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1

Modern Records of Atmospheric Oxygen (O2) from Scripps Institution of  

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Atmospheric Trace Gases » Oxygen » Modern Records of Atmospheric Oxygen Atmospheric Trace Gases » Oxygen » Modern Records of Atmospheric Oxygen (O2) from Scripps Institution of Oceanography Modern Records of Atmospheric Oxygen (O2) from Scripps Institution of Oceanography Introduction This page provides an introduction and links to records of atmospheric oxygen (O2) concentrations at nine currently active stations. Records since 1989 are available from Scripps Pier and Alert, Alaska, although these are not continuous. Continuous records from seven stations extend back to 1993, and data for the other two stations (Cold Bay, Alaska and Palmer Station, Antarctica) are available back to the mid 1990s. These data are from remote locations or other locations situated so that they represent averages over large portions of the globe rather than local background sources.

2

Atmospheric Oxygen Binding and Hole Doping in Deformed Graphene on a SiO2 Substrate  

E-Print Network (OSTI)

Using micro-Raman spectroscopy and scanning tunneling microscopy, we study the relationship between structural distortion and electrical hole doping of graphene on a silicon dioxide substrate. The observed upshift of the Raman G band represents charge doping and not compressive strain. Two independent factors control the doping: (1) the degree of graphene coupling to the substrate, and (2) exposure to oxygen and moisture. Thermal annealing induces a pronounced structural distortion due to close coupling to SiO2 and activates the ability of diatomic oxygen to accept charge from graphene. Gas flow experiments show that dry oxygen reversibly dopes graphene; doping becomes stronger and more irreversible in the presence of moisture and over long periods of time. We propose that oxygen molecular anions are stabilized by water solvation and electrostatic binding to the silicon dioxide surface.

Sunmin Ryu; Li Liu; Stephane Berciaud; Young-Jun Yu; Haitao Liu; Philip Kim; George W. Flynn; Louis E. Brus

2010-11-13T23:59:59.000Z

3

Transient Mobility of Oxygen Adatoms upon O2 Dissociation on...  

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Transient Mobility of Oxygen Adatoms upon O2 Dissociation on Reduced TiO2 (110). Transient Mobility of Oxygen Adatoms upon O2 Dissociation on Reduced TiO2 (110). Abstract: Tracking...

4

Stability and Migration of Charged Oxygen Interstitials in ThO2...  

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Stability and Migration of Charged Oxygen Interstitials in ThO2 and CeO2. Stability and Migration of Charged Oxygen Interstitials in ThO2 and CeO2. Abstract: Density functional...

5

Enhanced oxygen evolution activity of IrO2 and RuO2 (100) surfaces  

SciTech Connect

The activities of the oxygen evolution reaction (OER) on IrO2 and RuO2 catalysts are among the highest known to date. However, the intrinsic OER activities of surfaces with defined crystallographic orientations are not well established experimentally. Here we report that the (100) surface of IrO2 and RuO2 is more active than the (110) surface that has been traditionally explored by density functional theory studies. The relation between the OER activity and density of coordinatively undersaturated metal sites exposed on each rutile crystallographic facet is discussed. The surface-orientation dependent activities can guide the design of high-surface-area catalysts with increased activity for electrolyzers, metal-air batteries, and photoelectrochemical water splitting applications.

Stoerzinger, Kelsey [Massachusetts Institute of Technology (MIT)] [Massachusetts Institute of Technology (MIT); Qiao, Liang [ORNL] [ORNL; Biegalski, Michael D [ORNL] [ORNL; Christen, Hans M [ORNL] [ORNL; Shao-Horn, Yang [Massachusetts Institute of Technology (MIT)] [Massachusetts Institute of Technology (MIT)

2014-01-01T23:59:59.000Z

6

GEOCARBSULF: A combined model for Phanerozoic atmospheric O2 and CO2  

Science Journals Connector (OSTI)

A model for the combined long-term cycles of carbon and sulfur has been constructed which combines all the factors modifying weathering and degassing of the GEOCARB III model [Berner R.A., Kothavala Z., 2001. GEOCARB III: a revised model of atmospheric CO2 over Phanerozoic time. Am. J. Sci. 301, 182204] for CO2 with rapid recycling and oxygen dependent carbon and sulfur isotope fractionation of an isotope mass balance model for O2 [Berner R.A., 2001. Modeling atmospheric O2 over Phanerozoic time. Geochim. Cosmochim. Acta 65, 685694]. New isotopic data for both carbon and sulfur are used and new feedbacks are created by combining the models. Sensitivity analysis is done by determining (1) the effect on weathering rates of using rapid recycling (rapid recycling treats carbon and sulfur weathering in terms of young rapidly weathering rocks and older more slowly weathering rocks); (2) the effect on O2 of using different initial starting conditions; (3) the effect on O2 of using different data for carbon isotope fractionation during photosynthesis and alternative values of oceanic ?13C for the past 200 million years; (4) the effect on sulfur isotope fractionation and on O2 of varying the size of O2 feedback during sedimentary pyrite formation; (5) the effect on O2 of varying the dependence of organic matter and pyrite weathering on tectonic uplift plus erosion, and the degree of exposure of coastal lands by sea level change; (6) the effect on CO2 of adding the variability of volcanic rock weathering over time [Berner, R.A., 2006. Inclusion of the weathering of volcanic rocks in the GEOCARBSULF model. Am. J. Sci. 306 (in press)]. Results show a similar trend of atmospheric CO2 over the Phanerozoic to the results of GEOCARB III, but with some differences during the early Paleozoic and, for variable volcanic rock weathering, lower CO2 values during the Mesozoic. Atmospheric oxygen shows a major broad late Paleozoic peak with a maximum value of about 30% O2 in the Permian, a secondary less-broad peak centered near the Silurian/Devonian boundary, variation between 15% and 20% O2 during the Cambrian and Ordovician, a very sharp drop from 30% to 15% O2 at the Permo-Triassic boundary, and a more-or less continuous rise in O2 from the late Triassic to the present.

Robert A. Berner

2006-01-01T23:59:59.000Z

7

A UV light enhanced TiO2/graphene device for oxygen sensing at room temperature  

E-Print Network (OSTI)

A UV light enhanced TiO2/graphene device for oxygen sensing at room temperature Jia Zhang,ab Chao temperature oxygen sensor based on TiO2/graphene device was developed with an enhanced sensing performance­hole pairs in the TiO2 film and the photogenerated electrons were scavenged by graphene and percolated

Cao, Wenwu

8

Interaction of CO2 with Oxygen Adatoms on Rutile TiO2(110). ...  

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CO2 with Oxygen Adatoms on Rutile TiO2(110). Interaction of CO2 with Oxygen Adatoms on Rutile TiO2(110). Abstract: The interactions of CO2 with oxygen adatoms (Oas) on...

9

Two Pathways for Water Interaction with Oxygen Adatoms on TiO2...  

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

tunneling microscopy and density functional theory studies show that oxygen adatoms (Oa), produced during O2 exposure of reduced TiO2(110) surfaces, alter the water dissociation...

10

Oxygen-Isotope Exchange between CO2 and Solid Ti18O2  

Science Journals Connector (OSTI)

Oxygen-Isotope Exchange between CO2 and Solid Ti18O2 ... Analysis of the isotopic composition of the gases produced has revealed ... ...

Svatopluk Civis?; Martin Ferus; Pavel Kuba?t; Marke?ta Zukalova?; Ladislav Kavan

2011-05-17T23:59:59.000Z

11

A Study of Oxygen Vacancy Formation and Annihilation in Submonolayer Coverages of TiO2 Dispersed on MCM-48  

E-Print Network (OSTI)

A Study of Oxygen Vacancy Formation and Annihilation in Submonolayer Coverages of TiO2 Dispersed.932), suggesting the formation of oxygen vacancies. The fraction of Ti that could be reduced increased with TiO2 the TiO2 overlayer as the size of the titania patches increases. The amount of oxygen removed during

Bell, Alexis

12

Active Oxygen on Au/TiO2 Catalysts DOI: 10.1002/anie.201102062 Active oxygen on a Au/TiO2 catalyst Formation, stability and CO  

E-Print Network (OSTI)

1 Active Oxygen on Au/TiO2 Catalysts DOI: 10.1002/anie.201102062 Active oxygen on a Au/TiO2 are the activation of molecular oxygen, the active site for this reaction step, and the nature of the catalytically active oxygen species present under working conditions.[3;9-15] Stiehl et al. had shown that molecularly

Pfeifer, Holger

13

Preparation of Ti O 2 thin films on the inner surface of a quartz tube using atmospheric-pressure microplasma  

Science Journals Connector (OSTI)

Titanium dioxide ( Ti O 2 ) thin films were prepared on the inner surface of a quartz tube with inner and outer diameters of 1 and 3 mm respectively using plasma-enhanced chemical vapor deposition with titanium tetraisopropoxide and oxygen ( O 2 ) as reactants and helium as the carrier gas at atmospheric pressure. A microplasma was generated inside the tube by rf ( 13.56 MHz ) excitation using externally attached parallel-plate electrodes. The characteristics of the depositedfilms were examined by scanning electron microscopy x-ray photoelectron spectroscopy and x-ray diffraction. A typical as-deposited film had an amorphous structure with a smooth surface and was transparent. With increasing O 2 concentration in the plasma gas phase the depositedfilmsurface was covered with a large number of Ti O 2 nanoparticles. However the depositedfilms were a mixture of Ti O 2 and amorphous carbon and showed rough surface in the absence of O 2 in the source gas. The effects of the O 2 concentration in the plasma gas on the characteristics of the deposited Ti O 2 films are discussed on the basis of the analysis of the gas species generated in the plasma using optical emission spectroscopy.

Hiroyuki Yoshiki; Taku Saito

2008-01-01T23:59:59.000Z

14

Oxygen-18 of O2 Records the Impact of Abrupt Climate Change on the Terrestrial Biosphere  

Science Journals Connector (OSTI)

...not preserve reliable atmospheric methane records...continuing to produce deep water. The implication of...O and 18 O/ 16 O of atmospheric O 2 (abstr.)., Proceedings...g., from humid, water-saturated biomes...Education Foundation, and recovery of the Siple Dome...

Jeffrey P. Severinghaus; Ross Beaudette; Melissa A. Headly; Kendrick Taylor; Edward J. Brook

2009-06-12T23:59:59.000Z

15

Oxygen detected in atmosphere of Saturn's moon Dione  

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

Oxygen detected in atmosphere of Saturn's moon Dione Oxygen detected in atmosphere of Saturn's moon Dione Scientists and an international research team have announced discovery of...

16

Oxygen Reduction Catalyzed by AuTiO2 Nanocomposites in Alkaline Media  

Science Journals Connector (OSTI)

Au?TiO2 nanocomposite; oxygen reduction; alkaline media; RRDE; Tafel plot ... In another study, Kim et al.(14) prepared titanium oxide by heat treatment of titanium sheets in the temperature range of 6001000 C, and the best catalysts were identified as those prepared at 900 C where ORR occurred at the potential of about +0.65 V versus RHE in 0.1 M H2SO4. ... In a typical measurement, 1 mg of the AuTiO2 nanocomposite catalysts, 4 mg of carbon powder, and 10 ?L of Nafion were ultrasonically mixed in 1 mL of methanol. ...

Chan Lin; Yang Song; Lixin Cao; Shaowei Chen

2013-11-11T23:59:59.000Z

17

Structure, Properties, and Dynamics of Oxygen Vacancies in Amorphous SiO2 Zhong-Yi Lu,1  

E-Print Network (OSTI)

Structure, Properties, and Dynamics of Oxygen Vacancies in Amorphous SiO2 Zhong-Yi Lu,1 C. J vacancies in SiO2 have long been regarded as bistable, forming a Si-Si dimer when neutral and a puckered configuration when positively charged. We report first-principles calculations of O vacancies in amorphous SiO2

Pantelides, Sokrates T.

18

Deposition of TiO2 thin films by atmospheric plasma post-discharge assisted injection MOCVD  

E-Print Network (OSTI)

Deposition of TiO2 thin films by atmospheric plasma post-discharge assisted injection MOCVD C Keywords : Injection MOCVD, Atmospheric Plasma, titanium oxide, anatase, PECVD Abstract TiO2 thin films combines remote Atmospheric Pressure (AP) Plasma with Pulsed Injection Metallorganic Chemical Vapour

Boyer, Edmond

19

Electronic structure and excitations in oxygen deficient CeO2?? from DFT calculations  

Science Journals Connector (OSTI)

The electronic structures of supercells of CeO2?? have been calculated within the density functional theory (DFT). The equilibrium properties such as lattice constants, bulk moduli, and magnetic moments are well reproduced by the generalized gradient approximation (GGA). Electronic excitations are simulated by robust total-energy calculations for constrained states with atomic core holes or valence holes. Pristine ceria CeO2 is found to be a nonmagnetic insulator with magnetism setting in as soon as oxygens are removed from the structure. In the ground state of defective ceria, the Ce-f majority band resides near the Fermi level but appears at about 2eV below the Fermi level in photoemission spectroscopy experiments due to final-state effects. We also tested our computational method by calculating threshold energies in Ce-M5 and O-K x-ray absorption spectroscopy and comparing theoretical predictions with the corresponding measurements. Our result that f electrons reside near the Fermi level in the ground state of oxygen-deficient ceria is crucial for understanding the catalytic properties of CeO2 and related materials.

T. Jarlborg; B. Barbiellini; C. Lane; Yung Jui Wang; R. S. Markiewicz; Zhi Liu; Zahid Hussain; A. Bansil

2014-04-01T23:59:59.000Z

20

Size-Dependent Oxygen Activation Efficiency over Pdn/TiO2(110) for the CO Oxidation Reaction  

Science Journals Connector (OSTI)

The dissociative binding efficiency of oxygen over Pdn/TiO2(110) (n = 4, 7, 10, 20) has been measured using temperature programmed reaction (TPR) mass spectrometry and X-ray photoemission spectroscopy (XPS) following exposure to O2 with varying doses and ...

William E. Kaden; William A. Kunkel; Matt D. Kane; F. Sloan Roberts; Scott L. Anderson

2010-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "atmospheric oxygen o2" 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

Acetone-Assisted Oxygen Vacancy Diffusion on TiO2(110)  

SciTech Connect

We have studied the dynamic relationship between acetone and bridge-bonded oxygen (Ob) vacancy (VO) defect sites on the TiO2(110)-1 1 surface using scanning tunneling microscopy (STM) and density function theory (DFT) calculations. We report an adsorbate-assisted VO diffusion mechanism. The STM images taken at 300 K show that acetone preferably adsorbs on the VO site and is mobile. The sequential isothermal STM images directly show that the mobile acetone effectively migrates the position of VO by a combination of two acetone diffusion channels: one is the diffusion along the Ob row and moving as an alkyl group, which heals the initial VO; another is the diffusion from the Ob row to the fivecoordinated Ti4+ row and then moving along the Ti4+ row as an acetone, which leaves a VO behind. The calculated acetone diffusion barriers for the two channels are comparable and agree with experimental results.

Xia, Yaobiao; Zhang, Bo; Ye, Jingyun; Ge, Qingfeng; Zhang, Zhenrong

2012-10-18T23:59:59.000Z

22

Atmospheric-Pressure Cold Plasma for Preparation of High Performance Pt/TiO2 Photocatalyst and Its Mechanism  

Science Journals Connector (OSTI)

Atmospheric-pressure dielectric barrier discharge (DBD) cold plasma was employed to fabricate Pt/TiO2 photocatalyst using the mixture of Ar and H2 as working gas. X-ray photoelectron microscopy (XPS) and transmis...

Lanbo Di; Xiuling Zhang; Zhijian Xu; Kai Wang

2014-03-01T23:59:59.000Z

23

Oxygen detected in atmosphere of Saturn's moon Dione  

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

Oxygen detected in atmosphere of Saturn's moon Dione Oxygen detected in atmosphere of Saturn's moon Dione Oxygen detected in atmosphere of Saturn's moon Dione Scientists and an international research team have announced discovery of molecular oxygen ions in the upper-most atmosphere of Dione. March 3, 2012 Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable energy sources, to plasma physics and new materials. Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable energy sources, to plasma physics and new materials.

24

Atmospheric Oxygen: Isotopic Composition and Solubility Fractionation  

Science Journals Connector (OSTI)

...where the subscripts aq and gas refer to the aqueous phase and the gas phase, respectively. The single-stage...adsorption and desorp-tion of oxygen gas on type SA molecular sieve...material seems to be debris of the Cyprus-sized planetesimal that produced...

P. Kroopnick; H. Craig

1972-01-07T23:59:59.000Z

25

Influence of oxygen in atmospheric-pressure argon plasma jet on sterilization of Bacillus atrophaeous spores  

Science Journals Connector (OSTI)

A nonequilibrium Ar ? O 2 plasmadischarge at atmospheric pressure was carried out in a coaxial cylindrical reactor with a stepped electrode configuration powered by a 13.56 MHz rf power supplier. The argon glow discharge with high electron density produces oxygen reactive species in large quantities. Argon plasma jets penetrate deep into ambient air and create a path for oxygen radicals to sterilize microbes. A sterilization experiment with bacterial endospores indicates that an argon-oxygen plasma jet very effectively kills endospores of Bacillus atrophaeus (ATCC 9372) thereby demonstrating its capability to clean surfaces and its usefulness for reinstating contaminated equipment as free from toxic biological warfare agents. The decimal reduction time ( D values) of the Ar ? O 2 plasma jet at an exposure distance of 0.5 1.5 cm ranges from 5 to 57 s . An actinometric comparison of the sterilization data shows that atomic oxygen radicals play a significant role in plasma sterilization. When observed under a scanning electron microscope the average size of the spores appears to be greatly reduced due to chemical reactions with the oxygen radicals.

Jin-Pyo Lim; Han S. Uhm; Shou-Zhe Li

2007-01-01T23:59:59.000Z

26

Temperature Dependent Absorption Cross-Sections of O2-O2 collision pairs1 between 340 and 630 nm and at atmospherically relevant pressure2  

E-Print Network (OSTI)

(CIA). At 203 K, van der Waals complexes (O2-dimer) contribute less than26 0.14% to the O4 absorption induced absorption (CIA) results in38 additional O4-CIA absorption from O2-O2 collision pairs that overlap that of O2-dimer. With CIA,39 the selection rules of molecular O2 transitions are relaxed as a result

27

Influence of oxygen traces on an atmospheric-pressure radio-frequency capacitive argon plasma discharge  

Science Journals Connector (OSTI)

An atmospheric-pressure capacitive discharge source driven by radio-frequency power supply at 13.56 MHz has been developed experimentally that is capable of producing a homogeneous and cold glow discharge in O2/Ar. With respect to the influence of oxygen component when diluted into argon plasmadischarge on the dischargecharacteristics the measurements of the electrical parameters (impedance phase angle resistance and reactance) are made systematically and the densities of the metastable and resonant state of argon are determined by means of optical emission spectroscopy(OES). It is shown that the admixture of oxygen into argon plasma not only changes the electric characteristics but also alters the optical emission spectra greatly due to strong interaction between the oxygen content and the argon in the plasma environment.

Shou-Zhe Li; Qi Wu; Wen Yan; Dezhen Wang; Han S. Uhm

2011-01-01T23:59:59.000Z

28

Morphology change of oxygen-restructured TiO2,,110... surfaces by UHV annealing: Formation of a low-temperature ,,12... structure  

E-Print Network (OSTI)

Morphology change of oxygen-restructured TiO2,,110... surfaces by UHV annealing: Formation of a low microscopy images of the strands are consistent with the added- Ti2O3-row model. UHV annealing of oxygen. Restructured surfaces are annealed in ul- trahigh vacuum UHV at temperatures between 620 and 830 K. The surface

Diebold, Ulrike

29

E-Print Network 3.0 - atmospheric pressure helium-oxygen Sample...  

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

Copyright permission to reproduce figures andor text from this article 12;Remote Atmospheric-Pressure... ) were treated with an atmospheric-pressure oxygen and...

30

Oxygen evolution reaction on IrO2-based DSA type electrodes: kinetics analysis of Tafel lines and EIS  

Science Journals Connector (OSTI)

The oxygen evolution reaction (OER) on IrO2Ta2O5 mixed oxide electrodes in H2SO4 solution was studied by performing quasi-stationary current-potential and electrochemical impedance spectroscopy (EIS) measurements. The uncompensated resistance corrected Tafel lines displayed two distinct linear regions, with one of the slope close to 60mVdec?1 in the low potential region and the other close to 130mVdec?1 in the high potential region. The kinetics equations based on the proposed OER mechanism were derived and were used to simulate the current-potential curve. A mathematical deduction of EIS data was also carried out based on one state-variable theory. Both the polarization curve and impedance spectra were well approximated by kinetics analysis.

Ji-Ming Hu; Jian-Qing Zhang; Chu-Nan Cao

2004-01-01T23:59:59.000Z

31

4, 28772914, 2007 Air-sea O2 flux  

E-Print Network (OSTI)

Variability in air-sea O2 and CO2 fluxes and its impact on atmospheric potential oxygen (APO 2 1 National Center for Atmospheric Research, Boulder, Colorado, USA 2 Dept. of Marine Chemistry-friendly Version Interactive Discussion EGU Abstract A three dimensional, time-evolving field of atmospheric

Paris-Sud XI, Université de

32

Plants, Weathering, and the Evolution of Atmospheric Carbon Dioxide and Oxygen  

SciTech Connect

Over the past six years we have published 24 papers that can be divided into three sections: (1) Study of plants and weathering, (2) modeling the evolution of atmospheric CO2 over Phanerozoic time (past 550 million years). (3) Modeling of atmospheric O2 over Phanerozoic time. References to papers published acknowledging this grant can be found at the end of this report and almost all are supplied in pdf form. (1) In the temperate forests of the Cascade Mountains, USA, calcium and magnesium meet vastly different fates beneath angiosperms vs gymnosperms. Calcium is leached beneath both groves of trees, but leached 20-40% more beneath the angiosperms. Magnesium is retained in the forest system beneath the angiosperms and leached from beneath the gymnosperms. (2) We have shown that climate and CO2, based on both carbon cycle modeling and hundreds of independent proxies for paleo-CO2, correlate very well over the past 550 million year. In a recent paper we use this correlation to deduce the sensitivity of global mean temperature to a doubling of atmospheric CO2, and results are in excellent agreement with the results of climatologists based on the historical record and on theoretical climate models (GCMs).(3) We have shown that concentrations of atmospheric oxygen, calculated by a combined carbon-sulfur cycle model, over the past 550 million years have varied with and influenced biological evolution.

Berner, Robert A

2008-02-05T23:59:59.000Z

33

\\{NOx\\} emission characteristics of fluidized bed combustion in atmospheres rich in oxygen and water vapor for high-nitrogen fuel  

Science Journals Connector (OSTI)

Abstract The present study examines the influence of water vapor in combustion atmosphere on \\{NOx\\} emission from oxygen-enriched combustion of air-dried distilled spirit lees and its char in a laboratory fluidized bed of 760mm high and 68mm in inner diameter. Steam was added into the fluidizing gas to vary the vapor content in the combustion atmosphere. At a combustion temperature of 950C and a steam-to-fuel mass ratio (S/F) of 0.5, the presence of water vapor reduced the \\{NOx\\} concentration in the flue gas for low O2 contents (?30vol.%) in the combustion agent but increased the \\{NOx\\} emission for high O2 contents (?40vol.%). The possible causes were clarified for this shift from suppression to promotion of fuel-N conversion into \\{NOx\\} with raising O2 concentration in the combustion agent. Varying temperature from 850C to 1150C resulted in a peak conversion of fuel-N to \\{NOx\\} in the temperature range of 9501050C for all the tested O2 concentrations. Increasing the O2 concentration tended to lower the critical temperature corresponding to such a peak fuel-N conversion. Testing results also suggested that the presence of excessive water vapor in the combustion atmosphere would inhibit the release of fuel-N in the devolatilization stage and promote the formation of some reducing gases. In addition to the anticipated diluting effect, the steam addition also shortened the reaction time for homogeneous and heterogeneous \\{NOx\\} reduction by the reducing gases and char. It is postulated that the formation of OH radicals at high O2 content and high temperature could cause the observed increase in the \\{NOx\\} emission.

Chuanqiang Zhu; Shuyuan Liu; Huan Liu; Juan Yang; Xiaoxing Liu; Guangwen Xu

2015-01-01T23:59:59.000Z

34

One-step fabrication of tetragonal ZrO2 particles by atmospheric pressure plasma jet  

Science Journals Connector (OSTI)

Abstract A novel atmospheric pressure plasma jet (APPJ) was applied to prepare the tetragonal zirconia particles via a solution of zirconyl (IV) nitrate hydrate (ZrO(NO3)2?xH2O) as the precursor. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The microstructure of zirconia was found to be an assembly of spherical particles with a tetragonal structure. The chemical composition of prepared zirconia particles was analyzed by XPS quantification study with an atomic ratio of O/Zr of 2.03 without nitrate residues. The results based on the one-particle-per-drop mechanism in an APPJ system also showed that the synthesis of tetragonal zirconia particles could be effectively achieved in one-step fabrication without the need for additional stabilizers or annealing process. Meanwhile, APPJ system has a great potential to be a cost-effective and time-saving process for particle production as compared to the wet chemical processes.

Yu-Ming Su; Yu-Lin Kuo; Chun-Ming Lin; Sun-Fen Lee

2014-01-01T23:59:59.000Z

35

Radio-frequency induction plasmas at atmospheric pressure: Mixtures of hydrogen, nitrogen, and oxygen with argon  

Science Journals Connector (OSTI)

Numerical calculations are reported which simulate atmospheric-pressure radiofrequency induction plasmas consisting of either pure argon or mixtures of argon with hydrogen, nitrogen, or oxygen. These calculati...

S. L. Girshick; W. Yu

1990-12-01T23:59:59.000Z

36

Characterization of CeO2-Supported Cu-Pd Bimetallic Catalyst for the Oxygen-Assisted Water-Gas Shift Reaction  

SciTech Connect

This study was focused to investigate the roles of Cu and Pd in CuPd/CeO2 bimetallic catalysts containing 20-30 wt% Cu and 0.5-1 wt% Pd used in the oxygen-assisted water-gas shift (OWGS) reaction employing a combined bulk and surface characterization techniques such as XRD, TPR, CO chemisorption, and in-situ XPS. The catalytic activity for CO conversion and the stability of catalyst during on-stream operation increased by the addition of Cu to Pd/CeO2 or Pd to Cu/CeO2 monometallic catalysts, especially when the OWGS reaction was performed under low temperatures, below 200oC. The bimetallic catalyst after leaching with nitric acid retained about 60% of its original activity. The TPR of monometallic Cu/CeO2 showed reduction of CuO supported on CeO2 in two distinct regions, around 150 and 250oC. The high temperature peak disappeared and reduction occurred in a single step around 150oC upon Pd addition. The Pd dispersion decreased from 38.5% for Pd/CeO2 to below 1% for CuPd/CeO2 bimetallic catalyst. In-situ XPS studies showed a shift in Cu 2p peaks toward lower binding energy (BE) with concommitant shift in the Pd 3d peaks toward higher BE. Addition of Pd decreased the surface Cu concentration while the concentration of Pd remained unaltered. All these observations indicated the formation of Cu-Pd surface alloy. The valence band XP spectra collected below 10 eV corroborated the core level XP spectra and indicated that Cu is mainly involved in the catalytic reaction. The improved catalytic activity and stability of CuPd/CeO2 bimetallic catalyst was attributed to the alloy formation.

Fox, Elise; Velu, Subramani; Engelhard, Mark H.; Chin, Ya-Huei; Miller, Jeffrey T.; Kropf, Jeremy; Song, Chunshan

2008-12-10T23:59:59.000Z

37

Low-temperature formation of Si O 2 layers using a two-step atmospheric pressure plasma-enhanced deposition-oxidation process  

Science Journals Connector (OSTI)

Silicon oxide ( Si O 2 ) layers were fabricated at low temperatures ( ? 400 C ) by combining the deposition of hydrogenated amorphous Si ( a - Si : H ) with its oxidation using atmospheric pressure plasmas excited by a 150 MHz very high-frequency (VHF) power. The surface excitation by the atmospheric pressure VHF plasma was capable of reducing the temperature for the hydrogen effusion from a - Si : H . As a result a porous a - Si : H film containing a large amount of hydrogen could be transformed into a stoichiometric Si O 2 with an approximately 24% increase in oxidation rate compared with the oxidation of Si(001) at a temperature of 400 C .

Hiroaki Kakiuchi; Hiromasa Ohmi; Makoto Harada; Heiji Watanabe; Kiyoshi Yasutake

2007-01-01T23:59:59.000Z

38

Movement of oxygen from the atmosphere to the mitochondria occurs via several convective and diffusive steps  

E-Print Network (OSTI)

4111 Movement of oxygen from the atmosphere to the mitochondria occurs via several convective and diffusive steps (Weibel et al., 1981). In mammals, maximal rate of oxygen consumption (VOmax) is not limited by any one step of the oxygen cascade; rather limitations to VOmax are distributed across all steps

Bennett, Albert F.

39

Characteristics of atmospheric-pressure non-thermal N2 and N2/O2 gas mixture plasma jet  

Science Journals Connector (OSTI)

An atmospheric-pressure non-thermal plasma jet driven by high frequency alternating current and operating on N2 and N2/O2 gas mixture is investigated. The plasma jet can reach 55?mm in length at a gas flow rate of 2500?l/h. The gas temperature at a distance of 4?mm from the nozzle is close to room temperature. Optical emission spectroscopy is employed to investigate the important plasma parameters such as the excited species rotational temperature vibrational temperature and excitation temperature under different discharge conditions. The results show that the plasma source operates under non-equilibrium conditions. The absolute irradiance intensity of the vibrational band N2(C-B) in the active region is measured. Taking into account the irradiance intensity of N2(C-B 0-0) and N2(B-X 0-0) as well as measured current the electron density which is determined by considering direct and step-wise electron impact excitation of nitrogen emission reaches a maximum value of 5.6??1020/m3.

Dezhi Xiao; Cheng Cheng; Jie Shen; Yan Lan; Hongbing Xie; Xingsheng Shu; Jiangang Li; Paul K. Chu

2014-01-01T23:59:59.000Z

40

Plasma-Assisted Synthesis of TiO2 Nanorods by Gliding Arc Discharge Processing at Atmospheric Pressure for Photocatalytic Applications  

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The present study explores a new method of synthesis of TiO2 nano-particles in an aqueous medium from TiCl3 precursor by non-thermal plasma in humid air as feeding gas obtained at atmospheric pressure. The precur...

E. Acayanka; A. Tiya Djowe; S. Laminsi

2013-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "atmospheric oxygen o2" 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

Isotopic tracer studies of oxygen transport through SiO2 films at 1000?C using secondary ion mass spectrometry  

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Dry oxides (?8 ppm H2O) grown on Si(100) at 1000?C at 1 atm using purified 1 6O2 and purified 1 8O2 were analyzed using secondary ion mass spectrometry.1 8O is observed at the interface in the bulk of the 1 6O oxide and at the surface in agreement with other recent reports. Our results show little lattice diffusion in agreement with Mikkelsens work [Appl. Phys. Lett. 4 5 1187 (1984)]. A previous report [J. Electrochem. Soc. 1 3 1 1944 (1984)] of appreciable lattice diffusion is due to higher water content.

C. J. Han; C. R. Helms

1986-01-01T23:59:59.000Z

42

Reductive atmosphere of supercritical water with RuO2 resulting in TcO2 colloid: Spectroscopic, morphological and crystallographic study on solutions and precipitates in Hastelloy C-22  

Science Journals Connector (OSTI)

In order to study the complicated behavior of technetium observed under various conditions of supercritical water (SCW), i.e. quantitative transfer to solid phase, strong adsorption onto the metal surface, or efficient dissolution from the metal surface, solutions and precipitates prepared in reactors made of Hastelloy C-22 in contact with the SCW containing technetium solutions were studied by absorption spectroscopy, TEM, EDX and electron diffraction. Under SCW with or without H2O2, NiCr2O4 and NiMoO4 was produced as the scales (corrosion products) of Hastelloy C-22. Under SCW with RuO2 the formation of colloidal structure comprised of ruthenium metal and TcO2, which may be named as Tc-Ru-Colloid, were observed. It is worthy of note that the formation of TcO42? from pertechnatate TcO4? (+0.596V) and the disproportionation of TcO42? is plausible at present in spite of the moderate reductive atmosphere (?0.533 to +0.114V) estimated from the observation (the existence of TcO2 and the absence of NiMoO4) by TEM and electron diffraction.

T. Yamamura; K. Yubuta; I. Satoh; Y. Yoshida; Y. Shiokawa; T. Sekine; W. Sugiyama; K.-C. Park; H. Tomiyasu

2007-01-01T23:59:59.000Z

43

Effect of specific surface area on oxygen storage capacity (OSC) and methane steam reforming reactivity of CeO2  

Science Journals Connector (OSTI)

It was found from the work that the specific surface area of ceria presents an important role on the oxygen storage capacity (OSC), the reactivity toward methane steam reforming, and the resistance toward carbon ...

W. Sutthisripok; S. Sattayanurak; L. Sikong

2008-10-01T23:59:59.000Z

44

E-Print Network 3.0 - atmospheric oxygen concentration Sample...  

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

< 1 2 3 4 5 > >> 1 Sulfur and oxygen isotope composition of the atmosphere in Saxony (Germany) Tichomirowa et al. Summary: Conclusions Mean SO2 concentrations in 2003 12;Sulfur...

45

Mycobacterium tuberculosis Lsr2 Is a Global Transcriptional Regulator Required for Adaptation to Changing Oxygen Levels and Virulence  

Science Journals Connector (OSTI)

...containing ambient atmospheric oxygen or in an...However, under atmospheric oxygen, the mutant...oxygen (A), under atmospheric oxygen (~18...were exposed to water, 5-mM H2O2...is critical for recovery from anaerobiosis...to indicate DNA condensation. If Lsr2 was involved...

I. L. Bartek; L. K. Woolhiser; A. D. Baughn; R. J. Basaraba; W. R. Jacobs; Jr.; A. J. Lenaerts; M. I. Voskuil

2014-06-01T23:59:59.000Z

46

Frequency effects on the production of reactive oxygen species in atmospheric radio frequency helium-oxygen discharges  

SciTech Connect

Several experimental and computational studies have shown that increasing frequency can effectively enhance the discharge stability in atmospheric radio-frequency (rf) discharges, but the frequency effects on the reactivity of rf discharges, represented by the densities of reactive oxygen species (ROS), are still far from fully understood. In this paper, a one-dimensional fluid model with 17 species and 65 reactions taken into account is used to explore the influences of the driving frequency on the production and destruction of ROS in atmospheric rf helium-oxygen discharges. From the computational results, with an increase in the frequency the densities of ROS decrease always at a constant power density, however, in the relatively higher frequency discharges the densities of ROS can be effectively improved by increasing the input power density with an expanded oxygen admixture range, while the discharges operate in the {alpha} mode, and the numerical data also show the optimal oxygen admixture for ground state atomic oxygen, at which the peak atomic oxygen density can be obtained, increases with the driving frequency.

Zhang, Yuantao T.; He Jin [Shandong Provincial Key Lab of UHV Technology and Gas Discharge Physics, School of Electrical Engineering, Shandong University, Jinan, Shandong Province 250061 (China)

2013-01-15T23:59:59.000Z

47

Discovery of oxygen in atmosphere could mean life for Saturn's moon Dione  

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

Discovery of oxygen in atmosphere could mean life for Saturn's Discovery of oxygen in atmosphere could mean life for Saturn's moon Dione Discovery of oxygen in atmosphere could mean life for Saturn's moon Dione Discovery could mean ingredients for life are abundant on icy space bodies. March 5, 2012 Curiosity rover bears three LANL technologies Inside Titan: This artist's concept shows a possible scenario for the internal structure of Titan, as suggested by data from NASA's Cassini spacecraft. Scientists have been trying to determine what is under Titan's organic-rich atmosphere and icy crust. Data from the radio science experiment make the strongest case yet for a global subsurface ocean, sitting above a subsurface layer of high-pressure ice and a water-infused silicate core. Image credit: A. Tavani Get Expertise

48

Removal of Xenon and Radon from Contaminated Atmospheres with Dioxygenyl Hexafluoroantimonate, O2SbF6  

Science Journals Connector (OSTI)

... process gas, and the excess fluorine must be removed afterwards. I have shown that radon, the heaviest noble gas, can be collected by oxidation with liquid bromine trifluoride and ... ). I report here further experiments with a dioxygenyl salt, O2SbF6, which reacts with radon and xenon at 25 C and which appears very promising as a reagent for removing ...

L. STEIN

1973-05-04T23:59:59.000Z

49

In situ Carbon 13 and Oxygen 18 Ratios of Atmospheric CO2 from Cape Grim,  

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

Oxygen Isotopes and Ratios » 13C and 18O Oxygen Isotopes and Ratios » 13C and 18O Ratios, Atmospheric CO2, Cape Grim In situ Carbon 13 and Oxygen 18 Ratios of Atmospheric CO2 from Cape Grim, Tasmania, Australia: 1982-1993 DOI: 10.3334/CDIAC/atg.db1014 data Data Investigators Francey R. J. and C. E. Allison Description Since 1982, a continuous program of sampling atmospheric CO2 to determine stable isotope ratios has been maintained at the Australian Baseline Air Pollution Station, Cape Grim, Tasmania (40°, 40'56"S, 144°, 41'18"E). The process of in situ extraction of CO2 from air, the preponderance of samples collected in conditions of strong wind from the marine boundary layer of the Southern Ocean, and the determination of all isotope ratios relative to a common high purity CO2 reference gas with isotopic δ13C close to

50

The O2/N2 Ratio Gas Solubility Mystery  

Science Journals Connector (OSTI)

Oxygen (O2) and nitrogen (N2) are the two most abundant gases in the Earths atmosphere and have generally similar physical properties, yet O2 is twice as soluble in water as N2, a feature that may have physiological and other biological consequences. ... In addition, a sensible explanation for the difference in the aqueous solubilities of O2 and N2 would provide some insight into the factors determining gas solubility in water. ... The soly. of 408 gaseous compds. in water at 298 K has been correlated through equation (i), where the soly. is expressed as the Ostwald soly. ...

Rubin Battino; Paul G. Seybold

2011-10-20T23:59:59.000Z

51

Detailed Atmosphere Modeling for the Neutron Star 1E1207.45209: Evidence of Oxygen/Neon Atmosphere  

Science Journals Connector (OSTI)

We present a comprehensive investigation of the two broad absorption features observed in the X-ray spectrum of the neutron star 1E1207.4-5209 based on a recent analysis of the 260 ks XMM-Newton data by Mori et al. Expanding on earlier work by Hailey & Mori, we have examined all previously proposed atmospheric models for 1E1207.4-5209. Using our atomic code, which rapidly solves Schrdinger's equation for arbitrary ions in strong magnetic field, we have systematically constructed atmospheric models by calculating polarization-dependent LTE opacities and addressed all the physics relevant to strongly magnetized plasmas. We have been able to rule out virtually all atmospheric models because they either do not sustain an ionization balance consistent with the claimed atmosphere composition or because they predict line strengths and line widths that are inconsistent with the data. Only oxygen or neon atmospheres at B ~ 1012 G provide self-consistent atmospheric solutions of the appropriate ionization balance that also have line widths, strengths, and energies consistent with the observations. The observed features are likely composed of several bound-bound transition lines from highly ionized oxygen/neon, and they are broadened primarily by motional Stark effects and magnetic field variation over the line-emitting region. Further considerations of plausible mechanisms for the formation of a mid-Z atmosphere likely rule out neon atmospheres and have important implications for the fallback mechanism in supernova ejecta. Future high-resolution spectroscopy missions such as Constellation-X will be able to resolve predicted substructure in the absorption features and will measure magnetic field strength and gravitational redshift independently to better than 10% accuracy.

Kaya Mori; Charles J. Hailey

2006-01-01T23:59:59.000Z

52

Using a High-Frequency Fluorescent Oxygen Probe in Atmospheric Eddy Covariance Applications  

Science Journals Connector (OSTI)

During the years 201013, atmospheric eddy covariance measurement of oxygen was performed at the marine site stergarnsholm in the Baltic Sea. The fast response optode Microx TX3 was used with two different types of tapered sensors. In spite of ...

Andreas Andersson; Anna Rutgersson; Erik Sahle

2014-11-01T23:59:59.000Z

53

Photoresist Trimming in Oxygen-Based High-Density Plasmas:? Effect of HBr and Cl2 Addition to CF4/O2 Mixtures  

Science Journals Connector (OSTI)

Cl2/CF4/O2c ... using NF3, CF4, SiF4, Cl2, HBr, and He/O2. ... Resist trimming in high-density CF4/O2 plasmas for sub-0.1 ?m device fabrication ...

Chian-Yuh Sin; Bing-Hung Chen; W. L. Loh; J. Yu; P. Yelehanka; A. See; L. Chan

2003-10-23T23:59:59.000Z

54

Small Au and Pt Clusters at the Anatase TiO2(101) Surface: Behavior at Terraces, Steps, and Surface Oxygen Vacancies  

E-Print Network (OSTI)

polymorph of titanium dioxide (TiO2). TiO2 is a versatile oxide material with important applications in many@ecust.edu.cn; diebold@tulane.edu Abstract: The adsorption properties of Au and Pt metal nanoclusters on TiO2 anatase edges. A preference for adsorption at type D-(112) steps is observed, which is probably a result

Diebold, Ulrike

55

Preparation of feedstocks from nano/submicron-sized TiO2 particles to obtain photocatalytic coatings by atmospheric plasma spraying  

Science Journals Connector (OSTI)

Abstract Atmospheric plasma spraying (APS) has been proved useful in obtaining TiO2 coatings with effective photocatalytic activity. However, the influence of feedstock characteristics on photocatalytic activity has hardly been addressed. This study was undertaken to prepare TiO2 photocatalytic coatings by APS from different feedstocks. The feedstocks were obtained by spray drying suspensions of a nano- and a submicron-sized TiO2 powder, with different solids contents and/or ratios of the nano- to submicron-sized particles. All the resulting powders were fully characterised to assess their suitability for use in APS processes. Feedstock powders were then deposited on steel coupons by APS using hydrogen or helium as secondary plasma gas. Coating microstructure and phase composition were characterised. Coating photocatalytic activity was determined by measuring the degradation of methylene blue dye in an aqueous solution. Powder characterisation showed that all feedstocks met plasma spray operation requirements with regard to agglomerate size distribution and density, as well as to powder flowability. Optimum agglomerate density was obtained when a well-balanced mixture of nano- and submicron-sized particles was used. All coatings displayed a bimodal microstructure with partially melted agglomerates that retained the initial nano- or submicron-sized structure and composition (anatase phase) of the feedstock, surrounded by a fully melted matrix mainly formed by rutile. As expected, coating porosity as well as the amount of partially melted areas depended strongly on plasma spray conditions and on feedstock characteristics. With regard to photocatalytic activity, a reasonably good fit of a first-order kinetic model to the experimental data was found for all coatings. The kinetic constants obtained displayed higher values than those of a commercial solgel coating. The values of these constants were related to feedstock characteristics as well as to plasma spraying conditions on the basis of anatase content. The contribution of other factors to the resulting coating surface is also discussed.

Mari Carmen Bordes; Mnica Vicent; Arnaldo Moreno; Vernica Lpez; Rodrigo Moreno; Mar;a Dolores Salvador; Rut Benavente; Enrique Snchez

2014-01-01T23:59:59.000Z

56

Atmospheric Pressure Humid Argon DBD Plasma for the Application of Sterilization -Measurement and Simulation of Hydrogen, Oxygen, and Hydrogen  

E-Print Network (OSTI)

Atmospheric Pressure Humid Argon DBD Plasma for the Application of Sterilization - Measurement, sterilization I. INTRODUCTION Non-thermal plasma technology at atmospheric pressure using oxygen of atmospheric pressure non-thermal argon plasma produced by a variety of techniques has recently begun

Paris-Sud XI, Université de

57

Atmospheric-pressure argon/oxygen plasma-discharge source with a stepped electrode  

SciTech Connect

The nonequilibrium glow discharge in argon mixed with oxygen at atmospheric pressure was generated in a parallel plate reactor with a stepped electrode powered by a 13.56 MHz radio-frequency power supplier. The stepped-electrode reactor consists of a narrow and wide gap structure. A strong electric field occurred at the narrow gap region preionizes Ar/O{sub 2} gas and assists to generate a large volumetric plasma in the wide gap region. Therefore, the stepped-electrode reactor makes it easy to operate Ar/O{sub 2} glow discharge, providing a stable, uniform, and broad plasma jet at atmospheric pressure.

Lim, Jin-Pyo; Uhm, Han S.; Li Shouzhe [Department of Molecular Science and Technology, Ajou University, San 5 Wonchon-Dong, Youngtong-Gu, Suwon 443-749 (Korea, Republic of); State Key Laboratory of Materials Modification by Laser, Ion and Electron Beams and Department of Physics, Dalian University of Technology, Dalian 116024 (China)

2007-01-29T23:59:59.000Z

58

Uranium in iron formations and the rise of atmospheric oxygen C.A. Partin a,  

E-Print Network (OSTI)

Uranium in iron formations and the rise of atmospheric oxygen C.A. Partin a, , S.V. Lalonde b , N.J. Planavsky c , A. Bekker a , O.J. Rouxel b,d , T.W. Lyons e , K.O. Konhauser f a Dept. of Geological Sciences), UMR 6538, Technopôle Brest-Iroise, 29280 Plouzané, France c Department of Geology and Geophysics, Yale

Konhauser, Kurt

59

Absolute atomic oxygen density profiles in the discharge core of a microscale atmospheric pressure plasma jet  

Science Journals Connector (OSTI)

The micro atmospheric pressure plasma jet is an rf driven (13.56 MHz ? 20 ? W ) capacitively coupled discharge producing a homogeneous plasma at ambient pressure when fed with a gas flow of helium (1.4 slm) containing small admixtures of oxygen ( ? 0.5 % ) . The design provides excellent optical access to the plasma core. Ground state atomic oxygen densities up to 3 10 16 ? cm ? 3 are measured spatially resolved in the discharge core by absolutely calibrated two-photon absorption laser-induced fluorescence spectroscopy. The atomic oxygen density builds up over the first 8 mm of the discharge channel before saturating at a maximum level. The absolute value increases linearly with applied power.

Nikolas Knake; Kari Niemi; Stephan Reuter; Volker Schulz-von der Gathen; Jrg Winter

2008-01-01T23:59:59.000Z

60

Influence of oxygen in atmospheric-pressure argon plasma jet on sterilization of Bacillus atrophaeous spores  

SciTech Connect

A nonequilibrium Ar/O{sub 2} plasma discharge at atmospheric pressure was carried out in a coaxial cylindrical reactor with a stepped electrode configuration powered by a 13.56 MHz rf power supplier. The argon glow discharge with high electron density produces oxygen reactive species in large quantities. Argon plasma jets penetrate deep into ambient air and create a path for oxygen radicals to sterilize microbes. A sterilization experiment with bacterial endospores indicates that an argon-oxygen plasma jet very effectively kills endospores of Bacillus atrophaeus (ATCC 9372), thereby demonstrating its capability to clean surfaces and its usefulness for reinstating contaminated equipment as free from toxic biological warfare agents. The decimal reduction time (D values) of the Ar/O{sub 2} plasma jet at an exposure distance of 0.5-1.5 cm ranges from 5 to 57 s. An actinometric comparison of the sterilization data shows that atomic oxygen radicals play a significant role in plasma sterilization. When observed under a scanning electron microscope, the average size of the spores appears to be greatly reduced due to chemical reactions with the oxygen radicals.

Lim, Jin-Pyo; Uhm, Han S.; Li, Shou-Zhe [Department of Molecular Science and Technology, Ajou University, San 5 Wonchon-Dong, Youngtong-Gu, Suwon 443-749 (Korea, Republic of); State Key Laboratory of Materials Modification by Laser, Ion and Electron Beams Department of Physics, Dalian University of Technology, Dalian 116024 (China)

2007-09-15T23:59:59.000Z

Note: This page contains sample records for the topic "atmospheric oxygen o2" 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

Fractal and Multifractal Analysis of the Rise of Oxygen in Earth's Early Atmosphere  

E-Print Network (OSTI)

The rise of oxygen in Earth's atmosphere that occurred 2.4 to 2.2 billion years ago is known as the Earth's Great Oxidation, and its impact on the development of life on Earth has been profound. Thereafter, the increase in Earth's oxygen level persisted, though at a more gradual pace. The proposed underlying mathematical models for these processes are based on physical parameters whose values are currently not well-established owing to uncertainties in geological and biological data. In this paper, a previously developed model of Earth's atmosphere is modified by adding different strengths of noise to account for the parameters' uncertainties. The effects of the noise on the time variations of oxygen, carbon and methane for the early Earth are investigated by using fractal and multifractal analysis. We show that the time variations following the Great Oxidation cannot properly be described by a single fractal dimension because they exhibit multifractal characteristics. The obtained results demonstrate that the time series as obtained exhibit multifractality caused by long-range time correlations.

