. The photospheric Si and meteoritic Fe abundances  

E-Print Network [OSTI]

Using realistic hydrodynamical simulations of the solar surface convection as 3D, time-dependent, inhomogeneous model atmospheres, the solar photospheric Si abundance has been determined to be log Si = 7.51 +- 0.04. This constitutes a difference of 0.04 dex compared with previous estimates based on the 1D Holweger-M\\"uller (1974) model, of which half is attributable to the adopted model atmosphere and the remaining part to the improved quantum mechanical broadening treatment. As a consequence, all meteoritic abundances should be adjusted downwards by the same amount. In particular the meteoritic Fe abundance will be log Fe = 7.46 +- 0.01, in good agreement with the recently determined photospheric Fe abundance (Asplund et al. 2000b). The existing uncertainties unfortunately prevent an observational confirmation of the postulated effects of elemental migration of metals in the Sun.

M. Asplund

2000-05-15T23:59:59.000Z

249

Influences of vegetation characteristics and invertebrate abundance of Rio Grande wild turkey populations, Edwards Plateau, Texas  

E-Print Network [OSTI]

Since 1970, Rio Grande wild turkey (Meleagris gallapavo intermedia) numbers in the southern region of the Edwards Plateau of Texas have been declining. Nest-site characteristics and invertebrate abundance were hypothesized as limiting wild turkey...

Randel, Charles Jack

2005-02-17T23:59:59.000Z

250

Spatial pattern and temporal dynamics of northern bobwhite abundance and agricultural landuse, and potential casual factors  

E-Print Network [OSTI]

of increased abundance occurred in southern Michigan, Indiana, Ohio, northern Kentucky, Illinois, Iowa and Missouri, and eastern Kansas, and central Oklahoma (Fig. 2.3A). Abundance decreased between the 10 year period surrounding 1920 and 1930 for most.... 2.3C). In fact, there were no regions of the United States of characterized by marked, broad scale in NBW numbers. However, some isolated increases occurred in central Nebraska, Kentucky, Alabama, and small parts of western Oklahoma and Texas...

Okay, Atiye Zeynep

2006-04-12T23:59:59.000Z

251

Abundances, Stellar Parameters, and Spectra From the SDSS-III/APOGEE Survey  

E-Print Network [OSTI]

The SDSS-III/APOGEE survey operated from 2011-2014 using the APOGEE spectrograph, which collects high-resolution (R~22,500), near-IR (1.51-1.70 microns) spectra with a multiplexing (300 fiber-fed objects) capability. We describe the survey data products that are publicly available, which include catalogs with radial velocity, stellar parameters, and 15 elemental abundances for over 150,000 stars, as well as the more than 500,000 spectra from which these quantities are derived. Calibration relations for the stellar parameters (Teff, log g, [M/H], [alpha/M]) and abundances (C, N, O, Na, Mg, Al, Si, S, K, Ca, Ti, V, Mn, Fe, Ni) are presented and discussed. The internal scatter of the abundances within clusters indicates that abundance precision is generally between 0.05 and 0.09 dex across a broad temperature range; within more limited ranges and at high S/N, it is smaller for some elemental abundances. We assess the accuracy of the abundances using comparison of mean cluster metallicities with literature values...

Holtzman, Jon A; Johnson, Jennifer A; Prieto, Carlos Allende; Anders, Friedrich; Andrews, Brett; Beers, Timothy C; Bizyaev, Dmitry; Blanton, Michael R; Bovy, Jo; Carrera, Ricardo; Cunha, Katia; Eisenstein, Daniel J; Feuillet, Diane; Frinchaboy, Peter M; Galbraith-Frew, Jessica; Perez, Ana E Garcia; Hernandez, D Anibal Garcia; Hasselquist, Sten; Hayden, Michael R; Hearty, Fred R; Ivans, Inese; Majewski, Steven R; Martell, Sarah; Meszaros, Szabolcs; Muna, Demitri; Nidever, David L; Nguyen, Duy Cuong; O'Connell, Robert W; Pan, Kaike; Pinsonneault, Marc; Robin, Annie C; Schiavon, Ricardo P; Shane, Neville; Sobeck, Jennifer; Smith, Verne V; Troup, Nicholas; Weinberg, David H; Wilson, John C; Wood-Vasey, W M; Zamora, Olga; Zasowski, Gail

2015-01-01T23:59:59.000Z

252

Chemical Abundances in AGN Environment: X-Ray/UV Campaign on the MRK 279 Outflow  

E-Print Network [OSTI]

We present the first reliable determination of chemical abundances in an AGN outflow. The abundances are extracted from the deep and simultaneous FUSE and HST/STIS observations of Mrk 279. This data set is exceptional for its high signal-to-noise, unblended doublet troughs and little Galactic absorption contamination. These attributes allow us to solve for the velocity-dependent covering fraction, and therefore obtain reliable column densities for many ionic species. For the first time we have enough such column densities to simultaneously determine the ionization equilibrium and abundances in the flow. Our analysis uses the full spectral information embedded in these high-resolution data. Slicing a given trough into many independent outflow elements yields the extra constraints needed for a physically meaningful abundances determination. We find that relative to solar the abundances in the Mrk 279 outflow are (linear scaling): carbon 2.2+/-0.7, nitrogen 3.5+/-1.1 and oxygen 1.6+/-0.8. Our UV-based photoionization and abundances results are in good agreement with the independent analysis of the simultaneous Mrk 279 X-ray spectra. This is the best agreement between the UV and X-ray analyses of the same outflow to date.

Nahum Arav; Jack R. Gabel; Kirk T. Korista; Jelle S. Kaastra; Gerard A. Kriss; Ehud Behar; Elisa Costantini; C. Martin Gaskell; Ari Laor; Nalaka Kodituwakku; Daniel Proga; Masao Sako; Jennifer E. Scott; Katrien C. Steenbrugge

2006-11-29T23:59:59.000Z

253

The abundance of presolar grains in comet 81P/WILD 2  

SciTech Connect (OSTI)

We carried out hypervelocity impact experiments in order to test the possibility that presolar grains are preferentially destroyed during impact of the comet 81P/Wild 2 samples into the Stardust Al foil collectors. Powdered samples of the ungrouped carbonaceous chondrite Acfer 094 were shot at 6 km s{sup -1} into Stardust flight spare Al foil. Craters from the Acfer 094 test shots, as well as ones from the actual Stardust cometary foils, were analyzed by NanoSIMS ion imaging to search for presolar grains. We found two O-rich presolar grains and two presolar SiC grains in the Acfer 94 test shots, with measured abundances in the foils of 4 and 5 ppm, respectively, significantly lower than the amount of presolar grains actually present in this meteorite. Based on known abundances of these phases in Acfer 094, we estimate a loss of over 90% of the O-rich presolar grains; the fraction of SiC lost is lower, reflecting its higher resistance to destruction. In the Stardust cometary foils, we identified four O-rich presolar grains in 5000 {mu}m{sup 2} of crater residue. Including a presolar silicate grain found by Leitner et al., the overall measured abundance of O-rich presolar grains in Wild 2 is {approx}35 ppm. No presolar SiC has been found in the foil searches, although one was identified in the aerogel samples. Based on the known abundances of presolar silicates and oxides in Acfer 094, we can calculate the pre-impact abundances of these grains in the Stardust samples. Our calculations indicate initial abundances of 600-830 ppm for O-rich presolar grains. Assuming a typical diameter of {approx}300 nm for SiC suggests a presolar SiC abundance of {approx}45 ppm. Analyses of the Stardust samples indicated early on that recognizable presolar components were not particularly abundant, an observation that was contrary to expectations that the cometary material would, like interplanetary dust particles, be dominated by primitive materials from the early solar system (including abundant presolar grains), which had remained essentially unaltered over solar system history in the cold environment of the Kuiper Belt. Our work shows that comet Wild 2, in fact, does contain more presolar grains than measurements on the Stardust samples suggest, with abundances similar to those observed in primitive IDPs.

Floss, Christine; Stadermann, Frank J.; Ong, W. J. [Laboratory for Space Sciences, Physics Department, Washington University, 1 Brookings Drive, St. Louis, MO 63130 (United States)] [Laboratory for Space Sciences, Physics Department, Washington University, 1 Brookings Drive, St. Louis, MO 63130 (United States); Kearsley, Anton T. [Impacts and Astromaterials Research Centre, Science Facilities, Natural History Museum, London SW7 5BD (United Kingdom)] [Impacts and Astromaterials Research Centre, Science Facilities, Natural History Museum, London SW7 5BD (United Kingdom); Burchell, Mark J., E-mail: floss@wustl.edu [Centre for Astrophysics and Planetary Sciences, School of Physical Sciences, University of Kent, Canterbury, Kent CT2 7NH (United Kingdom)

2013-02-15T23:59:59.000Z

254

New Rare Earth Element Abundance Distributions for the Sun and Five r-Process-Rich Very Metal-Poor Stars  

E-Print Network [OSTI]

We have derived new abundances of the rare-earth elements Pr, Dy, Tm, Yb, and Lu for the solar photosphere and for five very metal-poor, neutron-capture r-process-rich giant stars. The photospheric values for all five elements are in good agreement with meteoritic abundances. For the low metallicity sample, these abundances have been combined with new Ce abundances from a companion paper, and reconsideration of a few other elements in individual stars, to produce internally-consistent Ba, rare-earth, and Hf (56element distributions. These have been used in a critical comparison between stellar and solar r-process abundance mixes.

Sneden, Christopher; Cowan, John J; Ivans, Inese I; Hartog, Elizabeth A Den

2009-01-01T23:59:59.000Z

255

Abundance and ecological implications of microplastic debris in the North Pacific Subtropical Gyre  

E-Print Network [OSTI]

of the central North Pacific ocean. Nature 241:271–271. doi:waste distributions in Pacific Ocean. Nature 247:30–32. doi:of the central North Pacific ocean. Nature 241:271–271. doi:

Goldstein, Miriam Chanita

2012-01-01T23:59:59.000Z

256

47 Natural Gas Market Trends NATURAL GAS MARKET TRENDS  

E-Print Network [OSTI]

47 Natural Gas Market Trends Chapter 5 NATURAL GAS MARKET TRENDS INTRODUCTION Natural gas discusses current natural gas market conditions in California and the rest of North America, followed on the outlook for demand, supply, and price of natural gas for the forecasted 20-year horizon. It also addresses

257

Growth, Development and Natural Resources: New Evidence Using a Heterogeneous Panel Analysis  

E-Print Network [OSTI]

rather than abundance. The latter should be introduced in the growth regressions as the stock or the ?ow of natural resources. Moreover, a cross sectional growth regression augmented with this regressor clearly su¤ers from endogeneity and omitted variable... evidence of the e¤ects of resource abundance on growth may be questioned. Firstly, the literature relies primarily on a cross-sectional approach to test the resource curse hypothesis, and as such does not take into account the time dimension of the data...

Cavalcanti, T V V; Mohaddes, K; Raissi, M

258

Nature Preserves (North Dakota)  

Broader source: Energy.gov [DOE]

The Parks and Recreation Department is responsible for managing and acquiring designated nature areas in the state of North Dakota. New construction and development is severely restricted on these...

259

NATURAL MARINE HYDROCARBON SEEPAGE  

E-Print Network [OSTI]

affects ocean chemistry (Dando and Hovland, 1992) and provides a natural source of petroleum pollution the water column above submarine vents, plumes of hydrocarbon gas bubbles act as acoustic scattering targets

Luyendyk, Bruce

260

Natural Resource Specialist  

Broader source: Energy.gov [DOE]

A successful candidate in this position will serve as a Natural Resource Specialist responsible for participating in the development and implementation of short-term and long-term regional (multi...

Note: This page contains sample records for the topic "natural abundance half-life" 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

Natural Gas Regulations (Kentucky)  

Broader source: Energy.gov [DOE]

Kentucky Administrative Regulation title 805 promulgates the rules and regulations pertaining to natural gas production in Kentucky. In addition to KAR title 405, chapter 30, which pertains to any...

262

Natural gas monthly  

SciTech Connect (OSTI)

This document highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Data presented include volume and price, production, consumption, underground storage, and interstate pipeline activities.

NONE

1996-05-01T23:59:59.000Z

263

EIA - Natural Gas Pipeline Network - Natural Gas Supply Basins...  

Gasoline and Diesel Fuel Update (EIA)

with selected updates U.S. Natural Gas Supply Basins Relative to Major Natural Gas Pipeline Transportation Corridors, 2008 U.S. Natural Gas Transporation Corridors out of Major...

264

Oxygen abundances in G- and F-type stars from HARPS  

E-Print Network [OSTI]

We present a detailed and uniform study of oxygen abundance from two different oxygen lines at 6158$\\AA$ and 6300$\\AA$ in a large sample of solar-type stars. The results are used to check the behaviour of these spectral lines as oxygen abundance indicators and to study the evolution of oxygen in thick and thin disk populations of the Galaxy. Equivalent width measurements were carried out for the [OI]~6158$\\AA$ and OI~6300$\\AA$ lines. LTE abundances were obtained from these two lines in 610 and 535 stars, respectively. We were able to measure oxygen abundance from both indicators in 447 stars, enabling us, for the first time, to compare them in a uniform way. Careful error analysis has been performed. We found that oxygen abundances derived from the 6158$\\AA$ and 6300$\\AA$ lines agree to within 0.1dex in 58\\% of the stars in our sample, and this result improves for higher signal-to-noise values. We confirm an oxygen enhancement in stars of the thick disk, as has also been seen for other $\\alpha$-elements. The ...

de Lis, S Bertran; Adibekyan, V Zh; Santos, N C; Sousa, S G

2015-01-01T23:59:59.000Z

265

A Low Solar Oxygen Abundance from the First Overtone OH Lines  

E-Print Network [OSTI]

An extremely high-resolution (> 10^5) high-S/N (> 10^3) solar spectrum has been used to measure 15 very weak first overtone (Delta v = 2) infrared OH lines, resulting in a low solar abundance of A(O) ~ 8.6 when MARCS, 3D, and spatially and temporally averaged 3D model atmospheres are used. A higher abundance is obtained with Kurucz (A(O) ~ 8.7) and Holweger & Muller (A(O) ~ 8.8) model atmospheres. The low solar oxygen abundance obtained in this work is in good agreement with a recent 3D analysis of [OI], OI, OH fundamental (Delta v = 1) vibration-rotation and OH pure rotation lines (Asplund et al. 2004). The present result brings further support for a low solar metallicity, and although using a low solar abundance with OPAL opacities ruins the agreement between the calculated and the helioseismic measurement of the depth of the solar convection zone, recent results from the OP project show that the opacities near the base of the solar convection zone are larger than previously thought, bringing further confidence for a low solar oxygen abundance.

Jorge Melendez

2004-07-16T23:59:59.000Z

266

The chemical composition of red giants in 47 Tucanae I: Fundamental parameters and chemical abundance patterns  

E-Print Network [OSTI]

Context: The study of chemical abundance patterns in globular clusters is of key importance to constrain the different candidates for intra-cluster pollution of light elements. Aims: We aim at deriving accurate abundances for a large range of elements in the globular cluster 47 Tucanae (NGC 104) to add new constraints to the pollution scenarios for this particular cluster, expanding the range of previously derived element abundances. Methods: Using tailored 1D LTE atmospheric models together with a combination of equivalent width measurements, LTE, and NLTE synthesis we derive stellar parameters and element abundances from high-resolution, high signal-to-noise spectra of 13 red giant stars near the tip of the RGB. Results: We derive abundances of a total 27 elements (O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Mo, Ru, Ba, La, Ce, Pr, Nd, Eu, Dy). Departures from LTE were taken into account for Na, Al and Ba. We find a mean [Fe/H] = $-0.78\\pm0.07$ and $[\\alpha/{\\rm Fe}]=0.34\\pm0.03$ in...

Thygesen, A O; Andrievsky, S; Korotin, S; Yong, D; Zaggia, S; Ludwig, H -G; Collet, R; Asplund, M; D'Antona, F; Meléndez, J; D'Ercole, A

2014-01-01T23:59:59.000Z

267

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

268

Welcome FUPWG- Natural Gas Overview  

Broader source: Energy.gov [DOE]

Presentation—given at the Federal Utility Partnership Working Group (FUPWG) Fall 2008 meeting—provides an overview of natural gas, including emissions, compressed natural gas (CNG) vehicles, and landfill gas supplement for natural gas system.

269

CHAOS I: Direct Chemical Abundances for HII Regions in NGC 628  

E-Print Network [OSTI]

The CHemical Abundances of Spirals (CHAOS) project leverages the combined power of the Large Binocular Telescope (LBT) with the broad spectral range and sensitivity of the Multi Object Double Spectrograph (MODS) to measure "direct" abundances in large samples of HII regions in spiral galaxies. We present LBT MODS observations of 62 HII regions in the nearby NGC628. We measure one or more auroral lines ([OIII] 4363, [NII] 5755, [SIII] 6312, or [OII] 7320,7330) in a large number of HII regions (40). Comparing derived temperatures from multiple auroral line measurements, we find: a strong correlation between temperatures based on [SIII] and [NII]; and large discrepancies for some temperatures based on [OII] and [OIII]. These trends are consistent with other observations in the literature, yet, given the widespread use and acceptance of [OIII] as a temperature determinant, the magnitude of the T[OIII] discrepancies still came as a surprise. Based on these results, we conduct a uniform abundance analysis using the...

Berg, Danielle A; Skillman, Evan D; Pogge, Richard W; Moustakas, John; Groh-Johnson, Mara

2015-01-01T23:59:59.000Z

270

ATMOSPHERIC COMPOSITION OF WEAK G BAND STARS: CNO AND Li ABUNDANCES  

SciTech Connect (OSTI)

We determined the chemical composition of a large sample of weak G band stars-a rare class of G and K giants of intermediate mass with unusual abundances of C, N, and Li. We have observed 24 weak G band stars with the 2.7 m Harlan J. Smith Telescope at the McDonald Observatory and derived spectroscopic abundances for C, N, O, and Li, as well as for selected elements from Na-Eu. The results show that the atmospheres of weak G band stars are highly contaminated with CN-cycle products. The C underabundance is about a factor of 20 larger than for normal giants and the {sup 12}C/{sup 13}C ratio approaches the CN-cycle equilibrium value. In addition to the striking CN-cycle signature the strong N overabundance may indicate the presence of partially ON-cycled material in the atmospheres of the weak G band stars. The exact mechanism responsible for the transport of the elements to the surface has yet to be identified but could be induced by rapid rotation of the main sequence progenitors of the stars. The unusually high Li abundances in some of the stars are an indicator for Li production by the Cameron-Fowler mechanism. A quantitative prediction of a weak G band star's Li abundance is complicated by the strong temperature sensitivity of the mechanism and its participants. In addition to the unusual abundances of CN-cycle elements and Li, we find an overabundance of Na that is in accordance with the NeNa chain running in parallel with the CN cycle. Apart from these peculiarities, the element abundances in a weak G band star's atmosphere are consistent with those of normal giants.

Adamczak, Jens; Lambert, David L., E-mail: adamczak@astro.as.utexas.edu [McDonald Observatory, University of Texas, Austin, TX 78712 (United States)

2013-03-10T23:59:59.000Z

271

Historical Natural Gas Annual 1999  

U.S. Energy Information Administration (EIA) Indexed Site

1999 The Historical Natural Gas Annual contains historical information on supply and disposition of natural gas at the national, regional, and State level as well as prices at...

272

Natural Gas | Department of Energy  

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

Fossil Natural Gas Natural Gas September 15, 2014 NETL Releases Hydraulic Fracturing Study The National Energy Technology Laboratory has released a technical report on the...

