... The measured natural isotopic abundance of tungsten agrees well with the theoretical ratios in the monomeric tungstate standard. ...

to be related to the rst ionization potential FIP of the element. Measurements of SW and. SEP established that, on average, the ratio of abundances of low ...

Raman scattering is used to measure isotope ratios and/or isotopic abundances. A beam of quasi-monochromatic photons is directed onto the sample to be analyzed, and the resulting Raman-scattered photons are detected and counted for each isotopic species of interest. These photon counts are treated mathematically to yield the desired ...

Following Thomson's discovery of stable isotopes in non-radioactive chemical elements, the derivation of atomic weight values from mass spectrometric measurements of isotopic abundance ratios moved very slowly. Forty years later, only 3 1/2 % of the recom...

We propose to develop new technologies with support provided by PIDDP that will enable the in situ measurements of abundances and stable isotope ratios in important radiatively and biogenically active gases such as carbon dioxide, carbon monoxide, water, ...

Samples were analysed for CO concentrations and the isotopic content of 14C. ... Brenninkmeijer, C.A.M. Measurement of the abundance of CO-14 in the ...

Along with my usual weekly review of the published literature for new nuclear data, I also search for new candidates for best measurements of isotopic abundances from a single source. Most of the published articles, that I previously had found in the Rese...

We have measured the interstellar (/sup 17/O)/(/sup 18/O) isotope abundance ratio in eight giant molecule clouds using the J=1..-->..J=0 transition of carbon monoxide at approx.2.7 mm. The average interstellar ratio derived from these data is 0.24, a value which is significantly higher than the corresponding ...

Measurement of isotope ratios of Calcium is very useful in many fields. So we demonstrated the measurement of isotope ratios of {sup 40}Ca{sup +}(abundance 96.4%) to {sup 44}Ca{sup +}(2.09%) ions in a linear Paul trap with several laser lights tuning to the isotope shifts. And we found that the ...

Measurement of isotope ratios of Calcium is very useful in many fields. So we demonstrated the measurement of isotope ratios of 40Ca+ (abundance 96.4%) to 44Ca+ (2.09%) ions in a linear Paul trap with several laser lights tuning to the isotope shifts. And we found that the experimental ...

Oxygen is abundant in the Sun, yet the solar oxygen abundance has not been measured with high accuracy. Using long-term solar wind data from the Ulysses spacecraft, von Steiger et al. measured the flux of oxygen ions, the flux of protons, and the ratio of the two. The new ...

Jan 1, 1979 ... The abundances of Li, Be, and B and the isotopic ratios of Li and B have been measured by ion microprobe in melilite, pyroxene, anorthite, ...

Fe/O and other element abundance ratios, suggesting that the elemental and isotopic fractionation are governed by the same process. 1 Introduction: ...

N2), as well as neon and argon, would provide a good quantitative estimate of the processes ... example, the isotopic composition of atmospheric neon on ...

Relative abundances of oxygen, neon, and magnesium have been derived for a sample of nine solar active regions, flares, and an erupting prominance by combining plots of the ion differential emission measures. The observations were photographed in the 300-600 A range by the Naval Research Laboratory (NRL) spectroheliograph on Skylab. Methods for deriving ...

Measurements of actinide and light REE (LREE) abundances and of phosphate abundances in equilibrated ordinary chondrites were obtained and were used to define the Pu abundance in the solar system and to determine the degree of variation of actinide and LREE abundances. The results were also ...

... to millennia) (35, 53). CONCLUSIONS In conclusion, natural abundance stable isotopic ratios in biota and sediments provide a useful ... B. Fry, and R. M. Holmes. 1997. Natural abundance-level measurement...

The first measurements of atmospheric acetone abundances over an extended altitude range (5900-11,300 m) covering the lowermost part of the stratosphere and the upper troposphere are reported. The measured upper tropospheric abundances, averaging 120 parts per trillion by volume, are substantially lower than the ...

One drop of 200 mg/ml LiI solution is deposited in the ionization case. Under conditions such that the max peaks of Li/sup 7/ and Li/sup 6/ can be obtained, the peaks due to these isotopes are recorded repeatedly. More than 20 measured values of the abundance ratio in the region around the point on which the ionization ...

The methane abundance in the lower Jovian stratosphere is measured using the Galilean satellite eclipse technique. The average mixing ratio at the locations measured is larger than the expected value for a solar abundance of carbon with the possibility of some zenographic variation. ...

An evaluation method of the neutron fluence and mean spectrum with which samples have been irradiated is proposed. The principle is based on measuring the change of the isotopic abundance ratios of arbitrary pairs of nuclides having different neutron abso...

Resonance effects of isotope ratio measurements using three-photon one-color RIMS in lead are discussed. The shape of the ionization signal is considered for the case of a non-monochromatic laser field. The intensity of the laser radiation is adjusted to be low enough to cause saturation of the transitions. The variation of the isotope ...

We present an abundance analysis of a sample of 33 hydrogen-rich (DA) white dwarfs. We have used archival high-resolution spectra to measure abundances of calcium, magnesium and iron in a set of 30 objects. In addition, we present preliminary calcium abundances in three new white dwarfs based on low-dispersion ...