Satish Kumar; Manfred Cuntz; Zdzislaw E. Musielak

2014-12-16T23:59:59.000Z

62

Chemical Constraints on the Water and Total Oxygen Abundances in the Deep Atmosphere of Saturn  

E-Print Network (OSTI)

Thermochemical equilibrium and kinetic calculations for the trace gases CO, PH3, and SiH4 give three independent constraints on the water and total oxygen abundances of Saturn's deep atmosphere. A lower limit to the water abundance of H2O/H2 > 1.7 x 10^-3 is given by CO chemistry while an upper limit of H2O/H2 < 5.5 x 10^-3 is given by PH3 chemistry. A combination of the CO and PH3 constraints indicates a water enrichment on Saturn of 1.9 to 6.1 times the solar system abundance (H2O/H2 = 8.96 x 10^-4). The total oxygen abundance must be at least 1.7 times the solar system abundance (O/H2 = 1.16 x 10^-3) in order for the SiH4 to remain below a detection limit of SiH4/H2 < 2 x 10^-10. A combination of the CO, PH3, and SiH4 constraints suggests that the total oxygen abundance on Saturn is 3.2 to 6.4 times the solar system abundance. Our results indicate that oxygen on Saturn is less enriched than other heavy elements (such as C and P) relative to a solar system composition. This work was supported by NASA NAG5-11958.

Channon Visscher; Bruce Fegley Jr

2005-01-07T23:59:59.000Z

63

Treatment of enterococcus faecalis bacteria by a helium atmospheric cold plasma brush with oxygen addition  

SciTech Connect

An atmospheric cold plasma brush suitable for large area and low-temperature plasma-based sterilization is designed. Results demonstrate that the He/O{sub 2} plasma more effectively kills Enterococcus faecalis than the pure He plasma. In addition, the sterilization efficiency values of the He/O{sub 2} plasma depend on the oxygen fraction in Helium gas. The atmospheric cold plasma brush using a proper ratio of He/O{sub 2} (2.5%) reaches the optimum sterilization efficiency. After plasma treatment, the cell structure and morphology changes can be observed by the scanning electron microscopy. Optical emission measurements indicate that reactive species such as O and OH play a significant role in the sterilization process.

Chen Wei; Huang Jun; Wang Xingquan; Lv Guohua; Zhang Guoping [Key Laboratory of Soft Matter Physics, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Science, 100190 Beijing (China); Du Ning; Liu Xiaodi; Guo Lihong [Department of Oral Biology, Peking University School and Hospital of Stomatology, 100080 Beijing (China); Yang Size [Key Laboratory of Soft Matter Physics, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Science, 100190 Beijing (China); Fujian Key Laboratory for Plasma and Magnetic Resonance, Department of Aeronautics, School of Physics and Mechanical and Electrical Engineering, Xiamen University, Xiamen 361005 (China)

2012-07-01T23:59:59.000Z

64

Nanoscale Phase Separation, Cation Ordering, and Surface Oxygen Chemistry in Pristine Li1.2Ni0.2Mn0.6O2 for Li-Ion Batteries  

SciTech Connect

Li-rich layered material Li1.2Ni0.2Mn0.6O2 possesses high voltage and high specific capacity, which makes it an attractive candidate for the transportation industry and sustainable energy storage systems. The rechargeable capacity of the Li-ion battery is linked largely to the structural stability of the cathode materials during the charge-discharge cycles. However, the structure and cation distribution in pristine (un-cycled) Li1.2Ni0.2Mn0.6O2 have not yet been fully characterized. Using a combination of aberration-corrected scanning/transmission electron microscopy, X-ray dispersive energy spectroscopy (XEDS), electron energy loss spectroscopy (EELS), and complementary multislice image simulation, we have probed the crystal structure, cation/anion distribution, and electronic structure of Li1.2Ni0.2Mn0.6O2 nanoparticle. We discovered that the electronic structure and valence state of transition metal ions show significant variations, which have been identified to be attributed to the oxygen deficiency near the particle surfaces. Characterization of the nanoscale phase separation and cation ordering in the pristine material are critical for understanding the capacity and voltage fading of this material for battery application.

Gu, Meng; Genc, Arda; Belharouak, Ilias; Wang, Dapeng; Amine, Khalil; Thevuthasan, Suntharampillai; Baer, Donald R.; Zhang, Jiguang; Browning, Nigel D.; Liu, Jun; Wang, Chong M.

2013-05-14T23:59:59.000Z

65

MnFe Oxides with Support of MgAl2O4, CeO2, ZrO2 and Y2O3ZrO2 for Chemical-Looping Combustion and Chemical-Looping with Oxygen Uncoupling  

Science Journals Connector (OSTI)

Department of Environmental Inorganic Chemistry, Chalmers University of Technology, S-412 96 Gteborg, Sweden ... Shen, L.; Wu, J.; Gao, Z.; Xiao, J.Reactivity deterioration of NiO/Al2O3 oxygen carrier for chemical looping combustion of coal in a 10 kWth reactor Combust. ...

Golnar Azimi; Henrik Leion; Tobias Mattisson; Magnus Rydn; Frans Snijkers; Anders Lyngfelt

2014-06-03T23:59:59.000Z

66

Role of metal components in Pd?Cu bimetallic catalysts supported on CeO2 for the oxygen-enhanced water gas shift  

SciTech Connect

Catalytic hydrogen production and CO removal in a post-reforming process are critical for low-temperature fuel cell applications. The present study aims at clarifying the role of metal components in bimetallic catalysts for oxygen-enhanced water gas shift (OWGS), wherein a small amount of O{sub 2} is added to H{sub 2}-rich reformate gas to enhance CO shift. Among CeO{sub 2}-supported bimetallic catalysts, Pd-Cu and Pt-Cu combinations were found to show strong synergetic promoting effect in OWGS, which leads to much higher CO conversion and higher H{sub 2} yield than WGS at low temperature around 250 C. Temperature programmed reduction (TPR) showed strong interaction between Pd and Cu in Pd-Cu/CeO{sub 2} by a single reduction peak in contrast to multiple peaks on monometallic Cu/CeO{sub 2}. Extended X-ray absorption fine structure (EXAFS) analysis revealed that such bimetallic Pd-Cu and Pt-Cu form alloy nanoparticles, where noble metal is mainly surrounded by Cu atoms. Oxygen storage capacity (OSC) measurements point to higher resistance of Pd-Cu to oxidation indicating that Pd keeps Cu in reduced state in air pulse condition. From kinetic study, Pd in Pd-Cu was found to promote CO shift, rather than CO oxidation by increasing the number of active sites and by suppressing H{sub 2} activation (that is inherent to monometallic Pd), which minimizes both the inhibition effect of H{sub 2} and the loss of H{sub 2} by oxidation in OWGS. Transient response technique revealed that Cu in Pd-Cu enhances desorption of strongly chemisorbed CO{sub 2} on catalyst surface in contrast to very slow CO{sub 2} desorption from surface of monometallic Pd. Thus, the excellent OWGS activity of Pd-Cu catalyst has been attributed to the complementary roles of the two metals for enhancing CO shift, which is realized by its alloy structure and the accompanying strong interaction between metal components.

Kugai, J.; Miller, J. T.; Guo, N.; Song, C. (Chemical Sciences and Engineering Division); ( PSC-USR); (Penn State Univ.)

2011-06-01T23:59:59.000Z

67

OH number densities and plasma jet behavior in atmospheric microwave plasma jets operating with different plasma gases (Ar, Ar/N2, and Ar/O2)  

Science Journals Connector (OSTI)

OH radical number density in multiple atmospheric pressure microwave plasma jets is measured using UV cavity ringdown ... 00) band at 308nm. The plasma cavity was excited by a 2.45GHz microwave plasma source a...

C. Wang; N. Srivastava

2010-12-01T23:59:59.000Z

68

Estimation of point of zero charge for activated carbon treated with atmospheric pressure non-thermal oxygen plasmas  

Science Journals Connector (OSTI)

Commercial activated carbon was treated with a non-thermal oxygen plasma under atmospheric pressure using three types of reactors: a dielectric barrier discharge (DBD) parallel-plate reactor; an atmospheric pressure glow discharge plasma jet reactor and a DBD coaxial type reactor. The samples treated with the plasma were characterized by the pH value at the point of zero charge. An estimation of the adsorption properties of samples for copper ions in aqueous solution was also carried out in order to explain the effect of pH value on the adsorption results.

Satoshi Kodama; Hidetoshi Sekiguchi

2006-01-01T23:59:59.000Z

69

Thermal Infrared Radiation and Carbon Dioxide in the Atmosphere  

E-Print Network (OSTI)

dioxide Water vapor #12;Atmospheric composition (parts per million by volume) · Nitrogen (N2) 780Thermal Infrared Radiation and Carbon Dioxide in the Atmosphere Bill Satzer 3M Company #12;Outline,840 · Oxygen (O2) 209,460 · Argon (Ar) 9340 · Carbon dioxide (CO2) 394 · Methane (CH4) 1.79 · Ozone (O3) 0

Olver, Peter

70

A dominant role of oxygen additive on cold atmospheric-pressure He + O{sub 2} plasmas  

SciTech Connect

We present in this paper how oxygen additive impacts on the cold atmospheric-pressure helium plasmas by means of a one-dimensional fluid model. For the oxygen concentration [O{sub 2}]?>??0.1%, the influence of oxygen on the electron characteristics and the power dissipation becomes important, e.g., the electron density, the electron temperature in sheath, the electron-coupling power, and the sheath width decreasing by 1.6 to 16 folds with a two-log increase in [O{sub 2}] from 0.1% to 10%. Also the discharge mode evolves from the ? mode to the ? mode. The reactive oxygen species are found to peak in the narrow range of [O{sub 2}]?=?0.4%0.9% in the plasmas, similar to their power-coupling values. This applies to their wall fluxes except for those of O* and O{sub 2}{sup ?}. These two species have very short lifetimes, thus only when generated in boundary layers within several micrometers next to the electrode can contribute to the fluxes. The dominant reactive oxygen species and the corresponding main reactions are schematically presented, and their relations are quantified for selected applications.

Yang, Aijun; Liu, Dingxin, E-mail: liudingxin@gmail.com, E-mail: xhw@mail.xjtu.edu.cn; Rong, Mingzhe; Wang, Xiaohua, E-mail: liudingxin@gmail.com, E-mail: xhw@mail.xjtu.edu.cn [Centre for Plasma Biomedicine, State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Xi'an 710049 (China); Kong, Michael G. [Centre for Plasma Biomedicine, State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Xi'an 710049 (China); Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, Virginia 23508 (United States); Department of Electrical and Computer Engineering, Old Dominion University, Norfolk, Virginia 23529 (United States)

2014-08-15T23:59:59.000Z

71

The Dust Explosion Characteristics of Coal Dust in an Oxygen Enriched Atmosphere  

Science Journals Connector (OSTI)

The ability to mix pulverised coal with oxygen at concentrations greater than the currently applied 21% may well provide advantages for burner design in oxy/coal fired systems. However the risk of dust explosions increases significantly with increasing oxygen concentration and temperature. In this study the influence of enriched oxygen concentrations is researched on the dust explosion characteristics of Indonesian (Sebuku) high volatile bituminous coal dust and on Pittsburgh Coal n8. Both ignition sensitivity characteristics (minimum ignition energy and minimum ignition temperatures) and explosion severity characteristics (maximum explosion pressure, Pmax, and maximum rate of pressure rise, Kst) are investigated.

Frederik Norman; Jan Berghmans; Filip Verplaetsen

2012-01-01T23:59:59.000Z

72

In Situ Studies of the Active Sites for the Water Gas Shift Reaction over Cu-CeO2 Catalysts: Complex Interaction Between Metallic Copper and Oxygen Vacancies of Ceria  

SciTech Connect

New information about the active sites for the water gas shift (WGS) reaction over Cu-CeO{sub 2} systems was obtained using in-situ, time-resolved X-ray diffraction (TR-XRD), X-ray absorption spectroscopy (TR-XAS, Cu K and Ce L3 edges), and infrared spectroscopy (DRIFTS). Cu-CeO{sub 2} nanoparticles prepared by a novel reversed microemulsion method (doped Ce1-xCuxO2 sample) and an impregnation method (impregnated CuO{sub x}/CeO{sub 2} sample) were studied. The results from all of the samples indicate that both metallic copper and oxygen vacancies in ceria were involved in the generation of active sites for the WGS reaction. Evidence was found for a synergistic Cu-O vacancy interaction. This interaction enhances the chemical activity of Cu, and the presence of Cu facilitates the formation of O vacancies in ceria under reaction conditions. Water dissociation occurred on the O vacancy sites or the Cu-O vacancy interface. No significant amounts of formate were formed on the catalysts during the WGS reaction. The presence of strongly bound carbonates is an important factor for the deactivation of the catalysts at high temperatures. This work identifies for the first time the active sites for the WGS reaction on Cu-CeO{sub 2} catalysts and illustrates the importance of in situ structural studies for heterogeneous catalytic reactions.

Wang,X.; Rodriguez, J.; Hanson, J.; Gamarra, D.; Martinez-Arias, A.; Fernandez-Garcia, M.

2006-01-01T23:59:59.000Z

73

A rapid and precise method for sampling and determining the oxygen isotope ratio of atmospheric  

E-Print Network (OSTI)

2002; Accepted 1 March 2002 A quantitative method for cryogenically sampling atmospheric water vapor recovery of a vaporized, known, 18 O water standard to 0.2% precision. Copyright # 2002 John Wiley & Sons differentially affect both the concentration and isotope ratio of atmospheric water vapor.5,8,9 Measurements

Ehleringer, Jim

74

Surface reactivity and oxygen migration in amorphous indium-gallium-zinc oxide films annealed in humid atmosphere  

SciTech Connect

An isotope tracer study, i.e., {sup 18}O/{sup 16}O exchange using {sup 18}O{sub 2} and H{sub 2}{sup 18}O, was performed to determine how post-deposition annealing (PDA) affected surface reactivity and oxygen diffusivity of amorphous indiumgalliumzinc oxide (a-IGZO) films. The oxygen tracer diffusivity was very high in the bulk even at low temperatures, e.g., 200?C, regardless of PDA and exchange conditions. In contrast, the isotope exchange rate, dominated by surface reactivity, was much lower for {sup 18}O{sub 2} than for H{sub 2}{sup 18}O. PDA in a humid atmosphere at 400?C further suppressed the reactivity of O{sub 2} at the a-IGZO film surface, which is attributable to OH-terminated surface formation.

Watanabe, Ken, E-mail: Watanabe.Ken@nims.go.jp [International Center for Young Scientists (ICYS-MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba 305-0044 (Japan)] [International Center for Young Scientists (ICYS-MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba 305-0044 (Japan); Lee, Dong-Hee [Optical and Electronic Materials Unit, NIMS, 1-1 Namiki, Tsukuba 305-0044 (Japan) [Optical and Electronic Materials Unit, NIMS, 1-1 Namiki, Tsukuba 305-0044 (Japan); Materials and Structures Laboratory (MSL), Tokyo Institute of Technology, Mailbox R3-4, 4259 Nagatsuta, Midori-ku, Yokohama 226-0026 (Japan); Sakaguchi, Isao; Haneda, Hajime [Optical and Electronic Materials Unit, NIMS, 1-1 Namiki, Tsukuba 305-0044 (Japan)] [Optical and Electronic Materials Unit, NIMS, 1-1 Namiki, Tsukuba 305-0044 (Japan); Nomura, Kenji [Frontier Research Center, Tokyo Institute of Technology, Mailbox S2-13, 4259 Nagatsuta, Midori-ku, Yokohama 226-0026 (Japan)] [Frontier Research Center, Tokyo Institute of Technology, Mailbox S2-13, 4259 Nagatsuta, Midori-ku, Yokohama 226-0026 (Japan); Kamiya, Toshio [Materials and Structures Laboratory (MSL), Tokyo Institute of Technology, Mailbox R3-4, 4259 Nagatsuta, Midori-ku, Yokohama 226-0026 (Japan) [Materials and Structures Laboratory (MSL), Tokyo Institute of Technology, Mailbox R3-4, 4259 Nagatsuta, Midori-ku, Yokohama 226-0026 (Japan); Materials Research Center for Element Strategy (MCES), Mailbox S2-13, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-0026 (Japan); Hosono, Hideo [Materials and Structures Laboratory (MSL), Tokyo Institute of Technology, Mailbox R3-4, 4259 Nagatsuta, Midori-ku, Yokohama 226-0026 (Japan) [Materials and Structures Laboratory (MSL), Tokyo Institute of Technology, Mailbox R3-4, 4259 Nagatsuta, Midori-ku, Yokohama 226-0026 (Japan); Frontier Research Center, Tokyo Institute of Technology, Mailbox S2-13, 4259 Nagatsuta, Midori-ku, Yokohama 226-0026 (Japan); Materials Research Center for Element Strategy (MCES), Mailbox S2-13, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-0026 (Japan); Ohashi, Naoki, E-mail: Ohashi.Naoki@nims.go.jp [Optical and Electronic Materials Unit, NIMS, 1-1 Namiki, Tsukuba 305-0044 (Japan) [Optical and Electronic Materials Unit, NIMS, 1-1 Namiki, Tsukuba 305-0044 (Japan); Materials Research Center for Element Strategy (MCES), Mailbox S2-13, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-0026 (Japan)

2013-11-11T23:59:59.000Z

75

Researchers Directly Observe Oxygen Signature in the Oxygen-evolving  

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

Researchers Directly Observe Oxygen Signature in the Researchers Directly Observe Oxygen Signature in the Oxygen-evolving Complex of Photosynthesis Arguably the most important chemical reaction on earth is the photosynthetic splitting of water to molecular oxygen by the Mn-containing oxygen-evolving complex (Mn-OEC) in the protein known as photosystem II (PSII). It is this reaction which has, over the course of some 3.8 billion years, gradually filled our atmosphere with O2 and consequently enabled and sustained the evolution of complex aerobic life. Coupled to the reduction of carbon dioxide, biological photosynthesis contributes foodstuffs for nutrition while recycling CO2 from the atmosphere and replacing it with O2. By utilizing sunlight to power these energy-requiring reactions, photosynthesis also serves as a model for addressing societal energy needs as we enter an era of diminishing fossil fuel resources and climate change. Understanding, at the molecular level, the dynamics and mechanisms behind photosynthesis is of fundamental importance and will prove critical to the future design of devices aimed at converting sunlight into electrochemical energy and transportable fuel.

76

Reaction Mechanism of Coal Chemical Looping Process for Syngas Production with CaSO4 Oxygen Carrier in the CO2 Atmosphere  

Science Journals Connector (OSTI)

Reaction Mechanism of Coal Chemical Looping Process for Syngas Production with CaSO4 Oxygen Carrier in the CO2 Atmosphere ... (5) One is to carry out first coal gasification and subsequently to introduce the syngas produced in the CLC system,(6) while the other is to feed the solid fuel directly to the fuel reactor in a CLC process. ... When oxygen supported by oxygen carrier is enough for converting the coal into CO2 and H2O, a considerable amount of heat will produce for electricity generation. ...

Yongzhuo Liu; Qingjie Guo; Yu Cheng; Ho-Jung Ryu

2012-07-13T23:59:59.000Z

77

Polymorphism in Amorphous SiO2  

Science Journals Connector (OSTI)

Brillouin scattering from a-SiO2 up to 17 GPa shows that an irreversible change in the longitudinal sound velocity takes place between 10 and 17 GPa and that this change is stable at atmospheric pressure. Raman spectra of the retrieved sample indicate that it is also amorphous but differ noticeably from that of the original sample.

M. Grimsditch

1984-06-25T23:59:59.000Z

78

The effect of oxygen concentration on the development of photosynthetic capacity by etiolated bean seedlings upon illumination  

Science Journals Connector (OSTI)

Summary The effects of oxygen concentration on 14CO2 uptake, the time required to compensation of respiration by photosynthesis and the greening of etiolated seedlings of bean upon illumination were investigated. It has been found that this factor had a large inhibitory action on the processes examined. In atmospheres of 1 and 21 % O2 the fixation of 14CO2 was observed after 3 hours of illumination, while in 100% O2 after 8 hours. The time required for compensation of respiration by photosynthesis was in order of 8 hours in 1% O2, 10 hours in 21 % O2 and 20 hours in 100 % O2 respectively. The chlorophyll a + b biosynthesis followed the similar pattern of inhibition by O2 as photosynthesis. The lag phase for the appearance of chlorophyll biosynthesis in 1 and 21 % O2 was 3 hours while in 100%O2 6 hours.

J. Poskuta; M. Mikulska; M. Faltynowicz; B. Bielak; B. Wrblewska

1974-01-01T23:59:59.000Z

79

Investigation of the Rechargeability of Li-O2 Batteries in Non-aqueous Electrolyte  

SciTech Connect

In order to understand the nature of the limited cycle life and poor energy efficiency associated with the secondary Li-O2 batteries the discharge products of primary Li-O2 cells at different depth of discharge (DOD) are systematically analyzed in this work. It is revealed that if discharged to 2.0 V a small amount of Li2O2 coexist with Li2CO3 and RO-(C=O)-OLi) in alkyl carbonate-based electrolyte. Further discharging the air electrodes to below 2.0 V the amount of Li2CO3 and LiRCO3 increases significantly due to the severe electrolyte decomposition. There is no Li2O detected in this alkyl carbonate electrolyte regardless of DOD. It is also found that the alkyl carbonate based electrolyte begins to decompose at 4.0 V during charging under the combined influences from the high surface area carbon, the nickel metal current collector and the oxygen atmosphere. Accordingly the impedance of the Li-O2 cell continues to increase after each discharge and recharge process indicating a repeated plating of insoluble lithium salts on the carbon surface. Therefore the whole carbon electrode becomes completely insulated only after a few cycles and loses the function of providing active tri-phase regions for the Li-oxygen batteries.

Xiao, Jie; Hu, Jian Z.; Wang, Deyu; Hu, Dehong; Xu, Wu; Graff, Gordon L.; Nie, Zimin; Liu, Jun; Zhang, Jiguang

2011-07-01T23:59:59.000Z

80

TiO2-assisted degradation of a perfluorinated surfactant in aqueous solutions treated by gliding arc discharge  

Science Journals Connector (OSTI)

The plasmachemical degradation of Forafac 1110, a perfluorinated non-ionic surfactant, in aqueous solutions was investigated using TiO2 catalysts. The considered plasma was the gliding arc in humid air, which results from an electric discharge at atmospheric pressure and quasi-ambient temperature. Two titanium dioxide powders were used and their synergistic effects on the Forafac degradation were compared. The results were discussed through the evolution of the pH, the conductivity, the fluoride ions concentration released in solutions, the surfactant concentration remaining after treatment and the chemical oxygen demand (COD) measurement. The combination of the plasmachemical treatment with heterogeneous catalysis through the use of TiO2 accelerated the Forafac degradation, since only 60min was sufficient to remove 96% instead of 360min needed in the absence of TiO2. The use of anatase and rutile under the trade-name of Rhodia TiO2 and Merck TiO2, respectively, led to different results, because Rhodia TiO2 has proven to be more efficient. It would seem that the crystalline phase as well as the crystallite size, explain the efficiency of anatase. The advantage of the plasma-catalysis is due to the fact that there is a significant production of the OH radicals not only generated by the gliding arc discharge but also by TiO2.

Kheira Marouf-Khelifa; Fatiha Abdelmalek; Amine Khelifa; Ahmed Addou

2008-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "atmospheric oxygen o2" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Comparison of on-line and off-line methods to quantify reactive oxygen species (ROS) in atmospheric aerosols  

E-Print Network (OSTI)

a wide range of inorganic and organic 72 compounds such as transition metals, hydrogen peroxide (H2O2), radicals (e.g., 73 OH??, O2???), and organic (hydro... Solutions of known H2O2 concentration (0.8 ml) were combined with DCFH (1 ml, 278 10 M, 20 % PBS) and HRP solution (0.2 ml, 5 unit ml-?1) in a disposable UV-?279 10 cuvette (Brand, semi-?micro, Sigma...

Fuller, S. J.; Wragg, F. P. H.; Nutter, J.; Kalberer, M.

2014-04-08T23:59:59.000Z

82

Imaging Oxygen Molecules Up Close | EMSL  

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

Imaging Oxygen Molecules Up Close Imaging Oxygen Molecules Up Close ARRA-enabled upgrades enhance research capabilities STM images of the same TiO2(110) area upon O2 chemisorption...

83

Effects of CeO2 Support Facets on VOx/CeO2 Catalysts in Oxidative...  

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

The higher activity for VOxCeO2(110) might be related to the more abundant oxygen vacancies present on the (110) facets, evidenced from Raman spectroscopic measurements....

84

Optical emission spectroscopic diagnostics of a non-thermal atmospheric pressure helium-oxygen plasma jet for biomedical applications  

Science Journals Connector (OSTI)

In this work we have applied optical emission spectroscopy diagnostics to investigate the characteristics of a non-thermal atmospheric pressure helium plasma jet. The discharge characteristics in the active and afterglow region of the plasma jet that are critical for biomedical applications have been investigated. The voltage-current characteristics of the plasma discharge were analyzed and the average plasma power was measured to be around 18?W. The effect of addition of small fractions of oxygen at 0.1%0.5% on the plasma jet characteristics was studied. The addition of oxygen resulted in a decrease in plasma plume length due to the electronegativity property of oxygen. Atomic and molecular lines of selected reactive plasma species that are considered to be useful to induce biochemical reactions such as OH transitions A 2 ? + ( ? = 0 1 ) ? X 2 ? ( ? ? = 0 ) at 308?nm and A 2 ? + ( ? = 0 1 ) ? X 2 ? ( ? ? = 1 ) at 287?nm O I transitions 3p5P?3s5S0 at 777.41?nm and 3p3P?3s3S0 at 844.6?nm N2(C-B) second positive system with electronic transition C 3 ? u ? ? B 3 ? g ? in the range of 300450?nm and N2 +(B-X) first negative system with electronic transition B 2 ? u + ? X 2 ? g + ( ? ? = 0 ) at 391.4?nm have been studied. The atomic emission lines of helium were identified including the He I transitions 3p3P0?2s3S at 388.8?nm 3p1P0? 2s1S at 501.6?nm 3d3D?2p3P0 at 587.6?nm 3d1D?2p1P0 at 667.8?nm 3s3S1?2p3P0 at 706.5?nm 3s1S0?2p1P0 at 728.1?nm and H? transition 2p-3d at 656.3?nm. Using a spectral fitting method the OH radicals at 306312?nm the rotational and vibrational temperatures equivalent to gas temperatures of the discharge was measured and the effective non-equilibrium nature of the plasma jet was demonstrated. Our results show that in the entire active plasma region the gas temperature remains at 310??25?K and 340??25?K and it increases to 320??25?K and 360??25?K in the afterglow region of the plasma jet for pure helium and helium/oxygen (0.1%) mixture respectively. Additionally the vibrational temperatures range from 2200??100?K and 2500??100?K for pure helium and helium/oxygen (0.1%) mixture respectively. The plasma jet was tested on heat sensitive polymer films used in biomedical applications such as polyethylene terephthalate and poly-L-lactide samples continuously for several minutes without causing any physical or thermal damage to the films. The plasma jet produces significant reactive species of interest while the gas temperatures remain very low demonstrating its potential for a range of biomedical applications.

2013-01-01T23:59:59.000Z

85

Imaging Intrinsic Diffusion of Bridge-Bonded Oxygen Vacancies...  

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

Intrinsic Diffusion of Bridge-Bonded Oxygen Vacancies on TiO2(110). Imaging Intrinsic Diffusion of Bridge-Bonded Oxygen Vacancies on TiO2(110). Abstract: Since oxygen atom...

86

Chemical Reactivity of Reduced TiO2(110): The dominant role of...  

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

Reactivity of Reduced TiO2(110): The dominant role of surface defects in oxygen chemisorption. Chemical Reactivity of Reduced TiO2(110): The dominant role of surface defects in...

87

Water as a Catalyst: Imaging Reactions of O-2 with Partially...  

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

with bridging hydroxyl groups, OHb, formed by H2O dissociation on bridging oxygen vacancies of TiO2 (110) are studied at low and high OHb coverages as a function of the O2...

88

Preparation of CuAlO2 and CuCrO2 thin films by solgel processing  

Science Journals Connector (OSTI)

CuAlO2 and CuCrO2 thin films were prepared by solgel processing and subsequent thermal treatment in air and inert gas atmosphere. Resistivities of 700? cm and 60? cm with optical transmissions of 65% and 32% were achieved respectively. The crystallization temperature of 700C allows the preparation of CuCrO2 on borosilicate glass. P-type conductivity was verified by Seebeck measurements and a transparent heterostructure including p-CuCrO2 showed rectifying behavior.

Stefan Gtzendrfer; Christina Polenzky; Stephan Ulrich; Peer Lbmann

2009-01-01T23:59:59.000Z

89

Rate-dependent morphology of Li2O2 growth in Li-O2 batteries  

E-Print Network (OSTI)

Compact solid discharge products enable energy storage devices with high gravimetric and volumetric energy densities, but solid deposits on active surfaces can disturb charge transport and induce mechanical stress. In this Letter we develop a nanoscale continuum model for the growth of Li2O2 crystals in lithium-oxygen batteries with organic electrolytes, based on a theory of electrochemical non-equilibrium thermodynamics originally applied to Li-ion batteries. As in the case of lithium insertion in phase-separating LiFePO4 nanoparticles, the theory predicts a transition from complex to uniform morphologies of Li2O2 with increasing current. Discrete particle growth at low discharge rates becomes suppressed at high rates, resulting in a film of electronically insulating Li2O2 that limits cell performance. We predict that the transition between these surface growth modes occurs at current densities close to the exchange current density of the cathode reaction, consistent with experimental observations.

Horstmann, B; Mitchell, R; Bessler, W G; Shao-Horn, Y; Bazant, M Z

2013-01-01T23:59:59.000Z

90

Keratinocyte and Hepatocyte Growth Proliferation and Adhesion to Helium and Helium/Oxygen Atmospheric Pressure Plasma Treated Polyethylene Terephthalate.  

E-Print Network (OSTI)

??To improve the surface properties of biomaterials, the effects of changes in surface chemistry and morphology of polyethylene terephthalate (PET) films treated with atmospheric pressure (more)

Christie, Megan Allison

2006-01-01T23:59:59.000Z

91

Artificial oxygen transport protein  

DOE Patents (OSTI)

This invention provides heme-containing peptides capable of binding molecular oxygen at room temperature. These compounds may be useful in the absorption of molecular oxygen from molecular oxygen-containing atmospheres. Also included in the invention are methods for treating an oxygen transport deficiency in a mammal.

Dutton, P. Leslie

2014-09-30T23:59:59.000Z

92

Optical and electrical characterization of the electron beam gun evaporated TiO2 lm  

E-Print Network (OSTI)

Optical and electrical characterization of the electron beam gun evaporated TiO2 ®lm V of TiO2 ®lms obtained by electron beam gun evaporation and annealed in an oxygen environment. A negative with TiO2 insulator ®lms deposited by electron beam gun evaporator. P-type Si wafers (1 0 0 orientation

Eisenstein, Gadi

93

Solid-State 55Mn NMR Spectroscopy of bis(?-oxo)dimanganese(IV) [Mn2O2(salpn)2], a Model for the Oxygen Evolving Complex in Photosystem II  

SciTech Connect

Given the obvious global energy needs, it has become imperative to develop a catalytic process for converting water to molecular oxygen and protons. Many have sought to understand the details of photosynthesis and in particular the water splitting reaction to help in the development of the appropriate catalysis.1-3 While the scientific community has made great strides towards this goal, it has fallen short at the critical stage of the determination of the structure associated with the oxygen evolving complex (OEC) within photosystem II (PSII).4,5 Despite the existence of x-ray structures of PSII,6-8 the best data we have for the structure of the OEC comes from models derived from EPR and EXAFS measurements.9-14 This experimental situation has led to collaborations with theoreticians to enable the development of models for the structure of the OEC where the experimental observables (EXAFS and magnetic resonance parameters) serve as constraints to the theoretical calculations. Of particular interest to this study is the observation of the S1 state of the Kok cycle15 where the core of the OEC can be described as a tetranuclear manganese cluster composed of Mn4OxCa. The simplest model for the OEC can be thought of as two Mn-pairs and a Ca2+ where each Mn-pair is antiferromagnetically coupled to its partner. We utilize the term "pair" to describe the Mn atoms within the OEC with the same oxidation state, which for the S1 state is (Mn2(III, III) and Mn2(IV, IV)).16 It is unclear as to the degree of interaction between the pairs as well as the role of the Ca2+. At cryogenic temperatures the S1 state of the OEC is diamagnetic and in principle amenable to solid-state NMR experiments.

Ellis, Paul D.; Sears, Jesse A.; Yang, Ping; Dupuis, Michel; Boron, Ted; Pecoraro, Vince; Stich, Troy; Britt, R. David; Lipton, Andrew S.

2010-12-01T23:59:59.000Z

94

Inhibitive Influence of Oxygen Vacancies for Photoactivity on...  

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

Inhibitive Influence of Oxygen Vacancies for Photoactivity on TiO2(110). Inhibitive Influence of Oxygen Vacancies for Photoactivity on TiO2(110). Abstract: Scanning tunneling...

95

Singlet oxygen luminescence detection with a fibre-coupled superconducting  

E-Print Network (OSTI)

Singlet oxygen luminescence detection with a fibre-coupled superconducting nanowire single Triplet State Singlet State 1O2 Ground State Oxygen 3O2 Singlet oxygen Free space singlet oxygen luminescence detection Fibre-based singlet oxygen luminescence detection References Superconducting Detector

Greenaway, Alan

96

Virtual Oxygen Sensor for Innovative NOx and PM Emission Control...  

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

Virtual Oxygen Sensor for Innovative NOx and PM Emission Control Technologies Virtual Oxygen Sensor for Innovative NOx and PM Emission Control Technologies A virtual O2 sensor for...

97

Influence of O2-induced surface roughening on the chemistry of water on TiO2(110)  

SciTech Connect

The impact of oxygen induced regrowth of TiO2 on the reduced rutile TiO2(110) surface has been studied using temperature programmed desorption (TPD) of adsorbed water multilayers. Pre-exposure of UHV annealed TiO2(110) surfaces to O2 at temperatures from 300 to 850 K induced changes in subsequent water TPDs that were interpreted in terms of the rougher surface morphologies resulting from the regrowth process. Water TPD from TiO2(110) previously oxidized at 300 K exhibited a new peak at *312 K due to reaction of water with O adatoms. These O adatoms were produced by dissociative adsorption of O2 at O-vacancy sites. Additionally, oxygen reacted (slowly) with surface Ti2O3 strands at RT. Water TPD from surfaces pre-oxidized at higher temperatures (P500 K) exhibited features reflective of desorption from rough surfaces, namely loss of peak resolution and eventual merger of the second layer and ice peaks, formation of a high temperature tail on the second layer peak, and broadening of the first layer TPD peak. The multiplicity of kinetically different adsorption sites on the roughened TiO2(110) surfaces contributed to the widening of the desorption features. Published by Elsevier B.V.

Zehr, Robert T.; Henderson, Michael A.

2008-04-15T23:59:59.000Z

98

Stability of polymer binders in Li-O2 batteries  

SciTech Connect

A number of polymers with various chemical structures were studied as binders for air electrodes in Li-O2 batteries. The nature of the polymer significantly affects the binding properties in the carbon electrodes thus altering the discharge performance of Li-O2 batteries. Stability of polymers to the aggressive reduced oxygen species generated during discharge was tested by ball milling them with KO2 and Li2O2, respectively. Most of the polymers decomposed under these conditions and mechanisms of the decompositions are proposed for some of the polymers. Polyethylene was found to have excellent stability and is suggested as robust binder for air electrodes in Li-O2 batteries.

Nasybulin, Eduard N.; Xu, Wu; Engelhard, Mark H.; Nie, Zimin; Li, Xiaohong S.; Zhang, Jiguang

2013-06-24T23:59:59.000Z

99

Low-Temperature Desorption of N2O from NO on Rutile TiO2(110...  

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

decreases rapidly as the initially clean, reduced TiO2(110) surface with 5% oxygen vacancies (VOs) becomes covered with oxygen adatoms and unreacted NO. The maximum...

100

Imaging Water Dissociation on TiO2(110): Evidence for Inequivalent...  

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

OH Groups. Abstract: Identical regions of partially reduced TiO2(110) surfaces with bridge-bonded oxygen vacancy (BBOV) concentrations of 10 % ML (1 ML 5.21014 cm-2)...

Note: This page contains sample records for the topic "atmospheric oxygen o2" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Quantifying the areal extent and dissolved oxygen concentrations of Archean oxygen oases.  

E-Print Network (OSTI)

??Several lines of evidence indicate that the advent of oxygenic photosynthesis preceded the oxygenation of the atmosphereperhaps by as much as 300 million years. The (more)

Olson, Stephanie

2013-01-01T23:59:59.000Z

102

Relationships between Fe redistribution and Po2 during mineral dissolution under low O2 conditions  

Science Journals Connector (OSTI)

Iron-bearing olivine was dissolved at different partial pressures of atmospheric oxygen (Po2) in a glove box to clarify the relationships between Fe redistribution and Po2 during mineral dissolution and to provide a deeper understanding of weathering under low oxygen conditions. The olivine was first dissolved at pH 4.56.0 and 1555C under the ambient air using a modified flow-through system. Some portion of Fe2+ released from olivine was oxidized and precipitated as Fe3+ oxides/hydroxides, and remained in the system, while the other portion flowed out of the system as Fe2+. Then, a kinetic model, considering mineral dissolution, water flow and Fe2+ oxidation rates, was made to estimate Fe behavior at different pHs, temperatures and dissolved O2 concentrations during dissolution. The kinetic model was applied to the experimental results under the ambient air; the validity of the model was confirmed by good agreement between the observed and calculated ? values where ? is a ratio of the amount of Fe3+ precipitated to the total amount of Fe2+ actually dissolved from olivine, an indicator of the oxidation state of a mineral dissolution system. Then, by using the kinetic model, we analyzed the results of the olivine dissolution experiments at 0.20 atm to 8.7נ105atm of Po2 and at constant pH and temperature. While the dissolution rates of olivine were not affected significantly by Po2, the olivine dissolution has indicated that ? decreases with decrease in Po2 and the ? variation at low Po2 cannot be explained by the classic rate law of Fe2+ oxidation. The calculations of ? based on the above kinetic model have revealed that the observed ? variation is well explained by the decrease in the power of [O2] (x) with decrease in [O2] for the Fe2+ oxidation rate, d[Fe2+]/dt=k[Fe2+][O2]x[OH]y (k: the rate constant, 0?x?1, and y?2); the x value decreased from 1.0 to 0.76 at 0.20 to 8.7נ105atm of Po2, respectively. The ??Po2 relationships imply that the ? value in a paleosol (fossil weathering profile) increases with increase in Po2 in the Paleoproterozoic.

Hirokazu Sugimori; Yoshiki Kanzaki; Takashi Murakami

2012-01-01T23:59:59.000Z

103

Sn and SnO2-graphene composites as anode materials for lithium-ion batteries  

Science Journals Connector (OSTI)

Sn and SnO2-graphene composites were synthesized using hydrothermal process, followed by annealing in Ar/H2 atmosphere, and characterized using x-ray diffraction, scanning electron microscopy, and transition elec...

Qi-Hui Wu; Chundong Wang; Jian-Guo Ren

2013-12-01T23:59:59.000Z

104

Alarming Oxygen Depletion Caused by Hydrogen Combustion and Fuel Cells and their Resolution by Magnegas$^{TM}$  

E-Print Network (OSTI)

We recall that hydrogen combustion does resolve the environmental problems of fossil fuels due to excessive emission of carcinogenic substances and carbon dioxide. However, hydrogen combustion implies the permanent removal from our atmosphere of directly usable oxygen, a serious environmental problem called oxygen depletion, since the combustion turns oxygen into water whose separation to restore the original oxygen is prohibitive due to cost. We then show that a conceivable global use of hydrogen in complete replacement of fossil fuels would imply the permanent removal from our atmosphere of 2.8875x10^7 metric tons O_2/day. Fuel cells are briefly discussed to point out similarly serious environmental problems, again, for large uses. We propose the possibility of resolving these problems by upgrading hydrogen to the new combustible fuel called magnegas^TM, whose chemical structure is composed by the new chemical species of magnecules, whose energy content and other features are beyond the descriptive capaciti...

Santilli, R M

2000-01-01T23:59:59.000Z

105

Large magnetoresistance in Si : B - Si O 2 - Al structures  

Science Journals Connector (OSTI)

A magnetic-field-dependent resistance change of eight orders of magnitude is observed in boron-doped Si - Si O 2 - Al structures. In order to identify the elementary mechanisms governing this phenomenon the thickness of the oxidic layer which is used as an interface energy barrier has been varied by changing the exposure time to an oxygen plasma. Next the chemical composition has been monitored by in situx-ray photoelectron spectroscopymeasurements. From current-voltage measurements we observe that at low temperatures an ultrathin Si O 2 layer provides the kinetic energy to trigger an autocatalytic process of impact ionization. A magnetic field suppresses the onset of impact ionization to higher electric fields resulting in a large magnetoresistance.

J. J. H. M. Schoonus; J. T. Kohlhepp; H. J. M. Swagten; B. Koopmans

2008-01-01T23:59:59.000Z

106

Etching polyimide with a nonequilibrium atmospheric-pressure plasma jet  

Science Journals Connector (OSTI)

An atmospheric-pressure plasma jet has been used to etch polyimide films at 1.08.00.2?? m/min at 760 Torr and between 50 and 250?C. The plasma was produced by flowing helium and oxygen between two concentric electrodes with the inner one coupled to 13.56 MHz rf power and the outer one grounded. The etch rate increased with the O 2 partial pressure the rf power and the substrate temperature. The apparent activation energy for etching was 0.16 eV. Langmuir-probe measurements revealed that the ion densities were between 110 10 and 110 11 ? cm ?3 5 mm from the end of the powered electrode. Biasing the substrate had no effect on the rate. Ozone singlet sigma metastable oxygen (b? 1 ? g + ) and singlet delta metastable oxygen (a? 1 ? g ) were detected in the plasma by emission spectroscopy. More ozone was produced in the effluent through the recombination of O atoms with O 2 . Based on the production rate of O 3 the concentration of O atoms 6 mm from the powered electrode was estimated to be ?710 14 ? cm ?3 at 6.6 Torr O 2 and 200 W power. It is proposed that O atoms are the principal reactive species involved in etching polyimide.

J. Y. Jeong; S. E. Babayan; A. Schtze; V. J. Tu; J. Park; I. Henins; G. S. Selwyn; R. F. Hicks

1999-01-01T23:59:59.000Z

107

Algae for Oxygen  

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Algae for Oxygen Algae for Oxygen Name: Pam Burkardt Status: N/A Age: N/A Location: N/A Country: N/A Date: N/A Question: Hi, I am Pam Burkardt, a seventh grader at Fox Chapel School. I have a question on algae. I read somewhere that someday people might take bath tubs full of algae onto spaceships to provide oxygen for the crew. How much oxygen does algae give off, is this really possible? Replies: I think that most of the oxygen in the atmosphere comes in fact from one-celled plants in the oceans, like algae. They are likely to produce a lot of oxygen per unit weight because they don't have non-photosynthesizing bark, roots, branches, etc., nor (I think) a major dormant period like temperate-zone plants. The cost of space travel at present is dominated by the expense of heaving weight up into Earth orbit (it costs very little extra to send it to the Moon, for example, or Mars). For missions of short duration the weight of the compressed oxygen you need to carry is less than the weight of algae, water and extra plumbing you'd need to carry if you relied on algae to produce your oxygen. The important use of green plants would be in very long duration space flight (years) or permanent inhabitation of worlds like the Moon, where you need an unlimited supply of oxygen. Now if you want to fantasize, Venus' atmosphere is almost all carbon dioxide. Suppose you dropped a whole lot of specially gene-tailored one-celled plants into the atmosphere (not the surface, it's too hot). Why then they might eat up all the carbon dioxide and produce a breathable atmosphere. The "greenhouse effect" would go away, and Venus would become a nice habitable if tropical world only 50 million miles away.

108

Anchoring Sites for Initial Au Nucleation on CeO2{111}: O Vacancy versus Ce Vacancy Changjun Zhang,  

E-Print Network (OSTI)

Anchoring Sites for Initial Au Nucleation on CeO2{111}: O Vacancy versus Ce Vacancy Changjun Zhang is a matter of debate. Both oxygen and cerium vacancies have been suggested as the anchoring sites initio thermodynamics approaches to investigate the formation of various vacancies at a CeO2{111} surface

Alavi, Ali

109

Silicon (100)/SiO2 by XPS  

SciTech Connect

Silicon (100) wafers are ubiquitous in microfabrication and, accordingly, their surface characteristics are important. Herein, we report the analysis of Si (100) via X-ray photoelectron spectroscopy (XPS) using monochromatic Al K radiation. Survey scans show that the material is primarily silicon and oxygen, and the Si 2p region shows two peaks that correspond to elemental silicon and silicon dioxide. Using these peaks the thickness of the native oxide (SiO2) was estimated using the equation of Strohmeier.1 The oxygen peak is symmetric. The material shows small amounts of carbon, fluorine, and nitrogen contamination. These silicon wafers are used as the base material for subsequent growth of templated carbon nanotubes.

Jensen, David S.; Kanyal, Supriya S.; Madaan, Nitesh; Vail, Michael A.; Dadson, Andrew; Engelhard, Mark H.; Linford, Matthew R.

2013-09-25T23:59:59.000Z

110

ARM - Evolution of the Atmosphere  

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provides clues as to the composition of the early atmosphere. Volcanic emissions include nitrogen, sulfur dioxide, carbon dioxide, and trace gases such as argon. Although oxygen,...

111

LEDLED portable oxygen gas sensor  

Science Journals Connector (OSTI)

A portable instrument for oxygen determination, based on the quenching of phosphorescent octaethylporphyrin by gaseous O2..., has been developed using the fluorimetric paired emitterdetector diode technique (FPE...

I. M. Perez de Vargas-Sansalvador; C. Fay

2012-12-01T23:59:59.000Z

112

The Mechanisms of Oxygen Reduction and Evolution Reactions in Nonaqueous Lithium-Oxygen Batteries  

SciTech Connect

The oxygen reduction/evolution reaction (ORR/OER) mechanisms in nonaqueous Li-O2 batteries have been investigated by using electron paramagnetic resonance spectroscopy in this work. We identified the superoxide radical anion (O2-) as an intermediate in the ORR process using 5,5-dimethyl-pyrroline N-oxide as a spin trap, while no O2- in OER was detected during the charge process. These findings provide insightful understanding on the fundamental oxygen reaction mechanisms in rechargeable nonaqueous Li-O2 batteries.

Cao, Ruiguo; Walter, Eric D.; Xu, Wu; Nasybulin, Eduard N.; Bhattacharya, Priyanka; Bowden, Mark E.; Engelhard, Mark H.; Zhang, Jiguang

2014-09-30T23:59:59.000Z

113

Attenuated degradation of a PEMFC cathode during fuel starvation by using carbon-supported IrO2  

Science Journals Connector (OSTI)

IrO2, a water electrolysis catalyst, has been known to be effective in preventing corrosion of the carbon support in proton exchange membrane fuel cells (PEMFCs). Particulate IrO2 can agglomerate easily, which can decrease substantially the catalytic surface area required for oxygen evolution reaction, causing the loss of catalytic efficiency. Furthermore, agglomerated IrO2 nanoparticles can have an adverse effect on the oxygen reduction reaction by covering the active surface area of the Pt/C cathode catalyst, which is a damaging factor for the intrinsic performance of PEMFC. Carbon-supported iridium oxide, IrO2/C, which can prevent the agglomeration of Ir nanoparticles more effectively, was synthesized to overcome these problems. Compared to the cell with the Pt/C cathode only, the cell with 10wt.% IrO2 particles and Pt/C cathode showed stronger durability during fuel starvation but the cell performance at normal operation decreased severely by 35%. The cell with the same amount of IrO2 dispersed on a carbon support, 10wt.% IrO2/C, showed similar durability during fuel starvation maintaining the cell performance comparable to the cell using a Pt/C cathode only. Carbon-supported IrO2, IrO2/C, was more effective than IrO2 particles in both maintaining the intrinsic performance and improving the cell durability during fuel starvation.

Injoon Jang; Imgon Hwang; Yongsug Tak

2013-01-01T23:59:59.000Z

114

Vibrational dynamics in isotopically substituted vitreous GeO2  

Science Journals Connector (OSTI)

We report the polarized Raman spectra of vitreous Ge O216, Ge O218, Ge70O2, and Ge74O2. This yields the O16?O18 and Ge70?Ge74 isotopic shifts for nearly all vibrational modes of the pure glassy material. The shifts of the broad high-frequency (infrared-active) modes are as predicted by a nearest-neighbor central-force ideal continuousrandom-network model. The shift of the broad dominant Raman line indicates a small but significant dependence on the Ge mass, and this suggests an effect of disorder not included in the central-force theory. The narrow "defect" line at 530 cm-1 appears to be all oxygen motion, and is tentatively identified with a regular ring of bonds. The narrow line at 345 cm-1 is unique in that it exhibits very little oxygen shift; it seems to consist largely of Ge motion, for which we have no firm explanation.