273

Seasonal abundance and diversity of ichthyoneuston in the northwestern Gulf of Mexico  

E-Print Network [OSTI]

SEASONAL ABUNDANCE AND DIVERSITY OF ICHTHYONEUSTON IN THE NORTHWESTERN GULF OF MEXICO A Thesis by MARY ANN DAHER Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER... Committee: Dr. John D. McEachran Larvae of forty-six species of fishes were collected from neuston samples in the northwestern Gulf of Mexico during 1976 and January 1977. 1'h h d p ' * M~l~ht, H~l E . ~N' ' dl dB Ichthyoneuston was more abundant...

Daher, Mary Ann

1979-01-01T23:59:59.000Z

274

EIA - Natural Gas Publications  

Gasoline and Diesel Fuel Update (EIA)

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 Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 633 622 56623Primary MetalsOriginCapacityNatural Gas

275

Go Abroad in Natural ResourcesNatural Resources  

E-Print Network [OSTI]

Go Abroad in Natural ResourcesNatural Resources Program Contact: Connie Patterson Program.edu/ international The Natural Resources degree is ideally suited for students who wish to study abroad! The sustainable management of natural resources is a fundamental issue, both locally and globally. Scientists

Escher, Christine

276

Water voles, mink & rabbits So far, the Scottish Highlands have provided water voles with a natural refuge from  

E-Print Network [OSTI]

Water voles, mink & rabbits So far, the Scottish Highlands have provided water voles with a natural, an abundance of rabbits may open the way for an untimely invasion of mink. WATER VOLES, MINK AND RABBITS W hen re-introducing extinct species is on the conservation agenda, the prospect of losing the water vole

Lambin, Xavier

277

STEWARDSHIP MAINTAINING NATURAL RICHES  

E-Print Network [OSTI]

;Outstanding Results 5 Energy Conservation: Saved 240 Million KWH over last fifteen years. Green BuildingLAND STEWARDSHIP MAINTAINING NATURAL RICHES TRANSPORTATION GOING THE EXTRA MILE GREEN BUILDING SHOWCASING INNOVATION WATER CONSERVING PRESCIOUS RESOURCES ENERGY MOVING TO A BRIGHTER FUTURE WASTE REDUCING

Ford, James

278

Natural Gas Purchasing Options  

E-Print Network [OSTI]

As a result of economic and regulatory changes, the natural gas marketplace now offers multiple options for purchasers. The purpose of this panel is to discuss short-term purchasing options and how to take advantage of these options both to lower...

Watkins, G.

279

Korarchaeota Diversity, Biogeography, and Abundance in Yellowstone and Great Basin Hot Springs and  

E-Print Network [OSTI]

, Christian A. Ross1 , Everett L. Shock2,3 , Amanda J. Williams1 , Hilairy E. Hartnett2,3 , Austin I. McDonald1¤ , Jeff R. Havig2 , Brian P. Hedlund1 * 1 School of Life Sciences, University of Nevada, Las Vegas, Williams AJ, et al. (2012) Korarchaeota Diversity, Biogeography, and Abundance in Yellowstone and Great

Ahmad, Sajjad

280

Simulations of water isotope abundances in the upper troposphere and lower stratosphere and implications  

E-Print Network [OSTI]

fractionation processes. The results indicate that water substance in the upper troposphere does not follow a Rayleigh distillation model due to the presence of condensed phase water. Stratospheric abundances and climate of the upper troposphere and lower stratosphere (UT/LS). It is broadly known that most of the air

Gettelman, Andrew

Note: This page contains sample records for the topic "natural abundance half-life" 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

Consequences of habitat disturbance and recovery to recruitment and the abundance of kelp forest fishes  

E-Print Network [OSTI]

Consequences of habitat disturbance and recovery to recruitment and the abundance of kelp forest: Disturbance Kelp forest Macrocystis pyrifera Recovery Recruitment Reef fishes The complete or partial removal of kelp forests due to disturbance can alter species composition and cause large reductions

Anderson, Todd

282

ABUNDANCE AND VERTICAL DISTRIBUTION OF FISHES IN A COBBLE-BOTTOM KELP FOREST OFF  

E-Print Network [OSTI]

ABUNDANCE AND VERTICAL DISTRIBUTION OF FISHES IN A COBBLE-BOTTOM KELP FOREST OFF SAN ONOFRE composition,vertical distribution,and standingstockoffishes ina forest of giant kelp and a nearby kelp substrates, were rare or absent in these low-relief, cobble- bottom habitats. The species present in the kelp

283

USDA Forest Service Gen. Tech. Rep. PSW-152. 1995. 285 Abundance, Distribution, and Population Status of  

E-Print Network [OSTI]

Status of Marbled Murrelets in Alaska John F. Piatt1 Nancy L. Naslund2 The bulk of the North American or sparsely vegetated inland slopes (Day and others 1983; Marks, pers. comm.; Mendenhall 1992). Abundance between 1972 and 1992. Population declines may have resulted from cumulative effects of oil pollution

Standiford, Richard B.

284

Complex hydraulic and substrate variables limit freshwater mussel species richness and abundance  

E-Print Network [OSTI]

Complex hydraulic and substrate variables limit freshwater mussel species richness and abundance. We examined how substrate and complex hydraulic variables limit the distribution of freshwater mussels. We sampled mussels and measured substrate and hydraulic variables (at low and high flows) at 6

Vaughn, Caryn

285

Bacterial traits, organism mass, and numerical abundance in the detrital soil food web of Dutch  

E-Print Network [OSTI]

M and numerical abundance N. The microbial biomass and biodiversity of belowground fauna were and fragmentation. The quantity and diversity of litter are traditionally considered the bottom-up controlling donor). As the microbial biomass comprises the majority of the total biomass in soil, the role of top-down regulation

Cohen, Joel E.

286

NREL Highlights SCIENCE Use of Earth-abundant materials in solar absorber films  

E-Print Network [OSTI]

NREL Highlights SCIENCE Use of Earth-abundant materials in solar absorber films is critical of these materials could open new opportunities for introducing thin-film solar technologies that combine both low near the FeS2 thin-film surfaces and grain boundaries that limit its open-circuit voltage, rather than

287

The Effects of Disturbance Events on Abundance and Sex Ratios of a Terrestrial Turtle, Terrapene bauri  

E-Print Network [OSTI]

without catastrophic mortality, survivorship could be reduced following a disturbance, thus leading long-term effect on abundance as long as initial mortality is not severe and food resources remain. 2003). Both large (e.g., hurricanes) and small (e.g., wind damage in forested habitats) scale

Oli, Madan K.

288

Heavy Element Abundances in Presolar Silicon Carbide Grains from Low-Metallicity AGB Stars  

E-Print Network [OSTI]

Heavy Element Abundances in Presolar Silicon Carbide Grains from Low-Metallicity AGB Stars Peter explosions. Silicon carbide is the best studied presolar mineral. Based on its isotopic compositions the identified presolar minerals are diamond, silicon carbide (SiC), graphite, silicon nitride (Si3N4), corundum

289

FOREST STRUCTURE AND PREY ABUNDANCE IN WINTER HABITAT OF NORTHERN GOSHAWKS  

E-Print Network [OSTI]

suited to goshawk maneu- verability and hunting behavior) is more important than prey abundance. During their breeding-season home ranges in ponderosa pine forest during winter. Meanwhile, most males moved into lower squirrel [Sciurus aberti]). Goshawks minimized energy expense and thermal exposure of flight by caching

Beier, Paul

290

Monitoring Butterfly Abundance: Beyond Pollard Walks Jero^ me Pellet1,2  

E-Print Network [OSTI]

Monitoring Butterfly Abundance: Beyond Pollard Walks Je´ro^ me Pellet1,2 *, Jason T. Bried3 , David to the characteristics of the species under scrutiny and resources availability. Citation: Pellet J, Bried JT, Parietti D Copyright: � 2012 Pellet et al. This is an open-access article distributed under the terms of the Creative

Richner, Heinz

291

Abundance, Composition, and Sinking Rates of Fish Fecal Pellets in the Santa  

E-Print Network [OSTI]

Abundance, Composition, and Sinking Rates of Fish Fecal Pellets in the Santa Barbara Channel Grace.O. Box 1346, Gloucester Point, Virginia 23062, USA. Rapidly sinking fecal pellets are an important composition, particulate organic carbon/nitrogen (POC/PON), and sinking rates of fecal pellets produced

292

Distribution and abundance of alfalfa-field nematodes at various spatial scales  

E-Print Network [OSTI]

Distribution and abundance of alfalfa-field nematodes at various spatial scales B.L. Simmons *, R University, Fort Collins, CO 80523, USA 1. Introduction Alfalfa is one of the most economically important of Agriculture, National Agricul- tural Statistics Service). The alfalfa stem nematode, Ditylenchus dipsaci (Kuhn

Wall, Diana

293

Deep-Sea Research II 52 (2005) 799822 Top predator distribution and abundance across the  

E-Print Network [OSTI]

in abundance in the oceanic zone in 1998, 2001, and 2002, owing primarily to influxes of dark shearwaters 0967-0645/$ - see front matter r 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.dsr2 and location of water masses strong

294

Abundance and species composition of amphibians, small mammals, and songbirds in  

E-Print Network [OSTI]

buffer strips are left along water bodies after forest harvesting to protect water quality and fish report on changes in terrestrial vertebrate communities from pre- to post-harvest in experimentally levels, 3 replicates) before and after harvesting. Changes in small mammal or amphibian abundance were

Macdonald, Ellen

295

Oxygen Abundances in the Milky Way Using X-ray Absorption Measurements Towards Galaxy Clusters  

E-Print Network [OSTI]

We present measurements of the oxygen abundance of the Milky Way's ISM by observing the K-shell X-ray photoionization edge towards galaxy clusters. This effect is most easily observed towards objects with galactic columns (n_H) of a few times 1e21 cm^-2. We measure X-ray column densities towards 11 clusters and find that at high galactic columns above approximately 1e21 cm^-2 the X-ray columns are generally 1.5--3.0 times greater than the 21 cm H II columns, indicating that molecular clouds become an important contributor to n_H at higher columns. We find the average ISM oxygen abundance to be (O/H) = (4.85 +/- 0.06) x 10^-4, or 0.99 solar when using the most recent solar photospheric values. Since X-ray observations are sensitive to the total amount of oxygen present (gas + dust), these results indicate a high gas to dust ratio. Also, the oxygen abundances along lines of sight through high galactic columns (n_H) are the same as abundances through low columns, suggesting that the composition of denser clouds is similar to that of the more diffuse ISM.

Wayne H. Baumgartner; Richard F. Mushotzky

2005-09-21T23:59:59.000Z

296

RESIK Solar X-ray flare element abundances on a non-isothermal assumption  

E-Print Network [OSTI]

Solar X-ray spectra from the RESIK crystal spectrometer on the {\\em CORONAS-F} spacecraft (spectral range $3.3-6.1$~\\AA) are analyzed for thirty-three flares using a method to derive abundances of Si, S, Ar, and K, emission lines of which feature prominently in the spectra. For each spectrum, the method first optimizes element abundances then derives the differential emission measure as a function of temperature based on a procedure given by Sylwester et al. and Withbroe. This contrasts with our previous analyses of RESIK spectra in which an isothermal assumption was used. The revised abundances (on a logarithmic scale with $A({\\rm H}) = 12$) averaged for all the flares in the analysis are $A({\\rm Si}) = 7.53 \\pm 0.08$ (previously $7.89 \\pm 0.13$), $A({\\rm S}) = 6.91 \\pm 0.07$ ($7.16 \\pm 0.17$), $A({\\rm Ar}) = 6.47 \\pm 0.08$ ($6.45 \\pm 0.07$), and $A({\\rm K}) = 5.73 \\pm 0.19$ ($5.86 \\pm 0.20$), with little evidence for time variations of abundances within the evolution of each flare. Our previous estimates of...

Sylwester, B; Sylwester, J; Kepa, A

2015-01-01T23:59:59.000Z

297

Estimating abundance for a savanna elephant population using markresight methods: a case study for the Tembe  

E-Print Network [OSTI]

are difficult to count. Many elephant populations in Africa occur in such conditions. Estimates population size or densities for medium to large mammals living in wooded areas are poorly developed (CaroEstimating abundance for a savanna elephant population using mark­resight methods: a case study

Pretoria, University of

298

Solar Cells from Earth-Abundant Semiconductors with Plasmon-Enhanced Light Absorption  

SciTech Connect (OSTI)

Progress is reported in these areas: Plasmonic Light Trapping in Thin Film a-Si Solar Cells; Plasmonic Light Trapping in Thin InGaN Quantum Well Solar Cells; and Earth Abundant Cu{sub 2}O and Zn{sub 3}P{sub 2} Solar Cells.

Atwater, Harry

2012-04-30T23:59:59.000Z

299

Influence of landscape context on the abundance and diversity of bees in  

E-Print Network [OSTI]

Influence of landscape context on the abundance and diversity of bees in Mediterranean olive groves services and the maintenance of ecosystem diversity. As previous studies carried out in Central Europe of the surrounding landscape. Comparable studies have so far not been carried out in the Mediterranean region

Petanidou, Theodora

300

ON THE ABUNDANCE OF PRESOLAR SILICATE AND OXIDE GRAINS IN PRIMITIVE METEORITES.  

E-Print Network [OSTI]

ON THE ABUNDANCE OF PRESOLAR SILICATE AND OXIDE GRAINS IN PRIMITIVE METEORITES. A. Nguyen1 , E of presolar silicates in IDPs and meteorites [1-3] has opened new opportunities. Isotopic analyses of elements for presolar silicates to the CO3.0 meteorite ALH77307. This search resulted in the discovery of 9 presolar

Note: This page contains sample records for the topic "natural abundance half-life" 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

Bringing you a prosperous future where energy is clean, abundant, reliable and affordable Industrial Technologies Program  

E-Print Network [OSTI]

Technologies Program A Strong Energy Portfolio for a Strong America Energy efficiency and clean, renewableBringing you a prosperous future where energy is clean, abundant, reliable and affordable Industrial Technologies Program U.S. Department of Energy Office of Energy Efficiency and Renewable Energy

Beckermann, Christoph

302

Bringing you a prosperous future where energy is clean, abundant, reliable and affordable Industrial Technologies Program  

E-Print Network [OSTI]

Bringing you a prosperous future where energy is clean, abundant, reliable and affordable Industrial Technologies Program U.S. Department of Energy Office of Energy Efficiency and Renewable Energy for a comprehensive, physics- based model of dimensional changes and hot tearing. Hot Tear #12;Industrial Technologies

Beckermann, Christoph

303

Parvalbumin 3 is an Abundant Ca2+ Buffer in Hair Cells  

E-Print Network [OSTI]

Parvalbumin 3 is an Abundant Ca2+ Buffer in Hair Cells STEFAN HELLER,* ANDREA M. BELL, CHARLOTTE S parts of a hair cell. The Ca2+ concentration in ste- reocilia regulates adaptation and, through rapid saccular and chicken cochlear hair cells. We cloned cDNAs en- coding this protein from the corresponding

Hudspeth, A. James

304

Production ratio of meta-stable isomer in {sup 180}Ta by neutrino-induced reactions  

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 isomer residual 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 [Astrophysics, Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States)

2010-05-12T23:59:59.000Z

305

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

306

Oxygen, {\\alpha}-element and iron abundance distributions in the inner part of the Galactic thin disc  

E-Print Network [OSTI]

We derived elemental abundances in 27 Cepheids, the great majority situated within a zone of Galactocentric distances ranging from 5 to 7 kpc. One star of our sample, SU Sct, has a Galactocentric distance of about 3 kpc, and thus falls in a poorly investigated region of the inner thin disc. Our new results, combined with data on abundances in the very central part of our Galaxy taken from literature, show that iron, magnesium, silicon, sulfur, calcium and titanium LTE abundance radial distributions, as well as NLTE distribution of oxygen reveal a plateau-like structure or even positive abundance gradient in the region extending from the Galactic center to about 5 kpc.

Martin, R P; Kovtyukh, V V; Korotin, S A; Yegorova, I A; Saviane, Ivo

2015-01-01T23:59:59.000Z

307

REVISED NATURAL GAS MARKET ASSESSMENT  

E-Print Network [OSTI]

CALIFORNIA ENERGY COMMISSION REVISED NATURAL GAS MARKET ASSESSMENT In Support of the 2007's natural gas market. It covers natural gas demand, supply, infrastructure, price, and possible alternative and the related Scenarios Project, and additional updated information. California natural gas demand growth

308

Nature Conservancy University of Ottawa  

E-Print Network [OSTI]

. Natural Area Conservation Planning. 5. Natural Area Plan for the Frontenac Arch. 6. Management Planning is enough? Less than 10% of Canada's natural lands are in protected status. #12; Conservation of Private. The Conservancy is a non- advocacy, non- confrontational, private lands organization. Natural Area Property

Blouin-Demers, Gabriel

309

warnell school Forestry & Natural Resources  

E-Print Network [OSTI]

#12;#12;warnell school Forestry & Natural Resources 2009 Annual Report o #12;VisionTo be recognized as one of the top five forestry and natural resource programs in the United States. Mission's renewable natural resources; and to place latest ideas and technology in forestry and natural resource

Hall, Daniel

310

Natural Dark Energy  

E-Print Network [OSTI]

It is now well accepted that both Dark Matter and Dark Energy are required in any successful cosmological model. Although there is ample evidence that both Dark components are necessary, the conventional theories make no prediction for the contributions from each of them. Moreover, there is usually no intrinsic relationship between the two components, and no understanding of the nature of the mysteries of the Dark Sector. Here we suggest that if the Dark Side is so seductive then we should not be restricted to just 2 components. We further suggest that the most natural model has 5 distinct forms of Dark Energy in addition to the usual Dark Matter, each contributing precisely equally to the cosmic energy density budget.

Douglas Scott; Ali Frolop

2007-03-30T23:59:59.000Z

311

Natural gas repowering experience  

SciTech Connect (OSTI)

Gas Research Institute has led a variety of projects in the past two years with respect to repowering with natural gas. These activities, including workshops, technology evaluations, and market assessments, have indicated that a significant opportunity for repowering exists. It is obvious that the electric power industry`s restructuring and the actual implementation of environmental regulations from the Clean Air Act Amendments will have significant impact on repowering with respect to timing and ultimate size of the market. This paper summarizes the results and implications of these activities in repowering with natural gas. It first addresses the size of the potential market and discusses some of the significant issues with respect to this market potential. It then provides a perspective on technical options for repowering which are likely to be competitive in the current environment. Finally, it addresses possible actions by the gas industry and GRI to facilitate development of the repowering market.

Bautista, P.J.; Fay, J.M. [Gas Research Institute, Chicago, IL (United States); Gerber, F.B. [BENTEK Energy Research, DeSoto, TX (United States)

1995-12-31T23:59:59.000Z

312

Nature's Greatest Puzzles  

SciTech Connect (OSTI)

It is a pleasure to be part of the SLAC Summer Institute again, not simply because it is one of the great traditions in our field, but because this is a moment of great promise for particle physics. I look forward to exploring many opportunities with you over the course of our two weeks together. My first task in talking about Nature's Greatest Puzzles, the title of this year's Summer Institute, is to deconstruct the premise a little bit.

Quigg, Chris; /Fermilab

2005-02-01T23:59:59.000Z

313

Chlorophylls - natural solar cells  

E-Print Network [OSTI]

A molecular modeling study was conducted on a series of six natural occurring chlorophylls. Quantum chemistry calculated orbital energies were used to estimate frequency of transitions between occupied molecular orbital and unoccupied molecular orbital energy levels of chlorophyll molecules in vivo conditions in standard (ASTMG173) environmental conditions. Obtained results are in good agreement with energies necessary to fix the Magnesium atom by chlorophyll molecules and with occurrence of chlorophylls in living vegetal organisms.