The atmospheric abundances of carbon dioxide and methane have increased dramatically during the industrial era. Measurements of the isotopic composition of these gases can provide a powerful tool for quantifying their sources and sinks. This report descri...

A nondestructive method for determining plutonium isotopic abundance ratios, based on the detection and measurement of the gamma rays emitted, is now being accepted as routine for solution samples. The analysis of solid samples is of more general interest...

The Viking gas chromatograph mass spectrometer experiment provided significant data on the atmospheric composition at the surface of Mars, including measurements of several isotope ratios. However, the limited dynamic range of this mass spectrometer resul...

A Mars surface lander Gas Chromatograph Mass Spectrometer (GCMS) is described to measure the chemical composition of abundant and trace volatile species and isotope ratios for noble gases and other elements. These measurements are relevant to the study of...

Now that we know the baryon to photon ratio to 5% from the cosmic microwave background, Big Bang Nucleosynthesis using standard physics predicts the abundances of five light nuclei with no free parameters. The Deuterium to Hydrogen ratio measured towards quasars agrees with the prediction to within 10%, but there ...

Now that we know the baryon to photon ratio to 5% from the cosmic microwave background, Big Bang Nucleosynthesis using standard physics predicts the abundances of five light nuclei with no free parameters. The Deuterium to Hydrogen ratio measured towards quasars agrees with the prediction to within 10%, but there ...

The primordial ratio of deuterium to hydrogen nuclei (D/H), created as a result of the Big Bang, provides the most sensitive measure of the cosmological density of baryons. Measurements of the D/H ratio in the interstellar medium of our Galaxy place a strict lower limit on the primordial ratio, ...

We present measurements of the C18O/C17O abundance ratio based on observations of J=1-->0 lines of these isotopomers toward star-forming cores in the Taurus molecular cloud. Our data set includes measurements along 648 lines of sight through these clouds, covering both low and high column density regions. We ...

example, forming the ratio of the abundances of methanol and methylamine would result in .... anol and methylamine should give the abundance ratio ...

We present a new measurement of the antiproton-to-proton abundance ratio, pbar/p, in the cosmic radiation. The HEAT-pbar instrument, a balloon borne magnet spectrometer with precise rigidity and multiple energy loss measurement capability, was flown successfully in Spring 2000, at an average atmospheric depth of ...

Lick/IDS system absorption feature indices have been used to discover that abundance ratios such as [Mg/Fe] and [Na/Fe] in external galaxies do not necessarily track the ratios observed in the Milky Way. However, the Lick system measures only a handful of the elements that have measurable ...

Thorium and uranium abundances have been measured in the Jilin H5 chondrite by radiochemical neutron activation analysis. Although the abundances of (35.8 + or - 1.5) ppb Th and (14.9 + or - 0.9) ppb U are within the range of literature values, the ratio Th/U is about 25 percent lower than the average value for H ...

For the past twenty years, I have collected data on isotopic abundance measurements for the chemical elements and their variation in nature. A preliminary data file of both references and numerical information for complete isotopic abundance data and isotope ratios was originally produced at General Electric in the ...

He/Ne, Ne/Ar, and Ar/Kr abundance ratios of solar gases extracted by stepped heating, stepped oxidation, and stepped etching of lunar and meteoritic regoliths are significantly lower than ratios measured directly or predicted by model estimates. Of these,...

This paper describes the construction of a simple nomograph for finding solutions for t 1 and t 2 in the formula, R = ( e ' t 1 - e ' t 2 )/ ( e t 1 - e glt 2 ) which is useful for interpreting anomalous lead isotope abundances. The nomograph does not require interpolation. Formulae are given for the slope of the best line through the ...

The deuterium-hydrogen abundance ratio in the Venus atmosphere was measured while the inlets to the Pioneer Venus large probe mass spectrometer were coated with sulfuric acid from Venus' clouds. The ratio is (1.6 +- 0.2) x 10/sup -2/. The hundredfold enrichment of deuterium means that at least 0.3% of a ...

Resonance ionization mass spectrometry (RIMS) has become a sensitive and highly selective technique for the determination of extremely low elemental or isotopic abundances, involving isotope ratio measurements with dynamical ranges of 109 and beyond. The experimental detection limits are as low as 106 atoms per sample, and isotopic ...

... Title : ABUNDANCES OF ELEMENTS IN STARS AND NEBULAE (DETERMINATION OF RATIO OF GAS PRESSURE TOELECTRON PRESSURE ...

The utility of the emission-line ratio (3727 + 4959 + 5007 A)/H-beta as an estimate of the total oxygen abundance in H II regions of low abundance (less than 10 percent of the solar value) is discussed. Using both observational data where the 4363A line is measured and model H II regions it is concluded that, for ...

A brief description is given of the thermal ionizaiion spectrometer used for isotope abundance measurements. Measurements carried out with this spectrometer on the /sup 235/U//sup 238/U ratio yield a precision of about 0.5%. The technique of isotope dilution in measuring isotope ...

Appropriate corrections for 2H and 18O natural abundance are necessary in energy expenditure measurements with the doubly labeled water (DLW) method. The contribution of natural abundance variations to errors in the method is generally ignored if an appropriate dose level is given. Calculation of the appropriate dose level assumes that ...