F. L. Galeener; A. E. Geissberger; G. W. Ogar; Jr.; R. E. Loehman

1983-10-15T23:59:59.000Z

115

O2 /O3 MICROATMOSPHERES IN THE SURFACE OF GANYMEDE R. E. JOHNSON AND W. A. JESSER  

E-Print Network (OSTI)

O2 /O3 MICROATMOSPHERES IN THE SURFACE OF GANYMEDE R. E. JOHNSON AND W. A. JESSER Engineering with the surfaces of the icy satellites (Johnson 1990). A manifestation of this interaction is the sputtered O2 atmosphere at Europa, pre- dicted in 1982 based on laboratory data (Johnson, Lanzerotti, & Brown 1982

Johnson, Robert E.

116

Unexpected Nondissociative Binding of N2O on Oxygen Vacancies...  

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Nondissociative Binding of N2O on Oxygen Vacancies on a Rutile TiO2(110)-11 . Unexpected Nondissociative Binding of N2O on Oxygen Vacancies on a Rutile TiO2(110)-11 ....

117

Intrasphere and extrasphere effects of the influence of ammine complexes of transition metals on their catalytic activity in reactions of oxidation of manganese sulfate to the dioxide by atmospheric oxygen  

SciTech Connect

Manganese(II) sulfate is a waste product from the large-tonnage redox process for production of anthraquinone from aniline. Recovery of the original manganese dioxide and removal of manganese(II) sulfate from the wastewaters are economically and ecologically necessary. Liquid-phase low-temperature conversion of manganese(II) sulfate by the action of atmospheric oxygen blown through an aqueous solution of the salt containing ammine complexes of transition metals was studied earlier. It was shown that it does not depend only on intrasphere cations or extrasphere anions; it may be influenced by the effects of their interactions. The purpose of the present work was to study this influence in a complete factorial experiment of the CFE-3T type. It was found that homogeneous catalysis of oxidation of manganese(II) sulfate by atmospheric oxygen in presence of transition-metal ammines is determined to a considerable extent by the effects of pair interactions between complex-forming cations and extrasphere anions.

Eremeev, A.P.; Veselovskii, P.F.

1986-12-10T23:59:59.000Z

118

Physisorption of N2, O2, and CO on Fully Oxidized TiO2(110)  

SciTech Connect

Physisorption of N2, O2 and CO was studied on fully oxidized TiO2(110) using beam reflection and temperature programmed desorption (TPD) techniques. Sticking coefficients for all three molecules are nearly equal (0.75 0.05) and approximately independent of coverage suggesting that adsorption occurs via a precursor mediated mechanism. Excluding multilayer coverages, the TPD spectra for all three adsorbates exhibit three distinct coverage regimes that can be interpreted in accord with previous theoretical studies of N2 adsorption. At low coverages (0 to 0.5 N2/Ti4+), N2 molecules bind head-on to five-coordinated Ti4+ ions. The adsorption occurs preferentially on the Ti4+ sites that do not have neighboring adsorbates. This arrangement minimizes the repulsive interactions between the adsorbed molecules along the Ti4+ rows resulting in a relatively small shift of the TPD peak (105 ? 90 K) with increasing coverage. At higher N2 coverages (0 to 1.0 N2/Ti4+) the nearest-neighbor Ti4+ sites become occupied. The close proximity of the adsorbates results in strong repulsion thus giving rise to a significant shift of the TPD leading edges (90 ? 45 K) with increasing coverage. For N2/Ti4+ > 1, an additional low temperature peak (~ 43 K) is present and is ascribed to N2 adsorption on bridge-bonded oxygen rows. The results for O2 and CO are qualitatively similar. The repulsive adsorbate-adsorbate interactions largest for CO, most likely due to aligned CO dipole moments. The coverage dependent binding energies of O2, N2, and CO are determined by inverting TPD profiles.

Dohnalek, Zdenek; Kim, Jooho; Bondarchuk, Oleksander A.; White, J. M.; Kay, Bruce D.

2006-03-30T23:59:59.000Z

119

Photocatalytic Synthesis of TiO2 and Reduced Graphene Oxide Nanocomposite for Lithium Ion Battery  

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In this work, we synthesized graphene oxide (GO) using the improved Hummers oxidation method. TiO2 nanoparticles can be anchored on the GO sheets via the abundant oxygen-containing functional groups such as epoxy, hydroxyl, carbonyl, and carboxyl groups ...

Jingxia Qiu; Peng Zhang; Min Ling; Sheng Li; Porun Liu; Huijun Zhao; Shanqing Zhang

2012-06-27T23:59:59.000Z

120

Investigation on the Charging Process of Li2O2-Based Air Electrodes in Li-O2 Batteries with Organic Carbonate Electrolytes  

SciTech Connect

The charge processes of Li-O2 batteries were investigated by analyzing the gas evolution by in situ gas chromatography-mass spectroscopy (GC/MS) technique. The mixture of Li2O2/Fe3O4/Super P carbon/polyvinylidene fluoride (PVDF) was used as the starting air electrode material and 1M LiTFSI in carbonate-based solvents was used as electrolyte. It was found that Li2O2 is reactive to 1-methyl-2-pyrrolidinone and PVDF binder used in the electrode preparation. During the 1st charge (up to 4.6 V), O2 was the main component in the gases released. The amount of O2 measured by GC/MS was consistent with the amount of Li2O2 decomposed in the electrochemical process as measured by the charge capacity, indicative of the good chargeability of Li2O2. However, after the cell was discharged to 2.0 V in O2 atmosphere and re-charged to ~ 4.6 V in the second cycle, CO2 was dominant in the released gases. Further analysis of the discharged air electrode by X-ray diffraction and Fourier transform infrared spectroscopy indicated that lithium-containing carbonate species (lithium alkyl carbonate and/or Li2CO3) were the main reaction products. Therefore, compatible electrolyte and electrodes as well as the electrode preparation procedures need to be developed for long term operation of rechargeable Li-O2 or Li-air batteries.

Xu, Wu; Viswanathan, Vilayanur V.; Wang, Deyu; Towne, Silas A.; Xiao, Jie; Nie, Zimin; Hu, Dehong; Zhang, Jiguang

2011-04-15T23:59:59.000Z

Note: This page contains sample records for the topic "atmospheric oxygen o2" 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

Atomic Structure of the Anatase TiO2(001) Surface  

SciTech Connect

Understanding the structure of well-defined anatase TiO2 surfaces is critical for deciphering site-specific thermal and photo- reaction mechanisms on anatase TiO2. Using UHV scanning tunneling microscopy (STM), we have studied the atomic structure of anatase TiO2(001) epitaxial thin films grown by oxygen plasma assisted molecular beam epitaxy. Bright rows of the (14) reconstructed surface are resolved as three types of features with different sizes. High-resolution STM images taken from the same area at different bias voltages show that these individual features are originated from combinations of two basic atomic building blocks. We propose a modified added molecule model for the anatase TiO2 (001) surface structure.

Xia, Yaobiao; Zhu, Ke; Kaspar, Tiffany C.; Du, Yingge; Birmingham, Blake; Park, Kenneth T.; Zhang, Zhenrong

2013-08-16T23:59:59.000Z

122

Induction of Cytotoxicity by Photoexcited TiO2 Particles  

Science Journals Connector (OSTI)

...TiO2 in the suspension was measured with combustion analysis. The TiO2 aqueous suspension...photoexcited TiO2 particles. it did not produce heat at the irradiated site. Since TiO2 alone...Heterogeneous photocatalytic oxidation of hydrocarbons on platinized TiO2 powders. J. Phys...

Ruxiong Cai; Yoshinobu Kubota; Taro Shuin; Hideki Sakai; Kazuhito Hashimoto; and Akira Fujishima

1992-04-15T23:59:59.000Z

123

Alarming Oxygen Depletion Caused by Hydrogen Combustion and Fuel Cells and their Resolution by Magnegas$^{TM}$  

E-Print Network (OSTI)

We recall that hydrogen combustion does resolve the environmental problems of fossil fuels due to excessive emission of carcinogenic substances and carbon dioxide. However, hydrogen combustion implies the permanent removal from our atmosphere of directly usable oxygen, a serious environmental problem called oxygen depletion, since the combustion turns oxygen into water whose separation to restore the original oxygen is prohibitive due to cost. We then show that a conceivable global use of hydrogen in complete replacement of fossil fuels would imply the permanent removal from our atmosphere of 2.8875x10^7 metric tons O_2/day. Fuel cells are briefly discussed to point out similarly serious environmental problems, again, for large uses. We propose the possibility of resolving these problems by upgrading hydrogen to the new combustible fuel called magnegas^TM, whose chemical structure is composed by the new chemical species of magnecules, whose energy content and other features are beyond the descriptive capacities of quantum chemistry. In fact, magnegas contains up to 50% hydrogen, while having combustion exhaust with: 1) a positive oxygen balance (releasing more oxygen in the exhaust than that used in the combustion); 2) no appreciable carcinogenic or toxic substances; 3) considerably reduced carbon dioxide as compared to fossil fuels; 4) considerably reduced nitrogen oxides; and 5) general reduction of pollutants in the exhaust up to 96% of current EPA standards.

R. M. Santilli

2000-09-04T23:59:59.000Z

124

Thermochemical treatments based on NH3/O2 for improved graphite-based fiber electrodes in vanadium redox flow batteries  

Science Journals Connector (OSTI)

Abstract Electrochemical behavior of the polyacrylonitrile (PAN)-based graphite as a low cost electrode material for vanadium based redox batteries (VFB) in sulfuric acid medium has been improved by means of the successful introduction of nitrogen and oxygen-containing groups at the graphite surface by thermal activation under NH3/O2 (1:1) atmosphere. Influence of the temperature and treatment duration times have been studied towards the positive reaction of VFB. The structure, composition, and electrochemical properties of the treated samples have been characterized with field emission scanning electron microscopy, X-ray photoelectron spectroscopy, cyclic voltammetry and electrochemical impedance spectroscopy. The estimation of electrochemical surface area has also been evaluated. The treatment of PAN graphite material at 773K for 24-h leads to electrode materials with the best electrochemical activity towards the VO 2 + /VO2+ redox couple. This method produces an increase of the nitrogen and oxygen content at the surface up to 8% and 32%, respectively, and is proved to be a straightforward and cost-effective methodology. This improvement of the electrochemical properties is attributed to the incorporation of the nitrogen and oxygen-containing groups that facilitate the electron transfer through the electrode/electrolyte interface for both oxidation and reduction processes.

Cristina Flox; Javier Rubio-Garca; Marcel Skoumal; Teresa Andreu; Juan Ramn Morante

2013-01-01T23:59:59.000Z

125

Plants and Night Oxygen Production  

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Plants and Night Oxygen Production Plants and Night Oxygen Production Name: Ashar Status: other Grade: other Location: Outside U.S. Country: India Date: Winter 2011-2012 Question: I would like to know if there are any plants which produces oxygen at night (without photosynthesis). I was told by a friend that Holy Basil (Ocimum tenuiflorum) produces oxygen even at night and I'm not convinced. I would like to get confirmation from experts. Replies: Some plants (particularly those of dry regions, e.g., deserts) only open their stomates at night to avoid drying out to intake CO2 (and output O2) (CAM photosynthesis) http://en.wikipedia.org/wiki/Crassulacean_acid_metabolism Sincerely, Anthony R. Brach, PhD Missouri Botanical Garden Bringing oxygen producing plants into your home is a way to mimic the healthy lifestyle factors of longevity in humans from the longest lived cultures.

126

Off-normal CO2 desorption from the photooxidation of CO on reduced TiO2(110)  

SciTech Connect

Photo-induced reactions between O2 and CO on reduced rutile TiO2(110) are studied at low temperature (~30K). Photon stimulated desorption (PSD) of O2, CO2 and CO are observed with comparable yields. Isotope labeling experiments indicate that O2 chemisorbed in a vacancy is more active for photooxidation than O2 chemisorbed on a Ti5c site. The angular distribution for the desorbing CO2 is peaked at ~40 with respect to the surface normal in the azimuth (i.e. perpendicular to the bridging oxygen rows) suggesting that CO2 is produced from O2 occupying an oxygen vacancy and CO adsorbed on a Ti5c site next to it. The experimental results are consistent with CO2 being produced from a transition state complex that has been predicted theoretically. The CO PSD from TiO2(110) is enhanced dramatically by the presence of chemisorbed O2 suggesting that it is a by-product of the CO photooxidation process.

Petrik, Nikolay G.; Kimmel, Gregory A.

2010-09-02T23:59:59.000Z

127

8, 22252248, 2008 Detection of oxygen  

E-Print Network (OSTI)

ACPD 8, 2225­2248, 2008 Detection of oxygen emission related to spring bloom H. Yamagishi et al Chemistry and Physics Discussions Detection of regional scale sea-to-air oxygen emission related to spring bloom near Japan by using in-situ measurements of atmospheric oxygen/nitrogen ratio H. Yamagishi 1 , Y

Paris-Sud XI, Université de

128

Fiber-optic oxygen sensor using molybdenum chloride cluster luminescence  

E-Print Network (OSTI)

Fiber-optic oxygen sensor using molybdenum chloride cluster luminescence Ruby N. Ghosh,a) Gregory L on a reflection-mode fiber-optic oxygen sensor based on the 3 O2 quenching of the red emission from hexanuclear molybdenum chloride clusters. Measurements of the probe operating in a 0%­21% gaseous oxygen environment have

Ghosh, Ruby N.

129

SiO2 aerogel ultra low k dielectric patterning using different hard mask concepts and stripping processes  

Science Journals Connector (OSTI)

The patterning of porous SiO"2 aerogel as ultra low k dielectric has been investigated. Three different concepts were examined to etch this material without damage and to finally integrate it into a copper damascene metallization. Oxygen containing etching ... Keywords: Dielectric thin films, H2/N2 strip, Integrated circuit interconnections, Low dielectric constant, Plasma etching, Porous materials, SiO2 aerogel

F. Blaschta; K. Schulze; S. E. Schulz; T. Gessner

2004-10-01T23:59:59.000Z

130

CO Oxidation on Aun/TiO2 Catalysts Produced by Size-Selected Cluster Sungsik Lee, Chaoyang Fan, Tianpin Wu, and Scott L. Anderson*  

E-Print Network (OSTI)

. Indeed, Fu et al.2 recently showed that activity for the water gas shift reaction on Au/CeO2 and Pt/CeO2 TiO2 in an ultrahigh vacuum (UHV-base pressure 1 ? 10-10 mbar). The kinetic energy spread of the Aun-8% of oxygen vacancies. (The XPS vacancy estimate was calibrated by a separate water dissociation experiment

Anderson, Scott L.

131

Matching O2 Delivery to O2 Demand in Muscle: II. Allometric Variation in Energy Demand  

Science Journals Connector (OSTI)

This paper and the preceding paper by Weibel and Kayar address the question of whether, or to what extent, the structures involved in O2 consumption and delivery are matched to each other. This match between stru...

C. Richard Taylor; Kim E. Longworth

1988-01-01T23:59:59.000Z

132

ETEM observation of Pt/C electrode catalysts in a moisturized cathode atmosphere  

Science Journals Connector (OSTI)

There have been reports of challenges in designing platinum carbon (Pt/C) electrode catalysts for PEMFC. Pt/C electrode catalysts deactivate much faster on the cathode (in moisturized O2) than on the anode (in H2). To understand influences of moisture and oxygen on the deactivation of the Pt/C catalysts in proton-exchange-membrane fuel cells (PEMFCs), spherical-aberration-corrected environmental transmission electron microscopy (AC-ETEM) was applied with a high-speed CCD camera. Structural changes of the Pt/C electrode catalysts were dynamically recorded in moisturized nitrogen, oxygen and hydrogen. The mass spectrometry confirmed the moisture content (between 5 to 30 %) of nitrogen driving gas through a humidifier. Coalescence of platinum nanoparticles (D = 3.24 nm) was carefully evaluated in pure N2 and moisturized N2 atmosphere. The Pt/C showed considerable structural weakness in a moisturized N2 atmosphere. Comparable results obtained by AC-ETEM in different gas atmospheres also suggested ways to improve the oxygen reduction reaction (ORR). In this paper, the deactivation process due to moisture (hydroxylation) of carbon supports is discussed using for comparison the movement of platinum nanoparticles measured in moisturized nitrogen and pure nitrogen atmospheres.

K Yoshida; X Zhang; N Tanaka; E D Boyes; P L Gai

2014-01-01T23:59:59.000Z

133

High temperature properties of Ce1-xPrxO2-? as an active layer material for SOFC cathodes  

Science Journals Connector (OSTI)

We prepared Ce1-xPrxO2-? and investigated its high temperature properties as a material for the composite active layer of a solid oxide fuel cell (SOFC) cathode. We found that increasing the Pr concentration increases the total conductivity and oxygen vacancy concentration at high temperature, and this may lead to improvement of the cathodic reaction. When Ce1-xPrxO2-? is heated, it expands significantly at a certain temperature (Tinf), and this expansion depends on the Ce1-xPrxO2-? composition. The expansion is associated with an abrupt increase in the unit cell volume of the cubic structure. Abrupt increases in the total conductivity and oxygen vacancy concentration were also observed at Tinf. These results can be explained by oxygen vacancy and electron formation (n-type electronic conductivity increase) at Tinf and above Tinf. A sample with a Ce1-xPrxO2-? composition where x=1.0 has no such Tinf. A composition near x=1.0 for Ce1-xPrxO2-? is favorable for the active layer material of an SOFC cathode, because of the high conductivity and high concentration of oxygen vacancies.

Reiichi Chiba; Hiroaki Taguchi; Takeshi Komatsu; Himeko Orui; Kazuhiko Nozawa; Hajime Arai

2011-01-01T23:59:59.000Z

134

High Density n-Si/n-TiO2 Core/Shell Nanowire Arrays with Enhanced Photoactivity  

SciTech Connect

There are currently great needs to develop low-cost inorganic materials that can efficiently perform solar water splitting as photoelectrolysis of water into hydrogen and oxygen has significant potential to provide clean energy. We investigate the Si/TiO2 nanowire heterostructures to determine their potential for the photooxidation of water. We observed that highly dense Si/TiO2 core/shell nanowire arrays enhanced the photocurrent by 2.5 times compared to planar Si/TiO2 structure due to their low reflectance and high surface area. We also showed that n-Si/n-TiO2 nanowire arrays exhibited a larger photocurrent and open circuit voltage than p-Si/n-TiO2 nanowires due to a barrier at the heterojunction.

Hwang, Yun Jeong; Boukai, Akram; Yang, Peidong

2008-11-15T23:59:59.000Z

135

Dissociative electron attachment and electron-impact resonant dissociation of vibrationally excited O2 molecules  

E-Print Network (OSTI)

State-by-state cross sections for dissociative electron attachment and electron-impact dissociation for molecular oxygen are computed using ab initio resonance curves calculated with the R-matrix method. When O2 is in its vibrational ground state, the main contribution for both processes comes from the $^2\\Pi_u$ resonance state of $O_2^-$ but with a significant contribution from the $^4\\Sigma$ resonant state. Vibrational excitation leads to an increased contribution from the low-lying $^2\\Pi_{g}$ resonance, greatly increased cross sections for both processes, and the threshold moving to lower energies. These results provide important input for models of O2-containing plasmas in nonequilibrium conditions.

Laporta, V; Tennyson, J

2015-01-01T23:59:59.000Z

136

Photocatalysts of Cr Doped TiO2 Film Prepared by Micro Arc Oxidation  

Science Journals Connector (OSTI)

A series of Cr doped TiO2 films were prepared by micro arc oxidation (MAO) using an electrolyte of Na 3PO4+K2Cr2O7. X-ray diffraction and scanning electron microscopy revealed that the films mainly consisted of anatase phase with a porous surface morphology. The films have an excellent photocatalytic effect for degradation of methylene blue and decomposition of water under visible light illumination. This arises from the formation of Cr3+/Cr4+ and oxygen vacancy energy levels owing to Cr doping. The former reduces the electron-hole recombination chance while the latter generates a new gap between the conduction band (CB) and valence band (VB) of TiO2 which lowers the photo energy of the excited electron in the VB to the oxygen vacancy states. The mechanisms for film synthesis during the MAO process are also presented.

Li Wan; Jian-feng Li; Jia-you Feng; Wei Sun; Zong-qiang Mao

2008-01-01T23:59:59.000Z

137

Photooxidation and Photodesorption in the Photochemistry of Isobutene on TiO2(110)  

SciTech Connect

The photochemistry of isobutene was examined on the rutile TiO2(110) surface as a function of the surface pretreatment condition and irradiation temperature using temperature programmed desorption (TPD) and photon stimulated desorption (PSD). Isobutene adsorbs molecularly on the clean TiO2(110) surface without detectable thermal decomposition. Preadsorption of oxygen, either as atoms or chemisorbed molecules, did not promote thermal reactions with isobutene, but instead blocked isobutene adsorption sites. Ultraviolet (UV) light irradiation of isobutene adsorbed on the clean surface led to depletion through photodesorption without significant photodecomposition. Isobutene PSD yields increased with increasing surface temperature suggesting that activated molecules sample their physisorbed potential energy surface during photodesorption. Preadsorption of oxygen promoted partial photooxidation of adsorbed isobutene to acetone, methacrolein and isobutanal. Acetone was only detected when molecular oxygen was present, indicating that O2 addition occurred across the C=C bond. In contrast, results from use of D6-isobutene indicated that coadsorption with either O adatoms or O2 molecules led to photochemical production of methacrolein (and likely isobutanal) through C-H bond cleavage on a methyl group. Irradiation an adlayer comprised of isobutene isolated from the surface by 1 ML of preadsorbed O2 showed the most photoconversion of isobutene, which suggests that photoactivation of adsorbed O2 is a key step in partial photooxidation of isobutene. Comparison of the isobutene PSD and oxidation product yields as a function of surface temperature between 20 and 120 K indicates a competition between photooxidation and photodesorption that varies with temperature. Direct charge transfer events between isobutene and the surface, favored at higher temperature, compete with partial oxidation pathways initiated by indirect activation of isobutene by O2, which is favored at low temperature. Access of O2 to the surface is critical to achieving desired isobutene photooxidation rates and products, and isobutene photodesorption may provide a means of regulating the isobutene surface coverage. Work reported here was supported by the U.S. Department of Energy, Office of Basic Energy Science, Division of Chemical Sciences, Geosciences, and Biosciences, and performed in the Williams R. Wiley Environmental Molecular Science Laboratory (EMSL), a Department of Energy user facility funded by the Office of Biological and Environmental Research. Pacific Northwest National Laboratory is a multiprogram national laboratory operated for the U.S. Department of Energy by the Battelle Memorial Institute under contract DEAC05-76RL01830.

Henderson, Michael A.

2013-07-11T23:59:59.000Z

138

Prediction of O2 Dissociation Kinetics on LaMnO3-Based Cathode Materials for Solid Oxide Fuel Cells  

SciTech Connect

First-principles and statistical-theory calculations were applied to examine the interactions between oxygen molecules and the (100) surfaces of LaMnO3 and La0.5Sr0.5MnO2.75, one of the most-used cathode materials in solid oxide fuel cells (SOFCs). To predict the rate constants for the interactions between O2 and LaMnO3 or La0.5Sr0.5MnO2.75, potential energy profiles were constructed using the nudged elastic band (NEB) method. Predicted rate constants for the dissociation of adsorbed oxygen species on LaMnO3 (lm) and La0.5Sr0.5MnO2.75 (lsm) can be expressed as kdiss,lm ) 2.35 1012 exp(-0.50 eV/RT) s-1 and kdiss,lsm ) 2.15 1012 exp(-0.23 eV/RT) s-1, respectively, in the temperature range of 873-1273 K at 1 atm. Because the activation energy for oxygen dissociation on La0.5Sr0.5MnO2.75 (0.23 eV) is much smaller than that on LaMnO3 (0.50 eV), oxygen vacancies greatly enhance O2 dissociation kinetics. The kinetic and mechanistic studies for the interactions at the molecular level are imperative to gaining a fundamental understanding of oxygen reduction kinetics on cathode materials and to providing important insight into the rational design of more catalytically active cathode materials for SOFCs.

Choi, Yongman; Lynch, Matthew E.; Lin, M. C.; Liu, Meilin

2009-04-30T23:59:59.000Z

139

The O2 reduction at the IFC modified O2 fuel-cell electrode  

SciTech Connect

The International Fuel Corporation (IFC) state of the art (SOA) O2 electrode (Au-10 percent Pt electrocatalyst by weight) is currently being used in the alkaline H2-O2 fuel cell in the NASA Space Shuttle. Recently, IFC modified O2 electrode, as a possible replacement for the SOA electrode. In the present study, O2 reduction data were obtained for the modified electrode at temperatures between 23.3 and 91.7 C. BET measurements gave an electrode BET surface area of about 2070 sq. cm/sq. cm of geometric surface area. The Tafel data could be fitted to two straight line regions. The slope for the lower region, designated as the 0.04 V/decade region, was temperature dependent, and the transfer coefficient was about 1.5. The 'apparent' energy of activation for this region was about 19 kcal/mol. An O2 reduction mechanism for this 0.04 region is presented. In the upper region, designated as the 0.08 V/decade region, diffusion may be the controlling process. Tafel data are presented to illustrate the increase in performance with increasing temperature.

Fielder, W.L.; Singer, J.; Baldwin, R.S.; Johnson, R.E.

1992-07-01T23:59:59.000Z

140

Nanostructured F doped IrO2 electro-catalyst powders for PEM based water electrolysis  

Science Journals Connector (OSTI)

Abstract Fluorine doped iridium oxide (IrO2:F) powders with varying F content ranging from 0 to 20wt.% has been synthesized by using a modification of the Adams fusion method. The precursors (IrCl4 and NH4F) are mixed with NaNO3 and heated to elevated temperatures to form high surface area nanomaterials as electro-catalysts for PEM based water electrolysis. The catalysts were then coated on a porous Ti substrate and have been studied for the oxygen evolution reaction in PEM based water electrolysis. The IrO2:F with an optimum composition of IrO2:10wt.% F shows remarkably superior electrochemical activity and chemical stability compared to pure IrO2. The results have also been supported via kinetic studies by conducting rotating disk electrode (RDE) experiments. The RDE studies confirm that the electro-catalysts follow the two electron transfer reaction for electrolysis with calculated activation energy of ?25kJmol?1. Single full cell tests conducted also validate the superior electrochemical activity of the 10wt.% F doped IrO2.

Karan Sandeep Kadakia; Prashanth H. Jampani; Oleg I. Velikokhatnyi; Moni Kanchan Datta; Sung Kyoo Park; Dae Ho Hong; Sung Jae Chung; Prashant N. Kumta

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "atmospheric oxygen o2" 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

Chemical and Electrochemical Differences in Nonaqueous LiO2 and NaO2 Batteries  

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The most intriguing difference between the two batteries is their respective galvanostatic charging overpotentials: a NaO2 battery exhibits a low overpotential throughout most of its charge, whereas a LiO2 battery has a low initial overpotential that continuously increases to very high voltages by the end of charge. ... Li metal was purchased from FMC, Na metal was purchased from GalliumSource, P50 Avcarb carbon paper was purchased from the Fuel Cell Store, and Whatman glass fiber filters (QM-A grade) were used as the separator. ...

Bryan D. McCloskey; Jeannette M. Garcia; Alan C. Luntz

2014-03-17T23:59:59.000Z

142

Hierarchical mesoporous perovskite La0.5Sr0.5CoO2.91 nanowires with ultrahigh capacity for Li-air batteries  

Science Journals Connector (OSTI)

...active bifunctional electrocatalyst for rechargeable lithium-air...methanol-tolerant oxygen reduction electrocatalyst . J Am Chem Soc 134 ( 4...and Cu) as anode electrocatalyst for direct methanol fuel...PG ( 2007 ) An O 2 cathode for rechargeable lithium...Y ( 2011 ) Method development to evaluate the oxygen...

Yunlong Zhao; Lin Xu; Liqiang Mai; Chunhua Han; Qinyou An; Xu Xu; Xue Liu; Qingjie Zhang

2012-01-01T23:59:59.000Z

143

Time-Resolved EPR Study of Singlet Oxygen in the Gas Phase Marco Ruzzi,  

E-Print Network (OSTI)

Time-Resolved EPR Study of Singlet Oxygen in the Gas Phase Marco Ruzzi, Elena Sartori, Alberto States ABSTRACT: X-band EPR spectra of singlet O2(1 g) and triplet O2(3 g - ) were observed in the gas, and perfluoronaphthalene in the gas phase. The EPR spectrum of O2(1 g) was also observed under microwave discharge

Turro, Nicholas J.

144

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

E-Print Network (OSTI)

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

Chan, Sharleen

145

Oxygen Loss from Venus and the Influence of Extreme Solar Wind Conditions  

E-Print Network (OSTI)

and I. Sillanp (2009), Oxygen ion escape from Venus in aobservations of atmospheric oxygen escape during the passageI. F. Stewart (1981), Hot oxygen BIBLIOGRAPHY atoms in the

McEnulty, Tess

2012-01-01T23:59:59.000Z

146

Optical dissolved oxygen sensor utilizing molybdenum chloride cluster phosphorescence  

E-Print Network (OSTI)

in oxygen atmospheres 0%­21% were obtained with a signal to noise ratio better than 150. Photobleaching physical principles, electrochemistry or luminescence. Electrochemical devices result in analyte

Ghosh, Ruby N.

147

Reduction Kinetics of Cu-Based Oxygen Carriers for Chemical Looping Air Separation  

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Only Sahir et al. performed a rate analysis from the reported batch fluidized bed CLOU experimental data of Mexican petcoke particles by a CuO/ZrO2 oxygen carrier. ... data of Mexican petcoke particles by a CuO/ZrO2 oxygen carrier. ...

Kun Wang; Qingbo Yu; Qin Qin

2013-08-02T23:59:59.000Z

148

(Fe1-xMnx)TiyO3 based Oxygen Carriers for Chemical-looping Combustion and Chemical-looping with Oxygen Uncoupling  

Science Journals Connector (OSTI)

Abstract The manganese based ilmenite analogue pyrophanite (MnTiO3) and six other combined (Fe1-xMnx)TiyO3 oxides have been examined as oxygen-carrier materials for chemical-looping combustion (CLC) and chemical-looping with oxygen uncoupling (CLOU). Particles with different compositions were manufactured by spray drying and studied by consecutive reduction and oxidation at 850-1050C in a batch fluidized-bed reactor using CH4 as fuel. A fuel conversion of 80-99% could be achieved with most materials, with different formulations being favored at different temperature levels. The exception was pure MnTiO3 which had very limited reactivity with CH4. The oxygen uncoupling behavior was examined by exposing the oxygen-carrier particles to an inert atmosphere of N2. The apparent equilibrium concentration during fluidization with pure N2 ranged from zero to 0.9% O2, depending on temperature and particle composition. One material (Fe0.50Mn0.50)TiO3 was selected and further examined by 12h of experiments in a small continuously operating circulating fluidized-bed reactor. Up to 80% conversion of natural gas was achieved at 910C, but defluidization occurred when the temperature was increased to 950C.

Magnus Rydn; Malin Klln; Dazheng Jing; Ali Hedayati; Tobias Mattisson; Anders Lyngfelt

2014-01-01T23:59:59.000Z

149

Journal of Power Sources 156 (2006) 345354 Development of PtRu-CeO2/C anode electrocatalyst for  

E-Print Network (OSTI)

Journal of Power Sources 156 (2006) 345­354 Development of PtRu-CeO2/C anode electrocatalyst a growing interest in the development of direct methanol fuel cells (DMFCs) because when compared oxidation reac- tion on the anode and the oxygen reduction reaction on the cathode remains as one

Zhao, Tianshou

150

The generation of singlet Delta oxygen - A technology overview. [For use in chemical oxygen iodine lasers  

SciTech Connect

The rate of generation of O2(1Delta g) using the chlorine-basic-hydrogen-peroxide reaction is a key element to predict the performance of the chemical oxygen iodine laser. O2(1Delta g) carries the energy in the laser, and thus is one of the prime determinants of power in the flow. To predict the performance of O2(1Delta g) generators requires the prediction of the utilization of chlorine, the yield of excited oxygen, and the concentration of potential contaminants in the chemical exhaust of the generator. This paper describes an approach to the analysis of O2(1Delta g) generators. 6 refs.

Mcdermott, W.E. (Rockwell International Corp., Rocketdyne Div., Canoga Park, CA (United States))

1992-07-01T23:59:59.000Z

151

Chemistry of NOx on TiO2 surfaces studied by ambient pressure XPS:  

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Chemistry of NOx on TiO2 surfaces studied by ambient pressure XPS: Chemistry of NOx on TiO2 surfaces studied by ambient pressure XPS: products, effect of UV irradiation, water and coadsorbed K+ Title Chemistry of NOx on TiO2 surfaces studied by ambient pressure XPS: products, effect of UV irradiation, water and coadsorbed K+ Publication Type Journal Article Year of Publication 2013 Authors Rosseler, Olivier, Mohamad Sleiman, Nahuel V. Montesinos, Andrey Shavorskiy, Valerie Keller, Nicolas Keller, Marta I. Litter, Hendrik Bluhm, Miquel Salmeron, and Hugo Destaillats Journal J. Phys. Chem. Lett. Volume 4 Start Page 536 Issue 3 Pagination 536-541 Date Published 01/2013 Abstract Self-cleaning surfaces containing TiO2 nanoparticles have been postulated to efficiently remove NOx from the atmosphere. However, UV irradiation of NOx adsorbed on TiO2 also was shown to form harmful gas-phase byproducts such as HONO and N2O that may limit their depolluting potential. Ambient pressure XPS was used to study surface and gas-phase species formed during adsorption of NO2 on TiO2 and subsequent UV irradiation at λ = 365 nm. It is shown here that NO3-, adsorbed on TiO2 as a byproduct of NO2 disproportionation, was quantitatively converted to surface NO2 and other reduced nitrogenated species under UV irradiation in the absence of moisture. When water vapor was present, a faster NO3- conversion occurred, leading to a net loss of surface-bound nitrogenated species. Strongly adsorbed NO3- in the vicinity of coadsorbed K+ cations was stable under UV light, leading to an efficient capture of nitrogenated compounds.

152

Atmospheric Chemistry  

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competencies Atmospheric Chemistry Atmospheric Chemistry is the study of the composition of the atmosphere, the sources and fates of gases and particles in air, and changes induced...

153

Advanced Visible-Light-Driven Self-Cleaning Cotton by Au/TiO2/SiO2 Photocatalysts  

Science Journals Connector (OSTI)

Synergy of Low-Energy {101} and High-Energy {001} TiO2 Crystal Facets for Enhanced Photocatalysis ... Synergy of Low-Energy {101} and High-Energy {001} TiO2 Crystal Facets for Enhanced Photocatalysis ...

RongHua Wang; XiaoWen Wang; John H. Xin

2009-10-29T23:59:59.000Z

154

SiC performance of coated fuel particles under high-temperature atmosphere of air  

Science Journals Connector (OSTI)

Abstract To better understand whether the SiC layer can withstand the corrosion given by the chemical reaction between SiC and O2, our experiments focused mainly on the effect of oxygen on SiC-coated fuel particles at high temperature. Tests were conducted on non-irradiated coated fuel particles in an atmosphere of air over a range of temperatures between 800 and 1600C. This paper summarizes the failure fractions, surface morphology and microstructure of the SiC coating, etc. The morphology of SiC-coated particles surfaces, optical and scanning electron micrographs and the oxygen distribution of polished SiC layers at 800, 1000 and 1200C for 200h under air atmosphere showed that the features of SiC layers did not change in these cases. In contrast with the aforementioned cases, the behavior of SiC layers was deteriorated when the oxidation temperature was beyond 1400C. More serious the deterioration, higher the oxidation temperature is. The thickness of SiO2 layer from outside to inside SiC layers reached 6 ?8?m, and a large number of SiC-coated particles were broken into fragment at 1600C. The experiment results show that the oxidation of the SiC layer proceeds slowly at temperatures around 1400C and more rapidly as the temperature approaches 1600C.

Chunhe Tang; Bing Liu; Ziqiang Li; Ying Quan; Hongsheng Zhao; Youlin Shao

2014-01-01T23:59:59.000Z

155

High-rate HMDSO-based coatings in open air using atmospheric-pressure plasma jet  

Science Journals Connector (OSTI)

This work deals with the high-rate and dust-free formation of carbon-containing silicon oxide (SiOC) coatings in open air without substrate heating using an atmospheric-pressure (AP) plasma jet. The AP plasma was excited by a 13.56-MHz radio frequency (RF) power. Hexamethyldisiloxane and oxygen (O2) were used as the source gases. By optimizing the O2 flow rate and RF power, SiOC films were readily fabricated at deposition rates higher than 100nm/s without suffering from particulate contaminations of the film surface. Additionally, an inorganic SiO2-like film exhibiting O/Si atomic ratio of approximately 2 was obtained at a deposition rate of ~13 nm/s, the value of which is still greater than those obtained in other AP plasma sources. Further systematic studies are needed to see if good-quality inorganic SiO2-like films can be obtained with higher rates.

H. Kakiuchi; K. Higashida; T. Shibata; H. Ohmi; T. Yamada; K. Yasutake

2012-01-01T23:59:59.000Z

156

Anoxygenic photosynthesis modulated Proterozoic oxygen and sustained Earth's middle age  

E-Print Network (OSTI)

Anoxygenic photosynthesis modulated Proterozoic oxygen and sustained Earth's middle age D. T photosynthesis to overall primary production would have influ- enced oceanic redox and the Proterozoic O2 budget time in Earth's history, complete dominance of oxygenic photosynthesis in the oceans. This paved

Macalady, Jenn

157

Development of Antimicrobial Coatings by Atmospheric Pressure Plasma Using a Guanidine-Based Precursor  

Science Journals Connector (OSTI)

Atmospheric pressure plasmas have been utilized in the engineering of antimicrobial materials, where their applications ranged from surface pretreatment of substrates for enhanced bonding of silver nanoparticles or antimicrobial agents in imparting antimicrobial behavior on surfaces spanning from pretreatments of substrate materials(13, 14) and very recently, deposition and/or plasma polymerization of antimicrobial polymers using monomer precursors. ... (20) Similar results of oxidized polar groups such as hydroxyls, carbonyls, and carboxyl groups on the surfaces of UHMWPE films from water vapor plasma treatments have been reported by Rodriguez-Santiago et al.(21) Also, reactive species such as ozone, O2, and O generated from plasma interactions with air from open atmosphere are also an underlying source of oxygen-bearing groups. ...

Jacqueline H. Yim; Michelle S. Fleischman; Victor Rodriguez-Santiago; Lars T. Piehler; Andr A. Williams; Julia L. Leadore; Daphne D. Pappas

2013-10-29T23:59:59.000Z

158

Photochemical Escape of Oxygen from Early Mars  

E-Print Network (OSTI)

Photochemical escape is an important process for oxygen escape from present Mars. In this work, a 1-D Monte-Carlo Model is developed to calculate escape rates of energetic oxygen atoms produced from O2+ dissociative recombination reactions (DR) under 1, 3, 10, and 20 times present solar XUV fluxes. We found that although the overall DR rates increase with solar XUV flux almost linearly, oxygen escape rate increases from 1 to 10 times present solar XUV conditions but decreases when increasing solar XUV flux further. Analysis shows that atomic species in the upper thermosphere of early Mars increases more rapidly than O2+ when increasing XUV fluxes. While the latter is the source of energetic O atoms, the former increases the collision probability and thus decreases the escape probability of energetic O. Our results suggest that photochemical escape be a less important escape mechanism than previously thought for the loss of water and/or CO2 from early Mars.

Zhao, Jinjin

2015-01-01T23:59:59.000Z

159

O2 reduction at the IFC orbiter fuel cell O sub 2 electrode  

SciTech Connect

O2 reduction Tafel data were obtained for the IFC Orbiter fuel cell O2 electrode (Au-10 percent Pt catalyst) at temperatures between 24 and 81 C. BET measurements gave an electrode surface area of about 2040 sq cm per sq cm of geometric area. The Tafel data could be fitted to three straight line regions. For current densities less than 0.001 A/sq cm, the slope was essentially independent of temperature with a value of about 0.032 V/decade. Above 0.001 A/sq cm, the two regions, designated in the present study as the 0.04 and 0.12 V/decate regions, were temperature dependent. The apparent energies of activation for these two regions were about 9.3 and 6.5 kcal/mol, respectively. Tafel data (1 atmosphere O2) were extrapolated to 120 C for predicting changes in overpotential with increasing temperature. A mechanism is presented for O2 reduction.

Fielder, W.L.; Singer, J.

1990-04-01T23:59:59.000Z

160

Photocatalytic H2 production from ethanol over Au/TiO2 and Ag/TiO2  

Science Journals Connector (OSTI)

This paper compares the photocatalytic activities of Au/TiO2 (Au loadings 0-4 wt.%) and Ag/TiO2 photocatalysts (Ag loadings 0-4 wt.%) for H2 production from ethanol-water mixtures under UV irradiation. Au and Ag nanoparticles were deposited on commercially available Degussa P25 TiO2 (85% anatase, 15% rutile) using deposition-precipitation and liquid impregnation methods, respectively. TEM analyses showed the average noble metal nanoparticle size to be ~5 nm for the Au/TiO2 photocatalysts and ~3 nm for the Ag/TiO2 photocatalysts. Au/TiO2 photocatalysts showed a strong localised surface plasmon resonance (LSPR) at 570 nm characteristic for nanocrystalline Au. Complementary XRD studies confirmed that Au and Ag nanoparticles were present in metallic form. Photoluminescence measurements revealed that Au and Ag nanoparticles effectively suppress electron-hole recombination in TiO2, thereby enhancing the photocatalytic activity of TiO2 for hydrogen production. Au/TiO2 photocatalysts were far more active for H2 production from ethanol-water mixtures than Ag/TiO2 photocatalysts. A 1 wt.% Au/TiO2 photocatalyst yielded the highest H2 production rate (34 mmol g?1 h?1). Amongst the Ag/TiO2 photocatalysts, the 2 wt.% Ag/TiO2 sample was the most active (3.7 mmol g?1 h?1). Results are rationalised in terms of differences in the electronic properties of supported Au and Ag nanoparticles, with the former being near ideal for H2 production.

Vedran Jovic; Pei-Huan Hsieh; Wan-Ting Chen; Dongxiao Sun-Waterhouse; Tilo Söhnel; Geoffrey I.N. Waterhouse

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "atmospheric oxygen o2" 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-Field Magnetoresistance of IrO2  

Science Journals Connector (OSTI)

The monotonic and oscillatory magnetoresistance of IrO2 is reported and found to be consistent with the Fermi-surface model proposed by Graebner.

W. D. Ryden; W. A. Reed; E. S. Greiner

1972-09-15T23:59:59.000Z

162

Dry etching properties of TiO2 thin films in O2/CF4/Ar plasma  

Science Journals Connector (OSTI)

In this work, the etching properties of titanium dioxide (TiO2) thin film in additions of O2 at CF4/Ar plasma were investigated. The maximum etch rate of 179.4nm/min and selectivity of TiO2 of 0.6 were obtained at an O2/CF4/Ar (=3:16:4sccm) gas mixing ratio. In addition, the etch rate and selectivity were measured as a function of the etching parameters, such as the RF power, DC-bias voltage, and process pressure. The efficient destruction of the oxide bonds by ion bombardment, which was produced from the chemical reaction of the etched TiO2 thin film, was investigated by X-ray photoelectron spectroscopy. To determine the re-deposition of sputter products and reorganization of such residues on the surface, the surface roughness of TiO2 thin film were examined using atomic force microscopy.

Kyung-Rok Choi; Jong-Chang Woo; Young-Hee Joo; Yoon-Soo Chun; Chang-Il Kim

2013-01-01T23:59:59.000Z

163

Modeling of durability of polyelectrolyte membrane of O2/H2 fuel cell  

E-Print Network (OSTI)

In this paper, we discuss critical aspects of the mechanisms and features of polymer proton exchange membrane (PEM) degradation in low-temperature H2/O2 fuel cell. In this paper, we focused on chemical mechanism of OH radical generation and their distribution in operational fuel cell. According to the current concept, free radicals are generated from hydrogen and oxygen crossover gases at the surface of Pt particles that precipitated in the membrane. We explicitly calculate Pt precipitation rate and electrochemical potential distribution in the membrane that controls it. Based on radical generation rate and Pt distribution we calculate degradation rate of the membrane taking advantage of simple kinetics equations.

Atrazhev, Vadim V

2014-01-01T23:59:59.000Z

164

Acetone-Assisted Oxygen Vacancy Diffusion on TiO2(110). | EMSL  

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

Instruments: Ultra-high Vacuum, Low-temperature Scanning Probe Microscope Instrument, or UHV LT SPM Tags: adsorbate-covered solid surfaces space probe defect structures oxides...

165

Synthesis and Electrochemical Oxygen Reduction of Platinum Nanoparticles Supported on Mesoporous TiO2  

Science Journals Connector (OSTI)

Structural and morphological properties of the prepared electrocatalyst were characterized by X-ray diffraction (XRD), Brunnier Emmet Teller (BET), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDX). ... (1) In recent years, there have been extensive efforts in the development of fuel cell materials (electrode catalysts, membranes, and supports). ... The main characteristics of an ideal support for PEMFC electrocatalysts would be (i) reasonable electrical conductivity; (ii) good metal?carbon interaction; (iii) high surface area; (iv) a mesoporous structure which enables the filling of the ionomer or polymer electrolyte to bring the catalyst particles close to the reactants, thus maximizing the triple-phase interface; (v) good water handling capability, particularly at the cathode side to avoid electrode flooding; (vi) better corrosion resistance, especially at the anode side. ...

Sangaraju Shanmugam; Aharon Gedanken

2009-10-02T23:59:59.000Z

166

Oxygen production and carbon sequestration in an upwelling coastal Burke Hales,1  

E-Print Network (OSTI)

Oxygen production and carbon sequestration in an upwelling coastal margin Burke Hales,1 Lee Karp), Oxygen production and carbon sequestration in an upwelling coastal margin, Global Biogeochem. Cycles, 20 of particulate organic carbon (POC) and dissolved O2 during the upwelling season off the Oregon coast. Oxygen

Pierce, Stephen

167

Oxygen Isotope Effects as Probes of Electron Transfer Mechanisms and Structures of  

E-Print Network (OSTI)

Oxygen Isotope Effects as Probes of Electron Transfer Mechanisms and Structures of Activated O2, Maryland 21218 RECEIVED ON JULY 26, 2008 C O N S P E C T U S Competitively determined oxygen (18 O) isotope effects can be power- ful probes of chemical and biological transformations involving molec- ular oxygen

Roth, Justine P.

168

Tunneling states in vitreous GeO2s  

Science Journals Connector (OSTI)

Ultrasonic measurements of the attenuation and the velocity variation have been carried out in amorphous GeO2 at low temperature (0.310 K) and high frequencies (80210 MHz). From numerical fits to the tunneling model, the typical parameters of the tunneling states (TS) were determined and compared to those found for vitreous SiO2 . The study reveals that in a-GeO2 , which is considered as a close structural analog to a-SiO2 , although the density of states is found to be very similar in both materials, the coupling between the TS and the phonons is significantly smaller. In the model of coupled tetrahedra as the origin of the TS, this difference can be understood in view of the fact that numerical calculations about the vibrational characteristics of network amorphous solids indicate that the tetrahedra are more decoupled in vitreous GeO2 than in vitreous silica.

Christiane Laermans; Veerle Keppens; Robert Weeks

1997-02-01T23:59:59.000Z

169

Oxygen Transport Ceramic Membranes  

SciTech Connect

The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and studies on newer composition of Ti doped LSF. The in situ electrical conductivity and Seebeck coefficient measurements were made on LSFT at 1000 and 1200 C over the oxygen activity range from air to 10{sup -15} atm. The electrical conductivity measurements exhibited a p to n type transition at an oxygen activity of 1 x 10{sup -10} at 1000 C and 1 x 10{sup -6} at 1200 C. Thermogravimetric studies were also carried out over the same oxygen activities and temperatures. Based on the results of these measurements, the chemical and mechanical stability range of LSFT were determined and defect structure was established. The studies on the fracture toughness of the LSFT and dual phase membranes exposed to air and N{sub 2} at 1000 C was done and the XRD and SEM analysis of the specimens were carried out to understand the structural and microstructural changes. The membranes that are exposed to high temperatures at an inert and a reactive atmosphere undergo many structural and chemical changes which affect the mechanical properties. A complete transformation of fracture behavior was observed in the N{sub 2} treated LSFT samples. Further results to investigate the origin of the slow kinetics on reduction of ferrites have been obtained. The slow kinetics appear to be related to a non-equilibrium reduction pathway that initially results in the formation of iron particles. At long times, equilibrium can be reestablished with recovery of the perovskite phase. Recent results on transient kinetic data are presented. The 2-D modeling of oxygen movement has been undertaken in order to fit isotope data. The model is used to study ''frozen'' profiles in patterned or composite membranes.

