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Note: This page contains sample records for the topic "atomic absorption spectroscopy" from the National Library of EnergyBeta (NLEBeta).
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1

Atomic Spectroscopy Data Center  

Science Conference Proceedings (OSTI)

Atomic Spectroscopy Data Center. Summary: ... Atomic Spectroscopy Data Webpage. End Date: ongoing. Lead Organizational Unit: physlab. Contact. ...

2013-06-06T23:59:59.000Z

2

VUV absorption spectroscopy measurements of the role of fast neutral atoms in high-power gap breakdown  

DOE Green Energy (OSTI)

The maximum power achieved in a wide variety of high-power devices, including electron and ion diodes, z pinches, and microwave generators, is presently limited by anode-cathode gap breakdown. A frequently-discussed hypothesis for this effect is ionization of fast neutral atoms injected throughout the anode-cathode gap during the power pulse. The authors describe a newly-developed diagnostic tool that provides the first direct test of this hypothesis. Time-resolved vacuum-ultraviolet absorption spectroscopy is used to directly probe fast neutral atoms with 1 mm spatial resolution in the 10 mm anode-cathode gap of the SABRE 5 MV, 1 TW applied-B ion diode. Absorption spectra collected during Ar RF glow discharges and with CO{sub 2} gas fills confirm the reliability of the diagnostic technique. Throughout the 50--100 ns ion diode pulses no measurable neutral absorption is seen, setting upper limits of 0.12--1.5 x 10{sup 14} cm{sup {minus}3} for ground state fast neutral atom densities of H, C, N, O, F. The absence of molecular absorption bands also sets upper limits of 0.16--1.2 x 10{sup 15} cm{sup {minus}3} for common simple molecules. These limits are low enough to rule out ionization throughout the gap as a breakdown mechanism. This technique can now be applied to quantify the role of neutral atoms in other high-power devices.

FILUK,A.B.; BAILEY,JAMES E.; CUNEO,MICHAEL E.; LAKE,PATRICK WAYNE; NASH,THOMAS J.; NOACK,DONALD D.; MARON,Y.

2000-03-20T23:59:59.000Z

3

New Homogeneous Standards by Atomic Layer Deposition for Synchrotron X-ray Fluorescence and Absorption Spectroscopies.  

SciTech Connect

Quantification of synchrotron XRF analyses is typically done through comparisons with measurements on the NIST SRM 1832/1833 thin film standards. Unfortunately, these standards are inhomogeneous on small scales at the tens of percent level. We are synthesizing new homogeneous multilayer standards using the Atomic Layer Deposition technique and characterizing them using multiple analytical methods, including ellipsometry, Rutherford Back Scattering at Evans Analytical, Synchrotron X-ray Fluorescence (SXRF) at Advanced Photon Source (APS) Beamline 13-ID, Synchrotron X-ray Absorption Spectroscopy (XAS) at Advanced Light Source (ALS) Beamlines 11.0.2 and 5.3.2.1 and by electron microscopy techniques. Our motivation for developing much-needed cross-calibration of synchrotron techniques is borne from coordinated analyses of particles captured in the aerogel of the NASA Stardust Interstellar Dust Collector (SIDC). The Stardust Interstellar Dust Preliminary Examination (ISPE) team have characterized three sub-nanogram, {approx}1{micro}m-sized fragments considered as candidates to be the first contemporary interstellar dust ever collected, based on their chemistries and trajectories. The candidates were analyzed in small wedges of aerogel in which they were extracted from the larger collector, using high sensitivity, high spatial resolution >3 keV synchrotron x-ray fluorescence spectroscopy (SXRF) and <2 keV synchrotron x-ray transmission microscopy (STXM) during Stardust ISPE. The ISPE synchrotron techniques have complementary capabilities. Hard X-ray SXRF is sensitive to sub-fg mass of elements Z {ge} 20 (calcium) and has a spatial resolution as low as 90nm. X-ray Diffraction data were collected simultaneously with SXRF data. Soft X-ray STXM at ALS beamline 11.0.2 can detect fg-mass of most elements, including cosmochemically important oxygen, magnesium, aluminum and silicon, which are invisible to SXRF in this application. ALS beamline 11.0.2 has spatial resolution better than 25 nm. Limiting factors for Stardust STXM analyses were self-imposed limits of photon dose due to radiation damage concerns, and significant attenuation of <1500 eV X-rays by {approx}80{micro}m thick, {approx}25 mg/cm{sup 3} density silica aerogel capture medium. In practice, the ISPE team characterized the major, light elements using STXM (O, Mg, Al, Si) and the heavier minor and trace elements using SXRF. The two data sets overlapped only with minor Fe and Ni ({approx}1% mass abundance), providing few quantitative cross-checks. New improved standards for cross calibration are essential for consortium-based analyses of Stardust interstellar and cometary particles, IDPs. Indeed, they have far reaching application across the whole synchrotron-based analytical community. We have synthesized three ALD multilayers simultaneously on silicon nitride membranes and silicon and characterized them using RBS (on Si), XRF (on Si{sub 3}N{sub 4}) and STXM/XAS (holey Si{sub 3}N{sub 4}). The systems we have started to work with are Al-Zn-Fe and Y-Mg-Er. We have found these ALD multi-layers to be uniform at {micro}m- to nm scales, and have found excellent consistency between four analytical techniques so far. The ALD films can also be used as a standard for e-beam instruments, eg., TEM EELS or EDX. After some early issues with the consistency of coatings to the back-side of the membrane windows, we are confident to be able to show multi-analytical agreement to within 10%. As the precision improves, we can use the new standards to verify or improve the tabulated cross-sections.

Butterworth, A.L.; Becker, N.; Gainsforth, Z.; Lanzirotti, A.; Newville, M.; Proslier, T.; Stodolna, J.; Sutton, S.; Tyliszczak, T.; Westphal, A.J.; Zasadzinski, J. (UCB)

2012-03-13T23:59:59.000Z

4

Absorption-Line Spectroscopy of Planetary Nebulae with FUSE: Probing the Molecular, Atomic, and Ionized Gas  

E-Print Network (OSTI)

The central stars of planetary nebulae (PNe) are natural targets for FUSE due to their UV brightness. The FUSE spectra of many PNe show absorption features due to circumstellar material in species ranging from H_2 and neutrals in the photodissociation region (PDR) to ions resident in the H II region. We report results from a program designed to search for nebular components in the H_2 Lyman and Werner resonance lines that are responsible for the fluorescent excitation of H_2 in strong FUV radiation fields. Our failure to detect H_2 in absorption in several PNe with strong near-infrared H_2 emission indicates that the molecular material has an asymmetrical or clumpy distribution. We also detect enrichments in the s-process product Ge, find that Fe is not depleted into dust along at least one line of sight through a PN, and show that starlight fluorescence can affect the populations of the excited fine-structure levels of O I.

Dinerstein, H L; Bowers, C W; Dinerstein, Harriet L.; Bowers, Charles W.

2004-01-01T23:59:59.000Z

5

Absorption-Line Spectroscopy of Planetary Nebulae with FUSE: Probing the Molecular, Atomic, and Ionized Gas  

E-Print Network (OSTI)

The central stars of planetary nebulae (PNe) are natural targets for FUSE due to their UV brightness. The FUSE spectra of many PNe show absorption features due to circumstellar material in species ranging from H_2 and neutrals in the photodissociation region (PDR) to ions resident in the H II region. We report results from a program designed to search for nebular components in the H_2 Lyman and Werner resonance lines that are responsible for the fluorescent excitation of H_2 in strong FUV radiation fields. Our failure to detect H_2 in absorption in several PNe with strong near-infrared H_2 emission indicates that the molecular material has an asymmetrical or clumpy distribution. We also detect enrichments in the s-process product Ge, find that Fe is not depleted into dust along at least one line of sight through a PN, and show that starlight fluorescence can affect the populations of the excited fine-structure levels of O I.

Harriet L. Dinerstein; N. C. Sterling; Charles W. Bowers

2004-10-25T23:59:59.000Z

6

NIST Atomic Spectroscopy Data Center  

Science Conference Proceedings (OSTI)

Atomic Spectroscopy Data Center. ... Responds to user requests for data, literature references, and technical information. ...

2011-11-29T23:59:59.000Z

7

X-ray Absorption Spectroscopy  

SciTech Connect

This review gives a brief description of the theory and application of X-ray absorption spectroscopy, both X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS), especially, pertaining to photosynthesis. The advantages and limitations of the methods are discussed. Recent advances in extended EXAFS and polarized EXAFS using oriented membranes and single crystals are explained. Developments in theory in understanding the XANES spectra are described. The application of X-ray absorption spectroscopy to the study of the Mn4Ca cluster in Photosystem II is presented.

Yano, Junko; Yachandra, Vittal K.

2009-07-09T23:59:59.000Z

8

Short-range atomic structure of 1 wt. % Ga [delta]-stabilized plutonium by x-ray-absorption fine-structure spectroscopy  

Science Conference Proceedings (OSTI)

Using extended x-ray-absorption fine-structure (XAFS) spectroscopy we have determined the radii of the first three atomic shells around Ga and the first Pu shell in a fcc Pu alloy stabilized by 1 wt. % Ga. We find the Ga to be substitutional in the fcc lattice, with the first and second shells contracted by 3.7 and 0.9%, respectively, relative to distances expected from the lattice constant derived from x-ray diffraction. The lattice is well ordered around Ga, but there is considerable static disorder in all observed coordination shells of Pu. We discuss these results in relation to the mechanism by which Ga effects phase stabilization.

Cox, L.E.; Martinez, R. (Nuclear Materials Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)); Nickel, J.H.; Conradson, S.D.; Allen, P.G. (Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States))

1995-01-01T23:59:59.000Z

9

NIST: Atomic Spectroscopy Group - Homepage  

Science Conference Proceedings (OSTI)

... The program in atomic spectroscopy at NIST provides accurate reference data on spectral lines and energy levels for a wide variety of important ...

2013-07-31T23:59:59.000Z

10

Atomic Spectroscopy: An Introduction  

Science Conference Proceedings (OSTI)

... 60. A. de-Shalit and I. Talmi, Nuclear Shell Theory (Academic, New York, 1963). ... CE Moore, Atomic Energy Levels, Natl. Stand. Ref. ...

11

Spectroscopic differentiation between O-atom vacancy and divacancy defects, respectively, in TiO2 and HfO2 by X-ray absorption spectroscopy  

Science Conference Proceedings (OSTI)

Defect state features have been detected in second derivative O K edge spectra for thin films of nano-crystalline TiO"2 and HfO"2. Based on soft X-ray photoelectron band edge spectra, and the occurrence of occupied band edge 4f states in Gd(Sc,Ti)O"3, ... Keywords: Bound resonance states, Divacancies, Immobile and mobile vacancies, Monovacancies, Pre-edge regime, X-ray absorption spectroscopy

G. Lucovsky; K. -B. Chung; J. -W. Kim; D. Norlund

2009-07-01T23:59:59.000Z

12

Geek-Up[6.10.10]: Attosecond Absorption Spectroscopy and Kinked Nanopores |  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

6.10.10]: Attosecond Absorption Spectroscopy and Kinked 6.10.10]: Attosecond Absorption Spectroscopy and Kinked Nanopores Geek-Up[6.10.10]: Attosecond Absorption Spectroscopy and Kinked Nanopores August 6, 2010 - 6:07pm Addthis A classical diagram of a krypton atom shows its 36 electrons arranged in shells. | Photo Courtesy of: Berkeley Lab. A classical diagram of a krypton atom shows its 36 electrons arranged in shells. | Photo Courtesy of: Berkeley Lab. Elizabeth Meckes Elizabeth Meckes Director of User Experience & Digital Technologies, Office of Public Affairs Thanks to the attosecond absorption spectroscopy process, an international team of scientists from Max Planck Institute of Quantum Optics (MPQ), Lawrence Berkeley National Laboratory and the University of California at Berkeley were able to observe an atom's electrons moving in real time -

13

Atomic-absorption analysis in a graphite furnace fitted with a metal ballast collector  

SciTech Connect

One reason for the deterioration in sensitivity in the electrothermal atomic absorption spectroscopy of petroleum products is the uncontrolled spread and diffusion of the liquid throughout the furnace. This paper describes a metal ballast collector whose wettability and sorptive properties contain the sample and allow for its uniform and controlled evaporation and atomization.

Katskov, D.A.; Vasil' eva, L.A.; Grinshtein, I.L.; Savel' eva, G.O.

1987-10-01T23:59:59.000Z

14

Precision spectroscopy of the helium atom.  

SciTech Connect

Persistent efforts in both theory and experiment have yielded increasingly precise understanding of the helium atom. Because of its simplicity, the helium atom has long been a testing ground for relativistic and quantum electrodynamic effects in few-body atomic systems theoretically and experimentally. Comparison between theory and experiment of the helium spectroscopy in 1s2p{sup 3}P{sub J} can potentially extract a very precise value of the fine structure constant a. The helium atom can also be used to explore exotic nuclear structures. In this paper, we provide a brief review of the recent advances in precision calculations and measurements of the helium atom.

Hu, S.-M.; Lu, Z.-T.; Yan, Z.-C.; Physics; Univ. of Science and Technology of China; Univ. of Chicago; Univ. of New Brunswick

2009-06-01T23:59:59.000Z

15

Simulated X-Ray Absorption Spectroscopy on the Water Dimer  

DOE Green Energy (OSTI)

The ability of an individual H{sub 2}O molecule to form multiple hydrogen bonds with neighboring molecules makes it an ideal substance for the study of hydrogen bonding. X-ray absorption spectroscopy (XAS) can be used to study what intermolecular structures the hydrogen-bonded water molecules form. XAS excites core electrons from the oxygen 1 s atomic orbital to an unoccupied orbital. The resulting absorption spectrum shows the energy levels of the unoccupied orbitals, which in turn is dependent on the intermolecular structure of the H{sub 2}O system. Previous studies using molecular dynamics computer simulations have concluded that the intermolecular structure of liquid water is a distorted tetrahedron. Yet x-ray absorption spectra show discrepancies between liquid water and ice Ih, which is already known to have a rigid tetrahedral structure. The research group, which is based in the University of Sweden in Stockholm and the Stanford Synchrotron Radiation Laboratory at the Stanford Linear Accelerator Center, has studied the possible presence of broken hydrogen bonds in the liquid water intermolecular structure to explain these deviations. Computer simulations are used to construct theoretical absorption spectra for models of liquid water including broken hydrogen bonds. Creating such models requires controlling variables. The simplest method of isolating individual variables, such as hydrogen bond length and angles, is to study the water dimer. Here, the water dimer is used to study how the absorption spectra change with the way the water molecules are positioned and oriented relative to each other.

Wung, A

2004-02-05T23:59:59.000Z

16

Spectroscopy and atomic force microscopy of biomass  

NLE Websites -- All DOE Office Websites (Extended Search)

Spectroscopy Spectroscopy and atomic force microscopy of biomass L. Tetard a,b , A. Passian a,b,n , R.H. Farahi a , U.C. Kalluri c , B.H. Davison c , T. Thundat a,b a Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA b Department of Physics, University of Tennessee, Knoxville, TN 37996, USA c Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA a r t i c l e i n f o Keywords: Atomic force microscopy Spectroscopy Plant cells Biomass Nanomechanics a b s t r a c t Scanning probe microscopy has emerged as a powerful approach to a broader understanding of the molecular architecture of cell walls, which may shed light on the challenge of efficient cellulosic ethanol production. We have obtained preliminary images of both Populus and switchgrass samples using atomic force microscopy (AFM). The results show distinctive features that are shared by switchgrass

17

VARIOUS APPLICATIONS OF ZEEMAN ATOMIC ABSORPTION SPECTROSCOPY  

E-Print Network (OSTI)

at 1.5kHz to eliminate blackbody radiation from the furnace.The signal due to the blackbody radiation from the graphite

Koizumi, Hideaki

2011-01-01T23:59:59.000Z

18

VARIOUS APPLICATIONS OF ZEEMAN ATOMIC ABSORPTION SPECTROSCOPY  

E-Print Network (OSTI)

T. Hadeishi and R. D. McLaughlin, Science, 174, 404 (1971)T. Hadeishi, L. Leong, R. D. McLaughlin and B. D. Zak, Anal.D. A. Church, R. D. McLaughlin, B. D. Zak, M. Nakamura and

Koizumi, Hideaki

2011-01-01T23:59:59.000Z

19

Neutrino Spectroscopy with Atoms and Molecules  

E-Print Network (OSTI)

We give a comprehensive account of our proposed experimental method of using atoms or molecules in order to measure parameters of neutrinos still undetermined; the absolute mass scale, the mass hierarchy pattern (normal or inverted), the neutrino mass type (Majorana or Dirac), and the CP violating phases including Majorana phases. There are advantages of atomic targets, due to the closeness of available atomic energies to anticipated neutrino masses, over nuclear target experiments. Disadvantage of using atomic targets, the smallness of rates, is overcome by the macro-coherent amplification mechanism. The atomic or molecular process we use is a cooperative deexcitation of a collective body of atoms in a metastable level |e> emitting a neutrino pair and a photon; |e> -> |g> + gamma + nu_i nu_j where nu_i's are neutrino mass eigenstates. The macro-coherence is developed by trigger laser irradiation. We discuss aspects of the macro-coherence development by setting up the master equation for the target quantum state and propagating electric field. With a choice of heavy target atom or molecule such as Xe or I_2 that has a large M1 x E1 matrix element between |e> and |g>, we show that one can determine three neutrino masses along with the mass hierarchy pattern by measuring the photon spectral shape. If one uses a target of available energy of a fraction of 1 eV, Majorana CP phases may be determined. Our master equation, when applied to E1 x E1 transition such as pH_2 vibrational transition Xv=1 -> 0, can describe explosive PSR events in which most of the energy stored in |e> is released within a few nanoseconds. The present paper is intended to be self-contained explaining some details related theoretical works in the past, and further reports new simulations and our ongoing experimental efforts of the project to realize the neutrino mass spectroscopy using atoms/molecules.

Atsushi Fukumi; Susumu Kuma; Yuki Miyamoto; Kyo Nakajima; Itsuo Nakano; Hajime Nanjo; Chiaki Ohae; Noboru Sasao; Minoru Tanaka; Takashi Taniguchi; Satoshi Uetake; Tomonari Wakabayashi; Takuya Yamaguchi; Akihiro Yoshimi; Motohiko Yoshimura

2012-11-21T23:59:59.000Z

20

X-Ray Absorption Spectroscopy of Transition Metal-Magnesium Hydride Thin  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Absorption Spectroscopy of Transition Metal-Magnesium Hydride Thin X-Ray Absorption Spectroscopy of Transition Metal-Magnesium Hydride Thin Films Title X-Ray Absorption Spectroscopy of Transition Metal-Magnesium Hydride Thin Films Publication Type Journal Article LBNL Report Number LBNL-50574 Year of Publication 2002 Authors Richardson, Thomas J., Baker Farangis, Jonathan L. Slack, Ponnusamy Nachimuthu, Rupert C. C. Perera, Nobumichi Tamura, and Michael D. Rubin Journal Journal of Alloys and Compounds Volume 356-357 Start Page 204 Pagination 204-207 Date Published 08/2003 Keywords A. hydrogen storage materials, NEXAFS, thin film s; C. EXAFS, x-ray diffraction Abstract Mixed metal thin films containing magnesium and a first-row transition element exhibit very large changes in both reflectance and transmittance on exposure to hydrogen gas. Changes in electronic structure and coordination of the magnesium and transition metal atoms during hydrogen absorption were studied using dynamic in situ transmission mode X-ray absorption spectroscopy. Mg K-edge and Ni, Co, and Ti L-edge spectra reflect both reversible and irreversible changes in the metal environments. A significant shift in the nickel L absorption edge shows it to be an active participant in hydride formation. The effect on cobalt and titanium is much less dramatic, suggesting that these metals act primarily as catalysts for formation of magnesium hydride.

Note: This page contains sample records for the topic "atomic absorption spectroscopy" 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

Atomic hydrogen density measurements in an ion source plasma using a vacuum ultraviolet absorption spectrometer  

DOE Green Energy (OSTI)

A system to determine the density and temperature of ground state hydrogen atoms in a plasma by vacuum ultraviolet laser absorption spectroscopy is described. The continuous tunability of the spectrometer allows for analysis at any of the Lyman transitions. The narrow bandwidth of the laser system allows for the accurate determination of the absorption lineshape and hence the translational temperature. The utility of the system is exemplified by data obtained on an ion-source plasma. The measurements demonstrate the quality of the data as well as illustrating the behavior of this ion source under varying discharge conditions. 9 refs., 5 figs., 1 tab.

Stutzin, G.C.; Young, A.T.; Schlachter, A.S.; Stearns, J.W.; Leung, K.N.; Kunkel, W.B.; Worth, G.T.; Stevens, R.R.

1989-01-01T23:59:59.000Z

22

INFRARED ABSORPTION SPECTROSCOPY AND CHEMICAL KINETICS OF FREE RADICALS  

NLE Websites -- All DOE Office Websites (Extended Search)

mNAL PERFORMANCE REPORT mNAL PERFORMANCE REPORT for INFRARED ABSORPTION SPECTROSCOPY AND CHEMICAL KINETICS OF FREE RADICALS DE-FG05-85ER13439 1-AUG-1985 to 31-JUL-1994 Robert F. Curl and Graham P. Glass Principal Investigators Introduction This research was directed at the detection, monitoring, and study (by infrared absorption spectroscopy) of the chemical kinetic behavior of small free radical species thought to be important intermediates in combustion. The work typically progressed from the detection and analysis of the infrared spectrum of combustion radical to the utilization of the infrared spectrum thus obtained in the investigation of chemical kinetics of the radical species. The methodology employed was infrared kinetic spectroscopy. In this technique the radical is produced by UV flash photolysis using an excimer laser and then

23

Round-Robin Study of Methods for Trace Metal Analysis: Graphite Furnace Atomic Absorption Spectroscop-Cadmium, Arsenic and Chromium  

Science Conference Proceedings (OSTI)

Eighteen utility laboratories evaluated graphite furnace atomic absorption spectroscopy (GFAAS) methods for measuring cadmium, arsenic and chromium in a variety of utility aqueous streams. This EPRI Tailored Collaboration Project, part of the ongoing Analytical Methods Qualification (AMQ) program, will help utilities define reasonable pollutant discharge limits and effluent monitoring requirements.

1997-12-05T23:59:59.000Z

24

NIST: Atomic Spectroscopy Group - Past News  

Science Conference Proceedings (OSTI)

... of Atomic, Molecular, and Optical Physics of the American Physical Society (DAMOP) in ... and Determination of Relative Nuclear Charge Radius.". ...

2013-06-06T23:59:59.000Z

25

NIST: Atomic Spectroscopy Group - John Curry  

Science Conference Proceedings (OSTI)

... chemical equilibrium and deviations from thermodynamic equilibrium. I am also interested in the acquisition and compilation of basic atomic data. ...

2011-02-09T23:59:59.000Z

26

X-RAY ABSORPTION SPECTROSCOPY OF TRANSITION METAL-MAGNESIUM HYDRIDE FILMS  

NLE Websites -- All DOE Office Websites (Extended Search)

Spectroscopy of Transition Metal-Magnesium Spectroscopy of Transition Metal-Magnesium Hydride Thin Films T. J. Richardson a, *, B. Farangis a , J. L. Slack a , P. Nachimuthu b , R. Pereira b , N. Tamura b , and M. Rubin a a Environmental Energy Technologies Division, b Advanced Light Source, Ernest Orlando Lawrence Berkeley National Laboratory Berkeley, California 94720, USA *Corresponding author, E-mail address: tjrichardson@lbl.gov Abstract Mixed metal thin films containing magnesium and a first-row transition element exhibit very large changes in both reflectance and transmittance on exposure to hydrogen gas. Changes in electronic structure and coordination of the magnesium and transition metal atoms during hydrogen absorption were studied using dynamic in situ transmission mode X-ray absorption

27

Measuring of exhaust gas emissions using absorption spectroscopy  

Science Conference Proceedings (OSTI)

This paper describes an optical fibre sensor for the detection of NOx (NO2 and NO) and CO2 in the exhaust system of a road vehicle. The measurement is based on a free path interaction zone which is interrogated using ... Keywords: absorption spectroscopy, air pollution, carbon dioxide, emissions measurement, exhaust gas emissions, gas sensors, infrared, nitrogen dioxide, nitrogen oxide, optical fibre sensors, ultraviolet, vehicle emissions

Eamonn Hawe; Gerard Dooly; Colin Fitzpatrick; Paul Chambers; Elfed Lewis; W. Z. Zhao; T. Sun; K. T. V. Grattan; M. Degner; H. Ewald; S. Lochmann; G. Bramman; C. Wei; D. Hitchen; J. Lucas; A. Al-Shamma'a; E. Merlone-Borla; P. Faraldi; M. Pidria

2008-02-01T23:59:59.000Z

28

Radio-frequency spectroscopy of ultracold atomic Fermi gases  

E-Print Network (OSTI)

This thesis presents experiments investigating the phase diagram of ultracold atomic Fermi gases using radio-frequency spectroscopy. The tunability of many experimental parameters including the temperature, the interparticle ...

Schirotzek, Andre

2010-01-01T23:59:59.000Z

29

Resonant spectroscopy of the antihydrogen atom  

SciTech Connect

The spectra of the hydrogen and antihydrogen atoms in the presence of an external electric field are compared. It is shown that the nonresonant corrections to the transition frequency may contain terms linear in the electric field. The existence of these terms does not violate space and time parity and leads to a difference in the resonant spectroscopic measurements for the hydrogen and antihydrogen atoms in an external electric field.

Labzowsky, Leonti [St. Petersburg State University, 198504 Petrodvorets, St. Petersburg, Russia (Russian Federation); Petersburg Nuclear Physics Institute, 188350 Gatchina, St. Petersburg, Russia (Russian Federation); Solovyev, Dmitri [St. Petersburg State University, 198504 Petrodvorets, St. Petersburg, Russia (Russian Federation)

2003-07-01T23:59:59.000Z

30

Spectroscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Spectroscopy Spectroscopy Spectroscopy Print In spectroscopy experiments, a sample is illuminated with light and the various product particles (electrons, ions, or fluorescent photons) are detected and analyzed.The unifying feature is that some "property" of a material is measured as the x-ray (photon) energy is swept though a range of values. At the most basic level, one measures the absorption, transmission, or reflectivity of a sample as a function of photon energy. Probes that use the vacuum ultraviolet (VUV) region of the spectrum (10-100 eV) are very well matched to the elucidation of bonding in solids, surfaces, and molecules; to the investigation of electron-electron correlations in solids, atoms, and ions; and to the study of reaction pathways in chemical dynamics. At the lowest end of this energy range (below 1 eV) we have infrared, far-infrared, and terahertz spectroscopies, which are well matched to vibrational modes and other modes of excitation.

31

Spectroscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Spectroscopy Print Spectroscopy Print In spectroscopy experiments, a sample is illuminated with light and the various product particles (electrons, ions, or fluorescent photons) are detected and analyzed.The unifying feature is that some "property" of a material is measured as the x-ray (photon) energy is swept though a range of values. At the most basic level, one measures the absorption, transmission, or reflectivity of a sample as a function of photon energy. Probes that use the vacuum ultraviolet (VUV) region of the spectrum (10-100 eV) are very well matched to the elucidation of bonding in solids, surfaces, and molecules; to the investigation of electron-electron correlations in solids, atoms, and ions; and to the study of reaction pathways in chemical dynamics. At the lowest end of this energy range (below 1 eV) we have infrared, far-infrared, and terahertz spectroscopies, which are well matched to vibrational modes and other modes of excitation.

32

Spectroscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Spectroscopy Print Spectroscopy Print In spectroscopy experiments, a sample is illuminated with light and the various product particles (electrons, ions, or fluorescent photons) are detected and analyzed.The unifying feature is that some "property" of a material is measured as the x-ray (photon) energy is swept though a range of values. At the most basic level, one measures the absorption, transmission, or reflectivity of a sample as a function of photon energy. Probes that use the vacuum ultraviolet (VUV) region of the spectrum (10-100 eV) are very well matched to the elucidation of bonding in solids, surfaces, and molecules; to the investigation of electron-electron correlations in solids, atoms, and ions; and to the study of reaction pathways in chemical dynamics. At the lowest end of this energy range (below 1 eV) we have infrared, far-infrared, and terahertz spectroscopies, which are well matched to vibrational modes and other modes of excitation.

33

Single atom identification by energy dispersive x-ray spectroscopy  

SciTech Connect

Using aberration-corrected scanning transmission electron microscope and energy dispersive x-ray spectroscopy, single, isolated impurity atoms of silicon and platinum in monolayer and multilayer graphene are identified. Simultaneously acquired electron energy loss spectra confirm the elemental identification. Contamination difficulties are overcome by employing near-UHV sample conditions. Signal intensities agree within a factor of two with standardless estimates.

Lovejoy, T. C.; Dellby, N.; Krivanek, O. L. [Nion, 1102 8th St., Kirkland, Washington 98033 (United States); Ramasse, Q. M. [SuperSTEM Laboratory, STFC Daresbury, Keckwick Lane, Daresbury WA4 4AD (United Kingdom); Falke, M.; Kaeppel, A.; Terborg, R. [Bruker Nano GmbH, Schwarzschildstr. 12, 12489 Berlin (Germany); Zan, R. [School of Physics and Astronomy, University of Manchester, Manchester M13 9PL (United Kingdom)

2012-04-09T23:59:59.000Z

34

Introducing many-body physics using atomic spectroscopy  

E-Print Network (OSTI)

Atoms constitute relatively simple many-body systems, making them suitable objects for developing an understanding of basic aspects of many-body physics. Photoabsorption spectroscopy is a prominent method to study the electronic structure of atoms and the inherent many-body interactions. In this article the impact of many-body effects on well-known spectroscopic features such as Rydberg series, Fano resonances, Cooper minima, and giant resonances is studied, and related many-body phenomena in other fields are outlined. To calculate photoabsorption cross sections the time-dependent configuration interaction singles (TDCIS) model is employed. The conceptual clearness of TDCIS in combination with the compactness of atomic systems allows for a pedagogical introduction to many-body phenomena.

Krebs, Dietrich; Santra, Robin

2013-01-01T23:59:59.000Z

35

Results from Point Contact Tunnelling Spectroscopy and Atomic Layer Deposition  

SciTech Connect

We have shown previously that magnetic niobium oxides can influence the superconducting density of states at the surface of cavity-grade niobium coupons. We will present recent results obtained by Point Contact Tunneling spectroscopy (PCT) on coupons removed from hot and cold spots in a niobium cavity, as well as a comparative study of magnetic oxides on mild baked/unbaked electropolished coupons. We will also describe recent results obtained from coated cavities, ALD films properties and new materials using Atomic Layer Deposition (ALD).

Proslier, Th. [Illinois Institute of Technology; Zasadzinski, J. [Illinois Institute of Technology; Ciovati, Gianluigi [JLAB; Kneisel, Peter K. [JLAB; Elam, J. W. [ANL; Norem, J. [ANL; Pellin, M. J. [ANL

2009-11-01T23:59:59.000Z

36

Absorption spectroscopy in hollow-glass waveguides using infrared laser diodes  

Science Conference Proceedings (OSTI)

Hollow-glass waveguides may be a viable technology that, in some cases, may supplant heavier multi-pass cells such as White or Herriott cells for performing trace detection using tunable diode laser absorption spectroscopy. We report here a series of experiments for testing the suitability of waveguides for infrared spectroscopy. The loss characteristics of 1 mm bore diameter waveguides have been measured for straight and coiled lengths. Using direct absorption spectroscopy we have found that the absorption pathlength is approximately equal to the physical length of the waveguide. Broadband FM diode laser spectroscopy produces a comparable signal-to-noise ratio with less than a second of signal averaging. Finally, we have also performed near-infrared spectroscopy of nitrous oxide flowing through a waveguide using a telecommunications diode laser.

Blake, Thomas A.; Kelly, James F.; Stewart, Timothy L.; Hartman, John S.; Sharpe, Steven W.; Sams, Robert L.

2002-07-10T23:59:59.000Z

37

Infrared Spectroscopy of Atomic Lines in Gaseous Nebulae  

E-Print Network (OSTI)

Spectroscopy in the infrared provides a means to assess important properties of the plasma in gaseous nebulae. We present some of our own work that illustrates the need for interactions between the themes of this conference - astronomical data, atomic data, and plasma simulations. We undertook Infrared Space Observatory (ISO) observations with the intent of better understanding the effects of density variations in nebulae, particularly planetary nebulae (PNs), by determining average electron densities from the flux ratios of several fine-structure, IR emission lines. Instead, we are able to ascertain only minor density information because of several instances of the observed line flux ratios being out of range of the theoretical predictions using current atomic data. In these cases, the ISO data cannot presently be used to derive electron density, but rather provide direction for needed improvements in the atomic collision strengths. We have detected an unidentified (uid) strong emission line in an ISO/SWS spectrum of the Orion Nebula. The line has a rest wavelength 2.89350$\\pm$0.00003 $\\mu$m. A long-slit UKIRT observation confirms the presence of this line and shows that the emission is spatially extended and appears to be coincident with the brightest part of the ionized region. We do not detect the uid line in our SWS02 spectra of any of the several bright PNs which we observed for a comparable time. The need for basic atomic data, in this case wavelengths to aid species identification, is paramount for future progress. We look toward the future with a brief synopsis of upcoming or planned IR missions.

R. H. Rubin; R. J. Dufour; T. R. Geballe; S. W. J. Colgan; J. P. Harrington; S. D. Lord; A. L. Liao; D. A. Levine

2001-09-23T23:59:59.000Z

38

Method and apparatus for aerosol particle absorption spectroscopy  

DOE Patents (OSTI)

A method and apparatus for determining the absorption spectra, and other properties, of aerosol particles. A heating beam source provides a beam of electromagnetic energy which is scanned through the region of the spectrum which is of interest. Particles exposed to the heating beam which have absorption bands within the band width of the heating beam absorb energy from the beam. The particles are also illuminated by light of a wave length such that the light is scattered by the particles. The absorption spectra of the particles can thus be determined from an analysis of the scattered light since the absorption of energy by the particles will affect the way the light is scattered. Preferably the heating beam is modulated to simplify the analysis of the scattered light. In one embodiment the heating beam is intensity modulated so that the scattered light will also be intensity modulated when the particles absorb energy. In another embodiment the heating beam passes through an interferometer and the scattered light reflects the Fourier Transform of the absorption spectra.

Campillo, Anthony J. (Nesconset, NY); Lin, Horn-Bond (Manorville, NY)

1983-11-15T23:59:59.000Z

39

Measurement of H and H sub 2 populations in a low-temperature plasma by vacuum ultraviolet laser absorption spectroscopy  

DOE Green Energy (OSTI)

A new technique, vacuum ultraviolet laser absorption spectroscopy, has been developed to quantitatively determine the absolute density of H and H{sub 2} within a plasma. The technique is particularly well suited to measurement in a plasma, where high charged particle and photon backgrounds complicate other methods of detection. The high selectivity and sensitivity of the technique allows for the measurement of the rotational-vibrational state distribution of H{sub 2} as well as the translational temperature of the atoms and molecules. The technique has been used to study both pulsed and continuous plasma discharges. H{sub 2} state distributions show a high degree of internal excitation, with levels up to v=5 and J=8 being observed. Hydrogen atom measurements indicate that, even for modest discharge currents, the fraction of H{sub 2} molecules dissociated can be greater than 0.15.

Young, A.T.; Stutzin, G.C.; Schlachter, A.S.; Stearns, J.W.; Leung, K.N.; Kunkel, W.B. (Lawrence Berkeley Laboratory, Berkeley, California 94720 (US)); Worth, G.T.; Stevens, R.R. (Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (USA))

1989-10-20T23:59:59.000Z

40

Absolute atomic oxygen and nitrogen densities in radio-frequency driven atmospheric pressure cold plasmas: Synchrotron vacuum ultra-violet high-resolution Fourier-transform absorption measurements  

SciTech Connect

Reactive atomic species play a key role in emerging cold atmospheric pressure plasma applications, in particular, in plasma medicine. Absolute densities of atomic oxygen and atomic nitrogen were measured in a radio-frequency driven non-equilibrium plasma operated at atmospheric pressure using vacuum ultra-violet (VUV) absorption spectroscopy. The experiment was conducted on the DESIRS synchrotron beamline using a unique VUV Fourier-transform spectrometer. Measurements were carried out in plasmas operated in helium with air-like N{sub 2}/O{sub 2} (4:1) admixtures. A maximum in the O-atom concentration of (9.1 {+-} 0.7) Multiplication-Sign 10{sup 20} m{sup -3} was found at admixtures of 0.35 vol. %, while the N-atom concentration exhibits a maximum of (5.7 {+-} 0.4) Multiplication-Sign 10{sup 19} m{sup -3} at 0.1 vol. %.

Niemi, K.; O'Connell, D.; Gans, T. [York Plasma Institute, Department of Physics, University of York, York YO10 5DD (United Kingdom); Oliveira, N. de; Joyeux, D.; Nahon, L. [Synchrotron Soleil, l'Orme des Merisiers, St. Aubin BP 48, 91192 Gif sur Yvette Cedex (France); Booth, J. P. [Laboratoire de Physique des Plasmas-CNRS, Ecole Polytechnique, 91128 Palaiseau (France)

2013-07-15T23:59:59.000Z

Note: This page contains sample records for the topic "atomic absorption spectroscopy" 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

Development of vacuum ultraviolet absorption spectroscopy system for wide measurement range of number density using a dual-tube inductively coupled plasma light source  

SciTech Connect

A vacuum ultraviolet absorption spectroscopy system for a wide measurement range of atomic number densities is developed. Dual-tube inductively coupled plasma was used as a light source. The probe beam profile was optimized for the target number density range by changing the mass flow rate of the inner and outer tubes. This system was verified using cold xenon gas. As a result, the measurement number density range was extended from the conventional two orders to five orders of magnitude.

Kuwahara, Akira; Matsui, Makoto; Yamagiwa, Yoshiki [Department of Mechanical Engineering, Shizuoka University, 3-5-4 Johoku, Naka-ku, Hamamatsu 432-8561, Shizuoka (Japan)

2012-12-15T23:59:59.000Z

42

Acid effects on the measurement of mercury by cold vapor atomic absorption spectrometry  

Science Conference Proceedings (OSTI)

The influence of nitric, hydrochloric and sulfuric acids on the measurement of mercury by cold vapor atomic absorption spectrometry has been investigated. Small pre-reduction peaks associated with the instability of mercury were observed in solutions containing less than or equal to 12.5, tuna using both of these approaches to overcome the interference problem proved to be successful.

Adeloju, S.B.; Mann, T.F.

1987-07-01T23:59:59.000Z

43

Ultra-soft x-ray absorption spectroscopy: A bulk and surface probe of materials  

SciTech Connect

Direct comparisons between surface and bulk of diverse materials can be made by simultaneous electron yield (5 nm depth sensitivity) and fluorescence yield (200 nm) ultra soft x-ray absorption spectroscopy measurements utilizing a rapid sample interchange apparatus. For example the orientations of functional groups have been characterized at and near the surface of a series of model polymeric materials highlighting the chemical and molecular sensitivity of ultra soft x-ray absorption spectroscopy. In addition we discuss a bulk sensitive use of fluorescence yield to non destructively study a buried metal polymer interface. A second bulk sensitive example is the use of fluorescence yield oxygen K near edge x-ray spectroscopy as a method to determine the hole state density of high Tc materials.

Fischer, D.A. [National Institute of Standards and Technology, Gaithersburg, MD (United States); Mitchell, G.E.; Dekoven, B.M. [Dow Chemical Co., Midland, MI (United States); Yeh, A.T.; Gland, J.L. [Michigan Univ., Ann Arbor, MI (United States); Moodenbaugh, A.R. [Brookhaven National Lab., Upton, NY (United States)

1993-06-01T23:59:59.000Z

44

Ultra-soft x-ray absorption spectroscopy: A bulk and surface probe of materials  

SciTech Connect

Direct comparisons between surface and bulk of diverse materials can be made by simultaneous electron yield (5 nm depth sensitivity) and fluorescence yield (200 nm) ultra soft x-ray absorption spectroscopy measurements utilizing a rapid sample interchange apparatus. For example the orientations of functional groups have been characterized at and near the surface of a series of model polymeric materials highlighting the chemical and molecular sensitivity of ultra soft x-ray absorption spectroscopy. In addition we discuss a bulk sensitive use of fluorescence yield to non destructively study a buried metal polymer interface. A second bulk sensitive example is the use of fluorescence yield oxygen K near edge x-ray spectroscopy as a method to determine the hole state density of high Tc materials.

Fischer, D.A. (National Institute of Standards and Technology, Gaithersburg, MD (United States)); Mitchell, G.E.; Dekoven, B.M. (Dow Chemical Co., Midland, MI (United States)); Yeh, A.T.; Gland, J.L. (Michigan Univ., Ann Arbor, MI (United States)); Moodenbaugh, A.R. (Brookhaven National Lab., Upton, NY (United States))

1993-01-01T23:59:59.000Z

45

Temporally resolved characterization of shock-heated foam target with Al absorption spectroscopy for fast electron transport study  

SciTech Connect

The CH foam plasma produced by a laser-driven shock wave has been characterized by a temporally resolved Al 1s-2p absorption spectroscopy technique. A 200 mg/cm{sup 3} foam target with Al dopant was developed for this experiment, which used an OMEGA EP [D. D. Meyerhofer et al., J. Phys.: Conf. Ser. 244, 032010 (2010)] long pulse beam with an energy of 1.2 kJ and 3.5 ns pulselength. The plasma temperatures were inferred with the accuracy of 5 eV from the fits to the measurements using an atomic physics code. The results show that the inferred temperature is sustained at 40-45 eV between 6 and 7 ns and decreases to 25 eV at 8 ns. 2-D radiation hydrodynamic simulations show a good agreement with the measurements. Application of the shock-heated foam plasma platform toward fast electron transport experiments is discussed.

Yabuuchi, T.; Sawada, H.; Wei, M. S.; Beg, F. N. [Center for Energy Research, University of California, San Diego, La Jolla, California 92093 (United States); Regan, S. P.; Anderson, K.; Betti, R. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Hund, J.; Paguio, R. R.; Saito, K. M.; Stephens, R. B. [General Atomics, San Diego, California 92186 (United States); Key, M. H.; Mackinnon, A. J.; McLean, H. S.; Patel, P. K.; Wilks, S. C. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States)

2012-09-15T23:59:59.000Z

46

Light Shift Measurements of Cold Rubidium Atoms using Raman Pump-Probe Spectroscopy.  

E-Print Network (OSTI)

??We have measured light shifts, also known as the A.C. Stark effect, in cold Rubidium atoms using pump-probe spectroscopy. The measurement was made both for… (more)

Souther, Nathan Jon

2009-01-01T23:59:59.000Z

47

Ultra-sensitive surface absorption spectroscopy using sub-wavelength diameter optical fibers  

E-Print Network (OSTI)

The guided modes of sub-wavelength diameter air-clad optical fibers exhibit a pronounced evanescent field. The absorption of particles on the fiber surface is therefore readily detected via the fiber transmission. We show that the resulting absorption for a given surface coverage can be orders of magnitude higher than for conventional surface spectroscopy. As a demonstration, we present measurements on sub-monolayers of 3,4,9,10-perylene-tetracarboxylic dianhydride (PTCDA) molecules at ambient conditions, revealing the agglomeration dynamics on a second to minutes timescale.

F. Warken; E. Vetsch; D. Meschede; M. Sokolowski; A. Rauschenbeutel

2007-01-12T23:59:59.000Z

48

A 2D nanosphere array for atomic spectroscopy M. Romanelli(1)  

E-Print Network (OSTI)

A 2D nanosphere array for atomic spectroscopy M. Romanelli(1) , I. Maurin, P. Todorov(2) , Chia boulevard, 1784 Sofia, Bulgaria (3) permanent address: National Central University, Jung-Li City, Taoyuan medium, such as a photonic crystal, with an atomic gas. Here, we discuss the first step of this program

Paris-Sud XI, Université de

49

High-resolution absorption spectroscopy of the circumgalactic medium of the Milky Way  

E-Print Network (OSTI)

In this article we discuss the importance of high-resolution absorption spectroscopy for our understanding of the distribution and physical nature of the gaseous circumgalactic medium (CGM) that surrounds the Milky Way. Observational and theoretical studies indicate a high complexity of the gas kinematics and an extreme multi-phase nature of the CGM in low-redshift galaxies. High-precision absorption-line measurements of the Milky Way's gas environment thus are essential to explore fundamental parameters of circumgalactic gas in the local Universe, such as mass, chemical composition, and spatial distribution. We shortly review important characteristics of the Milky Way's CGM and discuss recent results from our multi-wavelength observations of the Magellanic Stream. Finally, we discuss the potential of studying the warm-hot phase of the Milky Way's CGM by searching for extremely weak [FeX] l6374.5 and [FeIVX] l5302.9 absorption in optical QSO spectra.

Richter, P; Bekhti, N Ben; Murphy, M T; Bomans, D; Frank, S

2013-01-01T23:59:59.000Z

50

An energy dispersive x-ray absorption spectroscopy beamline, X6A, at NSLS  

Science Conference Proceedings (OSTI)

An energy dispersive x-ray absorption spectroscopy instrument has been built at the X6A beam port of the x-ray ring at the National Synchrotron Light Source (NSLS). This instrument allows the collection of extended x-ray-absorption fine structure and/or x-ray absorption near-edge structure spectra for many elements on the millisecond time scale. The beamline employs a four-point crystal bender and a rectangular Si 220 crystal to access incident energies between 6.5 and 21 keV. Because the polychromator focuses the synchrotron beam to a narrow 100-[mu]m line, this experimental apparatus is ideal for x-ray absorption spectroscopy experiments in special environments such as at high pressures, for [ital in] [ital situ] experiments, and/or for very small samples. In this manuscript we will describe the instrument design and present data with which to evaluate the instrument. This beamline is available through the NSLS user proposal system.

Lee, P.L.; Beno, M.A.; Jennings, G.; Ramanathan, M.; Knapp, G.S.; Huang, K. (Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)); Bai, J. (Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States) Department of Physics, Brooklyn College of CUNY, Brooklyn, New York 11210 (United States)); Montano, P.A. (Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States) Department of Physics, University of Illinois, Chicago, Chicago, Illinois 60680 (United States))

1994-01-01T23:59:59.000Z

51

Microscale X-ray Absorption Spectroscopy on the GSECARS Sector 13 at the APS  

E-Print Network (OSTI)

GeoSoilEnviroCARS (GSECARS) is a national user facility for frontier research in the earth sciences using synchrotrons radiation at the Advanced Photon Source, Argonne National Laboratory. GSECARS provides earth scientists with access to the high-brilliance hard x-rays from this third-generation synchrotrons light source. The research conducted at this facility will advance our knowledge of the composition, structure and properties of earth materials, the processes they control and the processes that produce them. All principal synchrotron-based analytical techniques in demand by earth scientists are being brought to bear on earth science problems: (1) high-pressure/high-temperature crystallography and spectroscopy using the diamond anvil cell; (2) high-pressure/high-temperature crystallography using the large-volume press; (3) powder, single crystal and interface diffraction; (4) x-ray absorption fine structure (XAFS) spectroscopy; (5) x-ray fluorescence microprobe analysis and microspectroscopy; and (6) mic...

Stephen-Sutto

2000-01-01T23:59:59.000Z

52

X-ray absorption spectroscopy studies of electrochemically deposited thin oxide films.  

DOE Green Energy (OSTI)

We have utilized ''in situ'' X-ray Absorption Fine Structure Spectroscopy to investigate the structure and composition of thin oxide films of nickel and iron that have been prepared by electrodeposition on a graphite substrate from aqueous solutions. The films are generally disordered. Structural information has been obtained from the analysis of the data. We also present initial findings on the local structure of heavy metal ions, e.g. Sr and Ce, incorporated into the electrodeposited nickel oxide films. Our results are of importance in a number of technological applications, among them, batteries, fuel cells, electrochromic and ferroelectric materials, corrosion protection, as well as environmental speciation and remediation.

Balasubramanian, M.

1998-06-02T23:59:59.000Z

53

Atomic data for beam-stimulated plasma spectroscopy in fusion plasmas  

SciTech Connect

Injection of high energy atoms into a confined plasma volume is an established diagnostic technique in fusion research. This method strongly depends on the quality of atomic data for charge-exchange recombination spectroscopy (CXRS), motional Stark effect (MSE) and beam-emission spectroscopy (BES). We present some examples of atomic data for CXRS and review the current status of collisional data for parabolic states of hydrogen atoms that are used for accurate MSE modeling. It is shown that the collisional data require knowledge of the excitation density matrix including the off-diagonal matrix elements. The new datasets for transitions between parabolic states are used in an extended collisional-radiative model. The ratios between the {sigma}- and {pi}-components and the beam-emission rate coefficients are calculated in a quasi-steady state approximation. Good agreement with the experimental data from JET is found which points out to strong deviations from the statistical distribution for magnetic sublevels.

Marchuk, O.; Biel, W.; Schlummer, T. [Institute of Energy and Climate Research, Forschungszentrum Juelich, 52425 Juelich (Germany); Ralchenko, Yu. [Quantum Measurement Division, National Institute of Standards and Technology, Gaithersburg, MD 20899-8422 (United States); Schultz, D. R. [Department of Physics, University of North Texas, Denton, TX 76203 (United States); Collaboration: TEXTOR Team

2013-07-11T23:59:59.000Z

54

Local structure of indium oxynitride from x-ray absorption spectroscopy  

SciTech Connect

Synchrotron x-ray absorption near edge structures (XANES) measurements of In L{sub 3} edge is used in conjunction with first principles calculations to characterize rf magnetron sputtered indium oxynitride at different O contents. Good agreement between the measured and the independently calculated spectra are obtained. Calculations show that the XANES spectra of this alloy are sensitive to the coordination numbers of the In atoms, i.e., fourfold for indium nitride-like structures and sixfold for indium oxide-like structures, but not to the substitution of nearest neighbor N by O or vice versa.