The Rb/sup 85//Rb/sup 87/ abundance ratio for a reference sample of rubidium sulfate was determined as 2.5995 450 deg C in a 0.0015 (95 per cent confidence interval) on a mass spectrometer with a 12-inch radius of curvature and a triple-filament mode of ionization. The abundance ratio was ...

Along with my usual weekly review of the published literature for new nuclear data, I also search for new candidates for best measurements of isotopic abundances from a single source. Most of the published articles, that I previously had found in the Research Library at the Brookhaven Lab, have already been sent to the members of the Atomic Weights ...

Solar energetic particles (SEPs) provide a measurement of coronal element abundances that is highly independent of the ionization states and temperature of the ions in the source plasma. The most complete measurements come from large 'gradual' events where ambient coronal plasma is swept up by the expanding shock wave from a coronal ...

Measurements of actinide and light REE (LREE) abundances and of phosphate abundances in equilibrated

XMM-Newton observations of 19 galaxy clusters are used to measure the elemental abundances and their spatial distributions in the intracluster medium. The sample mainly consists of X-ray bright and relaxed clusters with a cD galaxy. Along with detailed Si, S and Fe radial abundance distributions within 300-700 kpc in radius, the O ...

Following Thomson's discovery of stable isotopes in non-radioactive chemical elements, the derivation of atomic weight values from mass spectrometric measurements of isotopic abundance ratios moved very slowly. Forty years later, only 3 1/2 % of the recommended values were based on mass spectrometric ...

If deuterium is made primarily in stars, then according to current models of galactic evolution it should have a higher abundance in the metal-rich parts of the Galaxy. If it is produced only in the initial big bang, then astration causes a decrease in D abundance with increasing metal abundance z. Since the sign of the ...

The interior structure of the Sun can be studied with great accuracy using observations of its oscillations, similar to seismology of the Earth. Precise agreement between helioseismological measurements and predictions of theoretical solar models has been a triumph of modern astrophysics. A recent downward revision by 25-35 per cent of the solar abundances ...

... Title : DETERMINATION OF THE ISOTOPIC RATIOS OF ... Descriptors : *CARBON, *HYDROGEN, ABUNDANCE, CHEMICAL ANALYSIS, ISOTOPES. ...

... abundances is given only for the most abundant isotope, so the ... Analysis of SW elemental abundance data from the NASA Genesis mission is not ...

Oscillator strengths have been determined from measurements of radiative lifetimes and branching ratios for 154 lines of Y I and 66 lines of Y II. These data are used, together with equivalent widths measured on the Jungfraujoch solar atlas, to perform a new determination of the solar abundance of yttrium: A/sub Y/ ...

The 60 and 100 micron cirrus emission around 256 lines of sight in the IRAS all-sky survey was measured, and the flux averages were used to study the distribution, variations, and correlations of the IRAS infrared cirrus fluxes with various interstellar parameters. It was found that the 60 and 100 micron fluxes correlate with the depletion of Si and show a trend with the ...

To study the origin of the large abundances of complex organic molecules in the Galactic center (GC), we have carried out a systematic study of the complex organic molecules CH3OH, C2H5OH, (CH3)2O, HCOOCH3, HCOOH, CH3COOH, H2CO and CS toward 40 GC molecular clouds. Using the LTE approximation, we have derived the physical properties of GC molecular clouds and the ...

The aim of the proposal was to determine the nitrogen to carbon abundance ratios from transition layer lines in stars with different Teff and luminosities. The equations which give the surface emission line fluxes and the measured ratio of the NV to CIV emission line fluxes are presented and explained. The ...

During the past three years the Rochester MP tandem accelerator and associated equipment have been used to develop the techniques for the detection of naturally occuring radioisotopes and rare atoms such as the platinum group elements (PGE). Isotope ratios below 10/sup -15/ (for /sup 14/C and /sup 36/C1) and PGE element abundances down to at least 10/sup ...

Measurements of the O-16 and O-18 distribution functions in the solar wind at low to average solar wind speeds from the MASS instrument on the Wind spacecraft are reported. The O-16/O-18 density ratio is 450 +/- 130, a value consistent with terrestrial, solar photospheric, solar energetic particle, and galactic cosmic ray O-16/O-18 isotopic ...

Included are 34 papers and extracts of theses on studies of: isotopic compositions, diffusion, ratios, and variations in minerals; age measurements of minerals and formations; preparation of tracer solutions; and the calibration of spike solutions. (B.O.G.)

This report describes the electronic logic of a range telescope particle identifier. It discusses the logic and the nanosecond circuitry used to achieve a background rejection ratio of 10000 to 1, as well as the methods by which complicated data are cast ...

... sky-imaging with sun-tracking measurements, improving aerosol-gas separation (e.g., .... and biogeochemical) of the coastal ocean (turbid) water column. ... b) isotopic abundances and ratios of biogenic chemicals using small (on the ...

Mixing ratios are presented for ozone in the austral polar atmosphere during Aug. and Sept. of 1987. Since the mid-1970's, there has been a continuing decrease in the total column abundance of ozone over Antarctica during the late winter and early spring....

If a nearby source of low-energy helium is present, which has traversed a relatively small amount of matter and thus has not caused the production of a significant amount of H-2 or He-3, then these abundance ratios will be suppressed, particularly at low ...