S. Bandopadhyay; T. Nithyanantham; X.-D Zhou; Y-W. Sin; H.U. Anderson; Alan Jacobson; C.A. Mims

2005-02-01T23:59:59.000Z

170

Thermal stability of ZrO2SiO2 aerogel modified by Fe(III) ion  

Science Journals Connector (OSTI)

ZrO2SiO2 aerogel modified by Fe(III) ion was prepared and the stability of the samples under high temperature was investigated. The structure and properties of modified aerogels were characterized by N2 adsorpti...

Rui Xiong; Xiaolei Li; Huiming Ji

2014-08-01T23:59:59.000Z

171

The decomposition of H2O2 over the components of Au/TiO2catalysts  

Science Journals Connector (OSTI)

...the selectivity to H2O2 from hydrogen is practically 100 per cent...to end users. The in situ production of hydrogen peroxide from O2 and H2 promises...localized, small-scale production method with lower environmental and...

2011-01-01T23:59:59.000Z

172

Atmospheric Chemistry of Dichlorvos  

Science Journals Connector (OSTI)

Atmospheric Chemistry of Dichlorvos ... In the positive ion mode, protonated water hydrates (H3O+(H2O)n) generated by the corona discharge in the chamber diluent air were responsible for the protonation of analytes, and the ions that were mass analyzed were mainly protonated molecules ([M + H]+) and their protonated homo- and heterodimers. ... Methyl nitrite, 2-propyl nitrite and N2O5 were prepared and stored as described previously,(8, 10) and O3 in O2 diluent was generated using a Welsbach T-408 ozone generator. ...

Sara M. Aschmann; Ernesto C. Tuazon; William D. Long; Roger Atkinson

2011-03-15T23:59:59.000Z

173

Magnetic properties of epitaxial Co-doped anatase TiO2 thin films with excellent structural quality  

SciTech Connect

The heteroepitaxy of Co-doped anatase TiO2 on LaAlO3(001) has been refined with the goal of determining the relationship between structural quality and magnetic ordering. By significantly reducing the deposition rate and substrate temperature, well-ordered Co:TiO2 films with unprecedented crystalline quality were obtained by oxygen-plasma-assisted molecular beam epitaxy, as characterized by x-ray diffraction. These films exhibit uniform Co doping, with no evidence of Co segregation or secondary phases throughout the film depth or on the surface. Despite the improvement in crystalline quality and Co distribution, the films exhibit negligible ferromagnetism, with saturation moments of only ~0.1 ?B/Co. This loss of ferromagnetism is in stark contrast to faster-grown Co:TiO2 films, where a higher growth rate and substrate temperature typically result in lower crystalline quality, a highly non-uniform Co distribution, and average saturation moments of ~1.2 ?B/Co. The presence of ferromagnetism in faster-grown Co:TiO2 does not appear to arise from intrinsic point defects present in the bulk material, such as charge-compensating oxygen vacancies, but is instead attributed to the presence of extended structural defects.

Kaspar, Tiffany C.; Droubay, Timothy C.; McCready, David E.; Nachimuthu, Ponnusamy; Heald, Steve M.; Wang, Chong M.; Lea, Alan S.; Shutthanandan, V.; Chambers, Scott A.; Toney, Michael F.

2006-07-26T23:59:59.000Z

174

Oxygen Transport Ceramic Membranes  

SciTech Connect

The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and studies on newer composition of Ti doped LSF. Thermogravimetric analysis (TGA) was carried out on La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} to investigate oxygen deficiency ({delta}) of the sample. The TGA was performed in a controlled atmosphere using oxygen, argon, carbon monoxide and carbon dioxide with adjustable gas flow rates. In this experiment, the weight loss and gain of La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} was directly measured by TGA. The weight change of the sample was evaluated at between 600 and 1250 C in air or 1000 C as a function of oxygen partial pressure. The oxygen deficiencies calculated from TGA data as a function of oxygen activity and temperature will be estimated and compared with that from neutron diffraction measurement in air. The LSFT and LSFT/CGO membranes were fabricated from the powder obtained from Praxair Specialty Ceramics. The sintered membranes were subjected to microstructure analysis and hardness analysis. The LSFT membrane is composed of fine grains with two kinds of grain morphology. The grain size distribution was characterized using image analysis. In LSFT/CGO membrane a lot of grain pullout was observed from the less dense, porous phase. The hardness of the LSFT and dual phase membranes were studied at various loads. The hardness values obtained from the cross section of the membranes were also compared to that of the values obtained from the surface. An electrochemical cell has been designed and built for measurements of the Seebeck coefficient as a function of temperature and pressure. Measurements on La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} as a function of temperature an oxygen partial pressure are reported. Further analysis of the dilatometry data obtained previously is presented. A series of isotope transients under air separation mode (small gradient) were completed on the membrane of LSCrF-2828 at 900 C. Low pO{sub 2} atmospheres based on with CO-CO{sub 2} mixtures have also been admitted to the delivery side of the LSCrF-2828 membrane to produce the gradients which exist under syngas generation conditions. The CO-CO{sub 2} mixtures have normal isotopic {sup 18}O abundances. The evolution of {sup 18}O on the delivery side in these experiments after an {sup 18}O pulse on the air side reveals a wealth of information about the oxygen transport processes.

S. Bandopadhyay; N. Nagabhushana; T. Nithyanantham; X.-D Zhou; Y-W. Sin; H.U. Anderson; Alan Jacobson; C.A. Mims

2005-02-01T23:59:59.000Z

175

A survey of alternative oxygen production technologies  

Science Journals Connector (OSTI)

Utilization of the Martian atmosphere for the production of fuel and oxygen has been extensively studied. The baseline fuel production process is a Sabatier reactor which produces methane and water from carbon dioxide and hydrogen. The oxygen produced from the electrolysis of the water is only half of that needed for methane-based rocket propellant and additional oxygen is needed for breathing air fuel cells and other energy sources. Zirconia electrolysis cells for the direct reduction of CO 2 are being developed as an alternative means of producing oxygen but present many challenges for a large-scale oxygen production system. The very high operating temperatures and fragile nature of the cells coupled with fairly high operating voltages leave room for improvement. This paper will survey alternative oxygen production technologies present data on operating characteristics materials of construction and some preliminary laboratory results on attempts to implement each.

Dale E. Lueck; Clyde F. Parrish; William J. Buttner; Jan M. Surma

2001-01-01T23:59:59.000Z

176

Bi3+ Luminescence in ABiO2Cl (A = Sr, Ba) and BaBiO2Br  

SciTech Connect

Trivalent bismuth luminescence is reported in three Sillenbismuth oxyhalide phases, SrBiO2Cl, BaBiO2Cl, and BaBiO2Br. Thesecompounds exhibit Bi 6s6->6 s2 emission under UV and X-ray radiation.At room temperature, BaBiO2Cl shows the most intense light emission, withspectral and decay properties similar to those found in Bi4Ge3O12 (BGO).At low temperatures, each phase show an increase in the photoluminescenceintensities and a narrowing of the emission peaks. In contrast to thetemperature dependence of BGO, X-ray excited luminescence intensities ofall three phases remain relatively constant throughout the temperaturerange 10 - 295 K. This result indicates that the Sillen phases undergoless thermal quenching than BGO. The low temperature and room temperatureradio-luminescence decay times were determined from pulsed x-raymeasurements. At room temperature, SrBiO2Cl exhibits faster decays thanBGO, while, BaBiO2Cl and BaBiO2Br have decay times similar toBGO.

Porter-Chapman, Yetta D.; Bourret-Courchesne, Edith E.; Derenzo,Stephen E.

2007-01-18T23:59:59.000Z

177

Oxygen to the core  

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

1-01 1-01 For immediate release: 01/10/2013 | NR-13-01-01 Oxygen to the core Anne M Stark, LLNL, (925) 422-9799, stark8@llnl.gov Printer-friendly An artist's conception of Earth's inner and outer core. LIVERMORE, Calif. -- An international collaboration including researchers from Lawrence Livermore National Laboratory has discovered that the Earth's core formed under more oxidizing conditions than previously proposed. Through a series of laser-heated diamond anvil cell experiments at high pressure (350,000 to 700,000 atmospheres of pressure) and temperatures (5,120 to 7,460 degrees Fahrenheit), the team demonstrated that the depletion of siderophile (also known as "iron loving") elements can be produced by core formation under more oxidizing conditions than earlier

178

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect

This report covers the following tasks: Task 1--Design, fabricate and evaluate ceramic to metal seals based on graded ceramic powder/metal braze joints; Task 2--Evaluate the effect of defect configuration on ceramic membrane conductivity and long term chemical and structural stability; Task 3--Determine materials mechanical properties under conditions of high temperatures and reactive atmospheres; Task 4--Evaluate phase stability and thermal expansion of candidate perovskite membranes and develop techniques to support these materials on porous metal structures; Task 5--Assess the microstructure of membrane materials to evaluate the effects of vacancy-impurity association, defect clusters, and vacancy-dopant association on the membrane performance and stability; and Task 6--Measure kinetics of oxygen uptake and transport in ceramic membrane materials under commercially relevant conditions using isotope labeling techniques.

Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

2002-04-01T23:59:59.000Z

179

Ferromagnetism in chemically synthesized CeO2 nanoparticles by...  

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

by Ni doping. Ferromagnetism in chemically synthesized CeO2 nanoparticles by Ni doping. Abstract: This work reports the discovery of room-temperature ferromagnetism in 5 - 9 nm...

180

Effect of ceria loading on the carbon formation during low temperature methane steam reforming over a Ni/CeO2/ZrO2 catalyst  

Science Journals Connector (OSTI)

The characterization and catalytic activity of a Ni/CeO2/ZrO2 catalyst for methane steam reforming at 600C were investigated. The addition...

Anton Purnomo; Susan Gallardo; Leonila Abella

2008-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "atmospheric oxygen o2" 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

Chapter 6 - Coal Combustion in Atmosphere  

Science Journals Connector (OSTI)

Abstract The performance of two different burner designs, single central orifice (SCO) and single annular orifice (SAO), was examined under oxycoal conditions in a downfired oxycoal pilot plant. Based on detailed in-flame measurements combined with CFD predictions, the main parameters influencing the stability of an O 2 / CO 2 pulverised coal swirl flame were identified and investigated. The oxycoal flame was experimentally stabilised at the burner quarl by: increasing O 2 concentration above 34 vol% without changes to the air-firing burner design and by modification of the burner geometry thus changing the aerodynamics. The modification of the burner allowed a decrease of the O 2 concentrations to 23 vol% for the SCO burner and to less than 19 vol% for the SAO burner. Comprehensive experimental data for axial and tangential velocity, flue gas temperature, oxygen and NO concentrations, and particle temperature for stable oxyfiring at 21 vol% O 2 is presented. Scaling up to 100kW of the SAO burner was carried out and experimental tests confirmed flame stabilisation at the burner quarl under oxycoal conditions with 21 vol% O 2 in the O 2 / CO 2 mixture. Furthermore, the burner was successfully tested in both oxycoal conditions using RFG (wet recycling) and in conventional air combustion. The tests demonstrated the ability of the burner to form a stable swirl flame and to provide good burnout in all three combustion modes, namely in air, in O 2 / CO 2 , and in O 2 / RFG .

Dobrin D. Toporov

2014-01-01T23:59:59.000Z

182

Superhydrophilic TiO2 surface without photocatalytic activation  

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

Superhydrophilic TiO2 surface without photocatalytic activation Superhydrophilic TiO2 surface without photocatalytic activation Title Superhydrophilic TiO2 surface without photocatalytic activation Publication Type Journal Article Year of Publication 2010 Authors Zormpa, Vasileia, Xiaobo Chen, and Samuel S. Mao Journal Applied Physics Letter Volume 96 Issue 9 Date Published 12/2009 Abstract Since the discovery of extreme surface wetting phenomenon induced by ultraviolet photocatalysis, TiO2 has become the material of choice for environmental friendly applications such as self-cleaning coatings. Nevertheless, it remains a significant challenge to realize surfaces exhibiting persistent superhydrophilicity but without the need of external stimuli. We report a bioinspired TiO2 nanostructure that shows extreme superhydrophilicity without the need of light activation, and with stability against successive wetting-dewetting cycles. This ultimate TiO2 wetting surface exhibits high transmittance from near ultraviolet to the infrared, thus enabling practical antifogging technologies where transparency is critical.

183

E-Print Network 3.0 - atomic oxygen environmental Sample Search...  

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

Powered by Explorit Topic List Advanced Search Sample search results for: atomic oxygen environmental Page: << < 1 2 3 4 5 > >> 1 TiO2-rich reconstructions of SrTiO3(001): a...

184

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect

This is the third quarterly report on oxygen Transport Ceramic Membranes. In the following, the report describes the progress made by our university partners in Tasks 1 through 6, experimental apparatus that was designed and built for various tasks of this project, thermodynamic calculations, where applicable and work planned for the future. (Task 1) Design, fabricate and evaluate ceramic to metal seals based on graded ceramic powder/metal braze joints. (Task 2) Evaluate the effect of defect configuration on ceramic membrane conductivity and long term chemical and structural stability. (Task 3) Determine materials mechanical properties under conditions of high temperatures and reactive atmospheres. (Task 4) Evaluate phase stability and thermal expansion of candidate perovskite membranes and develop techniques to support these materials on porous metal structures. (Task 5) Assess the microstructure of membrane materials to evaluate the effects of vacancy-impurity association, defect clusters, and vacancy-dopant association on the membrane performance and stability. (Task 6) Measure kinetics of oxygen uptake and transport in ceramic membrane materials under commercially relevant conditions using isotope labeling techniques.

Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

2000-10-01T23:59:59.000Z

185

Electrochemical behaviors of co-deposited Pb/PbMnO2 composite anode in sulfuric acid solution Tafel and EIS investigations  

Science Journals Connector (OSTI)

The oxygen evolution kinetics and anodic layer properties of Pb/PbMnO2 composite anode during the 72h galvanostatic electrolysis in H2SO4 solution were investigated with Quasi-stationary polarization (Tafel) and Electrochemical Impedance Spectroscopy (EIS) techniques. The results revealed that the anodic activity and reaction kinetics varied a lot during the electrolysis for it is a process indicating the formation and stabilization of anodic layer. At the very beginning of electrolysis, the composite anode exhibited very high oxygen evolution activity since the reaction was controlled by the transformation step of intermediates. Then, its oxygen evolution activity was largely diminished and the rate determination step (rds) became the formation and adsorption of first intermediate, SOHads. In the prolonged electrolysis, the anodic potential gradually decreased and the final stable value was comparable to industrial PbAg (1.0%) anode. On the stable anodic layer after 72h, the oxygen evolution reaction (OER) was still controlled by the formation and adsorption of intermediate, and the adsorption resistance took a dominant part in the whole impedance. Besides, compared with PbAg and Pb anode, although OER at the stable state were all controlled by the intermediate adsorption process, the adsorption resistance of Pb/PbMnO2 anode was much smaller than the other two due to the existence of MnO2 particles and large amount of ?-PbO2 in the stable anodic layer.

Yanqing Lai; Yuan Li; Liangxing Jiang; Wang Xu; Xiaojun Lv; Jie Li; Yexiang Liu

2012-01-01T23:59:59.000Z

186

Oxygen Transport Membranes  

SciTech Connect

The focus of this research was to develop new membrane materials by synthesizing different compounds and determining their defect structures, crystallographic structures and electrical properties. In addition to measuring electrical conductivity, oxygen vacancy concentration was also evaluated using thermogravimetry, Neutron diffraction and Moessbauer Spectroscopy. The reducing conditions (CO{sub 2}/CO/H{sub 2} gas mixtures with steam) as encountered in a reactor environment can be expected to have significant influence on the mechanical properties of the oxides membranes. Various La based materials with and without Ti were selected as candidate membrane materials for OTM. The maximum electrical conductivity of LSF in air as a function of temperature was achieved at < 600 C and depends on the concentration of Sr (acceptor dopant). Oxygen occupancy in LSF was estimated using Neutron diffractometry and Moessbauer Spectroscopy by measuring magnetic moment changes depending on the Fe{sup 3+} and Fe{sup 4+} ratio. After extensive studies of candidate materials, lanthanum ferrites (LSF and LSFT) were selected as the favored materials for the oxygen transport membrane (OTM). LSF is a very good material for an OTM because of its high electronic and oxygen ionic conductivity if long term stability and mechanical strength are improved. LSFT not only exhibits p-type behavior in the high oxygen activity regime, but also has n-type conduction in reducing atmospheres. Higher concentrations of oxygen vacancies in the low oxygen activity regime may improve the performance of LSFT as an OTM. The hole concentration is related to the difference in the acceptor and donor concentration by the relation p = [Sr'{sub La}]-[Ti{sm_bullet}{sub Fe}]. The chemical formulation predicts that the hole concentration is, p = 0.8-0.45 or 0.35. Experimental measurements indicated that p is about {approx} 0.35. The activation energy of conduction is 0.2 eV which implies that LSCF conducts via the small polaron conduction mechanism. Scanning transmission electron microscopy (STEM) and electron energy loss spectroscopy (EELS) were used to develop strategies to detect and characterize vacancy creation, dopant segregations and defect association in the oxygen conducting membrane material. The pO{sub 2} and temperature dependence of the conductivity, non-stoichiometry and thermal-expansion behavior of compositions with increasing complexity of substitution on the perovskite A and B sites were studied. Studies with the perovskite structure show anomalous behavior at low oxygen partial pressures (<10{sup -5} atm). The anomalies are due to non-equilibrium effects and can be avoided by using very strict criteria for the attainment of equilibrium. The slowness of the oxygen equilibration kinetics arises from two different mechanisms. In the first, a two phase region occurs between an oxygen vacancy ordered phase such as brownmillerite SrFeO{sub 2.5} and perovskite SrFeO{sub 3-x}. The slow kinetics is associated with crossing the two phase region. The width of the miscibility gap decreases with increasing temperature and consequently the effect is less pronounced at higher temperature. The preferred kinetic pathway to reduction of perovskite ferrites when the vacancy concentration corresponds to the formation of significant concentrations of Fe{sup 2+} is via the formation of a Ruddlesden-Popper (RP) phases as clearly observed in the case of La{sub 0.5}Sr{sub 0.5}FeO{sub 3-x} where LaSrFeO{sub 4} is found together with Fe. In more complex compositions, such as LSFTO, iron or iron rich phases are observed locally with no evidence for the presence of discrete RP phase. Fracture strength of tubular perovskite membranes was determined in air and in reducing atmospheric conditions. The strength of the membrane decreased with temperature and severity of reducing conditions although the strength distribution (Weibull parameter, m) was relatively unaltered. Surface and volume dominated the fracture origins and the overall fracture was purely transgranular. The dual phas

S. Bandopadhyay

2008-08-30T23:59:59.000Z

187

Oxygen Transport Ceramic Membranes  

SciTech Connect

The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and studies on newer composition of Ti doped LSF. In this report, in situ neutron diffraction was used to characterize the chemical and structural properties of La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} (here after as L2SF55T) specimen, which was subject to measurements of neutron diffraction from room temperature to 900 C. It was found that space group of R3c yielded a better refinement than a cubic structure of Pm3m. Oxygen occupancy was nearly 3 in the region from room temperature to 700 C, above which the occupancy decreased due to oxygen loss. Dense OTM bars provided by Praxair were loaded to fracture at varying stress rates. Studies were done at room temperature in air and at 1000 C in a specified environment to evaluate slow crack growth behavior. The X-Ray data and fracture mechanisms points to non-equilibrium decomposition of the LSFCO OTM membrane. The non-equilibrium conditions could probably be due to the nature of the applied stress field (stressing rates) and leads to transition in crystal structures and increased kinetics of decomposition. The formations of a Brownmillerite or Sr2Fe2O5 type structures, which are orthorhombic are attributed to the ordering of oxygen vacancies. The cubic to orthorhombic transitions leads to 2.6% increase in strains and thus residual stresses generated could influence the fracture behavior of the OTM membrane. Continued investigations on the thermodynamic properties (stability and phase-separation behavior) and total conductivity of prototype membrane materials were carried out. The data are needed together with the kinetic information to develop a complete model for the membrane transport. Previously characterization, stoichiometry and conductivity measurements for samples of La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} were reported. In this report, measurements of the chemical and thermal expansion as a function of temperature and p{sub O2} are described.

S. Bandopadhyay; N. Nagabhushana; X.-D Zhou; Q. Cai; J. Yang; W.B. Yelon; W.J. James; H.U. Anderson; Alan Jacobson; C.A. Mims

2004-05-01T23:59:59.000Z

188

Absorption process for producing oxygen and nitrogen and solution therefor  

DOE Patents (OSTI)

Process for the separation and purification of oxygen and nitrogen is disclosed which utilizes solutions of oxygen carriers to selectively absorb oxygen from a gaseous stream, leaving nitrogen as a byproduct. In the process, an oxygen carrier capable of reversibly binding molecular oxygen is dissolved in a solvent solution, which absorbs oxygen from an oxygen-containing gaseous feed stream such as atmospheric air and desorbs oxygen to a gaseous product stream. The feed stream is maintained at a sufficiently high oxygen pressure to keep the oxygen carrier in its oxygenated form during absorption, while the product stream is maintained at a sufficiently low oxygen pressure to keep the carrier in its deoxygenated form during desorption. In an alternate mode of operation, the carrier solution is maintained at a sufficiently low temperature and high oxygen pressure to keep the oxygen carrier in its oxygenated form during absorption, and at a sufficiently high temperature to keep the carrier in its deoxygenated form during desorption. Under such conditions, exceptionally high oxygen concentrations on the order of 95% to 99% are obtained, as well as a long carrier lifetime in excess of 3 months, making the process commercially feasible. 1 figure

Roman, I.C.; Baker, R.W.

1990-09-25T23:59:59.000Z

189

Absorption process for producing oxygen and nitrogen and solution therefor  

DOE Patents (OSTI)

Process for the separation and purification of oxygen and nitrogen is disclosed which utilizes solutions of oxygen carriers to selectively absorb oxygen from a gaseous stream, leaving nitrogen as a byproduct. In the process, an oxygen carrier capable of reversibly binding molecular oxygen is dissolved in a solvent solution, which absorbs oxygen from an oxygen-containing gaseous feed stream such as atmospheric air and desorbs oxygen to a gaseous product stream. The feed stream is maintained at a sufficiently high oxygen pressure to keep the oxygen carrier in its oxygenated form during absorption, while the product stream is maintained at a sufficiently low oxygen pressure to keep the carrier in its deoxygenated form during desorption. In an alternate mode of operation, the carrier solution is maintained at a sufficiently low temperature and high oxygen pressure to keep the oxygen carrier in its oxygenated form during absorption, and at a sufficiently high temperature to keep the carrier in its deoxygenated form during desorption. Under such conditions, exceptionally high oxygen concentrations on the order of 95% to 99% are obtained, as well as a long carrier lifetime in excess of 3 months, making the process commercially feasible.

Roman, Ian C. [Wilmington, DE; Baker, Richard W. [Palo Alto, CA

1990-09-25T23:59:59.000Z

190

Musical Atmospherics  

Science Journals Connector (OSTI)

... THE characteristics of audio musical atmospherics which are obtained when an ... musical atmospherics which are obtained when an audio amplifier is placed in a long line or aerial have been discussed from time to ...

T. L. ECKERSLEY

1935-01-19T23:59:59.000Z

191

On the performance and mechanisms of toluene removal by FeOx/SBA-15-assisted non-thermal plasma at atmospheric pressure and room temperature  

Science Journals Connector (OSTI)

Abstract FeOx/SBA-15 catalysts were prepared via impregnation and utilized for toluene removal in dielectric barrier discharge (DBD) plasma at atmospheric pressure and room temperature. Toluene removal was investigated in the environment of various mixed N2/O2 plasmas, showing that toluene removal efficiency and \\{COx\\} selectivity were greatly increased by FeOx/SBA-15 and that the organic intermediates were greatly reduced by catalysts. In pure N2 plasma, the bulk oxygen in the catalyst was involved in the toluene oxidation, and the 3%FeOx/SBA-15 catalyst showed the optimal toluene oxidation activity. The catalysts were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), N2 adsorptiondesorption, X-ray photoelectron spectroscopy (XPS), H2 temperature-programmed reduction (H2-TPR) and O2 temperature-programmed desorption (O2-TPD), showing that toluene oxidation was closely related to the highly dispersed nature of iron on the SBA-15 surface, the reduction temperature of Fe2+ and the oxygen adsorption ability of the catalyst. The pathways of toluene decomposition in the combination of FeOx/SBA-15 with a non-thermal plasma (NTP) system were proposed based on the identified intermediates.

Meijuan Lu; Rong Huang; Junliang Wu; Mingli Fu; Limin Chen; Daiqi Ye

2015-01-01T23:59:59.000Z

192

Characterization of Pt/SiO2 Model Catalysts at UHV and Near Atmospheric Pressures  

E-Print Network (OSTI)

catalyst samples, prepared under UHV conditions in a contiguous high pressure reactor cell surface analysis with measurements on a Pt(110) single crystal for direct com- parison. CO desorption measurements and STM measure, turnover frequency (TOF, product molecules produced/site/s) is a standard metric used for comparison

Goodman, Wayne

193

Modeling Terrestrial Biogenic Sources of Oxygenated Organic Emissions  

Science Journals Connector (OSTI)

In recent years, oxygenated volatile organic chemicals (OVOCs) likeacetone have been recognized as important atmospheric constituents due to their ability to sequester reactive nitrogen in the form peroxyacetyl nitrate (PAN) and to be a source ...

Christopher Potter; Steven Klooster; David Bubenheim; Hanwant B. Singh; Ranga Myneni

2003-07-01T23:59:59.000Z

194

Structure of rings in vitreous SiO2  

Science Journals Connector (OSTI)

The structure of n-fold rings in vitreous SiO2 is investigated using molecular-dynamics configurations. A recently developed interaction potential for SiO2 consisting of long-range Coulomb interactions, the effect of electronic polarizability, and three-body covalent forces is used in the molecular-dynamics study of the vitreous state. Results for the statistics of rings and distribution of interatomic distances and bond angles in the rings are presented for the vitreous state. The statistics of rings for the molten state is also discussed.

Jos P. Rino; Ingvar Ebbsj; Rajiv K. Kalia; Aiichiro Nakano; Priya Vashishta

1993-02-01T23:59:59.000Z

195

Oxygen Transport Ceramic Membranes  

SciTech Connect

Ti doping on La{sub 1-x}Sr{sub x}FeO{sub 3-{delta}} (LSF) tends to increase the oxygen equilibration kinetics of LSF in lower oxygen activity environment because of the high valence state of Ti. However, the addition of Ti decreases the total conductivity because the acceptor ([Sr{prime}{sub La}]) is compensated by the donor ([Ti{sub Fe}{sup {sm_bullet}}]) which decreases the carrier concentration. The properties of La{sub 0.2}Sr{sub 0.8}Fe{sub 1-x}Ti{sub x}O{sub 3-{delta}} (LSFT, x = 0.45) have been experimentally and theoretically investigated to elucidate (1) the dependence of oxygen occupancy and electrochemical properties on temperature and oxygen activity by thermogravimetric analysis (TGA) and (2) the electrical conductivity and carrier concentration by Seebeck coefficient and electrical measurements. In the present study, dual phase (La{sub 0.2}Sr{sub 0.8}Fe{sub 0.6}Ti{sub 0.4}O{sub 3-{delta}}/Ce{sub 0.9}Gd{sub 0.1}O{sub 2-{delta}}) membranes have been evaluated for structural properties such as hardness, fracture toughness and flexural strength. The effect of high temperature and slightly reducing atmosphere on the structural properties of the membranes was studied. The flexural strength of the membrane decreases upon exposure to slightly reducing conditions at 1000 C. The as-received and post-fractured membranes were characterized using XRD, SEM and TG-DTA to understand the fracture mechanisms. Changes in structural properties of the composite were sought to be correlated with the physiochemical features of the two-phases. We have reviewed the electrical conductivity data and stoichiometry data for La{sub 0.2}Sr{sub 0.8}Cr{sub 0.2}Fe{sub 0.8}O{sub 3-{delta}} some of which was reported previously. Electrical conductivity data for La{sub 0.2}Sr{sub 0.8}Cr{sub 0.2}Fe{sub 0.8}O{sub 3-{delta}} (LSCrF) were obtained in the temperature range, 752 {approx} 1055 C and in the pO{sub 2} range, 10{sup -18} {approx} 0.5 atm. The slope of the plot of log {sigma} vs. log pO{sub 2} is {approx} 1/5 in the p-type region, pO{sub 2} = 10{sup -5} {approx} 10{sup -1} atm. The pO{sub 2} at which the p-n transition is observed increases with increasing temperature. The activation energy for ionic conduction was estimated to be 0.86 eV from an Arrhenius plot of the minimum conductivity vs. reciprocal temperature. At temperatures below 940 C, a plateau in the conductivity isotherm suggests the presence of a two-phase region. Most likely, phase separation occurs to form a mixture of a perovskite phase and an oxygen vacancy ordered phase related to brownmillerite. Additional data for the oxygen non stoichiometry are presented.

S. Bandopadhyay; T. Nithyanantham

2006-12-31T23:59:59.000Z

196

SiO2 Fracture: Chemomechanics with a Machine-Learning Hybrid QM/MM Scheme |  

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

Snapshot from a simulation of subcritical stress corrosion cracking in Snapshot from a simulation of subcritical stress corrosion cracking in silica in a wet environment, of the kind that will be carried out at the quantum mechanical level during this INCITE project. Silicon atoms are shown in grey, oxygen in red and hydrogen in white. The nanoscale mechanisms underlying stress corrosion cracking remain unclear and can only be elucidated with these kinds of non-uniform precision simulations, which will allow quantitative comparison with experiments for the first time. James Kermode, King's College London SiO2 Fracture: Chemomechanics with a Machine-Learning Hybrid QM/MM Scheme PI Name: James Kermode PI Email: King's College London Institution: james.kermode@kcl.ac.uk Allocation Program: INCITE Allocation Hours at ALCF: 125 Million

197

Changes in O2 and CO surface chemistry with increasing carbon concentration on W(100)  

SciTech Connect

It is pointed out that tungsten carbide (WC) is of interest as an important industrial catalyst. According to a proposed model, the WC surface consists of a layer of carbon atoms beneath the first layer of tungsten atoms. Stefan et al. (1985) have conducted photoemission electron spectroscopy (PES) experiments which show significant similarities in the surface chemistry and electronic structure of WC and the model surface. In the present investigation, PES is employed as a tool to study the changes in O2 and CO surface chemistry on W(100) with carbon concentration increasing from zero to that of the model surface. It was found that 1/2 monolayer of carbon was sufficient to produce a reduction in the tungsten surface peak. Attention is given to carburization of W(100), oxygen adsorption, and CO adsorption. 14 references.

Jupiter, P.J.; Viescas, A.J.; Carbone, C.; Lindau, I.; Spicer, W.E.

1985-06-01T23:59:59.000Z

198

Global climatology of abundance and solar absorption of oxygen collision complexes  

E-Print Network (OSTI)

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

Zender, Charles S.

1999-01-01T23:59:59.000Z

199

Comparison of bulk R2-zCezCuO4 with superlattice R2-zCezCuO4/SrO/NbO2/SrO/CuO2  

Science Journals Connector (OSTI)

Bulk R2-zCezCuO4 compounds superconduct for trivalent ions R=Pr, Nd, Sm, and Eu, but not for Gd or for Cm (with Th replacing Ce). R2-zCezSr2Cu2NbO10 is a natural superlattice of R2-zCezCuO4 and the layers SrO/NbO2/SrO/CuO2; it exhibits bulk superconductivity for R=Nd, Sm, Eu, and Gd, but not for R=Pr. These differences imply that the superconducting regions in the bulk and in the superlattice must be different, and not both cuprate planes. The primary superconductivity is assigned to interstitial oxygen and Nd-O layers in the bulk and to Sr-O layers in the superlattice.

Howard A. Blackstead and John D. Dow

1999-11-01T23:59:59.000Z

200

Molecular Hydrogen Formation from Proximal Glycol Pairs on TiO2...  

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

Hydrogen Formation from Proximal Glycol Pairs on TiO2(110). Molecular Hydrogen Formation from Proximal Glycol Pairs on TiO2(110). Abstract: Understanding hydrogen formation on TiO2...

Note: This page contains sample records for the topic "atmospheric oxygen o2" 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

O2Diesel Corporation formerly Dynamic Ventures | Open Energy Information  

Open Energy Info (EERE)

O2Diesel Corporation formerly Dynamic Ventures O2Diesel Corporation formerly Dynamic Ventures Jump to: navigation, search Name O2Diesel Corporation (formerly Dynamic Ventures) Place Newark, Delaware Zip 19713 Product O2Diesel Corporation has a proprietary additive made from fats and oils, which facilitates the blending of ethanol with diesel. Coordinates 44.690435°, -71.951685° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":44.690435,"lon":-71.951685,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

202

O2 microsensors for minimally invasive tissue monitoring  

Science Journals Connector (OSTI)

...range 1030 m. To further create compact systems, the O2 quenched indicator is required to be addressable by a light emitting diode (LED) and a luminescent life- time of greater than 1 s is regarded as appropriate (Klimant et al. 1997...

2004-01-01T23:59:59.000Z

203

Atmospheric Neutrinos  

E-Print Network (OSTI)

This paper is a brief overview of the theory and experimental data of atmospheric neutrino production at the fiftieth anniversary of the experimental discovery of neutrinos.

Thomas K. Gaisser

2006-12-11T23:59:59.000Z

204

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect

Conversion of natural gas to liquid fuels and chemicals is a major goal for the Nation as it enters the 21st Century. Technically robust and economically viable processes are needed to capture the value of the vast reserves of natural gas on Alaska's North Slope, and wean the Nation from dependence on foreign petroleum sources. Technologies that are emerging to fulfill this need are all based syngas as an intermediate. Syngas (a mixture of hydrogen and carbon monoxide) is a fundamental building block from which chemicals and fuels can be derived. Lower cost syngas translates directly into more cost-competitive fuels and chemicals. The currently practiced commercial technology for making syngas is either steam methane reforming (SMR) or a two-step process involving cryogenic oxygen separation followed by natural gas partial oxidation (POX). These high-energy, capital-intensive processes do not always produce syngas at a cost that makes its derivatives competitive with current petroleum-based fuels and chemicals. This project has the following 6 main tasks: Task 1--Design, fabricate and evaluate ceramic to metal seals based on graded ceramic powder/metal braze joints. Task 2--Evaluate the effect of defect configuration on ceramic membrane conductivity and long term chemical and structural stability. Task 3--Determine materials mechanical properties under conditions of high temperatures and reactive atmospheres. Task 4--Evaluate phase stability and thermal expansion of candidate perovskite membranes and develop techniques to support these materials on porous metal structures. Task 5--Assess the microstructure of membrane materials to evaluate the effects of vacancy-impurity association, defect clusters, and vacancy-dopant association on the membrane performance and stability. Task 6--Measure kinetics of oxygen uptake and transport in ceramic membrane materials under commercially relevant conditions using isotope labeling techniques.

Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

2001-12-01T23:59:59.000Z

205

Methane Combustion over Pd/ZrO2/SiC, Pd/CeO2/SiC, Pd/Zr0.5Ce0.5O2/SiC Catalysts  

E-Print Network (OSTI)

1 Methane Combustion over Pd/ZrO2/SiC, Pd/CeO2/SiC, Pd/Zr0.5Ce0.5O2/SiC Catalysts Xiaoning Guo a Laboratory of Coal Conversion, Institute of Coal Chemistry, Taiyuan 030001, PR China b GREMI UMR6606 CNRS0.5O2 solid solution) modified Pd/SiC catalysts for methane combustion are studied. XRD and XPS

Paris-Sud XI, Université de

206

Oxygen tolerance of an in silico-designed bioinspired hydrogen-evolving catalyst in water  

Science Journals Connector (OSTI)

...highly exothermic. The overall free-energy reduction is 113.9 kcal/mol for the combined O 2...overpotential for oxygen reduction at a fuel-cell cathode . J Phys Chem B 108 : 17886...Overpotential for Oxygen Reduction at a Fuel-Cell cathode. J. Phys Chem B 108...

Patrick H.-L. Sit; Roberto Car; Morrel H. Cohen; Annabella Selloni

2013-01-01T23:59:59.000Z

207

Alkaline Microfluidic Hydrogen-Oxygen Fuel Cell as a Cathode Characterization Platform  

E-Print Network (OSTI)

Alkaline Microfluidic Hydrogen-Oxygen Fuel Cell as a Cathode Characterization Platform Fikile R of hydrogen H2 and oxygen O2 . Operating fuel cells in alkaline media, as opposed to acidic media, has on an alkaline microfluidic fuel cell for catalyst and electrode characterization. Its constantly refreshing

Kenis, Paul J. A.

208

15N2 formation and fast oxygen isotope exchange during pulsed...  

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

N2 formation and fast oxygen isotope exchange during pulsed 15N18O exposure of MnOxCeO2. 15N2 formation and fast oxygen isotope exchange during pulsed 15N18O exposure of MnOx...

209

Oxygen Transport Ceramic Membranes  

SciTech Connect

The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and studies on newer composition of Ti doped LSF. In the current research, the electrical conductivity and Seebeck coefficient were measured as a function of temperature in air. Based on these measurements, the charge carrier concentration, net acceptor dopant concentration, activation energy of conduction and mobility were estimated. The studies on the fracture toughness of the LSFT and dual phase membranes at room temperature have been completed and reported previously. The membranes that are exposed to high temperatures at an inert and a reactive atmosphere undergo many structural and chemical changes which affects the mechanical properties. To study the effect of temperature on the membranes when exposed to an inert environment, the membranes (LAFT and Dual phase) were heat treated at 1000 C in air and N{sub 2} atmosphere and hardness and fracture toughness of the membranes were studied after the treatment. The indentation method was used to find the fracture toughness and the effect of the heat treatment on the mechanical properties of the membranes. Further results on the investigation of the origin of the slow kinetics on reduction of ferrites have been obtained. The slow kinetics appears to be related to a non-equilibrium reduction pathway that initially results in the formation of iron particles. At long times, equilibrium can be reestablished with recovery of the perovskite phase. 2-D modeling of oxygen movement has been undertaken in order to fit isotope data. The model will serve to study ''frozen'' profiles in patterned or composite membranes.

S. Bandopadhyay; T. Nithyanantham; X.-D Zhou; Y-W. Sin; H.U. Anderson; Alan Jacobson; C.A. Mims

2005-11-01T23:59:59.000Z

210

Hydrogen production by steam reforming of LNG over Ni/Al2O3-ZrO2 catalysts: Effect of ZrO2 and preparation method of Al2O3-ZrO2  

Science Journals Connector (OSTI)

An Al2O3-ZrO2 support was prepared by grafting a zirconium precursor onto the surface of commercial ?-Al2O3. A physical mixture of Al2O3-ZrO2 was also prepared for the purpose of comparison. Ni/Al2O3-ZrO2 catalys...

Jeong Gil Seo; Min Hye Youn; Sunyoung Park

2008-01-01T23:59:59.000Z

211

Phase Equilibria in Synthetic CoalPetcoke Slags (Al2O3CaOFeOSiO2V2O3) under Simulated Gasification Conditions  

Science Journals Connector (OSTI)

Phase Equilibria in Synthetic CoalPetcoke Slags (Al2O3CaOFeOSiO2V2O3) under Simulated Gasification Conditions ... Phase equilibria of the Al2O3CaOFeOSiO2V2O3 system in synthetic slag mixtures simulating coalpetcoke slag chemistry at 1500 C in an oxygen partial pressure of 108 atm were investigated by a series of quench experiments. ... Petroleum coke or petcoke is a waste product of petroleum refining and is an attractive feedstock alternative for carbon. ...

Jinichiro Nakano; Kyei-Sing Kwong; James Bennett; Thomas Lam; Laura Fernandez; Piyamanee Komolwit; Seetharaman Sridhar

2011-06-17T23:59:59.000Z

212

Removal of pharmaceutical and personal care products (PPCPs) pollutants from water by novel TiO2Coconut Shell Powder (TCNSP) composite  

Science Journals Connector (OSTI)

Abstract Photocatlytic removal of three pharmaceutical and personal care products pollutants using novel TiO2Coconut Shell Powder (TCNSP) composite was investigated. The photocatalytic degradation rate of \\{PPCPs\\} generally increased with increasing light intensity and dissolved oxygen concentration. The degradation rate decreased with increasing initial concentration of PPCPs. The \\{PPCPs\\} concentration decreased substantially under irradiation of UVC when used in conjunction with the TCNSP composite. A number of composite/radiation types and intensities were tested. The concentration rate decrease trend was as: UVC/TCNSP>UVA/TCNSP>UVC>UVA. Under the UVC/TCNP combination, 99% removal was achieved compared to 30% for TiO2.

Majeda Khraisheh; Jongkyu Kim; Luiza Campos; Alaa H. Al-Muhtaseb; Alaa Al-Hawari; Mohammad Al Ghouti; Gavin M. Walker

2014-01-01T23:59:59.000Z

213

Oxygen-related dielectric relaxation and leakage characteristics of Pt,,Ba,Sr...TiO3 Pt thin-film capacitors  

E-Print Network (OSTI)

Oxygen-related dielectric relaxation and leakage characteristics of Pt?,,Ba,Sr...TiO3 ?Pt thin to the postannealing temperature in oxygen and nitrogen atmosphere. High leakage currents and low-frequency dielectric and subsequently annealed in oxygen at 350 °C. Such results are related to the mobile oxygen ions and oxygen

Cao, Wenwu

214

C/O RATIO AS A DIMENSION FOR CHARACTERIZING EXOPLANETARY ATMOSPHERES  

SciTech Connect

Until recently, infrared observations of exoplanetary atmospheres have typically been interpreted using models that assumed solar elemental abundances. With the chemical composition fixed, attempts have been made to classify hot Jupiter atmospheres on the basis of stellar irradiation. However, recent observations have revealed deviations from predictions based on such classification schemes, and chemical compositions retrieved from some data sets have also indicated non-solar abundances. The data require a two-dimensional (2D) characterization scheme with dependence on both irradiation and chemistry. In this work, we suggest the carbon-to-oxygen (C/O) ratio as an important second dimension for characterizing exoplanetary atmospheres. In hot-hydrogen-dominated atmospheres, the C/O ratio critically influences the relative concentrations of several spectroscopically dominant species. Between a C/O of 0.5 (solar value) and 2, the H{sub 2}O and CH{sub 4} abundances can vary by several orders of magnitude in the observable atmosphere, and new hydrocarbon species such as HCN and C{sub 2}H{sub 2} become prominent for C/O {>=} 1, while the CO abundance remains almost unchanged. Furthermore, a C/O {>=} 1 can preclude a strong thermal inversion due to TiO and VO in a hot Jupiter atmosphere, since TiO and VO are naturally underabundant for C/O {>=} 1. We, therefore, suggest a new 2D classification scheme for hydrogen-dominated exoplanetary atmospheres with irradiation (or temperature) and C/O ratio as the two dimensions. We define four classes in this 2D space (O1, O2, C1, and C2) with distinct chemical, thermal, and spectral properties. Based on the most recent observations, we characterize the thermal structure and C/O ratios of six hot Jupiters (XO-1b, CoRoT-2b, WASP-14b, WASP-19b, WASP-33b, and WASP-12b) in the framework of our proposed 2D classification scheme. While the data for several systems in our sample are consistent with C-rich atmospheres, new observations are required to conclusively constrain their C/O ratios in the day side as well as the terminator regions of their atmospheres. We discuss how observations using existing and forthcoming facilities can constrain C/O ratios in exoplanetary atmospheres.

Madhusudhan, Nikku, E-mail: Nikku.Madhusudhan@yale.edu [Department of Physics, Yale University, New Haven, CT 06511 (United States); Department of Astronomy, Yale University, New Haven, CT 06511 (United States)

2012-10-10T23:59:59.000Z

215

Electron-impact excitation of neutral oxygen  

E-Print Network (OSTI)

Aims: To calculate transition rates from ground and excited states in neutral oxygen atoms due to electron collisions for non-LTE modelling of oxygen in late-type stellar atmospheres, thus enabling reliable interpretation of oxygen lines in stellar spectra. Methods: A 38-state R-matrix calculation in LS-coupling has been performed. Basis orbitals from the literature (Thomas et al.) are adopted, and a large set of configurations are included to obtain good representations of the target wavefunctions. Rate coefficients are calculated by averaging over a Maxwellian velocity distribution. Results: Estimates for the cross sections and rate coefficients are presented for transitions between the seven lowest LS states of neutral oxygen. The cross sections for excitation from the ground state compare well with existing experimental and recent theoretical results.

P. S. Barklem

2006-09-25T23:59:59.000Z

216

CANMET CO2 Consortium - O2/CO2 Recycle Combustion  

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

CANMET CO CANMET CO 2 Consortium - O 2 /CO 2 Recycle Combustion Background The mission of the U.S. Department of Energy/National Energy Technology Laboratory (DOE/NETL) Existing Plants, Emissions & Capture (EPEC) Research & Development (R&D) Program is to develop innovative environmental control technologies to enable full use of the nation's vast coal reserves, while at the same time allowing the current fleet of coal-fired power plants to comply with existing and emerging environmental

217

Bond formation at the Ni/ZrO2 interface  

Science Journals Connector (OSTI)

We report on the formation of strong chemical bonds at the Ni(100)/cubic-ZrO2(100) polar interfaces. Ab initio density functional theory calculations demonstrate that both Zr/Ni and O/Ni junctions are energetically stable, and predict that two different interactions determine the interface adhesion. Our results reveal that O-Ni ionic bonds are formed by Ni electron donation, while the Zr-Ni bonds show a mixed character with ionic and electron hybridization contributions.

J. I. Beltrn; S. Gallego; J. Cerd; J. S. Moya; M. C. Muoz

2003-08-07T23:59:59.000Z

218

Solar Energy Materials & Solar Cells 87 (2005) 181196 Optical filters from SiO2 and TiO2 multi-layers  

E-Print Network (OSTI)

Solar Energy Materials & Solar Cells 87 (2005) 181­196 Optical filters from SiO2 and TiO2 multi Abstract Sol­gel spin coating process is used to produce optical filters from SiO2 and TiO2 multi- layers­19] properties. They vary according to the chosen substrate, sol, central wavelength, number of layers, optical

Thirumalai, Devarajan

219

Effect of metal oxide and oxygen on the growth of single-walled carbon nanotubes by electric arc discharge  

Science Journals Connector (OSTI)

The effect of oxygen on the growth of single-walled carbon nanotubes was studied with NiCo alloy powder as catalyst under helium atmosphere of 500Torr by electric arc discharge. The oxygen included in nickel or...

Delong He; Yongning Liu; Tingkai Zhao; Jiewu Zhu

2008-03-01T23:59:59.000Z

220

A quantum chemical study of ZrO2 atomic layer deposition growth reactions on the SiO2 surface  

E-Print Network (OSTI)

A quantum chemical study of ZrO2 atomic layer deposition growth reactions on the SiO2 surface Department, Ford Research Laboratory, Ford Motor Company, Dearborn, MI 48121, USA c Department of Chemistry to replace silicon oxide (SiO2) as the gate dielectric for future generation metal-oxide-semiconductor (MOS

Garfunkel, Eric

Note: This page contains sample records for the topic "atmospheric oxygen o2" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
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We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Potentials of Silver and Gold Electrodes of ZrO2-Based Cells in N2+ O2+ CO2+ CO Gas Mixtures  

Science Journals Connector (OSTI)

Steady-state electrode potentials in cells with a ZrO2+ 10 mol % Y2O3electrolyte are measured at 400 to 500C in nonequilibrium N2+ O2+ CO2+ CO gas mixtures containing 03 and 010 vol % of CO and O2, respectivel...