T-Thienprasert, J.; Onkaw, D.; Rujirawat, S.; Limpijumnong, S. [School of Physics, Suranaree University of Technology and National Synchrotron Research Center, Nakhon Ratchasima 30000 (Thailand); Nukeaw, J.; Sungthong, A. [Nanotechnology Research Center of KMITL and Department of Applied Physics, King Mongkut' s Institute of Technology Ladkrabang, Bangkok 10520 (Thailand); Porntheeraphat, S. [Thai Microelectronics Center, National Electronics and Computer Technology Center, Pathumthani 12120 (Thailand); Singkarat, S. [Fast Neutron Research Facility, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand)

2008-08-04T23:59:59.000Z

55

A Fern Fatale - X-ray Absorption Spectroscopy Imaging an Arsenic-Loving  

NLE Websites -- All DOE Office Websites (Extended Search)

Fern Fatale - X-ray Absorption Spectroscopy Imaging of an Arsenic-Loving Fern Fatale - X-ray Absorption Spectroscopy Imaging of an Arsenic-Loving Fern For many people, arsenic is synonymous with poison, so it is perhaps a surprise that some plants, such as the fern Pteris vittata (Figure 1) seem to quite deliberately accumulate large amounts of it. What is more, the plant converts it to the most toxic inorganic form known. How does it do this? First some background; while there is some evidence that arsenic is required for health [1], this is debatable. On the other hand, the poisonous nature of arsenic compounds was understood by the ancient Greeks and Romans, and it has been used throughout history as a homicidal and suicidal agent. It is found in two environmentally common oxy acids; arsenous acid (H3AsO3), and arsenic acid (H3AsO4), whose salts are known as arsenites and arsenates, respectively. Of these, the trivalent arsenic species are the most toxic. The infamous agent of murder is arsenic trioxide (white arsenic or As2O3), which is simply the (reputedly tasteless) anhydride of arsenous acid.

56

COSMOLOGICAL EVOLUTION OF ATOMIC GAS AND IMPLICATIONS FOR 21 cm H I ABSORPTION  

SciTech Connect

Galaxy disks are shown to contain a significant population of atomic clouds of 100 pc linear size which are self-opaque in the 21 cm transition. These objects have H I column densities as high as 10{sup 23} cm{sup -2} and contribute to a global opacity correction factor of 1.34 {+-} 0.05 that applies to the integrated 21 cm emission to obtain a total H I mass estimate. High-resolution, opacity-corrected images of the nearest external galaxies have been used to form a robust redshift zero distribution function of H I, f(N{sub HI}, X, z = 0), the probability of encountering a specific H I column density along random lines of sight per unit comoving distance. This is contrasted with previously published determinations of f(N{sub HI}, X) at z = 1 and 3. A systematic decline of moderate column density (18 < log(N{sub H)} < 21) H I is observed with decreasing redshift that corresponds to a decline in surface area of such gas by a factor of five since z = 3. The number of equivalent Damped Lyman Alpha absorbers (log(N{sub HI})>20.3) has also declined systematically over this redshift interval by a similar amount, while the cosmological mass density in such systems has declined by only a factor of two to its current, opacity-corrected value of {Omega}{sup DLA}{sub HI}(z = 0) = 5.4 {+-} 0.9 Multiplication-Sign 10{sup -4}. We utilize the tight but strongly nonlinear dependence of 21 cm absorption opacity on column density at z = 0 to transform our high-resolution H I images into ones of 21 cm absorption opacity. These images are used to calculate distribution and pathlength functions of integrated 21 cm opacity. We suggest that that this z = 0 calibration may also apply at higher redshift. In this case, the incidence of deep 21 cm absorption systems is predicted to show very little evolution with redshift, while that of faint absorbers should decline by a factor of 5 between z = 3 and the present. We explicitly consider the effects of H I absorption against background sources that are extended relative to the 100 pc intervening absorber size scale. Extended background sources result in dramatically altered distribution and pathlength functions which are insensitive to the predicted redshift evolution. Future surveys of 21 cm absorption will require very high angular resolution, of about 15 mas, for their unambiguous interpretation.

Braun, Robert, E-mail: Robert.Braun@csiro.au [CSIRO Astronomy and Space Science, P.O. Box 76, Epping, NSW 1710 (Australia)

2012-04-10T23:59:59.000Z

57

X-ray Absorption Spectroscopy Beamline at the Siam Photon Laboratory  

SciTech Connect

A bending magnet beamline has been constructed and commissioned for x-ray absorption spectroscopy (XAS) at the Siam Photon Laboratory. The photon energy is tunable from 1830 eV to 8000 eV using a Lemmonier-type, fixed-exit double crystal monochromator equipped with InSb(111), Si(111), Ge(220) crystals. Elemental K-edges are then accessible from silicon to iron. A series of low conductance vacuum tubes has been designed and installed between the pumping chambers in the front end to obtain the proper pressure difference between the upstream and the downstream of the front end. Thus lower-energy photons, around K-edges of silicon, phosphorous, and sulfur, can be delivered to the experimental XAS station without being absorbed by a window. In this report, the design of the beamline is described. The commissioning results including the measured photon flux at sample and experimental XAS spectra are presented.

Klysubun, Wantana; Tarawarakarn, Pongjakr; Sombunchoo, Panidtha; Klinkhieo, Supat; Chaiprapa, Jitrin [National Synchrotron Research Center, 111 University Ave., Muang District, Nakhon Ratchasima 30000 (Thailand); Songsiriritthigul, Prayoon [National Synchrotron Research Center, 111 University Ave., Muang District, Nakhon Ratchasima 30000 (Thailand); School of Physics, Suranaree University of Technology, Nakhon Ratchasima 30000 (Thailand)

2007-01-19T23:59:59.000Z

58

Time-resolved broadband cavity-enhanced absorption spectroscopy for chemical kinetics.  

SciTech Connect

Experimental measurements of elementary reaction rate coefficients and product branching ratios are essential to our understanding of many fundamentally important processes in Combustion Chemistry. However, such measurements are often impossible because of a lack of adequate detection techniques. Some of the largest gaps in our knowledge concern some of the most important radical species, because their short lifetimes and low steady-state concentrations make them particularly difficult to detect. To address this challenge, we propose a novel general detection method for gas-phase chemical kinetics: time-resolved broadband cavity-enhanced absorption spectroscopy (TR-BB-CEAS). This all-optical, non-intrusive, multiplexed method enables sensitive direct probing of transient reaction intermediates in a simple, inexpensive, and robust experimental package.

Sheps, Leonid; Chandler, David W.

2013-04-01T23:59:59.000Z

59

Laser spectroscopy of the antiprotonic helium atom – its energy levels and state lifetimes  

E-Print Network (OSTI)

The antiprotonic atom is a three-body exotic system consisting of an antiproton, an electron and a helium nucleus. Its surprising longevity was found and has been studied for more than 10 years. In this work, transition energies and lifetimes of this exotic atom were systematically studied by using the antiproton beam of AD(Antiproton Decelerator) facility at CERN, with an RFQ antiproton decelerator, a narrow-bandwidth laser, Cerenkov counters with fast-response photomultiplier tubes, and cryogenic helium target systems. Thirteen transition energies were determined with precisions of better than 200 ppb by a laser spectroscopy method, together with the elimination of the shift effect caused by collisions with surrounding atoms. Fifteen lifetimes (decay rates) of short-lived states were determined from the time distributions of the antiproton-annihilation signals and the resonance widths of the atomic spectral lines. The relation between the magnitude of the decay rates and the transition multipolarity was inv...

Hidetoshi, Yamaguchi

2003-01-01T23:59:59.000Z

60

Absorption Spectroscopy in Hollow-Glass Waveguides Using Infrared Diode Lasers[4817-25  

Science Conference Proceedings (OSTI)

Near- and mid-infrared diode lasers combined with flexible, hollow waveguides hold the promise of light weight, field portable, fast response gas sensors. The advantages of using the waveguides compared to White or Herriott multireflection cells include a small gas volume, a high photon fill factor in the waveguide, which increases molecule-light interactions, and reduction or elimination of optical fringing, which usually sets the practical limit of detectivity in absorption spectroscopy. Though hollow waveguides have been commercially available for several years, relatively few results have been reported in the literature. We present here results from our laboratory where we have injected infrared laser light into straight and coiled lengths of hollow waveguides and performed direct and wavelength modulated absorption spectroscopy on nitrous oxide, ethylene, and nitric oxide. Using a 1 mm bore, 3 meter long coiled waveguide coated for the near infrared, nitrous oxide transitions near 6595 cm-1 were observed under flowing conditions. Signal-to-noise ratios on the order of 1500:1 with RMS noise equal to 2 X 10-5 were measured. In the mid-infrared light from either a 10.1 or 5.3 micron lead salt diode laser was injected into a three meter length of 1 mm bore hollow waveguide coated for the mid-infrared. The waveguide was coiled with one loop at a diameter of 52 cm. Ethylene transitions were observed in the vicinity of 985 cm-1 with a static fill of 0.2 Torr of pure ethylene in the waveguide and nitric oxide transitions were observed in the vicinity of 1906 cm-1 using either a flow or a static fill of 1 ppm NO in nitrogen. In direct absorption the NO transitions are observed to have a signal-to-noise of approximately 5:1 for transitions with absorbances on the order of 10-3. Using wavelength modulated techniques the signal-to-noise ratio improves at least an order of magnitude. These encouraging results indicate that waveguides can be used for in situ gas monitoring.

Blake, Thomas A. (BATTELLE (PACIFIC NW LAB)); Kelly, James F. (BATTELLE (PACIFIC NW LAB)); Stewart, Timothy L. (BATTELLE (PACIFIC NW LAB)); Hartman, John S. (BATTELLE (PACIFIC NW LAB)); Sharpe, Steven W. (BATTELLE (PACIFIC NW LAB)); Sams, Robert L. (BATTELLE (PACIFIC NW LAB)); Alan Fried

2002-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "atomic absorption spectroscopy" 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

REACTION KINETICS AND X-RAY ABSORPTION SPECTROSCOPY STUDIES OF YTTRIUM CONTAINING METAL HYDRIDE ELECTRODES  

DOE Green Energy (OSTI)

This was a study of electrode degradation mechanisms and the reaction kinetics of LaNi{sub 4.7}Sn{sub 0.3}, La{sub (1{minus}x)}, (x = 0.1, 0.2, and 0.3) and La{sub 0.7}Y{sub 0.3}Ni{sub 4.6}Sn{sub 0.3}Co{sub 0.1} metal hydride electrodes. Alloy characterization included x-ray diffraction (XRD), x-ray absorption (XAS), hydrogen absorption in a Sieverts apparatus, and electrochemical cycling of alloy electrodes. The atomic volume of H was determined for two of the alloys. Electrochemical kinetic measurements were made using steady state galvanostatic measurements, galvanodynamic sweep, and electrochemical impedance techniques. XAS was used to examine the degree of corrosion of the alloys with cycling. Alloying with Y decreased the corrosion rate. The results are consistent with corrosion inhibition by a Y containing passive film. The increase in the kinetics of the hydrogen oxidation reaction (HOR) with increasing depth of discharge was much greater on the Y containing alloys. This may be due to the dehydriding of the catalytic species on the surface of the metal hydride particles.

TICIANELLI,E.A.; MUKERJEE,S.; MCBREEN,J.; ADZIC,G.D.; JOHNSON,J.R.; REILLY,J.J.

1998-11-01T23:59:59.000Z

62

Understanding Electrocatalytic Pathways in Low and Medium Temperature Fuel Cells: Synchrotron-based In Situ X-Ray Absorption Spectroscopy  

DOE Green Energy (OSTI)

Over the last few decades, researchers have made significant developments in producing more advanced electrocatalytic materials for power generation applications. For example, traditional fuel cell catalysts often involve high-priced precious metals such as Pt. However, in order for fuel cells to become commercially viable, there is a need to reduce or completely remove precious metal altogether. As a result, a myriad of novel, unconventional materials have been explored such as chalcogenides, porphyrins, and organic-metal-macrocycles for low/medium temperature fuel cells as well as enzymatic and microbial fuel cells. As these materials increasingly become more complex, researchers often find themselves in search of new characterization methods, especially those which are allow in situ and operando measurements with element specificity. One such method that has received much attention for analysis of electrocatalytic materials is X-ray absorption spectroscopy (XAS). XAS is an element specific, core level absorption technique which yields structural and electronic information. As a core electron method, XAS requires an extremely bright source, hence a synchrotron. The resulting intensity of synchrotron radiation allow for experiments to be conducted in situ, under electrochemically relevant conditions. Although a bulk-averaging technique requiring rigorous mathematical manipulation, XAS has the added benefit that it can probe materials which possess no long range order. This makes it ideal to characterize nano-scale electrocatalysts. XAS experiments are conducted by ramping the X-ray photon energy while measuring absorption of the incident beam the sample or by counting fluorescent photons released from a sample due to subsequent relaxation. Absorption mode XAS follows the Beer-Lambert Law, {mu}x = log(I{sub 0}/I{sub t}) (1) where {mu} is the absorption coefficient, x is the sample thickness and I{sub 0} and I{sub t} are the intensities of the incident and transmission beams respectively. When the energy of the incident X-rays exceed the electron binding energy (E{sub 0}) of the element under investigation, the electron is ejected from the core to available excited states in the form of a photoelectron with kinetic energy: E{sub k} = h? - E{sub 0} (2) with, E{sub k} being the kinetic energy of the released photoelectron and h? the energy of the incident beam. In general, the X-ray absorption spectrum is broken down into two distinct energy regions: the X-ray absorption near-edge structure or XANES (-50eV {le} E{sub 0} {le} 50eV) and the extended X-ray absorption fine-structure or EXAFS (50eV {le} E{sub 0} {le} {approx}1000eV). The XANES region is dominated by low-energy photoelectrons which undergo multiple scattering events. As such, it can reveal information about oxidation state, local symmetry, electronic structure, and the extent of oxidation of a material. Due to this complex multiple scattering, there is no simple XANES equation to describe it quantitatively. However, recent advancements in computers and the evolution of numerical methods such as the FEFF code have made possible reliable XANES simulations. Photoelectrons in the EXAFS region have high enough E{sub k} to undergo primarily single back-scattering events. These back-scattered photoelectrons interfere with the outgoing photoelectrons, causing the oscillations in the absorption spectrum. Using the previously developed EXAFS equations it is now possible to model EXAFS data to determine coordination numbers, bond distances, and mean-square disorder (commonly referred to as Debye-Waller factor). EXAFS data is often shown by Fourier Transforming KSpace into distance, r, space where the total magnitude is plotted against the radial coordinates. This allow for easy qualitative comparison of samples. Employing EXAFS on nanoscale materials has the added advantage that it can quantitatively illustrate changes in atom-atom coordination, which can be related to particle size or morphology. Overall this technique enables the measurement of both bulk and surface adsor

Mukerjee, S.; Ziegelbauer, J; Arruda, T; Ramaker, D; Shyam, B

2008-01-01T23:59:59.000Z

63

Atomic Spectroscopy  

Science Conference Proceedings (OSTI)

... The ground-state electron configurations of elements heavier than neon are shortened in the table by using rare-gas element symbols in brackets ...

2013-03-13T23:59:59.000Z

64

A distributed atomic physics database and modeling system for plasma spectroscopy  

SciTech Connect

We are undertaking to develop a set of computational capabilities which will facilitate the access, manipulation, and understanding of atomic data in calculations of x-ray spectral modeling. In this present limited description we will emphasize the objectives for this work, the design philosophy, and aspects of the atomic database, as a more complete description of this work is available. The project is referred to as the Plasma Spectroscopy Initiative; the computing environment is called PSI, or the ``PSI shell`` since the primary interface resembles a UNIX shell window. The working group consists of researchers in the fields of x-ray plasma spectroscopy, atomic physics, plasma diagnostics, line shape theory, astrophysics, and computer science. To date, our focus has been to develop the software foundations, including the atomic physics database, and to apply the existing capabilities to a range of working problems. These problems have been chosen in part to exercise the overall design and implementation of the shell. For successful implementation the final design must have great flexibility since our goal is not simply to satisfy our interests but to vide a tool of general use to the community.

Nash, J.K.; Liedahl, D.; Chen, M.H.; Iglesias, C.A.; Lee, R.W. [Lawrence Livermore National Lab., CA (United States); Salter, J.M. [South Gosforth Computer Systems, Newcastle upon Tyne (United Kingdom)

1995-08-01T23:59:59.000Z

65

Understanding Sulfur Poisoning and Regeneration of Nickel Biomass Conditioning Catalysts using X-Ray Absorption Spectroscopy  

Science Conference Proceedings (OSTI)

The production of biofuels can proceed via a biomass gasification to produce syngas, which can then undergo catalytic conditioning and reforming reactions prior to being sent to a fuel synthesis reactor. Catalysts used for biomass conditioning are plagued by short lifetimes which are a result of, among other things, poisoning. Syngas produced from biomass gasification may contain between 30-300 ppm H2S, depending on the feedstock and gasification conditions, and H2S is a key catalyst poison. In order to overcome catalyst poisoning, either an H2S-tolerant catalyst or an efficient regeneration protocol should be employed. In this study, sulfur K-edge X-ray absorption near edge spectroscopy (XANES) was used to monitor sulfur species on spent catalyst samples and the transformation of these species from sulfides to sulfates during steam and air regeneration on a Ni/Mg/K/Al2O3 catalyst used to condition biomass-derived syngas. Additionally, nickel K-edge EXAFS and XANES are used to examine the state of nickel species on the catalysts. Post-reaction samples showed the presence of sulfides on the H2S-poisoned nickel catalyst and although some gaseous sulfur species were observed to leave the catalyst bed during regeneration, sulfur remained on the catalyst and a transformation from sulfides to sulfates was observed. The subsequent H2 reduction led to a partial reduction of sulfates back to sulfides. A proposed reaction sequence is presented and recommended regeneration strategies are discussed.

Yung, M. M.; Cheah, S.; Kuhn, J. N.

2013-01-01T23:59:59.000Z

66

Determination of mercury distribution inside spent compact fluorescent lamps by atomic absorption spectrometry  

Science Conference Proceedings (OSTI)

Highlights: Black-Right-Pointing-Pointer New treatments for CFL are required considering the aim of Directive 202/96/CE. Black-Right-Pointing-Pointer It is shown that most of the mercury introduced into a CFL is in the phosphor powder. Black-Right-Pointing-Pointer Experimental conditions for microwave-assisted sample digestion followed by AAS measurements are described. Black-Right-Pointing-Pointer By washing the glass it is possible to reduce the concentration below legal limits. - Abstract: In this study, spent compact fluorescent lamps were characterized to determine the distribution of mercury. The procedure used in this research allowed mercury to be extracted in the vapor phase, from the phosphor powder, and the glass matrix. Mercury concentration in the three phases was determined by the method known as cold vapor atomic absorption spectrometry. Median values obtained in the study showed that a compact fluorescent lamp contained 24.52 {+-} 0.4 ppb of mercury in the vapor phase, 204.16 {+-} 8.9 ppb of mercury in the phosphor powder, and 18.74 {+-} 0.5 ppb of mercury in the glass matrix. There are differences in mercury concentration between the lamps since the year of manufacture or the hours of operation affect both mercury content and its distribution. The 85.76% of the mercury introduced into a compact fluorescent lamp becomes a component of the phosphor powder, while more than 13.66% is diffused through the glass matrix. By washing and eliminating all phosphor powder attached to the glass surface it is possible to classified the glass as a non-hazardous waste.

Rey-Raap, Natalia [Departamento de Ingenieria Mecanica y Construccion, Universitat Jaume I de Castellon, Av. de Vicent Sos Baynat s/n, 12071 Castellon de la Plana, Espana (Spain); Gallardo, Antonio, E-mail: gallardo@emc.uji.es [Departamento de Ingenieria Mecanica y Construccion, Universitat Jaume I de Castellon, Av. de Vicent Sos Baynat s/n, 12071 Castellon de la Plana, Espana (Spain)

2012-05-15T23:59:59.000Z

67

Atomic physics studies of highly charged ions on tokamaks using x-ray spectroscopy  

SciTech Connect

An overview is given of atomic physics issues which have been studied on tokamaks with the help resolution x-ray spectroscopy. The issues include the testing of model calculations predicting the excitation of line radiation, the determination of rate coefficients, and accurate atomic structure measurements. Recent research has focussed primarily on highly charged heliumlike (22 less than or equal to Z less than or equal to 28) and neonlike (34 less than or equal to Z less than or equal to 63) ions, and results are presented from measurements on the PLT and TFTR tokamaks. Many of the measurements have been aided by improved instrumental design and new measuring techniques. Remarkable agreement has been found between measurements and theory in most cases. However, in this review those areas are stressed where agreement is worst and where further investigations are needed. 19 refs., 13 figs., 2 tabs.

Beiersdorfer, P.; von Goeler, S.; Bitter, M.; Hill, K.W.

1989-07-01T23:59:59.000Z

68

Atomic-Scale Imaging and Spectroscopy for In Situ Liquid Scanning Transmission Electron Microscopy  

Science Conference Proceedings (OSTI)

Observation of growth, synthesis, dynamics and electrochemical reactions in the liquid state is an important yet largely unstudied aspect of nanotechnology. The only techniques that can potentially provide the insights necessary to advance our understanding of these mechanisms is simultaneous atomic-scale imaging and quantitative chemical analysis (through spectroscopy) under environmental conditions in the transmission electron microscope (TEM). In this study we describe the experimental and technical conditions necessary to obtain electron energy loss (EEL) spectra from a nanoparticle in colloidal suspension using aberration corrected scanning transmission electron microscopy (STEM) combined with the environmental liquid stage. At a fluid path length below 400 nm, atomic resolution images can be obtained and simultaneous compositional analysis can be achieved. We show that EEL spectroscopy can be used to quantify the total fluid path length around the nanoparticle, and demonstrate characteristic core-loss signals from the suspended nanoparticles can be resolved and analyzed to provide information on the local interfacial chemistry with the surrounding environment. The combined approach using aberration corrected STEM and EEL spectra with the in situ fluid stage demonstrates a plenary platform for detailed investigations of solution based catalysis and biological research.

Jungjohann, K. L.; Evans, James E.; Aguiar, Jeff; Arslan, Ilke; Browning, Nigel D.

2012-06-04T23:59:59.000Z

69

On-Site Calibration for High Precision Measurements of Water Vapor Isotope Ratios Using Off-Axis Cavity-Enhanced Absorption Spectroscopy  

Science Conference Proceedings (OSTI)

Stable isotope ratio measurements of atmospheric water vapor (?18Ov and ?2Hv) are scarce relative to those in precipitation. This limitation is rapidly changing due to advances in absorption spectroscopy technology and the development of ...

Joshua Rambo; Chun-Ta Lai; James Farlin; Matt Schroeder; Ken Bible

2011-11-01T23:59:59.000Z

70

In situ X-ray absorption spectroscopy--A probe of cathode materials...  

NLE Websites -- All DOE Office Websites (Extended Search)

2006 Authors Deb, Aniruddha, and Elton J. Cairns Journal Fluid Phase Equilibria Volume 241 Pagination 4-19 Keywords absorption-fine-structure, in situ electrochemistry,...

71

Studies of Cu(II) in soil by X-ray absorption spectroscopy A. I. Frenkel1 and G. V. Korshin2  

E-Print Network (OSTI)

Studies of Cu(II) in soil by X-ray absorption spectroscopy A. I. Frenkel1 and G. V. Korshin2 1. Frenkel, A. I. and Korshin, G. V. 2001. Studies of Cu(II) in soil by X-ray absorption spectroscopy. Can. J. Soil Sci. 81: 271­276. Based on original data for copper, this paper evaluates the use and advantages

Frenkel, Anatoly

72

USE OF ZEEMAN ATOMIC ABSORPTION SPECTROSCOPY FOR THE MEASUREMENT OF MERCURY IN OIL SHALE GASES  

E-Print Network (OSTI)

and R. E. Poulson. Mercury Emissions From A Simulated In-for the Measurement of Mercury in Oil Shale Gases D. GirvinJFOR THE MEASUREMENT OF MERCURY IN OIL SHALE GASES D. C.

Girvin, D.G.

2011-01-01T23:59:59.000Z

73

SPECIES DETERMINATION OF ORGANOMETALLIC COMPOUNDS USING ZEEMAN ATOMIC ABSORPTION SPECTROSCOPY WITH LIQUID CHROMATOGRAPHY  

E-Print Network (OSTI)

T. Hadeishi and R. D. McLaughlin, Science, 174, 404 (1971).Koizumi, Tetsuo Hadeishi and Ralph McLaughlin January 1978Hadeishi and Ralph McLaughlin Lawrence Berkeley Laboratory

Koizumi, H.

2011-01-01T23:59:59.000Z

74

USE OF ZEEMAN ATOMIC ABSORPTION SPECTROSCOPY FOR THE MEASUREMENT OF MERCURY IN OIL SHALE GASES  

E-Print Network (OSTI)

Minor Elements in Oil Shale and Oil-Shale Products. LERC RIChemistry of Tar Sands and Oil Shale, ACS, New Orleans.Constituent Analysis of Oil Shale and Solvent-Refined Coal

Girvin, D.G.

2011-01-01T23:59:59.000Z

75

USE OF ZEEMAN ATOMIC ABSORPTION SPECTROSCOPY FOR THE MEASUREMENT OF MERCURY IN OIL SHALE GASES  

E-Print Network (OSTI)

W. A. Robb, and T. J. Spedding. Minor Elements in Oil Shaleand Oil-Shale Products. LERC RI 77-1, 1977. Bertine, K. K.From A Simulated In-Situ Oil Shale Retort. In: Procedings of

Girvin, D.G.

2011-01-01T23:59:59.000Z

76

USE OF ZEEMAN ATOMIC ABSORPTION SPECTROSCOPY FOR THE MEASUREMENT OF MERCURY IN OIL SHALE GASES  

E-Print Network (OSTI)

A. Robb, and T. J. Spedding. Minor Elements in Oil Shale andOil-Shale Products. LERC RI 77-1, 1977. Bertine, K. K. andFrom A Simulated In-Situ Oil Shale Retort. In: Procedings of

Girvin, D.G.

2011-01-01T23:59:59.000Z

77

Diagnosing the plasma nonuniformity in an iron opacity experiment by spatially resolved Al 1s-2p absorption spectroscopy  

Science Conference Proceedings (OSTI)

Generating a well-characterized hot-dense sample is of great importance to high quality opacity measurements. In this paper, we report on an experimental investigation of the plasma nonuniformity in a radiatively heated iron opacity sample by spatially resolved Al 1s-2p absorption spectroscopy. The iron sample was tamped by plastic at both sides and was heated by thermal x-ray radiation generated in a gold Hohlraum, and an Al layer attached to it was used as a tracer for temperature diagnosis. Spatially resolved 1s-2p transition absorption spectra of the Al tracer were measured by the technique of point-projection-spectroscopy, and temperatures in the sample were obtained by comparing the measured spectra with detailed-term-accounting model calculations, with the density of the sample deduced using a combination of side-on radiography and radiative hydrodynamic simulation. The results showed the existence of axial temperature nonuniformity in the sample, and these temperature variations have been used to explain the shift of iron 2p-3d transition absorption feature along the axial direction of the Hohlraum used to heat the sample successfully.

Zhang Xiaoding [CAS Key Laboratory of Basic Plasma Physics and Department of Modern Physics of University of Science and Technology of China, Hefei 230026 (China); Research Center of Laser Fusion, P. O. Box 919-986, Mianyang 621900 (China); Zhang Jiyan; Zhao Yang; Xiong Gang; Yang Guohong; Yang Jiamin [Research Center of Laser Fusion, P. O. Box 919-986, Mianyang 621900 (China); Zhao Bin; Zheng Jian [CAS Key Laboratory of Basic Plasma Physics and Department of Modern Physics of University of Science and Technology of China, Hefei 230026 (China)

2012-12-15T23:59:59.000Z

78

Soft x-ray absorption and photoemission spectroscopy study of superoxide KO2 J.-S. Kang,* D. H. Kim, and J. H. Hwang  

E-Print Network (OSTI)

Soft x-ray absorption and photoemission spectroscopy study of superoxide KO2 J.-S. Kang,* D. H. Kim of superoxide KO2 was investigated by employing soft x-ray absorption spectros- copy XAS and core cooling, O2 - molecular bond axes seem to tilt to have a lower crystal monoclinic symme- try. By lowering

Min, Byung Il

79

Particle size effect of hydride formation and surface hydrogen absorption of nanosized palladium catalysts : L{sub 3} edge vs K edge x-ray absorption spectroscopy.  

Science Conference Proceedings (OSTI)

The particle size effect on the formation of palladium hydride and on surface hydrogen adsorption was studied at room temperature using in situ X-ray absorption spectroscopy at the Pd K and L{sub 3} edges. Hydride formation was indirectly observed by lattice expansion in Pd K edge XANES spectra and by EXAFS analysis. Hydride formation was directly detected in the L{sub 3} edge spectra. A characteristic spectral feature caused by the formation of a Pd-H antibonding state showed strong particle size dependence. The L{sub 3} edge spectra were reproduced using full multiple scattering analysis and density of state calculations, and the contributions of bulk absorbed and surface hydrogen to the XANES spectra could be distinguished. The ratio of hydrogen on the surface versus that in the bulk increased with decreasing particle size, and smaller particles dissolved less hydrogen.

Tew, M. W.; Miller, J. T.; van Bokhoven, J. A. (Chemical Sciences and Engineering Division); ( SUF-USR); (ETH Zurich)

2009-08-01T23:59:59.000Z

80

Development of laser optogalvanic spectroscopy as a probe of alkali atoms in an MHD environment  

DOE Green Energy (OSTI)

Application of Laser Optogalvanic Spectroscopy (LOGS) to MHD combustion systems requires selection of an appropriate alkali atom electronic transition to monitor. These studies suggest that in MHD combustion systems, it is desirable to use cesium, which occurs as an impurity in potassium compounds, as a surrogate for potassium rather than to directly monitor potassium in order to obtain reliable determinations of seed concentration. Studies were also performed to investigate the effect of electrode corrosion on the normalized LOGS signal intensity at a fixed wavelength (578.238 nm). During six-hour experiments in a near-stoichiometric flame, the normalized LOGS signal intensity decreased by 40-50% for a -960 V rod electrode and by 10-20% for a -500 V rod electrode. These changes are attributed to buildup of an oxide coating on the electrode, reducing the collection efficiency of the electrode.

Monts, D.L.; Qian, S.; Cook, R.L.; Shepard, W.S.

1995-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "atomic absorption spectroscopy" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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81

Multielement analysis of geologic materials by inductively coupled plasma-atomic emission spectroscopy  

DOE Green Energy (OSTI)

Atomic emission spectroscopy using an inductively coupled plasma (ICP) source permits the rapid acquisition of multielement geochemical data from a wide variety of geologic materials. Rocks or other solid samples are taken into solution with a four acid digestion procedure and introduced directly into the plasma; fluid samples are acidified or analyzed directly. The entire process is computer-controlled, fully-automated, and requires less than five minutes per sample for quantitative determination of 37 elements. The procedures and instrumentation employed at the ESL for multielement ICP analysis of geologic materials are described and these are intended as a guide for evaluating analytic results reported from this laboratory. The quality of geochemical data can be characterized by precision, limits of quantitative determination, and accuracy. Precision values are a measure of the repeatability of analyses. In general, major element and analyses have precision of better than 5% and trace elements of better than 10% of the amount present. (MHR)

Christensen, O.D.; Kroneman, R.L.; Capuano, R.M.

1980-03-01T23:59:59.000Z

82

Design of a continuous-flow reactor for in situ x-ray absorption spectroscopy of solids in supercritical fluids  

Science Conference Proceedings (OSTI)

This paper presents the design and performance of a novel high-temperature and high-pressure continuous-flow reactor, which allows for x-ray absorption spectroscopy or diffraction in supercritical water and other fluids under high pressure and temperature. The in situ cell consists of a tube of sintered, polycrystalline aluminum nitride, which is tolerant to corrosive chemical media, and was designed to be stable at temperatures up to 500 deg. C and pressures up to 30 MPa. The performance of the reactor is demonstrated by the measurement of extended x-ray absorption fine structure spectra of a carbon-supported ruthenium catalyst during the continuous hydrothermal gasification of ethanol in supercritical water at 400 deg. C and 24 MPa.

Dreher, M.; De Boni, E.; Nachtegaal, M.; Wambach, J.; Vogel, F. [Paul Scherrer Institut, 5232 Villigen PSI (Switzerland)

2012-05-15T23:59:59.000Z

83

Aspects of Graviton Detection: Graviton Emission and Absorption by Atomic Hydrogen  

E-Print Network (OSTI)

Graviton absorption cross sections and emission rates for hydrogen are calculated by both semi-classical and field theoretic methods. We point out several mistakes in the literature concerning spontaneous emission of gravitons and related phenomena, some of which are due to a subtle issue concerning gauge invariance of the linearized interaction Hamiltonian.

Stephen Boughn; Tony Rothman

2006-05-09T23:59:59.000Z

84

Design and Operation of a High Pressure Reaction Cell for in situ X-ray Absorption Spectroscopy  

DOE Green Energy (OSTI)

X-ray absorption spectroscopy measurements of catalytic reactions have been instrumental in advancing the understanding of catalytic processes. These measurements require an in situ catalysis reaction cell with unique properties. Here we describe the design and initial operation of an in situ/operando catalysis reaction cell for transmission X-ray absorption spectroscopy measurements. The cell is designed: to be an ideal catalytic reactor with no mass transfer effects; to give the same conversion and selectivity under similar space velocities as standard laboratory micro-reactors; to be operational temperatures up to 600 {sup o}C and pressures up to 14 bar; to be X-ray transparent allowing XAS measurement to be collected in transmission for all elements with Z {>=} 23 (vanadium K-edge at 5.5 keV); to measure the actual catalyst bed temperature; to not use o-ring seals, or water cooling; to be robust, compact, easy to assemble, and use, and relatively low cost to produce. The heart of the cell is fabricated from an X-ray transparent beryllium tube that forms a plug flow reactor. XAFS data recorded during the reduction of a Re/{gamma}-A{sub 2}O{sub 3} catalyst as a function of hydrogen pressure from 0.05 to 8 bar, and from a Pt-Sn/{gamma}-A{sub 2}O{sub 3} catalyst during n-heptane reforming are given as initial examples of the versatility of the reactor.

Bare,S.; Yang, N.; Kelly, S.; Mickelson, G.; Modica, F.

2007-01-01T23:59:59.000Z

85

Atomic-Scale Chemical Imaging via Combination of Scanning Tunneling and Electron Energy Loss Spectroscopies  

E-Print Network (OSTI)

Atomic-Scale Chemical Imaging via Combination of Scanning Tunneling and Electron Energy Loss visualization of chemical reaction pathways to provide mechanistic understanding for catalytically important systems at atomic level Develop atomically resolved chemical imaging platform via combination of low

86

Measurement of H and H/sub 2/ populations in-situ in a low-temperature plasma by vacuum-ultraviolet laser-absorption spectroscopy  

DOE Green Energy (OSTI)

A new technique, vacuum-ultraviolet laser-absorption spectroscopy, has been developed to quantitatively determine the absolute density of H and H/sub 2/ within a plasma. The technique is particularly well suited to measurement in a plasma, where high charged particle and photon background complicate other methods of detection. The high selectivity and sensitivity of the technique allows for the measurement of the rotational-vibrational state distribution of H/sub 2/ as well as the translational temperature of the atoms and molecules. The technique has been used to study both pulsed and continuous H/sup /minus// ion-source plasma discharges. H/sub 2/ state distributions in a multicusp ''volume'' H/sup /minus// ion- source plasma show a high degree of internal excitation, with levels up to v = 5 and J = 8 being observed. The method is applicable for a very wide range of plasma conditions. Emission measurements from excited states of H are also reported. 17 refs., 9 figs.

Schlachter, A.S.; Young, A.T.; Stutzin, G.C.; Stearns, J.W.; Doebele, H.G.; Leung, K.N.; Kunkel, W.B.

1988-12-01T23:59:59.000Z

87

Microsoft PowerPoint - SpectroscopyTechniques_EXAFS  

NLE Websites -- All DOE Office Websites (Extended Search)

X-ray Absorption Fine Structure Spectroscopy (EXAFS) X-ray Absorption Fine Structure Spectroscopy (EXAFS) * Provides details on how x rays are absorbed by an atom at energies near X18A,B,X19A * Provides details on how x-rays are absorbed by an atom at energies near and above the core-level binding energies of that atom * Gives the modulation of an atom's x-ray absorption probability due to the chemical and physical state of the atom * Especially sensitive to the formal oxidation state, coordination chemistry, and the distances, coordination numbers, and species of the atoms immediately surrounding the selected element * Provides a practical, and relatively simple, way to determine the chemical state and local atomic structure for a selected atomic species

88

Assessment of Aided Phytostabilization of Copper-Contaminated Soil by X-ray Absorption Spectroscopy and Chemical Extractions  

SciTech Connect

Field plots were established at a timber treatment site to evaluate remediation of Cu contaminated topsoils with aided phytostabilization. Soil containing 2600 mg kg{sup -1} Cu was amended with a combination of 5 wt% compost and 2 wt% iron grit, and vegetated. Sequential extraction was combined with extended X-ray absorption fine structure (EXAFS) spectroscopy to correlate changes in Cu distribution across five fractions with changes in the predominant Cu compounds two years after treatment in parallel treated and untreated field plots. Exchangeable Cu dominated untreated soil, most likely as Cu(II) species non-specifically bound to natural organic matter. The EXAFS spectroscopic results are consistent with the sequential extraction results, which show a major shift in Cu distribution as a result of soil treatment to the fraction bound to poorly crystalline Fe oxyhydroxides forming binuclear inner-sphere complexes.

J Kumpiene; M Mench; C Bes; J Fitts

2011-12-31T23:59:59.000Z

89

Measuring Hydroxyl Radicals during the Oxidation of Methane, Ethane, Ethylene, and Acetylene in a Shock Tube Using UV Absorption Spectroscopy  

E-Print Network (OSTI)

The hydroxyl (OH) radical is a common intermediate species in any hydrogen- or hydrocarbon-based flame. Investigating OH at elevated temperatures and pressures is not a trivial task, and many considerations must be made to fully study the molecule. Shock tubes can provide the experimenter with a wide range of temperatures and pressures to investigate a variety of combustion characteristics including, but not limited to, OH kinetic profiles. Described in this dissertation is the diagnostic used to measure OH within a shock tube using UV absorption spectroscopy from an enhanced UV Xenon lamp passed through a spectrometer. OH absorption was made over a narrow range of wavelengths around 309.551 nm within the widely studied OH X?A ground vibrational transition region. Experiments have been performed in the shock-tube facility at Texas A&M University using this OH absorption diagnostic. A calibration mixture of stoichiometric H2/O2 diluted in 98% argon by volume was tested initially and compared with a well-known hydrogen-based kinetics mechanism to generate an absorption coefficient correlation. This correlation is valid over the range of conditions observed in the experiments at two pressures near 2 and 13 atm and temperatures from 1182 to 2017 K. Tests were completed using the absorption coefficient correlation on stoichiometric mixtures of methane, methane and water, ethane, ethylene, and acetylene to compare against a comprehensive, detailed chemical kinetics mechanism which considers up through C5 hydrocarbons. Measurements of methane show good agreement in peak OH formation and ignition delay time when compared with the mechanism. Improvements can be made in the shape of the methane-oxygen OH profile, and sensitivity and rate of production analyses were performed with the mechanism to identify key reactions for tuning. Similar results were found for methane-water-oxygen mixtures with no difference in profile shape or ignition delay time noted. There is room for improvement between the mechanism and measured values of OH for ethane-, ethylene-, and acetylene-based mixtures, although interesting pre-ignition features are nonetheless captured relatively well by the mechanism. Uncertainty in the measurement comes from the inherent noise in the photomultiplier tube signal and is ±25-150 ppm for the 2-atm experiments and ±6-25 ppm for the 13-atm experiments.

Aul, Christopher J

2013-05-01T23:59:59.000Z

90

Characterization of the nitrate complexes of Pu(IV) using absorption spectroscopy, {sup 15}N NMR, and EXAFS  

Science Conference Proceedings (OSTI)

Nitrate complexes of Pu(IV) are studied in solutions containing nitrate up to 13 molar (M). Three major nitrato complexes are observed and identified using absorption spectroscopy, {sup 15}N nuclear magnetic resonance (NMR), and extended x-ray absorption fine structure (EXAFS) as Pu(NO{sub 3}){sub 2}{sup 2+}, Pu(NO{sub 3}){sub 4}, and Pu(NO{sub 3}){sub 6}{sup 2{minus}}. The possibility that Pu(NO{sub 3}){sub 1}{sup 3+}, Pu(NO{sub 3}){sub 3}{sup 1+} and Pu(NO{sub 3}){sub 5}{sup 1{minus}} are major species in solution is not consistent with these results and an upper limit of 0.10 can be set on the fraction for each of these three nitrate complexes in nitrate containing solutions. Fraction of the three major species in nitric acid over the 1--13 M range were calculated from absorption spectra data. The fraction of Pu(NO{sub 3}){sub 6}{sup 2{minus}} as a function of nitric acid concentration is in good agreement with the literature, whereas the fraction of Pu(NO{sub 3}){sub 2}{sup 2+} and Pu(NO{sub 3}){sub 4} species differ from previous studies. We have modeled the chemical equilibria up to moderate ionic strength ( < 6 molal) using the specific ion interaction theory (SM. Comparison of our experimental observations to literature stability constants that assume the presence of mononitrate species is poor. Stability constant at zero ionic strength for the dinitrato complex is determined to be log({beta}{sub 2}{sup 0})=3.77 {plus_minus} 0.14 (2{sigma}).

Veirs, D.K.; Smith, C.A.; Zwick, B.D.; Marsh, S.F.; Conradson, S.D.

1993-12-01T23:59:59.000Z

91

Auto-oligomerization and hydration of pyrrole revealed by x-ray absorption spectroscopy  

DOE Green Energy (OSTI)

Near edge x-ray absorption fine structure (NEXAFS) spectra have been measured at the carbon and nitrogen K-edges of the prototypical aromatic molecule, pyrrole, both in the gas phase and when solvated in water, and compared with spectra simulated using a combination of classical molecular dynamics and first principles density functional theory in the excited state core hole approximation. The excellent agreement enabled detailed assignments. Pyrrole is highly reactive, particularly in water, and reaction products formed by the auto-oligomerization of pyrrole are identified. The solvated spectra have been measured at two different temperatures, indicating that the final states remain largely unaffected by both hydration and temperature. This is somewhat unexpected, since the nitrogen in pyrrole can donate a hydrogen bond to water.

Advanced Light Source; Schwartz, Craig P.; Uejio, Janel S.; Duffin, Andrew M.; England, Alice H.; Prendergast, David; Saykally, Richard J

2009-05-29T23:59:59.000Z

92

atomic  

NLE Websites -- All DOE Office Websites (Extended Search)

theory and fundamental quantum mechanics In addition to research on hadronic and nuclear physics, we also conduct research in atomic physics, neutron physics, and quantum...

93

Background-free quasi-steady-state photoinduced absorption spectroscopy by dual optical modulation  

E-Print Network (OSTI)

We present a simple and inexpensive means to measure background-free photoinduced absorption spectra of highly luminescent materials by implementing a dual optical modulation scheme. In our instrument, we modulate a continuous-wave laser, which excites the material of interest resonantly, at a frequency $f_{pu} = 170$\\,Hz with a mechanical chopper. We measure the fractional change of transmission of the sample with a tuneable monochromatic probe source modulated at a frequency $f_{pr} = 139$\\,Hz, and with a digital lockin amplifier at a reference frequency $f_{ref} = f_{pu} + f_{pr} = 309$\\,Hz. We generate the reference sinusoidal wave for the lockin amplifier using a simple home-built electronic circuit that converts the trigger TTL pulsetrains from the two chopper controllers to sine waves and then generates their sum-frequency wave. This scheme allows measurement of the fractional change of transmittance of the sample induced by the pump laser at a frequency $f_{pu} + f_{pr}$ without parasitic signal at a ...

Kallel, Houssem; Paquin, Francis; Rinfret, Robert; Stingelin-Stutzmann, Natalie; Silva, Carlos

2010-01-01T23:59:59.000Z

94

Two-photon absorption spectroscopy of the trivalent cerium ion in calcium fluoride  

Science Conference Proceedings (OSTI)

The two-photon transitions from the lowest 4f to the 5d states of the C/sub 4v/ center in Ce/sup 3 +/:CaF/sub 2/ from 31,900 to 50,500 cm/sup -1/ have been studied with a tunable dye laser as a function of laser wavelength, intensity, polarization and focusing geometry. A fluorescence detection technique was used to measure the two-photon absorption (TPA). The observed TPA spectra consist of two well resolved bands in the wavelength intervals 627 to 590 nm and 520 to 450 nm respectively, and two unresolved bands in the range 410 to 396 nm. At 8/sup 0/K the lowest energy band consists of a zero-phonon line accompanied by its vibrational sideband. The peak TPA cross section for the zero-phonon transition is of the order 5x10/sup -54/ cm/sup 4/sec, indicating significant crystal-field parity mixing for the participating states. The zero-phonon line shows a polarization anisotropy consistent with a Ce/sup 3 +/ site of C/sub 4v/ symmetry. The phonon sideband has a frequency dependent polarization anisotropy. 76 references, 35 figures, 13 tables.

Gayen, S.K.

1984-01-01T23:59:59.000Z

95

Trace metal characterization and speciation in geothermal effluent by multiple scanning anodic stripping voltammetry and atomic absorption analysis  

DOE Green Energy (OSTI)

Recent studies have shown geothermal power plants to have a significant environmental impact on the ground water of the area. The heavy metals arsenic and mercury are special problems, as both are concentrated by flora and fauna exposed to the effluent waters. Because the toxicity of these and other metallic pollutants present in geothermal effluent depends on the chemical form, or speciation, of the particular metal, any serious study of the environmental impact of a geothermal development should include studies of trace metal speciation, in addition to trace metal concentration. This proposal details a method for determining metal speciation in dilute waters. The method is based on ion-exchange and backed by atomic absorption spectrometry and multiple scanning anodic stripping voltammetry. Special laboratory studies will be performed on mercury, arsenic and selenium speciation in synthetic geothermal water. The method will be applied to three known geothermal areas in Washington and Oregon, with emphasis on the speciation of mercury, arsenic and selenium in these waters. The computer controlled electrochemical instrumentation was built and tested. Using this instrumentation, a new experimental procedure was developed to determine the chemical form (speciation) of metal ions in very dilute solutions (ng/ml). This method was tested on model systems including Pb, Cd, and As with C1/sup -/, CO/sub 3//sup 2 -/ and glycine ligands. Finally, the speciation of lead in a geothermal water was examined and the PbC1/sup +/ complex was observed and quantified.

Kowalski, B.R.

1979-05-25T23:59:59.000Z

96

Development of Palladium L-Edge X-Ray Absorption Spectroscopy And Its Application for Chloropalladium Complexes  

Science Conference Proceedings (OSTI)

X-ray absorption spectroscopy (XAS) is a synchrotron-based experimental technique that provides information about geometric and electronic structures of transition metal complexes. Combination of metal L-edge and ligand K-edge XAS has the potential to define the complete experimental ground state electronic structures for metal complexes with unoccupied d manifolds. We developed a quantitative treatment for Pd L-edge spectroscopy on the basis of the well-established chlorine K-edge XAS for a series of chloropalladium complexes that are pre-catalysts in various organic transformations. We found that Pd-Cl bonds are highly covalent, such as 24 {+-} 2%, 34 {+-} 3%, and 48 {+-} 4% chloride 3p character for each Pd-Cl bond in [PdCl{sub 4}]{sup 2-}, [PdCl{sub 6}]{sup 2-}, and PdCl{sub 2}, respectively. Pd(2p {yields} 4d) transition dipole integrals of 20.8 (SSRL)/16.9 (ALS) eV and 14.1 (SSRL)/11.9 (ALS) eV were determined using various combinations of L-edges for Pd(II) and Pd(IV), respectively. Application of metal-ligand covalency and transition dipole integrals were demonstrated for the example of bridging chloride ligands in PdCl{sub 2}. Our work lays the foundation for extending the quantitative treatment to other catalytically important ligands, such as phosphine, phosphite, olefin, amine, and alkyl in order to correlate the electronic structures of palladium complexes with their catalytic activity.

Boysen, R.B.; Szilagyi, R.K.

2009-05-12T23:59:59.000Z

97

X-ray absorption spectroscopy on the calcium cofactor to the manganese cluster in photosynthetic oxygen evolution  

Science Conference Proceedings (OSTI)

Along with Mn, calcium and chloride ions are necessary cofactors for oxygen evolution in Photosystem II (PS II). To further test and verify whether Ca is close to the Mn cluster, the authors substituted strontium for Ca and probed from the Sr point of view for any nearby Mn. The extended X-ray absorption fine structure (EXAFS) of Sr-reactivated PS II indicates major differences between the intact and NH{sub 2}OH-treated samples. In intact samples, the Fourier transform of the Sr EXAFS shows a Fourier peak that is missing in inactive samples. This peak II is best simulated by two Mn neighbors at a distance of 3.5 Angstrom, confirming the proximity of Ca (Sr) cofactor to the Mn cluster. In addition, polarized Sr EXAFS on oriented Sr-reactivated samples shows this peak II is dichroic: large magnitude at 10 degrees (angle between the PS II membrane normal and the x-ray electric field vector) and small at 80 degrees. Analysis of the dichroism yields the relative angle between the Sr-Mn vector and membrane normal (23 degrees {+-} 4 degrees), and the isotropic coordination number for these layered samples. X-ray absorption spectroscopy has also been employed to assess the degree of similarity between the manganese cluster in PS II and a family of synthetic manganese complexes containing the distorted cubane [Mn{sub 4}O{sub 3}X] core (X = benzoate, acetate, methoxide, hydroxide, azide, fluoride, chloride or bromide). In addition, Mn{sub 4}O{sub 3}Cl complexes containing three or six terminal Cl ligands at three of the Mn were included in this study. The EXAFS method detects the small changes in the core structures as X is varied in this series, and serves to exclude these distorted cubanes of C3v symmetry as a topological model for the Mn catalytic cluster. The sulfur K-edge x-ray absorption near-edge structure (XANES) spectra for the amino acids cysteine, methionine, their corresponding oxidized forms cystine and methionine sulfoxide, and glutathione show distinct differences between the thiol and disulfide forms. Sulfur XANES is also used to detect changes (within 5%) of the thiol-to-disulfide ratio in whole human blood, plasma, and erythrocytes.