The magnetic ion mass spectrometer was carried aboard Atmosphere Explorer C and Atmosphere Explorer D. The instrument measures the relative abundance of ionic species with very high sensitivity and very high mass resolution. Thus isotopic ratios for vario...

Contents: The reduction of uncertainties for absolute piston gage pressure measurements in the atmospheric pressure range; Absolute isotopic abundance ratios and atomic weight of a reference sample of nickel; The absolute isotopic composition and atomic w...

The isotope dilution mass spectrometry with (sup 233)U as a single internal standard has been developed. It can be used to determine the abundant ratio precisely in the uranium sample. It is an absolute measurement method based on gravimetry. The (sup 233...

example, in a given sample using the GC/MS+TCD, and subsequently measuring high precision isotopic and abundance ratios of all five of the noble gasses using the RARGA lab, the...

... USGS Fact Sheet July 1999 Measuring Variability in Forage Fish Abundance Introduction The abundance, distribution and h...

The primordial abundance of deuterium produced during Big Bang Nucleosynthesis (BBN) depends sensitively on the universal ratio of baryons to photons, an important cosmological parameter probed independently by the Cosmic Microwave Background (CMB) radiation. Observations of deuterium in high-redshift, low-metallicity QSO Absorption Line Systems (QSOALS) ...

The primordial abundance of deuterium produced during Big Bang Nucleosynthesis (BBN) depends sensitively on the universal ratio of baryons to photons, an important cosmological parameter probed independently by the Cosmic Microwave Background (CMB) radiation. Observations of deuterium in high-redshift, low-metallicity QSO Absorption Line Systems (QSOALS) ...

We present a brief and biased summary of key star-to-star abundance variations recently observed in globular clusters and some possible explanations for these variations. Measurements of the neutron-capture elements rubidium (Rb) and lead (Pb) in the globular clusters M 13 and NGC 6752 are then presented along with preliminary ...

The radiative lifetimes of 39 levels in V I have been measured by the method of laser-induced fluorescence from sputtered metal vapor. Emission branching ratios have been measured for these levels to determine absolute transition probabilities for 208 lines in the wavelength range 3180 � to 16,400 �. These transition probabilities ...

An overview is provided of six strategies for relative or absolute quantitation of protein abundances that are widely used in proteomic studies. Strengths and limitations are discussed. Four of these involve stable isotope labeling and isotope ratio measurements by mass spectrometry. In another, mass spectra are used to deconvolute ...

Methods for the measurement of the natural isotopic abundance of Li are discussed. The construction of a mass spectrometer for the analysis of solids is described. The influence of mass dependence of the evaporation, focusing of the ions, and secondary effects in the collector on accuracy and reproducibility are discussed in detail. An equation ...

Reference is made to studies by Biemont et al. (1982) and Kwiatkowski et al. (1982), in which 'modern' radiative lifetimes obtained by laser excitation were used to refine and update solar abundance values. The same procedure is extended here to Ru I. Radiative lifetimes are measured by laser excitation for 12 levels of Ru I. The results are combined with ...

We carried out a detailed study of the Si, Fe and Ni abundances in the cool cores of a representative sample of local galaxy clusters using XMM-Newton data. We first evaluated the systematic errors on the abundance measurements that are related to the instruments, the plasma codes and the spectral modeling. We then used the Si/Fe and ...

NH2 emission band strengths were measured in four comets and the NH2 column densities were determined in order to measure the ammonia content of the comets. The mean ammonia/water abundance ratio derived for the four comets is found to be 0.13 + or - 0.06 percent, with no significant variation among the comets. The ...

The purpose of this study is to develop a standard method for measuring modal abundances of glass in

We have determined the C-12/C-13 ratio in 8 M giants and combined our data with previous measurements to establish that in early M giants C-12/C-13 = 11.8 +/- 3.8, where 3.8 is the dispersion, not the standard error of the mean. This low ratio, comparable to the ratio in the coolest red giants and clump stars in ...

Representative abundances of the chemical elements for use as a solar abundance standard in astronomical and planetary studies are summarized. Updated abundance tables for solar system abundances based on meteorites and photospheric measurements are presented.

A series of volatile metal chelates were prepared for magnesium, calcium, iron, and cadmium. Extraction efficiency studies were done for magnesium and calcium in order to define the optimum conditions of pH and chelating agent required for recovery of these elements from aqueous media. Mass spectra of these chelates were obtained to evaluate their suitability for the ...

We present the abundance analyses for the neutron-capture elements, and discuss the observed abundance distributions in very metal-poor stars with excesses of r-process elements. As has been found by previous abundance studies, the star-to-star scatter in the abundances of neutron-capture elements are very large. ...

A list of idenifications is given for 65 lines measured on a Radcliffe coude spectrogram of the region lambda lambda 31203700 in the spectrum of 3 Cen A (B4p). Lines of Mn II are present; the resonance Be II doublet lambda 3130 is absent. Relative abundance or upper limits for Be and the iron-peak elements are derived by comparison with ...

Synthetic isotope mixtures for the calibration of carbon isotope amount ratio measurements have been prepared by mixing carbon tetrafluoride highly enriched in 13C with carbon tetrafluoride depleted in 13C. Mixing procedures based on volumetry and gravimetry are described. The mixtures served as primary measurement standards for the ...