G. I. Fadeev; I. D. Remez

2001-05-01T23:59:59.000Z

222

Hydrogen (H2) Production by Oxygenic Phototrophs  

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

Production by Oxygenic Phototrophs Eric L. Hegg Michigan State University Great Lakes Bioenergy Research Center Bioresour. Technol. 2011, 102, 8589-8604 Major Challenges to H 2 Photoproduction Biological Challenges * Poor efficiency of H 2 production * Poor heterologous expression of H 2 -forming enzymes * Low quantum yields * Competition for reducing equivalents; poor electron coupling * Sensitivity of H 2 -forming enzymes to O 2 M. Ghirardi, Abstract #1751, Honolulu PRiME 2012 Technical Challenges * Mixture of H 2 and O 2 ; H 2 separation and storage * CO 2 addition and overall reactor design Overcoming Low Efficiency: Improving ET * Eliminate or down-regulate pathways competing for ele * Production of organic acids * Formation of NADPH/carbon fixation

223

Examination of oxygen uncoupling behaviour and reactivity towards methane for manganese silicate oxygen carriers in chemical-looping combustion  

Science Journals Connector (OSTI)

Abstract Cheap and environmental friendly MnSi oxygen carriers manufactured from Mn3O4 and SiO2 by spray-drying have been investigated with respect to properties for chemical-looping combustion (CLC) and chemical-looping with oxygen uncoupling (CLOU). Fifteen oxygen carriers with SiO2 content varying from 2wt% to 75wt% were prepared and calcined at 1050C and 1150C. The ability of material to release O2 and their reactivity towards CH4 were examined in the temperature range 9001100C. Particles with a SiO2 content of more than 45wt% and calcined at 1150C showed limited CLOU behaviour and poor reactivity towards CH4 at all temperatures investigated. The rest of the materials had significant CLOU properties and provided high conversion of CH4 under the experimental conditions chosen. Increasing the temperature of operation enhanced the CLOU behaviour and reactivity towards CH4. At temperatures above 950C, the CH4 conversion was 90100% for these materials. Crystalline phases identified by XRD in the oxidized samples with more than 45wt% SiO2 and calcined at 1150C were mainly rhodonite MnSiO3. For materials with SiO2 content below 45wt%, braunite Mn7SiO12 was detected as the main phase in most of the samples after oxidation. This indicates that braunite Mn7SiO12 is the main active phase for oxygen transfer in CLC and CLOU, which is supported by thermodynamic calculations. The reactivity of all of the materials were also studied with syngas (50% CO and 50% H2), showing complete gas conversion at 950C, except for materials with a SiO2 content of more than 45wt% and calcined at 1150C. The mechanical integrity and attrition resistance of the oxygen carriers were examined in a jet-cup attrition rig, and although the attrition rates varied, some reactive material showed low rates of attrition, making them very promising oxygen carrier materials for applications related to CLC and CLOU. However, measures should probably be taken to improve the crushing strength to some extent.

Dazheng Jing; Mehdi Arjmand; Tobias Mattisson; Magnus Rydn; Frans Snijkers; Henrik Leion; Anders Lyngfelt

2014-01-01T23:59:59.000Z

224

Pt4ZrO2/C cathode catalyst for improved durability in high temperature PEMFC based on H3PO4 doped PBI  

Science Journals Connector (OSTI)

In this paper, Pt4ZrO2/C was prepared and compared with commercial Pt/C (46.6wt.% TKK) in terms of the durability as cathode catalyst in a high temperature proton exchange membrane fuel cell (PEMFC) based on H3PO4 doped polybenzimidazole (PBI) by a potential sweep test. The catalysts before and after the potential sweep test were characterized by rotating disk electrode (RDE), X-ray diffraction (XRD), transmission electron microscopy (TEM) and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). After 3000cycles potential sweep test, the overall performance loss of the Pt4ZrO2/C membrane electrode assembly (MEA) was less than that of the Pt/C MEA. The RDE results demonstrated that the oxygen reduction reaction (ORR) activity of the as-prepared Pt4ZrO2/C is nearly the same as TKK-Pt/C. The XRD and TEM results showed that Pt4ZrO2/C catalyst presented higher sintering resistance than commercial Pt/C catalyst during the potential sweep test. This may be attributed to the addition of ZrO2, which acts an anchor to inhibit the adjacent platinum particles to agglomerate. The ICP-AES results of Pt4ZrO2/C cathode catalyst before and after the potential sweep test showed that the composition of Pt and Zr were very near the nominal atomic ratio of Pt:Zr, which reflected that Pt4ZrO2/C catalyst had a good stability during the potential sweep test. In brief, the preliminary results indicate that Pt4ZrO2/C catalyst is a good candidate of Pt/C catalyst in high temperature PEMFC based on H3PO4 doped PBI for achieving longer cell life-time and higher cell performance.

Gang Liu; Huamin Zhang; Yunfeng Zhai; Yu Zhang; Dongyan Xu; Zhi-gang Shao

2007-01-01T23:59:59.000Z

225

Atmospheric tritium  

SciTech Connect

Research progress for the year 1979 to 1980 are reported. Concentrations of tritiated water vapor, tritium gas and tritiated hydrocarbons in the atmosphere at selected sampling points are presented. (ACR)

Oestlund, H.G.; Mason, A.S.

1980-01-01T23:59:59.000Z

226

Covalency in Metal-Oxygen Multiple Bonds Evaluated Using Oxygen...  

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

Covalency in Metal-Oxygen Multiple Bonds Evaluated Using Oxygen K-edge Spectroscopy and Electronic Structure Theory . Covalency in Metal-Oxygen Multiple Bonds Evaluated Using...

227

The Rise of Oxygen over the Past 205 Million Years and the Evolution  

E-Print Network (OSTI)

The Rise of Oxygen over the Past 205 Million Years and the Evolution of Large Placental Mammals to the present, we modeled oxygen concentrations over the past 205 million years. Our analysis indicates that atmospheric oxygen approximately doubled over this period, with rela- tively rapid increases in the early

228

Chemical oxygen diffusion coefficient measurement by conductivity relaxation--correlation between tracer diffusion  

E-Print Network (OSTI)

Chemical oxygen diffusion coefficient measurement by conductivity relaxation--correlation between J. P., Grenier J. C., Loup J. P. ABSTRACT Chemical oxygen diusion coecient ¯(D)was measured the oxygen partial pressure in the surrounding atmosphere of the sample. The consequent evolution

Paris-Sud XI, Université de

229

Initial stages of the autocatalytic oxidation of the InAs(0 0 1)-(4 2)/c(8 2) surface by molecular oxygen  

E-Print Network (OSTI)

by molecular oxygen Jonathon B. Clemens a , Sarah R. Bishop a , Darby L. Feldwinn a,1 , Ravi Droopad b,2 simulations Scanning tunneling microscopy Chemisorption Oxidation Indium arsenide Oxygen Semi conducting) surface by molecular oxygen (O2) were studied using scanning tunneling microscopy (STM) and density

Kummel, Andrew C.

230

Oxygen Transport Ceramic Membranes  

SciTech Connect

The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and studies on newer composition of Ti doped LSF. In this report, Moessbauer spectroscopy was used to study the local environmentals of LSFT with various level of oxygen deficiency. Ionic valence state, magnetic interaction and influence of Ti on superexchange are discussed Stable crack growth studies on Dense OTM bars provided by Praxair were done at elevated temperature, pressure and elevated conditions. Post-fracture X-ray data of the OTM fractured at 1000 C in environment were refined by FullProf code and results indicate a distortion of the parent cubic perovskite to orthorhombic structure with reduced symmetry. TGA-DTA studies on the post-fracture samples also indicated residual effect arising from the thermal and stress history of the samples. An electrochemical cell has been designed and built for measurements of the Seebeck coefficient as a function of temperature and pressure. The initial measurements on La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} are reported. Neutron diffraction measurements of the same composition are in agreement with both the stoichiometry and the kinetic behavior observed in coulometric titration measurements. A series of isotope transients under air separation mode (small gradient) were completed on the membrane of LSCrF-2828 at 900 C. Low pO{sub 2} atmospheres based on with CO-CO{sub 2} mixtures have also been admitted to the delivery side of the LSCrF-2828 membrane to produce the gradients which exist under syngas generation conditions. The COCO{sub 2} mixtures have normal isotopic {sup 18}O abundances. The evolution of {sup 18}O on the delivery side in these experiments after an {sup 18}O pulse on the air side reveals a wealth of information about the oxygen transport processes.

S. Bandopadhyay; N. Nagabhushana; X.-D Zhou; Q. Cai; J. Yang; W.B. Yelon; W.J. James; H.U. Anderson; Alan Jacobson; C.A. Mims

2004-10-01T23:59:59.000Z

231

Oxygen enriched fireflooding  

SciTech Connect

Both pure oxygen and enriched air have been considered in fireflooding for enhanced oil recovery. Laboratory and field testing have conclusively shown that oxygen is practical and cost effective for this application. For reservoirs that require a large volume of high pressure gas, oxygen is cheaper than air simply based on compression costs. Additional process benefits with oxygen include: Faster Oil Production; Lower Injection Pressure; Greater Well Spacing; Increased Carbon Dioxide Partial Pressure; Lower Gas-to-Oil Ratios; and Purer Produced Gas. These features provide a compelling case for oxygen, once the safety and materials compatibility issues are properly addressed.

Shahani, G.H.; Gunardson, H.H. [Air Products and Chemicals, Allentown, PA (United States)

1995-02-01T23:59:59.000Z

232

Surface Modification by Atmospheric Pressure Plasma for Improved Bonding.  

E-Print Network (OSTI)

??An atmospheric pressure plasma source operating at temperatures below 150C and fed with 1.0-3.0 volume% oxygen in helium was used to activate the surfaces of (more)

Williams, Thomas Scott

2013-01-01T23:59:59.000Z

233

Sliding discharges in steam: effects of dielectric surface and hydrocarbon additives on hydrogen, oxygen and hydrogen peroxide generation  

Science Journals Connector (OSTI)

A sliding surface discharge was formed on a dielectric layer in steam at ~100C and atmospheric pressure. The material properties and the thickness of the dielectric layer were found to strongly affect the energy deposition into the plasma. With a 0.32cm thick dielectric the energy deposition was 1.4 times greater than with a 0.48cm thick dielectric, and with window glass it was 1.3 times greater than with Macor of the same thickness. Product gases were H2 (734%) and O2 (271%), and H2O2 accumulated in the condensed water up to 0.4gl?1. The energy yield for hydrogen was 1.20.1g H2kWh?1 and independent of the input power and thickness or material of the dielectric. However, for hydrogen peroxide the energy yield, which varied between 0.61 and 3.2g H2O2kWh?1, was found to depend strongly on the thickness and material of the dielectric. The addition of benzene to the steam increased the energy efficiency of hydrogen to 2.3gkWh?1, and decreased oxygen and hydrogen peroxide by about 3 and 6 times, respectively. It also caused the deposition of phenol and polymer-like layers on the dielectric. The results are explained on the basis of reactions of H and OH radicals adsorbed on the surface and/or in gas phase.

Muhammad Arif Malik; Karl H Schoenbach

2013-01-01T23:59:59.000Z

234

A novel hierarchical homogeneous nanoarchitecture of TiO2 nanosheets branched TiO2 nanosheet arrays for high efficiency dye-sensitized solar cells  

Science Journals Connector (OSTI)

Abstract We report a novel hierarchical homogeneous nanoarchitecture of TiO2 nanosheets branched TiO2 nanosheet arrays, which is formed directly on transparent conductive fluorine-doped tin oxide (FTO) glass substrate through a one-step facile hydrothermal reaction without the use of a seed layer. The hierarchical homogeneous nanoarchitecture is composed of long TiO2 nanosheet trunks grafted with a large number of TiO2 nanosheet branches, which is an effective structure to improve the charge transport with the increase of the specific surface area. Dye-sensitized solar cell (DSSC) based on TiO2 nanosheets branched TiO2 nanosheet arrays can achieve an outstanding power conversion efficiency of 6.66%, which is attributed to the specific performances such as higher specific surface area for adsorbing more dye molecules, superior light scattering capacity for boosting the light-harvesting efficiency and faster charge transport for efficient charge collection.

Bing-Xin Lei; Xiao-Feng Zheng; He-kang Qiao; Yi Li; Shu-Nuo Wang; Guo-Lei Huang; Zhen-Fan Sun

2014-01-01T23:59:59.000Z

235

NETL: Gasification - Development of Ion-Transport Membrane Oxygen  

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

Feed Systems Feed Systems Recovery Act: Development of Ion-Transport Membrane Oxygen Technology for Integration in IGCC and Other Advanced Power Generation Systems Air Products and Chemicals, Inc. Project Number: FC26-98FT40343 Project Description Air Products and Chemicals, Inc. is developing, scaling-up, and demonstrating a novel air separation technology for large-scale production of oxygen (O2) at costs that are approximately one-third lower than conventional cryogenic plants. An Ion Transport Membrane (ITM) Oxygen plant co-produces power and oxygen. A phased technology RD&D effort is underway to demonstrate all necessary technical and economic requirements for scale-up and industrial commercialization. The ITM Oxygen production technology is a radically different approach to producing high-quality tonnage oxygen and to enhance the performance of integrated gasification combined cycle and other advanced power generation systems. Instead of cooling air to cryogenic temperatures, oxygen is extracted from air at temperatures synergistic with power production operations. Process engineering and economic evaluations of integrated gasification combined cycle (IGCC) power plants comparing ITM Oxygen with a state-of-the-art cryogenic air separation unit are aimed to show that the installed capital cost of the air separation unit and the installed capital of IGCC facility are significantly lower compared to conventional technologies, while improving power plant output and efficiency. The use of low-cost oxygen in combustion processes would provide cost-effective emission reduction and carbon management opportunities. ITM Oxygen is an enabling module for future plants for producing coal derived shifted synthesis gas (a mixture of hydrogen [H2] and carbon dioxide [CO2]) ultimately for producing clean energy and fuels. Oxygen-intensive industries such as steel, glass, non-ferrous metallurgy, refineries, and pulp and paper may also realize cost and productivity benefits as a result of employing ITM Oxygen.

236

A Simple Oxygen Detector Using ZincAir Battery  

Science Journals Connector (OSTI)

Elementary/Middle School Science; High School/Introductory Chemistry; Demonstrations; Hands-On Learning/Manipulatives; Gases; Laboratory Equipment/Apparatus ... Therefore, Faradays law can be confirmed by measuring the change in the volume of O2 consumed or the gained mass of the zincair battery with increasing quantity of electricity in a circuit using the zincair battery as the power source. ... (2-4) At the operating voltage of the zincair battery (1.4 V), the electric current in a circuit, with a small resistance, linearly changes with respect to the atmospheric O2 concentration. ...

Yoong Kin Hooi; Masayoshi Nakano; Nobuyoshi Koga

2013-12-24T23:59:59.000Z

237

Oxygen ion conducting materials  

DOE Patents (OSTI)

An oxygen ion conducting ceramic oxide that has applications in industry including fuel cells, oxygen pumps, oxygen sensors, and separation membranes. The material is based on the idea that substituting a dopant into the host perovskite lattice of (La,Sr)MnO.sub.3 that prefers a coordination number lower than 6 will induce oxygen ion vacancies to form in the lattice. Because the oxygen ion conductivity of (La,Sr)MnO.sub.3 is low over a very large temperature range, the material exhibits a high overpotential when used. The inclusion of oxygen vacancies into the lattice by doping the material has been found to maintain the desirable properties of (La,Sr)MnO.sub.3, while significantly decreasing the experimentally observed overpotential.

Vaughey, John (Elmhurst, IL); Krumpelt, Michael (Naperville, IL); Wang, Xiaoping (Downers Grove, IL); Carter, J. David (Bolingbrook, IL)

2003-01-01T23:59:59.000Z

238

Ethanol synthesis from syngas over Rh-based/SiO2 catalysts: A...  

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

over Rh-basedSiO2 catalysts: A combined experimental and theoretical modeling study. Ethanol synthesis from syngas over Rh-basedSiO2 catalysts: A combined experimental and...

239

Investigation of the Rechargeability of Li-O2 Batteries in Non...  

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the Rechargeability of Li-O2 Batteries in Non-aqueous Electrolyte. Investigation of the Rechargeability of Li-O2 Batteries in Non-aqueous Electrolyte. Abstract: In order to...

240

Effects of electrolyte salts on the performance of Li-O2 batteries...  

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

electrolyte salts on the performance of Li-O2 batteries. Effects of electrolyte salts on the performance of Li-O2 batteries. Abstract: It is well known that the stability of...

Note: This page contains sample records for the topic "atmospheric oxygen o2" 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

The Synthesis of Ag-Doped Mesoporous TiO2 . | EMSL  

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

The Synthesis of Ag-Doped Mesoporous TiO2 . The Synthesis of Ag-Doped Mesoporous TiO2 . Abstract: Ag-doped mesoporous titanium oxide was prepared using non-ionic surfactants and...

242

The Synthesis of Cadmium Doped Mesoporous TiO2. | EMSL  

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The Synthesis of Cadmium Doped Mesoporous TiO2. The Synthesis of Cadmium Doped Mesoporous TiO2. Abstract: Cd doped mesoporous titanium oxide was prepared using non-ionic...

243

Self-assembled TiO2-Graphene Hybrid Nanostructures for Enhanced...  

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TiO2-Graphene Hybrid Nanostructures for Enhanced Li-ion Insertion . Self-assembled TiO2-Graphene Hybrid Nanostructures for Enhanced Li-ion Insertion . Abstract: We used anionic...

244

Formaldehyde Polymerization on (WO3)3/TiO2(110) Model Catalyst...  

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

Formaldehyde Polymerization on (WO3)3TiO2(110) Model Catalyst. Formaldehyde Polymerization on (WO3)3TiO2(110) Model Catalyst. Abstract: Polymerization of formaldehyde, H2CO, was...

245

Oxidative Dissolution Potential of Biogenic and Abiogenic TcO2...  

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Potential of Biogenic and Abiogenic TcO2 in Subsurface Sediments. Oxidative Dissolution Potential of Biogenic and Abiogenic TcO2 in Subsurface Sediments. Abstract: Technetium-99...

246

Imaging Adsorbate O-H Bond Cleavage: Methanol on TiO2(110). ...  

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Adsorbate O-H Bond Cleavage: Methanol on TiO2(110). Imaging Adsorbate O-H Bond Cleavage: Methanol on TiO2(110). Abstract: We investigated methanol adsorption and dissociation on...

247

SiO2 Fracture: Chemomechanics with a Machine Learning Hybrid...  

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SiO2 Fracture: Chemomechanics with a Machine Learning Hybrid QMMM Scheme SiO2 Fracture: Chemomechanics with a Machine Learning Hybrid QMMM Scheme. Close-up of a crack tip in a...

248

Optical Absorption, Stability and Structure of NpO2+ Complexes with Dicarboxylic Acids  

E-Print Network (OSTI)

Np(V)/IDA complex, the absorption band still shows, but theOptical Absorption, Stability and Structure of NpO 2+and the intensity of the absorption band of NpO 2+ at 980 nm

Guoxin Tian; Linfeng Rao

2006-01-01T23:59:59.000Z

249

TiO2 Nanoparticles as a Soft X-ray Molecular Probe  

E-Print Network (OSTI)

Figure 1. TEM image of PAA coated TiO 2 nanoparticles .TOPO with polyacrylic acid (PAA) . Preparation of TiO 2 -TOPO with polyacrylic acid (PAA) 2 . A solution of 0.1 g PAA

Ashcroft, Jared M.

2008-01-01T23:59:59.000Z

250

Acetone Chemistry on Oxidized and Reduced TiO2(110). | EMSL  

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Acetone Chemistry on Oxidized and Reduced TiO2(110). Acetone Chemistry on Oxidized and Reduced TiO2(110). Abstract: The chemistry of acetone on the oxidized and reduced surfaces of...

251

Methylene Bromide Chemistry and Photochemistry on Rutile TiO2...  

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Methylene Bromide Chemistry and Photochemistry on Rutile TiO2(110). Methylene Bromide Chemistry and Photochemistry on Rutile TiO2(110). Abstract: The chemistry and photochemistry...

252

Alcohol Chemistry on Rutile TiO2(110): The Influence of Alkyl...  

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

Alcohol Chemistry on Rutile TiO2(110): The Influence of Alkyl Substituents on Reactivity and Selectivity. Alcohol Chemistry on Rutile TiO2(110): The Influence of Alkyl Substituents...

253

Surface Chemistry of 2-Propanol on TiO2(110): Low and High Temperature...  

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

Chemistry of 2-Propanol on TiO2(110): Low and High Temperature Dehydration, Isotope Effects, and Influence of Local Surface Chemistry of 2-Propanol on TiO2(110): Low and High...

254

OH Group Dynamics of 1, 3-propanediol on TiO2(110)  

SciTech Connect

Variable-temperature scanning tunneling microscopy and dispersion-corrected density functional theory were employed to study the interaction of 1,3 propanediol with reduced TiO2(110) surfaces. We find that at 300 K, 1,3-propanediol molecules dissociate via O-H bond scission of one of the OH groups on bridge-bonded oxygen (Ob) vacancy (VO) defects forming pairs of monoalkoxide (Ob-(CH2)3-OH) and bridge-bonded bonded hydroxyl (HOb) species. The OH group of the monoalkoxide species is bound to the adjacent 5-coordinated Ti4+ (Ti5c) sites. The Ob-(CH2)3-OH species are observed to rotate around their Ob anchor, switching the position of the OH between the two adjacent Ti5c rows. The rotating species are found to assist the cross-Ob row HOb hydrogen transfer. The OH group of the monoalkoxide species is further observed to dissociate forming bidentate type dioxo (Ob-(CH2)3-"O" _(?"Ti" ?_"5c" )) species and an additional HOb. The reversible interconversion between the mono- and di-oxo species illustrates a formation of the equilibrium between these conjugate acid/base pairs.

Zhang, Zhenrong; Yoon, Yeohoon; Lin, Xiao; Acharya, Danda P.; Kay, Bruce D.; Rousseau, Roger J.; Dohnalek, Zdenek

2012-11-15T23:59:59.000Z

255

Comment on "Structure and dynamics of liquid water on rutile TiO2(110)  

SciTech Connect

Liu and co-workers [Phys. Rev. B 82, 161415 (2010)] discussed the long-standing debate regarding whether H2O molecules on the defect-free (110) surface of rutile ( -TiO2) sorb associatively, or there is dissociation of some or all first-layer water to produce hydroxyl surface sites. They conducted static density functional theory (DFT) and DFT molecular dynamics (DFT-MD) investigations using a range of cell configurations and functionals. We have reproduced their static DFT calculations of the influence of crystal slab thickness on water sorption energies. However, we disagree with several assertions made by these authors: (a) that second-layer water structuring and hydrogen bonding to surface oxygens and adsorbed water molecules are weak ; (b) that translational diffusion of water molecules in direct contact with the surface approaches that of bulk liquid water; and (c) that there is no dissociation of adsorbed water at this surface in contact with liquid water. These assertions directly contradict our publishedwork, which compared synchrotron x-ray crystal truncation rod, second harmonic generation, quasielastic neutron scattering, surface charge titration, and classical MD simulations of rutile (110) single-crystal surfaces and (110)-dominated powders in contact with bulk water, and (110)-dominated rutile nanoparticles with several monolayers of adsorbed water.

Wesolowski, David J [ORNL; Sofo, Jorge O. [Pennsylvania State University; Bandura, Andrei V. [St. Petersburg State University, St. Petersburg, Russia; Zhang, Zhan [Argonne National Laboratory (ANL); Mamontov, Eugene [ORNL; Predota, M. [University of South Bohemia, Czech Republic; Kumar, Nitin [ORNL; Kubicki, James D. [Pennsylvania State University; Kent, Paul R [ORNL; Vlcek, Lukas [ORNL; Machesky, Michael L. [Illinois State Water Survey, Champaign, IL; Fenter, Paul [Argonne National Laboratory (ANL); Cummings, Peter T [ORNL; Anovitz, Lawrence {Larry} M [ORNL; Skelton, A A [Vanderbilt University; Rosenqvist, Jorgen K [ORNL

2012-01-01T23:59:59.000Z

256

Assessment of the O2Diesel Operational Safety Program: December 23, 2002 -- June 30, 2007  

SciTech Connect

This report assesses O2Diesel's operational safety program using its ethanol-diesel blended fuel product.

TIAX LLC

2006-06-01T23:59:59.000Z

257

Epitaxial oxygen sponges as low temperature catalysts | ornl.gov  

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

Functional Materials for Energy Functional Materials for Energy Epitaxial oxygen sponges as low temperature catalysts September 10, 2013 Crystal structure of SrCoO2.5 superimposed on a scanning transmission electron microscopy image of an epitaxially stabilized oxygen sponge. Fast and reversible redox reactions at considerably reduced temperatures are achieved by epitaxial stabilization of multivalent transition metal oxides. This illustrates the unprecedented potential of complex oxides for oxide-ionics, where oxidation state changes are used for energy generation, storage and electrochemical sensing. Thermomechanical degradation reduces the overall performance and lifetime of many perovskite oxides undergoing reversible redox reactions, such as those found in solid oxide fuel cells, rechargeable batteries,

258

Spectral signatures of photosynthesis II: coevolution with other stars and the atmosphere on extrasolar worlds  

E-Print Network (OSTI)

As photosynthesis on Earth produces the primary signatures of life that can be detected astronomically at the global scale, a strong focus of the search for extrasolar life will be photosynthesis, particularly photosynthesis that has evolved with a different parent star. We take planetary atmospheric compositions simulated by Segura, et al. (2003, 2005) for Earth-like planets around observed F2V and K2V stars, modeled M1V and M5V stars, and around the active M4.5V star AD Leo; our scenarios use Earth's atmospheric composition as well as very low O2 content in case anoxygenic photosynthesis dominates. We calculate the incident spectral photon flux densities at the surface of the planet and under water. We identify bands of available photosynthetically relevant radiation and find that photosynthetic pigments on planets around F2V stars may peak in absorbance in the blue, K2V in the red-orange, and M stars in the NIR, in bands at 0.93-1.1 microns, 1.1-1.4 microns, 1.5-1.8 microns, and 1.8-2.5 microns. In addition, we calculate wavelength restrictions for underwater organisms and depths of water at which they would be protected from UV flares in the early life of M stars. We estimate the potential productivity for both surface and underwater photosynthesis, for both oxygenic and anoxygenic photosynthesis, and for hypothetical photosynthesis in which longer wavelength, multi-photosystem series are used.

Nancy Y. Kiang; Antigona Segura; Giovanna Tinetti; Govindjee; Robert E. Blankenship; Martin Cohen; Janet Siefert; David Crisp; Victoria S. Meadows

2007-01-12T23:59:59.000Z

259

Oxygen contamination in liquid Argon: combined effects on ionization electron charge and scintillation light  

E-Print Network (OSTI)

A dedicated test of the effects of Oxygen contamination in liquid Argon has been performed at the INFN-Gran Sasso Laboratory (LNGS, Italy) within the WArP R&D program. Two detectors have been used: the WArP 2.3 lt prototype and a small (0.7 lt) dedicated detector, coupled with a system for the injection of controlled amounts of gaseous Oxygen. Purpose of the test with the 0.7 lt detector is to detect the reduction of the long-lived component lifetime of the Argon scintillation light emission at increasing O2 concentration. Data from the WArP prototype are used for determining the behavior of both the ionization electron lifetime and the scintillation long-lived component lifetime during the O2-purification process activated in closed loop during the acquisition run. The electron lifetime measurements allow to infer the O2 content of the Argon and correlate it with the long-lived scintillation lifetime data. The effect of Oxygen contamination on the scintillation light has been thus measured over a wide range of O2 concentration, spanning from about 10^-3 ppm up to about 10 ppm. The rate constant of the light quenching process induced by Oxygen in LAr has been found to be k'(O2)=0.54+-0.03 micros^-1 ppm^-1.

R. Acciarri; M. Antonello; B. Baibussinov; M. Baldo-Ceolin; P. Benetti; F. Calaprice; E. Calligarich; M. Cambiaghi; N. Canci; F. Carbonara; F. Cavanna; S. Centro; A. G. Cocco; F. Di Pompeo; G. Fiorillo; C. Galbiati; V. Gallo; L. Grandi; G. Meng; I. Modena; C. Montanari; O. Palamara; L. Pandola; F. Pietropaolo; G. L. Raselli; M. Roncadelli; M. Rossella; C. Rubbia; E. Segreto; A. M. Szelc; F. Tortorici; S. Ventura; C. Vignoli

2008-04-08T23:59:59.000Z

260

Structure and Dynamics of CO2 on Rutile TiO2(110)-11....  

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

CO2 on Rutile TiO2(110)-11. Structure and Dynamics of CO2 on Rutile TiO2(110)-11. Abstract: Adsorption, binding, and diffusion of CO2 molecules on rutile TiO2(110)...

Note: This page contains sample records for the topic "atmospheric oxygen o2" 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

Electron Source in Photoinduced Hydrogen Production on Pt-Supported TiO2 Particles  

Science Journals Connector (OSTI)

Electron Source in Photoinduced Hydrogen Production on Pt-Supported TiO2 Particles ... Comment on Electron Source in Photoinduced Hydrogen Production on Pt-Supported TiO2 Particles ... Comment on Electron Source in Photoinduced Hydrogen Production on Pt-Supported TiO2 Particles ...

Toshiyuki Abe; Eiji Suzuki; Kentaro Nagoshi; Kohichi Miyashita; Masao Kaneko:

2000-03-24T23:59:59.000Z

262

CERIUM OXIDE (CeO2) PROMOTED OXYGEN CARRIER DEVELOPMENT AND SCALE MODELING STUDY FOR CHEMICAL LOOPING COMBUSTION.  

E-Print Network (OSTI)

??According to IPCC reports, the greenhouse gas CO2 is responsible for global climate change. Studies show that CO2 concentration reached a level of 400 ppm (more)

Liu, Fang

2013-01-01T23:59:59.000Z

263

Independent Component Analysis Applied to Pulse Oximetry in the Estimation of the Arterial Oxygen Saturation (SpO2)  

E-Print Network (OSTI)

and construction of small, discrete, and low-power pulse oximeter devices. 2) Digital signal processing of discreteness and long-term compat- ibility, and battery powered Light Emitting Diodes (LEDs). 3) Integration of these new technologies which typically features telehealth solutions into the established health care system

264

Fisetin attenuates hydrogen peroxide-induced cell damage by scavenging reactive oxygen species and activating protective functions of cellular glutathione system  

Science Journals Connector (OSTI)

Hydrogen peroxide (H2O2...) can induce cell damage by generating reactive oxygen species (ROS), resulting in DNA damage and cell death. The aim of this study is to elucidate the protective effects of fisetin (3,7...

Kyoung Ah Kang; Mei Jing Piao; Ki Cheon Kim

2014-01-01T23:59:59.000Z

265

Photocatalytic property of Fe3O4/SiO2/TiO2 core-shell nanoparticle with different functional layer thicknesses  

Science Journals Connector (OSTI)

This study examined the different properties of Fe3O4/SiO2/TiO2 (FST) core-shell nanoparticles encapsulated for one to five different times, represented as FST1 to FST5, respectively. These FST nanoparticles ...

Junyang Li, Libo Gao, Qiang Zhang, Ruiting Feng, Hongyan Xu, Jie Wang, Dong Sun, Chenyang Xue

2014-01-01T23:59:59.000Z

266

Heat transfer and friction factor of water based TiO2 and SiO2 nanofluids under turbulent flow in a tube  

Science Journals Connector (OSTI)

Abstract The heat transfer coefficient and friction factor of TiO2 and SiO2 water based nanofluids flowing in a circular tube under turbulent flow are investigated experimentally under constant heat flux boundary condition. TiO2 and SiO2 nanofluids with an average particle size of 50nm and 22nm respectively are used in the working fluid for volume concentrations up to 3.0%. Experiments are conducted at a bulk temperature of 30C in the turbulent Reynolds number range of 5000 to 25,000. The enhancements in viscosity and thermal conductivity of TiO2 are greater than SiO2 nanofluid. However, a maximum enhancement of 26% in heat transfer coefficients is obtained with TiO2 nanofluid at 1.0% concentration, while SiO2 nanofluid gave 33% enhancement at 3.0% concentration. The heat transfer coefficients are lower at all other concentrations. The particle concentration at which the nanofluids give maximum heat transfer has been determined and validated with property enhancement ratio. It is observed that the pressure drop is directly proportional to the density of the nanoparticle.

W.H. Azmi; K.V. Sharma; P.K. Sarma; Rizalman Mamat; G. Najafi

2014-01-01T23:59:59.000Z

267

PVP-Assisted ZrO2 coating on LiMn2O4 spinel cathode nanoparticles prepared by MnO2 nanowire templates  

E-Print Network (OSTI)

issues regarding the use of LiMn2O4 spi- nels as cathode materials is their large capacity loss observed active material. However, enhanced rate capabilities can be achieved in nanostructured materials becausePVP-Assisted ZrO2 coating on LiMn2O4 spinel cathode nanoparticles prepared by MnO2 nanowire

Cho, Jaephil

268

Fast Transporting ZnOTiO2 Coaxial Photoanodes for Dye-Sensitized Solar Cells Based on ALD-Modified SiO2 Aerogel Frameworks  

Science Journals Connector (OSTI)

To circumvent this problem, we have explored here the idea of conformally coating the silicaZnO aerogel structures with very thin layers of more robust metal oxides such as Al2O3, ZrO2, or TiO2 to create doubly coaxial structures. ... JV characteristics of DSSCs featuring 25 ?m thick aerogel-based SiO2ZnO films compared to similar films with ca. 3 and 4 coatings of Al2O3 and TiO2, respectively: (a) light performance; (b) dark performance. ... Figure 7. Plot showing the effects of increased layers of TiO2 coats over 6 nm ZnO-coated silica aerogels with respect to charge lifetimes from OCVD measurements. ...

Vennesa O. Williams; Nak Cheon Jeong; Chaiya Prasittichai; Omar K. Farha; Michael J. Pellin; Joseph T. Hupp

2012-06-21T23:59:59.000Z

269

Co-operativity among defect sites in AnO2+ and An4O9 (An = U, Np or Pu)  

SciTech Connect

Actinide dioxides derived from the AnO{sub 2} fluorite lattice are of high technological relevance due to their application in nuclear reactor fuels. Oxidation of AnO{sub 2} compounds emerges as a central theme in fuel fabrication, reactor operation, long-term storage forms for both spent fuels and surplus weapons materials, and environmental actinide migration. In this paper, we use density functional theory calculations to study the oxidation of uranium, neptunium and plutonium dioxides, AnO{sub 2} (An = U, Np or Pu), in O{sub 2} and O{sub 2}/H{sub 2}O environments. We pay particular attention to the formation of oxygen clusters (co-operativity) in AnO{sub 2+x} and how this phenomenon govern oxidation thermodynamics and the development of ordered An{sub 4}O{sub 9} compounds. The so-called split di-interstitial, which is composed of two nearest neighbor octahedral oxygen interstitials that are distorted in such a way that they dislocate one regular fluorite lattice oxygen ion to form a cluster of triangular geometry, is predicted to be the fundamental building block of the most stable cluster configurations. We also identify how the formation of oxygen defect clusters and the degree of oxidation in AnO{sub 2+x} are both governed by the characer of the An-5f to excess O-2p charger transfer, i.e. the charge transfer to the O-2p orbitals of the interstitial-like (+x) ions, and the ability of the excess O-2p orbitals to hybridize with regular fluorite lattice ions.

Andersson, Anders David [Los Alamos National Laboratory; Lezama Pacheco, Juan [Los Alamos National Laboratory; Uberuaga, Blas P [Los Alamos National Laboratory; Conradson, Steven D [Los Alamos National Laboratory

2008-01-01T23:59:59.000Z

270

Two-Dimensional Polaronic Behavior in the Binary Oxides m-HfO2 and m-ZrO2  

SciTech Connect

We demonstrate that the three-dimensional (3D) binary monoclinic oxides HfO{sub 2} and ZrO{sub 2} exhibit quasi-2D polaron localization and conductivity, which results from a small difference in the coordination of two oxygen sublattices in these materials. The transition between a 2D large polaron into a zero-dimensional small polaron state requires overcoming a small energetic barrier. These results demonstrate how a small asymmetry in the lattice structure can determine the qualitative character of polaron localization and significantly broaden the realm of quasi-2D polaron systems.

McKenna, K. P.; Wolf, M. J.; Shluger, A. L.; Lany, S.; Zunger, A.

2012-03-16T23:59:59.000Z

271

Photochemistry in Terrestrial Exoplanet Atmospheres III: Photochemistry and Thermochemistry in Thick Atmospheres on Super Earths and Mini Neptunes  

E-Print Network (OSTI)

Some super Earths and mini Neptunes will likely have thick atmospheres that are not H2-dominated. We have developed a photochemistry-thermochemistry kinetic-transport model for exploring the compositions of thick atmospheres on super Earths and mini Neptunes, applicable for both H2-dominated atmospheres and non-H2-dominated atmospheres. Using this model to study thick atmospheres for wide ranges of temperatures and elemental abundances, we classify them into hydrogen-rich atmospheres, water-rich atmospheres, oxygen-rich atmospheres, and hydrocarbon-rich atmospheres. We find that carbon has to be in the form of CO2 rather than CH4 or CO in a H2-depleted water-dominated thick atmosphere, and that the preferred loss of light elements from an oxygen-poor carbon-rich atmosphere leads to formation of unsaturated hydrocarbons (C2H2 and C2H4). We apply our self-consistent atmosphere models to compute spectra and diagnostic features for known transiting low-mass exoplanets GJ 1214 b, HD 97658 b, and 55 Cnc e. For GJ 1...

Hu, Renyu

2014-01-01T23:59:59.000Z

272

Plants making oxygen  

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

Plants making oxygen Plants making oxygen Name: Doug Status: N/A Age: N/A Location: N/A Country: N/A Date: Around 1993 Question: How many plants are needed to make enough oxygen for one person for one hour? We are experimenting with Anacharis plants. Replies: The problem can be solved when broken down into smaller questions: 1. How much oxygen does a person need in an hour? 2. How much oxygen does a plant produce in an hour? 3. Based on the above, how many plants will provide the oxygen needs of the person for the hour? Here is the solution to the first question: A resting, healthy adult on an average, cool day breathes in about 53 liters of oxygen per hour. An average, resting, health adult breathes in about 500 mL of air per breath. This is called the normal tidal volume. Now, 150 mL of this air will go to non- functioning areas of the lung, called the "dead space." The average breath rate for this average person is 12 breaths per minute. So, the amount of air breathed in by the person which is available for use is 12 x (500 mL -150 mL) = 4,200 mL/minute. Multiply by 60 to get 252,000 mL/hour. That is, every hour, the person will breathe in 252 L of air. Now, on an average, cool, clear day, only 21% of that air is oxygen. So, 21% of 252 L is 53 L. So, in an hour, the person breathes in about 53 L of oxygen.

273

Polarized neutron reflectometry from the interface of the heterostructures SiO2(Co)/Si and SiO2(Co)/GaAs  

Science Journals Connector (OSTI)

Polarized neutron reflectometry is used to investigate SiO2(Co) granular films (70at% of Co nanoparticles in SiO2 matrix) deposited on Si and GaAs substrates. The aim of the study is to compare magnetization depth profiles in two systems: in SiO2(Co)/GaAs heterostructure which shows at room temperature giant injection magnetoresistance (IMR) with the system SiO2(Co)/Si which reveals almost no IMR effect. We found that at room temperature and at the same value of external magnetic field mean magnetization in the SiO2(Co)/GaAs sample is much higher than in the case of SiO2(Co)/Si. We also demonstrate that magnetic scattering length density, and hence, magnetization profile strongly depends on the substrate. We show that SiO2(Co)/Si heterostructure is ferromagnetically ordered within the temperature range between 120 and 460K what could explain a weak IMR.

Ekaterina A. Dyadkina; Natalia A. Grigoryeva; Alexey A. Vorobiev; Sergey V. Grigoriev; Leonid V. Lutsev; Kirill Zhernenkov; Maximilian Wolff; Dieter Lott; Alexander I. Stognij; Nicolay N. Novitskii; Boris P. Toperverg

2009-01-01T23:59:59.000Z

274

Ultraviolet and Visible Photochemistry of Methanol at 3D Mesoporous Networks: TiO2 and AuTiO2  

Science Journals Connector (OSTI)

A higher excited-state electron density arises for UV-irradiated TiO2 aerogel relative to commercial nanoparticulate TiO2, indicating that 3D networked TiO2 more efficiently separates electronhole pairs. ... For both UV and visible irradiation, the same light source was employed: a high-pressure 350-W mercury arc lamp (Oriel Corp.) equipped with a water filter to remove IR radiation. ... For visible irradiation, three bandpass filters (70 nm full-width at half-maximum transmission profile) were used with peak transmissions centered at 400, 500, or 550 nm. ...

Dimitar A. Panayotov; Paul A. DeSario; Jeremy J. Pietron; Todd H. Brintlinger; Lindsey C. Szymczak; Debra R. Rolison; John R. Morris

2013-05-23T23:59:59.000Z

275

Journal of Chromatography A, 1161 (2007) 113120 Quantifying sesquiterpene and oxygenated terpene emissions from live  

E-Print Network (OSTI)

. This technique can be applied for quantification of biogenic oxygenated terpene and sesquiterpene emissions from@nature.berkeley.edu (N.C. Bouvier-Brown). 1 Present address: Institute for Marine and Atmospheric Research, Utrecht

Cohen, Ronald C.

276

Interfacial Layer Growth Condition Dependent Carrier Transport Mechanisms in HfO2/SiO2 Gate Stacks  

SciTech Connect

The temperature and field dependent leakage current in HfO{sub 2}/SiO{sub 2} gate stack for in situ steam grown and chemical interfacial layers (ILs) are studied in the temperature range of 20 C to 105 C. Poole-Frenkel mechanism in high field whereas Ohmic conduction in low field region are dominant for both devices. Leakage current decreases whereas both trap energy level ({phi}{sub t}) and activation energy (E{sub a}) increase for chemically grown IL devices. The trap level energy, ({phi}{sub t}) -0.2 eV, indicates that doubly charged oxygen vacancies (V{sup 2-}) are the active electron traps which contribute to the leakage current in these gate stacks.

Sahoo, S. K.; Misra, D.

2012-06-04T23:59:59.000Z

277

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect

In the present quarter, oxygen transport perovskite ceramic membranes are evaluated for strength and fracture in oxygen gradient conditions. Oxygen gradients are created in tubular membranes by insulating the inner surface from the reducing environment by platinum foils. Fracture in these test conditions is observed to have a gradient in trans and inter-granular fracture as opposed to pure trans-granular fracture observed in homogeneous conditions. Fracture gradients are reasoned to be due to oxygen gradient set up in the membrane, variation in stoichiometry across the thickness and due to varying decomposition of the parent perovskite. The studies are useful in predicting fracture criterion in actual reactor conditions and in understanding the initial evolution of fracture processes.

Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

2002-07-01T23:59:59.000Z

278

The Birth and Life of Our Atmosphere  

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

Birth and Life of Our Atmosphere Birth and Life of Our Atmosphere Nature Bulletin No. 554-A February 15, 1975 Forest Preserve District of Cook County George W. Dunne, President Roland F. Eisenbeis, Supt. of Conservation THE BIRTH AND LIFE OF OUR ATMOSPHERE In Bulletin No. 542-A we described the atmosphere that surrounds the earth, held there by the pull of gravity, including the canopy of air immediately above us. That canopy is responsible for our weather and climates, shields us from the killing rays of the sun, and furnishes substances necessary for all life: oxygen, nitrogen, carbon dioxide, and water vapor. Astronomers believe that none of the other planets -- excepting Mars, perhaps -- has an atmosphere anything like ours. The principal elements, free nitrogen (78 percent) and free oxygen (21 percent), apparently are rare in the universe. On the other hand, the earth's atmosphere contains only traces of free hydrogen and helium -- the two lightest gases -- whereas they are by far the most common elements elsewhere in the universe.

279

Magnetism of solid oxygen  

Science Journals Connector (OSTI)

Magnetic susceptibilities of single-crystal ?-O2 and preferentially oriented polycrystalline samples of ?-O2 and ?-O2 have been measured, employing a mutual-inductance bridge method. The susceptibility of paramagnetic ?-O2 is isotropic and exhibits a temperature dependence which is not strictly Curie-Weiss, due to short-range correlations and partially hindered rotation. The susceptibility of ?-O2 exhibits very little anisotropy, but has an unusual temperature dependence which is probably due to the novel behavior of the lattice constants, modulation of inplane and out-of-plane exchange interactions, and short-range order. The susceptibility of anti-ferromagnetic ?-O2 is anisotropic, and data from five differently oriented samples have been analyzed in terms of principal antiferromagnetic susceptibilities. The data are consistent with the assumption that the easy axis is the twofold axis, b??, though the direction a?? cannot be excluded. A comprehensive analysis of the present susceptibility results and other magnetic, spectroscopic, and thermal measurements is made, with special reference to ?-O2. The perpendicular susceptibility implies an unreasonably large Nel temperature, 211 K, and a correspondingly large intersublattice exchange interaction, |J2|k=19.8 K. The effects of anisotropy and zeropoint spin deviations do not reduce this estimate by more than 15%. The temperature dependence of the parallel susceptibility suggests a much smaller value for the effective exchange interaction, |J|k=5.3 K, and appears to be well accounted for assuming a single spin-wave excitation. Antiferromagnetic resonance frequencies are analyzed and shown to yield, on assuming a dominant anisotropy equal to that of the free molecule, |J2|k=4.3 K. An approximate separation of lattice and magnetic heat capacities is effected, and a value |J|k=3.0 K deduced. The data appear to require the assumption of two spin-wave modes. Except for the perpendicular susceptibility, experimental results suggest a Nel temperature between 30 and 40 K. Meanfield and other theories lead to similar estimates, assuming that |J|k is between 3 and 4 K. The effect of the anisotropy on TN is minor, and no significant spin-shortening effect is predicted. Other experimental results are considered, and a disparate set of estimates for the exchange interaction and zone-boundary spin-wave energies is discussed. Including the effects of intrasublattice exchange interactions within the context of a two-sublattice model does not seem sufficient to remove the various discrepancies. An approximate calculation of relative overlap integrals and exchange interactions between different pairs of molecules in ?-O2 is made. It is suggested that a multisublattice model for the magnetic structure, and possibly one involving noncollinear sublattices, may provide an eventual resolution of the various difficulties. A "quasi-two-dimensional" description of ?-O2 is also considered, but appears not to offer a satisfactory explanation of the unusual and imperfectly correlated properties of this phase.

Gary C. DeFotis

1981-05-01T23:59:59.000Z

280

Unusual Physical and Chemical Properties of Cu in Ce1-xCuxO2 Oxides  

SciTech Connect

The structural and electronic properties of Ce{sub 1-x}Cu{sub x}O{sub 2} nano systems prepared by a reverse microemulsion method were characterized with synchrotron-based X-ray diffraction, X-ray absorption spectroscopy, Raman spectroscopy, and density functional calculations. The Cu atoms embedded in ceria had an oxidation state higher than those of the cations in Cu{sub 2}O or CuO. The lattice of the Ce{sub 1-x}Cu{sub x}O{sub 2} systems still adopted a fluorite-type structure, but it was highly distorted with multiple cation-oxygen distances with respect to the single cation-oxygen bond distance seen in pure ceria. The doping of CeO{sub 2} with copper introduced a large strain into the oxide lattice and favored the formation of O vacancies, leading to a Ce{sub 1-x}Cu{sub x}O{sub 2-y} stoichiometry for our materials. Cu approached the planar geometry characteristic of Cu(II) oxides, but with a strongly perturbed local order. The chemical activities of the Ce{sub 1-x}Cu{sub x}O{sub 2} nanoparticles were tested using the reactions with H2 and O2 as probes. During the reduction in hydrogen, an induction time was observed and became shorter after raising the reaction temperature. The fraction of copper that could be reduced in the Ce{sub 1-x}Cu{sub x}O{sub 2} oxides also depended strongly on the reaction temperature. A comparison with data for the reduction of pure copper oxides indicated that the copper embedded in ceria was much more difficult to reduce. The reduction of the Ce{sub 1-x}Cu{sub x}O{sub 2} nanoparticles was rather reversible, without the generation of a significant amount of CuO or Cu{sub 2}O phases during reoxidation. This reversible process demonstrates the unusual structural and chemical properties of the Cu-doped ceria materials.

Wang,X.; Rodriguez, J.; Hanson, J.; Gamarra, D.; Martinez-Arias, A.; Fernandez-Garcia, M.

2005-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "atmospheric oxygen o2" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
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to obtain the most current and comprehensive results.


281

Appendix B: CArBon dioxide CApture teChnology SheetS Oxygen PrOductiOn  

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Oxygen PrOductiOn Oxygen PrOductiOn B-500 Oxygen PrOductiOn u.S. dePartment Of energy advanced carbOn diOxide caPture r&d PrOgram: technOlOgy uPdate, may 2013 itm Oxygen technOlOgy fOr integratiOn in igcc and Other advanced POwer generatiOn SyStemS primary project goals Air Products and Chemicals set out to design and develop an ion transport membrane (ITM) based on ceramics that selectively transport oxygen (O 2 ) ions when operated at high temperature. This high-temperature process may be integrated with advanced power genera- tion processes that require O 2 as a feedstock, such as integrated gasification combined cycle (IGCC) and other clean energy and industrial applications. technical goals * Design, construct, and operate a 0.1-ton/day (TPD) technology development unit

282

Raman spectroscopic study of the pressure-induced coordination change in GeO2 glass  

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Raman spectra of GeO2 glass are recorded in situ as a function of pressure to 56 GPa at room temperature. Under initial compression to 6 GPa the main 419-cm-1 Raman band shifts to higher frequency and broadens with a gradual loss of intensity. These spectral changes are consistent with an increase in distortion of GeO4 tetrahedra and a decrease in the intertetrahedral bond angle with pressure. Between 6 and 13 GPa (the pressure range of the reported fourfold- to sixfold-coordination change of Ge in germania glass) the main Raman band broadens, and the scattering intensity is dramatically reduced with little shift in peak frequency. This pressure interval is also marked with the appearance and growth of a broad low-frequency band near 240 cm-1. The inferred pressure-induced coordination change occurs without the formation of nonbridging oxygens. Above 13 GPa no further major structural changes are indicated by the Raman data taken with pressures up to 56 GPa. On decompression the back transformation of octahedral Ge to tetrahedral coordination is complete but exhibits a large hysteresis. The Raman data indicate that the high-coordinate germanium species are retained down to pressures of at least 2.3 GPa. In samples decompressed from high pressures, the intensity of the 520-cm-1 defect band is considerably enhanced relative to that in normal germania glass, consistent with an increase in three-membered-ring population. It is proposed that a large component of this increase in three-membered rings is a result of the reversion of OIII species to tetrahedra-bridging OII species under decompression.