Cinco, Roehl M.

1999-12-16T23:59:59.000Z

98

Two-photon (vuv and visible) resonant ionization spectroscopy of atoms and molecules  

DOE Green Energy (OSTI)

Two photon spectroscopy of argon, krypton and molecular hydrogen is considered in this paper. Experimental transition energies and two-photon rate constants are given. 4 refs., 1 tab. (LSP)

McCann, M.P.; Chen, C.H.; Payne, M.G.

1987-12-01T23:59:59.000Z

99

Mid- and Far-Infrared Reflection/Absorption Spectroscopy (IRAS) Studies of NO on Rh Single Crystal Surfaces  

DOE Green Energy (OSTI)

The NO/CO reaction over Rh metal in automobile catalytic converters is critical to the control of emissions of these pollutant molecules. As part of a program to determine the elementary mechanism(s) of this reaction, we have been performing mid- and far-infrared reflection/absorption spectroscopic (IRAS) measurements of the adsorption and co-adsorption and co-adsorption of NO and CO on Rh single crystal surfaces. Of particular interest is the low-frequency range of the IRAS spectra where we hoped to observe features due to metal-N stretching and/or bending vibrational motions. In particular, we hoped to obtain information regarding the site-requirements for the dissociation of the NO molecule on various Rh single crystal surfaces. An important result from our earlier work is that the selectivity of the reaction for the two nitrogen-containing products, N2 and N2O, is a strong function of the Rh surface structure. On the basis of ancillary data, we suggested that the location of adsorbed NO and N-atoms (formed from dissociation of adsorbed NO) on various Rh surfaces could, perhaps account for the selectivity differences.

Peden, Charles HF; He, Ting; Pilling, M.; Hirschmugl, Carol J.; Gardner, P.

2001-02-01T23:59:59.000Z

100

Speciation of Trace Elements in Biological and Environmental Samples by X-ray Absorption Spectroscopy: The Role of Plants and Microbes in Remediation  

Science Conference Proceedings (OSTI)

Plants can accumulate, detoxify, and transform trace elements present in contaminated soil and water, leading to the phytoremediation of contaminated sites. An important factor for consideration is the chemical form of trace elements accumulated in tissues of different plant species used for phytoremediation. This report describes the use of X-ray absorption spectroscopy (XAS) for successfully determining the speciation of trace elements in biological and environmental samples.

2001-11-21T23:59:59.000Z

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101

Conduction-band electronic states of YbInCu{sub 4} studied by photoemission and soft x-ray absorption spectroscopies  

SciTech Connect

We have studied conduction-band (CB) electronic states of a typical valence-transition compound YbInCu{sub 4} by means of temperature-dependent hard x-ray photoemission spectroscopy (HX-PES) of the Cu 2p{sub 3/2} and In 3d{sub 5/2} core states taken at h{nu}=5.95 keV, soft x-ray absorption spectroscopy (XAS) of the Cu 2p{sub 3/2} core absorption region around h{nu}{approx}935 eV, and soft x-ray photoemission spectroscopy (SX-PES) of the valence band at the Cu 2p{sub 3/2} absorption edge of h{nu}=933.0 eV. With decreasing temperature below the valence transition at T{sub V}=42 K, we have found that (1) the Cu 2p{sub 3/2} and In 3d{sub 5/2} peaks in the HX-PES spectra exhibit the energy shift toward the lower binding-energy side by {approx}40 and {approx}30 meV, respectively, (2) an energy position of the Cu 2p{sub 3/2} main absorption peak in the XAS spectrum is shifted toward higher photon-energy side by {approx}100 meV, with an appearance of a shoulder structure below the Cu 2p{sub 3/2} main absorption peak, and (3) an intensity of the Cu L{sub 3}VV Auger spectrum is abruptly enhanced. These experimental results suggest that the Fermi level of the CB-derived density of states is shifted toward the lower binding-energy side. We have described the valence transition in YbInCu{sub 4} in terms of the charge transfer from the CB to Yb 4f states.

Utsumi, Yuki; Kurihara, Hidenao; Maso, Hiroyuki; Tobimatsu, Komei [Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526 (Japan); Sato, Hitoshi; Shimada, Kenya; Namatame, Hirofumi [Hiroshima Synchrotron Radiation Center, Hiroshima University, Higashi-Hiroshima 739-0046 (Japan); Hiraoka, Koichi [Graduate School of Science and Engineering, Ehime University, Matsuyama 790-8577 (Japan); Kojima, Kenichi [Graduate School of Integrated Arts and Sciences, Hiroshima University, Higashi-Hiroshima 739-8521 (Japan); Ohkochi, Takuo; Fujimori, Shin-ichi; Takeda, Yukiharu; Saitoh, Yuji [Synchrotron Radiation Research Center, Japan Atomic Energy Agency, Hyogo 679-5148 (Japan); Mimura, Kojiro [Graduate School of Engineering, Osaka Prefecture University, Sakai 599-8531 (Japan); Ueda, Shigenori; Yamashita, Yoshiyuki; Yoshikawa, Hideki; Kobayashi, Keisuke [NIMS Beamline Station at SPring-8, National Institute for Materials Science, Hyogo 679-5148 (Japan); Oguchi, Tamio [ISIR, Osaka University, Ibaraki 567-0047 (Japan); Taniguchi, Masaki [Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526 (Japan); Hiroshima Synchrotron Radiation Center, Hiroshima University, Higashi-Hiroshima 739-0046 (Japan)

2011-09-15T23:59:59.000Z

102

In situ calibration of inductively coupled plasma-atomic emission and mass spectroscopy  

DOE Patents (OSTI)

A method and apparatus for in situ addition calibration of an inductively coupled plasma atomic emission spectrometer or mass spectrometer using a precision gas metering valve to introduce a volatile calibration gas of an element of interest directly into an aerosol particle stream. The present situ calibration technique is suitable for various remote, on-site sampling systems such as laser ablation or nebulization.

Braymen, Steven D. (Ames, IA)

1996-06-11T23:59:59.000Z

103

In situ calibration of inductively coupled plasma-atomic emission and mass spectroscopy  

DOE Patents (OSTI)

A method and apparatus are disclosed for in situ addition calibration of an inductively coupled plasma atomic emission spectrometer or mass spectrometer using a precision gas metering valve to introduce a volatile calibration gas of an element of interest directly into an aerosol particle stream. The present in situ calibration technique is suitable for various remote, on-site sampling systems such as laser ablation or nebulization. 5 figs.

Braymen, S.D.

1996-06-11T23:59:59.000Z

104

Rydberg Spectroscopy in an Optical Lattice: Blackbody Thermometry for Atomic Clocks  

E-Print Network (OSTI)

We show that optical spectroscopy of Rydberg states can provide accurate {\\em in situ} thermometry at room-temperature. Transitions from a metastable state to Rydberg states with principal quantum numbers of 25 to 30 have 200 times larger fractional frequency sensitivities to blackbody radiation than the Strontium clock transition. We demonstrate that magic wavelength lattices exist for both Strontium and Ytterbium transitions between the metastable and Rydberg states. Frequency measurements of Rydberg transitions with $10^{-16}$ accuracy provide $10 \\, \\mathrm{mK}$ resolution and yield a blackbody uncertainty for the clock transition of $10^{-18}$.

Ovsiannikov, Vitali D; Gibble, Kurt

2011-01-01T23:59:59.000Z

105

Quantitative broadband absorption and scattering spectroscopy in turbid media by combined frequency-domain and steady state methodologies  

DOE Patents (OSTI)

A technique for measuring broadband near-infrared absorption spectra of turbid media that uses a combination of frequency-domain and steady-state reflectance methods. Most of the wavelength coverage is provided by a white-light steady-state measurement, whereas the frequency-domain data are acquired at a few selected wavelengths. Coefficients of absorption and reduced scattering derived from the frequency-domain data are used to calibrate the intensity of the steady-state measurements and to determine the reduced scattering coefficient at all wavelengths in the spectral window of interest. The absorption coefficient spectrum is determined by comparing the steady-state reflectance values with the predictions of diffusion theory, wavelength by wavelength. Absorption spectra of a turbid phantom and of human breast tissue in vivo, derived with the combined frequency-domain and steady-state technique, agree well with expected reference values.

Tromberg, Bruce J. (Irvine, CA); Berger, Andrew J. (Rochester, NY); Cerussi, Albert E. (Lake Forest, CA); Bevilacqua, Frederic (Costa Mesa, CA); Jakubowski, Dorota (Irvine, CA)

2008-09-23T23:59:59.000Z

106

Influence of the cobalt particle size in the CO hydrogenation reaction studied by in situ X-ray absorption spectroscopy  

E-Print Network (OSTI)

Cobalt, nanoparticles, Fischer-Tropsch, X-ray absorption (oxides [5] and Fischer-Tropsch (FT) synthesis [6,7]. Itswhich is inactive for Fischer-Tropsch synthesis. This oxide

Herranz, Tirma

2010-01-01T23:59:59.000Z

107

Application of a diode-laser-based ultraviolet absorption sensor for in situ measurements of atomic mercury in coal-combustion exhaust  

SciTech Connect

A diode-laser-based ultraviolet absorption sensor was successfully demonstrated for both in situ and extractive sampling atomic mercury measurements in a laboratory-scale 29.3 kWt (100 000 BTU/h) coal combustor and in situ measurements in a flow reactor at Texas A&M University. Laser sensor measurements were compared to measurements from a commercial mercury analyzer (CMA). A 375 nm single-mode laser and a 784 nm distributed feedback (DFB) laser are sum-frequency-mixed in a nonlinear {beta}-barium borate crystal to generate a 254 nm beam. By tuning the frequency of the DFB laser, the ultraviolet beam frequency was tuned across the transition frequency of mercury at 253.7 nm. The tuning range was large enough that an off-resonant baseline was clearly visible on both sides of the Hg transition. No pretreatment is required for elemental mercury measurements, and the effects of broadband absorption can be effectively eliminated during data analysis. Extractive sampling was demonstrated to improve the detection limit of the sensor and demonstrate the feasibility of total mercury concentration measurements in the future through extractive sampling. Significant variation in the atomic mercury concentration of coal-combustion exhaust was observed over short time periods during our in situ measurements. The sensor detection limits for in situ and extractive sampling are 0.3 and 0.1 parts per billion over a 1 m path length, respectively. 34 refs., 11 figs., 2 tabs.

Jesse K. Magnuson; Thomas N. Anderson; Robert P. Lucht; Udayasarathy A. Vijayasarathy; Hyukjin Oh; Kalyan Annamalai; Jerald A. Caton [Purdue University, West Lafayette, IN (United States). School of Mechanical Engineering

2008-09-15T23:59:59.000Z

108

X-ray absorption spectroscopy of aluminum z-pinch plasma with tungsten backlighter planar wire array source  

Science Conference Proceedings (OSTI)

Absorption features from K-shell aluminum z-pinch plasmas have recently been studied on Zebra, the 1.7 MA pulse power generator at the Nevada Terawatt Facility. In particular, tungsten plasma has been used as a semi-backlighter source in the generation of aluminum K-shell absorption spectra by placing a single Al wire at or near the end of a single planar W array. All spectroscopic experimental results were recorded using a time-integrated, spatially resolved convex potassium hydrogen phthalate (KAP) crystal spectrometer. Other diagnostics used to study these plasmas included x-ray detectors, optical imaging, laser shadowgraphy, and time-gated and time-integrated x-ray pinhole imagers. Through comparisons with previous publications, Al K-shell absorption lines are shown to be from much lower electron temperature ({approx}10-40 eV) plasmas than emission spectra ({approx}350-500 eV).

Osborne, G. C.; Kantsyrev, V. L.; Safronova, A. S.; Esaulov, A. A.; Weller, M. E.; Shrestha, I.; Shlyaptseva, V. V. [Physics Department, University of Nevada, Reno, Reno, Nevada 89557 (United States); Ouart, N. D. [Naval Research Laboratory, Washington, D.C. 20375 (United States)

2012-10-15T23:59:59.000Z

109

FINGERPRINTING INORGANIC ARSENIC AND ORGANOARSENIC COMPOUNDS IN IN SITU OIL SHALE RETORT AND PROCESS VOTERS USING A LIQUID CHROMATOGRAPH COUPLED WITH AN ATOMIC ABSORPTION SPECTROMETER AS A DETECTOR  

SciTech Connect

Inorganic arsenic and organoarsenic compounds were speciated in seven oil shale retort and process waters, including samples from simulated, true and modified in situ processes, using a high performance liquid chromatograph automatically coupled to a graphite furnace atomic absorption detector. The molecular forms of arsenic at ppm levels (({micro}g/mL) in these waters are identified for the first time, and shown to include arsenate, methylarsonic acid and phenylarsonic acid. An arsenic-specific fingerprint chromatogram of each retort or process water studied has significant impliestions regarding those arsenical species found and those marginally detected, such as dimethylarsinic acid and the suspected carcinogen arsenite. The method demonstrated suggests future means for quantifying environmental impacts of bioactive organometal species involved in oil shale retorting technology.

Fish, Richard H.; Brinckman, Frederick E.; Jewett, Kenneth L.

1981-07-01T23:59:59.000Z

110

Isotope and Temperature Effects in Liquid Water Probed by X-RayAbsorption and Resonant X-Ray Emission Spectroscopy  

DOE Green Energy (OSTI)

High-resolution x-ray absorption and emission spectra ofliquid water exhibit a strong isotope effect. Further, the emissionspectra show a splitting of the 1b1 emission line, a weak temperatureeffect, and a pronounced excitation-energy dependence. They can bedescribed as a superposition of two independent contributions. Bycomparing with gasphase, ice, and NaOH/NaOD, we propose that the twocomponents are governed by the initial state hydrogen bondingconfiguration and ultrafast dissociation on the time scale of the O 1score hole decay.

Fuchs, O.; Zharnikov, M.; Weinhardt, L.; Blum, M.; Weigand, M.; Zubavichus, Y.; Bar, M.; Maier, F.; Denlinger, J.D.; Heske, C.; Grunze,M.; Umbach, E.

2007-03-10T23:59:59.000Z

111

NIST Atomic Spectroscopy Databases  

Science Conference Proceedings (OSTI)

... Sansonetti, WC Martin, and SL Young This handbook provides a ... constants from the Recommended Values of the Fundamental Physical Constants ...

2013-06-17T23:59:59.000Z

112

High Energy Resolution Fluorescence Detection X-Ray Absorption Spectroscopy: Detection of Adsorption Sites in Supported Metal Catalysts  

Science Conference Proceedings (OSTI)

High energy resolution fluorescence detection (HERFD) X-ray adsorption spectroscopy (XAS) is demonstrated as a new tool to identify the geometry of metal adsorption sites and the orbitals involved in bonding. The type of CO adsorption site on a nanoparticular Pt-Al2O3 catalyst is determined. The orbitals involved in the Pt - CO bonding are identified using theoretical FEFF8.0 calculations. In situ application of HERFD XAS is applicable to a large number of catalytic systems and will provide fundamental insights in structure - performance relationships.

Tromp, Moniek [University of Southampton, School of Chemistry, Highfield, Southampton, SO17 1BJ (United Kingdom); Bokhoven, Jeroen A. van [Institute for chemical and bioengineering ETH Zurich (Switzerland); Safonova, Olga V.; Glatzel, Pieter [ESRF, Grenoble (France); Groot, Frank M. F. de [Utrecht University, Utrecht (Netherlands); Evans, John [University of Southampton, School of Chemistry, Highfield, Southampton, SO17 1BJ (United Kingdom); Diamond Light Source, Didcot (United Kingdom)

2007-02-02T23:59:59.000Z

113

Electronic structure of phospho-olivines LixFePO4 (x=0,1) fromsoft-x-ray-absorption and -emission spectroscopies  

Science Conference Proceedings (OSTI)

The electronic structure of the phospho-olivine LixFePO4 wasstudied using soft-x-ray-absorption (XAS) and emission spectroscopies.Characteristic changes in the valence and conduction bands are observedupon delithation of LiFePO4 into FePO4. In LiFePO4, the Fe-3d states arelocalized with little overlap with the O-2p states. Delithiation ofLiFePO4 gives stronger hybridization between Fe-3d states and O-2p statesleading to delocalization of the O-2p states. The Fe L-edge absorptionspectra yield "fingerprints" of the different valence states of Fe inLiFePO4 and FePO4. Resonant soft-x-ray-emission spectroscopy at the Fe Ledge shows strong contributions from resonant inelastic soft x-rayscattering (RIXS), which is described using an ionic picture of the Fe-3dstates. Together the Fe L-edge XAS and RIXS study reveals a bondingcharacter of the Fe 3d-O2p orbitals in FePO4 in contrast to a nonbondingcharacter in LiFePO4.

Augustsson, A.; Zhuang, G.V.; Butorin, S.M.; Osorio-Guillen,J.M.; Dong, C.L.; Ahuja, R.; Chang, C.L.; Ross, P.N.; Nordgren, J.; Guo,J.-H.

2005-07-17T23:59:59.000Z

114

Laser produced plasma diagnostics by cavity ringdown spectroscopy and applications  

SciTech Connect

Laser-produced plasmas have many applications for which detailed characterization of the plume is requested. Cavity ring-down spectroscopy is a versatile absorption method which provides data on the plume and its surroundings, with spatial and temporal resolution. The measured absorption line shapes contain information about angular and velocity distributions within the plume. In various plasmas we have observed molecules or metastable atoms which were not present in the emission spectra.

Milosevic, S. [Institute of Physics, Zagreb (Croatia)

2012-05-25T23:59:59.000Z

115

Hydrogen absorption in epitaxial W/Nb(001) and polycrystalline Fe/Nb(110) multilayers studied in-situ by X-ray/neutron scattering techniques and X-ray absorption spectroscopy  

DOE Green Energy (OSTI)

Hydrogen can be absorbed in large quantities by 100 {angstrom} thin Nb layers embedded in epitaxial W/Nb and polycrystalline Fe/Nb multilayers. The solubility and the hydrogen-induced structural changes of the host lattice are explored in-situ by small-angle neutron/X-ray reflectometry and high-angle diffraction. These measurements reveal for both systems that the relative out-of-plane expansion of the Nb layers is considerably larger than the relative increase of the Nb interplanar spacing indicating two distinctly different mechanisms of hydrogen absorption. In Fe/Nb multilayers, hydrogen expands the Nb interplanar spacing in a continuous way as function of the external pressure. In contrast, the Nb lattice expansion is discontinuous in epitaxial W/Nb multilayers: A jump in the Nb(002) Bragg reflection position occurs at a critical hydrogen pressure of 1 mbar. In-situ EXAFS spectroscopy also exhibits an irreversible expansion of the Nb lattice in the film plane for p{sub H{sub 2}}> 1 mbar. This can be regarded as a structural phase transition from an exclusively out-of-plane to a three-dimensionally expanded state at low and high hydrogen pressures, respectively.

Klose, F.; Rehm, C.; Fieber-Erdmann, M.; Holub-Krappe, E.; Bleif, H. J.; Sowers, H.; Goyette, R.; Troger, L.; Maletta, H.

1999-11-02T23:59:59.000Z

116

THE STELLAR INITIAL MASS FUNCTION IN EARLY-TYPE GALAXIES FROM ABSORPTION LINE SPECTROSCOPY. I. DATA AND EMPIRICAL TRENDS  

Science Conference Proceedings (OSTI)

The strength of gravity-sensitive absorption lines in the integrated light of old stellar populations is one of the few direct probes of the stellar initial mass function (IMF) outside of the Milky Way. Owing to the advent of fully depleted CCDs with little or no fringing it has recently become possible to obtain accurate measurements of these features. Here, we present spectra covering the wavelength ranges 0.35-0.55 {mu}m and 0.72-1.03 {mu}m for the bulge of M31 and 34 early-type galaxies from the SAURON sample, obtained with the Low Resolution Imaging Spectrometer on Keck. The signal-to-noise ratio is {approx}> 200 A{sup -1} out to 1 {mu}m, which is sufficient to measure gravity-sensitive features for individual galaxies and to determine how they depend on other properties of the galaxies. Combining the new data with previously obtained spectra for globular clusters in M31 and the most massive elliptical galaxies in the Virgo cluster, we find that the dwarf-sensitive Na I {lambda}8183, 8195 doublet and the FeH {lambda}9916 Wing-Ford band increase systematically with velocity dispersion, while the giant-sensitive Ca II {lambda}8498, 8542, 8662 triplet decreases with dispersion. These trends are consistent with a varying IMF, such that galaxies with deeper potential wells have more dwarf-enriched mass functions. In a companion paper, we use a comprehensive stellar population synthesis model to demonstrate that IMF effects can be separated from age and abundance variations and quantify the IMF variation among early-type galaxies.

Van Dokkum, Pieter G. [Department of Astronomy, Yale University, New Haven, CT 06511 (United States); Conroy, Charlie [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States)

2012-11-20T23:59:59.000Z

117

LASER ABLATION-INDUCTIVELY COUPLED PLASMA-ATOMIC EMISSION SPECTROSCOPY STUDY AT THE 222-S LABORATORY USING HOT-CELL GLOVE BOX PROTOTYPE SYSTEM  

SciTech Connect

This report describes the installation, testing, and acceptance of the Waste Treatment and Immobilization Plant (WTP) procured laser ablation-inductively coupled plasma-atomic emission spectroscopy (LA-ICP-AES) system for remotely analyzing high-level waste (HLW) samples in a hot cell environment. The work was completed by the Analytical Process Development (APD) group in accordance with Task Order 2005-003; ATS MP 1027, Management Plan for Waste Treatment Plant Project Work Performed by Analytical Technical Services. The APD group at the 222-S Laboratory demonstrated acceptable turnaround time (TAT) and provide sufficient data to assess sensitivity, accuracy, and precision of the LA-ICP-AES method.

SEIDEL CM; JAIN J; OWENS JW

2009-02-23T23:59:59.000Z

118

LASER ABLATION-INDUCTIVELY COUPLED PLASMA-ATOMIC EMISSION SPECTROSCOPY STUDY AT THE 222-S LABORATORY USING HOT-CELL GLOVE BOX PROTOTYPE SYSTEM  

SciTech Connect

This report describes the installation, testing and acceptance of the Waste Treatment and Immobilization Plant procured laser ablation-inductively coupled plasma-atomic emission spectroscopy (LA-ICP-AES) system for remotely analyzing high-level waste samples in a hot cell environment. The 2005-003; ATS MP 1027, Management Plan for Waste Treatment Plant Project Work Performed by Analytical Technical Services. The APD group at the 222-S laboratory demonstrated acceptable turnaround time (TAT) and provide sufficient data to assess sensitivity, accuracy, and precision of the LA-ICP-AES method.

LOCKREM LL; OWENS JW; SEIDEL CM

2009-03-26T23:59:59.000Z

119

Formation of an SEI on a LiMn(2)O(4) Cathode during Room Temperature Charge-Discharge Cycling Studied by Soft X-Ray Absorption Spectroscopy at the Fluorine K-edge  

DOE Green Energy (OSTI)

The solid electrolyte interface (SEI) formation on the surface of LiMn{sub 2}O{sub 4} electrodes during room temperature charge-discharge cycling was studied using soft X-ray absorption spectroscopy at the Fluorine (F) K-edge. LiMn{sub 2}O{sub 4} electrodes without any binder were prepared by electrostatic spray deposition to eliminate the signal originating from the PVDF binder in the F K-edge X-ray absorption spectra. The F K-edge absorption spectra show that the SEI layer forms at a very early stage of cycling. SEI growth takes place during discharge. In addition, LiF formation is accelerated if the discharge step follows a charge step. The F K-edge absorption spectra suggest that the major component of the SEI is LiF.

Chung, K.Y.; Yang, X.; Yoon, W.-S.; Kim, K.-B.; Cho, B.-W.

2011-11-01T23:59:59.000Z

120

Validity of automated x-ray photoelectron spectroscopy algorithm to determine the amount of substance and the depth distribution of atoms  

SciTech Connect

The author reports a systematic study of the range of validity of a previously developed algorithm for automated x-ray photoelectron spectroscopy analysis, which takes into account the variation in both peak intensity and the intensity in the background of inelastically scattered electrons. This test was done by first simulating spectra for the Au4d peak with gold atoms distributed in the form of a wide range of nanostructures, which includes overlayers with varying thickness, a 5 A layer of atoms buried at varying depths and a substrate covered with an overlayer of varying thickness. Next, the algorithm was applied to analyze these spectra. The algorithm determines the number of atoms within the outermost 3 {lambda} of the surface. This amount of substance is denoted AOS{sub 3{lambda}} (where {lambda} is the electron inelastic mean free path). In general the determined AOS{sub 3{lambda}} is found to be accurate to within {approx}10-20% depending on the depth distribution of the atoms. The algorithm also determines a characteristic length L, which was found to give unambiguous information on the depth distribution of the atoms for practically all studied cases. A set of rules for this parameter, which relates the value of L to the depths where the atoms are distributed, was tested, and these rules were found to be generally valid with only a few exceptions. The results were found to be rather independent of the spectral energy range (from 20 to 40 eV below the peak energy) used in the analysis.

Tougaard, Sven [Department of Physics, Chemistry, and Pharmacy, University of Southern Denmark, Odense M DK-5230 (Denmark)

2013-05-15T23:59:59.000Z

Note: This page contains sample records for the topic "atomic absorption spectroscopy" 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

NIST: Atomic Spectros. - Spectral Continuum Radiation  

Science Conference Proceedings (OSTI)

Atomic Spectroscopy: home page. 21. Spectral Continuum Radiation. Hydrogenic Species. Precise quantum-mechanical ...

122

Tenth Atomic Physics Program workshop  

Science Conference Proceedings (OSTI)

This report contains short papers and abstracts on the following main topics: Ion-atom collision theory; laser physics; spectroscopy of atoms; spectroscopy of ions; and high velocity collisions.

Not Available

1989-10-01T23:59:59.000Z

123

Non-MT Determination of X-Ray Absorption Cross-Section's Factorized Atomic Part in the Near-Edge Region. Application to Si K-Edge XANES Analysis in Beta-Zeolites  

SciTech Connect

An algorithm and code for the determination of the factorized atomic part of the absorption cross-section from experimental spectra in the XANES region were generated and tested on Al and Si K-edge XANES in reference compounds and applied to zeolite Beta with various Si/Al ratios. However, replacement of the theoretically determined background with the experimental absorption cross-section significantly improved the agreement with experiment. The spectral analysis showed that the XANES region can be used to extract detailed structural information when the Muffin-tin approximation can be avoided. Asymmetry in the silicon oxide tetrahedron was observed when increasing the aluminum content of the zeolite.

Bugaev, L. A.; Avakyan, L. A.; Latokha, Ya. V. [Physical Department of Rostov State University, Zorge str., 5, Rostov-on-Don, 344090 (Russian Federation); Bokhoven, J. A. van [Institute for Chemical and Bioengineering, ETH Zurich, 8093 Zurich (Switzerland)

2007-02-02T23:59:59.000Z

124

X-ray absorption spectroscopy  

E-Print Network (OSTI)

crystal XAS data from PS II at SSRL BL 9-3. It consists of aRadiation Laboratory (SSRL), the Advanced Light Source (operated by DOE OBES. The SSRL Biomedical Technology program

Yano, Junko; Yachandra, Vittal K.

2009-01-01T23:59:59.000Z

125

X-ray Absorption Spectroscopy  

E-Print Network (OSTI)

crystal XAS data from PS II at SSRL BL 9-3. It consists of aRadiation Laboratory (SSRL), the Advanced Light Source (operated by DOE OBES. The SSRL Biomedical Technology program

Yano, Junko

2010-01-01T23:59:59.000Z

126

Quantitative Excited State Spectroscopy of a Single InGaAs Quantum Dot Molecule through Multi-million Atom Electronic Structure Calculations  

E-Print Network (OSTI)

Atomistic electronic structure calculations are performed to study the coherent inter-dot couplings of the electronic states in a single InGaAs quantum dot molecule. The experimentally observed excitonic spectrum [12] is quantitatively reproduced, and the correct energy states are identified based on a previously validated atomistic tight binding model. The extended devices are represented explicitly in space with 15 million atom structures. An excited state spectroscopy technique is presented in which the externally applied electric field is swept to probe the ladder of the electronic energy levels (electron or hole) of one quantum dot through anti-crossings with the energy levels of the other quantum dot in a two quantum dot molecule. Such technique can be applied to estimate the spatial electron-hole spacing inside the quantum dot molecule as well as to reverse engineer the quantum dot geometry parameters such as the quantum dot separation. Crystal deformation induced piezoelectric effects have been discus...

Usman, Muhammad; Ryu, Hoon; Ahmed, Shaikh; Boykin, Timothy; Klimeck, Gerhard

2011-01-01T23:59:59.000Z

127

Development of laser absorption sensors for combustion gases.  

E-Print Network (OSTI)

??In situ sensors based on laser absorption spectroscopy are developed to monitor key species in combustion exhaust gases. Direct absorption (DA) and wavelength-modulation-spectroscopy (WMS) strategies… (more)

Chao, Xing.

2012-01-01T23:59:59.000Z

128

NIST: Atomic Spectroscopy Group - Classical Spectroscopy  

Science Conference Proceedings (OSTI)

... of singly-ionized mercury (Hg II) The spectra and energy levels of ... it plays a prominent role in some chemically peculiar stars recently observed with ...

2010-10-05T23:59:59.000Z

129

UNDERSTANDING THE LOCAL ATOMIC LEVEL EFFECTS OF DOPANTS IN COMPLEX METAL HYDRIDES USING SYNCHROTRON XRAY ABSORPTION SPECTROSCOPY AND DENSITY FUNCTIONAL THEORY  

SciTech Connect

This work resulted in five peer-reviewed journal publications (appended), as well as one doctoral dissertation and two masters theses.

Dobbins, Tabbetha

2013-02-15T23:59:59.000Z

130

Quantitative Excited State Spectroscopy of a Single InGaAs Quantum Dot Molecule through Multi-million Atom Electronic Structure Calculations  

E-Print Network (OSTI)

Atomistic electronic structure calculations are performed to study the coherent inter-dot couplings of the electronic states in a single InGaAs quantum dot molecule. The experimentally observed excitonic spectrum [12] is quantitatively reproduced, and the correct energy states are identified based on a previously validated atomistic tight binding model. The extended devices are represented explicitly in space with 15 million atom structures. An excited state spectroscopy technique is presented in which the externally applied electric field is swept to probe the ladder of the electronic energy levels (electron or hole) of one quantum dot through anti-crossings with the energy levels of the other quantum dot in a two quantum dot molecule. This technique can be applied to estimate the spatial electron-hole spacing inside the quantum dot molecule as well as to reverse engineer quantum dot geometry parameters such as the quantum dot separation. Crystal deformation induced piezoelectric effects have been discussed in the literature as minor perturbations lifting degeneracies of the electron excited (P and D) states, thus affecting polarization alignment of wave function lobes for III-V Heterostructures such as single InAs/GaAs quantum dots. In contrast this work demonstrates the crucial importance of piezoelectricity to resolve the symmetries and energies of the excited states through matching the experimentally measured spectrum in an InGaAs quantum dot molecule under the influence of an electric field. Both linear and quadratic piezoelectric effects are studied for the first time for a quantum dot molecule and demonstrated to be indeed important. The net piezoelectric contribution is found to be critical in determining the correct energy spectrum, which is in contrast to recent studies reporting vanishing net piezoelectric contributions.

Muhammad Usman; Yui-Hong Matthias Tan; Hoon Ryu; Shaikh S. Ahmed; Hubert Krenner; Timothy B. Boykin; Gerhard Klimeck

2010-08-18T23:59:59.000Z

131

Quick-scanning x-ray absorption spectroscopy system with a servo-motor-driven channel-cut monochromator with a temporal resolution of 10 ms  

SciTech Connect

We have developed a quick-scanning x-ray absorption fine structure (QXAFS) system and installed it at the recently constructed synchrotron radiation beamline BL33XU at the SPring-8. Rapid acquisition of high-quality QXAFS data was realized by combining a servo-motor-driven Si channel-cut monochromator with a tapered undulator. Two tandemly aligned monochromators with channel-cut Si(111) and Si(220) crystals covered energy ranges of 4.0-28.2 keV and 6.6-46.0 keV, respectively. The system allows the users to adjust instantly the energy ranges of scans, the starting angles of oscillations, and the frequencies. The channel-cut crystals are cooled with liquid nitrogen to enable them to withstand the high heat load from the undulator radiation. Deformation of the reflecting planes is reduced by clamping each crystal with two cooling blocks. Performance tests at the Cu K-edge demonstrated sufficiently high data quality for x-ray absorption near-edge structure and extended x-ray absorption fine-structure analyses with temporal resolutions of up to 10 and 25 ms, respectively.

Nonaka, T.; Dohmae, K.; Araki, T.; Hayashi, Y.; Hirose, Y. [Toyota Central R and D Labs., Inc., Nagakute, Aichi 480-1192 (Japan); Uruga, T.; Yamazaki, H.; Tanida, H.; Goto, S. [JASRI/Spring-8, 1-1-1, Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Mochizuki, T. [JASRI/Spring-8, 1-1-1, Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Toyama Corp., Zama, Kanagawa 228-0003 (Japan)

2012-08-15T23:59:59.000Z

132

Precision spectroscopy by photon-recoil signal amplification  

E-Print Network (OSTI)

Precision spectroscopy of atomic and molecular ions offers a window to new physics, but is typically limited to species with a cycling transition for laser cooling and detection. Quantum logic spectroscopy has overcome this limitation for species with long-lived excited states. Here, we extend quantum logic spectroscopy to fast, dipole-allowed transitions and apply it to perform an absolute frequency measurement. We detect the absorption of photons by the spectroscopically investigated ion through the photon recoil imparted on a co-trapped ion of a different species, on which we can perform efficient quantum logic detection techniques. This amplifies the recoil signal from a few absorbed photons to thousands of fluorescence photons. We resolve the line center of a dipole-allowed transition in 40Ca+ to 1/300 of its observed linewidth, rendering this measurement one of the most accurate of a broad transition. The simplicity and versatility of this approach enables spectroscopy of many previously inaccessible species.

Yong Wan; Florian Gebert; Jannes B. Wübbena; Nils Scharnhorst; Sana Amairi; Ian D. Leroux; Börge Hemmerling; Niels Lörch; Klemens Hammerer; Piet O. Schmidt

2013-09-26T23:59:59.000Z

133

XMM-Newton and Chandra Spectroscopy of the Variable High-Energy Absorption of PG 1115+080: Refined Outflow Constraints  

E-Print Network (OSTI)

We present results from multi-epoch spectral analysis of XMM-Newton and Chandra observations of the mini broad absorption line (BAL) quasar PG 1115+080. This is one of the few X-ray detected mini-BAL quasars to date that is bright enough in the X-ray band, mostly due to large gravitational-lensing magnifications, to allow in-depth spectral analysis. The present XMM-Newton observations of PG 1115+080 have provided the highest signal-to-noise X-ray spectra of a mini-BAL quasar obtained to date. By modeling the spectra of PG 1115+080 we have obtained constraints on the column density and ionization state of its outflowing absorbing gas. A comparison between these constraints over several epochs indicates significant variability in the properties of the outflowing absorbers in PG 1115+080. The depths of the high-energy broad absorption features in PG 1115+080 show a significant decrease between the first two observation epochs separated by a rest-frame timescale of ~ 1 year. This variability supports the intrinsic nature of these absorbers. Assuming the interpretation that the high-energy absorption features arise from highly ionized Fe XXV we constrain the fraction of the total bolometric energy released by quasars PG 1115+080 and APM 08279+5225 into the IGM in the form of kinetic energy to be epsilon_k = 0.64(-0.40,+0.52) (68% confidence), and epsilon_k =0.09(-0.05,+0.07), respectively. According to recent theoretical studies this range of efficiencies is large enough to influence significantly the formation of the host galaxy and to regulate the growth of the central black hole.

G. Chartas; W. N. Brandt; S. C. Gallagher; D. Proga

2007-01-04T23:59:59.000Z

134

Multivariate Curve Resolution Analysis for Interpretation of Dynamic Cu K-Edge X-ray Absorption Spectroscopy Spectra for a Cu Doped V2O5 Lithium Battery  

DOE Green Energy (OSTI)

Vanadium pentoxide materials prepared through sol-gel processes act as excellent intercalation hosts for lithium as well as polyvalent cations. A chemometric approach has been applied to study the X-ray absorption near-edge structure (XANES) evolution during in situ scanning of the Cu{sub 0.1}V{sub 2}O{sub 5} xerogel/Li ions battery. Among the more common techniques, the fixed size windows evolving factor analysis (FSWEFA) permits the number of species involved in the experiment to be determined and the range of existence of each of them. This result, combined with the constraints of the invariance of the total concentration and non-negativity of both concentrations and spectra, enabled us to obtain the spectra of the pure components using a multivariate curve resolution refined by an alternate least squares fitting procedure. This allowed the normalized concentration profile to be understood. This data treatment evidenced the occurrence, for the first time, of three species during the battery charging. This fact finds confirmation by comparison of the pure spectra with the experimental ones. Extended X-ray absorption fine structure (EXAFS) analysis confirms the occurrence of three different chemical environments of Cu during battery charging.

Conti, P.; Zamponi, S; Giorgetti, M; Berrettoni, M; Smyrl, W

2010-01-01T23:59:59.000Z

135

Detection of water absorption in the dayside atmosphere of HD 189733 b using ground-based high-resolution spectroscopy at 3.2 microns  

E-Print Network (OSTI)

We report a 5 sigma detection of water absorption features in the dayside spectrum of the hot Jupiter HD 189733 b. We used high-resolution (R~100,000) spectra taken at 3.2 microns with CRIRES on the VLT to trace the radial velocity shift of the water features in the planet's dayside atmosphere during 5 hours of its 2.2 day orbit as it approached secondary eclipse. Despite considerable telluric contamination in this wavelength regime, we detect the signal within our uncertainties at the expected combination of systemic velocity (Vsys=-3 +5-6 km/s) and planet orbital velocity (Kp=154 +14-10 km/s), and determine a H2O line contrast ratio of (1.3+/-0.2)x10^-3 with respect to the stellar continuum. We find no evidence of significant absorption or emission from other carbon-bearing molecules, such as methane, although we do note a marginal increase in the significance of our detection with the inclusion of carbon dioxide in our template spectrum. This result demonstrates that ground-based, high-resolution spectrosc...

Birkby, J L; Brogi, M; de Mooij, E J W; Schwarz, H; Albrecht, S; Snellen, I A G

2013-01-01T23:59:59.000Z

136

Statistically meaningful data on the chemical state of ironprecipitates in processed multicrystalline silicon usingsynchrotron-based X-ray absorption spectroscopy  

DOE Green Energy (OSTI)

X-ray fluorescence microscopy (mu-XRF), x-ray beam induced current (XBIC), and x-ray absorption spectromicroscopy (mu-XAS) were performed on fully-processed Bay Six cast multicrystalline silicon and aluminum-gettered AstroPower Silicon-Film(TM) sheet material. Over ten iron precipitates--predominantly of iron silicide--were identified at low lifetime regions in both materials, both at grain boundaries and intragranular defects identified by XBIC. In addition, large (micron-sized) particles containing oxidized iron and other impurities (Ca, Cr, Mn) were found in BaySix material. The smaller iron silicide precipitates were more numerous and spatially distributed than their larger oxidized iron counterparts, and thus deemed more detrimental to minority carrier diffusion length.

Buonassisi, T.; Heuer, M.; Istratov, A.A.; Weber, E.R.; Cai, Z.; Lai, B.; Marcus, M.; Lu, J.; Rozgonyi, G.; Schindler, R.; Jonczyk, R.; Rand, J.

2004-11-08T23:59:59.000Z

137

VOLUME 67, NUMBER 15 PHYSICAL REVIEW LETTERS 7 OCTOBER 1991 Time-Resolved Two-Dimensional Spectroscopy of Optically Driven Atomic Sublevel Coherences  

E-Print Network (OSTI)

between atomic substates are driven by a resonant interaction with light and transferred between polarizations in the medium, but, in the frequently encountered case of multi- ple substates of the electronic ground state, also popula- tion differences and coherences between these sublevels [1]. These atomic

Suter, Dieter

138

An in situ X-ray absorption spectroscopy investigation of the effect of Sn additions to carbon-supported Pt electrocatalysts: Part 1  

Science Conference Proceedings (OSTI)

Carbon-supported platinum (Pt/C) with an adsorbed layer of underpotential deposited (upd) Sn is a much better catalyst for the methanol oxidation reaction (MOR) than a carbon-supported platinum-tin (PtSn/C) alloy. In situ X-ray absorption (XAS) was used to determine the differences in the effects that the two methods of Sn addition have on the electronic properties and the structural properties of the catalyst. X-ray diffraction and XAS at the Pt L{sub 3} and L{sub 2} edges indicate that the PtSn/C catalyst has a Pt{sub 3}Sn L1{sub 2} structure, and alloying with Sn causes partial filling of the Pt d band vacancies and an increase in the Pt-Pt bond distance from 2.77 to 2.8 {angstrom}. However, upd Sn does not perturb Pt structurally or electronically. XAS at the Sn K edge indicates that both the upd Sn on Pt/C and the surface Sn on PtSn/C are associated with oxygenated species at all potentials, and that the nature and strength of the Sn-O bonds are potential dependent. The differences in the activity of the two catalysts for the MOR are due to the effects of alloying on the Pt electronic structure that inhibit the ability of the Pt to adsorb methanol and dissociate C-H bonds. The ability of PtSn/C to adsorb oxygen at low potentials enhances its activity for CO oxidation.

Mukerjee, S.; McBreen, J. [Brookhaven National Lab., Upton, NY (United States). Dept. of Applied Science

1999-02-01T23:59:59.000Z

139

Characterization of the molecular structure and mechanical properties of polymer surfaces and protein/polymer interfaces by sum frequency generation vibrational spectroscopy and atomic force microscopy  

SciTech Connect

Sum frequency generation (SFG) vibrational spectroscopy, atomic force microscopy (AFM), and other complementary surface-sensitive techniques have been used to study the surface molecular structure and surface mechanical behavior of biologically-relevant polymer systems. SFG and AFM have emerged as powerful analytical tools to deduce structure/property relationships, in situ, for polymers at air, liquid and solid interfaces. The experiments described in this dissertation have been performed to understand how polymer surface properties are linked to polymer bulk composition, substrate hydrophobicity, changes in the ambient environment (e.g., humidity and temperature), or the adsorption of macromolecules. The correlation of spectroscopic and mechanical data by SFG and AFM can become a powerful methodology to study and engineer materials with tailored surface properties. The overarching theme of this research is the interrogation of systems of increasing structural complexity, which allows us to extend conclusions made on simpler model systems. We begin by systematically describing the surface molecular composition and mechanical properties of polymers, copolymers, and blends having simple linear architectures. Subsequent chapters focus on networked hydrogel materials used as soft contact lenses and the adsorption of protein and surfactant at the polymer/liquid interface. The power of SFG is immediately demonstrated in experiments which identify the chemical parameters that influence the molecular composition and ordering of a polymer chain's side groups at the polymer/air and polymer/liquid interfaces. In general, side groups with increasingly greater hydrophobic character will be more surface active in air. Larger side groups impose steric restrictions, thus they will tend to be more randomly ordered than smaller hydrophobic groups. If exposed to a hydrophilic environment, such as water, the polymer chain will attempt to orient more of its hydrophilic groups to the surface in order to minimize the total surface energy. With an understanding of the structural and environmental parameters which govern polymer surface structure, SFG is then used to explore the effects of surface hydrophobicity and solvent polarity on the orientation and ordering of amphiphilic neutral polymers adsorbed at the solid/liquid interface. SFG spectra show that poly(propylene glycol) (PPG) and poly(ethylene glycol) (PEG) adsorb with their hydrophobic moieties preferentially oriented toward hydrophobic polystyrene surfaces. These same moieties, however, disorder when adsorbed onto a hydrophilic silica/water interface. Water is identified as a critical factor for mediating the orientation and ordering of hydrophobic moieties in polymers adsorbed at hydrophobic interfaces. The role of bulk water content and water vapor, as they influence hydrogel surface structure and mechanics, continues to be explored in the next series of experiments. A method was developed to probe the surface viscoelastic properties of hydroxylethyl methacrylate (HEMA) based contact lens materials by analyzing AFM force-distance curves. AFM analysis indicates that the interfacial region is dehydrated, relative to the bulk. Experiments performed on poly(HEMA+MA) (MA = methacrylic acid), a more hydrophilic copolymer with greater bulk water content, show even greater water depletion at the surface. SFG spectra, as well as surface energy arguments, suggest that the more hydrophilic polymer component (such as MA) is not favored at the air interface; this may explain anomalies in water retention at the hydrogel surface. Adsorption of lysozyme onto poly(HEMA+MA) was found to further reduce near-surface viscous behavior, suggesting lower surface water content. Lastly, protein adsorption is studied using a model polymer system of polystyrene covalently bound with a monolayer of bovine serum albumin. SFG results indicate that some amino acid residues in proteins adopt preferred orientations. SFG spectra also show that the phenyl rings of the bare polystyrene substrate in contact with air or

Koffas, Telly Stelianos

2004-05-15T23:59:59.000Z

140

Core Level Spectroscopies Surface Science and X-Ray Spectroscopy Group  

NLE Websites -- All DOE Office Websites (Extended Search)

Core Level Spectroscopy Creation and Decay of Core Holes Spectroscopic Techniques X-ray Photoelectron (XPS) X-ray Absorption (XAS) X-ray Emission (XES) Auger Electron (AES) Core holes are created by the ionization of a core electron in XPS and by excitation in XAS . The XPS and XAS final states are highly unstable and the core hole decays by non-radiant Auger relaxation (AES) or by radiant x-ray emission processes (XES). XPS and AES probe the unoccupied electronic stru cture, while XAS projects the unoccupied valence states of the system onto a particular atom. A brief description of the each of the different spectroscopies illustrated by schematic pictures of the creation and decay with data measured for N2 adsorbed on Ni(100) can be found by scrolling

Note: This page contains sample records for the topic "atomic absorption spectroscopy" 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

Communication: In search of four-atom chiral metal clusters  

Science Conference Proceedings (OSTI)

A combined study utilizing anion photoelectron spectroscopy and density functional theory was conducted to search for four-atom

Xinxing Zhang; Martin Tschurl; Evan Collins; Yi Wang; Qian Wang; Yawei Li; Qiang Sun; Puru Jena; Gerd Gantefoer; Ulrich Boesl

2013-01-01T23:59:59.000Z

142

Effects of sulfation level on the desulfation behavior of pre-sulfated Pt BaO/Al2O3 lean NOx trap catalysts: a combined H2 Temperature-Programmed Reaction, in-situ sulfur K-edge X-ray Absorption Near-Edge Spectroscopy, X-ray Photoelectron Spectroscopy, and Time-Resolved X-ray Diffraction Study  

SciTech Connect

Desulfation by hydrogen of pre-sulfated Pt(2wt%) BaO(20wt%)/Al2O3 with various sulfur loading (S/Ba = 0.12, 0.31 and 0.62) were investigated by combining H2 temperature programmed reaction (TPRX), x-ray photoelectron spectroscopy (XPS), in-situ sulfur K-edge x-ray absorption near-edge spectroscopy (XANES), and synchrotron time-resolved x-ray diffraction (TR-XRD) techniques. We find that the amount of H2S desorbed during the desulfation in the H2 TPRX experiments is not proportional to the amount of initial sulfur loading. The results of both in-situ sulfur K-edge XANES and TR-XRD show that at low sulfur loadings, sulfates were transformed to a BaS phase and remained in the catalyst, rather than being removed as H2S. On the other hand, when the deposited sulfur level exceeded a certain threshold (at least S/Ba = 0.31) sulfates were reduced to form H2S, and the relative amount of the residual sulfide species in the catalyst was much less than at low sulfur loading. Unlike samples with high sulfur loading (e.g., S/Ba = 0.62), H2O did not promote the desulfation for the sample with S/Ba of 0.12, implying that the formed BaS species originating from the reduction of sulfates at low sulfur loading are more stable to hydrolysis. The results of this combined spectroscopy investigation provide clear evidence to show that sulfates at low sulfur loadings are less likely to be removed as H2S and have a greater tendency to be transformed to BaS on the material, leading to the conclusion that desulfation behavior of Pt BaO/Al2O3 lean NOx trap catalysts is markedly dependent on the sulfation levels.

Kim, Do Heui; Szanyi, Janos; Kwak, Ja Hun; Wang, Xianqin; Hanson, Jonathan C.; Engelhard, Mark H.; Peden, Charles HF

2009-04-03T23:59:59.000Z

143

Atomic-Scale Investigation of Epitaxial Graphene Grown on 6H-SiC(0001) Using Scanning Tunneling Microscopy and Spectroscopy  

E-Print Network (OSTI)

. Typically, the atomic structures of the graphene were resolved at sample bias voltages below 0.5 V graphene continuously extended across four SiC bilayers, as confirmed by the line profile. A height .) 13346 J. Phys. Chem. C, Vol. 114, No. 31, 2010 Choi et al. #12;shaped protrusions at high bias voltage

Kim, Sehun

144

Atomic vapor laser isotope separation process  

DOE Patents (OSTI)

A laser spectroscopy system is utilized in an atomic vapor laser isotope separation process. The system determines spectral components of an atomic vapor utilizing a laser heterodyne technique. 23 figs.