The solar wind number density ratios of C/sup 6+/+C/sup 5+/ and N/sup 7+/+N/sup 6+/+N/sup 5+/ relative to O/sup 8+/+O/sup 7+/+O/sup 6+/ have been measured for the first time using data from the Charge-Energy-Mass (CHEM) spectrometer on the AMPTE/CCE spacecraft during four solar active periods from Sept. 19 to Nov. 1, 1984 when CCE traversed the subsolar ...

Stellar abundance ratios of very good quality are now available for a large number of stars in the solar vicinity. Moreover, for an increasing number of stars informations on kinematics is also available. The combined information on abundance and kinematics enables one to select objects belonging to the different components of our ...

>A 13-kg sample of highly purified Li/sub 2/CO/sub 3/ prepared from virgin ores was assayed to have an absolute /sup 6/Li//sup 7/Li abundance ratio of 0.0832 plus or minus 0.0002. This value was determined by a mass spectrometric comparison with a primary standard blended from specially prepared, highly enriched, well-characterized isotopic ...

The composition of the jovian atmosphere from 0.5 to 21 bars along the descent trajectory was determined by a quadrupole mass spectrometer on the Galileo probe. The mixing ratio of He (helium) to H2 (hydrogen), 0.156, is close to the solar ratio. The abundances of methane, water, argon, neon, and hydrogen sulfide were ...

The Viking gas chromatograph mass spectrometer experiment provided significant data on the atmospheric composition at the surface of Mars, including measurements of several isotope ratios. However, the limited dynamic range of this mass spectrometer resulted in marginal measurements for the important Kr and Xe isotopic ...

New lifetime measurements obtained using laser excitation are reported for levels in the 4d95p configuration of Pd I. These results are combined with branching ratios taken from Corliss and Bozman (1962) in order to provide a new set of oscillator strengths for eight transitions of solar interest. The photo spheric abundance deduced ...

The values of the isotope abundance ratio Li/sup 7/Li/sup 6/ obtained were 12.48 plus or minus 0.05 and 13.69 plus or minus 0.05 for two samples of lithium chloride. (W.D.M.)

with the expansion rate of the Universe during the big bang nucleosynthesis(BBN). This has been used to put limits depends on the baryon to photon ratio j. We can determine j by either measuring deuterium abundance that there are three neutrino species, and adopt j � 4:5 as inferred from the deuterium abundance, ...

An instrument, the Caltech High Energy Isotope Spectrometer Telescope, was developed to measure isotopic abundances of cosmic ray nuclei by employing an energy loss - residual energy technique. A detailed analysis was made of the mass resolution capabilities of this instrument. A formalism, based on the leaky box model of cosmic ray propagation, was ...

We present measurements of the relative abundances of cosmic-ray nuclei in the energy range of 500-3980 GeV/nucleon from the second flight of the Cosmic Ray Energetics And Mass (CREAM) balloon-borne experiment, extending the energy range beyond the reach of previ-ous measurements. Particle energy is determined using a sampling ...

The abundances of the actinide elements in the cosmic rays can provide critical constraints on the major sites of their acceleration. Using recent calculations of the r-process yields in core-collapse supernovae (SNe), we have determined the actinide abundances averaged over various assumed time intervals for their supernovae generation and their ...

The relative abundances of elements in the charge ranges of Z = 75-79 (platinum) and Z = 80-83 (lead) should be a sensitive indication of the contributions of the r- and s-processes in nucleosynthesis. Data from the HEAO 3 Heavy Nuclei Experiment are used to establish abundances, relative to iron, of these elements in the cosmic radiation, as well as the ...

Virioplankton dynamics at seven sample sites (from two freshwater lakes) with different trophic states were monitored over the period of a year. Water was sampled monthly from August 2004 to July 2005, and the abundances of viruses and bacteria were measured using direct epifluorescence microscopy counting. Results indicated that both natural and ...

We present abundance measurements in the tidally disrupted globular cluster NGC 6712. In this cluster, there are large star-to-star variations of the light elements C, N, O, F and Na. While such abundance variations are seen in every well-studied globular cluster, they are not found in field stars and indicate that clusters like NGC ...

Review was made on the determination of isotopic abundance ratio by the mass spectroscopic method, relation between the abundance ratio and atomic weight, problems in the relative measurement of the ratio, standard materials for the determination of the ...

Deuterium abundance measurements allow constraints to be put on Big Bang Nucleosynthesis, the baryonic content of the Universe, and the chemical evolution of galaxies. Such measurements in a variety of astrophysical environments are one of the main objectives of FUSE. According to the first FUSE results, the DH ...

Acceleration of energetic ions in solar flares produces narrow and broad nuclear ?-ray de-excitation lines, by nuclear interactions with the ambient solar atmosphere. Observations of several solar flare ?-ray spectra have been made since 1972 by satellite-borne ?-ray spectrometers on OSO 7, HEAO 3, SMM, HINOTORI, GRANAT, YOHKOH and CGRO. The line intensities depend directly on the ambient and ...