Jantschi, Lorentz; Balan, Mugur C; Sestras, Radu E

2011-01-01T23:59:59.000Z

314

NATURAL RESOURCES ASSESSMENT  

SciTech Connect (OSTI)

The purpose of this report is to summarize the scientific work that was performed to evaluate and assess the occurrence and economic potential of natural resources within the geologic setting of the Yucca Mountain area. The extent of the regional areas of investigation for each commodity differs and those areas are described in more detail in the major subsections of this report. Natural resource assessments have focused on an area defined as the ''conceptual controlled area'' because of the requirements contained in the U.S. Nuclear Regulatory Commission Regulation, 10 CFR Part 60, to define long-term boundaries for potential radionuclide releases. New requirements (proposed 10 CFR Part 63 [Dyer 1999]) have obviated the need for defining such an area. However, for the purposes of this report, the area being discussed, in most cases, is the previously defined ''conceptual controlled area'', now renamed the ''natural resources site study area'' for this report (shown on Figure 1). Resource potential can be difficult to assess because it is dependent upon many factors, including economics (demand, supply, cost), the potential discovery of new uses for resources, or the potential discovery of synthetics to replace natural resource use. The evaluations summarized are based on present-day use and economic potential of the resources. The objective of this report is to summarize the existing reports and information for the Yucca Mountain area on: (1) Metallic mineral and mined energy resources (such as gold, silver, etc., including uranium); (2) Industrial rocks and minerals (such as sand, gravel, building stone, etc.); (3) Hydrocarbons (including oil, natural gas, tar sands, oil shales, and coal); and (4) Geothermal resources. Groundwater is present at the Yucca Mountain site at depths ranging from 500 to 750 m (about 1,600 to 2,500 ft) below the ground surface. Groundwater resources are not discussed in this report, but are planned to be included in the hydrology section of future revisions of the ''Yucca Mountain Site Description'' (CRWMS M&O 2000c).

D.F. Fenster

2000-12-11T23:59:59.000Z

315

General limit on the relation between abundances of D and $^7$Li in big bang nucleosynthesis with nucleon injections  

E-Print Network [OSTI]

The injections of energetic hadrons could have occurred in the early universe by decays of hypothetical long-lived exotic particles. The injections induce the showers of nonthermal hadrons via nuclear scattering. Neutrons generated at these events can react with $^7$Be nuclei and reduce $^7$Be abundance solving a problem of the primordial $^7$Li abundance. We suggest that thermal neutron injection is a way to derive a model independent conservative limit on the relation between abundances of D and $^7$Li in a hadronic energy injection model. We emphasize that an uncertainty in cross sections of inelastic $n+p$ scattering affects the total number of induced neutrons, which determines final abundances of D and $^7$Li. In addition, the annihilations of antinucleons with $^4$He result in higher D abundance and trigger nonthermal $^6$Li production. It is concluded that a reduction of $^7$Li abundance from a value in the standard big bang nucleosynthesis (BBN) model down to an observational two $\\sigma$ upper limit is necessarily accompanied by an undesirable increase of D abundance up to at least an observational 12 $\\sigma$ upper limit from observations of quasi-stellar object absorption line systems. The effects of antinucleons and secondary particles produced in the hadronic showers always lead to a severer constraint. The BBN models involving any injections of extra neutrons are thus unlikely to reproduce a small $^7$Li abundance consistent with observations.

Motohiko Kusakabe; Myung-Ki Cheoun; K. S. Kim

2014-04-11T23:59:59.000Z

316

OXYGEN ABUNDANCE OF OPEN CLUSTER DWARFS Department of Astronomy, Peking University, Beijing 100871, China; shenzx@bac.pku.edu.cn  

E-Print Network [OSTI]

OXYGEN ABUNDANCE OF OPEN CLUSTER DWARFS Z.-X. Shen Department of Astronomy, Peking University 100871, China Received 2005 June 30; accepted 2007 January 19 ABSTRACT We present oxygen abundances in the open cluster Pleiades derived from the [O i] k6300 forbidden line. Stellar parameters and oxygen

Liu, Xiaowei

317

Artificial nature : water infrastructure and its experience as natural space  

E-Print Network [OSTI]

This work is about water infrastructure and its experience as urban and natural space. It deals with the concepts of nature/geography, technology, and the integral experiential space by analyzing water dams and reservoirs ...

Demirta?, Fatma Asl?han, 1970-

2000-01-01T23:59:59.000Z

318

Natural gas monthly, April 1999  

SciTech Connect (OSTI)

The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. There are two feature articles in this issue: Natural gas 1998: Issues and trends, Executive summary; and Special report: Natural gas 1998: A preliminary summary. 6 figs., 28 tabs.

NONE

1999-05-06T23:59:59.000Z

319

Solar models with accretion. I. Application to the solar abundance problem  

E-Print Network [OSTI]

We generate new standard solar models using newly analyzed nuclear fusion cross sections and present results for helioseismic quantities and solar neutrino fluxes. We discuss the status of the solar abundance problem and investigate whether nonstandard solar models with accretion from the protoplanetary disk might alleviate the problem. We examine a broad range of possibilities, analyzing both metal-enriched and metal-depleted accretion models and exploring three scenarios for the timing of the accretion. Only partial solutions are found: one can bring either the depth of the convective zone or the surface helium abundance into agreement with helioseismic results, but not both simultaneously. In addition, detailed results for solar neutrino fluxes show that neutrinos are a competitive source of information about the solar core and can help constrain possible accretion histories of the Sun. Finally, we briefly discuss how measurements of solar neutrinos from the CN-cycle could shed light on the interaction bet...

Serenelli, Aldo M; Pena-Garay, Carlos

2011-01-01T23:59:59.000Z

320

Red Supergiant Stars as Cosmic Abundance Probes: KMOS Observations in NGC 6822  

E-Print Network [OSTI]

We present near-IR spectroscopy of red supergiant (RSG) stars in NGC 6822, obtained with the new VLT-KMOS instrument. From comparisons with model spectra in the J-band we determine the metallicity of 11 RSGs, finding a mean value of [Z] = -0.52 $\\pm$ 0.21 which agrees well with previous abundance studies of young stars and HII regions. We also find an indication for a low-significance abundance gradient within the central 1 kpc. We compare our results with those derived from older stellar populations and investigate the difference using a simple chemical evolution model. By comparing the physical properties determined for RSGs in NGC 6822 with those derived using the same technique in the Galaxy and the Magellanic Clouds, we show that there appears to be no significant temperature variation of RSGs with respect to metallicity, in contrast with recent evolutionary models.

Patrick, L R; Davies, B; Kudritzki, R-P; Gazak, J Z; Bergemann, M; Plez, B; Ferguson, A M N

2015-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "natural abundance half-life" 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

Wisconsin Natural Gas Prices  

Gasoline and Diesel Fuel Update (EIA)

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 Jun Jul(Summary) " ,"ClickPipelines About U.S.30NaturalThousandExtensions (Billion2008 2009 2010from2009 201060 5.56 5.28

322

Wyoming Natural Gas Prices  

Gasoline and Diesel Fuel Update (EIA)

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 Jun Jul(Summary) " ,"ClickPipelines About U.S.30NaturalThousandExtensions (Billion2008Sep-14 Oct-14Year (Million20082009 2010

323

Wyoming Natural Gas Prices  

Gasoline and Diesel Fuel Update (EIA)

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 Jun Jul(Summary) " ,"ClickPipelines About U.S.30NaturalThousandExtensions (Billion2008Sep-14 Oct-14Year (Million20082009

324

Wyoming Natural Gas Summary  

Annual Energy Outlook 2013 [U.S. Energy Information Administration (EIA)]

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 Jun Jul(Summary) " ,"ClickPipelinesProved Reserves (Billion Cubic Feet)Wyoming (Million Cubic Feet) Wyoming Natural3.40

325

NETL: Natural Gas Resources  

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 JunDatastreamsmmcrcalgovInstrumentsrucLas Conchas recovery challengeMultiscaleLogos NERSCJeffreyKey Actions forEnergy SystemsNatural

326

Iowa Natural Gas Prices  

Gasoline and Diesel Fuel Update (EIA)

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 Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 6330 0 14 15 0 0 0Year

327

Kansas Natural Gas Prices  

Gasoline and Diesel Fuel Update (EIA)

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 Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 6330 0 14 15 0 0ExtensionsYear

328

Kansas Natural Gas Prices  

Gasoline and Diesel Fuel Update (EIA)

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 Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 6330 0 14 15 0 0ExtensionsYearSep-14 Oct-14 Nov-14

329

Kentucky Natural Gas Prices  

Gasoline and Diesel Fuel Update (EIA)

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 Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 6330 0 14 15Industrial Consumers2009 2010 2011 2012

330

Kentucky Natural Gas Prices  

Gasoline and Diesel Fuel Update (EIA)

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 Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 6330 0 14 15Industrial Consumers2009 2010 2011

331

Louisiana Natural Gas Prices  

Gasoline and Diesel Fuel Update (EIA)

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 Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 6330 0 14343 342 3289 0 0FuelFuel2,208,9202009 2010

332

Louisiana Natural Gas Prices  

Gasoline and Diesel Fuel Update (EIA)

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 Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 6330 0 14343 342 3289 0 0FuelFuel2,208,9202009

333

Maine Natural Gas Prices  

Gasoline and Diesel Fuel Update (EIA)

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 Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 6330 0 14343 342CubicSep-14 Oct-14

334

Maryland Natural Gas Prices  

Gasoline and Diesel Fuel Update (EIA)

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 Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 6330 0 14343Decade Year-0Thousand Cubic Feet)2009

335

Maryland Natural Gas Prices  

Gasoline and Diesel Fuel Update (EIA)

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 Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 6330 0 14343Decade Year-0Thousand Cubic

336

Massachusetts Natural Gas Prices  

Gasoline and Diesel Fuel Update (EIA)

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 Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 6330 0 14343Decade81 170Feet) (Millionper8.36

337

Michigan Natural Gas Prices  

Gasoline and Diesel Fuel Update (EIA)

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 Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 6330 04 19 15 15 15 3Year Jan Feb2008 2009 20102009

338

Michigan Natural Gas Prices  

Gasoline and Diesel Fuel Update (EIA)

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 Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 6330 04 19 15 15 15 3Year Jan Feb2008 2009

339

Minnesota Natural Gas Prices  

Gasoline and Diesel Fuel Update (EIA)

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 Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 6330 04 19 15 15Thousand Cubic Feet) Decade5.68

340

Mississippi Natural Gas Prices  

Gasoline and Diesel Fuel Update (EIA)

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 Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 6330 04 19 15Year Jan Feb (Million2008 2009 20102009

Note: This page contains sample records for the topic "natural abundance half-life" 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

Mississippi Natural Gas Prices  

Gasoline and Diesel Fuel Update (EIA)

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 Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 6330 04 19 15Year Jan Feb (Million2008 2009

342

Missouri Natural Gas Prices  

Gasoline and Diesel Fuel Update (EIA)

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 Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 6330 04 19 15YearThousand Cubic Feet) Decade2009

343

Missouri Natural Gas Prices  

Gasoline and Diesel Fuel Update (EIA)

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 Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 6330 04 19 15YearThousand Cubic Feet)

344

Montana Natural Gas Prices  

Gasoline and Diesel Fuel Update (EIA)

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 Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 6330 04 19343 369 384Fuel ConsumptionThousand

345

Montana Natural Gas Prices  

Gasoline and Diesel Fuel Update (EIA)

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 Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 6330 04 19343 369 384Fuel ConsumptionThousand5.02

346

Colorado Natural Gas Prices  

Gasoline and Diesel Fuel Update (EIA)

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 Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 633 622 56623 46 (Million Cubic2009 2010 2011 2012

347

Colorado Natural Gas Prices  

Gasoline and Diesel Fuel Update (EIA)

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 Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 633 622 56623 46 (Million Cubic2009 2010 2011

348

Connecticut Natural Gas Prices  

Gasoline and Diesel Fuel Update (EIA)

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 Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 633 622 56623 4623 42 (Million Cubic5.51 4.62 4.78

349

Delaware Natural Gas Prices  

Gasoline and Diesel Fuel Update (EIA)

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 Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 633 622 56623 4623 42Year (Million CubicThousand6.92

350

Florida Natural Gas Prices  

Gasoline and Diesel Fuel Update (EIA)

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 Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 6330 0 1 0 0 0 1979-2013Fuel2009 2010 2011 2012 2013

351

Florida Natural Gas Prices  

Gasoline and Diesel Fuel Update (EIA)

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 Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 6330 0 1 0 0 0 1979-2013Fuel2009 2010 2011 2012

352

Georgia Natural Gas Prices  

Gasoline and Diesel Fuel Update (EIA)

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 Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 6330 0 1 0 058.5 57.1 54.8IndustrialThousand

353

Hawaii Natural Gas Prices  

Gasoline and Diesel Fuel Update (EIA)

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 Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 6330 0 1 0 058.588,219Thousand Cubic Feet)

354

Historical Natural Gas Annual  

Gasoline and Diesel Fuel Update (EIA)

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 Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 6330 0 1 0Decade Year-0 Year-1 Year-2Thousand6 The

355

Historical Natural Gas Annual  

Gasoline and Diesel Fuel Update (EIA)

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 Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 6330 0 1 0Decade Year-0 Year-1 Year-2Thousand6 The7

356

Historical Natural Gas Annual  

Gasoline and Diesel Fuel Update (EIA)

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 Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 6330 0 1 0Decade Year-0 Year-1 Year-2Thousand6 The78

357

Idaho Natural Gas Prices  

Gasoline and Diesel Fuel Update (EIA)

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 Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 6330 0 1 0Decade (Million Cubic Feet)

358

Illinois Natural Gas Prices  

Gasoline and Diesel Fuel Update (EIA)

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 Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 6330 0 1 0DecadeWithdrawals (MillionPlant2009 2010

359

Illinois Natural Gas Prices  

Gasoline and Diesel Fuel Update (EIA)

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 Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 6330 0 1 0DecadeWithdrawals (MillionPlant2009

360

Illinois Natural Gas Summary  

Gasoline and Diesel Fuel Update (EIA)

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 Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 6330 0 1 0DecadeWithdrawalsDecade Year-0 Year-1Prices

Note: This page contains sample records for the topic "natural abundance half-life" 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

Indiana Natural Gas Prices  

Gasoline and Diesel Fuel Update (EIA)

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 Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 6330 0 14 15 0 0 0 0WithdrawalsPlant

362

Indiana Natural Gas Prices  

Gasoline and Diesel Fuel Update (EIA)

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 Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 6330 0 14 15 0 0 0 0WithdrawalsPlantSep-14 Oct-14

363

Food abundance does not determine bird use of early-successional habitat.  

SciTech Connect (OSTI)

Abstract. Few attempts have been made to experimentally address the extent to which temporal or spatial variation in food availability influences avian habitat use. We used an experimental approach to investigate whether bird use differed between treated (arthropods reduced through insecticide application) and control (untreated) forest canopy gaps within a bottomland hardwood forest in the Upper Coastal Plain of South Carolina, USA. Gaps were two- to three-year-old group selection timber harvest openings of three sizes (0.13, 0.26, and 0.50 ha). Our study was conducted during four bird use periods (spring migration, breeding, post-breeding, and fall migration) in 2002 and 2003. Arthropods were reduced in treated gaps by 68% in 2002 and 73% in 2003. We used mist-netting captures and foraging attack rates to assess the influence of arthropod abundance on avian habitat use. Evidence that birds responded to arthropod abundance was limited and inconsistent. In 2002, we generally captured more birds in treated gaps of the smallest size (0.13 ha) and fewer birds in treated gaps of the larger sizes. In 2003, we recorded few differences in the number of captures in treated and control gaps. Foraging attack rates generally were lower in treated than in control gaps, indicating that birds were able to adapt to the reduced food availability and remain in treated gaps. We conclude that arthropod abundance was not a proximate factor controlling whether forest birds used our gaps. The abundance of food resources may not be as important in determining avian habitat selection as previous research has indicated, at least for passerines in temperate subtropical regions.

Champlin, Tracey B.; Kilgo, John C.; Moorman, Christopher E.

2009-06-01T23:59:59.000Z

364

The Texas Quail Index: Evaluating Predictors of Quail Abundance Using Citizen Science  

E-Print Network [OSTI]

Bird survey, 1967?2006 (Sauer et. al 2007) .............. 2 1.2 Distribution of Texas Quail Index study sites by county, 2002?2006 ....... 6 1.3 The 10 ecoregions of Texas as described by Gould (1975) ....................... 7 1... of the Texas Quail Index utilized scent-stations as an index of the relative abundance of mesomammal nest predators ........................ 20 2.4 Mean (? standard error) spring cock-call counts of all Texas Quail Index sites from 2002...

Reyna, Kelly Shane

2009-05-15T23:59:59.000Z

365

Natural ventilation generates building form  

E-Print Network [OSTI]

Natural ventilation is an efficient design strategy for thermal comfort in hot and humid climates. The building forms can generate different pressures and temperatures to induce natural ventilation. This thesis develops a ...

Chen, Shaw-Bing

1996-01-01T23:59:59.000Z

366

Natural Gas Exports from Iran  

Reports and Publications (EIA)

This assessment of the natural gas sector in Iran, with a focus on Iran’s natural gas exports, was prepared pursuant to section 505 (a) of the Iran Threat Reduction and Syria Human Rights Act of 2012 (Public Law No: 112-158). As requested, it includes: (1) an assessment of exports of natural gas from Iran; (2) an identification of the countries that purchase the most natural gas from Iran; (3) an assessment of alternative supplies of natural gas available to those countries; (4) an assessment of the impact a reduction in exports of natural gas from Iran would have on global natural gas supplies and the price of natural gas, especially in countries identified under number (2); and (5) such other information as the Administrator considers appropriate.

2012-01-01T23:59:59.000Z

367

Uranium in Framboidal Pyrite from a Naturally Bioreduced Alluvial Sediment  

SciTech Connect (OSTI)

Samples of a naturally bioreduced, U contaminated aquifer sediment from Rifle, CO were characterized with various microscopic and spectroscopic techniques and wet chemical extraction methods. The objective was to investigate U association and interaction with the soil minerals of the sediment. The naturally bioreduced sediment was elevated in solid-phase U, total organic carbon and acid-volatile sulfide, and depleted in bioavailable Fe(III) indicating that sulfate and Fe(III) reduction have occurred naturally in the sediment. XRD and SEM/EDS analyses demonstrated that framboidal pyrites (FeS2) of different sizes (~10 – 20 ?m in diameter), and of various microcrystal morphology, degree of surface weathering and internal porosity were abundant in the < 53 ?m fraction (silt+clay) of the sediment. EMP, XRF, EXAFS, and XANES measurements confirmed that U interacted mostly with framboidal pyrite and that both U(VI) and U(IV) were associated with the framboids indicating partial reduction of surface bounded U(VI). Results demonstrated that U(VI) may be sorbed and reduced on framboidal pyrite, and both sorption and reduction were important pathways of U(VI) attenuation in this naturally bioreduced sediment. A fuller understanding of U(VI) fate in this unique system could help in developing remedial measures for other U contaminated aquifers.

Qafoku, Nikolla; Kukkadapu, Ravi K.; McKinley, James P.; Arey, Bruce W.; Kelly, Shelly D.; Wang, Chong M.; Resch, Charles T.; Long, Philip E.