Wyeth, R.W.; Paisner, J.A.; Story, T.

1990-08-21T23:59:59.000Z

145

Method for quantitative determination and separation of trace amounts of chemical elements in the presence of large quantities of other elements having the same atomic mass  

DOE Patents (OSTI)

Photoionization via autoionizing atomic levels combined with conventional mass spectroscopy provides a technique for quantitative analysis of trace quantities of chemical elements in the presence of much larger amounts of other elements with substantially the same atomic mass. Ytterbium samples smaller than 10 ng have been detected using an ArF* excimer laser which provides the atomic ions for a time-of-flight mass spectrometer. Elemental selectivity of greater than 5:1 with respect to lutetium impurity has been obtained. Autoionization via a single photon process permits greater photon utilization efficiency because of its greater absorption cross section than bound-free transitions, while maintaining sufficient spectroscopic structure to allow significant photoionization selectivity between different atomic species. Separation of atomic species from others of substantially the same atomic mass is also described.

Miller, C.M.; Nogar, N.S.

1982-09-02T23:59:59.000Z

146

X-ray absorption fine structure spectroscopic study of uranium nitrides  

Science Conference Proceedings (OSTI)

Uranium mononitride (UN), sesquinitride (U2N3) and dinitride (UN2) were characterized by extended X-Ray absorption fine structure spectroscopy. Analysis on UN indicate the presence of three uranium shells at distances of 3.46(3), 4.89(5) and 6.01(6) A and a nitrogen shell at a distance of 2.46(2) A . For U2N3, two absorbing uranium atoms at different crystallographic positions are present in the structure. One of the uranium atoms is surrounded by nitrogen atoms at 2.28(2) A and by uranium atoms at 3.66(4) and 3.95(4) A . The second type of uranium atom is surrounded by nitrogen atoms at 2.33(2) and 2.64(3) A and by uranium atoms at 3.66(4), 3.95(4) and 5.31(5) A . Results on UN2 indicate two uranium shells at 3.71(4) and 5.32(5) A and two nitrogen shells at 2.28(2).

Poineau, Frederic [University of Nevada, Las Vegas; Yeamans, Charles B. [University of California, Berkeley; Cerefice, Gary S. [University of Nevada, Las Vegas; Sattelberger, Alfred P [Argonne National Laboratory (ANL); Czerwinski, Ken R. [University of Nevada, Las Vegas

2012-01-01T23:59:59.000Z

147

Root Absorption  

NLE Websites -- All DOE Office Websites (Extended Search)

Root Absorption Root Absorption Name: Carolyn Location: N/A Country: N/A Date: N/A Question: MY Neice is doing a science fair project on plants. More specifically she needs to know if you water your flowering plants with colored water, does the flower change colors and if so, why? Replies: Dear Carolyn, Dyeing flowers works best on cut stems in water: http://youth.net/nsrc/sci/sci032.html#anchor598182 Title: The Effect Of Color On The Speed Of Dyeing Flowers Some rooted plants can change flower color by altering the soil pH: http://www.cahe.nmsu.edu/pubs/yard/1996/120996.html Sincerely, Anthony R. Brach This sounds like a good question for a science project. I think she should do the project first and get some data and then try to answer the question herself. If she can't figure it out, then she should look for some help.

148

Effects of Sulfation Level on the Desulfation Behavior of Presulfated Pt-BaO/Al2O3 Lean NOx Trap Catalysts: A Combined H2 Temperature-Programmed Reaction, in Situ Sulfur K-Edge X-ray Absorption Near-Edge Spectroscopy, X-ray Photoelectron Spectroscopy, and Time-Resolved X-ray Diffraction Study  

SciTech Connect

Desulfation by hydrogen of presulfated Pt (2 wt %)-BaO(20 wt %)/Al{sub 2}O{sub 3} with various sulfur loading (S/Ba = 0.12, 0.31, and 0.62) were investigated by combining H{sub 2} temperature programmed reaction (TPRX), X-ray photoelectron spectroscopy (XPS), in situ sulfur K-edge X-ray absorption near-edge spectroscopy (XANES), and synchrotron time-resolved X-ray diffraction (TR-XRD) techniques. We find that the amount of H{sub 2}S desorbed during the desulfation in the H{sub 2} TPRX experiments is not proportional to the amount of initial sulfur loading. The results of both in situ sulfur K-edge XANES and TR-XRD show that at low sulfur loadings, sulfates were transformed to a BaS phase and remained in the catalyst rather than being removed as H{sub 2}S. On the other hand, when the deposited sulfur level exceeded a certain threshold (at least S/Ba = 0.31) sulfates were reduced to form H{sub 2}S, and the relative amount of the residual sulfide species in the catalyst was much less than at low sulfur loading. Unlike samples with high sulfur loading (e.g., S/Ba = 0.62), H{sub 2}O did not promote the desulfation for the sample with S/Ba of 0.12, implying that the formed BaS species originating from the reduction of sulfates at low sulfur loading are more stable to hydrolysis. The results of this combined spectroscopy investigation provide clear evidence to show that sulfates at low sulfur loadings are less likely to be removed as H{sub 2}S and have a greater tendency to be transformed to BaS on the material, leading to the conclusion that desulfation behavior of Pt-BaO/Al{sub 2}O{sub 3} lean NO{sub x} trap catalysts is markedly dependent on the sulfation levels.

Kim, D.H.; Hanson, J.; Szanyi, J.; Kwak, J.H.; Wang, X.; Hanson, J.C.; Engelhard, M.; and Peden, C.H.F.

2009-04-30T23:59:59.000Z

149

Determining Relative f and d Orbital Contributions to M?Cl Covalency in MCl62– (M = Ti, Zr, Hf, U) and UOCl5 Using Cl K-Edge X-ray Absorption Spectroscopy and Time-Dependent Density Functional Theory  

SciTech Connect

Chlorine K-edge X-ray absorption spectroscopy (XAS) and ground-state and time-dependent hybrid density functional theory (DFT) were used to probe electronic structure for O{sub h}-MCl{sub 6}{sup 2-}(M = Ti, Zr, Hf, U) and C{sub 4v}-UOCl{sub 5}{sup -}, and to determine the relative contributions of valence 3d, 4d, 5d, 6d, and 5f orbitals in M-Cl bonding. Spectral interpretations were guided by time-dependent DFT calculated transition energies and oscillator strengths, which agree well with the experimental XAS spectra. The data provide new spectroscopic evidence for the involvement of both 5f and 6d orbitals in actinide-ligand bonding in UCl{sub 6}{sup 2-}. For the MCl{sub 6}{sup 2-}, where transitions into d orbitals of t{sub 2g} symmetry are spectroscopically resolved for all four complexes, the experimentally determined Cl 3p character per M-Cl bond increases from 8.3(4)% (TiCl{sub 6}{sup 2-}) to 10.3(5)% (ZrCl{sub 6}{sup 2-}), 12(1)% (HfCl{sub 6}{sup 2-}), and 26 18(1)% (UCl{sub 6}{sup 2-}). Chlorine K-edge XAS spectra of UOCl{sub 5}{sup -} provide additional insights into the transition assignments by 27 lowering the symmetry to C{sub 4v}, where five pre-edge transitions into both 5f and 6d orbitals are observed. For UCl{sub 6}{sup 2-}, the XAS data 28 suggest that orbital mixing associated with the U 5f orbitals is considerably lower than that of the U 6d orbitals. For both UCl{sub 6}{sup 2-}29 and UOCl{sub 5}{sup -}, the ground-state DFT calculations predict a larger 5f contribution to bonding than is determined experimentally. 30 These findings are discussed in the context of conventional theories of covalent bonding for d- and f-block metal complexes.

Minasian, Stefan G.; Keith, Jason M.; Batista, Enrique R.; Boland, Kevin S.; Clark, David L.; Conradson, Steven D.; Kozimor, Stosh A.; Martin, Richard L.; Schwarz, Daniel E.; Shuh, David K.; Wagner, Gregory L.; Wilkerson, Marianne P.; Wolfsberg, Laura E.; Yang, Ping

2012-03-09T23:59:59.000Z

150

X-ray absorption studies of battery materials  

SciTech Connect

X-ray absorption spectroscopy (XAS) is ideal for {ital in}{ital situ} studies of battery materials because both the probe and signal are penetrating x rays. The advantage of XAS being element specific permits investigation of the environment of a constituent element in a composite material. This makes it very powerful for studying electrode additives and corrosion of individual components of complex metal hydride alloys. The near edge part of the spectrum (XANES) provides information on oxidation state and site symmetry of the excited atom. This is particularly useful in study of corrosion and oxidation changes in cathode materials during charge/discharge cycle. Extended fine structure (EXAFS) gives structural information. Thus the technique provides both chemical and structural information. Since XAS probes only short range order, it can be applied to study of amorphous electrode materials and electrolytes. This paper discusses advantages and limitations of the method, as well as some experimental aspects.

McBreen, J.

1996-10-01T23:59:59.000Z

151

Nuclear effects in atomic transitions  

E-Print Network (OSTI)

Atomic electrons are sensitive to the properties of the nucleus they are bound to, such as nuclear mass, charge distribution, spin, magnetization distribution, or even excited level scheme. These nuclear parameters are reflected in the atomic transition energies. A very precise determination of atomic spectra may thus reveal information about the nucleus, otherwise hardly accessible via nuclear physics experiments. This work reviews theoretical and experimental aspects of the nuclear effects that can be identified in atomic structure data. An introduction to the theory of isotope shifts and hyperfine splitting of atomic spectra is given, together with an overview of the typical experimental techniques used in high-precision atomic spectroscopy. More exotic effects at the borderline between atomic and nuclear physics, such as parity violation in atomic transitions due to the weak interaction, or nuclear polarization and nuclear excitation by electron capture, are also addressed.

Pálffy, Adriana

2011-01-01T23:59:59.000Z

152

Atomic History  

Science Conference Proceedings (OSTI)

... These Data Centers, one on Atomic Energy Levels and one on Atomic Transition ... After a few years Kessler went on to higher management at NIST. ...

2010-10-05T23:59:59.000Z

153

Iron Absorption  

NLE Websites -- All DOE Office Websites (Extended Search)

Iron Absorption Iron Absorption Name: Mary Location: N/A Country: N/A Date: N/A Question: I wrote before to Steve and got a answer back. I would like more information. The cirmcustances were that I first had anaemia and then I went for a gastroscopy. The results of which were I had insufficient acid been produced in the stomach. I was told that acid was nessary for the absorbion of iron and it was because of this that I became anaemic. I was told to eat plently of red meat not too many vegetables. Is there any other information you can give me? Replies: It is very difficult to say for sure without seeing you chart and I am not your doctor. But it sounds to me like you are deficient in the vitamin B12. In your stomach you have 3 basic types of cells. One is called chief cells which secrete the precursor of the enzyme pepsin which begins the breakdown of protein. Another is called the parietal cells which secrete your stomach acid and a substance called intrinsic factor. Now-switch to your bone marrow which is where your red blood cells are made. In order for your red blood cells to mature in the bone marrow, vitamin B12 is necessary. B12 can only be obtained from animal food sources such as meat, milk and eggs. Unfortunately, B12 cannot be absorbed in the stomach without intrinsic factor. If there is sufficient B12 present in the diet, it can be stored in the liver. If you aren't eating enough animal sources your B12 will be taken from your liver until you run out. You could also be deficient in intrinsic factor. So while the outcome is anemia (not enough red blood cells) the problem could be from a few different things. Follow your doctor's recommendations and eat more sources of B12

154

Infrared absorption measurements of the kinetics of Cl atom reactions with C{sub 3}H{sub n} (n=4,6) unsaturated hydrocarbons between 300-850 K  

Science Conference Proceedings (OSTI)

The reaction of chlorine (Cl) atoms with the unsaturated C{sub 3}H{sub n} where n=4,6, hydrocarbons propylene, allene, and methyl acetylene have been uninvestigated as a function of temperature and pressure.

Farrell, J.T.; Pilgrim, J.S.; Taatjes, C.A.

1997-08-01T23:59:59.000Z

155

Soft X-ray Spectroscopy Study of the Electronic Structure of Oxidized and Partially Oxidized Magnetite Nanoparticles  

SciTech Connect

The crystal structure of magnetite nanoparticles may be transformed to maghemite by complete oxidation, but under many relevant conditions the oxidation is partial, creating a mixed-valence material with structural and electronic properties that are poorly characterized. We used X-ray diffraction, Fe K-edge extended X-ray absorption fine structure (EXAFS) spectroscopy, and soft X-ray absorption and emission spectroscopy to characterize the products of oxidizing uncoated and oleic acid-coated magnetite nanoparticles in air. The oxidization of uncoated magnetite nanoparticles creates a material that is structurally and electronically indistinguishable from maghemite. By contrast, while oxidized oleic acid-coated nanoparticles are also structurally indistinguishable from maghemite, Fe L-edge spectroscopy revealed the presence of interior reduced iron sites even after a 2-year period. We used X-ray emission spectroscopy at the O K-edge to study the valence bands (VB) of the iron oxide nanoparticles, using resonant excitation to remove the contributions from oxygen atoms in the ligands and from low-energy excitations that obscured the VB edge. The bonding in all nanoparticles was typical of maghemite, with no detectable VB states introduced by the long-lived, reduced-iron sites in the oleic acid-coated sample. However, O K-edge absorption spectroscopy observed a 0.2 eV shift in the position of the lowest unoccupied states in the coated sample, indicating an increase in the semiconductor band gap relative to bulk stoichiometric maghemite that was also observed by optical absorption spectroscopy. The results show that the ferrous iron sites within ferric iron oxide nanoparticles coated by an organic ligand can persist under ambient conditions with no evidence of a distinct interior phase and can exert an effect on the global electronic and optical properties of the material. This phenomenon resembles the band gap enlargement caused by electron accumulation in the conduction band of TiO2.

Gilbert, Benjamin; Katz, Jordan E.; Denlinger, Jonathan D.; Yin, Yadong; Falcone, Roger; Waychunas, Glenn A.

2010-10-24T23:59:59.000Z

156

NIST: Atomic Spectroscopy - Physics Lab NRC Associateships  

Science Conference Proceedings (OSTI)

National Research Council Postdoctoral Fellowships. •$63,000 annual salary; relocation expenses; health benefits. • Applications ...

2010-10-05T23:59:59.000Z

157

NIST: Atomic Spectroscopy Group - Joseph Tan  

Science Conference Proceedings (OSTI)

... award). 1986, MS Physics, University of Washington, Seattle. 1985-1986, University of Washington Arts and Sciences Fellow. ...

2011-02-09T23:59:59.000Z

158

PHOTOELECTRON SPECTROSCOPY OF HEAVY ATOMS AND MOLECULES  

E-Print Network (OSTI)

1120 (1962). pressure data for SnS. Vapor C. Sirayama, Y.Molecule Geo GeS GeSe GeTe Sns SnSe SnTe v"(cm ) a T(°C) N lobtained the GeS, GeSe, SnS, and SnSe samples from Research

White, M.G.

2010-01-01T23:59:59.000Z

159

PHOTOELECTRON SPECTROSCOPY OF HEAVY ATOMS AND MOLECULES  

E-Print Network (OSTI)

of timing measurements at SSRL, see K. M. Monahan and V.radiation available at SSRL to measure photoelectron angularfor the 8° beam line at SSRL eaploying In and Al windows.

White, M.G.

2010-01-01T23:59:59.000Z

160

NIST: Atomic Spectroscopy Group - Optogalvanic Reference ...  

Science Conference Proceedings (OSTI)

... Changes in the lamp current that occur when a resonance is achieved are detected by a drop in voltage across the lamp's ballast resistor with a lock ...

2010-10-05T23:59:59.000Z

Note: This page contains sample records for the topic "atomic absorption spectroscopy" 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

High resolution laser spectroscopy of cesium and rubidium molecules with optically induced coherence  

E-Print Network (OSTI)

This work is devoted to the study of the quantum coherent effects in diatomic molecular systems by using high resolution laser spectroscopy. In particular, we have studied the rubidium diatomic molecular gaseous medium's absorption spectrum with high resolution single mode laser spectroscopy. The derived electronic and rotational vibrational constants were used in the backward Raman amplification experiment of Rb diatomic molecule. Both experimental results and theoretical calculation confirms that there is strong backward directionally dependent radiation. This effect can further be utilized in remote detection of chemical material. In the saturated spectroscopy experiment of the cesium diatomic molecule, long-lived ground state coherence was observed. The coherence would decay at a rate less than the natural life time of the excited states, which indicates great possibility for performing the quantum optics experiments previously performed in atomic systems only. Electromagnetically induced transparency has been observed in many atomic systems for many years, while it has been seldom realized in molecular systems. In our experiment of electromagnetically induced transparency in cesium diatomic molecules, we utilized Ã?Â? energy levels, and observed subnatural linewidth. This is the first time to realize a Ã?Â? type EIT in a molecular ensemble. This experiment will lead to many other experiments of quantum effects in a molecular system, such like magnetic optical rotation, light storage in ensemble of molecules. Magnetically induced chirality in an atomic ensemble is also investigated in my research.

Chen, Hui

2006-08-01T23:59:59.000Z

162

Oxygen Absorption in Cooling Flows  

E-Print Network (OSTI)

The inhomogeneous cooling flow scenario predicts the existence of large quantities of gas in massive elliptical galaxies, groups, and clusters that have cooled and dropped out of the flow. Using spatially resolved, deprojected X-ray spectra from the ROSAT PSPC we have detected strong absorption over energies ~0.4-0.8 keV intrinsic to the central ~1 arcmin of the galaxy, NGC 1399, the group, NGC 5044, and the cluster, A1795. These systems have amongst the largest nearby cooling flows in their respective classes and low Galactic columns. Since no excess absorption is indicated for energies below ~0.4 keV the most reasonable model for the absorber is warm, collisionally ionized gas with T=10^{5-6} K where ionized states of oxygen provide most of the absorption. Attributing the absorption only to ionized gas reconciles the large columns of cold H and He inferred from Einstein and ASCA with the lack of such columns inferred from ROSAT, and also is consistent with the negligible atomic and molecular H inferred from HI, and CO observations of cooling flows. The prediction of warm ionized gas as the product of mass drop-out in these and other cooling flows can be verified by Chandra, XMM, and ASTRO-E.

David A. Buote

2000-01-19T23:59:59.000Z

163

Spectroscopy (XSD) | Advanced Photon Source  

NLE Websites -- All DOE Office Websites (Extended Search)

Useful Links Useful Links Spectroscopy Group (X-ray Science Division) The Spectroscopy Group operates the Sector-20 bending magnet (BM) and insertion device (ID) beamlines, and the bending magnet beamline at Sector-9. Beamlines 20-ID (Undulator A) Supported Techniques ·X-ray absorption fine structure (XAFS) ·Surface Diffraction ·X-ray Raman Scattering ·Resonant X-ray Emission Spectroscopy ·Micro-XAFS ·Confocal X-ray microscopy ·Micro-fluorescence ·Micro-XRD Discipline ·Material Science ·Environmental Science ·Chemistry Click [20-ID] under "Beamlines" above for technical information 20-BM Supported Techniques X-ray absorption fine structure (XAFS) Micro-fluorescence Micro-XAFS Micro-diffraction Discipline ·Material Science ·Environmental Science ·Chemistry Click [20-BM] under "Beamlines" above for technical information

164

MOAS: An Absorption Laser Spectrometer for Sensitive and Local Monitoring of Tropospheric OH and Other Trace Gases  

Science Conference Proceedings (OSTI)

Hydroxyl radical (OH) multipass absorption spectroscopy (MOAS) is a laser optical method for the absolute and in situ monitoring of tropospheric OH with high spatial and temporal resolution. This technique is based on direct absorption ...

W. Armerding; M. Spiekermann; J. Walter; F. J. Comes

1995-10-01T23:59:59.000Z

165

High resolution scanning tunnelling microscopy and extended x-ray-absorption fine structure study of the (533) silicide structure on Cu(001)  

E-Print Network (OSTI)

Using low energy electron diffraction (LEED), scanning tunnelling microscopy (STM) and x-ray absorption spectroscopy (XAS) techniques, we have studied the first steps of silicon adsorption onto Cu (001) single crystal substrate. For low coverage (~ 0.5 ML) and after annealing at 100{\\deg}C, STM images and LEED patterns reveal the formation of an ordered quasi commensurate superstructure. From a quantitative analysis of XAS data, we extract the Si-Cu distance and detail the local atomic arrangement of the structure.

B. Lalmi; M. Chorro; R. Belkhou

2013-08-09T23:59:59.000Z

166

Unraveling EXAFS spectroscopy  

SciTech Connect

The past several years have witnessed the emergence of Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy from an esoteric technique to a widely available structural spectroscopic tool. Several in-depth review articles and books are available on the subject, but some aspects of theory or data reduction may be beyond the scope or need of the average chemist. In this article the authors will try to reduce the mystique surrounding EXAFS and clarify the terminology and concepts in the EXAFS literature. They will concentrate primarily on theory and data analysis and conclude with a few applications.

Fay, M.J.; Proctor, A.; Hoffman, D.P.; Hercules, D.M

1988-11-01T23:59:59.000Z

167

The Atomic AXAFS and XANES Techniques as Applied to Heterogeneous Catalysis and Electrocatalysis  

Science Conference Proceedings (OSTI)

X-Ray absorption spectroscopy (XAFS) is an attractive in situ and in operando technique. In recent years, the more conventional extended X-ray absorption fine structure (EXAFS) data analysis technique has been complemented by two newer analysis methods: the 'atomic' XAFS (AXAFS) technique, which analyzes the scattering from the absorber atom itself, and the {Delta}{mu} XANES technique, which uses a difference method to isolate the changes in the X-ray absorption near edge structure (XANES) due to adsorbates on a metal surface. With AXAFS it is possible to follow the electronic effect a support has on a metal particle; with {Delta}{mu} XANES it is possible to determine the adsorbate, the specific adsorption sites and adsorbate coverage on a metal catalyst. This unprecedented new information helps a great deal to unravel the complex kinetic mechanisms operating in working reactors or fuelcell systems. The fundamental principles and methodology for applying the AXAFS and {Delta}{mu} XANES techniques are given here, and then specific applications are summarized, including H adsorption on supported Pt in the gas phase, wateractivation at a Pt cathode and methanol oxidation at a Pt anode in an electrochemical cell, sulfur oxidation on Pt, and oxygenreduction on a Au/SnO{sub x} cathode. Finally, the future outlook for time and/or space resolved applications of these techniques is contemplated.

Ramaker, D.; Koningsberger, D

2010-01-01T23:59:59.000Z

168

Ramsey spectroscopy with squeezed light  

E-Print Network (OSTI)

Traditional Ramsey spectroscopy has the frequency resolution $2\\pi/T$, where $T$ is the time separation between two light fields. Using squeezed states and two-atom excitation joint detection, we present a new scheme achieving a higher resolution $\\pi/T$. We use two mode squeezed light which exhibits strong entanglement.

Qu, Kenan

2013-01-01T23:59:59.000Z

169

Using in situ X-ray absorption spectroscopy to study the local structure and oxygen ion conduction mechanism in (La{sub 0.6}Sr{sub 0.4})(Co{sub 0.2}Fe{sub 0.8})O{sub 3-{delta}}  

SciTech Connect

To study the local structure and oxygen ion conduction mechanism in (La{sub 0.6}Sr{sub 0.4})(Co{sub 0.2}Fe{sub 0.8})O{sub 3-{delta}} (LSCF) as a function of the oxygen partial pressure (P(O{sub 2})), in situ the Co and Fe K-edge X-ray absorption spectroscopy (XAS) was measured at elevated temperatures of 900 and 1000 K. The reduction of the Co and Fe valence, i.e., the oxygen content (3-{delta}) in LSCF, followed the change of P(O{sub 2}) from 1 to 10{sup -4} atm during{approx}4000 s. The quantitative analysis of the X-ray absorption near edge structure (XANES) and the extended X-ray absorption fine structure (EXAFS) indicated that the Fe valence was higher than the Co valence at oxidative condition ({delta} Almost-Equal-To 0) in LSCF. Whereas the Co valence decreased more than the Fe valence after reduction of P(O{sub 2}) at both 900 and 1000 K. From the relaxation plots of the valence and the oxygen content (3-{delta}) for Co and Fe after changing P(O{sub 2}), we successfully determined D{sub chem} and E{sub a} of an oxygen ion migration around Co and Fe in LSCF. A structural model with and without oxygen vacancies and an oxygen ion conduction mechanism for LSCF are proposed based on these results. - Graphical abstract: A structural model with and without oxygen vacancies, and the oxygen ion conduction mechanism of LSCF were speculated. In other words, oxygen vacancies would form more preferentially around Co than Fe from the results of in situ XAS analysis during reduction, and oxygen ions needs to pass through at the vicinity of Fe from the results of D{sub chem} and E{sub a}. Highlights: Black-Right-Pointing-Pointer Study of the oxygen ion conduction mechanism in (La{sub 0.6}Sr{sub 0.4})(Co{sub 0.2}Fe{sub 0.8})O{sub 3-{delta}} (LSCF). Black-Right-Pointing-Pointer Using in situ X-ray absorption for study of valence and oxygen diffusion coefficient. Black-Right-Pointing-Pointer The oxygen vacancies should be preferentially localized around Co in LSCF. Black-Right-Pointing-Pointer The values of the dynamics parameters for Co and Fe are close to each other.

Itoh, Takanori, E-mail: tknitoh@seimichemical.co.jp [AGC SeimiChemical Co., Ltd., 3-2-10 Chigasaki, Chigasaki City, Kanagawa 253-8585 (Japan); Nakayama, Masanobu [Department of Materials Science and Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya-city, Aichi 466-8555 (Japan)

2012-08-15T23:59:59.000Z

170

Determination of Atomic Data Pertinent to the Fusion Energy Program  

Science Conference Proceedings (OSTI)

We summarize progress that has been made on the determination of atomic data pertinent to the fusion energy program. Work is reported on the identification of spectral lines of impurity ions, spectroscopic data assessment and compilations, expansion and upgrade of the NIST atomic databases, collision and spectroscopy experiments with highly charged ions on EBIT, and atomic structure calculations and modeling of plasma spectra.

None

2013-06-11T23:59:59.000Z

171

Study of clusters using negative ion photodetachment spectroscopy  

SciTech Connect

The weak van der Waals interaction between an open-shell halogen atom and a closed-shell atom or molecule has been investigated using zero electron kinetic energy (ZEKE) spectroscopy. This technique is also applied to study the low-lying electronic states in GaAs and GaAs{sup {minus}}. In addition, the spectroscopy and electron detachment dynamics of several small carbon cluster anions are studied using resonant multiphoton detachment spectroscopy.

Zhao, Yuexing

1995-12-01T23:59:59.000Z

172

Energy Basics: Absorption Cooling  

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

cooling. Other potential heat sources include propane, solar-heated water, or geothermal-heated water. Although mainly used in industrial or commercial settings, absorption...

173

Solar absorption surface panel  

DOE Patents (OSTI)

A composite metal of aluminum and nickel is used to form an economical solar absorption surface for a collector plate wherein an intermetallic compound of the aluminum and nickel provides a surface morphology with high absorptance and relatively low infrared emittance along with good durability.

Santala, Teuvo J. (Attleboro, MA)

1978-01-01T23:59:59.000Z

174

Transition from LEDCOP to ATOMIC  

SciTech Connect

This paper discusses the development of the ATOMIC code, a new low to mid Z opacity code, which will replace the current Los Alamos low Z opacity code LEDCOP. The ATOMIC code is based on the FINE code, long used by the Los Alamos group for spectral comparisons in local thermodynamic equilibrium (LTE) and for non-LTE calculations, both utilizing the extensive databases from the atomic physics suite of codes based on the work of R.D. Cowan. Many of the plasma physics packages in LEDCOP, such as line broadening and free-free absorption, are being transferred to the new ATOMIC code. A new equation of state (EOS) model is being developed to allow higher density calculations than were possible with either the FINE or LEDCOP codes. Extensive modernization for both ATOMIC and the atomic physics code suites, including conversion to Fortran 90 and parallelization, are underway to speed up the calculations and to allow the use of expanded databases for both the LTE opacity tables and the non-LTE calculations. Future plans for the code will be outlined, including considerations for new generation opacity tables.

Magee, N. H. (Norman H.); Abdallah, J. (Joseph); Colgan, J. (James); Hakel, P. (Peter); Kilcrease, D. P. (David P.); Mazevet, S. (Stephane); Sherrill, M. E. (Manolo E.); Fontes, C. J. (Christopher J.); Zhang, H. (Honglin)

2004-01-01T23:59:59.000Z

175

Glossary Term - Atomic Number  

NLE Websites -- All DOE Office Websites (Extended Search)

Particle Previous Term (Alpha Particle) Glossary Main Index Next Term (Avogadro's Number) Avogadro's Number Atomic Number Silver's atomic number is 47 The atomic number is equal to...

176

Theoretical Atomic Physics code development IV: LINES, A code for computing atomic line spectra  

SciTech Connect

A new computer program, LINES, has been developed for simulating atomic line emission and absorption spectra using the accurate fine structure energy levels and transition strengths calculated by the (CATS) Cowan Atomic Structure code. Population distributions for the ion stages are obtained in LINES by using the Local Thermodynamic Equilibrium (LTE) model. LINES is also useful for displaying the pertinent atomic data generated by CATS. This report describes the use of LINES. Both CATS and LINES are part of the Theoretical Atomic PhysicS (TAPS) code development effort at Los Alamos. 11 refs., 9 figs., 1 tab.

Abdallah, J. Jr.; Clark, R.E.H.

1988-12-01T23:59:59.000Z

177

Method and apparatus for optoacoustic spectroscopy  

DOE Patents (OSTI)

A method and apparatus that significantly increases the sensitivity and flexibility of laser optoacoustic spectroscopy, with reduced size. With the method, it no longer is necessary to limit the use of laser optoacoustic spectroscopy to species whose absorption must match available laser radiation. Instead, "doping" with a relatively small amount of an optically absorbing gas yields optoacoustic signatures of nonabsorbing materials (gases, liquids, solids, and aerosols), thus significantly increasing the sensitivity and flexibility of optoacoustic spectroscopy. Several applications of this method are demonstated and/or suggested.

Amer, Nabil M. (Berkeley, CA)

1979-01-01T23:59:59.000Z

178

ARM - Measurement - Aerosol absorption  

NLE Websites -- All DOE Office Websites (Extended Search)

absorption absorption ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Aerosol absorption The process in which radiation energy is retained by aerosols. Categories Aerosols Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments AOS : Aerosol Observing System CSPHOT : Cimel Sunphotometer IAP : In-situ Aerosol Profiles (Cessna Aerosol Flights) PSAP : Particle Soot Absorption Photometer PASS : Photoacoustic Soot Spectrometer External Instruments OMI : Ozone Monitoring Instrument

179

Absorption heat pump system  

DOE Patents (OSTI)

The efficiency of an absorption heat pump system is improved by conducting liquid from a second stage evaporator thereof to an auxiliary heat exchanger positioned downstream of a primary heat exchanger in the desorber of the system.

Grossman, Gershon (Oak Ridge, TN)

1984-01-01T23:59:59.000Z

180

Absorption heat pump system  

DOE Patents (OSTI)

The efficiency of an absorption heat pump system is improved by conducting liquid from a second stage evaporator thereof to an auxiliary heat exchanger positioned downstream of a primary heat exchanger in the desorber of the system.

Grossman, G.

1982-06-16T23:59:59.000Z

Note: This page contains sample records for the topic "atomic absorption spectroscopy" 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

TENDER ENERGY X-RAY ABSORPTION  

NLE Websites -- All DOE Office Websites (Extended Search)

TENDER ENERGY X-RAY ABSORPTION TENDER ENERGY X-RAY ABSORPTION SPECTROSCOPY (TES) Project Team: S. Bare 1,2 , J. Brandes 3 , T. Buonassisi 4 , J. Chen 5,2 , M. Croft 6 , E. DiMasi 7 , A. Frenkel 8,2 , D. Hesterberg 9 , S. Hulbert 7,2 , S. Khalid 7 , S. Myneni 10 , P. Northrup 7,11 , E.T. Rasbury 11 , B. Ravel 12 , R. Reeder 11 , J. Rodriguez 7,2 , D. Sparks 5,13 , V. Stojanoff 7 , G. Waychunas 14 1 UOP LLC, 2 Synchrotron Catalysis Consortium, 3 Skidaway Inst. of Oceanography, 4 MIT Laboratory for Photovoltaics Research, 5 Univ. of Delaware, 6 Rutgers Univ., 7 Brookhaven National Lab, 8 Yeshiva Univ., 9 North Carolina State Univ., 10 Princeton Univ., 11 Stony Brook Univ., 12 NIST, 13 Delaware Environmental Inst., 14 Lawrence Berkeley National Lab TECHNIQUES: High performance and in-situ X-ray absorption spectroscopy and spatially-resolved XAS of

182

Solar selective absorption coatings  

DOE Patents (OSTI)

A new class of solar selective absorption coatings are disclosed. These coatings comprise a structured metallic overlayer such that the overlayer has a sub-micron structure designed to efficiently absorb solar radiation, while retaining low thermal emissivity for infrared thermal radiation. A sol-gel layer protects the structured metallic overlayer from mechanical, thermal, and environmental degradation. Processes for producing such solar selective absorption coatings are also disclosed.

Mahoney, Alan R. (Albuquerque, NM); Reed, Scott T. (Albuquerque, NM); Ashley, Carol S. (Albuquerque, NM); Martinez, F. Edward (Horseheads, NY)

2004-08-31T23:59:59.000Z

183

Solar selective absorption coatings  

DOE Patents (OSTI)

A new class of solar selective absorption coatings are disclosed. These coatings comprise a structured metallic overlayer such that the overlayer has a sub-micron structure designed to efficiently absorb solar radiation, while retaining low thermal emissivity for infrared thermal radiation. A sol-gel layer protects the structured metallic overlayer from mechanical, thermal, and environmental degradation. Processes for producing such solar selective absorption coatings are also disclosed.

Mahoney, Alan R. (Albuquerque, NM); Reed, Scott T. (Albuquerque, NM); Ashley, Carol S. (Albuquerque, NM); Martinez, F. Edward (Horseheads, NY)

2003-10-14T23:59:59.000Z

184

Optical absorption measurement system  

DOE Patents (OSTI)

The system of the present invention contemplates a non-intrusive method for measuring the temperature rise of optical elements under high laser power optical loading to determine the absorption coefficient. The method comprises irradiating the optical element with a high average power laser beam, viewing the optical element with an infrared camera to determine the temperature across the optical element and calculating the absorption of the optical element from the temperature.

Draggoo, V.G.; Morton, R.G.; Sawicki, R.H.; Bissinger, H.D.

1986-09-17T23:59:59.000Z

185

Optical absorption measurement system  

DOE Patents (OSTI)

The system of the present invention contemplates a non-intrusive method for measuring the temperature rise of optical elements under high laser power optical loading to determine the absorption coefficient. The method comprises irradiating the optical element with a high average power laser beam, viewing the optical element with an infrared camera to determine the temperature across the optical element and calculating the absorption of the optical element from the temperature.

Draggoo, Vaughn G. (Livermore, CA); Morton, Richard G. (San Diego, CA); Sawicki, Richard H. (Pleasanton, CA); Bissinger, Horst D. (Livermore, CA)

1989-01-01T23:59:59.000Z

186

AAS, see Atomic absorption spectrometry Acanthes lanceolata, 138  

E-Print Network (OSTI)

sources of petroleum is perceived as a risk to our national welfare. However the need for new, sustainable energy sources that minimize greenhouse gas emissions as is the case with petroleum refining, with the effect of enhancing the cost

Pitt, Robert E.

187

High-Pressure Evolution of Fe2O3 Electronic Structure Revealed by X-ray Absorption  

SciTech Connect

We report the first high pressure measurement of the Fe K-edge in hematite (Fe{sub 2}O{sub 3}) by X-ray absorption spectroscopy in partial fluorescence yield geometry. The pressure-induced evolution of the electronic structure as Fe{sub 2}O{sub 3} transforms from a high-spin insulator to a low-spin metal is reflected in the x-ray absorption pre-edge. The crystal field splitting energy was found to increase monotonically with pressure up to 48 GPa, above which a series of phase transitions occur. Atomic multiplet, cluster diagonalization, and density-functional calculations were performed to simulate the pre-edge absorption spectra, showing good qualitative agreement with the measurements. The mechanism for the pressure-induced phase transitions of Fe{sub 2}O{sub 3} is discussed and it is shown that ligand hybridization significantly reduces the critical high-spin/low-spin gap pressure.

Kao, Chi-Chang

2011-08-12T23:59:59.000Z

188

High-Precision, High-Resolution Measurements of Absorption in the Oxygen A-Band  

Science Conference Proceedings (OSTI)

Issues arising in the application of high-resolution, high-precision spectroscopy to remote sensing are discussed in the context of deriving surface pressure from absorption in the O2 A-band. This application requires spectral resolution ...

D. M. O’Brien; S. A. English; Grant Da Costa

1997-02-01T23:59:59.000Z

189

Seven-effect absorption refrigeration  

DOE Patents (OSTI)

A seven-effect absorption refrigeration cycle is disclosed utilizing three absorption circuits. In addition, a heat exchanger is used for heating the generator of the low absorption circuit with heat rejected from the condenser and absorber of the medium absorption circuit. A heat exchanger is also provided for heating the generator of the medium absorption circuit with heat rejected from the condenser and absorber of the high absorption circuit. If desired, another heat exchanger can also be provided for heating the evaporator of the high absorption circuit with rejected heat from either the condenser or absorber of the low absorption circuit.

DeVault, Robert C. (Knoxville, TN); Biermann, Wendell J. (Fayetteville, NY)

1989-01-01T23:59:59.000Z

190

Seven-effect absorption refrigeration  

DOE Patents (OSTI)

A seven-effect absorption refrigeration cycle is disclosed utilizing three absorption circuits. In addition, a heat exchanger is used for heating the generator of the low absorption circuit with heat rejected from the condenser and absorber of the medium absorption circuit. A heat exchanger is also provided for heating the generator of the medium absorption circuit with heat rejected from the condenser and absorber of the high absorption circuit. If desired, another heat exchanger can also be provided for heating the evaporator of the high absorption circuit with rejected heat from either the condenser or absorber of the low absorption circuit. 1 fig.

DeVault, R.C.; Biermann, W.J.

1989-05-09T23:59:59.000Z

191

Article Carbene Spin Multiplicity in Solution Probed Using Time-Resolved EPR Spectroscopy  

E-Print Network (OSTI)

Abstract. Time-resolved (CW) EPR spectroscopy at X-band has been used to detect free radicals created by H-atom abstraction reactions of photochemically generated carbenes in n-hexadecane solutions at room temperature. Three different carbenes were studied, formed via loss of nitrogen after photo-excitation of a substituted biphenyl diazo precursor. The TREPR signals from two different alkyl radicals and the benzylic-type radical from the carbene are detected for two of the three diazo substrates. The radicals were unambiguously identified by spectral simulation using literature parameters (g-factors and hyperfine coupling constants). Previous transient optical absorption spectroscopy experiments have concluded that these two carbenes have triplet ground states, which is confirmed by the low field emissive, high field absorptive phase of the TREPR signals reported here. The spectra are strongly spin polarized by the Radical Pair Mechanism of CIDEP, and their overall intensities track with the measured quantum yields for carbene production. A third substrate, known to react via a concerted Wolff reaction or excited state rearrangement via a singlet state, showed no TREPR signal, as expected. Reactions run in acetonitrile, where the spin multiplicity is reversed to give a singlet ground state, did not lead to detectable TREPR signals for all three substrates. The observations are consistent with previously published laser flash photolysis results.

Jin Wang; Natalia V. Lebedeva; Matthew S. Platz; Malcolm D. E. Forbes; J. Mex; Chem Soc; Sociedad Química De México; Dedicated Ernest; L. Eliel; A Scholar

2009-01-01T23:59:59.000Z

192

Laser-induced breakdown spectroscopy as a diagnostic tool for coal fines.  

E-Print Network (OSTI)

??Laser Induced Breakdown Spectroscopy (LIBS) is a technique that uses a laser, to focus down and atomize a sample of desired material. Focusing of the… (more)

Aurelio, I. Andrew.

2005-01-01T23:59:59.000Z

193

Atomic magnetometer  

SciTech Connect

An atomic magnetometer is disclosed which uses a pump light beam at a D1 or D2 transition of an alkali metal vapor to magnetically polarize the vapor in a heated cell, and a probe light beam at a different D2 or D1 transition to sense the magnetic field via a polarization rotation of the probe light beam. The pump and probe light beams are both directed along substantially the same optical path through an optical waveplate and through the heated cell to an optical filter which blocks the pump light beam while transmitting the probe light beam to one or more photodetectors which generate electrical signals to sense the magnetic field. The optical waveplate functions as a quarter waveplate to circularly polarize the pump light beam, and as a half waveplate to maintain the probe light beam linearly polarized.

Schwindt, Peter (Albuquerque, NM); Johnson, Cort N. (Albuquerque, NM)

2012-07-03T23:59:59.000Z

194

Atomic layer deposition of ZnO on ultralow-density nanoporous silica aerogel monoliths  

Science Conference Proceedings (OSTI)

We report on atomic layer deposition of an ? 2 -nm-thick ZnO layer on the inner surface of ultralow-density ( ? 0.5 % of the full density) nanoporoussilica aerogel monoliths with an extremely large effective aspect ratio of ? 10 5 (defined as the ratio of the monolith thickness to the average pore size). The resultant monoliths are formed by amorphous- SiO 2 core/wurtzite-ZnO shell nanoparticles which are randomly oriented and interconnected into an open-cell network with an apparent density of ? 3 % and a surface area of ? 10 0 m 2 g ? 1 . Secondary ion mass spectrometry and high-resolution transmission electron microscopy imaging reveal excellent uniformity and crystallinity of ZnO coating. Oxygen K -edge and Zn L 3 -edge soft x-ray absorption near-edge structure spectroscopy shows broadened O p - as well as Zn s - and d -projected densities of states in the conduction band.

S. O. Kucheyev; J. Biener; Y. M. Wang; T. F. Baumann; K. J. Wu; T. van Buuren; A. V. Hamza; J. H. Satcher Jr.; J. W. Elam; M. J. Pellin

2005-01-01T23:59:59.000Z

195

Polaron Absorption for Photovoltaic Energy Conversion in a Manganite-titanate pn Heterojunction  

Science Conference Proceedings (OSTI)

The relation among structure, electric transport, and photovoltaic effect is investigated for a pn heterojunction with strong correlation interactions. A perovskite interface is chosen as a model system consisting of the p-doped strongly correlated manganite Pr{sub 0.64}Ca{sub 0.36}MnO{sub 3} (PCMO) and the n-doped titanate SrTi{sub 1-y}Nb{sub y}O{sub 3} (y = 0.002 and 0.01). High-resolution electron microscopy and spectroscopy reveal a nearly dislocation-free, epitaxial interface and give insight into the local atomic and electronic structure. The presence of a photovoltaic effect under visible light at room temperature suggests the existence of mobile excited polarons within the band-gap-free PCMO absorber. The temperature-dependent rectifying current-voltage characteristics prove to be mainly determined by the presence of an interfacial energy spike in the conduction band and are affected by the colossal electroresistance effect. From the comparison of photocurrents and spatiotemporal distributions of photogenerated carriers (deduced from optical absorption spectroscopy), we discuss the range of the excited polaron diffusion length.

Saucke G.; Zhu Y.; Norpoth, J.; Jooss, C.; Su, D.

2012-04-20T23:59:59.000Z

196

Observation of relativistic antihydrogen atoms  

DOE Green Energy (OSTI)

An observation of relativistic antihydrogen atoms is reported in this dissertation. Experiment 862 at Fermi National Accelerator Laboratory observed antihydrogen atoms produced by the interaction of a circulating beam of high momentum (3 < p < 9 GeV/c) antiprotons and a jet of molecular hydrogen gas. Since the neutral antihydrogen does not bend in the antiproton source magnets, the detectors could be located far from the interaction point on a beamline tangent to the storage ring. The detection of the antihydrogen is accomplished by ionizing the atoms far from the interaction point. The positron is deflected by a magnetic spectrometer and detected, as are the back to back photons resulting from its annihilation. The antiproton travels a distance long enough for its momentum and time of flight to be measured accurately. A statistically significant sample of 101 antihydrogen atoms has been observed. A measurement of the cross section for {bar H}{sup 0} production is outlined within. The cross section corresponds to the process where a high momentum antiproton causes e{sup +} e{sup -} pair creation near a nucleus with the e{sup +} being captured by the antiproton. Antihydrogen is the first atom made exclusively of antimatter to be detected. The observation experiment's results are the first step towards an antihydrogen spectroscopy experiment which would measure the n = 2 Lamb shift and fine structure.

Blanford, Glenn DelFosse

1998-01-01T23:59:59.000Z

197

Highly-Sensitive and Efficient Infrared Absorption Spectroscopy  

E-Print Network (OSTI)

Greg Ward Paul Bell Sophy Palmer Jody Palmer Helen Hayward Dave Evans Sean Paling Ria Johnson Ian Taylor David Chow Ling Yan Hung James Keates Pawel Majewski Joel Weller Terrance Figy Gudrun Heinrich Cook Philip Rodrigues Laurence Carson Julian Sonner Raymond Davis Iain D Kendall Dave Pickup David

Lindsay, C. Michael

198

Potassium emission absorption system. Topical report 12  

DOE Green Energy (OSTI)

The Potassium Emission Absorption System is one of the advanced optical diagnostics developed at Mississippi State University to provide support for the demonstration of prototype-scale coal-fired combustion magnetohydrodynamic (MHD) electrical power generation. Intended for application in the upstream of an MHD flow, the system directly measures gas temperature and neutral potassium atom number density through spectroscopic emission absorption techniques. From these measurements the electron density can be inferred from a statistical equilibrium calculation and the electron conductivity in the MHD channel found by use of an electron mobility model. The instrument has been utilized for field test measurements on MHD facilities for almost a decade and has been proven to provide useful measurements as designed for MHD nozzle, channel, and diffuser test sections. The theory of the measurements, a system description, its capabilities, and field test measurement results are reported here. During the development and application of the instrument several technical issues arose which when addressed advanced the state of the art in emission absorption measurement. Studies of these issues are also reported here and include: two-wavelength measurements for particle-laden flows, potassium D-line far wing absorption coefficient, bias in emission absorption measurements arising from dirty windows and misalignments, non-coincident multiwavelength emission absorption sampling errors, and lineshape fitting for boundary layer flow profile information. Although developed for NLHD application, the instrument could be applied to any high temperature flow with a resonance line in the 300 to 800 nm range, for instance other types of flames, rocket plumes or low temperature plasmas.

Bauman, L.E.

1995-04-01T23:59:59.000Z

199

Dirac Charge Dynamcs in Graphene by Infrared Spectroscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Dirac Charge Dynamcs in Graphene by Infrared Spectroscopy Print Graphene-a single layer of carbon atoms arranged in a honeycomb lattice-has very high conductivity that can be tuned...

200

Absorption heat pump system  

DOE Patents (OSTI)

An improvement in an absorption heat pump cycle is obtained by adding adiabatic absorption and desorption steps to the absorber and desorber of the system. The adiabatic processes make it possible to obtain the highest temperature in the absorber before any heat is removed from it and the lowest temperature in the desorber before heat is added to it, allowing for efficient utilization of the thermodynamic availability of the heat supply stream. The improved system can operate with a larger difference between high and low working fluid concentrations, less circulation losses, and more efficient heat exchange than a conventional system.

Grossman, Gershon (Oak Ridge, TN); Perez-Blanco, Horacio (Knoxville, TN)

1984-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "atomic absorption spectroscopy" 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

Buffer-gas-induced absorption resonances in Rb vapor RID B-9041-2008  

E-Print Network (OSTI)

We observe transformation of the electromagnetically induced transparency (EIT) resonance into an absorption resonance in a Lambda interaction configuration in a cell filled with Rb-87 and a buffer gas. This transformation occurs as one-photon detuning of the coupling fields is varied from the atomic transition. No such absorption resonance is found in the absence of a buffer gas. The width of the absorption resonance is several times smaller than the width of the EIT resonance, and the changes of absorption near these resonances are about the same. Similar absorption resonances are detected in the Hanle configuration in a buffered cell.

Mikhailov, E. E.; Novikova, I.; Rostovtsev, Y. V.; Welch, George R.

2004-01-01T23:59:59.000Z

202

Kaonic Atom X?ray Spectra  

Science Conference Proceedings (OSTI)

In kaonic atoms energy displacement and broadening of states result from the strong interaction. The most simple kaonic atoms like kaonic hydrogen and deuterium open the possibility to measure this strong interaction induced shift and width by x?ray spectroscopy. In the SIDDHARTA experiment al LNF (Frascati) the DA?NE electron?positron collider delivers nearly mono?energetic negatively charged kaons from ? meson decay. This unique kaon source is used to form kaonic atoms. New high performance x?ray detectors (silicon drift detectors) arranged in an array allow x?ray spectroscopy with high energy resolution combined with timing capability. High precision x?ray measurements like SIDDHARTA at LNF will open the way to study the low energy regime of the strong force in the antikaon?nucleon interaction. The experiment and its current status is presented in this talk.

J. Marton; on behalf of the SIDDHARTA Collaboration

2009-01-01T23:59:59.000Z

203

Dynamical polarization in pionic atoms  

SciTech Connect

Dynamical nuclear polarization occurs in pionic atoms when a nuclear excitation of appropriate multipolarity is nearly degenerate with de-excitation of a pion atomic level. This phenomenon has been studied in several nuclei, one goal being to test the pion optical potential for pion atomic states normally ''hidden'' because of pion absorption. We find that, in addition to Coulomb mixing of the atomic and nuclear levels, strong interaction mixing and nuclear excitations above the lowest collective quadrupole mode are important for understanding the experimental results. All cases except /sup 110/Pd can then be understood. For /sup 110/Pd, additional nuclear structure information is needed to determine whether or not the conventional pion optical potential will suffice again. We discuss the sensitivity of dynamical polarization measurements to the parameters of the optical potential and to various aspects of nuclear structure. In particular, we find that pionic /sup 150/Sm provides a test of the interacting boson model and that the difference in neutron and proton radii predicted by Hartree-Fock calculations affects the mixing appreciably.