We present measurements of the neutron-capture elements Rb and Pb in five giant stars of the globular cluster NGC 6752 and Pb measurements in four giants of the globular cluster M13. The abundances were derived by comparing synthetic spectra with high-resolution, high signal-to-noise ratio spectra obtained using ...

We report measurements of the abundances relative to iron of the elements scandium through manganese in galactic cosmic rays in the energy interval 0.7 to 18 GeV/n using data collected by our cosmic ray telescope on the HEAO-3 satellite. The variation versus energy of the abundance ratio of manganese over iron is ...

Two ionic lines observed in the sun at 4068.334 and 5103.125 A and attributed to Sm have been analyzed assuming LTE. Oscillator strengths, obtained from lifetimes and branching-ratio measurements, are used for the abundance determination. Using the spectral synthesis method, the Sm abundance derived from these two ...

Problems related to the oscillator strengths in Sr II, Y II, and Zr II are discussed, and new accurate transition probabilities are reported that are derived from measurements of lifetimes and branching ratios of Y II and Zr II lines present in the spectra of chemically peculiar stars of the upper main sequence. These oscillator strengths are compared with ...

Listed are the [Mg/Fe], [Ca/Fe], [Ti/Fe] and [Si/Fe] abundance ratios for 650 K giants in four fields of the Galactic Bulge. Abundances were measured using standard 1D local thermodynamic equilibrium MARCS models and spectral synthesis using MOOG. The list also includes the metallicities [Fe/H] presented in Zoccali ...

Possible factors driving the sharply-tuned 22-year cycle in D/H isotope abundance ratios measured in cellulose from bristecone pines (Epstein and Yapp, 1976) are examined. It is concluded that this cycle is not due to external or surface activity of the sun (solar wind, flares, sunspot, etc.), as these phenomena exhibit a large phase ...

Significant abundances of trapped argon, krypton, and xenon have been measured in shock-altered phases of the achondritic meteorite Elephant Moraine 79001 from Antarctica. The relative elemental abundances, the high ratios of argon-40 to argon-36 (>/= 2000), and the high ratios of xenon-129 ...

In an effort to probe the extent of variations in the interstellar 7Li/6Li ratio seen previously, ultra-high-resolution (R~360,000), high signal-to-noise spectra of stars in the Perseus OB2 and Scorpius OB2 associations were obtained. These measurements confirm our earlier findings of an interstellar 7Li/6Li ratio of about 2 toward ? ...

A measurement of the primordial Lithium abundance would give a significant observational constraint to current big-bang nucleosynthesis models. Deuterium and helium abundances agree closely with predictions of current cosmological models, however, the predicted primordial lithium abundance is a factor of two above ...

We demonstrate a new method for determining the {sup 81}Kr/Kr ratio in environmental samples based upon two measurements: the {sup 85}Kr/{sup 81}Kr ratio measured by Atom Trap Trace Analysis (ATTA) and the {sup 85}Kr/Kr ratio measured by Low-Level Counting (LLC). This ...

We demonstrate a new method for determining the 81Kr/Kr ratio in environmental samples based upon two measurements: the 85Kr/81Kr ratio measured by Atom Trap Trace Analysis (ATTA) and the 85Kr/Kr ratio measured by Low-Level Counting (LLC). This method can be used to ...

We demonstrate a new method for determining the 81Kr/Kr ratio in environmental samples based upon two measurements: the 85Kr/81Kr ratio measured by Atom Trap Trace Analysis (ATTA) and the 85Kr/Kr ratio measured by Low-Level Counting (LLC). This method can be used to ...

We demonstrate a new method for determining the 81Kr/Kr ratio in environmental samples based upon two measurements: the 85Kr/81Kr ratio measured by Atom Trap Trace Analysis (ATTA) and the 85Kr/Kr ratio measured by Low-Level Counting (LLC). This method can be used to ...

Relative abundances of the five stable isotopes of titanium ({sup 46}Ti to {sup 50}Ti) are measured for 11 M dwarfs belonging to the thin disk (four stars), thick disk (three stars), the halo (one star), and either the thick or the thin disk (three stars). Over the metallicity range of the sample (-1< [Fe/H] <0), the isotopic ...

Relative abundances of the five stable isotopes of titanium (^46Ti to ^50Ti) are measured for 11 M dwarfs belonging to the thin disk (four stars), thick disk (three stars), the halo (one star), and either the thick or the thin disk (three stars). Over the metallicity range of the sample (-1<[Fe/H]<0), the isotopic ratios are ...

Relative abundances of the five stable isotopes of titanium (46Ti to 50Ti) are measured for 11 M dwarfs belonging to the thin disk (four stars), thick disk (three stars), the halo (one star), and either the thick or the thin disk (three stars). Over the metallicity range of the sample (-1< [Fe/H] <0), the isotopic ratios are ...

The primordial isotopic abundances of hydrogen, helium, and lithium provide an important test of big-bang nucleosynthesis (BBN) theory and constraints on the baryonic density of the universe. Recent advances in astronomical instrumentation, including the advent of the Keck 10m telescope and the Hubble Space Telescope (HST), have provided tighter ...

To compare the abundance of an element relative to hydrogen, take the ratio of the abundances: 5. How much more hydrogen is there in the solar system than ...

Moreover, there are abundance variation within structures: streamers' abundances are ... FIP element ratio that is anticorrelated with the solar wind speed. ...