2009-10-07T23:59:59.000Z

368

Constraining the abundances of complex organics in the inner regions of solar-type protostars  

E-Print Network [OSTI]

The high abundances of Complex Organic Molecules (COMs) with respect to methanol, the most abundant COM, detected towards low-mass protostars, tend to be underpredicted by astrochemical models. This discrepancy might come from the large beam of the single-dish telescopes, encompassing several components of the studied protostar, commonly used to detect COMs. To address this issue, we have carried out multi-line observations of methanol and several COMs towards the two low-mass protostars NGC1333-IRAS2A and -IRAS4A with the Plateau de Bure interferometer at an angular resolution of 2 arcsec, resulting in the first multi-line detection of the O-bearing species glycolaldehyde and ethanol and of the N-bearing species ethyl cyanide towards low-mass protostars other than IRAS 16293. The high number of detected transitions from COMs (more than 40 methanol transitions for instance) allowed us to accurately derive the source size of their emission and the COMs column densities. The COMs abundances with respect to meth...

Taquet, Vianney; Ceccarelli, Cecilia; Neri, Roberto; Kahane, Claudine; Charnley, Steven B

2015-01-01T23:59:59.000Z

369

Arthropod abundance and seasonal bird use of bottomland forest harvest gaps.  

SciTech Connect (OSTI)

We investigated the influence of arthropod abundance and vegetation structure on shifts in avian use of canopy gap, gap edge, and surrounding forest understory in a bottomland hardwood forest in the Upper Coastal Plain of South Carolina. We compared captures of foliage-gleaning birds among locations during four periods (spring migration, breeding, post-breeding, and fall migration). Foliage arthropod densities were greatest in the forest understory in all four seasons, but understory vegetation density was greatest in gaps. Foliage-gleaning bird abundance was positively associated with foliage-dwelling arthropods during the breeding (F = 18.5, P < 0.001) and post-breeding periods (F = 9.4, P = 0.004), and negatively associated with foliage-dwelling arthropods during fall migration (F = 5.4, P = 0.03). Relationships between birds and arthropods were inconsistent, but the arthropod prey base seemed to be least important during migratory periods. Conversely, bird captures were positively correlated with understory vegetation density during all four periods (P < 0.001). Our study suggests high bird abundance associated with canopy gaps during the non-breeding period resulted less from high arthropod food resource availability than from complex understory and midstory vegetation structure.

Moorman, Christopher, E.; Bowen, Liessa T.; Kilgo, John, C.; Hanula, James, L.; Horn, Scott; Ulyshen, Michael, D.

2012-03-01T23:59:59.000Z

370

Chemical Abundances of the Highly Obscured Galactic Globular Clusters 2MASS GC02 and Mercer 5  

E-Print Network [OSTI]

We present the first high spectral resolution abundance analysis of two newly discovered Galactic globular clusters, namely Mercer 5 and 2MASS GC02 residing in regions of high interstellar reddening in the direction of the Galactic center. The data were acquired with the Phoenix high-resolution near-infrared echelle spectrograph at Gemini South (R~50000) in the 15500.0 A - 15575.0 A spectral region. Iron, Oxygen, Silicon, Titanium and Nickel abundances were derived for two red giant stars, in each cluster, by comparing the entire observed spectrum with a grid of synthetic spectra generated with MOOG. We found [Fe/H] values of -0.86 +/- 0.12 and -1.08 +/- 0.13 for Mercer 5 and 2MASS GC02 respectively. The [O/Fe], [Si/Fe] and [Ti/Fe] ratios of the measured stars of Mercer 5 follow the general trend of both bulge field and cluster stars at this metallicity, and are enhanced by > +0.3. The 2MASS GC02 stars have relatively lower ratios, but still compatible with other bulge clusters. Based on metallicity and abund...

Penaloza, Francisco; Vasquez, Sergio; Borissova, Jura; Kurtev, Radostin; Zoccali, Manuela

2015-01-01T23:59:59.000Z

371

The Abundance Distribution in the Extrasolar-Planet Host Star HD19994  

E-Print Network [OSTI]

Abundances of 22 elements have been determined from a high-resolution, high signal-to-noise spectrum of HD19994, a star recently announced as harboring an extrasolar planet. A detailed spectroscopic analysis of this stars finds it to have a mass of 1.2+/-0.1Msun. HD19994 is found to be slightly enriched in "metals" relative to the Sun 9[Fe/H]=+0.09+/-0.05 and an average of all metals of [m/H]=+0.13), as are most stars known with extrasolar planets. In a search for possible signatures of accretion of metal-rich gas onto the parent stars (using HD19994 and published abundances for other stars), it is found that a small subset of stars with planets exhibit a trend of increasing [X/H] with increasing condensation temperature for a given element X. This trend may point to the accretion of chemically fractionated solid material into the outer (thin) convection zones of these solar-type stars. It is also found that this small group of stars exhibiting an accretion signature all have large planets orbiting much closer than is found, in general, for stars with planets not showing this peculiar abundance trend, suggesting a physical link between accretion and orbital separation. In addition, the stars showing evidence of fractionated accretion are, on average, of larger mass (1.2Msun) than stars not showing measurable evidence of accretion (1.0Msun).

Verne V. Smith; Katia Cunha; Daniela Lazzaro

2001-03-04T23:59:59.000Z

372

Diversity of abundance patterns of neutron-capture elements in very metal-poor stars  

SciTech Connect (OSTI)

Observations of Very Metal-Poor stars indicate that there are at least two sites to r-process; “weak r-process” and “main r-process”. A question is whether these two are well separated or there exists a variation in the r-process. We present the results of abundance analysis of neutron-capture elements in the two Very Metal-Poor stars HD107752 and HD110184 in the Milky Way halo observed with the Subaru Telescope HDS. The abundance patterns show overabundace at light n-capture elements (e.g. Sr, Y), inferring the element yielding of weak r-process, while heavy neutron-capture elements (e.g. Ba, Eu) are deficient; however, the overabundance of light ones is not as significant as that previously found in stars representing the weak r-process (e.g. HD122563; Honda et al. 2006). Our study show diversity in the abundance patterns from light to heavy neutron-capture elements in VMP stars, suggesting a variation in r-process, which may depend on electron fraction of environment.

Aoki, Misa; Ishimaru, Yuhri [International Christian University 10-2, Osawa, Mitaka, Tokyo 181-0015 (Japan); Aoki, Wako; Wanajo, Shinya [National Astronomical Observatory of Japan (NAOJ) 2-21-1, Osawa, Mitaka, Tokyo 181-8588 (Japan)

2014-05-02T23:59:59.000Z

373

Solar Carbon Monoxide, Thermal Profiling, and the Abundances of C, O, and their Isotopes  

E-Print Network [OSTI]

A solar photospheric "thermal profiling" analysis is presented, exploiting the infrared rovibrational bands of carbon monoxide (CO) as observed with the McMath-Pierce Fourier transform spectrometer (FTS) at Kitt Peak, and from above the Earth's atmosphere by the Shuttle-borne ATMOS experiment. Visible continuum intensities and center-limb behavior constrained the temperature profile of the deep photosphere, while CO center-limb behavior defined the thermal structure at higher altitudes. The oxygen abundance was self consistently determined from weak CO absorptions. Our analysis was meant to complement recent studies based on 3-D convection models which, among other things, have revised the historical solar oxygen (and carbon) abundance downward by a factor of nearly two; although in fact our conclusions do not support such a revision. Based on various considerations, an oxygen abundance of 700+/-100 ppm (parts per million relative to hydrogen) is recommended; the large uncertainty reflects the model sensitivity of CO. New solar isotopic ratios also are reported for 13C, 17O, and 18O.

Thomas R. Ayres; Claude Plymate; Christoph U. Keller

2006-06-07T23:59:59.000Z

374

Fe and Al Abundances for 180 Red Giants in the Globular Cluster Omega Centauri (NGC 5139)  

E-Print Network [OSTI]

We present radial velocities, Fe, and Al abundances for 180 red giant branch (RGB) stars in the Galactic globular cluster Omega Centauri ($\\omega$ Cen). The majority of our data lie in the range 11.0$Al/Fe] ratios exhibit large star--to--star scatter for all populations, with the more than 1.0 dex range of [Al/Fe] decreasing for stars more metal--rich than [Fe/H]$\\sim$--1.4. The minimum [Al/Fe] abundance observed for all metallicity populations is [Al/Fe]$\\sim$+0.15. The maximum abundance of log $\\epsilon$(Al) is reached for stars with [Fe/H]$\\sim$--1.4 and does not increase further with stellar metallicity. We interpret these results as evidence for type II SNe providing the minimum [Al/Fe] ratio and a mass spectrum of intermediate mass asymptotic giant branch stars causing the majority of the [Al/Fe] scatter. These results seem to fit in the adopted scheme that star formation occurred in $\\omega$ Cen over $>$1 Gyr.

Christian I. Johnson; Catherine A. Pilachowski; Jennifer Simmerer; Dustin Schwenk

2008-04-16T23:59:59.000Z

375

A Compiled Catalogue of Spectroscopically Determined Elemental Abundances for Stars with Accurate Parallaxes. I.Magnesium  

E-Print Network [OSTI]

We present a compiled catalogue of effective temperatures, surface gravities, iron and magnesium abundances, distances, velocity components, and orbital elements for stars in the solar neighborhood. The atmospheric parameters and iron abundances are averages of published values derived from model synthetic spectra for a total of about 2000 values in 80 publications. Our relative magnesium abundances were found from 1412 values in 31 publications for 876 dwarfs and subgiants using a three-step iteration averaging procedure, with weights assigned to each source of data as well as to each individual determination and taking into account systematic deviations of each scale relative to the reduced mean scale. The estimated assumed completeness for data sources containing more than five stars, up to late December 2003, exceeds 90%. For the vast majority of stars in the catalogue, the spatial velocity components were derived from modern high-precision astrometric observations, and their Galactic orbit elements were computed using a three-component model of the Galaxy, consisting of a disk, a bulge, and a massive extended halo.

T. V. Borkova; V. A. Marsakov

2005-03-28T23:59:59.000Z

376

Neon Lights Up a Controversy: the Solar Ne/O Abundance  

E-Print Network [OSTI]

The standard solar model was so reliable that it could predict the existence of the massive neutrino. Helioseismology measurements were so precise that they could determine the depth of the convection zone. This agreement between theory and observation was the envy of all astrophysics -- until recently when sophisticated three-dimensional hydrodynamic calculations of the solar atmosphere reduced the metal content by a factor of almost two. Antia & Basu (2005) suggested that a higher value of the solar neon abundance, Ne/O = 0.52, would resolve this controversy. Drake & Testa (2005) presented strong evidence in favor of this idea from a sample of 21 Chandra stars with enhanced values of the neon abundance, Ne/O = 0.41. In this paper, we have analyzed solar active region spectra from the archive of the Flat Crystal Spectrometer on Solar Maximum Mission, a NASA mission from the 1980s, as well as full-Sun spectra from the pioneering days of X-ray astronomy in the 1960s. These data seem consistent with the standard neon-to-oxygen abundance value, Ne/O = 0.15 (Grevesse & Sauval 1998). If these results prove to be correct, than the enhanced-neon hypothesis will not resolve the current controversy.

J. T. Schmelz; K. Nasraoui; J. K. Roames; L. A. Lippner; J. W. Garst

2005-10-07T23:59:59.000Z

377

Lithium abundances in globular cluster giants: NGC 6218 (M12) and NGC 5904 (M5)  

E-Print Network [OSTI]

Convergent lines of evidence suggest that globular clusters host multiple stellar populations. It appears that they experience at least two episodes of star formation whereby a fraction of first-generation stars contribute astrated ejecta to form the second generation(s). To identify the polluting progenitors we require distinguishing chemical signatures such as that provided by lithium. Theoretical models predict that lithium can be synthesised in AGB stars, whereas no net Li production is expected from other candidates. It has been shown that in order to reproduce the abundance pattern found in M4, Li production must occur within the polluters, favouring the AGB scenario. Here we present Li and Al abundances for a large sample of RGB stars in M12 and M5. These clusters have a very similar metallicity, whilst demonstrating differences in several cluster properties. Our results indicate that the first-generation and second-generation stars share the same Li content in M12; we recover an abundance pattern simi...

D'Orazi, Valentina; Gratton, Raffaele G; Lattanzio, John C; Bragaglia, Angela; Carretta, Eugenio; Lucatello, Sara; Momany, Yazan

2014-01-01T23:59:59.000Z

378

Solar Flare Element Abundances from the Solar Assembly for X-rays (SAX) on MESSENGER  

E-Print Network [OSTI]

X-ray spectra in the range $1.5-8.5$~keV have been analyzed for 526 large flares detected with the Solar Assembly for X-rays (SAX) on the Mercury {\\em MESSENGER} spacecraft between 2007 and 2013. For each flare, the temperature and emission measure of the emitting plasma were determined from the spectrum of the continuum. In addition, with the SAX energy resolution of 0.6 keV (FWHM) at 6~keV, the intensities of the clearly resolved Fe-line complex at 6.7~keV and the Ca-line complex at 3.9~keV were determined, along with those of unresolved line complexes from S, Si, and Ar at lower energies. Comparisons of these line intensities with theoretical spectra allow the abundances of these elements relative to hydrogen to be derived, with uncertainties due to instrument calibration and the unknown temperature distribution of the emitting plasma. While significant deviations are found for the abundances of Fe and Ca from flare to flare, the abundances averaged over all flares are found to be enhanced over photospheri...

Dennis, B R; Schwartz, R A; Tolbert, A K; Starr, R D; Nittler, L R

2015-01-01T23:59:59.000Z

379

Natural gas monthly, June 1997  

SciTech Connect (OSTI)

The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. 6 figs., 24 tabs.

NONE

1997-06-01T23:59:59.000Z

380

Natural gas monthly, November 1993  

SciTech Connect (OSTI)

The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground state data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information.

Not Available

1993-11-29T23:59:59.000Z

Note: This page contains sample records for the topic "natural abundance half-life" 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

Natural Resource Management Plan Update  

E-Print Network [OSTI]

wood industry, some farming in area of Solar Farm 3 #12;History of Natural Resource Management Formal

Homes, Christopher C.

382

Natural gas monthly: December 1993  

SciTech Connect (OSTI)

The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. Articles are included which are designed to assist readers in using and interpreting natural gas information.

Not Available

1993-12-01T23:59:59.000Z

383

Natural gas monthly, June 1999  

SciTech Connect (OSTI)

The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. 6 figs., 25 tabs.

NONE

1999-06-01T23:59:59.000Z

384

Natural gas monthly, July 1998  

SciTech Connect (OSTI)

The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. 6 figs., 25 tabs.

NONE

1998-07-01T23:59:59.000Z

385

Natural gas monthly, April 1995  

SciTech Connect (OSTI)

The Natural Gas Monthly highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. 6 figs., 31 tabs.

NONE

1995-04-27T23:59:59.000Z

386

Natural gas monthly, October 1998  

SciTech Connect (OSTI)

The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. 6 figs., 27 tabs.

NONE

1998-10-01T23:59:59.000Z

387

Natural Gas Monthly, March 1996  

SciTech Connect (OSTI)

The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information.

NONE

1996-03-25T23:59:59.000Z

388

Natural gas monthly, June 1998  

SciTech Connect (OSTI)

The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. 6 figs., 27 tabs.

NONE

1998-06-01T23:59:59.000Z

389

Natural gas monthly, May 1999  

SciTech Connect (OSTI)

The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time the NGM features articles designed to assist readers in using and interpreting natural gas information. 6 figs., 27 tabs.

NONE

1999-05-01T23:59:59.000Z

390

wind engineering & natural disaster mitigation  

E-Print Network [OSTI]

wind engineering & natural disaster mitigation #12;wind engineering & natural disaster mitigation Investment WindEEE Dome at Advanced Manufacturing Park $31million Insurance Research Lab for Better Homes $8million Advanced Facility for Avian Research $9million #12;wind engineering & natural disaster mitigation

Denham, Graham

391

LIQUEFIED NATURAL GAS IN CALIFORNIA  

E-Print Network [OSTI]

CALIFORNIA ENERGY COMMISSION LIQUEFIED NATURAL GAS IN CALIFORNIA: HISTORY, RISKS, AND SITING Tyler Contributors Dave Maul Manager NATURAL GAS & SPECIAL PROJECTS OFFICE Terrence O'Brien, Deputy Commissioner and Leader of the Governor's Natural Gas Working Group #12;This paper was prepared as the result

392

warnell school Forestry & Natural Resources  

E-Print Network [OSTI]

warnell school Forestry & Natural Resources 2010 Annual Report o #12;VisionTo be recognized as one of the top five forestry and natural resource programs in the United States. MissionTo prepare resources; and to place latest ideas and technology in forestry and natural resource management into real

Hall, Daniel

393

Natural gas monthly, January 1999  

SciTech Connect (OSTI)

The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. 6 figs., 28 tabs.

NONE

1999-02-01T23:59:59.000Z

394

NATIONAL MUSEUM OF NATURAL HISTORY  

E-Print Network [OSTI]

NATIONAL MUSEUM OF NATURAL HISTORY Annual Report 2004 #12;2 NATIONAL MUSEUM OF NATURAL HISTORY · www.mnh.si.edu The revitalization of the National Museum of Natural History proceeded at a rapid pace, innovation and solid groundwork for future growth. The Museum's agenda is an active one. As with any

Mathis, Wayne N.

395

Field Museum of Natural History  

E-Print Network [OSTI]

Field Museum of Natural History Financial Statements as of and for the Years Ended December 31' Report #12;FIELD MUSEUM OF NATURAL HISTORY TABLE OF CONTENTS Page INDEPENDENT AUDITORS' REPORT 1 AUDITORS' REPORT To the Board of Trustees of Field Museum of Natural History: We have audited

Patterson, Bruce D.

396

Field Museum of Natural History  

E-Print Network [OSTI]

Field Museum of Natural History Financial Statements as of and for the Years Ended December 31 Auditors' Report #12;FIELD MUSEUM OF NATURAL HISTORY TABLE OF CONTENTS Page INDEPENDENT AUDITORS' REPORT 1 Expenditures 22­23 #12;INDEPENDENT AUDITORS' REPORT To the Board of Trustees of Field Museum of Natural History

Patterson, Bruce D.

397

Natural gas monthly, November 1998  

SciTech Connect (OSTI)

The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. 6 figs., 27 tabs.

NONE

1998-11-01T23:59:59.000Z

398

Natural gas monthly, February 1999  

SciTech Connect (OSTI)

The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. 6 figs., 28 tabs.

NONE

1999-02-01T23:59:59.000Z

399

Natural Gas Monthly, October 1993  

SciTech Connect (OSTI)

The (NGM) Natural Gas Monthly highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. This month`s feature articles are: US Production of Natural Gas from Tight Reservoirs: and Expanding Rule of Underground Storage.

Not Available

1993-11-10T23:59:59.000Z

400

Natural gas monthly, April 1997  

SciTech Connect (OSTI)

The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are present3ed each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. The feature article is entitled ``Natural gas pipeline and system expansions.`` 6 figs., 27 tabs.

NONE

1997-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "natural abundance half-life" 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

Natural gas monthly, July 1997  

SciTech Connect (OSTI)

The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. The feature article this month is entitled ``Intricate puzzle of oil and gas reserves growth.`` A special report is included on revisions to monthly natural gas data. 6 figs., 24 tabs.

NONE

1997-07-01T23:59:59.000Z

402

Natural gas monthly, December 1997  

SciTech Connect (OSTI)

The Natural Gas Monthly highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. The article this month is entitled ``Recent Trends in Natural Gas Spot Prices.`` 6 figs., 27 tabs.

NONE

1997-12-01T23:59:59.000Z

403

Heat distribution by natural convection  

SciTech Connect (OSTI)

Natural convection can provide adequate heat distribution in many situtations that arise in buildings. This is appropriate, for example, in passive solar buildings where some rooms tend to be more strongly solar heated than others or to reduce the number of heating units required in a building. Natural airflow and heat transport through doorways and other internal building apertures is predictable and can be accounted for in the design. The nature of natural convection is described, and a design chart is presented appropriate to a simple, single-doorway situation. Natural convective loops that can occur in buildings are described and a few design guidelines are presented.