Dubach, J.F.; Moniz, E.J.; Nixon, G.D.

1979-08-01T23:59:59.000Z

204

In Situ X-Ray Absorption Spectroscopy Study of Hydrogen Absorption...  

NLE Websites -- All DOE Office Websites (Extended Search)

Buildings Cool Roofs and Heat Islands Demand Response Energy Efficiency Program and Market Trends High Technology and Industrial Buildings Lighting Systems Residential Buildings...

205

Novel gold cantilever for nano-Raman spectroscopy of graphene  

Science Conference Proceedings (OSTI)

This paper presents the simultaneous topographical and tip-enhanced Raman imaging of single layer and multilayer graphene flakes. The probe tips suitable for tapping mode atomic force microscopy (AFM) and tip-enhanced Raman spectroscopy have been fabricated ... Keywords: Atomic force microscopy, Graphene, Nano-Raman, Tip-enhanced

Valentinas Snitka; Raul D. Rodrigues; Vitas Lendraitis

2011-08-01T23:59:59.000Z

206

Isotope Enrichment Detection by Laser Ablation - Dual Tunable Diode Laser Absorption Spectrometry  

Science Conference Proceedings (OSTI)

The rapid global expansion of nuclear energy is motivating the expedited development of new safeguards technology to mitigate potential proliferation threats arising from monitoring gaps within the uranium enrichment process. Current onsite enrichment level monitoring methods are limited by poor sensitivity and accuracy performance. Offsite analysis has better performance, but this approach requires onsite hand sampling followed by time-consuming and costly post analysis. These limitations make it extremely difficult to implement comprehensive safeguards accounting measures that can effectively counter enrichment facility misuse. In addition, uranium enrichment by modern centrifugation leads to a significant proliferation threat, since the centrifuge cascades can quickly produce a significant quantity of highly enriched uranium (HEU). The Pacific Northwest National Laboratory is developing an engineered safeguards approach having continuous aerosol particulate collection and uranium isotope analysis to provide timely detection of HEU production in a low enriched uranium facility. This approach is based on laser vaporization of aerosol particulate samples, followed by wavelength tuned laser diode spectroscopy, to characterize the 235U/238U isotopic ratio by subtle differences in atomic absorption wavelengths arising from differences in each isotope’s nuclear mass, volume, and spin (hyperfine structure for 235U). Environmental sampling media is introduced into a small, reduced pressure chamber, where a focused pulsed laser vaporizes a 10 to 20-µm sample diameter. The ejected plasma forms a plume of atomic vapor. A plume for a sample containing uranium has atoms of the 235U and 238U isotopes present. Tunable diode lasers are directed through the plume to selectively excite each isotope and their presence is detected by monitoring absorbance signals on a shot-to-shot basis. Single-shot detection sensitivity approaching the femtogram range and abundance uncertainty less than 10% have been demonstrated with measurements on surrogate materials. In this paper we present measurement results on samples containing background materials (e.g., dust, minerals, soils) laced with micron-sized target particles having isotopic ratios ranging from 1 to 50%.

Anheier, Norman C.; Bushaw, Bruce A.

2009-07-01T23:59:59.000Z

207

The Quantum Absorption Refrigerator  

E-Print Network (OSTI)

A quantum absorption refrigerator driven by noise is studied with the purpose of determining the limitations of cooling to absolute zero. The model consists of a working medium coupled simultaneously to hot, cold and noise baths. Explicit expressions for the cooling power are obtained for Gaussian and Poisson white noise. The quantum model is consistent with the first and second laws of thermodynamics. The third law is quantified, the cooling power J_c vanishes as J_c proportional to T_c^{alpha}, when T_c approach 0, where alpha =d+1 for dissipation by emission and absorption of quanta described by a linear coupling to a thermal bosonic field, where d is the dimension of the bath.

Amikam Levy; Ronnie Kosloff

2011-09-04T23:59:59.000Z

208

Laser Probing of Neutron-Rich Nuclei in Light Atoms  

E-Print Network (OSTI)

The neutron-rich 6He and 8He isotopes exhibit an exotic nuclear structure that consists of a tightly bound 4He-like core with additional neutrons orbiting at a relatively large distance, forming a halo. Recent experimental efforts have succeeded in laser trapping and cooling these short-lived, rare helium atoms, and have measured the atomic isotope shifts along the 4He-6He-8He chain by performing laser spectroscopy on individual trapped atoms. Meanwhile, the few-electron atomic structure theory, including relativistic and QED corrections, has reached a comparable degree of accuracy in the calculation of the isotope shifts. In parallel efforts, also by measuring atomic isotope shifts, the nuclear charge radii of lithium and beryllium isotopes have been studied. The techniques employed were resonance ionization spectroscopy on neutral, thermal lithium atoms and collinear laser spectroscopy on beryllium ions. Combining advances in both atomic theory and laser spectroscopy, the charge radii of these light halo nuclei have now been determined for the first time independent of nuclear structure models. The results are compared with the values predicted by a number of nuclear structure calculations, and are used to guide our understanding of the nuclear forces in the extremely neutron-rich environment.

Z. -T. Lu; P. Mueller; G. W. F. Drake; W. Noertershaeuser; Steven C. Pieper; Z. -C. Yan

2013-07-10T23:59:59.000Z

209

X-ray and vibrational spectroscopy of manganese complexes relevant to the oxygen-evolving complex of photosynthesis  

SciTech Connect

Manganese model complexes, relevant to the oxygen-evolving complex (OEC) in photosynthesis, were studied with Mn K-edge X-ray absorption near-edge spectroscopy (XANES), Mn Kb X-ray emission spectroscopy (XES), and vibrational spectroscopy. A more detailed understanding was obtained of the influence of nuclearity, overall structure, oxidation state, and ligand environment of the Mn atoms on the spectra from these methods. This refined understanding is necessary for improving the interpretation of spectra of the OEC. Mn XANES and Kb XES were used to study a di-(mu)-oxo and a mono-(mu)-oxo di-nuclear Mn compound in the (III,III), (III,IV), and (IV,IV) oxidation states. XANES spectra show energy shifts of 0.8 - 2.2 eV for 1-electron oxidation-state changes and 0.4 - 1.8 eV for ligand-environment changes. The shifts observed for Mn XES spectra were approximately 0.21 eV for oxidation state-changes and only approximately 0.04 eV for ligand-environment changes. This indicates that Mn Kb XES i s more sensitive to the oxidation state and less sensitive to the ligand environment of the Mn atoms than XANES. These complimentary methods provide information about the oxidation state and the ligand environment of Mn atoms in model compounds and biological systems. A versatile spectroelectrochemical apparatus was designed to aid the interpretation of IR spectra of Mn compounds in different oxidation states. The design, based on an attenuated total reflection device, permits the study of a wide spectral range: 16,700 (600 nm) - 225

Visser, Hendrik

2001-05-16T23:59:59.000Z

210

Method of trivalent chromium concentration determination by atomic spectrometry  

DOE Patents (OSTI)

A method is disclosed for determining the concentration of trivalent chromium Cr(III) in a sample. The addition of perchloric acid has been found to increase the atomic chromium spectrometric signal due to Cr(III), while leaving the signal due to hexavalent chromium Cr(VI) unchanged. This enables determination of the Cr(III) concentration without pre-concentration or pre-separation from chromium of other valences. The Cr(III) concentration may be measured using atomic absorption spectrometry, atomic emission spectrometry or atomic fluorescence spectrometry.

Reheulishvili, Aleksandre N. (Tbilisi, 0183, GE); Tsibakhashvili, Neli Ya. (Tbilisi, 0101, GE)

2006-12-12T23:59:59.000Z

211

Alignment of the photoelectron spectroscopy beamline at NSRL  

E-Print Network (OSTI)

The photoelectron spectroscopy beamline at National Synchrotron Radiation Laboratory (NSRL) is equipped with a spherical grating monochromator with the included angle of 174 deg. Three gratings with line density of 200, 700 and 1200 lines/mm are used to cover the energy region from 60 eV to 1000 eV. After several years operation, the spectral resolution and flux throughput were deteriorated, realignment is necessary to improve the performance. First, the wavelength scanning mechanism, the optical components position and the exit slit guide direction are aligned according to the design value. Second, the gratings are checked by Atomic Force Microscopy (AFM). And then the gas absorption spectrum is measured to optimize the focusing condition of the monochromator. The spectral resolving power is recovered to the designed value of 1000@244eV. The flux at the end station for the 200 lines/mm grating is about 10^10 photons/sec/200mA, which is in accordance with the design. The photon flux for the 700 lines/mm grati...

Li, Chaoyang; Wen, Shen; Pan, Congyuan; An, Ning; Du, Xuewei; Zhu, Junfa; Wang, Qiuping

2013-01-01T23:59:59.000Z

212

Ultraviolet absorption hygrometer  

DOE Patents (OSTI)

An ultraviolet absorption hygrometer is provided including a source of pulsed ultraviolet radiation for providing radiation in a first wavelength region where water absorbs significantly and in a second proximate wavelength region where water absorbs weakly. Ultraviolet radiation in the first and second regions which has been transmitted through a sample path of atmosphere is detected. The intensity of the radiation transmitted in each of the first and second regions is compared and from this comparison the amount of water in the sample path is determined.

Gersh, Michael E. (Bedford, MA); Bien, Fritz (Concord, MA); Bernstein, Lawrence S. (Bedford, MA)

1986-01-01T23:59:59.000Z

213

Stability of Jahn-Teller distortion in LaMnO{sub 3} under pressure: An x-ray absorption study  

SciTech Connect

The local environment of manganese atoms in LaMnO{sub 3} under pressure up to 15.3 GPa has been studied by x-ray absorption spectroscopy. For pressures below 8 GPa, no change is detected within the MnO{sub 6} octahedra. Above this pressure a continuous reduction of the long Mn-O distance takes place, however, the octahedral distortion persists over the whole pressure range. At 15.3 GPa the average Jahn-Teller splitting of the distances is reduced by about one-third, indicating that a total removal of the local Jahn-Teller distortion would occur only for pressures around 30 GPa, where metallization is reported to take place. A hysteresis in the long distance reduction is observed down to ambient pressure, suggesting the coexistence of MnO{sub 6} distorted and undistorted units.

Ramos, Aline Y.; Tolentino, Helio C. N.; Souza-Neto, Narcizo M.; Itie, Jean-Paul; Morales, Liliana; Caneiro, Alberto [Institut Neel, UPR 2940-CNRS, 25 av. des Martyrs, Boite Postale 166, 38042 Grenoble, France and Laboratorio Nacional de Luz Sincrotron-LNLS, P.O. Box 6192, 13084-971, Campinas, Sao Paulo (Brazil); Laboratorio Nacional de Luz Sincrotron-LNLS, P.O. Box 6192, 13084-971, Campinas, Sao Paulo, Brazil and Departamento de Fisica dos Materiais e Mecanica, DFMT-IF-USP, Sao Paulo, SP (Brazil); Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, Boite Postale 48, 91192 Gif-sur-Yvette Cedex (France); Centro Atomico Bariloche and Instituto Balseiro, Comision Nacional de Energia Atomica and Universidad Nacional de Cuyo, 8400 S.C. de Bariloche (Argentina)

2007-02-01T23:59:59.000Z

214

X-ray absorption spectroscopic studies of the dinuclear iron center in methane monooxygenase and the sulfure and chlorine centers in photographic materials  

DOE Green Energy (OSTI)

The dinuclear iron center of the hydroxylase component of soluble methane monooxygenase (MMO) from Methylococcus capsulatus and Methylosinus trichosporiwn has been studied by X-ray absorption spectroscopy. Analysis of the Fe K-edge EXAFS revealed that the first shell coordination of the Fe(HI)Fe(IH) oxidized state of the hydroxylase from M. capsulatus consists of approximately 6 N and 0 atoms at an average distance of 2.04 {Angstrom}. The Fe-Fe distance was determined to be 3.4 {Angstrom}. No evidence for the presence of a short oxo bridge in the iron center of the oxidized hydroxylase was found, suggesting that the active site of MMO is significantly different from the active sites of the dinuclear iron proteins hemery and ribonucleotide reductase. In addition, the results of the first shell fits suggest that there are more oxygen than nitrogen donor ligands.

DeWitt, J.G.

1992-12-01T23:59:59.000Z

215

X-ray absorption spectroscopic studies of the dinuclear iron center in methane monooxygenase and the sulfure and chlorine centers in photographic materials  

DOE Green Energy (OSTI)

The dinuclear iron center of the hydroxylase component of soluble methane monooxygenase (MMO) from Methylococcus capsulatus and Methylosinus trichosporiwn has been studied by X-ray absorption spectroscopy. Analysis of the Fe K-edge EXAFS revealed that the first shell coordination of the Fe(HI)Fe(IH) oxidized state of the hydroxylase from M. capsulatus consists of approximately 6 N and 0 atoms at an average distance of 2.04 [Angstrom]. The Fe-Fe distance was determined to be 3.4 [Angstrom]. No evidence for the presence of a short oxo bridge in the iron center of the oxidized hydroxylase was found, suggesting that the active site of MMO is significantly different from the active sites of the dinuclear iron proteins hemery and ribonucleotide reductase. In addition, the results of the first shell fits suggest that there are more oxygen than nitrogen donor ligands.

DeWitt, J.G.

1992-12-01T23:59:59.000Z

216

Microsoft PowerPoint - SpectroscopyTechniques_XANES  

NLE Websites -- All DOE Office Websites (Extended Search)

Near Edge Spectroscopy (XANES) Near Edge Spectroscopy (XANES) XANES: XANES: * Element specific * Highly sensitive to bond angles, bond lengths, and the presence of adsorbates NEXAFS (Near Edge X-ray Absorption Fine Structure): * Synonymous with XANES but soft x-ray spectroscopy (< 1keV) * Fine structure within about 30 eV of the absorption edge EXAFS XANES / XRD C bi i S EXAFS-XANES / XRD Combination Spectroscopy * XAFS-XANES and XRD techniques give complementary information about the structure of materials. * XRD is effective in materials with medium- to long-range A typical XANES Spectrum XRD is effective in materials with medium to long range order while XAFS provides short-range information. *The simultaneous collection of the XRD and XAFS- XANES data in situ will allow

217

Synchrotron radiation x-ray absorption fine-structure and Raman studies on CdZnTe ternary alloys  

E-Print Network (OSTI)

The synchrotron radiation (SR) X-ray absorption fine-structure spectroscopy (XAFS) technology has been employed to obtained Zn K-edge absorption spectra for Cd1[subscript 1-x]Zn[subscript x]Te alloy with x = 0.03, 0.10, ...

Becla, Piotr

218

Atmospheric Precorrected Differential Absorption technique to retrieve columnar water vapor  

Science Conference Proceedings (OSTI)

Differential absorption techniques are suitable to retrieve the total column water vapor contents from imaging spectroscopy data. A technique called Atmospheric Precorrected Differential Absorption (APDA) is derived directly from simplified radiative transfer equations. It combines a partial atmospheric correction with a differential absorption technique. The atmospheric path radiance term is iteratively corrected during the retrieval of water vapor. This improves the results especially over low background albedos. The error of the method for various ground reflectance spectra is below 7% for most of the spectra. The channel combinations for two test cases are then defined, using a quantitative procedure, which is based on MODTRAN simulations and the image itself. An error analysis indicates that the influence of aerosols and channel calibration is minimal. The APDA technique is then applied to two AVIRIS images acquired in 1991 and 1995. The accuracy of the measured water vapor columns is within a range of {+-}5% compared to ground truth radiosonde data.

Schlaepfer, D.; Itten, K.I. [Univ. of Zuerich (Switzerland). Dept. of Geography] [Univ. of Zuerich (Switzerland). Dept. of Geography; Borel, C.C. [Los Alamos National Lab., NM (United States)] [Los Alamos National Lab., NM (United States); Keller, J. [Paul Scherrer Inst., Villigen (Switzerland)] [Paul Scherrer Inst., Villigen (Switzerland)

1998-09-01T23:59:59.000Z

219

Compressed sensing for multidimensional electronic spectroscopy experiments  

E-Print Network (OSTI)

Compressed sensing is a processing method that significantly reduces the number of measurements needed to accurately resolve signals in many fields of science and engineering. We develop a two-dimensional (2D) variant of compressed sensing for multidimensional electronic spectroscopy and apply it to experimental data. For the model system of atomic rubidium vapor, we find that compressed sensing provides significantly better resolution of 2D spectra than a conventional discrete Fourier transform from the same experimental data. We believe that by combining powerful resolution with ease of use, compressed sensing can be a powerful tool for the analysis and interpretation of ultrafast spectroscopy data.

J. N. Sanders; S. Mostame; S. K. Saikin; X. Andrade; J. R. Widom; A. H. Marcus; A. Aspuru-Guzik

2012-07-16T23:59:59.000Z

220

Ultrafast Spectroscopy of Warm Dense Matter  

NLE Websites -- All DOE Office Websites (Extended Search)

Ultrafast Spectroscopy of Warm Dense Matter Print Ultrafast Spectroscopy of Warm Dense Matter Print Being neither solid, liquid, gas, nor plasma, warm dense matter (WDM) occupies a no man's land in the map of material phases. Its temperature can range between that of planetary cores (tens of thousands K) to that of stellar cores (hundreds of thousands K). Not only is it prevalent throughout the universe, it is relevant to inertial confinement fusion (ICF) and material performance under extreme conditions. However, because of its extreme temperatures and pressures, WDM tends to be drastically transient and thus difficult to study in the laboratory. Now, researchers have set up ultrafast x-ray absorption spectroscopy at the ALS to measure the electronic structure of WDMs, demonstrating that fast-changing electron temperatures of matter under extreme conditions can be determined with picosecond resolution.

Note: This page contains sample records for the topic "atomic absorption spectroscopy" 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

Absorption Heat Pump Water Heater  

NLE Websites -- All DOE Office Websites (Extended Search)

Absorption Heat Pump Water Heater Absorption Heat Pump Water Heater Kyle Gluesenkamp Building Equipment Group, ETSD gluesenkampk@ornl.gov 865-241-2952 April 3, 2013 CRADA - GE Development of High Performance Residential Gas Water Heater Image courtesy John Wilkes 2 | Building Technologies Office eere.energy.gov Purpose & Objectives Problem Statement: Absorption technology could greatly boost water heater efficiency, but faces barriers of high first cost and working fluid challenges. Impact of Project: Energy factor of gas storage water

222

Absorption Heat Pump Water Heater  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Absorption Heat Pump Water Heater Absorption Heat Pump Water Heater Kyle Gluesenkamp Building Equipment Group, ETSD gluesenkampk@ornl.gov 865-241-2952 April 3, 2013 CRADA - GE Development of High Performance Residential Gas Water Heater Image courtesy John Wilkes 2 | Building Technologies Office eere.energy.gov Purpose & Objectives Problem Statement: Absorption technology could greatly boost water heater efficiency, but faces barriers of high first cost and working fluid challenges. Impact of Project: Energy factor of gas storage water

223

The Universe Adventure - Atoms  

NLE Websites -- All DOE Office Websites (Extended Search)

Matter and Atoms Matter and Atoms Richard Feynman "If, in some cataclysm, all of scientific knowledge were to be destroyed, and only one sentence passed on to the next generations of creatures, what statement would contain the most information in the fewest words? I believe it is that...all things are made of atoms." -Richard P. Feynman, winner of the 1965 Nobel Prize in Physics All is atoms Matter is made of atoms, and atoms are comprised of protons, neutrons, and electrons. Everything in the Universe is made of matter. Though matter exists in many different forms, each form is made out of the same basic constituents: small particles called atoms. Atoms themselves are made of smaller particles: protons, neutrons, and electrons. Protons and neutrons are composed of even smaller particles called quarks.

224

Reading Comprehension - Atomic History  

NLE Websites -- All DOE Office Websites (Extended Search)

Atomic History Atomic History A Greek philosopher named Democritus said that all atoms are small, hard particles. He thought that atoms were made of a single material formed into different shapes and sizes. The word " _________ element compound mixture atom " is derived from the Greek word "atomos" which means "not able to be divided." In 1803, John Dalton, a school teacher, proposed his atomic theory. Dalton's theory states that elements (substances composed of only one type of _________ molecules ions atom ) combine in certain proportions to form _________ compounds atoms mixtures elements . In 1897, a British scientist named J. J. Thomson experimented with a cathode-ray tube which had a positively charged plate. The plate attracted negatively charged particles that we now call _________ protons neutrons

225

Energy Basics: Absorption Heat Pumps  

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

Systems Air-Source Heat Pumps Ductless Mini-Split Heat Pumps Absorption Heat Pumps Geothermal Heat Pumps Supporting Equipment for Heating & Cooling Systems Water Heating...

226

Atomic and Molecular Physics  

Science Conference Proceedings (OSTI)

... DG, * SRD 105 Physic Laboratory's Elemental ... Nuclear Physics SRD 144 Atomic Weights & ... Physical Constants SRD 121 Fundamental Physical ...

2012-10-10T23:59:59.000Z

227

Atomizing nozzle and process  

DOE Patents (OSTI)

High pressure atomizing nozzle includes a high pressure gas manifold having a divergent expansion chamber between a gas inlet and arcuate manifold segment to minimize standing shock wave patterns in the manifold and thereby improve filling of the manifold with high pressure gas for improved melt atomization. The atomizing nozzle is especially useful in atomizing rare earth-transition metal alloys to form fine powder particles wherein a majority of the powder particles exhibit particle sizes having near-optimum magnetic properties.

Anderson, I.E.; Figliola, R.S.; Molnar, H.M.

1993-07-20T23:59:59.000Z

228

Calibrated Atomic Force Microscopy  

Science Conference Proceedings (OSTI)

... Vorburger, SL Tan, NG Orji, J. Fu, “Interlaboratory Comparison of Traceable Atomic Force Microscope Pitch Measurements,” SPIE Proceedings Vol. ...

2011-10-28T23:59:59.000Z

229

Structural determination of fluorite-type oxygen excess uranium oxides using EXAFS spectroscopy  

Science Conference Proceedings (OSTI)

Extended x-ray absorption fine structure (EXAFS) spectroscopy has been carried out at 77 K at the uranium L/sub III/ edge for UO/sub 2/, ..beta..-U/sub 3/O/sub 7/, and U/sub 4/O/sub 9/ with the aim of determining the structure of these highly defective (oxygen excess) uranium oxide phases, which are of industrial importance. Use has been made of a difference Fourier technique for U/sub 3/O/sub 7/, in which the EXAFS of a perfect lattice model is subtracted. U--O bond lengths calculated from the remaining EXAFS signal, assumed to result only from interstitial oxygens, have been used to determine the atomic coordinates of these interstitials. The analysis of EXAFS data in terms of coordination number has allowed an insight into the defect aggregate arrangement of oxygens in U/sub 3/O/sub 7/ and U/sub 4/O/sub 9/. Furthermore, EXAFS data indicate that the uranium sublattice is perturbed by the incorporation of additional oxygen atoms.

Jones, D.J.; Roziere, J.; Allen, G.C.; Tempest, P.A.

1986-06-01T23:59:59.000Z

230

NIST: Atomic Spectroscopy Group - Research Program for the ...  

Science Conference Proceedings (OSTI)

... these lines correctly and to assist in locating new energy levels. ... of interest to astrophysics, in particular for the study of chemically-peculiar stars. ...

2010-10-05T23:59:59.000Z

231

NIST: Atomic Spectroscopy Group - What is a Fourier ...  

Science Conference Proceedings (OSTI)

... Beamsplitters: Fused silica: 200 nm to 2.5 µm (50 000 cm -1 to 4000 cm -1 ). Calcium Fluoride: 1 µm to 10 µm (10 000 cm -1 to 1000 cm -1 ). ...

2010-10-05T23:59:59.000Z

232

2011 Elsevier/Spectrochimica Acta Atomic Spectroscopy Award  

NLE Websites -- All DOE Office Websites (Extended Search)

More Search Research & Development Batteries and Fuel Cells Li-Ion and Other Advanced Battery Technologies Buildings Energy Efficiency Applications Commercial Buildings Cool...

233

Auger electron spectroscopy  

SciTech Connect

A review of Auger electron spectroscopy is presented. Methods, resolution, sensitivity, and uses are discussed. 30 references, 10 figures. (GHT)

Somorjai, G.A.

1980-12-01T23:59:59.000Z

234

Atoms in Flight: The Remarkable Connections between Atomic and Hadronic Physics  

SciTech Connect

Atomic physics and hadron physics are both based on Yang Mills gauge theory; in fact, quantum electrodynamics can be regarded as the zero-color limit of quantum chromodynamics. I review a number of areas where the techniques of atomic physics provide important insight into the theory of hadrons in QCD. For example, the Dirac-Coulomb equation, which predicts the spectroscopy and structure of hydrogenic atoms, has an analog in hadron physics in the form of light-front relativistic equations of motion which give a remarkable first approximation to the spectroscopy, dynamics, and structure of light hadrons. The renormalization scale for the running coupling, which is unambiguously set in QED, leads to a method for setting the renormalization scale in QCD. The production of atoms in flight provides a method for computing the formation of hadrons at the amplitude level. Conversely, many techniques which have been developed for hadron physics, such as scaling laws, evolution equations, and light-front quantization have equal utility for atomic physics, especially in the relativistic domain. I also present a new perspective for understanding the contributions to the cosmological constant from QED and QCD.

Brodsky, Stanley J.; /SLAC

2012-02-16T23:59:59.000Z

235

Atomic Data for Mercury (Hg)  

Science Conference Proceedings (OSTI)

... Mercury (Hg) Homepage - Introduction Finding list Select element by name. Select element by atomic number. ... Atomic Data for Mercury (Hg). ...

236

Atomic Data for Plutonium (Pu)  

Science Conference Proceedings (OSTI)

... Plutonium (Pu) Homepage - Introduction Finding list Select element by name. Select element by atomic number. ... Atomic Data for Plutonium (Pu). ...

237

Atomic Data for Uranium (U )  

Science Conference Proceedings (OSTI)

... Uranium (U) Homepage - Introduction Finding list Select element by name. Select element by atomic number. ... Atomic Data for Uranium (U). ...

238

Atomic Data for Thorium (Th)  

Science Conference Proceedings (OSTI)

... Thorium (Th) Homepage - Introduction Finding list Select element by name. Select element by atomic number. ... Atomic Data for Thorium (Th). ...

239

Atomic Data for Hydrogen (H )  

Science Conference Proceedings (OSTI)

... Hydrogen (H) Homepage - Introduction Finding list Select element by name. Select element by atomic number. ... Atomic Data for Hydrogen (H). ...

240

Atomic Data for Tungsten (W )  

Science Conference Proceedings (OSTI)

... Tungsten (W) Homepage - Introduction Finding list Select element by name. Select element by atomic number. ... Atomic Data for Tungsten (W). ...

Note: This page contains sample records for the topic "atomic absorption spectroscopy" 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

ATOMS PEACE WAR Eisenhower  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

ATOMS ATOMS PEACE WAR Eisenhower and the Atomic Energy Commission Richard G. Hewlett and lack M. Roll With a Foreword by Richard S. Kirkendall and an Essay on Sources by Roger M. Anders University of California Press Berkeley Los Angeles London Published 1989 by the University of California Press Berkeley and Los Angeles, California University of California Press, Ltd. London, England Prepared by the Atomic Energy Commission; work made for hire. Library of Congress Cataloging-in-Publication Data Hewlett, Richard G. Atoms for peace and war, 1953-1961. (California studies in the history of science) Bibliography: p. Includes index. 1. Nuclear energy-United States-History. 2. U.S. Atomic Energy Commission-History. 3. Eisenhower, Dwight D. (Dwight David), 1890-1969.

242

Metal atom oxidation laser  

DOE Patents (OSTI)

A chemical laser which operates by formation of metal or carbon atoms and reaction of such atoms with a gaseous oxidizer in an optical resonant cavity is described. The lasing species are diatomic or polyatomic in nature and are readily produced by exchange or other abstraction reactions between the metal or carbon atoms and the oxidizer. The lasing molecules may be metal or carbon monohalides or monoxides. (auth)

Jensen, R.J.; Rice, W.W.; Beattie, W.H.

1975-10-28T23:59:59.000Z

243

Metal atom oxidation laser  

DOE Patents (OSTI)

A chemical laser which operates by formation of metal or carbon atoms and reaction of such atoms with a gaseous oxidizer in an optical resonant cavity is described. The lasing species are diatomic or polyatomic in nature and are readily produced by exchange or other abstraction reactions between the metal or carbon atoms and the oxidizer. The lasing molecules may be metal or carbon monohalides or monoxides.

Jensen, R.J.; Rice, W.W.; Beattie, W.H.

1975-10-28T23:59:59.000Z

244

NIST Atomic Spectra Database  

Science Conference Proceedings (OSTI)

... Ground states and ionization energies of atoms ... the US Department of Energy, by the ... SRDP), and by NIST's Systems Integration for Manufacturing ...

2013-09-12T23:59:59.000Z

245

Cold Atoms News  

Science Conference Proceedings (OSTI)

... the first time caused a gas of atoms ... mysterious data in ultracold gases of rubidium ... Material May Demonstrate Long-Sought 'Liquid' Magnetic State ...

2010-10-20T23:59:59.000Z

246

The Harnessed Atom  

Energy.gov (U.S. Department of Energy (DOE))

The Harnessed Atom is a new middle school science, technology, engineering, and math (STEM) curriculum extension that focuses on nuclear science and energy. It offers teachers accurate, unbiased,...

247

Atomic Collapse Observed  

NLE Websites -- All DOE Office Websites (Extended Search)

Collapse State Observed Aided by Simulations, Scientists Observe Atomic Collapse State Quantum Mechanics Prediction Confirmed in Graphene Using NERSC's Hopper April 26, 2013 |...

248

Energy Basics: Absorption Heat Pumps  

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

but by a heat source such as natural gas, propane, solar-heated water, or geothermal-heated water. Because natural gas is the most common heat source for absorption heat...

249

Compact Absorption Chiller - Energy Innovation Portal  

The Compact Absorption Chiller uses microchannel technologies in an absorption heat pump which produces cooling using heat as the primary energy source.

250

H{alpha} ABSORPTION IN TRANSITING EXOPLANET ATMOSPHERES  

SciTech Connect

Absorption of stellar H{alpha} by the upper atmosphere of the planet HD 189733b has recently been detected by Jensen et al. Motivated by this observation, we have developed a model for atomic hydrogen in the n = 2 state and compared the resulting H{alpha} line profile to the observations. The model atmosphere is in hydrostatic balance, as well as thermal and photoionization equilibrium. Collisional and radiative transitions are included in the determination of the n = 2 state level population. We find that H{alpha} absorption is dominated by an optical depth {tau} {approx} 1 shell, composed of hydrogen in the metastable 2s state that is located below the hydrogen ionization layer. The number density of the 2s state within the shell is found to vary slowly with radius, while that of the 1s state falls rapidly. Thus while the Ly{alpha} absorption, for a certain wavelength, occurs inside a relatively well defined impact parameter, the contribution to H{alpha} absorption is roughly uniform over the entire atomic hydrogen layer. The model can approximately reproduce the observed Ly{alpha} and H{alpha} integrated transit depths for HD 189733b by using an ionization rate enhanced over that expected for the star by an order of magnitude. For HD 209458b, we are unable to explain the asymmetric H{alpha} line profile observed by Jensen et al., as the model produces a symmetric line profile with transit depth comparable to that of HD 189733b. In an appendix, we study the effect of the stellar Ly{alpha} absorption on the net cooling rate.

Christie, Duncan; Arras, Phil; Li Zhiyun, E-mail: dac5zm@virginia.edu, E-mail: pla7y@virginia.edu, E-mail: zl4h@virginia.edu [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904-4325 (United States)

2013-08-01T23:59:59.000Z

251

General Method for Determination of the Surface Composition in Bimetallic Nanoparticle Catalysts from the L Edge X-ray Absorption Near-Edge Spectra  

SciTech Connect

Bimetallic PtPd on silica nano-particle catalysts have been synthesized and their average structure determined by Pt L3 and Pd K-edge extended X-ray absorption finestructure (EXAFS) spectroscopy. The bimetallic structure is confirmed from elemental line scans by STEM for the individual 1-2 nm sized particles. A general method is described to determine the surface composition in bimetallic nanoparticles even when both metals adsorb, for example, CO. By measuring the change in the L3 X-ray absorption near-edge structure (XANES) spectra with and without CO in bimetallic particles and comparing these changes to those in monometallic particles of known size the fraction of surface atoms can be determined. The turnover rates (TOR) and neopentane hydrogenolysis and isomerization selectivities based on the surface composition suggest that the catalytic and spectroscopic properties are different from those in monometallic nano-particle catalysts. At the same neo-pentane conversion, the isomerization selectivity is higher for the PtPd catalyst while the TOR is lower than that of both Pt and Pd. As with the catalytic performance, the infrared spectra of adsorbed CO are not a linear combination of the spectra on monometallic catalysts. Density functional theory calculations indicate that the Pt-CO adsorption enthalpy increases while the Pd-CO bond energy decreases. The ability to determine the surface composition allows for a better understanding of the spectroscopic and catalytic properties of bimetallic nanoparticle catalysts.

Wu, Tiapin; Childers, David; Gomez, Carolina; Karim, Ayman M.; Schweitzer, Neil; Kropf, Arthur; Wang, Hui; Bolin, Trudy B.; Hu, Yongfeng; Kovarik, Libor; Meyer, Randall; Miller, Jeffrey T.

2012-10-31T23:59:59.000Z

252

Spectroscopy, Kinetics, and Dynamics of Combustion Radicals  

SciTech Connect

Spectroscopy, kinetics and dynamics of jet cooled hydrocarbon transients relevant to the DOE combustion mission have been explored, exploiting i) high resolution IR lasers, ii) slit discharge sources for formation of jet cooled radicals, and iii) high sensitivity detection with direct laser absorption methods and near the quantum shot noise limit. What makes this combination powerful is that such transients can be made under high concentrations and pressures characteristic of actual combustion conditions, and yet with the resulting species rapidly cooled (T ?10-15K) in the slit supersonic expansion. Combined with the power of IR laser absorption methods, this provides novel access to spectral detection and study of many critical combustion species.

Nesbitt, David J. [Research/Professor

2013-08-06T23:59:59.000Z

253

Local atomic and electronic structure in LaMnO{sub 3} across the orbital ordering transition  

SciTech Connect

The local atomic disorder and electronic structure in the environment of manganese atoms in LaMnO{sub 3} has been studied by x-ray absorption spectroscopy over a temperature range (300-870 K) covering the orbital ordering transition ({approx}710 K). The Mn-O distance splitting into short and long bonds (1.95 and 2.15 A) is kept across the transition temperature, so that the MnO{sub 6} octahedra remain locally Jahn-Teller distorted. Discontinuities in the Mn local structure are identified in the extended x-ray fine structure spectra at this temperature, associated with a reduction of the disorder in the superexchange angle and to the removal of the anisotropy in the radial disorder within the coordination shell. Subtle changes in the electronic local structure also take place at the Mn site at the transition temperature. The near-edge spectra show a small drop of the Mn 4p hole count and a small enhancement in the pre-edge structures at the transition temperature. These features are associated with an increase of the covalence of the Mn-O bonds. Our results shed light on the local electronic and structural phenomena in a model of order-disorder transition, where the cooperative distortion is overcome by the thermal disorder.

Souza, Raquel A.; Souza-Neto, Narcizo M.; Ramos, Aline Y.; Tolentino, Helio C.N.; Granado, Eduardo [Laboratorio Nacional de Luz Sincrotron (LNLS), P.O. Box 6192, 13084-971, Campinas, Sao Paulo, Brazil and (Brazil); Instituto de Fisica Gleb Wataghin, IFGW-UNICAMP, Campinas, SP (Brazil); Laboratorio Nacional de Luz Sincrotron (LNLS), P.O. Box 6192, 13084-971, Campinas, Sao Paulo, Brazil and (Brazil); Departamento de Fisica dos Materiais e Mecanica, DFMT-IF-USP, Sao Paulo, SP (Brazil); Laboratorio Nacional de Luz Sincrotron (LNLS), P.O. Box 6192, 13084-971, Campinas, Sao Paulo, Brazil and (Brazil); Laboratoire de Mineralogie-Cristallographie de Paris, LMCP-UMR 7590-CNRS, Paris (France); Laboratorio Nacional de Luz Sincrotron (LNLS), P.O. Box 6192, 13084-971, Campinas, Sao Paulo (Brazil); Laboratorio Nacional de Luz Sincrotron (LNLS), P.O. Box 6192, 13084-971, Campinas, Sao Paulo, Brazil and (Brazil); Instituto de Fisica Gleb Wataghin, IFGW-UNICAMP, Campinas, SP (Brazil)

2004-12-01T23:59:59.000Z

254

Laser Induced Spectroscopy  

INL’s Laser Induced Spectroscopy technology detects and measures the composition of a material or the molecules in the material. It traces the ...

255

Alignment of the photoelectron spectroscopy beamline at NSRL  

E-Print Network (OSTI)

The photoelectron spectroscopy beamline at National Synchrotron Radiation Laboratory (NSRL) is equipped with a spherical grating monochromator with the included angle of 174 deg. Three gratings with line density of 200, 700 and 1200 lines/mm are used to cover the energy region from 60 eV to 1000 eV. After several years operation, the spectral resolution and flux throughput were deteriorated, realignment is necessary to improve the performance. First, the wavelength scanning mechanism, the optical components position and the exit slit guide direction are aligned according to the design value. Second, the gratings are checked by Atomic Force Microscopy (AFM). And then the gas absorption spectrum is measured to optimize the focusing condition of the monochromator. The spectral resolving power is recovered to the designed value of 1000@244eV. The flux at the end station for the 200 lines/mm grating is about 10^10 photons/sec/200mA, which is in accordance with the design. The photon flux for the 700 lines/mm grating is about 5 X 10^8 photons/sec/200mA, which is lower than expected. This poor flux throughput may be caused by carbon contamination on the optical components. The 1200 lines/mm grating has roughness much higher than expected so the diffraction efficiency is too low to detect any signal. A new grating would be ordered. After the alignment, the beamline has significant performance improvements in both the resolving power and the flux throughput for 200 and 700 lines/mm gratings and is provided to users.

Chaoyang Li; Hanbin Pan; Shen Wen; Congyuan Pan; Ning An; Xuewei Du; Junfa Zhu; Qiuping Wang

2013-03-04T23:59:59.000Z

256

Time-resolved multiple probe spectroscopy  

SciTech Connect

Time-resolved multiple probe spectroscopy combines optical, electronic, and data acquisition capabilities to enable measurement of picosecond to millisecond time-resolved spectra within a single experiment, using a single activation pulse. This technology enables a wide range of dynamic processes to be studied on a single laser and sample system. The technique includes a 1 kHz pump, 10 kHz probe flash photolysis-like mode of acquisition (pump-probe-probe-probe, etc.), increasing the amount of information from each experiment. We demonstrate the capability of the instrument by measuring the photolysis of tungsten hexacarbonyl (W(CO){sub 6}) monitored by IR absorption spectroscopy, following picosecond vibrational cooling of product formation through to slower bimolecular diffusion reactions on the microsecond time scale.

Greetham, G. M.; Sole, D.; Clark, I. P.; Parker, A. W.; Pollard, M. R.; Towrie, M. [Central Laser Facility, Science and Technology Facilities Council, Research Complex at Harwell, Rutherford Appleton Laboratory, Harwell, Oxfordshire, OX11 0QX (United Kingdom)

2012-10-15T23:59:59.000Z

257

Absorption of chromium and reduction of chromate by subterranean clover  

E-Print Network (OSTI)

In order to optimize phytoremediation techniques, it is important to first understand the plant physiological processes associated with enhanced absorption and translocation of the target metal in the plant. The emphasis in the current study is with chromium. The specific objectives were to: (1) determine the oxidation state of chromium in the plant using electron paramagnetic resonance (EPR) spectroscopy and x-ray absorption near edge spectroscopy (XANES), (2) investigate the probable mode of complication in plants grown in different Cr sources by EPR spectroscopy, (3) determine the distribution of Cr in plant tissues using synchrotron x-ray fluorescent (SXRF) microphone spectroscopy, and (4) determine the effect of root plasma membrane bound ferric reductive activity on Cr(VI) absorption. Subterranean clover (Trifolium brachycalvcinum Katzn. and Morley cv. Koala), utilized because of the relatively high tolerance, absorption, and translocation of CrO?²?, was grown hydroponically in a nutrient solution with Cr(III)Cl?, Cr(III)-oxalate, Cr(III)-citrate, Cr(III)-EDTA or K?Cr(VI)O? at a range of concentrations and exposure times. The uptake and translocation of Cr by the plant was dependent on the form and concentration of Cr supplied. Inorganic sources of Cr(III) precipitated in or on the roots of the plants as Cr(OH)?. In all cases, Cr predominantly existed in the plant as a Cr(III)-organic complex. There is some indication that Cr(III)-citrate and Cr(III)-oxalate were absorbed by the plant and, in the case of Cr(III)-citrate, translocated to the leaves. At high Cr(VI) treatment concentrations, Cr(VI), Cr(V), and Cr(III) were observed in the roots and Cr(V) and Cr(III) in the shoots. At low concentrations the plant could effectively reduce Cr(VI) to Cr(III), which is an important component of the detoxification mechanism. At low concentrations of Cr(VI), once in the vascular system, Cr was transported as a Cr(III)-organic complex to the leaf margins. At high concentrations of Cr(VI), SXRF microphone imaging revealed higher concentrations of Cr in the leaf veins than at the margin, indicating that Cr translocation to the leaf margin might be limited by Cr toxicity. Iron deficiency enhanced Cr uptake, particularly in the roots, indicating the possible involvement of ferric reductive in Cr uptake and reduction.

Howe, Julie Ann

1999-01-01T23:59:59.000Z

258

Materials' Deformation Dynamics at Atomic Scale In situ Atomic ...  

Science Conference Proceedings (OSTI)

Presentation Title, Materials' Deformation Dynamics at Atomic Scale In situ Atomic .... What Can We Learn from Measurements of Li-ion Battery Single Particles?

259

NETL: Pressure Swing Absorption Device  

NLE Websites -- All DOE Office Websites (Extended Search)

Pressure Swing Absorption Device and Process for Separating CO2 from Shifted Syngas and its Capture for Subsequent Storage Pressure Swing Absorption Device and Process for Separating CO2 from Shifted Syngas and its Capture for Subsequent Storage Project No.: DE-FE0001323 New Jersey Institute of Technology is developing an advanced pressure swing absorption-based (PSAB) device via laboratory-based experiments. The device will be used to accomplish a cyclic process to process low temperature post-shift-reactor synthesis gas resulting from the gasification process into purified hydrogen at high pressure for use by the combustion turbine of an integrated gasification combined cycle (IGCC) plant. The overall goal of the proposed work is to develop an advanced PSAB device and cyclic process for use in a coal-fired IGCC plant to produce purified hydrogen at high pressure and a highly purified CO2 stream suitable for use or sequestration.

260

CHARACTERIZATION OF THE LOCAL TITANIUM ENVIRONMENT IN DOPED SODIUM ALUMINUM HYDRIDE USING X-RAY ADSORPTION SPECTROSCOPY.  

DOE Green Energy (OSTI)

Ti K-edge x-ray absorption spectroscopy was used to explore the local titanium environment and valence in 2-4 mol% Ti-doped sodium alanate. An estimate of the oxidation state of the dopant, based upon known standards, revealed a zero-valent titanium atom. An analysis of the near-edge and extended fine structures indicates that the Ti does not enter substitutional or interstitial sites in the NaAlH{sub 4} lattice. Rather, the Ti is located on/near the surface and is coordinated by 10.2 {+-} 1 aluminum atoms with an interatomic distance of 2.82 {+-} 0.01 {angstrom}, similar to that of TiAl{sub 3}. The Fourier transformed EXAFS spectra reveals a lack of long-range order around the Ti dopant indicating that the Ti forms nano-clusters of TiAl{sub 3}. The similarity of the spectra in the hydrided and dehydrided samples suggests that the local Ti environment is nearly invariant during hydrogen cycling.

GRAETZ, J.; IGNATOV, A. YU; TYSON, T.A.; REILLY, J.J.; JOHNSON, J.

2004-11-30T23:59:59.000Z

Note: This page contains sample records for the topic "atomic absorption spectroscopy" 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

general_atomics.cdr  

NLE Websites -- All DOE Office Websites (Extended Search)

former former General Atomics Hot Cell Facility was constructed in 1959 and operated until 1991. The site encompassed approximately 7,400 square feet of laboratory and remote operations cells. Licensed operations at the facility included receipt, handling, and shipment of radioactive materials; remote handling, examination, and storage of previously irradiated nuclear fuel materials; pilot-scale tritium extraction operations; and development, fabrication, and inspection of uranium oxide-beryllium oxide fuel materials. General Atomics performed most of the work for the federal government. The General Atomics Hot Cell Facility was located in a 60-acre complex 13 miles northwest of downtown San Diego, 1 mile inland from the Pacific Ocean, and approximately 300 feet above sea level. The General Atomics site is in the center of Torrey Mesa Science Center, a 304-acre industrial

262

general_atomics.cdr  

Office of Legacy Management (LM)

from the U.S. Department of Energy (DOE). Discussions between DOE and General Atomics led to an agreed cost-sharing and no-fee arrangement for the decontamination and site...

263

Absorption-heat-pump system  

DOE Patents (OSTI)

An improvement in an absorption heat pump cycle is obtained by adding adiabatic absorption and desorption steps to the absorber and desorber of the system. The adiabatic processes make it possible to obtain the highest temperature in the absorber before any heat is removed from it and the lowest temperature in the desorber before heat is added to it, allowing for efficient utilization of the thermodynamic availability of the heat supply stream. The improved system can operate with a larger difference between high and low working fluid concentrations, less circulation losses, and more efficient heat exchange than a conventional system.

Grossman, G.; Perez-Blanco, H.

1983-06-16T23:59:59.000Z

264

Sharing the atom bomb  

Science Conference Proceedings (OSTI)

Shaken by the devastation of Hiroshima and Nagasaki and fearful that the American atomic monopoly would spark an arms race, Dean Acheson led a push in 1946 to place the bomb-indeed, all atomic energy-under international control. But as the memories of wartime collaboration faded, relations between the superpowers grew increasingly tense, and the confrontational atmosphere undid his proposal. Had Acheson succeeded, the Cold War might not have been. 2 figs.

Chace, J.

1996-01-01T23:59:59.000Z

265

Metal atomization spray nozzle  

DOE Patents (OSTI)

A spray nozzle for a magnetohydrodynamic atomization apparatus has a feed passage for molten metal and a pair of spray electrodes mounted in the feed passage. The electrodes, diverging surfaces which define a nozzle throat and diverge at an acute angle from the throat. Current passes through molten metal when fed through the throat which creates the Lorentz force necessary to provide atomization of the molten metal.

Huxford, Theodore J. (Harriman, TN)

1993-01-01T23:59:59.000Z

266

Metal atomization spray nozzle  

DOE Patents (OSTI)

A spray nozzle for a magnetohydrodynamic atomization apparatus has a feed passage for molten metal and a pair of spray electrodes mounted in the feed passage. The electrodes, diverging surfaces which define a nozzle throat and diverge at an acute angle from the throat. Current passes through molten metal when fed through the throat which creates the Lorentz force necessary to provide atomization of the molten metal. 6 figures.

Huxford, T.J.

1993-11-16T23:59:59.000Z

267

Effects of atomic radiation  

SciTech Connect

This book focuses on the lifelong effects of atomic radiation exposure in language understandable by the concerned layperson or the specialist in another field. The base of knowledge used is the work of the Atomic Bomb Casualty Commission and its successor since 1975 the Radiation Effects Research Foundation. Within the range of Chronic effects on human health the book provides a thorough review, although effects of nonionizing radiation, effects on structures, effects on other living species, and acute effects are not discussed.

Schull, W.J.

1995-12-31T23:59:59.000Z

268

Atomizing nozzle and method  

DOE Patents (OSTI)

A high pressure close-coupled gas atomizing nozzle includes multiple discrete gas jet discharge orifices having aerodynamically designed convergent-divergent geometry with an first converging section communicated to a gas supply manifold and to a diverging section by a constricted throat section to increase atomizing gas velocity. The gas jet orifices are oriented at gas jet apex angle selected relative to the melt supply tip apex angle to establish a melt aspiration condition at the melt supply tip.

Ting, Jason (Ames, IA); Anderson, Iver E. (Ames, IA); Terpstra, Robert L. (Ames, IA)

2000-03-16T23:59:59.000Z

269

Atomic Data for Americium (Am)  

Science Conference Proceedings (OSTI)

... Atomic Number = 95. Atomic Weight = (243). Reference E95. Isotope, Mass, Abundance, Spin, Mag Moment, 241 Am, 241.056823, 0, 5/2, +1.61. ...

270

Questions and Answers - How do atoms form?  

NLE Websites -- All DOE Office Websites (Extended Search)

(Biggest and smallest atom?) Questions and Answers Main Index Next Question (Does gravity affect atoms?) Does gravity affect atoms? How do atoms form? The current view is that...

271

Questions and Answers - Can you crush atoms?  

NLE Websites -- All DOE Office Websites (Extended Search)

Does gravity affect atoms? Previous Question (Does gravity affect atoms?) Questions and Answers Main Index Next Question (Parts and weights of atoms?) Parts and weights of atoms?...