Dan J. Durben and George H. Wolf

1991-01-15T23:59:59.000Z

283

IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 35, NO. 3, JUNE 2007 693 Atmospheric Plasma Actuators for  

E-Print Network (OSTI)

IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 35, NO. 3, JUNE 2007 693 Atmospheric Plasma Actuators- charges, flow control. I. INTRODUCTION PLASMA, operating in atmospheric pressure air conditions, holds atmospheric plasma that mainly consists of nitrogen/oxygen plasma components, which are coupled to an electric

Huang, Xun

284

Pulse of atmospheric oxygen during the late Cambrian  

Science Journals Connector (OSTI)

...relative to the prasinophyte green algae (which were members of the green plastid group, and likely the dominant...approximately 6N HCl to remove carbonate minerals. Insoluble...rhythmically bedded argillaceous lime- stones and calcareous shales...

Matthew R. Saltzman; Seth A. Young; Lee R. Kump; Benjamin C. Gill; Timothy W. Lyons; Bruce Runnegar

2011-01-01T23:59:59.000Z

285

Anaerobic methanotrophy and the rise of atmospheric oxygen  

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...around 29mM of sulphate, which is often well mixed by fauna into a bioturbation zone...hydrothermal (F V) plus metamorphism/geothermal reductants (F M), following an argument...oil and gas seeps in deepwater Gulf of Mexico. Geochim. Cosmochim. Acta. 64, 233-246...

2007-01-01T23:59:59.000Z

286

Photocatalytic effects of wool fibers modified with solely TiO2 nanoparticles and N-doped TiO2 nanoparticles by using hydrothermal method  

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Abstract The surfaces of wool fibers are modified with N-doped TiO2 nanoparticles by treating the fibers with tetrabutyl titanate and ammonium chloride under low temperature hydrothermal conditions to obtain wool fibers with photocatalytic functions in the visible light spectrum. The effects of nitrogen and sulfur in amino acids in keratin on the photocatalytic activity of TiO2 particle coated wool fibers are investigated. Changes of various fiber properties such as tensile strength, photocatalytic activity, and self-cleaning performance of untreated, TiO2 coated and N-doped TiO2 coated wool fibers are studied. It is found that N-doped anatase TiO2 nanoparticles with an average grain size of 11.2nm are synthesized and simultaneously grafted onto the wool fibers. After treatments, the crystallization index of the wool fibers is slightly reduced. The capability to protect against ultraviolet radiation is much enhanced. The performances of photocatalytic degradation of methylene blue dye and self-cleaning of red wine under both UV and visible light irradiation are endowed. It is also found that wool fibers coated with TiO2 particles without being doped by nitrogen still have apparent photocatalytic reactions and self-cleaning effects under visible light irradiation due to the formation of C-Ti3+, O-Ti3+, and N-Ti3+ bonds between TiO2 and wool keratin on the wool fiber surfaces. Thus wool fabrics might not need to be coated with N-doped TiO2 nanoparticles to realize its self-cleaning effect under visible light. Such important conclusions would provide wool materials with wide applications in clothing and technical products such as wastewater treatment.

Hui Zhang; Zhenwei Yang; Xingtao Zhang; Ningtao Mao

2014-01-01T23:59:59.000Z

287

RESPONSE TO OXYGEN DEFICIENCY SENSING EQUIPMENT IN LABORATORIES  

E-Print Network (OSTI)

/or lights to warn both the room occupants and those outside the room of the hazard within. 2. Equipment: Vacuum flask that holds liquid air or helium for scientific experiments. Hazardous Atmosphere. Type and location of oxygen deficiency monitoring equipment. When New York Fire Department (FDNY

Jia, Songtao

288

High-pressure structure of half-metallic CrO2 B. R. Maddox  

E-Print Network (OSTI)

transition from rutile -CrO2 phase I P42/mnm to orthorhombic -CrO2 phase II CaCl2-like, Pnnm is presented. The transition to the CaCl2 structure, which appears to be second order, occurs at 12±3 GPa without any typically transforms to another sixfold-coordinated structure, CaCl2, or the -PbO2 structure found in shock

Pickett, Warren

289

HCl Oxidation on IrO2-Based Catalysts: From Fundamentals to Scale-Up  

Science Journals Connector (OSTI)

HCl Oxidation on IrO2-Based Catalysts: From Fundamentals to Scale-Up ... (ii) Geometric and electronic effects of TiO2-rutile are predicted not to lead to improved HCl oxidation activity for 1 and 2 epilayers of IrO2 over the carrier. ... From a fundamental viewpoint, it would be interesting to assess whether rutile-type oxides exhibit similar Deacon chemistry. ...

Maximilian Moser; Cecilia Mondelli; Amol P. Amrute; Atsushi Tazawa; Detre Teschner; Manfred E. Schuster; Achim Klein-Hoffman; Nria Lpez; Timm Schmidt; Javier Prez-Ramrez

2013-10-17T23:59:59.000Z

290

X-ray absorption study of the O 2p hole concentration dependence on O stoichiometry in YBa/sub 2/Cu/sub 3/O/sub x/  

SciTech Connect

A detailed x-ray absorption study of the oxygen K edge of YBa/sub 2/Cu/sub 3/O/sub x/ is presented. A preedge peak is observed for all samples with xgreater than or equal to6.4 which we argue to be due to holes in the O 2p band. By comparison to Li/sub x/Ni/sub (1-//sub x//sub )/O the x dependence of the number of O 2p holes in YBa/sub 2/Cu/sub 3/O/sub x/ is determined.

Kuiper, P.; Kruizinga, G.; Ghijsen, J.; Grioni, M.; Weijs, P.J.W.; de Groot, F.M.F.; Sawatzky, G.A.; Verweij, H.; Feiner, L.F.; Petersen, H.; and others

1988-10-01T23:59:59.000Z

291

Oxygen Transport Ceramic Membranes  

SciTech Connect

The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and studies on newer composition of Ti doped LSF. In this report, in situ neutron diffraction was used to characterize the chemical and structural properties of La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} (here after as L2SF55T) specimen, which was subject to measurements of neutron diffraction from room temperature to 900 C in N{sub 2}. Space group of R3c was found to result in a better refinement and is used in this study. The difference for crystal structure, lattice parameters and local crystal chemistry for LSFT nearly unchanged when gas environment switched from air to N{sub 2}. Stable crack growth studies on Dense OTM bars provided by Praxair were done at room temperature in air. A bridge-compression fixture was fabricated to achieve stable pre-cracks from Vickers indents. Post fracture evaluation indicated stable crack growth from the indent and a regime of fast fracture. Post-fracture X-ray data of the OTM fractured at 1000 C in environment were refined by FullProf code and results indicate a distortion of the parent cubic perovskite to orthorhombic structure with reduced symmetry. TGA-DTA studies on the post-fracture samples also indicated residual effect arising from the thermal and stress history of the samples. The thermal and chemical expansion of La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} were studied at 800 {le} T {le} 1000 C and at {approx} 1 x 10{sup -15} {le} pO{sub 2} {le} 0.21 atm. The thermal expansion coefficient of the sample was calculated from the dilatometric analysis in the temperature range between room temperature and 1200 C in air. A series of isotope transients under air separation mode (small gradient) were completed on the membrane of LSCrF-2828 at 900 C. Low pO{sub 2} atmospheres based on with CO-CO{sub 2} mixtures have also been admitted to the delivery side of the LSCrF-2828 membrane to produce the gradients which exist under syngas generation conditions. The CO-CO{sub 2} mixtures have normal isotopic {sup 18}O abundances. The evolution of {sup 18}O on the delivery side in these experiments after an {sup 18}O pulse on the air side reveals a wealth of information about the oxygen transport processes.

S. Bandopadhyay; N. Nagabhushana; X.-D Zhou; Q. Cai; J. Yang; W.B. Yelon; W.J. James; H.U. Anderson; Alan Jacobson; C.A. Mims

2004-05-01T23:59:59.000Z

292

Novel Spillover Interrelating Reversible Electrocatalysts for Oxygen and Hydrogen Electrode Reactions  

Science Journals Connector (OSTI)

New striking prospects both in low and medium temperature polymer electrolyte membrane fuel cell (PEMFC) and in water electrolysis (WE) have been opened by the interactive supported individual (Pt) or prevailing hyper-d-electronic nanostructured metal clusters (WPt3, NbPt3, HfPd3, ZrNi3), grafted upon and within high altervalent capacity hypo-d-oxides (WO3, NbO2, TaO2, TiO2) and their proper mixed valence compounds, to create a novel type of alternating polarity (alterpolar) interchangeable composite electrocatalysts for hydrogen and oxygen electrode reactions. ... In such a constellation of longer stepwise development, the present study emphasizes the need for a thorough review and combination of the main older sequential data and prehistory, to get the final version of a specific electrocatalytic theory and discuss it in the light of new insights. ... Nanostructured reversibly interchangeable (Pt/H0.35WO3 ? Pt/W(OH)6) alterpolar bronze type, and its TiO2 modified (Pt/Nb2O5,TiO2/C, Pt/WO3,TiO2/C) electrocatalyst issues for hydrogen and primarily oxygen electrode reactions (HER, HOR, ORR, OER), have for the first time been developed and produced by a proper sol?gel synthetic method. ...

Jelena M. Jaksic; Diamantoula Labou; Georgos D. Papakonstantinou; Angeliki Siokou; Milan M. Jaksic

2010-10-08T23:59:59.000Z

293

Crystal phase transition of HfO2 films evaporated by plasma-ion-assisted deposition  

Science Journals Connector (OSTI)

HfO2 is a well-known high-refractive-index material for optical interference coatings from the infrared down to the ultraviolet

Wang, Jue; Maier, Robert L; Schreiber, Horst

2008-01-01T23:59:59.000Z

294

Crystal Phase Transition of HfO2 Films Evaporated by Plasma Ion-Assisted Deposition  

Science Journals Connector (OSTI)

HfO2 films were evaluated by spectroscopic ellipsometry, indicating crystal phase transition due to plasma ion momentum transfer during deposition. The film inhomogeneity,...

Wang, Jue; Maier, Robert L; Schreiber, Horst

295

Photoelectrochemical Water Splitting of Nitrogen and Hydrogen Treated P25 TiO2 Films  

E-Print Network (OSTI)

CdS and CdSe have been successfully employed in the sensitization of TiO 2 . Although sensitization and doping

Zavodivker, Liat Shari

2014-01-01T23:59:59.000Z

296

Mechanism of Methane Chemical Looping Combustion with Hematite Promoted with CeO2  

Science Journals Connector (OSTI)

Mechanism of Methane Chemical Looping Combustion with Hematite Promoted with CeO2 ... Industrial & Engineering Chemistry Research2014 53 (42), 16341-16348 ...

Duane D. Miller; Ranjani Siriwardane

2013-02-28T23:59:59.000Z

297

Microbial oxygen uptake in sludge as influenced by compost physical parameters1 Ardavan Mohajer1  

E-Print Network (OSTI)

1 Microbial oxygen uptake in sludge as influenced by compost physical parameters1 Ardavan Mohajer1 uptake rate (OUR) in 16 sludge waste recipes, offering a4 range of moisture content (MC), waste to 14 days to20 evaluate the overall O2 consumption or biodegradability of a sludge mixture.21 Keywords

Paris-Sud XI, Université de

298

Palaeoproterozoic ice houses and the evolution of oxygen-mediating enzymes: the case for a late  

E-Print Network (OSTI)

Palaeoproterozoic ice houses and the evolution of oxygen-mediating enzymes: the case for a late evolved. One solution to the first problem is the accumulation of photochemically produced H2O2 at the surface of the glaciers and its subsequent incorporation into ice. Melting at the glacier base would

299

Effect of Microstructure of Nitrogen-Doped Graphene on Oxygen Reduction Activity in Fuel Cells  

Science Journals Connector (OSTI)

Effect of Microstructure of Nitrogen-Doped Graphene on Oxygen Reduction Activity in Fuel Cells ... The optimized structures for OOH, OOH+ or O2 adsorption (ads) to graphene were obtained through structural optimization calculations. ... Thus, to optimize the catalytic performance, materials structures should be controlled to have small N doping clusters in combination with material defects. ...

Lipeng Zhang; Jianbing Niu; Liming Dai; Zhenhai Xia

2012-04-10T23:59:59.000Z

300

1 - Solubility of Atmospheric Gases in Freshwater  

Science Journals Connector (OSTI)

This chapter presents tabular information on the standard air saturation concentration (moist air at 1atm) for oxygen, nitrogen, argon, and carbon dioxide gas in terms of ?mol/kg, mg/L, and mL/L; and in terms of Bunsen coefficients L real gas/(Latm); mg real gas/(LmmHg); and mg real gas/(LkPa) for 040C and freshwater conditions. Because the mole fraction of carbon dioxide in the atmosphere is changing, solubility information is provided for 2010 (390?atm) and for 2030 (440?atm) based on projected atmospheric values. Tabular information is also provided to allow computation of standard air saturation concentrations of carbon dioxide gas directly as a function of atmospheric mole fraction. Conversion factors are presented to convert these concentrations to other commonly used units. Equations and tabular information are provided to compute air saturation concentration for moist air at local barometric pressure for the four atmospheric gases. Because of the importance of dissolved oxygen in biological processes, the air solubility concentration is also presented as a function of elevation for both metric and English elevations. Equations and tabular information are provided to allow conversion of concentrations in mg/L to partial pressures in mmHg. Sample problems are included for representative examples. Keywords gas solubility, freshwater, oxygen, nitrogen, argon, carbon dioxide, standard air solubility, air solubility, Bunsen coefficients, partial pressures

John Colt

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "atmospheric oxygen o2" 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

Interfacial Layer Growth Condition Dependent Electrical Conduction in HfO2/SiO2 Heterostructured Thin Films  

SciTech Connect

The electrical conduction mechanism contributing to the leakage current at different field regions has been studied in this work. The current-voltage (I-V) measurement of TiN/HfO{sub 2}/SiO{sub 2}/P-Si nMOS capacitor has been taken for two different interfacial layer (SiO{sub 2}) growth conditions such as in situ steam grown (ISSG) and chemical processes. It is observed that Poole-Frenkel mechanism is the dominant conduction mechanism in high field region whereas Ohmic conduction is dominant in the low field region. Also it is seen that the gate leakage current is reduced for the devices having chemically grown interfacial layer compared to that of ISSG devices. Both trap energy level ({phi}{sub t}) and activation energy (E{sub a}) increase in the chemically grown interfacial layer devices for the Poole-Frenkel and Ohmic conduction mechanisms respectively in comparison to ISSG devices. Trap energy level ({phi}{sub t}) of {approx} 0.2 eV, obtained from Poole-Frenkel mechanism indicates that the doubly ionized oxygen vacancies (V{sup 2-}) are the active defects and are contributing to the leakage current in these devices.

Sahoo, S. K.; Misra, D.

2012-01-01T23:59:59.000Z

302

Adsorption of water on O(2x2)/Ru(0001): thermal stability and inhibition of dissociation by H2O-O bonding  

SciTech Connect

The effect of preadsorbed oxygen on the subsequent adsorption and reactions of water on Ru(0001) has been studied using low temperature scanning tunneling microscopy and DFT calculations. Experiments were carried out for O coverages close to 0.25 ML. It was found that no dissociation of water takes place up to the desorption temperature of {approx}180-230 K. DFT calculations show that intact water on O(2x2)/Ru(0001) is {approx} 0.49 eV more stable than the dissociation products, H and OH, at their preferred fcc and top adsorption sites.

Mugarza, Aitor; Shimizu, Tomoko; Cabrera-Sanfelix, Pepa; Sanchez-Portal, Daniel; Arnau, Andres; Salmeron, Miquel

2008-08-01T23:59:59.000Z

303

In Situ Ambient Pressure X-ray Photoelectron Spectroscopy Studies of Lithium-Oxygen Redox Reactions  

SciTech Connect

The lack of fundamental understanding of the oxygen reduction and oxygen evolution in nonaqueous electrolytes significantly hinders the development of rechargeable lithium-air batteries. Here we employ a solid-state Li4+xTi5O12/LiPON/LixV2O5 cell and examine in situ the chemistry of Li-O2 reaction products on LixV2O5 as a function of applied voltage under ultra high vacuum (UHV) and near ambient-pressure of oxygen using X-ray photoelectron spectroscopy (APXPS). Oxygen reduction and evolution reactions take place on the surface of the mixed electronic and Li+ ionic conductor, LixV2O5, which eliminate parasitic reactions between oxygen reduction/evolution reaction intermediates and aprotic electrolytes used in Li-O2 batteries reported to date. Under UHV, reversible lithium intercalation and de-intercalation from LixV2O5 was noted, where the changes in the vanadium valence state revealed from XPS in this study were comparable to that reported previously from Li/LixV2O5 thin film batteries. In presence of oxygen near ambient pressure, the LixV2O5 surface was covered gradually by the reaction product of oxygen reduction, namely lithium peroxide (Li2O2) (approximately 1-2 unit cells) upon discharge. Interestingly, the LixV2O5 surface became re-exposed upon charging, and the oxidation of Li2O2 began at much lower overpotentials (~240 mV) than the charge overpotentials of Li-O2 cells (~1000 mV) with aprotic electrolytes, which can be attributed to subnanometer-thick Li2O2 with surfaces free of contaminants such as carbonate species. Our study provides first evidence of reversible lithium peroxide formation and decomposition in situ on an oxide surface using a solid-state cell, and new insights into the reaction mechanism of Li-O2 chemistry.

Lu, Yi-chun [Massachusetts Institute of Technology (MIT); Crumlin, Ethan [Massachusetts Institute of Technology (MIT); Veith, Gabriel M [ORNL; Harding, Jonathon [Massachusetts Institute of Technology (MIT); Dudney, Nancy J [ORNL; Liu, Zhi [Lawrence Berkeley National Laboratory (LBNL); Shao-Horn, Yang [Massachusetts Institute of Technology (MIT)

2012-01-01T23:59:59.000Z

304

Solar energy: Hydrogen and oxygen  

Science Journals Connector (OSTI)

Solar energy: Hydrogen and oxygen ... Demonstrating the electrolysis of water with solar energy. ...

John J. Farrell

1982-01-01T23:59:59.000Z

305

Optical oxygen concentration monitor  

DOE Patents (OSTI)

A system for measuring and monitoring the concentration of oxygen uses as a light source an argon discharge lamp, which inherently emits light with a spectral line that is close to one of oxygen`s A-band absorption lines. In a preferred embodiment, the argon line is split into sets of components of shorter and longer wavelengths by a magnetic field of approximately 2,000 Gauss that is parallel to the light propagation from the lamp. The longer wavelength components are centered on an absorption line of oxygen and thus readily absorbed, and the shorter wavelength components are moved away from that line and minimally absorbed. A polarization modulator alternately selects the set of the longer wavelength, or upshifted, components or the set of the shorter wavelength, or downshifted, components and passes the selected set to an environment of interest. After transmission over a path through that environment, the transmitted optical flux of the argon line varies as a result of the differential absorption. The system then determines the concentration of oxygen in the environment based on the changes in the transmitted optical flux between the two sets of components. In alternative embodiments modulation is achieved by selectively reversing the polarity of the magnetic field or by selectively supplying the magnetic field to either the emitting plasma of the lamp or the environment of interest. 4 figs.

Kebabian, P.

1997-07-22T23:59:59.000Z

306

Non-conductive TiO2 as the anode catalyst support for PEM water electrolysis  

Science Journals Connector (OSTI)

The applicability of a non-conductive TiO2 as the support of the anodic catalyst for PEM water electrolysis was tested. Three TiO2 samples with different specific surface areas were modified by IrO2 using a modified version of the Adams fusion method. A constant weight ratio of IrO2/TiO2 of 0.6 was maintained in all cases. The size, specific surface area and morphology of IrO2 electrocatalyst crystallites were investigated by X-ray diffraction, nitrogen adsorption (BET) and scanning electron microscopy, respectively. The electron conductivity of compressed catalyst powders was evaluated. Their electrochemical properties were studied on a rotating disk electrode (RDE) and finally in a laboratory electrolyser. Utilization of the TiO2 support resulted in a reduction in the size of the IrO2 crystallites. It was found that the lower the specific surface area of the supports, the higher was the electrochemical activity of the catalyst. This is most likely due to the formation of a conductive IrO2 film on the surface of non-conductive supports. For the supports with a higher surface area, the amount of IrO2 used was not sufficient to form an adequately compact film. This resulted in high electron resistance of such a catalyst. The RDE results were confirmed by a laboratory electrolysis test. Taken together with the excellent stability of TiO2 in an anodic environment, these results suggest that these materials are promising supports if the appropriate amount of iridium is deposited.

Petr Mazr; Jakub Polonsk; Martin Paidar; Karel Bouzek

2012-01-01T23:59:59.000Z

307

Rate Analysis of Chemical-Looping with Oxygen Uncoupling (CLOU) for Solid Fuels  

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The present study is concerned with the rate analysis from reported batch fluidized bed CLOU experimental data of Mexican petcoke particles by a CuO/ZrO2 oxygen carrier. ... Analysis of the CLOU Experiments for Combustion of Mexican Petcoke(4, 5) ... A 4560 fold increase in reaction rate has been reported of the carbon residue in petcoke when reacted with a CuO based oxygen carrier in CLOU experiments, compared to the CLC process with an iron based oxygen carrier in the temperature range 950985 C. ...

Asad H. Sahir; Hong Yong Sohn; Henrik Leion; JoAnn S. Lighty

2012-05-24T23:59:59.000Z

308

Key role of organic carbon in the sunlight-enhanced atmospheric aging of soot by O2  

Science Journals Connector (OSTI)

...polar compounds originating from the oxidation and combustion processes were not probed by GC-MS analysis. This may...aromatic carbonyls, which are generated directly by combustion processes and upon PAHs oxidation, are well-known photosensitizers...

Chong Han; Yongchun Liu; Jinzhu Ma; Hong He

2012-01-01T23:59:59.000Z

309

Oxygen in Underwater Cave  

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

Oxygen in Underwater Cave Oxygen in Underwater Cave Name: Natalie Status: student Grade: 9-12 Location: HI Country: USA Date: Spring 2011 Question: Is it possible for there to be free oxygen in an underwater cave? If it is, then how does it work? Replies: Yes it is possible as I have personally experienced. If the cave roof rises to a level above the water, air dissolved in the water will slowly out gas until the water is at the same level at all places. A pocket of breathable air will form. In many caves the roof dips below water level in one place but it above it on both sides. Think of a U shaped tube where the bottom of the U is blocked by water. This is called a siphon and I have passed through many of these to find breathable air on the other side. R. W. "Bob" Avakian Oklahoma State Univ. Inst. of Technology

310

Holographically Defined TiO2 Electrodes for Dye-Sensitized Solar Cells  

Science Journals Connector (OSTI)

Holographically Defined TiO2 Electrodes for Dye-Sensitized Solar Cells ... We analyze the morphological features of the h-TiO2 electrodes and consider their applicability to dye-sensitized solar cells (DSSCs). ... holographic lithography; solar cells ...

Woo-Min Jin; Ju-Hwan Shin; Chang-Yeol Cho; Ji-Hwan Kang; Jong Hyeok Park; Jun Hyuk Moon

2010-10-27T23:59:59.000Z

311

Flexible Free-Standing Graphene/SnO2 Nanocomposites Paper for Li-Ion Battery  

Science Journals Connector (OSTI)

A flexible free-standing graphene/SnO2 nanocomposites paper (GSP) was prepared by coupling a simple filtration method and a thermal reduction together for the first time. Compared with the pure SnO2 nanoparticles, the GSP exhibited a better cycling ...

Junfei Liang; Yue Zhao; Lin Guo; Lidong Li

2012-10-22T23:59:59.000Z

312

Carbon monoxide annealed TiO2 nanotube array electrodes for efficient biosensor applications  

E-Print Network (OSTI)

Carbon monoxide annealed TiO2 nanotube array electrodes for efficient biosensor applications by anodic oxidation of titanium foil followed with O2 and CO annealing were employed as matrices consisted of Ti3+ defects with carbon-doping and exhibited well defined quasi-reversible cyclic voltammetric

Cao, Guozhong

313

Highly ordered TiO2 macropore arrays as transparent photocatalysts  

Science Journals Connector (OSTI)

Highly ordered transparent TiO2 macropore arrays were synthesized via a simple glass-clamping method at room temperature. The as-synthesized TiO2 macropore arrays show high transmittance in the visible light region and can be used ...

Yuan Dong; Junfeng Chao; Zhong Xie; Xin Xu; Zhuoran Wang; Di Chen

2012-01-01T23:59:59.000Z

314

Surface studies of nitrogen implanted TiO2 Matthias Batzill a,*, Erie H. Morales b  

E-Print Network (OSTI)

.V. All rights reserved. Keywords: Titanium dioxide; Doping; Nitrogen; Surface science 1. IntroductionSurface studies of nitrogen implanted TiO2 Matthias Batzill a,*, Erie H. Morales b , Ulrike Diebold Available online 3 August 2007 Abstract Rutile TiO2(110) single crystals have been doped by nitrogen

Diebold, Ulrike

315

Synthesis, characterization and performance of vanadium hexacyanoferrate as electrocatalyst of H2O2  

E-Print Network (OSTI)

in environmental, food, and industrial analysis; it is used to pollution control, to bleach textiles and paper.01­3.0 mM H2O2 was constructed. Limit of detection (S/N = 3) of 4 lM H2O2 was calculated. The proposed

Trikalitis, Pantelis N.

316

Effect of Al addition on the microstructure and electronic structure of HfO2 film  

E-Print Network (OSTI)

Effect of Al addition on the microstructure and electronic structure of HfO2 film X. F. Wang investigated the microstructures and electronic structures of a series of hafnium aluminate HfAlO films with Al concentration ranging from 0% to 100%. When the films evolve from pure HfO2 to pure Al2O3 by increasing

Gong, Xingao

317

The Ternary System CaO-MgO-SiO2  

Science Journals Connector (OSTI)

...2SiO2 have not been previously noted. This latter compound has practically identical optical properties with the mineral akermanite for which the formula 8CaO.4MgO.9SiO2 has been proposed, by Schaller. The summarized temperature and concentration relations...

J. B. Ferguson; H. E. Merwin

1919-01-01T23:59:59.000Z

318

Transformation plasticity and thermoelastic behavior in ZrO2-containing ceramics  

E-Print Network (OSTI)

565 Transformation plasticity and thermoelastic behavior in ZrO2-containing ceramics A. H. Heuer plasticité de transformation dans ZrO2, qui est responsable de la ré- sistance mécanique et de la grande profit. Dans certaines conditions, cette transformation est réversible, autocatalytique et

Paris-Sud XI, Université de

319

Photosynthesis Respiration CH2O + O2 CO2 + H2O  

E-Print Network (OSTI)

Energy and life Photosynthesis Respiration CH2O + O2 CO2 + H2O hv Biomass CO2 + H2O CH2O + O2 ASSOCIATED WITH PHOTOSYNTHESIS) #12;ATP*: the "energy currency" of the cell *Adenosine triphospahte) PHOTOSYNTHESIS Light provides the energy for high energy electrons. The source of electrons is water OXIDATIVE

320

Structure and transformation of the metastable boron- and oxygen-related defect center in crystalline silicon  

Science Journals Connector (OSTI)

We analyze the core structure of the carrier-lifetime-reducing boron- and oxygen-related metastable defect center in crystalline silicon by measuring the correlation of the defect concentration with the boron and the oxygen contents on a large number of different silicon materials. The experimental results indicate that the defect is composed of one substitutional boron and two interstitial oxygen atoms. Formation and annihilation of the metastable boron-oxygen complex are found to be thermally activated processes, characterized by two strongly differing activation energies. Measurements of the defect generation rate as a function of light intensity show that the defect generation rate increases proportionally with light intensity below 1 mW/cm2 and saturates at higher intensities. All experimental results can be consistently explained using a defect reaction model based on fast-diffusing oxygen dimers (O2i), which are captured by substitutional boron (Bs) to form a metastable Bs-O2i complex. Based on this model, new strategies for an effective reduction of the light degradation of solar cells made on oxygen-rich silicon materials are derived. The model also explains why no lifetime degradation is observed in aluminum-, gallium-, and indium-doped oxygen-rich silicon.

Jan Schmidt and Karsten Bothe

2004-01-22T23:59:59.000Z

Note: This page contains sample records for the topic "atmospheric oxygen o2" 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

Dimerization Induced Deprotonation of Water on RuO2(110)  

SciTech Connect

RuO2 has proven to be indispensable as a co-catalyst in numerous systems designed for photocatalytic water splitting. In this study we have carried out a detailed mechanistic study of water behavior on the most stable RuO2 face, RuO2(110), by employing variable temperature scanning tunneling microscopy and density functional theory calculations. We show that water monomers adsorb molecularly on Ru sites, become mobile above 238 K, diffuse along the Ru rows and form water dimers. The onset for dimer diffusion is observed at ~277 K indicating significantly higher diffusion barrier than that for monomers. More importantly, we find that water dimers deprotonate readily to form Ru-bound H3O2 and bridging OH species. The observed behavior is compared and contrasted with that observed for water on isostructural rutile TiO2(110).

Mu, Rentao; Cantu Cantu, David; Lin, Xiao; Glezakou, Vassiliki Alexandra; Wang, Zhitao; Lyubinetsky, Igor; Rousseau, Roger J.; Dohnalek, Zdenek

2014-10-02T23:59:59.000Z

322

Controlled atmosphere for fabrication of cermet electrodes  

DOE Patents (OSTI)

A process for making an inert electrode composite wherein a metal oxide and a metal are reacted in a gaseous atmosphere at an elevated temperature of at least about 750.degree. C. The metal oxide is at least one of the nickel, iron, tin, zinc and zirconium oxides and the metal is copper, silver, a mixture of copper and silver or a copper-silver alloy. The gaseous atmosphere has an oxygen content that is controlled at about 5-3000 ppm in order to obtain a desired composition in the resulting composite.

Ray, Siba P. (Murrysville, PA); Woods, Robert W. (New Kensington, PA)

1998-01-01T23:59:59.000Z

323

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect

In the present quarter, the possibility of using a more complex interfacial engineering approach to the development of reliable and stable oxygen transport perovskite ceramic membranes/metal seals is discussed. Experiments are presented and ceramic/metal interactions are characterized. Crack growth and fracture toughness of the membrane in the reducing conditions are also discussed. Future work regarding this approach is proposed are evaluated for strength and fracture in oxygen gradient conditions. Oxygen gradients are created in tubular membranes by insulating the inner surface from the reducing environment by platinum foils. Fracture in these test conditions is observed to have a gradient in trans and inter-granular fracture as opposed to pure trans-granular fracture observed in homogeneous conditions. Fracture gradients are reasoned to be due to oxygen gradient set up in the membrane, variation in stoichiometry across the thickness and due to varying decomposition of the parent perovskite. The studies are useful in predicting fracture criterion in actual reactor conditions and in understanding the initial evolution of fracture processes.

Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

2003-01-01T23:59:59.000Z

324

Optical oxygen concentration monitor  

DOE Patents (OSTI)

A system for measuring and monitoring the concentration of oxygen uses as a light source an argon discharge lamp, which inherently emits light with a spectral line that is close to one of oxygen's A-band absorption lines. In a preferred embodiment, the argon line is split into sets of components of shorter and longer wavelengths by a magnetic field of approximately 2000 Gauss that is parallel to the light propagation from the lamp. The longer wavelength components are centered on an absorption line of oxygen and thus readily absorbed, and the shorter wavelength components are moved away from that line and minimally absorbed. A polarization modulator alternately selects the set of the longer wavelength, or upshifted, components or the set of the shorter wavelength, or downshifted, components and passes the selected set to an environment of interest. After transmission over a path through that environment, the transmitted optical flux of the argon line varies as a result of the differential absorption. The system then determines the concentration of oxygen in the environment based on the changes in the transmitted optical flux between the two sets of components. In alternative embodiments modulation is achieved by selectively reversing the polarity of the magnetic field or by selectively supplying the magnetic field to either the emitting plasma of the lamp or the environment of interest.

Kebabian, Paul (Acton, MA)

1997-01-01T23:59:59.000Z

325

Spectroscopic study of the ? phase of solid oxygen  

Science Journals Connector (OSTI)

The infrared spectrum of the ? phase of solid oxygen has been studied between room temperature and 20 K as a function of pressure up to 63 GPa. Besides the strong absorption in the fundamental O2 vibron mode and the broad doublet in the overtone region, another peak is detected in the far infrared region. The analysis of the overtone bands allows the determination of the density of states of the O2 vibron region which consists of two separated energy regions, including one the infrared and the other the Raman bands observed in the 15001650?cm-1 range. This result, consistent with the analysis of the other Raman and infrared bands at lower frequency, is interpreted on the basis of a crystal composed by a molecular unit formed by four oxygen atoms. This hypothesis explains the strong infrared absorption which is in contrast with the model of a crystal composed by diatomic oxygen molecules. Very thin crystalline slabs (measure the intensity of the strong infrared absorption at 15001550?cm-1. The measurement of the Raman spectrum as a function of the incident power and of the laser excitation frequency shows how the intensity and the frequency of the Raman lines are affected by the experimental conditions. Finally, a simple chain model provides indirect proof of our assignment of the low-frequency infrared mode and allows to rule out an association in polymeric units formed by more than four atoms even at pressures close to the insulator-metal transition.

Federico A. Gorelli; Lorenzo Ulivi; Mario Santoro; Roberto Bini

2001-02-20T23:59:59.000Z

326

Au/PO43-/TiO2 and PO43-/Au/TiO2 catalysts for CO oxidation: effect of synthesis details on catalytic performance  

SciTech Connect

Supported gold catalysts are active for CO oxidation, but the high-temperature deactivation is a shortcoming that may constrain their applications. Herein, we attempted to address this problem by using phosphate-doped Au/TiO{sub 2} synthesized via two routes. In route I, Au/PO{sub 4}{sup 3-}/TiO{sub 2} catalysts were prepared by treating TiO{sub 2} (Degussa P25) with diluted H{sub 3}PO{sub 4}, followed by loading gold via deposition-precipitation. In route II, PO{sub 4}{sup 3-}/Au/TiO{sub 2} catalysts were prepared by treating H{sub 2}-reduced Au/TiO{sub 2} with diluted H{sub 3}PO{sub 4}. These catalysts were systematically pretreated at 200 or 500 C before reaction testing. The overall CO conversion on 200 C-pretreated Au/PO43-/TiO2 or PO43-/Au/TiO2 was always lower than that on 200 C-pretreated Au/TiO2. However, the advantage of the phosphate addition became apparent after thermal treatment at a higher temperature. Both Au/PO43-/TiO2 and PO43-/Au/TiO2 pretreated at 500 C retained significant activities at room temperature, whereas 500 C-pretreated Au/TiO2 lost its activity. Control experiments and catalyst characterization were performed to investigate the impact of synthesis details on catalytic performance.

Ma, Zhen [ORNL; Overbury, Steven {Steve} H [ORNL; Dai, Sheng [ORNL

2007-01-01T23:59:59.000Z

327

Interaction of mineral matter of coal with oxygen carriers in chemical-looping combustion (CLC)  

Science Journals Connector (OSTI)

Abstract The chemical-looping combustion (CLC) and chemical-looping with oxygen uncoupling (CLOU) processes are novel solutions for efficient combustion with direct separation of carbon dioxide. These processes use a metal oxide as an oxygen carrier to transfer oxygen from an air to a fuel reactor, where the fuel reacts with the solid oxygen carrier. When utilizing coal in CLC, the oxygen carrier particles could be affected through interaction with the ash-forming mineral matter found in coal, causing deactivation and/or agglomeration. In this work, possible interactions between minerals commonly encountered in coal and several promising oxygen carriers that are currently under investigation for their use in CLC are studied by both experiment and thermodynamic equilibrium calculations. Possible interaction was studied for both highly reducing and oxidizing conditions at 900C. Under highly reducing conditions pyrite was found to have by far the most deteriorating effect on the oxygen carrier particles, as the sulfur in the pyrite reacted with the oxygen carrier to form sulfides. Quartz and clay minerals were found to have a rather low influence on the oxygen carriers. Out of the oxygen carriers investigated, CuO/MgAl2O4 and the Mn3O4/ZrO2 oxygen carriers tended to be quite reactive towards mineral matter whereas ilmenite has been shown to be the most robust oxygen carrier. Although sulfur can clearly deactivate Ni, Cu and Mn based oxygen carriers under sub-stoichiometric conditions, when the fuel is converted fully to CO2 and H2O, sulfides are only expected for Ni-based oxygen carriers.

Martin Keller; Mehdi Arjmand; Henrik Leion; Tobias Mattisson

2014-01-01T23:59:59.000Z

328

Electrical transport and structural study of CuCr1?xMgxO2 delafossite thin films grown by pulsed laser deposition  

Science Journals Connector (OSTI)

The growth and properties of delafossites CuCr1?xMgxO2 thin films are examined. These films are grown by pulsed laser deposition. As a class of materials delafossites have received recent interest since some members show p-type behavior. While not considered true wide-bandgap materials due to a narrow indirect bandgap that fails to adsorb light due to a forbidden same parity transition, optical transparencies greater than 40% in the visible can be observed. In order to be useful for transparent device applications, CuCr1?xMgxO2 films are needed with low resistivity and high optical transparency. Epitaxial films of CuCr1?xMgxO2 were grown on c-sapphire, examining the effects of oxygen pressure and growth temperature on film properties. Films were realized with resistivity of ~0.02?-cm and optical transparency of 40% in the visible. The formation of a problematic secondary minority spinel phase of (Cu,Mg)Cr2O4 is discussed. While conductivity increases substantially with Mg doping, the incidence of the spinel phase increases as well.

P.W. Sadik; M. Ivill; V. Craciun; D.P. Norton

2009-01-01T23:59:59.000Z

329

Increased intrapulmonary retention of radiolabeled neutrophils in early oxygen toxicity  

SciTech Connect

Sequential lung injuries, such as oxygen toxicity followed by septicemia, are common during the adult respiratory distress syndrome (ARDS). As these forms of vascular injury may be mediated in part by polymorphonuclear leukocytes (PMN), aberrant interactions between PMN and previously injured pulmonary endothelium are of both theoretical interest and clinical importance. The present study was undertaken to test the hypothesis that early oxygen toxicity at a dose that injuries pulmonary endothelium relatively selectively alters intrapulmonary neutrophil kinetics. Unanesthetized rats breathing 1.0 atmospheres oxygen for 36 h showed ultrastructural endothelial damage but no edema, injury, or neutrophilic inflammation by histologic criteria. However, in these oxygen-toxic animals, whereas initial accumulation of radiolabeled PMN in lungs was normal, washout of PMN was abnormal at 120 min after infusion, at which point the pulmonary retention of radiolabeled PMN in the lungs of oxygen-treated animals was significantly higher than in control animals (139% of control, p less than 0.0096). Features of our methodology, including avoidance of osmotic stress and use of paired control animals, appear to have greatly enhanced the sensitivity of radiolabeled neutrophils for detecting a subtle abnormality of neutrophil-endothelial interactions. Our studies in the oxygen toxicity model provide the first demonstration in vivo of abnormal intrapulmonary neutrophil kinetics in early oxygen toxicity prior to the onset of histologic evidence of lung injury or inflammation.

Rinaldo, J.E.; English, D.; Levine, J.; Stiller, R.; Henson, J.

1988-02-01T23:59:59.000Z

330

Using ethanol for preparation of nanosized TiO2 by gaseous detonation  

Science Journals Connector (OSTI)

A method of preparing nanosized titanium dioxide by gaseous detonation by using ethanol, hydrogen, and oxygen as an explosion...

H. H. Yan; X. C. Huang; S. X. Xi

2014-03-01T23:59:59.000Z

331

Highly efficient oxidation of silicon at low temperatures using atmospheric pressure plasma  

Science Journals Connector (OSTI)

Silicon oxide ( Si O 2 ) layers were formed with initial oxidation rates in the range of 6.2 14.1 nm ? min in the temperature range of 150 400 C by oxidizing Si(001) wafers. Such a high-rate and low-temperature oxidation was realized by using a stable glow He ? O 2 plasma excited at atmospheric pressure by a 150 MHz very high-frequency power. Increasing the temperature led to both the higher oxidation rate and the better quality of Si O 2 and Si O 2 ? Si interface. The oxidation at 400 C showed an interface trap density of 6.2 10 10 eV ? 1 cm ? 2 which is considerably lower than that in a radical oxidation process using low-pressure He ? O 2 plasma at the same temperature.

Hiroaki Kakiuchi; Hiromasa Ohmi; Makoto Harada; Heiji Watanabe; Kiyoshi Yasutake

2007-01-01T23:59:59.000Z

332

High-pressure phases in SnO2 to 117 GPa Sean R. Shieh*  

E-Print Network (OSTI)

for SnO2 is rutile-type P42/mnm CaCl2-type Pnnm pyrite-type Pa3¯ ZrO2 orthorhombic phase I Pbca cotunnite of phase transitions from rutile P42/mnm to CaCl2-type Pnnm to -PbO2-type Pbcn to pyrite-type Pa3¯ have the rutile to CaCl2-type transforma- tion near 12 GPa. They also reported that the cubic phase was actually

Duffy, Thomas S.

333

Optical Absorption, Stability and Structure of NpO2+ Complexeswith Dicarboxylic Acids  

SciTech Connect

Complexation of NpO2+ with oxalic acid (OX),2,2'-oxydiacetic acid (ODA), 2,2'-iminodiacetic acid (IDA) and 2,2'-thiodiacetic acid (TDA), has been studied using spectrophotometry in1 M NaClO4. Both the position and the intensity of the absorption band of NpO2+ at 980 nm are affected by the formation of NpO2+/dicarboxylate complexes, providing useful information on the complexation strength, the coordination mode and the structure of the complexes.

Guoxin Tian; Linfeng Rao

2006-01-04T23:59:59.000Z

334

E? Centers in Amorphous SiO2 Revisited: A New Look at an Old Problem  

Science Journals Connector (OSTI)

We present theoretical evidence that the paramagnetic E? defect centers in amorphous silicon dioxide ( a-SiO2) do not have the same microscopic structures as those well-defined in the corresponding crystalline counterparts such as ?-quartz. We then present alternative models of some paramagnetic defects that account for the underlying experimental features of the E?-center variants in a-SiO2. We suggest that our new model should take the place of the conventional defect model of a-SiO2.

T. Uchino; M. Takahashi; T. Yoko

2001-06-11T23:59:59.000Z

335

Electron Source in Photoinduced Hydrogen Production on Pt-supported TiO2 Particles  

Science Journals Connector (OSTI)

Electron Source in Photoinduced Hydrogen Production on Pt-supported TiO2 Particles ... After recovering the TiO2/Pt particles used in the long-term reaction, they were reused in a photocatalytic H+ reduction by adding methanol as an electron donor, but no H2 production was observed showing that the TiO2/Pt particles have lost their photocatalytic activity after the long-term reaction. ... A 100 W high-pressure Hg lamp was used as a light source. ...

Toshiyuki Abe; Eiji Suzuki; Kentaro Nagoshi; Kohichi Miyashita; Masao Kaneko

1999-02-04T23:59:59.000Z

336

Preparation of Highly Transparent TiO2-based Thin Film Photocatalysts by an Ion Engineering Method: Ionized Cluster Beam Deposition  

Science Journals Connector (OSTI)

Highly transparent TiO2 and TiO2-based binary oxide (TiO2/SiO2 and TiO2/B2O3) thin films of different TiO2 contents were successfully prepared by using an ion engineering technique as a dry process. These transpa...

Masato Takeuchi; Masakazu Anpo

2010-01-01T23:59:59.000Z

337

High pressure oxygen furnace  

DOE Patents (OSTI)

A high temperature high pressure oxygen furnace having a hybrid partially externally heated construction is disclosed. A metallic bar fabricated from an alloy having a composition of at least 45% nickel, 15% chrome, and 10% tungsten is utilized, the preferred alloy including 55% nickel, 22% chrome, 14% tungsten, 2% molybdenum, 3% iron (maximum) and 5% cobalt (maximum). The disclosed alloy is fabricated into 11/4 inch bar stock and has a length of about 17 inches. This bar stock is gun drilled for over 16 inches of its length with 0.400 inch aperture to define a closed high temperature, high pressure oxygen chamber. The opposite and closed end of the bar is provided with a small support aperture into which both a support and a thermocouple can be inserted. The closed end of the gun drilled bar is inserted into an oven, preferably heated by standard nickel chrome electrical elements and having a heavily insulated exterior. 5 figs.

Morris, D.E.

1992-07-14T23:59:59.000Z

338

High pressure oxygen furnace  

DOE Patents (OSTI)

A high temperature high pressure oxygen furnace having a hybrid partially externally heated construction is disclosed. A metallic bar fabricated from an alloy having a composition of at least 45% nickel, 15% chrome, and 10% tungsten is utilized (the preferred alloy including 55% nickel, 22% chrome, 14% tungsten, 2% molybdenum, 3% iron (maximum) and 5% cobalt (maximum). The disclosed alloy is fabricated into 11/4 inch bar stock and has a length of about 17 inches. This bar stock is gun drilled for over 16 inches of its length with 0.400 inch aperture to define a closed high temperature, high pressure oxygen chamber. The opposite and closed end of the bar is provided with a small support aperture into which both a support and a thermocouple can be inserted. The closed end of the gun drilled bar is inserted into an oven, preferably heated by standard nickel chrome electrical elements and having a heavily insulated exterior.

Morris, Donald E. (Kensington, CA)

1992-01-01T23:59:59.000Z

339

Microelectronically fabricated LiCoO2/SiO2/polycrystalline-silicon power cells planarized by chemical mechanical polishing  

E-Print Network (OSTI)

. Integrating a power unit onto a silicon chip requires the implementation of a thin-film solid-state battery as a solid-state electrolyte in our integrated thin-film battery. This SiO2 electrolyte layer is thermally in the fabrication of the integrated solid-state thin-film lithium-ion battery. Polishing the polysilicon layer

340

Comparison of the neutron, Raman, and infrared vibrational spectra of vitreous SiO2, GeO2, and BeF2  

Science Journals Connector (OSTI)

The inelastic neutron, Raman, and infrared vibrational spectra of vitreous SiO2, GeO2, and BeF2 are reported in detail and compared with one another. The neutron spectrum is shown to be a good measure of the vibrational density of states for glassy SiO2 and GeO2, but a poorer measure for BeF2. The density of states is shown to be split into transverse-opticallongitudinal-optical bands whose nature is revealed in the infrared and Raman spectra. Empirical selection rules are noted, including the observation that the HV Raman spectrum "mimics" the density of states, while the HH spectrum is dominated by matrix-element effects. The spectra are discussed in terms of an augmented central-force model which allows prediction of selection rules and relative densities of states. The latter allows an empirical estimate of the frequency dependence of the neutron scattering coupling coefficients, showing relatively weak scattering by acoustic modes, especially in the case of BeF2 glass.

F. L. Galeener; A. J. Leadbetter; M. W. Stringfellow

1983-01-15T23:59:59.000Z

Note: This page contains sample records for the topic "atmospheric oxygen o2" 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

EFFECT OF SiO2 TICKNESSES IN THERMAL-SiO2/PECVD-SiN STACKS ON SURFACE PASSIVATION OF n-TYPE Cz SILICON SUBSTRATES  

E-Print Network (OSTI)

. A prominent example of SiO2 surface passivation is given by the world-record solar cell efficiency of the passivated-emitter and rear locally- diffused (PERL) c-Si solar cell [1]. The surface passivation of the as the standard RCA procedure prior to oxidation in a cleaned quartz furnace tube at high temperat

342

Oxygen Transport Ceramic Membranes  

SciTech Connect

The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and studies on newer composition of Ti doped LSF. In the previous research, the reference point of oxygen occupancy was determined and verified. In the current research, the oxygen occupancy was investigated at 1200 C as a function of oxygen activity and compared with that at 1000 C. The cause of bumps at about 200 C was also investigated by using different heating and cooling rates during TGA. The fracture toughness of LSFT and dual phase membranes at room temperature is an important mechanical property. Vicker's indentation method was used to evaluate this toughness. Through this technique, a K{sub Ic} (Mode-I Fracture Toughness) value is attained by means of semi-empirical correlations between the indentation load and the length of the cracks emanating from the corresponding Vickers indentation impression. In the present investigation, crack propagation behavior was extensively analyzed in order to understand the strengthening mechanisms involved in the non-transforming La based ceramic composites. Cracks were generated using Vicker's indenter and used to identify and evaluate the toughening mechanisms involved. Preliminary results of an electron microscopy study of the origin of the slow kinetics on reduction of ferrites have been obtained. The slow kinetics appear to be related to a non-equilibrium reduction pathway that initially results in the formation of iron particles. At long times, equilibrium can be reestablished with recovery of the perovskite phase. Modeling of the isotopic transients on operating membranes (LSCrF-2828 at 900 C) and a ''frozen'' isotope profile have been analyzed in conjunction with a 1-D model to reveal the gradient in oxygen diffusivity through the membrane under conditions of high chemical gradients.