Balcomb, J.D.

1985-01-01T23:59:59.000Z

404

Natural gas monthly, October 1997  

SciTech Connect (OSTI)

The Natural Gas Monthly highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. The feature article in this issue is a special report, ``Comparison of Natural Gas Storage Estimates from the EIA and AGA.`` 6 figs., 26 tabs.

NONE

1997-10-01T23:59:59.000Z

405

Natural gas monthly, May 1997  

SciTech Connect (OSTI)

The Natural Gas Monthly highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. The feature article this month is ``Restructuring energy industries: Lessons from natural gas.`` 6 figs., 26 tabs.

NONE

1997-05-01T23:59:59.000Z

406

Natural gas monthly, October 1996  

SciTech Connect (OSTI)

The Natural Gas Monthly (NGM) is prepared in the Data Operations Branch of the Reserves and Natural Gas Division, Office of Oil and Gas, Energy Information Administration (EIA), U.S. Department of Energy (DOE). The NGM highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information.

NONE

1996-10-01T23:59:59.000Z

407

Natural gas monthly, June 1996  

SciTech Connect (OSTI)

The natural gas monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. The feature article for this month is Natural Gas Industry Restructuring and EIA Data Collection.

NONE

1996-06-24T23:59:59.000Z

408

ELEMENTAL ABUNDANCES IN THE X-RAY GAS OF EARLY-TYPE GALAXIES WITH XMM-NEWTON AND CHANDRA OBSERVATIONS  

SciTech Connect (OSTI)

The source of hot gas in elliptical galaxies is thought to be due to stellar mass loss, with contributions from supernova (SN) events and possibly from infall from a surrounding environment. This picture predicts supersolar values for the metallicity of the gas toward the inner part of the galaxy, which can be tested by measuring the gas phase abundances. We use high-quality data for 10 nearby early-type galaxy from XMM-Newton, featuring both the European Photon Imaging Camera and the Reflection Grating Spectrometer, where the strongest emission lines are detected with little blending; some Chandra data are also used. We find excellent consistency in the elemental abundances between the different XMM-Newton instruments and good consistency with Chandra. Differences in abundances with aperture size and model complexity are examined, but large differences rarely occur. For a two-temperature thermal model plus a point source contribution, the median Fe and O abundances are 0.86 and 0.44 of the solar value, while Si and Mg abundances are similar to that for Fe. This is similar to stellar abundances for these galaxies but SNe were expected to enhance the gas phase abundances considerably, which is not observed.

Ji Jun; Irwin, Jimmy A.; Athey, Alex; Bregman, Joel N.; Lloyd-Davies, Edward J. [Department of Astronomy, University of Michigan, Ann Arbor, MI 48109 (United States)], E-mail: jijun@umich.edu, E-mail: jairwin@umich.edu, E-mail: athey@arlut.utexas.edu, E-mail: jbregman@umich.edu, E-mail: radix@freeshell.org

2009-05-10T23:59:59.000Z

409

Are oxygen and neon enriched in PNe and is the current solar Ne/O abundance ratio underestimated?  

E-Print Network [OSTI]

A thorough critical literature survey has been carried out for reliable measurements of oxygen and neon abundances of planetary nebulae (PNe) and HII regions. By contrasting the results of PNe and of HII regions, we aim to address the issues of the evolution of oxygen and neon in the interstellar medium (ISM) and in the late evolutionary phases of low- and intermediate-mass stars (LIMS), as well as the currently hotly disputed solar Ne/O abundance ratio. Through the comparisons, we find that neon abundance and Ne/O ratio increase with increasing oxygen abundance in both types of nebulae, with positive correlation coefficients larger than 0.75. The correlations suggest different enrichment mechanisms for oxygen and neon in the ISM, in the sense that the growth of neon is delayed compared to oxygen. The differences of abundances between PNe and HII regions, are mainly attributed to the results of nucleosynthesis and dredge-up processes that occurred in the progenitor stars of PNe. We find that both these alpha-elements are significantly enriched at low metallicity (initial oxygen abundance oxygen in intermediate mass stars (IMS) of low initial metallicities and in more massive stars, a conjecture that requires verification by further theoretical studies. This result also strongly suggests that both the solar neon abundance and the Ne/O ratio should be revised upwards by ~0.22 dex from the Asplund, Grevesse & Sauval values or by ~0.14 dex from the Grevesse & Sauval values.

W. Wang; X. -W. Liu

2008-06-13T23:59:59.000Z

410

letters to nature NATURE |VOL 404 |2 MARCH 2000 |www.nature.com 69  

E-Print Network [OSTI]

and the effects nonprecipitating clouds have on aerosol size distribution. J. Geophys. Res. 99, 14443±14459 (1994 determining their size distribution. J. Geophys. Res. 102, 21315±21328 (1997). 8. Hoppel, W. A., Frick, G. Mletters to nature NATURE |VOL 404 |2 MARCH 2000 |www.nature.com 69 subsequent self-coagulation

Larson, Kristine

411

The solar photospheric abundance of hafnium and thorium. Results from CO5BOLD 3D hydrodynamic model atmospheres  

E-Print Network [OSTI]

Context: The stable element hafnium (Hf) and the radioactive element thorium (Th) were recently suggested as a suitable pair for radioactive dating of stars. The applicability of this elemental pair needs to be established for stellar spectroscopy. Aims: We aim at a spectroscopic determination of the abundance of Hf and Th in the solar photosphere based on a \\cobold 3D hydrodynamical model atmosphere. We put this into a wider context by investigating 3D abundance corrections for a set of G- and F-type dwarfs. Method: High-resolution, high signal-to-noise solar spectra were compared to line synthesis calculations performed on a solar CO5BOLD model. For the other atmospheres, we compared synthetic spectra of CO5BOLD 3D and associated 1D models. Results: For Hf we find a photospheric abundance A(Hf)=0.87+-0.04, in good agreement with a previous analysis, based on 1D model atmospheres. The weak Th ii 401.9 nm line constitutes the only Th abundance indicator available in the solar spectrum. It lies in the red wing of an Ni-Fe blend exhibiting a non-negligible convective asymmetry. Accounting for the asymmetry-related additional absorption, we obtain A(Th)=0.09+-0.03, consistent with the meteoritic abundance, and about 0.1 dex lower than obtained in previous photospheric abundance determinations. Conclusions: Only for the second time, to our knowledge, has am non-negligible effect of convective line asymmetries on an abundance derivation been highlighted. Three-dimensional hydrodynamical simulations should be employed to measure Th abundances in dwarfs if similar blending is present, as in the solar case. In contrast, 3D effects on Hf abundances are small in G- to mid F-type dwarfs and sub-giants, and 1D model atmospheres can be conveniently used.

Elisabetta Caffau; L. Sbordone; H. -G. Ludwig; P. Bonifacio; M. Steffen; N. T. Behara

2008-03-25T23:59:59.000Z

412

Natural gas monthly, April 1998  

SciTech Connect (OSTI)

This issue of the Natural Gas Monthly presents the most recent estimates of natural gas data from the Energy Information Administration (EIA). Estimates extend through April 1998 for many data series. The report highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, feature articles are presented designed to assist readers in using and interpreting natural gas information. This issue contains the special report, ``Natural Gas 1997: A Preliminary Summary.`` This report provides information on natural gas supply and disposition for the year 1997, based on monthly data through December from EIA surveys. 6 figs., 28 tabs.

NONE

1998-04-01T23:59:59.000Z

413

1999 Macmillan Magazines LtdNATURE |VOL 402 |18 NOVEMBER 1999 |www.nature.com 269 letters to nature  

E-Print Network [OSTI]

20771, USA ³ Atmospheric Ocean & Space Science, University of Michigan, Ann Arbor, Michigan 48109, USA .............................................................................................................................................. The four giant planets in the Solar System have abundances of `metals' (elements heavier than helium. This means that the abundances of those elements on the giant planets should be approximately solar. Here we

Atreya, Sushil

414

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

415

NLTE strontium abundance in a sample of extremely metal poor stars and the Sr/Ba ratio in the early Galaxy  

E-Print Network [OSTI]

Heavy element abundances in extremely metal-poor stars provide strong constraints on the processes of forming these elements in the first stars. We attempt to determine precise abundances of strontium in a homogeneous sample of extremely metal-poor stars. The abundances of strontium in 54 very or extremely metal-poor stars, was redetermined by abandoning the local thermodynamic equilibrium (LTE) hypothesis, and fitting non-LTE (NLTE) profiles to the observed spectral lines. The corrected Sr abundances and previously obtained NLTE Ba abundances are compared to the predictions of several hypothetical formation processes for the lighter neutron-capture elements. Our NLTE abundances confirm the previously determined huge scatter of the strontium abundance in low metallicity stars. This scatter is also found (and is even larger) at very low metallicities (i. e. early in the chemical evolution). The Sr abundance in the extremely metal-poor (EMP) stars is compatible with the main r-process involved in other processe...

Andrievsky, S M; Korotin, S A; Francois, P; Spite, M; Bonifacio, P; Cayrel, R; Hill, V

2011-01-01T23:59:59.000Z

416

ORIGIN OF THE UNUSUALLY LOW NITROGEN ABUNDANCES IN YOUNG POPULATIONS OF THE LARGE MAGELLANIC CLOUD  

SciTech Connect (OSTI)

It is a longstanding problem that H II regions and very young stellar populations in the Large Magellanic Cloud (LMC) have nitrogen abundances ([N/H]) that are a factor of {approx}7 lower than the solar value. We here discuss a new scenario in which the observed unusually low nitrogen abundances can be closely associated with recent collisions and subsequent accretion of H I high velocity clouds (HVCs) that surround the Galaxy and have low nitrogen abundances. We show that if the observed low [N/H] is limited to very young stars with ages less than {approx}10{sup 7} yr, then the collision/accretion rate of the HVCs onto the LMC needs to be {approx}0.2 M{sub sun} yr{sup -1} (corresponding to the total HVC mass of 10{sup 6}-10{sup 7} M{sub sun}) to dilute the original interstellar medium (ISM) before star formation. The required accretion rate means that even if the typical mass of HVCs accreted onto the LMC is {approx}10{sup 7} M{sub sun}, the Galaxy needs to have {approx}2500 massive HVCs within the LMC's orbital radius with respect to the Galactic center. The rather large number of required massive HVCs drives us to suggest that the HVCs are not likely to efficiently dilute the ISM of the LMC and consequently lower the [N/H]. We thus suggest the transfer of gas with low [N/H] from the Small Magellanic Cloud to the LMC as a promising scenario that can explain the observed low [N/H].

Bekki, Kenji [ICRAR, M468, University of Western Australia, 35 Stirling Highway, Crawley Western Australia 6009 (Australia); Tsujimoto, Takuji [National Astronomical Observatory, Mitaka-shi, Tokyo 181-8588 (Japan)

2010-10-01T23:59:59.000Z

417

Natural Gas Reforming | Department of Energy  

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

Hydrogen Production Natural Gas Reforming Natural Gas Reforming Photo of Petroleum Refinery Natural gas reforming is an advanced and mature production process that builds upon...

418

Natural Gas and Hydrogen Infrastructure Opportunities Workshop...  

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

Natural Gas and Hydrogen Infrastructure Opportunities Workshop Agenda Natural Gas and Hydrogen Infrastructure Opportunities Workshop Agenda Agenda for the Natural Gas and Hydrogen...

419

Report: Natural Gas Infrastructure Implications of Increased...  

Energy Savers [EERE]

interstate natural gas pipeline transmission system across a range of future natural gas demand scenarios that drive increased electric power sector natural gas use. To perform...

420

Solar abundances and helioseismology: fine structure spacings and separation ratios of low-degree p modes  

E-Print Network [OSTI]

We have used 4752 days of data collected by the Birmingham Solar-Oscillations Network (BiSON) to determine very precise oscillation frequencies of acoustic low-degree modes that probe the solar core. We compare the fine (small frequency) spacings and frequency separation ratios formed from these data with those of different solar models. We find that models constructed with low metallicity are incompatible with the observations. The results provide strong support for lowering the theoretical uncertainties on the neutrino fluxes. These uncertainties had recently been raised due to the controversy over the solar abundances.

Sarbani Basu; William J. Chaplin; Yvonne Elsworth; Roger New; Aldo M. Serenelli; Graham A. Verner

2006-10-02T23:59:59.000Z

Note: This page contains sample records for the topic "natural abundance half-life" 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

The distribution and abundance of the freshwater mussels (Bivalvia: Unionacea) of the Navasota River, Texas  

E-Print Network [OSTI]

blackish- brown and the nacre is white with an iridescent blue along the post- erior edge. Shell measurements and ratios of the specimens collected were: Length: 37-112 mm; x= 87 mm. Height: 29- 90 mm; x= 65 mm. Width: 17- 57 mm; x 45 mm. H/L: . 673...-. 875; x . 761. W/L: . 400-, 623; x= . 522. Remarks: A. Elicata was the most abundant species collected, making up 25. 9X of the total number of mussels collected. It was 21 Plate l. Amblema ~licata (Say). Length of the specimen shown: 79 mm. 23...

Littleton, Thomas Glynn

1979-01-01T23:59:59.000Z

422

Primordial Helium Abundance from CMB: a constraint from recent observations and a forecast  

E-Print Network [OSTI]

We studied a constraint on the primordial helium abundance Y_p from current and future observations of CMB. Using the currently available data from WMAP, ACBAR, CBI and BOOMERANG, we obtained the constraint as Y_p = 0.25^{+0.10}_{-0.07} at 68% C.L. We also provide a forecast for the Planck experiment using the Markov chain Monte Carlo approach. In addition to forecasting the constraint on Y_p, we investigate how assumptions for Y_p affect constraints on the other cosmological parameters.

Kazuhide Ichikawa; Toyokazu Sekiguchi; Tomo Takahashi

2008-08-18T23:59:59.000Z

423

Microbial abundance and biomass in sediments of the Texas-Louisiana shelf  

E-Print Network [OSTI]

MICROBIAL ABUNDANCF. AND BIOMASS IN SEDIMENTS OF THF. TEXAS-LOUISIANA SHELF A Thesis by MARTA ELIZABETH CRUZ-KAEGI Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfiument of the requirements for the degree... of MASTER OF SCIENCE December 1992 Major Subject: Oceanography MICROBIAL ABUNDANCE AND BIOMASS IN SEDIMENTS OF THE TEXAS-LOUISIANA SHELF A Thesis by MARTA ELIZABETH CRUZ-KAEGI Approved as to style and content by: I $7& Gilberl T. Rowe (Chair...

Cruz-Kaegi, Marta Elizabeth

1992-01-01T23:59:59.000Z

424

Seasonal Abundance and Dispersal of the Cotton Fleahopper as Related to Host Plant Phenology.  

E-Print Network [OSTI]

occurred. Croton served as a host plant both for overwintering eggs and throughout the growing season. Seasonal Abundance and Dispersal of the Cotton Fleahopper as Related to Host Plant Phenology *L. K. Almand W. L. Sterling C. L. Green... to various wind speeds also was de rmined in a wind tunnel with a testing area of about 3 lhic feet. Nymphs ;less than 24 hours old which had ltched from overwintering eggs (procedure developed I Sterling and Plapp, 1972) were collected for testing Id...

Almand, Lyndon K.; Sterling, W.L.; Green, C.L.

1976-01-01T23:59:59.000Z

425

The Role of Electroweak Corrections for the Dark Matter Relic Abundance  

SciTech Connect (OSTI)

We analyze the validity of the theorems concerning the cancellation of the infrared and collinar divergences in the case of dark matter freeze-out in the early universe. In particular, we compute the electroweak logarithmic corrections of infrared origin to the annihilation cross section of a dark matter particle being the neutral component of a SU(2){sub L} multiplet. The inclusion of processes with final state W can modify significantly the cross sections computed with only virtual W exchange. Our results show that the inclusion of infrared logs is necessary for a precise computation of the dark matter relic abundance.

Ciafaloni, Paolo [Dipartimento di Fisica, Università di Lecce and INFN - Sezione di Lecce, Via per Arnesano, I-73100 Lecce (Italy); Comelli, Denis [INFN - Sezione di Ferrara, Via Saragat 3, I-44100 Ferrara (Italy); Simone, Andrea De [CERN, PH-TH Division, CH-1211, Genève 23 (Switzerland); Morgante, Enrico; Riotto, Antonio [Département de Physique Théorique and Centre for Astroparticle Physics (CAP), 24 quai E. Ansermet, CH-1211 Genève (Switzerland); Urbano, Alfredo, E-mail: paolo.ciafaloni@le.infn.it, E-mail: comelli@fe.infn.it, E-mail: andrea.desimone@sissa.it, E-mail: enrico.morgante@unige.ch, E-mail: antonio.riotto@unige.ch, E-mail: alfredo.urbano@sissa.it [SISSA, Via Bonomea 265, I-34136 Trieste (Italy)

2013-10-01T23:59:59.000Z

426

A simple analytical model for the abundance of damped Ly-?absorbers  

E-Print Network [OSTI]

A simple analytical model for estimating the fraction (\\Omega_{gas}) of matter in gaseous form within the collapsed dark matter (DM) haloes is presented. The model is developed using (i) the Press-Schechter formalism to estimate the fraction of baryons in DM haloes, and (ii) the observational estimates of the star formation rate at different redshifts. The prediction for \\Omega_{gas} from the model is in broad agreement with the observed abundance of the damped Ly-\\alpha systems. Furthermore, it can be used for estimating the circular velocities of the collapsed haloes at different redshifts, which could be compared with future observations.

T. Roy Choudhury; T. Padmanabhan

2002-04-01T23:59:59.000Z

427

Super-Natural MSSM  

E-Print Network [OSTI]

We point out that the electroweak fine-tuning problem in the supersymmetric Standard Models (SSMs) is mainly due to the high energy definition of the fine-tuning measure. We propose super-natural supersymmetry which has an order one high energy fine-tuning measure automatically. The key point is that all the mass parameters in the SSMs arise from a single supersymmetry breaking parameter. In this paper, we show that there is no supersymmetry electroweak fine-tuning problem explicitly in the Minimal SSM (MSSM) with no-scale supergravity and Giudice-Masiero (GM) mechanism. We demonstrate that the $Z$-boson mass, the supersymmteric Higgs mixing parameter $\\mu$ at the unification scale, and the sparticle spectrum can be given as functions of the universal gaugino mass $M_{1/2}$. Because the light stau is the lightest supersymmetric particle (LSP) in the no-scale MSSM, to preserve $R$ parity, we introduce a non-thermally generated axino as the LSP dark matter candidate. We estimate the lifetime of the light stau b...

Du, Guangle; Nanopoulos, D V; Raza, Shabbar

2015-01-01T23:59:59.000Z

428

Nature of eclipsing pulsars  

E-Print Network [OSTI]

We present a model for pulsar radio eclipses in some binary systems, and test this model for PSRs B1957+20 and J2051-0827. We suggest that in these binaries the companion stars are degenerate dwarfs with strong surface magnetic fields. The magnetospheres of these stars are permanently infused by the relativistic particles of the pulsar wind. We argue that the radio waves emitted by the pulsar split into the eigenmodes of the electron-positron plasma as they enter the companion's magnetosphere and are then strongly damped due to cyclotron resonance with the ambient plasma particles. Our model explains in a natural way the anomalous duration and behavior of radio eclipses observed in such systems. In particular, it provides stable, continuous, and frequency-dependent eclipses, in agreement with the observations. We predict a significant variation of linear polarization both at eclipse ingress and egress. In this paper we also suggest several possible mechanisms of generation of the optical and $X$-ray emission ...