Noble gas abundance and isotope ratios in the atmosphere of Jupiter from the Galileo Probe Mass Spectrometer. P. R. Mahaffyf H. B. Niemann,1 A. Alpert} ...

... Title : A Comparison of Elemental Abundance Ratios in SEP Events in Fast and Slow Solar Wind Regions. Descriptive Note : Journal article reprint. ...

Natural abundance stable isotope ratios represent a potentially valuable tool for studying fungal ecology. We measured 15N and 13C in ectomycorrhizal and saprotrophic macrofungi from two old-growth conifer forests, and in plants, woody debris, and soils. Fungi, plants, and so...

The relative intensity of the infrared absorption lines of HCO+ and HOC+ was measured as a function of the pressures of CO and H2. Under laboratory conditions, the isomerization process by CO was found to be a dominant depletion process of HOC+. A ratio of about 220 was obtained under the most favorable reaction conditions for production of HOC+. Although ...

Samples for measuring bacterial production and abundance were ... Bacterial production was measured by thymidine incorporation and leucine incorporation. ...

MEASUREMENT OF THE ABUNDANCE OF RADIOACTIVE 10Be AND OTHER ... designed to measure the isotopic composition of the light isotopes (3 ...

The abundances of up to 20 elements are measured in cool supergiants in Magellanic young populous clusters (NGC 330 in the SMC, NGC 1818 and NGC 2100 in the LMC), and compared to those, recently observed in samples of field supergiants in each Cloud (Hill et al. 1997). The analysis of the field supergiants showed no evidence of any ...

The hydrology of Honey Lake Basin was studied using environmental isotope measurements of approximately 130 water samples collected during 1995 and 1996. The principal analytical methods included hydrogen, oxygen and carbon stable isotope ratio measurements, radiocarbon and tritium dating, and measurements of ...

In order to measure the isotopic ratio of actinides, the upgrade of the accelerator mass spectrometry system at the Center for Isotopic Research on Cultural and Environmental heritage at the Second University of Naples, Italy, was performed. The beam emittance of 238U and the isotopic abundance sensitivity of 236U were ...

We present measurements of the neutron-capture elements Rb and Pb for bright giants in the globular clusters M4 and M5. The clusters are of similar metallicity ([Fe/H]~=-1.2), but M4 is decidedly s-process enriched relative to M5: [Ba/Fe]=+0.6 for M4 but 0.0 for M5. The Rb and Pb abundances were derived by comparing synthetic spectra with high-resolution, ...

Context. Gamma-ray bursts (GRBs) were the most energetic events after the Big Bang and they have been observed up to very high redshift. Measurements of the chemical abundances are now available for the galaxies hosting such events, which are assumed to originate from the explosion of very powerful supernovae (Type Ib/c), and provide the opportunity to ...

Age, overall abundance, and detailed, element-by-element abundances can be extracted from the integrated light of distant galaxies. The method, at its most basic, is merely the comparison of observed spectra with appropriate models. The relative ratios of elements C, N, O, Na, Mg, Ca, Sc, Ti, Cr, Mn, Fe, Co, Ni, Sr, and Ba can be ...

The New Horizons mission offered an exceptional opportunity to explore the distant Jovian magnetotail to over 2600 Jovian Radii. The Pluto Energetic Particle Spectrometer Science Investigation (PEPSSI) is a multi- directional time-of flight spectrometer measuring ions from ~15 keV to over 1 MeV, and electrons from 25 keV through ~0.5 MeV. Included in the ...

Isotopic abundance ratios are reported for a commercial silver nitrate, 13 samples of native silver, and 11 silver minerals of various compositions and from widely distributed deposits. Collateral measurements of known mixtures of nearly pure silver isotopes permit the determination of absolute abundance ...

Isotopic abundances for elements of interest to the earth science community can vary by many orders of magnitude. Commonly used detector systems (Faraday, Daly, SEM) can not encompass the entire dynamic range of interest and making measurements at the limits of the useful range for a single type of detector can also present special difficulties. ...

Oscillator strengths for 154 Y I lines and 66 Y II lines with wavelengths between 2948 and 7055 A are determined by combining laboratory measurements of radiative lifetimes and branching ratios. Lifetimes are presented for 34 levels of Y I and 14 levels of Y II; branching ratios are given for all levels below 9000 A with parity change ...

... of weekly checks of yellow pan trapping for flying insects. Abundance measurements with particular emphasis on crane ... ...

Diode-laser excited optogalvanic spectroscopy (OGS) of a glow discharge has been utilized to measure U-235/U-235 + U-238 isotope ratios. This ``optical mass spectrometric`` measurement has been demonstrated for a number of samples including uranium oxide, fluoride, and metal. Various diode-laser accessible atomic transitions in the 775 ...

The first part of this dissertation deals with the oxygen abundance of the Milky Way interstellar medium. Previous measurements had shown that oxygen in the ISM was depleted compared to its abundance in the sun. This dissertation presents new measurements of the ISM oxygen abundance taken in ...

Deuterium abundance measurements allow constraints to be put on Big Bang Nucleosynthesis, the baryonic content of the Universe, and the chemical evolution of galaxies. Such measurements in a variety of astrophysical environments are one of the main objectives of FUSE. According to the first FUSE results, the DH ...