272

Ab-initio calculations of the hydrogen-uranium system. Part I: Surface phenomena, absorption, transport and trapping  

DOE Green Energy (OSTI)

Density functional theory was applied to the initial steps of uranium hydriding: surface phenomena, absorption, bulk transport and trapping. H adsorbs exothermically to the (0 0 1) surface, yet H absorption into the bulk is endothermic, with off-center octahedral absorption having the lowest absorption energy of 0.39 eV, relative to molecular H{sub 2}. H absorption in interstitial sites causes a local softening of the bulk modulus. Diffusion of H in unstrained {alpha}-U has a barrier of 0.6 eV. The energy of H absorption adjacent to the chemical impurities C, S, Si was lowered by an amount proportional to the size of the impurity atom, and the resulting lattice strain Si > S > C. Thus, impurities may promote hydriding by providing surfaces or prestrained zones for H uptake.

Taylor, Christopher D [Los Alamos National Laboratory; Lillard, R Scott [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

273

Absorption Heat Pump Basics | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Absorption Heat Pump Basics Absorption Heat Pump Basics Absorption Heat Pump Basics August 19, 2013 - 11:11am Addthis Absorption heat pumps are essentially air-source heat pumps driven not by electricity, but by a heat source such as natural gas, propane, solar-heated water, or geothermal-heated water. Because natural gas is the most common heat source for absorption heat pumps, they are also referred to as gas-fired heat pumps. There are also absorption coolers available that work on the same principal, but are not reversible and cannot serve as a heat source. These are also called gas-fired coolers. How Absorption Heat Pumps Work Residential absorption heat pumps use an ammonia-water absorption cycle to provide heating and cooling. As in a standard heat pump, the refrigerant (in this case, ammonia) is condensed in one coil to release its heat; its

274

Absorption Heat Pumps | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Absorption Heat Pumps Absorption Heat Pumps Absorption Heat Pumps June 24, 2012 - 2:11pm Addthis Absorption heat pumps are essentially air-source heat pumps driven not by electricity, but by a heat source such as natural gas, propane, solar-heated water, or geothermal-heated water. Because natural gas is the most common heat source for absorption heat pumps, they are also referred to as gas-fired heat pumps. There are also absorption (or gas-fired) coolers available that work on the same principle. Unlike some absorption heat pumps, however, these are not reversible and cannot serve as a heat source. Residential absorption heat pumps use an ammonia-water absorption cycle to provide heating and cooling. As in a standard heat pump, the refrigerant (in this case, ammonia) is condensed in one coil to release its heat; its

275

Absorption Heat Pumps | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Absorption Heat Pumps Absorption Heat Pumps Absorption Heat Pumps June 24, 2012 - 2:11pm Addthis Absorption heat pumps are essentially air-source heat pumps driven not by electricity, but by a heat source such as natural gas, propane, solar-heated water, or geothermal-heated water. Because natural gas is the most common heat source for absorption heat pumps, they are also referred to as gas-fired heat pumps. There are also absorption (or gas-fired) coolers available that work on the same principle. Unlike some absorption heat pumps, however, these are not reversible and cannot serve as a heat source. Residential absorption heat pumps use an ammonia-water absorption cycle to provide heating and cooling. As in a standard heat pump, the refrigerant (in this case, ammonia) is condensed in one coil to release its heat; its

276

Peaceful Uses of the Atom and Atoms for Peace  

Office of Scientific and Technical Information (OSTI)

Peaceful Uses of the Atom Peaceful Uses of the Atom Fermi and Atoms for Peace · Understanding the Atom · Seaborg · Teller Atoms for Peace Atoms for Peace + 50 - Conference, October 22, 2003 Celebrating the 50th anniversary of President Eisenhower's "Atoms for Peace" speech to the UN General Assembly Atoms for Peace (video 12:00 Minutes) Atoms for Peace Address given by Dwight D. Eisenhower before the General Assembly of the United Nations, New York City, December 8, 1953 Documents: Atomic Power in Space: A History A history of the Space Isotope Power Program of the United States from the mid-1950s through 1982; interplanetary space exploration successes and achievements have been made possible by this technology. Establishing Site X: Letter, Arthur H. Compton to Enrico Fermi, September 14, 1942

277

Lesson 3- Atoms and Isotopes  

Energy.gov (U.S. Department of Energy (DOE))

You’ve probably heard people refer to nuclear energy as “atomic energy.” Why? Nuclear energy is the energy that is stored in the bonds of atoms, inside the nucleus. Nuclear power plants are designed to capture this energy as heat and convert it to electricity. This lesson looks closely at what atoms are and how atoms store energy.

278

general_atomics.cdr  

Office of Legacy Management (LM)

former General former General Atomics Hot Cell Facility was constructed in 1959 and operated until 1991. The site encompassed approximately 7,400 square feet of laboratory and remote operations cells. Licensed operations at the facility included receipt, handling, and shipment of radioactive materials; remote handling, examination, and storage of previously irradiated nuclear fuel materials; pilot-scale tritium extraction operations; and development, fabrication, and inspection of uranium oxide-beryllium oxide fuel materials. General Atomics performed most of the work for the federal government. The General Atomics Hot Cell Facility was located in a 60-acre complex 13 miles northwest of downtown San Diego, 1 mile inland from the Pacific Ocean, and approximately 300 feet above sea level.

279

The use of Surface Enhanced Raman Spectroscopy (SERS) for biomedical applications  

E-Print Network (OSTI)

Recent advances in nanotechnology and the biotechnology revolution have created an immense opportunity for the use of noble metal nanoparticles as Surface Enhanced Raman Spectroscopy (SERS) substrates for biological sensing and diagnostics. This is because SERS enhances the intensity of the Raman scattered signal from an analyte by orders of 106 or more. This dissertation deals with the different aspects involved in the application of SERS for biosensing. It discusses initial studies performed using traditional chemically reduced silver colloidal nanoparticles for the SERS detection of a myriad of proteins and nucleic acids. It examines ways to circumvent the inherent aggregation problems associated with colloidal nanoparticles that frequently lead to poor data reproducibility. The different methods examined to create robust SERS substrates include the creation of thermally evaporated silver island films on microscope glass slides, using the technique of Nanosphere Lithography (NSL) to create hexagonally close packed periodic particle arrays of silver nanoparticles on glass substrates as well as the use of optically tunable gold nanoshell films on glass substrates. The three different types of SERS surfaces are characterized using UV-Vis absorption spectroscopy, Electron Microscopy (EM), Atomic Force Microscopy (AFM) as well as SERS using the model Raman active molecule trans-1,2-bis(4-pyridyl)ethylene (BPE). Also discussed is ongoing work in the initial stages of the development of a SERS based biosensor using gold nanoshell films for the direct detection of b-amyloid, the causative agent for Alzheimer's disease. Lastly, the use of gold nanoshells as SERS substrates for the intracellular detection of various biomolecules within mouse fibroblast cells in cell culture is discussed. The dissertation puts into perspective how this study can represent the first steps in the development of a robust gold nanoshell based SERS biosensor that can improve the ability to monitor biological processes in real time, thus providing new avenues for designing systems for the early diagnosis of diseases.

Chowdhury, Mustafa Habib

2005-12-01T23:59:59.000Z

280

Animation of JILA Frequency Comb Spectroscopy Technique  

Science Conference Proceedings (OSTI)

Animation of JILA Frequency Comb Spectroscopy Technique. The new JILA "frequency comb spectroscopy" technique ...

2012-08-17T23:59:59.000Z

Note: This page contains sample records for the topic "atomic absorption spectroscopy" 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

Photodetector with enhanced light absorption  

DOE Patents (OSTI)

A photodetector including a light transmissive electrically conducting layer having a textured surface with a semiconductor body thereon. This layer traps incident light thereby enhancing the absorption of light by the semiconductor body. A photodetector comprising a textured light transmissive electrically conducting layer of SnO.sub.2 and a body of hydrogenated amorphous silicon has a conversion efficiency about fifty percent greater than that of comparative cells. The invention also includes a method of fabricating the photodetector of the invention.

Kane, James (Lawrenceville, NJ)

1985-01-01T23:59:59.000Z

282

Purge needs in absorption chillers  

Science Conference Proceedings (OSTI)

Absorption chillers are regaining a significant share of large tonnage chiller sales, such as they had 20 years ago. Gas-fired chillers are now available that have a base energy (ultimate fuel usage) consumption rate per ton comparable to that in electric units. Effective purging in an absorption chiller is an absolute necessity to achieve the low chilled water temperature needed for dehumidification and to fully benefit from the energy savings offered by double-effect cycles. Although the purge system is usually not shown on the typical cycle schematic, its proper functioning is a key requirement for satisfactory machine operation. This article discusses the effect of noncondensible (N/C) gases on the absorption cooling process and the basics of purge systems. In addition, the article discusses the rationale for the important design step of selecting the location of the N/C probe, and discusses purge systems applicable to the direct-fired, double-effect machines now entering the marketplace.

Murray, J.G. (Battelle, Columbus, OH (United States))

1993-10-01T23:59:59.000Z

283

EMSL: Capabilities: Spectroscopy and Diffraction  

NLE Websites -- All DOE Office Websites (Extended Search)

Spectroscopy and Diffraction Spectroscopy and Diffraction Additional Information Meet the Spectroscopy and Diffraction Experts Related EMSL User Projects Spectroscopy and Diffraction Tools are Applied to all Science Themes Tutorial: XPS Tools for Surface Analysis Spectroscopy and Diffraction brochure EMSL's suite of spectroscopy and diffraction instruments allows users to study solid-, liquid-, and gas-phase sample structure and composition with remarkable resolution. Ideal for integrated studies, spectrometers and diffractometers are easily coupled with EMSL's computational and modeling capabilities, allowing users to apply a multifaceted research approach for experimental data interpretation and gain fundamental understanding of scientific problems. At EMSL, spectroscopy and diffraction instruments are

284

JILA Researchers Discover Atomic Clock Can Simulate ...  

Science Conference Proceedings (OSTI)

... Artist's conception of interactions among atoms in JILA's strontium atomic clock during a quantum simulation experiment. ...

2013-08-20T23:59:59.000Z

285

Localized light absorption by nanoscale semiconducting tips ...  

Science Conference Proceedings (OSTI)

Page 1. Localized light absorption ... constructive interference between transmitted light and internal reflections at resonant radii Page 14. ...

2013-04-03T23:59:59.000Z

286

Quantization of the Atom plus Attempting to Answer Heilbron & Kuhn  

E-Print Network (OSTI)

The idea of atoms is old but X-rays provided the first probe into the physical atom. Photographs of X-ray scattering from crystals -Laue spots- were the first visual proof for the physical existence of atoms arranged in a perfect geometric pattern. Thereby conclusively established the stability and physical reality of atoms. The Braggs developed Laue technique to study atoms. Moseley applied (Bragg) X-ray spectroscopy to determine the nuclear charge number of Rutherford atom. We argue that Bohr also at Manchester and contemporary of Moseley likely was inspired by Laue discovery to get busy with the mechanics of the nuclear atom. Roentgens discovery was awarded the first Nobel prize ever in 1901, Laue was honored in 1914, the Braggs in 1915, making Lawrence Bragg then at 25 the youngest ever. Eleven of the cited authors (Bohr himself included) in the trilogy (but not Nicholson the most cited), were later recognized by ten Noble prize awards, seven Laureates in physics and four in chemistry. The ensuing synergy...

Jeong, Yeuncheol; Datta, Timir

2013-01-01T23:59:59.000Z

287

Lyman-alpha wing absorption in cool white dwarf stars  

E-Print Network (OSTI)

Kowalski & Saumon (2006) identified the missing absorption mechanism in the observed spectra of cool white dwarf stars as the Ly-alpha red wing formed by the collisions between atomic and molecular hydrogen and successfully explained entire spectra of many cool DA-type white dwarfs. Owing to the important astrophysical implications of this issue, we present here an independent assessment of the process. For this purpose, we compute free-free quasi-molecular absorption in Lyman-alpha due to collisions with H and H2 within the one-perturber, quasi-static approximation. Line cross-sections are obtained using theoretical molecular potentials to describe the interaction between the radiating atom and the perturber. The variation of the electric-dipole transition moment with the interparticle distance is also considered. Six and two allowed electric dipole transitions due to H-H and H-H2 collisions, respectively, are taken into account. The new theoretical Lyman-alpha line profiles are then incorporated in our ...

Rohrmann, R D; Kepler, S O

2010-01-01T23:59:59.000Z

288

Technique Subgroupings Spectroscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

and NSLS-II beamlines according to DOE Technique Scheme and NSLS-II beamlines according to DOE Technique Scheme Technique Subgroupings Spectroscopy 01 - Low Energy Spectroscopy Infrared Photoemission U12IR, U4IR / MET* U5UA, U13 / ESM 02 - Soft X-Ray Spectroscopy Soft X-ray Spectroscopy Tender XAS U4B, U7A, X24A / SST, SSS* X15B, X19A / TES* 03 - Hard X-ray Spectroscopy EXAFS X3A, X3B, X11A, X11B, X18A, X18B, X23A2 / ISS, BMM, QAS*, XAS* 04 - Optics/Calibration/Metrology U3C,X8A/ OFT,MID Scattering 05 X-ray Diffraction X-Ray Powder Diffraction Extreme Conditions Energy Dispersive Micro-Beam Diffraction X7B,X10B,X14A,X16C,X17A / XPD,IXD* X17B2,X17B3,X17C / XPD, TEC*, 4DE* X17B1, X17B2 / NA X13B / MXD* 06 MX, footprinting Protein Crystallography X-ray footprinting X4A, X4C, X6A, X12B, X12C, X25, X29 / FMX, AMX, NYX;

289

Double pulse laser induced breakdown spectroscopy; experimental study of  

NLE Websites -- All DOE Office Websites (Extended Search)

Double pulse laser induced breakdown spectroscopy; experimental study of Double pulse laser induced breakdown spectroscopy; experimental study of lead emission intensity dependence on the wavelengths and sample matrix Title Double pulse laser induced breakdown spectroscopy; experimental study of lead emission intensity dependence on the wavelengths and sample matrix Publication Type Journal Article Year of Publication 2009 Authors Piscitelli, Vincent, Mauro A. Martinez, Alberto J. Fernandez, Jhanis J. Gonzalez, Xianglei Mao, and Richard E. Russo Journal Spectrochimica Acta Part B Volume 64 Issue 2 Pagination 147-154 Date Published 02/2009 Keywords Double pulse LIBS, laser induced breakdown spectroscopy, lead Abstract Lead (Pb) emission intensity (atomic line 405.78 nm) dependence on the sample matrix (metal alloy) was studied by means of collinear double pulse (DP)-laser induced breakdown spectroscopy (LIBS). The measurement of the emission intensity produced by three different wavelength combinations (i.e. I:532 nm-II:1064 nm, I:532 nm-II:532 nm, and I:532 nm-II:355 nm) from three series of standard reference materials showed that the lead atomic line 405.78 nm emission intensity was dependent on the sample matrix for all the combination of wavelengths, however reduced dependency was found for the wavelength combination I:532 nm-II:355 nm.

290

Calibration of X-ray absorption in our Galaxy  

E-Print Network (OSTI)

Prediction of the soft X-ray absorption along lines of sight through our Galaxy is crucial for understanding the spectra of extragalactic sources, but requires a good estimate of the foreground column density of photoelectric absorbing species. Assuming uniform elemental abundances this reduces to having a good estimate of the total hydrogen column density, N(Htot)=N(HI)+2N(H2). The atomic component, N(HI), is reliably provided using the mapped 21 cm radio emission but estimating the molecular hydrogen column density, N(H2), expected for any particular direction, is difficult. The X-ray afterglows of GRBs are ideal sources to probe X-ray absorption in our Galaxy because they are extragalactic, numerous, bright, have simple spectra and occur randomly across the entire sky. We describe an empirical method, utilizing 493 afterglows detected by the Swift XRT, to determine N(Htot) through the Milky Way which provides an improved estimate of the X-ray absorption in our Galaxy and thereby leads to more reliable meas...

Willingale, R; Beardmore, A P; Tanvir, N R; O'Brien, P T

2013-01-01T23:59:59.000Z

291

MODELING THE OXYGEN K ABSORPTION IN THE INTERSTELLAR MEDIUM: AN XMM-NEWTON VIEW OF Sco X-1  

Science Conference Proceedings (OSTI)

We investigate the X-ray absorption structure of oxygen in the interstellar medium by analyzing XMM - Newton observations of the low-mass X-ray binary Sco X-1. Simple models based on the O I atomic photoabsorption cross section from different sources are used to fit the data and evaluate the impact of the atomic data on the interpretation of the observations. We show that relatively small differences in the atomic calculations can yield spurious results, and that the most complete and accurate set of atomic cross sections successfully reproduce the observed data in the 21.0-24.5 A wavelength region of the spectrum. Our fits indicate that the absorption is mainly due to neutral gas with an ionization parameter of {xi} = 10{sup -4} erg cm s{sup -1} and an oxygen column density of N{sub O} {approx} (8-10) x 10{sup 17} cm{sup -2}. The models are able to reproduce both the K edge and the K{alpha} absorption line from O I which are the two main features in this region. We find no conclusive evidence for absorption by anything other than atomic oxygen.

GarcIa, J.; Bautista, M. A. [Department of Physics, Western Michigan University, Kalamazoo, MI 49008 (United States); RamIrez, J. M. [Astrophysikalisches Institut Potsdam, An der Sternwarte 16 D-14482 Potsdam (Germany); Kallman, T. R.; Witthoeft, M. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Mendoza, C. [Centro de Fisica, IVIC, Caracas 1020 (Venezuela, Bolivarian Republic of); Palmeri, P.; Quinet, P., E-mail: javier.garcia@wmich.edu, E-mail: manuel.bautista@wmich.edu, E-mail: timothy.r.kallman@nasa.gov, E-mail: michael.c.witthoeft@nasa.gov, E-mail: jramirez@aip.de, E-mail: claudio@ivic.gob.v, E-mail: palmeri@umh.ac.be, E-mail: quinet@umh.ac.be [Astrophysique et Spectroscopie, Universite de Mons-UMONS, B-7000 Mons (Belgium)

2011-04-10T23:59:59.000Z

292

Advanced regenerative absorption refrigeration cycles  

DOE Patents (OSTI)

Multi-effect regenerative absorption cycles which provide a high coefficient of performance (COP) at relatively high input temperatures. An absorber-coupled double-effect regenerative cycle (ADR cycle) (10) is provided having a single-effect absorption cycle (SEA cycle) (11) as a topping subcycle and a single-effect regenerative absorption cycle (1R cycle) (12) as a bottoming subcycle. The SEA cycle (11) includes a boiler (13), a condenser (21), an expansion device (28), an evaporator (31), and an absorber (40), all operatively connected together. The 1R cycle (12) includes a multistage boiler (48), a multi-stage resorber (51), a multisection regenerator (49) and also uses the condenser (21), expansion device (28) and evaporator (31) of the SEA topping subcycle (11), all operatively connected together. External heat is applied to the SEA boiler (13) for operation up to about 500 degrees F., with most of the high pressure vapor going to the condenser (21) and evaporator (31) being generated by the regenerator (49). The substantially adiabatic and isothermal functioning of the SER subcycle (12) provides a high COP. For higher input temperatures of up to 700 degrees F., another SEA cycle (111) is used as a topping subcycle, with the absorber (140) of the topping subcycle being heat coupled to the boiler (13) of an ADR cycle (10). The 1R cycle (12) itself is an improvement in that all resorber stages (50b-f) have a portion of their output pumped to boiling conduits (71a-f) through the regenerator (49), which conduits are connected to and at the same pressure as the highest pressure stage (48a) of the 1R multistage boiler (48).

Dao, Kim (14 Nace Ave., Piedmont, CA 94611)

1990-01-01T23:59:59.000Z

293

Save by absorption heat pumping  

SciTech Connect

The author compares absorption heat pumping (AHP) to mechanical vapor compressor (MVC) heat pumping. The moving part of the AHP is a pump easy to maintain and inexpensive to spare. The mechanical component of the MVC is a vapor compressor which requires more maintenance and is cost-prohibitive to spare. Also, in the MVC system, a purified product stream is heat pumped in an open compressor, thus risking product contamination. In the AHP system, the cold and hot utilities are heat pumped. Therefore, product integrity with an AHP system is well protected as in a conventional fractionation column.

Davidson, W.F.; Campagne, W.V.L.

1987-12-01T23:59:59.000Z

294

Atomic Devices and Instrumentation Group  

Science Conference Proceedings (OSTI)

... 2001 and 2005, demonstrated an atomic clock physics package with ... magnetometers for magnetic anomaly detection, nuclear magnetic resonance ...

2013-08-09T23:59:59.000Z

295

Atom-Based Dimensional Metrology  

Science Conference Proceedings (OSTI)

... Awarded a five year, three phase DARPA contract to conduct collaborative research in atomically precise positioning, patterning and metrology ...

2013-04-19T23:59:59.000Z

296

Isotope Enrichment Detection by Laser Ablation - Laser Absorption Spectrometry: Automated Environmental Sampling and Laser-Based Analysis for HEU Detection  

SciTech Connect

The global expansion of nuclear power, and consequently the uranium enrichment industry, requires the development of new safeguards technology to mitigate proliferation risks. Current enrichment monitoring instruments exist that provide only yes/no detection of highly enriched uranium (HEU) production. More accurate accountancy measurements are typically restricted to gamma-ray and weight measurements taken in cylinder storage yards. Analysis of environmental and cylinder content samples have much higher effectiveness, but this approach requires onsite sampling, shipping, and time-consuming laboratory analysis and reporting. Given that large modern gaseous centrifuge enrichment plants (GCEPs) can quickly produce a significant quantity (SQ ) of HEU, these limitations in verification suggest the need for more timely detection of potential facility misuse. The Pacific Northwest National Laboratory (PNNL) is developing an unattended safeguards instrument concept, combining continuous aerosol particulate collection with uranium isotope assay, to provide timely analysis of enrichment levels within low enriched uranium facilities. This approach is based on laser vaporization of aerosol particulate samples, followed by wavelength tuned laser diode spectroscopy to characterize the uranium isotopic ratio through subtle differences in atomic absorption wavelengths. Environmental sampling (ES) media from an integrated aerosol collector is introduced into a small, reduced pressure chamber, where a focused pulsed laser vaporizes material from a 10 to 20-µm diameter spot of the surface of the sampling media. The plume of ejected material begins as high-temperature plasma that yields ions and atoms, as well as molecules and molecular ions. We concentrate on the plume of atomic vapor that remains after the plasma has expanded and then cooled by the surrounding cover gas. Tunable diode lasers are directed through this plume and each isotope is detected by monitoring absorbance signals on a shot-to-shot basis. The media is translated by a micron resolution scanning system, allowing the isotope analysis to cover the entire sample surface. We also report, to the best of our knowledge, the first demonstration of laser-based isotopic measurements on individual micron-sized particles that are minor target components in a much larger heterogeneous mix of ‘background’ particles. This composition is consistent with swipe and environmental aerosol samples typically collected for safeguards ES purposes. Single-shot detection sensitivity approaching the femtogram range and relative isotope abundance uncertainty better than 10% has been demonstrated using gadolinium isotopes as surrogate materials.

Anheier, Norman C.; Bushaw, Bruce A.

2010-01-01T23:59:59.000Z

297

New developments in IR surface vibrational spectroscopy  

DOE Green Energy (OSTI)

Low frequency dynamics at surfaces, particularly in the region of the adsorbate-substrate vibrational modes is of fundamental importance in areas as varied as sliding friction, catalysis, corrosion and epitaxial growth. This paper reviews the new developments in low frequency Infrared Reflection Absorption Spectroscopy using synchrotron radiation as the source. Absolute changes induced in the far infrared for several adsorbate systems on Cu, including CO and H, are dominated by broadband reflectance changes and dipole forbidden vibrational modes which in some cases are an order of magnitude stronger than the dipole allowed modes. The experimental data can be explained by a theory developed by Persson, in which the dielectric response of the substrate is seen as playing a crucial role in the dynamics. In particular the relationships between the wavelength of the light, the penetration depth and the electron mean-free path, are critical.

Hirschmugl, C.J.; Lamont, C.L.A.; Williams, G.P. [Brookhaven National Lab., Upton, NY (United States). National Synchrotron Light Source

1995-12-31T23:59:59.000Z

298

Testing CPT Invariance with Antiprotonic Helium Atoms  

Science Conference Proceedings (OSTI)

The structure of matter is related to symmetries at every level of study. CPT symmetry is one of the most important laws of field theory: it states the invariance of physical properties when one simultaneously changes the signs of the charge and of the spatial and time coordinates of free elementary particles. Although in general opinion CPT symmetry is not violated in Nature, there are theoretical attempts to develop CPT-violating models. The Antiproton Decelerator at CERN has been built to test CPT invariance. The ASACUSA experiment compares the properties of particles and antiparticles by studying the antiprotonic helium atom via laser spectroscopy and measuring the mass, charge and magnetic moment of the antiproton as compared to those of the proton.

Horvath, Dezso [KFKI Research Institute for Particle and Nuclear Physics, H-1525 Budapest, Hungary and Institute of Nuclear Research (ATOMKI), Debrecen (Hungary)

2008-08-08T23:59:59.000Z

299

Why is hydrogen's atomic number 1?  

NLE Websites -- All DOE Office Websites (Extended Search)

the number of protons in an atom's nucleus. Hydrogen's atomic number is 1 because all hydrogen atoms contain exactly one proton. Author: Steve Gagnon, Science Education Specialist...

300

NIST: Phys. Lab. Brochure; Atomic Physics Div.  

Science Conference Proceedings (OSTI)

... ultra-cold atoms and investigate atom optics for innovative instrumentation. Measure and analyze spectra of highly ionized atoms for fusion energy ...

Note: This page contains sample records for the topic "atomic absorption spectroscopy" 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

CO Oxidation on supported single Pt atoms - Experimental and Ab Initio density functional studies of CO interaction with Pt atom on theta-alumina(010) surface  

Science Conference Proceedings (OSTI)

Although there are only a few known examples of supported single atoms, they are unique because they bridge the gap between homogenous and heterogeneous catalysis. The metal center is single supported atoms can be isoelectronic with their homogenous catalyst counterpart and may allow mechanistic pathways normally seen in homogenous catalysts. Here, we report CO oxidation activity of mono-disperse single Pt atoms supported on an inert substrate, -alumina (Al2O3), in the presence of stoichiometric oxygen. Since CO oxidation on single Pt atoms cannot occur via a conventional Langmuir-Hinshelwood scheme (L-H scheme) which requires at least one Pt-Pt bond, we have carried out a first principles density functional theoretical study of a proposed pathway which is a variation on the conventional L-H scheme and is inspired by organometallic chemistry of platinum. We find that a single supported Pt atom prefers to bond to O2 over CO. The CO then bonds with the oxygenated Pt atom and forms a carbonate which dissociates to liberate CO2, leaving an oxygen atom on Pt. A subsequent reaction with another CO molecule regenerates the single atom catalyst. An in-situ diffuse reflectance infrared study of CO adsorption on the catalyst s supported single atoms has been carried out to infer information on CO absorption modes and compare the observed spectra with calculated ones for intermediates in the proposed CO oxidation pathway. Our results clearly show that supported Pt single atoms are catalytically active and that this catalytic activity can occur without involving the substrate. Characterization by electron microscopy and X-ray absorption studies of the mono-disperse Pt/ -Al2O3, synthesized by solution methods, are also presented.

Narula, Chaitanya Kumar [ORNL; Debusk, Melanie Moses [ORNL; Yoon, Mina [ORNL; Allard Jr, Lawrence Frederick [ORNL; Mullins, David R [ORNL; Wu, Zili [ORNL; Yang, Xiaofan [ORNL; Veith, Gabriel M [ORNL; Stocks, George Malcolm [ORNL

2013-01-01T23:59:59.000Z

302

Atomic data for fusion  

DOE Green Energy (OSTI)

This report provides a handbook of recommended cross-section and rate-coefficient data for inelastic collisions between hydrogen, helium and lithium atoms, molecules and ions, and encompasses more than 400 different reactions of primary interest in fusion research. Published experimental and theoretical data have been collected and evaluated, and the recommended data are presented in tabular, graphical and parametrized form. Processes include excitation and spectral line emission, charge exchange, ionization, stripping, dissociation and particle interchange reactions. The range of collision energies is appropriate to applications in fusion-energy research.

Hunter, H.T.; Kirkpatrick, M.I.; Alvarez, I.; Cisneros, C.; Phaneuf, R.A. (eds.) [eds.; Barnett, C.F.

1990-07-01T23:59:59.000Z

303

Atomic-Scale Structure of Al2O3-ZrO2 Mixed Oxides Prepared by Laser Ablation  

Science Conference Proceedings (OSTI)

By means of x-ray diffractometry (XRD) and X-ray absorption fine structure spectroscopy, the phase composition and atomic structure of laser evaporated ZrO2 and ZrO2-Al2O3 nanopowders have been studied. The results indicate that pure ZrO2 exists in the form of tetragonal structure, Al2O3 doped ZrO2 nanoparticles, however, have cubic structure. Compared to bulk tetragonal ZrO2, pure tetragonal ZrO2 nanoparticles have a shorter Zr-O- and Zr-Zr shell, indicating that the lattice contracts with decreasing particle size. For Al2O3 doped ZrO2 solid solution, the distances of first Zr-O and Zr-Zr (Al) coordination decrease with increasing solid solubility. The disorder degree of the ZrO2 lattice increases with increasing solid solubility. The coevaporated ZrO2-Al2O3 is quickly solidified into amorphous phase when it is ablated in a higher pressure. The amorphous phase contains Zr-O-Zr (Al) clusters and has shorter Zr-O distance and tower Zr-O coordination number.

Yang Xiuchun [College of Materials Science and Engineering, Tongji University, Shanghai 200092 (China); Dubiel, M. [Department of Physics, Martin Luther University of Halle, D-06108 Halle (Germany); Hofmeister, H. [Max Planck Institute of Microstructure Physics, Weinberg 2, D-06120 Halle (Germany); Riehemann, W. [Department of Materials Science and Engineering, Clausthal University of Technology (Germany)

2007-02-02T23:59:59.000Z

304

Synthesis of Pt?Pd Core?Shell Nanostructures by Atomic Layer Deposition: Application in Propane Oxidative Dehydrogenation to Propylene  

Science Conference Proceedings (OSTI)

Atomic layer deposition (ALD) was employed to synthesize supported Pt?Pd bimetallic particles in the 1 to 2 nm range. The metal loading and composition of the supported Pt?Pd nanoparticles were controlled by varying the deposition temperature and by applying ALD metal oxide coatings to modify the support surface chemistry. Highresolution scanning transmission electron microscopy images showed monodispersed Pt?Pd nanoparticles on ALD Al2O3 - and TiO2 -modi?ed SiO2 gel. X-ray absorption spectroscopy revealed that the bimetallic nanoparticles have a stable Pt-core, Pd-shell nanostructure. Density functional theory calculations revealed that the most stable surface con?guration for the Pt? Pd alloys in an H2 environment has a Pt-core, Pd-shell nanostructure. In comparison to their monometallic counterparts, the small Pt?Pd bimetallic core?shell nanoparticles exhibited higher activity in propane oxidative dehydrogenation as compared to their physical mixture.

Lei, Y.; Liu, Bin; Lu, Junling; Lobo-Lapidus, Rodrigo J.; Wu, Tianpin; Feng, Hao; Xia, Xiaoxing; Mane, Anil U.; Libera, Joseph A.; Greeley, Jeffrey P.; Miller, Jeffrey T.; Elam, J. W.

2012-08-20T23:59:59.000Z

305

Absorption Cooling Basics | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Cooling Basics Cooling Basics Absorption Cooling Basics August 16, 2013 - 2:26pm Addthis Absorption coolers use heat rather than electricity as their energy source. Because natural gas is the most common heat source for absorption cooling, it is also referred to as gas-fired cooling. Other potential heat sources include propane, solar-heated water, or geothermal-heated water. Although mainly used in industrial or commercial settings, absorption coolers are commercially available for large residential homes. How Absorption Cooling Works An absorption cooling cycle relies on three basic principles: When a liquid is heated it boils (vaporizes) and when a gas is cooled it condenses Lowering the pressure above a liquid reduces its boiling point Heat flows from warmer to cooler surfaces.

306

Cancer in atomic bomb survivors  

SciTech Connect

This book presents information on the following topics: sampling of atomic bomb survivors and method of cancer detection in Hiroshima and Nagasaki; atomic bomb dosimetry for epidemiological studies of survivors in Hiroshima and Nagasaki; tumor and tissue registries in Hiroshima and Nagasaki; the cancer registry in Nagasaki, with atomic bomb survivor data, 1973-1977; cancer mortality; methods for study of delayed health effects of a-bomb radiation; experimental radiation carcinogenesis in rodents; leukemia, multiple myeloma, and malignant lymphoma; cancer of the thyroid and salivary glands; malignant tumors in atomic bomb survivors with special reference to the pathology of stomach and lung cancer; colorectal cancer among atomic bomb survivors; breast cancer in atomic bomb survivors; and ovarian neoplasms in atomic bomb survirors.

Shigematsu, I.; Kagan, A.

1986-01-01T23:59:59.000Z

307

Quantum-enhanced absorption refrigerators  

E-Print Network (OSTI)

Thermodynamics is a branch of science blessed by an unparalleled combination of generality of scope and formal simplicity. Based on few natural assumptions together with the four laws, it sets the boundaries between possible and impossible in macroscopic aggregates of matter. This triggered groundbreaking achievements in physics, chemistry and engineering over the last two centuries. Close analogues of those fundamental laws are now being established at the level of individual quantum systems, thus placing limits on the operation of quantum-mechanical devices. Here we study quantum absorption refrigerators, which are driven by heat rather than external work. We establish thermodynamic performance bounds for these machines and investigate their quantum origin. We also show how those bounds may be pushed beyond what is classically achievable, by suitably tailoring the environmental fluctuations via quantum reservoir engineering techniques. Such superefficient quantum-enhanced cooling realises a promising step towards the technological exploitation of autonomous quantum refrigerators.

Luis A. Correa; José P. Palao; Daniel Alonso; Gerardo Adesso

2013-08-19T23:59:59.000Z

308

Backscatter absorption gas imaging system  

DOE Patents (OSTI)

A video imaging system for detecting hazardous gas leaks. Visual displays of invisible gas clouds are produced by radiation augmentation of the field of view of an imaging device by radiation corresponding to an absorption line of the gas to be detected. The field of view of an imager is irradiated by a laser. The imager receives both backscattered laser light and background radiation. When a detectable gas is present, the backscattered laser light is highly attenuated, producing a region of contrast or shadow on the image. A flying spot imaging system is utilized to synchronously irradiate and scan the area to lower laser power requirements. The imager signal is processed to produce a video display.

McRae, Jr., Thomas G. (Livermore, CA)

1985-01-01T23:59:59.000Z

309

Perturbation hydrogen-atom spectrum in deformed space with minimal length  

E-Print Network (OSTI)

We study energy spectrum for hydrogen atom with deformed Heisenberg algebra leading to minimal length. We develop correct perturbation theory free of divergences. It gives a possibility to calculate analytically in the 3D case the corrections to $s$-levels of hydrogen atom caused by the minimal length. Comparing our result with experimental data from precision hydrogen spectroscopy an upper bound for the minimal length is obtained.

M. M. Stetsko; V. M. Tkachuk

2006-03-06T23:59:59.000Z

310

NIST Atomic Physics Division - 2000  

Science Conference Proceedings (OSTI)

... in the coming decade and have impacts to science in areas as diverse as gamma-ray spectroscopy and the realization of a non-artifact kilogram. ...

311

Control of resonance enhanced multi-photon ionization photoelectron spectroscopy by phase-shaped femtosecond laser pulse  

Science Conference Proceedings (OSTI)

In this paper, we theoretically demonstrate that the (2+1+1) resonance enhanced multi-photon ionization photoelectron spectroscopy in sodium atom can be effectively controlled by shaping femtosecond laser pulse with a {pi} phase step modulation in weak laser field, involving its total photoelectron energy, maximal photoelectron intensity, and spectroscopic bandwidth. Our results show that the total photoelectron energy can be suppressed but not enhanced, the maximal photoelectron intensity can be enhanced and also suppressed, and the photoelectron spectroscopy can be tremendously narrowed. These theoretical results can provide a feasible scheme to achieve the high-resolution photoelectron spectroscopy and study the excited state structure in atomic and molecular systems.

Zhang Shian; Lu Chenhui; Jia Tianqing; Sun Zhenrong [State Key Laboratory of Precision Spectroscopy, and Department of Physics, East China Normal University, Shanghai 200062 (China); Qiu Jianrong [State Key Laboratory of Luminescent Materials and Devices, and Institute of Optical Communication Materials, South China University of Technology, Wushan Road 381, Guangzhou 510640 (China)

2012-11-07T23:59:59.000Z

312

Computation of X-Ray Absorption  

Science Conference Proceedings (OSTI)

... of the absorption at other energies, assuming they ... and at DoE's National Energy Research Scientific ... With the improved efficiency of FeffMPI now in ...

2011-01-21T23:59:59.000Z

313

Absorption Chillers and Heat Pumps - Technology, Applications...  

NLE Websites -- All DOE Office Websites (Extended Search)

applications. The last decade saw intensive research and development efforts of gas-fired absorption systems for both heating and cooling applications in the USA, Europe and Japan....

314

Evaluation of Mg for Local Energy Absorption  

Science Conference Proceedings (OSTI)

The AZ31 material exhibited the best energy absorption performance, .... Effects of Alloying Elements and Cooling Rate on Morphology of Phases in CaO Added

315

Solar selective absorption coatings - Energy Innovation Portal  

A new class of solar selective absorption coatings are disclosed. These coatings comprise a structured metallic overlayer such that the overlayer has a sub-micron ...

316

Linear-response and real-time time-dependent density functional theory studies of core-level near-edge x-ray absorption  

Science Conference Proceedings (OSTI)

We discuss our implementation and application of time-dependent density functional theory (TDDFT) to core-level near-edge absorption spectroscopy, using both linear-response (LR) and real-time (RT) approaches. We briefly describe our restricted window TDDFT (REWTDDFT) approach for core excitations which has also been reported by others groups. This is followed by a detailed discussion of real-time TDDFT techniques tailored to core excitations, including obtaining spectral information through delta-function excitation, post-processing time-dependent signals, and resonant excitation through quasi-monochromatic excitation. We present results for the oxygen K-edge of water and carbon dioxide; the carbon K-edge of carbon dioxide; the ruthenium L3-edge for the hexaamminerutheium(III) ion, including scalar relativistic corrections via the zeroth order regular approximation (ZORA); and the carbon and fluorine K-edges for a series of fluorobenzenes. In all cases, the calculated spectra are found to be in good agreement with experiment, requiring only a uniform shift on the order of a few percent. Real-time TDDFT visualization of excited state charge densities are used to visually examine the nature of each excitation, which gives insight into the effects of atoms bound to the absorbing center.

Lopata, Kenneth A.; Van Kuiken, Benjamin E.; Khalil, Munira; Govind, Niranjan

2012-09-03T23:59:59.000Z

317

2008 Vibrational Spectroscopy  

SciTech Connect

The conference focuses on using vibrational spectroscopy to probe structure and dynamics of molecules in gases, liquids, and interfaces. The goal is to bring together a collection of researchers who share common interests and who will gain from discussing work at the forefront of several connected areas. The intent is to emphasize the insights and understanding that studies of vibrations provide about a variety of systems.

Philip J. Reid

2009-09-21T23:59:59.000Z

318

Questions and Answers - Does gravity affect atoms?  

NLE Websites -- All DOE Office Websites (Extended Search)

and Answers Main Index Next Question (Can you crush atoms?) Can you crush atoms? Does gravity affect atoms? Gravity affects atoms the same way it affects all other matter. Every...

319

Optics and interferometry with atoms and molecules  

E-Print Network (OSTI)

Interference with atomic and molecular matter waves is a rich branch of atomic physics and quantum optics. It started with atom diffraction from crystal surfaces and the separated oscillatory fields technique used in atomic ...

Cronin, Alexander D.

320

Atomic Scale Characterization of Complex Oxide Interfaces  

SciTech Connect

Complex oxides exhibit the most disparate behaviors, from ferroelectricity to high Tc superconductivity, colossal magnetoresistance to insulating properties. For these reasons, oxide thin films are of interest for electronics and the emerging field of spintronics. But epitaxial complex oxide ultrathin films and heterostructures can be significantly affected or even dominated by the presence of interfaces and may exhibit intriguing new physical properties quite different from the bulk. A study of the relations between structure and chemistry at the atomic scale is needed to understand the macroscopic properties of such "interface-controlled" materials. For this purpose, the combination of aberration corrected Z-contrast scanning transmission electron microscopy (STEM) and electron energy loss spectroscopy (EELS) represents a very powerful tool. The availability of sub- ngstr m probes allows a level of unprecedented detail when analyzing not only the interface structure with sensitivity to single atoms, but also the interface chemistry. In this work state of the art STEM-EELS will be applied to the study of different oxide interfaces in heterostructures with titanates, manganites and cuprates based on the perovskite structure.

Varela del Arco, Maria [ORNL; Pennycook, Timothy J [ORNL; Tian, Wei [ORNL; Mandrus, David [ORNL; Pennycook, Stephen J [ORNL; Pena, V. [Universidad Complutense, Spain; Sefrioui, Z. [Universidad Complutense, Spain; Santamaria, J. [Universidad Complutense, Spain

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "atomic absorption spectroscopy" 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

Atomic-Layer Engineering of Oxide Superconductors  

SciTech Connect

Molecular beam epitaxy technique has enabled synthesis of atomically smooth thin films, multilayers, and superlattices of cuprates and other complex oxides. Such heterostructures show high temperature superconductivity and enable novel experiments that probe the basic physics of this phenomenon. For example, it was established that high temperature superconductivity and anti-ferromagnetic phases separate on Angstrom scale, while the pseudo-gap state apparently mixes with high temperature superconductivity over an anomalously large length scale (the 'Giant Proximity Effect'). We review some recent experiments on such films and superlattices, including X-ray diffraction, atomic force microscopy, angle-resolved time of flight ion scattering and recoil spectroscopy, transport measurements, high resolution transmission electron microscopy, resonant X-ray scattering, low-energy muon spin resonance, and ultrafast photo-induced reflection high energy electron diffraction. The results include an unambiguous demonstration of strong coupling of in-plane charge excitations to out-of-plane lattice vibrations, a discovery of interface high temperature superconductivity that occurs in a single CuO{sub 2} plane, evidence for local pairs, and establishing tight limits on the temperature range of superconducting fluctuations.

Bozovic I.; Bollinger, A.T.; Eckstein, J.N.; Dubuis, G.; Pavuna, D.

2012-03-01T23:59:59.000Z

322

L. James Rainwater and the Atomic Nuclei  

NLE Websites -- All DOE Office Websites (Extended Search)

L. James Rainwater and the Atomic Nucleus L. James Rainwater and the Atomic Nucleus Resources with Additional Information James Rainwater Courtesy AIP Emilio Segre Visual Archives, W. F. Meggers Gallery of Nobel Laureates "During W.W. II, I [James Rainwater] worked ... [on the] Manhattan Project, mainly doing pulsed neutron spectroscopy using the small Columbia cyclotron. ... [Maria Geoppert-Mayer] shell model suggestion in 1949 was a great triumph and fitted my belief that a nuclear shell model should represent a proper approach to understanding nuclear structure. Combined with developments of Weizsaker's semi-empirical explanation of nuclear binding, and the Bohr-Wheeler 1939 paper on nuclear fission, emphasizing distorted nuclear shapes, I was prepared to see an explanation of large nuclear quadrupole moments. The full concept came to me in late 1949 when attending a colloquium by Prof. C.H. Townes who described the experimental situation for nuclear quadrupole moments. It was a fortuitous situation made even more so by the fact that I was sharing an office with Aage Bohr that year. We had many discussions of the implications, subsequently very successfully exploited by Bohr, [Ben] Mottelson, and others of the Copenhagen Institute."1

323

Magnetometry with entangled atomic samples  

E-Print Network (OSTI)

We present a theory for the estimation of a scalar or a vector magnetic field by its influence on an ensemble of trapped spin polarized atoms. The atoms interact off-resonantly with a continuous laser field, and the measurement of the polarization rotation of the probe light, induced by the dispersive atom-light coupling, leads to spin-squeezing of the atomic sample which enables an estimate of the magnetic field which is more precise than that expected from standard counting statistics. For polarized light and polarized atoms, a description of the non-classical components of the collective spin angular momentum for the atoms and the collective Stokes vectors of the light-field in terms of effective gaussian position and momentum variables is practically exact. The gaussian formalism describes the dynamics of the system very effectively and accounts explicitly for the back-action on the atoms due to measurement and for the estimate of the magnetic field. Multi-component magnetic fields are estimated by the measurement of suitably chosen atomic observables and precision and efficiency is gained by dividing the atomic gas in two or more samples which are entangled by the dispersive atom-light interaction.

Vivi Petersen; Lars Bojer Madsen; Klaus Molmer

2004-09-28T23:59:59.000Z

324

The energy distribution of atoms in the field of thermal blackbody radiation  

E-Print Network (OSTI)

Using the principle of detailed balance and the assumption on the absorption cross-section consistent with available astrophysical data, we obtain the energy distribution of atoms in the field of thermal blackbody radiation and show that this distribution diverges from the Boltzmann law.

F. V. Prigara

2002-02-06T23:59:59.000Z

325

The energy distribution of atoms in the field of thermal radiation  

E-Print Network (OSTI)

Using the principle of detailed balance and the assumption on the absorption cross-section consistent with available astrophysical data, we obtain the energy distribution of atoms in the field of thermal blackbody radiation and show that this distribution diverges from the Boltzmann law. There is an inversion of the high energy level population at sufficiently high temperatures.

F. V. Prigara

2003-11-24T23:59:59.000Z

326

NIST State-resolved Biomolecular Spectroscopies  

Science Conference Proceedings (OSTI)

State-resolved Spectroscopy of Biomolecules. Summary: ... For examples, see State-resolved terahertz spectroscopy of biomolecules. ...

2012-10-18T23:59:59.000Z

327

A Fast Line-by-Line Method for Atmospheric Absorption Computations: The Automatized Atmospheric Absorption Atlas  

Science Conference Proceedings (OSTI)

A computationally fast line-by-line method for the determination of atmospheric absorption is described. This method is based on the creation of an Automatized Atmospheric Absorption Atlas (4A) covering all possible plausible atmospheric ...

N. A. Scott; A. Chedin

1981-07-01T23:59:59.000Z

328

Atomic Energy Commission Takes Over Responsibility for all Atomic...  

National Nuclear Security Administration (NNSA)

Takes Over Responsibility for all Atomic Energy Programs | National Nuclear Security Administration Our Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear...

329

Atomic total energies: Atomic Ref.Data Elec Struc Cal  

Science Conference Proceedings (OSTI)

... These tables contain the atomic total energies and orbital eigenvalues, for the ground electronic configuration of the elements H ... Definition of format ...

330

Atomic total energies: Atomic Ref. Data Elec. Struc. Cal.  

Science Conference Proceedings (OSTI)

... These tables contain the atomic total energies and orbital eigenvalues, for the ground electronic configuration of the elements H ... Definition of format ...

331

Laser Cooling and Cold Atomic Matter  

Science Conference Proceedings (OSTI)

Laser Cooling and Cold Atomic Matter: to advance the understanding and applications of cold atomic matter, including ...

2012-05-30T23:59:59.000Z

332

NIST - Atomic Energy Levels and Spectra Bibliographic ...  

Science Conference Proceedings (OSTI)

... in this database are from Bibliography on Atomic Energy Levels and ... references to atomic transition probabilities, line intensities, or broadening. ...

333

Populations of metastable and resonant argon atoms in radio frequency magnetron plasmas used for deposition of indium-zinc-oxide films  

Science Conference Proceedings (OSTI)

This work reports optical absorption spectroscopy measurements of the number density of Ar atoms in resonant ({sup 3}P{sub 1}, {sup 1}P{sub 1}) and metastable ({sup 3}P{sub 2}, {sup 3}P{sub 0}) states in rf magnetron sputtering plasmas used for the deposition of ZnO-based thin films. While the density of Ar {sup 3}P{sub 2} and {sup 3}P{sub 0} was fairly independent of pressure in the range of experimental conditions investigated, the density of Ar {sup 3}P{sub 1} and {sup 1}P{sub 1} first sharply increased with pressure and then reached a plateau at values close to those of the {sup 3}P{sub 2} and {sup 3}P{sub 0} levels at pressures above about 50 mTorr. At such pressures, ultraviolet radiation from resonant states becomes trapped such that these levels behave as metastable states. For a self-bias voltage of -115 V and pressures in the 5-100 mTorr range, similar number densities of Ar resonant and metastable atoms were obtained for Zn, ZnO, and In{sub 2}O{sub 3} targets, suggesting that, over the range of experimental conditions investigated, collisions between these excited species and sputtered Zn, In, and O atoms played only a minor role on the discharge kinetics. The metastable-to-ground state number density ratios were also fitted to the predictions of a global model using the average electron temperature, T{sub e}, as the only adjustable parameter. For all targets examined, the values of T{sub e} deduced from this method were in excellent agreement with those obtained from Langmuir probe measurements.