Khechinashvili, D; Gil, J; Khechinashvili, David; Melikidze, George; Gil, Janusz

2000-01-01T23:59:59.000Z

429

Nature of eclipsing pulsars  

E-Print Network [OSTI]

We present a model for pulsar radio eclipses in some binary systems, and test this model for PSRs B1957+20 and J2051-0827. We suggest that in these binaries the companion stars are degenerate dwarfs with strong surface magnetic fields. The magnetospheres of these stars are permanently infused by the relativistic particles of the pulsar wind. We argue that the radio waves emitted by the pulsar split into the eigenmodes of the electron-positron plasma as they enter the companion's magnetosphere and are then strongly damped due to cyclotron resonance with the ambient plasma particles. Our model explains in a natural way the anomalous duration and behavior of radio eclipses observed in such systems. In particular, it provides stable, continuous, and frequency-dependent eclipses, in agreement with the observations. We predict a significant variation of linear polarization both at eclipse ingress and egress. In this paper we also suggest several possible mechanisms of generation of the optical and $X$-ray emission observed from these binary systems.

David Khechinashvili; George Melikidze; Janusz Gil

2000-01-08T23:59:59.000Z

430

The effect of cattle grazing on the abundance and distribution of selected macroinvertebrates in west Galveston Island salt marshes  

E-Print Network [OSTI]

The effect of cattle grazing on the abundance and distribution of vegetation, burrowing crabs (Uca rapax, Uca pugnax, and Sesarma cinereum), marsh periwinkles (Littoraria irrorata), horn snails (Cerithidea pliculosa), and salt marsh snails (Melampus...

Martin, Jennifer Lynn

2004-09-30T23:59:59.000Z

431

Abundance of northern bobwhite and scaled quail in Texas: influence of weather and land-cover change  

E-Print Network [OSTI]

Despite intensive study, quail populations across the United States have declined since the 1960s. My analysis of a 21-year (1978-98) data set collected by the Texas Parks and Wildlife Department indicated abundance of northern bobwhite (Colinus...

Bridges, Andrew Scott

2012-06-07T23:59:59.000Z

432

Heat distribution by natural convection  

SciTech Connect (OSTI)

Natural convection can provide adequate heat distribution in many situations that arise in buildings. This is appropriate, for example, in passive solar buildings where some rooms tend to be more strongly solar heated than others. Natural convection can also be used to reduce the number of auxiliary heating units required in a building. Natural airflow and heat transport through doorways and other internal building apertures are predictable and can be accounted for in the design. The nature of natural convection is described, and a design chart is presented appropriate to a simple, single-doorway situation. Experimental results are summarized based on the monitoring of 15 passive solar buildings which employ a wide variety of geometrical configurations including natural convective loops.

Balcomb, J.D.

1985-01-01T23:59:59.000Z

433

Natural gas monthly, March 1998  

SciTech Connect (OSTI)

The March 1998 edition of the Natural Gas Monthly highlights activities, events, and analyses associated with the natural gas industry. Volume and price data are presented for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. This report also features an article on the correction of errors in the drilling activity estimates series, and in-depth drilling activity data. 6 figs., 28 tabs.

NONE

1998-03-01T23:59:59.000Z

434

Natural gas monthly, May 1995  

SciTech Connect (OSTI)

The NGM highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information.

NONE

1995-05-24T23:59:59.000Z

435

Natural gas monthly, September 1998  

SciTech Connect (OSTI)

The National Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. 6 figs., 27 tabs.

NONE

1998-09-01T23:59:59.000Z

436

The Effects of Site Characterization Activities on the Abundance of Ravens (Corvus corax) in the Yucca Mountain Area  

SciTech Connect (OSTI)

In response to the Nuclear Waste Policy Act of 1982 and the Nuclear Waste Policy Amendments Act of 1987, the U.S. Department of Energy (DOE) developed and is implementing the Yucca Mountain Site Characterization Project. Raven abundance was measured from August 1991 through August 1995 along treatment and control routes to evaluate whether site characterization activities resulted in increased raven abundance at Yucca Mountain. This study fulfills the requirement set forth in the incidental take provisions of the Biological Opinion that DOE monitor the abundance of ravens at Yucca Mountain. Ravens were more abundant at Yucca Mountain than in the control area, and raven abundance in both areas increased over time. However, the magnitude of differences between Yucca Mountain and control surveys did not change over time, indicating that the increase in raven abundance observed during this study was not related to site characterization activities. Increases over time on both Yucca Mountain and control routes are consistent with increases in raven abundance in the Mojave Desert reported by the annual Breeding Bird Survey of the US. Fish and Wildlife Service. Evidence from the Desert Tortoise Monitoring Program at Yucca Mountain suggests that ravens are not a significant predator of small tortoises in this locale. Carcasses of small tortoises (less than 110 mm in length) collected during the study showed little evidence of raven predation, and 59 radiomarked hatchlings that were monitored on a regular basis were not preyed upon by ravens. Overall, no direct evidence of raven predation on tortoises was observed during this study. Small tortoises are probably encountered so infrequently by ravens that they are rarely exploited as a food source. This is likely due to the relatively low abundance of both desert tortoises and ravens in the Yucca Mountain area.

P.E. Lederle

1998-05-08T23:59:59.000Z

437

,"New Mexico Natural Gas Prices"  

U.S. Energy Information Administration (EIA) Indexed Site

,"Worksheet Name","Description"," Of Series","Frequency","Latest Data for" ,"Data 1","New Mexico Natural Gas Prices",8,"Monthly","12015","1151989" ,"Release Date:","331...

438

,"New York Natural Gas Prices"  

U.S. Energy Information Administration (EIA) Indexed Site

Name","Description"," Of Series","Frequency","Latest Data for" ,"Data 1","New York Natural Gas Prices",8,"Monthly","102014","1151989" ,"Release Date:","12312014"...

439

on man, nature & air pollution  

E-Print Network [OSTI]

on man, nature & air pollution About three decades ago, itand episodes of air pollution the following summer. Wetthe increase in air pollution. This hypothesis generated

Finlayson-Pitts, Barbara J

2008-01-01T23:59:59.000Z

440

Natural Gas Pipeline Utilities (Maine)  

Broader source: Energy.gov [DOE]

These regulations apply to entities seeking to develop and operate natural gas pipelines and provide construction requirements for such pipelines. The regulations describe the authority of the...

Note: This page contains sample records for the topic "natural abundance half-life" 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

Natural gas ferries in Norway.  

E-Print Network [OSTI]

??This paper studies the emergence of natural gas powered ferries in Norway and their diffusion as a means to reaching the goals of reducing NOx… (more)

Myklebust, Benjamin

2006-01-01T23:59:59.000Z

442

Natural Gas Pipeline Safety (Kansas)  

Broader source: Energy.gov [DOE]

This article states minimum safety standards for the transportation of natural gas by pipeline and reporting requirements for operators of pipelines.

443

The Venezuelan natural gas industry  

SciTech Connect (OSTI)

Venezuela's consumption energy of comes from three primary sources: hydroelectricity, liquid hydrocarbons and natural gas. In 1986, the energy consumption in the internal market was 95.5 thousand cubic meters per day of oil equivalent, of which 32% was natural gas, 46% liquid hydrocarbons and 22% hydroelectricity. The Venezuelan energy policy established natural gas usage after hydroelectricity, as a substitute of liquid hydrocarbons, in order to increase exports of these. This policy permits a solid development of the natural gas industry, which is covered in this paper.

Silva, P.V.; Hernandez, N.

1988-01-01T23:59:59.000Z

444

Scientific and Natural Areas (Minnesota)  

Broader source: Energy.gov [DOE]

Certain scientific and natural areas are established throughout the state for the purpose of preservation and protection. Construction and new development is prohibited in these areas.

445

Natural gas monthly, August 1997  

SciTech Connect (OSTI)

This report presents information on natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported.

NONE

1997-08-01T23:59:59.000Z

446

Competitive Natural Gas Providers (Iowa)  

Broader source: Energy.gov [DOE]

Competitive providers and aggregators of natural gas must be certified by the Utilities Board. Applicants must demonstrate the managerial, technical, and financial capability to perform the...

447

Focussing the view on Nature's water-splitting catalyst  

SciTech Connect (OSTI)

About 3 billion years ago Nature invented a catalyst that splits water with highefficiency into molecular oxygen and hydrogen equivalents (protons and electrons). This reaction is energetically driven by sun light and the active centre contains relatively cheap and abundant metals: manganese and calcium. This biological system therefore forms the paradigm for all man made attempts for direct solar fuel production and several studies are underway to determine the electronic and geometric structures of this catalyst. In this report we briefly summarize the problems and the current status of these efforts, and propose a DFT-based strategy for obtaining a reliable high resolution structure of this unique catalyst that includes both the inorganic core and the first ligand sphere.

Messinger, Johannes; Yano, Junko

2008-01-01T23:59:59.000Z

448

Ozone Abundance in a Nitrogen-Carbon Dioxide Dominated Terrestrial Paleoatmosphere  

E-Print Network [OSTI]

We compute the ozone distribution for a model terrestrial paleoatmosphere in which the present oxygen abundance is largely replaced by carbon dioxide, which we argue is a reasonable working assumption. In principle, the presence of carbon dioxide might supplement the ozone shield as compared with models based on nitrogen without high carbon dioxide abundance so that early life need not have been as UV-resistant as often assumed. An extrasolar planet with a high-CO2 atmosphere might contain enough O3 to be a source of false positive biomarkers. We find that the globally averaged O3 column density can be the same, or nearly four times higher (depending upon the O2 partial pressure) when CO2 is used in place of N2 as the replacement component for lowered O2 in a 1-atm terrestrial planet with solar radiation. The effect is important for making quantitative deductions from future data, but does not invalidate the use of O3 as a biomarker for free oxygen. These results make prospects for detection of extrasolar planetary O3 absorption somewhat better than before.

B. C. Thomas; A. L. Melott; L. D. Martin; C. H. Jackman

2004-10-22T23:59:59.000Z

449

Ozone Abundance in a Nitrogen-Carbon Dioxide Dominated Terrestrial Paleoatmosphere  

E-Print Network [OSTI]

We compute the ozone distribution for a model terrestrial paleoatmosphere in which the present oxygen abundance is largely replaced by carbon dioxide, which we argue is a reasonable working assumption. In principle, the presence of carbon dioxide might supplement the ozone shield as compared with models based on nitrogen without high carbon dioxide abundance so that early life need not have been as UV-resistant as often assumed. An extrasolar planet with a high-CO2 atmosphere might contain enough O3 to be a source of false positive biomarkers. We find that the globally averaged O3 column density can be the same, or nearly four times higher (depending upon the O2 partial pressure) when CO2 is used in place of N2 as the replacement component for lowered O2 in a 1-atm terrestrial planet with solar radiation. The effect is important for making quantitative deductions from future data, but does not invalidate the use of O3 as a biomarker for free oxygen. These results make prospects for detection of extrasolar pla...

Thomas, B C; Martin, L D; Jackman, C H

2004-01-01T23:59:59.000Z

450

Solar models with accretion. I. Application to the solar abundance problem  

E-Print Network [OSTI]

We generate new standard solar models using newly analyzed nuclear fusion cross sections and present results for helioseismic quantities and solar neutrino fluxes. We discuss the status of the solar abundance problem and investigate whether nonstandard solar models with accretion from the protoplanetary disk might alleviate the problem. We examine a broad range of possibilities, analyzing both metal-enriched and metal-depleted accretion models and exploring three scenarios for the timing of the accretion. Only partial solutions are found: one can bring either the depth of the convective zone or the surface helium abundance into agreement with helioseismic results, but not both simultaneously. In addition, detailed results for solar neutrino fluxes show that neutrinos are a competitive source of information about the solar core and can help constrain possible accretion histories of the Sun. Finally, we briefly discuss how measurements of solar neutrinos from the CN-cycle could shed light on the interaction between the early Sun and its protoplanetary disk.

Aldo M. Serenelli; Wick C. Haxton; Carlos Pena-Garay

2011-04-08T23:59:59.000Z

451

THE FIRST FLUORINE ABUNDANCE DETERMINATIONS IN EXTRAGALACTIC ASYMPTOTIC GIANT BRANCH CARBON STARS  

SciTech Connect (OSTI)

Fluorine ({sup 19}F) abundances (or upper limits) are derived in six extragalactic asymptotic giant branch (AGB) carbon stars from the HF(1-0) R9 line at 2.3358 {mu}m in high-resolution spectra. The stars belong to the Local Group galaxies, Large Magellanic Cloud, Small Magellanic Cloud, and Carina dwarf spheroidal, spanning more than a factor of 50 in metallicity. This is the first study to probe the behavior of F with metallicity in intrinsic extragalactic C-rich AGB stars. Fluorine could be measured only in four of the target stars, showing a wide range in F enhancements. Our F abundance measurements together with those recently derived in Galactic AGB carbon stars show a correlation with the observed carbon and s-element enhancements. The observed correlations, however, display a different dependence on the stellar metallicity with respect to theoretical predictions in low-mass, low-metallicity AGB models. We briefly discuss the possible reasons for this discrepancy. If our findings are confirmed in a larger number of metal-poor AGBs, the issue of F production in AGB stars will need to be revisited.

Abia, C.; Cristallo, S.; Dominguez, I. [Dpto. Fisica Teorica y del Cosmos, Universidad de Granada, 18071 Granada (Spain); Cunha, K.; Smith, V. V. [National Optical Astronomy Observatory, P.O. Box 26732, Tucson, AZ 85726 (United States); De Laverny, P.; Recio-Blanco, A. [University of Nice-Sophia Antipolis, CNRS (UMR 6202), Cassiopee, Observatoire de la Cote d'Azur, B.P. 4229, 06304 Nice Cedex 4 (France); Straniero, O., E-mail: cabia@ugr.es [INAF-Osservatorio di Collurania, 64100 Teramo (Italy)

2011-08-10T23:59:59.000Z

452

What are little worlds made of? Stellar abundances and the building blocks of planets  

E-Print Network [OSTI]

If the photospheres of solar-type stars represent the composition of circumstellar disks from which any planets formed, spectroscopic determinations of stellar elemental abundances offer information on the composition of those planets, including smaller, rocky planets. In particular, the C/O ratio is proposed to be a key determinant of the composition of solids that condense from disk gas and are incorporated into planets. Also, planets may leave chemical signatures on the photospheres of their host stars by sequestering heavy elements, or by being accreted by the stars. The presence, absence, and composition of planets could be revealed by small differences in the relative abundances between stars. I critically examine these scenarios and show that (i) a model of Galactic chemical evolution predicts that the C/O ratio is expected to be close to the solar value and vary little between dwarf stars in the solar neighborhood; (ii) spectroscopic surveys of M dwarf stars limit the occurrence of stars with C/O $\\gt...

Gaidos, Eric

2015-01-01T23:59:59.000Z

453

Volatile abundances in submarine glasses from the North Fiji and Lau back-arc basins  

SciTech Connect (OSTI)

Glasses from submarine lavas of the North Fiji and lau back-arc basins were analyzed by high-temperature mass spectrometry for volatiles. Abundances for H{sub 2}O, Cl, F, S and CO{sub 2} in glasses ranging in composition from depleted, primitive MORB to enriched, transitional tholeiites are reported. The samples divide into three groups based on K{sub 2}O vs. H{sub 2}O, Ba/Zr vs. H{sub 2}O and K{sub 2}O/H{sub 2}O vs. P{sub 2}O{sub 5}/H{sub 2}O variation diagrams. At similar Mg No., the least evolved samples studied are nearly identical to N-type MORB in H{sub 2}O abundances but show Cl contents enriched by a factor of 5. More enriched samples, classified as back-arc basin basalts (BABB) on the basis of major/trace elements and isotopes, are not as hydrous (at similar Mg No.) as those from the Mariana and East Scotia Sea back-arc basins. The data indicate that not all back-arc basins erupt lavas with the distinct volatile and other elemental characteristics of lavas from the Mariana Trough and Scotia Sea.

Aggrey, K.E.; Muenow, D.W.; Sinton, J.M. (Univ. of Hawaii, Honolulu (USA))

1988-10-01T23:59:59.000Z

454

Magneto-convective models of red dwarfs: constraints imposed by the lithium abundance  

E-Print Network [OSTI]

Magnetic fields impede the onset of convection, thereby altering the thermal structure of a convective envelope in a low mass star: this has an effect on the amount of lithium depletion in a magnetized star. In order to quantify this effect, we have applied a magneto-convective model to two low mass stars for which lithium abundances and precise structural parameters are known: YY Gem and CU Cnc. For both stars, we have obtained models which satisfy empirical constraints on the following parameters: R, L, surface magnetic field strength, and Li abundance. In the case of YY Gem, we have obtained a model which satisfies the empirical constraints with an internal magnetic field of several megagauss: such a field strength is within the range of a dynamo where the field energy is in equipartition with rotational energy deep inside the convection zone. However, in the case of CU Cnc, the Li requires an internal magnetic field which is probably too strong for a dynamo origin: we suggest possible alternatives which m...

MacDonald, J

2015-01-01T23:59:59.000Z

455

Permitted Oxygen Abundances and the Temperature Scale of Metal-Poor Turn-Off Stars  

E-Print Network [OSTI]

We use high quality VLT/UVES published data of the permitted OI triplet and FeII lines to determine oxygen and iron abundances in unevolved (dwarfs, turn-off, subgiants) metal-poor halo stars. The calculations have been performed both in LTE and NLTE, employing effective temperatures obtained with the new infrared flux method (IRFM) temperature scale by Ramirez & Melendez, and surface gravities from Hipparcos parallaxes and theoretical isochrones. A new list of accurate transition probabilities for FeII lines, tied to the absolute scale defined by laboratory measurements, has been used. We find a plateau in the oxygen-to-iron ratio over more than two orders of magnitude in iron abundance (-3.2 < [Fe/H] < -0.7), with a mean [O/Fe] = 0.5 dex (sigma = 0.1 dex), independent of metallicity, temperature and surface gravity. According to the new IRFM Teff scale, the temperatures of turn-off halo stars strongly depend on metallicity, a result that is in excellent qualitative and quantitative agreement with stellar evolution calculations, which predict that the Teff of the turn-off at [Fe/H] = -3 is about 600-700 K higher than that at [Fe/H] = -1.

J. Melendez; N. G. Shchukina; I. E. Vasiljeva; I. Ramirez

2006-01-12T23:59:59.000Z

456

ISO spectroscopy of compact HII regions in the Galaxy. II Ionization and elemental abundances  

E-Print Network [OSTI]

Based on the ISO spectral catalogue of compact HII regions by Peeters et al. (2001), we present a first analysis of the hydrogen recombination and atomic fine-structure lines originated in the ionized gas. The sample consists of 34 HII regions located at galactocentric distances between Rgal = 0 and 15 kpc. The SWS HI recombination lines between 2 and 8 mum are used to estimate the extinction law at these wavelengths for 14 HII regions. An extinction in the K band between 0 and $\\sim$ 3 mag. has been derived. The fine-structure lines of N, O, Ne, S and Ar are detected in most of the sources. Most of these elements are observed in two different ionization stages probing a range in ionization potential up to 41 eV. The ISO data, by itself or combined with radio data taken from the literature, is used to derive the elemental abundances relative to hydrogen. The present data thus allow us to describe for each source its elemental abundance, its state of ionization and to constrain the properties of the ionizing star(s).