S. Bandopadhyay; T. Nithyanantham; X.-D Zhou; Y-W. Sin; H.U. Anderson; Alan Jacobson; C.A. Mims

2005-08-01T23:59:59.000Z

343

Oxygen abundances in the most oxygen-rich spiral galaxies  

E-Print Network (OSTI)

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

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

2006-01-06T23:59:59.000Z

344

Oxygen Concentration Microgradients for Cell Culture  

E-Print Network (OSTI)

The Chemotactic Effect of Oxygen on Bacteria, J. Pathol.Measurement and Control of Oxygen Levels in MicrofluidicA Microfabricated Electrochemical Oxygen Generator for High-

Park, Jaehyun

2010-01-01T23:59:59.000Z

345

Oxygen Release and Oxidation Rates of MgAl2O4-Supported CuO Oxygen Carrier for Chemical-Looping Combustion with Oxygen Uncoupling (CLOU)  

Science Journals Connector (OSTI)

The choice of wood char was made after comparing the oxygen concentration in the reactors exit stream, using different solid fuels and taking advantage of the high reactivity of the wood char, compared to other available fuels (e.g., coal or petcoke). ... The required solids inventory in the fuel reactor obtained here is lower than a previously reported investigation for a 40 wt?% CuO on ZrO2 support using petcoke as fuel (120200 kg MWth1)(34) and a recent study of continuous operation using a spray-dried 60 wt?% CuO on MgAl2O4 support (235 kg MWth1 at 960 C),(22) but is in close agreement with the values obtained by Adnez-Rubio et al.(48) for the spray-dried 60 wt?% CuO on MgAl2O4 support (39 kg MWth1 at 930 C). ... data of Mexican petcoke particles by a CuO/ZrO2 oxygen carrier. ...

Mehdi Arjmand; Martin Keller; Henrik Leion; Tobias Mattisson; Anders Lyngfelt

2012-10-03T23:59:59.000Z

346

Surface modification and aging effect of polysulfonamide yarns treated by atmospheric pressure plasma  

Science Journals Connector (OSTI)

The effect of atmospheric pressure plasma treatment on wettability and dyeability of polysulfonamide ... were investigated. The helium and helium/oxygen plasma-treated PSA yarns were stored for different...K/S......

C. X. Wang; J. C. Lv; D. W. Gao; G. L. Liu; L. M. Jin; J. H. Liu

2013-09-01T23:59:59.000Z

347

Dust in brown dwarfs and extra-solar planets IV. Assessing TiO2 and SiO nucleation for cloud formation modeling  

E-Print Network (OSTI)

Clouds form in atmospheres of brown dwarfs and planets. The cloud particle formation processes are similar to the dust formation process studied in circumstellar shells of AGB stars and in Supernovae. Cloud formation modelling in substellar objects requires gravitational settling and element replenishment in addition to element depletion. All processes depend on the local conditions, and a simultaneous treatment is required. We apply new material data in order to assess our cloud formation model results regarding the treatment of the formation of condensation seeds. We re-address the question of the primary nucleation species in view of new (TiO2)_N-cluster data and new SiO vapour pressure data. We apply the density functional theory using the computational chemistry package Gaussian 09 to derive updated thermodynamical data for (TiO2)_N-clusters as input for our TiO2 seed formation model. We test different nucleation treatments and their effect on the overall cloud structure by solving a system of dust momen...

Lee, G; Giles, H; Bromley, S T

2014-01-01T23:59:59.000Z

348

Syngas production by CO2 reforming of coke oven gas over Ni/La2O3ZrO2 catalysts  

Science Journals Connector (OSTI)

Abstract Syngas production by CO2 reforming of coke oven gas (COG) was studied in a fixed-bed reactor over Ni/La2O3ZrO2 catalysts. The catalysts were prepared by solgel technique and tested by XRF, BET, XRD, H2-TPR, TEM and TGDSC. The influence of nickel loadings and calcination temperature of the catalysts on reforming reaction was measured. The characterization results revealed that all of the catalysts present excellent resistance to coking. The catalyst with appropriate nickel content and calcination temperature has better dispersion of active metal and higher conversion. It is found that the Ni/La2O3ZrO2 catalyst with 10wt% nickel loading provides the best catalytic activity with the conversions of CH4 and CO2 both more than 95% at 800C under the atmospheric pressure. The Ni/La2O3ZrO2 catalysts show excellent catalytic performance and anti-carbon property, which will be of great prospects for catalytic CO2 reforming of COG in the future.

Wei Tao; Hongwei Cheng; Weilin Yao; Xionggang Lu; Qiuhua Zhu; Guangshi Li; Zhongfu Zhou

2014-01-01T23:59:59.000Z

349

Synthesis and Analysis of TiO2-Oligonucleotide Hybrid Nanoparticles  

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

Synthesis and Analysis of TiO2-Oligonucleotide Hybrid Nanoparticles Synthesis and Analysis of TiO2-Oligonucleotide Hybrid Nanoparticles New developments in nanotechnology offer the creation of chemical-biological hybrid nanocomposites, which can be introduced into cells to initiate intracellular processes or biochemical reactions. Researchers from Northwestern University Medical Center (Chicago, IL) and Argonne National Laboratory synthesized TiO2-oligonucleotide nanocomposites made of DNA oligonucleotides attached to 45-Å TiO2 nanoparticles and tested them by using the 2-ID-E x-ray beamline at the X-ray Operations and Research sector 2 of the APS. A key benefit of nanocomposites is that they could advance medical biotechnology and open new doors in chemistry and materials sciences. Scan of a 21 x 21-m area with a single nucleus containing 3.6 x 106 nanoparticles.

350

Benefits and technological challenges in the implementation of TiO2-based  

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

Benefits and technological challenges in the implementation of TiO2-based Benefits and technological challenges in the implementation of TiO2-based ultraviolet photocatalytic oxidation (UVPCO) air cleaners Title Benefits and technological challenges in the implementation of TiO2-based ultraviolet photocatalytic oxidation (UVPCO) air cleaners Publication Type Conference Proceedings Year of Publication 2008 Authors Hodgson, Alfred T., Hugo Destaillats, Toshifumi Hotchi, and William J. Fisk Conference Name Indoor Air 2008 Pagination 17-22 Date Published August 2008 Publisher Indoor Air, Paper ID: 297 Conference Location Copenhagen, Denmark Abstract Indoor air cleaners based on TiO2 photocatalytic oxidation of organic pollutants are a promising technology to improve or maintain indoor air quality while reducing ventilation energy costs. We evaluated the performance of a pilot scale UVPCO air cleaner under realistic conditions in single pass and recirculation modes

351

Photoluminescence of SnO2 nanoparticles embedded in Al2O3. |...  

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

in Al2O3 substrate fabricated by ion implantation. Citation: Xiang X, XT Zu, S Zhu, LM Wang, V Shutthanandan, P Nachimuthu, and Y Zhang.2008."Photoluminescence of SnO2...

352

Ordered mesoporous carbon/SnO2 composites as the electrode material for supercapacitors  

Science Journals Connector (OSTI)

A series of composites as electrode materials for supercapacitors were prepared via incipient wetness impregnation method utilizing ordered mesoporous carbon (OMC) and tin (IV) oxide (SnO2) with different ratio. ...

Ping Liu ??; Bohejin Tang; Jiachang Zhao

2011-06-01T23:59:59.000Z

353

MnO2-Based Electrochemical Supercapacitors on Flexible Carbon Substrates  

Science Journals Connector (OSTI)

Manganese dioxide films were grown on large area flexible carbon aerogel substrates. Characterization by x-ray diffraction confirmed ?-MnO2 growth. Three types of films were compared as a function of hexamethylen...

Marko J. Tadjer; Michael A. Mastro; Jos M. Rojo

2014-04-01T23:59:59.000Z

354

Electrode Characteristics of Individual, MnO2 Coated Carbon Nanotubes  

E-Print Network (OSTI)

MnO2 Coated Carbon Nanotubes Brad L. Corso, Israel Perez,single- walled carbon nanotubes. Li ion cyclic voltammetrysingle-walled carbon nanotubes (SWNTs) that are grown in

Collins, Philip G

2011-01-01T23:59:59.000Z

355

TiO2 Nanoparticles as a Soft X-ray Molecular Probe  

SciTech Connect

With the emergence of soft x-ray techniques for imaging cells, there is a pressing need to develop protein localization probes that can be unambiguously identified within the region of x-ray spectrum used for imaging. TiO2 nanocrystal colloids, which have a strong absorption cross-section within the "water-window" region of x-rays, areideally suited as soft x-ray microscopy probes. To demonstrate their efficacy, TiO2-streptavidin nanoconjugates were prepared and subsequently labeled microtubules polymerized from biotinylated tubulin. The microtubules were imaged using scanning transmission x-ray microscopy (STXM), and the TiO2 nanoparticle tags were specifically identified using x-ray absorption near edge spectroscopy (XANES). These experiments demonstrate that TiO2 nanoparticles are potential probes for protein localization analyses using soft x-ray microscopy.

Larabell, Carolyn; Ashcroft, Jared M.; Gu, Weiwei; Zhang, Tierui; Hughes, Steven M.; Hartman, Keith B.; Hofmann, Cristina; Kanaras, Antonios G.; Kilcoyne, David A.; Le Gros, Mark; Yin, Yadong; Alivisatos, A. Paul; Larabell, Carolyn A.

2007-06-30T23:59:59.000Z

356

Molecular Hydrogen Formation from Proximal Glycol Pairs on TiO2(110)  

SciTech Connect

Understanding hydrogen formation on TiO2 surfaces is of great importance as it could provide fundamental insight into water splitting for hydrogen production using solar energy. In this work, hydrogen formation from glycols having different numbers of methyl end-groups have been studied using temperature pro-grammed desorption on reduced, hydroxylated, and oxidized TiO2(110) surfaces. The results from OD-labeled glycols demon-strate that gas-phase molecular hydrogen originates exclusively from glycol hydroxyl groups. The yield is controlled by a combi-nation of glycol coverage, steric hindrance, TiO2(110) order and the amount of subsurface charge. Combined, these results show that proximal pairs of hydroxyl aligned glycol molecules and subsurface charge are required to maximize the yield of this redox reaction. These findings highlight the importance of geometric and electronic effects in hydrogen formation from adsorbates on TiO2(110).

Chen, Long; Li, Zhenjun; Smith, R. Scott; Kay, Bruce D.; Dohnalek, Zdenek

2014-04-16T23:59:59.000Z

357

Anodic CaO-TiO2 nanotubes composite film for low temperature CO2 adsorption  

Science Journals Connector (OSTI)

A novel one-dimensional anodic CaO-TiO2 nanotubes composite film was prepared using a rapid-anodic oxidation electrochemical anodization technique for low temperature CO2 absorption application. This study aims to determine the ...

Chin Wei Lai

2014-01-01T23:59:59.000Z

358

Selectivity Changes During Organic Photooxidation on TiO2: Role...  

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

but the t-butyl radical has several options for thermal chemistry. In ultrahigh vacuum (UHV), where the O2 partial pressure is <1x10-10 torr, the TMA photodecomposition results...

359

Atomic Structure of the Anatase TiO2(001) Surface. | EMSL  

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

deciphering site-specific thermal and photo- reaction mechanisms on anatase TiO2. Using UHV scanning tunneling microscopy (STM), we have studied the atomic structure of anatase...

360

LiCoO2-and LiMn2O4-based composite cathode materials  

Science Journals Connector (OSTI)

We have prepared composite cathode materials based on two electrochemically active compounds, LiCoO2 and LiMn2O4..., and investigated their properties. The results indicate that the discharge capacities of all th...

Ya. V. Shatilo; E. V. Makhonina; V. S. Pervov; V. S. Dubasova

2006-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "atmospheric oxygen o2" 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

Increment of specific heat capacity of solar salt with SiO2 nanoparticles  

Science Journals Connector (OSTI)

In this work, salt-based nanofluid based on solar salt and SiO2...nanoparticles prepared by the Shin and Banerjee method was investigated. The optimal nanoparticle concentration was found and the stability of the...

Patricia Andreu-Cabedo; Rosa Mondragon; Leonor Hernandez

2014-10-01T23:59:59.000Z

362

SnO2/graphene composite with high lithium storage capability for lithium rechargeable batteries  

Science Journals Connector (OSTI)

SnO2/graphene nanocomposites have been fabricated by a simple...2...nanoparticles to be formed and uniformly decorated on the graphene. The electrostatic attraction between a graphene nanosheet (GNS) and the echi...

Haegyeom Kim; Sung-Wook Kim; Young-Uk Park; Hyeokjo Gwon; Dong-Hwa Seo

2010-11-01T23:59:59.000Z

363

TiO2/graphene nanocomposites as anode materials for high rate lithium-ion batteries  

Science Journals Connector (OSTI)

A simple strategy to prepare a hybrid of nanocomposites of anatase TiO2/graphene nanosheets (GNS) as anode materials for lithium-ion batteries was reported. The morphology and crystal structure...2/GNS electrode ...

Yi-ping Tang ???; Shi-ming Wang ???; Xiao-xu Tan ???

2014-05-01T23:59:59.000Z

364

FinalTechnicalReport_15U5O2I-11_RPSEA.docx  

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

Technical Report RPSEA - Research Partnership to Secure Energy for America Report No.: 15U502I-11, Rev. 2 Document No.: 15U5O2I-11 Date: 2014-12-30 DNV GL - Report No....

365

TiO2-based photocatalytic process for purification of polluted water: bridging fundamentals to applications  

Science Journals Connector (OSTI)

Recent years have witnessed a rapid accumulation of investigations on TiO2-based photocatalysis, which poses as a greatly promising advanced oxidation technology for water purification. As the ability of this advanced oxidation process is ...

Chuan Wang; Hong Liu; Yanzhen Qu

2013-01-01T23:59:59.000Z

366

The progress of TiO2 nanocrystals doped with rare earth ions  

Science Journals Connector (OSTI)

In the past decades, TiO2 nanocrystals (NCs) have been widely studied in the fields of photoelectric devices, optical communication, and environment for their stability in aqueous solution, being nontoxic, cheapness, and so on. Among the three ...

Hai Liu; Lixin Yu; Weifan Chen; Yingyi Li

2012-01-01T23:59:59.000Z

367

Thermal analyses of LiCoO2 lithium-ion battery during oven tests  

Science Journals Connector (OSTI)

A three dimensional thermal abuse model for graphite/LiPF6/LiCoO2 batteries is established particularly for oven tests. To ... of heat release condition and oven temperature on battery thermal behaviors, we perfo...

Peng Peng; Yiqiong Sun; Fangming Jiang

2014-10-01T23:59:59.000Z

368

Synthesis and photocatalytic activity of ZnO/TiO2 nanoparticle  

Science Journals Connector (OSTI)

ZnO/TiO2 photocatalysts were synthesised via wet-chemical techniques. These can subsequently be used as efficient photocatalysts which can effectively degrade organic contaminants. Photocatalysts prepared with these techniques were characterised with X-ray diffraction (XRD), infrared (FTIR) spectrophotometer, UV-visible spectroscopy and photo luminescence. XRD confirmed the formation of ZnO/TiO2 nanoparticle. UV-visible spectroscopy showed significant difference in the optical absorption. Enhancement in optical absorption of ZnO/TiO2 indicated that it can be used as an efficient photocatalyst under UV irradiation. The photo-reduction activities of photocatalysts were evaluated using methyl orange as organic contaminant. The experiment demonstrated that the photo-degradation value of ZnO/TiO2 was significantly higher than that of ZnO.

R. Parimaladevi; K. Sumathi

2014-01-01T23:59:59.000Z

369

Ion-beam engineering of Co/TiO2 multilayer nanostructures  

Science Journals Connector (OSTI)

Multilayer structures consisting of Co/TiO2 bilayers with partial layer thicknesses varied within several nanometers and a total thickness of up to 100 nm were obtained using the ion-beam sputter deposition metho...

A. I. Stognij; M. V. Pashkevich; N. N. Novitskii

2010-05-01T23:59:59.000Z

370

Scanning tunneling microscopy investigation of the TiO2 anatase ,,101... surface Wilhelm Hebenstreit,1  

E-Print Network (OSTI)

of tunneling sites in STM. Titanium dioxide (TiO2) is a versatile material that finds uses as a promoter. Fourfold-coordinated Ti atoms at step edges are preferred adsorption sites and allow the identification

Diebold, Ulrike

371

Invoking any Intel compiler with -g defaults to -O2 optimization...  

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

Invoking any Intel compiler with a Cray wrapper with -g defaults to -O2 optimization contrary to the Intel compiler man pages Invoking any Intel compiler with a Cray wrapper with...

372

EPR Study of the Surface Characteristics of Nanostructured TiO2 under UV Irradiation  

E-Print Network (OSTI)

EPR Study of the Surface Characteristics of Nanostructured TiO2 under UV Irradiation Juan M of EPR spectroscopy. The samples of the H series present the smallest crystallite size and after

373

Oxy-coal combustion: stability of coaxial pulverized coal flames in O2/CO2 environments.  

E-Print Network (OSTI)

??Oxy-coal combustion, in which air is replaced by an O2/ CO2 mixture, is one of the few technologies that may allow CO2 capture and sequestration (more)

Zhang, Jingwei

2010-01-01T23:59:59.000Z

374

Transmission electron microscopy studies of GaN/gamma-LiAlO 2 heterostructures.  

E-Print Network (OSTI)

??Die vorliegende Arbeit beschaeftigt sich mit dem strukturellen Aufbau von (1-100) M-plane GaN, das mit plasmaunterstuetzter Molekularstrahlepitaxie auf gamma-LiAlO2(100) Substraten gewachsen wurde. Die heteroepitaktische Ausrichtung (more)

Liu, Tian-Yu

2005-01-01T23:59:59.000Z

375

Formation of O Adatom Pairs and Charge Transfer upon O-2 Dissociation...  

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

Furthermore, our results suggest that the itinerant electrons associated with the O vacancies are being utilized in the O2 dissociation process at the Ti row, whereas at least...

376

Enhanced Electrooxidation of Ethanol Using Pd/C + TiO2 Electrocatalysts in Alkaline Media  

Science Journals Connector (OSTI)

This work describes the use of Pd nanoparticles synthetized by the borohydride process and supported on physical mixtures of C + TiO2 toward the ethanol electrooxidation reaction in alkaline media. In this...2 ra...

J. C. M. Silva; G. S. Buzzo; R. F. B. De Souza; E. V. Spinac

2014-08-01T23:59:59.000Z

377

Hydrothermal ethanol conversion on Ag, Cu, Au/TiO2  

Science Journals Connector (OSTI)

The effect UV irradiation and silver, copper, and gold ions (M z+) supported on titania (anatase) have on the activity of M/TiO2 samples in ethanol conversion at 150400C is examined....2 and A...

Do Tkhyui Mai; I. I. Mikhalenko; A. I. Pylinina

2014-10-01T23:59:59.000Z

378

Photocatalytic performance of TiO2 thin films connected with Cu micro-grid  

Science Journals Connector (OSTI)

Aiming at reducing the recombination of photo-induced carriers in semiconductor photocatalytic process, we prepared TiO2...thin film with its surface modified by a connected Cu micro-grid via a microsphere lithog...

HaiLing Zhu; JunYing Zhang; TianMin Wang

2009-08-01T23:59:59.000Z

379

Porous TiO2 microspheres with tunable properties for photocatalytic air purification Alberto Naldoni a,  

E-Print Network (OSTI)

, continuous operation, facile scale-up process from small to large production, and thorough control overPorous TiO2 microspheres with tunable properties for photocatalytic air purification Alberto

Suslick, Kenneth S.

380

Comparison of the Photodesorption Activities of cis-Butene, trans-Butene and Isobutene on the Rutile TiO2(110) Surface  

SciTech Connect

The chemical and photochemical properties of three butene molecules (cis-butene, trans-butene and isobutene) were explored on the clean rutile TiO2(110) surface using temperature programmed desorption (TPD) and photon simulated desorption (PSD). At the low coverage limit, trans-butene was the most strongly bound butene on the TiO2(110) surface, desorbing at ~ 210 K, however increased intermolecular repulsions between trans-butene molecules at higher coverage diminished its binding. Both cis-butene and isobutene saturated the first layer on TiO2(110) at a coverage of ~0.50 ML in a single TPD feature at 184 and 192 K, respectively. In contrast, the maximum coverage that trans-butene could achieve in its 210 K peak was ~1/3 ML, with higher coverages resulting a low temperature desorption at ~137 K. Coverages of these molecules above 0.50 ML resulted in population of second layer and multilayer states. The instability of trans-butene at a coverage of 0.5 ML on the surface was linked to the inversion center in its symmetry. In the absence of coadsorbed oxygen, the primary photochemical pathway of each butene molecule on TiO2(110) was photodesorption. The photoactivities of these molecules on TiO2(110) at an initial coverage of 0.50 ML followed the trend: isobutene > cis-butene > trans-butene. In contrast, the photoactivities of low coverages of cis-butene and trans-butene exceeded those measured at 0.50 ML. These data suggest that intermolecular interactions (repulsions) play a significant role in diminishing the photoactivities of weakly bound molecules on TiO2 photocatalysts. Work reported here was supported by the U.S. Department of Energy, Office of Basic Energy Science, Division of Chemical Sciences, Geosciences, and Biosciences, and performed in the Williams R. Wiley Environmental Molecular Science Laboratory (EMSL), a Department of Energy user facility funded by the Office of Biological and Environmental Research. Pacific Northwest National Laboratory is a multiprogram national laboratory operated for the U.S. Department of Energy by the Battelle Memorial Institute under contract DEAC05-76RL01830.

Henderson, Michael A.

2013-11-14T23:59:59.000Z

Note: This page contains sample records for the topic "atmospheric oxygen o2" 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

Dilute Oxygen Combustion Phase I Final Report  

SciTech Connect

A novel burner, in which fuel (natural gas) and oxidant (oxygen or air) are separately injected into a furnace, shows promise for achieving very low nitrogen oxide(s) (NOx) emissions for commercial furnace applications. The dilute oxygen combustion (DOC) burner achieves very low NOx through in-furnace dilution of the oxidant stream prior to combustion, resulting in low flame temperatures, thus inhibiting thermal NOx production. The results of a fundamental and applied research effort on the development of the DOC burner are presented. In addition, the results of a market survey detailing the potential commercial impact of the DOC system are disclosed. The fundamental aspects of the burner development project involved examining the flame characteristics of a natural gas turbulent jet in a high-temperature (~1366 K) oxidant (7-27% O2 vol. wet). Specifically, the mass entrainment rate, the flame lift-off height, the velocity field and major species field of the jet were evaluated as a function of surrounding-gas temperature and composition. The measured entrainment rate of the fuel jet decreased with increasing oxygen content in the surrounding high-temperature oxidant, and was well represented by the d+ scaling correlation found in the literature. The measured flame lift-off height decreased with increasing oxygen content and increasing temperature of the surrounding gas. An increase in surrounding-gas oxygen content and/or temperature inhibited the velocity decay within the jet periphery as a function of axial distance as compared to isothermal turbulent jets. However, the velocity measurements were only broadly represented by the d+ scaling correlation. Several DOC burner configurations were tested in a laboratory-scale furnace at a nominal firing rate of 185 kW (~0.63 MMBtu/h). The flue gas composition was recorded as a function of furnace nitrogen content, furnace temperature, burner geometric arrangement, firing rate, and fuel injection velocity. NOx emissions increased with increasing furnace nitrogen content and furnace temperature, but remained relatively insensitive to variations in fuel injection velocity and firing rate. NOx emissions below 5-10-3 g/MJ (10 ppm-air equivalent at 3% O2 dry) were obtained for furnace temperatures below 1533 K (2300°F) and furnace nitrogen levels between 1 and 40%. CO emissions were typically low (<35 ppm). Detailed in-furnace species measurements revealed the importance of the interior furnace circulation patterns, as influenced by fuel and oxidant injection schemes, on pollutant emissions. The combustion stability traits of several DOC burner arrangements were ascertained through furnace pressure measurements, wit6h increased stability occurring as furnace temperature increased and as the separation distance between fuel and oxidant inputs decreased. Based on current market conditions, oxy-fuel conversion of batch steel reheat furnaces with a DOC burner is justified on the basis of lower utility costs alone. However, conversion of continuous steel reheat furnaces, which are responsible for most steel production, required additional economic incentives, such as further fuel savings, increased furnace productivity, or emission credits.

Ryan, H.M.; Riley, M.F.; Kobayashi, H.

1997-10-31T23:59:59.000Z

382

Dilute Oxygen Combustion Phase 2 Final Report  

SciTech Connect

A novel burner, in which fuel (natural gas) and oxidant (oxygen or air) are separately injected into a furnace, shows promise for achieving very low nitrogen oxide(s) (NOx) emissions for commercial furnace applications. The dilute oxygen combustion (DOC) burner achieves very low NOx through in-furnace dilution of the oxidant stream prior to combustion, resulting in low flame temperatures, thus inhibiting thermal NOx production. The results of a fundamental and applied research effort on the development of the DOC burner are presented. In addition, the results of a market survey detailing the potential commercial impact of the DOC system are disclosed. The fundamental aspects of the burner development project involved examining the flame characteristics of a natural gas turbulent jet in a high-temperature (~1366 K) oxidant (7-27% O2 vol. wet). Specifically, the mass entrainment rate, the flame lift-off height, the velocity field and major species field of the jet were evaluated as a function of surrounding-gas temperature and composition. The measured entrainment rate of the fuel jet decreased with increasing oxygen content in the surrounding high-temperature oxidant, and was well represented by the d+ scaling correlation found in the literature. The measured flame lift-off height decreased with increasing oxygen content and increasing temperature of the surrounding gas. An increase in surrounding-gas oxygen content and/or temperature inhibited the velocity decay within the jet periphery as a function of axial distance as compared to isothermal turbulent jets. However, the velocity measurements were only broadly represented by the d+ scaling correlation. Several DOC burner configurations were tested in a laboratory-scale furnace at a nominal firing rate of 185 kW (~0.63 MMBtu/h). The flue gas composition was recorded as a function of furnace nitrogen content, furnace temperature, burner geometric arrangement, firing rate, and fuel injection velocity. NOx emissions increased with increasing furnace nitrogen content and furnace temperature, but remained relatively insensitive to variations in fuel injection velocity and firing rate. NOx emissions below 5-10-3 g/MJ (10 ppm-air equivalent at 3% O2 dry) were obtained for furnace temperatures below 1533 K (2300?F) and furnace nitrogen levels between 1 and 40%. CO emissions were typically low (<35 ppm). Detailed in-furnace species measurements revealed the importance of the interior furnace circulation patterns, as influenced by fuel and oxidant injection schemes, on pollutant emissions. The combustion stability traits of several DOC burner arrangements were ascertained through furnace pressure measurements, wit6h increased stability occurring as furnace temperature increased and as the separation distance between fuel and oxidant inputs decreased. Based on current market conditions, oxy-fuel conversion of batch steel reheat furnaces with a DOC burner is justified on the basis of lower utility costs alone. However, conversion of continuous steel reheat furnaces, which are responsible for most steel production, required additional economic incentives, such as further fuel savings, increased furnace productivity, or emission credits.

Ryan, H.M.; Riley, M.F.; Kobayashi, H.

2005-09-30T23:59:59.000Z

383

Electrochemical evaluation of LiCoO2 synthesized by decomposition and intercalation of hydroxides  

E-Print Network (OSTI)

in commercial lithi- um-ion battery manufacturing [4±6]. Synthesis of LiCoO2 is typically carried out by a solid-state March 1998; accepted in revised form 19 May 1998 LiCoO2 has been synthesized by a solid-state synthesis the electrochemical perfor- mance. In a previous paper [13], we reported a new solid- state reaction method that can

Sadoway, Donald Robert

384

Understanding of catalytic behaviors of TiO2/CuOx catalysts  

SciTech Connect

Aiming to reveal the catalysis at the metal-oxide and oxide-oxide interfaces,1,2 the water-gas shift reaction (WGS, CO + H2O and #61664; CO2 + H2) and CO oxidation (2CO + O2 and #61664; 2CO2) at the interface of the Cu(111) and Cu2O(111) supported TiO2 clusters were studied based on DFT calculations

Kim H. Y.; Liu, P.

2013-09-08T23:59:59.000Z

385

Factors Affecting UV-Induced Superhydrophilic Conversion of a TiO2 Surface  

Science Journals Connector (OSTI)

Factors Affecting UV-Induced Superhydrophilic Conversion of a TiO2 Surface ... Particularly, the maximum extrema in spectral dependence of the efficiency of photoinduced hydrophilic conversion correspond to the energies of the first indirect and first direct electronic band-to-band transitions in TiO2. ... To estimate the efficiency of the photoinduced surface hydrophilic conversion, we used two parameters: initial rate of contact angle alteration and initial rate of surface energy alteration. ...

Alexei V. Emeline; Aida V. Rudakova; Munetoshi Sakai; Taketoshi Murakami; Akira Fujishima

2013-05-17T23:59:59.000Z

386

Weird Oxygen Bonding under Pressure | Advanced Photon Source  

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

A Breakthrough in Improving Osteoporosis Drug Design A Breakthrough in Improving Osteoporosis Drug Design Allaying Structural-Alloy Corrosion Putting the Pressure on MOFs Newly Described "Dragon" Protein Could Be Key to Bird Flu Cure Hearing the Highest Pitches Science Highlights Archives: 2013 | 2012 | 2011 | 2010 2009 | 2008 | 2007 | 2006 2005 | 2004 | 2003 | 2002 2001 | 2000 | 1998 | Subscribe to APS Science Highlights rss feed Weird Oxygen Bonding under Pressure AUGUST 8, 2008 Bookmark and Share Schematic shows the topology of π* orbital interactions in the (O2)4 cluster. (Image copyright National Academy of Sciences, PNAS.) Oxygen, the third most abundant element in the cosmos and essential to life on Earth, changes its forms dramatically under pressure, transforming to a solid with spectacular colors. Eventually it becomes metallic and a

387

The oxygen emission lines in Wolf-Rayet spectra  

SciTech Connect

The statistical equilibrium of oxygen in the line-emitting regions of WR stars is studied using the one-representative point theory of Castor and van Blerkom (1970) for a wider range of the radiation temperature, electron temperature, and electron density. Radiative processes, collisional processes, and electronic recombination are studied for a 59-level model atom. The level populations depart by large factors from those expected for LTE at the electron temperature and electron density. When the parameters have the values found previously by Bhatia and Underhill to be representative for WR stars, the oxygen atoms are strongly concentrated in the lower levels of O(2+), O(3+), and O(4+). The predicted relative energies in typical lines of O III, O IV, and O V for a solar abundance ratio of O to H are compatible with what is observed in WC and WN spectra. 47 refs.

Bhatia, A.K.; Underhill, A.B. (NASA, Goddard Space Flight Center, Greenbelt, MD (USA) British Columbia Univ., Vancouver (Canada))

1990-07-01T23:59:59.000Z

388

Visible-Light Responsive Photocatalytic Fuel Cell Based on Ag/TiO2-NTs Photoanode and Cu2O/TiO2 Photocathode for Simultaneous Wastewater Treatment and Electricity Generation  

Science Journals Connector (OSTI)

A visible-light driven photocatalytic fuel cell (PFC) system comprised of Ag/TiO2-NTs photoanode and Cu2O/TiO2/Ti photocathode was established for providing a self-sustained and...

Liao, Wenjuan

389

Effect of TiO2 Content on Ethanol Electrooxidation in Alkaline Media Using Pt Nanoparticles Supported on Physical Mixtures of Carbon and TiO2 as Electrocatalysts  

Science Journals Connector (OSTI)

Pt nanoparticles supported on physical mixtures of carbon and TiO2 (Pt/(C?+?TiO2) electrocatalyst) were tested for ethanol electrooxidation in alkaline media. The electrocatalysts were...2 mass ratios using boroh...

R. F. B. De Souza; G. S. Buzzo; J. C. M. Silva; E. V. Spinac

2014-04-01T23:59:59.000Z

390

Results from ORNL characterization of ZrO2-500-AK2 - surrogate TRISO material  

SciTech Connect

This document is a compilation of the characterization data for the TRISO-coated surrogate particles designated ZrO2-500-AK2 that was produced at Oak Ridge National Laboratory (ORNL) as part of the Advanced Gas Reactor Fuel Development and Qualification (AGR) program. The ZrO2-500-AK2 material contains nominally 500 {micro}m kernels of yttria-stabilized zirconia (YSZ) coated with all TRISO layers (buffer, inner pyrocarbon, silicon carbide, and outer pyrocarbon). The ZrO2-500-AK2 material was created for: (1) irradiation testing in the High Flux Isotope Reactor (HFIR) and (2) limited dissemination to laboratories as deemed appropriate to the AGR program. This material was created midway into a TRISO fuel development program to accommodate a sudden opportunity to perform irradiation testing on surrogate material. While the layer deposition processes were chosen based on the best technical understanding at the time, technical progress at ORNL has led to an evolution in the perceived optimal deposition conditions since the creation of ZrO2-500-AK2. Thus, ZrO2-500-AK2 contains a reasonable TRISO microstructure, but does differ significantly from currently produced TRISO surrogates and fuel at ORNL. In this document, characterization data of the ZrO2-500-AK2 surrogate includes: size, shape, coating thickness, and density.

Kercher, Andrew K [ORNL; Hunn, John D [ORNL

2005-06-01T23:59:59.000Z

391

Heterogeneous Oxidation of Carbonyl Sulfide on Atmospheric Particles and Alumina  

Science Journals Connector (OSTI)

The specifications of gases used in this experiment are as follows without further purification:? OCS (2%, OCS/N2, Scott Specialty Gases Inc.), O2 (99.99% purity, Beijing AP BEIFEN Gases Inc.), H2 (99.999% purity, GCD-300B high purity hydrogen generator, China Bchp Analytical Technology Co. Ltd.). ... To confirm our assignment about the surface SO42- species, 1.0 g of preoxidized Al2O3 sample after exposure to a flow of 500 ppm OCS + 95% O2 at 298 K for 2 h was analyzed by ion chromatography (DIONEX, CA); 2.43 mg/L SO42- can be detected (sample stirred with 100 mL deionized water, and then filtered through a 0.45-?m filter). ... Since the real atmospheric particle sample has relatively high surface area (4.8 m2/g), its influence on the conversion of OCS in atmosphere is not neglectable. ...

Hong He; Junfeng Liu; Yujing Mu; Yunbo Yu; Meixue Chen

2005-11-05T23:59:59.000Z

392

Mineralization of Basalts in the CO2-H2O-SO2-O2 System. | EMSL  

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

SO2-O2 System. Mineralization of Basalts in the CO2-H2O-SO2-O2 System. Abstract: Sequestering carbon dioxide (CO2) containing minor amounts of co-contaminants in geologic...

393

Preparation of TiO2(110)-(1x1) Surface via UHV Cleavage: An scanning...  

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

Preparation of TiO2(110)-(1x1) Surface via UHV Cleavage: An scanning tunneling microscopy study. Preparation of TiO2(110)-(1x1) Surface via UHV Cleavage: An scanning tunneling...

394

TiO2 nanoparticles on nitrogen-doped graphene as anode material for lithium ion batteries  

Science Journals Connector (OSTI)

Anatase TiO2...nanoparticles in situ grown on nitrogen-doped, reduced graphene oxide (rGO) have been successfully synthesized ... as an anode material for the lithium ion battery. The nanosized TiO2 particles wer...

Dan Li; Dongqi Shi; Zongwen Liu; Huakun Liu

2013-04-01T23:59:59.000Z

395

Atomic Layer Deposition of TiO2 on Aerogel Templates: New Photoanodes for Dye-Sensitized Solar Cells  

Science Journals Connector (OSTI)

Atomic layer deposition was employed to coat the aerogel template conformally with various thicknesses of TiO2 with subnanometer precision. ... The TiO2-coated aerogel membranes were incorporated as photoanodes in dye-sensitized solar cells. ...

Thomas W. Hamann; Alex B. F. Martinson; Jeffrey W. Elam; Michael J. Pellin; Joseph T. Hupp

2008-06-18T23:59:59.000Z

396

A VUV photoionization measurement and ab-initio calculation of the ionization energy of gas phase SiO2  

E-Print Network (OSTI)

g [O-Si-O] + . Electronic structure calculations aid in thewith CO 2 . Electronic structure calculations were performedSiO 2 PIE. Electronic structure calculations on SiO 2 and

Kostko, Oleg

2010-01-01T23:59:59.000Z

397

Atmospheric Transport of Radionuclides  

SciTech Connect

The purpose of atmospheric transport and diffusion calculations is to provide estimates of concentration and surface deposition from routine and accidental releases of pollutants to the atmosphere. This paper discusses this topic.

Crawford, T.V.

2003-03-03T23:59:59.000Z

398

The Boulder Atmospheric Observatory  

Science Journals Connector (OSTI)

The Boulder Atmospheric Observatory (BAO) is a unique research facility for studying the planetary boundary layer and for testing and calibrating atmospheric sensors. The facility includes a 300 m tower instrumented with fast- and slow-response ...

J. C. Kaimal; J. E. Gaynor

1983-05-01T23:59:59.000Z

399

Structural and magnetic properties of Y0.33Sr0.67CoO2.79  

Science Journals Connector (OSTI)

The perovskite-based oxide Y0.33Sr0.67CoO2.79 has been magnetically and structurally characterized. The material shows a unit cell of 224 simple perovskite cubes with space group I4/mmm. This is a different structure to that observed in the much-studied (La,Sr)CoO3 oxides. Oxygen stoichiometry is established through thermogravimetric analysis and correlated with ac and dc magnetic measurements and magnetic neutron diffraction. Hysteresis with field and temperature is observed in the dc magnetization measurements, yet the absence of an imaginary component in the ac susceptibility suggests a time-independent cause for these effects such as the presence of independently ordering ferromagnetic regions due to compositional inhomogeneities within the (single-phase) sample. Rietveld magnetic refinements suggest that the Co moments are arranged antiferromagnetically below 320 K, with the ferromagnetic regions existing within the long-range ordered antiferromagnetic matrix. The staggered moments are (anti)parallel with the c axis and of magnitude 2?B, a moment most typical of intermediate spin Co3+. The material does not enter a spin glass or cluster glass phase, but appears to undergo a broad spin-state transition below 100 K.

D. J. Goossens; K. F. Wilson; M. James; A. J. Studer; X. L. Wang

2004-04-06T23:59:59.000Z

400

Development of Compact Gaseous Sensors with Internal Reference for Monitoring O2 and NOx in Combustion Environments  

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

Compact sensors have been developed to allow for real-time monitoring of O2 and NOx during combustion.

Note: This page contains sample records for the topic "atmospheric oxygen o2" 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

Comparison of Ag and SiO2 Nanoparticles for Light Trapping Applications in Silicon Thin Film Solar Cells  

Science Journals Connector (OSTI)

Comparison of Ag and SiO2 Nanoparticles for Light Trapping Applications in Silicon Thin Film Solar Cells ... Department

Martin Theuring; Peng Hui Wang; Martin Vehse; Volker Steenhoff; Karsten von Maydell; Carsten Agert; Alexandre G. Brolo

2014-09-10T23:59:59.000Z

402

Stabilization of Platinum Nanoparticle Electrocatalysts for Oxygen...  

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

Platinum Nanoparticle Electrocatalysts for Oxygen Reduction Using Poly(diallyldimethylammonium chloride). Stabilization of Platinum Nanoparticle Electrocatalysts for Oxygen...

403

PHYSICAL REVIEW B 84, 245206 (2011) First-principles study of band gap engineering via oxygen vacancy doping  

E-Print Network (OSTI)

formulate guidelines that can be used to predict the location of oxygen vacancies in perovskite solid transport of O2- ions through the oxide electrolyte membrane over a range of temperatures. In solar energy several chemical compositions and different cation arrangements for the two Zr-modified solid solutions

Rappe, Andrew M.

404

TiO2-Coated Ultrathin SnO2 Nanosheets Used as Photoanodes for Dye-Sensitized Solar Cells with High Efficiency  

Science Journals Connector (OSTI)

According to the EIS model, the lifetime of electrons in the oxide film (?r) can be estimated from the maximum angular frequency (?max) of the impedance semicircle arc at middle frequencies in the Bode spectrum. ... Zn stannate can be an interesting mesoporous material for DSSC, provided dyes are used which have a higher position of the LUMO compared to that of N719, as it will permit attaining higher photovoltages without affecting the photocurrent. ... The power conversion efficiency (6.40%) of dye-sensitized solar cell based on hierarchical SnO2 octahedra which has a 23% increase compared with that of SnO2 nanoparticle photoelectrode (5.21%) is mainly ascribed to the efficient light scattering for the former, which is further confirmed by the UV/visible reflectance spectra. ...

Jun Xing; Wen Qi Fang; Zhen Li; Hua Gui Yang

2012-02-28T23:59:59.000Z

405

8, 10691088, 2008 Atmospheric  

E-Print Network (OSTI)

into the atmosphere (Molina et al., 1974; Farman et al., 1985) has led to an interna- tional effort to replace

Boyer, Edmond

406

SUPPORTED DENSE CERAMIC MEMBRANES FOR OXYGEN SEPARATION  

SciTech Connect

Mixed-conducting membranes have the ability to conduct oxygen with perfect selectivity at elevated temperatures, which makes them an extremely attractive alternative for oxygen separation and membrane reactor applications. The ability to reliably fabricate these membranes in thin or thick films would enable solid-state divisional limitations to be minimized, thus providing higher oxygen flux. Based on that motivation, the overall objective for this project is to develop and demonstrate a strategy for the fabrication of supported Wick film ceramic mixed conducting membranes, and improve the understanding of the fundamental issues associated with reliable fabrication of these membranes. The project has focused on the mixed-conducting ceramic composition SrCo{sub 0.5}FeO{sub x} because of its superior permeability and stability in reducing atmospheres. The fabrication strategy employed involves the deposition of SrCo{sub 0.5}FeO{sub x} thick films onto porous supports of the same composition. In the second year of this project, we completed characterization of the sintering and phase behavior of the porous SrCo{sub 0.5}FeO{sub x} supports, leading to a standard support fabrication methodology. Using a doctor blade method, pastes made from aerosol-derived SrCo{sub 0.5}FeO{sub x} powder dispersed with polyethylene glycol were applied to the supports, and the sintering behavior of the thick film membranes was examined in air and nitrogen atmospheres. It has been demonstrated that the desired crystalline phase content can be produced in the membranes, and that the material in the membrane layer can be highly densified without densifying the underlying support. However, considerable cracking and opening of the film occurred when films densified to a high extent. The addition of MgO into the SrCo{sub 0.5}FeO{sub x} supports was shown to inhibit support sintering so that temperatures up to 1300 C, where significant liquid formation occurs, could be used for film sintering. This successfully reduced cracking, however the films retained open porosity. The investigation of this concept will be continued in the final year of the project. Investigation of a metal organic chemical vapor deposition (MOCVD) method for defect mending in dense membranes was also initiated. An appropriate metal organic precursor (iron tetramethylheptanedionate) was identified whose deposition can be controlled by access to oxygen at temperatures in the 280-300 C range. Initial experiments have deposited iron oxide, but only on the membrane surface; thus refinement of this method will continue.

Timothy L. Ward

2000-06-30T23:59:59.000Z

407

CdS quantum dot sensitized nanocrystalline Gd-doped TiO2 thin films for photoelectrochemical solar cells  

Science Journals Connector (OSTI)

CdS quantum dot sensitized Gd-doped TiO2 nanocrystalline thin films have been prepared by chemical method. X-ray diffraction analysis reveals that TiO2 and Gd-doped TiO2...nanocrystalline thin films are of anatas...

A. Ranjitha; N. Muthukumarasamy

2013-08-01T23:59:59.000Z

408

Preparation of Al2O3/TiO2-containing Coating on Aluminium Alloys by Micro-arc Oxidation  

Science Journals Connector (OSTI)

TiO2-containing ceramic coatings were deposited on the surface of aluminium alloys by micro-arc oxidition. Surface and cross-section topograph of ceramic coating were observed using scanning electron microscopy (SEM). The phase composition of ceramic ... Keywords: Micro-arc oxidation, TiO2 additive, Al2O3/TiO2 phase, antiwear behavior

Cheng Gao; Jinyong Xu; Yusheng Lan; Yonghui Ma; Weixiang Su; Yajuan Liu

2010-03-01T23:59:59.000Z

409

Argon metastable densities in radio frequency Ar, Ar/O2 and Ar/CF4 electrical discharges  

E-Print Network (OSTI)

Argon metastable densities in radio frequency Ar, Ar/O2 and Ar/CF4 electrical discharges Shahid. In this article, we present results from a two-dimensional computer simulation of Ar, Ar/O2, and Ar/CF4 discharges in the ambipolar electric field resulting from electrode structures. Additions of small amounts of O2 and CF4

Kushner, Mark

410

Synthesis and structure of Al clusters supported on TiO2,,110...: A scanning tunneling microscopy study  

E-Print Network (OSTI)

Synthesis and structure of Al clusters supported on TiO2,,110...: A scanning tunneling microscopy, Texas 77843-3255 Received 14 October 1997; accepted 6 April 1998 Al clusters supported on TiO2(110) have been investigated using scanning tunneling microscopy. Al interacts strongly with the TiO2(110) surface

Goodman, Wayne

411

Anodic bonding of glass-ceramics to stainless steel coated with intermediate SiO2 layer  

Science Journals Connector (OSTI)

The anodic bonding between glass-ceramics and stainless steel (No. 430#) which was coated with SiO"2 layer were investigated. The SiO"2 layers with thickness comprised between 150 and 250nm were coated on stainless steel surfaces by sol-gel method, the ... Keywords: Anodic bonding, Glass-ceramics, Intermediate layer, SiO2, Stainless steel

Dehua Xiong; Jinshu Cheng; Hong Li; Wei Deng; Kai Ye

2010-11-01T23:59:59.000Z

412

Observations of O2:CO2 exchange ratios during ecosystem gas W. A. Brand, M. Heimann, and J. Lloyd2  

E-Print Network (OSTI)

and respiration, thermal ingassing and outgassing of O2 in ocean water, and combustion of fossil fuels and biomass than would be expected from fossil fuel combustion. This implies that the terrestrial biosphere has combustion consumes O2 and produces CO2 with exchange ratios (defined here as ?D[O2]/D[CO2]) varying from

413

The Upper Atmosphere Observatory  

Science Journals Connector (OSTI)

...with *the plasma frethe progress...explorcreated an even larger number of...the upper atmosphere and ionosphere...the upper atmosphere. For this...ionospheric plasma motion simul-taneously...field is large, the horizontal...resolved. The atmospheric gravity waves...simul-taneously at a large number of...two regions plasma drifts separated...

J. V. Evans

1972-05-05T23:59:59.000Z

414

The Upper Atmosphere Observatory  

Science Journals Connector (OSTI)

...DATA, JOURNAL OF ATMOSPHERIC AND TERRESTRIAL...IN NEAR-EARTH PLASMA, SPACE SCIENCE...INVESTIGATION OF WHISTLING ATMOSPHERICS, PHILOSOPHICAL...TRANSPOLAR EXOSPHERIC PLASMA .1. PLASMASPHERE...dynamics of the upper atmosphere. For this purpose...the ionospheric plasma motion simul-taneously...

J. V. Evans

1972-05-05T23:59:59.000Z

415

5, 60416076, 2005 Atmospheric  

E-Print Network (OSTI)

opportunity to examine atmospheric oxidation in a megacity that has more pollution than typical USACPD 5, 6041­6076, 2005 Atmospheric oxidation in the Mexico City Metropolitan Area T. R. Shirley et.atmos-chem-phys.org/acpd/5/6041/ SRef-ID: 1680-7375/acpd/2005-5-6041 European Geosciences Union Atmospheric Chemistry

Boyer, Edmond

416

Composite oxygen transport membrane  

DOE Patents (OSTI)

A method of producing a composite oxygen ion membrane and a composite oxygen ion membrane in which a porous fuel oxidation layer and a dense separation layer and optionally, a porous surface exchange layer are formed on a porous support from mixtures of (Ln.sub.1-xA.sub.x).sub.wCr.sub.1-yB.sub.yO.sub.3-.delta. and a doped zirconia. In the porous fuel oxidation layer and the optional porous surface exchange layer, A is Calcium and in the dense separation layer A is not Calcium and, preferably is Strontium. Preferred materials are (La.sub.0.8Ca.sub.0.2).sub.0.95Cr.sub.0.5Mn.sub.0.5O.sub.3-.delta. for the porous fuel oxidation and optional porous surface exchange layers and (La.sub.0.8Sr.sub.0.2).sub.0.95Cr.sub.0.5Fe.sub.0.5O.sub.3-.delta. for the dense separation layer. The use of such materials allows the membrane to sintered in air and without the use of pore formers to reduce membrane manufacturing costs. The use of materials, as described herein, for forming the porous layers have application for forming any type of porous structure, such as a catalyst support.