Maaloul, L.; Morel, S.; Stafford, L. [Departement de Physique, Universite de Montreal, Montreal, Quebec, H3C 3J7 (Canada)

2012-03-15T23:59:59.000Z

334

ATOMIC ENERGY COMMISSION  

Office of Legacy Management (LM)

' ' ATOMIC ENERGY COMMISSION Frank K. Pittman, Director, bivisioa of Waste &&gement and s- portation, Headquarters j CONTAMItUTED RX-AEC-OWNED OR LEASED FACILITIES' This memorandum responds to your TWX certain information on the above subject. the documentation necessary to answer your available due to the records disposal vailing at the time of release or From records that are available and from disc&ions with most familiar with the transfer operations, &have the current radiological conditibn of transferred property is adequate under present standards. The following tabulations follow the format suggested in your TWX and are grouped to an operations or contract r+ponsibility. A,I Ex-AEC Storage Sites - I r:/ National Stockpile Site '(NSS) and OperatEonal

335

X-ray Diagnostics of Broad Absorption Line Quasar Geometry  

E-Print Network (OSTI)

A new generation of sensitive X-ray measurements are indicating that the existence of X-ray attenuation column densities, $N_{H}>10^{24}\\mathrm{cm}^{-2}$ is quite common amongst broad absorption line quasars (BALQSOs). This is significant to the geometry of the broad absorption line (BAL) outflow. In particular, such an X-ray shield also shields equatorial accretion disk winds from the UV, thereby preventing high velocity equatorial outflows from being launched. By contrast, bipolar winds initiated by continuum radiation pressure from the funnel of a slim accretion disk flare outward (like a trumpet) and offer vastly different absorbing columns to the X-ray and UV emission which are emitted from distinct regions of the disk, $\\sim 6M$ and $\\sim 10M-40M$, respectively (where $M$ is the radius of the black hole). Recent numerical work indicates that it is also possible to launch bipolar outflows from the inner regions of a thin disk. The recent discovery with VLBI that the Galactic analog of a BALQSO, the X-ray binary Circinus X-1 (with high velocity P Cygni X-ray absorption lines) is viewed virtually along the radio jet axis (and therefore along the spin axis of the black hole and the normal to the accretion disk) has rekindled interest in the bipolar models of BALQSOs. We explore this possibility by studying the nearest BAL QSO, MRK 231. High resolution 2-D optical spectroscopy and VLBI mappings of the radio jet axis indicates that the BAL outflow is parallel to the parsec scale radio jet.

Brian Punsly; Sebastian Lipari

2005-03-09T23:59:59.000Z

336

Cavity-enhanced absorption for optical refrigeration  

E-Print Network (OSTI)

A 20-fold increase over the single path optical absorption is demonstrated with a low loss medium placed in a resonant cavity. This has been applied to laser cooling of Yb:ZBLAN glass resulting in 90% absorption of the incident pump light. A coupled-cavity scheme to achieve active optical impedance matching is analyzed.

Seletskiy, Denis V; Sheik-Bahae, Mansoor

2009-01-01T23:59:59.000Z

337

Tunable Infrared Absorption and Visible Transparency of ...  

parent conducting oxide (TCO), indium tin oxide (ITO).1 At ... and dye-sensitized solar cells, ... energy-dispersive X-ray spectroscopy ...

338

NIST Atomic Spectra Bibliographic Databases  

Science Conference Proceedings (OSTI)

... The Atomic Energy Levels Data Center and Data Center on ... Reference Data Program (SRDP) and by NIST's Systems Integration for Manufacturing ...

2010-10-05T23:59:59.000Z

339

Atomic Devices and Instrumentation Group  

Science Conference Proceedings (OSTI)

... ten millionths of a second over the course of one day, and are paving the way for atomic-level timekeeping in portable, battery-operated systems ...

340

Technical Highlights Atomic Physics Division  

Science Conference Proceedings (OSTI)

... Physics Division is to develop and apply atomic physics research methods ... community, and to produce and critically compile physical reference data ...

2013-06-04T23:59:59.000Z

Note: This page contains sample records for the topic "atomic absorption spectroscopy" 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

Anion photoelectron spectroscopy of radicals and clusters  

SciTech Connect

Anion photoelectron spectroscopy is used to study free radicals and clusters. The low-lying {sup 2}{Sigma} and {sup 2}{Pi} states of C{sub 2n}H (n = 1--4) have been studied. The anion photoelectron spectra yielded electron affinities, term values, and vibrational frequencies for these combustion and astrophysically relevant species. Photoelectron angular distributions allowed the author to correctly assign the electronic symmetry of the ground and first excited states and to assess the degree of vibronic coupling in C{sub 2}H and C{sub 4}H. Other radicals studied include NCN and I{sub 3}. The author was able to observe the low-lying singlet and triplet states of NCN for the first time. Measurement of the electron affinity of I{sub 3} revealed that it has a bound ground state and attachment of an argon atom to this moiety enabled him to resolve the symmetric stretching progression.

Travis, Taylor R.

1999-12-16T23:59:59.000Z

342

Atomic-Resolution STEM at Low Primary Energies  

Science Conference Proceedings (OSTI)

Aberration-corrected scanning transmission electron microscopes (STEMs) can now produce electron probes as small as 1 {angstrom} at 60 keV. This level of performance allows individual light atoms to be imaged in various novel materials including graphene, monolayer boron nitride, and carbon nanotubes. Operation at 60 keV avoids direct knock-on damage in such materials, but some radiation damage often remains, and limits the maximum usable electron dose. Elemental identification by electron energy loss spectroscopy (EELS) is then usefully supplemented by annular dark-field (ADF) imaging, for which the signal is much larger and the spatial resolution significantly better. Because of its strong dependence on the atomic number Z, ADF can be used to identify the chemical type of individual atoms, both heavy and light. We review the instrumental requirements for atomic resolution imaging at 60 keV and lower energies, and we illustrate the kinds of studies that have now become possible by ADF images of graphene, monolayer BN, and single-wall carbon nanotubes, and by ADF images and EEL spectra of carbon nanotubes containing nanopods filled with single atoms of Er. We then discuss likely future developments.

Krivanek, Ondrej L. [Nion Co; Chisholm, Matthew F [ORNL; Dellby, N. [Nion Company, WA; Murfitt, M. F. [Nion Company, WA

2011-01-01T23:59:59.000Z

343

Hydrogen Absorption in Pd-based Nanostructures - Final Report  

DOE Green Energy (OSTI)

Pd is known to absorb hydrogen. Molecules are normally chemisorbed at the surface in a process where the molecule breaks into two hydrogen atoms, and the protons are then absorbed into the bulk. This process consists of electron filling holes in the Pd 4d band near the Fermi energy, which due to the high density of states at the Fermi energy, is an energetically favorable process. Our aim with this project was to determine possible changes in magnetic properties with Pd nm-length-scale thick layers intercalated by magnetic materials. Before the start of this work, the literature indicated that there were several possible scenarios by which this could happen: i) the Pd will be magnetized due to a proximity effect with nearby magnetic layers, resulting in changes in the magnetization due to H2 absorption; ii) some H will be absorbed into the magnetic layers, causing a change in the magnetic exchange interactions; or iii) absorption of H2 will cause an expansion of the lattice, resulting in a magnetoelastic effect which changes the magnetic properties.

David Lederman

2012-10-22T23:59:59.000Z

344

Detection and Quantitative Analysis of Chemical Species in Hanford Tank Materials Using Raman Spectroscopy Technology: FY94Florida State University Raman Spectroscopy Report  

Science Conference Proceedings (OSTI)

This report provides a summary of work completed in FY-94 by FSU to develop and investigate the feasibility of using Raman spectroscopy with Hanford tank waste materials. Raman performance impacts from sample morphology, including the effects of absorption, particle size, density, color and refractive index, are discussed. An algorithm for relative species concentration measurement from Raman data is presented. An Algorithm for applying Raman to tank waste core screening is presented and discussed. A library of absorption and Raman spectra are presented that support this work.

Reich, F.R.

1997-08-11T23:59:59.000Z

345

Absorption chillers: Technology for the future  

SciTech Connect

In an era of heightened awareness of energy efficiency and the associated environmental impacts, many industries worldwide are exploring ``environmentally friendly`` technologies that provide equivalent or improved performance while reducing or eliminating harmful side-effects. The refrigeration and air-conditioning industry, due to its reliance on CFCs and HCFCs, has invested in research in alternatives to the industry standard vapor compression machines. One alternative technology with great promise is chemical absorption. Absorption chillers offer comparable refrigeration output with reduced SO{sub 2}, CO{sub 2}, and NO{sub x} emissions. Absorption chillers do not use CFCs or HCFCs, refrigerants that contribute to ozone depletion and global warming. Additionally, gas-fired absorption chillers can save significant amounts in energy costs when used in combination with a vapor compression chiller in a hybrid system. The hybrid system can take advantage of the comparatively low price of natural gas (per unit ton) and rely on the high performance of vapor compression when electricity prices are lower. The purpose of this article is to provide an introduction for those new to absorption technology as well as a discussion of selected high efficiency cycles, a discussion on the technology of coupling absorption with vapor compression systems to form a hybrid system, and the environmental impacts of absorption.

Garland, P.W. [Oak Ridge National Lab., TN (United States); Garland, R.W. [Dept. of Energy, Washington, DC (United States)

1997-12-31T23:59:59.000Z

346

AtomicNuclear Properties  

NLE Websites -- All DOE Office Websites (Extended Search)

HTML_PAGES HTML_PAGES This AtomicNuclearProperties page is under intermittent development. Suggestions and comments are welcome. Please report errors. Chemical elements: For entries in red, a pull-down menu permits selection of the physical state. Cryogenic liquid densties are at the boiling point at 1 atm. 0n 1Ps 1H 2He 3Li 4Be 5B 6C 7N 8O 9F 10Ne 11Na 12Mg 13Al 14Si 15P 16S 17Cl 18Ar 19K 20Ca 21Sc 22Ti 23V 24Cr 25Mn 26Fe 27Co 28Ni 29Cu 30Zn 31Ga 32Ge 33As 34Se 35Br 36Kr 37Rb 38Sr 39Y 40Zr 41Nb 42Mo 43Tc 44Ru 45Rh 46Pd 47Ag 48Cd 49In 50Sn 51Sb 52Te 53I 54Xe 55Cs 56Ba 57La 72Hf 73Ta 74W 75Re 76Os 77Ir 78Pt 79Au 80Hg 81Tl 82Pb 83Bi 84Po 85At 86Rn 87Fr 88Ra 89Ac 104Rf 105Db 106Sg 107Bh 108Hs 109Mt 110Ds 111Rg 112 113 114 115 116 mt 118

347

Atomic Energy for Military Purposes  

E-Print Network (OSTI)

Atomic Energy for Military Purposes: The Official Report on the Development of the Atomic Bomb member of the project, to draft a report about its activities. Smyth completed the report in the summer, in a censored version. On August 11, 1945, five days after the Allies dropped the first nuclear bomb on Japan

Landweber, Laura

348

THE DEVELOPMENT OF ATOMIC LAW  

SciTech Connect

Since a uniform federal statute hss not been passed in the German Federal Republic, the development of atomic law has centered around the formation of the Federal Ministry for Atomic Affairs, appeal to the German Commission, and the enactment of temporary laws in several of the states. (J.S.R.)

Fischerhof, H.

1958-08-01T23:59:59.000Z

349

The Effect Of Low Earth Orbit Atomic Oxygen Exposure On Phenylphosphine Oxide-Containing Polymers  

E-Print Network (OSTI)

Thin films of phenylphosphine oxide-containing polymers were exposed to low Earth orbit aboard a space shuttle flight (STS-85) as part of flight experiment designated Evaluation of Space Environment and Effects on Materials (ESEM). This flight experiment was a cooperative effort between the NASA Langley Research Center (LaRC) and the National Space Development Agency of Japan (NASDA). The thin film samples described herein were part of an atomic oxygen exposure experiment (AOE) and were exposed to primarily atomic oxygen (~1 X 10 19 atoms/cm 2 ). The thin film samples consisted of three phosphine oxide containing polymers (arylene ether, benzimidazole and imide). Based on post-flight analyses using atomic force microscopy, X-ray photoelectron spectroscopy, and weight loss data, it was found that atomic oxygen exposure of these materials efficiently produces a phosphate layer at the surface of the samples. This layer provides a barrier towards further attack by AO. Consequently, th...

John Connell National; John W. Connell

1999-01-01T23:59:59.000Z

350

Charmonium and Light Meson Spectroscopy  

E-Print Network (OSTI)

This talk reviews recent experimental results on selected topics in the spectroscopy of charmonia, charmonium-like states and light mesons.

Kai Zhu

2012-12-10T23:59:59.000Z

351

Atomic, Molecular & Optical Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Atomic, Molecular and Optical Sciences Atomic, Molecular and Optical Sciences The goal of the program is to understand the structure and dynamics of atoms and molecules using photons and ions as probes. The current program is focussed on studying inner-shell photo-ionization and photo-excitation of atoms and molecules, molecular orientation effects in slow collisions, slowing and cooling molecules, and X-ray photo-excitation of laser-dressed atoms. The experimental and theoretical efforts are designed to break new ground and to provide basic knowledge that is central to the programmatic goals of the Department of Energy (DOE). Unique LBNL facilities such as the Advanced Light Source (ALS), the ECR ion sources at the 88-inch cyclotron, and the National Energy Research Scientific Computing Center (NERSC) are

352

Spectral Emission of Moving Atom  

E-Print Network (OSTI)

A renewed analysis of the H.E. Ives and G.R. Stilwell's experiment on moving hydrogen canal rays (J. Opt. Soc. Am., 1938, v.28, 215) concludes that the spectral emission of a moving atom exhibits always a redshift which informs not the direction of the atom's motion. The conclusion is also evident from a simple energy relation: atomic spectral radiation is emitted as an orbiting electron consumes a portion of its internal energy on transiting to a lower-energy state which however has in a moving atom an additional energy gain; this results in a redshift in the emission frequency. Based on auxiliary experimental information and a scheme for de Broglie particle formation, we give a vigorous elucidation of the mechanism for deceleration radiation of atomic electron; the corresponding prediction of the redshift is in complete agreement with the Ives and Stilwell's experimental formula.

J. X. Zheng-Johansson

2006-06-17T23:59:59.000Z

353

Atomic Frequency standards Based on Pulsed Coherent Light Storage  

E-Print Network (OSTI)

We propose a new scheme of microwave frequency standards based on pulsed coherent optical information storage. Unlike the usual frequency reference where the Ramsey fringe is printed on the population of a certain state, we print the Ramsey fringe on the coherence. Then the coherence is detected in the form of a retrieval light. The central line of the Ramsey fringe can be used as a frequency reference in an absorption-cell-based atomic frequency standard. This scheme is free of light shifts as the interrogating process is separated from the optical pumping processes, and the cavity pulling effect is negligible due to the low Q requirement. Encoding the Ramsey interference into the retrieval light pulse has the merit of high signal to noise ratio and the estimated frequency stability of shot noise limit is about $2\\times10^{-14}$ in 1 second, this scheme is promising for building small, compact and stable atomic frequency standards.

Yan, Bo; Wang, Yuzhu

2008-01-01T23:59:59.000Z

354

Anticipating the atom: popular perceptions of atomic power before Hiroshima  

E-Print Network (OSTI)

Before Hiroshima made the Bomb an object of popular concern, possible implications and applications of atomic physics had been discussed in the public forum. The new science of X-rays and radium promised the possibilities of unlimited energy and the transmutation of elements in the two decades leading up to World War 1. During the twenties, as scientific method struggled to keep pace with atomic theory, discussion centered on the feasibility of atomic disintegration as an energy source and the many uses of radium. The 1927 case of the New Jersey Radium Dial Painters, who sued their employers for compensation after contracting radium poisoning, revealed a dark side to the new science, that, along with the development of artificial radioactive isotopes by the Jollot-Curies in Paris, and, in Italy, Enrico Fenni's neutron bombardment experiments, sobered attitudes toward the ever-increasing probability of atomic power. When Otto Hahn finally split the atom in 1938, it opened the way to the practical industrial use of atomic fission, and stimulated a flurry of newspaper and magazine articles before World War 11 brought about censorship. Popular entertainment through 1945 reflects the extent to which atomic power had entered the public awareness. Atomic themes and motifs appeared in English language fiction as early as 1895, as did discussions of the social implications of the new science. Such popular culture imagery, including motion pictures and comic book superheroes, that presented the atom to mass audiences provide insight into the popular perceptions at the time, and to the shaping of attitudes toward the Bomb after Hiroshima.

d'Emal, Jacques-Andre Christian

1994-01-01T23:59:59.000Z

355

Application of Raman spectroscopy to high-temperature analytical measurements  

Science Conference Proceedings (OSTI)

There are numerous analytical applications of scatter-emission and/or absorption spectroscopy applied to liquids and solids at 0 to 350 C. This paper describes an all-silica fiberoptic probe which is useful for spectral analyses from 0 to 1600 K and can be used in harsh chemical environments. The probe has been used for Raman spectral analyses of many molten salt and solid material systems to 1000 C. It has applications for such studies at higher temperature ranges. The instrumentation required along with the demonstrated and proposed applications of the all-silica probe are presented and discussed.

Young, J.P.; Dai, S.; Lee, Y.; Xizo, H.

1997-01-01T23:59:59.000Z

356

Nonlinear optical spectroscopy of diamond surfaces  

DOE Green Energy (OSTI)

Second harmonic generation (SHG) and infrared-visible sum frequency generation (SFG) spectroscopies have been shown to be powerful and versatile for studying surfaces with submonolayer sensitivity. They have been used in this work to study bare diamond surfaces and molecular adsorption on them. In particular, infrared-visible SFG as a surface vibrational spectroscopic technique has been employed to identify and monitor in-situ surface bonds and species on the diamond (111) surface. The CH stretch spectra allow us to investigate hydrogen adsorption, desorption, abstraction, and the nature of the hydrogen termination. The C(111) surface dosed with atomic hydrogen was found to be in a monohydride configuration with the hydrogen atoms situated at top-sites. The ratio of the abstraction rate to the adsorption rate was appreciable during atomic hydrogen dosing. Kinetic parameters for thermal desorption of H on C(111) were determined showing a near first-order kinetics. For the fully H-terminated (111) surface, a large (110 cm{sup {minus}1}) anharmonicity and {approximately}19 psec lifetime were measured for the first-excited CH stretch mode. The bare reconstructed C(111)-(2 {times} l) surface showed the presence of CC stretch modes which were consistent with the Pandey {pi}-bonded chain structure. When exposed to the methyl radical, the SFG spectra of the C(111) surface showed features suggesting the presence of adsorbed methyl species. After heating to sufficiently high temperatures, they were converted into the monohydride species. Preliminary results on the hydrogen-terminated diamond (100) surface are also presented.

Chin, R.P.

1995-04-01T23:59:59.000Z

357

Manhattan Project: Adventures Inside the Atom  

Office of Scientific and Technical Information (OSTI)

ADVENTURES INSIDE THE ATOM ADVENTURES INSIDE THE ATOM General Electric, National Archives (1948) Resources > Library Below is Adventures Inside the Atom, a comic book history of nuclear energy that was produced in 1948 by the General Electric Company. Scroll down to view the full-size images of each page. This publication was produced at the request of the the Assistant Manager for Public Education, Oak Ridge Operations Office, Atomic Energy Commission. It is reproduced here via the National Archives. Adventures Inside the Atom, p. 1 Adventures Inside the Atom, p. 2 Adventures Inside the Atom, p. 3 Adventures Inside the Atom, p. 4 Adventures Inside the Atom, p. 5 Adventures Inside the Atom, p. 6 Adventures Inside the Atom, p. 7 Adventures Inside the Atom, p. 8 Adventures Inside the Atom, p. 9

358

In-situ control system for atomization  

DOE Patents (OSTI)

Melt atomizing apparatus comprising a melt supply orifice for supplying the melt for atomization and gas supply orifices proximate the melt supply orifice for supplying atomizing gas to atomize the melt as an atomization spray is disclosed. The apparatus includes a sensor, such as an optical and/or audio sensor, for providing atomization spray data, and a control unit responsive to the sensed atomization spray data for controlling at least one of the atomizing gas pressure and an actuator to adjust the relative position of the gas supply orifice and melt supply in a manner to achieve a desired atomization spray. 3 figs.

Anderson, I.E.; Figliola, R.S.; Terpstra, R.L.

1995-06-13T23:59:59.000Z

359

In-situ control system for atomization  

DOE Patents (OSTI)

Melt atomizing apparatus comprising a melt supply orifice for supplying the melt for atomization and gas supply orifices proximate the melt supply orifice for supplying atomizing gas to atomize the melt as an atomization spray. The apparatus includes a sensor, such as an optical and/or audio sensor, for providing atomization spray data, and a control unit responsive to the sensed atomization spray data for controlling at least one of the atomizing gas pressure and an actuator to adjust the relative position of the gas supply orifice and melt supply in a manner to achieve a desired atomization spray.

Anderson, Iver E. (Ames, IA); Figliola, Richard S. (Central, SC); Terpstra, Robert L. (Ames, IA)

1995-06-13T23:59:59.000Z

360

Spectroscopy of Solar Neutrinos  

E-Print Network (OSTI)

In the last years, liquid-scintillator detectors have opened a new window for the observation of low-energetic astrophysical neutrino sources. In 2007, the solar neutrino experiment Borexino began its data-taking in the Gran Sasso underground laboratory. High energy resolution and excellent radioactive background conditions in the detector allow the first-time spectroscopic measurement of solar neutrinos in the sub-MeV energy regime. The experimental results of the Beryllium-7 neutrino flux measurements as well as the prospects for the detection of solar Boron-8, pep and CNO neutrinos are presented in the context of the currently discussed ambiguities in solar metallicity. In addition, the potential of the future SNO+ and LENA experiments for high-precision solar neutrino spectroscopy will be outlined.

Michael Wurm; Franz von Feilitzsch; Marianne Goeger-Neff; Tobias Lachenmaier; Timo Lewke; Quirin Meindl; Randoplh Moellenberg; Lothar Oberauer; Walter Potzel; Marc Tippmann; Christoph Traunsteiner; Juergen Winter

2010-04-06T23:59:59.000Z

Note: This page contains sample records for the topic "atomic absorption spectroscopy" 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

Variable effect desorber-resorber absorption cycle  

DOE Patents (OSTI)

An absorption refrigeration system has an intermediate temperature desorber-resorber pair. A valve between the desorber-resorber pair is modulated to control the capacity for load matching.

Biermann, Wendell J. (Fayetteville, NY)

1985-01-01T23:59:59.000Z

362

A New Method for Measuring Aerosol Absorption  

Science Conference Proceedings (OSTI)

A new technique has recently been developed to measure aerosol absorption by means of a microdensitometer. Black particulate material is collected into six spots on membrane filters by a laboratory-tested impaction/concentration technique. Follow-...

B. B. Murphey; S. I. Reynolds

1988-08-01T23:59:59.000Z

363

Supersonic coal water slurry fuel atomizer  

DOE Patents (OSTI)

A supersonic coal water slurry atomizer utilizing supersonic gas velocities to atomize coal water slurry is provided wherein atomization occurs externally of the atomizer. The atomizer has a central tube defining a coal water slurry passageway surrounded by an annular sleeve defining an annular passageway for gas. A converging/diverging section is provided for accelerating gas in the annular passageway to supersonic velocities.

Becker, Frederick E. (Reading, MA); Smolensky, Leo A. (Concord, MA); Balsavich, John (Foxborough, MA)

1991-01-01T23:59:59.000Z

364

INFRARED ABSORPTION SPECTROSCOPY OF CARBON MONOXIDE ON NICKEL FILMS: A LOW TEMPERATURE THERMAL DETECTION TECHNIQUE  

E-Print Network (OSTI)

requirements are a low heat capacity sample and a smallwith hundreds of times the heat capacity of the nickel filmsOnly very thin,low heat capacity samples can be used. A tiny

Bailey, Robert Brian

2011-01-01T23:59:59.000Z

365

Design of an ultraviolet absorption spectroscopy oil concentration sensor for online HVAC measurements  

E-Print Network (OSTI)

Recent advances in the modeling and control of the vapor compression cycle has developed the need for a real time oil concentration rate (OCR) sensor. Because of its ability to give the most accurate online measurements ...

Luz, Roman M. (Roman Manuel), 1979-

2005-01-01T23:59:59.000Z

366

Ultrafast Strong-Field Vibrational Dynamics Studied by Femtosecond Extreme-Ultraviolet Transient Absorption Spectroscopy  

E-Print Network (OSTI)

difference in dispersion caused by the inert gas between thespectral dispersion employing the VCR semi-infinite gasspectral dispersion employing the VCR semi-infinite gas

Hosler, Erik Robert

2013-01-01T23:59:59.000Z

367

X-ray Absorption Spectroscopy Study of Prototype Chemical Systems: Theory vs. Experiment  

E-Print Network (OSTI)

E. Teller, Zeitschrift Fur Physikalische Chemie-AbteilungB-Chemie Der Elementarprozesse Aufbau Der Materie 21 (5/6),Zeitschrift Fur Physikalische Chemie-Abteilung B-Chemie Der

Schwartz, Craig Philip

2010-01-01T23:59:59.000Z

368

Auto-oligomerization and hydration of pyrrole revealed by x-ray absorption spectroscopy  

E-Print Network (OSTI)

E. Teller, Zeitschrift Fur Physikalische Chemie-AbteilungB-Chemie Der Elementarprozesse Aufbau Der Materie 21 (5/6),

Schwartz, Craig P.

2010-01-01T23:59:59.000Z

369

In Situ Electrochemical X-ray Absorption Spectroscopy of Oxygen Reduction Electrocatalysis with High Oxygen Flux  

E-Print Network (OSTI)

(CE) and carbon paper/Pt working electrode (WE) were added to the pouch. (B) The PDMS pouch was very of Pt established a potential dependence of d-band vacancies.12 Later, a similar increase in white in the electrochemical environment could not investigate the effect of added O2 on the Pt structure because of the design

Frenkel, Anatoly

370

Millisecond Kinetics of Nanocrystal Cation Exchange Using Microfluidic X-ray Absorption Spectroscopy  

E-Print Network (OSTI)

nanocrystal with DDA, R CdSe was calculated to be 3.4 nm. Rto measure the kinetics of the CdSe-to-Ag 2 Se nanocrystalthe millisecond mixing of CdSe nanocrystal and Ag + reactant

Chan, Emory M.; Marcus, Matthew A.; Fakra, Sirine; Elnaggar, Mariam S.; Mathies, Richard A.; Alivisatos, A. Paul

2007-01-01T23:59:59.000Z

371

Optical sensor development for MCFCs: HCl detection through wavelength modulation diode laser absorption spectroscopy  

DOE Green Energy (OSTI)

Contaminants in coal gas can degrade the performance of molten carbonate fuel cells. A laser diode sensor and a wavelength modulation spectrometer have been developed capable of detecting, in situ, HCl gas at ppM levels and below on time scales < 1 min, using 25 cm path lengths. Due to intensity and overlap of {sup 18}OCO with P10 transition of HCl, sensitivity is somewhat limited (close to 100 ppB, however) because of limited S/N ratios; this will be improved by eliminating all etalon effects. Alternative HCl lines with possibly reduced spectral interference will be looked for. Detection of H{sub 2}S and H{sub 2}Se will also be investigated. It was found that room-temperature Li/K carbonate can be used as prefilter for HCl contaminants.

Hanold, R.; Funk, D.J.; Palmer, B.A.; Oldenborg, R.C.

1993-11-01T23:59:59.000Z

372

X-RAY ABSORPTION SPECTROSCOPY FOR THE CHEMICAL CHARACTERIZATION OF ATMOSPHERIC AEROSOLS  

E-Print Network (OSTI)

CHARACTERIZATION OF ATMOSPHERIC AEROSOLS J. M. Jaklevic andOF ATMOSPHERIC AEROSOLS X~RAY J. M. Jaklevic and A. C.from the atmospheric aerosol. Modern air sampling technology

Jaklevic, J. M.

2011-01-01T23:59:59.000Z

373

Two photon absorption and third harmonic generation micro- spectroscopy : hemoglobin and other compounds  

E-Print Network (OSTI)

Colored glass filters ( Corning UG-11) were used to blockand colored glass filters (Corning BG-39) were used to blockcolored glass filters (Corning UG-11) were used to block all

Clay, Gabriel Omar

2006-01-01T23:59:59.000Z

374

Questions and Answers - Does an atom smasher really smash atoms?  

NLE Websites -- All DOE Office Websites (Extended Search)

is an accelerator? is an accelerator? Previous Question (What is an accelerator?) Questions and Answers Main Index Next Question (Where and how do you get your electrons for your accelerator?) Where and how do you get yourelectrons for your accelerator? Does an atom smasher really smash atoms? Well, yes, they do, but we now prefer to call them by their less aggression-centered name, "particle harmony disrupters." Of course some atom smashers do much more smashing than others. We use electrons in our accelerator to study the nucleus of an atom. Remember that electrons are negative, as are the electrons surrounding the target. Since like charged particles repel each other, our particles have to have enough energy to blast through that electron cloud to get to the nucleus. The electrons then

375

Broadband Dielectric Spectroscopy on Human Blood  

E-Print Network (OSTI)

Dielectric spectra of human blood reveal a rich variety of dynamic processes. Achieving a better characterization and understanding of these processes not only is of academic interest but also of high relevance for medical applications as, e.g., the determination of absorption rates of electromagnetic radiation by the human body. The dielectric properties of human blood are studied using broadband dielectric spectroscopy, systematically investigating the dependence on temperature and hematocrit value. By covering a frequency range from 1 Hz to 40 GHz, information on all the typical dispersion regions of biological matter is obtained. We find no evidence for a low-frequency relaxation (alpha-relaxation) caused, e.g., by counterion diffusion effects as reported for some types of biological matter. The analysis of a strong Maxwell-Wagner relaxation arising from the polarization of the cell membranes in the 1-100 MHz region (beta-relaxation) allows for the test of model predictions and the determination of various intrinsic cell properties. In the microwave region beyond 1 GHz, the reorientational motion of water molecules in the blood plasma leads to another relaxation feature (gamma-relaxation). Between beta- and gamma-relaxation, significant dispersion is observed, which, however, can be explained by a superposition of these relaxation processes and is not due to an additional delta-relaxation often found in biological matter. Our measurements provide dielectric data on human blood of so far unsurpassed precision for a broad parameter range. All data are provided in electronic form to serve as basis for the calculation of the absorption rate of electromagnetic radiation and other medical purposes. Moreover, by investigating an exceptionally broad frequency range, valuable new information on the dynamic processes in blood is obtained.

M. Wolf; R. Gulich; P. Lunkenheimer; A. Loidl

2011-05-25T23:59:59.000Z

376

Conceptual design of an advanced absorption cycle: the double-effect regenerative absorption refrigeration cycle  

DOE Green Energy (OSTI)

An advanced absorption refrigeration cycle was proposed as a heat-activated refrigeration system. Referred to as the double-effect regenerative absorption cycle of cycle 2R, it improves the performance of the conventional single-effect absorption cycle at high heat source temperatures. The performance of cycle 2R continually improves as input temperatures rise, in contrast to the conventional double-effect absorption cycle that has a sharp cut-off temperature below which it ceases to operate. Cycle 2R operates with two subcycles, the first-effect and the second-effect subcycles.

Dao, K.

1978-09-01T23:59:59.000Z

377

UNITED STATES ATOMIC ENERGY COMMISSION  

Office of Legacy Management (LM)

producing uranium for the Mo"hz,t,a, Projec, can best be qwtcd Irom the Smyth official report - Atomic Energy - . ' .: CCL, + NaCl - ."-l Figure 6. apparatus used in electrcdytic...

378

Single artificial-atom lasing  

E-Print Network (OSTI)

Solid-state superconducting circuits are versatile systems in which quantum states can be engineered and controlled. Recent progress in this area has opened up exciting possibilities for exploring fundamental physics as well as applications in quantum information technology; in a series of experiments it was shown that such circuits can be exploited to generate quantum optical phenomena, by designing superconducting elements as artificial atoms that are coupled coherently to the photon field of a resonator. Here we demonstrate a lasing effect with a single artificial atom - a Josephson-junction charge qubit - embedded in a superconducting resonator. We make use of one of the properties of solid-state artificial atoms, namely that they are strongly and controllably coupled to the resonator modes. The device is essentially different from existing lasers and masers; one and the same artificial atom excited by current injection produces many photons.

O. Astafiev; K. Inomata; A. O. Niskanen; T. Yamamoto; Yu. A. Pashkin; Y. Nakamura; J. S. Tsai

2007-10-04T23:59:59.000Z

379

u. S. Atomic Energy Commission  

Office of Legacy Management (LM)

October 31, 1949 Manager of Operations u. S. Atomic Energy Commission R. 0. Box 30, Ansonia Station New York ES, N. Y. MATERIALS 5+k& hJf Reference: SK:BL Attention: Mr. R. J....

380

Exotic atoms and leptonic conservations  

DOE Green Energy (OSTI)

The major 1989 efforts have been on two aspects of experiments at TRIUMF. One effort was production of muonic hydrogen and muonic deuterium into a vacuum. We study rates relevant to muonic catalyzed fusion, and if there are found an adequate number of muons in the 2s state then we plan to measure precision energies. The second effort was to develop plans for kaonic atoms at the kaon factory. We also completed analyses from the experiments with pionic atoms at LAMPF.

Kunselman, R.

1990-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "atomic absorption spectroscopy" 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

A paradox about an atom and a photon  

E-Print Network (OSTI)

In this article we propose a new relativistic paradox concerning the absorption of a photon by a hydrogen atom. We show that the actual cause of the paradox is one of the hypotheses of Bohr model; therefore, in order to solve the paradox, we have to move away from Bohr model. Our analysis is carried out only in the special relativistic framework, so we are not interested in giving a full quantum mechanical treatment of the problem. We derive some expressions for emission and absorption of photons by atoms, which are in perfect agreement with special relativity, although comparable to the classical Bohr formula with an excellent degree of approximation. Quite interestingly, these expressions are no more invariant under a global shift of energy levels, showing a breaking of classical "gauge invariance" of energy. We stress that, to the best of our knowledge, the present approach has never been considered in literature. At the end we will be able to solve the proposed paradox.

Carlo Maria Scandolo

2013-10-12T23:59:59.000Z

382

Strong Equivalence, Lorentz and CPT Violation, Anti-Hydrogen Spectroscopy and Gamma-Ray Burst Polarimetry  

E-Print Network (OSTI)

The strong equivalence principle, local Lorentz invariance and CPT symmetry are fundamental ingredients of the quantum field theories used to describe elementary particle physics. Nevertheless, each may be violated by simple modifications to the dynamics while apparently preserving the essential fundamental structure of quantum field theory itself. In this paper, we analyse the construction of strong equivalence, Lorentz and CPT violating Lagrangians for QED and review and propose some experimental tests in the fields of astrophysical polarimetry and precision atomic spectroscopy. In particular, modifications of the Maxwell action predict a birefringent rotation of the direction of linearly polarised radiation from synchrotron emission which may be studied using radio galaxies or, potentially, gamma-ray bursts. In the Dirac sector, changes in atomic energy levels are predicted which may be probed in precision spectroscopy of hydrogen and anti-hydrogen atoms, notably in the Doppler-free, two-photon $1s-2s$ and $2s-nd (n \\sim 10)$ transitions.

Graham M. Shore

2004-09-13T23:59:59.000Z

383

Atomic Physics Division 1999 - Future Directions  

Science Conference Proceedings (OSTI)

... lying Rydberg states constitute a "frozen" Rydberg gas. ... of atom interactions in cold atomic gases and Bose ... or optical fields and tight confinement of ...

384

Cavity Quantum Electrodynamics with Ultracold Atoms.  

E-Print Network (OSTI)

??Die vorliegende Arbeit befasst sich mit der Wechselwirkung ultrakalter Atome mit der Mode eines optischen Resonators hoher Gu?te. Die Atome sind dabei in einem periodischen… (more)

Habibian, Hessam

2013-01-01T23:59:59.000Z

385

Program on Technology Innovation: Laser Absorption Sensors for in situ Real-time Monitoring of Syngas Flows  

Science Conference Proceedings (OSTI)

Tunable diode laser absorption spectroscopy (TDLAS) sensors have a long history for real-time, non-intrusive in situ monitoring of combustion systems with sensitive species-specific detection capability, and Stanford University has been a leader in sensor development for practical combustion systems. Most previous sensing has been limited to gas streams near atmospheric pressure that are free of significant opacity from particulate loading. Recently, with the assistance of Electric Power ...

2013-04-24T23:59:59.000Z

386

Dirac Charge Dynamcs in Graphene by Infrared Spectroscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Dirac Charge Dynamcs in Graphene by Infrared Spectroscopy Print Dirac Charge Dynamcs in Graphene by Infrared Spectroscopy Print Graphene-a single layer of carbon atoms arranged in a honeycomb lattice-has very high conductivity that can be tuned by applying a gate voltage. The charge carriers in graphene can travel ballistically over great distances (~1 micron) without scattering. These unusual electronic properties make graphene a promising candidate for future nanoelectronics. Using infrared spectromicroscopy at ALS Beamline 1.4, a group of researchers from the University of California at San Diego, Columbia University, and the ALS has succeeded in probing the dynamical properties of the charge carriers in graphene with an accuracy never before achieved. Their results have uncovered signatures of many-body interactions in graphene and have demonstrated the potential of graphene for novel applications in optoelectronics.

387

Dirac Charge Dynamcs in Graphene by Infrared Spectroscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Dirac Charge Dynamcs in Graphene by Infrared Spectroscopy Print Dirac Charge Dynamcs in Graphene by Infrared Spectroscopy Print Graphene-a single layer of carbon atoms arranged in a honeycomb lattice-has very high conductivity that can be tuned by applying a gate voltage. The charge carriers in graphene can travel ballistically over great distances (~1 micron) without scattering. These unusual electronic properties make graphene a promising candidate for future nanoelectronics. Using infrared spectromicroscopy at ALS Beamline 1.4, a group of researchers from the University of California at San Diego, Columbia University, and the ALS has succeeded in probing the dynamical properties of the charge carriers in graphene with an accuracy never before achieved. Their results have uncovered signatures of many-body interactions in graphene and have demonstrated the potential of graphene for novel applications in optoelectronics.

388

Dirac Charge Dynamcs in Graphene by Infrared Spectroscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Dirac Charge Dynamcs in Graphene Dirac Charge Dynamcs in Graphene by Infrared Spectroscopy Dirac Charge Dynamcs in Graphene by Infrared Spectroscopy Print Wednesday, 29 October 2008 00:00 Graphene-a single layer of carbon atoms arranged in a honeycomb lattice-has very high conductivity that can be tuned by applying a gate voltage. The charge carriers in graphene can travel ballistically over great distances (~1 micron) without scattering. These unusual electronic properties make graphene a promising candidate for future nanoelectronics. Using infrared spectromicroscopy at ALS Beamline 1.4, a group of researchers from the University of California at San Diego, Columbia University, and the ALS has succeeded in probing the dynamical properties of the charge carriers in graphene with an accuracy never before achieved. Their results have uncovered signatures of many-body interactions in graphene and have demonstrated the potential of graphene for novel applications in optoelectronics.

389

JOURNAL OF MOLECULAR SPECTROSCOPY 77,402-428 (1979) Rotational Analysis of the NOz 6125-A Region  

E-Print Network (OSTI)

JOURNAL OF MOLECULAR SPECTROSCOPY 77,402-428 (1979) Rotational Analysis of the NOz 6125-A Region D. Inspection of low resolution NO2 absorption spectra (1) shows a sudden and drastic increase in the complexity University, Stanford, California 94305. 0022-2852/791100402-27$02.00/O Copyright 0 1979 by Academic Press

Zare, Richard N.

390

Ultrafast probing of ejection dynamics of Rydberg atoms and molecular fragments from electronically excited helium nanodroplets  

SciTech Connect

The ejection dynamics of Rydberg atoms and molecular fragments from electronically excited helium nanodroplets are studied with time-resolved extreme ultraviolet ion imaging spectroscopy. At excitation energies of 23.6 {+-} 0.2 eV, Rydberg atoms in n= 3 and n= 4 states are ejected on different time scales and with significantly different kinetic energy distributions. Specifically, n= 3 Rydberg atoms are ejected with kinetic energies as high as 0.85 eV, but their appearance is delayed by approximately 200 fs. In contrast, n= 4 Rydberg atoms appear within the time resolution of the experiment with considerably lower kinetic energies. Major features in the Rydberg atom kinetic energy distributions for both principal quantum numbers can be described within a simple elastic scattering model of localized perturbed atomic Rydberg atoms that are expelled from the droplet due to their repulsive interaction with the surrounding helium bath. Time-dependent kinetic energy distributions of He{sub 2}{sup +} and He{sub 3}{sup +} ions are presented that support the formation of molecular ions in an indirect droplet ionization process and the ejection of neutral Rydberg dimers on a similar time scale as the n= 3 Rydberg atoms.

Buenermann, Oliver; Kornilov, Oleg; Neumark, Daniel M. [Ultrafast X-ray Science Laboratory, Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Department of Chemistry, University of California, Berkeley, California 94720 (United States); Haxton, Daniel J.; Gessner, Oliver [Ultrafast X-ray Science Laboratory, Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Leone, Stephen R. [Ultrafast X-ray Science Laboratory, Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Department of Chemistry, University of California, Berkeley, California 94720 (United States); Department of Physics, University of California, Berkeley, California 94720 (United States)

2012-12-07T23:59:59.000Z

391

Solar absorption aqua-ammonia absorption system simulation base on climate of Malaysia  

Science Conference Proceedings (OSTI)

Solar energy is one of the most well known green sources of energy. This research presents a feasibility study of evacuated solar thermal collector by aqua-ammonia ejector absorption systems as a small scale air conditioning unit. The modeling has been ... Keywords: ejector, evacuated tubes, solar assisted absorption system

Poorya Ooshaksaraei; Sohif Mat; M. Yahya; Ahmad Mahir Razali; Azami Zaharim; K. Sopian

2010-01-01T23:59:59.000Z

392

Electron and hydrogen atom transfer mechanisms for the photoreduction of o-quinones. Visible light induced photoreactions of. beta. -lapachone with amines, alcohols, and amino alcohols  

DOE Green Energy (OSTI)

{beta}-Lapachone (1), a substituted o-naphthoquinone absorbing into the visible ({lambda}{sub max} = 424 nm in benzene), is cleanly and efficiently reduced to the corresponding semiquinone radical upon photolysis in degassed solutions with alcohols, amines, and {beta}-amino alcohols. The course and products of these photoreactions have been followed by NMR, ESR, fluorescence, and absorption spectroscopy. For all three types of reductant the overall reaction involves 2e{sup {minus}} oxidation of the donor, and the quantum efficiencies show a dependence upon quinone concentration indicative of the role of a second dark reduction of 1 by products of the primary photolysis. For amines and amino alcohols the reaction is initiated by single electron transfer quenching of triplet 1. For triethylamine the mechanism is indicated to be a sequence of two electron transfer-proton transfer steps culminating in two semiquinone radicals and the enamine Et{sub 2}NCH{double bond}CH{sub 2}. For amino alcohols a C-C cleavage concurrent with deprotonation of the alcohol (oxidative photofragmentation) occurs, in competition with reverse electron transfer, following the quenching step. For both amines and amino alcohols, limiting efficiencies of reaction approach 2 (for QH{sup {sm bullet}} formation). In contrast, both 2-propanol and benzyl alcohol are oxidized by excited states of 1 with much lower efficiency. The probable mechanism for photooxidation of the alcohols involves a H atom abstraction quenching of the excited state followed by an electron transfer-proton transfer sequence in which a ground-state 1 is reduced. Lower limiting efficiencies for photoreduction of 1 by the alcohols are attributed to inefficiencies of net H-atom transfer in the quenching step. 54 refs., 3 figs., 9 tabs.

Xiaohong Ci; Whitten, D.G. (Univ. of Rochester, NY (USA)); Silveira da Silva, R.; Nicodem, D. (Universidade Federal do Rio de Janeiro (Brazil))

1989-02-15T23:59:59.000Z

393

Posters Long-Pathlength Infrared Absorption Measurements  

NLE Websites -- All DOE Office Websites (Extended Search)

3 3 Posters Long-Pathlength Infrared Absorption Measurements in the 8- to 14-µm Atmospheric Window: Self-Broadening Coefficient Data T. J. Kulp (a) and J. Shinn Geophysics and Environmental Research Program Lawrence Livermore National Laboratory Livermore, California Introduction The accurate characterization of the latent infrared (IR) absorption in the atmospheric window regions continues to be an area of research interest for the global climate modeling community. In the window between 8 and 14 µm, this absorption can be attributed primarily to water vapor. It consists of 1) weak lines originating from the edge of the water vapor pure rotational band (at low wavenumbers) and the trailing P-branch of the υ 2 rovibrational band (at the high-wavenumber boundary of the window); and 2) the

394

Energy Saving with Absorption Refrigeration Technologies  

E-Print Network (OSTI)

Absorption refrigeration technology can be an economical and cost effective means of reducing energy cost and/or improving the efficiency and output of your process. We believe the potential benefits of absorption refrigeration technology have generally been overlooked by the process industry. This paper will address the application of the lithium bromide-water cycle in various energy saving modes. A waste heat powered absorption chiller producing chilled water can reduce energy consumption in a process plant by replacing an existing mechanical refrigeration system or replacing cooling tower water with a lower temperature cooling medium at negligible increase in energy cost. A variety of waste heat sources can be used at temperatures as low as 150 F.

Davis, R. C.

1984-01-01T23:59:59.000Z

395

Probing brain oxygenation with near infrared spectroscopy  

E-Print Network (OSTI)

The fundamentals of near infrared spectroscopy (NIRS) are reviewed. This technique allows to measure the oxygenation of the brain tissue. The particular problems involved in detecting regional brain oxygenation (rSO2) are discussed. The dominant chromophore (light absorber) in tissue is water. Only in the NIR light region of 650-1000 nm, the overall absorption is sufficiently low, and the NIR light can be detected across a thick layer of tissues, among them the skin, the scull and the brain. In this region, there are many absorbing light chromophores, but only three are important as far as the oxygenation is concerned. They are the hemoglobin (HbO2), the deoxy-hemoglobin (Hb) and cytochrome oxidase (CtOx). In the last 20 years there was an enormous growth in the instrumentation and applications of NIRS. . The devices that were used in our experiments were : Somanetics's INVOS Brain Oximeter (IBO) and Toomim's HEG spectrophotometer. The performances of both devices were compared including their merits and draw...

Gersten, Alexander; Raz, Amir; Fried, Robert

2011-01-01T23:59:59.000Z

396

Hadron Spectroscopy in COMPASS  

E-Print Network (OSTI)

The COmmon Muon and Proton Apparatus for Structure and Spectroscopy (COMPASS) is a multi-purpose fixed-target experiment at the CERN Super Proton Synchrotron (SPS) aimed at studying the structure and spectrum of hadrons. In the naive Constituent Quark Model (CQM) mesons are bound states of quarks and antiquarks. QCD, however, predict the existence of hadrons beyond the CQM with exotic properties interpreted as excited glue (hybrids) or even pure gluonic bound states (glueballs). One main goal of COMPASS is to search for these states. Particularly interesting are so called spin-exotic mesons which have J^{PC} quantum numbers forbidden for ordinary q\\bar{q} states. Its large acceptance, high resolution, and high-rate capability make the COMPASS experiment an excellent device to study the spectrum of light-quark mesons in diffractive and central production reactions up to masses of about 2.5 GeV. COMPASS is able to measure final states with charged as well as neutral particles, so that resonances can be studied in different reactions and decay channels. During 2008 and 2009 COMPASS acquired large data samples using negative and positive secondary hadron beams on lH_2, Ni, and Pb targets. The presented overview of the first results from this data set focuses in particular on the search for spin-exotic mesons in diffractively produced \\pi^-\\pi^+\\pi^-, \\eta\\pi, \\eta'\\pi, and \\pi^-\\pi^+\\pi^-\\pi^+\\pi^- final states and the analysis of central-production of \\pi^+\\pi^- pairs in order to study glueball candidates in the scalar sector.

Boris Grube; for the COMPASS Collaboration

2013-01-31T23:59:59.000Z

397

Enhanced absorption cycle computer model. Final report  

DOE Green Energy (OSTI)

Absorption heat pumps have received renewed and increasing attention in the past two decades. The rising cost of electricity has made the particular features of this heat-powered cycle attractive for both residential and industrial applications. Solar-powered absorption chillers, gas-fired domestic heat pumps, and waste-heat-powered industrial temperatures boosters are a few of the applications recently subjected to intensive research and development. The absorption heat pump research community has begun to search for both advanced cycles in various multistage configurations and new working fluid combinations with potential for enhanced performance and reliability. The development of working absorptions systems has created a need for reliable and effective system simulations. A computer code has been developed for simulation of absorption systems at steady state in a flexible and modular form, making it possible to investigate various cycle configurations with different working fluids. The code is based on unit subroutines containing the governing equations for the system`s components and property subroutines containing thermodynamic properties of the working fluids. The user conveys to the computer an image of his cycle by specifying the different subunits and their interconnections. Based on this information, the program calculates the temperature, flow rate, concentration, pressure, and vapor fraction at each state point in the system, and the heat duty at each unit, from which the coefficient of performance (COP) may be determined. This report describes the code and its operation, including improvements introduced into the present version. Simulation results are described for LiBr-H{sub 2}O triple-effect cycles, LiCl-H{sub 2}O solar-powered open absorption cycles, and NH{sub 3}-H{sub 2}O single-effect and generator-absorber heat exchange cycles. An appendix contains the User`s Manual.

Grossman, G.; Wilk, M. [Technion-Israel Inst. of Tech., Haifa (Israel). Faculty of Mechanical Engineering

1993-09-01T23:59:59.000Z

398

Ring resonant cavities for spectroscopy  

DOE Patents (OSTI)

Ring-shaped resonant cavities for spectroscopy allow a reduction in optical feedback to the light source, and provide information on the interaction of both s- and p-polarized light with samples. A laser light source is locked to a single cavity mode. An intracavity acousto-optic modulator may be used to couple light into the cavity. The cavity geometry is particularly useful for Cavity Ring-Down Spectroscopy (CRDS). 6 figs.

Zare, R.N.; Martin, J.; Paldus, B.A.; Xie, J.

1999-06-15T23:59:59.000Z

399

Suspension stirrer for NMR spectroscopy  

DOE Patents (OSTI)

This invention relates to nuclear magnetic resonance (NMR) spectroscopy and, more particularly, to the application of NMR spectroscopy to cell culture samples. A perfusion treatment system maintains microenvironmental conditions about cell spheroids during nuclear magnetic resonance (NMR) examination. A non-magnetic stirring assembly is inserted within a conventional NMR tube to continuously and uniformly supply a perfusate adjacent the spheroids. The perfusate is circulated during the spheroid stirring to maintain known perfusion conditions and eliminate artifacts from the NMR data. 4 figs.

Freyer, J.P; Coulter, J.R.