N. L. Martin-Hernandez; E. Peeters; C. Morisset; A. G. G. M. Tielens; P. Cox; P. R. Roelfsema; J. -P. Baluteau; D. Schaerer; J. S. Mathis; F. Damour; E. Churchwell; M. F. Kessler

2001-10-30T23:59:59.000Z

457

History of Milky Way Dwarf Spheroidal Galaxies Imprinted on Abundance Patterns of Neutron-Capture Elements  

E-Print Network [OSTI]

Stellar abundance pattern of neutron-capture elements such as barium is used as a powerful tool to infer how star formation proceeded in dwarf spheroidal (dSph) galaxies. It is found that the abundance correlation of barium with iron in stars belonging to dSph galaxies orbiting the Milky Way, i.e., Draco, Sextans, and Ursa Minor have a feature similar to the barium-iron correlation in Galactic metal-poor stars. The common feature of these two correlations can be realized by our inhomogeneous chemical evolution model based on the supernova-driven star formation scenario if dSph stars formed from gas with a velocity dispersion of ~26 km/s. This velocity dispersion together with the stellar luminosities strongly suggest that dark matter dominated dSph galaxies. The tidal force of the Milky Way links this velocity dispersion with the currently observed value <10 km/s by stripping the dark matter in dSph galaxies. As a result, the total mass of each dSph galaxy is found to have been originally ~25 times larger than at present. Our inhomogeneous chemical evolution model succeeds in reproducing the stellar [Fe/H] distribution function observed in Sextans. In this model, supernovae immediately after the end of the star formation epoch can expel the remaining gas over the gravitational potential of the dSph galaxy.

Takuji Tsujimoto; Toshikazu Shigeyama

2002-05-02T23:59:59.000Z

458

NATURAL GAS STORAGE ENGINEERING Kashy Aminian  

E-Print Network [OSTI]

NATURAL GAS STORAGE ENGINEERING Kashy Aminian Petroleum & Natural Gas Engineering, West Virginia University, Morgantown, WV, USA. Shahab D. Mohaghegh Petroleum & Natural Gas Engineering, West Virginia University, Morgantown, WV, USA. Keywords: Gas Storage, Natural Gas, Storage, Deliverability, Inventory

Mohaghegh, Shahab

459

Montana Natural Areas Act of 1974 (Montana)  

Broader source: Energy.gov [DOE]

The Montana Natural Areas Act of 1974 provides for the designation and establishment of a system of natural areas in order to preserve the natural ecosystems of these areas. Designated natural...

460

Interdependence of Electricity System Infrastructure and Natural...  

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

Interdependence of Electricity System Infrastructure and Natural Gas Infrastructure - EAC 2011 Interdependence of Electricity System Infrastructure and Natural Gas Infrastructure -...

Note: This page contains sample records for the topic "natural abundance half-life" 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

Nature Macmillan Publishers Ltd 1997 13. Vidal-Madjar, A., Ferlet, R. & Lemoine, M. Deuterium abundance and cosmology. Preprint astro-ph/  

E-Print Network [OSTI]

, P. T. P., Liddle, A. R. & Scott, D. Cold dark matter models with high baryon content. Mon. Not. R. Here we report experimen- tal observations of the dynamics of disks falling in water/glycerol mixtures t ¼ 0:076­1:63 mm were dropped in water and water/gly- cerol mixtures from heights ranging from 0.3 to 1

Nori, Franco

462

Natural gas monthly, July 1990  

SciTech Connect (OSTI)

This report highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. A glossary is included. 7 figs., 33 tabs.

Not Available

1990-10-03T23:59:59.000Z

463

Introduction The Nature of Design  

E-Print Network [OSTI]

Introduction The Nature of Design The Concept of Entropy in MTC Design Complexity Conclusions The Role of Entropy in Design Theory and Methodology Waseem A. Khan Jorge Angeles Centre for Intelligent. Entropy in Design 1 #12;Introduction The Nature of Design The Concept of Entropy in MTC Design Complexity

Berlin,Technische Universität

464

Curriculum in Renewable Natural Resources  

E-Print Network [OSTI]

Curriculum in Renewable Natural Resources Catalog 12-13 University Core Curriculum Required Courses............................................................................... (0-2) 1 43 Renewable Natural Resources Core Courses RENR 205 Fundamentals of Ecology............................................................ (3-0) 3 ESSM 351 Geographic Information Systems and Resource Management........................ (2

465

Natural gas monthly, August 1990  

SciTech Connect (OSTI)

This report highlights activities, events, and analyses of interest to public and private sector oganizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. 33 tabs.

Not Available

1990-11-05T23:59:59.000Z

466

,"New York Natural Gas Summary"  

U.S. Energy Information Administration (EIA) Indexed Site

50NY3","N3010NY3","N3020NY3","N3035NY3","N3045NY3" "Date","Natural Gas Citygate Price in New York (Dollars per Thousand Cubic Feet)","New York Price of Natural Gas Delivered to...

467

NATIONAL MUSEUM OF NATURAL HISTORY  

E-Print Network [OSTI]

NATIONAL MUSEUM OF NATURAL HISTORY MUSEUM REPORT 2009 ­ 2010 @ 100 | PAST, PRESENT & FUTURE #12;NatioNal MuseuM of NatUral History @ 100 | Past, PreseNt & future on March 17, 1910, our doors opened of amazing advances, and the Museum's accomplishments have been no less significant. in our first century, we

Mathis, Wayne N.

468

Natural gas monthly, October 1991  

SciTech Connect (OSTI)

The Natural Gas Monthly (NGM) is prepared in the Data Operations Branch of the Reserves and Natural Gas Division, Office of Oil and Gas, Energy Information Administration (EIA), US Department of Energy (DOE). The NGM highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. The data in this publication are collected on surveys conducted by the EIA to fulfill its responsibilities for gathering and reporting energy data. Some of the data are collected under the authority of the Federal Energy Regulatory Commission (FERC), an independent commission within the DOE, which has jurisdiction primarily in the regulation of electric utilities and the interstate natural gas industry. Geographic coverage is the 50 States and the District of Columbia. 16 figs., 33 tabs.

Not Available

1991-11-05T23:59:59.000Z

469

Natural gas pipeline technology overview.  

SciTech Connect (OSTI)

The United States relies on natural gas for one-quarter of its energy needs. In 2001 alone, the nation consumed 21.5 trillion cubic feet of natural gas. A large portion of natural gas pipeline capacity within the United States is directed from major production areas in Texas and Louisiana, Wyoming, and other states to markets in the western, eastern, and midwestern regions of the country. In the past 10 years, increasing levels of gas from Canada have also been brought into these markets (EIA 2007). The United States has several major natural gas production basins and an extensive natural gas pipeline network, with almost 95% of U.S. natural gas imports coming from Canada. At present, the gas pipeline infrastructure is more developed between Canada and the United States than between Mexico and the United States. Gas flows from Canada to the United States through several major pipelines feeding U.S. markets in the Midwest, Northeast, Pacific Northwest, and California. Some key examples are the Alliance Pipeline, the Northern Border Pipeline, the Maritimes & Northeast Pipeline, the TransCanada Pipeline System, and Westcoast Energy pipelines. Major connections join Texas and northeastern Mexico, with additional connections to Arizona and between California and Baja California, Mexico (INGAA 2007). Of the natural gas consumed in the United States, 85% is produced domestically. Figure 1.1-1 shows the complex North American natural gas network. The pipeline transmission system--the 'interstate highway' for natural gas--consists of 180,000 miles of high-strength steel pipe varying in diameter, normally between 30 and 36 inches in diameter. The primary function of the transmission pipeline company is to move huge amounts of natural gas thousands of miles from producing regions to local natural gas utility delivery points. These delivery points, called 'city gate stations', are usually owned by distribution companies, although some are owned by transmission companies. Compressor stations at required distances boost the pressure that is lost through friction as the gas moves through the steel pipes (EPA 2000). The natural gas system is generally described in terms of production, processing and purification, transmission and storage, and distribution (NaturalGas.org 2004b). Figure 1.1-2 shows a schematic of the system through transmission. This report focuses on the transmission pipeline, compressor stations, and city gates.

Folga, S. M.; Decision and Information Sciences

2007-11-01T23:59:59.000Z

470

Exploring the Potential Business Case for Synergies Between Natural Gas and Renewable Energy  

SciTech Connect (OSTI)

Natural gas and renewable energy each contribute to economic growth, energy independence, and carbon mitigation, sometimes independently and sometimes collectively. Often, natural gas and renewables are considered competitors in markets, such as those for bulk electricity. This paper attempts to address the question, 'Given near- and long-term needs for abundant, cleaner energy sources and decarbonization, how can more compelling business models be created so that these two domestic forms of energy work in greater concert?' This paper explores revenue opportunities that emerge from systems-level perspectives in 'bulk energy' (large-scale electricity and natural gas production, transmission, and trade) and four 'distribution edge' subsectors: industrial, residential, commercial, and transportation end uses.

Cochran, J.; Zinaman, O.; Logan, J.; Arent, D.

2014-02-01T23:59:59.000Z

471

Exploration of synchrotron Mossbauer micrscopy with micrometer resolution: forward and a new backscattering modality on natural samples  

SciTech Connect (OSTI)

New aspects of synchrotron Moessbauer microscopy are presented. A 5 {micro}m spatial resolution is achieved, and sub-micrometer resolution is envisioned. Two distinct and unique methods, synchrotron Moessbauer imaging and nuclear resonant incoherent X-ray imaging, are used to resolve spatial distribution of species that are chemically and magnetically distinct from one another. Proof-of-principle experiments were performed on enriched {sup 57}Fe phantoms, and on samples with natural isotopic abundance, such as meteorites.

Yan, L.; Zhao, J.; Toellner, T.S.; Divan, R.; Xu, S.; Cai, Z.; Boesenberg, J.S.; Freidrich, J.M.; Cramer, S.P.; Alp, E.E. (Biosciences Division); ( CNM); ( XSD); (Univ. of California, Davis); (American Museum of Natural History); (Brown Univ.); (Fordham Univ.)

2012-01-01T23:59:59.000Z

472

Natural gas monthly, February 1998  

SciTech Connect (OSTI)

This issue of the Natural Gas Monthly (NGM) presents the most recent estimates of natural gas data from the Energy Information Administration. Estimates extend through February 1998 for many data series, and through November 1997 for most natural gas prices. Highlights of the natural gas data contained in this issue are: Preliminary estimates for January and February 1998 show that dry natural gas production, net imports, and consumption are all within 1 percent of their levels in 1997. Warmer-than-normal weather in recent months has resulted in lower consumption of natural gas by the residential sector and lower net withdrawals of gas from under round storage facilities compared with a year ago. This has resulted in an estimate of the amount of working gas in storage at the end of February 1998 that is 18 percent higher than in February 1997. The national average natural gas wellhead price is estimated to be $3.05 per thousand cubic feet in November 1997, 7 percent higher than in October. The cumulative average wellhead price for January through November 1997 is estimated to be $2.42 per thousand cubic feet, 17 percent above that of the same period in 1996. This price increase is far less than 36-percent rise that occurred between 1995 and 1996. 6 figs., 26 tabs.

NONE

1998-02-01T23:59:59.000Z

473

Abundance ratios of volatile vs. refractory elements in planet-harbouring stars: hints of pollution?  

E-Print Network [OSTI]

We present the [X/H] trends as function of the elemental condensation temperature Tc in 88 planet host stars and in a volume-limited comparison sample of 33 dwarfs without detected planetary companions. We gathered homogeneous abundance results for many volatile and refractory elements spanning a wide range of Tc, from a few dozens to several hundreds kelvin. We investigate possible anomalous trends of planet hosts with respect to comparison sample stars in order to detect evidence of possible pollution events. No significant differences are found in the behaviour of stars with and without planets. This result is in agreement with a ``primordial'' origin of the metal excess in planet host stars. However, a subgroup of 5 planet host and 1 comparison sample stars stands out for having particularly high [X/H] vs. Tc slopes.

A. Ecuvillon; G. Israelian; N. C. Santos; M. Mayor; G. Gilli

2005-12-08T23:59:59.000Z

474

{beta}-delayed neutron emission measurements around the third r-process abundance peak  

SciTech Connect (OSTI)

This contribution summarizes an experiment performed at GSI (Germany) in the neutron-rich region beyond N=126. The aim of this measurement is to provide the nuclear physics input of relevance for r-process model calculations, aiming at a better understanding of the third r-process abundance peak. Many exotic nuclei were measured around {sup 211}Hg and {sup 215}Tl. Final ion identification diagrams are given in this contribution. For most of them, we expect to derive halflives and and {beta}-delayed neutron emission probabilities. The detectors used in this experiment were the Silicon IMplantation and Beta Absorber (SIMBA) detector, based on an array of highly segmented silicon detectors, and the BEta deLayEd Neutron (BELEN) detector, which consisted of 30 3He counters embedded in a polyethylene matrix.

Caballero-Folch, R.; Cortes, G.; Calvino, F.; Gomez-Hornillos, M. B.; Riego, A. [INTE-DFEN, Universitat Politecnica de Catalunya, Barcelona (Spain); Domingo-Pardo, C.; Tain, J. L.; Agramunt, J.; Rubio, B. [IFIC, CSIC-University of Valencia, Valencia (Spain); Algora, A. [IFIC, CSIC-University of Valencia, Valencia (Spain) and Inst. Nucl. Research, Debrecen (Hungary); Ameil, F.; Farinon, F.; Heil, M.; Knoebel, R.; Kojouharov, I.; Kurcewicz, J.; Kurz, N.; Litvinov, Y.; Mukha, I.; Nociforo, C. [GSI, Darmstadt (Germany); and others

2013-06-10T23:59:59.000Z

475

In-pile measurements of the decay constants and relative abundances of delayed neutrons  

SciTech Connect (OSTI)

An in-pile experimental technique to measure the decay constants and the relative abundances of the delayed neutron groups applicable for a given reactor system is presented. The method is based on a least-squares-fitting technique that simultaneously fits a series of transients produced by small reactivity perturbations to a reactor operating initially at delayed critical. The function that is least-squares fit is the analytic solution (written in terms of an arbitrary number of delayed neutron groups) as obtained by the point reactor model for the reactor response following a step change in reactivity. The application of the method does not require any knowledge of the size of the reactivity perturbations, and the method is independent of the detector efficiency. The results are based solely on the measurable quantities of relative power, time, and one measurable root of the Inhour equation.

Spriggs, G.D. (Los Alamos National Lab., NM (United States))

1993-08-01T23:59:59.000Z

476

The surface carbon and nitrogen abundances in models of ultra metal-poor stars  

E-Print Network [OSTI]

We investigate whether the observed high number of carbon- and nitrogen-enhanced extremely metal-poor stars could be explained by peculiar evolutionary properties during the core He flash at the tip of the red giant branch. For this purpose we compute a series of detailed stellar models expanding upon our previous work; in particular, we investigate if during the major He flash the penetration of the helium convective zone into the overlying hydrogen-rich layers can produce carbon- and nitrogen-rich abundances in agreement with current spectroscopic observations. The dependence of this phenomenon on selected model input parameters, such as initial metallicity and treatment of convection is examined in detail.

H. Schlattl; M. Salaris; S. Cassisi; A. Weiss

2002-05-20T23:59:59.000Z

477

Transport Phenomena and Light Element Abundances in the Sun and Solar Type Stars  

E-Print Network [OSTI]

The observations of light elements in the Sun and Solar type stars give special clues for understanding the hydrodynamical processes at work in stellar interiors. In the Sun 7Li is depleted by 140 while 3He has not increased by more than 10% in 3 Gyrs. Meanwhile the inversion of helioseismic modes lead to a precision on the sound velocity of about .1%. The mixing processes below the solar convection zone are constrained by these observations. Lithium is depleted in most Pop I solar type stars. In halo stars however, the lithium abundance seems constant in the "spite plateau" with no observed dispersion, which is difficult to reconcile with the theory of diffusion processes. In the present paper, the various relevant observations will be discussed. It will be shown that the mu-gradients induced by element settling may help solving the "lithium paradox".

Sylvie Vauclair

2000-02-17T23:59:59.000Z

478

Lithium abundance/surface activity connections in solar-type Pleiads  

E-Print Network [OSTI]

The relation between the lithium abundance, A_Li, and photospheric activity of solar-type Pleiads is investigated for the first time via acquisition and analysis of B and V-band data. Predictions of activity levels of target stars were made according to the A_Li/(B-V) relation and then compared with new CCD photometric measurements. Six sources behaved according to the predictions while one star (HII 676), with low predicted activity, exhibited the largest variability of the study; another star (HII 3197), with high predicted activity, was surprisingly quiet. Two stars displayed non-periodic fadings, this being symptomatic of orbiting disk-like structures with irregular density distributions. Although the observation windows were not ideal for rotational period detection, some periodograms provided possible values; the light-curve obtained for HII 1532 is consistent with that previously recorded.

D. Clarke; E. C. MacDonald; S. Owens

2003-12-03T23:59:59.000Z

479

Oxygen abundances in the Galactic Bulge: evidence for fast chemical enrichment  

E-Print Network [OSTI]

AIMS: We spectroscopically characterize the Galactic Bulge to infer its star formation timescale, compared to the other Galactic components, through the chemical signature on its individual stars. METHODS: We derived iron and oxygen abundances for 50 K giants in four fields towards the Galactic bulge. High resolution (R=45,000) spectra for the target stars were collected with FLAMES-UVES at the VLT. RESULTS: Oxygen, as measured from the forbidden line at 6300 \\AA, shows a well-defined trend with [Fe/H], with [O/Fe] higher in bulge stars than in thick disk ones, which were known to be more oxygen enhanced than thin disk stars. CONCLUSIONS: These results support a scenario in which the bulge formed before and more rapidly than the disk, and therefore the MW bulge can be regarded as a prototypical old spheroid, with a formation history similar to that of early-type (elliptical) galaxies.

M. Zoccali; A. Lecureur; B. Barbuy; V. Hill; A. Renzini; D. Minniti; Y. Momany; A. Gomez; S. Ortolani

2006-09-01T23:59:59.000Z

480

Abundances in Planetary Nebulae An Autopsy of Low and Intermediate Mass Stars  

E-Print Network [OSTI]

In this work I report on the results of synthetic thermally pulsing asymptotic giant branch models (TP-AGB) and compare the results to the abundance ratios in a sample of planetary nebulae. I use updated input parameters for mass-loss, the stellar luminosity, and dredge-up. I calculated models with masses between 0.8 solar masses and 8.0 solar masses. I also calculated models with [Fe/H] between -2.5 and 0.3. The effects of the first, second, third dredge-ups and hot-bottom burning are reported on. Models of the planetary nebula in M15 are reported on. The analysis of samples of Galactic bulge and disk nebulae are also reported.

James F. Buell

2004-03-12T23:59:59.000Z

Note: This page contains sample records for the topic "natural abundance half-life" 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.