Christie, Gervase Maxwell; Lane, Jonathan A.

2014-08-05T23:59:59.000Z

417

OXYGEN ABUNDANCES IN CEPHEIDS  

SciTech Connect

Oxygen abundances in later-type stars, and intermediate-mass stars in particular, are usually determined from the [O I] line at 630.0 nm, and to a lesser extent, from the O I triplet at 615.7 nm. The near-IR triplets at 777.4 nm and 844.6 nm are strong in these stars and generally do not suffer from severe blending with other species. However, these latter two triplets suffer from strong non-local thermodynamic equilibrium (NLTE) effects and thus see limited use in abundance analyses. In this paper, we derive oxygen abundances in a large sample of Cepheids using the near-IR triplets from an NLTE analysis, and compare those abundances to values derived from a local thermodynamic equilibrium (LTE) analysis of the [O I] 630.0 nm line and the O I 615.7 nm triplet as well as LTE abundances for the 777.4 nm triplet. All of these lines suffer from line strength problems making them sensitive to either measurement complications (weak lines) or to line saturation difficulties (strong lines). Upon this realization, the LTE results for the [O I] lines and the O I 615.7 nm triplet are in adequate agreement with the abundance from the NLTE analysis of the near-IR triplets.

Luck, R. E.; Andrievsky, S. M. [Department of Astronomy, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106-7215 (United States); Korotin, S. N.; Kovtyukh, V. V., E-mail: luck@fafnir.astr.cwru.edu, E-mail: serkor@skyline.od.ua, E-mail: val@deneb1.odessa.ua, E-mail: scan@deneb1.odessa.ua [Department of Astronomy and Astronomical Observatory, Odessa National University, Isaac Newton Institute of Chile, Odessa Branch, Shevchenko Park, 65014 Odessa (Ukraine)

2013-07-01T23:59:59.000Z

418

Probing The Electrode/Electrolyte Interface in The Lithium Excess Layered Oxide Li1.2Ni0.2Mn0.6O2  

SciTech Connect

A detailed surface investigation of the lithium-excess nickel manganese layered oxide Li1.2Ni0.2Mn0.6O2 structure was carried out using x-ray photoelectron spectroscopy (XPS), total electron yield and transmission x-ray absorption spectroscopy (XAS), and electron energy loss spectroscopy (EELS) during the first two electrochemical cycles. All spectroscopy techniques consistently showed the presence of Mn4+ in the pristine material and a surprising reduction of Mn at the voltage plateau during the first charge. The Mn reduction is accompanied by the oxygen loss revealed by EELS. Upon the first discharge, the Mn at the surface never fully returns back to Mn4+. The electrode/electrolyte interface of this compound consists of the reduced Mn at the crystalline defect-spinel inner layer and an oxidized Mn species simultaneously with the presence of a superoxide species in amorphous outer layer. This proposed model signifies that oxygen vacancy formation and lithium removal result in electrolyte decomposition and superoxide formation, leading to Mn activation/dissolution and surface layer-spinel phase transformation. The results also indicate that the role of oxygen is complex and significant in contributing to the extra capacity of this class of high energy density cathode materials.

Carroll, Kyler J [University of California, San Diego; Qian, Danna [University of California, San Diego; Fell, Chris [University of Florida, Gainesville; Calvin, Scott [Sarah Lawrence College; Veith, Gabriel M [ORNL; Chi, Miaofang [ORNL; Dudney, Nancy J [ORNL; Meng, Ying Shirley [University of California, San Diego

2013-01-01T23:59:59.000Z

419

Magnetic properties of epitaxial Co-doped anatase TiO2 thin films...  

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

point defects present in the bulk material, such as charge-compensating oxygen vacancies, but is instead attributed to the presence of extended structural defects. Citation:...

420

Photochemistry of 1,1,1-Trifluoroacetone on Rutile TiO2(110)...  

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

functional theory (DFT). TFA adsorbed molecularly on the reduced surface (8% oxygen vacancies) in states desorbing below 300 K with trace thermal decomposition observed in TPD....

Note: This page contains sample records for the topic "atmospheric oxygen o2" 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

Structure of epitaxial (Fe,N) codoped rutile TiO2 thin films...  

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

No evidence of structural disorder associated with a high concentration of oxygen vacancies is observed. Substitution of Fe for Ti could not be confirmed, although secondary...

422

Preparation and properties of Al-PILC supported SO42?/TiO2 superacid catalyst  

Science Journals Connector (OSTI)

SO42?/TiO2/Al-pillared clay (ST/Al-PILC) superacid catalyst was prepared by loading active component SO42?/TiO2 on Al-pillared clay. The texture structure properties of the catalyst were studied by means of X-ray powder diffraction and the adsorption of N2. Acidity properties of the catalyst were tested by Hammett indicator method and FT-IR spectra of absorbed pyridine technique. The characterization results indicated that Al-PILC carrier could inhibit the formation of anatase TiO2 and the transformation of anatase TiO2 into rutile TiO2. ST/Al-PILC catalyst possesses both Lewis and Brnsted acid sites, and the number of acid sites on ST/Al-PILC is much larger than that on Al-PILC carrier, but its acid strength is lower than that of ST. Experimental results show that ST/Al-PILC is an effective catalyst for esterification of n-pentanol with benzoic acid.

Yue-Xiu Jiang; Xiao-Mei Chen; Yun-Fen Mo; Zhang-Fa Tong

2004-01-01T23:59:59.000Z

423

On The Importance of Organic Oxygen for Understanding Organic Aerosol  

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

On The Importance of Organic Oxygen for Understanding Organic Aerosol On The Importance of Organic Oxygen for Understanding Organic Aerosol Particles Title On The Importance of Organic Oxygen for Understanding Organic Aerosol Particles Publication Type Journal Article Year of Publication 2006 Authors Pang, Yanbo, B. J. Turpin, and Lara A. Gundel Journal Journal of Aerosol Science and Technology Volume 40 Start Page Chapter Pagination 128-133 Abstract This study shows how aerosol organic oxygen data could provide new and independent information about organic aerosol mass, aqueous solubility of organic aerosols, formation of secondary organic aerosol (SOA) and the relative contributions of anthropogenic and biogenic sources. For more than two decades atmospheric aerosol organic mass concentration has usually been estimated by multiplying the measured carbon content by an assumed organic mass (OM)-to-organic carbon (OC ) factor of 1.4. However, this factor can vary from 1.0 to 2.5 depending on location. This great uncertainty about aerosol organic mass limits our understanding of the influence of organic aerosol on climate, visibility and health.New examination of organic aerosol speciation data shows that the oxygen content is the key factor responsible for the observed range in the OM-to-OC factor. When organic oxygen content is excluded, the ratio of non-oxygen organic mass to carbon mass varies very little across different environments (1.12 to 1.14). The non-oxygen-OM-to-non-oxygen OC factor for all studied sites (urban and non-urban) is 1.13± 0.02. The uncertainty becomes an order of magnitude smaller than the uncertainty in the best current estimates of organic mass to organic carbon ratios (1.6± 0.2 for urban and 2.1± 0.2 for non-urban areas). When aerosol organic oxygen data become available, organic aerosol mass can be quite accurately estimated using just OC and organic oxygen (OO) without the need to know whether the aerosol is fresh or aged. In addition, aerosol organic oxygen data will aid prediction of water solubility since compounds with OO-to-OC higher than 0.4 have water solubilities higher than 1g per 100 g water

424

Time Resolved in Situ XAFS Study of the Electrochemical Oxygen Intercalation in SrFeO2.5 Brownmillerite Structure: Comparison with the Homologous SrCoO2.5 System  

E-Print Network (OSTI)

as electrodes in solid oxide fuel cells (SOFCs) or batteries,1-12 sensors,13-16 magnetic recording,17 membranes fuel cells. In this regard, SrMO2.5 (M ) Fe,Co) systems with a Brownmillerite-type structure are able and batteries, a huge scientific work was performed in the past decade in order to understand the problems

Frenkel, Anatoly

425

BWR oxygen control demonstration program  

SciTech Connect

A number of cracks have occurred recently in certain BWR piping systems. The operating environment associated with oxidizing species such as oxygen and hydrogen peroxide is considered one of the factors in the mechanism of cracking. In April 1976, NWT Corporation was contracted to perform a BWR oxygen control demonstration program. Means for reducing reactor water oxygen and hydrogen peroxide concentrations during startup and shutdown transients were defined and demonstrated at Vermont Yankee and Browns Ferry Unit 3. Results of the demonstrations and an analytical review of impacts of major system variables on oxygen transients are discussed herein.

Pearl, W.L.; Kassen, W.R.; Sawochka, S.G.

1981-05-01T23:59:59.000Z

426

Mechanism for Oxygen Reduction Reaction on Pt3Ni Alloy Fuel Cell Cathode  

Science Journals Connector (OSTI)

The efficiency of the oxygen reduction reaction (ORR), 4H+ + 4e + O2 ? 2H2O, at the cathode of a polymer electrolyte membrane fuel cell (PEMFC) is a critical issue for commercial application of this type of fuel cells. ... This agrees with the volcano-like trend for ORR catalysts,(7, 31, 32) when the activity first increases and then decreases as the catalyst d-band center shifts downward. ... Improved Non-Pt Alloys for the Oxygen Reduction Reaction at Fuel Cell Cathodes Predicted from Quantum Mechanics ...

Yao Sha; Ted H. Yu; Boris V. Merinov; Pezhman Shirvanian; William A. Goddard; III

2012-09-04T23:59:59.000Z

427

Pool octanes via oxygenates  

SciTech Connect

Increasingly stringent antipollution regulations placed on automobile exhaust gases with consequent reduction or complete lead ban from motor gasoline result in octane shortage at many manufacturing sites. Attractive solutions to this problem, especially in conjunction with abundant methanol supplies, are the hydration and etherification of olefins contained in light product streams from cracking unit or produced by field gas dehydrogenation. A comparison is made between oxygenates octane-volume pool contributions and established refinery technologies. Process reviews for bulk manufacture of fuel-grade isopropanol (IPA), secondary butanol (SBA), tertiary butanol (TBA), methyl tertiary butyl ether (MTBE) and tertiary amyl methyl ether (TAME) are presented together with the characteristic investment and operating data. The implantation of these processes into a typical FCCU refinery complex with the resulting octane-pool improvement possibilities is descried.

Prezelj, M.

1987-09-01T23:59:59.000Z

428

Impact of active material surface area on thermal stability of LiCoO2 cathode  

Science Journals Connector (OSTI)

Abstract Thermal stability of charged LiCoO2 cathodes with various surface areas of active material is investigated in order to quantify the effect of LiCoO2 surface area on thermal stability of cathode. Thermogravimetric analyses and calorimetry have been conducted on charged cathodes with different active material surface areas. Besides reduced thermal stability, high surface area also changes the active material decomposition reaction and induces side reactions with additives. Thermal analyses of LiCoO2 delithiated chemically without any additives or with a single additive have been conducted to elaborate the effect of particle size on side reactions. Stability of cathodeelectrolyte system has been investigated by accelerating rate calorimetry (ARC). Arrhenius activation energy of cathode decomposition has been calculated as function of conversion at different surface area of active material.

Jan Geder; Harry E. Hoster; Andreas Jossen; Jrgen Garche; Denis Y.W. Yu

2014-01-01T23:59:59.000Z

429

Functionalization of Biomass Carbonaceous Aerogels: Selective Preparation of MnO2@CA Composites for Supercapacitors  

Science Journals Connector (OSTI)

In this work, we present a facile and scalable method to synthesize MnO2 loaded carbonaceous aerogel (MnO2@CA) composites via the hydrothermal carbonaceous (HTC) process. ... Carbon-based materials have received the most attention for their remarkable and unusual physicochemical properties, motivated by their potential importance in separation science, heterogeneous catalyst supports, and water purification filters, and as well as the developing areas of energy generation and storage. ... The obtained samples were filtered, washed several times with deionized water and dehydrated alcohol to remove impurities and excess ions, and then dried in air at 60 C for 24 h. ...

Yumei Ren; Qun Xu; Jianmin Zhang; Hongxia Yang; Bo Wang; Daoyuan Yang; Junhua Hu; Zhimin Liu

2014-06-02T23:59:59.000Z

430

Electronic Structure and Optical Properties of AFeO2 (A = Ag, Cu) within GGA Calculations  

Science Journals Connector (OSTI)

Electronic Structure and Optical Properties of AFeO2 (A = Ag, Cu) within GGA Calculations ... The electronic structure of delafossite type oxides AFeO2 (A = Ag, Cu) has been calculated using the full potential linearized augmented plane wave (FP-LAPW) method within the local spin density approximation (LSDA), Perdew?Burke?Ernzerhof (PBE-GGA), and Engel?Vosko (EV-GGA) generalized-gradient approximations. ... The effective Hubbard U, Ueff, has been derived on the basis of an ab initio constraint calculation and by comparison with X-ray emission spectra. ...

Khuong P. Ong; Kewu Bai; Peter Blaha; Ping Wu

2007-01-06T23:59:59.000Z

431

Fouling and Corrosion Properties of SiO2 Coatings on Copper in Geothermal Water  

Science Journals Connector (OSTI)

The main goal of this work was to explore the antifouling and anticorrosion characteristics of LPD-prepared low-energy inorganic SiO2 coatings on copper substrates with nanometer-scale film thicknesses in low- and medium-temperature geothermal waters, as no open literature could be found in this area. ... SiO2 films on substrates of Si wafer, glass, gallium arsenide, and SiGe, among others, have been successfully obtained with the LPD method. ... Stathoulopoulou, A.; Demadis, K. D.Enhancement of silicate solubility by use of green additives: Linking green chemistry and chemical water treatment Desalination 2008, 224, 223 ...

Chen Ning; Liu Mingyan; Zhou Weidong

2012-04-02T23:59:59.000Z

432

Evidence for a wide continuum of polymorphs in a-SiO2  

Science Journals Connector (OSTI)

The irradiations of vitreous amorphous silica with subband-gap laser radiation at 248 nm induces reversible-irreversible compaction. The former is consistent with the creation of a wide continuum of densified amorphous silica (a-SiO2) polymorphs whilst the second stage corresponds to the ablation through laser radiation of the damaged a-SiO2. These observations are discussed in terms of conformational structure modifications (i.e., changes in the distribution of planar rings) and stable superficial defect creation.

C. Fiori and R. A. B. Devine

1986-02-15T23:59:59.000Z

433

Oxygen Release and Exchange in Niobium Oxide MEHPPV Hybrid Solar Cells  

Science Journals Connector (OSTI)

Oxygen Release and Exchange in Niobium Oxide MEHPPV Hybrid Solar Cells ... This deliberate choice was made in order to distinguish the function of the transparent conducting oxide (TCO) and metal electrode as compared to traditional polymer photovoltaics where the TCO is the hole collector and the metal is the electron collector. ... The horizontal dashed black line in the graph (E) corresponds to the theoretical ratio (0.2%) for atmospheric oxygen. ...

Monica Lira-Cantu; Kion Norrman; Jens W. Andreasen; Frederik C. Krebs

2006-10-25T23:59:59.000Z

434

Site-Specific Imaging of Elemental Steps in Dehydration of Diols on TiO2(110)  

SciTech Connect

The conversion of diols on partially reduced TiO2(110) at low coverage was studied using variable-temperature scanning tunneling microscopy, temperature programmed desorption and density functional theory calculations. We find, that below ~230 K, ethane-1,2-diol and propane-1,3-diol molecules adsorb predominantly on five-fold coordinated Ti5c atoms. The dynamic equilibrium between molecularly bound and dissociated species resulting from O-H bond scission and reformation is observed. As the diols start to diffuse on the Ti5c rows above ~230 K, they dissociate irreversibly upon encountering bridging oxygen (Ob) vacancy (VOs) defects. Two dissociation pathways, one via O-H and the other via C-O bond scission leading to identical surface intermediates, hydroxyalkoxy, Ob-(CH2)n-OH (n = 2, 3) and bridging hydroxyl, HOb, are seen. For O-H bond scission, the Ob-(CH2)n-OH is found on the position of the original VO, while for C-O scission it is found on the adjacent Ob site. Theoretical calculations suggest that the observed mixture of C-O/O-H bond breaking processes are a result of the steric factors enforced upon the diols by the second OH group that is bound to a Ti5c site. At room temperature, rich dissociation/reformation dynamics of the second, Ti5c-bound O-H leads to the formation of dioxo, Ob-(CH2)n-OTi, species. Above ~400 K, both Ob-(CH2)n-OH and Ob-(CH2)n-OTi species convert into a new intermediate, that is centered on Ob row. Combined experimental and theoretical evidence shows that this intermediate is most likely a new dioxo, Ob-(CH2)2-Ob, species. Further annealing leads to sequential C-Ob bond cleavage and alkene desorption above ~ 500 K. Simulations find that the sequential C-O bond breaking process follows a homolytic diradical pathway with the first C-O bond breaking event accompanied by a non-adiabatic electron transfer within the TiO2(110) substrate.

Acharya, Danda P.; Yoon, Yeohoon; Li, Zhenjun; Zhang, Zhenrong; Lin, Xiao; Mu, Rentao; Chen, Long; Kay, Bruce D.; Rousseau, Roger J.; Dohnalek, Zdenek

2013-11-26T23:59:59.000Z

435

Economic Analysis for Conceptual Design of Supercritical O2-Based PC Boiler  

SciTech Connect

This report determines the capital and operating costs of two different oxygen-based, pulverized coal-fired (PC) power plants and compares their economics to that of a comparable, air-based PC plant. Rather than combust their coal with air, the oxygen-based plants use oxygen to facilitate capture/removal of the plant CO{sub 2} for transport by pipeline to a sequestering site. To provide a consistent comparison of technologies, all three plants analyzed herein operate with the same coal (Illinois No 6), the same site conditions, and the same supercritical pressure steam turbine (459 MWe). In the first oxygen-based plant, the pulverized coal-fired boiler operates with oxygen supplied by a conventional, cryogenic air separation unit, whereas, in the second oxygen-based plant, the oxygen is supplied by an oxygen ion transport membrane. In both oxygen-based plants a portion of the boiler exhaust gas, which is primarily CO{sub 2}, is recirculated back to the boiler to control the combustion temperature, and the balance of the flue gas undergoes drying and compression to pipeline pressure; for consistency, both plants operate with similar combustion temperatures and utilize the same CO{sub 2} processing technologies. The capital and operating costs of the pulverized coal-fired boilers required by the three different plants were estimated by Foster Wheeler and the balance of plant costs were budget priced using published data together with vendor supplied quotations. The cost of electricity produced by each of the plants was determined and oxygen-based plant CO{sub 2} mitigation costs were calculated and compared to each other as well as to values published for some alternative CO{sub 2} capture technologies.

Andrew Seltzer; Archie Robertson

2006-09-01T23:59:59.000Z

436

CO2?laser?induced deflagration of fuel/oxygen mixtures  

Science Journals Connector (OSTI)

Weakly focused pulsed?CO2?laser radiation has been examined as an ignition source for low?pressure (85100 Torr) near?stoichiometric fuel/oxygen mixtures containing the following fuels: ethylene methyl fluoride methanol ethanol dimethyl ether p?dioxane n?propyl nitrate and iso?propyl nitrate. The data analysis includes characterization of the spatially dependent ir absorption in the test cell calculation of appropriate medium temperatures from the absorbed laser energy and correlation of observed ignition delay times t ig with the calculated temperatures. Effects of hydrodynamic motion on the pressure density and temperature profiles of the irradiated samples were modeled using a computer code for two?dimensional wave propagation. Code predictions are in accordance with experimental pressure?time histories obtained using a piezoelectric transducer. Minimum ignition temperatures ranged from 590 K for the iso?propyl nitrate/O2 system to 1645 K for CH3F/O2. The observed functional relationship between t ig and temperature T was generally of the form ln?t ig =A/T+B where A and B are constants. This relationship follows the form predicted by thermal and degenerate chain ignition theories viz. ln?t ig =E act/ R T+constant where E act corresponds to an overall activation energy. Using this relation derived activation energies are 86 57 42 47 ?40 13 and 12 kcal/mole for the CH3F/O2 CH3OCH3/O2 CH3OH/O2 C2H5OH/O2 C4H8O2/O2 n?propyl nitrate/O2 and iso?propyl nitrate/O2 mixtures respectively. These results are in reasonable agreement with available data from shock?tube and hot air stream injection techniques. In contrast an anomalous threshold?like effect was observed for laser ignition of C2H4/O2. The applicability of ignition schemes of this type to time?resolved kinetic spectroscopic studies is briefly discussed.

Wayne M. Trott

1983-01-01T23:59:59.000Z

437

AtmosphericAtmospheric Composition Introduction The division investigates the atmospheric  

E-Print Network (OSTI)

development on observation side was the installation of an ozone observation station in Surinam in close co-operation with the Surinam Meteorological Service. Processes in the tropical regions are important for the global climate and the global atmospheric composition. The participation in Indoex (Indian Ocean Experiment) and this Surinam

Haak, Hein

438

The future of the carbon cycle: review, calcification response, ballast and feedback on atmospheric CO2  

Science Journals Connector (OSTI)

...inorganic carbon ( C O2) in seawater is in the form HCO- 3 , the...inorganic carbon species in seawater is such that, for a given...effective buffering capacity of seawater is analogous to the Revelle...larger capacity for carbon storage in the oceans than in the atmosphere...

2003-01-01T23:59:59.000Z

439

Comparative investigation on chemical looping combustion of coal-derived synthesis gas containing H2S over supported NiO oxygen carriers  

SciTech Connect

Chemical looping combustion (CLC) of simulated coal-derived synthesis gas was conducted with NiO oxygen carriers supported on SiO2, ZrO2, TiO2, and sepiolite. The effect of H2S on the performance of these samples for the CLC process was also evaluated. Five-cycle thermogravimetric analysis (TGA) tests at 800 #1;C indicated that all oxygen carriers had a stable performance at 800 #1;C, except NiO/SiO2. Full reduction/oxidation reactions of the oxygen carrier were obtained during the five-cycle test. It was found that support had a significant effect on reaction performance of NiO both in reduction and oxidation rates. The reduction reaction was significantly faster than the oxidation reaction for all oxygen carriers, while the oxidation reaction is fairly slow due to oxygen diffusion on NiO layers. The reaction profile was greatly affected by the presence of H2S, but there was no effect on the capacity due to the presence of H2S in synthesis gas. The presence of H2S decreased reduction reaction rates significantly, but oxidation rates of reduced samples increased. X-ray diffraction (XRD) data of the oxidized samples after a five-cycle test showed stable crystalline phases without any formation of sulfides or sulfites/sulfates. Increase in reaction temperature to 900 #1;C had a positive effect on the performance.

Ksepko, E.; Siriwardane, R.; Tian, H.; Simonyi, T.; Sciazko, M.

2010-01-01T23:59:59.000Z

440

Si(001) vicinal surface oxidation in O2: Angle-resolved Si 2p core-level study using synchroton radiation  

Science Journals Connector (OSTI)

The aim of this work is to determine if, after oxidation in pure O2, a vicinal surface Si(001) miscut 5 towards the [110] direction, exhibits a preferential SiO2 formation on the [110] ledges. In a first stage, combining XPS (X-ray photoelectron spectroscopy) and LEED (low-energy electron diffraction) available in an auxiliary chamber, we examine the cleaning conditions leading to a non-faceted stepped Si surface with dominant (2 1) single domains. This surface preparation is reproduced in the synchroton facility chamber where ARPR-single-resolved photoemission spectroscopy) is performed: after cleaning the Si surface and studying the starting situation (san- states, initial contamination), an ultra-thin oxide film (? 1.5 1015 oxidised Si atoms/cm2) is grown at 785800C, under Torr of oxygen. The absence of anisotropy in the ARPES emission of the Si 2p core levels taken at the minimum electron escape depth (hv=130eV), points to no extra-growth of the oxide on the ledges. The in-depth distribution of the oxide states seems to be homogeneous, within the sensitivity of the probe. On the other hand, after partial thermal desorption of the ultra-thin oxide film in vacuum, a strong anisotropy in the emission of electrons from SiO2 is seen in areas where oxide patches coexist with bare silicon. It is shown that this ensues from a significant step bunching and (111) faceting of the surface. A correlation is made with SEM (scanning electron microscopy) images of the surface. The problem of step bunching, inasmuch as it can alter the interpretation of shadowing effects, is emphasized.

F. Rochet; H. Roulet; G. Dufour; S. Carniato; C. Guillot; N. Barrett; M. Froment

1992-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "atmospheric oxygen o2" 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

Effects of Reduction Temperature and Metal-Support Interactions on the Catalytic Activity of Pt/g-Al2O3 and Pt/TiO2 for the Oxidation of CO in the Presence and Absence of H2.  

SciTech Connect

TiO2- and -Al2O3-supported Pt catalysts were characterized by HRTEM, XPS, EXAFS, and in situ FTIR spectroscopy after activation at various conditions, and their catalytic properties were examined for the oxidation of CO in the absence and presence of H2 (PROX). When {gamma}-Al{sub 2}O{sub 3} was used as the support, the catalytic, electronic, and structural properties of the Pt particles formed were not affected substantially by the pretreatment conditions. In contrast, the surface properties and catalytic activity of Pt/TiO2 were strongly influenced by the pretreatment conditions. In this case, an increase in the reduction temperature led to higher electron density on Pt, altering its chemisorptive properties, weakening the Pt-CO bonds, and increasing its activity for the oxidation of CO. The in situ FTIR data suggest that both the terminal and bridging CO species adsorbed on fully reduced Pt are active for this reaction. The high activity of Pt/TiO2 for the oxidation of CO can also be attributed to the ability of TiO2 to provide or stabilize highly reactive oxygen species at the metal-support interface. However, such species appear to be more reactive toward H{sub 2} than CO. Consequently, Pt/TiO{sub 2} shows substantially lower selectivities toward CO oxidation under PROX conditions than Pt/{gamma}-Al{sub 2}O{sub 3}.

Alexeev,O.; Chin, S.; Engelhard, M.; Ortiz-Soto, L.; Amiridis, M.

2005-01-01T23:59:59.000Z

442

Atmospheric Radiation Measurement Program  

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

3 3 ARM 2003 Tom Ackerman Chief Scientist Tom Ackerman Chief Scientist ARM ARM Atmospheric Radiation Measurement Atmospheric Radiation Measurement WARNING! WARNING! Today is April 1 But that has NO bearing on this message Today is April 1 But that has NO bearing on this message ARM ARM Atmospheric Radiation Measurement Atmospheric Radiation Measurement Two Topics Two Topics * Status of ARM (quick overview) * Science plan - ARM in the next 5 years * Status of ARM (quick overview) * Science plan - ARM in the next 5 years ARM ARM Atmospheric Radiation Measurement Atmospheric Radiation Measurement ARM Status - Science ARM Status - Science * Steadily increasing productivity - Poster session - over 220 posters (may need to do something about submissions next year) - Peer-reviewed articles: 2.5 to 3 per year per

443

MTBE, Oxygenates, and Motor Gasoline  

Gasoline and Diesel Fuel Update (EIA)

MTBE, Oxygenates, and MTBE, Oxygenates, and Motor Gasoline Contents * Introduction * Federal gasoline product quality regulations * What are oxygenates? * Who gets gasoline with oxygenates? * Which areas get MTBE? * How much has been invested in MTBE production capacity? * What does new Ethanol capacity cost? * What would an MTBE ban cost? * On-line information resources * Endnotes * Summary of revisions to this analysis Introduction The blending of methyl tertiary butyl ether (MTBE) into motor gasoline has increased dramatically since it was first produced 20 years ago. MTBE usage grew in the early 1980's in response to octane demand resulting initially from the phaseout of lead from gasoline and later from rising demand for premium gasoline. The oxygenated gasoline program stimulated an

444

Oxygen detection using evanescent fields  

DOE Patents (OSTI)

An apparatus and method for the detection of oxygen using optical fiber based evanescent light absorption. Methylene blue was immobilized using a sol-gel process on a portion of the exterior surface of an optical fiber for which the cladding has been removed, thereby forming an optical oxygen sensor. When light is directed through the optical fiber, transmitted light intensity varies as a result of changes in the absorption of evanescent light by the methylene blue in response to the oxygen concentration to which the sensor is exposed. The sensor was found to have a linear response to oxygen concentration on a semi-logarithmic scale within the oxygen concentration range between 0.6% and 20.9%, a response time and a recovery time of about 3 s, ant to exhibit good reversibility and repeatability. An increase in temperature from 21.degree. C. to 35.degree. C. does not affect the net absorption of the sensor.

Duan, Yixiang (Los Alamos, NM); Cao, Weenqing (Los Alamos, NM)

2007-08-28T23:59:59.000Z

445

In-situ imaging of the nucleation and growth of epitaxial anatase TiO2(001) films on SrTiO3(001)  

SciTech Connect

The growth of TiO2 anatase films on Nb doped SrTiO3(001) by oxygen-assisted molecular beam epitaxy has been studied in-situ by scanning tunneling microscopy. We show that the initial growth follows the Stranski-Krastanov mode, where islands form on top of a wetting layer consisting of two monolayers (ML) of TiO2. The epitaxial islands subsequently nucleate and coalescence into large commonly-oriented crystallites. The (4x4) reconstruction observed by reflection high-energy electron diffraction (RHEED) is shown to result from the coexistence of individual (4x1) and (1x4) reconstructions present on different crystallite surfaces. The anatase grows in units of bilayers, resulting in a step height of 2 ML (~0.5 nm). This result explains the fact that the measured period of the RHEED specular-beam intensity oscillations corresponds to the time required for deposition of 2 ML. Ar ion sputtering and UHV annealing results in a transformation to coexisting (4x1) and (1x4) reconstructed terraces on individual crystallites, as commonly observed by ex-situ STM studies.

Du, Yingge; Kim, Dong Jun; Kaspar, Tiffany C.; Chamberlin, Sara E.; Lyubinetsky, Igor; Chambers, Scott A.

2012-09-30T23:59:59.000Z

446

Probing Defect Sites on TiO_2 with H_3 Re_3 (CO)_12 : Spectroscopic Characterization of the Surface Species  

SciTech Connect

Samples of the anatase phase of titania were treated under vacuum to create Ti3+ surface-defect sites and surface O- and O2- species (indicated by electron paramagnetic resonance (EPR) spectra), accompanied by the disappearance of bridging surface OH groups and the formation of terminal Ti3+OH groups (indicated by IR spectra). EPR spectra showed that the probe molecule [Re3(CO)12H3] reacted preferentially with the Ti3+ sites, forming Ti4+ sites with OH groups as the [Re3(CO)12H3] was adsorbed. Extended X-ray absorption fine structure (EXAFS) spectra showed that these clusters were deprotonated upon adsorption, with the triangular metal frame remaining intact; EPR spectra demonstrated the simultaneous removal of surface O- and O2- species. The data determined by the three complementary techniques form the basis of a schematic representation of the surface chemistry. According to this picture, during evacuation at 773 K, defect sites are formed on hydroxylated titania as a bridging OH group is removed, forming two neighboring Ti3+ sites, or, when a Ti4+O bond is cleaved, forming a Ti3+ site and an O- species, with the Ti4+OH group being converted into a Ti3+OH group. When the probe molecule [Re3(CO)12H3] is adsorbed on a titania surface with Ti3+ defect sites, it reacts preferentially with these sites, becoming deprotonated, removing most of the oxygen radicals, and healing the defect sites.

Suriye,K.; Lobo-Lapidus, R.; Yeagle, G.; Praserthdam, P.; Britt, R.; Gates, B.

2008-01-01T23:59:59.000Z

447

Formation of CO precursors during char gasification with O2, CO2 and H2O  

E-Print Network (OSTI)

Formation of CO precursors during char gasification with O2, CO2 and H2O Alejandro Montoya a are presented to get insight into an unified mechanism of uncatalyzed carbon gasification. D 2002 Elsevier Science B.V. All rights reserved. Keywords: Gasification; Chemisorption; Molecular simulation; Surface

Truong, Thanh N.

448

Ti-Peroxo Species in the TS-1/H2O2/H2O System  

Science Journals Connector (OSTI)

This work is devoted to the study of the active species present on the TS-1-H2O2/H2O catalytic system and to the elucidation of the mechanisms of formation and interconversion of these species. In particular new experimental data and computational ...

Francesca Bonino; Alessandro Damin; Gabriele Ricchiardi; Marco Ricci; Guido Span; Rino D'Aloisio; Adriano Zecchina; Carlo Lamberti; Carmelo Prestipino; Silvia Bordiga

2004-02-18T23:59:59.000Z

449

Inorganic-modified semiconductor TiO2 nanotube arrays for photocatalysis  

E-Print Network (OSTI)

or photoelectrochemical degradation of organic pollutants, the splitting of water into H2, and solar cells holds promise for meeting the global challenge of supplying clean energy. In this context, semiconductor TiO2 stands out and depletion of fossil fuel resources have emerged as two major obstacles for the sustainable development

Lin, Zhiqun

450

Solar Energy Materials & Solar Cells 71 (2002) 261271 Photoelectric behavior of nanocrystalline TiO2  

E-Print Network (OSTI)

Solar Energy Materials & Solar Cells 71 (2002) 261­271 Photoelectric behavior of nanocrystalline Ti 100101, People's Republic of China e Synchrotron Radiation Laboratory at Institute of High Energy Physics. A sandwich-type solar cell fabricated by this dye-sensitized nanocrystalline TiO2 film generated 6:1 mA cm?2

Huang, Yanyi

451

Optical Properties of ZrO2Containing Anodic Coatings on Aluminum  

Science Journals Connector (OSTI)

Anodic oxide coatings (AOC) formed at the potentials of spark breakdowns...2ZrF6) contain up to 36 wt.% of Zr. The modification of ZrO2 in AOC is tetragonal. The reflection coefficients of AOC have been measured ...

P. M. Nedozorov; K. N. Kilin; T. P. Yarovaya

2001-07-01T23:59:59.000Z

452

Ambient pressure thermal desorption spectroscopy (AP-TDS) of NiO/SiO2 catalysts  

Science Journals Connector (OSTI)

The Sabatier reaction is a key process in the power-to-gas application which is considered to contribute to...2 (NiO/SiO2) which is commonly used in the Sabatier reaction. A novel technique for the characteriza...

M. Stdter; K. Mller; F. Rachow; M. Richter; D. Schmeier

2013-12-01T23:59:59.000Z

453

Formation and characterization of TiO2/CNT nanomaterials dried under supergravity conditions  

Science Journals Connector (OSTI)

The elaboration of bilayer TiO2/CNT films dried under terrestrial gravity conditions (g) and on a centrifuge with 1.3g and 7g is reported. The changes in microstructure and thickness of these coatings under supergravity environment ...

Minerva Vargas; Marina E. Rincn; Eduardo Ramos

2009-01-01T23:59:59.000Z

454

The evolution of respiratory O2/NO reductases: an out-of-the-phylogenetic-box perspective  

Science Journals Connector (OSTI)

...Through the solubility coefficient...The crucial gas sensor proteins...then of the nitrogen oxides...standing water body due...the case of gases) substrates...either O2 or nitrogen oxyanions...dissolved in water. Incidentally...Terrestrial nitrogen and noble gases in lunar...

2014-01-01T23:59:59.000Z

455

The Stability of Organic Solvents and Carbon Electrode in Nonaqueous Li-O2 Batteries  

SciTech Connect

The effect of different kinds of aprotic organic solvents on the discharge performance and discharge products in Li-O2 batteries was systematically investigated. The discharge products deposited in air cathodes were analyzed by X-ray diffraction, in situ gas chromatography/mass spectroscopy and X-ray photoelectron spectroscopy. We found that a significant amount of Li2O2 can be formed in glyme-based electrolytes during the discharge process, while only small amount of Li2O2 is produced in electrolytes of phosphate, nitrile, ionic liquid and sulfoxide. However, in all the seven types of solvent systems we studied, Li2CO3 and LiF were still formed as byproducts whose compositions are strongly related to the solvents. Li2CO3 is produced not from the carbon air electrode but from oxidation and decomposition of the solvent as we verified by using a 13C-labeled carbon electrode and the solid-state 13C-MAS NMR technique. The formation of Li2CO3 and LiF during discharge will greatly reduce the Coulombic efficiency and cycle life of the Li-air batteries. Therefore, better electrolytes that can ensure the formation of Li2O2 but minimize other reaction products formed on air electrodes of Li-air batteries need to be further investigated.

Xu, Wu; Hu, Jian Z.; Engelhard, Mark H.; Towne, Silas A.; Hardy, John S.; Xiao, Jie; Feng, Ju; Hu, Mary Y.; Zhang, Jian; Ding, Fei; Gross, Mark E.; Zhang, Jiguang

2012-05-18T23:59:59.000Z

456

On really stoichiometric LiCoO2 M. Mntrier1  

E-Print Network (OSTI)

recalled above (with LS Co4+ ions). We had also concluded some time ago that excess Li in lithium cobalt long thermal treatment for complete elimination of excess Li. Such highly stoichiometric Li1CoO2 criterion for the characterization of Li-stoichiometry in lithium cobalt oxide. Hertz et al (7) also state

Paris-Sud XI, Université de

457

Short communication Effect of vanadium redox species on photoelectrochemical behavior of TiO2  

E-Print Network (OSTI)

. Alternative and sustainable energy sources such as solar, wind, tidal power, geothermal, hydroelectricity implementation is hydrogen handling. Although molecular hydrogen has very high energy density on a mass basis and TiO2/WO3 photo-electrodes Dong Liu a , Fuqiang Liu a,*, Jianguo Liu b a Electrochemical Energy Lab

Liu, Fuqiang

458

SiO2 Nanoparticle Sequestration via Reactive Functionalization in Holographic Polymer-Dispersed  

E-Print Network (OSTI)

SiO2 Nanoparticle Sequestration via Reactive Functionalization in Holographic Polymer addition of nanoparticles. Nanoparticles of many materials can be synthesized in sizes small enough are available to control the chemical interaction of the nanoparticles with the HPDLC system. Previous research

Braun, Paul

459

The influence of surface conductivity on the apparent zeta potential of TiO2 nanoparticles  

E-Print Network (OSTI)

Titanium dioxide is widely used as TiO2 nanoparticles and has a large variety of potential applications in of these properties, the surface ionization of titanium dioxide nanoparticles in contact with an electrolytic solution is a physico-chemical parameter of particular importance to describe ion adsorption and electrostatic

Paris-Sud XI, Université de

460

Photocatalytic Degradation of VOC's by TOTO's Hydrotect (TiO2 Impregnated) Surfaces  

E-Print Network (OSTI)

, naturally occurs in wood and volcanic gases. Decaying organic matter can also produce methanol. Paint. This report describes the photocatalytic degradation of formaldehyde and methanol, two common VOC's, by TiO2 and methanol tests (Land et al., 2008). A standardized aqueous solution of formaldehyde and methanol was used

Bergin, Mike

Note: This page contains sample records for the topic "atmospheric oxygen o2" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Absorption Spectra Related to Heterogeneous Electron Transfer Reactions: The Perylene TiO2 System  

E-Print Network (OSTI)

Absorption Spectra Related to Heterogeneous Electron Transfer Reactions: The Perylene TiO2 System Form: March 16, 2005 Linear absorption spectra of dye-semiconductor systems (perylene attached displaying line broadenings follow the qualitative trend obtained from transient absorption spectra. I

Röder, Beate

462

SELECTIVE FILTER FOR SnO2 BASED GAS SENSOR : APPLICATION TO HYDROGEN TRACE DETECTION  

E-Print Network (OSTI)

are requested in several fields such as applications [1], fuel cell [2], radioactive waste storage and diverse selectivity of a sensor includes the addition of a catalyst to the tin oxide powder. In the case of hydrogen1 SELECTIVE FILTER FOR SnO2 BASED GAS SENSOR : APPLICATION TO HYDROGEN TRACE DETECTION G

Paris-Sud XI, Université de

463

Acid-Based Synthesis of Monodisperse Rare-Earth-Doped Colloidal SiO2 Spheres  

E-Print Network (OSTI)

display narrow-line intra-4f transi- tions that are first order independent of the local environment method to dope SiO2 particles with RE ions via an acid-based wet chemical synthesis route by adding of the particles are studied using scanning electron microscopy (SEM), transmission electron microscopy (TEM

Polman, Albert

464

Hybrid Carbon Nanotubes-TiO2 Photoanodes for High Efficiency Dye-Sensitized Solar Cells  

E-Print Network (OSTI)

Hybrid Carbon Nanotubes-TiO2 Photoanodes for High Efficiency Dye-Sensitized Solar Cells Kadiatou-Boulet, Varennes, Quebec J3X 1S2, Canada Department of Chemical Sciences and Technology & NAST Center, University, 25133 Brescia, Italy Solar Cells Laboratory, Institute of Materials Science and Technology (IMRE

465

Oxygen Transport Ceramic Membranes  

SciTech Connect

The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and initial studies on newer composition of Ti doped LSF. Dense OTM bars provided by Praxair were loaded to fracture at varying stress rates. Studies were done at room temperature in air and at 1000 C in a specified environment to evaluate slow crack growth behavior. In addition, studies were also begun to obtain reliable estimates of fracture toughness and stable crack growth in specific environments. Newer composition of Ti doped LSF membranes were characterized by neutron diffraction analysis. Quench studies indicated an apparent correlation between the unit cell volume and oxygen occupancy. The studies however, indicated an anomaly of increasing Fe/Ti ratio with change in heat treatment. Ti doped LSF was also characterized for stoichiometry as a function of temp and pO{sub 2}. The non stoichiometry parameter {delta} was observed to increase almost linearly on lowering pO{sub 2} until a ideal stoichiometric composition of {delta} = 0.175 was approached.

S. Bandopadhyay; N. Nagabhushana; X.-D Zhou; W.B. Yelon; H.U. Anderson; Alan Jacobson; C.A. Mims

2004-02-01T23:59:59.000Z

466

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect

Conversion of natural gas to liquid fuels and chemicals is a major goal for the Nation as it enters the 21st Century. Technically robust and economically viable processes are needed to capture the value of the vast reserves of natural gas on Alaska's North Slope, and wean the Nation from dependence on foreign petroleum sources. Technologies that are emerging to fulfill this need are all based syngas as an intermediate. Syngas (a mixture of hydrogen and carbon monoxide) is a fundamental building block from which chemicals and fuels can be derived. Lower cost syngas translates directly into more cost-competitive fuels and chemicals. The currently practiced commercial technology for making syngas is either steam methane reforming (SMR) or a two-step process involving cryogenic oxygen separation followed by natural gas partial oxidation (POX). These high-energy, capital-intensive processes do not always produce syngas at a cost that makes its derivatives competitive with current petroleum-based fuels and chemicals.

Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

2002-01-01T23:59:59.000Z

467

Atmospheric Neutrino Fluxes  

E-Print Network (OSTI)

Starting with an historical review, I summarize the status of calculations of the flux of atmospheric neutrinos and how they compare to measurements.

Thomas K. Gaisser

2005-02-18T23:59:59.000Z

468

ARM - Atmospheric Heat Budget  

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

ListAtmospheric Heat Budget Outreach Home Room News Publications Traditional Knowledge Kiosks Barrow, Alaska Tropical Western Pacific Site Tours Contacts Students Study Hall About...

469

Low Oxygen Environments in Chesapeake Bay  

E-Print Network (OSTI)

Low Oxygen Environments in Chesapeake Bay Jeremy Testa Chesapeake Biological Laboratory University of Maryland Center for Environmental Science Why we care about low oxygen? What causes low oxygen? Where and When does Chesapeake Bay lose oxygen? #12;#12;Hypoxia and Chesapeake Animals Low dissolved oxygen

Boynton, Walter R.

470

Charge transfer of 0.5-, 1.5-, and 5-keV protons with atomic oxygen: Absolute differential and integral cross sections  

Science Journals Connector (OSTI)

We report measurements of the absolute differential cross sections for charge-transfer scattering of 0.5-, 1.5-, and 5-keV protons by atomic oxygen at scattering angles between 0.01 and 2.6 in the laboratory frame. Absolute integral cross sections are also reported and compared with previously published total cross sections. The measurements were made using a flowing gas target, which consisted of a mixture of atomic and molecular oxygen produced by passage of O2 through a microwave discharge. The cross sections for atomic oxygen were obtained by appropriate subtraction of the signal due to molecular oxygen from that due to the mixture of O and O2. 1996 The American Physical Society.

B. G. Lindsay; D. R. Sieglaff; D. A. Schafer; C. L. Hakes; K. A. Smith; R. F. Stebbings

1996-01-01T23:59:59.000Z

471

TiOx Films Deposited by Plasma Enhanced Chemical Vapour Deposition Method in Atmospheric Dielectric Barrier Discharge Plasma  

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The plasma enhanced chemical vapour deposition method applying atmospheric dielectric barrier discharge (ADBD) plasma was used for TiOx thin films deposition employing titanium (IV) isopropoxide and oxygen as rea...

Y. Klenko; J. Pichal

2012-12-01T23:59:59.000Z

472

Generation of Teflon-like layers on cellophane surfaces under atmospheric pressure non-equilibrium SF6-plasma environments  

Science Journals Connector (OSTI)

In this contribution a novel atmospheric pressure SF6coldplasma method is suggested for the conversion of... x , (x< 6 ) species generated in the discharge for oxygen extractio...

L. E. Cruz-Barba; S. Manolache; F. Denes

2003-07-01T23:59:59.000Z

473

Electrochemical oxygen pumps. Final CRADA report.  

SciTech Connect

All tasks of the Work Plan of ISTC Project 2277p have been completed, thus: (1) techniques of chemical synthesis were developed for more than ten recipes of electrolyte based on cerium oxide doped with 20 mole% of gadolinium (CeGd)O{sub 2}, doped by more than 10 oxide systems including 6 recipes in addition to the Work Plan; (2) electric conductivity and mechanical strength of CeGd specimens with additions of oxide systems were performed, two candidate materials for the electrolyte of electrochemical oxygen pump (pure CeGd and CeGd doped by 0.2 wt% of a transition metal) were chosen; (3) extended studies of mechanical strength of candidate material specimens were performed at room temperature and at 400, 600, 800 C; (4) fixtures for determination of mechanical strength of tubes by external pressure above 40 atmospheres at temperature up to 700 C were developed and fabricated; and (5) technology of slip casting of tubes from pure (Ce,Gd)O{sub 2} and of (Ce,Gd)O{sub 2} doped by 0.2 wt% of a transition metal, withstanding external pressure of minimum 40 atmospheres at temperature up to 700 C was developed, a batch of tubes was sent for testing to Argonne National Laboratory; (6) technology of making nanopowder from pure (Ce,Gd)O{sub 2} was developed based on chemical synthesis and laser ablation techniques, a batch of nanopowder with the weight 1 kg was sent for testing to Argonne National Laboratory; (7) a business plan for establishing a company for making powders of materials for electrochemical oxygen pump was developed; and (8) major results obtained within the Project were reported at international conferences and published in the Russian journal Electrochemistry. In accordance with the Work Plan a business trip of the following project participants was scheduled for April 22-29, 2006, to Tonawanda, NY, USA: Manager Victor Borisov; Leader of technology development Gennady Studenikin; Leader of business planning Elena Zadorozhnaya; Leader of production Vasily Lepalovsky; and Translator Vladimir Litvinov. During this trip project participants were to discuss with the project Technical Monitor J.D. Carter and representative of Praxair Inc. J. Chen the results of project activities (prospects of transition metal-doped material application in oxygen pumps), as well as the prospects of cooperation with Praxair at the meeting with the company management in the following fields: (1) Deposition of thin films of oxide materials of complex composition on support by magnetron and ion sputtering, research of coatings properties; (2) Development of block-type structure technology (made of porous and dense ceramics) for oxygen pump. The block-type structure is promising because when the size of electrolyte block is 2 x 2 inches and assembly height is 10 inches (5 blocks connected together) the area of active surface is ca. 290 square inches (in case of 8 slots), that roughly corresponds to one tube with diameter 1 inch and height 100 inches. So performance of the system made of such blocks may be by a factor of two or three higher than that of tube-based system. However one month before the visit, J. Chen notified us of internal changes at Praxair and the cancellation of the visit to Tonawanda, NY. During consultations with the project Technical Monitor J.D. Carter and Senior Project Manager A. Taylor a decision was made to extend the project term by 2 quarters to prepare proposals for follow-on activities during this extension (development of block-type structures made of dense and porous oxide ceramics for electrochemical oxygen pumps) using the funds that were not used for the trip to the US.

Carter, J. D.

2009-10-01T23:59:59.000Z

474

Interaction of oxygen with sodium at 80 and 20 K  

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We have studied the interaction of oxygen with evaporated Na films at 80 and 20 K, by means of core-level and valence photoemission spectroscopy and photoexcited Auger spectroscopy, as well as plasmon loss structures associated with core-level emission. The initial oxidation at 80 and 20 K is characterized by an oxygen 2p resonance at about -3.4 eV with respect to the Fermi level, increasing intensity in the Na-O interatomic Auger transition, increasing width and intensity of the Na 2p core level, and changes in the surface-plasmon loss region which might be interpreted as a decreasing free-electron density. Further oxidation leads to <