1990-12-02T23:59:59.000Z

400

Test 4, "NMR Spectroscopy", Chem416, FS93, Dr. Glaser --1 --Chemistry 416 "Spectroscopy"Chemistry 416 "Spectroscopy"  

E-Print Network (OSTI)

Test 4, "NMR Spectroscopy", Chem416, FS93, Dr. Glaser -- 1 -- Chemistry 416 "Spectroscopy "Take Home" Examination "NMR Spectroscopy" Hand-out: Wednesday, December 1, 1993 Collect: Friday Question 4 (13C Inc. Sys.) 20 Total 100 #12;Test 4, "NMR Spectroscopy", Chem416, FS93, Dr. Glaser -- 2

Glaser, Rainer

Note: This page contains sample records for the topic "atomic absorption spectroscopy" 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

Absorption Cooling Optimizes Thermal Design for Cogeneration  

E-Print Network (OSTI)

Contrary to popular concept, in most cases, thermal energy is the real VALUE in cogeneration and not the electricity. The proper consideration of the thermal demands is equal to or more important than the electrical demands. High efficiency two-stage absorption chillers of the type used at Rice University Cogen Plant offer the most attractive utilization of recoverable thermal energy. With a coefficient of performance (COP) up to 1.25, the two-stage, parallel flow absorption chiller can offer over fifty (50) percent more useful thermal energy from the same waste heat source--gas turbine exhaust, I.C. engine exhaust and jacketwater, incinerator exhaust, or steam turbine extraction.

Hufford, P. E.

1986-01-01T23:59:59.000Z

402

Laser isotope separation by multiple photon absorption  

DOE Patents (OSTI)

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

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

1977-01-01T23:59:59.000Z

403

Laser isotope separation by multiple photon absorption  

DOE Patents (OSTI)

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

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

1987-01-01T23:59:59.000Z

404

Laser-Induced Breakdown Spectroscopy System Using a Passively Q-Switched Laser  

NLE Websites -- All DOE Office Websites (Extended Search)

Laser-Induced Breakdown Spectroscopy System Laser-Induced Breakdown Spectroscopy System Using a Passively Q-Switched Laser Opportunity Research is active on the patent-pending technology, titled "Laser-Induced Breakdown Spectroscopy (LIBS) System Using a Passively Q-Switched Laser." This technology is available for licensing and/or further collaborative research from the U.S. Department of Energy's National Energy Technology Laboratory. Overview Atomic spectroscopy systems such as LIBS are used in many applications where the elemental composition of a solid, liquid or gas sample is desired. In addition, this detection technology has the advantage of providing composition data without sample destruction. In LIBS systems, precise timing and control between the laser and the spectrometer detector are

405

Cooling flows, central galaxy--cluster alignments, X-ray absorption and dust  

E-Print Network (OSTI)

We present the analysis of pointed ROSAT PSPC observations of five of the most luminous, intermediate redshift ($0.1 cooling flows. The alignment between CCGs and their host clusters has been investigated. For those clusters with cooling flows, the position angles of the X-ray emission from the clusters and the optical emission from the CCGs agrees within 5 degrees. For the one probable non-cooling flow cluster in the sample, Abell 2208, the alignment is significantly poorer. We examine the evidence for intrinsic X-ray absorption in the clusters. The X-ray spectra for Abell 1068 and Abell 1664 show that the cooling flows in these clusters are intrinsically absorbed by equivalent hydrogen column densities $\\geq 10^{21} atom cm$^{-2}$. The optical spectra of the CCGs in these clusters exhibit substantial intrinsic reddening, at levels consistent with the X-ray absorption results if standard dust to gas ratios are assumed.

S. W. Allen; A. C. Fabian; A. C. Edge; H. Bohringer; D. A. White

1995-03-28T23:59:59.000Z

406

SCHROEDINGER'S CAT IN AN ATOMIC CAGE  

Science Conference Proceedings (OSTI)

... gov SCHROEDINGER'S CAT IN AN ATOMIC CAGE. They ... conditions. Schroedinger cat states are extremely fragile. Any ...

407

Cancer in atomic bomb survivors  

SciTech Connect

Radiation carcinogenesis was first noted in studies of individuals with occupational or therapeutic exposure to radiation. Data from long-term follow-up studies of atomic bomb survivors in Hiroshima and Nagasaki have greatly enhanced our knowledge of radiation carcinogenesis. This book presents current results obtained from epidemiological studies and pathological studies on cancer among atomic bomb survivors. It includes a description of the dosimetry system which is currently being revised. Although many of the details about radiation carcinogenesis remain unknown or uncertain, it is clear that the incidence of radiation-induced cancer among atomic bomb survivors continues unabated 40 years after exposure. Recent increases in occupational and environmental exposure to radiation together with the need for a thorough review of radiation protection standards have led to increased recognition of the importance of research on radiation carcinogenesis and risk assessment.

Shigematsu, I.; Kagan, A.

1986-01-01T23:59:59.000Z

408

Hot atom chemistry and radiopharmaceuticals  

Science Conference Proceedings (OSTI)

The chemical products made in a cyclotron target are a combined result of the chemical effects of the nuclear transformation that made the radioactive atom and the bulk radiolysis in the target. This review uses some well-known examples to understand how hot atom chemistry explains the primary products from a nuclear reaction and then how radiation chemistry is exploited to set up the optimal product for radiosynthesis. It also addresses the chemical effects of nuclear decay. There are important principles that are common to hot atom chemistry and radiopharmaceutical chemistry. Both emphasize short-lived radionuclides and manipulation of high specific activity nuclides. Furthermore, they both rely on radiochromatographic separation for identification of no-carrieradded products.

Krohn, Kenneth A.; Moerlein, Stephen M.; Link, Jeanne M.; Welch, Michael J. [University of Washington, Department of Radiology, Molecular Imaging Center, 1959 NE Pacific St., Box 356004, Seattle, WA 98195-6004 (United States); Washington University, Department of Radiology, Division of Radiological Sciences, 510 South Kingshighway, St. Louis, MO 63110 (United States); University of Washington, Department of Radiology, Molecular Imaging Center, 1959 NE Pacific St., Box 356004, Seattle, WA 98195-6004 (United States); Washington University, Department of Radiology, Division of Radiological Sciences, 510 South Kingshighway, St. Louis, MO 63110 (United States)

2012-12-19T23:59:59.000Z

409

Degeneracy Breaking of Hydrogen Atom  

E-Print Network (OSTI)

The three dimensional rotation group, SO(3), is a symmetry group of the normal hydrogen atom. Each reducible representation of this group can be associated with a degenerate energy level. If this atom is placed in an external magnetic field, the interaction between the orbital magnetic moment with this field will lead to a symmetry breaking where the symmetry group of the atom is a new group distinct from the SO(3) group. This phenomenon describes the normal Zeeman effect, where a degenerate energy level splits into several new energy levels. It is explicitly shown that each of the new energy levels can be associated with an irreducible representation of the new symmetry group.

Agung Trisetyarso; Pantur Silaban

2008-12-22T23:59:59.000Z

410

Dynamical Core-Hole Screening in the X-Ray Absorption Spectra of Hydrogenated Carbon Nanotubes And Graphene  

Science Conference Proceedings (OSTI)

We have calculated the electronic structure and the x-ray absorption (XA) spectrum of a hydrogenated single graphite plane, in order to simulate recent experimental results on hydrogenated single wall carbon nanotubes (SWCNT) as well as hydrogenated graphene. We find that the presence of H induces a substantial component of sp{sup 3} bonding and as a result the {pi} and {pi}* components to the electronic structure vanish. We have calculated a theoretical x-ray absorption spectrum using a multiband version of the Mahan-Nozieres-De Dominicis theory. By making a fitting of the XA signal of C atoms that have H attached to them and C atoms without H in the vicinity we obtain a good representation of the experimental data and we can draw the conclusion that in the experiments [A. Nikitin et al., Phys. Rev. Lett. 95, 225507 (2005)] some 35-50 % H have been absorbed in the SWCNT.

Wessely, O.; /Uppsala U. /Imperial Coll., London; Katsnelson, M.I.; /Nijmegen U.; Nilsson, A.; /SLAC, SSRL /Stockholm U.; Nikitin, A.; Ogasawara, H.; /SLAC, SSRL; Odelius, M.; /Stockholm U.; Sanyal, B.; Eriksson, O.; /Uppsala U.

2009-04-30T23:59:59.000Z

411

Survey of absorption cooling technology in solar applications  

DOE Green Energy (OSTI)

A comprehensive survey of the current state of the absorption cooling technology has been conducted. This survey discusses the basic and applied absorption cooling/heating technology, analyses the current state of the art including the discussion of limitations and possible solutions, identifies areas where promising developments are indicated, lists the current products and activities of the absorption industry, and presents the current RD and D efforts of the U.S. government. The main subjects covered in the survey are as follows: Principles of absorption cooling technology (NH/sub 3/-H/sub 2/O cycle and H/sub 2/O-LiBr Cycle), Adaptation of absorption cooling technology for solar cooling applications, Thermal performance of absorption cooling units, Comparison of NH/sub 3/-H/sub 2/O absorption with H/sub 2/O-LiBr absorption, Commercially available solar absorption units, General trends of the absorption cooling industry toward solar application, Absorption cooling system performance in actual installations, Limitations of absorption cooling technology, Solar-powered absorption heat pumps, and U.S. ERDA activities relating to solar absorption cooling. The treatment of the subjects is intended to be basic and comprehensive in order that the general readers may understand the current aspects of absorption technology in solar cooling applications. 36 references.

Auh, P C

1977-07-01T23:59:59.000Z

412

A New Absorption Cycle: The Single-Effect Regenerative Absoprtion Refrigeration Cycle  

E-Print Network (OSTI)

REGENERATIVE ABSORPTION REFRIGERATION CYCLE ABSTRACT A new absorption cycle , using heat as the energy

Dao, K.

2011-01-01T23:59:59.000Z

413

Supercomputers and atomic physics data  

SciTech Connect

The advent of the supercomputer has dramatically increased the possibilities for generating and using massive amounts of detailed fine structure atomic physics data. Size, speed, and software have made calculations which were impossible just a few years ago into a reality. Further technological advances make future possibilities seem endless. The cornerstone atomic structure codes of R.D. Cowan have been adapted into a single code CATS for use on Los Alamos supercomputers. We provide a brief overview of the problem; and report a sample CATS calculation using configuration interaction to calculate collision and oscillator strengths for over 300,000 transitions in neutral nitrogen. We also discuss future supercomputer needs. 2 refs.

Abdallah, J. Jr.; Clark, R.E.H.

1988-01-01T23:59:59.000Z

414

Investigating Ultrasonic Diffraction Grating Spectroscopy and ...  

Investigating Ultrasonic Diffraction Grating Spectroscopy and Reflection Techniques for Characterization Slurry Properties Investigating Ultrasonic Diffraction Grating

415

Application of photothermal deflection spectroscopy to electrochemical interfaces  

DOE Green Energy (OSTI)

This dissertation discusses the theory and practice of Photothermal Deflection Spectroscopy (PDS, which is also known as probe beam deflection spectroscopy, PBDS, probe deflection technique, and mirage effect spectroscopy) with respect to electrochemical systems. Much of the discussion is also relevant to non-electrochemical systems. PDS can measure the optical absorption spectrum of interfaces and concentration gradients in the electrolyte adjacent to the electrode. These measurements can be made on a wide variety of electrode surfaces and can be performed under dynamic conditions. The first three chapters discuss the theory of the phenomena that can be detected by PDS, and the equipment used in a PDS system. A secondary gradient technique'' is proposed, which places the probe beam on the back of an electrode. The results of a numerical model yield a method for determining the offset of the probe beam from the electrode surface based on the frequency response of the PDS signal. The origin and control of noise in the PDS signal are discussed. A majority of the signal noise appears to be acoustic in origin. The electrochemical oxidation of platinum is used to demonstrate that PDS has sub-monolayer sensitivity necessary to study interfacial chemistry. The results allow us to propose a two-reaction oxidation mechanism: the platinum is electrochemically oxidized to form platinum dihydroxide and dehydrated by a non-electrochemical second-order reaction. The final chapter discusses the relation of PDS to similar and competing techniques, and considers possibilities for the future of the technique.

Rudnicki, J.D.; McLarnon, F.R.; Cairns, E.J.

1992-03-01T23:59:59.000Z

416

Application of photothermal deflection spectroscopy to electrochemical interfaces  

DOE Green Energy (OSTI)

This dissertation discusses the theory and practice of Photothermal Deflection Spectroscopy (PDS, which is also known as probe beam deflection spectroscopy, PBDS, probe deflection technique, and mirage effect spectroscopy) with respect to electrochemical systems. Much of the discussion is also relevant to non-electrochemical systems. PDS can measure the optical absorption spectrum of interfaces and concentration gradients in the electrolyte adjacent to the electrode. These measurements can be made on a wide variety of electrode surfaces and can be performed under dynamic conditions. The first three chapters discuss the theory of the phenomena that can be detected by PDS, and the equipment used in a PDS system. A ``secondary gradient technique`` is proposed, which places the probe beam on the back of an electrode. The results of a numerical model yield a method for determining the offset of the probe beam from the electrode surface based on the frequency response of the PDS signal. The origin and control of noise in the PDS signal are discussed. A majority of the signal noise appears to be acoustic in origin. The electrochemical oxidation of platinum is used to demonstrate that PDS has sub-monolayer sensitivity necessary to study interfacial chemistry. The results allow us to propose a two-reaction oxidation mechanism: the platinum is electrochemically oxidized to form platinum dihydroxide and dehydrated by a non-electrochemical second-order reaction. The final chapter discusses the relation of PDS to similar and competing techniques, and considers possibilities for the future of the technique.

Rudnicki, J.D.; McLarnon, F.R.; Cairns, E.J.

1992-03-01T23:59:59.000Z

417

Supersonic coal water slurry fuel atomizer  

DOE Patents (OSTI)

A supersonic coal water slurry atomizer utilizing supersonic gas velocities to atomize coal water slurry is provided wherein atomization occurs externally of the atomizer. The atomizer has a central tube defining a coal water slurry passageway surrounded by an annular sleeve defining an annular passageway for gas. A converging/diverging section is provided for accelerating gas in the annular passageway to supersonic velocities. 3 figs.

Becker, F.E.; Smolensky, L.S.; Balsavich, J.

1989-11-01T23:59:59.000Z

418

ABSORPTION HEAT PUMP IN THE DISTRICT HEATING  

E-Print Network (OSTI)

#12;ABSORPTION HEAT PUMP IN THE DISTRICT HEATING PLANT Dr.sc.ing. Agnese Lickrastina M.Sc. Normunds European Heat Pump Summit 2013, Nuremberg, 15-16.10.2013 · Riga District Heating company · Operation #12;JSC RGAS SILTUMS · the biggest District Heating company in Latvia and in the Baltic states

Oak Ridge National Laboratory

419

Corrosion inhibitor for aqueous ammonia absorption system  

DOE Patents (OSTI)

A method of inhibiting corrosion and the formation of hydrogen and thus improving absorption in an ammonia/water absorption refrigeration, air conditioning or heat pump system by maintaining the hydroxyl ion concentration of the aqueous ammonia working fluid within a selected range under anaerobic conditions at temperatures up to 425.degree. F. This hydroxyl ion concentration is maintained by introducing to the aqueous ammonia working fluid an inhibitor in an amount effective to produce a hydroxyl ion concentration corresponding to a normality of the inhibitor relative to the water content ranging from about 0.015 N to about 0.2 N at 25.degree. C. Also, working fluids for inhibiting the corrosion of carbon steel and resulting hydrogen formation and improving absorption in an ammonia/water absorption system under anaerobic conditions at up to 425.degree. F. The working fluids may be aqueous solutions of ammonia and a strong base or aqueous solutions of ammonia, a strong base, and a specified buffer.

Phillips, Benjamin A. (Benton Harbor, MI); Whitlow, Eugene P. (St. Joseph, MI)

1998-09-22T23:59:59.000Z

420

Corrosion inhibitor for aqueous ammonia absorption system  

DOE Patents (OSTI)

A method is described for inhibiting corrosion and the formation of hydrogen and thus improving absorption in an ammonia/water absorption refrigeration, air conditioning or heat pump system by maintaining the hydroxyl ion concentration of the aqueous ammonia working fluid within a selected range under anaerobic conditions at temperatures up to 425 F. This hydroxyl ion concentration is maintained by introducing to the aqueous ammonia working fluid an inhibitor in an amount effective to produce a hydroxyl ion concentration corresponding to a normality of the inhibitor relative to the water content ranging from about 0.015 N to about 0.2 N at 25 C. Also, working fluids for inhibiting the corrosion of carbon steel and resulting hydrogen formation and improving absorption in an ammonia/water absorption system under anaerobic conditions at up to 425 F. The working fluids may be aqueous solutions of ammonia and a strong base or aqueous solutions of ammonia, a strong base, and a specified buffer. 5 figs.

Phillips, B.A.; Whitlow, E.P.

1998-09-22T23:59:59.000Z

Note: This page contains sample records for the topic "atomic absorption spectroscopy" 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

Absorption of solar radiation by solar neutrinos  

E-Print Network (OSTI)

We calculate the absorption probability of photons radiated from the surface of the Sun by a left-handed neutrino with definite mass and a typical momentum for which we choose |p_1|=0.2 MeV, producing a heavier right-handed antineutrino. Considering two transitions the \

G. Duplancic; P. Minkowski; J. Trampetic

2003-04-16T23:59:59.000Z

422

Coupled dual loop absorption heat pump  

DOE Patents (OSTI)

A coupled dual loop absorption system which utilizes two separate complete loops. Each individual loop operates at three temperatures and two pressures. This low temperature loop absorber and condenser are thermally coupled to the high temperature loop evaporator, and the high temperature loop condenser and absorber are thermally coupled to the low temperature generator.

Sarkisian, Paul H. (Watertown, MA); Reimann, Robert C. (Lafayette, NY); Biermann, Wendell J. (Fayetteville, NY)

1985-01-01T23:59:59.000Z

423

Laser light absorption with density profile modifications  

SciTech Connect

Two-dimensional computer simulations studied plasma heating by electron plasma waves. The results emphasize the importance of nonlinear steepening of the density profile near the critical density. A typical simulation result is presented in order to illustrate these profile modifications. It is shown that large dc magnetic field generation is an inherent property of the absorption of obliquely-incident light. (MOW)

Kruer, W.; Valeo, E.; Estabrook, K.; Langdon, B.; Lasinski, B.

1974-12-01T23:59:59.000Z

424

Absorption machine with desorber-resorber  

DOE Patents (OSTI)

An absorption refrigeration system utilizing a low temperature desorber and intermediate temperature resorber. The system operates at three temperatures and three pressures to increase the efficiency of the system and is capable of utilizing a lower generator temperature than previously used.

Biermann, Wendell J. (Fayetteville, NY)

1985-01-01T23:59:59.000Z

425

Lesson 6- Atoms to Electricity  

Energy.gov (U.S. Department of Energy (DOE))

Most power plants make electricity by boiling water to make steam that turns a turbine. A nuclear power plant works this way, too. At a nuclear power plant, splitting atoms produce the heat to boil the water. This lesson covers inside the reactor, fission control and electricity generation.

426

Optical fiber-based single-shot picosecond TA spectroscopyL  

NLE Websites -- All DOE Office Websites (Extended Search)

fiber-based single-shot picosecond transient absorption fiber-based single-shot picosecond transient absorption spectroscopy Andrew R. Cook and Yuzhen Shen Rev. Sci. Inst. 80, 073106 (2009). [Find paper at Scitation] Copyright 2009 American Institute of Physics. This article may be downloaded (here) for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The article appeared in Rev. Sci. Inst. 80, 073106 (2009) and may be found at http://link.aip.org/link/?RSI/80/073106 or http://dx.doi.org/10.1063/1.3156048. Abstract: A new type of single-shot transient absorption apparatus is described based on a bundle of optical fibers. The bundle contains 100 fibers of different lengths, each successively giving ~15 ps longer optical delay. Data are collected by imaging light from the exit of the bundle into

427

ROSAT Evidence for Intrinsic Oxygen Absorption in Cooling Flow Galaxies and Groups  

E-Print Network (OSTI)

Using spatially resolved, deprojected ROSAT PSPC spectra of 10 of the brightest cooling flow galaxies and groups with low Galactic column densities we have detected intrinsic absorption over energies ~0.4-0.8 keV in half of the sample. Since no intrinsic absorption is indicated for energies below ~0.4 keV, the most reasonable model for the absorber is collisionally ionized gas at temperatures T=10^{5-6} K with most of the absorption arising from ionized states of oxygen but with a significant contribution from carbon and nitrogen. The soft X-ray emission of this warm gas can explain the sub-Galactic column densities of cold gas inferred within the central regions of most of the systems. Attributing the absorption to ionized gas reconciles the large columns of cold H and He inferred from EINSTEIN and ASCA with the lack of such columns inferred from ROSAT. Within the central ~10-20 kpc, where the constraints are most secure, the estimated mass of the ionized absorber is consistent with most (perhaps all) of the matter deposited by a cooling flow over the lifetime of the flow. Since the warm absorber produces no significant H or He absorption the large absorber masses are consistent with the negligible atomic and molecular H inferred from HI and CO observations of cooling flows. It is also found that if T > ~2x10^5 K then the optical and UV emission implied by the warm gas does not violate published constraints. Finally, we discuss how the prediction of warm ionized gas as the product of mass drop-out in these and other cooling flows can be verified with new CHANDRA and XMM observations. (Abridged)

David A. Buote

2000-01-19T23:59:59.000Z

428

Magneto-Optical Cooling of Atoms  

E-Print Network (OSTI)

We propose an alternative method to laser cooling. Our approach utilizes the extreme brightness of a supersonic atomic beam, and the adiabatic atomic coilgun to slow atoms in the beam or to bring them to rest. We show how internal-state optical pumping and stimulated optical transitions, combined with magnetic forces can be used to cool the translational motion of atoms. This approach does not rely on momentum transfer from photons to atoms, as in laser cooling. We predict that our method can surpass laser cooling in terms of flux of ultra-cold atoms and phase-space density, with lower required laser power and reduced complexity.

Raizen, Mark G; Rochester, Simon; Narevicius, Julia; Narevicius, Edvardas

2013-01-01T23:59:59.000Z

429

Atomic physics and non-equilibrium plasmas  

DOE Green Energy (OSTI)

Three lectures comprise the report. The lecture, Atomic Structure, is primarily theoretical and covers four topics: (1) Non-relativistic one-electron atom, (2) Relativistic one-electron atom, (3) Non-relativistic many-electron atom, and (4) Relativistic many-electron atom. The lecture, Radiative and Collisional Transitions, considers the problem of transitions between atomic states caused by interactions with radiation or other particles. The lecture, Ionization Balance: Spectral Line Shapes, discusses collisional and radiative transitions when ionization and recombination processes are included. 24 figs., 11 tabs.

Weisheit, J.C.

1986-04-25T23:59:59.000Z

430

Quantum spectroscopy of plasmonic nanostructures  

E-Print Network (OSTI)

We use frequency entangled photons, generated via spontaneous parametric down conversion, to measure the broadband spectral response of an array of gold nanoparticles exhibiting Fano-type plasmon resonance. Refractive index sensing of a liquid is performed by measuring the shift of the array resonance. This method is robust in excessively noisy conditions compared with conventional broadband transmission spectroscopy. Detection of a refractive index change is demonstrated with a noise level 70 times higher than the signal, which is shown to be inaccessible with the conventional transmission spectroscopy. Use of low photon fluxes makes this method suitable for measurements of photosensitive bio-samples and chemical substances.

Dmitry A. Kalashnikov; Zhenying Pan; Arseniy I. Kuznetsov; Leonid A. Krivitsky

2013-12-11T23:59:59.000Z

431

Environmental Spectroscopy and Biogeochemistry Facility  

NLE Websites -- All DOE Office Websites (Extended Search)

ES&B Overview ES&B Overview Section 2-2-1 Environmental Spectroscopy and Biogeochemistry Facility The Environmental Spectroscopy and Biogeochemistry (ES&B) Facility focuses on environ- mental molecular science and application of the fundamental concepts of physical chemistry to the study of chemical reactions in heterogeneous natural materials, with an emphasis on soil and subsurface systems. The ES&B Facility staff, along with other Pacific Northwest National Laboratory (PNNL) staff, form a multidisciplinary research team with expertise in chemistry, mineral physics, geochemistry, soil chemistry, microbiology, hydrology, and environmental engineering. Capabilities Capabilities are available for materials characterization, aqueous- and solid-phase speciation

432

SURFACE SEGREGATION STUDIES OF SOFC CATHODES: COMBINING SOFT X-RAYS AND ELECTROCHEMICAL IMPEDENCE SPECTROSCOPY  

DOE Green Energy (OSTI)

A system to grow heteroepitaxial thin-films of solid oxide fuel cell (SOFC) cathodes on single crystal substrates was developed. The cathode composition investigated was 20% strontium-doped lanthanum manganite (LSM) grown by pulsed laser deposition (PLD) on single crystal (111) yttria-stabilized zirconia (YSZ) substrates. By combining electrochemical impedance spectroscopy (EIS) with x-ray photoemission spectroscopy (XPS) and x-ray absorption spectroscopy XAS measurements, we conclude that electrically driven cation migration away from the two-phase gas-cathode interface results in improved electrochemical performance. Our results provide support to the premise that the removal of surface passivating phases containing Sr2+ and Mn2+, which readily form at elevated temperatures even in O2 atmospheric pressures, is responsible for the improved cathodic performance upon application of a bias.

Miara, Lincoln J.; Piper, L.F.J.; Davis, Jacob N.; Saraf, Laxmikant V.; Kaspar, Tiffany C.; Basu, Soumendra; Smith, K. E.; Pal, Uday B.; Gopalan, Srikanth

2010-12-01T23:59:59.000Z

433

Spectroscopy of transient neutral species via negative ion photoelectron spectroscopy  

SciTech Connect

Negative ion photoelectron spectroscopy has been used to study two types of transient neutral species: bound free radicals (NO{sub 2} and NO{sub 3}) and unstable neutral species ((IHI) and (FH{sub 2})). The negative ion time-of-flight photoelectron spectrometer used for these experiments is described in detail.

Weaver, A.

1991-12-01T23:59:59.000Z

434

Spectroscopy of transient neutral species via negative ion photoelectron spectroscopy  

Science Conference Proceedings (OSTI)

Negative ion photoelectron spectroscopy has been used to study two types of transient neutral species: bound free radicals (NO{sub 2} and NO{sub 3}) and unstable neutral species ([IHI] and [FH{sub 2}]). The negative ion time-of-flight photoelectron spectrometer used for these experiments is described in detail.

Weaver, A.

1991-12-01T23:59:59.000Z

435

Overview-absorption/Rankine solar cooling program  

DOE Green Energy (OSTI)

The tasks being performed in the absorption and Rankine program areas run the gamut from basic work on fluids to development of chillers and chiller components, to field and reliability testing of complete cooling systems. In the absorption program, there are six current and five essentially completed projects. In the Rankine program, there are five current projects directly supported by DOE, and three projects funded through and managed by NASA/MSFC (Manned Space Flight Center, Huntsville, Alabama). The basic features of these projects are discussed. The systems under development in five of these current projects have been selected for field testing in the new SOLERAS program, a joint US-Saudi Arabian enterprise. Some technical highlights of the program are presented.

Wahlig, M.; Heitz, A.; Boyce, B.

1980-03-01T23:59:59.000Z

436

Integrated vacuum absorption steam cycle gas separation  

Science Conference Proceedings (OSTI)

Methods and systems for separating a targeted gas from a gas stream emitted from a power plant. The gas stream is brought into contact with an absorption solution to preferentially absorb the targeted gas to be separated from the gas stream so that an absorbed gas is present within the absorption solution. This provides a gas-rich solution, which is introduced into a stripper. Low pressure exhaust steam from a low pressure steam turbine of the power plant is injected into the stripper with the gas-rich solution. The absorbed gas from the gas-rich solution is stripped in the stripper using the injected low pressure steam to provide a gas stream containing the targeted gas. The stripper is at or near vacuum. Water vapor in a gas stream from the stripper is condensed in a condenser operating at a pressure lower than the stripper to concentrate the targeted gas. Condensed water is separated from the concentrated targeted gas.

Chen, Shiaguo (Champaign, IL); Lu, Yonggi (Urbana, IL); Rostam-Abadi, Massoud (Champaign, IL)

2011-11-22T23:59:59.000Z

437

SIMULATION OF A SOLAR ABSORPTION COOLING SYSTEM  

E-Print Network (OSTI)

This paper describes the dynamic modeling of a solar absorption cooling plant that will be built for both research and demonstration purposes by the end of 2007. The synchronizing of cooling loads with solar radiation intensity is an important advantage when utilizing solar energy in air conditioning in buildings. The first part of this work deals with the dynamic modeling of an evacuated tube collector. A field of these collectors feed a single-effect absorption chiller of 35 kW nominal cooling capacity. The simulation model has been done in a modular way under TRNSYS16. In a second part, simulation and optimization of the system has been investigated in order to determine the effect of several parameters (collector area, tank volume...) on chiller performance.

J. P. Praene; D. Morau; F. Lucas; F. Garde; H. Boyer; J. P. Praene

2007-01-01T23:59:59.000Z

438

Diagnosing breast cancer using diffuse reflectance spectroscopy and intrinsic fluorescence spectroscopy  

E-Print Network (OSTI)

Using diffuse reflectance spectroscopy and intrinsic fluorescence spectroscopy, we have developed an algorithm that successfully classifies normal breast tissue, fibrocystic change, fibroadenoma, and infiltrating ductal ...

Fitzmaurice, Maryann

439

UNITED STATES ATOMIC ENERGY COMMISSION  

Office of Legacy Management (LM)

I(S.0 -01: I(S.0 -01: SPECIAL NUCLEAR MATERIAL LlCEWSE Pursuant to the Atomic Energy Act of 1954 and Title 10, Code of Federal Regulations, Chapter 1, Part 70, "Special Nuclear Material Regulations," o. license is hereby issued authorizing the licensee to receive and possess the special nuclear material designated below; to use such special nuclear material for the purpose(s) and at the place(s) designated below; and to transfer such material to persons' authorized to receive it in accordance with the regulations in said Port. This license shall be deemed to contain the conditions specified in Section 70.32(a) of said regulations, and is subject to all applicable rules, regtdations, and orders of the Atomic Energy Commission now or hereafter in

440

Atomic vapor laser isotope separation  

SciTech Connect

Atomic vapor laser isotope separation (AVLIS) is a general and powerful technique. A major present application to the enrichment of uranium for light-water power reactor fuel has been under development for over 10 years. In June 1985 the Department of Energy announced the selection of AVLIS as the technology to meet the nation's future need for the internationally competitive production of uranium separative work. The economic basis for this decision is considered, with an indicated of the constraints placed on the process figures of merit and the process laser system. We then trace an atom through a generic AVLIS separator and give examples of the physical steps encountered, the models used to describe the process physics, the fundamental parameters involved, and the role of diagnostic laser measurements.

Stern, R.C.; Paisner, J.A.

1985-11-08T23:59:59.000Z

Note: This page contains sample records for the topic "atomic absorption spectroscopy" 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

Ultra-sensitive high-precision spectroscopy of a fast molecular ion beam  

Science Conference Proceedings (OSTI)

Direct spectroscopy of a fast molecular ion beam offers many advantages over competing techniques, including the generality of the approach to any molecular ion, the complete elimination of spectral confusion due to neutral molecules, and the mass identification of individual spectral lines. The major challenge is the intrinsic weakness of absorption or dispersion signals resulting from the relatively low number density of ions in the beam. Direct spectroscopy of an ion beam was pioneered by Saykally and co-workers in the late 1980s, but has not been attempted since that time. Here, we present the design and construction of an ion beam spectrometer with several improvements over the Saykally design. The ion beam and its characterization have been improved by adopting recent advances in electrostatic optics, along with a time-of-flight mass spectrometer that can be used simultaneously with optical spectroscopy. As a proof of concept, a noise-immune cavity-enhanced optical heterodyne molecular spectroscopy (NICE-OHMS) setup with a noise equivalent absorption of {approx}2 x 10{sup -11} cm{sup -1} Hz{sup -1/2} has been used to observe several transitions of the Meinel 1-0 band of N{sub 2}{sup +} with linewidths of {approx}120 MHz. An optical frequency comb has been used for absolute frequency calibration of transition frequencies to within {approx}8 MHz. This work represents the first direct spectroscopy of an electronic transition in an ion beam, and also represents a major step toward the development of routine infrared spectroscopy of rotationally cooled molecular ions.

Mills, Andrew A.; Siller, Brian M.; Porambo, Michael W.; Perera, Manori; Kreckel, Holger [Department of Chemistry, University of Illinois, Urbana, Illinois 61801 (United States); McCall, Benjamin J. [Department of Chemistry, University of Illinois, Urbana, Illinois 61801 (United States); Departments of Physics and Astronomy, University of Illinois, Urbana, Illinois 61801 (United States)

2011-12-14T23:59:59.000Z

442

Triple effect absorption chiller utilizing two refrigeration circuits  

Science Conference Proceedings (OSTI)

This patent describes a heat absorption method for an absorption chiller. It comprises: providing a firs absorption system circuit for operation within a first temperature range, providing a second absorption system circuit for operation within a second temperature range; heat exchanging refrigerant and absorber solution; thermal communication with an external heat load. This patent describes a heat absorption apparatus for use as an absorption chiller. It includes: a first absorption system circuit for operation within a first temperature range; a second absorption system circuit for operation within a second temperature range which has a lower maximum temperature relative to the first temperature range; the first circuit having generator means, condenser means, evaporator means, and absorber means operatively connected together; the second circuit having generator means condenser means, evaporator means, and absorber means operative connected together; and the first circuit condenser means and the first circuit absorber means being in heat exchange communication with the second circuit generator means.

DeVault, R.C.

1988-03-22T23:59:59.000Z

443

Ultrabroadband light absorption by a sawtooth anisotropic metamaterial slab  

E-Print Network (OSTI)

We present an ultrabroadband thin-film infrared absorber made of sawtoothed anisotropic metamaterial. Absorptivity of higher than 95% at normal incidence is supported in a wide range of frequencies, where the full absorption ...

Cui, Yanxia

444

Solar Radiation Absorption due to Water Vapor: Advanced Broadband Parameterizations  

Science Conference Proceedings (OSTI)

Accurate parameterizations for calculating solar radiation absorption in the atmospheric column due to water vapor lines and continuum are proposed for use in broadband shortwave radiative transfer codes. The error in the absorption values is ...

Tatiana A. Tarasova; Boris A. Fomin

2000-11-01T23:59:59.000Z

445

The Future of Atomic Energy  

DOE R&D Accomplishments (OSTI)

There is definitely a technical possibility that atomic power may gradually develop into one of the principal sources of useful power. If this expectation will prove correct, great advantages can be expected to come from the fact that the weight of the fuel is almost negligible. This feature may be particularly valuable for making power available to regions of difficult access and far from deposits of coal. It also may prove a great asset in mobile power units for example in a power plant for ship propulsion. On the negative side there are some technical limitations to be applicability of atomic power of which perhaps the most serious is the impossibility of constructing light power units; also there will be some peculiar difficulties in operating atomic plants, as for example the necessity of handling highly radioactive substances which will necessitate, at least for some considerable period, the use of specially skilled personnel for the operation. But the chief obstacle in the way of developing atomic power will be the difficulty of organizing a large scale industrial development in an internationally safe way. This presents actually problems much more difficult to solve than any of the technical developments that are necessary, It will require an unusual amount of statesmanship to balance properly the necessity of allaying the international suspicion that arises from withholding technical secrets against the obvious danger of dumping the details of the procedures for an extremely dangerous new method of warfare on a world that may not yet be prepared to renounce war. Furthermore, the proper balance should be found in the relatively short time that will elapse before the 'secrets' will naturally become open knowledge by rediscovery on part of the scientists and engineers of other countries.

Fermi, E.

1946-05-27T23:59:59.000Z

446

STAR FORMATION IN ATOMIC GAS  

SciTech Connect

Observations of nearby galaxies have firmly established, over a broad range of galactic environments and metallicities, that star formation occurs exclusively in the molecular phase of the interstellar medium (ISM). Theoretical models show that this association results from the correlation between chemical phase, shielding, and temperature. Interstellar gas converts from atomic to molecular only in regions that are well shielded from interstellar ultraviolet (UV) photons, and since UV photons are also the dominant source of interstellar heating, only in these shielded regions does the gas become cold enough to be subject to Jeans instability. However, while the equilibrium temperature and chemical state of interstellar gas are well correlated, the timescale required to reach chemical equilibrium is much longer than that required to reach thermal equilibrium, and both timescales are metallicity-dependent. Here I show that the difference in timescales implies that, at metallicities below a few percent of the solar value, well shielded gas will reach low temperatures and proceed to star formation before the bulk of it is able to convert from atomic to molecular. As a result, at extremely low metallicities, star formation will occur in a cold atomic phase of the ISM rather than a molecular phase. I calculate the observable consequences of this result for star formation in low-metallicity galaxies, and I discuss how some current numerical models for H{sub 2}-regulated star formation may need to be modified.

Krumholz, Mark R., E-mail: krumholz@ucolick.org [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States)

2012-11-01T23:59:59.000Z

447

Enhanced light absorption of solar cells and photodetectors by ...  

Enhanced light absorption of solar cells and photodetectors by diffraction is described. Triangular, rectangular, and blazed subwavelength periodic structures are ...

448

DEVELOPMENTS IN HEAVY QUARKONIUM SPECTROSCOPY  

E-Print Network (OSTI)

­ 1­ DEVELOPMENTS IN HEAVY QUARKONIUM SPECTROSCOPY Written May 2012 by S. Eidelman (Budker Inst. Navas (Univ. Granada), and C. Patrignani (Univ. Genova, INFN). A golden age for heavy quarkonium physics at HERA and the Tevatron matured; and heavy-ion collisions at RHIC opened a window on the deconfinement

449

NMR Spectroscopy Protein-NMR  

E-Print Network (OSTI)

Keywords NMR Spectroscopy Protein-NMR Physical Organic Chemistry » Prof. Dr. Stefan Berger The research group of Prof. Dr. Stefan Berger focuses its work on: 1. Protein-NMR for the genera- tion of Protein-Structures. This includes application of all mod- ern 3D NMR pulse sequences for fully 15 N and 13

Schüler, Axel

450

Role of atomic collisions in fusion  

SciTech Connect

Atomic physics issues have played a large role in controlled fusion research. A general discussion of the present role of atomic processes in both magnetic and inertial controlled fusion work is presented.

Post, D.E.

1982-04-01T23:59:59.000Z

451

NIST Atomic Form Factors: Summary of uncertainties  

Science Conference Proceedings (OSTI)

... element. This "H92 - 3/5CL" value is 1.09 e/atom for uranium or 0.002 e/atom for Z = 6 (ie, 40 % of the dipole correction). ...

452

Laser cooling and trapping of neutral atoms*  

Science Conference Proceedings (OSTI)

... 1 m/s, any gas in equilibrium (other than spin-polarized atomic hydro- ... lattice-trapped atoms, a physical picture with the simplicity and power of the ...

2010-08-23T23:59:59.000Z

453

Outflowing atomic and molecular gas at $z \\sim 0.67$ towards 1504+377  

E-Print Network (OSTI)

We report the detection of OH 1667 MHz and wide HI 21cm absorption at $z \\sim 0.67$ towards the red quasar 1504+377, with the Green Bank Telescope and the Giant Metrewave Radio Telescope. The HI 21cm absorption extends over a velocity range of $\\sim 600$ km/s blueward of the quasar redshift ($z=0.674$), with the new OH 1667 MHz absorption component at $\\sim -430$ \\kms, nearly coincident with earlier detections of mm-wave absorption at $z \\sim 0.6715$. The atomic and molecular absorption appear to arise from a fast gas outflow from the quasar, with a mass outflow rate ${\\dot M} \\sim 12 M_\\odot$ yr$^{-1}$ and a molecular hydrogen fraction $f_{\\rm H_2} \\equiv (N_{\\rm H_2}/N_{\\rm HI}) \\sim 0.2$. The radio structure of 1504+377 is consistent with the outflow arising due to a jet-cloud interaction, followed by rapid cooling of the cloud material. The observed ratio of HCO$^+$ to OH column densities is $\\sim 20$ times higher than typical values in Galactic and high-$z$ absorbers. This could arise due to small-scale ...

Kanekar, Nissim

2007-01-01T23:59:59.000Z

454

Outflowing atomic and molecular gas at $z \\sim 0.67$ towards 1504+377  

E-Print Network (OSTI)

We report the detection of OH 1667 MHz and wide HI 21cm absorption at $z \\sim 0.67$ towards the red quasar 1504+377, with the Green Bank Telescope and the Giant Metrewave Radio Telescope. The HI 21cm absorption extends over a velocity range of $\\sim 600$ km/s blueward of the quasar redshift ($z=0.674$), with the new OH 1667 MHz absorption component at $\\sim -430$ \\kms, nearly coincident with earlier detections of mm-wave absorption at $z \\sim 0.6715$. The atomic and molecular absorption appear to arise from a fast gas outflow from the quasar, with a mass outflow rate ${\\dot M} \\sim 12 M_\\odot$ yr$^{-1}$ and a molecular hydrogen fraction $f_{\\rm H_2} \\equiv (N_{\\rm H_2}/N_{\\rm HI}) \\sim 0.2$. The radio structure of 1504+377 is consistent with the outflow arising due to a jet-cloud interaction, followed by rapid cooling of the cloud material. The observed ratio of HCO$^+$ to OH column densities is $\\sim 20$ times higher than typical values in Galactic and high-$z$ absorbers. This could arise due to small-scale structure in the outflowing gas on sub-parsec scales, which would also explain the observed variability in the HI 21cm line.

Nissim Kanekar; Jayaram N. Chengalur

2007-10-17T23:59:59.000Z

455

Split-flow regeneration in absorptive air separation  

DOE Patents (OSTI)

A chemical absorptive separation of air in multiple stage of absorption and desorption is performed with partial recycle of absorbent between stages of desorption necessary to match equilibrium conditions in the various stages of absorption. This allows reduced absorbent flow, reduced energy demand and reduced capital costs. 4 figs.

Weimer, R.F.

1987-11-24T23:59:59.000Z

456

Gas Powered Air Conditioning Absorption vs. Engine-Drive  

E-Print Network (OSTI)

It used to be that the only alternative to costly electric air conditioning was the double-effect gas-fired absorption chiller/heaters. Beginning in the 1980's, they were the "star" equipment promoted by gas companies throughout the nation. Although not a new technology at the time, neither was the gas engine. But now in the 19901s, gas engine-drive (GED) chillers have "hit" the air conditioning market with a "bang". In the Lone Star Gas Company area in 1995, GED chillers are now being considered in as many projects as are Absorption. units. Where once the only studies being analyzed were absorption vs. electric chiller operation costs. Now, the choice is: Why, Where, and How to choose between gas fired Absorption and GED chillers. WHY Absorption or Engine ? . Absorption uses the most environmentally friendly refrigerant - water. . Absorption chillers are chiller/heaters Absorption chillers are manufactured by the four US major manufacturers Absorption chillers have few moving parts . Engine chillers provide "free" hot water Engine chillers retrofit with DX systems . Engine chillers use less gas per ton WHERE Do Absorption And Engine Chillers Belong? . Absorption: Office buildings, restaurants, industries, churches, universities . Engine: Hospitals, universities, hotels, apartments, industries HOW To Choose Between Absorption And Engine Chillers? Energy cost Operation and maintenance costs Equipment cost Environmental concerns Thermal requirements . Space requirements Staff experience

Phillips, J. N.

1996-01-01T23:59:59.000Z

457

The Nature of Interstellar Gas toward the Pleiades Revealed in Absorption Lines  

E-Print Network (OSTI)

We present high-resolution, high signal to noise absorption-line observations of CN, Ca II, Ca I, CH^+, and CH along twenty lines of sight toward members of the Pleiades. The acquired data enable the most detailed study to date of the interaction between cluster stars and the surrounding interstellar gas. Total equivalent widths are consistent with previous investigations except where weaker features are detected owing to our greater sensitivity. Mean b-values for the molecular species indicate that toward most of the Pleiades CH is associated with the production of CH^+ rather than CN. An analysis of radial velocities reveals a kinematic distinction between ionized atomic gas and molecular and neutral gas. Molecular components are found with velocities in the local standard of rest of either ~ +7 km s^-1 or ~ +9.5 km s^-1, with the higher-velocity components associated with the strongest absorption. Atomic gas traced by Ca II shows a strong central component at v_LSR ~ +7 km s^-1 exhibiting velocity gradient...

Ritchey, A M; Pan, K; Federman, S R; Lambert, D L

2006-01-01T23:59:59.000Z

458

The Nature of Interstellar Gas toward the Pleiades Revealed in Absorption Lines  

E-Print Network (OSTI)

We present high-resolution, high signal to noise absorption-line observations of CN, Ca II, Ca I, CH^+, and CH along twenty lines of sight toward members of the Pleiades. The acquired data enable the most detailed study to date of the interaction between cluster stars and the surrounding interstellar gas. Total equivalent widths are consistent with previous investigations except where weaker features are detected owing to our greater sensitivity. Mean b-values for the molecular species indicate that toward most of the Pleiades CH is associated with the production of CH^+ rather than CN. An analysis of radial velocities reveals a kinematic distinction between ionized atomic gas and molecular and neutral gas. Molecular components are found with velocities in the local standard of rest of either ~ +7 km s^-1 or ~ +9.5 km s^-1, with the higher-velocity components associated with the strongest absorption. Atomic gas traced by Ca II shows a strong central component at v_LSR ~ +7 km s^-1 exhibiting velocity gradients indicative of cloud-cluster interactions. Gas density estimates derived from measured CH/CH^+ column density ratios show good agreement with those inferred from H_2 rotational populations, yielding typical values of n ~ 50 cm^-3. Our models do not include the important time-dependent effects on CH^+ formation which may ultimately be needed to extract physical conditions in these clouds.

A. M. Ritchey; M. Martinez; K. Pan; S. R. Federman; D. L. Lambert

2006-06-27T23:59:59.000Z

459

Towards a high-precision atomic gyroscope  

E-Print Network (OSTI)

In this thesis, I report on the design and construction of the Rubidium Atomic Gyroscope Experiment (RAGE) at Draper Lab.

Van Camp, Mackenzie A. (Mackenzie Anne)

2013-01-01T23:59:59.000Z

460

Argonne Chemical Sciences & Engineering - Institute for Atom...  

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Catalysis & Energy Conversion Electrochemical Energy Storage Nuclear & Environmental Processes National Security Institute for Atom-Efficient Chemical Transformations Center for...

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461

Atomic Scale Deformation Mechanisms of Amorphous Polyethylene ...  

Science Conference Proceedings (OSTI)

Atomic Scale Deformation Mechanisms of Amorphous Polyethylene under Tensile Loading · Atomistic Predictions of Age Hardening in Al-Cu Alloys.

462

NIST Atomic Physics Division 2000 - Technical Highlights  

Science Conference Proceedings (OSTI)

... Astrophysical Quantities," a handbook widely used ... and single-atom chemistry, where controlled ... understanding of fundamental processes occurring ...

463

Hyperfine Structure Measurements of Antiprotonic $^3$He using Microwave Spectroscopy  

E-Print Network (OSTI)

The goal of this project was to measure the hyperfine structure of $\\overline{\\text{p}}^3$He$^+$ using the technique of laser-microwave-laser spectroscopy. Antiprotonic helium ($\\overline{\\text{p}}$He$^+$) is a neutral exotic atom, consisting of a helium nucleus, an electron and an antiproton. The interactions of the angular momenta of its constituents cause a hyperfine splitting ({HFS}) within the energy states of this new atom. The 3\\% of formed antiprotonic helium atoms which remain in a metastable, radiative decay-dominated state have a lifetime of about 1-3~$\\mu$s. This time window is used to do spectroscopic studies. The hyperfine structure of $\\overline{\\text{p}}^4$He$^+$ was already extensively investigated before. From these measurements the spin magnetic moment of the antiproton can be determined. A comparison of the result to the proton magnetic moment provides a test of {CPT} invariance. Due to its higher complexity the new exotic three-body system of $\\overline{\\text{p}}^3$He$^+$ is a cross-check...

Friedreich, Susanne

464

Collisionally Induced Atomic Clock Shifts and Correlations  

E-Print Network (OSTI)

We develop a formalism to incorporate exchange symmetry considerations into the calculation of collisional frequency shifts and blackbody radiation effects for atomic clock transitions using a density matrix formalism. The formalism is developed for both fermionic and bosonic atomic clocks. Results for a finite temperature ${}^{87}$Sr ${}^1S_0$ ($F = 9/2$) atomic clock in a magic wavelength optical lattice are presented.

Y. B. Band; I. Osherov

2010-11-15T23:59:59.000Z

465

Direct speciation of metal and metalloid ions by optical spectroscopies  

DOE Green Energy (OSTI)

Molecular level spectroscopic investigations of organic/inorganic interactions provide important new information on sedimentary geochemistry through the identification of interactions over moderate temperature and pH ranges. Although the official title of this project indicates the use of only optical spectroscopies, a combination of Uv/Vis/IR absorption, Raman scattering, and {sup 29}Si and {sup 13}C nuclear magnetic resonance (NMR) experiments are actually employed. A major advantage of integrating spectroscopic results with diagenesis studies is the ability to directly examine the mechanisms of interactions, even in complex matrices and with competing processes. Furthermore, we are extending these techniques to probe fluid inclusions with micro Raman and luminescence techniques to directly compare laboratory results with natural reservoir systems. 25 refs., 4 figs.

Tait, C.D.; Janecky, D.R.; Clark, D.L.; Ekberg, S.A.; Dixon, P.R.; Musgrave, J.A. (Los Alamos National Lab., NM (United States)); Bennett, P.C. (Texas Univ., Austin, TX (United States). Dept. of Geological Sciences)

1991-01-01T23:59:59.000Z