481

Abundances of presolar graphite and SiC from supernovae and AGB stars in the Murchison meteorite  

SciTech Connect (OSTI)

Pesolar graphite grains exhibit a range of densities (1.65 – 2.20 g/cm{sup 3}). We investigated abundances of presolar graphite grains formed in supernovae and in asymptotic giant branch (AGB) stars in the four density fractions KE3, KFA1, KFB1 and KFC1 extracted from the Murchison meteorite to probe dust productions in these stellar sources. Seventy-six and 50% of the grains in the low-density fractions KE3 and KFA1, respectively, are supernova grains, while only 7.2% and 0.9% of the grains in the high-density fractions KFB1 and KFC1 have a supernova origin. Grains of AGB star origin are concentrated in the high-density fractions KFB1 and KFC1. From the C isotopic distributions of these fractions and the presence of s-process Kr with {sup 86}Kr/{sup 82}Kr?=?4.43±0.46 in KFC1, we estimate that 76% and 80% of the grains in KFB1 and KFC1, respectively, formed in AGB stars. From the abundance of graphite grains in the Murchison meteorite, 0.88 ppm, the abundances of graphite from supernovae and AGB stars are 0.24 ppm and 0.44 ppm, respectively: the abundances of graphite in supernovae and AGB stars are comparable. In contrast, it has been known that 1% of SiC grains formed in supernovae and 95% formed in AGB stars in meteorites. Since the abundance of SiC grains is 5.85 ppm in the Murchison meteorite, the abundances of SiC from supernovae and AGB stars are 0.063 ppm and 5.6 ppm, respectively: the dominant source of SiC grains is AGB stars. Since SiC grains are harder and likely to survive better in space than graphite grains, the abundance of supernova graphite grains, which is higher than that of supernova SiC grains, indicates that supernovae proficiently produce graphite grains. Graphite grains from AGB stars are, in contrast, less abundant that SiC grains from AGB stars (0.44 ppm vs. 5.6 ppm). It is difficult to derive firm conclusions for graphite and SiC formation in AGB stars due to the difference in susceptibility to grain destruction. Metallicity of the parent AGB stars of graphite grains is much lower than that of SiC grains and the difference in metallicity might also have affected to the difference in the abundances in the Murchison meteorite.

Amari, Sachiko; Zinner, Ernst [McDonnell Center for the Space Sciences and the Physics Department, Washington University, One Brookings Dr., St. Louis, MO 63130 (United States); Gallino, Roberto [Dipartimento di Fisica, Università di Torino, Via P. Giuria 1, I-10125 Torino (Italy)

2014-05-02T23:59:59.000Z

482

RUBIDIUM ABUNDANCES IN THE GLOBULAR CLUSTERS NGC 6752, NGC 1904, AND NGC 104 (47 Tuc)  

SciTech Connect (OSTI)

Large star-to-star variations of the abundances of proton-capture elements, such as Na and O, in globular clusters (GCs) are interpreted as the effect of internal pollution resulting from the presence of multiple stellar populations. To better constrain this scenario, we investigate the abundance distribution of the heavy element rubidium (Rb) in NGC 6752, NGC 1904, and NGC 104 (47 Tuc). Combining the results from our sample with those in the literature, we found that Rb exhibits no star-to-star variations, regardless of cluster metallicity, with the possible intriguing, although very uncertain, exception of the metal-rich bulge cluster NGC 6388. If no star-to-star variations can be confirmed for all GCs, this finding implies that the stellar source of the proton-capture element variations must not have produced significant amounts of Rb. This element is observed to be enhanced at extremely high levels in intermediate-mass asymptotic giant branch (IM-AGB) stars in the Magellanic Clouds (i.e., at a metallicity similar to 47 Tuc and NGC 6388). This fact may present a challenge to this popular candidate polluter, unless the mass range of the observed IM-AGB stars does not participate in the formation of the second-generation stars in GCs. A number of possible solutions are available to resolve this conundrum, including the fact that the Magellanic Cloud observations are very uncertain and may need to be revised. The fast rotating massive stars scenario would not face this potential problem as the slow mechanical winds of these stars during their main-sequence phase do not carry any Rb enhancements; however, these candidates face even bigger issues such as the production of Li and the close overlap with core-collapse supernova timescales. Observations of Sr, Rb, and Zr in metal-rich clusters such as NGC 6388 and NGC 6441 are sorely needed to clarify the situation.

D'Orazi, Valentina [Department of Physics and Astronomy, Macquarie University, Balaclava Road, North Ryde, NSW 2109 (Australia); Lugaro, Maria; Campbell, Simon W. [Monash Centre for Astrophysics, School of Mathematical Sciences, Monash University, Building 28, Clayton, VIC 3800 (Australia); Bragaglia, Angela; Carretta, Eugenio [INAF Osservatorio Astronomico di Bologna, via Ranzani 1, I-40127 Bologna (Italy); Gratton, Raffaele G.; Lucatello, Sara [INAF Osservatorio Astronomico di Padova, vicolo dell'Osservatorio 5, I-35122 Padova (Italy); D'Antona, Francesca, E-mail: valentina.dorazi@mq.edu.au [INAF Osservatorio Astronomico di Roma, via Frascati 33, I-00040 Monteporzio (Italy)

2013-10-10T23:59:59.000Z

483

SOLAR MODELS WITH ACCRETION. I. APPLICATION TO THE SOLAR ABUNDANCE PROBLEM  

SciTech Connect (OSTI)

We generate new standard solar models using newly analyzed nuclear fusion cross sections and present results for helioseismic quantities and solar neutrino fluxes. The status of the solar abundance problem is discussed. We investigate whether nonstandard solar models with accretion from the protoplanetary disk might alleviate this problem. We examine a broad range of models, analyzing metal-enriched and metal-depleted accretion and three scenarios for the timing of accretion. Only partial solutions are found. For metal-rich accreted material (Z{sub ac} {approx}> 0.018) there exist combinations of accreted mass and metallicity that bring the depth of the convective zone into agreement with the helioseismic value. For the surface helium abundance, the helioseismic value is reproduced if metal-poor or metal-free accretion is assumed (Z{sub ac} {approx}< 0.09). In both cases a few percent of the solar mass must be accreted. Precise values depend on when accretion takes place. We do not find a simultaneous solution to both problems but speculate that changing the hydrogen-to-helium mass ratio in the accreted material may lead to more satisfactory solutions. We also show that, with current data, solar neutrinos are already a very competitive source of information about the solar core and can help constraining possible accretion histories. Even without helioseismic constraints, solar neutrinos rule out the possibility that more than 0.02 M{sub Sun} from the protoplanetary disk were accreted after the Sun settled on the main sequence. Finally, we discuss how measurements of neutrinos from the CN cycle could shed light on the interaction between the early Sun and its protoplanetary disk.

Serenelli, Aldo M. [Instituto de Ciencias del Espacio (CSIC-IEEC), Facultad de Ciencias, Campus UAB, 08193 Bellaterra (Spain); Haxton, W. C. [Department of Physics, MC 7300, University of California, Berkeley, CA 94720-7300 (United States); Pena-Garay, Carlos [Instituto de Fisica Corpuscular (CSIC-UVEG), Aptdo. 22085, E-46071 Valencia (Spain)

2011-12-10T23:59:59.000Z

484

ABUNDANCE OF {sup 26}Al AND {sup 60}Fe IN EVOLVING GIANT MOLECULAR CLOUDS  

SciTech Connect (OSTI)

The nucleosynthesis and ejection of radioactive {sup 26}Al (t{sub 1/2} {approx} 0.72 Myr) and {sup 60}Fe, (t{sub 1/2} {approx} 2.5 Myr) into the interstellar medium is dominated by the stellar winds of massive stars and supernova type II explosions. Studies of meteorites and their components indicate that the initial abundances of these short-lived radionuclides in the solar protoplanetary disk were higher than the background levels of the galaxy inferred from {gamma}-ray astronomy and models of the galactic chemical evolution. This observation has been used to argue for a late-stage addition of stellar debris to the solar system's parental molecular cloud or, alternatively, the solar protoplanetary disk, thereby requiring a special scenario for the formation of our solar system. Here, we use supercomputers to model-from first principles-the production, transport, and admixing of freshly synthesized {sup 26}Al and {sup 60}Fe in star-forming regions within giant molecular clouds. Under typical star formation conditions, the levels of {sup 26}Al in most star-forming regions are comparable to that deduced from meteorites, suggesting that the presence of short-lived radionuclides in the early solar system is a generic feature of the chemical evolution of giant molecular clouds. The {sup 60}Fe/{sup 26}Al yield ratio of Almost-Equal-To 0.2 calculated from our simulations is consistent with the galactic value of 0.15 {+-} 0.06 inferred from {gamma}-ray astronomy but is significantly higher than most current solar system measurements indicate. We suggest that estimates based on differentiated meteorites and some chondritic components may not be representative of the initial {sup 60}Fe abundance of the bulk solar system.

Vasileiadis, Aristodimos; Nordlund, Ake; Bizzarro, Martin [Centre for Star and Planet Formation, Natural History Museum of Denmark, University of Copenhagen, Ostervoldgade 5-7, DK-1350 Copenhagen O (Denmark)

2013-05-20T23:59:59.000Z

485

Natural Product Xn on matrices  

E-Print Network [OSTI]

This book has eight chapters. The first chapter is introductory in nature. Polynomials with matrix coefficients are introduced in chapter two. Algebraic structures on these polynomials with matrix coefficients is defined and described in chapter three. Chapter four introduces natural product on matrices. Natural product on super matrices is introduced in chapter five. Super matrix linear algebra is introduced in chapter six. Chapter seven claims only after this notion becomes popular we can find interesting applications of them. The final chapter suggests over 100 problems some of which are at research level.

W. B. Vasantha Kandasamy; Florentin Smarandache

2012-02-20T23:59:59.000Z

486

Fluorine Abundance Variations in Red Giants of the Globular Cluster M4 and Early-Cluster Chemical Pollution  

E-Print Network [OSTI]

We present fluorine abundances in seven red-giant members of the globular cluster M4 (NGC 6121). These abundances were derived from the HF (1--0) R9 line at 2.3357 microns in high-resolution infrared spectra obtained with the Phoenix spectrograph on Gemini-South. Many abundances in the target stars have been studied previously, so that their overall abundance distributions are well-mapped. The abundance of fluorine is found to vary by more than a factor of 6, with the F-19 variations being correlated with the already established oxygen variations, and anti-correlated with the sodium and aluminium variations. In this paper we thus add fluorine to the list of elements known to vary in globular cluster stars, and this provides further evidence that H-burning is the root cause of the chemical inhomegeneities. The fact that F-19 is found to decrease in the M4 stars, as the signature of H-burning appears, indicates that the polluting stars must have masses greater than about 3.5 solar masses, as less massive stars than this should produce, not destroy, fluorine.

V. V. Smith; K. Cunha; I. I. Ivans; J. C. Lattanzio; K. H. Hinkle

2005-06-30T23:59:59.000Z

487

A new solar fluorine abundance and a fluorine determination in the two open clusters M 67 and NGC 6404  

E-Print Network [OSTI]

We present a new determination of the solar fluorine abundance together with abundance measurements of fluorine in two Galactic open clusters. We analyzed a sunspot spectrum, observed by L. Wallace and W. Livingston with the FTS at the McMath/Pierce Solar Telescope situated on Kitt Peak and spectra of four giants in the old cluster M 67 (~4.5 Gyr) and three giants in the young cluster NGC 6404 (~0.5 Gyr), obtained with the CRIRES spectrograph at VLT. Fluorine was measured through synthesis of the available HF lines. We adopted the recent set of experimental molecular parameters of HF delivered by the HITRAN database, and found a new solar fluorine abundance of A(F)=3.80+/-0.25, in good agreement with the M 67 average fluorine abundance of A(F) = 3.89+/-0.20. The new solar abundance is significantly lower than the previous estimate, mostly due to the new set of experimental molecular parameters adopted in this study. The used modern spectrosynthesis tools, together with the agreement with the results in open c...

Maiorca, E; Uttenthaler, S; Randich, S; Busso, M; Magrini, L

2014-01-01T23:59:59.000Z

488

ISO SWS Observations of H II Regions in NGC 6822 and I ZW 36: Sulfur Abundances and Temperature Fluctuations  

E-Print Network [OSTI]

We report ISO SWS infrared spectroscopy of the H II region Hubble V in NGC 6822 and the blue compact dwarf galaxy I Zw 36. Observations of Br alpha, [S III] at 18.7 and 33.5 microns, and [S IV] at 10.5 microns are used to determine ionic sulfur abundances in these H II regions. There is relatively good agreement between our observations and predictions of S^+3 abundances based on photoionization calculations, although there is an offset in the sense that the models overpredict the S^+3 abundances. We emphasize a need for more observations of this type in order to place nebular sulfur abundance determinations on firmer ground. The S/O ratios derived using the ISO observations in combination with optical data are consistent with values of S/O, derived from optical measurements of other metal-poor galaxies. We present a new formalism for the simultaneous determination of the temperature, temperature fluctuations, and abundances in a nebula, given a mix of optical and infrared observed line ratios. The uncertainties in our ISO measurements and the lack of observations of [S III] lambda 9532 or lambda 9069 do not allow an accurate determination of the amplitude of temperature fluctuations for Hubble V and I Zw 36. Finally, using synthetic data, we illustrate the diagnostic power and limitations of our new method.

Joshua G. Nollenberg; Evan D. Skillman; Donald R. Garnett; Harriet L. Dinerstein

2002-09-04T23:59:59.000Z

489

Measurement of the double beta decay half-life of ^{100}Mo to the 0^{+}_{1} excited state, and ^{48}Ca to the ground state in the NEMO 3 experiment.  

E-Print Network [OSTI]

??NEMO 3 is a double beta decay experiment situated in the Fréjus tunnel which runs between France and Italy. If neutrinoless double beta decay is… (more)

King, S.L.

2009-01-01T23:59:59.000Z

490

Natural Resources Protection Act (Maine)  

Broader source: Energy.gov [DOE]

Maine's Department of Environmental Protection requires permits for most activities that occur in a protected natural resource area or adjacent to water resources such as rivers or wetlands. An ...

491

NATURAL RESOURCES CONSERVATION Environmental Conservation  

E-Print Network [OSTI]

NATURAL RESOURCES CONSERVATION Environmental Conservation Fall Semester Spring Semester Freshman/12 #12;***For the Environmental Conservation concentration, students must complete 18 additional conservation and/or environmentally-related credits in a curriculum plan designed to meet specific goals

Schweik, Charles M.

492

NATURAL RESOURCES CONSERVATION ENVIRONMENTAL CONSERVATION  

E-Print Network [OSTI]

NATURAL RESOURCES CONSERVATION ENVIRONMENTAL CONSERVATION For students entering after 8 ____________________________________________________________________ Requirements for the major = 76 credits, plus an additional 18 credits in conservation/environmentally related Completion of a plan that incorporates 18 additional credits in conservation or environmentally related

Schweik, Charles M.

493

Regulation of Natural Gas (Texas)  

Broader source: Energy.gov [DOE]

This legislation provides for the protection of public and private interests with regards to natural gas production, prohibits waste, and compels ratable production to enable owners of gas in a...

494

Natural Language Processing with Python  

E-Print Network [OSTI]

· Cambridge · Farnham · Köln · Sebastopol · Taipei · Tokyo #12;Natural Language Processing with Python Gravenstein Highway North, Sebastopol, CA 95472. O'Reilly books may be purchased for educational, business

Smith, Marc L.

495

Natural Gas Monthly August 1998  

SciTech Connect (OSTI)

The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. Explanatory notes supplement the information found in tables of the report. A description of the data collection surveys that support the NGM is provided. A glossary of the terms used in this report is also provided to assist readers in understanding the data presented in this publication.

NONE

1998-08-01T23:59:59.000Z

496

Afghanistan's energy and natural resources  

SciTech Connect (OSTI)

This study provides a resource perspective from which to better plan the necessary steps toward the viable reconstruction and economic development of post war Afghanistan. The vast availability of natural resources affords the opportunity to formulate a framework upon which Afghanistan can grow and prosper in the future. The paper includes the following sections: Historical Overview: Thwarted Opportunities; Natural Resources: A Survey of Possibilities; The Future: Post War Rehabilitation and Reconstruction; and Conclusions: Future Energy Sources.

Balcome-Rawding, R.; Porter, K.C.

1989-10-01T23:59:59.000Z

497

Possible discovery of the r-process characteristics in the abundances of metal-rich barium stars  

E-Print Network [OSTI]

We study the abundance distributions of a sample of metal-rich barium stars provided by Pereira et al. (2011) to investigate the s- and r-process nucleosynthesis in the metal-rich environment. We compared the theoretical results predicted by a parametric model with the observed abundances of the metal-rich barium stars. We found that six barium stars have a significant r-process characteristic, and we divided the barium stars into two groups: the r-rich barium stars ($C_r>5.0$, [La/Nd]\\,$pollution, although their abundance patterns can be fitted very well when the pre-enrichment hypothesis is included. The fact that we can not explain them well using the s-process nucleosynthesis alone may be due to our incomplete knowledge on the production of Nd, Eu, and other relevant elements by the ...

Cui, W Y; Shi, J R; Zhao, G; Wang, W J; Niu, P

2014-01-01T23:59:59.000Z

498

Natural gas monthly, November 1997  

SciTech Connect (OSTI)

This issue of the Natural Gas Monthly presents the most recent estimates of natural gas data from the Energy Information Administration. Estimates extend through November for many data series, and through August for most natural gas prices. Highlights of the most recent data estimates are: (1) Preliminary estimates of dry natural gas production and total consumption available through November 1997 indicate that both series are on track to end the year at levels close to those of 1996. Cumulative dry production is one-half percent higher than in 1996 and consumption is one-half percent lower. (2) Natural gas production is estimated to be 52.6 billion cubic feet per day in November 1997, the highest rate since March 1997. (3) After falling 8 percent in July 1997, the national average wellhead price rose 10 percent in August 1997, reaching an estimated $2.21 per thousand cubic feet. (4) Milder weather in November 1997 compared to November 1996 has resulted in significantly lower levels of residential consumption of natural gas and net storage withdrawls than a year ago. The November 1997 estimates of residential consumption and net withdrawls are 9 and 20 percent lower, respectively, than in November 1996.

NONE

1997-11-01T23:59:59.000Z

499

Oxygen abundances in metal-poor subgiants as determined from [O I], O I and OH lines  

E-Print Network [OSTI]

The debate on the oxygen abundances of metal-poor stars has its origin in contradictory results obtained using different abundance indicators. To achieve a better understanding of the problem we have acquired high quality spectra with the Ultraviolet and Visual Echelle Spectrograph at VLT, with a signal-to-noise of the order of 100 in the near ultraviolet and 500 in the optical and near infrared wavelength range. Three different oxygen abundance indicators, OH ultraviolet lines around 310.0 nm, the [OI] line at 630.03 nm and the OI lines at 777.1-5 nm were observed in the spectra of 13 metal-poor subgiants with -3.0Oxygen abundances were obtained from the analysis of these indicators which was carried out assuming local thermodynamic equilibrium and plane-parallel model atmospheres. Abundances derived from OI were corrected for departures from local thermodynamic equilibrium. Stellar parameters were computed using Teff-vs-color calibrations based on the infrared flux method and Balmer line profiles, Hipparcos parallaxes and FeII lines. [O/Fe] values derived from the forbidden line at 630.03 nm are consistent with an oxygen/iron ratio that varies linearly with [Fe/H] as [O/Fe]}=-0.09(+/-0.08)[Fe/H]+0.36(+/-0.15). Values based on the OI triplet are on average 0.19+/-0.22 dex(s.d.) higher than the values based on the forbidden line while the agreement between OH ultraviolet lines and the forbidden line is much better with a mean difference of the order of -0.09+/-0.25 dex(s.d.). In general, our results follow the same trend as previously published results with the exception of the ones based on OH ultraviolet lines. In that case our results lie below the values which gave rise to the oxygen abundance debate for metal-poor stars.

A. E. García Pérez; M. Asplund; F. Primas; P. E. Nissen; B. Gustafsson

2005-12-12T23:59:59.000Z

500

Easing the Natural Gas Crisis: Reducing Natural Gas Prices Through Electricity Supply Diversification -- Testimony  

E-Print Network [OSTI]

NANGAS (North American Natural Gas Analysis System), E2020 (Modeling Forum (EMF). 2003. Natural Gas, Fuel Diversity and2003. Increasing U.S. Natural Gas Supplies: A Discussion

Wiser, Ryan

2005-01-01T23:59:59.000Z