We reanalyze the allowed parameters for inhomogeneous big bang nucleosynthesis in light of the WMAP constraints on the baryon-to-photon ratio ? and a recent measurement which has set the neutron lifetime to be 878.5�0.7�0.3sec. For a set baryon-to-photon ratio ? the new lifetime reduces the mass fraction of He4 by 0.0015 but does ...

Isotope variability due to natural processes provides important information for studying a variety of complex natural phenomena from the origins of a particular sample to the traces of biochemical reaction mechanisms. These measurements require high-precision determination of isotope ratios of a particular element involved. Isotope ...

Big bang nucleosynthesis can provide, via constraints on the expansion rate at that time, limits on possible variations in Newton's constant, G. The original analyses were performed before an independent measurement of the baryon-to-photon ratio from the cosmic microwave background was available. Combining this with recent measurements ...

It is suggested that the high abundance of beryllium and boron found in the carbonaceous chondrites is due to the presence of irradiated interstellar graphite grains in those meteorites. The beryllium and boron are produced in the grains by an energetic proton irradiation that occurred at some stage in their lifetime. The identical B-11/B-10 ratio in the ...

A balloon-borne cosmic-ray telescope containing 4 Cerenkov counters and a neon flash tube hodoscope was flown from Sioux City, Iowa in September 1974. The data have been reanalyzed, using information of flashed tubes to reject events due to proton and He interactions. The new event selection has reduced charge overlap between He and Li to an insignificant level, so that ...

Using the WMAP determination of the baryon density, the standard model of big bang nucleosynthesis yields relatively precise predictions of the primordial light-element abundances. Currently there are two significantly different observational determinations of the primordial helium abundance, and if only statistical errors in 4He ...

Aims: Chemical abundances in solar-type stars are still a much debated topic in many respects. In particular, planet-hosting stars are known to be metal-rich, but whether or not this peculiarity applies also to the chemical composition of the outer stellar atmospheres is still to be clarified. More in general, coronal and photospheric abundances in ...

In this communication, we show how the established principles of the International System of Units (SI) can be used to develop a basis for stable, comparable and coherent measurements of isotope ratios by mass spectrometry. We show that there are no important differences in the traceability of quantities that represent ratios of the ...

We have observed the HD 5--0 R (0) line on Saturn and Uranus. Values for the D/H abundance ratio computed from models for the atmospheres of these two planets are 5.5 +- 2.9 x 10/sup -5/ for Saturn and 3.0 +- 1.2 x 10/sup -5/ for Uranus. The D/H ratio for Jupiter of 5.1 +- 0.7 x 10/sup -5/ found from a measurement ...

Carbon and nitrogen are important products of the nucleosynthesis in evolved stars. Isotopic ratios derived from pre-solar dust shows that much of the carbon dust in the early solar system came from AGB stars with high excess of 13C but a very large spread in 15N/14N ratios. Traditionally, this is assigned to J-type carbon stars but this is not well ...

In the high latitude winter stratosphere, NO2 sequesters chlorine compounds which are extremely efficient at destroying ozone. During the nighttime, NO2 reacts with ozone to form N2O5 which acts as a reservoir of NO2. Under heavy aerosol loading, N2O5 may react with water on aerosol surfaces to form HNO3, a reservoir more resistant to photolysis. This heterogeneous reaction results in reduced NO2 ...

The aim of this paper is to provide fundamental parameters and abundances with a high accuracy for a large sample of cool main sequence stars. This study is part of wider project, in which the metallicity distribution of the local thin disc is investigated from a complete sample of G and K dwarfs within 25pc. The stars were observed at high resolution and a high ...

{The \\ion{Na}{x} X-ray lines between 10.9 and 11.2~\\AA\\ have attracted little attention but are of interest since they enable an estimate of the coronal abundance of Na to be made. This is of great interest in the continuing debate on the nature of the FIP (first ionization potential) effect. } {Observations of the \\ion{Na}{x} lines with the Solar Maximum Mission Flat ...

The effects of radiatively decaying, long-lived particles on big-bang nucleosynthesis (BBN) are discussed. If high-energy photons are emitted after BBN, they may change the abundances of the light elements through photodissociation processes, which may result in a significant discrepancy between the BBN theory and observation. We calculate the abundances ...

Detailed abundances are measured in cool (K type) supergiants in LMC young populous clusters (NGC 2004, NGC 2100 and NGC 1818), and compared to those, recently observed in samples of field supergiants in both Magellanic Clouds. This completes the work already done onthe SMC cluster NGC 330 (Hill et al., 1997b).The analysis of the field supergiants showed ...

The abundances of up to 20 elements are measured in cool supergiants in Magellanic young populous clusters (NGC330 in the SMC, NGC1818 and NGC2100 in the LMC), and compared to those, recently observed in samples of field supergiants in each Cloud. The analysis of the field supergiants showed no evidence of any abundance dispersion ...

We present high-quality observations of Neii optical recombination lines (ORLs) for the bright Saturn Nebula NGC 7009. The measured line fluxes are used to determine Ne2+/H+ abundance ratios. The results derived from individual multiplets of the 3s-3p and 3p-3d configurations agree reasonably well, although values derived from the ...